Programs & Examples On #Isr

Uncaught Invariant Violation: Too many re-renders. React limits the number of renders to prevent an infinite loop

I also have the same problem, and the solution is I didn't bind the event in my onClick. so when it renders for the first time and the data is more, which ends up calling the state setter again, which triggers React to call your function again and so on.

export default function Component(props) {

function clickEvent (event, variable){
    console.log(variable);
}

return (
    <div>
        <IconButton
            key="close"
            aria-label="Close"
            color="inherit"
            onClick={e => clickEvent(e, 10)} // or you can call like this:onClick={() => clickEvent(10)} 
        >
    </div>
)
}

Failed to auto-configure a DataSource: 'spring.datasource.url' is not specified

Go to resources folder where the application.properties is present, update the below code in that.

spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration

phpmyadmin - count(): Parameter must be an array or an object that implements Countable

Replace Function:

function PMA_isRememberSortingOrder($analyzed_sql_results) {
return $GLOBALS['cfg']['RememberSorting']
    &&!(
        $analyzed_sql_results['is_count']
        || $analyzed_sql_results['is_export']
        || $analyzed_sql_results['is_func']
        || $analyzed_sql_results['is_analyse']
    )&&
    $analyzed_sql_results['select_from']&&
    (
        empty($analyzed_sql_results['select_expr'])||
        count($analyzed_sql_results['select_expr'])==1&&
        $analyzed_sql_results['select_expr'][0] == '*'
    )
    && count($analyzed_sql_results['select_tables']) == 1;
}

When I run `npm install`, it returns with `ERR! code EINTEGRITY` (npm 5.3.0)

I am behind my organization's proxy, running the following commands fixed the issue for me

npm config set proxy http://proxy.yourproxydomain.com:port
npm config set https-proxy http://proxy.yourproxydomain.com:port
npm config set strict-ssl false
npm config set registry https://registry.npmjs.org/

React-router v4 this.props.history.push(...) not working

Don't use with Router.

handleSubmit(e){
   e.preventDefault();
   this.props.form.validateFieldsAndScroll((err,values)=>{
      if(!err){
        this.setState({
            visible:false
        });
        this.props.form.resetFields();
        console.log(values.username);
        const path = '/list/';
        this.props.history.push(path);
      }
   })
}

It works well.

onKeyDown event not working on divs in React

You're missing the binding of the method in the constructor. This is how React suggests that you do it:

class Whatever {
  constructor() {
    super();
    this.onKeyPressed = this.onKeyPressed.bind(this);
  }

  onKeyPressed(e) {
    // your code ...
  }

  render() {
    return (<div onKeyDown={this.onKeyPressed} />);
  }
}

There are other ways of doing this, but this will be the most efficient at runtime.

How to implement authenticated routes in React Router 4?

I was also looking for some answer. Here all answers are quite good, but none of them give answers how we can use it if user starts application after opening it back. (I meant to say using cookie together).

No need to create even different privateRoute Component. Below is my code

    import React, { Component }  from 'react';
    import { Route, Switch, BrowserRouter, Redirect } from 'react-router-dom';
    import { Provider } from 'react-redux';
    import store from './stores';
    import requireAuth from './components/authentication/authComponent'
    import SearchComponent from './components/search/searchComponent'
    import LoginComponent from './components/login/loginComponent'
    import ExampleContainer from './containers/ExampleContainer'
    class App extends Component {
    state = {
     auth: true
    }


   componentDidMount() {
     if ( ! Cookies.get('auth')) {
       this.setState({auth:false });
     }
    }
    render() {
     return (
      <Provider store={store}>
       <BrowserRouter>
        <Switch>
         <Route exact path="/searchComponent" component={requireAuth(SearchComponent)} />
         <Route exact path="/login" component={LoginComponent} />
         <Route exact path="/" component={requireAuth(ExampleContainer)} />
         {!this.state.auth &&  <Redirect push to="/login"/> }
        </Switch>
       </BrowserRouter>
      </Provider>);
      }
     }
    }
    export default App;

And here is authComponent

import React  from 'react';
import { withRouter } from 'react-router';
import * as Cookie from "js-cookie";
export default function requireAuth(Component) {
class AuthenticatedComponent extends React.Component {
 constructor(props) {
  super(props);
  this.state = {
   auth: Cookie.get('auth')
  }
 }
 componentDidMount() {
  this.checkAuth();
 }
 checkAuth() {
  const location = this.props.location;
  const redirect = location.pathname + location.search;
  if ( ! Cookie.get('auth')) {
   this.props.history.push(`/login?redirect=${redirect}`);
  }
 }
render() {
  return Cookie.get('auth')
   ? <Component { ...this.props } />
   : null;
  }
 }
 return  withRouter(AuthenticatedComponent)
}

Below I have written blog, you can get more depth explanation there as well.

Create Protected routes in ReactJS

VueJS conditionally add an attribute for an element

Try:

<input :required="test ? true : false">

ReactJs: What should the PropTypes be for this.props.children?

Try a custom propTypes :

 const  childrenPropTypeLogic = (props, propName, componentName) => {
          const prop = props[propName];
          return React.Children
                   .toArray(prop)
                   .find(child => child.type !== 'div') && new Error(`${componentName} only accepts "div" elements`);
 };


static propTypes = {

   children : childrenPropTypeLogic

}

Fiddle

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_x000D_
const {Component, PropTypes} = React;_x000D_
_x000D_
 const  childrenPropTypeLogic = (props, propName, componentName) => {_x000D_
             var error;_x000D_
          var prop = props[propName];_x000D_
    _x000D_
          React.Children.forEach(prop, function (child) {_x000D_
            if (child.type !== 'div') {_x000D_
              error = new Error(_x000D_
                '`' + componentName + '` only accepts children of type `div`.'_x000D_
              );_x000D_
            }_x000D_
          });_x000D_
    _x000D_
          return error;_x000D_
    };_x000D_
    _x000D_
  _x000D_
_x000D_
class ContainerComponent extends Component {_x000D_
  static propTypes = {_x000D_
    children: childrenPropTypeLogic,_x000D_
  }_x000D_
_x000D_
  render() {_x000D_
    return (_x000D_
      <div>_x000D_
        {this.props.children}_x000D_
      </div>_x000D_
    );_x000D_
  }_x000D_
}_x000D_
_x000D_
_x000D_
_x000D_
class App extends Component {_x000D_
   render(){_x000D_
    return (_x000D_
    <ContainerComponent>_x000D_
        <div>1</div>_x000D_
        <div>2</div>_x000D_
      </ContainerComponent>_x000D_
    )_x000D_
   }_x000D_
}_x000D_
_x000D_
ReactDOM.render(<App /> , document.querySelector('section'))
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>_x000D_
_x000D_
<section />
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DELETE_FAILED_INTERNAL_ERROR Error while Installing APK

Even after following all the suggestions, if it shows error then check your buildType in Gradle.

Make sure signingConfig signingConfigs.config

is in release scope, not in debug.

How to set component default props on React component

For those using something like babel stage-2 or transform-class-properties:

import React, { PropTypes, Component } from 'react';

export default class ExampleComponent extends Component {
   static contextTypes = {
      // some context types
   };

   static propTypes = {
      prop1: PropTypes.object
   };

   static defaultProps = {
      prop1: { foobar: 'foobar' }
   };

   ...

}

Update

As of React v15.5, PropTypes was moved out of the main React Package (link):

import PropTypes from 'prop-types';

Edit

As pointed out by @johndodo, static class properties are actually not a part of the ES7 spec, but rather are currently only supported by babel. Updated to reflect that.

Render Content Dynamically from an array map function in React Native

Don't forget to return the mapped array , like:

lapsList() {

    return this.state.laps.map((data) => {
      return (
        <View><Text>{data.time}</Text></View>
      )
    })

}

Reference for the map() method: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map

'dispatch' is not a function when argument to mapToDispatchToProps() in Redux

I needed an example using React.Component so I am posting it:

import React from 'react';
import * as Redux from 'react-redux';

class NavigationHeader extends React.Component {

}

const mapStateToProps = function (store) {
    console.log(`mapStateToProps ${store}`);
    return {
        navigation: store.navigation
    };
};

export default Redux.connect(mapStateToProps)(NavigationHeader);

How to do a redirect to another route with react-router?

How to do a redirect to another route with react-router?

For example, when a user clicks a link <Link to="/" />Click to route</Link> react-router will look for / and you can use Redirect to and send the user somewhere else like the login route.

From the docs for ReactRouterTraining:

Rendering a <Redirect> will navigate to a new location. The new location will override the current location in the history stack, like server-side redirects (HTTP 3xx) do.

import { Route, Redirect } from 'react-router'

<Route exact path="/" render={() => (
  loggedIn ? (
    <Redirect to="/dashboard"/>
  ) : (
    <PublicHomePage/>
  )
)}/>

to: string, The URL to redirect to.

<Redirect to="/somewhere/else"/>

to: object, A location to redirect to.

<Redirect to={{
  pathname: '/login',
  search: '?utm=your+face',
  state: { referrer: currentLocation }
}}/>

Get div's offsetTop positions in React

  import ReactDOM from 'react-dom';
  //...
  componentDidMount() {
    var n = ReactDOM.findDOMNode(this);
    console.log(n.offsetTop);
  }

You can just grab the offsetTop from the Node.

What's the difference between Instant and LocalDateTime?

Table of all date-time types in Java, both modern and legacy

tl;dr

Instant and LocalDateTime are two entirely different animals: One represents a moment, the other does not.

  • Instant represents a moment, a specific point in the timeline.
  • LocalDateTime represents a date and a time-of-day. But lacking a time zone or offset-from-UTC, this class cannot represent a moment. It represents potential moments along a range of about 26 to 27 hours, the range of all time zones around the globe. A LocalDateTime value is inherently ambiguous.

Incorrect Presumption

LocalDateTime is rather date/clock representation including time-zones for humans.

Your statement is incorrect: A LocalDateTime has no time zone. Having no time zone is the entire point of that class.

To quote that class’ doc:

This class does not store or represent a time-zone. Instead, it is a description of the date, as used for birthdays, combined with the local time as seen on a wall clock. It cannot represent an instant on the time-line without additional information such as an offset or time-zone.

So Local… means “not zoned, no offset”.

Instant

enter image description here

An Instant is a moment on the timeline in UTC, a count of nanoseconds since the epoch of the first moment of 1970 UTC (basically, see class doc for nitty-gritty details). Since most of your business logic, data storage, and data exchange should be in UTC, this is a handy class to be used often.

Instant instant = Instant.now() ;  // Capture the current moment in UTC.

OffsetDateTime

enter image description here

The class OffsetDateTime class represents a moment as a date and time with a context of some number of hours-minutes-seconds ahead of, or behind, UTC. The amount of offset, the number of hours-minutes-seconds, is represented by the ZoneOffset class.

If the number of hours-minutes-seconds is zero, an OffsetDateTime represents a moment in UTC the same as an Instant.

ZoneOffset

enter image description here

The ZoneOffset class represents an offset-from-UTC, a number of hours-minutes-seconds ahead of UTC or behind UTC.

A ZoneOffset is merely a number of hours-minutes-seconds, nothing more. A zone is much more, having a name and a history of changes to offset. So using a zone is always preferable to using a mere offset.

ZoneId

enter image description here

A time zone is represented by the ZoneId class.

A new day dawns earlier in Paris than in Montréal, for example. So we need to move the clock’s hands to better reflect noon (when the Sun is directly overhead) for a given region. The further away eastward/westward from the UTC line in west Europe/Africa the larger the offset.

A time zone is a set of rules for handling adjustments and anomalies as practiced by a local community or region. The most common anomaly is the all-too-popular lunacy known as Daylight Saving Time (DST).

A time zone has the history of past rules, present rules, and rules confirmed for the near future.

These rules change more often than you might expect. Be sure to keep your date-time library's rules, usually a copy of the 'tz' database, up to date. Keeping up-to-date is easier than ever now in Java 8 with Oracle releasing a Timezone Updater Tool.

Specify a proper time zone name in the format of Continent/Region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 2-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).

Time Zone = Offset + Rules of Adjustments

ZoneId z = ZoneId.of( “Africa/Tunis” ) ; 

ZonedDateTime

enter image description here

Think of ZonedDateTime conceptually as an Instant with an assigned ZoneId.

ZonedDateTime = ( Instant + ZoneId )

To capture the current moment as seen in the wall-clock time used by the people of a particular region (a time zone):

ZonedDateTime zdt = ZonedDateTime.now( z ) ;  // Pass a `ZoneId` object such as `ZoneId.of( "Europe/Paris" )`. 

Nearly all of your backend, database, business logic, data persistence, data exchange should all be in UTC. But for presentation to users you need to adjust into a time zone expected by the user. This is the purpose of the ZonedDateTime class and the formatter classes used to generate String representations of those date-time values.

ZonedDateTime zdt = instant.atZone( z ) ;
String output = zdt.toString() ;                 // Standard ISO 8601 format.

You can generate text in localized format using DateTimeFormatter.

DateTimeFormatter f = DateTimeFormatter.ofLocalizedDateTime( FormatStyle.FULL ).withLocale( Locale.CANADA_FRENCH ) ; 
String outputFormatted = zdt.format( f ) ;

mardi 30 avril 2019 à 23 h 22 min 55 s heure de l’Inde

LocalDate, LocalTime, LocalDateTime

Diagram showing only a calendar for a LocalDate.

Diagram showing only a clock for a LocalTime.

Diagram showing a calendar plus clock for a LocalDateTime.

The "local" date time classes, LocalDateTime, LocalDate, LocalTime, are a different kind of critter. The are not tied to any one locality or time zone. They are not tied to the timeline. They have no real meaning until you apply them to a locality to find a point on the timeline.

The word “Local” in these class names may be counter-intuitive to the uninitiated. The word means any locality, or every locality, but not a particular locality.

So for business apps, the "Local" types are not often used as they represent just the general idea of a possible date or time not a specific moment on the timeline. Business apps tend to care about the exact moment an invoice arrived, a product shipped for transport, an employee was hired, or the taxi left the garage. So business app developers use Instant and ZonedDateTime classes most commonly.

So when would we use LocalDateTime? In three situations:

  • We want to apply a certain date and time-of-day across multiple locations.
  • We are booking appointments.
  • We have an intended yet undetermined time zone.

Notice that none of these three cases involve a single certain specific point on the timeline, none of these are a moment.

One time-of-day, multiple moments

Sometimes we want to represent a certain time-of-day on a certain date, but want to apply that into multiple localities across time zones.

For example, "Christmas starts at midnight on the 25th of December 2015" is a LocalDateTime. Midnight strikes at different moments in Paris than in Montréal, and different again in Seattle and in Auckland.

LocalDate ld = LocalDate.of( 2018 , Month.DECEMBER , 25 ) ;
LocalTime lt = LocalTime.MIN ;   // 00:00:00
LocalDateTime ldt = LocalDateTime.of( ld , lt ) ;  // Christmas morning anywhere. 

Another example, "Acme Company has a policy that lunchtime starts at 12:30 PM at each of its factories worldwide" is a LocalTime. To have real meaning you need to apply it to the timeline to figure the moment of 12:30 at the Stuttgart factory or 12:30 at the Rabat factory or 12:30 at the Sydney factory.

Booking appointments

Another situation to use LocalDateTime is for booking future events (ex: Dentist appointments). These appointments may be far enough out in the future that you risk politicians redefining the time zone. Politicians often give little forewarning, or even no warning at all. If you mean "3 PM next January 23rd" regardless of how the politicians may play with the clock, then you cannot record a moment – that would see 3 PM turn into 2 PM or 4 PM if that region adopted or dropped Daylight Saving Time, for example.

For appointments, store a LocalDateTime and a ZoneId, kept separately. Later, when generating a schedule, on-the-fly determine a moment by calling LocalDateTime::atZone( ZoneId ) to generate a ZonedDateTime object.

ZonedDateTime zdt = ldt.atZone( z ) ;  // Given a date, a time-of-day, and a time zone, determine a moment, a point on the timeline.

If needed, you can adjust to UTC. Extract an Instant from the ZonedDateTime.

Instant instant = zdt.toInstant() ;  // Adjust from some zone to UTC. Same moment, same point on the timeline, different wall-clock time.

Unknown zone

Some people might use LocalDateTime in a situation where the time zone or offset is unknown.

I consider this case inappropriate and unwise. If a zone or offset is intended but undetermined, you have bad data. That would be like storing a price of a product without knowing the intended currency (dollars, pounds, euros, etc.). Not a good idea.

All date-time types

For completeness, here is a table of all the possible date-time types, both modern and legacy in Java, as well as those defined by the SQL standard. This might help to place the Instant & LocalDateTime classes in a larger context.

Table of all date-time types in Java (both modern & legacy) as well as SQL standard.

Notice the odd choices made by the Java team in designing JDBC 4.2. They chose to support all the java.time times… except for the two most commonly used classes: Instant & ZonedDateTime.

But not to worry. We can easily convert back and forth.

Converting Instant.

// Storing
OffsetDateTime odt = instant.atOffset( ZoneOffset.UTC ) ;
myPreparedStatement.setObject( … , odt ) ;

// Retrieving
OffsetDateTime odt = myResultSet.getObject( … , OffsetDateTime.class ) ;
Instant instant = odt.toInstant() ;

Converting ZonedDateTime.

// Storing
OffsetDateTime odt = zdt.toOffsetDateTime() ;
myPreparedStatement.setObject( … , odt ) ;

// Retrieving
OffsetDateTime odt = myResultSet.getObject( … , OffsetDateTime.class ) ;
ZoneId z = ZoneId.of( "Asia/Kolkata" ) ;
ZonedDateTime zdt = odt.atZone( z ) ; 

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes. Hibernate 5 & JPA 2.2 support java.time.

Where to obtain the java.time classes?

Table of which java.time library to use with which version of Java or Android

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

React proptype array with shape

If I am to define the same proptypes for a particular shape multiple times, I like abstract it out to a proptypes file so that if the shape of the object changes, I only have to change the code in one place. It helps dry up the codebase a bit.

Example:

// Inside my proptypes.js file
import PT from 'prop-types';

export const product = {
  id: PT.number.isRequired,
  title: PT.string.isRequired,
  sku: PT.string.isRequired,
  description: PT.string.isRequired,
};


// Inside my component file
import PT from 'prop-types';
import { product } from './proptypes;


List.propTypes = {
  productList: PT.arrayOf(product)
}

Docker Compose wait for container X before starting Y

Quite recently they've added the depends_on feature.

Edit:

As of compose version 2.1+ till version 3 you can use depends_on in conjunction with healthcheck to achieve this:

From the docs:

version: '2.1'
services:
  web:
    build: .
    depends_on:
      db:
        condition: service_healthy
      redis:
        condition: service_started
  redis:
    image: redis
  db:
    image: redis
    healthcheck:
      test: "exit 0"

Before version 2.1

You can still use depends_on, but it only effects the order in which services are started - not if they are ready before the dependant service is started.

It seems to require at least version 1.6.0.

Usage would look something like this:

version: '2'
services:
  web:
    build: .
    depends_on:
      - db
      - redis
  redis:
    image: redis
  db:
    image: postgres 

From the docs:

Express dependency between services, which has two effects:

  • docker-compose up will start services in dependency order. In the following example, db and redis will be started before web.
  • docker-compose up SERVICE will automatically include SERVICE’s dependencies. In the following example, docker-compose up web will also create and start db and redis.

Note: As I understand it, although this does set the order in which containers are loaded. It does not guarantee that the service inside the container has actually loaded.

For example, you postgres container might be up. But the postgres service itself might still be initializing within the container.

How do I conditionally add attributes to React components?

Considering the post JSX In Depth, you can solve your problem this way:

if (isRequired) {
  return (
    <MyOwnInput name="test" required='required' />
  );
}
return (
    <MyOwnInput name="test" />
);

Check for internet connection with Swift

Use this for Swift-5+

import Foundation
import UIKit
import SystemConfiguration

public class InternetConnectionManager {
    
    
    private init() {
        
    }
    
    public static func isConnectedToNetwork() -> Bool {
        
        var zeroAddress = sockaddr_in()
        zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
        zeroAddress.sin_family = sa_family_t(AF_INET)
        guard let defaultRouteReachability = withUnsafePointer(to: &zeroAddress, {
            
            $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
                
                SCNetworkReachabilityCreateWithAddress(nil, $0)
                
            }
            
        }) else {
            
            return false
        }
        var flags = SCNetworkReachabilityFlags()
        if !SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) {
            return false
        }
        let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0
        let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0
        return (isReachable && !needsConnection)
    }
    
}

Usage:

if InternetConnectionManager.isConnectedToNetwork(){
    print("Connected")
}else{
    print("Not Connected")
}

Or Just use this framework for more Utilities: Link

Handling errors in Promise.all

That's how Promise.all is designed to work. If a single promise reject()'s, the entire method immediately fails.

There are use cases where one might want to have the Promise.all allowing for promises to fail. To make this happen, simply don't use any reject() statements in your promise. However, to ensure your app/script does not freeze in case any single underlying promise never gets a response, you need to put a timeout on it.

function getThing(uid,branch){
    return new Promise(function (resolve, reject) {
        xhr.get().then(function(res) {
            if (res) {
                resolve(res);
            } 
            else {
                resolve(null);
            }
            setTimeout(function(){reject('timeout')},10000)
        }).catch(function(error) {
            resolve(null);
        });
    });
}

How to compare two JSON objects with the same elements in a different order equal?

Decode them and compare them as mgilson comment.

Order does not matter for dictionary as long as the keys, and values matches. (Dictionary has no order in Python)

>>> {'a': 1, 'b': 2} == {'b': 2, 'a': 1}
True

But order is important in list; sorting will solve the problem for the lists.

>>> [1, 2] == [2, 1]
False
>>> [1, 2] == sorted([2, 1])
True

>>> a = '{"errors": [{"error": "invalid", "field": "email"}, {"error": "required", "field": "name"}], "success": false}'
>>> b = '{"errors": [{"error": "required", "field": "name"}, {"error": "invalid", "field": "email"}], "success": false}'
>>> a, b = json.loads(a), json.loads(b)
>>> a['errors'].sort()
>>> b['errors'].sort()
>>> a == b
True

Above example will work for the JSON in the question. For general solution, see Zero Piraeus's answer.

Fill remaining vertical space with CSS using display:flex

Make it simple : DEMO

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_x000D_
section {_x000D_
  display: flex;_x000D_
  flex-flow: column;_x000D_
  height: 300px;_x000D_
}_x000D_
_x000D_
header {_x000D_
  background: tomato;_x000D_
  /* no flex rules, it will grow */_x000D_
}_x000D_
_x000D_
div {_x000D_
  flex: 1;  /* 1 and it will fill whole space left if no flex value are set to other children*/_x000D_
  background: gold;_x000D_
  overflow: auto;_x000D_
}_x000D_
_x000D_
footer {_x000D_
  background: lightgreen;_x000D_
  min-height: 60px;  /* min-height has its purpose :) , unless you meant height*/_x000D_
}
_x000D_
<section>_x000D_
  <header>_x000D_
    header: sized to content_x000D_
    <br/>(but is it really?)_x000D_
  </header>_x000D_
  <div>_x000D_
    main content: fills remaining space<br> x_x000D_
    <br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>_x000D_
    <!-- uncomment to see it break -->_x000D_
    x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br> x_x000D_
    <br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br> x_x000D_
    <br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br> x_x000D_
    <br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>_x000D_
    <!-- -->_x000D_
  </div>_x000D_
  <footer>_x000D_
    footer: fixed height in px_x000D_
  </footer>_x000D_
</section>
_x000D_
_x000D_
_x000D_

Full screen version

_x000D_
_x000D_
section {_x000D_
  display: flex;_x000D_
  flex-flow: column;_x000D_
  height: 100vh;_x000D_
}_x000D_
_x000D_
header {_x000D_
  background: tomato;_x000D_
  /* no flex rules, it will grow */_x000D_
}_x000D_
_x000D_
div {_x000D_
  flex: 1;_x000D_
  /* 1 and it will fill whole space left if no flex value are set to other children*/_x000D_
  background: gold;_x000D_
  overflow: auto;_x000D_
}_x000D_
_x000D_
footer {_x000D_
  background: lightgreen;_x000D_
  min-height: 60px;_x000D_
  /* min-height has its purpose :) , unless you meant height*/_x000D_
}_x000D_
_x000D_
body {_x000D_
  margin: 0;_x000D_
}
_x000D_
<section>_x000D_
  <header>_x000D_
    header: sized to content_x000D_
    <br/>(but is it really?)_x000D_
  </header>_x000D_
  <div>_x000D_
    main content: fills remaining space<br> x_x000D_
    <br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>_x000D_
    <!-- uncomment to see it break -->_x000D_
    x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br> x_x000D_
    <br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br> x_x000D_
    <br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br> x_x000D_
    <br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>_x000D_
    <!-- -->_x000D_
  </div>_x000D_
  <footer>_x000D_
    footer: fixed height in px_x000D_
  </footer>_x000D_
</section>
_x000D_
_x000D_
_x000D_

No function matches the given name and argument types

In my particular case the function was actually missing. The error message is the same. I am using the Postgresql plugin PostGIS and I had to reinstall that for whatever reason.

How to show imageView full screen on imageView click?

It's easy to achieve this is to just use an Intent like this: (I put the method in a custom class that takes in an Activity as a parameter so it can be called from any Fragment or Activity)

    public class UIutils {

private Activity mActivity;

    public UIutils(Activity activity){
        mActivity = activity;
    }

public void showPhoto(Uri photoUri){
        Intent intent = new Intent();
        intent.setAction(Intent.ACTION_VIEW);
        intent.setDataAndType(photoUri, "image/*");
        mActivity.startActivity(intent);
    }
}

Then to use it just do this:

imageView.setOnClickListener(v1 -> new UIutils(getActivity()).showPhoto(Uri.parse(imageURI)));

I use this with an Image URL but it can be used with stored files as well. If you are accessing images form the phones memory you should use a content provider.

Could not load file or assembly 'Newtonsoft.Json' or one of its dependencies. Manifest definition does not match the assembly reference

None of the answers, including the checked one did not work for me.

The solution was far more simple. I first removed the references from my BUS layer. Then deleted the dll's from the project (to make sure it's gone), then reinstalled JSON.NET from nuget packeges. And, the tricky part was, "turning it off and on again".

I just restarted visual studio, and there it worked!

So, if you try everything possible and still can't solve the problem, just try turning visual studio off and on again, it might help.

Convert Json String to C# Object List

public static class Helper
{
    public static string AsJsonList<T>(List<T> tt)
    {
        return new JavaScriptSerializer().Serialize(tt);
    }
    public static string AsJson<T>(T t)
    {
        return new JavaScriptSerializer().Serialize(t);
    }
    public static List<T> AsObjectList<T>(string tt)
    {
        return new JavaScriptSerializer().Deserialize<List<T>>(tt);
    }
    public static T AsObject<T>(string t)
    {
        return new JavaScriptSerializer().Deserialize<T>(t);
    }
}

Difference between IISRESET and IIS Stop-Start command

Take IISReset as a suite of commands that helps you manage IIS start / stop etc.

Which means you need to specify option (/switch) what you want to do to carry any operation.

Default behavior OR default switch is /restart with iisreset so you do not need to run command twice with /start and /stop.

Hope this clarifies your question. For reference the output of iisreset /? is:

IISRESET.EXE (c) Microsoft Corp. 1998-2005

Usage:
iisreset [computername]

    /RESTART            Stop and then restart all Internet services.
    /START              Start all Internet services.
    /STOP               Stop all Internet services.
    /REBOOT             Reboot the computer.
    /REBOOTONERROR      Reboot the computer if an error occurs when starting,
                        stopping, or restarting Internet services.
    /NOFORCE            Do not forcefully terminate Internet services if
                        attempting to stop them gracefully fails.
    /TIMEOUT:val        Specify the timeout value ( in seconds ) to wait for
                        a successful stop of Internet services. On expiration
                        of this timeout the computer can be rebooted if
                        the /REBOOTONERROR parameter is specified.
                        The default value is 20s for restart, 60s for stop,
                        and 0s for reboot.
    /STATUS             Display the status of all Internet services.
    /ENABLE             Enable restarting of Internet Services
                        on the local system.
    /DISABLE            Disable restarting of Internet Services
                        on the local system.

Mean per group in a data.frame

Here are a variety of ways to do this in base R including an alternative aggregate approach. The examples below return means per month, which I think is what you requested. Although, the same approach could be used to return means per person:

Using ave:

my.data <- read.table(text = '
     Name     Month  Rate1     Rate2
     Aira       1      12        23
     Aira       2      18        73
     Aira       3      19        45
     Ben        1      53        19
     Ben        2      22        87
     Ben        3      19        45
     Cat        1      22        87
     Cat        2      67        43
     Cat        3      45        32
', header = TRUE, stringsAsFactors = FALSE, na.strings = 'NA')

Rate1.mean <- with(my.data, ave(Rate1, Month, FUN = function(x) mean(x, na.rm = TRUE)))
Rate2.mean <- with(my.data, ave(Rate2, Month, FUN = function(x) mean(x, na.rm = TRUE)))

my.data <- data.frame(my.data, Rate1.mean, Rate2.mean)
my.data

Using by:

my.data <- read.table(text = '
     Name     Month  Rate1     Rate2
     Aira       1      12        23
     Aira       2      18        73
     Aira       3      19        45
     Ben        1      53        19
     Ben        2      22        87
     Ben        3      19        45
     Cat        1      22        87
     Cat        2      67        43
     Cat        3      45        32
', header = TRUE, stringsAsFactors = FALSE, na.strings = 'NA')

by.month <- as.data.frame(do.call("rbind", by(my.data, my.data$Month, FUN = function(x) colMeans(x[,3:4]))))
colnames(by.month) <- c('Rate1.mean', 'Rate2.mean')
by.month <- cbind(Month = rownames(by.month), by.month)

my.data <- merge(my.data, by.month, by = 'Month')
my.data

Using lapply and split:

my.data <- read.table(text = '
     Name     Month  Rate1     Rate2
     Aira       1      12        23
     Aira       2      18        73
     Aira       3      19        45
     Ben        1      53        19
     Ben        2      22        87
     Ben        3      19        45
     Cat        1      22        87
     Cat        2      67        43
     Cat        3      45        32
', header = TRUE, stringsAsFactors = FALSE, na.strings = 'NA')

ly.mean <- lapply(split(my.data, my.data$Month), function(x) c(Mean = colMeans(x[,3:4])))
ly.mean <- as.data.frame(do.call("rbind", ly.mean))
ly.mean <- cbind(Month = rownames(ly.mean), ly.mean)

my.data <- merge(my.data, ly.mean, by = 'Month')
my.data

Using sapply and split:

my.data <- read.table(text = '
     Name     Month  Rate1     Rate2
     Aira       1      12        23
     Aira       2      18        73
     Aira       3      19        45
     Ben        1      53        19
     Ben        2      22        87
     Ben        3      19        45
     Cat        1      22        87
     Cat        2      67        43
     Cat        3      45        32
', header = TRUE, stringsAsFactors = FALSE, na.strings = 'NA')
my.data

sy.mean <- t(sapply(split(my.data, my.data$Month), function(x) colMeans(x[,3:4])))
colnames(sy.mean) <- c('Rate1.mean', 'Rate2.mean')
sy.mean <- data.frame(Month = rownames(sy.mean), sy.mean, stringsAsFactors = FALSE)
my.data <- merge(my.data, sy.mean, by = 'Month')
my.data

Using aggregate:

my.data <- read.table(text = '
     Name     Month  Rate1     Rate2
     Aira       1      12        23
     Aira       2      18        73
     Aira       3      19        45
     Ben        1      53        19
     Ben        2      22        87
     Ben        3      19        45
     Cat        1      22        87
     Cat        2      67        43
     Cat        3      45        32
', header = TRUE, stringsAsFactors = FALSE, na.strings = 'NA')

my.summary <- with(my.data, aggregate(list(Rate1, Rate2), by = list(Month), 
                   FUN = function(x) { mon.mean = mean(x, na.rm = TRUE) } ))

my.summary <- do.call(data.frame, my.summary)
colnames(my.summary) <- c('Month', 'Rate1.mean', 'Rate2.mean')
my.summary

my.data <- merge(my.data, my.summary, by = 'Month')
my.data

EDIT: June 28, 2020

Here I use aggregate to obtain the column means of an entire matrix by group where group is defined in an external vector:

my.group <- c(1,2,1,2,2,3,1,2,3,3)

my.data <- matrix(c(   1,    2,    3,    4,    5,
                      10,   20,   30,   40,   50,
                       2,    4,    6,    8,   10,
                      20,   30,   40,   50,   60,
                      20,   18,   16,   14,   12,
                    1000, 1100, 1200, 1300, 1400,
                       2,    3,    4,    3,    2,
                      50,   40,   30,   20,   10,
                    1001, 2001, 3001, 4001, 5001,
                    1000, 2000, 3000, 4000, 5000), nrow = 10, ncol = 5, byrow = TRUE)
my.data

my.summary <- aggregate(list(my.data), by = list(my.group), FUN = function(x) { my.mean = mean(x, na.rm = TRUE) } )
my.summary
#  Group.1          X1       X2          X3       X4          X5
#1       1    1.666667    3.000    4.333333    5.000    5.666667
#2       2   25.000000   27.000   29.000000   31.000   33.000000
#3       3 1000.333333 1700.333 2400.333333 3100.333 3800.333333

How to tell Maven to disregard SSL errors (and trusting all certs)?

Create a folder ${USER_HOME}/.mvn and put a file called maven.config in it.

The content should be:

-Dmaven.wagon.http.ssl.insecure=true
-Dmaven.wagon.http.ssl.allowall=true
-Dmaven.wagon.http.ssl.ignore.validity.dates=true

Hope this helps.

No Main class found in NetBeans

The connections I made in preparing this for posting really cleared it up for me, once and for all. It's not completely obvious what goes in the Main Class: box until you see the connections. (Note that the class containing the main method need not necessarily be named Main but the main method can have no other name.)

enter image description here

How to make all controls resize accordingly proportionally when window is maximized?

Well, it's fairly simple to do.

On the window resize event handler, calculate how much the window has grown/shrunk, and use that fraction to adjust 1) Height, 2) Width, 3) Canvas.Top, 4) Canvas.Left properties of all the child controls inside the canvas.

Here's the code:

private void window1_SizeChanged(object sender, SizeChangedEventArgs e)
        {
            myCanvas.Width = e.NewSize.Width;
            myCanvas.Height = e.NewSize.Height;

            double xChange = 1, yChange = 1;

            if (e.PreviousSize.Width != 0)
            xChange = (e.NewSize.Width/e.PreviousSize.Width);

            if (e.PreviousSize.Height != 0)
            yChange = (e.NewSize.Height / e.PreviousSize.Height);

            foreach (FrameworkElement fe in myCanvas.Children )
            {   
                /*because I didn't want to resize the grid I'm having inside the canvas in this particular instance. (doing that from xaml) */            
                if (fe is Grid == false)
                {
                    fe.Height = fe.ActualHeight * yChange;
                    fe.Width = fe.ActualWidth * xChange;

                    Canvas.SetTop(fe, Canvas.GetTop(fe) * yChange);
                    Canvas.SetLeft(fe, Canvas.GetLeft(fe) * xChange);

                }
            }
        }

Change language for bootstrap DateTimePicker

If you use moment.js the you need to load moment-with-locales.min.js not moment.min.js. Otherwise, your locale: 'ru' will not work.

Transaction marked as rollback only: How do I find the cause

I finally understood the problem:

methodA() {
    methodB()
}

@Transactional(noRollbackFor = Exception.class)
methodB() {
    ...
    try {
        methodC()
    } catch (...) {...}
    log("OK");
}

@Transactional
methodC() {
    throw new ...();
}

What happens is that even though the methodB has the right annotation, the methodC does not. When the exception is thrown, the second @Transactional marks the first transaction as Rollback only anyway.

How do I toggle an ng-show in AngularJS based on a boolean?

If based on click here it is:

ng-click="orderReverse = orderReverse ? false : true"

Npm install failed with "cannot run in wd"

OP here, I have learned a lot more about node since I first asked this question. Though Dmitry's answer was very helpful, what ultimately did it for me is to install node with the correct permissions.

I highly recommend not installing node using any package managers, but rather to compile it yourself so that it resides in a local directory with normal permissions.

This article provides a very clear step-by-step instruction of how to do so:

https://www.digitalocean.com/community/tutorials/how-to-install-an-upstream-version-of-node-js-on-ubuntu-12-04

Error LNK2019: Unresolved External Symbol in Visual Studio

I was getting this error after adding the include files and linking the library. It was because the lib was built with non-unicode and my application was unicode. Matching them fixed it.

I'm getting the "missing a using directive or assembly reference" and no clue what's going wrong

The following technique worked for me:

1) Right click on the project Solution -> Click on Clean solution

2) Right click on the project Solution -> Click on Rebuild solution

$location / switching between html5 and hashbang mode / link rewriting

I wanted to be able to access my application with the HTML5 mode and a fixed token and then switch to the hashbang method (to keep the token so the user can refresh his page).

URL for accessing my app:

http://myapp.com/amazing_url?token=super_token

Then when the user loads the page:

http://myapp.com/amazing_url?token=super_token#/amazing_url

Then when the user navigates:

http://myapp.com/amazing_url?token=super_token#/another_url

With this I keep the token in the URL and keep the state when the user is browsing. I lost a bit of visibility of the URL, but there is no perfect way of doing it.

So don't enable the HTML5 mode and then add this controller:

.config ($stateProvider)->
    $stateProvider.state('home-loading', {
         url: '/',
         controller: 'homeController'
    })
.controller 'homeController', ($state, $location)->
    if window.location.pathname != '/'
        $location.url(window.location.pathname+window.location.search).replace()
    else
        $state.go('home', {}, { location: 'replace' })

Wpf DataGrid Add new row

Try this MSDN blog

Also, try the following example:

Xaml:

   <DataGrid AutoGenerateColumns="False" Name="DataGridTest" CanUserAddRows="True" ItemsSource="{Binding TestBinding}" Margin="0,50,0,0" >
        <DataGrid.Columns>
            <DataGridTextColumn Header="Line" IsReadOnly="True" Binding="{Binding Path=Test1}" Width="50"></DataGridTextColumn>
            <DataGridTextColumn Header="Account" IsReadOnly="True"  Binding="{Binding Path=Test2}" Width="130"></DataGridTextColumn>
        </DataGrid.Columns>
    </DataGrid>
    <Button Content="Add new row" HorizontalAlignment="Left" Margin="0,10,0,0" VerticalAlignment="Top" Width="75" Click="Button_Click_1"/>

CS:

 /// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void Button_Click_1(object sender, RoutedEventArgs e)
    {
        var data = new Test { Test1 = "Test1", Test2 = "Test2" };

        DataGridTest.Items.Add(data);
    }
}

public class Test
{
    public string Test1 { get; set; }
    public string Test2 { get; set; }
}

AngularJS : The correct way of binding to a service properties

I think this question has a contextual component.

If you're simply pulling data from a service & radiating that information to it's view, I think binding directly to the service property is just fine. I don't want to write a lot of boilerplate code to simply map service properties to model properties to consume in my view.

Further, performance in angular is based on two things. The first is how many bindings are on a page. The second is how expensive getter functions are. Misko talks about this here

If you need to perform instance specific logic on the service data (as opposed to data massaging applied within the service itself), and the outcome of this impacts the data model exposed to the view, then I would say a $watcher is appropriate, as long as the function isn't terribly expensive. In the case of an expensive function, I would suggest caching the results in a local (to controller) variable, performing your complex operations outside of the $watcher function, and then binding your scope to the result of that.

As a caveat, you shouldn't be hanging any properties directly off your $scope. The $scope variable is NOT your model. It has references to your model.

In my mind, "best practice" for simply radiating information from service down to view:

function TimerCtrl1($scope, Timer) {
  $scope.model = {timerData: Timer.data};
};

And then your view would contain {{model.timerData.lastupdated}}.

How do I read a file line by line in VB Script?

If anyone like me is searching to read only a specific line, example only line 18 here is the code:

filename = "C:\log.log"

Set fso = CreateObject("Scripting.FileSystemObject")
Set f = fso.OpenTextFile(filename)

For i = 1 to 17
    f.ReadLine
Next

strLine = f.ReadLine
Wscript.Echo strLine

f.Close

Passing Parameters JavaFX FXML

You can decide to use a public observable list to store public data, or just create a public setter method to store data and retrieve from the corresponding controller

Google Maps Android API v2 - Interactive InfoWindow (like in original android google maps)

Just a speculation, I have not enough experience to try it... )-:

Since GoogleMap is a fragment, it should be possible to catch marker onClick event and show custom fragment view. A map fragment will be still visible on the background. Does anybody tried it? Any reason why it could not work?

The disadvantage is that map fragment would be freezed on backgroud, until a custom info fragment return control to it.

Java Read Large Text File With 70million line of text

I tried the following three methods, my file size is 1M, and I got results:

enter image description here

I run the program several times it looks that BufferedReader is faster.

@Test
public void testLargeFileIO_Scanner() throws Exception {

    long start = new Date().getTime();

    String fileName = "/Downloads/SampleTextFile_1000kb.txt"; //this path is on my local
    InputStream inputStream = new FileInputStream(fileName);

    try (Scanner fileScanner = new Scanner(inputStream, StandardCharsets.UTF_8.name())) {
        while (fileScanner.hasNextLine()) {
            String line = fileScanner.nextLine();
            //System.out.println(line);
        }
    }
    long end = new Date().getTime();

    long time = end - start;
    System.out.println("Scanner Time Consumed => " + time);

}


@Test
 public void testLargeFileIO_BufferedReader() throws Exception {

    long start = new Date().getTime();

    String fileName = "/Downloads/SampleTextFile_1000kb.txt"; //this path is on my local
    try (BufferedReader fileBufferReader = new BufferedReader(new FileReader(fileName))) {
        String fileLineContent;
        while ((fileLineContent = fileBufferReader.readLine()) != null) {
            //System.out.println(fileLineContent);
        }
    }
    long end = new Date().getTime();

    long time = (long) (end - start);
    System.out.println("BufferedReader Time Consumed => " + time);

}


@Test
public void testLargeFileIO_Stream() throws Exception {

    long start = new Date().getTime();

    String fileName = "/Downloads/SampleTextFile_1000kb.txt"; //this path is on my local
    try (Stream inputStream = Files.lines(Paths.get(fileName), StandardCharsets.UTF_8)) {
        //inputStream.forEach(System.out::println);
    }
    long end = new Date().getTime();

    long time = end - start;
    System.out.println("Stream Time Consumed => " + time);

}

Setting font on NSAttributedString on UITextView disregards line spacing

I found your question because I was also fighting with NSAttributedString. For me, the beginEditing and endEditing methods did the trick, like stated in Changing an Attributed String. Apart from that, the lineSpacing is set with setLineSpacing on the paragraphStyle.

So you might want to try changing your code to:

NSString *string = @" Hello \n world";
attrString = [[NSMutableAttributedString alloc] initWithString:string];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle defaultParagraphStyle] mutableCopy];

[paragraphStyle setLineSpacing:20]  // Or whatever (positive) value you like...    
[attrSting beginEditing];

[attrString addAttribute:NSFontAttributeName value:[UIFont boldSystemFontOfSize:20] range:NSMakeRange(0, string.length)];
[attrString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, string.length)];

[attrString endEditing];

mainTextView.attributedText = attrString;

Didn't test this exact code though, btw, but mine looks nearly the same.

EDIT:

Meanwhile, I've tested it, and, correct me if I'm wrong, the - beginEditing and - endEditing calls seem to be of quite an importance.

Insert using LEFT JOIN and INNER JOIN

you can't use VALUES clause when inserting data using another SELECT query. see INSERT SYNTAX

INSERT INTO user
(
 id, name, username, email, opted_in
)
(
    SELECT id, name, username, email, opted_in
    FROM user
         LEFT JOIN user_permission AS userPerm
            ON user.id = userPerm.user_id
);

Should I use px or rem value units in my CSS?

josh3736's answer is a good one, but to provide a counterpoint 3 years later:

I recommend using rem units for fonts, if only because it makes it easier for you, the developer, to change sizes. It's true that users very rarely change the default font size in their browsers, and that modern browser zoom will scale up px units. But what if your boss comes to you and says "don't enlarge the images or icons, but make all the fonts bigger". It's much easier to just change the root font size and let all the other fonts scale relative to that, then to change px sizes in dozens or hundreds of css rules.

I think it still makes sense to use px units for some images, or for certain layout elements that should always be the same size regardless of the scale of the design.

Caniuse.com may have said that only 75% of browsers when josh3736 posted his answer in 2012, but as of March 27 they claim 93.78% support. Only IE8 doesn't support it among the browsers they track.

How to ping an IP address


Just an addition to what others have given, even though they work well but in some cases if internet is slow or some unknown network problem exists, some of the codes won't work (isReachable()). But this code mentioned below creates a process which acts as a command line ping (cmd ping) to windows. It works for me in all cases, tried and tested.

Code :-

public class JavaPingApp {

public static void runSystemCommand(String command) {

    try {
        Process p = Runtime.getRuntime().exec(command);
        BufferedReader inputStream = new BufferedReader(
                new InputStreamReader(p.getInputStream()));

        String s = "";
        // reading output stream of the command
        while ((s = inputStream.readLine()) != null) {
            System.out.println(s);
        }

    } catch (Exception e) {
        e.printStackTrace();
    }
}

public static void main(String[] args) {

    String ip = "stackoverflow.com"; //Any IP Address on your network / Web
    runSystemCommand("ping " + ip);
}
}

Hope it helps, Cheers!!!

Restricting JTextField input to Integers

When you type integer numbers to JtextField1 after key release it will go to inside try , for any other character it will throw NumberFormatException. If you set empty string to jTextField1 inside the catch so the user cannot type any other keys except positive numbers because JTextField1 will be cleared for each bad attempt.

 //Fields 
int x;
JTextField jTextField1;

 //Gui Code Here

private void jTextField1KeyReleased(java.awt.event.KeyEvent evt) {                                        
    try {
        x = Integer.parseInt(jTextField1.getText());
    } catch (NumberFormatException nfe) {
        jTextField1.setText("");
    }
}   

MVC 4 @Scripts "does not exist"

Create a new MVC 4 RC internet application and run it. Navigate to Login which uses the same code

 @section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
}

What allows Login.cshtml to work is the the Views\Web.config file (not the app root version) contains

<namespaces>

    <add namespace="System.Web.Optimization"/>

  </namespaces>

Why is your Create view not working and Login is?

configure: error: C compiler cannot create executables

I just had this issue building react-native app when I try to install Pod. I had to export 2 variables:

export CC=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc
CPP='/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc -E'

Does the join order matter in SQL?

For INNER joins, no, the order doesn't matter. The queries will return same results, as long as you change your selects from SELECT * to SELECT a.*, b.*, c.*.


For (LEFT, RIGHT or FULL) OUTER joins, yes, the order matters - and (updated) things are much more complicated.

First, outer joins are not commutative, so a LEFT JOIN b is not the same as b LEFT JOIN a

Outer joins are not associative either, so in your examples which involve both (commutativity and associativity) properties:

a LEFT JOIN b 
    ON b.ab_id = a.ab_id
  LEFT JOIN c
    ON c.ac_id = a.ac_id

is equivalent to:

a LEFT JOIN c 
    ON c.ac_id = a.ac_id
  LEFT JOIN b
    ON b.ab_id = a.ab_id

but:

a LEFT JOIN b 
    ON  b.ab_id = a.ab_id
  LEFT JOIN c
    ON  c.ac_id = a.ac_id
    AND c.bc_id = b.bc_id

is not equivalent to:

a LEFT JOIN c 
    ON  c.ac_id = a.ac_id
  LEFT JOIN b
    ON  b.ab_id = a.ab_id
    AND b.bc_id = c.bc_id

Another (hopefully simpler) associativity example. Think of this as (a LEFT JOIN b) LEFT JOIN c:

a LEFT JOIN b 
    ON b.ab_id = a.ab_id          -- AB condition
 LEFT JOIN c
    ON c.bc_id = b.bc_id          -- BC condition

This is equivalent to a LEFT JOIN (b LEFT JOIN c):

a LEFT JOIN  
    b LEFT JOIN c
        ON c.bc_id = b.bc_id          -- BC condition
    ON b.ab_id = a.ab_id          -- AB condition

only because we have "nice" ON conditions. Both ON b.ab_id = a.ab_id and c.bc_id = b.bc_id are equality checks and do not involve NULL comparisons.

You can even have conditions with other operators or more complex ones like: ON a.x <= b.x or ON a.x = 7 or ON a.x LIKE b.x or ON (a.x, a.y) = (b.x, b.y) and the two queries would still be equivalent.

If however, any of these involved IS NULL or a function that is related to nulls like COALESCE(), for example if the condition was b.ab_id IS NULL, then the two queries would not be equivalent.

Understanding the Linux oom-killer's logs

Sum of total_vm is 847170 and sum of rss is 214726, these two values are counted in 4kB pages, which means when oom-killer was running, you had used 214726*4kB=858904kB physical memory and swap space.

Since your physical memory is 1GB and ~200MB was used for memory mapping, it's reasonable for invoking oom-killer when 858904kB was used.

rss for process 2603 is 181503, which means 181503*4KB=726012 rss, was equal to sum of anon-rss and file-rss.

[11686.043647] Killed process 2603 (flasherav) total-vm:1498536kB, anon-rss:721784kB, file-rss:4228kB

How to get data by SqlDataReader.GetValue by column name

thisReader.GetString(int columnIndex)

Pull is not possible because you have unmerged files, git stash doesn't work. Don't want to commit

git fetch origin
git reset --hard origin/master
git pull

Explanation:

  • Fetch will download everything from another repository, in this case, the one marked as "origin".
  • Reset will discard changes and revert to the mentioned branch, "master" in repository "origin".
  • Pull will just get everything from a remote repository and integrate.

See documentation at http://git-scm.com/docs.

Date formatting in WPF datagrid

Binding="{Binding YourColumn ,StringFormat='yyyy-MM-dd'}"

Android Fragment no view found for ID?

The solution was to use getChildFragmentManager()

instead of getFragmentManager()

when calling from a fragment. If you are calling the method from an activity, then use getFragmentManager().

That will solve the problem.

Set default value of javascript object attributes

my code is:

function(s){
    s = {
        top: s.top || 100,    // default value or s.top
        left: s.left || 300,  // default value or s.left
    }
    alert(s.top)
}

Oracle PL/SQL - Raise User-Defined Exception With Custom SQLERRM

Yes. You just have to use the RAISE_APPLICATION_ERROR function. If you also want to name your exception, you'll need to use the EXCEPTION_INIT pragma in order to associate the error number to the named exception. Something like

SQL> ed
Wrote file afiedt.buf

  1  declare
  2    ex_custom EXCEPTION;
  3    PRAGMA EXCEPTION_INIT( ex_custom, -20001 );
  4  begin
  5    raise_application_error( -20001, 'This is a custom error' );
  6  exception
  7    when ex_custom
  8    then
  9      dbms_output.put_line( sqlerrm );
 10* end;
SQL> /
ORA-20001: This is a custom error

PL/SQL procedure successfully completed.

Java Runtime.getRuntime(): getting output from executing a command line program

Pretty much the same as other snippets on this page but just organizing things up over an function, here we go...

String str=shell_exec("ls -l");

The Class function:

public String shell_exec(String cmd)
       {
       String o=null;
       try
         {
         Process p=Runtime.getRuntime().exec(cmd);
         BufferedReader b=new BufferedReader(new InputStreamReader(p.getInputStream()));
         String r;
         while((r=b.readLine())!=null)o+=r;
         }catch(Exception e){o="error";}
       return o;
       }

Java Programming: call an exe from Java and passing parameters

import java.io.IOException;
import java.lang.ProcessBuilder;

public class handlingexe {
    public static void main(String[] args) throws IOException {
        ProcessBuilder p = new ProcessBuilder();
        System.out.println("Started EXE");
        p.command("C:\\Users\\AppData\\Local\\Google\\Chrome\\Application\\chrome.exe");   

        p.start();
        System.out.println("Started EXE"); 
    }
}

Getting the parameters of a running JVM

If you are interested in getting the JVM parameters of a running java process, then just do kill -3 java-pid. You will get a core dump file in which you can find the jvm parameters used while launching the java application.

Create an Android GPS tracking application

The source code for the Android mobile application open-gpstracker which you appreciated is available here.

You can checkout the code using SVN client application or via Git:

Debugging the source code will surely help you.

How to use S_ISREG() and S_ISDIR() POSIX Macros?

You're using S_ISREG() and S_ISDIR() correctly, you're just using them on the wrong thing.

In your while((dit = readdir(dip)) != NULL) loop in main, you're calling stat on currentPath over and over again without changing currentPath:

if(stat(currentPath, &statbuf) == -1) {
    perror("stat");
    return errno;
}

Shouldn't you be appending a slash and dit->d_name to currentPath to get the full path to the file that you want to stat? Methinks that similar changes to your other stat calls are also needed.

How can jQuery deferred be used?

You can also integrate it with any 3rd-party libraries which makes use of JQuery.

One such library is Backbone, which is actually going to support Deferred in their next version.

symbol(s) not found for architecture i386

Another situation that can cause this problem is if your code calls into C++, or is called by C++ code. I had a problem with my own .c file's utility function showing up as "symbol not found" when called from Obj-C. The fix was to change the file type: in Xcode 4, use the extended info pane to set the file type to "Objective-C++ Source"; in Xcode 3, use "Get Info" to change file type to "source.cpp.objcpp".

Strange Jackson exception being thrown when serializing Hibernate object

I am New to Jackson API, when i got the "org.codehaus.jackson.map.JsonMappingException: No serializer found for class com.company.project.yourclass" , I added the getter and setter to com.company.project.yourclass, that helped me to use the ObjectMapper's mapper object to write the java object into a flat file.

Example: Communication between Activity and Service using Messaging

Note: You don't need to check if your service is running, CheckIfServiceIsRunning(), because bindService() will start it if it isn't running.

Also: if you rotate the phone you don't want it to bindService() again, because onCreate() will be called again. Be sure to define onConfigurationChanged() to prevent this.

How to implement a ConfigurationSection with a ConfigurationElementCollection

This is generic code for configuration collection :

public class GenericConfigurationElementCollection<T> :   ConfigurationElementCollection, IEnumerable<T> where T : ConfigurationElement, new()
{
    List<T> _elements = new List<T>();

    protected override ConfigurationElement CreateNewElement()
    {
        T newElement = new T();
        _elements.Add(newElement);
        return newElement;
    }

    protected override object GetElementKey(ConfigurationElement element)
    {
        return _elements.Find(e => e.Equals(element));
    }

    public new IEnumerator<T> GetEnumerator()
    {
        return _elements.GetEnumerator();
    }
}

After you have GenericConfigurationElementCollection, you can simple use it in the config section (this is an example from my Dispatcher):

public class  DispatcherConfigurationSection: ConfigurationSection
{
    [ConfigurationProperty("maxRetry", IsRequired = false, DefaultValue = 5)]
    public int MaxRetry
    {
        get
        {
            return (int)this["maxRetry"];
        }
        set
        {
            this["maxRetry"] = value;
        }
    }

    [ConfigurationProperty("eventsDispatches", IsRequired = true)]
    [ConfigurationCollection(typeof(EventsDispatchConfigurationElement), AddItemName = "add", ClearItemsName = "clear", RemoveItemName = "remove")]
    public GenericConfigurationElementCollection<EventsDispatchConfigurationElement> EventsDispatches
    {
        get { return (GenericConfigurationElementCollection<EventsDispatchConfigurationElement>)this["eventsDispatches"]; }
    }
}

The Config Element is config Here:

public class EventsDispatchConfigurationElement : ConfigurationElement
{
    [ConfigurationProperty("name", IsRequired = true)]
    public string Name
    {
        get
        {
            return (string) this["name"];
        }
        set
        {
            this["name"] = value;
        }
    }
}

The config file would look like this:

<?xml version="1.0" encoding="utf-8" ?>
  <dispatcherConfigurationSection>
    <eventsDispatches>
      <add name="Log" ></add>
      <add name="Notification" ></add>
      <add name="tester" ></add>
    </eventsDispatches>
  </dispatcherConfigurationSection>

Hope it help !

Convert array into csv

function array_2_csv($array) {
    $csv = array();
    foreach ($array as $item) {
        if (is_array($item)) {
            $csv[] = array_2_csv($item);
        } else {
            $csv[] = $item;
        }
    }
    return implode(',', $csv);
} 

$csv_data = array_2_csv($array);

echo "<pre>";
print_r($csv_data);
echo '</pre>'   ; 

Is it a bad practice to use break in a for loop?

I agree with others who recommend using break. The obvious consequential question is why would anyone recommend otherwise? Well... when you use break, you skip the rest of the code in the block, and the remaining iterations. Sometimes this causes bugs, for example:

  • a resource acquired at the top of the block may be released at the bottom (this is true even for blocks inside for loops), but that release step may be accidentally skipped when a "premature" exit is caused by a break statement (in "modern" C++, "RAII" is used to handle this in a reliable and exception-safe way: basically, object destructors free resources reliably no matter how a scope is exited)

  • someone may change the conditional test in the for statement without noticing that there are other delocalised exit conditions

  • ndim's answer observes that some people may avoid breaks to maintain a relatively consistent loop run-time, but you were comparing break against use of a boolean early-exit control variable where that doesn't hold

Every now and then people observing such bugs realise they can be prevented/mitigated by this "no breaks" rule... indeed, there's a whole related strategy for "safer" programming called "structured programming", where each function is supposed to have a single entry and exit point too (i.e. no goto, no early return). It may eliminate some bugs, but it doubtless introduces others. Why do they do it?

  • they have a development framework that encourages a particular style of programming / code, and they've statistical evidence that this produces a net benefit in that limited framework, or
  • they've been influenced by programming guidelines or experience within such a framework, or
  • they're just dictatorial idiots, or
  • any of the above + historical inertia (relevant in that the justifications are more applicable to C than modern C++).

How to Ping External IP from Java Android

Use this Code: this method works on 4.3+ and also for below versions too.

   try {

         Process process = null;

        if(Build.VERSION.SDK_INT <= 16) {
            // shiny APIS 
               process = Runtime.getRuntime().exec(
                    "/system/bin/ping -w 1 -c 1 " + url);


        } 
        else 
        {

                   process = new ProcessBuilder()
                 .command("/system/bin/ping", url)
                 .redirectErrorStream(true)
                 .start();

            }



        BufferedReader reader = new BufferedReader(new InputStreamReader(
                process.getInputStream()));

        StringBuffer output = new StringBuffer();
        String temp;

        while ( (temp = reader.readLine()) != null)//.read(buffer)) > 0)
        {
            output.append(temp);
            count++;
        }

        reader.close();


        if(count > 0)
            str = output.toString();

        process.destroy();
     } catch (IOException e) {
         e.printStackTrace();
    }

    Log.i("PING Count", ""+count);
    Log.i("PING String", str);

How to ignore user's time zone and force Date() use specific time zone

To account for milliseconds and the user's time zone, use the following:

var _userOffset = _date.getTimezoneOffset()*60*1000; // user's offset time
var _centralOffset = 6*60*60*1000; // 6 for central time - use whatever you need
_date = new Date(_date.getTime() - _userOffset + _centralOffset); // redefine variable

Make the current Git branch a master branch

One can also checkout all files from the other branch into master:

git checkout master
git checkout better_branch -- .

and then commit all changes.

Python: Figure out local timezone

I was asking the same to myself, and I found the answer in 1:

Take a look at section 8.1.7: the format "%z" (lowercase, the Z uppercase returns also the time zone, but not in the 4-digit format, but in the form of timezone abbreviations, like in [3]) of strftime returns the form "+/- 4DIGIT" that is standard in email headers (see section 3.3 of RFC 2822, see [2], which obsoletes the other ways of specifying the timezone for email headers).

So, if you want your timezone in this format, use:

time.strftime("%z")

[1] http://docs.python.org/2/library/datetime.html

[2] http://tools.ietf.org/html/rfc2822#section-3.3

[3] Timezone abbreviations: http://en.wikipedia.org/wiki/List_of_time_zone_abbreviations , only for reference.

The breakpoint will not currently be hit. No symbols have been loaded for this document in a Silverlight application

I had the same problem - lost lot's of time trying to get debugging working in Visual Studio.

It ended up being Nuget - I had 3 versions of Newtonsoft.Json (across 7 C# projects). The solution would compile but wasn't debuggable.

I fixed the issue by running the following in Nuget's Package Manager Console:

PM> Update-Package Newtonsoft.Json

How to asynchronously call a method in Java

I just discovered that there is a cleaner way to do your

new Thread(new Runnable() {
    public void run() {
        //Do whatever
    }
}).start();

(At least in Java 8), you can use a lambda expression to shorten it to:

new Thread(() -> {
    //Do whatever
}).start();

As simple as making a function in JS!

How to remove elements from a generic list while iterating over it?

A simple and straightforward solution:

Use a standard for-loop running backwards on your collection and RemoveAt(i) to remove elements.

How to check internet access on Android? InetAddress never times out

Following is the code from my Utils class:

public static boolean isNetworkAvailable(Context context) {
        ConnectivityManager connectivityManager 
              = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
        return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}

ObservableCollection not noticing when Item in it changes (even with INotifyPropertyChanged)

Instead of an ObservableCollection or TrulyObservableCollection, consider using a BindingList and calling the ResetBindings method.

For example:

private BindingList<TfsFile> _tfsFiles;

public BindingList<TfsFile> TfsFiles
{
    get { return _tfsFiles; }
    set
    {
        _tfsFiles = value;
        NotifyPropertyChanged();
    }
}

Given an event, such as a click your code would look like this:

foreach (var file in TfsFiles)
{
    SelectedFile = file;
    file.Name = "Different Text";
    TfsFiles.ResetBindings();
}

My model looked like this:

namespace Models
{
    public class TfsFile 
    {
        public string ImagePath { get; set; }

        public string FullPath { get; set; }

        public string Name { get; set; }

        public string Text { get; set; }

    }
}

Sequence contains more than one element

Use FirstOrDefault insted of SingleOrDefault..

SingleOrDefault returns a SINGLE element or null if no element is found. If 2 elements are found in your Enumerable then it throws the exception you are seeing

FirstOrDefault returns the FIRST element it finds or null if no element is found. so if there are 2 elements that match your predicate the second one is ignored

   public int GetPackage(int id,int emp)
           {
             int getpackages=Convert.ToInt32(EmployerSubscriptionPackage.GetAllData().Where(x
   => x.SubscriptionPackageID ==`enter code here` id && x.EmployerID==emp ).FirstOrDefault().ID);
               return getpackages;
           }

 1. var EmployerId = Convert.ToInt32(Session["EmployerId"]);
               var getpackage = GetPackage(employerSubscription.ID, EmployerId);

How to bind inverse boolean properties in WPF?

Don't know if this is relevant to XAML, but in my simple Windows app I created the binding manually and added a Format event handler.

public FormMain() {
  InitializeComponent();

  Binding argBinding = new Binding("Enabled", uxCheckBoxArgsNull, "Checked", false, DataSourceUpdateMode.OnPropertyChanged);
  argBinding.Format += new ConvertEventHandler(Binding_Format_BooleanInverse);
  uxTextBoxArgs.DataBindings.Add(argBinding);
}

void Binding_Format_BooleanInverse(object sender, ConvertEventArgs e) {
  bool boolValue = (bool)e.Value;
  e.Value = !boolValue;
}

How do I resolve "HTTP Error 500.19 - Internal Server Error" on IIS7.0

As I got the 500.19, I gave IIS_IUSRS full access rights for the mentioned web.config and for the folder of the project. This solved the issue.

You can give permissions by

  1. right click on the folder / file
  2. selecting the tab "security"
  3. add the user IIS_IUSRS - don't forget the i in front of USRS and don't write an "e" as in USERS

Does Django scale?

Spreading the tasks evenly, in short optimizing each and every aspect including DBs, Files, Images, CSS etc. and balancing the load with several other resources is necessary once your site/application starts growing. OR you make some more space for it to grow. Implementation of latest technologies like CDN, Cloud are must with huge sites. Just developing and tweaking an application won't give your the cent percent satisfation, other components also play an important role.

How do I solve this error, "error while trying to deserialize parameter"

Make sure that the table you are returning has a schema. If not, then create a default schema (i.e. add a column in that table).

How to compare only Date without Time in DateTime types in Linq to SQL with Entity Framework?

This is how I do this in order to work with LINQ.

DateTime date_time_to_compare = DateTime.Now;
//Compare only date parts
context.YourObject.FirstOrDefault(r =>
                EntityFunctions.TruncateTime(r.date) == EntityFunctions.TruncateTime(date_to_compare));

If you only use dtOne.Date == dtTwo.Date it wont work with LINQ (Error: The specified type member 'Date' is not supported in LINQ to Entities)

How to Consume WCF Service with Android

You will need something more that a http request to interact with a WCF service UNLESS your WCF service has a REST interface. Either look for a SOAP web service API that runs on android or make your service RESTful. You will need .NET 3.5 SP1 to do WCF REST services:

http://msdn.microsoft.com/en-us/netframework/dd547388.aspx

Fastest way to determine if an integer's square root is an integer

If you want speed, given that your integers are of finite size, I suspect that the quickest way would involve (a) partitioning the parameters by size (e.g. into categories by largest bit set), then checking the value against an array of perfect squares within that range.

How to make a Java thread wait for another thread's output?

Try CountDownLatch class out of the java.util.concurrent package, which provides higher level synchronization mechanisms, that are far less error prone than any of the low level stuff.

What does 'IISReset' do?

Editing the web.config file or updating a DLL in the bin folder just recycles the worker process for that application, not the whole pool.

How to create a stopwatch using JavaScript?

Two native solutions

  • performance.now --> Call to ... took 6.414999981643632 milliseconds.
  • console.time --> Call to ... took 5.815 milliseconds

The difference between both is precision.

For usage and explanation read on.



Performance.now (For microsecond precision use)

_x000D_
_x000D_
    var t0 = performance.now();
    doSomething();
    var t1 = performance.now();

    console.log("Call to doSomething took " + (t1 - t0) + " milliseconds.");
            
    function doSomething(){    
       for(i=0;i<1000000;i++){var x = i*i;}
    }
_x000D_
_x000D_
_x000D_

performance.now

Unlike other timing data available to JavaScript (for example Date.now), the timestamps returned by Performance.now() are not limited to one-millisecond resolution. Instead, they represent times as floating-point numbers with up to microsecond precision.

Also unlike Date.now(), the values returned by Performance.now() always increase at a constant rate, independent of the system clock (which might be adjusted manually or skewed by software like NTP). Otherwise, performance.timing.navigationStart + performance.now() will be approximately equal to Date.now().



console.time

Example: (timeEnd wrapped in setTimeout for simulation)

_x000D_
_x000D_
console.time('Search page');
  doSomething();
console.timeEnd('Search page');
 

 function doSomething(){    
       for(i=0;i<1000000;i++){var x = i*i;}
 }
_x000D_
_x000D_
_x000D_

You can change the Timer-Name for different operations.

Creating a selector from a method name with parameters

You can't pass a parameter in a @selector().

It looks like you're trying to implement a callback. The best way to do that would be something like this:

[object setCallbackObject:self withSelector:@selector(myMethod:)];

Then in your object's setCallbackObject:withSelector: method: you can call your callback method.

-(void)setCallbackObject:(id)anObject withSelector:(SEL)selector {
    [anObject performSelector:selector];
}

How do I add a project as a dependency of another project?

Assuming the MyEjbProject is not another Maven Project you own or want to build with maven, you could use system dependencies to link to the existing jar file of the project like so

<project>
   ...
   <dependencies>
      <dependency>
         <groupId>yourgroup</groupId>
         <artifactId>myejbproject</artifactId>
         <version>2.0</version>
         <scope>system</scope>
         <systemPath>path/to/myejbproject.jar</systemPath>
      </dependency>
   </dependencies>
   ...
</project>

That said it is usually the better (and preferred way) to install the package to the repository either by making it a maven project and building it or installing it the way you already seem to do.


If they are, however, dependent on each other, you can always create a separate parent project (has to be a "pom" project) declaring the two other projects as its "modules". (The child projects would not have to declare the third project as their parent). As a consequence you'd get a new directory for the new parent project, where you'd also quite probably put the two independent projects like this:

parent
|- pom.xml
|- MyEJBProject
|   `- pom.xml
`- MyWarProject
    `- pom.xml

The parent project would get a "modules" section to name all the child modules. The aggregator would then use the dependencies in the child modules to actually find out the order in which the projects are to be built)

<project>
   ...
   <artifactId>myparentproject</artifactId>
   <groupId>...</groupId>
   <version>...</version>

   <packaging>pom</packaging>
   ...
   <modules>
     <module>MyEJBModule</module>
     <module>MyWarModule</module>
   </modules>
   ...
</project>

That way the projects can relate to each other but (once they are installed in the local repository) still be used independently as artifacts in other projects


Finally, if your projects are not in related directories, you might try to give them as relative modules:

filesystem
 |- mywarproject
 |   `pom.xml
 |- myejbproject
 |   `pom.xml
 `- parent
     `pom.xml

now you could just do this (worked in maven 2, just tried it):

<!--parent-->
<project>
  <modules>
    <module>../mywarproject</module>
    <module>../myejbproject</module>
  </modules>
</project>

What is an undefined reference/unresolved external symbol error and how do I fix it?

When your include paths are different

Linker errors can happen when a header file and its associated shared library (.lib file) go out of sync. Let me explain.

How do linkers work? The linker matches a function declaration (declared in the header) with its definition (in the shared library) by comparing their signatures. You can get a linker error if the linker doesn't find a function definition that matches perfectly.

Is it possible to still get a linker error even though the declaration and the definition seem to match? Yes! They might look the same in source code, but it really depends on what the compiler sees. Essentially you could end up with a situation like this:

// header1.h
typedef int Number;
void foo(Number);

// header2.h
typedef float Number;
void foo(Number); // this only looks the same lexically

Note how even though both the function declarations look identical in source code, but they are really different according to the compiler.

You might ask how one ends up in a situation like that? Include paths of course! If when compiling the shared library, the include path leads to header1.h and you end up using header2.h in your own program, you'll be left scratching your header wondering what happened (pun intended).

An example of how this can happen in the real world is explained below.

Further elaboration with an example

I have two projects: graphics.lib and main.exe. Both projects depend on common_math.h. Suppose the library exports the following function:

// graphics.lib    
#include "common_math.h" 
   
void draw(vec3 p) { ... } // vec3 comes from common_math.h

And then you go ahead and include the library in your own project.

// main.exe
#include "other/common_math.h"
#include "graphics.h"

int main() {
    draw(...);
}

Boom! You get a linker error and you have no idea why it's failing. The reason is that the common library uses different versions of the same include common_math.h (I have made it obvious here in the example by including a different path, but it might not always be so obvious. Maybe the include path is different in the compiler settings).

Note in this example, the linker would tell you it couldn't find draw(), when in reality you know it obviously is being exported by the library. You could spend hours scratching your head wondering what went wrong. The thing is, the linker sees a different signature because the parameter types are slightly different. In the example, vec3 is a different type in both projects as far as the compiler is concerned. This could happen because they come from two slightly different include files (maybe the include files come from two different versions of the library).

Debugging the linker

DUMPBIN is your friend, if you are using Visual Studio. I'm sure other compilers have other similar tools.

The process goes like this:

  1. Note the weird mangled name given in the linker error. (eg. draw@graphics@XYZ).
  2. Dump the exported symbols from the library into a text file.
  3. Search for the exported symbol of interest, and notice that the mangled name is different.
  4. Pay attention to why the mangled names ended up different. You would be able to see that the parameter types are different, even though they look the same in the source code.
  5. Reason why they are different. In the example given above, they are different because of different include files.

[1] By project I mean a set of source files that are linked together to produce either a library or an executable.

EDIT 1: Rewrote first section to be easier to understand. Please comment below to let me know if something else needs to be fixed. Thanks!

How to pretty-print a numpy.array without scientific notation and with given precision?

The gem that makes it all too easy to obtain the result as a string (in today's numpy versions) is hidden in denis answer: np.array2string

>>> import numpy as np
>>> x=np.random.random(10)
>>> np.array2string(x, formatter={'float_kind':'{0:.3f}'.format})
'[0.599 0.847 0.513 0.155 0.844 0.753 0.920 0.797 0.427 0.420]'

Remove the last three characters from a string

string test = "abcdxxx";
test = test.Remove(test.Length - 3);
//output : abcd

How to get Client location using Google Maps API v3?

Try this :)

    <script type="text/javascript" src="http://www.google.com/jsapi"></script>
    <script type="text/javascript">
    function initialize() {
        var loc = {};
        var geocoder = new google.maps.Geocoder();
        if(google.loader.ClientLocation) {
            loc.lat = google.loader.ClientLocation.latitude;
            loc.lng = google.loader.ClientLocation.longitude;

            var latlng = new google.maps.LatLng(loc.lat, loc.lng);
            geocoder.geocode({'latLng': latlng}, function(results, status) {
                if(status == google.maps.GeocoderStatus.OK) {
                    alert(results[0]['formatted_address']);
                };
            });
        }
    }

    google.load("maps", "3.x", {other_params: "sensor=false", callback:initialize});

    </script>

Default value for field in Django model

You can also use a callable in the default field, such as:

b = models.CharField(max_length=7, default=foo)

And then define the callable:

def foo():
    return 'bar'

Create html documentation for C# code

In 2017, the thing closest to Javadoc would probably DocFx which was developed by Microsoft and comes as a Commmand-Line-Tool as well as a VS2017 plugin.

It's still a little rough around the edges but it looks promising.

Another alternative would be Wyam which has a documentation recipe suitable for net aplications. Look at the cake documentation for an example.

Access-Control-Allow-Origin wildcard subdomains, ports and protocols

I had to modify Lars' answer a bit, as an orphaned \ ended up in the regex, to only compare the actual host (not paying attention to the protocol or port) and I wanted to support localhost domain besides my production domain. Thus I changed the $allowed parameter to be an array.

function getCORSHeaderOrigin($allowed, $input)
{
    if ($allowed == '*') {
        return '*';
    }

    if (!is_array($allowed)) {
        $allowed = array($allowed);
    }

    foreach ($allowed as &$value) {
        $value = preg_quote($value, '/');

        if (($wildcardPos = strpos($value, '\*')) !== false) {
            $value = str_replace('\*', '(.*)', $value);
        }
    }

    $regexp = '/^(' . implode('|', $allowed) . ')$/';

    $inputHost = parse_url($input, PHP_URL_HOST);

    if ($inputHost === null || !preg_match($regexp, $inputHost, $matches)) {
        return 'none';
    }

    return $input;
}

Usage as follows:

if (isset($_SERVER['HTTP_ORIGIN'])) {
    header("Access-Control-Allow-Origin: " . getCORSHeaderOrigin(array("*.myproduction.com", "localhost"), $_SERVER['HTTP_ORIGIN']));
}

How to make a machine trust a self-signed Java application

Just Go To *Startmenu >>Java >>Configure Java >> Security >> Edit site list >> copy and paste your Link with problem >> OK Problem fixed :)*

How do you count the elements of an array in java

If you wish to have an Array in which you will not be allocating all of the elements, you will have to do your own bookkeeping to ensure how many elements you have placed in it via some other variable. If you'd like to avoid doing this while also getting an "Array" that can grow capacities after its initial instantiation, you can create an ArrayList

ArrayList<Integer> theArray = new ArrayList<Integer>();
theArray.add(5); // places at index 0
theArray.size(); // returns length of 1
int answer = theArray.get(0); // index 0 = 5

Don't forget to import it at the top of the file:

import java.util.ArrayList;

iptables LOG and DROP in one rule

for china GFW:

sudo iptables -I INPUT -s 173.194.0.0/16 -p tcp --tcp-flags RST RST -j DROP
sudo iptables -I INPUT -s 173.194.0.0/16 -p tcp --tcp-flags RST RST -j LOG --log-prefix "drop rst"

sudo iptables -I INPUT -s 64.233.0.0/16 -p tcp --tcp-flags RST RST -j DROP
sudo iptables -I INPUT -s 64.233.0.0/16 -p tcp --tcp-flags RST RST -j LOG --log-prefix "drop rst"

sudo iptables -I INPUT -s 74.125.0.0/16 -p tcp --tcp-flags RST RST -j DROP
sudo iptables -I INPUT -s 74.125.0.0/16 -p tcp --tcp-flags RST RST -j LOG --log-prefix "drop rst"

Prevent linebreak after </div>

use this code for normal div display: inline;

use this code if u use it in table display: inline-table; better than table

What's the difference between __PRETTY_FUNCTION__, __FUNCTION__, __func__?

__func__ is an implicitly declared identifier that expands to a character array variable containing the function name when it is used inside of a function. It was added to C in C99. From C99 §6.4.2.2/1:

The identifier __func__ is implicitly declared by the translator as if, immediately following the opening brace of each function definition, the declaration

static const char __func__[] = "function-name";

appeared, where function-name is the name of the lexically-enclosing function. This name is the unadorned name of the function.

Note that it is not a macro and it has no special meaning during preprocessing.

__func__ was added to C++ in C++11, where it is specified as containing "an implementation-de?ned string" (C++11 §8.4.1[dcl.fct.def.general]/8), which is not quite as useful as the specification in C. (The original proposal to add __func__ to C++ was N1642).

__FUNCTION__ is a pre-standard extension that some C compilers support (including gcc and Visual C++); in general, you should use __func__ where it is supported and only use __FUNCTION__ if you are using a compiler that does not support it (for example, Visual C++, which does not support C99 and does not yet support all of C++0x, does not provide __func__).

__PRETTY_FUNCTION__ is a gcc extension that is mostly the same as __FUNCTION__, except that for C++ functions it contains the "pretty" name of the function including the signature of the function. Visual C++ has a similar (but not quite identical) extension, __FUNCSIG__.

For the nonstandard macros, you will want to consult your compiler's documentation. The Visual C++ extensions are included in the MSDN documentation of the C++ compiler's "Predefined Macros". The gcc documentation extensions are described in the gcc documentation page "Function Names as Strings."

Vertical Align Center in Bootstrap 4

In Bootstrap 4 (beta), use align-middle. Refer to Bootstrap 4 Documentation on Vertical alignment:

Change the alignment of elements with the vertical-alignment utilities. Please note that vertical-align only affects inline, inline-block, inline-table, and table cell elements.

Choose from .align-baseline, .align-top, .align-middle, .align-bottom, .align-text-bottom, and .align-text-top as needed.

Flutter - Wrap text on overflow, like insert ellipsis or fade

You can use this code snipped to show text with ellipsis

Text(
    "Introduction to Very very very long text",
    maxLines: 1,
    overflow: TextOverflow.ellipsis,
    softWrap: false,
    style: TextStyle(color: Colors.black, fontWeight: FontWeight.bold),
),

Could not read JSON: Can not deserialize instance of hello.Country[] out of START_OBJECT token

Another solution:

public class CountryInfoResponse {
  private List<Object> geonames;
}

Usage of a generic Object-List solved my problem, as there were other Datatypes like Boolean too.

Android: How do bluetooth UUIDs work?

UUID is similar in notion to port numbers in Internet. However, the difference between Bluetooth and the Internet is that, in Bluetooth, port numbers are assigned dynamically by the SDP (service discovery protocol) server during runtime where each UUID is given a port number. Other devices will ask the SDP server, who is registered under a reserved port number, about the available services on the device and it will reply with different services distinguishable from each other by being registered under different UUIDs.

What are the dark corners of Vim your mom never told you about?

My favourite recipe to switch back and forth between windows:

function! SwitchPrevWin()
    let l:winnr_index = winnr()
    if l:winnr_index > 1
       let l:winnr_index -= 1
    else
       "set winnr_index to max window open
        let l:winnr_index = winnr('$')
    endif
    exe l:winnr_index . "wincmd w" 
endfunction

nmap <M-z> :call SwitchPrevWin()
imap <M-z> <ESC>:call SwitchPrevWin()

nmap <C-z> :wincmd w
imap <C-z> <ESC>:wincmd w

Calendar Recurring/Repeating Events - Best Storage Method

@Rogue Coder

This is great!

You could simply use the modulo operation (MOD or % in mysql) to make your code simple at the end:

Instead of:

AND (
    ( CASE ( 1299132000 - EM1.`meta_value` )
        WHEN 0
          THEN 1
        ELSE ( 1299132000 - EM1.`meta_value` )
      END
    ) / EM2.`meta_value`
) = 1

Do:

$current_timestamp = 1299132000 ;

AND ( ('$current_timestamp' - EM1.`meta_value` ) MOD EM2.`meta_value`) = 1")

To take this further, one could include events that do not recur for ever.

Something like "repeat_interval_1_end" to denote the date of the last "repeat_interval_1" could be added. This however, makes the query more complicated and I can't really figure out how to do this ...

Maybe someone could help!

How to display multiple notifications in android

val notifyIdLong = ((Date().time / 1000L) % Integer.MAX_VALUE)
var notifyIdInteger = notifyIdLong.toInt()
if (notifyIdInteger < 0) notifyIdInteger = -1  * notifyIdInteger // if it's -ve change to positive
notificationManager.notify(notifyIdInteger, mBuilder.build())
log.d(TAG,"notifyId = $notifyIdInteger")

Angular + Material - How to refresh a data source (mat-table)

import { Subject } from 'rxjs/Subject';
import { Observable } from 'rxjs/Observable';

export class LanguageComponent implemnts OnInit {
  displayedColumns = ['name', 'native', 'code', 'leavel'];
  user: any;
  private update = new Subject<void>();
  update$ = this.update.asObservable();

  constructor(private authService: AuthService, private dialog: MatDialog) {}

   ngOnInit() {
     this.update$.subscribe(() => { this.refresh()});
   }

   setUpdate() {
     this.update.next();
   }

   add() {
     this.dialog.open(LanguageAddComponent, {
     data: { user: this.user },
   }).afterClosed().subscribe(result => {
     this.setUpdate();
   });
 }

 refresh() {
   this.authService.getAuthenticatedUser().subscribe((res) => {
     this.user = res;
     this.teachDS = new LanguageDataSource(this.user.profile.languages.teach);   
    });
  }
}

Using CSS to affect div style inside iframe

A sort of hack-ish way of doing things is like Eugene said. I ended up following his code and linking to my custom Css for the page. The problem for me was that, With a twitter timeline you have to do some sidestepping of twitter to override their code a smidgen. Now we have a rolling timeline with our css to it, I.E. Larger font, proper line height and making the scrollbar hidden for heights larger than their limits.

var c = document.createElement('link');
setTimeout(frames[0].document.body.appendChild(c),500); // Mileage varies by connection. Bump 500 a bit higher if necessary

How do I force my .NET application to run as administrator?

Another way of doing this, in code only, is to detect if the process is running as admin like in the answer by @NG.. And then open the application again and close the current one.

I use this code when an application only needs admin privileges when run under certain conditions, such as when installing itself as a service. So it doesn't need to run as admin all the time like the other answers force it too.

Note in the below code NeedsToRunAsAdmin is a method that detects if under current conditions admin privileges are required. If this returns false the code will not elevate itself. This is a major advantage of this approach over the others.

Although this code has the advantages stated above, it does need to re-launch itself as a new process which isn't always what you want.

private static void Main(string[] args)
{
    if (NeedsToRunAsAdmin() && !IsRunAsAdmin())
    {
        ProcessStartInfo proc = new ProcessStartInfo();
        proc.UseShellExecute = true;
        proc.WorkingDirectory = Environment.CurrentDirectory;
        proc.FileName = Assembly.GetEntryAssembly().CodeBase;

        foreach (string arg in args)
        {
            proc.Arguments += String.Format("\"{0}\" ", arg);
        }

        proc.Verb = "runas";

        try
        {
            Process.Start(proc);
        }
        catch
        {
            Console.WriteLine("This application requires elevated credentials in order to operate correctly!");
        }
    }
    else
    {
        //Normal program logic...
    }
}

private static bool IsRunAsAdmin()
{
    WindowsIdentity id = WindowsIdentity.GetCurrent();
    WindowsPrincipal principal = new WindowsPrincipal(id);

    return principal.IsInRole(WindowsBuiltInRole.Administrator);
}

SQL Server table creation date query

For SQL Server 2000:

SELECT   su.name,so.name,so.crdate,* 
FROM     sysobjects so JOIN sysusers su
ON       so.uid = su.uid
WHERE    xtype='U'
ORDER BY so.name

How to unzip a file in Powershell?

ForEach Loop processes each ZIP file located within the $filepath variable

    foreach($file in $filepath)
    {
        $zip = $shell.NameSpace($file.FullName)
        foreach($item in $zip.items())
        {
            $shell.Namespace($file.DirectoryName).copyhere($item)
        }
        Remove-Item $file.FullName
    }

Upload files with HTTPWebrequest (multipart/form-data)

For me, the following works (mostly inspirated from all of the following answers), I started from Elad's answer and modify/simplify things to match my need (remove not file form inputs, only one file, ...).

Hope it can helps somebody :)

(PS: I know that exception handling is not implemented and it assumes that it was written inside a class, so I may need some integration effort...)

private void uploadFile()
    {
        Random rand = new Random();
        string boundary = "----boundary" + rand.Next().ToString();
        Stream data_stream;
        byte[] header = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\nContent-Disposition: form-data; name=\"file_path\"; filename=\"" + System.IO.Path.GetFileName(this.file) + "\"\r\nContent-Type: application/octet-stream\r\n\r\n");
        byte[] trailer = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n");

        // Do the request
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(MBF_URL);
        request.UserAgent = "My Toolbox";
        request.Method = "POST";
        request.KeepAlive = true;
        request.ContentType = "multipart/form-data; boundary=" + boundary;
        data_stream = request.GetRequestStream();
        data_stream.Write(header, 0, header.Length);
        byte[] file_bytes = System.IO.File.ReadAllBytes(this.file);
        data_stream.Write(file_bytes, 0, file_bytes.Length);
        data_stream.Write(trailer, 0, trailer.Length);
        data_stream.Close();

        // Read the response
        WebResponse response = request.GetResponse();
        data_stream = response.GetResponseStream();
        StreamReader reader = new StreamReader(data_stream);
        this.url = reader.ReadToEnd();

        if (this.url == "") { this.url = "No response :("; }

        reader.Close();
        data_stream.Close();
        response.Close();
    }

How to get child element by class name?

But be aware that old browsers doesn't support getElementsByClassName.

Then, you can do

function getElementsByClassName(c,el){
    if(typeof el=='string'){el=document.getElementById(el);}
    if(!el){el=document;}
    if(el.getElementsByClassName){return el.getElementsByClassName(c);}
    var arr=[],
        allEls=el.getElementsByTagName('*');
    for(var i=0;i<allEls.length;i++){
        if(allEls[i].className.split(' ').indexOf(c)>-1){arr.push(allEls[i])}
    }
    return arr;
}
getElementsByClassName('4','test')[0];

It seems it works, but be aware that an HTML class

  • Must begin with a letter: A-Z or a-z
  • Can be followed by letters (A-Za-z), digits (0-9), hyphens ("-"), and underscores ("_")

Why Is `Export Default Const` invalid?

You can also do something like this if you want to export default a const/let, instead of

const MyComponent = ({ attr1, attr2 }) => (<p>Now Export On other Line</p>);
export default MyComponent

You can do something like this, which I do not like personally.

let MyComponent;
export default MyComponent = ({ }) => (<p>Now Export On SameLine</p>);

Difference between chr(13) and chr(10)

Chr(10) is the Line Feed character and Chr(13) is the Carriage Return character.

You probably won't notice a difference if you use only one or the other, but you might find yourself in a situation where the output doesn't show properly with only one or the other. So it's safer to include both.


Historically, Line Feed would move down a line but not return to column 1:

This  
    is  
        a  
            test.

Similarly Carriage Return would return to column 1 but not move down a line:

This  
is  
a  
test.

Paste this into a text editor and then choose to "show all characters", and you'll see both characters present at the end of each line. Better safe than sorry.

How to change the color of a SwitchCompat from AppCompat library

My working example of using style and android:theme simultaneously (API >= 21)

<android.support.v7.widget.SwitchCompat
    android:id="@+id/wan_enable_nat_switch"
    style="@style/Switch"
    app:layout_constraintBaseline_toBaselineOf="@id/wan_enable_nat_label"
    app:layout_constraintEnd_toEndOf="parent" />

<style name="Switch">
    <item name="android:layout_width">wrap_content</item>
    <item name="android:layout_height">wrap_content</item>
    <item name="android:paddingEnd">16dp</item>
    <item name="android:focusableInTouchMode">true</item>
    <item name="android:theme">@style/ThemeOverlay.MySwitchCompat</item>
</style>

<style name="ThemeOverlay.MySwitchCompat" parent="">
    <item name="colorControlActivated">@color/colorPrimaryDark</item>
    <item name="colorSwitchThumbNormal">@color/text_outline_not_active</item>
    <item name="android:colorForeground">#42221f1f</item>
</style>

How to make cross domain request

If you're willing to transmit some data and that you don't need to be secured (any public infos) you can use a CORS proxy, it's very easy, you'll not have to change anything in your code or in server side (especially of it's not your server like the Yahoo API or OpenWeather). I've used it to fetch JSON files with an XMLHttpRequest and it worked fine.

SQL is null and = null

It's important to note, that NULL doesn't equal NULL.

NULL is not a value, and therefore cannot be compared to another value.

where x is null checks whether x is a null value.

where x = null is checking whether x equals NULL, which will never be true

String comparison using '==' vs. 'strcmp()'

strcmp() and === are both case sensitive but === is much faster

sample code: http://snipplr.com/view/758/

'Missing recommended icon file - The bundle does not contain an app icon for iPhone / iPod Touch of exactly '120x120' pixels, in .png format'

For any Xamarin.iOS or Xamarin.Forms developers, additionally you will want to check the .csproj file (for the iOS project) and ensure that it contains references to the PNG's and not just the Asset Catalog i.e.

<ItemGroup>
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Contents.json" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-40.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-40%402x.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-40%403x.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-60%402x.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-60%403x.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-72.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-72%402x.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-76.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-76%402x.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-83.5%402x.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-Small-50.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-Small-50%402x.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-Small.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-Small%402x.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon-Small%403x.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\Icon%402x.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\NotificationIcon%402x.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\NotificationIcon%403x.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\NotificationIcon~ipad.png" />
<ImageAsset Include="Resources\Images.xcassets\AppIcon.appiconset\NotificationIcon~ipad%402x.png" />
</ItemGroup>

Padding between ActionBar's home icon and title

this work for me to add padding to the title and for ActionBar icon i have set that programmatically.

 getActionBar().setTitle(Html.fromHtml("<font color='#fffff'>&nbsp;&nbsp;&nbsp;Boat App </font>"));

java Compare two dates

java.util.Date class has before and after method to compare dates.

Date date1 = new Date();
Date date2 = new Date();

if(date1.before(date2)){
    //Do Something
}

if(date1.after(date2)){
    //Do Something else
}

Why does Git say my master branch is "already up to date" even though it is not?

As the other posters say, pull merges changes from upstream into your repository. If you want to replace what is in your repository with what is in upstream, you have several options. Off the cuff, I'd go with

git checkout HEAD^1  # Get off your repo's master.. doesn't matter where you go, so just go back one commit
git branch -d master  # Delete your repo's master branch
git checkout -t upstream/master  # Check out upstream's master into a local tracking branch of the same name

VBA Copy Sheet to End of Workbook (with Hidden Worksheets)

I faced a similar issue while copying a sheet to another workbook. I prefer to avoid using 'activesheet' though as it has caused me issues in the past. Hence I wrote a function to perform this inline with my needs. I add it here for those who arrive via google as I did:

The main issue here is that copying a visible sheet to the last index position results in Excel repositioning the sheet to the end of the visible sheets. Hence copying the sheet to the position after the last visible sheet sorts this issue. Even if you are copying hidden sheets.

Function Copy_WS_to_NewWB(WB As Workbook, WS As Worksheet) As Worksheet
    'Creates a copy of the specified worksheet in the specified workbook
    '   Accomodates the fact that there may be hidden sheets in the workbook
    
    Dim WSInd As Integer: WSInd = 1
    Dim CWS As Worksheet
    
    'Determine the index of the last visible worksheet
    For Each CWS In WB.Worksheets
        If CWS.Visible Then If CWS.Index > WSInd Then WSInd = CWS.Index
    Next CWS
    
    WS.Copy after:=WB.Worksheets(WSInd)
    Set Copy_WS_to_NewWB = WB.Worksheets(WSInd + 1)

End Function

To use this function for the original question (ie in the same workbook) could be done with something like...

Set test = Copy_WS_to_NewWB(Workbooks(1), Workbooks(1).Worksheets(1))
test.name = "test sheet name"

EDIT 04/11/2020 from –user3598756 Adding a slight refactoring of the above code

Function CopySheetToWorkBook(targetWb As Workbook, shToBeCopied As Worksheet, copiedSh As Worksheet) As Boolean
    'Creates a copy of the specified worksheet in the specified workbook
    '   Accomodates the fact that there may be hidden sheets in the workbook

    Dim lastVisibleShIndex As Long
    Dim iSh As Long

    On Error GoTo SafeExit
    
    With targetWb
        'Determine the index of the last visible worksheet
        For iSh = .Sheets.Count To 1 Step -1
            If .Sheets(iSh).Visible Then
                lastVisibleShIndex = iSh
                Exit For
            End If
        Next
    
        shToBeCopied.Copy after:=.Sheets(lastVisibleShIndex)
        Set copiedSh = .Sheets(lastVisibleShIndex + 1)
    End With
    
    CopySheetToWorkBook = True
    Exit Function
    
SafeExit:
    
End Function

other than using different (more descriptive?) variable names, the refactoring manily deals with:

  1. turning the Function type into a `Boolean while including returned (copied) worksheet within function parameters list this, to let the calling Sub hande possible errors, like

     Dim WB as Workbook: Set WB = ThisWorkbook ' as an example
     Dim sh as Worksheet: Set sh = ActiveSheet ' as an example
     Dim copiedSh as Worksheet
     If CopySheetToWorkBook(WB, sh, copiedSh) Then
         ' go on with your copiedSh sheet
     Else
         Msgbox "Error while trying to copy '" & sh.Name & "'" & vbcrlf & err.Description
     End If
    
  2. having the For - Next loop stepping from last sheet index backwards and exiting at first visible sheet occurence, since we're after the "last" visible one

How can I edit a .jar file?

This is a tool to open Java class file binaries, view their internal structure, modify portions of it if required and save the class file back. It also generates readable reports similar to the javap utility. Easy to use Java Swing GUI. The user interface tries to display as much detail as possible and tries to present a structure as close as the actual Java class file structure. At the same time ease of use and class file consistency while doing modifications is also stressed. For example, when a method is deleted, the associated constant pool entry will also be deleted if it is no longer referenced. In built verifier checks changes before saving the file. This tool has been used by people learning Java class file internals. This tool has also been used to do quick modifications in class files when the source code is not available." this is a quote from the website.

http://classeditor.sourceforge.net/

How to change port for jenkins window service when 8080 is being used

If you are running on Redhat, do following

  1. Stop Jenkins
    $sudo service jenkins stop

  2. change port number in /etc/sysconfig/jenkins like i did for port 8081
    JENKINS_PORT="8081"

  3. start Jenkins again
    $sudo service jenkins start

make sure your FW has correct burn rules.

How to import a new font into a project - Angular 5

You need to put the font files in assets folder (may be a fonts sub-folder within assets) and refer to it in the styles:

@font-face {
  font-family: lato;
  src: url(assets/font/Lato.otf) format("opentype");
}

Once done, you can apply this font any where like:

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'lato', 'arial', sans-serif;
}

You can put the @font-face definition in your global styles.css or styles.scss and you would be able to refer to the font anywhere - even in your component specific CSS/SCSS. styles.css or styles.scss is already defined in angular-cli.json. Or, if you want you can create a separate CSS/SCSS file and declare it in angular-cli.json along with the styles.css or styles.scss like:

"styles": [
  "styles.css",
  "fonts.css"
],

Entity Framework (EF) Code First Cascade Delete for One-to-Zero-or-One relationship

This code worked for me

protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Entity<UserDetail>()
            .HasRequired(d => d.User)
            .WithOptional(u => u.UserDetail)
            .WillCascadeOnDelete(true);
    }

The migration code was:

public override void Up()
    {
        AddForeignKey("UserDetail", "UserId", "User", "UserId", cascadeDelete: true);
    }

And it worked fine. When I first used

modelBuilder.Entity<User>()
    .HasOptional(a => a.UserDetail)
    .WithOptionalDependent()
    .WillCascadeOnDelete(true);

The migration code was:

AddForeignKey("User", "UserDetail_UserId", "UserDetail", "UserId", cascadeDelete: true); 

but it does not match any of the two overloads available (in EntityFramework 6)

Android : change button text and background color

add below line in styles.xml

<style name="AppTheme.Gray" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorButtonNormal">@color/colorGray</item>
    </style>

in button, add android:theme="@style/AppTheme.Gray", example:

<Button
            android:theme="@style/AppTheme.Gray"
            android:textColor="@color/colorWhite"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@android:string/cancel"/>

How to change letter spacing in a Textview?

This answer is based on Pedro's answer but adjusted so it also works if text attribute is already set:

package nl.raakict.android.spc.widget;
import android.content.Context;
import android.text.Spannable;
import android.text.SpannableString;
import android.text.style.ScaleXSpan;
import android.util.AttributeSet;
import android.widget.TextView;


public class LetterSpacingTextView extends TextView {
    private float letterSpacing = LetterSpacing.BIGGEST;
    private CharSequence originalText = "";


    public LetterSpacingTextView(Context context) {
        super(context);
    }

    public LetterSpacingTextView(Context context, AttributeSet attrs){
        super(context, attrs);
        originalText = super.getText();
        applyLetterSpacing();
        this.invalidate();
    }

    public LetterSpacingTextView(Context context, AttributeSet attrs, int defStyle){
        super(context, attrs, defStyle);
    }

    public float getLetterSpacing() {
        return letterSpacing;
    }

    public void setLetterSpacing(float letterSpacing) {
        this.letterSpacing = letterSpacing;
        applyLetterSpacing();
    }

    @Override
    public void setText(CharSequence text, BufferType type) {
        originalText = text;
        applyLetterSpacing();
    }

    @Override
    public CharSequence getText() {
        return originalText;
    }

    private void applyLetterSpacing() {
        if (this == null || this.originalText == null) return;
        StringBuilder builder = new StringBuilder();
        for(int i = 0; i < originalText.length(); i++) {
            String c = ""+ originalText.charAt(i);
            builder.append(c.toLowerCase());
            if(i+1 < originalText.length()) {
                builder.append("\u00A0");
            }
        }
        SpannableString finalText = new SpannableString(builder.toString());
        if(builder.toString().length() > 1) {
            for(int i = 1; i < builder.toString().length(); i+=2) {
                finalText.setSpan(new ScaleXSpan((letterSpacing+1)/10), i, i+1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
            }
        }
        super.setText(finalText, BufferType.SPANNABLE);
    }

    public class LetterSpacing {
        public final static float NORMAL = 0;
        public final static float NORMALBIG = (float)0.025;
        public final static float BIG = (float)0.05;
        public final static float BIGGEST = (float)0.2;
    }
}

If you want to use it programatically:

LetterSpacingTextView textView = new LetterSpacingTextView(context);
textView.setSpacing(10); //Or any float. To reset to normal, use 0 or LetterSpacingTextView.Spacing.NORMAL
textView.setText("My text");
//Add the textView in a layout, for instance:
((LinearLayout) findViewById(R.id.myLinearLayout)).addView(textView);

Android - styling seek bar

I would extract drawables and xml from Android source code and change its color to red. Here is example how I completed this for mdpi drawables:

Custom red_scrubber_control.xml (add to res/drawable):

<selector xmlns:android="http://schemas.android.com/apk/res/android">

    <item android:drawable="@drawable/red_scrubber_control_disabled_holo" android:state_enabled="false"/>
    <item android:drawable="@drawable/red_scrubber_control_pressed_holo" android:state_pressed="true"/>
    <item android:drawable="@drawable/red_scrubber_control_focused_holo" android:state_selected="true"/>
    <item android:drawable="@drawable/red_scrubber_control_normal_holo"/>
</selector>

Custom: red_scrubber_progress.xml

<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >

    <item
        android:id="@android:id/background"
        android:drawable="@drawable/red_scrubber_track_holo_light"/>
    <item android:id="@android:id/secondaryProgress">
        <scale
            android:drawable="@drawable/red_scrubber_secondary_holo"
            android:scaleWidth="100%" />
    </item>
    <item android:id="@android:id/progress">
        <scale
            android:drawable="@drawable/red_scrubber_primary_holo"
            android:scaleWidth="100%" />
    </item>

</layer-list>

Then copy required drawables from Android source code, I took from this link

It is good to copy these drawables for each hdpi, mdpi, xhdpi. For example I use only mdpi:

Then using Photoshop change color from blue to red:

red_scrubber_control_disabled_holo.png: red_scrubber_control_disabled_holo

red_scrubber_control_focused_holo.png: red_scrubber_control_focused_holo

red_scrubber_control_normal_holo.png: red_scrubber_control_normal_holo

red_scrubber_control_pressed_holo.png: red_scrubber_control_pressed_holo

red_scrubber_primary_holo.9.png: red_scrubber_primary_holo.9

red_scrubber_secondary_holo.9.png: red_scrubber_secondary_holo.9

red_scrubber_track_holo_light.9.png: red_scrubber_track_holo_light.9

Add SeekBar to layout:

<SeekBar
    android:id="@+id/seekBar1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:progressDrawable="@drawable/red_scrubber_progress"
    android:thumb="@drawable/red_scrubber_control" />

Result:

enter image description here

"undefined" function declared in another file?

I just had the same problem in GoLand (which is Intellij IDEA for Go) and worked out a solution. You need to change the Run kind from File to Package or Directory. You can choose this from a drop-down if you go into Run/Edit Configurations.

Eg: for package ~/go/src/a_package, use a Package path of a_package and a Directory of ~/go/src/a_package and Run kind of Package or Directory.

How to make fixed header table inside scrollable div?

None of the other examples provided worked in my case - e.g. header would not match table body content when scrolling. I found a much simpler and clean way, allowing you to setup the table the normal way, and without too much code.

Example:

_x000D_
_x000D_
.table-wrapper{
  overflow-y: scroll;
  height: 100px;
}

.table-wrapper th{
    position: sticky;
    top: 0;
    background-color: #FFF;
}
_x000D_
<div class="table-wrapper">
    <table>
        <thead>
            <tr>
                <th>Header 1</th>
                <th>Header 2</th>
                <th>Header 3</th>
            </tr>
        </thead>
        <tbody>
            <tr>
                <td>Text</td>
                <td>Text</td>
                <td>Text</td>
            </tr>
            <tr>
                <td>Text</td>
                <td>Text</td>
                <td>Text</td>
            </tr>
            <tr>
                <td>Text</td>
                <td>Text</td>
                <td>Text</td>
            </tr>
            <tr>
                <td>Text</td>
                <td>Text</td>
                <td>Text</td>
            </tr>
            <tr>
                <td>Text</td>
                <td>Text</td>
                <td>Text</td>
            </tr>
            <tr>
                <td>Text</td>
                <td>Text</td>
                <td>Text</td>
            </tr>
            <tr>
                <td>Text</td>
                <td>Text</td>
                <td>Text</td>
            </tr>
        </tbody>
    </table>
</div>
_x000D_
_x000D_
_x000D_

Thanks to https://algoart.fr/articles/css-table-fixed-header

What is the most useful script you've written for everyday life?


For those of us who don't remember where we are on unix, or which SID we are using.
Pop this in your .profile.

<br>function CD
<br>{
<br>   unalias cd
<br>   command cd "$@" && PS1="\${ORACLE_SID}:$(hostname):$PWD> "
<br>   alias cd=CD
<br>}
<br>
alias cd=CD

How to force a checkbox and text on the same line?

It wont break if you wrap each item in a div. Check out my fiddle with the link below. I made the width of the fieldset 125px and made each item 50px wide. You'll see the label and checkbox remain side by side on a new line and don't break.

<fieldset>
<div class="item">
    <input type="checkbox" id="a">
    <label for="a">a</label>
</div>
<div class="item">
   <input type="checkbox" id="b">
<!-- depending on width, a linebreak can occur here. -->
    <label for="b">bgf bh fhg fdg hg dg gfh dfgh</label>
</div>
<div class="item">
    <input type="checkbox" id="c">
    <label for="c">c</label>
</div>
</fieldset>

http://jsfiddle.net/t5dwp7pg/1/

JavaScript Infinitely Looping slideshow with delays?

Perhps this is what you are looking for.

var pos = 0;
window.onload = function start() {
    setTimeout(slide, 3000);
}
function slide() {
   pos -= 600;
   if (pos === -2400)
     pos = 0;
   document.getElementById('container').style.marginLeft= pos + "px";
   setTimeout(slide, 3000);
}

Use nginx to serve static files from subdirectories of a given directory

It should work, however http://nginx.org/en/docs/http/ngx_http_core_module.html#alias says:

When location matches the last part of the directive’s value: it is better to use the root directive instead:

which would yield:

server {
  listen        8080;
  server_name   www.mysite.com mysite.com;
  error_log     /home/www-data/logs/nginx_www.error.log;
  error_page    404    /404.html;

  location /public/doc/ {
    autoindex on;
    root  /home/www-data/mysite;
  } 

  location = /404.html {
    root /home/www-data/mysite/static/html;
  }       
}

How to change Jquery UI Slider handle

If you should need to replace the handle with something else entirely, rather than just restyling it:

You can specify custom handle elements by creating and appending the elements and adding the ui-slider-handle class before initialization.

Working Example

_x000D_
_x000D_
$('.slider').append('<div class="my-handle ui-slider-handle"><svg height="18" width="14"><path d="M13,9 5,1 A 10,10 0, 0, 0, 5,17z"/></svg></div>');_x000D_
_x000D_
$('.slider').slider({_x000D_
  range: "min",_x000D_
  value: 10_x000D_
});
_x000D_
.slider .ui-state-default {_x000D_
  background: none;_x000D_
}_x000D_
.slider.ui-slider .ui-slider-handle {_x000D_
  width: 14px;_x000D_
  height: 18px;_x000D_
  margin-left: -5px;_x000D_
  top: -4px;_x000D_
  border: none;_x000D_
  background: none;_x000D_
}_x000D_
.slider {_x000D_
  height: 10px;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>_x000D_
<script src="https://code.jquery.com/ui/1.9.1/jquery-ui.min.js"></script>_x000D_
<link href="https://code.jquery.com/ui/1.9.2/themes/base/jquery-ui.css" rel="stylesheet" />_x000D_
<div class="slider"></div>
_x000D_
_x000D_
_x000D_

If else embedding inside html

<?php if ($foo) { ?>
    <div class="mydiv">Condition is true</div>
<?php } else { ?>
    <div class="myotherdiv">Condition is false</div>
<?php } ?>

Is there a timeout for idle PostgreSQL connections?

It sounds like you have a connection leak in your application because it fails to close pooled connections. You aren't having issues just with <idle> in transaction sessions, but with too many connections overall.

Killing connections is not the right answer for that, but it's an OK-ish temporary workaround.

Rather than re-starting PostgreSQL to boot all other connections off a PostgreSQL database, see: How do I detach all other users from a postgres database? and How to drop a PostgreSQL database if there are active connections to it? . The latter shows a better query.

For setting timeouts, as @Doon suggested see How to close idle connections in PostgreSQL automatically?, which advises you to use PgBouncer to proxy for PostgreSQL and manage idle connections. This is a very good idea if you have a buggy application that leaks connections anyway; I very strongly recommend configuring PgBouncer.

A TCP keepalive won't do the job here, because the app is still connected and alive, it just shouldn't be.

In PostgreSQL 9.2 and above, you can use the new state_change timestamp column and the state field of pg_stat_activity to implement an idle connection reaper. Have a cron job run something like this:

SELECT pg_terminate_backend(pid)
    FROM pg_stat_activity
    WHERE datname = 'regress'
      AND pid <> pg_backend_pid()
      AND state = 'idle'
      AND state_change < current_timestamp - INTERVAL '5' MINUTE;

In older versions you need to implement complicated schemes that keep track of when the connection went idle. Do not bother; just use pgbouncer.

Sorting a Dictionary in place with respect to keys

You can't sort a Dictionary<TKey, TValue> - it's inherently unordered. (Or rather, the order in which entries are retrieved is implementation-specific. You shouldn't rely on it working the same way between versions, as ordering isn't part of its designed functionality.)

You can use SortedList<TKey, TValue> or SortedDictionary<TKey, TValue>, both of which sort by the key (in a configurable way, if you pass an IEqualityComparer<T> into the constructor) - might those be of use to you?

Pay little attention to the word "list" in the name SortedList - it's still a dictionary in that it maps keys to values. It's implemented using a list internally, effectively - so instead of looking up by hash code, it does a binary search. SortedDictionary is similarly based on binary searches, but via a tree instead of a list.

increase legend font size ggplot2

You can also specify the font size relative to the base_size included in themes such as theme_bw() (where base_size is 11) using the rel() function.

For example:

ggplot(mtcars, aes(disp, mpg, col=as.factor(cyl))) +
  geom_point() +
  theme_bw() +
  theme(legend.text=element_text(size=rel(0.5)))

Inheriting constructors

Constructors are not inherited. They are called implicitly or explicitly by the child constructor.

The compiler creates a default constructor (one with no arguments) and a default copy constructor (one with an argument which is a reference to the same type). But if you want a constructor that will accept an int, you have to define it explicitly.

class A
{
public: 
    explicit A(int x) {}
};

class B: public A
{
public:
    explicit B(int x) : A(x) { }
};

UPDATE: In C++11, constructors can be inherited. See Suma's answer for details.

How to prevent XSS with HTML/PHP?

Use htmlspecialchars on PHP. On HTML try to avoid using:

element.innerHTML = “…”; element.outerHTML = “…”; document.write(…); document.writeln(…);

where var is controlled by the user.

Also obviously try avoiding eval(var), if you have to use any of them then try JS escaping them, HTML escape them and you might have to do some more but for the basics this should be enough.

How can I disable a button on a jQuery UI dialog?

You can also use the not now documented disabled attribute:

$("#element").dialog({
    buttons: [
    {
        text: "Confirm",
        disabled: true,
        id: "my-button-1"
    }, 
    {
        text: "Cancel",
        id: "my-button-2",
        click: function(){            
               $(this).dialog("close");
        }  

    }]
});

To enable after dialog has opened, use:

$("#my-button-1").attr('disabled', false);

JsFiddle: http://jsfiddle.net/xvt96e1p/4/

How do I iterate over an NSArray?

For OS X 10.4.x and previous:

 int i;
 for (i = 0; i < [myArray count]; i++) {
   id myArrayElement = [myArray objectAtIndex:i];
   ...do something useful with myArrayElement
 }

For OS X 10.5.x (or iPhone) and beyond:

for (id myArrayElement in myArray) {
   ...do something useful with myArrayElement
}

How to create a service running a .exe file on Windows 2012 Server?

You can use PowerShell.

New-Service -Name "TestService" -BinaryPathName "C:\WINDOWS\System32\svchost.exe -k netsvcs"

Refer - https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.management/new-service?view=powershell-3.0

Selenium WebDriver: Wait for complex page with JavaScript to load

Using implicit wait works for me.

driver.Manage().Timeouts().ImplicitWait = TimeSpan.FromSeconds(10);

Refer to this answer Selenium c# Webdriver: Wait Until Element is Present

In PANDAS, how to get the index of a known value?

Using the .loc[] accessor:

In [25]: a.loc[a['c1'] == 8].index[0]
Out[25]: 4

Can also use the get_loc() by setting 'c1' as the index. This will not change the original dataframe.

In [17]: a.set_index('c1').index.get_loc(8)
Out[17]: 4

How to get a div to resize its height to fit container?

I had the same issue, I resolved it using some javascript.

<script type="text/javascript">
 var theHeight = $("#PrimaryContent").height() + 100;
 $('#SecondaryContent').height(theHeight);
</script>

Understanding the results of Execute Explain Plan in Oracle SQL Developer

The CBO builds a decision tree, estimating the costs of each possible execution path available per query. The costs are set by the CPU_cost or I/O_cost parameter set on the instance. And the CBO estimates the costs, as best it can with the existing statistics of the tables and indexes that the query will use. You should not tune your query based on cost alone. Cost allows you to understand WHY the optimizer is doing what it does. Without cost you could figure out why the optimizer chose the plan it did. Lower cost does not mean a faster query. There are cases where this is true and there will be cases where this is wrong. Cost is based on your table stats and if they are wrong the cost is going to be wrong.

When tuning your query, you should take a look at the cardinality and the number of rows of each step. Do they make sense? Is the cardinality the optimizer is assuming correct? Is the rows being return reasonable. If the information present is wrong then its very likely the optimizer doesn't have the proper information it needs to make the right decision. This could be due to stale or missing statistics on the table and index as well as cpu-stats. Its best to have stats updated when tuning a query to get the most out of the optimizer. Knowing your schema is also of great help when tuning. Knowing when the optimizer chose a really bad decision and pointing it in the correct path with a small hint can save a load of time.

Django Cookies, how can I set them?

You could manually set the cookie, but depending on your use case (and if you might want to add more types of persistent/session data in future) it might make more sense to use Django's sessions feature. This will let you get and set variables tied internally to the user's session cookie. Cool thing about this is that if you want to store a lot of data tied to a user's session, storing it all in cookies will add a lot of weight to HTTP requests and responses. With sessions the session cookie is all that is sent back and forth (though there is the overhead on Django's end of storing the session data to keep in mind).

ImportError: No module named PytQt5

This probably means that python doesn't know where PyQt5 is located. To check, go into the interactive terminal and type:

import sys
print sys.path

What you probably need to do is add the directory that contains the PyQt5 module to your PYTHONPATH environment variable. If you use bash, here's how:

Type the following into your shell, and add it to the end of the file ~/.bashrc

export PYTHONPATH=/path/to/PyQt5/directory:$PYTHONPATH

where /path/to/PyQt5/directory is the path to the folder where the PyQt5 library is located.

Ruby value of a hash key?

This question seems to be ambiguous.

I'll try with my interpretation of the request.

def do_something(data)
   puts "Found! #{data}"
end

a = { 'x' => 'test', 'y' => 'foo', 'z' => 'bar' }
a.each { |key,value| do_something(value) if key == 'x' }

This will loop over all the key,value pairs and do something only if the key is 'x'.

How do I convert csv file to rdd

I'd recommend reading the header directly from the driver, not through Spark. Two reasons for this: 1) It's a single line. There's no advantage to a distributed approach. 2) We need this line in the driver, not the worker nodes.

It goes something like this:

// Ridiculous amount of code to read one line.
val uri = new java.net.URI(filename)
val conf = sc.hadoopConfiguration
val fs = hadoop.fs.FileSystem.get(uri, conf)
val path = new hadoop.fs.Path(filename)
val stream = fs.open(path)
val source = scala.io.Source.fromInputStream(stream)
val header = source.getLines.head

Now when you make the RDD you can discard the header.

val csvRDD = sc.textFile(filename).filter(_ != header)

Then we can make an RDD from one column, for example:

val idx = header.split(",").indexOf(columnName)
val columnRDD = csvRDD.map(_.split(",")(idx))

How to sort a HashSet?

Use java.util.TreeSet as the actual object. When you iterate over this collection, the values come back in a well-defined order.

If you use java.util.HashSet then the order depends on an internal hash function which is almost certainly not lexicographic (based on content).

CSS-moving text from left to right

I like using the following to prevent things being outside my div elements. It helps with CSS rollovers too.

.marquee{
    overflow:hidden;
}

this will hide anything that moves/is outside of the div which will prevent the browser expanding and causing a scroll bar to appear.

What does string::npos mean in this code?

Value of string::npos is 18446744073709551615. Its a value returned if there is no string found.

Query to display all tablespaces in a database and datafiles

If you want to get a list of all tablespaces used in the current database instance, you can use the DBA_TABLESPACES view as shown in the following SQL script example:

SQL> connect SYSTEM/fyicenter
Connected.

SQL> SELECT TABLESPACE_NAME, STATUS, CONTENTS
  2  FROM USER_TABLESPACES;
TABLESPACE_NAME                STATUS    CONTENTS
------------------------------ --------- ---------
SYSTEM                         ONLINE    PERMANENT
UNDO                           ONLINE    UNDO
SYSAUX                         ONLINE    PERMANENT
TEMP                           ONLINE    TEMPORARY
USERS                          ONLINE    PERMANENT

http://dba.fyicenter.com/faq/oracle/Show-All-Tablespaces-in-Current-Database.html

ggplot geom_text font size control

Here are a few options for changing text / label sizes

library(ggplot2)

# Example data using mtcars

a <- aggregate(mpg ~ vs + am , mtcars, function(i) round(mean(i)))

p <- ggplot(mtcars, aes(factor(vs), y=mpg, fill=factor(am))) + 
            geom_bar(stat="identity",position="dodge") + 
            geom_text(data = a, aes(label = mpg), 
                            position = position_dodge(width=0.9),  size=20)

The size in the geom_text changes the size of the geom_text labels.

p <- p + theme(axis.text = element_text(size = 15)) # changes axis labels

p <- p + theme(axis.title = element_text(size = 25)) # change axis titles

p <- p + theme(text = element_text(size = 10)) # this will change all text size 
                                                             # (except geom_text)


For this And why size of 10 in geom_text() is different from that in theme(text=element_text()) ?

Yes, they are different. I did a quick manual check and they appear to be in the ratio of ~ (14/5) for geom_text sizes to theme sizes.

So a horrible fix for uniform sizes is to scale by this ratio

geom.text.size = 7
theme.size = (14/5) * geom.text.size

ggplot(mtcars, aes(factor(vs), y=mpg, fill=factor(am))) + 
  geom_bar(stat="identity",position="dodge") + 
  geom_text(data = a, aes(label = mpg), 
            position = position_dodge(width=0.9),  size=geom.text.size) + 
  theme(axis.text = element_text(size = theme.size, colour="black")) 

This of course doesn't explain why? and is a pita (and i assume there is a more sensible way to do this)

How to use Typescript with native ES6 Promises

As of TypeScript 2.0 you can include typings for native promises by including the following in your tsconfig.json

"compilerOptions": {
    "lib": ["es5", "es2015.promise"]
}

This will include the promise declarations that comes with TypeScript without having to set the target to ES6.

How to auto-reload files in Node.js?

loaddir is my solution for quick loading of a directory, recursively.

can return

{ 'path/to/file': 'fileContents...' } or { path: { to: { file: 'fileContents'} } }

It has callback which will be called when the file is changed.

It handles situations where files are large enough that watch gets called before they're done writing.

I've been using it in projects for a year or so, and just recently added promises to it.

Help me battle test it!

https://github.com/danschumann/loaddir

Service located in another namespace

It is so simple to do it

if you want to use it as host and want to resolve it

If you are using ambassador to any other API gateway for service located in another namespace it's always suggested to use :

            Use : <service name>
            Use : <service.name>.<namespace name>
            Not : <service.name>.<namespace name>.svc.cluster.local

it will be like : servicename.namespacename.svc.cluster.local

this will send request to a particular service inside the namespace you have mention.

example:

kind: Service
apiVersion: v1
metadata:
  name: service
spec:
  type: ExternalName
  externalName: <servicename>.<namespace>.svc.cluster.local

Here replace the <servicename> and <namespace> with the appropriate value.

In Kubernetes, namespaces are used to create virtual environment but all are connect with each other.

Delete data with foreign key in SQL Server table

Set the FOREIGN_KEY_CHECKS before and after your delete SQL statements.

SET FOREIGN_KEY_CHECKS = 0;
DELETE FROM table WHERE ...
DELETE FROM table WHERE ...
DELETE FROM table WHERE ...
SET FOREIGN_KEY_CHECKS = 1;

Source: https://alvinalexander.com/blog/post/mysql/drop-mysql-tables-in-any-order-foreign-keys.

How to upgrade docker container after its image changed

I would like to add that if you want to do this process automatically (download, stop and restart a new container with the same settings as described by @Yaroslav) you can use WatchTower. A program that auto updates your containers when they are changed https://github.com/v2tec/watchtower

correct configuration for nginx to localhost?

Fundamentally you hadn't declare location which is what nginx uses to bind URL with resources.

 server {
            listen       80;
            server_name  localhost;

            access_log  logs/localhost.access.log  main;

            location / {
                root /var/www/board/public;
                index index.html index.htm index.php;
            }
       }

Python's "in" set operator

Yes it can mean so, or it can be a simple iterator. For example: Example as iterator:

a=set(['1','2','3'])
for x in a:
 print ('This set contains the value ' + x)

Similarly as a check:

a=set('ILovePython')
if 'I' in a:
 print ('There is an "I" in here')

edited: edited to include sets rather than lists and strings

How to read XML response from a URL in java?

do it with the following code:

DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();

    try {
        DocumentBuilder builder = builderFactory.newDocumentBuilder();
        Document doc = builder.parse("/home/codefelix/IdeaProjects/Gradle/src/main/resources/static/Employees.xml");
        NodeList namelist = (NodeList) doc.getElementById("1");

        for (int i = 0; i < namelist.getLength(); i++) {
            Node p = namelist.item(i);

            if (p.getNodeType() == Node.ELEMENT_NODE) {
                Element person = (Element) p;
                NodeList id = (NodeList) person.getElementsByTagName("Employee");
                NodeList nodeList = person.getChildNodes();
                List<EmployeeDto> employeeDtoList=new ArrayList();

                for (int j = 0; j < nodeList.getLength(); j++) {
                    Node n = nodeList.item(j);

                    if (n.getNodeType() == Node.ELEMENT_NODE) {
                        Element naame = (Element) n;
                        System.out.println("Employee" + id + ":" + naame.getTagName() + "=" +naame.getTextContent());
                    }
                }
            }
        }
    } catch (ParserConfigurationException e) {
        e.printStackTrace();
    } catch (SAXException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

}

Check if Internet Connection Exists with jQuery?

You can try by sending XHR Requests a few times, and then if you get errors it means there's a problem with the internet connection.

Edit: I found this JQuery script which is doing what you are asking for, I didn't test it though.

The Eclipse executable launcher was unable to locate its companion launcher jar windows

Run eclipse.exe file as an Administrator. It worked for me

How to sort an associative array by its values in Javascript?

i use $.each of jquery but you can make it with a for loop, an improvement is this:

        //.ArraySort(array)
        /* Sort an array
         */
        ArraySort = function(array, sortFunc){
              var tmp = [];
              var aSorted=[];
              var oSorted={};

              for (var k in array) {
                if (array.hasOwnProperty(k)) 
                    tmp.push({key: k, value:  array[k]});
              }

              tmp.sort(function(o1, o2) {
                    return sortFunc(o1.value, o2.value);
              });                     

              if(Object.prototype.toString.call(array) === '[object Array]'){
                  $.each(tmp, function(index, value){
                      aSorted.push(value.value);
                  });
                  return aSorted;                     
              }

              if(Object.prototype.toString.call(array) === '[object Object]'){
                  $.each(tmp, function(index, value){
                      oSorted[value.key]=value.value;
                  });                     
                  return oSorted;
              }               
     };

So now you can do

    console.log("ArraySort");
    var arr1 = [4,3,6,1,2,8,5,9,9];
    var arr2 = {'a':4, 'b':3, 'c':6, 'd':1, 'e':2, 'f':8, 'g':5, 'h':9};
    var arr3 = {a: 'green', b: 'brown', c: 'blue', d: 'red'};
    var result1 = ArraySort(arr1, function(a,b){return a-b});
    var result2 = ArraySort(arr2, function(a,b){return a-b});
    var result3 = ArraySort(arr3, function(a,b){return a>b});
    console.log(result1);
    console.log(result2);       
    console.log(result3);

Why am I getting "Unable to find manifest signing certificate in the certificate store" in my Excel Addin?

You need to re-add that certificate to your machine or chose another certificate.

To choose another certificate or to recreate one, head over to the Project's properties page, click on Signing tab and either

  • Click on Select from store
  • Click on Select from file
  • Click on Create test certificate

Once either of these is done, you should be able to build it again.

Bootstrap 3 Glyphicons are not working

If you for example want the icon of glyphicon-chevron-left

Try adding class="glyphicon glyphicon-chevron-left"

How do I print my Java object without getting "SomeType@2f92e0f4"?

Background

All Java objects have a toString() method, which is invoked when you try to print the object.

System.out.println(myObject);  // invokes myObject.toString()

This method is defined in the Object class (the superclass of all Java objects). The Object.toString() method returns a fairly ugly looking string, composed of the name of the class, an @ symbol and the hashcode of the object in hexadecimal. The code for this looks like:

// Code of Object.toString()
public String toString() {
    return getClass().getName() + "@" + Integer.toHexString(hashCode());
}

A result such as com.foo.MyType@2f92e0f4 can therefore be explained as:

  • com.foo.MyType - the name of the class, i.e. the class is MyType in the package com.foo.
  • @ - joins the string together
  • 2f92e0f4 the hashcode of the object.

The name of array classes look a little different, which is explained well in the Javadocs for Class.getName(). For instance, [Ljava.lang.String means:

  • [ - an single-dimensional array (as opposed to [[ or [[[ etc.)
  • L - the array contains a class or interface
  • java.lang.String - the type of objects in the array

Customizing the Output

To print something different when you call System.out.println(myObject), you must override the toString() method in your own class. Here's a simple example:

public class Person {

  private String name;
  
  // constructors and other methods omitted
  
  @Override
  public String toString() {
    return name;
  }
}

Now if we print a Person, we see their name rather than com.foo.Person@12345678.

Bear in mind that toString() is just one way for an object to be converted to a string. Typically this output should fully describe your object in a clear and concise manner. A better toString() for our Person class might be:

@Override
public String toString() {
  return getClass().getSimpleName() + "[name=" + name + "]";
}

Which would print, e.g., Person[name=Henry]. That's a really useful piece of data for debugging/testing.

If you want to focus on just one aspect of your object or include a lot of jazzy formatting, you might be better to define a separate method instead, e.g. String toElegantReport() {...}.


Auto-generating the Output

Many IDEs offer support for auto-generating a toString() method, based on the fields in the class. See docs for Eclipse and IntelliJ, for example.

Several popular Java libraries offer this feature as well. Some examples include:


Printing groups of objects

So you've created a nice toString() for your class. What happens if that class is placed into an array or a collection?

Arrays

If you have an array of objects, you can call Arrays.toString() to produce a simple representation of the contents of the array. For instance, consider this array of Person objects:

Person[] people = { new Person("Fred"), new Person("Mike") };
System.out.println(Arrays.toString(people));

// Prints: [Fred, Mike]

Note: this is a call to a static method called toString() in the Arrays class, which is different to what we've been discussing above.

If you have a multi-dimensional array, you can use Arrays.deepToString() to achieve the same sort of output.

Collections

Most collections will produce a pretty output based on calling .toString() on every element.

List<Person> people = new ArrayList<>();
people.add(new Person("Alice"));
people.add(new Person("Bob"));    
System.out.println(people);

// Prints [Alice, Bob]

So you just need to ensure your list elements define a nice toString() as discussed above.

SQL Server 2005 How Create a Unique Constraint?

ALTER TABLE [TableName] ADD CONSTRAINT  [constraintName] UNIQUE ([columns])

How set background drawable programmatically in Android

Try this code:

Drawable thumb = ContextCompat.getDrawable(getActivity(), R.mipmap.cir_32);
mSeekBar.setThumb(thumb);

SQL Server - INNER JOIN WITH DISTINCT

add "distinct" after "select".

select distinct a.FirstName, a.LastName, v.District , v.LastName
from AddTbl a 
inner join ValTbl v  where a.LastName = v.LastName  order by Firstname

How to grep recursively, but only in files with certain extensions?

Some of these answers seemed too syntax-heavy, or they produced issues on my Debian Server. This worked perfectly for me:

grep -r --include=\*.txt 'searchterm' ./

...or case-insensitive version...

grep -r -i --include=\*.txt 'searchterm' ./
  • grep: command

  • -r: recursively

  • -i: ignore-case

  • --include: all *.txt: text files (escape with \ just in case you have a directory with asterisks in the filenames)

  • 'searchterm': What to search

  • ./: Start at current directory.

Source: PHP Revolution: How to Grep files in Linux, but only certain file extensions?

How to index an element of a list object in R

Indexing a list is done using double bracket, i.e. hypo_list[[1]] (e.g. have a look here: http://www.r-tutor.com/r-introduction/list). BTW: read.table does not return a table but a dataframe (see value section in ?read.table). So you will have a list of dataframes, rather than a list of table objects. The principal mechanism is identical for tables and dataframes though.

Note: In R, the index for the first entry is a 1 (not 0 like in some other languages).

Dataframes

l <- list(anscombe, iris)   # put dfs in list
l[[1]]             # returns anscombe dataframe

anscombe[1:2, 2]   # access first two rows and second column of dataset
[1] 10  8

l[[1]][1:2, 2]     # the same but selecting the dataframe from the list first
[1] 10  8

Table objects

tbl1 <- table(sample(1:5, 50, rep=T))
tbl2 <- table(sample(1:5, 50, rep=T))
l <- list(tbl1, tbl2)  # put tables in a list

tbl1[1:2]              # access first two elements of table 1 

Now with the list

l[[1]]                 # access first table from the list

1  2  3  4  5 
9 11 12  9  9 

l[[1]][1:2]            # access first two elements in first table

1  2 
9 11 

Failed to load the JNI shared Library (JDK)

Installing JDK 1.8._91 (mixed mode) is another solution for this!

How to focus on a form input text field on page load using jQuery?

Sure:

<head>
    <script src="jquery-1.3.2.min.js" type="text/javascript"></script>
    <script type="text/javascript">
        $(function() {
            $("#myTextBox").focus();
        });
    </script>
</head>
<body>
    <input type="text" id="myTextBox">
</body>

Create 3D array using Python

If you insist on everything initializing as empty, you need an extra set of brackets on the inside ([[]] instead of [], since this is "a list containing 1 empty list to be duplicated" as opposed to "a list containing nothing to duplicate"):

distance=[[[[]]*n]*n]*n

Error System.Data.OracleClient requires Oracle client software version 8.1.7 or greater when installs setup

It is a security issue, so to fix it simply do the following:

  1. Go to the Oracle Client folder.
  2. Right Click on the folder.
  3. On security Tab, Add "Authenticated Users" and give this account Read & Execute permission.
  4. Apply this security for all folders, Subfolders and Files (IMPORTANT).
  5. Don't Forget to REBOOT your Machine; if you forgot to do this you will still face the same problem unless you restart your machine.

http://blogs.msdn.com/b/fabdulwahab/archive/2011/11/13/system-data-oracleclient-requires-oracle-client-software-version-8-1-7-or-greater.aspx

Why in C++ do we use DWORD rather than unsigned int?

For myself, I would assume unsigned int is platform specific. Integer could be 8 bits, 16 bits, 32 bits or even 64 bits.

DWORD in the other hand, specifies its own size, which is Double Word. Word are 16 bits so DWORD will be known as 32 bit across all platform

Fetch the row which has the Max value for a column

Just tested this and it seems to work on a logging table

select ColumnNames, max(DateColumn) from log  group by ColumnNames order by 1 desc

How to set gradle home while importing existing project in Android studio

In Ubuntu 14.04 after $ sudo apt-get install gradle I've got

$ whereis gradle
gradle: /usr/bin/gradle /usr/bin/X11/gradle /usr/share/gradle /usr/share/man/man1/gradle.1.gz

The path to Gradle was /usr/share/gradle

Wireshark vs Firebug vs Fiddler - pros and cons?

I use both Charles Proxy and Fiddler for my HTTP/HTTPS level debugging.

Pros of Charles Proxy:

  1. Handles HTTPS better (you get a Charles Certificate which you'd put in 'Trusted Authorities' list)
  2. Has more features like Load/Save Session (esp. useful when debugging multiple pages), Mirror a website (useful in caching assets and hence faster debugging), etc.
  3. As mentioned by jburgess, handles AMF.
  4. Displays JSON, XML and other kind of responses in a tree structure, making it easier to read. Displays images in image responses instead of binary data.

Cons of Charles Proxy:

  1. Cost :-)

Access cell value of datatable

public V[] getV(DataTable dtCloned)
{

    V[] objV = new V[dtCloned.Rows.Count];
    MyClasses mc = new MyClasses();
    int i = 0;
    int intError = 0;
    foreach (DataRow dr in dtCloned.Rows)
    {
        try
        {
            V vs = new V();
            vs.R = int.Parse(mc.ReplaceChar(dr["r"].ToString()).Trim());
            vs.S = Int64.Parse(mc.ReplaceChar(dr["s"].ToString()).Trim());
            objV[i] = vs;
            i++;
        }
        catch (Exception ex)
        {
            //
            DataRow row = dtError.NewRow();
            row["r"] = dr["r"].ToString();
            row["s"] = dr["s"].ToString();
            dtError.Rows.Add(row);
            intError++;
        }
    }
    return vs;
}

I keep getting this error for my simple python program: "TypeError: 'float' object cannot be interpreted as an integer"

In:

for i in range(c/10):

You're creating a float as a result - to fix this use the int division operator:

for i in range(c // 10):

How can I draw circle through XML Drawable - Android?

no need for the padding or the corners.

here's a sample:

<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval" >
    <gradient android:startColor="#FFFF0000" android:endColor="#80FF00FF"
        android:angle="270"/>
</shape>

based on :

https://stackoverflow.com/a/10104037/878126

Android Studio is slow (how to speed up)?

Well, one thing that worked for me is using physical android device instead of emulator. As in my PC( i5 and 4GB RAM ) the android studio takes about 700MB of memory and the emulator takes another 700. Thus the whole performance of the computer goes down. Working with a physical device saves the strain from the emulator.

asp.net mvc @Html.CheckBoxFor

If only one checkbox should be checked in the same time use RadioButtonFor instead:

      @Html.RadioButtonFor(model => model.Type,1, new { @checked = "checked" }) fultime
      @Html.RadioButtonFor(model => model.Type,2) party
      @Html.RadioButtonFor(model => model.Type,3) next option...

If one more one could be checked in the same time use excellent extension: CheckBoxListFor:

Hope,it will help

Invalid hook call. Hooks can only be called inside of the body of a function component

Yesterday, I shortened the code (just added <Provider store={store}>) and still got this invalid hook call problem. This made me suddenly realized what mistake I did: I didn't install the react-redux software in that folder.

I had installed this software in the other project folder, so I didn't realize this one also needed it. After installing it, the error is gone.

clear table jquery

Use .remove()

$("#yourtableid tr").remove();

If you want to keep the data for future use even after removing it then you can use .detach()

$("#yourtableid tr").detach();

If the rows are children of the table then you can use child selector instead of descendant selector, like

$("#yourtableid > tr").remove();

How to insert a picture into Excel at a specified cell position with VBA

I tested both @SWa and @Teamothy solution. I did not find the Pictures.Insert Method in the Microsoft Documentations and feared some compatibility issues. So I guess, the older Shapes.AddPicture Method should work on all versions. But it is slow!

On Error Resume Next
'
' first and faster method (in Office 2016)
'
    With ws.Pictures.Insert(Filename:=imageFileName, LinkToFile:=msoTrue, SaveWithDocument:=msoTrue)
        With .ShapeRange
            .LockAspectRatio = msoTrue
            .Width = destRange.Width
            .height = destRange.height '222
        End With
        .Left = destRange.Left
        .Top = destRange.Top
        .Placement = 1
        .PrintObject = True
        .Name = imageName
    End With
'
' second but slower method (in Office 2016)
'

If Err.Number <> 0 Then
    Err.Clear
    Dim myPic As Shape
    Set myPic = ws.Shapes.AddPicture(Filename:=imageFileName, _
            LinkToFile:=msoFalse, SaveWithDocument:=msoTrue, _
            Left:=destRange.Left, Top:=destRange.Top, Width:=-1, height:=destRange.height)

    With myPic.OLEFormat.Object.ShapeRange
        .LockAspectRatio = msoTrue
        .Width = destRange.Width
        .height = destRange.height '222
    End With
End If

Accessing JSON elements

Another alternative way using get method with requests:

import requests
wjdata = requests.get('url').json()
print wjdata.get('data').get('current_condition')[0].get('temp_C')

Could not open a connection to your authentication agent

If you are using Putty, perhaps you need to set the "Connection/SSH/Auth/Allow agent forwarding" option to "true".

enter image description here

Why can't I center with margin: 0 auto?

We can set the width for ul tag then it will align center.

#header ul {
    display: block;
    margin: 0 auto;
    width: 420px;
    max-width: 100%;
}

How to check if a JavaScript variable is NOT undefined?

var lastname = "Hi";

if(typeof lastname !== "undefined")
{
  alert("Hi. Variable is defined.");
} 

iterating and filtering two lists using java 8

If you stream the first list and use a filter based on contains within the second...

list1.stream()
    .filter(item -> !list2.contains(item))

The next question is what code you'll add to the end of this streaming operation to further process the results... over to you.

Also, list.contains is quite slow, so you would be better with sets.

But then if you're using sets, you might find some easier operations to handle this, like removeAll

Set list1 = ...;
Set list2 = ...;
Set target = new Set();
target.addAll(list1);
target.removeAll(list2);

Given we don't know how you're going to use this, it's not really possible to advise which approach to take.

sql query distinct with Row_Number

Use this:

SELECT *, ROW_NUMBER() OVER (ORDER BY id) AS RowNum FROM
    (SELECT DISTINCT id FROM table WHERE fid = 64) Base

and put the "output" of a query as the "input" of another.

Using CTE:

; WITH Base AS (
    SELECT DISTINCT id FROM table WHERE fid = 64
)

SELECT *, ROW_NUMBER() OVER (ORDER BY id) AS RowNum FROM Base

The two queries should be equivalent.

Technically you could

SELECT DISTINCT id, ROW_NUMBER() OVER (PARTITION BY id ORDER BY id) AS RowNum 
    FROM table
    WHERE fid = 64

but if you increase the number of DISTINCT fields, you have to put all these fields in the PARTITION BY, so for example

SELECT DISTINCT id, description,
    ROW_NUMBER() OVER (PARTITION BY id, description ORDER BY id) AS RowNum 
    FROM table
    WHERE fid = 64

I even hope you comprehend that you are going against standard naming conventions here, id should probably be a primary key, so unique by definition, so a DISTINCT would be useless on it, unless you coupled the query with some JOINs/UNION ALL...

How to fetch Java version using single line command in Linux

You can use --version and in that case it's not required to redirect to stdout

java --version | head -1 | cut -f2 -d' '

From java help

-version      print product version to the error stream and exit
--version     print product version to the output stream and exit

Select Pandas rows based on list index

There are many ways of solving this problem, and the ones listed above are the most commonly used ways of achieving the solution. I want to add two more ways, just in case someone is looking for an alternative.

index_list = [1,3]

df.take(pos)

#or

df.query('index in @index_list')

Encoding as Base64 in Java

You need to change the import of your class:

import org.apache.commons.codec.binary.Base64;

And then change your class to use the Base64 class.

Here's some example code:

byte[] encodedBytes = Base64.encodeBase64("Test".getBytes());
System.out.println("encodedBytes " + new String(encodedBytes));
byte[] decodedBytes = Base64.decodeBase64(encodedBytes);
System.out.println("decodedBytes " + new String(decodedBytes));

Then read why you shouldn't use sun.* packages.


Update (2016-12-16)

You can now use java.util.Base64 with Java 8. First, import it as you normally do:

import java.util.Base64;

Then use the Base64 static methods as follows:

byte[] encodedBytes = Base64.getEncoder().encode("Test".getBytes());
System.out.println("encodedBytes " + new String(encodedBytes));
byte[] decodedBytes = Base64.getDecoder().decode(encodedBytes);
System.out.println("decodedBytes " + new String(decodedBytes));

If you directly want to encode string and get the result as encoded string, you can use this:

String encodeBytes = Base64.getEncoder().encodeToString((userName + ":" + password).getBytes());

See Java documentation for Base64 for more.

Inserting Data into Hive Table

What ever data you have inserted into one text file or log file that can put on one path in hdfs and then write a query as follows in hive

  hive>load data inpath<<specify inputpath>> into table <<tablename>>;

EXAMPLE:

hive>create table foo (id int, name string)
row format delimited
fields terminated by '\t' or '|'or ','
stored as text file;
table created..
    DATA INSERTION::
    hive>load data inpath '/home/hive/foodata.log' into table foo;

Should MySQL have its timezone set to UTC?

It seems that it does not matter what timezone is on the server as long as you have the time set right for the current timezone, know the timezone of the datetime columns that you store, and are aware of the issues with daylight savings time.

On the other hand if you have control of the timezones of the servers you work with then you can have everything set to UTC internally and never worry about timezones and DST.

Here are some notes I collected of how to work with timezones as a form of cheatsheet for myself and others which might influence what timezone the person will choose for his/her server and how he/she will store date and time.

MySQL Timezone Cheatsheet

Notes:

  1. Changing the timezone will not change the stored datetime or timestamp, but it will select a different datetime from timestamp columns
  2. Warning! UTC has leap seconds, these look like '2012-06-30 23:59:60' and can be added randomly, with 6 months prior notice, due to the slowing of the earths rotation
  3. GMT confuses seconds, which is why UTC was invented.

  4. Warning! different regional timezones might produce the same datetime value due to daylight savings time

  5. The timestamp column only supports dates 1970-01-01 00:00:01 to 2038-01-19 03:14:07 UTC, due to a limitation.
  6. Internally a MySQL timestamp column is stored as UTC but when selecting a date MySQL will automatically convert it to the current session timezone.

    When storing a date in a timestamp, MySQL will assume that the date is in the current session timezone and convert it to UTC for storage.

  7. MySQL can store partial dates in datetime columns, these look like "2013-00-00 04:00:00"
  8. MySQL stores "0000-00-00 00:00:00" if you set a datetime column as NULL, unless you specifically set the column to allow null when you create it.
  9. Read this

To select a timestamp column in UTC format

no matter what timezone the current MySQL session is in:

SELECT 
CONVERT_TZ(`timestamp_field`, @@session.time_zone, '+00:00') AS `utc_datetime` 
FROM `table_name`

You can also set the sever or global or current session timezone to UTC and then select the timestamp like so:

SELECT `timestamp_field` FROM `table_name`

To select the current datetime in UTC:

SELECT UTC_TIMESTAMP();
SELECT UTC_TIMESTAMP;
SELECT CONVERT_TZ(NOW(), @@session.time_zone, '+00:00');

Example result: 2015-03-24 17:02:41

To select the current datetime in the session timezone

SELECT NOW();
SELECT CURRENT_TIMESTAMP;
SELECT CURRENT_TIMESTAMP();

To select the timezone that was set when the server launched

SELECT @@system_time_zone;

Returns "MSK" or "+04:00" for Moscow time for example, there is (or was) a MySQL bug where if set to a numerical offset it would not adjust the Daylight savings time

To get the current timezone

SELECT TIMEDIFF(NOW(), UTC_TIMESTAMP);

It will return 02:00:00 if your timezone is +2:00.

To get the current UNIX timestamp (in seconds):

SELECT UNIX_TIMESTAMP(NOW());
SELECT UNIX_TIMESTAMP();

To get the timestamp column as a UNIX timestamp

SELECT UNIX_TIMESTAMP(`timestamp`) FROM `table_name`

To get a UTC datetime column as a UNIX timestamp

SELECT UNIX_TIMESTAMP(CONVERT_TZ(`utc_datetime`, '+00:00', @@session.time_zone)) FROM `table_name`

Get a current timezone datetime from a positive UNIX timestamp integer

SELECT FROM_UNIXTIME(`unix_timestamp_int`) FROM `table_name`

Get a UTC datetime from a UNIX timestamp

SELECT CONVERT_TZ(FROM_UNIXTIME(`unix_timestamp_int`), @@session.time_zone, '+00:00') 
FROM `table_name`

Get a current timezone datetime from a negative UNIX timestamp integer

SELECT DATE_ADD('1970-01-01 00:00:00',INTERVAL -957632400 SECOND) 

There are 3 places where the timezone might be set in MySQL:

Note: A timezone can be set in 2 formats:

  1. an offset from UTC: '+00:00', '+10:00' or '-6:00'
  2. as a named time zone: 'Europe/Helsinki', 'US/Eastern', or 'MET'

Named time zones can be used only if the time zone information tables in the mysql database have been created and populated.

in the file "my.cnf"

default_time_zone='+00:00'

or

timezone='UTC'

@@global.time_zone variable

To see what value they are set to

SELECT @@global.time_zone;

To set a value for it use either one:

SET GLOBAL time_zone = '+8:00';
SET GLOBAL time_zone = 'Europe/Helsinki';
SET @@global.time_zone='+00:00';

@@session.time_zone variable

SELECT @@session.time_zone;

To set it use either one:

SET time_zone = 'Europe/Helsinki';
SET time_zone = "+00:00";
SET @@session.time_zone = "+00:00";

both "@@global.time_zone variable" and "@@session.time_zone variable" might return "SYSTEM" which means that they use the timezone set in "my.cnf".

For timezone names to work (even for default-time-zone) you must setup your timezone information tables need to be populated: http://dev.mysql.com/doc/refman/5.1/en/time-zone-support.html

Note: you can not do this as it will return NULL:

SELECT 
CONVERT_TZ(`timestamp_field`, TIMEDIFF(NOW(), UTC_TIMESTAMP), '+00:00') AS `utc_datetime` 
FROM `table_name`

Setup mysql timezone tables

For CONVERT_TZ to work, you need the timezone tables to be populated

SELECT * FROM mysql.`time_zone` ;
SELECT * FROM mysql.`time_zone_leap_second` ;
SELECT * FROM mysql.`time_zone_name` ;
SELECT * FROM mysql.`time_zone_transition` ;
SELECT * FROM mysql.`time_zone_transition_type` ;

If they are empty, then fill them up by running this command

mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root -p mysql

if this command gives you the error "data too long for column 'abbreviation' at row 1", then it might be caused by a NULL character being appended at the end of the timezone abbreviation

the fix being to run this

mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root -p mysql
(if the above gives error "data too long for column 'abbreviation' at row 1")
mysql_tzinfo_to_sql /usr/share/zoneinfo > /tmp/zut.sql

echo "SET SESSION SQL_MODE = '';" > /tmp/mysql_tzinfo_to.sql
cat /tmp/zut.sql >> /tmp/mysql_tzinfo_to.sql

mysql --defaults-file=/etc/mysql/my.cnf --user=verifiedscratch -p mysql < /tmp/mysql_tzinfo_to.sql

(make sure your servers dst rules are up to date zdump -v Europe/Moscow | grep 2011 https://chrisjean.com/updating-daylight-saving-time-on-linux/)

See the full DST (Daylight Saving Time) transition history for every timezone

SELECT 
tzn.Name AS tz_name,
tztt.Abbreviation AS tz_abbr,
tztt.Is_DST AS is_dst,
tztt.`Offset` AS `offset`,
DATE_ADD('1970-01-01 00:00:00',INTERVAL tzt.Transition_time SECOND)  AS transition_date
FROM mysql.`time_zone_transition` tzt
INNER JOIN mysql.`time_zone_transition_type` tztt USING(Time_zone_id, Transition_type_id)
INNER JOIN mysql.`time_zone_name` tzn USING(Time_zone_id)
-- WHERE tzn.Name LIKE 'Europe/Moscow' -- Moscow has weird DST changes
ORDER BY tzt.Transition_time ASC

CONVERT_TZ also applies any necessary DST changes based on the rules in the above tables and the date that you use.

Note:
According to the docs, the value you set for time_zone does not change, if you set it as "+01:00" for example, then the time_zone will be set as an offset from UTC, which does not follow DST, so it will stay the same all year round.

Only the named timezones will change time during daylight savings time.

Abbreviations like CET will always be a winter time and CEST will be summer time while +01:00 will always be UTC time + 1 hour and both won't change with DST.

The system timezone will be the timezone of the host machine where mysql is installed (unless mysql fails to determine it)

You can read more about working with DST here

related questions:

Sources:

How to remove spaces from a string using JavaScript?

var input = '/var/www/site/Brand new document.docx';

//remove space
input = input.replace(/\s/g, '');

//make string lower
input = input.toLowerCase();

alert(input);

Click here for working example

How to my "exe" from PyCharm project

You cannot directly save a Python file as an exe and expect it to work -- the computer cannot automatically understand whatever code you happened to type in a text file. Instead, you need to use another program to transform your Python code into an exe.

I recommend using a program like Pyinstaller. It essentially takes the Python interpreter and bundles it with your script to turn it into a standalone exe that can be run on arbitrary computers that don't have Python installed (typically Windows computers, since Linux tends to come pre-installed with Python).

To install it, you can either download it from the linked website or use the command:

pip install pyinstaller

...from the command line. Then, for the most part, you simply navigate to the folder containing your source code via the command line and run:

pyinstaller myscript.py

You can find more information about how to use Pyinstaller and customize the build process via the documentation.


You don't necessarily have to use Pyinstaller, though. Here's a comparison of different programs that can be used to turn your Python code into an executable.

How do I POST an array of objects with $.ajax (jQuery or Zepto)

Check this example of post the array of different types

function PostArray() {
    var myObj = [
        { 'fstName': 'name 1', 'lastName': 'last name 1', 'age': 32 }
      , { 'fstName': 'name 2', 'lastName': 'last name 1', 'age': 33 }
    ];

    var postData = JSON.stringify({ lst: myObj });
    console.log(postData);

    $.ajax({
        type: "POST",
        url: urlWebMethods + "/getNames",
        data: postData,
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: function (response) {
            alert(response.d);
        },
        failure: function (msg) {
            alert(msg.d);
        }
    });
}

If using a WebMethod in C# you can retrieve the data like this

[WebMethod]
    public static string getNames(IEnumerable<object> lst)
    {
        string names = "";
        try
        {
            foreach (object item in lst)
            {
                Type myType = item.GetType();
                IList<PropertyInfo> props = new List<PropertyInfo>(myType.GetProperties());

                foreach (PropertyInfo prop in props)
                {
                    if(prop.Name == "Values")
                    {
                        Dictionary<string, object> dic = item as Dictionary<string, object>;
                        names += dic["fstName"];
                    }
                }
            }
        }
        catch (Exception ex)
        {
             names = "-1";
        }
        return names;
    }

Example in POST an array of objects with $.ajax to C# WebMethod

How to get current timestamp in milliseconds since 1970 just the way Java gets

This answer is pretty similar to Oz.'s, using <chrono> for C++ -- I didn't grab it from Oz. though...

I picked up the original snippet at the bottom of this page, and slightly modified it to be a complete console app. I love using this lil' ol' thing. It's fantastic if you do a lot of scripting and need a reliable tool in Windows to get the epoch in actual milliseconds without resorting to using VB, or some less modern, less reader-friendly code.

#include <chrono>
#include <iostream>

int main() {
    unsigned __int64 now = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
    std::cout << now << std::endl;
    return 0;
}

Difference between jQuery .hide() and .css("display", "none")

Yes there is a difference.

jQuery('#id').css("display","block") will always set the element you want to show as block.

jQuery('#id').show() will et is to what display type it initially was, display: inline for example.

See Jquery Doc

JSON: why are forward slashes escaped?

PHP escapes forward slashes by default which is probably why this appears so commonly. I'm not sure why, but possibly because embedding the string "</script>" inside a <script> tag is considered unsafe.

This functionality can be disabled by passing in the JSON_UNESCAPED_SLASHES flag but most developers will not use this since the original result is already valid JSON.

MySQL root access from all hosts

if you have many networks attached to you OS, yo must especify one of this network in the bind-addres from my.conf file. an example:

[mysqld]
bind-address = 127.100.10.234

this ip is from a ethX configuration.

jQuery equivalent to Prototype array.last()

url : www.mydomain.com/user1/1234

$.params = window.location.href.split("/"); $.params[$.params.length-1];

You can split based on your query string separator

Comparing Dates in Oracle SQL

Single quote must be there, since date converted to character.

Select employee_id, count(*)
From Employee
Where to_char(employee_date_hired, 'DD-MON-YY') > '31-DEC-95';

Check if a string matches a regex in Bash script

I would use expr match instead of =~:

expr match "$date" "[0-9]\{8\}" >/dev/null && echo yes

This is better than the currently accepted answer of using =~ because =~ will also match empty strings, which IMHO it shouldn't. Suppose badvar is not defined, then [[ "1234" =~ "$badvar" ]]; echo $? gives (incorrectly) 0, while expr match "1234" "$badvar" >/dev/null ; echo $? gives correct result 1.

We have to use >/dev/null to hide expr match's output value, which is the number of characters matched or 0 if no match found. Note its output value is different from its exit status. The exit status is 0 if there's a match found, or 1 otherwise.

Generally, the syntax for expr is:

expr match "$string" "$lead"

Or:

expr "$string" : "$lead"

where $lead is a regular expression. Its exit status will be true (0) if lead matches the leading slice of string (Is there a name for this?). For example expr match "abcdefghi" "abc"exits true, but expr match "abcdefghi" "bcd" exits false. (Credit to @Carlo Wood for pointing out this.

What is the difference between JavaScript and ECMAScript?

What is ECMAScript i.e. ES?

ECMAScript is a standard for a scripting language and the Javascript language is based on the ECMAScript standard.

Is Javascript exactly the same as ECMAScript?

  • No, Javascript is not exactly equivalent to ECMAScript.
  • The core features of Javascript are based on the ECMAScript standard, but Javascript also has other additional features that are not in the ECMA specifications/standard.

JavaScript = ECMAScript + DOM API;

DOM API like: document.getElementById('id');

Do other languages use the ECMAScript standard?

  • Yes, there are languages other than JavaScript that also implement the ECMAScript Standard as their core.
  • ActionScript (used by Adobe Flash) and JScript (used by Microsoft) are both languages that implement the ECMAScript standard.

Why is it called ECMAScript?

  • Javascript was originally created at Netscape, and they wanted to standardize the language. So, they submitted the language to the European Computer Manufacturer’s Association (ECMA) for standardization.
  • But, there were trademark issues with the name Javascript, and the standard became called ECMAScript, which is the name it holds today as well.
  • Because of trademark issues, Microsoft’s version of the language is called JScript – even though JScript is, at its core, the same language as Javascript.

Update Tkinter Label from variable

The window is only displayed once the mainloop is entered. So you won't see any changes you make in your while True block preceding the line root.mainloop().


GUI interfaces work by reacting to events while in the mainloop. Here's an example where the StringVar is also connected to an Entry widget. When you change the text in the Entry widget it automatically changes in the Label.

from tkinter import *

root = Tk()
var = StringVar()
var.set('hello')

l = Label(root, textvariable = var)
l.pack()

t = Entry(root, textvariable = var)
t.pack()

root.mainloop() # the window is now displayed

I like the following reference: tkinter 8.5 reference: a GUI for Python


Here is a working example of what you were trying to do:

from tkinter import *
from time import sleep

root = Tk()
var = StringVar()
var.set('hello')

l = Label(root, textvariable = var)
l.pack()

for i in range(6):
    sleep(1) # Need this to slow the changes down
    var.set('goodbye' if i%2 else 'hello')
    root.update_idletasks()

root.update Enter event loop until all pending events have been processed by Tcl.

Is double square brackets [[ ]] preferable over single square brackets [ ] in Bash?

[[ ]] double brackets are unsuported under certain version of SunOS and totally unsuported inside function declarations by : GNU bash, version 2.02.0(1)-release (sparc-sun-solaris2.6)

How do I copy a version of a single file from one git branch to another?

Following madlep's answer you can also just copy one directory from another branch with the directory blob.

git checkout other-branch app/**

As to the op's question if you've only changed one file in there this will work fine ^_^

How to add element to C++ array?

Initialize all your array elements to null first, then look for the null to find the empty slot

How to wait for 2 seconds?

As mentioned in other answers, all of the following will work for the standard string-based syntax.

WAITFOR DELAY '02:00' --Two hours
WAITFOR DELAY '00:02' --Two minutes
WAITFOR DELAY '00:00:02' --Two seconds
WAITFOR DELAY '00:00:00.200' --Two tenths of a seconds

There is also an alternative method of passing it a DATETIME value. You might think I'm confusing this with WAITFOR TIME, but it also works for WAITFOR DELAY.

Considerations for passing DATETIME:

  • It must be passed as a variable, so it isn't a nice one-liner anymore.
  • The delay is measured as the time since the Epoch ('1900-01-01').
  • For situations that require a variable amount of delay, it is much easier to manipulate a DATETIME than to properly format a VARCHAR.

How to wait for 2 seconds:

--Example 1
DECLARE @Delay1 DATETIME
SELECT @Delay1 = '1900-01-01 00:00:02.000'
WAITFOR DELAY @Delay1

--Example 2
DECLARE @Delay2 DATETIME
SELECT @Delay2 = dateadd(SECOND, 2, convert(DATETIME, 0))
WAITFOR DELAY @Delay2

A note on waiting for TIME vs DELAY:

Have you ever noticed that if you accidentally pass WAITFOR TIME a date that already passed, even by just a second, it will never return? Check it out:

--Example 3
DECLARE @Time1 DATETIME
SELECT @Time1 = getdate()
WAITFOR DELAY '00:00:01'
WAITFOR TIME @Time1 --WILL HANG FOREVER

Unfortunately, WAITFOR DELAY will do the same thing if you pass it a negative DATETIME value (yes, that's a thing).

--Example 4
DECLARE @Delay3 DATETIME
SELECT @Delay3 = dateadd(SECOND, -1, convert(DATETIME, 0))
WAITFOR DELAY @Delay3 --WILL HANG FOREVER

However, I would still recommend using WAITFOR DELAY over a static time because you can always confirm your delay is positive and it will stay that way for however long it takes your code to reach the WAITFOR statement.

How to get the file extension in PHP?

A better method is using strrpos + substr (faster than explode for that) :

$userfile_name = $_FILES['image']['name'];
$userfile_extn = substr($userfile_name, strrpos($userfile_name, '.')+1);

But, to check the type of a file, using mime_content_type is a better way : http://www.php.net/manual/en/function.mime-content-type.php

GoTo Next Iteration in For Loop in java

use continue keyword .

EX:

for(int i = 0; i < 10; i++){
  if(i == 5){
    continue;
   }
}

Import Excel spreadsheet columns into SQL Server database

By 'the wiz' I'm assuming you're talking about the 'SQL Server Import and Export Wizard'. (I'm also pretty new so I don't understand most questions, much less most answers, but I think I get this one). If so couldn't you take the spreadsheet, or a copy of it, delete the columns you don't want imported and then use the wizard?

I've always found the ability to do what I need with it and I'm only on SQL Server 2000 (not sure how other versions differ).

Edit: In fact I'm looking at it now and I seem to be able to choose which columns I want to map to which rows in an existing table. On the 'Select Source Tables and Views' screen I check the datasheet I'm using, select the 'Destination' then click the 'Edit...' button. From there you can choose the Excel column and the table column to map it to.

How to set headers in http get request?

The Header field of the Request is public. You may do this :

req.Header.Set("name", "value")

How to access the contents of a vector from a pointer to the vector in C++?

vector <int> numbers {10,20,30,40};
vector <int> *ptr {nullptr};

ptr = &numbers;

for(auto num: *ptr){
 cout << num << endl;
}


cout << (*ptr).at(2) << endl; // 20

cout << "-------" << endl;

cout << ptr -> at(2) << endl; // 20

TypeScript for ... of with index / key?

Or another old school solution:

var someArray = [9, 2, 5];
let i = 0;
for (var item of someArray) {
    console.log(item); // 9,2,5
    i++;
}

How do I import a .bak file into Microsoft SQL Server 2012?

Not sure why they removed the option to just right click on the database and restore like you could in SQL Server Management Studio 2008 and earlier, but as mentioned above you can restore from a .BAK file with:

RESTORE DATABASE YourDB FROM DISK = 'D:BackUpYourBaackUpFile.bak' WITH REPLACE

But you will want WITH REPLACE instead of WITH RESTORE if your moving it from one server to another.

Python pandas insert list into a cell

Quick work around

Simply enclose the list within a new list, as done for col2 in the data frame below. The reason it works is that python takes the outer list (of lists) and converts it into a column as if it were containing normal scalar items, which is lists in our case and not normal scalars.

mydict={'col1':[1,2,3],'col2':[[1, 4], [2, 5], [3, 6]]}
data=pd.DataFrame(mydict)
data


   col1     col2
0   1       [1, 4]
1   2       [2, 5]
2   3       [3, 6]

'printf' with leading zeros in C

Your format specifier is incorrect. From the printf() man page on my machine:

0 A zero '0' character indicating that zero-padding should be used rather than blank-padding. A '-' overrides a '0' if both are used;

Field Width: An optional digit string specifying a field width; if the output string has fewer characters than the field width it will be blank-padded on the left (or right, if the left-adjustment indicator has been given) to make up the field width (note that a leading zero is a flag, but an embedded zero is part of a field width);

Precision: An optional period, '.', followed by an optional digit string giving a precision which specifies the number of digits to appear after the decimal point, for e and f formats, or the maximum number of characters to be printed from a string; if the digit string is missing, the precision is treated as zero;

For your case, your format would be %09.3f:

#include <stdio.h>

int main(int argc, char **argv)
{
  printf("%09.3f\n", 4917.24);
  return 0;
}

Output:

$ make testapp
cc     testapp.c   -o testapp
$ ./testapp 
04917.240

Note that this answer is conditional on your embedded system having a printf() implementation that is standard-compliant for these details - many embedded environments do not have such an implementation.

Android: how do I check if activity is running?

Have you tried..

    if (getActivity() instanceof NameOfYourActivity){
        //Do something
    }

Android: Color To Int conversion

I think it should be R.color.black

Also take a look at Converting android color string in runtime into int

MongoDB Show all contents from all collections

This way:

db.collection_name.find().toArray().then(...function...)

increment date by one month

 <?php
              $selectdata ="select fromd,tod  from register where username='$username'";
            $q=mysqli_query($conm,$selectdata);
            $row=mysqli_fetch_array($q);

            $startdate=$row['fromd']; 
            $stdate=date('Y', strtotime($startdate));  

            $endate=$row['tod']; 
            $enddate=date('Y', strtotime($endate));  

            $years = range ($stdate,$enddate);
            echo '<select name="years" class="form-control">';
            echo '<option>SELECT</option>';
            foreach($years as $year)
              {   echo '<option value="'.$year.'"> '.$year.' </option>';  }
                echo '</select>'; ?>

Performance differences between ArrayList and LinkedList

Ignore this answer for now. The other answers, particularly that of aix, are mostly correct. Over the long term they're the way to bet. And if you have enough data (on one benchmark on one machine, it seemed to be about one million entries) ArrayList and LinkedList do currently work as advertized. However, there are some fine points that apply in the early 21st century.

Modern computer technology seems, by my testing, to give an enormous edge to arrays. Elements of an array can be shifted and copied at insane speeds. As a result arrays and ArrayList will, in most practical situations, outperform LinkedList on inserts and deletes, often dramatically. In other words, ArrayList will beat LinkedList at its own game.

The downside of ArrayList is it tends to hang onto memory space after deletions, where LinkedList gives up space as it gives up entries.

The bigger downside of arrays and ArrayList is they fragment free memory and overwork the garbage collector. As an ArrayList expands, it creates new, bigger arrays, copies the old array to the new one, and frees the old one. Memory fills with big contiguous chunks of free memory that are not big enough for the next allocation. Eventually there's no suitable space for that allocation. Even though 90% of memory is free, no individual piece is big enough to do the job. The GC will work frantically to move things around, but if it takes too long to rearrange the space, it will throw an OutOfMemoryException. If it doesn't give up, it can still slow your program way down.

The worst of it is this problem can be hard to predict. Your program will run fine one time. Then, with a bit less memory available, with no warning, it slows or stops.

LinkedList uses small, dainty bits of memory and GC's love it. It still runs fine when you're using 99% of your available memory.

So in general, use ArrayList for smaller sets of data that are not likely to have most of their contents deleted, or when you have tight control over creation and growth. (For instance, creating one ArrayList that uses 90% of memory and using it without filling it for the duration of the program is fine. Continually creating and freeing ArrayList instances that use 10% of memory will kill you.) Otherwise, go with LinkedList (or a Map of some sort if you need random access). If you have very large collections (say over 100,000 elements), no concerns about the GC, and plan lots of inserts and deletes and no random access, run a few benchmarks to see what's fastest.

How to pass arguments from command line to gradle

My program with two arguments, args[0] and args[1]:

public static void main(String[] args) throws Exception {
    System.out.println(args);
    String host = args[0];
    System.out.println(host);
    int port = Integer.parseInt(args[1]);

my build.gradle

run {
    if ( project.hasProperty("appArgsWhatEverIWant") ) {
        args Eval.me(appArgsWhatEverIWant)
    }
}

my terminal prompt:

gradle run  -PappArgsWhatEverIWant="['localhost','8080']"

Java, Simplified check if int array contains int

Here is Java 8 solution

public static boolean contains(final int[] arr, final int key) {
    return Arrays.stream(arr).anyMatch(i -> i == key);
}

Best way to check that element is not present using Selenium WebDriver with java

int i=1;

while (true) {
  WebElementdisplay=driver.findElement(By.id("__bar"+i+"-btnGo"));
  System.out.println(display);

  if (display.isDisplayed()==true)
  { 
    System.out.println("inside if statement"+i);
    driver.findElement(By.id("__bar"+i+"-btnGo")).click();
    break;
  }
  else
  {
    System.out.println("inside else statement"+ i);
    i=i+1;
  }
}

Open File Dialog, One Filter for Multiple Excel Extensions?

If you want to merge the filters (eg. CSV and Excel files), use this formula:

OpenFileDialog of = new OpenFileDialog();
of.Filter = "CSV files (*.csv)|*.csv|Excel Files|*.xls;*.xlsx";

Or if you want to see XML or PDF files in one time use this:

of.Filter = @" XML or PDF |*.xml;*.pdf";

How can I view the contents of an ElasticSearch index?

You can even add the size of the terms (indexed terms). Have a look at Elastic Search: how to see the indexed data

Redirect to a page/URL after alert button is pressed

You're missing semi-colons after your javascript lines. Also, window.location should have .href or .replace etc to redirect - See this post for more information.

echo '<script type="text/javascript">'; 
echo 'alert("review your answer");'; 
echo 'window.location.href = "index.php";';
echo '</script>';

For clarity, try leaving PHP tags for this:

?>
<script type="text/javascript">
alert("review your answer");
window.location.href = "index.php";
</script>
<?php

NOTE: semi colons on seperate lines are optional, but encouraged - however as in the comments below, PHP won't break lines in the first example here but will in the second, so semi-colons are required in the first example.

How do I handle a click anywhere in the page, even when a certain element stops the propagation?

this is the key (vs evt.target). See example.

_x000D_
_x000D_
document.body.addEventListener("click", function (evt) {_x000D_
    console.dir(this);_x000D_
    //note evt.target can be a nested element, not the body element, resulting in misfires_x000D_
    console.log(evt.target);_x000D_
    alert("body clicked");_x000D_
});
_x000D_
<h4>This is a heading.</h4>_x000D_
<p>this is a paragraph.</p>
_x000D_
_x000D_
_x000D_

Read each line of txt file to new array element

$lines = array();
while (($line = fgets($file)) !== false)
    array_push($lines, $line);

Obviously, you'll need to create a file handle first and store it in $file.

Does mobile Google Chrome support browser extensions?

You can use bookmarklets (javascript code in a bookmark) - this also means they sync across devices.

I have loads - I prefix the name with zzz, so they are eazy to type in to the address bar and show in drop down predictions.

To get them to operate on a page you need to go to the page and then in the address bar type the bookmarklet name - this will cause the bookmarklet to execute in the context of the page.

edit

Just to highlight - for this to work, the bookmarklet name must be typed into the address bar while the page you want to operate in is being displayed - if you go off to select the bookmarklet in some other way the page context gets lost, and the bookmarklet operates on a new empty page.

I use zzzpocket - send to pocket. zzztwitter tweet this page zzzmail email this page zzzpressthis send this page to wordpress zzztrello send this page to trello and more...

and it works in chrome whatever platform I am currently logged on to.

How to calculate moving average without keeping the count and data-total?

From a blog on running sample variance calculations, where the mean is also calculated using Welford's method:

enter image description here

Too bad we can't upload SVG images.

How to set default value to the input[type="date"]

1 - @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
    <input type="date" "myDate">
    @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

    var today = new Date();
    $('#myDate').val(today.getFullYear() + '-' + ('0' + (today.getMonth() + 1)).slice(-2) + '-' + ('0' + today.getDate()).slice(-2));

2 - @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
   <input type="datatime-local" id="myLocalDataTime" step="1">
    @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

var today = new Date();
$('#myLocalDataTime').val(today.getFullYear() + '-' + ('0' + (today.getMonth() + 1)).slice(-2) + '-' + ('0' + today.getDate()).slice(-2)+'T'+today.getHours()+':'+today.getMinutes());

Share data between html pages

why don't you store your values in HTML5 storage objects such as sessionStorage or localStorage, visit HTML5 Storage Doc to get more details. Using this you can store intermediate values temporarily/permanently locally and then access your values later.

To store values for a session:

sessionStorage.getItem('label')
sessionStorage.setItem('label', 'value')

or more permanently:

localStorage.getItem('label')
localStorage.setItem('label', 'value')

So you can store (temporarily) form data between multiple pages using HTML5 storage objects which you can even retain after reload..

GitHub - failed to connect to github 443 windows/ Failed to connect to gitHub - No Error

If using SSH config file, my issue was that ~/.ssh/config was not specified correct. From Enabling SSH connections over HTTPS

Host github.com
  Hostname ssh.github.com
  Port 443

How to present UIAlertController when not in a view controller?

Register for a notification prior to calling the class method.

Swift code:

NSNotificationCenter.defaultCenter().addObserver(self, selector: "displayAlert", name: "ErrorOccured", object: nil)

In the displayAlert instance method you could display your alert.

Converting Python dict to kwargs?

Here is a complete example showing how to use the ** operator to pass values from a dictionary as keyword arguments.

>>> def f(x=2):
...     print(x)
... 
>>> new_x = {'x': 4}
>>> f()        #    default value x=2
2
>>> f(x=3)     #   explicit value x=3
3
>>> f(**new_x) # dictionary value x=4 
4

jQuery if checkbox is checked

If checked:

$( "SELECTOR" ).attr( "checked" )  // Returns ‘true’ if present on the element, returns undefined if not present
$( "SELECTOR" ).prop( "checked" ) // Returns true if checked, false if unchecked.
$( "SELECTOR" ).is( ":checked" ) // Returns true if checked, false if unchecked.

Get the checked val:

$( "SELECTOR:checked" ).val()

Get the checked val numbers:

$( "SELECTOR:checked" ).length

Check or uncheck checkbox

$( "SELECTOR" ).prop( "disabled", false );
$( "SELECTOR" ).prop( "checked", true );

AngularJS - get element attributes values

Use Jquery functions

<Button id="myPselector" data-id="1234">HI</Button> 
console.log($("#myPselector").attr('data-id'));

How to execute powershell commands from a batch file?

This solution is similar to walid2mi (thank you for inspiration), but allows the standard console input by the Read-Host cmdlet.

pros:

  • can be run like standard .cmd file
  • only one file for batch and powershell script
  • powershell script may be multi-line (easy to read script)
  • allows the standard console input (use the Read-Host cmdlet by standard way)

cons:

  • requires powershell version 2.0+

Commented and runable example of batch-ps-script.cmd:

<# : Begin batch (batch script is in commentary of powershell v2.0+)
@echo off
: Use local variables
setlocal
: Change current directory to script location - useful for including .ps1 files
cd %~dp0
: Invoke this file as powershell expression
powershell -executionpolicy remotesigned -Command "Invoke-Expression $([System.IO.File]::ReadAllText('%~f0'))"
: Restore environment variables present before setlocal and restore current directory
endlocal
: End batch - go to end of file
goto:eof
#>
# here start your powershell script

# example: include another .ps1 scripts (commented, for quick copy-paste and test run)
#. ".\anotherScript.ps1"

# example: standard input from console
$variableInput = Read-Host "Continue? [Y/N]"
if ($variableInput -ne "Y") {
    Write-Host "Exit script..."
    break
}

# example: call standard powershell command
Get-Item .

Snippet for .cmd file:

<# : batch script
@echo off
setlocal
cd %~dp0
powershell -executionpolicy remotesigned -Command "Invoke-Expression $([System.IO.File]::ReadAllText('%~f0'))"
endlocal
goto:eof
#>
# here write your powershell commands...

How to truncate milliseconds off of a .NET DateTime

This is my version of the extension methods posted here and in similar questions. This validates the ticks value in an easy to read way and preserves the DateTimeKind of the original DateTime instance. (This has subtle but relevant side effects when storing to a database like MongoDB.)

If the true goal is to truncate a DateTime to a specified value (i.e. Hours/Minutes/Seconds/MS) I recommend implementing this extension method in your code instead. It ensures that you can only truncate to a valid precision and it preserves the important DateTimeKind metadata of your original instance:

public static DateTime Truncate(this DateTime dateTime, long ticks)
{
    bool isValid = ticks == TimeSpan.TicksPerDay 
        || ticks == TimeSpan.TicksPerHour 
        || ticks == TimeSpan.TicksPerMinute 
        || ticks == TimeSpan.TicksPerSecond 
        || ticks == TimeSpan.TicksPerMillisecond;

    // https://stackoverflow.com/questions/21704604/have-datetime-now-return-to-the-nearest-second
    return isValid 
        ? DateTime.SpecifyKind(
            new DateTime(
                dateTime.Ticks - (dateTime.Ticks % ticks)
            ),
            dateTime.Kind
        )
        : throw new ArgumentException("Invalid ticks value given. Only TimeSpan tick values are allowed.");
}

Then you can use the method like this:

DateTime dateTime = DateTime.UtcNow.Truncate(TimeSpan.TicksPerMillisecond);

dateTime.Kind => DateTimeKind.Utc

Function for Factorial in Python

def factorial(n):
    if n < 2:
        return 1
    return n * factorial(n - 1)

Setting width/height as percentage minus pixels

Presuming 17px header height

List css:

height: 100%;
padding-top: 17px;

Header css:

height: 17px;
float: left;
width: 100%;

How to find index position of an element in a list when contains returns true

int indexOf() can be used. It returns -1 if no matching finds

How can I remove a style added with .css() function?

2018

there is native API for that

element.style.removeProperty(propery)

What is the current choice for doing RPC in Python?

Since I've asked this question, I've started using python-symmetric-jsonrpc. It is quite good, can be used between python and non-python software and follow the JSON-RPC standard. But it lacks some examples.

What's the difference between "app.render" and "res.render" in express.js?

Here are some differences:

  1. You can call app.render on root level and res.render only inside a route/middleware.

  2. app.render always returns the html in the callback function, whereas res.render does so only when you've specified the callback function as your third parameter. If you call res.render without the third parameter/callback function the rendered html is sent to the client with a status code of 200.

    Take a look at the following examples.

    • app.render

      app.render('index', {title: 'res vs app render'}, function(err, html) {
          console.log(html)
      });
      
      // logs the following string (from default index.jade)
      <!DOCTYPE html><html><head><title>res vs app render</title><link rel="stylesheet" href="/stylesheets/style.css"></head><body><h1>res vs app render</h1><p>Welcome to res vs app render</p></body></html>
      
    • res.render without third parameter

      app.get('/render', function(req, res) {
          res.render('index', {title: 'res vs app render'})
      })
      
      // also renders index.jade but sends it to the client 
      // with status 200 and content-type text/html on GET /render
      
    • res.render with third parameter

      app.get('/render', function(req, res) {
          res.render('index', {title: 'res vs app render'}, function(err, html) {
              console.log(html);
              res.send('done');
          })
      })
      
      // logs the same as app.render and sends "done" to the client instead 
      // of the content of index.jade
      
  3. res.render uses app.render internally to render template files.

  4. You can use the render functions to create html emails. Depending on your structure of your app, you might not always have acces to the app object.

    For example inside an external route:

    app.js

    var routes = require('routes');
    
    app.get('/mail', function(req, res) {
        // app object is available -> app.render
    })
    
    app.get('/sendmail', routes.sendmail);
    

    routes.js

    exports.sendmail = function(req, res) {
        // can't use app.render -> therefore res.render
    }
    

Get Enum from Description attribute

The solution works good except if you have a Web Service.

You would need to do the Following as the Description Attribute is not serializable.

[DataContract]
public enum ControlSelectionType
{
    [EnumMember(Value = "Not Applicable")]
    NotApplicable = 1,
    [EnumMember(Value = "Single Select Radio Buttons")]
    SingleSelectRadioButtons = 2,
    [EnumMember(Value = "Completely Different Display Text")]
    SingleSelectDropDownList = 3,
}

public static string GetDescriptionFromEnumValue(Enum value)
{
        EnumMemberAttribute attribute = value.GetType()
            .GetField(value.ToString())
            .GetCustomAttributes(typeof(EnumMemberAttribute), false)
            .SingleOrDefault() as EnumMemberAttribute;
        return attribute == null ? value.ToString() : attribute.Value;
}

What is the difference between char, nchar, varchar, and nvarchar in SQL Server?

nchar(10) is a fixed-length Unicode string of length 10. nvarchar(10) is a variable-length Unicode string with a maximum length of 10. Typically, you would use the former if all data values are 10 characters and the latter if the lengths vary.

How to set border on jPanel?

JPanel jPanel = new JPanel();

jPanel.setBorder(BorderFactory.createLineBorder(Color.black));

Here not only jPanel, you can add border to any Jcomponent

Gradle failed to resolve library in Android Studio

repositories {
    mavenCentral()
}

I added this in build.gradle, and it worked.

How do I get which JRadioButton is selected from a ButtonGroup

You must add setActionCommand to the JRadioButton then just do:

String entree = entreeGroup.getSelection().getActionCommand();

Example:

java = new JRadioButton("Java");
java.setActionCommand("Java");
c = new JRadioButton("C/C++");
c.setActionCommand("c");
System.out.println("Selected Radio Button: " + 
                    buttonGroup.getSelection().getActionCommand());

IndentationError: unexpected unindent WHY?

@MaxPython The answer above is missing ":"

try:
   #do something
except:
  # print 'error/exception'

def printError(e): print e

How do I format a date with Dart?

This will work too:

DateTime today = new DateTime.now();
String dateSlug ="${today.year.toString()}-${today.month.toString().padLeft(2,'0')}-${today.day.toString().padLeft(2,'0')}";
print(dateSlug);

Why fragments, and when to use fragments instead of activities?

Fragments are of particular use in some cases like where we want to keep a navigation drawer in all our pages. You can inflate a frame layout with whatever fragment you want and still have access to the navigation drawer.

If you had used an activity, you would have had to keep the drawer in all activities which makes for redundant code. This is one interesting use of a fragment.

I'm new to Android and still think a fragment is helpful this way.

Display XML content in HTML page

Simple solution is to embed inside of a <textarea> element, which will preserve both the formatting and the angle brackets. I have also removed the border with style="border:none;" which makes the textarea invisible.

Here is a sample: http://jsfiddle.net/y9fqf/1/

Bootstrap Carousel : Remove auto slide

data-interval="false"

Add this to the corresponding div ...

MySQL equivalent of DECODE function in Oracle

If additional table doesn't fit, you can write your own function for translation.

The plus of sql function over case is, that you can use it in various places, and keep translation logic in one place.

How to hide/show more text within a certain length (like youtube)

Another possible solution that we can use 2 HTML element to store brief and complete text. Hence we can show/hide appropriate HTML element :-)

<p class="content_description" id="brief_description" style="display: block;"> blah blah blah blah blah  </p><p class="content_description" id="complete_description" style="display: none;"> blah blah blah blah blah with complete text </p>

/* jQuery code to toggle both paragraph. */

(function(){
        $('#toggle_content').on(
                'click', function(){
                                $("#complete_description").toggle();
                                $("#brief_description").toggle();
                                if ($("#complete_description").css("display") == "none") {
                                    $(this).text('More...');
                                }   else{
                                    $(this).text('Less...');
                                }
                        }
                );
    })();

How to stop the task scheduled in java.util.Timer class

You should stop the task that you have scheduled on the timer: Your timer:

Timer t = new Timer();
TimerTask tt = new TimerTask() {
    @Override
    public void run() {
        //do something
    };
}
t.schedule(tt,1000,1000);

In order to stop:

tt.cancel();
t.cancel(); //In order to gracefully terminate the timer thread

Notice that just cancelling the timer will not terminate ongoing timertasks.

How to create a file in memory for user to download, but not through server?

As mentioned before, filesaver is a great package to work with files on the client side. But, it is not do well with large files. StreamSaver.js is an alternative solution (which is pointed in FileServer.js) that can handle large files:

const fileStream = streamSaver.createWriteStream('filename.txt', size);
const writer = fileStream.getWriter();
for(var i = 0; i < 100; i++){
    var uint8array = new TextEncoder("utf-8").encode("Plain Text");
    writer.write(uint8array);
}
writer.close()

VBA module that runs other modules

As long as the macros in question are in the same workbook and you verify the names exist, you can call those macros from any other module by name, not by module.

So if in Module1 you had two macros Macro1 and Macro2 and in Module2 you had Macro3 and Macro 4, then in another macro you could call them all:

Sub MasterMacro()
    Call Macro1
    Call Macro2
    Call Macro3
    Call Macro4
End Sub

List file using ls command in Linux with full path

This prints all files, recursively, from the current directory.

find "$PWD" | awk /.ogg/ # filter .ogg files by regex
find "$PWD" | grep .ogg  # filter .ogg files by term
find "$PWD" | ack .ogg   # filter .ogg files by regex/term using https://github.com/petdance/ack2

How can I make git show a list of the files that are being tracked?

If you want to list all the files currently being tracked under the branch master, you could use this command:

git ls-tree -r master --name-only

If you want a list of files that ever existed (i.e. including deleted files):

git log --pretty=format: --name-only --diff-filter=A | sort - | sed '/^$/d'

Is it possible to capture the stdout from the sh DSL command in the pipeline

You can try to use as well this functions to capture StdErr StdOut and return code.

def runShell(String command){
    def responseCode = sh returnStatus: true, script: "${command} &> tmp.txt" 
    def output =  readFile(file: "tmp.txt")

    if (responseCode != 0){
      println "[ERROR] ${output}"
      throw new Exception("${output}")
    }else{
      return "${output}"
    }
}

Notice:

&>name means 1>name 2>name -- redirect stdout and stderr to the file name

Remove duplicated rows

The function distinct() in the dplyr package performs arbitrary duplicate removal, either from specific columns/variables (as in this question) or considering all columns/variables. dplyr is part of the tidyverse.

Data and package

library(dplyr)
dat <- data.frame(a = rep(c(1,2),4), b = rep(LETTERS[1:4],2))

Remove rows duplicated in a specific column (e.g., columna)

Note that .keep_all = TRUE retains all columns, otherwise only column a would be retained.

distinct(dat, a, .keep_all = TRUE)

  a b
1 1 A
2 2 B

Remove rows that are complete duplicates of other rows:

distinct(dat)

  a b
1 1 A
2 2 B
3 1 C
4 2 D

Lists in ConfigParser

json.loads & ast.literal_eval seems to be working but simple list within config is treating each character as byte so returning even square bracket....

meaning if config has fieldvalue = [1,2,3,4,5]

then config.read(*.cfg) config['fieldValue'][0] returning [ in place of 1