Programs & Examples On #Warm up

Fixing slow initial load for IIS

Options A, B and D seem to be in the same category since they only influence the initial start time, they do warmup of the website like compilation and loading of libraries in memory.

Using C, setting the idle timeout, should be enough so that subsequent requests to the server are served fast (restarting the app pool takes quite some time - in the order of seconds).

As far as I know, the timeout exists to save memory that other websites running in parallel on that machine might need. The price being that one time slow load time.

Besides the fact that the app pool gets shutdown in case of user inactivity, the app pool will also recycle by default every 1740 minutes (29 hours).

From technet:

Internet Information Services (IIS) application pools can be periodically recycled to avoid unstable states that can lead to application crashes, hangs, or memory leaks.

As long as app pool recycling is left on, it should be enough. But if you really want top notch performance for most components, you should also use something like the Application Initialization Module you mentioned.

Fastest way to iterate over all the chars in a String

The second one causes a new char array to be created, and all chars from the String to be copied to this new char array, so I would guess that the first one is faster (and less memory-hungry).

What does "restore purchases" in In-App purchases mean?

Is it as optional functionality.

If you won't provide it when user will try to purchase non-consumable product AppStore will restore old transaction. But your app will think that this is new transaction.

If you will provide restore mechanism then your purchase manager will see restored transaction.

If app should distinguish this options then you should provide functionality for restoring previously purchased products.

How do I change the font color in an html table?

<table>
<tbody>
<tr>
<td>
<select name="test" style="color: red;">
<option value="Basic">Basic : $30.00 USD - yearly</option>
<option value="Sustaining">Sustaining : $60.00 USD - yearly</option>
<option value="Supporting">Supporting : $120.00 USD - yearly</option>
</select>
</td>
</tr>
</tbody>
</table>

How to add buttons at top of map fragment API v2 layout

Maybe a simpler solution is to set an overlay in front of your map using FrameLayout or RelativeLayout and treating them as regular buttons in your activity. You should declare your layers in back to front order, e.g., map before buttons. I modified your layout, simplified it a little bit. Try the following layout and see if it works for you:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MapActivity" >

    <fragment xmlns:map="http://schemas.android.com/apk/res-auto"
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:scrollbars="vertical"  
        class="com.google.android.gms.maps.SupportMapFragment"/>

    <RadioGroup 
        android:id="@+id/radio_group_list_selector"
        android:layout_width="match_parent"
        android:layout_height="48dp"
        android:orientation="horizontal" 
        android:background="#80000000"
        android:padding="4dp" >

        <RadioButton
            android:id="@+id/radioPopular"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:text="@string/Popular"
            android:gravity="center_horizontal|center_vertical"
            android:layout_weight="1"
            android:background="@drawable/shape_radiobutton"
            android:textColor="@color/textcolor_radiobutton" />
        <View
            android:id="@+id/VerticalLine"
            android:layout_width="1dip"
            android:layout_height="match_parent"
            android:background="#aaa" />

        <RadioButton
            android:id="@+id/radioAZ"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:gravity="center_horizontal|center_vertical"
            android:text="@string/AZ"
            android:layout_weight="1"
            android:background="@drawable/shape_radiobutton2"
            android:textColor="@color/textcolor_radiobutton" />

        <View
            android:id="@+id/VerticalLine"
            android:layout_width="1dip"
            android:layout_height="match_parent"
            android:background="#aaa" />

        <RadioButton
            android:id="@+id/radioCategory"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:gravity="center_horizontal|center_vertical"
            android:text="@string/Category"
            android:layout_weight="1"
            android:background="@drawable/shape_radiobutton2"
            android:textColor="@color/textcolor_radiobutton" />
        <View
            android:id="@+id/VerticalLine"
            android:layout_width="1dip"
            android:layout_height="match_parent"
            android:background="#aaa" />

        <RadioButton
            android:id="@+id/radioNearBy"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:gravity="center_horizontal|center_vertical"
            android:text="@string/NearBy"
            android:layout_weight="1"
            android:background="@drawable/shape_radiobutton3"
            android:textColor="@color/textcolor_radiobutton" />
    </RadioGroup>
</FrameLayout>

How do I convert a Swift Array to a String?

In Swift 2.2 you may have to cast your array to NSArray to use componentsJoinedByString(",")

let stringWithCommas = (yourArray as NSArray).componentsJoinedByString(",")

How can I use Google's Roboto font on a website?

Old post, I know.

This is also possible using CSS @import url:

@import url(http://fonts.googleapis.com/css?family=Roboto:400,100,100italic,300,300ita??lic,400italic,500,500italic,700,700italic,900italic,900);
html, body, html * {
  font-family: 'Roboto', sans-serif;
}

Adding external resources (CSS/JavaScript/images etc) in JSP

The reason that you get the 404 File Not Found error, is that your path to CSS given as a value to the href attribute is missing context path.

An HTTP request URL contains the following parts:

http://[host]:[port][request-path]?[query-string]

The request path is further composed of the following elements:

  • Context path: A concatenation of a forward slash (/) with the context root of the servlet's web application. Example: http://host[:port]/context-root[/url-pattern]

  • Servlet path: The path section that corresponds to the component alias that activated this request. This path starts with a forward slash (/).

  • Path info: The part of the request path that is not part of the context path or the servlet path.

Read more here.


Solutions

There are several solutions to your problem, here are some of them:

1) Using <c:url> tag from JSTL

In my Java web applications I usually used <c:url> tag from JSTL when defining the path to CSS/JavaScript/image and other static resources. By doing so you can be sure that those resources are referenced always relative to the application context (context path).

If you say, that your CSS is located inside WebContent folder, then this should work:

<link type="text/css" rel="stylesheet" href="<c:url value="/globalCSS.css" />" />

The reason why it works is explained in the "JavaServer Pages™ Standard Tag Library" version 1.2 specification chapter 7.5 (emphasis mine):

7.5 <c:url>
Builds a URL with the proper rewriting rules applied.
...
The URL must be either an absolute URL starting with a scheme (e.g. "http:// server/context/page.jsp") or a relative URL as defined by JSP 1.2 in JSP.2.2.1 "Relative URL Specification". As a consequence, an implementation must prepend the context path to a URL that starts with a slash (e.g. "/page2.jsp") so that such URLs can be properly interpreted by a client browser.

NOTE
Don't forget to use Taglib directive in your JSP to be able to reference JSTL tags. Also see an example JSP page here.


2) Using JSP Expression Language and implicit objects

An alternative solution is using Expression Language (EL) to add application context:

<link type="text/css" rel="stylesheet" href="${pageContext.request.contextPath}/globalCSS.css" />

Here we have retrieved the context path from the request object. And to access the request object we have used the pageContext implicit object.


3) Using <c:set> tag from JSTL

DISCLAIMER
The idea of this solution was taken from here.

To make accessing the context path more compact than in the solution ?2, you can first use the JSTL <c:set> tag, that sets the value of an EL variable or the property of an EL variable in any of the JSP scopes (page, request, session, or application) for later access.

<c:set var="root" value="${pageContext.request.contextPath}"/>
...
<link type="text/css" rel="stylesheet" href="${root}/globalCSS.css" />

IMPORTANT NOTE
By default, in order to set the variable in such manner, the JSP that contains this set tag must be accessed at least once (including in case of setting the value in the application scope using scope attribute, like <c:set var="foo" value="bar" scope="application" />), before using this new variable. For instance, you can have several JSP files where you need this variable. So you must ether a) both set the new variable holding context path in the application scope AND access this JSP first, before using this variable in other JSP files, or b) set this context path holding variable in EVERY JSP file, where you need to access to it.


4) Using ServletContextListener

The more effective way to make accessing the context path more compact is to set a variable that will hold the context path and store it in the application scope using a Listener. This solution is similar to solution ?3, but the benefit is that now the variable holding context path is set right at the start of the web application and is available application wide, no need for additional steps.

We need a class that implements ServletContextListener interface. Here is an example of such class:

package com.example.listener;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;

@WebListener
public class AppContextListener implements ServletContextListener {

    @Override
    public void contextInitialized(ServletContextEvent event) {
        ServletContext sc = event.getServletContext();
        sc.setAttribute("ctx", sc.getContextPath());
    }

    @Override
    public void contextDestroyed(ServletContextEvent event) {}

}

Now in a JSP we can access this global variable using EL:

<link type="text/css" rel="stylesheet" href="${ctx}/globalCSS.css" />

NOTE
@WebListener annotation is available since Servlet version 3.0. If you use a servlet container or application server that supports older Servlet specifications, remove the @WebServlet annotation and instead configure the listener in the deployment descriptor (web.xml). Here is an example of web.xml file for the container that supports maximum Servlet version 2.5 (other configurations are omitted for the sake of brevity):

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                        http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    version="2.5">
    ...  
    <listener>
        <listener-class>com.example.listener.AppContextListener</listener-class>
    </listener>
    ...
</webapp>


5) Using scriptlets

As suggested by user @gavenkoa you can also use scriptlets like this:

<%= request.getContextPath() %>

For such a small thing it is probably OK, just note that generally the use of scriptlets in JSP is discouraged.


Conclusion

I personally prefer either the first solution (used it in my previous projects most of the time) or the second, as they are most clear, intuitive and unambiguous (IMHO). But you choose whatever suits you most.


Other thoughts

You can deploy your web app as the default application (i.e. in the default root context), so it can be accessed without specifying context path. For more info read the "Update" section here.

HTML 5 Favicon - Support?

The answers provided (at the time of this post) are link only answers so I thought I would summarize the links into an answer and what I will be using.

When working to create Cross Browser Favicons (including touch icons) there are several things to consider.

The first (of course) is Internet Explorer. IE does not support PNG favicons until version 11. So our first line is a conditional comment for favicons in IE 9 and below:

<!--[if IE]><link rel="shortcut icon" href="path/to/favicon.ico"><![endif]-->

To cover the uses of the icon create it at 32x32 pixels. Notice the rel="shortcut icon" for IE to recognize the icon it needs the word shortcut which is not standard. Also we wrap the .ico favicon in a IE conditional comment because Chrome and Safari will use the .ico file if it is present, despite other options available, not what we would like.

The above covers IE up to IE 9. IE 11 accepts PNG favicons, however, IE 10 does not. Also IE 10 does not read conditional comments thus IE 10 won't show a favicon. With IE 11 and Edge available I don't see IE 10 in widespread use, so I ignore this browser.

For the rest of the browsers we are going to use the standard way to cite a favicon:

<link rel="icon" href="path/to/favicon.png">

This icon should be 196x196 pixels in size to cover all devices that may use this icon.

To cover touch icons on mobile devices we are going to use Apple's proprietary way to cite a touch icon:

<link rel="apple-touch-icon-precomposed" href="apple-touch-icon-precomposed.png">

Using rel="apple-touch-icon-precomposed" will not apply the reflective shine when bookmarked on iOS. To have iOS apply the shine use rel="apple-touch-icon". This icon should be sized to 180x180 pixels as that is the current size recommend by Apple for the latest iPhones and iPads. I have read Blackberry will also use rel="apple-touch-icon-precomposed".

As a note: Chrome for Android states:

The apple-touch-* are deprecated, and will be supported only for a short time. (Written as of beta for m31 of Chrome).

Custom Tiles for IE 11+ on Windows 8.1+

IE 11+ on Windows 8.1+ does offer a way to create pinned tiles for your site.

Microsoft recommends creating a few tiles at the following size:

Small: 128 x 128

Medium: 270 x 270

Wide: 558 x 270

Large: 558 x 558

These should be transparent images as we will define a color background next.

Once these images are created you should create an xml file called browserconfig.xml with the following code:

<?xml version="1.0" encoding="utf-8"?>
<browserconfig>
  <msapplication>
    <tile>
      <square70x70logo src="images/smalltile.png"/>
      <square150x150logo src="images/mediumtile.png"/>
      <wide310x150logo src="images/widetile.png"/>
      <square310x310logo src="images/largetile.png"/>
      <TileColor>#009900</TileColor>
    </tile>
  </msapplication>
</browserconfig>

Save this xml file in the root of your site. When a site is pinned IE will look for this file. If you want to name the xml file something different or have it in a different location add this meta tag to the head:

<meta name="msapplication-config" content="path-to-browserconfig/custom-name.xml" />

For additional information on IE 11+ custom tiles and using the XML file visit Microsoft's website.

Putting it all together:

To put it all together the above code would look like this:

<!-- For IE 9 and below. ICO should be 32x32 pixels in size -->
<!--[if IE]><link rel="shortcut icon" href="path/to/favicon.ico"><![endif]-->

<!-- Touch Icons - iOS and Android 2.1+ 180x180 pixels in size. --> 
<link rel="apple-touch-icon-precomposed" href="apple-touch-icon-precomposed.png">

<!-- Firefox, Chrome, Safari, IE 11+ and Opera. 196x196 pixels in size. -->
<link rel="icon" href="path/to/favicon.png">

Windows Phone Live Tiles

If a user is using a Windows Phone they can pin a website to the start screen of their phone. Unfortunately, when they do this it displays a screenshot of your phone, not a favicon (not even the MS specific code referenced above). To make a "Live Tile" for Windows Phone Users for your website one must use the following code:

Here are detailed instructions from Microsoft but here is a synopsis:

Step 1

Create a square image for your website, to support hi-res screens create it at 768x768 pixels in size.

Step 2

Add a hidden overlay of this image. Here is example code from Microsoft:

<div id="TileOverlay" onclick="ToggleTileOverlay()" style='background-color: Highlight; height: 100%; width: 100%; top: 0px; left: 0px; position: fixed; color: black; visibility: hidden'>
  <img src="customtile.png" width="320" height="320" />
  <div style='margin-top: 40px'>
     Add text/graphic asking user to pin to start using the menu...
  </div>
</div>

Step 3

You then can add thew following line to add a pin to start link:

<a href="javascript:ToggleTileOverlay()">Pin this site to your start screen</a>

Microsoft recommends that you detect windows phone and only show that link to those users since it won't work for other users.

Step 4

Next you add some JS to toggle the overlay visibility

<script>
function ToggleTileOverlay() {
 var newVisibility =     (document.getElementById('TileOverlay').style.visibility == 'visible') ? 'hidden' : 'visible';
 document.getElementById('TileOverlay').style.visibility =    newVisibility;
}
</script>

Note on Sizes

I am using one size as every browser will scale down the image as necessary. I could add more HTML to specify multiple sizes if desired for those with a lower bandwidth but I am already compressing the PNG files heavily using TinyPNG and I find this unnecessary for my purposes. Also, according to philippe_b's answer Chrome and Firefox have bugs that cause the browser to load all sizes of icons. Using one large icon may be better than multiple smaller ones because of this.

Further Reading

For those who would like more details see the links below:

When and how should I use a ThreadLocal variable?

ThreadLocal is useful, when you want to have some state that should not be shared amongst different threads, but it should be accessible from each thread during its whole lifetime.

As an example, imagine a web application, where each request is served by a different thread. Imagine that for each request you need a piece of data multiple times, which is quite expensive to compute. However, that data might have changed for each incoming request, which means that you can't use a plain cache. A simple, quick solution to this problem would be to have a ThreadLocal variable holding access to this data, so that you have to calculate it only once for each request. Of course, this problem can also be solved without the use of ThreadLocal, but I devised it for illustration purposes.

That said, have in mind that ThreadLocals are essentially a form of global state. As a result, it has many other implications and should be used only after considering all the other possible solutions.

Having services in React application

The first answer doesn't reflect the current Container vs Presenter paradigm.

If you need to do something, like validate a password, you'd likely have a function that does it. You'd be passing that function to your reusable view as a prop.

Containers

So, the correct way to do it is to write a ValidatorContainer, which will have that function as a property, and wrap the form in it, passing the right props in to the child. When it comes to your view, your validator container wraps your view and the view consumes the containers logic.

Validation could be all done in the container's properties, but it you're using a 3rd party validator, or any simple validation service, you can use the service as a property of the container component and use it in the container's methods. I've done this for restful components and it works very well.

Providers

If there's a bit more configuration necessary, you can use a Provider/Consumer model. A provider is a high level component that wraps somewhere close to and underneath the top application object (the one you mount) and supplies a part of itself, or a property configured in the top layer, to the context API. I then set my container elements to consume the context.

The parent/child context relations don't have to be near each other, just the child has to be descended in some way. Redux stores and the React Router function in this way. I've used it to provide a root restful context for my rest containers (if I don't provide my own).

(note: the context API is marked experimental in the docs, but I don't think it is any more, considering what's using it).

_x000D_
_x000D_
//An example of a Provider component, takes a preconfigured restful.js_x000D_
//object and makes it available anywhere in the application_x000D_
export default class RestfulProvider extends React.Component {_x000D_
 constructor(props){_x000D_
  super(props);_x000D_
_x000D_
  if(!("restful" in props)){_x000D_
   throw Error("Restful service must be provided");_x000D_
  }_x000D_
 }_x000D_
_x000D_
 getChildContext(){_x000D_
  return {_x000D_
   api: this.props.restful_x000D_
  };_x000D_
 }_x000D_
_x000D_
 render() {_x000D_
  return this.props.children;_x000D_
 }_x000D_
}_x000D_
_x000D_
RestfulProvider.childContextTypes = {_x000D_
 api: React.PropTypes.object_x000D_
};
_x000D_
_x000D_
_x000D_

Middleware

A further way I haven't tried, but seen used, is to use middleware in conjunction with Redux. You define your service object outside the application, or at least, higher than the redux store. During store creation, you inject the service into the middleware and the middleware handles any actions that affect the service.

In this way, I could inject my restful.js object into the middleware and replace my container methods with independent actions. I'd still need a container component to provide the actions to the form view layer, but connect() and mapDispatchToProps have me covered there.

The new v4 react-router-redux uses this method to impact the state of the history, for example.

_x000D_
_x000D_
//Example middleware from react-router-redux_x000D_
//History is our service here and actions change it._x000D_
_x000D_
import { CALL_HISTORY_METHOD } from './actions'_x000D_
_x000D_
/**_x000D_
 * This middleware captures CALL_HISTORY_METHOD actions to redirect to the_x000D_
 * provided history object. This will prevent these actions from reaching your_x000D_
 * reducer or any middleware that comes after this one._x000D_
 */_x000D_
export default function routerMiddleware(history) {_x000D_
  return () => next => action => {_x000D_
    if (action.type !== CALL_HISTORY_METHOD) {_x000D_
      return next(action)_x000D_
    }_x000D_
_x000D_
    const { payload: { method, args } } = action_x000D_
    history[method](...args)_x000D_
  }_x000D_
}
_x000D_
_x000D_
_x000D_

get list of pandas dataframe columns based on data type

The most direct way to get a list of columns of certain dtype e.g. 'object':

df.select_dtypes(include='object').columns

For example:

>>df = pd.DataFrame([[1, 2.3456, 'c', 'd', 78]], columns=list("ABCDE"))
>>df.dtypes

A      int64
B    float64
C     object
D     object
E      int64
dtype: object

To get all 'object' dtype columns:

>>df.select_dtypes(include='object').columns

Index(['C', 'D'], dtype='object')

For just the list:

>>list(df.select_dtypes(include='object').columns)

['C', 'D']   

Post a json object to mvc controller with jquery and ajax

What am I doing incorrectly?

You have to convert html to javascript object, and then as a second step to json throug JSON.Stringify.

How can I receive a json object in the controller?

View:

<script src="https://code.jquery.com/jquery-3.1.0.js"></script>
<script src="https://raw.githubusercontent.com/marioizquierdo/jquery.serializeJSON/master/jquery.serializejson.js"></script>

var obj = $("#form1").serializeJSON({ useIntKeysAsArrayIndex: true });
$.post("http://localhost:52161/Default/PostRawJson/", { json: JSON.stringify(obj) });

<form id="form1" method="post">
<input name="OrderDate" type="text" /><br />
<input name="Item[0][Id]" type="text" /><br />
<input name="Item[1][Id]" type="text" /><br />
<button id="btn" onclick="btnClick()">Button</button>
</form>

Controller:

public void PostRawJson(string json)
{
    var order = System.Web.Helpers.Json.Decode(json);
    var orderDate = order.OrderDate;
    var secondOrderId = order.Item[1].Id;
}

How to switch Python versions in Terminal?

You can just specify the python version when running a program:

for python 2:

python filename.py

for python 3:

python3 filename.py

How to properly override clone method?

There are two cases in which the CloneNotSupportedException will be thrown:

  1. The class being cloned does not implemented Cloneable (assuming that the actual cloning eventually defers to Object's clone method). If the class you are writing this method in implements Cloneable, this will never happen (since any sub-classes will inherit it appropriately).
  2. The exception is explicitly thrown by an implementation - this is the recommended way to prevent clonability in a subclass when the superclass is Cloneable.

The latter case cannot occur in your class (as you're directly calling the superclass' method in the try block, even if invoked from a subclass calling super.clone()) and the former should not since your class clearly should implement Cloneable.

Basically, you should log the error for sure, but in this particular instance it will only happen if you mess up your class' definition. Thus treat it like a checked version of NullPointerException (or similar) - it will never be thrown if your code is functional.


In other situations you would need to be prepared for this eventuality - there is no guarantee that a given object is cloneable, so when catching the exception you should take appropriate action depending on this condition (continue with the existing object, take an alternative cloning strategy e.g. serialize-deserialize, throw an IllegalParameterException if your method requires the parameter by cloneable, etc. etc.).

Edit: Though overall I should point out that yes, clone() really is difficult to implement correctly and difficult for callers to know whether the return value will be what they want, doubly so when you consider deep vs shallow clones. It's often better just to avoid the whole thing entirely and use another mechanism.

Error "There is already an open DataReader associated with this Command which must be closed first" when using 2 distinct commands

You can get such a problem when you are two different commands on same connection - especially calling the second command in a loop. That is calling the second command for each record returned from the first command. If there are some 10,000 records returned by the first command, this issue will be more likely.

I used to avoid such a scenario by making it as a single command.. The first command returns all the required data and load it into a DataTable.

Note: MARS may be a solution - but it can be risky and many people dislike it.

Reference

  1. What does "A severe error occurred on the current command. The results, if any, should be discarded." SQL Azure error mean?
  2. Linq-To-Sql and MARS woes - A severe error occurred on the current command. The results, if any, should be discarded
  3. Complex GROUP BY on DataTable

module.exports vs exports in Node.js

Basically the answer lies in what really happens when a module is required via require statement. Assuming this is the first time the module is being required.

For example:

var x = require('file1.js');

contents of file1.js:

module.exports = '123';

When the above statement is executed, a Module object is created. Its constructor function is:

function Module(id, parent) {
    this.id = id;
    this.exports = {};
    this.parent = parent;
    if (parent && parent.children) {
        parent.children.push(this);
    }

    this.filename = null;
    this.loaded = false;
    this.children = [];
}

As you see each module object has a property with name exports. This is what is eventually returned as part of require.

Next step of require is to wrap the contents of file1.js into an anonymous function like below:

(function (exports, require, module, __filename, __dirname) { 
    //contents from file1.js
    module.exports = '123;
});

And this anonymous function is invoked the following way, module here refers to the Module Object created earlier.

(function (exports, require, module, __filename, __dirname) { 
    //contents from file1.js
    module.exports = '123;
}) (module.exports,require, module, "path_to_file1.js","directory of the file1.js");

As we can see inside the function, exports formal argument refers to module.exports. In essence it's a convenience provided to the module programmer.

However this convenience need to be exercised with care. In any case if trying to assign a new object to exports ensure we do it this way.

exports = module.exports = {};

If we do it following way wrong way, module.exports will still be pointing to the object created as part of module instance.

exports = {};

As as result adding anything to the above exports object will have no effect to module.exports object and nothing will be exported or returned as part of require.

SQL Server - Case Statement

We can use case statement Like this

select Name,EmailId,gender=case 
when gender='M' then 'F'
when gender='F' then 'M'
end
 from [dbo].[Employees]

WE can also it as follow.

select Name,EmailId,case gender
when 'M' then 'F'
when 'F' then 'M'
end
 from [dbo].[Employees]

How can I make SMTP authenticated in C#

How do you send the message?

The classes in the System.Net.Mail namespace (which is probably what you should use) has full support for authentication, either specified in Web.config, or using the SmtpClient.Credentials property.

Java RegEx meta character (.) and ordinary dot?

Solutions proposed by the other members don't work for me.

But I found this :

to escape a dot in java regexp write [.]

android ellipsize multiline textview

Extend TextView and override these methods:

CharSequence origText = "";
int maxLines = 2;

@Override
public void setText(CharSequence text, BufferType type) {
    super.setText(text, type);
    origText = text;
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

    CharSequence text = origText;
    onPreDraw();

    while(getLineCount() > maxLines) {
        text = text.subSequence(0, text.length()-1);
        super.setText(text + "...");
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        onPreDraw();
    }

}

TypeError: 'tuple' object does not support item assignment when swapping values

Evaluating "1,2,3" results in (1, 2, 3), a tuple. As you've discovered, tuples are immutable. Convert to a list before processing.

Android Studio don't generate R.java for my import project

For me the problem with the R class has been related to automatically organized imports.

As AndroidStudio has the option to allow the automatic imports, it took the wrong R class and thats why the ids have not been found and Gradle was throwing errors!

So check if the import to the R class is referencing to the one you need.

Get selected option from select element

The above would very well work, but it seems you have missed the jQuery typecast for the dropdown text. Other than that it would be advisable to use .val() to set text for an input text type element. With these changes the code would look like the following:

    $('#txtEntry2').val($('#ddlCodes option:selected').text());

Why use String.Format?

One reason it is not preferable to write the string like 'string +"Value"+ string' is because of Localization. In cases where localization is occurring we want the localized string to be correctly formatted, which could be very different from the language being coded in.

For example we need to show the following error in different languages:

MessageBox.Show(String.Format(ErrorManager.GetError("PIDV001").Description, proposalvalue.ProposalSource)

where

'ErrorCollector.GetError("ERR001").ErrorDescription' returns a string like "Your ID {0} is not valid". This message must be localized in many languages. In that case we can't use + in C#. We need to follow string.format.

Rails: Default sort order for a rails model?

default_scope

This works for Rails 4+:

class Book < ActiveRecord::Base
  default_scope { order(created_at: :desc) }
end

For Rails 2.3, 3, you need this instead:

default_scope order('created_at DESC')

For Rails 2.x:

default_scope :order => 'created_at DESC'

Where created_at is the field you want the default sorting to be done on.

Note: ASC is the code to use for Ascending and DESC is for descending (desc, NOT dsc !).

scope

Once you're used to that you can also use scope:

class Book < ActiveRecord::Base
  scope :confirmed, :conditions => { :confirmed => true }
  scope :published, :conditions => { :published => true }
end

For Rails 2 you need named_scope.

:published scope gives you Book.published instead of Book.find(:published => true).

Since Rails 3 you can 'chain' those methods together by concatenating them with periods between them, so with the above scopes you can now use Book.published.confirmed.

With this method, the query is not actually executed until actual results are needed (lazy evaluation), so 7 scopes could be chained together but only resulting in 1 actual database query, to avoid performance problems from executing 7 separate queries.

You can use a passed in parameter such as a date or a user_id (something that will change at run-time and so will need that 'lazy evaluation', with a lambda, like this:

scope :recent_books, lambda 
  { |since_when| where("created_at >= ?", since_when) }
  # Note the `where` is making use of AREL syntax added in Rails 3.

Finally you can disable default scope with:

Book.with_exclusive_scope { find(:all) } 

or even better:

Book.unscoped.all

which will disable any filter (conditions) or sort (order by).

Note that the first version works in Rails2+ whereas the second (unscoped) is only for Rails3+


So ... if you're thinking, hmm, so these are just like methods then..., yup, that's exactly what these scopes are!
They are like having def self.method_name ...code... end but as always with ruby they are nice little syntactical shortcuts (or 'sugar') to make things easier for you!

In fact they are Class level methods as they operate on the 1 set of 'all' records.

Their format is changing however, with rails 4 there are deprecation warning when using #scope without passing a callable object. For example scope :red, where(color: 'red') should be changed to scope :red, -> { where(color: 'red') }.

As a side note, when used incorrectly, default_scope can be misused/abused.
This is mainly about when it gets used for actions like where's limiting (filtering) the default selection (a bad idea for a default) rather than just being used for ordering results.
For where selections, just use the regular named scopes. and add that scope on in the query, e.g. Book.all.published where published is a named scope.

In conclusion, scopes are really great and help you to push things up into the model for a 'fat model thin controller' DRYer approach.

final keyword in method parameters

Java always makes a copy of parameters before sending them to methods. This means the final doesn't mean any difference for the calling code. This only means that inside the method the variables can not be reassigned.

Note that if you have a final object, you can still change the attributes of the object. This is because objects in Java really are pointers to objects. And only the pointer is copied (and will be final in your method), not the actual object.

How do you truncate all tables in a database using TSQL?

Before truncating the tables you have to remove all foreign keys. Use this script to generate final scripts to drop and recreate all foreign keys in database. Please set the @action variable to 'CREATE' or 'DROP'.

How do I read a string entered by the user in C?

On BSD systems and Android you can also use fgetln:

#include <stdio.h>

char *
fgetln(FILE *stream, size_t *len);

Like so:

size_t line_len;
const char *line = fgetln(stdin, &line_len);

The line is not null terminated and contains \n (or whatever your platform is using) in the end. It becomes invalid after the next I/O operation on stream. You are allowed to modify the returned line buffer.

.war vs .ear file

Ear files provide more options to configure the interaction with the application server.

For example: if the hibernate version of the application server is older than the one provided by your dependencies, you can add the following to ear-deployer-jboss-beans.xml for JBOSS to isolate classloaders and avoid conflicts:

<bean name="EARClassLoaderDeployer" class="org.jboss.deployment.EarClassLoaderDeployer">    
  <property name="isolated">true</property>
</bean>

or to src/main/application/META-INF/jboss-app.xml :

<?xml version="1.0"?>
<jboss-app>
<loader-repository>
    loader=nameofyourear.ear
<loader-repository-config>java2ParentDelegation=false</loader-repository-config>
</loader-repository>
</jboss-app> 

This will make sure that there is no classloader conflict between your application and the application server.

Normally the classloader mechanism works like this:

When a class loading request is presented to a class loader, it first asks its parent class loader to fulfill the request. The parent, in turn, asks its parent for the class until the request reaches the top of the hierarchy. If the class loader at the top of the hierarchy cannot fulfill the request, then the child class loader that called it is responsible for loading the class.

By isolating the classloaders, your ear classloader will not look in the parent (=JBoss / other AS classloader). As far is I know, this is not possible with war files.

Google Maps shows "For development purposes only"

It seems to me that when it displays the "For development purposes only", one cannot see the map configurations as well while developing(or rather playing around with the configurations). In my case I have not enabled billing to be associated with the API I am using and I am thinking that's the reason why its behaving this way.

curl: (60) SSL certificate problem: unable to get local issuer certificate

Relating to 'SSL certificate problem: unable to get local issuer certificate' error. It is important to note that this applies to the system sending the CURL request, and NOT the server receiving the request.

  1. Download the latest cacert.pem from https://curl.haxx.se/ca/cacert.pem

  2. Add the following line to php.ini: (if this is shared hosting and you don't have access to php.ini then you could add this to .user.ini in public_html).

    curl.cainfo="/path/to/downloaded/cacert.pem"

    Make sure you enclose the path within double quotation marks!!!

  3. By default, the FastCGI process will parse new files every 300 seconds (if required you can change the frequency by adding a couple of files as suggested here https://ss88.uk/blog/fast-cgi-and-user-ini-files-the-new-htaccess/).

Generating Fibonacci Sequence

Beginner, not too elegant, but shows the basic steps and deductions in JavaScript

/* Array Four Million Numbers */
var j = [];
var x = [1,2];
var even = [];
for (var i = 1;i<4000001;i++){
   j.push(i);
    }
// Array Even Million
i = 1;
while (i<4000001){
    var k = j[i] + j[i-1];
    j[i + 1]  = k;
    if (k < 4000001){
        x.push(k);
        }
    i++;
    }
var total = 0;
for (w in x){
    if (x[w] %2 === 0){
        even.push(x[w]);
        }
 }
for (num in even){
    total += even[num];
 }
console.log(x);
console.log(even);
console.log(total); 

CSS div element - how to show horizontal scroll bars only?

you can also make it overflow: auto and give a maximum fixed height and width that way, when the text or whatever is in there, overflows it'll show only the required scrollbar

java.io.StreamCorruptedException: invalid stream header: 54657374

You can't expect ObjectInputStream to automagically convert text into objects. The hexadecimal 54657374 is "Test" as text. You must be sending it directly as bytes.

jQuery toggle animation

$('.login').toggle(
    function(){
        $('#panel').animate({
            height: "150", 
            padding:"20px 0",
            backgroundColor:'#000000',
            opacity:.8
        }, 500);
        $('#otherdiv').animate({
            //otherdiv properties here
        }, 500);
    },
    function(){
        $('#panel').animate({
            height: "0", 
            padding:"0px 0",
            opacity:.2
        }, 500);     
        $('#otherdiv').animate({
            //otherdiv properties here
        }, 500);
});

requestFeature() must be called before adding content

Doesn't the error exactly tell you what's wrong? You're calling requestWindowFeature and setFeatureInt after you're calling setContentView.

By the way, why are you calling setContentView twice?

Check if element at position [x] exists in the list

int? here = (list.ElementAtOrDefault(2) != 0 ? list[2]:(int?) null);

What's the difference of $host and $http_host in Nginx

$host is a variable of the Core module.

$host

This variable is equal to line Host in the header of request or name of the server processing the request if the Host header is not available.

This variable may have a different value from $http_host in such cases: 1) when the Host input header is absent or has an empty value, $host equals to the value of server_name directive; 2)when the value of Host contains port number, $host doesn't include that port number. $host's value is always lowercase since 0.8.17.

$http_host is also a variable of the same module but you won't find it with that name because it is defined generically as $http_HEADER (ref).

$http_HEADER

The value of the HTTP request header HEADER when converted to lowercase and with 'dashes' converted to 'underscores', e.g. $http_user_agent, $http_referer...;


Summarizing:

  • $http_host equals always the HTTP_HOST request header.
  • $host equals $http_host, lowercase and without the port number (if present), except when HTTP_HOST is absent or is an empty value. In that case, $host equals the value of the server_name directive of the server which processed the request.

The target principal name is incorrect. Cannot generate SSPI context

In case anyone is wondering, I untangled the MS terminology:

Target = (active directory) target

Active directory target = target server running the domain controller

Domain controller = server that verifies your login information

Principal name = your windows username

SSPI = security support provider interface

Security support provider interface = software interface that manages "authenticated 
communications" and allows SSPs like TLS to allow SSL, among others

SSP = security support provider (SSPI implementation)

TLS/SSL = you should already know this
 

= Can't verify your password.

Get hostname of current request in node.js Express

If you need a fully qualified domain name and have no HTTP request, on Linux, you could use:

var child_process = require("child_process");

child_process.exec("hostname -f", function(err, stdout, stderr) {
  var hostname = stdout.trim();
});

Turn off display errors using file "php.ini"

I always use something like this in a configuration file:

// Toggle this to change the setting
define('DEBUG', true);

// You want all errors to be triggered
error_reporting(E_ALL);

if(DEBUG == true)
{
    // You're developing, so you want all errors to be shown
    display_errors(true);

    // Logging is usually overkill during development
    log_errors(false);
}
else
{
    // You don't want to display errors on a production environment
    display_errors(false);

    // You definitely want to log any occurring
    log_errors(true);
}

This allows easy toggling between debug settings. You can improve this further by checking on which server the code is running (development, test, acceptance, and production) and change your settings accordingly.

Note that no errors will be logged if error_reporting is set to 0, as cleverly remarked by Korri.

How to prevent caching of my Javascript file?

Add a random query string to the src

You could either do this manually by incrementing the querystring each time you make a change:

<script src="test.js?version=1"></script>

Or if you are using a server side language, you could automatically generate this:

ASP.NET:

<script src="test.js?rndstr=<%= getRandomStr() %>"></script>

More info on cache-busting can be found here:

https://curtistimson.co.uk/post/front-end-dev/what-is-cache-busting/

PowerShell: Run command from script's directory

This would work fine.

Push-Location $PSScriptRoot

Write-Host CurrentDirectory $CurDir

Getting unix timestamp from Date()

In java 8, it's convenient to use the new date lib and getEpochSecond method to get the timestamp (it's in second)

Instant.now().getEpochSecond();

Redirect on Ajax Jquery Call

For ExpressJs router:

router.post('/login', async(req, res) => {
    return res.send({redirect: '/yoururl'});
})

Client-side:

    success: function (response) {
        if (response.redirect) {
            window.location = response.redirect
        }
    },

JavaScript Array to Set

What levi said about passing it into the constructor is correct, but you could also use an object.

I think what Veverke is trying to say is that you could easily use the delete keyword on an object to achieve the same effect.

I think you're confused by the terminology; properties are components of the object that you can use as named indices (if you want to think of it that way).

Try something like this:

var obj = {
    "bob": "dole",
    "mr.": "peabody",
    "darkwing": "duck"
};

Then, you could just do this:

delete obj["bob"];

The structure of the object would then be this:

{
    "mr.": "peabody",
    "darkwing": "duck"
}

Which has the same effect.

Checking if a collection is empty in Java: which is the best method?

You should absolutely use isEmpty(). Computing the size() of an arbitrary list could be expensive. Even validating whether it has any elements can be expensive, of course, but there's no optimization for size() which can't also make isEmpty() faster, whereas the reverse is not the case.

For example, suppose you had a linked list structure which didn't cache the size (whereas LinkedList<E> does). Then size() would become an O(N) operation, whereas isEmpty() would still be O(1).

Additionally of course, using isEmpty() states what you're actually interested in more clearly.

How do I add a resources folder to my Java project in Eclipse

If you have multiple sub-projects then you need to add the resources folder to each project's run configuration class path like so:

class path

Ensure the new path is top of the entries and then the runtime will check that path first for any resources (before checking sub-paths)

How to change package name in flutter?

Change name attribute in pubspec.yaml (line 1)

For the name of apk, change android:label in AndroidManifest.xml

Having both a Created and Last Updated timestamp columns in MySQL 4.0

From the MySQL 5.5 documentation:

One TIMESTAMP column in a table can have the current timestamp as the default value for initializing the column, as the auto-update value, or both. It is not possible to have the current timestamp be the default value for one column and the auto-update value for another column.

Changes in MySQL 5.6.5:

Previously, at most one TIMESTAMP column per table could be automatically initialized or updated to the current date and time. This restriction has been lifted. Any TIMESTAMP column definition can have any combination of DEFAULT CURRENT_TIMESTAMP and ON UPDATE CURRENT_TIMESTAMP clauses. In addition, these clauses now can be used with DATETIME column definitions. For more information, see Automatic Initialization and Updating for TIMESTAMP and DATETIME.

Build error: You must add a reference to System.Runtime

@PeterMajeed's comment in the accepted answer helped me out with a related problem. I am not using the portable library, but have the same build error on a fresh Windows Server 2012 install, where I'm running TeamCity.

Installing the Microsoft .NET Framework 4.5.1 Developer Pack took care of the issue (after having separately installed the MS Build Tools).

How do I view the full content of a text or varchar(MAX) column in SQL Server 2008 Management Studio?

You are out of luck, I think. THe problem is not a SQL level problem as all other answers seem to focus on, but simply one of the user interface. Management Studio is not meant to be a general purpose / generic data access interface. It is not there to be your interface, but your administrative area, and it has serious limitations handling binary data and large test data - because people using it within the specified usage profile will not run into this problem.

Presenting large text data is simply not the planned usage.

Your only choice would be a table valued function that takes the text input and cuts it rows for every line, so that Management Studio gets a list of rows, not a single row.

Difference between getAttribute() and getParameter()

Generally, a parameter is a string value that is most commonly known for being sent from the client to the server (e.g. a form post) and retrieved from the servlet request. The frustrating exception to this is ServletContext initial parameters which are string parameters that are configured in web.xml and exist on the server.

An attribute is a server variable that exists within a specified scope i.e.:

  • application, available for the life of the entire application
  • session, available for the life of the session
  • request, only available for the life of the request
  • page (JSP only), available for the current JSP page only

MaxJsonLength exception in ASP.NET MVC during JavaScriptSerializer

I solved the issue by following this link

namespace System.Web.Mvc
{
public sealed class JsonDotNetValueProviderFactory : ValueProviderFactory
{
    public override IValueProvider GetValueProvider(ControllerContext controllerContext)
    {
        if (controllerContext == null)
            throw new ArgumentNullException("controllerContext");

        if (!controllerContext.HttpContext.Request.ContentType.StartsWith("application/json", StringComparison.OrdinalIgnoreCase))
            return null;

        var reader = new StreamReader(controllerContext.HttpContext.Request.InputStream);
        var bodyText = reader.ReadToEnd();

        return String.IsNullOrEmpty(bodyText) ? null : new DictionaryValueProvider<object>(JsonConvert.DeserializeObject<ExpandoObject>(bodyText, new ExpandoObjectConverter()), CultureInfo.CurrentCulture);
    }
}

}

protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();

        RegisterGlobalFilters(GlobalFilters.Filters);
        RegisterRoutes(RouteTable.Routes);

        //Remove and JsonValueProviderFactory and add JsonDotNetValueProviderFactory
        ValueProviderFactories.Factories.Remove(ValueProviderFactories.Factories.OfType<JsonValueProviderFactory>().FirstOrDefault());
        ValueProviderFactories.Factories.Add(new JsonDotNetValueProviderFactory());
    }

How to convert list of key-value tuples into dictionary?

If Tuple has no key repetitions, it's Simple.

tup = [("A",0),("B",3),("C",5)]
dic = dict(tup)
print(dic)

If tuple has key repetitions.

tup = [("A",0),("B",3),("C",5),("A",9),("B",4)]
dic = {}
for i, j in tup:
    dic.setdefault(i,[]).append(j)
print(dic)

When tracing out variables in the console, How to create a new line?

In ES6/ES2015 you can use string literal syntax called template literals. Template strings use backtick character instead of single quote ' or double quote marks ". They also preserve new line and tab

_x000D_
_x000D_
const roleName = 'test1';_x000D_
const role_ID = 'test2';_x000D_
const modal_ID = 'test3';_x000D_
const related = 'test4';_x000D_
        _x000D_
console.log(`_x000D_
  roleName = ${roleName}_x000D_
  role_ID = ${role_ID}_x000D_
  modal_ID = ${modal_ID}_x000D_
  related = ${related}_x000D_
`);
_x000D_
_x000D_
_x000D_

Disable scrolling in all mobile devices

The following works for me, although I did not test every single device there is to test :-)

$('body, html').css('overflow-y', 'hidden');
$('html, body').animate({
    scrollTop:0
}, 0);

Query to check index on a table

If you just need the indexed columns EXEC sp_helpindex 'TABLE_NAME'

Delete specific line from a text file?

You can actually use C# generics for this to make it real easy:

        var file = new List<string>(System.IO.File.ReadAllLines("C:\\path"));
        file.RemoveAt(12);
        File.WriteAllLines("C:\\path", file.ToArray());

Angular IE Caching issue for $http

This only line helped me (Angular 1.4.8):

$httpProvider.defaults.headers.common['Pragma'] = 'no-cache';

UPD: The problem is IE11 does aggressive caching. When I was looking into Fiddler I noticed that in F12 mode requests are sending "Pragma=no-cache" and endpoint is requested every time I visit a page. But in normal mode endpoint was requested only once at the first time when I visited the page.

How to get StackPanel's children to fill maximum space downward?

It sounds like you want a StackPanel where the final element uses up all the remaining space. But why not use a DockPanel? Decorate the other elements in the DockPanel with DockPanel.Dock="Top", and then your help control can fill the remaining space.

XAML:

<DockPanel Width="200" Height="200" Background="PowderBlue">
    <TextBlock DockPanel.Dock="Top">Something</TextBlock>
    <TextBlock DockPanel.Dock="Top">Something else</TextBlock>
    <DockPanel
        HorizontalAlignment="Stretch" 
        VerticalAlignment="Stretch" 
        Height="Auto" 
        Margin="10">

      <GroupBox 
        DockPanel.Dock="Right" 
        Header="Help" 
        Width="100" 
        Background="Beige" 
        VerticalAlignment="Stretch" 
        VerticalContentAlignment="Stretch" 
        Height="Auto">
        <TextBlock Text="This is the help that is available on the news screen." 
                   TextWrapping="Wrap" />
     </GroupBox>

      <StackPanel DockPanel.Dock="Left" Margin="10" 
           Width="Auto" HorizontalAlignment="Stretch">
          <TextBlock Text="Here is the news that should wrap around." 
                     TextWrapping="Wrap"/>
      </StackPanel>
    </DockPanel>
</DockPanel>

If you are on a platform without DockPanel available (e.g. WindowsStore), you can create the same effect with a grid. Here's the above example accomplished using grids instead:

<Grid Width="200" Height="200" Background="PowderBlue">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>
    <StackPanel Grid.Row="0">
        <TextBlock>Something</TextBlock>
        <TextBlock>Something else</TextBlock>
    </StackPanel>
    <Grid Height="Auto" Grid.Row="1" Margin="10">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="100"/>
        </Grid.ColumnDefinitions>
        <GroupBox
            Width="100"
            Height="Auto"
            Grid.Column="1"
            Background="Beige"
            Header="Help">
            <TextBlock Text="This is the help that is available on the news screen." 
              TextWrapping="Wrap"/>
        </GroupBox>
        <StackPanel Width="Auto" Margin="10" DockPanel.Dock="Left">
            <TextBlock Text="Here is the news that should wrap around." 
              TextWrapping="Wrap"/>
        </StackPanel>
    </Grid>
</Grid>

Python Replace \\ with \

You are missing, that \ is the escape character.

Look here: http://docs.python.org/reference/lexical_analysis.html at 2.4.1 "Escape Sequence"

Most importantly \n is a newline character. And \\ is an escaped escape character :D

>>> a = 'a\\\\nb'
>>> a
'a\\\\nb'
>>> print a
a\\nb
>>> a.replace('\\\\', '\\')
'a\\nb'
>>> print a.replace('\\\\', '\\')
a\nb

How to link 2 cell of excel sheet?

I Found Solution Of You Question But In Stack Not Allow to Upload Video See the link below it show better explain

How to link two (multiple) workbooks and cells in Excel...

"replace" function examples

Here's an example where I found the replace( ) function helpful for giving me insight. The problem required a long integer vector be changed into a character vector and with its integers replaced by given character values.

## figuring out replace( )
(test <- c(rep(1,3),rep(2,2),rep(3,1)))

which looks like

[1] 1 1 1 2 2 3

and I want to replace every 1 with an A and 2 with a B and 3 with a C

letts <- c("A","B","C")

so in my own secret little "dirty-verse" I used a loop

for(i in 1:3)
{test <- replace(test,test==i,letts[i])}

which did what I wanted

test
[1] "A" "A" "A" "B" "B" "C"

In the first sentence I purposefully left out that the real objective was to make the big vector of integers a factor vector and assign the integer values (levels) some names (labels).

So another way of doing the replace( ) application here would be

(test <- factor(test,labels=letts))
[1] A A A B B C
Levels: A B C

How do I hide javascript code in a webpage?

Is not possbile!

The only way is to obfuscate javascript or minify your javascript which makes it hard for the end user to reverse engineer. however its not impossible to reverse engineer.

How to check if $? is not equal to zero in unix shell scripting?

You don't need to test if $? is not 0. The shell provides && and || so you can easily branch based on implicit result of that test:

some_command && {
    # executes this block of code,
    # if some_command would result in:  $? -eq 0
} || {
    # executes this block of code,
    # if some_command would result in:  $? -ne 0
}

You can remove either branch, depending on what you want. So if you just want to test for failure (i.e. $? -ne 0):

some_command_returning_nonzero || {
    # executes this block of code when:     $? -ne 0
    # and nothing if the command succeeds:  $? -eq 0
}

However, the code you provided in the question works, as is. I'm confused that you got syntax errors & concluded that $? was a string. It's most likely that the errant code causing the syntax error was not provided with the question. This is especially evident because you claim that no one else's solutions work either. When this happens, you have to re-evaluate your assumptions.

NB: The code above may give confusing results if the code inside the braces returns an error. In that case simply use the if command instead, like this:

if some_command; then
    # executes this block of code,
    # if some_command would result in:  $? -eq 0
else
    # executes this block of code,
    # if some_command would result in:  $? -ne 0
fi

How to compare variables to undefined, if I don’t know whether they exist?

The best way is to check the type, because undefined/null/false are a tricky thing in JS. So:

if(typeof obj !== "undefined") {
    // obj is a valid variable, do something here.
}

Note that typeof always returns a string, and doesn't generate an error if the variable doesn't exist at all.

C# with MySQL INSERT parameters

comm.Parameters.Add("person", "Myname");

PHP: HTTP or HTTPS?

You should be able to do this by checking the value of $_SERVER['HTTPS'] (it should only be set when using https).

See http://php.net/manual/en/reserved.variables.server.php.

How to convert JSON object to JavaScript array?

function json2array(json){
    var result = [];
    var keys = Object.keys(json);
    keys.forEach(function(key){
        result.push(json[key]);
    });
    return result;
}

See this complete explanation: http://book.mixu.net/node/ch5.html

How can I add a new column and data to a datatable that already contains data?

Only you want to set default value parameter. This calling third overloading method.

dt.Columns.Add("MyRow", type(System.Int32),0);

Convert JSON string to array of JSON objects in Javascript

As simple as that.

var str = '{"id":1,"name":"Test1"},{"id":2,"name":"Test2"}';
 dataObj = JSON.parse(str);

Django Rest Framework File Upload

def post(self,request):
        serializer = ProductSerializer(data=request.DATA, files=request.FILES)
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data)

error: command 'gcc' failed with exit status 1 on CentOS

sudo yum install python36 python36-devel python36-libs python36-tools

if using python36, this is the best path for set up. Corrected this error for me on an aws ec2 instance

ArrayAdapter in android to create simple listview

public ArrayAdapter (Context context, int resource, int textViewResourceId, T[] objects)

I am also new to Android , so i might be wrong. But as per my understanding while using this for listview creation 2nd argument is the layout of list items. A layout consists of many views (image view,text view etc). With 3rd argument you are specifying in which view or textview you want the text to be displayed.

How to use ADB in Android Studio to view an SQLite DB

Easiest Way: Connect to Sqlite3 via ADB Shell

I haven't found any way to do that in Android Studio, but I access the db with a remote shell instead of pulling the file each time.

Find all info here: http://developer.android.com/tools/help/sqlite3.html

1- Go to your platform-tools folder in a command prompt

2- Enter the command adb devices to get the list of your devices

C:\Android\adt-bundle-windows-x86_64\sdk\platform-tools>adb devices
List of devices attached
emulator-xxxx   device

3- Connect a shell to your device:

C:\Android\adt-bundle-windows-x86_64\sdk\platform-tools>adb -s emulator-xxxx shell

4a- You can bypass this step on rooted device

run-as <your-package-name> 

4b- Navigate to the folder containing your db file:

cd data/data/<your-package-name>/databases/

5- run sqlite3 to connect to your db:

sqlite3 <your-db-name>.db

6- run sqlite3 commands that you like eg:

Select * from table1 where ...;

Note: Find more commands to run below.

SQLite cheatsheet

There are a few steps to see the tables in an SQLite database:

  1. List the tables in your database:

    .tables
    
  2. List how the table looks:

    .schema tablename
    
  3. Print the entire table:

    SELECT * FROM tablename;
    
  4. List all of the available SQLite prompt commands:

    .help
    

How can I show a message box with two buttons?

It can be done, I found it elsewhere on the web...this is no way my work ! :)

    Option Explicit
' Import
Private Declare Function GetCurrentThreadId Lib "kernel32" () As Long

Private Declare Function SetDlgItemText Lib "user32" _
    Alias "SetDlgItemTextA" _
    (ByVal hDlg As Long, _
     ByVal nIDDlgItem As Long, _
     ByVal lpString As String) As Long

Private Declare Function SetWindowsHookEx Lib "user32" _
    Alias "SetWindowsHookExA" _
    (ByVal idHook As Long, _
     ByVal lpfn As Long, _
     ByVal hmod As Long, _
     ByVal dwThreadId As Long) As Long

Private Declare Function UnhookWindowsHookEx Lib "user32" _
    (ByVal hHook As Long) As Long

' Handle to the Hook procedure
Private hHook As Long

' Hook type
Private Const WH_CBT = 5
Private Const HCBT_ACTIVATE = 5

' Constants
Public Const IDOK = 1
Public Const IDCANCEL = 2
Public Const IDABORT = 3
Public Const IDRETRY = 4
Public Const IDIGNORE = 5
Public Const IDYES = 6
Public Const IDNO = 7

Public Sub MsgBoxSmile()
    ' Set Hook
    hHook = SetWindowsHookEx(WH_CBT, _
                             AddressOf MsgBoxHookProc, _
                             0, _
                             GetCurrentThreadId)

    ' Run MessageBox
    MsgBox "Smiling Message Box", vbYesNo, "Message Box Hooking"
End Sub

Private Function MsgBoxHookProc(ByVal lMsg As Long, _
                                ByVal wParam As Long, _
                                ByVal lParam As Long) As Long

    If lMsg = HCBT_ACTIVATE Then
        SetDlgItemText wParam, IDYES, "Yes   :-)"
        SetDlgItemText wParam, IDNO, "No   :-("

        ' Release the Hook
        UnhookWindowsHookEx hHook
    End If

    MsgBoxHookProc = False
End Function

python: create list of tuples from lists

You're looking for the zip builtin function. From the docs:

>>> x = [1, 2, 3]
>>> y = [4, 5, 6]
>>> zipped = zip(x, y)
>>> zipped
[(1, 4), (2, 5), (3, 6)]

How to get the first non-null value in Java?

How about:

firstNonNull = FluentIterable.from(
    Lists.newArrayList( a, b, c, ... ) )
        .firstMatch( Predicates.notNull() )
            .or( someKnownNonNullDefault );

Java ArrayList conveniently allows null entries and this expression is consistent regardless of the number of objects to be considered. (In this form, all the objects considered need to be of the same type.)

How to "properly" print a list?

This is simple code, so if you are new you should understand it easily enough.

    mylist = ["x", 3, "b"]
    for items in mylist:
        print(items)

It prints all of them without quotes, like you wanted.

How to check if a string in Python is in ASCII?

You could use the regular expression library which accepts the Posix standard [[:ASCII:]] definition.

Facebook Open Graph not clearing cache

One thing to add, the url is case sensitive. Note that:

apps.facebook.com/HELLO

is different in the linter's eyes then

apps.facebook.com/hello

Be sure to use the exact site url that was entered in the developer settings for the app. The linter will return the properties otherwise but will not refresh the cache.

Expand div to max width when float:left is set

This is an updated solution for HTML 5 if anyone is interested & not fond of "floating".

Table works great in this case as you can set the fixed width to the table & table-cell.

.content-container{
    display: table;
    width: 300px;
}

.content .right{
    display: table-cell;   
    background-color:green;
    width: 100px;
}

http://jsfiddle.net/EAEKc/596/ original source code from @merkuro

Does Google Chrome work with Selenium IDE (as Firefox does)?

There is not a Google Chrome extension comparable to Selenium IDE.

Scirocco is only a partial (and reportedly unreliable) implementation.

There is another plugin, the Bug Buster Test Recorder, but it only works with their service. I don't know it's effectiveness.

Sahi and TestComplete can also record, but neither are free, and are not browser plugins.

iMacros is a plugin that allows record and playback, but is not geared towards testing, and is not compatible with Selenium.

It sounds like there is a demand for a tool like this, and Firefox is becoming unsupported by Selenium. So, while I know Stack Overflow isn't the forum for this, anyone interested in helping make it happen, let me know.

I'd be interested in what the limitations are and why it hasn't been done. Is it just that the official Selenium team doesn't want to support it, or is there a technical limitation?

PHP unable to load php_curl.dll extension

Add your php folder path to the System PATH and everything should work fine. It will also fix some other extensions that are broken.

How do you get the list of targets in a makefile?

I took a few answers mentioned above and compiled this one, which can also generate a nice description for each target and it works for targets with variables too.

Example Makefile:

APPS?=app1 app2

bin: $(APPS:%=%.bin)
    @# Help: A composite target that relies only on other targets

$(APPS:%=%.bin): %.bin:
    echo "build binary"
    @# Help: A target with variable name, value = $*

test:
    echo $(MAKEFLAGS)
    echo "starting test"
    @# Help: A normal target without variables

# A target without any help description
clean:
    echo $(MAKEFLAGS)
    echo "Cleaning..."

MAKEOVERRIDES =
help:
    @printf "%-20s %s\n" "Target" "Description"
    @printf "%-20s %s\n" "------" "-----------"
    @make -pqR : 2>/dev/null \
        | awk -v RS= -F: '/^# File/,/^# Finished Make data base/ {if ($$1 !~ "^[#.]") {print $$1}}' \
        | sort \
        | egrep -v -e '^[^[:alnum:]]' -e '^$@$$' \
        | xargs -I _ sh -c 'printf "%-20s " _; make _ -nB | (grep -i "^# Help:" || echo "") | tail -1 | sed "s/^# Help: //g"'

Example output:

$ make help
Target               Description
------               -----------
app1.bin             A target with variable name, value = app1
app2.bin             A target with variable name, value = app2
bin                  A composite target that relies only on other targets
clean
test                 A normal target without variables

How does it work:

The top part of the make help target works exactly as posted by mklement0 here - How do you get the list of targets in a makefile?.

After getting the list of targets, it runs make <target> -nB as a dry run for each target and parses the last line that starts with @# Help: for the description of the target. And that or an empty string is printed in a nicely formatted table.

As you can see, the variables are even expanded within the description as well, which is a huge bonus in my book :).

Send FormData with other field in AngularJS

Assume that we want to get a list of certain images from a PHP server using the POST method.

You have to provide two parameters in the form for the POST method. Here is how you are going to do.

app.controller('gallery-item', function ($scope, $http) {

    var url = 'service.php'; 

    var data = new FormData();

    data.append("function", 'getImageList');
    data.append('dir', 'all');

    $http.post(url, data, {
        transformRequest: angular.identity,
        headers: {'Content-Type': undefined}
      }).then(function (response) {

          // This function handles success
        console.log('angular:', response);

    }, function (response) {

        // this function handles error

    });
});

I have tested it on my system and it works.

get unique machine id

edit: I just saw you meant in c#. Here is a better way with unmanaged code:

ManagementClass oMClass = new ManagementClass ("Win32_NetworkAdapterConfiguration");
ManagementObjectCollection colMObj = oMCLass.GetInstances();
foreach(ManagementObject objMO in colMObj)
    Console.WriteLine(objMO["MacAddress"].ToString());

How to create the branch from specific commit in different branch

You have to do:

git branch <branch_name> <commit>

(you were interchanging the branch name and commit)

Or you can do:

git checkout -b <branch_name> <commit>

If in place of you use branch name, you get a branch out of tip of the branch.

Adding items to an object through the .push() method

Another way of doing it would be:

stuff = Object.assign(stuff, {$(this).attr('value'):$(this).attr('checked')});

Read more here: Object.assign()

Get screenshot on Windows with Python?

Worth noting that ImageGrab only works on MSWindows.

For cross platform compatibility, a person may be best off with using the wxPython library. http://wiki.wxpython.org/WorkingWithImages#A_Flexible_Screen_Capture_App

import wx
wx.App()  # Need to create an App instance before doing anything
screen = wx.ScreenDC()
size = screen.GetSize()
bmp = wx.EmptyBitmap(size[0], size[1])
mem = wx.MemoryDC(bmp)
mem.Blit(0, 0, size[0], size[1], screen, 0, 0)
del mem  # Release bitmap
bmp.SaveFile('screenshot.png', wx.BITMAP_TYPE_PNG)

CSS no text wrap

Use the css property overflow . For example:

  .item{
    width : 100px;
    overflow:hidden;
  }

The overflow property can have one of many values like ( hidden , scroll , visible ) .. you can als control the overflow in one direction only using overflow-x or overflow-y.

I hope this helps.

Hidden TextArea

An <input type=hidden> element is not a hidden input box. It is simply a form field that has a value set via markup or via scripting, not via user input. You can use it for multi-line data too, e.g.

<input type=hidden name=stuff value=
"Hello
world, how
are you?">

If the value contains the Ascii quotation mark ("), then, as for any HTML attribute, you need to use Ascii apostrophes (') as attribute value delimites or escape the quote as &quot;, e.g.

<input type=hidden name=stuff value="A &quot;funny&quot; example">

Easiest way to activate PHP and MySQL on Mac OS 10.6 (Snow Leopard), 10.7 (Lion), 10.8 (Mountain Lion)?

It's an invisible folder. Just hit Command + Shift + G (takes you to the Go to Folder menu item) and type /etc/.

Then it will take you to inside that folder.

How to hide Table Row Overflow?

If javascript is accepted as an answer, I made a jQuery plugin to address this issue (for more information about the issue see CSS: Truncate table cells, but fit as much as possible).

To use the plugin just type

$('selector').tableoverflow();

Plugin: https://github.com/marcogrcr/jquery-tableoverflow

Full example: http://jsfiddle.net/Cw7TD/3/embedded/result/

Adding VirtualHost fails: Access Forbidden Error 403 (XAMPP) (Windows 7)

For me (also XAMPP on Windows 7), this is what worked:

<Directory "C:\projects\myfolder\htdocs">`
   AllowOverride All
   Require all granted
   Options Indexes FollowSymLinks
</Directory>` 

It is this line that would cause the 403:

Order allow,deny

Tracking Google Analytics Page Views with AngularJS

Use GA 'set' to ensure routes are picked up for Google realtime analytics. Otherwise subsequent calls to GA will not show in the realtime panel.

$scope.$on('$routeChangeSuccess', function() {
    $window.ga('set', 'page', $location.url());
    $window.ga('send', 'pageview');
});

Google strongly advises this approach generally instead of passing a 3rd param in 'send'. https://developers.google.com/analytics/devguides/collection/analyticsjs/single-page-applications

how to load CSS file into jsp

I use this version

<style><%@include file="/WEB-INF/css/style.css"%></style>

How to convert MySQL time to UNIX timestamp using PHP?

Slightly abbreviated could be...

echo date("Y-m-d H:i:s", strtotime($mysqltime));

Read CSV with Scanner()

Please stop writing faulty CSV parsers!

I've seen hundreds of CSV parsers and so called tutorials for them online.

Nearly every one of them gets it wrong!

This wouldn't be such a bad thing as it doesn't affect me but people who try to write CSV readers and get it wrong tend to write CSV writers, too. And get them wrong as well. And these ones I have to write parsers for.

Please keep in mind that CSV (in order of increasing not so obviousness):

  1. can have quoting characters around values
  2. can have other quoting characters than "
  3. can even have other quoting characters than " and '
  4. can have no quoting characters at all
  5. can even have quoting characters on some values and none on others
  6. can have other separators than , and ;
  7. can have whitespace between seperators and (quoted) values
  8. can have other charsets than ascii
  9. should have the same number of values in each row, but doesn't always
  10. can contain empty fields, either quoted: "foo","","bar" or not: "foo",,"bar"
  11. can contain newlines in values
  12. can not contain newlines in values if they are not delimited
  13. can not contain newlines between values
  14. can have the delimiting character within the value if properly escaped
  15. does not use backslash to escape delimiters but...
  16. uses the quoting character itself to escape it, e.g. Frodo's Ring will be 'Frodo''s Ring'
  17. can have the quoting character at beginning or end of value, or even as only character ("foo""", """bar", """")
  18. can even have the quoted character within the not quoted value; this one is not escaped

If you think this is obvious not a problem, then think again. I've seen every single one of these items implemented wrongly. Even in major software packages. (e.g. Office-Suites, CRM Systems)

There are good and correctly working out-of-the-box CSV readers and writers out there:

If you insist on writing your own at least read the (very short) RFC for CSV.

Netbeans how to set command line arguments in Java

In NetBeans IDE 8.0 you can use a community contributed plugin https://github.com/tusharvjoshi/nbrunwithargs which will allow you to pass arguments while Run Project or Run Single File command.

For passing arguments to Run Project command either you have to set the arguments in the Project properties Run panel, or use the new command available after installing the plugin which says Run with Arguments

For passing command line arguments to a Java file having main method, just right click on the method and choose Run with Arguments command, of this plugin

UPDATE (24 mar 2014) This plugin is now available in NetBeans Plugin Portal that means it can be installed from Plugins dialog box from the available plugins shown from community contributed plugins, in NetBeans IDE 8.0

Run with Arguments plugin as shown in Plugin dialog box

jQuery ui dialog change title after load-callback

I have found simpler solution:

$('#clickToCreate').live('click', function() {
     $('#yourDialogId')
         .dialog({
              title: "Set the title to Create"
         })
         .dialog('open'); 
});


$('#clickToEdit').live('click', function() {
     $('#yourDialogId')
         .dialog({
              title: "Set the title To Edit"
         })
         .dialog('open'); 
});

Hope that helps!

std::thread calling method of class

Not so hard:

#include <thread>

void Test::runMultiThread()
{
    std::thread t1(&Test::calculate, this,  0, 10);
    std::thread t2(&Test::calculate, this, 11, 20);
    t1.join();
    t2.join();
}

If the result of the computation is still needed, use a future instead:

#include <future>

void Test::runMultiThread()
{
     auto f1 = std::async(&Test::calculate, this,  0, 10);
     auto f2 = std::async(&Test::calculate, this, 11, 20);

     auto res1 = f1.get();
     auto res2 = f2.get();
}

How to get date representing the first day of a month?

SELECT DATEADD(m, DATEDIFF(m, 0, GETDATE()), 0)

This worked perfectly. I actually added a Case statement. Thanks for the post:

SELECT Case(DATEADD(m, DATEDIFF(m, 0, GETDATE()), 0) as Date)

Check if enum exists in Java

I don't think there's a built-in way to do it without catching exceptions. You could instead use something like this:

public static MyEnum asMyEnum(String str) {
    for (MyEnum me : MyEnum.values()) {
        if (me.name().equalsIgnoreCase(str))
            return me;
    }
    return null;
}

Edit: As Jon Skeet notes, values() works by cloning a private backing array every time it is called. If performance is critical, you may want to call values() only once, cache the array, and iterate through that.

Also, if your enum has a huge number of values, Jon Skeet's map alternative is likely to perform better than any array iteration.

Can I have multiple :before pseudo-elements for the same element?

If your main element has some child elements or text, you could make use of it.

Position your main element relative (or absolute/fixed) and use both :before and :after positioned absolute (in my situation it had to be absolute, don't know about your's).

Now if you want one more pseudo-element, attach an absolute :before to one of the main element's children (if you have only text, put it in a span, now you have an element), which is not relative/absolute/fixed.

This element will start acting like his owner is your main element.

HTML

<div class="circle">
    <span>Some text</span>
</div>

CSS

.circle {
    position: relative; /* or absolute/fixed */
}

.circle:before {
    position: absolute;
    content: "";
    /* more styles: width, height, etc */
}

.circle:after {
    position: absolute;
    content: "";
    /* more styles: width, height, etc */
}

.circle span {
    /* not relative/absolute/fixed */
}

.circle span:before {
    position: absolute;
    content: "";
    /* more styles: width, height, etc */
}

How to resolve "Could not find schema information for the element/attribute <xxx>"?

I've created a new scheme based on my current app.config to get the messages to disappear. I just used the button in Visual Studio that says "Create Schema" and an xsd schema was created for me.

Save the schema in an apropriate place and see the "Properties" tab of the app.config file where there is a property named Schemas. If you click the change button there you can select to use both the original dotnetconfig schema and your own newly created one.

Java format yyyy-MM-dd'T'HH:mm:ss.SSSz to yyyy-mm-dd HH:mm:ss

String dateStr = "2016-09-17T08:14:03+00:00";
String s = dateStr.replace("Z", "+00:00");
s = s.substring(0, 22) + s.substring(23);
Date date = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ").parse(s);
Timestamp createdOn = new Timestamp(date.getTime());
mcList.setCreated_on(createdOn);

Java 7 added support for time zone descriptors according to ISO 8601. This can be use in Java 7.

Round double value to 2 decimal places

As in most languages the format is

%.2f

you can see more examples here


Edit: I also got this if your concerned about the display of the point in cases of 25.00

{
    NSNumberFormatter *fmt = [[NSNumberFormatter alloc] init];
    [fmt setPositiveFormat:@"0.##"];
    NSLog(@"%@", [fmt stringFromNumber:[NSNumber numberWithFloat:25.342]]);
    NSLog(@"%@", [fmt stringFromNumber:[NSNumber numberWithFloat:25.3]]);
    NSLog(@"%@", [fmt stringFromNumber:[NSNumber numberWithFloat:25.0]]);
}
2010-08-22 15:04:10.614 a.out[6954:903] 25.34
2010-08-22 15:04:10.616 a.out[6954:903] 25.3
2010-08-22 15:04:10.617 a.out[6954:903] 25

Built in Python hash() function

The response is absolutely no surprise: in fact

In [1]: -5768830964305142685L & 0xffffffff
Out[1]: 1934711907L

so if you want to get reliable responses on ASCII strings, just get the lower 32 bits as uint. The hash function for strings is 32-bit-safe and almost portable.

On the other side, you can't rely at all on getting the hash() of any object over which you haven't explicitly defined the __hash__ method to be invariant.

Over ASCII strings it works just because the hash is calculated on the single characters forming the string, like the following:

class string:
    def __hash__(self):
        if not self:
            return 0 # empty
        value = ord(self[0]) << 7
        for char in self:
            value = c_mul(1000003, value) ^ ord(char)
        value = value ^ len(self)
        if value == -1:
            value = -2
        return value

where the c_mul function is the "cyclic" multiplication (without overflow) as in C.

Using a dictionary to count the items in a list

I always thought that for a task that trivial, I wouldn't want to import anything. But i may be wrong, depending on collections.Counter being faster or not.

items = "Whats the simpliest way to add the list items to a dictionary "

stats = {}
for i in items:
    if i in stats:
        stats[i] += 1
    else:
        stats[i] = 1

# bonus
for i in sorted(stats, key=stats.get):
    print("%d×'%s'" % (stats[i], i))

I think this may be preferable to using count(), because it will only go over the iterable once, whereas count may search the entire thing on every iteration. I used this method to parse many megabytes of statistical data and it always was reasonably fast.

Iterating over a 2 dimensional python list

same way you did the fill in, but reverse the indexes:

>>> for j in range(columns):
...     for i in range(rows):
...        print mylist[i][j],
... 
0,0 1,0 2,0 0,1 1,1 2,1
>>> 

How to get the primary IP address of the local machine on Linux and OS X?

If you know the network interface (eth0, wlan, tun0 etc):

ifconfig eth0 | grep addr: | awk '{ print $2 }' | cut -d: -f2

typesafe select onChange event using reactjs and typescript

JSX:

<select value={ this.state.foo } onChange={this.handleFooChange}>
    <option value="A">A</option>
    <option value="B">B</option>
</select>

TypeScript:

private handleFooChange = (event: React.FormEvent<HTMLSelectElement>) => {
    const element = event.target as HTMLSelectElement;
    this.setState({ foo: element.value });
}

Package Manager Console Enable-Migrations CommandNotFoundException only in a specific VS project

I had the same issue and I tried most of the solution provided by other folks but it worked for me with below steps. I have VS 2017.

Steps:

Install-Package EntityFramework -IncludePrerelease

then create a class as

public class MyDBContext : DbContext { public MyDBContext() { } }

and at the last execute

Enable-Migrations -EnableAutomaticMigrations

What didn't work for me:

: Restarting VS.

: only "Enable-Migrations" command, which is without -EnableAutomaticMigrations.

: restoring or updating Nuget Package Manager.

My original error in the beginning was

/* The term 'enable-migration' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.At line:1 char:1 + enable-migration + ~~~~~~~~~~~~~~~~ + CategoryInfo : ObjectNotFound: (enable-migration:String) [], CommandNotFoundException */

How to import existing *.sql files in PostgreSQL 8.4?

Be careful with "/" and "\". Even on Windows the command should be in the form:

\i c:/1.sql

JavaScript blob filename without link

Working example of a download button, to save a cat photo from an url as "cat.jpg":

HTML:

<button onclick="downloadUrl('https://i.imgur.com/AD3MbBi.jpg', 'cat.jpg')">Download</button>

JavaScript:

function downloadUrl(url, filename) {
  let xhr = new XMLHttpRequest();
  xhr.open("GET", url, true);
  xhr.responseType = "blob";
  xhr.onload = function(e) {
    if (this.status == 200) {
      const blob = this.response;
      const a = document.createElement("a");
      document.body.appendChild(a);
      const blobUrl = window.URL.createObjectURL(blob);
      a.href = blobUrl;
      a.download = filename;
      a.click();
      setTimeout(() => {
        window.URL.revokeObjectURL(blobUrl);
        document.body.removeChild(a);
      }, 0);
    }
  };
  xhr.send();
}

How to remove any URL within a string in Python

You could also look at it from the other way around...

from urlparse import urlparse
[el for el in ['text1', 'FTP://somewhere.com', 'text2', 'http://blah.com:8080/foo/bar#header'] if not urlparse(el).scheme]

Performing a query on a result from another query?

I don't know if you even need to wrap it. Won't this work?

SELECT COUNT(*), SUM(DATEDIFF(now(),availables.updated_at))
FROM availables
INNER JOIN rooms    ON availables.room_id=rooms.id
WHERE availables.bookdate BETWEEN '2009-06-25' 
  AND date_add('2009-06-25', INTERVAL 4 DAY)
  AND rooms.hostel_id = 5094
GROUP BY availables.bookdate);

If your goal is to return both result sets then you'll need to store it some place temporarily.

Execution failed for task ':app:compileDebugJavaWithJavac' Android Studio 3.1 Update

I had similar issue and no errors shown in Compilation. I have tried to clean and rebuild without any success. I managed to find the issue by using Invalidate Caches/Restart from file Menu, after the restart I managed to see the compilation error.

enter image description here

Unable to install packages in latest version of RStudio and R Version.3.1.1

Please check the following to be able to install new packages:

1- In Tools -> Global Options -> Packages, uncheck the "Use Internet Explorer library/proxy for HTTP" option,

2- In Tools -> Global Options -> Packages, change the CRAN mirror to "0- Cloud - Rstudio, automatic redirection to servers worldwide"

3- Restart Rstudio.

4- Have fun!

Bootstrap 3 Gutter Size

Bootstrap 3 introduced row-no-gutters in v3.4.0

https://getbootstrap.com/docs/3.4/css/#grid-remove-gutters

You could make a row without gutters, and have a row with gutters inside it for the parts you do want to have a gutter.

How to check if activity is in foreground or in visible background?

I used to do like,

if the activity is not in the foreground

getIntent()

will return null. :=P

PHP Parse error: syntax error, unexpected end of file in a CodeIgniter View

Unexpected end of file means that something else was expected before the PHP parser reached the end of the script.

Judging from your HUGE file, it's probably that you're missing a closing brace (}) from an if statement.

Please at least attempt the following things:

  1. Separate your code from your view logic.
  2. Be consistent, you're using an end ; in some of your embedded PHP statements, and not in others, ie. <?php echo base_url(); ?> vs <?php echo $this->layouts->print_includes() ?>. It's not required, so don't use it (or do, just do one or the other).
  3. Repeated because it's important, separate your concerns. There's no need for all of this code.
  4. Use an IDE, it will help you with errors such as this going forward.

ASP.NET MVC - Attaching an entity of type 'MODELNAME' failed because another entity of the same type already has the same primary key value

i mange to fix the issue by updating state. when you trigger find or any other query operation on the same record sate has been updated with modified so we need to set status to Detached then you can fire your update change

     ActivityEntity activity = new ActivityEntity();
      activity.name="vv";
    activity.ID = 22 ; //sample id
   var savedActivity = context.Activities.Find(22);

            if (savedActivity!=null)
            {
                context.Entry(savedActivity).State = EntityState.Detached;
                context.SaveChanges();

                activity.age= savedActivity.age;
                activity.marks= savedActivity.marks; 

                context.Entry(activity).State = EntityState.Modified;
                context.SaveChanges();
                return activity.ID;
            }

Decimal number regular expression, where digit after decimal is optional

^[+-]?(([1-9][0-9]*)?[0-9](\.[0-9]*)?|\.[0-9]+)$

should reflect what people usually think of as a well formed decimal number.

The digits before the decimal point can be either a single digit, in which case it can be from 0 to 9, or more than one digits, in which case it cannot start with a 0.

If there are any digits present before the decimal sign, then the decimal and the digits following it are optional. Otherwise, a decimal has to be present followed by at least one digit. Note that multiple trailing 0's are allowed after the decimal point.

grep -E '^[+-]?(([1-9][0-9]*)?[0-9](\.[0-9]*)?|\.[0-9]+)$'

correctly matches the following:

9
0
10
10.
0.
0.0
0.100
0.10
0.01
10.0
10.10
.0
.1
.00
.100
.001

as well as their signed equivalents, whereas it rejects the following:

.
00
01
00.0
01.3

and their signed equivalents, as well as the empty string.

How to add pandas data to an existing csv file?

A bit late to the party but you can also use a context manager, if you're opening and closing your file multiple times, or logging data, statistics, etc.

from contextlib import contextmanager
import pandas as pd
@contextmanager
def open_file(path, mode):
     file_to=open(path,mode)
     yield file_to
     file_to.close()


##later
saved_df=pd.DataFrame(data)
with open_file('yourcsv.csv','r') as infile:
      saved_df.to_csv('yourcsv.csv',mode='a',header=False)`

Django: OperationalError No Such Table

Running the following commands solved this for me 1. python manage.py migrate 2. python manage.py makemigrations 3. python manage.py makemigrations appName

Get exit code for command in bash/ksh

Try

safeRunCommand() {
   "$@"

   if [ $? != 0 ]; then
      printf "Error when executing command: '$1'"
      exit $ERROR_CODE
   fi
}

How can I get LINQ to return the object which has the max value for a given property?

try this:

var maxid = from i in items
            group i by i.clientid int g
            select new { id = g.Max(i=>i.ID }

What is the best way to seed a database in Rails?

factory_bot sounds like it will do what you are trying to achieve. You can define all the common attributes in the default definition and then override them at creation time. You can also pass an id to the factory:

Factory.define :theme do |t|
  t.background_color '0x000000'
  t.title_text_color '0x000000',
  t.component_theme_color '0x000000'
  t.carrier_select_color '0x000000'
  t.label_text_color '0x000000',
  t.join_upper_gradient '0x000000'
  t.join_lower_gradient '0x000000'
  t.join_text_color '0x000000',
  t.cancel_link_color '0x000000'
  t.border_color '0x000000'
  t.carrier_text_color '0x000000'
  t.public true
end

Factory(:theme, :id => 1, :name => "Lite", :background_color => '0xC7FFD5')
Factory(:theme, :id => 2, :name => "Metallic", :background_color => '0xC7FFD5')
Factory(:theme, :id => 3, :name => "Blues", :background_color => '0x0060EC')

When used with faker it can populate a database really quickly with associations without having to mess about with Fixtures (yuck).

I have code like this in a rake task.

100.times do
    Factory(:company, :address => Factory(:address), :employees => [Factory(:employee)])
end

Need to find element in selenium by css

Only using class names is not sufficient in your case.

  • By.cssSelector(".ban") has 15 matching nodes
  • By.cssSelector(".hot") has 11 matching nodes
  • By.cssSelector(".ban.hot") has 5 matching nodes

Therefore you need more restrictions to narrow it down. Option 1 and 2 below are available for css selector, 1 might be the one that suits your needs best.

Option 1: Using list items' index (CssSelector or XPath)

Limitations

  • Not stable enough if site's structure changes

Example:

driver.FindElement(By.CssSelector("#rightbar > .menu > li:nth-of-type(3) > h5"));
driver.FindElement(By.XPath("//*[@id='rightbar']/ul/li[3]/h5"));

Option 2: Using Selenium's FindElements, then index them. (CssSelector or XPath)

Limitations

  • Not stable enough if site's structure changes
  • Not the native selector's way

Example:

// note that By.CssSelector(".ban.hot") and //*[contains(@class, 'ban hot')] are different, but doesn't matter in your case
IList<IWebElement> hotBanners = driver.FindElements(By.CssSelector(".ban.hot"));
IWebElement banUsStates = hotBanners[3];

Option 3: Using text (XPath only)

Limitations

  • Not for multilanguage sites
  • Only for XPath, not for Selenium's CssSelector

Example:

driver.FindElement(By.XPath("//h5[contains(@class, 'ban hot') and text() = 'us states']"));

Option 4: Index the grouped selector (XPath only)

Limitations

  • Not stable enough if site's structure changes
  • Only for XPath, not CssSelector

Example:

driver.FindElement(By.XPath("(//h5[contains(@class, 'ban hot')])[3]"));

Option 5: Find the hidden list items link by href, then traverse back to h5 (XPath only)

Limitations

  • Only for XPath, not CssSelector
  • Low performance
  • Tricky XPath

Example:

driver.FindElement(By.XPath(".//li[.//ul/li/a[contains(@href, 'geo.craigslist.org/iso/us/al')]]/h5"));

PHP session lost after redirect

Just for the record... I had this problem and after a few hours of trying everything the problem was that the disk was full, and php sessions could not be written into the tmp directory... so if you have this problem check that too...

mongodb: insert if not exists

As of MongoDB 2.4, you can use $setOnInsert (http://docs.mongodb.org/manual/reference/operator/setOnInsert/)

Set 'insertion_date' using $setOnInsert and 'last_update_date' using $set in your upsert command.

To turn your pseudocode into a working example:

now = datetime.utcnow()
for document in update:
    collection.update_one(
        {"_id": document["_id"]},
        {
            "$setOnInsert": {"insertion_date": now},
            "$set": {"last_update_date": now},
        },
        upsert=True,
    )

javascript multiple OR conditions in IF statement

Each of the three conditions is evaluated independently[1]:

id != 1 // false
id != 2 // true
id != 3 // true

Then it evaluates false || true || true, which is true (a || b is true if either a or b is true). I think you want

id != 1 && id != 2 && id != 3

which is only true if the ID is not 1 AND it's not 2 AND it's not 3.

[1]: This is not strictly true, look up short-circuit evaluation. In reality, only the first two clauses are evaluated because that is all that is necessary to determine the truth value of the expression.

How to show git log history (i.e., all the related commits) for a sub directory of a git repo?

The other answers only show the changed files.

git log -p DIR is very useful, if you need the full diff of all changed files in a specific subdirectory.

Example: Show all detailed changes in a specific version range

git log -p 8a5fb..HEAD -- A B

commit 62ad8c5d
Author: Scott Tiger
Date:   Mon Nov 27 14:25:29 2017 +0100

    My comment

...
@@ -216,6 +216,10 @@ public class MyClass {

+  Added
-  Deleted

PHP string "contains"

PHP 8 or newer:

Use the str_contains function.

if (str_contains($str, "."))
{
    echo 'Found it';
}

else
{
    echo 'Not found.';
}

PHP 7 or older:

if (strpos($str, '.') !== FALSE)
{
    echo 'Found it';
}

else
{
    echo 'Not found.';
}

Note that you need to use the !== operator. If you use != or <> and the '.' is found at position 0, the comparison will evaluate to true because 0 is loosely equal to false.

Xcode5 "No matching provisioning profiles found issue" (but good at xcode4)

All of drop down lists disappeared in Build Settings after running the Fix Issue in Xcode 5. Spent several days trying to figure out what was wrong with my provisioning profiles and code signing. Found a link Xcode 4 missing drop down lists in Build Settings and sure enough I needed to re-enabled "Show Values" under the Editor menu. Hopefully this helps anyone else in this predicament.

Also, I had to clear my derived data, clean the solution and quit and reopen Xcode into for the code signing identities to correctly appear. My distribution provisioning profiles where showing up as signed by my developer certificate which was incorrect.

jQuery Validate Plugin - Trigger validation of single field

in case u wanna do the validation for "some elements" (not all element) on your form.You can use this method:

$('input[name="element-one"], input[name="element-two"], input[name="element-three"]').valid();

Hope it help everybody :)

EDITED

Android WebView Cookie Problem

I have a different approach from other people here, and it an approach that is guaranteed work without dealing with the CookieSyncManager (where you are at the mercy of semantics like "Note that even sync() happens asynchronously").

Essentially, we browse to the correct domain, then we execute javascript from the page context to set cookies for that domain (the same way the page itself would). Two drawbacks to the method are that may introduce an extra round trip time due to the extra http request you have to make; and if your site does not have the equivalent of a blank page, it may flash whatever URL you load first before taking you to the right place.

import org.apache.commons.lang.StringEscapeUtils;
import org.apache.http.cookie.Cookie;
import android.annotation.SuppressLint;
import android.webkit.CookieManager;
import android.webkit.CookieSyncManager;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class WebViewFragment {
    private static final String BLANK_PAGE = "/blank.html"

    private CookieSyncManager mSyncManager;
    private CookieManager mCookieManager;

    private String mTargetUrl;
    private boolean mInitializedCookies;
    private List<Cookie> mAllCookies;

    public WebViewFragment(Context ctx) {
        // We are still required to create an instance of Cookie/SyncManager.
        mSyncManager = CookieSyncManager.createInstance(ctx);
        mCookieManager = CookieManager.getInstance();
    }

    @SuppressLint("SetJavaScriptEnabled") public void loadWebView(
                String url, List<Cookie> cookies, String domain) {
        final WebView webView = ...

        webView.setWebViewClient(new CookeWebViewClient());
        webView.getSettings().setJavaScriptEnabled(true);

        mInitializedCookies = false;
        mTargetUrl = url;
        mAllCookies = cookies;
        // This is where the hack starts.
        // Instead of loading the url, we load a blank page.
        webView.loadUrl("http://" + domain + BLANK_PAGE);
    }

    public static String buildCookieString(final Cookie cookie) {
        // You may want to add the secure flag for https:
        // + "; secure"
        // In case you wish to convert session cookies to have an expiration:
        // + "; expires=Thu, 01-Jan-2037 00:00:10 GMT"
        // Note that you cannot set the HttpOnly flag as we are using
        // javascript to set the cookies.
        return cookie.getName() + "=" + cookie.getValue()
                    + "; path=" + cookie.getPath()
                    + "; domain=" + cookie.getDomain()
    };

    public synchronized String generateCookieJavascript() {
        StringBuilder javascriptCode = new StringBuilder();
        javascriptCode.append("javascript:(function(){");
        for (final Cookie cookie : mAllCookies) {
            String cookieString = buildCookieString(cookie);
            javascriptCode.append("document.cookie=\"");
            javascriptCode.append(
                     StringEscapeUtils.escapeJavascriptString(cookieString));
            javascriptCode.append("\";");
        }
        // We use javascript to load the next url because we do not
        // receive an onPageFinished event when this code finishes.
        javascriptCode.append("document.location=\"");
        javascriptCode.append(
                StringEscapeUtils.escapeJavascriptString(mTargetUrl));
        javascriptCode.append("\";})();");
        return javascriptCode.toString();
    }

    private class CookieWebViewClient extends WebViewClient {
        @Override public void onPageFinished(WebView view, String url) {
            super.onPageFinished(view, url);
            if (!mInitializedCookies) {
                mInitializedCookies = true;
                // Run our javascript code now that the temp page is loaded.
                view.loadUrl(generateCookieJavascript());
                return;
            }
        }
    }
}

If you trust the domain the cookies are from, you may be able to get away without apache commons, but you have to understand that this can present a XSS risk if you are not careful.

How do I use Docker environment variable in ENTRYPOINT array?

You're using the exec form of ENTRYPOINT. Unlike the shell form, the exec form does not invoke a command shell. This means that normal shell processing does not happen. For example, ENTRYPOINT [ "echo", "$HOME" ] will not do variable substitution on $HOME. If you want shell processing then either use the shell form or execute a shell directly, for example: ENTRYPOINT [ "sh", "-c", "echo $HOME" ].
When using the exec form and executing a shell directly, as in the case for the shell form, it is the shell that is doing the environment variable expansion, not docker.(from Dockerfile reference)

In your case, I would use shell form

ENTRYPOINT ./greeting --message "Hello, $ADDRESSEE\!"

Splitting strings using a delimiter in python

So, your input is 'dan|warrior|54' and you want "warrior". You do this like so:

>>> dan = 'dan|warrior|54'
>>> dan.split('|')[1]
"warrior"

Transfer data from one HTML file to another

<html>
<head>
<script language="javascript" type="text/javascript" scr="asd.js"></script>
</head>

<body>

<form name="form1" action="#" method="get">
name:<input type ="text" id="name" name="n">
<input type="submit" value="next" >
<button type="button" id="print" onClick="testJS()"> Print </button>
</form>

</body>

client side scripting

function testJS(){
var name = jQuery("#name").val();
jQuery.load("next.html",function(){
jQuery("#here").html(name);
});
}

jQuery is a js library and it simplifies its programming. So I recommend to use jQuery rathar then js. Here I just took value of input elemnt(id = name) on submit button click event ,then loaded the desired page(next.html), if the load function executes successfully i am calling a function which will put the data in desired place.

jquery load function http://api.jquery.com/load/

Getting all types that implement an interface

Other answer were not working with a generic interface.

This one does, just replace typeof(ISomeInterface) by typeof (T).

List<string> types = AppDomain.CurrentDomain.GetAssemblies().SelectMany(x => x.GetTypes())
            .Where(x => typeof(ISomeInterface).IsAssignableFrom(x) && !x.IsInterface && !x.IsAbstract)
            .Select(x => x.Name).ToList();

So with

AppDomain.CurrentDomain.GetAssemblies().SelectMany(x => x.GetTypes())

we get all the assemblies

!x.IsInterface && !x.IsAbstract

is used to exclude the interface and abstract ones and

.Select(x => x.Name).ToList();

to have them in a list.

Using the "animated circle" in an ImageView while loading stuff

For the ones developing in Kotlin, there is a sweet method provided by the Anko library that makes the process of displaying a ProgressDialog a breeze!

Based on that link:

val dialog = progressDialog(message = "Please wait a bit…", title = "Fetching data")
dialog.show()
//....
dialog.dismiss()

This will show a Progress Dialog with the progress % displayed (for which you have to pass the init parameter also to calculate the progress).

There is also the indeterminateProgressDialog() method, which provides the Spinning Circle animation indefinitely until dismissed:

indeterminateProgressDialog("Loading...").show()

Shout out to this blog which led me to this solution.

Convert List(of object) to List(of string)

No - if you want to convert ALL elements of a list, you'll have to touch ALL elements of that list one way or another.

You can specify / write the iteration in different ways (foreach()......, or .ConvertAll() or whatever), but in the end, one way or another, some code is going to iterate over each and every element and convert it.

Marc

ValueError: Length of values does not match length of index | Pandas DataFrame.unique()

The error comes up when you are trying to assign a list of numpy array of different length to a data frame, and it can be reproduced as follows:

A data frame of four rows:

df = pd.DataFrame({'A': [1,2,3,4]})

Now trying to assign a list/array of two elements to it:

df['B'] = [3,4]   # or df['B'] = np.array([3,4])

Both errors out:

ValueError: Length of values does not match length of index

Because the data frame has four rows but the list and array has only two elements.

Work around Solution (use with caution): convert the list/array to a pandas Series, and then when you do assignment, missing index in the Series will be filled with NaN:

df['B'] = pd.Series([3,4])

df
#   A     B
#0  1   3.0
#1  2   4.0
#2  3   NaN          # NaN because the value at index 2 and 3 doesn't exist in the Series
#3  4   NaN

For your specific problem, if you don't care about the index or the correspondence of values between columns, you can reset index for each column after dropping the duplicates:

df.apply(lambda col: col.drop_duplicates().reset_index(drop=True))

#   A     B
#0  1   1.0
#1  2   5.0
#2  7   9.0
#3  8   NaN

Is it possible to apply CSS to half of a character?

Closest I can get:

_x000D_
_x000D_
$(function(){_x000D_
  $('span').width($('span').width()/2);_x000D_
  $('span:nth-child(2)').css('text-indent', -$('span').width());_x000D_
});
_x000D_
body{_x000D_
  font-family: arial;_x000D_
}_x000D_
span{_x000D_
  display: inline-block;_x000D_
  overflow: hidden;_x000D_
}_x000D_
span:nth-child(2){_x000D_
  color: red;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<span>X</span><span>X</span>
_x000D_
_x000D_
_x000D_

Demo: http://jsfiddle.net/9wxfY/2/

Heres a version that just uses one span: http://jsfiddle.net/9wxfY/4/

How to Scroll Down - JQuery

If you want to scroll down to the div (id="div1"). Then you can use this code.

 $('html, body').animate({
     scrollTop: $("#div1").offset().top
 }, 1500);

Could not find method android() for arguments

guys. I had the same problem before when I'm trying import a .aar package into my project, and unfortunately before make the .aar package as a module-dependence of my project, I had two modules (one about ROS-ANDROID-CV-BRIDGE, one is OPENCV-FOR-ANDROID) already. So, I got this error as you guys meet:

Error:Could not find method android() for arguments [org.ros.gradle_plugins.RosAndroidPlugin$_apply_closure2_closure4@7e550e0e] on project ‘:xxx’ of type org.gradle.api.Project.

So, it's the painful gradle-structure caused this problem when you have several modules in your project, and worse, they're imported in different way or have different types (.jar/.aar packages or just a project of Java library). And it's really a headache matter to make the configuration like compile-version, library dependencies etc. in each subproject compatible with the main-project.

I solved my problem just follow this steps:

? Copy .aar package in app/libs.

? Add this in app/build.gradle file:

repositories {
    flatDir {
        dirs 'libs' //this way we can find the .aar file in libs folder
    }
}

? Add this in your add build.gradle file of the module which you want to apply the .aar dependence (in my situation, just add this in my app/build.gradle file):

dependencies {
    compile(name:'package_name', ext:'aar')
}

So, if it's possible, just try export your module-dependence as a .aar package, and then follow this way import it to your main-project. Anyway, I hope this can be a good suggestion and would solve your problem if you have the same situation with me.

Can I send a ctrl-C (SIGINT) to an application on Windows?

Somehow GenerateConsoleCtrlEvent() return error if you call it for another process, but you can attach to another console application and send event to all child processes.

void SendControlC(int pid)
{
    AttachConsole(pid); // attach to process console
    SetConsoleCtrlHandler(NULL, TRUE); // disable Control+C handling for our app
    GenerateConsoleCtrlEvent(CTRL_C_EVENT, 0); // generate Control+C event
}

Oracle SQL Developer spool output?

I was trying things to duplicate the spools you get from sqlplus. I found the following and hope it helps:

Create your sql script file ie:

Please note the echo and serveroutput.

Test_Spool.SQL

Spool 'c:\temp\Test1.txt';
set echo on;
set serveroutput on;
declare
sqlresult varchar2(60);

begin
  select to_char(sysdate,'YYYY-MM-DD HH24:MI:SS') into sqlresult from dual;
  dbms_output.put_line('The date is ' || sqlresult);
end;

/

Spool off;
set serveroutput off;
set echo off;

Run the script from another worksheet:

@TEST_Spool.SQL

My output from the Test1.txt

set serveroutput on
declare
sqlresult varchar2(60);

begin
  select to_char(sysdate,'YYYY-MM-DD HH24:MI:SS') into sqlresult from dual;
  dbms_output.put_line('The date is ' || sqlresult);
end;

anonymous block completed

The date is 2016-04-07 09:21:32

Spool of

How to use multiple @RequestMapping annotations in spring?

@RequestMapping has a String[] value parameter, so you should be able to specify multiple values like this:

@RequestMapping(value={"", "/", "welcome"})

How to convert a date String to a Date or Calendar object?

The highly regarded Joda Time library is also worth a look. This is basis for the new date and time api that is pencilled in for Java 7. The design is neat, intuitive, well documented and avoids a lot of the clumsiness of the original java.util.Date / java.util.Calendar classes.

Joda's DateFormatter can parse a String to a Joda DateTime.

How do I activate C++ 11 in CMake?

The easiest way:

add_compile_options(-std=c++11)

jQuery.css() - marginLeft vs. margin-left?

Hi i tried this it is working.

$("#change_align").css({"margin-top":"-39px","margin-right":"0px","margin-bottom":"0px","margin-left":"719px"});

how does array[100] = {0} set the entire array to 0?

It depends where you put this initialisation.

If the array is static as in

char array[100] = {0};

int main(void)
{
...
}

then it is the compiler that reserves the 100 0 bytes in the data segement of the program. In this case you could have omitted the initialiser.

If your array is auto, then it is another story.

int foo(void)
{
char array[100] = {0};
...
}

In this case at every call of the function foo you will have a hidden memset.

The code above is equivalent to

int foo(void)
{ 
char array[100];

memset(array, 0, sizeof(array));
....
}

and if you omit the initializer your array will contain random data (the data of the stack).

If your local array is declared static like in

int foo(void)
{ 
static char array[100] = {0};
...
}

then it is technically the same case as the first one.

fatal: could not create work tree dir 'kivy'

I had the same error on Debian and all I had to do was:

sudo su

and then run the command again and it worked.

Bootstrap full-width text-input within inline-form

As stated in a similar question, try removing instances of the input-group class and see if that helps.

refering to bootstrap:

Individual form controls automatically receive some global styling. All textual , , and elements with .form-control are set to width: 100%; by default. Wrap labels and controls in .form-group for optimum spacing.

C++ STL Vectors: Get iterator from index?

way mentioned by @dirkgently ( v.begin() + index ) nice and fast for vectors

but std::advance( v.begin(), index ) most generic way and for random access iterators works constant time too.

EDIT
differences in usage:

std::vector<>::iterator it = ( v.begin() + index );

or

std::vector<>::iterator it = v.begin();
std::advance( it, index );

added after @litb notes.

How do I run a spring boot executable jar in a Production environment?

My Spring boot application has two initializers. One for development and another for production. For development, I use the main method like this:

@SpringBootApplication
public class MyAppInitializer {

    public static void main(String[] args) {
        SpringApplication.run(MyAppInitializer .class, args);
    }

}

My Initializer for production environment extends the SpringBootServletInitializer and looks like this:

@SpringBootApplication
public class MyAppInitializerServlet extends SpringBootServletInitializer{
    private static final Logger log = Logger
            .getLogger(SpringBootServletInitializer.class);
    @Override
    protected SpringApplicationBuilder configure(
            SpringApplicationBuilder builder) {
        log.trace("Initializing the application");
        return builder.sources(MyAppInitializerServlet .class);
    }

}

I use gradle and my build.gradle file applies 'WAR' plugin. When I run it in the development environment, I use bootrun task. Where as when I want to deploy it to production, I use assemble task to generate the WAR and deploy.

I can run like a normal spring application in production without discounting the advantages provided by the inbuilt tomcat while developing. Hope this helps.

Failed to execute 'postMessage' on 'DOMWindow': https://www.youtube.com !== http://localhost:9000

Just wishing to avoid the console error, I solved this using a similar approach to Artur's earlier answer, following these steps:

  1. Downloaded the YouTube Iframe API (from https://www.youtube.com/iframe_api) to a local yt-api.js file.
  2. Removed the code which inserted the www-widgetapi.js script.
  3. Downloaded the www-widgetapi.js script (from https://s.ytimg.com/yts/jsbin/www-widgetapi-vfl7VfO1r/www-widgetapi.js) to a local www-widgetapi.js file.
  4. Replaced the targetOrigin argument in the postMessage call which was causing the error in the console, with a "*" (indicating no preference - see https://developer.mozilla.org/en-US/docs/Web/API/Window/postMessage).
  5. Appended the modified www-widgetapi.js script to the end of the yt-api.js script.

This is not the greatest solution (patched local script to maintain, losing control of where messages are sent) but it solved my issue.

Please see the security warning about removing the targetOrigin URI stated here before using this solution - https://developer.mozilla.org/en-US/docs/Web/API/Window/postMessage

Patched yt-api.js example

Java 6 Unsupported major.minor version 51.0

I face the same problem and solved by adding the JAVA_HOME variable with updated version of java in my Ubuntu Machine(16.04). if you are using "Apache Maven 3.3.9" You need to upgrade your JAVA_HOME with java7 or more

Step to Do this

1-sudo vim /etc/environment

2-JAVA_HOME=JAVA Installation Directory (MyCase-/opt/dev/jdk1.7.0_45/)

3-Run echo $JAVA_HOME will give the JAVA_HOME set value

4-Now mvn -version will give the desired output

Apache Maven 3.3.9

Maven home: /usr/share/maven

Java version: 1.7.0_45, vendor: Oracle Corporation

Java home: /opt/dev/jdk1.7.0_45/jre

Default locale: en_US, platform encoding: UTF-8

OS name: "linux", version: "4.4.0-36-generic", arch: "amd64", family: "unix"

How to convert DateTime? to DateTime

You want to use the null-coalescing operator, which is designed for exactly this purpose.

Using it you end up with this code.

DateTime UpdatedTime = _objHotelPackageOrder.UpdatedDate ?? DateTime.Now;

How to set the size of button in HTML

This cannot be done with pure HTML/JS, you will need CSS

CSS:

button {
     width: 100%;
     height: 100%;
}

Substitute 100% with required size

This can be done in many ways

How to pass password automatically for rsync SSH command?

Though you've already implemented it by now,

you can also use any expect implementation (you'll find alternatives in Perl, Python: pexpect, paramiko, etc..)

500.19 - Internal Server Error - The requested page cannot be accessed because the related configuration data for the page is invalid

In my case, Server had lower version framework than your application. installed latest version framework and it fixed this issue.

How can I count occurrences with groupBy?

Here is the simple solution by StreamEx:

StreamEx.of(list).groupingBy(Function.identity(), MoreCollectors.countingInt());

This has the advantage of reducing the Java stream boilerplate code: collect(Collectors.

Getting MAC Address

For Linux you can retrieve the MAC address using a SIOCGIFHWADDR ioctl.

struct ifreq    ifr;
uint8_t         macaddr[6];

if ((s = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP)) < 0)
    return -1;

strcpy(ifr.ifr_name, "eth0");

if (ioctl(s, SIOCGIFHWADDR, (void *)&ifr) == 0) {
    if (ifr.ifr_hwaddr.sa_family == ARPHRD_ETHER) {
        memcpy(macaddr, ifr.ifr_hwaddr.sa_data, 6);
        return 0;
... etc ...

You've tagged the question "python". I don't know of an existing Python module to get this information. You could use ctypes to call the ioctl directly.

Pick any kind of file via an Intent in Android

Not for camera but for other files..

In my device I have ES File Explorer installed and This simply thing works in my case..

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("file/*");
startActivityForResult(intent, PICKFILE_REQUEST_CODE);

surface plots in matplotlib

This is not a general solution but might help many of those who just typed "matplotlib surface plot" in Google and landed here.

Suppose you have data = [(x1,y1,z1),(x2,y2,z2),.....,(xn,yn,zn)], then you can get three 1-d lists using x, y, z = zip(*data). Now you can of course create 3d scatterplot using three 1-d lists.

But, why can't in general this data be used to create surface plot? To understand that consider an empty 3-d plot :

Now, suppose for each possible value of (x, y) on a "discrete" regular grid, you have a z value, then there's no issue & you can in fact get a surface plot:

import numpy as np
from matplotlib import pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
from matplotlib import cm

x = np.linspace(0, 10, 6)  # [0, 2,..,10] : 6 distinct values
y = np.linspace(0, 20, 5)  # [0, 5,..,20] : 5 distinct values
z = np.linspace(0, 100, 30)  # 6 * 5 = 30 values, 1 for each possible combination of (x,y)

X, Y = np.meshgrid(x, y)
Z = np.reshape(z, X.shape)  # Z.shape must be equal to X.shape = Y.shape

fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')

ax.plot_surface(X, Y, Z)

ax.set_xlabel('X Label')
ax.set_ylabel('Y Label')
ax.set_zlabel('Z Label')
plt.show()

What's happens when you haven't got z for all possible combinations of (x, y)? Then at the point (at intersection of two black lines on x-y plane on blank plot above), we don't know what is the value of z. It could be anything, we don't know how 'high' or 'low' our surface should be at that point (although it can be approximated using other functions, surface_plot requires that you supply it arguments where X.shape = Y.shape = Z.shape).

How to change the Title of the window in Qt?

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.setWindowTitle("Main Page");
    w.show();
    return a.exec();
}

enter image description here

How is CountDownLatch used in Java Multithreading?

NikolaB explained it very well, However example would be helpful to understand, So here is one simple example...

 import java.util.concurrent.*;


  public class CountDownLatchExample {

  public static class ProcessThread implements Runnable {

    CountDownLatch latch;
    long workDuration;
    String name;

    public ProcessThread(String name, CountDownLatch latch, long duration){
        this.name= name;
        this.latch = latch;
        this.workDuration = duration;
    }


    public void run() {
        try {
            System.out.println(name +" Processing Something for "+ workDuration/1000 + " Seconds");
            Thread.sleep(workDuration);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(name+ "completed its works");
        //when task finished.. count down the latch count...

        // basically this is same as calling lock object notify(), and object here is latch
        latch.countDown();
    }
}


public static void main(String[] args) {
    // Parent thread creating a latch object
    CountDownLatch latch = new CountDownLatch(3);

    new Thread(new ProcessThread("Worker1",latch, 2000)).start(); // time in millis.. 2 secs
    new Thread(new ProcessThread("Worker2",latch, 6000)).start();//6 secs
    new Thread(new ProcessThread("Worker3",latch, 4000)).start();//4 secs


    System.out.println("waiting for Children processes to complete....");
    try {
        //current thread will get notified if all chidren's are done 
        // and thread will resume from wait() mode.
        latch.await();
    } catch (InterruptedException e) {
        e.printStackTrace();
    }

    System.out.println("All Process Completed....");

    System.out.println("Parent Thread Resuming work....");



     }
  }

How to consume a SOAP web service in Java

As some sugested you can use apache or jax-ws. You can also use tools that generate code from WSDL such as ws-import but in my opinion the best way to consume web service is to create a dynamic client and invoke only operations you want not everything from wsdl. You can do this by creating a dynamic client: Sample code:

String endpointUrl = ...;

QName serviceName = new QName("http://com/ibm/was/wssample/echo/",
 "EchoService");
QName portName = new QName("http://com/ibm/was/wssample/echo/",
 "EchoServicePort");

/** Create a service and add at least one port to it. **/ 
Service service = Service.create(serviceName);
service.addPort(portName, SOAPBinding.SOAP11HTTP_BINDING, endpointUrl);

/** Create a Dispatch instance from a service.**/ 
Dispatch<SOAPMessage> dispatch = service.createDispatch(portName, 
SOAPMessage.class, Service.Mode.MESSAGE);

/** Create SOAPMessage request. **/
// compose a request message
MessageFactory mf = MessageFactory.newInstance(SOAPConstants.SOAP_1_1_PROTOCOL);

// Create a message.  This example works with the SOAPPART.
SOAPMessage request = mf.createMessage();
SOAPPart part = request.getSOAPPart();

// Obtain the SOAPEnvelope and header and body elements.
SOAPEnvelope env = part.getEnvelope();
SOAPHeader header = env.getHeader();
SOAPBody body = env.getBody();

// Construct the message payload.
SOAPElement operation = body.addChildElement("invoke", "ns1",
 "http://com/ibm/was/wssample/echo/");
SOAPElement value = operation.addChildElement("arg0");
value.addTextNode("ping");
request.saveChanges();

/** Invoke the service endpoint. **/
SOAPMessage response = dispatch.invoke(request);

/** Process the response. **/

How to create number input field in Flutter?

U can Install package intl_phone_number_input

dependencies:
  intl_phone_number_input: ^0.5.2+2

and try this code:

import 'package:flutter/material.dart';
import 'package:intl_phone_number_input/intl_phone_number_input.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    var darkTheme = ThemeData.dark().copyWith(primaryColor: Colors.blue);

    return MaterialApp(
      title: 'Demo',
      themeMode: ThemeMode.dark,
      darkTheme: darkTheme,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: Scaffold(
        appBar: AppBar(title: Text('Demo')),
        body: MyHomePage(),
      ),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final GlobalKey<FormState> formKey = GlobalKey<FormState>();

  final TextEditingController controller = TextEditingController();
  String initialCountry = 'NG';
  PhoneNumber number = PhoneNumber(isoCode: 'NG');

  @override
  Widget build(BuildContext context) {
    return Form(
      key: formKey,
      child: Container(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            InternationalPhoneNumberInput(
              onInputChanged: (PhoneNumber number) {
                print(number.phoneNumber);
              },
              onInputValidated: (bool value) {
                print(value);
              },
              selectorConfig: SelectorConfig(
                selectorType: PhoneInputSelectorType.BOTTOM_SHEET,
                backgroundColor: Colors.black,
              ),
              ignoreBlank: false,
              autoValidateMode: AutovalidateMode.disabled,
              selectorTextStyle: TextStyle(color: Colors.black),
              initialValue: number,
              textFieldController: controller,
              inputBorder: OutlineInputBorder(),
            ),
            RaisedButton(
              onPressed: () {
                formKey.currentState.validate();
              },
              child: Text('Validate'),
            ),
            RaisedButton(
              onPressed: () {
                getPhoneNumber('+15417543010');
              },
              child: Text('Update'),
            ),
          ],
        ),
      ),
    );
  }

  void getPhoneNumber(String phoneNumber) async {
    PhoneNumber number =
        await PhoneNumber.getRegionInfoFromPhoneNumber(phoneNumber, 'US');

    setState(() {
      this.number = number;
    });
  }

  @override
  void dispose() {
    controller?.dispose();
    super.dispose();
  }
}

image:

The EXECUTE permission was denied on the object 'xxxxxxx', database 'zzzzzzz', schema 'dbo'

here is how to give permission for one user not public,

Direct Query:

Use MyDatabase Grant execute on [dbo].[My-procedures-name] to [IIS APPPOOL\my-iis-pool] Go

jQuery append text inside of an existing paragraph tag

If you want to append text or html to span then you can do it as below.

$('p span#add_here').append('text goes here');

append will add text to span tag at the end.

to replace entire text or html inside of span you can use .text() or .html()

In Python, is there an elegant way to print a list in a custom format without explicit looping?

>>> lst = [1, 2, 3]
>>> print('\n'.join('{}: {}'.format(*k) for k in enumerate(lst)))
0: 1
1: 2
2: 3

Note: you just need to understand that list comprehension or iterating over a generator expression is explicit looping.

ToggleButton in C# WinForms

You can just use a CheckBox and set its appearance to Button:

CheckBox checkBox = new System.Windows.Forms.CheckBox(); 
checkBox.Appearance = System.Windows.Forms.Appearance.Button; 

Meaning of "[: too many arguments" error from if [] (square brackets)

If your $VARIABLE is a string containing spaces or other special characters, and single square brackets are used (which is a shortcut for the test command), then the string may be split out into multiple words. Each of these is treated as a separate argument.

So that one variable is split out into many arguments:

VARIABLE=$(/some/command);  
# returns "hello world"

if [ $VARIABLE == 0 ]; then
  # fails as if you wrote:
  # if [ hello world == 0 ]
fi 

The same will be true for any function call that puts down a string containing spaces or other special characters.


Easy fix

Wrap the variable output in double quotes, forcing it to stay as one string (therefore one argument). For example,

VARIABLE=$(/some/command);
if [ "$VARIABLE" == 0 ]; then
  # some action
fi 

Simple as that. But skip to "Also beware..." below if you also can't guarantee your variable won't be an empty string, or a string that contains nothing but whitespace.


Or, an alternate fix is to use double square brackets (which is a shortcut for the new test command).

This exists only in bash (and apparently korn and zsh) however, and so may not be compatible with default shells called by /bin/sh etc.

This means on some systems, it might work from the console but not when called elsewhere, like from cron, depending on how everything is configured.

It would look like this:

VARIABLE=$(/some/command);
if [[ $VARIABLE == 0 ]]; then
  # some action
fi 

If your command contains double square brackets like this and you get errors in logs but it works from the console, try swapping out the [[ for an alternative suggested here, or, ensure that whatever runs your script uses a shell that supports [[ aka new test.


Also beware of the [: unary operator expected error

If you're seeing the "too many arguments" error, chances are you're getting a string from a function with unpredictable output. If it's also possible to get an empty string (or all whitespace string), this would be treated as zero arguments even with the above "quick fix", and would fail with [: unary operator expected

It's the same 'gotcha' if you're used to other languages - you don't expect the contents of a variable to be effectively printed into the code like this before it is evaluated.

Here's an example that prevents both the [: too many arguments and the [: unary operator expected errors: replacing the output with a default value if it is empty (in this example, 0), with double quotes wrapped around the whole thing:

VARIABLE=$(/some/command);
if [ "${VARIABLE:-0}" == 0 ]; then
  # some action
fi 

(here, the action will happen if $VARIABLE is 0, or empty. Naturally, you should change the 0 (the default value) to a different default value if different behaviour is wanted)


Final note: Since [ is a shortcut for test, all the above is also true for the error test: too many arguments (and also test: unary operator expected)

macro run-time error '9': subscript out of range

When you get the error message, you have the option to click on "Debug": this will lead you to the line where the error occurred. The Dark Canuck seems to be right, and I guess the error occurs on the line:

Sheets("Sheet1").protect Password:="btfd"

because most probably the "Sheet1" does not exist. However, if you say "It works fine, but when I save the file I get the message: run-time error '9': subscription out of range" it makes me think the error occurs on the second line:

ActiveWorkbook.Save

Could you please check this by pressing the Debug button first? And most important, as Gordon Bell says, why are you using a macro to protect a workbook?

How to disable gradle 'offline mode' in android studio?

Gradle is in offline mode, which means that it won't go to the network to resolve dependencies.

Go to Preferences > Gradle and uncheck "Offline work".

How to undo 'git reset'?

1.Use git reflog to get all references update.

2.git reset <id_of_commit_to_which_you_want_restore>

How to set Spinner default value to null?

Merge this:

private long previousItemId = 0;

@Override
public long getItemId(int position) {
    long nextItemId = random.nextInt(Integer.MAX_VALUE);
    while(previousItemId == nextItemId) {
        nextItemId = random.nextInt(Integer.MAX_VALUE);
    }
    previousItemId = nextItemId;
    return nextItemId;
}

With this answer:

public class SpinnerInteractionListener
        implements AdapterView.OnItemSelectedListener, View.OnTouchListener {

    private AdapterView.OnItemSelectedListener onItemSelectedListener;

    public SpinnerInteractionListener(AdapterView.OnItemSelectedListener selectedListener) {
        this.onItemSelectedListener = selectedListener;
    }

    boolean userSelect = false;

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        userSelect = true;
        return false;
    }

    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
        if(userSelect) {
            onItemSelectedListener.onItemSelected(parent, view, pos, id);
            userSelect = false;
        }
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {
        if(userSelect) {
            onItemSelectedListener.onNothingSelected(parent);
            userSelect = false;
        }
    }
}

Only allow specific characters in textbox

    private void txtuser_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (!char.IsLetter(e.KeyChar) && !char.IsWhiteSpace(e.KeyChar) && !char.IsControl(e.KeyChar))
        {
            e.Handled = true;
        }
    }

Write a file in UTF-8 using FileWriter (Java)?

OK it's 2019 now, and from Java 11 you have a constructor with Charset:

FileWriter?(String fileName, Charset charset)

Unfortunately, we still cannot modify the byte buffer size, and it's set to 8192. (https://www.baeldung.com/java-filewriter)

How to downgrade from Internet Explorer 11 to Internet Explorer 10?

  1. Go to Control Panel -> Programs -> Programs and features

    Step 1 - Programs and features

  2. Go to Windows Features and disable Internet Explorer 11

    Step 2 - Windows Features

    Step 3 - Uncheck Internet Explorer 11

  3. Then click on Display installed updates

    Step 4 - Display installed updates

  4. Search for Internet explorer

  5. Right-click on Internet Explorer 11 -> Uninstall

    Step 5 - Uninstall Internet Explorer 11

  6. Do the same with Internet Explorer 10

  7. Restart your computer
  8. Install Internet Explorer 10 here (old broken link)

I think it will be okay.

Add Expires headers

You can add them in your htaccess file or vhost configuration.

See here : http://httpd.apache.org/docs/2.2/mod/mod_expires.html

But unless you own those domains .. they are our of your control.

How to add Date Picker Bootstrap 3 on MVC 5 project using the Razor engine?

This answer uses the jQuery UI Datepicker, which is a separate include. There are other ways to do this without including jQuery UI.

First, you simply need to add the datepicker class to the textbox, in addition to form-control:

<div class="form-group input-group-sm">
    @Html.LabelFor(model => model.DropOffDate)
    @Html.TextBoxFor(model => model.DropOffDate, new { @class = "form-control datepicker", placeholder = "Enter Drop-off date here..." })
    @Html.ValidationMessageFor(model => model.DropOffDate)
</div>

Then, to be sure the javascript is triggered after the textbox is rendered, you have to put the datepicker call in the jQuery ready function:

<script type="text/javascript">
    $(function () { // will trigger when the document is ready
       $('.datepicker').datepicker(); //Initialise any date pickers
    });
</script>

Install numpy on python3.3 - Install pip for python3

My issue was the failure to import numpy into my python files. I was receiving the "ModuleNotFoundError: No module named 'numpy'". I ran into the same issue and I was not referencing python3 on the installation of numpy. I inputted the following into my terminal for OSX and my problems were solved:

python3 -m pip install numpy

CURL alternative in Python

Some example, how to use urllib for that things, with some sugar syntax. I know about requests and other libraries, but urllib is standard lib for python and doesn't require anything to be installed separately.

Python 2/3 compatible.

import sys
if sys.version_info.major == 3:
  from urllib.request import HTTPPasswordMgrWithDefaultRealm, HTTPBasicAuthHandler, Request, build_opener
  from urllib.parse import urlencode
else:
  from urllib2 import HTTPPasswordMgrWithDefaultRealm, HTTPBasicAuthHandler, Request, build_opener
  from urllib import urlencode


def curl(url, params=None, auth=None, req_type="GET", data=None, headers=None):
  post_req = ["POST", "PUT"]
  get_req = ["GET", "DELETE"]

  if params is not None:
    url += "?" + urlencode(params)

  if req_type not in post_req + get_req:
    raise IOError("Wrong request type \"%s\" passed" % req_type)

  _headers = {}
  handler_chain = []

  if auth is not None:
    manager = HTTPPasswordMgrWithDefaultRealm()
    manager.add_password(None, url, auth["user"], auth["pass"])
    handler_chain.append(HTTPBasicAuthHandler(manager))

  if req_type in post_req and data is not None:
    _headers["Content-Length"] = len(data)

  if headers is not None:
    _headers.update(headers)

  director = build_opener(*handler_chain)

  if req_type in post_req:
    if sys.version_info.major == 3:
      _data = bytes(data, encoding='utf8')
    else:
      _data = bytes(data)

    req = Request(url, headers=_headers, data=_data)
  else:
    req = Request(url, headers=_headers)

  req.get_method = lambda: req_type
  result = director.open(req)

  return {
    "httpcode": result.code,
    "headers": result.info(),
    "content": result.read()
  }


"""
Usage example:
"""

Post data:
  curl("http://127.0.0.1/", req_type="POST", data='cascac')

Pass arguments (http://127.0.0.1/?q=show):
  curl("http://127.0.0.1/", params={'q': 'show'}, req_type="POST", data='cascac')

HTTP Authorization:
  curl("http://127.0.0.1/secure_data.txt", auth={"user": "username", "pass": "password"})

Function is not complete and possibly is not ideal, but shows a basic representation and concept to use. Additional things could be added or changed by taste.

12/08 update

Here is a GitHub link to live updated source. Currently supporting:

  • authorization

  • CRUD compatible

  • automatic charset detection

  • automatic encoding(compression) detection

How to access command line arguments of the caller inside a function?

You can use the shift keyword (operator?) to iterate through them. Example:

#!/bin/bash
function print()
{
    while [ $# -gt 0 ]
    do
        echo $1;
        shift 1;
    done
}
print $*;

HTML span align center not working?

On top of all the other explanations, I believe you're using equal "=" sign, instead of colon ":":

<span style="border:1px solid red;text-align=center">

It should be:

<span style="border:1px solid red;text-align:center">

How do I set up HttpContent for my HttpClient PostAsync second parameter?

To add to Preston's answer, here's the complete list of the HttpContent derived classes available in the standard library:

Credit: https://pfelix.wordpress.com/2012/01/16/the-new-system-net-http-classes-message-content/

Credit: https://pfelix.wordpress.com/2012/01/16/the-new-system-net-http-classes-message-content/

There's also a supposed ObjectContent but I was unable to find it in ASP.NET Core.

Of course, you could skip the whole HttpContent thing all together with Microsoft.AspNet.WebApi.Client extensions (you'll have to do an import to get it to work in ASP.NET Core for now: https://github.com/aspnet/Home/issues/1558) and then you can do things like:

var response = await client.PostAsJsonAsync("AddNewArticle", new Article
{
    Title = "New Article Title",
    Body = "New Article Body"
});

Remove an array element and shift the remaining ones

You can't achieve what you want with arrays. Use vectors instead, and read about the std::remove algorithm. Something like:

std::remove(array, array+5, 3)

will work on your array, but it will not shorten it (why -- because it's impossible). With vectors, it'd be something like

v.erase(std::remove(v.begin(), v.end(), 3), v.end())

git push rejected

If push request is shows Rejected, then try first pull from your github account and then try push.

Ex:

In my case it was giving an error-

 ! [rejected]        master -> master (fetch first)
error: failed to push some refs to 'https://github.com/ashif8984/git-github.git'
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

****So what I did was-****

$ git pull
$ git push

And the code was pushed successfully into my Github Account.

Parsing JSON from URL

public static TargetClassJson downloadPaletteJson(String url) throws IOException {
        if (StringUtils.isBlank(url)) {
            return null;
        }
        String genreJson = IOUtils.toString(new URL(url).openStream());
        return new Gson().fromJson(genreJson, TargetClassJson.class);
    }

How to convert array values to lowercase in PHP?

Just for completeness: you may also use array_walk:

array_walk($yourArray, function(&$value)
{
  $value = strtolower($value);
});

From PHP docs:

If callback needs to be working with the actual values of the array, specify the first parameter of callback as a reference. Then, any changes made to those elements will be made in the original array itself.

Or directly via foreach loop using references:

foreach($yourArray as &$value)
  $value = strtolower($value);

Note that these two methods change the array "in place", whereas array_map creates and returns a copy of the array, which may not be desirable in case of very large arrays.

How to delete rows in tables that contain foreign keys to other tables

You can alter a foreign key constraint with delete cascade option as shown below. This will delete chind table rows related to master table rows when deleted.

ALTER TABLE MasterTable
ADD CONSTRAINT fk_xyz 
FOREIGN KEY (xyz) 
REFERENCES ChildTable (xyz) ON DELETE CASCADE