Programs & Examples On #Dynamically generated co

Can I get Unix's pthread.h to compile in Windows?

As @Ninefingers mentioned, pthreads are unix-only. Posix only, really.

That said, Microsoft does have a library that duplicates pthreads:

Microsoft Windows Services for UNIX Version 3.5

Library Download

How to disable clicking inside div

How to disable clicking another div click until first one popup div close

Image of the example

 <p class="btn1">One</p>
 <div id="box1" class="popup">
 Test Popup Box One
 <span class="close">X</span>
 </div>

 <!-- Two -->
 <p class="btn2">Two</p>
 <div id="box2" class="popup">
 Test Popup Box Two
 <span class="close">X</span>
  </div>

<style>
.disabledbutton {
 pointer-events: none;
 }

.close {
cursor: pointer;
}

</style>
<script>
$(document).ready(function(){
//One
$(".btn1").click(function(){
  $("#box1").css('display','block');
  $(".btn2,.btn3").addClass("disabledbutton");

});
$(".close").click(function(){
  $("#box1").css('display','none');
  $(".btn2,.btn3").removeClass("disabledbutton");
});
</script>

What's the C# equivalent to the With statement in VB?

The closest thing in C# 3.0, is that you can use a constructor to initialize properties:

Stuff.Elements.Foo foo = new Stuff.Elements.Foo() {Name = "Bob Dylan", Age = 68, Location = "On Tour", IsCool = true}

How can I add a .npmrc file?

There are a few different points here:

  1. Where is the .npmrc file created.
  2. How can you download private packages

Running npm config ls -l will show you all the implicit settings for npm, including what it thinks is the right place to put the .npmrc. But if you have never logged in (using npm login) it will be empty. Simply log in to create it.

Another thing is #2. You can actually do that by putting a .npmrc file in the NPM package's root. It will then be used by NPM when authenticating. It also supports variable interpolation from your shell so you could do stuff like this:

; Get the auth token to use for fetching private packages from our private scope
; see http://blog.npmjs.org/post/118393368555/deploying-with-npm-private-modules
; and also https://docs.npmjs.com/files/npmrc
//registry.npmjs.org/:_authToken=${NPM_TOKEN}

Pointers

How to use the unsigned Integer in Java 8 and Java 9?

    // Java 8
    int vInt = Integer.parseUnsignedInt("4294967295");
    System.out.println(vInt); // -1
    String sInt = Integer.toUnsignedString(vInt);
    System.out.println(sInt); // 4294967295

    long vLong = Long.parseUnsignedLong("18446744073709551615");
    System.out.println(vLong); // -1
    String sLong = Long.toUnsignedString(vLong);
    System.out.println(sLong); // 18446744073709551615

    // Guava 18.0
    int vIntGu = UnsignedInts.parseUnsignedInt(UnsignedInteger.MAX_VALUE.toString());
    System.out.println(vIntGu); // -1
    String sIntGu = UnsignedInts.toString(vIntGu);
    System.out.println(sIntGu); // 4294967295

    long vLongGu = UnsignedLongs.parseUnsignedLong("18446744073709551615");
    System.out.println(vLongGu); // -1
    String sLongGu = UnsignedLongs.toString(vLongGu);
    System.out.println(sLongGu); // 18446744073709551615

    /**
     Integer - Max range
     Signed: From -2,147,483,648 to 2,147,483,647, from -(2^31) to 2^31 – 1
     Unsigned: From 0 to 4,294,967,295 which equals 2^32 - 1

     Long - Max range
     Signed: From -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807, from -(2^63) to 2^63 - 1
     Unsigned: From 0 to 18,446,744,073,709,551,615 which equals 2^64 – 1
     */

TypeError [ERR_INVALID_ARG_TYPE]: The "path" argument must be of type string. Received type undefined raised when starting react app

None of the other solutions worked for me.

However, adding this to my package.json fixed the issue for me:

"resolutions": {
  "react-dev-utils": "10.0.0"
},

Share variables between files in Node.js?

Save any variable that want to be shared as one object. Then pass it to loaded module so it could access the variable through object reference..

// main.js
var myModule = require('./module.js');
var shares = {value:123};

// Initialize module and pass the shareable object
myModule.init(shares);

// The value was changed from init2 on the other file
console.log(shares.value); // 789

On the other file..

// module.js
var shared = null;

function init2(){
    console.log(shared.value); // 123
    shared.value = 789;
}

module.exports = {
    init:function(obj){
        // Save the shared object on current module
        shared = obj;

        // Call something outside
        init2();
    }
}

Python: Fetch first 10 results from a list

Use the slicing operator:

list = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
list[:10]

Changing the sign of a number in PHP?

function invertSign($value)
{
    return -$value;
}

error: Libtool library used but 'LIBTOOL' is undefined

For people using Tiny Core Linux, you also need to install libtool-dev as it has the *.m4 files needed for libtoolize.

Filtering a spark dataframe based on date

I find the most readable way to express this is using a sql expression:

df.filter("my_date < date'2015-01-01'")

we can verify this works correctly by looking at the physical plan from .explain()

+- *(1) Filter (isnotnull(my_date#22) && (my_date#22 < 16436))

Calling a class method raises a TypeError in Python

Try this:

class mystuff:
    def average(_,a,b,c): #get the average of three numbers
            result=a+b+c
            result=result/3
            return result

#now use the function average from the mystuff class
print mystuff.average(9,18,27)

or this:

class mystuff:
    def average(self,a,b,c): #get the average of three numbers
            result=a+b+c
            result=result/3
            return result

#now use the function average from the mystuff class
print mystuff.average(9,18,27)

Convert base64 string to ArrayBuffer

Javascript is a fine development environment so it seems odd than it doesn't provide a solution to this small problem. The solutions offered elsewhere on this page are potentially slow. Here is my solution. It employs the inbuilt functionality that decodes base64 image and sound data urls.

var req = new XMLHttpRequest;
req.open('GET', "data:application/octet;base64," + base64Data);
req.responseType = 'arraybuffer';
req.onload = function fileLoaded(e)
{
   var byteArray = new Uint8Array(e.target.response);
   // var shortArray = new Int16Array(e.target.response);
   // var unsignedShortArray = new Int16Array(e.target.response);
   // etc.
}
req.send();

The send request fails if the base 64 string is badly formed.

The mime type (application/octet) is probably unnecessary.

Tested in chrome. Should work in other browsers.

An Authentication object was not found in the SecurityContext - Spring 3.2.2

I had the same problem when and I solved it by using the following annotation :

@EnableAutoConfiguration(exclude = {
        SecurityAutoConfiguration.class
})
public class Application {...}

I think the behavior is the same as what Abhishek explained

How can I label points in this scatterplot?

I have tried directlabels package for putting text labels. In the case of scatter plots it's not still perfect, but much better than manually adjusting the positions, specially in the cases that you are preparing the draft plots and not the final one - so you need to change and make plot again and again -.

comma separated string of selected values in mysql

Check this

SELECT GROUP_CONCAT(id)  FROM table_level where parent_id=4 group by parent_id;

How to set a default value for an existing column

Just Found 3 simple steps to alter already existing column that was null before

update   orders
set BasicHours=0 where BasicHours is null

alter table orders 
add default(0) for BasicHours

alter table orders 
alter  column CleanBasicHours decimal(7,2) not null 

Setting Icon for wpf application (VS 08)

You can try this also:

private void Page_Loaded_1(object sender, RoutedEventArgs e)
    {
        Uri iconUri = new Uri(@"C:\Apps\R&D\WPFNavigation\WPFNavigation\Images\airport.ico", UriKind.RelativeOrAbsolute);
        (this.Parent as Window).Icon = BitmapFrame.Create(iconUri);
    }

ASP.NET Core return JSON with status code

With ASP.NET Core 2.0, the ideal way to return object from Web API (which is unified with MVC and uses same base class Controller) is

public IActionResult Get()
{
    return new OkObjectResult(new Item { Id = 123, Name = "Hero" });
}

Notice that

  1. It returns with 200 OK status code (it's an Ok type of ObjectResult)
  2. It does content negotiation, i.e. it'll return based on Accept header in request. If Accept: application/xml is sent in request, it'll return as XML. If nothing is sent, JSON is default.

If it needs to send with specific status code, use ObjectResult or StatusCode instead. Both does the same thing, and supports content negotiation.

return new ObjectResult(new Item { Id = 123, Name = "Hero" }) { StatusCode = 200 };
return StatusCode( 200, new Item { Id = 123, Name = "Hero" });

or even more fine grained with ObjectResult:

 Microsoft.AspNetCore.Mvc.Formatters.MediaTypeCollection myContentTypes = new Microsoft.AspNetCore.Mvc.Formatters.MediaTypeCollection { System.Net.Mime.MediaTypeNames.Application.Json };
 String hardCodedJson = "{\"Id\":\"123\",\"DateOfRegistration\":\"2012-10-21T00:00:00+05:30\",\"Status\":0}";
 return new ObjectResult(hardCodedJson) { StatusCode = 200, ContentTypes = myContentTypes };

If you specifically want to return as JSON, there are couple of ways

//GET http://example.com/api/test/asjson
[HttpGet("AsJson")]
public JsonResult GetAsJson()
{
    return Json(new Item { Id = 123, Name = "Hero" });
}

//GET http://example.com/api/test/withproduces
[HttpGet("WithProduces")]
[Produces("application/json")]
public Item GetWithProduces()
{
    return new Item { Id = 123, Name = "Hero" };
}

Notice that

  1. Both enforces JSON in two different ways.
  2. Both ignores content negotiation.
  3. First method enforces JSON with specific serializer Json(object).
  4. Second method does the same by using Produces() attribute (which is a ResultFilter) with contentType = application/json

Read more about them in the official docs. Learn about filters here.

The simple model class that is used in the samples

public class Item
{
    public int Id { get; set; }
    public string Name { get; set; }
}

Android ClassNotFoundException: Didn't find class on path

I found this error in Android Studio when i tried do debug in a device with API 23, so i checked the Android Studio and i noticed that i didnt had instaled this API 23 version. After install, i solved the problem.

JavaScript ES6 promise for loop

As you already hinted in your question, your code creates all promises synchronously. Instead they should only be created at the time the preceding one resolves.

Secondly, each promise that is created with new Promise needs to be resolved with a call to resolve (or reject). This should be done when the timer expires. That will trigger any then callback you would have on that promise. And such a then callback (or await) is a necessity in order to implement the chain.

With those ingredients, there are several ways to perform this asynchronous chaining:

  1. With a for loop that starts with an immediately resolving promise

  2. With Array#reduce that starts with an immediately resolving promise

  3. With a function that passes itself as resolution callback

  4. With ECMAScript2017's async / await syntax

  5. With ECMAScript2020's for await...of syntax

See a snippet and comments for each of these options below.

1. With for

You can use a for loop, but you must make sure it doesn't execute new Promise synchronously. Instead you create an initial immediately resolving promise, and then chain new promises as the previous ones resolve:

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for (let i = 0, p = Promise.resolve(); i < 10; i++) {
    p = p.then(_ => new Promise(resolve =>
        setTimeout(function () {
            console.log(i);
            resolve();
        }, Math.random() * 1000)
    ));
}
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2. With reduce

This is just a more functional approach to the previous strategy. You create an array with the same length as the chain you want to execute, and start out with an immediately resolving promise:

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[...Array(10)].reduce( (p, _, i) => 
    p.then(_ => new Promise(resolve =>
        setTimeout(function () {
            console.log(i);
            resolve();
        }, Math.random() * 1000)
    ))
, Promise.resolve() );
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This is probably more useful when you actually have an array with data to be used in the promises.

3. With a function passing itself as resolution-callback

Here we create a function and call it immediately. It creates the first promise synchronously. When it resolves, the function is called again:

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(function loop(i) {
    if (i < 10) new Promise((resolve, reject) => {
        setTimeout( () => {
            console.log(i);
            resolve();
        }, Math.random() * 1000);
    }).then(loop.bind(null, i+1));
})(0);
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This creates a function named loop, and at the very end of the code you can see it gets called immediately with argument 0. This is the counter, and the i argument. The function will create a new promise if that counter is still below 10, otherwise the chaining stops.

The call to resolve() will trigger the then callback which will call the function again. loop.bind(null, i+1) is just a different way of saying _ => loop(i+1).

4. With async/await

Modern JS engines support this syntax:

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(async function loop() {
    for (let i = 0; i < 10; i++) {
        await new Promise(resolve => setTimeout(resolve, Math.random() * 1000));
        console.log(i);
    }
})();
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It may look strange, as it seems like the new Promise() calls are executed synchronously, but in reality the async function returns when it executes the first await. Every time an awaited promise resolves, the function's running context is restored, and proceeds after the await, until it encounters the next one, and so it continues until the loop finishes.

As it may be a common thing to return a promise based on a timeout, you could create a separate function for generating such a promise. This is called promisifying a function, in this case setTimeout. It may improve the readability of the code:

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const delay = ms => new Promise(resolve => setTimeout(resolve, ms));

(async function loop() {
    for (let i = 0; i < 10; i++) {
        await delay(Math.random() * 1000);
        console.log(i);
    }
})();
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5. With for await...of

With EcmaScript 2020, the for await...of found its way to modern JavaScript engines. Although it does not really reduce code in this case, it allows to isolate the definition of the random interval chain from the actual iteration of it:

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const delay = ms => new Promise(resolve => setTimeout(resolve, ms));
async function * randomDelays(count ,max) {
    for (let i = 0; i < count; i++) yield delay(Math.random() * max).then(() => i);
}

(async function loop() {
    for await (let i of randomDelays(10, 1000)) console.log(i);
})();
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No signing certificate "iOS Distribution" found

You need to have the private key of the signing certificate in the keychain along with the public key. Have you created the certificate using the same Mac (keychain) ?

Solution #1:

  • Revoke the signing certificate (reset) from apple developer portal
  • Create the signing certificate again on the same mac (keychain). Then you will have the private key for the signing certificate!

Solution #2:

  • Export the signing identities from the origin xCode
  • Import the signing on your xCode

Apple documentation: https://developer.apple.com/library/content/documentation/IDEs/Conceptual/AppDistributionGuide/MaintainingCertificates/MaintainingCertificates.html

How to get complete current url for Cakephp

Use Html helper

<?php echo $this->Html->url($this->here, true); ?> 

It'll produce the full url which'll started from http or https

What's the "average" requests per second for a production web application?

Note that hit-rate graphs will be sinusoidal patterns with 'peak hours' maybe 2x or 3x the rate that you get while users are sleeping. (Can be useful when you're scheduling the daily batch-processing stuff to happen on servers)

You can see the effect even on 'international' (multilingual, localised) sites like wikipedia

Postgres integer arrays as parameters?

See: http://www.postgresql.org/docs/9.1/static/arrays.html

If your non-native driver still does not allow you to pass arrays, then you can:

  • pass a string representation of an array (which your stored procedure can then parse into an array -- see string_to_array)

    CREATE FUNCTION my_method(TEXT) RETURNS VOID AS $$ 
    DECLARE
           ids INT[];
    BEGIN
           ids = string_to_array($1,',');
           ...
    END $$ LANGUAGE plpgsql;
    

    then

    SELECT my_method(:1)
    

    with :1 = '1,2,3,4'

  • rely on Postgres itself to cast from a string to an array

    CREATE FUNCTION my_method(INT[]) RETURNS VOID AS $$ 
           ...
    END $$ LANGUAGE plpgsql;
    

    then

    SELECT my_method('{1,2,3,4}')
    
  • choose not to use bind variables and issue an explicit command string with all parameters spelled out instead (make sure to validate or escape all parameters coming from outside to avoid SQL injection attacks.)

    CREATE FUNCTION my_method(INT[]) RETURNS VOID AS $$ 
           ...
    END $$ LANGUAGE plpgsql;
    

    then

    SELECT my_method(ARRAY [1,2,3,4])
    

How to get current instance name from T-SQL

Why stop at just the instance name? You can inventory your SQL Server environment with following:

SELECT  
    SERVERPROPERTY('ServerName') AS ServerName,  
    SERVERPROPERTY('MachineName') AS MachineName,
    CASE 
        WHEN  SERVERPROPERTY('InstanceName') IS NULL THEN ''
        ELSE SERVERPROPERTY('InstanceName')
    END AS InstanceName,
    '' as Port, --need to update to strip from Servername. Note: Assumes Registered Server is named with Port
    SUBSTRING ( (SELECT @@VERSION),1, CHARINDEX('-',(SELECT @@VERSION))-1 ) as ProductName,
    SERVERPROPERTY('ProductVersion') AS ProductVersion,  
    SERVERPROPERTY('ProductLevel') AS ProductLevel,
    SERVERPROPERTY('ProductMajorVersion') AS ProductMajorVersion,
    SERVERPROPERTY('ProductMinorVersion') AS ProductMinorVersion,
    SERVERPROPERTY('ProductBuild') AS ProductBuild,
    SERVERPROPERTY('Edition') AS Edition,
    CASE SERVERPROPERTY('EngineEdition')
        WHEN 1 THEN 'PERSONAL'
        WHEN 2 THEN 'STANDARD'
        WHEN 3 THEN 'ENTERPRISE'
        WHEN 4 THEN 'EXPRESS'
        WHEN 5 THEN 'SQL DATABASE'
        WHEN 6 THEN 'SQL DATAWAREHOUSE'
    END AS EngineEdition,  
    CASE SERVERPROPERTY('IsHadrEnabled')
        WHEN 0 THEN 'The Always On Availability Groups feature is disabled'
        WHEN 1 THEN 'The Always On Availability Groups feature is enabled'
        ELSE 'Not applicable'
    END AS HadrEnabled,
    CASE SERVERPROPERTY('HadrManagerStatus')
        WHEN 0 THEN 'Not started, pending communication'
        WHEN 1 THEN 'Started and running'
        WHEN 2 THEN 'Not started and failed'
        ELSE 'Not applicable'
    END AS HadrManagerStatus,
    CASE SERVERPROPERTY('IsSingleUser') WHEN 0 THEN 'No' ELSE 'Yes' END AS InSingleUserMode,
    CASE SERVERPROPERTY('IsClustered')
        WHEN 1 THEN 'Clustered'
        WHEN 0 THEN 'Not Clustered'
        ELSE 'Not applicable'
    END AS IsClustered,
    '' as ServerEnvironment,
    '' as ServerStatus,
    '' as Comments

Change link color of the current page with CSS

JavaScript will get the job done.

Get all links in the document and compare their reference URLs to the document's URL. If there is a match, add a class to that link.

JavaScript

<script>
    currentLinks = document.querySelectorAll('a[href="'+document.URL+'"]')
    currentLinks.forE??ach(function(link) {
        link.className += ' current-link')
    });
</script>

One Liner Version of Above

document.querySelectorAll('a[href="'+document.URL+'"]').forE??ach(function(elem){e??lem.className += ' current-link')});

CSS

.current-link {
    color:#baada7;
}

Other Notes

Taraman's jQuery answer above only searches on [href] which will return link tags and tags other than a which rely on the href attribute. Searching on a[href='*https://urlofcurrentpage.com*'] captures only those links which meets the criteria and therefore runs faster.

In addtion, if you don't need to rely on the jQuery library, a vanilla JavaScript solution is definitely the way to go.

How to insert close button in popover for Bootstrap

Try this:

$(function(){
  $("#example")
      .popover({
      title : 'tile',
      content : 'test'
    })
    .on('shown', function(e){
      var popover =  $(this).data('popover'),
        $tip = popover.tip();

      var close = $('<button type="button" class="close" aria-label="Close"><span aria-hidden="true">&times;</span></button>')
        .click(function(){
          popover.hide();
        });
      $('.popover-title', $tip).append(close);
    });
});

Rather than adding the button as a string of markup, it's much easier if you have a jQuery wrapped button because then you can bind much more neatly. This is indeed sadly missing from the Bootstrap code, but this workaround works for me, and actually could be expanded to apply to all popovers if desired.

MD5 is 128 bits but why is it 32 characters?

32 chars as hexdecimal representation, thats 2 chars per byte.

get the titles of all open windows

Something like this:

using System.Diagnostics;

Process[] processlist = Process.GetProcesses();

foreach (Process process in processlist)
{
    if (!String.IsNullOrEmpty(process.MainWindowTitle))
    {
        Console.WriteLine("Process: {0} ID: {1} Window title: {2}", process.ProcessName, process.Id, process.MainWindowTitle);
    }
}

Type datetime for input parameter in procedure

In this part of your SP:

IF @DateFirst <> '' and @DateLast <> ''
   set @FinalSQL  = @FinalSQL
       + '  or convert (Date,DateLog) >=     ''' + @DateFirst
       + ' and convert (Date,DateLog) <=''' + @DateLast  

you are trying to concatenate strings and datetimes.

As the datetime type has higher priority than varchar/nvarchar, the + operator, when it happens between a string and a datetime, is interpreted as addition, not as concatenation, and the engine then tries to convert your string parts (' or convert (Date,DateLog) >= ''' and others) to datetime or numeric values. And fails.

That doesn't happen if you omit the last two parameters when invoking the procedure, because the condition evaluates to false and the offending statement isn't executed.

To amend the situation, you need to add explicit casting of your datetime variables to strings:

set @FinalSQL  = @FinalSQL
    + '  or convert (Date,DateLog) >=     ''' + convert(date, @DateFirst)
    + ' and convert (Date,DateLog) <=''' + convert(date, @DateLast)

You'll also need to add closing single quotes:

set @FinalSQL  = @FinalSQL
    + '  or convert (Date,DateLog) >=     ''' + convert(date, @DateFirst) + ''''
    + ' and convert (Date,DateLog) <=''' + convert(date, @DateLast) + ''''

Retrieve version from maven pom.xml in code

There is also the method described in Easy way to display your apps version number using Maven:

Add this to pom.xml

<build>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-jar-plugin</artifactId>
      <configuration>
        <archive>
          <manifest>
            <mainClass>test.App</mainClass>
            <addDefaultImplementationEntries>
              true
            </addDefaultImplementationEntries>
          </manifest>
        </archive>
      </configuration>
    </plugin>
  </plugins>
</build>

Then use this:

App.class.getPackage().getImplementationVersion()

I have found this method to be simpler.

How to use if statements in underscore.js templates?

From here:

"You can also refer to the properties of the data object via that object, instead of accessing them as variables." Meaning that for OP's case this will work (with a significantly smaller change than other possible solutions):

<% if (obj.date) { %><span class="date"><%= date %></span><% }  %>

Convert a negative number to a positive one in JavaScript

You can use ~ operator that logically converts the number to negative and adds 1 to the negative:

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var x = 3;_x000D_
x = (~x + 1);_x000D_
console.log(x)_x000D_
// result = -3
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Python json.loads shows ValueError: Extra data

I came across this because I was trying to load a JSON file dumped from MongoDB. It was giving me an error

JSONDecodeError: Extra data: line 2 column 1

The MongoDB JSON dump has one object per line, so what worked for me is:

import json
data = [json.loads(line) for line in open('data.json', 'r')]

isPrime Function for Python Language

Srsly guys... Why so many lines of code for a simple method like this? Here's my solution:

def isPrime(a):
    div = a - 1
    res = True
    while(div > 1):
        if a % div == 0:
            res = False
        div = div - 1
    return res

How to escape regular expression special characters using javascript?

Use the \ character to escape a character that has special meaning inside a regular expression.

To automate it, you could use this:

function escapeRegExp(text) {
  return text.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, '\\$&');
}

Update: There is now a proposal to standardize this method, possibly in ES2016: https://github.com/benjamingr/RegExp.escape

Update: The abovementioned proposal was rejected, so keep implementing this yourself if you need it.

React Router Pass Param to Component

Here's typescript version. works on "react-router-dom": "^4.3.1"

export const AppRouter: React.StatelessComponent = () => {
    return (
        <BrowserRouter>
            <Switch>
                <Route exact path="/problem/:problemId" render={props => <ProblemPage {...props.match.params} />} />
                <Route path="/" exact component={App} />
            </Switch>
        </BrowserRouter>
    );
};

and component

export class ProblemPage extends React.Component<ProblemRouteTokens> {

    public render(): JSX.Element {
        return <div>{this.props.problemId}</div>;
    }
}

where ProblemRouteTokens

export interface ProblemRouteTokens { problemId: string; }

How do I do pagination in ASP.NET MVC?

I think the easiest way to create pagination in ASP.NET MVC application is using PagedList library.

There is a complete example in following github repository. Hope it would help.

public class ProductController : Controller
{
    public object Index(int? page)
    {
        var list = ItemDB.GetListOfItems();

        var pageNumber = page ?? 1; 
        var onePageOfItem = list.ToPagedList(pageNumber, 25); // will only contain 25 items max because of the pageSize

        ViewBag.onePageOfItem = onePageOfProducts;
        return View();
    }
}

Demo Link: http://ajaxpagination.azurewebsites.net/

Source Code: https://github.com/ungleng/SimpleAjaxPagedListAndSearchMVC5

PHP - Move a file into a different folder on the server

Create a function to move it:

function move_file($file, $to){
    $path_parts = pathinfo($file);
    $newplace   = "$to/{$path_parts['basename']}";
    if(rename($file, $newplace))
        return $newplace;
    return null;
}

How to uninstall Eclipse?

Right click on eclipse icon and click on open file location then delete the eclipse folder from drive(Save backup of your eclipse workspace if you want). Also delete eclipse icon. Thats it..

HTTP Status 504

If your using ASP.Net 5 (now known as ASP.Net Core v1) ensure in your project.json "commands" section for each site you are hosting that the Kestrel proxy listening port differs between sites, otherwise one site will work but the other will return a 504 gateway timeout.

 "commands": {
    "web": "Microsoft.AspNet.Server.Kestrel --server.urls http://localhost:5090"
  },

Setting a Sheet and cell as variable

Yes, set the cell as a RANGE object one time and then use that RANGE object in your code:

Sub RangeExample()
Dim MyRNG As Range

Set MyRNG = Sheets("Sheet1").Cells(23, 4)

Debug.Print MyRNG.Value

End Sub

Alternately you can simply store the value of that cell in memory and reference the actual value, if that's all you really need. That variable can be Long or Double or Single if numeric, or String:

Sub ValueExample()
Dim MyVal As String

MyVal = Sheets("Sheet1").Cells(23, 4).Value

Debug.Print MyVal

End Sub

How do I record audio on iPhone with AVAudioRecorder?

I've been trying to get this code to work for the last 2 hours and though it showed no error on the simulator, there was one on the device.

Turns out, at least in my case that the error came from directory used (bundle) :

NSURL *url = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/recordTest.caf", [[NSBundle mainBundle] resourcePath]]];

It was not writable or something like this... There was no error except the fact that prepareToRecord failed...

I therefore replaced it by :

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *recDir = [paths objectAtIndex:0];
NSURL *url = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/recordTest.caf", recDir]]

It now Works like a Charm.

Hope this helps others.

Add more than one parameter in Twig path

Consider making your route:

_files_manage:
    pattern: /files/management/{project}/{user}
    defaults: { _controller: AcmeTestBundle:File:manage }

since they are required fields. It will make your url's prettier, and be a bit easier to manage.

Your Controller would then look like

 public function projectAction($project, $user)

What’s the difference between “{}” and “[]” while declaring a JavaScript array?

Syntax of JSON

object = {} | { members }

  • members = pair | pair, members
  • pair = string : value

array = [] | [ elements ]

  • elements = value | value elements

value = string|number|object|array|true|false|null

Map over object preserving keys

How about this version in plain JS (ES6 / ES2015)?

let newObj = Object.assign(...Object.keys(obj).map(k => ({[k]: obj[k] * 3})));

jsbin

If you want to map over an object recursively (map nested obj), it can be done like this:

const mapObjRecursive = (obj) => {
  Object.keys(obj).forEach(key => {
    if (typeof obj[key] === 'object') obj[key] = mapObjRecursive(obj[key]);
    else obj[key] = obj[key] * 3;
  });
  return obj;
};

jsbin

Since ES7 / ES2016 you can use Object.entries instead of Object.keys like this:

let newObj = Object.assign(...Object.entries(obj).map([k, v] => ({[k]: v * 3})));

How to install Anaconda on RaspBerry Pi 3 Model B

On Raspberry Pi 3 Model B - Installation of Miniconda (bundled with Python 3)

Go and get the latest version of miniconda for Raspberry Pi - made for armv7l processor and bundled with Python 3 (eg.: uname -m)

wget http://repo.continuum.io/miniconda/Miniconda3-latest-Linux-armv7l.sh
md5sum Miniconda3-latest-Linux-armv7l.sh
bash Miniconda3-latest-Linux-armv7l.sh

After installation, source your updated .bashrc file with source ~/.bashrc. Then enter the command python --version, which should give you:

Python 3.4.3 :: Continuum Analytics, Inc.

How to Execute SQL Script File in Java?

The Apache iBatis solution worked like a charm.

The script example I used was exactly the script I was running from MySql workbench.

There is an article with examples here: https://www.tutorialspoint.com/how-to-run-sql-script-using-jdbc#:~:text=You%20can%20execute%20.,to%20pass%20a%20connection%20object.&text=Register%20the%20MySQL%20JDBC%20Driver,method%20of%20the%20DriverManager%20class.

This is what I did:

pom.xml dependency

<!-- IBATIS SQL Script runner from Apache (https://mvnrepository.com/artifact/org.apache.ibatis/ibatis-core) -->
<dependency>
    <groupId>org.apache.ibatis</groupId>
    <artifactId>ibatis-core</artifactId>
    <version>3.0</version>
</dependency>

Code to execute script:

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.Reader;
import java.sql.Connection;   
import org.apache.ibatis.jdbc.ScriptRunner;   
import lombok.extern.slf4j.Slf4j;

@Slf4j
public class SqlScriptExecutor {

    public static void executeSqlScript(File file, Connection conn) throws Exception {
        Reader reader = new BufferedReader(new FileReader(file));
        log.info("Running script from file: " + file.getCanonicalPath());
        ScriptRunner sr = new ScriptRunner(conn);
        sr.setAutoCommit(true);
        sr.setStopOnError(true);
        sr.runScript(reader);
        log.info("Done.");
    }
    
}

Fragments within Fragments

Nested fragments are supported in android 4.2 and later

The Android Support Library also now supports nested fragments, so you can implement nested fragment designs on Android 1.6 and higher.

To nest a fragment, simply call getChildFragmentManager() on the Fragment in which you want to add a fragment. This returns a FragmentManager that you can use like you normally do from the top-level activity to create fragment transactions. For example, here’s some code that adds a fragment from within an existing Fragment class:

Fragment videoFragment = new VideoPlayerFragment();
FragmentTransaction transaction = getChildFragmentManager().beginTransaction();
transaction.add(R.id.video_fragment, videoFragment).commit();

To get more idea about nested fragments, please go through these tutorials
Part 1
Part 2
Part 3

and here is a SO post which discuss about best practices for nested fragments.

What is the ultimate postal code and zip regex?

Why are you doing this and why do you care? As Tom Ritter pointed out, it doesn't matter whether you even have a ZIP/postal code at all, much less whether it's valid or not, until and unless you are actually going to be sending something to that address. Even if you expect that you will be sending them something someday, that doesn't mean you need a postal code today.

How does OAuth 2 protect against things like replay attacks using the Security Token?

The other answer is very detailed and addresses the bulk of the questions raised by the OP.

To elaborate, and specifically to address the OP's question of "How does OAuth 2 protect against things like replay attacks using the Security Token?", there are two additional protections in the official recommendations for implementing OAuth 2:

1) Tokens will usually have a short expiration period (http://tools.ietf.org/html/rfc6819#section-5.1.5.3):

A short expiration time for tokens is a means of protection against the following threats:

  • replay...

2) When the token is used by Site A, the recommendation is that it will be presented not as URL parameters but in the Authorization request header field (http://tools.ietf.org/html/rfc6750):

Clients SHOULD make authenticated requests with a bearer token using the "Authorization" request header field with the "Bearer" HTTP authorization scheme. ...

The "application/x-www-form-urlencoded" method SHOULD NOT be used except in application contexts where participating browsers do not have access to the "Authorization" request header field. ...

URI Query Parameter... is included to document current use; its use is not recommended, due to its security deficiencies

How do I capture all of my compiler's output to a file?

The output went to stderr. Use 2> to capture that.

$make 2> file

How to convert a Collection to List?

I think Paul Tomblin's answer may be wasteful in case coll is already a list, because it will create a new list and copy all elements. If coll contains many elemeents, this may take a long time.

My suggestion is:

List list;
if (coll instanceof List)
  list = (List)coll;
else
  list = new ArrayList(coll);
Collections.sort(list);

How to use LINQ Distinct() with multiple fields

This is my solution, it supports keySelectors of different types:

public static IEnumerable<TSource> DistinctBy<TSource>(this IEnumerable<TSource> source, params Func<TSource, object>[] keySelectors)
{
    // initialize the table
    var seenKeysTable = keySelectors.ToDictionary(x => x, x => new HashSet<object>());

    // loop through each element in source
    foreach (var element in source)
    {
        // initialize the flag to true
        var flag = true;

        // loop through each keySelector a
        foreach (var (keySelector, hashSet) in seenKeysTable)
        {                    
            // if all conditions are true
            flag = flag && hashSet.Add(keySelector(element));
        }

        // if no duplicate key was added to table, then yield the list element
        if (flag)
        {
            yield return element;
        }
    }
}

To use it:

list.DistinctBy(d => d.CategoryId, d => d.CategoryName)

How to inspect Javascript Objects

The for-in loops for each property in an object or array. You can use this property to get to the value as well as change it.

Note: Private properties are not available for inspection, unless you use a "spy"; basically, you override the object and write some code which does a for-in loop inside the object's context.

For in looks like:

for (var property in object) loop();

Some sample code:

function xinspect(o,i){
    if(typeof i=='undefined')i='';
    if(i.length>50)return '[MAX ITERATIONS]';
    var r=[];
    for(var p in o){
        var t=typeof o[p];
        r.push(i+'"'+p+'" ('+t+') => '+(t=='object' ? 'object:'+xinspect(o[p],i+'  ') : o[p]+''));
    }
    return r.join(i+'\n');
}

// example of use:
alert(xinspect(document));

Edit: Some time ago, I wrote my own inspector, if you're interested, I'm happy to share.

Edit 2: Well, I wrote one up anyway.

Online SQL syntax checker conforming to multiple databases

I don't know of any such, and my experience is that it doesn't currently exist. Most are side by side comparisons of two databases. That information requires experts in all the databases encountered, which isn't common. Versions depend too, to know what is supported.

ANSI functions are making strides to ensure syntax is supported across databases, but it's dependent on vendors implementing the spec. And to date, they aren't implementing the entire ANSI spec at a time.

But you can crowd source on sites like this one by asking specific questions and including the databases involved and the versions used.

How do you run a .exe with parameters using vba's shell()?

Here are some examples of how to use Shell in VBA.
Open stackoverflow in Chrome.

Call Shell("C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" & _
 " -url" & " " & "www.stackoverflow.com",vbMaximizedFocus)

Open some text file.

Call Shell ("notepad C:\Users\user\Desktop\temp\TEST.txt")

Open some application.

Call Shell("C:\Temp\TestApplication.exe",vbNormalFocus)

Hope this helps!

django: TypeError: 'tuple' object is not callable

There is comma missing in your tuple.

insert the comma between the tuples as shown:

pack_size = (('1', '1'),('3', '3'),(b, b),(h, h),(d, d), (e, e),(r, r))

Do the same for all

What is the best Java email address validation method?

Current Apache Commons Validator version is 1.3.1.

Class that validates is org.apache.commons.validator.EmailValidator. It has an import for org.apache.oro.text.perl.Perl5Util which is from a retired Jakarta ORO project.

BTW, I found that there is a 1.4 version, here are the API docs. On the site it says: "Last Published: 05 March 2008 | Version: 1.4-SNAPSHOT", but that's not final. Only way to build yourself (but this is a snapshot, not RELEASE) and use, or download from here. This means 1.4 has not been made final for three years (2008-2011). This is not in Apache's style. I'm looking for a better option, but didn't find one that is very adopted. I want to use something that is well tested, don't want to hit any bugs.

C++ Double Address Operator? (&&)

This is C++11 code. In C++11, the && token can be used to mean an "rvalue reference".

Unable to connect with remote debugger

in my case it also need to install it's npm package

so

npm install react-native-debugger -g

Root element is missing

Make sure you XML looks like this:

<?xml version="1.0" encoding="utf-8"?>
<rootElement>
...
</rootElement>

Also, a blank XML file will return the same Root elements is missing exception. Each XML file must have a root element / node which encloses all the other elements.

How do I split a string so I can access item x?

I know it's an old Question, but i think some one can benefit from my solution.

select 
SUBSTRING(column_name,1,CHARINDEX(' ',column_name,1)-1)
,SUBSTRING(SUBSTRING(column_name,CHARINDEX(' ',column_name,1)+1,LEN(column_name))
    ,1
    ,CHARINDEX(' ',SUBSTRING(column_name,CHARINDEX(' ',column_name,1)+1,LEN(column_name)),1)-1)
,SUBSTRING(SUBSTRING(column_name,CHARINDEX(' ',column_name,1)+1,LEN(column_name))
    ,CHARINDEX(' ',SUBSTRING(column_name,CHARINDEX(' ',column_name,1)+1,LEN(column_name)),1)+1
    ,LEN(column_name))
from table_name

SQL FIDDLE

Advantages:

  • It separates all the 3 sub-strings deliminator by ' '.
  • One must not use while loop, as it decreases the performance.
  • No need to Pivot as all the resultant sub-string will be displayed in one Row

Limitations:

  • One must know the total no. of spaces (sub-string).

Note: the solution can give sub-string up to to N.

To overcame the limitation we can use the following ref.

But again the above solution can't be use in a table (Actaully i wasn't able to use it).

Again i hope this solution can help some-one.

Update: In case of Records > 50000 it is not advisable to use LOOPS as it will degrade the Performance

How to change package name in flutter?

Quickest and cleanest way to change your package name :

Warning : You may want to save some files in android/ and ios/ folder before it gets deleted !

  1. Delete your folders at the root of your flutter project :
  • android/
  • ios/
  • build/
  1. Let's say you want to rename from com.oldcompany.oldproject to com.newcompany.newproject Launch the following code :

    flutter create --org com.newcompany --project-name newproject .
    

PS : To make sure everything is set up correctly, you can search for your package names in your files, by typing the commands grep --color -r com.oldcompany.oldproject * and grep --color -r com.newcompany.newproject *

How to pass data from Javascript to PHP and vice versa?

There's a few ways, the most prominent being getting form data, or getting the query string. Here's one method using JavaScript. When you click on a link it will call the _vals('mytarget', 'theval') which will submit the form data. When your page posts back you can check if this form data has been set and then retrieve it from the form values.

<script language="javascript" type="text/javascript">
 function _vals(target, value){
   form1.all("target").value=target;
   form1.all("value").value=value;
   form1.submit();
 }
</script>

Alternatively you can get it via the query string. PHP has your _GET and _SET global functions to achieve this making it much easier.

I'm sure there's probably more methods which are better, but these are just a few that spring to mind.

EDIT: Building on this from what others have said using the above method you would have an anchor tag like

<a onclick="_vals('name', 'val')" href="#">My Link</a>

And then in your PHP you can get form data using

$val = $_POST['value'];

So when you click on the link which uses JavaScript it will post form data and when the page posts back from this click you can then retrieve it from the PHP.

How do I write output in same place on the console?

A neat solution that has been working for me is:

from __future__ import print_function
import sys
for i in range(10**6):
    perc = float(i) / 10**6 * 100
    print(">>> Download is {}% complete      ".format(perc), end='\r')
    sys.stdout.flush()
print("")

The sys.stdout.flush is important otherwise it gets really clunky and the print("") on for loop exit is also important.

UPDATE: As mentioned in the comments, print also has a flush argument. So the following will also work:

from __future__ import print_function
for i in range(10**6):
    perc = float(i) / 10**6 * 100
    print(">>> Download is {}% complete      ".format(perc), end='\r', flush=True)
print("")

Forward X11 failed: Network error: Connection refused

PuTTY can't find where your X server is, because you didn't tell it. (ssh on Linux doesn't have this problem because it runs under X so it just uses that one.) Fill in the blank box after "X display location" with your Xming server's address.

Alternatively, try MobaXterm. It has an X server builtin.

js window.open then print()

What worked for me was adding myWindow.document.close() after myWindow.document.write(). Here's my solution with a timeout to wait for the new window to finish loading (if you have a lot to load):

var win = window.open('', 'PrintWindow');
win.document.write('Stuff to print...');

setTimeout(function () {
    win.document.close();
    win.focus();
    win.print();
    win.close(); 
}, 1000);

Two dimensional array in python

We can create multidimensional array dynamically as follows,

Create 2 variables to read x and y from standard input:

 print("Enter the value of x: ")
 x=int(input())

 print("Enter the value of y: ")
 y=int(input())

Create an array of list with initial values filled with 0 or anything using the following code

z=[[0 for row in range(0,x)] for col in range(0,y)]

creates number of rows and columns for your array data.

Read data from standard input:

for i in range(x):
         for j in range(y):
             z[i][j]=input()

Display the Result:

for i in range(x):
         for j in range(y):
             print(z[i][j],end=' ')
         print("\n")

or use another way to display above dynamically created array is,

for row in z:
     print(row)

Bad Gateway 502 error with Apache mod_proxy and Tomcat

you should be able to get this problem resolved through a timeout and proxyTimeout parameter set to 600 seconds. It worked for me after battling for a while.

java.lang.UnsatisfiedLinkError: dalvik.system.PathClassLoader

Yet another crash cause and possible solution is described in this article: https://medium.com/keepsafe-engineering/the-perils-of-loading-native-libraries-on-android-befa49dce2db

Briefly:
in build.gradle

dependencies {
    implementation 'com.getkeepsafe.relinker:relinker:1.2.3'
}

in code

static {
    try {
        System.loadLibrary("<your_libs_name>");
    } catch (UnsatisfiedLinkError e) {
        ReLinker.loadLibrary(context, "<your_libs_name>");
    }
}

What is the meaning of 'No bundle URL present' in react-native?

another thing that working for me , is to open the project in xcode, and then clean and build it. usually it reruns the packaging server and solve the problem.

How to completely uninstall kubernetes

If you are clearing the cluster so that you can start again, then, in addition to what @rib47 said, I also do the following to ensure my systems are in a state ready for kubeadm init again:

kubeadm reset -f
rm -rf /etc/cni /etc/kubernetes /var/lib/dockershim /var/lib/etcd /var/lib/kubelet /var/run/kubernetes ~/.kube/*
iptables -F && iptables -X
iptables -t nat -F && iptables -t nat -X
iptables -t raw -F && iptables -t raw -X
iptables -t mangle -F && iptables -t mangle -X
systemctl restart docker

You then need to re-install docker.io, kubeadm, kubectl, and kubelet to make sure they are at the latest versions for your distribution before you re-initialize the cluster.

EDIT: Discovered that calico adds firewall rules to the raw table so that needs clearing out as well.

SQL LEFT JOIN Subquery Alias

I recognize that the answer works and has been accepted but there is a much cleaner way to write that query. Tested on mysql and postgres.

SELECT wpoi.order_id As No_Commande
FROM  wp_woocommerce_order_items AS wpoi
LEFT JOIN wp_postmeta AS wpp ON wpoi.order_id = wpp.post_id 
                            AND wpp.meta_key = '_shipping_first_name'
WHERE  wpoi.order_id =2198 

How to set the java.library.path from Eclipse

If you are adding it as a VM argument, make sure you prefix it with -D:

-Djava.library.path=blahblahblah...

JDK on OSX 10.7 Lion

You can download jdk6 here http://support.apple.com/kb/DL1573

Wish it helps

How do I calculate percentiles with python/numpy?

Here's how to do it without numpy, using only python to calculate the percentile.

import math

def percentile(data, percentile):
    size = len(data)
    return sorted(data)[int(math.ceil((size * percentile) / 100)) - 1]

p5 = percentile(mylist, 5)
p25 = percentile(mylist, 25)
p50 = percentile(mylist, 50)
p75 = percentile(mylist, 75)
p95 = percentile(mylist, 95)

Trying to include a library, but keep getting 'undefined reference to' messages

The trick here is to put the library AFTER the module you are compiling. The problem is a reference thing. The linker resolves references in order, so when the library is BEFORE the module being compiled, the linker gets confused and does not think that any of the functions in the library are needed. By putting the library AFTER the module, the references to the library in the module are resolved by the linker.

Delete directories recursively in Java

Maybe a solution for this problem might be to reimplement the delete method of the File class using the code from erickson's answer:

public class MyFile extends File {

  ... <- copy constructor

  public boolean delete() {
    if (f.isDirectory()) {
      for (File c : f.listFiles()) {
        return new MyFile(c).delete();
      }
    } else {
        return f.delete();
    }
  }
}

How to properly compare two Integers in Java?

Calling

if (a == b)

Will work most of the time, but it's not guaranteed to always work, so do not use it.

The most proper way to compare two Integer classes for equality, assuming they are named 'a' and 'b' is to call:

if(a != null && a.equals(b)) {
  System.out.println("They are equal");
}

You can also use this way which is slightly faster.

   if(a != null && b != null && (a.intValue() == b.intValue())) {
      System.out.println("They are equal");
    } 

On my machine 99 billion operations took 47 seconds using the first method, and 46 seconds using the second method. You would need to be comparing billions of values to see any difference.

Note that 'a' may be null since it's an Object. Comparing in this way will not cause a null pointer exception.

For comparing greater and less than, use

if (a != null && b!=null) {
    int compareValue = a.compareTo(b);
    if (compareValue > 0) {
        System.out.println("a is greater than b");
    } else if (compareValue < 0) {
        System.out.println("b is greater than a");
    } else {
            System.out.println("a and b are equal");
    }
} else {
    System.out.println("a or b is null, cannot compare");
}

'MOD' is not a recognized built-in function name

In TSQL, the modulo is done with a percent sign.

SELECT 38 % 5 would give you the modulo 3

How do I speed up the gwt compiler?

  • Split your application into multiple modules or entry points and re-compile then only when needed.
  • Analyse your application using the trunk version - which provides the Story of your compile. This may or may not be relevant to the 1.6 compiler but it can indicate what's going on.

How to print_r $_POST array?

The foreach loops work just fine, but you can also simply

print_r($_POST);

Or for pretty printing in a browser:

echo "<pre>";
print_r($_POST);
echo "</pre>";

filtering NSArray into a new NSArray in Objective-C

NSPredicate is nextstep's way of constructing condition to filter a collection (NSArray, NSSet, NSDictionary).

For example consider two arrays arr and filteredarr:

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF contains[c] %@",@"c"];

filteredarr = [NSMutableArray arrayWithArray:[arr filteredArrayUsingPredicate:predicate]];

the filteredarr will surely have the items that contains the character c alone.

to make it easy to remember those who little sql background it is

*--select * from tbl where column1 like '%a%'--*

1)select * from tbl --> collection

2)column1 like '%a%' --> NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF contains[c] %@",@"c"];

3)select * from tbl where column1 like '%a%' -->

[NSMutableArray arrayWithArray:[arr filteredArrayUsingPredicate:predicate]];

I hope this helps

Array initialization in Perl

What do you mean by "initialize an array to zero"? Arrays don't contain "zero" -- they can contain "zero elements", which is the same as "an empty list". Or, you could have an array with one element, where that element is a zero: my @array = (0);

my @array = (); should work just fine -- it allocates a new array called @array, and then assigns it the empty list, (). Note that this is identical to simply saying my @array;, since the initial value of a new array is the empty list anyway.

Are you sure you are getting an error from this line, and not somewhere else in your code? Ensure you have use strict; use warnings; in your module or script, and check the line number of the error you get. (Posting some contextual code here might help, too.)

Understanding __get__ and __set__ and Python descriptors

I tried (with minor changes as suggested) the code from Andrew Cooke's answer. (I am running python 2.7).

The code:

#!/usr/bin/env python
class Celsius:
    def __get__(self, instance, owner): return 9 * (instance.fahrenheit + 32) / 5.0
    def __set__(self, instance, value): instance.fahrenheit = 32 + 5 * value / 9.0

class Temperature:
    def __init__(self, initial_f): self.fahrenheit = initial_f
    celsius = Celsius()

if __name__ == "__main__":

    t = Temperature(212)
    print(t.celsius)
    t.celsius = 0
    print(t.fahrenheit)

The result:

C:\Users\gkuhn\Desktop>python test2.py
<__main__.Celsius instance at 0x02E95A80>
212

With Python prior to 3, make sure you subclass from object which will make the descriptor work correctly as the get magic does not work for old style classes.

How to call python script on excel vba?

This code will works:

 your_path= ActiveWorkbook.Path & "\your_python_file.py" 
 Shell "RunDll32.Exe Url.Dll,FileProtocolHandler " & your_path, vbNormalFocus 

ActiveWorkbook.Path return the current directory of the workbook. The shell command open the file through the shell of Windows.

Convert Map<String,Object> to Map<String,String>

Now that we have Java 8/streams, we can add one more possible answer to the list:

Assuming that each of the values actually are String objects, the cast to String should be safe. Otherwise some other mechanism for mapping the Objects to Strings may be used.

Map<String,Object> map = new HashMap<>();
Map<String,String> newMap = map.entrySet().stream()
     .collect(Collectors.toMap(Map.Entry::getKey, e -> (String)e.getValue()));

HSL to RGB color conversion

This is how I do it which is easy to remember is to think of RGB as three spokes on a wheel, 120 degrees apart.

H = hue (0-360)
S = saturation (0-1)
L = luminance (0-1)

R1 = SIN( H ) * L 
G1 = SIN( H + 120 ) * L 
B1 = SIN( H + 240 ) * L 

The tricky part is saturation, which is to a scale down to the average of those three.

AVERAGE = (R1 + G1 + B1) / 3 

R2 = ((R1 - AVERAGE) * S) + AVERAGE 
G2 = ((G1 - AVERAGE) * S) + AVERAGE 
B2 = ((B1 - AVERAGE) * S) + AVERAGE 

RED = R2 * 255 
GREEN = G2 * 255 
BLUE = B2 * 255 

What does "#include <iostream>" do?

That is a C++ standard library header file for input output streams. It includes functionality to read and write from streams. You only need to include it if you wish to use streams.

Print out the values of a (Mat) matrix in OpenCV C++

#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>

#include <iostream>
#include <iomanip>

using namespace cv;
using namespace std;

int main(int argc, char** argv)
{
    double data[4] = {-0.0000000077898273846583732, -0.03749374753019832, -0.0374787251930463, -0.000000000077893623846343843};
    Mat src = Mat(1, 4, CV_64F, &data);
    for(int i=0; i<4; i++)
        cout << setprecision(3) << src.at<double>(0,i) << endl;

    return 0;
}

async at console app in C#?

As a quick and very scoped solution:

Task.Result

Both Task.Result and Task.Wait won't allow to improving scalability when used with I/O, as they will cause the calling thread to stay blocked waiting for the I/O to end.

When you call .Result on an incomplete Task, the thread executing the method has to sit and wait for the task to complete, which blocks the thread from doing any other useful work in the meantime. This negates the benefit of the asynchronous nature of the task.

notasync

In Linux, how to tell how much memory processes are using?

I don't know why the answer seem so complicated... It seems pretty simple to do this with ps:

mem()
{                                                                                                      
    ps -eo rss,pid,euser,args:100 --sort %mem | grep -v grep | grep -i $@ | awk '{printf $1/1024 "MB"; $1=""; print }'
}

Example usage:

$ mem mysql
0.511719MB 781 root /bin/sh /usr/bin/mysqld_safe
0.511719MB 1124 root logger -t mysqld -p daemon.error
2.53516MB 1123 mysql /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib/mysql/plugin --user=mysql --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/run/mysqld/mysqld.sock --port=3306

SyntaxError: import declarations may only appear at top level of a module

I got this on Firefox (FF58). I fixed this with:

  1. It is still experimental on Firefox (from v54): You have to set to true the variable dom.moduleScripts.enabled in about:config

Source: Import page on mozilla (See Browser compatibility)

  1. Add type="module" to your script tag where you import the js file

<script type="module" src="appthatimports.js"></script>

  1. Import files have to be prefixed (./, /, ../ or http:// before)

import * from "./mylib.js"

For more examples, this blog post is good.

Sending and receiving UDP packets?

The receiver must set port of receiver to match port set in sender DatagramPacket. For debugging try listening on port > 1024 (e.g. 8000 or 9000). Ports < 1024 are typically used by system services and need admin access to bind on such a port.

If the receiver sends packet to the hard-coded port it's listening to (e.g. port 57) and the sender is on the same machine then you would create a loopback to the receiver itself. Always use the port specified from the packet and in case of production software would need a check in any case to prevent such a case.

Another reason a packet won't get to destination is the wrong IP address specified in the sender. UDP unlike TCP will attempt to send out a packet even if the address is unreachable and the sender will not receive an error indication. You can check this by printing the address in the receiver as a precaution for debugging.

In the sender you set:

 byte [] IP= { (byte)192, (byte)168, 1, 106 };
 InetAddress address = InetAddress.getByAddress(IP);

but might be simpler to use the address in string form:

 InetAddress address = InetAddress.getByName("192.168.1.106");

In other words, you set target as 192.168.1.106. If this is not the receiver then you won't get the packet.

Here's a simple UDP Receiver that works :

import java.io.IOException;
import java.net.*;

public class Receiver {

    public static void main(String[] args) {
        int port = args.length == 0 ? 57 : Integer.parseInt(args[0]);
        new Receiver().run(port);
    }

    public void run(int port) {    
      try {
        DatagramSocket serverSocket = new DatagramSocket(port);
        byte[] receiveData = new byte[8];
        String sendString = "polo";
        byte[] sendData = sendString.getBytes("UTF-8");

        System.out.printf("Listening on udp:%s:%d%n",
                InetAddress.getLocalHost().getHostAddress(), port);     
        DatagramPacket receivePacket = new DatagramPacket(receiveData,
                           receiveData.length);

        while(true)
        {
              serverSocket.receive(receivePacket);
              String sentence = new String( receivePacket.getData(), 0,
                                 receivePacket.getLength() );
              System.out.println("RECEIVED: " + sentence);
              // now send acknowledgement packet back to sender     
              DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length,
                   receivePacket.getAddress(), receivePacket.getPort());
              serverSocket.send(sendPacket);
        }
      } catch (IOException e) {
              System.out.println(e);
      }
      // should close serverSocket in finally block
    }
}

How do I exclude all instances of a transitive dependency when using Gradle?

I was using spring boot 1.5.10 and tries to exclude logback, the given solution above did not work well, I use configurations instead

configurations.all {
    exclude group: "org.springframework.boot", module:"spring-boot-starter-logging"
}

ASP.NET 2.0 - How to use app_offline.htm

Possible Permission Issue

I know this post is fairly old, but I ran into a similar issue and my file was spelled correctly.

I originally created the app_offline.htm file in another location and then moved it to the root of my application. Because of my setup I then had a permissions issue.

The website acted as if it was not there. Creating the file within the root directory instead of moving it, fixed my problem. (Or you could just fix the permission in properties->security)

Hope it helps someone.

Ant task to run an Ant target only if a file exists?

I think its worth referencing this similar answer: https://stackoverflow.com/a/5288804/64313

Here is a another quick solution. There are other variations possible on this using the <available> tag:

# exit with failure if no files are found
<property name="file" value="${some.path}/some.txt" />
<fail message="FILE NOT FOUND: ${file}">
    <condition><not>
        <available file="${file}" />
    </not></condition>
</fail>

javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25

It is very clear from your exception that it is trying to connect to localhost and not to 10.101.3.229

exception snippet : Could not connect to SMTP host: localhost, port: 25;

1.) Please check if there are any null check which is setting localhost as default value

2.) After restarting, if it is working fine, then it means that only at first-run, the proper value is been taken from Properties and from next run the value is set to default. So keep the property-object as a singleton one and use it all-over your project

String, StringBuffer, and StringBuilder

Personally, I don't think there is any real world use for StringBuffer. When would I ever want to communicate between multiple threads by manipulating a character sequence? That doesn't sound useful at all, but maybe I have yet to see the light :)

PHP calculate age

here's the simple function to calculate age:

<?php
    function age($birthDate){
      //date in mm/dd/yyyy format; or it can be in other formats as well
      //explode the date to get month, day and year
      $birthDate = explode("/", $birthDate);
      //get age from date or birthdate
      $age = (date("md", date("U", mktime(0, 0, 0, $birthDate[0], $birthDate[1], $birthDate[2]))) > date("md")
        ? ((date("Y") - $birthDate[2]) - 1)
        : (date("Y") - $birthDate[2]));
     return $age;
    }

    ?>

    <?php
    echo age('11/05/1991');
    ?>

How to do a simple file search in cmd

dir /b/s *.txt  

searches for all txt file in the directory tree. Before using it just change the directory to root using

cd/

you can also export the list to a text file using

dir /b/s *.exe >> filelist.txt

and search within using

type filelist.txt | find /n "filename"

EDIT 1: Although this dir command works since the old dos days but Win7 added something new called Where

where /r c:\Windows *.exe *.dll

will search for exe & dll in the drive c:\Windows as suggested by @SPottuit you can also copy the output to the clipboard with

where /r c:\Windows *.exe |clip

just wait for the prompt to return and don't copy anything until then.

EDIT 2: If you are searching recursively and the output is big you can always use more to enable paging, it will show -- More -- at the bottom and will scroll to the next page once you press SPACE or moves line by line on pressing ENTER

where /r c:\Windows *.exe |more

For more help try

where/?

TypeError: 'str' object is not callable (Python)

str = 'Hello World String'    
print(str(10)+' Good day!!')

Even I faced this issue with the above code as we are shadowing str() function.

Solution is:

string1 = 'Hello World String'
print(str(10)+' Good day!!')

Unable to add window -- token android.os.BinderProxy is not valid; is your activity running?

What you should do is to check if activity is finishing before showing alert. For this purpose isFinishing() method is defined within Activity class.

Here is what you should do:

if(!isFinishing())
 {
     alert.show();
 }

SQL LEFT-JOIN on 2 fields for MySQL

Let's try this way:

select 
    a.ip, 
    a.os, 
    a.hostname, 
    a.port, 
    a.protocol, 
    b.state
from a
left join b 
    on a.ip = b.ip 
        and a.port = b.port /*if you has to filter by columns from right table , then add this condition in ON clause*/
where a.somecolumn = somevalue /*if you have to filter by some column from left table, then add it to where condition*/

So, in where clause you can filter result set by column from right table only on this way:

...
where b.somecolumn <> (=) null

VBA check if object is set

The (un)safe way to do this - if you are ok with not using option explicit - is...

Not TypeName(myObj) = "Empty"

This also handles the case if the object has not been declared. This is useful if you want to just comment out a declaration to switch off some behaviour...

Dim myObj as Object
Not TypeName(myObj) = "Empty"  '/ true, the object exists - TypeName is Object

'Dim myObj as Object
Not TypeName(myObj) = "Empty"  '/ false, the object has not been declared

This works because VBA will auto-instantiate an undeclared variable as an Empty Variant type. It eliminates the need for an auxiliary Boolean to manage the behaviour.

Angular - POST uploaded file

Looking onto this issue Github - Request/Upload progress handling via @angular/http, angular2 http does not support file upload yet.

For very basic file upload I created such service function as a workaround (using ???????'s answer):

  uploadFile(file:File):Promise<MyEntity> {
    return new Promise((resolve, reject) => {

        let xhr:XMLHttpRequest = new XMLHttpRequest();
        xhr.onreadystatechange = () => {
            if (xhr.readyState === 4) {
                if (xhr.status === 200) {
                    resolve(<MyEntity>JSON.parse(xhr.response));
                } else {
                    reject(xhr.response);
                }
            }
        };

        xhr.open('POST', this.getServiceUrl(), true);

        let formData = new FormData();
        formData.append("file", file, file.name);
        xhr.send(formData);
    });
}

What is the difference between Google App Engine and Google Compute Engine?

Basic difference is that Google App Engine (GAE) is a Platform as a Service (PaaS) whereas Google Compute Engine (GCE) is an Infrastructure as a Service (IaaS).

To run your application in GAE you just need to write your code and deploy it into GAE, no other headache. Since GAE is fully scalable, it will automatically acquire more instances in case the traffic goes higher and decrease the instances when traffic decreases. You will be charged for the resources you really use, I mean, you will be billed for the Instance-Hours, Transferred Data, Storage etc your app really used. But the restriction is, you can create your application in only Python, PHP, Java, NodeJS, .NET, Ruby and **Go.

On the other hand, GCE provides you full infrastructure in the form of Virtual Machine. You have complete control over those VMs' environment and runtime as you can write or install any program there. Actually GCE is the way to use Google Data Centers virtually. In GCE you have to manually configure your infrastructure to handle scalability by using Load Balancer.

Both GAE and GCE are part of Google Cloud Platform.

Update: In March 2014 Google announced a new service under App Engine named Managed Virtual Machine. Managed VMs offers app engine applications a bit more flexibility over app platform, CPU and memory options. Like GCE you can create a custom runtime environment in these VMs for app engine application. Actually Managed VMs of App Engine blurs the frontier between IAAS and PAAS to some extent.

TypeError: $(...).on is not a function

In my case this code solved my error :

(function (window, document, $) {
            'use strict';
             var $html = $('html');
             $('input[name="myiCheck"]').on('ifClicked', function (event) {
             alert("You clicked " + this.value);
             });
})(window, document, jQuery);

You don't should put your function inside $(document).ready

How can I toggle word wrap in Visual Studio?

I use this feature often enough that I add a custom button to the command bar.

  1. Click on the Add or Remove Buttons -> Customize
  2. Click on the Commands tab
  3. Click Add Command...
  4. Select Edit (or Edit|Advanced for newer VS versions) from the list
  5. Find Toggle Word Wrap and drag it onto your bar

MySQL - SELECT WHERE field IN (subquery) - Extremely slow why?

This is similar to my case, where I have a table named tabel_buku_besar. What I need are

  1. Looking for record that have account_code='101.100' in tabel_buku_besar which have companyarea='20000' and also have IDR as currency

  2. I need to get all record from tabel_buku_besar which have account_code same as step 1 but have transaction_number in step 1 result

while using select ... from...where....transaction_number in (select transaction_number from ....), my query running extremely slow and sometimes causing request time out or make my application not responding...

I try this combination and the result...not bad...

`select DATE_FORMAT(L.TANGGAL_INPUT,'%d-%m-%y') AS TANGGAL,
      L.TRANSACTION_NUMBER AS VOUCHER,
      L.ACCOUNT_CODE,
      C.DESCRIPTION,
      L.DEBET,
      L.KREDIT 
 from (select * from tabel_buku_besar A
                where A.COMPANYAREA='$COMPANYAREA'
                      AND A.CURRENCY='$Currency'
                      AND A.ACCOUNT_CODE!='$ACCOUNT'
                      AND (A.TANGGAL_INPUT BETWEEN STR_TO_DATE('$StartDate','%d/%m/%Y') AND STR_TO_DATE('$EndDate','%d/%m/%Y'))) L 
INNER JOIN (select * from tabel_buku_besar A
                     where A.COMPANYAREA='$COMPANYAREA'
                           AND A.CURRENCY='$Currency'
                           AND A.ACCOUNT_CODE='$ACCOUNT'
                           AND (A.TANGGAL_INPUT BETWEEN STR_TO_DATE('$StartDate','%d/%m/%Y') AND STR_TO_DATE('$EndDate','%d/%m/%Y'))) R ON R.TRANSACTION_NUMBER=L.TRANSACTION_NUMBER AND R.COMPANYAREA=L.COMPANYAREA 
LEFT OUTER JOIN master_account C ON C.ACCOUNT_CODE=L.ACCOUNT_CODE AND C.COMPANYAREA=L.COMPANYAREA 
ORDER BY L.TANGGAL_INPUT,L.TRANSACTION_NUMBER`

How to check if a database exists in SQL Server?

Actually it's best to use:

IF DB_ID('dms') IS NOT NULL
   --code mine :)
   print 'db exists'

See https://docs.microsoft.com/en-us/sql/t-sql/functions/db-id-transact-sql and note that this does not make sense with the Azure SQL Database.

TypeScript function overloading

This may be because, when both functions are compiled to JavaScript, their signature is totally identical. As JavaScript doesn't have types, we end up creating two functions taking same number of arguments. So, TypeScript restricts us from creating such functions.

TypeScript supports overloading based on number of parameters, but the steps to be followed are a bit different if we compare to OO languages. In answer to another SO question, someone explained it with a nice example: Method overloading?.

Basically, what we are doing is, we are creating just one function and a number of declarations so that TypeScript doesn't give compile errors. When this code is compiled to JavaScript, the concrete function alone will be visible. As a JavaScript function can be called by passing multiple arguments, it just works.

update query with join on two tables

Try this one

UPDATE employee 
set EMPLOYEE.MAIDEN_NAME = 
  (SELECT ADD1 
   FROM EMPS 
   WHERE EMP_CODE=EMPLOYEE.EMP_CODE);
WHERE EMPLOYEE.EMP_CODE >='00' 
AND EMPLOYEE.EMP_CODE <='ZZ';

.crx file install in chrome

I arrived to this question looking for the same but for Chromium (actually I'm using https://ungoogled-software.github.io). So in case anyone else is looking for the same:

  1. Go to chrome://flags/
  2. Search for Handling of extension MIME type requests
  3. Select Always prompt for install
  4. Search for an extension and copy its URL (something like https://chrome.google.com/webstore/detail/...)
  5. Paste the URL in https://crxextractor.com/ and download the .CRX
  6. Voilà, Chromium will prompt for installation

Python match a string with regex

You do not need regular expressions to check if a substring exists in a string.

line = 'This,is,a,sample,string'
result = bool('sample' in line) # returns True

If you want to know if a string contains a pattern then you should use re.search

line = 'This,is,a,sample,string'
result = re.search(r'sample', line) # finds 'sample'

This is best used with pattern matching, for example:

line = 'my name is bob'
result = re.search(r'my name is (\S+)', line) # finds 'bob'

Inverse of a matrix using numpy

Inverse of a matrix using python and numpy:

>>> import numpy as np
>>> b = np.array([[2,3],[4,5]])
>>> np.linalg.inv(b)
array([[-2.5,  1.5],
       [ 2. , -1. ]])

Not all matrices can be inverted. For example singular matrices are not Invertable:

>>> import numpy as np
>>> b = np.array([[2,3],[4,6]])
>>> np.linalg.inv(b)

LinAlgError: Singular matrix

Solution to singular matrix problem:

try-catch the Singular Matrix exception and keep going until you find a transform that meets your prior criteria AND is also invertable.

Intuition for why matrix inversion can't always be done; like in singular matrices:

Imagine an old overhead film projector that shines a bright light through film onto a white wall. The pixels in the film are projected to the pixels on the wall.

If I stop the film projection on a single frame, you will see the pixels of the film on the wall and I ask you to regenerate the film based on what you see. That's easy, you say, just take the inverse of the matrix that performed the projection. An Inverse of a matrix is the reversal of the projection.

Now imagine if the projector was corrupted, and I put a distorted lens in front of the film. Now multiple pixels are projected to the same spot on the wall. I asked you again to "undo this operation with the matrix inverse". You say: "I can't because you destroyed information with the lens distortion, I can't get back to where we were, because the matrix is either Singular or Degenerate."

A matrix that can be used to transform some data into other data is invertable only if the process can be reversed with no loss of information. If your matrix can't be inverted, perhaps you are defining your projection using a guess-and-check methodology rather than using a process that guarantees a non-corrupting transform.

If you're using a heuristic or anything less than perfect mathematical precision, then you'll have to define another process to manage and quarantine distortions so that programming by Brownian motion can resume.

Source:

http://docs.scipy.org/doc/numpy/reference/generated/numpy.linalg.inv.html#numpy.linalg.inv

character count using jquery

For length including white-space:

$("#id").val().length

For length without white-space:

$("#id").val().replace(/ /g,'').length

For removing only beginning and trailing white-space:

$.trim($("#test").val()).length

For example, the string " t e s t " would evaluate as:

//" t e s t "
$("#id").val(); 

//Example 1
$("#id").val().length; //Returns 9
//Example 2
$("#id").val().replace(/ /g,'').length; //Returns 4
//Example 3
$.trim($("#test").val()).length; //Returns 7

Here is a demo using all of them.

How to decrease prod bundle size?

Its works 100% ng build --prod --aot --build-optimizer --vendor-chunk=true

How do I run a Java program from the command line on Windows?

It is easy. If you have saved your file as A.text first thing you should do is save it as A.java. Now it is a Java file.

Now you need to open cmd and set path to you A.java file before compile it. you can refer this for that.

Then you can compile your file using command

javac A.java

Then run it using

java A

So that is how you compile and run a java program in cmd. You can also go through these material that is Java in depth lessons. Lot of things you need to understand in Java is covered there for beginners.

Limit length of characters in a regular expression?

Is there a way to limit a regex to 100 characters WITH regex?

Your example suggests that you'd like to grab a number from inside the regex and then use this number to place a maximum length on another part that is matched later in the regex. This usually isn't possible in a single pass. Your best bet is to have two separate regular expressions:

  • one to match the maximum length you'd like to use
  • one which uses the previously extracted value to verify that its own match does not exceed the specified length

If you just want to limit the number of characters matched by an expression, most regular expressions support bounds by using braces. For instance,

\d{3}-\d{3}-\d{4}

will match (US) phone numbers: exactly three digits, then a hyphen, then exactly three digits, then another hyphen, then exactly four digits.

Likewise, you can set upper or lower limits:

\d{5,10}

means "at least 5, but not more than 10 digits".


Update: The OP clarified that he's trying to limit the value, not the length. My new answer is don't use regular expressions for that. Extract the value, then compare it against the maximum you extracted from the size parameter. It's much less error-prone.

ES6 Class Multiple inheritance

use Mixins for ES6 multiple Inheritence.

let classTwo = Base => class extends Base{
    // ClassTwo Code
};

class Example extends classTwo(ClassOne) {
    constructor() {
    }
}

Tomcat 8 throwing - org.apache.catalina.webresources.Cache.getResource Unable to add the resource

In your $CATALINA_BASE/conf/context.xml add block below before </Context>

<Resources cachingAllowed="true" cacheMaxSize="100000" />

For more information: http://tomcat.apache.org/tomcat-8.0-doc/config/resources.html

beyond top level package error in relative import

Assumption:
If you are in the package directory, A and test_A are separate packages.

Conclusion:
..A imports are only allowed within a package.

Further notes:
Making the relative imports only available within packages is useful if you want to force that packages can be placed on any path located on sys.path.

EDIT:

Am I the only one who thinks that this is insane!? Why in the world is the current working directory not considered to be a package? – Multihunter

The current working directory is usually located in sys.path. So, all files there are importable. This is behavior since Python 2 when packages did not yet exist. Making the running directory a package would allow imports of modules as "import .A" and as "import A" which then would be two different modules. Maybe this is an inconsistency to consider.

Switch case: can I use a range instead of a one number

If-else should be used in that case, But if there is still a need of switch for any reason, you can do as below, first cases without break will propagate till first break is encountered. As previous answers have suggested I recommend if-else over switch.

switch (number){
            case 1:
            case 2:
            case 3:
            case 4: //do something;
                    break;
            case 5:
            case 6:
            case 7:
            case 8:
            case 9: //Do some other-thing;
                   break;
        }

Set height of <div> = to height of another <div> through .css

It seems like what you're looking for is a variant on the CSS Holy Grail Layout, but in two columns. Check out the resources at this answer for more information.

Load data from txt with pandas

Based on the latest changes in pandas, you can use, read_csv , read_table is deprecated:

import pandas as pd
pd.read_csv("file.txt", sep = "\t")

Generating a unique machine id

Try this one, it gives a unique hard disk ID: Port of DiskId32 for Delphi 7-2010.

How to pass a parameter to Vue @click event handler

When you are using Vue directives, the expressions are evaluated in the context of Vue, so you don't need to wrap things in {}.

@click is just shorthand for v-on:click directive so the same rules apply.

In your case, simply use @click="addToCount(item.contactID)"

box-shadow on bootstrap 3 container

For those wanting the box-shadow on the col-* container itself and not on the .container, you can add another div just inside the col-* element, and add the shadow to that. This element will not have the padding, and therefor not interfere.

The first image has the box-shadow on the col-* element. Because of the 15px padding on the col element, the shadow is pushed to the outside of the div element rather than on the visual edges of it.

box-shadow on col-* element

<div class="col-md-4" style="box-shadow: 0px 2px 25px rgba(0, 0, 0, .25);">
    <div class="thumbnail">
        {!! HTML::image('images/sampleImage.png') !!}
    </div>
</div>

The second image has a wrapper div with the box-shadow on it. This will place the box-shadow on the visual edges of the element.

box-shadow on wrapper div

<div class="col-md-4">
    <div id="wrapper-div" style="box-shadow: 0px 2px 25px rgba(0, 0, 0, .25);">
        <div class="thumbnail">
            {!! HTML::image('images/sampleImage.png') !!}
        </div>
    </div>
</div>

Remove duplicates from a dataframe in PySpark

It is not an import problem. You simply call .dropDuplicates() on a wrong object. While class of sqlContext.createDataFrame(rdd1, ...) is pyspark.sql.dataframe.DataFrame, after you apply .collect() it is a plain Python list, and lists don't provide dropDuplicates method. What you want is something like this:

 (df1 = sqlContext
     .createDataFrame(rdd1, ['column1', 'column2', 'column3', 'column4'])
     .dropDuplicates())

 df1.collect()

Replace transparency in PNG images with white background

The Alpha Remove section of the ImageMagick Usage Guide suggests using the -alpha remove option, e.g.:

convert in.png  -background white  -alpha remove  out.png

...using the -background color of your choosing.

The guide states:

This operation is simple and fast, and does the job without needing any extra memory use, or other side effects that may be associated with alternative transparency removal techniques. It is thus the prefered way of removing image transparency.

It additionally adds the note:

Note that while transparency is 'removed' the alpha channel will remain turned on, but will now be fully-opaque. If you no longer need the alpha channel you can then use Alpha Off to disable it.

Thus, if you do not need the alpha channel you can make your output image size smaller by adding the -alpha off option, e.g:

convert in.png  -background white  -alpha remove  -alpha off  out.png

There are more details on other, often-used techniques for removing transparency described in the Removing Transparency from Images section.

Included in that section is mention of an important caveat to the usage of -flatten as a technique for removing transparency:

However this will not work with "mogrify" or with a sequence of multiple images, basically because the "-flatten" operator is really designed to merge multiple images into a single image.

So, if you are converting several images at once, e.g. generating thumbnails from a PDF file, -flatten will not do what you want (it will flatten all images for all pages into one image). On the other hand, using the -alpha remove technique will still produce multiple images, each one having transparency removed.

Alter column in SQL Server

To set a default value to a column, try this:

ALTER TABLE tb_TableName
ALTER COLUMN Record_Status SET DEFAULT 'default value'

Get an array of list element contents in jQuery

You may do as follows. one line of code will be enough

  • let array = $('ul>li').toArray().map(item => $(item).html());
  • Get the interested element

    1. get children

    2. get the array from toArray() method

    3. filter out the results you want

_x000D_
_x000D_
let array = $('ul>li').toArray().map(item => $(item).html());_x000D_
console.log(array);
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<ul>_x000D_
  <li>text1</li>_x000D_
  <li>text2</li>_x000D_
  <li>text3</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

Retrieving the last record in each group - MySQL

MySQL 8.0 now supports windowing functions, like almost all popular SQL implementations. With this standard syntax, we can write greatest-n-per-group queries:

WITH ranked_messages AS (
  SELECT m.*, ROW_NUMBER() OVER (PARTITION BY name ORDER BY id DESC) AS rn
  FROM messages AS m
)
SELECT * FROM ranked_messages WHERE rn = 1;

Below is the original answer I wrote for this question in 2009:


I write the solution this way:

SELECT m1.*
FROM messages m1 LEFT JOIN messages m2
 ON (m1.name = m2.name AND m1.id < m2.id)
WHERE m2.id IS NULL;

Regarding performance, one solution or the other can be better, depending on the nature of your data. So you should test both queries and use the one that is better at performance given your database.

For example, I have a copy of the StackOverflow August data dump. I'll use that for benchmarking. There are 1,114,357 rows in the Posts table. This is running on MySQL 5.0.75 on my Macbook Pro 2.40GHz.

I'll write a query to find the most recent post for a given user ID (mine).

First using the technique shown by @Eric with the GROUP BY in a subquery:

SELECT p1.postid
FROM Posts p1
INNER JOIN (SELECT pi.owneruserid, MAX(pi.postid) AS maxpostid
            FROM Posts pi GROUP BY pi.owneruserid) p2
  ON (p1.postid = p2.maxpostid)
WHERE p1.owneruserid = 20860;

1 row in set (1 min 17.89 sec)

Even the EXPLAIN analysis takes over 16 seconds:

+----+-------------+------------+--------+----------------------------+-------------+---------+--------------+---------+-------------+
| id | select_type | table      | type   | possible_keys              | key         | key_len | ref          | rows    | Extra       |
+----+-------------+------------+--------+----------------------------+-------------+---------+--------------+---------+-------------+
|  1 | PRIMARY     | <derived2> | ALL    | NULL                       | NULL        | NULL    | NULL         |   76756 |             | 
|  1 | PRIMARY     | p1         | eq_ref | PRIMARY,PostId,OwnerUserId | PRIMARY     | 8       | p2.maxpostid |       1 | Using where | 
|  2 | DERIVED     | pi         | index  | NULL                       | OwnerUserId | 8       | NULL         | 1151268 | Using index | 
+----+-------------+------------+--------+----------------------------+-------------+---------+--------------+---------+-------------+
3 rows in set (16.09 sec)

Now produce the same query result using my technique with LEFT JOIN:

SELECT p1.postid
FROM Posts p1 LEFT JOIN posts p2
  ON (p1.owneruserid = p2.owneruserid AND p1.postid < p2.postid)
WHERE p2.postid IS NULL AND p1.owneruserid = 20860;

1 row in set (0.28 sec)

The EXPLAIN analysis shows that both tables are able to use their indexes:

+----+-------------+-------+------+----------------------------+-------------+---------+-------+------+--------------------------------------+
| id | select_type | table | type | possible_keys              | key         | key_len | ref   | rows | Extra                                |
+----+-------------+-------+------+----------------------------+-------------+---------+-------+------+--------------------------------------+
|  1 | SIMPLE      | p1    | ref  | OwnerUserId                | OwnerUserId | 8       | const | 1384 | Using index                          | 
|  1 | SIMPLE      | p2    | ref  | PRIMARY,PostId,OwnerUserId | OwnerUserId | 8       | const | 1384 | Using where; Using index; Not exists | 
+----+-------------+-------+------+----------------------------+-------------+---------+-------+------+--------------------------------------+
2 rows in set (0.00 sec)

Here's the DDL for my Posts table:

CREATE TABLE `posts` (
  `PostId` bigint(20) unsigned NOT NULL auto_increment,
  `PostTypeId` bigint(20) unsigned NOT NULL,
  `AcceptedAnswerId` bigint(20) unsigned default NULL,
  `ParentId` bigint(20) unsigned default NULL,
  `CreationDate` datetime NOT NULL,
  `Score` int(11) NOT NULL default '0',
  `ViewCount` int(11) NOT NULL default '0',
  `Body` text NOT NULL,
  `OwnerUserId` bigint(20) unsigned NOT NULL,
  `OwnerDisplayName` varchar(40) default NULL,
  `LastEditorUserId` bigint(20) unsigned default NULL,
  `LastEditDate` datetime default NULL,
  `LastActivityDate` datetime default NULL,
  `Title` varchar(250) NOT NULL default '',
  `Tags` varchar(150) NOT NULL default '',
  `AnswerCount` int(11) NOT NULL default '0',
  `CommentCount` int(11) NOT NULL default '0',
  `FavoriteCount` int(11) NOT NULL default '0',
  `ClosedDate` datetime default NULL,
  PRIMARY KEY  (`PostId`),
  UNIQUE KEY `PostId` (`PostId`),
  KEY `PostTypeId` (`PostTypeId`),
  KEY `AcceptedAnswerId` (`AcceptedAnswerId`),
  KEY `OwnerUserId` (`OwnerUserId`),
  KEY `LastEditorUserId` (`LastEditorUserId`),
  KEY `ParentId` (`ParentId`),
  CONSTRAINT `posts_ibfk_1` FOREIGN KEY (`PostTypeId`) REFERENCES `posttypes` (`PostTypeId`)
) ENGINE=InnoDB;

Apache 2.4 - Request exceeded the limit of 10 internal redirects due to probable configuration error

You're getting into looping most likely due to these rules:

RewriteRule ^(.*\.php)$ $1 [L]
RewriteRule ^(wp-(content|admin|includes).*) $1 [L]

Just comment it out and try again in a new browser.

How to add text inside the doughnut chart using Chart.js?

I'd avoid modifying the chart.js code to accomplish this, since it's pretty easy with regular CSS and HTML. Here's my solution:

HTML:

<canvas id="productChart1" width="170"></canvas>
<div class="donut-inner">
    <h5>47 / 60 st</h5>
    <span>(30 / 25 st)</span>
</div>

CSS:

.donut-inner {
   margin-top: -100px;
   margin-bottom: 100px;
}
.donut-inner h5 {
   margin-bottom: 5px;
   margin-top: 0;
}
.donut-inner span {
   font-size: 12px;
}

The output looks like this:

enter image description here

Using comma as list separator with AngularJS

Since this question is quite old and AngularJS had had time to evolve since then, this can now be easily achieved using:

<li ng-repeat="record in records" ng-bind="record + ($last ? '' : ', ')"></li>.

Note that I'm using ngBind instead of interpolation {{ }} as it's much more performant: ngBind will only run when the passed value does actually change. The brackets {{ }}, on the other hand, will be dirty checked and refreshed in every $digest, even if it's not necessary. Source: here, here and here.

_x000D_
_x000D_
angular_x000D_
  .module('myApp', [])_x000D_
  .controller('MyCtrl', ['$scope',_x000D_
    function($scope) {_x000D_
      $scope.records = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];_x000D_
    }_x000D_
  ]);
_x000D_
li {_x000D_
  display: inline-block;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.5.7/angular.min.js"></script>_x000D_
<div ng-app="myApp" ng-controller="MyCtrl">_x000D_
  <ul>_x000D_
    <li ng-repeat="record in records" ng-bind="record + ($last ? '' : ', ')"></li>_x000D_
  </ul>_x000D_
</div>
_x000D_
_x000D_
_x000D_

On a final note, all of the solutions here work and are valid to this day. I'm really found to those which involve CSS as this is more of a presentation issue.

CSS table column autowidth

If you want to make sure that last row does not wrap and thus size the way you want it, have a look at

td {
 white-space: nowrap;
}

How can a Javascript object refer to values in itself?

That's not a JSON object, that's a Javascript object created via object literal notation. (JSON is a textual notation for data exchange (more). If you're dealing with JavaScript source code, and not dealing with a string, you're not dealing with JSON.)

There's no way within the object initializer to refer to another key of the object being initialized, because there's no way to get a reference to the object being created until the initializer is finished. (There's no keyword akin to this or something for this situation.)

Getting full JS autocompletion under Sublime Text

As already mentioned, tern.js is a new and promising project with plugins for Sublime Text, Vim and Emacs. I´ve been using TernJS for Sublime for a while and the suggestions I get are way better than the standard ones:

enter image description here

Tern scans all .js files in your project. You can get support for DOM, nodejs, jQuery, and more by adding "libs" in your .sublime-project file:

"ternjs": {
    "exclude": ["wordpress/**", "node_modules/**"],
    "libs": ["browser", "jquery"],
    "plugins": {
        "requirejs": {
            "baseURL": "./js"
        }
    }
}

enter image description here

Why shouldn't `&apos;` be used to escape single quotes?

If you really need single quotes, apostrophes, you can use

html    | numeric | hex
&lsquo; | &#145;  | &#x91; // for the left/beginning single-quote and
&rsquo; | &#146;  | &#x92; // for the right/ending single-quote

UILabel - Wordwrap text

Xcode 10, Swift 4

Wrapping the Text for a label can also be done on Storyboard by selecting the Label, and using Attributes Inspector.

Lines = 0 Linebreak = Word Wrap

enter image description here

Better way to sort array in descending order

You may specify a comparer(IComparer implementation) as a parameter in Array.Sort, the order of sorting actually depends on comparer. The default comparer is used in ascending sorting

This certificate has an invalid issuer Apple Push Services

  • All my certificates are installed and expire dates are fine.
  • I deleted and reinstalled all my certificates, still no luck

In the end, I right-clicked on the certificate, and selected "Get Info". Under the Trust section, I selected "Always Trust" and this solved my problem.

How to convert a string from uppercase to lowercase in Bash?

The correct way to implement your code is

y="HELLO"
val=$(echo "$y" | tr '[:upper:]' '[:lower:]')
string="$val world"

This uses $(...) notation to capture the output of the command in a variable. Note also the quotation marks around the string variable -- you need them there to indicate that $val and world are a single thing to be assigned to string.

If you have bash 4.0 or higher, a more efficient & elegant way to do it is to use bash builtin string manipulation:

y="HELLO"
string="${y,,} world"

Android device is not connected to USB for debugging (Android studio)

Found out for Samsung, Installing Kies also update the usb driver which solve my problem with connecting my Samsung Galaxy S Advance with Android 4.1.2 to Android Studio on Windows 7 64bit. In this case the devise manager shows device driver is updated and working, but when I connect my phone Android Studio does not recognize my device.

How to check if an element is visible with WebDriver

It is important to see if the element is visible or not as the Driver.FindElement will only check the HTML source. But popup code could be in the page html, and not be visible. Therefore, Driver.FindElement function returns a false positive (and your test will fail)

Sequelize.js delete query?

Here's a ES6 using Await / Async example:

    async deleteProduct(id) {

        if (!id) {
            return {msg: 'No Id specified..', payload: 1};
        }

        try {
            return !!await products.destroy({
                where: {
                    id: id
                }
            });
        } catch (e) {
            return false;
        }

    }

Please note that I'm using the !! Bang Bang Operator on the result of the await which will change the result into a Boolean.

Java: Most efficient method to iterate over all elements in a org.w3c.dom.Document?

for (int i = 0; i < nodeList.getLength(); i++)

change to

for (int i = 0, len = nodeList.getLength(); i < len; i++)

to be more efficient.

The second way of javanna answer may be the best as it tends to use a flatter, predictable memory model.

How does Python manage int and long?

It manages them because int and long are sibling class definitions. They have appropriate methods for +, -, *, /, etc., that will produce results of the appropriate class.

For example

>>> a=1<<30
>>> type(a)
<type 'int'>
>>> b=a*2
>>> type(b)
<type 'long'>

In this case, the class int has a __mul__ method (the one that implements *) which creates a long result when required.

How to format string to money

you will need to convert it to a decimal first, then format it with money format.

EX:

decimal decimalMoneyValue = 1921.39m;
string formattedMoneyValue = String.Format("{0:C}", decimalMoneyValue);

a working example: https://dotnetfiddle.net/soxxuW

FloatingActionButton example with Support Library

I just found some issues on FAB and I want to enhance another answer.


setRippleColor issue

So, the issue will come once you set the ripple color (FAB color on pressed) programmatically through setRippleColor. But, we still have an alternative way to set it, i.e. by calling:

FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
ColorStateList rippleColor = ContextCompat.getColorStateList(context, R.color.fab_ripple_color);
fab.setBackgroundTintList(rippleColor);

Your project need to has this structure:

/res/color/fab_ripple_color.xml

enter image description here

And the code from fab_ripple_color.xml is:

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true" android:color="@color/fab_color_pressed" />
    <item android:state_focused="true" android:color="@color/fab_color_pressed" />
    <item android:color="@color/fab_color_normal"/>
</selector>

Finally, alter your FAB slightly:

<android.support.design.widget.FloatingActionButton
    android:id="@+id/fab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/ic_action_add"
    android:layout_alignParentBottom="true"
    android:layout_alignParentRight="true"
    app:fabSize="normal"
    app:borderWidth="0dp"
    app:elevation="6dp"
    app:pressedTranslationZ="12dp"
    app:rippleColor="@android:color/transparent"/> <!-- set to transparent color -->

For API level 21 and higher, set margin right and bottom to 24dp:

...
android:layout_marginRight="24dp"
android:layout_marginBottom="24dp" />

FloatingActionButton design guides

As you can see on my FAB xml code above, I set:

        ...
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
        app:elevation="6dp"
        app:pressedTranslationZ="12dp"
        ...
  • By setting these attributes, you don't need to set layout_marginTop and layout_marginRight again (only on pre-Lollipop). Android will place it automatically on the right corned side of the screen, which the same as normal FAB in Android Lollipop.

        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
    

Or, you can use this in CoordinatorLayout:

        android:layout_gravity="end|bottom"
  • You need to have 6dp elevation and 12dp pressedTranslationZ, according to this guide from Google.

FAB rules

How to install Android Studio on Ubuntu?

Android Studio is now integrated in JetBrains Toolbox:

This free tool allows to easily install all JetBrains products, and Android Studio as well. Upgrade is automatic.

JetBrains toolbox

On Ubuntu, this tools requires FUSE (Filesystem in Userspace)

Synchronous request in Node.js

Super Request

This is another synchronous module that is based off of request and uses promises. Super simple to use, works well with mocha tests.

npm install super-request

request("http://domain.com")
    .post("/login")
    .form({username: "username", password: "password"})
    .expect(200)
    .expect({loggedIn: true})
    .end() //this request is done 
    //now start a new one in the same session 
    .get("/some/protected/route")
    .expect(200, {hello: "world"})
    .end(function(err){
        if(err){
            throw err;
        }
    });

How to make an AlertDialog in Flutter?

Another easy option to show Dialog is to use stacked_services package

 _dialogService.showDialog(
      title: "Title",
      description: "Dialog message Tex",
         );
     });

How to get the difference between two dictionaries in Python?

This function gives you all the diffs (and what stayed the same) based on the dictionary keys only. It also highlights some nice Dict comprehension, Set operations and python 3.6 type annotations :)

from typing import Dict, Any, Tuple
def get_dict_diffs(a: Dict[str, Any], b: Dict[str, Any]) -> Tuple[Dict[str, Any], Dict[str, Any], Dict[str, Any], Dict[str, Any]]:

    added_to_b_dict: Dict[str, Any] = {k: b[k] for k in set(b) - set(a)}
    removed_from_a_dict: Dict[str, Any] = {k: a[k] for k in set(a) - set(b)}
    common_dict_a: Dict[str, Any] = {k: a[k] for k in set(a) & set(b)}
    common_dict_b: Dict[str, Any] = {k: b[k] for k in set(a) & set(b)}
    return added_to_b_dict, removed_from_a_dict, common_dict_a, common_dict_b

If you want to compare the dictionary values:

values_in_b_not_a_dict = {k : b[k] for k, _ in set(b.items()) - set(a.items())}

How to replace a whole line with sed?

You can also use sed's change line to accomplish this:

sed -i "/aaa=/c\aaa=xxx" your_file_here

This will go through and find any lines that pass the aaa= test, which means that the line contains the letters aaa=. Then it replaces the entire line with aaa=xxx. You can add a ^ at the beginning of the test to make sure you only get the lines that start with aaa= but that's up to you.

bundle install returns "Could not locate Gemfile"

You just need to change directories to your app, THEN run bundle install :)

How to send data with angularjs $http.delete() request?

Please Try to pass parameters in httpoptions, you can follow function below

deleteAction(url, data) {
    const authToken = sessionStorage.getItem('authtoken');
    const options = {
      headers: new HttpHeaders({
        'Content-Type': 'application/json',
        Authorization: 'Bearer ' + authToken,
      }),
      body: data,
    };
    return this.client.delete(url, options);
  }

How do I use InputFilter to limit characters in an EditText in Android?

I have done something like this to keep it simple:

edit_text.filters = arrayOf(object : InputFilter {
    override fun filter(
        source: CharSequence?,
        start: Int,
        end: Int,
        dest: Spanned?,
        dstart: Int,
        dend: Int
    ): CharSequence? {
        return source?.subSequence(start, end)
            ?.replace(Regex("[^A-Za-z0-9 ]"), "")
    }
})

This way we are replacing all the unwanted characters in the new part of the source string with an empty string.

The edit_text variable is the EditText object we are referring to.

The code is written in kotlin.

How can I plot separate Pandas DataFrames as subplots?

You may not need to use Pandas at all. Here's a matplotlib plot of cat frequencies:

enter image description here

x = np.linspace(0, 2*np.pi, 400)
y = np.sin(x**2)

f, axes = plt.subplots(2, 1)
for c, i in enumerate(axes):
  axes[c].plot(x, y)
  axes[c].set_title('cats')
plt.tight_layout()

Leading zeros for Int in Swift

The other answers are good if you are dealing only with numbers using the format string, but this is good when you may have strings that need to be padded (although admittedly a little diffent than the question asked, seems similar in spirit). Also, be careful if the string is longer than the pad.

   let str = "a str"
   let padAmount = max(10, str.count)
   String(repeatElement("-", count: padAmount - str.count)) + str

Output "-----a str"

String literals and escape characters in postgresql

Partially. The text is inserted, but the warning is still generated.

I found a discussion that indicated the text needed to be preceded with 'E', as such:

insert into EscapeTest (text) values (E'This is the first part \n And this is the second');

This suppressed the warning, but the text was still not being returned correctly. When I added the additional slash as Michael suggested, it worked.

As such:

insert into EscapeTest (text) values (E'This is the first part \\n And this is the second');

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2

I was running into a similar error in pywikipediabot. The .decode method is a step in the right direction but for me it didn't work without adding 'ignore':

ignore_encoding = lambda s: s.decode('utf8', 'ignore')

Ignoring encoding errors can lead to data loss or produce incorrect output. But if you just want to get it done and the details aren't very important this can be a good way to move faster.

How to disable the ability to select in a DataGridView?

Use the DataGridView.ReadOnly property

The code in the MSDN example illustrates the use of this property in a DataGridView control intended primarily for display. In this example, the visual appearance of the control is customized in several ways and the control is configured for limited interactivity.

Observe these settings in the sample code:

// Set property values appropriate for read-only
// display and limited interactivity
dataGridView1.AllowUserToAddRows = false;
dataGridView1.AllowUserToDeleteRows = false;
dataGridView1.AllowUserToOrderColumns = true;
dataGridView1.ReadOnly = true;
dataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect;
dataGridView1.MultiSelect = false;
dataGridView1.AutoSizeRowsMode = DataGridViewAutoSizeRowsMode.None;
dataGridView1.AllowUserToResizeColumns = false;
dataGridView1.ColumnHeadersHeightSizeMode = 
DataGridViewColumnHeadersHeightSizeMode.DisableResizing;
dataGridView1.AllowUserToResizeRows = false;
dataGridView1.RowHeadersWidthSizeMode = 
DataGridViewRowHeadersWidthSizeMode.DisableResizing;

Replace the single quote (') character from a string

As for how to represent a single apostrophe as a string in Python, you can simply surround it with double quotes ("'") or you can escape it inside single quotes ('\'').

To remove apostrophes from a string, a simple approach is to just replace the apostrophe character with an empty string:

>>> "didn't".replace("'", "")
'didnt'

Is there an addHeaderView equivalent for RecyclerView?

HeaderView depends on the LayoutManager. None of the default LayoutManagers support this and probably wont. HeaderView in ListView creates a lot of complexity without any significant benefit.

I would suggest creating a base adapter class that adds items for Headers if provided. Don't forget to override notify* methods to offset them properly depending on whether header is present or not.

Find size of object instance in bytes in c#

safe solution with some optimizations CyberSaving/MemoryUsage code. some case:

/* test nullable type */      
TestSize<int?>.SizeOf(null) //-> 4 B

/* test StringBuilder */    
StringBuilder sb = new StringBuilder();
for (int i = 0; i < 100; i++) sb.Append("??????????");
TestSize<StringBuilder>.SizeOf(sb ) //-> 3132 B

/* test Simple array */    
TestSize<int[]>.SizeOf(new int[100]); //-> 400 B

/* test Empty List<int>*/    
var list = new List<int>();  
TestSize<List<int>>.SizeOf(list); //-> 205 B

/* test List<int> with 100 items*/
for (int i = 0; i < 100; i++) list.Add(i);
TestSize<List<int>>.SizeOf(list); //-> 717 B

It works also with classes:

class twostring
{
    public string a { get; set; }
    public string b { get; set; }
}
TestSize<twostring>.SizeOf(new twostring() { a="0123456789", b="0123456789" } //-> 28 B

What's the difference between UTF-8 and UTF-8 without BOM?

UTF with a BOM is better if you use UTF-8 in HTML files and if you use Serbian Cyrillic, Serbian Latin, German, Hungarian or some exotic language on the same page.

That is my opinion (30 years of computing and IT industry).

Location of sqlite database on the device

If you're talking about real device /data/data/<application-package-name> is unaccessible. You must have root rights...

How to merge remote changes at GitHub?

If you "git pull" and it says "Already up-to-date.", and still get this error, it might be because one of your other branches isn't up to date. Try switching to another branch and making sure that one is also up-to-date before trying to "git push" again:

Switch to branch "foo" and update it:

$ git checkout foo
$ git pull

You can see the branches you've got by issuing command:

$ git branch

jQuery's .click - pass parameters to user function

I get the simple solution:

 <button id="btn1" onclick="sendData(20)">ClickMe</button>

<script>
   var id; // global variable
   function sendData(valueId){
     id = valueId;
   }
   $("#btn1").click(function(){
        alert(id);
     });
</script>

My mean is that pass the value onclick event to the javascript function sendData(), initialize to the variable and take it by the jquery event handler method.

This is possible since at first sendData(valueid) gets called and initialize the value. Then after jquery event get's executed and use that value.

This is the straight forward solution and For Detail solution go Here.

Using an IF Statement in a MySQL SELECT query

The IF/THEN/ELSE construct you are using is only valid in stored procedures and functions. Your query will need to be restructured because you can't use the IF() function to control the flow of the WHERE clause like this.

The IF() function that can be used in queries is primarily meant to be used in the SELECT portion of the query for selecting different data based on certain conditions, not so much to be used in the WHERE portion of the query:

SELECT IF(JQ.COURSE_ID=0, 'Some Result If True', 'Some Result If False'), OTHER_COLUMNS
FROM ...
WHERE ...

Call an angular function inside html

Yep, just add parenthesis (calling the function). Make sure the function is in scope and actually returns something.

<ul class="ui-listview ui-radiobutton" ng-repeat="meter in meters">
  <li class = "ui-divider">
    {{ meter.DESCRIPTION }}
    {{ htmlgeneration() }}
  </li>
</ul>

java.lang.IllegalStateException: Fragment not attached to Activity

So the base idea is that you are running a UI operation on a fragment that is getting in the onDetach lifecycle.

When this is happening the fragment is getting off the stack and losing the context of the Activity.

So when you call UI related functions for example calling the progress spinner and you want to leave the fragment check if the Fragment is added to the stack, like this:

if(isAdded){ progressBar.visibility=View.VISIBLE }

What is the most efficient way to create HTML elements using jQuery?

Someone has already made a benchmark: jQuery document.createElement equivalent?

$(document.createElement('div')) is the big winner.

Google Maps JS API v3 - Simple Multiple Marker Example

Accepted answer, rewritten in ES6:

$(document).ready(() => {
  const mapEl = $('#our_map').get(0); // OR document.getElementById('our_map');

  // Display a map on the page
  const map = new google.maps.Map(mapEl, { mapTypeId: 'roadmap' });

  const buildings = [
    {
      title: 'London Eye, London', 
      coordinates: [51.503454, -0.119562],
      info: 'carousel'
    },
    {
      title: 'Palace of Westminster, London', 
      coordinates: [51.499633, -0.124755],
      info: 'palace'
    }
  ];

  placeBuildingsOnMap(buildings, map);
});


const placeBuildingsOnMap = (buildings, map) => {
  // Loop through our array of buildings & place each one on the map  
  const bounds = new google.maps.LatLngBounds();
  buildings.forEach((building) => {
    const position = { lat: building.coordinates[0], lng: building.coordinates[1] }
    // Stretch our bounds to the newly found marker position
    bounds.extend(position);

    const marker = new google.maps.Marker({
      position: position,
      map: map,
      title: building.title
    });

    const infoWindow = new google.maps.InfoWindow();
    // Allow each marker to have an info window
    google.maps.event.addListener(marker, 'click', () => {
      infoWindow.setContent(building.info);
      infoWindow.open(map, marker);
    })

    // Automatically center the map fitting all markers on the screen
    map.fitBounds(bounds);
  })
})

await is only valid in async function

The current implementation of async / await only supports the await keyword inside of async functions Change your start function signature so you can use await inside start.

 var start = async function(a, b) {

 }

For those interested, the proposal for top-level await is currently in Stage 2: https://github.com/tc39/proposal-top-level-await

How to install mechanize for Python 2.7?

pip install mechanize

mechanize supports only python 2.

For python3 refer https://stackoverflow.com/a/31774959/4773973 for alternatives.

Repeat command automatically in Linux

You can run the following and filter the size only. If your file was called somefilename you can do the following

while :; do ls -lh | awk '/some*/{print $5}'; sleep 5; done

One of the many ideas.

Get second child using jQuery

I didn't see it mentioned here, but you can also use CSS spec selectors. See the docs

$('#parentContainer td:nth-child(2)')

Verify if file exists or not in C#

These answers all assume the file you are checking is on the server side. Unfortunately, there is no cast iron way to ensure that a file exists on the client side (e.g. if you are uploading the resume). Sure, you can do it in Javascript but you are still not going to be 100% sure on the server side.

The best way to handle this, in my opinion, is to assume that the user will actually select an appropriate file for upload, and then do whatever work you need to do to ensure the uploaded file is what you expect (hint - assume the user is trying to poison your system in every possible way with his/her input)

Viewing full version tree in git

If you don't need branch or tag name:
git log --oneline --graph --all --no-decorate

If you don't even need color (to avoid tty color sequence):
git log --oneline --graph --all --no-decorate --no-color

And a handy alias (in .gitconfig) to make life easier:

[alias]
  tree = log --oneline --graph --all --no-decorate

Only last option takes effect, so it's even possible to override your alias:
git tree --decorate

Understanding SQL Server LOCKS on SELECT queries

On performance you keep focusing on select.
Shared does not block reads.
Shared lock blocks update.
If you have hundreds of shared locks it is going to take an update a while to get an exclusive lock as it must wait for shared locks to clear.

By default a select (read) takes a shared lock.
Shared (S) locks allow concurrent transactions to read (SELECT) a resource.
A shared lock as no effect on other selects (1 or a 1000).

The difference is how the nolock versus shared lock effects update or insert operation.

No other transactions can modify the data while shared (S) locks exist on the resource.

A shared lock blocks an update!
But nolock does not block an update.

This can have huge impacts on performance of updates. It also impact inserts.

Dirty read (nolock) just sounds dirty. You are never going to get partial data. If an update is changing John to Sally you are never going to get Jolly.

I use shared locks a lot for concurrency. Data is stale as soon as it is read. A read of John that changes to Sally the next millisecond is stale data. A read of Sally that gets rolled back John the next millisecond is stale data. That is on the millisecond level. I have a dataloader that take 20 hours to run if users are taking shared locks and 4 hours to run is users are taking no lock. Shared locks in this case cause data to be 16 hours stale.

Don't use nolocks wrong. But they do have a place. If you are going to cut a check when a byte is set to 1 and then set it to 2 when the check is cut - not a time for a nolock.

Remove columns from dataframe where ALL values are NA

janitor::remove_constant() does this very nicely.

How to Set JPanel's Width and Height?

please, something went xxx*x, and that's not true at all, check that

JButton Size - java.awt.Dimension[width=400,height=40]
JPanel Size - java.awt.Dimension[width=640,height=480]
JFrame Size - java.awt.Dimension[width=646,height=505]

code (basic stuff from Trail: Creating a GUI With JFC/Swing , and yet I still satisfied that that would be outdated )

EDIT: forget setDefaultCloseOperation()

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class FrameSize {

    private JFrame frm = new JFrame();
    private JPanel pnl = new JPanel();
    private JButton btn = new JButton("Get ScreenSize for JComponents");

    public FrameSize() {
        btn.setPreferredSize(new Dimension(400, 40));
        btn.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                System.out.println("JButton Size - " + btn.getSize());
                System.out.println("JPanel Size - " + pnl.getSize());
                System.out.println("JFrame Size - " + frm.getSize());
            }
        });
        pnl.setPreferredSize(new Dimension(640, 480));
        pnl.add(btn, BorderLayout.SOUTH);
        frm.add(pnl, BorderLayout.CENTER);
        frm.setLocation(150, 100);
        frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // EDIT
        frm.setResizable(false);
        frm.pack();
        frm.setVisible(true);
    }

    public static void main(String[] args) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                FrameSize fS = new FrameSize();
            }
        });
    }
}

How can I control Chromedriver open window size?

In java/groovy try:

import java.awt.Toolkit;
import org.openqa.selenium.Dimension;         
import org.openqa.selenium.Point;

...

java.awt.Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();

Dimension maximizedScreenSize = new Dimension((int) screenSize.getWidth(), (int) screenSize.getHeight());
driver.manage().window().setPosition(new Point(0, 0));
driver.manage().window().setSize(maximizedScreenSize);

this will open browser in fullscreen

Assert equals between 2 Lists in Junit

You can use assertEquals in junit.

import org.junit.Assert;   
import org.junit.Test;

    @Test
    public void test_array_pass()
    {
        List<String> actual = Arrays.asList("fee", "fi", "foe");
        List<String> expected = Arrays.asList("fee", "fi", "foe");
        Assert.assertEquals(actual,expected);
    }

If the order of elements is different then it will return error.

If you are asserting a model object list then you should override the equals method in the specific model.

    @Override
    public boolean equals(Object obj) {
        if (obj == this) {
            return true;
        }
        if (obj != null && obj instanceof ModelName) {
            ModelName other = (ModelName) obj;
            return this.getItem().equals(other.getItem()) ;
        }
        return false;
    }

How to take the nth digit of a number in python

First treat the number like a string

number = 9876543210
number = str(number)

Then to get the first digit:

number[0]

The fourth digit:

number[3]

EDIT:

This will return the digit as a character, not as a number. To convert it back use:

int(number[0])

jQuery scrollTop() doesn't seem to work in Safari or Chrome (Windows)

To summarise solutions from a couple of questions/answers:

If you want to get the current scroll offset use:

$(document).scrollTop()

To set the scroll offset use:

$('html,body').scrollTop(x)

To animate the scroll use use:

$('html,body').animate({scrollTop: x});

In Postgresql, force unique on combination of two columns

Create unique constraint that two numbers together CANNOT together be repeated:

ALTER TABLE someTable
ADD UNIQUE (col1, col2)

Passing data between controllers in Angular JS?

Make a factory in your module and add a reference of the factory in controller and use its variables in the controller and now get the value of data in another controller by adding reference where ever you want

How can I programmatically check whether a keyboard is present in iOS app?

Swift implementation:

class KeyboardStateListener: NSObject
{
  static var shared = KeyboardStateListener()
  var isVisible = false

  func start() {
    let nc = NSNotificationCenter.defaultCenter()
    nc.addObserver(self, selector: #selector(didShow), name: UIKeyboardDidShowNotification, object: nil)
    nc.addObserver(self, selector: #selector(didHide), name: UIKeyboardDidHideNotification, object: nil)
  }

  func didShow()
  {
    isVisible = true
  }

  func didHide()
  {
    isVisible = false
  } 
}

Because swift doesn't execute class load method on startup it is important to start this service on app launch:

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject : AnyObject]?) -> Bool
{
  ...    
  KeyboardStateListener.shared.start() 
}

Babel 6 regeneratorRuntime is not defined

If using babel-preset-stage-2 then just have to start the script with --require babel-polyfill.

In my case this error was thrown by Mocha tests.

Following fixed the issue

mocha \"server/tests/**/*.test.js\" --compilers js:babel-register --require babel-polyfill

How do I escape double and single quotes in sed?

It's hard to escape a single quote within single quotes. Try this:

sed "s@['\"]http://www.\([^.]\+).com['\"]@URL_\U\1@g" 

Example:

$ sed "s@['\"]http://www.\([^.]\+\).com['\"]@URL_\U\1@g" <<END
this is "http://www.fubar.com" and 'http://www.example.com' here
END

produces

this is URL_FUBAR and URL_EXAMPLE here