Programs & Examples On #Jpl

A Java Interface to Prolog.

Saving binary data as file using JavaScript from a browser

Use FileSaver.js. It supports Chrome, Edge, Firefox, and IE 10+ (and probably IE < 10 with a few "polyfills" - see Note 4). FileSaver.js implements the saveAs() FileSaver interface in browsers that do not natively support it:
     https://github.com/eligrey/FileSaver.js

Minified version is really small at < 2.5KB, gzipped < 1.2KB.

Usage:

/* TODO: replace the blob content with your byte[] */
var blob = new Blob([yourBinaryDataAsAnArrayOrAsAString], {type: "application/octet-stream"});
var fileName = "myFileName.myExtension";
saveAs(blob, fileName);

You might need Blob.js in some browsers (see Note 3). Blob.js implements the W3C Blob interface in browsers that do not natively support it. It is a cross-browser implementation:
     https://github.com/eligrey/Blob.js

Consider StreamSaver.js if you have files larger than blob's size limitations.

Complete example:

_x000D_
_x000D_
/* Two options_x000D_
 * 1. Get FileSaver.js from here_x000D_
 *     https://github.com/eligrey/FileSaver.js/blob/master/FileSaver.min.js -->_x000D_
 *     <script src="FileSaver.min.js" />_x000D_
 *_x000D_
 * Or_x000D_
 *_x000D_
 * 2. If you want to support only modern browsers like Chrome, Edge, Firefox, etc., _x000D_
 *    then a simple implementation of saveAs function can be:_x000D_
 */_x000D_
function saveAs(blob, fileName) {_x000D_
    var url = window.URL.createObjectURL(blob);_x000D_
_x000D_
    var anchorElem = document.createElement("a");_x000D_
    anchorElem.style = "display: none";_x000D_
    anchorElem.href = url;_x000D_
    anchorElem.download = fileName;_x000D_
_x000D_
    document.body.appendChild(anchorElem);_x000D_
    anchorElem.click();_x000D_
_x000D_
    document.body.removeChild(anchorElem);_x000D_
_x000D_
    // On Edge, revokeObjectURL should be called only after_x000D_
    // a.click() has completed, atleast on EdgeHTML 15.15048_x000D_
    setTimeout(function() {_x000D_
        window.URL.revokeObjectURL(url);_x000D_
    }, 1000);_x000D_
}_x000D_
_x000D_
(function() {_x000D_
    // convert base64 string to byte array_x000D_
    var byteCharacters = atob("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");_x000D_
    var byteNumbers = new Array(byteCharacters.length);_x000D_
    for (var i = 0; i < byteCharacters.length; i++) {_x000D_
        byteNumbers[i] = byteCharacters.charCodeAt(i);_x000D_
    }_x000D_
    var byteArray = new Uint8Array(byteNumbers);_x000D_
    _x000D_
    // now that we have the byte array, construct the blob from it_x000D_
    var blob1 = new Blob([byteArray], {type: "application/octet-stream"});_x000D_
_x000D_
    var fileName1 = "cool.gif";_x000D_
    saveAs(blob1, fileName1);_x000D_
_x000D_
    // saving text file_x000D_
    var blob2 = new Blob(["cool"], {type: "text/plain"});_x000D_
    var fileName2 = "cool.txt";_x000D_
    saveAs(blob2, fileName2);_x000D_
})();
_x000D_
_x000D_
_x000D_


Tested on Chrome, Edge, Firefox, and IE 11 (use FileSaver.js for supporting IE 11).
You can also save from a canvas element. See https://github.com/eligrey/FileSaver.js#saving-a-canvas.

Demos: https://eligrey.com/demos/FileSaver.js/

Blog post by author of FileSaver.js: http://eligrey.com/blog/post/saving-generated-files-on-the-client-side

Note 1: Browser support: https://github.com/eligrey/FileSaver.js#supported-browsers

Note 2: Failed to execute 'atob' on 'Window'

Note 3: Polyfill for browsers not supporting Blob: https://github.com/eligrey/Blob.js
                See http://caniuse.com/#search=blob

Note 4: IE < 10 support (I've not tested this part):
                https://github.com/eligrey/FileSaver.js#ie--10
                https://github.com/eligrey/FileSaver.js/issues/56#issuecomment-30917476

Downloadify is a Flash-based polyfill for supporting IE6-9: https://github.com/dcneiner/downloadify (I don't recommend Flash-based solutions in general, though.)
Demo using Downloadify and FileSaver.js for supporting IE6-9 also: http://sheetjs.com/demos/table.html

Note 5: Creating a BLOB from a Base64 string in JavaScript

Note 6: FileSaver.js examples: https://github.com/eligrey/FileSaver.js#examples

Using curl POST with variables defined in bash script functions

Here's what actually worked for me, after guidance from answers here:

export BASH_VARIABLE="[1,2,3]"
curl http://localhost:8080/path -d "$(cat <<EOF
{
  "name": $BASH_VARIABLE,
  "something": [
    "value1",
    "value2",
    "value3"
  ]
}
EOF
)" -H 'Content-Type: application/json'

Excel VBA Code: Compile Error in x64 Version ('PtrSafe' attribute required)

I think all you need to do for your function is just add PtrSafe: i.e. the first line of your first function should look like this:

Private Declare PtrSafe Function swe_azalt Lib "swedll32.dll" ......

what does this mean ? image/png;base64?

It's an inlined image (png), encoded in base64. It can make a page faster: the browser doesn't have to query the server for the image data separately, saving a round trip.

(It can also make it slower if abused: these resources are not cached, so the bytes are included in each page load.)

What does (function($) {})(jQuery); mean?

A little help:

_x000D_
_x000D_
// an anonymous function_x000D_
  _x000D_
(function () { console.log('allo') });_x000D_
_x000D_
// a self invoked anonymous function_x000D_
_x000D_
(function () { console.log('allo') })();_x000D_
  _x000D_
// a self invoked anonymous function with a parameter called "$"_x000D_
  _x000D_
var jQuery = 'I\'m not jQuery.';_x000D_
_x000D_
(function ($) { console.log($) })(jQuery);
_x000D_
_x000D_
_x000D_

How to solve npm error "npm ERR! code ELIFECYCLE"

I recommend you update your node version to the latest node version recommended by your application or for short update your node version. I encountered this same problem using node version 11.1 but my application was recommending atleast version 10.x.x or 12.x.x I tried all the suggested reply on this thread but non seemed to work for me untill only when i updated my node version to the recommended latest version .i.e. version 12.16.3 then my application ran. enter image description here

Create an array with random values

The shortest approach (ES6)

// randomly generated N = 40 length array 0 <= A[N] <= 39
Array.from({length: 40}, () => Math.floor(Math.random() * 40));

Enjoy!

Accessing Arrays inside Arrays In PHP

If $a is the array that's passed, $a[76][0]['id'] should give '76' and $a[76][1]['id'] should give '81', but I can't test as I don't have PHP installed on this machine.

Windows equivalent of 'touch' (i.e. the node.js way to create an index.html)

I use cmder (a command line emulator)

It allows you to run all Linux commands inside a Windows machine.

It can be downloaded from https://cmder.net/

I really like it

Fill drop down list on selection of another drop down list

enter image description here

enter image description here

enter image description here

Model:

namespace MvcApplicationrazor.Models
{
    public class CountryModel
    {
        public List<State> StateModel { get; set; }
        public SelectList FilteredCity { get; set; }
    }
    public class State
    {
        public int Id { get; set; }
        public string StateName { get; set; }
    }
    public class City
    {
        public int Id { get; set; }
        public int StateId { get; set; }
        public string CityName { get; set; }
    }
}   

Controller:

public ActionResult Index()
        {
            CountryModel objcountrymodel = new CountryModel();
            objcountrymodel.StateModel = new List<State>();
            objcountrymodel.StateModel = GetAllState();
            return View(objcountrymodel);
        }


        //Action result for ajax call
        [HttpPost]
        public ActionResult GetCityByStateId(int stateid)
        {
            List<City> objcity = new List<City>();
            objcity = GetAllCity().Where(m => m.StateId == stateid).ToList();
            SelectList obgcity = new SelectList(objcity, "Id", "CityName", 0);
            return Json(obgcity);
        }
        // Collection for state
        public List<State> GetAllState()
        {
            List<State> objstate = new List<State>();
            objstate.Add(new State { Id = 0, StateName = "Select State" });
            objstate.Add(new State { Id = 1, StateName = "State 1" });
            objstate.Add(new State { Id = 2, StateName = "State 2" });
            objstate.Add(new State { Id = 3, StateName = "State 3" });
            objstate.Add(new State { Id = 4, StateName = "State 4" });
            return objstate;
        }
        //collection for city
        public List<City> GetAllCity()
        {
            List<City> objcity = new List<City>();
            objcity.Add(new City { Id = 1, StateId = 1, CityName = "City1-1" });
            objcity.Add(new City { Id = 2, StateId = 2, CityName = "City2-1" });
            objcity.Add(new City { Id = 3, StateId = 4, CityName = "City4-1" });
            objcity.Add(new City { Id = 4, StateId = 1, CityName = "City1-2" });
            objcity.Add(new City { Id = 5, StateId = 1, CityName = "City1-3" });
            objcity.Add(new City { Id = 6, StateId = 4, CityName = "City4-2" });
            return objcity;
        }

View:

@model MvcApplicationrazor.Models.CountryModel
@{
    ViewBag.Title = "Index";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js"></script>
<script language="javascript" type="text/javascript">
    function GetCity(_stateId) {
        var procemessage = "<option value='0'> Please wait...</option>";
        $("#ddlcity").html(procemessage).show();
        var url = "/Test/GetCityByStateId/";

        $.ajax({
            url: url,
            data: { stateid: _stateId },
            cache: false,
            type: "POST",
            success: function (data) {
                var markup = "<option value='0'>Select City</option>";
                for (var x = 0; x < data.length; x++) {
                    markup += "<option value=" + data[x].Value + ">" + data[x].Text + "</option>";
                }
                $("#ddlcity").html(markup).show();
            },
            error: function (reponse) {
                alert("error : " + reponse);
            }
        });

    }
</script>
<h4>
 MVC Cascading Dropdown List Using Jquery</h4>
@using (Html.BeginForm())
{
    @Html.DropDownListFor(m => m.StateModel, new SelectList(Model.StateModel, "Id", "StateName"), new { @id = "ddlstate", @style = "width:200px;", @onchange = "javascript:GetCity(this.value);" })
    <br />
    <br />
    <select id="ddlcity" name="ddlcity" style="width: 200px">

    </select>

    <br /><br />
  }

client denied by server configuration

In my case, I modified directory tag.

From

<Directory "D:/Devel/matysart/matysart_dev1">
  Allow from all
  Order Deny,Allow
</Directory>

To

<Directory "D:/Devel/matysart/matysart_dev1">
  Require local
</Directory>

And it seriously worked. It's seems changed with Apache 2.4.2.

How to get Last record from Sqlite?

in sqlite, there is a table called sqlite_sequence, this table contains the table name and it's last id number (if the id is auto incremented).

So, to get the last row in a table just put :

Select * from TABLENAME where id=(SELECT * from sqlite_sequence where name ='TABLENAME')

How to Find And Replace Text In A File With C#

You're going to have a hard time writing to the same file you're reading from. One quick way is to simply do this:

File.WriteAllText("test.txt", File.ReadAllText("test.txt").Replace("some text","some other text"));

You can lay that out better with

string str = File.ReadAllText("test.txt");
str = str.Replace("some text","some other text");
File.WriteAllText("test.txt", str);

What is the difference between a generative and a discriminative algorithm?

Generally, there is a practice in machine learning community not to learn something that you don’t want to. For example, consider a classification problem where one's goal is to assign y labels to a given x input. If we use generative model

p(x,y)=p(y|x).p(x)

we have to model p(x) which is irrelevant for the task in hand. Practical limitations like data sparseness will force us to model p(x) with some weak independence assumptions. Therefore, we intuitively use discriminative models for classification.

Map and Reduce in .NET

Linq equivalents of Map and Reduce: If you’re lucky enough to have linq then you don’t need to write your own map and reduce functions. C# 3.5 and Linq already has it albeit under different names.

  • Map is Select:

    Enumerable.Range(1, 10).Select(x => x + 2);
    
  • Reduce is Aggregate:

    Enumerable.Range(1, 10).Aggregate(0, (acc, x) => acc + x);
    
  • Filter is Where:

    Enumerable.Range(1, 10).Where(x => x % 2 == 0);
    

https://www.justinshield.com/2011/06/mapreduce-in-c/

Reduce size of legend area in barplot

The cex parameter will do that for you.

a <- c(3, 2, 2, 2, 1, 2 )
barplot(a, beside = T,
        col = 1:6, space = c(0, 2))
legend("topright", 
       legend = c("a", "b", "c", "d", "e", "f"), 
       fill = 1:6, ncol = 2,
       cex = 0.75)

The plot

How do you convert Html to plain text?

public static string StripTags2(string html) { return html.Replace("<", "<").Replace(">", ">"); }

By this you escape all "<" and ">" in a string. Is this what you want?

How to stretch div height to fill parent div - CSS

Simply add height: 100%; onto the #B2 styling. min-height shouldn't be necessary.

How to delete all files and folders in a directory?

private void ClearFolder(string FolderName)
{
    DirectoryInfo dir = new DirectoryInfo(FolderName);

    foreach(FileInfo fi in dir.GetFiles())
    {
        try
        {
            fi.Delete();
        }
        catch(Exception) { } // Ignore all exceptions
    }

    foreach(DirectoryInfo di in dir.GetDirectories())
    {
        ClearFolder(di.FullName);
        try
        {
            di.Delete();
        }
        catch(Exception) { } // Ignore all exceptions
    }
}

If you know there are no sub-folders, something like this may be the easiest:

    Directory.GetFiles(folderName).ForEach(File.Delete)

sh: react-scripts: command not found after running npm start

The solution that worked for me is below. Try creating React app with this command.

create-react-app react-app --scripts-version 1.1.5

What is the easiest way to push an element to the beginning of the array?

You can use methodsolver to find Ruby functions.

Here is a small script,

require 'methodsolver'

solve { a = [1,2,3]; a.____(0) == [0,1,2,3] }

Running this prints

Found 1 methods
- Array#unshift

You can install methodsolver using

gem install methodsolver

Ruby value of a hash key?

As an addition to e.g. @Intrepidd s answer, in certain situations you want to use fetch instead of []. For fetch not to throw an exception when the key is not found, pass it a default value.

puts "ok" if hash.fetch('key', nil) == 'X'

Reference: https://docs.ruby-lang.org/en/2.3.0/Hash.html .

Angular redirect to login page

Following the awesome answers above I would also like to CanActivateChild: guarding child routes. It can be used to add guard to children routes helpful for cases like ACLs

It goes like this

src/app/auth-guard.service.ts (excerpt)

import { Injectable }       from '@angular/core';
import {
  CanActivate, Router,
  ActivatedRouteSnapshot,
  RouterStateSnapshot,
  CanActivateChild
}                           from '@angular/router';
import { AuthService }      from './auth.service';

@Injectable()
export class AuthGuard implements CanActivate, CanActivateChild {
  constructor(private authService: AuthService, private router:     Router) {}

  canActivate(route: ActivatedRouteSnapshot, state:    RouterStateSnapshot): boolean {
    let url: string = state.url;
    return this.checkLogin(url);
  }

  canActivateChild(route: ActivatedRouteSnapshot, state:  RouterStateSnapshot): boolean {
    return this.canActivate(route, state);
  }

/* . . . */
}

src/app/admin/admin-routing.module.ts (excerpt)

const adminRoutes: Routes = [
  {
    path: 'admin',
    component: AdminComponent,
    canActivate: [AuthGuard],
    children: [
      {
        path: '',
        canActivateChild: [AuthGuard],
        children: [
          { path: 'crises', component: ManageCrisesComponent },
          { path: 'heroes', component: ManageHeroesComponent },
          { path: '', component: AdminDashboardComponent }
        ]
      }
    ]
  }
];

@NgModule({
  imports: [
    RouterModule.forChild(adminRoutes)
  ],
  exports: [
    RouterModule
  ]
})
export class AdminRoutingModule {}

This is taken from https://angular.io/docs/ts/latest/guide/router.html#!#can-activate-guard

Parsing string as JSON with single quotes?

I know it's an old post, but you can use JSON5 for this purpose.

<script src="json5.js"></script>
<script>JSON.stringify(JSON5.parse('{a:1}'))</script>

Home does not contain an export named Home

This is the solution:

  • Go to your file Home.js
  • Make sure you export your file like this in the end of the file:
export default Home;

Codeigniter's `where` and `or_where`

$this->db->where('(a = 1 or a = 2)');

Renaming branches remotely in Git

First checkout to the branch which you want to rename:

git branch -m old_branch new_branch
git push -u origin new_branch

To remove an old branch from remote:

git push origin :old_branch

Clear back stack using fragments

It is working for me,try this one:

public void clearFragmentBackStack() {
        FragmentManager fm = getSupportFragmentManager();
        for (int i = 0; i < fm.getBackStackEntryCount() - 1; i++) {
            fm.popBackStack();
        }
    }

How to format numbers?

Let me also throw my solution in here. I've commented each line for ease of reading and also provided some examples, so it may look big.

_x000D_
_x000D_
function format(number) {_x000D_
_x000D_
    var decimalSeparator = ".";_x000D_
    var thousandSeparator = ",";_x000D_
_x000D_
    // make sure we have a string_x000D_
    var result = String(number);_x000D_
_x000D_
    // split the number in the integer and decimals, if any_x000D_
    var parts = result.split(decimalSeparator);_x000D_
_x000D_
    // if we don't have decimals, add .00_x000D_
    if (!parts[1]) {_x000D_
      parts[1] = "00";_x000D_
    }_x000D_
  _x000D_
    // reverse the string (1719 becomes 9171)_x000D_
    result = parts[0].split("").reverse().join("");_x000D_
_x000D_
    // add thousand separator each 3 characters, except at the end of the string_x000D_
    result = result.replace(/(\d{3}(?!$))/g, "$1" + thousandSeparator);_x000D_
_x000D_
    // reverse back the integer and replace the original integer_x000D_
    parts[0] = result.split("").reverse().join("");_x000D_
_x000D_
    // recombine integer with decimals_x000D_
    return parts.join(decimalSeparator);_x000D_
}_x000D_
_x000D_
document.write("10 => " + format(10) + "<br/>");_x000D_
document.write("100 => " + format(100) + "<br/>");_x000D_
document.write("1000 => " + format(1000) + "<br/>");_x000D_
document.write("10000 => " + format(10000) + "<br/>");_x000D_
document.write("100000 => " + format(100000) + "<br/>");_x000D_
document.write("100000.22 => " + format(100000.22) + "<br/>");
_x000D_
_x000D_
_x000D_

How do I implement onchange of <input type="text"> with jQuery?

You can use .change()

$('input[name=myInput]').change(function() { ... });

However, this event will only fire when the selector has lost focus, so you will need to click somewhere else to have this work.

If that's not quite right for you, you could use some of the other jQuery events like keyup, keydown or keypress - depending on the exact effect you want.

What are -moz- and -webkit-?

These are the vendor-prefixed properties offered by the relevant rendering engines (-webkit for Chrome, Safari; -moz for Firefox, -o for Opera, -ms for Internet Explorer). Typically they're used to implement new, or proprietary CSS features, prior to final clarification/definition by the W3.

This allows properties to be set specific to each individual browser/rendering engine in order for inconsistencies between implementations to be safely accounted for. The prefixes will, over time, be removed (at least in theory) as the unprefixed, the final version, of the property is implemented in that browser.

To that end it's usually considered good practice to specify the vendor-prefixed version first and then the non-prefixed version, in order that the non-prefixed property will override the vendor-prefixed property-settings once it's implemented; for example:

.elementClass {
    -moz-border-radius: 2em;
    -ms-border-radius: 2em;
    -o-border-radius: 2em;
    -webkit-border-radius: 2em;
    border-radius: 2em;
}

Specifically, to address the CSS in your question, the lines you quote:

-webkit-column-count: 3;
-webkit-column-gap: 10px;
-webkit-column-fill: auto;
-moz-column-count: 3;
-moz-column-gap: 10px;
-moz-column-fill: auto;

Specify the column-count, column-gap and column-fill properties for Webkit browsers and Firefox.

References:

How to know function return type and argument types?

Yes it is.

In Python a function doesn't always have to return a variable of the same type (although your code will be more readable if your functions do always return the same type). That means that you can't specify a single return type for the function.

In the same way, the parameters don't always have to be the same type too.

Running MSBuild fails to read SDKToolsPath

I've run into the same error but in a different situation: using VS 2010 Express and trying to use Simmo's answer to explicitly set the SDK version - however WindowsSdkVer.exe (version setter tool) seems to not target Express (understandable since it's limited).

I'm using VS 2010 Express on Win 7 Prof. and it always wants to use v7.0A of the Win SDK (which does not have all the needed exes), and it deosn't matter which version I explicitly set as current using WindowsSdkVer.exe (It keeps reporting it set the current version of the SDK but for VS 2008 although though I only have 2010 Ex installed. )

So my cheap workaround was to install v7.0 WIN SDK (or another version like v7.1) and then rename its file system folder to v7.0A - basically I just lied to VS 2010 Express but it works now!

printf() prints whole array

But still, the memory address for each letter in this address is different.

Memory address is different but as its array of characters they are sequential. When you pass address of first element and use %s, printf will print all characters starting from given address until it finds '\0'.

Spring @ContextConfiguration how to put the right location for the xml

Simple solution is

@ContextConfiguration(locations = { "file:src/main/webapp/WEB-INF/applicationContext.xml" })

from spring forum

How to get a time zone from a location using latitude and longitude coordinates?

Here's how you can use Google's script editor to get the timezoneName and timeZoneId inside a gsheet.

Step 1. Get an API key for Google's timezone API

Step 2. Create a new gsheet. Underneath the 'tools' menu click 'script editor'. Add the following code:

function getTimezone(lat, long) {  
  var apiKey = 'INSERTAPIKEYHERE'
  var url = 'https://maps.googleapis.com/maps/api/timezone/json?location=' + lat + ',' + long + '&timestamp=1331161200&key=' + apiKey 
  var response = UrlFetchApp.fetch(url);
  var data = JSON.parse(response.getContentText());
  return data["timeZoneName"];
}

Step 3. Save and publish your getTimezone() function and use it as shown in the image above.

php exec command (or similar) to not wait for result

"exec nohup setsid your_command"

the nohup allows your_command to continue even though the process that launched may terminate first. If it does, the the SIGNUP signal will be sent to your_command causing it to terminate (unless it catches that signal and ignores it).

Sending the bearer token with axios

Here is a unique way of setting Authorization token in axios. Setting configuration to every axios call is not a good idea and you can change the default Authorization token by:

import axios from 'axios';
axios.defaults.baseURL = 'http://localhost:1010/'
axios.defaults.headers.common = {'Authorization': `bearer ${token}`}
export default axios;

Edit, Thanks to Jason Norwood-Young.

Some API require bearer to be written as Bearer, so you can do:

axios.defaults.headers.common = {'Authorization': `Bearer ${token}`}

Now you don't need to set configuration to every API call. Now Authorization token is set to every axios call.

High CPU Utilization in java application - why?

You may be victim of a garbage collection problem.

When your application requires memory and it's getting low on what it's configured to use the garbage collector will run often which consume a lot of CPU cycles. If it can't collect anything your memory will stay low so it will be run again and again. When you redeploy your application the memory is cleared and the garbage collection won't happen more than required so the CPU utilization stays low until it's full again.

You should check that there is no possible memory leak in your application and that it's well configured for memory (check the -Xmx parameter, see What does Java option -Xmx stand for?)

Also, what are you using as web framework? JSF relies a lot on sessions and consumes a lot of memory, consider being stateless at most!

Node.js https pem error: routines:PEM_read_bio:no start line

I removed this error by write the following code

Open Terminal

  1. openssl req -newkey rsa:2048 -new -nodes -keyout key.pem -out csr.pem

  2. openssl x509 -req -days 365 -in csr.pem -signkey key.pem -out server.crt

Now use the server.crt and key.pem file

app.js or server.js file

var https = require('https');
var https_options = {
  key: fs.readFileSync('key.pem', 'utf8'),
  cert: fs.readFileSync('server.crt', 'utf8')
};

var server = https.createServer(https_options, app).listen(PORT);
console.log('HTTPS Server listening on %s:%s', HOST, PORT);

It works but the certificate is not trusted. You can view the image in image file.

enter image description here

Lost connection to MySQL server during query?

I was running into the same problem. Because of some other issues I had tried to add a cnx.close() line to my other functions. Instead, I removed all these extraneous closes and setup my class like this:

class DBase:

config = {
      'user': 'root',
      'password': '',
      'host': '127.0.0.1',
      'database': 'bio',
      'raise_on_warnings': True,
      'use_pure': False,
      }

def __init__(self):
    import mysql.connector
    self.cnx = mysql.connector.connect(**self.config)
    self.cur = self.cnx.cursor(buffered=True)
    print(self.cnx)
def __enter__(self):
    return DBase()

def __exit__(self, exc_type, exc_val, exc_tb):
    self.cnx.commit()
    if self.cnx:
        self.cnx.close()

Any function that is called within this class is connects, commits, and closes.

Testing if a list of integer is odd or even

There's at least 7 different ways to test if a number is odd or even. But, if you read through these benchmarks, you'll find that as TGH mentioned above, the modulus operation is the fastest:

if (x % 2 == 0)
               //even number
        else
               //odd number

Here are a few other methods (from the website) :

//bitwise operation
if ((x & 1) == 0)
       //even number
else
      //odd number

//bit shifting
if (((x >> 1) << 1) == x)
       //even number
else
       //odd number

//using native library
System.Math.DivRem((long)x, (long)2, out outvalue);
if ( outvalue == 0)
       //even number
else
       //odd number

Spring Boot application.properties value not populating

You can use Environment Class to get data :

@Autowired
private Environment env;
String prop= env.getProperty('some.prop');

how to run a command at terminal from java program?

You need to run it using bash executable like this:

Runtime.getRuntime().exec("/bin/bash -c your_command");

Update: As suggested by xav, it is advisable to use ProcessBuilder instead:

String[] args = new String[] {"/bin/bash", "-c", "your_command", "with", "args"};
Process proc = new ProcessBuilder(args).start();

How do I set up NSZombieEnabled in Xcode 4?

I find this alternative more convenient:

  1. Click the "Run Button Dropdown"
  2. From the list choose Profile
  3. The program "Instruments" should open where you can also choose Zombies
  4. Now you can interact with your app and try to cause the error
  5. As soon as the error happens you should get a hint on when your object was released and therefore deallocated.

Zombies

As soon as a zombie is detected you then get a neat "Zombie Stack" that shows you when the object in question was allocated and where it was retained or released:

Event Type    RefCt     Responsible Caller
Malloc            1     -[MyViewController loadData:]
Retain            2     -[MyDataManager initWithBaseURL:]
Release           1     -[MyDataManager initWithBaseURL:]
Release           0     -[MyViewController loadData:]
Zombie           -1     -[MyService prepareURLReuqest]

Advantages compared to using the diagnostic tab of the Xcode Schemes:

  1. If you forget to uncheck the option in the diagnostic tab there no objects will be released from memory.

  2. You get a more detailed stack that shows you in what methods your corrupt object was allocated / released or retained.

How do you POST to a page using the PHP header() function?

private function sendHttpRequest($host, $path, $query, $port=80){
    header("POST $path HTTP/1.1\r\n" );
    header("Host: $host\r\n" );
    header("Content-type: application/x-www-form-urlencoded\r\n" );
    header("Content-length: " . strlen($query) . "\r\n" );
    header("Connection: close\r\n\r\n" );
    header($query);
}

This will get you right away

Server Discovery And Monitoring engine is deprecated

const mongoose = require("mongoose");

mongoose.connect('mongodb://localhost:27017/Edureka',{ useNewUrlParser: true, useUnifiedTopology: true }, (error)=> {
    const connectionStatus = !error ? 'Success': 'Error Connecting to database';
    console.log(connectionStatus);
});

Converting Array to List

If you don't want to alter the list:

List<Integer> list = Arrays.asList(array)

But if you want to modify it then you can use this:

List<Integer> list = new ArrayList<Integer>(Arrays.asList(ints));

Or just use java8 like the following:

List<Integer> list = Arrays.stream(ints).collect(Collectors.toList());

Java9 has introduced this method:

List<Integer> list = List.of(ints);

However, this will return an immutable list that you can't add to.

You need to do the following to make it mutable:

List<Integer> list = new ArrayList<Integer>(List.of(ints));

ValueError: unsupported format character while forming strings

You might have a typo.. In my case I was saying %w where I meant to say %s.

Select and display only duplicate records in MySQL

Get a list of all duplicate rows from table:

Select * from TABLE1 where PRIMARY_KEY_COLUMN NOT IN ( SELECT PRIMARY_KEY_COLUMN
FROM TABLE1 
GROUP BY DUP_COLUMN_NAME having (count(*) >= 1))

Binding objects defined in code-behind

There's a much easier way of doing this. You can assign a Name to your Window or UserControl, and then binding by ElementName.

Window1.xaml

<Window x:Class="QuizBee.Host.Window1"
        x:Name="Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

    <ListView ItemsSource="{Binding ElementName=Window1, Path=myDictionary}" />
</Window>

Window1.xaml.cs

public partial class Window1:Window
{
    // the property must be public, and it must have a getter & setter
    public Dictionary<string, myClass> myDictionary { get; set; }

    public Window1()
    {
        // define the dictionary items in the constructor
        // do the defining BEFORE the InitializeComponent();

        myDictionary = new Dictionary<string, myClass>()
        {
            {"item 1", new myClass(1)},
            {"item 2", new myClass(2)},
            {"item 3", new myClass(3)},
            {"item 4", new myClass(4)},
            {"item 5", new myClass(5)},
        }; 

        InitializeComponent();
    }
}

Get Value From Select Option in Angular 4

HTML code

    <form class="form-inline" (ngSubmit)="HelloCorp(modelName)">
        <div class="select">
            <select class="form-control col-lg-8" [(ngModel)]="modelName" required>
                <option *ngFor="let corporation of corporations" [ngValue]="corporation">
                    {{corporation.corp_name}}
                </option>    
            </select>
            <button type="submit" class="btn btn-primary manage">Submit</button>
        </div> 
    </form>

Component code

HelloCorp(corporation) {
    var corporationObj = corporation.value;
}

Print in new line, java

"\n" this is the simple method to separate the continuous String

finished with non zero exit value

I had this same exact error all of a sudden the other day. I did a "Clean Project" and a "Rebuild Project" and never saw the error again.

I've only got a few months of Android development under my belt. But whenever I get an unexplained error like this, "Clean Project" and/or "Rebuild Project" are the first things I try.

Generic type conversion FROM string

For many types (integer, double, DateTime etc), there is a static Parse method. You can invoke it using reflection:

MethodInfo m = typeof(T).GetMethod("Parse", new Type[] { typeof(string) } );

if (m != null)
{
    return m.Invoke(null, new object[] { base.Value });
}

rewrite a folder name using .htaccess

try:

RewriteRule ^/apple(.*)?$ /folder1$1 [NC]

Where the folder you want to appear in the url is in the first part of the statement - this is what it will match against and the second part 'rewrites' it to your existing folder. the [NC] flag means that it will ignore case differences eg Apple/ will still forward.

See here for a tutorial: http://www.sitepoint.com/article/guide-url-rewriting/

There is also a nice test utility for windows you can download from here: http://www.helicontech.com/download/rxtest.zip Just to note for the tester you need to leave out the domain name - so the test would be against /folder1/login.php

to redirect from /folder1 to /apple try this:

RewriteRule ^/folder1(.*)?$ /apple$1 [R]

to redirect and then rewrite just combine the above in the htaccess file:

RewriteRule ^/folder1(.*)?$ /apple$1 [R]
RewriteRule ^/apple(.*)?$ /folder1$1 [NC]

How to generate a HTML page dynamically using PHP?

It looks funny but it works.

<?php 
$file = 'newpage.html';
// Open the file to get existing content
$current = file_get_contents($file);
// Append a new person to the file
$current .= "<!doctype html><html>
<head><meta charset='utf-8'>
<title>new file</title>
</head><body><h3>New HTML file</h3>
</body></html>
";
// Write the contents back to the file
file_put_contents($file, $current);
?>

SQL Case Expression Syntax?

Here you can find a complete guide for MySQL case statements in SQL.

CASE
     WHEN some_condition THEN return_some_value
     ELSE return_some_other_value
END

Spring MVC Missing URI template variable

I got this error for a stupid mistake, the variable name in the @PathVariable wasn't matching the one in the @RequestMapping

For example

@RequestMapping(value = "/whatever/{**contentId**}", method = RequestMethod.POST)
public … method(@PathVariable Integer **contentID**){
}

It may help others

How to add a WiX custom action that happens only on uninstall (via MSI)?

I used Custom Action separately coded in C++ DLL and used the DLL to call appropriate function on Uninstalling using this syntax :

<CustomAction Id="Uninstall" BinaryKey="Dll_Name" 
              DllEntry="Function_Name" Execute="deferred" />

Using the above code block, I was able to run any function defined in C++ DLL on uninstall. FYI, my uninstall function had code regarding Clearing current user data and registry entries.

How to fix java.lang.UnsupportedClassVersionError: Unsupported major.minor version

The answer is for the problem:

Exception in thread "main" java.lang.UnsupportedClassVersionError: edu/stevens/cs549/dhts/main/LocalContext : Unsupported major.minor version 52.0

I was having the same problem. For those who were having this trouble in AWS ec2 instances, and have somehow got redirected here to this question. I am answering for those, and would like to share that how I did it. I was having the trouble because Amazon EC2 instances were running java version 1.7 and maybe my project was not compatible with it because I was using Maven and it kind of preconfigured for java 1.8. So I installed new version of java:

sudo yum -y install java-1.8.0

And then the important step is to remove the older version:

sudo yum remove java-1.7.0-openjdk

Remember to delete it after installing the new version, else it would continuously be using the same older version and I hope it resolves your problem, which did in my case.

What is the fastest way to send 100,000 HTTP requests in Python?

A solution:

from twisted.internet import reactor, threads
from urlparse import urlparse
import httplib
import itertools


concurrent = 200
finished=itertools.count(1)
reactor.suggestThreadPoolSize(concurrent)

def getStatus(ourl):
    url = urlparse(ourl)
    conn = httplib.HTTPConnection(url.netloc)   
    conn.request("HEAD", url.path)
    res = conn.getresponse()
    return res.status

def processResponse(response,url):
    print response, url
    processedOne()

def processError(error,url):
    print "error", url#, error
    processedOne()

def processedOne():
    if finished.next()==added:
        reactor.stop()

def addTask(url):
    req = threads.deferToThread(getStatus, url)
    req.addCallback(processResponse, url)
    req.addErrback(processError, url)   

added=0
for url in open('urllist.txt'):
    added+=1
    addTask(url.strip())

try:
    reactor.run()
except KeyboardInterrupt:
    reactor.stop()

Testtime:

[kalmi@ubi1:~] wc -l urllist.txt
10000 urllist.txt
[kalmi@ubi1:~] time python f.py > /dev/null 

real    1m10.682s
user    0m16.020s
sys 0m10.330s
[kalmi@ubi1:~] head -n 6 urllist.txt
http://www.google.com
http://www.bix.hu
http://www.godaddy.com
http://www.google.com
http://www.bix.hu
http://www.godaddy.com
[kalmi@ubi1:~] python f.py | head -n 6
200 http://www.bix.hu
200 http://www.bix.hu
200 http://www.bix.hu
200 http://www.bix.hu
200 http://www.bix.hu
200 http://www.bix.hu

Pingtime:

bix.hu is ~10 ms away from me
godaddy.com: ~170 ms
google.com: ~30 ms

When to use malloc for char pointers

Use malloc() when you don't know the amount of memory needed during compile time. In case if you have read-only strings then you can use const char* str = "something"; . Note that the string is most probably be stored in a read-only memory location and you'll not be able to modify it. On the other hand if you know the string during compiler time then you can do something like: char str[10]; strcpy(str, "Something"); Here the memory is allocated from stack and you will be able to modify the str. Third case is allocating using malloc. Lets say you don'r know the length of the string during compile time. Then you can do char* str = malloc(requiredMem); strcpy(str, "Something"); free(str);

Writing handler for UIAlertAction

You can do it as simple as this using swift 2:

let alertController = UIAlertController(title: "iOScreator", message:
        "Hello, world!", preferredStyle: UIAlertControllerStyle.Alert)
alertController.addAction(UIAlertAction(title: "Dismiss", style: UIAlertActionStyle.Destructive,handler: { action in
        self.pressed()
}))

func pressed()
{
    print("you pressed")
}

    **or**


let alertController = UIAlertController(title: "iOScreator", message:
        "Hello, world!", preferredStyle: UIAlertControllerStyle.Alert)
alertController.addAction(UIAlertAction(title: "Dismiss", style: UIAlertActionStyle.Destructive,handler: { action in
      print("pressed")
 }))

All the answers above are correct i am just showing another way that can be done.

Where is SQLite database stored on disk?

.databases

If you run this command inside SQLite

.databases

it lists the path of all currently connected databases. Sample output:

seq  name             file                                                      
---  ---------------  ----------------------------------------------------------
0    main             /home/me/a.db

How do I use checkboxes in an IF-THEN statement in Excel VBA 2010?

It seems that in VBA macro code for an ActiveX checkbox control you use

If (ActiveSheet.OLEObjects("CheckBox1").Object.Value = True)

and for a Form checkbox control you use

If (ActiveSheet.Shapes("CheckBox1").OLEFormat.Object.Value = 1)

Combining two lists and removing duplicates, without removing duplicates in original list

Based on the recipe :

resulting_list = list(set().union(first_list, second_list))

How to fix corrupted git repository?

I wanted to add this as a comment under Zoey Hewil's awesome answer above, but I don't currently have enough rep to do so, so I have to add it here and give credit for her work :P

If you're using Poshgit and are feeling exceptionally lazy, you can use the following to automatically extract your URL from your git config and make an easy job even easier. Standard caveats apply about testing this on a copy/backing up your local repo first in case it blows up in your face.

$config = get-content .git\config
$url = $config -match " url = (?<content>.*)"
$url = $url.trim().Substring(6)
$url

move-item -v .git .git_old;
git init;
git remote add origin "$url";
git fetch;
git reset origin/master --mixed

GROUP_CONCAT ORDER BY

The group_concat supports its own order by clause

http://mahmudahsan.wordpress.com/2008/08/27/mysql-the-group_concat-function/

So you should be able to write:

SELECT li.clientid, group_concat(li.views order by views) AS views,
group_concat(li.percentage order by percentage) 
FROM table_views GROUP BY client_id

Correct way to initialize HashMap and can HashMap hold different value types?

It really depends on what kind of type safety you need. The non-generic way of doing it is best done as:

 Map x = new HashMap();

Note that x is typed as a Map. this makes it much easier to change implementations (to a TreeMap or a LinkedHashMap) in the future.

You can use generics to ensure a certain level of type safety:

Map<String, Object> x = new HashMap<String, Object>();

In Java 7 and later you can do

Map<String, Object> x = new HashMap<>();

The above, while more verbose, avoids compiler warnings. In this case the content of the HashMap can be any Object, so that can be Integer, int[], etc. which is what you are doing.

If you are still using Java 6, Guava Libraries (although it is easy enough to do yourself) has a method called newHashMap() which avoids the need to duplicate the generic typing information when you do a new. It infers the type from the variable declaration (this is a Java feature not available on constructors prior to Java 7).

By the way, when you add an int or other primitive, Java is autoboxing it. That means that the code is equivalent to:

 x.put("one", Integer.valueOf(1));

You can certainly put a HashMap as a value in another HashMap, but I think there are issues if you do it recursively (that is put the HashMap as a value in itself).

How to print the contents of RDD?

You can also save as a file: rdd.saveAsTextFile("alicia.txt")

Convert date time string to epoch in Bash

For Linux Run this command

date -d '06/12/2012 07:21:22' +"%s"

For mac OSX run this command

date -j -u -f "%a %b %d %T %Z %Y" "Tue Sep 28 19:35:15 EDT 2010" "+%s"

how to "execute" make file

You don't tend to execute the make file itself, rather you execute make, giving it the make file as an argument:

make -f pax.mk

If your make file is actually one of the standard names (like makefile or Makefile), you don't even need to specify it. It'll be picked up by default (if you have more than one of these standard names in your build directory, you better look up the make man page to see which takes precedence).

Best way to check if a character array is empty

if (!*text) {}  

The above dereferences the pointer 'text' and checks to see if it's zero. alternatively:

if (*text == 0) {} 

Maximum value of maxRequestLength?

2,147,483,647 bytes, since the value is a signed integer (Int32). That's probably more than you'll need.

How to convert an array of key-value tuples into an object

The new JS API for this is Object.fromEntries(array of tuples), it works with raw arrays and/or Maps

How do I reference a local image in React?

Step 1 : import MyIcon from './img/icon.png'

step 2 :

<img
    src={MyIcon}
    style={{width:'100%', height:'100%'}}
/>    

Determine command line working directory when running node bin script

Current Working Directory

To get the current working directory, you can use:

process.cwd()

However, be aware that some scripts, notably gulp, will change the current working directory with process.chdir().

Node Module Path

You can get the path of the current module with:

  • __filename
  • __dirname

Original Directory (where the command was initiated)

If you are running a script from the command line, and you want the original directory from which the script was run, regardless of what directory the script is currently operating in, you can use:

process.env.INIT_CWD

Original directory, when working with NPM scripts

It's sometimes desirable to run an NPM script in the current directory, rather than the root of the project.

This variable is available inside npm package scripts as:

$INIT_CWD.

You must be running a recent version of NPM. If this variable is not available, make sure NPM is up to date.

This will allow you access the current path in your package.json, e.g.:

scripts: {
  "customScript": "gulp customScript --path $INIT_CWD"
}

How to make a SIMPLE C++ Makefile

You had two options.

Option 1: simplest makefile = NO MAKEFILE.

Rename "a3driver.cpp" to "a3a.cpp", and then on the command line write:

nmake a3a.exe

And that's it. If you're using GNU Make, use "make" or "gmake" or whatever.

Option 2: a 2-line makefile.

a3a.exe: a3driver.obj
    link /out:a3a.exe a3driver.obj

Onclick event to remove default value in a text input field

HTML5 Placeholder Attribute

You are likely wanting placeholder functionality:

<input name="Name" placeholder="Enter Your Name" />

Polyfill for Older Browsers

This will not work in some older browsers, but polyfills exist (some require jQuery, others don't) to patch that functionality.

"Screw it, I'll do it myself."

If you wanted to roll your own solution, you could use the onfocus and onblur events of your element to determine what its value should be:

<input name="Name" value="Enter Your Name"
       onfocus="(this.value == 'Enter Your Name') && (this.value = '')"
       onblur="(this.value == '') && (this.value = 'Enter Your Name')" />

Avoid Mixing HTML with JavaScript

You'll find that most of us aren't big fans of evaluating JavaScript from attributes like onblur and onfocus. Instead, it's more commonly encouraged to bind this logic up purely with JavaScript. Granted, it's a bit more verbose, but it keeps a nice separation between your logic and your markup:

var nameElement = document.forms.myForm.Name;

function nameFocus( e ) {
  var element = e.target || window.event.srcElement;
  if (element.value == "Enter Your Name") element.value = "";
}

function nameBlur( e ) {
  var element = e.target || window.event.srcElement;
  if (element.value == "") element.value = "Enter Your Name";
}

if ( nameElement.addEventListener ) {
  nameElement.addEventListener("focus", nameFocus, false);
  nameElement.addEventListener("blur", nameBlur, false);
} else if ( nameElement.attachEvent ) {
  nameElement.attachEvent("onfocus", nameFocus);
  nameElement.attachEvent("onblur", nameBlur);
}

Demo: http://jsbin.com/azehum/2/edit

WaitAll vs WhenAll

While JonSkeet's answer explains the difference in a typically excellent way there is another difference: exception handling.

Task.WaitAll throws an AggregateException when any of the tasks throws and you can examine all thrown exceptions. The await in await Task.WhenAll unwraps the AggregateException and 'returns' only the first exception.

When the program below executes with await Task.WhenAll(taskArray) the output is as follows.

19/11/2016 12:18:37 AM: Task 1 started
19/11/2016 12:18:37 AM: Task 3 started
19/11/2016 12:18:37 AM: Task 2 started
Caught Exception in Main at 19/11/2016 12:18:40 AM: Task 1 throwing at 19/11/2016 12:18:38 AM
Done.

When the program below is executed with Task.WaitAll(taskArray) the output is as follows.

19/11/2016 12:19:29 AM: Task 1 started
19/11/2016 12:19:29 AM: Task 2 started
19/11/2016 12:19:29 AM: Task 3 started
Caught AggregateException in Main at 19/11/2016 12:19:32 AM: Task 1 throwing at 19/11/2016 12:19:30 AM
Caught AggregateException in Main at 19/11/2016 12:19:32 AM: Task 2 throwing at 19/11/2016 12:19:31 AM
Caught AggregateException in Main at 19/11/2016 12:19:32 AM: Task 3 throwing at 19/11/2016 12:19:32 AM
Done.

The program:

class MyAmazingProgram
{
    public class CustomException : Exception
    {
        public CustomException(String message) : base(message)
        { }
    }

    static void WaitAndThrow(int id, int waitInMs)
    {
        Console.WriteLine($"{DateTime.UtcNow}: Task {id} started");

        Thread.Sleep(waitInMs);
        throw new CustomException($"Task {id} throwing at {DateTime.UtcNow}");
    }

    static void Main(string[] args)
    {
        Task.Run(async () =>
        {
            await MyAmazingMethodAsync();
        }).Wait();

    }

    static async Task MyAmazingMethodAsync()
    {
        try
        {
            Task[] taskArray = { Task.Factory.StartNew(() => WaitAndThrow(1, 1000)),
                                 Task.Factory.StartNew(() => WaitAndThrow(2, 2000)),
                                 Task.Factory.StartNew(() => WaitAndThrow(3, 3000)) };

            Task.WaitAll(taskArray);
            //await Task.WhenAll(taskArray);
            Console.WriteLine("This isn't going to happen");
        }
        catch (AggregateException ex)
        {
            foreach (var inner in ex.InnerExceptions)
            {
                Console.WriteLine($"Caught AggregateException in Main at {DateTime.UtcNow}: " + inner.Message);
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Caught Exception in Main at {DateTime.UtcNow}: " + ex.Message);
        }
        Console.WriteLine("Done.");
        Console.ReadLine();
    }
}

CASE .. WHEN expression in Oracle SQL

You can only check the first character of the status. For this you use substring function.

substr(status, 1,1)

In your case past.

How do I view the SQL generated by the Entity Framework?

If you want to have parameter values (not only @p_linq_0 but also their values) too, you can use IDbCommandInterceptor and add some logging to ReaderExecuted method.

Export to xls using angularjs

I had this problem and I made a tool to export an HTML table to CSV file. The problem I had with FileSaver.js is that this tool grabs the table with html format, this is why some people can't open the file in excel or google. All you have to do is export the js file and then call the function. This is the github url https://github.com/snake404/tableToCSV if someone has the same problem.

Show constraints on tables command

Analogous to @Resh32, but without the need to use the USE statement:

SELECT TABLE_NAME,
       COLUMN_NAME,
       CONSTRAINT_NAME,
       REFERENCED_TABLE_NAME,
       REFERENCED_COLUMN_NAME
FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE TABLE_SCHEMA = "database_name" 
      AND TABLE_NAME = "table_name" 
      AND REFERENCED_COLUMN_NAME IS NOT NULL;

Useful, e.g. using the ORM.

What is the difference between HTTP_HOST and SERVER_NAME in PHP?

As balusC said SERVER_NAME is not reliable and can be changed in apache config , server name config of server and firewall that can be between you and server.

Following function always return real host (user typed host) without port and it's almost reliable:

function getRealHost(){
   list($realHost,)=explode(':',$_SERVER['HTTP_HOST']);
   return $realHost;
}

How do I get the coordinate position after using jQuery drag and drop?

I just made something like that (If I understand you correctly).

I use he function position() include in jQuery 1.3.2.

Just did a copy paste and a quick tweak... But should give you the idea.

// Make images draggable.
$(".item").draggable({

    // Find original position of dragged image.
    start: function(event, ui) {

        // Show start dragged position of image.
        var Startpos = $(this).position();
        $("div#start").text("START: \nLeft: "+ Startpos.left + "\nTop: " + Startpos.top);
    },

    // Find position where image is dropped.
    stop: function(event, ui) {

        // Show dropped position.
        var Stoppos = $(this).position();
        $("div#stop").text("STOP: \nLeft: "+ Stoppos.left + "\nTop: " + Stoppos.top);
    }
});

<div id="container">
    <img id="productid_1" src="images/pic1.jpg" class="item" alt="" title="" />
    <img id="productid_2" src="images/pic2.jpg" class="item" alt="" title="" />
    <img id="productid_3" src="images/pic3.jpg" class="item" alt="" title="" />
</div>

<div id="start">Waiting for dragging the image get started...</div>
<div id="stop">Waiting image getting dropped...</div>

What is the recommended way to delete a large number of items from DynamoDB?

According to the DynamoDB documentation you could just delete the full table.

See below:

"Deleting an entire table is significantly more efficient than removing items one-by-one, which essentially doubles the write throughput as you do as many delete operations as put operations"

If you wish to delete only a subset of your data, then you could make separate tables for each month, year or similar. This way you could remove "last month" and keep the rest of your data intact.

This is how you delete a table in Java using the AWS SDK:

DeleteTableRequest deleteTableRequest = new DeleteTableRequest()
  .withTableName(tableName);
DeleteTableResult result = client.deleteTable(deleteTableRequest);

How do you open a file in C++?

You need to use an ifstream if you just want to read (use an ofstream to write, or an fstream for both).

To open a file in text mode, do the following:

ifstream in("filename.ext", ios_base::in); // the in flag is optional

To open a file in binary mode, you just need to add the "binary" flag.

ifstream in2("filename2.ext", ios_base::in | ios_base::binary ); 

Use the ifstream.read() function to read a block of characters (in binary or text mode). Use the getline() function (it's global) to read an entire line.

How to import an excel file in to a MySQL database

Another useful tool, and as a MySQL front-end replacement, is Toad for MySQL. Sadly, no longer supported by Quest, but a brilliant IDE for MySQL, with IMPORT and EXPORT wizards, catering for most file types.

In SQL Server, how do I generate a CREATE TABLE statement for a given table?

I realise that it's been a very long time but thought I'd add anyway. If you just want the table, and not the create table statement you could use

select into x from db.schema.y where 1=0

to copy the table to a new DB

JavaScript function to add X months to a date

Simple solution: 2678400000 is 31 day in milliseconds

var oneMonthFromNow = new Date((+new Date) + 2678400000);

Update:

Use this data to build our own function:

  • 2678400000 - 31 day
  • 2592000000 - 30 days
  • 2505600000 - 29 days
  • 2419200000 - 28 days

How do I set a VB.Net ComboBox default value

Much simpler solution, Select the Combo-box, and in the option of Selected item, select the item index (0 for the first item) and set it to be the default value in the combo box.

Can I use a :before or :after pseudo-element on an input field?

The biggest misunderstanding here is the meaning of the words before and after. They do not refer to the element itself, but to the content in the element. So element:before is before the content, and element:after is after the content, but both are still inside the original element.

The input element has no content in the CSS view, and so has no :before or :after pseudo content. This is true of many other void or replaced elements.

There is no pseudo element referring to outside the element.

In a different universe, these pseudo elements might have been called something else to make this distinction clearer. And someone might even have proposed a pseudo element which is genuinely outside the element. So far, this is not the case in this universe.

How to use Ajax.ActionLink?

Sure, a very similar question was asked before. Set the controller for ajax requests:

public ActionResult Show()
{
    if (Request.IsAjaxRequest()) 
    {
        return PartialView("Your_partial_view", new Model());
    }
    else 
    {
        return View();
    }
}

Set the action link as wanted:

@Ajax.ActionLink("Show", 
                 "Show", 
                 null, 
                 new AjaxOptions { HttpMethod = "GET", 
                 InsertionMode = InsertionMode.Replace, 
                 UpdateTargetId = "dialog_window_id", 
                 OnComplete = "your_js_function();" })

Note that I'm using Razor view engine, and that your AjaxOptions may vary depending on what you want. Finally display it on a modal window. The jQuery UI dialog is suggested.

Is there a 'foreach' function in Python 3?

Here is the example of the "foreach" construction with simultaneous access to the element indexes in Python:

for idx, val in enumerate([3, 4, 5]):
    print (idx, val)

What's the shebang/hashbang (#!) in Facebook and new Twitter URLs for?

First of all: I'm the author of the The Single Page Interface Manifesto cited by raganwald

As raganwald has explained very well, the most important aspect of the Single Page Interface (SPI) approach used in FaceBook and Twitter is the use of hash # in URLs

The character ! is added only for Google purposes, this notation is a Google "standard" for crawling web sites intensive on AJAX (in the extreme Single Page Interface web sites). When Google's crawler finds an URL with #! it knows that an alternative conventional URL exists providing the same page "state" but in this case on load time.

In spite of #! combination is very interesting for SEO, is only supported by Google (as far I know), with some JavaScript tricks you can build SPI web sites SEO compatible for any web crawler (Yahoo, Bing...).

The SPI Manifesto and demos do not use Google's format of ! in hashes, this notation could be easily added and SPI crawling could be even easier (UPDATE: now ! notation is used and remains compatible with other search engines).

Take a look to this tutorial, is an example of a simple ItsNat SPI site but you can pick some ideas for other frameworks, this example is SEO compatible for any web crawler.

The hard problem is to generate any (or selected) "AJAX page state" as plain HTML for SEO, in ItsNat is very easy and automatic, the same site is in the same time SPI or page based for SEO (or when JavaScript is disabled for accessibility). With other web frameworks you can ever follow the double site approach, one site is SPI based and another page based for SEO, for instance Twitter uses this "double site" technique.

Unescape HTML entities in Javascript?

Matthias Bynens has a library for this: https://github.com/mathiasbynens/he

Example:

console.log(
    he.decode("J&#246;rg &amp J&#xFC;rgen rocked to &amp; fro ")
);
// Logs "Jörg & Jürgen rocked to & fro"

I suggest favouring it over hacks involving setting an element's HTML content and then reading back its text content. Such approaches can work, but are deceptively dangerous and present XSS opportunities if used on untrusted user input.

If you really can't bear to load in a library, you can use the textarea hack described in this answer to a near-duplicate question, which, unlike various similar approaches that have been suggested, has no security holes that I know of:

function decodeEntities(encodedString) {
    var textArea = document.createElement('textarea');
    textArea.innerHTML = encodedString;
    return textArea.value;
}

console.log(decodeEntities('1 &amp; 2')); // '1 & 2'

But take note of the security issues, affecting similar approaches to this one, that I list in the linked answer! This approach is a hack, and future changes to the permissible content of a textarea (or bugs in particular browsers) could lead to code that relies upon it suddenly having an XSS hole one day.

The source was not found, but some or all event logs could not be searched

I recently experienced the error, and none of the solutions worked for me. What resolved the error for me was adding the Application pool user to the Power Users group in computer management. I couldn't use the Administrator group due to a company policy.

How to turn off caching on Firefox?

After 2 hours of browsing for various alternatives, this is something that worked for me.

My requirement was disabling caching of js and css files in my spring secured web application. But at the same time caching these files "within" a particular session.

Passing a unique id with every request is one of the advised approaches.

And this is what I did :- Instead of

<script language="javascript" src="js/home.js"></script>

I used

<script language="javascript" src="js/home.js?id=${pageContext.session.id}"></script>

Any cons to the above approach are welcome. Security Issues ?

Cut off text in string after/before separator in powershell

$name -replace ";*",""

You were close, but you used the syntax of a wildcard expresson rather than a regular expression, which is what the -replace operator expects.

Therefore (hash sequence shortened):

PS> 'test.txt ; 131 136 80 89 119 17 60 123 210 121 188' -replace '\s*;.*'
test.txt

Note:

  • Omitting the substitution-text operand (the 2nd RHS operand) implicitly uses "" (the empty string), i.e. it effectively removes what the regex matched.

  • .* is what represents a potentially empty run (*) of characters (.) in a regex - it is the regex equivalent of * by itself in a wildcard expression.

  • Adding \s* before the ; in the regex also removes trailing whitespace (\s) after the filename.

  • I've used '...' rather than "..." to enclose the regex, so as to prevent confusion between what PowerShell expands up front (see expandable strings in PowerShell and what the .NET regex engine sees.

numpy: most efficient frequency counts for unique values in an array

Most of simple problems get complicated because simple functionality like order() in R that gives a statistical result in both and descending order is missing in various python libraries. But if we devise our thinking that all such statistical ordering and parameters in python are easily found in pandas, we can can result sooner than looking in 100 different places. Also, development of R and pandas go hand-in-hand because they were created for same purpose. To solve this problem I use following code that gets me by anywhere:

unique, counts = np.unique(x, return_counts=True)
d = {'unique':unique, 'counts':count}  # pass the list to a dictionary
df = pd.DataFrame(d) #dictionary object can be easily passed to make a dataframe
df.sort_values(by = 'count', ascending=False, inplace = True)
df = df.reset_index(drop=True) #optional only if you want to use it further

How do I write a for loop in bash

Bash 3.0+ can use this syntax:

for i in {1..10} ; do ... ; done

..which avoids spawning an external program to expand the sequence (such as seq 1 10).

Of course, this has the same problem as the for(()) solution, being tied to bash and even a particular version (if this matters to you).

pros and cons between os.path.exists vs os.path.isdir

os.path.exists(path) Returns True if path refers to an existing path. An existing path can be regular files (http://en.wikipedia.org/wiki/Unix_file_types#Regular_file), but also special files (e.g. a directory). So in essence this function returns true if the path provided exists in the filesystem in whatever form (notwithstanding a few exceptions such as broken symlinks).

os.path.isdir(path) in turn will only return true when the path points to a directory

Capturing "Delete" Keypress with jQuery

You shouldn't use the keypress event, but the keyup or keydown event because the keypress event is intended for real (printable) characters. keydown is handled at a lower level so it will capture all nonprinting keys like delete and enter.

Is it not possible to define multiple constructors in Python?

The easiest way is through keyword arguments:

class City():
  def __init__(self, city=None):
    pass

someCity = City(city="Berlin")

This is pretty basic stuff. Maybe look at the Python documentation?

Can RDP clients launch remote applications and not desktops

Another way is shown in this CodeProject article:

http://www.codeproject.com/KB/IP/tswindowclipper.aspx

The basic idea is to create a virutal channel that sends the windows position of the app(s) you want to show, then only render that part of the window on the client.

How to check existence of user-define table type in SQL Server 2008?

Following examples work for me, please note "is_user_defined" NOT "is_table_type"

IF TYPE_ID(N'idType') IS NULL
CREATE TYPE [dbo].[idType] FROM Bigint NOT NULL
go

IF not EXISTS (SELECT * FROM sys.types WHERE is_user_defined = 1 AND name = 'idType')
CREATE TYPE [dbo].[idType] FROM Bigint NOT NULL
go

Which mime type should I use for mp3

The standard way is to use audio/mpeg which is something like this in your PHP header function ...

header('Content-Type: audio/mpeg');

Should I use "camel case" or underscores in python?

PEP 8 advises the first form for readability. You can find it here.

Function names should be lowercase, with words separated by underscores as necessary to improve readability.

Read XML file using javascript

The code below will convert any XMLObject or string to a native JavaScript object. Then you can walk on the object to extract any value you want.

/**
 * Tries to convert a given XML data to a native JavaScript object by traversing the DOM tree.
 * If a string is given, it first tries to create an XMLDomElement from the given string.
 * 
 * @param {XMLDomElement|String} source The XML string or the XMLDomElement prefreably which containts the necessary data for the object.
 * @param {Boolean} [includeRoot] Whether the "required" main container node should be a part of the resultant object or not.
 * @return {Object} The native JavaScript object which is contructed from the given XML data or false if any error occured.
 */
Object.fromXML = function( source, includeRoot ) {
    if( typeof source == 'string' )
    {
        try
        {
            if ( window.DOMParser )
                source = ( new DOMParser() ).parseFromString( source, "application/xml" );
            else if( window.ActiveXObject )
            {
                var xmlObject = new ActiveXObject( "Microsoft.XMLDOM" );
                xmlObject.async = false;
                xmlObject.loadXML( source );
                source = xmlObject;
                xmlObject = undefined;
            }
            else
                throw new Error( "Cannot find an XML parser!" );
        }
        catch( error )
        {
            return false;
        }
    }

    var result = {};

    if( source.nodeType == 9 )
        source = source.firstChild;
    if( !includeRoot )
        source = source.firstChild;

    while( source ) {
        if( source.childNodes.length ) {
            if( source.tagName in result ) {
                if( result[source.tagName].constructor != Array ) 
                    result[source.tagName] = [result[source.tagName]];
                result[source.tagName].push( Object.fromXML( source ) );
            }
            else 
                result[source.tagName] = Object.fromXML( source );
        } else if( source.tagName )
            result[source.tagName] = source.nodeValue;
        else if( !source.nextSibling ) {
            if( source.nodeValue.clean() != "" ) {
                result = source.nodeValue.clean();
            }
        }
        source = source.nextSibling;
    }
    return result;
};

String.prototype.clean = function() {
    var self = this;
    return this.replace(/(\r\n|\n|\r)/gm, "").replace(/^\s+|\s+$/g, "");
}

Bootstrap navbar Active State not working

Add this JavaScript on your main js file.

$(".navbar a").on("click", function(){
      $(".navbar").find(".active").removeClass("active");
      $(this).parent().addClass("active");
    });

Python 3 - ValueError: not enough values to unpack (expected 3, got 2)

In this line:

for name, email, lastname in unpaidMembers.items():

unpaidMembers.items() must have only two values per iteration.

Here is a small example to illustrate the problem:

This will work:

for alpha, beta, delta in [("first", "second", "third")]:
    print("alpha:", alpha, "beta:", beta, "delta:", delta)

This will fail, and is what your code does:

for alpha, beta, delta in [("first", "second")]:
    print("alpha:", alpha, "beta:", beta, "delta:", delta)

In this last example, what value in the list is assigned to delta? Nothing, There aren't enough values, and that is the problem.

CSS: styled a checkbox to look like a button, is there a hover?

Do what Kelly said...

BUT. Instead of having the input positioned absolute and top -20px (just hiding it off the page), make the input box hidden.

example:

<input type="checkbox" hidden> 

Works better and can put it anywhere on the page.

What are valid values for the id attribute in HTML?

  1. IDs are best suited for naming parts of your layout so should not give same name for ID and class
  2. ID allows alphanumeric and special characters
  3. but avoid using of # : . * ! symbols
  4. not allowed spaces
  5. not started with numbers or a hyphen followed by a digit
  6. case sensitive
  7. using ID selectors is faster than using class selectors
  8. use hyphen "-" (underscore "_" can also use but not good for seo) for long CSS class or Id rule names
  9. If a rule has an ID selector as its key selector, don’t add the tag name to the rule. Since IDs are unique, adding a tag name would slow down the matching process needlessly.
  10. In HTML5, the id attribute can be used on any HTML element and In HTML 4.01, the id attribute cannot be used with: <base>, <head>, <html>, <meta>, <param>, <script>, <style>, and <title>.

Getting full JS autocompletion under Sublime Text

There are three approaches

  • Use SublimeCodeIntel plug-in

  • Use CTags plug-in

  • Generate .sublime-completion file manually

Approaches are described in detail in this blog post (of mine): http://opensourcehacker.com/2013/03/04/javascript-autocompletions-and-having-one-for-sublime-text-2/

What is the bit size of long on 64-bit Windows?

In the Unix world, there were a few possible arrangements for the sizes of integers and pointers for 64-bit platforms. The two mostly widely used were ILP64 (actually, only a very few examples of this; Cray was one such) and LP64 (for almost everything else). The acronynms come from 'int, long, pointers are 64-bit' and 'long, pointers are 64-bit'.

Type           ILP64   LP64   LLP64
char              8      8       8
short            16     16      16
int              64     32      32
long             64     64      32
long long        64     64      64
pointer          64     64      64

The ILP64 system was abandoned in favour of LP64 (that is, almost all later entrants used LP64, based on the recommendations of the Aspen group; only systems with a long heritage of 64-bit operation use a different scheme). All modern 64-bit Unix systems use LP64. MacOS X and Linux are both modern 64-bit systems.

Microsoft uses a different scheme for transitioning to 64-bit: LLP64 ('long long, pointers are 64-bit'). This has the merit of meaning that 32-bit software can be recompiled without change. It has the demerit of being different from what everyone else does, and also requires code to be revised to exploit 64-bit capacities. There always was revision necessary; it was just a different set of revisions from the ones needed on Unix platforms.

If you design your software around platform-neutral integer type names, probably using the C99 <inttypes.h> header, which, when the types are available on the platform, provides, in signed (listed) and unsigned (not listed; prefix with 'u'):

  • int8_t - 8-bit integers
  • int16_t - 16-bit integers
  • int32_t - 32-bit integers
  • int64_t - 64-bit integers
  • uintptr_t - unsigned integers big enough to hold pointers
  • intmax_t - biggest size of integer on the platform (might be larger than int64_t)

You can then code your application using these types where it matters, and being very careful with system types (which might be different). There is an intptr_t type - a signed integer type for holding pointers; you should plan on not using it, or only using it as the result of a subtraction of two uintptr_t values (ptrdiff_t).

But, as the question points out (in disbelief), there are different systems for the sizes of the integer data types on 64-bit machines. Get used to it; the world isn't going to change.

Converting HTML to PDF using PHP?

If you wish to create a pdf from php, pdflib will help you (as some others suggested).

Else, if you want to convert an HTML page to PDF via PHP, you'll find a little trouble outta here.. For 3 years I've been trying to do it as best as I can.

So, the options I know are:

DOMPDF : php class that wraps the html and builds the pdf. Works good, customizable (if you know php), based on pdflib, if I remember right it takes even some CSS. Bad news: slow when the html is big or complex.

HTML2PS: same as DOMPDF, but this one converts first to a .ps (ghostscript) file, then, to whatever format you need (pdf, jpg, png). For me is little better than dompdf, but has the same speed problem.. but, better compatibility with CSS.

Those two are php classes, but if you can install some software on the server, and access it throught passthru() or system(), give a look to these too:

wkhtmltopdf: based on webkit (safari's wrapper), is really fast and powerful.. seems like this is the best one (atm) for converting html pages to pdf on the fly; taking only 2 seconds for a 3 page xHTML document with CSS2. It is a recent project, anyway, the google.code page is often updated.

htmldoc : This one is a tank, it never really stops/crashes.. the project looks dead since 2007, but anyway if you don't need CSS compatibility this can be nice for you.

Detect browser or tab closing

window.onbeforeunload = function() {
  console.log('event');
  return false; //here also can be string, that will be shown to the user
}

Detecting IE11 using CSS Capability/Feature Detection

You should use Modernizr, it will add a class to the body tag.

also:

function getIeVersion()
{
  var rv = -1;
  if (navigator.appName == 'Microsoft Internet Explorer')
  {
    var ua = navigator.userAgent;
    var re  = new RegExp("MSIE ([0-9]{1,}[\.0-9]{0,})");
    if (re.exec(ua) != null)
      rv = parseFloat( RegExp.$1 );
  }
  else if (navigator.appName == 'Netscape')
  {
    var ua = navigator.userAgent;
    var re  = new RegExp("Trident/.*rv:([0-9]{1,}[\.0-9]{0,})");
    if (re.exec(ua) != null)
      rv = parseFloat( RegExp.$1 );
  }
  return rv;
}

Note that IE11 is still is in preview, and the user agent may change before release.

The User-agent string for IE 11 is currently this one :

Mozilla/5.0 (Windows NT 6.3; Trident/7.0; rv 11.0) like Gecko

Which means your can simply test, for versions 11.xx,

var isIE11 = !!navigator.userAgent.match(/Trident.*rv 11\./)

What is a NullReferenceException, and how do I fix it?

Literally the easiest way to fix a NullReferenceExeption has two ways. If you have a GameObject for example with a script attached and a variable named rb (rigidbody) this variable will start null when you start your game.
This is why you get a NullReferenceExeption because the computer does not have data stored in that variable.

I'll be using a RigidBody variable as an example.
We can add data really easily actually in a few ways:

  1. Add a RigidBody to your object with AddComponent > Physics > Rigidbody
    Then go into your script and type rb = GetComponent<Rigidbody>();
    This line of code works best under your Start() or Awake() functions.
  2. You can add a component programmatically and assign the variable at the same time with one line of code: rb = AddComponent<RigidBody>();

Further Notes: If you want unity to add a component to your object and you might have forgotten to add one, you can type [RequireComponent(typeof(RigidBody))] above your class declaration (the space below all of your usings).
Enjoy and have fun making games!

Importing packages in Java

For the second class file, add "package Dan;" like the first one, so as to make sure they are in the same package; modify "import Dan.Vik.disp;" to be "import Dan.Vik;"

How do I center text horizontally and vertically in a TextView?

android:gravity="centre" 

This would help you to centre the textview.

Does Spring Data JPA have any way to count entites using method name resolving?

According to the issue DATAJPA-231 the feature is not implemented yet.

fatal error LNK1169: one or more multiply defined symbols found in game programming

just add /FORCE as linker flag and you're all set.

for instance, if you're working on CMakeLists.txt. Then add following line:

SET(CMAKE_EXE_LINKER_FLAGS  "/FORCE")

REST API - Bulk Create or Update in single request

PUT ing

PUT /binders/{id}/docs Create or update, and relate a single document to a binder

e.g.:

PUT /binders/1/docs HTTP/1.1
{
  "docNumber" : 1
}

PATCH ing

PATCH /docs Create docs if they do not exist and relate them to binders

e.g.:

PATCH /docs HTTP/1.1
[
    { "op" : "add", "path" : "/binder/1/docs", "value" : { "doc_number" : 1 } },
    { "op" : "add", "path" : "/binder/8/docs", "value" : { "doc_number" : 8 } },
    { "op" : "add", "path" : "/binder/3/docs", "value" : { "doc_number" : 6 } }
] 

I'll include additional insights later, but in the meantime if you want to, have a look at RFC 5789, RFC 6902 and William Durand's Please. Don't Patch Like an Idiot blog entry.

Use of min and max functions in C++

Couldn't a C++ implementation targeted for processors with SSE instructions provide specializations of std::min and std::max for types float, double, and long double which do the equivalent of fminf, fmin, and fminl, respectively?

The specializations would provide better performance for floating-point types while the general template would handle non-floating-point types without attempting to coerce floating-point types into floating-point types that way the fmins and fmaxes would.

Set NOW() as Default Value for datetime datatype?

ALTER TABLE table_name
  CHANGE COLUMN date_column_name date_column_name DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP;

Finally, This worked for me!

batch script - read line by line

Try this:

@echo off
for /f "tokens=*" %%a in (input.txt) do (
  echo line=%%a
)
pause

because of the tokens=* everything is captured into %a

edit: to reply to your comment, you would have to do that this way:

@echo off
for /f "tokens=*" %%a in (input.txt) do call :processline %%a

pause
goto :eof

:processline
echo line=%*

goto :eof

:eof

Because of the spaces, you can't use %1, because that would only contain the part until the first space. And because the line contains quotes, you can also not use :processline "%%a" in combination with %~1. So you need to use %* which gets %1 %2 %3 ..., so the whole line.

remove table row with specific id

Try

$('table#test tr#3').remove();

C# 'or' operator?

Or is || in C#.

You may have a look at this.

Object passed as parameter to another class, by value or reference?

In general, an "object" is an instance of a class, which is an "image"/"fingerprint" of a class created in memory (via New keyword).
The variable of object type refers to this memory location, that is, it essentially contains the address in memory.
So a parameter of object type passes a reference/"link" to an object, not a copy of the whole object.

The project cannot be built until the build path errors are resolved.

This is what worked for me:

  1. Go to ~/.m2/repository and deleted everything there by running rm -rf. Make sure everything is deleted.
  2. Re-launch eclipse or STS
  3. Right click on project -> Maven -> update project.

What is the Java ?: operator called and what does it do?

condition ? truth : false;

If the condition is true then evaluate the first expression. If the condition is false, evaluate the second expression.

It is called the Conditional Operator and it is a type of Ternary Operation.

How do I find the duplicates in a list and create another list with them?

There are a lot of answers up here, but I think this is relatively a very readable and easy to understand approach:

def get_duplicates(sorted_list):
    duplicates = []
    last = sorted_list[0]
    for x in sorted_list[1:]:
        if x == last:
            duplicates.append(x)
        last = x
    return set(duplicates)

Notes:

  • If you wish to preserve duplication count, get rid of the cast to 'set' at the bottom to get the full list
  • If you prefer to use generators, replace duplicates.append(x) with yield x and the return statement at the bottom (you can cast to set later)

How do I query for all dates greater than a certain date in SQL Server?

We can use like below as well

SELECT * 
FROM dbo.March2010 A
WHERE CAST(A.Date AS Date) >= '2017-03-22';

SELECT * 
    FROM dbo.March2010 A
    WHERE CAST(A.Date AS Datetime) >= '2017-03-22 06:49:53.840';

How to append a jQuery variable value inside the .html tag

See this Link

HTML

<div id="products"></div>

JS

var someone = {
"name":"Mahmoude Elghandour",
"price":"174 SR",
"desc":"WE Will BE WITH YOU"
 };
 var name = $("<div/>",{"text":someone.name,"class":"name"
});

var price = $("<div/>",{"text":someone.price,"class":"price"});
var desc = $("<div />", {   
"text": someone.desc,
"class": "desc"
});
$("#products").fadeIn(1500);
$("#products").append(name).append(price).append(desc);

How to get page content using cURL?

Try This:

$url = "http://www.google.com/search?q=".$strSearch."&hl=en&start=0&sa=N";
  $ch = curl_init();
  curl_setopt($ch, CURLOPT_HEADER, 0);
  curl_setopt($ch, CURLOPT_VERBOSE, 0);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
  curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/4.0 (compatible;)");
  curl_setopt($ch, CURLOPT_URL, urlencode($url));
  $response = curl_exec($ch);
  curl_close($ch);

How to import a module given its name as string?

The below piece worked for me:

>>>import imp; 
>>>fp, pathname, description = imp.find_module("/home/test_module"); 
>>>test_module = imp.load_module("test_module", fp, pathname, description);
>>>print test_module.print_hello();

if you want to import in shell-script:

python -c '<above entire code in one line>'

What is the easiest way to encrypt a password when I save it to the registry?

You don't decrypt authentication passwords!

Hash them using something like the SHA256 provider and when you have to challenge, hash the input from the user and see if the two hashes match.

byte[] data = System.Text.Encoding.ASCII.GetBytes(inputString);
data = new System.Security.Cryptography.SHA256Managed().ComputeHash(data);
String hash = System.Text.Encoding.ASCII.GetString(data);

Leaving passwords reversible is a really horrible model.

Edit2: I thought we were just talking about front-line authentication. Sure there are cases where you want to encrypt passwords for other things that need to be reversible but there should be a 1-way lock on top of it all (with a very few exceptions).

I've upgraded the hashing algorithm but for the best possible strength you want to keep a private salt and add that to your input before hashing it. You would do this again when you compare. This adds another layer making it even harder for somebody to reverse.

Transparent color of Bootstrap-3 Navbar

.navbar {
   background-color: transparent;
   background: transparent;
   border-color: transparent;
}

.navbar li { color: #000 } 

http://bootply.com/106969

What is the difference between "Rollback..." and "Back Out Submitted Changelist #####" in Perforce P4V

At its simplest, the difference is one of plurality:

  • Backout backs out of a single changelist (whether the most recent or not). i.e. it undoes a single changelist.
  • Rollback rolls back changes as much as it needs to in order to get to a previous changelist. i.e. it undoes multiple changelists.

I used to forget which one is which and end up having to look it up many times. To fix this problem, imagine rolling back as several rotations then hopefully the fact that rollback is plural will help you (and me!) remember which one is which. Backout sounds 'less plural' than rollback to me. Imagine backing out of a single parking space.

So, the mnemonic is:

  • Rollback → multiple rotations
  • Backout → back out of a single car parking space

I hope this helps!

Does Enter key trigger a click event?

For angular 6 there is a new way of doing it. On your input tag add

(keyup.enter)="keyUpFunction($event)"

Where keyUpFunction($event) is your function.

error: package javax.servlet does not exist

I needed to import javaee-api as well.

  <dependency>
     <groupId>javax</groupId>
     <artifactId>javaee-api</artifactId>
     <version>7.0</version>
  </dependency>

Unless I got following error:

package javax.servlet.http does not exist
javax.servlet.annotation does not exist
javax.servlet.http does not exist
...

Excel VBA Macro: User Defined Type Not Defined

Sub DeleteEmptyRows()  

    Worksheets("YourSheetName").Activate
    On Error Resume Next
    Columns("A").SpecialCells(xlCellTypeBlanks).EntireRow.Delete

End Sub

The following code will delete all rows on a sheet(YourSheetName) where the content of Column A is blank.

EDIT: User Defined Type Not Defined is caused by "oTable As Table" and "oRow As Row". Replace Table and Row with Object to resolve the error and make it compile.

Escaping Strings in JavaScript

You can also use this

_x000D_
_x000D_
let str = "hello single ' double \" and slash \\ yippie";

let escapeStr = escape(str);
document.write("<b>str : </b>"+str);
document.write("<br/><b>escapeStr : </b>"+escapeStr);
document.write("<br/><b>unEscapeStr : </b> "+unescape(escapeStr));
_x000D_
_x000D_
_x000D_

How to get the current TimeStamp?

I think you are looking for this function:

http://doc.qt.io/qt-5/qdatetime.html#toTime_t

uint QDateTime::toTime_t () const

Returns the datetime as the number of seconds that have passed since 1970-01-01T00:00:00, > Coordinated Universal Time (Qt::UTC).

On systems that do not support time zones, this function will behave as if local time were Qt::UTC.

See also setTime_t().

AngularJS event on window innerWidth size change

If Khanh TO's solution caused UI issues for you (like it did for me) try using $timeout to not update the attribute until it has been unchanged for 500ms.

var oldWidth = window.innerWidth;
$(window).on('resize.doResize', function () {
    var newWidth = window.innerWidth,
        updateStuffTimer;

    if (newWidth !== oldWidth) {
        $timeout.cancel(updateStuffTimer);
    }

    updateStuffTimer = $timeout(function() {
         updateStuff(newWidth); // Update the attribute based on window.innerWidth
    }, 500);
});

$scope.$on('$destroy',function (){
    $(window).off('resize.doResize'); // remove the handler added earlier
});

Reference: https://gist.github.com/tommaitland/7579618

jQuery - Increase the value of a counter when a button is clicked

I'm going to try this the following way. I've placed the count variable inside the "onfocus" function so as to keep it from becoming a global variable. The idea is to create a counter for each image in a tumblr blog.

$(document).ready(function() {

  $("#image1").onfocus(function() {

  var count;

    if (count == undefined || count == "" || count == 0) {
    var count = 0;
    }

    count++;
    $("#counter1").html("Image Views: " + count);
  }
});

Then, outside the script tags and in the desired place in the body I'll add:

<div id="counter1"></div>

Install pip in docker

You might want to change the DNS settings of the Docker daemon. You can edit (or create) the configuration file at /etc/docker/daemon.json with the dns key, as

{
    "dns": ["your_dns_address", "8.8.8.8"]
}

In the example above, the first element of the list is the address of your DNS server. The second item is the Google’s DNS which can be used when the first one is not available.

Before proceeding, save daemon.json and restart the docker service.

sudo service docker restart

Once fixed, retry to run the build command.

java.net.SocketException: Connection reset

In my experience, I often encounter the following situations;

  1. If you work in a corporate company, contact the network and security team. Because in requests made to external services, it may be necessary to give permission for the relevant endpoint.

  2. Another issue is that the SSL certificate may have expired on the server where your application is running.

Open an html page in default browser with VBA?

I find the most simple is

shell "explorer.exe URL"

This also works to open local folders.

How to get the first element of the List or Set?

This is not an exact answer to this question, but in case the objects should be sorted SortedSet has a first() method:

SortedSet<String> sortedSet = new TreeSet<String>();
sortedSet.add("2");
sortedSet.add("1");
sortedSet.add("3");
String first = sortedSet.first(); //first="1"

The sorted objects must implement the Comparable interface (like String does)

From an array of objects, extract value of a property as array

Example to collect the different fields from the object array

_x000D_
_x000D_
let inputArray = [
  { id: 1, name: "name1", value: "value1" },
  { id: 2, name: "name2", value: "value2" },
];

let ids = inputArray.map( (item) => item.id);
let names = inputArray.map((item) => item.name);
let values = inputArray.map((item) => item.value);

console.log(ids);
console.log(names);
console.log(values);
_x000D_
_x000D_
_x000D_

Result :

[ 1, 2 ]
[ 'name1', 'name2' ]
[ 'value1', 'value2' ]

Listing only directories in UNIX

If I have this directory:

ls -l

lrwxrwxrwx  1 nagios nagios     11 août   2 18:46 conf_nagios -> /etc/icinga
-rw-------  1 nagios nagios 724930 août  15 21:00 dead.letter
-rw-r--r--  1 nagios nagios  12312 août  23 00:13 icinga.log
-rw-r--r--  1 nagios nagios   8323 août  23 00:12 icinga.log.gz
drwxr-xr-x  2 nagios nagios   4096 août  23 16:36 tmp

To get all directories, use -L to resolve links:

ls -lL | grep '^d'

drwxr-xr-x 5 nagios nagios   4096 août  15 21:22 conf_nagios
drwxr-xr-x 2 nagios nagios   4096 août  23 16:41 tmp

Without -L:

ls -l | grep '^d'

drwxr-xr-x 2 nagios nagios   4096 août  23 16:41 tmp

conf_nagios directory is missing.

The Web Application Project [...] is configured to use IIS. The Web server [...] could not be found.

I had this error, too. I thought everything was setup correctly, but I found out that one thing was missing: The host name I used for my project was not (yet) resolvable.

Since my app determines the current client's name from the host name I used a host name like clientname.mysuperapp.local for development. When I added the development host name to my hosts file, the project was loadable again. Obviously, I had to this anyway, but I haven't thought that VS checks the host name before loading the project.

WELD-001408: Unsatisfied dependencies for type Customer with qualifiers @Default

I had the same problem but it had nothing to do with annotations. The problem happened while indexing beans in my container (Jboss EAP 6.3). One of my beans could not be indexed because it used Java 8 features an I got this sneaky little warning while deploying:

WARN [org.jboss.as.server.deployment] ... Could not index class ... java.lang.IllegalStateException: Unknown tag! pos=20 poolCount = 133

Then at the injection point I got the error:

Unsatisfied dependencies for type ... with qualifiers @Default

The solution is to update the Java annotations index. download new version of jandex (jandex-1.2.3.Final or newer) then put it into

JBOSS_HOME\modules\system\layers\base\org\jboss\jandex\main and then update reference to the new file in module.xml

NOTE: EAP 6.4.x already have this fixed

How to compare 2 dataTables

If you were returning a DataTable as a function you could:

DataTable dataTable1; // Load with data
DataTable dataTable2; // Load with data (same schema)

// Fast check for row count equality.
if ( dataTable1.Rows.Count != dataTable2.Rows.Count) {
    return true;
}

var differences =
    dataTable1.AsEnumerable().Except(dataTable2.AsEnumerable(),
                                            DataRowComparer.Default);

return differences.Any() ? differences.CopyToDataTable() : new DataTable();

How can I get the MAC and the IP address of a connected client in PHP?

I don't think you can get MAC address in PHP, but you can get IP from $_SERVER['REMOTE_ADDR'] variable.

Git status ignore line endings / identical files / windows & linux environment / dropbox / mled

Issue related to git commands on Windows operating system:

$ git add --all

warning: LF will be replaced by CRLF in ...

The file will have its original line endings in your working directory.

Resolution:

$ git config --global core.autocrlf false     
$ git add --all 

No any warning messages come up.

Error: Cannot pull with rebase: You have unstaged changes

You can always do

git fetch && git merge --ff-only origin/master

and you will either get (a) no change if you have uncommitted changes that conflict with upstream changes or (b) the same effect as stash/pull/apply: a rebase to put you on the latest changes from HEAD and your uncommitted changes left as is.

Winforms issue - Error creating window handle

This problem is almost always related to the GDI Object count, User Object count or Handle count and usually not because of an out-of-memory condition on your machine.

When I am tracking one of these bugs, I open ProcessExplorer and watch these columns: Handles, Threads, GDI Objects, USER Objects, Private Bytes, Virtual Size and Working Set.

(In my experience, the problem is usually an object leak due to an event handler holding the object and preventing it from being disposed.)

Declare an array in TypeScript

Specific type of array in typescript

export class RegisterFormComponent 
{
     genders = new Array<GenderType>();   // Use any array supports different kind objects

     loadGenders()
     {
        this.genders.push({name: "Male",isoCode: 1});
        this.genders.push({name: "FeMale",isoCode: 2});
     }
}

type GenderType = { name: string, isoCode: number };    // Specified format

Disable a textbox using CSS

Just try this.

<asp:TextBox ID="tb" onkeypress="javascript:return false;" width="50px" runat="server"></asp:TextBox>

This won't allow any characters to be entered inside the TextBox.

Benefits of inline functions in C++?

Advantages

  • By inlining your code where it is needed, your program will spend less time in the function call and return parts. It is supposed to make your code go faster, even as it goes larger (see below). Inlining trivial accessors could be an example of effective inlining.
  • By marking it as inline, you can put a function definition in a header file (i.e. it can be included in multiple compilation unit, without the linker complaining)

Disadvantages

  • It can make your code larger (i.e. if you use inline for non-trivial functions). As such, it could provoke paging and defeat optimizations from the compiler.
  • It slightly breaks your encapsulation because it exposes the internal of your object processing (but then, every "private" member would, too). This means you must not use inlining in a PImpl pattern.
  • It slightly breaks your encapsulation 2: C++ inlining is resolved at compile time. Which means that should you change the code of the inlined function, you would need to recompile all the code using it to be sure it will be updated (for the same reason, I avoid default values for function parameters)
  • When used in a header, it makes your header file larger, and thus, will dilute interesting informations (like the list of a class methods) with code the user don't care about (this is the reason that I declare inlined functions inside a class, but will define it in an header after the class body, and never inside the class body).

Inlining Magic

  • The compiler may or may not inline the functions you marked as inline; it may also decide to inline functions not marked as inline at compilation or linking time.
  • Inline works like a copy/paste controlled by the compiler, which is quite different from a pre-processor macro: The macro will be forcibly inlined, will pollute all the namespaces and code, won't be easily debuggable, and will be done even if the compiler would have ruled it as inefficient.
  • Every method of a class defined inside the body of the class itself is considered as "inlined" (even if the compiler can still decide to not inline it
  • Virtual methods are not supposed to be inlinable. Still, sometimes, when the compiler can know for sure the type of the object (i.e. the object was declared and constructed inside the same function body), even a virtual function will be inlined because the compiler knows exactly the type of the object.
  • Template methods/functions are not always inlined (their presence in an header will not make them automatically inline).
  • The next step after "inline" is template metaprograming . I.e. By "inlining" your code at compile time, sometimes, the compiler can deduce the final result of a function... So a complex algorithm can sometimes be reduced to a kind of return 42 ; statement. This is for me extreme inlining. It happens rarely in real life, it makes compilation time longer, will not bloat your code, and will make your code faster. But like the grail, don't try to apply it everywhere because most processing cannot be resolved this way... Still, this is cool anyway...
    :-p

Stop node.js program from command line

If you want to stop your server with npm stop or something like this. You can write the code that kill your server process as:

require('child_process').exec(`kill -9 ${pid}`)

Check this link for the detail: https://gist.github.com/dominhhai/aa7f3314ad27e2c50fd5

c - warning: implicit declaration of function ‘printf’

You need to include a declaration of the printf() function.

#include <stdio.h>

How to add an existing folder with files to SVN?

I don't use commands. You should be able to do this using the GUI:

  • Right-click an empty space in your My Documents folder, select TortoiseSVN > Repo-browser.
  • Enter http://subversion... (your URL path to your Subversion server/directory you will save to) as your path and select OK
  • Right-click the root directory in Repo and select Add folder. Give it the name of your project and create it.
  • Right-click the project folder in the Repo-browser and select Checkout. The Checkout directory will be your Visual Studio\Projects\{your project} folder. Select OK.
  • You will receive a warning that the folder is not empty. Say Yes to checkout/export to that folder - it will not overwrite your project files.
  • Open your project folder. You will see question marks on folders that are associated with your VS project that have not yet been added to Subversion. Select those folders using Ctrl + Click, then right-click one of the selected items and select TortoiseSVN > Add
  • Select OK on the prompt
  • Your files should add. Select OK on the Add Finished! dialog
  • Right-click in an empty area of the folder and select Refresh. You’ll see “+” icons on the folders/files, now
  • Right-click an empty area in the folder once again and select SVN Commit
  • Add a message regarding what you are committing and click OK

phpMyAdmin access denied for user 'root'@'localhost' (using password: NO)

Just do what the message is asking for, create the user pma@localhost in the phpMyAdmin panel with no password

How to Change Font Size in drawString Java

All you need to do is this: click on (window) on the dropdown manue on top of your screen. click on (Editor). click on (zoom in) as many times as you need to.

In Java, how can I determine if a char array contains a particular character?

You can iterate through the array or you can convert it to a String and use indexOf.

if (new String(charArray).indexOf('q') < 0) {
    break;
}

Creating a new String is a bit wasteful, but it's probably the tersest code. You can also write a method to imitate the effect without incurring the overhead.

Apache Spark: map vs mapPartitions?

Map:

Map transformation.

The map works on a single Row at a time.

Map returns after each input Row.

The map doesn’t hold the output result in Memory.

Map no way to figure out then to end the service.

// map example

val dfList = (1 to 100) toList

val df = dfList.toDF()

val dfInt = df.map(x => x.getInt(0)+2)

display(dfInt)

MapPartition:

MapPartition transformation.

MapPartition works on a partition at a time.

MapPartition returns after processing all the rows in the partition.

MapPartition output is retained in memory, as it can return after processing all the rows in a particular partition.

MapPartition service can be shut down before returning.

// MapPartition example

Val dfList = (1 to 100) toList

Val df = dfList.toDF()

Val df1 = df.repartition(4).rdd.mapPartition((int) => Iterator(itr.length))

Df1.collec()

//display(df1.collect())

For more details, please refer to the Spark map vs mapPartitions transformation article.

Hope this is helpful!

Spark dataframe: collect () vs select ()

calling select will result is lazy evaluation: for example:

val df1 = df.select("col1")
val df2 = df1.filter("col1 == 3")

both above statements create lazy path that will be executed when you call action on that df, such as show, collect etc.

val df3 = df2.collect()

use .explain at the end of your transformation to follow its plan here is more detailed info Transformations and Actions

I am receiving warning in Facebook Application using PHP SDK

You need to ensure that any code that modifies the HTTP headers is executed before the headers are sent. This includes statements like session_start(). The headers will be sent automatically when any HTML is output.

Your problem here is that you're sending the HTML ouput at the top of your page before you've executed any PHP at all.

Move the session_start() to the top of your document :

<?php    session_start(); ?> <html> <head> <title>PHP SDK</title> </head> <body> <?php require_once 'src/facebook.php';    // more PHP code here. 

In c++ what does a tilde "~" before a function name signify?

It's the destructor. This method is called when the instance of your class is destroyed:

Stack<int> *stack= new Stack<int>;
//do something
delete stack; //<- destructor is called here;

Apply CSS Style to child elements

As far as I know this:

div[class=yourclass] table {  your style here; } 

or in your case even this:

div.yourclass table { your style here; }

(but this will work for elements with yourclass that might not be divs) will affect only tables inside yourclass. And, as Ken says, the > is not supported everywhere (and div[class=yourclass] too, so use the point notation for classes).

How to run Node.js as a background process and never die?

Simple solution (if you are not interested in coming back to the process, just want it to keep running):

nohup node server.js &

There's also the jobs command to see an indexed list of those backgrounded processes. And you can kill a backgrounded process by running kill %1 or kill %2 with the number being the index of the process.

Powerful solution (allows you to reconnect to the process if it is interactive):

screen

You can then detach by pressing Ctrl+a+d and then attach back by running screen -r

Also consider the newer alternative to screen, tmux.

Why should hash functions use a prime number modulus?

It depends on the choice of hash function.

Many hash functions combine the various elements in the data by multiplying them with some factors modulo the power of two corresponding to the word size of the machine (that modulus is free by just letting the calculation overflow).

You don't want any common factor between a multiplier for a data element and the size of the hash table, because then it could happen that varying the data element doesn't spread the data over the whole table. If you choose a prime for the size of the table such a common factor is highly unlikely.

On the other hand, those factors are usually made up from odd primes, so you should also be safe using powers of two for your hash table (e.g. Eclipse uses 31 when it generates the Java hashCode() method).

getResourceAsStream() is always returning null

I think this way you can get the file from "anywhere" (including server locations) and you do not need to care about where to put it.

It's usually a bad practice having to care about such things.

Thread.currentThread().getContextClassLoader().getResourceAsStream("abc.properties");

regex with space and letters only?

$('#input').on('keyup', function() {
     var RegExpression = /^[a-zA-Z\s]*$/;  
     ...

});

\s will allow the space

Streaming Audio from A URL in Android using MediaPlayer?

Looking my projects:

  1. https://github.com/master255/ImmortalPlayer http/FTP support, One thread to read, send and save to cache data. Most simplest way and most fastest work. Complex logic - best way!
  2. https://github.com/master255/VideoViewCache Simple Videoview with cache. Two threads for play and save data. Bad logic, but if you need then use this.

File tree view in Notepad++

open notepad++, then drag and drop the folder you want to open as tree view.

OR

File ->open folder as workspace , select the file you want.

Stupid error: Failed to load resource: net::ERR_CACHE_MISS

Google declares that this is not a failure, but some "misleading error reports". This bug will be fixed in version 40 of chrome.

You can read this:

Chromium forum
Chromium forum
Patch

Intellij Cannot resolve symbol on import

Nothing I tried above worked for me (not that I tried every suggestion). What finally did the trick was to rename the class -- I just added a 2 to the class name and filename. Then I resolved all the references manually. (Since they weren't recognized, the refactoring did not change the references automatically.)

Once the "2-version" was happily resolved everywhere, I was then able to refactor and remove the 2 from the class and file, and everything was then as it should be.

Postgres integer arrays as parameters?

Full Coding Structure

postgresql function

CREATE OR REPLACE FUNCTION admin.usp_itemdisplayid_byitemhead_select(
    item_head_list int[])
    RETURNS TABLE(item_display_id integer) 
    LANGUAGE 'sql'

    COST 100
    VOLATILE 
    ROWS 1000
    
AS $BODY$ 
        SELECT vii.item_display_id from admin.view_item_information as vii
where vii.item_head_id = ANY(item_head_list);
    $BODY$;

Model

public class CampaignCreator
    {
        public int item_display_id { get; set; }
        public List<int> pitem_head_id { get; set; }
    }

.NET CORE function

DynamicParameters _parameter = new DynamicParameters();
                _parameter.Add("@item_head_list",obj.pitem_head_id);
                
                string sql = "select * from admin.usp_itemdisplayid_byitemhead_select(@item_head_list)";
                response.data = await _connection.QueryAsync<CampaignCreator>(sql, _parameter);

Multiple inputs with same name through POST in php

For anyone else finding this - its worth noting that you can set the key value in the input name. Thanks to the answer in POSTing Form Fields with same Name Attribute you also can interplay strings or integers without quoting.

The answers assume that you don't mind the key value coming back for PHP however you can set name=[yourval] (string or int) which then allows you to refer to an existing record.

What's the difference between the Window.Loaded and Window.ContentRendered events

If you're using data binding, then you need to use the ContentRendered event.

For the code below, the Header is NULL when the Loaded event is raised. However, Header gets its value when the ContentRendered event is raised.

<MenuItem Header="{Binding NewGame_Name}" Command="{Binding NewGameCommand}" />

How to use XPath preceding-sibling correctly

I also like to build locators from up to bottom like:

//div[contains(@class,'btn-group')][./button[contains(.,'Arcade Reader')]]/button[@name='settings']

It's pretty simple, as we just search btn-group with button[contains(.,'Arcade Reader')] and get it's button[@name='settings']

That's just another option to build xPath locators

What is the profit of searching wrapper element: you can return it by method (example in java) and just build selenium constructions like:

getGroupByName("Arcade Reader").find("button[name='settings']");
getGroupByName("Arcade Reader").find("button[name='delete']");

or even simplify more

getGroupButton("Arcade Reader", "delete").click();

jQuery - keydown / keypress /keyup ENTERKEY detection?

JavaScript/jQuery

$("#entersomething").keyup(function(e){ 
    var code = e.key; // recommended to use e.key, it's normalized across devices and languages
    if(code==="Enter") e.preventDefault();
    if(code===" " || code==="Enter" || code===","|| code===";"){
        $("#displaysomething").html($(this).val());
    } // missing closing if brace
});

HTML

<input id="entersomething" type="text" /> <!-- put a type attribute in -->
<div id="displaysomething"></div>

Better way to call javascript function in a tag

I’m tempted to say that both are bad practices.

The use of onclick or javascript: should be dismissed in favor of listening to events from outside scripts, allowing for a better separation between markup and logic and thus leading to less repeated code.

Note also that external scripts get cached by the browser.

Have a look at this answer.

Some good ways of implementing cross-browser event listeners here.

How to implement swipe gestures for mobile devices?

Shameless plug I know, but you might want to consider a jQuery plugin that I wrote:

https://github.com/benmajor/jQuery-Mobile-Events

It does not require jQuery Mobile, only jQuery.

c++ string array initialization

In C++11 and above, you can also initialize std::vector with an initializer list. For example:

using namespace std; // for example only

for (auto s : vector<string>{"one","two","three"} ) 
    cout << s << endl;

So, your example would become:

void foo(vector<string> strArray){
  // some code
}

vector<string> s {"hi", "there"}; // Works
foo(s); // Works

foo(vector<string> {"hi", "there"}); // also works

TypeError: 'list' object cannot be interpreted as an integer

range is expecting an integer argument, from which it will build a range of integers:

>>> range(10)
range(0, 10)
>>> list(range(10))
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>>

Moreover, giving it a list will raise a TypeError because range will not know how to handle it:

>>> range([1, 2, 3])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'list' object cannot be interpreted as an integer
>>>

If you want to access the items in myList, loop over the list directly:

for i in myList:
    ...

Demo:

>>> myList = [1, 2, 3]
>>> for i in myList:
...     print(i)
...
1
2
3
>>>

Making a Sass mixin with optional arguments

You can always assign null to your optional arguments. Here is a simple fix

@mixin box-shadow($top, $left, $blur, $color, $inset:null) { //assigning null to inset value makes it optional
    -webkit-box-shadow: $top $left $blur $color $inset;
    -moz-box-shadow: $top $left $blur $color $inset;
    box-shadow: $top $left $blur $color $inset;
}

How to get JSON from webpage into Python script

I'll take a guess that you actually want to get data from the URL:

jsonurl = urlopen(url)
text = json.loads(jsonurl.read()) # <-- read from it

Or, check out JSON decoder in the requests library.

import requests
r = requests.get('someurl')
print r.json() # if response type was set to JSON, then you'll automatically have a JSON response here...

How to check if a variable is set in Bash?

To check for non-null/non-zero string variable, i.e. if set, use

if [ -n "$1" ]

It's the opposite of -z. I find myself using -n more than -z.

You would use it like:

if [ -n "$1" ]; then
  echo "You supplied the first parameter!"
else
  echo "First parameter not supplied."
fi

PHP GuzzleHttp. How to make a post request with params?

Try this

$client = new \GuzzleHttp\Client();
$client->post(
    'http://www.example.com/user/create',
    array(
        'form_params' => array(
            'email' => '[email protected]',
            'name' => 'Test user',
            'password' => 'testpassword'
        )
    )
);

How to redirect a url in NGINX

First make sure you have installed Nginx with the HTTP rewrite module. To install this we need to have pcre-library

How to install pcre library

If the above mentioned are done or if you already have them, then just add the below code in your nginx server block

  if ($host !~* ^www\.) {
    rewrite ^(.*)$ http://www.$host$1 permanent;
  }

To remove www from every request you can use

  if ($host = 'www.your_domain.com' ) {
   rewrite  ^/(.*)$  http://your_domain.com/$1  permanent;
  }

so your server block will look like

  server {
            listen       80;
            server_name  test.com;
            if ($host !~* ^www\.) {
                    rewrite ^(.*)$ http://www.$host$1 permanent;
            }
            client_max_body_size   10M;
            client_body_buffer_size   128k;

            root       /home/test/test/public;
            passenger_enabled on;
            rails_env production;

            error_page   500 502 503 504  /50x.html;
            location = /50x.html {
                    root   html;
            }
    }

Comprehensive beginner's virtualenv tutorial?

For setting up virtualenv on a clean Ubuntu installation, I found this zookeeper tutorial to be the best - you can ignore the parts about zookeper itself. The virtualenvwrapper documentation offers similar content, but it's a bit scarce on telling you what exactly to put into your .bashrc file.

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.

Automated testing for REST Api

One of the problems of doing automated testing for APIs is that many of the tools require you to have the API server up and running before you run your test suite. It can be a real advantage to have a unit testing framework that is capable of running and querying the APIs in a fully automated test environment.

An option that's good for APIs implemented with Node.JS / Express is to use mocha for automated testing. In addition to unit tests, its easy to write functional tests against the APIs, separated into different test suites. You can start up the API server automatically in the local test environment and set up a local test database. Using make, npm, and a build server, you can create a "make test" target and an incremental build that will run the entire test suite every time a piece of code is submitted to your repository. For the truly fastidious developer, it will even generate a nice HTML code-coverage report showing you which parts of your code base are covered by tests or not. If this sounds interesting, here's a blog post that provides all the technical details.

If you're not using node, then whatever the defacto unit testing framework for the language is (jUnit, cucumber/capybara, etc) - look at its support for spinning up servers in the local test environment and running the HTTP queries. If it's a large project, the effort to get automated API testing and continual integration working will pay off pretty quickly.

Hope that helps.

Vertical rulers in Visual Studio Code

Combining the answers of kiamlaluno and Mark, along with formatOnSave to autointent code for Python:

{
    "editor.formatOnSave": true,
    "editor.autoIndent": "advanced",
    "editor.detectIndentation": true,
    "files.insertFinalNewline": true,
    "files.trimTrailingWhitespace": true,
    "editor.formatOnPaste": true,
    "editor.multiCursorModifier": "ctrlCmd",
    "editor.snippetSuggestions": "top",
    "editor.rulers": [
        {
            "column": 79,
            "color": "#424142"
        },
        100, // <- a ruler in the default color or as customized at column 0
        {
            "column": 120,
            "color": "#ff0000"
        },
    ],

}

Deleting array elements in JavaScript - delete vs splice

function remove_array_value(array, value) {
    var index = array.indexOf(value);
    if (index >= 0) {
        array.splice(index, 1);
        reindex_array(array);
    }
}
function reindex_array(array) {
   var result = [];
    for (var key in array) {
        result.push(array[key]);
    }
    return result;
}

example:

var example_arr = ['apple', 'banana', 'lemon'];   // length = 3
remove_array_value(example_arr, 'banana');

banana is deleted and array length = 2

conditional Updating a list using LINQ

If you really want to use linq, you can do something like this

li= (from tl in li
    select new Myclass
    {
        name = tl.name,
        age = (tl.name == "di" ? 10 : (tl.name == "marks" ? 20 : 30))

    }).ToList();

or

li = li.Select(ex => new MyClass { name = ex.name, age = (ex.name == "di" ? 10 : (ex.name == "marks" ? 20 : 30)) }).ToList();

This assumes that there are only 3 types of name. I would externalize that part into a function to make it more manageable.