Programs & Examples On #Client side

The term "client-side" refers to that portion of a web application which runs in the user's browser. Client-side code is most commonly written in Javascript, HTML and CSS. The counterpart of "client-side" is "server-side", i.e., the part of a web application running at the web server.

Getting the text from a drop-down box

    var ele = document.getElementById('newSkill')
    ele.onchange = function(){
            var length = ele.children.length
            for(var i=0; i<length;i++){
                if(ele.children[i].selected){alert(ele.children[i].text)};              
            }
    }   

Sending emails with Javascript

You can use this free service: https://www.smtpjs.com

  1. Include the script:

<script src="https://smtpjs.com/v2/smtp.js"></script>

  1. Send an email using:
Email.send(
  "[email protected]",
  "[email protected]",
  "This is a subject",
  "this is the body",
  "smtp.yourisp.com",
  "username",
  "password"
);

Pass request headers in a jQuery AJAX GET call

Use beforeSend:

$.ajax({
         url: "http://localhost/PlatformPortal/Buyers/Account/SignIn",
         data: { signature: authHeader },
         type: "GET",
         beforeSend: function(xhr){xhr.setRequestHeader('X-Test-Header', 'test-value');},
         success: function() { alert('Success!' + authHeader); }
      });

http://api.jquery.com/jQuery.ajax/

http://www.w3.org/TR/XMLHttpRequest/#the-setrequestheader-method

Print directly from browser without print popup window

this.print(false);

I tried this in Chrome, Firefox and IE. It works only in Firefox and IE, it uses the default printer (with default print settings) and only works when I render a PDF (I use Foxit Reader with Safe Reading Mode disabled). Chrome shows the print dialog, also the other browsers when I render an HTML page.

Removing elements with Array.map in JavaScript

Array Filter method

_x000D_
_x000D_
var arr = [1, 2, 3]_x000D_
_x000D_
// ES5 syntax_x000D_
arr = arr.filter(function(item){ return item != 3 })_x000D_
_x000D_
// ES2015 syntax_x000D_
arr = arr.filter(item => item != 3)_x000D_
_x000D_
console.log( arr )
_x000D_
_x000D_
_x000D_

Best practice for localization and globalization of strings and labels

jQuery.i18n is a lightweight jQuery plugin for enabling internationalization in your web pages. It allows you to package custom resource strings in ‘.properties’ files, just like in Java Resource Bundles. It loads and parses resource bundles (.properties) based on provided language or language reported by browser.

to know more about this take a look at the How to internationalize your pages using JQuery?

How can you use php in a javascript function

You can't run PHP code with Javascript. When the user recieves the page, the server will have evaluated and run all PHP code, and taken it out. So for example, this will work:

alert( <?php echo "\"Hello\""; ?> );

Because server will have evaluated it to this:

alert("Hello");

However, you can't perform any operations in PHP with it.

This:

function Inc()
{
<?php
$num = 2;
echo $num;
?>
}

Will simply have been evaluated to this:

function Inc()
{
    2
}

If you wan't to call a PHP script, you'll have to call a different page which returns a value from a set of parameters.

This, for example, will work:

script.php

$num = $_POST["num"];
echo $num * 2;

Javascript(jQuery) (on another page):

$.post('script.php', { num: 5 }, function(result) { 
   alert(result); 
});

This should alert 10.

Good luck!

Edit: Just incrementing a number on the page can be done easily in jQuery like this: http://jsfiddle.net/puVPc/

Getting query parameters from react-router hash fragment

"react-router-dom": "^5.0.0",

you do not need to add any additional module, just in your component that has a url address like this:

http://localhost:3000/#/?authority'

you can try the following simple code:

    const search =this.props.location.search;
    const params = new URLSearchParams(search);
    const authority = params.get('authority'); //

How to export JavaScript array info to csv (on client side)?

The following is a native js solution.

_x000D_
_x000D_
function export2csv() {_x000D_
  let data = "";_x000D_
  const tableData = [];_x000D_
  const rows = [_x000D_
    ['111', '222', '333'],_x000D_
    ['aaa', 'bbb', 'ccc'],_x000D_
    ['AAA', 'BBB', 'CCC']_x000D_
  ];_x000D_
  for (const row of rows) {_x000D_
    const rowData = [];_x000D_
    for (const column of row) {_x000D_
      rowData.push(column);_x000D_
    }_x000D_
    tableData.push(rowData.join(","));_x000D_
  }_x000D_
  data += tableData.join("\n");_x000D_
  const a = document.createElement("a");_x000D_
  a.href = URL.createObjectURL(new Blob([data], { type: "text/csv" }));_x000D_
  a.setAttribute("download", "data.csv");_x000D_
  document.body.appendChild(a);_x000D_
  a.click();_x000D_
  document.body.removeChild(a);_x000D_
}
_x000D_
<button onclick="export2csv()">Export array to csv file</button>
_x000D_
_x000D_
_x000D_

Single Page Application: advantages and disadvantages

For such companies as google, amazon etc, whose servers are running at max capacity in 24/7-mode, reducing traffic means real money - less hardware, less energy, less maintenance. Shifting CPU-usage from server to client pays off, and SPAs shine. The advantages overweight disadvantages by far. So, SPA or not SPA depends much on the use case.

Just for mentioning another, probably not so obvious (for Web-developers) use case for SPAs: I'm currently looking for a way to implement GUIs in embedded systems and browser-based architecture seems appealing to me. Traditionally there were not many possibilities for UIs in embedded systems - Java, Qt, wx, etc or propriety commercial frameworks. Some years ago Adobe tried to enter the market with flash but seems to be not so successful.

Nowadays, as "embedded systems" are as powerful as mainframes some years ago, a browser-based UI connected to the control unit via REST is a possible solution. The advantage is, the huge palette of tools for UI for no cost. (e.g. Qt require 20-30$ per sold unit on royalty fees plus 3000-4000$ per developer)

For such architecture SPA offers many advantages - e.g. more familiar development-approach for desktop-app developers, reduced server access (often in car-industry the UI and system muddles are separate hardware, where the system-part has an RT OS).

As the only client is the built-in browser, the mentioned disadvantages like JS-availability, server-side logging, security don't count any more.

Image resizing client-side with JavaScript before upload to the server

Perhaps with the canvas tag (though it's not portable). There's a blog about how to rotate an image with canvas here, I suppose if you can rotate it, you can resize it. Maybe it can be a starting point.

See this library also.

How to create a file in memory for user to download, but not through server?

If the file contains text data, a technique I use is to put the text into a textarea element and have the user select it (click in textarea then ctrl-A) then copy followed by a paste to a text editor.

memcpy() vs memmove()

I'm not entirely surprised that your example exhibits no strange behaviour. Try copying str1 to str1+2 instead and see what happens then. (May not actually make a difference, depends on compiler/libraries.)

In general, memcpy is implemented in a simple (but fast) manner. Simplistically, it just loops over the data (in order), copying from one location to the other. This can result in the source being overwritten while it's being read.

Memmove does more work to ensure it handles the overlap correctly.

EDIT:

(Unfortunately, I can't find decent examples, but these will do). Contrast the memcpy and memmove implementations shown here. memcpy just loops, while memmove performs a test to determine which direction to loop in to avoid corrupting the data. These implementations are rather simple. Most high-performance implementations are more complicated (involving copying word-size blocks at a time rather than bytes).

Connect to Active Directory via LDAP

DC is your domain. If you want to connect to the domain example.com than your dc's are: DC=example,DC=com

You actually don't need any hostname or ip address of your domain controller (There could be plenty of them).

Just imagine that you're connecting to the domain itself. So for connecting to the domain example.com you can simply write

DirectoryEntry directoryEntry = new DirectoryEntry("LDAP://example.com");

And you're done.

You can also specify a user and a password used to connect:

DirectoryEntry directoryEntry = new DirectoryEntry("LDAP://example.com", "username", "password");

Also be sure to always write LDAP in upper case. I had some trouble and strange exceptions until I read somewhere that I should try to write it in upper case and that solved my problems.

The directoryEntry.Path Property allows you to dive deeper into your domain. So if you want to search a user in a specific OU (Organizational Unit) you can set it there.

DirectoryEntry directoryEntry = new DirectoryEntry("LDAP://example.com");
directoryEntry.Path = "LDAP://OU=Specific Users,OU=All Users,OU=Users,DC=example,DC=com";

This would match the following AD hierarchy:

  • com
    • example
      • Users
        • All Users
          • Specific Users

Simply write the hierarchy from deepest to highest.

Now you can do plenty of things

For example search a user by account name and get the user's surname:

DirectoryEntry directoryEntry = new DirectoryEntry("LDAP://example.com");
DirectorySearcher searcher = new DirectorySearcher(directoryEntry) {
    PageSize = int.MaxValue,
    Filter = "(&(objectCategory=person)(objectClass=user)(sAMAccountName=AnAccountName))"
};

searcher.PropertiesToLoad.Add("sn");

var result = searcher.FindOne();

if (result == null) {
    return; // Or whatever you need to do in this case
}

string surname;

if (result.Properties.Contains("sn")) {
    surname = result.Properties["sn"][0].ToString();
}

How do you validate a URL with a regular expression in Python?

Nowadays, in 90% of case if you working with URL in Python you probably use python-requests. Hence the question here - why not reuse URL validation from requests?

from requests.models import PreparedRequest
import requests.exceptions


def check_url(url):
    prepared_request = PreparedRequest()
    try:
        prepared_request.prepare_url(url, None)
        return prepared_request.url
    except requests.exceptions.MissingSchema, e:
        raise SomeException

Features:

  • Don't reinvent the wheel
  • DRY
  • Work offline
  • Minimal resource

How to update nested state properties in React

you can do this with object spreading code :

 this.setState((state)=>({ someProperty:{...state.someProperty,flag:false}})

this will work for more nested property

Loop through a Map with JSTL

You can loop through a hash map like this

<%
ArrayList list = new ArrayList();
TreeMap itemList=new TreeMap();
itemList.put("test", "test");
list.add(itemList);
pageContext.setAttribute("itemList", list);                            
%>

  <c:forEach items="${itemList}" var="itemrow">
   <input  type="text"  value="<c:out value='${itemrow.test}'/>"/>
  </c:forEach>               

For more JSTL functionality look here

Failed to find Build Tools revision 23.0.1

Two solutions: You have to instal the required buildToolVersion or set it as described above.
Notice that if you are trying to set the buildToolsVersion "23.0.3" using Android Studio 3.0 or more it won't work until you remove all builversion you have keeping just one last version you use. I read this somewhere else and this works for me. Hope this helps.

How to convert array to SimpleXML

My answer, cobbling together others' answers. This should correct for the failure to compensate for numeric keys:

function array_to_xml($array, $root, $element) {
    $xml = new SimpleXMLElement("<{$root}/>");
    foreach ($array as $value) {
        $elem = $xml->addChild($element);
        xml_recurse_child($elem, $value);
    }
    return $xml;
}

function xml_recurse_child(&$node, $child) {
    foreach ($child as $key=>$value) {
        if(is_array($value)) {
            foreach ($value as $k => $v) {
                if(is_numeric($k)){
                    xml_recurse_child($node, array($key => $v));
                }
                else {
                    $subnode = $node->addChild($key);
                    xml_recurse_child($subnode, $value);
                }
            }
        }
        else {
            $node->addChild($key, $value);
        }
    }   
}

The array_to_xml() function presumes that the array is made up of numeric keys first. If your array had an initial element, you would drop the foreach() and $elem statements from the array_to_xml() function and just pass $xml instead.

Process list on Linux via Python

import os
lst = os.popen('sudo netstat -tulpn').read()
lst = lst.split('\n')
for i in range(2,len(lst)):
    print(lst[i])

How can I write these variables into one line of code in C#?

Simple as:

DateTime.Now.ToString("MM.dd.yyyy");

link to MSDN on ALL formatting options for DateTime.ToString() method

http://msdn.microsoft.com/en-us/library/8kb3ddd4.aspx

The server response was: 5.7.0 Must issue a STARTTLS command first. i16sm1806350pag.18 - gsmtp

Step (1): smtp.EnableSsl = true;

if not enough:

Step (2): "Access for less secure apps" must be enabled for the Gmail account used by the NetworkCredential using google's settings page:

Convert base64 string to image

In the server, do something like this:

Suppose

String data = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAPAAAADwCAYAAAA+VemSAAAgAEl...=='

Then:

String base64Image = data.split(",")[1];
byte[] imageBytes = javax.xml.bind.DatatypeConverter.parseBase64Binary(base64Image);

Then you can do whatever you like with the bytes like:

BufferedImage img = ImageIO.read(new ByteArrayInputStream(imageBytes));

Converting file into Base64String and back again

For Java, consider using Apache Commons FileUtils:

/**
 * Convert a file to base64 string representation
 */
public String fileToBase64(File file) throws IOException {
    final byte[] bytes = FileUtils.readFileToByteArray(file);
    return Base64.getEncoder().encodeToString(bytes);
}

/**
 * Convert base64 string representation to a file
 */
public void base64ToFile(String base64String, String filePath) throws IOException {
    byte[] bytes = Base64.getDecoder().decode(base64String);
    FileUtils.writeByteArrayToFile(new File(filePath), bytes);
}

Counting in a FOR loop using Windows Batch script

Here is a batch file that generates all 10.x.x.x addresses

@echo off

SET /A X=0
SET /A Y=0
SET /A Z=0

:loop
SET /A X+=1
echo 10.%X%.%Y%.%Z%
IF "%X%" == "256" (
 GOTO end
 ) ELSE (
 GOTO loop2
 GOTO loop
 )


:loop2
SET /A Y+=1
echo 10.%X%.%Y%.%Z%
IF "%Y%" == "256" (
  SET /A Y=0
  GOTO loop
  ) ELSE (
   GOTO loop3
   GOTO loop2
 )


:loop3

SET /A Z+=1
echo 10.%X%.%Y%.%Z%
IF "%Z%" == "255" (
  SET /A Z=0
  GOTO loop2
 ) ELSE (
   GOTO loop3
 )

:end

How to get ip address of a server on Centos 7 in bash

You can use hostname command :

ipaddr=$(hostname -I)

-i, --ip-address: Display the IP address(es) of the host. Note that this works only if the host name can be resolved.

-I, --all-ip-addresses: Display all network addresses of the host. This option enumerates all configured addresses on all network interfaces. The loopback interface and IPv6 link-local addresses are omitted. Contrary to option -i, this option does not depend on name resolution. Do not make any assumptions about the order of the output.

Is it possible to remove the hand cursor that appears when hovering over a link? (or keep it set as the normal pointer)

<button>
  <a href="https://accounts.google.com/ServiceLogin?continue=http%3A%2F%2Fmail.google.com%2Fmail%2F%3Fpc%3Den-ha-apac-in-bk-refresh14&service=mail&dsh=-3966619600017513905"
     style="cursor:default">sign in</a>
</button>

WPF - add static items to a combo box

Here is the code from MSDN and the link - Article Link, which you should check out for more detail.

<ComboBox Text="Is not open">
    <ComboBoxItem Name="cbi1">Item1</ComboBoxItem>
    <ComboBoxItem Name="cbi2">Item2</ComboBoxItem>
    <ComboBoxItem Name="cbi3">Item3</ComboBoxItem>
</ComboBox>

How to do the Recursive SELECT query in MySQL?

If you want to be able to have a SELECT without problems of the parent id having to be lower than child id, a function could be used. It supports also multiple children (as a tree should do) and the tree can have multiple heads. It also ensure to break if a loop exists in the data.

I wanted to use dynamic SQL to be able to pass the table/columns names, but functions in MySQL don't support this.

DELIMITER $$

CREATE FUNCTION `isSubElement`(pParentId INT, pId INT) RETURNS int(11)
DETERMINISTIC    
READS SQL DATA
BEGIN
DECLARE isChild,curId,curParent,lastParent int;
SET isChild = 0;
SET curId = pId;
SET curParent = -1;
SET lastParent = -2;

WHILE lastParent <> curParent AND curParent <> 0 AND curId <> -1 AND curParent <> pId AND isChild = 0 DO
    SET lastParent = curParent;
    SELECT ParentId from `test` where id=curId limit 1 into curParent;

    IF curParent = pParentId THEN
        SET isChild = 1;
    END IF;
    SET curId = curParent;
END WHILE;

RETURN isChild;
END$$

Here, the table test has to be modified to the real table name and the columns (ParentId,Id) may have to be adjusted for your real names.

Usage :

SET @wantedSubTreeId = 3;
SELECT * FROM test WHERE isSubElement(@wantedSubTreeId,id) = 1 OR ID = @wantedSubTreeId;

Result :

3   7   k
5   3   d
9   3   f
1   5   a

SQL for test creation :

CREATE TABLE IF NOT EXISTS `test` (
  `Id` int(11) NOT NULL,
  `ParentId` int(11) DEFAULT NULL,
  `Name` varchar(300) NOT NULL,
  PRIMARY KEY (`Id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1;

insert into test (id, parentid, name) values(3,7,'k');
insert into test (id, parentid, name) values(5,3,'d');
insert into test (id, parentid, name) values(9,3,'f');
insert into test (id, parentid, name) values(1,5,'a');
insert into test (id, parentid, name) values(6,2,'o');
insert into test (id, parentid, name) values(2,8,'c');

EDIT : Here is a fiddle to test it yourself. It forced me to change the delimiter using the predefined one, but it works.

Cannot deserialize the current JSON array (e.g. [1,2,3]) into type

HttpClient webClient = new HttpClient();
Uri uri = new Uri("your url");
HttpResponseMessage response = await webClient.GetAsync(uri)
var jsonString = await response.Content.ReadAsStringAsync();
var objData = JsonConvert.DeserializeObject<List<CategoryModel>>(jsonString);

How to get value by class name in JavaScript or jquery?

If you get the the text inside the element use

Text()

$(".element-classname").text();

In your code:

$('.HOEnZb').text();

if you want get all the data including html Tags use:

html()

 $(".element-classname").html();

In your code:

$('.HOEnZb').html();

Hope it helps:)

Can two applications listen to the same port?

In principle, no.

It's not written in stone; but it's the way all APIs are written: the app opens a port, gets a handle to it, and the OS notifies it (via that handle) when a client connection (or a packet in UDP case) arrives.

If the OS allowed two apps to open the same port, how would it know which one to notify?

But... there are ways around it:

  1. As Jed noted, you could write a 'master' process, which would be the only one that really listens on the port and notifies others, using any logic it wants to separate client requests.
    • On Linux and BSD (at least) you can set up 'remapping' rules that redirect packets from the 'visible' port to different ones (where the apps are listening), according to any network related criteria (maybe network of origin, or some simple forms of load balancing).

Display HTML form values in same page after submit using Ajax

display html form values in same page after clicking on submit button using JS & html codes. After opening it up again it should give that comments in that page.

jasmine: Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL

You can use karma-jasmine plugin to set the default time out interval globally.

Add this config in karma.conf.js

module.exports = function(config) {
  config.set({
    client: {
      jasmine: {
        timeoutInterval: 10000
      }
    }
  })
}

Form Submit Execute JavaScript Best Practice?

Attach an event handler to the submit event of the form. Make sure it cancels the default action.

Quirks Mode has a guide to event handlers, but you would probably be better off using a library to simplify the code and iron out the differences between browsers. All the major ones (such as YUI and jQuery) include event handling features, and there is a large collection of tiny event libraries.

Here is how you would do it in YUI 3:

<script src="http://yui.yahooapis.com/3.4.1/build/yui/yui-min.js"></script>
<script>
    YUI().use('event', function (Y) {
        Y.one('form').on('submit', function (e) {
            // Whatever else you want to do goes here
            e.preventDefault();
        });
    });
</script>

Make sure that the server will pick up the slack if the JavaScript fails for any reason.

How can I make Flexbox children 100% height of their parent?

An idea would be that display:flex; with flex-direction: row; is filling the container div with .flex-1 and .flex-2, but that does not mean that .flex-2 has a default height:100%;, even if it is extended to full height.

And to have a child element (.flex-2-child) with height:100%;, you'll need to set the parent to height:100%; or use display:flex; with flex-direction: row; on the .flex-2 div too.

From what I know, display:flex will not extend all your child elements height to 100%.

A small demo, removed the height from .flex-2-child and used display:flex; on .flex-2: http://jsfiddle.net/2ZDuE/3/

How to get certain commit from GitHub project

Try the following command sequence:

$ git fetch origin <copy/past commit sha1 here>
$ git checkout FETCH_HEAD
$ git push origin master

Better way to set distance between flexbox items

tl;dr

$gutter: 8px;

.container {
  display: flex;
  justify-content: space-between;

  .children {
    flex: 0 0 calc(33.3333% - $gutter);
  }
}

@Html.DisplayFor - DateFormat ("mm/dd/yyyy")

If you use DisplayFor, then you have to either define the format via the DisplayFormat attribute or use a custom display template. (A full list of preset DisplayFormatString's can be found here.)

[DisplayFormat(DataFormatString = "{0:d}")]
public DateTime? AuditDate { get; set; }

Or create the view Views\Shared\DisplayTemplates\DateTime.cshtml:

@model DateTime?
@if (Model.HasValue)
{
    @Model.Value.ToString("MM/dd/yyyy")
}

That will apply to all DateTimes, though, even ones where you're encoding the time as well. If you want it to apply only to date-only properties, then use Views\Shared\DisplayTemplates\Date.cshtml and the DataType attribute on your property:

[DataType(DataType.Date)]
public DateTime? AuditDate { get; set; }

The final option is to not use DisplayFor and instead render the property directly:

@if (Model.AuditDate.HasValue)
{
    @Model.AuditDate.Value.ToString("MM/dd/yyyy")
}

How do I read a response from Python Requests?

If you push for example image to some API and want the result address(response) back you could do:

import requests
url = 'https://uguu.se/api.php?d=upload-tool'
data = {"name": filename}
files = {'file': open(full_file_path, 'rb')}
response = requests.post(url, data=data, files=files)
current_url = response.text
print(response.text)

How to convert Hexadecimal #FFFFFF to System.Drawing.Color

string hex = "#FFFFFF";
Color _color = System.Drawing.ColorTranslator.FromHtml(hex);

Note: the hash is important!

Java - How Can I Write My ArrayList to a file, and Read (load) that file to the original ArrayList?

In Java 8 you can use Files.write() method with two arguments: Path and List<String>, something like this:

List<String> clubNames = clubs.stream()
    .map(Club::getName)
    .collect(Collectors.toList())

try {
    Files.write(Paths.get(fileName), clubNames);
} catch (IOException e) {
    log.error("Unable to write out names", e);
}

javascript set cookie with expire time

I'd like to second Polin's answer and just add one thing in case you are still stuck. This code certainly does work to set a specific cookie expiration time. One issue you may be having is that if you are using Chrome and accessing your page via "http://localhost..." or "file://", Chrome will not store cookies. The easy fix for this is to use a simple http server (like node's http-server if you haven't already) and navigate to your page explicitly as "http://127.0.0.1" in which case Chrome WILL store cookies for local development. This had me hung up for a bit as, if you don't do this, your expires key will simply have the value of "session" when you investigate it in the console or in Dev Tools.

How to count the number of columns in a table using SQL?

Maybe something like this:

SELECT count(*) FROM user_tab_columns WHERE table_name = 'FOO'

this will count number of columns in a the table FOO

You can also just

select count(*) from all_tab_columns where owner='BAR' and table_name='FOO';

where the owner is schema and note that Table Names are upper case

Node.js throws "btoa is not defined" error

Here's a concise universal solution for base64 encoding:

const nodeBtoa = (b) => Buffer.from(b).toString('base64');
export const base64encode = typeof btoa !== 'undefined' ? btoa : nodeBtoa;

An error when I add a variable to a string

You have empty $entry_database variable. As you see in error: ListEmail, Title FROM WHERE ID bewteen FROM and WHERE should be name of table. Proper syntax of SELECT:

SELECT columns FROM table [optional things as WHERE/ORDER/GROUP/JOIN etc]

which in your way should become:

SELECT ID, ListStID, ListEmail, Title FROM some_table_you_got WHERE ID = '4'

How do I write a Windows batch script to copy the newest file from a directory?

@echo off
set source="C:\test case"
set target="C:\Users\Alexander\Desktop\random folder"

FOR /F "delims=" %%I IN ('DIR %source%\*.* /A:-D /O:-D /B') DO COPY %source%\"%%I" %target% & echo %%I & GOTO :END
:END
TIMEOUT 4

My attempt to copy the newest file from a folder

just set your source and target folders and it should work

This one ignores folders, concern itself only with files

Recommed that you choose filetype in the DIR path changing *.* to *.zip for example

TIMEOUT wont work on winXP I think

How can I check if a string contains ANY letters from the alphabet?

I tested each of the above methods for finding if any alphabets are contained in a given string and found out average processing time per string on a standard computer.

~250 ns for

import re

~3 µs for

re.search('[a-zA-Z]', string)

~6 µs for

any(c.isalpha() for c in string)

~850 ns for

string.upper().isupper()


Opposite to as alleged, importing re takes negligible time, and searching with re takes just about half time as compared to iterating isalpha() even for a relatively small string.
Hence for larger strings and greater counts, re would be significantly more efficient.

But converting string to a case and checking case (i.e. any of upper().isupper() or lower().islower() ) wins here. In every loop it is significantly faster than re.search() and it doesn't even require any additional imports.

NSURLErrorDomain error codes description

I received the error Domain=NSURLErrorDomain Code=-1011 when using Parse, and providing the wrong clientKey. As soon as I corrected that, it began working.

Remove ALL white spaces from text

Regex for remove white space

\s+

_x000D_
_x000D_
var str = "Visit Microsoft!";
var res = str.replace(/\s+/g, "");
console.log(res);
_x000D_
_x000D_
_x000D_

or

[ ]+

_x000D_
_x000D_
var str = "Visit Microsoft!";
var res = str.replace(/[ ]+/g, "");
console.log(res);
_x000D_
_x000D_
_x000D_

Remove all white space at begin of string

^[ ]+

_x000D_
_x000D_
var str = "    Visit Microsoft!";
var res = str.replace(/^[ ]+/g, "");
console.log(res);
_x000D_
_x000D_
_x000D_

remove all white space at end of string

[ ]+$

_x000D_
_x000D_
var str = "Visit Microsoft!      ";
var res = str.replace(/[ ]+$/g, "");
console.log(res);
_x000D_
_x000D_
_x000D_

A div with auto resize when changing window width\height

Use vh attributes. It means viewport height and is a percentage. So height: 90vh would mean 90% of the viewport height. This works in most modern browsers.

Eg.

div {
  height: 90vh;
}

You can forego the rest of your silly 100% stuff on the body.

If you have a header you can also do some fun things like take it into account by using the calc function in CSS.

Eg.

div {
  height: calc(100vh - 50px);
}

This will give you 100% of the viewport height, minus 50px for your header.

Downloading images with node.js

I'd suggest using the request module. Downloading a file is as simple as the following code:

var fs = require('fs'),
    request = require('request');

var download = function(uri, filename, callback){
  request.head(uri, function(err, res, body){
    console.log('content-type:', res.headers['content-type']);
    console.log('content-length:', res.headers['content-length']);

    request(uri).pipe(fs.createWriteStream(filename)).on('close', callback);
  });
};

download('https://www.google.com/images/srpr/logo3w.png', 'google.png', function(){
  console.log('done');
});

Git error: "Host Key Verification Failed" when connecting to remote repository

As I answered previously in Cloning git repo causes error - Host key verification failed. fatal: The remote end hung up unexpectedly, add the GitHub to the list of authorized hosts:

ssh-keyscan -t rsa github.com >> ~/.ssh/known_hosts

How to import multiple csv files in a single load?

val df = spark.read.option("header", "true").csv("C:spark\\sample_data\\*.csv)

will consider files tmp, tmp1, tmp2, ....

github changes not staged for commit

Believe this occurs because you have a child repository "submodule" that has changes which have not been staged and committed.

Had a similar problem, where my IDE kept reporting uncommitted changes, and running the stage (git add .) and commit (git commit -m "message") commands had no effect. Thinking about this in hindsight, it's probably because the child repository had the changes that needed to be staged and committed, not the parent repository.

Steps that fixed the issue

  1. cd into the submodule (has a hidden folder named .git) and execute the commands to stage (git add .) and commit (git commit -m "Update child repo")
  2. cd .. back to the parent repo, and execute the commands to stage (git add .) and commit (git commit -m "Update parent repo")

Advice that wasn't helpful

  • sudo rm -Rf .git == DO NOT USE THIS COMMAND == it permanently deletes submodule repository history (the purpose of GIT)
  • git add -A === Added untracked files, but didn't fix issue

How to skip to next iteration in jQuery.each() util?

Javascript sort of has the idea of 'truthiness' and 'falsiness'. If a variable has a value then, generally 9as you will see) it has 'truthiness' - null, or no value tends to 'falsiness'. The snippets below might help:

var temp1; 
if ( temp1 )...  // false

var temp2 = true;
if ( temp2 )...  // true

var temp3 = "";
if ( temp3 ).... // false

var temp4 = "hello world";
if ( temp4 )...  // true

Hopefully that helps?

Also, its worth checking out these videos from Douglas Crockford

update: thanks @cphpython for spotting the broken links - I've updated to point at working versions now

The Javascript language

Javascript - The Good Parts

Change application's starting activity

Follow to below instructions:

1:) Open your AndroidManifest.xml file.

2:) Go to the activity code which you want to make your main activity like below.

such as i want to make SplashScreen as main activity

<activity
    android:name=".SplashScreen"
    android:screenOrientation="sensorPortrait"
    android:label="City Retails">
</activity>

3:) Now copy the below code in between activity tags same as:

<activity
    android:name=".SplashScreen"
    android:screenOrientation="sensorPortrait"
    android:label="City Retails">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

and also check that newly added lines are not attached with other activity tags.

Convert char * to LPWSTR

This version, using the Windows API function MultiByteToWideChar(), handles the memory allocation for arbitrarily long input strings.

int lenA = lstrlenA(input);
int lenW = ::MultiByteToWideChar(CP_ACP, 0, input, lenA, NULL, 0);
if (lenW>0)
{
    output = new wchar_t[lenW];
    ::MultiByteToWideChar(CP_ACP, 0, input, lenA, output, lenW);
} 

Docker: How to use bash with an Alpine based docker image?

RUN /bin/sh -c "apk add --no-cache bash"

worked for me.

How to put a component inside another component in Angular2?

I think in your Angular-2 version directives are not supported in Component decorator, hence you have to register directive same as other component in @NgModule and then import in component as below and also remove directives: [ChildComponent] from decorator.

import {myDirective} from './myDirective';

How to set selectedIndex of select element using display text?

Try this:

function SelectAnimal()
{
    var animals = document.getElementById('Animals');
    var animalsToFind = document.getElementById('AnimalToFind');
    // get the options length
    var len = animals.options.length;
    for(i = 0; i < len; i++)
    {
      // check the current option's text if it's the same with the input box
      if (animals.options[i].innerHTML == animalsToFind.value)
      {
         animals.selectedIndex = i;
         break;
      }     
    }
}

How do you test running time of VBA code?

Seconds with 2 decimal spaces:

Dim startTime As Single 'start timer
MsgBox ("run time: " & Format((Timer - startTime) / 1000000, "#,##0.00") & " seconds") 'end timer

seconds format

Milliseconds:

Dim startTime As Single 'start timer
MsgBox ("run time: " & Format((Timer - startTime), "#,##0.00") & " milliseconds") 'end timer

milliseconds format

Milliseconds with comma seperator:

Dim startTime As Single 'start timer
MsgBox ("run time: " & Format((Timer - startTime) * 1000, "#,##0.00") & " milliseconds") 'end timer

Milliseconds with comma seperator

Just leaving this here for anyone that was looking for a simple timer formatted with seconds to 2 decimal spaces like I was. These are short and sweet little timers I like to use. They only take up one line of code at the beginning of the sub or function and one line of code again at the end. These aren't meant to be crazy accurate, I generally don't care about anything less then 1/100th of a second personally, but the milliseconds timer will give you the most accurate run time of these 3. I've also read you can get the incorrect read out if it happens to run while crossing over midnight, a rare instance but just FYI.

Change value of input onchange?

You can't access your fieldname as a global variable. Use document.getElementById:

function updateInput(ish){
    document.getElementById("fieldname").value = ish;
}

and

onchange="updateInput(this.value)"

how to call a method in another Activity from Activity

The startActivityForResult pattern is much better suited for what you're trying to achieve : http://developer.android.com/reference/android/app/Activity.html#StartingActivities

Try below code

public class MainActivity extends Activity {  

    Button button1;  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
        textView1=(TextView)findViewById(R.id.textView1);  
        button1=(Button)findViewById(R.id.button1);  
        button1.setOnClickListener(new OnClickListener() {  
            @Override  
            public void onClick(View arg0) {  
                Intent intent=new Intent(MainActivity.this,SecondActivity.class);  
                startActivityForResult(intent, 2);// Activity is started with requestCode 2  
            }  
        });  
    }  
 // Call Back method  to get the Message form other Activity  
    @Override  
       protected void onActivityResult(int requestCode, int resultCode, Intent data)  
       {  
                 super.onActivityResult(requestCode, resultCode, data);  
                  // check if the request code is same as what is passed  here it is 2  
                   if(requestCode==2)  
                         {  
                          //do the things u wanted 
                         }  
     }  

} 

SecondActivity.class

public class SecondActivity extends Activity {  

    Button button1;  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_second);  

            button1=(Button)findViewById(R.id.button1);  
            button1.setOnClickListener(new OnClickListener() {  
                @Override  
                public void onClick(View arg0) {  
                    String message="hello ";  
                    Intent intent=new Intent();  
                    intent.putExtra("MESSAGE",message);  
                    setResult(2,intent);  
                    finish();//finishing activity  
                }  
            });  
    }  

}  

Let me know if it helped...

Android 6.0 Marshmallow. Cannot write to SD Card

I faced the same problem. There are two types of permissions in Android:

  • Dangerous (access to contacts, write to external storage...)
  • Normal

Normal permissions are automatically approved by Android while dangerous permissions need to be approved by Android users.

Here is the strategy to get dangerous permissions in Android 6.0

  1. Check if you have the permission granted
  2. If your app is already granted the permission, go ahead and perform normally.
  3. If your app doesn't have the permission yet, ask for user to approve
  4. Listen to user approval in onRequestPermissionsResult

Here is my case: I need to write to external storage.

First, I check if I have the permission:

...
private static final int REQUEST_WRITE_STORAGE = 112;
...
boolean hasPermission = (ContextCompat.checkSelfPermission(activity,
            Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED);
if (!hasPermission) {
    ActivityCompat.requestPermissions(parentActivity,
                new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                REQUEST_WRITE_STORAGE);
}

Then check the user's approval:

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    switch (requestCode)
    {
        case REQUEST_WRITE_STORAGE: {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
            {
                //reload my activity with permission granted or use the features what required the permission
            } else
            {
                Toast.makeText(parentActivity, "The app was not allowed to write to your storage. Hence, it cannot function properly. Please consider granting it this permission", Toast.LENGTH_LONG).show();
            }
        }
    }

}

You can read more about the new permission model here: https://developer.android.com/training/permissions/requesting.html

href around input type submit

<a href="1.html"><input type="text" class="button_active" value="1"></a>
<a href="2.html"><input type="text" class="button" value="2"></a>
<a href="3.html"><input type="text" class="button" value="3"></a>

Try that. Unless you truly need to stick with the type as submit, then what I provided should work. If you are going to stick with submit, then everything mentioned above is correct, it makes no sense.

How to capitalize the first letter of a String in Java?

Using commons.lang.StringUtils the best answer is:

public static String capitalize(String str) {  
    int strLen;  
    return str != null && (strLen = str.length()) != 0 ? (new StringBuffer(strLen)).append(Character.toTitleCase(str.charAt(0))).append(str.substring(1)).toString() : str;  
}

I find it brilliant since it wraps the string with a StringBuffer. You can manipulate the StringBuffer as you wish and though using the same instance.

Rotating a view in Android

That's simple, in Java

your_component.setRotation(15);

or

your_component.setRotation(295.18f);

in XML

<Button android:rotation="15" />

PyLint "Unable to import" error - how to set PYTHONPATH?

I had the same problem and since i could not find a answer I hope this can help anyone with a similar problem.

I use flymake with epylint. Basically what i did was add a dired-mode-hook that check if the dired directory is a python package directory. If it is I add it to the PYTHONPATH. In my case I consider a directory to be a python package if it contains a file named "setup.py".

;;;;;;;;;;;;;;;;;
;; PYTHON PATH ;;
;;;;;;;;;;;;;;;;;

(defun python-expand-path ()
  "Append a directory to the PYTHONPATH."
  (interactive
   (let ((string (read-directory-name 
          "Python package directory: " 
          nil 
          'my-history)))
     (setenv "PYTHONPATH" (concat (expand-file-name string)
                  (getenv ":PYTHONPATH"))))))

(defun pythonpath-dired-mode-hook ()
  (let ((setup_py (concat default-directory "setup.py"))
    (directory (expand-file-name default-directory)))
    ;;   (if (file-exists-p setup_py)
    (if (is-python-package-directory directory)
    (let ((pythonpath (concat (getenv "PYTHONPATH") ":" 
                  (expand-file-name directory))))
      (setenv "PYTHONPATH" pythonpath)
      (message (concat "PYTHONPATH=" (getenv "PYTHONPATH")))))))

(defun is-python-package-directory (directory)
  (let ((setup_py (concat directory "setup.py")))
    (file-exists-p setup_py)))

(add-hook 'dired-mode-hook 'pythonpath-dired-mode-hook)

Hope this helps.

How to customize <input type="file">?

You can’t modify much about the input[type=file] control itself.

Since clicking a label element correctly paired with an input will activate/focus it, we can use a label to trigger the OS browse dialog.

Here is how you can do it…

_x000D_
_x000D_
label {_x000D_
   cursor: pointer;_x000D_
   /* Style as you please, it will become the visible UI component. */_x000D_
}_x000D_
_x000D_
#upload-photo {_x000D_
   opacity: 0;_x000D_
   position: absolute;_x000D_
   z-index: -1;_x000D_
}
_x000D_
<label for="upload-photo">Browse...</label>_x000D_
<input type="file" name="photo" id="upload-photo" />
_x000D_
_x000D_
_x000D_

The CSS for the form control will make it appear invisible and not take up space in the document layout, but will still exist so it can be activated via the label.

If you want to display the user’s chosen path after selection, you can listen for the change event with JavaScript and then read the path that the browser makes available to you (for security reasons it can lie to you about the exact path). A way to make it pretty for the end user is to simply use the base name of the path that is returned (so the user simply sees the chosen filename).

There is a great guide by Tympanus for styling this.

How to sum digits of an integer in java?

without mapping ? the quicker lambda solution

Integer.toString( num ).chars().boxed().collect( Collectors.summingInt( (c) -> c - '0' ) );

…or same with the slower % operator

Integer.toString( num ).chars().boxed().collect( Collectors.summingInt( (c) -> c % '0' ) );


…or Unicode compliant

Integer.toString( num ).codePoints().boxed().collect( Collectors.summingInt( Character::getNumericValue ) );

vb.net get file names in directory?

You will need to use the IO.Directory.GetFiles function.

Dim files() As String = IO.Directory.GetFiles("c:\")

For Each file As String In files
  ' Do work, example
  Dim text As String = IO.File.ReadAllText(file)
Next

Best way to compare two complex objects

Based off a few answers already given here I decided to mostly back JoelFan's answer. I love extension methods and these have been working great for me when none of the other solutions would using them to compare my complex classes.

Extension Methods

using System.IO;
using System.Xml.Serialization;

static class ObjectHelpers
{
    public static string SerializeObject<T>(this T toSerialize)
    {
        XmlSerializer xmlSerializer = new XmlSerializer(toSerialize.GetType());

        using (StringWriter textWriter = new StringWriter())
        {
            xmlSerializer.Serialize(textWriter, toSerialize);
            return textWriter.ToString();
        }
    }

    public static bool EqualTo(this object obj, object toCompare)
    {
        if (obj.SerializeObject() == toCompare.SerializeObject())
            return true;
        else
            return false;
    }

    public static bool IsBlank<T>(this T obj) where T: new()
    {
        T blank = new T();
        T newObj = ((T)obj);

        if (newObj.SerializeObject() == blank.SerializeObject())
            return true;
        else
            return false;
    }

}

Usage Examples

if (record.IsBlank())
    throw new Exception("Record found is blank.");

if (record.EqualTo(new record()))
    throw new Exception("Record found is blank.");

Port 80 is being used by SYSTEM (PID 4), what is that?

Identify the process programmatically

All the answers to date have required the user to do something interactive. This is how you find the PID when netstat shows you PID 4, without needing to open some GUI or handle a dialogue about depending services.

$Uri = "http://127.0.0.1:8989"    # for example


# Shows processes that have registered URLs with HTTP.sys
$QueueText = netsh http show servicestate view=requestq verbose=yes | Out-String

# Break into text chunks; discard the header
$Queues    = $QueueText -split '(?<=\n)(?=Request queue name)' | Select-Object -Skip 1

# Find the chunk for the request queue listening on your URI
$Queue     = @($Queues) -match [regex]::Escape($Uri -replace '/$')


if ($Queue.Count -eq 1)
{
    # Will be null if could not pick out exactly one PID
    $ProcessId = [string]$Queue -replace '(?s).*Process IDs:\s+' -replace '(?s)\s.*' -as [int]

    if ($ProcessId)
    {
        Write-Verbose "Identified process $ProcessId as the HTTP listener. Killing..."
        Stop-Process -Id $ProcessId -Confirm
    }
}

That really busted my chops. I hate HttpListener and wish I'd just used Pode.

java.lang.IllegalStateException: Only fullscreen opaque activities can request orientation

Just remove this line android:screenOrientation="portrait" of activity in Manifiest.xml

That activity will get orientation from it's previous activity so no need to apply orientation which has <item name="android:windowIsTranslucent">true</item>.

How to find which version of Oracle is installed on a Linux server (In terminal)

Login as sys user in sql*plus. Then do this query:

select * from v$version; 

or

select * from product_component_version;

JBoss default password

I just had to uncomment the line in jboss-eap-5.0\jboss-as\server\default\conf\props\jmx-console-users.properties

admin=admin

Thats it. Restart Jboss and I was about to get in to JBOSS JMX. Magically this even fixed the error that I used to get while shutting down Jboss from Eclipse.

Python syntax for "if a or b or c but not all of them"

This is basically a "some (but not all)" functionality (when contrasted with the any() and all() builtin functions).

This implies that there should be Falses and Trues among the results. Therefore, you can do the following:

some = lambda ii: frozenset(bool(i) for i in ii).issuperset((True, False))

# one way to test this is...
test = lambda iterable: (any(iterable) and (not all(iterable))) # see also http://stackoverflow.com/a/16522290/541412

# Some test cases...
assert(some(()) == False)       # all() is true, and any() is false
assert(some((False,)) == False) # any() is false
assert(some((True,)) == False)  # any() and all() are true

assert(some((False,False)) == False)
assert(some((True,True)) == False)
assert(some((True,False)) == True)
assert(some((False,True)) == True)

One advantage of this code is that you only need to iterate once through the resulting (booleans) items.

One disadvantage is that all these truth-expressions are always evaluated, and do not do short-circuiting like the or/and operators.

When should we use mutex and when should we use semaphore

Trying not to sound zany, but can't help myself.

Your question should be what is the difference between mutex and semaphores ? And to be more precise question should be, 'what is the relationship between mutex and semaphores ?'

(I would have added that question but I'm hundred % sure some overzealous moderator would close it as duplicate without understanding difference between difference and relationship.)

In object terminology we can observe that :

observation.1 Semaphore contains mutex

observation.2 Mutex is not semaphore and semaphore is not mutex.

There are some semaphores that will act as if they are mutex, called binary semaphores, but they are freaking NOT mutex.

There is a special ingredient called Signalling (posix uses condition_variable for that name), required to make a Semaphore out of mutex. Think of it as a notification-source. If two or more threads are subscribed to same notification-source, then it is possible to send them message to either ONE or to ALL, to wakeup.

There could be one or more counters associated with semaphores, which are guarded by mutex. The simple most scenario for semaphore, there is a single counter which can be either 0 or 1.

This is where confusion pours in like monsoon rain.

A semaphore with a counter that can be 0 or 1 is NOT mutex.

Mutex has two states (0,1) and one ownership(task). Semaphore has a mutex, some counters and a condition variable.

Now, use your imagination, and every combination of usage of counter and when to signal can make one kind-of-Semaphore.

  1. Single counter with value 0 or 1 and signaling when value goes to 1 AND then unlocks one of the guy waiting on the signal == Binary semaphore

  2. Single counter with value 0 to N and signaling when value goes to less than N, and locks/waits when values is N == Counting semaphore

  3. Single counter with value 0 to N and signaling when value goes to N, and locks/waits when values is less than N == Barrier semaphore (well if they dont call it, then they should.)

Now to your question, when to use what. (OR rather correct question version.3 when to use mutex and when to use binary-semaphore, since there is no comparison to non-binary-semaphore.) Use mutex when 1. you want a customized behavior, that is not provided by binary semaphore, such are spin-lock or fast-lock or recursive-locks. You can usually customize mutexes with attributes, but customizing semaphore is nothing but writing new semaphore. 2. you want lightweight OR faster primitive

Use semaphores, when what you want is exactly provided by it.

If you dont understand what is being provided by your implementation of binary-semaphore, then IMHO, use mutex.

And lastly read a book rather than relying just on SO.

Add floating point value to android resources/values

As described in this link http://droidista.blogspot.in/2012/04/adding-float-value-to-your-resources.html

Declare in dimen.xml

<item name="my_float_value" type="dimen" format="float">9.52</item>

Referencing from xml

@dimen/my_float_value

Referencing from java

TypedValue typedValue = new TypedValue();
getResources().getValue(R.dimen.my_float_value, typedValue, true);
float myFloatValue = typedValue.getFloat();

What is the difference between lower bound and tight bound?

If I were lazy, I could say that binary search on a sorted array is O(n2), O(n3), and O(2n), and I would be technically correct in every case.

We can use o-notation ("little-oh") to denote an upper bound that is not asymptotically tight. Both big-oh and little-oh are similar. But, big-oh is likely used to define asymptotically tight upper bound.

Please run `npm cache clean`

This error can be due to many many things.

The key here seems the hint about error reading. I see you are working on a flash drive or something similar? Try to run the install on a local folder owned by your current user.

You could also try with sudo, that might solve a permission problem if that's the case.

Another reason why it cannot read could be because it has not downloaded correctly, or saved correctly. A little problem in your network could have caused that, and the cache clean would remove the files and force a refetch but that does not solve your problem. That means it would be more on the save part, maybe it didn't save because of permissions, maybe it didn't not save correctly because it was lacking disk space...

How to interactively (visually) resolve conflicts in SourceTree / git

I'm using SourceTree along with TortoiseMerge/Diff, which is very easy and convinient diff/merge tool.

If you'd like to use it as well, then:

  1. Get standalone version of TortoiseMerge/Diff (quite old, since it doesn't ship standalone since version 1.6.7 of TortosieSVN, that is since July 2011). Links and details in this answer.

  2. Unzip TortoiseIDiff.exe and TortoiseMerge.exe to any folder (c:\Program Files (x86)\Atlassian\SourceTree\extras\ in my case).

  3. In SourceTree open Tools > Options > Diff > External Diff / Merge. Select TortoiseMerge in both dropdown lists.

  4. Hit OK and point SourceTree to your location of TortoiseIDiff.exe and TortoiseMerge.exe.

After that, you can select Resolve Conflicts > Launch External Merge Tool from context menu on each conflicted file in your local repository. This will open up TortoiseMerge, where you can easily deal with all the conflicts, you have. Once finished, simply close TortoiseMerge (you don't even need to save changes, this will probably be done automatically) and after few seconds SourceTree should handle that gracefully.

The only problem is, that it automatically creates backup copy, even though proper option is unchecked.

System.Data.OracleClient requires Oracle client software version 8.1.7

Oracle Client version 11 cannot connect to 8i databases. You will need a client in version 10 at most.

How can I iterate over the elements in Hashmap?

Need Key & Value in Iteration

Use entrySet() to iterate through Map and need to access value and key:

Map<String, Person> hm = new HashMap<String, Person>();

hm.put("A", new Person("p1"));
hm.put("B", new Person("p2"));
hm.put("C", new Person("p3"));
hm.put("D", new Person("p4"));
hm.put("E", new Person("p5"));

Set<Map.Entry<String, Person>> set = hm.entrySet();

for (Map.Entry<String, Person> me : set) {
  System.out.println("Key :"+me.getKey() +" Name : "+ me.getValue().getName()+"Age :"+me.getValue().getAge());

}

Need Key in Iteration

If you want just to iterate over keys of map you can use keySet()

for(String key: map.keySet()) {
     Person value = map.get(key); 
}

Need Value in Iteration

If you just want to iterate over values of map you can use values()

for(Person person: map.values()) {

}

AngularJS UI Router - change url without reloading state

i did this but long ago in version: v0.2.10 of UI-router like something like this::

$stateProvider
  .state(
    'home', {
      url: '/home',
      views: {
        '': {
          templateUrl: Url.resolveTemplateUrl('shared/partial/main.html'),
          controller: 'mainCtrl'
        },
      }
    })
  .state('home.login', {
    url: '/login',
    templateUrl: Url.resolveTemplateUrl('authentication/partial/login.html'),
    controller: 'authenticationCtrl'
  })
  .state('home.logout', {
    url: '/logout/:state',
    controller: 'authenticationCtrl'
  })
  .state('home.reservationChart', {
    url: '/reservations/?vw',
    views: {
      '': {
        templateUrl: Url.resolveTemplateUrl('reservationChart/partial/reservationChartContainer.html'),
        controller: 'reservationChartCtrl',
        reloadOnSearch: false
      },
      '[email protected]': {
        templateUrl: Url.resolveTemplateUrl('voucher/partial/viewVoucherContainer.html'),
        controller: 'viewVoucherCtrl',
        reloadOnSearch: false
      },
      '[email protected]': {
        templateUrl: Url.resolveTemplateUrl('voucher/partial/voucherContainer.html'),
        controller: 'voucherCtrl',
        reloadOnSearch: false
      }
    },
    reloadOnSearch: false
  })

LINQ to SQL - How to select specific columns and return strongly typed list

Basically you are doing it the right way. However, you should use an instance of the DataContext for querying (it's not obvious that DataContext is an instance or the type name from your query):

var result = (from a in new DataContext().Persons
              where a.Age > 18
              select new Person { Name = a.Name, Age = a.Age }).ToList();

Apparently, the Person class is your LINQ to SQL generated entity class. You should create your own class if you only want some of the columns:

class PersonInformation {
   public string Name {get;set;}
   public int Age {get;set;}
}

var result = (from a in new DataContext().Persons
              where a.Age > 18
              select new PersonInformation { Name = a.Name, Age = a.Age }).ToList();

You can freely swap var with List<PersonInformation> here without affecting anything (as this is what the compiler does).

Otherwise, if you are working locally with the query, I suggest considering an anonymous type:

var result = (from a in new DataContext().Persons
              where a.Age > 18
              select new { a.Name, a.Age }).ToList();

Note that in all of these cases, the result is statically typed (it's type is known at compile time). The latter type is a List of a compiler generated anonymous class similar to the PersonInformation class I wrote above. As of C# 3.0, there's no dynamic typing in the language.

UPDATE:

If you really want to return a List<Person> (which might or might not be the best thing to do), you can do this:

var result = from a in new DataContext().Persons
             where a.Age > 18
             select new { a.Name, a.Age };

List<Person> list = result.AsEnumerable()
                          .Select(o => new Person {
                                           Name = o.Name, 
                                           Age = o.Age
                          }).ToList();

You can merge the above statements too, but I separated them for clarity.

Properties private set;

Perhaps, you can have them marked as internal, and in this case only classes in your DAL or BL (assuming they are separate dlls) would be able to set it.

You could also supply a constructor that takes the fields and then only exposes them as properties.

What does cmd /C mean?

The part you should be interested in is the /? part, which should solve most other questions you have with the tool.

Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\>cmd /?
Starts a new instance of the Windows XP command interpreter

CMD [/A | /U] [/Q] [/D] [/E:ON | /E:OFF] [/F:ON | /F:OFF] [/V:ON | /V:OFF]
    [[/S] [/C | /K] string]

/C      Carries out the command specified by string and then terminates
/K      Carries out the command specified by string but remains
/S      Modifies the treatment of string after /C or /K (see below)
/Q      Turns echo off
/D      Disable execution of AutoRun commands from registry (see below)
/A      Causes the output of internal commands to a pipe or file to be ANSI
/U      Causes the output of internal commands to a pipe or file to be
        Unicode
/T:fg   Sets the foreground/background colors (see COLOR /? for more info)
/E:ON   Enable command extensions (see below)
/E:OFF  Disable command extensions (see below)
/F:ON   Enable file and directory name completion characters (see below)
/F:OFF  Disable file and directory name completion characters (see below)
/V:ON   Enable delayed environment variable expansion using ! as the
        delimiter. For example, /V:ON would allow !var! to expand the
        variable var at execution time.  The var syntax expands variables
        at input time, which is quite a different thing when inside of a FOR
        loop.
/V:OFF  Disable delayed environment expansion.

JPA - Persisting a One to Many relationship

One way to do that is to set the cascade option on you "One" side of relationship:

class Employee {
   // 

   @OneToMany(cascade = {CascadeType.PERSIST})
   private Set<Vehicles> vehicles = new HashSet<Vehicles>();

   //
}

by this, when you call

Employee savedEmployee = employeeDao.persistOrMerge(newEmployee);

it will save the vehicles too.

JavaFX - create custom button with image

You just need to create your own class inherited from parent. Place an ImageView on that, and on the mousedown and mouse up events just change the images of the ImageView.

public class ImageButton extends Parent {

    private static final Image NORMAL_IMAGE = ...;
    private static final Image PRESSED_IMAGE = ...;

    private final ImageView iv;

    public ImageButton() {
        this.iv = new ImageView(NORMAL_IMAGE);
        this.getChildren().add(this.iv);

        this.iv.setOnMousePressed(new EventHandler<MouseEvent>() {

            public void handle(MouseEvent evt) {
                iv.setImage(PRESSED_IMAGE);
            }

        });

        // TODO other event handlers like mouse up

    } 

}

how to remove the bold from a headline?

<h1><span style="font-weight:bold;">THIS IS</span> A HEADLINE</h1>

But be sure that h1 is marked with

font-weight:normal;

You can also set the style with a id or class attribute.

Please help me convert this script to a simple image slider

Problems only surface when I am I trying to give the first loaded content an active state

Does this mean that you want to add a class to the first button?

$('.o-links').click(function(e) {   // ... }).first().addClass('O_Nav_Current'); 

instead of using IDs for the slider's items and resetting html contents you can use classes and indexes:

CSS:

.image-area {     width: 100%;     height: auto;     display: none; }  .image-area:first-of-type {     display: block; } 

JavaScript:

var $slides = $('.image-area'),     $btns = $('a.o-links');  $btns.on('click', function (e) {     var i = $btns.removeClass('O_Nav_Current').index(this);     $(this).addClass('O_Nav_Current');      $slides.filter(':visible').fadeOut(1000, function () {         $slides.eq(i).fadeIn(1000);     });      e.preventDefault();  }).first().addClass('O_Nav_Current'); 

http://jsfiddle.net/RmF57/

What is the use of hashCode in Java?

The value returned by hashCode() is the object's hash code, which is the object's memory address in hexadecimal.

By definition, if two objects are equal, their hash code must also be equal. If you override the equals() method, you change the way two objects are equated and Object's implementation of hashCode() is no longer valid. Therefore, if you override the equals() method, you must also override the hashCode() method as well.

This answer is from the java SE 8 official tutorial documentation

How to launch another aspx web page upon button click?

Edited and fixed (thanks to Shredder)

If you mean you want to open a new tab, try the below:

protected void Page_Load(object sender, EventArgs e)
{
    this.Form.Target = "_blank";
}

protected void Button1_Click(object sender, EventArgs e)
{

    Response.Redirect("Otherpage.aspx");
}

This will keep the original page to stay open and cause the redirects on the current page to affect the new tab only.

-J

GitHub - failed to connect to github 443 windows/ Failed to connect to gitHub - No Error

Mine was fixed by just using this command :-

      >git config --global http.proxy XXX.XXX.XXX.XXX:ZZ

where XXX.XXX.XXX.XXX is the proxy server address and ZZ is the port number of the proxy server.

There was no need to specify any username or password in my case.

How do I drop table variables in SQL-Server? Should I even do this?

Just Like TempTables, a local table variable is also created in TempDB. The scope of table variable is the batch, stored procedure and statement block in which it is declared. They can be passed as parameters between procedures. They are automatically dropped when you close that session on which you create them.

How do I get the raw request body from the Request.Content object using .net 4 api endpoint

You can get the raw data by calling ReadAsStringAsAsync on the Request.Content property.

string result = await Request.Content.ReadAsStringAsync();

There are various overloads if you want it in a byte or in a stream. Since these are async-methods you need to make sure your controller is async:

public async Task<IHttpActionResult> GetSomething()
{
    var rawMessage = await Request.Content.ReadAsStringAsync();
    // ...
    return Ok();
}

EDIT: if you're receiving an empty string from this method, it means something else has already read it. When it does that, it leaves the pointer at the end. An alternative method of doing this is as follows:

public IHttpActionResult GetSomething()
{
    var reader = new StreamReader(Request.Body);
    reader.BaseStream.Seek(0, SeekOrigin.Begin); 
    var rawMessage = reader.ReadToEnd();

    return Ok();
}

In this case, your endpoint doesn't need to be async (unless you have other async-methods)

Sum one number to every element in a list (or array) in Python

If you don't want list comprehensions:

a = [1,1,1,1,1]
b = []
for i in a:
    b.append(i+1)

std::enable_if to conditionally compile a member function

Here is my minimalist example, using a macro. Use double brackets enable_if((...)) when using more complex expressions.

template<bool b, std::enable_if_t<b, int> = 0>
using helper_enable_if = int;

#define enable_if(value) typename = helper_enable_if<value>

struct Test
{
     template<enable_if(false)>
     void run();
}

Jenkins Host key verification failed

Change to the jenkins user and run the command manually:

git ls-remote -h [email protected]:person/projectmarket.git HEAD

You will get the standard SSH warning when first connecting to a new host via SSH:

The authenticity of host 'bitbucket.org (207.223.240.181)' can't be established.
RSA key fingerprint is 97:8c:1b:f2:6f:14:6b:5c:3b:ec:aa:46:46:74:7c:40.
Are you sure you want to continue connecting (yes/no)?

Type yes and press Enter. The host key for bitbucket.org will now be added to the ~/.ssh/known_hosts file and you won't get this error in Jenkins anymore.

Delete all duplicate rows Excel vba

The duplicate values in any column can be deleted with a simple for loop.

Sub remove()
Dim a As Long
For a = Cells(Rows.Count, 1).End(xlUp).Row To 1 Step -1
If WorksheetFunction.CountIf(Range("A1:A" & a), Cells(a, 1)) > 1 Then Rows(a).Delete
Next
End Sub

Run jar file with command line arguments

For the question

How can i run a jar file in command prompt but with arguments

.

To pass arguments to the jar file at the time of execution

java -jar myjar.jar arg1 arg2

In the main() method of "Main-Class" [mentioned in the manifest.mft file]of your JAR file. you can retrieve them like this:

String arg1 = args[0];
String arg2 = args[1];

Stop setInterval call in JavaScript

Use setTimeOut to stop the interval after some time.

var interVal = setInterval(function(){console.log("Running")  }, 1000);
 setTimeout(function (argument) {
    clearInterval(interVal);
 },10000);

Running unittest with typical test directory structure

A simple solution for *nix based systems (macOS, Linux); and probably also Git bash on Windows.

PYTHONPATH=$PWD python test/test_antigravity.py

print statement easily works, unlike pytest test/test_antigravity.py. A perfect way for "scripts", but not really for unittesting.

Of course, I want to do a proper automated testing, I would consider pytest with appropriate settings.

How to run script as another user without password?

try running:

su -c "Your command right here" -s /bin/sh username

This will run the command as username given that you have permissions to sudo as that user.

Creating a directory in /sdcard fails

If this is happening to you with Android 6 and compile target >= 23, don't forget that we are now using runtime permissions. So giving permissions in the manifest is not enough anymore.

Returning a C string from a function

You can create the array in the caller, which is the main function, and pass the array to the callee which is your myFunction(). Thus myFunction can fill the string into the array. However, you need to declare myFunction() as

char* myFunction(char * buf, int buf_len){
  strncpy(buf, "my string", buf_len);
  return buf;
}

And in main function, myFunction should be called in this way:

char array[51];
memset(array, 0, 51); /* All bytes are set to '\0' */
printf("%s", myFunction(array, 50)); /* The buf_len argument  is 50, not 51. This is to make sure the string in buf is always null-terminated (array[50] is always '\0') */

However, a pointer is still used.

How to extract the file name from URI returned from Intent.ACTION_GET_CONTENT?

Taken from Retrieving File information | Android developers

Retrieving a File's name.

private String queryName(ContentResolver resolver, Uri uri) {
    Cursor returnCursor =
            resolver.query(uri, null, null, null, null);
    assert returnCursor != null;
    int nameIndex = returnCursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
    returnCursor.moveToFirst();
    String name = returnCursor.getString(nameIndex);
    returnCursor.close();
    return name;
}

Sorting dropdown alphabetically in AngularJS

var module = angular.module("example", []);

module.controller("orderByController", function ($scope) {
    $scope.orderByValue = function (value) {
        return value;
    };

    $scope.items = ["c", "b", "a"];
    $scope.objList = [
        {
            "name": "c"
        }, {
            "name": "b"
        }, {
            "name": "a"
        }];
        $scope.item = "b";
    });

http://jsfiddle.net/Nfv42/65/

PHP reindex array?

This might not be the simplest answer as compared to using array_values().

Try this

$array = array( 0 => 'string1', 2 => 'string2', 4 => 'string3', 5 => 'string4');
$arrays =$array;
print_r($array);
$array=array();
$i=0;
    foreach($arrays as $k => $item)
    {
    $array[$i]=$item;
        unset($arrays[$k]);
        $i++;

    }

print_r($array);

Demo

ExpressionChangedAfterItHasBeenCheckedError: Expression has changed after it was checked. Previous value: 'undefined'

If you are using <ng-content> with *ngIf you are bound to fall into this loop.

Only way out I found was to change *ngIf to display:none functionality

What is the worst real-world macros/pre-processor abuse you've ever come across?

Try to debug big project that really loves macros, and there is a lot of macros that calls other macros that calls other macros etc etc. (5-10 levels of macros was not that uncommon)

And then top it up with a lot of #ifdef this macrot #else that macro, so if you follow the code it like a tree of different paths it can go.

The only solution is most cases was to precompile and read that instead....

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

  1. The optimal solution could be to try to transform your solution into a form where you don't need to have two readers open at a time. Ideally it could be a single query. I don't have time to do that now.
  2. If your problem is so special that you really need to have more readers open simultaneously, and your requirements allow not older than SQL Server 2005 DB backend, then the magic word is MARS (Multiple Active Result Sets). http://msdn.microsoft.com/en-us/library/ms345109%28v=SQL.90%29.aspx. Bob Vale's linked topic's solution shows how to enable it: specify MultipleActiveResultSets=true in your connection string. I just tell this as an interesting possibility, but you should rather transform your solution.

    • in order to avoid the mentioned SQL injection possibility, set the parameters to the SQLCommand itself instead of embedding them into the query string. The query string should only contain the references to the parameters what you pass into the SqlCommand.

Spring MVC @PathVariable with dot (.) is getting truncated

In Spring Boot Rest Controller, I have resolved these by following Steps:

RestController :

@GetMapping("/statusByEmail/{email:.+}/")
public String statusByEmail(@PathVariable(value = "email") String email){
  //code
}

And From Rest Client:

Get http://mywebhook.com/statusByEmail/[email protected]/

Nodejs convert string into UTF-8

Use the utf8 module from npm to encode/decode the string.

Installation:

npm install utf8

In a browser:

<script src="utf8.js"></script>

In Node.js:

const utf8 = require('utf8');

API:

Encode:

utf8.encode(string)

Encodes any given JavaScript string (string) as UTF-8, and returns the UTF-8-encoded version of the string. It throws an error if the input string contains a non-scalar value, i.e. a lone surrogate. (If you need to be able to encode non-scalar values as well, use WTF-8 instead.)

// U+00A9 COPYRIGHT SIGN; see http://codepoints.net/U+00A9
utf8.encode('\xA9');
// ? '\xC2\xA9'
// U+10001 LINEAR B SYLLABLE B038 E; see http://codepoints.net/U+10001
utf8.encode('\uD800\uDC01');
// ? '\xF0\x90\x80\x81'

Decode:

utf8.decode(byteString)

Decodes any given UTF-8-encoded string (byteString) as UTF-8, and returns the UTF-8-decoded version of the string. It throws an error when malformed UTF-8 is detected. (If you need to be able to decode encoded non-scalar values as well, use WTF-8 instead.)

utf8.decode('\xC2\xA9');
// ? '\xA9'

utf8.decode('\xF0\x90\x80\x81');
// ? '\uD800\uDC01'
// ? U+10001 LINEAR B SYLLABLE B038 E

Resources

Slicing of a NumPy 2d array, or how do I extract an mxm submatrix from an nxn array (n>m)?

As Sven mentioned, x[[[0],[2]],[1,3]] will give back the 0 and 2 rows that match with the 1 and 3 columns while x[[0,2],[1,3]] will return the values x[0,1] and x[2,3] in an array.

There is a helpful function for doing the first example I gave, numpy.ix_. You can do the same thing as my first example with x[numpy.ix_([0,2],[1,3])]. This can save you from having to enter in all of those extra brackets.

Excel 2007: How to display mm:ss format not as a DateTime (e.g. 73:07)?

Excel shows 24:03 as 3 minutes when you format it as time, because 24:03 is the same as 12:03 AM (in military time).

Use General Format to Add Times

Instead of trying to format as Time, use the General Format and the following formula:

=number of minutes + (number of seconds / 60)

Ex: for 24 minutes and 3 seconds:

=24+3/60

This will give you a value of 24.05.

Do this for each time period. Let's say you enter this formula in cells A1 and A2. Then, to get the total sum of elapsed time, use this formula in cell A3:

=INT(A1+A2)+MOD(A1+A2,1)

Convert back to minutes and seconds

If you put =24+3/60 into each cell, you will have a value of 48.1 in cell A3.

Now you need to convert this back to minutes and seconds. Use the following formula in cell A4:

=MOD(A3,1)*60

This takes the decimal portion and multiples it by 60. Remember, we divided by 60 in the beginning, so to convert it back to seconds we need to multiply.

You could have also done this separately, i.e. in cell A3 use this formula:

=INT(A1+A2)

and this formula in cell A4:

=MOD(A1+A2,1)*60

Here's a screenshot showing the final formulas:

adding times

Convert Newtonsoft.Json.Linq.JArray to a list of specific object type

The API return value in my case as shown here:

{
  "pageIndex": 1,
  "pageSize": 10,
  "totalCount": 1,
  "totalPageCount": 1,
  "items": [
    {
      "firstName": "Stephen",
      "otherNames": "Ebichondo",
      "phoneNumber": "+254721250736",
      "gender": 0,
      "clientStatus": 0,
      "dateOfBirth": "1979-08-16T00:00:00",
      "nationalID": "21734397",
      "emailAddress": "[email protected]",
      "id": 1,
      "addedDate": "2018-02-02T00:00:00",
      "modifiedDate": "2018-02-02T00:00:00"
    }
  ],
  "hasPreviousPage": false,
  "hasNextPage": false
}

The conversion of the items array to list of clients was handled as shown here:

 if (responseMessage.IsSuccessStatusCode)
        {
            var responseData = responseMessage.Content.ReadAsStringAsync().Result;
            JObject result = JObject.Parse(responseData);

            var clientarray = result["items"].Value<JArray>();
            List<Client> clients = clientarray.ToObject<List<Client>>();
            return View(clients);
        }

How do I connect to this localhost from another computer on the same network?

If you are on Windows, use ipconfig to get the local IPv4 address, and then specify that under your Apache configuration file: httpd.conf, like:

Listen: 10.20.30.40:80

Restart your Apache server and test it from other computer on the network.

How to print (using cout) a number in binary form?

Reusable function:

template<typename T>
static std::string toBinaryString(const T& x)
{
    std::stringstream ss;
    ss << std::bitset<sizeof(T) * 8>(x);
    return ss.str();
}

Usage:

int main(){
  uint16_t x=8;
  std::cout << toBinaryString(x);
}

This works with all kind of integers.

Plot different DataFrames in the same figure

Just to enhance @adivis12 answer, you don't need to do the if statement. Put it like this:

fig, ax = plt.subplots()
for BAR in dict_of_dfs.keys():
    dict_of_dfs[BAR].plot(ax=ax)

Laravel form html with PUT method for PUT routes

Just use like this somewhere inside the form

@method('PUT')

What is the "__v" field in Mongoose

For remove in NestJS need to add option to Shema() decorator

@Schema({ versionKey: false })

Bootstrap Carousel Full Screen

I found an answer on the startbootstrap.com. Try this code:

CSS

html,
body {
    height: 100%;
}

.carousel,
.item,
.active {
    height: 100%;
}


.carousel-inner {
    height: 100%;
}

/* Background images are set within the HTML using inline CSS, not here */

.fill {
    width: 100%;
    height: 100%;
    background-position: center;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    background-size: cover;
    -o-background-size: cover;
}

footer {
    margin: 50px 0;
}

HTML

   <div class="carousel-inner">
        <div class="item active">
            <!-- Set the first background image using inline CSS below. -->
            <div class="fill" style="background-image:url('http://placehold.it/1900x1080&text=Slide One');"></div>
            <div class="carousel-caption">
                <h2>Caption 1</h2>
            </div>
        </div>
        <div class="item">
            <!-- Set the second background image using inline CSS below. -->
            <div class="fill" style="background-image:url('http://placehold.it/1900x1080&text=Slide Two');"></div>
            <div class="carousel-caption">
                <h2>Caption 2</h2>
            </div>
        </div>
        <div class="item">
            <!-- Set the third background image using inline CSS below. -->
            <div class="fill" style="background-image:url('http://placehold.it/1900x1080&text=Slide Three');"></div>
            <div class="carousel-caption">
                <h2>Caption 3</h2>
            </div>
        </div>
    </div>

Source

Django - Did you forget to register or load this tag?

did you try this

{% load games_tags %} 

at the top instead of pygmentize?

How to round the double value to 2 decimal points?

public static double addDoubles(double a, double b) {
        BigDecimal A = new BigDecimal(a + "");
        BigDecimal B = new BigDecimal(b + "");
        return A.add(B).setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue();
    }

MySQL DISTINCT on a GROUP_CONCAT()

Using DISTINCT will work

SELECT GROUP_CONCAT(DISTINCT(categories) SEPARATOR ' ') FROM table

REf:- this

What is the most effective way for float and double comparison?

How about this?

template<typename T>
bool FloatingPointEqual( T a, T b ) { return !(a < b) && !(b < a); }

I've seen various approaches - but never seen this, so I'm curious to hear of any comments too!

Foreach loop in C++ equivalent of C#

Using boost is the best option as it helps you to provide a neat and concise code, but if you want to stick to STL

void listbox_add(const char* item, ListBox &lb)
{
    lb.add(item);
}

int foo()
{
    const char* starr[] = {"ram", "mohan", "sita"};
    ListBox listBox;
    std::for_each(starr,
                  starr + sizeof(starr)/sizeof(char*),
                  std::bind2nd(std::ptr_fun(&listbox_add), listBox));

}

What are all the differences between src and data-src attributes?

data-src attribute is part of the data-* attributes collection introduced in HTML5. data-src allow us to store extra data that have no meaning to the browser but that can be use by Javascript Code or CSS rules.

Convert canvas to PDF

You can achieve this by utilizing the jsPDF library and the toDataURL function.

I made a little demonstration:

_x000D_
_x000D_
var canvas = document.getElementById('myCanvas');_x000D_
var context = canvas.getContext('2d');_x000D_
_x000D_
// draw a blue cloud_x000D_
context.beginPath();_x000D_
context.moveTo(170, 80);_x000D_
context.bezierCurveTo(130, 100, 130, 150, 230, 150);_x000D_
context.bezierCurveTo(250, 180, 320, 180, 340, 150);_x000D_
context.bezierCurveTo(420, 150, 420, 120, 390, 100);_x000D_
context.bezierCurveTo(430, 40, 370, 30, 340, 50);_x000D_
context.bezierCurveTo(320, 5, 250, 20, 250, 50);_x000D_
context.bezierCurveTo(200, 5, 150, 20, 170, 80);_x000D_
context.closePath();_x000D_
context.lineWidth = 5;_x000D_
context.fillStyle = '#8ED6FF';_x000D_
context.fill();_x000D_
context.strokeStyle = '#0000ff';_x000D_
context.stroke();_x000D_
_x000D_
download.addEventListener("click", function() {_x000D_
  // only jpeg is supported by jsPDF_x000D_
  var imgData = canvas.toDataURL("image/jpeg", 1.0);_x000D_
  var pdf = new jsPDF();_x000D_
_x000D_
  pdf.addImage(imgData, 'JPEG', 0, 0);_x000D_
  pdf.save("download.pdf");_x000D_
}, false);
_x000D_
<script src="//cdnjs.cloudflare.com/ajax/libs/jspdf/1.3.3/jspdf.min.js"></script>_x000D_
_x000D_
_x000D_
<canvas id="myCanvas" width="578" height="200"></canvas>_x000D_
<button id="download">download</button>
_x000D_
_x000D_
_x000D_

"Are you missing an assembly reference?" compile error - Visual Studio

I bumped the answer that pointed me in the right direction, but...

For those who are using Visual C++:

If you need to turn off auto-increment of the version, you can change this value in the "AssemblyInfo.cpp" file (all CLR projects have one). Give it a real version number without the asterisk and it will work the way you want it to.

Just don't forget to implement your own version-control on your assembly!

iterating and filtering two lists using java 8

@DSchmdit answer worked for me. I would like to add on that. So my requirement was to filter a file based on some configurations stored in the table. The file is first retrieved and collected as list of dtos. I receive the configurations from the db and store it as another list. This is how I made the filtering work with streams

    List<FPRSDeferralModel> modelList = Files
            .lines(Paths.get("src/main/resources/rootFiles/XXXXX.txt")).parallel().parallel()
            .map(line -> {
                FileModel fileModel= new FileModel();
                line = line.trim();
                if (line != null && !line.isEmpty()) {
                    System.out.println("line" + line);
                    fileModel.setPlanId(Long.parseLong(line.substring(0, 5)));
                    fileModel.setDivisionList(line.substring(15, 30));
                    fileModel.setRegionList(line.substring(31, 50));
                    Map<String, String> newMap = new HashedMap<>();
                    newMap.put("other", line.substring(51, 80));
                    fileModel.setOtherDetailsMap(newMap);

                }
                return fileModel;
            }).collect(Collectors.toList());

    for (FileModel model : modelList) {
        System.out.println("model:" + model);
    }

    DbConfigModelList respList = populate();
    System.out.println("after populate");
    List<DbConfig> respModelList = respList.getFeedbackResponseList();


    Predicate<FileModel> somePre = s -> respModelList.stream().anyMatch(respitem -> {

        System.out.println("sinde respitem:"+respitem.getPrimaryConfig().getPlanId());
        System.out.println("s.getPlanid()"+s.getPlanId());
        System.out.println("s.getPlanId() == respitem.getPrimaryConfig().getPlanId():"+
        (s.getPlanId().compareTo(respitem.getPrimaryConfig().getPlanId())));
        return s.getPlanId().compareTo(respitem.getPrimaryConfig().getPlanId()) == 0
                && (s.getSsnId() != null);
    });



 final List<FileModel> finalList =  modelList.stream().parallel().filter(somePre).collect(Collectors.toList());

 finalList.stream().forEach(item -> {
     System.out.println("filtered item is:"+item);
 });

The details are in the implementation of filter predicates. This proves much more perfomant over iterating over loops and filtering out

Android: No Activity found to handle Intent error? How it will resolve

in my case, i was sure that the action is correct, but i was passing wrong URL, i passed the website link without the http:// in it's beginning, so it caused the same issue, here is my manifest (part of it)

<activity
        android:name=".MyBrowser"
        android:label="MyBrowser Activity" >
        <intent-filter>
            <action android:name="android.intent.action.VIEW" />
            <action android:name="com.dsociety.activities.MyBrowser" />

            <category android:name="android.intent.category.DEFAULT" />

            <data android:scheme="http" />
        </intent-filter>
    </activity>

when i code the following, the same Exception is thrown at run time :

Intent intent = new Intent();
intent.setAction("com.dsociety.activities.MyBrowser");
intent.setData(Uri.parse("www.google.com"));    // should be http://www.google.com
startActivity(intent);

z-index not working with fixed positioning

This question can be solved in a number of ways, but really, knowing the stacking rules allows you to find the best answer that works for you.

Solutions

The <html> element is your only stacking context, so just follow the stacking rules inside a stacking context and you will see that elements are stacked in this order

  1. The stacking context’s root element (the <html> element in this case)
  2. Positioned elements (and their children) with negative z-index values (higher values are stacked in front of lower values; elements with the same value are stacked according to appearance in the HTML)
  3. Non-positioned elements (ordered by appearance in the HTML)
  4. Positioned elements (and their children) with a z-index value of auto (ordered by appearance in the HTML)
  5. Positioned elements (and their children) with positive z-index values (higher values are stacked in front of lower values; elements with the same value are stacked according to appearance in the HTML)

So you can

  1. set a z-index of -1, for #under positioned -ve z-index appear behind non-positioned #over element
  2. set the position of #over to relative so that rule 5 applies to it

The Real Problem

Developers should know the following before trying to change the stacking order of elements.

  1. When a stacking context is formed
    • By default, the <html> element is the root element and is the first stacking context
  2. Stacking order within a stacking context

The Stacking order and stacking context rules below are from this link

When a stacking context is formed

  • When an element is the root element of a document (the <html> element)
  • When an element has a position value other than static and a z-index value other than auto
  • When an element has an opacity value less than 1
  • Several newer CSS properties also create stacking contexts. These include: transforms, filters, css-regions, paged media, and possibly others. https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Positioning/Understanding_z_index/The_stacking_context
  • As a general rule, it seems that if a CSS property requires rendering in an offscreen context, it must create a new stacking context.

Stacking Order within a Stacking Context

The order of elements:

  1. The stacking context’s root element (the <html> element is the only stacking context by default, but any element can be a root element for a stacking context, see rules above)
    • You cannot put a child element behind a root stacking context element
  2. Positioned elements (and their children) with negative z-index values (higher values are stacked in front of lower values; elements with the same value are stacked according to appearance in the HTML)
  3. Non-positioned elements (ordered by appearance in the HTML)
  4. Positioned elements (and their children) with a z-index value of auto (ordered by appearance in the HTML)
  5. Positioned elements (and their children) with positive z-index values (higher values are stacked in front of lower values; elements with the same value are stacked according to appearance in the HTML)

Blue and Purple Default links, how to remove?

REMOVE DEFAULT LINK SOLVED that :visited thing is css.... you just go to your HTML and add a simple

< a href="" style="text-decoration: none" > < /a>

... thats the way html pages used to be

How do I access nested HashMaps in Java?

I prefer creating a custom map that extends HashMap. Then just override get() to add extra logic so that if the map doesnt contain your key. It will a create a new instance of the nested map, add it, then return it.

public class KMap<K, V> extends HashMap<K, V> {

    public KMap() {
        super();
    }

    @Override
    public V get(Object key) {
        if (this.containsKey(key)) {
            return super.get(key);
        } else {
            Map<K, V> value = new KMap<K, V>();
            super.put((K)key, (V)value);
            return (V)value;
        }
    }
}

Now you can use it like so:

Map<Integer, Map<Integer, Map<String, Object>>> nestedMap = new KMap<Integer, Map<Integer, Map<String, Object>>>();

Map<String, Object> map = (Map<String, Object>) nestedMap.get(1).get(2);
Object obj= new Object();
map.put(someKey, obj);

Purpose of "%matplotlib inline"

TL;DR

%matplotlib inline - Displays output inline


IPython kernel has the ability to display plots by executing code. The IPython kernel is designed to work seamlessly with the matplotlib plotting library to provide this functionality.

%matplotlib is a magic command which performs the necessary behind-the-scenes setup for IPython to work correctly hand-in-hand with matplotlib; it does not execute any Python import commands, that is, no names are added to the namespace.

Display output in separate window

%matplotlib

Display output inline

(available only for the Jupyter Notebook and the Jupyter QtConsole)

%matplotlib inline

Display with interactive backends

(valid values 'GTK3Agg', 'GTK3Cairo', 'MacOSX', 'nbAgg', 'Qt4Agg', 'Qt4Cairo', 'Qt5Agg', 'Qt5Cairo', 'TkAgg', 'TkCairo', 'WebAgg', 'WX', 'WXAgg', 'WXCairo', 'agg', 'cairo', 'pdf', 'pgf', 'ps', 'svg', 'template')

%matplotlib gtk

Example - GTK3Agg - An Agg rendering to a GTK 3.x canvas (requires PyGObject and pycairo or cairocffi).

More details about matplotlib interactive backends: here


Starting with IPython 5.0 and matplotlib 2.0 you can avoid the use of IPython’s specific magic and use matplotlib.pyplot.ion()/matplotlib.pyplot.ioff() which have the advantages of working outside of IPython as well.

Refer: IPython Rich Output - Interactive Plotting

Maven and adding JARs to system scope

Try this configuration. It worked for me:

<plugin>
    <artifactId>maven-war-plugin</artifactId>
    <version>2.4</version>
    <configuration>
        <warSourceDirectory>mywebRoot</warSourceDirectory>
        <warSourceExcludes>source\**,build\**,dist\**,WEB-INF\lib\*,
            WEB-INF\classes\**,build.*
        </warSourceExcludes>
        <webXml>myproject/source/deploiement/web.xml</webXml>
        <webResources>
            <resource>
                <directory>mywebRoot/WEB-INF/lib</directory>
                <targetPath>WEB-INF/lib</targetPath>
                <includes>
                        <include>mySystemJar1.jar.jar</include>
                         <include>mySystemJar2.jar</include>
                   </includes>
            </resource>
        </webResources>
    </configuration>
</plugin>

How do I "decompile" Java class files?

Here's a list of decompilers as of Feb 2015:

Procyon, open-source, https://bitbucket.org/mstrobel/procyon/wiki/Java%20Decompiler

CFR, free, no source-code available, http://www.benf.org/other/cfr/

JD, free for non-commercial use only, http://jd.benow.ca/

Fernflower, open-source, https://github.com/fesh0r/fernflower,

JAD – given here only for historical reason. Free, no source-code available, http://varaneckas.com/jad/ Outdated, unsupported and does not decompile correctly Java 5 and later.

You may test above-mentioned decompilers online, no installation required and make your own educated choice.

Java decompilers in the cloud: http://www.javadecompilers.com/

How to do tag wrapping in VS code?

imo there's a better answer for this using Snippets

Create a snippet with a definition like this:

"name_of_your_snippet": {
    "scope": "javascript,html",
    "prefix": "name_of_your_snippet",
    "body": "<${0:b}>$TM_SELECTED_TEXT</${0:b}>"
}

Then bind it to a key in keybindings.json E.g. like this:

{ 
    "key": "alt+w",
    "command": "editor.action.insertSnippet",
    "args": { "name": "name_of_your_snippet" }
}

I think this should give you exactly the same result as htmltagwrap but without having to install an extension.

It will insert tags around selected text, defaults to <b> tag & selects the tag so typing lets you change it.

If you want to use a different default tag just change the b in the body property of the snippet.

Get difference between two lists

def diffList(list1, list2):     # returns the difference between two lists.
    if len(list1) > len(list2):
        return (list(set(list1) - set(list2)))
    else:
        return (list(set(list2) - set(list1)))

e.g. if list1 = [10, 15, 20, 25, 30, 35, 40] and list2 = [25, 40, 35] then the returned list will be output = [10, 20, 30, 15]

How do I type a TAB character in PowerShell?

In the Windows command prompt you can disable tab completion, by launching it thusly:

cmd.exe /f:off

Then the tab character will be echoed to the screen and work as you expect. Or you can disable the tab completion character, or modify what character is used for tab completion by modifying the registry.

The cmd.exe help page explains it:

You can enable or disable file name completion for a particular invocation of CMD.EXE with the /F:ON or /F:OFF switch. You can enable or disable completion for all invocations of CMD.EXE on a machine and/or user logon session by setting either or both of the following REG_DWORD values in the registry using REGEDIT.EXE:

HKEY_LOCAL_MACHINE\Software\Microsoft\Command Processor\CompletionChar
HKEY_LOCAL_MACHINE\Software\Microsoft\Command Processor\PathCompletionChar

    and/or

HKEY_CURRENT_USER\Software\Microsoft\Command Processor\CompletionChar
HKEY_CURRENT_USER\Software\Microsoft\Command Processor\PathCompletionChar

with the hex value of a control character to use for a particular function (e.g. 0x4 is Ctrl-D and 0x6 is Ctrl-F). The user specific settings take precedence over the machine settings. The command line switches take precedence over the registry settings.

If completion is enabled with the /F:ON switch, the two control characters used are Ctrl-D for directory name completion and Ctrl-F for file name completion. To disable a particular completion character in the registry, use the value for space (0x20) as it is not a valid control character.

Algorithm to find all Latitude Longitude locations within a certain distance from a given Lat Lng location

Tank´s Yogihosting

I have in my database one goups of tables from Open Streep Maps and I tested successful.

Distance work fine in meters.

SET @orig_lat=-8.116137;
SET @orig_lon=-34.897488;
SET @dist=1000;

SELECT *,(((acos(sin((@orig_lat*pi()/180)) * sin((dest.latitude*pi()/180))+cos((@orig_lat*pi()/180))*cos((dest.latitude*pi()/180))*cos(((@orig_lon-dest.longitude)*pi()/180))))*180/pi())*60*1.1515*1609.344) as distance FROM nodes AS dest HAVING distance < @dist ORDER BY distance ASC LIMIT 100;

GROUP BY having MAX date

Fast and easy with HAVING:

SELECT * FROM tblpm n 
FROM tblpm GROUP BY control_number 
HAVING date_updated=MAX(date_updated);

In the context of HAVING, MAX finds the max of each group. Only the latest entry in each group will satisfy date_updated=max(date_updated). If there's a tie for latest within a group, both will pass the HAVING filter, but GROUP BY means that only one will appear in the returned table.

Tomcat: java.lang.IllegalArgumentException: Invalid character found in method name. HTTP method names must be tokens

This exception can occur when you try to execute HTTPS request from client on endpoint which isn't HTTPS enabled. Client will encrypt request data when server is expecting raw data.

selectOneMenu ajax events

You could check whether the value of your selectOneMenu component belongs to the list of subjects.

Namely:

public void subjectSelectionChanged() {
    // Cancel if subject is manually written
    if (!subjectList.contains(aktNachricht.subject)) { return; }
    // Write your code here in case the user selected (or wrote) an item of the list
    // ....
}

Supposedly subjectList is a collection type, like ArrayList. Of course here your code will run in case the user writes an item of your selectOneMenu list.

How to escape single quotes in MySQL

If you are using PHP, just use the addslashes() function.

PHP Manual addslashes

C# How to determine if a number is a multiple of another?

there are some syntax errors to your program heres a working code;

#include<stdio.h>
int main()
{
int a,b;
printf("enter any two number\n");
scanf("%d%d",&a,&b);
if (a%b==0){
printf("this is  multiple number");
}
else if (b%a==0){
printf("this is multiple number");
}
else{
printf("this is not multiple number");
return 0;
}

}

Number of elements in a javascript object

function count(){
    var c= 0;
    for(var p in this) if(this.hasOwnProperty(p))++c;
    return c;
}

var O={a: 1, b: 2, c: 3};

count.call(O);

How can I connect to MySQL on a WAMP server?

Change localhost:8080 to localhost:3306.

Easy way to pull latest of all git submodules

Here is the command-line to pull from all of your git repositories whether they're or not submodules:

ROOT=$(git rev-parse --show-toplevel 2> /dev/null)
find "$ROOT" -name .git -type d -execdir git pull -v ';'

If you running it in your top git repository, you can replace "$ROOT" into ..

What is the difference between a URI, a URL and a URN?

URIs came about from the need to identify resources on the Web, and other Internet resources such as electronic mailboxes in a uniform and coherent way. So, one can introduce a new type of widget: URIs to identify widget resources or use tel: URIs to have web links cause telephone calls to be made when invoked.

Some URIs provide information to locate a resource (such as a DNS host name and a path on that machine), while some are used as pure resource names. The URL is reserved for identifiers that are resource locators, including 'http' URLs such as http://stackoverflow.com, which identifies the web page at the given path on the host. Another example is 'mailto' URLs, such as mailto:[email protected], which identifies the mailbox at the given address.

URNs are URIs that are used as pure resource names rather than locators. For example, the URI: mid:[email protected] is a URN that identifies the email message containing it in its 'Message-Id' field. The URI serves to distinguish that message from any other email message. But it does not itself provide the message's address in any store.

Platform.runLater and Task in JavaFX

One reason to use an explicite Platform.runLater() could be that you bound a property in the ui to a service (result) property. So if you update the bound service property, you have to do this via runLater():

In UI thread also known as the JavaFX Application thread:

...    
listView.itemsProperty().bind(myListService.resultProperty());
...

in Service implementation (background worker):

...
Platform.runLater(() -> result.add("Element " + finalI));
...

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

I am assuming that you have used height attribute at both so i am comparing it with a height left do it with JavaScript.

var right=document.getElementById('rightdiv').style.height;
var left=document.getElementById('leftdiv').style.height;
if(left>right)
{
    document.getElementById('rightdiv').style.height=left;
}
else
{
    document.getElementById('leftdiv').style.height=right;
}

Another idea can be found here HTML/CSS: Making two floating divs the same height.

How can I jump to class/method definition in Atom text editor?

Check out goto package:

This is a replacement for Atom’s built-in symbols-view package that uses Atom’s own syntax files to identify symbols rather than ctags. The ctags project is very useful but it is never going to keep up with all of the new Atom syntaxes that will be created as Atom grows.

Commands:

  • cmd-r - Goto File Symbol
  • cmd-shift-r - Goto Project Symbol
  • cmd-alt-down - Goto Declaration
  • Rebuild Index
  • Invalidate Index

Link here: https://atom.io/packages/goto (or search "goto" in package installer)

The type arguments for method cannot be inferred from the usage

Now my aim was to have one pair with an base type and a type definition (Requirement A). For the type definition I want to use inheritance (Requirement B). The use should be possible, without explicite knowledge over the base type (Requirement C).

After I know now that the gernic constraints are not used for solving the generic return type, I experimented a little bit:

Ok let's introducte Get2:

class ServiceGate
{
    public IAccess<C, T> Get1<C, T>(C control) where C : ISignatur<T>
    {
        throw new NotImplementedException();
    }

    public IAccess<ISignatur<T>, T> Get2<T>(ISignatur<T> control)
    {
        throw new NotImplementedException();
    }
}

class Test
{
    static void Main()
    {
        ServiceGate service = new ServiceGate();
        //var bla1 = service.Get1(new Signatur()); // CS0411
        var bla = service.Get2(new Signatur()); // Works
    }
}

Fine, but this solution reaches not requriement B.

Next try:

class ServiceGate
{
    public IAccess<C, T> Get3<C, T>(C control, ISignatur<T> iControl) where C : ISignatur<T>
    {
        throw new NotImplementedException();
    }

}

class Test
{
    static void Main()
    {
        ServiceGate service = new ServiceGate();
        //var bla1 = service.Get1(new Signatur()); // CS0411
        var bla = service.Get2(new Signatur()); // Works
        var c = new Signatur();
        var bla3 = service.Get3(c, c); // Works!! 
    }
}

Nice! Now the compiler can infer the generic return types. But i don't like it. Other try:

class IC<A, B>
{
    public IC(A a, B b)
    {
        Value1 = a;
        Value2 = b;
    }

    public A Value1 { get; set; }

    public B Value2 { get; set; }
}

class Signatur : ISignatur<bool>
{
    public string Test { get; set; }

    public IC<Signatur, ISignatur<bool>> Get()
    {
        return new IC<Signatur, ISignatur<bool>>(this, this);
    }
}

class ServiceGate
{
    public IAccess<C, T> Get4<C, T>(IC<C, ISignatur<T>> control) where C : ISignatur<T>
    {
        throw new NotImplementedException();
    }
}

class Test
{
    static void Main()
    {
        ServiceGate service = new ServiceGate();
        //var bla1 = service.Get1(new Signatur()); // CS0411
        var bla = service.Get2(new Signatur()); // Works
        var c = new Signatur();
        var bla3 = service.Get3(c, c); // Works!!
        var bla4 = service.Get4((new Signatur()).Get()); // Better...
    }
}

My final solution is to have something like ISignature<B, C>, where B ist the base type and C the definition...

Android file chooser

EDIT (02 Jan 2012):

I created a small open source Android Library Project that streamlines this process, while also providing a built-in file explorer (in case the user does not have one present). It's extremely simple to use, requiring only a few lines of code.

You can find it at GitHub: aFileChooser.


ORIGINAL

If you want the user to be able to choose any file in the system, you will need to include your own file manager, or advise the user to download one. I believe the best you can do is look for "openable" content in an Intent.createChooser() like this:

private static final int FILE_SELECT_CODE = 0;

private void showFileChooser() {
    Intent intent = new Intent(Intent.ACTION_GET_CONTENT); 
    intent.setType("*/*"); 
    intent.addCategory(Intent.CATEGORY_OPENABLE);

    try {
        startActivityForResult(
                Intent.createChooser(intent, "Select a File to Upload"),
                FILE_SELECT_CODE);
    } catch (android.content.ActivityNotFoundException ex) {
        // Potentially direct the user to the Market with a Dialog
        Toast.makeText(this, "Please install a File Manager.", 
                Toast.LENGTH_SHORT).show();
    }
}

You would then listen for the selected file's Uri in onActivityResult() like so:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    switch (requestCode) {
        case FILE_SELECT_CODE:
        if (resultCode == RESULT_OK) {
            // Get the Uri of the selected file 
            Uri uri = data.getData();
            Log.d(TAG, "File Uri: " + uri.toString());
            // Get the path
            String path = FileUtils.getPath(this, uri);
            Log.d(TAG, "File Path: " + path);
            // Get the file instance
            // File file = new File(path);
            // Initiate the upload
        }
        break;
    }
    super.onActivityResult(requestCode, resultCode, data);
}

The getPath() method in my FileUtils.java is:

public static String getPath(Context context, Uri uri) throws URISyntaxException {
    if ("content".equalsIgnoreCase(uri.getScheme())) {
        String[] projection = { "_data" };
        Cursor cursor = null;

        try {
            cursor = context.getContentResolver().query(uri, projection, null, null, null);
            int column_index = cursor.getColumnIndexOrThrow("_data");
            if (cursor.moveToFirst()) {
                return cursor.getString(column_index);
            }
        } catch (Exception e) {
            // Eat it
        }
    }
    else if ("file".equalsIgnoreCase(uri.getScheme())) {
        return uri.getPath();
    }

    return null;
} 

What does it mean to write to stdout in C?

stdout stands for standard output stream and it is a stream which is available to your program by the operating system itself. It is already available to your program from the beginning together with stdin and stderr.

What they point to (or from) can be anything, actually the stream just provides your program an object that can be used as an interface to send or retrieve data. By default it is usually the terminal but it can be redirected wherever you want: a file, to a pipe goint to another process and so on.

Android sample bluetooth code to send a simple string via bluetooth

private OutputStream outputStream;
private InputStream inStream;

private void init() throws IOException {
    BluetoothAdapter blueAdapter = BluetoothAdapter.getDefaultAdapter();
    if (blueAdapter != null) {
        if (blueAdapter.isEnabled()) {
            Set<BluetoothDevice> bondedDevices = blueAdapter.getBondedDevices();

            if(bondedDevices.size() > 0) {
                Object[] devices = (Object []) bondedDevices.toArray();
                BluetoothDevice device = (BluetoothDevice) devices[position];
                ParcelUuid[] uuids = device.getUuids();
                BluetoothSocket socket = device.createRfcommSocketToServiceRecord(uuids[0].getUuid());
                socket.connect();
                outputStream = socket.getOutputStream();
                inStream = socket.getInputStream();
            }

            Log.e("error", "No appropriate paired devices.");
        } else {
            Log.e("error", "Bluetooth is disabled.");
        }
    }
}

public void write(String s) throws IOException {
    outputStream.write(s.getBytes());
}

public void run() {
    final int BUFFER_SIZE = 1024;
    byte[] buffer = new byte[BUFFER_SIZE];
    int bytes = 0;
    int b = BUFFER_SIZE;

    while (true) {
        try {
            bytes = inStream.read(buffer, bytes, BUFFER_SIZE - bytes);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Is there a way to return a list of all the image file names from a folder using only Javascript?

IMHO, Edizkan Adil Ata's idea is actually the most proper way. It extracts the URLs of anchor tags and puts them in a different tag. And if you don't want to let the anchors being seen by the page visitor then just .hide() them all with JQuery or display: none; in CSS.

Also you can perform prefetching, like this:

<link rel="prefetch" href="imagefolder/clouds.jpg" />

That way you don't have to hide it and still can extract the path to the image.

Add one day to date in javascript

If you don't mind using a library, DateJS (https://github.com/abritinthebay/datejs/) would make this fairly easy. You would probably be better off with one of the answers using vanilla JavaScript however, unless you're going to take advantage of some other DateJS features like parsing of unusually-formatted dates.

If you're using DateJS a line like this should do the trick:

Date.parse(startdate).add(1).days();

You could also use MomentJS which has similar features (http://momentjs.com/), however I'm not as familiar with it.

BehaviorSubject vs Observable?

BehaviorSubject

The BehaviorSubject builds on top of the same functionality as our ReplaySubject, subject like, hot, and replays previous value.

The BehaviorSubject adds one more piece of functionality in that you can give the BehaviorSubject an initial value. Let’s go ahead and take a look at that code

import { ReplaySubject } from 'rxjs';

const behaviorSubject = new BehaviorSubject(
  'hello initial value from BehaviorSubject'
);

behaviorSubject.subscribe(v => console.log(v));

behaviorSubject.next('hello again from BehaviorSubject');

Observables

To get started we are going to look at the minimal API to create a regular Observable. There are a couple of ways to create an Observable. The way we will create our Observable is by instantiating the class. Other operators can simplify this, but we will want to compare the instantiation step to our different Observable types

import { Observable } from 'rxjs';

const observable = new Observable(observer => {
  setTimeout(() => observer.next('hello from Observable!'), 1000);
});

observable.subscribe(v => console.log(v));

error: could not create '/usr/local/lib/python2.7/dist-packages/virtualenv_support': Permission denied

It's because the virtual environment viarable has not been installed.

Try this:

sudo pip install virtualenv
virtualenv --python python3 env
source env/bin/activate
pip install <Package>

or

sudo pip3 install virtualenv
virtualenv --python python3 env
source env/bin/activate
pip3 install <Package>

WaitAll vs WhenAll

Task.WaitAll blocks the current thread until everything has completed.

Task.WhenAll returns a task which represents the action of waiting until everything has completed.

That means that from an async method, you can use:

await Task.WhenAll(tasks);

... which means your method will continue when everything's completed, but you won't tie up a thread to just hang around until that time.

Reading settings from app.config or web.config in .NET

For a sample app.config file like below:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <add key="countoffiles" value="7" />
    <add key="logfilelocation" value="abc.txt" />
  </appSettings>
</configuration>

You read the above application settings using the code shown below:

using System.Configuration;

You may also need to also add a reference to System.Configuration in your project if there isn't one already. You can then access the values like so:

string configvalue1 = ConfigurationManager.AppSettings["countoffiles"];
string configvalue2 = ConfigurationManager.AppSettings["logfilelocation"];

How to check if directory exist using C++ and winAPI

Here is a simple function which does exactly this :

#include <windows.h>
#include <string>

bool dirExists(const std::string& dirName_in)
{
  DWORD ftyp = GetFileAttributesA(dirName_in.c_str());
  if (ftyp == INVALID_FILE_ATTRIBUTES)
    return false;  //something is wrong with your path!

  if (ftyp & FILE_ATTRIBUTE_DIRECTORY)
    return true;   // this is a directory!

  return false;    // this is not a directory!
}

Fastest way to check a string is alphanumeric in Java

Use String.matches(), like:

String myString = "qwerty123456";
System.out.println(myString.matches("[A-Za-z0-9]+"));

That may not be the absolute "fastest" possible approach. But in general there's not much point in trying to compete with the people who write the language's "standard library" in terms of performance.

Python Set Comprehension

You can generate pairs like this:

{(x, x + 2) for x in r if x + 2 in r}

Then all that is left to do is to get a condition to make them prime, which you have already done in the first example.

A different way of doing it: (Although slower for large sets of primes)

{(x, y) for x in r for y in r if x + 2 == y}

How to fix .pch file missing on build?

I know this topic is very old, but I was dealing with this in VS2015 recently and what helped was to deleted the build folders and re-build it. This may have happen due to trying to close the program or a program halting/freezing VS while building.

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

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

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

SQL FIDDLE

Advantages:

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

Limitations:

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

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

To overcame the limitation we can use the following ref.

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

Again i hope this solution can help some-one.

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

Is #pragma once a safe include guard?

I wish #pragma once (or something like it) had been in the standard. Include guards aren't a real big deal (but they do seem to be a little difficult to explain to people learning the language), but it seems like a minor annoyance that could have been avoided.

In fact, since 99.98% of the time, the #pragma once behavior is the desired behavior, it would have been nice if preventing multiple inclusion of a header was automatically handled by the compiler, with a #pragma or something to allow double including.

But we have what we have (except that you might not have #pragma once).

ReDim Preserve to a Multi-Dimensional Array in Visual Basic 6

I haven't tested every single one of these answers but you don't need to use complicated functions to accomplish this. It's so much easier than that! My code below will work in any office VBA application (Word, Access, Excel, Outlook, etc.) and is very simple. Hope this helps:

''Dimension 2 Arrays
Dim InnerArray(1 To 3) As Variant ''The inner is for storing each column value of the current row
Dim OuterArray() As Variant ''The outer is for storing each row in
Dim i As Byte

    i = 1
    Do While i <= 5

        ''Enlarging our outer array to store a/another row
        ReDim Preserve OuterArray(1 To i)

        ''Loading the current row column data in
        InnerArray(1) = "My First Column in Row " & i
        InnerArray(2) = "My Second Column in Row " & i
        InnerArray(3) = "My Third Column in Row " & i

        ''Loading the entire row into our array
        OuterArray(i) = InnerArray

        i = i + 1
    Loop

    ''Example print out of the array to the Intermediate Window
    Debug.Print OuterArray(1)(1)
    Debug.Print OuterArray(1)(2)
    Debug.Print OuterArray(2)(1)
    Debug.Print OuterArray(2)(2)

Pass variables from servlet to jsp

When using setAttribute and getRequestDispatcher on doGet, make sure that you are accessing your pages with the urlPatterns ("/login" for example) defined for your servlet. If you do it with "/login.jsp" your doGet won't get called so none of your attributes will be available.

Regex - how to match everything except a particular pattern

You could use a look-ahead assertion:

(?!999)\d{3}

This example matches three digits other than 999.


But if you happen not to have a regular expression implementation with this feature (see Comparison of Regular Expression Flavors), you probably have to build a regular expression with the basic features on your own.

A compatible regular expression with basic syntax only would be:

[0-8]\d\d|\d[0-8]\d|\d\d[0-8]

This does also match any three digits sequence that is not 999.

Best TCP port number range for internal applications

I decided to download the assigned port numbers from IANA, filter out the used ports, and sort each "Unassigned" range in order of most ports available, descending. This did not work, since the csv file has ranges marked as "Unassigned" that overlap other port number reservations. I manually expanded the ranges of assigned port numbers, leaving me with a list of all assigned port numbers. I then sorted that list and generated my own list of unassigned ranges.

Since this stackoverflow.com page ranked very high in my search about the topic, I figured I'd post the largest ranges here for anyone else who is interested. These are for both TCP and UDP where the number of ports in the range is at least 500.

Total   Start   End
829     29170   29998
815     38866   39680
710     41798   42507
681     43442   44122
661     46337   46997
643     35358   36000
609     36866   37474
596     38204   38799
592     33657   34248
571     30261   30831
563     41231   41793
542     21011   21552
528     28590   29117
521     14415   14935
510     26490   26999

Source (via the CSV download button):

http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml

Connect to SQL Server 2012 Database with C# (Visual Studio 2012)

Replacing server=localhost with server=.\SQLEXPRESS might do the job.

Trigger validation of all fields in Angular Form submit

To validate all fields of my form when I want, I do a validation on each field of $$controls like this :

angular.forEach($scope.myform.$$controls, function (field) {
    field.$validate();
});

What are the various "Build action" settings in Visual Studio project properties and what do they do?

VS2010 has a property for 'Build Action', and also for 'Copy to Output Directory'. So an action of 'None' will still copy over to the build directory if the copy property is set to 'Copy if Newer' or 'Copy Always'.

So a Build Action of 'Content' should be reserved to indicate content you will access via 'Application.GetContentStream'

I used the 'Build Action' setting of 'None' and the 'Copy to Output Direcotry' setting of 'Copy if Newer' for some externally linked .config includes.

G.

How to cast an Object to an int

@Deprecated
public static int toInt(Object obj)
{
    if (obj instanceof String)
    {
         return Integer.parseInt((String) obj);
    } else if (obj instanceof Number)
    {
         return ((Number) obj).intValue();
    } else
    {
         String toString = obj.toString();
         if (toString.matches("-?\d+"))
         {
              return Integer.parseInt(toString);
         }
         throw new IllegalArgumentException("This Object doesn't represent an int");
    }
}

As you can see, this isn't a very efficient way of doing it. You simply have to be sure of what kind of object you have. Then convert it to an int the right way.

HtmlSpecialChars equivalent in Javascript?

Chances are you don't need such a function. Since your code is already in the browser*, you can access the DOM directly instead of generating and encoding HTML that will have to be decoded backwards by the browser to be actually used.

Use innerText property to insert plain text into the DOM safely and much faster than using any of the presented escape functions. Even faster than assigning a static preencoded string to innerHTML.

Use classList to edit classes, dataset to set data- attributes and setAttribute for others.

All of these will handle escaping for you. More precisely, no escaping is needed and no encoding will be performed underneath**, since you are working around HTML, the textual representation of DOM.

_x000D_
_x000D_
// use existing element_x000D_
var author = 'John "Superman" Doe <[email protected]>';_x000D_
var el = document.getElementById('first');_x000D_
el.dataset.author = author;_x000D_
el.textContent = 'Author: '+author;_x000D_
_x000D_
// or create a new element_x000D_
var a = document.createElement('a');_x000D_
a.classList.add('important');_x000D_
a.href = '/search?q=term+"exact"&n=50';_x000D_
a.textContent = 'Search for "exact" term';_x000D_
document.body.appendChild(a);_x000D_
_x000D_
// actual HTML code_x000D_
console.log(el.outerHTML);_x000D_
console.log(a.outerHTML);
_x000D_
.important { color: red; }
_x000D_
<div id="first"></div>
_x000D_
_x000D_
_x000D_

* This answer is not intended for server-side JavaScript users (Node.js, etc.)

** Unless you explicitly convert it to actual HTML afterwards. E.g. by accessing innerHTML - this is what happens when you run $('<div/>').text(value).html(); suggested in other answers. So if your final goal is to insert some data into the document, by doing it this way you'll be doing the work twice. Also you can see that in the resulting HTML not everything is encoded, only the minimum that is needed for it to be valid. It is done context-dependently, that's why this jQuery method doesn't encode quotes and therefore should not be used as a general purpose escaper. Quotes escaping is needed when you're constructing HTML as a string with untrusted or quote-containing data at the place of an attribute's value. If you use the DOM API, you don't have to care about escaping at all.

ImportError: Cannot import name X

Not specifically for this asker, but this same error will show if the class name in your import doesn't match the definition in the file you're importing from.

Which maven dependencies to include for spring 3.0?

You can add spring-context dependency for spring jars. You will get the following jars along with it.

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>5.0.5.RELEASE</version>
</dependency>

Spring context dependencies

if you also want web components, you can use spring-webmvc dependency.

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.0.5.RELEASE</version>
</dependency>

Spring webmvc dependencies

You can use whatever version of that you want. I have used 5.0.5.RELEASE here.

How to set web.config file to show full error message

This can also help you by showing full details of the error on a client's browser.

<system.web>
    <customErrors mode="Off"/>
</system.web>
<system.webServer>
    <httpErrors errorMode="Detailed" />
</system.webServer>

Android - Activity vs FragmentActivity?

If you use the Eclipse "New Android Project" wizard in a recent ADT bundle, you'll automatically get tabs implemented as a Fragments. This makes the conversion of your application to the tablet format much easier in the future.

For simple single screen layouts you may still use Activity.

jQuery replace one class with another

To do this efficiently using jQuery, you can chain it like so:

$('.theClassThatsThereNow').addClass('newClassWithYourStyles').removeClass('theClassThatsTherenow');

For simplicities sake, you can also do it step by step like so (note assigning the jquery object to a var isnt necessary, but it feels safer in case you accidentally remove the class you're targeting before adding the new class and are directly accessing the dom node via its jquery selector like $('.theClassThatsThereNow')):

var el = $('.theClassThatsThereNow');
el.addClass('newClassWithYourStyles');
el.removeClass('theClassThatsThereNow');

Also (since there is a js tag), if you wanted to do it in vanilla js:

For modern browsers (See this to see which browsers I'm calling modern)

(assuming one element with class theClassThatsThereNow)

var el = document.querySelector('.theClassThatsThereNow');
el.classList.remove('theClassThatsThereNow');
el.classList.add('newClassWithYourStyleRules');

Or older browsers:

var el = document.getElementsByClassName('theClassThatsThereNow');
el.className = el.className.replace(/\s*theClassThatsThereNow\s*/, ' newClassWithYourStyleRules ');

How to make inactive content inside a div?

Without using an overlay, you can use pointer-events: none on the div in CSS, but this does not work in IE or Opera.

div.disabled
{
  pointer-events: none;

  /* for "disabled" effect */
  opacity: 0.5;
  background: #CCC;
}

Reference

Laravel migration: unique key is too long, even if specified

I'd like to point that something that i missed ...

I'm new at Laravel, and i didn't copy the "use Illuminate....." because i really didn'at paid atention, because right above the function boot you alread have a use Statement.

Hope that helps anyone

**use Illuminate\Support\Facades\Schema;**

public function boot()
{
    Schema::defaultStringLength(191);
}

List of All Locales and Their Short Codes?

If you are using php-intl to localize your application, you probably want to use ResourceBundle::getLocales() instead of static list that you maintain yourself. It can also give you locales for particular language.

<?php
print_r(ResourceBundle::getLocales(''));

/* Output might show
  * Array
  * (
  *    [0] => af
  *    [1] => af_NA
  *    [2] => af_ZA
  *    [3] => am
  *    [4] => am_ET
  *    [5] => ar
  *    [6] => ar_AE
  *    [7] => ar_BH
  *    [8] => ar_DZ
  *    [9] => ar_EG
  *    [10] => ar_IQ
  *  ...
  */
?>

How to convert a huge list-of-vector to a matrix more efficiently?

You can also use,

output <- as.matrix(as.data.frame(z))

The memory usage is very similar to

output <- matrix(unlist(z), ncol = 10, byrow = TRUE)

Which can be verified, with mem_changed() from library(pryr).

How to Read from a Text File, Character by Character in C++

@cnicutar and @Pete Becker have already pointed out the possibility of using noskipws/unsetting skipws to read a character at a time without skipping over white space characters in the input.

Another possibility would be to use an istreambuf_iterator to read the data. Along with this, I'd generally use a standard algorithm like std::transform to do the reading and processing.

Just for example, let's assume we wanted to do a Caesar-like cipher, copying from standard input to standard output, but adding 3 to every upper-case character, so A would become D, B could become E, etc. (and at the end, it would wrap around so XYZ converted to ABC.

If we were going to do that in C, we'd typically use a loop something like this:

int ch;
while (EOF != (ch = getchar())) {
    if (isupper(ch)) 
        ch = ((ch - 'A') +3) % 26 + 'A';
    putchar(ch);
}

To do the same thing in C++, I'd probably write the code more like this:

std::transform(std::istreambuf_iterator<char>(std::cin),
               std::istreambuf_iterator<char>(),
               std::ostreambuf_iterator<char>(std::cout),
               [](int ch) { return isupper(ch) ? ((ch - 'A') + 3) % 26 + 'A' : ch;});

Doing the job this way, you receive the consecutive characters as the values of the parameter passed to (in this case) the lambda function (though you could use an explicit functor instead of a lambda if you preferred).

How do I set the selenium webdriver get timeout?

I had the same problem and thanks to this forum and some other found the answer. Initially I also thought of separate thread but it complicates the code a bit. So I tried to find an answer that aligns with my principle "elegance and simplicity".

Please have a look at such forum: https://sqa.stackexchange.com/questions/2606/what-is-seleniums-default-timeout-for-page-loading

#

SOLUTION: In the code, before the line with 'get' method you can use for example:

driver.manage().timeouts().pageLoadTimeout(10, TimeUnit.SECONDS);
#

One thing is that it throws timeoutException so you have to encapsulate it in the try catch block or wrap in some method.

I haven't found the getter for the pageLoadTimeout so I don't know what is the default value, but probably very high since my script was frozen for many hours and nothing moved forward.

#

NOTICE: 'pageLoadTimeout' is NOT implemented for Chrome driver and thus causes exception. I saw by users comments that there are plans to make it.

How can I refresh a page with jQuery?

Three approaches with different cache-related behaviours:

  • location.reload(true)

    In browsers that implement the forcedReload parameter of location.reload(), reloads by fetching a fresh copy of the page and all of its resources (scripts, stylesheets, images, etc.). Will not serve any resources from the cache - gets fresh copies from the server without sending any if-modified-since or if-none-match headers in the request.

    Equivalent to the user doing a "hard reload" in browsers where that's possible.

    Note that passing true to location.reload() is supported in Firefox (see MDN) and Internet Explorer (see MSDN) but is not supported universally and is not part of the W3 HTML 5 spec, nor the W3 draft HTML 5.1 spec, nor the WHATWG HTML Living Standard.

    In unsupporting browsers, like Google Chrome, location.reload(true) behaves the same as location.reload().

  • location.reload() or location.reload(false)

    Reloads the page, fetching a fresh, non-cached copy of the page HTML itself, and performing RFC 7234 revalidation requests for any resources (like scripts) that the browser has cached, even if they are fresh are RFC 7234 permits the browser to serve them without revalidation.

    Exactly how the browser should utilise its cache when performing a location.reload() call isn't specified or documented as far as I can tell; I determined the behaviour above by experimentation.

    This is equivalent to the user simply pressing the "refresh" button in their browser.

  • location = location (or infinitely many other possible techniques that involve assigning to location or to its properties)

    Only works if the page's URL doesn't contain a fragid/hashbang!

    Reloads the page without refetching or revalidating any fresh resources from the cache. If the page's HTML itself is fresh, this will reload the page without performing any HTTP requests at all.

    This is equivalent (from a caching perspective) to the user opening the page in a new tab.

    However, if the page's URL contains a hash, this will have no effect.

    Again, the caching behaviour here is unspecified as far as I know; I determined it by testing.

So, in summary, you want to use:

  • location = location for maximum use of the cache, as long as the page doesn't have a hash in its URL, in which case this won't work
  • location.reload(true) to fetch new copies of all resources without revalidating (although it's not universally supported and will behave no differently to location.reload() in some browsers, like Chrome)
  • location.reload() to faithfully reproduce the effect of the user clicking the 'refresh' button.

AngularJS ngClass conditional

Angular JS provide this functionality in ng-class Directive. In which you can put condition and also assign conditional class. You can achieve this in two different ways.

Type 1

<div ng-class="{0:'one', 1:'two',2:'three'}[status]"></div>

In this code class will be apply according to value of status value

if status value is 0 then apply class one

if status value is 1 then apply class two

if status value is 2 then apply class three


Type 2

<div ng-class="{1:'test_yes', 0:'test_no'}[status]"></div>

In which class will be apply by value of status

if status value is 1 or true then it will add class test_yes

if status value is 0 or false then it will add class test_no

Comparing HTTP and FTP for transferring files

Both of them uses TCP as a transport protocol, but HTTP uses a persistent connection, which makes the performance of the TCP better.

Try/catch does not seem to have an effect

In my case, it was because I was only catching specific types of exceptions:

try
  {
    get-item -Force -LiteralPath $Path -ErrorAction Stop

    #if file exists
    if ($Path -like '\\*') {$fileType = 'n'}  #Network
    elseif ($Path -like '?:\*') {$fileType = 'l'} #Local
    else {$fileType = 'u'} #Unknown File Type

  }
catch [System.UnauthorizedAccessException] {$fileType = 'i'} #Inaccessible
catch [System.Management.Automation.ItemNotFoundException]{$fileType = 'x'} #Doesn't Exist

Added these to handle additional the exception causing the terminating error, as well as unexpected exceptions

catch [System.Management.Automation.DriveNotFoundException]{$fileType = 'x'} #Doesn't Exist
catch {$fileType='u'} #Unknown

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.

Select Row number in postgres

SELECT tab.*,
    row_number() OVER () as rnum
  FROM tab;

Here's the relevant section in the docs.

P.S. This, in fact, fully matches the answer in the referenced question.

Consider marking event handler as 'passive' to make the page more responsive

For those receiving this warning for the first time, it is due to a bleeding edge feature called Passive Event Listeners that has been implemented in browsers fairly recently (summer 2016). From https://github.com/WICG/EventListenerOptions/blob/gh-pages/explainer.md:

Passive event listeners are a new feature in the DOM spec that enable developers to opt-in to better scroll performance by eliminating the need for scrolling to block on touch and wheel event listeners. Developers can annotate touch and wheel listeners with {passive: true} to indicate that they will never invoke preventDefault. This feature shipped in Chrome 51, Firefox 49 and landed in WebKit. For full official explanation read more here.

See also: What are passive event listeners?

You may have to wait for your .js library to implement support.

If you are handling events indirectly via a JavaScript library, you may be at the mercy of that particular library's support for the feature. As of December 2019, it does not look like any of the major libraries have implemented support. Some examples:

How to embed a PDF viewer in a page?

pdf2htmlEX by coolwanglu is probably the best solution out there to convert a pdf file into html. You could do a simple convert and then embed the html page as an iframe or something similar.

how to make UITextView height dynamic according to text length?

In Storyboard / Interface Builder simply disable scrolling in the Attribute inspector.

In code textField.scrollEnabled = false should do the trick.

download and install visual studio 2008

Try this one: http://www.asp.net/downloads/essential This has web developer and VS2008 express

How can I change the class of an element with jQuery>

I like to write a small plugin to make things cleaner:

$.fn.setClass = function(classes) {
    this.attr('class', classes);
    return this;
};

That way you can simply do

$('button').setClass('btn btn-primary');

How to Implement DOM Data Binding in JavaScript

Changing an element's value can trigger a DOM event. Listeners that respond to events can be used to implement data binding in JavaScript.

For example:

function bindValues(id1, id2) {
  const e1 = document.getElementById(id1);
  const e2 = document.getElementById(id2);
  e1.addEventListener('input', function(event) {
    e2.value = event.target.value;
  });
  e2.addEventListener('input', function(event) {
    e1.value = event.target.value;
  });
}

Here is code and a demo that shows how DOM elements can be bound with each other or with a JavaScript object.

React Hook "useState" is called in function "app" which is neither a React function component or a custom React Hook function

Try to capitalize 'app' like

const App = props => {...}

export default App;

In React, components need to be capitalized, and custom hooks need to start with use.

Not equal <> != operator on NULL

<> is Standard SQL-92; != is its equivalent. Both evaluate for values, which NULL is not -- NULL is a placeholder to say there is the absence of a value.

Which is why you can only use IS NULL/IS NOT NULL as predicates for such situations.

This behavior is not specific to SQL Server. All standards-compliant SQL dialects work the same way.

Note: To compare if your value is not null, you use IS NOT NULL, while to compare with not null value, you use <> 'YOUR_VALUE'. I can't say if my value equals or not equals to NULL, but I can say if my value is NULL or NOT NULL. I can compare if my value is something other than NULL.

Getting value of HTML Checkbox from onclick/onchange events

The short answer:

Use the click event, which won't fire until after the value has been updated, and fires when you want it to:

<label><input type='checkbox' onclick='handleClick(this);'>Checkbox</label>

function handleClick(cb) {
  display("Clicked, new value = " + cb.checked);
}

Live example | Source

The longer answer:

The change event handler isn't called until the checked state has been updated (live example | source), but because (as Tim Büthe points out in the comments) IE doesn't fire the change event until the checkbox loses focus, you don't get the notification proactively. Worse, with IE if you click a label for the checkbox (rather than the checkbox itself) to update it, you can get the impression that you're getting the old value (try it with IE here by clicking the label: live example | source). This is because if the checkbox has focus, clicking the label takes the focus away from it, firing the change event with the old value, and then the click happens setting the new value and setting focus back on the checkbox. Very confusing.

But you can avoid all of that unpleasantness if you use click instead.

I've used DOM0 handlers (onxyz attributes) because that's what you asked about, but for the record, I would generally recommend hooking up handlers in code (DOM2's addEventListener, or attachEvent in older versions of IE) rather than using onxyz attributes. That lets you attach multiple handlers to the same element and lets you avoid making all of your handlers global functions.


An earlier version of this answer used this code for handleClick:

function handleClick(cb) {
  setTimeout(function() {
    display("Clicked, new value = " + cb.checked);
  }, 0);
}

The goal seemed to be to allow the click to complete before looking at the value. As far as I'm aware, there's no reason to do that, and I have no idea why I did. The value is changed before the click handler is called. In fact, the spec is quite clear about that. The version without setTimeout works perfectly well in every browser I've tried (even IE6). I can only assume I was thinking about some other platform where the change isn't done until after the event. In any case, no reason to do that with HTML checkboxes.

sorting and paging with gridview asp.net

<asp:GridView 
    ID="GridView1" runat="server" AutoGenerateColumns="false" AllowSorting="True" onsorting="GridView1_Sorting" EnableViewState="true"> 
    <Columns>
        <asp:BoundField DataField="bookid" HeaderText="BOOK ID"SortExpression="bookid"  />
        <asp:BoundField DataField="bookname" HeaderText="BOOK NAME" />
        <asp:BoundField DataField="writer" HeaderText="WRITER" />
        <asp:BoundField DataField="totalbook" HeaderText="TOTALBOOK" SortExpression="totalbook"  />
        <asp:BoundField DataField="availablebook" HeaderText="AVAILABLE BOOK" />
    </Columns>
</asp:GridView>

Code behind:

protected void Page_Load(object sender, EventArgs e) {
        if (!IsPostBack) {
            string query = "SELECT * FROM book";
            DataTable DT = new DataTable();
            SqlDataAdapter DA = new SqlDataAdapter(query, sqlCon);
            DA.Fill(DT);

            GridView1.DataSource = DT;
            GridView1.DataBind();
        }
    }

    protected void GridView1_Sorting(object sender, GridViewSortEventArgs e) {

        string query = "SELECT * FROM book";
        DataTable DT = new DataTable();
        SqlDataAdapter DA = new SqlDataAdapter(query, sqlCon);
        DA.Fill(DT);

        GridView1.DataSource = DT;
        GridView1.DataBind();

        if (DT != null) {
            DataView dataView = new DataView(DT);
            dataView.Sort = e.SortExpression + " " + ConvertSortDirectionToSql(e.SortDirection);

            GridView1.DataSource = dataView;
            GridView1.DataBind();
        }
    }

    private string GridViewSortDirection {
        get { return ViewState["SortDirection"] as string ?? "DESC"; }
        set { ViewState["SortDirection"] = value; }
    }

    private string ConvertSortDirectionToSql(SortDirection sortDirection) {
        switch (GridViewSortDirection) {
            case "ASC":
                GridViewSortDirection = "DESC";
                break;

            case "DESC":
                GridViewSortDirection = "ASC";
                break;
        }

        return GridViewSortDirection;
    }
}

Confirmation before closing of tab/browser

Simply

function goodbye(e) {
        if(!e) e = window.event;
        //e.cancelBubble is supported by IE - this will kill the bubbling process.
        e.cancelBubble = true;
        e.returnValue = 'You sure you want to leave?'; //This is displayed on the dialog

        //e.stopPropagation works in Firefox.
        if (e.stopPropagation) {
            e.stopPropagation();
            e.preventDefault();
        }
    }
window.onbeforeunload=goodbye;

How to set the thumbnail image on HTML5 video?

If you want a video first frame as a thumbnail, than you can use

Add #t=0.1 to your video source, like below

<video width="320" height="240" controls>
  <source src="video.mp4#t=0.1" type="video/mp4">
</video>

NOTE: make sure about your video type(ex: mp4, ogg, webm etc)