Convert String (UTF-16) to UTF-8 in C#

A string in C# is always UTF-16, there is no way to "convert" it. The encoding is irrelevant as long as you manipulate the string in memory, it only matters if you write the string to a stream (file, memory stream, network stream...).

If you want to write the string to a XML file, just specify the encoding when you create the XmlWriter

Sending HTML mail using a shell script

The question asked specifically on shell script and the question tag mentioning only about sendmail package. So, if someone is looking for this, here is the simple script with sendmail usage that is working for me on CentOS 8:

#!/bin/sh
TOEMAIL="[email protected]"
REPORT_FILE_HTML="$REPORT_FILE.html"
echo "Subject: EMAIL SUBJECT" >> "${REPORT_FILE_HTML}"
echo "MIME-Version: 1.0" >> "${REPORT_FILE_HTML}"
echo "Content-Type: text/html" >> "${REPORT_FILE_HTML}"
echo "<html>" >> "${REPORT_FILE_HTML}"
echo "<head>" >> "${REPORT_FILE_HTML}"
echo "<title>Best practice to include title to view online email</title>" >> "${REPORT_FILE_HTML}"
echo "</head>" >> "${REPORT_FILE_HTML}"
echo "<body>" >> "${REPORT_FILE_HTML}"
echo "<p>Hello there, you can put email html body here</p>" >> "${REPORT_FILE_HTML}"
echo "</body>" >> "${REPORT_FILE_HTML}"
echo "</html>" >> "${REPORT_FILE_HTML}"

sendmail $TOEMAIL < $REPORT_FILE_HTML

No log4j2 configuration file found. Using default configuration: logging only errors to the console

Tested with: log4j-ap 2.13.2, log4j-core 2.13.2.

Keep XML file directly under below folder structure. src/main/java
In the POM:

    <build>   
 <resources>       
             <resource>
                <filtering>false</filtering>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>             
            </resource>
 </resources>  
</build>

Clean and build.

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

This is a nice trick to reopen the current file with a different encoding:

:e ++enc=cp1250 %:p

Useful when you have to work with legacy encodings. The supported encodings are listed in a table under encoding-values (see help encoding-values). Similar thing also works for ++ff, so that you can reopen file with Windows/Unix line ends if you get it wrong for the first time (see help ff).

Django - limiting query results

Looks like the solution in the question doesn't work with Django 1.7 anymore and raises an error: "Cannot reorder a query once a slice has been taken"

According to the documentation https://docs.djangoproject.com/en/dev/topics/db/queries/#limiting-querysets forcing the “step” parameter of Python slice syntax evaluates the Query. It works this way:

Model.objects.all().order_by('-id')[:10:1]

Still I wonder if the limit is executed in SQL or Python slices the whole result array returned. There is no good to retrieve huge lists to application memory.

Merge development branch with master

Personally, my approach is similar to yours, with a few more branches and some squashing of commits when they go back to master.

One of my co-workers doesn't like having to switch branches so much and stays on the development branch with something similar to the following all executed from the development branch.

git fetch origin master

git merge master

git push origin development:master

The first line makes sure he has any upstream commits that have been made to master since the last time updated his local repository.

The second pulls those changes (if any) from master into development

The third pushes the development branch (now fully merged with master) up to origin/master.

I may have his basic workflow a little wrong, but that is the main gist of it.

Error: "Input is not proper UTF-8, indicate encoding !" using PHP's simplexml_load_string

We recently ran into a similar issue and was unable to find anything obvious as the cause. There turned out to be a control character in our string but when we outputted that string to the browser that character was not visible unless we copied the text into an IDE.

We managed to solve our problem thanks to this post and this:

preg_replace('/[\x00-\x1F\x7F]/', '', $input);

How do I concatenate two strings in C?

#include <string.h>
#include <stdio.h>
int main()
{
   int a,l;
   char str[50],str1[50],str3[100];
   printf("\nEnter a string: ");
   scanf("%s",str);
   str3[0]='\0';
   printf("\nEnter the string which you want to concat with string one: ");
   scanf("%s",str1);
   strcat(str3,str);
   strcat(str3,str1);
   printf("\nThe string is %s\n",str3);
}

How can I tell if a VARCHAR variable contains a substring?

CONTAINS is for a Full Text Indexed field - if not, then use LIKE

ImportError: No module named psycopg2

sudo pip install psycopg2-binary

npm ERR! code UNABLE_TO_GET_ISSUER_CERT_LOCALLY

what may be happening is your company decrypts certain traffic and re-encrypts it with their certificate (which you probably already have in your keychain or trusted root certificates)

if you're using node 7 or later I've found this fix to be compatible with node and node-gyp (for Windows you'll need to do this differently, but you basically just need to add this environment variable):

export NODE_EXTRA_CA_CERTS="absolute_path_to_your_certificates.pem" (in Windows you may need to remove the quotes - see comments)

the pem file can have multiple certificates: https://nodejs.org/api/cli.html#cli_node_extra_ca_certs_file

make sure your certificates are in proper pem format (you need real line breaks not literal \n)

I couldn't seem to get it to work with relative paths (. or ~)

This fix basically tells npm and node-gyp to use the check against the regular CAs, but also allow this certificate when it comes across it

Ideally you would be able to use your system's trusted certificates, but unfortunately this is not the case.

npm WARN ... requires a peer of ... but none is installed. You must install peer dependencies yourself

In my case following commands worked for me:

sudo npm cache clean --force
sudo npm install -g npm


sudo apt install libssl1.0-dev
sudo apt install nodejs-dev
sudo apt install node-gyp
sudo apt install npm

After that if you are facing "Cannot find module 'bcrypt' then for that you can resolve this one with below commands:

npm install node-gyp -g
npm install bcrypt -g
npm install bcrypt --save

Hope it will work for you as well.

Using Pip to install packages to Anaconda Environment

For others who run into this situation, I found this to be the most straightforward solution:

Run conda create -n venv_name and source activate venv_name, where venv_name is the name of your virtual environment.
Run conda install pip. This will install pip to your venv directory.
Find your anaconda directory, and find the actual venv folder. It should be somewhere like /anaconda/envs/venv_name/.
Install new packages by doing /anaconda/envs/venv_name/bin/pip install package_name.

This should now successfully install packages using that virtual environment's pip!

JavaScript: set dropdown selected item based on option text

This works in latest Chrome, FireFox and Edge, but not IE11:

document.evaluate('//option[text()="Yahoo"]', document).iterateNext().selected = 'selected';

And if you want to ignore spaces around the title:

document.evaluate('//option[normalize-space(text())="Yahoo"]', document).iterateNext().selected = 'selected'

Use a JSON array with objects with javascript

By 'JSON array containing objects' I guess you mean a string containing JSON?

If so you can use the safe var myArray = JSON.parse(myJSON) method (either native or included using JSON2), or the usafe var myArray = eval("(" + myJSON + ")"). eval should normally be avoided, but if you are certain that the content is safe, then there is no problem.

After that you just iterate over the array as normal.

for (var i = 0; i < myArray.length; i++) {
    alert(myArray[i].Title);
}

How to downgrade to older version of Gradle

got it resolved:

uninstall the entire android studio

uninstalling android with the following commands

rm -Rf /Applications/Android\ Studio.app  
rm -Rf ~/Library/Preferences/AndroidStudio*  
rm -Rf ~/Library/Preferences/com.google.android.*  
rm -Rf ~/Library/Preferences/com.android.*  
rm -Rf ~/Library/Application\ Support/AndroidStudio*  
rm -Rf ~/Library/Logs/AndroidStudio*  
rm -Rf ~/Library/Caches/AndroidStudio*  
rm -Rf ~/.AndroidStudio*  
rm -Rf ~/.gradle  
rm -Rf ~/.android  
rm -Rf ~/Library/Android*  
rm -Rf /usr/local/var/lib/android-sdk/  
rm -Rf /Users/<username>/.tooling/gradle

Remove your project and clone it again and then goto Gradle Scripts and open gradle-wrapper.properties and change the below url which ever version you need

distributionUrl=https\://services.gradle.org/distributions/gradle-4.2-all.zip

ClassNotFoundException: org.slf4j.LoggerFactory

I got this problem too and I fixed it in this way. I was trying to run mapreduce job locally through Eclipse, after set the configurations, I met this error (in Linux, Virtual Box) To solve it,

right click on the project you want to run,
go "Properties"->"Java Build Path"->"Add External Jars",
then go to file:/usr/lib/Hadoop/client-0.20, choose the three jars named started by "slf4j".

Then you'll be able to run the job locally. Hope my experience will help someone.

How to view hierarchical package structure in Eclipse package explorer

Here is representation of screen eclipse to make hierarachical.

How can I view the Git history in Visual Studio Code?

You won't need a plugin to see commit history with Visual Studio Code 1.42 or more.

Timeline view

In this milestone, we've made progress on the new Timeline view, and have an early preview to share.
This is a unified view for visualizing time-series events (e.g. commits, saves, test runs, etc.) for a resource (file, folder, etc.).

To enable the Timeline view, you must be using the Insiders Edition (VSCode 1.44 March 2020) and then add the following setting:

"timeline.showView": true

How to check a Long for null in java

As mentioned already primitives can not be set to the Object type null.

What I do in such cases is just to use -1 or Long.MIN_VALUE.

Sometimes adding a WCF Service Reference generates an empty reference.cs

Generally I find that it's a code-gen issue and most of the time it's because I've got a type name conflict it couldn't resolve.

If you right-click on your service reference and click configure and uncheck "Reuse Types in Referenced Assemblies" it'll likely resolve the issue.

If you were using some aspect of this feature, you might need to make sure your names are cleaned up.

How do you fix a MySQL "Incorrect key file" error when you can't repair the table?

Apply proper charset and collation to database, table and columns/fields.

I creates database and table structure using sql queries from one server to another. it creates database structure as follows:

database with charset of "utf8", collation of "utf8_general_ci"
tables with charset of "utf8" and collation of "utf8_bin".
table columns / fields have charset "utf8" and collation of "utf8_bin".

I change collation of table and column to utf8_general_ci, and it resolves the error.

Sass .scss: Nesting and multiple classes?

Christoph's answer is perfect. Sometimes however you may want to go more classes up than one. In this case you could try the @at-root and #{} css features which would enable two root classes to sit next to each other using &.

This wouldn't work (due to the nothing before & rule):

_x000D_

container {_x000D_
    background:red;_x000D_
    color:white;_x000D_
    _x000D_
    .desc& {_x000D_
      background: blue;_x000D_
    }_x000D_
_x000D_
    .hello {_x000D_
        padding-left:50px;_x000D_
    }_x000D_
}

_x000D_

But this would (using @at-root plus #{&}):

_x000D_

container {_x000D_
    background:red;_x000D_
    color:white;_x000D_
    _x000D_
    @at-root .desc#{&} {_x000D_
      background: blue;_x000D_
    }_x000D_
_x000D_
    .hello {_x000D_
        padding-left:50px;_x000D_
    }_x000D_
}

_x000D_

Web-scraping JavaScript page with Python

Selenium is the best for scraping JS and Ajax content.

Check this article for extracting data from the web using Python

$ pip install selenium

Then download Chrome webdriver.

from selenium import webdriver

browser = webdriver.Chrome()

browser.get("https://www.python.org/")

nav = browser.find_element_by_id("mainnav")

print(nav.text)

Easy, right?

How do I put a clear button inside my HTML text input box like the iPhone does?

Maybe this simple solution can help:

_x000D_

<input type="text" id="myInput" value="No War"/><button onclick="document.getElementById('myInput').value = ''" title="Clear">X</button></input>

_x000D_

GIT commit as different user without email / or only email

Open Git Bash.

Set a Git username:

$ git config --global user.name "name family" Confirm that you have set the Git username correctly:

$ git config --global user.name

name family

Set a Git email:

$ git config --global user.email [email protected] Confirm that you have set the Git email correctly:

$ git config --global user.email

[email protected]

Angular cli generate a service and include the provider in one step

slight change in syntax from the accepted answer for Angular 5 and angular-cli 1.7.0

ng g service backendApi --module=app.module

How can INSERT INTO a table 300 times within a loop in SQL?

In ssms we can use GO to execute same statement

Edit This mean if you put

 some query

 GO n

Some query will be executed n times

No Title Bar Android Theme

if you want the original style of your Ui to remain and the title bar to be removed with no effect on that, you have to remove the title bar in your activity rather than the manifest. leave the original theme style that you had in the manifest and in each activity that you want no title bar use this.requestWindowFeature(Window.FEATURE_NO_TITLE); in the oncreate() method before setcontentview() like this:

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.activity_signup);
    ...
}

Apply CSS rules to a nested class inside a div

You use

#main_text .title {
  /* Properties */
}

If you just put a space between the selectors, styles will apply to all children (and children of children) of the first. So in this case, any child element of #main_text with the class name title. If you use > instead of a space, it will only select the direct child of the element, and not children of children, e.g.:

#main_text > .title {
  /* Properties */
}

Either will work in this case, but the first is more typically used.

How do I use reflection to call a generic method?

Inspired by Enigmativity's answer - let's assume you have two (or more) classes, like

public class Bar { }
public class Square { }

and you want to call the method Foo<T> with Bar and Square, which is declared as

public class myClass
{
    public void Foo<T>(T item)
    {
        Console.WriteLine(typeof(T).Name);
    }
}

Then you can implement an Extension method like:

public static class Extension
{
    public static void InvokeFoo<T>(this T t)
    {
        var fooMethod = typeof(myClass).GetMethod("Foo");
        var tType = typeof(T);
        var fooTMethod = fooMethod.MakeGenericMethod(new[] { tType });
        fooTMethod.Invoke(new myClass(), new object[] { t });
    }
}

With this, you can simply invoke Foo like:

var objSquare = new Square();
objSquare.InvokeFoo();

var objBar = new Bar();
objBar.InvokeFoo();

which works for every class. In this case, it will output:

Square
Bar

How can I make content appear beneath a fixed DIV element?

Wrap the menu contents with another div:

<div id="floatingMenu">
    <div>
        <a href="http://www.google.com">Test 1</a>
        <a href="http://www.google.com">Test 2</a>
        <a href="http://www.google.com">Test 3</a>
    </div>
</div>

And the CSS:

#floatingMenu {
    clear: both;
    position: fixed;
    width: 100%;
    height: 30px;
    background-color: #78AB46;
    top: 5px;
}

#floatingMenu > div {
    margin: auto;
    text-align: center;
}

And about your page below the menu, you can give it a padding-top as well:

#content {
    padding-top: 35px; /* top 5px plus height 30px */
}

How to compare two maps by their values

public boolean equalMaps(Map<?, ?> map1, Map<?, ?>map2) {

    if (map1==null || map2==null || map1.size() != map2.size()) {
        return false;
    }

    for (Object key: map1.keySet()) {
        if (!map1.get(key).equals(map2.get(key))) {
            return false;
        }
    }
    return true;
}

Experimental decorators warning in TypeScript compilation

This answer is intended for people who are using a Javascript project and not a Typescript one. Instead of a tsconfig.json file you may use a jsconfig.json file.

In the particular case of having the decorators warning you wan write inside the file:

{
    "compilerOptions": {
        "experimentalDecorators": true
    }
}

Fort the buggy behaviors asked, it's always better to specify the "include" in the config file, and restart the editor. E.g.

{
    "compilerOptions": {
        "target": "ES6",
        "experimentalDecorators": true
    },
    "include": [
        "app/**/*"
    ],
    "exclude": [
        "node_modules"
    ]
}

Use :hover to modify the css of another class?

It's not possible in CSS at the moment, unless you want to select a child or sibling element (trivial and described in other answers here).

For all other cases you'll need JavaScript. jQuery and frameworks like Angular can tackle this problem with relative ease.

[Edit]

With the new CSS (4) selector :has(), you'll be able to target parent elements/classes, making a CSS-Only solution viable in the near future!

Delete worksheet in Excel using VBA

Consider:

Sub SheetKiller()
    Dim s As Worksheet, t As String
    Dim i As Long, K As Long
    K = Sheets.Count

    For i = K To 1 Step -1
        t = Sheets(i).Name
        If t = "ID Sheet" Or t = "Summary" Then
            Application.DisplayAlerts = False
                Sheets(i).Delete
            Application.DisplayAlerts = True
        End If
    Next i
End Sub

NOTE:

Because we are deleting, we run the loop backwards.

Is there a GUI design app for the Tkinter / grid geometry?

Apart from the options already given in other answers, there's a current more active, recent and open-source project called pygubu.

This is the first description by the author taken from the github repository:

Pygubu is a RAD tool to enable quick & easy development of user interfaces for the python tkinter module.

The user interfaces designed are saved as XML, and by using the pygubu builder these can be loaded by applications dynamically as needed. Pygubu is inspired by Glade.

Pygubu hello world program is an introductory video explaining how to create a first project using Pygubu.

The following in an image of interface of the last version of pygubu designer on a OS X Yosemite 10.10.2:

enter image description here

I would definitely give it a try, and contribute to its development.

Linker command failed with exit code 1 - duplicate symbol __TMRbBp

I had similar issues with Version 9.2 (9C40b), the solution is

0) Close Xcode
1) Open project folder in terminal
2) pod update
3) open .
4) open project by clicking Project.xcworkspace

C++ performance vs. Java/C#

Go read about HP Labs' Dynamo, an interpreter for PA-8000 that runs on PA-8000, and often runs programs faster than they do natively. Then it won't seem at all surprising!

Don't think of it as an "intermediate step" -- running a program involves lots of other steps already, in any language.

It often comes down to:

programs have hot-spots, so even if you're slower running 95% of the body of code you have to run, you can still be performance-competitive if you're faster at the hot 5%
a HLL knows more about your intent than a LLL like C/C++, and so can generate more optimized code (OCaml has even more, and in practice is often even faster)
a JIT compiler has a lot of information that a static compiler doesn't (like, the actual data you happen to have this time)
a JIT compiler can do optimizations at run-time that traditional linkers aren't really allowed to do (like reordering branches so the common case is flat, or inlining library calls)

All in all, C/C++ are pretty lousy languages for performance: there's relatively little information about your data types, no information about your data, and no dynamic runtime to allow much in the way of run-time optimization.

What is the difference between T(n) and O(n)?

Short explanation:

If an algorithm is of T(g(n)), it means that the running time of the algorithm as n (input size) gets larger is proportional to g(n).

If an algorithm is of O(g(n)), it means that the running time of the algorithm as n gets larger is at most proportional to g(n).

Normally, even when people talk about O(g(n)) they actually mean T(g(n)) but technically, there is a difference.

More technically:

O(n) represents upper bound. T(n) means tight bound. O(n) represents lower bound.

f(x) = T(g(x)) iff f(x) = O(g(x)) and f(x) = O(g(x))

Basically when we say an algorithm is of O(n), it's also O(n²), O(n^1000000), O(2ⁿ), ... but a T(n) algorithm is not T(n²).

In fact, since f(n) = T(g(n)) means for sufficiently large values of n, f(n) can be bound within c₁g(n) and c₂g(n) for some values of c₁ and c₂, i.e. the growth rate of f is asymptotically equal to g: g can be a lower bound and and an upper bound of f. This directly implies f can be a lower bound and an upper bound of g as well. Consequently,

f(x) = T(g(x)) iff g(x) = T(f(x))

Similarly, to show f(n) = T(g(n)), it's enough to show g is an upper bound of f (i.e. f(n) = O(g(n))) and f is a lower bound of g (i.e. f(n) = O(g(n)) which is the exact same thing as g(n) = O(f(n))). Concisely,

f(x) = T(g(x)) iff f(x) = O(g(x)) and g(x) = O(f(x))

There are also little-oh and little-omega (?) notations representing loose upper and loose lower bounds of a function.

To summarize:

f(x) = O(g(x)) (big-oh) means that the growth rate of f(x) is asymptotically less than or equal to to the growth rate of g(x).

f(x) = O(g(x)) (big-omega) means that the growth rate of f(x) is asymptotically greater than or equal to the growth rate of g(x)

f(x) = o(g(x)) (little-oh) means that the growth rate of f(x) is asymptotically less than the growth rate of g(x).

f(x) = ?(g(x)) (little-omega) means that the growth rate of f(x) is asymptotically greater than the growth rate of g(x)

f(x) = T(g(x)) (theta) means that the growth rate of f(x) is asymptotically equal to the growth rate of g(x)

For a more detailed discussion, you can read the definition on Wikipedia or consult a classic textbook like Introduction to Algorithms by Cormen et al.

Sleep for milliseconds

From C++14 using std and also its numeric literals:

#include <chrono>
#include <thread>

using namespace std::chrono;

std::this_thread::sleep_for(123ms);

How to convert string representation of list to a list?

Inspired from some of the answers above that work with base python packages I compared the performance of a few (using Python 3.7.3):

Method 1: ast

import ast
list(map(str.strip, ast.literal_eval(u'[ "A","B","C" , " D"]')))
# ['A', 'B', 'C', 'D']

import timeit
timeit.timeit(stmt="list(map(str.strip, ast.literal_eval(u'[ \"A\",\"B\",\"C\" , \" D\"]')))", setup='import ast', number=100000)
# 1.292875313000195

Method 2: json

import json
list(map(str.strip, json.loads(u'[ "A","B","C" , " D"]')))
# ['A', 'B', 'C', 'D']

import timeit
timeit.timeit(stmt="list(map(str.strip, json.loads(u'[ \"A\",\"B\",\"C\" , \" D\"]')))", setup='import json', number=100000)
# 0.27833264000014424

Method 3: no import

list(map(str.strip, u'[ "A","B","C" , " D"]'.strip('][').replace('"', '').split(',')))
# ['A', 'B', 'C', 'D']

import timeit
timeit.timeit(stmt="list(map(str.strip, u'[ \"A\",\"B\",\"C\" , \" D\"]'.strip('][').replace('\"', '').split(',')))", number=100000)
# 0.12935059100027502

I was disappointed to see what I considered the method with the worst readability was the method with the best performance... there are tradeoffs to consider when going with the most readable option... for the type of workloads I use python for I usually value readability over a slightly more performant option, but as usual it depends.

Contain form within a bootstrap popover?

like this Working demo http://jsfiddle.net/7e2XU/21/show/# * Update: http://jsfiddle.net/kz5kjmbt/

 <div class="container">
    <div class="row" style="padding-top: 240px;"> <a href="#" class="btn btn-large btn-primary" rel="popover" data-content='
<form id="mainForm" name="mainForm" method="post" action="">
    <p>
        <label>Name :</label>
        <input type="text" id="txtName" name="txtName" />
    </p>
    <p>
        <label>Address 1 :</label>
        <input type="text" id="txtAddress" name="txtAddress" />
    </p>
    <p>
        <label>City :</label>
        <input type="text" id="txtCity" name="txtCity" />
    </p>
    <p>
        <input type="submit" name="Submit" value="Submit" />
    </p>
</form>
 data-placement="top" data-original-title="Fill in form">Open form</a>

    </div>
</div>

JavaScript code:

    $('a[rel=popover]').popover({
      html: 'true',
      placement: 'right'
    })

ScreenShot

working updated fiddle screenshot

Can I run HTML files directly from GitHub, instead of just viewing their source?

There is a new tool called GitHub HTML Preview, which does exactly what you want. Just prepend http://htmlpreview.github.com/? to the URL of any HTML file, e.g. http://htmlpreview.github.com/?https://github.com/twbs/bootstrap/blob/gh-pages/2.3.2/index.html

Note: This tool is actually a github.io page and is not affiliated with github as a company.

Should I add the Visual Studio .suo and .user files to source control?

You cannot source-control the .user files, because that's user specific. It contains the name of remote machine and other user-dependent things. It's a vcproj related file.

The .suo file is a sln related file and it contains the "solution user options" (startup project(s), windows position (what's docked and where, what's floating), etc.)

It's a binary file, and I don't know if it contains something "user related".

In our company we do not take those files under source control.

jQuery validate: How to add a rule for regular expression validation?

I got it to work like this:

$.validator.addMethod(
    "regex",
    function(value, element, regexp) {
        return this.optional(element) || regexp.test(value);
    },
    "Please check your input."
);


$(function () {
    $('#uiEmailAdress').focus();
    $('#NewsletterForm').validate({
        rules: {
            uiEmailAdress:{
                required: true,
                email: true,
                minlength: 5
            },
            uiConfirmEmailAdress:{
                required: true,
                email: true,
                equalTo: '#uiEmailAdress'
            },
            DDLanguage:{
                required: true
            },
            Testveld:{
                required: true,
                regex: /^[0-9]{3}$/
            }
        },
        messages: {
            uiEmailAdress:{
                required: 'Verplicht veld',
                email: 'Ongeldig emailadres',
                minlength: 'Minimum 5 charaters vereist'
            },
            uiConfirmEmailAdress:{
                required: 'Verplicht veld',
                email: 'Ongeldig emailadres',
                equalTo: 'Veld is niet gelijk aan E-mailadres'
            },
            DDLanguage:{
                required: 'Verplicht veld'
            },
            Testveld:{
                required: 'Verplicht veld',
                regex: '_REGEX'
            }
        }
    });
});

Make sure that the regex is between / :-)

How do I target only Internet Explorer 10 for certain situations like Internet Explorer-specific CSS or Internet Explorer-specific JavaScript code?

Both solutions posted here (with slight modifications) work:

<!--[if !IE]><!--><script>if(/*@cc_on!@*/false){document.documentElement.className='ie10';}</script><!--<![endif]-->

<script>if(Function('/*@cc_on return 10===document.documentMode@*/')()){document.documentElement.className='ie10';}</script>

You include either of the above lines inside of head tag of your html page before your css link. And then in css file you specify your styles having "ie10" class as a parent:

.ie10 .myclass1 { }

And voilà! - other browsers stay intact. And you don't need jQuery. You can see the example how I implemented it here: http://kardash.net.

Fill remaining vertical space - only CSS

If you can add an extra couple of divs so your html looks like this:

<div id="wrapper">
    <div id="first" class="row">
        <div class="cell"></div>
    </div>
    <div id="second" class="row">
        <div class="cell"></div>
    </div>
</div>

You can make use of the display:table properties:

#wrapper
{
   width:300px;
   height:100%;
   display:table;
}

.row 
{
   display:table-row;
}

.cell 
{
   display:table-cell;
}

#first .cell
{
   height:200px;
   background-color:#F5DEB3;
}

#second .cell
{
   background-color:#9ACD32;
}

Example

maven "cannot find symbol" message unhelpful

This is a bug in the Maven compiler plugin, related to JDK7 I think. Works fine with JDK6.

calling a java servlet from javascript

var button = document.getElementById("<<button-id>>");
button.addEventListener("click", function() {
  window.location.href= "<<full-servlet-path>>" (eg. http://localhost:8086/xyz/servlet)
});

How do I check if PHP is connected to a database already?

before... (I mean somewhere in some other file you're not sure you've included)

$db = mysql_connect()

later...

if (is_resource($db)) {
// connected
} else {
$db = mysql_connect();
}

How to check if a network port is open on linux?

If you only care about the local machine, you can rely on the psutil package. You can either:

Check all ports used by a specific pid:

proc = psutil.Process(pid)
print proc.connections()

Check all ports used on the local machine:
```
print psutil.net_connections()
```

It works on Windows too.

https://github.com/giampaolo/psutil

How to check if a file exists before creating a new file

C++17, cross-platform: Using std::filesystem::exists and std::filesystem::is_regular_file.

#include <filesystem> // C++17
#include <fstream>
#include <iostream>
namespace fs = std::filesystem;

bool CreateFile(const fs::path& filePath, const std::string& content)
{
    try
    {
        if (fs::exists(filePath))
        {
            std::cout << filePath << " already exists.";
            return false;
        }
        if (!fs::is_regular_file(filePath))
        {
            std::cout << filePath << " is not a regular file.";
            return false;
        }
    }
    catch (std::exception& e)
    {
        std::cerr << __func__ << ": An error occurred: " << e.what();
        return false;
    }
    std::ofstream file(filePath);
    file << content;
    return true;
}
int main()
{
    if (CreateFile("path/to/the/file.ext", "Content of the file"))
    {
        // Your business logic.
    }
}

git ignore all files of a certain type, except those in a specific subfolder

An optional prefix ! which negates the pattern; any matching file excluded by a previous pattern will become included again. If a negated pattern matches, this will override lower precedence patterns sources.

http://schacon.github.com/git/gitignore.html

*.json
!spec/*.json

mysqld_safe Directory '/var/run/mysqld' for UNIX socket file don't exists

Work for me in CentOS:

$ service mysql stop
$ mysqld --skip-grant-tables &
$ mysql -u root mysql

mysql> FLUSH PRIVILEGES;
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'new_password';

$ service mysql restart

getting exception "IllegalStateException: Can not perform this action after onSaveInstanceState"

I solved the issue with onconfigurationchanged. The trick is that according to android activity life cycle, when you explicitly called an intent(camera intent, or any other one); the activity is paused and onsavedInstance is called in that case. When rotating the device to a different position other than the one during which the activity was active; doing fragment operations such as fragment commit causes Illegal state exception. There are lots of complains about it. It's something about android activity lifecycle management and proper method calls. To solve it I did this: 1-Override the onsavedInstance method of your activity, and determine the current screen orientation(portrait or landscape) then set your screen orientation to it before your activity is paused. that way the activity you lock the screen rotation for your activity in case it has been rotated by another one. 2-then , override onresume method of activity, and set your orientation mode now to sensor so that after onsaved method is called it will call one more time onconfiguration to deal with the rotation properly.

You can copy/paste this code into your activity to deal with it:

@Override
protected void onSaveInstanceState(Bundle outState) {       
    super.onSaveInstanceState(outState);

    Toast.makeText(this, "Activity OnResume(): Lock Screen Orientation ", Toast.LENGTH_LONG).show();
    int orientation =this.getDisplayOrientation();
    //Lock the screen orientation to the current display orientation : Landscape or Potrait
    this.setRequestedOrientation(orientation);
}

//A method found in stackOverflow, don't remember the author, to determine the right screen orientation independently of the phone or tablet device 
public int getDisplayOrientation() {
    Display getOrient = getWindowManager().getDefaultDisplay();

    int orientation = getOrient.getOrientation();

    // Sometimes you may get undefined orientation Value is 0
    // simple logic solves the problem compare the screen
    // X,Y Co-ordinates and determine the Orientation in such cases
    if (orientation == Configuration.ORIENTATION_UNDEFINED) {
        Configuration config = getResources().getConfiguration();
        orientation = config.orientation;

        if (orientation == Configuration.ORIENTATION_UNDEFINED) {
        // if height and widht of screen are equal then
        // it is square orientation
            if (getOrient.getWidth() == getOrient.getHeight()) {
                orientation = Configuration.ORIENTATION_SQUARE;
            } else { //if widht is less than height than it is portrait
                if (getOrient.getWidth() < getOrient.getHeight()) {
                    orientation = Configuration.ORIENTATION_PORTRAIT;
                } else { // if it is not any of the above it will defineitly be landscape
                    orientation = Configuration.ORIENTATION_LANDSCAPE;
                }
            }
        }
    }
    return orientation; // return value 1 is portrait and 2 is Landscape Mode
}

@Override
public void onResume() {
    super.onResume();
    Toast.makeText(this, "Activity OnResume(): Unlock Screen Orientation ", Toast.LENGTH_LONG).show();
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR);
}

Formatting text in a TextBlock

This is my solution....

    <TextBlock TextWrapping="Wrap" Style="{DynamicResource InstructionStyle}"> 
        <Run Text="This wizard will take you through the purge process in the correct order." FontWeight="Bold"></Run>
        <LineBreak></LineBreak>
        <Run Text="To Begin, select" FontStyle="Italic"></Run>
        <Run x:Name="InstructionSection" Text="'REPLACED AT RUNTIME'" FontWeight="Bold"></Run>
        <Run Text="from the menu." FontStyle="Italic"></Run>
    </TextBlock>

I am learning... so if anyone has thaughts on the above solution please share! :)

ImportError: No module named PyQt4

You have to check which Python you are using. I had the same problem because the Python I was using was not the same one that brew was using. In your command line:

which python
output: /usr/bin/python
which brew
output: /usr/local/bin/brew //so they are different
cd /usr/local/lib/python2.7/site-packages
ls //you can see PyQt4 and sip are here
Now you need to add usr/local/lib/python2.7/site-packages to your python path.
open ~/.bash_profile //you will open your bash_profile file in your editor
Add 'export PYTHONPATH=/usr/local/lib/python2.7/site-packages:$PYTHONPATH' to your bash file and save it
Close your terminal and restart it to reload the shell
python
import PyQt4 // it is ok now

Simple PHP Pagination script

This is a mix of HTML and code but it's pretty basic, easy to understand and should be fairly simple to decouple to suit your needs I think.

try {

    // Find out how many items are in the table
    $total = $dbh->query('
        SELECT
            COUNT(*)
        FROM
            table
    ')->fetchColumn();

    // How many items to list per page
    $limit = 20;

    // How many pages will there be
    $pages = ceil($total / $limit);

    // What page are we currently on?
    $page = min($pages, filter_input(INPUT_GET, 'page', FILTER_VALIDATE_INT, array(
        'options' => array(
            'default'   => 1,
            'min_range' => 1,
        ),
    )));

    // Calculate the offset for the query
    $offset = ($page - 1)  * $limit;

    // Some information to display to the user
    $start = $offset + 1;
    $end = min(($offset + $limit), $total);

    // The "back" link
    $prevlink = ($page > 1) ? '<a href="?page=1" title="First page">&laquo;</a> <a href="?page=' . ($page - 1) . '" title="Previous page">&lsaquo;</a>' : '<span class="disabled">&laquo;</span> <span class="disabled">&lsaquo;</span>';

    // The "forward" link
    $nextlink = ($page < $pages) ? '<a href="?page=' . ($page + 1) . '" title="Next page">&rsaquo;</a> <a href="?page=' . $pages . '" title="Last page">&raquo;</a>' : '<span class="disabled">&rsaquo;</span> <span class="disabled">&raquo;</span>';

    // Display the paging information
    echo '<div id="paging"><p>', $prevlink, ' Page ', $page, ' of ', $pages, ' pages, displaying ', $start, '-', $end, ' of ', $total, ' results ', $nextlink, ' </p></div>';

    // Prepare the paged query
    $stmt = $dbh->prepare('
        SELECT
            *
        FROM
            table
        ORDER BY
            name
        LIMIT
            :limit
        OFFSET
            :offset
    ');

    // Bind the query params
    $stmt->bindParam(':limit', $limit, PDO::PARAM_INT);
    $stmt->bindParam(':offset', $offset, PDO::PARAM_INT);
    $stmt->execute();

    // Do we have any results?
    if ($stmt->rowCount() > 0) {
        // Define how we want to fetch the results
        $stmt->setFetchMode(PDO::FETCH_ASSOC);
        $iterator = new IteratorIterator($stmt);

        // Display the results
        foreach ($iterator as $row) {
            echo '<p>', $row['name'], '</p>';
        }

    } else {
        echo '<p>No results could be displayed.</p>';
    }

} catch (Exception $e) {
    echo '<p>', $e->getMessage(), '</p>';
}

Html.BeginForm and adding properties

You can also use the following syntax for the strongly typed version:

<% using (Html.BeginForm<SomeController>(x=> x.SomeAction(), 
          FormMethod.Post, 
          new { enctype = "multipart/form-data" })) 
   { %>

What are the most-used vim commands/keypresses?

I can't imagine everyone uses all 20 different keypresses to navigate text, 10 or so keys to start adding text, and 18 ways to visually select an inner block. Or do you!?

I do.

In theory, once I have that and start becoming as proficient in VIM as I am in Textmate, then I can start learning the thousands of other VIM commands that will make me more efficient.

That's the right way to do it. Start with basic commands and then pick up ones that improve your productivity. I like following this blog for tips on how to improve my productivity with vim.

What dependency is missing for org.springframework.web.bind.annotation.RequestMapping?

This solution WORKS , I had the same issue and after hours I came up to this:

(1) Go to your pom.xml

(2) Add this Dependency :

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>4.1.6.RELEASE</version>
    </dependency>

(3) Run your Project

Is there any quick way to get the last two characters in a string?

Use substring method like this::

str.substring(str.length()-2);

Installing tensorflow with anaconda in windows

I use windows 10, Anaconda and python 2. A combination of mentioned solutions worked for me:

Once you installed tensorflow using:

C:\Users\Laleh>conda create -n tensorflow python=3.5 # use your python version

C:\Users\Laleh>activate tensorflow

(tensorflow) C:\Users\Laleh>conda install -c conda-forge tensorflow

Then I realized tensorflow can not be imported in jupyter notebook, although it can work in commad windows. To solve this issue first I checked:

jupyter kernelspec list

I removeed the Jupyter kernelspec, useing:

jupyter kernelspec remove python2

Now, the jupyter kernelspec list is pointing to the correct kernel. Again, I activate tensorflow and installed notebook in its environment:

C:\Users\Laleh>activate tensorflow

(tensorflow)C:> conda install notebook

Also if you want to use other libraries such as matplotlib, they should be installed separately in tensorflow environment

(tensorflow)C:> conda install -c conda-forge matplotlib

Now everything works fine for me.

AsyncTask Android example

Sample Async Task with POST request:

List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("key1", "value1"));
params.add(new BasicNameValuePair("key1", "value2"));
new WEBSERVICEREQUESTOR(URL, params).execute();

class WEBSERVICEREQUESTOR extends AsyncTask<String, Integer, String>
{
    String URL;
    List<NameValuePair> parameters;

    private ProgressDialog pDialog;

    public WEBSERVICEREQUESTOR(String url, List<NameValuePair> params)
    {
        this.URL = url;
        this.parameters = params;
    }

    @Override
    protected void onPreExecute()
    {
        pDialog = new ProgressDialog(LoginActivity.this);
        pDialog.setMessage("Processing Request...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(false);
        pDialog.show();
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(String... params)
    {
        try
        {
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpEntity httpEntity = null;
            HttpResponse httpResponse = null;

            HttpPost httpPost = new HttpPost(URL);

            if (parameters != null)
            {
                httpPost.setEntity(new UrlEncodedFormEntity(parameters));
            }
            httpResponse = httpClient.execute(httpPost);

            httpEntity = httpResponse.getEntity();
            return EntityUtils.toString(httpEntity);

        }  catch (Exception e)
        {

        }
        return "";
    }

    @Override
    protected void onPostExecute(String result)
    {
        pDialog.dismiss();

        try
        {

        }
        catch (Exception e)
        {

        }
        super.onPostExecute(result);
    }
}

Iterate through the fields of a struct in Go

After you've retrieved the reflect.Value of the field by using Field(i) you can get a interface value from it by calling Interface(). Said interface value then represents the value of the field.

There is no function to convert the value of the field to a concrete type as there are, as you may know, no generics in go. Thus, there is no function with the signature GetValue() T with T being the type of that field (which changes of course, depending on the field).

The closest you can achieve in go is GetValue() interface{} and this is exactly what reflect.Value.Interface() offers.

The following code illustrates how to get the values of each exported field in a struct using reflection (play):

import (
    "fmt"
    "reflect"
)

func main() {
    x := struct{Foo string; Bar int }{"foo", 2}

    v := reflect.ValueOf(x)

    values := make([]interface{}, v.NumField())

    for i := 0; i < v.NumField(); i++ {
        values[i] = v.Field(i).Interface()
    }

    fmt.Println(values)
}

How best to read a File into List<string>

Why not use a generator instead?

private IEnumerable<string> ReadLogLines(string logPath) {
    using(StreamReader reader = File.OpenText(logPath)) {
        string line = "";
        while((line = reader.ReadLine()) != null) {
            yield return line;
        }
    }
}

Then you can use it like you would use the list:

var logFile = ReadLogLines(LOG_PATH);
foreach(var s in logFile) {
    // Do whatever you need
}

Of course, if you need to have a List<string>, then you will need to keep the entire file contents in memory. There's really no way around that.

How can I simulate a click to an anchor tag?

None of the above solutions address the generic intention of the original request. What if we don't know the id of the anchor? What if it doesn't have an id? What if it doesn't even have an href parameter (e.g. prev/next icon in a carousel)? What if we want to apply the action to multiple anchors with different models in an agnostic fashion? Here's an example that does something instead of a click, then later simulates the click (for any anchor or other tag):

var clicker = null;
$('a').click(function(e){ 
    clicker=$(this); // capture the clicked dom object
    /* ... do something ... */
    e.preventDefault(); // prevent original click action
});
clicker[0].click(); // this repeats the original click. [0] is necessary.

Java parsing XML document gives "Content not allowed in prolog." error

I think this is also a solution of this problem.

Change your document type from 'Encode in UTF-8' To 'Encode in UTF-8 without BOM'

I got resolved my problem by doing same changes.

jQuery: Setting select list 'selected' based on text, failing strangely

The following works for text entries both with and without spaces:

$("#mySelect1").find("option[text=" + text1 + "]").attr("selected", true);

Have Excel formulas that return 0, make the result blank

Just append an empty string to the end. It forces Excel to see it for what it is.

For example:

=IFERROR(1/1/INDEX(A,B,C) & "","")

CSS border less than 1px

The minimum width that your screen can display is 1 pixel. So its impossible to display less then 1px. 1 pixels can only have 1 color and cannot be split up.

Keyword not supported: "data source" initializing Entity Framework Context

Just use \" instead ", it should resolve the issue.

Warning :-Presenting view controllers on detached view controllers is discouraged

It depends if you want to show your alert or something similar in anywhere of kind UIViewController.

You can use this code example:

UIAlertController* alert = [UIAlertController alertControllerWithTitle:@"Alert" message:@"Example" preferredStyle:UIAlertControllerStyleAlert];

UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleDefault handler:nil];

[alert addAction:cancelAction];


[[[[[UIApplication sharedApplication] delegate] window] rootViewController] presentViewController:alert animated:true completion:nil];

Postgresql : Connection refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections

The error you quote has nothing to do with pg_hba.conf; it's failing to connect, not failing to authorize the connection.

Do what the error message says:

Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections

You haven't shown the command that produces the error. Assuming you're connecting on localhost port 5432 (the defaults for a standard PostgreSQL install), then either:

PostgreSQL isn't running
PostgreSQL isn't listening for TCP/IP connections (listen_addresses in postgresql.conf)
PostgreSQL is only listening on IPv4 (0.0.0.0 or 127.0.0.1) and you're connecting on IPv6 (::1) or vice versa. This seems to be an issue on some older Mac OS X versions that have weird IPv6 socket behaviour, and on some older Windows versions.
PostgreSQL is listening on a different port to the one you're connecting on
(unlikely) there's an iptables rule blocking loopback connections

(If you are not connecting on localhost, it may also be a network firewall that's blocking TCP/IP connections, but I'm guessing you're using the defaults since you didn't say).

So ... check those:

ps -f -u postgres should list postgres processes
sudo lsof -n -u postgres |grep LISTEN or sudo netstat -ltnp | grep postgres should show the TCP/IP addresses and ports PostgreSQL is listening on

BTW, I think you must be on an old version. On my 9.3 install, the error is rather more detailed:

$ psql -h localhost -p 12345
psql: could not connect to server: Connection refused
        Is the server running on host "localhost" (::1) and accepting
        TCP/IP connections on port 12345?

Query EC2 tags from within instance

For those crazy enough to use Fish shell on EC2, here's a handy snippet for your /home/ec2-user/.config/fish/config.fish. The hostdata command now will list all your tags as well as the public IP and hostname.

set -x INSTANCE_ID (wget -qO- http://instance-data/latest/meta-data/instance-id)
set -x REGION (wget -qO- http://instance-data/latest/meta-data/placement/availability-zone | sed 's/.$//')

function hostdata
    aws ec2 describe-tags --region $REGION --filter "Name=resource-id,Values=$INSTANCE_ID" --output=text | sed -r 's/TAGS\t(.*)\t.*\t.*\t(.*)/\1="\2"/'
    ec2-metadata | grep public-hostname
    ec2-metadata | grep public-ipv4
end

How to justify navbar-nav in Bootstrap 3

It turns out that there is a float: left property by default on all navbar-nav>li elements, which is why they were all scrunching up to the left. Once I added the code below, it made the navbar both centered and not scrunched up.

.navbar-nav>li {
        float: none;
}

Hope this helps someone else who's looking to center a navbar.

Android XXHDPI resources

A set of four generalized sizes: small, normal, large, and xlarge Note: Beginning with Android 3.2 (API level 13), these size groups are deprecated in favor of a new technique for managing screen sizes based on the available screen width. If you're developing for Android 3.2 and greater, see Declaring Tablet Layouts for Android 3.2 for more information.

A set of six generalized densities:

ldpi (low) ~120dpi

mdpi (medium) ~160dpi

hdpi (high) ~240dpi

xhdpi (extra-high) ~320dpi

xxhdpi (extra-extra-high) ~480dpi

xxxhdpi (extra-extra-extra-high) ~640dpi

From developer.android.com : http://developer.android.com/guide/practices/screens_support.html

Referencing Row Number in R

This is probably the simplest way:

data$rownumber = 1:dim(data)[1]

It's probably worth noting that if you want to select a row by its row index, you can do this with simple bracket notation

data[3,]

vs.

data[data$rownumber==3,]

So I'm not really sure what this new column accomplishes.

Recyclerview inside ScrollView not scrolling smoothly

Kotlin

Set isNestedScrollingEnabled to false for every RecyclerView that is under the scrolling view

val recyclerView = findViewById<RecyclerView>(R.id.recyclerView)
recyclerView.isNestedScrollingEnabled = false

Using XML Layout

<android.support.v7.widget.RecyclerView
    android:layout_marginTop="10dp"
    android:layout_marginBottom="10dp"
    android:id="@+id/friendsList"
    android:layout_width="match_parent"
    android:nestedScrollingEnabled="false"
    android:layout_height="wrap_content" />

What does the "yield" keyword do?

Here is an example in plain language. I will provide a correspondence between high-level human concepts to low-level Python concepts.

I want to operate on a sequence of numbers, but I don't want to bother my self with the creation of that sequence, I want only to focus on the operation I want to do. So, I do the following:

I call you and tell you that I want a sequence of numbers which is produced in a specific way, and I let you know what the algorithm is.
This step corresponds to defining the generator function, i.e. the function containing a yield.
Sometime later, I tell you, "OK, get ready to tell me the sequence of numbers".
This step corresponds to calling the generator function which returns a generator object. Note that you don't tell me any numbers yet; you just grab your paper and pencil.
I ask you, "tell me the next number", and you tell me the first number; after that, you wait for me to ask you for the next number. It's your job to remember where you were, what numbers you have already said, and what is the next number. I don't care about the details.
This step corresponds to calling .next() on the generator object.
… repeat previous step, until…
eventually, you might come to an end. You don't tell me a number; you just shout, "hold your horses! I'm done! No more numbers!"
This step corresponds to the generator object ending its job, and raising a StopIteration exception The generator function does not need to raise the exception. It's raised automatically when the function ends or issues a return.

This is what a generator does (a function that contains a yield); it starts executing, pauses whenever it does a yield, and when asked for a .next() value it continues from the point it was last. It fits perfectly by design with the iterator protocol of Python, which describes how to sequentially request values.

The most famous user of the iterator protocol is the for command in Python. So, whenever you do a:

for item in sequence:

it doesn't matter if sequence is a list, a string, a dictionary or a generator object like described above; the result is the same: you read items off a sequence one by one.

Note that defining a function which contains a yield keyword is not the only way to create a generator; it's just the easiest way to create one.

For more accurate information, read about iterator types, the yield statement and generators in the Python documentation.

Read data from SqlDataReader

I know this is kind of old but if you are reading the contents of a SqlDataReader into a class, then this will be very handy. the column names of reader and class should be same

public static List<T> Fill<T>(this SqlDataReader reader) where T : new()
        {
            List<T> res = new List<T>();
            while (reader.Read())
            {
                T t = new T();
                for (int inc = 0; inc < reader.FieldCount; inc++)
                {
                    Type type = t.GetType();
                    string name = reader.GetName(inc);
                    PropertyInfo prop = type.GetProperty(name);
                    if (prop != null)
                    {
                        if (name == prop.Name)
                        {
                            var value = reader.GetValue(inc);
                            if (value != DBNull.Value)
                            { 
                                prop.SetValue(t, Convert.ChangeType(value, prop.PropertyType), null);
                            }
                            //prop.SetValue(t, value, null);

                        }
                    }
                }
                res.Add(t);
            }
            reader.Close();

            return res;
        }

How to define custom sort function in javascript?

function msort(arr){
    for(var i =0;i<arr.length;i++){
        for(var j= i+1;j<arr.length;j++){
            if(arr[i]>arr[j]){
                var swap = arr[i];
                arr[i] = arr[j];
                arr[j] = swap;
            }
        }
    }
return arr;
}

PuTTY Connection Manager download?

You can get it at PuTTY: Extreme Makeover Using PuTTY Connection Manager.

Adding a rule in iptables in debian to open a new port

About your command line:

root@debian:/# sudo iptables -A INPUT -p tcp --dport 3306 --jump ACCEPT
root@debian:/# iptables-save

You are already authenticated as root so sudo is redundant there.
You are missing the -j or --jump just before the ACCEPT parameter (just tought that was a typo and you are inserting it correctly).

About yout question:

If you are inserting the iptables rule correctly as you pointed it in the question, maybe the issue is related to the hypervisor (virtual machine provider) you are using.

If you provide the hypervisor name (VirtualBox, VMWare?) I can further guide you on this but here are some suggestions you can try first:

check your vmachine network settings and:

if it is set to NAT, then you won't be able to connect from your base machine to the vmachine.
if it is set to Hosted, you have to configure first its network settings, it is usually to provide them an IP in the range 192.168.56.0/24, since is the default the hypervisors use for this.
if it is set to Bridge, same as Hosted but you can configure it whenever IP range makes sense for you configuration.

Hope this helps.

Best way to load module/class from lib folder in Rails 3?

In my case I was trying to simply load a file directly under the lib dir.

Within application.rb...

require '/lib/this_file.rb'

wasn't working, even in console and then when I tried

require './lib/this_file.rb'

and rails loads the file perfectly.

I'm still pretty noob and I'm not sure why this works but it works. If someone would like to explain it to me I'd appreciate it :D I hope this helps someone either way.

How to set menu to Toolbar in Android

just override onCreateOptionsMenu like this in your MainPage.java

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main_menu, menu);
    return true;
}

Gradle task - pass arguments to Java application

You can find the solution in Problems passing system properties and parameters when running Java class via Gradle . Both involve the use of the args property

Also you should read the difference between passing with -D or with -P that is explained in the Gradle documentation

Android basics: running code in the UI thread

None of those are precisely the same, though they will all have the same net effect.

The difference between the first and the second is that if you happen to be on the main application thread when executing the code, the first one (runOnUiThread()) will execute the Runnable immediately. The second one (post()) always puts the Runnable at the end of the event queue, even if you are already on the main application thread.

The third one, assuming you create and execute an instance of BackgroundTask, will waste a lot of time grabbing a thread out of the thread pool, to execute a default no-op doInBackground(), before eventually doing what amounts to a post(). This is by far the least efficient of the three. Use AsyncTask if you actually have work to do in a background thread, not just for the use of onPostExecute().

Reversing a linked list in Java, recursively

public class Singlelinkedlist {
  public static void main(String[] args) {
    Elem list  = new Elem();
    Reverse(list); //list is populate some  where or some how
  }

  //this  is the part you should be concerned with the function/Method has only 3 lines

  public static void Reverse(Elem e){
    if (e!=null)
      if(e.next !=null )
        Reverse(e.next);
    //System.out.println(e.data);
  }
}

class Elem {
  public Elem next;    // Link to next element in the list.
  public String data;  // Reference to the data.
}

Calculating Distance between two Latitude and Longitude GeoCoordinates

When CPU/math computing power is limited:

There are times (such as in my work) when computing power is scarce (e.g. no floating point processor, working with small microcontrollers) where some trig functions can take an exorbitant amount of CPU time (e.g. 3000+ clock cycles), so when I only need an approximation, especially if if the CPU must not be tied up for a long time, I use this to minimize CPU overhead:

/**------------------------------------------------------------------------
 * \brief  Great Circle distance approximation in km over short distances.
 *
 * Can be off by as much as 10%.
 *
 * approx_distance_in_mi = sqrt(x * x + y * y)
 *
 * where x = 69.1 * (lat2 - lat1)
 * and y = 69.1 * (lon2 - lon1) * cos(lat1/57.3)
 *//*----------------------------------------------------------------------*/
double    ApproximateDisatanceBetweenTwoLatLonsInKm(
                  double lat1, double lon1,
                  double lat2, double lon2
                  ) {
    double  ldRadians, ldCosR, x, y;

    ldRadians = (lat1 / 57.3) * 0.017453292519943295769236907684886;
    ldCosR = cos(ldRadians);
    x = 69.1 * (lat2 - lat1);
    y = 69.1 * (lon2 - lon1) * ldCosR;

    return sqrt(x * x + y * y) * 1.609344;  /* Converts mi to km. */
}

Credit goes to https://github.com/kristianmandrup/geo_vectors/blob/master/Distance%20calc%20notes.txt.

Pass a string parameter in an onclick function

You can use this:

'<input id="test" type="button" value="' + result.name + '" />'

$(document)..on('click', "#test", function () {
    alert($(this).val());
});

It worked for me.

Why am I getting a FileNotFoundError?

Difficult to give code examples in the comments.

To read the words in the file, you can read the contents of the file, which gets you a string - this is what you were doing before, with the read() method - and then use split() to get the individual words. Split breaks up a String on the delimiter provided, or on whitespace by default. For example,

"the quick brown fox".split()

produces

['the', 'quick', 'brown', 'fox']

Similarly,

fileScan.read().split()

will give you an array of Strings. Hope that helps!

How can strings be concatenated?

The easiest way would be

Section = 'Sec_' + Section

But for efficiency, see: https://waymoot.org/home/python_string/

From Now() to Current_timestamp in Postgresql

Here is what the MySQL docs say about NOW():

Returns the current date and time as a value in YYYY-MM-DD HH:MM:SS or YYYYMMDDHHMMSS.uuuuuu format, depending on whether the function is used in a string or numeric context. The value is expressed in the current time zone.

mysql> SELECT NOW();
        -> '2007-12-15 23:50:26'
mysql> SELECT NOW() + 0;
        -> 20071215235026.000000

Now, you can certainly reduce your smart date to something less...

SELECT (
 date_part('year', NOW())::text
 || date_part('month', NOW())::text
 || date_part('day', NOW())::text
 || date_part('hour', NOW())::text
 || date_part('minute', NOW())::text
 || date_part('second', NOW())::text
)::float8 + foo;

But, that would be a really bad idea, what you need to understand is that times and dates are not stupid unformated numbers, they are their own type with their own set of functions and operators

So the MySQL time essentially lets you treat NOW() as a dumber type, or it overrides + to make a presumption that I can't find in the MySQL docs. Eitherway, you probably want to look at the date and interval types in pg.

anaconda update all possible packages?

TL;DR: dependency conflicts: Updating one requires (by it's requirements) to downgrade another

You are right:

conda update --all

is actually the way to go¹. Conda always tries to upgrade the packages to the newest version in the series (say Python 2.x or 3.x).

Dependency conflicts

But it is possible that there are dependency conflicts (which prevent a further upgrade). Conda usually warns very explicitly if they occur.

e.g. X requires Y <5.0, so Y will never be >= 5.0

That's why you 'cannot' upgrade them all.

Resolving

To add: maybe it could work but a newer version of X working with Y > 5.0 is not available in conda. It is possible to install with pip, since more packages are available in pip. But be aware that pip also installs packages if dependency conflicts exist and that it usually breaks your conda environment in the sense that you cannot reliably install with conda anymore. If you do that, do it as a last resort and after all packages have been installed with conda. It's rather a hack.

A safe way you can try is to add conda-forge as a channel when upgrading (add -c conda-forge as a flag) or any other channel you find that contains your package if you really need this new version. This way conda does also search in this places for available packages.

Considering your update: You can upgrade them each separately, but doing so will not only include an upgrade but also a downgrade of another package as well. Say, to add to the example above:

X > 2.0 requires Y < 5.0, X < 2.0 requires Y > 5.0

So upgrading Y > 5.0 implies downgrading X to < 2.0 and vice versa.

(this is a pedagogical example, of course, but it's the same in reality, usually just with more complicated dependencies and sub-dependencies)

So you still cannot upgrade them all by doing the upgrades separately; the dependencies are just not satisfiable so earlier or later, an upgrade will downgrade an already upgraded package again. Or break the compatibility of the packages (which you usually don't want!), which is only possible by explicitly invoking an ignore-dependencies and force-command. But that is only to hack your way around issues, definitely not the normal-user case!

¹ If you actually want to update the packages of your installation, which you usually don't. The command run in the base environment will update the packages in this, but usually you should work with virtual environments (conda create -n myenv and then conda activate myenv). Executing conda update --all inside such an environment will update the packages inside this environment. However, since the base environment is also an environment, the answer applies to both cases in the same way.

Jquery : Refresh/Reload the page on clicking a button

You should use the location.reload(true), which will release the cache for that specific page and force the page to load as a NEW page.

The true parameter forces the page to release it's cache.

Run batch file from Java code

Your code is fine, but the problem is inside the batch file.

You have to show the content of the bat file, your problem is in the paths inside the bat file.

Manually raising (throwing) an exception in Python

For the common case where you need to throw an exception in response to some unexpected conditions, and that you never intend to catch, but simply to fail fast to enable you to debug from there if it ever happens — the most logical one seems to be AssertionError:

if 0 < distance <= RADIUS:
    #Do something.
elif RADIUS < distance:
    #Do something.
else:
    raise AssertionError("Unexpected value of 'distance'!", distance)

How to debug on a real device (using Eclipse/ADT)

Sometimes you need to reset ADB. To do that, in Eclipse, go:

Window>> Show View >> Android (Might be found in the "Other" option)>>Devices

in the device Tab, click the down arrow, and choose reset adb.

Using sed and grep/egrep to search and replace

I couldn't get any of the commands on this page to work for me: the sed solution added a newline to the end of all the files it processed, and the perl solution was unable to accept enough arguments from find. I found this solution which works perfectly:

find . -type f -name '*.[hm]' -print0 
    | xargs -0 perl -pi -e 's/search_regex/replacement_string/g'

This will recurse down the current directory tree and replace search_regex with replacement_string in any files ending in .h or .m.

I have also used rpl for this purpose in the past.

How to draw a rounded Rectangle on HTML Canvas?

The drawPolygon function below can be used to draw any polygon with rounded corners.

See it running here.

function drawPolygon(ctx, pts, radius) {
  if (radius > 0) {
    pts = getRoundedPoints(pts, radius);
  }
  var i, pt, len = pts.length;
  ctx.beginPath();
  for (i = 0; i < len; i++) {
    pt = pts[i];
    if (i == 0) {          
      ctx.moveTo(pt[0], pt[1]);
    } else {
      ctx.lineTo(pt[0], pt[1]);
    }
    if (radius > 0) {
      ctx.quadraticCurveTo(pt[2], pt[3], pt[4], pt[5]);
    }
  }
  ctx.closePath();
}

function getRoundedPoints(pts, radius) {
  var i1, i2, i3, p1, p2, p3, prevPt, nextPt,
      len = pts.length,
      res = new Array(len);
  for (i2 = 0; i2 < len; i2++) {
    i1 = i2-1;
    i3 = i2+1;
    if (i1 < 0) {
      i1 = len - 1;
    }
    if (i3 == len) {
      i3 = 0;
    }
    p1 = pts[i1];
    p2 = pts[i2];
    p3 = pts[i3];
    prevPt = getRoundedPoint(p1[0], p1[1], p2[0], p2[1], radius, false);
    nextPt = getRoundedPoint(p2[0], p2[1], p3[0], p3[1], radius, true);
    res[i2] = [prevPt[0], prevPt[1], p2[0], p2[1], nextPt[0], nextPt[1]];
  }
  return res;
};

function getRoundedPoint(x1, y1, x2, y2, radius, first) {
  var total = Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2)),
      idx = first ? radius / total : (total - radius) / total;
  return [x1 + (idx * (x2 - x1)), y1 + (idx * (y2 - y1))];
};

The function receives an array with the polygon points, like this:

var canvas = document.getElementById("cv");
var ctx = canvas.getContext("2d");
ctx.strokeStyle = "#000000";
ctx.lineWidth = 5;

drawPolygon(ctx, [[20,   20],
                  [120,  20],
                  [120, 120],
                  [ 20, 120]], 10);
ctx.stroke();

This is a port and a more generic version of a solution posted here.

How do I execute a program from Python? os.system fails due to spaces in path

For python >= 3.5 subprocess.run should be used in place of subprocess.call

https://docs.python.org/3/library/subprocess.html#older-high-level-api

import subprocess
subprocess.run(['notepad.exe', 'test.txt'])

How can I convert string to datetime with format specification in JavaScript?

time = "2017-01-18T17:02:09.000+05:30"

t = new Date(time)

hr = ("0" + t.getHours()).slice(-2);
min = ("0" + t.getMinutes()).slice(-2);
sec = ("0" + t.getSeconds()).slice(-2);

t.getFullYear()+"-"+t.getMonth()+1+"-"+t.getDate()+" "+hr+":"+min+":"+sec

Insert default value when parameter is null

The easiest way to do this is to modify the table declaration to be

CREATE TABLE Demo
(
    MyColumn VARCHAR(10) NOT NULL DEFAULT 'Me'
)

Now, in your stored procedure you can do something like.

CREATE PROCEDURE InsertDemo
    @MyColumn VARCHAR(10) = null
AS
INSERT INTO Demo (MyColumn) VALUES(@MyColumn)

However, this method ONLY works if you can't have a null, otherwise, your stored procedure would have to use a different form of insert to trigger a default.

mongodb count num of distinct values per field/key

To find distinct in field_1 in collection but we want some WHERE condition too than we can do like following :

db.your_collection_name.distinct('field_1', {WHERE condition here and it should return a document})

So, find number distinct names from a collection where age > 25 will be like :

db.your_collection_name.distinct('names', {'age': {"$gt": 25}})

Hope it helps!

How can I get this ASP.NET MVC SelectList to work?

It may be the case that you have some ambiguity in your ViewData:

Take a look Here

Stopping Docker containers by image name - Ubuntu

use: docker container stop $(docker container ls -q --filter ancestor=mongo)

    (base) :~ user$ docker ps
    CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                      NAMES
    d394144acf3a        mongo               "docker-entrypoint.s…"   15 seconds ago      Up 14 seconds       0.0.0.0:27017->27017/tcp   magical_nobel
    (base) :~ user$ docker container stop $(docker container ls -q --filter ancestor=mongo)
    d394144acf3a
    (base) :~ user$ docker ps
    CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
    (base) :~ user$

How to copy a huge table data into another table in SQL Server

select * into new_items from productDB.dbo.items

That pretty much is it. THis is the most efficient way to do it.

Verify host key with pysftp

Hi We sort of had the same problem if I understand you well. So check what pysftp version you're using. If it's the latest one which is 0.2.9 downgrade to 0.2.8. Check this out. https://github.com/Yenthe666/auto_backup/issues/47

How to pass credentials to httpwebrequest for accessing SharePoint Library

You could also use:

request.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials;

How to join multiple lines of file names into one with custom delimiter?

It looks like the answers already exist.

If you want a, b, c format, use ls -m ( Tulains Córdova’s answer)

Or if you want a b c format, use ls | xargs (simpified version of Chris J’s answer)

Or if you want any other delimiter like |, use ls | paste -sd'|' (application of Artem’s answer)

Understanding checked vs unchecked exceptions in Java

If anybody cares for yet another proof to dislike checked exceptions, see the first few paragraphs of the popular JSON library:

"Although this is a checked exception, it is rarely recoverable. Most callers should simply wrap this exception in an unchecked exception and rethrow: "

So why in the world would anyone make developers keep checking the exception, if we should "simply wrap it" instead? lol

http://developer.android.com/reference/org/json/JSONException.html

How to display loading message when an iFrame is loading?

Yes, you could use a transparent div positioned over the iframe area, with a loader gif as only background.

Then you can attach an onload event to the iframe:

 $(document).ready(function() {

   $("iframe#id").load(function() {
      $("#loader-id").hide();
   });
});

NGINX to reverse proxy websockets AND enable SSL (wss://)?

for .net core 2.0 Nginx with SSL

location / {
    # redirect all HTTP traffic to localhost:8080
    proxy_pass http://localhost:8080;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

    # WebSocket support
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $http_connection;
}

This worked for me

How to run vi on docker container?

Add the following line in your Dockerfile then rebuild the docker image.

RUN apt-get update && apt-get install -y vim

Removing a model in rails (reverse of "rails g model Title...")

For future questioners: If you can't drop the tables from the console, try to create a migration that drops the tables for you. You should create a migration and then in the file note tables you want dropped like this:

class DropTables < ActiveRecord::Migration
  def up
    drop_table :table_you_dont_want
  end

  def down
    raise ActiveRecord::IrreversibleMigration
  end
end

How to display a Windows Form in full screen on top of the taskbar?

I've tried so many solutions, some of them works on Windows XP and all of them did NOT work on Windows 7. After all I write a simple method to do so.

private void GoFullscreen(bool fullscreen)
    {
        if (fullscreen)
        {
            this.WindowState = FormWindowState.Normal;
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
            this.Bounds = Screen.PrimaryScreen.Bounds;
        }
        else
        {
            this.WindowState = FormWindowState.Maximized;
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.Sizable;
        }
    }

the order of code is important and will not work if you change the place of WindwosState and FormBorderStyle.

One of the advantages of this method is leaving the TOPMOST on false that allow other forms to come over the main form.

It absolutely solved my problem.

I am getting "java.lang.ClassNotFoundException: com.google.gson.Gson" error even though it is defined in my classpath

I ran into the above error when building and running inside Eclipse, where everything seemed to be fine, with the exception of this error. However, I discovered that a Maven build failed and that I needed to include Gson in my pom.xml. After fixing the pom.xml, everything fell into place.

html 5 audio tag width

You can use html and be a boss with simple things :

<embed src="music.mp3" width="3000" height="200" controls>

Avoid dropdown menu close on click inside

In .dropdown content put the .keep-open class on any label like so:

$('.dropdown').on('click', function (e) {
    var target = $(e.target);
    var dropdown = target.closest('.dropdown');
    if (target.hasClass('keep-open')) {
        $(dropdown).addClass('keep-open');
    } else {
        $(dropdown).removeClass('keep-open');
    }
});

$(document).on('hide.bs.dropdown', function (e) {
    var target = $(e.target);
    if ($(target).is('.keep-open')) {
        return false
    }
});

The previous cases avoided the events related to the container objects, now the container inherits the class keep-open and check before being closed.

Sass Nesting for :hover does not work

You can easily debug such things when you go through the generated CSS. In this case the pseudo-selector after conversion has to be attached to the class. Which is not the case. Use "&".

http://sass-lang.com/documentation/file.SASS_REFERENCE.html#parent-selector

.class {
    margin:20px;
    &:hover {
        color:yellow;
    }
}

Generating (pseudo)random alpha-numeric strings

I have made the following quick function just to play around with the range() function. It just might help someone sometime.

Function pseudostring($length = 50) {

    // Generate arrays with characters and numbers
    $lowerAlpha = range('a', 'z');
    $upperAlpha = range('A', 'Z');
    $numeric = range('0', '9');

    // Merge the arrays
    $workArray = array_merge($numeric, array_merge($lowerAlpha, $upperAlpha));
    $returnString = "";

    // Add random characters from the created array to a string
    for ($i = 0; $i < $length; $i++) {
        $character = $workArray[rand(0, 61)];
        $returnString .= $character;
    }

    return $returnString;
}

How to merge multiple dicts with same key or different key?

If you only have d1 and d2,

from collections import defaultdict

d = defaultdict(list)
for a, b in d1.items() + d2.items():
    d[a].append(b)

This view is not constrained

Just click this and it will be solved

Angular 2 filter/search list

In angular 2 we don't have pre-defined filter and order by as it was with AngularJs, we need to create it for our requirements. It is time killing but we need to do it, (see No FilterPipe or OrderByPipe). In this article we are going to see how we can create filter called pipe in angular 2 and sorting feature called Order By. Let's use a simple dummy json data array for it. Here is the json we will use for our example

First we will see how to use the pipe (filter) by using the search feature:

Create a component with name category.component.ts

_x000D_

    import { Component, OnInit } from '@angular/core';_x000D_
    @Component({_x000D_
      selector: 'app-category',_x000D_
      templateUrl: './category.component.html'_x000D_
    })_x000D_
    export class CategoryComponent implements OnInit {_x000D_
_x000D_
      records: Array<any>;_x000D_
      isDesc: boolean = false;_x000D_
      column: string = 'CategoryName';_x000D_
      constructor() { }_x000D_
_x000D_
      ngOnInit() {_x000D_
        this.records= [_x000D_
          { CategoryID: 1,  CategoryName: "Beverages", Description: "Coffees, teas" },_x000D_
          { CategoryID: 2,  CategoryName: "Condiments", Description: "Sweet and savory sauces" },_x000D_
          { CategoryID: 3,  CategoryName: "Confections", Description: "Desserts and candies" },_x000D_
          { CategoryID: 4,  CategoryName: "Cheeses",  Description: "Smetana, Quark and Cheddar Cheese" },_x000D_
          { CategoryID: 5,  CategoryName: "Grains/Cereals", Description: "Breads, crackers, pasta, and cereal" },_x000D_
          { CategoryID: 6,  CategoryName: "Beverages", Description: "Beers, and ales" },_x000D_
          { CategoryID: 7,  CategoryName: "Condiments", Description: "Selishes, spreads, and seasonings" },_x000D_
          { CategoryID: 8,  CategoryName: "Confections", Description: "Sweet breads" },_x000D_
          { CategoryID: 9,  CategoryName: "Cheeses",  Description: "Cheese Burger" },_x000D_
          { CategoryID: 10, CategoryName: "Grains/Cereals", Description: "Breads, crackers, pasta, and cereal" }_x000D_
         ];_x000D_
         // this.sort(this.column);_x000D_
      }_x000D_
    }

_x000D_

<div class="col-md-12">_x000D_
  <table class="table table-responsive table-hover">_x000D_
    <tr>_x000D_
      <th >Category ID</th>_x000D_
      <th>Category</th>_x000D_
      <th>Description</th>_x000D_
    </tr>_x000D_
    <tr *ngFor="let item of records">_x000D_
      <td>{{item.CategoryID}}</td>_x000D_
      <td>{{item.CategoryName}}</td>_x000D_
      <td>{{item.Description}}</td>_x000D_
    </tr>_x000D_
  </table>_x000D_
</div>

_x000D_

2.Nothing special in this code just initialize our records variable with a list of categories, two other variables isDesc and column are declared which we will use for sorting latter. At the end added this.sort(this.column); latter we will use, once we will have this method.

Note templateUrl: './category.component.html', which we will create next to show the records in tabluar format.

For this create a HTML page called category.component.html, whith following code:

3.Here we use ngFor to repeat the records and show row by row, try to run it and we can see all records in a table.

Search - Filter Records

Say we want to search the table by category name, for this let's add one text box to type and search

_x000D_

<div class="form-group">_x000D_
  <div class="col-md-6" >_x000D_
    <input type="text" [(ngModel)]="searchText" _x000D_
           class="form-control" placeholder="Search By Category" />_x000D_
  </div>_x000D_
</div>

_x000D_

5.Now we need to create a pipe to search the result by category because filter is not available as it was in angularjs any more.

Create a file category.pipe.ts and add following code in it.

_x000D_

    import { Pipe, PipeTransform } from '@angular/core';_x000D_
    @Pipe({ name: 'category' })_x000D_
    export class CategoryPipe implements PipeTransform {_x000D_
      transform(categories: any, searchText: any): any {_x000D_
        if(searchText == null) return categories;_x000D_
_x000D_
        return categories.filter(function(category){_x000D_
          return category.CategoryName.toLowerCase().indexOf(searchText.toLowerCase()) > -1;_x000D_
        })_x000D_
      }_x000D_
    }

_x000D_

6.Here in transform method we are accepting the list of categories and search text to search/filter record on the list. Import this file into our category.component.ts file, we want to use it here, as follows:

_x000D_

import { CategoryPipe } from './category.pipe';_x000D_
@Component({      _x000D_
  selector: 'app-category',_x000D_
  templateUrl: './category.component.html',_x000D_
  pipes: [CategoryPipe]   // This Line       _x000D_
})

_x000D_

7.Our ngFor loop now need to have our Pipe to filter the records so change it to this.You can see the output in image below

enter image description here

PHP cURL error code 60

Problem fixed, download https://curl.haxx.se/ca/cacert.pem and put it "somewhere", and add this line in php.ini :

curl.cainfo = "C:/somewhere/cacert.pem"

PS: I got this error by trying to install module on drupal with xampp.

Calendar date to yyyy-MM-dd format in java

java.time

The answer by MadProgrammer is correct, especially the tip about Joda-Time. The successor to Joda-Time is now built into Java 8 as the new java.time package. Here's example code in Java 8.

When working with date-time (as opposed to local date), the time zone in critical. The day-of-month depends on the time zone. For example, the India time zone is +05:30 (five and a half hours ahead of UTC), while France is only one hour ahead. So a moment in a new day in India has one date while the same moment in France has “yesterday’s” date. Creating string output lacking any time zone or offset information is creating ambiguity. You asked for YYYY-MM-DD output so I provided, but I don't recommend it. Instead of ISO_LOCAL_DATE I would have used ISO_DATE to get this output: 2014-02-25+05:30

ZoneId zoneId = ZoneId.of( "Asia/Kolkata" );
ZonedDateTime zonedDateTime = ZonedDateTime.now( zoneId );

DateTimeFormatter formatterOutput = DateTimeFormatter.ISO_LOCAL_DATE; // Caution: The "LOCAL" part means we are losing time zone information, creating ambiguity.
String output = formatterOutput.format( zonedDateTime );

Dump to console…

System.out.println( "zonedDateTime: " + zonedDateTime );
System.out.println( "output: " + output );

When run…

zonedDateTime: 2014-02-25T14:22:20.919+05:30[Asia/Kolkata]
output: 2014-02-25

Joda-Time

Similar code using the Joda-Time library, the precursor to java.time.

DateTimeZone zone = new DateTimeZone( "Asia/Kolkata" );
DateTime dateTime = DateTime.now( zone );
DateTimeFormatter formatter = ISODateTimeFormat.date();
String output = formatter.print( dateTime );

ISO 8601

By the way, that format of your input string is a standard format, one of several handy date-time string formats defined by ISO 8601.

Both Joda-Time and java.time use ISO 8601 formats by default when parsing and generating string representations of various date-time values.

Mipmap drawables for icons

When building separate apks for different densities, drawable folders for other densities get stripped. This will make the icons appear blurry in devices that use launcher icons of higher density. Since, mipmap folders do not get stripped, it’s always best to use them for including the launcher icons.

Chain-calling parent initialisers in python

You can simply write :

class A(object):

    def __init__(self):
        print "Initialiser A was called"

class B(A):

    def __init__(self):
        A.__init__(self)
        # A.__init__(self,<parameters>) if you want to call with parameters
        print "Initialiser B was called"

class C(B):

    def __init__(self):
        # A.__init__(self) # if you want to call most super class...
        B.__init__(self)
        print "Initialiser C was called"

No server in Eclipse; trying to install Tomcat

In {workspace-directory}/.metadata/.plugins/org.eclipse.core.runtime/.settings delete the following two files:
- org.eclipse.wst.server.core.prefs
- org.eclipse.jst.server.tomcat.core.prefs
Restart Eclipse

Submitting a form by pressing enter without a submit button

I work with a bunch of UI frameworks. Many of them have a built-in class you can use to visually hide things.

Bootstrap

<input type="submit" class="sr-only" tabindex="-1">

Angular Material

<input type="submit" class="cdk-visually-hidden" tabindex="-1">

Brilliant minds who created these frameworks have defined these styles as follows:

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.cdk-visually-hidden {
    border: 0;
    clip: rect(0 0 0 0);
    height: 1px;
    margin: -1px;
    overflow: hidden;
    padding: 0;
    position: absolute;
    width: 1px;
    outline: 0;
    -webkit-appearance: none;
    -moz-appearance: none;
}

How to display a "busy" indicator with jQuery?

yes, it's really just a matter of showing/hiding an animated gif.

Android screen size HDPI, LDPI, MDPI

Check out this awesome converter. http://labs.rampinteractive.co.uk/android_dp_px_calculator/

Selecting a row of pandas series/dataframe by integer index

echoing @HYRY, see the new docs in 0.11

http://pandas.pydata.org/pandas-docs/stable/indexing.html

Here we have new operators, .iloc to explicity support only integer indexing, and .loc to explicity support only label indexing

e.g. imagine this scenario

In [1]: df = pd.DataFrame(np.random.rand(5,2),index=range(0,10,2),columns=list('AB'))

In [2]: df
Out[2]: 
          A         B
0  1.068932 -0.794307
2 -0.470056  1.192211
4 -0.284561  0.756029
6  1.037563 -0.267820
8 -0.538478 -0.800654

In [5]: df.iloc[[2]]
Out[5]: 
          A         B
4 -0.284561  0.756029

In [6]: df.loc[[2]]
Out[6]: 
          A         B
2 -0.470056  1.192211

[] slices the rows (by label location) only

catching stdout in realtime from subprocess

    p = subprocess.Popen(command,
                                bufsize=0,
                                universal_newlines=True)

I am writing a GUI for rsync in python, and have the same probelms. This problem has troubled me for several days until i find this in pyDoc.

If universal_newlines is True, the file objects stdout and stderr are opened as text files in universal newlines mode. Lines may be terminated by any of '\n', the Unix end-of-line convention, '\r', the old Macintosh convention or '\r\n', the Windows convention. All of these external representations are seen as '\n' by the Python program.

It seems that rsync will output '\r' when translate is going on.

What does 'foo' really mean?

In my opinion every programmer has his or her own "words" that is used every time you need an arbitrary word when programming. For some people it's the first words from a childs song, for other it's names and for other its something completely different. Now for the programmer community there are these "words" as well, and these words are 'foo' and 'bar'. The use of this is that if you have to communicate publicly about programming you don't have to say that you would use arbitratry words, you would simply write 'foo' or 'bar' and every programmer knows that this is just arbitrary words.

Best way to format multiple 'or' conditions in an if statement (Java)

With Java 8, you could use a primitive stream:

if (IntStream.of(12, 16, 19).anyMatch(i -> i == x))

but this may have a slight overhead (or not), depending on the number of comparisons.

How to check currently internet connection is available or not in android

if you want to check the internet connection and it changes such wifi disconnection or mobile data you can use this library.

internet connection library

Format an Excel column (or cell) as Text in C#?

Use your WorkSheet.Columns.NumberFormat, and set it to string "@", here is the sample:

Excel._Worksheet workSheet = (Excel._Worksheet)_Excel.Worksheets.Add();
//set columns format to text format
workSheet.Columns.NumberFormat = "@";

Note: this text format will apply for your hole excel sheet!

If you want a particular column to apply the text format, for example, the first column, you can do this:

workSheet.Columns[0].NumberFormat = "@";

or this will apply the specified range of woorkSheet to text format:

workSheet.get_Range("A1", "D1").NumberFormat = "@";

bootstrap 3 - how do I place the brand in the center of the navbar?

css:

.navbar-header {
    float: left;
    padding: 15px;
    text-align: center;
    width: 100%;
}
.navbar-brand {float:none;}

html:

<nav class="navbar navbar-default" role="navigation">
  <div class="navbar-header">
    <a class="navbar-brand" href="#">Brand</a>
  </div>
</nav>

Creating a list/array in excel using VBA to get a list of unique names in a column

I realize this is an old question, but I use a much simpler way. Typically I just grab the list that I need, either by query or copying an existing list or whatever, then remove the duplicates. We will assume for this answer that your list is already in column C, row 4, as per the original question. This method works for whatever size list you have and you can select header yes or no.

Dim rng as range
Range("C4").Select
Set rng = Range(Selection, Selection.End(xlDown))
rng.RemoveDuplicates Columns:=1, Header:=xlYes

When to use RDLC over RDL reports?

Q: What is the difference between RDL and RDLC formats?

A: RDL files are created by the SQL Server 2005 version of Report Designer. RDLC files are created by the Visual Studio 2008 version of Report Designer.

RDL and RDLC formats have the same XML schema. However, in RDLC files, some values (such as query text) are allowed to be empty, which means that they are not immediately ready to be published to a Report Server. The missing values can be entered by opening the RDLC file using the SQL Server 2005 version of Report Designer. (You have to rename .rdlc to .rdl first.)

RDL files are fully compatible with the ReportViewer control runtime. However, RDL files do not contain some information that the design-time of the ReportViewer control depends on for automatically generating data-binding code. By manually binding data, RDL files can be used in the ReportViewer control. New! See also the RDL Viewer sample program.

Note that the ReportViewer control does not contain any logic for connecting to databases or executing queries. By separating out such logic, the ReportViewer has been made compatible with all data sources, including non-database data sources. However this means that when an RDL file is used by the ReportViewer control, the SQL related information in the RDL file is simply ignored by the control. It is the host application's responsibility to connect to databases, execute queries and supply data to the ReportViewer control in the form of ADO.NET DataTables.

http://www.gotreportviewer.com/

The infamous java.sql.SQLException: No suitable driver found

I've forgot to add the PostgreSQL JDBC Driver into my project (Mvnrepository).

Gradle:

// http://mvnrepository.com/artifact/postgresql/postgresql
compile group: 'postgresql', name: 'postgresql', version: '9.0-801.jdbc4'

Maven:

<dependency>
    <groupId>postgresql</groupId>
    <artifactId>postgresql</artifactId>
    <version>9.0-801.jdbc4</version>
</dependency>

You can also download the JAR and import to your project manually.

How can I use JavaScript in Java?

Rhino is what you are looking for.

Rhino is an open-source implementation of JavaScript written entirely in Java. It is typically embedded into Java applications to provide scripting to end users.

Update: Now Nashorn, which is more performant JavaScript Engine for Java, is available with jdk8.

How to make link not change color after visited?

Text decoration affects the underline, not the color.

To set the visited color to the same as the default, try:

a { 
    color: blue;
}

a {
    text-decoration: none;
}
a:link, a:visited {
    color: blue;
}
a:hover {
    color: red;
}

How can I copy a file on Unix using C?

#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>

#define    print_err(format, args...)   printf("[%s:%d][error]" format "\n", __func__, __LINE__, ##args)
#define    DATA_BUF_SIZE                (64 * 1024)    //limit to read maximum 64 KB data per time

int32_t get_file_size(const char *fname){
    struct stat sbuf;

    if (NULL == fname || strlen(fname) < 1){
        return 0;
    }

    if (stat(fname, &sbuf) < 0){
        print_err("%s, %s", fname, strerror(errno));
        return 0;
    }

    return sbuf.st_size; /* off_t shall be signed interge types, used for file size */
}

bool copyFile(CHAR *pszPathIn, CHAR *pszPathOut)
{
    INT32 fdIn, fdOut;
    UINT32 ulFileSize_in = 0;
    UINT32 ulFileSize_out = 0;
    CHAR *szDataBuf;

    if (!pszPathIn || !pszPathOut)
    {
        print_err(" Invalid param!");
        return false;
    }

    if ((1 > strlen(pszPathIn)) || (1 > strlen(pszPathOut)))
    {
        print_err(" Invalid param!");
        return false;
    }

    if (0 != access(pszPathIn, F_OK))
    {
        print_err(" %s, %s!", pszPathIn, strerror(errno));
        return false;
    }

    if (0 > (fdIn = open(pszPathIn, O_RDONLY)))
    {
        print_err("open(%s, ) failed, %s", pszPathIn, strerror(errno));
        return false;
    }

    if (0 > (fdOut = open(pszPathOut, O_CREAT | O_WRONLY | O_TRUNC, 0777)))
    {
        print_err("open(%s, ) failed, %s", pszPathOut, strerror(errno));
        close(fdIn);
        return false;
    }

    szDataBuf = malloc(DATA_BUF_SIZE);
    if (NULL == szDataBuf)
    {
        print_err("malloc() failed!");
        return false;
    }

    while (1)
    {
        INT32 slSizeRead = read(fdIn, szDataBuf, sizeof(szDataBuf));
        INT32 slSizeWrite;
        if (slSizeRead <= 0)
        {
            break;
        }

        slSizeWrite = write(fdOut, szDataBuf, slSizeRead);
        if (slSizeWrite < 0)
        {
            print_err("write(, , slSizeRead) failed, %s", slSizeRead, strerror(errno));
            break;
        }

        if (slSizeWrite != slSizeRead) /* verify wheter write all byte data successfully */
        {
            print_err(" write(, , %d) failed!", slSizeRead);
            break;
        }
    }

    close(fdIn);
    fsync(fdOut); /* causes all modified data and attributes to be moved to a permanent storage device */
    close(fdOut);

    ulFileSize_in = get_file_size(pszPathIn);
    ulFileSize_out = get_file_size(pszPathOut);
    if (ulFileSize_in == ulFileSize_out) /* verify again wheter write all byte data successfully */
    {
        free(szDataBuf);
        return true;
    }
    free(szDataBuf);
    return false;
}

bootstrap 3 wrap text content within div for horizontal alignment

1) Maybe oveflow: hidden; will do the trick?

2) You need to set the size of each div with the text and button so that each of these divs have the same height. Then for your button:

button {
  position: absolute;
  bottom: 0;
}

Execute a large SQL script (with GO commands)

I had the same problem in java and I solved it with a bit of logic and regex. I believe the same logic can be applied.First I read from the slq file into memory. Then I apply the following logic. It's pretty much what has been said before however I believe that using regex word bound is safer than expecting a new line char.

String pattern = "\\bGO\\b|\\bgo\\b";

String[] splitedSql = sql.split(pattern);
for (String chunk : splitedSql) {
  getJdbcTemplate().update(chunk);
}

This basically splits the sql string into an array of sql strings. The regex is basically to detect full 'go' words either lower case or upper case. Then you execute the different querys sequentially.

How to edit a text file in my terminal

If you are still inside the vi editor, you might be in a different mode from the one you want. Hit ESC a couple of times (until it rings or flashes) and then "i" to enter INSERT mode or "a" to enter APPEND mode (they are the same, just start before or after current character).

If you are back at the command prompt, make sure you can locate the file, then navigate to that directory and perform the mentioned "vi helloWorld.txt". Once you are in the editor, you'll need to check the vi reference to know how to perform the editions you want (you may want to google "vi reference" or "vi cheat sheet").

Once the edition is done, hit ESC again, then type :wq to save your work or :q! to quit without saving.

For quick reference, here you have a text-based cheat sheet.

Convert integer to hexadecimal and back again

Print integer in hex-value with zero-padding (if needed) :

int intValue = 1234;

Console.WriteLine("{0,0:D4} {0,0:X3}", intValue);

https://docs.microsoft.com/en-us/dotnet/standard/base-types/how-to-pad-a-number-with-leading-zeros

Installing PHP Zip Extension

Simply use sudo yum install php-zip

Smooth scroll to specific div on click

There are many examples of smooth scrolling using JS libraries like jQuery, Mootools, Prototype, etc.

The following example is on pure JavaScript. If you have no jQuery/Mootools/Prototype on page or you don't want to overload page with heavy JS libraries the example will be of help.

http://jsfiddle.net/rjSfP/

HTML Part:

<div class="first"><button type="button" onclick="smoothScroll(document.getElementById('second'))">Click Me!</button></div>
<div class="second" id="second">Hi</div>

CSS Part:

.first {
    width: 100%;
    height: 1000px;
    background: #ccc;
}

.second {
    width: 100%;
    height: 1000px;
    background: #999;
}

JS Part:

window.smoothScroll = function(target) {
    var scrollContainer = target;
    do { //find scroll container
        scrollContainer = scrollContainer.parentNode;
        if (!scrollContainer) return;
        scrollContainer.scrollTop += 1;
    } while (scrollContainer.scrollTop == 0);

    var targetY = 0;
    do { //find the top of target relatively to the container
        if (target == scrollContainer) break;
        targetY += target.offsetTop;
    } while (target = target.offsetParent);

    scroll = function(c, a, b, i) {
        i++; if (i > 30) return;
        c.scrollTop = a + (b - a) / 30 * i;
        setTimeout(function(){ scroll(c, a, b, i); }, 20);
    }
    // start scrolling
    scroll(scrollContainer, scrollContainer.scrollTop, targetY, 0);
}

MySql Error: 1364 Field 'display_name' doesn't have default value

I got this error when I forgot to add new form fields/database columns to the $fillable array in the Laravel model - the model was stripping them out.

Nodejs cannot find installed module on Windows

Add an environment variable called NODE_PATH and set it to %USERPROFILE%\Application Data\npm\node_modules (Windows XP), %AppData%\npm\node_modules (Windows 7/8/10), or wherever npm ends up installing the modules on your Windows flavor. To be done with it once and for all, add this as a System variable in the Advanced tab of the System Properties dialog (run control.exe sysdm.cpl,System,3).

Quick solution in Windows 7+ is to just run:

rem for future
setx NODE_PATH %AppData%\npm\node_modules
rem for current session
set NODE_PATH=%AppData%\npm\node_modules

It's worth to mention that NODE_PATH is only used when importing modules in Node apps. When you want to use globally installed modules' binaries in your CLI you need to add it also to your PATH, but without node_modules part (for example %AppData%\npm in Windows 7/8/10).

Old story

I'm pretty much new to node.js myself so I can be not entirely right but from my experience it's works this way:

-g is not a way to install global libraries, it's only a way to place them on system path so you can call them from command line without writing the full path to them. It is useful, for example, then node app is converting local files, like less — if you install it globally you can use it in any directory.
node.js itself didn't look at the npm global dir, it is using another algorithm to find required files: http://nodejs.org/api/modules.html#modules_file_modules (basically its scanning every folder in the path, starting from the current for node_modules folder and checks it).

See similar question for more details: How do I install a module globally using npm?

Select columns based on string match - dplyr::select

Within the dplyr world, try:

select(iris,contains("Sepal"))

See the Selection section in ?select for numerous other helpers like starts_with, ends_with, etc.

How to overwrite the previous print to stdout in python?

Try this:

import time
while True:
    print("Hi ", end="\r")
    time.sleep(1)
    print("Bob", end="\r")
    time.sleep(1)

It worked for me. The end="\r" part is making it overwrite the previous line.

WARNING!

If you print out hi, then print out hello using \r, you’ll get hillo because the output wrote over the previous two letters. If you print out hi with spaces (which don’t show up here), then it will output hi. To fix this, print out spaces using \r.

What is 'Currying'?

As all other answers currying helps to create partially applied functions. Javascript does not provide native support for automatic currying. So the examples provided above may not help in practical coding. There is some excellent example in livescript (Which essentially compiles to js) http://livescript.net/

times = (x, y) --> x * y
times 2, 3       #=> 6 (normal use works as expected)
double = times 2
double 5         #=> 10

In above example when you have given less no of arguments livescript generates new curried function for you (double)

Create File If File Does Not Exist

This will enable appending to file using StreamWriter

 using (StreamWriter stream = new StreamWriter("YourFilePath", true)) {...}

This is default mode, not append to file and create a new file.

using (StreamWriter stream = new StreamWriter("YourFilePath", false)){...}
                           or
using (StreamWriter stream = new StreamWriter("YourFilePath")){...}

Anyhow if you want to check if the file exists and then do other things,you can use

using (StreamWriter sw = (File.Exists(path)) ? File.AppendText(path) : File.CreateText(path))
            {...}

Format cell if cell contains date less than today

=$W$4<=TODAY()

Returns true for dates up to and including today, false otherwise.

X-Frame-Options Allow-From multiple domains

One possible workaround would be using a "frame-breaker" script as described here

You just need to alter the "if" statement to check for your allowed domains.

   if (self === top) {
       var antiClickjack = document.getElementById("antiClickjack");
       antiClickjack.parentNode.removeChild(antiClickjack);
   } else {
       //your domain check goes here
       if(top.location.host != "allowed.domain1.com" && top.location.host == "allowed.domain2.com")
         top.location = self.location;
   }

This workaround would be safe, I think. because with javascript not enabled you will have no security concern about a malicious website framing your page.

C - The %x format specifier

From http://en.wikipedia.org/wiki/Printf_format_string

use 0 instead of spaces to pad a field when the width option is specified. For example, printf("%2d", 3) results in " 3", while printf("%02d", 3) results in "03".

EF Core add-migration Build Failed

In My case, add the package Microsoft.EntityFrameworkCore.Tools fixed problem

NullPointerException: Attempt to invoke virtual method 'int java.util.ArrayList.size()' on a null object reference

You should initialize yours recordings. You are passing to adapter null

ArrayList<String> recordings = null; //You are passing this null

How to fully delete a git repository created with init?

If you really want to remove all of the repository, leaving only the working directory then it should be as simple as this.

rm -rf .git

The usual provisos about rm -rf apply. Make sure you have an up to date backup and are absolutely sure that you're in the right place before running the command. etc., etc.

How to restrict the selectable date ranges in Bootstrap Datepicker?

Most answers and explanations are not to explain what is a valid string of endDate or startDate. Danny gave us two useful example.

$('#datepicker').datepicker({
    startDate: '-2m',
    endDate: '+2d'
});

But why?let's take a look at the source code at bootstrap-datetimepicker.js. There are some code begin line 1343 tell us how does it work.

if (/^[-+]\d+[dmwy]([\s,]+[-+]\d+[dmwy])*$/.test(date)) {
            var part_re = /([-+]\d+)([dmwy])/,
                parts = date.match(/([-+]\d+)([dmwy])/g),
                part, dir;
            date = new Date();
            for (var i = 0; i < parts.length; i++) {
                part = part_re.exec(parts[i]);
                dir = parseInt(part[1]);
                switch (part[2]) {
                    case 'd':
                        date.setUTCDate(date.getUTCDate() + dir);
                        break;
                    case 'm':
                        date = Datetimepicker.prototype.moveMonth.call(Datetimepicker.prototype, date, dir);
                        break;
                    case 'w':
                        date.setUTCDate(date.getUTCDate() + dir * 7);
                        break;
                    case 'y':
                        date = Datetimepicker.prototype.moveYear.call(Datetimepicker.prototype, date, dir);
                        break;
                }
            }
            return UTCDate(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate(), date.getUTCHours(), date.getUTCMinutes(), date.getUTCSeconds(), 0);
        }

There are four kinds of expressions.

w means week
m means month
y means year
d means day

Look at the regular expression ^[-+]\d+[dmwy]([\s,]+[-+]\d+[dmwy])*$. You can do more than these -0d or +1m.

Try harder like startDate:'+1y,-2m,+0d,-1w'.And the separator , could be one of [\f\n\r\t\v,]

SyntaxError: Cannot use import statement outside a module

Recently have the issue. The fix which work for me was to added this to babel.config.json in the plugins section

["@babel/plugin-transform-modules-commonjs", {
    "allowTopLevelThis": true,
    "loose": true,
    "lazy": true
  }],

I had some imported module with // and the error "cannot use import outside a module".

org.glassfish.jersey.servlet.ServletContainer ClassNotFoundException

I agree with the accepted answer. But for me, the issue was not that, instead I had to modify my Servlet-Class name from:-

<servlet-class>org.glassfish.jersey.servlet.ServletContainer.class</servlet-class>

To:

<servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>

So, removing .class worked fine in my case. Hope it will help somebody!

Python POST binary data

You can use unirest, It provides easy method to post request. `

import unirest
 
def callback(response):
 print "code:"+ str(response.code)
 print "******************"
 print "headers:"+ str(response.headers)
 print "******************"
 print "body:"+ str(response.body)
 print "******************"
 print "raw_body:"+ str(response.raw_body)
 
# consume async post request
def consumePOSTRequestASync():
 params = {'test1':'param1','test2':'param2'}
 
 # we need to pass a dummy variable which is open method
 # actually unirest does not provide variable to shift between
 # application-x-www-form-urlencoded and
 # multipart/form-data
  
 params['dummy'] = open('dummy.txt', 'r')
 url = 'http://httpbin.org/post'
 headers = {"Accept": "application/json"}
 # call get service with headers and params
 unirest.post(url, headers = headers,params = params, callback = callback)
 
 
# post async request multipart/form-data
consumePOSTRequestASync()

Find what 2 numbers add to something and multiply to something

That's basically a set of 2 simultaneous equations:

x*y = a
X+y = b

(using the mathematical convention of x and y for the variables to solve and a and b for arbitrary constants).

But the solution involves a quadratic equation (because of the x*y), so depending on the actual values of a and b, there may not be a solution, or there may be multiple solutions.

How to sum columns in a dataTable?

 for (int i=0;i<=dtB.Columns.Count-1;i++)
 {
   array(0, i) = dtB.Compute("SUM([" & dtB.Columns(i).ColumnName & "])", "")                   
 }

How to change the Eclipse default workspace?

Open a command prompt. Change to the eclipse home directory and type "eclipse -clean" e.g. C:/eclipse>eclipse -clean

This will ask for the workspace selection. It will also force to set it as the default workspace.

Then, go to eclipsehome-->configuration-->settings folder.

open org.eclipse.ui.de.prefs in a notepad.

set this property to true from false.

SHOW_WORKSPACE_SELECTION_DIALOG=true

You will be asked for a workspace selection everytime.

jQuery Set Selected Option Using Next

  $("select").prop("selectedIndex",$("select").prop("selectedIndex")+1)

Thymeleaf: how to use conditionals to dynamically add/remove a CSS class

Yet another usage of th:class, same as @NewbLeech and @Charles have posted, but simplified to maximum if there is no "else" case:

<input th:class="${#fields.hasErrors('password')} ? formFieldHasError" />

Does not include class attribute if #fields.hasErrors('password') is false.

Android ImageView setImageResource in code

You can use this code:

// Create an array that matches any country to its id (as String):
String[][] countriesId = new String[NUMBER_OF_COUNTRIES_SUPPORTED][];

// Initialize the array, where the first column will be the country's name (in uppercase) and the second column will be its id (as String):
countriesId[0] = new String[] {"US", String.valueOf(R.drawable.us)};
countriesId[1] = new String[] {"FR", String.valueOf(R.drawable.fr)};
// and so on...

// And after you get the variable "countryCode":
int i;
for(i = 0; i<countriesId.length; i++) {
   if(countriesId[i][0].equals(countryCode))
      break;
}
// Now "i" is the index of the country

img.setImageResource(Integer.parseInt(countriesId[i][1]));

Correlation heatmap

Use the 'jet' colormap for a transition between blue and red.
Use pcolor() with the vmin, vmax parameters.

It is detailed in this answer: https://stackoverflow.com/a/3376734/21974

Git "error: The branch 'x' is not fully merged"

I had this happen to me today, as I was merging my very first feature branch back into master. As some said in a thread elsewhere on SO, the trick was switching back to master before trying to delete the branch. Once in back in master, git was happy to delete the branch without any warnings.

Redis command to get all available keys?

redis-cli -h <host> -p <port> keys *

where * is the pattern to list all keys

Write HTML to string

You could use some third party open-source libraries to generated strong typed verified (X)HTML, such as CityLizard Framework or Sharp DOM.

Update For example

html
    [head
        [title["Title of the page"]]
        [meta_(
            content: "text/html;charset=UTF-8",
            http_equiv: "Content-Type")
        ]
        [link_(href: "css/style.css", rel: "stylesheet", type: "text/css")]
        [script_(type: "text/javascript", src: "/JavaScript/jquery-1.4.2.min.js")]
    ]
    [body
        [div
            [h1["Test Form to Test"]]
            [form_(action: "post", id: "Form1")
                [div
                    [label["Parameter"]]
                    [input_(type: "text", value: "Enter value")]
                    [input_(type: "submit", value: "Submit!")]
                ]
            ]
            [div
                [p["Textual description of the footer"]]
                [a_(href: "http://google.com/")
                    [span["You can find us here"]]
                ]
                [div["Another nested container"]]
            ]
        ]
    ];

Google Chrome "window.open" workaround?

As far as I can tell, chrome doesn't work properly if you are referencing localhost (say, you're developing a site locally)

This works:

var windowObjectReference;
var strWindowFeatures = "menubar=yes,location=yes,resizable=yes,scrollbars=yes,status=yes";

function openRequestedPopup() {
  windowObjectReference = window.open("http://www.cnn.com/", "CNN_WindowName", strWindowFeatures);
}

This does not work

var windowObjectReference;
var strWindowFeatures = "menubar=yes,location=yes,resizable=yes,scrollbars=yes,status=yes";

function openRequestedPopup() {
  windowObjectReference = window.open("http://localhost/webappFolder/MapViewer.do", "CNN_WindowName", strWindowFeatures);
}

This also does not work, when loaded from http://localhost/webappFolder/Landing.do

var windowObjectReference;
var strWindowFeatures = "menubar=yes,location=yes,resizable=yes,scrollbars=yes,status=yes";

function openRequestedPopup() {
  windowObjectReference = window.open("/webappFolder/MapViewer.do", "CNN_WindowName", strWindowFeatures);
}

How do I install opencv using pip?

On Ubuntu you can install it for the system Python with

sudo apt install python3-opencv

Is there an upper bound to BigInteger?

The first maximum you would hit is the length of a String which is 2³¹-1 digits. It's much smaller than the maximum of a BigInteger but IMHO it loses much of its value if it can't be printed.

Repair all tables in one go

Use following query to print REPAIR SQL statments for all tables inside a database:

select concat('REPAIR TABLE ', table_name, ';') from information_schema.tables 
where table_schema='mydatabase';

After that copy all the queries and execute it on mydatabase.

Note: replace mydatabase with desired DB name

'sprintf': double precision in C

The problem is with sprintf

sprintf(aa,"%lf",a);

%lf says to interpet "a" as a "long double" (16 bytes) but it is actually a "double" (8 bytes). Use this instead:

sprintf(aa, "%f", a);

More details here on cplusplus.com

Make Font Awesome icons in a circle?

This is the best and most precise solution I've found so far.

CSS:

.social .fa {
      margin-right: 1rem;
      border: 2px #fff solid;
      border-radius: 50%;
      height: 20px;
      width: 20px;
      line-height: 20px;
      text-align: center;
      padding: 0.5rem;
    }

SQL query to make all data in a column UPPER CASE?

Permanent:

UPDATE
  MyTable
SET
  MyColumn = UPPER(MyColumn)

Temporary:

SELECT
  UPPER(MyColumn) AS MyColumn
FROM
  MyTable

Missing `server' JVM (Java\jre7\bin\server\jvm.dll.)

To Fix The "Missing "server" JVM at C:\Program Files\Java\jre7\bin\server\jvm.dll, please install or use the JRE or JDK that contains these missing components.

Follow these steps:

Go to oracle.com and install Java JRE7 (Check if Java 6 is not installed already)

After that, go to C:/Program files/java/jre7/bin

Here, create an folder called Server

Now go into the C:/Program files/java/jre7/bin/client folder

Copy all the data in this folder into the new C:/Program files/java/jre7/bin/Server folder

"Could not find a version that satisfies the requirement opencv-python"

pip doesn't use http://www.lfd.uci.edu/~gohlke/pythonlibs/, it downloads packages from PyPI.

The problem is that you have an unusual architecture; pip cannot find a package for it and there is no source code package.

Unfortunately I think you're on your own. You have to download source code from https://github.com/skvark/opencv-python, install compiler and necessary libraries and compile OpenCV yourself.

libstdc++.so.6: cannot open shared object file: No such file or directory

For Red Hat :

sudo yum install libstdc++.i686
sudo yum install libstdc++-devel.i686

What is the cause for "angular is not defined"

I had the same problem as deke. I forgot to include the most important script: angular.js :)

<script type="text/javascript" src="bower_components/angular/angular.min.js"></script>

How to load my app from Eclipse to my Android phone instead of AVD

What I did, by reading all of above answers and it worked as well: 7 deadly steps

Connect your android phone with the pc on which you are running eclipse/your map project.
Let it install all the necessary drivers.. When done, open your smart phone, go to: Settings > Applications > Development > USB debugging and enable it on by clicking on the check button at the right side.
Also, enable Settings > Unknowresoures
Come back to eclipse on your pc. Right click on the project/application, Run As > Run configurations... >Choose Device>Target Select your device Run.
Click on the Target tab from top. By default it is on the first tab Android
Choose the second radio button which says Launch on all compatible deivces/AVDs. Then click Apply at the bottom and afterwards, click Run.
Here you go, it will automatically install your application's .apk file into your smart phone and make it run over it., just like on emulator.

If you get it running, please help others too.

JavaScript backslash (\) in variables is causing an error

The jsfiddle link to where i tried out your query http://jsfiddle.net/A8Dnv/1/ its working fine @Imrul as mentioned you are using C# on server side and you dont mind that either: http://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex.escape.aspx

Htaccess: add/remove trailing slash from URL

Right below the RewriteEngine On line, add:

RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)/$ /$1 [L,R] # <- for test, for prod use [L,R=301]

to enforce a no-trailing-slash policy.

To enforce a trailing-slash policy:

RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*[^/])$ /$1/ [L,R] # <- for test, for prod use [L,R=301]

EDIT: commented the R=301 parts because, as explained in a comment:

Be careful with that R=301! Having it there makes many browsers cache the .htaccess-file indefinitely: It somehow becomes irreversible if you can't clear the browser-cache on all machines that opened it. When testing, better go with simple R or R=302

After you've completed your tests, you can use R=301.

JPA OneToMany not deleting child

As explained, it is not possible to do what I want with JPA, so I employed the hibernate.cascade annotation, with this, the relevant code in the Parent class now looks like this:

@OneToMany(cascade = {CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REFRESH}, mappedBy = "parent")
@Cascade({org.hibernate.annotations.CascadeType.SAVE_UPDATE,
            org.hibernate.annotations.CascadeType.DELETE,
            org.hibernate.annotations.CascadeType.MERGE,
            org.hibernate.annotations.CascadeType.PERSIST,
            org.hibernate.annotations.CascadeType.DELETE_ORPHAN})
private Set<Child> childs = new HashSet<Child>();

I could not simple use 'ALL' as this would have deleted the parent as well.

Is Ruby pass by reference or by value?

Ruby is interpreted. Variables are references to data, but not the data itself. This facilitates using the same variable for data of different types.

Assignment of lhs = rhs then copies the reference on the rhs, not the data. This differs in other languages, such as C, where assignment does a data copy to lhs from rhs.

So for the function call, the variable passed, say x, is indeed copied into a local variable in the function, but x is a reference. There will then be two copies of the reference, both referencing the same data. One will be in the caller, one in the function.

Assignment in the function would then copy a new reference to the function's version of x. After this the caller's version of x remains unchanged. It is still a reference to the original data.

In contrast, using the .replace method on x will cause ruby to do a data copy. If replace is used before any new assignments then indeed the caller will see the data change in its version also.

Similarly, as long as the original reference is in tact for the passed in variable, the instance variables will be the same that the caller sees. Within the framework of an object, the instance variables always have the most up to date reference values, whether those are provided by the caller or set in the function the class was passed in to.

The 'call by value' or 'call by reference' is muddled here because of confusion over '=' In compiled languages '=' is a data copy. Here in this interpreted language '=' is a reference copy. In the example you have the reference passed in followed by a reference copy though '=' that clobbers the original passed in reference, and then people talking about it as though '=' were a data copy.

To be consistent with definitions we must keep with '.replace' as it is a data copy. From the perspective of '.replace' we see that this is indeed pass by reference. Furthermore, if we walk through in the debugger, we see references being passed in, as variables are references.

However if we must keep '=' as a frame of reference, then indeed we do get to see the passed in data up until an assignment, and then we don't get to see it anymore after assignment while the caller's data remains unchanged. At a behavioral level this is pass by value as long as we don't consider the passed in value to be composite - as we won't be able to keep part of it while changing the other part in a single assignment (as that assignment changes the reference and the original goes out of scope). There will also be a wart, in that instance variables in objects will be references, as are all variables. Hence we will be forced to talk about passing 'references by value' and have to use related locutions.

Call a function from another file?

First of all you do not need a .py.

If you have a file a.py and inside you have some functions:

def b():
  # Something
  return 1

def c():
  # Something
  return 2

And you want to import them in z.py you have to write

from a import b, c

OnItemClickListener using ArrayAdapter for ListView

Use OnItemClickListener

   ListView lv = getListView();
   lv.setOnItemClickListener(new OnItemClickListener()
   {
      @Override
      public void onItemClick(AdapterView<?> adapter, View v, int position,
            long arg3) 
      {
            String value = (String)adapter.getItemAtPosition(position); 
            // assuming string and if you want to get the value on click of list item
            // do what you intend to do on click of listview row
      }
   });

When you click on a row a listener is fired. So you setOnClickListener on the listview and use the annonymous inner class OnItemClickListener.

You also override onItemClick. The first param is a adapter. Second param is the view. third param is the position ( index of listview items).

Using the position you get the item .

Edit : From your comments i assume you need to set the adapter o listview

So assuming your activity extends ListActivtiy

     setListAdapter(adapter);

Or if your activity class extends Activity

     ListView lv = (ListView) findViewById(R.id.listview1);
     //initialize adapter 
     lv.setAdapter(adapter);

var path = System.IO.Path.GetDirectoryName( 
      System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase);

MSDN has a full reference on how to determine the Executing Application's Path.

Note that the value in path will be in the form of file:\c:\path\to\bin\folder, so before using the path you may need to strip the file:\ off the front. E.g.:

path = path.Substring(6);

Programs & Examples On #Pluralize

Convert String (UTF-16) to UTF-8 in C#

Sending HTML mail using a shell script

No log4j2 configuration file found. Using default configuration: logging only errors to the console

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

Django - limiting query results

Merge development branch with master

Error: "Input is not proper UTF-8, indicate encoding !" using PHP's simplexml_load_string

How do I concatenate two strings in C?

How can I tell if a VARCHAR variable contains a substring?

ImportError: No module named psycopg2

npm ERR! code UNABLE_TO_GET_ISSUER_CERT_LOCALLY

npm WARN ... requires a peer of ... but none is installed. You must install peer dependencies yourself

Using Pip to install packages to Anaconda Environment

JavaScript: set dropdown selected item based on option text

Use a JSON array with objects with javascript

How to downgrade to older version of Gradle

uninstalling android with the following commands

ClassNotFoundException: org.slf4j.LoggerFactory

How to view hierarchical package structure in Eclipse package explorer

How can I view the Git history in Visual Studio Code?

Timeline view

How to check a Long for null in java

Sometimes adding a WCF Service Reference generates an empty reference.cs

How do you fix a MySQL "Incorrect key file" error when you can't repair the table?

Sass .scss: Nesting and multiple classes?

Web-scraping JavaScript page with Python

How do I put a clear button inside my HTML text input box like the iPhone does?

GIT commit as different user without email / or only email

Angular cli generate a service and include the provider in one step

How can INSERT INTO a table 300 times within a loop in SQL?

No Title Bar Android Theme

Apply CSS rules to a nested class inside a div

How do I use reflection to call a generic method?

How can I make content appear beneath a fixed DIV element?

How to compare two maps by their values

Experimental decorators warning in TypeScript compilation

Use :hover to modify the css of another class?

Delete worksheet in Excel using VBA

Is there a GUI design app for the Tkinter / grid geometry?

Linker command failed with exit code 1 - duplicate symbol __TMRbBp

C++ performance vs. Java/C#

What is the difference between T(n) and O(n)?

Short explanation:

More technically:

Sleep for milliseconds

How to convert string representation of list to a list?

Contain form within a bootstrap popover?

Can I run HTML files directly from GitHub, instead of just viewing their source?

Should I add the Visual Studio .suo and .user files to source control?

jQuery validate: How to add a rule for regular expression validation?

How do I target only Internet Explorer 10 for certain situations like Internet Explorer-specific CSS or Internet Explorer-specific JavaScript code?

Fill remaining vertical space - only CSS

maven "cannot find symbol" message unhelpful

calling a java servlet from javascript

How do I check if PHP is connected to a database already?

How to check if a network port is open on linux?

How to check if a file exists before creating a new file

git ignore all files of a certain type, except those in a specific subfolder

mysqld_safe Directory '/var/run/mysqld' for UNIX socket file don't exists

getting exception "IllegalStateException: Can not perform this action after onSaveInstanceState"

Formatting text in a TextBlock

ImportError: No module named PyQt4

Simple PHP Pagination script

Html.BeginForm and adding properties

What are the most-used vim commands/keypresses?

What dependency is missing for org.springframework.web.bind.annotation.RequestMapping?

Is there any quick way to get the last two characters in a string?

Installing tensorflow with anaconda in windows

AsyncTask Android example

Iterate through the fields of a struct in Go

How best to read a File into List<string>

How can I simulate a click to an anchor tag?

Java parsing XML document gives "Content not allowed in prolog." error

jQuery: Setting select list 'selected' based on text, failing strangely

Have Excel formulas that return 0, make the result blank

CSS border less than 1px

Keyword not supported: "data source" initializing Entity Framework Context

Warning :-Presenting view controllers on detached view controllers is discouraged

Postgresql : Connection refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections