SyntaxFix

Programs & Examples On #Activator

Activator is a .NET class that can create dynamically-typed object instances at runtime.

How to dynamically create generic C# object using reflection?

Make sure you're doing this for a good reason, a simple function like the following would allow static typing and allows your IDE to do things like "Find References" and Refactor -> Rename.

public Task <T> factory (String name)
{
  Task <T> result;

  if (name.CompareTo ("A") == 0)
  {
    result = new TaskA ();
  }
  else if (name.CompareTo ("B") == 0)
  {
    result = new TaskB ();
  }

  return result;
}

Why are you not able to declare a class as static in Java?

You can create a utility class (which cannot have instances created) by declaring an enum type with no instances. i.e. you are specificly declaring that there are no instances.

public enum MyUtilities {;
   public static void myMethod();
}

How does tuple comparison work in Python?

 I had some confusion before regarding integer comparsion, so I will explain it to be more beginner friendly with an example

a = ('A','B','C') # see it as the string "ABC" b = ('A','B','D')

A is converted to its corresponding ASCII ord('A') #65 same for other elements

So, >> a>b # True you can think of it as comparing between string (It is exactly, actually)

the same thing goes for integers too.

x = (1,2,2) # see it the string "123" y = (1,2,3) x > y # False

because (1 is not greater than 1, move to the next, 2 is not greater than 2, move to the next 2 is less than three -lexicographically -)

The key point is mentioned in the answer above

think of it as an element is before another alphabetically not element is greater than an element and in this case consider all the tuple elements as one string.

White space at top of page

overflow: auto

Using overflow: auto on the <body> tag is a cleaner solution and will work a charm.

Selenium WebDriver: Wait for complex page with JavaScript to load

You can write some logic to handle this. I have write a method that will return the WebElement and this method will be called three times or you can increase the time and add a null check for WebElement Here is an example

public static void main(String[] args) {
        WebDriver driver = new FirefoxDriver();
        driver.get("https://www.crowdanalytix.com/#home");
        WebElement webElement = getWebElement(driver, "homekkkkkkkkkkkk");
        int i = 1;
        while (webElement == null && i < 4) {
            webElement = getWebElement(driver, "homessssssssssss");
            System.out.println("calling");
            i++;
        }
        System.out.println(webElement.getTagName());
        System.out.println("End");
        driver.close();
    }

    public static WebElement getWebElement(WebDriver driver, String id) {
        WebElement myDynamicElement = null;
        try {
            myDynamicElement = (new WebDriverWait(driver, 10))
                    .until(ExpectedConditions.presenceOfElementLocated(By
                            .id(id)));
            return myDynamicElement;
        } catch (TimeoutException ex) {
            return null;
        }
    }

Check file extension in upload form in PHP

To properly achieve this, you'd be better off by checking the mime type.

function get_mime($file) {
  if (function_exists("finfo_file")) {
    $finfo = finfo_open(FILEINFO_MIME_TYPE); // return mime type ala mimetype extension
    $mime = finfo_file($finfo, $file);
    finfo_close($finfo);
    return $mime;
  } else if (function_exists("mime_content_type")) {
    return mime_content_type($file);
  } else if (!stristr(ini_get("disable_functions"), "shell_exec")) {
    // http://stackoverflow.com/a/134930/1593459
    $file = escapeshellarg($file);
    $mime = shell_exec("file -bi " . $file);
    return $mime;
  } else {
    return false;
  }
}
//pass the file name as
echo(get_mime($_FILES['file_name']['tmp_name']));

How to allow users to check for the latest app version from inside the app?

To save time writing for check new version update for android app, I written it as library and open source at https://github.com/winsontan520/Android-WVersionManager

How do I grep for all non-ASCII characters?

It could be interesting to know how to search for one unicode character. This command can help. You only need to know the code in UTF8

grep -v $'\u200d'

How to define a List bean in Spring?

Stacker posed a great answer, I would go one step farther to make it more dynamic and use Spring 3 EL Expression. 

<bean id="listBean" class="java.util.ArrayList">
        <constructor-arg>
            <value>#{springDAOBean.getGenericListFoo()}</value>
        </constructor-arg>
</bean>

I was trying to figure out how I could do this with the util:list but couldn't get it work due to conversion errors.

What is a lambda expression in C++11?

Lambda expressions are typically used to encapsulate algorithms so that they can be passed to another function. However, it is possible to execute a lambda immediately upon definition:

[&](){ ...your code... }(); // immediately executed lambda expression

is functionally equivalent to

{ ...your code... } // simple code block

This makes lambda expressions a powerful tool for refactoring complex functions. You start by wrapping a code section in a lambda function as shown above. The process of explicit parameterization can then be performed gradually with intermediate testing after each step. Once you have the code-block fully parameterized (as demonstrated by the removal of the &), you can move the code to an external location and make it a normal function.

Similarly, you can use lambda expressions to initialize variables based on the result of an algorithm...

int a = []( int b ){ int r=1; while (b>0) r*=b--; return r; }(5); // 5!

As a way of partitioning your program logic, you might even find it useful to pass a lambda expression as an argument to another lambda expression...

[&]( std::function<void()> algorithm ) // wrapper section
   {
   ...your wrapper code...
   algorithm();
   ...your wrapper code...
   }
([&]() // algorithm section
   {
   ...your algorithm code...
   });

Lambda expressions also let you create named nested functions, which can be a convenient way of avoiding duplicate logic. Using named lambdas also tends to be a little easier on the eyes (compared to anonymous inline lambdas) when passing a non-trivial function as a parameter to another function. Note: don't forget the semicolon after the closing curly brace.

auto algorithm = [&]( double x, double m, double b ) -> double
   {
   return m*x+b;
   };

int a=algorithm(1,2,3), b=algorithm(4,5,6);

If subsequent profiling reveals significant initialization overhead for the function object, you might choose to rewrite this as a normal function.

How to get jQuery dropdown value onchange event

 
$('#drop').change(
    function() {
        var val1 = $('#pick option:selected').val();
        var val2 = $('#drop option:selected').val();

        // Do something with val1 and val2 ...
    }
);

how to make a specific text on TextView BOLD

While you can use Html.fromHtml() you can use a more native approach which is SpannableStringBuilder , this post may be helful.

SpannableStringBuilder str = new SpannableStringBuilder("Your awesome text");
str.setSpan(new android.text.style.StyleSpan(android.graphics.Typeface.BOLD), INT_START, INT_END, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
TextView tv=new TextView(context);
tv.setText(str);

Concatenating elements in an array to a string

Arrays.toString is formatting the output (added the brackets and commas). you should implement your own method of toString.

public String toString(String[] arr){
    String result = "";
    for(String s : arr)
        result+=s;
    return result;
}

[edit] Stringbuilder is better though. see above.

Strange out of memory issue while loading an image to a Bitmap object

After looking through all the answers, I was surprised to see that no one mentioned the Glide API for handling images. Great library, and abstracts out all the complexity of bitmap management. You can load and resize images quickly with this library and a single line of code.

     Glide.with(this).load(yourImageResource).into(imageview);

You can get the repository here: https://github.com/bumptech/glide

PHP Composer behind http proxy

If you're on Linux or Unix (including OS X), you should put this somewhere that will affect your environment:

export HTTP_PROXY_REQUEST_FULLURI=0 # or false
export HTTPS_PROXY_REQUEST_FULLURI=0 #

You can put it in /etc/profile to globally affect all users on the machine, or your own ~/.bashrc or ~/.zshrc, depending on which shell you use.

If you're on Windows, open the Environment Variables control panel, and add either a system or user environment variables with both HTTP_PROXY_REQUEST_FULLURI and HTTPS_PROXY_REQUEST_FULLURI set to 0 or false.

For other people reading this (not you, since you said you have these set up), make sure HTTP_PROXY and HTTPS_PROXY are set to the correct proxy, using the same methods. If you're on Unix/Linux/OS X, setting both upper and lowercase versions of the variable name is the most complete approach, as some things use only the lowercase version, and IIRC some use the upper case. (I'm often using a sort of hybrid environment, Cygwin on Windows, and I know for me it was important to have both, but pure Unix/Linux environments might be able to get away with just lowercase.)

If you still can't get things working after you've done all this, and you're sure you have the correct proxy address set, then look into whether your company is using a Microsoft proxy server. If so, you probably need to install Cntlm as a child proxy to connect between Composer (etc.) and the Microsoft proxy server. Google CNTLM for more information and directions on how to set it up.

Sending HTML Code Through JSON

All string data must be UTF-8 encoded. 

$out = array(
   'render' => utf8_encode($renderOutput), 
   'text' => utf8_encode($textOutput)
);

$out = json_encode($out);
die($out);

Create an application setup in visual studio 2013

I will tell , how i solved almost similar problem. I developed a application using VS 2013 and tried to create wizard for it failed to do. Later i installed premium VS and tried and failed.

at last i used "ClickOnce" and it worked fine.

So i believe here also , "CLICKONCE" would help you.

How do I fix PyDev "Undefined variable from import" errors?

For code in your project, the only way is adding a declaration saying that you expected that -- possibly protected by an if False so that it doesn't execute (the static code-analysis only sees what you see, not runtime info -- if you opened that module yourself, you'd have no indication that main was expected).

To overcome this there are some choices:

  1. If it is some external module, it's possible to add it to the forced builtins so that PyDev spawns a shell for it to obtain runtime information (see http://pydev.org/manual_101_interpreter.html for details) -- i.e.: mostly, PyDev will import the module in a shell and do a dir(module) and dir on the classes found in the module to present completions and make code analysis.

  2. You can use Ctrl+1 (Cmd+1 for Mac) in a line with an error and PyDev will present you an option to add a comment to ignore that error.

  3. It's possible to create a stub module and add it to the predefined completions (http://pydev.org/manual_101_interpreter.html also has details on that).

Difference Between $.getJSON() and $.ajax() in jQuery

.getJson is simply a wrapper around .ajax but it provides a simpler method signature as some of the settings are defaulted e.g dataType to json, type to get etc

N.B .load, .get and .post are also simple wrappers around the .ajax method.

How can I remount my Android/system as read-write in a bash script using adb?

Otherwise... if

getenforce

returns

Enforcing

Then maybe you should call

setenforce 0 
mount -o rw,remount /system 
setenforce 1

General error: 1364 Field 'user_id' doesn't have a default value

 
 Post::create([
      'title' => request('title'),
      'body' => request('body'),
      'user_id' => auth()->id()
    ]);

you dont need the request() as you doing that already pulling the value of body and title

iPhone UILabel text soft shadow

Subclass UILabel, as stated, then, in drawRect:, do [self drawTextInRect:rect]; to get the text drawn into the current context. Once it is in there, you can start working with it by adding filters and whatnot. If you want to make a drop shadow with what you just drew into the context, you should be able to use:

CGContextSetShadowWithColor()

Look that function up in the docs to learn how to use it.

How are ssl certificates verified?

I KNOW THE BELOW IS LONG, BUT IT IS DETAILED, YET SIMPLIFIED ENOUGH. READ CAREFULLY AND I GUARANTEE YOU'LL START FINDING THIS TOPIC IS NOT ALL THAT COMPLICATED.

First of all, anyone can create 2 keys. One to encrypt data, and another to decrypt data. The former can be a private key, and the latter a public key, AND VICERZA.

Second of all, in simplest terms, a Certificate Authority (CA) offers the service of creating a certificate for you. How? They use certain values (the CA's issuer name, your server's public key, company name, domain, etc.) and they use their SUPER DUPER ULTRA SECURE SECRET private key and encrypt this data. The result of this encrypted data is a SIGNATURE.

So now the CA gives you back a certificate. The certificate is basically a file containing the values previously mentioned (CA's issuer name, company name, domain, your server's public key, etc.), INCLUDING the signature (i.e. an encrypted version of the latter values).

Now, with all that being said, here is a REALLY IMPORTANT part to remember: your device/OS (Windows, Android, etc.) pretty much keeps a list of all major/trusted CA's and their PUBLIC KEYS (if you're thinking that these public keys are used to decrypt the signatures inside the certificates, YOU ARE CORRECT!).

Ok, if you read the above, this sequential example will be a breeze now:

  1. Example-Company asks Example-CA to create for them a certificate.
  2. Example-CA uses their super private key to sign this certificate and gives Example-Company the certificate.
  3. Tomorrow, internet-user-Bob uses Chrome/Firefox/etc. to browse to https://example-company.com. Most, if not all, browsers nowadays will expect a certificate back from the server.
  4. The browser gets the certificate from example-company.com. The certificate says it's been issued by Example-CA. It just so happens to be that Bob's OS already has Example-CA in its list of trusted CA's, so the browser gets Example-CA's public key. Remember: this is all happening in Bob's computer/mobile/etc., not over the wire.
  5. So now the browser decrypts the signature in the certificate. FINALLY, the browser compares the decrypted values with the contents of the certificate itself. IF THE CONTENTS MATCH, THAT MEANS THE SIGNATURE IS VALID!

Why? Think about it, only this public key can decrypt the signature in such a way that the contents look like they did before the private key encrypted them.

How about man in the middle attacks?

This is one of the main reasons (if not the main reason) why the above standard was created.

Let's say hacker-Jane intercepts internet-user-Bob's request, and replies with her own certificate. However, hacker-Jane is still careful enough to state in the certificate that the issuer was Example-CA. Lastly, hacker-Jane remembers that she has to include a signature on the certificate. But what key does Jane use to sign (i.e. create an encrypted value of the certificate main contents) the certificate?????

So even if hacker-Jane signed the certificate with her own key, you see what's gonna happen next. The browser is gonna say: "ok, this certificate is issued by Example-CA, let's decrypt the signature with Example-CA's public key". After decryption, the browser notices that the certificate contents don't match at all. Hence, the browser gives a very clear warning to the user, and it says it doesn't trust the connection.

Can't create handler inside thread that has not called Looper.prepare()

You need to create toast on UI thread. Find the example below.

runOnUiThread(new Runnable() {
  public void run() {
    Toast.makeText(activity, "YOUR_MESSAGE", Toast.LENGTH_SHORT).show();
  }
});

For displaying Toast message please refer to this article

Docker how to change repository name or rename image?

 
docker image tag #imageId myname/server:latest

This works for me

Access nested dictionary items via a list of keys?

It seems more pythonic to use a for loop. See the quote from What’s New In Python 3.0.

Removed reduce(). Use functools.reduce() if you really need it; however, 99 percent of the time an explicit for loop is more readable.

def nested_get(dic, keys):    
    for key in keys:
        dic = dic[key]
    return dic

Note that the accepted solution doesn't set non-existing nested keys (it raises KeyError). Using the approach below will create non-existing nodes instead:

def nested_set(dic, keys, value):
    for key in keys[:-1]:
        dic = dic.setdefault(key, {})
    dic[keys[-1]] = value

The code works in both Python 2 and 3.

What causes an HTTP 405 "invalid method (HTTP verb)" error when POSTing a form to PHP on IIS?

As drewm himself said this is due to the subsequent redirect after the POST to the script has in fact succeeded. (I might have added this as a comment to his answer but you need 50 reputation to comment and I'm new round here - daft rule IMHO)

BUT it also applies if you're trying to redirect to a page, not just a directory - at least it did for me. I was trying to redirect to /thankyou.html. What fixes this is using an absolute URL, i.e. http://example.com/thankyou.html

Route.get() requires callback functions but got a "object Undefined"

There are two routes for get:

app.get('/', main.index);
todoRouter.get('/',todo.all);

Error: Route.get() requires callback functions but got a [object Undefined] This exception is thrown when route.getdoes not get a callback function. As you have defined todo.all in todo.js file, but it is unable to find main.index. That's why it works once you define main.index file later on in the tutorial.

pythonic way to do something N times without an index variable?

Assume that you've defined do_something as a function, and you'd like to perform it N times. Maybe you can try the following:

todos = [do_something] * N  
for doit in todos:  
    doit()

How to use JNDI DataSource provided by Tomcat in Spring?

With Spring's JavaConfig mechanism, you can do it like so:

@Configuration
public class MainConfig {

    ...

    @Bean
    DataSource dataSource() {
        DataSource dataSource = null;
        JndiTemplate jndi = new JndiTemplate();
        try {
            dataSource = jndi.lookup("java:comp/env/jdbc/yourname", DataSource.class);
        } catch (NamingException e) {
            logger.error("NamingException for java:comp/env/jdbc/yourname", e);
        }
        return dataSource;
    }

}

How do I prevent site scraping?

Method One (Small Sites Only):
Serve encrypted / encoded data.
I Scape the web using python (urllib, requests, beautifulSoup etc...) and found many websites that serve encrypted / encoded data that is not decrypt-able in any programming language simply because the encryption method does not exist.

I achieved this in a PHP website by encrypting and minimizing the output (WARNING: this is not a good idea for large sites) the response was always jumbled content.

Example of minimizing output in PHP (How to minify php page html output?):

<?php
  function sanitize_output($buffer) {
    $search = array(
      '/\>[^\S ]+/s', // strip whitespaces after tags, except space
      '/[^\S ]+\</s', // strip whitespaces before tags, except space
      '/(\s)+/s'      // shorten multiple whitespace sequences
    );
    $replace = array('>', '<', '\\1');
    $buffer = preg_replace($search, $replace, $buffer);
    return $buffer;
  }
  ob_start("sanitize_output");
?>

Method Two:
If you can't stop them screw them over serve fake / useless data as a response.

Method Three:
block common scraping user agents, you'll see this in major / large websites as it is impossible to scrape them with "python3.4" as you User-Agent.

Method Four:
Make sure all the user headers are valid, I sometimes provide as many headers as possible to make my scraper seem like an authentic user, some of them are not even true or valid like en-FU :).
Here is a list of some of the headers I commonly provide.

headers = {
  "Requested-URI": "/example",
  "Request-Method": "GET",
  "Remote-IP-Address": "656.787.909.121",
  "Remote-IP-Port": "69696",
  "Protocol-version": "HTTP/1.1",
  "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
  "Accept-Encoding": "gzip,deflate",
  "Accept-Language": "en-FU,en;q=0.8",
  "Cache-Control": "max-age=0",
  "Connection": "keep-alive",
  "Dnt": "1",  
  "Host": "http://example.com",
  "Referer": "http://example.com",
  "Upgrade-Insecure-Requests": "1",
  "User-Agent": "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/47.0.2526.111 Safari/537.36"
}

Plotting two variables as lines using ggplot2 on the same graph

For a small number of variables, you can build the plot manually yourself:

ggplot(test_data, aes(date)) + 
  geom_line(aes(y = var0, colour = "var0")) + 
  geom_line(aes(y = var1, colour = "var1"))

How to get margin value of a div in plain JavaScript?

Also, you can create your own outerHeight for HTML elements. I don't know if it works in IE, but it works in Chrome. Perhaps, you can enhance the code below using currentStyle, suggested in the answer above. 

Object.defineProperty(Element.prototype, 'outerHeight', {
    'get': function(){
        var height = this.clientHeight;
        var computedStyle = window.getComputedStyle(this); 
        height += parseInt(computedStyle.marginTop, 10);
        height += parseInt(computedStyle.marginBottom, 10);
        height += parseInt(computedStyle.borderTopWidth, 10);
        height += parseInt(computedStyle.borderBottomWidth, 10);
        return height;
    }
});

This piece of code allow you to do something like this:

document.getElementById('foo').outerHeight

According to caniuse.com, getComputedStyle is supported by main browsers (IE, Chrome, Firefox).

How to list all files in a directory and its subdirectories in hadoop hdfs

Now, one can use Spark to do the same and its way faster than other approaches (such as Hadoop MR). Here is the code snippet.

def traverseDirectory(filePath:String,recursiveTraverse:Boolean,filePaths:ListBuffer[String]) {
    val files = FileSystem.get( sparkContext.hadoopConfiguration ).listStatus(new Path(filePath))
            files.foreach { fileStatus => {
                if(!fileStatus.isDirectory() && fileStatus.getPath().getName().endsWith(".xml")) {                
                    filePaths+=fileStatus.getPath().toString()      
                }
                else if(fileStatus.isDirectory()) {
                    traverseDirectory(fileStatus.getPath().toString(), recursiveTraverse, filePaths)
                }
            }
    }   
}

How to run a shell script on a Unix console or Mac terminal?

First, give permission for execution:-
chmod +x script_name

  1. If script is not executable:-
    For running sh script file:-
    sh script_name
    For running bash script file:-
    bash script_name
  2. If script is executable:-
    ./script_name

NOTE:-you can check if the file is executable or not by using 'ls -a'

Zero-pad digits in string

There's also str_pad

<?php
$input = "Alien";
echo str_pad($input, 10);                      // produces "Alien     "
echo str_pad($input, 10, "-=", STR_PAD_LEFT);  // produces "-=-=-Alien"
echo str_pad($input, 10, "_", STR_PAD_BOTH);   // produces "__Alien___"
echo str_pad($input, 6 , "___");               // produces "Alien_"
?>

Fill formula down till last row in column

Alternatively, you may use FillDown

Range("M3") = "=G3&"",""&L3": Range("M3:M" & LastRow).FillDown

"google is not defined" when using Google Maps V3 in Firefox remotely

try this:

<script src="https://maps.googleapis.com/maps/api/js"></script>

it works for me... the point is, change HTTP to HTTPS

Changing SQL Server collation to case insensitive from case sensitive?

You basically need to run the installation again to rebuild the master database with the new collation. You cannot change the entire server's collation any other way.

See:

Update: if you want to change the collation of a database, you can get the current collation using this snippet of T-SQL:

SELECT name, collation_name 
FROM sys.databases
WHERE name = 'test2'   -- put your database name here

This will yield a value something like:

Latin1_General_CI_AS

The _CI means "case insensitive" - if you want case-sensitive, use _CS in its place:

Latin1_General_CS_AS

So your T-SQL command would be:

ALTER DATABASE test2 -- put your database name here
   COLLATE Latin1_General_CS_AS   -- replace with whatever collation you need

You can get a list of all available collations on the server using:

SELECT * FROM ::fn_helpcollations()

You can see the server's current collation using:

SELECT SERVERPROPERTY ('Collation')

Check if an object exists

If the user exists you can get the user in user_object else user_object will be None.

try:
    user_object = User.objects.get(email = cleaned_info['username'])
except User.DoesNotExist:
    user_object = None
if user_object:
    # user exist
    pass
else:
    # user does not exist
    pass

jQuery callback on image load (even when the image is cached)

You can also use this code with support for loading error:

$("img").on('load', function() {
  // do stuff on success
})
.on('error', function() {
  // do stuff on smth wrong (error 404, etc.)
})
.each(function() {
    if(this.complete) {
      $(this).load();
    } else if(this.error) {
      $(this).error();
    }
});

find difference between two text files with one item per line

With GNU sed:

sed 's#[^^]#[&]#g;s#\^#\\^#g;s#^#/^#;s#$#$/d#' file1 | sed -f- file2

How it works:

The first sed produces an output like this:

/^[d][s][f]$/d
/^[s][d][f][s][d]$/d
/^[d][s][f][s][d][f]$/d

Then it is used as a sed script by the second sed.

How to create nonexistent subdirectories recursively using Bash?

You can use the -p parameter, which is documented as:

-p, --parents

no error if existing, make parent directories as needed

So:

mkdir -p "$BACKUP_DIR/$client/$year/$month/$day"

Link entire table row?

To link the entire row, you need to define onclick function on your row, which is <tr>element and define a mouse hover in the CSS for tr element to make the mouse pointer to a typical click-hand in web:

In table:

<tr onclick="location.href='http://www.google.com'">
<td>blah</td>
<td>blah</td>
<td><strong>Text</strong></td>
</tr>

In related CSS:

tr:hover {
cursor: pointer;
}

Is it possible to dynamically compile and execute C# code fragments?

The best solution in C#/all static .NET languages is to use the CodeDOM for such things. (As a note, its other main purpose is for dynamically constructing bits of code, or even whole classes.)

Here's a nice short example take from LukeH's blog, which uses some LINQ too just for fun.

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.CSharp;
using System.CodeDom.Compiler;

class Program
{
    static void Main(string[] args)
    {
        var csc = new CSharpCodeProvider(new Dictionary<string, string>() { { "CompilerVersion", "v3.5" } });
        var parameters = new CompilerParameters(new[] { "mscorlib.dll", "System.Core.dll" }, "foo.exe", true);
        parameters.GenerateExecutable = true;
        CompilerResults results = csc.CompileAssemblyFromSource(parameters,
        @"using System.Linq;
            class Program {
              public static void Main(string[] args) {
                var q = from i in Enumerable.Range(1,100)
                          where i % 2 == 0
                          select i;
              }
            }");
        results.Errors.Cast<CompilerError>().ToList().ForEach(error => Console.WriteLine(error.ErrorText));
    }
}

The class of primary importance here is the CSharpCodeProvider which utilises the compiler to compile code on the fly. If you want to then run the code, you just need to use a bit of reflection to dynamically load the assembly and execute it.

Here is another example in C# that (although slightly less concise) additionally shows you precisely how to run the runtime-compiled code using the System.Reflection namespace.

Toggle visibility property of div

Using jQuery:

$('#play-pause').click(function(){
  if ( $('#video-over').css('visibility') == 'hidden' )
    $('#video-over').css('visibility','visible');
  else
    $('#video-over').css('visibility','hidden');
});

Is it necessary to write HEAD, BODY and HTML tags?

Omitting the html, head, and body tags is certainly allowed by the HTML specs. The underlying reason is that browsers have always sought to be consistent with existing web pages, and the very early versions of HTML didn't define those elements. When HTML 2.0 first did, it was done in a way that the tags would be inferred when missing.

I often find it convenient to omit the tags when prototyping and especially when writing test cases as it helps keep the mark-up focused on the test in question. The inference process should create the elements in exactly the manner that you see in Firebug, and browsers are pretty consistent in doing that.

But...

IE has at least one known bug in this area. Even IE9 exhibits this. Suppose the markup is this:

<!DOCTYPE html>
<title>Test case</title>
<form action='#'>
   <input name="var1">
</form>

You should (and do in other browsers) get a DOM that looks like this:

HTML
    HEAD
        TITLE
    BODY
        FORM action="#"
            INPUT name="var1"

But in IE you get this:

HTML
    HEAD
       TITLE
       FORM action="#"
           BODY
               INPUT name="var1"
    BODY

See it for yourself.

This bug seems limited to the form start tag preceding any text content and any body start tag.

How to get all key in JSON object (javascript)

 
var input = {"document":
  {"people":[
    {"name":["Harry Potter"],"age":["18"],"gender":["Male"]},
    {"name":["hermione granger"],"age":["18"],"gender":["Female"]},
  ]}
}

var keys = [];
for(var i = 0;i<input.document.people.length;i++)
{
    Object.keys(input.document.people[i]).forEach(function(key){
        if(keys.indexOf(key) == -1)
        {
            keys.push(key);
        }
    });
}
console.log(keys);

getFilesDir() vs Environment.getDataDirectory()

Try this

getExternalFilesDir(Environment.getDataDirectory().getAbsolutePath()).getAbsolutePath()

MySQL count occurrences greater than 2

SELECT word, COUNT(*) FROM words GROUP by word HAVING COUNT(*) > 1

How to implement a binary search tree in Python?

The accepted answer neglects to set a parent attribute for each node inserted, without which one cannot implement a successor method which finds the successor in an in-order tree walk in O(h) time, where h is the height of the tree (as opposed to the O(n) time needed for the walk).

Here is an implementation based on the pseudocode given in Cormen et al., Introduction to Algorithms, including assignment of a parent attribute and a successor method:

class Node(object):
    def __init__(self, key):
        self.key = key
        self.left = None
        self.right = None
        self.parent = None


class Tree(object):
    def __init__(self, root=None):
        self.root = root

    def insert(self, z):
        y = None
        x = self.root
        while x is not None:
            y = x
            if z.key < x.key:
                x = x.left
            else:
                x = x.right
        z.parent = y
        if y is None:
            self.root = z       # Tree was empty
        elif z.key < y.key:
            y.left = z
        else:
            y.right = z

    @staticmethod
    def minimum(x):
        while x.left is not None:
            x = x.left
        return x

    @staticmethod
    def successor(x):
        if x.right is not None:
            return Tree.minimum(x.right)
        y = x.parent
        while y is not None and x == y.right:
            x = y
            y = y.parent
        return y

Here are some tests to show that the tree behaves as expected for the example given by DTing:

import pytest

@pytest.fixture
def tree():
    t = Tree()
    t.insert(Node(3))
    t.insert(Node(1))
    t.insert(Node(7))
    t.insert(Node(5))
    return t

def test_tree_insert(tree):
    assert tree.root.key == 3
    assert tree.root.left.key == 1
    assert tree.root.right.key == 7
    assert tree.root.right.left.key == 5

def test_tree_successor(tree):
    assert Tree.successor(tree.root.left).key == 3
    assert Tree.successor(tree.root.right.left).key == 7

if __name__ == "__main__":
    pytest.main([__file__])

MS-DOS Batch file pause with enter key

There's a pause command that does just that, though it's not specifically the enter key.

If you really want to wait for only the enter key, you can use the set command to ask for user input with a dummy variable, something like:

set /p DUMMY=Hit ENTER to continue...

HTTP Get with 204 No Content: Is that normal

I use GET/204 with a RESTful collection that is a positional array of known fixed length but with holes. 

GET /items
    200: ["a", "b", null]

GET /items/0
    200: "a"

GET /items/1
    200: "b"

GET /items/2
    204:

GET /items/3
    404: Not Found

Reading a file line by line in Go

In the new version of Go 1.16 we can use package embed to read the file contents as shown below.

package main

import _"embed"


func main() {
    //go:embed "hello.txt"
    var s string
    print(s)

    //go:embed "hello.txt"
    var b []byte
    print(string(b))

    //go:embed hello.txt
    var f embed.FS
    data, _ := f.ReadFile("hello.txt")
    print(string(data))
}

For more details go through https://tip.golang.org/pkg/embed/ And https://golangtutorial.dev/tips/embed-files-in-go/

What does servletcontext.getRealPath("/") mean and when should I use it

There is also a change between Java 7 and Java 8. Admittedly it involves the a deprecated call, but I had to add a "/" to get our program working! Here is the link discussing it Why does servletContext.getRealPath returns null on tomcat 8?

SQL Server Management Studio, how to get execution time down to milliseconds

What you want to do is this:

set statistics time on

-- your query

set statistics time off

That will have the output looking something like this in your Messages window:

SQL Server Execution Times: CPU time = 6 ms, elapsed time = 6 ms.

Manually Set Value for FormBuilder Control

In Angular 2 Final (RC5+) there are new APIs for updating form values. The patchValue() API method supports partial form updates, where we only need to specify some of the fields:

this.form.patchValue({id: selected.id})

There is also the setValue() API method that needs an object with all the form fields. If there is a field missing, we will get an error.

Virtual member call in a constructor

Because until the constructor has completed executing, the object is not fully instantiated. Any members referenced by the virtual function may not be initialised. In C++, when you are in a constructor, this only refers to the static type of the constructor you are in, and not the actual dynamic type of the object that is being created. This means that the virtual function call might not even go where you expect it to.

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

It would help to have sample information about your output. Recursively using rbind on bigger and bigger things is not recommended. My first guess at something that would help you:

z <- list(1:3,4:6,7:9)
do.call(rbind,z)

See a related question for more efficiency, if needed.

php/mySQL on XAMPP: password for phpMyAdmin and mysql_connect different?

You need to change the password directly in the database because at mysql the users and their profiles are saved in the database.

So there are several ways. At phpMyAdmin you simple go to user admin, choose root and change the password.

Generate random integers between 0 and 9

random.sample is another that can be used

import random
n = 1 # specify the no. of numbers
num = random.sample(range(10),  n)
num[0] # is the required number

C# elegant way to check if a property's property is null

You're obviously looking for the Nullable Monad:

string result = new A().PropertyB.PropertyC.Value;

becomes

string result = from a in new A()
                from b in a.PropertyB
                from c in b.PropertyC
                select c.Value;

This returns null, if any of the nullable properties are null; otherwise, the value of Value.

class A { public B PropertyB { get; set; } }
class B { public C PropertyC { get; set; } }
class C { public string Value { get; set; } }

LINQ extension methods:

public static class NullableExtensions
{
    public static TResult SelectMany<TOuter, TInner, TResult>(
        this TOuter source,
        Func<TOuter, TInner> innerSelector,
        Func<TOuter, TInner, TResult> resultSelector)
        where TOuter : class
        where TInner : class
        where TResult : class
    {
        if (source == null) return null;
        TInner inner = innerSelector(source);
        if (inner == null) return null;
        return resultSelector(source, inner);
    }
}

Sleep Command in T-SQL?

 
WAITFOR DELAY 'HH:MM:SS'

I believe the maximum time this can wait for is 23 hours, 59 minutes and 59 seconds.

Here's a Scalar-valued function to show it's use; the below function will take an integer parameter of seconds, which it then translates into HH:MM:SS and executes it using the EXEC sp_executesql @sqlcode command to query. Below function is for demonstration only, i know it's not fit for purpose really as a scalar-valued function! :-)

    CREATE FUNCTION [dbo].[ufn_DelayFor_MaxTimeIs24Hours]
    (
    @sec int
    )
    RETURNS
    nvarchar(4)
    AS
    BEGIN


    declare @hours int = @sec / 60 / 60
    declare @mins int = (@sec / 60) - (@hours * 60)
    declare @secs int = (@sec - ((@hours * 60) * 60)) - (@mins * 60)


    IF @hours > 23 
    BEGIN
    select @hours = 23
    select @mins = 59
    select @secs = 59
    -- 'maximum wait time is 23 hours, 59 minutes and 59 seconds.'
    END


    declare @sql nvarchar(24) = 'WAITFOR DELAY '+char(39)+cast(@hours as nvarchar(2))+':'+CAST(@mins as nvarchar(2))+':'+CAST(@secs as nvarchar(2))+char(39)


    exec sp_executesql @sql

    return ''
    END

IF you wish to delay longer than 24 hours, I suggest you use a @Days parameter to go for a number of days and wrap the function executable inside a loop... e.g..

    Declare @Days int = 5
    Declare @CurrentDay int = 1

    WHILE @CurrentDay <= @Days
    BEGIN

    --24 hours, function will run for 23 hours, 59 minutes, 59 seconds per run.
    [ufn_DelayFor_MaxTimeIs24Hours] 86400

    SELECT @CurrentDay = @CurrentDay + 1
    END

How to display loading image while actual image is downloading

Instead of just doing this quoted method from https://stackoverflow.com/a/4635440/3787376,

You can do something like this:

// show loading image
$('#loader_img').show();

// main image loaded ?
$('#main_img').on('load', function(){
  // hide/remove the loading image
  $('#loader_img').hide();
});

You assign load event to the image which fires when image has finished loading. Before that, you can show your loader image.

you can use a different jQuery function to make the loading image fade away, then be hidden:

// Show the loading image.
$('#loader_img').show();

// When main image loads:
$('#main_img').on('load', function(){
  // Fade out and hide the loading image.
  $('#loader_img').fadeOut(100); // Time in milliseconds.
});

"Once the opacity reaches 0, the display style property is set to none." http://api.jquery.com/fadeOut/

Or you could not use the jQuery library because there are already simple cross-browser JavaScript methods.

Disable Drag and Drop on HTML elements?

Try preventing default on mousedown event:

<div onmousedown="event.preventDefault ? event.preventDefault() : event.returnValue = false">asd</div>

or

<div onmousedown="return false">asd</div>

jQuery.parseJSON throws “Invalid JSON” error due to escaped single quote in JSON

Striking a similar issue using CakePHP to output a JavaScript script-block using PHP's native json_encode. $contractorCompanies contains values that have single quotation marks and as explained above and expected json_encode($contractorCompanies) doesn't escape them because its valid JSON.

<?php $this->Html->scriptBlock("var contractorCompanies = jQuery.parseJSON( '".(json_encode($contractorCompanies)."' );"); ?>

By adding addslashes() around the JSON encoded string you then escape the quotation marks allowing Cake / PHP to echo the correct javascript to the browser. JS errors disappear.

<?php $this->Html->scriptBlock("var contractorCompanies = jQuery.parseJSON( '".addslashes(json_encode($contractorCompanies))."' );"); ?>

Cannot create SSPI context

I just had the same problem and all I did was delete the user log in credentials in sql server using another user id and adding them back.

Bash Templating: How to build configuration files from templates with Bash?

To follow up on plockc's answer on this page, here is a dash-suitable version, for those of you looking to avoid bashisms.

eval "cat <<EOF >outputfile
$( cat template.in )
EOF
" 2> /dev/null

Getting IPV4 address from a sockaddr structure

Just cast the entire sockaddr structure to a sockaddr_in. Then you can use:

char *ip = inet_ntoa(their_addr.sin_addr)

To retrieve the standard ip representation.

Select specific row from mysql table

You can add an auto generated id field in the table and select by this id

SELECT * FROM CUSTOMER WHERE CUSTOMER_ID = 3;

C error: Expected expression before int

{ } -->

defines scope, so if(a==1) { int b = 10; } says, you are defining int b, for {}- this scope. For 

if(a==1)
  int b =10;

there is no scope. And you will not be able to use b anywhere.

How to access the first property of a Javascript object?

if someone prefers array destructuring

const [firstKey] = Object.keys(object);

C# with MySQL INSERT parameters

Three things: use the using statement, use AddWithValue and prefix parameters with ? and add Allow User Variables=True to the connection string.

 string connString = ConfigurationManager.ConnectionStrings["default"].ConnectionString;
 using (var conn = new MySqlConnection(connString))
 {
      conn.Open();
      var comm = conn.CreateCommand();
      comm.CommandText = "INSERT INTO room(person,address) VALUES(@person, @address)";
      comm.Parameters.AddWithValue("?person", "Myname");
      comm.Parameters.AddWithValue("?address", "Myaddress");
      comm.ExecuteNonQuery();
  }

Also see http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlcommand.parameters.aspx for more information about the command usage, and http://dev.mysql.com/doc/refman/5.1/en/connector-net-connection-options.html for information about the Allow User Variables option (only supported in version 5.2.2 and above).

Declaring variables inside or outside of a loop

Please skip to the updated answer...

For those who care about performance take out the System.out and limit the loop to 1 byte. Using double (test 1/2) and using String (3/4) the elapsed times in milliseconds is given below with Windows 7 Professional 64 bit and JDK-1.7.0_21. Bytecodes (also given below for test1 and test2) are not the same. I was too lazy to test with mutable & relatively complex objects.

double

Test1 took: 2710 msecs

Test2 took: 2790 msecs

String (just replace double with string in the tests)

Test3 took: 1200 msecs

Test4 took: 3000 msecs

Compiling and getting bytecode

javac.exe LocalTest1.java

javap.exe -c LocalTest1 > LocalTest1.bc


public class LocalTest1 {

    public static void main(String[] args) throws Exception {
        long start = System.currentTimeMillis();
        double test;
        for (double i = 0; i < 1000000000; i++) {
            test = i;
        }
        long finish = System.currentTimeMillis();
        System.out.println("Test1 Took: " + (finish - start) + " msecs");
    }

}

public class LocalTest2 {

    public static void main(String[] args) throws Exception {
        long start = System.currentTimeMillis();
        for (double i = 0; i < 1000000000; i++) {
            double test = i;
        }
        long finish = System.currentTimeMillis();
        System.out.println("Test1 Took: " + (finish - start) + " msecs");
    }
}


Compiled from "LocalTest1.java"
public class LocalTest1 {
  public LocalTest1();
    Code:
       0: aload_0
       1: invokespecial #1                  // Method java/lang/Object."<init>":()V
       4: return

  public static void main(java.lang.String[]) throws java.lang.Exception;
    Code:
       0: invokestatic  #2                  // Method java/lang/System.currentTimeMillis:()J
       3: lstore_1
       4: dconst_0
       5: dstore        5
       7: dload         5
       9: ldc2_w        #3                  // double 1.0E9d
      12: dcmpg
      13: ifge          28
      16: dload         5
      18: dstore_3
      19: dload         5
      21: dconst_1
      22: dadd
      23: dstore        5
      25: goto          7
      28: invokestatic  #2                  // Method java/lang/System.currentTimeMillis:()J
      31: lstore        5
      33: getstatic     #5                  // Field java/lang/System.out:Ljava/io/PrintStream;
      36: new           #6                  // class java/lang/StringBuilder
      39: dup
      40: invokespecial #7                  // Method java/lang/StringBuilder."<init>":()V
      43: ldc           #8                  // String Test1 Took:
      45: invokevirtual #9                  // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
      48: lload         5
      50: lload_1
      51: lsub
      52: invokevirtual #10                 // Method java/lang/StringBuilder.append:(J)Ljava/lang/StringBuilder;
      55: ldc           #11                 // String  msecs
      57: invokevirtual #9                  // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
      60: invokevirtual #12                 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
      63: invokevirtual #13                 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
      66: return
}


Compiled from "LocalTest2.java"
public class LocalTest2 {
  public LocalTest2();
    Code:
       0: aload_0
       1: invokespecial #1                  // Method java/lang/Object."<init>":()V
       4: return

  public static void main(java.lang.String[]) throws java.lang.Exception;
    Code:
       0: invokestatic  #2                  // Method java/lang/System.currentTimeMillis:()J
       3: lstore_1
       4: dconst_0
       5: dstore_3
       6: dload_3
       7: ldc2_w        #3                  // double 1.0E9d
      10: dcmpg
      11: ifge          24
      14: dload_3
      15: dstore        5
      17: dload_3
      18: dconst_1
      19: dadd
      20: dstore_3
      21: goto          6
      24: invokestatic  #2                  // Method java/lang/System.currentTimeMillis:()J
      27: lstore_3
      28: getstatic     #5                  // Field java/lang/System.out:Ljava/io/PrintStream;
      31: new           #6                  // class java/lang/StringBuilder
      34: dup
      35: invokespecial #7                  // Method java/lang/StringBuilder."<init>":()V
      38: ldc           #8                  // String Test1 Took:
      40: invokevirtual #9                  // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
      43: lload_3
      44: lload_1
      45: lsub
      46: invokevirtual #10                 // Method java/lang/StringBuilder.append:(J)Ljava/lang/StringBuilder;
      49: ldc           #11                 // String  msecs
      51: invokevirtual #9                  // Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
      54: invokevirtual #12                 // Method java/lang/StringBuilder.toString:()Ljava/lang/String;
      57: invokevirtual #13                 // Method java/io/PrintStream.println:(Ljava/lang/String;)V
      60: return
}

UPDATED ANSWER

It's really not easy to compare performance with all the JVM optimizations. However, it is somewhat possible. Better test and detailed results in Google Caliper

  1. Some details on blog:Should you declare a variable inside a loop or before the loop?
  2. GitHub repository: https://github.com/gunduru/jvdt
  3. Test Results for double case and 100M loop (and yes all JVM details): https://microbenchmarks.appspot.com/runs/b1cef8d1-0e2c-4120-be61-a99faff625b4

DeclaredBefore 1,759.209 DeclaredInside 2,242.308

  • DeclaredBefore 1,759.209 ns
  • DeclaredInside 2,242.308 ns

Partial Test Code for double Declaration

This is not identical to the code above. If you just code a dummy loop JVM skips it, so at least you need to assign and return something. This is also recommended in Caliper documentation.

@Param int size; // Set automatically by framework, provided in the Main
/**
* Variable is declared inside the loop.
*
* @param reps
* @return
*/
public double timeDeclaredInside(int reps) {
    /* Dummy variable needed to workaround smart JVM */
    double dummy = 0;

    /* Test loop */
    for (double i = 0; i <= size; i++) {

        /* Declaration and assignment */
        double test = i;

        /* Dummy assignment to fake JVM */
        if(i == size) {
            dummy = test;
        }
    }
    return dummy;
}

/**
* Variable is declared before the loop.
*
* @param reps
* @return
*/
public double timeDeclaredBefore(int reps) {

    /* Dummy variable needed to workaround smart JVM */
    double dummy = 0;

    /* Actual test variable */
    double test = 0;

    /* Test loop */
    for (double i = 0; i <= size; i++) {

        /* Assignment */
        test = i;

        /* Not actually needed here, but we need consistent performance results */
        if(i == size) {
            dummy = test;
        }
    }
    return dummy;
}

Summary: declaredBefore indicates better performance -really tiny- and it's against the smallest scope principle. JVM should actually do this for you

Pure CSS multi-level drop-down menu

Here are a couple good sites to check out for that,

http://www.tripwiremagazine.com/2011/10/css-menu-and-navigation.html (Lots of examples)

http://webdesignerwall.com/tutorials/css3-dropdown-menu (1 example more tutorial like)

Hope this is helpful information!

Simple way to compare 2 ArrayLists

This should check if two lists are equal, it does some basic checks first (i.e. nulls and lengths), then sorts and uses the collections.equals method to check if they are equal.

public  boolean equalLists(List<String> a, List<String> b){     
    // Check for sizes and nulls

    if (a == null && b == null) return true;


    if ((a == null && b!= null) || (a != null && b== null) || (a.size() != b.size()))
    {
        return false;
    }

    // Sort and compare the two lists          
    Collections.sort(a);
    Collections.sort(b);      
    return a.equals(b);
}

Oracle 'Partition By' and 'Row_Number' keyword

PARTITION BY segregate sets, this enables you to be able to work(ROW_NUMBER(),COUNT(),SUM(),etc) on related set independently.

In your query, the related set comprised of rows with similar cdt.country_code, cdt.account, cdt.currency. When you partition on those columns and you apply ROW_NUMBER on them. Those other columns on those combination/set will receive sequential number from ROW_NUMBER

But that query is funny, if your partition by some unique data and you put a row_number on it, it will just produce same number. It's like you do an ORDER BY on a partition that is guaranteed to be unique. Example, think of GUID as unique combination of cdt.country_code, cdt.account, cdt.currency

newid() produces GUID, so what shall you expect by this expression? 

select
   hi,ho,
   row_number() over(partition by newid() order by hi,ho)
from tbl;

...Right, all the partitioned(none was partitioned, every row is partitioned in their own row) rows' row_numbers are all set to 1

Basically, you should partition on non-unique columns. ORDER BY on OVER needed the PARTITION BY to have a non-unique combination, otherwise all row_numbers will become 1

An example, this is your data:

create table tbl(hi varchar, ho varchar);

insert into tbl values
('A','X'),
('A','Y'),
('A','Z'),
('B','W'),
('B','W'),
('C','L'),
('C','L');

Then this is analogous to your query:

select
   hi,ho,
   row_number() over(partition by hi,ho order by hi,ho)
from tbl;

What will be the output of that?

HI  HO  COLUMN_2
A   X   1
A   Y   1
A   Z   1
B   W   1
B   W   2
C   L   1
C   L   2

You see thee combination of HI HO? The first three rows has unique combination, hence they are set to 1, the B rows has same W, hence different ROW_NUMBERS, likewise with HI C rows.

Now, why is the ORDER BY needed there? If the previous developer merely want to put a row_number on similar data (e.g. HI B, all data are B-W, B-W), he can just do this:

select
   hi,ho,
   row_number() over(partition by hi,ho)
from tbl;

But alas, Oracle(and Sql Server too) doesn't allow partition with no ORDER BY; whereas in Postgresql, ORDER BY on PARTITION is optional: http://www.sqlfiddle.com/#!1/27821/1

select
   hi,ho,
   row_number() over(partition by hi,ho)
from tbl;

Your ORDER BY on your partition look a bit redundant, not because of the previous developer's fault, some database just don't allow PARTITION with no ORDER BY, he might not able find a good candidate column to sort on. If both PARTITION BY columns and ORDER BY columns are the same just remove the ORDER BY, but since some database don't allow it, you can just do this:

SELECT cdt.*,
        ROW_NUMBER ()
        OVER (PARTITION BY cdt.country_code, cdt.account, cdt.currency
              ORDER BY newid())
           seq_no
   FROM CUSTOMER_DETAILS cdt

You cannot find a good column to use for sorting similar data? You might as well sort on random, the partitioned data have the same values anyway. You can use GUID for example(you use newid() for SQL Server). So that has the same output made by previous developer, it's unfortunate that some database doesn't allow PARTITION with no ORDER BY

Though really, it eludes me and I cannot find a good reason to put a number on the same combinations (B-W, B-W in example above). It's giving the impression of database having redundant data. Somehow reminded me of this: How to get one unique record from the same list of records from table? No Unique constraint in the table

It really looks arcane seeing a PARTITION BY with same combination of columns with ORDER BY, can not easily infer the code's intent.

Live test: http://www.sqlfiddle.com/#!3/27821/6

But as dbaseman have noticed also, it's useless to partition and order on same columns.

You have a set of data like this:

create table tbl(hi varchar, ho varchar);

insert into tbl values
('A','X'),
('A','X'),
('A','X'),
('B','Y'),
('B','Y'),
('C','Z'),
('C','Z');

Then you PARTITION BY hi,ho; and then you ORDER BY hi,ho. There's no sense numbering similar data :-) http://www.sqlfiddle.com/#!3/29ab8/3

select
   hi,ho,
   row_number() over(partition by hi,ho order by hi,ho) as nr
from tbl;

Output:

HI  HO  ROW_QUERY_A
A   X   1
A   X   2
A   X   3
B   Y   1
B   Y   2
C   Z   1
C   Z   2

See? Why need to put row numbers on same combination? What you will analyze on triple A,X, on double B,Y, on double C,Z? :-)

You just need to use PARTITION on non-unique column, then you sort on non-unique column(s)'s unique-ing column. Example will make it more clear:

create table tbl(hi varchar, ho varchar);

insert into tbl values
('A','D'),
('A','E'),
('A','F'),
('B','F'),
('B','E'),
('C','E'),
('C','D');

select
   hi,ho,
   row_number() over(partition by hi order by ho) as nr
from tbl;

PARTITION BY hi operates on non unique column, then on each partitioned column, you order on its unique column(ho), ORDER BY ho

Output:

HI  HO  NR
A   D   1
A   E   2
A   F   3
B   E   1
B   F   2
C   D   1
C   E   2

That data set makes more sense

Live test: http://www.sqlfiddle.com/#!3/d0b44/1

And this is similar to your query with same columns on both PARTITION BY and ORDER BY: 

select
   hi,ho,
   row_number() over(partition by hi,ho order by hi,ho) as nr
from tbl;

And this is the ouput:

HI  HO  NR
A   D   1
A   E   1
A   F   1
B   E   1
B   F   1
C   D   1
C   E   1

See? no sense?

Live test: http://www.sqlfiddle.com/#!3/d0b44/3

Finally this might be the right query:

SELECT cdt.*,
     ROW_NUMBER ()
     OVER (PARTITION BY cdt.country_code, cdt.account -- removed: cdt.currency
           ORDER BY 
               -- removed: cdt.country_code, cdt.account, 
               cdt.currency) -- keep
        seq_no
FROM CUSTOMER_DETAILS cdt

Selecting a Linux I/O Scheduler

As documented in /usr/src/linux/Documentation/block/switching-sched.txt, the I/O scheduler on any particular block device can be changed at runtime. There may be some latency as the previous scheduler's requests are all flushed before bringing the new scheduler into use, but it can be changed without problems even while the device is under heavy use.

# cat /sys/block/hda/queue/scheduler
noop deadline [cfq]
# echo anticipatory > /sys/block/hda/queue/scheduler
# cat /sys/block/hda/queue/scheduler
noop [deadline] cfq

Ideally, there would be a single scheduler to satisfy all needs. It doesn't seem to exist yet. The kernel often doesn't have enough knowledge to choose the best scheduler for your workload:

  • noop is often the best choice for memory-backed block devices (e.g. ramdisks) and other non-rotational media (flash) where trying to reschedule I/O is a waste of resources
  • deadline is a lightweight scheduler which tries to put a hard limit on latency
  • cfq tries to maintain system-wide fairness of I/O bandwidth

The default was anticipatory for a long time, and it received a lot of tuning, but was removed in 2.6.33 (early 2010). cfq became the default some while ago, as its performance is reasonable and fairness is a good goal for multi-user systems (and even single-user desktops). For some scenarios -- databases are often used as examples, as they tend to already have their own peculiar scheduling and access patterns, and are often the most important service (so who cares about fairness?) -- anticipatory has a long history of being tunable for best performance on these workloads, and deadline very quickly passes all requests through to the underlying device.

How to jQuery clone() and change id?

_x000D_
_x000D_ 
$('#cloneDiv').click(function(){_x000D_
_x000D_
_x000D_
  // get the last DIV which ID starts with ^= "klon"_x000D_
  var $div = $('div[id^="klon"]:last');_x000D_
_x000D_
  // Read the Number from that DIV's ID (i.e: 3 from "klon3")_x000D_
  // And increment that number by 1_x000D_
  var num = parseInt( $div.prop("id").match(/\d+/g), 10 ) +1;_x000D_
_x000D_
  // Clone it and assign the new ID (i.e: from num 4 to ID "klon4")_x000D_
  var $klon = $div.clone().prop('id', 'klon'+num );_x000D_
_x000D_
  // Finally insert $klon wherever you want_x000D_
  $div.after( $klon.text('klon'+num) );_x000D_
_x000D_
});
_x000D_ 
<script src="https://code.jquery.com/jquery-3.1.0.js"></script>_x000D_
_x000D_
<button id="cloneDiv">CLICK TO CLONE</button> _x000D_
_x000D_
<div id="klon1">klon1</div>_x000D_
<div id="klon2">klon2</div>
_x000D_
_x000D_
_x000D_

Scrambled elements, retrieve highest ID

Say you have many elements with IDs like klon--5 but scrambled (not in order). Here we cannot go for :last or :first, therefore we need a mechanism to retrieve the highest ID:

_x000D_
_x000D_ 
const $all = $('[id^="klon--"]');_x000D_
const maxID = Math.max.apply(Math, $all.map((i, el) => +el.id.match(/\d+$/g)[0]).get());_x000D_
const nextId = maxID + 1;_x000D_
_x000D_
console.log(`New ID is: ${nextId}`);
_x000D_ 
<div id="klon--12">12</div>_x000D_
<div id="klon--34">34</div>_x000D_
<div id="klon--8">8</div>_x000D_
_x000D_
<script src="https://code.jquery.com/jquery-3.1.0.js"></script>
_x000D_
_x000D_
_x000D_

Will Google Android ever support .NET?

You're more likely to see an Android implementation of Silverlight. Microsoft rep has confirmed that it's possible, vs. the iPhone where the rep said it was problematic.

But a version of the .Net framework is possible. Just need someone to care about it that much :)

But really, moving from C# to Java isn't that big of a deal and considering the drastic differences between the two platforms (PC vs. G1) it seems unlikely that you'd be able to get by with one codebase for any app that you wanted to run on both.

How can I set the opacity or transparency of a Panel in WinForms?

Yes, opacity can only work on top-level windows. It uses a hardware feature of the video adapter, that doesn't support child windows, like Panel. The only top-level Control derived class in Winforms is Form.

Several of the 'pure' Winform controls, the ones that do their own painting instead of letting a native Windows control do the job, do however support a transparent BackColor. Panel is one of them. It uses a trick, it asks the Parent to draw itself to produce the background pixels. One side-effect of this trick is that overlapping controls doesn't work, you only see the parent pixels, not the overlapped controls.

This sample form shows it at work:

public partial class Form1 : Form {
    public Form1() {
        InitializeComponent();
        this.BackColor = Color.White;
        panel1.BackColor = Color.FromArgb(25, Color.Black);
    }
    protected override void OnPaint(PaintEventArgs e) {
        e.Graphics.DrawLine(Pens.Yellow, 0, 0, 100, 100);
    }
}

If that's not good enough then you need to consider stacking forms on top of each other. Like this.

Notable perhaps is that this restriction is lifted in Windows 8. It no longer uses the video adapter overlay feature and DWM (aka Aero) cannot be turned off anymore. Which makes opacity/transparency on child windows easy to implement. Relying on this is of course future-music for a while to come. Windows 7 will be the next XP :)

What exactly is the function of Application.CutCopyMode property in Excel

There is a good explanation at https://stackoverflow.com/a/33833319/903783

The values expected seem to be xlCopy and xlCut according to xlCutCopyMode enumeration (https://msdn.microsoft.com/en-us/VBA/Excel-VBA/articles/xlcutcopymode-enumeration-excel), but the 0 value (this is what False equals to in VBA) seems to be useful to clear Excel data put on the Clipboard.

Convert String to Type in C#

If you really want to get the type by name you may use the following:

System.AppDomain.CurrentDomain.GetAssemblies().SelectMany(x => x.GetTypes()).First(x => x.Name == "theassembly");

Note that you can improve the performance of this drastically the more information you have about the type you're trying to load.

Does JSON syntax allow duplicate keys in an object?

The short answer: Yes but is not recommended.
The long answer: It depends on what you call valid...


ECMA-404 "The JSON Data Interchange Syntax" doesn't say anything about duplicated names (keys).


However, RFC 8259 "The JavaScript Object Notation (JSON) Data Interchange Format" says:

The names within an object SHOULD be unique.

In this context SHOULD must be understood as specified in BCP 14:

SHOULD This word, or the adjective "RECOMMENDED", mean that there may exist valid reasons in particular circumstances to ignore a particular item, but the full implications must be understood and carefully weighed before choosing a different course.


RFC 8259 explains why unique names (keys) are good:

An object whose names are all unique is interoperable in the sense that all software implementations receiving that object will agree on the name-value mappings. When the names within an object are not unique, the behavior of software that receives such an object is unpredictable. Many implementations report the last name/value pair only. Other implementations report an error or fail to parse the object, and some implementations report all of the name/value pairs, including duplicates.


Also, as Serguei pointed out in the comments: ECMA-262 "ECMAScript® Language Specification", reads:

In the case where there are duplicate name Strings within an object, lexically preceding values for the same key shall be overwritten.

In other words, last-value-wins.

Trying to parse a string with duplicated names with the Java implementation by Douglas Crockford (the creator of JSON) results in an exception:

org.json.JSONException: Duplicate key "status"  at
org.json.JSONObject.putOnce(JSONObject.java:1076)

Android - running a method periodically using postDelayed() call

You should set andrid:allowRetainTaskState="true" to Launch Activity in Manifest.xml. If this Activty is not Launch Activity. you should set android:launchMode="singleTask" at this activity

How to make a GUI for bash scripts?

If you want to write a graphical UI in bash, zenity is the way to go. This is what you can do with it:

Application Options:
  --calendar                                     Display calendar dialog
  --entry                                        Display text entry dialog
  --error                                        Display error dialog
  --info                                         Display info dialog
  --file-selection                               Display file selection dialog
  --list                                         Display list dialog
  --notification                                 Display notification
  --progress                                     Display progress indication dialog
  --question                                     Display question dialog
  --warning                                      Display warning dialog
  --scale                                        Display scale dialog
  --text-info                                    Display text information dialog

Combining these widgets you can create pretty usable GUIs. Of course, it's not as flexible as a toolkit integrated into a programming language, but in some cases it's really useful.

Formatting doubles for output in C#

Another method, starting with the method:

double i = (10 * 0.69);
Console.Write(ToStringFull(i));       // Output 6.89999999999999946709294817
Console.Write(ToStringFull(-6.9)      // Output -6.90000000000000035527136788
Console.Write(ToStringFull(i - 6.9)); // Output -0.00000000000000088817841970012523233890533

A Drop-In Function...

public static string ToStringFull(double value)
{
    if (value == 0.0) return "0.0";
    if (double.IsNaN(value)) return "NaN";
    if (double.IsNegativeInfinity(value)) return "-Inf";
    if (double.IsPositiveInfinity(value)) return "+Inf";

    long bits = BitConverter.DoubleToInt64Bits(value);
    BigInteger mantissa = (bits & 0xfffffffffffffL) | 0x10000000000000L;
    int exp = (int)((bits >> 52) & 0x7ffL) - 1023;
    string sign = (value < 0) ? "-" : "";

    if (54 > exp)
    {
        double offset = (exp / 3.321928094887362358); //...or =Math.Log10(Math.Abs(value))
        BigInteger temp = mantissa * BigInteger.Pow(10, 26 - (int)offset) >> (52 - exp);
        string numberText = temp.ToString();
        int digitsNeeded = (int)((numberText[0] - '5') / 10.0 - offset);
        if (exp < 0)
            return sign + "0." + new string('0', digitsNeeded) + numberText;
        else
            return sign + numberText.Insert(1 - digitsNeeded, ".");
    }
    return sign + (mantissa >> (52 - exp)).ToString();
}

How it works

To solve this problem I used the BigInteger tools. Large values are simple as they just require left shifting the mantissa by the exponent. For small values we cannot just directly right shift as that would lose the precision bits. We must first give it some extra size by multiplying it by a 10^n and then do the right shifts. After that, we move over the decimal n places to the left. More text/code here.

Multiple FROMs - what it means

As of May 2017, multiple FROMs can be used in a single Dockerfile.
See "Builder pattern vs. Multi-stage builds in Docker" (by Alex Ellis) and PR 31257 by Tõnis Tiigi.

The general syntax involves adding FROM additional times within your Dockerfile - whichever is the last FROM statement is the final base image. To copy artifacts and outputs from intermediate images use COPY --from=<base_image_number>.

FROM golang:1.7.3 as builder
WORKDIR /go/src/github.com/alexellis/href-counter/
RUN go get -d -v golang.org/x/net/html  
COPY app.go    .
RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o app .

FROM alpine:latest  
RUN apk --no-cache add ca-certificates
WORKDIR /root/
COPY --from=builder /go/src/github.com/alexellis/href-counter/app    .
CMD ["./app"]

The result would be two images, one for building, one with just the resulting app (much, much smaller)

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE

multi               latest              bcbbf69a9b59        6 minutes ago       10.3MB  
golang              1.7.3               ef15416724f6        4 months ago        672MB

what is a base image?

A set of files, plus EXPOSE'd ports, ENTRYPOINT and CMD.
You can add files and build a new image based on that base image, with a new Dockerfile starting with a FROM directive: the image mentioned after FROM is "the base image" for your new image.

does it mean that if I declare neo4j/neo4j in a FROM directive, that when my image is run the neo database will automatically run and be available within the container on port 7474?

Only if you don't overwrite CMD and ENTRYPOINT.
But the image in itself is enough: you would use a FROM neo4j/neo4j if you had to add files related to neo4j for your particular usage of neo4j.

How to resolve ORA 00936 Missing Expression Error?

This answer is not the answer for the above mentioned question but it is related to same topic and might be useful for people searching for same error.

I faced the same error when I executed below mentioned query.

select OR.* from ORDER_REL_STAT OR

problem with above query was OR is keyword so it was expecting other values when I replaced with some other alias it worked fine.

Property 'catch' does not exist on type 'Observable<any>'

With RxJS 5.5+, the catch operator is now deprecated. You should now use the catchError operator in conjunction with pipe.

RxJS v5.5.2 is the default dependency version for Angular 5.

For each RxJS Operator you import, including catchError you should now import from 'rxjs/operators' and use the pipe operator.

Example of catching error for an Http request Observable

import { Observable } from 'rxjs';
import { catchError } from 'rxjs/operators';
...

export class ExampleClass {
  constructor(private http: HttpClient) {
    this.http.request(method, url, options).pipe(
      catchError((err: HttpErrorResponse) => {
        ...
      }
    )
  }
  ...
}

Notice here that catch is replaced with catchError and the pipe operator is used to compose the operators in similar manner to what you're used to with dot-chaining.

See the rxjs documentation on pipable (previously known as lettable) operators for more info.

The name 'ConfigurationManager' does not exist in the current context

You may also get this error if you add a reference to a different, unrelated project by mistake. Check if that applies to you.

Cassandra port usage - how are the ports used?

Ports 57311 and 57312 are randomly assigned ports used for RMI communication. These ports change each time Cassandra starts up, but need to be open in the firewall, along with 8080/7199 (depending on version), to allow for remote JMX access. Something that doesn't appear to be particularly well documented, but has tripped me up in the past.

Arrays in type script

This is a very c# type of code:

var bks: Book[] = new Book[2];

In Javascript / Typescript you don't allocate memory up front like that, and that means something completely different. This is how you would do what you want to do:

var bks: Book[] = [];
bks.push(new Book());
bks[0].Author = "vamsee";
bks[0].BookId = 1;
return bks.length;

Now to explain what new Book[2]; would mean. This would actually mean that call the new operator on the value of Book[2]. e.g.: 

Book[2] = function (){alert("hey");}
var foo = new Book[2]

and you should see hey. Try it

How prevent CPU usage 100% because of worker process in iis

If it is not necessary turn off 'Enable 32-bit Applications' from your respective application pool of your website.

This worked for me on my local machine

Force index use in Oracle

If you think the performance of the query will be better using the index, how could you force the query to use the index?

First you would of course verify that the index gave a better result for returning the complete data set, right?

The index hint is the key here, but the more up to date way of specifying it is with the column naming method rather than the index naming method. In your case you would use:

select /*+ index(table_name (column_having_index)) */ *
from   table_name
where  column_having_index="some value";

In more complex cases you might ...

select /*+ index(t (t.column_having_index)) */ *
from   my_owner.table_name t,
       ...
where  t.column_having_index="some value";

With regard to composite indexes, I'm not sure that you need to specify all columns, but it seems like a good idea. See the docs here http://docs.oracle.com/cd/E11882_01/server.112/e26088/sql_elements006.htm#autoId18 on multiple index_specs and use of index_combine for multiple indexes, and here http://docs.oracle.com/cd/E11882_01/server.112/e26088/sql_elements006.htm#BABGFHCH for the specification of multiple columns in the index_spec.

jQuery UI dialog positioning

I tried for many ways to get my dialog be centered on the page and saw that the code:

$("#dialog").dialog("option", "position", 'top')

never change the dialog position when this was created.

Instead of, I change the selector level to get the entire dialog.

$("#dialog").parent() <-- This is the parent object that the dialog() function create on the DOM, this is because the selector $("#dialog") does not apply the attributes, top, left.

To center my dialog, I use the jQuery-Client-Centering-Plugin

$("#dialog").parent().centerInClient();

Column count doesn't match value count at row 1

You can resolve the error by providing the column names you are affecting.

> INSERT INTO table_name (column1,column2,column3)
 `VALUES(50,'Jon Snow','Eye');`

please note that the semi colon should be added only after the statement providing values

How to search for rows containing a substring?

Info on MySQL's full text search. This is restricted to MyISAM tables, so may not be suitable if you wantto use a different table type.

http://dev.mysql.com/doc/refman/5.0/en/fulltext-search.html

Even if WHERE textcolumn LIKE "%SUBSTRING%" is going to be slow, I think it is probably better to let the Database handle it rather than have PHP handle it. If it is possible to restrict searches by some other criteria (date range, user, etc) then you may find the substring search is OK (ish).

If you are searching for whole words, you could pull out all the individual words into a separate table and use that to restrict the substring search. (So when searching for "my search string" you look for the the longest word "search" only do the substring search on records containing the word "search")

Specifying and saving a figure with exact size in pixels

This solution works for matplotlib versions 3.0.1, 3.0.3 and 3.2.1.

def save_inp_as_output(_img, c_name, dpi=100):
    h, w, _ = _img.shape
    fig, axes = plt.subplots(figsize=(h/dpi, w/dpi))
    fig.subplots_adjust(top=1.0, bottom=0, right=1.0, left=0, hspace=0, wspace=0) 
    axes.imshow(_img)
    axes.axis('off')
    plt.savefig(c_name, dpi=dpi, format='jpeg')

Because the subplots_adjust setting makes the axis fill the figure, you don't want to specify a bbox_inches='tight', as it actually creates whitespace padding in this case. This solution works when you have more than 1 subplot also.

Error java.lang.OutOfMemoryError: GC overhead limit exceeded

you can try to make changes on the server setting by referring to this image and increase the memory size for processing process changes highlighted in yellow

you can also make changes to java heap by opening cmd-> set _java_opts -Xmx2g
2g(2gigabytes) depending upon the complexity of your program

try to use less constant variable and temp variables

enter image description here

How to embed an autoplaying YouTube video in an iframe?

To have the accepted answer by mjhm working on Chrome 66 in May 2018, I added allow=autoplay to the iframe and enable_js=1 to the query string:

<iframe allow=autoplay width="420px" height="345px" src="http://www.youtube.com/embed/oHg5SJYRHA0?autoplay=1&enable_js=1"></iframe>

Python - PIP install trouble shooting - PermissionError: [WinError 5] Access is denied

Do not use the command prompt in the IDE. Run the command prompt from windows as an administrator. I'm sure this will solve the problem. If not, uninstall pip and reinstall the latest one directly.

Why use the params keyword?

One more important thing needs to be highlighted. It's better to use params because it is better for performance. When you call a method with params argument and passed to it nothing:

public void ExampleMethod(params string[] args)
{
// do some stuff
}

call:

ExampleMethod();

Then a new versions of the .Net Framework do this (from .Net Framework 4.6): 

ExampleMethod(Array.Empty<string>());

This Array.Empty object can be reused by framework later, so there are no needs to do redundant allocations. These allocations will occur when you call this method like this:

 ExampleMethod(new string[] {});

How to find all duplicate from a List<string>?

For what it's worth, here is my way:

List<string> list = new List<string>(new string[] { "cat", "Dog", "parrot", "dog", "parrot", "goat", "parrot", "horse", "goat" });
Dictionary<string, int> wordCount = new Dictionary<string, int>();

//count them all:
list.ForEach(word =>
{
    string key = word.ToLower();
    if (!wordCount.ContainsKey(key))
        wordCount.Add(key, 0);
    wordCount[key]++;
});

//remove words appearing only once:
wordCount.Keys.ToList().FindAll(word => wordCount[word] == 1).ForEach(key => wordCount.Remove(key));

Console.WriteLine(string.Format("Found {0} duplicates in the list:", wordCount.Count));
wordCount.Keys.ToList().ForEach(key => Console.WriteLine(string.Format("{0} appears {1} times", key, wordCount[key])));

Using variables in Nginx location rules

You can't. Nginx doesn't really support variables in config files, and its developers mock everyone who ask for this feature to be added:

"[Variables] are rather costly compared to plain static configuration. [A] macro expansion and "include" directives should be used [with] e.g. sed + make or any other common template mechanism." http://nginx.org/en/docs/faq/variables_in_config.html

You should either write or download a little tool that will allow you to generate config files from placeholder config files.

Update The code below still works, but I've wrapped it all up into a small PHP program/library called Configurator also on Packagist, which allows easy generation of nginx/php-fpm etc config files, from templates and various forms of config data.

e.g. my nginx source config file looks like this:

location  / {
    try_files $uri /routing.php?$args;
    fastcgi_pass   unix:%phpfpm.socket%/php-fpm-www.sock;
    include       %mysite.root.directory%/conf/fastcgi.conf;
}

And then I have a config file with the variables defined:

phpfpm.socket=/var/run/php-fpm.socket
mysite.root.directory=/home/mysite

And then I generate the actual config file using that. It looks like you're a Python guy, so a PHP based example may not help you, but for anyone else who does use PHP:

<?php

require_once('path.php');

$filesToGenerate = array(
    'conf/nginx.conf' => 'autogen/nginx.conf',
    'conf/mysite.nginx.conf' => 'autogen/mysite.nginx.conf',
    'conf/mysite.php-fpm.conf' => 'autogen/mysite.php-fpm.conf',
    'conf/my.cnf' => 'autogen/my.cnf',
);

$environment = 'amazonec2';

if ($argc >= 2){
    $environmentRequired = $argv[1];

    $allowedVars = array(
        'amazonec2',
        'macports',
    );

    if (in_array($environmentRequired, $allowedVars) == true){
        $environment = $environmentRequired;
    }
}
else{
    echo "Defaulting to [".$environment."] environment";
}

$config = getConfigForEnvironment($environment);

foreach($filesToGenerate as $inputFilename => $outputFilename){
    generateConfigFile(PATH_TO_ROOT.$inputFilename, PATH_TO_ROOT.$outputFilename, $config);
}


function    getConfigForEnvironment($environment){
    $config = parse_ini_file(PATH_TO_ROOT."conf/deployConfig.ini", TRUE);
    $configWithMarkers = array();
    foreach($config[$environment] as $key => $value){
        $configWithMarkers['%'.$key.'%'] = $value;
    }

    return  $configWithMarkers;
}


function    generateConfigFile($inputFilename, $outputFilename, $config){

    $lines = file($inputFilename);

    if($lines === FALSE){
        echo "Failed to read [".$inputFilename."] for reading.";
        exit(-1);
    }

    $fileHandle = fopen($outputFilename, "w");

    if($fileHandle === FALSE){
        echo "Failed to read [".$outputFilename."] for writing.";
        exit(-1);
    }

    $search = array_keys($config);
    $replace = array_values($config);

    foreach($lines as $line){
        $line = str_replace($search, $replace, $line);
        fwrite($fileHandle, $line);
    }

    fclose($fileHandle);
}

?>

And then deployConfig.ini looks something like:

[global]

;global variables go here.

[amazonec2]
nginx.log.directory = /var/log/nginx
nginx.root.directory = /usr/share/nginx
nginx.conf.directory = /etc/nginx
nginx.run.directory  = /var/run
nginx.user           = nginx

[macports]
nginx.log.directory = /opt/local/var/log/nginx
nginx.root.directory = /opt/local/share/nginx
nginx.conf.directory = /opt/local/etc/nginx
nginx.run.directory  = /opt/local/var/run
nginx.user           = _www

Regex doesn't work in String.matches()

Your regular expression [a-z] doesn't match dkoe since it only matches Strings of lenght 1. Use something like [a-z]+.

Getting a count of rows in a datatable that meet certain criteria

One easy way to accomplish this is combining what was posted in the original post into a single statement:

int numberOfRecords = dtFoo.Select("IsActive = 'Y'").Length;

Another way to accomplish this is using Linq methods:

int numberOfRecords = dtFoo.AsEnumerable().Where(x => x["IsActive"].ToString() == "Y").ToList().Count;

Note this requires including System.Linq.

Spring .properties file: get element as an Array

Here is an example of how you can do it in Spring 4.0+

application.properties content:

some.key=yes,no,cancel

Java Code:

@Autowire
private Environment env;

...

String[] springRocks = env.getProperty("some.key", String[].class);

Check div is hidden using jquery

Try checking for the :visible property instead.

if($('#car2').not(':visible'))
{
    alert('car 2 is hidden');       
}

Disable building workspace process in Eclipse

For anyone running into a problem where build automatically is unchecked but the project is still building. Make sure your project isn't deployed to the server in the server tab and told to stay synchronous.

Hide horizontal scrollbar on an iframe?

I'd suggest doing this with a combination of

  1. CSS overflow-y: hidden;
  2. scrolling="no" (for HTML4)
  3. and seamless="seamless" (for HTML5)*

* The seamless attribute has been removed from the standard, and no browsers support it.

_x000D_
_x000D_ 
.foo {_x000D_
  width: 200px;_x000D_
  height: 200px;_x000D_
  overflow-y: hidden;_x000D_
}
_x000D_ 
<iframe src="https://bing.com" _x000D_
        class="foo" _x000D_
        scrolling="no" >_x000D_
</iframe>
_x000D_
_x000D_
_x000D_

How to force Chrome browser to reload .css file while debugging in Visual Studio?

You are dealing with the problem of browser cache.

Disable the cache in the page itself. That will not save supporting file of page in browser/cache.

<meta http-equiv="cache-control" content="max-age=0" />
<meta http-equiv="cache-control" content="no-cache" />
<meta http-equiv="expires" content="0" />
<meta http-equiv="expires" content="Tue, 01 Jan 1990 12:00:00 GMT" />

This code you require/need to insert in head tag of the page you are debugging, or in head tag of master page of your site

This will not allow browser to cache file, eventually files will not be stored in browser temporary files, so no cache, so no reloading will be required :)

I am sure this will do :)

pip broke. how to fix DistributionNotFound error?

I find this problem in my MacBook, the reason is because as @Stephan said, I use easy_install to install pip, and the mixture of both py package manage tools led to the pkg_resources.DistributionNotFound problem. The resolve is:

easy_install --upgrade pip

Remember: just use one of the above tools to manage your Py packages.

Ripple effect on Android Lollipop CardView

For those searching for a solution to the issue of the ripple effect not working on a programmatically created CardView (or in my case custom view which extends CardView) being shown in a RecyclerView, the following worked for me. Basically declaring the XML attributes mentioned in the other answers declaratively in the XML layout file doesn't seem to work for a programmatically created CardView, or one created from a custom layout (even if root view is CardView or merge element is used), so they have to be set programmatically like so:

private class MadeUpCardViewHolder extends RecyclerView.ViewHolder {
    private MadeUpCardView cardView;

    public MadeUpCardViewHolder(View v){
        super(v);

        this.cardView = (MadeUpCardView)v;

        // Declaring in XML Layout doesn't seem to work in RecyclerViews
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            int[] attrs = new int[]{R.attr.selectableItemBackground};
            TypedArray typedArray = context.obtainStyledAttributes(attrs);
            int selectableItemBackground = typedArray.getResourceId(0, 0);
            typedArray.recycle();

            this.cardView.setForeground(context.getDrawable(selectableItemBackground));
            this.cardView.setClickable(true);
        }
    }
}

Where MadeupCardView extends CardView Kudos to this answer for the TypedArray part.

How can I debug a HTTP POST in Chrome?

It has a tricky situation: If you submit a post form, then Chrome will open a new tab to send the request. It's right until now, but if it triggers an event to download file(s), this tab will close immediately so that you cannot capture this request in the Dev Tool.

Solution: Before submitting the post form, you need to cut off your network, which makes the request cannot send successfully so that the tab will not be closed. And then you can capture the request message in the Chrome Devtool(Refreshing the new tab if necessary)

How to get the excel file name / path in VBA

this is a simple alternative that gives all responses, Fullname, Path, filename.

Dim FilePath, FileOnly, PathOnly As String

FilePath = ThisWorkbook.FullName
FileOnly = ThisWorkbook.Name
PathOnly = Left(FilePath, Len(FilePath) - Len(FileOnly))

Get all Attributes from a HTML element with Javascript/jQuery

Setter and Getter!

(function($) {
    // Attrs
    $.fn.attrs = function(attrs) {
        var t = $(this);
        if (attrs) {
            // Set attributes
            t.each(function(i, e) {
                var j = $(e);
                for (var attr in attrs) {
                    j.attr(attr, attrs[attr]);
                }
            });
            return t;
        } else {
            // Get attributes
            var a = {},
                r = t.get(0);
            if (r) {
                r = r.attributes;
                for (var i in r) {
                    var p = r[i];
                    if (typeof p.nodeValue !== 'undefined') a[p.nodeName] = p.nodeValue;
                }
            }
            return a;
        }
    };
})(jQuery);

Use:

// Setter
$('#element').attrs({
    'name' : 'newName',
    'id' : 'newId',
    'readonly': true
});

// Getter
var attrs = $('#element').attrs();

Replace non-numeric with empty string

Using the Regex methods in .NET you should be able to match any non-numeric digit using \D, like so:

phoneNumber  = Regex.Replace(phoneNumber, "\\D", String.Empty);

Check existence of directory and create if doesn't exist

One-liner:

if (!dir.exists(output_dir)) {dir.create(output_dir)}

Example:

dateDIR <- as.character(Sys.Date())
outputDIR <- file.path(outD, dateDIR)
if (!dir.exists(outputDIR)) {dir.create(outputDIR)}

How to execute an Oracle stored procedure via a database link

The syntax is

EXEC mySchema.myPackage.myProcedure@myRemoteDB( 'someParameter' );

Toad for Oracle..How to execute multiple statements?

Highlight everything you want to run and run as a script. You can do that by clicking the icon on the menu bar that looks like a text file with a lightning bolt on it. That is the same as hitting F5. So if F5 doesn't work you probably have an error in your script.

Do you have semicolons after each statement?

Create XML file using java

You can use a DOM XML parser to create an XML file using Java. A good example can be found on this site:

try {
    DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
    DocumentBuilder docBuilder = docFactory.newDocumentBuilder();

    //root elements
    Document doc = docBuilder.newDocument();

    Element rootElement = doc.createElement("company");
    doc.appendChild(rootElement);

    //staff elements
    Element staff = doc.createElement("Staff");
    rootElement.appendChild(staff);

    //set attribute to staff element
    Attr attr = doc.createAttribute("id");
    attr.setValue("1");
    staff.setAttributeNode(attr);

    //shorten way
    //staff.setAttribute("id", "1");

    //firstname elements
    Element firstname = doc.createElement("firstname");
    firstname.appendChild(doc.createTextNode("yong"));
    staff.appendChild(firstname);

    //lastname elements
    Element lastname = doc.createElement("lastname");
    lastname.appendChild(doc.createTextNode("mook kim"));
    staff.appendChild(lastname);

    //nickname elements
    Element nickname = doc.createElement("nickname");
    nickname.appendChild(doc.createTextNode("mkyong"));
    staff.appendChild(nickname);

    //salary elements
    Element salary = doc.createElement("salary");
    salary.appendChild(doc.createTextNode("100000"));
    staff.appendChild(salary);

    //write the content into xml file
    TransformerFactory transformerFactory =  TransformerFactory.newInstance();
    Transformer transformer = transformerFactory.newTransformer();
    DOMSource source = new DOMSource(doc);

    StreamResult result =  new StreamResult(new File("C:\\testing.xml"));
    transformer.transform(source, result);

    System.out.println("Done");

}catch(ParserConfigurationException pce){
    pce.printStackTrace();
}catch(TransformerException tfe){
    tfe.printStackTrace();
}

Eclipse: Set maximum line length for auto formatting?

In preferences Java -> Code Style -> Formatter, edit the profile. Under the Line Wrapping tab is the primary option for line width (Maximum line width:). In the Comments tab you have a separate option Maximum line width for comments:, which will also need to be changed to affect comment wrapping.

You will need to make your own profile to make these changes in if you using one of the [Built-in] ones. Just click "New..." on the formatter preferences page.

The import com.google.android.gms cannot be resolved

Above solutions should solve your problem. If these do not, make sure you update your Android sdk using SDK manager and install the latest lib project and then repeat the above steps again.

How to DROP multiple columns with a single ALTER TABLE statement in SQL Server?

For SQL Server:

ALTER TABLE TableName
    DROP COLUMN Column1, Column2;

The syntax is

DROP { [ CONSTRAINT ] constraint_name | COLUMN column } [ ,...n ]

For MySQL:

ALTER TABLE TableName
    DROP COLUMN Column1,
    DROP COLUMN Column2;

or like this1:

ALTER TABLE TableName
    DROP Column1,
    DROP Column2;

1 The word COLUMN is optional and can be omitted, except for RENAME COLUMN (to distinguish a column-renaming operation from the RENAME table-renaming operation). More info here.

Could not find module FindOpenCV.cmake ( Error in configuration process)

On my Fedora machine, when I typed "make" I got an error saying it could not find "cv.h". I fixed this by modifying my "OpenCVConfig.cmake" file.

Before:

SET(OpenCV_INCLUDE_DIRS "${OpenCV_INSTALL_PATH}/include/opencv;${OpenCV_INSTALL_PATH}/include")

SET(OpenCV_LIB_DIR "${OpenCV_INSTALL_PATH}/lib64")

After:

SET(OpenCV_INCLUDE_DIRS "/usr/include/opencv;/usr/include/opencv2")

SET(OpenCV_LIB_DIR "/usr/lib64")

Why is SQL Server 2008 Management Studio Intellisense not working?

No need to reinstall.

Click on the setup file. Then go to maintenance and click on Repair. This should correct the intellisense problem.

Instantiating a generic class in Java

I really need to instantiate a T in Foo using a parameter-less constructor

Simple answer is "you cant do that" java uses type erasure to implment generics which would prevent you from doing this.

How can one work around Java's limitation?

One way (there could be others) is to pass the object that you would pass the instance of T to the constructor of Foo<T>. Or you could have a method setBar(T theInstanceofT); to get your T instead of instantiating in the class it self.

In reactJS, how to copy text to clipboard?

For those people who are trying to select from the DIV instead of the text field, here is the code. The code is self-explanatory but comment here if you want more information: 

     import React from 'react';
     ....

    //set ref to your div
          setRef = (ref) => {
            // debugger; //eslint-disable-line
            this.dialogRef = ref;
          };

          createMarkeup = content => ({
            __html: content,
          });

    //following function select and copy data to the clipboard from the selected Div. 
   //Please note that it is only tested in chrome but compatibility for other browsers can be easily done

          copyDataToClipboard = () => {
            try {
              const range = document.createRange();
              const selection = window.getSelection();
              range.selectNodeContents(this.dialogRef);
              selection.removeAllRanges();
              selection.addRange(range);
              document.execCommand('copy');
              this.showNotification('Macro copied successfully.', 'info');
              this.props.closeMacroWindow();
            } catch (err) {
              // console.log(err); //eslint-disable-line
              //alert('Macro copy failed.');
            }
          };

              render() {
                    return (
                        <div
                          id="macroDiv"
                          ref={(el) => {
                            this.dialogRef = el;
                          }}
                          // className={classes.paper}
                          dangerouslySetInnerHTML={this.createMarkeup(this.props.content)}
                        />
                    );
            }

Smooth GPS data

You can also use a spline. Feed in the values you have and interpolate points between your known points. Linking this with a least-squares fit, moving average or kalman filter (as mentioned in other answers) gives you the ability to calculate the points inbetween your "known" points.

Being able to interpolate the values between your knowns gives you a nice smooth transition and a /reasonable/ approximation of what data would be present if you had a higher-fidelity. http://en.wikipedia.org/wiki/Spline_interpolation

Different splines have different characteristics. The one's I've seen most commonly used are Akima and Cubic splines.

Another algorithm to consider is the Ramer-Douglas-Peucker line simplification algorithm, it is quite commonly used in the simplification of GPS data. (http://en.wikipedia.org/wiki/Ramer-Douglas-Peucker_algorithm)

MySQL stored procedure vs function, which would I use when?

Stored procedure can be called recursively but stored function can not

How to get local server host and port in Spring Boot?

I used to declare the configuration in application.properties like this (you can use you own property file)

server.host = localhost
server.port = 8081

and in application you can get it easily by @Value("${server.host}") and @Value("${server.port}") as field level annotation.

or if in your case it is dynamic than you can get from system properties

Here is the example

@Value("#{systemproperties['server.host']}")
@Value("#{systemproperties['server.port']}")

For a better understanding of this annotation , see this example Multiple uses of @Value annotation

How to save a spark DataFrame as csv on disk?

I had similar issue where i had to save the contents of the dataframe to a csv file of name which i defined. df.write("csv").save("<my-path>") was creating directory than file. So have to come up with the following solutions. Most of the code is taken from the following dataframe-to-csv with little modifications to the logic. 

def saveDfToCsv(df: DataFrame, tsvOutput: String, sep: String = ",", header: Boolean = false): Unit = {
    val tmpParquetDir = "Posts.tmp.parquet"

    df.repartition(1).write.
        format("com.databricks.spark.csv").
        option("header", header.toString).
        option("delimiter", sep).
        save(tmpParquetDir)

    val dir = new File(tmpParquetDir)
    val newFileRgex = tmpParquetDir + File.separatorChar + ".part-00000.*.csv"
    val tmpTsfFile = dir.listFiles.filter(_.toPath.toString.matches(newFileRgex))(0).toString
    (new File(tmpTsvFile)).renameTo(new File(tsvOutput))

    dir.listFiles.foreach( f => f.delete )
    dir.delete
    }

Joda DateTime to Timestamp conversion

Actually this is not a duplicate question. And this how i solve my problem after several times :

   int offset = DateTimeZone.forID("anytimezone").getOffset(new DateTime());

This is the way to get offset from desired timezone.

Let's return to our code, we were getting timestamp from a result set of query, and using it with timezone to create our datetime. 

   DateTime dt = new DateTime(rs.getTimestamp("anytimestampcolumn"),
                         DateTimeZone.forID("anytimezone"));

Now we will add our offset to the datetime, and get the timestamp from it.

    dt = dt.plusMillis(offset);
    Timestamp ts = new Timestamp(dt.getMillis());

May be this is not the actual way to get it, but it solves my case. I hope it helps anyone who is stuck here.

Python loop for inside lambda

If you are like me just want to print a sequence within a lambda, without get the return value (list of None).

x = range(3)
from __future__ import print_function           # if not python 3
pra = lambda seq=x: map(print,seq) and None     # pra for 'print all'
pra()
pra('abc')

What is a faster alternative to Python's http.server (or SimpleHTTPServer)?

I recommend: Twisted (http://twistedmatrix.com)

an event-driven networking engine written in Python and licensed under the open source MIT license.

It's cross-platform and was preinstalled on OS X 10.5 to 10.12. Amongst other things you can start up a simple web server in the current directory with:

twistd -no web --path=.

Details

Explanation of Options (see twistd --help for more):

-n, --nodaemon       don't daemonize, don't use default umask of 0077
-o, --no_save        do not save state on shutdown

"web" is a Command that runs a simple web server on top of the Twisted async engine. It also accepts command line options (after the "web" command - see twistd web --help for more):

  --path=             <path> is either a specific file or a directory to be
                      set as the root of the web server. Use this if you
                      have a directory full of HTML, cgi, php3, epy, or rpy
                      files or any other files that you want to be served up
                      raw.

There are also a bunch of other commands such as:

conch            A Conch SSH service.
dns              A domain name server.
ftp              An FTP server.
inetd            An inetd(8) replacement.
mail             An email service
... etc

Installation

Ubuntu

sudo apt-get install python-twisted-web (or python-twisted for the full engine)

Mac OS-X (comes preinstalled on 10.5 - 10.12, or is available in MacPorts and through Pip)

sudo port install py-twisted

Windows

installer available for download at http://twistedmatrix.com/

HTTPS

Twisted can also utilise security certificates to encrypt the connection. Use this with your existing --path and --port (for plain HTTP) options.

twistd -no web -c cert.pem -k privkey.pem --https=4433

Inserting a value into all possible locations in a list

If you want to insert a list into a list, you can do this:

>>> a = [1,2,3,4,5]
>>> for x in reversed(['a','b','c']): a.insert(2,x)
>>> a
[1, 2, 'a', 'b', 'c', 3, 4, 5]

Difference between using "chmod a+x" and "chmod 755"

chmod a+x modifies the argument's mode while chmod 755 sets it. Try both variants on something that has full or no permissions and you will notice the difference.

Is it possible to get only the first character of a String?

Java strings are simply an array of char. So, char c = s[0] where s is string.

How can I make PHP display the error instead of giving me 500 Internal Server Error

Enabling error displaying from PHP code doesn't work out for me. In my case, using NGINX and PHP-FMP, I track the log file using grep. For instance, I know the file name mycode.php causes the error 500, but don't know which line. From the console, I use this:

/var/log/php-fpm# cat www-error.log | grep mycode.php

And I have the output:

[04-Apr-2016 06:58:27] PHP Parse error:  syntax error, unexpected ';' in /var/www/html/system/mycode.php on line 1458

This helps me find the line where I have the typo.

Pandas: create two new columns in a dataframe with values calculated from a pre-existing column

I'd just use zip:

In [1]: from pandas import *

In [2]: def calculate(x):
   ...:     return x*2, x*3
   ...: 

In [3]: df = DataFrame({'a': [1,2,3], 'b': [2,3,4]})

In [4]: df
Out[4]: 
   a  b
0  1  2
1  2  3
2  3  4

In [5]: df["A1"], df["A2"] = zip(*df["a"].map(calculate))

In [6]: df
Out[6]: 
   a  b  A1  A2
0  1  2   2   3
1  2  3   4   6
2  3  4   6   9

Firebase cloud messaging notification not received by device

I had the same problem and it is solved by defining enabled, exported to true in my service

  <service
            android:name=".MyFirebaseMessagingService"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="com.google.firebase.MESSAGING_EVENT"/>
            </intent-filter>
        </service>

The request was rejected because no multipart boundary was found in springboot

I met this problem because I use request.js which writen base on axios
And I already set a defaults.headers in request.js

import axios from 'axios'
const request = axios.create({
  baseURL: '', 
  timeout: 15000 
})
service.defaults.headers.post['Content-Type'] = 'application/x-www-form-urlencoded'

here is how I solve this
instead of 

request.post('/manage/product/upload.do',
      param,config
    )

I use axios directly send request,and didn't add config

axios.post('/manage/product/upload.do',
      param
    )

hope this can solve your problem

What is the difference between parseInt() and Number()?

If you are looking for performance then probably best results you'll get with bitwise right shift "10">>0. Also multiply ("10" * 1) or not not (~~"10"). All of them are much faster of Number and parseInt. They even have "feature" returning 0 for not number argument. Here are Performance tests.

What does "where T : class, new()" mean?

Those are generic type constraints. In your case there are two of them:

where T : class

Means that the type T must be a reference type (not a value type).

where T : new()

Means that the type T must have a parameter-less constructor. Having this constraint will allow you to do something like T field = new T(); in your code which you wouldn't be able to do otherwise.

You then combine the two using a comma to get:

where T : class, new()

Visual Studio 2013 License Product Key

I solved this, without having to completely reinstall Visual Studio 2013.

For those who may come across this in the future, the following steps worked for me:

  1. Run the ISO (or vs_professional.exe).

  2. If you get the error below, you need to update the Windows Registry to trick the installer into thinking you still have the base version. If you don't get this error, skip to step 3 "The product version that you are trying to set up is earlier than the version already installed on this computer."

    • Click the link for 'examine the log file' and look near the bottom of the log, for this line: Detected related bundle ... operation: Downgrade

    • open regedit.exe and do an Edit > Find... for that GUID. In my case it was {6dff50d0-3bc3-4a92-b724-bf6d6a99de4f}. This was found in:

      HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall{6dff50d0-3bc3-4a92-b724-bf6d6a99de4f}

    • Edit the BundleVersion value and change it to a lower version. I changed mine from 12.0.21005.13 to 12.0.21000.13: BundleVersion for Visual Studio lower the version for BundleVersion

    • Exit the registry

  3. Run the ISO (or vs_professional.exe) again. If it has a repair button like the image below, you can skip to step 4.

    Visual Studio Repair button

    • Otherwise you have to let the installer fix the registry. I did this by "installing" at least one feature, even though I think I already had all features (they were not detected). This took about 20 minutes.

  4. Run the ISO (or vs_professional.exe) again. This time repair should be visible.

  5. Click Repair and let it update your installation and apply its embedded license key. This took about 20 minutes.

Now when you run Visual Studio 2013, it should indicate that a license key was applied, under Help > Register Product:

License: Product key applied

Hope this helps somebody in the future!

Reference blog 'story'

Links in <select> dropdown options

You can use the onChange property. Something like:

<select onChange="window.location.href=this.value">
    <option value="www.google.com">A</option>
    <option value="www.aol.com">B</option>
</select>

How to give a pattern for new line in grep?

You can use this way...

grep -P '^\s$' file
  • -P is used for Perl regular expressions (an extension to POSIX grep).
  • \s match the white space characters; if followed by *, it matches an empty line also.
  • ^ matches the beginning of the line. $ matches the end of the line.

Git: force user and password prompt

Add a -v flag with your git command . e.g. git pull -v

v stands for verify .

Writing to a new file if it doesn't exist, and appending to a file if it does

It's not clear to me exactly where the high-score that you're interested in is stored, but the code below should be what you need to check if the file exists and append to it if desired. I prefer this method to the "try/except".

import os
player = 'bob'

filename = player+'.txt'

if os.path.exists(filename):
    append_write = 'a' # append if already exists
else:
    append_write = 'w' # make a new file if not

highscore = open(filename,append_write)
highscore.write("Username: " + player + '\n')
highscore.close()

Python TypeError: cannot convert the series to <class 'int'> when trying to do math on dataframe

Seems your initial data contains strings and not numbers. It would probably be best to ensure that the data is already of the required type up front.

However, you can convert strings to numbers like this:

pd.Series(['123', '42']).astype(float)

instead of float(series)

Role/Purpose of ContextLoaderListener in Spring?

Basically you can isolate your root application context and web application context using ContextLoaderListner.

The config file mapped with context param will behave as root application context configuration. And config file mapped with dispatcher servlet will behave like web application context.

In any web application we may have multiple dispatcher servlets, so multiple web application contexts.

But in any web application we may have only one root application context that is shared with all web application contexts.

We should define our common services, entities, aspects etc in root application context. And controllers, interceptors etc are in relevant web application context.

A sample web.xml is

<!-- language: xml -->
<web-app>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <context-param>
        <param-name>contextClass</param-name>
        <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>
    </context-param>
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>example.config.AppConfig</param-value>
    </context-param>
    <servlet>
        <servlet-name>restEntryPoint</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextClass</param-name>
            <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>
        </init-param>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>example.config.RestConfig</param-value>
        </init-param>       
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>restEntryPoint</servlet-name>
        <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>
    <servlet>
        <servlet-name>webEntryPoint</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextClass</param-name>
            <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>
        </init-param>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>example.config.WebConfig</param-value>
        </init-param>       
        <load-on-startup>1</load-on-startup>
    </servlet>  
    <servlet-mapping>
        <servlet-name>webEntryPoint</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

Here config class example.config.AppConfig can be used to configure services, entities, aspects etc in root application context that will be shared with all other web application contexts (for example here we have two web application context config classes RestConfig and WebConfig)

PS: Here ContextLoaderListener is completely optional. If we will not mention ContextLoaderListener in web.xml here, AppConfig will not work. In that case we need to configure all our services and entities in WebConfig and Rest Config.

Converting integer to digit list

If you have a string like this: '123456' and you want a list of integers like this: [1,2,3,4,5,6], use this:

>>>s = '123456'    
>>>list1 = [int(i) for i in list(s)]
>>>print(list1)

[1,2,3,4,5,6]

or if you want a list of strings like this: ['1','2','3','4','5','6'], use this:

>>>s = '123456'    
>>>list1 = list(s)
>>>print(list1)

['1','2','3','4','5','6']

How to get data out of a Node.js http get request

from learnyounode:

var http = require('http')
var bl = require('bl')

http.get(process.argv[2], function (response) {
    response.pipe(bl(function (err, data) {
        if (err)
            return console.error(err)
        data = data.toString()
        console.log(data)
    }))
})

Flexbox Not Centering Vertically in IE

The original answer from https://github.com/philipwalton/flexbugs/issues/231#issuecomment-362790042

.flex-container{
min-height:100px;
display:flex;
align-items:center;
}

.flex-container:after{
content:'';
min-height:inherit;
font-size:0;
}

SUM of grouped COUNT in SQL Query

I required having count(*) > 1 also. So, I wrote my own query after referring some the above queries

SYNTAX:

select sum(count) from (select count(`table_name`.`id`) as `count` from `table_name` where {some condition} group by {some_column} having count(`table_name`.`id`) > 1) as `tmp`;

Example:

select sum(count) from (select count(`table_name`.`id`) as `count` from `table_name` where `table_name`.`name` IS NOT NULL and `table_name`.`name` != '' group by `table_name`.`name` having count(`table_name`.`id`) > 1) as `tmp`;

Having the output of a console application in Visual Studio instead of the console

In the Visual Studio Options Dialog -> Debugging -> Check the "Redirect All Output Window Text to the Immediate Window". Then go to your project settings and change the type from "Console Application" to "Windows Application". At that point Visual Studio does not open up a console window anymore, and the output is redirected to the Output window in Visual Studio. However, you cannot do anything "creative", like requesting key or text input, or clearing the console - you'll get runtime exceptions.

need to test if sql query was successful

 
if ($DB->query(...)) { success }
else { failure }

query should return false on failure (if you're using mysql_query or $mysqli->query). If you want to test if the UPDATE query actually did anything (which is a totally different thing than "successful") then use mysql_affected_rows or $mysqli->affected_rows

Insert all data of a datagridview to database at once

If you move your for loop, you won't have to make multiple connections. Just a quick edit to your code block (by no means completely correct):

string StrQuery;
try
{
    using (SqlConnection conn = new SqlConnection(ConnString))
    {
        using (SqlCommand comm = new SqlCommand())
        {
            comm.Connection = conn;
            conn.Open();
            for(int i=0; i< dataGridView1.Rows.Count;i++)
            {
                StrQuery= @"INSERT INTO tableName VALUES (" 
                    + dataGridView1.Rows[i].Cells["ColumnName"].Text+", " 
                    + dataGridView1.Rows[i].Cells["ColumnName"].Text+");";
                comm.CommandText = StrQuery;
                comm.ExecuteNonQuery();
            }
        }
    }
}

As to executing multiple SQL commands at once, please look at this link: Multiple statements in single SqlCommand

Pass in an enum as a method parameter

First change the method parameter Enum supportedPermissions to SupportedPermissions supportedPermissions.

Then create your file like this

file = new File
{  
    Name = name,
    Id = id,
    Description = description,
    SupportedPermissions = supportedPermissions
};

And the call to your method should be

CreateFile(id, name, description, SupportedPermissions.basic);

How do you create a static class in C++?

As it has been noted here, a better way of achieving this in C++ might be using namespaces. But since no one has mentioned the final keyword here, I'm posting what a direct equivalent of static class from C# would look like in C++11 or later:

class BitParser final
{
public:
  BitParser() = delete;

  static bool GetBitAt(int buffer, int pos);
};

bool BitParser::GetBitAt(int buffer, int pos)
{
  // your code
}

SQL Query for Student mark functionality

 
 select max(m.mark)  as maxMarkObtained,su.Subname from Student s 
  inner join Marks m on s.Stid=m.Stid inner join [Subject] su on
  su.Subid=m.Subid group by su.Subname

I have execute it , this should work.

How to create named and latest tag in Docker?

You can have multiple tags when building the image:

$ docker build -t whenry/fedora-jboss:latest -t whenry/fedora-jboss:v2.1 .

Reference: https://docs.docker.com/engine/reference/commandline/build/#tag-image-t

Origin null is not allowed by Access-Control-Allow-Origin

I would like to humbly add that according to this SO source: https://stackoverflow.com/a/14671362/1743693, this kind of trouble is now partially solved simply by using the following jQuery instruction:

<script> 
    $.support.cors = true;
</script>

I tried it on IE10.0.9200, and it worked immediately (using jquery-1.9.0.js).

On chrome 28.0.1500.95 - this instruction doesn't work (this happens all over as david complains in the comments at the link above)

Running chrome with --allow-file-access-from-files did not work for me (as Maistora's claims above)

wordpress contactform7 textarea cols and rows change in smaller screens

Code will be As below.

[textarea id:message 0x0 class:custom-class "Insert text here"]<!-- No Rows No columns -->

[textarea id:message x2 class:custom-class "Insert text here"]<!-- Only Rows -->

[textarea id:message 12x class:custom-class "Insert text here"]<!-- Only Columns -->

[textarea id:message 10x2 class:custom-class "Insert text here"]<!-- Both Rows and Columns -->

For Details: https://contactform7.com/text-fields/

Sqlite or MySql? How to decide?

The sqlite team published an article explaining when to use sqlite that is great read. Basically, you want to avoid using sqlite when you have a lot of write concurrency or need to scale to terabytes of data. In many other cases, sqlite is a surprisingly good alternative to a "traditional" database such as MySQL.

Adding a Scrollable JTextArea (Java)

It doesn't work because you didn't attach the ScrollPane to the JFrame.

Also, you don't need 2 JScrollPanes:

JFrame frame = new JFrame ("Test");
JTextArea textArea = new JTextArea ("Test");

JScrollPane scroll = new JScrollPane (textArea, 
   JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);

frame.add(scroll);
frame.setVisible (true);

ERROR Error: No value accessor for form control with unspecified name attribute on switch

I had the same problem and the issue was that my child component had an @input named formControl.

So I just needed to change from:

<my-component [formControl]="formControl"><my-component/>

to:

<my-component [control]="control"><my-component/>

ts:

@Input()
control:FormControl;

Python FileNotFound

try block should be around open. Not around prompt.

while True:
    prompt = input("\n Hello to Sudoku valitator,"
    "\n \n Please type in the path to your file and press 'Enter': ")
    try:
        sudoku = open(prompt, 'r').readlines()
    except FileNotFoundError:
        print("Wrong file or file path")
    else:
        break

If list index exists, do X

If you want to iterate the inserted actors data:

for i in range(n):
    if len(nams[i]) > 3:
        do_something
    if len(nams[i]) > 4:
        do_something_else

Splitting applicationContext to multiple files

There are two types of contexts we are dealing with:

1: root context (parent context. Typically include all jdbc(ORM, Hibernate) initialisation and other spring security related configuration)

2: individual servlet context (child context.Typically Dispatcher Servlet Context and initialise all beans related to spring-mvc (controllers , URL Mapping etc)).

Here is an example of web.xml which includes multiple application context file

_x000D_
_x000D_ 
<?xml version="1.0" encoding="UTF-8"?>_x000D_
<web-app xmlns="http://java.sun.com/xml/ns/javaee"_x000D_
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"_x000D_
        xsi:schemaLocation="http://java.sun.com/xml/ns/javaee_x000D_
                            http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">_x000D_
_x000D_
    <display-name>Spring Web Application example</display-name>_x000D_
_x000D_
    <!-- Configurations for the root application context (parent context) -->_x000D_
    <listener>_x000D_
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>_x000D_
    </listener>_x000D_
    <context-param>_x000D_
        <param-name>contextConfigLocation</param-name>_x000D_
        <param-value>_x000D_
            /WEB-INF/spring/jdbc/spring-jdbc.xml <!-- JDBC related context -->_x000D_
            /WEB-INF/spring/security/spring-security-context.xml <!-- Spring Security related context -->_x000D_
        </param-value>_x000D_
    </context-param>_x000D_
_x000D_
    <!-- Configurations for the DispatcherServlet application context (child context) -->_x000D_
    <servlet>_x000D_
        <servlet-name>spring-mvc</servlet-name>_x000D_
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>_x000D_
        <init-param>_x000D_
            <param-name>contextConfigLocation</param-name>_x000D_
            <param-value>_x000D_
                /WEB-INF/spring/mvc/spring-mvc-servlet.xml_x000D_
            </param-value>_x000D_
        </init-param>_x000D_
    </servlet>_x000D_
    <servlet-mapping>_x000D_
        <servlet-name>spring-mvc</servlet-name>_x000D_
        <url-pattern>/admin/*</url-pattern>_x000D_
    </servlet-mapping>_x000D_
_x000D_
</web-app>
_x000D_
_x000D_
_x000D_

Check whether there is an Internet connection available on Flutter app

I having some problem with the accepted answer, but it seems it solve answer for others. I would like a solution that can get a response from the url it uses, so I thought http would be great for that functionality, and for that I found this answer really helpful. How do I check Internet Connectivity using HTTP requests(Flutter/Dart)?

How to close a web page on a button click, a hyperlink or a link button click?

To close a windows form (System.Windows.Forms.Form) when one of its button is clicked: in Visual Studio, open the form in the designer, right click on the button and open its property page, then select the field DialogResult an set it to OK or the appropriate value.

I need to convert an int variable to double

You have to cast one (or both) of the arguments to the division operator to double:

double firstSolution = (b1 * a22 - b2 * a12) / (double)(a11 * a22 - a12 * a21);

Since you are performing the same calculation twice I'd recommend refactoring your code:

double determinant = a11 * a22 - a12 * a21;
double firstSolution = (b1 * a22 - b2 * a12) / determinant;
double secondSolution = (b2 * a11 - b1 * a21) / determinant;

This works in the same way, but now there is an implicit cast to double. This conversion from int to double is an example of a widening primitive conversion.

Python: Convert timedelta to int in a dataframe

If the question isn't just "how to access an integer form of the timedelta?" but "how to convert the timedelta column in the dataframe to an int?" the answer might be a little different. In addition to the .dt.days accessor you need either df.astype or pd.to_numeric

Either of these options should help:

df['tdColumn'] = pd.to_numeric(df['tdColumn'].dt.days, downcast='integer')

or

df['tdColumn'] = df['tdColumn'].dt.days.astype('int16')

Npm install failed with "cannot run in wd"

I fixed this by changing the ownership of /usr/local and ~/Users/user-name like so:

sudo chown -R my_name /usr/local

This allowed me to do everything without sudo

C# testing to see if a string is an integer?

Maybe this can be another solution 

try
{
    Console.Write("write your number : ");
    Console.WriteLine("Your number is : " + int.Parse(Console.ReadLine()));
}
catch (Exception x)
{
    Console.WriteLine(x.Message);
}
Console.ReadLine();

Passing parameters in Javascript onClick event

 
link.onclick = function() { onClickLink(i+''); };

Is a closure and stores a reference to the variable i, not the value that i holds when the function is created. One solution would be to wrap the contents of the for loop in a function do this:

for (var i = 0; i < 10; i++) (function(i) {
    var link = document.createElement('a');
    link.setAttribute('href', '#');
    link.innerHTML = i + '';
    link.onclick=  function() { onClickLink(i+'');};
    div.appendChild(link);
    div.appendChild(document.createElement('BR'));
}(i));

What can cause a “Resource temporarily unavailable” on sock send() command

Let'e me give an example:

  1. client connect to server, and send 1MB data to server every 1 second.

  2. server side accept a connection, and then sleep 20 second, without recv msg from client.So the tcp send buffer in the client side will be full.

Code in client side:

#include <arpa/inet.h>
#include <sys/socket.h>
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#define exit_if(r, ...)                                                                          \
    if (r) {                                                                                     \
        printf(__VA_ARGS__);                                                                     \
        printf("%s:%d error no: %d error msg %s\n", __FILE__, __LINE__, errno, strerror(errno)); \
        exit(1);                                                                                 \
    }

void setNonBlock(int fd) {
    int flags = fcntl(fd, F_GETFL, 0);
    exit_if(flags < 0, "fcntl failed");
    int r = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
    exit_if(r < 0, "fcntl failed");
}

void test_full_sock_buf_1(){
    short port = 8000;
    struct sockaddr_in addr;
    memset(&addr, 0, sizeof addr);
    addr.sin_family = AF_INET;
    addr.sin_port = htons(port);
    addr.sin_addr.s_addr = INADDR_ANY;


    int fd = socket(AF_INET, SOCK_STREAM, 0);
    exit_if(fd<0, "create socket error");

    int ret = connect(fd, (struct sockaddr *) &addr, sizeof(struct sockaddr));
    exit_if(ret<0, "connect to server error");
    setNonBlock(fd);

    printf("connect to server success");

    const int LEN = 1024 * 1000;
    char msg[LEN];  // 1MB data
    memset(msg, 'a', LEN);

    for (int i = 0; i < 1000; ++i) {
        int len = send(fd, msg, LEN, 0);
        printf("send: %d, erron: %d, %s \n", len, errno, strerror(errno));
        sleep(1);
    }

}

int main(){
    test_full_sock_buf_1();

    return 0;
}

Code in server side:

    #include <arpa/inet.h>
    #include <sys/socket.h>
    #include <stdio.h>
    #include <errno.h>
    #include <fcntl.h>
    #include <stdlib.h>
    #include <string.h>
    #define exit_if(r, ...)                                                                          \
        if (r) {                                                                                     \
            printf(__VA_ARGS__);                                                                     \
            printf("%s:%d error no: %d error msg %s\n", __FILE__, __LINE__, errno, strerror(errno)); \
            exit(1);                                                                                 \
        }
void test_full_sock_buf_1(){

    int listenfd = socket(AF_INET, SOCK_STREAM, 0);
    exit_if(listenfd<0, "create socket error");

    short port = 8000;
    struct sockaddr_in addr;
    memset(&addr, 0, sizeof addr);
    addr.sin_family = AF_INET;
    addr.sin_port = htons(port);
    addr.sin_addr.s_addr = INADDR_ANY;

    int r = ::bind(listenfd, (struct sockaddr *) &addr, sizeof(struct sockaddr));
    exit_if(r<0, "bind socket error");

    r = listen(listenfd, 100);
    exit_if(r<0, "listen socket error");

    struct sockaddr_in raddr;
    socklen_t rsz = sizeof(raddr);
    int cfd = accept(listenfd, (struct sockaddr *) &raddr, &rsz);
    exit_if(cfd<0, "accept socket error");

    sockaddr_in peer;
    socklen_t alen = sizeof(peer);
    getpeername(cfd, (sockaddr *) &peer, &alen);

    printf("accept a connection from %s:%d\n", inet_ntoa(peer.sin_addr), ntohs(peer.sin_port));

    printf("but now I will sleep 15 second, then exit");
    sleep(15);
}

Start server side, then start client side.

server side may output:

accept a connection from 127.0.0.1:35764
but now I will sleep 15 second, then exit
Process finished with exit code 0

enter image description here

client side may output:

connect to server successsend: 1024000, erron: 0, Success 
send: 1024000, erron: 0, Success 
send: 1024000, erron: 0, Success 
send: 552190, erron: 0, Success 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 11, Resource temporarily unavailable 
send: -1, erron: 104, Connection reset by peer 
send: -1, erron: 32, Broken pipe 
send: -1, erron: 32, Broken pipe 
send: -1, erron: 32, Broken pipe 
send: -1, erron: 32, Broken pipe 
send: -1, erron: 32, Broken pipe

enter image description here

You can see, as the server side doesn't recv the data from client, so when the client side tcp buffer get full, but you still send data, so you may get Resource temporarily unavailable error.

How do I add a delay in a JavaScript loop?

This will work

for (var i = 0; i < 10; i++) {
  (function(i) {
    setTimeout(function() { console.log(i); }, 100 * i);
  })(i);
}

Try this fiddle: https://jsfiddle.net/wgdx8zqq/

Specify a Root Path of your HTML directory for script links?

/ means the root of the current drive;

./ means the current directory;

../ means the parent of the current directory.

List of encodings that Node.js supports

The encodings are spelled out in the buffer documentation.

Buffers and character encodings:

Character Encodings

  • utf8: Multi-byte encoded Unicode characters. Many web pages and other document formats use UTF-8. This is the default character encoding.
  • utf16le: Multi-byte encoded Unicode characters. Unlike utf8, each character in the string will be encoded using either 2 or 4 bytes.
  • latin1: Latin-1 stands for ISO-8859-1. This character encoding only supports the Unicode characters from U+0000 to U+00FF.

Binary-to-Text Encodings

  • base64: Base64 encoding. When creating a Buffer from a string, this encoding will also correctly accept "URL and Filename Safe Alphabet" as specified in RFC 4648, Section 5.
  • hex: Encode each byte as two hexadecimal characters.

Legacy Character Encodings

  • ascii: For 7-bit ASCII data only. Generally, there should be no reason to use this encoding, as 'utf8' (or, if the data is known to always be ASCII-only, 'latin1') will be a better choice when encoding or decoding ASCII-only text.
  • binary: Alias for 'latin1'.
  • ucs2: Alias of 'utf16le'.

Find PHP version on windows command line
  1. First open your cmd

  2. Then go to php folder directory, Suppose your php folder is in xampp folder on your c drive. Your command would then be:

    cd c:\xampp\php

  3. After that, check your version:

    php -v

This should give the following output:

PHP 7.2.0 (cli) (built: Nov 29 2017 00:17:00) ( ZTS MSVC15 (Visual C++ 2017) x86 ) Copyright (c) 1997-2017 The PHP Group Zend Engine v3.2.0, Copyright (c) 1998-2017 Zend Technologies

I have uploaded a youtube video myself about checking the version of PHP via command prompt in Bangla: https://www.youtube.com/watch?v=zVkhD_tv9ck

Appending to an empty DataFrame in Pandas?

That should work:

>>> df = pd.DataFrame()
>>> data = pd.DataFrame({"A": range(3)})
>>> df.append(data)
   A
0  0
1  1
2  2

But the append doesn't happen in-place, so you'll have to store the output if you want it:

>>> df
Empty DataFrame
Columns: []
Index: []
>>> df = df.append(data)
>>> df
   A
0  0
1  1
2  2

Can a WSDL indicate the SOAP version (1.1 or 1.2) of the web service?

I have found this page

http://schemas.xmlsoap.org/wsdl/soap12/soap12WSDL.htm

which says that Soap 1.2 uses the new namespace http://schemas.xmlsoap.org/wsdl/soap12/

It is in the 'WSDL 1.1 Binding extension for SOAP 1.1'.

How to check if an int is a null

An int is not null, it may be 0 if not initialized.

If you want an integer to be able to be null, you need to use Integer instead of int.

Integer id;
String name;

public Integer getId() { return id; }

Besides the statement if(person.equals(null)) can't be true, because if person is null, then a NullPointerException will be thrown. So the correct expression is if (person == null)

SQL: How to get the id of values I just INSERTed?

Simplest answer:

command.ExecuteScalar()

by default returns the first column

Return Value Type: System.Object The first column of the first row in the result set, or a null reference (Nothing in Visual Basic) if the result set is empty. Returns a maximum of 2033 characters.

Copied from MSDN

Still Reachable Leak detected by Valgrind

Since there is some routine from the the pthread family on the bottom (but I don't know that particular one), my guess would be that you have launched some thread as joinable that has terminated execution.

The exit state information of that thread is kept available until you call pthread_join. Thus, the memory is kept in a loss record at program termination, but it is still reachable since you could use pthread_join to access it.

If this analysis is correct, either launch these threads detached, or join them before terminating your program.

Edit: I ran your sample program (after some obvious corrections) and I don't have errors but the following

==18933== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 4 from 4)
--18933-- 
--18933-- used_suppression:      2 dl-hack3-cond-1
--18933-- used_suppression:      2 glibc-2.5.x-on-SUSE-10.2-(PPC)-2a

Since the dl- thing resembles much of what you see I guess that you see a known problem that has a solution in terms of a suppression file for valgrind. Perhaps your system is not up to date, or your distribution doesn't maintain these things. (Mine is ubuntu 10.4, 64bit)

Extract specific columns from delimited file using Awk

If Perl is an option:

perl -F, -lane 'print join ",",@F[0,1,2,3,4,5,6,7,8,9,19,20,21,22,23,24,29,32]'

-a autosplits line into @F fields array. Indices start at 0 (not 1 as in awk)
-F, field separator is ,

If your CSV file contains commas within quotes, fully fledged CSV parsers such as Perl's Text::CSV_XS are purpose-built to handle that kind of weirdness.

perl -MText::CSV_XS -lne 'BEGIN{$csv=Text::CSV_XS->new()} if($csv->parse($_)){@f=$csv->fields();print (join ",",@f[0,1,2,3,4,5,6,7,8,9,19,20,21,22,23,24,29,32])}'

I provided more explanation within my answer here: parse csv file using gawk

selectOneMenu ajax events

I'd rather use more convenient itemSelect event. With this event you can use org.primefaces.event.SelectEvent objects in your listener.

<p:selectOneMenu ...>
    <p:ajax event="itemSelect" 
        update="messages"
        listener="#{beanMB.onItemSelectedListener}"/>
</p:selectOneMenu>

With such listener:

public void onItemSelectedListener(SelectEvent event){
    MyItem selectedItem = (MyItem) event.getObject();
    //do something with selected value
}

What is ADT? (Abstract Data Type)

Abstract data type is the collection of values and any kind of operation on these values. For example, since String is not a primitive data type, we can include it in abstract data types.

Pure CSS to make font-size responsive based on dynamic amount of characters

For reference, a non-CSS solution:

Below is some JS that re-sizes a font depending on the text length within a container.

Codepen with slightly modified code, but same idea as below:

function scaleFontSize(element) {
    var container = document.getElementById(element);

    // Reset font-size to 100% to begin
    container.style.fontSize = "100%";

    // Check if the text is wider than its container,
    // if so then reduce font-size
    if (container.scrollWidth > container.clientWidth) {
        container.style.fontSize = "70%";
    }
}

For me, I call this function when a user makes a selection in a drop-down, and then a div in my menu gets populated (this is where I have dynamic text occurring).

    scaleFontSize("my_container_div");

In addition, I also use CSS ellipses ("...") to truncate yet even longer text too, like so:

#my_container_div {
    width: 200px; /* width required for text-overflow to work */
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

So, ultimately:

  • Short text: e.g. "APPLES"

    Fully rendered, nice big letters.

  • Long text: e.g. "APPLES & ORANGES"

    Gets scaled down 70%, via the above JS scaling function.

  • Super long text: e.g. "APPLES & ORANGES & BANAN..."

    Gets scaled down 70% AND gets truncated with a "..." ellipses, via the above JS scaling function together with the CSS rule.

You could also explore playing with CSS letter-spacing to make text narrower while keeping the same font size.

Sorting Python list based on the length of the string

 
def lensort(list_1):
    list_2=[];list_3=[]
for i in list_1:
    list_2.append([i,len(i)])
list_2.sort(key = lambda x : x[1])
for i in list_2:
    list_3.append(i[0])
return list_3

This works for me!

div with dynamic min-height based on browser window height

As mentioned elsewhere, the CSS function calc() can work nicely here. It is now mostly supported. You could use like:

.container
{
    min-height: 70%;
    min-height: -webkit-calc(100% - 300px);
    min-height: -moz-calc(100% - 300px);
    min-height: calc(100% - 300px);
}

Run Android studio emulator on AMD processor

The very first thing you need to do is download extras and tools package from SDK manager and other necessary packages like platform-25 and so on.. , after that open AVD manager and select any emulator you wan't, after that go to "other images" tab and select ARM AEBI a7a System Image and select finish and you are all done hope this would help you.

"Unable to acquire application service" error while launching Eclipse

I tried all the methods proposed here. I finally deleted the eclipse folder, extracted it again and now everything works perfectly.

import httplib ImportError: No module named httplib

You are running Python 2 code on Python 3. In Python 3, the module has been renamed to http.client.

You could try to run the 2to3 tool on your code, and try to have it translated automatically. References to httplib will automatically be rewritten to use http.client instead.

notifyDataSetChanged example

I know this is a late response but I was facing a similar issue and I managed to solve it by using notifyDataSetChanged() in the right place.

So my situation was as follows.

I had to update a listview in an action bar tab (fragment) with contents returned from a completely different activity. Initially however, the listview would not reflect any changes. However, when I clicked another tab and then returned to the desired tab,the listview would be updated with the correct content from the other activity. So to solve this I used notifyDataSetChanged() of the action bar adapter in the code of the activity which had to return the data.

This is the code snippet which I used in the activity. 

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    switch (item.getItemId()) 
    {
        case R.id.action_new_forward:

            FragmentTab2.mListAdapter.notifyDataSetChanged();//this updates the adapter in my action bar tab
            Intent ina = new Intent(getApplicationContext(), MainActivity.class);
            ina.putExtra("stra", values1);
            startActivity(ina);// This is the code to start the parent activity of my action bar tab(fragment).
    }
}

This activity would return some data to FragmentTab2 and it would directly update my listview in FragmentTab2.

Hope someone finds this useful!