Programs & Examples On #Userland

Docker Error bind: address already in use

I had same problem, docker-compose down --rmi all (in the same directory where you run docker-compose up) helps

UPD: CAUTION - this will also delete the local docker images you've pulled (from comment)

Iterating a JavaScript object's properties using jQuery

Late, but can be done by using Object.keys like,

_x000D_
_x000D_
var a={key1:'value1',key2:'value2',key3:'value3',key4:'value4'},_x000D_
  ulkeys=document.getElementById('object-keys'),str='';_x000D_
var keys = Object.keys(a);_x000D_
for(i=0,l=keys.length;i<l;i++){_x000D_
   str+= '<li>'+keys[i]+' : '+a[keys[i]]+'</li>';_x000D_
}_x000D_
ulkeys.innerHTML=str;
_x000D_
<ul id="object-keys"></ul>
_x000D_
_x000D_
_x000D_

How to find the path of the local git repository when I am possibly in a subdirectory

git rev-parse --show-toplevel

could be enough if executed within a git repo.
From git rev-parse man page:

--show-toplevel

Show the absolute path of the top-level directory.

For older versions (before 1.7.x), the other options are listed in "Is there a way to get the git root directory in one command?":

git rev-parse --git-dir

That would give the path of the .git directory.


The OP mentions:

git rev-parse --show-prefix

which returns the local path under the git repo root. (empty if you are at the git repo root)


Note: for simply checking if one is in a git repo, I find the following command quite expressive:

git rev-parse --is-inside-work-tree

And yes, if you need to check if you are in a .git git-dir folder:

git rev-parse --is-inside-git-dir

Program to find largest and smallest among 5 numbers without using array

#include <algorithm>
#include <iostream>

template <typename T>
inline const T&
max_of(const T& a, const T& b) {
    return std::max(a, b);
}

template <typename T, typename ...Args>
inline const T&
max_of(const T& a, const T& b, const Args& ...args) {
    return max_of(std::max(a, b), args...);
}

int main() {
    std::cout << max_of(1, 2, 3, 4, 5) << std::endl;
    // Or just use the std library:
    std::cout << std::max({1, 2, 3, 4, 5}) << std::endl;
    return 0;
}

What is the proper use of an EventEmitter?

Yes, go ahead and use it.

EventEmitter is a public, documented type in the final Angular Core API. Whether or not it is based on Observable is irrelevant; if its documented emit and subscribe methods suit what you need, then go ahead and use it.

As also stated in the docs:

Uses Rx.Observable but provides an adapter to make it work as specified here: https://github.com/jhusain/observable-spec

Once a reference implementation of the spec is available, switch to it.

So they wanted an Observable like object that behaved in a certain way, they implemented it, and made it public. If it were merely an internal Angular abstraction that shouldn't be used, they wouldn't have made it public.

There are plenty of times when it's useful to have an emitter which sends events of a specific type. If that's your use case, go for it. If/when a reference implementation of the spec they link to is available, it should be a drop-in replacement, just as with any other polyfill.

Just be sure that the generator you pass to the subscribe() function follows the linked spec. The returned object is guaranteed to have an unsubscribe method which should be called to free any references to the generator (this is currently an RxJs Subscription object but that is indeed an implementation detail which should not be depended on).

export class MyServiceEvent {
    message: string;
    eventId: number;
}

export class MyService {
    public onChange: EventEmitter<MyServiceEvent> = new EventEmitter<MyServiceEvent>();

    public doSomething(message: string) {
        // do something, then...
        this.onChange.emit({message: message, eventId: 42});
    }
}

export class MyConsumer {
    private _serviceSubscription;

    constructor(private service: MyService) {
        this._serviceSubscription = this.service.onChange.subscribe({
            next: (event: MyServiceEvent) => {
                console.log(`Received message #${event.eventId}: ${event.message}`);
            }
        })
    }

    public consume() {
        // do some stuff, then later...

        this.cleanup();
    }

    private cleanup() {
        this._serviceSubscription.unsubscribe();
    }
}

All of the strongly-worded doom and gloom predictions seem to stem from a single Stack Overflow comment from a single developer on a pre-release version of Angular 2.

How to convert time milliseconds to hours, min, sec format in JavaScript?

I needed time only up to one day, 24h, this was my take:

_x000D_
_x000D_
const milliseconds = 5680000;_x000D_
_x000D_
const hours = `0${new Date(milliseconds).getHours() - 1}`.slice(-2);_x000D_
const minutes = `0${new Date(milliseconds).getMinutes()}`.slice(-2);_x000D_
const seconds = `0${new Date(milliseconds).getSeconds()}`.slice(-2);_x000D_
_x000D_
const time = `${hours}:${minutes}:${seconds}`_x000D_
console.log(time);
_x000D_
_x000D_
_x000D_

you could get days this way as well if needed.

I can't delete a remote master branch on git

As explained in "Deleting your master branch" by Matthew Brett, you need to change your GitHub repo default branch.

You need to go to the GitHub page for your forked repository, and click on the “Settings” button.

Click on the "Branches" tab on the left hand side. There’s a “Default branch” dropdown list near the top of the screen.

From there, select placeholder (where placeholder is the dummy name for your new default branch).

Confirm that you want to change your default branch.

Now you can do (from the command line):

git push origin :master

Or, since 2012, you can delete that same branch directly on GitHub:

GitHub deletion

That was announced in Sept. 2013, a year after I initially wrote that answer.

For small changes like documentation fixes, typos, or if you’re just a walking software compiler, you can get a lot done in your browser without needing to clone the entire repository to your computer.


Note: for BitBucket, Tum reports in the comments:

About the same for Bitbucket

Repo -> Settings -> Repository details -> Main branch

Restore the mysql database from .frm files

Copy all file and replace to /var/lib/mysql , after that you must change owner of files to mysql this is so important if mariadb.service restart has been faild

chown -R mysql:mysql /var/lib/mysql/*

and

chmod -R 700 /var/lib/mysql/*

Why do I have ORA-00904 even when the column is present?

Check the username credential used to login to the database. (persistence.xml ??). The problem mostly is, the username\password used to login to the database, does not have visiblity to the object (table_name in this case). ( try logging in to sql developer, using the same username\password available in your data source)

What does -> mean in Python function definitions?

As other answers have stated, the -> symbol is used as part of function annotations. In more recent versions of Python >= 3.5, though, it has a defined meaning.

PEP 3107 -- Function Annotations described the specification, defining the grammar changes, the existence of func.__annotations__ in which they are stored and, the fact that it's use case is still open.

In Python 3.5 though, PEP 484 -- Type Hints attaches a single meaning to this: -> is used to indicate the type that the function returns. It also seems like this will be enforced in future versions as described in What about existing uses of annotations:

The fastest conceivable scheme would introduce silent deprecation of non-type-hint annotations in 3.6, full deprecation in 3.7, and declare type hints as the only allowed use of annotations in Python 3.8.

(Emphasis mine)

This hasn't been actually implemented as of 3.6 as far as I can tell so it might get bumped to future versions.

According to this, the example you've supplied:

def f(x) -> 123:
    return x

will be forbidden in the future (and in current versions will be confusing), it would need to be changed to:

def f(x) -> int:
    return x

for it to effectively describe that function f returns an object of type int.

The annotations are not used in any way by Python itself, it pretty much populates and ignores them. It's up to 3rd party libraries to work with them.

Error in spring application context schema

I have recently had same issue with JPA-1.3

Nothing worked until I used explicit tools.xsd link

xsi:schemaLocation=" ...
    http://www.springframework.org/schema/tool
    http://www.springframework.org/schema/tool/spring-tool-3.2.xsd
    ... ">

like this:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:p="http://www.springframework.org/schema/p" 
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:jdbc="http://www.springframework.org/schema/jdbc"
    xmlns:jpa="http://www.springframework.org/schema/data/jpa"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans 
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
        http://www.springframework.org/schema/tx 
        http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
        http://www.springframework.org/schema/jdbc 
        http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
        http://www.springframework.org/schema/data/jpa
        http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
        http://www.springframework.org/schema/tool
        http://www.springframework.org/schema/tool/spring-tool-3.2.xsd
        ">

Given a filesystem path, is there a shorter way to extract the filename without its extension?

try

System.IO.Path.GetFileNameWithoutExtension(path); 

demo

string fileName = @"C:\mydir\myfile.ext";
string path = @"C:\mydir\";
string result;

result = Path.GetFileNameWithoutExtension(fileName);
Console.WriteLine("GetFileNameWithoutExtension('{0}') returns '{1}'", 
    fileName, result);

result = Path.GetFileName(path);
Console.WriteLine("GetFileName('{0}') returns '{1}'", 
    path, result);

// This code produces output similar to the following:
//
// GetFileNameWithoutExtension('C:\mydir\myfile.ext') returns 'myfile'
// GetFileName('C:\mydir\') returns ''

https://msdn.microsoft.com/en-gb/library/system.io.path.getfilenamewithoutextension%28v=vs.80%29.aspx

What is the difference between static_cast<> and C style casting?

See A comparison of the C++ casting operators.

However, using the same syntax for a variety of different casting operations can make the intent of the programmer unclear.

Furthermore, it can be difficult to find a specific type of cast in a large codebase.

the generality of the C-style cast can be overkill for situations where all that is needed is a simple conversion. The ability to select between several different casting operators of differing degrees of power can prevent programmers from inadvertently casting to an incorrect type.

Composer install error - requires ext_curl when it's actually enabled

I ran into a similar issue when trying to get composer to install some dependencies. It turns out the .dll my version of Wamp came with had a conflict, I am guessing, with 64 bit Windows.

This url has fixed curl dlls: http://www.anindya.com/php-5-4-3-and-php-5-3-13-x64-64-bit-for-windows/

Scroll down to the section that says: Fixed Curl Extensions.

I downloaded "php_curl-5.4.3-VC9-x64.zip". I just overwrote the dll inside the wamp/bin/php/php5.4.3/ext directory with the dll that was in the zip file and composer worked again.

I am running 64 bit Windows 8.

Hope this helps.

Start redis-server with config file

Okay, redis is pretty user friendly but there are some gotchas.

Here are just some easy commands for working with redis on Ubuntu:

install:

sudo apt-get install redis-server

start with conf:

sudo redis-server <path to conf>
sudo redis-server config/redis.conf

stop with conf:

redis-ctl shutdown

(not sure how this shuts down the pid specified in the conf. Redis must save the path to the pid somewhere on boot)

log:

tail -f /var/log/redis/redis-server.log

Also, various example confs floating around online and on this site were beyond useless. The best, sure fire way to get a compatible conf is to copy-paste the one your installation is already using. You should be able to find it here:

/etc/redis/redis.conf

Then paste it at <path to conf>, tweak as needed and you're good to go.

Learning Regular Expressions

The most important part is the concepts. Once you understand how the building blocks work, differences in syntax amount to little more than mild dialects. A layer on top of your regular expression engine's syntax is the syntax of the programming language you're using. Languages such as Perl remove most of this complication, but you'll have to keep in mind other considerations if you're using regular expressions in a C program.

If you think of regular expressions as building blocks that you can mix and match as you please, it helps you learn how to write and debug your own patterns but also how to understand patterns written by others.

Start simple

Conceptually, the simplest regular expressions are literal characters. The pattern N matches the character 'N'.

Regular expressions next to each other match sequences. For example, the pattern Nick matches the sequence 'N' followed by 'i' followed by 'c' followed by 'k'.

If you've ever used grep on Unix—even if only to search for ordinary looking strings—you've already been using regular expressions! (The re in grep refers to regular expressions.)

Order from the menu

Adding just a little complexity, you can match either 'Nick' or 'nick' with the pattern [Nn]ick. The part in square brackets is a character class, which means it matches exactly one of the enclosed characters. You can also use ranges in character classes, so [a-c] matches either 'a' or 'b' or 'c'.

The pattern . is special: rather than matching a literal dot only, it matches any character. It's the same conceptually as the really big character class [-.?+%$A-Za-z0-9...].

Think of character classes as menus: pick just one.

Helpful shortcuts

Using . can save you lots of typing, and there are other shortcuts for common patterns. Say you want to match a digit: one way to write that is [0-9]. Digits are a frequent match target, so you could instead use the shortcut \d. Others are \s (whitespace) and \w (word characters: alphanumerics or underscore).

The uppercased variants are their complements, so \S matches any non-whitespace character, for example.

Once is not enough

From there, you can repeat parts of your pattern with quantifiers. For example, the pattern ab?c matches 'abc' or 'ac' because the ? quantifier makes the subpattern it modifies optional. Other quantifiers are

  • * (zero or more times)
  • + (one or more times)
  • {n} (exactly n times)
  • {n,} (at least n times)
  • {n,m} (at least n times but no more than m times)

Putting some of these blocks together, the pattern [Nn]*ick matches all of

  • ick
  • Nick
  • nick
  • Nnick
  • nNick
  • nnick
  • (and so on)

The first match demonstrates an important lesson: * always succeeds! Any pattern can match zero times.

A few other useful examples:

  • [0-9]+ (and its equivalent \d+) matches any non-negative integer
  • \d{4}-\d{2}-\d{2} matches dates formatted like 2019-01-01

Grouping

A quantifier modifies the pattern to its immediate left. You might expect 0abc+0 to match '0abc0', '0abcabc0', and so forth, but the pattern immediately to the left of the plus quantifier is c. This means 0abc+0 matches '0abc0', '0abcc0', '0abccc0', and so on.

To match one or more sequences of 'abc' with zeros on the ends, use 0(abc)+0. The parentheses denote a subpattern that can be quantified as a unit. It's also common for regular expression engines to save or "capture" the portion of the input text that matches a parenthesized group. Extracting bits this way is much more flexible and less error-prone than counting indices and substr.

Alternation

Earlier, we saw one way to match either 'Nick' or 'nick'. Another is with alternation as in Nick|nick. Remember that alternation includes everything to its left and everything to its right. Use grouping parentheses to limit the scope of |, e.g., (Nick|nick).

For another example, you could equivalently write [a-c] as a|b|c, but this is likely to be suboptimal because many implementations assume alternatives will have lengths greater than 1.

Escaping

Although some characters match themselves, others have special meanings. The pattern \d+ doesn't match backslash followed by lowercase D followed by a plus sign: to get that, we'd use \\d\+. A backslash removes the special meaning from the following character.

Greediness

Regular expression quantifiers are greedy. This means they match as much text as they possibly can while allowing the entire pattern to match successfully.

For example, say the input is

"Hello," she said, "How are you?"

You might expect ".+" to match only 'Hello,' and will then be surprised when you see that it matched from 'Hello' all the way through 'you?'.

To switch from greedy to what you might think of as cautious, add an extra ? to the quantifier. Now you understand how \((.+?)\), the example from your question works. It matches the sequence of a literal left-parenthesis, followed by one or more characters, and terminated by a right-parenthesis.

If your input is '(123) (456)', then the first capture will be '123'. Non-greedy quantifiers want to allow the rest of the pattern to start matching as soon as possible.

(As to your confusion, I don't know of any regular-expression dialect where ((.+?)) would do the same thing. I suspect something got lost in transmission somewhere along the way.)

Anchors

Use the special pattern ^ to match only at the beginning of your input and $ to match only at the end. Making "bookends" with your patterns where you say, "I know what's at the front and back, but give me everything between" is a useful technique.

Say you want to match comments of the form

-- This is a comment --

you'd write ^--\s+(.+)\s+--$.

Build your own

Regular expressions are recursive, so now that you understand these basic rules, you can combine them however you like.

Tools for writing and debugging regexes:

Books

Free resources

Footnote

†: The statement above that . matches any character is a simplification for pedagogical purposes that is not strictly true. Dot matches any character except newline, "\n", but in practice you rarely expect a pattern such as .+ to cross a newline boundary. Perl regexes have a /s switch and Java Pattern.DOTALL, for example, to make . match any character at all. For languages that don't have such a feature, you can use something like [\s\S] to match "any whitespace or any non-whitespace", in other words anything.

Converting HTML files to PDF

The Flying Saucer XHTML renderer project has support for outputting XHTML to PDF. Have a look at an example here.

PHP array delete by value (not key)

I think the simplest way would be to use a function with a foreach loop:

//This functions deletes the elements of an array $original that are equivalent to the value $del_val
//The function works by reference, which means that the actual array used as parameter will be modified.

function delete_value(&$original, $del_val)
{
    //make a copy of the original, to avoid problems of modifying an array that is being currently iterated through
    $copy = $original;
    foreach ($original as $key => $value)
    {
        //for each value evaluate if it is equivalent to the one to be deleted, and if it is capture its key name.
        if($del_val === $value) $del_key[] = $key;
    };
    //If there was a value found, delete all its instances
    if($del_key !== null)
    {
        foreach ($del_key as $dk_i)
        {
            unset($original[$dk_i]);
        };
        //optional reordering of the keys. WARNING: only use it with arrays with numeric indexes!
        /*
        $copy = $original;
        $original = array();
        foreach ($copy as $value) {
            $original[] = $value;
        };
        */
        //the value was found and deleted
        return true;
    };
    //The value was not found, nothing was deleted
    return false;
};

$original = array(0,1,2,3,4,5,6,7,4);
$del_val = 4;
var_dump($original);
delete_value($original, $del_val);
var_dump($original);

Output will be:

array(9) {
  [0]=>
  int(0)
  [1]=>
  int(1)
  [2]=>
  int(2)
  [3]=>
  int(3)
  [4]=>
  int(4)
  [5]=>
  int(5)
  [6]=>
  int(6)
  [7]=>
  int(7)
  [8]=>
  int(4)
}
array(7) {
  [0]=>
  int(0)
  [1]=>
  int(1)
  [2]=>
  int(2)
  [3]=>
  int(3)
  [5]=>
  int(5)
  [6]=>
  int(6)
  [7]=>
  int(7)
}

Fast query runs slow in SSRS

I simply deselected 'Repeat header columns on each page' within the Tablix Properties.

View list of all JavaScript variables in Google Chrome Console

When script execution is halted (e.g., on a breakpoint) you can simply view all globals in the right pane of the Developer Tools window:

chrome-globals

How to get root view controller?

Unless you have a good reason, in your root controller do this:

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(onTheEvent:)
                                             name:@"ABCMyEvent"
                                           object:nil];

And when you want to notify it:

[[NSNotificationCenter defaultCenter] postNotificationName:@"ABCMyEvent"
                                                object:self];                

Which exception should I raise on bad/illegal argument combinations in Python?

I've mostly just seen the builtin ValueError used in this situation.

How to reload current page in ReactJS?

Since React eventually boils down to plain old JavaScript, you can really place it anywhere! For instance, you could place it on a componentDidMount() in a React class.

For you edit, you may want to try something like this:

class Component extends React.Component {
  constructor(props) {
    super(props);
    this.onAddBucket = this.onAddBucket.bind(this);
  }
  componentWillMount() {
    this.setState({
      buckets: {},
    })
  }
  componentDidMount() {
    this.onAddBucket();
  }
  onAddBucket() {
    let self = this;
    let getToken = localStorage.getItem('myToken');
    var apiBaseUrl = "...";
    let input = {
      "name" :  this.state.fields["bucket_name"]
    }
    axios.defaults.headers.common['Authorization'] = getToken;
    axios.post(apiBaseUrl+'...',input)
    .then(function (response) {
      if (response.data.status == 200) {
        this.setState({
          buckets: this.state.buckets.concat(response.data.buckets),
        });
      } else {
        alert(response.data.message);
      }
    })
    .catch(function (error) {
      console.log(error);
    });
  }
  render() {
    return (
      {this.state.bucket}
    );
  }
}

Left Outer Join using + sign in Oracle 11g

I saw some contradictions in the answers above, I just tried the following on Oracle 12c and the following is correct :

LEFT OUTER JOIN

SELECT *
FROM A, B
WHERE A.column = B.column(+)

RIGHT OUTER JOIN

SELECT *
FROM A, B
WHERE B.column(+) = A.column

java.lang.NoSuchMethodError: javax.servlet.ServletContext.getContextPath()Ljava/lang/String;

java.lang.NoSuchMethodError: javax.servlet.ServletContext.getContextPath()Ljava/lang/String;

That method was added in Servlet 2.5.

So this problem can have at least 3 causes:

  1. The servlet container does not support Servlet 2.5.
  2. The web.xml is not declared conform Servlet 2.5 or newer.
  3. The webapp's runtime classpath is littered with servlet container specific JAR files of a different servlet container make/version which does not support Servlet 2.5.

To solve it,

  1. Make sure that your servlet container supports at least Servlet 2.5. That are at least Tomcat 6, Glassfish 2, JBoss AS 4.1, etcetera. Tomcat 5.5 for example supports at highest Servlet 2.4. If you can't upgrade Tomcat, then you'd need to downgrade Spring to a Servlet 2.4 compatible version.
  2. Make sure that the root declaration of web.xml complies Servlet 2.5 (or newer, at least the highest whatever your target runtime supports). For an example, see also somewhere halfway our servlets wiki page.
  3. Make sure that you don't have any servlet container specific libraries like servlet-api.jar or j2ee.jar in /WEB-INF/lib or even worse, the JRE/lib or JRE/lib/ext. They do not belong there. This is a pretty common beginner's mistake in an attempt to circumvent compilation errors in an IDE, see also How do I import the javax.servlet API in my Eclipse project?.

Java constructor/method with optional parameters?

Java doesn't support default parameters. You will need to have two constructors to do what you want.

An alternative if there are lots of possible values with defaults is to use the Builder pattern, whereby you use a helper object with setters.

e.g.

   public class Foo {
     private final String param1;
     private final String param2;

     private Foo(Builder builder) {
       this.param1 = builder.param1;
       this.param2 = builder.param2;
     }
     public static class Builder {
       private String param1 = "defaultForParam1";
       private String param2 = "defaultForParam2";

       public Builder param1(String param1) {
         this.param1 = param1;
         return this;
       }
       public Builder param2(String param1) {
         this.param2 = param2;
         return this;
       }
       public Foo build() {
         return new Foo(this);
       }
     }
   }

which allows you to say:

Foo myFoo = new Foo.Builder().param1("myvalue").build();

which will have a default value for param2.

How do I change the text size in a label widget, python tkinter

Try passing width=200 as additional paramater when creating the Label.

This should work in creating label with specified width.

If you want to change it later, you can use:

label.config(width=200)

As you want to change the size of font itself you can try:

label.config(font=("Courier", 44))

What online brokers offer APIs?

As of this posting it looks like TradeKing is working on an API. Not sure what the future of it is though.

Generating a WSDL from an XSD file

This tool xsd2wsdl part of the Apache CXF project which will generate a minimalist WSDL.

What exactly is a Maven Snapshot and why do we need it?

Maven versions can contain a string literal "SNAPSHOT" to signify that a project is currently under active development.

For example, if your project has a version of “1.0-SNAPSHOT” and you deploy this project’s artifacts to a Maven repository, Maven would expand this version to “1.0-20080207-230803-1” if you were to deploy a release at 11:08 PM on February 7th, 2008 UTC. In other words, when you deploy a snapshot, you are not making a release of a software component; you are releasing a snapshot of a component at a specific time.

So mainly snapshot versions are used for projects under active development. If your project depends on a software component that is under active development, you can depend on a snapshot release, and Maven will periodically attempt to download the latest snapshot from a repository when you run a build. Similarly, if the next release of your system is going to have a version “1.8,” your project would have a “1.8-SNAPSHOT” version until it was formally released.

For example , the following dependency would always download the latest 1.8 development JAR of spring:

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring</artifactId>
        <version>1.8-SNAPSHOT”</version>
    </dependency>

Maven

An example of maven release process

enter image description here

Ignore python multiple return value

This is not a direct answer to the question. Rather it answers this question: "How do I choose a specific function output from many possible options?".

If you are able to write the function (ie, it is not in a library you cannot modify), then add an input argument that indicates what you want out of the function. Make it a named argument with a default value so in the "common case" you don't even have to specify it.

    def fancy_function( arg1, arg2, return_type=1 ):
        ret_val = None
        if( 1 == return_type ):
            ret_val = arg1 + arg2
        elif( 2 == return_type ):
            ret_val = [ arg1, arg2, arg1 * arg2 ]
        else:
            ret_val = ( arg1, arg2, arg1 + arg2, arg1 * arg2 ) 
        return( ret_val )

This method gives the function "advanced warning" regarding the desired output. Consequently it can skip unneeded processing and only do the work necessary to get your desired output. Also because Python does dynamic typing, the return type can change. Notice how the example returns a scalar, a list or a tuple... whatever you like!

add maven repository to build.gradle

You have to add repositories to your build file. For maven repositories you have to prefix repository name with maven{}

repositories {
  maven { url "http://maven.springframework.org/release" }
  maven { url "http://maven.restlet.org" }
  mavenCentral()
}

What does the construct x = x || y mean?

Basically it checks if the value before the || evaluates to true, if yes, it takes this value, if not, it takes the value after the ||.

Values for which it will take the value after the || (as far as i remember):

  • undefined
  • false
  • 0
  • '' (Null or Null string)

C# string reference type?

For curious minds and to complete the conversation: Yes, String is a reference type:

unsafe
{
     string a = "Test";
     string b = a;
     fixed (char* p = a)
     {
          p[0] = 'B';
     }
     Console.WriteLine(a); // output: "Best"
     Console.WriteLine(b); // output: "Best"
}

But note that this change only works in an unsafe block! because Strings are immutable (From MSDN):

The contents of a string object cannot be changed after the object is created, although the syntax makes it appear as if you can do this. For example, when you write this code, the compiler actually creates a new string object to hold the new sequence of characters, and that new object is assigned to b. The string "h" is then eligible for garbage collection.

string b = "h";  
b += "ello";  

And keep in mind that:

Although the string is a reference type, the equality operators (== and !=) are defined to compare the values of string objects, not references.

How to PUT a json object with an array using curl

Your command line should have a -d/--data inserted before the string you want to send in the PUT, and you want to set the Content-Type and not Accept.

curl -H 'Content-Type: application/json' -X PUT -d '[JSON]' \
     http://example.com/service

Using the exact JSON data from the question, the full command line would become:

curl -H 'Content-Type: application/json' -X PUT \
    -d '{"tags":["tag1","tag2"],
         "question":"Which band?",
         "answers":[{"id":"a0","answer":"Answer1"},
                    {"id":"a1","answer":"answer2"}]}' \
    http://example.com/service

Note: JSON data wrapped only for readability, not valid for curl request.

How to change the Text color of Menu item in Android?

Simply add this to your theme

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
        <item name="android:itemTextAppearance">@style/AppTheme.ItemTextStyle</item>
</style>

<style name="AppTheme.ItemTextStyle" parent="@android:style/TextAppearance.Widget.IconMenu.Item">
        <item name="android:textColor">@color/orange_500</item>
</style>

Tested on API 21

Comparing Arrays of Objects in JavaScript

EDIT: You cannot overload operators in current, common browser-based implementations of JavaScript interpreters.

To answer the original question, one way you could do this, and mind you, this is a bit of a hack, simply serialize the two arrays to JSON and then compare the two JSON strings. That would simply tell you if the arrays are different, obviously you could do this to each of the objects within the arrays as well to see which ones were different.

Another option is to use a library which has some nice facilities for comparing objects - I use and recommend MochiKit.


EDIT: The answer kamens gave deserves consideration as well, since a single function to compare two given objects would be much smaller than any library to do what I suggest (although my suggestion would certainly work well enough).

Here is a naïve implemenation that may do just enough for you - be aware that there are potential problems with this implementation:

function objectsAreSame(x, y) {
   var objectsAreSame = true;
   for(var propertyName in x) {
      if(x[propertyName] !== y[propertyName]) {
         objectsAreSame = false;
         break;
      }
   }
   return objectsAreSame;
}

The assumption is that both objects have the same exact list of properties.

Oh, and it is probably obvious that, for better or worse, I belong to the only-one-return-point camp. :)

How link to any local file with markdown syntax?

After messing around with @BringBackCommodore64 answer I figured it out

[link](file:///d:/absolute.md)    # absolute filesystem path
[link](./relative1.md)            # relative to opened file
[link](/relativeToProject.md)     # relative to opened project

All of them tested in Visual Studio Code and working,

Note: The absolute path works in editor but doesn't work in markdown preview mode!

How can I list all cookies for the current page with Javascript?

Many people have already mentioned that document.cookie gets you all the cookies (except http-only ones).

I'll just add a snippet to keep up with the times.

document.cookie.split(';').reduce((cookies, cookie) => {
  const [ name, value ] = cookie.split('=').map(c => c.trim());
  cookies[name] = value;
  return cookies;
}, {});

The snippet will return an object with cookie names as the keys with cookie values as the values.

Slightly different syntax:

document.cookie.split(';').reduce((cookies, cookie) => {
  const [ name, value ] = cookie.split('=').map(c => c.trim());
  return { ...cookies, [name]: value };
}, {});

How to create Python egg file

I think you should use python wheels for distribution instead of egg now.

Wheels are the new standard of python distribution and are intended to replace eggs. Support is offered in pip >= 1.4 and setuptools >= 0.8.

Generate preview image from Video file?

Two ways come to mind:

  • Using a command-line tool like the popular ffmpeg, however you will almost always need an own server (or a very nice server administrator / hosting company) to get that

  • Using the "screenshoot" plugin for the LongTail Video player that allows the creation of manual screenshots that are then sent to a server-side script.

How to check if a string contains only digits in Java

According to Oracle's Java Documentation:

private static final Pattern NUMBER_PATTERN = Pattern.compile(
        "[\\x00-\\x20]*[+-]?(NaN|Infinity|((((\\p{Digit}+)(\\.)?((\\p{Digit}+)?)" +
        "([eE][+-]?(\\p{Digit}+))?)|(\\.((\\p{Digit}+))([eE][+-]?(\\p{Digit}+))?)|" +
        "(((0[xX](\\p{XDigit}+)(\\.)?)|(0[xX](\\p{XDigit}+)?(\\.)(\\p{XDigit}+)))" +
        "[pP][+-]?(\\p{Digit}+)))[fFdD]?))[\\x00-\\x20]*");
boolean isNumber(String s){
return NUMBER_PATTERN.matcher(s).matches()
}

What is "entropy and information gain"?

I can't give you graphics, but maybe I can give a clear explanation.

Suppose we have an information channel, such as a light that flashes once every day either red or green. How much information does it convey? The first guess might be one bit per day. But what if we add blue, so that the sender has three options? We would like to have a measure of information that can handle things other than powers of two, but still be additive (the way that multiplying the number of possible messages by two adds one bit). We could do this by taking log2(number of possible messages), but it turns out there's a more general way.

Suppose we're back to red/green, but the red bulb has burned out (this is common knowledge) so that the lamp must always flash green. The channel is now useless, we know what the next flash will be so the flashes convey no information, no news. Now we repair the bulb but impose a rule that the red bulb may not flash twice in a row. When the lamp flashes red, we know what the next flash will be. If you try to send a bit stream by this channel, you'll find that you must encode it with more flashes than you have bits (50% more, in fact). And if you want to describe a sequence of flashes, you can do so with fewer bits. The same applies if each flash is independent (context-free), but green flashes are more common than red: the more skewed the probability the fewer bits you need to describe the sequence, and the less information it contains, all the way to the all-green, bulb-burnt-out limit.

It turns out there's a way to measure the amount of information in a signal, based on the the probabilities of the different symbols. If the probability of receiving symbol xi is pi, then consider the quantity

-log pi

The smaller pi, the larger this value. If xi becomes twice as unlikely, this value increases by a fixed amount (log(2)). This should remind you of adding one bit to a message.

If we don't know what the symbol will be (but we know the probabilities) then we can calculate the average of this value, how much we will get, by summing over the different possibilities:

I = -Σ pi log(pi)

This is the information content in one flash.

Red bulb burnt out: pred = 0, pgreen=1, I = -(0 + 0)  = 0
Red and green equiprobable: pred = 1/2, pgreen = 1/2, I = -(2 * 1/2 * log(1/2)) = log(2)
Three colors, equiprobable: pi=1/3, I = -(3 * 1/3 * log(1/3)) = log(3)
Green and red, green twice as likely: pred=1/3, pgreen=2/3, I = -(1/3 log(1/3) + 2/3 log(2/3)) = log(3) - 2/3 log(2)

This is the information content, or entropy, of the message. It is maximal when the different symbols are equiprobable. If you're a physicist you use the natural log, if you're a computer scientist you use log2 and get bits.

Reading all files in a directory, store them in objects, and send the object

Another version with Promise's modern method. It's shorter that the others responses based on Promise :

const readFiles = (dirname) => {

  const readDirPr = new Promise( (resolve, reject) => {
    fs.readdir(dirname, 
      (err, filenames) => (err) ? reject(err) : resolve(filenames))
  });

  return readDirPr.then( filenames => Promise.all(filenames.map((filename) => {
      return new Promise ( (resolve, reject) => {
        fs.readFile(dirname + filename, 'utf-8',
          (err, content) => (err) ? reject(err) : resolve(content));
      })
    })).catch( error => Promise.reject(error)))
};

readFiles(sourceFolder)
  .then( allContents => {

    // handle success treatment

  }, error => console.log(error));

Only detect click event on pseudo-element

This is edited answer by Fasoeu with latest CSS3 and JS ES6

Edited demo without using JQuery.

Shortest example of code:

<p><span>Some text</span></p>
p {
    position: relative;
    pointer-events: none;
}
p::before {
    content: "";
    position: absolute;
    pointer-events: auto;
}
p span {
    display: contents;
    pointer-events: auto;
}
const all_p = Array.from(document.querySelectorAll('p'));

for (let p of all_p) {
    p.addEventListener("click", listener, false);
};

Explanation:

pointer-events control detection of events, removing receiving events from target, but keep receiving from pseudo-elements make possible to click on ::before and ::after and you will always know what you are clicking on pseudo-element, however if you still need to click, you put all content in nested element (span in example), but because we don't want to apply any additional styles, display: contents; become very handy solution and it supported by most browsers. pointer-events: none; as already mentioned in original post also widely supported.

The JavaScript part also used widely supported Array.from and for...of, however they are not necessary to use in code.

How to center a View inside of an Android Layout?

You can apply a centering to any View, including a Layout, by using the XML attribute android:layout_gravity". You probably want to give it the value "center".

You can find a reference of possible values for this option here: http://developer.android.com/reference/android/widget/LinearLayout.LayoutParams.html#attr_android:layout_gravity

Padding characters in printf

Pure Bash, no external utilities

This demonstration does full justification, but you can just omit subtracting the length of the second string if you want ragged-right lines.

pad=$(printf '%0.1s' "-"{1..60})
padlength=40
string2='bbbbbbb'
for string1 in a aa aaaa aaaaaaaa
do
     printf '%s' "$string1"
     printf '%*.*s' 0 $((padlength - ${#string1} - ${#string2} )) "$pad"
     printf '%s\n' "$string2"
     string2=${string2:1}
done

Unfortunately, in that technique, the length of the pad string has to be hardcoded to be longer than the longest one you think you'll need, but the padlength can be a variable as shown. However, you can replace the first line with these three to be able to use a variable for the length of the pad:

padlimit=60
pad=$(printf '%*s' "$padlimit")
pad=${pad// /-}

So the pad (padlimit and padlength) could be based on terminal width ($COLUMNS) or computed from the length of the longest data string.

Output:

a--------------------------------bbbbbbb
aa--------------------------------bbbbbb
aaaa-------------------------------bbbbb
aaaaaaaa----------------------------bbbb

Without subtracting the length of the second string:

a---------------------------------------bbbbbbb
aa--------------------------------------bbbbbb
aaaa------------------------------------bbbbb
aaaaaaaa--------------------------------bbbb

The first line could instead be the equivalent (similar to sprintf):

printf -v pad '%0.1s' "-"{1..60}

or similarly for the more dynamic technique:

printf -v pad '%*s' "$padlimit"

You can do the printing all on one line if you prefer:

printf '%s%*.*s%s\n' "$string1" 0 $((padlength - ${#string1} - ${#string2} )) "$pad" "$string2"

Update R using RStudio

If you're using a Mac computer, you can use the new updateR package to update the R version from RStudio: http://www.andreacirillo.com/2018/02/10/updater-package-update-r-version-with-a-function-on-mac-osx/

In summary, you need to perform this:

To update your R version from within Rstudio using updateR you just have to run these five lines of code:

install.packages('devtools') #assuming it is not already installed
library(devtools)
install_github('andreacirilloac/updateR')
library(updateR)
updateR(admin_password = 'Admin user password')

at the end of installation process a message is going to confirm you the happy end:

everything went smoothly
open a Terminal session and run 'R' to assert that latest version was installed

webpack command not working

Actually, I have got this error a while ago. There are two ways to make this to work, as per my knowledge.

  1. Server wont update the changes made in the index.js because of some webpack bugs. So, restart your server.
  2. Updating your node.js will be helpful to avoid such problems.

npm install gives error "can't find a package.json file"

solve using this code:

npm install npm@latest -g

Print commit message of a given commit in git

git show is more a plumbing command than git log, and has the same formatting options:

git show -s --format=%B SHA1

SMTP error 554

To resolve problem go to the MDaemon-->setup-->Miscellaneous options-->Server-->SMTP Server Checks commands and headers for RFC Compliance

How to get only the last part of a path in Python?

Use os.path.normpath, then os.path.basename:

>>> os.path.basename(os.path.normpath('/folderA/folderB/folderC/folderD/'))
'folderD'

The first strips off any trailing slashes, the second gives you the last part of the path. Using only basename gives everything after the last slash, which in this case is ''.

Where does gcc look for C and C++ header files?

In addition, gcc will look in the directories specified after the -I option.


How do I set <table> border width with CSS?

Like this:

border: 1px solid black;

Why it didn't work? because:

Always declare the border-style (solid in my example) property before the border-width property. An element must have borders before you can change the color.

How to make child element higher z-index than parent?

Use non-static position along with greater z-index in child element:

.parent {
    position: absolute
    z-index: 100;
}

.child {
    position: relative;
    z-index: 101;
}

Importing project into Netbeans

From Netbeans 8.1 - there is an "Import from ZIP" option.

Go to Main Menu -> File -> Import Project -> from ZIP.

Browse your .ZIP file's location via Browse button.

If you have Java project depending on external Libraries, Netbeans will highlight & ask for "Resolving problems" in project, click on resolve, provide location in your file system containing required library files .e.g JARs etc & you will be good to go.

Draw line in UIView

You can user UIBezierPath Class for this:

And can draw as many lines as you want:

I have subclassed UIView :

    @interface MyLineDrawingView()
    {
       NSMutableArray *pathArray;
       NSMutableDictionary *dict_path;
       CGPoint startPoint, endPoint;
    }

       @property (nonatomic,retain)   UIBezierPath *myPath;
    @end

And initialized the pathArray and dictPAth objects which will be used for line drawing. I am writing the main portion of the code from my own project:

- (void)drawRect:(CGRect)rect
{

    for(NSDictionary *_pathDict in pathArray)
    {
        [((UIColor *)[_pathDict valueForKey:@"color"]) setStroke]; // this method will choose the color from the receiver color object (in this case this object is :strokeColor)
        [[_pathDict valueForKey:@"path"] strokeWithBlendMode:kCGBlendModeNormal alpha:1.0];
    }

    [[dict_path objectForKey:@"color"] setStroke]; // this method will choose the color from the receiver color object (in this case this object is :strokeColor)
    [[dict_path objectForKey:@"path"] strokeWithBlendMode:kCGBlendModeNormal alpha:1.0];

}

touchesBegin method :

UITouch *touch = [touches anyObject];
startPoint = [touch locationInView:self];
myPath=[[UIBezierPath alloc]init];
myPath.lineWidth = currentSliderValue*2;
dict_path = [[NSMutableDictionary alloc] init];

touchesMoved Method:

UITouch *touch = [touches anyObject];
endPoint = [touch locationInView:self];

 [myPath removeAllPoints];
        [dict_path removeAllObjects];// remove prev object in dict (this dict is used for current drawing, All past drawings are managed by pathArry)

    // actual drawing
    [myPath moveToPoint:startPoint];
    [myPath addLineToPoint:endPoint];

    [dict_path setValue:myPath forKey:@"path"];
    [dict_path setValue:strokeColor forKey:@"color"];

    //                NSDictionary *tempDict = [NSDictionary dictionaryWithDictionary:dict_path];
    //                [pathArray addObject:tempDict];
    //                [dict_path removeAllObjects];
    [self setNeedsDisplay];

touchesEnded Method:

        NSDictionary *tempDict = [NSDictionary dictionaryWithDictionary:dict_path];
        [pathArray addObject:tempDict];
        [dict_path removeAllObjects];
        [self setNeedsDisplay];

Sending emails in Node.js?

Check out emailjs

After wasting lots of time on trying to make nodemailer work with large attachments, found emailjs and happy ever since.

It supports sending files by using normal File objects, and not huge Buffers as nodemailer requires. Means that you can link it to, f.e., formidable to pass the attachments from an html form to the mailer. It also supports queueing..

All in all, no idea why nodejitsu ppl chose nodemailer to base their version on, emailjs is just much more advanced.

Map to String in Java

Use Object#toString().

String string = map.toString();

That's after all also what System.out.println(object) does under the hoods. The format for maps is described in AbstractMap#toString().

Returns a string representation of this map. The string representation consists of a list of key-value mappings in the order returned by the map's entrySet view's iterator, enclosed in braces ("{}"). Adjacent mappings are separated by the characters ", " (comma and space). Each key-value mapping is rendered as the key followed by an equals sign ("=") followed by the associated value. Keys and values are converted to strings as by String.valueOf(Object).

What's a good IDE for Python on Mac OS X?

I usually use either komodo edit or aquamacs with ropemacs. Although I should warn you, IDE features won't be what you're used to if you're coming from a Java or C# background. I personally find that powerful IDEs get in my way more than they help.

UPDATE: I should also point out that if you have the money Komodo IDE is worth it. It's the paid version of Komodo Edit.

how to add jquery in laravel project

you can use online library

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap-theme.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>

or else download library and add css in css folder and jquery in js folder.both folder you keep in laravel public folder then you can link like below

<link rel="stylesheet" href="{{asset('css/bootstrap-theme.min.css')}}">
<script src="{{asset('js/jquery.min.js')}}"></script>

or else

{{ HTML::style('css/style.css') }}
{{ HTML::script('js/functions.js') }}

How to redirect a URL path in IIS?

Here's the config for ISAPI_Rewrite 3:

RewriteBase /

RewriteCond %{HTTP_HOST} ^mysite.org.uk$ [NC]

RewriteRule ^stuff/(.+)$ http://stuff.mysite.org.uk/$1 [NC,R=301,L]

How do I find out my root MySQL password?

You can reset the root password by running the server with --skip-grant-tables and logging in without a password by running the following as root (or with sudo):

# service mysql stop
# mysqld_safe --skip-grant-tables &
$ mysql -u root
mysql> use mysql;
mysql> update user set authentication_string=PASSWORD("YOUR-NEW-ROOT-PASSWORD") where User='root';
mysql> flush privileges;
mysql> quit
# service mysql stop
# service mysql start
$ mysql -u root -p

Now you should be able to login as root with your new password.

It is also possible to find the query that reset the password in /home/$USER/.mysql_history or /root/.mysql_history of the user who reset the password, but the above will always work.

Note: prior to MySQL 5.7 the column was called password instead of authentication_string. Replace the line above with

mysql> update user set password=PASSWORD("YOUR-NEW-ROOT-PASSWORD") where User='root';

Validate Dynamically Added Input fields

In regards to @RitchieD response, here is a jQuery plugin version to make things easier if you are using jQuery.

(function ($) {

    $.fn.initValidation = function () {

        $(this).removeData("validator");
        $(this).removeData("unobtrusiveValidation");
        $.validator.unobtrusive.parse(this);

        return this;
    };

}(jQuery));

This can be used like this:

$("#SomeForm").initValidation();

How to show one layout on top of the other programmatically in my case?

Use a FrameLayout with two children. The two children will be overlapped. This is recommended in one of the tutorials from Android actually, it's not a hack...

Here is an example where a TextView is displayed on top of an ImageView:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent">

  <ImageView  
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 

    android:scaleType="center"
    android:src="@drawable/golden_gate" />

  <TextView
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_marginBottom="20dip"
    android:layout_gravity="center_horizontal|bottom"

    android:padding="12dip"

    android:background="#AA000000"
    android:textColor="#ffffffff"

    android:text="Golden Gate" />

</FrameLayout>

Here is the result

Convert Uppercase Letter to Lowercase and First Uppercase in Sentence using CSS

If use this on capitalized text;

p text-transform: lowercase;

Then show the text, it is lowercase but if you copy that lower-cased text, and paste it, it change back to original capitalized.

sql server #region

I've used a technique similar to McVitie's, and only in stored procedures or scripts that are pretty long. I will break down certain functional portions like this:

BEGIN /** delete queries **/

DELETE FROM blah_blah

END /** delete queries **/

BEGIN /** update queries **/

UPDATE sometable SET something = 1

END /** update queries **/

This method shows up fairly nice in management studio and is really helpful in reviewing code. The collapsed piece looks sort of like:

BEGIN /** delete queries **/ ... /** delete queries **/

I actually prefer it this way because I know that my BEGIN matches with the END this way.

Prevent onmouseout when hovering child element of the parent absolute div WITHOUT jQuery

instead of onmouseout use onmouseleave.

You haven't showed to us your specific code so I cannot show you on your specific example how to do it.

But it is very simple: just replace onmouseout with onmouseleave.

That's all :) So, simple :)

If not sure how to do it, see explanation on:

https://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_onmousemove_leave_out

Peace of cake :) Enjoy it :)

Defining custom attrs

Qberticus's answer is good, but one useful detail is missing. If you are implementing these in a library replace:

xmlns:whatever="http://schemas.android.com/apk/res/org.example.mypackage"

with:

xmlns:whatever="http://schemas.android.com/apk/res-auto"

Otherwise the application that uses the library will have runtime errors.

How to get the full path of running process?

What you can do is use WMI to get the paths. This will allow you to get the path regardless it's a 32-bit or 64-bit application. Here's an example demonstrating how you can get it:

// include the namespace
using System.Management;

var wmiQueryString = "SELECT ProcessId, ExecutablePath, CommandLine FROM Win32_Process";
using (var searcher = new ManagementObjectSearcher(wmiQueryString))
using (var results = searcher.Get())
{
    var query = from p in Process.GetProcesses()
                join mo in results.Cast<ManagementObject>()
                on p.Id equals (int)(uint)mo["ProcessId"]
                select new
                {
                    Process = p,
                    Path = (string)mo["ExecutablePath"],
                    CommandLine = (string)mo["CommandLine"],
                };
    foreach (var item in query)
    {
        // Do what you want with the Process, Path, and CommandLine
    }
}

Note that you'll have to reference the System.Management.dll assembly and use the System.Management namespace.

For more info on what other information you can grab out of these processes such as the command line used to start the program (CommandLine), see the Win32_Process class and WMI .NET for for more information.

Select objects based on value of variable in object using jq

Adapted from this post on Processing JSON with jq, you can use the select(bool) like this:

$ jq '.[] | select(.location=="Stockholm")' json
{
  "location": "Stockholm",
  "name": "Walt"
}
{
  "location": "Stockholm",
  "name": "Donald"
}

Which programming languages can be used to develop in Android?

I made good experiences with Scala.

I use the simple build tool (sbt: http://code.google.com/p/simple-build-tool/) with the Android-Plugin (http://github.com/jberkel/android-plugin)

Could not install packages due to an EnvironmentError: [Errno 13]

try this command line below for MacOS to check user's permission.

$ sudo python -m pip install --user --upgrade pip

sorting and paging with gridview asp.net

Save your sorting order in a ViewState.

private const string ASCENDING = " ASC";
private const string DESCENDING = " DESC";

public SortDirection GridViewSortDirection
{
    get
    {
        if (ViewState["sortDirection"] == null)
            ViewState["sortDirection"] = SortDirection.Ascending;

        return (SortDirection) ViewState["sortDirection"];                
    }
    set { ViewState["sortDirection"] = value; } 
}

protected void GridView_Sorting(object sender, GridViewSortEventArgs e)
{
    string sortExpression = e.SortExpression;

    if (GridViewSortDirection == SortDirection.Ascending)
    {
        GridViewSortDirection = SortDirection.Descending;
        SortGridView(sortExpression, DESCENDING);
    }
    else
    {
        GridViewSortDirection = SortDirection.Ascending;
        SortGridView(sortExpression, ASCENDING); 
    }   

}

private void SortGridView(string sortExpression,string direction)
{
    //  You can cache the DataTable for improving performance
    DataTable dt = GetData().Tables[0]; 

    DataView dv = new DataView(dt); 
    dv.Sort = sortExpression + direction;         

    GridView1.DataSource = dv;
    GridView1.DataBind();         
}

Why you don't want to use existing sorting functionality? You can always customize it.

Sorting Data in a GridView Web Server Control at MSDN

Here is an example with customization:

http://www.netomatix.com/development/GridViewSorting.aspx

Use jquery to set value of div tag

When using the .html() method, a htmlString must be the parameter. (source) Put your string inside a HTML tag and it should work or use .text() as suggested by farzad.

Example:

<div class="demo-container">
    <div class="demo-box">Demonstration Box</div>
</div>

<script type="text/javascript">
$("div.demo-container").html( "<p>All new content. <em>You bet!</em></p>" );
</script>

Equivalent of LIMIT for DB2

Try this

SELECT * FROM
    (
        SELECT T.*, ROW_NUMBER() OVER() R FROM TABLE T
    )
    WHERE R BETWEEN 10000 AND 20000

How to remove and clear all localStorage data

Using .one ensures this is done only once and not repeatedly.

$(window).one("focus", function() {
    localStorage.clear();
});

It is okay to put several document.ready event listeners (if you need other events to execute multiple times) as long as you do not overdo it, for the sake of readability.

.one is especially useful when you want local storage to be cleared only once the first time a web page is opened or when a mobile application is installed the first time.

   // Fired once when document is ready
   $(document).one('ready', function () {
       localStorage.clear();
   });

height style property doesn't work in div elements

This worked for me:

min-height: 14px;
height: 14px;

How to create a new text file using Python

Looks like you forgot the mode parameter when calling open, try w:

file = open("copy.txt", "w") 
file.write("Your text goes here") 
file.close() 

The default value is r and will fail if the file does not exist

'r' open for reading (default)
'w' open for writing, truncating the file first

Other interesting options are

'x' open for exclusive creation, failing if the file already exists
'a' open for writing, appending to the end of the file if it exists

See Doc for Python2.7 or Python3.6

-- EDIT --

As stated by chepner in the comment below, it is better practice to do it with a withstatement (it guarantees that the file will be closed)

with open("copy.txt", "w") as file:
    file.write("Your text goes here")

C# - How to convert string to char?

Your question is a bit unclear, but I think you want (requires using System.Linq;):

var result = yourArrayOfStrings.SelectMany(s => s).ToArray();

Another solution is:

var result = string.Concat(yourArrayOfStrings).ToCharArray();

Compiling/Executing a C# Source File in Command Prompt

Another way to compile C# programs (without using Visual Studio or without having it installed) is to create a user variable in environment variables, namely "PATH".

Copy the following path in this variable:

"C:\Windows\Microsoft.NET\Framework\v4.0.30319"

or depending upon which .NET your PC have.

So you don't have to mention the whole path every time you compile a code. Simply use

"C:\Users\UserName\Desktop>csc [options] filename.cs"

or wherever the path of your code is.

Now you are good to go.

How to return a PNG image from Jersey REST service method to the browser

in regard of answer from @Perception, its true to be very memory-consuming when working with byte arrays, but you could also simply write back into the outputstream

@Path("/picture")
public class ProfilePicture {
  @GET
  @Path("/thumbnail")
  @Produces("image/png")
  public StreamingOutput getThumbNail() {
    return new StreamingOutput() {
      @Override
      public void write(OutputStream os) throws IOException, WebApplicationException {
        //... read your stream and write into os
      }
    };
  }
}

Remove a symlink to a directory

# this works:
rm foo
# versus this, which doesn't:
rm foo/

Basically, you need to tell it to delete a file, not delete a directory. I believe the difference between rm and rmdir exists because of differences in the way the C library treats each.

At any rate, the first should work, while the second should complain about foo being a directory.

If it doesn't work as above, then check your permissions. You need write permission to the containing directory to remove files.

How to change default timezone for Active Record in Rails?

for Chinese user, just add two lines below to you config/application.rb :

config.active_record.default_timezone = :local
config.time_zone = 'Beijing'

Https to http redirect using htaccess

You can use the following rule to redirect from https to http :

 RewriteEngine On


RewriteCond %{HTTPS} ^on$
RewriteRule ^(.*)$ http://example.com/$1 [NC,L,R]

Explanation :

RewriteCond %{HTTPS} ^on$

Checks if the HTTPS is on (Request is made using https)

Then

RewriteRule ^(.*)$ http://example.com/$1 [NC,L,R]

Redirect any request (https://example.com/foo) to http://example.com/foo .

  • $1 is part of the regex in RewriteRule pattern, it contains whatever value was captured in (.+) , in this case ,it captures the full request_uri everything after the domain name.

  • [NC,L,R] are the flags, NC makes the uri case senstive, you can use both uppercase or lowercase letters in the request.

L flag tells the server to stop proccessing other rules if the currunt rule has matched, it is important to use the L flag to avoid rule confliction when you have more then on rules in a block.

R flag is used to make an external redirection.

Location for session files in Apache/PHP

The default session.save_path is set to "" which will evaluate to your system's temp directory. See this comment at https://bugs.php.net/bug.php?id=26757 stating:

The new default for save_path in upcoming releaess (sic) will be the empty string, which causes the temporary directory to be probed.

You can use sys_get_temp_dir to return the directory path used for temporary files

To find the current session save path, you can use

Refer to this answer to find out what the temp path is when this function returns an empty string.

How to enable and use HTTP PUT and DELETE with Apache2 and PHP?

AllowOverride AuthConfig

try this. Authentication may be the problem. I was working with a CGI script written in C++, and faced some authentication issues when passed DELETE. The above solution helped me. It may help in your case too.


Also even if you don't get the solution for your problem of PUT and DELETE, do not stop working rather use "CORS". It is a google chrome app, which will help you bypass the problem, but remember it is a temporary solution, so that your work or experiments doesn't remain freeze for long. Obviously, you cannot ask your client to have "CORS" enabled to run your solution, as it may compromise systems security.

PHP unable to load php_curl.dll extension

Usually this is an OpenSSL version mismatch error, between Apache and PHP. In case Apache loads PHP as a DSO module, its own OpenSSL versions (dlls and libs) will be used. So, in case the PHP extension requires a newer version, it may not find the appropriate interface inside the Apache-loaded DLLS and it will fail to work.

Since you need the PHP extension to load, you need the relevant DLL files to be at least the version of what the PHP module asks for. Supposing that you 're using lastest builds for both Apache and PHP and both having been built with the same MVC version, you can copy the following files:

  • libcrypto-1_1.dll
  • libcrypto-1_1-x64.dll
  • libcurl.dll
  • libsasl.dll
  • libssh2.dll
  • libssl-1_1.dll
  • libssl-1_1-x64.dll
  • nghttp2.dll
  • libeay32.dll (if existing in your PHP distribution)
  • ssleay32.dll (if existing in your PHP distribution)

from the PHP root folder to the Apache2/bin folder, in case you 're confident that the PHP build is newer than the Apache build.

In the opposite case, you can copy the same files from the Apache BIN to the PHP root.

In any case, backup the contents of the APache and PHP folders beforehand.

Adding the PHP path as an enviromental variable will give priority to this path for loading the relevant DLLs and may solve the problem. However, you lose in server portability. Additionally, if you have also added the Apache PATH as a variable and the OpenSSL versions are way different (up to loading different linked DLL files), a lot of shit may happen.

How to remove class from all elements jquery

You could try this:

 $(".edgetoedge").children().removeClass("highlight");

how to save DOMPDF generated content to file?

I have just used dompdf and the code was a little different but it worked.

Here it is:

require_once("./pdf/dompdf_config.inc.php");
$files = glob("./pdf/include/*.php");
foreach($files as $file) include_once($file);

$html =
      '<html><body>'.
      '<p>Put your html here, or generate it with your favourite '.
      'templating system.</p>'.
      '</body></html>';

    $dompdf = new DOMPDF();
    $dompdf->load_html($html);
    $dompdf->render();
    $output = $dompdf->output();
    file_put_contents('Brochure.pdf', $output);

Only difference here is that all of the files in the include directory are included.

Other than that my only suggestion would be to specify a full directory path for writing the file rather than just the filename.

Changing the default icon in a Windows Forms application

select Main form -> properties -> Windows style -> icon -> browse your ico

this.Icon = ((System.Drawing.Icon)(resources.GetObject("$this.Icon")));

How to set commands output as a variable in a batch file

I most cases, creating a temporary file named after your variable name might be acceptable. (as you are probably using meaningful variables name...)

Here, my variable name is SSH_PAGEANT_AUTH_SOCK

dir /w "\\.\pipe\\"|find "pageant" > %temp%\SSH_PAGEANT_AUTH_SOCK && set /P SSH_PAGEANT_AUTH_SOCK=<%temp%\SSH_PAGEANT_AUTH_SOCK

python multithreading wait till all threads finished

Maybe, something like

for t in threading.enumerate():
    if t.daemon:
        t.join()

Is there a CSS selector for the first direct child only?

The CSS selector for the direct first-child in your case is:

.section > :first-child

The direct selector is > and the first child selector is :first-child

No need for an asterisk before the : as others suggest. You could speed up the DOM searching by modifying this solution by prepending the tag:

div.section > :first-child

Adding text to a cell in Excel using VBA

You need to use Range and Value functions.
Range would be the cell where you want the text you want
Value would be the text that you want in that Cell

Range("A1").Value="whatever text"

Adjust plot title (main) position

We can use title() function with negative line value to bring down the title.

See this example:

plot(1, 1)
title("Title", line = -2)

enter image description here

Android: how to hide ActionBar on certain activities

1.Go to your manifest.xml file.

2.Find the activity tag for which you want to hide your ActionBar and then add ,

android:theme="@style/Theme.AppCompat.NoActionBar"

           <activity
            android:name=".MainActivity"
            android:theme="@style/Theme.AppCompat.NoActionBar"
            >

Count number of 1's in binary representation

The best way in javascript to do so is

function getBinaryValue(num){
 return num.toString(2);
}

function checkOnces(binaryValue){
    return binaryValue.toString().replace(/0/g, "").length;
}

where binaryValue is the binary String eg: 1100

Fling gesture detection on grid layout

There's some proposition over the web (and this page) to use ViewConfiguration.getScaledTouchSlop() to have a device-scaled value for SWIPE_MIN_DISTANCE.

getScaledTouchSlop() is intended for the "scrolling threshold" distance, not swipe. The scrolling threshold distance has to be smaller than a "swing between page" threshold distance. For example, this function returns 12 pixels on my Samsung GS2, and the examples quoted in this page are around 100 pixels.

With API Level 8 (Android 2.2, Froyo), you've got getScaledPagingTouchSlop(), intended for page swipe. On my device, it returns 24 (pixels). So if you're on API Level < 8, I think "2 * getScaledTouchSlop()" should be the "standard" swipe threshold. But users of my application with small screens told me that it was too few... As on my application, you can scroll vertically, and change page horizontally. With the proposed value, they sometimes change page instead of scrolling.

Error Domain=NSURLErrorDomain Code=-1005 "The network connection was lost."

Got the issue for months, and finally discovered that when we disable DNSSEC on our api domain, everything was ok :simple_smile:

Identifying Exception Type in a handler Catch Block

try
{
    // Some code
}
catch (Web2PDFException ex)
{
    // It's your special exception
}
catch (Exception ex)
{
    // Any other exception here
}

How do I keep Python print from adding newlines or spaces?

In Python 3, use

print('h', end='')

to suppress the endline terminator, and

print('a', 'b', 'c', sep='')

to suppress the whitespace separator between items. See the documentation for print

How to use apply a custom drawable to RadioButton?

Give your radiobutton a custom style:

<style name="MyRadioButtonStyle" parent="@android:style/Widget.CompoundButton.RadioButton">
    <item name="android:button">@drawable/custom_btn_radio</item>
</style>

custom_btn_radio.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_checked="true" android:state_window_focused="false"
          android:drawable="@drawable/btn_radio_on" />
    <item android:state_checked="false" android:state_window_focused="false"
          android:drawable="@drawable/btn_radio_off" />

    <item android:state_checked="true" android:state_pressed="true"
          android:drawable="@drawable/btn_radio_on_pressed" />
    <item android:state_checked="false" android:state_pressed="true"
          android:drawable="@drawable/btn_radio_off_pressed" />

    <item android:state_checked="true" android:state_focused="true"
          android:drawable="@drawable/btn_radio_on_selected" />
    <item android:state_checked="false" android:state_focused="true"
          android:drawable="@drawable/btn_radio_off_selected" />

    <item android:state_checked="false" android:drawable="@drawable/btn_radio_off" />
    <item android:state_checked="true" android:drawable="@drawable/btn_radio_on" />
</selector>

Replace the drawables with your own.

System.Net.WebException: The remote name could not be resolved:

I had a similar issue when trying to access a service (old ASMX service). The call would work when accessing via an IP however when calling with an alias I would get the remote name could not be resolved.

Added the following to the config and it resolved the issue:

<system.net>
    <defaultProxy enabled="true">
    </defaultProxy>
</system.net>

Excel date to Unix timestamp

You're apparently off by one day, exactly 86400 seconds. Use the number 2209161600 Not the number 2209075200 If you Google the two numbers, you'll find support for the above. I tried your formula but was always coming up 1 day different from my server. It's not obvious from the unix timestamp unless you think in unix instead of human time ;-) but if you double check then you'll see this might be correct.

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

This isn’t a solution in the sense that it doesn’t resolve the conditions which cause the message to appear in the logs, but the message can be suppressed by appending the following to conf/logging.properties:

org.apache.catalina.webresources.Cache.level = SEVERE

This filters out the “Unable to add the resource” logs, which are at level WARNING.

In my view a WARNING is not necessarily an error that needs to be addressed, but rather can be ignored if desired.

How to set up a Web API controller for multipart/form-data

I normally use the HttpPostedFileBase parameter only in Mvc Controllers. When dealing with ApiControllers try checking the HttpContext.Current.Request.Files property for incoming files instead:

[HttpPost]
public string UploadFile()
{
    var file = HttpContext.Current.Request.Files.Count > 0 ?
        HttpContext.Current.Request.Files[0] : null;

    if (file != null && file.ContentLength > 0)
    {
        var fileName = Path.GetFileName(file.FileName);

        var path = Path.Combine(
            HttpContext.Current.Server.MapPath("~/uploads"),
            fileName
        );

        file.SaveAs(path);
    }

    return file != null ? "/uploads/" + file.FileName : null;
}

Laravel 5.2 redirect back with success message

You can use laravel MessageBag to add our own messages to existing messages.

To use MessageBag you need to use:

use Illuminate\Support\MessageBag;

In the controller:

MessageBag $message_bag

$message_bag->add('message', trans('auth.confirmation-success'));

return redirect('login')->withSuccess($message_bag);

Hope it will help some one.

  • Adi

VBA Public Array : how to?

You are using the wrong type. The Array(...) function returns a Variant, not a String.

Thus, in the Declaration section of your module (it does not need to be a different module!), you define

Public colHeader As Variant

and somewhere at the beginning of your program code (for example, in the Workbook_Open event) you initialize it with

colHeader = Array("A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L")

Another (simple) alternative would be to create a function that returns the array, e.g. something like

Public Function GetHeaders() As Variant
    GetHeaders = Array("A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L")
End Function

This has the advantage that you do not need to initialize the global variable and the drawback that the array is created again on every function call.

Radio button checked event handling

Update in 2017: Hey. This is a terrible answer. Don't use it. Back in the old days this type of jQuery use was common. And it probably worked back then. Just read it, realize it's terrible, then move on (or downvote or, whatever) to one of the other answers that are better for today's jQuery.


$("input[type=radio]").change(function(){
    alert( $("input[type=radio][name="+ this.name + "]").val() );
});

How to get directory size in PHP

if you are hosted on Linux:

passthru('du -h -s ' . $DIRECTORY_PATH)

It's better than foreach

Creating files in C++

#include <iostream>
#include <fstream>

int main() {
  std::ofstream o("Hello.txt");

  o << "Hello, World\n" << std::endl;

  return 0;
}

Looking for a 'cmake clean' command to clear up CMake output

In the case where you pass -D parameters into CMake when generating the build files and don't want to delete the entire build/ directory:

Simply delete the CMakeFiles/ directory inside your build directory.

rm -rf CMakeFiles/
cmake --build .

This causes CMake to rerun, and build system files are regenerated. Your build will also start from scratch.

In what cases will HTTP_REFERER be empty

BalusC's list is solid. One additional way this field frequently appears empty is when the user is behind a proxy server. This is similar to being behind a firewall but is slightly different so I wanted to mention it for the sake of completeness.

In R, how to find the standard error of the mean?

You can use the function stat.desc from pastec package.

library(pastec)
stat.desc(x, BASIC =TRUE, NORMAL =TRUE)

you can find more about it from here: https://www.rdocumentation.org/packages/pastecs/versions/1.3.21/topics/stat.desc

Reset Excel to default borders

I had this issue, grid lines appeared to be missing on some cells.

Took me awhile to figure out that the color of those cells were white. I clicked format cell, pattern and then selected "no color" (instead of white) The the grid lines were visible again.

I hope this helps others as it took me a while to figure out why.

Sort ArrayList of custom Objects by property

I prefer this process:

public class SortUtil
{    
    public static <T> List<T> sort(List<T> list, String sortByProperty)
    {
            Collections.sort(list, new BeanComparator(sortByProperty));
            return list;
    }
}

List<T> sortedList = SortUtil<T>.sort(unsortedList, "startDate");

If you list of objects has a property called startDate, you call use this over and over. You can even chain them startDate.time.

This requires your object to be Comparable which means you need a compareTo, equals, and hashCode implementation.

Yes, it could be faster... But now you don't have to make a new Comparator for each type of sort. If you can save on dev time and give up on runtime, you might go with this one.

wait() or sleep() function in jquery?

I found a function called sleep function on the internet and don't know who made it. Here it is.

function sleep(milliseconds) {
  var start = new Date().getTime();
  for (var i = 0; i < 1e7; i++) {
    if ((new Date().getTime() - start) > milliseconds){
      break;
    }
  }
}

sleep(2000);

Remove numbers from string sql server

This one works for me

CREATE Function [dbo].[RemoveNumericCharacters](@Temp VarChar(1000))
Returns VarChar(1000)
AS
Begin

    Declare @NumRange as varchar(50) = '%[0-9]%'
    While PatIndex(@NumRange, @Temp) > 0
        Set @Temp = Stuff(@Temp, PatIndex(@NumRange, @Temp), 1, '')

    Return @Temp
End

and you can use it like so

SELECT dbo.[RemoveNumericCharacters](Name) FROM TARGET_TABLE

Maintaining href "open in new tab" with an onClick handler in React

You have two options here, you can make it open in a new window/tab with JS:

<td onClick={()=> window.open("someLink", "_blank")}>text</td>

But a better option is to use a regular link but style it as a table cell:

<a style={{display: "table-cell"}} href="someLink" target="_blank">text</a>

How do I break out of nested loops in Java?

If you don't like breaks and gotos, you can use a "traditional" for loop instead the for-in, with an extra abort condition:

int a, b;
bool abort = false;
for (a = 0; a < 10 && !abort; a++) {
    for (b = 0; b < 10 && !abort; b++) {
        if (condition) {
            doSomeThing();
            abort = true;
        }
    }
}

Removing path and extension from filename in PowerShell

Expanding on René Nyffenegger's answer, for those who do not have access to PowerShell version 6.x, we use Split Path, which doesn't test for file existence:

Split-Path "C:\Folder\SubFolder\myfile.txt" -Leaf

This returns "myfile.txt". If we know that the file name doesn't have periods in it, we can split the string and take the first part:

(Split-Path "C:\Folder\SubFolder\myfile.txt" -Leaf).Split('.') | Select -First 1

or

(Split-Path "C:\Folder\SubFolder\myfile.txt" -Leaf).Split('.')[0]

This returns "myfile". If the file name might include periods, to be safe, we could use the following:

$FileName = Split-Path "C:\Folder\SubFolder\myfile.txt.config.txt" -Leaf
$Extension = $FileName.Split('.') | Select -Last 1
$FileNameWoExt = $FileName.Substring(0, $FileName.Length - $Extension.Length - 1)

This returns "myfile.txt.config". Here I prefer to use Substring() instead of Replace() because the extension preceded by a period could also be part of the name, as in my example. By using Substring we return the filename without the extension as requested.

How to reject in async/await syntax?

Your best bet is to throw an Error wrapping the value, which results in a rejected promise with an Error wrapping the value:

} catch (error) {
    throw new Error(400);
}

You can also just throw the value, but then there's no stack trace information:

} catch (error) {
    throw 400;
}

Alternately, return a rejected promise with an Error wrapping the value, but it's not idiomatic:

} catch (error) {
    return Promise.reject(new Error(400));
}

(Or just return Promise.reject(400);, but again, then there's no context information.)

In your case, as you're using TypeScript and foo's return value is Promise<A>, you'd use this:

return Promise.reject<A>(400 /*or Error*/ );

In an async/await situation, that last is probably a bit of a semantic mis-match, but it does work.

If you throw an Error, that plays well with anything consuming your foo's result with await syntax:

try {
    await foo();
} catch (error) {
    // Here, `error` would be an `Error` (with stack trace, etc.).
    // Whereas if you used `throw 400`, it would just be `400`.
}

how to convert current date to YYYY-MM-DD format with angular 2

Here is a very nice and compact way to do this, you can also change this function as your case needs:

result: 03.11.2017

//get date now function
    getNowDate() {
    //return string
    var returnDate = "";
    //get datetime now
    var today = new Date();
    //split
    var dd = today.getDate();
    var mm = today.getMonth() + 1; //because January is 0! 
    var yyyy = today.getFullYear();
    //Interpolation date
    if (dd < 10) {
        returnDate += `0${dd}.`;
    } else {
        returnDate += `${dd}.`;
    }

    if (mm < 10) {
        returnDate += `0${mm}.`;
    } else {
        returnDate += `${mm}.`;
    }
    returnDate += yyyy;
    return returnDate;
}

java.lang.UnsatisfiedLinkError: dalvik.system.PathClassLoader

If you use module with c++ code and have the same issue you could try

Build -> Refresh Linked C++ Projects

Also, you should open some file from this module and do

Build -> Make module "YourNativeLibModuleName"

Unix ls command: show full path when using options

simply use find tool.

find absolute_path

displays full paths on my Linux machine, while

find relative_path

will not.

Manage toolbar's navigation and back button from fragment in android

You can use Toolbar inside the fragment and it is easy to handle. First add Toolbar to layout of the fragment

<android.support.v7.widget.Toolbar
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/toolbar"
    android:layout_height="wrap_content"
    android:layout_width="match_parent"
    android:fitsSystemWindows="true"
    android:minHeight="?attr/actionBarSize"
    app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
    android:background="?attr/colorPrimaryDark">
</android.support.v7.widget.Toolbar>

Inside the onCreateView Method in the fragment you can handle the toolbar like this.

 Toolbar toolbar = (Toolbar) view.findViewById(R.id.toolbar);
 toolbar.setTitle("Title");
 toolbar.setNavigationIcon(R.drawable.ic_arrow_back);

IT will set the toolbar,title and the back arrow navigation to toolbar.You can set any icon to setNavigationIcon method.

If you need to trigger any event when click toolbar navigation icon you can use this.

 toolbar.setNavigationOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
           //handle any click event
    });

If your activity have navigation drawer you may need to open that when click the navigation back button. you can open that drawer like this.

 toolbar.setNavigationOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            DrawerLayout drawer = (DrawerLayout) getActivity().findViewById(R.id.drawer_layout);
            drawer.openDrawer(Gravity.START);
        }
    });

Full code is here

 public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    //inflate the layout to the fragement
    view = inflater.inflate(R.layout.layout_user,container,false);

    //initialize the toolbar
    Toolbar toolbar = (Toolbar) view.findViewById(R.id.toolbar);
    toolbar.setTitle("Title");
    toolbar.setNavigationIcon(R.drawable.ic_arrow_back);
    toolbar.setNavigationOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //open navigation drawer when click navigation back button
            DrawerLayout drawer = (DrawerLayout) getActivity().findViewById(R.id.drawer_layout);
            drawer.openDrawer(Gravity.START);
        }
    });
    return view;
}

'any' vs 'Object'

Bit old, but doesn't hurt to add some notes.

When you write something like this

let a: any;
let b: Object;
let c: {};
  • a has no interface, it can be anything, the compiler knows nothing about its members so no type checking is performed when accessing/assigning both to it and its members. Basically, you're telling the compiler to "back off, I know what I'm doing, so just trust me";
  • b has the Object interface, so ONLY the members defined in that interface are available for b. It's still JavaScript, so everything extends Object;
  • c extends Object, like anything else in TypeScript, but adds no members. Since type compatibility in TypeScript is based on structural subtyping, not nominal subtyping, c ends up being the same as b because they have the same interface: the Object interface.

And that's why

a.doSomething(); // Ok: the compiler trusts you on that
b.doSomething(); // Error: Object has no doSomething member
c.doSomething(); // Error: c neither has doSomething nor inherits it from Object

and why

a.toString(); // Ok: whatever, dude, have it your way
b.toString(); // Ok: toString is defined in Object
c.toString(); // Ok: c inherits toString from Object

So Object and {} are equivalents in TypeScript.

If you declare functions like these

function fa(param: any): void {}
function fb(param: Object): void {}

with the intention of accepting anything for param (maybe you're going to check types at run-time to decide what to do with it), remember that

  • inside fa, the compiler will let you do whatever you want with param;
  • inside fb, the compiler will only let you reference Object's members.

It is worth noting, though, that if param is supposed to accept multiple known types, a better approach is to declare it using union types, as in

function fc(param: string|number): void {}

Obviously, OO inheritance rules still apply, so if you want to accept instances of derived classes and treat them based on their base type, as in

interface IPerson {
    gender: string;
}

class Person implements IPerson {
    gender: string;
}

class Teacher extends Person {}

function func(person: IPerson): void {
    console.log(person.gender);
}

func(new Person());     // Ok
func(new Teacher());    // Ok
func({gender: 'male'}); // Ok
func({name: 'male'});   // Error: no gender..

the base type is the way to do it, not any. But that's OO, out of scope, I just wanted to clarify that any should only be used when you don't know whats coming, and for anything else you should annotate the correct type.

UPDATE:

Typescript 2.2 added an object type, which specifies that a value is a non-primitive: (i.e. not a number, string, boolean, symbol, undefined, or null).

Consider functions defined as:

function b(x: Object) {}
function c(x: {}) {}
function d(x: object) {}

x will have the same available properties within all of these functions, but it's a type error to call d with a primitive:

b("foo"); //Okay
c("foo"); //Okay
d("foo"); //Error: "foo" is a primitive

Algorithm to calculate the number of divisors of a given number

Try something along these lines:

int divisors(int myNum) {
    int limit = myNum;
    int divisorCount = 0;
    if (x == 1) 
        return 1;
    for (int i = 1; i < limit; ++i) {
        if (myNum % i == 0) {
            limit = myNum / i;
            if (limit != i)
                divisorCount++;
            divisorCount++;
        }
    }
    return divisorCount;
}

Convert wchar_t to char

assert is for ensuring that something is true in a debug mode, without it having any effect in a release build. Better to use an if statement and have an alternate plan for characters that are outside the range, unless the only way to get characters outside the range is through a program bug.

Also, depending on your character encoding, you might find a difference between the Unicode characters 0x80 through 0xff and their char version.

How to extract extension from filename string in Javascript?

I personally prefer to split the string by . and just return the last array element :)

var fileExt = filename.split('.').pop();

If there is no . in filename you get the entire string back.

Examples:

'some_value'                                   => 'some_value'
'.htaccess'                                    => 'htaccess'
'../images/something.cool.jpg'                 => 'jpg'
'http://www.w3schools.com/jsref/jsref_pop.asp' => 'asp'
'http://stackoverflow.com/questions/680929'    => 'com/questions/680929'

Easiest way to use SVG in Android?

You can use Coil library to load svg. Just add these lines in build.gradle

// ... Coil (https://github.com/coil-kt/coil)
implementation("io.coil-kt:coil:0.12.0")
implementation("io.coil-kt:coil-svg:0.12.0")

Then Add an extension function

fun AppCompatImageView.loadSvg(url: String) {
    val imageLoader = ImageLoader.Builder(this.context)
        .componentRegistry { add(SvgDecoder([email protected])) }
        .build()

    val request = ImageRequest.Builder(this.context)
        .crossfade(true)
        .crossfade(500)
        .data(url)
        .target(this)
        .build()

    imageLoader.enqueue(request)
}

Then call this method in your activity or fragment

your_image_view.loadSvg("your_file_name.svg")

ImportError: No module named 'Queue'

I just copy the file name Queue.py in the */lib/python2.7/ to queue.py and that solved my problem.

Declaring a custom android UI element using XML

You can include any layout file in other layout file as-

             <RelativeLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="10dp"
                android:layout_marginRight="30dp" >

                <include
                    android:id="@+id/frnd_img_file"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    layout="@layout/include_imagefile"/>

                <include
                    android:id="@+id/frnd_video_file"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    layout="@layout/include_video_lay" />

                <ImageView
                    android:id="@+id/downloadbtn"
                    android:layout_width="30dp"
                    android:layout_height="30dp"
                    android:layout_centerInParent="true"
                    android:src="@drawable/plus"/>
            </RelativeLayout>

here the layout files in include tag are other .xml layout files in the same res folder.

ASP.NET - How to write some html in the page? With Response.Write?

If you really don't want to use any server controls, you should put the Response.Write in the place you want the string to be written:

<body>
<% Response.Write(stringVariable); %>
</body>

A shorthand for this syntax is:

<body>
<%= stringVariable %>
</body>

How to clear the JTextField by clicking JButton

Looking for EventHandling, ActionListener?

or code?

JButton b = new JButton("Clear");
b.addActionListener(new ActionListener(){
    public void actionPerformed(ActionEvent e){
        textfield.setText("");
        //textfield.setText(null); //or use this
    }
});

Also See
How to Use Buttons

RichTextBox (WPF) does not have string property "Text"

RichTextBox rtf = new RichTextBox();
System.IO.MemoryStream stream = new System.IO.MemoryStream(ASCIIEncoding.Default.GetBytes(yourText));

rtf.Selection.Load(stream, DataFormats.Rtf);

OR

rtf.Selection.Text = yourText;

How to see full query from SHOW PROCESSLIST

SHOW FULL PROCESSLIST

If you don't use FULL, "only the first 100 characters of each statement are shown in the Info field".

When using phpMyAdmin, you should also click on the "Full texts" option ("? T ?" on top left corner of a results table) to see untruncated results.

How to loop through a directory recursively to delete files with certain extensions

This method handles spaces well.

files="$(find -L "$dir" -type f)"
echo "Count: $(echo -n "$files" | wc -l)"
echo "$files" | while read file; do
  echo "$file"
done

Edit, fixes off-by-one

function count() {
    files="$(find -L "$1" -type f)";
    if [[ "$files" == "" ]]; then
        echo "No files";
        return 0;
    fi
    file_count=$(echo "$files" | wc -l)
    echo "Count: $file_count"
    echo "$files" | while read file; do
        echo "$file"
    done
}

How to change the display name for LabelFor in razor in mvc3?

@Html.LabelFor(model => model.SomekingStatus, "foo bar")

How to list the properties of a JavaScript object?

Mozilla has full implementation details on how to do it in a browser where it isn't supported, if that helps:

if (!Object.keys) {
  Object.keys = (function () {
    var hasOwnProperty = Object.prototype.hasOwnProperty,
        hasDontEnumBug = !({toString: null}).propertyIsEnumerable('toString'),
        dontEnums = [
          'toString',
          'toLocaleString',
          'valueOf',
          'hasOwnProperty',
          'isPrototypeOf',
          'propertyIsEnumerable',
          'constructor'
        ],
        dontEnumsLength = dontEnums.length;

    return function (obj) {
      if (typeof obj !== 'object' && typeof obj !== 'function' || obj === null) throw new TypeError('Object.keys called on non-object');

      var result = [];

      for (var prop in obj) {
        if (hasOwnProperty.call(obj, prop)) result.push(prop);
      }

      if (hasDontEnumBug) {
        for (var i=0; i < dontEnumsLength; i++) {
          if (hasOwnProperty.call(obj, dontEnums[i])) result.push(dontEnums[i]);
        }
      }
      return result;
    };
  })();
}

You could include it however you'd like, but possibly in some kind of extensions.js file at the top of your script stack.

Relative URLs in WordPress

<?php wp_make_link_relative( $link ) ?>

Convert full URL paths to relative paths.

Removes the http or https protocols and the domain. Keeps the path '/' at the beginning, so it isn't a true relative link, but from the web root base.

Reference: Wordpress Codex

Connection to SQL Server Works Sometimes

I had the same problem, manage to solve it by opening/enabling the port 1433 and tcp/ip in SQL Server Configuration Manager and then Restarted the Server

enter image description here

Best programming based games

My favourite was PCRobots back in the 90's - you could write your bot in pretty much any language that could compile a DOS executable. Still runs quite nicely in DOSBox :)

Convert list of ints to one number?

Using a generator expression:

def magic(numbers):
    digits = ''.join(str(n) for n in numbers)
    return int(digits)

What is tail recursion?

The recursive function is a function which calls by itself

It allows programmers to write efficient programs using a minimal amount of code.

The downside is that they can cause infinite loops and other unexpected results if not written properly.

I will explain both Simple Recursive function and Tail Recursive function

In order to write a Simple recursive function

  1. The first point to consider is when should you decide on coming out of the loop which is the if loop
  2. The second is what process to do if we are our own function

From the given example:

public static int fact(int n){
  if(n <=1)
     return 1;
  else 
     return n * fact(n-1);
}

From the above example

if(n <=1)
     return 1;

Is the deciding factor when to exit the loop

else 
     return n * fact(n-1);

Is the actual processing to be done

Let me the break the task one by one for easy understanding.

Let us see what happens internally if I run fact(4)

  1. Substituting n=4
public static int fact(4){
  if(4 <=1)
     return 1;
  else 
     return 4 * fact(4-1);
}

If loop fails so it goes to else loop so it returns 4 * fact(3)

  1. In stack memory, we have 4 * fact(3)

    Substituting n=3

public static int fact(3){
  if(3 <=1)
     return 1;
  else 
     return 3 * fact(3-1);
}

If loop fails so it goes to else loop

so it returns 3 * fact(2)

Remember we called ```4 * fact(3)``

The output for fact(3) = 3 * fact(2)

So far the stack has 4 * fact(3) = 4 * 3 * fact(2)

  1. In stack memory, we have 4 * 3 * fact(2)

    Substituting n=2

public static int fact(2){
  if(2 <=1)
     return 1;
  else 
     return 2 * fact(2-1);
}

If loop fails so it goes to else loop

so it returns 2 * fact(1)

Remember we called 4 * 3 * fact(2)

The output for fact(2) = 2 * fact(1)

So far the stack has 4 * 3 * fact(2) = 4 * 3 * 2 * fact(1)

  1. In stack memory, we have 4 * 3 * 2 * fact(1)

    Substituting n=1

public static int fact(1){
  if(1 <=1)
     return 1;
  else 
     return 1 * fact(1-1);
}

If loop is true

so it returns 1

Remember we called 4 * 3 * 2 * fact(1)

The output for fact(1) = 1

So far the stack has 4 * 3 * 2 * fact(1) = 4 * 3 * 2 * 1

Finally, the result of fact(4) = 4 * 3 * 2 * 1 = 24

enter image description here

The Tail Recursion would be

public static int fact(x, running_total=1) {
    if (x==1) {
        return running_total;
    } else {
        return fact(x-1, running_total*x);
    }
}

  1. Substituting n=4
public static int fact(4, running_total=1) {
    if (x==1) {
        return running_total;
    } else {
        return fact(4-1, running_total*4);
    }
}

If loop fails so it goes to else loop so it returns fact(3, 4)

  1. In stack memory, we have fact(3, 4)

    Substituting n=3

public static int fact(3, running_total=4) {
    if (x==1) {
        return running_total;
    } else {
        return fact(3-1, 4*3);
    }
}

If loop fails so it goes to else loop

so it returns fact(2, 12)

  1. In stack memory, we have fact(2, 12)

    Substituting n=2

public static int fact(2, running_total=12) {
    if (x==1) {
        return running_total;
    } else {
        return fact(2-1, 12*2);
    }
}

If loop fails so it goes to else loop

so it returns fact(1, 24)

  1. In stack memory, we have fact(1, 24)

    Substituting n=1

public static int fact(1, running_total=24) {
    if (x==1) {
        return running_total;
    } else {
        return fact(1-1, 24*1);
    }
}

If loop is true

so it returns running_total

The output for running_total = 24

Finally, the result of fact(4,1) = 24

enter image description here

Bold words in a string of strings.xml in Android

In Kotlin I have created an extension function for the Context. It takes a @StringRes and optionally you can provide parameters as well.

fun Context.fromHtmlWithParams(@StringRes stringRes: Int, parameter : String? = null) : Spanned {

    val stringText = if (parameter.isNullOrEmpty()) {
                    this.getString(stringRes)
                } else {
                    this.getString(stringRes, parameter)
                }

    return Html.fromHtml(stringText, Html.FROM_HTML_MODE_LEGACY)

}

Usage

tv_directors.text = context?.fromHtmlWithParams(R.string.directors, movie.Director)

How do I POST a x-www-form-urlencoded request using Fetch?

Just Use

import  qs from "qs";
 let data = {
        'profileId': this.props.screenProps[0],
        'accountId': this.props.screenProps[1],
        'accessToken': this.props.screenProps[2],
        'itemId': this.itemId
    };
    return axios.post(METHOD_WALL_GET, qs.stringify(data))

When to Redis? When to MongoDB?

Redis is an in memory data store, that can persist it's state to disk (to enable recovery after restart). However, being an in-memory data store means the size of the data store (on a single node) cannot exceed the total memory space on the system (physical RAM + swap space). In reality, it will be much less that this, as Redis is sharing that space with many other processes on the system, and if it exhausts the system memory space it will likely be killed off by the operating system.

Mongo is a disk based data store, that is most efficient when it's working set fits within physical RAM (like all software). Being a disk based data means there are no intrinsic limits on the size of a Mongo database, however configuration options, available disk space, and other concerns may mean that databases sizes over a certain limit may become impractical or inefficient.

Both Redis and Mongo can be clustered for high availability, backup and to increase the overall size of the datastore.

Elasticsearch difference between MUST and SHOULD bool query

Since this is a popular question, I would like to add that in Elasticsearch version 2 things changed a bit.

Instead of filtered query, one should use bool query in the top level.

If you don't care about the score of must parts, then put those parts into filter key. No scoring means faster search. Also, Elasticsearch will automatically figure out, whether to cache them, etc. must_not is equally valid for caching.

Reference: https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-bool-query.html

Also, mind that "gte": "now" cannot be cached, because of millisecond granularity. Use two ranges in a must clause: one with now/1h and another with now so that the first can be cached for a while and the second for precise filtering accelerated on a smaller result set.

How to convert a negative number to positive?

simply multiplying by -1 works in both ways ...

>>> -10 * -1
10
>>> 10 * -1
-10

Is there a way to delete all the data from a topic or delete the topic before every run?

All data about topics and its partitions are stored in tmp/kafka-logs/. Moreover they are stored in a format topic-partionNumber, so if you want to delete a topic newTopic, you can:

  • stop kafka
  • delete the files rm -rf /tmp/kafka-logs/newTopic-*

Export data from Chrome developer tool

Note that ≪Copy all as HAR≫ does not contain response body.

You can get response body via ≪Save as HAR with Content≫, but it breaks if you have any more than a trivial amount of logs (I tried once with only 8k requests and it doesn't work.) To solve this, you can script an output yourself using _request.contentData().

When there's too many logs, even _request.contentData() and ≪Copy response≫ would fail, hopefully they would fix this problem. Until then, inspecting any more than a trivial amount of network logs cannot be properly done with Chrome Network Inspector and its best to use another tool.

How do I find the size of a struct?

I assume you mean struct and not strict, but on a 32-bit system it'll be either 5 or 8 bytes, depending on if the compiler is padding the struct.

Convert integers to strings to create output filenames at run time

Here is my subroutine approach to this problem. it transforms an integer in the range 0 : 9999 as a character. For example, the INTEGER 123 is transformed into the character 0123. hope it helps.

P.S. - sorry for the comments; they make sense in Romanian :P

 subroutine nume_fisier (i,filename_tot)

   implicit none
   integer :: i

   integer :: integer_zeci,rest_zeci,integer_sute,rest_sute,integer_mii,rest_mii
   character(1) :: filename1,filename2,filename3,filename4
   character(4) :: filename_tot

! Subrutina ce transforma un INTEGER de la 0 la 9999 in o serie de CARACTERE cu acelasi numar

! pentru a fi folosite in numerotarea si denumirea fisierelor de rezultate.

 if(i<=9) then

  filename1=char(48+0)
  filename2=char(48+0)
  filename3=char(48+0)
  filename4=char(48+i)  

 elseif(i>=10.and.i<=99) then

  integer_zeci=int(i/10)
  rest_zeci=mod(i,10)
  filename1=char(48+0)
  filename2=char(48+0)
  filename3=char(48+integer_zeci)
  filename4=char(48+rest_zeci)

 elseif(i>=100.and.i<=999) then

  integer_sute=int(i/100)
  rest_sute=mod(i,100)
  integer_zeci=int(rest_sute/10)
  rest_zeci=mod(rest_sute,10)
  filename1=char(48+0)
  filename2=char(48+integer_sute)
  filename3=char(48+integer_zeci)
  filename4=char(48+rest_zeci)

 elseif(i>=1000.and.i<=9999) then

  integer_mii=int(i/1000)
  rest_mii=mod(i,1000)
  integer_sute=int(rest_mii/100)
  rest_sute=mod(rest_mii,100)
  integer_zeci=int(rest_sute/10)
  rest_zeci=mod(rest_sute,10)
  filename1=char(48+integer_mii)
  filename2=char(48+integer_sute)
  filename3=char(48+integer_zeci) 
  filename4=char(48+rest_zeci)

 endif

 filename_tot=''//filename1//''//filename2//''//filename3//''//filename4//''
 return
 end subroutine nume_fisier

DevTools failed to load SourceMap: Could not load content for chrome-extension

include.prepload.js file will have a line something like below. probably as the last line.

//# sourceMappingURL=include.prepload.js.map

Delete it and the error will go away.

Writing MemoryStream to Response Object

First We Need To Write into our Memory Stream and then with the help of Memory Stream method "WriteTo" we can write to the Response of the Page as shown in the below code.

   MemoryStream filecontent = null;
   filecontent =//CommonUtility.ExportToPdf(inputXMLtoXSLT);(This will be your MemeoryStream Content)
   Response.ContentType = "image/pdf";
   string headerValue = string.Format("attachment; filename={0}", formName.ToUpper() + ".pdf");
   Response.AppendHeader("Content-Disposition", headerValue);

   filecontent.WriteTo(Response.OutputStream);

   Response.End();

FormName is the fileName given,This code will make the generated PDF file downloadable by invoking a PopUp.

DIV table colspan: how?

<div style="clear:both;"></div> - may do the trick in some cases; not a "colspan" but may help achieve what you are looking for...

<div id="table">
    <div class="table_row">
        <div class="table_cell1"></div>
        <div class="table_cell2"></div>
        <div class="table_cell3"></div>
    </div>
    <div class="table_row">
        <div class="table_cell1"></div>
        <div class="table_cell2"></div>
        <div class="table_cell3"></div>
    </div>

<!-- clear:both will clear any float direction to default, and
prevent the previously defined floats from affecting other elements -->
    <div style="clear:both;"></div>

    <div class="table_row">
<!-- the float is cleared, you could have 4 divs (columns) or
just one with 100% width -->
        <div class="table_cell123"></div>
    </div>
</div>

convert datetime to date format dd/mm/yyyy

string currentdatetime = DateTime.Now.ToString("dd'/'MM'/'yyyy");

A simple jQuery form validation script

you can use jquery validator for that but you need to add jquery.validate.js and jquery.form.js file for that. after including validator file define your validation something like this.

<script type="text/javascript">
$(document).ready(function(){
    $("#formID").validate({
    rules :{
        "data[User][name]" : {
            required : true
        }
    },
    messages :{
        "data[User][name]" : {
            required : 'Enter username'
        }
    }
    });
});
</script>

You can see required : true same there is many more property like for email you can define email : true for number number : true

Select Top and Last rows in a table (SQL server)

To get the bottom 1000 you will want to order it by a column in descending order, and still take the top 1000.

SELECT TOP 1000 *
FROM [SomeTable]
ORDER BY MySortColumn DESC

If you care for it to be in the same order as before you can use a common table expression for that:

;WITH CTE AS (
    SELECT TOP 1000 *
    FROM [SomeTable]
    ORDER BY MySortColumn DESC
)

SELECT * 
FROM CTE
ORDER BY MySortColumn

jQuery - how to write 'if not equal to' (opposite of ==)

== => !=

=== => !==

Equal and its opposite

Visual Studio Post Build Event - Copy to Relative Directory Location

I think this is related, but I had a problem when building directly using msbuild command line (from a batch file) vs building from within VS.

Using something like the following:

<PostBuildEvent>
  MOVE /Y "$(TargetDir)something.file1" "$(ProjectDir)something.file1"
  start XCOPY /Y /R "$(SolutionDir)SomeConsoleApp\bin\$(ConfigurationName)\*" "$(ProjectDir)App_Data\Consoles\SomeConsoleApp\"
</PostBuildEvent>

(note: start XCOPY rather than XCOPY used to get around a permissions issue which prevented copying)

The macro $(SolutionDir) evaluated to ..\ when executing msbuild from a batchfile, which resulted in the XCOPY command failing. It otherwise worked fine when built from within Visual Studio. Confirmed using /verbosity:diagnostic to see the evaluated output.

Using the macro $(ProjectDir)..\ instead, which amounts to the same thing, worked fine and retained the full path in both build scenarios.

Django ChoiceField

First I recommend you as @ChrisHuang-Leaver suggested to define a new file with all the choices you need it there, like choices.py:

STATUS_CHOICES = (
    (1, _("Not relevant")),
    (2, _("Review")),
    (3, _("Maybe relevant")),
    (4, _("Relevant")),
    (5, _("Leading candidate"))
)
RELEVANCE_CHOICES = (
    (1, _("Unread")),
    (2, _("Read"))
)

Now you need to import them on the models, so the code is easy to understand like this(models.py):

from myApp.choices import * 

class Profile(models.Model):
    user = models.OneToOneField(User)    
    status = models.IntegerField(choices=STATUS_CHOICES, default=1)   
    relevance = models.IntegerField(choices=RELEVANCE_CHOICES, default=1)

And you have to import the choices in the forms.py too:

forms.py:

from myApp.choices import * 

class CViewerForm(forms.Form):

    status = forms.ChoiceField(choices = STATUS_CHOICES, label="", initial='', widget=forms.Select(), required=True)
    relevance = forms.ChoiceField(choices = RELEVANCE_CHOICES, required=True)

Anyway you have an issue with your template, because you're not using any {{form.field}}, you generate a table but there is no inputs only hidden_fields.

When the user is staff you should generate as many input fields as users you can manage. I think django form is not the best solution for your situation.

I think it will be better for you to use html form, so you can generate as many inputs using the boucle: {% for user in users_list %} and you generate input with an ID related to the user, and you can manage all of them in the view.

Initialize/reset struct to zero/null

Better than all above is ever to use Standard C specification for struct initialization:

struct StructType structVar = {0};

Here are all bits zero (ever).

Store images in a MongoDB database

http://blog.mongodb.org/post/183689081/storing-large-objects-and-files-in-mongodb

There is a Mongoose plugin available on NPM called mongoose-file. It lets you add a file field to a Mongoose Schema for file upload. I have never used it but it might prove useful. If the images are very small you could Base64 encode them and save the string to the database.

Storing some small (under 1MB) files with MongoDB in NodeJS WITHOUT GridFS

Height equal to dynamic width (CSS fluid layout)

Simple and neet : use vw units for a responsive height/width according to the viewport width.

vw : 1/100th of the width of the viewport. (Source MDN)

DEMO

HTML:

<div></div>

CSS for a 1:1 aspect ratio:

div{
    width:80vw;
    height:80vw; /* same as width */
}

Table to calculate height according to the desired aspect ratio and width of element.

   aspect ratio  |  multiply width by
    -----------------------------------
         1:1      |         1
         1:3      |         3
         4:3      |        0.75
        16:9      |       0.5625

This technique allows you to :

  • insert any content inside the element without using position:absolute;
  • no unecessary HTML markup (only one element)
  • adapt the elements aspect ratio according to the height of the viewport using vh units
  • you can make a responsive square or other aspect ratio that alway fits in viewport according to the height and width of the viewport (see this answer : Responsive square according to width and height of viewport or this demo)

These units are supported by IE9+ see canIuse for more info

Multiple axis line chart in excel

An alternative is to normalize the data. Below are three sets of data with widely varying ranges. In the top chart you can see the variation in one series clearly, in another not so clearly, and the third not at all.

In the second range, I have adjusted the series names to include the data range, using this formula in cell C15 and copying it to D15:E15

=C2&" ("&MIN(C3:C9)&" to "&MAX(C3:C9)&")"

I have normalized the values in the data range using this formula in C15 and copying it to the entire range C16:E22

=100*(C3-MIN(C$3:C$9))/(MAX(C$3:C$9)-MIN(C$3:C$9))

In the second chart, you can see a pattern: all series have a low in January, rising to a high in March, and dropping to medium-low value in June or July.

You can modify the normalizing formula however you need:

=100*C3/MAX(C$3:C$9)

=C3/MAX(C$3:C$9)

=(C3-AVERAGE(C$3:C$9))/STDEV(C$3:C$9)

etc.

Normalizing Data

Count the number of occurrences of each letter in string

One simple possibility would be to make an array of 26 ints, each is a count for a letter a-z:

int alphacount[26] = {0}; //[0] = 'a', [1] = 'b', etc

Then loop through the string and increment the count for each letter:

for(int i = 0; i<strlen(mystring); i++)      //for the whole length of the string
    if(isalpha(mystring[i]))
        alphacount[tolower(mystring[i])-'a']++;  //make the letter lower case (if it's not)
                                                 //then use it as an offset into the array
                                                 //and increment

It's a simple idea that works for A-Z, a-z. If you want to separate by capitals you just need to make the count 52 instead and subtract the correct ASCII offset

What is an uber jar?

ubar jar is also known as fat jar i.e. jar with dependencies.
There are three common methods for constructing an uber jar:

  1. Unshaded: Unpack all JAR files, then repack them into a single JAR. Works with Java's default class loader. Tools maven-assembly-plugin
  2. Shaded: Same as unshaded, but rename (i.e., "shade") all packages of all dependencies. Works with Java's default class loader. Avoids some (not all) dependency version clashes. Tools maven-shade-plugin
  3. JAR of JARs: The final JAR file contains the other JAR files embedded within. Avoids dependency version clashes. All resource files are preserved. Tools: Eclipse JAR File Exporter

for more

Add a border outside of a UIView (instead of inside)

Ok, there already is an accepted answer but I think there is a better way to do it, you just have to had a new layer a bit larger than your view and do not mask it to the bounds of the view's layer (which actually is the default behaviour). Here is the sample code :

CALayer * externalBorder = [CALayer layer];
externalBorder.frame = CGRectMake(-1, -1, myView.frame.size.width+2, myView.frame.size.height+2);
externalBorder.borderColor = [UIColor blackColor].CGColor;
externalBorder.borderWidth = 1.0;

[myView.layer addSublayer:externalBorder];
myView.layer.masksToBounds = NO;

Of course this is if you want your border to be 1 unity large, if you want more you adapt the borderWidth and the frame of the layer accordingly. This is better than using a second view a bit larger as a CALayer is lighter than a UIView and you don't have do modify the frame of myView, which is good for instance if myView is aUIImageView

N.B : For me the result was not perfect on simulator (the layer was not exactly at the right position so the layer was thicker on one side sometimes) but was exactly what is asked for on real device.

EDIT

Actually the problem I talk about in the N.B was just because I had reduced the screen of the simulator, on normal size there is absolutely no issue

Hope it helps

Python Sets vs Lists

Lists are slightly faster than sets when you just want to iterate over the values.

Sets, however, are significantly faster than lists if you want to check if an item is contained within it. They can only contain unique items though.

It turns out tuples perform in almost exactly the same way as lists, except for their immutability.

Iterating

>>> def iter_test(iterable):
...     for i in iterable:
...         pass
...
>>> from timeit import timeit
>>> timeit(
...     "iter_test(iterable)",
...     setup="from __main__ import iter_test; iterable = set(range(10000))",
...     number=100000)
12.666952133178711
>>> timeit(
...     "iter_test(iterable)",
...     setup="from __main__ import iter_test; iterable = list(range(10000))",
...     number=100000)
9.917098999023438
>>> timeit(
...     "iter_test(iterable)",
...     setup="from __main__ import iter_test; iterable = tuple(range(10000))",
...     number=100000)
9.865639209747314

Determine if an object is present

>>> def in_test(iterable):
...     for i in range(1000):
...         if i in iterable:
...             pass
...
>>> from timeit import timeit
>>> timeit(
...     "in_test(iterable)",
...     setup="from __main__ import in_test; iterable = set(range(1000))",
...     number=10000)
0.5591847896575928
>>> timeit(
...     "in_test(iterable)",
...     setup="from __main__ import in_test; iterable = list(range(1000))",
...     number=10000)
50.18339991569519
>>> timeit(
...     "in_test(iterable)",
...     setup="from __main__ import in_test; iterable = tuple(range(1000))",
...     number=10000)
51.597304821014404

How to get a string between two characters?

Use Pattern and Matcher

public class Chk {

    public static void main(String[] args) {

        String s = "test string (67)";
        ArrayList<String> arL = new ArrayList<String>();
        ArrayList<String> inL = new ArrayList<String>();

        Pattern pat = Pattern.compile("\\(\\w+\\)");
        Matcher mat = pat.matcher(s);

        while (mat.find()) {

            arL.add(mat.group());
            System.out.println(mat.group());

        }

        for (String sx : arL) {

            Pattern p = Pattern.compile("(\\w+)");
            Matcher m = p.matcher(sx);

            while (m.find()) {

                inL.add(m.group());
                System.out.println(m.group());
            }
        }

        System.out.println(inL);

    }

}

How to display data from database into textbox, and update it

Wrap your all statements in !IsPostBack condition on page load.

protected void Page_Load(object sender, EventArgs e)
{
   if(!IsPostBack)
   {
      // all statements
   }
}

This will fix your issue.

AngularJS + JQuery : How to get dynamic content working in angularjs

Addition to @jwize's answer

Because angular.element(document).injector() was giving error injector is not defined So, I have created function that you can run after AJAX call or when DOM is changed using jQuery.

  function compileAngularElement( elSelector) {

        var elSelector = (typeof elSelector == 'string') ? elSelector : null ;  
            // The new element to be added
        if (elSelector != null ) {
            var $div = $( elSelector );

                // The parent of the new element
                var $target = $("[ng-app]");

              angular.element($target).injector().invoke(['$compile', function ($compile) {
                        var $scope = angular.element($target).scope();
                        $compile($div)($scope);
                        // Finally, refresh the watch expressions in the new element
                        $scope.$apply();
                    }]);
            }

        }

use it by passing just new element's selector. like this

compileAngularElement( '.user' ) ; 

Convert Date format into DD/MMM/YYYY format in SQL Server

There are already multiple answers and formatting types for SQL server 2008. But this method somewhat ambiguous and it would be difficult for you to remember the number with respect to Specific Date Format. That's why in next versions of SQL server there is better option.

If you are using SQL Server 2012 or above versions, you should use Format() function

FORMAT ( value, format [, culture ] )

With culture option, you can specify date as per your viewers.

DECLARE @d DATETIME = '10/01/2011';
SELECT FORMAT ( @d, 'd', 'en-US' ) AS 'US English Result'
      ,FORMAT ( @d, 'd', 'en-gb' ) AS 'Great Britain English Result'
      ,FORMAT ( @d, 'd', 'de-de' ) AS 'German Result'
      ,FORMAT ( @d, 'd', 'zh-cn' ) AS 'Simplified Chinese (PRC) Result'; 
  
SELECT FORMAT ( @d, 'D', 'en-US' ) AS 'US English Result'
      ,FORMAT ( @d, 'D', 'en-gb' ) AS 'Great Britain English Result'
      ,FORMAT ( @d, 'D', 'de-de' ) AS 'German Result'
      ,FORMAT ( @d, 'D', 'zh-cn' ) AS 'Chinese (Simplified PRC) Result';

US English Result Great Britain English Result  German Result Simplified Chinese (PRC) Result
----------------  ----------------------------- ------------- -------------------------------------
10/1/2011         01/10/2011                    01.10.2011    2011/10/1

US English Result            Great Britain English Result  German Result                    Chinese (Simplified PRC) Result
---------------------------- ----------------------------- -----------------------------  ---------------------------------------
Saturday, October 01, 2011   01 October 2011               Samstag, 1. Oktober 2011        2011?10?1?
   

For OP's solution, we can use following format, which is already mentioned by @Martin Smith:

FORMAT(GETDATE(), 'dd/MMM/yyyy', 'en-us')

Some sample date formats:

enter image description here

If you want more date formats of SQL server, you should visit:

  1. Custom Date and Time Format
  2. Standard Date and Time Format

What is the difference between UTF-8 and ISO-8859-1?

UTF-8 is a multibyte encoding that can represent any Unicode character. ISO 8859-1 is a single-byte encoding that can represent the first 256 Unicode characters. Both encode ASCII exactly the same way.

Jquery Hide table rows

$('inputFile').parent().parent().children('td > label').hide();

can help you navigate two levels up ( to TD, to TR ) moving two levels back down ( all TD's in that TR and their LABEL tags ), applying the hide() function there.

if you want to stay at the TR level and hide them:

$('inputFile').parent().parent().hide();

… is sufficient.

you can navigate very easily through the elements using the jquery selectors.

parent is documented here: http://api.jquery.com/parent/

hide is documented here: http://api.jquery.com/hide/

Converting serial port data to TCP/IP in a Linux environment

You might find Perl or Python useful to get data from the serial port. To send data to the server, the solution could be easy if the server is (let's say) an HTTP application or even a popular database. The solution would be not so easy if it is some custom/proprietary TCP application.

Message 'src refspec master does not match any' when pushing commits in Git

Make sure you've added first, and then commit/ push:

Like:

git init
git add .
git commit -m "message"
git remote add origin "github.com/your_repo.git"
git push -u origin master

What is the best JavaScript code to create an img element

Just for the sake of completeness, I would suggest using the InnerHTML way as well - even though I would not call it the best way...

document.getElementById("image-holder").innerHTML = "<img src='image.png' alt='The Image' />";

By the way, innerHTML is not that bad

In Python, what is the difference between ".append()" and "+= []"?

In the example you gave, there is no difference, in terms of output, between append and +=. But there is a difference between append and + (which the question originally asked about).

>>> a = []
>>> id(a)
11814312
>>> a.append("hello")
>>> id(a)
11814312

>>> b = []
>>> id(b)
11828720
>>> c = b + ["hello"]
>>> id(c)
11833752
>>> b += ["hello"]
>>> id(b)
11828720

As you can see, append and += have the same result; they add the item to the list, without producing a new list. Using + adds the two lists and produces a new list.

How to resolve git error: "Updates were rejected because the tip of your current branch is behind"

I had this issue and I realized that .gitignore file is changed. So, I changed .gitignore and I could pull the changes.

SQL Server 2008 Row Insert and Update timestamps

try

CREATE TABLE [dbo].[Names]
(
    [Name] [nvarchar](64) NOT NULL,
    [CreateTS] [smalldatetime] NOT NULL CONSTRAINT CreateTS_DF DEFAULT CURRENT_TIMESTAMP,
    [UpdateTS] [smalldatetime] NOT NULL

)

PS I think a smalldatetime is good enough. You may decide differently.

Can you not do this at the "moment of impact" ?

In Sql Server, this is common:

Update dbo.MyTable 
Set 

ColA = @SomeValue , 
UpdateDS = CURRENT_TIMESTAMP
Where...........

Sql Server has a "timestamp" datatype.

But it may not be what you think.

Here is a reference:

http://msdn.microsoft.com/en-us/library/ms182776(v=sql.90).aspx

Here is a little RowVersion (synonym for timestamp) example:

CREATE TABLE [dbo].[Names]
(
    [Name] [nvarchar](64) NOT NULL,
    RowVers rowversion ,
    [CreateTS] [datetime] NOT NULL CONSTRAINT CreateTS_DF DEFAULT CURRENT_TIMESTAMP,
    [UpdateTS] [datetime] NOT NULL

)


INSERT INTO dbo.Names (Name,UpdateTS)
select 'John' , CURRENT_TIMESTAMP
UNION ALL select 'Mary' , CURRENT_TIMESTAMP
UNION ALL select 'Paul' , CURRENT_TIMESTAMP

select *  ,  ConvertedRowVers = CONVERT(bigint,RowVers) from [dbo].[Names]

Update dbo.Names Set Name = Name

select *  ,  ConvertedRowVers = CONVERT(bigint,RowVers) from [dbo].[Names]

Maybe a complete working example:

DROP TABLE [dbo].[Names]
GO


CREATE TABLE [dbo].[Names]
(
    [Name] [nvarchar](64) NOT NULL,
    RowVers rowversion ,
    [CreateTS] [datetime] NOT NULL CONSTRAINT CreateTS_DF DEFAULT CURRENT_TIMESTAMP,
    [UpdateTS] [datetime] NOT NULL

)

GO

CREATE TRIGGER dbo.trgKeepUpdateDateInSync_ByeByeBye ON dbo.Names
AFTER INSERT, UPDATE
AS

BEGIN

Update dbo.Names Set UpdateTS = CURRENT_TIMESTAMP from dbo.Names myAlias , inserted triggerInsertedTable where 
triggerInsertedTable.Name = myAlias.Name

END


GO






INSERT INTO dbo.Names (Name,UpdateTS)
select 'John' , CURRENT_TIMESTAMP
UNION ALL select 'Mary' , CURRENT_TIMESTAMP
UNION ALL select 'Paul' , CURRENT_TIMESTAMP

select *  ,  ConvertedRowVers = CONVERT(bigint,RowVers) from [dbo].[Names]

Update dbo.Names Set Name = Name , UpdateTS = '03/03/2003' /* notice that even though I set it to 2003, the trigger takes over */

select *  ,  ConvertedRowVers = CONVERT(bigint,RowVers) from [dbo].[Names]

Matching on the "Name" value is probably not wise.

Try this more mainstream example with a SurrogateKey

DROP TABLE [dbo].[Names]
GO


CREATE TABLE [dbo].[Names]
(
    SurrogateKey int not null Primary Key Identity (1001,1),
    [Name] [nvarchar](64) NOT NULL,
    RowVers rowversion ,
    [CreateTS] [datetime] NOT NULL CONSTRAINT CreateTS_DF DEFAULT CURRENT_TIMESTAMP,
    [UpdateTS] [datetime] NOT NULL

)

GO

CREATE TRIGGER dbo.trgKeepUpdateDateInSync_ByeByeBye ON dbo.Names
AFTER UPDATE
AS

BEGIN

   UPDATE dbo.Names
    SET UpdateTS = CURRENT_TIMESTAMP
    From  dbo.Names myAlias
    WHERE exists ( select null from inserted triggerInsertedTable where myAlias.SurrogateKey = triggerInsertedTable.SurrogateKey)

END


GO






INSERT INTO dbo.Names (Name,UpdateTS)
select 'John' , CURRENT_TIMESTAMP
UNION ALL select 'Mary' , CURRENT_TIMESTAMP
UNION ALL select 'Paul' , CURRENT_TIMESTAMP

select *  ,  ConvertedRowVers = CONVERT(bigint,RowVers) from [dbo].[Names]

Update dbo.Names Set Name = Name , UpdateTS = '03/03/2003' /* notice that even though I set it to 2003, the trigger takes over */

select *  ,  ConvertedRowVers = CONVERT(bigint,RowVers) from [dbo].[Names]

Is there a difference between "throw" and "throw ex"?

The other answers are entirely correct, but this answer provides some extra detalis, I think.

Consider this example:

using System;

static class Program {
  static void Main() {
    try {
      ThrowTest();
    } catch (Exception e) {
      Console.WriteLine("Your stack trace:");
      Console.WriteLine(e.StackTrace);
      Console.WriteLine();
      if (e.InnerException == null) {
        Console.WriteLine("No inner exception.");
      } else {
        Console.WriteLine("Stack trace of your inner exception:");
        Console.WriteLine(e.InnerException.StackTrace);
      }
    }
  }

  static void ThrowTest() {
    decimal a = 1m;
    decimal b = 0m;
    try {
      Mult(a, b);  // line 34
      Div(a, b);   // line 35
      Mult(b, a);  // line 36
      Div(b, a);   // line 37
    } catch (ArithmeticException arithExc) {
      Console.WriteLine("Handling a {0}.", arithExc.GetType().Name);

      //   uncomment EITHER
      //throw arithExc;
      //   OR
      //throw;
      //   OR
      //throw new Exception("We handled and wrapped your exception", arithExc);
    }
  }

  static void Mult(decimal x, decimal y) {
    decimal.Multiply(x, y);
  }
  static void Div(decimal x, decimal y) {
    decimal.Divide(x, y);
  }
}

If you uncomment the throw arithExc; line, your output is:

Handling a DivideByZeroException.
Your stack trace:
   at Program.ThrowTest() in c:\somepath\Program.cs:line 44
   at Program.Main() in c:\somepath\Program.cs:line 9

No inner exception.

Certainly, you have lost information about where that exception happened. If instead you use the throw; line, this is what you get:

Handling a DivideByZeroException.
Your stack trace:
   at System.Decimal.FCallDivide(Decimal& d1, Decimal& d2)
   at System.Decimal.Divide(Decimal d1, Decimal d2)
   at Program.Div(Decimal x, Decimal y) in c:\somepath\Program.cs:line 58
   at Program.ThrowTest() in c:\somepath\Program.cs:line 46
   at Program.Main() in c:\somepath\Program.cs:line 9

No inner exception.

This is a lot better, because now you see that it was the Program.Div method that caused you problems. But it's still hard to see if this problem comes from line 35 or line 37 in the try block.

If you use the third alternative, wrapping in an outer exception, you lose no information:

Handling a DivideByZeroException.
Your stack trace:
   at Program.ThrowTest() in c:\somepath\Program.cs:line 48
   at Program.Main() in c:\somepath\Program.cs:line 9

Stack trace of your inner exception:
   at System.Decimal.FCallDivide(Decimal& d1, Decimal& d2)
   at System.Decimal.Divide(Decimal d1, Decimal d2)
   at Program.Div(Decimal x, Decimal y) in c:\somepath\Program.cs:line 58
   at Program.ThrowTest() in c:\somepath\Program.cs:line 35

In particular you can see that it's line 35 that leads to the problem. However, this requires people to search the InnerException, and it feels somewhat indirect to use inner exceptions in simple cases.

In this blog post they preserve the line number (line of the try block) by calling (through reflection) the internal intance method InternalPreserveStackTrace() on the Exception object. But it's not nice to use reflection like that (the .NET Framework might change their internal members some day without warning).

VBA for filtering columns

Here's a different approach. The heart of it was created by turning on the Macro Recorder and filtering the columns per your specifications. Then there's a bit of code to copy the results. It will run faster than looping through each row and column:

Sub FilterAndCopy()
Dim LastRow As Long

Sheets("Sheet2").UsedRange.Offset(0).ClearContents
With Worksheets("Sheet1")
    .Range("$A:$E").AutoFilter
    .Range("$A:$E").AutoFilter field:=1, Criteria1:="#N/A"
    .Range("$A:$E").AutoFilter field:=2, Criteria1:="=String1", Operator:=xlOr, Criteria2:="=string2"
    .Range("$A:$E").AutoFilter field:=3, Criteria1:=">0"
    .Range("$A:$E").AutoFilter field:=5, Criteria1:="Number"
    LastRow = .Range("A" & .Rows.Count).End(xlUp).Row
    .Range("A1:A" & LastRow).SpecialCells(xlCellTypeVisible).EntireRow.Copy _
            Destination:=Sheets("Sheet2").Range("A1")
End With
End Sub

As a side note, your code has more loops and counter variables than necessary. You wouldn't need to loop through the columns, just through the rows. You'd then check the various cells of interest in that row, much like you did.

How do I stop a web page from scrolling to the top when a link is clicked that triggers JavaScript?

When calling the function, follow it by return false example:

<input  type="submit" value="Add" onclick="addNewPayment();return false;">

No space left on device

Such difference between the output of du -sh and df -h may happen if some large file has been deleted, but is still opened by some process. Check with the command lsof | grep deleted to see which processes have opened descriptors to deleted files. You can restart the process and the space will be freed.

How do I specify the platform for MSBuild?

There is an odd case I got in VS2017, about the space between ‘Any’ and 'CPU'. this is not about using command prompt.

If you have a build project file, which could call other solution files. You can try to add the space between Any and CPU, like this (the Platform property value):

<MSBuild Projects="@(SolutionToBuild2)" Properties ="Configuration=$(ProjectConfiguration);Platform=Any CPU;Rerun=$(MsBuildReRun);" />

Before I fix this build issue, it is like this (ProjectPlatform is a global variable, was set to 'AnyCPU'):

<MSBuild Projects="@(SolutionToBuild1)" Properties ="Configuration=$(ProjectConfiguration);Platform=$(ProjectPlatform);Rerun=$(MsBuildReRun);" />

Also, we have a lot projects being called using $ (ProjectPlatform), which is 'AnyCPU' and work fine. If we open proj file, we can see lines liket this and it make sense.

<PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|AnyCPU'">

So my conclusion is, 'AnyCPU' works for calling project files, but not for calling solution files, for calling solution files, using 'Any CPU' (add the space.)

For now, I am not sure if it is a bug of VS project file or MSBuild. I am using VS2017 with VS2017 build tools installed.

How to filter for multiple criteria in Excel?

Maybe not as elegant but another possibility would be to write a formula to do the check and fill it in an adjacent column. You could then filter on that column.

The following looks in cell b14 and would return true for all the file types you mention. This assumes that the file extension is by itself in the column. If it's not it would be a little more complicated but you could still do it this way.

=OR(B14=".pdf",B14=".doc",B14=".docx",B14=".xls",B14=".xlsx",B14=".rtf",B14=".txt",B14=".csv",B14=".pps")

Like I said, not as elegant as the advanced filters but options are always good.

Java equivalent to #region in C#

AndroidStudio region
Create region

First, find (and define short cut if need) for Surround With menu enter image description here

Then, select the code, press Ctrl+Alt+Semicolon -> choose region..endregion...
enter image description here

Go to region

First, find Custom Folding short cut
enter image description here Second, from anywhere in your code, press Ctrl+Alt+Period('>' on keyboard) enter image description here

Find the least number of coins required that can make any change from 1 to 99 cents

Solution with greedy approach in java is as below :

public class CoinChange {
    public static void main(String args[]) {
        int denominations[] = {1, 5, 10, 25};
        System.out.println("Total required coins are " + greeadApproach(53, denominations));
    }

    public static int greeadApproach(int amount, int denominations[]) {
        int cnt[] = new int[denominations.length];
        for (int i = denominations.length-1; amount > 0 && i >= 0; i--) {
            cnt[i] = (amount/denominations[i]);
            amount -= cnt[i] * denominations[i];            
        }
        int noOfCoins = 0;
        for (int cntVal : cnt) {
            noOfCoins+= cntVal;
        }
        return noOfCoins;
    }
}

But this works for single amount. If you want to run it for range, than we have to call it for each amount of range.

How can I extract a number from a string in JavaScript?

You need to add "(/\d+/g)" which will remove all non-number text, but it will still be a string at this point. If you create a variable and "parseInt" through the match, you can set the new variables to the array values. Here is an example of how I got it to work:

    var color = $( this ).css( "background-color" );
    var r = parseInt(color.match(/\d+/g)[0]);
    var g = parseInt(color.match(/\d+/g)[1]);
    var b = parseInt(color.match(/\d+/g)[2]);

Configuring so that pip install can work from github

Clone target repository same way like you cloning any other project:

git clone [email protected]:myuser/foo.git

Then install it in develop mode:

cd foo
pip install -e .

You can change anything you wan't and every code using foo package will use modified code.

There 2 benefits ot this solution:

  1. You can install package in your home projects directory.
  2. Package includes .git dir, so it's regular Git repository. You can push to your fork right away.

Convert list or numpy array of single element to float in python

Use numpy.asscalar to convert a numpy array / matrix a scalar value:

>>> a=numpy.array([[[[42]]]])
>>> numpy.asscalar(a)
42

The output data type is the same type returned by the input’s item method.

It has built in error-checking if there is more than an single element:

>>> a=numpy.array([1, 2])
>>> numpy.asscalar(a)

gives:

ValueError: can only convert an array of size 1 to a Python scalar

Note: the object passed to asscalar must respond to item, so passing a list or tuple won't work.

How to create an 2D ArrayList in java?

1st of all, when you declare a variable in java, you should declare it using Interfaces even if you specify the implementation when instantiating it

ArrayList<ArrayList<String>> listOfLists = new ArrayList<ArrayList<String>>();

should be written

List<List<String>> listOfLists = new ArrayList<List<String>>(size); 

Then you will have to instantiate all columns of your 2d array

    for(int i = 0; i < size; i++)  {
        listOfLists.add(new ArrayList<String>());
    }

And you will use it like this :

listOfLists.get(0).add("foobar");

But if you really want to "create a 2D array that each cell is an ArrayList!"

Then you must go the dijkstra way.

When to use single quotes, double quotes, and backticks in MySQL

There has been many helpful answers here, generally culminating into two points.

  1. BACKTICKS(`) are used around identifier names.
  2. SINGLE QUOTES(') are used around values.

AND as @MichaelBerkowski said

Backticks are to be used for table and column identifiers, but are only necessary when the identifier is a MySQL reserved keyword, or when the identifier contains whitespace characters or characters beyond a limited set (see below) It is often recommended to avoid using reserved keywords as column or table identifiers when possible, avoiding the quoting issue.

There is a case though where an identifier can neither be a reserved keyword or contain whitespace or characters beyond limited set but necessarily require backticks around them.

EXAMPLE

123E10 is a valid identifier name but also a valid INTEGER literal.

[Without going into detail how you would get such an identifier name], Suppose I want to create a temporary table named 123456e6.

No ERROR on backticks.

DB [XXX]> create temporary table `123456e6` (`id` char (8));
Query OK, 0 rows affected (0.03 sec)

ERROR when not using backticks.

DB [XXX]> create temporary table 123451e6 (`id` char (8));
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '123451e6 (`id` char (8))' at line 1

However, 123451a6 is a perfectly fine identifier name (without back ticks).

DB [XXX]> create temporary table 123451a6 (`id` char (8));
Query OK, 0 rows affected (0.03 sec)

This is completely because 1234156e6 is also an exponential number.

GoogleMaps API KEY for testing

Updated Answer

As of June11, 2018 it is now mandatory to have a billing account to get API key. You can still make keyless calls to the Maps JavaScript API and Street View Static API which will return low-resolution maps that can be used for development. Enabling billing still gives you $200 free credit monthly for your projects.

This answer is no longer valid

As long as you're using a testing API key it is free to register and use. But when you move your app to commercial level you have to pay for it. When you enable billing, google gives you $200 credit free each month that means if your app's map usage is low you can still use it for free even after the billing enabled, if it exceeds the credit limit now you have to pay for it.