Programs & Examples On #Broadcast

A broadcast is a one-to-many message passing interface. It is usually used in the context of a network programming or event-driven programming.

How to set java.net.preferIPv4Stack=true at runtime?

you can set the environment variable JAVA_TOOL_OPTS like as follows, which will be picked by JVM for any application.

set JAVA_TOOL_OPTS=-Djava.net.preferIPv4Stack=true

You can set this from the command prompt or set in system environment variables, based on your need. Note that this will reflect into all the java applications that run in your machine, even if it's a java interpreter that you have in a private setup.

javax.faces.application.ViewExpiredException: View could not be restored

First what you have to do, before changing web.xml is to make sure your ManagedBean implements Serializable:

@ManagedBean
@ViewScoped
public class Login implements Serializable {
}

Especially if you use MyFaces

ClassCastException, casting Integer to Double

Integer x=10;
Double y = x.doubleValue();

Is Constructor Overriding Possible?

While others have pointed out it is not possible to override constructors syntactically, I would like to also point out, it would be conceptually bad to do so. Say the superclass is a dog object, and the subclass is a Husky object. The dog object has properties such as "4 legs", "sharp nose", if "override" means erasing dog and replacing it with Husky then Husky would be missing these properties and be a broken object. Husky never had those properties and simply inherited them from dog. On the other hand, if you intend to give Husky everything that dog has, then conceptually you could "override" dog with Husky, but there would be no point in creating a class that is the same as dog, it's not practically an inherited class but a complete replacement.

Check if something is (not) in a list in Python

How do I check if something is (not) in a list in Python?

The cheapest and most readable solution is using the in operator (or in your specific case, not in). As mentioned in the documentation,

The operators in and not in test for membership. x in s evaluates to True if x is a member of s, and False otherwise. x not in s returns the negation of x in s.

Additionally,

The operator not in is defined to have the inverse true value of in.

y not in x is logically the same as not y in x.

Here are a few examples:

'a' in [1, 2, 3]
# False

'c' in ['a', 'b', 'c']
# True

'a' not in [1, 2, 3]
# True

'c' not in ['a', 'b', 'c']
# False

This also works with tuples, since tuples are hashable (as a consequence of the fact that they are also immutable):

(1, 2) in [(3, 4), (1, 2)]
#  True

If the object on the RHS defines a __contains__() method, in will internally call it, as noted in the last paragraph of the Comparisons section of the docs.

... in and not in, are supported by types that are iterable or implement the __contains__() method. For example, you could (but shouldn't) do this:

[3, 2, 1].__contains__(1)
# True

in short-circuits, so if your element is at the start of the list, in evaluates faster:

lst = list(range(10001))
%timeit 1 in lst
%timeit 10000 in lst  # Expected to take longer time.

68.9 ns ± 0.613 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)
178 µs ± 5.01 µs per loop (mean ± std. dev. of 7 runs, 10000 loops each)

If you want to do more than just check whether an item is in a list, there are options:

  • list.index can be used to retrieve the index of an item. If that element does not exist, a ValueError is raised.
  • list.count can be used if you want to count the occurrences.

The XY Problem: Have you considered sets?

Ask yourself these questions:

  • do you need to check whether an item is in a list more than once?
  • Is this check done inside a loop, or a function called repeatedly?
  • Are the items you're storing on your list hashable? IOW, can you call hash on them?

If you answered "yes" to these questions, you should be using a set instead. An in membership test on lists is O(n) time complexity. This means that python has to do a linear scan of your list, visiting each element and comparing it against the search item. If you're doing this repeatedly, or if the lists are large, this operation will incur an overhead.

set objects, on the other hand, hash their values for constant time membership check. The check is also done using in:

1 in {1, 2, 3} 
# True

'a' not in {'a', 'b', 'c'}
# False

(1, 2) in {('a', 'c'), (1, 2)}
# True

If you're unfortunate enough that the element you're searching/not searching for is at the end of your list, python will have scanned the list upto the end. This is evident from the timings below:

l = list(range(100001))
s = set(l)

%timeit 100000 in l
%timeit 100000 in s

2.58 ms ± 58.9 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)
101 ns ± 9.53 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)

As a reminder, this is a suitable option as long as the elements you're storing and looking up are hashable. IOW, they would either have to be immutable types, or objects that implement __hash__.

Change MySQL default character set to UTF-8 in my.cnf?

NijaCat was close, but specified overkill:

To set the default to UTF-8, you want to add the following to my.cnf

[client]
default-character-set=utf8

[mysqld]
default-character-set = utf8

Then, to verify:

mysql> show variables like "%character%";show variables like "%collation%";

+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       |
| character_set_connection | utf8                       |
| character_set_database   | utf8                       |
| character_set_filesystem | binary                     |
| character_set_results    | utf8                       |
| character_set_server     | utf8                       |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)

+----------------------+-----------------+
| Variable_name        | Value           |
+----------------------+-----------------+
| collation_connection | utf8_general_ci |
| collation_database   | utf8_general_ci |
| collation_server     | utf8_general_ci |
+----------------------+-----------------+
3 rows in set (0.00 sec)

jQuery adding 2 numbers from input fields

This code works, can you compare it with yours?

<!DOCTYPE html>
<html lang="en-US">
<head>
    <title>HTML Tutorial</title>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
    <meta charset="windows-1252">
<script>

$(document).ready(function(){
    var a = $("#a").val();
    var b = $("#b").val();   
    $("#submit").on("click", function(){
        var sum = a + b;
        alert(sum);         
    })
})
</script>
</head>
<body>
   <input type="text" id="a" name="option"> 
   <input type="text" id="b" name="task"> 
<input id="submit" type="button" value="press me">

</body>

</html>

How to make <input type="date"> supported on all browsers? Any alternatives?

   <script>
      var datefield = document.createElement("input")
      datefield.setAttribute("type", "date")
      if (datefield.type != "date") { // if browser doesn't support input type="date", load files for jQuery UI Date Picker
         document.write('<link href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/base/jquery-ui.css" rel="stylesheet" type="text/css" />\n')
         document.write('<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js"><\/script>\n')
         document.write('<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js"><\/script>\n')
      }
   </script>

 <script>
    if (datefield.type != "date") { // if browser doesn't support input type="date", initialize date picker widget:
       jQuery(function($) { // on document.ready
           $('#birthday').datepicker();
       }); <- missing semicolon
    }
 </script>

<body>
 <form>
   <b>Date of birth:</b>
   <input type="date" id="birthday" name="birthday" size="20">
   <input type="button" value="Submit" name="B1">
 </form>
</body>

SOURCE 1 & SOURCE 2

What is the difference between static func and class func in Swift?

Is it simply that static is for static functions of structs and enums, and class for classes and protocols?

That's the main difference. Some other differences are that class functions are dynamically dispatched and can be overridden by subclasses.

Protocols use the class keyword, but it doesn't exclude structs from implementing the protocol, they just use static instead. Class was chosen for protocols so there wouldn't have to be a third keyword to represent static or class.

From Chris Lattner on this topic:

We considered unifying the syntax (e.g. using "type" as the keyword), but that doesn't actually simply things. The keywords "class" and "static" are good for familiarity and are quite descriptive (once you understand how + methods work), and open the door for potentially adding truly static methods to classes. The primary weirdness of this model is that protocols have to pick a keyword (and we chose "class"), but on balance it is the right tradeoff.

And here's a snippet that shows some of the override behavior of class functions:

class MyClass {
    class func myFunc() {
        println("myClass")
    }
}

class MyOtherClass: MyClass {
    override class func myFunc() {
        println("myOtherClass")
    }
}

var x: MyClass = MyOtherClass()
x.dynamicType.myFunc() //myOtherClass
x = MyClass()
x.dynamicType.myFunc() //myClass

MySQL INNER JOIN select only one row from second table

You need to have a subquery to get their latest date per user ID.

SELECT  a.*, c.*
FROM users a 
    INNER JOIN payments c
        ON a.id = c.user_ID
    INNER JOIN
    (
        SELECT user_ID, MAX(date) maxDate
        FROM payments
        GROUP BY user_ID
    ) b ON c.user_ID = b.user_ID AND
            c.date = b.maxDate
WHERE a.package = 1

QED symbol in latex

If you \usepackage{amsmath}, the \blacksquare command will typeset a solid black square. The \square command will give you a hollow square.

The ulsy package has a few version of the lightning bolt for contradictions: \blitza, \blitzb, ..., \blitze. Just drop \usepackage{ulsy} into the preamble of your document.

Finally, as others have pointed out, the Comprehensive LaTeX Symbols List is a great resource for finding the perfect symbol for the job.

Assign a variable inside a Block to a variable outside a Block

Just use the __block prefix to declare and assign any type of variable inside a block.

For example:

__block Person *aPerson = nil;

__block NSString *name = nil;

How to create number input field in Flutter?

You can use this two attributes together with TextFormField

 TextFormField(
         keyboardType: TextInputType.number
         inputFormatters: [WhitelistingTextInputFormatter.digitsOnly],

It's allow to put only numbers, no thing else ..

https://api.flutter.dev/flutter/services/TextInputFormatter-class.html

How to remove/ignore :hover css style on touch devices

Try this (i use background and background-color in this example):

var ClickEventType = ((document.ontouchstart !== null) ? 'click' : 'touchstart');

if (ClickEventType == 'touchstart') {
            $('a').each(function() { // save original..
                var back_color = $(this).css('background-color');
                var background = $(this).css('background');
                $(this).attr('data-back_color', back_color);
                $(this).attr('data-background', background);
            });

            $('a').on('touchend', function(e) { // overwrite with original style..
                var background = $(this).attr('data-background');
                var back_color = $(this).attr('data-back_color');
                if (back_color != undefined) {
                    $(this).css({'background-color': back_color});
                }
                if (background != undefined) {
                    $(this).css({'background': background});
                }
            }).on('touchstart', function(e) { // clear added stlye="" elements..
                $(this).css({'background': '', 'background-color': ''});
            });
}

css:

a {
    -webkit-touch-callout: none;
    -webkit-tap-highlight-color: transparent;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

How to skip the OPTIONS preflight request?

setting the content-type to undefined would make javascript pass the header data As it is , and over writing the default angular $httpProvider header configurations. Angular $http Documentation

$http({url:url,method:"POST", headers:{'Content-Type':undefined}).then(success,failure);

UICollectionView Self Sizing Cells with Auto Layout

  1. Add flowLayout on viewDidLoad()

    override func viewDidLoad() {
        super.viewDidLoad() 
        if let flowLayout = infoCollection.collectionViewLayout as? UICollectionViewFlowLayout {
            flowLayout.estimatedItemSize = CGSize(width: 1, height:1)
        }
    }
    
  2. Also, set an UIView as mainContainer for your cell and add all required views inside it.

  3. Refer to this awesome, mind-blowing tutorial for further reference: UICollectionView with autosizing cell using autolayout in iOS 9 & 10

TypeError: document.getElementbyId is not a function

JavaScript is case-sensitive. The b in getElementbyId should be capitalized.

var content = document.getElementById("edit").innerHTML;

Javascript format date / time

Please do not reinvent the wheel. There are many open-source & COTS solutions that already exist to solve this problem.

Please take a look at the following JavaScript libraries:


Demo

I wrote a one-liner using Moment.js below. You can check out the demo here: JSFiddle.

moment('2014-08-20 15:30:00').format('MM/DD/YYYY h:mm a'); // 08/20/2014 3:30 pm

Delete all rows in a table based on another table

DELETE Table1
FROM Table1
INNER JOIN Table2 ON Table1.ID = Table2.ID

python ValueError: invalid literal for float()

I would all but guarantee that the issue is some sort of non-printing character that's present in the value you pulled off your socket. It looks like you're using Python 2.x, in which case you can check for them with this:

print repr(temp)

You'll likely see something in there that's escaped in the form \x00. These non-printing characters don't show up when you print directly to the console, but their presence is enough to negatively impact the parsing of a string value into a float.

-- Edited for question changes --

It turns this is partly accurate for your issue - the root cause however appears to be that you're reading more information than you expect from your socket or otherwise receiving multiple values. You could do something like

map(float, temp.strip().split('\r\n'))

In order to convert each of the values, but if your function is supposed to return a single float value this is likely to cause confusion. Anyway, the issue certainly revolves around the presence of characters you did not expect to see in the value you retrieved from your socket.

Usage of $broadcast(), $emit() And $on() in AngularJS

$emit

It dispatches an event name upwards through the scope hierarchy and notify to the registered $rootScope.Scope listeners. The event life cycle starts at the scope on which $emit was called. The event traverses upwards toward the root scope and calls all registered listeners along the way. The event will stop propagating if one of the listeners cancels it.

$broadcast

It dispatches an event name downwards to all child scopes (and their children) and notify to the registered $rootScope.Scope listeners. The event life cycle starts at the scope on which $broadcast was called. All listeners for the event on this scope get notified. Afterwards, the event traverses downwards toward the child scopes and calls all registered listeners along the way. The event cannot be canceled.

$on

It listen on events of a given type. It can catch the event dispatched by $broadcast and $emit.


Visual demo:

Demo working code, visually showing scope tree (parent/child relationship):
http://plnkr.co/edit/am6IDw?p=preview

Demonstrates the method calls:

  $scope.$on('eventEmitedName', function(event, data) ...
  $scope.broadcastEvent
  $scope.emitEvent

push object into array

You have to create an object. Assign the values to the object. Then push it into the array:

var nietos = [];
var obj = {};
obj["01"] = nieto.label;
obj["02"] = nieto.value;
nietos.push(obj);

jQuery first child of "this"

element.children().first();

Find all children and get first of them.

join on multiple columns

Below is the structure of SQL that you may write. You can do multiple joins by using "AND" or "OR".

Select TableA.Col1, TableA.Col2, TableB.Val
FROM TableA, 
INNER JOIN TableB
 ON TableA.Col1 = TableB.Col1 OR TableA.Col2 = TableB.Col2

How to generate class diagram from project in Visual Studio 2013?

For creating real UML class diagrams:

In Visual Studio 2013 Ultimate you can do this without any external tools.

  • In the menu, click on Architecture, New Diagram Select UML Class Diagram
  • This will ask you to create a new Modeling Project if you don't have one already.

You will have a empty UMLClassDiagram.classdiagram.

  • Again, go to Architecture, Windows, Architecture Explorer.
  • A window will pop up with your namespaces, Choose Class View.
  • Then a list of sub-namespaces will appear, if any. Choose one, select the classes and drag them to the empty UMLClassDiagram1.classdiagram window.

Reference: Create UML Class Diagrams from Code

Scroll / Jump to id without jQuery

Add the function:

function scrollToForm() {
  document.querySelector('#form').scrollIntoView({behavior: 'smooth'});
}

Trigger the function:

<a href="javascript: scrollToForm();">Jump to form</a>

Mac zip compress without __MACOSX folder?

Can be fixed after the fact by zip -d filename.zip __MACOSX/\*

Find integer index of rows with NaN in pandas dataframe

For DataFrame df:

import numpy as np
index = df['b'].index[df['b'].apply(np.isnan)]

will give you back the MultiIndex that you can use to index back into df, e.g.:

df['a'].ix[index[0]]
>>> 1.452354

For the integer index:

df_index = df.index.values.tolist()
[df_index.index(i) for i in index]
>>> [3, 6]

Removing duplicates from a SQL query (not just "use distinct")

Arbitrarily choosing to keep the minimum PIC_ID. Also, avoid using the implicit join syntax.

SELECT U.NAME, MIN(P.PIC_ID)
    FROM USERS U
        INNER JOIN POSTINGS P1
            ON U.EMAIL_ID = P1.EMAIL_ID
        INNER JOIN PICTURES P
            ON P1.PIC_ID = P.PIC_ID
    WHERE P.CAPTION LIKE '%car%'
    GROUP BY U.NAME;

Clearing content of text file using C#

Another short version:

System.IO.File.WriteAllBytes(path, new byte[0]);

How do I convert from stringstream to string in C++?

From memory, you call stringstream::str() to get the std::string value out.

How do I capitalize first letter of first name and last name in C#?

Mc and Mac are common surname prefixes throughout the US, and there are others. TextInfo.ToTitleCase doesn't handle those cases and shouldn't be used for this purpose. Here's how I'm doing it:

    public static string ToTitleCase(string str)
    {
        string result = str;
        if (!string.IsNullOrEmpty(str))
        {
            var words = str.Split(' ');
            for (int index = 0; index < words.Length; index++)
            {
                var s = words[index];
                if (s.Length > 0)
                {
                    words[index] = s[0].ToString().ToUpper() + s.Substring(1);
                }
            }
            result = string.Join(" ", words);
        }
        return result;
    }

json.dump throwing "TypeError: {...} is not JSON serializable" on seemingly valid object?

I wrote a class to normalize the data in my dictionary. The 'element' in the NormalizeData class below, needs to be of dict type. And you need to replace in the __iterate() with either your custom class object or any other object type that you would like to normalize.

class NormalizeData:

    def __init__(self, element):
        self.element = element

    def execute(self):
        if isinstance(self.element, dict):
            self.__iterate()
        else:
            return

    def __iterate(self):
        for key in self.element:
            if isinstance(self.element[key], <ClassName>):
                self.element[key] = str(self.element[key])

            node = NormalizeData(self.element[key])
            node.execute()

Pythonic way to return list of every nth item in a larger list

  1. source_list[::10] is the most obvious, but this doesn't work for any iterable and is not memory efficient for large lists.
  2. itertools.islice(source_sequence, 0, None, 10) works for any iterable and is memory-efficient, but probably is not the fastest solution for large list and big step.
  3. (source_list[i] for i in xrange(0, len(source_list), 10))

Android Studio doesn't see device

As driver was unable to load, I was unable to connect to my device on windows 7. I followed the steps below:

  1. Download Android USB driver from Intel site
  2. Install the driver and reboot your system
  3. Connect your device and it worked

What is the Python equivalent for a case/switch statement?

The direct replacement is if/elif/else.

However, in many cases there are better ways to do it in Python. See "Replacements for switch statement in Python?".

Git: "Not currently on any branch." Is there an easy way to get back on a branch, while keeping the changes?

this helped me

git checkout -b newbranch
git checkout master
git merge newbranch
git branch -d newbranch

SQL like search string starts with

Aside from using %, age of empires III to lower case is age of empires iii so your query should be:

select *
from games
where lower(title) like 'age of empires iii%'

Extract file basename without path and extension in bash

If you want to play nice with Windows file paths (under Cygwin) you can also try this:

fname=${fullfile##*[/|\\]}

This will account for backslash separators when using BaSH on Windows.

CSS / HTML Navigation and Logo on same line

Firstly, let's use some semantic HTML.

<nav class="navigation-bar">
    <img class="logo" src="logo.png">
    <ul>
        <li><a href="#">Home</a></li>
        <li><a href="#">Projects</a></li>
        <li><a href="#">About</a></li>
        <li><a href="#">Services</a></li>
        <li><a href="#">Get in Touch</a></li>
    </ul>
</nav>

In fact, you can even get away with the more minimalist:

<nav class="navigation-bar">
    <img class="logo" src="logo.png">
    <a href="#">Home</a>
    <a href="#">Projects</a>
    <a href="#">About</a>
    <a href="#">Services</a>
    <a href="#">Get in Touch</a>
</nav>

Then add some CSS:

.navigation-bar {
    width: 100%;  /* i'm assuming full width */
    height: 80px; /* change it to desired width */
    background-color: red; /* change to desired color */
}
.logo {
    display: inline-block;
    vertical-align: top;
    width: 50px;
    height: 50px;
    margin-right: 20px;
    margin-top: 15px;    /* if you want it vertically middle of the navbar. */
}
.navigation-bar > a {
    display: inline-block;
    vertical-align: top;
    margin-right: 20px;
    height: 80px;        /* if you want it to take the full height of the bar */
    line-height: 80px;    /* if you want it vertically middle of the navbar */
}

Obviously, the actual margins, heights and line-heights etc. depend on your design.

Other options are to use tables or floats for layout, but these are generally frowned upon.

Last but not least, I hope you get cured of div-itis.

How to get a random value from dictionary?

b = { 'video':0, 'music':23,"picture":12 } 
random.choice(tuple(b.items())) ('music', 23) 
random.choice(tuple(b.items())) ('music', 23) 
random.choice(tuple(b.items())) ('picture', 12) 
random.choice(tuple(b.items())) ('video', 0) 

Accessing localhost (xampp) from another computer over LAN network - how to?

Replace Require Local with Require all granted in xampp\apache\conf\extra\httpd-xampp.conf file.

How do I add a new sourceset to Gradle?

Here's what works for me as of Gradle 4.0.

sourceSets {
  integrationTest {
    compileClasspath += sourceSets.test.compileClasspath
    runtimeClasspath += sourceSets.test.runtimeClasspath
  }
}

task integrationTest(type: Test) {
  description = "Runs the integration tests."
  group = 'verification'
  testClassesDirs = sourceSets.integrationTest.output.classesDirs
  classpath = sourceSets.integrationTest.runtimeClasspath
}

As of version 4.0, Gradle now uses separate classes directories for each language in a source set. So if your build script uses sourceSets.integrationTest.output.classesDir, you'll see the following deprecation warning.

Gradle now uses separate output directories for each JVM language, but this build assumes a single directory for all classes from a source set. This behaviour has been deprecated and is scheduled to be removed in Gradle 5.0

To get rid of this warning, just switch to sourceSets.integrationTest.output.classesDirs instead. For more information, see the Gradle 4.0 release notes.

Nginx: Job for nginx.service failed because the control process exited

Try to run the following two commands:

sudo fuser -k 80/tcp

sudo fuser -k 443/tcp

Then execute

sudo service nginx restart

If that worked, your hosting provider might be installing Apache on your server by default during a fresh install, so keep reading for a more permenant fix. If that didn't work, keep reading to identify the issue.

Run nginx -t and if it doesn't return anything, I would verify Nginx error log. By default, it should be located in /var/log/nginx/error.log.

You can open it with any text editor: sudo nano /var/log/nginx/error.log

Can you find something suspicious there?

The second log you can check is the following

sudo nano /var/log/syslog

When I had this issue, it was because my hosting provider was automatically installing Apache during a clean install. It was blocking port 80.

When I executed sudo nano /var/log/nginx/error.log I got the following as the error log:

2018/08/04 06:17:33 [emerg] 634#0: bind() to 0.0.0.0:80 failed (98: Address already in use)
2018/08/04 06:17:33 [emerg] 634#0: bind() to [::]:80 failed (98: Address already in use)
2018/08/04 06:17:33 [emerg] 634#0: bind() to 0.0.0.0:80 failed (98: Address already in use)

What the above error is telling is that it was not able to bind nginx to port 80 because it was already in use.

To fix this, you need to run the following:

yum install net-tools

sudo netstat -tulpn

When you execute the above you will get something like the following:

Proto Recv-Q Send-Q Local Address           Foreign Address         State    PID/Program name
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      1762/httpd
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      1224/sshd
tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      1528/sendmail:acce
tcp6       0      0 :::22                   :::*                    LISTEN      1224/sshd

You can see that port 80 is blocked by httpd (Apache). This could also be port 443 if you are using SSL.

Get the PID of the process that uses port 80 or 443. And send the kill command changing the <PID> value:

sudo kill -2 <PID>

Note in my example the PID value of Apache was 1762 so I would execute sudo kill -2 1762

Aternatively you can execute the following:

sudo fuser -k 80/tcp

sudo fuser -k 443/tcp

Now that port 80 or 443 is clear, you can start Nginx by running the following:

sudo service nginx restart

It is also advisable to remove whatever was previously blocking port 80 & 443. This will avoid any conflict in the future. Since Apache (httpd) was blocking my ports I removed it by running the following:

yum remove httpd httpd-devel httpd-manual httpd-tools mod_auth_kerb mod_auth_mysql mod_auth_pgsql mod_authz_ldap mod_dav_svn mod_dnssd mod_nss mod_perl mod_revocator mod_ssl mod_wsgi

Hope this helps.

Regex doesn't work in String.matches()

Used

String[] words = {"{apf","hum_","dkoe","12f"};
    for(String s:words)
    {
        if(s.matches("[a-z]+"))
        {
            System.out.println(s);
        }
    }

Bootstrap 3: Text overlay on image

Is this what you're after?

http://jsfiddle.net/dCNXU/1/

I added :text-align:center to the div and image

JavaScript variable assignments from tuples

I made a tuple implementation that works quite well. This solution allows for array destructuring, as well as basic type-cheking.

const Tuple = (function() {
    function Tuple() {
        // Tuple needs at least one element
        if (arguments.length < 1) {
            throw new Error('Tuple needs at least one element');
        }

        const args = { ...arguments };

        // Define a length property (equal to the number of arguments provided)
        Object.defineProperty(this, 'length', {
            value: arguments.length,
            writable: false
        });

        // Assign values to enumerable properties
        for (let i in args) {
            Object.defineProperty(this, i, {
                enumerable: true,
                get() {
                    return args[+i];
                },
                // Checking if the type of the provided value matches that of the existing value
                set(value) {
                    if (typeof value !== typeof args[+i]) {
                        throw new Error('Cannot assign ' + typeof value + ' on ' + typeof args[+i]);
                    }

                    args[+i] = value;
                }
            });
        }

        // Implementing iteration with Symbol.iterator (allows for array destructuring as well for...of loops)
        this[Symbol.iterator] = function() {
            const tuple = this;

            return {
                current: 0,
                last: tuple.length - 1,
                next() {
                    if (this.current <= this.last) {
                        let val = { done: false, value: tuple[this.current] };
                        this.current++;
                        return val;
                    } else {
                        return { done: true };
                    }
                }
            };
        };

        // Sealing the object to make sure no more values can be added to tuple
        Object.seal(this);
    }

    // check if provided object is a tuple
    Tuple.isTuple = function(obj) {
        return obj instanceof Tuple;
    };

    // Misc. for making the tuple more readable when printing to the console
    Tuple.prototype.toString = function() {
        const copyThis = { ...this };
        const values = Object.values(copyThis);
        return `(${values.join(', ')})`;
    };

    // conctat two instances of Tuple
    Tuple.concat = function(obj1, obj2) {
        if (!Tuple.isTuple(obj1) || !Tuple.isTuple(obj2)) {
            throw new Error('Cannot concat Tuple with ' + typeof (obj1 || obj2));
        }

        const obj1Copy = { ...obj1 };
        const obj2Copy = { ...obj2 };

        const obj1Items = Object.values(obj1Copy);
        const obj2Items = Object.values(obj2Copy);

        return new Tuple(...obj1Items, ...obj2Items);
    };

    return Tuple;
})();

const SNAKE_COLOR = new Tuple(0, 220, 10);

const [red, green, blue] = SNAKE_COLOR;
console.log(green); // => 220


CMD what does /im (taskkill)?

See the doc : it will close all running tasks using the executable file something.exe, more or less like linux' killall

Google Maps API v3 adding an InfoWindow to each marker

Try this:

for (var i in tracks[racer_id].data.points) {
    values = tracks[racer_id].data.points[i];                
    point = new google.maps.LatLng(values.lat, values.lng);
    if (values.qst) {
        var marker = new google.maps.Marker({map: map, position: point, clickable: true});
        tracks[racer_id].markers[i] = marker;
        var info = new google.maps.InfoWindow({
            content: '<b>Speed:</b> ' + values.inst + ' knots'
        });
        tracks[racer_id].info[i] = info;
        google.maps.event.addListener(tracks[racer_id].markers[i], 'click', function() {
            tracks[racer_id].info[i].open(map, tracks[racer_id].markers[i]);
        });
    }
    track_coordinates.push(point);
    bd.extend(point);
}

How can I know if a branch has been already merged into master?

I am using the following bash function like: git-is-merged develop feature/new-feature

git-is-merged () {
  merge_destination_branch=$1
  merge_source_branch=$2

  merge_base=$(git merge-base $merge_destination_branch $merge_source_branch)
  merge_source_current_commit=$(git rev-parse $merge_source_branch)
  if [[ $merge_base = $merge_source_current_commit ]]
  then
    echo $merge_source_branch is merged into $merge_destination_branch
    return 0
  else
    echo $merge_source_branch is not merged into $merge_destination_branch
    return 1
  fi
}

IIS w3svc error

For me the solution was easy, there was no room left on drive C, once deleted some old files i was able to perform IISReset and all the services started successfully.

SQL injection that gets around mysql_real_escape_string()

Well, there's nothing really that can pass through that, other than % wildcard. It could be dangerous if you were using LIKE statement as attacker could put just % as login if you don't filter that out, and would have to just bruteforce a password of any of your users. People often suggest using prepared statements to make it 100% safe, as data can't interfere with the query itself that way. But for such simple queries it probably would be more efficient to do something like $login = preg_replace('/[^a-zA-Z0-9_]/', '', $login);

PHP date time greater than today

You are not comparing dates. You are comparing strings. In the world of string comparisons, 09/17/2015 > 01/02/2016 because 09 > 01. You need to either put your date in a comparable string format or compare DateTime objects which are comparable.

<?php
 $date_now = date("Y-m-d"); // this format is string comparable

if ($date_now > '2016-01-02') {
    echo 'greater than';
}else{
    echo 'Less than';
}

Demo

Or

<?php
 $date_now = new DateTime();
 $date2    = new DateTime("01/02/2016");

if ($date_now > $date2) {
    echo 'greater than';
}else{
    echo 'Less than';
}

Demo

R: Break for loop

Well, your code is not reproducible so we will never know for sure, but this is what help('break')says:

break breaks out of a for, while or repeat loop; control is transferred to the first statement outside the inner-most loop.

So yes, break only breaks the current loop. You can also see it in action with e.g.:

for (i in 1:10)
{
    for (j in 1:10)
    {
        for (k in 1:10)
        {
            cat(i," ",j," ",k,"\n")
            if (k ==5) break
        }   
    }
}

matplotlib: how to change data points color based on some variable

This is what matplotlib.pyplot.scatter is for.

As a quick example:

import matplotlib.pyplot as plt
import numpy as np

# Generate data...
t = np.linspace(0, 2 * np.pi, 20)
x = np.sin(t)
y = np.cos(t)

plt.scatter(t,x,c=y)
plt.show()

enter image description here

Form Submit jQuery does not work

Alright, this doesn't apply to the OP's exact situation, but for anyone like myself who comes here facing a similar issue, figure I should throw this out there-- maybe save a headache or two.

If you're using an non-standard "button" to ensure the submit event isn't called:

<form>
  <input type="hidden" name="hide" value="1">
  <a href="#" onclick="submitWithChecked(this.form)">Hide Selected</a>
 </form>

Then, when you try to access this.form in the script, it's going to come up undefined. As I discovered, apparently anchor elements don't have same access to a parent form element the way your standard form elements do.

In such cases, (again, assuming you are intentionally avoiding the submit event for the time-being), you can use a button with type="button"

<form>
  <input type="hidden" name="hide" value="1">
  <button type="button" onclick="submitWithChecked(this.form)">Hide Selected</a>
 </form>

(Addendum 2020: All these years later, I think the more important lesson to take away from this is to check your input. If my function had bothered to check that the argument it received was actually a form element, the problem would have been much easier to catch.)

Change default timeout for mocha

Adding this for completeness. If you (like me) use a script in your package.json file, just add the --timeout option to mocha:

"scripts": {
  "test": "mocha 'test/**/*.js' --timeout 10000",
  "test-debug": "mocha --debug 'test/**/*.js' --timeout 10000"
},

Then you can run npm run test to run your test suite with the timeout set to 10,000 milliseconds.

How to edit log message already committed in Subversion?

If you are using an IDE like eclipse, you can use this easy way.

Right click on the project -> Team - Show history

In that right click on the revision id for your commit and select 'Set commit properties'.

You can modify the message as you want from here.

How to install a node.js module without using npm?

Download the code from github into the node_modules directory

var moduleName = require("<name of directory>")

that should do it.

if the module has dependancies and has a package.json, open the module and enter npm install.

Hope this helps

How do you redirect to a page using the POST verb?

I would like to expand the answer of Jason Bunting

like this

ActionResult action = new SampelController().Index(2, "text");
return action;

And Eli will be here for something idea on how to make it generic variable

Can get all types of controller

How to use jQuery in AngularJS

You have to do binding in a directive. Look at this:

angular.module('ng', []).
directive('sliderRange', function($parse, $timeout){
    return {
        restrict: 'A',
        replace: true,
        transclude: false,
        compile: function(element, attrs) {            
            var html = '<div class="slider-range"></div>';
            var slider = $(html);
            element.replaceWith(slider);
            var getterLeft = $parse(attrs.ngModelLeft), setterLeft = getterLeft.assign;
            var getterRight = $parse(attrs.ngModelRight), setterRight = getterRight.assign;

            return function (scope, slider, attrs, controller) {
                var vsLeft = getterLeft(scope), vsRight = getterRight(scope), f = vsLeft || 0, t = vsRight || 10;                        

                var processChange = function() {
                    var vs = slider.slider("values"), f = vs[0], t = vs[1];                                        
                    setterLeft(scope, f);
                    setterRight(scope, t);                    
                }                 
                slider.slider({
                    range: true,
                    min: 0,
                    max: 10,
                    step: 1,
                    change: function() { setTimeout(function () { scope.$apply(processChange); }, 1) }
                }).slider("values", [f, t]);                    
            };            
        }
    };
});

This shows you an example of a slider range, done with jQuery UI. Example usage:

<div slider-range ng-model-left="question.properties.range_from" ng-model-right="question.properties.range_to"></div>

jQuery, get html of a whole element

Differences might not be meaningful in a typical use case, but using the standard DOM functionality

$("#el")[0].outerHTML

is about twice as fast as

$("<div />").append($("#el").clone()).html();

so I would go with:

/* 
 * Return outerHTML for the first element in a jQuery object,
 * or an empty string if the jQuery object is empty;  
 */
jQuery.fn.outerHTML = function() {
   return (this[0]) ? this[0].outerHTML : '';  
};

lexical or preprocessor issue file not found occurs while archiving?

In my case I was developing a framework and had a test application inside it, what was missing is inside the test application target -> build settings -> Framework Search Paths:

  • The value needed to be the framework path (the build output - .framework) which is in my case: "../FrameworkNameFolder/" - the 2 points indicates to go one folder up.

Also, inside the test application target -> Build Phases -> Link Binary With Libraries:

  • I had to remove the framework file, clean the project, add the framework file again, compile and this also solved the issue.

How to pass values across the pages in ASP.net without using Session

You can assign it to a hidden field, and retrieve it using

var value= Request.Form["value"]

show distinct column values in pyspark dataframe: python

If you want to select ALL(columns) data as distinct frrom a DataFrame (df), then

df.select('*').distinct().show(10,truncate=False)

set font size in jquery

Not saying this is better, just another way:

$("#elem")[0].style.fontSize="20px";

git rebase merge conflict

When you have a conflict during rebase you have three options:

  • You can run git rebase --abort to completely undo the rebase. Git will return you to your branch's state as it was before git rebase was called.

  • You can run git rebase --skip to completely skip the commit. That means that none of the changes introduced by the problematic commit will be included. It is very rare that you would choose this option.

  • You can fix the conflict as iltempo said. When you're finished, you'll need to call git rebase --continue. My mergetool is kdiff3 but there are many more which you can use to solve conflicts. You only need to set your merge tool in git's settings so it can be invoked when you call git mergetool https://git-scm.com/docs/git-mergetool

If none of the above works for you, then go for a walk and try again :)

What is &amp used for

HTML doesn't recognize the & but it will recognize &amp; because it is equal to & in HTML

I looked over this post someone had made: http://www.webmasterworld.com/forum21/8851.htm

Check if a String is in an ArrayList of Strings

    List list1 = new ArrayList();
    list1.add("one");
    list1.add("three");
    list1.add("four");

    List list2 = new ArrayList();
    list2.add("one");
    list2.add("two");
    list2.add("three");
    list2.add("four");
    list2.add("five");


    list2.stream().filter( x -> !list1.contains(x) ).forEach(x -> System.out.println(x));

The output is:

two
five

How to export JSON from MongoDB using Robomongo

You can use tojson to convert each record to JSON in a MongoDB shell script.

Run this script in RoboMongo:

var cursor = db.getCollection('foo').find({}, {});
while(cursor.hasNext()) {
    print(tojson(cursor.next()))
}

This prints all results as a JSON-like array.

The result is not really JSON! Some types, such as dates and object IDs, are printed as JavaScript function calls, e.g., ISODate("2016-03-03T12:15:49.996Z").

Might not be very efficient for large result sets, but you can limit the query. Alternatively, you can use mongoexport.

For div to extend full height

In case also setting the height of the html and the body to 100% makes everything messier for you as it did for me, the following worked for me:

height: calc(100vh - 33rem)

The - 33rem is the height of the elements coming after the one we want to take full height, i.e., 100vh. By subtracting the height, we will make sure there is no overflow and it will always be responsive (assuming we are working with rem instead of px).

Creating a procedure in mySql with parameters

Its very easy to create procedure in Mysql. Here, in my example I am going to create a procedure which is responsible to fetch all data from student table according to supplied name.

DELIMITER //
CREATE PROCEDURE getStudentInfo(IN s_name VARCHAR(64))
BEGIN
SELECT * FROM student_database.student s where s.sname = s_name;
END//
DELIMITER;

In the above example ,database and table names are student_database and student respectively. Note: Instead of s_name, you can also pass @s_name as global variable.

How to call procedure? Well! its very easy, simply you can call procedure by hitting this command

$mysql> CAll getStudentInfo('pass_required_name');

enter image description here

My docker container has no internet

Just adding this here in case someone runs into this issue within a virtualbox container running docker. I reconfigured the virtualbox network to bridged instead of nat, and the problem went away.

How to "properly" print a list?

If you are using Python3:

print('[',end='');print(*L, sep=', ', end='');print(']')

JavaFX 2.1 TableView refresh items

I know that this question is 4 years old but I have the same problem, I tried the solutions from above and didn't worked. I also called refresh() method but still not my expected result. So I post here my solution maybe will help someone.

Question db = center.getSelectionModel().getSelectedItem();
new QuestionCrud().deleteQ(db.getId());
ObservableList<Question> aftDelete = FXCollections.observableArrayList(
        (new QuestionCrud()).all()
        );
center.setItems(aftDelete);

Even that before of this I used another variable in ObeservableList for setting items into the tableview, I call this a "filthy method" but until I get a better solution is ok.

How do I 'svn add' all unversioned files to SVN?

This is the lazy and dangerous way to synchronize a directory with SVN including new files:

svn rm --keep-local dir
svn add dir

Although this can work in a pinch it can have serious consequences as well. For example, SVN will often lose track of a file's history.

The ideal way to syncronize a directory would be to be able to diff then use svn patch, however this deviates from formats in the diff command and the svn diff command will compare working directory differences rather than differences on the file system level.

Java 8, Streams to find the duplicate elements

You can get the duplicated like this :

List<Integer> numbers = Arrays.asList(1, 2, 1, 3, 4, 4);
Set<Integer> duplicated = numbers
  .stream()
  .filter(n -> numbers
        .stream()
        .filter(x -> x == n)
        .count() > 1)
   .collect(Collectors.toSet());

Installing packages in Sublime Text 2

You may try to install Package Control first by following simple instructions available at Installation Guide (which is like 1. Open the Console, 2. Paste the code).

Then please check Package Docs Control Usage for Basic Functionality:

Package Control is driven by the Command Pallete. To open the pallete, press Ctrl+Shift+P (Win, Linux) or CMD+Shift+P (OS X). All Package Control commands begin with Package Control:, so start by typing Package.

The command pallete will now show a number of commands. Most users will be interested in the following:

Install Package

Show a list of all available packages that are available for install. This will include all of the packages from the default channel, plus any from repositories you have added.

Get the value in an input text box

There is one important thing to mention:

$("#txt_name").val();

will return the current real value of a text field, for example if the user typed something there after a page load.

But:

$("#txt_name").attr('value')

will return value from DOM/HTML.

Angular2 RC6: '<component> is not a known element'

For future problems. If you think you followed all the good answers and yet, the problem is there.

Try turning the server off and on.

I had the same problem, followed all the steps, couldn't solve it. Turn off, on and it was fixed.

How to generate access token using refresh token through google drive API?

Just posting my answer in case it helps anyone as I spent an hour to figure it out :)

First of all two very helpful link related to google api and fetching data from any of google services:

https://developers.google.com/analytics/devguides/config/mgmt/v3/quickstart/web-php

https://developers.google.com/identity/protocols/OAuth2WebServer

Furthermore, when using the following method:

$client->setAccessToken($token)

The $token needs to be the full object returned by the google when making authorization request, not the only access_token which you get inside the object so if you get the object lets say:

{"access_token":"xyz","token_type":"Bearer","expires_in":3600,"refresh_token":"mno","created":1532363626}

then you need to give:

$client->setAccessToken('{"access_token":"xyz","token_type":"Bearer","expires_in":3600,"refresh_token":"mno","created":1532363626}')

Not

$client->setAccessToken('xyz')

And then even if your access_token is expired, google will refresh it itself by using the refresh_token in the access_token object.

Get MD5 hash of big files in Python

You need to read the file in chunks of suitable size:

def md5_for_file(f, block_size=2**20):
    md5 = hashlib.md5()
    while True:
        data = f.read(block_size)
        if not data:
            break
        md5.update(data)
    return md5.digest()

NOTE: Make sure you open your file with the 'rb' to the open - otherwise you will get the wrong result.

So to do the whole lot in one method - use something like:

def generate_file_md5(rootdir, filename, blocksize=2**20):
    m = hashlib.md5()
    with open( os.path.join(rootdir, filename) , "rb" ) as f:
        while True:
            buf = f.read(blocksize)
            if not buf:
                break
            m.update( buf )
    return m.hexdigest()

The update above was based on the comments provided by Frerich Raabe - and I tested this and found it to be correct on my Python 2.7.2 windows installation

I cross-checked the results using the 'jacksum' tool.

jacksum -a md5 <filename>

http://www.jonelo.de/java/jacksum/

Eclipse - debugger doesn't stop at breakpoint

If you are on Eclipse,

Right click on your project folder under "Package Explorer".

Goto Source -> Clean up and choose your project.

This will cleanup any mess and your break-point should work now.

How to implement a material design circular progress bar in android

Was looking for a way to do this using simple xml, but couldn't find any helpful answers, so came up with this.

This works on pre-lollipop versions too, and is pretty close to the material design progress bar. You just need to use this drawable as the indeterminate drawable in the ProgressBar layout.

<?xml version="1.0" encoding="utf-8"?><!--<layer-list>-->
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
    android:fromDegrees="0"
    android:toDegrees="360">
    <layer-list>
        <item>
            <rotate xmlns:android="http://schemas.android.com/apk/res/android"
                android:fromDegrees="-90"
                android:toDegrees="-90">
                <shape
                    android:innerRadiusRatio="2.5"
                    android:shape="ring"
                    android:thickness="2dp"
                    android:useLevel="true"><!-- this line fixes the issue for lollipop api 21 -->

                    <gradient
                        android:angle="0"
                        android:endColor="#007DD6"
                        android:startColor="#007DD6"
                        android:type="sweep"
                        android:useLevel="false" />
                </shape>
            </rotate>
        </item>
        <item>
            <rotate xmlns:android="http://schemas.android.com/apk/res/android"
                android:fromDegrees="0"
                android:toDegrees="270">
                <shape
                    android:innerRadiusRatio="2.6"
                    android:shape="ring"
                    android:thickness="4dp"
                    android:useLevel="true"><!-- this line fixes the issue for lollipop api 21 -->
                    <gradient
                        android:angle="0"
                        android:centerColor="#FFF"
                        android:endColor="#FFF"
                        android:startColor="#FFF"
                        android:useLevel="false" />
                </shape>
            </rotate>
        </item>
    </layer-list>
</rotate>

set the above drawable in ProgressBar as follows:

  android:indeterminatedrawable="@drawable/above_drawable"

How do I convert hh:mm:ss.000 to milliseconds in Excel?

Let's say that your time value is in cell A1 then in A2 you can put:

=A1*1000*60*60*24

or simply:

=A1*86400000

What I am doing is taking the decimal value of the time and multiply it by 1000 (milliseconds) and 60 (seconds) and 60 (minutes) and 24 (hours).

You will then need to format cell A2 as General for it to be in milliseconds format.

If your time is a text value then use:

=TIMEVALUE(A1)*86400000

UPDATE

Per @dandfra's comment this solution may not work in the Italian version of Excel.

How to find char in string and get all the indexes?

As the rule of thumb, NumPy arrays often outperform other solutions while working with POD, Plain Old Data. A string is an example of POD and a character too. To find all the indices of only one char in a string, NumPy ndarrays may be the fastest way:

def find1(str, ch):
  # 0.100 seconds for 1MB str 
  npbuf = np.frombuffer(str, dtype=np.uint8) # Reinterpret str as a char buffer
  return np.where(npbuf == ord(ch))          # Find indices with numpy

def find2(str, ch):
  # 0.920 seconds for 1MB str 
  return [i for i, c in enumerate(str) if c == ch] # Find indices with python

ERROR Error: StaticInjectorError(AppModule)[UserformService -> HttpClient]:

Import this in to app.module.ts

import {HttpClientModule} from '@angular/common/http';

and add this one in imports

HttpClientModule

How to find out client ID of component for ajax update/render? Cannot find component with expression "foo" referenced from "bar"

I know this already has a great answer by BalusC but here is a little trick I use to get the container to tell me the correct clientId.

  1. Remove the update on your component that is not working
  2. Put a temporary component with a bogus update within the component you were trying to update
  3. hit the page, the servlet exception error will tell you the correct client Id you need to reference.
  4. Remove bogus component and put correct clientId in the original update

Here is code example as my words may not describe it best.

<p:tabView id="tabs">
    <p:tab id="search" title="Search">                        
        <h:form id="insTable">
            <p:dataTable id="table" var="lndInstrument" value="#{instrumentBean.instruments}">
                <p:column>
                    <p:commandLink id="select"

Remove the failing update within this component

 oncomplete="dlg.show()">
                        <f:setPropertyActionListener value="#{lndInstrument}" 
                                        target="#{instrumentBean.selectedInstrument}" />
                        <h:outputText value="#{lndInstrument.name}" />
                    </p:commandLink>                                    
                </p:column>
            </p:dataTable>
            <p:dialog id="dlg" modal="true" widgetVar="dlg">
                <h:panelGrid id="display">

Add a component within the component of the id you are trying to update using an update that will fail

   <p:commandButton id="BogusButton" update="BogusUpdate"></p:commandButton>

                    <h:outputText value="Name:" />
                    <h:outputText value="#{instrumentBean.selectedInstrument.name}" />
                </h:panelGrid>
            </p:dialog>                            
        </h:form>
    </p:tab>
</p:tabView>

Hit this page and view the error. The error is: javax.servlet.ServletException: Cannot find component for expression "BogusUpdate" referenced from tabs:insTable: BogusButton

So the correct clientId to use would then be the bold plus the id of the target container (display in this case)

tabs:insTable:display

Radio button validation in javascript

Full validation example with javascript:

<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>Radio button: full validation example with javascript</title>
        <script>
            function send() {
                var genders = document.getElementsByName("gender");
                if (genders[0].checked == true) {
                    alert("Your gender is male");
                } else if (genders[1].checked == true) {
                    alert("Your gender is female");
                } else {
                    // no checked
                    var msg = '<span style="color:red;">You must select your gender!</span><br /><br />';
                    document.getElementById('msg').innerHTML = msg;
                    return false;
                }
                return true;
            }

            function reset_msg() {
                document.getElementById('msg').innerHTML = '';
            }
        </script>
    </head>
    <body>
        <form action="" method="POST">
            <label>Gender:</label>
            <br />
            <input type="radio" name="gender" value="m" onclick="reset_msg();" />Male
            <br />
            <input type="radio" name="gender" value="f" onclick="reset_msg();" />Female
            <br />
            <div id="msg"></div>
            <input type="submit" value="send>>" onclick="return send();" />
        </form>
    </body>
</html>

Regards,

Fernando

Best way of invoking getter by reflection

You can invoke reflections and also, set order of sequence for getter for values through annotations

public class Student {

    private String grade;

    private String name;

    private String id;

    private String gender;

    private Method[] methods;

    @Retention(RetentionPolicy.RUNTIME)
    public @interface Order {
        int value();
    }

    /**
     * Sort methods as per Order Annotations
     * 
     * @return
     */
    private void sortMethods() {

        methods = Student.class.getMethods();

        Arrays.sort(methods, new Comparator<Method>() {
            public int compare(Method o1, Method o2) {
                Order or1 = o1.getAnnotation(Order.class);
                Order or2 = o2.getAnnotation(Order.class);
                if (or1 != null && or2 != null) {
                    return or1.value() - or2.value();
                }
                else if (or1 != null && or2 == null) {
                    return -1;
                }
                else if (or1 == null && or2 != null) {
                    return 1;
                }
                return o1.getName().compareTo(o2.getName());
            }
        });
    }

    /**
     * Read Elements
     * 
     * @return
     */
    public void readElements() {
        int pos = 0;
        /**
         * Sort Methods
         */
        if (methods == null) {
            sortMethods();
        }
        for (Method method : methods) {
            String name = method.getName();
            if (name.startsWith("get") && !name.equalsIgnoreCase("getClass")) {
                pos++;
                String value = "";
                try {
                    value = (String) method.invoke(this);
                }
                catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
                    e.printStackTrace();
                }
                System.out.println(name + " Pos: " + pos + " Value: " + value);
            }
        }
    }

    // /////////////////////// Getter and Setter Methods

    /**
     * @param grade
     * @param name
     * @param id
     * @param gender
     */
    public Student(String grade, String name, String id, String gender) {
        super();
        this.grade = grade;
        this.name = name;
        this.id = id;
        this.gender = gender;
    }

    /**
     * @return the grade
     */
    @Order(value = 4)
    public String getGrade() {
        return grade;
    }

    /**
     * @param grade the grade to set
     */
    public void setGrade(String grade) {
        this.grade = grade;
    }

    /**
     * @return the name
     */
    @Order(value = 2)
    public String getName() {
        return name;
    }

    /**
     * @param name the name to set
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * @return the id
     */
    @Order(value = 1)
    public String getId() {
        return id;
    }

    /**
     * @param id the id to set
     */
    public void setId(String id) {
        this.id = id;
    }

    /**
     * @return the gender
     */
    @Order(value = 3)
    public String getGender() {
        return gender;
    }

    /**
     * @param gender the gender to set
     */
    public void setGender(String gender) {
        this.gender = gender;
    }

    /**
     * Main
     * 
     * @param args
     * @throws IOException
     * @throws SQLException
     * @throws InvocationTargetException
     * @throws IllegalArgumentException
     * @throws IllegalAccessException
     */
    public static void main(String args[]) throws IOException, SQLException, IllegalAccessException,
            IllegalArgumentException, InvocationTargetException {
        Student student = new Student("A", "Anand", "001", "Male");
        student.readElements();
    }
  }

Output when sorted

getId Pos: 1 Value: 001
getName Pos: 2 Value: Anand
getGender Pos: 3 Value: Male
getGrade Pos: 4 Value: A

Parse String to Date with Different Format in Java

While SimpleDateFormat will indeed work for your needs, additionally you might want to check out Joda Time, which is apparently the basis for the redone Date library in Java 7. While I haven't used it a lot, I've heard nothing but good things about it and if your manipulating dates extensively in your projects it would probably be worth looking into.

How to read json file into java with simple JSON library

Solution using Jackson library. Sorted this problem by verifying the json on JSONLint.com and then using Jackson. Below is the code for the same.

 Main Class:-

String jsonStr = "[{\r\n" + "       \"name\": \"John\",\r\n" + "        \"city\": \"Berlin\",\r\n"
                + "         \"cars\": [\r\n" + "            \"FIAT\",\r\n" + "          \"Toyata\"\r\n"
                + "     ],\r\n" + "     \"job\": \"Teacher\"\r\n" + "   },\r\n" + " {\r\n"
                + "     \"name\": \"Mark\",\r\n" + "        \"city\": \"Oslo\",\r\n" + "        \"cars\": [\r\n"
                + "         \"VW\",\r\n" + "            \"Toyata\"\r\n" + "     ],\r\n"
                + "     \"job\": \"Doctor\"\r\n" + "    }\r\n" + "]";

        ObjectMapper mapper = new ObjectMapper();

        MyPojo jsonObj[] = mapper.readValue(jsonStr, MyPojo[].class);

        for (MyPojo itr : jsonObj) {

            System.out.println("Val of getName is: " + itr.getName());
            System.out.println("Val of getCity is: " + itr.getCity());
            System.out.println("Val of getJob is: " + itr.getJob());
            System.out.println("Val of getCars is: " + itr.getCars() + "\n");

        }

POJO:

public class MyPojo {

private List<String> cars = new ArrayList<String>();

private String name;

private String job;

private String city;

public List<String> getCars() {
    return cars;
}

public void setCars(List<String> cars) {
    this.cars = cars;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getJob() {
    return job;
}

public void setJob(String job) {
    this.job = job;
}

public String getCity() {
    return city;
}

public void setCity(String city) {
    this.city = city;
} }

  RESULT:-
         Val of getName is: John
         Val of getCity is: Berlin
         Val of getJob is: Teacher
         Val of getCars is: [FIAT, Toyata]

          Val of getName is: Mark
          Val of getCity is: Oslo
          Val of getJob is: Doctor
          Val of getCars is: [VW, Toyata]

"Uncaught (in promise) undefined" error when using with=location in Facebook Graph API query

The error tells you that there is an error but you don´t catch it. This is how you can catch it:

getAllPosts().then(response => {
    console.log(response);
}).catch(e => {
    console.log(e);
});

You can also just put a console.log(reponse) at the beginning of your API callback function, there is definitely an error message from the Graph API in it.

More information: https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Global_Objects/Promise/catch

Or with async/await:

//some async function
try {
    let response = await getAllPosts();
} catch(e) {
    console.log(e);
}

Best way to implement keyboard shortcuts in a Windows Forms application?

From the main Form, you have to:

  • Be sure you set KeyPreview to true( TRUE by default)
  • Add MainForm_KeyDown(..) - by which you can set here any shortcuts you want.

Additionally,I have found this on google and I wanted to share this to those who are still searching for answers. (for global)

I think you have to be using user32.dll

protected override void WndProc(ref Message m)
{
    base.WndProc(ref m);

    if (m.Msg == 0x0312)
    {
        /* Note that the three lines below are not needed if you only want to register one hotkey.
         * The below lines are useful in case you want to register multiple keys, which you can use a switch with the id as argument, or if you want to know which key/modifier was pressed for some particular reason. */

        Keys key = (Keys)(((int)m.LParam >> 16) & 0xFFFF);                  // The key of the hotkey that was pressed.
        KeyModifier modifier = (KeyModifier)((int)m.LParam & 0xFFFF);       // The modifier of the hotkey that was pressed.
        int id = m.WParam.ToInt32();                                        // The id of the hotkey that was pressed.


        MessageBox.Show("Hotkey has been pressed!");
        // do something
    }
}

Further read this http://www.fluxbytes.com/csharp/how-to-register-a-global-hotkey-for-your-application-in-c/

Difference between adjustResize and adjustPan in android?

adjustResize = resize the page content

adjustPan = move page content without resizing page content

How to get .pem file from .key and .crt files?

I needed to do this for an AWS ELB. After getting beaten up by the dialog many times, finally this is what worked for me:

openssl rsa -in server.key -text > private.pem
openssl x509 -inform PEM -in server.crt > public.pem

Thanks NCZ

Edit: As @floatingrock says

With AWS, don't forget to prepend the filename with file://. So it'll look like:

 aws iam upload-server-certificate --server-certificate-name blah --certificate-body file://path/to/server.crt --private-key file://path/to/private.key --path /cloudfront/static/

http://docs.aws.amazon.com/cli/latest/reference/iam/upload-server-certificate.html

Display JSON as HTML

Here's a light-weight solution, doing only what OP asked, including highlighting but nothing else: How can I pretty-print JSON using JavaScript?

How to assign Php variable value to Javascript variable?

Put quotes around the <?php echo $cname; ?> to make sure Javascript accepts it as a string, also consider escaping.

Get controller and action name from within controller?

string actionName = this.ControllerContext.RouteData.Values["action"].ToString();
string controllerName = this.ControllerContext.RouteData.Values["controller"].ToString();

How do I put double quotes in a string in vba?

All double quotes inside double quotes which suround the string must be changed doubled. As example I had one of json file strings : "delivery": "Standard", In Vba Editor I changed it into """delivery"": ""Standard""," and everythig works correctly. If you have to insert a lot of similar strings, my proposal first, insert them all between "" , then with VBA editor replace " inside into "". If you will do mistake, VBA editor shows this line in red and you will correct this error.

How to find the most recent file in a directory using .NET, and without looping?

private List<FileInfo> GetLastUpdatedFileInDirectory(DirectoryInfo directoryInfo)
{
    FileInfo[] files = directoryInfo.GetFiles();
    List<FileInfo> lastUpdatedFile = null;
    DateTime lastUpdate = new DateTime(1, 0, 0);
    foreach (FileInfo file in files)
    {
        if (file.LastAccessTime > lastUpdate)
        {
            lastUpdatedFile.Add(file);
            lastUpdate = file.LastAccessTime;
        }
    }

    return lastUpdatedFile;
}

How to view the current heap size that an application is using?

Use this code:

// Get current size of heap in bytes
long heapSize = Runtime.getRuntime().totalMemory(); 

// Get maximum size of heap in bytes. The heap cannot grow beyond this size.// Any attempt will result in an OutOfMemoryException.
long heapMaxSize = Runtime.getRuntime().maxMemory();

 // Get amount of free memory within the heap in bytes. This size will increase // after garbage collection and decrease as new objects are created.
long heapFreeSize = Runtime.getRuntime().freeMemory(); 

It was useful to me to know it.

iOS: Convert UTC NSDate to local Timezone

I write this Method to convert date time to our LocalTimeZone

-Here (NSString *)TimeZone parameter is a server timezone

-(NSString *)convertTimeIntoLocal:(NSString *)defaultTime :(NSString *)TimeZone
{
    NSDateFormatter *serverFormatter = [[NSDateFormatter alloc] init];
    [serverFormatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:TimeZone]];
    [serverFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSDate *theDate = [serverFormatter dateFromString:defaultTime];
    NSDateFormatter *userFormatter = [[NSDateFormatter alloc] init];
    [userFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    [userFormatter setTimeZone:[NSTimeZone localTimeZone]];
    NSString *dateConverted = [userFormatter stringFromDate:theDate];
    return dateConverted;
}

What does upstream mean in nginx?

If we have a single server we can directly include it in the proxy_pass. But in case if we have many servers we use upstream to maintain the servers. Nginx will load-balance based on the incoming traffic.

How to submit form on change of dropdown list?

Simple JavaScript will do -

<form action="myservlet.do" method="POST">
    <select name="myselect" id="myselect" onchange="this.form.submit()">
        <option value="1">One</option>
        <option value="2">Two</option>
        <option value="3">Three</option>
        <option value="4">Four</option>
    </select>
</form>

Here is a link for a good javascript tutorial.

Open a webpage in the default browser

As others have indicated, Process.Start() is the way to go here. However, there are a few quirks. It's worth your time to read this blog post:

http://faithlife.codes/blog/2008/01/using_processstart_to_link_to/

In summary, some browsers cause it to throw an exception for no good reason, the function can block for a while on non-UI thread so you need to make sure it happens near the end of whatever other actions you might perform at the same time, and you might want to change the cursor appearance while waiting for the browser to open.

Can't install any package with node npm

This means the npm command is getting an HTML document instead of whatever format it is looking for. In my case, I was using sinopia. When I no longer wanted to use it, I accidentally used this command to reset the registry:

npm config set registry https://www.npmjs.com/

which was wrong, and it should have been the command already mentioned here. Read this if none of the answers solve this problem, and you can probably figure out where the incorrect URL is present and clear it off, and set the registry to the correct URL:

npm config set registry https://registry.npmjs.org

React.js: How to append a component on click?

As @Alex McMillan mentioned, use state to dictate what should be rendered in the dom.

In the example below I have an input field and I want to add a second one when the user clicks the button, the onClick event handler calls handleAddSecondInput( ) which changes inputLinkClicked to true. I am using a ternary operator to check for the truthy state, which renders the second input field

class HealthConditions extends React.Component {
  constructor(props) {
    super(props);


    this.state = {
      inputLinkClicked: false
    }
  }

  handleAddSecondInput() {
    this.setState({
      inputLinkClicked: true
    })
  }


  render() {
    return(
      <main id="wrapper" className="" data-reset-cookie-tab>
        <div id="content" role="main">
          <div className="inner-block">

            <H1Heading title="Tell us about any disabilities, illnesses or ongoing conditions"/>

            <InputField label="Name of condition"
              InputType="text"
              InputId="id-condition"
              InputName="condition"
            />

            {
              this.state.inputLinkClicked?

              <InputField label=""
                InputType="text"
                InputId="id-condition2"
                InputName="condition2"
              />

              :

              <div></div>
            }

            <button
              type="button"
              className="make-button-link"
              data-add-button=""
              href="#"
              onClick={this.handleAddSecondInput}
            >
              Add a condition
            </button>

            <FormButton buttonLabel="Next"
              handleSubmit={this.handleSubmit}
              linkto={
                this.state.illnessOrDisability === 'true' ?
                "/404"
                :
                "/add-your-details"
              }
            />

            <BackLink backLink="/add-your-details" />

          </div>
         </div>
      </main>
    );
  }
}

Could not load type 'System.ServiceModel.Activation.HttpModule' from assembly 'System.ServiceModel

I got this error after I accidentally published one website into the directory of another website. The two websites had different versions of .net. What fixed it for me was changing the application pool. To do that, in the IIS manager:

click the website => Advanced Settings... (on the right) => click to the right of Application Pool => a button with "..." should appear => select ".NET v4.5 Classic"

If that application pool doesn't work, try some of the others.

How to make a DIV not wrap?

None of the above worked for me.

In my case, I needed to add the following to the user control I had created:

display:inline-block;

send mail from linux terminal in one line

Sending Simple Mail:

$ mail -s "test message from centos" [email protected]
hello from centos linux command line

Ctrl+D to finish

How to calculate the intersection of two sets?

Yes there is retainAll check out this

Set<Type> intersection = new HashSet<Type>(s1);
intersection.retainAll(s2);

Is it possible to create a temporary table in a View and drop it after select?

No, a view consists of a single SELECT statement. You cannot create or drop tables in a view.

Maybe a common table expression (CTE) can solve your problem. CTEs are temporary result sets that are defined within the execution scope of a single statement and they can be used in views.

Example (taken from here) - you can think of the SalesBySalesPerson CTE as a temporary table:

CREATE VIEW vSalesStaffQuickStats
AS
  WITH SalesBySalesPerson (SalesPersonID, NumberOfOrders, MostRecentOrderDate)
      AS
      (
            SELECT SalesPersonID, COUNT(*), MAX(OrderDate)
            FROM Sales.SalesOrderHeader
            GROUP BY SalesPersonID
      )
  SELECT E.EmployeeID,
         EmployeeOrders = OS.NumberOfOrders,
         EmployeeLastOrderDate = OS.MostRecentOrderDate,
         E.ManagerID,
         ManagerOrders = OM.NumberOfOrders,
         ManagerLastOrderDate = OM.MostRecentOrderDate
  FROM HumanResources.Employee AS E
  INNER JOIN SalesBySalesPerson AS OS ON E.EmployeeID = OS.SalesPersonID
  LEFT JOIN SalesBySalesPerson AS OM ON E.ManagerID = OM.SalesPersonID
GO

Performance considerations

Which are more performant, CTE or temporary tables?

how to align img inside the div to the right?

vertical-align:middle; text-align:right;

Oracle ORA-12154: TNS: Could not resolve service name Error?

I just spend an hour on this, I'm new to Oracle so i was thoroughly confused..

the situation:

just installed visual studio 2012 Oracle developer tools. When i did this I lost the items in my drop down which contained my TNS entries in TOAD. I was getting this error from Visual studio AND TOAD!! WTH! so i added the environmental Variable TNS_ADMIN under "ALL USERS" with the path to my .ora file (which i now worked fine because it worked until I broke it). Toad picked up that change. Still Visual Studio wouldn't give me any love... still getting same error. THEN, i added the environmental Variable TO MY USER VARIABLES.. VIOLA!!

ENSURE THE ENVIRONMENTAL VARIABLES ARE SET FOR THE SYSTEM AND THE USER

How to resolve the error on 'react-native start'

All mentioned comments above are great, sharing the path that worked with me for this Blacklist file that need to be edited:

"Your project name\node_modules\metro-bundler\src" File name "blacklist.js"

Check if a div does NOT exist with javascript

I do below and check if id exist and execute function if exist.

var divIDVar = $('#divID').length;
if (divIDVar === 0){ 
    console.log('No DIV Exist'); 
} else{  
    FNCsomefunction(); 
}   

Simple C example of doing an HTTP POST and consuming the response

After weeks of research. I came up with the following code. I believe this is the bare minimum needed to make a secure connection with SSL to a web server.

#include <stdio.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/bio.h>

#define APIKEY "YOUR_API_KEY"
#define HOST "YOUR_WEB_SERVER_URI"
#define PORT "443"

int main() {

    //
    //  Initialize the variables
    //
    BIO* bio;
    SSL* ssl;
    SSL_CTX* ctx;

    //
    //   Registers the SSL/TLS ciphers and digests.
    //
    //   Basically start the security layer.
    //
    SSL_library_init();

    //
    //  Creates a new SSL_CTX object as a framework to establish TLS/SSL
    //  or DTLS enabled connections
    //
    ctx = SSL_CTX_new(SSLv23_client_method());

    //
    //  -> Error check
    //
    if (ctx == NULL)
    {
        printf("Ctx is null\n");
    }

    //
    //   Creates a new BIO chain consisting of an SSL BIO
    //
    bio = BIO_new_ssl_connect(ctx);

    //
    //  Use the variable from the beginning of the file to create a 
    //  string that contains the URL to the site that you want to connect
    //  to while also specifying the port.
    //
    BIO_set_conn_hostname(bio, HOST ":" PORT);

    //
    //   Attempts to connect the supplied BIO
    //
    if(BIO_do_connect(bio) <= 0)
    {
        printf("Failed connection\n");
        return 1;
    }
    else
    {
        printf("Connected\n");
    }

    //
    //  The bare minimum to make a HTTP request.
    //
    char* write_buf = "POST / HTTP/1.1\r\n"
                      "Host: " HOST "\r\n"
                      "Authorization: Basic " APIKEY "\r\n"
                      "Connection: close\r\n"
                      "\r\n";

    //
    //   Attempts to write len bytes from buf to BIO
    //
    if(BIO_write(bio, write_buf, strlen(write_buf)) <= 0)
    {
        //
        //  Handle failed writes here
        //
        if(!BIO_should_retry(bio))
        {
            // Not worth implementing, but worth knowing.
        }

        //
        //  -> Let us know about the failed writes
        //
        printf("Failed write\n");
    }

    //
    //  Variables used to read the response from the server
    //
    int size;
    char buf[1024];

    //
    //  Read the response message
    //
    for(;;)
    {
        //
        //  Get chunks of the response 1023 at the time.
        //
        size = BIO_read(bio, buf, 1023);

        //
        //  If no more data, then exit the loop
        //
        if(size <= 0)
        {
            break;
        }

        //
        //  Terminate the string with a 0, to let know C when the string 
        //  ends.
        //
        buf[size] = 0;

        //
        //  ->  Print out the response
        //
        printf("%s", buf);
    }

    //
    //  Clean after ourselves
    //
    BIO_free_all(bio);
    SSL_CTX_free(ctx);

    return 0;
}

The code above will explain in details how to establish a TLS connection with a remote server.

Important note: this code doesn't check if the public key was signed by a valid authority. Meaning I don't use root certificates for validation. Don't forget to implement this check otherwise you won't know if you are connecting the right website

When it comes to the request itself. It is nothing more then writing the HTTP request by hand.

You can also find under this link an explanation how to instal openSSL in your system, and how to compile the code so it uses the secure library.

jQuery creating objects

May be you want this (oop in javascript)

function box(color)
{
    this.color=color;
}

var box1=new box('red');    
var box2=new box('white');    

DEMO.

For more information.

Convert line endings

Doing this with POSIX is tricky:

  • POSIX Sed does not support \r or \15. Even if it did, the in place option -i is not POSIX

  • POSIX Awk does support \r and \15, however the -i inplace option is not POSIX

  • d2u and dos2unix are not POSIX utilities, but ex is

  • POSIX ex does not support \r, \15, \n or \12

To remove carriage returns:

awk 'BEGIN{RS="^$";ORS="";getline;gsub("\r","");print>ARGV[1]}' file

To add carriage returns:

awk 'BEGIN{RS="^$";ORS="";getline;gsub("\n","\r&");print>ARGV[1]}' file

Debugging WebSocket in Google Chrome

I'm just posting this since Chrome changes alot, and none of the answers were quite up to date.

  1. Open dev tools
  2. REFRESH YOUR PAGE (so that the WS connection is captured by the network tab)
  3. Click your request
  4. Click the "Frames" sub-tab
  5. You should see somthing like this:

enter image description here

Bootstrap 4 align navbar items to the right

Use ml-auto instead of mr-auto after applying nav justify-content-end to the ul

jquery - is not a function error

This problem is "best" solved by using an anonymous function to pass-in the jQuery object thusly:

The Anonymous Function Looks Like:

<script type="text/javascript">
    (function($) {
        // You pass-in jQuery and then alias it with the $-sign
        // So your internal code doesn't change
    })(jQuery);
</script>

This is JavaScript's method of implementing (poor man's) 'Dependency Injection' when used alongside things like the 'Module Pattern'.

So Your Code Would Look Like:
Of course, you might want to make some changes to your internal code now, but you get the idea.

<script type="text/javascript">
    (function($) {
        $.fn.pluginbutton = function(options) {
            myoptions = $.extend({ left: true });
            return this.each(function() {
                var focus = false;
                if (focus === false) {
                    this.hover(function() {
                        this.animate({ backgroundPosition: "0 -30px" }, { duration: 0 });
                        this.removeClass('VBfocus').addClass('VBHover');
                    }, function() {
                        this.animate({ backgroundPosition: "0 0" }, { duration: 0 });
                        this.removeClass('VBfocus').removeClass('VBHover');
                    });
                }
                this.mousedown(function() {
                    focus = true
                    this.animate({ backgroundPosition: "0 30px" }, { duration: 0 });
                    this.addClass('VBfocus').removeClass('VBHover');
                }, function() {
                    focus = false;
                    this.animate({ backgroundPosition: "0 0" }, { duration: 0 });
                    this.removeClass('VBfocus').addClass('VBHover');
                });
            });
        }
    })(jQuery);
</script>

How to get a vCard (.vcf file) into Android contacts from website

I had problems with importing a VERSION:4.0 vcard file on Android 7 (LineageOS) with the standard Contacts app.

Since this is on the top search hits for "android vcard format not supported", I just wanted to note that I was able to import them with the Simple Contacts app (Play or F-Droid).

What is the use of a cursor in SQL Server?

Cursor itself is an iterator (like WHILE). By saying iterator I mean a way to traverse the record set (aka a set of selected data rows) and do operations on it while traversing. Operations could be INSERT or DELETE for example. Hence you can use it for data retrieval for example. Cursor works with the rows of the result set sequentially - row by row. A cursor can be viewed as a pointer to one row in a set of rows and can only reference one row at a time, but can move to other rows of the result set as needed.

This link can has a clear explanation of its syntax and contains additional information plus examples.

Cursors can be used in Sprocs too. They are a shortcut that allow you to use one query to do a task instead of several queries. However, cursors recognize scope and are considered undefined out of the scope of the sproc and their operations execute within a single procedure. A stored procedure cannot open, fetch, or close a cursor that was not declared in the procedure.

SQL Server - Convert date field to UTC

If they're all local to you, then here's the offset:

SELECT GETDATE() AS CurrentTime, GETUTCDATE() AS UTCTime

and you should be able to update all the data using:

UPDATE SomeTable
   SET DateTimeStamp = DATEADD(hh, DATEDIFF(hh, GETDATE(), GETUTCDATE()), DateTimeStamp)

Would that work, or am I missing another angle of this problem?

Convert a Unicode string to an escaped ASCII string

You need to use the Convert() method in the Encoding class:

  • Create an Encoding object that represents ASCII encoding
  • Create an Encoding object that represents Unicode encoding
  • Call Encoding.Convert() with the source encoding, the destination encoding, and the string to be encoded

There is an example here:

using System;
using System.Text;

namespace ConvertExample
{
   class ConvertExampleClass
   {
      static void Main()
      {
         string unicodeString = "This string contains the unicode character Pi(\u03a0)";

         // Create two different encodings.
         Encoding ascii = Encoding.ASCII;
         Encoding unicode = Encoding.Unicode;

         // Convert the string into a byte[].
         byte[] unicodeBytes = unicode.GetBytes(unicodeString);

         // Perform the conversion from one encoding to the other.
         byte[] asciiBytes = Encoding.Convert(unicode, ascii, unicodeBytes);

         // Convert the new byte[] into a char[] and then into a string.
         // This is a slightly different approach to converting to illustrate
         // the use of GetCharCount/GetChars.
         char[] asciiChars = new char[ascii.GetCharCount(asciiBytes, 0, asciiBytes.Length)];
         ascii.GetChars(asciiBytes, 0, asciiBytes.Length, asciiChars, 0);
         string asciiString = new string(asciiChars);

         // Display the strings created before and after the conversion.
         Console.WriteLine("Original string: {0}", unicodeString);
         Console.WriteLine("Ascii converted string: {0}", asciiString);
      }
   }
}

How to make war file in Eclipse

File -> Export -> Web -> WAR file

OR in Kepler follow as shown below :

enter image description here

Explain ExtJS 4 event handling

Let's start by describing DOM elements' event handling.

DOM node event handling

First of all you wouldn't want to work with DOM node directly. Instead you probably would want to utilize Ext.Element interface. For the purpose of assigning event handlers, Element.addListener and Element.on (these are equivalent) were created. So, for example, if we have html:

<div id="test_node"></div>

and we want add click event handler.
Let's retrieve Element:

var el = Ext.get('test_node');

Now let's check docs for click event. It's handler may have three parameters:

click( Ext.EventObject e, HTMLElement t, Object eOpts )

Knowing all this stuff we can assign handler:

//       event name      event handler
el.on(    'click'        , function(e, t, eOpts){
  // handling event here
});

Widgets event handling

Widgets event handling is pretty much similar to DOM nodes event handling.

First of all, widgets event handling is realized by utilizing Ext.util.Observable mixin. In order to handle events properly your widget must containg Ext.util.Observable as a mixin. All built-in widgets (like Panel, Form, Tree, Grid, ...) has Ext.util.Observable as a mixin by default.

For widgets there are two ways of assigning handlers. The first one - is to use on method (or addListener). Let's for example create Button widget and assign click event to it. First of all you should check event's docs for handler's arguments:

click( Ext.button.Button this, Event e, Object eOpts )

Now let's use on:

var myButton = Ext.create('Ext.button.Button', {
  text: 'Test button'
});
myButton.on('click', function(btn, e, eOpts) {
  // event handling here
  console.log(btn, e, eOpts);
});

The second way is to use widget's listeners config:

var myButton = Ext.create('Ext.button.Button', {
  text: 'Test button',
  listeners : {
    click: function(btn, e, eOpts) {
      // event handling here
      console.log(btn, e, eOpts);
    }
  }
});

Notice that Button widget is a special kind of widgets. Click event can be assigned to this widget by using handler config:

var myButton = Ext.create('Ext.button.Button', {
  text: 'Test button',
  handler : function(btn, e, eOpts) {
    // event handling here
    console.log(btn, e, eOpts);
  }
});

Custom events firing

First of all you need to register an event using addEvents method:

myButton.addEvents('myspecialevent1', 'myspecialevent2', 'myspecialevent3', /* ... */);

Using the addEvents method is optional. As comments to this method say there is no need to use this method but it provides place for events documentation.

To fire your event use fireEvent method:

myButton.fireEvent('myspecialevent1', arg1, arg2, arg3, /* ... */);

arg1, arg2, arg3, /* ... */ will be passed into handler. Now we can handle your event:

myButton.on('myspecialevent1', function(arg1, arg2, arg3, /* ... */) {
  // event handling here
  console.log(arg1, arg2, arg3, /* ... */);
});

It's worth mentioning that the best place for inserting addEvents method call is widget's initComponent method when you are defining new widget:

Ext.define('MyCustomButton', {
  extend: 'Ext.button.Button',
  // ... other configs,
  initComponent: function(){
    this.addEvents('myspecialevent1', 'myspecialevent2', 'myspecialevent3', /* ... */);
    // ...
    this.callParent(arguments);
  }
});
var myButton = Ext.create('MyCustomButton', { /* configs */ });

Preventing event bubbling

To prevent bubbling you can return false or use Ext.EventObject.preventDefault(). In order to prevent browser's default action use Ext.EventObject.stopPropagation().

For example let's assign click event handler to our button. And if not left button was clicked prevent default browser action:

myButton.on('click', function(btn, e){
  if (e.button !== 0)
    e.preventDefault();
});

How to initialize a dict with keys from a list and empty value in Python?

You could use dict.fromkeys as follows:

dict.fromkeys([1, 2, 3, 4], list())

This will create a list object for each key. If you change value for any specific key it won't affect other keys (as most people would want, I presume).

Sending intent to BroadcastReceiver from adb

Noting down my situation here may be useful to somebody,

I have to send a custom intent with multiple intent extras to a broadcast receiver in Android P,

The details are,

Receiver name: com.hardian.testservice.TestBroadcastReceiver

Intent action = "com.hardian.testservice.ADD_DATA"

intent extras are,

  1. "text"="test msg",
  2. "source"= 1,

Run the following in command line.

adb shell "am broadcast -a com.hardian.testservice.ADD_DATA --es text 'test msg' --es source 1 -n com.hardian.testservice/.TestBroadcastReceiver"

Hope this helps.

Delete forked repo from GitHub

Deleting it will do nothing to the original project. Editing it will only edit your fork on your repo page.

UTF-8, UTF-16, and UTF-32

I tried to give a simple explanation in my blogpost.

UTF-32

requires 32 bits (4 bytes) to encode any character. For example, in order to represent the "A" character code-point using this scheme, you'll need to write 65 in 32-bit binary number:

00000000 00000000 00000000 01000001 (Big Endian)

If you take a closer look, you'll note that the most-right seven bits are actually the same bits when using the ASCII scheme. But since UTF-32 is fixed width scheme, we must attach three additional bytes. Meaning that if we have two files that only contain the "A" character, one is ASCII-encoded and the other is UTF-32 encoded, their size will be 1 byte and 4 bytes correspondingly.

UTF-16

Many people think that as UTF-32 uses fixed width 32 bit to represent a code-point, UTF-16 is fixed width 16 bits. WRONG!

In UTF-16 the code point maybe represented either in 16 bits, OR 32 bits. So this scheme is variable length encoding system. What is the advantage over the UTF-32? At least for ASCII, the size of files won't be 4 times the original (but still twice), so we're still not ASCII backward compatible.

Since 7-bits are enough to represent the "A" character, we can now use 2 bytes instead of 4 like the UTF-32. It'll look like:

00000000 01000001

UTF-8

You guessed right.. In UTF-8 the code point maybe represented using either 32, 16, 24 or 8 bits, and as the UTF-16 system, this one is also variable length encoding system.

Finally we can represent "A" in the same way we represent it using ASCII encoding system:

01001101

A small example where UTF-16 is actually better than UTF-8:

Consider the Chinese letter "?" - its UTF-8 encoding is:

11101000 10101010 10011110

While its UTF-16 encoding is shorter:

10001010 10011110

In order to understand the representation and how it's interpreted, visit the original post.

Google Chrome display JSON AJAX response as tree and not as a plain text

There was an issue with a build of Google Chrome Dev build 24.0.1312.5 that caused the preview panel to no longer display a json object tree but rather flat text. It should be fixed in the next dev

See more here: http://code.google.com/p/chromium/issues/detail?id=160733

Can Keras with Tensorflow backend be forced to use CPU or GPU at will?

This worked for me (win10), place before you import keras:

import os
os.environ['CUDA_VISIBLE_DEVICES'] = '-1'

Find a string by searching all tables in SQL Server Management Studio 2008

Improving the amazing answer from @Brandon, I added type to ntext and xml using castings:

BEGIN TRAN

DECLARE @SearchStr nvarchar(100) = 'SEARCH_TEXT'
DECLARE @Results TABLE (ColumnName nvarchar(370), ColumnValue nvarchar(3630))

SET NOCOUNT ON

DECLARE @TableName nvarchar(256), @ColumnName nvarchar(128), @SearchStr2 nvarchar(110)
SET  @TableName = ''
SET @SearchStr2 = QUOTENAME('%' + @SearchStr + '%','''')

WHILE @TableName IS NOT NULL

BEGIN
    SET @ColumnName = ''
    SET @TableName = 
    (
        SELECT MIN(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME))
        FROM     INFORMATION_SCHEMA.TABLES
        WHERE         TABLE_TYPE = 'BASE TABLE'
            AND    QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME) > @TableName
            AND    OBJECTPROPERTY(
                    OBJECT_ID(
                        QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)
                         ), 'IsMSShipped'
                           ) = 0
    )

    WHILE (@TableName IS NOT NULL) AND (@ColumnName IS NOT NULL)

    BEGIN
        SET @ColumnName =
        (
            SELECT MIN(QUOTENAME(COLUMN_NAME))
            FROM     INFORMATION_SCHEMA.COLUMNS
            WHERE         TABLE_SCHEMA    = PARSENAME(@TableName, 2)
                AND    TABLE_NAME    = PARSENAME(@TableName, 1)
                AND    DATA_TYPE IN ('char', 'varchar', 'nchar', 'nvarchar', 'int', 'decimal', 'ntext', 'xml')
                AND    QUOTENAME(COLUMN_NAME) > @ColumnName
        )

        IF @ColumnName IS NOT NULL

        BEGIN
            INSERT INTO @Results
            EXEC
            (
                'SELECT ''' + @TableName + '.' + @ColumnName + ''', LEFT((cast(' + @ColumnName + ' as nvarchar(max))), 3630) 
                FROM ' + @TableName + ' (NOLOCK) ' +
                ' WHERE (cast(' + @ColumnName + ' as nvarchar(max))) LIKE ' + @SearchStr2
            )
        END
    END    
END

SELECT ColumnName, ColumnValue FROM @Results

ROLLBACK

using javascript to detect whether the url exists before display in iframe

Due to my low reputation I couldn't comment on Derek ????'s answer. I've tried that code as it is and it didn't work well. There are three issues on Derek ????'s code.

  1. The first is that the time to async send the request and change its property 'status' is slower than to execute the next expression - if(request.status === "404"). So the request.status will eventually, due to internet band, remain on status 0 (zero), and it won't achieve the code right below if. To fix that is easy: change 'true' to 'false' on method open of the ajax request. This will cause a brief (or not so) block on your code (due to synchronous call), but will change the status of the request before reaching the test on if.

  2. The second is that the status is an integer. Using '===' javascript comparison operator you're trying to compare if the left side object is identical to one on the right side. To make this work there are two ways:

    • Remove the quotes that surrounds 404, making it an integer;
    • Use the javascript's operator '==' so you will be testing if the two objects are similar.
  3. The third is that the object XMLHttpRequest only works on newer browsers (Firefox, Chrome and IE7+). If you want that snippet to work on all browsers you have to do in the way W3Schools suggests: w3schools ajax

The code that really worked for me was:

var request;
if(window.XMLHttpRequest)
    request = new XMLHttpRequest();
else
    request = new ActiveXObject("Microsoft.XMLHTTP");
request.open('GET', 'http://www.mozilla.org', false);
request.send(); // there will be a 'pause' here until the response to come.
// the object request will be actually modified
if (request.status === 404) {
    alert("The page you are trying to reach is not available.");
}

Keras model.summary() result - Understanding the # of Parameters

The "none" in the shape means it does not have a pre-defined number. For example, it can be the batch size you use during training, and you want to make it flexible by not assigning any value to it so that you can change your batch size. The model will infer the shape from the context of the layers.

To get nodes connected to each layer, you can do the following:

for layer in model.layers:
    print(layer.name, layer.inbound_nodes, layer.outbound_nodes)

What is the official name for a credit card's 3 digit code?

You can't find a consistent reference because it seems to go by at least six different names!

  • Card Security Code
  • Card Verification Value (CVV or CV2)
  • Card Verification Value Code (CVVC)
  • Card Verification Code (CVC)
  • Verification Code (V-Code or V Code)
  • Card Code Verification (CCV)

Exit codes in Python

The exit codes only have meaning as assigned by the script author. The Unix tradition is that exit code 0 means 'success', anything else is failure. The only way to be sure what the exit codes for a given script mean is to examine the script itself.

Simple dictionary in C++

Until I was really concerned about performance, I would use a function, that takes a base and returns its match:

char base_pair(char base)
{
    switch(base) {
        case 'T': return 'A';
        ... etc
        default: // handle error
    }
}

If I was concerned about performance, I would define a base as one fourth of a byte. 0 would represent A, 1 would represent G, 2 would represent C, and 3 would represent T. Then I would pack 4 bases into a byte, and to get their pairs, I would simply take the complement.

Visual Studio move project to a different folder

No sure why all answers have overlooked at the most simple solution. Just run the "Command Prompt app" (in the windows bar search for CMD and it will appear automatically)

then just type the following command (change the path where relevant for your own case:)

robocopy /E C:\Users\Peter\source\repos D:\Peter\repos

What robocopy does is to "copies file data from one location to another." and the "secret source" is the / E that means "Copies subdirectories. This option automatically includes empty directories."

Enjoy!!! :-)

CMD Promt

H2 database error: Database may be already in use: "Locked by another process"

Ran into a similar issue the solution for me was to run fuser -k 'filename.db' on the file that had a lock associated with it.

Hope this helps!

Creating a BAT file for python script

If this is a BAT file in a different directory than the current directory, you may see an error like "python: can't open file 'somescript.py': [Errno 2] No such file or directory". This can be fixed by specifying an absolute path to the BAT file using %~dp0 (the drive letter and path of that batch file).

@echo off
python %~dp0\somescript.py %*

(This way you can ignore the c:\ or whatever, because perhaps you may want to move this script)

Visual Studio can't build due to rc.exe

In my case, I had a mix and match error between projects created in VS2015 and VS2017. In my .vcxproj file, there's this section called PropertyGroup Label="Globals">. I had a section for TargetPlatformVersion=10.0.15063.0. When I removed the TargetPlatformVersion, that solved the problem.

Sorry I can't copy and paste the block here, but stackoverflows coding format did not allow that.

Is there a rule-of-thumb for how to divide a dataset into training and validation sets?

You'd be surprised to find out that 80/20 is quite a commonly occurring ratio, often referred to as the Pareto principle. It's usually a safe bet if you use that ratio.

However, depending on the training/validation methodology you employ, the ratio may change. For example: if you use 10-fold cross validation, then you would end up with a validation set of 10% at each fold.

There has been some research into what is the proper ratio between the training set and the validation set:

The fraction of patterns reserved for the validation set should be inversely proportional to the square root of the number of free adjustable parameters.

In their conclusion they specify a formula:

Validation set (v) to training set (t) size ratio, v/t, scales like ln(N/h-max), where N is the number of families of recognizers and h-max is the largest complexity of those families.

What they mean by complexity is:

Each family of recognizer is characterized by its complexity, which may or may not be related to the VC-dimension, the description length, the number of adjustable parameters, or other measures of complexity.

Taking the first rule of thumb (i.e.validation set should be inversely proportional to the square root of the number of free adjustable parameters), you can conclude that if you have 32 adjustable parameters, the square root of 32 is ~5.65, the fraction should be 1/5.65 or 0.177 (v/t). Roughly 17.7% should be reserved for validation and 82.3% for training.

What is the { get; set; } syntax in C#?

This mean that if you create a variable of type Genre, you will be able to access the variable as a property

Genre oG = new Genre();
oG.Name = "Test";

Maximum length of HTTP GET request

Technically, I have seen HTTP GET will have issues if the URL length goes beyond 2000 characters. In that case, it's better to use HTTP POST or split the URL.

How does the modulus operator work?

You can think of the modulus operator as giving you a remainder. count % 6 divides 6 out of count as many times as it can and gives you a remainder from 0 to 5 (These are all the possible remainders because you already divided out 6 as many times as you can). The elements of the array are all printed in the for loop, but every time the remainder is 5 (every 6th element), it outputs a newline character. This gives you 6 elements per line. For 5 elements per line, use

if (count % 5 == 4)

How to add white spaces in HTML paragraph

If you really need then you can use i.e. &nbsp; entity to do that, but remember that fonts used to render your page are usually proportional, so "aligning" with spaces does not really work and looks ugly.

Best practices for SQL varchar column length

Whenever I set up a new SQL table I feel the same way about 2^n being more "even"... but to sum up the answers here, there is no significant impact on storage space simply by defining varchar(2^n) or even varchar(MAX).

That said, you should still anticipate the potential implications on storage and performance when setting a high varchar() limit. For example, let's say you create a varchar(MAX) column to hold product descriptions with full-text indexing. If 99% of descriptions are only 500 characters long, and then suddenly you get somebody who replaces said descriptions with wikipedia articles, you may notice unanticipated significant storage and performance hits.

Another thing to consider from Bill Karwin:

There's one possible performance impact: in MySQL, temporary tables and MEMORY tables store a VARCHAR column as a fixed-length column, padded out to its maximum length. If you design VARCHAR columns much larger than the greatest size you need, you will consume more memory than you have to. This affects cache efficiency, sorting speed, etc.

Basically, just come up with reasonable business constraints and error on a slightly larger size. As @onedaywhen pointed out, family names in UK are usually between 1-35 characters. If you decide to make it varchar(64), you're not really going to hurt anything... unless you're storing this guy's family name that's said to be up to 666 characters long. In that case, maybe varchar(1028) makes more sense.

And in case it's helpful, here's what varchar 2^5 through 2^10 might look like if filled:

varchar(32)     Lorem ipsum dolor sit amet amet.

varchar(64)     Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donecie

varchar(128)    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donecie
                vestibulum massa. Nullam dignissim elementum molestie. Vehiculas

varchar(256)    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donecie
                vestibulum massa. Nullam dignissim elementum molestie. Vehiculas
                velit metus, sit amet tristique purus condimentum eleifend. Quis
                que mollis magna vel massa malesuada bibendum. Proinde tincidunt

varchar(512)    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donecie
                vestibulum massa. Nullam dignissim elementum molestie. Vehiculas
                velit metus, sit amet tristique purus condimentum eleifend. Quis
                que mollis magna vel massa malesuada bibendum. Proinde tincidunt
                dolor tellus, sit amet porta neque varius vitae. Seduse molestie
                lacus id lacinia tempus. Vestibulum accumsan facilisis lorem, et
                mollis diam pretium gravida. In facilisis vitae tortor id vulput
                ate. Proin ornare arcu in sollicitudin pharetra. Crasti molestie

varchar(1024)   Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donecie
                vestibulum massa. Nullam dignissim elementum molestie. Vehiculas
                velit metus, sit amet tristique purus condimentum eleifend. Quis
                que mollis magna vel massa malesuada bibendum. Proinde tincidunt
                dolor tellus, sit amet porta neque varius vitae. Seduse molestie
                lacus id lacinia tempus. Vestibulum accumsan facilisis lorem, et
                mollis diam pretium gravida. In facilisis vitae tortor id vulput
                ate. Proin ornare arcu in sollicitudin pharetra. Crasti molestie
                dapibus leo lobortis eleifend. Vivamus vitae diam turpis. Vivamu
                nec tristique magna, vel tincidunt diam. Maecenas elementum semi
                quam. In ut est porttitor, sagittis nulla id, fermentum turpist.
                Curabitur pretium nibh a imperdiet cursus. Sed at vulputate este
                proin fermentum pretium justo, ac malesuada eros et Pellentesque
                vulputate hendrerit molestie. Aenean imperdiet a enim at finibus
                fusce ut ullamcorper risus, a cursus massa. Nunc non dapibus vel
                Lorem ipsum dolor sit amet, consectetur Praesent ut ultrices sit

How can I return two values from a function in Python?

you can try this

class select_choice():
    return x, y

a, b = test()

Java: Enum parameter in method

You could also reuse SwingConstants.{LEFT,RIGHT}. They are not enums, but they do already exist and are used in many places.

How to Position a table HTML?

You would want to use CSS to achieve that.

say you have a table with the attribute id="my_table"

You would want to write the following in your css file

#my_table{
    margin-top:10px //moves your table 10pixels down
    margin-left:10px //moves your table 10pixels right
}

if you do not have a CSS file then you may just add margin-top:10px, margin-left:10px to the style attribute in your table element like so

<table style="margin-top:10px; margin-left:10px;">
    ....
</table>

There are a lot of resources on the net describing CSS and HTML in detail

How to keep onItemSelected from firing off on a newly instantiated Spinner?

Referring to the answer of Dan Dyer, try to register the OnSelectListener in a post(Runnable) method:

spinner.post(new Runnable() {
    public void run() {
        spinner.setOnItemSelectedListener(listener);
    }
});

By doing that for me the wished behavior finally occurred.

In this case it also means that the listener only fires on a changed item.

bodyParser is deprecated express 4

What is your opinion to use express-generator it will generate skeleton project to start with, without deprecated messages appeared in your log

run this command

npm install express-generator -g

Now, create new Express.js starter application by type this command in your Node projects folder.

express node-express-app

That command tell express to generate new Node.js application with the name node-express-app.

then Go to the newly created project directory, install npm packages and start the app using the command

cd node-express-app && npm install && npm start

How to align center the text in html table row?

Selector > child:

_x000D_
_x000D_
.text-center-row>th,_x000D_
.text-center-row>td {_x000D_
  text-align: center;_x000D_
}
_x000D_
<table border="1" width='500px'>_x000D_
  <tr class="text-center-row">_x000D_
    <th>Text</th>_x000D_
    <th>Text</th>_x000D_
    <th>Text</th>_x000D_
    <th>Text</th>_x000D_
  </tr>_x000D_
  <tr>_x000D_
    <td>Text</td>_x000D_
    <td>Text</td>_x000D_
    <td>Text</td>_x000D_
    <td>Text</td>_x000D_
  </tr>_x000D_
  <tr class="text-center-row">_x000D_
    <td>Text</td>_x000D_
    <td>Text</td>_x000D_
    <td>Text</td>_x000D_
    <td>Text</td>_x000D_
  </tr>_x000D_
</table>
_x000D_
_x000D_
_x000D_

Algorithm to return all combinations of k elements from n

Here is a Lisp approach using a macro. This works in Common Lisp and should work in other Lisp dialects.

The code below creates 'n' nested loops and executes an arbitrary chunk of code (stored in the body variable) for each combination of 'n' elements from the list lst. The variable var points to a list containing the variables used for the loops.

(defmacro do-combinations ((var lst num) &body body)
  (loop with syms = (loop repeat num collect (gensym))
        for i on syms
        for k = `(loop for ,(car i) on (cdr ,(cadr i))
                         do (let ((,var (list ,@(reverse syms)))) (progn ,@body)))
                then `(loop for ,(car i) on ,(if (cadr i) `(cdr ,(cadr i)) lst) do ,k)
        finally (return k)))

Let's see...

(macroexpand-1 '(do-combinations (p '(1 2 3 4 5 6 7) 4) (pprint (mapcar #'car p))))

(LOOP FOR #:G3217 ON '(1 2 3 4 5 6 7) DO
 (LOOP FOR #:G3216 ON (CDR #:G3217) DO
  (LOOP FOR #:G3215 ON (CDR #:G3216) DO
   (LOOP FOR #:G3214 ON (CDR #:G3215) DO
    (LET ((P (LIST #:G3217 #:G3216 #:G3215 #:G3214)))
     (PROGN (PPRINT (MAPCAR #'CAR P))))))))

(do-combinations (p '(1 2 3 4 5 6 7) 4) (pprint (mapcar #'car p)))

(1 2 3 4)
(1 2 3 5)
(1 2 3 6)
...

Since combinations are not stored by default, storage is kept to a minimum. The possibility of choosing the body code instead of storing all results also affords more flexibility.

python multithreading wait till all threads finished

I just came across the same problem where I needed to wait for all the threads which were created using the for loop.I just tried out the following piece of code.It may not be the perfect solution but I thought it would be a simple solution to test:

for t in threading.enumerate():
    try:
        t.join()
    except RuntimeError as err:
        if 'cannot join current thread' in err:
            continue
        else:
            raise

Using Jasmine to spy on a function without an object

There is 2 alternative which I use (for jasmine 2)

This one is not quite explicit because it seems that the function is actually a fake.

test = createSpy().and.callFake(test); 

The second more verbose, more explicit, and "cleaner":

test = createSpy('testSpy', test).and.callThrough();

-> jasmine source code to see the second argument

How to include External CSS and JS file in Laravel 5

i use this way, don't forget to put your css file on public folder.

for example i put my bootstrap css on

"root/public/bootstrap/css/bootstrap.min.css"

to access from header:

<link href="{{ asset('bootstrap/css/bootstrap.min.css') }}" rel="stylesheet" type="text/css" >

hope this help

Convert int to a bit array in .NET

To convert the int 'x'

int x = 3;

One way, by manipulation on the int :

string s = Convert.ToString(x, 2); //Convert to binary in a string

int[] bits= s.PadLeft(8, '0') // Add 0's from left
             .Select(c => int.Parse(c.ToString())) // convert each char to int
             .ToArray(); // Convert IEnumerable from select to Array

Alternatively, by using the BitArray class-

BitArray b = new BitArray(new byte[] { x });
int[] bits = b.Cast<bool>().Select(bit => bit ? 1 : 0).ToArray();

Difference between two lists

You could do something like this:

var result = customlist.Where(p => !otherlist.Any(l => p.someproperty == l.someproperty));

Fatal error: Call to a member function fetch_assoc() on a non-object

That's because there was an error in your query. MySQli->query() will return false on error. Change it to something like::

$result = $this->database->query($query);
if (!$result) {
    throw new Exception("Database Error [{$this->database->errno}] {$this->database->error}");
}

That should throw an exception if there's an error...

AngularJS - Attribute directive input value change

To watch out the runtime changes in value of a custom directive, use $observe method of attrs object, instead of putting $watch inside a custom directive. Here is the documentation for the same ... $observe docs

Java - remove last known item from ArrayList

You need to understand java generics. You have a list of ClientThread but trying to get String. You have other errors, but this one is very basic.

Java - removing first character of a string

public String removeFirst(String input)
{
    return input.substring(1);
}

Unexpected token ILLEGAL in webkit

You can use online Minify, it removes these invisible characters efficiently but also changes your code. So be careful.

http://jscompress.com/

Twitter bootstrap 3 two columns full height

Edit: In Bootstrap 4, native classes can produce full-height columns (DEMO) because they changed their grid system to flexbox. (Read on for Bootstrap 3)


The native Bootstrap 3.0 classes don't support the layout that you describe, however, we can integrate some custom CSS which make use of css tables to achieve this.

Bootply demo / Codepen

Markup:

<header>Header</header>
<div class="container">
    <div class="row">
        <div class="col-md-3 no-float">Navigation</div>
        <div class="col-md-9 no-float">Content</div>
    </div>
</div>

(Relevant) CSS

html,body,.container {
    height:100%;
}
.container {
    display:table;
    width: 100%;
    margin-top: -50px;
    padding: 50px 0 0 0; /*set left/right padding according to needs*/
    box-sizing: border-box;
}

.row {
    height: 100%;
    display: table-row;
}

.row .no-float {
  display: table-cell;
  float: none;
}

The above code will achieve full-height columns (due to the custom css-table properties which we added) and with ratio 1:3 (Navigation:Content) for medium screen widths and above - (due to bootstrap's default classes: col-md-3 and col-md-9)

NB:

1) In order not to mess up bootstrap's native column classes we add another class like no-float in the markup and only set display:table-cell and float:none on this class (as apposed to the column classes themselves).

2) If we only want to use the css-table code for a specific break-point (say medium screen widths and above) but for mobile screens we want to default back to the usual bootstrap behavior than we can wrap our custom CSS within a media query, say:

@media (min-width: 992px) {
  .row .no-float {
      display: table-cell;
      float: none;
  }
}

Codepen demo

Now, for smaller screens, the columns will behave like default bootstrap columns (each getting full width).

3) If the 1:3 ratio is necessary for all screen widths - then it's probably a better to remove bootstrap's col-md-* classes from the markup because that's not how they are meant to be used.

Codepen demo

How can I add a username and password to Jenkins?

You need to Enable security and set the security realm on the Configure Global Security page (see: Standard Security Setup) and choose the appropriate Authorization method (Security Realm).

Jenkins Security Realm, Hudson's own user database

Depending on your selection, create the user using appropriate method. Recommended method is to select Jenkins’ own user database and tick Allow users to sign up, hit Save button, then you should be able to create user from the Jenkins interface. Otherwise if you've chosen external database, you need to create the user there (e.g. if it's Unix database, use credentials of existing Linux/Unix users or create a standard user using shell interface).

See also: Creating user in Jenkins via API

Adding event listeners to dynamically added elements using jQuery

You are dynamically generating those elements so any listener applied on page load wont be available. I have edited your fiddle with the correct solution. Basically jQuery holds the event for later binding by attaching it to the parent Element and propagating it downward to the correct dynamically created element.

$('#musics').on('change', '#want',function(e) {
    $(this).closest('.from-group').val(($('#want').is(':checked')) ? "yes" : "no");
    var ans=$(this).val();
    console.log(($('#want').is(':checked')));
});

http://jsfiddle.net/swoogie/1rkhn7ek/39/

Fetch frame count with ffmpeg

linux

ffmpeg -i "/home/iorigins/????????????/123.mov" -f null /dev/null

ruby

result = `ffmpeg -i #{path} -f null - 2>&1`
r = result.match("frame=([0-9]+)")
p r[1]

How to Sort Date in descending order From Arraylist Date in android?

Date is Comparable so just create list of List<Date> and sort it using Collections.sort(). And use Collections.reverseOrder() to get comparator in reverse ordering.

From Java Doc

Returns a comparator that imposes the reverse ordering of the specified comparator. If the specified comparator is null, this method is equivalent to reverseOrder() (in other words, it returns a comparator that imposes the reverse of the natural ordering on a collection of objects that implement the Comparable interface).

How to use format() on a moment.js duration?

Based on ni-ko-o-kin's answer:

meassurements = ["years", "months", "weeks", "days", "hours", "minutes", "seconds"];
withPadding = (duration) => {
    var step = null;
    return meassurements.map((m) => duration[m]()).filter((n,i,a) => {
        var nonEmpty = Boolean(n);
        if (nonEmpty || step || i >= a.length - 2) {
            step = true;
        }
        return step;
    }).map((n) => ('0' + n).slice(-2)).join(':')
}

duration1 = moment.duration(1, 'seconds');
duration2 = moment.duration(7200, 'seconds');
duration3 = moment.duration(604800, 'seconds');

withPadding(duration1); // 00:01
withPadding(duration2); // 02:00:00
withPadding(duration3); // 01:07:00:00:00

How to convert An NSInteger to an int?

If you want to do this inline, just cast the NSUInteger or NSInteger to an int:

int i = -1;
NSUInteger row = 100;
i > row // true, since the signed int is implicitly converted to an unsigned int
i > (int)row // false

Error inflating class fragment

If your TaskDetailsFragment extending android.app.Fragment, do change in onCreateView().

Return your view which you want to show in the Fragment or convert your Layout to view by using LayoutInflater and return it.

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View mainview = inflater.inflate(R.layout.main, null);
    return mainview;
}

Hope this works. :)

const vs constexpr on variables

I believe there is a difference. Let's rename them so that we can talk about them more easily:

const     double PI1 = 3.141592653589793;
constexpr double PI2 = 3.141592653589793;

Both PI1 and PI2 are constant, meaning you can not modify them. However only PI2 is a compile-time constant. It shall be initialized at compile time. PI1 may be initialized at compile time or run time. Furthermore, only PI2 can be used in a context that requires a compile-time constant. For example:

constexpr double PI3 = PI1;  // error

but:

constexpr double PI3 = PI2;  // ok

and:

static_assert(PI1 == 3.141592653589793, "");  // error

but:

static_assert(PI2 == 3.141592653589793, "");  // ok

As to which you should use? Use whichever meets your needs. Do you want to ensure that you have a compile time constant that can be used in contexts where a compile-time constant is required? Do you want to be able to initialize it with a computation done at run time? Etc.

OSX - How to auto Close Terminal window after the "exit" command executed.

Create a script:

cat ~/exit.scpt

like this:

  • Note: If there is only one window, just quit the application, else simulate command + w to close the tab)

tell application "Terminal" set WindowNum to get window count if WindowNum = 1 then quit else tell application "System Events" to keystroke "w" using command down end if end tell

Then add a alias in your *shrc

just like vi ~/.bashrc or zshrc (anything else?)

add it: alias exit="osascript ~/exit.scpt"

And source the ~/.bashrc or reopen your terminal.app

Split string into array of character strings

If the original string contains supplementary Unicode characters, then split() would not work, as it splits these characters into surrogate pairs. To correctly handle these special characters, a code like this works:

String[] chars = new String[stringToSplit.codePointCount(0, stringToSplit.length())];
for (int i = 0, j = 0; i < stringToSplit.length(); j++) {
    int cp = stringToSplit.codePointAt(i);
    char c[] = Character.toChars(cp);
    chars[j] = new String(c);
    i += Character.charCount(cp);
}

Spring 3 MVC accessing HttpRequest from controller

Spring MVC will give you the HttpRequest if you just add it to your controller method signature:

For instance:

/**
 * Generate a PDF report...
 */
@RequestMapping(value = "/report/{objectId}", method = RequestMethod.GET)
public @ResponseBody void generateReport(
        @PathVariable("objectId") Long objectId, 
        HttpServletRequest request, 
        HttpServletResponse response) {

    // ...
    // Here you can use the request and response objects like:
    // response.setContentType("application/pdf");
    // response.getOutputStream().write(...);

}

As you see, simply adding the HttpServletRequest and HttpServletResponse objects to the signature makes Spring MVC to pass those objects to your controller method. You'll want the HttpSession object too.

EDIT: It seems that HttpServletRequest/Response are not working for some people under Spring 3. Try using Spring WebRequest/WebResponse objects as Eduardo Zola pointed out.

I strongly recommend you to have a look at the list of supported arguments that Spring MVC is able to auto-magically inject to your handler methods.

How to return a specific status code and no contents from Controller?

The best way to do it is:

return this.StatusCode(StatusCodes.Status418ImATeapot, "Error message");

'StatusCodes' has every kind of return status and you can see all of them in this link https://httpstatuses.com/

Once you choose your StatusCode, return it with a message.

PivotTable to show values, not sum of values

I fear this might turn out to BE the long way round but could depend on how big your data set is – presumably more than four months for example.

Assuming your data is in ColumnA:C and has column labels in Row 1, also that Month is formatted mmm(this last for ease of sorting):

  1. Sort the data by Name then Month
  2. Enter in D2 =IF(AND(A2=A1,C2=C1),D1+1,1) (One way to deal with what is the tricky issue of multiple entries for the same person for the same month).
  3. Create a pivot table from A1:D(last occupied row no.)
  4. Say insert in F1.
  5. Layout as in screenshot.

SO12803305 example

I’m hoping this would be adequate for your needs because pivot table should automatically update (provided range is appropriate) in response to additional data with refresh. If not (you hard taskmaster), continue but beware that the following steps would need to be repeated each time the source data changes.

  1. Copy pivot table and Paste Special/Values to, say, L1.
  2. Delete top row of copied range with shift cells up.
  3. Insert new cell at L1 and shift down.
  4. Key 'Name' into L1.
  5. Filter copied range and for ColumnL, select Row Labels and numeric values.
  6. Delete contents of L2:L(last selected cell)
  7. Delete blank rows in copied range with shift cells up (may best via adding a column that counts all 12 months). Hopefully result should be as highlighted in yellow.

Happy to explain further/try again (I've not really tested this) if does not suit.

EDIT (To avoid second block of steps above and facilitate updating for source data changes)

.0. Before first step 2. add a blank row at the very top and move A2:D2 up.
.2. Adjust cell references accordingly (in D3 =IF(AND(A3=A2,C3=C2),D2+1,1).
.3. Create pivot table from A:D

.6. Overwrite Row Labels with Name.
.7. PivotTable Tools, Design, Report Layout, Show in Tabular Form and sort rows and columns A>Z.
.8. Hide Row1, ColumnG and rows and columns that show (blank).

additional example

Steps .0. and .2. in the edit are not required if the pivot table is in a different sheet from the source data (recommended).

Step .3. in the edit is a change to simplify the consequences of expanding the source data set. However introduces (blank) into pivot table that if to be hidden may need adjustment on refresh. So may be better to adjust source data range each time that changes instead: PivotTable Tools, Options, Change Data Source, Change Data Source, Select a table or range). In which case copy rather than move in .0.

Where does PostgreSQL store the database?

Under my Linux installation, it's here: /var/lib/postgresql/8.x/

You can change it with initdb -D "c:/mydb/"

Syntax for an If statement using a boolean

You can change the value of a bool all you want. As for an if:

if randombool == True:

works, but you can also use:

if randombool:

If you want to test whether something is false you can use:

if randombool == False

but you can also use:

if not randombool:

Can I use library that used android support with Androidx projects.

Manually adding android.useAndroidX=true and android.enableJetifier=true giving me hard time. Because it's throw some error or Suggestion: add 'tools:replace="android:appComponentFactory"' to <application>

To Enable Jet-fire in project there is option in android Studio

Select Your Project ---> Right Click

app----> Refactor ----> Migrate to AndroidX

Shown in below image:-

enter image description here

After click on Migrate to AndroidX.

It will ask for confirmation and back up for your project.

enter image description here

And last step it will ask you for to do refactor.

enter image description here

After doing Refactor check your gradle.properties have android.useAndroidX=true and android.enableJetifier=true. If they are not then add these two lines to your gradle.properties file:

android.useAndroidX=true
android.enableJetifier=true

Note:- Upgrading using Android Studio, this option works if you have android studio 3.2 and onward. Check this

Focus Input Box On Load

$(document).ready(function() {
    $('#id').focus();
});

How do you merge two Git repositories?

If you're trying to simply glue two repositories together, submodules and subtree merges are the wrong tool to use because they don't preserve all of the file history (as people have noted on other answers). See this answer here for the simple and correct way to do this.

How to securely save username/password (local)?

This only works on Windows, so if you are planning to use dotnet core cross-platform, you'll have to look elsewhere. See https://github.com/dotnet/corefx/blob/master/Documentation/architecture/cross-platform-cryptography.md

Delete specific values from column with where condition?

UPDATE YourTable SET columnName = null WHERE YourCondition

IOCTL Linux device driver

An ioctl, which means "input-output control" is a kind of device-specific system call. There are only a few system calls in Linux (300-400), which are not enough to express all the unique functions devices may have. So a driver can define an ioctl which allows a userspace application to send it orders. However, ioctls are not very flexible and tend to get a bit cluttered (dozens of "magic numbers" which just work... or not), and can also be insecure, as you pass a buffer into the kernel - bad handling can break things easily.

An alternative is the sysfs interface, where you set up a file under /sys/ and read/write that to get information from and to the driver. An example of how to set this up:

static ssize_t mydrvr_version_show(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    return sprintf(buf, "%s\n", DRIVER_RELEASE);
}

static DEVICE_ATTR(version, S_IRUGO, mydrvr_version_show, NULL);

And during driver setup:

device_create_file(dev, &dev_attr_version);

You would then have a file for your device in /sys/, for example, /sys/block/myblk/version for a block driver.

Another method for heavier use is netlink, which is an IPC (inter-process communication) method to talk to your driver over a BSD socket interface. This is used, for example, by the WiFi drivers. You then communicate with it from userspace using the libnl or libnl3 libraries.

How to install and run Typescript locally in npm?

It took me a while to figure out the solution to this problem - it's in the original question. You need to have a script that calls tsc in your package.json file so that you can run:

npm run tsc 

Include -- before you pass in options (or just include them in the script):

npm run tsc -- -v

Here's an example package.json:

{
  "name": "foo",
  "scripts": {
    "tsc": "tsc"
  },
  "dependencies": {
    "typescript": "^1.8.10"
  }
}

Is there a way to define a min and max value for EditText in Android?

Of what i've seen of @Patrik's solution and @Zac's addition, the code provided still has a big problem :

If min==3 then it's impossible to type any number starting with 1 or 2 (ex: 15, 23)
If min>=10 then it's impossible to type anything as every number will have to start with 1,2,3...

In my understanding we cannot achieve the min-max limitation of an EditText's value with simple use of the class InputFilterMinMax, at least not for the min Value, because when user is typing a positive number, the value goes growing and we can easily perform an on-the-fly test to check if it's reached the limit or went outside the range and block entries that do not comply. Testing the min value is a different story as we cannot be sure if the user has finished typing or not and therefore cannot decide if we should block or not.

It's not exactly what OP requested but for validation purposes i've combined in my solution an InputFilter to test max values, with an OnFocusChangeListener to re-test for min value when the EditText loses the focus assuming the user's finished typing and it's something like this :

package test;


import android.text.InputFilter;

import android.text.Spanned;

public class InputFilterMax implements InputFilter {

private int max;

public InputFilterMax(int max) {
    this.max = max;
}

public InputFilterMax(String max) {
    this.max = Integer.parseInt(max);
}

@Override
public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {   
    try {
        String replacement = source.subSequence(start, end).toString(); 

        String newVal = dest.toString().substring(0, dstart) + replacement +dest.toString().substring(dend, dest.toString().length());

        int input = Integer.parseInt(newVal);

        if (input<=max)
            return null;
    } catch (NumberFormatException nfe) { }   
//Maybe notify user that the value is not good      
return "";
}
}

And OnFocusChangeListenerMin

package test;

import android.text.TextUtils;
import android.view.View;
import android.view.View.OnFocusChangeListener;

public class OnFocusChangeListenerMin implements OnFocusChangeListener {

private int min;

public OnFocusChangeListenerMin(int min) {
    this.min = min;
}

public OnFocusChangeListenerMin(String min) {
    this.min = Integer.parseInt(min);
}


@Override
public void onFocusChange(View v, boolean hasFocus) {
    if(!hasFocus) {
        String val = ((EditText)v).getText().toString();
        if(!TextUtils.isEmpty(val)){
            if(Integer.valueOf(val)<min){
                //Notify user that the value is not good
            }

        }
    }
}
}

Then in Activity set the InputFilterMax and theOnFocusChangeListenerMin to EditText note : You can 2 both min and max in onFocusChangeListener.

mQteEditText.setOnFocusChangeListener( new OnFocusChangeListenerMin('20');
mQteEditText.setFilters(new InputFilter[]{new InputFilterMax(getActivity(),'50')});

Calculating Page Table Size

Since we have a virtual address space of 2^32 and each page size is 2^12, we can store (2^32/2^12) = 2^20 pages. Since each entry into this page table has an address of size 4 bytes, then we have 2^20*4 = 4MB. So the page table takes up 4MB in memory.

Understanding offsetWidth, clientWidth, scrollWidth and -Height, respectively

If you want to use scrollWidth to get the "REAL" CONTENT WIDTH/HEIGHT (as content can be BIGGER than the css-defined width/height-Box) the scrollWidth/Height is very UNRELIABLE as some browser seem to "MOVE" the paddingRIGHT & paddingBOTTOM if the content is to big. They then place the paddings at the RIGHT/BOTTOM of the "too broad/high content" (see picture below).

==> Therefore to get the REAL CONTENT WIDTH in some browsers you have to substract BOTH paddings from the scrollwidth and in some browsers you only have to substract the LEFT Padding.

I found a solution for this and wanted to add this as a comment, but was not allowed. So I took the picture and made it a bit clearer in the regard of the "moved paddings" and the "unreliable scrollWidth". In the BLUE AREA you find my solution on how to get the "REAL" CONTENT WIDTH!

Hope this helps to make things even clearer!

enter image description here

How can I use async/await at the top level?

Since main() runs asynchronously it returns a promise. You have to get the result in then() method. And because then() returns promise too, you have to call process.exit() to end the program.

main()
   .then(
      (text) => { console.log('outside: ' + text) },
      (err)  => { console.log(err) }
   )
   .then(() => { process.exit() } )

What is the difference between java and core java?

Java is programming language but Core java is just a part of java. Core java is the basic of java. If you are new to JAVA then you have to start with core java.

Java is basically categories in 3 parts :

1.) J2SE / Core java stands for Java 2 standard edition and is normally for developing desktop applications, forms the core/base API.

2.) J2EE stands for Java 2 enterprise edition for applications which run on servers, for example web sites. (Spring, Struts are the java frameworks mainly used for J2EE)

3.) J2ME stands for Java 2 micro edition for applications which run on resource constrained devices (small scale devices) like cell phones, for example games.

To learn J2EE or J2ME, you should know core java.

PostgreSQL naming conventions

There isn't really a formal manual, because there's no single style or standard.

So long as you understand the rules of identifier naming you can use whatever you like.

In practice, I find it easier to use lower_case_underscore_separated_identifiers because it isn't necessary to "Double Quote" them everywhere to preserve case, spaces, etc.

If you wanted to name your tables and functions "@MyA??! ""betty"" Shard$42" you'd be free to do that, though it'd be pain to type everywhere.

The main things to understand are:

  • Unless double-quoted, identifiers are case-folded to lower-case, so MyTable, MYTABLE and mytable are all the same thing, but "MYTABLE" and "MyTable" are different;

  • Unless double-quoted:

    SQL identifiers and key words must begin with a letter (a-z, but also letters with diacritical marks and non-Latin letters) or an underscore (_). Subsequent characters in an identifier or key word can be letters, underscores, digits (0-9), or dollar signs ($).

  • You must double-quote keywords if you wish to use them as identifiers.

In practice I strongly recommend that you do not use keywords as identifiers. At least avoid reserved words. Just because you can name a table "with" doesn't mean you should.

If/else else if in Jquery for a condition

Iam confused a lot from morning whether it should be less than or greater than`

this can accept value less than "99999"

I think you answered it yourself... But it's valid when it's less than. Thus the following is incorrect:

}elseif($("#seats").val() < 99999){
  alert("Not a valid Number");
}else{

You are saying if it's less than 99999, then it's not valid. You want to do the opposite:

}elseif($("#seats").val() >= 99999){
  alert("Not a valid Number");
}else{

Also, since you have $("#seats") twice, jQuery has to search the DOM twice. You should really be storing the value, or at least the DOM element in a variable. And some more of your code doesn't make much sense, so I'm going to make some assumptions and put it all together:

var seats = $("#seats").val();

var error = null;

if (seats == "") {
    error = "Number is required";
} else {
    var seatsNum = parseInt(seats);
    
    if (isNaN(seatsNum)) {
        error = "Not a valid number";
    } else if (seatsNum >= 99999) {
        error = "Number must be less than 99999";
    }
}

if (error != null) {
    alert(error);
} else {
    alert("Valid number");
}

// If you really need setflag:
var setflag = error != null;

Here's a working sample: http://jsfiddle.net/LUY8q/