Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $

In my case ; what solved my issue was.....

You may had json like this, the keys without " double quotations....

{ name: "test", phone: "2324234" }

So try any online Json Validator to make sure you have right syntax...

Error reading JObject from JsonReader. Current JsonReader item is not an object: StartArray. Path

In this case that you know that you have all items in the first place on array you can parse the string to JArray and then parse the first item using JObject.Parse

var  jsonArrayString = @"
[
  {
    ""country"": ""India"",
    ""city"": ""Mall Road, Gurgaon"",
  },
  {
    ""country"": ""India"",
    ""city"": ""Mall Road, Kanpur"",
  }
]";
JArray jsonArray = JArray.Parse(jsonArrayString);
dynamic data = JObject.Parse(jsonArray[0].ToString());

how to parse JSON file with GSON

You have to fetch the whole data in the list and then do the iteration as it is a file and will become inefficient otherwise.

private static final Type REVIEW_TYPE = new TypeToken<List<Review>>() {
}.getType();
Gson gson = new Gson();
JsonReader reader = new JsonReader(new FileReader(filename));
List<Review> data = gson.fromJson(reader, REVIEW_TYPE); // contains the whole reviews list
data.toScreen(); // prints to screen some values

NewtonSoft.Json Serialize and Deserialize class with property of type IEnumerable<ISomeInterface>

You don't need to use JsonConverterAttribute, keep your model clean, also use CustomCreationConverter, the code is simpler:

public class SampleConverter : CustomCreationConverter<ISample>
{
    public override ISample Create(Type objectType)
    {
        return new Sample();
    }
}

Then:

var sz = JsonConvert.SerializeObject( sampleGroupInstance );
JsonConvert.DeserializeObject<SampleGroup>( sz, new SampleConverter());

Documentation: Deserialize with CustomCreationConverter

What is an example of the simplest possible Socket.io example?

Edit: I feel it's better for anyone to consult the excellent chat example on the Socket.IO getting started page. The API has been quite simplified since I provided this answer. That being said, here is the original answer updated small-small for the newer API.

Just because I feel nice today:

index.html

<!doctype html>
<html>
    <head>
        <script src='/socket.io/socket.io.js'></script>
        <script>
            var socket = io();

            socket.on('welcome', function(data) {
                addMessage(data.message);

                // Respond with a message including this clients' id sent from the server
                socket.emit('i am client', {data: 'foo!', id: data.id});
            });
            socket.on('time', function(data) {
                addMessage(data.time);
            });
            socket.on('error', console.error.bind(console));
            socket.on('message', console.log.bind(console));

            function addMessage(message) {
                var text = document.createTextNode(message),
                    el = document.createElement('li'),
                    messages = document.getElementById('messages');

                el.appendChild(text);
                messages.appendChild(el);
            }
        </script>
    </head>
    <body>
        <ul id='messages'></ul>
    </body>
</html>

app.js

var http = require('http'),
    fs = require('fs'),
    // NEVER use a Sync function except at start-up!
    index = fs.readFileSync(__dirname + '/index.html');

// Send index.html to all requests
var app = http.createServer(function(req, res) {
    res.writeHead(200, {'Content-Type': 'text/html'});
    res.end(index);
});

// Socket.io server listens to our app
var io = require('socket.io').listen(app);

// Send current time to all connected clients
function sendTime() {
    io.emit('time', { time: new Date().toJSON() });
}

// Send current time every 10 secs
setInterval(sendTime, 10000);

// Emit welcome message on connection
io.on('connection', function(socket) {
    // Use socket to communicate with this particular client only, sending it it's own id
    socket.emit('welcome', { message: 'Welcome!', id: socket.id });

    socket.on('i am client', console.log);
});

app.listen(3000);

Lock, mutex, semaphore... what's the difference?

There are a lot of misconceptions regarding these words.

This is from a previous post (https://stackoverflow.com/a/24582076/3163691) which fits superb here:

1) Critical Section= User object used for allowing the execution of just one active thread from many others within one process. The other non selected threads (@ acquiring this object) are put to sleep.

[No interprocess capability, very primitive object].

2) Mutex Semaphore (aka Mutex)= Kernel object used for allowing the execution of just one active thread from many others, among different processes. The other non selected threads (@ acquiring this object) are put to sleep. This object supports thread ownership, thread termination notification, recursion (multiple 'acquire' calls from same thread) and 'priority inversion avoidance'.

[Interprocess capability, very safe to use, a kind of 'high level' synchronization object].

3) Counting Semaphore (aka Semaphore)= Kernel object used for allowing the execution of a group of active threads from many others. The other non selected threads (@ acquiring this object) are put to sleep.

[Interprocess capability however not very safe to use because it lacks following 'mutex' attributes: thread termination notification, recursion?, 'priority inversion avoidance'?, etc].

4) And now, talking about 'spinlocks', first some definitions:

Critical Region= A region of memory shared by 2 or more processes.

Lock= A variable whose value allows or denies the entrance to a 'critical region'. (It could be implemented as a simple 'boolean flag').

Busy waiting= Continuosly testing of a variable until some value appears.

Finally:

Spin-lock (aka Spinlock)= A lock which uses busy waiting. (The acquiring of the lock is made by xchg or similar atomic operations).

[No thread sleeping, mostly used at kernel level only. Ineffcient for User level code].

As a last comment, I am not sure but I can bet you some big bucks that the above first 3 synchronizing objects (#1, #2 and #3) make use of this simple beast (#4) as part of their implementation.

Have a good day!.

References:

-Real-Time Concepts for Embedded Systems by Qing Li with Caroline Yao (CMP Books).

-Modern Operating Systems (3rd) by Andrew Tanenbaum (Pearson Education International).

-Programming Applications for Microsoft Windows (4th) by Jeffrey Richter (Microsoft Programming Series).

Also, you can take a look at look at: https://stackoverflow.com/a/24586803/3163691

Line Break in XML?

<description><![CDATA[first line<br/>second line<br/>]]></description>

How to set 00:00:00 using moment.js

Moment.js stores dates it utc and can apply different timezones to it. By default it applies your local timezone. If you want to set time on utc date time you need to specify utc timezone.

Try the following code:

var m = moment().utcOffset(0);
m.set({hour:0,minute:0,second:0,millisecond:0})
m.toISOString()
m.format()

How to read/write files in .Net Core?

For writing any Text to a file.

public static void WriteToFile(string DirectoryPath,string FileName,string Text)
    {
        //Check Whether directory exist or not if not then create it
        if(!Directory.Exists(DirectoryPath))
        {
            Directory.CreateDirectory(DirectoryPath);
        }

        string FilePath = DirectoryPath + "\\" + FileName;
        //Check Whether file exist or not if not then create it new else append on same file
        if (!File.Exists(FilePath))
        {
            File.WriteAllText(FilePath, Text);
        }
        else
        {
            Text = $"{Environment.NewLine}{Text}";
            File.AppendAllText(FilePath, Text);
        }
    }

For reading a Text from file

public static string ReadFromFile(string DirectoryPath,string FileName)
    {
        if (Directory.Exists(DirectoryPath))
        {
            string FilePath = DirectoryPath + "\\" + FileName;
            if (File.Exists(FilePath))
            {
                return File.ReadAllText(FilePath);
            }
        }
        return "";
    }

For Reference here this is the official microsoft document link.

Select all columns except one in MySQL?

You can do:

SELECT column1, column2, column4 FROM table WHERE whatever

without getting column3, though perhaps you were looking for a more general solution?

Using Camera in the Android emulator

Update: ICS emulator supports camera.

How to resolve 'npm should be run outside of the node repl, in your normal shell'

As mscdex said NPM comes with the nodejs msi installed file. I happened to just install the node js installer (standalone). To separately add NPM I followed following step

Download the latest zip file of NPM from here.
Extract it in the same file as that of node js installer.
If you have added the directory containing to node js installer to PATH env variable then now even npm should be a recognized command.

How to create a laravel hashed password

You can use the following:

$hashed_password = Hash::make('Your Unhashed Password');

You can find more information: here

Position of a string within a string using Linux shell script?

You can use grep to get the byte-offset of the matching part of a string:

echo $str | grep -b -o str

As per your example:

[user@host ~]$ echo "The cat sat on the mat" | grep -b -o cat
4:cat

you can pipe that to awk if you just want the first part

echo $str | grep -b -o str | awk 'BEGIN {FS=":"}{print $1}'

"X does not name a type" error in C++

It is always encouraged in C++ that you have one class per header file, see this discussion in SO [1]. GManNickG answer's tells why this happen. But the best way to solve this is to put User class in one header file (User.h) and MyMessageBox class in another header file (MyMessageBox.h). Then in your User.h you include MyMessageBox.h and in MyMessageBox.h you include User.h. Do not forget "include gaurds" [2] so that your code compiles successfully.

Javascript Append Child AFTER Element

This suffices :

 parentGuest.parentNode.insertBefore(childGuest, parentGuest.nextSibling || null);

since if the refnode (second parameter) is null, a regular appendChild is performed. see here : http://reference.sitepoint.com/javascript/Node/insertBefore

Actually I doubt that the || null is required, try it and see.

How can I pass a Bitmap object from one activity to another

You can create a bitmap transfer. try this....

In the first class:

1) Create:

private static Bitmap bitmap_transfer;

2) Create getter and setter

public static Bitmap getBitmap_transfer() {
    return bitmap_transfer;
}

public static void setBitmap_transfer(Bitmap bitmap_transfer_param) {
    bitmap_transfer = bitmap_transfer_param;
}

3) Set the image:

ImageView image = (ImageView) view.findViewById(R.id.image);
image.buildDrawingCache();
setBitmap_transfer(image.getDrawingCache());

Then, in the second class:

ImageView image2 = (ImageView) view.findViewById(R.id.img2);
imagem2.setImageDrawable(new BitmapDrawable(getResources(), classe1.getBitmap_transfer()));

What is the difference between a .cpp file and a .h file?

.h files, or header files, are used to list the publicly accessible instance variables and and methods in the class declaration. .cpp files, or implementation files, are used to actually implement those methods and use those instance variables.

The reason they are separate is because .h files aren't compiled into binary code while .cpp files are. Take a library, for example. Say you are the author and you don't want it to be open source. So you distribute the compiled binary library and the header files to your customers. That allows them to easily see all the information about your library's classes they can use without being able to see how you implemented those methods. They are more for the people using your code rather than the compiler. As was said before: it's the convention.

Replacing H1 text with a logo image: best method for SEO and accessibility?

You're missing the option:

<h1>
  <a href="http://stackoverflow.com">
    <img src="logo.png" alt="Stack Overflow" />
  </a>
</h1>

title in href and img to h1 is very, very important!

How to view user privileges using windows cmd?

You can use the following commands:

whoami /priv
whoami /all

For more information, check whoami @ technet.

Remove xticks in a matplotlib plot?

Here is an alternative solution that I found on the matplotlib mailing list:

import matplotlib.pylab as plt

x = range(1000)
ax = plt.axes()
ax.semilogx(x, x)
ax.xaxis.set_ticks_position('none')

graph

Fast and simple String encrypt/decrypt in JAVA

If you are using Android then you can use android.util.Base64 class.

Encode:

passwd = Base64.encodeToString( passwd.getBytes(), Base64.DEFAULT );

Decode:

passwd = new String( Base64.decode( passwd, Base64.DEFAULT ) );

A simple and fast single line solution.

How can I parse a CSV string with JavaScript, which contains comma in data?

You can use papaparse.js like the example below:

<!DOCTYPE html>
<html lang="en">

    <head>
        <title>CSV</title>
    </head>

    <body>
        <input type="file" id="files" multiple="">
        <button onclick="csvGetter()">CSV Getter</button>
        <h3>The Result will be in the Console.</h3>

        <script src="papaparse.min.js"></script>

        <script>
            function csvGetter() {

                var file = document.getElementById('files').files[0];
                Papa.parse(file, {
                    complete: function(results) {
                        console.log(results.data);
                    }
                });
            }
          </script>
    </body>

</html>

Don't forget to include papaparse.js in the same folder.

Errors in SQL Server while importing CSV file despite varchar(MAX) being used for each column

Issue: The Jet OLE DB provider reads a registry key to determine how many rows are to be read to guess the type of the source column. By default, the value for this key is 8. Hence, the provider scans the first 8 rows of the source data to determine the data types for the columns. If any field looks like text and the length of data is more than 255 characters, the column is typed as a memo field. So, if there is no data with a length greater than 255 characters in the first 8 rows of the source, Jet cannot accurately determine the nature of the data type. As the first 8 row length of data in the exported sheet is less than 255 its considering the source length as VARCHAR(255) and unable to read data from the column having more length.

Fix: The solution is just to sort the comment column in descending order. In 2012 onwards we can update the values in Advance tab in the Import wizard.

Decimal or numeric values in regular expression validation

Here is a great working regex for numbers. This accepts number with commas and decimals.

/^-?(?:\d+|\d{1,3}(?:,\d{3})+)?(?:\.\d+)?$/

Getting title and meta tags from external website

Shouldnt we be using OG?

The chosen answer is good but doesn't work when a site is redirected (very common!), and doesn't return OG tags, which are the new industry standard. Here's a little function which is a bit more usable in 2018. It tries to get OG tags and falls back to meta tags if it cant them:

function getSiteOG( $url, $specificTags=0 ){
    $doc = new DOMDocument();
    @$doc->loadHTML(file_get_contents($url));
    $res['title'] = $doc->getElementsByTagName('title')->item(0)->nodeValue;

    foreach ($doc->getElementsByTagName('meta') as $m){
        $tag = $m->getAttribute('name') ?: $m->getAttribute('property');
        if(in_array($tag,['description','keywords']) || strpos($tag,'og:')===0) $res[str_replace('og:','',$tag)] = $m->getAttribute('content');
    }
    return $specificTags? array_intersect_key( $res, array_flip($specificTags) ) : $res;
}

How to use it:

/////////////
//SAMPLE USAGE:
print_r(getSiteOG("http://www.stackoverflow.com")); //note the incorrect url

/////////////
//OUTPUT:
Array
(
    [title] => Stack Overflow - Where Developers Learn, Share, & Build Careers
    [description] => Stack Overflow is the largest, most trusted online community for developers to learn, shareâ âtheir programming âknowledge, and build their careers.
    [type] => website
    [url] => https://stackoverflow.com/
    [site_name] => Stack Overflow
    [image] => https://cdn.sstatic.net/Sites/stackoverflow/img/[email protected]?v=73d79a89bded
)

Add a new item to a dictionary in Python

It can be as simple as:

default_data['item3'] = 3

As Chris' answer says, you can use update to add more than one item. An example:

default_data.update({'item4': 4, 'item5': 5})

Please see the documentation about dictionaries as data structures and dictionaries as built-in types.

Auto margins don't center image in page

For a bootstrap button:

display: table; 
margin: 0 auto;

Password encryption at client side

This sort of protection is normally provided by using HTTPS, so that all communication between the web server and the client is encrypted.

The exact instructions on how to achieve this will depend on your web server.

The Apache documentation has a SSL Configuration HOW-TO guide that may be of some help. (thanks to user G. Qyy for the link)

How to call a method after a delay in Android

If you have to use the Handler, but you are into another thread, you can use runonuithread to run the handler in UI thread. This will save you from Exceptions thrown asking to call Looper.Prepare()

runOnUiThread(new Runnable() {
    @Override
    public void run() {
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                //Do something after 1 second
            }
        }, 1000);
    }
});

Looks quite messy, but this is one of the way.

Target WSGI script cannot be loaded as Python module

I had a similar problem with this error message in the logs:

Target WSGI script '/home/web2py/wsgihandler.py' cannot be loaded as Python module.

The solution was the deletion of an incorrect WSGIPythonHome directive (pointing to the application directory) from /etc/httpd/conf.d/wsgi.conf

I'm on RedHat using CentOS repositories.

Recommend following Graham Dumpleton's installation/configuration instructions. Testing configuration against the helloworld application showed me that mod_wsgi was working and the configuration was at fault.

However, the error message gave little clue as to what was wrong.

Can you have a <span> within a <span>?

Yes. You can have a span within a span. Your problem stems from something else.

Checking if a list is empty with LINQ

I just wrote up a quick test, try this:

 IEnumerable<Object> myList = new List<Object>();

 Stopwatch watch = new Stopwatch();

 int x;

 watch.Start();
 for (var i = 0; i <= 1000000; i++)
 {
    if (myList.Count() == 0) x = i; 
 }
 watch.Stop();

 Stopwatch watch2 = new Stopwatch();

 watch2.Start();
 for (var i = 0; i <= 1000000; i++)
 {
     if (!myList.Any()) x = i;
 }
 watch2.Stop();

 Console.WriteLine("myList.Count() = " + watch.ElapsedMilliseconds.ToString());
 Console.WriteLine("myList.Any() = " + watch2.ElapsedMilliseconds.ToString());
 Console.ReadLine();

The second is almost three times slower :)

Trying the stopwatch test again with a Stack or array or other scenarios it really depends on the type of list it seems - because they prove Count to be slower.

So I guess it depends on the type of list you're using!

(Just to point out, I put 2000+ objects in the List and count was still faster, opposite with other types)

Ubuntu - Run command on start-up with "sudo"

Edit the tty configuration in /etc/init/tty*.conf with a shellscript as a parameter :

(...)
exec /sbin/getty -n -l  theInputScript.sh -8 38400 tty1
(...)

This is assuming that we're editing tty1 and the script that reads input is theInputScript.sh.

A word of warning this script is run as root, so when you are inputing stuff to it you have root priviliges. Also append a path to the location of the script.

Important: the script when it finishes, has to invoke the /sbin/login otherwise you wont be able to login in the terminal.

resize2fs: Bad magic number in super-block while trying to open

After a bit of trial and error... as mentioned in the possible answers, it turned out to require xfs_growfs rather than resize2fs.

CentOS 7,

fdisk /dev/xvda

Create new primary partition, set type as linux lvm.

n
p
3
t
8e
w

Create a new primary volume and extend the volume group to the new volume.

partprobe
pvcreate /dev/xvda3
vgextend /dev/centos /dev/xvda3

Check the physical volume for free space, extend the logical volume with the free space.

vgdisplay -v
lvextend -l+288 /dev/centos/root

Finally perform an online resize to resize the logical volume, then check the available space.

xfs_growfs /dev/centos/root
df -h

How to convert Moment.js date to users local timezone?

You do not need to use moment-timezone for this. The main moment.js library has full functionality for working with UTC and the local time zone.

var testDateUtc = moment.utc("2015-01-30 10:00:00");
var localDate = moment(testDateUtc).local();

From there you can use any of the functions you might expect:

var s = localDate.format("YYYY-MM-DD HH:mm:ss");
var d = localDate.toDate();
// etc...

Note that by passing testDateUtc, which is a moment object, back into the moment() constructor, it creates a clone. Otherwise, when you called .local(), it would also change the testDateUtc value, instead of just the localDate value. Moments are mutable.

Also note that if your original input contains a time zone offset such as +00:00 or Z, then you can just parse it directly with moment. You don't need to use .utc or .local. For example:

var localDate = moment("2015-01-30T10:00:00Z");

Static methods in Python?

Yes, check out the staticmethod decorator:

>>> class C:
...     @staticmethod
...     def hello():
...             print "Hello World"
...
>>> C.hello()
Hello World

Test credit card numbers for use with PayPal sandbox

If a credit card is already added to a PayPal account then it won't let you use that card to process directly with Payments Advanced. The system expects buyers to login to PayPal and just choose that credit card as their funding source if they want to pay with it.

As for testing on the sandbox, I've always used old, expired credit cards I have laying around and they seem to work fine for me.

You could always try the ones starting on page 87 of the PayFlow documentation, too. They should work.

Why does git status show branch is up-to-date when changes exist upstream?

"origin/master" refers to the reference poiting to the HEAD commit of branch "origin/master". A reference is a human-friendly alias name to a Git object, typically a commit object. "origin/master" reference only gets updated when you git push to your remote (http://git-scm.com/book/en/v2/Git-Internals-Git-References#Remotes).

From within the root of your project, run:

cat .git/refs/remotes/origin/master

Compare the displayed commit ID with:

cat .git/refs/heads/master

They should be the same, and that's why Git says master is up-to-date with origin/master.

When you run

git fetch origin master

That retrieves new Git objects locally under .git/objects folder. And Git updates .git/FETCH_HEAD so that now, it points to the latest commit of the fetched branch.

So to see the differences between your current local branch, and the branch fetched from upstream, you can run

git diff HEAD FETCH_HEAD

Match exact string

Use the start and end delimiters: ^abc$

Remove multiple whitespaces

Without preg_replace()

$str = "This is   a Text \n and so on \t     Text text.";
$str = str_replace(["\r", "\n", "\t"], " ", $str);
while (strpos($str, "  ") !== false)
{
    $str = str_replace("  ", " ", $str);
}
echo $str;

How to make an AJAX call without jQuery?

HTML :

<!DOCTYPE html>
    <html>
    <head>
    <script>
    function loadXMLDoc()
    {
    var xmlhttp;
    if (window.XMLHttpRequest)
      {// code for IE7+, Firefox, Chrome, Opera, Safari
      xmlhttp=new XMLHttpRequest();
      }
    else
      {// code for IE6, IE5
      xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
      }
    xmlhttp.onreadystatechange=function()
      {
      if (xmlhttp.readyState==4 && xmlhttp.status==200)
        {
        document.getElementById("myDiv").innerHTML=xmlhttp.responseText;
        }
      }
    xmlhttp.open("GET","1.php?id=99freebies.blogspot.com",true);
    xmlhttp.send();
    }
    </script>
    </head>
    <body>

    <div id="myDiv"><h2>Let AJAX change this text</h2></div>
    <button type="button" onclick="loadXMLDoc()">Change Content</button>

    </body>
    </html>

PHP:

<?php

$id = $_GET[id];
print "$id";

?>

How to check type of object in Python?

What type() means:

I think your question is a bit more general than I originally thought. type() with one argument returns the type or class of the object. So if you have a = 'abc' and use type(a) this returns str because the variable a is a string. If b = 10, type(b) returns int.

For comparisons:

If you want a comparison you could use: if type(v) == h5py.h5r.Reference (to check if it is a h5py.h5r.Reference instance).

But it is recommended that one uses if isinstance(v, h5py.h5r.Reference) but then also subclasses will evaluate to True.

If you want to print the class use print v.__class__.__name__.

More generally: You can compare if two instances have the same class by using type(v) is type(other_v) or isinstance(v, other_v.__class__).

best way to get the key of a key/value javascript object

A one liner for you:

const OBJECT = {
    'key1': 'value1',
    'key2': 'value2',
    'key3': 'value3',
    'key4': 'value4'
};

const value = 'value2';

const key = Object.keys(OBJECT)[Object.values(OBJECT).indexOf(value)];

window.console.log(key); // = key2

How to deserialize xml to object

Your classes should look like this

[XmlRoot("StepList")]
public class StepList
{
    [XmlElement("Step")]
    public List<Step> Steps { get; set; }
}

public class Step
{
    [XmlElement("Name")]
    public string Name { get; set; }
    [XmlElement("Desc")]
    public string Desc { get; set; }
}

Here is my testcode.

string testData = @"<StepList>
                        <Step>
                            <Name>Name1</Name>
                            <Desc>Desc1</Desc>
                        </Step>
                        <Step>
                            <Name>Name2</Name>
                            <Desc>Desc2</Desc>
                        </Step>
                    </StepList>";

XmlSerializer serializer = new XmlSerializer(typeof(StepList));
using (TextReader reader = new StringReader(testData))
{
    StepList result = (StepList) serializer.Deserialize(reader);
}

If you want to read a text file you should load the file into a FileStream and deserialize this.

using (FileStream fileStream = new FileStream("<PathToYourFile>", FileMode.Open)) 
{
    StepList result = (StepList) serializer.Deserialize(fileStream);
}

Having trouble setting working directory

This may help... use the following code and browse the folder you want to set as the working folder

setwd(choose.dir())

What does the Java assert keyword do, and when should it be used?

In addition to all the great answers provided here, the official Java SE 7 programming guide has a pretty concise manual on using assert; with several spot-on examples of when it's a good (and, importantly, bad) idea to use assertions, and how it's different from throwing exceptions.

Link

How to get coordinates of an svg element?

svg.selectAll("rect")
.attr('x',function(d,i){
    // get x coord
    console.log(this.getBBox().x, 'or', d3.select(this).attr('x'))
})
.attr('y',function(d,i){
    // get y coord
    console.log(this.getBBox().y)
})
.attr('dx',function(d,i){
    // get dx coord
    console.log(parseInt(d3.select(this).attr('dx')))
})

Can we instantiate an abstract class?

Actually we can not create an object of an abstract class directly. What we create is a reference variable of an abstract call. The reference variable is used to Refer to the object of the class which inherits the Abstract class i.e. the subclass of the abstract class.

How can I view an object with an alert()

You should really use Firebug or Webkit's console for debugging. Then you can just do console.debug(product); and examine the object.

fork: retry: Resource temporarily unavailable

Another possibility is too many threads. We just ran into this error message when running a test harness against an app that uses a thread pool. We used

watch -n 5 -d "ps -eL <java_pid> | wc -l"

to watch the ongoing count of Linux native threads running within the given Java process ID. After this hit about 1,000 (for us--YMMV), we started getting the error message you mention.

MySQL ERROR 1045 (28000): Access denied for user 'bill'@'localhost' (using password: YES)

You probably have an anonymous user ''@'localhost' or ''@'127.0.0.1'.

As per the manual:

When multiple matches are possible, the server must determine which of them to use. It resolves this issue as follows: (...)

When a client attempts to connect, the server looks through the rows [of table mysql.user] in sorted order.

The server uses the first row that matches the client host name and user name.

(...) The server uses sorting rules that order rows with the most-specific Host values first. Literal host names [such as 'localhost'] and IP addresses are the most specific.

Hence, such an anonymous user would "mask" any other user like '[any_username]'@'%' when connecting from localhost.

'bill'@'localhost' does match 'bill'@'%', but would match (e.g.) ''@'localhost' beforehands.

The recommended solution is to drop this anonymous user (this is usually a good thing to do anyways).

Below edits are mostly irrelevant to the main question. These are only meant to answer some questions raised in other comments within this thread.

Edit 1

Authenticating as 'bill'@'%' through a socket.


    root@myhost:/home/mysql-5.5.16-linux2.6-x86_64# ./mysql -ubill -ppass --socket=/tmp/mysql-5.5.sock
    Welcome to the MySQL monitor (...)

    mysql> SELECT user, host FROM mysql.user;
    +------+-----------+
    | user | host      |
    +------+-----------+
    | bill | %         |
    | root | 127.0.0.1 |
    | root | ::1       |
    | root | localhost |
    +------+-----------+
    4 rows in set (0.00 sec)

    mysql> SELECT USER(), CURRENT_USER();
    +----------------+----------------+
    | USER()         | CURRENT_USER() |
    +----------------+----------------+
    | bill@localhost | bill@%         |
    +----------------+----------------+
    1 row in set (0.02 sec)

    mysql> SHOW VARIABLES LIKE 'skip_networking';
    +-----------------+-------+
    | Variable_name   | Value |
    +-----------------+-------+
    | skip_networking | ON    |
    +-----------------+-------+
    1 row in set (0.00 sec)

Edit 2

Exact same setup, except I re-activated networking, and I now create an anonymous user ''@'localhost'.


    root@myhost:/home/mysql-5.5.16-linux2.6-x86_64# ./mysql
    Welcome to the MySQL monitor (...)

    mysql> CREATE USER ''@'localhost' IDENTIFIED BY 'anotherpass';
    Query OK, 0 rows affected (0.00 sec)

    mysql> Bye

    root@myhost:/home/mysql-5.5.16-linux2.6-x86_64# ./mysql -ubill -ppass \
        --socket=/tmp/mysql-5.5.sock
    ERROR 1045 (28000): Access denied for user 'bill'@'localhost' (using password: YES)
    root@myhost:/home/mysql-5.5.16-linux2.6-x86_64# ./mysql -ubill -ppass \
        -h127.0.0.1 --protocol=TCP
    ERROR 1045 (28000): Access denied for user 'bill'@'localhost' (using password: YES)
    root@myhost:/home/mysql-5.5.16-linux2.6-x86_64# ./mysql -ubill -ppass \
        -hlocalhost --protocol=TCP
    ERROR 1045 (28000): Access denied for user 'bill'@'localhost' (using password: YES)

Edit 3

Same situation as in edit 2, now providing the anonymous user's password.


    root@myhost:/home/mysql-5.5.16-linux2.6-x86_64# ./mysql -ubill -panotherpass -hlocalhost
    Welcome to the MySQL monitor (...)

    mysql> SELECT USER(), CURRENT_USER();
    +----------------+----------------+
    | USER()         | CURRENT_USER() |
    +----------------+----------------+
    | bill@localhost | @localhost     |
    +----------------+----------------+
    1 row in set (0.01 sec)

Conclusion 1, from edit 1: One can authenticate as 'bill'@'%'through a socket.

Conclusion 2, from edit 2: Whether one connects through TCP or through a socket has no impact on the authentication process (except one cannot connect as anyone else but 'something'@'localhost' through a socket, obviously).

Conclusion 3, from edit 3: Although I specified -ubill, I have been granted access as an anonymous user. This is because of the "sorting rules" advised above. Notice that in most default installations, a no-password, anonymous user exists (and should be secured/removed).

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

If you are on Linux, you just need to fill the OpenCV_DIR variable with the path of opencv (containing the OpenCVConfig.cmake file)

export OpenCV_DIR=<path_of_opencv>

Output grep results to text file, need cleaner output

grep -n "YOUR SEARCH STRING" * > output-file

The -n will print the line number and the > will redirect grep-results to the output-file.
If you want to "clean" the results you can filter them using pipe | for example:
grep -n "test" * | grep -v "mytest" > output-file will match all the lines that have the string "test" except the lines that match the string "mytest" (that's the switch -v) - and will redirect the result to an output file.
A few good grep-tips can be found on this post

Bootstrap: align input with button

I tried all the above codes and none of them fixed my issues. Here is what worked for me. I used input-group-addon.

<div class = "input-group">
  <span class = "input-group-addon">Go</span>
  <input type = "text" class = "form-control" placeholder="you are the man!">
</div>

Jenkins: Cannot define variable in pipeline stage

I think error is not coming from the specified line but from the first 3 lines. Try this instead :

node {
   stage("first") {
     def foo = "foo"
     sh "echo ${foo}"
   }
}

I think you had some extra lines that are not valid...

From declaractive pipeline model documentation, it seems that you have to use an environment declaration block to declare your variables, e.g.:

pipeline {
   environment {
     FOO = "foo"
   }

   agent none
   stages {
       stage("first") {
           sh "echo ${FOO}"
       }
   }
}

How to embed a YouTube channel into a webpage

YouTube supports a fairly easy to use iframe and url interface to embed videos, playlists and all user uploads to your channel: https://developers.google.com/youtube/player_parameters

For example this HTML will embed a player loaded with a playlist of all the videos uploaded to your channel. Replace YOURCHANNELNAME with the actual name of your channel:

<iframe src="http://www.youtube.com/embed/?listType=user_uploads&list=YOURCHANNELNAME" width="480" height="400"></iframe>

Convert JSON to Map

One more alternative is json-simple which can be found in Maven Central:

(JSONObject)JSONValue.parse(someString); //JSONObject is actually a Map.

The artifact is 24kbytes, doesn't have other runtime dependencies.

random.seed(): What does it do?

Here is my understanding. Every time we set a seed value, a "label" or " reference" is generated. The next random.function call is attached to this "label", so next time you call the same seed value and random.function, it will give you the same result.

np.random.seed( 3 )
print(np.random.randn()) # output: 1.7886284734303186

np.random.seed( 3 )
print(np.random.rand()) # different function. output: 0.5507979025745755

np.random.seed( 5 )
print(np.random.rand()) # different seed value. output: 0.22199317108973948

How can I pad a value with leading zeros?

If npm is available in your environment some of ready-made packages can be used: www.npmjs.com/browse/keyword/zeropad.

I like zero-fill.

Installation

$ npm install zero-fill

Usage

var zeroFill = require('zero-fill')

zeroFill(4, 1)      // '0001' 
zeroFill(4, 1, '#') // '###1' custom padding
zeroFill(4)(1)      // '0001' partials

regex to remove all text before a character

no need to do a replacement. the regex will give you what u wanted directly:

"(?<=_)[^_]*\.jpg"

tested with grep:

 echo "3.04_somename.jpg"|grep -oP "(?<=_)[^_]*\.jpg"
somename.jpg

How to add default value for html <textarea>?

You can also add the "value" attribute and set that so something like so:


<textarea value="your value"> </textarea>

Make button width fit to the text

Keeping the element's size relative to its content can also be done with display: inline-flex and display: table

The centering can be done with..

text-align: center; on the parent (or above, it's inherited)
display: flex; and justify-content: center; on the parent
position: absolute; left: 50%; transform: translateX(-50%); on the element with position: relative; (at least) on the parent.

Here's a flexbox guide from CSS Tricks

Here's an article on centering from CSS Tricks.

Keeping an element only as wide as its content..

Can use display: table;
Or inline-anything including inline-flex as used in my snippet example below.

Keep in mind that when centering with flexbox's justify-content: center; when the text wraps the text will align left. So you will still need text-align: center; if your site is responsive and you expect lines to wrap.

More examples in this stack answer

_x000D_

body {_x000D_
  display: flex;_x000D_
  flex-direction: column;_x000D_
  height: 100vh;_x000D_
  padding: 20px;_x000D_
}_x000D_
.container {_x000D_
  display: flex;_x000D_
  justify-content: center; /* center horizontally */_x000D_
  align-items: center; /* center vertically */_x000D_
  height: 50%;_x000D_
}_x000D_
.container.c1 {_x000D_
  text-align: center; /* needed if the text wraps */_x000D_
  /* text-align is inherited, it can be put on the parent or the target element */_x000D_
}_x000D_
.container.c2 {_x000D_
 /* without text-align: center; */_x000D_
}_x000D_
.button {_x000D_
  padding: 5px 10px;_x000D_
  font-size: 30px;_x000D_
  text-decoration: none;_x000D_
  color: hsla(0, 0%, 90%, 1);_x000D_
  background: linear-gradient(hsla(21, 85%, 51%, 1), hsla(21, 85%, 61%, 1));_x000D_
  border-radius: 10px;_x000D_
  box-shadow: 2px 2px 15px -5px hsla(0, 0%, 0%, 1);_x000D_
}_x000D_
.button:hover {_x000D_
  background: linear-gradient(hsl(207.5, 84.8%, 51%), hsla(207, 84%, 62%, 1));_x000D_
  transition: all 0.2s linear;_x000D_
}_x000D_
.button.b1 {_x000D_
    display: inline-flex; /* element only as wide as content */_x000D_
}_x000D_
.button.b2 {_x000D_
    display: table; /* element only as wide as content */_x000D_
}

_x000D_

<div class="container c1">_x000D_
  <a class="button b1" href="https://stackoverflow.com/questions/27722872/">This Text Is Centered Before And After Wrap</a>_x000D_
</div>_x000D_
<div class="container c2">_x000D_
  <a class="button b2" href="https://stackoverflow.com/questions/27722872/">This Text Is Centered Only Before Wrap</a>_x000D_
</div>

_x000D_

Fiddle

https://jsfiddle.net/Hastig/02fbs3pv/

Insert image after each list item

I think your problem is that the :after psuedo-element requires the content: property set inside it. You need to tell it to insert something. You could even just have it insert the image directly:

ul li:after {
    content: url('../images/small_triangle.png');
}

Rounding a double to turn it into an int (java)

If you don't like Math.round() you can use this simple approach as well:

int a = (int) (doubleVar + 0.5);

Checking for directory and file write permissions in .NET

Directory.GetAccessControl(path) does what you are asking for.

public static bool HasWritePermissionOnDir(string path)
{
    var writeAllow = false;
    var writeDeny = false;
    var accessControlList = Directory.GetAccessControl(path);
    if (accessControlList == null)
        return false;
    var accessRules = accessControlList.GetAccessRules(true, true, 
                                typeof(System.Security.Principal.SecurityIdentifier));
    if (accessRules ==null)
        return false;

    foreach (FileSystemAccessRule rule in accessRules)
    {
        if ((FileSystemRights.Write & rule.FileSystemRights) != FileSystemRights.Write) 
            continue;

        if (rule.AccessControlType == AccessControlType.Allow)
            writeAllow = true;
        else if (rule.AccessControlType == AccessControlType.Deny)
            writeDeny = true;
    }

    return writeAllow && !writeDeny;
}

(FileSystemRights.Write & rights) == FileSystemRights.Write is using something called "Flags" btw which if you don't know what it is you should really read up on :)

What is the PostgreSQL equivalent for ISNULL()

SELECT CASE WHEN field IS NULL THEN 'Empty' ELSE field END AS field_alias

Or more idiomatic:

SELECT coalesce(field, 'Empty') AS field_alias

How can I install a local gem?

Yup, when you do gem install, it will search the current directory first, so if your .gem file is there, it will pick it up. I found it on the gem reference, which you may find handy as well:

gem install will install the named gem. It will attempt a local installation (i.e. a .gem file in the current directory), and if that fails, it will attempt to download and install the most recent version of the gem you want.

Round a divided number in Bash

If the decimal separator is comma (eg : LC_NUMERIC=fr_FR.UTF-8, see here):

$ printf "%.0f" $(echo "scale=2;3/2" | bc) 
bash: printf: 1.50: nombre non valable
0

Substitution is needed for ghostdog74 solution :

$ printf "%.0f" $(echo "scale=2;3/2" | bc | sed 's/[.]/,/')
2

$ printf "%.0f" $(echo "scale=2;3/2" | bc | tr '.' ',')
2

One-liner if statements, how to convert this if-else-statement

All you'd need in your case is:

return expression;

The reason why is that the expression itself evaluates to a boolean value of true or false, so it's redundant to have an if block (or even a ?: operator).

How to convert number to words in java

I tried to make the code more readable. This works for numbers within integer range

import java.util.HashMap;
import java.util.LinkedList;
import java.util.Map;
import java.util.Scanner;

public class Solution2 {

    static Map<Integer, String> numberMap = new HashMap<Integer, String>();
    static Map<Integer, String> tensMap = new HashMap<Integer, String>();
    static Map<Integer, String> exponentsMap = new HashMap<Integer, String>();
    
    public static void main(String[] args) {

        LinkedList<String> wordList = new LinkedList<String>();
        Scanner scan = new Scanner(System.in);
        int input = scan.nextInt();
        scan.close();

        exponentsMap.put(3, "thousand");
        exponentsMap.put(6, "million");
        exponentsMap.put(9, "billion");

        tensMap.put(2, "twenty");
        tensMap.put(3, "thirty");
        tensMap.put(4, "forty");
        tensMap.put(5, "fifty");
        tensMap.put(6, "sixty");
        tensMap.put(7, "seventy");
        tensMap.put(8, "eighty");
        tensMap.put(9, "ninety");

        numberMap.put(1, "one");
        numberMap.put(2, "two");
        numberMap.put(3, "three");
        numberMap.put(4, "four");
        numberMap.put(5, "five");
        numberMap.put(6, "six");
        numberMap.put(7, "seven");
        numberMap.put(8, "eight");
        numberMap.put(9, "nine");
        numberMap.put(10, "ten");
        numberMap.put(11, "eleven");
        numberMap.put(12, "twelve");
        numberMap.put(13, "thirteen");
        numberMap.put(14, "fourteen");
        numberMap.put(15, "fifteen");
        numberMap.put(16, "sixteen");
        numberMap.put(17, "seventeen");
        numberMap.put(18, "eighteen");
        numberMap.put(19, "nineteen");

        int temp = input;
        
        int exponentCounter =0;
        while(temp>0) {
            // words from 1 to 99
            addLastTwo(temp%100,wordList);
            temp=temp/100;
            
            // add hundreds before exponents
            if(temp!=0) {
                wordList.addFirst("hundred");
                wordList.addFirst(numberMap.getOrDefault(temp%10,""));
                temp = temp/10;
            }
            
            // words for exponents
            if(temp!=0) {
                exponentCounter+=3;
                wordList.addFirst(exponentsMap.getOrDefault(exponentCounter,""));
            }
        }
        wordList.stream().filter(word -> !word.contentEquals("")).forEach(word -> System.out.print(word + " "));
    }

    private static void addLastTwo(int num, LinkedList<String> wordList) {
        if (num > 19) {
            wordList.addFirst(numberMap.getOrDefault(num % 10,""));
            wordList.addFirst(tensMap.getOrDefault(num / 10,""));
            
        } else {
            wordList.addFirst(numberMap.getOrDefault(num,""));
        }
    }
}

How do I use method overloading in Python?

You can also use pythonlangutil:

from pythonlangutil.overload import Overload, signature

class A:
    @Overload
    @signature()
    def stackoverflow(self):    
        print 'first method'

    @stackoverflow.overload
    @signature("int")
    def stackoverflow(self, i):
        print 'second method', i

How to solve SyntaxError on autogenerated manage.py?

The error is generated by using a later version of Django with an old python, probably of version 2.x.

To fix this I had to delete the .venv folder and recreate it with virtualenv -p python3 .venv && source .venv/bin/activate

Java ArrayList - how can I tell if two lists are equal, order not mattering?

If the cardinality of items doesn't matter (meaning: repeated elements are considered as one), then there is a way to do this without having to sort:

boolean result = new HashSet<>(listA).equals(new HashSet<>(listB));

This will create a Set out of each List, and then use HashSet's equals method which (of course) disregards ordering.

If cardinality matters, then you must confine yourself to facilities provided by List; @jschoen's answer would be more fitting in that case.

Why am I getting "Thread was being aborted" in ASP.NET?

This problem occurs in the Response.Redirect and Server.Transfer methods, because both methods call Response.End internally.

The solution for this problem is as follows.

For Server.Transfer, use the Server.Execute method instead.

Visit this link for download an example.

Image resizing in React Native

{ flex: 1, resizeMode: 'contain' } worked for me. I didn't need the aspectRatio

'LIKE ('%this%' OR '%that%') and something=else' not working

Have you tried:

(column LIKE '%this%' and something=else) or (column LIKE '%that%' and something=else)

Java Multithreading concept and join() method

First rule of threading - "Threading is fun"...

I'm not able to understand the flow of execution of the program, And when ob1 is created then the constructor is called where t.start() is written but still run() method is not executed rather main() method continues execution. So why is this happening?

This is exactly what should happen. When you call Thread#start, the thread is created and schedule for execution, it might happen immediately (or close enough to it), it might not. It comes down to the thread scheduler.

This comes down to how the thread execution is scheduled and what else is going on in the system. Typically, each thread will be given a small amount of time to execute before it is put back to "sleep" and another thread is allowed to execute (obviously in multiple processor environments, more than one thread can be running at time, but let's try and keep it simple ;))

Threads may also yield execution, allow other threads in the system to have chance to execute.

You could try

NewThread(String threadname) {
    name = threadname;
    t = new Thread(this, name);
    System.out.println("New thread: " + t);
    t.start(); // Start the thread
    // Yield here
    Thread.yield();
}

And it might make a difference to the way the threads run...equally, you could sleep for a small period of time, but this could cause your thread to be overlooked for execution for a period of cycles (sometimes you want this, sometimes you don't)...

join() method is used to wait until the thread on which it is called does not terminates, but here in output we see alternate outputs of the thread why??

The way you've stated the question is wrong...join will wait for the Thread it is called on to die before returning. For example, if you depending on the result of a Thread, you could use join to know when the Thread has ended before trying to retrieve it's result.

Equally, you could poll the thread, but this will eat CPU cycles that could be better used by the Thread instead...

Load view from an external xib file in storyboard

My full example is here, but I will provide a summary below.

Layout

Add a .swift and .xib file each with the same name to your project. The .xib file contains your custom view layout (using auto layout constraints preferably).

Make the swift file the xib file's owner.

Code

Add the following code to the .swift file and hook up the outlets and actions from the .xib file.

import UIKit
class ResuableCustomView: UIView {

    let nibName = "ReusableCustomView"
    var contentView: UIView?

    @IBOutlet weak var label: UILabel!
    @IBAction func buttonTap(_ sender: UIButton) {
        label.text = "Hi"
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

        guard let view = loadViewFromNib() else { return }
        view.frame = self.bounds
        self.addSubview(view)
        contentView = view
    }

    func loadViewFromNib() -> UIView? {
        let bundle = Bundle(for: type(of: self))
        let nib = UINib(nibName: nibName, bundle: bundle)
        return nib.instantiate(withOwner: self, options: nil).first as? UIView
    }
}

Use it

Use your custom view anywhere in your storyboard. Just add a UIView and set the class name to your custom class name.

For a while Christopher Swasey's approach was the best approach I had found. I asked a couple of the senior devs on my team about it and one of them had the perfect solution! It satisfies every one of the concerns that Christopher Swasey so eloquently addressed and it doesn't require boilerplate subclass code(my main concern with his approach). There is one gotcha, but other than that it is fairly intuitive and easy to implement.

Create a custom UIView class in a .swift file to control your xib. i.e. MyCustomClass.swift
Create a .xib file and style it as you want. i.e. MyCustomClass.xib
Set the File's Owner of the .xib file to be your custom class (MyCustomClass)
GOTCHA: leave the class value (under the identity Inspector) for your custom view in the .xib file blank. So your custom view will have no specified class, but it will have a specified File's Owner.
Hook up your outlets as you normally would using the Assistant Editor.
- NOTE: If you look at the Connections Inspector you will notice that your Referencing Outlets do not reference your custom class (i.e. MyCustomClass), but rather reference File's Owner. Since File's Owner is specified to be your custom class, the outlets will hook up and work propery.
Make sure your custom class has @IBDesignable before the class statement.
Make your custom class conform to the NibLoadable protocol referenced below.
- NOTE: If your custom class .swift file name is different from your .xib file name, then set the nibName property to be the name of your .xib file.
Implement required init?(coder aDecoder: NSCoder) and override init(frame: CGRect) to call setupFromNib() like the example below.
Add a UIView to your desired storyboard and set the class to be your custom class name (i.e. MyCustomClass).
Watch IBDesignable in action as it draws your .xib in the storyboard with all of it's awe and wonder.

Here is the protocol you will want to reference:

public protocol NibLoadable {
    static var nibName: String { get }
}

public extension NibLoadable where Self: UIView {

    public static var nibName: String {
        return String(describing: Self.self) // defaults to the name of the class implementing this protocol.
    }

    public static var nib: UINib {
        let bundle = Bundle(for: Self.self)
        return UINib(nibName: Self.nibName, bundle: bundle)
    }

    func setupFromNib() {
        guard let view = Self.nib.instantiate(withOwner: self, options: nil).first as? UIView else { fatalError("Error loading \(self) from nib") }
        addSubview(view)
        view.translatesAutoresizingMaskIntoConstraints = false
        view.leadingAnchor.constraint(equalTo: self.safeAreaLayoutGuide.leadingAnchor, constant: 0).isActive = true
        view.topAnchor.constraint(equalTo: self.safeAreaLayoutGuide.topAnchor, constant: 0).isActive = true
        view.trailingAnchor.constraint(equalTo: self.safeAreaLayoutGuide.trailingAnchor, constant: 0).isActive = true
        view.bottomAnchor.constraint(equalTo: self.safeAreaLayoutGuide.bottomAnchor, constant: 0).isActive = true
    }
}

And here is an example of MyCustomClass that implements the protocol (with the .xib file being named MyCustomClass.xib):

@IBDesignable
class MyCustomClass: UIView, NibLoadable {

    @IBOutlet weak var myLabel: UILabel!

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setupFromNib()
    }

    override init(frame: CGRect) {
        super.init(frame: frame)
        setupFromNib()
    }

}

NOTE: If you miss the Gotcha and set the class value inside your .xib file to be your custom class, then it will not draw in the storyboard and you will get a EXC_BAD_ACCESS error when you run the app because it gets stuck in an infinite loop of trying to initialize the class from the nib using the init?(coder aDecoder: NSCoder) method which then calls Self.nib.instantiate and calls the init again.

How to get a microtime in Node.js?

The BigInt data type is supported since Node.js 10.7.0. (see also the blog post announcement). For these supported versions of Node.js, the process.hrtime([time]) method is now regarded as 'legacy', replaced by the process.hrtime.bigint() method.

The bigint version of the process.hrtime() method returning the current high-resolution real time in a bigint.

const start = process.hrtime.bigint();
// 191051479007711n

setTimeout(() => {
  const end = process.hrtime.bigint();
  // 191052633396993n

  console.log(`Benchmark took ${end - start} nanoseconds`);
  // Benchmark took 1154389282 nanoseconds
}, 1000);

tl;dr

Node.js 10.7.0+ - Use process.hrtime.bigint()
Otherwise - Use process.hrtime()

In C#, what's the difference between \n and \r\n?

"\n" is just a line feed (Unicode U+000A). This is typically the Unix line separator.

"\r\n" is a carriage return (Unicode U+000D) followed by a line feed (Unicode U+000A). This is typically the Windows line separator.

How to fix C++ error: expected unqualified-id

For anyone with this situation: I saw this error when I accidentally used my_first_scope::my_second_scope::true in place of simply true, like this:

bool my_var = my_first_scope::my_second_scope::true;

instead of:

bool my_var = true;

This is because I had a macro which caused MY_MACRO(true) to expand into my_first_scope::my_second_scope::true, by mistake, and I was actually calling bool my_var = MY_MACRO(true);.

Here's a quick demo of this type of scoping error:

Program (you can run it online here: https://onlinegdb.com/BkhFBoqUw):

#include <iostream>
#include <cstdio>

namespace my_first_scope 
{
namespace my_second_scope
{
} // namespace my_second_scope
} // namespace my_first_scope

int main()
{
    printf("Hello World\n");
    
    bool my_var = my_first_scope::my_second_scope::true;
    
    std::cout << my_var << std::endl;

    return 0;
}

Output (build error):

main.cpp: In function ‘int main()’:
main.cpp:27:52: error: expected unqualified-id before ‘true’
     bool my_var = my_first_scope::my_second_scope::true;
                                                    ^~~~

Notice the error: error: expected unqualified-id before ‘true’, and where the arrow under the error is pointing. Apparently the "unqualified-id" in my case is the double colon (::) scope operator I have just before true.

When I add in the macro and use it (run this new code here: https://onlinegdb.com/H1eevs58D):

#define MY_MACRO(input) my_first_scope::my_second_scope::input

...

bool my_var = MY_MACRO(true);

I get this new error instead:

main.cpp: In function ‘int main()’:
main.cpp:29:28: error: expected unqualified-id before ‘true’
     bool my_var = MY_MACRO(true);
                            ^
main.cpp:16:58: note: in definition of macro ‘MY_MACRO’
 #define MY_MACRO(input) my_first_scope::my_second_scope::input
                                                          ^~~~~

Finding all possible combinations of numbers to reach a given sum

Linux command: How to 'find' only text files?

How about this:

$ grep -rl "needle text" my_folder | tr '\n' '\0' | xargs -r -0 file | grep -e ':[^:]*text[^:]*$' | grep -v -e 'executable'

If you want the filenames without the file types, just add a final sed filter.

$ grep -rl "needle text" my_folder | tr '\n' '\0' | xargs -r -0 file | grep -e ':[^:]*text[^:]*$' | grep -v -e 'executable' | sed 's|:[^:]*$||'

You can filter-out unneeded file types by adding more -e 'type' options to the last grep command.

EDIT:

If your xargs version supports the -d option, the commands above become simpler:

$ grep -rl "needle text" my_folder | xargs -d '\n' -r file | grep -e ':[^:]*text[^:]*$' | grep -v -e 'executable' | sed 's|:[^:]*$||'

"Connection for controluser as defined in your configuration failed" with phpMyAdmin in XAMPP

I just simply make changes on config.inc.php file. There is password in error in this link $cfg['Servers'][$i]['password'] = 'your password '; and now its perfectly worked .

Why does typeof array with objects return "object" and not "array"?

One of the weird behaviour and spec in Javascript is the typeof Array is Object.

You can check if the variable is an array in couple of ways:

var isArr = data instanceof Array;
var isArr = Array.isArray(data);

But the most reliable way is:

isArr = Object.prototype.toString.call(data) == '[object Array]';

Since you tagged your question with jQuery, you can use jQuery isArray function:

var isArr = $.isArray(data);

How to pass variables from one php page to another without form?

check to make sure the variable is set. Then clean it before using it:

isset($_GET['var'])?$var=mysql_escape_string($_GET['var']):$var='SomeDefaualtValue';

Otherwise, assign it a default value ($var='' is fine) to avoid the error you mentioned.

<img>: Unsafe value used in a resource URL context

import {DomSanitizationService} from '@angular/platform-browser';
@Component({
 templateUrl: 'build/pages/veeu/veeu.html'
 })
  export class VeeUPage {
     trustedURL:any;
      static get parameters() {
               return [NavController, App, MenuController, 
              DomSanitizationService];
        }
      constructor(nav, app, menu, sanitizer) {
        this.app = app;
        this.nav = nav;
        this.menu = menu;
        this.sanitizer = sanitizer;  
        this.trustedURL  = sanitizer.bypassSecurityTrustUrl(this.mediaItems[1].url);
        } 
 }



 <iframe [src]='trustedURL' width="640" height="360" frameborder="0"
   webkitallowfullscreen mozallowfullscreen allowfullscreen>
</iframe>


User property binding instead of function.

What do I use on linux to make a python program executable

I do the following:

put #! /usr/bin/env python3 at top of script
chmod u+x file.py
Change .py to .command in file name

This essentially turns the file into a bash executable. When you double-click it, it should run. This works in Unix-based systems.

String index out of range: 4

You are using the wrong iteration counter, replace inp.charAt(i) with inp.charAt(j).

No serializer found for class org.hibernate.proxy.pojo.javassist.Javassist?

In the Hibernate 5.2 and above, you able to remove the hibernate proxy as below, it will give you the actual object so you can serialize it properly:

Object unproxiedEntity = Hibernate.unproxy( proxy );

How to increase an array's length

Item[] newItemList = new  Item[itemList.length+1];
    //for loop to go thorough the list one by one
    for(int i=0; i< itemList.length;i++){
        //value is stored here in the new list from the old one
        newItemList[i]=itemList[i];
    }
    //all the values of the itemLists are stored in a bigger array named newItemList
    itemList=newItemList;

How to quit a java app from within the program

You can use System.exit() for this purpose.

According to oracle's Java 8 documentation:

public static void exit(int status)

Terminates the currently running Java Virtual Machine. The argument serves as a status code; by convention, a nonzero status code indicates abnormal termination.

This method calls the exit method in class Runtime. This method never returns normally.

The call System.exit(n) is effectively equivalent to the call:

Runtime.getRuntime().exit(n)

How to put a div in center of browser using CSS?

<html>
<head>
<style>
*
{
    margin:0;
    padding:0;
}

html, body
{
    height:100%;
}

#distance
{
    width:1px;
    height:50%;
    margin-bottom:-300px;
    float:left;
}


#something
{
    position:relative;
    margin:0 auto;
    text-align:left;
    clear:left;
    width:800px;
    min-height:600px;
    height:auto;
    border: solid 1px #993333;
    z-index: 0;
}

/* for Internet Explorer */
* html #something{
height: 600px;
}
</style>

</head>
<body>

<div id="distance"></div>

<div id="something">
</div>
</body>

</html>

Tested in FF2-3, IE6-7, Opera and works well!

Invalid CSRF Token 'null' was found on the request parameter '_csrf' or header 'X-CSRF-TOKEN'

Shouldn't you add to the login form?;

<input type="hidden" name="${_csrf.parameterName}" value="${_csrf.token}"/>

As stated in the here in the Spring security documentation

Removing multiple classes (jQuery)

You must be separate those classes which you want to remove by white space$('selector').removeClass('class1 class2');

Do you have to put Task.Run in a method to make it async?

When you use Task.Run to run a method, Task gets a thread from threadpool to run that method. So from the UI thread's perspective, it is "asynchronous" as it doesn't block UI thread.This is fine for desktop application as you usually don't need many threads to take care of user interactions.

However, for web application each request is serviced by a thread-pool thread and thus the number of active requests can be increased by saving such threads. Frequently using threadpool threads to simulate async operation is not scalable for web applications.

True Async doesn't necessarily involving using a thread for I/O operations, such as file / DB access etc. You can read this to understand why I/O operation doesn't need threads. http://blog.stephencleary.com/2013/11/there-is-no-thread.html

In your simple example,it is a pure CPU-bound calculation, so using Task.Run is fine.

failed to load ad : 3

This works for me

Settings->Google->Ads->Reset advertising ID->OK

But In some cases, ads are automatically come after uploaded to the play store.

javax.naming.NameNotFoundException

The error means that your are trying to look up JNDI name, that is not attached to any EJB component - the component with that name does not exist.

As far as dir structure is concerned: you have to create a JAR file with EJB components. As I understand you want to play with EJB 2.X components (at least the linked example suggests that) so the structure of the JAR file should be:

/com/mypackage/MyEJB.class /com/mypackage/MyEJBInterface.class /com/mypackage/etc... etc... java classes /META-INF/ejb-jar.xml /META-INF/jboss.xml

The JAR file is more or less ZIP file with file extension changed from ZIP to JAR.

BTW. If you use JBoss 5, you can work with EJB 3.0, which are much more easier to configure. The simplest component is

@Stateless(mappedName="MyComponentName")
@Remote(MyEJBInterface.class)
public class MyEJB implements MyEJBInterface{
   public void bussinesMethod(){

   }
}

No ejb-jar.xml, jboss.xml is needed, just EJB JAR with MyEJB and MyEJBInterface compiled classes.

Now in your client code you need to lookup "MyComponentName".

Test for array of string type in TypeScript

You can have do it easily using Array.prototype.some() as below.

const isStringArray = (test: any[]): boolean => {
 return Array.isArray(test) && !test.some((value) => typeof value !== 'string')
}
const myArray = ["A", "B", "C"]
console.log(isStringArray(myArray)) // will be log true if string array

I believe this approach is better that others. That is why I am posting this answer.

Update on Sebastian Vittersø's comment

Here you can use Array.prototype.every() as well.

const isStringArray = (test: any[]): boolean => {
 return Array.isArray(test) && test.every((value) => typeof value === 'string')
}

Calculating Pearson correlation and significance in Python

I have a very simple and easy to understand solution for this. For two arrays of equal length, Pearson coefficient can be easily computed as follows:

def manual_pearson(a,b):
"""
Accepts two arrays of equal length, and computes correlation coefficient. 
Numerator is the sum of product of (a - a_avg) and (b - b_avg), 
while denominator is the product of a_std and b_std multiplied by 
length of array. 
"""
  a_avg, b_avg = np.average(a), np.average(b)
  a_stdev, b_stdev = np.std(a), np.std(b)
  n = len(a)
  denominator = a_stdev * b_stdev * n
  numerator = np.sum(np.multiply(a-a_avg, b-b_avg))
  p_coef = numerator/denominator
  return p_coef

Unicode, UTF, ASCII, ANSI format differences

Some reading to get you started on character encodings: Joel on Software: The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!)

By the way - ASP.NET has nothing to do with it. Encodings are universal.

Print Currency Number Format in PHP

PHP has a function called money_format for doing this. Read about this here.

Get encoding of a file in Windows

Open up your file using regular old vanilla Notepad that comes with Windows.
It will show you the encoding of the file when you click "Save As...".
It'll look like this: enter image description here

Whatever the default-selected encoding is, that is what your current encoding is for the file.
If it is UTF-8, you can change it to ANSI and click save to change the encoding (or visa-versa).

I realize there are many different types of encoding, but this was all I needed when I was informed our export files were in UTF-8 and they required ANSI. It was a onetime export, so Notepad fit the bill for me.

FYI: From my understanding I think "Unicode" (as listed in Notepad) is a misnomer for UTF-16.
More here on Notepad's "Unicode" option: Windows 7 - UTF-8 and Unicdoe

Can someone explain how to append an element to an array in C programming?

You can have a counter (freePosition), which will track the next free place in an array of size n.

Git merge with force overwrite

I had a similar issue, where I needed to effectively replace any file that had changes / conflicts with a different branch.

The solution I found was to use git merge -s ours branch.

Note that the option is -s and not -X. -s denotes the use of ours as a top level merge strategy, -X would be applying the ours option to the recursive merge strategy, which is not what I (or we) want in this case.

Steps, where oldbranch is the branch you want to overwrite with newbranch.

git checkout newbranch checks out the branch you want to keep
git merge -s ours oldbranch merges in the old branch, but keeps all of our files.
git checkout oldbranch checks out the branch that you want to overwrite
get merge newbranch merges in the new branch, overwriting the old branch

How to window.scrollTo() with a smooth effect

$('html, body').animate({scrollTop:1200},'50');

You can do this!

How to get the fields in an Object via reflection?

Here's a quick and dirty method that does what you want in a generic way. You'll need to add exception handling and you'll probably want to cache the BeanInfo types in a weakhashmap.

public Map<String, Object> getNonNullProperties(final Object thingy) {
    final Map<String, Object> nonNullProperties = new TreeMap<String, Object>();
    try {
        final BeanInfo beanInfo = Introspector.getBeanInfo(thingy
                .getClass());
        for (final PropertyDescriptor descriptor : beanInfo
                .getPropertyDescriptors()) {
            try {
                final Object propertyValue = descriptor.getReadMethod()
                        .invoke(thingy);
                if (propertyValue != null) {
                    nonNullProperties.put(descriptor.getName(),
                            propertyValue);
                }
            } catch (final IllegalArgumentException e) {
                // handle this please
            } catch (final IllegalAccessException e) {
                // and this also
            } catch (final InvocationTargetException e) {
                // and this, too
            }
        }
    } catch (final IntrospectionException e) {
        // do something sensible here
    }
    return nonNullProperties;
}

See these references:

BeanInfo (JavaDoc)
Introspector.getBeanInfo(class) (JavaDoc)
Introspection (Sun Java Tutorial)

Cannot import keras after installation

I had pip referring by default to pip3, which made me download the libs for python3. On the contrary I launched the shell as python (which opened python 2) and the library wasn't installed there obviously.

Once I matched the names pip3 -> python3, pip -> python (2) all worked.

Confirmation dialog on ng-click - AngularJS

Delete confirmation popup using bootstrap in angularjs

very simple.. I have one solution for this with using bootstrap conformation popup. Here i am provided

<button ng-click="deletepopup($index)">Delete</button>

in bootstrap model popup:

<div class="modal-footer">
  <a href="" data-dismiss="modal" ng-click="deleteData()">Yes</a>
  <a href="" data-dismiss="modal">No</a>
</div>

var index=0;
$scope.deleteData=function(){
    $scope.model.contacts.splice(index,1);
}
// delete a row 
$scope.deletepopup = function ($index) {
    index=$index;
    $('#myModal').modal('show');
};

when i click delete button bootstrap delete conformation popup will open and when i click yes button row will deleted.

how to check if the input is a number or not in C?

Using fairly simple code:

int i;
int value;
int n;
char ch;

/* Skip i==0 because that will be the program name */
for (i=1; i<argc; i++) {
    n = sscanf(argv[i], "%d%c", &value, &ch);

    if (n != 1) {
        /* sscanf didn't find a number to convert, so it wasn't a number */
    }
    else {
        /* It was */
    }
}

NameError: global name 'xrange' is not defined in Python 3

I agree with the last answer.But there is another way to solve this problem.You can download the package named future,such as pip install future.And in your .py file input this "from past.builtins import xrange".This method is for the situation that there are many xranges in your file.

Best way to parseDouble with comma as decimal separator?

You of course need to use the correct locale. This question will help.

Convert object of any type to JObject with Json.NET

JObject implements IDictionary, so you can use it that way. For ex,

var cycleJson  = JObject.Parse(@"{""name"":""john""}");

//add surname
cycleJson["surname"] = "doe";

//add a complex object
cycleJson["complexObj"] = JObject.FromObject(new { id = 1, name = "test" });

So the final json will be

{
  "name": "john",
  "surname": "doe",
  "complexObj": {
    "id": 1,
    "name": "test"
  }
}

You can also use dynamic keyword

dynamic cycleJson  = JObject.Parse(@"{""name"":""john""}");
cycleJson.surname = "doe";
cycleJson.complexObj = JObject.FromObject(new { id = 1, name = "test" });

mysql datetime comparison

I know its pretty old but I just encounter the problem and there is what I saw in the SQL doc :

[For best results when using BETWEEN with date or time values,] use CAST() to explicitly convert the values to the desired data type. Examples: If you compare a DATETIME to two DATE values, convert the DATE values to DATETIME values. If you use a string constant such as '2001-1-1' in a comparison to a DATE, cast the string to a DATE.

I assume it's better to use STR_TO_DATE since they took the time to make a function just for that and also the fact that i found this in the BETWEEN doc...

org.json.simple cannot be resolved

Probably your simple json.jar file isn't in your classpath.

Cannot connect to the Docker daemon on macOS

on OSX assure you have launched the Docker application before issuing

docker ps

or docker build ... etc ... yes it seems strange and somewhat misleading that issuing

docker --version

gives version even though the docker daemon is not running ... ditto for those other version cmds ... I just encountered exactly the same symptoms ... this behavior on OSX is different from on linux

Change size of axes title and labels in ggplot2

To change the size of (almost) all text elements, in one place, and synchronously, rel() is quite efficient:
g+theme(text = element_text(size=rel(3.5))

You might want to tweak the number a bit, to get the optimum result. It sets both the horizontal and vertical axis labels and titles, and other text elements, on the same scale. One exception is faceted grids' titles which must be manually set to the same value, for example if both x and y facets are used in a graph:
theme(text = element_text(size=rel(3.5)), strip.text.x = element_text(size=rel(3.5)), strip.text.y = element_text(size=rel(3.5)))

How to use Git Revert

Use git revert like so:

git revert <insert bad commit hash here>

git revert creates a new commit with the changes that are rolled back. git reset erases your git history instead of making a new commit.

The steps after are the same as any other commit.

what is .subscribe in angular?

In Angular (currently on Angular-6) .subscribe() is a method on the Observable type. The Observable type is a utility that asynchronously or synchronously streams data to a variety of components or services that have subscribed to the observable.

The observable is an implementation/abstraction over the promise chain and will be a part of ES7 as a proposed and very supported feature. In Angular it is used internally due to rxjs being a development dependency.

An observable itself can be thought of as a stream of data coming from a source, in Angular this source is an API-endpoint, a service, a database or another observable. But the power it has is that it's not expecting a single response. It can have one or many values that are returned.

Link to rxjs for observable/subscribe docs here: https://rxjs-dev.firebaseapp.com/api/index/class/Observable#subscribe-

Subscribe takes 3 methods as parameters each are functions:

next: For each item being emitted by the observable perform this function
error: If somewhere in the stream an error is found, do this method
complete: Once all items are complete from the stream, do this method

Within each of these, there is the potentional to pipe (or chain) other utilities called operators onto the results to change the form or perform some layered logic.

In the simple example above:

.subscribe(hero => this.hero = hero); basically says on this observable take the hero being emitted and set it to this.hero.

Adding this answer to give more context to Observables based off the documentation and my understanding.

How to expand a list to function arguments in Python

You should use the * operator, like foo(*values) Read the Python doc unpackaging argument lists.

Also, do read this: http://www.saltycrane.com/blog/2008/01/how-to-use-args-and-kwargs-in-python/

def foo(x,y,z):
   return "%d, %d, %d" % (x,y,z)

values = [1,2,3]

# the solution.
foo(*values)

Switch: Multiple values in one case?

Separate the business rules for age from the actions e.g. (NB just typed, not checked)

enum eAgerange { eChild, eYouth, eAdult, eAncient};
eAgeRange ar;
if(age <= 8) ar = eChild;
else if(age <= 15) ar = eYouth;
else if(age <= 100) ar = eAdult;
else ar = eAncient;
switch(ar)
{
 case eChild: 
     // action
 case eYouth:
     // action
 case eAdult:
     // action
 case eAncient:
     // action
 default: throw new NotImplementedException($"Oops {ar.ToString()} not handled");
}

Salt and hash a password in Python

Based on the other answers to this question, I've implemented a new approach using bcrypt.

Why use bcrypt

If I understand correctly, the argument to use bcrypt over SHA512 is that bcrypt is designed to be slow. bcrypt also has an option to adjust how slow you want it to be when generating the hashed password for the first time:

# The '12' is the number that dictates the 'slowness'
bcrypt.hashpw(password, bcrypt.gensalt( 12 ))

Slow is desirable because if a malicious party gets their hands on the table containing hashed passwords, then it is much more difficult to brute force them.

Implementation

def get_hashed_password(plain_text_password):
    # Hash a password for the first time
    #   (Using bcrypt, the salt is saved into the hash itself)
    return bcrypt.hashpw(plain_text_password, bcrypt.gensalt())

def check_password(plain_text_password, hashed_password):
    # Check hashed password. Using bcrypt, the salt is saved into the hash itself
    return bcrypt.checkpw(plain_text_password, hashed_password)

Notes

I was able to install the library pretty easily in a linux system using:

pip install py-bcrypt

However, I had more trouble installing it on my windows systems. It appears to need a patch. See this Stack Overflow question: py-bcrypt installing on win 7 64bit python

Converting PHP result array to JSON

json_encode is available in php > 5.2.0:

echojson_encode($row);

Typescript: How to define type for a function callback (as any function type, not universal any) used in a method parameter

Hopefully, this will help...

interface Param {
    title: string;
    callback: (error: Error, data: string) => void;
}

Or in a Function


let myfunction = (title: string, callback: (error: Error, data: string) => void): string => {

    callback(new Error(`Error Message Here.`), "This is callback data.");
    return title;

}

Is there a typical state machine implementation pattern?

In my experience using the 'switch' statement is the standard way to handle multiple possible states. Although I am surpirsed that you are passing in a transition value to the per-state processing. I thought the whole point of a state machine was that each state performed a single action. Then the next action/input determines which new state to transition into. So I would have expected each state processing function to immediately perform whatever is fixed for entering state and then afterwards decide if transition is needed to another state.

Where should I put <script> tags in HTML markup?

If you are using JQuery then put the javascript wherever you find it best and use $(document).ready() to ensure that things are loaded properly before executing any functions.

On a side note: I like all my script tags in the <head> section as that seems to be the cleanest place.

How to get file name from file path in android

Other Way is:

String[] parts = selectedFilePath.split("/");
    final String fileName = parts[parts.length-1];

Column order manipulation using col-lg-push and col-lg-pull in Twitter Bootstrap 3

I just felt like I'll add my $0.2 to those 2 good answers. I had a case when I had to move the last column all the way to the top in a 3-column situation.

[A][B][C]

[C]

[A]

[B]

Boostrap's class .col-xx-push-Xdoes nothing else but pushes a column to the right with left: XX%; so all you have to do to push a column right is to add the number of pseudo columns going left.

In this case:

two columns (col-md-5 and col-md-3) are going left, each with the value of the one that is going right;
one(col-md-4) is going right by the sum of the first two going left (5+3=8);

<div class="row">
    <div class="col-md-4 col-md-push-8 ">
        C
    </div>
    <div class="col-md-5 col-md-pull-4">
        A
    </div>
    <div class="col-md-3 col-md-pull-4">
        B
    </div>
</div>

enter image description here

Does VBA contain a comment block syntax?

Although there isn't a syntax, you can still get close by using the built-in block comment buttons:

If you're not viewing the Edit toolbar already, right-click on the toolbar and enable the Edit toolbar:

enter image description here

Then, select a block of code and hit the "Comment Block" button; or if it's already commented out, use the "Uncomment Block" button:

enter image description here

Fast and easy!

Multiple conditions in ngClass - Angular 4

<a [ngClass]="{'class1':array.status === 'active','class2':array.status === 'idle','class3':array.status === 'inactive',}">

Can I use multiple versions of jQuery on the same page?

Yes, it's doable due to jQuery's noconflict mode. http://blog.nemikor.com/2009/10/03/using-multiple-versions-of-jquery/

<!-- load jQuery 1.1.3 -->
<script type="text/javascript" src="http://example.com/jquery-1.1.3.js"></script>
<script type="text/javascript">
var jQuery_1_1_3 = $.noConflict(true);
</script>

<!-- load jQuery 1.3.2 -->
<script type="text/javascript" src="http://example.com/jquery-1.3.2.js"></script>
<script type="text/javascript">
var jQuery_1_3_2 = $.noConflict(true);
</script>

Then, instead of $('#selector').function();, you'd do jQuery_1_3_2('#selector').function(); or jQuery_1_1_3('#selector').function();.

How to install a private NPM module without my own registry?

In your private npm modules add

"private": true

to your package.json

Then to reference the private module in another module, use this in your package.json

{
    "name": "myapp",
    "dependencies": {
        "private-repo": "git+ssh://[email protected]:myaccount/myprivate.git#v1.0.0",
    }
}

ERROR: permission denied for sequence cities_id_seq using Postgres

What does .shape[] do in "for i in range(Y.shape[0])"?

The shape attribute for numpy arrays returns the dimensions of the array. If Y has n rows and m columns, then Y.shape is (n,m). So Y.shape[0] is n.

In [46]: Y = np.arange(12).reshape(3,4)

In [47]: Y
Out[47]: 
array([[ 0,  1,  2,  3],
       [ 4,  5,  6,  7],
       [ 8,  9, 10, 11]])

In [48]: Y.shape
Out[48]: (3, 4)

In [49]: Y.shape[0]
Out[49]: 3

Add disabled attribute to input element using Javascript

Just use jQuery's attr() method

$(this).closest("tr").next().show().find('.longboxsmall').attr('disabled', 'disabled');

WordPress asking for my FTP credentials to install plugins

If during installation of a plugin, Wordpress asks for your hostname or FTP details. Then follow these steps:

Login to your server and navigate to /var/www/html/wordpress/. Open wp-config.php and add this line after define(‘DB_COLLATE’)

define('FS_METHOD', 'direct');

If you get "Could not create directory" error. Give write permissions to your wordpress directory in recursive as

chmod -R go+w wordpress

NOTE. For security, revoke these permissions once you install a plugin as

chmod -R go-w wordpress

How to parse date string to Date?

I had this issue, and I set the Locale to US, then it work.

static DateFormat visitTimeFormat = new SimpleDateFormat("EEE MMM dd HH:mm:ss zzz yyyy",Locale.US);

for String "Sun Jul 08 00:06:30 UTC 2012"

How do I create a nice-looking DMG for Mac OS X using command-line tools?

Bringing this question up to date by providing this answer.

appdmg is a simple, easy-to-use, open-source command line program that creates dmg-files from a simple json specification. Take a look at the readme at the official website:

https://github.com/LinusU/node-appdmg

Quick example:

Install appdmg
```
npm install -g appdmg
```

Write a json file (spec.json)

{
  "title": "Test Title",
  "background": "background.png",
  "icon-size": 80,
  "contents": [
    { "x": 192, "y": 344, "type": "file", "path": "TestApp.app" },
    { "x": 448, "y": 344, "type": "link", "path": "/Applications" }
  ]
}

Run program
```
appdmg spec.json test.dmg
```

(disclaimer. I'm the creator of appdmg)

How to set level logging to DEBUG in Tomcat?

JULI logging levels for Tomcat

SEVERE - Serious failures

WARNING - Potential problems

INFO - Informational messages

CONFIG - Static configuration messages

FINE - Trace messages

FINER - Detailed trace messages

FINEST - Highly detailed trace messages

You can find here more https://documentation.progress.com/output/ua/OpenEdge_latest/index.html#page/pasoe-admin/tomcat-logging.html

Convert string to Time

string Time = "16:23:01";
DateTime date = DateTime.Parse(Time, System.Globalization.CultureInfo.CurrentCulture);

string t = date.ToString("HH:mm:ss tt");

Find the IP address of the client in an SSH session

Just type the following command on your Linux machine:

who

Dump a list in a pickle file and retrieve it back later

Pickling will serialize your list (convert it, and it's entries to a unique byte string), so you can save it to disk. You can also use pickle to retrieve your original list, loading from the saved file.

So, first build a list, then use pickle.dump to send it to a file...

Python 3.4.1 (default, May 21 2014, 12:39:51) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> mylist = ['I wish to complain about this parrot what I purchased not half an hour ago from this very boutique.', "Oh yes, the, uh, the Norwegian Blue...What's,uh...What's wrong with it?", "I'll tell you what's wrong with it, my lad. 'E's dead, that's what's wrong with it!", "No, no, 'e's uh,...he's resting."]
>>> 
>>> import pickle
>>> 
>>> with open('parrot.pkl', 'wb') as f:
...   pickle.dump(mylist, f)
... 
>>>

Then quit and come back later… and open with pickle.load...

Python 3.4.1 (default, May 21 2014, 12:39:51) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import pickle
>>> with open('parrot.pkl', 'rb') as f:
...   mynewlist = pickle.load(f)
... 
>>> mynewlist
['I wish to complain about this parrot what I purchased not half an hour ago from this very boutique.', "Oh yes, the, uh, the Norwegian Blue...What's,uh...What's wrong with it?", "I'll tell you what's wrong with it, my lad. 'E's dead, that's what's wrong with it!", "No, no, 'e's uh,...he's resting."]
>>>

Why do we use Base64?

It is more that the media validates the string encoding, so we want to ensure that the data is acceptable by a handling application (and doesn't contain a binary sequence representing EOL for example)

Imagine you want to send binary data in an email with encoding UTF-8 -- The email may not display correctly if the stream of ones and zeros creates a sequence which isn't valid Unicode in UTF-8 encoding.

The same type of thing happens in URLs when we want to encode characters not valid for a URL in the URL itself:

http://www.foo.com/hello my friend -> http://www.foo.com/hello%20my%20friend

This is because we want to send a space over a system that will think the space is smelly.

All we are doing is ensuring there is a 1-to-1 mapping between a known good, acceptable and non-detrimental sequence of bits to another literal sequence of bits, and that the handling application doesn't distinguish the encoding.

In your example, man may be valid ASCII in first form; but often you may want to transmit values that are random binary (ie sending an image in an email):

MIME-Version: 1.0
Content-Description: "Base64 encode of a.gif"
Content-Type: image/gif; name="a.gif"
Content-Transfer-Encoding: Base64
Content-Disposition: attachment; filename="a.gif"

Here we see that a GIF image is encoded in base64 as a chunk of an email. The email client reads the headers and decodes it. Because of the encoding, we can be sure the GIF doesn't contain anything that may be interpreted as protocol and we avoid inserting data that SMTP or POP may find significant.

intellij incorrectly saying no beans of type found for autowired repository

As long as your tests are passing you are good, hit alt + enter by taking the cursor over the error and inside the submenu of the first item you will find Disable Inspection select that

Can a constructor in Java be private?

Yes and it is used to prevent instantiation and subsequently overriding. This is most often used in singleton classes.

What does $(function() {} ); do?

This is a shortcut for $(document).ready(), which is executed when the browser has finished loading the page (meaning here, "when the DOM is available"). See http://www.learningjquery.com/2006/09/introducing-document-ready. If you are trying to call example() before the browser has finished loading the page, it may not work.

How to loop through a dataset in powershell?

The parser is having trouble concatenating your string. Try this:

write-host 'value is : '$i' '$($ds.Tables[1].Rows[$i][0])

Edit: Using double quotes might also be clearer since you can include the expressions within the quoted string:

write-host "value is : $i $($ds.Tables[1].Rows[$i][0])"

Input type DateTime - Value format?

This works for setting the value of the INPUT:

strftime('%Y-%m-%dT%H:%M:%S', time())

Programmatically center TextView text

try this method

  public void centerTextView(LinearLayout linearLayout) {
    TextView textView = new TextView(context);
    textView.setText(context.getString(R.string.no_records));
    textView.setTypeface(Typeface.DEFAULT_BOLD);
    textView.setGravity(Gravity.CENTER);
    textView.setTextSize(18.0f);
    textView.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT));
    linearLayout.addView(textView);
}

How do I use tools:overrideLibrary in a build.gradle file?

just changed only android:minSdkVersion="16" and it's work perfect C:\MyApp\platforms\android\CordovaLib\AndroidManifest.xml

Command not found after npm install in zsh

I think the problem is more about the ZSH completion.

You need to add this line in your .zshrc:

zstyle ':completion:*' rehash true

If you have Oh-my-zsh, a PR has been made, you can integrate it until it is pulled: https://github.com/robbyrussell/oh-my-zsh/issues/3440

Can HTTP POST be limitless?

POST allows for an arbitrary length of data to be sent to a server, but there are limitations based on timeouts/bandwidth etc.

I think basically, it's safer to assume that it's not okay to send lots of data.

Object does not support item assignment error

The error seems clear: model objects do not support item assignment. MyModel.objects.latest('id')['foo'] = 'bar' will throw this same error.

It's a little confusing that your model instance is called projectForm...

To reproduce your first block of code in a loop, you need to use setattr

for k,v in session_results.iteritems():
    setattr(projectForm, k, v)

Notepad++ add to every line

Please find the Screenshot below which Add a new word at the start and end of the line at a single shot

Very Simple, Very Smooth, JavaScript Marquee

I just created a simple jQuery plugin for that. Try it ;)

https://github.com/aamirafridi/jQuery.Marquee

"The import org.springframework cannot be resolved."

The only solution worked for me is add maven-compiler-plugin to the pom.xml

<project ...>
    ...
    <build>
        ...
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                    <fork>true</fork>
                    <executable>C:\Program Files\Java\jdk1.7.0_79\bin\javac</executable>
                </configuration>
            </plugin>
        </plugins>
    </build>
    ...
</project>

to_string not declared in scope

I fixed this problem by changing the first line in Application.mk from

APP_STL := gnustl_static

APP_STL := c++_static

How to create a QR code reader in a HTML5 website?

The algorithm that drives http://www.webqr.com is a JavaScript implementation of https://github.com/LazarSoft/jsqrcode. I haven't tried how reliable it is yet, but that's certainly the easier plug-and-play solution (client- or server-side) out of the two.

Adding attribute in jQuery

$('#someid').attr('disabled', 'true');

Using a different font with twitter bootstrap

The easiest way I've seen is to use Google Fonts.

Go to Google Fonts and choose a font, then Google will give you a link to put in your HTML.

Google's link to your font

Then add this to your custom.css:

h1, h2, h3, h4, h5, h6 {
    font-family: 'Your Font' !important;
}
p, div {
    font-family: 'Your Font' !important;
}

body {
   font-family: 'Your Font' !important;
}

Sql Server : How to use an aggregate function like MAX in a WHERE clause

But its still giving an error message in Query Builder. I am using SqlServerCe 2008.

SELECT         Products_Master.ProductName, Order_Products.Quantity, Order_Details.TotalTax, Order_Products.Cost, Order_Details.Discount, 
                     Order_Details.TotalPrice
FROM           Order_Products INNER JOIN
                     Order_Details ON Order_Details.OrderID = Order_Products.OrderID INNER JOIN
                     Products_Master ON Products_Master.ProductCode = Order_Products.ProductCode
HAVING        (Order_Details.OrderID = (SELECT MAX(OrderID) AS Expr1 FROM Order_Details AS mx1))

I replaced WHERE with HAVING as said by @powerlord. But still showing an error.

Error parsing the query. [Token line number = 1, Token line offset = 371, Token in error = SELECT]

Need to reset git branch to origin version

How to check if a file exists in Documents folder?

Swift 3:

let documentsURL = try! FileManager().url(for: .documentDirectory,
                                          in: .userDomainMask,
                                          appropriateFor: nil,
                                          create: true)

... gives you a file URL of the documents directory. The following checks if there's a file named foo.html:

let fooURL = documentsURL.appendingPathComponent("foo.html")
let fileExists = FileManager().fileExists(atPath: fooURL.path)

Objective-C:

NSString* documentsPath = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];

NSString* foofile = [documentsPath stringByAppendingPathComponent:@"foo.html"];
BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:foofile];

IE and Edge fix for object-fit: cover;

There is no rule to achieve that using CSS only, besides the object-fit (that you are currently using), which has partial support in EDGE¹ so if you want to use this in IE, you have to use a object-fit polyfill in case you want to use just the element img, otherwise you have to do some workarounds.

You can see the the object-fit support here

UPDATE(2019)

You can use a simple JS snippet to detect if the object-fit is supported and then replace the img for a svg

_x000D_

//ES6 version
if ('objectFit' in document.documentElement.style === false) {
    document.addEventListener('DOMContentLoaded', () => {
        document.querySelectorAll('img[data-object-fit]').forEach(image => {
            (image.runtimeStyle || image.style).background = `url("${image.src}") no-repeat 50%/${image.currentStyle ? image.currentStyle['object-fit'] : image.getAttribute('data-object-fit')}`
            image.src = `data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='${image.width}' height='${image.height}'%3E%3C/svg%3E`
        })
    })
}

//ES5 version transpiled from code above with BabelJS
if ('objectFit' in document.documentElement.style === false) {
    document.addEventListener('DOMContentLoaded', function() {
        document.querySelectorAll('img[data-object-fit]').forEach(function(image) {
            (image.runtimeStyle || image.style).background = "url(\"".concat(image.src, "\") no-repeat 50%/").concat(image.currentStyle ? image.currentStyle['object-fit'] : image.getAttribute('data-object-fit'));
            image.src = "data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='".concat(image.width, "' height='").concat(image.height, "'%3E%3C/svg%3E");
        });
    });
}

_x000D_

img {
  display: inline-flex;
  width: 175px;
  height: 175px;
  margin-right: 10px;
  border: 1px solid red
}

[data-object-fit='cover'] {
  object-fit: cover
}

[data-object-fit='contain'] {
  object-fit: contain
}

_x000D_

<img data-object-fit='cover' src='//picsum.photos/1200/600' />
<img data-object-fit='contain' src='//picsum.photos/1200/600' />
<img src='//picsum.photos/1200/600' />

_x000D_

UPDATE(2018)

1 - EDGE has now partial support for object-fit since version 16, and by partial, it means only works in img element (future version 18 still has only partial support)

How do I access call log for android?

This is method used to get the Call log. Just put this method in you class and get the List of the Call Log.

Check out this

private String getCallDetails() {

        StringBuffer sb = new StringBuffer();
        Cursor managedCursor = managedQuery(CallLog.Calls.CONTENT_URI, null,
                null, null, null);
        int number = managedCursor.getColumnIndex(CallLog.Calls.NUMBER);
        int type = managedCursor.getColumnIndex(CallLog.Calls.TYPE);
        int date = managedCursor.getColumnIndex(CallLog.Calls.DATE);
        int duration = managedCursor.getColumnIndex(CallLog.Calls.DURATION);
        sb.append("Call Details :");
        while (managedCursor.moveToNext()) {
            String phNumber = managedCursor.getString(number);
            String callType = managedCursor.getString(type);
            String callDate = managedCursor.getString(date);
            Date callDayTime = new Date(Long.valueOf(callDate));
            String callDuration = managedCursor.getString(duration);
            String dir = null;
            int dircode = Integer.parseInt(callType);
            switch (dircode) {
            case CallLog.Calls.OUTGOING_TYPE:
                dir = "OUTGOING";
                break;

            case CallLog.Calls.INCOMING_TYPE:
                dir = "INCOMING";
                break;

            case CallLog.Calls.MISSED_TYPE:
                dir = "MISSED";
                break;
            }
            sb.append("\nPhone Number:--- " + phNumber + " \nCall Type:--- "
                    + dir + " \nCall Date:--- " + callDayTime
                    + " \nCall duration in sec :--- " + callDuration);
            sb.append("\n----------------------------------");
        }
        managedCursor.close();
        return sb.toString();

    }

the output looks

enter image description here

Difference between Visibility.Collapsed and Visibility.Hidden

Even though a bit old thread, for those who still looking for the differences:

Aside from layout (space) taken in Hidden and not taken in Collapsed, there is another difference.

If we have custom controls inside this 'Collapsed' main control, the next time we set it to Visible, it will "load" all custom controls. It will not pre-load when window is started.

As for 'Hidden', it will load all custom controls + main control which we set as hidden when the "window" is started.

What does void mean in C, C++, and C#?

If you're explaining the concept to a beginner, it might be helpful to use an analogy. The use of void in all these cases is analogous in meaning to a page in a book which has the following words, "This page left intentionally blank." It is to differentiate to the compiler between something which should be flagged as an error, versus a type which is intentionally to be left blank because that is the behavior you want.

It always appears in code where normally you would expect to see a type appear, such as a return type or a pointer type. This is why in C#, void maps to an actual CLR type, System.Void because it is a type in itself.

Some programming languages never developed the concept of void, just like some human cultures never invented the concept of the number zero. Void represents the same advancement in a programming language as the concept of zero represents to human language.

How to call a vue.js function on page load

If you get data in array you can do like below. It's worked for me

    <template>
    {{ id }}
    </template>
    <script>

    import axios from "axios";

        export default {
            name: 'HelloWorld',
            data () {
                return {
                    id: "",

                }
            },
    mounted() {
                axios({ method: "GET", "url": "https://localhost:42/api/getdata" }).then(result => {
                    console.log(result.data[0].LoginId);
                    this.id = result.data[0].LoginId;
                }, error => {
                    console.error(error);
                });
            },
</script>

500 internal server error at GetResponse()

In my case my request object inherited from base object. Without knowingly I added a property with int? in my request object and my base object also has same property ( same name ) with int datatype. I noticed this and deleted the property which I added in request object and after that it worked fine.

Concatenating null strings in Java

This is behavior specified in the Java API's String.valueOf(Object) method. When you do concatenation, valueOf is used to get the String representation. There is a special case if the Object is null, in which case the string "null" is used.

public static String valueOf(Object obj)

Returns the string representation of the Object argument.

Parameters: obj - an Object.

Returns:

if the argument is null, then a string equal to "null"; otherwise, the value of obj.toString() is returned.

Python re.sub replace with matched content

Simply use \1 instead of $1:

In [1]: import re

In [2]: method = 'images/:id/huge'

In [3]: re.sub(r'(:[a-z]+)', r'<span>\1</span>', method)
Out[3]: 'images/<span>:id</span>/huge'

Also note the use of raw strings (r'...') for regular expressions. It is not mandatory but removes the need to escape backslashes, arguably making the code slightly more readable.

Content Security Policy "data" not working for base64 Images in Chrome 28

Try this

data to load:

<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 4 5'><path fill='#343a40' d='M2 0L0 2h4zm0 5L0 3h4z'/></svg>

get a utf8 to base64 convertor and convert the "svg" string to:

PHN2ZyB4bWxucz0naHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmcnIHZpZXdCb3g9JzAgMCA0IDUn
PjxwYXRoIGZpbGw9JyMzNDNhNDAnIGQ9J00yIDBMMCAyaDR6bTAgNUwwIDNoNHonLz48L3N2Zz4=

and the CSP is

img-src data: image/svg+xml;base64,PHN2ZyB4bWxucz0naHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmcnIHZpZXdCb3g9JzAgMCA0IDUn
PjxwYXRoIGZpbGw9JyMzNDNhNDAnIGQ9J00yIDBMMCAyaDR6bTAgNUwwIDNoNHonLz48L3N2Zz4=

Given a view, how do I get its viewController?

To get reference to UIViewController having UIView, you could make extension of UIResponder (which is super class for UIView and UIViewController), which allows to go up through the responder chain and thus reaching UIViewController (otherwise returning nil).

extension UIResponder {
    func getParentViewController() -> UIViewController? {
        if self.nextResponder() is UIViewController {
            return self.nextResponder() as? UIViewController
        } else {
            if self.nextResponder() != nil {
                return (self.nextResponder()!).getParentViewController()
            }
            else {return nil}
        }
    }
}

//Swift 3
extension UIResponder {
    func getParentViewController() -> UIViewController? {
        if self.next is UIViewController {
            return self.next as? UIViewController
        } else {
            if self.next != nil {
                return (self.next!).getParentViewController()
            }
            else {return nil}
        }
    }
}

let vc = UIViewController()
let view = UIView()
vc.view.addSubview(view)
view.getParentViewController() //provide reference to vc

When to use std::size_t?

A good rule of thumb is for anything that you need to compare in the loop condition against something that is naturally a std::size_t itself.

std::size_t is the type of any sizeof expression and as is guaranteed to be able to express the maximum size of any object (including any array) in C++. By extension it is also guaranteed to be big enough for any array index so it is a natural type for a loop by index over an array.

If you are just counting up to a number then it may be more natural to use either the type of the variable that holds that number or an int or unsigned int (if large enough) as these should be a natural size for the machine.

Git error: src refspec master does not match any error: failed to push some refs

It doesn't recognize that you have a master branch, but I found a way to get around it. I found out that there's nothing special about a master branch, you can just create another branch and call it master branch and that's what I did.

To create a master branch:

git checkout -b master

And you can work off of that.

Convert LocalDate to LocalDateTime or java.sql.Timestamp

function call asStartOfDay() on java.time.LocalDate object returns a java.time.LocalDateTime object

How to add an existing folder with files to SVN?

If I correctly understood your use case, I suggest to try using svn add to put the new folder under version, see here. The following will add the new folder with files recursively under version control (if you are inside valid working copy):

svn add new_folder
svn commit -m "Add New folder to the project"

If you are not in a working copy, create it with svn checkout, copy new_folder there and do the above steps.

Try svn import, see here; the following will create a new folder and upload files to the repository:

svn import -m "Import new folder to the project" new_folder \
        http://SVN_REPO/repos/trunk/new_folder

Also note that:

After importing data, note that the original tree is not under version control. To start working, you still need to svn checkout a fresh working copy of the tree

How to get the first column of a pandas DataFrame as a Series?

Isn't this the simplest way?

By column name:

In [20]: df = pd.DataFrame({'x' : [1, 2, 3, 4], 'y' : [4, 5, 6, 7]})
In [21]: df
Out[21]:
    x   y
0   1   4
1   2   5
2   3   6
3   4   7

In [23]: df.x
Out[23]:
0    1
1    2
2    3
3    4
Name: x, dtype: int64

In [24]: type(df.x)
Out[24]:
pandas.core.series.Series

Start/Stop and Restart Jenkins service on Windows

Open Console/Command line --> Go to your Jenkins installation directory. Execute the following commands respectively:

to stop:
jenkins.exe stop

to start:
jenkins.exe start

to restart:
jenkins.exe restart

How do I read the first line of a file using cat?

You dont need any external command if you have bash v4+

< file.txt mapfile -n1 && echo ${MAPFILE[0]}

or if you really want cat

cat file.txt | mapfile -n1 && echo ${MAPFILE[0]}

mysql update column with value from another table

Store your data in temp table

Select * into tempTable from table1

Now update the column

 UPDATE table1
    SET table1.FileName = (select FileName from tempTable where tempTable.id = table1.ID);

converting multiple columns from character to numeric format in r

I used this code to convert all columns to numeric except the first one:

    library(dplyr)
    # check structure, row and column number with: glimpse(df)
    # convert to numeric e.g. from 2nd column to 10th column
    df <- df %>% 
     mutate_at(c(2:10), as.numeric)

Read text file into string. C++ ifstream

To read a whole line from a file into a string, use std::getline like so:

 std::ifstream file("my_file");
 std::string temp;
 std::getline(file, temp);

You can do this in a loop to until the end of the file like so:

 std::ifstream file("my_file");
 std::string temp;
 while(std::getline(file, temp)) {
      //Do with temp
 }

References

http://en.cppreference.com/w/cpp/string/basic_string/getline

http://en.cppreference.com/w/cpp/string/basic_string

$(this).val() not working to get text from span using jquery

-None of the above consistently worked for me. So here is the solution i worked out that works consistently across all browsers as it uses basic functionality. Hope this may help others. Using jQuery 8.2

1) Get the jquery object for "span". 2) Get the DOM object from above. Using jquery .get(0) 3) Using DOM's object's innerText get the text.

Here is a simple example

var curSpan = $(this).parent().children(' span').get(0);
var spansText = curSpan.innerText;

HTML

<div >
<input type='checkbox' /><span >testinput</span> 
</div>

Resetting Select2 value in dropdown with reset button

To achieve a generic solution, why not do this:

$(':reset').live('click', function(){
    var $r = $(this);
    setTimeout(function(){ 
        $r.closest('form').find('.select2-offscreen').trigger('change'); 
    }, 10);
});

This way: You'll not have to make a new logic for each select2 on your application.

And, you don't have to know the default value (which, by the way, does not have to be "" or even the first option)

Finally, setting the value to :selected would not always achieve a true reset, since the current selected might well have been set programmatically on the client, whereas the default action of the form select is to return input element values to the server-sent ones.

EDIT: Alternatively, considering the deprecated status of live, we could replace the first line with this:

$('form:has(:reset)').on('click', ':reset', function(){

or better still:

$('form:has(:reset)').on('reset', function(){

PS: I personally feel that resetting on reset, as well as triggering blur and focus events attached to the original select, are some of the most conspicuous "missing" features in select2!

Is there a PowerShell "string does not contain" cmdlet or syntax?

You can use the -notmatch operator to get the lines that don't have the characters you are interested in.

     Get-Content $FileName | foreach-object { 
     if ($_ -notmatch $arrayofStringsNotInterestedIn) { $) }

Origin <origin> is not allowed by Access-Control-Allow-Origin

In case anyone searching for the solution , if you are using express here is the quick solution .

const express = require('express')
const cors = require('cors')
const app = express()

1) install cors using npm npm install cors --save

2) import it [require ] const cors = require('cors')

3) use it as middleware app.use(cors())

for details insatll and usage of cors . That is it, hopefully it works.

Android MediaPlayer Stop and Play

To stop the Media Player without the risk of an Illegal State Exception, you must do

  try {
        mp.reset();
        mp.prepare();
        mp.stop();
        mp.release();
        mp=null;
       }
  catch (Exception e)
         {
           e.printStackTrace();
         }

rather than just

try {
       mp.stop();
       mp.release();
       mp=null;
    } 
catch (Exception e) 
    {
      e.printStackTrace();
    }

How do I update Ruby Gems from behind a Proxy (ISA-NTLM)

I've been using cntlm (http://cntlm.sourceforge.net/) at work. Configuration is very similar to ntlmaps.

gem install --http-proxy http://localhost:3128 _name_of_gem_

Works great, and also allows me to connect my Ubuntu box to the ISA proxy.

Check out http://cntlm.wiki.sourceforge.net/ for more information

Polymorphism vs Overriding vs Overloading

Polymorphism is more likely as far as it's meaning is concerned ... to OVERRIDING in java

It's all about different behavior of the SAME object in different situations(In programming way ... you can call different ARGUMENTS)

I think the example below will help you to understand ... Though it's not PURE java code ...

     public void See(Friend)
     {
        System.out.println("Talk");
     }

But if we change the ARGUMENT ... the BEHAVIOR will be changed ...

     public void See(Enemy)
     {
        System.out.println("Run");
     }

The Person(here the "Object") is same ...

Android: ProgressDialog.show() crashes with getApplicationContext

Which API version are you using? If I'm right about what the problem is then this was fixed in Android 1.6 (API version 4).

It looks like the object reference that getApplicationContext() is returning just points to null. I think you're having a problem similar to one I had in that some of the code in the onCreate() is being run before the window is actually done being built. This is going to be a hack, but try launching a new Thread in a few hundred milliseconds (IIRC: 300-400 seemed to work for me, but you'll need to tinker) that opens your ProgressDialog and starts anything else you needed (eg. network IO). Something like this:

@Override
public void onCreate(Bundle savedInstanceState) {
    // do all your other stuff here

    new Handler().postDelayed(new Runnable() {
        @Override
        public void run() {
            mProgressDialog = ProgressDialog.show(
               YouTube.this.getApplicationContext(), "",
               YouTube.this.getString(R.string.loading), true);

            // start time consuming background process here
        }
    }, 1000); // starting it in 1 second
}

How to compile makefile using MinGW?

First check if mingw32-make is installed on your system. Use mingw32-make.exe command in windows terminal or cmd to check, else install the package mingw32-make-bin.

then go to bin directory default ( C:\MinGW\bin) create new file make.bat

@echo off
"%~dp0mingw32-make.exe" %*

add the above content and save it

set the env variable in powershell

$Env:CC="gcc"

then compile the file

make hello

where hello.c is the name of source code

Iterating over dictionaries using 'for' loops

You can check the implementation of CPython's dicttype on GitHub. This is the signature of method that implements the dict iterator:

_PyDict_Next(PyObject *op, Py_ssize_t *ppos, PyObject **pkey,
             PyObject **pvalue, Py_hash_t *phash)

CPython dictobject.c

Passing arguments forward to another javascript function

Spread operator

The spread operator allows an expression to be expanded in places where multiple arguments (for function calls) or multiple elements (for array literals) are expected.

ECMAScript ES6 added a new operator that lets you do this in a more practical way: ...Spread Operator.

Example without using the apply method:

_x000D_

function a(...args){_x000D_
  b(...args);_x000D_
  b(6, ...args, 8) // You can even add more elements_x000D_
}_x000D_
function b(){_x000D_
  console.log(arguments)_x000D_
}_x000D_
_x000D_
a(1, 2, 3)

_x000D_

Note This snippet returns a syntax error if your browser still uses ES5.

^{Editor's note: Since the snippet uses console.log(), you must open your browser's JS console to see the result - there will be no in-page result.}

It will display this result:

In short, the spread operator can be used for different purposes if you're using arrays, so it can also be used for function arguments, you can see a similar example explained in the official docs: Rest parameters

Parsing Json rest api response in C#

Create classes that match your data,
then use JSON.NET to convert the JSON data to regular C# objects.

Step 1: a great tool - http://json2csharp.com/ - the results generated by it are below

Step 2: JToken.Parse(...).ToObject<RootObject>().

public class Meta
{
    public int code { get; set; }
    public string status { get; set; }
    public string method_name { get; set; }
}

public class Photos
{
    public int total_count { get; set; }
}

public class Storage
{
    public int used { get; set; }
}

public class Stats
{
    public Photos photos { get; set; }
    public Storage storage { get; set; }
}

public class From
{
    public string id { get; set; }
    public string first_name { get; set; }
    public string created_at { get; set; }
    public string updated_at { get; set; }
    public List<object> external_accounts { get; set; }
    public string email { get; set; }
    public string confirmed_at { get; set; }
    public string username { get; set; }
    public string admin { get; set; }
    public Stats stats { get; set; }
}

public class ParticipateUser
{
    public string id { get; set; }
    public string first_name { get; set; }
    public string created_at { get; set; }
    public string updated_at { get; set; }
    public List<object> external_accounts { get; set; }
    public string email { get; set; }
    public string confirmed_at { get; set; }
    public string username { get; set; }
    public string admin { get; set; }
    public Stats stats { get; set; }
}

public class ChatGroup
{
    public string id { get; set; }
    public string created_at { get; set; }
    public string updated_at { get; set; }
    public string message { get; set; }
    public List<ParticipateUser> participate_users { get; set; }
}

public class Chat
{
    public string id { get; set; }
    public string created_at { get; set; }
    public string updated_at { get; set; }
    public string message { get; set; }
    public From from { get; set; }
    public ChatGroup chat_group { get; set; }
}

public class Response
{
    public List<Chat> chats { get; set; }
}

public class RootObject
{
    public Meta meta { get; set; }
    public Response response { get; set; }
}

How to POST URL in data of a curl request

Perhaps you don't have to include the single quotes:

curl --request POST 'http://localhost/Service' --data "path=/xyz/pqr/test/&fileName=1.doc"

Update: Reading curl's manual, you could actually separate both fields with two --data:

curl --request POST 'http://localhost/Service' --data "path=/xyz/pqr/test/" --data "fileName=1.doc"

You could also try --data-binary:

curl --request POST 'http://localhost/Service' --data-binary "path=/xyz/pqr/test/" --data-binary "fileName=1.doc"

And --data-urlencode:

curl --request POST 'http://localhost/Service' --data-urlencode "path=/xyz/pqr/test/" --data-urlencode "fileName=1.doc"

batch file - counting number of files in folder and storing in a variable

The fastest code for counting files with ANY attributes in folder %FOLDER% and its subfolders is the following. The code is for script in a command script (batch) file.

@for /f %%a in ('2^>nul dir "%FOLDER%" /a-d/b/-o/-p/s^|find /v /c ""') do set n=%%a
@echo Total files: %n%.

How to change colors of a Drawable in Android?

Int color = Color.GRAY; 
// or int color = Color.argb(123,255,0,5);
// or int color = 0xaaff000;

in XML /res/values/color.xml

<?xml version="1.0" encoding="utf-8">
<resources>
    <color name="colorRed">#ff0000</color>
</resoures>

Java Code

int color = ContextCompat.getColor(context, R.color.colorRed);

GradientDrawable drawableBg = yourView.getBackground().mutate();
drawableBg.setColor(color);

Difference between Width:100% and width:100vw?

vw and vh stand for viewport width and viewport height respectively.

The difference between using width: 100vw instead of width: 100% is that while 100% will make the element fit all the space available, the viewport width has a specific measure, in this case the width of the available screen, including the document margin.

If you set the style body { margin: 0 }, 100vw should behave the same as 100%.

Additional notes

Using vw as unit for everything in your website, including font sizes and heights, will make it so that the site is always displayed proportionally to the device's screen width regardless of it's resolution. This makes it super easy to ensure your website is displayed properly in both workstation and mobile.

You can set font-size: 1vw (or whatever size suits your project) in your body CSS and everything specified in rem units will automatically scale according to the device screen, so it's easy to port existing projects and even frameworks (such as Bootstrap) to this concept.

Is it possible to CONTINUE a loop from an exception?

For this example you really should just use an outer join.

declare
begin
  FOR attr_rec IN ( 
    select attr 
    from USER_TABLE u 
    left outer join attribute_table a 
    on ( u.USERTYPE = 'X' and a.user_id = u.id ) 
  ) LOOP
    <process records> 
    <if primary key of attribute_table is null 
     then the attribute does not exist for this user.>
  END LOOP;
END;

How do you add an SDK to Android Studio?

I had opened a ticket also with Google's support, and received the solution. Instead of choosing the sdk/platform/android-16 folder, if you select the top-level "sdk" folder instead, you'll then be asked to choose which SDK you want to add. This worked!

enter image description here

Validate SSL certificates with Python

The following code allows you to benefit from all SSL validation checks (e.g. date validity, CA certificate chain ...) EXCEPT a pluggable verification step e.g. to verify the hostname or do other additional certificate verification steps.

from httplib import HTTPSConnection
import ssl


def create_custom_HTTPSConnection(host):

    def verify_cert(cert, host):
        # Write your code here
        # You can certainly base yourself on ssl.match_hostname
        # Raise ssl.CertificateError if verification fails
        print 'Host:', host
        print 'Peer cert:', cert

    class CustomHTTPSConnection(HTTPSConnection, object):
        def connect(self):
            super(CustomHTTPSConnection, self).connect()
            cert = self.sock.getpeercert()
            verify_cert(cert, host)

    context = ssl.create_default_context()
    context.check_hostname = False
    return CustomHTTPSConnection(host=host, context=context)


if __name__ == '__main__':
    # try expired.badssl.com or self-signed.badssl.com !
    conn = create_custom_HTTPSConnection('badssl.com')
    conn.request('GET', '/')
    conn.getresponse().read()

Accept server's self-signed ssl certificate in Java client

Rather than setting the default socket factory (which IMO is a bad thing) - yhis will just affect the current connection rather than every SSL connection you try to open:

URLConnection connection = url.openConnection();
    // JMD - this is a better way to do it that doesn't override the default SSL factory.
    if (connection instanceof HttpsURLConnection)
    {
        HttpsURLConnection conHttps = (HttpsURLConnection) connection;
        // Set up a Trust all manager
        TrustManager[] trustAllCerts = new TrustManager[] { new X509TrustManager()
        {

            public java.security.cert.X509Certificate[] getAcceptedIssuers()
            {
                return null;
            }

            public void checkClientTrusted(
                java.security.cert.X509Certificate[] certs, String authType)
            {
            }

            public void checkServerTrusted(
                java.security.cert.X509Certificate[] certs, String authType)
            {
            }
        } };

        // Get a new SSL context
        SSLContext sc = SSLContext.getInstance("TLSv1.2");
        sc.init(null, trustAllCerts, new java.security.SecureRandom());
        // Set our connection to use this SSL context, with the "Trust all" manager in place.
        conHttps.setSSLSocketFactory(sc.getSocketFactory());
        // Also force it to trust all hosts
        HostnameVerifier allHostsValid = new HostnameVerifier() {
            public boolean verify(String hostname, SSLSession session) {
                return true;
            }
        };
        // and set the hostname verifier.
        conHttps.setHostnameVerifier(allHostsValid);
    }
InputStream stream = connection.getInputStream();

Programs & Examples On #Jsonreader

Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 1 path $

Error reading JObject from JsonReader. Current JsonReader item is not an object: StartArray. Path

how to parse JSON file with GSON

NewtonSoft.Json Serialize and Deserialize class with property of type IEnumerable<ISomeInterface>

What is an example of the simplest possible Socket.io example?

index.html

app.js

Lock, mutex, semaphore... what's the difference?

Line Break in XML?

How to set 00:00:00 using moment.js

How to read/write files in .Net Core?

Select all columns except one in MySQL?

Using Camera in the Android emulator

How to resolve 'npm should be run outside of the node repl, in your normal shell'

How to create a laravel hashed password

Position of a string within a string using Linux shell script?

"X does not name a type" error in C++

Javascript Append Child AFTER Element

How can I pass a Bitmap object from one activity to another

What is the difference between a .cpp file and a .h file?

Replacing H1 text with a logo image: best method for SEO and accessibility?

How to view user privileges using windows cmd?

Remove xticks in a matplotlib plot?

Fast and simple String encrypt/decrypt in JAVA

How can I parse a CSV string with JavaScript, which contains comma in data?

Errors in SQL Server while importing CSV file despite varchar(MAX) being used for each column

Decimal or numeric values in regular expression validation

Getting title and meta tags from external website

Add a new item to a dictionary in Python

Auto margins don't center image in page

Password encryption at client side

How to call a method after a delay in Android

Target WSGI script cannot be loaded as Python module

Can you have a <span> within a <span>?

Checking if a list is empty with LINQ

Ubuntu - Run command on start-up with "sudo"

resize2fs: Bad magic number in super-block while trying to open

How to convert Moment.js date to users local timezone?

Static methods in Python?

Test credit card numbers for use with PayPal sandbox

Why does git status show branch is up-to-date when changes exist upstream?

Match exact string

Remove multiple whitespaces

How to make an AJAX call without jQuery?

How to check type of object in Python?

What type() means:

For comparisons:

best way to get the key of a key/value javascript object

How to deserialize xml to object

Having trouble setting working directory

What does the Java assert keyword do, and when should it be used?

How to get coordinates of an svg element?

Can we instantiate an abstract class?

How can I view an object with an alert()

fork: retry: Resource temporarily unavailable

MySQL ERROR 1045 (28000): Access denied for user 'bill'@'localhost' (using password: YES)

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

Output grep results to text file, need cleaner output

Bootstrap: align input with button

Jenkins: Cannot define variable in pipeline stage

How to embed a YouTube channel into a webpage

Convert JSON to Map

random.seed(): What does it do?

How can I pad a value with leading zeros?

regex to remove all text before a character

How to add default value for html <textarea>?

Make button width fit to the text

Insert image after each list item

Rounding a double to turn it into an int (java)

Checking for directory and file write permissions in .NET

What is the PostgreSQL equivalent for ISNULL()

How can I install a local gem?

Round a divided number in Bash

One-liner if statements, how to convert this if-else-statement

How to convert number to words in java

How do I use method overloading in Python?

How to solve SyntaxError on autogenerated manage.py?

Java ArrayList - how can I tell if two lists are equal, order not mattering?

Why am I getting "Thread was being aborted" in ASP.NET?