Programs & Examples On #Activeperl

ActivePerl is a distribution of Perl from ActiveState (formerly part of Sophos) for Windows, Mac OS X, Linux, Solaris, AIX and HP-UX.

How to properly express JPQL "join fetch" with "where" clause as JPA 2 CriteriaQuery?

I will show visually the problem, using the great example from James answer and adding the alternative solution.

When you do the follow query, without the FETCH:

Select e from Employee e 
join e.phones p 
where p.areaCode = '613'

You will have the follow results from Employee as you expected:

EmployeeId EmployeeName PhoneId PhoneAreaCode
1 James 5 613
1 James 6 416

But when you add the FETCH word on JOIN, this is what happens:

EmployeeId EmployeeName PhoneId PhoneAreaCode
1 James 5 613

The generated SQL is the same for the two queries, but the Hibernate removes on memory the 416 register when you use WHERE on the FETCH join.

So, to bring all phones and apply the WHERE correctly, you need to have two JOINs: one for the WHERE and another for the FETCH. Like:

Select e from Employee e 
join e.phones p 
join fetch e.phones      //no alias, to not commit the mistake
where p.areaCode = '613'

Java default constructor

Neither of them. If you define it, it's not the default.

The default constructor is the no-argument constructor automatically generated unless you define another constructor. Any uninitialised fields will be set to their default values. For your example, it would look like this assuming that the types are String, int and int, and that the class itself is public:

public Module()
{
  super();
  this.name = null;
  this.credits = 0;
  this.hours = 0;
}

This is exactly the same as

public Module()
{}

And exactly the same as having no constructors at all. However, if you define at least one constructor, the default constructor is not generated.

Reference: Java Language Specification

If a class contains no constructor declarations, then a default constructor with no formal parameters and no throws clause is implicitly declared.

Clarification

Technically it is not the constructor (default or otherwise) that default-initialises the fields. However, I am leaving it the answer because

  • the question got the defaults wrong, and
  • the constructor has exactly the same effect whether they are included or not.

exception.getMessage() output with class name

My guess is that you've got something in method1 which wraps one exception in another, and uses the toString() of the nested exception as the message of the wrapper. I suggest you take a copy of your project, and remove as much as you can while keeping the problem, until you've got a short but complete program which demonstrates it - at which point either it'll be clear what's going on, or we'll be in a better position to help fix it.

Here's a short but complete program which demonstrates RuntimeException.getMessage() behaving correctly:

public class Test {
    public static void main(String[] args) {
        try {
            failingMethod();
        } catch (Exception e) {
            System.out.println("Error: " + e.getMessage());
        }
    }       

    private static void failingMethod() {
        throw new RuntimeException("Just the message");
    }
}

Output:

Error: Just the message

Use of Finalize/Dispose method in C#

Pattern from msdn

public class BaseResource: IDisposable
{
   private IntPtr handle;
   private Component Components;
   private bool disposed = false;
   public BaseResource()
   {
   }
   public void Dispose()
   {
      Dispose(true);      
      GC.SuppressFinalize(this);
   }
   protected virtual void Dispose(bool disposing)
   {
      if(!this.disposed)
      {        
         if(disposing)
         {
            Components.Dispose();
         }         
         CloseHandle(handle);
         handle = IntPtr.Zero;
       }
      disposed = true;         
   }
   ~BaseResource()      
   {      Dispose(false);
   }
   public void DoSomething()
   {
      if(this.disposed)
      {
         throw new ObjectDisposedException();
      }
   }
}
public class MyResourceWrapper: BaseResource
{
   private ManagedResource addedManaged;
   private NativeResource addedNative;
   private bool disposed = false;
   public MyResourceWrapper()
   {
   }
   protected override void Dispose(bool disposing)
   {
      if(!this.disposed)
      {
         try
         {
            if(disposing)
            {             
               addedManaged.Dispose();         
            }
            CloseHandle(addedNative);
            this.disposed = true;
         }
         finally
         {
            base.Dispose(disposing);
         }
      }
   }
}

How to change the date format from MM/DD/YYYY to YYYY-MM-DD in PL/SQL?

if you need to change your column output date format just use to_char this well get you a string, not a date.

My Routes are Returning a 404, How can I Fix Them?

If you're using Vagrant though Homestead, it's possible there was an error mounting the shared folder. It looks like Vagrant takes your files from that folder and swaps out the files that are actually on the host machine on boot, so if there was an error, you're essentially trying to access your Laravel installation from when you first made it (which is why you're only getting "home"- that was generated during installation).

You can easily check this by sshing into your vm and checking the routes/web.php file to see if it's actually your file. If it isn't, exit out and vagrant halt, vagrant up, and look for errors on boot.

libxml install error using pip

No you are missing the Python header files. This mostly happens on Linux when you are using the system Python (there are reasons not to do that, but that's a different question).

You probably need to install some package, and it's probably called python-dev or python-devel.

 sudo yum install python-devel

or

 sudo aptitude install python-dev

Or somesuch.

How does one add keyboard languages and switch between them in Linux Mint 16?

For Linux (I am using Fedora 30) the Shortcut is (Window/Start + Space) Try that and tell me. That works for me

File loading by getClass().getResource()

The best way to access files from resource folder inside a jar is it to use the InputStream via getResourceAsStream. If you still need a the resource as a file instance you can copy the resource as a stream into a temporary file (the temp file will be deleted when the JVM exits):

public static File getResourceAsFile(String resourcePath) {
    try {
        InputStream in = ClassLoader.getSystemClassLoader().getResourceAsStream(resourcePath);
        if (in == null) {
            return null;
        }

        File tempFile = File.createTempFile(String.valueOf(in.hashCode()), ".tmp");
        tempFile.deleteOnExit();

        try (FileOutputStream out = new FileOutputStream(tempFile)) {
            //copy stream
            byte[] buffer = new byte[1024];
            int bytesRead;
            while ((bytesRead = in.read(buffer)) != -1) {
                out.write(buffer, 0, bytesRead);
            }
        }
        return tempFile;
    } catch (IOException e) {
        e.printStackTrace();
        return null;
    }
}

How do I create/edit a Manifest file?

As ibram stated, add the manifest thru solution explorer:

enter image description here

This creates a default manifest. Now, edit the manifest.

  • Update the assemblyIdentity name as your application.
  • Ask users to trust your application

enter image description here

  • Add supported OS

enter image description here

Filename too long in Git for Windows

TortoiseGit (Windows)

For anyone using TortoiseGit for Windows, I did this:

(1) Right-click on the folder containing your project. Select TortoiseGit -> Settings.

(2) On the "Git" tab, click the button to "Edit local .git/config".

(3) In the text file that pops up, under the [core] section, add: longpaths = true

Save and close everything, then re-try your commit. For me, this worked.enter image description here

I hope this minimizes any possible system-wide issues, since we are not editing the global .gitconfig file, but rather just the one for this particular repository.

Can angularjs routes have optional parameter values?

It looks like Angular has support for this now.

From the latest (v1.2.0) docs for $routeProvider.when(path, route):

path can contain optional named groups with a question mark (:name?)

With Twitter Bootstrap, how can I customize the h1 text color of one page and leave the other pages to be default?

The best way to solve this problem would be by starting with customizing Bootstrap using their customization tools.

http://getbootstrap.com/customize/

Go down to @headings-color and change it from "inherit" to something that you would like your headers to be across the site (if you like the default just change it to #333).

Note that this will keep all your headings the same color, as you requested.

Now in order to accomplish what you want that after you make this change you can now overwrite them specifically in your own CSS to apply your own color to them. The "inherit" keyword I always have found to be a pain in frameworks.

How to overwrite styling in Twitter Bootstrap

Add your own class, ex: <div class="sidebar right"></div>, with the CSS as

.sidebar.right { 
    float:right
} 

C Programming: How to read the whole file contents into a buffer

A portable solution could use getc.

#include <stdio.h>

char buffer[MAX_FILE_SIZE];
size_t i;

for (i = 0; i < MAX_FILE_SIZE; ++i)
{
    int c = getc(fp);

    if (c == EOF)
    {
        buffer[i] = 0x00;
        break;
    }

    buffer[i] = c;
}

If you don't want to have a MAX_FILE_SIZE macro or if it is a big number (such that buffer would be to big to fit on the stack), use dynamic allocation.

Recreate the default website in IIS

Check out this answer on SuperUser:

In short: Reinstall both IIS and WAS.

In details -

Step 1

Go to "Add remove programs" "Turn windows features on or off" Remove both IIS and WAS (Windows Process Activation Service) Restart the PC Step 2

Go to "Add remove programs" "Turn windows features on or off" Turn on both IIS and WAS (Windows Process Activation Service) Note: Reinstalling IIS alone won't help. You have to reinstall both IIS and WAS

This approach fixed the problem for me.

WAMP/XAMPP is responding very slow over localhost

In my case, load time is 5 times faster when this is disabled in php.ini :

;zend_extension = "\xampp\php\ext\php_xdebug-2.1.0-5.3-vc6.dll"

Add Keypair to existing EC2 instance

Though you can't add a key pair to a running EC2 instance directly, you can create a linux user and create a new key pair for him, then use it like you would with the original user's key pair.

In your case, you can ask the instance owner (who created it) to do the following. Thus, the instance owner doesn't have to share his own keys with you, but you would still be able to ssh into these instances. These steps were originally posted by Utkarsh Sengar (aka. @zengr) at http://utkarshsengar.com/2011/01/manage-multiple-accounts-on-1-amazon-ec2-instance/. I've made only a few small changes.

  1. Step 1: login by default “ubuntu” user:

    $ ssh -i my_orig_key.pem [email protected]
    
  2. Step 2: create a new user, we will call our new user “john”:

    [ubuntu@ip-11-111-111-111 ~]$ sudo adduser john
    

    Set password for “john” by:

    [ubuntu@ip-11-111-111-111 ~]$ sudo su -
    [root@ip-11-111-111-111 ubuntu]# passwd john
    

    Add “john” to sudoer’s list by:

    [root@ip-11-111-111-111 ubuntu]# visudo
    

    .. and add the following to the end of the file:

    john   ALL = (ALL)    ALL
    

    Alright! We have our new user created, now you need to generate the key file which will be needed to login, like we have my_orin_key.pem in Step 1.

    Now, exit and go back to ubuntu, out of root.

    [root@ip-11-111-111-111 ubuntu]# exit
    [ubuntu@ip-11-111-111-111 ~]$
    
  3. Step 3: creating the public and private keys:

    [ubuntu@ip-11-111-111-111 ~]$ su john
    

    Enter the password you created for “john” in Step 2. Then create a key pair. Remember that the passphrase for key pair should be at least 4 characters.

    [john@ip-11-111-111-111 ubuntu]$ cd /home/john/
    [john@ip-11-111-111-111 ~]$ ssh-keygen -b 1024 -f john -t dsa
    [john@ip-11-111-111-111 ~]$ mkdir .ssh
    [john@ip-11-111-111-111 ~]$ chmod 700 .ssh
    [john@ip-11-111-111-111 ~]$ cat john.pub > .ssh/authorized_keys
    [john@ip-11-111-111-111 ~]$ chmod 600 .ssh/authorized_keys
    [john@ip-11-111-111-111 ~]$ sudo chown john:ubuntu .ssh
    

    In the above step, john is the user we created and ubuntu is the default user group.

    [john@ip-11-111-111-111 ~]$ sudo chown john:ubuntu .ssh/authorized_keys
    
  4. Step 4: now you just need to download the key called “john”. I use scp to download/upload files from EC2, here is how you can do it.

    You will still need to copy the file using ubuntu user, since you only have the key for that user name. So, you will need to move the key to ubuntu folder and chmod it to 777.

    [john@ip-11-111-111-111 ~]$ sudo cp john /home/ubuntu/
    [john@ip-11-111-111-111 ~]$ sudo chmod 777 /home/ubuntu/john
    

    Now come to local machine’s terminal, where you have my_orig_key.pem file and do this:

    $ cd ~/.ssh
    $ scp -i my_orig_key.pem [email protected]:/home/ubuntu/john john
    

    The above command will copy the key “john” to the present working directory on your local machine. Once you have copied the key to your local machine, you should delete “/home/ubuntu/john”, since it’s a private key.

    Now, one your local machine chmod john to 600.

    $ chmod 600 john
    
  5. Step 5: time to test your key:

    $ ssh -i john [email protected]
    

So, in this manner, you can setup multiple users to use one EC2 instance!!

How to check the version of scipy

From the python command prompt:

import scipy
print scipy.__version__

In python 3 you'll need to change it to:

print (scipy.__version__)

Checking if a variable is not nil and not zero in ruby

if discount.nil? || discount == 0
  [do something]
end

Force file download with php using header()

its work for me

$attachment_location = "filePath";
if (file_exists($attachment_location)) {

    header($_SERVER["SERVER_PROTOCOL"] . " 200 OK");
    header("Cache-Control: public"); // needed for internet explorer
    header("Content-Type: application/zip");
    header("Content-Transfer-Encoding: Binary");
    header("Content-Length:".filesize($attachment_location));
    header("Content-Disposition: attachment; filename=filePath");
    readfile($attachment_location);
    die();
} else {
    die("Error: File not found.");
}

How to change the ROOT application?

In Tomcat 7 (under Windows server) I didn't add or edit anything to any configuration file. I just renamed the ROOT folder to something else and renamed my application folder to ROOT and it worked fine.

How can I select rows with most recent timestamp for each key value?

For the sake of completeness, here's another possible solution:

SELECT sensorID,timestamp,sensorField1,sensorField2 
FROM sensorTable s1
WHERE timestamp = (SELECT MAX(timestamp) FROM sensorTable s2 WHERE s1.sensorID = s2.sensorID)
ORDER BY sensorID, timestamp;

Pretty self-explaining I think, but here's more info if you wish, as well as other examples. It's from the MySQL manual, but above query works with every RDBMS (implementing the sql'92 standard).

How do I parse JSON with Objective-C?

With the perspective of the OS X v10.7 and iOS 5 launches, probably the first thing to recommend now is NSJSONSerialization, Apple's supplied JSON parser. Use third-party options only as a fallback if you find that class unavailable at runtime.

So, for example:

NSData *returnedData = ...JSON data, probably from a web request...

// probably check here that returnedData isn't nil; attempting
// NSJSONSerialization with nil data raises an exception, and who
// knows how your third-party library intends to react?

if(NSClassFromString(@"NSJSONSerialization"))
{
    NSError *error = nil;
    id object = [NSJSONSerialization
                      JSONObjectWithData:returnedData
                      options:0
                      error:&error];

    if(error) { /* JSON was malformed, act appropriately here */ }

    // the originating poster wants to deal with dictionaries;
    // assuming you do too then something like this is the first
    // validation step:
    if([object isKindOfClass:[NSDictionary class]])
    {
        NSDictionary *results = object;
        /* proceed with results as you like; the assignment to
        an explicit NSDictionary * is artificial step to get 
        compile-time checking from here on down (and better autocompletion
        when editing). You could have just made object an NSDictionary *
        in the first place but stylistically you might prefer to keep
        the question of type open until it's confirmed */
    }
    else
    {
        /* there's no guarantee that the outermost object in a JSON
        packet will be a dictionary; if we get here then it wasn't,
        so 'object' shouldn't be treated as an NSDictionary; probably
        you need to report a suitable error condition */
    }
}
else
{
    // the user is using iOS 4; we'll need to use a third-party solution.
    // If you don't intend to support iOS 4 then get rid of this entire
    // conditional and just jump straight to
    // NSError *error = nil;
    // [NSJSONSerialization JSONObjectWithData:...
}

can't start MySql in Mac OS 10.6 Snow Leopard

Okay... Finally I could install it! Why? or what I did? well I am not sure. first I downloaded and installed the package (I installed all the files(3) from the disk image) but I couldn't start it. (nor from the preferences panel, nor from the termial)

second I removed it and installed through mac ports.

again, the same thing. could not start it.

Now I deleted it again, installed from the package. (i am not sure if it was the exact same package but I think it is) Only this time I got the package from another site(its a mirror).

the site:

http://www.mmisoftware.co.uk/weblog/2009/08/29/mac-os-x-10-6-snow-leopard-and-mysql/

and the link:

http://mirror.services.wisc.edu/mysql/Downloads/MySQL-5.1/mysql-5.1.37-osx10.5-x86.dmg

1.- install mysql-5-1.37-osx10.5-x86.pkg

2.- install MySQLStartupItem.pkg

3.- install MySQL.prefpanel

And this time is working fine (even the preferences panel!)

Nothing special, I don't know what happened the first two times.

But thank you all. Regards.

Factorial using Recursion in Java

The key point that you missing here is that the variable "result" is a stack variable, and as such it does not get "replaced". To elaborate, every time fact is called, a NEW variable called "result" is created internally in the interpreter and linked to that invocation of the methods. This is in contrast of object fields which linked to the instance of the object and not a specific method call

Excel VBA, error 438 "object doesn't support this property or method

The Error is here

lastrow = wsPOR.Range("A" & Rows.Count).End(xlUp).Row + 1

wsPOR is a workbook and not a worksheet. If you are working with "Sheet1" of that workbook then try this

lastrow = wsPOR.Sheets("Sheet1").Range("A" & _
          wsPOR.Sheets("Sheet1").Rows.Count).End(xlUp).Row + 1

Similarly

wsPOR.Range("A2:G" & lastrow).Select

should be

wsPOR.Sheets("Sheet1").Range("A2:G" & lastrow).Select

How can I retrieve the remote git address of a repo?

If you have the name of the remote, you will be able with git 2.7 (Q4 2015), to use the new git remote get-url command:

git remote get-url origin

(nice pendant of git remote set-url origin <newurl>)

See commit 96f78d3 (16 Sep 2015) by Ben Boeckel (mathstuf).
(Merged by Junio C Hamano -- gitster -- in commit e437cbd, 05 Oct 2015)

remote: add get-url subcommand

Expanding insteadOf is a part of ls-remote --url and there is no way to expand pushInsteadOf as well.
Add a get-url subcommand to be able to query both as well as a way to get all configured urls.

Update Query with INNER JOIN between tables in 2 different databases on 1 server

UPDATE table1 a
 inner join  table2 b on (a.kol1=a.b.kol1...)
SET a.kol1=b.kol1
WHERE 
a.kol1='' ...

for me until the syntax worked -MySQL

Android ListView Divider

This is a workaround, but works for me:

Created res/drawable/divider.xml as follows:

<?xml version="1.0" encoding="UTF-8"?>
<shape
  xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient android:startColor="#ffcdcdcd" android:endColor="#ffcdcdcd" android:angle="270.0" />
</shape>

And in styles.xml for listview item, I added the following lines:

    <item name="android:divider">@drawable/divider</item>
    <item name="android:dividerHeight">1px</item>

Crucial part was to include this 1px setting. Of course, drawable uses gradient (with 1px) and that's not the optimal solution. I tried using stroke but didn't get it to work. (You don't seem to use styles, so just add android:dividerHeight="1px" attribute for the ListView.

Python Remove last char from string and return it

Yes, python strings are immutable and any modification will result in creating a new string. This is how it's mostly done.

So, go ahead with it.

How do I prevent and/or handle a StackOverflowException?

I had a stackoverflow today and i read some of your posts and decided to help out the Garbage Collecter.

I used to have a near infinite loop like this:

    class Foo
    {
        public Foo()
        {
            Go();
        }

        public void Go()
        {
            for (float i = float.MinValue; i < float.MaxValue; i+= 0.000000000000001f)
            {
                byte[] b = new byte[1]; // Causes stackoverflow
            }
        }
    }

Instead let the resource run out of scope like this:

class Foo
{
    public Foo()
    {
        GoHelper();
    }

    public void GoHelper()
    {
        for (float i = float.MinValue; i < float.MaxValue; i+= 0.000000000000001f)
        {
            Go();
        }
    }

    public void Go()
    {
        byte[] b = new byte[1]; // Will get cleaned by GC
    }   // right now
}

It worked for me, hope it helps someone.

How to apply Hovering on html area tag?

for complete this script , the function for draw circle ,

    function drawCircle(coordon)
    {
        var coord = coordon.split(',');

        var c = document.getElementById("myCanvas");
        var hdc = c.getContext("2d");
        hdc.beginPath();

        hdc.arc(coord[0], coord[1], coord[2], 0, 2 * Math.PI);
        hdc.stroke();
    }

"git pull" or "git merge" between master and development branches

my rule of thumb is:

rebase for branches with the same name, merge otherwise.

examples for same names would be master, origin/master and otherRemote/master.

if develop exists only in the local repository, and it is always based on a recent origin/master commit, you should call it master, and work there directly. it simplifies your life, and presents things as they actually are: you are directly developing on the master branch.

if develop is shared, it should not be rebased on master, just merged back into it with --no-ff. you are developing on develop. master and develop have different names, because we want them to be different things, and stay separate. do not make them same with rebase.

Can I change the scroll speed using css or jQuery?

No. Scroll speed is determined by the browser (and usually directly by the settings on the computer/device). CSS and Javascript don't (or shouldn't) have any way to affect system settings.

That being said, there are likely a number of ways you could try to fake a different scroll speed by moving your own content around in such a way as to counteract scrolling. However, I think doing so is a HORRIBLE idea in terms of usability, accessibility, and respect for your users, but I would start by finding events that your target browsers fire that indicate scrolling.

Once you can capture the scroll event (assuming you can), then you would be able to adjust your content dynamically so that the portion you want is visible.

Another approach would be to deal with this in Flash, which does give you at least some level of control over scrolling events.

Bash Script : what does #!/bin/bash mean?

When the first characters in a script are #!, that is called the shebang. If your file starts with #!/path/to/something the standard is to run something and pass the rest of the file to that program as an input.

With that said, the difference between #!/bin/bash, #!/bin/sh, or even #!/bin/zsh is whether the bash, sh, or zsh programs are used to interpret the rest of the file. bash and sh are just different programs, traditionally. On some Linux systems they are two copies of the same program. On other Linux systems, sh is a link to dash, and on traditional Unix systems (Solaris, Irix, etc) bash is usually a completely different program from sh.

Of course, the rest of the line doesn't have to end in sh. It could just as well be #!/usr/bin/python, #!/usr/bin/perl, or even #!/usr/local/bin/my_own_scripting_language.

Multiple left-hand assignment with JavaScript

It is clear by now, that they are not the same. The way to code that is

var var1, var2, var3
var1 = var2 = var3 = 1

And, what about let assigment? Exactly the same as var, don't let the let assigment confuse you because of block scope.

let var1 = var2 = 1 // here var2 belong to the global scope

We could do the following:

let v1, v2, v3
v1 = v2 = v3 = 2

Note: btw, I do not recommend use multiple assignments, not even multiple declarations in the same line.

List distinct values in a vector in R

If the data is actually a factor then you can use the levels() function, e.g.

levels( data$product_code )

If it's not a factor, but it should be, you can convert it to factor first by using the factor() function, e.g.

levels( factor( data$product_code ) )

Another option, as mentioned above, is the unique() function:

unique( data$product_code )

The main difference between the two (when applied to a factor) is that levels will return a character vector in the order of levels, including any levels that are coded but do not occur. unique will return a factor in the order the values first appear, with any non-occurring levels omitted (though still included in levels of the returned factor).

What does string::npos mean in this code?

Value of string::npos is 18446744073709551615. Its a value returned if there is no string found.

How to get current date in jquery?

function createDate() {
            var date    = new Date(),
                yr      = date.getFullYear(),
                month   = date.getMonth()+1,
                day     = date.getDate(),
                todayDate = yr + '-' + month + '-' + day;
            console.log("Today date is :" + todayDate);

What is the best way to get the first letter from a string in Java, returned as a string of length 1?

import java.io.*;
class Initials {

    public static void main(String args[]) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String s;
        char x;
        int l;
        System.out.print("Enter any sentence: ");
        s = br.readLine();
        s = " " + s; //adding a space infront of the inputted sentence or a name
        s = s.toUpperCase(); //converting the sentence into Upper Case (Capital Letters)
        l = s.length(); //finding the length of the sentence
        System.out.print("Output = ");

        for (int i = 0; i < l; i++) {
            x = s.charAt(i); //taking out one character at a time from the sentence
            if (x == ' ') //if the character is a space, printing the next Character along with a fullstop
                System.out.print(s.charAt(i + 1) + ".");
        }
    }
}

python plot normal distribution

I have just come back to this and I had to install scipy as matplotlib.mlab gave me the error message MatplotlibDeprecationWarning: scipy.stats.norm.pdf when trying example above. So the sample is now:

%matplotlib inline
import math
import matplotlib.pyplot as plt
import numpy as np
import scipy.stats


mu = 0
variance = 1
sigma = math.sqrt(variance)
x = np.linspace(mu - 3*sigma, mu + 3*sigma, 100)
plt.plot(x, scipy.stats.norm.pdf(x, mu, sigma))

plt.show()

How to change the pop-up position of the jQuery DatePicker control

Within Jquery.UI, just update the _checkOffset function, so that viewHeight is added to offset.top, before offset is returned.

_checkOffset: function(inst, offset, isFixed) {
    var dpWidth = inst.dpDiv.outerWidth(),
    dpHeight = inst.dpDiv.outerHeight(),
    inputWidth = inst.input ? inst.input.outerWidth() : 0,
    inputHeight = inst.input ? inst.input.outerHeight() : 0,
    viewWidth = document.documentElement.clientWidth + (isFixed ? 0 : $(document).scrollLeft()),
            viewHeight = document.documentElement.clientHeight + (isFixed ? 0 : ($(document).scrollTop()||document.body.scrollTop));
        offset.left -= (this._get(inst, "isRTL") ? (dpWidth - inputWidth) : 0);
        offset.left -= (isFixed && offset.left === inst.input.offset().left) ? $(document).scrollLeft() : 0;
        offset.top -= (isFixed && offset.top === (inst.input.offset().top + inputHeight)) ? ($(document).scrollTop()||document.body.scrollTop) : 0;

        // now check if datepicker is showing outside window viewport - move to a better place if so.
        offset.left -= Math.min(offset.left, (offset.left + dpWidth > viewWidth && viewWidth > dpWidth) ?
            Math.abs(offset.left + dpWidth - viewWidth) : 0);
        offset.top -= Math.min(offset.top, (offset.top + dpHeight > viewHeight && viewHeight > dpHeight) ?
            Math.abs(dpHeight + inputHeight) : 0);
**offset.top = offset.top + viewHeight;**
        return offset;
    },

svn : how to create a branch from certain revision of trunk

Check out the help command:

svn help copy

  -r [--revision] arg      : ARG (some commands also take ARG1:ARG2 range)
                             A revision argument can be one of:
                                NUMBER       revision number
                                '{' DATE '}' revision at start of the date
                                'HEAD'       latest in repository
                                'BASE'       base rev of item's working copy
                                'COMMITTED'  last commit at or before BASE
                                'PREV'       revision just before COMMITTED

To actually specify this on the command line using your example:

svn copy -r123 http://svn.example.com/repos/calc/trunk \
    http://svn.example.com/repos/calc/branches/my-calc-branch

Where 123 would be the revision number in trunk you want to copy. As others have noted, you can also use the @ syntax. I prefer the clearer separation of the revision # from the URL, personally.

As noted in the help, you can replace a revision # with certain words as well:

svn copy -rPREV http://svn.example.com/repos/calc/trunk \
    http://svn.example.com/repos/calc/branches/my-calc-branch

Would copy the "revision just before COMMITTED".

How can I call PHP functions by JavaScript?

I created this library, may be of help to you. MyPHP client and server side library

Example:

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <title>Page Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>

    <!-- include MyPHP.js -->
    <script src="MyPHP.js"></script>

    <!-- use MyPHP class -->
    <script>
        const php = new MyPHP;
        php.auth = 'hashed-key';

        // call a php class
        const phpClass = php.fromClass('Authentication' or 'Moorexa\\Authentication', <pass aguments for constructor here>);

        // call a method in that class
        phpClass.method('login', <arguments>);

        // you can keep chaining here...

        // finally let's call this class
        php.call(phpClass).then((response)=>{
            // returns a promise.
        });

        // calling a function is quite simple also
        php.call('say_hello', <arguments>).then((response)=>{
            // returns a promise
        });

        // if your response has a script tag and you need to update your dom call just call
        php.html(response);

    </script>
</body>
</html>

Javascript: How to check if a string is empty?

This should work:

if (variable === "") {

}

Subset and ggplot2

@agstudy's answer didn't work for me with the latest version of ggplot2, but this did, using maggritr pipes:

ggplot(data=dat)+ 
  geom_line(aes(Value1, Value2, group=ID, colour=ID),
                data = . %>% filter(ID %in% c("P1" , "P3")))

It works because if geom_line sees that data is a function, it will call that function with the inherited version of data and use the output of that function as data.

Spring Boot - inject map from application.yml

You can make it even simplier, if you want to avoid extra structures.

service:
  mappings:
    key1: value1
    key2: value2
@Configuration
@EnableConfigurationProperties
public class ServiceConfigurationProperties {

  @Bean
  @ConfigurationProperties(prefix = "service.mappings")
  public Map<String, String> serviceMappings() {
    return new HashMap<>();
  }

}

And then use it as usual, for example with a constructor:

public class Foo {

  private final Map<String, String> serviceMappings;

  public Foo(Map<String, String> serviceMappings) {
    this.serviceMappings = serviceMappings;
  }

}

PHP order array by date?

Use usort:

usort($array, function($a1, $a2) {
   $v1 = strtotime($a1['date']);
   $v2 = strtotime($a2['date']);
   return $v1 - $v2; // $v2 - $v1 to reverse direction
});

How to add parameters to HttpURLConnection using POST using NameValuePair

Try this:

HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("your url");
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(3);
nameValuePairs.add(new BasicNameValuePair("user_name", "Name"));
nameValuePairs.add(new BasicNameValuePair("pass","Password" ));
nameValuePairs.add(new BasicNameValuePair("user_email","email" ));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);

String ret = EntityUtils.toString(response.getEntity());
Log.v("Util response", ret);

You can add as many nameValuePairs as you need. And don't forget to mention the count in the list.

how to get files from <input type='file' .../> (Indirect) with javascript

Based on Ray Nicholus's answer :

inputElement.onchange = function(event) {
   var fileList = inputElement.files;
   //TODO do something with fileList.  
}

using this will also work :

inputElement.onchange = function(event) {
   var fileList = event.target.files;
   //TODO do something with fileList.  
}

How to Specify Eclipse Proxy Authentication Credentials?

For eclipse Mar1 : - Window > Preferences > General > Network connections. Choose "Manual" from drop down. Double click "HTTP" option and enter the Host, Port, Username and Password. Apply and Finish,,it will work as expected...

Android: How can I print a variable on eclipse console?

System.out.println and Log.d both go to LogCat, not the Console.

How to filter array in subdocument with MongoDB

Use $filter aggregation

Selects a subset of the array to return based on the specified condition. Returns an array with only those elements that match the condition. The returned elements are in the original order.

db.test.aggregate([
    {$match: {"list.a": {$gt:3}}}, // <-- match only the document which have a matching element
    {$project: {
        list: {$filter: {
            input: "$list",
            as: "list",
            cond: {$gt: ["$$list.a", 3]} //<-- filter sub-array based on condition
        }}
    }}
]);

How can I generate random number in specific range in Android?

int min = 65;
int max = 80;

Random r = new Random();
int i1 = r.nextInt(max - min + 1) + min;

Note that nextInt(int max) returns an int between 0 inclusive and max exclusive. Hence the +1.

Cannot create SSPI context

Perhaps you have used Integrated Security = SSPI in connection string. SSPI is used for Trusted connections using Windows Authentication.hence, to work properly in windows authentication, either your system and database server should be in same domain and using same DNS server address, or should be in trusted domain.

if your system and database server is in same domain, Check DNS server address of IPV4 properties in your system's network connection and provide same DNS server being used by database server.

Jackson: how to prevent field serialization

Starting with Jackson 2.6, a property can be marked as read- or write-only. It's simpler than hacking the annotations on both accessors and keeps all the information in one place:

public class User {
    @JsonProperty(access = JsonProperty.Access.WRITE_ONLY)
    private String password;
}

MySql Table Insert if not exist otherwise update

I had a situation where I needed to update or insert on a table according to two fields (both foreign keys) on which I couldn't set a UNIQUE constraint (so INSERT ... ON DUPLICATE KEY UPDATE won't work). Here's what I ended up using:

replace into last_recogs (id, hasher_id, hash_id, last_recog) 
  select l.* from 
    (select id, hasher_id, hash_id, [new_value] from last_recogs 
     where hasher_id in (select id from hashers where name=[hasher_name])
     and hash_id in (select id from hashes where name=[hash_name]) 
     union 
     select 0, m.id, h.id, [new_value] 
     from hashers m cross join hashes h 
     where m.name=[hasher_name] 
     and h.name=[hash_name]) l 
  limit 1;

This example is cribbed from one of my databases, with the input parameters (two names and a number) replaced with [hasher_name], [hash_name], and [new_value]. The nested SELECT...LIMIT 1 pulls the first of either the existing record or a new record (last_recogs.id is an autoincrement primary key) and uses that as the value input into the REPLACE INTO.

Installed Java 7 on Mac OS X but Terminal is still using version 6

Since i have not faced this issue , I am taking a hunch --

Can you please try this :

Where does the soft link "java_home" point to :

ls -lrt /usr/libexec/java_home

Output : (Stunted) lrwxr-xr-x java_home -> /System/Library/Frameworks/JavaVM.framework/Versions/Current/Commands/java_home

**ls -lrt /System/Library/Frameworks/JavaVM.framework/Versions My MAC Produces the following :

 lrwxr-xr-x CurrentJDK ->
 /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents**

 lrwxr-xr-x   Current -> A
 lrwxr-xr-x  1 root  wheel   10 Oct 18 14:39 1.6.0 -> CurrentJDK
 lrwxr-xr-x  1 root  wheel   10 Oct 18 14:39 1.6 -> CurrentJDK
 lrwxr-xr-x  1 root  wheel   10 Oct 18 14:39 1.5.0 -> CurrentJDK
 lrwxr-xr-x  1 root  wheel   10 Oct 18 14:39 1.5 -> CurrentJDK
 lrwxr-xr-x  1 root  wheel   10 Oct 18 14:39 1.4.2 -> CurrentJDK
 lrwxr-xr-x  1 root  wheel   10 Oct 18 14:39 1.4 -> CurrentJDK

Based on this , we might get a hint to proceed further ?

How do I make a C++ macro behave like a function?

C++11 brought us lambdas, which can be incredibly useful in this situation:

#define MACRO(X,Y)                              \
    [&](x_, y_) {                               \
        cout << "1st arg is:" << x_ << endl;    \
        cout << "2nd arg is:" << y_ << endl;    \
        cout << "Sum is:" << (x_ + y_) << endl; \
    }((X), (Y))

You keep the generative power of macros, but have a comfy scope from which you can return whatever you want (including void). Additionally, the issue of evaluating macro parameters multiple times is avoided.

Create a hexadecimal colour based on a string with JavaScript

Yet another solution for random colors:

function colorize(str) {
    for (var i = 0, hash = 0; i < str.length; hash = str.charCodeAt(i++) + ((hash << 5) - hash));
    color = Math.floor(Math.abs((Math.sin(hash) * 10000) % 1 * 16777216)).toString(16);
    return '#' + Array(6 - color.length + 1).join('0') + color;
}

It's a mixed of things that does the job for me. I used JFreeman Hash function (also an answer in this thread) and Asykäri pseudo random function from here and some padding and math from myself.

I doubt the function produces evenly distributed colors, though it looks nice and does that what it should do.

Should image size be defined in the img tag height/width attributes or in CSS?

I'm using contentEditable to allow rich text editing in my app. I don't know how it slips through, but when an image is inserted, and then resized (by dragging the anchors on its side), it generates something like this:

  <img style="width:55px;height:55px" width="100" height="100" src="pic.gif" border=0/>

(subsequent testing shown that inserted images did not contain this "rogue" style attr+param).

When rendered by the browser (IE7), the width and height in the style overrides the img width/height param (so the image is shown like how I wanted it.. resized to 55px x 55px. So everything went well so it seems.

When I output the page to a ms-word document via setting the mime type application/msword or pasting the browser rendering to msword document, all the images reverted back to its default size. I finally found out that msword is discarding the style and using the img width and height tag (which has the value of the original image size).

Took me a while to found this out. Anyway... I've coded a javascript function to traverse all tags and "transferring" the img style.width and style.height values into the img.width and img.height, then clearing both the values in style, before I proceed saving this piece of html/richtext data into the database.

cheers.

opps.. my answer is.. no. leave both attributes directly under img, rather than style.

How best to read a File into List<string>

Don't store it if possible. Just read through it if you are memory constrained. You can use a StreamReader:

using (var reader = new StreamReader("file.txt"))
{
    var line = reader.ReadLine();
    // process line here
}

This can be wrapped in a method which yields strings per line read if you want to use LINQ.

Jquery bind double click and single click separately

The solution given from "Nott Responding" seems to fire both events, click and dblclick when doubleclicked. However I think it points in the right direction.

I did a small change, this is the result :

$("#clickMe").click(function (e) {
    var $this = $(this);
    if ($this.hasClass('clicked')){
        $this.removeClass('clicked'); 
        alert("Double click");
        //here is your code for double click
    }else{
        $this.addClass('clicked');
        setTimeout(function() { 
            if ($this.hasClass('clicked')){
                $this.removeClass('clicked'); 
                alert("Just one click!");
                //your code for single click              
            }
        }, 500);          
    }
});

Try it

http://jsfiddle.net/calterras/xmmo3esg/

Parse date string and change format

>>> from_date="Mon Feb 15 2010"
>>> import time                
>>> conv=time.strptime(from_date,"%a %b %d %Y")
>>> time.strftime("%d/%m/%Y",conv)
'15/02/2010'

How I can filter a Datatable?

You can use DataView.

DataView dv = new DataView(yourDatatable);
dv.RowFilter = "query"; // query example = "id = 10"


http://www.csharp-examples.net/dataview-rowfilter/

How to edit the size of the submit button on a form?

You can change height and width with css:

#search {
     height: 100px;
     width: 400px;
}

It's worth pointing out that safari on OSX ignores most input button styles, however.

How to multiply duration by integer?

It's nice that Go has a Duration type -- having explicitly defined units can prevent real-world problems.

And because of Go's strict type rules, you can't multiply a Duration by an integer -- you must use a cast in order to multiply common types.

/*
MultiplyDuration Hide semantically invalid duration math behind a function
*/
func MultiplyDuration(factor int64, d time.Duration) time.Duration {
    return time.Duration(factor) * d        // method 1 -- multiply in 'Duration'
 // return time.Duration(factor * int64(d)) // method 2 -- multiply in 'int64'
}

The official documentation demonstrates using method #1:

To convert an integer number of units to a Duration, multiply:

seconds := 10
fmt.Print(time.Duration(seconds)*time.Second) // prints 10s

But, of course, multiplying a duration by a duration should not produce a duration -- that's nonsensical on the face of it. Case in point, 5 milliseconds times 5 milliseconds produces 6h56m40s. Attempting to square 5 seconds results in an overflow (and won't even compile if done with constants).

By the way, the int64 representation of Duration in nanoseconds "limits the largest representable duration to approximately 290 years", and this indicates that Duration, like int64, is treated as a signed value: (1<<(64-1))/(1e9*60*60*24*365.25) ~= 292, and that's exactly how it is implemented:

// A Duration represents the elapsed time between two instants
// as an int64 nanosecond count. The representation limits the
// largest representable duration to approximately 290 years.
type Duration int64

So, because we know that the underlying representation of Duration is an int64, performing the cast between int64 and Duration is a sensible NO-OP -- required only to satisfy language rules about mixing types, and it has no effect on the subsequent multiplication operation.

If you don't like the the casting for reasons of purity, bury it in a function call as I have shown above.

java.lang.ClassCastException: java.lang.Long cannot be cast to java.lang.Integer in java 1.6

The number of results can (theoretically) be greater than the range of an integer. I would refactor the code and work with the returned long value instead.

How can I slice an ArrayList out of an ArrayList in Java?

In Java, it is good practice to use interface types rather than concrete classes in APIs.

Your problem is that you are using ArrayList (probably in lots of places) where you should really be using List. As a result you created problems for yourself with an unnecessary constraint that the list is an ArrayList.

This is what your code should look like:

List input = new ArrayList(...);

public void doSomething(List input) {
   List inputA = input.subList(0, input.size()/2);
   ...
}

this.doSomething(input);

Your proposed "solution" to the problem was/is this:

new ArrayList(input.subList(0, input.size()/2))

That works by making a copy of the sublist. It is not a slice in the normal sense. Furthermore, if the sublist is big, then making the copy will be expensive.


If you are constrained by APIs that you cannot change, such that you have to declare inputA as an ArrayList, you might be able to implement a custom subclass of ArrayList in which the subList method returns a subclass of ArrayList. However:

  1. It would be a lot of work to design, implement and test.
  2. You have now added significant new class to your code base, possibly with dependencies on undocumented aspects (and therefore "subject to change") aspects of the ArrayList class.
  3. You would need to change relevant places in your codebase where you are creating ArrayList instances to create instances of your subclass instead.

The "copy the array" solution is more practical ... bearing in mind that these are not true slices.

How do I convert a IPython Notebook into a Python file via commandline?

Jupytext is nice to have in your toolchain for such conversions. It allows not only conversion from a notebook to a script, but you can go back again from the script to notebook as well. And even have that notebook produced in executed form.

jupytext --to py notebook.ipynb                 # convert notebook.ipynb to a .py file
jupytext --to notebook notebook.py              # convert notebook.py to an .ipynb file with no outputs
jupytext --to notebook --execute notebook.py    # convert notebook.py to an .ipynb file and run it 

How do I show the value of a #define at compile-time?

In Microsoft C/C++, you can use the built-in _CRT_STRINGIZE() to print constants. Many of my stdafx.h files contain some combination of these:

#pragma message("_MSC_VER      is " _CRT_STRINGIZE(_MSC_VER))
#pragma message("_MFC_VER      is " _CRT_STRINGIZE(_MFC_VER))
#pragma message("_ATL_VER      is " _CRT_STRINGIZE(_ATL_VER))
#pragma message("WINVER        is " _CRT_STRINGIZE(WINVER))
#pragma message("_WIN32_WINNT  is " _CRT_STRINGIZE(_WIN32_WINNT))
#pragma message("_WIN32_IE     is " _CRT_STRINGIZE(_WIN32_IE))
#pragma message("NTDDI_VERSION is " _CRT_STRINGIZE(NTDDI_VERSION)) 

and outputs something like this:

_MSC_VER      is 1915
_MFC_VER      is 0x0E00
_ATL_VER      is 0x0E00
WINVER        is 0x0600
_WIN32_WINNT  is 0x0600
_WIN32_IE     is 0x0700
NTDDI_VERSION is 0x06000000

How do you develop Java Servlets using Eclipse?

You need to install a plugin, There is a free one from the eclipse foundation called the Web Tools Platform. It has all the development functionality that you'll need.

You can get the Java EE Edition of eclipse with has it pre-installed.

To create and run your first servlet:

  1. New... Project... Dynamic Web Project.
  2. Right click the project... New Servlet.
  3. Write some code in the doGet() method.
  4. Find the servers view in the Java EE perspective, it's usually one of the tabs at the bottom.
  5. Right click in there and select new Server.
  6. Select Tomcat X.X and a wizard will point you to finding the installation.
  7. Right click the server you just created and select Add and Remove... and add your created web project.
  8. Right click your servlet and select Run > Run on Server...

That should do it for you. You can use ant to build here if that's what you'd like but eclipse will actually do the build and automatically deploy the changes to the server. With Tomcat you might have to restart it every now and again depending on the change.

Can a foreign key be NULL and/or duplicate?

it depends on what role this foreign key plays in your relation.

  1. if this foreign key is also a key attribute in your relation, then it can't be NULL
  2. if this foreign key is a normal attribute in your relation, then it can be NULL.

Deserializing JSON to .NET object using Newtonsoft (or LINQ to JSON maybe?)

I like this method:

using Newtonsoft.Json.Linq;
// jsonString is your JSON-formatted string
JObject jsonObj = JObject.Parse(jsonString);
Dictionary<string, object> dictObj = jsonObj.ToObject<Dictionary<string, object>>();

You can now access anything you want using the dictObj as a dictionary. You can also use Dictionary<string, string> if you prefer to get the values as strings.

You can use this same method to cast as any kind of .NET object.

Laravel Escaping All HTML in Blade Template

Change your syntax from {{ }} to {!! !!}.

As The Alpha said in a comment above (not an answer so I thought I'd post), in Laravel 5, the {{ }} (previously non-escaped output syntax) has changed to {!! !!}. Replace {{ }} with {!! !!} and it should work.

how to read a long multiline string line by line in python

What about using .splitlines()?

for line in textData.splitlines():
    print(line)
    lineResult = libLAPFF.parseLine(line)

Disable Drag and Drop on HTML elements?

With jQuery it will be something like that:

$(document).ready(function() {
  $('#yourDiv').on('mousedown', function(e) {
      e.preventDefault();
  });
});

In my case I wanted to disable the user from drop text in the inputs so I used "drop" instead "mousedown".

$(document).ready(function() {
  $('input').on('drop', function(event) {
    event.preventDefault();
  });
});

Instead event.preventDefault() you can return false. Here's the difference.

And the code:

$(document).ready(function() {
  $('input').on('drop', function() {
    return false;
  });
});

Illegal access: this web application instance has been stopped already

In short: this happens likely when you are hot-deploying webapps. For instance, your ide+development server hot-deploys a war again. Threads, that have been created previously are still running. But meanwhile their classloader/context is invalid and faces the IllegalAccessException / IllegalStateException becouse its orgininating webapp (the former runtime-environment) has been redeployed.

So, as states here, a restart does not permanently resolve this issue. Instead, it is better to find/implement a managed Thread Pool, s.th. like this to handle the termination of threads appropriately. In JavaEE you will use these ManagedThreadExeuctorServices. A similar opinion and reference here.

Examples for this are the EvictorThread of Apache Commons Pool, that "cleans" pooled instances according to the pool's configuration (max idle etc.).

How to make a movie out of images in python

I use the ffmpeg-python binding. You can find more information here.

import ffmpeg
(
    ffmpeg
    .input('/path/to/jpegs/*.jpg', pattern_type='glob', framerate=25)
    .output('movie.mp4')
    .run()
)

Visual Studio keyboard shortcut to automatically add the needed 'using' statement

It's ctrl + . when, for example, you try to type List you need to type < at the end and press ctrl + . for it to work.

Object of custom type as dictionary key

An alternative in Python 2.6 or above is to use collections.namedtuple() -- it saves you writing any special methods:

from collections import namedtuple
MyThingBase = namedtuple("MyThingBase", ["name", "location"])
class MyThing(MyThingBase):
    def __new__(cls, name, location, length):
        obj = MyThingBase.__new__(cls, name, location)
        obj.length = length
        return obj

a = MyThing("a", "here", 10)
b = MyThing("a", "here", 20)
c = MyThing("c", "there", 10)
a == b
# True
hash(a) == hash(b)
# True
a == c
# False

Why does cURL return error "(23) Failed writing body"?

I had the same error but from different reason. In my case I had (tmpfs) partition with only 1GB space and I was downloading big file which finally filled all memory on that partition and I got the same error as you.

AngularJS - Trigger when radio button is selected

There are at least 2 different methods of invoking functions on radio button selection:

1) Using ng-change directive:

<input type="radio" ng-model="value" value="foo" ng-change='newValue(value)'>

and then, in a controller:

$scope.newValue = function(value) {
     console.log(value);
}

Here is the jsFiddle: http://jsfiddle.net/ZPcSe/5/

2) Watching the model for changes. This doesn't require anything special on the input level:

<input type="radio" ng-model="value" value="foo">

but in a controller one would have:

$scope.$watch('value', function(value) {
       console.log(value);
 });

And the jsFiddle: http://jsfiddle.net/vDTRp/2/

Knowing more about your the use case would help to propose an adequate solution.

jQuery - disable selected options

This will disable/enable the options when you select/remove them, respectively.

$("#theSelect").change(function(){          
    var value = $(this).val();
    if (value === '') return;
    var theDiv = $(".is" + value);

    var option = $("option[value='" + value + "']", this);
    option.attr("disabled","disabled");

    theDiv.slideDown().removeClass("hidden");
    theDiv.find('a').data("option",option);
});


$("div a.remove").click(function () {     
    $(this).parent().slideUp(function() { $(this).addClass("hidden"); });
    $(this).data("option").removeAttr('disabled');
});

Demo: http://jsfiddle.net/AaXkd/

What is the difference between char, nchar, varchar, and nvarchar in SQL Server?

  • nchar is fixed-length and can hold unicode characters. it uses two bytes storage per character.

  • varchar is of variable length and cannot hold unicode characters. it uses one byte storage per character.

Maximum number of records in a MySQL database table

Row Size Limits

The maximum row size for a given table is determined by several factors:
  • The internal representation of a MySQL table has a maximum row size limit of 65,535 bytes, even if the storage engine is capable of supporting larger rows. BLOB and TEXT columns only contribute 9 to 12 bytes toward the row size limit because their contents are stored separately from the rest of the row.

  • The maximum row size for an InnoDB table, which applies to data stored locally within a database page, is slightly less than half a page. For example, the maximum row size is slightly less than 8KB for the default 16KB InnoDB page size, which is defined by the innodb_page_size configuration option. “Limits on InnoDB Tables”.

  • If a row containing variable-length columns exceeds the InnoDB maximum row size, InnoDB selects variable-length columns for external off-page storage until the row fits within the InnoDB row size limit. The amount of data stored locally for variable-length columns that are stored off-page differs by row format. For more information, see “InnoDB Row Storage and Row Formats”.
  • Different storage formats use different amounts of page header and trailer data, which affects the amount of storage available for rows.

Getting output of system() calls in Ruby

Another way is:

f = open("|ls")
foo = f.read()

Note that's the "pipe" character before "ls" in open. This can also be used to feed data into the programs standard input as well as reading its standard output.

Rails - controller action name to string

Rails 2.X: @controller.action_name

Rails 3.1.X: controller.action_name, action_name

Rails 4.X: action_name

git pull keeping local changes

If you have a file in your repo that it is supposed to be customized by most pullers, then rename the file to something like config.php.template and add config.php to your .gitignore.

Gradle Build Android Project "Could not resolve all dependencies" error

I had this message in Android Studio 2.1.1 in the Gradle Build tab. I installed a lot of files from the SDK Manager but it did not help.

I needed to click the next tab "Gradle Sync". There was a link "Install Repository and sync project" which installed the "Android Support Repository".

Center HTML Input Text Field Placeholder

By using the code snippet below, you are selecting the placeholder inside your input, and any code placed inside will affect only the placeholder.

input::-webkit-input-placeholder {
      text-align: center
}

Finding common rows (intersection) in two Pandas dataframes

My understanding is that this question is better answered over in this post.

But briefly, the answer to the OP with this method is simply:

s1 = pd.merge(df1, df2, how='inner', on=['user_id'])

Which gives s1 with 5 columns: user_id and the other two columns from each of df1 and df2.

Register DLL file on Windows Server 2008 R2

Error 0x80040154 is COM's REGDB_E_CLASSNOTREG, which means "Class not registered". Basically, a COM class is not declared in the installation registry.

If you get this error when trying to register a DLL, it may be possible that the registration code for this DLL is trying to instantiate another COM server (DLL or EXE) which is missing or not registered on this installation.

If you don't have access to the original DLL source, I would suggest to use SysInternal's Process Monitor tool to track COM registry lookups (there use to be a more simple RegMon tool but it may not work any more).

You should put a filter on the working process (here: Regsvr32.exe) to only capture what's interesting. Then you should look for queries on HKEY_CLASSES_ROOT\[a progid, a string] that fail (with the NAME_NOT_FOUND error for example), or queries on HKEY_CLASSES_ROOT\CLSID\[a guid] that fail.

PS: Unfortunately, there may be many thing that seem to fail on a perfectly working Windows system, so you'll have to study all errors carefully. Good luck :-)

how to check for datatype in node js- specifically for integer

i have used it in this way and its working fine

quantity=prompt("Please enter the quantity","1");
quantity=parseInt(quantity);
if (!isNaN( quantity ))
{
    totalAmount=itemPrice*quantity;

}
return totalAmount;

GIT_DISCOVERY_ACROSS_FILESYSTEM problem when working with terminal and MacFusion

Try a different protocol. git:// may have problems from your firewall, for example; try a git clone with https: instead.

CREATE DATABASE permission denied in database 'master' (EF code-first)

I'm going to add what I've had to do, as it is an amalgamation of the above. I'm using Code First, tried using 'create-database' but got the error in the title. Closed and re-opened (as Admin this time) - command not recognised but 'update-database' was so used that. Same error.

Here are the steps I took to resolve it:

1) Opened SQL Server Management Studio and created a database "Videos"

2) Opened Server Explorer in VS2013 (under 'View') and connected to the database.

3) Right clicked on the connection -> properties, and grabbed the connection string.

4) In the web.config I added the connection string

   <connectionStrings>
<add name="DefaultConnection"
  connectionString="Data Source=MyMachine;Initial Catalog=Videos;Integrated Security=True" providerName="System.Data.SqlClient"
  />
  </connectionStrings>

5) Where I set up the context, I need to reference DefaultConnection:

using System.Data.Entity;

namespace Videos.Models
{
public class VideoDb : DbContext
{
    public VideoDb()
        : base("name=DefaultConnection")
    {

    }

    public DbSet<Video> Videos { get; set; }
}
}

6) In Package Manager console run 'update-database' to create the table(s).

Remember you can use Seed() to insert values when creating, in Configuration.cs:

        protected override void Seed(Videos.Models.VideoDb context)
        {
        context.Videos.AddOrUpdate(v => v.Title,
            new Video() { Title = "MyTitle1", Length = 150 },
            new Video() { Title = "MyTitle2", Length = 270 }
            );

        context.SaveChanges();
        }

add class with JavaScript

I like to use a custom "foreach" function of sorts for these kinds of things:

function Each( objs, func )
{
    if ( objs.length ) for ( var i = 0, ol = objs.length, v = objs[ 0 ]; i < ol && func( v, i ) !== false; v = objs[ ++i ] );
    else for ( var p in objs ) if ( func( objs[ p ], p ) === false ) break;
}

(Can't remember where I found the above function, but it has been quite useful.)

Then after fetching your objects (to elements in this example) just do

Each( elements, function( element )
{
    element.addEventListener( "mouseover", function()
    {
        element.classList.add( "active" );
        //element.setAttribute( "class", "active" );
        element.setAttribute( "src", "newsource" );
    });

    // Remove class and new src after "mouseover" ends, if you wish.
    element.addEventListener( "mouseout", function()
    {
        element.classList.remove( "active" );
        element.setAttribute( "src", "originalsource" );
    });
});

classList is a simple way for handling elements' classes. Just needs a shim for a few browsers. If you must use setAttribute you must remember that whatever is set with it will overwrite the previous values.

EDIT: Forgot to mention that you need to use attachEvent instead of addEventListener on some IE versions. Test with if ( document.addEventListener ) {...}.

Unzip files programmatically in .net

You can do it all within .NET 3.5 using DeflateStream. The thing lacking in .NET 3.5 is the ability to process the file header sections that are used to organize the zipped files. PKWare has published this information, which you can use to process the zip file after you create the structures that are used. It is not particularly onerous, and it a good practice in tool building without using 3rd party code.

It isn't a one line answer, but it is completely doable if you are willing and able to take the time yourself. I wrote a class to do this in a couple of hours and what I got from that is the ability to zip and unzip files using .NET 3.5 only.

Determining type of an object in ruby

variable_name.class

Here variable name is "a" a.class

How do I align a number like this in C?

Try converting to a string and then use "%4.4s" as the format specifier. This makes it a fixed width format.

Entity Framework - Linq query with order by and group by

It's method syntax (which I find easier to read) but this might do it

Updated post comment

Use .FirstOrDefault() instead of .First()

With regard to the dates average, you may have to drop that ordering for the moment as I am unable to get to an IDE at the moment

var groupByReference = context.Measurements
                              .GroupBy(m => m.Reference)
                              .Select(g => new {Creation = g.FirstOrDefault().CreationTime, 
//                                              Avg = g.Average(m => m.CreationTime.Ticks),
                                                Items = g })
                              .OrderBy(x => x.Creation)
//                            .ThenBy(x => x.Avg)
                              .Take(numOfEntries)
                              .ToList();

How to remove all leading zeroes in a string

Similar to another suggestion, except will not obliterate actual zero:

if (ltrim($str, '0') != '') {
    $str = ltrim($str, '0');
} else {
    $str = '0';
}

Or as was suggested (as of PHP 5.3), shorthand ternary operator can be used:

$str = ltrim($str, '0') ?: '0'; 

Save matplotlib file to a directory

In addition to the answers already given, if you want to create a new directory, you could use this function:

def mkdir_p(mypath):
    '''Creates a directory. equivalent to using mkdir -p on the command line'''

    from errno import EEXIST
    from os import makedirs,path

    try:
        makedirs(mypath)
    except OSError as exc: # Python >2.5
        if exc.errno == EEXIST and path.isdir(mypath):
            pass
        else: raise

and then:

import matplotlib
import matplotlib.pyplot as plt

fig = plt.figure()
ax = fig.add_subplot(111)
ax.plot(range(100))

# Create new directory
output_dir = "some/new/directory"
mkdir_p(output_dir)

fig.savefig('{}/graph.png'.format(output_dir))

How add class='active' to html menu with php

You could use this PHP, hope it helps.

<?php if(basename($_SERVER['PHP_SELF'], '.php') == 'home' ) { ?> class="active" <?php } else { ?> <?php }?>

So a list would be like the below.

<ul>
  <li <?php if( basename($_SERVER['PHP_SELF'], '.php') == 'home' ) { ?> class="active" <?php } else { ?> <?php }?>><a href="home"><i class="fa fa-dashboard"></i> <span>Home</span></a></li>
  <li <?php if( basename($_SERVER['PHP_SELF'], '.php') == 'listings' ) { ?> class="active" <?php } else { ?> <?php }?>><a href="other"><i class="fa fa-th-list"></i> <span>Other</span></a></li>
</ul>

CURLOPT_RETURNTRANSFER set to true doesnt work on hosting server

If it works fine on your local environment, probably your remote server's IP is being blocked by the server at the target URL you've set for cURL to use. You need to verify that your remote server is allowed to access the URL you've set for CURLOPT_URL.

How do I convert an enum to a list in C#?

List <SomeEnum> theList = Enum.GetValues(typeof(SomeEnum)).Cast<SomeEnum>().ToList();

How do I unset an element in an array in javascript?

If you know the key name simply do like this:

delete array['key_name']

Error: Expression must have integral or unscoped enum type

Your variable size is declared as: float size;

You can't use a floating point variable as the size of an array - it needs to be an integer value.

You could cast it to convert to an integer:

float *temp = new float[(int)size];

Your other problem is likely because you're writing outside of the bounds of the array:

   float *temp = new float[size];

    //Getting input from the user
    for (int x = 1; x <= size; x++){
        cout << "Enter temperature " << x << ": ";

        // cin >> temp[x];
        // This should be:
        cin >> temp[x - 1];
    }

Arrays are zero based in C++, so this is going to write beyond the end and never write the first element in your original code.

Can my enums have friendly names?

You could use the Description attribute, as Yuriy suggested. The following extension method makes it easy to get the description for a given value of the enum:

public static string GetDescription(this Enum value)
{
    Type type = value.GetType();
    string name = Enum.GetName(type, value);
    if (name != null)
    {
        FieldInfo field = type.GetField(name);
        if (field != null)
        {
            DescriptionAttribute attr = 
                   Attribute.GetCustomAttribute(field, 
                     typeof(DescriptionAttribute)) as DescriptionAttribute;
            if (attr != null)
            {
                return attr.Description;
            }
        }
    }
    return null;
}

You can use it like this:

public enum MyEnum
{
    [Description("Description for Foo")]
    Foo,
    [Description("Description for Bar")]
    Bar
}

MyEnum x = MyEnum.Foo;
string description = x.GetDescription();

What is a NoReverseMatch error, and how do I fix it?

It may be that it's not loading the template you expect. I added a new class that inherited from UpdateView - I thought it would automatically pick the template from what I named my class, but it actually loaded it based on the model property on the class, which resulted in another (wrong) template being loaded. Once I explicitly set template_name for the new class, it worked fine.

How to uninstall Golang?

I just have to answer here after reading such super-basic advice in the other answers.

For MacOS the default paths are:

  1. /user/bracicot/go (working dir)
  2. /usr/local/go (install dir)

When uninstalling remove both directories.
If you've installed manually obviously these directories may be in other places.

One script I came across installed to /usr/local/.go/ a hidden folder because of permissioning... this could trip you up.

In terminal check:

echo $GOPATH
echo $GOROOT
#and
go version

For me after deleting all go folders I was still getting a go version.

Digging through my system path echo $PATH

/Users/bracicot/google-cloud-sdk/bin:/usr/local/bin:

revealed some places to check for still-existing go files such as /usr/local/bin

Another user mentioned: /etc/paths.d/go

You may also want to remove GOPATH and GOROOT environment variables.
Check .zshsrc and or .bash_profile.
Or you can unset GOPATH and unset GOROOT

Update style of a component onScroll in React.js

You should bind the listener in componentDidMount, that way it's only created once. You should be able to store the style in state, the listener was probably the cause of performance issues.

Something like this:

componentDidMount: function() {
    window.addEventListener('scroll', this.handleScroll);
},

componentWillUnmount: function() {
    window.removeEventListener('scroll', this.handleScroll);
},

handleScroll: function(event) {
    let scrollTop = event.srcElement.body.scrollTop,
        itemTranslate = Math.min(0, scrollTop/3 - 60);

    this.setState({
      transform: itemTranslate
    });
},

Instagram API - How can I retrieve the list of people a user is following on Instagram

The REST API of Instagram has been discontinued. But you can use GraphQL to get the desired data. Here you can find an overview: https://developers.facebook.com/docs/instagram-api

Two submit buttons in one form

This is extremely easy to test

<form action="" method="get">

<input type="submit" name="sb" value="One">
<input type="submit" name="sb" value="Two">
<input type="submit" name="sb" value="Three">

</form>

Just put that in an HTML page, click the buttons, and look at the URL

How should I copy Strings in Java?

String str1="this is a string";
String str2=str1.clone();

How about copy like this? I think to get a new copy is better, so that the data of str1 won't be affected when str2 is reference and modified in futher action.

SQL Insert Multiple Rows

You can use UNION All clause to perform multiple insert in a table.

ex:

INSERT INTO dbo.MyTable (ID, Name)
SELECT 123, 'Timmy'
UNION ALL
SELECT 124, 'Jonny'
UNION ALL
SELECT 125, 'Sally'

Check here

Cannot find runtime 'node' on PATH - Visual Studio Code and Node.js

I also encountered this issue. Did the following and it got fixed.

  1. Open your computer terminal (not VSCode terminal) and type node --version to ensure you have node installed. If not, then install node using nvm.
  2. Then head to your bash file (eg .bashrc, .bash_profile, .profile) and add the PATH:
 [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"  # This loads nvm 
 [ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion"
  1. If you have multiple bash files, you ensure to add the PATH to all of them.
  2. Restart your VSCode terminal and it should be fine.

WCF error - There was no endpoint listening at

in my case

my service has function to Upload Files

and this error just shown up on trying to upload Big Files

so I found this answer to Increase maxRequestLength to needed value in web.config

and problem solved

if you don't make any upload or download operations maybe this answer will not help you

.NET code to send ZPL to Zebra printers

I use the combo of these two

    Private Sub sendData(ByVal zpl As String)
    Dim ns As System.Net.Sockets.NetworkStream = Nothing
    Dim socket As System.Net.Sockets.Socket = Nothing
    Dim printerIP As Net.IPEndPoint = Nothing
    Dim toSend As Byte()

    Try
        If printerIP Is Nothing Then
            'set the IP address
            printerIP = New Net.IPEndPoint(IPAddress.Parse(IP_ADDRESS), 9100)
        End If

        'Create a TCP socket
        socket = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
        'Connect to the printer based on the IP address
        socket.Connect(printerIP)
        'create a new network stream based on the socket connection
        ns = New NetworkStream(socket)

        'convert the zpl command to a byte array
        toSend = System.Text.Encoding.ASCII.GetBytes(zpl)

        'send the zpl byte array over the networkstream to the connected printer
        ns.Write(toSend, 0, toSend.Length)

    Catch ex As Exception
        MessageBox.Show(ex.Message, "Cable Printer", MessageBoxButtons.OKCancel, MessageBoxIcon.Error)
    Finally
        'close the networkstream and then the socket
        If Not ns Is Nothing Then
            ns.Close()
        End If

        If Not socket Is Nothing Then
            socket.Close()
        End If
    End Try
End Sub


Private Function createString() As String
    Dim command As String

    command = "^XA"
    command += "^LH20,25"

    If rdoSmall.Checked = True Then
        command += "^FO1,30^A0,N,25,25^FD"
    ElseIf rdoNormal.Checked = True Then
        command += "^FO1,30^A0,N,35,35^FD"
    Else
        command += "^FO1,30^A0,N,50,50^FD"
    End If

    command += txtInput.Text
    command += "^FS"
    command += "^XZ"

    Return command

End Function

EOFError: EOF when reading a line

width, height = map(int, input().split())
def rectanglePerimeter(width, height):
   return ((width + height)*2)
print(rectanglePerimeter(width, height))

Running it like this produces:

% echo "1 2" | test.py
6

I suspect IDLE is simply passing a single string to your script. The first input() is slurping the entire string. Notice what happens if you put some print statements in after the calls to input():

width = input()
print(width)
height = input()
print(height)

Running echo "1 2" | test.py produces

1 2
Traceback (most recent call last):
  File "/home/unutbu/pybin/test.py", line 5, in <module>
    height = input()
EOFError: EOF when reading a line

Notice the first print statement prints the entire string '1 2'. The second call to input() raises the EOFError (end-of-file error).

So a simple pipe such as the one I used only allows you to pass one string. Thus you can only call input() once. You must then process this string, split it on whitespace, and convert the string fragments to ints yourself. That is what

width, height = map(int, input().split())

does.

Note, there are other ways to pass input to your program. If you had run test.py in a terminal, then you could have typed 1 and 2 separately with no problem. Or, you could have written a program with pexpect to simulate a terminal, passing 1 and 2 programmatically. Or, you could use argparse to pass arguments on the command line, allowing you to call your program with

test.py 1 2

line breaks in a textarea

I'm not sure this is possible but you should try <pre><textarea> ... </textarea></pre>

Using gradle to find dependency tree

Often the complete testImplementation, implementation, and androidTestImplementation dependency graph is too much to examine together. If you merely want the implementation dependency graph you can use:

./gradlew app:dependencies --configuration implementation

Source: Gradle docs section 4.7.6

Note: compile has been deprecated in more recent versions of Gradle and in more recent versions you are advised to shift all of your compile dependencies to implementation. Please see this answer here

Favorite Visual Studio keyboard shortcuts

Well, if you're really

always up for leaving my hands on the keyboard and away from the mouse!

Than you should go here

It's not really my favorite, it's just everything!

A shortcut a day will keep the mouse away.

How do I pre-populate a jQuery Datepicker textbox with today's date?

This works better for me as sometimes I have troubles calling .datepicker('setDate', new Date()); as it messes if if i have the datepicker already configured with parameters.

$("#myDateText").val(moment(new Date()).format('DD/MM/YYYY'));

PostgreSQL INSERT ON CONFLICT UPDATE (upsert) use all excluded values

Postgres hasn't implemented an equivalent to INSERT OR REPLACE. From the ON CONFLICT docs (emphasis mine):

It can be either DO NOTHING, or a DO UPDATE clause specifying the exact details of the UPDATE action to be performed in case of a conflict.

Though it doesn't give you shorthand for replacement, ON CONFLICT DO UPDATE applies more generally, since it lets you set new values based on preexisting data. For example:

INSERT INTO users (id, level)
VALUES (1, 0)
ON CONFLICT (id) DO UPDATE
SET level = users.level + 1;

Best way to pass parameters to jQuery's .load()

As Davide Gualano has been told. This one

$("#myDiv").load("myScript.php?var=x&var2=y&var3=z")

use GET method for sending the request, and this one

$("#myDiv").load("myScript.php", {var:x, var2:y, var3:z})

use POST method for sending the request. But any limitation that is applied to each method (post/get) is applied to the alternative usages that has been mentioned in the question.

For example: url length limits the amount of sending data in GET method.

How can I use a Python script in the command line without cd-ing to its directory? Is it the PYTHONPATH?

You're confusing PATH and PYTHONPATH. You need to do this:

export PATH=$PATH:/home/randy/lib/python 

PYTHONPATH is used by the python interpreter to determine which modules to load.

PATH is used by the shell to determine which executables to run.

setting the id attribute of an input element dynamically in IE: alternative for setAttribute method

This code work in IE7 and Chrome:

var hiddenInput = document.createElement("input");
    hiddenInput.setAttribute("id", "uniqueIdentifier");
    hiddenInput.setAttribute("type", "hidden");                     
    hiddenInput.setAttribute("value", 'ID');
    hiddenInput.setAttribute("class", "ListItem");

$('body').append(hiddenInput);

Maybe problem somewhere else ?

What does it mean when a PostgreSQL process is "idle in transaction"?

The PostgreSQL manual indicates that this means the transaction is open (inside BEGIN) and idle. It's most likely a user connected using the monitor who is thinking or typing. I have plenty of those on my system, too.

If you're using Slony for replication, however, the Slony-I FAQ suggests idle in transaction may mean that the network connection was terminated abruptly. Check out the discussion in that FAQ for more details.

jQuery Scroll To bottom of the page

$('#pagedwn').bind("click", function () {
        $('html, body').animate({ scrollTop:3031 },"fast");
        return false;
});

This solution worked for me. It is working in Page Scroll Down fastly.

Using Pip to install packages to Anaconda Environment

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

  1. Run conda create -n venv_name and source activate venv_name, where venv_name is the name of your virtual environment.

  2. Run conda install pip. This will install pip to your venv directory.

  3. Find your anaconda directory, and find the actual venv folder. It should be somewhere like /anaconda/envs/venv_name/.

  4. Install new packages by doing /anaconda/envs/venv_name/bin/pip install package_name.

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

Pandas - Get first row value of a given column

To access a single value you can use the method iat that is much faster than iloc:

df['Btime'].iat[0]

Output:

1.2

Importing CSV data using PHP/MySQL

$i=0;
while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) {
if($i>0){
    $import="INSERT into importing(text,number)values('".$data[0]."','".$data[1]."')";
    mysql_query($import) or die(mysql_error());
}
$i=1;
}

toBe(true) vs toBeTruthy() vs toBeTrue()

Disclamer: This is just a wild guess

I know everybody loves an easy-to-read list:

  • toBe(<value>) - The returned value is the same as <value>
  • toBeTrue() - Checks if the returned value is true
  • toBeTruthy() - Check if the value, when cast to a boolean, will be a truthy value

    Truthy values are all values that aren't 0, '' (empty string), false, null, NaN, undefined or [] (empty array)*.

    * Notice that when you run !![], it returns true, but when you run [] == false it also returns true. It depends on how it is implemented. In other words: (!![]) === ([] == false)


On your example, toBe(true) and toBeTrue() will yield the same results.

How to check existence of user-define table type in SQL Server 2008?

You can look in sys.types or use TYPE_ID:

IF TYPE_ID(N'MyType') IS NULL ...

Just a precaution: using type_id won't verify that the type is a table type--just that a type by that name exists. Otherwise gbn's query is probably better.

How to check for changes on remote (origin) Git repository

One potential solution

Thanks to Alan Haggai Alavi's solution I came up with the following potential workflow:

Step 1:

git fetch origin

Step 2:

git checkout -b localTempOfOriginMaster origin/master
git difftool HEAD~3 HEAD~2
git difftool HEAD~2 HEAD~1
git difftool HEAD~1 HEAD~0

Step 3:

git checkout master
git branch -D localTempOfOriginMaster
git merge origin/master

HTML table headers always visible at top of window when viewing a large table

Using display: fixed on the thead section should work, but for it only work on the current table in view, you will need the help of JavaScript. And it will be tricky because it will need to figure out scrolling places and location of elements relative to the viewport, which is one of the prime areas of browser incompatibility.

Have a look at the popular JavaScript frameworks (jQuery, MooTools, YUI, etc etc.) to see if they can either do what you want or make it easier to do what you want.

How can I make robocopy silent in the command line except for progress?

robocopy also tends to print empty lines even if it does not do anything. I'm filtering empty lines away using command like this:

robocopy /NDL /NJH /NJS /NP /NS /NC %fromDir% %toDir% %filenames% | findstr /r /v "^$"

Open link in new tab or window

You should add the target="_blank" and rel="noopener noreferrer" in the anchor tag.

For example:

<a target="_blank" rel="noopener noreferrer" href="http://your_url_here.html">Link</a>

Adding rel="noopener noreferrer" is not mandatory, but it's a recommended security measure. More information can be found in the links below.

Source:

Easy way to pull latest of all git submodules

The following worked for me on Windows.

git submodule init
git submodule update

Why does fatal error "LNK1104: cannot open file 'C:\Program.obj'" occur when I compile a C++ project in Visual Studio?

I had this issue in conjunction with the LNK2038 error, followed this post to segregate the RELEASE and the DEBUG DLLs. In this process I had cleaned up the whole folder where these dependencies were residing.

Luckily I had a backup of all these files, and got the file for which this error was throwing back into the DEBUG folder to resolve the issue. The error code was misleading in some way as I had to spend a lot of time to come to this tip from one of the answers from this post again.

Hope this answer, helps someone in need.

Press enter in textbox to and execute button command

    private void textbox1_KeyDown(object sender, KeyEventArgs e)
    {
        if (e.KeyCode == Keys.Enter)
        {
            //cod for run
        }
    }

    private void buttonSearch_Click(object sender, EventArgs e)
    {
        textbox1_KeyDown(sender, new KeyEventArgs(Keys.Enter));
    }

How can you use php in a javascript function

I think you're confusing server code with client code.

JavaScript runs on the client after it has received data from the server (like a webpage).

PHP runs on the server before it sends the data.

So there are two ways with interacting with JavaScript with php.

Like above, you can generate javascript with php in the same fashion you generate HTML with php.

Or you can use an AJAX request from javascript to interact with the server. The server can respond with data and the javascript can receive that and do something with it.

I'd recommend going back to the basics and studying how HTTP works in the server-client relationship. Then study the concept of server side languages and client side languages.

Then take a tutorial with ajax, and you will start getting the concept.

Good luck, google is your friend.

Parsing XML with namespace in Python via 'ElementTree'

Here's how to do this with lxml without having to hard-code the namespaces or scan the text for them (as Martijn Pieters mentions):

from lxml import etree
tree = etree.parse("filename")
root = tree.getroot()
root.findall('owl:Class', root.nsmap)

UPDATE:

5 years later I'm still running into variations of this issue. lxml helps as I showed above, but not in every case. The commenters may have a valid point regarding this technique when it comes merging documents, but I think most people are having difficulty simply searching documents.

Here's another case and how I handled it:

<?xml version="1.0" ?><Tag1 xmlns="http://www.mynamespace.com/prefix">
<Tag2>content</Tag2></Tag1>

xmlns without a prefix means that unprefixed tags get this default namespace. This means when you search for Tag2, you need to include the namespace to find it. However, lxml creates an nsmap entry with None as the key, and I couldn't find a way to search for it. So, I created a new namespace dictionary like this

namespaces = {}
# response uses a default namespace, and tags don't mention it
# create a new ns map using an identifier of our choice
for k,v in root.nsmap.iteritems():
    if not k:
        namespaces['myprefix'] = v
e = root.find('myprefix:Tag2', namespaces)

How do I connect to my existing Git repository using Visual Studio Code?

Use the Git GUI in the Git plugin.

Clone your online repository with the URL which you have.

After cloning, make changes to the files. When you make changes, you can see the number changes. Commit those changes.

Fetch from the remote (to check if anything is updated while you are working).

If the fetch operation gives you an update about the changes in the remote repository, make a pull operation which will update your copy in Visual Studio Code. Otherwise, do not make a pull operation if there aren't any changes in the remote repository.

Push your changes to the upstream remote repository by making a push operation.

Set background image according to screen resolution

Hi heres a javascript version which changes the background image src according to screen resolution. You have to have the different images saved in the right size.

<html>
<head>    
<title>Javascript Change Div Background Image</title>        
<style type="text/css">    
body {
         margin:0;
         width:100%;
         height:100%;
}

#div1 {   
    background-image:url('sky.jpg');
    width:100%
    height:100%
}    

p {    
    font-family:Verdana;    
    font-weight:bold;    
    font-size:11px;    
}    
</style>    

<script language="javascript" type="text/javascript">
function changeDivImage()    
{   
//change the image path to a string   
var imgPath = new String();        
imgPath = document.getElementById("div1").style.backgroundImage;  

//get screen res of customer
var custHeight=screen.height;
var custWidth=screen.width;

//if their screen width is less than or equal to 640 then use the 640 pic url
if (custWidth <= 640)
    {
    document.getElementById("div1").style.backgroundImage = "url(640x480.jpg)";
    }

else if (custWidth <= 800)
    {
    document.getElementById("div1").style.backgroundImage = "url(800x600.jpg)";
    }

else if (custWidth <= 1024)
    {
    document.getElementById("div1").style.backgroundImage = "url(1024x768.jpg)";
    }

else if (custWidth <= 1280)
    {
    document.getElementById("div1").style.backgroundImage = "url(1280x960.jpg)";
    }

else if (custWidth <= 1600)
    {
    document.getElementById("div1").style.backgroundImage = "url(1600x1200.jpg)";
    }

else {
    document.getElementById("div1").style.backgroundImage = "url(graffiti.jpg)";
     }

    /*if(imgPath == "url(sky.jpg)" || imgPath == "")        
    {            
    document.getElementById("div1").style.backgroundImage = "url(graffiti.jpg)";        
     }
    else        
     {            
     document.getElementById("div1").style.backgroundImage = "url(sky.jpg)";        
     }*/
}    

</script>
</head>
<body onload="changeDivImage()">            

<div id="div1">   

 <p>This Javascript Example will change the background image of<br />HTML Div Tag onload using javascript screen resolution.</p>    
 <p>paragraph</p>
</div>    

<br/>    

</body>
</html>

command to remove row from a data frame

eldNew <- eld[-14,]

See ?"[" for a start ...

For ‘[’-indexing only: ‘i’, ‘j’, ‘...’ can be logical vectors, indicating elements/slices to select. Such vectors are recycled if necessary to match the corresponding extent. ‘i’, ‘j’, ‘...’ can also be negative integers, indicating elements/slices to leave out of the selection.

(emphasis added)

edit: looking around I notice How to delete the first row of a dataframe in R? , which has the answer ... seems like the title should have popped to your attention if you were looking for answers on SO?

edit 2: I also found How do I delete rows in a data frame? , searching SO for delete row data frame ...

Also http://rwiki.sciviews.org/doku.php?id=tips:data-frames:remove_rows_data_frame

Importing a CSV file into a sqlite3 database table using Python

You can do this using blaze & odo efficiently

import blaze as bz
csv_path = 'data.csv'
bz.odo(csv_path, 'sqlite:///data.db::data')

Odo will store the csv file to data.db (sqlite database) under the schema data

Or you use odo directly, without blaze. Either ways is fine. Read this documentation

Failed to resolve: com.android.support:appcompat-v7:27.+ (Dependency Error)

Find root build.gradle file and add google maven repo inside allprojects tag

repositories {
        mavenLocal()
        mavenCentral()
        maven {                                  // <-- Add this
            url 'https://maven.google.com/' 
            name 'Google'
        }
    } 

It's better to use specific version instead of variable version

compile 'com.android.support:appcompat-v7:27.0.0'

If you're using Android Plugin for Gradle 3.0.0 or latter version

repositories {
      mavenLocal()
      mavenCentral()
      google()        //---> Add this
} 

and inject dependency in this way :

implementation 'com.android.support:appcompat-v7:27.0.0'

Simulate limited bandwidth from within Chrome?

In Chrome Canary now you can limit the network throughput. This can be done in the "Network" options of the "Emulation" tab of the Console in the Dev Tools.

You might need to activate the Chrome flag "Enable Developer Tools experiments" (chrome://flags/#enable-devtools-experiments) (chrome://flags) to see this new feature. You can simulate some low bandwidth (GSM, GPRS, EDGE, 3G) for mobile connections.

Selectors in Objective-C?

In this case, the name of the selector is wrong. The colon here is part of the method signature; it means that the method takes one argument. I believe that you want

SEL sel = @selector(lowercaseString);

Is there a concise way to iterate over a stream with indices in Java 8?

String[] namesArray = {"Sam","Pamela", "Dave", "Pascal", "Erik"};
String completeString
         =  IntStream.range(0,namesArray.length)
           .mapToObj(i -> namesArray[i]) // Converting each array element into Object
           .map(String::valueOf) // Converting object to String again
           .collect(Collectors.joining(",")); // getting a Concat String of all values
        System.out.println(completeString);

OUTPUT : Sam,Pamela,Dave,Pascal,Erik

String[] namesArray = {"Sam","Pamela", "Dave", "Pascal", "Erik"};

IntStream.range(0,namesArray.length)
               .mapToObj(i -> namesArray[i]) // Converting each array element into Object
               .map(String::valueOf) // Converting object to String again
               .forEach(s -> {
                //You can do various operation on each element here
                System.out.println(s);
               }); // getting a Concat String of all 

To Collect in the List:

String[] namesArray = {"Sam","Pamela", "Dave", "Pascal", "Erik"};
 List<String> namesList
                =  IntStream.range(0,namesArray.length)
                .mapToObj(i -> namesArray[i]) // Converting each array element into Object
                .map(String::valueOf) // Converting object to String again
                .collect(Collectors.toList()); // collecting elements in List
        System.out.println(listWithIndex);

Difference between array_push() and $array[] =

No one said, but array_push only pushes a element to the END OF THE ARRAY, where $array[index] can insert a value at any given index. Big difference.

'printf' vs. 'cout' in C++

With primitives, it probably doesn't matter entirely which one you use. I say where it gets usefulness is when you want to output complex objects.

For example, if you have a class,

#include <iostream>
#include <cstdlib>

using namespace std;

class Something
{
public:
        Something(int x, int y, int z) : a(x), b(y), c(z) { }
        int a;
        int b;
        int c;

        friend ostream& operator<<(ostream&, const Something&);
};

ostream& operator<<(ostream& o, const Something& s)
{
        o << s.a << ", " << s.b << ", " << s.c;
        return o;
}

int main(void)
{
        Something s(3, 2, 1);

        // output with printf
        printf("%i, %i, %i\n", s.a, s.b, s.c);

        // output with cout
        cout << s << endl;

        return 0;
}

Now the above might not seem all that great, but let's suppose you have to output this in multiple places in your code. Not only that, let's say you add a field "int d." With cout, you only have to change it in once place. However, with printf, you'd have to change it in possibly a lot of places and not only that, you have to remind yourself which ones to output.

With that said, with cout, you can reduce a lot of times spent with maintenance of your code and not only that if you re-use the object "Something" in a new application, you don't really have to worry about output.

How do I print the key-value pairs of a dictionary in python

You can access your keys and/or values by calling items() on your dictionary.

for key, value in d.iteritems():
    print(key, value)

How can I truncate a double to only two decimal places in Java?

Maybe Math.floor(value * 100) / 100? Beware that the values like 3.54 may be not exactly represented with a double.

Escaping quotation marks in PHP

Either escape the quote:

$text1= "From time to \"time\"";

or use single quotes to denote your string:

$text1= 'From time to "time"';

How to use a switch case 'or' in PHP

If you must use || with switch then you can try :

$v = 1;
switch (true) {
    case ($v == 1 || $v == 2):
        echo 'the value is either 1 or 2';
        break;
}

If not your preferred solution would have been

switch($v) {
    case 1:
    case 2:
        echo "the value is either 1 or 2";
        break;
}

The issue is that both method is not efficient when dealing with large cases ... imagine 1 to 100 this would work perfectly

$r1 = range(1, 100);
$r2 = range(100, 200);
$v = 76;
switch (true) {
    case in_array($v, $r1) :
        echo 'the value is in range 1 to 100';
        break;
    case in_array($v, $r2) :
        echo 'the value is in range 100 to 200';
        break;
}

Getting "Lock wait timeout exceeded; try restarting transaction" even though I'm not using a transaction

mysql->SHOW PROCESSLIST;
kill xxxx; 

and then kill which one in sleep. In my case it is 2456.

enter image description here

Grant Select on a view not base table when base table is in a different database

As you state in one of your comments that the table in question is in a different database, then ownership chaining applies. I suspect there is a break in the chain somewhere - check that link for full details.

How to automatically add user account AND password with a Bash script?

You can use the -p option.

useradd -p encrypted_password newuser

Unfortunately, this does require you to hash the password yourself (where passwd does that for you). Unfortunately, there does not seem to be a standard utility to hash some data so you'll have to write that yourself.

Here's a little Python script I whipped up to do the encryption for you. Assuming you called it pcrypt, you would then write your above command line to:

useradd -p $(pcrypt ${passwd}) newuser

A couple of warnings to be aware of.

  1. While pcrypt is running, the plaintext will be visible to any user via the ps command.
  2. pcrypt uses the old style crypt function - if you are using something more moderns like an MD5 hash, you'll need to change pcrypt.

and here's pcrypt:

#!/usr/bin/env python

import crypt
import sys
import random

saltchars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"

def salt():
    return random.choice(saltchars) + random.choice(saltchars)

def hash(plain):
    return crypt.crypt(arg, salt())

if __name__ == "__main__":
    random.seed()
    for arg in sys.argv[1:]:
        sys.stdout.write("%s\n" % (hash(arg),))

Angular 2 Dropdown Options Default Value

Add on to @Matthijs 's answer, please make sure your select element has a name attribute and its name is unique in your html template. Angular 2 is using input name to update changes. Thus, if there are duplicated names or there is no name attached to input element, the binding will fail.

php: check if an array has duplicates

As you specifically said you didn't want to use array_unique I'm going to ignore the other answers despite the fact they're probably better.

Why don't you use array_count_values() and then check if the resulting array has any value greater than 1?

Disable click outside of bootstrap modal area to close modal

If you are using @ng-bootstrap use the following:

Component

import { Component, OnInit } from '@angular/core';
import { NgbModal } from '@ng-bootstrap/ng-bootstrap';

@Component({
  selector: 'example',
  templateUrl: './example.component.html',
  styleUrls: ['./example.component.scss'],
})
export class ExampleComponent implements OnInit {

  constructor(
    private ngbModal: NgbModal
  ) {}

  ngOnInit(): void {
  }

  openModal(exampleModal: any, $event: any) {
    this.ngbModal.open(exampleModal, {
      size: 'lg', // set modal size
      backdrop: 'static', // disable modal from closing on click outside
      keyboard: false, // disable modal closing by keyboard esc
    });
  }
}

Template

<div (click)="openModal(exampleModal, $event)"> </div>
    <ng-template #exampleModal let-modal>
        <div class="modal-header">
            <h5 class="modal-title">Test modal</h5>
        </div>
        <div class="modal-body p-3">
            <form action="">
                <div class="form-row">
                    <div class="form-group col-md-6">
                        <label for="">Test field 1</label>
                        <input type="text" class="form-control">
                    </div>
                    <div class="form-group col-md-6">
                        <label for="">Test field 2</label>
                        <input type="text" class="form-control">
                    </div>

                    <div class="text-right pt-4">
                        <button type="button" class="btn btn-light" (click)="modal.dismiss('Close')">Close</button>
                        <button class="btn btn-primary ml-1">Save</button>
                    </div>
            </form>
        </div>
    </ng-template>

This code was tested on angular 9 using:

  1. "@ng-bootstrap/ng-bootstrap": "^6.1.0",

  2. "bootstrap": "^4.4.1",

Difference between break and continue statement

for (int i = 1; i <= 3; i++) {
        if (i == 2) {

            continue;
        }
        System.out.print("[i:" + i + "]");

try this code in netbeans you'll understand the different between break and continue

for (int i = 1; i <= 3; i++) {
        if (i == 2) {

            break;
        }
        System.out.print("[i:" + i + "]");

Markdown to create pages and table of contents?

Based on albertodebortoli answer created the function with additional checks and substitution of punctuation marks.

# @fn       def generate_table_of_contents markdown # {{{
# @brief    Generates table of contents for given markdown text
#
# @param    [String]  markdown Markdown string e.g. File.read('README.md')
#
# @return   [String]  Table of content in markdown format.
#
def generate_table_of_contents markdown
  table_of_contents = ""
  i_section = 0
  # to track markdown code sections, because e.g. ruby comments also start with #
  inside_code_section = false
  markdown.each_line do |line|
    inside_code_section = !inside_code_section if line.start_with?('```')

    forbidden_words = ['Table of contents', 'define', 'pragma']
    next if !line.start_with?('#') || inside_code_section || forbidden_words.any? { |w| line =~ /#{w}/ }

    title = line.gsub("#", "").strip
    href = title.gsub(/(^[!.?:\(\)]+|[!.?:\(\)]+$)/, '').gsub(/[!.,?:; \(\)-]+/, "-").downcase

    bullet = line.count("#") > 1 ? " *" : "#{i_section += 1}."
    table_of_contents << "  " * (line.count("#") - 1) + "#{bullet} [#{title}](\##{href})\n"
  end
  table_of_contents
end

Calling a JavaScript function returned from an Ajax response

PHP side code Name of file class.sendCode.php

<?php
class  sendCode{ 

function __construct($dateini,$datefin) {

            echo $this->printCode($dateini,$datefin);
        }

    function printCode($dateini,$datefin){

        $code =" alert ('code Coming from AJAX {$this->dateini} and {$this->datefin}');";
//Insert all the code you want to execute, 
//only javascript or Jquery code , dont incluce <script> tags
            return $code ;
    }
}
new sendCode($_POST['dateini'],$_POST['datefin']);

Now from your Html page you must trigger the ajax function to send the data.

....  <script src="http://code.jquery.com/jquery-1.9.1.js"></script> ....
Date begin: <input type="text" id="startdate"><br>
Date end : <input type="text" id="enddate"><br>
<input type="button" value="validate'" onclick="triggerAjax()"/>

Now at our local script.js we will define the ajax

function triggerAjax() {
    $.ajax({
            type: "POST",
            url: 'class.sendCode.php',
            dataType: "HTML",
            data : {

                dateini : $('#startdate').val(),
                datefin : $('#enddate').val()},

                  success: function(data){
                      $.globalEval(data);
// here is where the magic is made by executing the data that comes from
// the php class.  That is our javascript code to be executed
                  }


        });
}

htaccess <Directory> deny from all

You cannot use the Directory directive in .htaccess. However if you create a .htaccess file in the /system directory and place the following in it, you will get the same result

#place this in /system/.htaccess as you had before
deny from all

How to catch a click event on a button?

All answers are based on anonymous inner class. We have one more way for adding click event for buttons as well as other components too.

An activity needs to implement View.OnClickListener interface and we need to override the onClick function. I think this is best approach compared to using anonymous class.

package com.pointerunits.helloworld;

import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity implements OnClickListener {
   private Button login;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      login = (Button)findViewById(R.id.loginbutton);
      login.setOnClickListener((OnClickListener) this);
      Log.i(DISPLAY_SERVICE, "Activity is created");

   }    

   @Override
   public boolean onCreateOptionsMenu(Menu menu) {

      getMenuInflater().inflate(R.menu.main, menu);
      return true;
    }

   @Override
   public void onClick(View v) {
     Log.i(DISPLAY_SERVICE, "Button clicked : " + v.getId());
   }
}

lambda expression join multiple tables with select and where clause

I was looking for something and I found this post. I post this code that managed many-to-many relationships in case someone needs it.

    var UserInRole = db.UsersInRoles.Include(u => u.UserProfile).Include(u => u.Roles)
    .Select (m => new 
    {
        UserName = u.UserProfile.UserName,
        RoleName = u.Roles.RoleName
    });

UIView's frame, bounds, center, origin, when to use what?

Marco's answer above is correct, but just to expand on the question of "under what context"...

frame - this is the property you most often use for normal iPhone applications. most controls will be laid out relative to the "containing" control so the frame.origin will directly correspond to where the control needs to display, and frame.size will determine how big to make the control.

center - this is the property you will likely focus on for sprite based games and animations where movement or scaling may occur. By default animation and rotation will be based on the center of the UIView. It rarely makes sense to try and manage such objects by the frame property.

bounds - this property is not a positioning property, but defines the drawable area of the UIView "relative" to the frame. By default this property is usually (0, 0, width, height). Changing this property will allow you to draw outside of the frame or restrict drawing to a smaller area within the frame. A good discussion of this can be found at the link below. It is uncommon for this property to be manipulated unless there is specific need to adjust the drawing region. The only exception is that most programs will use the [[UIScreen mainScreen] bounds] on startup to determine the visible area for the application and setup their initial UIView's frame accordingly.

Why is there an frame rectangle and an bounds rectangle in an UIView?

Hopefully this helps clarify the circumstances where each property might get used.

java.lang.ClassNotFoundException: sun.jdbc.odbc.JdbcOdbcDriver Exception occurring. Why?

For Java 7 you can simply omit the Class.forName() statement as it is not really required.

For Java 8 you cannot use the JDBC-ODBC Bridge because it has been removed. You will need to use something like UCanAccess instead. For more information, see

Manipulating an Access database from Java without ODBC

CakePHP find method with JOIN

Otro example, custom Data Pagination for JOIN

CODE in Controller CakePHP 2.6 is OK:

$this->SenasaPedidosFacturadosSds->recursive = -1;
    // Filtro
    $where = array(
        'joins' => array(
            array(
                'table' => 'usuarios',
                'alias' => 'Usuarios',
                'type' => 'INNER',
                'conditions' => array(
                    'Usuarios.usuario_id = SenasaPedidosFacturadosSds.usuarios_id'
                )
            ),
            array(
                'table' => 'senasa_pedidos',
                'alias' => 'SenasaPedidos',
                'type' => 'INNER',
                'conditions' => array(
                    'SenasaPedidos.id = SenasaPedidosFacturadosSds.senasa_pedidos_id'
                )
            ),
            array(
                'table' => 'clientes',
                'alias' => 'Clientes',
                'type' => 'INNER',
                'conditions' => array(
                    'Clientes.id_cliente = SenasaPedidos.clientes_id'
                )
            ),
        ),
        'fields'=>array(
            'SenasaPedidosFacturadosSds.*',
            'Usuarios.usuario_id',
            'Usuarios.apellido_nombre',
            'Usuarios.senasa_establecimientos_id',
            'Clientes.id_cliente',
            'Clientes.consolida_doc_sanitaria',
            'Clientes.requiere_senasa',
            'Clientes.razon_social',
            'SenasaPedidos.id',
            'SenasaPedidos.domicilio_entrega',
            'SenasaPedidos.sds',
            'SenasaPedidos.pt_ptr'
        ),
        'conditions'=>array(
            'Clientes.requiere_senasa'=>1
        ),
        'order' => 'SenasaPedidosFacturadosSds.created DESC',
        'limit'=>100
    );
    $this->paginate = $where;
    // Get datos
    $data = $this->Paginator->paginate();
    exit(debug($data));

OR Example 2, NOT active conditions:

$this->SenasaPedidosFacturadosSds->recursive = -1;
    // Filtro
    $where = array(
        'joins' => array(
            array(
                'table' => 'usuarios',
                'alias' => 'Usuarios',
                'type' => 'INNER',
                'conditions' => array(
                    'Usuarios.usuario_id = SenasaPedidosFacturadosSds.usuarios_id'
                )
            ),
            array(
                'table' => 'senasa_pedidos',
                'alias' => 'SenasaPedidos',
                'type' => 'INNER',
                'conditions' => array(
                    'SenasaPedidos.id = SenasaPedidosFacturadosSds.senasa_pedidos_id'
                )
            ),
            array(
                'table' => 'clientes',
                'alias' => 'Clientes',
                'type' => 'INNER',
                'conditions' => array(
                    'Clientes.id_cliente = SenasaPedidos.clientes_id',
                    'Clientes.requiere_senasa = 1'
                )
            ),
        ),
        'fields'=>array(
            'SenasaPedidosFacturadosSds.*',
            'Usuarios.usuario_id',
            'Usuarios.apellido_nombre',
            'Usuarios.senasa_establecimientos_id',
            'Clientes.id_cliente',
            'Clientes.consolida_doc_sanitaria',
            'Clientes.requiere_senasa',
            'Clientes.razon_social',
            'SenasaPedidos.id',
            'SenasaPedidos.domicilio_entrega',
            'SenasaPedidos.sds',
            'SenasaPedidos.pt_ptr'
        ),
        //'conditions'=>array(
        //    'Clientes.requiere_senasa'=>1
        //),
        'order' => 'SenasaPedidosFacturadosSds.created DESC',
        'limit'=>100
    );
    $this->paginate = $where;
    // Get datos
    $data = $this->Paginator->paginate();
    exit(debug($data));

Java simple code: java.net.SocketException: Unexpected end of file from server

Most likely the headers you are setting is incorrect or not acceptable.

Example: connnection.setRequestProperty("content-type", "application/json");

What happened to Lodash _.pluck?

Or try pure ES6 nonlodash method like this

const reducer = (array, object) => {
  array.push(object.a)
  return array
}

var objects = [{ 'a': 1 }, { 'a': 2 }];
objects.reduce(reducer, [])

preg_match in JavaScript?

Some Googling brought me to this :

_x000D_
_x000D_
function preg_match (regex, str) {
  return (new RegExp(regex).test(str))
}
console.log(preg_match("^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,6}$","test"))
console.log(preg_match("^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,6}$","[email protected]"))
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See https://locutus.io for more info.

Git: How to check if a local repo is up to date?

tried to format my answer, but couldn't.Please stackoverflow team, why posting answer is so hard.

neverthless,

answer:
git fetch origin
git status (you'll see result like "Your branch is behind 'origin/master' by 9 commits")
to update to remote changes : git pull

Creating a Jenkins environment variable using Groovy

Just had the same issue. Wanted to dynamically trigger parametrized downstream jobs based on the outcome of some groovy scripting.

Unfortunately on our Jenkins it's not possible to run System Groovy scripts. Therefore I had to do a small workaround:

  1. Run groovy script which creates a properties file where the environment variable to be set is specified

    def props = new File("properties.text")
    if (props.text == 'foo=bar') {
        props.text = 'foo=baz'
    } else {
        props.text = 'foo=bar'
    }
    
  2. Use env inject plugin to inject the variable written into this script

    Inject environment variable
    Property file path: properties.text
    

After that I was able to use the variable 'foo' as parameter for the parametrized trigger plugin. Some kind of workaround. But works!

How to actually search all files in Visual Studio

One can access the "Find in Files" window via the drop-down menu selection and search all files in the Entire Solution: Edit > Find and Replace > Find in Files

enter image description here

Other, alternative is to open the "Find in Files" window via the "Standard Toolbars" button as highlighted in the below screen-short:

enter image description here

Is there a JSON equivalent of XQuery/XPath?

@Naftule - with "defiant.js", it is possible to query a JSON structure with XPath expressions. Check out this evaluator to get an idea of how it works:

http://www.defiantjs.com/#xpath_evaluator

Unlike JSONPath, "defiant.js" delivers the full-scale support of the query syntax - of XPath on JSON structures.

The source code of defiant.js can be found here:
https://github.com/hbi99/defiant.js

Set port for php artisan.php serve

Laravel 5.8 to 8.0 and above

The SERVER_PORT environment variable will be picked up and used by Laravel. Either do:

export SERVER_PORT="8080"
php artisan serve

Or set SERVER_PORT=8080 in your .env file.

Earlier versions of Laravel:

For port 8080:

 php artisan serve --port=8080

And if you want to run it on port 80, you probably need to sudo:

sudo php artisan serve --port=80

Error : java.lang.NoSuchMethodError: org.objectweb.asm.ClassWriter.<init>(I)V

I had the same error when initializing Spring on startup, using some different library versions, but everything worked when I got my versions in this order in the classpath (the other libraries in the cp were not important):

  1. asm-3.1.jar
  2. cglib-nodep-2.1_3.jar
  3. asm-attrs-1.5.3.jar

How to use OpenSSL to encrypt/decrypt files?

As mentioned in the other answers, previous versions of openssl used a weak key derivation function to derive an AES encryption key from the password. However, openssl v1.1.1 supports a stronger key derivation function, where the key is derived from the password using pbkdf2 with a randomly generated salt, and multiple iterations of sha256 hashing (10,000 by default).

To encrypt a file:

 openssl aes-256-cbc -e -salt -pbkdf2 -iter 10000 -in plaintextfilename -out encryptedfilename

To decrypt a file:

  openssl aes-256-cbc -d -salt -pbkdf2 -iter 10000 -in encryptedfilename -out plaintextfilename

The remote host closed the connection. The error code is 0x800704CD

I too got this same error on my image handler that I wrote. I got it like 30 times a day on site with heavy traffic, managed to reproduce it also. You get this when a user cancels the request (closes the page or his internet connection is interrupted for example), in my case in the following row:

myContext.Response.OutputStream.Write(buffer, 0, bytesRead);

I can’t think of any way to prevent it but maybe you can properly handle this. Ex:

        try
        {
            …
            myContext.Response.OutputStream.Write(buffer, 0, bytesRead);
            …
        }catch (HttpException ex)
        {
            if (ex.Message.StartsWith("The remote host closed the connection."))
                ;//do nothing
            else
                //handle other errors
        }            
        catch (Exception e)
        {
            //handle other errors
        }
        finally
        {//close streams etc..
        }

Lists in ConfigParser

This is what I use for lists:

config file content:

[sect]
alist = a
        b
        c

code :

l = config.get('sect', 'alist').split('\n')

it work for strings

in case of numbers

config content:

nlist = 1
        2
        3

code:

nl = config.get('sect', 'alist').split('\n')
l = [int(nl) for x in nl]

thanks.

A html space is showing as %2520 instead of %20

The following code snippet resolved my issue. Thought this might be useful to others.

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var strEnc = this.$.txtSearch.value.replace(/\s/g, "-");_x000D_
strEnc = strEnc.replace(/-/g, " ");
_x000D_
_x000D_
_x000D_

Rather using default encodeURIComponent my first line of code is converting all spaces into hyphens using regex pattern /\s\g and the following line just does the reverse, i.e. converts all hyphens back to spaces using another regex pattern /-/g. Here /g is actually responsible for finding all matching characters.

When I am sending this value to my Ajax call, it traverses as normal spaces or simply %20 and thus gets rid of double-encoding.

Tomcat 7 is not running on browser(http://localhost:8080/ )

Double click on the Tomcat Server under the Servers tab in Eclipse Doing that opens a window in the editor with the top heading being Overview opens (there are 2 tabs-Overview and Modules). In that change the options under Server Locations, and g

Xcode couldn't find any provisioning profiles matching

You can get this issue if Apple update their terms. Simply log into your dev account and accept any updated terms and you should be good (you will need to goto Xcode -> project->signing and capabilities and retry the certificate check. This should get you going if terms are the issue.

Detecting real time window size changes in Angular 4

To get it on init

public innerWidth: any;
ngOnInit() {
    this.innerWidth = window.innerWidth;
}

If you wanna keep it updated on resize:

@HostListener('window:resize', ['$event'])
onResize(event) {
  this.innerWidth = window.innerWidth;
}

Firestore Getting documents id from collection

Can get ID before add documents in database:

var idBefore =  this.afs.createId();
console.log(idBefore);

What version of Python is on my Mac?

If you have both Python2 and Python3 installed on your Mac, you can use

python --version

to check the version of Python2, and

python3 --version

to check the version of Python3.

However, if only Python3 is installed, then your system might use python instead of python3 for Python3. In this case, you can just use

python --version

to check the version of Python3.

REST API - why use PUT DELETE POST GET?

The idea of REpresentational State Transfer is not about accessing data in the simplest way possible.

You suggested using post requests to access JSON, which is a perfectly valid way to access/manipulate data.

REST is a methodology for meaningful access of data. When you see a request in REST, it should immediately be apparant what is happening with the data.

For example:

GET: /cars/make/chevrolet

is likely going to return a list of chevy cars. A good REST api might even incorporate some output options in the querystring like ?output=json or ?output=html which would allow the accessor to decide what format the information should be encoded in.

After a bit of thinking about how to reasonably incorporate data typing into a REST API, I've concluded that the best way to specify the type of data explicitly would be via the already existing file extension such as .js, .json, .html, or .xml. A missing file extension would default to whatever format is default (such as JSON); a file extension that's not supported could return a 501 Not Implemented status code.

Another example:

POST: /cars/
{ make:chevrolet, model:malibu, colors:[red, green, blue, grey] }

is likely going to create a new chevy malibu in the db with the associated colors. I say likely as the REST api does not need to be directly related to the database structure. It is just a masking interface so that the true data is protected (think of it like accessors and mutators for a database structure).

Now we need to move onto the issue of idempotence. Usually REST implements CRUD over HTTP. HTTP uses GET, PUT, POST and DELETE for the requests.

A very simplistic implementation of REST could use the following CRUD mapping:

Create -> Post
Read   -> Get
Update -> Put
Delete -> Delete

There is an issue with this implementation: Post is defined as a non-idempotent method. This means that subsequent calls of the same Post method will result in different server states. Get, Put, and Delete, are idempotent; which means that calling them multiple times should result in an identical server state.

This means that a request such as:

Delete: /cars/oldest

could actually be implemented as:

Post: /cars/oldest?action=delete

Whereas

Delete: /cars/id/123456

will result in the same server state if you call it once, or if you call it 1000 times.

A better way of handling the removal of the oldest item would be to request:

Get: /cars/oldest

and use the ID from the resulting data to make a delete request:

Delete: /cars/id/[oldest id]

An issue with this method would be if another /cars item was added between when /oldest was requested and when the delete was issued.

Removing elements from array Ruby

[1,3].inject([1,1,1,2,2,3]) do |memo,element|
  memo.tap do |memo|
    i = memo.find_index(e)
    memo.delete_at(i) if i
  end
end

Change EditText hint color when using TextInputLayout

With the Material Components library you can customize the TextInputLayout the hint text color using:

  • In the layout:

    • app:hintTextColor attribute : the color of the label when it is collapsed and the text field is active
    • android:textColorHint attribute: the color of the label in all other text field states (such as resting and disabled)

Something like:

<com.google.android.material.textfield.TextInputLayout
     app:hintTextColor="@color/mycolor"
     android:textColorHint="@color/text_input_hint_selector"
     .../>

enter image description hereenter image description here

Html/PHP - Form - Input as array

Simply add [] to those names like

 <input type="text" class="form-control" placeholder="Titel" name="levels[level][]">
 <input type="text" class="form-control" placeholder="Titel" name="levels[build_time][]">

Take that template and then you can add those even using a loop.

Then you can add those dynamically as much as you want, without having to provide an index. PHP will pick them up just like your expected scenario example.

Edit

Sorry I had braces in the wrong place, which would make every new value as a new array element. Use the updated code now and this will give you the following array structure

levels > level (Array)
levels > build_time (Array)

Same index on both sub arrays will give you your pair. For example

echo $levels["level"][5];
echo $levels["build_time"][5];

Changing background color of selected cell?

I've had luck with the following:

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
    bool isSelected = // enter your own code here
    if (isSelected)
    {
        [cell setBackgroundColor:[UIColor colorWithRed:1 green:1 blue:0.75 alpha:1]];
        [cell setAccessibilityTraits:UIAccessibilityTraitSelected];
    }
    else
    {
        [cell setBackgroundColor:[UIColor clearColor]];
        [cell setAccessibilityTraits:0];
    }
}

Remote Connections Mysql Ubuntu

MySQL only listens to localhost, if we want to enable the remote access to it, then we need to made some changes in my.cnf file:

sudo nano /etc/mysql/my.cnf

We need to comment out the bind-address and skip-external-locking lines:

#bind-address = 127.0.0.1
# skip-external-locking

After making these changes, we need to restart the mysql service:

sudo service mysql restart

How to generate unique IDs for form labels in React?

This solutions works fine for me.

utils/newid.js:

let lastId = 0;

export default function(prefix='id') {
    lastId++;
    return `${prefix}${lastId}`;
}

And I can use it like this:

import newId from '../utils/newid';

React.createClass({
    componentWillMount() {
        this.id = newId();
    },
    render() {
        return (
            <label htmlFor={this.id}>My label</label>
            <input id={this.id} type="text"/>
        );
    }
});

But it won’t work in isomorphic apps.

Added 17.08.2015. Instead of custom newId function you can use uniqueId from lodash.

Updated 28.01.2016. It’s better to generate ID in componentWillMount.