Programs & Examples On #Jbox2d

JBox2D is a Java physics engine often used in games an other physics simulations and is a port/extension of the C++ physics engine, Box2D.

How to find which columns contain any NaN value in Pandas dataframe

I had a problem where I had to many columns to visually inspect on the screen so a short list comp that filters and returns the offending columns is

nan_cols = [i for i in df.columns if df[i].isnull().any()]

if that's helpful to anyone

How to create EditText accepts Alphabets only in android?

Put code edittext xml file,

   android:digits="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

How do I set browser width and height in Selenium WebDriver?

Try something like this:

IWebDriver _driver = new FirefoxDriver();
_driver.Manage().Window.Position = new Point(0, 0);
_driver.Manage().Window.Size = new Size(1024, 768);

Not sure if it'll resize after being launched though, so maybe it's not what you want

Division in Python 2.7. and 3.3

"/" is integer division in python 2 so it is going to round to a whole number. If you would like a decimal returned, just change the type of one of the inputs to float:

float(20)/15 #1.33333333

Check if table exists without using "select from"

If you want to be correct, use INFORMATION_SCHEMA.

SELECT * 
FROM information_schema.tables
WHERE table_schema = 'yourdb' 
    AND table_name = 'testtable'
LIMIT 1;

Alternatively, you can use SHOW TABLES

SHOW TABLES LIKE 'yourtable';

If there is a row in the resultset, table exists.

How to shrink/purge ibdata1 file in MySQL

When you delete innodb tables, MySQL does not free the space inside the ibdata file, that's why it keeps growing. These files hardly ever shrink.

How to shrink an existing ibdata file:

https://dev.mysql.com/doc/refman/5.6/en/innodb-system-tablespace.html#innodb-resize-system-tablespace

You can script this and schedule the script to run after a fixed period of time, but for the setup described above it seems that multiple tablespaces are an easier solution.

If you use the configuration option innodb_file_per_table, you create multiple tablespaces. That is, MySQL creates separate files for each table instead of one shared file. These separate files a stored in the directory of the database, and they are deleted when you delete this database. This should remove the need to shrink/purge ibdata files in your case.

More information about multiple tablespaces:

https://dev.mysql.com/doc/refman/5.6/en/innodb-file-per-table-tablespaces.html

How to use callback with useState hook in react

You can use useEffect/useLayoutEffect to achieve this:

const SomeComponent = () => {
  const [count, setCount] = React.useState(0)

  React.useEffect(() => {
    if (count > 1) {
      document.title = 'Threshold of over 1 reached.';
    } else {
      document.title = 'No threshold reached.';
    }
  }, [count]);

  return (
    <div>
      <p>{count}</p>

      <button type="button" onClick={() => setCount(count + 1)}>
        Increase
      </button>
    </div>
  );
};

More about it over here.

If you are looking for an out of the box solution, check out this custom hook that works like useState but accepts as second parameter a callback function:

// npm install use-state-with-callback

import useStateWithCallback from 'use-state-with-callback';

const SomeOtherComponent = () => {
  const [count, setCount] = useStateWithCallback(0, count => {
    if (count > 1) {
      document.title = 'Threshold of over 1 reached.';
    } else {
      document.title = 'No threshold reached.';
    }
  });

  return (
    <div>
      <p>{count}</p>

      <button type="button" onClick={() => setCount(count + 1)}>
        Increase
      </button>
    </div>
  );
};

Any way to clear python's IDLE window?

ctrl + L clears the screen on Ubuntu Linux.

Default instance name of SQL Server Express

You're right, it's localhost\SQLEXPRESS (just no $) and yes, it's the same for both 2005 and 2008 express versions.

How do I set the figure title and axes labels font size in Matplotlib?

An alternative solution to changing the font size is to change the padding. When Python saves your PNG, you can change the layout using the dialogue box that opens. The spacing between the axes, padding if you like can be altered at this stage.

Make a link open a new window (not tab)

You can try this:-

   <a href="some.htm" target="_blank">Link Text</a>

and you can try this one also:-

  <a href="some.htm" onclick="if(!event.ctrlKey&&!window.opera){alert('Hold the Ctrl Key');return false;}else{return true;}" target="_blank">Link Text</a>

How do I format date value as yyyy-mm-dd using SSIS expression builder?

Looks like you created a separate question. I was answering your other question How to change flat file source using foreach loop container in an SSIS package? with the same answer. Anyway, here it is again.

Create two string data type variables namely DirPath and FilePath. Set the value C:\backup\ to the variable DirPath. Do not set any value to the variable FilePath.

Variables

Select the variable FilePath and select F4 to view the properties. Set the EvaluateAsExpression property to True and set the Expression property as @[User::DirPath] + "Source" + (DT_STR, 4, 1252) DATEPART("yy" , GETDATE()) + "-" + RIGHT("0" + (DT_STR, 2, 1252) DATEPART("mm" , GETDATE()), 2) + "-" + RIGHT("0" + (DT_STR, 2, 1252) DATEPART("dd" , GETDATE()), 2)

Expression

ADB error: cannot connect to daemon

If nothing works Restart your PC . Restarting my computer does the trick

CentOS: Enabling GD Support in PHP Installation

For PHP7 on CentOS or EC2 Linux AMI:

sudo yum install php70-gd

Error in <my code> : object of type 'closure' is not subsettable

I think you meant to do url[i] <- paste(...

instead of url[i] = paste(.... If so replace = with <-.

How to force keyboard with numbers in mobile website in Android

This should work. But I have same problems on an Android phone.

<input type="number" /> <input type="tel" />

I found out, that if I didn't include the jquerymobile-framework, the keypad showed correctly on the two types of fields.

But I havn't found a solution to solve that problem, if you really need to use jquerymobile.

UPDATE: I found out, that if the form-tag is stored out of the

<div data-role="page"> 

The number keypad isn't shown. This must be a bug...

Convert nullable bool? to bool

The complete way would be:

bool b1;
bool? b2 = ???;
if (b2.HasValue)
   b1 = b2.Value;

Or you can test for specific values using

bool b3 = (b2 == true); // b2 is true, not false or null

How to list the tables in a SQLite database file that was opened with ATTACH?

There is a command available for this on the SQLite command line:

.tables ?PATTERN?      List names of tables matching a LIKE pattern

Which converts to the following SQL:

SELECT name FROM sqlite_master
WHERE type IN ('table','view') AND name NOT LIKE 'sqlite_%'
UNION ALL
SELECT name FROM sqlite_temp_master
WHERE type IN ('table','view')
ORDER BY 1

On select change, get data attribute value

this works for me

<select class="form-control" id="foo">
    <option value="first" data-id="1">first</option>
    <option value="second" data-id="2">second</option>
</select>

and the script

$('#foo').on("change",function(){
    var dataid = $("#foo option:selected").attr('data-id');
    alert(dataid)
});

How to use curl in a shell script?

Firstly, your example is looking quite correct and works well on my machine. You may go another way.

curl $CURLARGS $RVMHTTP > ./install.sh

All output now storing in ./install.sh file, which you can edit and execute.

Easy way to pull latest of all git submodules

The following worked for me on Windows.

git submodule init
git submodule update

Python for and if on one line

The reason it prints "three" is because you didnt define your array. The equivalent to what you're doing is:

arr = []
for i in array :
    if i == "two" :
        arr.push(i)
print(i)

You are asking for the last element it looked through, which is not what you should be doing. You need to be storing the array to a variable in order to get the element.

The english equivalent of what you are doing is:

You: "I need you to print all the elements in this array that equal two, but in an array. And each time you cycle through the list, define the current element as I."
Computer: "Here: ["two"]"
You: "Now tell me 'i'"
Computer: "'i' is equal to "three"
You: "Why?"

The reason 'i' is equal to "three" is because three was the last thing that was defined as I

the computer did:

i = "one"
i = "two"
i = "three"

print(["two"])

Because you asked it to.

If you want the index, go here If you want the values in an array, define the array, like this:

MyArray = [(i) for i in my_list if i=="two"]

How to find the socket connection state in C?

you can use SS_ISCONNECTED macro in getsockopt() function. SS_ISCONNECTED is define in socketvar.h.

Disable back button in react navigation

i think it is simple just add headerLeft : null , i am using react-native cli, so this is the example :

static navigationOptions = {
    headerLeft : null
};

How to stop a setTimeout loop?

setTimeout returns a timer handle, which you can use to stop the timeout with clearTimeout.

So for instance:

function setBgPosition() {
    var c = 0,
        timer = 0;
    var numbers = [0, -120, -240, -360, -480, -600, -720];
    function run() {
        Ext.get('common-spinner').setStyle('background-position', numbers[c++] + 'px 0px');
        if (c >= numbers.length) {
            c = 0;
        }
        timer = setTimeout(run, 200);
    }
    timer = setTimeout(run, 200);

    return stop;

    function stop() {
        if (timer) {
            clearTimeout(timer);
            timer = 0;
        }
}

So you'd use that as:

var stop = setBgPosition();
// ...later, when you're ready to stop...
stop();

Note that rather than having setBgPosition call itself again, I've just had it set c back to 0. Otherwise, this wouldn't work. Also note that I've used 0 as a handle value for when the timeout isn't pending; 0 isn't a valid return value from setTimeout so it makes a handy flag.

This is also one of the (few) places I think you'd be better off with setInterval rather than setTimeout. setInterval repeats. So:

function setBgPosition() {
    var c = 0;
    var numbers = [0, -120, -240, -360, -480, -600, -720];
    function run() {
        Ext.get('common-spinner').setStyle('background-position', numbers[c++] + 'px 0px');
        if (c >= numbers.length) {
            c = 0;
        }
    }
    return setInterval(run, 200);
}

Used like this:

var timer = setBgPosition();
// ...later, when you're ready to stop...
clearInterval(timer);

All of the above notwithstanding, I'd want to find a way to make setBgPosition stop things itself, by detecting that some completion condition has been satisfied.

Does C have a "foreach" loop construct?

Here is a full program example of a for-each macro in C99:

#include <stdio.h>

typedef struct list_node list_node;
struct list_node {
    list_node *next;
    void *data;
};

#define FOR_EACH(item, list) \
    for (list_node *(item) = (list); (item); (item) = (item)->next)

int
main(int argc, char *argv[])
{
    list_node list[] = {
        { .next = &list[1], .data = "test 1" },
        { .next = &list[2], .data = "test 2" },
        { .next = NULL,     .data = "test 3" }
    };

    FOR_EACH(item, list)
        puts((char *) item->data);

    return 0;
}

Split an integer into digits to compute an ISBN checksum

How about a one-liner list of digits...

ldigits = lambda n, l=[]: not n and l or l.insert(0,n%10) or ldigits(n/10,l)

EC2 instance has no public DNS

There is a actually a setting in the VPC called "DNS Hostnames". You can modify the VPC in which the EC2 instance exists, and change this to "Yes". That should do the trick.

I ran into this issue yesterday and tried the above answer from Manny, which did not work. The VPC setting, however, did work for me.

Ultimately I added an EIP and I use that to connect.

How can I combine two commits into one commit?

Lazy simple version for forgetfuls like me:

git rebase -i HEAD~3 or however many commits instead of 3.

Turn this

pick YourCommitMessageWhatever
pick YouGetThePoint
pick IdkManItsACommitMessage

into this

pick YourCommitMessageWhatever
s YouGetThePoint
s IdkManItsACommitMessage

and do some action where you hit esc then enter to save the changes. [1]

When the next screen comes up, get rid of those garbage # lines [2] and create a new commit message or something, and do the same escape enter action. [1]

Wowee, you have fewer commits. Or you just broke everything.


[1] - or whatever works with your git configuration. This is just a sequence that's efficient given my setup.

[2] - you'll see some stuff like # this is your n'th commit a few times, with your original commits right below these message. You want to remove these lines, and create a commit message to reflect the intentions of the n commits that you're combining into 1.

subsampling every nth entry in a numpy array

You can use numpy's slicing, simply start:stop:step.

>>> xs
array([1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4])
>>> xs[1::4]
array([2, 2, 2])

This creates a view of the the original data, so it's constant time. It'll also reflect changes to the original array and keep the whole original array in memory:

>>> a
array([1, 2, 3, 4, 5])
>>> b = a[::2]         # O(1), constant time
>>> b[:] = 0           # modifying the view changes original array
>>> a                  # original array is modified
array([0, 2, 0, 4, 0])

so if either of the above things are a problem, you can make a copy explicitly:

>>> a
array([1, 2, 3, 4, 5])
>>> b = a[::2].copy()  # explicit copy, O(n)
>>> b[:] = 0           # modifying the copy
>>> a                  # original is intact
array([1, 2, 3, 4, 5])

This isn't constant time, but the result isn't tied to the original array. The copy also contiguous in memory, which can make some operations on it faster.

Laravel - Form Input - Multiple select for a one to many relationship

@SamMonk your technique is great. But you can use laravel form helper to do so. I have a customer and dogs relationship.

On your controller

$dogs = Dog::lists('name', 'id');

On customer create view you can use.

{{ Form::label('dogs', 'Dogs') }}
{{ Form::select('dogs[]', $dogs, null, ['id' => 'dogs', 'multiple' => 'multiple']) }}

Third parameter accepts a list of array a well. If you define a relationship on your model you can do this:

{{ Form::label('dogs', 'Dogs') }}
{{ Form::select('dogs[]', $dogs, $customer->dogs->lists('id'), ['id' => 'dogs', 'multiple' => 'multiple']) }}

Update For Laravel 5.1

The lists method now returns a Collection. Upgrading To 5.1.0

{!! Form::label('dogs', 'Dogs') !!}
{!! Form::select('dogs[]', $dogs, $customer->dogs->lists('id')->all(), ['id' => 'dogs', 'multiple' => 'multiple']) !!}

There has been an error processing your request, Error log record number

Most of the time it is cause by broken database connection especially at local server, when one forget to start XAMPP or WAMPP server,

solution -1 :- Rename pub/local.xml.sample into local.xml or pub/local.xml into local.xml.sample if this is not work try solution 2

solution 2 :- go to php.ini file and increase max_execution time and fresh install magento confirm issue resolved

Apply style to cells of first row

Below works for first tr of the table under thead

table thead tr:first-child {
   background: #f2f2f2;
}

And this works for the first tr of thead and tbody both:

table thead tbody tr:first-child {
   background: #f2f2f2;
}

Abort a Git Merge

as long as you did not commit you can type

git merge --abort

just as the command line suggested.

Using Alert in Response.Write Function in ASP.NET

Use this....

string popupScript = "<script language=JavaScript>";
popupScript += "alert('Please enter valid Email Id');";
popupScript += "</";
popupScript += "script>";
Page.RegisterStartupScript("PopupScript", popupScript);

JavaFX How to set scene background image

I know this is an old Question

But in case you want to do it programmatically or the java way

For Image Backgrounds; you can use BackgroundImage class

BackgroundImage myBI= new BackgroundImage(new Image("my url",32,32,false,true),
        BackgroundRepeat.REPEAT, BackgroundRepeat.NO_REPEAT, BackgroundPosition.DEFAULT,
          BackgroundSize.DEFAULT);
//then you set to your node
myContainer.setBackground(new Background(myBI));

For Paint or Fill Backgrounds; you can use BackgroundFill class

BackgroundFill myBF = new BackgroundFill(Color.BLUEVIOLET, new CornerRadii(1),
         new Insets(0.0,0.0,0.0,0.0));// or null for the padding
//then you set to your node or container or layout
myContainer.setBackground(new Background(myBF));

Keeps your java alive && your css dead..

Pylint, PyChecker or PyFlakes?

Well, I am a bit curious, so I just tested the three myself right after asking the question ;-)

Ok, this is not a very serious review, but here is what I can say:

I tried the tools with the default settings (it's important because you can pretty much choose your check rules) on the following script:

#!/usr/local/bin/python
# by Daniel Rosengren modified by e-satis

import sys, time
stdout = sys.stdout

BAILOUT = 16
MAX_ITERATIONS = 1000

class Iterator(object) :

    def __init__(self):

        print 'Rendering...'
        for y in xrange(-39, 39):
            stdout.write('\n')
            for x in xrange(-39, 39):
                if self.mandelbrot(x/40.0, y/40.0) :
                    stdout.write(' ')
                else:
                    stdout.write('*')


    def mandelbrot(self, x, y):
        cr = y - 0.5
        ci = x
        zi = 0.0
        zr = 0.0

        for i in xrange(MAX_ITERATIONS) :
            temp = zr * zi
            zr2 = zr * zr
            zi2 = zi * zi
            zr = zr2 - zi2 + cr
            zi = temp + temp + ci

            if zi2 + zr2 > BAILOUT:
                return i

        return 0

t = time.time()
Iterator()
print '\nPython Elapsed %.02f' % (time.time() - t)

As a result:

  • PyChecker is troublesome because it compiles the module to analyze it. If you don't want your code to run (e.g, it performs a SQL query), that's bad.
  • PyFlakes is supposed to be light. Indeed, it decided that the code was perfect. I am looking for something quite severe so I don't think I'll go for it.
  • PyLint has been very talkative and rated the code 3/10 (OMG, I'm a dirty coder !).

Strong points of PyLint:

  • Very descriptive and accurate report.
  • Detect some code smells. Here it told me to drop my class to write something with functions because the OO approach was useless in this specific case. Something I knew, but never expected a computer to tell me :-p
  • The fully corrected code run faster (no class, no reference binding...).
  • Made by a French team. OK, it's not a plus for everybody, but I like it ;-)

Cons of Pylint:

  • Some rules are really strict. I know that you can change it and that the default is to match PEP8, but is it such a crime to write 'for x in seq'? Apparently yes because you can't write a variable name with less than 3 letters. I will change that.
  • Very very talkative. Be ready to use your eyes.

Corrected script (with lazy doc strings and variable names):

#!/usr/local/bin/python
# by Daniel Rosengren, modified by e-satis
"""
Module doctring
"""


import time
from sys import stdout

BAILOUT = 16
MAX_ITERATIONS = 1000

def mandelbrot(dim_1, dim_2):
    """
    function doc string
    """
    cr1 = dim_1 - 0.5
    ci1 = dim_2
    zi1 = 0.0
    zr1 = 0.0

    for i in xrange(MAX_ITERATIONS) :
        temp = zr1 * zi1
        zr2 = zr1 * zr1
        zi2 = zi1 * zi1
        zr1 = zr2 - zi2 + cr1
        zi1 = temp + temp + ci1

        if zi2 + zr2 > BAILOUT:
            return i

    return 0

def execute() :
    """
    func doc string
    """
    print 'Rendering...'
    for dim_1 in xrange(-39, 39):
        stdout.write('\n')
        for dim_2 in xrange(-39, 39):
            if mandelbrot(dim_1/40.0, dim_2/40.0) :
                stdout.write(' ')
            else:
                stdout.write('*')


START_TIME = time.time()
execute()
print '\nPython Elapsed %.02f' % (time.time() - START_TIME)

Thanks to Rudiger Wolf, I discovered pep8 that does exactly what its name suggests: matching PEP8. It has found several syntax no-nos that Pylint did not. But Pylint found stuff that was not specifically linked to PEP8 but interesting. Both tools are interesting and complementary.

Eventually I will use both since there are really easy to install (via packages or setuptools) and the output text is so easy to chain.

To give you a little idea of their output:

pep8:

./python_mandelbrot.py:4:11: E401 multiple imports on one line
./python_mandelbrot.py:10:1: E302 expected 2 blank lines, found 1
./python_mandelbrot.py:10:23: E203 whitespace before ':'
./python_mandelbrot.py:15:80: E501 line too long (108 characters)
./python_mandelbrot.py:23:1: W291 trailing whitespace
./python_mandelbrot.py:41:5: E301 expected 1 blank line, found 3

Pylint:

************* Module python_mandelbrot
C: 15: Line too long (108/80)
C: 61: Line too long (85/80)
C:  1: Missing docstring
C:  5: Invalid name "stdout" (should match (([A-Z_][A-Z0-9_]*)|(__.*__))$)
C: 10:Iterator: Missing docstring
C: 15:Iterator.__init__: Invalid name "y" (should match [a-z_][a-z0-9_]{2,30}$)
C: 17:Iterator.__init__: Invalid name "x" (should match [a-z_][a-z0-9_]{2,30}$)

[...] and a very long report with useful stats like :

Duplication
-----------

+-------------------------+------+---------+-----------+
|                         |now   |previous |difference |
+=========================+======+=========+===========+
|nb duplicated lines      |0     |0        |=          |
+-------------------------+------+---------+-----------+
|percent duplicated lines |0.000 |0.000    |=          |
+-------------------------+------+---------+-----------+

How to set a session variable when clicking a <a> link

I had the same problem - i wanted to pass a parameter to another page by clicking a hyperlink and get the value to go to the next page (without using GET because the parameter is stored in the URL).

to those who don't understand why you would want to do this the answer is you dont want the user to see sensitive information or you dont want someone editing the GET.

well after scouring the internet it seemed it wasnt possible to make a normal hyperlink using the POST method.

And then i had a eureka moment!!!! why not just use CSS to make the submit button look like a normal hyperlink??? ...and put the value i want to pass in a hidden field

i tried it and it works. you can see an exaple here http://paulyouthed.com/test/css-button-that-looks-like-hyperlink.php

the basic code for the form is:

    <form enctype="multipart/form-data" action="page-to-pass-to.php" method="post">
                        <input type="hidden" name="post-variable-name" value="value-you-want-pass"/>
                        <input type="submit" name="whatever" value="text-to-display" id="hyperlink-style-button"/>
                </form>

the basic css is:

    #hyperlink-style-button{
      background:none;
      border:0;
      color:#666;
      text-decoration:underline;
    }

    #hyperlink-style-button:hover{
      background:none;
      border:0;
      color:#666;
      text-decoration:none;
      cursor:pointer;
      cursor:hand;
    }

How can I perform an inspect element in Chrome on my Galaxy S3 Android device?

Update: 8-20-2015

Please note the instructions have changed since this question was asked 2 yrs ago.

So on Newer versions of Android and Chrome for Android. You need to use this.

https://developers.google.com/web/tools/setup/remote-debugging/remote-debugging?hl=en

Original Answer:

I have the S3 and it works fine. I have found that a common mistake is not enabling USB Debugging in Chrome mobile. Not only do you have to enable USB debugging on the device itself under developer options but you have to go to the Chrome Browser on your phone and enable it in the settings there too.

Try this with the SDK

  1. Chrome for Mobile - Settings > Developer Tools > [x] Enable USB Web debugging
  2. Device - Settings > Developer options > [x] USB debugging
  3. Connect Device to Computer
  4. Enable port forwarding on your computer by doing the following command below

    C:\adb forward tcp:9222 localabstract:chrome_devtools_remote

Go to http://localhost:9222 in Chrome on your Computer

TroubleShooting:

If you get command not found when trying to run ADB, make sure Platform-Tools is in your path or just use the whole path to your SDK and run it

C:\path-to-SDK\platform-tools\adb forward tcp:9222 localabstract:chrome_devtools_remote

If you get "device not found", then run adb kill-server and then try again.

Which concurrent Queue implementation should I use in Java?

  1. SynchronousQueue ( Taken from another question )

SynchronousQueue is more of a handoff, whereas the LinkedBlockingQueue just allows a single element. The difference being that the put() call to a SynchronousQueue will not return until there is a corresponding take() call, but with a LinkedBlockingQueue of size 1, the put() call (to an empty queue) will return immediately. It's essentially the BlockingQueue implementation for when you don't really want a queue (you don't want to maintain any pending data).

  1. LinkedBlockingQueue (LinkedList Implementation but Not Exactly JDK Implementation of LinkedList It uses static inner class Node to maintain Links between elements )

Constructor for LinkedBlockingQueue

public LinkedBlockingQueue(int capacity) 
{
        if (capacity < = 0) throw new IllegalArgumentException();
        this.capacity = capacity;
        last = head = new Node< E >(null);   // Maintains a underlying linkedlist. ( Use when size is not known )
}

Node class Used to Maintain Links

static class Node<E> {
    E item;
    Node<E> next;
    Node(E x) { item = x; }
}

3 . ArrayBlockingQueue ( Array Implementation )

Constructor for ArrayBlockingQueue

public ArrayBlockingQueue(int capacity, boolean fair) 
{
            if (capacity < = 0)
                throw new IllegalArgumentException();
            this.items = new Object[capacity]; // Maintains a underlying array
            lock = new ReentrantLock(fair);
            notEmpty = lock.newCondition();
            notFull =  lock.newCondition();
}

IMHO Biggest Difference between ArrayBlockingQueue and LinkedBlockingQueue is clear from constructor one has underlying data structure Array and other linkedList.

ArrayBlockingQueue uses single-lock double condition algorithm and LinkedBlockingQueue is variant of the "two lock queue" algorithm and it has 2 locks 2 conditions ( takeLock , putLock)

Checking the form field values before submitting that page

use return before calling the function, while you click the submit button, two events(form posting as you used submit button and function call for onclick) will happen, to prevent form posting you have to return false, you have did it, also you have to specify the return i.e, to expect a value from the function,

this is a code:

input type="submit" name="continue" value="submit" onClick="**return** checkform();"

Get Wordpress Category from Single Post

<div class="post_category">
        <?php $category = get_the_category();
             $allcategory = get_the_category(); 
        foreach ($allcategory as $category) {
        ?>
           <a class="btn"><?php echo $category->cat_name;; ?></a>
        <?php 
        }
        ?>
 </div>

How do I remove a submodule?

What I'm currently doing Dec 2012 (combines most of these answers):

oldPath="vendor/example"
git config -f .git/config --remove-section "submodule.${oldPath}"
git config -f .gitmodules --remove-section "submodule.${oldPath}"
git rm --cached "${oldPath}"
rm -rf "${oldPath}"              ## remove src (optional)
rm -rf ".git/modules/${oldPath}" ## cleanup gitdir (optional housekeeping)
git add .gitmodules
git commit -m "Removed ${oldPath}"

PowerShell equivalent to grep -f

but select-String doesn't seem to have this option.

Correct. PowerShell is not a clone of *nix shells' toolset.

However it is not hard to build something like it yourself:

$regexes = Get-Content RegexFile.txt | 
           Foreach-Object { new-object System.Text.RegularExpressions.Regex $_ }

$fileList | Get-Content | Where-Object {
  foreach ($r in $regexes) {
    if ($r.IsMatch($_)) {
      $true
      break
    }
  }
  $false
}

Artificially create a connection timeout error

You can use the Python REPL to simulate a timeout while receiving data (i.e. after a connection has been established successfully). Nothing but a standard Python installation is needed.

Python 2.7.4 (default, Apr  6 2013, 19:54:46) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import socket
>>> s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)        
>>> s.bind(('localhost', 9000))
>>> s.listen(0)
>>> (clientsocket, address) = s.accept()

Now it waits for an incoming connection. Connect whatever you want to test to localhost:9000. When you do, Python will accept the connection and accept() will return it. Unless you send any data through the clientsocket, the caller's socket should time out during the next recv().

What is this weird colon-member (" : ") syntax in the constructor?

The other already explained to you that the syntax that you observe is called "constructor initializer list". This syntax lets you to custom-initialize base subobjects and member subobjects of the class (as opposed to allowing them to default-initialize or to remain uninitialized).

I just want to note that the syntax that, as you said, "looks like a constructor call", is not necessarily a constructor call. In C++ language the () syntax is just one standard form of initialization syntax. It is interpreted differently for different types. For class types with user-defined constructor it means one thing (it is indeed a constructor call), for class types without user-defined constructor it means another thing (so called value initialization ) for empty ()) and for non-class types it again means something different (since non-class types have no constructors).

In your case the data member has type int. int is not a class type, so it has no constructor. For type int this syntax means simply "initialize bar with the value of num" and that's it. It is done just like that, directly, no constructors involved, since, once again, int is not a class type of therefore it can't have any constructors.

How to add a Try/Catch to SQL Stored Procedure

Create Proc[usp_mquestions]  
( 
 @title  nvarchar(500),   --0
 @tags  nvarchar(max),   --1
 @category  nvarchar(200),   --2
 @ispoll  char(1),   --3
 @descriptions  nvarchar(max),   --4
)              
 AS  
 BEGIN TRY




BEGIN
DECLARE @message varchar(1000); 
DECLARE @tempid bigint; 

IF((SELECT count(id) from  [xyz] WHERE title=@title)>0)
BEGIN
SELECT 'record already existed.';
END
ELSE
BEGIN               


if @id=0 
begin 
select @tempid =id from [xyz] where id=@id;

if @tempid is null 
BEGIN 
        INSERT INTO xyz
        (entrydate,updatedate)
        VALUES
        (GETDATE(),GETDATE())

        SET @tempid=@@IDENTITY;
 END 
END 
ELSE 
BEGIN 
set @tempid=@id 
END 
if @tempid>0 
BEGIN 

    -- Updation of table begin--


UPDATE  tab_questions
set title=@title, --0 
 tags=@tags, --1 
 category=@category, --2 
 ispoll=@ispoll, --3 
 descriptions=@descriptions, --4 
 status=@status, --5

WHERE id=@tempid ; --9 ;


IF @id=0 
BEGIN 
SET @message= 'success:Record added successfully:'+ convert(varchar(10), @tempid)
END 
ELSE 
BEGIN 
SET @message= 'success:Record updated successfully.:'+ convert(varchar(10), @tempid)

END 
END 
ELSE 
BEGIN 
SET @message= 'failed:invalid request:'+convert(varchar(10), @tempid)
END 

END
END

END TRY
BEGIN CATCH
    SET @message='failed:'+ ERROR_MESSAGE();
END CATCH
SELECT @message;

jQuery Dialog Box

Looks like there is an issue with the code you posted. Your function to display the T&C is referencing the wrong div id. You should consider assigning the showTOC function to the onclick attribute once the document is loaded as well:

$(document).ready({
    $('a.TOClink').click(function(){
        showTOC();
    });
});

function showTOC() {
    $('#example').dialog({modal:true});
}

A more concise example which accomplishes the desired effect using the jQuery UI dialog is:

   <div id="terms" style="display:none;">
       Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
   </div>
   <a id="showTerms" href="#">Show Terms &amp; Conditions</a>      
   <script type="text/javascript">
       $(document).ready(function(){
           $('#showTerms').click(function(){
               $('#terms').dialog({modal:true});   
           });
       });
   </script>

Which is preferred: Nullable<T>.HasValue or Nullable<T> != null?

The compiler replaces null comparisons with a call to HasValue, so there is no real difference. Just do whichever is more readable/makes more sense to you and your colleagues.

Pandas df.to_csv("file.csv" encode="utf-8") still gives trash characters for minus sign

Your "bad" output is UTF-8 displayed as CP1252.

On Windows, many editors assume the default ANSI encoding (CP1252 on US Windows) instead of UTF-8 if there is no byte order mark (BOM) character at the start of the file. While a BOM is meaningless to the UTF-8 encoding, its UTF-8-encoded presence serves as a signature for some programs. For example, Microsoft Office's Excel requires it even on non-Windows OSes. Try:

df.to_csv('file.csv',encoding='utf-8-sig')

That encoder will add the BOM.

How to get the currently logged in user's user id in Django?

FOR WITHIN TEMPLATES

This is how I usually get current logged in user and their id in my templates.

<p>Your Username is : {{user}} </p>
<p>Your User Id is  : {{user.id}} </p>

Where does SVN client store user authentication data?

It sounds like you are doing everything exactly as the client credential section of the Subversion book suggests. The only thing I can think of is that the server isn't asking for the username and password because is getting it from somewhere else.

Selecting data from two different servers in SQL Server

SELECT
        *
FROM
        [SERVER2NAME].[THEDB].[THEOWNER].[THETABLE]

You can also look at using Linked Servers. Linked servers can be other types of data sources too such as DB2 platforms. This is one method for trying to access DB2 from a SQL Server TSQL or Sproc call...

Trigger back-button functionality on button click in Android

public boolean onKeyDown(int keyCode, KeyEvent event) {
             if (keyCode == KeyEvent.KEYCODE_BACK) {
                     // your code here
                     return false;
             }
         return super.onKeyDown(keyCode, event);
     }

What's the difference between unit, functional, acceptance, and integration tests?

This is very simple.

  1. Unit testing: This is the testing actually done by developers that have coding knowledge. This testing is done at the coding phase and it is a part of white box testing. When a software comes for development, it is developed into the piece of code or slices of code known as a unit. And individual testing of these units called unit testing done by developers to find out some kind of human mistakes like missing of statement coverage etc..

  2. Functional testing: This testing is done at testing (QA) phase and it is a part of black box testing. The actual execution of the previously written test cases. This testing is actually done by testers, they find the actual result of any functionality in the site and compare this result to the expected result. If they found any disparity then this is a bug.

  3. Acceptance testing: know as UAT. And this actually done by the tester as well as developers, management team, author, writers, and all who are involved in this project. To ensure the project is finally ready to be delivered with bugs free.

  4. Integration testing: The units of code (explained in point 1) are integrated with each other to complete the project. These units of codes may be written in different coding technology or may these are of different version so this testing is done by developers to ensure that all units of the code are compatible with other and there is no any issue of integration.

Can I have multiple background images using CSS?

CSS3 allows this sort of thing and it looks like this:

body {
    background-image: url(images/bgtop.png), url(images/bg.png);
    background-repeat: repeat-x, repeat;
}

The current versions of all the major browsers now support it, however if you need to support IE8 or below, then the best way you can work around it is to have extra divs:

<body>
    <div id="bgTopDiv">
        content here
    </div>
</body>
body{
    background-image: url(images/bg.png);
}
#bgTopDiv{
    background-image: url(images/bgTop.png);
    background-repeat: repeat-x;
}

Python: finding an element in a list

I found this by adapting some tutos. Thanks to google, and to all of you ;)

def findall(L, test):
    i=0
    indices = []
    while(True):
        try:
            # next value in list passing the test
            nextvalue = filter(test, L[i:])[0]

            # add index of this value in the index list,
            # by searching the value in L[i:] 
            indices.append(L.index(nextvalue, i))

            # iterate i, that is the next index from where to search
            i=indices[-1]+1
        #when there is no further "good value", filter returns [],
        # hence there is an out of range exeption
        except IndexError:
            return indices

A very simple use:

a = [0,0,2,1]
ind = findall(a, lambda x:x>0))

[2, 3]

P.S. scuse my english

Editing the date formatting of x-axis tick labels in matplotlib

From the package matplotlib.dates as shown in this example the date format can be applied to the axis label and ticks for plot.

Below I have given an example for labeling axis ticks for multiplots

import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import pandas as pd

df = pd.read_csv('US_temp.csv')
plt.plot(df['Date'],df_f['MINT'],label='Min Temp.')
plt.plot(df['Date'],df_f['MAXT'],label='Max Temp.')
plt.legend()
####### Use the below functions #######
dtFmt = mdates.DateFormatter('%b') # define the formatting
plt.gca().xaxis.set_major_formatter(dtFmt) # apply the format to the desired axis
plt.show()

As simple as that

UILabel - auto-size label to fit text?

I had a huge problems with auto layout. We have two containers inside table cell. Second container is resized depending on Item description (0 - 1000 chars), and row should be resized based on them.

The missing ingredient was bottom constraint for description.

I've changed bottom constraint of dynamic element from = 0 to >= 0.

Read Session Id using Javascript

Here's a short and sweet JavaScript function to fetch the session ID:

function session_id() {
    return /SESS\w*ID=([^;]+)/i.test(document.cookie) ? RegExp.$1 : false;
}

Or if you prefer a variable, here's a simple one-liner:

var session_id = /SESS\w*ID=([^;]+)/i.test(document.cookie) ? RegExp.$1 : false;

Should match the session ID cookie for PHP, JSP, .NET, and I suppose various other server-side processors as well.

Explaining the 'find -mtime' command

To find all files modified in the last 24 hours use the one below. The -1 here means changed 1 day or less ago.

find . -mtime -1 -ls

Simple way to unzip a .zip file using zlib

Minizip does have an example programs to demonstrate its usage - the files are called minizip.c and miniunz.c.

Update: I had a few minutes so I whipped up this quick, bare bones example for you. It's very smelly C, and I wouldn't use it without major improvements. Hopefully it's enough to get you going for now.

// uzip.c - Simple example of using the minizip API.
// Do not use this code as is! It is educational only, and probably
// riddled with errors and leaks!
#include <stdio.h>
#include <string.h>

#include "unzip.h"

#define dir_delimter '/'
#define MAX_FILENAME 512
#define READ_SIZE 8192

int main( int argc, char **argv )
{
    if ( argc < 2 )
    {
        printf( "usage:\n%s {file to unzip}\n", argv[ 0 ] );
        return -1;
    }

    // Open the zip file
    unzFile *zipfile = unzOpen( argv[ 1 ] );
    if ( zipfile == NULL )
    {
        printf( "%s: not found\n" );
        return -1;
    }

    // Get info about the zip file
    unz_global_info global_info;
    if ( unzGetGlobalInfo( zipfile, &global_info ) != UNZ_OK )
    {
        printf( "could not read file global info\n" );
        unzClose( zipfile );
        return -1;
    }

    // Buffer to hold data read from the zip file.
    char read_buffer[ READ_SIZE ];

    // Loop to extract all files
    uLong i;
    for ( i = 0; i < global_info.number_entry; ++i )
    {
        // Get info about current file.
        unz_file_info file_info;
        char filename[ MAX_FILENAME ];
        if ( unzGetCurrentFileInfo(
            zipfile,
            &file_info,
            filename,
            MAX_FILENAME,
            NULL, 0, NULL, 0 ) != UNZ_OK )
        {
            printf( "could not read file info\n" );
            unzClose( zipfile );
            return -1;
        }

        // Check if this entry is a directory or file.
        const size_t filename_length = strlen( filename );
        if ( filename[ filename_length-1 ] == dir_delimter )
        {
            // Entry is a directory, so create it.
            printf( "dir:%s\n", filename );
            mkdir( filename );
        }
        else
        {
            // Entry is a file, so extract it.
            printf( "file:%s\n", filename );
            if ( unzOpenCurrentFile( zipfile ) != UNZ_OK )
            {
                printf( "could not open file\n" );
                unzClose( zipfile );
                return -1;
            }

            // Open a file to write out the data.
            FILE *out = fopen( filename, "wb" );
            if ( out == NULL )
            {
                printf( "could not open destination file\n" );
                unzCloseCurrentFile( zipfile );
                unzClose( zipfile );
                return -1;
            }

            int error = UNZ_OK;
            do    
            {
                error = unzReadCurrentFile( zipfile, read_buffer, READ_SIZE );
                if ( error < 0 )
                {
                    printf( "error %d\n", error );
                    unzCloseCurrentFile( zipfile );
                    unzClose( zipfile );
                    return -1;
                }

                // Write data to file.
                if ( error > 0 )
                {
                    fwrite( read_buffer, error, 1, out ); // You should check return of fwrite...
                }
            } while ( error > 0 );

            fclose( out );
        }

        unzCloseCurrentFile( zipfile );

        // Go the the next entry listed in the zip file.
        if ( ( i+1 ) < global_info.number_entry )
        {
            if ( unzGoToNextFile( zipfile ) != UNZ_OK )
            {
                printf( "cound not read next file\n" );
                unzClose( zipfile );
                return -1;
            }
        }
    }

    unzClose( zipfile );

    return 0;
}

I built and tested it with MinGW/MSYS on Windows like this:

contrib/minizip/$ gcc -I../.. -o unzip uzip.c unzip.c ioapi.c ../../libz.a
contrib/minizip/$ ./unzip.exe /j/zlib-125.zip

How to script FTP upload and download?

Create a command file with your commands

ie: commands.txt

open www.domainhere.com
user useridhere 
passwordhere
put test.txt
bye

Then run the FTP client from the command line: ftp -s:commands.txt

Note: This will work for the Windows FTP client.

Edit: Should have had a linebreak after the user name before the password.

How can you remove all documents from a collection with Mongoose?

.remove() is deprecated. instead we can use deleteMany

DateTime.deleteMany({}, callback).

android.view.InflateException: Binary XML file line #12: Error inflating class <unknown>

i had the same issue and it solved by removing drawable-v24 with (24) in front of images in drawable folder and replacing them with ordinary drawables.

How to get column by number in Pandas?

The following is taken from http://pandas.pydata.org/pandas-docs/dev/indexing.html. There are a few more examples... you have to scroll down a little

In [816]: df1

           0         2         4         6
0   0.569605  0.875906 -2.211372  0.974466
2  -2.006747 -0.410001 -0.078638  0.545952
4  -1.219217 -1.226825  0.769804 -1.281247
6  -0.727707 -0.121306 -0.097883  0.695775
8   0.341734  0.959726 -1.110336 -0.619976
10  0.149748 -0.732339  0.687738  0.176444

Select via integer slicing

In [817]: df1.iloc[:3]

          0         2         4         6
0  0.569605  0.875906 -2.211372  0.974466
2 -2.006747 -0.410001 -0.078638  0.545952
4 -1.219217 -1.226825  0.769804 -1.281247

In [818]: df1.iloc[1:5,2:4]

          4         6
2 -0.078638  0.545952
4  0.769804 -1.281247
6 -0.097883  0.695775
8 -1.110336 -0.619976

Select via integer list

In [819]: df1.iloc[[1,3,5],[1,3]]

           2         6
2  -0.410001  0.545952
6  -0.121306  0.695775
10 -0.732339  0.176444

What is an unhandled promise rejection?

In my case was Promise with no reject neither resolve, because my Promise function threw an exception. This mistake cause UnhandledPromiseRejectionWarning message.

PHP page redirect

   $url='the/url/you/want/to/go';
   echo '<META HTTP-EQUIV=REFRESH CONTENT="1; '.$url.'">';

this works for me fine.

How to present UIActionSheet iOS Swift?

Update for Swift 3:

// Create the AlertController and add its actions like button in ActionSheet
let actionSheetController = UIAlertController(title: "Please select", message: "Option to select", preferredStyle: .actionSheet)

let cancelActionButton = UIAlertAction(title: "Cancel", style: .cancel) { action -> Void in
    print("Cancel")
}
actionSheetController.addAction(cancelActionButton)

let saveActionButton = UIAlertAction(title: "Save", style: .default) { action -> Void in
    print("Save")
}
actionSheetController.addAction(saveActionButton)

let deleteActionButton = UIAlertAction(title: "Delete", style: .default) { action -> Void in
    print("Delete")
}
actionSheetController.addAction(deleteActionButton)
self.present(actionSheetController, animated: true, completion: nil)

Compilation fails with "relocation R_X86_64_32 against `.rodata.str1.8' can not be used when making a shared object"

Fixed it with -no-pie option in linker stage:

g++-8 -L"/home/pedro/workspace/project/lib" -no-pie ...

Is it better to use C void arguments "void foo(void)" or not "void foo()"?

C99 quotes

This answer aims to quote and explain the relevant parts of the C99 N1256 standard draft.

Definition of declarator

The term declarator will come up a lot, so let's understand it.

From the language grammar, we find that the following underline characters are declarators:

int f(int x, int y);
    ^^^^^^^^^^^^^^^

int f(int x, int y) { return x + y; }
    ^^^^^^^^^^^^^^^

int f();
    ^^^

int f(x, y) int x; int y; { return x + y; }
    ^^^^^^^

Declarators are part of both function declarations and definitions.

There are 2 types of declarators:

  • parameter type list
  • identifier list

Parameter type list

Declarations look like:

int f(int x, int y);

Definitions look like:

int f(int x, int y) { return x + y; }

It is called parameter type list because we must give the type of each parameter.

Identifier list

Definitions look like:

int f(x, y)
    int x;
    int y;
{ return x + y; }

Declarations look like:

int g();

We cannot declare a function with a non-empty identifier list:

int g(x, y);

because 6.7.5.3 "Function declarators (including prototypes)" says:

3 An identifier list in a function declarator that is not part of a definition of that function shall be empty.

It is called identifier list because we only give the identifiers x and y on f(x, y), types come after.

This is an older method, and shouldn't be used anymore. 6.11.6 Function declarators says:

1 The use of function declarators with empty parentheses (not prototype-format parameter type declarators) is an obsolescent feature.

and the Introduction explains what is an obsolescent feature:

Certain features are obsolescent, which means that they may be considered for withdrawal in future revisions of this International Standard. They are retained because of their widespread use, but their use in new implementations (for implementation features) or new programs (for language [6.11] or library features [7.26]) is discouraged

f() vs f(void) for declarations

When you write just:

void f();

it is necessarily an identifier list declaration, because 6.7.5 "Declarators" says defines the grammar as:

direct-declarator:
    [...]
    direct-declarator ( parameter-type-list )
    direct-declarator ( identifier-list_opt )

so only the identifier-list version can be empty because it is optional (_opt).

direct-declarator is the only grammar node that defines the parenthesis (...) part of the declarator.

So how do we disambiguate and use the better parameter type list without parameters? 6.7.5.3 Function declarators (including prototypes) says:

10 The special case of an unnamed parameter of type void as the only item in the list specifies that the function has no parameters.

So:

void f(void);

is the way.

This is a magic syntax explicitly allowed, since we cannot use a void type argument in any other way:

void f(void v);
void f(int i, void);
void f(void, int);

What can happen if I use an f() declaration?

Maybe the code will compile just fine: 6.7.5.3 Function declarators (including prototypes):

14 The empty list in a function declarator that is not part of a definition of that function specifies that no information about the number or types of the parameters is supplied.

So you can get away with:

void f();
void f(int x) {}

Other times, UB can creep up (and if you are lucky the compiler will tell you), and you will have a hard time figuring out why:

void f();
void f(float x) {}

See: Why does an empty declaration work for definitions with int arguments but not for float arguments?

f() and f(void) for definitions

f() {}

vs

f(void) {}

are similar, but not identical.

6.7.5.3 Function declarators (including prototypes) says:

14 An empty list in a function declarator that is part of a definition of that function specifies that the function has no parameters.

which looks similar to the description of f(void).

But still... it seems that:

int f() { return 0; }
int main(void) { f(1); }

is conforming undefined behavior, while:

int f(void) { return 0; }
int main(void) { f(1); }

is non conforming as discussed at: Why does gcc allow arguments to be passed to a function defined to be with no arguments?

TODO understand exactly why. Has to do with being a prototype or not. Define prototype.

How do I clear all variables in the middle of a Python script?

In the idle IDE there is Shell/Restart Shell. Cntrl-F6 will do it.

Concatenation of strings in Lua

As other answers have said, the string concatenation operator in Lua is two dots.

Your simple example would be written like this:

filename = "checkbook"
filename = filename .. ".tmp"

However, there is a caveat to be aware of. Since strings in Lua are immutable, each concatenation creates a new string object and copies the data from the source strings to it. That makes successive concatenations to a single string have very poor performance.

The Lua idiom for this case is something like this:

function listvalues(s)
    local t = { }
    for k,v in ipairs(s) do
        t[#t+1] = tostring(v)
    end
    return table.concat(t,"\n")
end

By collecting the strings to be concatenated in an array t, the standard library routine table.concat can be used to concatenate them all up (along with a separator string between each pair) without unnecessary string copying.

Update: I just noticed that I originally wrote the code snippet above using pairs() instead of ipairs().

As originally written, the function listvalues() would indeed produce every value from the table passed in, but not in a stable or predictable order. On the other hand, it would include values who's keys were not positive integers in the span of 1 to #s. That is what pairs() does: it produces every single (key,value) pair stored in the table.

In most cases where you would be using something like listvaluas() you would be interested in preserving their order. So a call written as listvalues{13, 42, 17, 4} would produce a string containing those value in that order. However, pairs() won't do that, it will itemize them in some order that depends on the underlying implementation of the table data structure. It is known that the order not only depends on the keys, but also on the order in which the keys were inserted and other keys removed.

Of course ipairs() isn't a perfect answer either. It only enumerates those values of the table that form a "sequence". That is, those values who's keys form an unbroken block spanning from 1 to some upper bound, which is (usually) also the value returned by the # operator. (In many cases, the function ipairs() itself is better replaced by a simpler for loop that just counts from 1 to #s. This is the recommended practice in Lua 5.2 and in LuaJIT where the simpler for loop can be more efficiently implemented than the ipairs() iterator.)

If pairs() really is the right approach, then it is usually the case that you want to print both the key and the value. This reduces the concerns about order by making the data self-describing. Of course, since any Lua type (except nil and the floating point NaN) can be used as a key (and NaN can also be stored as a value) finding a string representation is left as an exercise for the student. And don't forget about trees and more complex structures of tables.

Pass props to parent component in React.js

Update (9/1/15): The OP has made this question a bit of a moving target. It’s been updated again. So, I feel responsible to update my reply.

First, an answer to your provided example:

Yes, this is possible.

You can solve this by updating Child’s onClick to be this.props.onClick.bind(null, this):

var Child = React.createClass({
  render: function () {
    return <a onClick={this.props.onClick.bind(null, this)}>Click me</a>;
  }
});

The event handler in your Parent can then access the component and event like so:

  onClick: function (component, event) {
    // console.log(component, event);
  },

JSBin snapshot


But the question itself is misleading

Parent already knows Child’s props.

This isn’t clear in the provided example because no props are actually being provided. This sample code might better support the question being asked:

var Child = React.createClass({
  render: function () {
    return <a onClick={this.props.onClick}> {this.props.text} </a>;
  }
});

var Parent = React.createClass({
  getInitialState: function () {
    return { text: "Click here" };
  },
  onClick: function (event) {
    // event.component.props ?why is this not available? 
  },
  render: function() {
    return <Child onClick={this.onClick} text={this.state.text} />;
  }
});

It becomes much clearer in this example that you already know what the props of Child are.

JSBin snapshot


If it’s truly about using a Child’s props…

If it’s truly about using a Child’s props, you can avoid any hookup with Child altogether.

JSX has a spread attributes API I often use on components like Child. It takes all the props and applies them to a component. Child would look like this:

var Child = React.createClass({
  render: function () {
    return <a {...this.props}> {this.props.text} </a>;
  }
});

Allowing you to use the values directly in the Parent:

var Parent = React.createClass({
  getInitialState: function () {
    return { text: "Click here" };
  },
  onClick: function (text) {
    alert(text);
  },
  render: function() {
    return <Child onClick={this.onClick.bind(null, this.state.text)} text={this.state.text} />;
  }
});

JSBin snapshot


And there's no additional configuration required as you hookup additional Child components

var Parent = React.createClass({
  getInitialState: function () {
    return {
      text: "Click here",
      text2: "No, Click here",
    };
  },
  onClick: function (text) {
    alert(text);
  },
  render: function() {
    return <div>
      <Child onClick={this.onClick.bind(null, this.state.text)} text={this.state.text} />
      <Child onClick={this.onClick.bind(null, this.state.text2)} text={this.state.text2} />
    </div>;
  }
});

JSBin snapshot

But I suspect that’s not your actual use case. So let’s dig further…


A robust practical example

The generic nature of the provided example is a hard to talk about. I’ve created a component that demonstrations a practical use for the question above, implemented in a very Reacty way:

DTServiceCalculator working example
DTServiceCalculator repo

This component is a simple service calculator. You provide it with a list of services (with names and prices) and it will calculate a total the selected prices.

Children are blissfully ignorant

ServiceItem is the child-component in this example. It doesn’t have many opinions about the outside world. It requires a few props, one of which is a function to be called when clicked.

<div onClick={this.props.handleClick.bind(this.props.index)} />

It does nothing but to call the provided handleClick callback with the provided index[source].

Parents are Children

DTServicesCalculator is the parent-component is this example. It’s also a child. Let’s look.

DTServiceCalculator creates a list of child-component (ServiceItems) and provides them with props [source]. It’s the parent-component of ServiceItem but it`s the child-component of the component passing it the list. It doesn't own the data. So it again delegates handling of the component to its parent-component source

<ServiceItem chosen={chosen} index={i} key={id} price={price} name={name} onSelect={this.props.handleServiceItem} />

handleServiceItem captures the index, passed from the child, and provides it to its parent [source]

handleServiceClick (index) {
  this.props.onSelect(index);
}

Owners know everything

The concept of “Ownership” is an important one in React. I recommend reading more about it here.

In the example I’ve shown, I keep delegating handling of an event up the component tree until we get to the component that owns the state.

When we finally get there, we handle the state selection/deselection like so [source]:

handleSelect (index) {
  let services = […this.state.services];
  services[index].chosen = (services[index].chosen) ? false : true;
  this.setState({ services: services });
}


Conclusion

Try keeping your outer-most components as opaque as possible. Strive to make sure that they have very few preferences about how a parent-component might choose to implement them.

Keep aware of who owns the data you are manipulating. In most cases, you will need to delegate event handling up the tree to the component that owns that state.

Aside: The Flux pattern is a good way to reduce this type of necessary hookup in apps.

How to Set Selected value in Multi-Value Select in Jquery-Select2.?

I get this post is old but there have been changes to how select2 works now and the answer to this question is extremely simple.

To set the values in a multi select2 is as follows

$('#Books_Illustrations').val([1,2,3]).change();

There is no need to specify .select2 in jquery anymore, simply .val

Also there will be times you will not want to fire the change event because you might have some other code that will execute which is what will happen if you use the method above so to get around that you can change the value without firing the change event like so

$('#Books_Illustrations').select2([1,2,3], null, false);

Volley JsonObjectRequest Post request not working

When you working with JsonObject request you need to pass the parameters right after you pass the link in the initialization , take a look on this code :

        HashMap<String, String> params = new HashMap<>();
        params.put("user", "something" );
        params.put("some_params", "something" );

    JsonObjectRequest request = new JsonObjectRequest(Request.Method.POST, "request_URL", new JSONObject(params), new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {

           // Some code 

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            //handle errors
        }
    });


}

How do I upload a file with the JS fetch API?

This is a basic example with comments. The upload function is what you are looking for:

// Select your input type file and store it in a variable
const input = document.getElementById('fileinput');

// This will upload the file after having read it
const upload = (file) => {
  fetch('http://www.example.net', { // Your POST endpoint
    method: 'POST',
    headers: {
      // Content-Type may need to be completely **omitted**
      // or you may need something
      "Content-Type": "You will perhaps need to define a content-type here"
    },
    body: file // This is your file object
  }).then(
    response => response.json() // if the response is a JSON object
  ).then(
    success => console.log(success) // Handle the success response object
  ).catch(
    error => console.log(error) // Handle the error response object
  );
};

// Event handler executed when a file is selected
const onSelectFile = () => upload(input.files[0]);

// Add a listener on your input
// It will be triggered when a file will be selected
input.addEventListener('change', onSelectFile, false);

How to handle login pop up window using Selenium WebDriver?

You can use this Autoit script to handle the login popup:

WinWaitActive("Authentication Required","","10")
If WinExists("Authentication Required") Then
Send("username{TAB}")
Send("Password{Enter}")
EndIf'

"call to undefined function" error when calling class method

Mates,

I stumbled upon this error today while testing a simple script. I am not using "class" function though so it take it with grain of salt. I was calling function before its definition & declaration ...something like this

      try{
             foo();
         }
       catch (exception $e)
           {
            echo "$e->getMessage()";
           }

       function foo(){
                       echo "blah blah blah";
                     }

so php was throwing me error "call to undefined function ".

This kinda seem classic programming error but may help someone in need of clue.

How to check if there exists a process with a given pid in Python?

Look here for windows-specific way of getting full list of running processes with their IDs. It would be something like

from win32com.client import GetObject
def get_proclist():
    WMI = GetObject('winmgmts:')
    processes = WMI.InstancesOf('Win32_Process')
    return [process.Properties_('ProcessID').Value for process in processes]

You can then verify pid you get against this list. I have no idea about performance cost, so you'd better check this if you're going to do pid verification often.

For *NIx, just use mluebke's solution.

Removing elements from an array in C

There are really two separate issues. The first is keeping the elements of the array in proper order so that there are no "holes" after removing an element. The second is actually resizing the array itself.

Arrays in C are allocated as a fixed number of contiguous elements. There is no way to actually remove the memory used by an individual element in the array but the elements can be shifted to fill the hole made by removing an element. For example:

void remove_element(array_type *array, int index, int array_length)
{
   int i;
   for(i = index; i < array_length - 1; i++) array[i] = array[i + 1];
}

Statically allocated arrays can not be resized. Dynamically allocated arrays can be resized with realloc(). This will potentially move the entire array to another location in memory, so all pointers to the array or to its elements will have to be updated. For example:

remove_element(array, index, array_length);  /* First shift the elements, then reallocate */
array_type *tmp = realloc(array, (array_length - 1) * sizeof(array_type) );
if (tmp == NULL && array_length > 1) {
   /* No memory available */
   exit(EXIT_FAILURE);
}
array_length = array_length - 1;
array = tmp;

realloc will return a NULL pointer if the requested size is 0, or if there is an error. Otherwise it returns a pointer to the reallocated array. The temporary pointer is used to detect errors when calling realloc because instead of exiting it is also possible to just leave the original array as it was. When realloc fails to reallocate an array it does not alter the original array.

Note that both of these operations will be fairly slow if the array is large or if a lot of elements are removed. There are other data structures like linked lists and hashes that can be used if efficient insertion and deletion is a priority.

What is the point of "Initial Catalog" in a SQL Server connection string?

This is the initial database of the data source when you connect.

Edited for clarity:

If you have multiple databases in your SQL Server instance and you don't want to use the default database, you need some way to specify which one you are going to use.

JavaScript: Is there a way to get Chrome to break on all errors?

Just about any error will throw an exceptions. The only errors I can think of that wouldn't work with the "pause on exceptions" option are syntax errors, which happen before any of the code gets executed, so there's no place to pause anyway and none of the code will run.

Apparently, Chrome won't pause on the exception if it's inside a try-catch block though. It only pauses on uncaught exceptions. I don't know of any way to change it.

If you just need to know what line the exception happened on (then you could set a breakpoint if the exception is reproducible), the Error object given to the catch block has a stack property that shows where the exception happened.

/usr/lib/libstdc++.so.6: version `GLIBCXX_3.4.15' not found

Same thing with gcc version 4.8.1 (GCC) and libstdc++.so.6.0.18. Had to copy it here /usr/lib/x86_64-linux-gnu on my ubuntu box.

pip install returning invalid syntax

The problem is the OS can’t find Pip. Pip helps you install packages MODIFIED SOME GREAT ANSWERS TO BE BETTER

Method 1 Go to path of python, then search for pip

  1. open cmd.exe
  2. write the following command:

E.g

cd C:\Users\Username\AppData\Local\Programs\Python\Python37-32

In this directory, search pip with python -m pip then install package

E.g

python -m pip install ipywidgets

-m module-name Searches sys.path for the named module and runs the corresponding .py file as a script.

OR

GO TO scripts from CMD. This is where Pip stays :)

cd C:\Users\User name\AppData\Local\Programs\Python\Python37-32\Scripts>

Then

pip install anypackage

Is calling destructor manually always a sign of bad design?

No, you shouldn't call it explicitly because it would be called twice. Once for the manual call and another time when the scope in which the object is declared ends.

Eg.

{
  Class c;
  c.~Class();
}

If you really need to perform the same operations you should have a separate method.

There is a specific situation in which you may want to call a destructor on a dynamically allocated object with a placement new but it doesn't sound something you will ever need.

How to configure Git post commit hook

Hope this helps: http://nrecursions.blogspot.in/2014/02/how-to-trigger-jenkins-build-on-git.html

It's just a matter of using curl to trigger a Jenkins job using the git hooks provided by git.
The command

curl http://localhost:8080/job/someJob/build?delay=0sec

can run a Jenkins job, where someJob is the name of the Jenkins job.

Search for the hooks folder in your hidden .git folder. Rename the post-commit.sample file to post-commit. Open it with Notepad, remove the : Nothing line and paste the above command into it.

That's it. Whenever you do a commit, Git will trigger the post-commit commands defined in the file.

Printing the value of a variable in SQL Developer

SQL Developer seems to only output the DBMS_OUTPUT text when you have explicitly turned on the DBMS_OUTPUT window pane.

Go to (Menu) VIEW -> Dbms_output to invoke the pane.

Click on the Green Plus sign to enable output for your connection and then run the code.

EDIT: Don't forget to set the buffer size according to the amount of output you are expecting.

Converting data frame column from character to numeric

If we need only one column to be numeric

yyz$b <- as.numeric(as.character(yyz$b))

But, if all the columns needs to changed to numeric, use lapply to loop over the columns and convert to numeric by first converting it to character class as the columns were factor.

yyz[] <- lapply(yyz, function(x) as.numeric(as.character(x)))

Both the columns in the OP's post are factor because of the string "n/a". This could be easily avoided while reading the file using na.strings = "n/a" in the read.table/read.csv or if we are using data.frame, we can have character columns with stringsAsFactors=FALSE (the default is stringsAsFactors=TRUE)


Regarding the usage of apply, it converts the dataset to matrix and matrix can hold only a single class. To check the class, we need

lapply(yyz, class)

Or

sapply(yyz, class)

Or check

str(yyz)

Android widget: How to change the text of a button

You can use the setText() method. Example:

import android.widget.Button;

Button p1_button = (Button)findViewById(R.id.Player1);
p1_button.setText("Some text");

Also, just as a point of reference, Button extends TextView, hence why you can use setText() just like with an ordinary TextView.

Creating CSS Global Variables : Stylesheet theme management

I do it this way:

The html:

<head>
    <style type="text/css"> <? require_once('xCss.php'); ?> </style>
</head>

The xCss.php:

<? // place here your vars
$fntBtn = 'bold 14px  Arial'
$colBorder  = '#556677' ;
$colBG0     = '#dddddd' ;
$colBG1     = '#44dddd' ;
$colBtn     = '#aadddd' ;

// here goes your css after the php-close tag: 
?>
button { border: solid 1px <?= $colBorder; ?>; border-radius:4px; font: <?= $fntBtn; ?>; background-color:<?= $colBtn; ?>; } 

MVC Razor Hidden input and passing values

A move from WebForms to MVC requires a complete sea-change in logic and brain processes. You're no longer interacting with the 'form' both server-side and client-side (and in fact even with WebForms you weren't interacting client-side). You've probably just mixed up a bit of thinking there, in that with WebForms and RUNAT="SERVER" you were merely interacting with the building of the Web page.

MVC is somewhat similar in that you have server-side code in constructing the model (the data you need to build what your user will see), but once you have built the HTML you need to appreciate that the link between the server and the user no longer exists. They have a page of HTML, that's it.

So the HTML you are building is read-only. You pass the model through to the Razor page, which will build HTML appropriate to that model.

If you want to have a hidden element which sets true or false depending on whether this is the first view or not you need a bool in your model, and set it to True in the Action if it's in response to a follow up. This could be done by having different actions depending on whether the request is [HttpGet] or [HttpPost] (if that's appropriate for how you set up your form: a GET request for the first visit and a POST request if submitting a form).

Alternatively the model could be set to True when it's created (which will be the first time you visit the page), but after you check the value as being True or False (since a bool defaults to False when it's instantiated). Then using:

@Html.HiddenFor(x => x.HiddenPostBack)

in your form, which will put a hidden True. When the form is posted back to your server the model will now have that value set to True.

It's hard to give much more advice than that as your question isn't specific as to why you want to do this. It's perhaps vital that you read a good book on moving to MVC from WebForms, such as Steve Sanderson's Pro ASP.NET MVC.

How can I set the current working directory to the directory of the script in Bash?

The following also works:

cd "${0%/*}"

The syntax is thoroughly described in this StackOverflow answer.

initialize a vector to zeros C++/C++11

You don't need initialization lists for that:

std::vector<int> vector1(length, 0);
std::vector<double> vector2(length, 0.0);

Microsoft.ReportViewer.Common Version=12.0.0.0

here the link to webreports version 12 https://www.nuget.org/packages/Microsoft.ReportViewer.WebForms.v12/12.0.0?_src=template

after the package installed

on your toolbox browse the dll reference it to bin then that's it run the visual studio

Android Respond To URL in Intent

You might need to allow different combinations of data in your intent filter to get it to work in different cases (http/ vs https/, www. vs no www., etc).

For example, I had to do the following for an app which would open when the user opened a link to Google Drive forms (www.docs.google.com/forms)

Note that path prefix is optional.

        <intent-filter>
            <action android:name="android.intent.action.VIEW" />
            <category android:name="android.intent.category.DEFAULT" />
            <category android:name="android.intent.category.BROWSABLE" />

            <data android:scheme="http" />
            <data android:scheme="https" />

            <data android:host="www.docs.google.com" />
            <data android:host="docs.google.com" />

            <data android:pathPrefix="/forms" />
        </intent-filter>

android.content.res.Resources$NotFoundException: String resource ID #0x0

If we get the value as int and we set it to String, the error occurs. PFB my solution,

Textview = tv_property_count;
int property_id;
tv_property_count.setText(String.valueOf(property_id));

How Can I Set the Default Value of a Timestamp Column to the Current Timestamp with Laravel Migrations?

In laravel 7, to set current time use following:

$table->timestamp('column_name')->useCurrent();

Unicode via CSS :before

The code points used in icon font tricks are usually Private Use code points, which means that they have no generally defined meaning and should not be used in open information interchange, only by private agreement between interested parties. However, Private Use code points can be represented as any other Unicode value, e.g. in CSS using a notation like \f066, as others have answered. You can even enter the code point as such, if your document is UTF-8 encoded and you know how to type an arbitrary Unicode value by its number in your authoring environment (but of course it would normally be displayed using a symbol for an unknown character).

However, this is not the normal way of using icon fonts. Normally you use a CSS file provided with the font and use constructs like <span class="icon-resize-small">foo</span>. The CSS code will then take care of inserting the symbol at the start of the element, and you don’t need to know the code point number.

How to prettyprint a JSON file?

It's far from perfect, but it does the job.

data = data.replace(',"',',\n"')

you can improve it, add indenting and so on, but if you just want to be able to read a cleaner json, this is the way to go.

How / can I display a console window in Intellij IDEA?

  1. Press the left corner button
  2. Choose debug
  3. Click console

enter image description here

enter image description here

Command line .cmd/.bat script, how to get directory of running script

Raymond Chen has a few ideas:

https://devblogs.microsoft.com/oldnewthing/20050128-00/?p=36573

Quoted here in full because MSDN archives tend to be somewhat unreliable:

The easy way is to use the %CD% pseudo-variable. It expands to the current working directory.

set OLDDIR=%CD%
.. do stuff ..
chdir /d %OLDDIR% &rem restore current directory

(Of course, directory save/restore could more easily have been done with pushd/popd, but that's not the point here.)

The %CD% trick is handy even from the command line. For example, I often find myself in a directory where there's a file that I want to operate on but... oh, I need to chdir to some other directory in order to perform that operation.

set _=%CD%\curfile.txt
cd ... some other directory ...
somecommand args %_% args

(I like to use %_% as my scratch environment variable.)

Type SET /? to see the other pseudo-variables provided by the command processor.

Also the comments in the article are well worth scanning for example this one (via the WayBack Machine, since comments are gone from older articles):

http://blogs.msdn.com/oldnewthing/archive/2005/01/28/362565.aspx#362741

This covers the use of %~dp0:

If you want to know where the batch file lives: %~dp0

%0 is the name of the batch file. ~dp gives you the drive and path of the specified argument.

Linking dll in Visual Studio

On Windows you do not link with a .dll file directly – you must use the accompanying .lib file instead. To do that go to Project -> Properties -> Configuration Properties -> Linker -> Additional Dependencies and add path to your .lib as a next line.

You also must make sure that the .dll file is either in the directory contained by the %PATH% environment variable or that its copy is in Output Directory (by default, this is Debug\Release under your project's folder).

If you don't have access to the .lib file, one alternative is to load the .dll manually during runtime using WINAPI functions such as LoadLibrary and GetProcAddress.

How to write ternary operator condition in jQuery?

I think Dan and Nicola have suitable corrected code, however you may not be clear on why the original code didn't work.

What has been called here a "ternary operator" is called a conditional operator in ECMA-262 section 11.12. It has the form:

LogicalORExpression ? AssignmentExpression : AssignmentExpression

The LogicalORExpression is evaluated and the returned value converted to Boolean (just like an expression in an if condition). If it evaluates to true, then the first AssignmentExpression is evaluated and the returned value returned, otherwise the second is evaluated and returned.

The error in the original code is the extra semi-colons that change the attempted conditional operator into a series of statements with syntax errors.

%Like% Query in spring JpaRepository

You can have one alternative of using placeholders as:

@Query("Select c from Registration c where c.place LIKE  %?1%")
List<Registration> findPlaceContainingKeywordAnywhere(String place);

Multiple WHERE Clauses with LINQ extension methods

If you working with in-memory data (read "collections of POCO") you may also stack your expressions together using PredicateBuilder like so:

// initial "false" condition just to start "OR" clause with
var predicate = PredicateBuilder.False<YourDataClass>();

if (condition1)
{
    predicate = predicate.Or(d => d.SomeStringProperty == "Tom");
}

if (condition2)
{
    predicate = predicate.Or(d => d.SomeStringProperty == "Alex");
}

if (condition3)
{
    predicate = predicate.And(d => d.SomeIntProperty >= 4);
}

return originalCollection.Where<YourDataClass>(predicate.Compile());

The full source of mentioned PredicateBuilder is bellow (but you could also check the original page with a few more examples):

using System;
using System.Linq;
using System.Linq.Expressions;
using System.Collections.Generic;

public static class PredicateBuilder
{
  public static Expression<Func<T, bool>> True<T> ()  { return f => true;  }
  public static Expression<Func<T, bool>> False<T> () { return f => false; }

  public static Expression<Func<T, bool>> Or<T> (this Expression<Func<T, bool>> expr1,
                                                      Expression<Func<T, bool>> expr2)
  {
    var invokedExpr = Expression.Invoke (expr2, expr1.Parameters.Cast<Expression> ());
    return Expression.Lambda<Func<T, bool>>
          (Expression.OrElse (expr1.Body, invokedExpr), expr1.Parameters);
  }

  public static Expression<Func<T, bool>> And<T> (this Expression<Func<T, bool>> expr1,
                                                       Expression<Func<T, bool>> expr2)
  {
    var invokedExpr = Expression.Invoke (expr2, expr1.Parameters.Cast<Expression> ());
    return Expression.Lambda<Func<T, bool>>
          (Expression.AndAlso (expr1.Body, invokedExpr), expr1.Parameters);
  }
}

Note: I've tested this approach with Portable Class Library project and have to use .Compile() to make it work:

Where(predicate .Compile() );

Sorting a Dictionary in place with respect to keys

While Dictionary is implemented as a hash table, SortedDictionary is implemented as a Red-Black Tree.

If you don't take advantage of the order in your algorithm and only need to sort the data before output, using SortedDictionary would have negative impact on performance.

You can "sort" the dictionary like this:

Dictionary<string, int> dictionary = new Dictionary<string, int>();
// algorithm
return new SortedDictionary<string, int>(dictionary);

How do I overload the square-bracket operator in C#?

If you're using C# 6 or later, you can use expression-bodied syntax for get-only indexer:

public object this[int i] => this.InnerList[i];

Android Studio Gradle DSL method not found: 'android()' -- Error(17,0)

This error has occurred when i was importing a project from Github. This happens as the project was of older version. Just try to delete these methods below from your root gradle.

android { compileSdkVersion 19 buildToolsVersion "19.1" }

then try again.

I hope it works.

Difference between chr(13) and chr(10)

Chr(10) is the Line Feed character and Chr(13) is the Carriage Return character.

You probably won't notice a difference if you use only one or the other, but you might find yourself in a situation where the output doesn't show properly with only one or the other. So it's safer to include both.


Historically, Line Feed would move down a line but not return to column 1:

This  
    is  
        a  
            test.

Similarly Carriage Return would return to column 1 but not move down a line:

This  
is  
a  
test.

Paste this into a text editor and then choose to "show all characters", and you'll see both characters present at the end of each line. Better safe than sorry.

How to add url parameters to Django template url tag?

I found the answer here: Is it possible to pass query parameters via Django's {% url %} template tag?

Simply add them to the end:

<a href="{% url myview %}?office=foobar">
For Django 1.5+

<a href="{% url 'myview' %}?office=foobar">

[there is nothing else to improve but I'm getting a stupid error when I fix the code ticks]

image size (drawable-hdpi/ldpi/mdpi/xhdpi)

Tablets supports tvdpi and for that scaling factor is 1.33 times dimensions of medium dpi

    ldpi | mdpi | tvdpi | hdpi | xhdpi | xxhdpi | xxxhdpi
    0.75 | 1    | 1.33  | 1.5  | 2     | 3      | 4

This means that if you generate a 400x400 image for xxxhdpi devices, you should generate the same resource in 300x300 for xxhdpi, 200x200 for xhdpi, 133x133 for tvdpi, 150x150 for hdpi, 100x100 for mdpi, and 75x75 for ldpi devices

Build error, This project references NuGet

This problem appeared for me when I was creating folders in the filesystem (not in my solution) and moved some projects around.

Turns out that the package paths are relative from the csproj files. So I had to change the "HintPath" of my references:

<Reference Include="EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089, processorArchitecture=MSIL">
    <HintPath>..\packages\EntityFramework.6.1.3\lib\net45\EntityFramework.dll</HintPath>
    <Private>True</Private>
</Reference>

To:

<Reference Include="EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089, processorArchitecture=MSIL">
    <HintPath>..\..\packages\EntityFramework.6.1.3\lib\net45\EntityFramework.dll</HintPath>
    <Private>True</Private>
</Reference>

Notice the double "..\" in 'HintPath'.

I also had to change my error conditions, for example I had to change:

<Error Condition="!Exists('..\packages\Microsoft.Net.Compilers.1.1.1\build\Microsoft.Net.Compilers.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.Net.Compilers.1.1.1\build\Microsoft.Net.Compilers.props'))" />

To:

<Error Condition="!Exists('..\..\packages\Microsoft.Net.Compilers.1.1.1\build\Microsoft.Net.Compilers.props')" Text="$([System.String]::Format('$(ErrorText)', '..\..\packages\Microsoft.Net.Compilers.1.1.1\build\Microsoft.Net.Compilers.props'))" />

Again, notice the double "..\".

T-SQL Subquery Max(Date) and Joins

SELECT
    MyParts.*,MyPriceDate.Price,MyPriceDate.PriceDate
    FROM MyParts
        INNER JOIN (SELECT Partid, MAX(PriceDate) AS MaxPriceDate FROM MyPrice GROUP BY Partid) dt ON MyParts.Partid = dt.Partid
        INNER JOIN MyPrice ON dt.Partid = MyPrice.Partid AND MyPrice.PriceDate=dt.MaxPriceDate

Program to find prime numbers

You can do this faster using a nearly optimal trial division sieve in one (long) line like this:

Enumerable.Range(0, Math.Floor(2.52*Math.Sqrt(num)/Math.Log(num))).Aggregate(
    Enumerable.Range(2, num-1).ToList(), 
    (result, index) => { 
        var bp = result[index]; var sqr = bp * bp;
        result.RemoveAll(i => i >= sqr && i % bp == 0); 
        return result; 
    }
);

The approximation formula for number of primes used here is p(x) < 1.26 x / ln(x). We only need to test by primes not greater than x = sqrt(num).

Note that the sieve of Eratosthenes has much better run time complexity than trial division (should run much faster for bigger num values, when properly implemented).

Custom Python list sorting

Even better:

student_tuples = [
    ('john', 'A', 15),
    ('jane', 'B', 12),
    ('dave', 'B', 10),
]

sorted(student_tuples, key=lambda student: student[2])   # sort by age
[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

Taken from: https://docs.python.org/3/howto/sorting.html

Can you target an elements parent element using event.target?

To use the parent of an element use parentElement:

function selectedProduct(event){
  var target = event.target;
  var parent = target.parentElement;//parent of "target"
}

Recommended way to insert elements into map

map[key] = value is provided for easier syntax. It is easier to read and write.

The reason for which you need to have default constructor is that map[key] is evaluated before assignment. If key wasn't present in map, new one is created (with default constructor) and reference to it is returned from operator[].

Generate .pem file used to set up Apple Push Notifications

There's much simpler solution today — pem. This tool makes life much easier.

For example, to generate or renew your push notification certificate just enter:

fastlane pem 

and it's done in under a minute. In case you need a sandbox certificate, enter:

fastlane pem --development

And that's pretty it.

Checkout remote branch using git svn

Standard Subversion layout

Create a git clone of that includes your Subversion trunk, tags, and branches with

git svn clone http://svn.example.com/project -T trunk -b branches -t tags

The --stdlayout option is a nice shortcut if your Subversion repository uses the typical structure:

git svn clone http://svn.example.com/project --stdlayout

Make your git repository ignore everything the subversion repo does:

git svn show-ignore >> .git/info/exclude

You should now be able to see all the Subversion branches on the git side:

git branch -r

Say the name of the branch in Subversion is waldo. On the git side, you'd run

git checkout -b waldo-svn remotes/waldo

The -svn suffix is to avoid warnings of the form

warning: refname 'waldo' is ambiguous.

To update the git branch waldo-svn, run

git checkout waldo-svn
git svn rebase

Starting from a trunk-only checkout

To add a Subversion branch to a trunk-only clone, modify your git repository's .git/config to contain

[svn-remote "svn-mybranch"]
        url = http://svn.example.com/project/branches/mybranch
        fetch = :refs/remotes/mybranch

You'll need to develop the habit of running

git svn fetch --fetch-all

to update all of what git svn thinks are separate remotes. At this point, you can create and track branches as above. For example, to create a git branch that corresponds to mybranch, run

git checkout -b mybranch-svn remotes/mybranch

For the branches from which you intend to git svn dcommit, keep their histories linear!


Further information

You may also be interested in reading an answer to a related question.

How to reference a method in javadoc?

The general format, from the @link section of the javadoc documentation, is:

{@link package.class#member label}

Examples

Method in the same class:

/** See also {@link #myMethod(String)}. */
void foo() { ... }

Method in a different class, either in the same package or imported:

/** See also {@link MyOtherClass#myMethod(String)}. */
void foo() { ... }

Method in a different package and not imported:

/** See also {@link com.mypackage.YetAnotherClass#myMethod(String)}. */
void foo() { ... }

Label linked to method, in plain text rather than code font:

/** See also this {@linkplain #myMethod(String) implementation}. */
void foo() { ... }

A chain of method calls, as in your question. We have to specify labels for the links to methods outside this class, or we get getFoo().Foo.getBar().Bar.getBaz(). But these labels can be fragile during refactoring -- see "Labels" below.

/**
 * A convenience method, equivalent to 
 * {@link #getFoo()}.{@link Foo#getBar() getBar()}.{@link Bar#getBaz() getBaz()}.
 * @return baz
 */
public Baz fooBarBaz()

Labels

Automated refactoring may not affect labels. This includes renaming the method, class or package; and changing the method signature.

Therefore, provide a label only if you want different text than the default.

For example, you might link from human language to code:

/** You can also {@linkplain #getFoo() get the current foo}. */
void setFoo( Foo foo ) { ... }

Or you might link from a code sample with text different than the default, as shown above under "A chain of method calls." However, this can be fragile while APIs are evolving.

Type erasure and #member

If the method signature includes parameterized types, use the erasure of those types in the javadoc @link. For example:

int bar( Collection<Integer> receiver ) { ... }

/** See also {@link #bar(Collection)}. */
void foo() { ... }

How to load Spring Application Context

I am using in the way and it is working for me.

public static void main(String[] args) {
    new CarpoolDBAppTest();

}

public CarpoolDBAppTest(){
    ApplicationContext context = new ClassPathXmlApplicationContext("application-context.xml");
    Student stud = (Student) context.getBean("yourBeanId");
}

Here Student is my classm you will get the class matching yourBeanId.

Now work on that object with whatever operation you want to do.

INSERT and UPDATE a record using cursors in oracle

This is a highly inefficient way of doing it. You can use the merge statement and then there's no need for cursors, looping or (if you can do without) PL/SQL.

MERGE INTO studLoad l
USING ( SELECT studId, studName FROM student ) s
ON (l.studId = s.studId)
WHEN MATCHED THEN
  UPDATE SET l.studName = s.studName
   WHERE l.studName != s.studName
WHEN NOT MATCHED THEN 
INSERT (l.studID, l.studName)
VALUES (s.studId, s.studName)

Make sure you commit, once completed, in order to be able to see this in the database.


To actually answer your question I would do it something like as follows. This has the benefit of doing most of the work in SQL and only updating based on the rowid, a unique address in the table.

It declares a type, which you place the data within in bulk, 10,000 rows at a time. Then processes these rows individually.

However, as I say this will not be as efficient as merge.

declare

   cursor c_data is
    select b.rowid as rid, a.studId, a.studName
      from student a
      left outer join studLoad b
        on a.studId = b.studId
       and a.studName <> b.studName
           ;

   type t__data is table of c_data%rowtype index by binary_integer;
   t_data t__data;

begin

   open c_data;
   loop
      fetch c_data bulk collect into t_data limit 10000;

      exit when t_data.count = 0;

      for idx in t_data.first .. t_data.last loop
         if t_data(idx).rid is null then
            insert into studLoad (studId, studName)
            values (t_data(idx).studId, t_data(idx).studName);
         else
            update studLoad
               set studName = t_data(idx).studName
             where rowid = t_data(idx).rid
                   ;
         end if;
      end loop;

   end loop;
   close c_data;

end;
/

exceeds the list view threshold 5000 items in Sharepoint 2010

I had the same problem.please do the following it may help you: By Default List View Threshold set at only 5,000 items this is because of Sharepoint server performance.

To Change the LVT:

  1. Click SharePoint Central Administration,
  2. Go to Application Management
  3. Manage Web Applications
  4. Select your application
  5. Click General Settings at the ribbon
  6. Select Resource Throttling
  7. List View Threshold limit --> change the value to your need.
  8. Also change the List View Threshold for Auditors and Administrators.if you are a administrator.

Click OK to save it.

Specify path to node_modules in package.json

yes you can, just set the NODE_PATH env variable :

export NODE_PATH='yourdir'/node_modules

According to the doc :

If the NODE_PATH environment variable is set to a colon-delimited list of absolute paths, then node will search those paths for modules if they are not found elsewhere. (Note: On Windows, NODE_PATH is delimited by semicolons instead of colons.)

Additionally, node will search in the following locations:

1: $HOME/.node_modules

2: $HOME/.node_libraries

3: $PREFIX/lib/node

Where $HOME is the user's home directory, and $PREFIX is node's configured node_prefix.

These are mostly for historic reasons. You are highly encouraged to place your dependencies locally in node_modules folders. They will be loaded faster, and more reliably.

Source

How to refresh Android listview?

i got some problems with dynamic refresh of my listview.

Call notifyDataSetChanged() on your Adapter.

Some additional specifics on how/when to call notifyDataSetChanged() can be viewed in this Google I/O video.

notifyDataSetChanged() did not work properly in my case[ I called the notifyDataSetChanged from another class]. Just in the case i edited the ListView in the running Activity (Thread). That video thanks to Christopher gave the final hint.

In my second class i used

Runnable run = new Runnable(){
     public void run(){
         contactsActivity.update();
     }
};
contactsActivity.runOnUiThread(run);

to acces the update() from my Activity. This update includes

myAdapter.notifyDataSetChanged();

to tell the Adapter to refresh the view. Worked fine as far as I can say.

What are the differences between if, else, and else if?

I think it helps to think of the "else" as the word OTHERWISE.

so you would read it like this:

if (something is true)
{
   // do stuff
}
otherwise if (some other thing is true)
{
   // do some stuff
}
otherwise
{
   // do some other stuff :)
}

Add a scrollbar to a <textarea>

HTML:

<textarea rows="10" cols="20" id="text"></textarea>

CSS:

#text
{
    overflow-y:scroll;
}

What is the command for cut copy paste a file from one directory to other directory

mv in unix-ish systems, move in dos/windows.

e.g.

C:\> move c:\users\you\somefile.txt   c:\temp\newlocation.txt

and

$ mv /home/you/somefile.txt /tmp/newlocation.txt

Can I change the color of Font Awesome's icon color?

just give and text style whatever you want like :D HTML:

<a href="javascript:;" class="fa fa-trash" style="color:#d9534f;">
   <span style="color:black;">Text Name</span>
</a>

AngularJS- Login and Authentication in each route and controller

You can use resolve:

angular.module('app',[])
.config(function($routeProvider)
{
    $routeProvider
    .when('/', {
        templateUrl  : 'app/views/login.html',
        controller   : 'YourController',
        controllerAs : 'Your',
        resolve: {
            factory : checkLoginRedirect
        }
    })
}

And, the function of the resolve:

function checkLoginRedirect($location){

    var user = firebase.auth().currentUser;

    if (user) {
        // User is signed in.
        if ($location.path() == "/"){
            $location.path('dash'); 
        }

        return true;
    }else{
        // No user is signed in.
        $location.path('/');
        return false;
    }   
}

Firebase also has a method that helps you install an observer, I advise installing it inside a .run:

.run(function(){

    firebase.auth().onAuthStateChanged(function(user) {
        if (user) {
            console.log('User is signed in.');
        } else {
            console.log('No user is signed in.');
        }
    });
  }

ASP.NET Identity DbContext confusion

I would use a single Context class inheriting from IdentityDbContext. This way you can have the context be aware of any relations between your classes and the IdentityUser and Roles of the IdentityDbContext. There is very little overhead in the IdentityDbContext, it is basically a regular DbContext with two DbSets. One for the users and one for the roles.

Handle file download from ajax post

As others have stated, you can create and submit a form to download via a POST request. However, you don't have to do this manually.

One really simple library for doing exactly this is jquery.redirect. It provides an API similar to the standard jQuery.post method:

$.redirect(url, [values, [method, [target]]])

rsync copy over only certain types of files using include option

I think --include is used to include a subset of files that are otherwise excluded by --exclude, rather than including only those files. In other words: you have to think about include meaning don't exclude.

Try instead:

rsync -zarv  --include "*/" --exclude="*" --include="*.sh" "$from" "$to"

For rsync version 3.0.6 or higher, the order needs to be modified as follows (see comments):

rsync -zarv --include="*/" --include="*.sh" --exclude="*" "$from" "$to"

Adding the -m flag will avoid creating empty directory structures in the destination. Tested in version 3.1.2.

So if we only want *.sh files we have to exclude all files --exclude="*", include all directories --include="*/" and include all *.sh files --include="*.sh".

You can find some good examples in the section Include/Exclude Pattern Rules of the man page

python re.split() to split by spaces, commas, and periods, but not in cases like 1,000 or 1.50

Use a negative lookahead and a negative lookbehind:

> s = "one two 3.4 5,6 seven.eight nine,ten"
> parts = re.split('\s|(?<!\d)[,.](?!\d)', s)
['one', 'two', '3.4', '5,6', 'seven', 'eight', 'nine', 'ten']

In other words, you always split by \s (whitespace), and only split by commas and periods if they are not followed (?!\d) or preceded (?<!\d) by a digit.

DEMO.

EDIT: As per @verdesmarald comment, you may want to use the following instead:

> s = "one two 3.4 5,6 seven.eight nine,ten,1.2,a,5"
> print re.split('\s|(?<!\d)[,.]|[,.](?!\d)', s)
['one', 'two', '3.4', '5,6', 'seven', 'eight', 'nine', 'ten', '1.2', 'a', '5']

This will split "1.2,a,5" into ["1.2", "a", "5"].

DEMO.

Scp command syntax for copying a folder from local machine to a remote server

scp -r C:/site user@server_ip:path

path is the place, where site will be copied into the remote server


EDIT: As I said in my comment, try pscp, as you want to use scp using PuTTY.

The other option is WinSCP

How do I update Homebrew?

Alternatively you could update brew by installing it again. (Think I did this as El Capitan changed something)

Note: this is a heavy handed approach that will remove all applications installed via brew!

Try to install brew a fresh and it will tell how to uninstall.

At original time of writing to uninstall:

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/uninstall)"

Edit: As of 2020 to uninstall:

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/uninstall.sh)"

Android Studio cannot resolve R in imported project?

After you tried Clean and Rebuild without success, check your res folder for corrupted files.

In my case a corrupted .png file caused all the trouble.

Reading string by char till end of line C/C++

A text file does not have \0 at the end of lines. It has \n. \n is a character, not a string, so it must be enclosed in single quotes

if (c == '\n')

Why catch and rethrow an exception in C#?

While many of the other answers provide good examples of why you might want to catch an rethrow an exception, no one seems to have mentioned a 'finally' scenario.

An example of this is where you have a method in which you set the cursor (for example to a wait cursor), the method has several exit points (e.g. if () return;) and you want to ensure the cursor is reset at the end of the method.

To do this you can wrap all of the code in a try/catch/finally. In the finally set the cursor back to the right cursor. So that you don't bury any valid exceptions, rethrow it in the catch.

try
{
    Cursor.Current = Cursors.WaitCursor;
    // Test something
    if (testResult) return;
    // Do something else
}
catch
{
    throw;
}
finally
{
     Cursor.Current = Cursors.Default;
}

SQL Server FOR EACH Loop

declare @counter as int
set @counter = 0
declare @date as varchar(50)
set @date = cast(1+@counter as varchar)+'/01/2013'
while(@counter < 12)
begin 
select  cast(1+@counter as varchar)+'/01/2013' as date
set @counter = @counter + 1
end

How to create composite primary key in SQL Server 2008

First create the database and table, manually adding the columns. In which column to be primary key. You should right click this column and set primary key and set the seed value of the primary key.

How to execute python file in linux

1.save your file name as hey.py with the below given hello world script

#! /usr/bin/python
print('Hello, world!')

2.open the terminal in that directory

$ python hey.py

or if you are using python3 then

$ python3 hey.py

Android ADB stop application command like "force-stop" for non rooted device

If you have a rooted device you can use kill command

Connect to your device with adb:

adb shell

Once the session is established, you have to escalade privileges:

su

Then

ps

will list running processes. Note down the PID of the process you want to terminate. Then get rid of it

kill PID

Unrecognized SSL message, plaintext connection? Exception

HERE A VERY IMPORTANT ANSWER:

You just change your API URL String (in your method) from https to http.. This could also be the cause:

client.resource("http://192.168.0.100:8023/jaxrs/tester/tester");

instead of

client.resource("https://192.168.0.100:8023/jaxrs/tester/tester");

Plot two histograms on single chart with matplotlib

In the case you have different sample sizes, it may be difficult to compare the distributions with a single y-axis. For example:

import numpy as np
import matplotlib.pyplot as plt

#makes the data
y1 = np.random.normal(-2, 2, 1000)
y2 = np.random.normal(2, 2, 5000)
colors = ['b','g']

#plots the histogram
fig, ax1 = plt.subplots()
ax1.hist([y1,y2],color=colors)
ax1.set_xlim(-10,10)
ax1.set_ylabel("Count")
plt.tight_layout()
plt.show()

hist_single_ax

In this case, you can plot your two data sets on different axes. To do so, you can get your histogram data using matplotlib, clear the axis, and then re-plot it on two separate axes (shifting the bin edges so that they don't overlap):

#sets up the axis and gets histogram data
fig, ax1 = plt.subplots()
ax2 = ax1.twinx()
ax1.hist([y1, y2], color=colors)
n, bins, patches = ax1.hist([y1,y2])
ax1.cla() #clear the axis

#plots the histogram data
width = (bins[1] - bins[0]) * 0.4
bins_shifted = bins + width
ax1.bar(bins[:-1], n[0], width, align='edge', color=colors[0])
ax2.bar(bins_shifted[:-1], n[1], width, align='edge', color=colors[1])

#finishes the plot
ax1.set_ylabel("Count", color=colors[0])
ax2.set_ylabel("Count", color=colors[1])
ax1.tick_params('y', colors=colors[0])
ax2.tick_params('y', colors=colors[1])
plt.tight_layout()
plt.show()

hist_twin_ax

Changing all files' extensions in a folder with one command on Windows

An alternative way to rename files using the renamer npm package.

below is an example of renaming files extensions

renamer -d --path-element ext --find ts --replace js *

How to set the image from drawable dynamically in android?

This works fine for me.

final R.drawable drawableResources = new R.drawable(); 
final Class<R.drawable> c = R.drawable.class;
final Field[] fields = c.getDeclaredFields();
for (int i=0; i < fields.length;i++) 
{
     resourceId[i] = fields[i].getInt(drawableResources);  
    /* till here you get all the images into the int array resourceId.*/
}
imageview= (ImageView)findViewById(R.id.imageView);
if(your condition)
{
   imageview.setImageResource(resourceId[any]);
}

how to set windows service username and password through commandline

This works:

sc.exe config "[servicename]" obj= "[.\username]" password= "[password]"

Where each of the [bracketed] items are replaced with the true arguments. (Keep the quotes, but don't keep the brackets.)

Just keep in mind that:

  • The spacing in the above example matters. obj= "foo" is correct; obj="foo" is not.
  • '.' is an alias to the local machine, you can specify a domain there (or your local computer name) if you wish.
  • Passwords aren't validated until the service is started
  • Quote your parameters, as above. You can sometimes get by without quotes, but good luck.

Echo equivalent in PowerShell for script testing

PowerShell has aliases for several common commands like echo. Type the following in PowerShell:

Get-Alias echo

to get a response:

CommandType     Name                                               Version    Source
-----------     ----                                               -------    ------
Alias           echo -> Write-Output

Even Get-Alias has an alias gal -> Get-Alias. You could write gal echo to get the alias for echo.

gal echo

Other aliases are listed here: https://docs.microsoft.com/en-us/powershell/scripting/learn/using-familiar-command-names?view=powershell-6

cat dir mount rm cd echo move rmdir chdir erase popd sleep clear h ps sort cls history pushd tee copy kill pwd type del lp r write diff ls ren

PostgreSQL next value of the sequences?

I tried this and it works perfectly

@Entity
public class Shipwreck {
  @Id
  @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "seq")
  @Basic(optional = false)
  @SequenceGenerator(name = "seq", sequenceName = "shipwreck_seq", allocationSize = 1)
  Long id;

....

CREATE SEQUENCE public.shipwreck_seq
    INCREMENT 1
    START 110
    MINVALUE 1
    MAXVALUE 9223372036854775807
    CACHE 1;

Rebase feature branch onto another feature branch

Note: if you were on Branch1, you will with Git 2.0 (Q2 2014) be able to type:

git checkout Branch2
git rebase -

See commit 4f40740 by Brian Gesiak modocache:

rebase: allow "-" short-hand for the previous branch

Teach rebase the same shorthand as checkout and merge to name the branch to rebase the current branch on; that is, that "-" means "the branch we were previously on".

Apache Server (xampp) doesn't run on Windows 10 (Port 80)

This fixed node.js not running on port 80 under Windows 10 as well, I was getting a listen eacces error. Start > Services, find "World Wide Web Publish Service" and disable it, exactly as paaacman described.

How can I get screen resolution in java?

Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
double width = screenSize.getWidth();
double height = screenSize.getHeight();
framemain.setSize((int)width,(int)height);
framemain.setResizable(true);
framemain.setExtendedState(JFrame.MAXIMIZED_BOTH);

How to check if array element is null to avoid NullPointerException in Java

public static void main(String s[])
{
    int firstArray[] = {2, 14, 6, 82, 22};
    int secondArray[] = {3, 16, 12, 14, 48, 96};
    int number = getCommonMinimumNumber(firstArray, secondArray);
    System.out.println("The number is " + number);

}
public static int getCommonMinimumNumber(int firstSeries[], int secondSeries[])
{
    Integer result =0;
    if ( firstSeries.length !=0 && secondSeries.length !=0 )
    {
        series(firstSeries);
        series(secondSeries);
        one : for (int i = 0 ; i < firstSeries.length; i++)
        {
            for (int j = 0; j < secondSeries.length; j++)
                if ( firstSeries[i] ==secondSeries[j])
                {
                    result =firstSeries[i];
                    break one;
                }
                else
                    result = -999;
        }
    }
    else if ( firstSeries == Null || secondSeries == null)
        result =-999;

    else
        result = -999;

    return result;
}

public static int[] series(int number[])
{

    int temp;
    boolean fixed = false;
    while(fixed == false)
    {
        fixed = true;
        for ( int i =0 ; i < number.length-1; i++)
        {
            if ( number[i] > number[i+1])
            {
                temp = number[i+1];
                number[i+1] = number[i];
                number[i] = temp;
                fixed = false;
            }
        }
    }
    /*for ( int i =0 ;i< number.length;i++)
    System.out.print(number[i]+",");*/
    return number;

}

How do I run a node.js app as a background service?

If you are using pm2, you can use it with autorestart set to false:

$ pm2 ecosystem

This will generate a sample ecosystem.config.js:

module.exports = {
  apps: [
    {
      script: './scripts/companies.js',
      autorestart: false,
    },
    {
      script: './scripts/domains.js',
      autorestart: false,
    },
    {
      script: './scripts/technologies.js',
      autorestart: false,
    },
  ],
}

$ pm2 start ecosystem.config.js

docker error - 'name is already in use by container'

Here is how I solved this on ubuntu 18:

  1. $ sudo docker ps -a
  2. copy the container ID

For each container do:

  1. $ sudo docker stop container_ID
  2. $ sudo docker rm container_ID

Running a cron job on Linux every six hours

0 */6 * * *

crontab every 6 hours is a commonly used cron schedule.

How to change dot size in gnuplot

The pointsize command scales the size of points, but does not affect the size of dots.

In other words, plot ... with points ps 2 will generate points of twice the normal size, but for plot ... with dots ps 2 the "ps 2" part is ignored.

You could use circular points (pt 7), which look just like dots.

How do I rename a Git repository?

Have you try changing your project name in package.json and execute command git init to reinitialize the existing Git, instead?

Your existing Git history will still exist.

How to delete rows in tables that contain foreign keys to other tables

From your question, I think it is safe to assume you have CASCADING DELETES turned on.
All that is needed in that case is

DELETE FROM MainTable
WHERE PrimaryKey = ???

You database engine will take care of deleting the corresponding referencing records.

Run Command Prompt Commands

you can use simply write the code in a .bat format extension ,the code of the batch file :

c:/ copy /b Image1.jpg + Archive.rar Image2.jpg

use this c# code :

Process.Start("file_name.bat")

CSS selector for "foo that contains bar"?

No, what you are looking for would be called a parent selector. CSS has none; they have been proposed multiple times but I know of no existing or forthcoming standard including them. You are correct that you would need to use something like jQuery or use additional class annotations to achieve the effect you want.

Here are some similar questions with similar results:

How do I make an HTTP request in Swift?

I am calling the json on login button click

@IBAction func loginClicked(sender : AnyObject) {

    var request = NSMutableURLRequest(URL: NSURL(string: kLoginURL)) // Here, kLogin contains the Login API.

    var session = NSURLSession.sharedSession()

    request.HTTPMethod = "POST"

    var err: NSError?
    request.HTTPBody = NSJSONSerialization.dataWithJSONObject(self.criteriaDic(), options: nil, error: &err) // This Line fills the web service with required parameters.
    request.addValue("application/json", forHTTPHeaderField: "Content-Type")
    request.addValue("application/json", forHTTPHeaderField: "Accept")

    var task = session.dataTaskWithRequest(request, completionHandler: {data, response, error -> Void in
        var strData = NSString(data: data, encoding: NSUTF8StringEncoding)
        var err1: NSError?
        var json2 = NSJSONSerialization.JSONObjectWithData(strData.dataUsingEncoding(NSUTF8StringEncoding), options: .MutableLeaves, error:&err1 ) as NSDictionary

        println("json2 :\(json2)")

        if(err) {
            println(err!.localizedDescription)
        }
        else {
            var success = json2["success"] as? Int
            println("Success: \(success)")
        }
    })

    task.resume()
}

Here, I have made a seperate dictionary for the parameters.

var params = ["format":"json", "MobileType":"IOS","MIN":"f8d16d98ad12acdbbe1de647414495ec","UserName":emailTxtField.text,"PWD":passwordTxtField.text,"SigninVia":"SH"]as NSDictionary
    return params
}

// You can add your own sets of parameter here.

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 23: ordinal not in range(128)

When you get a UnicodeEncodeError, it means that somewhere in your code you convert directly a byte string to a unicode one. By default in Python 2 it uses ascii encoding, and utf8 encoding in Python3 (both may fail because not every byte is valid in either encoding)

To avoid that, you must use explicit decoding.

If you may have 2 different encoding in your input file, one of them accepts any byte (say UTF8 and Latin1), you can try to first convert a string with first and use the second one if a UnicodeDecodeError occurs.

def robust_decode(bs):
    '''Takes a byte string as param and convert it into a unicode one.
First tries UTF8, and fallback to Latin1 if it fails'''
    cr = None
    try:
        cr = bs.decode('utf8')
    except UnicodeDecodeError:
        cr = bs.decode('latin1')
    return cr

If you do not know original encoding and do not care for non ascii character, you can set the optional errors parameter of the decode method to replace. Any offending byte will be replaced (from the standard library documentation):

Replace with a suitable replacement character; Python will use the official U+FFFD REPLACEMENT CHARACTER for the built-in Unicode codecs on decoding and ‘?’ on encoding.

bs.decode(errors='replace')

How do I list loaded plugins in Vim?

:set runtimepath?

This lists the path of all plugins loaded when a file is opened with Vim.

Invoke-customs are only supported starting with android 0 --min-api 26

After hours of struggling, I solved it by including the following within app/build.gradle:

android {
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}

https://github.com/mapbox/mapbox-gl-native/issues/11378

Easy login script without database

There's no reason for not using database for login implementation, the very least you can do is to download and install SQLite if your hosting company does not provide you with enough DB.

Check if Internet Connection Exists with jQuery?

A much simpler solution:

<script language="javascript" src="http://maps.google.com/maps/api/js?v=3.2&sensor=false"></script>

and later in the code:

var online;
// check whether this function works (online only)
try {
  var x = google.maps.MapTypeId.TERRAIN;
  online = true;
} catch (e) {
  online = false;
}
console.log(online);

When not online the google script will not be loaded thus resulting in an error where an exception will be thrown.

TypeScript, Looping through a dictionary

Shortest way to get all dictionary/object values:

Object.keys(dict).map(k => dict[k]);

Passing arguments to an interactive program non-interactively

You can also use printf to pipe the input to your script.

var=val
printf "yes\nno\nmaybe\n$var\n" | ./your_script.sh

Celery Received unregistered task of type (run example)

Try importing the Celery task in a Python Shell - Celery might silently be failing to register your tasks because of a bad import statement.

I had an ImportError exception in my tasks.py file that was causing Celery to not register the tasks in the module. All other module tasks were registered correctly.

This error wasn't evident until I tried importing the Celery task within a Python Shell. I fixed the bad import statement and then the tasks were successfully registered.

Updating PartialView mvc 4

So, say you have your View with PartialView, which have to be updated by button click:

<div class="target">
    @{ Html.RenderAction("UpdatePoints");}
</div>

<input class="button" value="update" />

There are some ways to do it. For example you may use jQuery:

<script type="text/javascript">
    $(function(){    
        $('.button').on("click", function(){        
            $.post('@Url.Action("PostActionToUpdatePoints", "Home")').always(function(){
                $('.target').load('/Home/UpdatePoints');        
            })        
        });
    });        
</script>

PostActionToUpdatePoints is your Action with [HttpPost] attribute, which you use to update points

If you use logic in your action UpdatePoints() to update points, maybe you forgot to add [HttpPost] attribute to it:

[HttpPost]
public ActionResult UpdatePoints()
{    
    ViewBag.points =  _Repository.Points;
    return PartialView("UpdatePoints");
}

Save multiple sheets to .pdf

I recommend adding the following line after the export to PDF:

ThisWorkbook.Sheets("Sheet1").Select

(where eg. Sheet1 is the single sheet you want to be active afterwards)

Leaving multiple sheets in a selected state may cause problems executing some code. (eg. unprotect doesn't function properly when multiple sheets are actively selected.)

Removing items from a ListBox in VB.net

Already tested by me, it works fine

For i =0 To ListBox2.items.count - 1
ListBox2.Items.removeAt(0)
Next

How do I compile jrxml to get jasper?

 **A full example of POM file**.

Command to Build All **Jrxml** to **Jasper File** in maven
If you used eclipse then right click on the project and Run as maven Build and add goals antrun:run@compile-jasper-reports 


compile-jasper-reports is the id you gave in the pom file.
**<id>compile-jasper-reports</id>**




<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.test.jasper</groupId>
  <artifactId>testJasper</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>TestJasper</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>
    <dependency>
        <groupId>net.sf.jasperreports</groupId>
        <artifactId>jasperreports</artifactId>
        <version>6.3.0</version>
    </dependency>
    <dependency>
        <groupId>net.sf.jasperreports</groupId>
        <artifactId>jasperreports-fonts</artifactId>
        <version>6.0.0</version>
    </dependency>
    <dependency>
        <groupId>org.codehaus.groovy</groupId>
        <artifactId>groovy-all</artifactId>
        <version>2.4.6</version>
    </dependency>
    <dependency>
        <groupId>com.itextpdf</groupId>
        <artifactId>itextpdf</artifactId>
        <version>5.5.6</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>


  </dependencies>
    <build>
    <pluginManagement>
    <plugins>
         <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.5</version>
            <configuration>
                <source>1.8</source>
                <target>1.8</target>
            </configuration>
        </plugin>       
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-antrun-plugin</artifactId>
            <version>1.8</version>
            <executions>
                <execution>
                    <id>compile-jasper-reports</id>
                    <goals>
                        <goal>run</goal>
                    </goals>
                    <phase>generate-sources</phase>
                    <configuration>
                        <target>
                            <echo message="Start compile of jasper reports" />
                            <mkdir dir="${project.build.directory}/classes/reports"/>
                            <echo message="${basedir}/src/main/resources/jasper/jasperreports" />
                            <taskdef name="jrc" classname="net.sf.jasperreports.ant.JRAntCompileTask"
                                classpathref="maven.compile.classpath" />
                                <jrc srcdir="${basedir}/src/main/resources/jasper/jasperreports" destdir="${basedir}/src/main/resources/jasper/jasperclassfile"
                                  xmlvalidation="true">
                                <classpath refid="maven.compile.classpath"/>
                                <include name="**/*.jrxml" />
                            </jrc>
                        </target>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
    </pluginManagement>
</build>
</project>

Best way to randomize an array with .NET

private ArrayList ShuffleArrayList(ArrayList source)
{
    ArrayList sortedList = new ArrayList();
    Random generator = new Random();

    while (source.Count > 0)
    {
        int position = generator.Next(source.Count);
        sortedList.Add(source[position]);
        source.RemoveAt(position);
    }  
    return sortedList;
}

Cannot open Windows.h in Microsoft Visual Studio

If you are targeting Windows XP (v140_xp), try installing Windows XP Support for C++.

Starting with Visual Studio 2012, the default toolset (v110) dropped support for Windows XP. As a result, a Windows.h error can occur if your project is targeting Windows XP with the default C++ packages.

Check which Windows SDK version is specified in your project's Platform Toolset. (Project ? Properties ? Configuration Properties ? General). If your Toolset ends in _xp, you'll need to install XP support.

Visual Studio: Project toolset

Open the Visual Studio Installer and click Modify for your version of Visual Studio. Open the Individual Components tab and scroll down to Compilers, build tools, and runtimes. Near the bottom, check Windows XP support for C++ and click Modify to begin installing.

Visual Studio Installer: XP Support for C++

See Also:

float:left; vs display:inline; vs display:inline-block; vs display:table-cell;

I prefer inline-block, although float is also useful. Table-cell isn't rendered correctly by old IEs (neither does inline-block, but there's the zoom: 1; *display: inline hack that I use frequently). If you have children that have a smaller height than their parent, floats will bring them to the top, whereas inline-block will screw up sometimes.

Most of the time, the browser will interpret everything correctly, unless, of course, it's IE. You always have to check to make sure that IE doesn't suck-- for example, the table-cell concept.

In all reality, yes, it boils down to personal preference.

One technique you could use to get rid of white space would be to set a font-size of 0 to the parent, then give the font-size back to the children, although that's a hassle, and gross.

ImportError: No module named - Python

For the Python module import to work, you must have "src" in your path, not "gen_py/lib".

When processing an import like import gen_py.lib, it looks for a module gen_py, then looks for a submodule lib.

As the module gen_py won't be in "../gen_py/lib" (it'll be in ".."), the path you added will do nothing to help the import process.

Depending on where you're running it from, try adding the relative path to the "src" folder. Perhaps it's sys.path.append('..'). You might also have success running the script while inside the src folder directly, via relative paths like python main/MyServer.py

How can I make the computer beep in C#?

The solution would be,

Console.Beep

How to pull specific directory with git

In an empty directory:

git init
git remote add [REMOTE_NAME] [GIT_URL]
git fetch REMOTE_NAME
git checkout REMOTE_NAME/BRANCH -- path/to/directory

javax.persistence.PersistenceException: No Persistence provider for EntityManager named customerManager

I was facing the same issue. I realised that I was using the Wrong provider class in persistence.xml

For Hibernate it should be

<provider>org.hibernate.ejb.HibernatePersistence</provider>

And for EclipseLink it should be

<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>

Media Queries: How to target desktop, tablet, and mobile?

It's not a matter of pixels count, it's a matter of actual size (in mm or inches) of characters on the screen, which depends on pixels density. Hence "min-width:" and "max-width:" are useless. A full explanation of this issue is here: what exactly is device pixel ratio?

"@media" queries take into account the pixels count and the device pixel ratio, resulting in a "virtual resolution" which is what you have to actually take into account while designing your page: if your font is 10px fixed-width and the "virtual horizontal resolution" is 300 px, 30 characters will be needed to fill a line.

Using XPATH to search text containing &nbsp;

Bear in mind that a standards-compliant XML processor will have replaced any entity references other than XML's five standard ones (&amp;, &gt;, &lt;, &apos;, &quot;) with the corresponding character in the target encoding by the time XPath expressions are evaluated. Given that behavior, PhiLho's and jsulak's suggestions are the way to go if you want to work with XML tools. When you enter &#160; in the XPath expression, it should be converted to the corresponding byte sequence before the XPath expression is applied.

how to create a logfile in php?

This is my working code. Thanks to Paulo for the links. You create a custom error handler and call the trigger_error function with the correct $errno exception, even if it's not an error. Make sure you can write to the log file directory without administrator access.

<?php
    $logfile_dir = "C:\workspace\logs\\";   // or "/var/log/" for Linux
    $logfile = $logfile_dir . "php_" . date("y-m-d") . ".log";
    $logfile_delete_days = 30;

    function error_handler($errno, $errstr, $errfile, $errline)
    {
        global $logfile_dir, $logfile, $logfile_delete_days;

        if (!(error_reporting() & $errno)) {
            // This error code is not included in error_reporting, so let it fall
            // through to the standard PHP error handler
            return false;
        }

        $filename = basename($errfile);

        switch ($errno) {
            case E_USER_ERROR:
                file_put_contents($logfile, date("y-m-d H:i:s.").gettimeofday()["usec"] . " $filename ($errline): " . "ERROR >> message = [$errno] $errstr\n", FILE_APPEND | LOCK_EX);
                exit(1);
                break;

            case E_USER_WARNING:
                file_put_contents($logfile, date("y-m-d H:i:s.").gettimeofday()["usec"] . " $filename ($errline): " . "WARNING >> message = $errstr\n", FILE_APPEND | LOCK_EX);
                break;

            case E_USER_NOTICE:
                file_put_contents($logfile, date("y-m-d H:i:s.").gettimeofday()["usec"] . " $filename ($errline): " . "NOTICE >> message = $errstr\n", FILE_APPEND | LOCK_EX);
                break;

            default:
                file_put_contents($logfile, date("y-m-d H:i:s.").gettimeofday()["usec"] . " $filename ($errline): " . "UNKNOWN >> message = $errstr\n", FILE_APPEND | LOCK_EX);
                break;
        }

        // delete any files older than 30 days
        $files = glob($logfile_dir . "*");
        $now   = time();

        foreach ($files as $file)
            if (is_file($file))
                if ($now - filemtime($file) >= 60 * 60 * 24 * $logfile_delete_days)
                    unlink($file);

        return true;    // Don't execute PHP internal error handler
    }

    set_error_handler("error_handler");

    trigger_error("testing 1,2,3", E_USER_NOTICE);
?>

Deserialize Java 8 LocalDateTime with JacksonMapper

The date time you're passing is not a iso local date time format.

Change to

@Column(name = "start_date")
@DateTimeFormat(iso = DateTimeFormatter.ISO_LOCAL_DATE_TIME)
@JsonFormat(pattern = "YYYY-MM-dd HH:mm")
private LocalDateTime startDate;

and pass date string in the format '2011-12-03T10:15:30'.

But if you still want to pass your custom format, use just have to specify the right formatter.

Change to

@Column(name = "start_date")
@DateTimeFormat(iso = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm"))
@JsonFormat(pattern = "YYYY-MM-dd HH:mm")
private LocalDateTime startDate;

I think your problem is the @DateTimeFormat has no effect at all. As the jackson is doing the deseralization and it doesnt know anything about spring annotation and I dont see spring scanning this annotation in the deserialization context.

Alternatively, you can try setting the formatter while registering the java time module.

LocalDateTimeDeserializer localDateTimeDeserializer = new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm"));
module.addDeserializer(LocalDateTime.class, localDateTimeDeserializer);

Here is the test case with the deseralizer which works fine. May be try to get rid of that DateTimeFormat annotation altogether.

@RunWith(JUnit4.class)
public class JacksonLocalDateTimeTest {

    private ObjectMapper objectMapper;

    @Before
    public void init() {
        JavaTimeModule module = new JavaTimeModule();
        LocalDateTimeDeserializer localDateTimeDeserializer =  new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm"));
        module.addDeserializer(LocalDateTime.class, localDateTimeDeserializer);
        objectMapper = Jackson2ObjectMapperBuilder.json()
                .modules(module)
                .featuresToDisable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
                .build();
    }

    @Test
    public void test() throws IOException {
        final String json = "{ \"date\": \"2016-11-08 12:00\" }";
        final JsonType instance = objectMapper.readValue(json, JsonType.class);

        assertEquals(LocalDateTime.parse("2016-11-08 12:00",DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm") ), instance.getDate());
    }
}


class JsonType {
    private LocalDateTime date;

    public LocalDateTime getDate() {
        return date;
    }

    public void setDate(LocalDateTime date) {
        this.date = date;
    }
}

How to debug SSL handshake using cURL?

I have used this command to troubleshoot client certificate negotiation:

openssl s_client -connect www.test.com:443 -prexit

The output will probably contain "Acceptable client certificate CA names" and a list of CA certificates from the server, or possibly "No client certificate CA names sent", if the server doesn't always require client certificates.

C#: calling a button event handler method without actually clicking the button

btnTest_Click(null, null);

Provided that the method isn't using either of these parameters (it's very common not to.)

To be honest though this is icky. If you have code that needs to be called you should follow the following convention:

protected void btnTest_Click(object sender, EventArgs e)
{
   SomeSub();
}

protected void SomeOtherFunctionThatNeedsToCallTheCode()
{
   SomeSub();
}

protected void SomeSub()
{
   // ...
}

Perfect 100% width of parent container for a Bootstrap input?

For anyone Googling this, one suggestion is to remove all the input-group class instances. Worked for me in a similar situation. Original code:

_x000D_
_x000D_
<form>_x000D_
  <div class="bs-callout">_x000D_
    <div class="row">_x000D_
      <div class="col-md-4">_x000D_
        <div class="form-group">_x000D_
          <div class="input-group">_x000D_
            <input type="text" class="form-control" name="time" placeholder="Time">_x000D_
          </div>_x000D_
        </div>_x000D_
      </div>_x000D_
      <div class="col-md-8">_x000D_
        <div class="form-group">_x000D_
          <div class="input-group">_x000D_
            <select name="dtarea" class="form-control">_x000D_
              <option value="1">Option value 1</option>_x000D_
            </select>_x000D_
          </div>_x000D_
        </div>_x000D_
      </div>_x000D_
    </div>_x000D_
    <div class="row">_x000D_
      <div class="input-group">_x000D_
        <input type="text" name="reason" class="form-control" placeholder="Reason">_x000D_
      </div>_x000D_
    </div>_x000D_
  </div>_x000D_
</form>
_x000D_
_x000D_
_x000D_ With input-group

New code:

_x000D_
_x000D_
<form>_x000D_
  <div class="bs-callout">_x000D_
    <div class="row">_x000D_
      <div class="col-md-4">_x000D_
        <div class="form-group">_x000D_
          <input type="text" class="form-control" name="time" placeholder="Time">_x000D_
        </div>_x000D_
      </div>_x000D_
      <div class="col-md-8">_x000D_
        <div class="form-group">_x000D_
          <select name="dtarea" class="form-control">_x000D_
            <option value="1">Option value 1</option>_x000D_
          </select>_x000D_
        </div>_x000D_
      </div>_x000D_
    </div>_x000D_
    <div class="row">_x000D_
      <input type="text" name="reason" class="form-control" placeholder="Reason">_x000D_
    </div>_x000D_
  </div>_x000D_
</form>
_x000D_
_x000D_
_x000D_ Without input-group

ASP.NET MVC Bundle not rendering script files on staging server. It works on development server

Whenever I set debug="off" in my web.config and run my mvc4 application i would end up with ...

<script src="/bundles/jquery?v=<some long string>"></script>

in my html code and a JavaScript error

Expected ';'

There were 2 ways to get rid of the javascript error

  1. set BundleTable.EnableOptimizations = false in BundleConfig.cs

OR

  1. I ended up using NuGet Package Manager to update WebGrease.dll. It works fine irrespective if debug= "true" or debug = "false".

Convert Float to Int in Swift

Use a function style conversion (found in section labeled "Integer and Floating-Point Conversion" from "The Swift Programming Language."[iTunes link])

  1> Int(3.4)
$R1: Int = 3

Using CMake with GNU Make: How can I see the exact commands?

I was trying something similar to ensure the -ggdb flag was present.

Call make in a clean directory and grep the flag you are looking for. Looking for debug rather than ggdb I would just write.

make VERBOSE=1 | grep debug

The -ggdb flag was obscure enough that only the compile commands popped up.

What does %s mean in a python format string?

%s indicates a conversion type of string when using python's string formatting capabilities. More specifically, %s converts a specified value to a string using the str() function. Compare this with the %r conversion type that uses the repr() function for value conversion.

Take a look at the docs for string formatting.

Add new field to every document in a MongoDB collection

Pymongo 3.9+

update() is now deprecated and you should use replace_one(), update_one(), or update_many() instead.

In my case I used update_many() and it solved my issue:

db.your_collection.update_many({}, {"$set": {"new_field": "value"}}, upsert=False, array_filters=None)

From documents

update_many(filter, update, upsert=False, array_filters=None, bypass_document_validation=False, collation=None, session=None)


filter: A query that matches the documents to update.

update: The modifications to apply.

upsert (optional): If True, perform an insert if no documents match the filter.

bypass_document_validation (optional): If True, allows the write to opt-out of document level validation. Default is False.

collation (optional): An instance of Collation. This option is only supported on MongoDB 3.4 and above.

array_filters (optional): A list of filters specifying which array elements an update should apply. Requires MongoDB 3.6+.

session (optional): a ClientSession.

How to create an HTTPS server in Node.js?

If you need it only locally for local development, I've created utility exactly for this task - https://github.com/pie6k/easy-https

import { createHttpsDevServer } from 'easy-https';

async function start() {
  const server = await createHttpsDevServer(
    async (req, res) => {
      res.statusCode = 200;
      res.write('ok');
      res.end();
    },
    {
      domain: 'my-app.dev',
      port: 3000,
      subdomains: ['test'], // will add support for test.my-app.dev
      openBrowser: true,
    },
  );
}

start();

It:

  • Will automatically add proper domain entries to /etc/hosts
  • Will ask you for admin password only if needed on first run / domain change
  • Will prepare https certificates for given domains
  • Will trust those certificates on your local machine
  • Will open the browser on start pointing to your local server https url

Select all from table with Laravel and Eloquent

Well, to do it with eloquent you would do:

Blog:all();

From within your Model you do:

return DB::table('posts')->get();

http://laravel.com/docs/queries