Programs & Examples On #App bundle

WebSocket with SSL

1 additional caveat (besides the answer by kanaka/peter): if you use WSS, and the server certificate is not acceptable to the browser, you may not get any browser rendered dialog (like it happens for Web pages). This is because WebSockets is treated as a so-called "subresource", and certificate accept / security exception / whatever dialogs are not rendered for subresources.

How to get a list of user accounts using the command line in MySQL?

to avoid repetitions of users when they connect from different origin:

select distinct User from mysql.user;

Changing background color of selected cell?

I finally managed to get this to work in a table view with style set to Grouped.

First set the selectionStyle property of all cells to UITableViewCellSelectionStyleNone.

cell.selectionStyle = UITableViewCellSelectionStyleNone;

Then implement the following in your table view delegate:

static NSColor *SelectedCellBGColor = ...;
static NSColor *NotSelectedCellBGColor = ...;

- (NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSIndexPath *currentSelectedIndexPath = [tableView indexPathForSelectedRow];
    if (currentSelectedIndexPath != nil)
    {
        [[tableView cellForRowAtIndexPath:currentSelectedIndexPath] setBackgroundColor:NotSelectedCellBGColor];
    }

    return indexPath;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [[tableView cellForRowAtIndexPath:indexPath] setBackgroundColor:SelectedCellBGColor];
}

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (cell.isSelected == YES)
    {
        [cell setBackgroundColor:SelectedCellBGColor];
    }
    else
    {
        [cell setBackgroundColor:NotSelectedCellBGColor];
    }
}

How do I URl encode something in Node.js?

Note that URI encoding is good for the query part, it's not good for the domain. The domain gets encoded using punycode. You need a library like URI.js to convert between a URI and IRI (Internationalized Resource Identifier).

This is correct if you plan on using the string later as a query string:

> encodeURIComponent("http://examplé.org/rosé?rosé=rosé")
'http%3A%2F%2Fexampl%C3%A9.org%2Fros%C3%A9%3Fros%C3%A9%3Dros%C3%A9'

If you don't want ASCII characters like /, : and ? to be escaped, use encodeURI instead:

> encodeURI("http://examplé.org/rosé?rosé=rosé")
'http://exampl%C3%A9.org/ros%C3%A9?ros%C3%A9=ros%C3%A9'

However, for other use-cases, you might need uri-js instead:

> var URI = require("uri-js");
undefined
> URI.serialize(URI.parse("http://examplé.org/rosé?rosé=rosé"))
'http://xn--exampl-gva.org/ros%C3%A9?ros%C3%A9=ros%C3%A9'

jQuery: Currency Format Number

function converter()
{

var number = $(.number).text();

var number = 'Rp. '+number;

s(.number).val(number);
}

Undo git pull, how to bring repos to old state

you can do git reset --hard ORIG_HEAD

since "pull" or "merge" set ORIG_HEAD to be the current state before doing those actions.

What is App.config in C#.NET? How to use it?

Simply, App.config is an XML based file format that holds the Application Level Configurations.

Example:

<?xml version="1.0"?>
<configuration>
  <appSettings>
    <add key="key" value="test" />
  </appSettings>
</configuration>

You can access the configurations by using ConfigurationManager as shown in the piece of code snippet below:

var value = System.Configuration.ConfigurationManager.AppSettings["key"];
// value is now "test"

Note: ConfigurationSettings is obsolete method to retrieve configuration information.

var value = System.Configuration.ConfigurationSettings.AppSettings["key"];

Show just the current branch in Git

You may be interested in the output of

git symbolic-ref HEAD

In particular, depending on your needs and layout you may wish to do

basename $(git symbolic-ref HEAD)

or

git symbolic-ref HEAD | cut -d/ -f3-

and then again there is the .git/HEAD file which may also be of interest for you.

Get a list of all git commits, including the 'lost' ones

Not particularly easily- if you've lost the pointer to the tip of a branch, it's rather like finding a needle in a haystack. You can find all the commits that don't appear to be referenced any more- git fsck --unreachable will do this for you- but that will include commits that you threw away after a git commit --amend, old commits on branches that you rebased etc etc. So seeing all these commits at once is quite likely far too much information to wade through.

So the flippant answer is, don't lose track of things you're interested in. More seriously, the reflogs will hold references to all the commits you've used for the last 60 days or so by default. More importantly, they will give some context about what those commits are.

How to find the Target *.exe file of *.appref-ms

Simple answer to this; I was trying to figure out the same thing, and it just hit me.

GitHub IS a program installed on your computer, and when it runs, it WILL use threads and RAM. So that makes it a process. All you have to do is open Task Manager, click the Processes tab, find 'Github.exe', right click, Open File Location. Voila! Mine is in some App folder in Local, about 4 layers deep.

Screenshot

VBA Macro to compare all cells of two Excel files

Do NOT loop through all cells!! There is a lot of overhead in communications between worksheets and VBA, for both reading and writing. Looping through all cells will be agonizingly slow. I'm talking hours.

Instead, load an entire sheet at once into a Variant array. In Excel 2003, this takes about 2 seconds (and 250 MB of RAM). Then you can loop through it in no time at all.

In Excel 2007 and later, sheets are about 1000 times larger (1048576 rows × 16384 columns = 17 billion cells, compared to 65536 rows × 256 columns = 17 million in Excel 2003). You will run into an "Out of memory" error if you try to load the whole sheet into a Variant; on my machine I can only load 32 million cells at once. So you have to limit yourself to the range you know has actual data in it, or load the sheet bit by bit, e.g. 30 columns at a time.

Option Explicit

Sub test()

    Dim varSheetA As Variant
    Dim varSheetB As Variant
    Dim strRangeToCheck As String
    Dim iRow As Long
    Dim iCol As Long

    strRangeToCheck = "A1:IV65536"
    ' If you know the data will only be in a smaller range, reduce the size of the ranges above.
    Debug.Print Now
    varSheetA = Worksheets("Sheet1").Range(strRangeToCheck)
    varSheetB = Worksheets("Sheet2").Range(strRangeToCheck) ' or whatever your other sheet is.
    Debug.Print Now

    For iRow = LBound(varSheetA, 1) To UBound(varSheetA, 1)
        For iCol = LBound(varSheetA, 2) To UBound(varSheetA, 2)
            If varSheetA(iRow, iCol) = varSheetB(iRow, iCol) Then
                ' Cells are identical.
                ' Do nothing.
            Else
                ' Cells are different.
                ' Code goes here for whatever it is you want to do.
            End If
        Next iCol
    Next iRow

End Sub

To compare to a sheet in a different workbook, open that workbook and get the sheet as follows:

Set wbkA = Workbooks.Open(filename:="C:\MyBook.xls")
Set varSheetA = wbkA.Worksheets("Sheet1") ' or whatever sheet you need

What are the nuances of scope prototypal / prototypical inheritance in AngularJS?

I would like to add an example of prototypical inheritance with javascript to @Scott Driscoll answer. We'll be using classical inheritance pattern with Object.create() which is a part of EcmaScript 5 specification.

First we create "Parent" object function

function Parent(){

}

Then add a prototype to "Parent" object function

 Parent.prototype = {
 primitive : 1,
 object : {
    one : 1
   }
}

Create "Child" object function

function Child(){

}

Assign child prototype (Make child prototype inherit from parent prototype)

Child.prototype = Object.create(Parent.prototype);

Assign proper "Child" prototype constructor

Child.prototype.constructor = Child;

Add method "changeProps" to a child prototype, which will rewrite "primitive" property value in Child object and change "object.one" value both in Child and Parent objects

Child.prototype.changeProps = function(){
    this.primitive = 2;
    this.object.one = 2;
};

Initiate Parent (dad) and Child (son) objects.

var dad = new Parent();
var son = new Child();

Call Child (son) changeProps method

son.changeProps();

Check the results.

Parent primitive property did not change

console.log(dad.primitive); /* 1 */

Child primitive property changed (rewritten)

console.log(son.primitive); /* 2 */

Parent and Child object.one properties changed

console.log(dad.object.one); /* 2 */
console.log(son.object.one); /* 2 */

Working example here http://jsbin.com/xexurukiso/1/edit/

More info on Object.create here https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Object/create

Assign output to variable in Bash

Same with something more complex...getting the ec2 instance region from within the instance.

INSTANCE_REGION=$(curl -s 'http://169.254.169.254/latest/dynamic/instance-identity/document' | python -c "import sys, json; print json.load(sys.stdin)['region']")

echo $INSTANCE_REGION

How can I scroll a web page using selenium webdriver in python?

You can use

driver.execute_script("window.scrollTo(0, Y)") 

where Y is the height (on a fullhd monitor it's 1080). (Thanks to @lukeis)

You can also use

driver.execute_script("window.scrollTo(0, document.body.scrollHeight);")

to scroll to the bottom of the page.

If you want to scroll to a page with infinite loading, like social network ones, facebook etc. (thanks to @Cuong Tran)

SCROLL_PAUSE_TIME = 0.5

# Get scroll height
last_height = driver.execute_script("return document.body.scrollHeight")

while True:
    # Scroll down to bottom
    driver.execute_script("window.scrollTo(0, document.body.scrollHeight);")

    # Wait to load page
    time.sleep(SCROLL_PAUSE_TIME)

    # Calculate new scroll height and compare with last scroll height
    new_height = driver.execute_script("return document.body.scrollHeight")
    if new_height == last_height:
        break
    last_height = new_height

another method (thanks to Juanse) is, select an object and

label.sendKeys(Keys.PAGE_DOWN);

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

If you are looking to style a file input element, look at open file dialog box in javascript. If you are looking to grab the files associated with a file input element, you must do something like this:

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

See this MDN article for more info on the FileList type.

Note that the code above will only work in browsers that support the File API. For IE9 and earlier, for example, you only have access to the file name. The input element has no files property in non-File API browsers.

How to display an unordered list in two columns?

more one answer after a few years!

in this article: http://csswizardry.com/2010/02/mutiple-column-lists-using-one-ul/

HTML:

<ul id="double"> <!-- Alter ID accordingly -->
  <li>CSS</li>
  <li>XHTML</li>
  <li>Semantics</li>
  <li>Accessibility</li>
  <li>Usability</li>
  <li>Web Standards</li>
  <li>PHP</li>
  <li>Typography</li>
  <li>Grids</li>
  <li>CSS3</li>
  <li>HTML5</li>
  <li>UI</li>
</ul>

CSS:

ul{
  width:760px;
  margin-bottom:20px;
  overflow:hidden;
  border-top:1px solid #ccc;
}
li{
  line-height:1.5em;
  border-bottom:1px solid #ccc;
  float:left;
  display:inline;
}
#double li  { width:50%;}
#triple li  { width:33.333%; }
#quad li    { width:25%; }
#six li     { width:16.666%; }

How to extract text from a PDF file?

pdftotext is the best and simplest one! pdftotext also reserves the structure as well.

I tried PyPDF2, PDFMiner and a few others but none of them gave a satisfactory result.

Logical XOR operator in C++?

For a true logical XOR operation, this will work:

if(!A != !B) {
    // code here
}

Note the ! are there to convert the values to booleans and negate them, so that two unequal positive integers (each a true) would evaluate to false.

How to "set a breakpoint in malloc_error_break to debug"

In your screenshot, you didn't specify any module: try setting "libsystem_c.dylib"

enter image description here

I did that, and it works : breakpoint stops here (although the stacktrace often rise from some obscure system lib...)

jasmine: Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL

It looks like the test is waiting for some callback that never comes. It's likely because the test is not executed with asynchronous behavior.

First, see if just using fakeAsync in your "it" scenario:

it('should do something', fakeAsync(() => {

You can also use flush() to wait for the microTask queue to finish or tick() to wait a specified amount of time.

Preferred way of loading resources in Java

Work out the solution according to what you want...

There are two things that getResource/getResourceAsStream() will get from the class it is called on...

  1. The class loader
  2. The starting location

So if you do

this.getClass().getResource("foo.txt");

it will attempt to load foo.txt from the same package as the "this" class and with the class loader of the "this" class. If you put a "/" in front then you are absolutely referencing the resource.

this.getClass().getResource("/x/y/z/foo.txt")

will load the resource from the class loader of "this" and from the x.y.z package (it will need to be in the same directory as classes in that package).

Thread.currentThread().getContextClassLoader().getResource(name)

will load with the context class loader but will not resolve the name according to any package (it must be absolutely referenced)

System.class.getResource(name)

Will load the resource with the system class loader (it would have to be absolutely referenced as well, as you won't be able to put anything into the java.lang package (the package of System).

Just take a look at the source. Also indicates that getResourceAsStream just calls "openStream" on the URL returned from getResource and returns that.

How to create a template function within a class? (C++)

Your guess is the correct one. The only thing you have to remember is that the member function template definition (in addition to the declaration) should be in the header file, not the cpp, though it does not have to be in the body of the class declaration itself.

Bootstrap: add margin/padding space between columns

Update 2018

Bootstrap 4 now has spacing utilities that make adding (or substracting) the space (gutter) between columns easier. Extra CSS isn't necessary.

<div class="row">
    <div class="text-center col-md-6">
        <div class="mr-2">Widget 1</div>
    </div>
    <div class="text-center col-md-6">
        <div class="ml-2">Widget 2</div>
    </div>
</div>

You can adjust margins on the column contents using the margin utils such as ml-0 (margin-left:0), mr-0 (margin-right:0), mx-1 (.25rem left & right margins), etc...

Or, you can adjust padding on the columns (col-*) using the padding utils such as pl-0 (padding-left:0), pr-0 (padding-right:0), px-2 (.50rem left & right padding), etc...

Bootstrap 4 Column Spacing Demo

Notes

  • Changing the left/right margin(s) on col-* will break the grid.
  • Change the left/right margin(s) on the content of col-* works.
  • Change the left/right padding on the col-* also works.

Add ArrayList to another ArrayList in java

The problem you have is caused that you use the same ArrayList NodeList over all iterations in main for loop. Each iterations NodeList is enlarged by new elements.

  1. After first loop, NodeList has 5 elements (PropertyStart,a,b,c,PropertyEnd) and list has 1 element (NodeList: (PropertyStart,a,b,c,PropertyEnd))

  2. After second loop NodeList has 10 elements (PropertyStart,a,b,c,PropertyEnd,PropertyStart,d,e,f,PropertyEnd) and list has 2 elements (NodeList (with 10 elements), NodeList (with 10 elements))

To get you expectations you must replace

NodeList.addAll(nodes);
list.add(NodeList)

by

List childrenList = new ArrayList(nodes);
list.add(childrenList);

PS. Your code is not readable, keep Java code conventions to have readble code. For example is hard to recognize if NodeList is a class or object

How do I read from parameters.yml in a controller in symfony2?

The Clean Way - 2018+, Symfony 3.4+

Since 2017 and Symfony 3.3 + 3.4 there is much cleaner way - easy to setup and use.

Instead of using container and service/parameter locator anti-pattern, you can pass parameters to class via it's constructor. Don't worry, it's not time-demanding work, but rather setup once & forget approach.

How to set it up in 2 steps?

1. app/config/services.yml

# config.yml

# config.yml
parameters:
    api_pass: 'secret_password'
    api_user: 'my_name'

services:
    _defaults:
        autowire: true
        bind:
            $apiPass: '%api_pass%'
            $apiUser: '%api_user%'

    App\:
        resource: ..

2. Any Controller

<?php declare(strict_types=1);

final class ApiController extends SymfonyController
{
    /**
     * @var string 
     */
    private $apiPass;

    /**
     * @var string
     */
    private $apiUser;

    public function __construct(string $apiPass, string $apiUser)
    {
        $this->apiPass = $apiPass;
        $this->apiUser = $apiUser;
    }

    public function registerAction(): void
    {
        var_dump($this->apiPass); // "secret_password"
        var_dump($this->apiUser); // "my_name"
    }
}

Instant Upgrade Ready!

In case you use older approach, you can automate it with Rector.

Read More

This is called constructor injection over services locator approach.

To read more about this, check my post How to Get Parameter in Symfony Controller the Clean Way.

(It's tested and I keep it updated for new Symfony major version (5, 6...)).

Insert/Update Many to Many Entity Framework . How do I do it?

Try this one for Updating:

[HttpPost]
public ActionResult Edit(Models.MathClass mathClassModel)
{
    //get current entry from db (db is context)
    var item = db.Entry<Models.MathClass>(mathClassModel);

    //change item state to modified
    item.State = System.Data.Entity.EntityState.Modified;

    //load existing items for ManyToMany collection
    item.Collection(i => i.Students).Load();

    //clear Student items          
    mathClassModel.Students.Clear();

    //add Toner items
    foreach (var studentId in mathClassModel.SelectedStudents)
    {
        var student = db.Student.Find(int.Parse(studentId));
        mathClassModel.Students.Add(student);
    }                

    if (ModelState.IsValid)
    {
       db.SaveChanges();
       return RedirectToAction("Index");
    }

    return View(mathClassModel);
}

Can a Windows batch file determine its own file name?

Using the following script, based on SLaks answer, I determined that the correct answer is:

echo The name of this file is: %~n0%~x0
echo The name of this file is: %~nx0

And here is my test script:

@echo off
echo %0
echo %~0
echo %n0
echo %x0
echo %~n0
echo %dp0
echo %~dp0
pause

What I find interesting is that %nx0 won't work, given that we know the '~' char usually is used to strip/trim quotes off of a variable.

Google Maps: How to create a custom InfoWindow?

EDIT After some hunting around, this seems to be the best option:

https://github.com/googlemaps/js-info-bubble/blob/gh-pages/examples/example.html

You can see a customised version of this InfoBubble that I used on Dive Seven, a website for online scuba dive logging. It looks like this:


There are some more examples here. They definitely don't look as nice as the example in your screenshot, however.

Add space between cells (td) using css

table { 
  border-spacing: 10px; 
} 

This worked for me once I removed

border-collapse: separate;

from my table tag.

Replace multiple strings with multiple other strings

Just in case someone is wondering why the original poster's solution is not working:

var str = "I have a cat, a dog, and a goat.";

str = str.replace(/cat/gi, "dog");
// now str = "I have a dog, a dog, and a goat."

str = str.replace(/dog/gi, "goat");
// now str = "I have a goat, a goat, and a goat."

str = str.replace(/goat/gi, "cat");
// now str = "I have a cat, a cat, and a cat."

Only allow specific characters in textbox

You can probably use the KeyDown event, KeyPress event or KeyUp event. I would first try the KeyDown event I think.

You can set the Handled property of the event args to stop handling the event.

Flask Error: "Method Not Allowed The method is not allowed for the requested URL"

I also had similar problem where redirects were giving 404 or 405 randomly on my development server. It was an issue with gunicorn instances.

Turns out that I had not properly shut down the gunicorn instance before starting a new one for testing. Somehow both of the processes were running simultaneously, listening to the same port 8080 and interfering with each other. Strangely enough they continued running in background after I had killed all my terminals. Had to kill them manually using fuser -k 8080/tcp

Accessing items in an collections.OrderedDict by index

This community wiki attempts to collect existing answers.

Python 2.7

In python 2, the keys(), values(), and items() functions of OrderedDict return lists. Using values as an example, the simplest way is

d.values()[0]  # "python"
d.values()[1]  # "spam"

For large collections where you only care about a single index, you can avoid creating the full list using the generator versions, iterkeys, itervalues and iteritems:

import itertools
next(itertools.islice(d.itervalues(), 0, 1))  # "python"
next(itertools.islice(d.itervalues(), 1, 2))  # "spam"

The indexed.py package provides IndexedOrderedDict, which is designed for this use case and will be the fastest option.

from indexed import IndexedOrderedDict
d = IndexedOrderedDict({'foo':'python','bar':'spam'})
d.values()[0]  # "python"
d.values()[1]  # "spam"

Using itervalues can be considerably faster for large dictionaries with random access:

$ python2 -m timeit -s 'from collections import OrderedDict; from random import randint; size = 1000;   d = OrderedDict({i:i for i in range(size)})'  'i = randint(0, size-1); d.values()[i:i+1]'
1000 loops, best of 3: 259 usec per loop
$ python2 -m timeit -s 'from collections import OrderedDict; from random import randint; size = 10000;  d = OrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); d.values()[i:i+1]'
100 loops, best of 3: 2.3 msec per loop
$ python2 -m timeit -s 'from collections import OrderedDict; from random import randint; size = 100000; d = OrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); d.values()[i:i+1]'
10 loops, best of 3: 24.5 msec per loop

$ python2 -m timeit -s 'from collections import OrderedDict; from random import randint; size = 1000;   d = OrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); next(itertools.islice(d.itervalues(), i, i+1))'
10000 loops, best of 3: 118 usec per loop
$ python2 -m timeit -s 'from collections import OrderedDict; from random import randint; size = 10000;  d = OrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); next(itertools.islice(d.itervalues(), i, i+1))'
1000 loops, best of 3: 1.26 msec per loop
$ python2 -m timeit -s 'from collections import OrderedDict; from random import randint; size = 100000; d = OrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); next(itertools.islice(d.itervalues(), i, i+1))'
100 loops, best of 3: 10.9 msec per loop

$ python2 -m timeit -s 'from indexed import IndexedOrderedDict; from random import randint; size = 1000;   d = IndexedOrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); d.values()[i]'
100000 loops, best of 3: 2.19 usec per loop
$ python2 -m timeit -s 'from indexed import IndexedOrderedDict; from random import randint; size = 10000;  d = IndexedOrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); d.values()[i]'
100000 loops, best of 3: 2.24 usec per loop
$ python2 -m timeit -s 'from indexed import IndexedOrderedDict; from random import randint; size = 100000; d = IndexedOrderedDict({i:i for i in range(size)})' 'i = randint(0, size-1); d.values()[i]'
100000 loops, best of 3: 2.61 usec per loop

+--------+-----------+----------------+---------+
|  size  | list (ms) | generator (ms) | indexed |
+--------+-----------+----------------+---------+
|   1000 | .259      | .118           | .00219  |
|  10000 | 2.3       | 1.26           | .00224  |
| 100000 | 24.5      | 10.9           | .00261  |
+--------+-----------+----------------+---------+

Python 3.6

Python 3 has the same two basic options (list vs generator), but the dict methods return generators by default.

List method:

list(d.values())[0]  # "python"
list(d.values())[1]  # "spam"

Generator method:

import itertools
next(itertools.islice(d.values(), 0, 1))  # "python"
next(itertools.islice(d.values(), 1, 2))  # "spam"

Python 3 dictionaries are an order of magnitude faster than python 2 and have similar speedups for using generators.

+--------+-----------+----------------+---------+
|  size  | list (ms) | generator (ms) | indexed |
+--------+-----------+----------------+---------+
|   1000 | .0316     | .0165          | .00262  |
|  10000 | .288      | .166           | .00294  |
| 100000 | 3.53      | 1.48           | .00332  |
+--------+-----------+----------------+---------+

Pythonically add header to a csv file

You just add one additional row before you execute the loop. This row contains your CSV file header name.

schema = ['a','b','c','b']
row = 4
generators = ['A','B','C','D']
with open('test.csv','wb') as csvfile:    
     writer = csv.writer(csvfile, delimiter=delimiter)
# Gives the header name row into csv
     writer.writerow([g for g in schema])   
#Data add in csv file       
     for x in xrange(rows):
         writer.writerow([g() for g in generators])

matplotlib get ylim values

I put above-mentioned methods together using ax instead of plt

import numpy as np
import matplotlib.pyplot as plt

x = range(100)
y = x

fig, ax = plt.subplots(1, 1, figsize=(7.2, 7.2))
ax.plot(x, y);

# method 1
print(ax.get_xlim())
print(ax.get_xlim())
# method 2
print(ax.axis())

enter image description here

Prevent the keyboard from displaying on activity start

Function to hide the keyboard.

public static void hideKeyboard(Activity activity) {
    View view = activity.getCurrentFocus();

    if (view != null) {
        InputMethodManager inputManager = (InputMethodManager) activity.getSystemService(Context.INPUT_METHOD_SERVICE);

        inputManager.hideSoftInputFromWindow(view.getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
    }
}

Hide keyboard in AndroidManifext.xml file.

<activity
    android:name=".MainActivity"
    android:label="@string/app_name"
    android:theme="@style/AppTheme"
    android:windowSoftInputMode="stateHidden">

Phone Number Validation MVC

[DataType(DataType.PhoneNumber)] does not come with any validation logic out of the box.

According to the docs:

When you apply the DataTypeAttribute attribute to a data field you must do the following:

  • Issue validation errors as appropriate.

The [Phone] Attribute inherits from [DataType] and was introduced in .NET Framework 4.5+ and is in .NET Core which does provide it's own flavor of validation logic. So you can use like this:

[Phone()]
public string PhoneNumber { get; set; }

However, the out-of-the-box validation for Phone numbers is pretty permissive, so you might find yourself wanting to inherit from DataType and implement your own IsValid method or, as others have suggested here, use a regular expression & RegexValidator to constrain input.

Note: Use caution with Regex against unconstrained input per the best practices as .NET has made the pivot away from regular expressions in their own internal validation logic for phone numbers

How do I interpret precision and scale of a number in a database?

Numeric precision refers to the maximum number of digits that are present in the number.

ie 1234567.89 has a precision of 9

Numeric scale refers to the maximum number of decimal places

ie 123456.789 has a scale of 3

Thus the maximum allowed value for decimal(5,2) is 999.99

Generate full SQL script from EF 5 Code First Migrations

For anyone using entity framework core ending up here. This is how you do it.

# Powershell / Package manager console
Script-Migration

# Cli 
dotnet ef migrations script

You can use the -From and -To parameter to generate an update script to update a database to a specific version.

Script-Migration -From 20190101011200_Initial-Migration -To 20190101021200_Migration-2

https://docs.microsoft.com/en-us/ef/core/managing-schemas/migrations/#generate-sql-scripts

There are several options to this command.

The from migration should be the last migration applied to the database before running the script. If no migrations have been applied, specify 0 (this is the default).

The to migration is the last migration that will be applied to the database after running the script. This defaults to the last migration in your project.

An idempotent script can optionally be generated. This script only applies migrations if they haven't already been applied to the database. This is useful if you don't exactly know what the last migration applied to the database was or if you are deploying to multiple databases that may each be at a different migration.

Make file echo displaying "$PATH" string

In the manual for GNU make, they talk about this specific example when describing the value function:

The value function provides a way for you to use the value of a variable without having it expanded. Please note that this does not undo expansions which have already occurred; for example if you create a simply expanded variable its value is expanded during the definition; in that case the value function will return the same result as using the variable directly.

The syntax of the value function is:

 $(value variable)

Note that variable is the name of a variable; not a reference to that variable. Therefore you would not normally use a ‘$’ or parentheses when writing it. (You can, however, use a variable reference in the name if you want the name not to be a constant.)

The result of this function is a string containing the value of variable, without any expansion occurring. For example, in this makefile:

 FOO = $PATH

 all:
         @echo $(FOO)
         @echo $(value FOO)

The first output line would be ATH, since the “$P” would be expanded as a make variable, while the second output line would be the current value of your $PATH environment variable, since the value function avoided the expansion.

SQL Server datetime LIKE select?

Try this

SELECT top 10 * from record WHERE  IsActive = 1 and CONVERT(VARCHAR, register_date, 120) LIKE '2020-01%'

Disable browsers vertical and horizontal scrollbars

(I can't comment yet, but wanted to share this):

Lyncee's code worked for me in desktop browser. However, on iPad (Chrome, iOS 9), it crashed the application. To fix it, I changed

document.documentElement.style.overflow = ...

to

document.body.style.overflow = ...

which solved my problem.

PHP Fatal error when trying to access phpmyadmin mb_detect_encoding

Try to install mysqli and pdo. Put it in terminal:

./configure --with-mysql=/usr/bin/mysql_config  \
--with-mysqli=mysqlnd \
--with-pdo-mysql=mysqlnd

How can I change the Java Runtime Version on Windows (7)?

Go to control panel --> Java You can select the active version here

how do you pass images (bitmaps) between android activities using bundles?

I would highly recommend a different approach.

It's possible if you REALLY want to do it, but it costs a lot of memory and is also slow. It might not work if you have an older phone and a big bitmap. You could just pass it as an extra, for example intent.putExtra("data", bitmap). A Bitmap implements Parcelable, so you can put it in an extra. Likewise, a bundle has putParcelable.

If you want to pass it inbetween activities, I would store it in a file. That's more efficient, and less work for you. You can create private files in your data folder using MODE_PRIVATE that are not accessible to any other app.

No tests found with test runner 'JUnit 4'

Very late but what solved the problem for me was that my test method names all started with captial letters: "public void Test". Making the t lower case worked.

How to get Locale from its String representation in Java?

Method that returns locale from string exists in commons-lang library: LocaleUtils.toLocale(localeAsString)

Difference between two dates in Python

Try this:

data=pd.read_csv('C:\Users\Desktop\Data Exploration.csv')
data.head(5)
first=data['1st Gift']
last=data['Last Gift']
maxi=data['Largest Gift']
l_1=np.mean(first)-3*np.std(first)
u_1=np.mean(first)+3*np.std(first)


m=np.abs(data['1st Gift']-np.mean(data['1st Gift']))>3*np.std(data['1st Gift'])
pd.value_counts(m)
l=first[m]
data.loc[:,'1st Gift'][m==True]=np.mean(data['1st Gift'])+3*np.std(data['1st Gift'])
data['1st Gift'].head()




m=np.abs(data['Last Gift']-np.mean(data['Last Gift']))>3*np.std(data['Last Gift'])
pd.value_counts(m)
l=last[m]
data.loc[:,'Last Gift'][m==True]=np.mean(data['Last Gift'])+3*np.std(data['Last Gift'])
data['Last Gift'].head()

How do you create a static class in C++?

In C++ you want to create a static function of a class (not a static class).

class BitParser {
public:
  ...
  static ... getBitAt(...) {
  }
};

You should then be able to call the function using BitParser::getBitAt() without instantiating an object which I presume is the desired result.

No 'Access-Control-Allow-Origin' header is present on the requested resource- AngularJS

I have a solution below and its works for me:

app.controller('LoginController', ['$http', '$scope', function ($scope, $http) {
$scope.login = function (credentials) {
$http({
        method: 'jsonp',
        url: 'http://mywebservice',
        params: {
            format: 'jsonp',
            callback: 'JSON_CALLBACK'
        }
    }).then(function (response) {
        alert(response.data);
    });
  }
}]);

in 'http://mywebservice' there must be need a callback parameter which return JSON_CALLBACK with data.
There is a sample example below which works perfect

$scope.url = "https://angularjs.org/greet.php";
    $http({
        method: 'jsonp',
        url: $scope.url,
        params: {
            format: 'jsonp',
            name: 'Super Hero',
            callback: 'JSON_CALLBACK'
        }
    }).then(function (response) {
        alert(response.data);
    });

example output:

{"name":"Super Hero","salutation":"Apa khabar","greeting":"Apa khabar Super Hero!"}

How to check if running as root in a bash script

try the following code:

if [ "$(id -u)" != "0" ]; then
    echo "Sorry, you are not root."
    exit 1
fi

OR

if [ `id -u` != "0" ]; then
    echo "Sorry, you are not root."
    exit 1
fi

Inverse of a matrix using numpy

Inverse of a matrix using python and numpy:

>>> import numpy as np
>>> b = np.array([[2,3],[4,5]])
>>> np.linalg.inv(b)
array([[-2.5,  1.5],
       [ 2. , -1. ]])

Not all matrices can be inverted. For example singular matrices are not Invertable:

>>> import numpy as np
>>> b = np.array([[2,3],[4,6]])
>>> np.linalg.inv(b)

LinAlgError: Singular matrix

Solution to singular matrix problem:

try-catch the Singular Matrix exception and keep going until you find a transform that meets your prior criteria AND is also invertable.

Intuition for why matrix inversion can't always be done; like in singular matrices:

Imagine an old overhead film projector that shines a bright light through film onto a white wall. The pixels in the film are projected to the pixels on the wall.

If I stop the film projection on a single frame, you will see the pixels of the film on the wall and I ask you to regenerate the film based on what you see. That's easy, you say, just take the inverse of the matrix that performed the projection. An Inverse of a matrix is the reversal of the projection.

Now imagine if the projector was corrupted, and I put a distorted lens in front of the film. Now multiple pixels are projected to the same spot on the wall. I asked you again to "undo this operation with the matrix inverse". You say: "I can't because you destroyed information with the lens distortion, I can't get back to where we were, because the matrix is either Singular or Degenerate."

A matrix that can be used to transform some data into other data is invertable only if the process can be reversed with no loss of information. If your matrix can't be inverted, perhaps you are defining your projection using a guess-and-check methodology rather than using a process that guarantees a non-corrupting transform.

If you're using a heuristic or anything less than perfect mathematical precision, then you'll have to define another process to manage and quarantine distortions so that programming by Brownian motion can resume.

Source:

http://docs.scipy.org/doc/numpy/reference/generated/numpy.linalg.inv.html#numpy.linalg.inv

How to do a regular expression replace in MySQL?

We can use IF condition in SELECT query as below:

Suppose that for anything with "ABC","ABC1","ABC2","ABC3",..., we want to replace with "ABC" then using REGEXP and IF() condition in the SELECT query, we can achieve this.

Syntax:

SELECT IF(column_name REGEXP 'ABC[0-9]$','ABC',column_name)
FROM table1 
WHERE column_name LIKE 'ABC%';

Example:

SELECT IF('ABC1' REGEXP 'ABC[0-9]$','ABC','ABC1');

Android Activity as a dialog

If your activity is being rendered as a dialog, simply add a button to your activity's xml,

<Button
    android:id="@+id/close_button"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Dismiss" />

Then attach a click listener in your Activity's Java code. In the listener, simply call finish()

Button close_button = (Button) findViewById(R.id.close_button);
close_button.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View v) {
        finish();
    }
});

That should dismiss your dialog, returning you to the calling activity.

How to delete history of last 10 commands in shell?

Combining answers from above:

history -w vi ~/.bash_history history -r

How to print a stack trace in Node.js?

In case someone is still looking for this like I was, then there is a module we can use called "stack-trace". It is really popular. NPM Link

Then walk through the trace.

  var stackTrace = require('stack-trace');
  .
  .
  .
  var trace = stackTrace.get();
  trace.map(function (item){ 
    console.log(new Date().toUTCString() + ' : ' +  item.toString() );  
  });

Or just simply print the trace:

var stackTrace = require('stack-trace');
.
.
.
var trace = stackTrace.get();
trace.toString();

Where is Ubuntu storing installed programs?

Just for an addition reference to the above answers. I can not use dpkg -L to find the correct path for cuda. See the results I got from dpkg -L

$ dpkg -L cuda
/.
/usr
/usr/share
/usr/share/doc
/usr/share/doc/cuda
/usr/share/doc/cuda/copyright
/usr/share/doc/cuda/changelog.Debian.gz

the correct path is /usr/local/cuda

$ ll /usr/local | grep cuda

lrwxrwxrwx  1 root root    8 Oct 20 18:45 cuda -> cuda-9.0/

drwxr-xr-x 15 root root 4096 Oct 20 18:44 cuda-9.0/

Btw, I did install cuda by the command of

dpkg -i xx_cuda_xxx.deb

MySQL command line client for Windows

download the mysql-5.0.23-win32.zip (this is the smallest possible one) from archived versions in mysql.com website

cut and paste the installation in c drive as mysql folder

then install then follow instructions as per this page: https://cyleft.wordpress.com/2008/07/20/fixing-mysql-service-could-not-start-1067-errors/

PhpMyAdmin not working on localhost

STOP ALL SERVICES OF XAMPP Edit Apache(httpd.conf) file 1)"Listen 80" if its already 80 and not working then replace it by 81 2) "ServerName localhost:80" if its already 80 and not working then replace it by 81 SAVE EXIT RESTART [WINDOWS USER run as administrator]

react-native :app:installDebug FAILED

Previously, I had installed npm and then installed yarn, and that is when I started to have problems compiling, even when creating new projects with react-native init . Uninstalling yarn, I was able to create and compile.

Bootstrap 3 and Youtube in Modal

I have solved it on wordpress template:

$videoLink ="http://www.youtube.com/watch?v=yRuVYkA8i1o;".   
<?php
    parse_str( parse_url( $videoLink, PHP_URL_QUERY ), $my_array_of_vars );
    $youtube_ID = $my_array_of_vars['v'];    
?> 
<a class="video" data-toggle="modal" data-target="#myModal" rel="<?php echo $youtube_ID;?>">
    <img src="<?php bloginfo('template_url');?>/assets/img/play.png" />
</a>

<div class="modal fade video-lightbox" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">    
    <div class="modal-dialog">
        <div class="modal-content">
            <div class="modal-header">
                <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
            </div>
            <div class="modal-body"></div>
        </div><!-- /.modal-content -->
    </div><!-- /.modal-dialog -->
</div><!-- /.modal -->

<script> 
    jQuery(document).ready(function ($) {
        var $midlayer = $('.modal-body');     
        $('#myModal').on('show.bs.modal', function (e) {
            var $video = $('a.video');
            var vid = $video.attr('rel');
            var iframe = '<iframe />';  
            var url = "//youtube.com/embed/"+vid+"?autoplay=1&autohide=1&modestbranding=1&rel=0&hd=1";
            var width_f = '100%';
            var height_f = 400;
            var frameborder = 0;
            jQuery(iframe, {
                name: 'videoframe',
                id: 'videoframe',
                src: url,
                width:  width_f,
                height: height_f,
                frameborder: 0,
                class: 'youtube-player',
                type: 'text/html',
                allowfullscreen: true
            }).appendTo($midlayer);   
        });

        $('#myModal').on('hide.bs.modal', function (e) {
            $('div.modal-body').html('');
        }); 
    });
</script>

Apply multiple functions to multiple groupby columns

Pandas >= 0.25.0, named aggregations

Since pandas version 0.25.0 or higher, we are moving away from the dictionary based aggregation and renaming, and moving towards named aggregations which accepts a tuple. Now we can simultaneously aggregate + rename to a more informative column name:

Example:

df = pd.DataFrame(np.random.rand(4,4), columns=list('abcd'))
df['group'] = [0, 0, 1, 1]

          a         b         c         d  group
0  0.521279  0.914988  0.054057  0.125668      0
1  0.426058  0.828890  0.784093  0.446211      0
2  0.363136  0.843751  0.184967  0.467351      1
3  0.241012  0.470053  0.358018  0.525032      1

Apply GroupBy.agg with named aggregation:

df.groupby('group').agg(
             a_sum=('a', 'sum'),
             a_mean=('a', 'mean'),
             b_mean=('b', 'mean'),
             c_sum=('c', 'sum'),
             d_range=('d', lambda x: x.max() - x.min())
)

          a_sum    a_mean    b_mean     c_sum   d_range
group                                                  
0      0.947337  0.473668  0.871939  0.838150  0.320543
1      0.604149  0.302074  0.656902  0.542985  0.057681

performing HTTP requests with cURL (using PROXY)

From man curl:

-x, --proxy <[protocol://][user:password@]proxyhost[:port]>

     Use the specified HTTP proxy. 
     If the port number is not specified, it is assumed at port 1080.

General way:

export http_proxy=http://your.proxy.server:port/

Then you can connect through proxy from (many) application.

And, as per comment below, for https:

export https_proxy=https://your.proxy.server:port/

Converting a vector<int> to string

Maybe std::ostream_iterator and std::ostringstream:

#include <vector>
#include <string>
#include <algorithm>
#include <sstream>
#include <iterator>
#include <iostream>

int main()
{
  std::vector<int> vec;
  vec.push_back(1);
  vec.push_back(4);
  vec.push_back(7);
  vec.push_back(4);
  vec.push_back(9);
  vec.push_back(7);

  std::ostringstream oss;

  if (!vec.empty())
  {
    // Convert all but the last element to avoid a trailing ","
    std::copy(vec.begin(), vec.end()-1,
        std::ostream_iterator<int>(oss, ","));

    // Now add the last element with no delimiter
    oss << vec.back();
  }

  std::cout << oss.str() << std::endl;
}

Escape double quote character in XML

In C++ you can use EscapeXML ATL API. This is the correct way of handling special chars ...

How do I hide certain files from the sidebar in Visual Studio Code?

You can configure patterns to hide files and folders from the explorer and searches.

  1. Open VS User Settings (Main menu: File > Preferences > Settings). This will open the setting screen.
  2. Search for files:exclude in the search at the top.
  3. Configure the User Setting with new glob patterns as needed. In this case add this pattern node_modules/ then click OK. The pattern syntax is powerful. You can find pattern matching details under the Search Across Files topic.

When you are done it should look something like this: enter image description here

If you want to directly edit the settings file: For example to hide a top level node_modules folder in your workspace:

"files.exclude": {
    "node_modules/": true
}

To hide all files that start with ._ such as ._.DS_Store files found on OSX:

"files.exclude": {
    "**/._*": true
}

You also have the ability to change Workspace Settings (Main menu: File > Preferences > Workspace Settings). Workspace settings will create a .vscode/settings.json file in your current workspace and will only be applied to that workspace. User Settings will be applied globally to any instance of VS Code you open, but they won't override Workspace Settings if present. Read more on customizing User and Workspace Settings.

Foreign key referring to primary keys across multiple tables?

Technically possible. You would probably reference employees_ce in deductions and employees_sn. But why don't you merge employees_sn and employees_ce? I see no reason why you have two table. No one to many relationship. And (not in this example) many columns.

If you do two references for one column, an employee must have an entry in both tables.

Adding placeholder attribute using Jquery

You just need this:

$(".hidden").attr("placeholder", "Type here to search");

classList is used for manipulating classes and not attributes.

How to get the first line of a file in a bash script?

to read first line using bash, use read statement. eg

read -r firstline<file

firstline will be your variable (No need to assign to another)

Remove non-utf8 characters from string

From recent patch to Drupal's Feeds JSON parser module:

//remove everything except valid letters (from any language)
$raw = preg_replace('/(?:\\\\u[\pL\p{Zs}])+/', '', $raw);

If you're concerned yes it retains spaces as valid characters.

Did what I needed. It removes widespread nowadays emoji-characters that don't fit into MySQL's 'utf8' character set and that gave me errors like "SQLSTATE[HY000]: General error: 1366 Incorrect string value".

For details see https://www.drupal.org/node/1824506#comment-6881382

What does on_delete do on Django models?

Here is answer for your question that says: why we use on_delete?

When an object referenced by a ForeignKey is deleted, Django by default emulates the behavior of the SQL constraint ON DELETE CASCADE and also deletes the object containing the ForeignKey. This behavior can be overridden by specifying the on_delete argument. For example, if you have a nullable ForeignKey and you want it to be set null when the referenced object is deleted:

user = models.ForeignKey(User, blank=True, null=True, on_delete=models.SET_NULL)

The possible values for on_delete are found in django.db.models:

CASCADE: Cascade deletes; the default.

PROTECT: Prevent deletion of the referenced object by raising ProtectedError, a subclass of django.db.IntegrityError.

SET_NULL: Set the ForeignKey null; this is only possible if null is True.

SET_DEFAULT: Set the ForeignKey to its default value; a default for the ForeignKey must be set.

Convert string to variable name in JavaScript

The window['variableName'] method ONLY works if the variable is defined in the global scope. The correct answer is "Refactor". If you can provide an "Object" context then a possible general solution exists, but there are some variables which no global function could resolve based on the scope of the variable.

(function(){
    var findMe = 'no way';
})();

Killing a process using Java

If you start the process from with in your Java application (ex. by calling Runtime.exec() or ProcessBuilder.start()) then you have a valid Process reference to it, and you can invoke the destroy() method in Process class to kill that particular process.

But be aware that if the process that you invoke creates new sub-processes, those may not be terminated (see http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4770092).

On the other hand, if you want to kill external processes (which you did not spawn from your Java app), then one thing you can do is to call O/S utilities which allow you to do that. For example, you can try a Runtime.exec() on kill command under Unix / Linux and check for return values to ensure that the application was killed or not (0 means success, -1 means error). But that of course will make your application platform dependent.

force Maven to copy dependencies into target/lib

You can use the the Shade Plugin to create an uber jar in which you can bundle all your 3rd party dependencies.

No server in Eclipse; trying to install Tomcat

You can install Tomcat server form Eclipse market place.

Help -> Eclipse Market Place search for 'Tomcat' -> Install Eclipse Tomcat plugin.

enter image description here

After installation restart eclipse.

Allow user to select camera or gallery for image

You'll have to create your own chooser dialog merging both intent resolution results.

To do this, you will need to query the PackageManager with PackageManager.queryIntentActivities() for both original intents and create the final list of possible Intents with one new Intent for each retrieved activity like this:

List<Intent> yourIntentsList = new ArrayList<Intent>();

List<ResolveInfo> listCam = packageManager.queryIntentActivities(camIntent, 0);
for (ResolveInfo res : listCam) {
    final Intent finalIntent = new Intent(camIntent);
    finalIntent.setComponent(new ComponentName(res.activityInfo.packageName, res.activityInfo.name));
    yourIntentsList.add(finalIntent);
}

List<ResolveInfo> listGall = packageManager.queryIntentActivities(gallIntent, 0);
for (ResolveInfo res : listGall) {
    final Intent finalIntent = new Intent(gallIntent);
    finalIntent.setComponent(new ComponentName(res.activityInfo.packageName, res.activityInfo.name));
    yourIntentsList.add(finalIntent);
}

(I wrote this directly here so this may not compile)

Then, for more info on creating a custom dialog from a list see https://developer.android.com/guide/topics/ui/dialogs.html#AlertDialog

How to create a release signed apk file using Gradle?

Extending the answer by David Vavra,create a file ~/.gradle/gradle.properties and add

RELEASE_STORE_FILE=/path/to/.keystore
RELEASE_KEY_ALIAS=XXXXX
RELEASE_STORE_PASSWORD=XXXXXXXXX
RELEASE_KEY_PASSWORD=XXXXXXXXX

Then in build.gradle

  signingConfigs {
    release {
    }
  }

  buildTypes {
    release {
      minifyEnabled true
      shrinkResources true

    }
  }

  // make this optional
  if ( project.hasProperty("RELEASE_KEY_ALIAS") ) {
    signingConfigs {
      release {
        storeFile file(RELEASE_STORE_FILE)
        storePassword RELEASE_STORE_PASSWORD
        keyAlias RELEASE_KEY_ALIAS
        keyPassword RELEASE_KEY_PASSWORD
      }
    }
    buildTypes {
      release {
        signingConfig signingConfigs.release
      }
    }
  }

Twitter - share button, but with image

I used this code to solve this problem.

<a href="https://twitter.com/intent/tweet?url=myUrl&text=myTitle" target="_blank"><img src="path_to_my_image"/></a>

You can check the tweet-button documentation here tweet-button

Unknown column in 'field list' error on MySQL Update query

Try using different quotes for "y" as the identifier quote character is the backtick (“`”). Otherwise MySQL "thinks" that you point to a column named "y".

See also MySQL 5 Documentation

Angularjs - simple form submit

_x000D_
_x000D_
var app = angular.module( "myApp", [] );_x000D_
_x000D_
app.controller( "myCtrl", ["$scope", function($scope) {_x000D_
_x000D_
    $scope.submit_form = function(formData) {_x000D_
_x000D_
        $scope.formData = formData;_x000D_
_x000D_
        console.log(formData); // object_x000D_
        console.log(JSON.stringify(formData)); // string_x000D_
_x000D_
        $scope.form = {}; // clear ng-model form_x000D_
_x000D_
    }_x000D_
_x000D_
}] );
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.4/angular.min.js"></script>_x000D_
_x000D_
<div ng-app="myApp" ng-controller="myCtrl">_x000D_
_x000D_
    <form ng-submit="submit_form(form)" >_x000D_
_x000D_
        Firstname: <input type="text" ng-model="form.firstname" /><br />_x000D_
        Lastname: <input type="text" ng-model="form.lastname" /><br />_x000D_
_x000D_
        <hr />_x000D_
_x000D_
        <input type="submit" value="Submit" />_x000D_
_x000D_
    </form>_x000D_
_x000D_
    <hr />          _x000D_
_x000D_
    <p>Firstname: {{ form.firstname }}</p>_x000D_
    <p>Lastname: {{ form.lastname }}</p>_x000D_
_x000D_
    <pre>Submit Form: {{ formData }} </pre>_x000D_
_x000D_
</div>
_x000D_
_x000D_
_x000D_

Codepen

How to submit a form with JavaScript by clicking a link?

If you use jQuery and would need an inline solution, this would work very well;

<a href="#" onclick="$(this).closest('form').submit();">submit form</a>

Also, you might want to replace

<a href="#">text</a>

with

<a href="javascript:void(0);">text</a>

so the user does not scroll to the top of your page when clicking the link.

Sending the bearer token with axios

By using Axios interceptor:

const service = axios.create({
  timeout: 20000 // request timeout
});

// request interceptor

service.interceptors.request.use(
  config => {
    // Do something before request is sent

    config.headers["Authorization"] = "bearer " + getToken();
    return config;
  },
  error => {
    Promise.reject(error);
  }
);

Django - taking values from POST request

Read about request objects that your views receive: https://docs.djangoproject.com/en/dev/ref/request-response/#httprequest-objects

Also your hidden field needs a reliable name and then a value:

<input type="hidden" name="title" value="{{ source.title }}">

Then in a view:

request.POST.get("title", "")

How to do a simple file search in cmd

dir /s *foo* searches in current folder and sub folders.

It finds directories as well as files.

where /s means(documentation):

/s Lists every occurrence of the specified file name within the specified directory and all subdirectories.

Getting the Username from the HKEY_USERS values

You can use the command PSGetSid from Microsoft's SysInternals team.

Download URL: http://technet.microsoft.com/en-gb/sysinternals/bb897417.aspx

Usage:

psgetsid [\\computer[,computer[,...] | @file] [-u username [-p password]]] [account|SID]
-u  Specifies optional user name for login to remote computer.
-p  Specifies optional password for user name. If you omit this you will be prompted to enter a hidden password.
Account PsGetSid will report the SID for the specified user account rather than the computer.
SID PsGetSid will report the account for the specified SID.
Computer    Direct PsGetSid to perform the command on the remote computer or computers specified. If you omit the computer name PsGetSid runs the command on the local system, and if you specify a wildcard (\\*), PsGetSid runs the command on all computers in the current domain.
@file   PsGetSid will execute the command on each of the computers listed in the file.

Example:

psgetsid S-1-5-21-583907252-682003330-839522115-63941

NB:

  • Where the user is a domain/AD(LDAP) user, running this on any computer on the domain should give the same results.
  • Where the user is local to the machine the command should either be run on that machine, or you should specify the computer via the optional parameter.

Update

If you use PowerShell, the following may be useful for resolving any AD users listed:

#create a drive for HKEY USERS:
New-PSDrive -PSProvider Registry -Name HKU -Root HKEY_USERS -ErrorAction SilentlyContinue

#List all immediate subfolders
#where they're a folder (not a key)
#and they's an SID (i.e. exclude .DEFAULT and SID_Classes entries)
#return the SID
#and return the related AD entry (should one exist).
Get-ChildItem -Path 'HKU:\' `
| ?{($_.PSIsContainer -eq $true) `
-and ($_.PSChildName -match '^S-[\d-]+$')} `
| select @{N='SID';E={$_.PSChildName}} `
, @{N='Name';E={Get-ADUser $_.PSChildName | select -expand Name}}

You could also refine the SID filter further to only pull back those SIDs which will resolve to an AD account if you wished; more on the SID structure here: https://technet.microsoft.com/en-us/library/cc962011.aspx

How can I get the height of an element using css only

You could use the CSS calc parameter to calculate the height dynamically like so:

_x000D_
_x000D_
.dynamic-height {_x000D_
   color: #000;_x000D_
   font-size: 12px;_x000D_
   margin-top: calc(100% - 10px);_x000D_
   text-align: left;_x000D_
}
_x000D_
<div class='dynamic-height'>_x000D_
    <p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem.</p>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Spring - No EntityManager with actual transaction available for current thread - cannot reliably process 'persist' call

If you have

@Transactional // Spring Transactional
class MyDao extends Dao {
}

and super-class

class Dao {
    public void save(Entity entity) { getEntityManager().merge(entity); }
}

and you call

@Autowired MyDao myDao;
myDao.save(entity);

you won't get a Spring TransactionInterceptor (that gives you a transaction).

This is what you need to do:

@Transactional 
class MyDao extends Dao {
    public void save(Entity entity) { super.save(entity); }
}

Unbelievable but true.

How to delete all records from table in sqlite with Android?

try this code to delete all data from a table..

String selectQuery = "DELETE FROM table_name ";
Cursor cursor = data1.getReadableDatabase().rawQuery(selectQuery, null);

Tools for creating Class Diagrams

I used Poseidon UML Community Edition, it's platform independent and makes fine and clean diagrams. There are some screenshots here.

Reset all the items in a form

Quick answer, maybe it'll help:

private void button1_Click(object sender, EventArgs e)
{            
    Form2 f2 = new Form2();
    f2.ShowDialog();
    while (f2.DialogResult == DialogResult.Retry)
    {
        f2 = new Form2();
        f2.ShowDialog();
    }
}

and in Form2 (The 'settings' Form):

private void button1_Click(object sender, EventArgs e)
{
    DialogResult = DialogResult.OK;
    Close();
}

private void button2_Click(object sender, EventArgs e)
{
    DialogResult = DialogResult.Retry;
    Close();
}

How to create a popup window (PopupWindow) in Android

Edit your style.xml with:

<style name="AppTheme" parent="Base.V21.Theme.AppCompat.Light.Dialog">

Base.V21.Theme.AppCompat.Light.Dialog provides a android poup-up theme

xcopy file, rename, suppress "Does xxx specify a file name..." message

Use copy instead of xcopy when copying files.

e.g. copy "bin\development\whee.config.example" "TestConnectionExternal\bin\Debug\whee.config"

Delete all duplicate rows Excel vba

There's a RemoveDuplicates method that you could use:

Sub DeleteRows()

    With ActiveSheet
        Set Rng = Range("A1", Range("B1").End(xlDown))
        Rng.RemoveDuplicates Columns:=Array(1, 2), Header:=xlYes
    End With

End Sub

Codeigniter how to create PDF

I have used mpdf in my project. In Codeigniter-3, putted mpdf files under application/third_party and then used in this way:

 /**
 * This function is used to display data in PDF file.
 * function is using mpdf api to generate pdf.
 * @param number $id : This is unique id of table.
 */
function generatePDF($id){
    require APPPATH . '/third_party/mpdf/vendor/autoload.php';
    //$mpdf=new mPDF();
    $mpdf = new mPDF('utf-8', 'Letter', 0, '', 0, 0, 7, 0, 0, 0);

    $checkRecords =  $this->user_model->getCheckInfo($id);      
    foreach ($checkRecords as $key => $value) {
        $data['info'] = $value;
        $filename = $this->load->view(CHEQUE_VIEWS.'index',$data,TRUE);
        $mpdf->WriteHTML($filename); 
    }

    $mpdf->Output(); //output pdf document.
    //$content = $mpdf->Output('', 'S'); //get pdf document content's as variable. 

}

check if a number already exist in a list in python

If you want to have unique elements in your list, then why not use a set, if of course, order does not matter for you: -

>>> s = set()
>>> s.add(2)
>>> s.add(4)
>>> s.add(5)
>>> s.add(2)
>>> s
39: set([2, 4, 5])

If order is a matter of concern, then you can use: -

>>> def addUnique(l, num):
...     if num not in l:
...         l.append(num)
...     
...     return l

You can also find an OrderedSet recipe, which is referred to in Python Documentation

how to get the child node in div using javascript

var tds = document.getElementById("ctl00_ContentPlaceHolder1_Jobs_dlItems_ctl01_a").getElementsByTagName("td");
time = tds[0].firstChild.value;
address = tds[3].firstChild.value;

Using reflection in Java to create a new instance with the reference variable type set to the new instance class name?

If you knew the Class of ImplementationType you could create an instance of it. So what you are trying to do is not possible.

HTML colspan in CSS

You could always position:absolute; things and specify widths. It's not a very fluid way of doing it, but it would work.

How do you get the width and height of a multi-dimensional array?

You could also consider using getting the indexes of last elements in each specified dimensions using this as following;

int x = ary.GetUpperBound(0);
int y = ary.GetUpperBound(1);

Keep in mind that this gets the value of index as 0-based.

How can I time a code segment for testing performance with Pythons timeit?

I see the question has already been answered, but still want to add my 2 cents for the same.

I have also faced similar scenario in which I have to test the execution times for several approaches and hence written a small script, which calls timeit on all functions written in it.

The script is also available as github gist here.

Hope it will help you and others.

from random import random
import types

def list_without_comprehension():
    l = []
    for i in xrange(1000):
        l.append(int(random()*100 % 100))
    return l

def list_with_comprehension():
    # 1K random numbers between 0 to 100
    l = [int(random()*100 % 100) for _ in xrange(1000)]
    return l


# operations on list_without_comprehension
def sort_list_without_comprehension():
    list_without_comprehension().sort()

def reverse_sort_list_without_comprehension():
    list_without_comprehension().sort(reverse=True)

def sorted_list_without_comprehension():
    sorted(list_without_comprehension())


# operations on list_with_comprehension
def sort_list_with_comprehension():
    list_with_comprehension().sort()

def reverse_sort_list_with_comprehension():
    list_with_comprehension().sort(reverse=True)

def sorted_list_with_comprehension():
    sorted(list_with_comprehension())


def main():
    objs = globals()
    funcs = []
    f = open("timeit_demo.sh", "w+")

    for objname in objs:
        if objname != 'main' and type(objs[objname]) == types.FunctionType:
            funcs.append(objname)
    funcs.sort()
    for func in funcs:
        f.write('''echo "Timing: %(funcname)s"
python -m timeit "import timeit_demo; timeit_demo.%(funcname)s();"\n\n
echo "------------------------------------------------------------"
''' % dict(
                funcname = func,
                )
            )

    f.close()

if __name__ == "__main__":
    main()

    from os import system

    #Works only for *nix platforms
    system("/bin/bash timeit_demo.sh")

    #un-comment below for windows
    #system("cmd timeit_demo.sh")

How to write macro for Notepad++?

This post can help you as a little bit related :

Using RegEX To Prefix And Append In Notepad++

Assuming alphanumeric words, you can use:

Search = ^([A-Za-z0-9]+)$ Replace = able:"\1"

Or, if you just want to highlight the lines and use "Replace All" & "In Selection" (with the same replace):

Search = ^(.+)$

^ points to the start of the line. $ points to the end of the line.

\1 will be the source match within the parentheses.

Tool to compare directories (Windows 7)

I use WinMerge. It is free and works pretty well (works for files and directories).

SQL Query for Student mark functionality

I like the simple solution using windows functions:

select t.*
from (select student.*, su.subname, max(mark) over (partition by subid) as maxmark
      from marks m join
           students st
           on m.stid = st.stid join
           subject su
           on m.subid = su.subid
     ) t
where t.mark = maxmark

Or, alternatively:

select t.*
from (select student.*, su.subname, rank(mark) over (partition by subid order by mark desc) as markseqnum
      from marks m join
           students st
           on m.stid = st.stid join
           subject su
           on m.subid = su.subid
     ) t
where markseqnum = 1

Jenkins pipeline how to change to another folder

Use WORKSPACE environment variable to change workspace directory.

If doing using Jenkinsfile, use following code :

dir("${env.WORKSPACE}/aQA"){
    sh "pwd"
}

Get Substring - everything before certain char

Things have moved on a bit since this thread started.

Now, you could use

string.Concat(s.TakeWhile((c) => c != '-'));

How do you install Google frameworks (Play, Accounts, etc.) on a Genymotion virtual device?

EDIT 2

After three months we can say: no more official Google Apps in Genymotion and CyanogenMod-like method is only way to get Google Apps. However, you can still use the previous project of the Genymotion team: AndroVM (download mirror).


EDIT

Google apps will be removed from Genymotion in November. You can find more information on the Genymotion Google Plus page.


Choose virtual device with Google Apps:

Done:

How to add row in JTable?

Use

    DefaultTableModel model = (DefaultTableModel) MyJTable.getModel();

    Vector row = new Vector();
    row.add("Enter data to column 1");
    row.add("Enter data to column 2");
    row.add("Enter data to column 3");
    model.addRow(row);

get the model with DefaultTableModel modelName = (DefaultTableModel) JTabelName.getModel();

Create a Vector with Vector vectorName = new Vector();

add so many row.add as comumns

add soon just add it with modelName.addRow(Vector name);

T-SQL: Using a CASE in an UPDATE statement to update certain columns depending on a condition

UPDATE  table
SET     columnx = CASE WHEN condition THEN 25 ELSE columnx END,
        columny = CASE WHEN condition THEN columny ELSE 25 END

JSONException: Value of type java.lang.String cannot be converted to JSONObject

see this http://stleary.github.io/JSON-java/org/json/JSONObject.html#JSONObject-java.lang.String-

JSONObject

public JSONObject(java.lang.String source)
           throws JSONException

Construct a JSONObject from a source JSON text string. This is the most commonly used` JSONObject constructor.

Parameters:
    source - `A string beginning with { (left brace) and ending with } (right brace).` 
Throws:
    JSONException - If there is a syntax error in the source string or a duplicated key.

you try to use some thing like:

new JSONObject("{your string}")

Content type 'application/x-www-form-urlencoded;charset=UTF-8' not supported for @RequestBody MultiValueMap

It seems that now you can just mark the method parameter with @RequestParam and it will do the job for you.

@PostMapping( "some/request/path" )
public void someControllerMethod( @RequestParam Map<String, String> body ) {
  //work with Map
}

How to drop column with constraint?

Find the default constraint with this query here:

SELECT
    df.name 'Constraint Name' ,
    t.name 'Table Name',
    c.NAME 'Column Name'
FROM sys.default_constraints df
INNER JOIN sys.tables t ON df.parent_object_id = t.object_id
INNER JOIN sys.columns c ON df.parent_object_id = c.object_id AND df.parent_column_id = c.column_id

This gives you the name of the default constraint, as well as the table and column name.

When you have that information you need to first drop the default constraint:

ALTER TABLE dbo.YourTable
DROP CONSTRAINT name-of-the-default-constraint-here

and then you can drop the column

ALTER TABLE dbo.YourTable DROP COLUMN YourColumn

Read from database and fill DataTable

Private Function LoaderData(ByVal strSql As String) As DataTable
    Dim cnn As SqlConnection
    Dim dad As SqlDataAdapter

    Dim dtb As New DataTable
    cnn = New SqlConnection(My.Settings.mySqlConnectionString)
    Try
        cnn.Open()
        dad = New SqlDataAdapter(strSql, cnn)
        dad.Fill(dtb)
        cnn.Close()
        dad.Dispose()
    Catch ex As Exception
        cnn.Close()
        MsgBox(ex.Message)
    End Try
    Return dtb
End Function

Check if string contains a value in array

You can concatenate the array values with implode and a separator of | and then use preg_match to search for the value.

Here is the solution I came up with ...

$emails = array('@gmail', '@hotmail', '@outlook', '@live', '@msn', '@yahoo', '@ymail', '@aol');
$emails = implode('|', $emails);

if(!preg_match("/$emails/i", $email)){
 // do something
}

How to import .py file from another directory?

You can add to the system-path at runtime:

import sys
sys.path.insert(0, 'path/to/your/py_file')

import py_file

This is by far the easiest way to do it.

How to remove the underline for anchors(links)?

I've been troubled with this problem in web printing and solved. Verified result.

a {
    text-decoration: none !important;
}

It works!.

What is a raw type and why shouldn't we use it?

What is a raw type and why do I often hear that they shouldn't be used in new code?

A "raw type" is the use of a generic class without specifying a type argument(s) for its parameterized type(s), e.g. using List instead of List<String>. When generics were introduced into Java, several classes were updated to use generics. Using these class as a "raw type" (without specifying a type argument) allowed legacy code to still compile.

"Raw types" are used for backwards compatibility. Their use in new code is not recommended because using the generic class with a type argument allows for stronger typing, which in turn may improve code understandability and lead to catching potential problems earlier.

What is the alternative if we can't use raw types, and how is it better?

The preferred alternative is to use generic classes as intended - with a suitable type argument (e.g. List<String>). This allows the programmer to specify types more specifically, conveys more meaning to future maintainers about the intended use of a variable or data structure, and it allows compiler to enforce better type-safety. These advantages together may improve code quality and help prevent the introduction of some coding errors.

For example, for a method where the programmer wants to ensure a List variable called 'names' contains only Strings:

List<String> names = new ArrayList<String>();
names.add("John");          // OK
names.add(new Integer(1));  // compile error

Segmentation Fault - C

Your scanf("%s", s); is commented out. That means s is uninitialized, so when this line ln = strlen(s); executes, you get a seg fault.

It always helps to initialize a pointer to NULL, and then test for null before using the pointer.

How to wait 5 seconds with jQuery?

I realize that this is an old question, but here's a plugin to address this issue that someone might find useful.

https://github.com/madbook/jquery.wait

lets you do this:

$('#myElement').addClass('load').wait(5000).addClass('done');

The reason why you should use .wait instead of .delay is because not all jquery functions are supported by .delay and that .delay only works with animation functions. For example delay does not support .addClass and .removeClass

Or you can use this function instead.

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

sleep(5000);

Python idiom to return first item or None

def head(iterable):
    try:
        return iter(iterable).next()
    except StopIteration:
        return None

print head(xrange(42, 1000)  # 42
print head([])               # None

BTW: I'd rework your general program flow into something like this:

lists = [
    ["first", "list"],
    ["second", "list"],
    ["third", "list"]
]

def do_something(element):
    if not element:
        return
    else:
        # do something
        pass

for li in lists:
    do_something(head(li))

(Avoiding repetition whenever possible)

JAXB :Need Namespace Prefix to all the elements

Another way is to tell the marshaller to always use a certain prefix

marshaller.setProperty("com.sun.xml.bind.namespacePrefixMapper", new NamespacePrefixMapper() {
             @Override
            public String getPreferredPrefix(String arg0, String arg1, boolean arg2) {
                return "ns1";
            }
        });'

virtualenvwrapper and Python 3

You can make virtualenvwrapper use a custom Python binary instead of the one virtualenvwrapper is run with. To do that you need to use VIRTUALENV_PYTHON variable which is utilized by virtualenv:

$ export VIRTUALENV_PYTHON=/usr/bin/python3
$ mkvirtualenv -a myproject myenv
Running virtualenv with interpreter /usr/bin/python3
New python executable in myenv/bin/python3
Also creating executable in myenv/bin/python
(myenv)$ python
Python 3.2.3 (default, Oct 19 2012, 19:53:16) 
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.

How do I duplicate a line or selection within Visual Studio Code?

Note that for Ubuntu users (<= 17.4), Unity uses CTRL + ALT + SHIFT + Arrow Key for moving programs across virtual workspaces, which conflicts with the VS Code shortcuts. You'll need to rebind editor.action.copyLinesDownAction and editor.action.copyLinesUpAction to avoid the conflict (or change your workspace keybindings).

For Ubuntu 17.10+ that uses GNOME, it seems that GNOME does not use this keybinding in the same way according to its documentation, though if someone using vanilla workspaces on 17.10 can confirm this, it might be helpful for future answer seekers.

double free or corruption (!prev) error in c program

I didn't check all the code but my guess is that the error is in the malloc call. You have to replace

 double *ptr = malloc(sizeof(double*) * TIME);

for

 double *ptr = malloc(sizeof(double) * TIME);

since you want to allocate size for a double (not the size of a pointer to a double).

In git how is fetch different than pull and how is merge different than rebase?

pull vs fetch:

The way I understand this, is that git pull is simply a git fetch followed by git merge. I.e. you fetch the changes from a remote branch and then merge it into the current branch.


merge vs rebase:

A merge will do as the command says; merge the differences between current branch and the specified branch (into the current branch). I.e. the command git merge another_branch will the merge another_branch into the current branch.

A rebase works a bit differently and is kind of cool. Let's say you perform the command git rebase another_branch. Git will first find the latest common version between the current branch and another_branch. I.e. the point before the branches diverged. Then git will move this divergent point to the head of the another_branch. Finally, all the commits in the current branch since the original divergent point are replayed from the new divergent point. This creates a very clean history, with fewer branches and merges.

However, it is not without pitfalls! Since the version history is "rewritten", you should only do this if the commits only exists in your local git repo. That is: Never do this if you have pushed the commits to a remote repo.

The explanation on rebasing given in this online book is quite good, with easy-to-understand illustrations.


pull with rebasing instead of merge

I'm actually using rebase quite a lot, but usually it is in combination with pull:

git pull --rebase

will fetch remote changes and then rebase instead of merge. I.e. it will replay all your local commits from the last time you performed a pull. I find this much cleaner than doing a normal pull with merging, which will create an extra commit with the merges.

How do you post to the wall on a facebook page (not profile)

Get PHP SDK from github and run the following code:

<?php
$attachment = array(
    'message' => 'this is my message',
    'name' => 'This is my demo Facebook application!',
    'caption' => "Caption of the Post",
    'link' => 'http://mylink.com',
    'description' => 'this is a description',
    'picture' => 'http://mysite.com/pic.gif',
    'actions' => array(
        array(
            'name' => 'Get Search',
            'link' => 'http://www.google.com'
        )
    )
);

$result = $facebook->api('/me/feed/', 'post', $attachment);

the above code will Post the message on to your wall... and if you want to post onto your friends or others wall then replace me with the Facebook User Id of that user..for further information look out the API Documentation.

PersistenceContext EntityManager injection NullPointerException

If you have any NamedQueries in your entity classes, then check the stack trace for compilation errors. A malformed query which cannot be compiled can cause failure to load the persistence context.

.Net picking wrong referenced assembly version

This isn't a clear answer as to why, but we had this problem, here's our circumstances and what solved it:

Dev 1:

Solution contains Project A referencing a NuGet Package, and an MVC project referencing Project A. Enabled NuGet Package Restore, then updated the NuGet package. Got a runtime error complaining the NuGet lib can't be found - but the error is it looking for the older, non-updated version. Solution (and this is ridiculous): Set a breakpoint on the first line of code in the MVC project that calls Project A. Step in with F11. Solved - never had a problem again.

Dev 2:

Same solution and projects, but the magic set breakpoint and step in solution doesn't work. Looked everywhere for version redirects or other bad references to this Nuget package, removed package and reinstalled it, wiped bin, obj, Asp.Net Temp, nothing solved it. Finally, renamed Project A, ran the MVC project - fixed. Renamed it back to its original name, it stayed fixed.

I don't have any explanation for why that worked, but it did get us out of a serious lurch.

Correct way to create rounded corners in Twitter Bootstrap

I guess it is what you are looking for: http://blogsh.de/tag/bootstrap-less/

@import 'bootstrap.less';
div.my-class {
    .border-radius( 5px );
}

You can use it because there is a mixin:

.border-radius(@radius: 5px) {
  -webkit-border-radius: @radius;
     -moz-border-radius: @radius;
          border-radius: @radius;
}

For Bootstrap 3, there are 4 mixins you can use...

.border-top-radius(@radius);
.border-right-radius(@radius);
.border-bottom-radius(@radius);
.border-left-radius(@radius);

or you can make your own mixin using the top 4 to do it in one shot.

.border-radius(@radius){
    .border-top-radius(@radius);
    .border-right-radius(@radius);
    .border-bottom-radius(@radius);
    .border-left-radius(@radius);
}

Android Facebook style slide

With android support package revision 13( may 2013), there is DrawerLayout for creating a Navigation Drawer that can be pulled in from the edge of a window. And, navigation drawer is a design pattern now.

v4 support library

navigation drawer design pattern

How can I query for null values in entity framework?

If you prefer using method (lambda) syntax as I do, you could do the same thing like this:

var result = new TableName();

using(var db = new EFObjectContext)
{
    var query = db.TableName;

    query = value1 == null 
        ? query.Where(tbl => tbl.entry1 == null) 
        : query.Where(tbl => tbl.entry1 == value1);

    query = value2 == null 
        ? query.Where(tbl => tbl.entry2 == null) 
        : query.Where(tbl => tbl.entry2 == value2);

    result = query
        .Select(tbl => tbl)
        .FirstOrDefault();

   // Inspect the value of the trace variable below to see the sql generated by EF
   var trace = ((ObjectQuery<REF_EQUIPMENT>) query).ToTraceString();

}

return result;

Delete an element in a JSON object

with open('writing_file.json', 'w') as w:
    with open('reading_file.json', 'r') as r:
        for line in r:
            element = json.loads(line.strip())
            if 'hours' in element:
                del element['hours']
            w.write(json.dumps(element))

this is the method i use..

Convert an image to grayscale

None of the examples above create 8-bit (8bpp) bitmap images. Some software, such as image processing, only supports 8bpp. Unfortunately the MS .NET libraries do not have a solution. The PixelFormat.Format8bppIndexed format looks promising but after a lot of attempts I couldn't get it working.

To create a true 8-bit bitmap file you need to create the proper headers. Ultimately I found the Grayscale library solution for creating 8-bit bitmap (BMP) files. The code is very simple:

Image image = Image.FromFile("c:/path/to/image.jpg");
GrayBMP_File.CreateGrayBitmapFile(image, "c:/path/to/8bpp/image.bmp");

The code for this project is far from pretty but it works, with one little simple-to-fix problem. The author hard-coded the image resolution to 10x10. Image processing programs do not like this. The fix is open GrayBMP_File.cs (yeah, funky file naming, I know) and replace lines 50 and 51 with the code below. The example sets the resolution to 200x200 but you should change it to the proper number.

int resX = 200;
int resY = 200;
// horizontal resolution
Copy_to_Index(DIB_header, BitConverter.GetBytes(resX * 100), 24);
// vertical resolution 
Copy_to_Index(DIB_header, BitConverter.GetBytes(resY * 100), 28);

SQL Server - Adding a string to a text column (concat equivalent)

hmm, try doing CAST(' ' AS TEXT) + [myText]

Although, i am not completely sure how this will pan out.

I also suggest against using the Text datatype, use varchar instead.

If that doesn't work, try ' ' + CAST ([myText] AS VARCHAR(255))

How does the enhanced for statement work for arrays, and how to get an iterator for an array?

I like the answer from 30thh using Iterators from Guava. However, from some frameworks I get null instead of an empty array, and Iterators.forArray(array) does not handle that well. So I came up with this helper method, which you can call with Iterator<String> it = emptyIfNull(array);

public static <F> UnmodifiableIterator<F> emptyIfNull(F[] array) {
    if (array != null) {
        return Iterators.forArray(array);
    }
    return new UnmodifiableIterator<F>() {
        public boolean hasNext() {
            return false;
        }

        public F next() {
            return null;
        }
    };
}

git checkout master error: the following untracked working tree files would be overwritten by checkout

do a :

git branch

if git show you something like :

* (no branch)
master
Dbranch

You have a "detached HEAD". If you have modify some files on this branch you, commit them, then return to master with

git checkout master 

Now you should be able to delete the Dbranch.

Angular2 QuickStart npm start is not working correctly

If you use proxy it may cause this error:

  1. npm config set proxy http://username:pass@proxy:port

  2. npm config set https-proxy http://username:pass@proxy:port

  3. create a file named .typingsrc in your application folder that includes:

    • proxy = (value on step 1)
    • https-proxy = (value on step 1)
  4. run npm cache clean

  5. run npm install
  6. run npm typings install
  7. run npm start

it will work then

How to format DateTime to 24 hours time?

Console.WriteLine(curr.ToString("HH:mm"));

JIRA JQL searching by date - is there a way of getting Today() (Date) instead of Now() (DateTime)

In case you want to search for all the issues updated after 9am previous day until today at 9AM, please try: updated >= startOfDay(-15h) and updated <= startOfDay(9h). (explanation: 9AM - 24h/day = -15h)

You can also use updated >= startOfDay(-900m) . where 900m = 15h*60m

Reference: https://confluence.atlassian.com/display/JIRA/Advanced+Searching

Google Maps V3 - How to calculate the zoom level for a given bounds

map.getBounds() is not momentary operation, so I use in similar case event handler. Here is my example in Coffeescript

@map.fitBounds(@bounds)
google.maps.event.addListenerOnce @map, 'bounds_changed', =>
  @map.setZoom(12) if @map.getZoom() > 12

SQL: set existing column as Primary Key in MySQL

Either run in SQL:

ALTER TABLE tableName
  ADD PRIMARY KEY (id)           ---or Drugid, whichever you want it to be PK

or use the PHPMyAdmin interface (Table Structure)

Turn off axes in subplots

import matplotlib.pyplot as plt

fig, ax = plt.subplots(2, 2)


To turn off axes for all subplots, do either:

[axi.set_axis_off() for axi in ax.ravel()]

or

map(lambda axi: axi.set_axis_off(), ax.ravel())

Xamarin 2.0 vs Appcelerator Titanium vs PhoneGap

I have worked with Xamarin. Here are the positives and negatives I have found:

Positives

  1. Easy to code, C# makes the job easier
  2. Performance won't be a concern
  3. Native UI
  4. Good IDE, much like Xcode and Visual Studio.
  5. Xamarin Debugger
  6. Xamarin SDK is free and open-source. Wiki

Negatives

  1. You need to know the API for each platform you want to target (iOS, Android, WP8). However, you do not need to know Objective-C or Java.
  2. Xamarin shares only a few things across platforms (things like databases and web services).
  3. You have to design the UI of each platform separately (this can be a blessing or a curse).

where to place CASE WHEN column IS NULL in this query

Thanks for all your help! @Svetoslav Tsolov had it very close, but I was still getting an error, until I figured out the closing parenthesis was in the wrong place. Here's the final query that works:

SELECT dbo.AdminID.CountryID, dbo.AdminID.CountryName, dbo.AdminID.RegionID, 
dbo.AdminID.[Region name], dbo.AdminID.DistrictID, dbo.AdminID.DistrictName,
dbo.AdminID.ADMIN3_ID, dbo.AdminID.ADMIN3,
(CASE WHEN dbo.EU_Admin3.EUID IS NULL THEN dbo.EU_Admin2.EUID ELSE dbo.EU_Admin3.EUID END) AS EUID
FROM dbo.AdminID 

LEFT OUTER JOIN dbo.EU_Admin2
ON dbo.AdminID.DistrictID = dbo.EU_Admin2.DistrictID

LEFT OUTER JOIN dbo.EU_Admin3
ON dbo.AdminID.ADMIN3_ID = dbo.EU_Admin3.ADMIN3_ID

When should I use cross apply over inner join?

It seems to me that CROSS APPLY can fill a certain gap when working with calculated fields in complex/nested queries, and make them simpler and more readable.

Simple example: you have a DoB and you want to present multiple age-related fields that will also rely on other data sources (such as employment), like Age, AgeGroup, AgeAtHiring, MinimumRetirementDate, etc. for use in your end-user application (Excel PivotTables, for example).

Options are limited and rarely elegant:

  • JOIN subqueries cannot introduce new values in the dataset based on data in the parent query (it must stand on its own).

  • UDFs are neat, but slow as they tend to prevent parallel operations. And being a separate entity can be a good (less code) or a bad (where is the code) thing.

  • Junction tables. Sometimes they can work, but soon enough you're joining subqueries with tons of UNIONs. Big mess.

  • Create yet another single-purpose view, assuming your calculations don't require data obtained mid-way through your main query.

  • Intermediary tables. Yes... that usually works, and often a good option as they can be indexed and fast, but performance can also drop due to to UPDATE statements not being parallel and not allowing to cascade formulas (reuse results) to update several fields within the same statement. And sometimes you'd just prefer to do things in one pass.

  • Nesting queries. Yes at any point you can put parenthesis on your entire query and use it as a subquery upon which you can manipulate source data and calculated fields alike. But you can only do this so much before it gets ugly. Very ugly.

  • Repeating code. What is the greatest value of 3 long (CASE...ELSE...END) statements? That's gonna be readable!

    • Tell your clients to calculate the damn things themselves.

Did I miss something? Probably, so feel free to comment. But hey, CROSS APPLY is like a godsend in such situations: you just add a simple CROSS APPLY (select tbl.value + 1 as someFormula) as crossTbl and voilà! Your new field is now ready for use practically like it had always been there in your source data.

Values introduced through CROSS APPLY can...

  • be used to create one or multiple calculated fields without adding performance, complexity or readability issues to the mix
  • like with JOINs, several subsequent CROSS APPLY statements can refer to themselves: CROSS APPLY (select crossTbl.someFormula + 1 as someMoreFormula) as crossTbl2
  • you can use values introduced by a CROSS APPLY in subsequent JOIN conditions
  • As a bonus, there's the Table-valued function aspect

Dang, there's nothing they can't do!

What does @media screen and (max-width: 1024px) mean in CSS?

That's Media Queries. It allows you to apply part of CSS rules only to the specific devices on specific configuration.

Hibernate: Automatically creating/updating the db tables based on entity classes

There is one very important detail, than can possibly stop your hibernate from generating tables (assuming You already have set the hibernate.hbm2ddl.auto). You will also need the @Table annotation!

@Entity
@Table(name = "test_entity")
    public class TestEntity {
}

It has already helped in my case at least 3 times - still cannot remember it ;)

PS. Read the hibernate docs - in most cases You will probably not want to set hibernate.hbm2ddl.auto to create-drop, because it deletes Your tables after stopping the app.

How can prepared statements protect from SQL injection attacks?

The key phrase is need not be correctly escaped. That means that you don't to worry about people trying to throw in dashes, apostrophes, quotes, etc...

It is all handled for you.

What is the significance of url-pattern in web.xml and how to configure servlet?

url-pattern is used in web.xml to map your servlet to specific URL. Please see below xml code, similar code you may find in your web.xml configuration file.

<servlet>
    <servlet-name>AddPhotoServlet</servlet-name>  //servlet name
    <servlet-class>upload.AddPhotoServlet</servlet-class>  //servlet class
</servlet>
 <servlet-mapping>
    <servlet-name>AddPhotoServlet</servlet-name>   //servlet name
    <url-pattern>/AddPhotoServlet</url-pattern>  //how it should appear
</servlet-mapping>

If you change url-pattern of AddPhotoServlet from /AddPhotoServlet to /MyUrl. Then, AddPhotoServlet servlet can be accessible by using /MyUrl. Good for the security reason, where you want to hide your actual page URL.

Java Servlet url-pattern Specification:

  1. A string beginning with a '/' character and ending with a '/*' suffix is used for path mapping.
  2. A string beginning with a '*.' prefix is used as an extension mapping.
  3. A string containing only the '/' character indicates the "default" servlet of the application. In this case the servlet path is the request URI minus the context path and the path info is null.
  4. All other strings are used for exact matches only.

Reference : Java Servlet Specification

You may also read this Basics of Java Servlet

Regex to match alphanumeric and spaces

The circumflex inside the square brackets means all characters except the subsequent range. You want a circumflex outside of square brackets.

What is a loop invariant?

It is hard to keep track of what is happening with loops. Loops which don't terminate or terminate without achieving their goal behavior is a common problem in computer programming. Loop invariants help. A loop invariant is a formal statement about the relationship between variables in your program which holds true just before the loop is ever run (establishing the invariant) and is true again at the bottom of the loop, each time through the loop (maintaining the invariant). Here is the general pattern of the use of Loop Invariants in your code:

... // the Loop Invariant must be true here
while ( TEST CONDITION ) {
// top of the loop
...
// bottom of the loop
// the Loop Invariant must be true here
}
// Termination + Loop Invariant = Goal
...
Between the top and bottom of the loop, headway is presumably being made towards reaching the loop's goal. This might disturb (make false) the invariant. The point of Loop Invariants is the promise that the invariant will be restored before repeating the loop body each time. There are two advantages to this:

Work is not carried forward to the next pass in complicated, data dependent ways. Each pass through the loop in independent of all others, with the invariant serving to bind the passes together into a working whole. Reasoning that your loop works is reduced to reasoning that the loop invariant is restored with each pass through the loop. This breaks the complicated overall behavior of the loop into small simple steps, each which can be considered separately. The test condition of the loop is not part of the invariant. It is what makes the loop terminate. You consider separately two things: why the loop should ever terminate, and why the loop achieves its goal when it terminates. The loop will terminate if each time through the loop you move closer to satisfying the termination condition. It is often easy to assure this: e.g. stepping a counter variable by one until it reaches a fixed upper limit. Sometimes the reasoning behind termination is more difficult.

The loop invariant should be created so that when the condition of termination is attained, and the invariant is true, then the goal is reached:

invariant + termination => goal
It takes practice to create invariants which are simple and relate which capture all of goal attainment except for termination. It is best to use mathematical symbols to express loop invariants, but when this leads to over-complicated situations, we rely on clear prose and common-sense.

Is there a way to suppress JSHint warning for one given line?

As you can see in the documentation of JSHint you can change options per function or per file. In your case just place a comment in your file or even more local just in the function that uses eval:

/*jshint evil:true */

function helloEval(str) {
    /*jshint evil:true */
    eval(str);
}

Determine the number of NA values in a column

Try this:

length(df$col[is.na(df$col)])

How to know if a Fragment is Visible?

You should be able to do the following:

MyFragmentClass test = (MyFragmentClass) getSupportFragmentManager().findFragmentByTag("testID");
if (test != null && test.isVisible()) {
     //DO STUFF
}
else {
    //Whatever
}

How to unzip a file using the command line?

Grab an executable from info-zip.

Info-ZIP supports hardware from microcomputers all the way up to Cray supercomputers, running on almost all versions of Unix, VMS, OS/2, Windows 9x/NT/etc. (a.k.a. Win32), Windows 3.x, Windows CE, MS-DOS, AmigaDOS, Atari TOS, Acorn RISC OS, BeOS, Mac OS, SMS/QDOS, MVS and OS/390 OE, VM/CMS, FlexOS, Tandem NSK and Human68K (Japanese). There is also some (old) support for LynxOS, TOPS-20, AOS/VS and Novell NLMs. Shared libraries (DLLs) are available for Unix, OS/2, Win32 and Win16, and graphical interfaces are available for Win32, Win16, WinCE and Mac OS.

In Python how should I test if a variable is None, True or False

if result is None:
    print "error parsing stream"
elif result:
    print "result pass"
else:
    print "result fail"

keep it simple and explicit. You can of course pre-define a dictionary.

messages = {None: 'error', True: 'pass', False: 'fail'}
print messages[result]

If you plan on modifying your simulate function to include more return codes, maintaining this code might become a bit of an issue.

The simulate might also raise an exception on the parsing error, in which case you'd either would catch it here or let it propagate a level up and the printing bit would be reduced to a one-line if-else statement.

how to start stop tomcat server using CMD?

Create a .bat file and write two commands:

cd C:\ Path to your tomcat directory \ bin

startup.bat

Now on double-click, Tomcat server will start.

Passing ArrayList from servlet to JSP

<html>
    <%

        ArrayList<Actor> list = new ArrayList<Actor>();
        list = (ArrayList<Actor>) request.getAttribute("actors");
    %>
<head>
    <link rel="stylesheet" type="text/css" href="style.css">
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Actor</title>
</head>

<body>

    <h2>This is Actor Class</h2>
    <table>
        <thead>
            <tr>
                <th>Id</th>
                <th>First Name</th>
                <th>Last Name</th>
            </tr>
        </thead>
        <tbody>
            <% for(int i = 0; i < list.size(); i++) {
                Actor actor = new Actor();
                actor = list.get(i);
                //out.println(actor.getId());
                //out.println(actor.getFirstname());
                //out.println(actor.getLastname());
            %>


            <tr>
                <td><%=actor.getId()%></td>
                <td><%=actor.getFirstname()%></td>
                <td><%=actor.getLastname()%></td>
               </tr>
            <%
            };
            %>
        </tbody>
    </table>

</body>

What should be in my .gitignore for an Android Studio project?

My advise would be also to not ignore the .idea folder.

I've imported a Git-based Eclipse project to Android Studio and that went fine. Later, I wanted to import this project with Git (like the first time) to another machine with Android Studio, but that didn't worked. Android Studio did load all the files but wasn't able to "see" the project as a project. I only could open Git-files.

While importing the project for the first time (from Eclipse to Android Studio) my old .gitignore was overwritten and the new one looked like this:

  • .idea/.name
  • .idea/compiler.xml
  • .idea/copyright/profiles_settings.xml
  • .idea/encodings.xml
  • .idea/libraries/libs.xml
  • .idea/misc.xml
  • .idea/modules.xml
  • .idea/scopes/scope_settings.xml
  • .idea/vcs.xml
  • .idea/workspace.xml

So, I tried to use an empty gitignore and now it worked. The other Android Studio could load the files and the Project. I guess some files are not important (profiles_settings.xml) for Git and importing but I am just happy it worked.

Printing PDFs from Windows Command Line

Looks like you are missing the printer name, driver, and port - in that order. Your final command should resemble:

AcroRd32.exe /t <file.pdf> <printer_name> <printer_driver> <printer_port>

For example:

"C:\Program Files (x86)\Adobe\Reader 11.0\Reader\AcroRd32.exe" /t "C:\Folder\File.pdf" "Brother MFC-7820N USB Printer" "Brother MFC-7820N USB Printer" "IP_192.168.10.110"

Note: To find the printer information, right click your printer and choose properties. In my case shown above, the printer name and driver name matched - but your information may differ.

How to use a App.config file in WPF applications?

You have to add the reference to System.configuration in your solution. Also, include using System.Configuration;. Once you do that, you'll have access to all the configuration settings.

AngularJS: How to set a variable inside of a template?

Use ngInit: https://docs.angularjs.org/api/ng/directive/ngInit

<div ng-repeat="day in forecast_days" ng-init="f = forecast[day.iso]">
  {{$index}} - {{day.iso}} - {{day.name}}
  Temperature: {{f.temperature}}<br>
  Humidity: {{f.humidity}}<br>
  ...
</div>

Example: http://jsfiddle.net/coma/UV4qF/

python socket.error: [Errno 98] Address already in use

There is obviously another process listening on the port. You might find out that process by using the following command:

$ lsof -i :8000

or change your tornado app's port. tornado's error info not Explicitly on this.

How can you search Google Programmatically Java API

In the Terms of Service of google we can read:

5.3 You agree not to access (or attempt to access) any of the Services by any means other than through the interface that is provided by Google, unless you have been specifically allowed to do so in a separate agreement with Google. You specifically agree not to access (or attempt to access) any of the Services through any automated means (including use of scripts or web crawlers) and shall ensure that you comply with the instructions set out in any robots.txt file present on the Services.

So I guess the answer is No. More over the SOAP API is no longer available

What does the function then() mean in JavaScript?

then() function is related to "Javascript promises" that are used in some libraries or frameworks like jQuery or AngularJS.

A promise is a pattern for handling asynchronous operations. The promise allows you to call a method called "then" that lets you specify the function(s) to use as the callbacks.

For more information see: http://wildermuth.com/2013/8/3/JavaScript_Promises

And for Angular promises: http://liamkaufman.com/blog/2013/09/09/using-angularjs-promises/

How to source virtualenv activate in a Bash script

You should use multiple commands in one line. for example:

os.system(". Projects/virenv/bin/activate && python Projects/virenv/django-project/manage.py runserver")

when you activate your virtual environment in one line, I think it forgets for other command lines and you can prevent this by using multiple commands in one line. It worked for me :)

Java String split removed empty values

String[] split = data.split("\\|",-1);

This is not the actual requirement in all the time. The Drawback of above is show below:

Scenerio 1:
When all data are present:
    String data = "5|6|7||8|9|10|";
    String[] split = data.split("\\|");
    String[] splt = data.split("\\|",-1);
    System.out.println(split.length); //output: 7
    System.out.println(splt.length); //output: 8

When data is missing:

Scenerio 2: Data Missing
    String data = "5|6|7||8|||";
    String[] split = data.split("\\|");
    String[] splt = data.split("\\|",-1);
    System.out.println(split.length); //output: 5
    System.out.println(splt.length); //output: 8

Real requirement is length should be 7 although there is data missing. Because there are cases such as when I need to insert in database or something else. We can achieve this by using below approach.

    String data = "5|6|7||8|||";
    String[] split = data.split("\\|");
    String[] splt = data.replaceAll("\\|$","").split("\\|",-1);
    System.out.println(split.length); //output: 5
    System.out.println(splt.length); //output:7

What I've done here is, I'm removing "|" pipe at the end and then splitting the String. If you have "," as a seperator then you need to add ",$" inside replaceAll.

Call Javascript onchange event by programmatically changing textbox value

The "onchange" is only fired when the attribute is programmatically changed or when the user makes a change and then focuses away from the field.

Have you looked at using YUI's calendar object? I've coded up a solution that puts the yui calendar inside a yui panel and hides the panel until an associated image is clicked. I'm able to see changes from either.

http://developer.yahoo.com/yui/examples/calendar/formtxt.html

Eclipse Error: "Failed to connect to remote VM"

Have you setup the remote VM to accept connections?

java -Xdebug -Xrunjdwp:server=y,transport=dt_socket,address=10000,suspend=n yourServer

Is there a firewall in the way?

Are you specifying the correct host / port?

Are you connected to a VPN?

jQuery: print_r() display equivalent?

You could use very easily reflection to list all properties, methods and values.

For Gecko based browsers you can use the .toSource() method:

var data = new Object();
data["firstname"] = "John";
data["lastname"] = "Smith";
data["age"] = 21;

alert(data.toSource()); //Will return "({firstname:"John", lastname:"Smith", age:21})"

But since you use Firebug, why not just use console.log?

download a file from Spring boot rest service

The below Sample code worked for me and might help someone.

import org.springframework.core.io.ByteArrayResource;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

@RestController
@RequestMapping("/app")
public class ImageResource {

    private static final String EXTENSION = ".jpg";
    private static final String SERVER_LOCATION = "/server/images";

    @RequestMapping(path = "/download", method = RequestMethod.GET)
    public ResponseEntity<Resource> download(@RequestParam("image") String image) throws IOException {
        File file = new File(SERVER_LOCATION + File.separator + image + EXTENSION);

        HttpHeaders header = new HttpHeaders();
        header.add(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=img.jpg");
        header.add("Cache-Control", "no-cache, no-store, must-revalidate");
        header.add("Pragma", "no-cache");
        header.add("Expires", "0");

        Path path = Paths.get(file.getAbsolutePath());
        ByteArrayResource resource = new ByteArrayResource(Files.readAllBytes(path));

        return ResponseEntity.ok()
                .headers(header)
                .contentLength(file.length())
                .contentType(MediaType.parseMediaType("application/octet-stream"))
                .body(resource);
    }

}

What Does This Mean in PHP -> or =>

The double arrow operator, =>, is used as an access mechanism for arrays. This means that what is on the left side of it will have a corresponding value of what is on the right side of it in array context. This can be used to set values of any acceptable type into a corresponding index of an array. The index can be associative (string based) or numeric.

$myArray = array(
    0 => 'Big',
    1 => 'Small',
    2 => 'Up',
    3 => 'Down'
);

The object operator, ->, is used in object scope to access methods and properties of an object. It’s meaning is to say that what is on the right of the operator is a member of the object instantiated into the variable on the left side of the operator. Instantiated is the key term here.

// Create a new instance of MyObject into $obj
$obj = new MyObject();
// Set a property in the $obj object called thisProperty
$obj->thisProperty = 'Fred';
// Call a method of the $obj object named getProperty
$obj->getProperty();

Join between tables in two different databases?

Yes, assuming the account has appropriate permissions you can use:

SELECT <...>
FROM A.table1 t1 JOIN B.table2 t2 ON t2.column2 = t1.column1;

You just need to prefix the table reference with the name of the database it resides in.

Adding simple legend to plot in R

Take a look at ?legend and try this:

legend('topright', names(a)[-1] , 
   lty=1, col=c('red', 'blue', 'green',' brown'), bty='n', cex=.75)

enter image description here

"Series objects are mutable and cannot be hashed" error

Shortly: gene_name[x] is a mutable object so it cannot be hashed. To use an object as a key in a dictionary, python needs to use its hash value, and that's why you get an error.

Further explanation:

Mutable objects are objects which value can be changed. For example, list is a mutable object, since you can append to it. int is an immutable object, because you can't change it. When you do:

a = 5;
a = 3;

You don't change the value of a, you create a new object and make a point to its value.

Mutable objects cannot be hashed. See this answer.

To solve your problem, you should use immutable objects as keys in your dictionary. For example: tuple, string, int.

Extracting columns from text file with different delimiters in Linux

If the command should work with both tabs and spaces as the delimiter I would use awk:

awk '{print $100,$101,$102,$103,$104,$105}' myfile > outfile

As long as you just need to specify 5 fields it is imo ok to just type them, for longer ranges you can use a for loop:

awk '{for(i=100;i<=105;i++)print $i}' myfile > outfile

If you want to use cut, you need to use the -f option:

cut -f100-105 myfile > outfile

If the field delimiter is different from TAB you need to specify it using -d:

cut -d' ' -f100-105 myfile > outfile

Check the man page for more info on the cut command.

Adding blank spaces to layout

If you don't need the gap to be exactly 2 lines high, you can add an empty view like this:

    <View
        android:layout_width="fill_parent"
        android:layout_height="30dp">
    </View>

Cannot open new Jupyter Notebook [Permission Denied]

Based on my experience on Ubuntu 18.04:

1. Check Jupyter installation

first of all make sure that you have installed and/or upgraded Jupyter-notebook (also for virtual-environment):

pip install --upgrade jupyter 

2. Change the Access Permissions (Use with Caution!)

then try to change the access permission for you

sudo chmod -R 777 ~/.local

where 777 is a three-digit representation of the access permission. In sense that each of the digits representing short format of the binary one (e.g. 7 for 111). So, 777 means that we set permission access to read, write and execute to 1 for all users (Owner, Group or Other)

Example.1

777 : 111 111 111

or

777 : rwx-rwx-rwx

Example.2

755 : 111 101 101

  • Owner: rwx=4+2+1=7
  • Group: r-x=4+0+1=5
  • Other: r-x=4+0+1=5

(More about chmod : File Permissions and attributes)

3. Run jupyter

afterwards run your jupyter notebook:

jupyter-notebook

Note: (These steps also solve your Visual-Studio code (VS-Code) problems regarding permissions while using ipython and jupyter for python-interactive-console.)

Git merge errors

It's worth understanding what those error messages mean - needs merge and error: you need to resolve your current index first indicate that a merge failed, and that there are conflicts in those files. If you've decided that whatever merge you were trying to do was a bad idea after all, you can put things back to normal with:

git reset --merge

However, otherwise you should resolve those merge conflicts, as described in the git manual.


Once you've dealt with that by either technique you should be able to checkout the 9-sign-in-out branch. The problem with just renaming your 9-sign-in-out to master, as suggested in wRAR's answer is that if you've shared your previous master branch with anyone, this will create problems for them, since if the history of the two branches diverged, you'll be publishing rewritten history.

Essentially what you want to do is to merge your topic branch 9-sign-in-out into master but exactly keep the versions of the files in the topic branch. You could do this with the following steps:

# Switch to the topic branch:
git checkout 9-sign-in-out

# Create a merge commit, which looks as if it's merging in from master, but is
# actually discarding everything from the master branch and keeping everything
# from 9-sign-in-out:
git merge -s ours master

# Switch back to the master branch:
git checkout master

# Merge the topic branch into master - this should now be a fast-forward
# that leaves you with master exactly as 9-sign-in-out was:
git merge 9-sign-in-out

How can I replace non-printable Unicode characters in Java?

You may be interested in the Unicode categories "Other, Control" and possibly "Other, Format" (unfortunately the latter seems to contain both unprintable and printable characters).

In Java regular expressions you can check for them using \p{Cc} and \p{Cf} respectively.

Open PDF in new browser full window

I'm going to take a chance here and actually advise against this. I suspect that people wanting to view your PDFs will already have their viewers set up the way they want, and will not take kindly to you taking that choice away from them :-)

Why not just stream down the content with the correct content specifier?

That way, newbies will get whatever their browser developer has a a useful default, and those of us that know how to configure such things will see it as we want to.

How to use the priority queue STL for objects?

This piece of code may help..

#include <bits/stdc++.h>
using namespace std;    

class node{
public:
    int age;
    string name;
    node(int a, string b){
        age = a;
        name = b;
    }
};

bool operator<(const node& a, const node& b) {

    node temp1=a,temp2=b;
    if(a.age != b.age)
        return a.age > b.age;
    else{
        return temp1.name.append(temp2.name) > temp2.name.append(temp1.name);
    }
}

int main(){
    priority_queue<node> pq;
    node b(23,"prashantandsoon..");
    node a(22,"prashant");
    node c(22,"prashantonly");
    pq.push(b);
    pq.push(a);
    pq.push(c);

    int size = pq.size();
    for (int i = 0; i < size; ++i)
    {
        cout<<pq.top().age<<" "<<pq.top().name<<"\n";
        pq.pop();
    }
}

Output:

22 prashantonly
22 prashant
23 prashantandsoon..

Create a Dropdown List for MVC3 using Entity Framework (.edmx Model) & Razor Views && Insert A Database Record to Multiple Tables

Don't pass db models directly to your views. You're lucky enough to be using MVC, so encapsulate using view models.

Create a view model class like this:

public class EmployeeAddViewModel
{
    public Employee employee { get; set; }
    public Dictionary<int, string> staffTypes { get; set; }
    // really? a 1-to-many for genders
    public Dictionary<int, string> genderTypes { get; set; }

    public EmployeeAddViewModel() { }
    public EmployeeAddViewModel(int id)
    {
        employee = someEntityContext.Employees
            .Where(e => e.ID == id).SingleOrDefault();

        // instantiate your dictionaries

        foreach(var staffType in someEntityContext.StaffTypes)
        {
            staffTypes.Add(staffType.ID, staffType.Type);
        }

        // repeat similar loop for gender types
    }
}

Controller:

[HttpGet]
public ActionResult Add()
{
    return View(new EmployeeAddViewModel());
}

[HttpPost]
public ActionResult Add(EmployeeAddViewModel vm)
{
    if(ModelState.IsValid)
    {
        Employee.Add(vm.Employee);
        return View("Index"); // or wherever you go after successful add
    }

    return View(vm);
}

Then, finally in your view (which you can use Visual Studio to scaffold it first), change the inherited type to ShadowVenue.Models.EmployeeAddViewModel. Also, where the drop down lists go, use:

@Html.DropDownListFor(model => model.employee.staffTypeID,
    new SelectList(model.staffTypes, "ID", "Type"))

and similarly for the gender dropdown

@Html.DropDownListFor(model => model.employee.genderID,
    new SelectList(model.genderTypes, "ID", "Gender"))

Update per comments

For gender, you could also do this if you can be without the genderTypes in the above suggested view model (though, on second thought, maybe I'd generate this server side in the view model as IEnumerable). So, in place of new SelectList... below, you would use your IEnumerable.

@Html.DropDownListFor(model => model.employee.genderID,
    new SelectList(new SelectList()
    {
        new { ID = 1, Gender = "Male" },
        new { ID = 2, Gender = "Female" }
    }, "ID", "Gender"))

Finally, another option is a Lookup table. Basically, you keep key-value pairs associated with a Lookup type. One example of a type may be gender, while another may be State, etc. I like to structure mine like this:

ID | LookupType | LookupKey | LookupValue | LookupDescription | Active
1  | Gender     | 1         | Male        | male gender       | 1
2  | State      | 50        | Hawaii      | 50th state        | 1
3  | Gender     | 2         | Female      | female gender     | 1
4  | State      | 49        | Alaska      | 49th state        | 1
5  | OrderType  | 1         | Web         | online order      | 1

I like to use these tables when a set of data doesn't change very often, but still needs to be enumerated from time to time.

Hope this helps!

PDF to image using Java

In Ghost4J library (http://ghost4j.sourceforge.net), since version 0.4.0 you can use a SimpleRenderer to do the job with few lines of code:

  1. Load PDF or PS file (use PSDocument class for that):

        PDFDocument document = new PDFDocument();
        document.load(new File("input.pdf"));
    
  2. Create the renderer

        SimpleRenderer renderer = new SimpleRenderer();
    
        // set resolution (in DPI)
        renderer.setResolution(300);
    
  3. Render

        List<Image> images = renderer.render(document);
    

Then you can do what you want with your image objects, for example, you can write them as PNG like this:

            for (int i = 0; i < images.size(); i++) {
                ImageIO.write((RenderedImage) images.get(i), "png", new File((i + 1) + ".png"));
            }

Note: Ghost4J uses the native Ghostscript C API so you need to have a Ghostscript installed on your box.

I hope it will help you :)

Android webview & localStorage

A solution that works on my Android 4.2.2, compiled with build target Android 4.4W:

WebSettings settings = webView.getSettings();
settings.setDomStorageEnabled(true);
settings.setDatabaseEnabled(true);

if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
    File databasePath = getDatabasePath("yourDbName");
    settings.setDatabasePath(databasePath.getPath());
}

Map and filter an array at the same time

One line reduce with ES6 fancy spread syntax is here!

_x000D_
_x000D_
var options = [_x000D_
  { name: 'One', assigned: true }, _x000D_
  { name: 'Two', assigned: false }, _x000D_
  { name: 'Three', assigned: true }, _x000D_
];_x000D_
_x000D_
const filtered = options_x000D_
  .reduce((result, {name, assigned}) => [...result, ...assigned ? [name] : []], []);_x000D_
_x000D_
console.log(filtered);
_x000D_
_x000D_
_x000D_

Get hostname of current request in node.js Express

You can use the os Module:

var os = require("os");
os.hostname();

See http://nodejs.org/docs/latest/api/os.html#os_os_hostname

Caveats:

  1. if you can work with the IP address -- Machines may have several Network Cards and unless you specify it node will listen on all of them, so you don't know on which NIC the request came in, before it comes in.

  2. Hostname is a DNS matter -- Don't forget that several DNS aliases can point to the same machine.

The infamous java.sql.SQLException: No suitable driver found

I've forgot to add the PostgreSQL JDBC Driver into my project (Mvnrepository).

Gradle:

// http://mvnrepository.com/artifact/postgresql/postgresql
compile group: 'postgresql', name: 'postgresql', version: '9.0-801.jdbc4'

Maven:

<dependency>
    <groupId>postgresql</groupId>
    <artifactId>postgresql</artifactId>
    <version>9.0-801.jdbc4</version>
</dependency>

You can also download the JAR and import to your project manually.

Understanding the Rails Authenticity Token

What is an authentication_token ?

This is a random string used by rails application to make sure that the user is requesting or performing an action from the app page, not from another app or site.

Why is an authentication_token is necessary ?

To protect your app or site from cross-site request forgery.

How to add an authentication_token to a form ?

If you are generating a form using form_for tag an authentication_token is automatically added else you can use <%= csrf_meta_tag %>.

How to try convert a string to a Guid

new Guid(string)

You could also look at using a TypeConverter.

Appending a byte[] to the end of another byte[]

First you need to allocate an array of the combined length, then use arraycopy to fill it from both sources.

byte[] ciphertext = blah;
byte[] mac = blah;
byte[] out = new byte[ciphertext.length + mac.length];


System.arraycopy(ciphertext, 0, out, 0, ciphertext.length);
System.arraycopy(mac, 0, out, ciphertext.length, mac.length);

MVC Razor Hidden input and passing values

As you may have already figured, Asp.Net MVC is a different paradigm than Asp.Net (webforms). Accessing form elements between the server and client take a different approach in Asp.Net MVC.

You can google more reading material on this on the web. For now, I would suggest using Ajax to get or post data to the server. You can still employ input type="hidden", but initialize it with a value from the ViewData or for Razor, ViewBag.

For example, your controller may look like this:

public ActionResult Index()
{
     ViewBag.MyInitialValue = true;
     return View();
} 

In your view, you can have an input elemet that is initialized by the value in your ViewBag:

<input type="hidden" name="myHiddenInput" id="myHiddenInput" value="@ViewBag.MyInitialValue" />

Then you can pass data between the client and server via ajax. For example, using jQuery:

$.get('GetMyNewValue?oldValue=' + $('#myHiddenInput').val(), function (e) {
   // blah
});

You can alternatively use $.ajax, $.getJSON, $.post depending on your requirement.

Remove Select arrow on IE

In IE9, it is possible with purely a hack as advised by @Spudley. Since you've customized height and width of the div and select, you need to change div:before css to match yours.

In case if it is IE10 then using below css3 it is possible

select::-ms-expand {
    display: none;
}

However if you're interested in jQuery plugin, try Chosen.js or you can create your own in js.

C++ Object Instantiation

Treat heap as a very important real estate and use it very judiciously. The basic thumb rule is to use stack whenever possible and use heap whenever there is no other way. By allocating the objects on stack you can get many benefits such as:

(1). You need not have to worry about stack unwinding in case of exceptions

(2). You need not worry about memory fragmentation caused by the allocating more space than necessary by your heap manager.

Aligning rotated xticklabels with their respective xticks

An easy, loop-free alternative is to use the horizontalalignment Text property as a keyword argument to xticks[1]. In the below, at the commented line, I've forced the xticks alignment to be "right".

n=5
x = np.arange(n)
y = np.sin(np.linspace(-3,3,n))
xlabels = ['Long ticklabel %i' % i for i in range(n)]
fig, ax = plt.subplots()
ax.plot(x,y, 'o-')

plt.xticks(
        [0,1,2,3,4],
        ["this label extends way past the figure's left boundary",
        "bad motorfinger", "green", "in the age of octopus diplomacy", "x"], 
        rotation=45,
        horizontalalignment="right")    # here
plt.show()

(yticks already aligns the right edge with the tick by default, but for xticks the default appears to be "center".)

[1] You find that described in the xticks documentation if you search for the phrase "Text properties".