Programs & Examples On #Zend filter

The zend-filter component provides a set of commonly needed data filters. It also provides a simple filter chaining mechanism by which multiple filters may be applied to a single datum in a user-defined order.

SELECT data from another schema in oracle

Does the user that you are using to connect to the database (user A in this example) have SELECT access on the objects in the PCT schema? Assuming that A does not have this access, you would get the "table or view does not exist" error.

Most likely, you need your DBA to grant user A access to whatever tables in the PCT schema that you need. Something like

GRANT SELECT ON pct.pi_int
   TO a;

Once that is done, you should be able to refer to the objects in the PCT schema using the syntax pct.pi_int as you demonstrated initially in your question. The bracket syntax approach will not work.

How to set a selected option of a dropdown list control using angular JS

Try the following:

JS file

this.options = { 
        languages: [{language: 'English', lg:'en'}, {language:'German', lg:'de'}]
};
console.log(signinDetails.language);

HTML file

<div class="form-group col-sm-6">
    <label>Preferred language</label>
    <select class="form-control" name="right" ng-model="signinDetails.language" ng-init="signinDetails.language = options.languages[0]" ng-options="l as l.language for l in options.languages"><option></option>
    </select>
</div>

What is SOA "in plain english"?

Have a listen to this week's edition of the Floss Weekly podcast, which covers SOA. The descriptions are pretty high level and don't delve into too many technical details (although more concrete and recognizable examples of SOA projects would have been helpful.

Initialize a vector array of strings

In C++0x you will be able to initialize containers just like arrays

http://www2.research.att.com/~bs/C++0xFAQ.html#init-list

Linker Error C++ "undefined reference "

Your error shows you are not compiling file with the definition of the insert function. Update your command to include the file which contains the definition of that function and it should work.

Convert text into number in MySQL query

A generic way to do :

SELECT * FROM your_table ORDER BY LENTH(your_column) ASC, your_column ASC

How to set width and height dynamically using jQuery

or use this syntax:

$("#mainTable").css("width", "100px");
$("#mainTable").css("height", "200px");

What is the difference between %g and %f in C?

As Unwind points out f and g provide different default outputs.

Roughly speaking if you care more about the details of what comes after the decimal point I would do with f and if you want to scale for large numbers go with g. From some dusty memories f is very nice with small values if your printing tables of numbers as everything stays lined up but something like g is needed if you stand a change of your numbers getting large and your layout matters. e is more useful when your numbers tend to be very small or very large but never near ten.

An alternative is to specify the output format so that you get the same number of characters representing your number every time.

Sorry for the woolly answer but it is a subjective out put thing that only gets hard answers if the number of characters generated is important or the precision of the represented value.

Display a float with two decimal places in Python

If you actually want to change the number itself instead of only displaying it differently use format()

Format it to 2 decimal places:

format(value, '.2f')

example:

>>> format(5.00000, '.2f')
'5.00'

Select Pandas rows based on list index

There are many ways of solving this problem, and the ones listed above are the most commonly used ways of achieving the solution. I want to add two more ways, just in case someone is looking for an alternative.

index_list = [1,3]

df.take(pos)

#or

df.query('index in @index_list')

How to print the contents of RDD?

You can convert your RDD to a DataFrame then show() it.

// For implicit conversion from RDD to DataFrame
import spark.implicits._

fruits = sc.parallelize([("apple", 1), ("banana", 2), ("orange", 17)])

// convert to DF then show it
fruits.toDF().show()

This will show the top 20 lines of your data, so the size of your data should not be an issue.

+------+---+                                                                    
|    _1| _2|
+------+---+
| apple|  1|
|banana|  2|
|orange| 17|
+------+---+

Android Material Design Button Styles

I've just created an android library, that allows you to easily modify the button color and the ripple color

https://github.com/xgc1986/RippleButton

<com.xgc1986.ripplebutton.widget.RippleButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/btn"
    android:text="Android button modified in layout"
    android:textColor="@android:color/white"
    app:buttonColor="@android:color/black"
    app:rippleColor="@android:color/white"/>

You don't need to create an style for every button you want wit a different color, allowing you to customize the colors randomly

Promise.all().then() resolve?

Today NodeJS supports new async/await syntax. This is an easy syntax and makes the life much easier

async function process(promises) { // must be an async function
    let x = await Promise.all(promises);  // now x will be an array
    x = x.map( tmp => tmp * 10);              // proccessing the data.
}

const promises = [
   new Promise(resolve => setTimeout(resolve, 0, 1)),
   new Promise(resolve => setTimeout(resolve, 0, 2))
];

process(promises)

Learn more:

How can I check if a JSON is empty in NodeJS?

My solution:

let isEmpty = (val) => {
    let typeOfVal = typeof val;
    switch(typeOfVal){
        case 'object':
            return (val.length == 0) || !Object.keys(val).length;
            break;
        case 'string':
            let str = val.trim();
            return str == '' || str == undefined;
            break;
        case 'number':
            return val == '';
            break;
        default:
            return val == '' || val == undefined;
    }
};
console.log(isEmpty([1,2,4,5])); // false
console.log(isEmpty({id: 1, name: "Trung",age: 29})); // false
console.log(isEmpty('TrunvNV')); // false
console.log(isEmpty(8)); // false
console.log(isEmpty('')); // true
console.log(isEmpty('   ')); // true
console.log(isEmpty([])); // true
console.log(isEmpty({})); // true

Steps to send a https request to a rest service in Node js

Using the request module solved the issue.

// Include the request library for Node.js   
var request = require('request');
//  Basic Authentication credentials   
var username = "vinod"; 
var password = "12345";
var authenticationHeader = "Basic " + new Buffer(username + ":" + password).toString("base64");
request(   
{
url : "https://133-70-97-54-43.sample.com/feedSample/Query_Status_View/Query_Status/Output1?STATUS=Joined%20school",
headers : { "Authorization" : authenticationHeader }  
},
 function (error, response, body) {
 console.log(body); }  );         

System.Drawing.Image to stream C#

Use a memory stream

using(MemoryStream ms = new MemoryStream())
{
    image.Save(ms, ...);
    return ms.ToArray();
}

Reading from memory stream to string

If you'd checked the results of stream.Read, you'd have seen that it hadn't read anything - because you haven't rewound the stream. (You could do this with stream.Position = 0;.) However, it's easier to just call ToArray:

settingsString = LocalEncoding.GetString(stream.ToArray());

(You'll need to change the type of stream from Stream to MemoryStream, but that's okay as it's in the same method where you create it.)

Alternatively - and even more simply - just use StringWriter instead of StreamWriter. You'll need to create a subclass if you want to use UTF-8 instead of UTF-16, but that's pretty easy. See this answer for an example.

I'm concerned by the way you're just catching Exception and assuming that it means something harmless, by the way - without even logging anything. Note that using statements are generally cleaner than writing explicit finally blocks.

How to check if a textbox is empty using javascript

Using this JavaScript will help you a lot. Some explanations are given within the code.

<script type="text/javascript">
    <!-- 
        function Blank_TextField_Validator()
        {
        // Check whether the value of the element 
        // text_name from the form named text_form is null
        if (!text_form.text_name.value)
        {
          // If it is display and alert box
           alert("Please fill in the text field.");
          // Place the cursor on the field for revision
           text_form.text_name.focus();
          // return false to stop further processing
           return (false);
        }
        // If text_name is not null continue processing
        return (true);
        }
        -->
</script>
<form name="text_form" method="get" action="#" 
    onsubmit="return Blank_TextField_Validator()">
    <input type="text" name="text_name" >
    <input type="submit" value="Submit">
</form>

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

Try git fetch --dry-run The manual (git help fetch) says:

--dry-run
Show what would be done, without making any changes.

Default background color of SVG root element

Another workaround might be to use <div> of the same size to wrap the <svg>. After that, you will be able to apply "background-color", and "background-image" that will affect thesvg.

<div class="background">
  <svg></svg>
</div>

<style type="text/css">
.background{
  background-color: black; 
  /*background-image: */
}
</style>

Change PictureBox's image to image from my resources?

Ok...so first you need to import in your project the image

1)Select the picturebox in Form Design

2)Open PictureBox Tasks (it's the little arrow pinted to right on the edge on the picturebox)

3)Click on "Choose image..."

4)Select the second option "Project resource file:" (this option will create a folder called "Resources" which you can acces with Properties.Resources)

5)Click on import and select your image from your computer (now a copy of the image with the same name as the image will be sent in Resources folder created at step 4)

6)Click on ok

Now the image is in your project and you can use it with Properties command.Just type this code when you want to change the picture from picturebox:

pictureBox1.Image = Properties.Resources.myimage;

Note: myimage represent the name of the image...after typing the dot after Resources,in your options it will be your imported image file

Django database query: How to get object by id?

You can also use get_object_or_404 django shortcut. It raises a 404 error if object is not found.

Quickly getting to YYYY-mm-dd HH:MM:SS in Perl

Short and sweet, no additional modules needed:

my $toDate = `date +%m/%d/%Y" "%l:%M:%S" "%p`;

Output for example would be: 04/25/2017 9:30:33 AM

what innerHTML is doing in javascript?

The innerHTML property is used to get or set the HTML content of an element node.

Example: http://jsfiddle.net/mQMVc/

     // get the element with the "someElement" id, and give it new content
document.getElementById('someElement').innerHTML = "<p>new content</p>";

     // retrieve the content from an element
var content = document.getElementById('someElement').innerHTML;

alert( content );

How to set size for local image using knitr for markdown?

The question is old, but still receives a lot of attention. As the existing answers are outdated, here a more up-to-date solution:

Resizing local images

As of knitr 1.12, there is the function include_graphics. From ?include_graphics (emphasis mine):

The major advantage of using this function is that it is portable in the sense that it works for all document formats that knitr supports, so you do not need to think if you have to use, for example, LaTeX or Markdown syntax, to embed an external image. Chunk options related to graphics output that work for normal R plots also work for these images, such as out.width and out.height.

Example:

```{r, out.width = "400px"}
knitr::include_graphics("path/to/image.png")
```

Advantages:

  • Over agastudy's answer: No need for external libraries or for re-rastering the image.
  • Over Shruti Kapoor's answer: No need to manually write HTML. Besides, the image is included in the self-contained version of the file.

Including generated images

To compose the path to a plot that is generated in a chunk (but not included), the chunk options opts_current$get("fig.path") (path to figure directory) as well as opts_current$get("label") (label of current chunk) may be useful. The following example uses fig.path to include the second of two images which were generated (but not displayed) in the first chunk:

```{r generate_figures, fig.show = "hide"}
library(knitr)
plot(1:10, col = "green")
plot(1:10, col = "red")
```

```{r}
include_graphics(sprintf("%sgenerate_figures-2.png", opts_current$get("fig.path")))
```

The general pattern of figure paths is [fig.path]/[chunklabel]-[i].[ext], where chunklabel is the label of the chunk where the plot has been generated, i is the plot index (within this chunk) and ext is the file extension (by default png in RMarkdown documents).

jquery mobile background image

my experience:

in some situations the background image url have to be put separately for all page parts - I use:

var bgImageUrl = "url(../thirdparty/icons/android-circuit.jpg)";

...

$('#indexa').live('pageinit', function() {

   $("#indexa").css("background-image",bgImageUrl);
   $("#contenta").css("background-image",bgImageUrl);
   $("#footera").css("background-image",bgImageUrl);
   ...
}

where "indexa" is the id of the whole page, and the "contenta" and "footera" are id-s of the content and footer respectively.

This works for sure in PhoneGap + jQuery Mobile

Slicing of a NumPy 2d array, or how do I extract an mxm submatrix from an nxn array (n>m)?

To answer this question, we have to look at how indexing a multidimensional array works in Numpy. Let's first say you have the array x from your question. The buffer assigned to x will contain 16 ascending integers from 0 to 15. If you access one element, say x[i,j], NumPy has to figure out the memory location of this element relative to the beginning of the buffer. This is done by calculating in effect i*x.shape[1]+j (and multiplying with the size of an int to get an actual memory offset).

If you extract a subarray by basic slicing like y = x[0:2,0:2], the resulting object will share the underlying buffer with x. But what happens if you acces y[i,j]? NumPy can't use i*y.shape[1]+j to calculate the offset into the array, because the data belonging to y is not consecutive in memory.

NumPy solves this problem by introducing strides. When calculating the memory offset for accessing x[i,j], what is actually calculated is i*x.strides[0]+j*x.strides[1] (and this already includes the factor for the size of an int):

x.strides
(16, 4)

When y is extracted like above, NumPy does not create a new buffer, but it does create a new array object referencing the same buffer (otherwise y would just be equal to x.) The new array object will have a different shape then x and maybe a different starting offset into the buffer, but will share the strides with x (in this case at least):

y.shape
(2,2)
y.strides
(16, 4)

This way, computing the memory offset for y[i,j] will yield the correct result.

But what should NumPy do for something like z=x[[1,3]]? The strides mechanism won't allow correct indexing if the original buffer is used for z. NumPy theoretically could add some more sophisticated mechanism than the strides, but this would make element access relatively expensive, somehow defying the whole idea of an array. In addition, a view wouldn't be a really lightweight object anymore.

This is covered in depth in the NumPy documentation on indexing.

Oh, and nearly forgot about your actual question: Here is how to make the indexing with multiple lists work as expected:

x[[[1],[3]],[1,3]]

This is because the index arrays are broadcasted to a common shape. Of course, for this particular example, you can also make do with basic slicing:

x[1::2, 1::2]

jQuery event handlers always execute in order they were bound - any way around this?

For jQuery 1.9+ as Dunstkreis mentioned .data('events') was removed. But you can use another hack (it is not recommended to use undocumented possibilities) $._data($(this).get(0), 'events') instead and solution provided by anurag will look like:

$.fn.bindFirst = function(name, fn) {
    this.bind(name, fn);
    var handlers = $._data($(this).get(0), 'events')[name.split('.')[0]];
    var handler = handlers.pop();
    handlers.splice(0, 0, handler);
};

"Call to undefined function mysql_connect()" after upgrade to php-7

From the PHP Manual:

Warning This extension was deprecated in PHP 5.5.0, and it was removed in PHP 7.0.0. Instead, the MySQLi or PDO_MySQL extension should be used. See also MySQL: choosing an API guide. Alternatives to this function include:

mysqli_connect()

PDO::__construct()

use MySQLi or PDO

<?php
$con = mysqli_connect('localhost', 'username', 'password', 'database');

How to break lines in PowerShell?

I think I found it. All you have to do is type in "`n" (WITH THE QUOTATION MARKS!)

Thanks!

How to NodeJS require inside TypeScript file?

The correct syntax is:

import sampleModule = require('modulename');

or

import * as sampleModule from 'modulename';

Then compile your TypeScript with --module commonjs.

If the package doesn't come with an index.d.ts file and its package.json doesn't have a "typings" property, tsc will bark that it doesn't know what 'modulename' refers to. For this purpose you need to find a .d.ts file for it on http://definitelytyped.org/, or write one yourself.

If you are writing code for Node.js you will also want the node.d.ts file from http://definitelytyped.org/.

Get Month name from month number

System.Globalization.CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName(4)

This method return April

If you need some special language, you can add:

<system.web>
    <globalization culture="es-ES" uiCulture="es-ES"></globalization>
     <compilation debug="true"
</system.web>

Or your preferred language.

For example, with es-ES culture:

System.Globalization.CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName(4)

Returns: Abril

Returns: Abril (in spanish, because, we configured the culture as es-ES in our webconfig file, else, you will get April)

That should work.

Why and when to use angular.copy? (Deep Copy)

I know its already answered, still i am just trying to make it simple. So angular.copy(data) you can use in case where you want to modify/change your received object by keeping its original values unmodified/unchanged.

For example: suppose i have made api call and got my originalObj, now i want to change the values of api originalObj for some case but i want the original values too so what i can do is, i can make a copy of my api originalObj in duplicateObj and modify duplicateObj this way my originalObj values will not change. In simple words duplicateObj modification will not reflect in originalObj unlike how js obj behave.

 $scope.originalObj={
            fname:'sudarshan',
            country:'India'
        }
        $scope.duplicateObj=angular.copy($scope.originalObj);
        console.log('----------originalObj--------------');
        console.log($scope.originalObj);
        console.log('-----------duplicateObj---------------');
        console.log($scope.duplicateObj);

        $scope.duplicateObj.fname='SUD';
        $scope.duplicateObj.country='USA';
        console.log('---------After update-------')
        console.log('----------originalObj--------------');
        console.log($scope.originalObj);
        console.log('-----------duplicateObj---------------');
        console.log($scope.duplicateObj);

Result is like....

    ----------originalObj--------------
manageProfileController.js:1183 {fname: "sudarshan", country: "India"}
manageProfileController.js:1184 -----------duplicateObj---------------
manageProfileController.js:1185 {fname: "sudarshan", country: "India"}
manageProfileController.js:1189 ---------After update-------
manageProfileController.js:1190 ----------originalObj--------------
manageProfileController.js:1191 {fname: "sudarshan", country: "India"}
manageProfileController.js:1192 -----------duplicateObj---------------
manageProfileController.js:1193 {fname: "SUD", country: "USA"}

angularjs: allows only numbers to be typed into a text box

This is the method that works for me. It's based in samnau anwser but allows to submit the form with ENTER, increase and decrease the number with UP and DOWN arrows, edition with DEL,BACKSPACE,LEFT and RIGHT, and navigate trough fields with TAB. Note that it works for positive integers such as an amount.

HTML:

<input ng-keypress="onlyNumbers($event)" min="0" type="number" step="1" ng-pattern="/^[0-9]{1,8}$/" ng-model="... >

ANGULARJS:

$scope.onlyNumbers = function(event){   
    var keys={
        'up': 38,'right':39,'down':40,'left':37,
        'escape':27,'backspace':8,'tab':9,'enter':13,'del':46,
        '0':48,'1':49,'2':50,'3':51,'4':52,'5':53,'6':54,'7':55,'8':56,'9':57
    };
    for(var index in keys) {
        if (!keys.hasOwnProperty(index)) continue;
        if (event.charCode==keys[index]||event.keyCode==keys[index]) {
            return; //default event
        }
    }   
    event.preventDefault();
};

How to convert comma separated string into numeric array in javascript

All of the given answers so far create a possibly unexpected result for a string like ",1,0,-1,, ,,2":

",1,0,-1,,  ,,2".split(",").map(Number).filter(x => !isNaN(x))
// [0, 1, 0, -1, 0, 0, 0, 2]

To solve this, I've come up with the following fix:

",1,0,-1,,  ,,2".split(',').filter(x => x.trim() !== "").map(Number).filter(x => !isNaN(x))
// [1, 0, -1, 2]

Please note that due to

isNaN("") // false!

and

isNaN(" ") // false

we cannot combine both filter steps.

Can't use modulus on doubles?

You can implement your own modulus function to do that for you:

double dmod(double x, double y) {
    return x - (int)(x/y) * y;
}

Then you can simply use dmod(6.3, 2) to get the remainder, 0.3.

How to replace DOM element in place using Javascript?

var a = A.parentNode.replaceChild(document.createElement("span"), A);

a is the replaced A element.

Differences between Emacs and Vim

Keystroke execution::: vi editing retains each permutation of typed keys. This creates a path in the decision tree which unambiguously identifies any command , whereas Emacs commands are a combination of typed keys executed immediately, which leaves the user with the choice of whether or not to use a command.

Memory usage and customizability::: vi is a smaller and faster program, with a more limited capacity for customization, whereas, Emacs takes longer to start up and requires more memory. However, it is highly customizable and includes a large number of features, as it is essentially an execution environment for a Lisp program designed for text-editing.

Android: How to open a specific folder via Intent and show its content in a file browser?

this code will work with OI File Manager :

        File root = new File(Environment.getExternalStorageDirectory().getPath()
+ "/myFolder/");
        Uri uri = Uri.fromFile(root);

        Intent intent = new Intent();
        intent.setAction(android.content.Intent.ACTION_VIEW);
        intent.setData(uri);
        startActivityForResult(intent, 1);

you can get OI File manager here : http://www.openintents.org/en/filemanager

jQuery DataTables: control table width

Check this solution too. this solved my DataTable column width issue easily

JQuery DataTables 1.10.20 introduces columns.adjust() method which fix Bootstrap toggle tab issue

 $('a[data-toggle="tab"]').on( 'shown.bs.tab', function (e) {
    $.fn.dataTable.tables( {visible: true, api: true} ).columns.adjust();
} );

Please refer the documentation : Scrolling and Bootstrap tabs

How to export plots from matplotlib with transparent background?

Png files can handle transparency. So you could use this question Save plot to image file instead of displaying it using Matplotlib so as to save you graph as a png file.

And if you want to turn all white pixel transparent, there's this other question : Using PIL to make all white pixels transparent?

If you want to turn an entire area to transparent, then there's this question: And then use the PIL library like in this question Python PIL: how to make area transparent in PNG? so as to make your graph transparent.

How to make an "alias" for a long path?

Maybe it's better to use links

Soft Link

Symbolic or soft link (files or directories, more flexible and self documenting)

#      Source                            Link
ln -s /home/jake/doc/test/2000/something /home/jake/xxx

Hard Link

Hard link (files only, less flexible and not self documenting)

#    Source                            Link
ln /home/jake/doc/test/2000/something /home/jake/xxx

How to create a link to a directory

Hint: If you need not to see the link in your home you can start it with a dot . ; then it will be hidden by default then you can access it like

cd ~/.myHiddelLongDirLink

What is the difference between __dirname and ./ in node.js?

The gist

In Node.js, __dirname is always the directory in which the currently executing script resides (see this). So if you typed __dirname into /d1/d2/myscript.js, the value would be /d1/d2.

By contrast, . gives you the directory from which you ran the node command in your terminal window (i.e. your working directory) when you use libraries like path and fs. Technically, it starts out as your working directory but can be changed using process.chdir().

The exception is when you use . with require(). The path inside require is always relative to the file containing the call to require.

For example...

Let's say your directory structure is

/dir1
  /dir2
    pathtest.js

and pathtest.js contains

var path = require("path");
console.log(". = %s", path.resolve("."));
console.log("__dirname = %s", path.resolve(__dirname));

and you do

cd /dir1/dir2
node pathtest.js

you get

. = /dir1/dir2
__dirname = /dir1/dir2

Your working directory is /dir1/dir2 so that's what . resolves to. Since pathtest.js is located in /dir1/dir2 that's what __dirname resolves to as well.

However, if you run the script from /dir1

cd /dir1
node dir2/pathtest.js

you get

. = /dir1
__dirname = /dir1/dir2

In that case, your working directory was /dir1 so that's what . resolved to, but __dirname still resolves to /dir1/dir2.

Using . inside require...

If inside dir2/pathtest.js you have a require call into include a file inside dir1 you would always do

require('../thefile')

because the path inside require is always relative to the file in which you are calling it. It has nothing to do with your working directory.

Center an item with position: relative

Much simpler:

position: relative; 
left: 50%;
transform: translateX(-50%);

You are now centered in your parent element. You can do that vertically too.

How is __eq__ handled in Python and in what order?

The a == b expression invokes A.__eq__, since it exists. Its code includes self.value == other. Since int's don't know how to compare themselves to B's, Python tries invoking B.__eq__ to see if it knows how to compare itself to an int.

If you amend your code to show what values are being compared:

class A(object):
    def __eq__(self, other):
        print("A __eq__ called: %r == %r ?" % (self, other))
        return self.value == other
class B(object):
    def __eq__(self, other):
        print("B __eq__ called: %r == %r ?" % (self, other))
        return self.value == other

a = A()
a.value = 3
b = B()
b.value = 4
a == b

it will print:

A __eq__ called: <__main__.A object at 0x013BA070> == <__main__.B object at 0x013BA090> ?
B __eq__ called: <__main__.B object at 0x013BA090> == 3 ?

Uncaught TypeError: $(...).datepicker is not a function(anonymous function)

This error is occur,because the function is not defined. In my case i have called the datepicker function without including the datepicker js file that time I got this error.

The most efficient way to implement an integer based power function pow(int, int)

My case is a little different, I'm trying to create a mask from a power, but I thought I'd share the solution I found anyway.

Obviously, it only works for powers of 2.

Mask1 = 1 << (Exponent - 1);
Mask2 = Mask1 - 1;
return Mask1 + Mask2;

Oracle's default date format is YYYY-MM-DD, WHY?

A DATE value per the SQL standard is YYYY-MM-DD. So even though Oracle stores the time information, my guess is that they're displaying the value in a way that is compatible with the SQL standard. In the standard, there is the TIMESTAMP data type that includes date and time info.

WebAPI to Return XML

If you don't want the controller to decide the return object type, you should set your method return type as System.Net.Http.HttpResponseMessage and use the below code to return the XML.

public HttpResponseMessage Authenticate()
{
  //process the request 
  .........

  string XML="<note><body>Message content</body></note>";
  return new HttpResponseMessage() 
  { 
    Content = new StringContent(XML, Encoding.UTF8, "application/xml") 
  };
}

This is the quickest way to always return XML from Web API.

Can I change the height of an image in CSS :before/:after pseudo-elements?

Adjusting the background-size is permitted. You still need to specify width and height of the block, however.

.pdflink:after {
    background-image: url('/images/pdf.png');
    background-size: 10px 20px;
    display: inline-block;
    width: 10px; 
    height: 20px;
    content:"";
}

See the full Compatibility Table at the MDN.

ReactJS call parent method

2019 Update with react 16+ and ES6

Posting this since React.createClass is deprecated from react version 16 and the new Javascript ES6 will give you more benefits.

Parent

import React, {Component} from 'react';
import Child from './Child';
  
export default class Parent extends Component {

  es6Function = (value) => {
    console.log(value)
  }

  simplifiedFunction (value) {
    console.log(value)
  }

  render () {
  return (
    <div>
    <Child
          es6Function = {this.es6Function}
          simplifiedFunction = {this.simplifiedFunction} 
        />
    </div>
    )
  }

}

Child

import React, {Component} from 'react';

export default class Child extends Component {

  render () {
  return (
    <div>
    <h1 onClick= { () =>
            this.props.simplifiedFunction(<SomethingThatYouWantToPassIn>)
          }
        > Something</h1>
    </div>
    )
  }
}

Simplified stateless child as ES6 constant

import React from 'react';

const Child = () => {
  return (
    <div>
    <h1 onClick= { () =>
        this.props.es6Function(<SomethingThatYouWantToPassIn>)
      }
      > Something</h1>
    </div>
  )

}
export default Child;

Style disabled button with CSS

When your button is disabled it directly sets the opacity. So first of all we have to set its opacity as

.v-button{
    opacity:1;    
}

SQL Add foreign key to existing column

If the table has already been created:

First do:

ALTER TABLE `table1_name` ADD UNIQUE( `column_name`);

Then:

ALTER TABLE `table1_name` ADD FOREIGN KEY (`column_name`) REFERENCES `table2_name`(`column_name`);

is python capable of running on multiple cores?

I converted the script to Python3 and ran it on my Raspberry Pi 3B+:

import time
import threading

def t():
        with open('/dev/urandom', 'rb') as f:
                for x in range(100):
                        f.read(4 * 65535)

if __name__ == '__main__':
    start_time = time.time()
    t()
    t()
    t()
    t()
    print("Sequential run time: %.2f seconds" % (time.time() - start_time))

    start_time = time.time()
    t1 = threading.Thread(target=t)
    t2 = threading.Thread(target=t)
    t3 = threading.Thread(target=t)
    t4 = threading.Thread(target=t)
    t1.start()
    t2.start()
    t3.start()
    t4.start()
    t1.join()
    t2.join()
    t3.join()
    t4.join()
    print("Parallel run time: %.2f seconds" % (time.time() - start_time))

python3 t.py

Sequential run time: 2.10 seconds
Parallel run time: 1.41 seconds

For me, running parallel was quicker.

iOS Detection of Screenshot?

Latest SWIFT 3:

func detectScreenShot(action: @escaping () -> ()) {
        let mainQueue = OperationQueue.main
        NotificationCenter.default.addObserver(forName: .UIApplicationUserDidTakeScreenshot, object: nil, queue: mainQueue) { notification in
            // executes after screenshot
            action()
        }
    }

In viewDidLoad, call this function

detectScreenShot { () -> () in
 print("User took a screen shot")
}

However,

NotificationCenter.default.addObserver(self, selector: #selector(test), name: .UIApplicationUserDidTakeScreenshot, object: nil)

    func test() {
    //do stuff here
    }

works totally fine. I don't see any points of mainQueue...

Install gitk on Mac

I had the same issue. I installed gitx instead.

You can install gitx from here.

http://rowanj.github.io/gitx/

Download the package and install it. After that open the gitk from spotlight search, goto the top left corner. Click on GitX and enable the terminal usage.

Goto your repo and simply type:

$ gitx --all

It will open the Gui.

User manual: http://gitx.frim.nl/user_manual.html

How to go from Blob to ArrayBuffer

There is now (Chrome 76+ & FF 69+) a Blob.prototype.arrayBuffer() method which will return a Promise resolving with an ArrayBuffer representing the Blob's data.

_x000D_
_x000D_
(async () => {_x000D_
  const blob = new Blob(['hello']);_x000D_
  const buf = await blob.arrayBuffer();_x000D_
  console.log( buf.byteLength ); // 5_x000D_
})();
_x000D_
_x000D_
_x000D_

How do you get the footer to stay at the bottom of a Web page?

jQuery CROSS BROWSER CUSTOM PLUGIN - $.footerBottom()

Or use jQuery like I do, and set your footer height to auto or to fix, whatever you like, it will work anyway. this plugin uses jQuery selectors so to make it work, you will have to include the jQuery library to your file.

Here is how you run the plugin. Import jQuery, copy the code of this custom jQuery plugin and import it after importing jQuery! It is very simple and basic, but important.

When you do it, all you have to do is run this code:

$.footerBottom({target:"footer"}); //as html5 tag <footer>.
// You can change it to your preferred "div" with for example class "footer" 
// by setting target to {target:"div.footer"}

there is no need to place it inside the document ready event. It will run well as it is. It will recalculate the position of your footer when the page is loaded and when the window get resized.

Here is the code of the plugin which you do not have to understand. Just know how to implement it. It does the job for you. However, if you like to know how it works, just look through the code. I left comments for you.

//import jQuery library before this script

_x000D_
_x000D_
// Import jQuery library before this script_x000D_
_x000D_
// Our custom jQuery Plugin_x000D_
(function($) {_x000D_
  $.footerBottom = function(options) { // Or use "$.fn.footerBottom" or "$.footerBottom" to call it globally directly from $.footerBottom();_x000D_
    var defaults = {_x000D_
      target: "footer",_x000D_
      container: "html",_x000D_
      innercontainer: "body",_x000D_
      css: {_x000D_
        footer: {_x000D_
          position: "absolute",_x000D_
          left: 0,_x000D_
          bottom: 0,_x000D_
        },_x000D_
_x000D_
        html: {_x000D_
          position: "relative",_x000D_
          minHeight: "100%"_x000D_
        }_x000D_
      }_x000D_
    };_x000D_
_x000D_
    options = $.extend(defaults, options);_x000D_
_x000D_
    // JUST SET SOME CSS DEFINED IN THE DEFAULTS SETTINGS ABOVE_x000D_
    $(options.target).css({_x000D_
      "position": options.css.footer.position,_x000D_
      "left": options.css.footer.left,_x000D_
      "bottom": options.css.footer.bottom,_x000D_
    });_x000D_
_x000D_
    $(options.container).css({_x000D_
      "position": options.css.html.position,_x000D_
      "min-height": options.css.html.minHeight,_x000D_
    });_x000D_
_x000D_
    function logic() {_x000D_
      var footerOuterHeight = $(options.target).outerHeight(); // Get outer footer height_x000D_
      $(options.innercontainer).css('padding-bottom', footerOuterHeight + "px"); // Set padding equal to footer height on body element_x000D_
      $(options.target).css('height', footerOuterHeight + "!important"); // Set outerHeight of footer element to ... footer_x000D_
      console.log("jQ custom plugin footerBottom runs"); // Display text in console so ou can check that it works in your browser. Delete it if you like._x000D_
    };_x000D_
_x000D_
    // DEFINE WHEN TO RUN FUNCTION_x000D_
    $(window).on('load resize', function() { // Run on page loaded and on window resized_x000D_
      logic();_x000D_
    });_x000D_
_x000D_
    // RETURN OBJECT FOR CHAINING IF NEEDED - IF NOT DELETE_x000D_
    // return this.each(function() {_x000D_
    //   this.checked = true;_x000D_
    // });_x000D_
    // return this;_x000D_
  };_x000D_
})(jQuery); // End of plugin_x000D_
_x000D_
_x000D_
// USE EXAMPLE_x000D_
$.footerBottom(); // Run our plugin with all default settings for HTML5
_x000D_
/* Set your footer CSS to what ever you like it will work anyway */_x000D_
footer {_x000D_
  box-sizing: border-box;_x000D_
  height: auto;_x000D_
  width: 100%;_x000D_
  padding: 30px 0;_x000D_
  background-color: black;_x000D_
  color: white;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
_x000D_
<!-- The structure doesn't matter much, you will always have html and body tag, so just make sure to point to your footer as needed if you use html5, as it should just do nothing run plugin with no settings it will work by default with the <footer> html5 tag -->_x000D_
<body>_x000D_
  <div class="content">_x000D_
  <header>_x000D_
    <nav>_x000D_
      <ul>_x000D_
        <li>link</li>_x000D_
        <li>link</li>_x000D_
        <li>link</li>_x000D_
        <li>link</li>_x000D_
        <li>link</li>_x000D_
        <li>link</li>_x000D_
      </ul>_x000D_
    </nav>_x000D_
  </header>_x000D_
_x000D_
  <section>_x000D_
      <p></p>_x000D_
      <p>Lorem ipsum...</p>_x000D_
    </section>_x000D_
  </div>_x000D_
  <footer>_x000D_
    <p>Copyright 2009 Your name</p>_x000D_
    <p>Copyright 2009 Your name</p>_x000D_
    <p>Copyright 2009 Your name</p>_x000D_
  </footer>
_x000D_
_x000D_
_x000D_

JavaScript to get rows count of a HTML table

If the table has an ID:

const tableObject = document.getElementById(tableId);
const rowCount = tableObject[1].childElementCount;

If the table has a Class:

const tableObject = document.getElementsByClassName(tableClass);
const rowCount = tableObject[1].childElementCount;

If the table has a Name:

const tableObject = document.getElementsByTagName('table');
const rowCount = tableObject[1].childElementCount;

Note: index 1 represents <tbody> tag

Error:Execution failed for task ':app:processDebugResources'. > java.io.IOException: Could not delete folder "" in android studio

In my case, that problem is about permissions. if you open android studio as administrator (or using sudo) then if you open the project again as normal user, android studio may not delete some files because when you open the project as administrator, some project files permissions are changed. If you lived those steps, I think you should clone the project from your VCS (git, tfs, svn etc.) again. Otherwise you have to configure project file - folder permissions.

MySql sum elements of a column

select
  sum(a) as atotal,
  sum(b) as btotal,
  sum(c) as ctotal
from
  yourtable t
where
  t.id in (1, 2, 3)

Can a background image be larger than the div itself?

Use trasform: scale(1.1) property to make bg image bigger, move it up with position: relative; top: -10px;

<div class="home-hero">
    <div class="home-hero__img"></div>
</div>

.home-hero__img{
 position:relative;
    top:-10px;
    transform: scale(1.1);
    background: {
        size: contain;
        image: url('image.svg');
    }
}

Use string contains function in oracle SQL query

By lines I assume you mean rows in the table person. What you're looking for is:

select p.name
from   person p
where  p.name LIKE '%A%'; --contains the character 'A'

The above is case sensitive. For a case insensitive search, you can do:

select p.name
from   person p
where  UPPER(p.name) LIKE '%A%'; --contains the character 'A' or 'a'

For the special character, you can do:

select p.name
from   person p
where  p.name LIKE '%'||chr(8211)||'%'; --contains the character chr(8211)

The LIKE operator matches a pattern. The syntax of this command is described in detail in the Oracle documentation. You will mostly use the % sign as it means match zero or more characters.

How can I reference a dll in the GAC from Visual Studio?

Assuming you alredy tried to "Add Reference..." as explained above and did not succeed, you can have a look here. They say you have to meet some prerequisites: - .NET 3.5 SP1 - Windows Installer 4.5

EDIT: According to this post it is a known issue.

And this could be the solution you're looking for :)

How do I define a method in Razor?

You can also just use the @{ } block to create functions:

@{
    async Task<string> MyAsyncString(string input)
    {
        return Task.FromResult(input);
    }
}

Then later in your razor page:

   <div>@(await MyAsyncString("weee").ConfigureAwait(false))</div>

Starting iPhone app development in Linux?

To a certain extent, yes, it is possible. You can type Objective-C code and set up your projects. You can even test the C and C++ parts of your code with gcc.

What you cannot do:

  • Use Interface Builder to set up your interface, as it's Mac-only. (Not required, but recommended.)
  • Compile code that uses Apple's Cocoa classes - they don't exist on Linux.
  • Test code in the Simulator - there isn't one for Linux.
  • Compile code for real devices or for the App Store - all this requires tools that Apple only provides for OS X.

How to find the UpgradeCode and ProductCode of an installed application in Windows 7

If anyone wants to get installed application package code, just execute below command with your application name in the command prompt. You will be getting product code along with package code.

wmic product where "Name like '%YOUR_APPLICATION_NAME%'" get IdentifyingNumber, PackageCode

How to stick table header(thead) on top while scrolling down the table rows with fixed header(navbar) in bootstrap 3?

This can now be done without JS, just pure CSS. So, anyone trying to do this for modern browsers should look into using position: sticky instead.

Currently, both Edge and Chrome have a bug where position: sticky doesn't work on thead or tr elements, however it's possible to use it on th elements, so all you need to do is just add this to your code:

th {
  position: sticky;
  top: 50px;  /* 0px if you don't have a navbar, but something is required */
  background: white;
}

Note: you'll need a background color for them, or you'll be able to see through the sticky title bar.

This has very good browser support.

Demo with your code (HTML unaltered, above 5 lines of CSS added, all JS removed):

_x000D_
_x000D_
body {_x000D_
    padding-top:50px;_x000D_
}_x000D_
table.floatThead-table {_x000D_
    border-top: none;_x000D_
    border-bottom: none;_x000D_
    background-color: #fff;_x000D_
}_x000D_
_x000D_
th {_x000D_
  position: sticky;_x000D_
  top: 50px;_x000D_
  background: white;_x000D_
}
_x000D_
<link rel="stylesheet" type="text/css" href="//netdna.bootstrapcdn.com/bootstrap/3.0.0/css/bootstrap.min.css">_x000D_
_x000D_
<!-- Fixed navbar -->_x000D_
<div class="navbar navbar-default navbar-fixed-top">_x000D_
    <div class="container">_x000D_
        <div class="navbar-header">_x000D_
            <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse"> <span class="icon-bar"></span>_x000D_
 <span class="icon-bar"></span>_x000D_
 <span class="icon-bar"></span>_x000D_
_x000D_
            </button> <a class="navbar-brand" href="#">Project name</a>_x000D_
_x000D_
        </div>_x000D_
        <div class="collapse navbar-collapse">_x000D_
            <ul class="nav navbar-nav">_x000D_
                <li class="active"><a href="#">Home</a>_x000D_
_x000D_
                </li>_x000D_
                <li><a href="#about">About</a>_x000D_
_x000D_
                </li>_x000D_
                <li><a href="#contact">Contact</a>_x000D_
_x000D_
                </li>_x000D_
                <li class="dropdown"> <a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown <b class="caret"></b></a>_x000D_
_x000D_
                    <ul class="dropdown-menu">_x000D_
                        <li><a href="#">Action</a>_x000D_
_x000D_
                        </li>_x000D_
                        <li><a href="#">Another action</a>_x000D_
_x000D_
                        </li>_x000D_
                        <li><a href="#">Something else here</a>_x000D_
_x000D_
                        </li>_x000D_
                        <li class="divider"></li>_x000D_
                        <li class="dropdown-header">Nav header</li>_x000D_
                        <li><a href="#">Separated link</a>_x000D_
_x000D_
                        </li>_x000D_
                        <li><a href="#">One more separated link</a>_x000D_
_x000D_
                        </li>_x000D_
                    </ul>_x000D_
                </li>_x000D_
            </ul>_x000D_
        </div>_x000D_
        <!--/.nav-collapse -->_x000D_
    </div>_x000D_
</div>_x000D_
<!-- Begin page content -->_x000D_
<div class="container">_x000D_
    <div class="page-header">_x000D_
         <h1>Sticky Table Headers</h1>_x000D_
_x000D_
    </div>_x000D_
    <p class="lead">If the page is tall and all of the table is visible, then it won't stick. Make your viewport short.</p>_x000D_
    <p class="lead">If the page is tall and all of the table is visible, then it won't stick. Make your viewport short.</p>_x000D_
    <p class="lead">If the page is tall and all of the table is visible, then it won't stick. Make your viewport short.</p>_x000D_
    <table class="table table-striped sticky-header">_x000D_
        <thead>_x000D_
            <tr>_x000D_
                <th>#</th>_x000D_
                <th>First Name</th>_x000D_
                <th>Last Name</th>_x000D_
                <th>Username</th>_x000D_
            </tr>_x000D_
        </thead>_x000D_
        <tbody>_x000D_
            <tr>_x000D_
                <td>1</td>_x000D_
                <td>Mark</td>_x000D_
                <td>Otto</td>_x000D_
                <td>@mdo</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>2</td>_x000D_
                <td>Jacob</td>_x000D_
                <td>Thornton</td>_x000D_
                <td>@fat</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>3</td>_x000D_
                <td>Larry</td>_x000D_
                <td>the Bird</td>_x000D_
                <td>@twitter</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>1</td>_x000D_
                <td>Mark</td>_x000D_
                <td>Otto</td>_x000D_
                <td>@mdo</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>2</td>_x000D_
                <td>Jacob</td>_x000D_
                <td>Thornton</td>_x000D_
                <td>@fat</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>3</td>_x000D_
                <td>Larry</td>_x000D_
                <td>the Bird</td>_x000D_
                <td>@twitter</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>1</td>_x000D_
                <td>Mark</td>_x000D_
                <td>Otto</td>_x000D_
                <td>@mdo</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>2</td>_x000D_
                <td>Jacob</td>_x000D_
                <td>Thornton</td>_x000D_
                <td>@fat</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>3</td>_x000D_
                <td>Larry</td>_x000D_
                <td>the Bird</td>_x000D_
                <td>@twitter</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>1</td>_x000D_
                <td>Mark</td>_x000D_
                <td>Otto</td>_x000D_
                <td>@mdo</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>2</td>_x000D_
                <td>Jacob</td>_x000D_
                <td>Thornton</td>_x000D_
                <td>@fat</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>3</td>_x000D_
                <td>Larry</td>_x000D_
                <td>the Bird</td>_x000D_
                <td>@twitter</td>_x000D_
            </tr>_x000D_
        </tbody>_x000D_
    </table>_x000D_
    <p class="lead">If the page is tall and all of the table is visible, then it won't stick. Make your viewport short.</p>_x000D_
    <p class="lead">If the page is tall and all of the table is visible, then it won't stick. Make your viewport short.</p>_x000D_
    <p class="lead">If the page is tall and all of the table is visible, then it won't stick. Make your viewport short.</p>_x000D_
    <p class="lead">If the page is tall and all of the table is visible, then it won't stick. Make your viewport short.</p>_x000D_
    <p class="lead">If the page is tall and all of the table is visible, then it won't stick. Make your viewport short.</p>_x000D_
    <p class="lead">If the page is tall and all of the table is visible, then it won't stick. Make your viewport short.</p>_x000D_
    <p class="lead">If the page is tall and all of the table is visible, then it won't stick. Make your viewport short.</p>_x000D_
     <h3>Table 2</h3>_x000D_
_x000D_
    <table class="table table-striped sticky-header">_x000D_
        <thead>_x000D_
            <tr>_x000D_
                <th>#</th>_x000D_
                <th>New Table</th>_x000D_
                <th>Last Name</th>_x000D_
                <th>Username</th>_x000D_
            </tr>_x000D_
        </thead>_x000D_
        <tbody>_x000D_
            <tr>_x000D_
                <td>1</td>_x000D_
                <td>Mark</td>_x000D_
                <td>Otto</td>_x000D_
                <td>@mdo</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>2</td>_x000D_
                <td>Jacob</td>_x000D_
                <td>Thornton</td>_x000D_
                <td>@fat</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>3</td>_x000D_
                <td>Larry</td>_x000D_
                <td>the Bird</td>_x000D_
                <td>@twitter</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>1</td>_x000D_
                <td>Mark</td>_x000D_
                <td>Otto</td>_x000D_
                <td>@mdo</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>2</td>_x000D_
                <td>Jacob</td>_x000D_
                <td>Thornton</td>_x000D_
                <td>@fat</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>3</td>_x000D_
                <td>Larry</td>_x000D_
                <td>the Bird</td>_x000D_
                <td>@twitter</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>1</td>_x000D_
                <td>Mark</td>_x000D_
                <td>Otto</td>_x000D_
                <td>@mdo</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>2</td>_x000D_
                <td>Jacob</td>_x000D_
                <td>Thornton</td>_x000D_
                <td>@fat</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>3</td>_x000D_
                <td>Larry</td>_x000D_
                <td>the Bird</td>_x000D_
                <td>@twitter</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>1</td>_x000D_
                <td>Mark</td>_x000D_
                <td>Otto</td>_x000D_
                <td>@mdo</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>2</td>_x000D_
                <td>Jacob</td>_x000D_
                <td>Thornton</td>_x000D_
                <td>@fat</td>_x000D_
            </tr>_x000D_
            <tr>_x000D_
                <td>3</td>_x000D_
                <td>Larry</td>_x000D_
                <td>the Bird</td>_x000D_
                <td>@twitter</td>_x000D_
            </tr>_x000D_
        </tbody>_x000D_
    </table>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to synchronize or lock upon variables in Java?

If on another occasion you're synchronising a Collection rather than a String, perhaps you're be iterating over the collection and are worried about it mutating, Java 5 offers:

Android Studio - How to Change Android SDK Path

I had the same problem, but with the sdk path pointing to a mounted drive. I found, that simply quit Android Studio, unmount the device and restart Android Studio made it ask for the sdk location, because it had none (Android Studio Beta 0.8.7).

Therefore I guess if you just quit Android Studio, delete \android-studio\sdk or move it somewhere else and start Android Studio again, it should ask for the sdk location aswell.

Is it possible only to declare a variable without assigning any value in Python?

You can trick an interpreter with this ugly oneliner if None: var = None It do nothing else but adding a variable var to local variable dictionary, not initializing it. Interpreter will throw the UnboundLocalError exception if you try to use this variable in a function afterwards. This would works for very ancient python versions too. Not simple, nor beautiful, but don't expect much from python.

Call PowerShell script PS1 from another PS1 script inside Powershell ISE

How do you run PowerShell built-in scripts inside of your scripts?

How do you use built-in scripts like

Get-Location
pwd
ls
dir
split-path
::etc...

Those are ran by your computer, automatically checking the path of the script.

Similarly, I can run my custom scripts by just putting the name of the script in the script-block

::sid.ps1 is a PS script I made to find the SID of any user
::it takes one argument, that argument would be the username
echo $(sid.ps1 jowers)


(returns something like)> S-X-X-XXXXXXXX-XXXXXXXXXX-XXX-XXXX


$(sid.ps1 jowers).Replace("S","X")

(returns same as above but with X instead of S)

Go on to the powershell command line and type

> $profile

This will return the path to a file that our PowerShell command line will execute every time you open the app.

It will look like this

C:\Users\jowers\OneDrive\Documents\WindowsPowerShell\Microsoft.PowerShellISE_profile.ps1

Go to Documents and see if you already have a WindowsPowerShell directory. I didn't, so

> cd \Users\jowers\Documents
> mkdir WindowsPowerShell
> cd WindowsPowerShell
> type file > Microsoft.PowerShellISE_profile.ps1

We've now created the script that will launch every time we open the PowerShell App.

The reason we did that was so that we could add our own folder that holds all of our custom scripts. Let's create that folder and I'll name it "Bin" after the directories that Mac/Linux hold its scripts in.

> mkdir \Users\jowers\Bin

Now we want that directory to be added to our $env:path variable every time we open the app so go back to the WindowsPowerShell Directory and

> start Microsoft.PowerShellISE_profile.ps1

Then add this

$env:path += ";\Users\jowers\Bin"

Now the shell will automatically find your commands, as long as you save your scripts in that "Bin" directory.

Relaunch the powershell and it should be one of the first scripts that execute.

Run this on the command line after reloading to see your new directory in your path variable:

> $env:Path

Now we can call our scripts from the command line or from within another script as simply as this:

$(customScript.ps1 arg1 arg2 ...)

As you see we must call them with the .ps1 extension until we make aliases for them. If we want to get fancy.

jQuery calculate sum of values in all text fields

?

$('.price').blur(function () {
    var sum = 0;
    $('.price').each(function() {
        sum += Number($(this).val());
    });

    // here, you have your sum
});?????????

Convert timestamp to string

try this

SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy HH:mm:ss");
String string  = dateFormat.format(new Date());
System.out.println(string);

you can create any format see this

SQL Server: Filter output of sp_who2

based on http://web.archive.org/web/20080218124946/http://sqlserver2005.databases.aspfaq.com/how-do-i-mimic-sp-who2.html

i have created following script ,
which resolves finding active connections to any datbase using DMV this works under sql 2005 , 2008 and 2008R2

Following script uses sys.dm_exec_sessions , sys.dm_exec_requests , sys.dm_exec_connections , sys.dm_tran_locks

Declare @dbName varchar(1000)
set @dbName='abc'

;WITH DBConn(SPID,[Status],[Login],HostName,DBName,Command,LastBatch,ProgramName)
As
(
SELECT 
    SPID = s.session_id,
    Status = UPPER(COALESCE
        (
            r.status,
            ot.task_state,
            s.status, 
        '')),
    [Login] = s.login_name,
    HostName = COALESCE
        (
            s.[host_name],
            '  .'
        ),
    DBName = COALESCE
        (
            DB_NAME(COALESCE
            (
                r.database_id,
                t.database_id
            )),
            ''
        ),
    Command = COALESCE
        (
            r.Command,
            r.wait_type,
            wt.wait_type,
            r.last_wait_type,
            ''
        ),
    LastBatch = COALESCE
        (
            r.start_time,
            s.last_request_start_time
        ),
    ProgramName = COALESCE
        (
            s.program_name, 
            ''
        )
FROM
    sys.dm_exec_sessions s
LEFT OUTER JOIN
    sys.dm_exec_requests r
ON
    s.session_id = r.session_id
LEFT OUTER JOIN
    sys.dm_exec_connections c
ON
    s.session_id = c.session_id
LEFT OUTER JOIN
(
    SELECT 
        request_session_id,
        database_id = MAX(resource_database_id)
    FROM
        sys.dm_tran_locks
    GROUP BY
        request_session_id
) t
ON
    s.session_id = t.request_session_id
LEFT OUTER JOIN
    sys.dm_os_waiting_tasks wt
ON 
    s.session_id = wt.session_id
LEFT OUTER JOIN
    sys.dm_os_tasks ot
ON 
    s.session_id = ot.session_id
LEFT OUTER JOIN
(
    SELECT
        ot.session_id,
        CPU_Time = MAX(usermode_time)
    FROM
        sys.dm_os_tasks ot
    INNER JOIN
        sys.dm_os_workers ow
    ON
        ot.worker_address = ow.worker_address
    INNER JOIN
        sys.dm_os_threads oth
    ON
        ow.thread_address = oth.thread_address
    GROUP BY
        ot.session_id
) tt
ON
    s.session_id = tt.session_id
WHERE
    COALESCE
    (
        r.command,
        r.wait_type,
        wt.wait_type,
        r.last_wait_type,
        'a'
    ) >= COALESCE
    (
        '', 
        'a'
    )
)

Select * from DBConn
where DBName like '%'+@dbName+'%'

smooth scroll to top

Came up with this solution:

function scrollToTop() {
let currentOffset = window.pageYOffset;
const arr = [];

for (let i = 100; i >= 0; i--) {
    arr.push(new Promise(res => {
            setTimeout(() => {
                    res(currentOffset * (i / 100));
                },
                2 * (100 - i))
        })
    );
}

arr.reduce((acc, curr, index, arr) => {
    return acc.then((res) => {
        if (typeof res === 'number')
            window.scrollTo(0, res)
        return curr
    })
}, Promise.resolve(currentOffset)).then(() => {
    window.scrollTo(0, 0)
})}

How to change color of Android ListView separator line?

XML version for @Asher Aslan cool effect.

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" >

    <gradient
        android:angle="180"
        android:startColor="#00000000"
        android:centerColor="#FFFF0000"
        android:endColor="#00000000"/>

</shape>

Name for that shape as: list_driver.xml under drawable folder

<ListView
        android:id="@+id/category_list"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" 
        android:divider="@drawable/list_driver"
        android:dividerHeight="5sp" />

How can we redirect a Java program console output to multiple files?

You can set the output of System.out programmatically by doing:

System.setOut(new PrintStream(new BufferedOutputStream(new FileOutputStream("/location/to/console.out")), true));

Edit:

Due to the fact that this solution is based on a PrintStream, we can enable autoFlush, but according to the docs:

autoFlush - A boolean; if true, the output buffer will be flushed whenever a byte array is written, one of the println methods is invoked, or a newline character or byte ('\n') is written

So if a new line isn't written, remember to System.out.flush() manually.

(Thanks Robert Tupelo-Schneck)

Pass a variable to a PHP script running from the command line

Just pass it as normal parameters and access it in PHP using the $argv array.

php myfile.php daily

and in myfile.php

$type = $argv[1];

Double array initialization in Java

double m[][] declares an array of arrays, so called multidimensional array.

m[0] points to an array in the size of four, containing 0*0,1*0,2*0,3*0. Simple math shows the values are actually 0,0,0,0.

Second line is also array in the size of four, containing 0,1,2,3.

And so on...

I guess this mutiple format in you book was to show that 0*0 is row 0 column 0, 0*1 is row 0 column 1, and so on.

Adding a rule in iptables in debian to open a new port

(I presume that you've concluded that it's an iptables problem by dropping the firewall completely (iptables -P INPUT ACCEPT; iptables -P OUTPUT ACCEPT; iptables -F) and confirmed that you can connect to the MySQL server from your Windows box?)

Some previous rule in the INPUT table is probably rejecting or dropping the packet. You can get around that by inserting the new rule at the top, although you might want to review your existing rules to see whether that's sensible:

iptables -I INPUT 1 -p tcp --dport 3306 -j ACCEPT

Note that iptables-save won't save the new rule persistently (i.e. across reboots) - you'll need to figure out something else for that. My usual route is to store the iptables-save output in a file (/etc/network/iptables.rules or similar) and then load then with a pre-up statement in /etc/network/interfaces).

How to use sed to replace only the first occurrence in a file?

i would do this with an awk script:

BEGIN {i=0}
(i==0) && /#include/ {print "#include \"newfile.h\""; i=1}
{print $0}    
END {}

then run it with awk:

awk -f awkscript headerfile.h > headerfilenew.h

might be sloppy, I'm new to this.

Group query results by month and year in postgresql

There is another way to achieve the result using the date_part() function in postgres.

 SELECT date_part('month', txn_date) AS txn_month, date_part('year', txn_date) AS txn_year, sum(amount) as monthly_sum
     FROM yourtable
 GROUP BY date_part('month', txn_date)

Thanks

How do I run a shell script without using "sh" or "bash" commands?

These are the prerequisites of directly using the script name:

  1. Add the shebang line (#!/bin/bash) at the very top.
  2. Use chmod u+x scriptname to make the script executable (where scriptname is the name of your script).
  3. Place the script under /usr/local/bin folder.
    • Note: I suggest placing it under /usr/local/bin because most likely that path will be already added to your PATH variable.
  4. Run the script using just its name, scriptname.

If you don't have access to /usr/local/bin then do the following:

  1. Create a folder in your home directory and call it bin.

  2. Do ls -lA on your home directory, to identify the start-up script your shell is using. It should be either .profile or .bashrc.

  3. Once you have identified the start up script, add the following line:

    PATH="$PATH:$HOME/bin"
    
  4. Once added, source your start-up script or log out and log back in.

    To source, put . followed by a space and then your start-up script name, e.g. . .profile or . .bashrc

  5. Run the script using just its name, scriptname.

How to Convert an int to a String?

may be you should try like this

int sdRate=5;
//text_Rate is a TextView
text_Rate.setText(sdRate+""); //gives error

Copy file from source directory to binary directory using CMake

If you want to put the content of example into install folder after build:

code/
  src/
  example/
  CMakeLists.txt

try add the following to your CMakeLists.txt:

install(DIRECTORY example/ DESTINATION example)

error TS2339: Property 'x' does not exist on type 'Y'

If you want to be able to access images.main then you must define it explicitly:

interface Images {
    main: string;
    [key:string]: string;
}

function getMainImageUrl(images: Images): string {
    return images.main;
}

You can not access indexed properties using the dot notation because typescript has no way of knowing whether or not the object has that property.
However, when you specifically define a property then the compiler knows that it's there (or not), whether it's optional or not and what's the type.


Edit

You can have a helper class for map instances, something like:

class Map<T> {
    private items: { [key: string]: T };

    public constructor() {
        this.items = Object.create(null);
    }

    public set(key: string, value: T): void {
        this.items[key] = value;
    }

    public get(key: string): T {
        return this.items[key];
    }

    public remove(key: string): T {
        let value = this.get(key);
        delete this.items[key];
        return value;
    }
}

function getMainImageUrl(images: Map<string>): string {
    return images.get("main");
}

I have something like that implemented, and I find it very useful.

JS Client-Side Exif Orientation: Rotate and Mirror JPEG Images

For those who have a file from an input control, don't know what its orientation is, are a bit lazy and don't want to include a large library below is the code provided by @WunderBart melded with the answer he links to (https://stackoverflow.com/a/32490603) that finds the orientation.

function getDataUrl(file, callback2) {
        var callback = function (srcOrientation) {
            var reader2 = new FileReader();
            reader2.onload = function (e) {
                var srcBase64 = e.target.result;
                var img = new Image();

                img.onload = function () {
                    var width = img.width,
                        height = img.height,
                        canvas = document.createElement('canvas'),
                        ctx = canvas.getContext("2d");

                    // set proper canvas dimensions before transform & export
                    if (4 < srcOrientation && srcOrientation < 9) {
                        canvas.width = height;
                        canvas.height = width;
                    } else {
                        canvas.width = width;
                        canvas.height = height;
                    }

                    // transform context before drawing image
                    switch (srcOrientation) {
                        case 2: ctx.transform(-1, 0, 0, 1, width, 0); break;
                        case 3: ctx.transform(-1, 0, 0, -1, width, height); break;
                        case 4: ctx.transform(1, 0, 0, -1, 0, height); break;
                        case 5: ctx.transform(0, 1, 1, 0, 0, 0); break;
                        case 6: ctx.transform(0, 1, -1, 0, height, 0); break;
                        case 7: ctx.transform(0, -1, -1, 0, height, width); break;
                        case 8: ctx.transform(0, -1, 1, 0, 0, width); break;
                        default: break;
                    }

                    // draw image
                    ctx.drawImage(img, 0, 0);

                    // export base64
                    callback2(canvas.toDataURL());
                };

                img.src = srcBase64;
            }

            reader2.readAsDataURL(file);
        }

        var reader = new FileReader();
        reader.onload = function (e) {

            var view = new DataView(e.target.result);
            if (view.getUint16(0, false) != 0xFFD8) return callback(-2);
            var length = view.byteLength, offset = 2;
            while (offset < length) {
                var marker = view.getUint16(offset, false);
                offset += 2;
                if (marker == 0xFFE1) {
                    if (view.getUint32(offset += 2, false) != 0x45786966) return callback(-1);
                    var little = view.getUint16(offset += 6, false) == 0x4949;
                    offset += view.getUint32(offset + 4, little);
                    var tags = view.getUint16(offset, little);
                    offset += 2;
                    for (var i = 0; i < tags; i++)
                        if (view.getUint16(offset + (i * 12), little) == 0x0112)
                            return callback(view.getUint16(offset + (i * 12) + 8, little));
                }
                else if ((marker & 0xFF00) != 0xFF00) break;
                else offset += view.getUint16(offset, false);
            }
            return callback(-1);
        };
        reader.readAsArrayBuffer(file);
    }

which can easily be called like such

getDataUrl(input.files[0], function (imgBase64) {
      vm.user.BioPhoto = imgBase64;
});

Easiest way to rotate by 90 degrees an image using OpenCV?

Well I was looking for some details and didn't find any example. So I am posting a transposeImage function which, I hope, will help others who are looking for a direct way to rotate 90° without losing data:

IplImage* transposeImage(IplImage* image) {

    IplImage *rotated = cvCreateImage(cvSize(image->height,image->width),   
        IPL_DEPTH_8U,image->nChannels);
    CvPoint2D32f center;
    float center_val = (float)((image->width)-1) / 2;
    center.x = center_val;
    center.y = center_val;
    CvMat *mapMatrix = cvCreateMat( 2, 3, CV_32FC1 );        
    cv2DRotationMatrix(center, 90, 1.0, mapMatrix);
    cvWarpAffine(image, rotated, mapMatrix, 
        CV_INTER_LINEAR + CV_WARP_FILL_OUTLIERS, 
        cvScalarAll(0));      
    cvReleaseMat(&mapMatrix);

    return rotated;
}

Question : Why this?

float center_val = (float)((image->width)-1) / 2; 

Answer : Because it works :) The only center I found that doesn't translate image. Though if somebody has an explanation I would be interested.

Changing datagridview cell color dynamically

If you want every cell in the grid to have the same background color, you can just do this:

dataGridView1.DefaultCellStyle.BackColor = Color.Green;

How do SO_REUSEADDR and SO_REUSEPORT differ?

Mecki's answer is absolutly perfect, but it's worth adding that FreeBSD also supports SO_REUSEPORT_LB, which mimics Linux' SO_REUSEPORT behaviour - it balances the load; see setsockopt(2)

What techniques can be used to define a class in JavaScript, and what are their trade-offs?

The simple way is:

function Foo(a) {
  var that=this;

  function privateMethod() { .. }

  // public methods
  that.add = function(b) {
    return a + b;
  };
  that.avg = function(b) {
    return that.add(b) / 2; // calling another public method
  };
}

var x = new Foo(10);
alert(x.add(2)); // 12
alert(x.avg(20)); // 15

The reason for that is that this can be bound to something else if you give a method as an event handler, so you save the value during instantiation and use it later.

Edit: it's definitely not the best way, just a simple way. I'm waiting for good answers too!

No tests found with test runner 'JUnit 4'

You might be able to solve this simply by renaming your test class to have a name that ends with Test, e.g. ThisAndThatTest

Reading a plain text file in Java

This is basically the exact same as Jesus Ramos' answer, except with File instead of FileReader plus iteration to step through the contents of the file.

Scanner in = new Scanner(new File("filename.txt"));

while (in.hasNext()) { // Iterates each line in the file
    String line = in.nextLine();
    // Do something with line
}

in.close(); // Don't forget to close resource leaks

... throws FileNotFoundException

Getting the array length of a 2D array in Java

import java.util.Arrays;

public class Main {

    public static void main(String[] args) 
    {

        double[][] test = { {100}, {200}, {300}, {400}, {500}, {600}, {700}, {800}, {900}, {1000}};

        int [][] removeRow = { {0}, {1}, {3}, {4}, };

        double[][] newTest = new double[test.length - removeRow.length][test[0].length];

        for (int i = 0, j = 0, k = 0; i < test.length; i++) {
            if (j < removeRow.length) {
                if (i == removeRow[j][0]) {
                    j++;
                    continue;
                }
            }
            newTest[k][0] = test[i][0];
            k++;
        }

        System.out.println(Arrays.deepToString(newTest));   
    }
}

How to parse unix timestamp to time.Time

The time.Parse function does not do Unix timestamps. Instead you can use strconv.ParseInt to parse the string to int64 and create the timestamp with time.Unix:

package main

import (
    "fmt"
    "time"
    "strconv"
)

func main() {
    i, err := strconv.ParseInt("1405544146", 10, 64)
    if err != nil {
        panic(err)
    }
    tm := time.Unix(i, 0)
    fmt.Println(tm)
}

Output:

2014-07-16 20:55:46 +0000 UTC

Playground: http://play.golang.org/p/v_j6UIro7a

Edit:

Changed from strconv.Atoi to strconv.ParseInt to avoid int overflows on 32 bit systems.

How to clear the JTextField by clicking JButton

Looking for EventHandling, ActionListener?

or code?

JButton b = new JButton("Clear");
b.addActionListener(new ActionListener(){
    public void actionPerformed(ActionEvent e){
        textfield.setText("");
        //textfield.setText(null); //or use this
    }
});

Also See
How to Use Buttons

Export MySQL data to Excel in PHP

try this code

data.php

    <table border="1">
<tr>
    <th>NO.</th>
    <th>NAME</th>
    <th>Major</th>
</tr>
<?php
//connection to mysql
mysql_connect("localhost", "root", ""); //server , username , password
mysql_select_db("codelution");

//query get data
$sql = mysql_query("SELECT * FROM student ORDER BY id ASC");
$no = 1;
while($data = mysql_fetch_assoc($sql)){
    echo '
    <tr>
        <td>'.$no.'</td>
        <td>'.$data['name'].'</td>
        <td>'.$data['major'].'</td>
    </tr>
    ';
    $no++;
}
?>

code for excel file

export.php

<?php
// The function header by sending raw excel
header("Content-type: application/vnd-ms-excel");
// Defines the name of the export file "codelution-export.xls"
header("Content-Disposition: attachment; filename=codelution-export.xls");
// Add data table
include 'data.php';
?>

if mysqli version

$sql="SELECT * FROM user_details";
$result=mysqli_query($conn,$sql);
if(mysqli_num_rows($result) > 0)
{
    $no = 1;
            while($data = mysqli_fetch_assoc($result))
            {echo '
    <tr>
        <<td>'.$no.'</td>
        <td>'.$data['name'].'</td>
        <td>'.$data['major'].'</td>

    </tr>
    ';
    $no++;

http://codelution.com/development/web/easy-ways-to-export-data-from-mysql-to-excel-with-php/

When to use CouchDB over MongoDB and vice versa

Ask this questions yourself? And you will decide your DB selection.

  1. Do you need master-master? Then CouchDB. Mainly CouchDB supports master-master replication which anticipates nodes being disconnected for long periods of time. MongoDB would not do well in that environment.
  2. Do you need MAXIMUM R/W throughput? Then MongoDB
  3. Do you need ultimate single-server durability because you are only going to have a single DB server? Then CouchDB.
  4. Are you storing a MASSIVE data set that needs sharding while maintaining insane throughput? Then MongoDB.
  5. Do you need strong consistency of data? Then MongoDB.
  6. Do you need high availability of database? Then CouchDB.
  7. Are you hoping multi databases and multi tables/ collections? Then MongoDB
  8. You have a mobile app offline users and want to sync their activity data to a server? Then you need CouchDB.
  9. Do you need large variety of querying engine? Then MongoDB
  10. Do you need large community to be using DB? Then MongoDB

Learning to write a compiler

An easy way to create a compiler is to use bison and flex (or similar), build a tree (AST) and generate code in C. With generating C code being the most important step. By generating C code, your language will automatically work on all platforms that have a C compiler.

Generating C code is as easy as generating HTML (just use print, or equivalent), which in turn is much easier than writing a C parser or HTML parser.

What is the documents directory (NSDocumentDirectory)?

Like others mentioned, your app runs in a sandboxed environment and you can use the documents directory to store images or other assets your app may use, eg. downloading offline-d files as user prefers - File System Basics - Apple Documentation - Which directory to use, for storing application specific files

Updated to swift 5, you can use one of these functions, as per requirement -

func getDocumentsDirectory() -> URL {
    let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
    return paths[0]
}

func getCacheDirectory() -> URL {
        let paths = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask)
        return paths[0]
    }

func getApplicationSupportDirectory() -> URL {
        let paths = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask)
        return paths[0]
    }

Usage:

let urlPath = "https://jumpcloud.com/wp-content/uploads/2017/06/SSH-Keys.png" //Or string path to some URL of valid image, for eg.

if let url = URL(string: urlPath){
    let destination = getDocumentsDirectory().appendingPathComponent(url.lastPathComponent)
    do {
        let data = try Data(contentsOf: url) //Synchronous call, just as an example
        try data.write(to: destination)
    } catch _ {
        //Do something to handle the error
    }
}

How can I delete (not disable) ActiveX add-ons in Internet Explorer (7 and 8 Beta 2)?

You can go to IE Tools -> Internet options -> Advanced Tab. Under Advanced, check for security and put a check on the 1st 2 options which says,"Allow active content from CDs to run on My Computer* and Allow active content to run in files on My Computer*"

Restart your browser and the ActiveX scripts will not be shown.

bash: mkvirtualenv: command not found

Solved my issue in Ubuntu 14.04 OS with python 2.7.6, by adding below two lines into ~/.bash_profile (or ~/.bashrc in unix) files.

source "/usr/local/bin/virtualenvwrapper.sh"

export WORKON_HOME="/opt/virtual_env/"

And then executing both these lines onto the terminal.

ALTER COLUMN in sqlite

SQLite supports a limited subset of ALTER TABLE. The ALTER TABLE command in SQLite allows the user to rename a table or to add a new column to an existing table. It is not possible to rename a column, remove a column, or add or remove constraints from a table. But you can alter table column datatype or other property by the following steps.

  1. BEGIN TRANSACTION;
  2. CREATE TEMPORARY TABLE t1_backup(a,b);
  3. INSERT INTO t1_backup SELECT a,b FROM t1;
  4. DROP TABLE t1;
  5. CREATE TABLE t1(a,b);
  6. INSERT INTO t1 SELECT a,b FROM t1_backup;
  7. DROP TABLE t1_backup;
  8. COMMIT

For more detail you can refer the link.

How can I reference a commit in an issue comment on GitHub?

If you are trying to reference a commit in another repo than the issue is in, you can prefix the commit short hash with reponame@.

Suppose your commit is in the repo named dev, and the GitLab issue is in the repo named test. You can leave a comment on the issue and reference the commit by dev@e9c11f0a (where e9c11f0a is the first 8 letters of the sha hash of the commit you want to link to) if that makes sense.

Convert a JSON Object to Buffer and Buffer to JSON Object back

You need to stringify the json, not calling toString

var buf = Buffer.from(JSON.stringify(obj));

And for converting string to json obj :

var temp = JSON.parse(buf.toString());

How can I pass an Integer class correctly by reference?

There are 2 ways to pass by reference

  1. Use org.apache.commons.lang.mutable.MutableInt from Apache Commons library.
  2. Create custom class as shown below

Here's a sample code to do it:

public class Test {
    public static void main(String args[]) {
        Integer a = new Integer(1);
        Integer b = a;
        Test.modify(a);
        System.out.println(a);
        System.out.println(b);

        IntegerObj ao = new IntegerObj(1);
        IntegerObj bo = ao;
        Test.modify(ao);
        System.out.println(ao.value);
        System.out.println(bo.value);
    }


    static void modify(Integer x) {
        x=7;
    }
    static void modify(IntegerObj x) {
        x.value=7;
    }   
}

class IntegerObj {
    int value;
    IntegerObj(int val) {
        this.value = val;
    }
}

Output:

1
1
7
7

How to format DateTime in Flutter , How to get current time in flutter?

Here's my simple solution. That does not require any dependency.

However, the date will be in string format. If you want the time then change the substring values

print(new DateTime.now()
            .toString()
            .substring(0,10)
     );   // 2020-06-10

python setup.py uninstall

I think you can open the setup.py, locate the package name, and then ask pip to uninstall it.

Assuming the name is available in a 'METADATA' variable:

pip uninstall $(python -c "from setup import METADATA; print METADATA['name']")

Is there an exponent operator in C#?

The C# language doesn't have a power operator. However, the .NET Framework offers the Math.Pow method:

Returns a specified number raised to the specified power.

So your example would look like this:

float Result, Number1, Number2;

Number1 = 2;
Number2 = 2;

Result = Math.Pow(Number1, Number2);

How to make a div with no content have a width?

You add to this DIV's CSS position: relative, it will do all the work.

Best way to stress test a website

Try http://loadimpact.com the best I have found so far, but no alternative to it I can find.

How to convert const char* to char* in C?

To convert a const char* to char* you could create a function like this :

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

char* unconstchar(const char* s) {
    if(!s)
      return NULL;
    int i;
    char* res = NULL;
    res = (char*) malloc(strlen(s)+1);
    if(!res){
        fprintf(stderr, "Memory Allocation Failed! Exiting...\n");
        exit(EXIT_FAILURE);
    } else{
        for (i = 0; s[i] != '\0'; i++) {
            res[i] = s[i];
        }
        res[i] = '\0';
        return res;
    }
}

int main() {
    const char* s = "this is bikash";
    char* p = unconstchar(s);
    printf("%s",p);
    free(p);
}

How to use glyphicons in bootstrap 3.0

Download all files from bootstrap and then include this css

<style type="text/css">
        @font-face {
            font-family: 'Glyphicons Halflings';
            src: url('/fonts/glyphicons-halflings-regular.eot');
        }
 </style>

Mailto: Body formatting

From the first result on Google:

mailto:[email protected]_t?subject=Header&body=This%20is...%20the%20first%20line%0D%0AThis%20is%20the%20second

Online Internet Explorer Simulators

I just realized that there's yet another option. I've heard a lot of good things about this service: Litmus Alkaline.

"Alkaline tests your website designs across 17 different Windows browsers right from your Mac desktop in seconds. No need for virtual machines, Windows licenses, or any messing around with Windows Update."

Close a MessageBox after several seconds

I know this question is 8 year old, however there was and is a better solution for this purpose. It's always been there, and still is: User32.dll!MessageBoxTimeout.

This is an undocumented function used by Microsoft Windows, and it does exactly what you want and even more. It supports different languages as well.

C# Import:

[DllImport("user32.dll", SetLastError = true)]
public static extern int MessageBoxTimeout(IntPtr hWnd, String lpText, String lpCaption, uint uType, Int16 wLanguageId, Int32 dwMilliseconds);

[DllImport("user32.dll", SetLastError = true)]
public static extern IntPtr GetForegroundWindow();

How to use it in C#:

uint uiFlags = /*MB_OK*/ 0x00000000 | /*MB_SETFOREGROUND*/  0x00010000 | /*MB_SYSTEMMODAL*/ 0x00001000 | /*MB_ICONEXCLAMATION*/ 0x00000030;

NativeFunctions.MessageBoxTimeout(NativeFunctions.GetForegroundWindow(), $"Kitty", $"Hello", uiFlags, 0, 5000);

Work smarter, not harder.

Is there a pretty print for PHP?

For simplicity, print_r() and var_dump() can't be beat. If you want something a little fancier or are dealing with large lists and/or deeply nested data, Krumo will make your life much easier - it provides you with a nicely formatted collapsing/expanding display.

Insert Unicode character into JavaScript

The answer is correct, but you don't need to declare a variable. A string can contain your character:

"This string contains omega, that looks like this: \u03A9"

Unfortunately still those codes in ASCII are needed for displaying UTF-8, but I am still waiting (since too many years...) the day when UTF-8 will be same as ASCII was, and ASCII will be just a remembrance of the past.

Format / Suppress Scientific Notation from Python Pandas Aggregation Results

Setting a fixed number of decimal places globally is often a bad idea since it is unlikely that it will be an appropriate number of decimal places for all of your various data that you will display regardless of magnitude. Instead, try this which will give you scientific notation only for large and very small values (and adds a thousands separator unless you omit the ","):

pd.set_option('display.float_format', lambda x: '%,g' % x)

Or to almost completely suppress scientific notation without losing precision, try this:

pd.set_option('display.float_format', str)

create multiple tag docker image

Since 1.10 release, you can now add multiple tags at once on build:

docker build -t name1:tag1 -t name1:tag2 -t name2 .

Source: Add ability to add multiple tags with docker build

How to download the latest artifact from Artifactory repository?

In case you need to download an artifact in a Dockerfile, instead of using wget or curl or the likes you can simply use the 'ADD' directive:

ADD ${ARTIFACT_URL} /opt/app/app.jar

Of course, the tricky part is determining the ARTIFACT_URL, but there's enough about that in all the other answers.

However, Docker best practises strongly discourage using ADD for this purpose and recommend using wget or curl.

Error renaming a column in MySQL

FOR MYSQL:

ALTER TABLE `table_name` CHANGE `old_name` `new_name` VARCHAR(255) NOT NULL;

FOR ORACLE:

ALTER TABLE `table_name` RENAME COLUMN `old_name` TO `new_name`;

Frame Buster Buster ... buster code needed

You could improve the whole idea by using the postMessage() method to allow some domains to access and display your content while blocking all the others. First, the container-parent must introduce itself by posting a message to the contentWindow of the iframe that is trying to display your page. And your page must be ready to accept messages,

window.addEventListener("message", receiveMessage, false);

function receiveMessage(event) {
  // Use event.origin here like
  if(event.origin == "https://perhapsyoucantrustthisdomain.com"){
  // code here to block/unblock access ... a method like the one in user1646111's post can be good.
  }
  else{
  // code here to block/unblock access ... a method like the one in user1646111's post can be good.
  }
}

Finally don't forget to wrap things inside functions that will wait for load events.

Android overlay a view ontop of everything?

The best way is ViewOverlay , You can add any drawable as overlay to any view as its overlay since Android JellyBeanMR2(Api 18).

Add mMyDrawable to mMyView as its overlay:

mMyDrawable.setBounds(0, 0, mMyView.getMeasuredWidth(), mMyView.getMeasuredHeight())
mMyView.getOverlay().add(mMyDrawable)

getApplication() vs. getApplicationContext()

To answer the question, getApplication() returns an Application object and getApplicationContext() returns a Context object. Based on your own observations, I would assume that the Context of both are identical (i.e. behind the scenes the Application class calls the latter function to populate the Context portion of the base class or some equivalent action takes place). It shouldn't really matter which function you call if you just need a Context.

Is it possible to use vh minus pixels in a CSS calc()?

It does work indeed. Issue was with my less compiler. It was compiled in to:

.container {
  min-height: calc(-51vh);
}

Fixed with the following code in less file:

.container {
  min-height: calc(~"100vh - 150px");
}

Thanks to this link: Less Aggressive Compilation with CSS3 calc

HTML form with two submit buttons and two "target" attributes

In this example, taken from

http://www.webdeveloper.com/forum/showthread.php?t=75170

You can see the way to change the target on the button OnClick event.

function subm(f,newtarget)
{
document.myform.target = newtarget ;
f.submit();
}

<FORM name="myform" method="post" action="" target="" >

<INPUT type="button" name="Submit" value="Submit" onclick="subm(this.form,'_self');">
<INPUT type="button" name="Submit" value="Submit" onclick="subm(this.form,'_blank');">

Filter dataframe rows if value in column is in a set list of values

isin() is ideal if you have a list of exact matches, but if you have a list of partial matches or substrings to look for, you can filter using the str.contains method and regular expressions.

For example, if we want to return a DataFrame where all of the stock IDs which begin with '600' and then are followed by any three digits:

>>> rpt[rpt['STK_ID'].str.contains(r'^600[0-9]{3}$')] # ^ means start of string
...   STK_ID   ...                                    # [0-9]{3} means any three digits
...  '600809'  ...                                    # $ means end of string
...  '600141'  ...
...  '600329'  ...
...      ...   ...

Suppose now we have a list of strings which we want the values in 'STK_ID' to end with, e.g.

endstrings = ['01$', '02$', '05$']

We can join these strings with the regex 'or' character | and pass the string to str.contains to filter the DataFrame:

>>> rpt[rpt['STK_ID'].str.contains('|'.join(endstrings)]
...   STK_ID   ...
...  '155905'  ...
...  '633101'  ...
...  '210302'  ...
...      ...   ...

Finally, contains can ignore case (by setting case=False), allowing you to be more general when specifying the strings you want to match.

For example,

str.contains('pandas', case=False)

would match PANDAS, PanDAs, paNdAs123, and so on.

Detect Windows version in .net

This is a relatively old question but I've recently had to solve this problem and didn't see my solution posted anywhere.

The easiest (and simplest way in my opinion) is to just use a pinvoke call to RtlGetVersion

[DllImport("ntdll.dll", SetLastError = true)]
internal static extern uint RtlGetVersion(out Structures.OsVersionInfo versionInformation); // return type should be the NtStatus enum

[StructLayout(LayoutKind.Sequential)]
internal struct OsVersionInfo
{
    private readonly uint OsVersionInfoSize;

    internal readonly uint MajorVersion;
    internal readonly uint MinorVersion;

    private readonly uint BuildNumber;

    private readonly uint PlatformId;

    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)]
    private readonly string CSDVersion;
}

Where Major and Minor version numbers in this struct correspond to the values in the table of the accepted answer.

This returns the correct Windows version number unlike the deprecated GetVersion & GetVersionEx functions from kernel32

How do I measure execution time of a command on the Windows command line?

The following script uses only "cmd.exe" and outputs the number of milliseconds from the time a pipeline is created to the time that the process preceding the script exits. i.e., Type your command, and pipe the to the script. Example: "timeout 3 | runtime.cmd" should yield something like "2990." If you need both the runtime output and the stdin output, redirect stdin before the pipe - ex: "dir /s 1>temp.txt | runtime.cmd" would dump the output of the "dir" command to "temp.txt" and would print the runtime to the console.

:: --- runtime.cmd ----
@echo off
setlocal enabledelayedexpansion

:: find target for recursive calls
if not "%1"=="" (
    shift /1
    goto :%1
    exit /b
)

:: set pipeline initialization time
set t1=%time%

:: wait for stdin
more > nul

:: set time at which stdin was ready
set t2=!time!

::parse t1
set t1=!t1::= !
set t1=!t1:.= !
set t1=!t1: 0= !

:: parse t2
set t2=!t2::= !
set t2=!t2:.= !
set t2=!t2: 0= !

:: calc difference
pushd %~dp0
for /f %%i in ('%0 calc !t1!') do for /f %%j in ('%0 calc !t2!') do (
    set /a t=%%j-%%i
    echo !t!
)
popd
exit /b
goto :eof

:calc
set /a t=(%1*(3600*1000))+(%2*(60*1000))+(%3*1000)+(%4)
echo !t!
goto :eof

endlocal

OpenCV - Saving images to a particular folder of choice

You can use this simple code in loop by incrementing count

cv2.imwrite("C:\Sharat\Python\Images\frame%d.jpg" % count, image)

images will be saved in the folder by name line frame0.jpg, frame1.jpg frame2.jpg etc..

How does Trello access the user's clipboard?

Disclosure: I wrote the code that Trello uses; the code below is the actual source code Trello uses to accomplish the clipboard trick.


We don't actually "access the user's clipboard", instead we help the user out a bit by selecting something useful when they press Ctrl+C.

Sounds like you've figured it out; we take advantage of the fact that when you want to hit Ctrl+C, you have to hit the Ctrl key first. When the Ctrl key is pressed, we pop in a textarea that contains the text we want to end up on the clipboard, and select all the text in it, so the selection is all set when the C key is hit. (Then we hide the textarea when the Ctrl key comes up.)

Specifically, Trello does this:

TrelloClipboard = new class
  constructor: ->
    @value = ""

    $(document).keydown (e) =>
      # Only do this if there's something to be put on the clipboard, and it
      # looks like they're starting a copy shortcut
      if !@value || !(e.ctrlKey || e.metaKey)
        return

      if $(e.target).is("input:visible,textarea:visible")
        return

      # Abort if it looks like they've selected some text (maybe they're trying
      # to copy out a bit of the description or something)
      if window.getSelection?()?.toString()
        return

      if document.selection?.createRange().text
        return

      _.defer =>
        $clipboardContainer = $("#clipboard-container")
        $clipboardContainer.empty().show()
        $("<textarea id='clipboard'></textarea>")
        .val(@value)
        .appendTo($clipboardContainer)
        .focus()
        .select()

    $(document).keyup (e) ->
      if $(e.target).is("#clipboard")
        $("#clipboard-container").empty().hide()

  set: (@value) ->

In the DOM we've got:

<div id="clipboard-container"><textarea id="clipboard"></textarea></div>

CSS for the clipboard stuff:

#clipboard-container {
  position: fixed;
  left: 0px;
  top: 0px;
  width: 0px;
  height: 0px;
  z-index: 100;
  display: none;
  opacity: 0;
}
#clipboard {
  width: 1px;
  height: 1px;
  padding: 0px;
}

... and the CSS makes it so you can't actually see the textarea when it pops in ... but it's "visible" enough to copy from.

When you hover over a card, it calls

TrelloClipboard.set(cardUrl)

... so then the clipboard helper knows what to select when the Ctrl key is pressed.

How to set image name in Dockerfile?

Here is another version if you have to reference a specific docker file:

version: "3"
services:
  nginx:
    container_name: nginx
    build:
      context: ../..
      dockerfile: ./docker/nginx/Dockerfile
    image: my_nginx:latest

Then you just run

docker-compose build

Programmatically read from STDIN or input file in Perl

Do

$userinput =  <STDIN>; #read stdin and put it in $userinput
chomp ($userinput);    #cut the return / line feed character

if you want to read just one line

How do I align spans or divs horizontally?

You can use

.floatybox {
     display: inline-block;
     width: 123px;
}

If you only need to support browsers that have support for inline blocks. Inline blocks can have width, but are inline, like button elements.

Oh, and you might wnat to add vertical-align: top on the elements to make sure things line up

Java Look and Feel (L&F)

You can also use JTattoo (http://www.jtattoo.net/), it has a couple of cool themes that can be used.

Just download the jar and import it into your classpath, or add it as a maven dependency:

<dependency>
        <groupId>com.jtattoo</groupId>
        <artifactId>JTattoo</artifactId>
        <version>1.6.11</version>
</dependency>

Here is a list of some of the cool themes they have available:

  • com.jtattoo.plaf.acryl.AcrylLookAndFeel
  • com.jtattoo.plaf.aero.AeroLookAndFeel
  • com.jtattoo.plaf.aluminium.AluminiumLookAndFeel
  • com.jtattoo.plaf.bernstein.BernsteinLookAndFeel
  • com.jtattoo.plaf.fast.FastLookAndFeel
  • com.jtattoo.plaf.graphite.GraphiteLookAndFeel
  • com.jtattoo.plaf.hifi.HiFiLookAndFeel
  • com.jtattoo.plaf.luna.LunaLookAndFeel
  • com.jtattoo.plaf.mcwin.McWinLookAndFeel
  • com.jtattoo.plaf.mint.MintLookAndFeel
  • com.jtattoo.plaf.noire.NoireLookAndFeel
  • com.jtattoo.plaf.smart.SmartLookAndFeel
  • com.jtattoo.plaf.texture.TextureLookAndFeel
  • com.jtattoo.plaf.custom.flx.FLXLookAndFeel

Regards

Python 3 string.join() equivalent?

'.'.join() or ".".join().. So any string instance has the method join()

Count work days between two dates

For difference between dates including holidays I went this way:

1) Table with Holidays:

    CREATE TABLE [dbo].[Holiday](
[Id] [int] IDENTITY(1,1) NOT NULL,
[Name] [nvarchar](50) NULL,
[Date] [datetime] NOT NULL)

2) I had my plannings Table like this and wanted to fill column Work_Days which was empty:

    CREATE TABLE [dbo].[Plan_Phase](
[Id] [int] IDENTITY(1,1) NOT NULL,
[Id_Plan] [int] NOT NULL,
[Id_Phase] [int] NOT NULL,
[Start_Date] [datetime] NULL,
[End_Date] [datetime] NULL,
[Work_Days] [int] NULL)

3) So in order to get "Work_Days" to later fill in my column just had to:

SELECT Start_Date, End_Date,
 (DATEDIFF(dd, Start_Date, End_Date) + 1)
-(DATEDIFF(wk, Start_Date, End_Date) * 2)
-(SELECT COUNT(*) From Holiday Where Date  >= Start_Date AND Date <= End_Date)
-(CASE WHEN DATENAME(dw, Start_Date) = 'Sunday' THEN 1 ELSE 0 END)
-(CASE WHEN DATENAME(dw, End_Date) = 'Saturday' THEN 1 ELSE 0 END)
-(CASE WHEN (SELECT COUNT(*) From Holiday Where Start_Date  = Date) > 0 THEN 1 ELSE 0 END)
-(CASE WHEN (SELECT COUNT(*) From Holiday Where End_Date  = Date) > 0 THEN 1 ELSE 0 END) AS Work_Days
from Plan_Phase

Hope that I could help.

Cheers

Set initial focus in an Android application

I just add this line of code into onCreate():

this.getWindow().setSoftInputMode(
    WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);

Problem solved.

Table cell widths - fixing width, wrapping/truncating long words

<style type="text/css">
td { word-wrap: break-word;max-width:50px; }            
</style>

Cannot connect to local SQL Server with Management Studio

Check the sql log in the LOG directory of your instance - see if anything is going on there. You'll need to stop the service to open the log - or restart and you can read the old one - named with .1 on the end.

With the error you're getting, you need to enable TCP/IP or Named pipes for named connections. Shared memory connection should work, but you seem to not be using that. Are you trying to connect through SSMS?

In my log I see entries like this...

Server local connection provider is ready to accept connection on [\\.\pipe\mssql$sqlexpress\sql\query ]

As the comments said, .\SQLEXPRESS should work. Also worstationName\SQLEXPRESS will work.

Oracle SQL Developer spool output?

For Spooling in Oracle SQL Developer, here is the solution.

set heading on

set linesize 1500

set colsep '|'

set numformat 99999999999999999999

set pagesize 25000

spool E:\abc.txt

@E:\abc.sql;

spool off

The hint is :

  1. when we spool from sql plus , then the whole query is required.

  2. when we spool from Oracle Sql Developer , then the reference path of the query required as given in the specified example.

DB2 Date format

This isn't straightforward, but

SELECT CHAR(CURRENT DATE, ISO) FROM SYSIBM.SYSDUMMY1

returns the current date in yyyy-mm-dd format. You would have to substring and concatenate the result to get yyyymmdd.

SELECT SUBSTR(CHAR(CURRENT DATE, ISO), 1, 4) ||
    SUBSTR(CHAR(CURRENT DATE, ISO), 6, 2) ||
    SUBSTR(CHAR(CURRENT DATE, ISO), 9, 2)
FROM SYSIBM.SYSDUMMY1

Convert output of MySQL query to utf8

You can use CAST and CONVERT to switch between different types of encodings. See: http://dev.mysql.com/doc/refman/5.0/en/charset-convert.html

SELECT column1, CONVERT(column2 USING utf8)
FROM my_table 
WHERE my_condition;

How do I return multiple values from a function?

A lot of the answers suggest you need to return a collection of some sort, like a dictionary or a list. You could leave off the extra syntax and just write out the return values, comma-separated. Note: this technically returns a tuple.

def f():
    return True, False
x, y = f()
print(x)
print(y)

gives:

True
False

What are forward declarations in C++?

The term "forward declaration" in C++ is mostly only used for class declarations. See (the end of) this answer for why a "forward declaration" of a class really is just a simple class declaration with a fancy name.

In other words, the "forward" just adds ballast to the term, as any declaration can be seen as being forward in so far as it declares some identifier before it is used.

(As to what is a declaration as opposed to a definition, again see What is the difference between a definition and a declaration?)

Setting the User-Agent header for a WebClient request

I found that the WebClient kept removing my User-Agent header after one request and I was tired of setting it each time. I used a hack to set the User-Agent permanently by making my own custom WebClient and overriding the GetWebRequest method. Hope this helps.

public class CustomWebClient : WebClient
{
    public CustomWebClient(){}

    protected override WebRequest GetWebRequest(Uri address)
    {
        var request = base.GetWebRequest(address) as HttpWebRequest;
        request.UserAgent="Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/6.0;)";

        //... your other custom code...

        return request;
    }
}

Access maven properties defined in the pom

This can be done with standard java properties in combination with the maven-resource-plugin with enabled filtering on properties.

For more info see http://maven.apache.org/plugins/maven-resources-plugin/examples/filter.html

This will work for standard maven project as for plugin projects

Add (insert) a column between two columns in a data.frame

`

data1 <- data.frame(col1=1:4, col2=5:8, col3=9:12)
row.names(data1) <- c("row1","row2","row3","row4")
data1
data2 <- data.frame(col1=21:24, col2=25:28, col3=29:32)
row.names(data2) <- c("row1","row2","row3","row4")
data2
insertPosition = 2
leftBlock <- unlist(data1[,1:(insertPosition-1)])
insertBlock <- unlist(data2[,1:length(data2[1,])])
rightBlock <- unlist(data1[,insertPosition:length(data1[1,])])
newData <- matrix(c(leftBlock, insertBlock, rightBlock), nrow=length(data1[,1]), byrow=FALSE)
newData

`

Setting an image button in CSS - image:active

Check this link . You were missing . before myButton. It was a small error. :)

.myButton{
    background:url(./images/but.png) no-repeat;
    cursor:pointer;
    border:none;
    width:100px;
    height:100px;
}

.myButton:active  /* use Dot here */
{   
    background:url(./images/but2.png) no-repeat;
}

Fatal error: Call to undefined function socket_create()

I got this error when my .env file was not set up properly. Make sure you have a .env file with valid database login credentials.

How to remove item from array by value?

ES6 way.

const commentsWithoutDeletedArray = commentsArray.filter(comment => comment.Id !== commentId);

"Unknown class <MyClass> in Interface Builder file" error at runtime

I had "Unknown class RateView in Interface Builder" where RateView was a subclass of UIView. I had dropped a UIView onto my Storyboard scene and changed the Custom class field to RateView. Still, this error appeared.

To debug, I changed the name of my class to RateView2 and changed all references to match except the Custom class field of the UIView. The error message still appeared as before with RateView as the missing class. This confirmed that the error message was related to the value of the Custom class field. I changed this value to RateView2 and the error message changed to "Unknown class RateView2 in Interface Builder". Progress of sorts.

Finally, I inspected the source code files themselves in the File Inspector. There I discovered that the source code file (which I had copied from a tutorial) was not associated with my Target. In other words, it had no Target Membership. I checked the box that made the class's source code file a member of the target app and the error message went away.

How do I use boolean variables in Perl?

Perl doesn't have a native boolean type, but you can use comparison of integers or strings in order to get the same behavior. Alan's example is a nice way of doing that using comparison of integers. Here's an example

my $boolean = 0;
if ( $boolean ) {
    print "$boolean evaluates to true\n";
} else {
    print "$boolean evaluates to false\n";
}

One thing that I've done in some of my programs is added the same behavior using a constant:

#!/usr/bin/perl

use strict;
use warnings;

use constant false => 0;
use constant true  => 1;

my $val1 = true;
my $val2 = false;

print $val1, " && ", $val2;
if ( $val1 && $val2 ) {
    print " evaluates to true.\n";
} else {
    print " evaluates to false.\n";
}

print $val1, " || ", $val2;
if ( $val1 || $val2 ) {
    print " evaluates to true.\n";
} else {
    print " evaluates to false.\n";
}

The lines marked in "use constant" define a constant named true that always evaluates to 1, and a constant named false that always evaluates by 0. Because of the way that constants are defined in Perl, the following lines of code fails as well:

true = 0;
true = false;

The error message should say something like "Can't modify constant in scalar assignment."

I saw that in one of the comments you asked about comparing strings. You should know that because Perl combines strings and numeric types in scalar variables, you have different syntax for comparing strings and numbers:

my $var1 = "5.0";
my $var2 = "5";

print "using operator eq\n";
if ( $var1 eq $var2 ) {
    print "$var1 and $var2 are equal!\n";
} else {
    print "$var1 and $var2 are not equal!\n";
}

print "using operator ==\n";
if ( $var1 == $var2 ) {
    print "$var1 and $var2 are equal!\n";
} else {
    print "$var1 and $var2 are not equal!\n";
}

The difference between these operators is a very common source of confusion in Perl.

Build error: "The process cannot access the file because it is being used by another process"

I had the same issue and could not rectify by using any of the methods mentioned in previous answers. I resolved the issue by killing all instances of "SSIS Debug Hist (32 bit)" in task manager and now working as normal.

How do I replicate a \t tab space in HTML?

&nbsp;&nbsp;&nbsp;&nbsp; would be a work around if you're only after the spacing.

How can I use modulo operator (%) in JavaScript?

That would be the modulo operator, which produces the remainder of the division of two numbers.

Full width image with fixed height

This can done several ways. I usually do it from my class.

From class

.image
{
    width:100%;


}

and for this your html would be:

<img class="image" src="images/image_name">

or if you want to style it using inline styling then you would just have:

<img style="width:100%; height:60px" id="image" src="images/image_name">

I however recommend doing it from your external style-sheet because as your project grows you will realize that the entire thing is easier managed with separate files for your html and your css.

Laravel - Model Class not found

I was having the same "Class [class name] not found" error message, but it wasn't a namespace issue. All my namespaces were set up correctly. I even tried composer dump-autoload and it didn't help me.

Surprisingly (to me) I then did composer dump-autoload -o which according to Composer's help, "optimizes PSR0 and PSR4 packages to be loaded with classmaps too, good for production." Somehow doing it that way got composer to behave and include the class correctly in the autoload_classmap.php file.

html div onclick event

Try following :

$('.expandable-panel-heading').click(function (e) {
        if(e.target.nodeName == 'A'){
            markActiveLink(e.target)
            return; 
        }else{
            alert('123');
        }
 });

function markActiveLink(el) {   
    alert($(el).attr("id"));
} 

Here is the working demo : http://jsfiddle.net/JVrNc/4/

GoogleMaps API KEY for testing

Updated Answer

As of June11, 2018 it is now mandatory to have a billing account to get API key. You can still make keyless calls to the Maps JavaScript API and Street View Static API which will return low-resolution maps that can be used for development. Enabling billing still gives you $200 free credit monthly for your projects.

This answer is no longer valid

As long as you're using a testing API key it is free to register and use. But when you move your app to commercial level you have to pay for it. When you enable billing, google gives you $200 credit free each month that means if your app's map usage is low you can still use it for free even after the billing enabled, if it exceeds the credit limit now you have to pay for it.

Invoke native date picker from web-app on iOS/Android

On your form elements use input type="time". It will save you all the hassle of trying to use a data picker library.

How to append something to an array?

We don't have append function for Array in javascript, but we have push and unshift, imagine you have the array below:

var arr = [1, 2, 3, 4, 5];

and we like append a value to this array, we can do, arr.push(6) and it will add 6 to the end of the array:

arr.push(6); // return [1, 2, 3, 4, 5, 6];

also we can use unshift, look at how we can apply this:

arr.unshift(0); //return [0, 1, 2, 3, 4, 5];

They are main functions to add or append new values to the arrays.

Is the 'as' keyword required in Oracle to define an alias?

<kdb></kdb> is required when we have a space in Alias Name like

SELECT employee_id,department_id AS "Department ID"
FROM employees
order by department

What is difference between INNER join and OUTER join

INNER JOIN: Returns all rows when there is at least one match in BOTH tables

LEFT JOIN: Return all rows from the left table, and the matched rows from the right table

RIGHT JOIN: Return all rows from the right table, and the matched rows from the left table

FULL JOIN: Return all rows when there is a match in ONE of the tables

Select query to remove non-numeric characters

To add on to Ken's answer, this handles commas and spaces and parentheses

--Handles parentheses, commas, spaces, hyphens..
declare @table table (c varchar(256))
insert into @table
values
('This is a test 111-222-3344'),
('Some Sample Text (111)-222-3344'),
('Hello there 111222 3344 / How are you?'),
('Hello there 111 222 3344 ? How are you?'),
('Hello there 111 222 3344. How are you?')

select
replace(LEFT(SUBSTRING(replace(replace(replace(replace(replace(c,'(',''),')',''),'-',''),' ',''),',',''), PATINDEX('%[0-9.-]%', replace(replace(replace(replace(replace(c,'(',''),')',''),'-',''),' ',''),',','')), 8000),
           PATINDEX('%[^0-9.-]%', SUBSTRING(replace(replace(replace(replace(replace(c,'(',''),')',''),'-',''),' ',''),',',''), PATINDEX('%[0-9.-]%', replace(replace(replace(replace(replace(c,'(',''),')',''),'-',''),' ',''),',','')), 8000) + 'X') -1),'.','')
from @table

ggplot2 legend to bottom and horizontal

If you want to move the position of the legend please use the following code:

library(reshape2) # for melt
df <- melt(outer(1:4, 1:4), varnames = c("X1", "X2"))
p1 <- ggplot(df, aes(X1, X2)) + geom_tile(aes(fill = value))
p1 + scale_fill_continuous(guide = guide_legend()) +
    theme(legend.position="bottom")

This should give you the desired result. Legend at bottom

Phonegap Cordova installation Windows

After hours of frustration... here's what i discovered.

  1. Ignore the installation documentation and all the command line, node.js stuff (seriously you will waste hours on this.
  2. Go to github and simply download the PhoneGap master .zip
  3. In that zip are project files for window phone, etc platform... just use those templates.

I don't know how such an easy process could have worse documentation. It as if it was written by lawyers.

Using async/await with a forEach loop

Similar to Antonio Val's p-iteration, an alternative npm module is async-af:

const AsyncAF = require('async-af');
const fs = require('fs-promise');

function printFiles() {
  // since AsyncAF accepts promises or non-promises, there's no need to await here
  const files = getFilePaths();

  AsyncAF(files).forEach(async file => {
    const contents = await fs.readFile(file, 'utf8');
    console.log(contents);
  });
}

printFiles();

Alternatively, async-af has a static method (log/logAF) that logs the results of promises:

const AsyncAF = require('async-af');
const fs = require('fs-promise');

function printFiles() {
  const files = getFilePaths();

  AsyncAF(files).forEach(file => {
    AsyncAF.log(fs.readFile(file, 'utf8'));
  });
}

printFiles();

However, the main advantage of the library is that you can chain asynchronous methods to do something like:

const aaf = require('async-af');
const fs = require('fs-promise');

const printFiles = () => aaf(getFilePaths())
  .map(file => fs.readFile(file, 'utf8'))
  .forEach(file => aaf.log(file));

printFiles();

async-af

Angular JS POST request not sending JSON data

I have tried your example and it works just fine:

var app = 'AirFare';
var d1 = new Date();
var d2 = new Date();

$http({
    url: '/api/test',
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    data: {application: app, from: d1, to: d2}
});

Output:

Content-Length:91
Content-Type:application/json
Host:localhost:1234
Origin:http://localhost:1234
Referer:http://localhost:1234/index.html
User-Agent:Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.66 Safari/537.36
X-Requested-With:XMLHttpRequest
Request Payload
{"application":"AirFare","from":"2013-10-10T11:47:50.681Z","to":"2013-10-10T11:47:50.681Z"}

Are you using the latest version of AngularJS?

possibly undefined macro: AC_MSG_ERROR

i also had similar problem.. my solution is to

apt-get install libcurl4-openssl-dev

(i had libcurl allready installed ) worked for me at least..

Animate text change in UILabel

Swift 2.0:

UIView.transitionWithView(self.view, duration: 1.0, options: UIViewAnimationOptions.TransitionCrossDissolve, animations: {
    self.sampleLabel.text = "Animation Fade1"
    }, completion: { (finished: Bool) -> () in
        self.sampleLabel.text = "Animation Fade - 34"
})

OR

UIView.animateWithDuration(0.2, animations: {
    self.sampleLabel.alpha = 1
}, completion: {
    (value: Bool) in
    self.sampleLabel.alpha = 0.2
})

How to create a custom attribute in C#

While the code to create a custom Attribute is fairly simple, it's very important that you understand what attributes are:

Attributes are metadata compiled into your program. Attributes themselves do not add any functionality to a class, property or module - just data. However, using reflection, one can leverage those attributes in order to create functionality.

So, for instance, let's look at the Validation Application Block, from Microsoft's Enterprise Library. If you look at a code example, you'll see:

    /// <summary>
    /// blah blah code.
    /// </summary>
    [DataMember]
    [StringLengthValidator(8, RangeBoundaryType.Inclusive, 8, RangeBoundaryType.Inclusive, MessageTemplate = "\"{1}\" must always have \"{4}\" characters.")]
    public string Code { get; set; }

From the snippet above, one might guess that the code will always be validated, whenever changed, accordingly to the rules of the Validator (in the example, have at least 8 characters and at most 8 characters). But the truth is that the Attribute does nothing; as mentioned previously, it only adds metadata to the property.

However, the Enterprise Library has a Validation.Validate method that will look into your object, and for each property, it'll check if the contents violate the rule informed by the attribute.

So, that's how you should think about attributes -- a way to add data to your code that might be later used by other methods/classes/etc.

INSTALL_FAILED_MISSING_SHARED_LIBRARY error in Android

In my case, it was that the app had defaulted to a Wearable target device.

I removed the reference to Wearable in my Manifest, and the problem was solved.

<uses-library android:name="com.google.android.wearable" android:required="true" />

How to inject JPA EntityManager using spring

Yes, although it's full of gotchas, since JPA is a bit peculiar. It's very much worth reading the documentation on injecting JPA EntityManager and EntityManagerFactory, without explicit Spring dependencies in your code:

http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/orm.html#orm-jpa

This allows you to either inject the EntityManagerFactory, or else inject a thread-safe, transactional proxy of an EntityManager directly. The latter makes for simpler code, but means more Spring plumbing is required.

Escape quotes in JavaScript

Escape whitespace as well. It sounds to me like Firefox is assuming three arguments instead of one. &nbsp; is the non-breaking space character. Even if it's not the whole problem, it may still be a good idea.

How to keep keys/values in same order as declared?

Rather than explaining the theoretical part, I'll give a simple example.

>>> from collections import OrderedDict
>>> my_dictionary=OrderedDict()
>>> my_dictionary['foo']=3
>>> my_dictionary['aol']=1
>>> my_dictionary
OrderedDict([('foo', 3), ('aol', 1)])
>>> dict(my_dictionary)
{'foo': 3, 'aol': 1}

Convert PDF to clean SVG?

Here is the NodeJS REST api for two PDF render scripts. https://github.com/pumppi/pdf2images

Scripts are: pdf2svg and Imagemagicks convert

Portable way to get file size (in bytes) in shell?

Finally I decided to use ls, and bash array expansion:

TEMP=( $( ls -ln FILE ) )
SIZE=${TEMP[4]}

it's not really nice, but at least it does only 1 fork+execve, and it doesn't rely on secondary programming language (perl/ruby/python/whatever)

back button callback in navigationController in iOS

Here's another way I implemented (didn't test it with an unwind segue but it probably wouldn't differentiate, as others have stated in regards to other solutions on this page) to have the parent view controller perform actions before the child VC it pushed gets popped off the view stack (I used this a couple levels down from the original UINavigationController). This could also be used to perform actions before the childVC gets pushed, too. This has the added advantage of working with the iOS system back button, instead of having to create a custom UIBarButtonItem or UIButton.

  1. Have your parent VC adopt the UINavigationControllerDelegate protocol and register for delegate messages:

    MyParentViewController : UIViewController <UINavigationControllerDelegate>
    
    -(void)viewDidLoad {
        self.navigationcontroller.delegate = self;
    }
    
  2. Implement this UINavigationControllerDelegate instance method in MyParentViewController:

    - (id<UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController animationControllerForOperation:(UINavigationControllerOperation)operation fromViewController:(UIViewController *)fromVC toViewController:(UIViewController *)toVC {
        // Test if operation is a pop; can also test for a push (i.e., do something before the ChildVC is pushed
        if (operation == UINavigationControllerOperationPop) {
            // Make sure it's the child class you're looking for
            if ([fromVC isKindOfClass:[ChildViewController class]]) {
                // Can handle logic here or send to another method; can also access all properties of child VC at this time
                return [self didPressBackButtonOnChildViewControllerVC:fromVC];
            }
        }
        // If you don't want to specify a nav controller transition
        return nil;
    }
    
  3. If you specify a specific callback function in the above UINavigationControllerDelegate instance method

    -(id <UIViewControllerAnimatedTransitioning>)didPressBackButtonOnAddSearchRegionsVC:(UIViewController *)fromVC {
        ChildViewController *childVC = ChildViewController.new;
        childVC = (ChildViewController *)fromVC;
    
        // childVC.propertiesIWantToAccess go here
    
        // If you don't want to specify a nav controller transition
        return nil;
    

    }

How to get height of entire document with JavaScript?

This cross browser code below evaluates all possible heights of the body and html elements and returns the max found:

            var body = document.body;
            var html = document.documentElement;
            var bodyH = Math.max(body.scrollHeight, body.offsetHeight, body.getBoundingClientRect().height, html.clientHeight, html.scrollHeight, html.offsetHeight); // The max height of the body

A working example:

_x000D_
_x000D_
function getHeight()_x000D_
{_x000D_
  var body = document.body;_x000D_
  var html = document.documentElement; _x000D_
  var bodyH = Math.max(body.scrollHeight, body.offsetHeight, body.getBoundingClientRect().height, html.clientHeight, html.scrollHeight, html.offsetHeight);_x000D_
  return bodyH;_x000D_
}_x000D_
_x000D_
document.getElementById('height').innerText = getHeight();
_x000D_
body,html_x000D_
{_x000D_
  height: 3000px;_x000D_
}_x000D_
_x000D_
#posbtm_x000D_
{_x000D_
  bottom: 0;_x000D_
  position: fixed;_x000D_
  background-color: Yellow;_x000D_
}
_x000D_
<div id="posbtm">The max Height of this document is: <span id="height"></span> px</div>_x000D_
_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />_x000D_
example document body content example document body content example document body content example document body content <br />
_x000D_
_x000D_
_x000D_

How to initailize byte array of 100 bytes in java with all 0's

byte[] bytes = new byte[100];

Initializes all byte elements with default values, which for byte is 0. In fact, all elements of an array when constructed, are initialized with default values for the array element's type.

How to switch text case in visual studio code

Now an uppercase and lowercase switch can be done simultaneously in the selected strings via a regular expression replacement (regex, CtrlH + AltR), according to v1.47.3 June 2020 release:

Replacing different text cases in one selection

This is done through 4 "Single character" character classes (Perl documentation), namely, for the matched group following it:

  • \l <=> [[:lower:]]: first character becomes lowercase
  • \u <=> [[:upper:]]: first character becomes uppercase
  • \L <=> [^[:lower:]]: all characters become lowercase
  • \U <=> [^[:upper:]]: all characters become uppercase

$0 matches all selected groups, while $1 matches the 1st group, $2 the 2nd one, etc.

Hit the Match Case button at the left of the search bar (or AltC) and, borrowing some examples from an old Sublime Text answer, now this is possible:

  1. Capitalize words
  • Find: (\s)([a-z]) (\s matches spaces and new lines, i.e. " venuS" => " VenuS")
  • Replace: $1\u$2
  1. Uncapitalize words
  • Find: (\s)([A-Z])
  • Replace: $1\l$2
  1. Remove a single camel case (e.g. cAmelCAse => camelcAse => camelcase)
  • Find: ([a-z])([A-Z])
  • Replace: $1\l$2
  1. Lowercase all from an uppercase letter within words (e.g. LowerCASe => Lowercase)
  • Find: (\w)([A-Z]+)
  • Replace: $1\L$2
  • Alternate Replace: \L$0
  1. Uppercase all from a lowercase letter within words (e.g. upperCASe => uPPERCASE)
  • Find: (\w)([A-Z]+)
  • Replace: $1\U$2
  1. Uppercase previous (e.g. upperCase => UPPERCase)
  • Find: (\w+)([A-Z])
  • Replace: \U$1$2
  1. Lowercase previous (e.g. LOWERCase => lowerCase)
  • Find: (\w+)([A-Z])
  • Replace: \L$1$2
  1. Uppercase the rest (e.g. upperCase => upperCASE)
  • Find: ([A-Z])(\w+)
  • Replace: $1\U$2
  1. Lowercase the rest (e.g. lOWERCASE => lOwercase)
  • Find: ([A-Z])(\w+)
  • Replace: $1\L$2
  1. Shift-right-uppercase (e.g. Case => cAse => caSe => casE)
  • Find: ([a-z\s])([A-Z])(\w)
  • Replace: $1\l$2\u$3
  1. Shift-left-uppercase (e.g. CasE => CaSe => CAse => Case)
  • Find: (\w)([A-Z])([a-z\s])
  • Replace: \u$1\l$2$3

file_get_contents() Breaks Up UTF-8 Characters

I had a similar problem, what solved it was html_entity_decode.

My code is:

$content = file_get_contents("http://example.com/fr");
$x = new SimpleXMLElement($content);
foreach($x->channel->item as $entry) {
    $subEntry = html_entity_decode($entry->description);
}

In here I am retrieving an xml file (in French), that's why I'm using this $x object variable. And only then I decode it into this variable $subEntry.

I tried mb_convert_encoding but this didn't work for me.

How to add a default include path for GCC in Linux?

Create an alias for gcc with your favorite includes.

alias mygcc='gcc -I /whatever/'

Get name of currently executing test in JUnit 4

JUnit 4 does not have any out-of-the-box mechanism for a test case to get it’s own name (including during setup and teardown).

How to pass event as argument to an inline event handler in JavaScript?

to pass the event object:

<p id="p" onclick="doSomething(event)">

to get the clicked child element (should be used with event parameter:

function doSomething(e) {
    e = e || window.event;
    var target = e.target || e.srcElement;
    console.log(target);
}

to pass the element itself (DOMElement):

<p id="p" onclick="doThing(this)">

see live example on jsFiddle.

You can specify the name of the event as above, but alternatively your handler can access the event parameter as described here: "When the event handler is specified as an HTML attribute, the specified code is wrapped into a function with the following parameters". There's much more additional documentation at the link.

What is the standard exception to throw in Java for not supported/implemented operations?

If you want more granularity and better decription, you could use NotImplementedException from commons-lang

Warning: Available before versions 2.6 and after versions 3.2, only.

Contain form within a bootstrap popover?

<a data-title="A Title" data-placement="top" data-html="true" data-content="<form><input type='text'/></form>" data-trigger="hover" rel="popover" class="btn btn-primary" id="test">Top popover</a>

just state data-html="true"

correct PHP headers for pdf file download

I had the same problem recently and this helped me:

    header('Content-Description: File Transfer'); 
    header('Content-Type: application/octet-stream'); 
    header('Content-Disposition: attachment; filename="FILENAME"'); 
    header('Content-Transfer-Encoding: binary'); 
    header('Expires: 0'); 
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0'); 
    header('Pragma: public'); 
    header('Content-Length: ' . filesize("PATH/TO/FILE")); 
    ob_clean(); 
    flush(); 
    readfile(PATH/TO/FILE);      
    exit();

I found this answer here

Table and Index size in SQL Server

EXEC sp_MSforeachtable @command1="EXEC sp_spaceused '?'"

Syntax error: Illegal return statement in JavaScript

This can happen in ES6 if you use the incorrect (older) syntax for static methods:

export default class MyClass
{
    constructor()
    {
       ...
    }

    myMethod()
    {
       ...
    }
}

MyClass.someEnum = {Red: 0, Green: 1, Blue: 2}; //works

MyClass.anotherMethod() //or
MyClass.anotherMethod = function()
{
   return something; //doesn't work
}

Whereas the correct syntax is:

export default class MyClass
{
    constructor()
    {
       ...
    }

    myMethod()
    {
       ...
    }

    static anotherMethod()
    {
       return something; //works
    }
}

MyClass.someEnum = {Red: 0, Green: 1, Blue: 2}; //works

Where is android studio building my .apk file?

I was having the issue finding my debug apk. Android Studio 0.8.6 did not show the apk or even the output folder at project/project/build/. When I checked the same path project/project/build/ from windows folder explorer, I found the "output" folder there and the debug apk inside it.

How to create cron job using PHP?

function _cron_exe($schedules) {
        if ($obj->get_option('cronenabledisable') == "yes") {
            // $interval = 1*20;
            $interval = $obj->get_option('cronhowtime');
            if ($obj->get_option('crontiming') == 'minutes') {
                $interval = $interval * 60;
            } else if ($obj->get_option('crontiming') == 'hours') {
                $interval = $interval * 3600;
            } else if ($obj->get_option('crontiming') == 'days') {
                $interval = $interval * 86400;
            }
            $schedules['hourlys'] = array(
                'interval' => $interval,
                'display' => 'cronjob'
            );
            return $schedules;
        }

}

Regex empty string or email

matching empty string or email

(^$|^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.(?:[a-zA-Z]{2}|com|org|net|edu|gov|mil|biz|info|mobi|name|aero|asia|jobs|museum)$)

matching empty string or email but also matching any amount of whitespace

(^\s*$|^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.(?:[a-zA-Z]{2}|com|org|net|edu|gov|mil|biz|info|mobi|name|aero|asia|jobs|museum)$)

see more about the email matching regex itself:

http://www.regular-expressions.info/email.html

How to loop and render elements in React-native?

You would usually use map for that kind of thing.

buttonsListArr = initialArr.map(buttonInfo => (
  <Button ... key={buttonInfo[0]}>{buttonInfo[1]}</Button>
);

(key is a necessary prop whenever you do mapping in React. The key needs to be a unique identifier for the generated component)

As a side, I would use an object instead of an array. I find it looks nicer:

initialArr = [
  {
    id: 1,
    color: "blue",
    text: "text1"
  },
  {
    id: 2,
    color: "red",
    text: "text2"
  },
];

buttonsListArr = initialArr.map(buttonInfo => (
  <Button ... key={buttonInfo.id}>{buttonInfo.text}</Button>
);