Programs & Examples On #Session per request

'node' is not recognized as an internal or an external command, operable program or batch file while using phonegap/cordova

Add a system variable named "node", with value of your node path. It solves my problem, hope it helps.

How to save an image to localStorage and display it on the next page?

If your images keep getting cropped, here's some code to get the dimensions of the image file before saving to localstorage.

First, I would create some hidden input boxes to hold the width and height values

<input id="file-h" hidden type="text"/>
<input id="file-w" hidden type="text"/>

Then get the dimensions of your file into the input boxes

var _URL = window.URL || window.webkitURL;
$("#file-input").change(function(e) {
    var file, img;
    if ((file = this.files[0])) {
        img = new Image();
        img.onload = function() {
            $("#file-h").val(this.height);
            $("#file-w").val(this.width);
        };
        img.onerror = function() {
            alert( "not a valid file: " + file.type);
        };
        img.src = _URL.createObjectURL(file);
    }
});

Lastly, change the width and height objects used in the getBase64Image() function by pointing to your input box values

FROM

function getBase64Image(img) {
    var canvas = document.createElement("canvas");
    canvas.width = img.width;
    canvas.height = img.height;

TO

function getBase64Image(img) {
    var canvas = document.createElement("canvas");
    canvas.width = $("#file-w").val();
    canvas.height = $("#file-h").val();

Also, you are going to have to maintain a size of about 300kb for all files. There are posts on stackoverflow that cover file size validation using Javascript.

HTTP headers in Websockets client API

You cannot add headers but, if you just need to pass values to the server at the moment of the connection, you can specify a query string part on the url:

var ws = new WebSocket("ws://example.com/service?key1=value1&key2=value2");

That URL is valid but - of course - you'll need to modify your server code to parse it.

Remove duplicated rows

The data.table package also has unique and duplicated methods of it's own with some additional features.

Both the unique.data.table and the duplicated.data.table methods have an additional by argument which allows you to pass a character or integer vector of column names or their locations respectively

library(data.table)
DT <- data.table(id = c(1,1,1,2,2,2),
                 val = c(10,20,30,10,20,30))

unique(DT, by = "id")
#    id val
# 1:  1  10
# 2:  2  10

duplicated(DT, by = "id")
# [1] FALSE  TRUE  TRUE FALSE  TRUE  TRUE

Another important feature of these methods is a huge performance gain for larger data sets

library(microbenchmark)
library(data.table)
set.seed(123)
DF <- as.data.frame(matrix(sample(1e8, 1e5, replace = TRUE), ncol = 10))
DT <- copy(DF)
setDT(DT)

microbenchmark(unique(DF), unique(DT))
# Unit: microseconds
#       expr       min         lq      mean    median        uq       max neval cld
# unique(DF) 44708.230 48981.8445 53062.536 51573.276 52844.591 107032.18   100   b
# unique(DT)   746.855   776.6145  2201.657   864.932   919.489  55986.88   100  a 


microbenchmark(duplicated(DF), duplicated(DT))
# Unit: microseconds
#           expr       min         lq       mean     median        uq        max neval cld
# duplicated(DF) 43786.662 44418.8005 46684.0602 44925.0230 46802.398 109550.170   100   b
# duplicated(DT)   551.982   558.2215   851.0246   639.9795   663.658   5805.243   100  a 

What's the most efficient way to test two integer ranges for overlap?

Great answer from Simon, but for me it was easier to think about reverse case.

When do 2 ranges not overlap? They don't overlap when one of them starts after the other one ends:

dont_overlap = x2 < y1 || x1 > y2

Now it easy to express when they do overlap:

overlap = !dont_overlap = !(x2 < y1 || x1 > y2) = (x2 >= y1 && x1 <= y2)

How to convert a factor to integer\numeric without loss of information?

You can use hablar::convert if you have a data frame. The syntax is easy:

Sample df

library(hablar)
library(dplyr)

df <- dplyr::tibble(a = as.factor(c("7", "3")),
                    b = as.factor(c("1.5", "6.3")))

Solution

df %>% 
  convert(num(a, b))

gives you:

# A tibble: 2 x 2
      a     b
  <dbl> <dbl>
1    7.  1.50
2    3.  6.30

Or if you want one column to be integer and one numeric:

df %>% 
  convert(int(a),
          num(b))

results in:

# A tibble: 2 x 2
      a     b
  <int> <dbl>
1     7  1.50
2     3  6.30

Why compile Python code?

Pluses:

First: mild, defeatable obfuscation.

Second: if compilation results in a significantly smaller file, you will get faster load times. Nice for the web.

Third: Python can skip the compilation step. Faster at intial load. Nice for the CPU and the web.

Fourth: the more you comment, the smaller the .pyc or .pyo file will be in comparison to the source .py file.

Fifth: an end user with only a .pyc or .pyo file in hand is much less likely to present you with a bug they caused by an un-reverted change they forgot to tell you about.

Sixth: if you're aiming at an embedded system, obtaining a smaller size file to embed may represent a significant plus, and the architecture is stable so drawback one, detailed below, does not come into play.

Top level compilation

It is useful to know that you can compile a top level python source file into a .pyc file this way:

python -m py_compile myscript.py

This removes comments. It leaves docstrings intact. If you'd like to get rid of the docstrings as well (you might want to seriously think about why you're doing that) then compile this way instead...

python -OO -m py_compile myscript.py

...and you'll get a .pyo file instead of a .pyc file; equally distributable in terms of the code's essential functionality, but smaller by the size of the stripped-out docstrings (and less easily understood for subsequent employment if it had decent docstrings in the first place). But see drawback three, below.

Note that python uses the .py file's date, if it is present, to decide whether it should execute the .py file as opposed to the .pyc or .pyo file --- so edit your .py file, and the .pyc or .pyo is obsolete and whatever benefits you gained are lost. You need to recompile it in order to get the .pyc or .pyo benefits back again again, such as they may be.

Drawbacks:

First: There's a "magic cookie" in .pyc and .pyo files that indicates the system architecture that the python file was compiled in. If you distribute one of these files into an environment of a different type, it will break. If you distribute the .pyc or .pyo without the associated .py to recompile or touch so it supersedes the .pyc or .pyo, the end user can't fix it, either.

Second: If docstrings are skipped with the use of the -OO command line option as described above, no one will be able to get at that information, which can make use of the code more difficult (or impossible.)

Third: Python's -OO option also implements some optimizations as per the -O command line option; this may result in changes in operation. Known optimizations are:

  • sys.flags.optimize = 1
  • assert statements are skipped
  • __debug__ = False

Fourth: if you had intentionally made your python script executable with something on the order of #!/usr/bin/python on the first line, this is stripped out in .pyc and .pyo files and that functionality is lost.

Fifth: somewhat obvious, but if you compile your code, not only can its use be impacted, but the potential for others to learn from your work is reduced, often severely.

Convert blob URL to normal URL

Found this answer here and wanted to reference it as it appear much cleaner than the accepted answer:

function blobToDataURL(blob, callback) {
  var fileReader = new FileReader();
  fileReader.onload = function(e) {callback(e.target.result);}
  fileReader.readAsDataURL(blob);
}

How stable is the git plugin for eclipse?

Meanwhile EclipseGit is an "Official Eclipse Technology Project" (09-05-07 GitWiki). I use the current version 0.5.0 (the Wiki is a step behind the development) from time to time, without any problems. Version comparison, commit, revert etc. is working well, although manual refresh's (F5) are necessary when using command line or other Git clients (usual and acceptable Eclipse behavior I think).

How to create a folder with name as current date in batch (.bat) files

I had a problem with this because my server ABSOLUTELY had to have its date in MM/dd/yyyy format, while I wanted the directory to be in YYYY-MM-DD format for neatness sake. Here's how to get it in YYYY-MM-DD format, no matter what your regional settings are set as.

Find out what gets displayed when you use %DATE%:

From a command prompt type:

ECHO %DATE%

Mine came out 03/06/2013 (as in 6th March 2013)

Therefore, to get a directory name as 2013-03-06, code this into your batch file:

SET dirname="%date:~6,4%-%date:~0,2%-%date:~3,2%"
mkdir %dirname%

How to implement OnFragmentInteractionListener

For those of you who still don't understand after reading @meda answer, here is my concise and complete explanation for this issue:

Let's say you have 2 Fragments, Fragment_A and Fragment_B which are auto-generated from the app. On the bottom part of your generated fragments, you're going to find this code:

public class Fragment_A extends Fragment {

    //rest of the code is omitted

    public interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        public void onFragmentInteraction(Uri uri);
    }
}

public class Fragment_B extends Fragment {

    //rest of the code is omitted

    public interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        public void onFragmentInteraction(Uri uri);
    }
}

To overcome the issue, you have to add onFragmentInteraction method into your activity, which in my case is named MainActivity2. After that, you need to implements all fragments in the MainActivity like this:

public class MainActivity2 extends ActionBarActivity
        implements Fragment_A.OnFragmentInteractionListener, 
                   Fragment_B.OnFragmentInteractionListener, 
                   NavigationDrawerFragment.NavigationDrawerCallbacks {
    //rest code is omitted

    @Override
    public void onFragmentInteraction(Uri uri){
        //you can leave it empty
    }
}

P.S.: In short, this method could be used for communicating between fragments. For those of you who want to know more about this method, please refer to this link.

Why is there no SortedList in Java?

JavaFX SortedList

Though it took a while, Java 8 does have a sorted List. http://docs.oracle.com/javase/8/javafx/api/javafx/collections/transformation/SortedList.html

As you can see in the javadocs, it is part of the JavaFX collections, intended to provide a sorted view on an ObservableList.

Update: Note that with Java 11, the JavaFX toolkit has moved outside the JDK and is now a separate library. JavaFX 11 is available as a downloadable SDK or from MavenCentral. See https://openjfx.io

TCP vs UDP on video stream

One of the biggest problems with delivering live events on Internet is 'scale', and TCP doesn’t scale well. For example when you are beaming a live football match -as opposed to an on demand movie playback- the number of people watching can easily be 1000 times more. In such a scenario using TCP is a death sentence for the CDNs (content delivery networks).

There are a couple of main reasons why TCP doesn't scale well:

  1. One of the largest tradeoffs of TCP is the variability of throughput achievable between the sender and the receiver. When streaming video over the Internet the video packets must traverse multiple routers over the Internet, each of these routers is connected with different speed connections. The TCP algorithm starts with TCP window off small, then grows until packet loss is detected, the packet loss is considered a sign of congestion and TCP responds to it by drastically reducing the window size to avoid congestion. Thus in turn reducing the effective throughput immediately. Now imagine a network with TCP transmission using 6-7 router hops to the client (a very normal scenario), if any of the intermediate router looses any packet, the TCP for that link will reduce the transmission rate. In-fact The traffic flow between routers follow an hourglass kind of a shape; always gong up and down in-between one of the intermediate routers. Rendering the effective through put much lower compared to best-effort UDP.

  2. As you may already know TCP is an acknowledgement-based protocol. Lets for example say a sender is 50ms away (i.e. latency btw two points). This would mean time it takes for a packet to be sent to a receiver and receiver to send an acknowledgement would be 100ms; thus maximum throughput possible as compared to UDP based transmission is already halved.

  3. The TCP doesn’t support multicasting or the new emerging standard of multicasting AMT. Which means the CDNs don’t have the opportunity to reduce network traffic by replicating the packets -when many clients are watching the same content. That itself is a big enough reason for CDNs (like Akamai or Level3) to not go with TCP for live streams.

Convert InputStream to BufferedReader

BufferedReader can't wrap an InputStream directly. It wraps another Reader. In this case you'd want to do something like:

BufferedReader br = new BufferedReader(new InputStreamReader(is, "UTF-8"));

How to add minutes to my Date

Work for me DateUtils

//import
import org.apache.commons.lang.time.DateUtils

...

        //Added and removed minutes to increase current range dates
        Date horaInicialCorteEspecial = DateUtils.addMinutes(new Date(corteEspecial.horaInicial.getTime()),-1)
        Date horaFinalCorteEspecial = DateUtils.addMinutes(new Date(corteEspecial.horaFinal.getTime()),1)

How do I check/uncheck all checkboxes with a button using jQuery?

Try This One:

HTML

<input type="checkbox" name="all" id="checkall" />

JavaScript

$('#checkall:checkbox').change(function () {
   if($(this).attr("checked")) $('input:checkbox').attr('checked','checked');
   else $('input:checkbox').removeAttr('checked');
});?

DEMO

Uploading into folder in FTP?

The folder is part of the URL you set when you create request: "ftp://www.contoso.com/test.htm". If you use "ftp://www.contoso.com/wibble/test.htm" then the file will be uploaded to a folder named wibble.

You may need to first use a request with Method = WebRequestMethods.Ftp.MakeDirectory to make the wibble folder if it doesn't already exist.

Read data from a text file using Java

    File file = new File("Path");

    FileReader reader = new FileReader(file);  

    while((ch=reader.read())!=-1)
    {
        System.out.print((char)ch);
    }

This worked for me

How do you represent a JSON array of strings?

Basically yes, JSON is just a javascript literal representation of your value so what you said is correct.

You can find a pretty clear and good explanation of JSON notation on http://json.org/

Setting Action Bar title and subtitle

Try This:

In strings.xml add your title and subtitle...

ActionBar ab = getActionBar();
ab.setTitle(getResources().getString(R.string.myTitle));
ab.setSubtitle(getResources().getString(R.string.mySubTitle));

In Spring MVC, how can I set the mime type header when using @ResponseBody

I would consider to refactor the service to return your domain object rather than JSON strings and let Spring handle the serialization (via the MappingJacksonHttpMessageConverter as you write). As of Spring 3.1, the implementation looks quite neat:

@RequestMapping(produces = MediaType.APPLICATION_JSON_VALUE, 
    method = RequestMethod.GET
    value = "/foo/bar")
@ResponseBody
public Bar fooBar(){
    return myService.getBar();
}

Comments:

First, the <mvc:annotation-driven /> or the @EnableWebMvc must be added to your application config.

Next, the produces attribute of the @RequestMapping annotation is used to specify the content type of the response. Consequently, it should be set to MediaType.APPLICATION_JSON_VALUE (or "application/json").

Lastly, Jackson must be added so that any serialization and de-serialization between Java and JSON will be handled automatically by Spring (the Jackson dependency is detected by Spring and the MappingJacksonHttpMessageConverter will be under the hood).

Change the maximum upload file size

Three things you need to check.

upload_max_filesize, memory_limit and post_max_size in the php.ini configuration file exactly.

All of these three settings limit the maximum size of data that can be submitted and handled by PHP.

Typically post_max_size and memory_limit need to be larger than upload_max_filesize.


So three variables total you need to check to be absolutely sure.

How to use Servlets and Ajax?

The right way to update the page currently displayed in the user's browser (without reloading it) is to have some code executing in the browser update the page's DOM.

That code is typically javascript that is embedded in or linked from the HTML page, hence the AJAX suggestion. (In fact, if we assume that the updated text comes from the server via an HTTP request, this is classic AJAX.)

It is also possible to implement this kind of thing using some browser plugin or add-on, though it may be tricky for a plugin to reach into the browser's data structures to update the DOM. (Native code plugins normally write to some graphics frame that is embedded in the page.)

Check if string doesn't contain another string

Use this as your WHERE condition

WHERE CHARINDEX('Apples', column) = 0 

Spring cron expression for every day 1:01:am

One thing i've noticed is: spring CronTrigger is not cron. You may end up with 7 parameters in a valid cron expression (wich you can validate on cronmaker.com) and then spring not accept it. Most of cases you just delete the last parameter and everything works fine.

SQL MAX of multiple columns?

I do not know if it is on SQL, etc... on M$ACCESS help there is a function called MAXA(Value1;Value2;...) that is supposed to do such.

Hope can help someone.

P.D.: Values can be columns or calculated ones, etc.

Get paragraph text inside an element

HTML:

<ul>
  <li onclick="myfunction(this)">
    <span></span>
    <p>This Text</p>
  </li>
</ul>?

JavaScript:

function myfunction(foo) {
    var elem = foo.getElementsByTagName('p');
    var TextInsideLi = elem[0].innerHTML;
}?

Get underlined text with Markdown

You can wrote **_bold and italic_** and re-style it to underlined text, like this:

strong>em,
em>strong,
b>i,
i>b {
    font-style:normal;
    font-weight:normal;
    text-decoration:underline;
}

Is there a simple way that I can sort characters in a string in alphabetical order

You can use LINQ:

String.Concat(str.OrderBy(c => c))

If you want to remove duplicates, add .Distinct().

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

This is a "problem" on the client side, not really an Oracle problem.

It's the client application which formats and displays the date this way.

In your case it's SQL*Plus which does this formatting.
Other SQL clients have other defaults.

XSLT string replace

I keep hitting this answer. But none of them list the easiest solution for xsltproc (and probably most XSLT 1.0 processors):

  1. Add the exslt strings name to the stylesheet, i.e.:
<xsl:stylesheet
  version="1.0"
  xmlns:str="http://exslt.org/strings"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  1. Then use it like:
<xsl:value-of select="str:replace(., ' ', '')"/>

What's the difference between an element and a node in XML?

The Node object is the primary data type for the entire DOM.

A node can be an element node, an attribute node, a text node, or any other of the node types explained in the "Node types" chapter.

An XML element is everything from (including) the element's start tag to (including) the element's end tag.

Remove querystring from URL

If you're into RegEx....

var newURL = testURL.match(new RegExp("[^?]+"))

In-place edits with sed on OS X

You can use the -i flag correctly by providing it with a suffix to add to the backed-up file. Extending your example:

sed -i.bu 's/oldword/newword/' file1.txt

Will give you two files: one with the name file1.txt that contains the substitution, and one with the name file1.txt.bu that has the original content.

Mildly dangerous

If you want to destructively overwrite the original file, use something like:

sed -i '' 's/oldword/newword/' file1.txt
      ^ note the space

Because of the way the line gets parsed, a space is required between the option flag and its argument because the argument is zero-length.

Other than possibly trashing your original, I’m not aware of any further dangers of tricking sed this way. It should be noted, however, that if this invocation of sed is part of a script, The Unix Way™ would (IMHO) be to use sed non-destructively, test that it exited cleanly, and only then remove the extraneous file.

How to recover deleted rows from SQL server table?

You have Full data + Transaction log backups, right? You can restore to another Database from backups and then sync the deleted rows back. Lots of work though...

(Have you looked at Redgate's SQL Log Rescue? Update: it's SQL Server 2000 only)

There is Log Explorer

How do I output text without a newline in PowerShell?

You can absolutely do this. Write-Output has a flag called "NoEnumerate" that is essentially the same thing.

Change Screen Orientation programmatically using a Button

A working code:

private void changeScreenOrientation() {
    int orientation = yourActivityName.this.getResources().getConfiguration().orientation;
    if (orientation == Configuration.ORIENTATION_LANDSCAPE) {
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        showMediaDescription();
    } else {
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
        hideMediaDescription();
    }
    if (Settings.System.getInt(getContentResolver(),
            Settings.System.ACCELEROMETER_ROTATION, 0) == 1) {
        Handler handler = new Handler();
        handler.postDelayed(new Runnable() {
            @Override
            public void run() {
                setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR);
            }
        }, 4000);
    }
}

call this method in your button click

HTML: How to center align a form

Try this : Set the width of the form as 20% by:
width : 20%;
now if the entire canvas is 100 %, the centre is at 50%. So to align the centre of the form at the centre, 50-(20/2) = 40. therefore set your left margin as 40% by doing this :
left : 40%;

How to test if a string is JSON or not?

In addition to previous answers, in case of you need to validate a JSON format like "{}", you can use the following code:

const validateJSON = (str) => {
  try {
    const json = JSON.parse(str);
    if (Object.prototype.toString.call(json).slice(8,-1) !== 'Object') {
      return false;
    }
  } catch (e) {
    return false;
  }
  return true;
}

Examples of usage:

validateJSON('{}')
true
validateJSON('[]')
false
validateJSON('')
false
validateJSON('2134')
false
validateJSON('{ "Id": 1, "Name": "Coke" }')
true

Converting time stamps in excel to dates

Use this simple formula. It works.

Suppose time stamp in A2:

=DATE(YEAR(A2),MONTH(A2),DAY(A2))

Explode string by one or more spaces or tabs

$parts = preg_split('/\s+/', $str);

How to get substring in C

char originalString[] = "THESTRINGHASNOSPACES";

    char aux[5];
    int j=0;
    for(int i=0;i<strlen(originalString);i++){
        aux[j] = originalString[i];
        if(j==3){
            aux[j+1]='\0'; 
            printf("%s\n",aux);
            j=0;
        }else{
            j++;
        }
    }

Min width in window resizing

You can set min-width property of CSS for body tag. Since this property is not supported by IE6, you can write like:

body{
   min-width:1000px;        /* Suppose you want minimum width of 1000px */
   width: auto !important;  /* Firefox will set width as auto */
   width:1000px;            /* As IE6 ignores !important it will set width as 1000px; */
}

Or:

body{
   min-width:1000px; // Suppose you want minimum width of 1000px
   _width: expression( document.body.clientWidth > 1000 ? "1000px" : "auto" ); /* sets max-width for IE6 */
}

Run javascript script (.js file) in mongodb including another file inside js

Use Load function

load(filename)

You can directly call any .js file from the mongo shell, and mongo will execute the JavaScript.

Example : mongo localhost:27017/mydb myfile.js

This executes the myfile.js script in mongo shell connecting to mydb database with port 27017 in localhost.

For loading external js you can write

load("/data/db/scripts/myloadjs.js")

Suppose we have two js file myFileOne.js and myFileTwo.js

myFileOne.js

print('From file 1');
load('myFileTwo.js');     // Load other js file .

myFileTwo.js

print('From file 2');

MongoShell

>mongo myFileOne.js

Output

From file 1
From file 2

How to search multiple columns in MySQL?

If your table is MyISAM:

SELECT  *
FROM    pages
WHERE   MATCH(title, content) AGAINST ('keyword' IN BOOLEAN MODE)

This will be much faster if you create a FULLTEXT index on your columns:

CREATE FULLTEXT INDEX fx_pages_title_content ON pages (title, content)

, but will work even without the index.

JSON to string variable dump

You can use console.log() in Firebug or Chrome to get a good object view here, like this:

$.getJSON('my.json', function(data) {
  console.log(data);
});

If you just want to view the string, look at the Resource view in Chrome or the Net view in Firebug to see the actual string response from the server (no need to convert it...you received it this way).

If you want to take that string and break it down for easy viewing, there's an excellent tool here: http://json.parser.online.fr/

How to delete Certain Characters in a excel 2010 cell

If [John Smith] is in cell A1, then use this formula to do what you want:

=SUBSTITUTE(SUBSTITUTE(A1, "[", ""), "]", "")

The inner SUBSTITUTE replaces all instances of "[" with "" and returns a new string, then the other SUBSTITUTE replaces all instances of "]" with "" and returns the final result.

How to create image slideshow in html?

Instead of writing the code from the scratch you can use jquery plug in. Such plug in can provide many configuration option as well.

Here is the one I most liked.

http://www.zurb.com/playground/orbit-jquery-image-slider

Get remote registry value

If you need user's SID and browse remote HKEY_USERS folder, you can follow this script :

<# Replace following domain.name with yours and userAccountName with remote username #>
$userLogin = New-Object System.Security.Principal.NTAccount(“domain.name“,”userAccountName“)
$userSID = $userLogin.Translate([System.Security.Principal.SecurityIdentifier])

<# We will open HKEY_USERS and with accurate user’s SID from remoteComputer #>
$remoteRegistry = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey(‘Users’,”remoteComputer“)

<# We will then retrieve LocalName value from Control Panel / International subkeys #>

$key = $userSID.value+”\Control Panel\International”
$openKey = $remoteRegistry.OpenSubKey($key)

<# We can now retrieve any values #>

$localName = $openKey.GetValue(‘LocaleName’)

Source : http://techsultan.com/how-to-browse-remote-registry-in-powershell/

optional parameters in SQL Server stored proc?

You can declare like this

CREATE PROCEDURE MyProcName
    @Parameter1 INT = 1,
    @Parameter2 VARCHAR (100) = 'StringValue',
    @Parameter3 VARCHAR (100) = NULL
AS

/* check for the NULL / default value (indicating nothing was passed */
if (@Parameter3 IS NULL)
BEGIN
    /* whatever code you desire for a missing parameter*/
    INSERT INTO ........
END

/* and use it in the query as so*/
SELECT *
FROM Table
WHERE Column = @Parameter

How to write to file in Ruby?

For those of us that learn by example...

Write text to a file like this:

IO.write('/tmp/msg.txt', 'hi')

BONUS INFO ...

Read it back like this

IO.read('/tmp/msg.txt')

Frequently, I want to read a file into my clipboard ***

Clipboard.copy IO.read('/tmp/msg.txt')

And other times, I want to write what's in my clipboard to a file ***

IO.write('/tmp/msg.txt', Clipboard.paste)

*** Assumes you have the clipboard gem installed

See: https://rubygems.org/gems/clipboard

Authentication failed because remote party has closed the transport stream

using (var client = new HttpClient(handler))
            {
                ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;
                var response = await client.SendAsync(new HttpRequestMessage(HttpMethod.Get, apiEndPoint)).ConfigureAwait(false);
                await response.Content.ReadAsStringAsync().ConfigureAwait(false);
            }

This worked for me

How to find an object in an ArrayList by property

Here is another solution using Guava in Java 8 that returns the matched element if one exists in the list. If more than one elements are matched then the collector throws an IllegalArgumentException. A null is returned if there is no match.

Carnet carnet = listCarnet.stream()
                    .filter(c -> c.getCodeIsin().equals(wantedCodeIsin))
                    .collect(MoreCollectors.toOptional())
                    .orElse(null);

SELECT CONVERT(VARCHAR(10), GETDATE(), 110) what is the meaning of 110 here?

That number indicates Date and Time Styles

You need to look at CAST and CONVERT (Transact-SQL). Here you can find the meaning of all these Date and Time Styles.

Styles with century (e.g. 100, 101 etc) means year will come in yyyy format. While styles without century (e.g. 1,7,10) means year will come in yy format.

You can also refer to SQL Server Date Formats. Here you can find all date formats with examples.

WebForms UnobtrusiveValidationMode requires a ScriptResourceMapping for 'jquery'. Please add a ScriptResourceMapping named jquery(case-sensitive)

I believe I have encountered the same quandary. I started encountering the problem when I changed to:

</system.web>
<httpRuntime targetFramework="4.5"/>

Which gives the error message you describe above.

adding:

<appSettings>
  <add key="ValidationSettings:UnobtrusiveValidationMode" value="None" />

Solves the issue, but then it makes your validation controls/scripts throw Javascript runtime errors. If you change to:

</system.web>
<httpRuntime targetFramework="4.0"/>

You should be OK, but you’ll have to make sure the rest of your code does/ behaves as desired. You might also have to forgo some new features only available in 4.5 onward.

P.S. It is highly recommended that you read the following before implementing this solution. Especially, if you use Async functionality:

https://blogs.msdn.microsoft.com/webdev/2012/11/19/all-about-httpruntime-targetframework/

UPDATE April 2017: After some some experimentation and testing I have come up with a combination that works:

<add key="ValidationSettings:UnobtrusiveValidationMode" value="None" />
<httpRuntime targetFramework="4.5.1" />

with:

jQuery version 1.11.3

How to call code behind server method from a client side JavaScript function?

JS Code:

<script type="text/javascript">
         function ShowCurrentTime(name) {
         PageMethods.GetCurrentTime(name, OnSuccess);
         }
         function OnSuccess(response, userContext, methodName) {
          alert(response);
         }
</script>

HTML Code:

<asp:ImageButton ID="IMGBTN001" runat="server" ImageUrl="Images/ico/labaniat.png"
class="img-responsive em-img-lazy" OnClientClick="ShowCurrentTime('01')" />

Code Behind C#

[System.Web.Services.WebMethod]
public static string GetCurrentTime(string name)
{
    return "Hello " + name + Environment.NewLine + "The Current Time is: "
            + DateTime.Now.ToString();
}

How to convert DOS/Windows newline (CRLF) to Unix newline (LF) in a Bash script?

Had just to ponder that same question (on Windows-side, but equally applicable to linux.) Suprisingly nobody mentioned a very much automated way of doing CRLF<->LF conversion for text-files using good old zip -ll option (Info-ZIP):

zip -ll textfiles-lf.zip files-with-crlf-eol.*
unzip textfiles-lf.zip 

NOTE: this would create a zip file preserving the original file names but converting the line endings to LF. Then unzip would extract the files as zip'ed, that is with their original names (but with LF-endings), thus prompting to overwrite the local original files if any.

Relevant excerpt from the zip --help:

zip --help
...
-l   convert LF to CR LF (-ll CR LF to LF)

Simplest way to detect a mobile device in PHP

I was wondering, until now, why someone had not posted a slightly alteration of the accepted answer to the use of implode() in order to have a better readability of the code. So here it goes:

<?php
$uaFull = strtolower($_SERVER['HTTP_USER_AGENT']);
$uaStart = substr($uaFull, 0, 4);

$uaPhone = [
    '(android|bb\d+|meego).+mobile',
    'avantgo',
    'bada\/',
    'blackberry',
    'blazer',
    'compal',
    'elaine',
    'fennec',
    'hiptop',
    'iemobile',
    'ip(hone|od)',
    'iris',
    'kindle',
    'lge ',
    'maemo',
    'midp',
    'mmp',
    'mobile.+firefox',
    'netfront',
    'opera m(ob|in)i',
    'palm( os)?',
    'phone',
    'p(ixi|re)\/',
    'plucker',
    'pocket',
    'psp',
    'series(4|6)0',
    'symbian',
    'treo',
    'up\.(browser|link)',
    'vodafone',
    'wap',
    'windows ce',
    'xda',
    'xiino'
];

$uaMobile = [
    '1207', 
    '6310', 
    '6590', 
    '3gso', 
    '4thp', 
    '50[1-6]i', 
    '770s', 
    '802s', 
    'a wa', 
    'abac|ac(er|oo|s\-)', 
    'ai(ko|rn)', 
    'al(av|ca|co)', 
    'amoi', 
    'an(ex|ny|yw)', 
    'aptu', 
    'ar(ch|go)', 
    'as(te|us)', 
    'attw', 
    'au(di|\-m|r |s )', 
    'avan', 
    'be(ck|ll|nq)', 
    'bi(lb|rd)', 
    'bl(ac|az)', 
    'br(e|v)w', 
    'bumb', 
    'bw\-(n|u)', 
    'c55\/', 
    'capi', 
    'ccwa', 
    'cdm\-', 
    'cell', 
    'chtm', 
    'cldc', 
    'cmd\-', 
    'co(mp|nd)', 
    'craw', 
    'da(it|ll|ng)', 
    'dbte', 
    'dc\-s', 
    'devi', 
    'dica', 
    'dmob', 
    'do(c|p)o', 
    'ds(12|\-d)', 
    'el(49|ai)', 
    'em(l2|ul)', 
    'er(ic|k0)', 
    'esl8', 
    'ez([4-7]0|os|wa|ze)', 
    'fetc', 
    'fly(\-|_)', 
    'g1 u', 
    'g560', 
    'gene', 
    'gf\-5', 
    'g\-mo', 
    'go(\.w|od)', 
    'gr(ad|un)', 
    'haie', 
    'hcit', 
    'hd\-(m|p|t)', 
    'hei\-', 
    'hi(pt|ta)', 
    'hp( i|ip)', 
    'hs\-c', 
    'ht(c(\-| |_|a|g|p|s|t)|tp)', 
    'hu(aw|tc)', 
    'i\-(20|go|ma)', 
    'i230', 
    'iac( |\-|\/)', 
    'ibro', 
    'idea', 
    'ig01', 
    'ikom', 
    'im1k', 
    'inno', 
    'ipaq', 
    'iris', 
    'ja(t|v)a', 
    'jbro', 
    'jemu', 
    'jigs', 
    'kddi', 
    'keji', 
    'kgt( |\/)', 
    'klon', 
    'kpt ', 
    'kwc\-', 
    'kyo(c|k)', 
    'le(no|xi)', 
    'lg( g|\/(k|l|u)|50|54|\-[a-w])', 
    'libw', 
    'lynx', 
    'm1\-w', 
    'm3ga', 
    'm50\/', 
    'ma(te|ui|xo)', 
    'mc(01|21|ca)', 
    'm\-cr', 
    'me(rc|ri)', 
    'mi(o8|oa|ts)', 
    'mmef', 
    'mo(01|02|bi|de|do|t(\-| |o|v)|zz)', 
    'mt(50|p1|v )', 
    'mwbp', 
    'mywa', 
    'n10[0-2]', 
    'n20[2-3]', 
    'n30(0|2)', 
    'n50(0|2|5)', 
    'n7(0(0|1)|10)', 
    'ne((c|m)\-|on|tf|wf|wg|wt)', 
    'nok(6|i)', 
    'nzph', 
    'o2im', 
    'op(ti|wv)', 
    'oran', 
    'owg1', 
    'p800', 
    'pan(a|d|t)', 
    'pdxg', 
    'pg(13|\-([1-8]|c))', 
    'phil', 
    'pire', 
    'pl(ay|uc)', 
    'pn\-2', 
    'po(ck|rt|se)', 
    'prox', 
    'psio', 
    'pt\-g', 
    'qa\-a', 
    'qc(07|12|21|32|60|\-[2-7]|i\-)', 
    'qtek', 
    'r380', 
    'r600', 
    'raks', 
    'rim9', 
    'ro(ve|zo)', 
    's55\/', 
    'sa(ge|ma|mm|ms|ny|va)', 
    'sc(01|h\-|oo|p\-)', 
    'sdk\/', 
    'se(c(\-|0|1)|47|mc|nd|ri)', 
    'sgh\-', 
    'shar', 
    'sie(\-|m)', 
    'sk\-0', 
    'sl(45|id)', 
    'sm(al|ar|b3|it|t5)', 
    'so(ft|ny)', 
    'sp(01|h\-|v\-|v )', 
    'sy(01|mb)', 
    't2(18|50)', 
    't6(00|10|18)', 
    'ta(gt|lk)', 
    'tcl\-', 
    'tdg\-', 
    'tel(i|m)', 
    'tim\-', 
    't\-mo', 
    'to(pl|sh)', 
    'ts(70|m\-|m3|m5)', 
    'tx\-9', 
    'up(\.b|g1|si)', 
    'utst', 
    'v400', 
    'v750', 
    'veri', 
    'vi(rg|te)', 
    'vk(40|5[0-3]|\-v)', 
    'vm40', 
    'voda', 
    'vulc', 
    'vx(52|53|60|61|70|80|81|83|85|98)', 
    'w3c(\-| )', 
    'webc', 
    'whit', 
    'wi(g |nc|nw)', 
    'wmlb', 
    'wonu', 
    'x700', 
    'yas\-', 
    'your', 
    'zeto', 
    'zte\-'
];

$isPhone = preg_match('/' . implode($uaPhone, '|') . '/i', $uaFull);
$isMobile = preg_match('/' . implode($uaMobile, '|') . '/i', $uaStart);

if($isPhone || $isMobile) {
    // do something with that device
} else {
    // process normally
}

Accessing private member variables from prototype-defined functions

@Kai

That won't work. If you do

var t2 = new TestClass();

then t2.prototypeHello will be accessing t's private section.

@AnglesCrimes

The sample code works fine, but it actually creates a "static" private member shared by all instances. It may not be the solution morgancodes looked for.

So far I haven't found an easy and clean way to do this without introducing a private hash and extra cleanup functions. A private member function can be simulated to certain extent:

(function() {
    function Foo() { ... }
    Foo.prototype.bar = function() {
       privateFoo.call(this, blah);
    };
    function privateFoo(blah) { 
        // scoped to the instance by passing this to call 
    }

    window.Foo = Foo;
}());

How can I find the OWNER of an object in Oracle?

Oracle views like ALL_TABLES and ALL_CONSTRAINTS have an owner column, which you can use to restrict your query. There are also variants of these tables beginning with USER instead of ALL, which only list objects which can be accessed by the current user.

One of these views should help to solve your problem. They always worked fine for me for similar problems.

Extract the first word of a string in a SQL Server query

Enhancement of Ben Brandt's answer to compensate even if the string starts with space by applying LTRIM(). Tried to edit his answer but rejected, so I am now posting it here separately.

DECLARE @test NVARCHAR(255)
SET @test = 'First Second'

SELECT SUBSTRING(LTRIM(@test),1,(CHARINDEX(' ',LTRIM(@test) + ' ')-1))

JFrame in full screen Java

JFrame frame = new JFrame();
frame.setPreferredSize(new Dimension(Toolkit.getDefaultToolkit().getScreenSize()));

This just makes the frame the size of the screen

What languages are Windows, Mac OS X and Linux written in?

You're right MacOSX has Objective-C in the core.

Windows C++

Linux C

About the scripting languages, no, they pretty much high level.

Installing NumPy via Anaconda in Windows

Anaconda folder basically resides in C:\Users\\Anaconda. Try setting the PATH to this folder.

How do I use arrays in C++?

5. Common pitfalls when using arrays.

5.1 Pitfall: Trusting type-unsafe linking.

OK, you’ve been told, or have found out yourself, that globals (namespace scope variables that can be accessed outside the translation unit) are Evil™. But did you know how truly Evil™ they are? Consider the program below, consisting of two files [main.cpp] and [numbers.cpp]:

// [main.cpp]
#include <iostream>

extern int* numbers;

int main()
{
    using namespace std;
    for( int i = 0;  i < 42;  ++i )
    {
        cout << (i > 0? ", " : "") << numbers[i];
    }
    cout << endl;
}

// [numbers.cpp]
int numbers[42] = {1, 2, 3, 4, 5, 6, 7, 8, 9};

In Windows 7 this compiles and links fine with both MinGW g++ 4.4.1 and Visual C++ 10.0.

Since the types don't match, the program crashes when you run it.

The Windows 7 crash dialog

In-the-formal explanation: the program has Undefined Behavior (UB), and instead of crashing it can therefore just hang, or perhaps do nothing, or it can send threating e-mails to the presidents of the USA, Russia, India, China and Switzerland, and make Nasal Daemons fly out of your nose.

In-practice explanation: in main.cpp the array is treated as a pointer, placed at the same address as the array. For 32-bit executable this means that the first int value in the array, is treated as a pointer. I.e., in main.cpp the numbers variable contains, or appears to contain, (int*)1. This causes the program to access memory down at very bottom of the address space, which is conventionally reserved and trap-causing. Result: you get a crash.

The compilers are fully within their rights to not diagnose this error, because C++11 §3.5/10 says, about the requirement of compatible types for the declarations,

[N3290 §3.5/10]
A violation of this rule on type identity does not require a diagnostic.

The same paragraph details the variation that is allowed:

… declarations for an array object can specify array types that differ by the presence or absence of a major array bound (8.3.4).

This allowed variation does not include declaring a name as an array in one translation unit, and as a pointer in another translation unit.

5.2 Pitfall: Doing premature optimization (memset & friends).

Not written yet

5.3 Pitfall: Using the C idiom to get number of elements.

With deep C experience it’s natural to write …

#define N_ITEMS( array )   (sizeof( array )/sizeof( array[0] ))

Since an array decays to pointer to first element where needed, the expression sizeof(a)/sizeof(a[0]) can also be written as sizeof(a)/sizeof(*a). It means the same, and no matter how it’s written it is the C idiom for finding the number elements of array.

Main pitfall: the C idiom is not typesafe. For example, the code …

#include <stdio.h>

#define N_ITEMS( array ) (sizeof( array )/sizeof( *array ))

void display( int const a[7] )
{
    int const   n = N_ITEMS( a );          // Oops.
    printf( "%d elements.\n", n );
}

int main()
{
    int const   moohaha[]   = {1, 2, 3, 4, 5, 6, 7};

    printf( "%d elements, calling display...\n", N_ITEMS( moohaha ) );
    display( moohaha );
}

passes a pointer to N_ITEMS, and therefore most likely produces a wrong result. Compiled as a 32-bit executable in Windows 7 it produces …

7 elements, calling display...
1 elements.

  1. The compiler rewrites int const a[7] to just int const a[].
  2. The compiler rewrites int const a[] to int const* a.
  3. N_ITEMS is therefore invoked with a pointer.
  4. For a 32-bit executable sizeof(array) (size of a pointer) is then 4.
  5. sizeof(*array) is equivalent to sizeof(int), which for a 32-bit executable is also 4.

In order to detect this error at run time you can do …

#include <assert.h>
#include <typeinfo>

#define N_ITEMS( array )       (                               \
    assert((                                                    \
        "N_ITEMS requires an actual array as argument",        \
        typeid( array ) != typeid( &*array )                    \
        )),                                                     \
    sizeof( array )/sizeof( *array )                            \
    )

7 elements, calling display...
Assertion failed: ( "N_ITEMS requires an actual array as argument", typeid( a ) != typeid( &*a ) ), file runtime_detect ion.cpp, line 16

This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.

The runtime error detection is better than no detection, but it wastes a little processor time, and perhaps much more programmer time. Better with detection at compile time! And if you're happy to not support arrays of local types with C++98, then you can do that:

#include <stddef.h>

typedef ptrdiff_t   Size;

template< class Type, Size n >
Size n_items( Type (&)[n] ) { return n; }

#define N_ITEMS( array )       n_items( array )

Compiling this definition substituted into the first complete program, with g++, I got …

M:\count> g++ compile_time_detection.cpp
compile_time_detection.cpp: In function 'void display(const int*)':
compile_time_detection.cpp:14: error: no matching function for call to 'n_items(const int*&)'

M:\count> _

How it works: the array is passed by reference to n_items, and so it does not decay to pointer to first element, and the function can just return the number of elements specified by the type.

With C++11 you can use this also for arrays of local type, and it's the type safe C++ idiom for finding the number of elements of an array.

5.4 C++11 & C++14 pitfall: Using a constexpr array size function.

With C++11 and later it's natural, but as you'll see dangerous!, to replace the C++03 function

typedef ptrdiff_t   Size;

template< class Type, Size n >
Size n_items( Type (&)[n] ) { return n; }

with

using Size = ptrdiff_t;

template< class Type, Size n >
constexpr auto n_items( Type (&)[n] ) -> Size { return n; }

where the significant change is the use of constexpr, which allows this function to produce a compile time constant.

For example, in contrast to the C++03 function, such a compile time constant can be used to declare an array of the same size as another:

// Example 1
void foo()
{
    int const x[] = {3, 1, 4, 1, 5, 9, 2, 6, 5, 4};
    constexpr Size n = n_items( x );
    int y[n] = {};
    // Using y here.
}

But consider this code using the constexpr version:

// Example 2
template< class Collection >
void foo( Collection const& c )
{
    constexpr int n = n_items( c );     // Not in C++14!
    // Use c here
}

auto main() -> int
{
    int x[42];
    foo( x );
}

The pitfall: as of July 2015 the above compiles with MinGW-64 5.1.0 with -pedantic-errors, and, testing with the online compilers at gcc.godbolt.org/, also with clang 3.0 and clang 3.2, but not with clang 3.3, 3.4.1, 3.5.0, 3.5.1, 3.6 (rc1) or 3.7 (experimental). And important for the Windows platform, it does not compile with Visual C++ 2015. The reason is a C++11/C++14 statement about use of references in constexpr expressions:

C++11 C++14 $5.19/2 nineth dash

A conditional-expression e is a core constant expression unless the evaluation of e, following the rules of the abstract machine (1.9), would evaluate one of the following expressions:
        ?

  • an id-expression that refers to a variable or data member of reference type unless the reference has a preceding initialization and either
    • it is initialized with a constant expression or
    • it is a non-static data member of an object whose lifetime began within the evaluation of e;

One can always write the more verbose

// Example 3  --  limited

using Size = ptrdiff_t;

template< class Collection >
void foo( Collection const& c )
{
    constexpr Size n = std::extent< decltype( c ) >::value;
    // Use c here
}

… but this fails when Collection is not a raw array.

To deal with collections that can be non-arrays one needs the overloadability of an n_items function, but also, for compile time use one needs a compile time representation of the array size. And the classic C++03 solution, which works fine also in C++11 and C++14, is to let the function report its result not as a value but via its function result type. For example like this:

// Example 4 - OK (not ideal, but portable and safe)

#include <array>
#include <stddef.h>

using Size = ptrdiff_t;

template< Size n >
struct Size_carrier
{
    char sizer[n];
};

template< class Type, Size n >
auto static_n_items( Type (&)[n] )
    -> Size_carrier<n>;
// No implementation, is used only at compile time.

template< class Type, size_t n >        // size_t for g++
auto static_n_items( std::array<Type, n> const& )
    -> Size_carrier<n>;
// No implementation, is used only at compile time.

#define STATIC_N_ITEMS( c ) \
    static_cast<Size>( sizeof( static_n_items( c ).sizer ) )

template< class Collection >
void foo( Collection const& c )
{
    constexpr Size n = STATIC_N_ITEMS( c );
    // Use c here
    (void) c;
}

auto main() -> int
{
    int x[42];
    std::array<int, 43> y;
    foo( x );
    foo( y );
}

About the choice of return type for static_n_items: this code doesn't use std::integral_constant because with std::integral_constant the result is represented directly as a constexpr value, reintroducing the original problem. Instead of a Size_carrier class one can let the function directly return a reference to an array. However, not everybody is familiar with that syntax.

About the naming: part of this solution to the constexpr-invalid-due-to-reference problem is to make the choice of compile time constant explicit.

Hopefully the oops-there-was-a-reference-involved-in-your-constexpr issue will be fixed with C++17, but until then a macro like the STATIC_N_ITEMS above yields portability, e.g. to the clang and Visual C++ compilers, retaining type safety.

Related: macros do not respect scopes, so to avoid name collisions it can be a good idea to use a name prefix, e.g. MYLIB_STATIC_N_ITEMS.

See changes to a specific file using git

Another method (mentioned in this SO answer) will keep the history in the terminal and give you a very deep track record of the file itself:

git log --follow -p -- file

This will show the entire history of the file (including history beyond renames and with diffs for each change).

In other words, if the file named bar was once named foo, then git log -p bar (without the --follow option) will only show the file's history up to the point where it was renamed -- it won't show the file's history when it was known as foo. Using git log --follow -p bar will show the file's entire history, including any changes to the file when it was known as foo.

Resize UIImage and change the size of UIImageView

Use the category below and then apply border from Quartz into your image:

[yourimage.layer setBorderColor:[[UIColor whiteColor] CGColor]];
[yourimage.layer setBorderWidth:2];

The category: UIImage+AutoScaleResize.h

#import <Foundation/Foundation.h>

@interface UIImage (AutoScaleResize)

- (UIImage *)imageByScalingAndCroppingForSize:(CGSize)targetSize;

@end

UIImage+AutoScaleResize.m

#import "UIImage+AutoScaleResize.h"

@implementation UIImage (AutoScaleResize)

- (UIImage *)imageByScalingAndCroppingForSize:(CGSize)targetSize
{
    UIImage *sourceImage = self;
    UIImage *newImage = nil;
    CGSize imageSize = sourceImage.size;
    CGFloat width = imageSize.width;
    CGFloat height = imageSize.height;
    CGFloat targetWidth = targetSize.width;
    CGFloat targetHeight = targetSize.height;
    CGFloat scaleFactor = 0.0;
    CGFloat scaledWidth = targetWidth;
    CGFloat scaledHeight = targetHeight;
    CGPoint thumbnailPoint = CGPointMake(0.0,0.0);

    if (CGSizeEqualToSize(imageSize, targetSize) == NO)
    {
        CGFloat widthFactor = targetWidth / width;
        CGFloat heightFactor = targetHeight / height;

        if (widthFactor > heightFactor)
        {
            scaleFactor = widthFactor; // scale to fit height
        }
        else
        {
            scaleFactor = heightFactor; // scale to fit width
        }

        scaledWidth  = width * scaleFactor;
        scaledHeight = height * scaleFactor;

        // center the image
        if (widthFactor > heightFactor)
        {
            thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
        }
        else
        {
            if (widthFactor < heightFactor)
            {
                thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
            }
        }
    }

    UIGraphicsBeginImageContext(targetSize); // this will crop

    CGRect thumbnailRect = CGRectZero;
    thumbnailRect.origin = thumbnailPoint;
    thumbnailRect.size.width  = scaledWidth;
    thumbnailRect.size.height = scaledHeight;

    [sourceImage drawInRect:thumbnailRect];

    newImage = UIGraphicsGetImageFromCurrentImageContext();

    if(newImage == nil)
    {
        NSLog(@"could not scale image");
    }

    //pop the context to get back to the default
    UIGraphicsEndImageContext();

    return newImage;
}

@end

Format a BigDecimal as String with max 2 decimal digits, removing 0 on decimal part

I used DecimalFormat for formatting the BigDecimal instead of formatting the String, seems no problems with it.

The code is something like this:

bd = bd.setScale(2, BigDecimal.ROUND_DOWN);

DecimalFormat df = new DecimalFormat();

df.setMaximumFractionDigits(2);

df.setMinimumFractionDigits(0);

df.setGroupingUsed(false);

String result = df.format(bd);

How can I determine the direction of a jQuery scroll event?

This is simple and easy detection for when the user scrolls away from the top of the page and for when they return to the top.

$(window).scroll(function() {
    if($(window).scrollTop() > 0) {
        // User has scrolled
    } else {
        // User at top of page
    }
});

How to remove a key from Hash and get the remaining hash in Ruby/Rails?

Oneliner plain ruby, it works only with ruby > 1.9.x:

1.9.3p0 :002 > h = {:a => 1, :b => 2}
 => {:a=>1, :b=>2} 
1.9.3p0 :003 > h.tap { |hs| hs.delete(:a) }
 => {:b=>2} 

Tap method always return the object on which is invoked...

Otherwise if you have required active_support/core_ext/hash (which is automatically required in every Rails application) you can use one of the following methods depending on your needs:

?  ~  irb
1.9.3p125 :001 > require 'active_support/core_ext/hash' => true 
1.9.3p125 :002 > h = {:a => 1, :b => 2, :c => 3}
 => {:a=>1, :b=>2, :c=>3} 
1.9.3p125 :003 > h.except(:a)
 => {:b=>2, :c=>3} 
1.9.3p125 :004 > h.slice(:a)
 => {:a=>1} 

except uses a blacklist approach, so it removes all the keys listed as args, while slice uses a whitelist approach, so it removes all keys that aren't listed as arguments. There also exist the bang version of those method (except! and slice!) which modify the given hash but their return value is different both of them return an hash. It represents the removed keys for slice! and the keys that are kept for the except!:

1.9.3p125 :011 > {:a => 1, :b => 2, :c => 3}.except!(:a)
 => {:b=>2, :c=>3} 
1.9.3p125 :012 > {:a => 1, :b => 2, :c => 3}.slice!(:a)
 => {:b=>2, :c=>3} 

Calling a JSON API with Node.js

Problems with other answers:

  • unsafe JSON.parse
  • no response code checking

All of the answers here use JSON.parse() in an unsafe way. You should always put all calls to JSON.parse() in a try/catch block especially when you parse JSON coming from an external source, like you do here.

You can use request to parse the JSON automatically which wasn't mentioned here in other answers. There is already an answer using request module but it uses JSON.parse() to manually parse JSON - which should always be run inside a try {} catch {} block to handle errors of incorrect JSON or otherwise the entire app will crash. And incorrect JSON happens, trust me.

Other answers that use http also use JSON.parse() without checking for exceptions that can happen and crash your application.

Below I'll show few ways to handle it safely.

All examples use a public GitHub API so everyone can try that code safely.

Example with request

Here's a working example with request that automatically parses JSON:

'use strict';
var request = require('request');

var url = 'https://api.github.com/users/rsp';

request.get({
    url: url,
    json: true,
    headers: {'User-Agent': 'request'}
  }, (err, res, data) => {
    if (err) {
      console.log('Error:', err);
    } else if (res.statusCode !== 200) {
      console.log('Status:', res.statusCode);
    } else {
      // data is already parsed as JSON:
      console.log(data.html_url);
    }
});

Example with http and try/catch

This uses https - just change https to http if you want HTTP connections:

'use strict';
var https = require('https');

var options = {
    host: 'api.github.com',
    path: '/users/rsp',
    headers: {'User-Agent': 'request'}
};

https.get(options, function (res) {
    var json = '';
    res.on('data', function (chunk) {
        json += chunk;
    });
    res.on('end', function () {
        if (res.statusCode === 200) {
            try {
                var data = JSON.parse(json);
                // data is available here:
                console.log(data.html_url);
            } catch (e) {
                console.log('Error parsing JSON!');
            }
        } else {
            console.log('Status:', res.statusCode);
        }
    });
}).on('error', function (err) {
      console.log('Error:', err);
});

Example with http and tryjson

This example is similar to the above but uses the tryjson module. (Disclaimer: I am the author of that module.)

'use strict';
var https = require('https');
var tryjson = require('tryjson');

var options = {
    host: 'api.github.com',
    path: '/users/rsp',
    headers: {'User-Agent': 'request'}
};

https.get(options, function (res) {
    var json = '';

    res.on('data', function (chunk) {
        json += chunk;
    });

    res.on('end', function () {
        if (res.statusCode === 200) {
            var data = tryjson.parse(json);
            console.log(data ? data.html_url : 'Error parsing JSON!');
        } else {
            console.log('Status:', res.statusCode);
        }
    });
}).on('error', function (err) {
      console.log('Error:', err);
});

Summary

The example that uses request is the simplest. But if for some reason you don't want to use it then remember to always check the response code and to parse JSON safely.

Get first element in PHP stdObject

Update PHP 7.4

Curly brace access syntax is deprecated since PHP 7.4

Update 2019

Moving on to the best practices of OOPS, @MrTrick's answer must be marked as correct, although my answer provides a hacked solution its not the best method.

Simply iterate its using {}

Example:

$videos{0}->id

This way your object is not destroyed and you can easily iterate through object.

For PHP 5.6 and below use this

$videos{0}['id']

Both array() and the stdClass objects can be accessed using the current() key() next() prev() reset() end() functions.

So, if your object looks like

object(stdClass)#19 (3) {
  [0]=>
  object(stdClass)#20 (22) {
    ["id"]=>
    string(1) "123"
  etc...

Then you can just do;

$id = reset($obj)->id; //Gets the 'id' attr of the first entry in the object

If you need the key for some reason, you can do;

reset($obj); //Ensure that we're at the first element
$key = key($obj);

Hope that works for you. :-) No errors, even in super-strict mode, on PHP 5.4


2022 Update:
After PHP 7.4, using current(), end(), etc functions on objects is deprecated.

In newer versions of PHP, use the ArrayIterator class:

$objIterator = new ArrayIterator($obj);

$id = $objIterator->current()->id; // Gets the 'id' attr of the first entry in the object

$key = $objIterator->key(); // and gets the key

How to restart counting from 1 after erasing table in MS Access?

I am going to Necro this topic.

Starting around , you can execute Data Definition Queries (DDQ) through Macro's

Data Definition Query


ALTER TABLE <Table> ALTER COLUMN <ID_Field> COUNTER(1,1);

  1. Save the DDQ, with your values
  2. Create a Macro with the appropriate logic either before this or after.
  3. To execute this DDQ:
    • Add an Open Query action
    • Define the name of the DDQ in the Query Name field; View and Data Mode settings are not relevant and can leave the default values

WARNINGS!!!!

  1. This will reset the AutoNumber Counter to 1
  2. Any Referential Integrity will be summarily destroyed

Advice

  • Use this for Staging tables
    • these are tables that are never intended to persist the data they temporarily contain.
    • The data contained is only there until additional cleaning actions have been performed and stored in the appropriate table(s).
    • Once cleaning operations have been performed and the data is no longer needed, these tables are summarily purged of any data contained.
  • Import Tables
    • These are very similar to Staging Tables but tend to only have two columns: ID and RowValue
    • Since these are typically used to import RAW data from a general file format (TXT, RTF, CSV, XML, etc.), the data contained does not persist past the processing lifecycle

What does this thread join code mean?

join() means waiting for a thread to complete. This is a blocker method. Your main thread (the one that does the join()) will wait on the t1.join() line until t1 finishes its work, and then will do the same for t2.join().

Add carriage return to a string

Environment.NewLine should be used as Dan Rigby said but there is one problem with the String.Empty. It will remain always empty no matter if it is read before or after it reads. I had a problem in my project yesterday with that. I removed it and it worked the way it was supposed to. It's better to declare the variable and then call it when it's needed. String.Empty will always keep it empty unless the variable needs to be initialized which only then should you use String.Empty. Thought I would throw this tid-bit out for everyone as I've experienced it.

Can a shell script set environment variables of the calling shell?

Another option is to use "Environment Modules" (http://modules.sourceforge.net/). This unfortunately introduces a third language into the mix. You define the environment with the language of Tcl, but there are a few handy commands for typical modifications (prepend vs. append vs set). You will also need to have environment modules installed. You can then use module load *XXX* to name the environment you want. The module command is basically a fancy alias for the eval mechanism described above by Thomas Kammeyer. The main advantage here is that you can maintain the environment in one language and rely on "Environment Modules" to translate it to sh, ksh, bash, csh, tcsh, zsh, python (?!?!!), etc.

Sort an array in Java

Here is how to use this in your program:

public static void main(String args[])
{
    int [] array = new int[10];

    array[0] = ((int)(Math.random()*100+1));
    array[1] = ((int)(Math.random()*100+1));
    array[2] = ((int)(Math.random()*100+1));
    array[3] = ((int)(Math.random()*100+1));
    array[4] = ((int)(Math.random()*100+1));
    array[5] = ((int)(Math.random()*100+1));
    array[6] = ((int)(Math.random()*100+1));
    array[7] = ((int)(Math.random()*100+1));
    array[8] = ((int)(Math.random()*100+1));
    array[9] = ((int)(Math.random()*100+1));

    Arrays.sort(array); 

    System.out.println(array[0] +" " + array[1] +" " + array[2] +" " + array[3]
    +" " + array[4] +" " + array[5]+" " + array[6]+" " + array[7]+" " 
    + array[8]+" " + array[9] );        

}

Spring: how do I inject an HttpServletRequest into a request-scoped bean?

Request-scoped beans can be autowired with the request object.

private @Autowired HttpServletRequest request;

Adding 1 hour to time variable

You can do like this

    echo date('Y-m-d H:i:s', strtotime('4 minute'));
    echo date('Y-m-d H:i:s', strtotime('6 hour'));
    echo date('Y-m-d H:i:s', strtotime('2 day'));

Abstract class in Java

Class which can have both concrete and non-concrete methods i.e. with and without body.

  1. Methods without implementation must contain 'abstract' keyword.
  2. Abstract class can't be instantiated.

Detect if user is scrolling

window.addEventListener("scroll",function(){
    window.lastScrollTime = new Date().getTime()
});
function is_scrolling() {
    return window.lastScrollTime && new Date().getTime() < window.lastScrollTime + 500
}

Change the 500 to the number of milliseconds after the last scroll event at which you consider the user to be "no longer scrolling".

(addEventListener is better than onScroll because the former can coexist nicely with any other code that uses onScroll.)

How to crop a CvMat in OpenCV?

To create a copy of the crop we want, we can do the following,

// Read img
cv::Mat img = cv::imread("imgFileName");
cv::Mat croppedImg;

// This line picks out the rectangle from the image
// and copies to a new Mat
img(cv::Rect(xMin,yMin,xMax-xMin,yMax-yMin)).copyTo(croppedImg);

// Display diff
cv::imshow( "Original Image",  img );
cv::imshow( "Cropped Image",  croppedImg);
cv::waitKey();

Error: Main method not found in class Calculate, please define the main method as: public static void main(String[] args)

From the docs

In the Java programming language, every application must contain a main method whose signature is:

public static void main(String[] args)

The modifiers public and static can be written in either order (public static or static public), but the convention is to use public static as shown above. You can name the argument anything you want, but most programmers choose "args" or "argv".

As you say:

error: missing method body, or declare abstract public static void main(String[] args); ^ this is what i got after i added it after the class name

You probably haven't declared main with a body (as ';" would suggest in your error).

You need to have main method with a body, which means you need to add { and }:

public static void main(String[] args) {


}

Add it inside your class definition.

Although sometimes error messages are not very clear, most of the time they contain enough information to point to the issue. Worst case, you can search internet for the error message. Also, documentation can be really helpful.

Remove last character from string. Swift language

let str = "abc"
let substr = str.substringToIndex(str.endIndex.predecessor())  // "ab"

Change the bullet color of list

You have to use image

.listStyle {
    list-style: none;
    background: url(bullet.jpg) no-repeat left center;
    padding-left: 40px;
}

Connection refused to MongoDB errno 111

Even though the port is open, MongoDB is currently only listening on the local address 127.0.0.1. To allow remote connections, add your server’s publicly-routable IP address to the mongod.conf file.

Open the MongoDB configuration file in your editor:

sudo nano /etc/mongodb.conf

Add your server’s IP address to the bindIP value:

...
logappend=true

bind_ip = 127.0.0.1,your_server_ip
#port = 27017

...

Note that now everybody who has the username and password can login to your DB and you want to avoid this by restrict the connection only for specific IP's. This can be done using Firewall (read about UFW service at Google). But in short this should be something like this:

sudo ufw allow from YOUR_IP to any port 27017

Limit results in jQuery UI Autocomplete

I've tried all the solutions above, but mine only worked on this way:

success: function (data) {
    response($.map(data.slice (0,10), function(item) {
    return {
    value: item.nome
    };
    }));
},

Android Studio build fails with "Task '' not found in root project 'MyProject'."

Make sure you have the latest values in your gradle files. As of this writing:

  • buildToolsVersion "21.1.2"

  • dependencies { classpath 'com.android.tools.build:gradle:1.1.0' }

How To Change DataType of a DataColumn in a DataTable?

While it is true that you cannot change the type of the column after the DataTable is filled, you can change it after you call FillSchema, but before you call Fill. For example, say the 3rd column is the one you want to convert from double to Int32, you could use:

adapter.FillSchema(table, SchemaType.Source);
table.Columns[2].DataType = typeof (Int32);
adapter.Fill(table);

How to convert number of minutes to hh:mm format in TSQL?

This seems to work for me:

SELECT FORMAT(@mins / 60 * 100 + @mins % 60, '#:0#')

Where does npm install packages?

As the other answers say, the best way is to do

npm list -g

However, if you have a large number of npm packages installed, the output of this command could be very long and a big pain to scroll up (sometimes it's not even possible to scroll that far back).

In this case, pipe the output to the more program, like this

npm list -g | more

How to do a redirect to another route with react-router?

How to do a redirect to another route with react-router?

For example, when a user clicks a link <Link to="/" />Click to route</Link> react-router will look for / and you can use Redirect to and send the user somewhere else like the login route.

From the docs for ReactRouterTraining:

Rendering a <Redirect> will navigate to a new location. The new location will override the current location in the history stack, like server-side redirects (HTTP 3xx) do.

import { Route, Redirect } from 'react-router'

<Route exact path="/" render={() => (
  loggedIn ? (
    <Redirect to="/dashboard"/>
  ) : (
    <PublicHomePage/>
  )
)}/>

to: string, The URL to redirect to.

<Redirect to="/somewhere/else"/>

to: object, A location to redirect to.

<Redirect to={{
  pathname: '/login',
  search: '?utm=your+face',
  state: { referrer: currentLocation }
}}/>

More than one file was found with OS independent path 'META-INF/LICENSE'

I had a similar problem. i was getting the error message -

Error:Execution failed for task ':app:transformResourcesWithMergeJavaResForDebug'.

More than one file was found with OS independent path 'javax/annotation/WillCloseWhenClosed.java'

As stated in some of the answers above, using the below code works

'packagingOptions {
       exclude 'allclasses-frame.html'
    }'

But i was getting this error for 20 different files, so after excluding 20 files, i stopped and tried to find a decent solution. I had also encountered the

'Unable to execute dex: Multiple dex files' error.

I finally managed to solve this.

Firstly (as in my case WillCloseWhenClosed.java was the duplicate file), in android studio you have an option of 'search everywhere'. Write and search for the file there. There i found multiple instances of this file. So i clicked on both instances and saw their location by right clicking on the file and seeing its location when they opened in android studio.

Secondly, I figured out that i had some dependencies in gradle file. I was using the below code

dependencies {
    compile 'com.google.api-client:google-api-client:1.23.0'
}

and also i had their same zip packages in the location :\Users\user\AndroidStudioProjects\git\appname\app\libs\google-http-client-1.23!.

So this was redundant and thats why gradle is finding 2 files. So i deleted my zip packages and it solved the errors for me. Be carefull while doing this. You have to figure out which is the correct file or package to be deleted.

Thirdly, gradle also makes a zip of these bug files in this location (At least for me it made) - C:\Program Files\Android\Android Studio\gradle\m2repository\com\google\code\findbugs\jsr305\1.3.9\jsr305-1.3.9.jar!

so i went and deleted the jsr305-1.3.9.jar file from here also.

If you are still confused, just go the 'search everywhere' in android studio, find instances of your file there and you would have to delete one of them. Take your time and figure out which one.

Registry key for global proxy settings for Internet Explorer 10 on Windows 8

Create a .reg file containing your proxy settings for your users. Create a batch file setting it to setting it to run the .reg file with the extension /s

On a server using a logon script, tell the logon to run the batch file. Jason

CentOS: Copy directory to another directory

As I understand, you want to recursively copy test directory into /home/server/ path...

This can be done as:

-cp -rf /home/server/folder/test/* /home/server/

Hope this helps

Preferred way of loading resources in Java

Well, it partly depends what you want to happen if you're actually in a derived class.

For example, suppose SuperClass is in A.jar and SubClass is in B.jar, and you're executing code in an instance method declared in SuperClass but where this refers to an instance of SubClass. If you use this.getClass().getResource() it will look relative to SubClass, in B.jar. I suspect that's usually not what's required.

Personally I'd probably use Foo.class.getResourceAsStream(name) most often - if you already know the name of the resource you're after, and you're sure of where it is relative to Foo, that's the most robust way of doing it IMO.

Of course there are times when that's not what you want, too: judge each case on its merits. It's just the "I know this resource is bundled with this class" is the most common one I've run into.

XPath: How to select elements based on their value?

The condition below:

//Element[@attribute1="abc" and @attribute2="xyz" and Data]

checks for the existence of the element Data within Element and not for element value Data.

Instead you can use

//Element[@attribute1="abc" and @attribute2="xyz" and text()="Data"]

How can I export a GridView.DataSource to a datatable or dataset?

Assuming your DataSource is of type DataTable, you can just do this:

myGridView.DataSource as DataTable

Using CMake to generate Visual Studio C++ project files

As Alex says, it works very well. The only tricky part is to remember to make any changes in the cmake files, rather than from within Visual Studio. So on all platforms, the workflow is similar to if you'd used plain old makefiles.

But it's fairly easy to work with, and I've had no issues with cmake generating invalid files or anything like that, so I wouldn't worry too much.

HTML Form: Select-Option vs Datalist-Option

To specifically answer a part of your question "Is there any situation in which it would be better to use one or the other?", consider a form with repeating sections. If the repeating section contains many select tags, then the options must be rendered for each select, for every row.

In such a case, I would consider using datalist with input, because the same datalist can be used for any number of inputs. This could potentially save a large amount of rendering time on the server, and would scale much better to any number of rows.

WPF Binding StringFormat Short Date String

If you want add a string with the value use this:

<TextBlock Text="{Binding Date, StringFormat= 'Date : {0:d}'}" />

How to use zIndex in react-native

I believe there are different ways to do this based on what you need exactly, but one way would be to just put both Elements A and B inside Parent A.

    <View style={{ position: 'absolute' }}>    // parent of A
        <View style={{ zIndex: 1 }} />  // element A
        <View style={{ zIndex: 1 }} />  // element A
        <View style={{ zIndex: 0, position: 'absolute' }} />  // element B
    </View>

How to read specific lines from a file (by line number)?

How about this:

>>> with open('a', 'r') as fin: lines = fin.readlines()
>>> for i, line in enumerate(lines):
      if i > 30: break
      if i == 26: dox()
      if i == 30: doy()

@Resource vs @Autowired

In spring pre-3.0 it doesn't matter which one.

In spring 3.0 there's support for the standard (JSR-330) annotation @javax.inject.Inject - use it, with a combination of @Qualifier. Note that spring now also supports the @javax.inject.Qualifier meta-annotation:

@Qualifier
@Retention(RUNTIME)
public @interface YourQualifier {}

So you can have

<bean class="com.pkg.SomeBean">
   <qualifier type="YourQualifier"/>
</bean>

or

@YourQualifier
@Component
public class SomeBean implements Foo { .. }

And then:

@Inject @YourQualifier private Foo foo;

This makes less use of String-names, which can be misspelled and are harder to maintain.


As for the original question: both, without specifying any attributes of the annotation, perform injection by type. The difference is:

  • @Resource allows you to specify a name of the injected bean
  • @Autowired allows you to mark it as non-mandatory.

How to choose an AWS profile when using boto3 to connect to CloudFront

This section of the boto3 documentation is helpful.

Here's what worked for me:

session = boto3.Session(profile_name='dev')
client = session.client('cloudfront')

Getting all names in an enum as a String[]

With java 8:

Arrays.stream(MyEnum.values()).map(Enum::name)
                    .collect(Collectors.toList()).toArray();

Vertical dividers on horizontal UL menu

I do it as Pekka says. Put an inline style on each <li>:

style="border-right: solid 1px #555; border-left: solid 1px #111;"

Take off first and last as appropriate.

How to remove all non-alpha numeric characters from a string in MySQL?

Based on the answer by Ryan Shillington, modified to work with strings longer than 255 characters and preserving spaces from the original string.

FYI there is lower(str) in the end.

I used this to compare strings:

DROP FUNCTION IF EXISTS spacealphanum;
DELIMITER $$
CREATE FUNCTION `spacealphanum`( str TEXT ) RETURNS TEXT CHARSET utf8
BEGIN 
  DECLARE i, len SMALLINT DEFAULT 1; 
  DECLARE ret TEXT DEFAULT ''; 
  DECLARE c CHAR(1); 
  SET len = CHAR_LENGTH( str ); 
  REPEAT 
    BEGIN 
      SET c = MID( str, i, 1 ); 
      IF c REGEXP '[[:alnum:]]' THEN 
        SET ret=CONCAT(ret,c); 
      ELSEIF  c = ' ' THEN
          SET ret=CONCAT(ret," ");
      END IF; 
      SET i = i + 1; 
    END; 
  UNTIL i > len END REPEAT; 
  SET ret = lower(ret);
  RETURN ret; 
  END $$
  DELIMITER ;

How to fix: Handler "PageHandlerFactory-Integrated" has a bad module "ManagedPipelineHandler" in its module list

If you want to deploy an MVC application without installing MVC, you can deploy the MVC DLL's with your application. This gets around installing MVC 3. You can use features in some .Net 4.0 namespaces without installing .Net using a similar approach.

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

I was struggling with this for awhile, so I thought I'd just add my two cents:

1) Create a separate function to check if an fgets input consists entirely of numbers:

int integerCheck(){
char myInput[4];
fgets(myInput, sizeof(myInput), stdin);
    int counter = 0;
    int i;
    for (i=0; myInput[i]!= '\0'; i++){
        if (isalpha(myInput[i]) != 0){
            counter++;
            if(counter > 0){
                printf("Input error: Please try again. \n ");
                return main();
            }
        }

    }
    return atoi(myInput); 
}

The above starts a loop through every unit of an fgets input until the ending NULL value. If it comes across a letter or an operator, it adds "1" to the int "counter" which is initially set to 0. Once the counter becomes greater than 0, the nested if statement instructs the loop to print an error message & then restart the program. When the loops completes, if int 'counter' is still the value of 0, it returns the initially inputted integer to be used in the main function ...

2) the main function would be:

int main(void){
unsigned int numberOne;
unsigned int numberTwo;
numberOne = integerCheck();
numberTwo = integerCheck();
return numberOne*numberTwo;

}

Assuming both integers are inputted correctly, the example provided will yield the result of int "numberOne" multiplied by int "numberTwo". The program will repeat for however long it takes to get two properly inputted integers.

Getting the first and last day of a month, using a given DateTime object

DateTime dCalcDate = DateTime.Now;
dtpFromEffDate.Value = new DateTime(dCalcDate.Year, dCalcDate.Month, 1);
dptToEffDate.Value = new DateTime(dCalcDate.Year, dCalcDate.Month, DateTime.DaysInMonth(dCalcDate.Year, dCalcDate.Month));

Python debugging tips

if you want a nice graphical way to print your call stack in a readable fashion, check out this utility: https://github.com/joerick/pyinstrument

Run from command line:

python -m pyinstrument myscript.py [args...]

Run as a module:

from pyinstrument import Profiler

profiler = Profiler()
profiler.start()

# code you want to profile

profiler.stop()
print(profiler.output_text(unicode=True, color=True))

Run with django:

Just add pyinstrument.middleware.ProfilerMiddleware to MIDDLEWARE_CLASSES, then add ?profile to the end of the request URL to activate the profiler.

PHP string concatenation

One step (IMHO) better

$result .= $personCount . ' people';

How to determine whether a Pandas Column contains a particular value

You can also use pandas.Series.isin although it's a little bit longer than 'a' in s.values:

In [2]: s = pd.Series(list('abc'))

In [3]: s
Out[3]: 
0    a
1    b
2    c
dtype: object

In [3]: s.isin(['a'])
Out[3]: 
0    True
1    False
2    False
dtype: bool

In [4]: s[s.isin(['a'])].empty
Out[4]: False

In [5]: s[s.isin(['z'])].empty
Out[5]: True

But this approach can be more flexible if you need to match multiple values at once for a DataFrame (see DataFrame.isin)

>>> df = DataFrame({'A': [1, 2, 3], 'B': [1, 4, 7]})
>>> df.isin({'A': [1, 3], 'B': [4, 7, 12]})
       A      B
0   True  False  # Note that B didn't match 1 here.
1  False   True
2   True   True

select records from postgres where timestamp is in certain range

Another option to make PostgreSQL use an index for your original query, is to create an index on the expression you are using:

create index arrival_year on reservations ( extract(year from arrival) );

That will open PostgreSQL with the possibility to use an index for

select * 
FROM reservations 
WHERE extract(year from arrival) = 2012;

Note that the expression in the index must be exactly the same expression as used in the where clause to make this work.

How can I have a newline in a string in sh?

What I did based on the other answers was

NEWLINE=$'\n'
my_var="__between eggs and bacon__"
echo "spam${NEWLINE}eggs${my_var}bacon${NEWLINE}knight"

# which outputs:
spam
eggs__between eggs and bacon__bacon
knight

Remove first Item of the array (like popping from stack)

const a = [1, 2, 3]; // -> [2, 3]

// Mutable solutions: update array 'a', 'c' will contain the removed item
const c = a.shift(); // prefered mutable way
const [c] = a.splice(0, 1);

// Immutable solutions: create new array 'b' and leave array 'a' untouched
const b = a.slice(1); // prefered immutable way
const b = a.filter((_, i) => i > 0);
const [c, ...b] = a; // c: the removed item

How to do one-liner if else statement?

Sometimes, I try to use anonymous function to achieve defining and assigning happen at the same line. like below:

a, b = 4, 8

c := func() int {
    if a >b {
      return a
    } 
    return b
  } ()

https://play.golang.org/p/rMjqytMYeQ0

Remove all html tags from php string

$string = <p>Awesome</p><b> Website</b><i> by Narayan</i>. Thanks for visiting enter code here;
$tags = array("p", "i");

echo preg_replace('#<(' . implode( '|', $tags) . ')(?:[^>]+)?>.*?</\1>#s', '', $string);

Try this

How to send FormData objects with Ajax-requests in jQuery?

You can send the FormData object in ajax request using the following code,

$("form#formElement").submit(function(){
    var formData = new FormData($(this)[0]);
});

This is very similar to the accepted answer but an actual answer to the question topic. This will submit the form elements automatically in the FormData and you don't need to manually append the data to FormData variable.

The ajax method looks like this,

$("form#formElement").submit(function(){
    var formData = new FormData($(this)[0]);
    //append some non-form data also
    formData.append('other_data',$("#someInputData").val());
    $.ajax({
        type: "POST",
        url: postDataUrl,
        data: formData,
        processData: false,
        contentType: false,
        dataType: "json",
        success: function(data, textStatus, jqXHR) {
           //process data
        },
        error: function(data, textStatus, jqXHR) {
           //process error msg
        },
});

You can also manually pass the form element inside the FormData object as a parameter like this

var formElem = $("#formId");
var formdata = new FormData(formElem[0]);

Hope it helps. ;)

Is it possible to implement a Python for range loop without an iterator variable?

Instead of an unneeded counter, now you have an unneeded list. Best solution is to use a variable that starts with "_", that tells syntax checkers that you are aware you are not using the variable.

x = range(5)
while x:
  x.pop()
  print "Work!"

Header set Access-Control-Allow-Origin in .htaccess doesn't work

I +1'd Miro's answer for the link to the header-checker site http://www.webconfs.com/http-header-check.php. It pops up an obnoxious ad every time you use it, but it is, nevertheless, very useful for verifying the presence of the Access-Control-Allow-Origin header.

I'm reading a .json file from the javascript on my web page. I found that adding the following to my .htaccess file fixed the problem when viewing my web page in IE 11 (version 11.447.14393.0):

<FilesMatch "\.(json)$">
  <IfModule mod_headers.c>
    Header set Access-Control-Allow-Origin "*"
  </IfModule>
</FilesMatch>

I also added the following to /etc/httpd.conf (Apache's configuration file):

AllowOverride All

The header-checker site verified that the Access-Control-Allow-Origin header is now being sent (thanks, Miro!).

However, Firefox 50.0.2, Opera 41.0.2353.69, and Edge 38.14393.0.0 all fetch the file anyhow, even without the Access-Control-Allow-Origin header. (Note: they might be checking IP addresses, since the two domains I was using are both hosted on the same server, at the same IPv4 address.)

However, Chrome 54.0.2840.99 m (64-bit) ignores the Access-Control-Allow-Origin header and fails anyhow, erroneously reporting:

No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin '{mydomain}' is therefore not allowed access.

I think this has got to be some sort of "first." IE is working correctly; Chrome, Firefox, Opera and Edge are all buggy; and Chrome is the worst. Isn't that the exact opposite of the usual case?

How to test an SQL Update statement before running it?

What about Transactions? They have the ROLLBACK-Feature.

@see https://dev.mysql.com/doc/refman/5.0/en/commit.html

For example:

START TRANSACTION;
SELECT * FROM nicetable WHERE somthing=1;
UPDATE nicetable SET nicefield='VALUE' WHERE somthing=1;
SELECT * FROM nicetable WHERE somthing=1; #check

COMMIT;
# or if you want to reset changes 
ROLLBACK;

SELECT * FROM nicetable WHERE somthing=1; #should be the old value

Answer on question from @rickozoe below:

In general these lines will not be executed as once. In PHP f.e. you would write something like that (perhaps a little bit cleaner, but wanted to answer quick ;-) ):

$MysqlConnection->query('START TRANSACTION;');
$erg = $MysqlConnection->query('UPDATE MyGuests SET lastname='Doe' WHERE id=2;');
if($erg)
    $MysqlConnection->query('COMMIT;');
else
    $MysqlConnection->query('ROLLBACK;');

Another way would be to use MySQL Variables (see https://dev.mysql.com/doc/refman/5.7/en/user-variables.html and https://stackoverflow.com/a/18499823/1416909 ):

# do some stuff that should be conditionally rollbacked later on

SET @v1 := UPDATE MyGuests SET lastname='Doe' WHERE id=2;
IF(v1 < 1) THEN
    ROLLBACK;
ELSE
    COMMIT;
END IF;

But I would suggest to use the language wrappers available in your favorite programming language.

Any way to break if statement in PHP?

I'm late to the party but I wanted to contribute. I'm surprised that nobody suggested exit(). It's good for testing. I use it all the time and works like charm.

$a ='';
$b ='';
if($a == $b){
echo 'Clark Kent is Superman';
exit();
echo 'Clark Kent was never Superman';
}

The code will stop at exit() and everything after will not run.

Result

Clark Kent is Superman

It works with foreach() and while() as well. It works anywhere you place it really.

foreach($arr as $val)
{
  exit();
  echo "test";
}

echo "finish";

Result

nothing gets printed here.

Use it with a forloop()

for ($x = 2; $x < 12; $x++) {
    echo "Gru has $x minions <br>";
    if($x == 4){
    exit();
    }
}

Result

Gru has 2 minions
Gru has 3 minions
Gru has 4 minions

In a normal case scenario

$a ='Make hot chocolate great again!';
echo $a;
exit();
$b = 'I eat chocolate and make Charlie at the Factory pay for it.';

Result

Make hot chocolate great again!

Data binding in React

Define state attributes. Add universal handleChange event handler. Add name param to input tag for mapping.

this.state = { stateAttrName:"" }

handleChange=(event)=>{
    this.setState({[event.target.name]:event.target.value });
  } 

<input className="form-control" name="stateAttrName" value= 
{this.state.stateAttrName} onChange={this.handleChange}/>

Python initializing a list of lists

The problem is that they're all the same exact list in memory. When you use the [x]*n syntax, what you get is a list of n many x objects, but they're all references to the same object. They're not distinct instances, rather, just n references to the same instance.

To make a list of 3 different lists, do this:

x = [[] for i in range(3)]

This gives you 3 separate instances of [], which is what you want

[[]]*n is similar to

l = []
x = []
for i in range(n):
    x.append(l)

While [[] for i in range(3)] is similar to:

x = []
for i in range(n):
    x.append([])   # appending a new list!

In [20]: x = [[]] * 4

In [21]: [id(i) for i in x]
Out[21]: [164363948, 164363948, 164363948, 164363948] # same id()'s for each list,i.e same object


In [22]: x=[[] for i in range(4)]

In [23]: [id(i) for i in x]
Out[23]: [164382060, 164364140, 164363628, 164381292] #different id(), i.e unique objects this time

How to dynamically set bootstrap-datepicker's date value?

That really works.

Simple,

Easy to understand,

Single method to set and update plugin which worked for me.

$(".datepicker").datepicker("update", new Date());

Other ways to update

$('.datepicker').data({date: '2015-01-01'});
$('.datepicker').datepicker('update');

Dont forget to call update manually.

How do I resize a Google Map with JavaScript after it has loaded?

for Google Maps v3, you need to trigger the resize event differently:

google.maps.event.trigger(map, "resize");

See the documentation for the resize event (you'll need to search for the word 'resize'): http://code.google.com/apis/maps/documentation/v3/reference.html#event


Update

This answer has been here a long time, so a little demo might be worthwhile & although it uses jQuery, there's no real need to do so.

_x000D_
_x000D_
$(function() {
  var mapOptions = {
    zoom: 8,
    center: new google.maps.LatLng(-34.397, 150.644)
  };
  var map = new google.maps.Map($("#map-canvas")[0], mapOptions);

  // listen for the window resize event & trigger Google Maps to update too
  $(window).resize(function() {
    // (the 'map' here is the result of the created 'var map = ...' above)
    google.maps.event.trigger(map, "resize");
  });
});
_x000D_
html,
body {
  height: 100%;
}
#map-canvas {
  min-width: 200px;
  width: 50%;
  min-height: 200px;
  height: 80%;
  border: 1px solid blue;
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&dummy=.js"></script>
Google Maps resize demo
<div id="map-canvas"></div>
_x000D_
_x000D_
_x000D_

UPDATE 2018-05-22

With a new renderer release in version 3.32 of Maps JavaScript API the resize event is no longer a part of Map class.

The documentation states

When the map is resized, the map center is fixed

  • The full-screen control now preserves center.

  • There is no longer any need to trigger the resize event manually.

source: https://developers.google.com/maps/documentation/javascript/new-renderer

google.maps.event.trigger(map, "resize"); doesn't have any effect starting from version 3.32

axios post request to send form data

https://www.npmjs.com/package/axios

Its Working

// "content-type": "application/x-www-form-urlencoded", // commit this

import axios from 'axios';

let requestData = {
      username : "[email protected]",
      password: "123456
    };
   
    const url = "Your Url Paste Here";

    let options = {
      method: "POST",
      headers: { 
        'Content-type': 'application/json; charset=UTF-8',

        Authorization: 'Bearer ' + "your token Paste Here",
      },
      data: JSON.stringify(requestData),
      url
    };
    axios(options)
      .then(response => {
        console.log("K_____ res :- ", response);
        console.log("K_____ res status:- ", response.status);
      })
      .catch(error => {
        console.log("K_____ error :- ", error);
      });

fetch request

fetch(url, {
    method: 'POST',
    body: JSON.stringify(requestPayload),           
    headers: {
        'Content-type': 'application/json; charset=UTF-8',
        Authorization: 'Bearer ' + token,
    },
})
    // .then((response) => response.json()) .  // commit out this part if response body is empty
    .then((json) => {
        console.log("response :- ", json);
    }).catch((error)=>{
        console.log("Api call error ", error.message);
        alert(error.message);
});

SQL query question: SELECT ... NOT IN

Given it's SQL 2005, you can also try this It's similar to Oracle's MINUS command (opposite of UNION)

But I would also suggest adding the DATEPART ( hour, insertDate) column for debug

SELECT idCustomer FROM reservations 
EXCEPT
SELECT idCustomer FROM reservations WHERE DATEPART ( hour, insertDate) < 2

When should I use a table variable vs temporary table in sql server?

Microsoft says here

Table variables does not have distribution statistics, they will not trigger recompiles. Therefore, in many cases, the optimizer will build a query plan on the assumption that the table variable has no rows. For this reason, you should be cautious about using a table variable if you expect a larger number of rows (greater than 100). Temp tables may be a better solution in this case.

How to deal with ModalDialog using selenium webdriver?

Nope, Model window needs to be handle by javaScriptExecutor,Because majorly model window made up of window model, This will works once model appeared then control take a place into model and click the expected element.

have to import javascriptexector

like below,

Javascriptexecutor js =(Javascriptexecutor).driver;
js.executescript(**<element to be clicked>**);

How can I run specific migration in laravel

use this command php artisan migrate --path=/database/migrations/my_migration.php it worked for me..

How to determine if .NET Core is installed

One of the dummies ways to determine if .NET Core is installed on Windows is:

  • Press Windows + R
  • Type cmd
  • On the command prompt, type dotnet --version

dotnet --version

If the .NET Core is installed, we should not get any error in the above steps.

Oracle SQL: Use sequence in insert with Select Statement

Assuming that you want to group the data before you generate the key with the sequence, it sounds like you want something like

INSERT INTO HISTORICAL_CAR_STATS (
    HISTORICAL_CAR_STATS_ID, 
    YEAR,
    MONTH, 
    MAKE,
    MODEL,
    REGION,
    AVG_MSRP,
    CNT) 
SELECT MY_SEQ.nextval,
       year,
       month,
       make,
       model,
       region,
       avg_msrp,
       cnt
  FROM (SELECT '2010' year,
               '12' month,
               'ALL' make,
               'ALL' model,
               REGION,
               sum(AVG_MSRP*COUNT)/sum(COUNT) avg_msrp,
               sum(cnt) cnt
          FROM HISTORICAL_CAR_STATS
         WHERE YEAR = '2010' 
           AND MONTH = '12'
           AND MAKE != 'ALL' 
         GROUP BY REGION)

Windows service with timer

First approach with Windows Service is not easy..

A long time ago, I wrote a C# service.

This is the logic of the Service class (tested, works fine):

namespace MyServiceApp
{
    public class MyService : ServiceBase
    {
        private System.Timers.Timer timer;

        protected override void OnStart(string[] args)
        {
            this.timer = new System.Timers.Timer(30000D);  // 30000 milliseconds = 30 seconds
            this.timer.AutoReset = true;
            this.timer.Elapsed += new System.Timers.ElapsedEventHandler(this.timer_Elapsed);
            this.timer.Start();
        }

        protected override void OnStop()
        {
            this.timer.Stop();
            this.timer = null;
        }

        private void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            MyServiceApp.ServiceWork.Main(); // my separate static method for do work
        }

        public MyService()
        {
            this.ServiceName = "MyService";
        }

        // service entry point
        static void Main()
        {
            System.ServiceProcess.ServiceBase.Run(new MyService());
        }
    }
}

I recommend you write your real service work in a separate static method (why not, in a console application...just add reference to it), to simplify debugging and clean service code.

Make sure the interval is enough, and write in log ONLY in OnStart and OnStop overrides.

Hope this helps!

Boolean Field in Oracle

I found this link useful.

Here is the paragraph highlighting some of the pros/cons of each approach.

The most commonly seen design is to imitate the many Boolean-like flags that Oracle's data dictionary views use, selecting 'Y' for true and 'N' for false. However, to interact correctly with host environments, such as JDBC, OCCI, and other programming environments, it's better to select 0 for false and 1 for true so it can work correctly with the getBoolean and setBoolean functions.

Basically they advocate method number 2, for efficiency's sake, using

  • values of 0/1 (because of interoperability with JDBC's getBoolean() etc.) with a check constraint
  • a type of CHAR (because it uses less space than NUMBER).

Their example:

create table tbool (bool char check (bool in (0,1));
insert into tbool values(0);
insert into tbool values(1);`

Preventing scroll bars from being hidden for MacOS trackpad users in WebKit/Blink

Browser scrollbars don't work at all on iPhone/iPad. At work we are using custom JavaScript scrollbars like jScrollPane to provide a consistent cross-browser UI: http://jscrollpane.kelvinluck.com/

It works very well for me - you can make some really beautiful custom scrollbars that fit the design of your site.

JavaScript checking for null vs. undefined and difference between == and ===

undefined

It means the variable is not yet intialized .

Example :

var x;
if(x){ //you can check like this
   //code.
}

equals(==)

It only check value is equals not datatype .

Example :

var x = true;
var y = new Boolean(true);
x == y ; //returns true

Because it checks only value .

Strict Equals(===)

Checks the value and datatype should be same .

Example :

var x = true;
var y = new Boolean(true);
x===y; //returns false.

Because it checks the datatype x is a primitive type and y is a boolean object .

Understanding checked vs unchecked exceptions in Java

To answer the final question (the others seem thoroughly answered above), "Should I bubble up the exact exception or mask it using Exception?"

I am assuming you mean something like this:

public void myMethod() throws Exception {
    // ... something that throws FileNotFoundException ...
}

No, always declare the most precise exception possible, or a list of such. The exceptions you declare your method as capable of throwing are a part of the contract between your method and the caller. Throwing "FileNotFoundException" means that it is possible the file name isn't valid and the file will not be found; the caller will need to handle that intelligently. Throwing Exception means "Hey, sh*t happens. Deal." Which is a very poor API.

In the comments on the first article there are some examples where "throws Exception" is a valid and reasonable declaration, but that's not the case for most "normal" code you will ever write.

Dynamically display a CSV file as an HTML table on a web page

XmlGrid.net has tool to convert csv to html table. Here is the link: http://xmlgrid.net/csvToHtml.html

I used your sample data, and got the following html table:

<table>
<!--Created with XmlGrid Free Online XML Editor (http://xmlgrid.net)-->
<tr>
  <td>Name</td>
  <td> Age</td>
  <td> Sex</td>
</tr>
<tr>
  <td>Cantor, Georg</td>
  <td> 163</td>
  <td> M</td>
</tr>
</table>

ASP.Net 2012 Unobtrusive Validation with jQuery

<add key="ValidationSettings:UnobtrusiveValidationMode" value="WebForms" />

this line was not in my WebConfig so : I simple solved this by downgrading targetting .Net version to 4.0 :)

Find the most frequent number in a NumPy array

You may use

values, counts = np.unique(a, return_counts=True)

ind = np.argmax(counts)
print(values[ind])  # prints the most frequent element

ind = np.argpartition(-counts, kth=10)[:10]
print(values[ind])  # prints the 10 most frequent elements

If some element is as frequent as another one, this code will return only the first element.

How to create named and latest tag in Docker?

Here is my bash script

docker build -t ${IMAGE}:${VERSION} .
docker tag ${IMAGE}:${VERSION} ${IMAGE}:latest

You can then remove untagged images if you rebuilt the same version with

docker rmi $(docker images | grep "^<none>" | awk "{print $3}")

link

or

docker rmi $(docker images | grep "^<none>" | tr -s " " | cut -d' ' -f3 | tr '\n' ' ')

or

Clean up commands:

Docker 1.13 introduces clean-up commands. To remove all unused containers, images, networks and volumes:

docker system prune

or individually:

docker container prune
docker image prune
docker network prune
docker volume prune

Difference between acceptance test and functional test?

The difference is between testing the problem and the solution. Software is a solution to a problem, both can be tested.

The functional test confirms the software performs a function within the boundaries of how you've solved the problem. This is an integral part of developing software, comparable to the testing that is done on mass produced product before it leaves the factory. A functional test verifies that the product actually works as you (the developer) think it does.

Acceptance tests verify the product actually solves the problem it was made to solve. This can best be done by the user (customer), for instance performing his/her tasks that the software assists with. If the software passes this real world test, it's accepted to replace the previous solution. This acceptance test can sometimes only be done properly in production, especially if you have anonymous customers (e.g. a website). Thus a new feature will only be accepted after days or weeks of use.

Functional testing - test the product, verifying that it has the qualities you've designed or build (functions, speed, errors, consistency, etc.)

Acceptance testing - test the product in its context, this requires (simulation of) human interaction, test it has the desired effect on the original problem(s).

PHP - If variable is not empty, echo some html code

if (!empty($web)) {
?>
    <span class="field-label">Website:  </span><a href="http://<?php the_field('website'); ?>" target="_blank"><?php the_field('website'); ?></a> 
<?php
} else { echo "Niente";}

http://us.php.net/manual/en/function.empty.php

Hide div after a few seconds

<script>
      $(function() {
      $(".hide-it").hide(7000);
    });              
</script>

<div id="hide-it">myDiv</div>

The transaction manager has disabled its support for remote/network transactions

Comment from answer: "make sure you use the same open connection for all the database calls inside the transaction. – Magnus"

Our users are stored in a separate db from the data I was working with in the transactions. Opening the db connection to get the user was causing this error for me. Moving the other db connection and user lookup outside of the transaction scope fixed the error.

How to add dividers and spaces between items in RecyclerView?

If you want to add same space for items, the simplest way is to add top+left padding for RecycleView and right+bottom margins to card items.

dimens.xml

<resources>
    <dimen name="divider">1dp</dimen>
</resources>

list_item.xml

<CardView
 android:layout_marginBottom="@dimen/divider"
 android:layout_marginRight="@dimen/divider">
 ...
</CardView>

list.xml

<RecyclerView
 android:paddingLeft="@dimen/divider"
 android:paddingTop="@dimen/divider"
/>

java.lang.OutOfMemoryError: Java heap space

  1. In most of the cases, the code is not optimized. Release those objects which you think shall not be needed further. Avoid creation of objects in your loop each time. Try to use caches. I don't know how your application is doing. But In programming, one rule of normal life applies as well

    Prevention is better than cure. "Don't create unnecessary objects"

Show an image preview before upload

Here I did with jQuery using FileReader API.

Html Markup:

<input id="fileUpload" type="file" multiple />
<div id="image-holder"></div>

jQuery:

Here in jQuery code,first I check for file extension. i.e valid image file to be processed, then will check whether the browser support FileReader API is yes then only processed else display respected message

$("#fileUpload").on('change', function () {

     //Get count of selected files
     var countFiles = $(this)[0].files.length;

     var imgPath = $(this)[0].value;
     var extn = imgPath.substring(imgPath.lastIndexOf('.') + 1).toLowerCase();
     var image_holder = $("#image-holder");
     image_holder.empty();

     if (extn == "gif" || extn == "png" || extn == "jpg" || extn == "jpeg") {
         if (typeof (FileReader) != "undefined") {

             //loop for each file selected for uploaded.
             for (var i = 0; i < countFiles; i++) {

                 var reader = new FileReader();
                 reader.onload = function (e) {
                     $("<img />", {
                         "src": e.target.result,
                             "class": "thumb-image"
                     }).appendTo(image_holder);
                 }

                 image_holder.show();
                 reader.readAsDataURL($(this)[0].files[i]);
             }

         } else {
             alert("This browser does not support FileReader.");
         }
     } else {
         alert("Pls select only images");
     }
 });

Detailed Article: How to Preview Image before upload it, jQuery, HTML5 FileReader() with Live Demo

Conditionally displaying JSF components

Yes, use the rendered attribute.

<h:form rendered="#{some boolean condition}">

You usually tie it to the model rather than letting the model grab the component and manipulate it.

E.g.

<h:form rendered="#{bean.booleanValue}" />
<h:form rendered="#{bean.intValue gt 10}" />
<h:form rendered="#{bean.objectValue eq null}" />
<h:form rendered="#{bean.stringValue ne 'someValue'}" />
<h:form rendered="#{not empty bean.collectionValue}" />
<h:form rendered="#{not bean.booleanValue and bean.intValue ne 0}" />
<h:form rendered="#{bean.enumValue eq 'ONE' or bean.enumValue eq 'TWO'}" />

Note the importance of keyword based EL operators such as gt, ge, le and lt instead of >, >=, <= and < as angle brackets < and > are reserved characters in XML. See also this related Q&A: Error parsing XHTML: The content of elements must consist of well-formed character data or markup.

As to your specific use case, let's assume that the link is passing a parameter like below:

<a href="page.xhtml?form=1">link</a>

You can then show the form as below:

<h:form rendered="#{param.form eq '1'}">

(the #{param} is an implicit EL object referring to a Map representing the request parameters)

See also:

How to create a file with a given size in Linux?

For small files:

dd if=/dev/zero of=upload_test bs=file_size count=1

Where file_size is the size of your test file in bytes.

For big files:

dd if=/dev/zero of=upload_test bs=1M count=size_in_megabytes

java.util.Date to XMLGregorianCalendar

GregorianCalendar c = new GregorianCalendar();
c.setTime(yourDate);
XMLGregorianCalendar date2 = DatatypeFactory.newInstance().newXMLGregorianCalendar(c);

Click a button with XPath containing partial id and title in Selenium IDE

Now that you have provided your HTML sample, we're able to see that your XPath is slightly wrong. While it's valid XPath, it's logically wrong.

You've got:

//*[contains(@id, 'ctl00_btnAircraftMapCell')]//*[contains(@title, 'Select Seat')]

Which translates into:

Get me all the elements that have an ID that contains ctl00_btnAircraftMapCell. Out of these elements, get any child elements that have a title that contains Select Seat.

What you actually want is:

//a[contains(@id, 'ctl00_btnAircraftMapCell') and contains(@title, 'Select Seat')]

Which translates into:

Get me all the anchor elements that have both: an id that contains ctl00_btnAircraftMapCell and a title that contains Select Seat.

No connection string named 'MyEntities' could be found in the application config file

I have faced the same issue. I was missed to put connection string to startup project as I am performing data access operation from other layer. also if you don't have app.config in your startup project then add app.config file and then add a connection string to that config file.

How can I use an http proxy with node.js http.Client?

If you have the Basic http authentication scheme you have to make a base64 string of myuser:mypassword, and then add "Basic" in the beginning. That's the value of Proxy-Authorization header, here an example:

var Http = require('http');

var req = Http.request({
    host: 'myproxy.com.zx',
    port: 8080,
    headers:{"Proxy-Authorization": "Basic bXl1c2VyOm15cGFzc3dvcmQ="},
    method: 'GET',
    path: 'http://www.google.com/'
    }, function (res) {
        res.on('data', function (data) {
        console.log(data.toString());
    });
});

req.end();

In nodejs you could use Buffer to encode

var encodedData = Buffer.from('myuser:mypassword').toString('base64');

console.log(encodedData);

Just as example, in browsers you could encode in base64 using btoa(), useful in ajax requests in a browser without proxy settings performing a request using proxy.

_x000D_
_x000D_
var encodedData = btoa('myuser:mypassword')_x000D_
_x000D_
console.log(encodedData);
_x000D_
_x000D_
_x000D_

How to find wich scheme accepts the proxy server?

If we don't have a custom DNS configured (that would throw something like ERR_NAME_NOT_RESOLVED), when we perform a request, the response (code 407) should inform in the response headers which http authentication scheme the proxy is using.

Print directly from browser without print popup window

this.print(false);

I tried this in Chrome, Firefox and IE. It works only in Firefox and IE, it uses the default printer (with default print settings) and only works when I render a PDF (I use Foxit Reader with Safe Reading Mode disabled). Chrome shows the print dialog, also the other browsers when I render an HTML page.

How do I find out where login scripts live?

The default location for logon scripts is the netlogon share of a domain controller. On the server this is located:

%SystemRoot%'SYSVOL'sysvol''scripts

It can presumably be changes from this default but I've never met anyone that had a reason to.

To get list of domain controllers programatically see this article: http://www.microsoft.com/technet/scriptcenter/resources/qanda/dec04/hey1216.mspx

Creating Unicode character from its number

If you want to get a UTF-16 encoded code unit as a char, you can parse the integer and cast to it as others have suggested.

If you want to support all code points, use Character.toChars(int). This will handle cases where code points cannot fit in a single char value.

Doc says:

Converts the specified character (Unicode code point) to its UTF-16 representation stored in a char array. If the specified code point is a BMP (Basic Multilingual Plane or Plane 0) value, the resulting char array has the same value as codePoint. If the specified code point is a supplementary code point, the resulting char array has the corresponding surrogate pair.

How to create PDFs in an Android app?

PDFJet offers an open-source version of their library that should be able to handle any basic PDF generation task. It's a purely Java-based solution and it is stated to be compatible with Android. There is a commercial version with some additional features that does not appear to be too expensive.

What is the difference between os.path.basename() and os.path.dirname()?

To summarize what was mentioned by Breno above

Say you have a variable with a path to a file

path = '/home/User/Desktop/myfile.py'

os.path.basename(path) returns the string 'myfile.py'

and

os.path.dirname(path) returns the string '/home/User/Desktop' (without a trailing slash '/')

These functions are used when you have to get the filename/directory name given a full path name.

In case the file path is just the file name (e.g. instead of path = '/home/User/Desktop/myfile.py' you just have myfile.py), os.path.dirname(path) returns an empty string.

CSS: How to position two elements on top of each other, without specifying a height?

Of course, the problem is all about getting your height back. But how can you do that if you don't know the height ahead of time? Well, if you know what aspect ratio you want to give the container (and keep it responsive), you can get your height back by adding padding to another child of the container, expressed as a percentage.

You can even add a dummy div to the container and set something like padding-top: 56.25% to give the dummy element a height that is a proportion of the container's width. This will push out the container and give it an aspect ratio, in this case 16:9 (56.25%).

Padding and margin use the percentage of the width, that's really the trick here.

Using getopts to process long and short command line options

getopt and getopts are different beasts, and people seem to have a bit of misunderstanding of what they do. getopts is a built-in command to bash to process command-line options in a loop and assign each found option and value in turn to built-in variables, so you can further process them. getopt, however, is an external utility program, and it doesn't actually process your options for you the way that e.g. bash getopts, the Perl Getopt module or the Python optparse/argparse modules do. All that getopt does is canonicalize the options that are passed in — i.e. convert them to a more standard form, so that it's easier for a shell script to process them. For example, an application of getopt might convert the following:

myscript -ab infile.txt -ooutfile.txt

into this:

myscript -a -b -o outfile.txt infile.txt

You have to do the actual processing yourself. You don't have to use getopt at all if you make various restrictions on the way you can specify options:

  • only put one option per argument;
  • all options go before any positional parameters (i.e. non-option arguments);
  • for options with values (e.g. -o above), the value has to go as a separate argument (after a space).

Why use getopt instead of getopts? The basic reason is that only GNU getopt gives you support for long-named command-line options.1 (GNU getopt is the default on Linux. Mac OS X and FreeBSD come with a basic and not-very-useful getopt, but the GNU version can be installed; see below.)

For example, here's an example of using GNU getopt, from a script of mine called javawrap:

# NOTE: This requires GNU getopt.  On Mac OS X and FreeBSD, you have to install this
# separately; see below.
TEMP=`getopt -o vdm: --long verbose,debug,memory:,debugfile:,minheap:,maxheap: \
             -n 'javawrap' -- "$@"`

if [ $? != 0 ] ; then echo "Terminating..." >&2 ; exit 1 ; fi

# Note the quotes around `$TEMP': they are essential!
eval set -- "$TEMP"

VERBOSE=false
DEBUG=false
MEMORY=
DEBUGFILE=
JAVA_MISC_OPT=
while true; do
  case "$1" in
    -v | --verbose ) VERBOSE=true; shift ;;
    -d | --debug ) DEBUG=true; shift ;;
    -m | --memory ) MEMORY="$2"; shift 2 ;;
    --debugfile ) DEBUGFILE="$2"; shift 2 ;;
    --minheap )
      JAVA_MISC_OPT="$JAVA_MISC_OPT -XX:MinHeapFreeRatio=$2"; shift 2 ;;
    --maxheap )
      JAVA_MISC_OPT="$JAVA_MISC_OPT -XX:MaxHeapFreeRatio=$2"; shift 2 ;;
    -- ) shift; break ;;
    * ) break ;;
  esac
done

This lets you specify options like --verbose -dm4096 --minh=20 --maxhe 40 --debugfi="/Users/John Johnson/debug.txt" or similar. The effect of the call to getopt is to canonicalize the options to --verbose -d -m 4096 --minheap 20 --maxheap 40 --debugfile "/Users/John Johnson/debug.txt" so that you can more easily process them. The quoting around "$1" and "$2" is important as it ensures that arguments with spaces in them get handled properly.

If you delete the first 9 lines (everything up through the eval set line), the code will still work! However, your code will be much pickier in what sorts of options it accepts: In particular, you'll have to specify all options in the "canonical" form described above. With the use of getopt, however, you can group single-letter options, use shorter non-ambiguous forms of long-options, use either the --file foo.txt or --file=foo.txt style, use either the -m 4096 or -m4096 style, mix options and non-options in any order, etc. getopt also outputs an error message if unrecognized or ambiguous options are found.

NOTE: There are actually two totally different versions of getopt, basic getopt and GNU getopt, with different features and different calling conventions.2 Basic getopt is quite broken: Not only does it not handle long options, it also can't even handle embedded spaces inside of arguments or empty arguments, whereas getopts does do this right. The above code will not work in basic getopt. GNU getopt is installed by default on Linux, but on Mac OS X and FreeBSD it needs to be installed separately. On Mac OS X, install MacPorts (http://www.macports.org) and then do sudo port install getopt to install GNU getopt (usually into /opt/local/bin), and make sure that /opt/local/bin is in your shell path ahead of /usr/bin. On FreeBSD, install misc/getopt.

A quick guide to modifying the example code for your own program: Of the first few lines, all is "boilerplate" that should stay the same, except the line that calls getopt. You should change the program name after -n, specify short options after -o, and long options after --long. Put a colon after options that take a value.

Finally, if you see code that has just set instead of eval set, it was written for BSD getopt. You should change it to use the eval set style, which works fine with both versions of getopt, while the plain set doesn't work right with GNU getopt.

1Actually, getopts in ksh93 supports long-named options, but this shell isn't used as often as bash. In zsh, use zparseopts to get this functionality.

2Technically, "GNU getopt" is a misnomer; this version was actually written for Linux rather than the GNU project. However, it follows all the GNU conventions, and the term "GNU getopt" is commonly used (e.g. on FreeBSD).

Why should I use var instead of a type?

In this case it is just coding style.

Use of var is only necessary when dealing with anonymous types.
In other situations it's a matter of taste.

How can I make text appear on next line instead of overflowing?

Just add

white-space: initial;

to the text, a line text will come automatically in the next line.

Is there a performance difference between CTE , Sub-Query, Temporary Table or Table Variable?

Just 2 things I think make it ALWAYS preferable to use a # Temp Table rather then a CTE are:

  1. You can not put a primary key on a CTE so the data being accessed by the CTE will have to traverse each one of the indexes in the CTE's tables rather then just accessing the PK or Index on the temp table.

  2. Because you can not add constraints, indexes and primary keys to a CTE they are more prone to bugs creeping in and bad data.


-onedaywhen yesterday

Here is an example where #table constraints can prevent bad data which is not the case in CTE's

DECLARE @BadData TABLE ( 
                       ThisID int
                     , ThatID int );
INSERT INTO @BadData
       ( ThisID
       , ThatID
       ) 
VALUES
       ( 1, 1 ),
       ( 1, 2 ),
       ( 2, 2 ),
       ( 1, 1 );

IF OBJECT_ID('tempdb..#This') IS NOT NULL
    DROP TABLE #This;
CREATE TABLE #This ( 
             ThisID int NOT NULL
           , ThatID int NOT NULL
                        UNIQUE(ThisID, ThatID) );
INSERT INTO #This
SELECT * FROM @BadData;
WITH This_CTE
     AS (SELECT *
           FROM @BadData)
     SELECT *
       FROM This_CTE;

Limiting the number of characters per line with CSS

You could do this:
(Note! This is CSS3 and the browser support = good!! )

   p {
    text-overflow: ellipsis; /* will make [...] at the end */
    width: 370px; /* change to your preferences */
    white-space: nowrap; /* paragraph to one line */
    overflow:hidden; /* older browsers */
    }

Running Facebook application on localhost

Ok I'm not sure what's up with these answers but I'll let you know what worked for me as advised by a senior dev at my work. I'm working in Ruby on Rails and using Facebook's JavaScript code to get access tokens.

Problem: To do authentication, Facebook is taking the url from your address bar and comparing that with what they have on file. They don't allow you to use localhost:3000 for whatever reason. However, you can use a completely made-up domain name like yoursite.dev by running a local server and pointing yoursite.dev to 127.0.0.1:3000 or wherever your localhost was pointing to.

Step 1: Install or update Nginx

$ brew install nginx (install) or $ brew upgrade nginx (update)

Step 2: Open up your nginx config file

/usr/local/etc/nginx/nginx.conf (usually here)

/opt/boxen/config/nginx/nginx.conf(if you use Boxen)

Step 3 Add this bit of code into your http {} block

Replace proxy_pass with wherever you want to point yoursite.dev to. In my case it was replacing localhost:3000 or the equivalent 127.0.0.1:3000

server {
  listen       yoursite.dev:80;
  server_name  yoursite.dev;
  location / {
    proxy_pass http://127.0.0.1:3000;
  }
}

Step 4: Edit your hosts file, in /etc/hosts on Mac to include

127.0.0.1   yoursite.dev

This file directs domains to localhost. Nginx listens in on localhost and redirects if it matches a rule.

Step 5: Every time you use your dev environment going forward, you use the yoursite.dev in the address bar instead of localhost:3000 so Facebook logs you in correctly.

change PATH permanently on Ubuntu

Add the following line in your .profile file in your home directory (using vi ~/.profile):

PATH=$PATH:/home/me/play
export PATH

Then, for the change to take effect, simply type in your terminal:

$ . ~/.profile

How do I upload a file with metadata using a REST web service?

I realize this is a very old question, but hopefully this will help someone else out as I came upon this post looking for the same thing. I had a similar issue, just that my metadata was a Guid and int. The solution is the same though. You can just make the needed metadata part of the URL.

POST accepting method in your "Controller" class:

public Task<HttpResponseMessage> PostFile(string name, float latitude, float longitude)
{
    //See http://stackoverflow.com/a/10327789/431906 for how to accept a file
    return null;
}

Then in whatever you're registering routes, WebApiConfig.Register(HttpConfiguration config) for me in this case.

config.Routes.MapHttpRoute(
    name: "FooController",
    routeTemplate: "api/{controller}/{name}/{latitude}/{longitude}",
    defaults: new { }
);

Plotting a 3d cube, a sphere and a vector in Matplotlib

My answer is an amalgamation of the above two with extension to drawing sphere of user-defined opacity and some annotation. It finds application in b-vector visualization on a sphere for magnetic resonance image (MRI). Hope you find it useful:

from mpl_toolkits.mplot3d import Axes3D
import matplotlib.pyplot as plt
import numpy as np

fig = plt.figure()
ax = fig.gca(projection='3d')

# draw sphere
u, v = np.mgrid[0:2*np.pi:50j, 0:np.pi:50j]
x = np.cos(u)*np.sin(v)
y = np.sin(u)*np.sin(v)
z = np.cos(v)
# alpha controls opacity
ax.plot_surface(x, y, z, color="g", alpha=0.3)


# a random array of 3D coordinates in [-1,1]
bvecs= np.random.randn(20,3)

# tails of the arrows
tails= np.zeros(len(bvecs))

# heads of the arrows with adjusted arrow head length
ax.quiver(tails,tails,tails,bvecs[:,0], bvecs[:,1], bvecs[:,2],
          length=1.0, normalize=True, color='r', arrow_length_ratio=0.15)

ax.set_xlabel('X-axis')
ax.set_ylabel('Y-axis')
ax.set_zlabel('Z-axis')

ax.set_title('b-vectors on unit sphere')

plt.show()

Overriding !important style

Rather than injecting style, if you inject a class(for eg: 'show') through java script, it will work. But here you need css like below. the added class css rule should be below your original rule.

td.EvenRow a{
  display: none !important;
}

td.EvenRow a.show{
  display: block !important;
}

Django template how to look up a dictionary value with a variable

Since I can't comment, let me do this in the form of an answer:
to build on culebrón's answer or Yuji 'Tomita' Tomita's answer, the dictionary passed into the function is in the form of a string, so perhaps use ast.literal_eval to convert the string to a dictionary first, like in this example.

With this edit, the code should look like this:

# code for custom template tag
@register.filter(name='lookup')
def lookup(value, arg):
    value_dict = ast.literal_eval(value)
    return value_dict.get(arg)

<!--template tag (in the template)-->
{{ mydict|lookup:item.name }}

Send email by using codeigniter library via localhost

I had the same problem and I solved by using the postcast server. You can install it locally and use it.

How do I deserialize a JSON string into an NSDictionary? (For iOS 5+)

NSData *data = [strChangetoJSON dataUsingEncoding:NSUTF8StringEncoding];
NSDictionary *jsonResponse = [NSJSONSerialization JSONObjectWithData:data
                                                             options:kNilOptions
                                                               error:&error];

For example you have a NSString with special characters in NSString strChangetoJSON. Then you can convert that string to JSON response using above code.

How to subtract 30 days from the current date using SQL Server

Try this:

SELECT      GETDATE(), 'Today'
UNION ALL
SELECT      DATEADD(DAY,  10, GETDATE()), '10 Days Later'
UNION ALL
SELECT      DATEADD(DAY, –10, GETDATE()), '10 Days Earlier'
UNION ALL
SELECT      DATEADD(MONTH,  1, GETDATE()), 'Next Month'
UNION ALL
SELECT      DATEADD(MONTH, –1, GETDATE()), 'Previous Month'
UNION ALL
SELECT      DATEADD(YEAR,  1, GETDATE()), 'Next Year'
UNION ALL
SELECT      DATEADD(YEAR, –1, GETDATE()), 'Previous Year'

Result Set:

———————– —————
2011-05-20 21:11:42.390 Today
2011-05-30 21:11:42.390 10 Days Later
2011-05-10 21:11:42.390 10 Days Earlier
2011-06-20 21:11:42.390 Next Month
2011-04-20 21:11:42.390 Previous Month
2012-05-20 21:11:42.390 Next Year
2010-05-20 21:11:42.390 Previous Year

Writing an Excel file in EPPlus

If you have a collection of objects that you load using stored procedure you can also use LoadFromCollection.

using (ExcelPackage package = new ExcelPackage(file))
{
    ExcelWorksheet worksheet = package.Workbook.Worksheets.Add("test");

    worksheet.Cells["A1"].LoadFromCollection(myColl, true, OfficeOpenXml.Table.TableStyles.Medium1);

    package.Save();
}

how to prevent "directory already exists error" in a makefile when using mkdir

On UNIX Just use this:

mkdir -p $(OBJDIR)

The -p option to mkdir prevents the error message if the directory exists.

Completely remove MariaDB or MySQL from CentOS 7 or RHEL 7

To update and answer the question without breaking mail servers. Later versions of CentOS 7 have MariaDB included as the base along with PostFix which relies on MariaDB. Removing using yum will also remove postfix and perl-DBD-MySQL. To get around this and keep postfix in place, first make a copy of /usr/lib64/libmysqlclient.so.18 (which is what postfix depends on) and then use:

rpm -qa | grep mariadb

then remove the mariadb packages using (changing to your versions):

rpm -e --nodeps "mariadb-libs-5.5.56-2.el7.x86_64"
rpm -e --nodeps "mariadb-server-5.5.56-2.el7.x86_64"
rpm -e --nodeps "mariadb-5.5.56-2.el7.x86_64"

Delete left over files and folders (which also removes any databases):

rm -f /var/log/mariadb
rm -f /var/log/mariadb/mariadb.log.rpmsave
rm -rf /var/lib/mysql
rm -rf /usr/lib64/mysql
rm -rf /usr/share/mysql

Put back the copy of /usr/lib64/libmysqlclient.so.18 you made at the start and you can restart postfix.

There is more detail at https://code.trev.id.au/centos-7-remove-mariadb-replace-mysql/ which describes how to replace mariaDB with MySQL

Http Basic Authentication in Java using HttpClient?

This is the code from the accepted answer above, with some changes made regarding the Base64 encoding. The code below compiles.

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

import org.apache.commons.codec.binary.Base64;


public class HttpBasicAuth {

    public static void main(String[] args) {

        try {
            URL url = new URL ("http://ip:port/login");

            Base64 b = new Base64();
            String encoding = b.encodeAsString(new String("test1:test1").getBytes());

            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("POST");
            connection.setDoOutput(true);
            connection.setRequestProperty  ("Authorization", "Basic " + encoding);
            InputStream content = (InputStream)connection.getInputStream();
            BufferedReader in   = 
                new BufferedReader (new InputStreamReader (content));
            String line;
            while ((line = in.readLine()) != null) {
                System.out.println(line);
            }
        } 
        catch(Exception e) {
            e.printStackTrace();
        }
    }
}

How can you use optional parameters in C#?

From this site:

http://www.tek-tips.com/viewthread.cfm?qid=1500861&page=1

C# does allow the use of the [Optional] attribute (from VB, though not functional in C#). So you can have a method like this:

using System.Runtime.InteropServices;
public void Foo(int a, int b, [Optional] int c)
{
  ...
}

In our API wrapper, we detect optional parameters (ParameterInfo p.IsOptional) and set a default value. The goal is to mark parameters as optional without resorting to kludges like having "optional" in the parameter name.

NotificationCenter issue on Swift 3

For all struggling around with the #selector in Swift 3 or Swift 4, here a full code example:

// WE NEED A CLASS THAT SHOULD RECEIVE NOTIFICATIONS
    class MyReceivingClass {

    // ---------------------------------------------
    // INIT -> GOOD PLACE FOR REGISTERING
    // ---------------------------------------------
    init() {
        // WE REGISTER FOR SYSTEM NOTIFICATION (APP WILL RESIGN ACTIVE)

        // Register without parameter
        NotificationCenter.default.addObserver(self, selector: #selector(MyReceivingClass.handleNotification), name: .UIApplicationWillResignActive, object: nil)

        // Register WITH parameter
        NotificationCenter.default.addObserver(self, selector: #selector(MyReceivingClass.handle(withNotification:)), name: .UIApplicationWillResignActive, object: nil)
    }

    // ---------------------------------------------
    // DE-INIT -> LAST OPTION FOR RE-REGISTERING
    // ---------------------------------------------
    deinit {
        NotificationCenter.default.removeObserver(self)
    }

    // either "MyReceivingClass" must be a subclass of NSObject OR selector-methods MUST BE signed with '@objc'

    // ---------------------------------------------
    // HANDLE NOTIFICATION WITHOUT PARAMETER
    // ---------------------------------------------
    @objc func handleNotification() {
        print("RECEIVED ANY NOTIFICATION")
    }

    // ---------------------------------------------
    // HANDLE NOTIFICATION WITH PARAMETER
    // ---------------------------------------------
    @objc func handle(withNotification notification : NSNotification) {
        print("RECEIVED SPECIFIC NOTIFICATION: \(notification)")
    }
}

In this example we try to get POSTs from AppDelegate (so in AppDelegate implement this):

// ---------------------------------------------
// WHEN APP IS GOING TO BE INACTIVE
// ---------------------------------------------
func applicationWillResignActive(_ application: UIApplication) {

    print("POSTING")

    // Define identifiyer
    let notificationName = Notification.Name.UIApplicationWillResignActive

    // Post notification
    NotificationCenter.default.post(name: notificationName, object: nil)
}

How do I rotate the Android emulator display?

Windows: left Ctrl + F12

Mac: Fn + Ctrl + F12

What causing this "Invalid length for a Base-64 char array"

I've seen this error caused by the combination of good sized viewstate and over aggressive content-filtering devices/firewalls (especially when dealing with K-12 Educational institutions).

We worked around it by storing Viewstate in SQL Server. Before going that route, I would recommend trying to limit your use of viewstate by not storing anything large in it and turning it off for all controls which do not need it.

References for storing ViewState in SQL Server:
MSDN - Overview of PageStatePersister
ASP Alliance - Simple method to store viewstate in SQL Server
Code Project - ViewState Provider Model

Detect page change on DataTable

This works form me to scroll to when I click next

$('#myTable').on('draw.dt', function() {
    document.body.scrollTop = 0;
    document.documentElement.scrollTop = 0;
});

New self vs. new static

In addition to others' answers :

static:: will be computed using runtime information.

That means you can't use static:: in a class property because properties values :

Must be able to be evaluated at compile time and must not depend on run-time information.

class Foo {
    public $name = static::class;

}

$Foo = new Foo;
echo $Foo->name; // Fatal error

Using self::

class Foo {
    public $name = self::class;

}
$Foo = new Foo;
echo $Foo->name; // Foo

Please note that the Fatal error comment in the code i made doesn't indicate where the error happened, the error happened earlier before the object was instantiated as @Grapestain mentioned in the comments

Unix - copy contents of one directory to another

To make an exact copy, permissions, ownership, and all use "-a" with "cp". "-r" will copy the contents of the files but not necessarily keep other things the same.

cp -av Source/* Dest/

(make sure Dest/ exists first)

If you want to repeatedly update from one to the other or make sure you also copy all dotfiles, rsync is a great help:

rsync -av --delete Source/ Dest/

This is also "recoverable" in that you can restart it if you abort it while copying. I like "-v" because it lets you watch what is going on but you can omit it.

Why extend the Android Application class?

Not an answer but an observation: keep in mind that the data in the extended application object should not be tied to an instance of an activity, as it is possible that you have two instances of the same activity running at the same time (one in the foreground and one not being visible).

For example, you start your activity normally through the launcher, then "minimize" it. You then start another app (ie Tasker) which starts another instance of your activitiy, for example in order to create a shortcut, because your app supports android.intent.action.CREATE_SHORTCUT. If the shortcut is then created and this shortcut-creating invocation of the activity modified the data the application object, then the activity running in the background will start to use this modified application object once it is brought back to the foreground.

TypeError: Router.use() requires middleware function but got a Object

I had this error and solution help which was posted by Anirudh. I built a template for express routing and forgot about this nuance - glad it was an easy fix.

I wanted to give a little clarification to his answer on where to put this code by explaining my file structure.

My typical file structure is as follows:

/lib

/routes

---index.js (controls the main navigation)

/page-one



/page-two



     ---index.js

(each file [in my case the index.js within page-two, although page-one would have an index.js too]- for each page - that uses app.METHOD or router.METHOD needs to have module.exports = router; at the end)

If someone wants I will post a link to github template that implements express routing using best practices. let me know

Thanks Anirudh!!! for the great answer.

Reactjs convert html string to jsx

npm i html-react-parser;

import Parser from 'html-react-parser';

<td>{Parser(this.state.archyves)}</td>

How do I stretch an image to fit the whole background (100% height x 100% width) in Flutter?

Inside your Stack, you should wrap your background widget in a Positioned.fill.

return new Stack(
  children: <Widget>[
    new Positioned.fill(
      child: background,
    ),
    foreground,
  ],
);

Display filename before matching line

Try this little trick to coax grep into thinking it is dealing with multiple files, so that it displays the filename:

grep 'pattern' file /dev/null

To also get the line number:

grep -n 'pattern' file /dev/null

Difference between variable declaration syntaxes in Javascript (including global variables)?

In global scope there is no semantic difference.

But you really should avoid a=0 since your setting a value to an undeclared variable.

Also use closures to avoid editing global scope at all

(function() {
   // do stuff locally

   // Hoist something to global scope
   window.someGlobal = someLocal
}());

Always use closures and always hoist to global scope when its absolutely neccesary. You should be using asynchronous event handling for most of your communication anyway.

As @AvianMoncellor mentioned there is an IE bug with var a = foo only declaring a global for file scope. This is an issue with IE's notorious broken interpreter. This bug does sound familiar so it's probably true.

So stick to window.globalName = someLocalpointer

How do I POST JSON data with cURL?

Using CURL Windows, try this:

curl -X POST -H "Content-Type:application/json" -d "{\"firstName\": \"blablabla\",\"lastName\": \"dummy\",\"id\": \"123456\"}" http-host/_ah/api/employeeendpoint/v1/employee

href overrides ng-click in Angular.js

Just one more hint. If you need real URL (to support browser accessibility) you can do the following:

template:

<a ng-href="{{link}}" ng-click="$event.preventDefault(); linkClicked(link)">{{link}}</a>

directive:

$scope.linkClicked = function(link){
    // your code here
    $location.path(link);
};

In this way your code in linkClicked() will have chance to execute before navigating to the link

How to get the size of a file in MB (Megabytes)?

file.length() will return you the length in bytes, then you divide that by 1048576, and now you've got megabytes!

How to set the range of y-axis for a seaborn boxplot?

It is standard matplotlib.pyplot:

...
import matplotlib.pyplot as plt
plt.ylim(10, 40)

Or simpler, as mwaskom comments below:

ax.set(ylim=(10, 40))

enter image description here

How to make a round button?

Used the shape as oval. This makes the button oval

<item>
    <shape android:shape="oval" >
        <stroke
            android:height="1.0dip"
            android:width="1.0dip"
            android:color="#ffee82ee" />

        <solid android:color="#ffee82ee" />

        <corners
            android:bottomLeftRadius="12.0dip"
            android:bottomRightRadius="12.0dip"
            android:radius="12.0dip"
            android:topLeftRadius="12.0dip"
            android:topRightRadius="12.0dip" />
    </shape>
</item>