SyntaxFix

Programs & Examples On #Actinic

Actinic is a software development company who manufacture components for E-Commerce web applications such as shopping carts.

What is the difference between GitHub and gist?

My personal understanding or to say my personal usage of Gist and Github is:

  • Github

A big project work. If you wanna build website, develop mobile or web application or do your assignment with your teammates of course use github.

  • Gist

more like a memo. for example you can write the implementation of a small feature and share it to your blog or write down what you think about the project and share it with your teammates. Just like what the above answers said, gist is used for more like code snippet thing. So normally if you work on a project you use github.

How to get current screen width in CSS?

Use the CSS3 Viewport-percentage feature.

Viewport-Percentage Explanation

Assuming you want the body width size to be a ratio of the browser's view port. I added a border so you can see the body resize as you change your browser width or height. I used a ratio of 90% of the view-port size.

_x000D_
_x000D_ 
<!DOCTYPE html>_x000D_
<html lang="en">_x000D_
<head>_x000D_
    <title>Styles</title>_x000D_
_x000D_
    <style>_x000D_
        @media screen and (min-width: 480px) {_x000D_
            body {_x000D_
                background-color: skyblue;_x000D_
                width: 90vw;_x000D_
                height: 90vh;_x000D_
                border: groove black;_x000D_
            }_x000D_
_x000D_
            div#main {_x000D_
                font-size: 3vw;_x000D_
            }_x000D_
        }_x000D_
    </style>_x000D_
_x000D_
</head>_x000D_
<body>_x000D_
    <div id="main">_x000D_
        Viewport-Percentage Test_x000D_
    </div>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Calculate age based on date of birth

Got this script from net (thanks to coffeecupweb)

<?php
/**
 * Simple PHP age Calculator
 * 
 * Calculate and returns age based on the date provided by the user.
 * @param   date of birth('Format:yyyy-mm-dd').
 * @return  age based on date of birth
 */
function ageCalculator($dob){
    if(!empty($dob)){
        $birthdate = new DateTime($dob);
        $today   = new DateTime('today');
        $age = $birthdate->diff($today)->y;
        return $age;
    }else{
        return 0;
    }
}
$dob = '1992-03-18';
echo ageCalculator($dob);
?>

CMD what does /im (taskkill)?

If you type the executable name and a /? switch at the command line, there is typically help information available. Doing so with taskkill /? provides the following, for instance:

TASKKILL [/S system [/U username [/P [password]]]]
         { [/FI filter] [/PID processid | /IM imagename] } [/T] [/F]

Description:
    This tool is used to terminate tasks by process id (PID) or image name.

Parameter List:
    /S    system           Specifies the remote system to connect to.

    /U    [domain\]user    Specifies the user context under which the
                           command should execute.

    /P    [password]       Specifies the password for the given user
                           context. Prompts for input if omitted.

    /FI   filter           Applies a filter to select a set of tasks.
                           Allows "*" to be used. ex. imagename eq acme*

    /PID  processid        Specifies the PID of the process to be terminated.
                           Use TaskList to get the PID.

    /IM   imagename        Specifies the image name of the process
                           to be terminated. Wildcard '*' can be used
                           to specify all tasks or image names.

    /T                     Terminates the specified process and any
                           child processes which were started by it.

    /F                     Specifies to forcefully terminate the process(es).

    /?                     Displays this help message.

Filters:
    Filter Name   Valid Operators           Valid Value(s)
    -----------   ---------------           -------------------------
    STATUS        eq, ne                    RUNNING |
                                            NOT RESPONDING | UNKNOWN
    IMAGENAME     eq, ne                    Image name
    PID           eq, ne, gt, lt, ge, le    PID value
    SESSION       eq, ne, gt, lt, ge, le    Session number.
    CPUTIME       eq, ne, gt, lt, ge, le    CPU time in the format
                                            of hh:mm:ss.
                                            hh - hours,
                                            mm - minutes, ss - seconds
    MEMUSAGE      eq, ne, gt, lt, ge, le    Memory usage in KB
    USERNAME      eq, ne                    User name in [domain\]user
                                            format
    MODULES       eq, ne                    DLL name
    SERVICES      eq, ne                    Service name
    WINDOWTITLE   eq, ne                    Window title

    NOTE
    ----
    1) Wildcard '*' for /IM switch is accepted only when a filter is applied.
    2) Termination of remote processes will always be done forcefully (/F).
    3) "WINDOWTITLE" and "STATUS" filters are not considered when a remote
       machine is specified.

Examples:
    TASKKILL /IM notepad.exe
    TASKKILL /PID 1230 /PID 1241 /PID 1253 /T
    TASKKILL /F /IM cmd.exe /T 
    TASKKILL /F /FI "PID ge 1000" /FI "WINDOWTITLE ne untitle*"
    TASKKILL /F /FI "USERNAME eq NT AUTHORITY\SYSTEM" /IM notepad.exe
    TASKKILL /S system /U domain\username /FI "USERNAME ne NT*" /IM *
    TASKKILL /S system /U username /P password /FI "IMAGENAME eq note*"

You can also find this information, as well as documentation for most of the other command-line utilities, in the Microsoft TechNet Command-Line Reference

Visualizing branch topology in Git

I found this blog post which shows a concise way:

git log --oneline --abbrev-commit --all --graph --decorate --color

I usually create an alias for the above command:

alias gl='git log --oneline --abbrev-commit --all --graph --decorate --color'

and simple just use gl.

You can also add the alias to the git config . Open ~/.gitconfig and add the following line to the [alias]

[alias]
        lg = log --oneline --abbrev-commit --all --graph --decorate --color

and use it like this: git lg

How do I install g++ for Fedora?

instead of g++ you have to write gcc-c++

sudo dnf install gcc-c++

Top 5 time-consuming SQL queries in Oracle

There are a number of possible ways to do this, but have a google for tkprof

There's no GUI... it's entirely command line and possibly a touch intimidating for Oracle beginners; but it's very powerful.

This link looks like a good start:

http://www.oracleutilities.com/OSUtil/tkprof.html

How to convert JSON string into List of Java object?

use below simple code, no need to use any library

String list = "your_json_string";
Gson gson = new Gson();                         
Type listType = new TypeToken<ArrayList<YourClassObject>>() {}.getType();
ArrayList<YourClassObject> users = new Gson().fromJson(list , listType);

How to find sitemap.xml path on websites?

Use Google Search Operators to find it for you

search google with the below code..

inurl:domain.com filetype:xml click on this to view sitemap search example

change domain.com to the domain you want to find the sitemap. this should list all the xml files listed for the given domain.. including all sitemaps :)

How to check if input date is equal to today's date?

The following solution compares the timestamp integer divided by the values of hours, minutes, seconds, millis.

var reducedToDay = function(date){return ~~(date.getTime()/(1000*60*60*24));};
return reducedToDay(date1) == reducedToDay(date2)

The tilde truncs the division result (see this article about integer division)

Bootstrap 3: Text overlay on image

try the following example. Image overlay with text on image. demo 

<div class="thumbnail">
  <img src="https://s3.amazonaws.com/discount_now_staging/uploads/ed964a11-e089-4c61-b927-9623a3fe9dcb/direct_uploader_2F50cc1daf-465f-48f0-8417-b04ac68a999d_2FN_19_jewelry.jpg" alt="..."   />
  <div class="caption post-content">  
  </div> 
  <div class="details">
    <h3>Robots!</h3>
    <p>Lorem ipsum dolor sit amet</p>   
  </div>  
</div>

css

.post-content {
    background: rgba(0, 0, 0, 0.7) none repeat scroll 0 0;
    opacity: 0.5;
    top:0;
    left:0;
    min-width: 500px;
    min-height: 500px; 
    position: absolute;
    color: #ffffff; 
}

.thumbnail{
    position:relative;

}
.details {
    position: absolute; 
    z-index: 2; 
    top: 0;
    color: #ffffff; 
}

Deserialize JSON into C# dynamic object?

I use http://json2csharp.com/ to get a class representing the JSON object.

Input:

{
   "name":"John",
   "age":31,
   "city":"New York",
   "Childs":[
      {
         "name":"Jim",
         "age":11
      },
      {
         "name":"Tim",
         "age":9
      }
   ]
}

Output:

public class Child
{
    public string name { get; set; }
    public int age { get; set; }
}

public class Person
{
    public string name { get; set; }
    public int age { get; set; }
    public string city { get; set; }
    public List<Child> Childs { get; set; }
}

After that I use Newtonsoft.Json to fill the class:

using Newtonsoft.Json;

namespace GitRepositoryCreator.Common
{
    class JObjects
    {
        public static string Get(object p_object)
        {
            return JsonConvert.SerializeObject(p_object);
        }
        internal static T Get<T>(string p_object)
        {
            return JsonConvert.DeserializeObject<T>(p_object);
        }
    }
}

You can call it like this:

Person jsonClass = JObjects.Get<Person>(stringJson);

string stringJson = JObjects.Get(jsonClass);

PS:

If your JSON variable name is not a valid C# name (name starts with $) you can fix that like this:

public class Exception
{
   [JsonProperty(PropertyName = "$id")]
   public string id { get; set; }
   public object innerException { get; set; }
   public string message { get; set; }
   public string typeName { get; set; }
   public string typeKey { get; set; }
   public int errorCode { get; set; }
   public int eventId { get; set; }
}

how to run mysql in ubuntu through terminal

You have to give a valid username. For example, to run query with user root you have to type the following command and then enter password when prompted:

mysql -u root -p

Once you are connected, prompt will be something like:

mysql>

Here you can write your query, after database selection, for example:

mysql> USE your_database;
mysql> SELECT * FROM your_table;

CSS Selector that applies to elements with two classes

Chain both class selectors (without a space in between):

.foo.bar {
    /* Styles for element(s) with foo AND bar classes */
}

If you still have to deal with ancient browsers like IE6, be aware that it doesn't read chained class selectors correctly: it'll only read the last class selector (.bar in this case) instead, regardless of what other classes you list.

To illustrate how other browsers and IE6 interpret this, consider this CSS:

* {
    color: black;
}

.foo.bar {
    color: red;
}

Output on supported browsers is:

<div class="foo">Hello Foo</div>       <!-- Not selected, black text [1] -->
<div class="foo bar">Hello World</div> <!-- Selected, red text [2] -->
<div class="bar">Hello Bar</div>       <!-- Not selected, black text [3] -->

Output on IE6 is:

<div class="foo">Hello Foo</div>       <!-- Not selected, black text [1] -->
<div class="foo bar">Hello World</div> <!-- Selected, red text [2] -->
<div class="bar">Hello Bar</div>       <!-- Selected, red text [2] -->

Footnotes:

  • Supported browsers:
    1. Not selected as this element only has class foo.
    2. Selected as this element has both classes foo and bar.
    3. Not selected as this element only has class bar.

  • IE6:
    1. Not selected as this element doesn't have class bar.
    2. Selected as this element has class bar, regardless of any other classes listed.

Get encoding of a file in Windows

The (Linux) command-line tool 'file' is available on Windows via GnuWin32:

http://gnuwin32.sourceforge.net/packages/file.htm

If you have git installed, it's located in C:\Program Files\git\usr\bin.

Example:

    C:\Users\SH\Downloads\SquareRoot>file *
    _UpgradeReport_Files;         directory
    Debug;                        directory
    duration.h;                   ASCII C++ program text, with CRLF line terminators
    ipch;                         directory
    main.cpp;                     ASCII C program text, with CRLF line terminators
    Precision.txt;                ASCII text, with CRLF line terminators
    Release;                      directory
    Speed.txt;                    ASCII text, with CRLF line terminators
    SquareRoot.sdf;               data
    SquareRoot.sln;               UTF-8 Unicode (with BOM) text, with CRLF line terminators
    SquareRoot.sln.docstates.suo; PCX ver. 2.5 image data
    SquareRoot.suo;               CDF V2 Document, corrupt: Cannot read summary info
    SquareRoot.vcproj;            XML  document text
    SquareRoot.vcxproj;           XML document text
    SquareRoot.vcxproj.filters;   XML document text
    SquareRoot.vcxproj.user;      XML document text
    squarerootmethods.h;          ASCII C program text, with CRLF line terminators
    UpgradeLog.XML;               XML  document text

    C:\Users\SH\Downloads\SquareRoot>file --mime-encoding *
    _UpgradeReport_Files;         binary
    Debug;                        binary
    duration.h;                   us-ascii
    ipch;                         binary
    main.cpp;                     us-ascii
    Precision.txt;                us-ascii
    Release;                      binary
    Speed.txt;                    us-ascii
    SquareRoot.sdf;               binary
    SquareRoot.sln;               utf-8
    SquareRoot.sln.docstates.suo; binary
    SquareRoot.suo;               CDF V2 Document, corrupt: Cannot read summary infobinary
    SquareRoot.vcproj;            us-ascii
    SquareRoot.vcxproj;           utf-8
    SquareRoot.vcxproj.filters;   utf-8
    SquareRoot.vcxproj.user;      utf-8
    squarerootmethods.h;          us-ascii
    UpgradeLog.XML;               us-ascii

How do I use the JAVA_OPTS environment variable?

JAVA_OPTS is not restricted to Tomcat’s Java process, but passed to all JVM processes running on the same machine.

Use CATALINA_OPTS if you specifically want to pass JVM arguments to Tomcat's servlet engine.

How to select <td> of the <table> with javascript?

There are also the rows and cells members;

var t = document.getElementById("tbl");
for (var r = 0; r < t.rows.length; r++) {
    for (var c = 0; c < t.rows[r].cells.length; c++) {
        alert(t.rows[r].cells[c].innerHTML)
    }
}

Multiline TextView in Android?

I hope these answers are little bit old, just change the input type in resource layout file will solve your problem. For example:

<EditText
        android:id="@+id/notesInput"
        android:hint="Notes"
        android:inputType="textMultiLine"
/>

Counting DISTINCT over multiple columns

This code uses distinct on 2 parameters and provides count of number of rows specific to those distinct values row count. It worked for me in MySQL like a charm.

select DISTINCT DocumentId as i,  DocumentSessionId as s , count(*) 
from DocumentOutputItems   
group by i ,s;

Entity Framework - Generating Classes

1) First you need to generate EDMX model using your database. To do that you should add new item to your project:

  • Select ADO.NET Entity Data Model from the Templates list.
  • On the Choose Model Contents page, select the Generate from Database option and click Next.
  • Choose your database.
  • On the Choose Your Database Objects page, check the Tables. Choose Views or Stored Procedures if you need.

So now you have Model1.edmx file in your project.

2) To generate classes using your model:

  • Open your EDMX model designer.
  • On the design surface Right Click –> Add Code Generation Item…
  • Select Online templates.
  • Select EF 4.x DbContext Generator for C#.
  • Click ‘Add’.

Notice that two items are added to your project:

  • Model1.tt (This template generates very simple POCO classes for each entity in your model)
  • Model1.Context.tt (This template generates a derived DbContext to use for querying and persisting data)

3) Read/Write Data example:

 var dbContext = new YourModelClass(); //class derived from DbContext
 var contacts = from c in dbContext.Contacts select c; //read data
 contacts.FirstOrDefault().FirstName = "Alex"; //edit data
 dbContext.SaveChanges(); //save data to DB

Don't forget that you need 4.x version of EntityFramework. You can download EF 4.1 here: Entity Framework 4.1.

How to get milliseconds from LocalDateTime in Java 8

You can use java.sql.Timestamp also to get milliseconds.

LocalDateTime now = LocalDateTime.now();
long milliSeconds = Timestamp.valueOf(now).getTime();
System.out.println("MilliSeconds: "+milliSeconds);

How can I convert a PFX certificate file for use with Apache on a linux server?

With OpenSSL you can convert pfx to Apache compatible format with next commands:

openssl pkcs12 -in domain.pfx -clcerts -nokeys -out domain.cer
openssl pkcs12 -in domain.pfx -nocerts -nodes  -out domain.key

First command extracts public key to domain.cer.
Second command extracts private key to domain.key.

Update your Apache configuration file with: 

<VirtualHost 192.168.0.1:443>
 ...
 SSLEngine on
 SSLCertificateFile /path/to/domain.cer
 SSLCertificateKeyFile /path/to/domain.key
 ...
</VirtualHost>

Get URL query string parameters

If you want the whole query string:

$_SERVER["QUERY_STRING"]

How to insert a large block of HTML in JavaScript?

If you are using on the same domain then you can create a seperate HTML file and then import this using the code from this answer by @Stano :

https://stackoverflow.com/a/34579496/2468603

System.Net.WebException HTTP status code

this works only if WebResponse is a HttpWebResponse.

try
{
    ...
}
catch (System.Net.WebException exc)
{
    var webResponse = exc.Response as System.Net.HttpWebResponse;
    if (webResponse != null && 
        webResponse.StatusCode == System.Net.HttpStatusCode.Unauthorized)
    {
        MessageBox.Show("401");
    }
    else
        throw;
}

Converting Swagger specification JSON to HTML documentation

I spent a lot of time and tried a lot of different solutions - in the end I did it this way :

<html>
    <head>    
        <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/swagger-ui.css">
        <script src="//unpkg.com/swagger-ui-dist@3/swagger-ui-bundle.js"></script>
        <script>

            function render() {
                var ui = SwaggerUIBundle({
                    url:  `path/to/my/swagger.yaml`,
                    dom_id: '#swagger-ui',
                    presets: [
                        SwaggerUIBundle.presets.apis,
                        SwaggerUIBundle.SwaggerUIStandalonePreset
                    ]
                });
            }

        </script>
    </head>

    <body onload="render()">
        <div id="swagger-ui"></div>
    </body>
</html>

You just need to have path/to/my/swagger.yaml served from the same location.
(or use CORS headers)

Removing duplicate rows from table in Oracle

Solution 4)

 delete from emp where rowid in
            (
             select rid from
                (
                  select rowid rid,
                  dense_rank() over(partition by empno order by rowid
                ) rn
             from emp
            )
 where rn > 1
);

How can I get the root domain URI in ASP.NET?

To get the entire request URL string:

HttpContext.Current.Request.Url

To get the www.foo.com portion of the request:

HttpContext.Current.Request.Url.Host

Note that you are, to some degree, at the mercy of factors outside your ASP.NET application. If IIS is configured to accept multiple or any host header for your application, then any of those domains which resolved to your application via DNS may show up as the Request Url, depending on which one the user entered.

Get the index of a certain value in an array in PHP

 
$find="Topsite";
$list=array("Tope","Ajayi","Topsite","Infotech");
$list_count=count($list);
sort($list);
for($i=0;$i<$list_count;$i++)
{
    if($list[$i]==$find){
         $position=$i;
    }

}
echo $position;

VBA equivalent to Excel's mod function

My way to replicate Excel's MOD(a,b) in VBA is to use XLMod(a,b) in VBA where you include the function:

Function XLMod(a, b)
    ' This replicates the Excel MOD function
    XLMod = a - b * Int(a / b)
End Function

in your VBA Module

How can I maintain fragment state when added to the back stack?

If you return to a fragment from the back stack it does not re-create the fragment but re-uses the same instance and starts with onCreateView() in the fragment lifecycle, see Fragment lifecycle.

So if you want to store state you should use instance variables and not rely on onSaveInstanceState().

Moving x-axis to the top of a plot in matplotlib

tick_params is very useful for setting tick properties. Labels can be moved to the top with:

    ax.tick_params(labelbottom=False,labeltop=True)

Is it possible to delete an object's property in PHP?

This also works if you are looping over an object.

unset($object->$key);

No need to use brackets.

What is the command to exit a Console application in C#?

You can use Environment.Exit(0) and Application.Exit.

Environment.Exit(): terminates this process and gives the underlying operating system the specified exit code.

Calling a PHP function from an HTML form in the same file

This cannot be done in the fashion you are talking about. PHP is server-side while the form exists on the client-side. You will need to look into using JavaScript and/or Ajax if you don't want to refresh the page.

test.php

<form action="javascript:void(0);" method="post">
    <input type="text" name="user" placeholder="enter a text" />
    <input type="submit" value="submit" />
</form>

<script type="text/javascript">
    $("form").submit(function(){
        var str = $(this).serialize();
        $.ajax('getResult.php', str, function(result){
            alert(result); // The result variable will contain any text echoed by getResult.php
        }
        return(false);
    });
</script>

It will call getResult.php and pass the serialized form to it so the PHP can read those values. Anything getResult.php echos will be returned to the JavaScript function in the result variable back on test.php and (in this case) shown in an alert box.

getResult.php

<?php
    echo "The name you typed is: " . $_REQUEST['user'];
?>

NOTE

This example uses jQuery, a third-party JavaScript wrapper. I suggest you first develop a better understanding of how these web technologies work together before complicating things for yourself further.

How To Change DataType of a DataColumn in a DataTable?

I've taken a bit of a different approach. I needed to parse a datetime from an excel import that was in the OA date format. This methodology is simple enough to build from... in essence,

  1. Add column of type you want
  2. Rip through the rows converting the value

  3. Delete the original column and rename to the new to match the old

    private void ChangeColumnType(System.Data.DataTable dt, string p, Type type){
        dt.Columns.Add(p + "_new", type);
        foreach (System.Data.DataRow dr in dt.Rows)
        {   // Will need switch Case for others if Date is not the only one.
            dr[p + "_new"] =DateTime.FromOADate(double.Parse(dr[p].ToString())); // dr[p].ToString();
        }
        dt.Columns.Remove(p);
        dt.Columns[p + "_new"].ColumnName = p;
    }

appcompat-v7:21.0.0': No resource found that matches the given name: attr 'android:actionModeShareDrawable'

In case you don't want to use API 21 as the target API, and thus you don' t want to use the Material Theme, you have to use an older revision belonging to API 19 >

compile "com.android.support:appcompat-v7:19.0.+"

This also helps solving your problem, it only depends on what you want to achieve.

Substitute a comma with a line break in a cell

For some reason, none of the above worked for me. This DID however:

  1. Selected the range of cells I needed to replace.
  2. Go to Home > Find & Select > Replace or Ctrl + H
  3. Find what: ,
  4. Replace with: CTRL + SHIFT + J
  5. Click Replace All

Somehow CTRL + SHIFT + J is registered as a linebreak.

Redirect stdout to a file in Python?

Programs written in other languages (e.g. C) have to do special magic (called double-forking) expressly to detach from the terminal (and to prevent zombie processes). So, I think the best solution is to emulate them.

A plus of re-executing your program is, you can choose redirections on the command-line, e.g. /usr/bin/python mycoolscript.py 2>&1 1>/dev/null

See this post for more info: What is the reason for performing a double fork when creating a daemon?

How to quickly edit values in table in SQL Server Management Studio?

Brendan is correct. You can edit the Select command to edit a filtered list of records. For instance "WHERE dept_no = 200".

How can I declare a two dimensional string array?

There are 2 types of multidimensional arrays in C#, called Multidimensional and Jagged.

For multidimensional you can by:

string[,] multi = new string[3, 3];

For jagged array you have to write a bit more code:

string[][] jagged = new string[3][];
            for (int i = 0; i < jagged.Length; i++)
            {
                jagged[i] = new string[3];
            }

In short jagged array is both faster and has intuitive syntax. For more information see: this Stackoverflow question

HTML select form with option to enter custom value

Alen Saqe's latest JSFiddle didn't toggle for me on Firefox, so I thought I would provide a simple html/javascript workaround that will function nicely within forms (regarding submission) until the day that the datalist tag is accepted by all browsers/devices. For more details and see it in action, go to: http://jsfiddle.net/6nq7w/4/ Note: Do not allow any spaces between toggling siblings!

<!DOCTYPE html>
<html>
<script>
function toggleField(hideObj,showObj){
  hideObj.disabled=true;        
  hideObj.style.display='none';
  showObj.disabled=false;   
  showObj.style.display='inline';
  showObj.focus();
}
</script>
<body>
<form name="BrowserSurvey" action="#">
Browser: <select name="browser" 
          onchange="if(this.options[this.selectedIndex].value=='customOption'){
              toggleField(this,this.nextSibling);
              this.selectedIndex='0';
          }">
            <option></option>
            <option value="customOption">[type a custom value]</option>
            <option>Chrome</option>
            <option>Firefox</option>
            <option>Internet Explorer</option>
            <option>Opera</option>
            <option>Safari</option>
        </select><input name="browser" style="display:none;" disabled="disabled" 
            onblur="if(this.value==''){toggleField(this,this.previousSibling);}">
<input type="submit" value="Submit">
</form>
</body>
</html>

Parse JSON String into List<string>

Since you are using JSON.NET, personally I would go with serialization so that you can have Intellisense support for your object. You'll need a class that represents your JSON structure. You can build this by hand, or you can use something like json2csharp to generate it for you:

e.g.

public class Person
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

public class RootObject
{
    public List<Person> People { get; set; }
}

Then, you can simply call JsonConvert's methods to deserialize the JSON into an object:

RootObject instance = JsonConvert.Deserialize<RootObject>(json);

Then you have Intellisense:

var firstName = instance.People[0].FirstName;
var lastName = instance.People[0].LastName;

Refresh Part of Page (div)

$.ajax(), $.get(), $.post(), $.load() functions of jQuery internally send XML HTTP request. among these the load() is only dedicated for a particular DOM Element. See jQuery Ajax Doc. A details Q.A. on these are Here .

get next and previous day with PHP

just in case if you want next day or previous day from today's date

date("Y-m-d", mktime(0, 0, 0, date("m"),date("d")-1,date("Y")));

just change the "-1" to the "+1" regards, Yosafat

find a minimum value in an array of floats

You need to iterate the 2d array in order to get the min value of each row, then you have to push any gotten min value to another array and finally you need to get the min value of the array where each min row value was pushed

def get_min_value(self, table):
    min_values = []
    for i in range(0, len(table)):
        min_value = min(table[i])
        min_values.append(min_value)

    return min(min_values)

Best way to randomize an array with .NET

 
Random r = new Random();
List<string> list = new List(originalArray);
List<string> randomStrings = new List();

while(list.Count > 0)
{
int i = r.Random(list.Count);
randomStrings.Add(list[i]);
list.RemoveAt(i);
}

How to get table list in database, using MS SQL 2008?

Answering the question in your title, you can query sys.tables or sys.objects where type = 'U' to check for the existence of a table. You can also use OBJECT_ID('table_name', 'U'). If it returns a non-null value then the table exists:

IF (OBJECT_ID('dbo.My_Table', 'U') IS NULL)
BEGIN
    CREATE TABLE dbo.My_Table (...)
END

You can do the same for databases with DB_ID():

IF (DB_ID('My_Database') IS NULL)
BEGIN
    CREATE DATABASE My_Database
END

If you want to create the database and then start using it, that needs to be done in separate batches. I don't know the specifics of your case, but there shouldn't be many cases where this isn't possible. In a SQL script you can use GO statements. In an application it's easy enough to send across a new command after the database is created.

The only place that you might have an issue is if you were trying to do this in a stored procedure and creating databases on the fly like that is usually a bad idea.

If you really need to do this in one batch, you can get around the issue by using EXEC to get around the parsing error of the database not existing:

CREATE DATABASE Test_DB2

IF (OBJECT_ID('Test_DB2.dbo.My_Table', 'U') IS NULL)
BEGIN
    EXEC('CREATE TABLE Test_DB2.dbo.My_Table (my_id INT)')
END

EDIT: As others have suggested, the INFORMATION_SCHEMA.TABLES system view is probably preferable since it is supposedly a standard going forward and possibly between RDBMSs.

Message: Trying to access array offset on value of type null

This happens because $cOTLdata is not null but the index 'char_data' does not exist. Previous versions of PHP may have been less strict on such mistakes and silently swallowed the error / notice while 7.4 does not do this anymore.

To check whether the index exists or not you can use isset():

isset($cOTLdata['char_data'])

Which means the line should look something like this:

$len = isset($cOTLdata['char_data']) ? count($cOTLdata['char_data']) : 0;

Note I switched the then and else cases of the ternary operator since === null is essentially what isset already does (but in the positive case).

How to export data with Oracle SQL Developer?

In version 3, they changed "export" to "unload". It still functions more or less the same.

Isn't the size of character in Java 2 bytes?

Java stores all it's "chars" internally as two bytes. However, when they become strings etc, the number of bytes will depend on your encoding.

Some characters (ASCII) are single byte, but many others are multi-byte.

Java supports Unicode, thus according to:

Java Character Docs

The max value supported is "\uFFFF" (hex FFFF, dec 65535), or 11111111 11111111 binary (two bytes).

Show Error on the tip of the Edit Text Android

I know it's too late, but in case someone still need help. Here is the working solution. Setting an error is pretty straight forward. But it will be displayed to user, when he request Focus on it. So to do the both thing on your own, User this code. 

 firstName.setError("Enter FirstName");
 firstName.requestFocus();

converting string to long in python

longcan only take string convertibles which can end in a base 10 numeral. So, the decimal is causing the harm. What you can do is, float the value before calling the long. If your program is on Python 2.x where int and long difference matters, and you are sure you are not using large integers, you could have just been fine with using int to provide the key as well.

So, the answer is long(float('234.89')) or it could just be int(float('234.89')) if you are not using large integers. Also note that this difference does not arise in Python 3, because int is upgraded to long by default. All integers are long in python3 and call to covert is just int

How to remove trailing whitespace in code, using another script?

Save as fix_whitespace.py:

#!/usr/bin/env python
"""
Fix trailing whitespace and line endings (to Unix) in a file.
Usage: python fix_whitespace.py foo.py
"""

import os
import sys


def main():
    """ Parse arguments, then fix whitespace in the given file """
    if len(sys.argv) == 2:
        fname = sys.argv[1]
        if not os.path.exists(fname):
            print("Python file not found: %s" % sys.argv[1])
            sys.exit(1)
    else:
        print("Invalid arguments. Usage: python fix_whitespace.py foo.py")
        sys.exit(1)
    fix_whitespace(fname)


def fix_whitespace(fname):
    """ Fix whitespace in a file """
    with open(fname, "rb") as fo:
        original_contents = fo.read()
    # "rU" Universal line endings to Unix
    with open(fname, "rU") as fo:
        contents = fo.read()
    lines = contents.split("\n")
    fixed = 0
    for k, line in enumerate(lines):
        new_line = line.rstrip()
        if len(line) != len(new_line):
            lines[k] = new_line
            fixed += 1
    with open(fname, "wb") as fo:
        fo.write("\n".join(lines))
    if fixed or contents != original_contents:
        print("************* %s" % os.path.basename(fname))
    if fixed:
        slines = "lines" if fixed > 1 else "line"
        print("Fixed trailing whitespace on %d %s" \
              % (fixed, slines))
    if contents != original_contents:
        print("Fixed line endings to Unix (\\n)")


if __name__ == "__main__":
    main()

Tool to convert java to c# code

For your reference:

Note: I had no experience on them.

Is there a decorator to simply cache function return values?

Along with the Memoize Example I found the following python packages:

  • cachepy; It allows to set up ttl and\or the number of calls for cached functions; Also, one can use encrypted file-based cache...
  • percache

How do I access nested HashMaps in Java?

If you plan on constructing HashMaps with variable depth, use a recursive data structure.

Below is an implementation providing a sample interface:

class NestedMap<K, V> {

    private final HashMap<K, NestedMap> child;
    private V value;

    public NestedMap() {
        child = new HashMap<>();
        value = null;
    }

    public boolean hasChild(K k) {
        return this.child.containsKey(k);
    }

    public NestedMap<K, V> getChild(K k) {
        return this.child.get(k);
    }

    public void makeChild(K k) {
        this.child.put(k, new NestedMap());
    }

    public V getValue() {
        return value;
    }

    public void setValue(V v) {
        value = v;
    }
}

and example usage:

class NestedMapIllustration {
    public static void main(String[] args) {

        NestedMap<Character, String> m = new NestedMap<>();

        m.makeChild('f');
        m.getChild('f').makeChild('o');
        m.getChild('f').getChild('o').makeChild('o');
        m.getChild('f').getChild('o').getChild('o').setValue("bar");

        System.out.println(
            "nested element at 'f' -> 'o' -> 'o' is " +
            m.getChild('f').getChild('o').getChild('o').getValue());
    }
}

What is size_t in C?

size_t is an unsigned integer data type which can assign only 0 and greater than 0 integer values. It measure bytes of any object's size and returned by sizeof operator. const is the syntax representation of size_t, but without const you can run the programm.

const size_t number;

size_t regularly used for array indexing and loop counting. If the compiler is 32-bit it would work on unsigned int. If the compiler is 64-bit it would work on unsigned long long int also. There for maximum size of size_t depending on compiler type.

size_t already define on <stdio.h> header file, but It can also define by <stddef.h>, <stdlib.h>, <string.h>, <time.h>, <wchar.h> headers.

  • Example (with const)
#include <stdio.h>

int main()
{
    const size_t value = 200;
    size_t i;
    int arr[value];

    for (i = 0 ; i < value ; ++i)
    {
        arr[i] = i;
    }

    size_t size = sizeof(arr);
    printf("size = %zu\n", size);
}

Output -: size = 800

  • Example (without const)
#include <stdio.h>

int main()
{
    size_t value = 200;
    size_t i;
    int arr[value];

    for (i = 0 ; i < value ; ++i)
    {
        arr[i] = i;
    }

    size_t size = sizeof(arr);
    printf("size = %zu\n", size);
}

Output -: size = 800

Default SQL Server Port

For Http Request Default Port number is 80

For Https Default Port Number is 443

For Sql Server Default Port Number is 1433

Making Maven run all tests, even when some fail

Try to add the following configuration for surefire plugin in your pom.xml of root project:

<project>
  [...]
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <configuration>
          <testFailureIgnore>true</testFailureIgnore>
        </configuration>
      </plugin>
    </plugins>
  </build>
  [...]
</project>

How to force cp to overwrite without confirmation

This is probably caused by cp being already aliased to something like cp -i. Calling cp directly should work:

/bin/cp -rf /zzz/zzz/* /xxx/xxx

Another way to get around this is to use the yes command:

yes | cp -rf /zzz/zzz/* /xxx/xxx

Getting request payload from POST request in Java servlet

If you are able to send the payload in JSON, this is a most convenient way to read the playload:

Example data class:

public class Person {
    String firstName;
    String lastName;
    // Getters and setters ...
}

Example payload (request body):

{ "firstName" : "John", "lastName" : "Doe" }

Code to read payload in servlet (requires com.google.gson.*):

Person person = new Gson().fromJson(request.getReader(), Person.class);

That's all. Nice, easy and clean. Don't forget to set the content-type header to application/json.

How to wait till the response comes from the $http request, in angularjs?

I was having the same problem and none if these worked for me. Here is what did work though...

app.factory('myService', function($http) {
    var data = function (value) {
            return $http.get(value);
    }

    return { data: data }
});

and then the function that uses it is...

vm.search = function(value) {

        var recieved_data = myService.data(value);

        recieved_data.then(
            function(fulfillment){
                vm.tags = fulfillment.data;
            }, function(){
                console.log("Server did not send tag data.");
        });
    };

The service isn't that necessary but I think its a good practise for extensibility. Most of what you will need for one will for any other, especially when using APIs. Anyway I hope this was helpful.

Convert HTML Character Back to Text Using Java Standard Library

I think the Apache Commons Lang library's StringEscapeUtils.unescapeHtml3() and unescapeHtml4() methods are what you are looking for. See https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/StringEscapeUtils.html.

WHERE statement after a UNION in SQL?

If you want to apply the WHERE clause to the result of the UNION, then you have to embed the UNION in the FROM clause:

SELECT *
  FROM (SELECT * FROM TableA
        UNION
        SELECT * FROM TableB
       ) AS U
 WHERE U.Col1 = ...

I'm assuming TableA and TableB are union-compatible. You could also apply a WHERE clause to each of the individual SELECT statements in the UNION, of course.

Is it possible to specify the schema when connecting to postgres with JDBC?

DataSource – setCurrentSchema

When instantiating a DataSource implementation, look for a method to set the current/default schema.

For example, on the PGSimpleDataSource class call setCurrentSchema.

org.postgresql.ds.PGSimpleDataSource dataSource = new org.postgresql.ds.PGSimpleDataSource ( );
dataSource.setServerName ( "localhost" );
dataSource.setDatabaseName ( "your_db_here_" );
dataSource.setPortNumber ( 5432 );
dataSource.setUser ( "postgres" );
dataSource.setPassword ( "your_password_here" );
dataSource.setCurrentSchema ( "your_schema_name_here_" );  // <----------

If you leave the schema unspecified, Postgres defaults to a schema named public within the database. See the manual, section 5.9.2 The Public Schema. To quote hat manual:

In the previous sections we created tables without specifying any schema names. By default such tables (and other objects) are automatically put into a schema named “public”. Every new database contains such a schema.

Selecting a Linux I/O Scheduler

As documented in /usr/src/linux/Documentation/block/switching-sched.txt, the I/O scheduler on any particular block device can be changed at runtime. There may be some latency as the previous scheduler's requests are all flushed before bringing the new scheduler into use, but it can be changed without problems even while the device is under heavy use.

# cat /sys/block/hda/queue/scheduler
noop deadline [cfq]
# echo anticipatory > /sys/block/hda/queue/scheduler
# cat /sys/block/hda/queue/scheduler
noop [deadline] cfq

Ideally, there would be a single scheduler to satisfy all needs. It doesn't seem to exist yet. The kernel often doesn't have enough knowledge to choose the best scheduler for your workload:

  • noop is often the best choice for memory-backed block devices (e.g. ramdisks) and other non-rotational media (flash) where trying to reschedule I/O is a waste of resources
  • deadline is a lightweight scheduler which tries to put a hard limit on latency
  • cfq tries to maintain system-wide fairness of I/O bandwidth

The default was anticipatory for a long time, and it received a lot of tuning, but was removed in 2.6.33 (early 2010). cfq became the default some while ago, as its performance is reasonable and fairness is a good goal for multi-user systems (and even single-user desktops). For some scenarios -- databases are often used as examples, as they tend to already have their own peculiar scheduling and access patterns, and are often the most important service (so who cares about fairness?) -- anticipatory has a long history of being tunable for best performance on these workloads, and deadline very quickly passes all requests through to the underlying device.

Android and Facebook share intent

The easiest way that I could find to pass a message from my app to facebook was programmatically copy to the clipboard and alert the user that they have the option to paste. It saves the user from manually doing it; my app is not pasting but the user might.

...
if (app.equals("facebook")) {
    // overcome fb 'putExtra' constraint;
    // copy message to clipboard for user to paste into fb.
    ClipboardManager cb = (ClipboardManager) 
            getSystemService(Context.CLIPBOARD_SERVICE);
    ClipData clip = ClipData.newPlainText("post", msg);
    cb.setPrimaryClip(clip);

    // tell the to PASTE POST with option to stop showing this dialogue
    showDialog(this, getString(R.string.facebook_post));
}
startActivity(appIntent);
...

Scala: write string to file in one statement

Through the magic of the semicolon, you can make anything you like a one-liner.

import java.io.PrintWriter
import java.nio.file.Files
import java.nio.file.Paths
import java.nio.charset.StandardCharsets
import java.nio.file.StandardOpenOption
val outfile = java.io.File.createTempFile("", "").getPath
val outstream = new PrintWriter(Files.newBufferedWriter(Paths.get(outfile)
  , StandardCharsets.UTF_8
  , StandardOpenOption.WRITE)); outstream.println("content"); outstream.flush(); outstream.close()

Check if an apt-get package is installed and then install it if it's not on Linux

This command is the most memorable:

dpkg --get-selections <package-name>

If it's installed it prints:

<package-name> install

Otherwise it prints

No packages found matching <package-name>.

This was tested on Ubuntu 12.04.1 (Precise Pangolin).

C# - How to add an Excel Worksheet programmatically - Office XP / 2003

Here are a couple things I figured out:

  1. You can't open more than one instance of the same object at the same time. For Example if you instanciate a new excel sheet object called xlsheet1 you have to release it before creating another excel sheet object ex xlsheet2. It seem as COM looses track of the object and leaves a zombie process on the server.

  2. Using the open method associated with excel.workbooks also becomes difficult to close if you have multiple users accessing the same file. Use the Add method instead, it works just as good without locking the file. eg. xlBook = xlBooks.Add("C:\location\XlTemplate.xls")

  3. Place your garbage collection in a separate block or method after releasing the COM objects.

MySQL Join Where Not Exists

I'd probably use a LEFT JOIN, which will return rows even if there's no match, and then you can select only the rows with no match by checking for NULLs.

So, something like:

SELECT V.*
FROM voter V LEFT JOIN elimination E ON V.id = E.voter_id
WHERE E.voter_id IS NULL

Whether that's more or less efficient than using a subquery depends on optimization, indexes, whether its possible to have more than one elimination per voter, etc.

exporting multiple modules in react.js

When you

import App from './App.jsx';

That means it will import whatever you export default. You can rename App class inside App.jsx to whatever you want as long as you export default it will work but you can only have one export default.

So you only need to export default App and you don't need to export the rest.

If you still want to export the rest of the components, you will need named export.

https://developer.mozilla.org/en/docs/web/javascript/reference/statements/export

Is it possible to use a batch file to establish a telnet session, send a command and have the output written to a file?

This is old, but someone else may stumble on it as I did. When you connect to the DataCast, you are talking to a daemon that can access the database. It was intended that a customer would write some code to access the database and store the results somewhere. It just happens that telnet works to access data manually. netcat should also work. ssh obviously will not.

How to get the integer value of day of week

 
int day = (int)DateTime.Now.DayOfWeek;

First day of the week: Sunday (with a value of zero)

How to secure MongoDB with username and password

First run mongoDB on terminal using

mongod

now run mongo shell use following commands

    use admin
db.createUser(
  {
    user: "myUserAdmin",
    pwd: "abc123",
    roles: [ { role: "userAdminAnyDatabase", db: "admin" } ]
  }
)

Re-start the MongoDB instance with access control.

mongod --auth

Now authenticate yourself from the command line using 

mongo --port 27017 -u "myUserAdmin" -p "abc123" --authenticationDatabase "admin"

I read it from

https://docs.mongodb.com/manual/tutorial/enable-authentication/

Please help me convert this script to a simple image slider

Problems only surface when I am I trying to give the first loaded content an active state

Does this mean that you want to add a class to the first button?

$('.o-links').click(function(e) {   // ... }).first().addClass('O_Nav_Current');

instead of using IDs for the slider's items and resetting html contents you can use classes and indexes:

CSS:

.image-area {     width: 100%;     height: auto;     display: none; }  .image-area:first-of-type {     display: block; }

JavaScript:

var $slides = $('.image-area'),     $btns = $('a.o-links');  $btns.on('click', function (e) {     var i = $btns.removeClass('O_Nav_Current').index(this);     $(this).addClass('O_Nav_Current');      $slides.filter(':visible').fadeOut(1000, function () {         $slides.eq(i).fadeIn(1000);     });      e.preventDefault();  }).first().addClass('O_Nav_Current');

http://jsfiddle.net/RmF57/

Specifying colClasses in the read.csv

I know OP asked about the utils::read.csv function, but let me provide an answer for these that come here searching how to do it using readr::read_csv from the tidyverse.

read_csv ("test.csv", col_names=FALSE, col_types = cols (.default = "c", time = "i"))

This should set the default type for all columns as character, while time would be parsed as integer.

How to make several plots on a single page using matplotlib?

This works also:

for i in range(19):
    plt.subplot(5,4,i+1)

It plots 19 total graphs on one page. The format is 5 down and 4 across..

Update row with data from another row in the same table

 
Update MyTable
Set Value = (
                Select Min( T2.Value )
                From MyTable As T2
                Where T2.Id <> MyTable.Id
                    And T2.Name = MyTable.Name
                )
Where ( Value Is Null Or Value = '' )
    And Exists  (
                Select 1
                From MyTable As T3
                Where T3.Id <> MyTable.Id
                    And T3.Name = MyTable.Name
                )

Convert comma separated string to array in PL/SQL

Oracle provides the builtin function DBMS_UTILITY.COMMA_TO_TABLE.

Unfortunately, this one doesn't work with numbers:

SQL> declare
  2    l_input varchar2(4000) := '1,2,3';
  3    l_count binary_integer;
  4    l_array dbms_utility.lname_array;
  5  begin
  6    dbms_utility.comma_to_table
  7    ( list   => l_input
  8    , tablen => l_count
  9    , tab    => l_array
 10    );
 11    dbms_output.put_line(l_count);
 12    for i in 1 .. l_count
 13    loop
 14      dbms_output.put_line
 15      ( 'Element ' || to_char(i) ||
 16        ' of array contains: ' ||
 17        l_array(i)
 18      );
 19    end loop;
 20  end;
 21  /
declare
*
ERROR at line 1:
ORA-00931: missing identifier
ORA-06512: at "SYS.DBMS_UTILITY", line 132
ORA-06512: at "SYS.DBMS_UTILITY", line 164
ORA-06512: at "SYS.DBMS_UTILITY", line 218
ORA-06512: at line 6

But with a little trick to prefix the elements with an 'x', it works:

SQL> declare
  2    l_input varchar2(4000) := '1,2,3';
  3    l_count binary_integer;
  4    l_array dbms_utility.lname_array;
  5  begin
  6    dbms_utility.comma_to_table
  7    ( list   => regexp_replace(l_input,'(^|,)','\1x')
  8    , tablen => l_count
  9    , tab    => l_array
 10    );
 11    dbms_output.put_line(l_count);
 12    for i in 1 .. l_count
 13    loop
 14      dbms_output.put_line
 15      ( 'Element ' || to_char(i) ||
 16        ' of array contains: ' ||
 17        substr(l_array(i),2)
 18      );
 19    end loop;
 20  end;
 21  /
3
Element 1 of array contains: 1
Element 2 of array contains: 2
Element 3 of array contains: 3

PL/SQL procedure successfully completed.

Regards, Rob.

Is there a CSS parent selector?

I don’t think you can select the parent in CSS only.

But as you already seem to have an .active class, it would be easier to move that class to the li (instead of the a). That way you can access both the li and the a via CSS only.

JQuery add class to parent element

 
$(this.parentNode).addClass('newClass');

Python division

Make at least one of them float, then it will be float division, not integer:

>>> (20.0-10) / (100-10)
0.1111111111111111

Casting the result to float is too late.

jquery change style of a div on click

you can use .css method of jquery..

reference css method

How can I open a link in a new window?

Here's how to force the target inside a click handler:

$('a#link_id').click(function() {
    $(this).attr('target', '_blank');
});

How do I fix the multiple-step OLE DB operation errors in SSIS?

Also check if the script has no batch seperator commands (remove the 'GO' statements on a single line).

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '<

Very simple question that you can solved it easily ,

Please follow my step : change < to ( and >; to );

Just use: (

     );

enter code here

` CREATE TABLE information (
-> id INT(11) NOT NULL AUTO_INCREMENT,
-> name VARCHAR(30) NOT NULL,
-> age INT(10) NOT NULL,
-> salary INT(100) NOT NULL,
-> address VARCHAR(100) NOT NULL,
-> PRIMARY KEY(id)
-> );`

How to get the list of files in a directory in a shell script?

 
for entry in "$search_dir"/*
do
  echo "$entry"
done

Fancybox doesn't work with jQuery v1.9.0 [ f.browser is undefined / Cannot read property 'msie' ]

Hi this is due to new version of the jQuery => 1.9.0

you can check the update : http://blog.jquery.com/2013/01/15/jquery-1-9-final-jquery-2-0-beta-migrate-final-released/

jQuery.Browser is deprecated. you can keep latest version by adding a migration script : http://code.jquery.com/jquery-migrate-1.0.0.js

replace :

<script src="http://code.jquery.com/jquery-latest.js"></script>

by :

<script src="http://code.jquery.com/jquery-latest.js"></script>
<script src="http://code.jquery.com/jquery-migrate-1.0.0.js"></script>

in your page and its working.

Setting HTTP headers

I know this is a different twist on the answer, but isn't this more of a concern for a web server? For example, nginx, could help.

The ngx_http_headers_module module allows adding the “Expires” and “Cache-Control” header fields, and arbitrary fields, to a response header

...

location ~ ^<REGXP MATCHING CORS ROUTES> {
    add_header Access-Control-Allow-Methods POST
    ...
}
...

Adding nginx in front of your go service in production seems wise. It provides a lot more feature for authorizing, logging,and modifying requests. Also, it gives the ability to control who has access to your service and not only that but one can specify different behavior for specific locations in your app, as demonstrated above.

I could go on about why to use a web server with your go api, but I think that's a topic for another discussion.

Use xml.etree.ElementTree to print nicely formatted xml files

You can use the function toprettyxml() from xml.dom.minidom in order to do that:

def prettify(elem):
    """Return a pretty-printed XML string for the Element.
    """
    rough_string = ElementTree.tostring(elem, 'utf-8')
    reparsed = minidom.parseString(rough_string)
    return reparsed.toprettyxml(indent="\t")

The idea is to print your Element in a string, parse it using minidom and convert it again in XML using the toprettyxml function.

Source: http://pymotw.com/2/xml/etree/ElementTree/create.html

How do I include a path to libraries in g++

To specify a directory to search for (binary) libraries, you just use -L:

-L/data[...]/lib

To specify the actual library name, you use -l:

-lfoo  # (links libfoo.a or libfoo.so)

To specify a directory to search for include files (different from libraries!) you use -I:

-I/data[...]/lib

So I think what you want is something like

g++ -g -Wall -I/data[...]/lib testing.cpp fileparameters.cpp main.cpp -o test

These compiler flags (amongst others) can also be found at the GNU GCC Command Options manual:

How do I add an active class to a Link from React Router?

To set class on the active navigation element

import { NavLink } from 'react-router-dom';

&

<NavLink to="/Home" activeClassName="active">Home</NavLink>

How can I use ":" as an AWK field separator?

If you want to do it programatically, you can use the FS variable:

echo "1: " | awk 'BEGIN { FS=":" } /1/ { print $1 }'

Note that if you change it in the main loop rather than the BEGIN loop, it takes affect for the next line read in, since the current line has already been split.

How do I compile a Visual Studio project from the command-line?

MSBuild usually works, but I've run into difficulties before. You may have better luck with

devenv YourSolution.sln /Build

Shuffling a list of objects

It took me some time to get that too. But the documentation for shuffle is very clear:

shuffle list x in place; return None.

So you shouldn't print(random.shuffle(b)). Instead do random.shuffle(b) and then print(b).

Facebook OAuth "The domain of this URL isn't included in the app's domain"

Facebook Login -> Settings -> Valid OAuth redirect URIs -> insert the domains of your redirect url, remember you should add 'https' or http. eg: if your redirect url is https://xxx.xxx.com/path/callback.do, you only need to enter https://xxx.xxx.com/, it's ok for me.

Output to the same line overwriting previous output?

I found that for a simple print statement in python 2.7, just put a comma at the end after your '\r'.

print os.path.getsize(file_name)/1024, 'KB / ', size, 'KB downloaded!\r',

This is shorter than other non-python 3 solutions, but also more difficult to maintain.

How to display .svg image using swift

You can use this pod called 'SVGParser'. https://cocoapods.org/pods/SVGParser.

After adding it in your pod file, all you have to do is to import this module to the class that you want to use it. You should show the SVG image in an ImageView.

There are three cases you can show this SVGimage:

  1. Load SVG from local path as Data
  2. Load SVG from local path
  3. Load SVG from remote URL

You can also find an example project in GitHub: https://github.com/AndreyMomot/SVGParser. Just download the project and run it to see how it works.

How to determine previous page URL in Angular?

I had some struggle to access the previous url inside a guard.
Without implementing a custom solution, this one is working for me.

public constructor(private readonly router: Router) {
};

public ngOnInit() {
   this.router.getCurrentNavigation().previousNavigation.initialUrl.toString();
}

The initial url will be the previous url page.

Why does JSON.parse fail with the empty string?

JSON.parse expects valid notation inside a string, whether that be object {}, array [], string "" or number types (int, float, doubles).

If there is potential for what is parsing to be an empty string then the developer should check for it.

If it was built into the function it would add extra cycles, since built in functions are expected to be extremely performant, it makes sense to not program them for the race case.

How can I remove a style added with .css() function?

This is more complex than some other solutions, but may offer more flexibility in scenarios:

1) Make a class definition to isolate (encapsulate) the styling you want to apply/remove selectively. It can be empty (and for this case, probably should be):

.myColor {}

2) use this code, based on http://jsfiddle.net/kdp5V/167/ from this answer by gilly3:

function changeCSSRule(styleSelector,property,value) {
    for (var ssIdx = 0; ssIdx < document.styleSheets.length; ssIdx++) {
        var ss = document.styleSheets[ssIdx];
        var rules = ss.cssRules || ss.rules;
        if(rules){
            for (var ruleIdx = 0; ruleIdx < rules.length; ruleIdx++) {
                var rule = rules[ruleIdx];
                if (rule.selectorText == styleSelector) {
                    if(typeof value == 'undefined' || !value){
                        rule.style.removeProperty(property);
                    } else {
                        rule.style.setProperty(property,value);
                    }
                    return; // stops at FIRST occurrence of this styleSelector
                }
            }
        }
    }
}

Usage example: http://jsfiddle.net/qvkwhtow/

Caveats:

  • Not extensively tested.
  • Can't include !important or other directives in the new value. Any such existing directives will be lost through this manipulation.
  • Only changes first found occurrence of a styleSelector. Doesn't add or remove entire styles, but this could be done with something more elaborate.
  • Any invalid/unusable values will be ignored or throw error.
  • In Chrome (at least), non-local (as in cross-site) CSS rules are not exposed through document.styleSheets object, so this won't work on them. One would have to add a local overrides and manipulate that, keeping in mind the "first found" behavior of this code.
  • document.styleSheets is not particularly friendly to manipulation in general, don't expect this to work for aggressive use.

Isolating the styling this way is what CSS is all about, even if manipulating it isn't. Manipulating CSS rules is NOT what jQuery is all about, jQuery manipulates DOM elements, and uses CSS selectors to do it.

SQL Server: how to create a stored procedure

To Create SQL server Store procedure in SQL server management studio

  • Expand your database
  • Expand programmatically
  • Right-click on Stored-procedure and Select "new Stored Procedure"

Now, Write your Store procedure, for example, it can be something like below

USE DatabaseName;  
GO  
CREATE PROCEDURE ProcedureName 
 @LastName nvarchar(50),   
 @FirstName nvarchar(50)   
AS   

SET NOCOUNT ON;  
 
//Your SQL query here, like
Select  FirstName, LastName, Department  
FROM HumanResources.vEmployeeDepartmentHistory  
WHERE FirstName = @FirstName AND LastName = @LastName  
GO

Where, DatabaseName = name of your database
ProcedureName = name of SP
InputValue = your input parameter value (@LastName and @FirstName) and type = parameter type example nvarchar(50) etc.

Source: Stored procedure in sql server (With Example)

To Execute the above stored procedure you can use sample query as below

EXECUTE ProcedureName @FirstName = N'Pilar', @LastName = N'Ackerman';

Please initialize the log4j system properly warning

From the link in the error message:

This occurs when the default configuration files log4j.properties and log4j.xml can not be found and the application performs no explicit configuration. log4j uses Thread.getContextClassLoader().getResource() to locate the default configuration files and does not directly check the file system. Knowing the appropriate location to place log4j.properties or log4j.xml requires understanding the search strategy of the class loader in use. log4j does not provide a default configuration since output to the console or to the file system may be prohibited in some environments. Also see FAQ: Why can't log4j find my properties in a J2EE or WAR application?.

The configuration file cannot be found. Are you using xml or a property file??

Also, use logback!

How to automatically generate getters and setters in Android Studio

use code=>generate=>getter() and setter() dialog ,select all the variables ,generate all the getter(),setter() methods at one time.

Regular expression to find URLs within a string

I use this Regex:

/((\w+:\/\/\S+)|(\w+[\.:]\w+\S+))[^\s,\.]/ig

It works fine for many URLs, like: http://google.com, https://dev-site.io:8080/home?val=1&count=100, www.regexr.com, localhost:8080/path, ...

How to split strings over multiple lines in Bash?

This isn't exactly what the user asked, but another way to create a long string that spans multiple lines is by incrementally building it up, like so:

$ greeting="Hello"
$ greeting="$greeting, World"
$ echo $greeting
Hello, World

Obviously in this case it would have been simpler to build it one go, but this style can be very lightweight and understandable when dealing with longer strings.

endsWith in JavaScript

This is the implementation of endsWith:

String.prototype.endsWith = function (str) {
  return (this.length >= str.length) && (this.substr(this.length - str.length) === str);
}

How to update Xcode from command line

I encountered the same issue when I uninstalled the complete version of Xcode to reinstall the CLI version. My fix was:

sudo xcode-select -s /Library/Developer/CommandLineTools

Smooth scrolling when clicking an anchor link

I did this for both "/xxxxx#asdf" and "#asdf" href anchors

$("a[href*=#]").on('click', function(event){
    var href = $(this).attr("href");
    if ( /(#.*)/.test(href) ){
      var hash = href.match(/(#.*)/)[0];
      var path = href.match(/([^#]*)/)[0];

      if (window.location.pathname == path || path.length == 0){
        event.preventDefault();
        $('html,body').animate({scrollTop:$(this.hash).offset().top}, 1000);
        window.location.hash = hash;
      }
    }
});

SSL certificate rejected trying to access GitHub over HTTPS behind firewall

Feel free to skip past this answer if you want to fix the certificates issue. This answer deals with tunneling ssh through the firewall which is IMHO a better solution to dealing with firewall/proxy thingies.

There is a better way than using http access and that is to use the ssh service offered by github on port 443 of the ssh.github.com server.

We use a tool called corkscrew. This is available for both CygWin (through setup from the cygwin homepage) and Linux using your favorite packaging tool. For MacOSX it is available from macports and brew at least.

The commandline is as follows :

$ corkscrew <proxyhost> <proxyport> <targethost> <targetport> <authfile>

The proxyhost and proxyport are the coordinates of the https proxy. The targethost and targetport is the location of the host to tunnel to. The authfile is a textfile with 1 line containing your proxy server username/password separated by a colon

e.g:

abc:very_secret

Installation for using "normal" ssh protocol for git communication

By adding this to the ~/.ssh/config this trick can be used for normal ssh connections.

Host github.com
  HostName ssh.github.com
  Port 443
  User git
  ProxyCommand corkscrew <proxyhost> <proxyport> %h %p ~/.ssh/proxy_auth

now you can test it works by ssh-ing to gitproxy

pti@pti-laptop:~$ ssh github.com
PTY allocation request failed on channel 0
Hi ptillemans! You've successfully authenticated, but GitHub does not provide shell access.
       Connection to github.com closed.
pti@pti-laptop:~$

(Note: if you never logged in to github before, ssh will be asking to add the server key to the known hosts file. If you are paranoid, it is recommended to verify the RSA fingerprint to the one shown on the github site where you uploaded your key).

A slight variant on this method is the case when you need to access a repository with another key, e.g. to separate your private account from your professional account. 

# 
# account dedicated for the ACME private github account 
#
Host acme.github.com
  User git
  HostName ssh.github.com
  Port 443
  ProxyCommand corkscrew <proxyhost> <3128> %h %p ~/.ssh/proxy_auth
  IdentityFile ~/.ssh/id_dsa_acme

enjoy!

We've been using this for years now on both Linux, Macs and Windows.

If you want you can read more about it in this blog post

ImportError: No module named win32com.client

I realize this post is old but I wanted to add that I had to take an extra step to get this to work.

Instead of just doing:

pip install pywin32

I had use use the -m flag to get this to work properly. Without it I was running into an issue where I was still getting the error ImportError: No module named win32com.

So to fix this you can give this a try:

python -m pip install pywin32

This worked for me and has worked on several version of python where just doing pip install pywin32 did not work.

Versions tested on:

3.6.2, 3.7.6, 3.8.0, 3.9.0a1.

Submitting HTML form using Jquery AJAX

If you add:

jquery.form.min.js

You can simply do this:

<script>
$('#myform').ajaxForm(function(response) {
  alert(response);
});

// this will register the AJAX for <form id="myform" action="some_url">
// and when you submit the form using <button type="submit"> or $('myform').submit(), then it will send your request and alert response
</script>

NOTE:

You could use simple $('FORM').serialize() as suggested in post above, but that will not work for FILE INPUTS... ajaxForm() will.

How to save a PNG image server-side, from a base64 data string

It's simple :

Let's imagine that you are trying to upload a file within js framework, ajax request or mobile application (Client side)

  1. Firstly you send a data attribute that contains a base64 encoded string.
  2. In the server side you have to decode it and save it in a local project folder.

Here how to do it using PHP

<?php 

$base64String = "kfezyufgzefhzefjizjfzfzefzefhuze"; // I put a static base64 string, you can implement you special code to retrieve the data received via the request.

$filePath = "/MyProject/public/uploads/img/test.png";

file_put_contents($filePath, base64_decode($base64String));

?>

What are the "spec.ts" files generated by Angular CLI for?

The .spec.ts files are for unit tests for individual components. You can run Karma task runner through ng test. In order to see code coverage of unit test cases for particular components run ng test --code-coverage

How do I format {{$timestamp}} as MM/DD/YYYY in Postman?

In PostMan we have ->Pre-request Script. Paste the Below snippet.

const dateNow = new Date();
postman.setGlobalVariable("todayDate", dateNow.toLocaleDateString());

And now we are ready to use.

{
"firstName": "SANKAR",
"lastName": "B",
"email": "[email protected]",
"creationDate": "{{todayDate}}"
}

If you are using JPA Entity classes then use the below snippet

    @JsonFormat(pattern="MM/dd/yyyy")
    @Column(name = "creation_date")
    private Date creationDate;

enter image description here enter image description here

The name 'controlname' does not exist in the current context

Check your code behind file name and Inherits property on the @Page directive, make sure they both match.

How to install lxml on Ubuntu

As @Pepijn commented on @Druska 's answer, on ubuntu 13.04 x64, there is no need to use lib32z1-dev, zlib1g-dev is enough:

sudo apt-get install libxml2-dev libxslt-dev python-dev zlib1g-dev

CSS: 100% width or height while keeping aspect ratio?

Some years later, looking for the same requirement, I found a CSS option using background-size.

It is supposed to work in modern browsers (IE9+).

<div id="container" style="background-image:url(myimage.png)">
</div>

And the style:

#container
{
  width:  100px; /*or 70%, or what you want*/
  height: 200px; /*or 70%, or what you want*/
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}

The reference: http://www.w3schools.com/cssref/css3_pr_background-size.asp

And the demo: http://www.w3schools.com/cssref/playit.asp?filename=playcss_background-size

Is it possible to create a File object from InputStream

Create a temp file first.

File tempFile = File.createTempFile(prefix, suffix);
tempFile.deleteOnExit();
FileOutputStream out = new FileOutputStream(tempFile);
IOUtils.copy(in, out);
return tempFile;

Event on a disabled input

I find another solution:

<input type="text" class="disabled" name="test" value="test" />

Class "disabled" immitate disabled element by opacity: 

<style type="text/css">
    input.disabled {
        opacity: 0.5;
    }
</style>

And then cancel the event if element is disabled and remove class:

$(document).on('click','input.disabled',function(event) {
    event.preventDefault();
    $(this).removeClass('disabled');
});

Postgresql - unable to drop database because of some auto connections to DB

GUI solution using pgAdmin 4

First enable show activity on dashboard if you haven't:

File > Preferences > Dashboards > Display > Show Activity > true

Now disable all the processes using the db:

  1. Click the DB name
  2. Click Dashboard > Sessions
  3. Click refresh icon
  4. Click the delete (x) icon beside each process to end them

You should now be able to delete the db.

How to select top n rows from a datatable/dataview in ASP.NET

 
public DataTable TopDataRow(DataTable dt, int count)
    {
        DataTable dtn = dt.Clone();
        int i = 0;
        foreach (DataRow row in dt.Rows)
        {
            if (i < count)
            {
                dtn.ImportRow(row);
                i++;
            }
            if (i > count)
                break;
        }
        return dtn;
    }

How to resume Fragment from BackStack if exists

I know this is quite late to answer this question but I resolved this problem by myself and thought worth sharing it with everyone.`

public void replaceFragment(BaseFragment fragment) {
    FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
    final FragmentManager fManager = getSupportFragmentManager();
    BaseFragment fragm = (BaseFragment) fManager.findFragmentByTag(fragment.getFragmentTag());
    transaction.setCustomAnimations(R.anim.enter_from_right, R.anim.exit_to_left, R.anim.enter_from_left, R.anim.exit_to_right);

    if (fragm == null) {  //here fragment is not available in the stack
        transaction.replace(R.id.container, fragment, fragment.getFragmentTag());
        transaction.addToBackStack(fragment.getFragmentTag());
    } else { 
        //fragment was found in the stack , now we can reuse the fragment
        // please do not add in back stack else it will add transaction in back stack
        transaction.replace(R.id.container, fragm, fragm.getFragmentTag()); 
    }
    transaction.commit();
}

And in the onBackPressed()

 @Override
public void onBackPressed() {
    if(getSupportFragmentManager().getBackStackEntryCount()>1){
        super.onBackPressed();
    }else{
        finish();
    }
}

How to check the multiple permission at single request in Android M?

As said earlier, currently every permission group has own permission dialog which must be called separately.

You will have different dialog boxes for each permission group but you can surely check the result together in onRequestPermissionsResult() callback method.

Here is a working example link, may be useful for someone.

How do I redirect to another webpage?

I also think that location.replace(URL) is the best way, but if you want to notify the search engines about your redirection (they don't analyze JavaScript code to see the redirection) you should add the rel="canonical" meta tag to your website.

Adding a noscript section with a HTML refresh meta tag in it, is also a good solution. I suggest you to use this JavaScript redirection tool to create redirections. It also has Internet Explorer support to pass the HTTP referrer.

Sample code without delay looks like this:

<!-- Place this snippet right after opening the head tag to make it work properly -->

<!-- This code is licensed under GNU GPL v3 -->
<!-- You are allowed to freely copy, distribute and use this code, but removing author credit is strictly prohibited -->
<!-- Generated by http://insider.zone/tools/client-side-url-redirect-generator/ -->

<!-- REDIRECTING STARTS -->
<link rel="canonical" href="https://yourdomain.com/"/>
<noscript>
    <meta http-equiv="refresh" content="0;URL=https://yourdomain.com/">
</noscript>
<!--[if lt IE 9]><script type="text/javascript">var IE_fix=true;</script><![endif]-->
<script type="text/javascript">
    var url = "https://yourdomain.com/";
    if(typeof IE_fix != "undefined") // IE8 and lower fix to pass the http referer
    {
        document.write("redirecting..."); // Don't remove this line or appendChild() will fail because it is called before document.onload to make the redirect as fast as possible. Nobody will see this text, it is only a tech fix.
        var referLink = document.createElement("a");
        referLink.href = url;
        document.body.appendChild(referLink);
        referLink.click();
    }
    else { window.location.replace(url); } // All other browsers
</script>
<!-- Credit goes to http://insider.zone/ -->
<!-- REDIRECTING ENDS -->

Best Way to Refresh Adapter/ListView on Android

Following code works perfect for me

EfficientAdapter adp = (EfficientAdapter) QuickList.getAdapter();
adp.UpdateDataList(EfficientAdapter.MY_DATA);
adp.notifyDataSetChanged();
QuickList.invalidateViews();
QuickList.scrollBy(0, 0);

How to write file in UTF-8 format?

This is quite useful question. I think that my solution on Windows 10 PHP7 is rather useful for people who have yet some UTF-8 conversion trouble.

Here are my steps. The PHP script calling the following function, here named utfsave.php must have UTF-8 encoding itself, this can be easily done by conversion on UltraEdit.

In utfsave.php, we define a function calling PHP fopen($filename, "wb"), ie, it's opened in both w write mode, and especially with b in binary mode.

<?php
//
//  UTF-8 ??:
//
// fnc001: save string as a file in UTF-8:
// The resulting file is UTF-8 only if $strContent is,
// with French accents, chinese ideograms, etc..
//
function entSaveAsUtf8($strContent, $filename) {
  $fp = fopen($filename, "wb"); 
  fwrite($fp, $strContent);
  fclose($fp);
  return True;
}

//
// 0. write UTF-8 string in fly into UTF-8 file:
//
$strContent = "My string contains UTF-8 chars ie ???? for un été en France";

$filename = "utf8text.txt";

entSaveAsUtf8($strContent, $filename);


//
// 2. convert CP936 ANSI/OEM - chinese simplified GBK file into UTF-8 file:
//
$strContent = file_get_contents("cp936gbktext.txt");
$strContent = mb_convert_encoding($strContent, "UTF-8", "CP936");


$filename = "utf8text2.txt";

entSaveAsUtf8($strContent, $filename);

?>

The source file cp936gbktext.txt file content:

>>Get-Content cp936gbktext.txt
My string contains UTF-8 chars ie ???? for un été en France 936 (ANSI/OEM - chinois simplifié GBK)

Running utf8save.php on Windows 10 PHP, thus created utf8text.txt, utf8text2.txt files will be automatically saved in UTF-8 format.

With this method, BOM char is not required. BOM solution is bad because it causes troubles when we do sourcing an sql file for MySQL for example.

It's worth noting that I failed making work file_put_contents($filename, utf8_encode($mystring)); for this purpose.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

If you don't know the encoding of the source file, you can list encodings with PHP:

print_r(mb_list_encodings());

This gives a list like this:

Array
(
  [0] => pass
  [1] => wchar
  [2] => byte2be
  [3] => byte2le
  [4] => byte4be
  [5] => byte4le
  [6] => BASE64
  [7] => UUENCODE
  [8] => HTML-ENTITIES
  [9] => Quoted-Printable
  [10] => 7bit
  [11] => 8bit
  [12] => UCS-4
  [13] => UCS-4BE
  [14] => UCS-4LE
  [15] => UCS-2
  [16] => UCS-2BE
  [17] => UCS-2LE
  [18] => UTF-32
  [19] => UTF-32BE
  [20] => UTF-32LE
  [21] => UTF-16
  [22] => UTF-16BE
  [23] => UTF-16LE
  [24] => UTF-8
  [25] => UTF-7
  [26] => UTF7-IMAP
  [27] => ASCII
  [28] => EUC-JP
  [29] => SJIS
  [30] => eucJP-win
  [31] => EUC-JP-2004
  [32] => SJIS-win
  [33] => SJIS-Mobile#DOCOMO
  [34] => SJIS-Mobile#KDDI
  [35] => SJIS-Mobile#SOFTBANK
  [36] => SJIS-mac
  [37] => SJIS-2004
  [38] => UTF-8-Mobile#DOCOMO
  [39] => UTF-8-Mobile#KDDI-A
  [40] => UTF-8-Mobile#KDDI-B
  [41] => UTF-8-Mobile#SOFTBANK
  [42] => CP932
  [43] => CP51932
  [44] => JIS
  [45] => ISO-2022-JP
  [46] => ISO-2022-JP-MS
  [47] => GB18030
  [48] => Windows-1252
  [49] => Windows-1254
  [50] => ISO-8859-1
  [51] => ISO-8859-2
  [52] => ISO-8859-3
  [53] => ISO-8859-4
  [54] => ISO-8859-5
  [55] => ISO-8859-6
  [56] => ISO-8859-7
  [57] => ISO-8859-8
  [58] => ISO-8859-9
  [59] => ISO-8859-10
  [60] => ISO-8859-13
  [61] => ISO-8859-14
  [62] => ISO-8859-15
  [63] => ISO-8859-16
  [64] => EUC-CN
  [65] => CP936
  [66] => HZ
  [67] => EUC-TW
  [68] => BIG-5
  [69] => CP950
  [70] => EUC-KR
  [71] => UHC
  [72] => ISO-2022-KR
  [73] => Windows-1251
  [74] => CP866
  [75] => KOI8-R
  [76] => KOI8-U
  [77] => ArmSCII-8
  [78] => CP850
  [79] => JIS-ms
  [80] => ISO-2022-JP-2004
  [81] => ISO-2022-JP-MOBILE#KDDI
  [82] => CP50220
  [83] => CP50220raw
  [84] => CP50221
  [85] => CP50222
)

If you cannot guess, you try one by one, as mb_detect_encoding() cannot do the job easily.

How to pass extra variables in URL with WordPress

One issue you might run into is is_home() returns true when a registered query_var is present in the home URL. For example, if http://example.com displays a static page instead of the blog, http://example.com/?c=123 will return the blog.

See https://core.trac.wordpress.org/ticket/25143 and https://wordpress.org/support/topic/adding-query-var-makes-front-page-missing/ for more info on this.

What you can do (if you're not attempting to affect the query) is use add_rewrite_endpoint(). It should be run during the init action as it affects the rewrite rules. Eg.

add_action( 'init', 'add_custom_setcookie_rewrite_endpoints' );

function add_custom_setcookie_rewrite_endpoints() {
    //add ?c=123 endpoint with
    //EP_ALL so endpoint is present across all places
    //no effect on the query vars
    add_rewrite_endpoint( 'c', EP_ALL, $query_vars = false );
}

This should give you access to $_GET['c'] when the url contains more information like www.example.com/news?c=123.

Remember to flush your rewrite rules after adding/modifying this.

Reverse for '*' with arguments '()' and keyword arguments '{}' not found

Shell calls to reverse (as mentioned above) are very good to debug these problems, but there are two critical conditions:

  • you must supply arguments that matches whatever arguments the view needs,
  • these arguments must match regexp patterns.

Yes, it's logical. Yes, it's also confusing because reverse will only throw the exception and won't give you any further hints.

An example of URL pattern:

url(r'^cookies/(?P<hostname>[^/]+)/(?P<url_id>\d+)/$', 'register_site.views.show_cookies', name='show_cookies'),

And then what happens in shell:

>>> from register_site.views import show_cookies
>>> reverse(show_cookies)
NoReverseMatch: Reverse for 'register_site.views.show_cookies' with arguments '()' and keyword arguments '{}' not found.

It doesn't work because I supplied no arguments.

>>> reverse('show_cookies', kwargs={'url_id':123,'hostname': 'aaa'})
'/cookies/aaa/123'

Now it worked, but...

>>> reverse('show_cookies', kwargs={'url_id':'x','hostname': 'www.dupa.com'})
NoReverseMatch: Reverse for 'show_cookies' with arguments '()' and keyword arguments '{'url_id': 'x', 'hostname': 'www.dupa.com'}' not found.

Now it didn't work because url_id didn't match the regexp (expected numeric, supplied string).

You can use reverse with both positional arguments and keyword arguments. The syntax is:

reverse(viewname, urlconf=None, args=None, kwargs=None, prefix=None, current_app=None)

As it comes to the url template tag, there's funny thing about it. Django documentation gives example of using quoted view name:

{% url 'news.views.year_archive' yearvar %}

So I used it in a similar way in my HTML template:

{% url 'show_cookies' hostname=u.hostname url_id=u.pk %}

But this didn't work for me. But the exception message gave me a hint of what could be wrong - note the double single quotes around view name:

Reverse for ''show_cookies'' with arguments...

It started to work when I removed the quotes:

{% url show_cookies hostname=u.hostname url_id=u.pk %}

And this is confusing.

How to submit an HTML form without redirection

Using this snippet, you can submit the form and avoid redirection. Instead you can pass the success function as argument and do whatever you want.

function submitForm(form, successFn){
    if (form.getAttribute("id") != '' || form.getAttribute("id") != null){
        var id = form.getAttribute("id");
    } else {
        console.log("Form id attribute was not set; the form cannot be serialized");
    }

    $.ajax({
        type: form.method,
        url: form.action,
        data: $(id).serializeArray(),
        dataType: "json",
        success: successFn,
        //error: errorFn(data)
    });
}

And then just do:

var formElement = document.getElementById("yourForm");
submitForm(formElement, function() {
    console.log("Form submitted");
});

Returning Month Name in SQL Server Query

basically this ...

declare @currentdate datetime = getdate()
select left(datename(month,DATEADD(MONTH, -1, GETDATE())),3)
union all
select left(datename(month,(DATEADD(MONTH, -2, GETDATE()))),3)
union all
select left(datename(month,(DATEADD(MONTH, -3, GETDATE()))),3)

What is Linux’s native GUI API?

Strictly speaking, the API of Linux consists of its system calls. These are all of the kernel functions that can be called by a user-mode (non-kernel) program. This is a very low-level interface that allows programs to do things like open and read files. See http://en.wikipedia.org/wiki/System_call for a general introduction.

A real Linux system will also have an entire "stack" of other software running on it, in order to provide a graphical user interface and other features. Each element of this stack will offer its own API.

How do I find which program is using port 80 in Windows?

Use this nifty freeware utility:

CurrPorts is network monitoring software that displays the list of all currently opened TCP/IP and UDP ports on your local computer.

Enter image description here

Accessing the last entry in a Map

A SortedMap is the logical/best choice, however another option is to use a LinkedHashMap which maintains two order modes, most-recently-added goes last, and most-recently-accessed goes last. See the Javadocs for more details.

How to check if a variable is NULL, then set it with a MySQL stored procedure?

@last_run_time is a 9.4. User-Defined Variables and last_run_time datetime one 13.6.4.1. Local Variable DECLARE Syntax, are different variables.

Try: SELECT last_run_time;

UPDATE

Example:

/* CODE FOR DEMONSTRATION PURPOSES */
DELIMITER $$

CREATE PROCEDURE `sp_test`()
BEGIN
    DECLARE current_procedure_name CHAR(60) DEFAULT 'accounts_general';
    DECLARE last_run_time DATETIME DEFAULT NULL;
    DECLARE current_run_time DATETIME DEFAULT NOW();

    -- Define the last run time
    SET last_run_time := (SELECT MAX(runtime) FROM dynamo.runtimes WHERE procedure_name = current_procedure_name);

    -- if there is no last run time found then use yesterday as starting point
    IF(last_run_time IS NULL) THEN
        SET last_run_time := DATE_SUB(NOW(), INTERVAL 1 DAY);
    END IF;

    SELECT last_run_time;

    -- Insert variables in table2
    INSERT INTO table2 (col0, col1, col2) VALUES (current_procedure_name, last_run_time, current_run_time);
END$$

DELIMITER ;

redirect to current page in ASP.Net

http://en.wikipedia.org/wiki/Post/Redirect/Get

The most common way to implement this pattern in ASP.Net is to use Response.Redirect(Request.RawUrl)

Consider the differences between Redirect and Transfer. Transfer really isn't telling the browser to forward to a clear form, it's simply returning a cleared form. That may or may not be what you want.

Response.Redirect() does not a waste round trip. If you post to a script that clears the form by Server.Transfer() and reload you will be asked to repost by most browsers since the last action was a HTTP POST. This may cause your users to unintentionally repeat some action, eg. place a second order which will have to be voided later.

fatal: early EOF fatal: index-pack failed

finally solved by git config --global core.compression 9

From a BitBucket issue thread:

I tried almost five times, and it still happen.

Then I tried to use better compression and it worked!

git config --global core.compression 9

From the Git Documentation:

core.compression
An integer -1..9, indicating a default compression level. -1 is the zlib default.
0 means no compression, and 1..9 are various speed/size tradeoffs, 9 being slowest.
If set, this provides a default to other compression variables, such as core.looseCompression and pack.compression.

How to delete session cookie in Postman?

into Chrome, right click -> Inspect Element. Go to the tab active tracking of resources and if you have not already. Now the left hand sidebar thingy down until you see "Cookies", click below your domain name and to remove a cookie just right-click on it and "Delete"

TypeScript typed array usage

You could try either of these. They are not giving me errors.

It is also the suggested method from typescript for array declaration.

By using the Array<Thing> it is making use of the generics in typescript. It is similar to asking for a List<T> in c# code. 

// Declare with default value
private _possessions: Array<Thing> = new Array<Thing>();
// or
private _possessions: Array<Thing> = [];
// or -> prefered by ts-lint
private _possessions: Thing[] = [];

or

// declare
private _possessions: Array<Thing>;
// or -> preferd by ts-lint
private _possessions: Thing[];

constructor(){
    //assign
    this._possessions = new Array<Thing>();
    //or
    this._possessions = [];
}

Firefox "ssl_error_no_cypher_overlap" error

I had similar issues browsing to secure sites (https://) when using Burp (or at least an issue that would bring you to this page when searching Google):

  • ssl_error_no_cypher_overlap in Firefox
  • ERR_SSL_VERSION_OR_CIPHER_MISMATCH in Chrome

It turned out to be an issue with using Java 8. When I switched to Java 7, the problem stopped.

How to define an enum with string value?

A class that emulates enum behaviour but using string instead of int can be created as follows...

public class GrainType
{
    private string _typeKeyWord;

    private GrainType(string typeKeyWord)
    {
        _typeKeyWord = typeKeyWord;
    }

    public override string ToString()
    {
        return _typeKeyWord;
    }

    public static GrainType Wheat = new GrainType("GT_WHEAT");
    public static GrainType Corn = new GrainType("GT_CORN");
    public static GrainType Rice = new GrainType("GT_RICE");
    public static GrainType Barley = new GrainType("GT_BARLEY");

}

Usage...

GrainType myGrain = GrainType.Wheat;

PrintGrainKeyword(myGrain);

then...

public void PrintGrainKeyword(GrainType grain) 
{
    Console.Writeline("My Grain code is " + grain.ToString());   // Displays "My Grain code is GT_WHEAT"
}

How to set shadows in React Native for android?

The elevation style property on Android does not work unless backgroundColor has been specified for the element.

Android - elevation style property does not work without backgroundColor

Example: 

{
  shadowColor: 'black',
  shadowOpacity: 0.26,
  shadowOffset: { width: 0, height: 2},
  shadowRadius: 10,
  elevation: 3,
  backgroundColor: 'white'
}

Convert URL to File or Blob for FileReader.readAsDataURL

The suggested edit queue is full for @tibor-udvari's excellent fetch answer, so I'll post my suggested edits as a new answer.

This function gets the content type from the header if returned, otherwise falls back on a settable default type.

async function getFileFromUrl(url, name, defaultType = 'image/jpeg'){
  const response = await fetch(url);
  const data = await response.blob();
  return new File([data], name, {
    type: response.headers.get('content-type') || defaultType,
  });
}

// `await` can only be used in an async body, but showing it here for simplicity.
const file = await getFileFromUrl('https://example.com/image.jpg', 'example.jpg');

How do I check if a number is a palindrome?

Above most of the answers having a trivial problem is that the int variable possibly might overflow.

Refer to http://articles.leetcode.com/palindrome-number/

boolean isPalindrome(int x) {
    if (x < 0)
        return false;
    int div = 1;
    while (x / div >= 10) {
        div *= 10;
    }
    while (x != 0) {
        int l = x / div;
        int r = x % 10;
        if (l != r)
            return false;
        x = (x % div) / 10;
        div /= 100;
    }
    return true;
}

Difference between ApiController and Controller in ASP.NET MVC

Every method in Web API will return data (JSON) without serialization.

However, in order to return JSON Data in MVC controllers, we will set the returned Action Result type to JsonResult and call the Json method on our object to ensure it is packaged in JSON.

Correct way to handle conditional styling in React

I came across this question while trying to answer the same question. McCrohan's approach with the classes array & join is solid.

Through my experience, I have been working with a lot of legacy ruby code that is being converted to React and as we build the component(s) up I find myself reaching out for both existing css classes and inline styles.

example snippet inside a component: 

// if failed, progress bar is red, otherwise green 
<div
    className={`progress-bar ${failed ? failed' : ''}`}
    style={{ width: this.getPercentage() }} 
/>

Again, I find myself reaching out to legacy css code, "packaging" it with the component and moving on.

So, I really feel that it is a bit in the air as to what is "best" as that label will vary greatly depending on your project.

Difference between text and varchar (character varying)

As "Character Types" in the documentation points out, varchar(n), char(n), and text are all stored the same way. The only difference is extra cycles are needed to check the length, if one is given, and the extra space and time required if padding is needed for char(n).

However, when you only need to store a single character, there is a slight performance advantage to using the special type "char" (keep the double-quotes — they're part of the type name). You get faster access to the field, and there is no overhead to store the length.

I just made a table of 1,000,000 random "char" chosen from the lower-case alphabet. A query to get a frequency distribution (select count(*), field ... group by field) takes about 650 milliseconds, vs about 760 on the same data using a text field.

convert a list of objects from one type to another using lambda expression

Or with a constructor & linq with Select:

public class TargetType {
  public string Prop1 {get;set;}
  public string Prop1 {get;set;}

  // Constructor
  public TargetType(OrigType origType) {
    Prop1 = origType.Prop1;
    Prop2 = origType.Prop2;
  }
}

var origList = new List<OrigType>();
var targetList = origList.Select(s=> new TargetType(s)).ToList();

The Linq line is more soft! ;-)

Generating random number between 1 and 10 in Bash Shell Script

Simplest solution would be to use tool which allows you to directly specify ranges, like shuf

shuf -i1-10 -n1

If you want to use $RANDOM, it would be more precise to throw out the last 8 numbers in 0...32767, and just treat it as 0...32759, since taking 0...32767 mod 10 you get the following distribution

0-8 each: 3277 
8-9 each: 3276

So, slightly slower but more precise would be

while :; do ran=$RANDOM; ((ran < 32760)) && echo $(((ran%10)+1)) && break; done

Why would one mark local variables and method parameters as "final" in Java?

Because of the (occasionally) confusing nature of Java's "pass by reference" behavior I definitely agree with finalizing parameter var's.

Finalizing local var's seems somewhat overkill IMO.

PHP & MySQL: mysqli_num_rows() expects parameter 1 to be mysqli_result, boolean given

$dbc is returning false. Your query has an error in it:

SELECT users.*, profile.* --You do not join with profile anywhere.
                                 FROM users 
                                 INNER JOIN contact_info 
                                 ON contact_info.user_id = users.user_id 
                                 WHERE users.user_id=3");

The fix for this in general has been described by Raveren.

Why am I getting Unknown error in line 1 of pom.xml?

While I cannot reproduce your error (as none of your team mates can either), I have a suggestion, that might help you.

Have you heard of the Byte Order Mark? As it appears on line 1 it is a likely candidate for your troubles. Maybe you changed a setting somewhere that somehow leads to the error. This quote from the Wikipedia article is particularly relevant I think:

BOM use is optional. Its presence interferes with the use of UTF-8 by software that does not expect non-ASCII bytes at the start of a file but that could otherwise handle the text stream.

Font.createFont(..) set color and size (java.awt.Font)

Because font doesn't have color, you need a panel to make a backgound color and give the foreground color for both JLabel (if you use JLabel) and JPanel to make font color, like example below :

JLabel lblusr = new JLabel("User name : ");
lblusr.setForeground(Color.YELLOW);

JPanel usrPanel = new JPanel();
Color maroon = new Color (128, 0, 0);
usrPanel.setBackground(maroon);
usrPanel.setOpaque(true);
usrPanel.setForeground(Color.YELLOW);
usrPanel.add(lblusr);

The background color of label is maroon with yellow font color.

Check If array is null or not in php

you can use 

empty($result)

to check if the main array is empty or not.

But since you have a SimpleXMLElement object, you need to query the object if it is empty or not. See http://www.php.net/manual/en/simplexmlelement.count.php

ex:

if (empty($result) || !isset($result['Tags'])) {
    return false;
}
if ( !($result['Tags'] instanceof SimpleXMLElement)) {
    return false;
}
return ($result['Tags']->count());

Lining up labels with radio buttons in bootstrap

This may work for you, Please try this.

<form>
  <div class="form-inline">
    <div class="controls-row">
      <label class="control-label">Some label</label>
      <label class="radio inline">
        <input type="radio" value="1" />First
      </label>
      <label class="radio inline">
        <input type="radio" value="2" />Second
      </label>
    </div>
  </div>
</form>

What does it mean when Statement.executeUpdate() returns -1?

So 4 years later, Microsoft has open sourced their JDBC driver on Github. I got a notification about this question today, and went and had a look, and I believe I have found the culprit here, mssql-jdbc/src/main/java/com/microsoft/sqlserver/jdbc/SQLServerStatement.java:1713.

Basically, the driver tries to understand what SQL Server sends back if it is not a definite result set. According to the comments, it goes like this:

  1. Check for errors first. (ln 1669)

  2. Not an error. Is it a result set? (ln 1680)

  3. Not an error or a result set. Maybe a result from a T-SQL statement? That is, one of the following:

    • a positive count of the number of rows affected (from INSERT, UPDATE, or DELETE),
    • a zero indicating no rows affected, or the statement was DDL, or
    • a -1 indicating the statement succeeded, but there is no update count information available (translates to Statement.SUCCESS_NO_INFO in batch update count arrays). (ln 1706)

  4. None of the above. Last chance here... Going into the parser above, we know moreResults was initially true. If we come out with moreResults false, the we hit a DONE token (either DONE (FINAL) or DONE (RPC in batch)) that indicates that the batch succeeded overall, but that there is no information on individual statements' update counts. This is similar to the last case above, except that there is no update count. That is: we have a successful result (return true), but we have no other information about it (updateCount = -1). (ln 1693)

  5. Only way to get here (moreResults is still true, but no apparent results of any kind) is if the TDSParser didn't actually parse anything. That is, we are at EOF in the response. In that case, there truly are no more results. We're done. (ln 1717)

(Emphasis mine)

So you guys were right in the end. SQL simply can't tell how many rows are affected, and defaults to -1. :)

How to correctly use Html.ActionLink with ASP.NET MVC 4 Areas

Just to add up my bit:
Remember, you're gonna need to have at least 2 areas in your MVC application to get the routeValues: { area="" } working; otherwise the area value will be used as a query-string parameter and you link will look like this: /?area=

If you don't have at least 2 areas, you can fix this behavior by:
1. editing the default route in RouteConfig.cs like this:

routes.MapRoute(
    name: "Default",
    url: "{controller}/{action}/{id}",
    defaults: new { area = "", controller = "Home", action = "Index", id = UrlParameter.Optional }
);

OR
2. Adding a dummy area to your MVC project.

How to output loop.counter in python jinja template?

Inside of a for-loop block, you can access some special variables including loop.index --but no loop.counter. From the official docs:

Variable    Description
loop.index  The current iteration of the loop. (1 indexed)
loop.index0 The current iteration of the loop. (0 indexed)
loop.revindex   The number of iterations from the end of the loop (1 indexed)
loop.revindex0  The number of iterations from the end of the loop (0 indexed)
loop.first  True if first iteration.
loop.last   True if last iteration.
loop.length The number of items in the sequence.
loop.cycle  A helper function to cycle between a list of sequences. See the explanation below.
loop.depth  Indicates how deep in a recursive loop the rendering currently is. Starts at level 1
loop.depth0 Indicates how deep in a recursive loop the rendering currently is. Starts at level 0
loop.previtem   The item from the previous iteration of the loop. Undefined during the first iteration.
loop.nextitem   The item from the following iteration of the loop. Undefined during the last iteration.
loop.changed(*val)  True if previously called with a different value (or not called at all).

Labeling file upload button

To make a custom "browse button" solution simply try making a hidden browse button, a custom button or element and some Jquery. This way I'm not modifying the actual "browse button" which is dependent on each browser/version. Here's an example.

HTML:

<div id="import" type="file">My Custom Button</div>
<input id="browser" class="hideMe" type="file"></input>

CSS:

#import {
  margin: 0em 0em 0em .2em;
  content: 'Import Settings';
  display: inline-block;
  border: 1px solid;
  border-color: #ddd #bbb #999;
  border-radius: 3px;
  padding: 5px 8px;
  outline: none;
  white-space: nowrap;
  -webkit-user-select: none;
  cursor: pointer;
  font-weight: 700;
  font: bold 12px/1.2 Arial,sans-serif !important;
  /* fallback */
  background-color: #f9f9f9;
  /* Safari 4-5, Chrome 1-9 */
  background: -webkit-gradient(linear, 0% 0%, 0% 100%, from(#C2C1C1), to(#2F2727));
}

.hideMe{
    display: none;
}

JS:

$("#import").click(function() {
    $("#browser").trigger("click");
    $('#browser').change(function() {
            alert($("#browser").val());
    });
});

make div's height expand with its content

Very simple way

On parent DIV:

height: 100%;

This work for me every time

Can I perform a DNS lookup (hostname to IP address) using client-side Javascript?

Doing this would require to break the browser sandbox. Try to let your server do the lookup and request that from the client side via XmlHttp.

Jquery: Checking to see if div contains text, then action

Why not simply

var item = $('.field-item');
for (var i = 0; i <= item.length; i++) {
       if ($(item[i]).text() == 'someText') {
             $(item[i]).addClass('thisClass');
             //do some other stuff here
          }
     }

Android: Center an image

In LinearLayout, use: android:layout_gravity="center".

In RelativeLayout, use: android:layout_centerInParent="true".

Align the form to the center in Bootstrap 4

All above answers perfectly gives the solution to center the form using Bootstrap 4. However, if someone wants to use out of the box Bootstrap 4 css classes without help of any additional styles and also not wanting to use flex, we can do like this.

A sample form

enter image description here

HTML

<div class="container-fluid h-100 bg-light text-dark">
  <div class="row justify-content-center align-items-center">
    <h1>Form</h1>    
  </div>
  <hr/>
  <div class="row justify-content-center align-items-center h-100">
    <div class="col col-sm-6 col-md-6 col-lg-4 col-xl-3">
      <form action="">
        <div class="form-group">
          <select class="form-control">
                    <option>Option 1</option>
                    <option>Option 2</option>
                  </select>
        </div>
        <div class="form-group">
          <input type="text" class="form-control" />
        </div>
        <div class="form-group text-center">
          <div class="form-check-inline">
            <label class="form-check-label">
    <input type="radio" class="form-check-input" name="optradio">Option 1
  </label>
          </div>
          <div class="form-check-inline">
            <label class="form-check-label">
    <input type="radio" class="form-check-input" name="optradio">Option 2
  </label>
          </div>
          <div class="form-check-inline">
            <label class="form-check-label">
    <input type="radio" class="form-check-input" name="optradio" disabled>Option 3
  </label>
          </div>
        </div>
        <div class="form-group">
          <div class="container">
            <div class="row">
              <div class="col"><button class="col-6 btn btn-secondary btn-sm float-left">Reset</button></div>
              <div class="col"><button class="col-6 btn btn-primary btn-sm float-right">Submit</button></div>
            </div>
          </div>
        </div>

      </form>
    </div>
  </div>
</div>

Link to CodePen

https://codepen.io/anjanasilva/pen/WgLaGZ

I hope this helps someone. Thank you.

CodeIgniter - accessing $config variable in view

You can do something like that:

$ci = get_instance(); // CI_Loader instance
$ci->load->config('email');
echo $ci->config->item('name');

how to transfer a file through SFTP in java?

Try this code.

public void send (String fileName) {
    String SFTPHOST = "host:IP";
    int SFTPPORT = 22;
    String SFTPUSER = "username";
    String SFTPPASS = "password";
    String SFTPWORKINGDIR = "file/to/transfer";

    Session session = null;
    Channel channel = null;
    ChannelSftp channelSftp = null;
    System.out.println("preparing the host information for sftp.");

    try {
        JSch jsch = new JSch();
        session = jsch.getSession(SFTPUSER, SFTPHOST, SFTPPORT);
        session.setPassword(SFTPPASS);
        java.util.Properties config = new java.util.Properties();
        config.put("StrictHostKeyChecking", "no");
        session.setConfig(config);
        session.connect();
        System.out.println("Host connected.");
        channel = session.openChannel("sftp");
        channel.connect();
        System.out.println("sftp channel opened and connected.");
        channelSftp = (ChannelSftp) channel;
        channelSftp.cd(SFTPWORKINGDIR);
        File f = new File(fileName);
        channelSftp.put(new FileInputStream(f), f.getName());
        log.info("File transfered successfully to host.");
    } catch (Exception ex) {
        System.out.println("Exception found while tranfer the response.");
    } finally {
        channelSftp.exit();
        System.out.println("sftp Channel exited.");
        channel.disconnect();
        System.out.println("Channel disconnected.");
        session.disconnect();
        System.out.println("Host Session disconnected.");
    }
}

Mix Razor and Javascript code

you can use the <text> tag for both cshtml code with javascript

Find a pair of elements from an array whose sum equals a given number

Python Implementation: 

import itertools
list = [1, 1, 2, 3, 4, 5,]
uniquelist = set(list)
targetsum = 5
for n in itertools.combinations(uniquelist, 2):
    if n[0] + n[1] == targetsum:
        print str(n[0]) + " + " + str(n[1])

Output:

1 + 4
2 + 3

Removing border from table cells

Just collapse the table borders and remove the borders from table cells (td elements).

table {
    border: 1px solid #CCC;
    border-collapse: collapse;
}

td {
    border: none;
}

Without explicitly setting border-collapse cross-browser removal of table cell borders is not guaranteed.

Show two digits after decimal point in c++

Using header file stdio.h you can easily do it as usual like c. before using %.2lf(set a specific number after % specifier.) using printf().

It simply printf specific digits after decimal point.

#include <stdio.h>
#include <iostream>
using namespace std;
int main()
{
   double total=100;
   printf("%.2lf",total);//this prints 100.00 like as C
}

How to randomly pick an element from an array

With Java 7, one can use ThreadLocalRandom.

A random number generator isolated to the current thread. Like the global Random generator used by the Math class, a ThreadLocalRandom is initialized with an internally generated seed that may not otherwise be modified. When applicable, use of ThreadLocalRandom rather than shared Random objects in concurrent programs will typically encounter much less overhead and contention. Use of ThreadLocalRandom is particularly appropriate when multiple tasks (for example, each a ForkJoinTask) use random numbers in parallel in thread pools.

public static int getRandomElement(int[] arr){
    return arr[ThreadLocalRandom.current().nextInt(arr.length)];
}

//Example Usage:
int[] nums = {1, 2, 3, 4};
int randNum = getRandomElement(nums);
System.out.println(randNum);

A generic version can also be written, but it will not work for primitive arrays.

public static <T> T getRandomElement(T[] arr){
   return arr[ThreadLocalRandom.current().nextInt(arr.length)];
}

//Example Usage:
String[] strs = {"aa", "bb", "cc"};
String randStr = getRandomElement(strs);
System.out.println(randStr);

Should I use px or rem value units in my CSS?

josh3736's answer is a good one, but to provide a counterpoint 3 years later:

I recommend using rem units for fonts, if only because it makes it easier for you, the developer, to change sizes. It's true that users very rarely change the default font size in their browsers, and that modern browser zoom will scale up px units. But what if your boss comes to you and says "don't enlarge the images or icons, but make all the fonts bigger". It's much easier to just change the root font size and let all the other fonts scale relative to that, then to change px sizes in dozens or hundreds of css rules.

I think it still makes sense to use px units for some images, or for certain layout elements that should always be the same size regardless of the scale of the design.

Caniuse.com may have said that only 75% of browsers when josh3736 posted his answer in 2012, but as of March 27 they claim 93.78% support. Only IE8 doesn't support it among the browsers they track.

How to use CMAKE_INSTALL_PREFIX

But do remember to place it BEFORE PROJECT(< project_name>) command, otherwise it will not work!

My first week of using cmake - after some years of GNU autotools - so I am still learning (better then writing m4 macros), but I think modifying CMAKE_INSTALL_PREFIX after setting project is the better place.

CMakeLists.txt

cmake_minimum_required (VERSION 2.8)

set (CMAKE_INSTALL_PREFIX /foo/bar/bubba)
message("CIP = ${CMAKE_INSTALL_PREFIX} (should be /foo/bar/bubba")
project (BarkBark)
message("CIP = ${CMAKE_INSTALL_PREFIX} (should be /foo/bar/bubba")
set (CMAKE_INSTALL_PREFIX /foo/bar/bubba)
message("CIP = ${CMAKE_INSTALL_PREFIX} (should be /foo/bar/bubba")

First run (no cache)

CIP = /foo/bar/bubba (should be /foo/bar/bubba
-- The C compiler identification is GNU 4.4.7
-- etc, etc,...
CIP = /usr/local (should be /foo/bar/bubba
CIP = /foo/bar/bubba (should be /foo/bar/bubba
-- Configuring done
-- Generating done

Second run

CIP = /foo/bar/bubba (should be /foo/bar/bubba
CIP = /foo/bar/bubba (should be /foo/bar/bubba
CIP = /foo/bar/bubba (should be /foo/bar/bubba
-- Configuring done
-- Generating done

Let me know if I am mistaken, I have a lot of learning to do. It's fun.

How to force child div to be 100% of parent div's height without specifying parent's height?

using jQuery:

$(function() {
    function unifyHeights() {
        var maxHeight = 0;
        $('#container').children('#navigation, #content').each(function() {
            var height = $(this).outerHeight();
            // alert(height);
            if ( height > maxHeight ) {
                maxHeight = height;
            }
        });
        $('#navigation, #content').css('height', maxHeight);
    }
    unifyHeights();
});

How can I select all children of an element except the last child?

Nick Craver's solution works but you can also use this:

:nth-last-child(n+2) { /* Your code here */ }

Chris Coyier of CSS Tricks made a nice :nth tester for this.

How do I handle too long index names in a Ruby on Rails ActiveRecord migration?

I'm afraid none of these solutions worked for me. Perhaps because I was using belongs_to in my create_table migration for a polymorphic association.

I'll add my code below and a link to the solution that helped me in case anyone else stumbles upon when searching for 'Index name is too long' in connection with polymorphic associations.

The following code did NOT work for me:

def change
  create_table :item_references do |t|
    t.text :item_unique_id
    t.belongs_to :referenceable, polymorphic: true
    t.timestamps
  end
  add_index :item_references, [:referenceable_id, :referenceable_type], name: 'idx_item_refs'
end

This code DID work for me:

def change
  create_table :item_references do |t|
    t.text :item_unique_id
    t.belongs_to :referenceable, polymorphic: true, index: { name: 'idx_item_refs' }

    t.timestamps
  end
end

This is the SO Q&A that helped me out: https://stackoverflow.com/a/30366460/3258059

Specify JDK for Maven to use

Yet another alternative to manage multiple jdk versions is jEnv

After installation, you can simply change java version "locally" i.e. for a specific project directory by:

jenv local 1.6

This will also make mvn use that version locally, when you enable the mvn plugin:

jenv enable-plugin maven

How to change the icon of an Android app in Eclipse?

Icon creation wizard

  • Select your project
  • Ctrl+n
  • Android Icon Set

WebDriverException: unknown error: DevToolsActivePort file doesn't exist while trying to initiate Chrome Browser

In my case it happened when I've tried to use my default user profile:

...
options.addArguments("user-data-dir=D:\\MyHomeDirectory\\Google\\Chrome\\User Data");
...

This triggered chrome to reuse processes already running in background, in such a way, that process started by chromedriver.exe was simply ended.

Resolution: kill all chrome.exe processes running in background.

How to grant remote access permissions to mysql server for user?

By mysql 8 and later version, you cannot add a user by granting privileges. it means with this query:

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' 
    IDENTIFIED BY 'type-root-password-here' 
    WITH GRANT OPTION;
FLUSH PRIVILEGES;

mysql will return this error:

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'IDENTIFIED BY 'written password' at line 1

this means you don't have a root user for % domain. so you need to first insert the user and then grant privileges like this:

mysql> CREATE USER 'root'@'%' IDENTIFIED BY 'your password';
Query OK, 0 rows affected (0.11 sec)

mysql> GRANT ALL ON *.* TO 'root'@'%';
Query OK, 0 rows affected (0.15 sec)

mysql> FLUSH PRIVILEGES;

Dont forget to replace passwords with your specific passwords.

How to get a reversed list view on a list in Java?

I use this:

public class ReversedView<E> extends AbstractList<E>{

    public static <E> List<E> of(List<E> list) {
        return new ReversedView<>(list);
    }

    private final List<E> backingList;

    private ReversedView(List<E> backingList){
        this.backingList = backingList;
    }

    @Override
    public E get(int i) {
        return backingList.get(backingList.size()-i-1);
    }

    @Override
    public int size() {
        return backingList.size();
    }

}

like this:

ReversedView.of(backingList) // is a fully-fledged generic (but read-only) list

plot a circle with pyplot

 
#!/usr/bin/python
import matplotlib.pyplot as plt
import numpy as np

def xy(r,phi):
  return r*np.cos(phi), r*np.sin(phi)

fig = plt.figure()
ax = fig.add_subplot(111,aspect='equal')  

phis=np.arange(0,6.28,0.01)
r =1.
ax.plot( *xy(r,phis), c='r',ls='-' )
plt.show()

Or, if you prefer, look at the paths, http://matplotlib.sourceforge.net/users/path_tutorial.html

Color text in terminal applications in UNIX

Different solution that I find more elegant

Here's another way to do it. Some people will prefer this as the code is a bit cleaner. There are no %s and a RESET color to end the coloration.

#include <stdio.h>

#define RED   "\x1B[31m"
#define GRN   "\x1B[32m"
#define YEL   "\x1B[33m"
#define BLU   "\x1B[34m"
#define MAG   "\x1B[35m"
#define CYN   "\x1B[36m"
#define WHT   "\x1B[37m"
#define RESET "\x1B[0m"

int main() {
  printf(RED "red\n"     RESET);
  printf(GRN "green\n"   RESET);
  printf(YEL "yellow\n"  RESET);
  printf(BLU "blue\n"    RESET);
  printf(MAG "magenta\n" RESET);
  printf(CYN "cyan\n"    RESET);
  printf(WHT "white\n"   RESET);

  return 0;
}

This program gives the following output:

enter image description here

Simple example with multiple colors

This way, it's easy to do something like:

printf("This is " RED "red" RESET " and this is " BLU "blue" RESET "\n");

This line produces the following output:

execution's output

Using curl POST with variables defined in bash script functions

You don't need to pass the quotes enclosing the custom headers to curl. Also, your variables in the middle of the data argument should be quoted.

First, write a function that generates the post data of your script. This saves you from all sort of headaches concerning shell quoting and makes it easier to read an maintain the script than feeding the post data on curl's invocation line as in your attempt:

generate_post_data()
{
  cat <<EOF
{
  "account": {
    "email": "$email",
    "screenName": "$screenName",
    "type": "$theType",
    "passwordSettings": {
      "password": "$password",
      "passwordConfirm": "$password"
    }
  },
  "firstName": "$firstName",
  "lastName": "$lastName",
  "middleName": "$middleName",
  "locale": "$locale",
  "registrationSiteId": "$registrationSiteId",
  "receiveEmail": "$receiveEmail",
  "dateOfBirth": "$dob",
  "mobileNumber": "$mobileNumber",
  "gender": "$gender",
  "fuelActivationDate": "$fuelActivationDate",
  "postalCode": "$postalCode",
  "country": "$country",
  "city": "$city",
  "state": "$state",
  "bio": "$bio",
  "jpFirstNameKana": "$jpFirstNameKana",
  "jpLastNameKana": "$jpLastNameKana",
  "height": "$height",
  "weight": "$weight",
  "distanceUnit": "MILES",
  "weightUnit": "POUNDS",
  "heightUnit": "FT/INCHES"
}
EOF
}

It is then easy to use that function in the invocation of curl:

curl -i \
-H "Accept: application/json" \
-H "Content-Type:application/json" \
-X POST --data "$(generate_post_data)" "https://xxx:[email protected]/xxxxx/xxxx/xxxx"

This said, here are a few clarifications about shell quoting rules:

The double quotes in the -H arguments (as in -H "foo bar") tell bash to keep what's inside as a single argument (even if it contains spaces).

The single quotes in the --data argument (as in --data 'foo bar') do the same, except they pass all text verbatim (including double quote characters and the dollar sign).

To insert a variable in the middle of a single quoted text, you have to end the single quote, then concatenate with the double quoted variable, and re-open the single quote to continue the text: 'foo bar'"$variable"'more foo'.

event Action<> vs event EventHandler<>

I realize that this question is over 10 years old, but it appears to me that not only has the most obvious answer not been addressed, but that maybe its not really clear from the question a good understanding of what goes on under the covers. In addition, there are other questions about late binding and what that means with regards to delegates and lambdas (more on that later).

First to address the 800 lb elephant/gorilla in the room, when to choose event vs Action<T>/Func<T>:

  • Use a lambda to execute one statement or method. Use event when you want more of a pub/sub model with multiple statements/lambdas/functions that will execute (this is a major difference right off the bat).
  • Use a lambda when you want to compile statements/functions to expression trees. Use delegates/events when you want to participate in more traditional late binding such as used in reflection and COM interop.

As an example of an event, lets wire up a simple and 'standard' set of events using a small console application as follows:

public delegate void FireEvent(int num);

public delegate void FireNiceEvent(object sender, SomeStandardArgs args);

public class SomeStandardArgs : EventArgs
{
    public SomeStandardArgs(string id)
    {
        ID = id;
    }

    public string ID { get; set; }
}

class Program
{
    public static event FireEvent OnFireEvent;

    public static event FireNiceEvent OnFireNiceEvent;


    static void Main(string[] args)
    {
        OnFireEvent += SomeSimpleEvent1;
        OnFireEvent += SomeSimpleEvent2;

        OnFireNiceEvent += SomeStandardEvent1;
        OnFireNiceEvent += SomeStandardEvent2;


        Console.WriteLine("Firing events.....");
        OnFireEvent?.Invoke(3);
        OnFireNiceEvent?.Invoke(null, new SomeStandardArgs("Fred"));

        //Console.WriteLine($"{HeightSensorTypes.Keyence_IL030}:{(int)HeightSensorTypes.Keyence_IL030}");
        Console.ReadLine();
    }

    private static void SomeSimpleEvent1(int num)
    {
        Console.WriteLine($"{nameof(SomeSimpleEvent1)}:{num}");
    }
    private static void SomeSimpleEvent2(int num)
    {
        Console.WriteLine($"{nameof(SomeSimpleEvent2)}:{num}");
    }

    private static void SomeStandardEvent1(object sender, SomeStandardArgs args)
    {

        Console.WriteLine($"{nameof(SomeStandardEvent1)}:{args.ID}");
    }
    private static void SomeStandardEvent2(object sender, SomeStandardArgs args)
    {
        Console.WriteLine($"{nameof(SomeStandardEvent2)}:{args.ID}");
    }
}

The output will look as follows:

enter image description here

If you did the same with Action<int> or Action<object, SomeStandardArgs>, you would only see SomeSimpleEvent2 and SomeStandardEvent2.

So whats going on inside of event?

If we expand out FireNiceEvent, the compiler is actually generating the following (I have omitted some details with respect to thread synchronization that isn't relevant to this discussion):

   private EventHandler<SomeStandardArgs> _OnFireNiceEvent;

    public void add_OnFireNiceEvent(EventHandler<SomeStandardArgs> handler)
    {
        Delegate.Combine(_OnFireNiceEvent, handler);
    }

    public void remove_OnFireNiceEvent(EventHandler<SomeStandardArgs> handler)
    {
        Delegate.Remove(_OnFireNiceEvent, handler);
    }

    public event EventHandler<SomeStandardArgs> OnFireNiceEvent
    {
        add
        {
            add_OnFireNiceEvent(value)
        }
        remove
        {
            remove_OnFireNiceEvent(value)

        }
    }

The compiler generates a private delegate variable which is not visible to the class namespace in which it is generated. That delegate is what is used for subscription management and late binding participation, and the public facing interface is the familiar += and -= operators we have all come to know and love : )

You can customize the code for the add/remove handlers by changing the scope of the FireNiceEvent delegate to protected. This now allows developers to add custom hooks to the hooks, such as logging or security hooks. This really makes for some very powerful features that now allows for customized accessibility to subscription based on user roles, etc. Can you do that with lambdas? (Actually you can by custom compiling expression trees, but that's beyond the scope of this response).

To address a couple of points from some of the responses here:

  • There really is no difference in the 'brittleness' between changing the args list in Action<T> and changing the properties in a class derived from EventArgs. Either will not only require a compile change, they will both change a public interface and will require versioning. No difference.

  • With respect to which is an industry standard, that depends on where this is being used and why. Action<T> and such is often used in IoC and DI, and event is often used in message routing such as GUI and MQ type frameworks. Note that I said often, not always.

  • Delegates have different lifetimes than lambdas. One also has to be aware of capture... not just with closure, but also with the notion of 'look what the cat dragged in'. This does affect memory footprint/lifetime as well as management a.k.a. leaks.

One more thing, something I referenced earlier... the notion of late binding. You will often see this when using framework like LINQ, regarding when a lambda becomes 'live'. That is very different than late binding of a delegate, which can happen more than once (i.e. the lambda is always there, but binding occurs on demand as often as is needed), as opposed to a lambda, which once it occurs, its done -- the magic is gone, and the method(s)/property(ies) will always bind. Something to keep in mind.

Video 100% width and height

You can use Javascript to dynamically set the height to 100% of the window and then center it using a negative left margin based on the ratio of video width to window width.

http://jsfiddle.net/RfV5C/

var $video  = $('video'),
    $window = $(window); 

$(window).resize(function(){
    var height = $window.height();
    $video.css('height', height);

    var videoWidth = $video.width(),
        windowWidth = $window.width(),
    marginLeftAdjust =   (windowWidth - videoWidth) / 2;

    $video.css({
        'height': height, 
        'marginLeft' : marginLeftAdjust
    });
}).resize();

C++ - Assigning null to a std::string

Many C APIs use a null pointer to indicate "use the default", e.g. mosquittopp. Here is the pattern I am using, based on David Cormack's answer:

    mosqpp::tls_set(
        MqttOptions->CAFile.length() > 0 ? MqttOptions->CAFile.c_str() : NULL,
        MqttOptions->CAPath.length() > 0 ? MqttOptions->CAPath.c_str() : NULL,
        MqttOptions->CertFile.length() > 0 ? MqttOptions->CertFile.c_str() : NULL,
        MqttOptions->KeyFile.length() > 0 ? MqttOptions->KeyFile.c_str() : NULL
    );

It is a little cumbersome, but allows one to keep everything as a std::string up until the API call itself.

Read/Write String from/to a File in Android

Kotlin

class FileReadWriteService {

    private var context:Context? = ContextHolder.instance.appContext

    fun writeFileOnInternalStorage(fileKey: String, sBody: String) {
        val file = File(context?.filesDir, "files")
        try {
            if (!file.exists()) {
                file.mkdir()
            }
            val fileToWrite = File(file, fileKey)
            val writer = FileWriter(fileToWrite)
            writer.append(sBody)
            writer.flush()
            writer.close()
        } catch (e: Exception) {
            Logger.e(classTag, e)
        }
    }

    fun readFileOnInternalStorage(fileKey: String): String {
        val file = File(context?.filesDir, "files")
        var ret = ""
        try {
            if (!file.exists()) {
                return ret
            }
            val fileToRead = File(file, fileKey)
            val reader = FileReader(fileToRead)
            ret = reader.readText()
            reader.close()
        } catch (e: Exception) {
            Logger.e(classTag, e)
        }
        return ret
    }
}

How to prevent custom views from losing state across screen orientation changes

Instead of using onSaveInstanceState and onRestoreInstanceState, you can also use a ViewModel. Make your data model extend ViewModel, and then you can use ViewModelProviders to get the same instance of your model every time the Activity is recreated:

class MyData extends ViewModel {
    // have all your properties with getters and setters here
}

public class MyActivity extends FragmentActivity {
    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // the first time, ViewModelProvider will create a new MyData
        // object. When the Activity is recreated (e.g. because the screen
        // is rotated), ViewModelProvider will give you the initial MyData
        // object back, without creating a new one, so all your property
        // values are retained from the previous view.
        myData = ViewModelProviders.of(this).get(MyData.class);

        ...
    }
}

To use ViewModelProviders, add the following to dependencies in app/build.gradle:

implementation "android.arch.lifecycle:extensions:1.1.1"
implementation "android.arch.lifecycle:viewmodel:1.1.1"

Note that your MyActivity extends FragmentActivity instead of just extending Activity.

You can read more about ViewModels here:

pandas: filter rows of DataFrame with operator chaining

I'm not entirely sure what you want, and your last line of code does not help either, but anyway:

"Chained" filtering is done by "chaining" the criteria in the boolean index.

In [96]: df
Out[96]:
   A  B  C  D
a  1  4  9  1
b  4  5  0  2
c  5  5  1  0
d  1  3  9  6

In [99]: df[(df.A == 1) & (df.D == 6)]
Out[99]:
   A  B  C  D
d  1  3  9  6

If you want to chain methods, you can add your own mask method and use that one.

In [90]: def mask(df, key, value):
   ....:     return df[df[key] == value]
   ....:

In [92]: pandas.DataFrame.mask = mask

In [93]: df = pandas.DataFrame(np.random.randint(0, 10, (4,4)), index=list('abcd'), columns=list('ABCD'))

In [95]: df.ix['d','A'] = df.ix['a', 'A']

In [96]: df
Out[96]:
   A  B  C  D
a  1  4  9  1
b  4  5  0  2
c  5  5  1  0
d  1  3  9  6

In [97]: df.mask('A', 1)
Out[97]:
   A  B  C  D
a  1  4  9  1
d  1  3  9  6

In [98]: df.mask('A', 1).mask('D', 6)
Out[98]:
   A  B  C  D
d  1  3  9  6

Check if a string is null or empty in XSLT

I know this question is old, but between all the answers, I miss one that is a common approach for this use-case in XSLT development.

I am imagining that the missing code from the OP looks something like this:

<xsl:template match="category">
    <xsl:choose>
        <xsl:when test="categoryName !=null">
            <xsl:value-of select="categoryName " />
        </xsl:when>
        <xsl:otherwise>
            <xsl:value-of select="other" />
        </xsl:otherwise>
    </xsl:choose>
</category>

And that the input looks something like this:

<categories>
    <category>
       <categoryName>Books</categoryName>
    </category>
    <category>
       <categoryName>Magazines</categoryName>
       <categoryName>Periodicals</categoryName>
       <categoryName>Journals</categoryName>
    </category>
    <category>
        <categoryName><!-- please fill in category --></categoryName>
    </category>
    <category>
        <categoryName />
    </category>
    <category />
</categories>

I.e., I assume there can be zero, empty, single or multiple categoryName elements. To deal with all these cases using xsl:choose-style constructs, or in other words, imperatively, is quickly getting messy (even more so if elements can be at different levels!). A typical programming idiom in XSLT is using templates (hence the T in XSLT), which is declarative programming, not imperative (you don't tell the processor what to do, you just tell what you want output if certain conditions are met). For this use-case, that can look something like the following:

<!-- positive test, any category with a valid categoryName -->
<xsl:template match="category[categoryName[text()]]">
    <xsl:apply-templates />
</xsl:template>

<!-- any other category (without categoryName, "null", with comments etc) -->
<xsl:template match="category">
    <xsl:text>Category: Other</xsl:text>
</xsl:template>

<!-- matching the categoryName itself for easy handling of multiple names -->
<xsl:template match="categoryName">
    <xsl:text>Category: </xsl:text>
    <xsl:value-of select="." />
</xsl:template>

This works (with any XSLT version), because the first one above has a higher precedence (it has a predicate). The "fall-through" matching template, the second one, catches anything that is not valid. The third one then takes care of outputting the categoryName value in a proper way.

Note that in this scenario there is no need to specifially match categories or category, because the processor will automatically process all children, unless we tell it otherwise (in this example, the second and third template do not further process the children, because there is no xsl:apply-templates in them).

This approach is more easily extendible then the imperative approach, because it automically deals with multiple categories and it can be expanded for other elements or exceptions by just adding another matching template. Programming without if-branches.

Note: there is no such thing as null in XML. There is xsi:nil, but that is rarely used, especially rarely in untyped scenarios without a schema of some sort.

What does `unsigned` in MySQL mean and when to use it?

MySQL says:

All integer types can have an optional (nonstandard) attribute UNSIGNED. Unsigned type can be used to permit only nonnegative numbers in a column or when you need a larger upper numeric range for the column. For example, if an INT column is UNSIGNED, the size of the column's range is the same but its endpoints shift from -2147483648 and 2147483647 up to 0 and 4294967295.

When do I use it ?

Ask yourself this question: Will this field ever contain a negative value?
If the answer is no, then you want an UNSIGNED data type.

A common mistake is to use a primary key that is an auto-increment INT starting at zero, yet the type is SIGNED, in that case you’ll never touch any of the negative numbers and you are reducing the range of possible id's to half.

Normalize data in pandas

You can use apply for this, and it's a bit neater:

import numpy as np
import pandas as pd

np.random.seed(1)

df = pd.DataFrame(np.random.randn(4,4)* 4 + 3)

          0         1         2         3
0  9.497381  0.552974  0.887313 -1.291874
1  6.461631 -6.206155  9.979247 -0.044828
2  4.276156  2.002518  8.848432 -5.240563
3  1.710331  1.463783  7.535078 -1.399565

df.apply(lambda x: (x - np.mean(x)) / (np.max(x) - np.min(x)))

          0         1         2         3
0  0.515087  0.133967 -0.651699  0.135175
1  0.125241 -0.689446  0.348301  0.375188
2 -0.155414  0.310554  0.223925 -0.624812
3 -0.484913  0.244924  0.079473  0.114448

Also, it works nicely with groupby, if you select the relevant columns:

df['grp'] = ['A', 'A', 'B', 'B']

          0         1         2         3 grp
0  9.497381  0.552974  0.887313 -1.291874   A
1  6.461631 -6.206155  9.979247 -0.044828   A
2  4.276156  2.002518  8.848432 -5.240563   B
3  1.710331  1.463783  7.535078 -1.399565   B


df.groupby(['grp'])[[0,1,2,3]].apply(lambda x: (x - np.mean(x)) / (np.max(x) - np.min(x)))

     0    1    2    3
0  0.5  0.5 -0.5 -0.5
1 -0.5 -0.5  0.5  0.5
2  0.5  0.5  0.5 -0.5
3 -0.5 -0.5 -0.5  0.5

Waiting for HOME ('android.process.acore') to be launched

I noticed this is an old post. However I just ran into the same problem and found a solution. A) Make sure you have the CPU/ABI is atom B)Ram is 2048 C)VM Heap is 256 D)Internal Storage is 200 E)Make sure to check the Use Host GPU F)Device is Nexus 5 (My personal choice) G)Android 4.4.2 API Level 19