Programs & Examples On #Nhibernate inheritance

Raise an error manually in T-SQL to jump to BEGIN CATCH block

SQL has an error raising mechanism

RAISERROR ( { msg_id | msg_str | @local_variable }
{ ,severity ,state }
[ ,argument [ ,...n ] ] )
[ WITH option [ ,...n ] ]

Just look up Raiserror in the Books Online. But.. you have to generate an error of the appropriate severity, an error at severity 0 thru 10 do not cause you to jump to the catch block.

Can you use a trailing comma in a JSON object?

From my past experience, I found that different browsers deal with trailing commas in JSON differently.

Both Firefox and Chrome handles it just fine. But IE (All versions) seems to break. I mean really break and stop reading the rest of the script.

Keeping that in mind, and also the fact that it's always nice to write compliant code, I suggest spending the extra effort of making sure that there's no trailing comma.

:)

Javascript: Call a function after specific time period

setTimeout(func, 5000);

-- it will call the function named func() after the time specified. here, 5000 milli seconds , i.e) after 5 seconds

Java - Relative path of a file in a java web application

If you have a path for that file in the web server, you can get the real path in the server's file system using ServletContext.getRealPath(). Note that it is not guaranteed to work in every container (as a container is not required to unpack the WAR file and store the content in the file system - most do though). And I guess it won't work with files in /WEB-INF, as they don't have a virtual path.

The alternative would be to use ServletContext.getResource() which returns a URI. This URI may be a 'file:' URL, but there's no guarantee for that.

Count the number of occurrences of a string in a VARCHAR field?

A little bit simpler and more effective variation of @yannis solution:

SELECT 
    title,
    description,    
    CHAR_LENGTH(description) - CHAR_LENGTH( REPLACE ( description, 'value', '1234') ) 
        AS `count`    
FROM <table> 

The difference is that I replace the "value" string with a 1-char shorter string ("1234" in this case). This way you don't need to divide and round to get an integer value.

Generalized version (works for every needle string):

SET @needle = 'value';
SELECT 
    description,    
    CHAR_LENGTH(description) - CHAR_LENGTH(REPLACE(description, @needle, SPACE(LENGTH(@needle)-1))) 
        AS `count`    
FROM <table> 

The intel x86 emulator accelerator (HAXM installer) revision 6.0.5 is showing not compatible with windows

Try the following

  1. download HAXM from Intel https://software.intel.com/en-us/android/articles/intel-hardware-accelerated-execution-manager.

  2. Unzip the file and Run intelhaxm-android.exe.

  3. Run silent_install.bat.

In my computer Win10 x64 - VS2015 it worked

How to remove only 0 (Zero) values from column in excel 2010

(Ctrl+H) -> Find and Replace window opens -> Find what "0" ,Replace with " "(leave it blank )-> click options tick match entire cell contents -> click "Replace All" button .

A JSONObject text must begin with '{' at 1 [character 2 line 1] with '{' error

I had the same error and struggled to fix it, then answer above by Nagaraja JB helped me to fix it. In my case:

Was before: JSONObject response_json = new JSONObject(response_data);

Changed it to: JSONArray response_json = new JSONArray(response_data);

This fixed it.

How to store arrays in MySQL?

The proper way to do this is to use multiple tables and JOIN them in your queries.

For example:

CREATE TABLE person (
`id` INT NOT NULL PRIMARY KEY,
`name` VARCHAR(50)
);

CREATE TABLE fruits (
`fruit_name` VARCHAR(20) NOT NULL PRIMARY KEY,
`color` VARCHAR(20),
`price` INT
);

CREATE TABLE person_fruit (
`person_id` INT NOT NULL,
`fruit_name` VARCHAR(20) NOT NULL,
PRIMARY KEY(`person_id`, `fruit_name`)
);

The person_fruit table contains one row for each fruit a person is associated with and effectively links the person and fruits tables together, I.E.

1 | "banana"
1 | "apple"
1 | "orange"
2 | "straberry"
2 | "banana"
2 | "apple"

When you want to retrieve a person and all of their fruit you can do something like this:

SELECT p.*, f.*
FROM person p
INNER JOIN person_fruit pf
ON pf.person_id = p.id
INNER JOIN fruits f
ON f.fruit_name = pf.fruit_name

Convert array of strings into a string in Java

Following is an example of Array to String conversion.

    public class ArrayToString
    {
public static void main(String[] args) { String[] strArray = new String[]{"Java", "PHP", ".NET", "PERL", "C", "COBOL"};

        String newString = Arrays.toString(strArray);

        newString = newString.substring(1, newString.length()-1);

        System.out.println("New New String: " + newString);
    }
}

check if "it's a number" function in Oracle

well, you could create the is_number function to call so your code works.

create or replace function is_number(param varchar2) return boolean
 as
   ret number;
 begin
    ret := to_number(param);
    return true;
 exception
    when others then return false;
 end;

EDIT: Please defer to Justin's answer. Forgot that little detail for a pure SQL call....

Best way to do multi-row insert in Oracle?

This works in Oracle:

insert into pager (PAG_ID,PAG_PARENT,PAG_NAME,PAG_ACTIVE)
          select 8000,0,'Multi 8000',1 from dual
union all select 8001,0,'Multi 8001',1 from dual

The thing to remember here is to use the from dual statement.

AngularJS: How can I pass variables between controllers?

I like to illustrate simple things by simple examples :)

Here is a very simple Service example:


angular.module('toDo',[])

.service('dataService', function() {

  // private variable
  var _dataObj = {};

  // public API
  this.dataObj = _dataObj;
})

.controller('One', function($scope, dataService) {
  $scope.data = dataService.dataObj;
})

.controller('Two', function($scope, dataService) {
  $scope.data = dataService.dataObj;
});

And here the jsbin

And here is a very simple Factory example:


angular.module('toDo',[])

.factory('dataService', function() {

  // private variable
  var _dataObj = {};

  // public API
  return {
    dataObj: _dataObj
  };
})

.controller('One', function($scope, dataService) {
  $scope.data = dataService.dataObj;
})

.controller('Two', function($scope, dataService) {
  $scope.data = dataService.dataObj;
});

And here the jsbin


If that is too simple, here is a more sophisticated example

Also see the answer here for related best practices comments

Linq UNION query to select two elements

EDIT:

Ok I found why the int.ToString() in LINQtoEF fails, please read this post: Problem with converting int to string in Linq to entities

This works on my side :

        List<string> materialTypes = (from u in result.Users
                                      select u.LastName)
                       .Union(from u in result.Users
                               select SqlFunctions.StringConvert((double) u.UserId)).ToList();

On yours it should be like this:

    IList<String> materialTypes = ((from tom in context.MaterialTypes
                                       where tom.IsActive == true
                                       select tom.Name)
                                       .Union(from tom in context.MaterialTypes
                                       where tom.IsActive == true
                                       select SqlFunctions.StringConvert((double)tom.ID))).ToList();

Thanks, i've learnt something today :)

How to view query error in PDO PHP

/* Provoke an error -- the BONES table does not exist */

$sth = $dbh->prepare('SELECT skull FROM bones');
$sth->execute();

echo "\nPDOStatement::errorInfo():\n";
$arr = $sth->errorInfo();
print_r($arr);

output

Array
(
    [0] => 42S02
    [1] => -204
    [2] => [IBM][CLI Driver][DB2/LINUX] SQL0204N  "DANIELS.BONES" is an undefined name.  SQLSTATE=42704
)

Formula to convert date to number

The Excel number for a modern date is most easily calculated as the number of days since 12/30/1899 on the Gregorian calendar.

Excel treats the mythical date 01/00/1900 (i.e., 12/31/1899) as corresponding to 0, and incorrectly treats year 1900 as a leap year. So for dates before 03/01/1900, the Excel number is effectively the number of days after 12/31/1899.

However, Excel will not format any number below 0 (-1 gives you ##########) and so this only matters for "01/00/1900" to 02/28/1900, making it easier to just use the 12/30/1899 date as a base.

A complete function in DB2 SQL that accounts for the leap year 1900 error:

SELECT
   DAYS(INPUT_DATE)                 
   - DAYS(DATE('1899-12-30'))
   - CASE                       
        WHEN INPUT_DATE < DATE('1900-03-01')  
           THEN 1               
           ELSE 0               
     END

Execute script after specific delay using JavaScript

I had some ajax commands I wanted to run with a delay in between. Here is a simple example of one way to do that. I am prepared to be ripped to shreds though for my unconventional approach. :)

//  Show current seconds and milliseconds
//  (I know there are other ways, I was aiming for minimal code
//  and fixed width.)
function secs()
{
    var s = Date.now() + ""; s = s.substr(s.length - 5);
  return s.substr(0, 2) + "." + s.substr(2);
}

//  Log we're loading
console.log("Loading: " + secs());

//  Create a list of commands to execute
var cmds = 
[
    function() { console.log("A: " + secs()); },
    function() { console.log("B: " + secs()); },
    function() { console.log("C: " + secs()); },
    function() { console.log("D: " + secs()); },
    function() { console.log("E: " + secs()); },
  function() { console.log("done: " + secs()); }
];

//  Run each command with a second delay in between
var ms = 1000;
cmds.forEach(function(cmd, i)
{
    setTimeout(cmd, ms * i);
});

// Log we've loaded (probably logged before first command)
console.log("Loaded: " + secs());

You can copy the code block and paste it into a console window and see something like:

Loading: 03.077
Loaded: 03.078
A: 03.079
B: 04.075
C: 05.075
D: 06.075
E: 07.076
done: 08.076

How to use find command to find all files with extensions from list?

In supplement to @Dennis Williamson 's response above, if you want the same regex to be case-insensitive to the file extensions, use -iregex :

find /path/to -iregex ".*\.\(jpg\|gif\|png\|jpeg\)" > log

word-wrap break-word does not work in this example

Use this code (taken from css-tricks) that will work on all browser

overflow-wrap: break-word;
word-wrap: break-word;

-ms-word-break: break-all;
/* This is the dangerous one in WebKit, as it breaks things wherever */
word-break: break-all;
/* Instead use this non-standard one: */
word-break: break-word;

/* Adds a hyphen where the word breaks, if supported (No Blink) */
-ms-hyphens: auto;
-moz-hyphens: auto;
-webkit-hyphens: auto;
hyphens: auto;

Custom CSS for <audio> tag?

There are CSS options for the audio tag.

Like: html 5 audio tag width

But if you play around with it you'll see results can be unexpected - as of August 2012.

Check if a Class Object is subclass of another Class Object in Java

This is an improved version of @schuttek's answer. It is improved because it correctly return false for primitives (e.g. isSubclassOf(int.class, Object.class) => false) and also correctly handles interfaces (e.g. isSubclassOf(HashMap.class, Map.class) => true).

static public boolean isSubclassOf(final Class<?> clazz, final Class<?> possibleSuperClass)
{
    if (clazz == null || possibleSuperClass == null)
    {
        return false;
    }
    else if (clazz.equals(possibleSuperClass))
    {
        return true;
    }
    else
    {
        final boolean isSubclass = isSubclassOf(clazz.getSuperclass(), possibleSuperClass);

        if (!isSubclass && clazz.getInterfaces() != null)
        {
            for (final Class<?> inter : clazz.getInterfaces())
            {
                if (isSubclassOf(inter, possibleSuperClass))
                {
                    return true;
                }
            }
        }

        return isSubclass;
    }
}

This IP, site or mobile application is not authorized to use this API key

You create an key with out referer dont enter the referer address

Why is document.body null in my javascript?

Your script is being executed before the body element has even loaded.

There are a couple ways to workaround this.

  • Wrap your code in a DOM Load callback:

    Wrap your logic in an event listener for DOMContentLoaded.

    In doing so, the callback will be executed when the body element has loaded.

    document.addEventListener('DOMContentLoaded', function () {
        // ...
        // Place code here.
        // ...
    });
    

    Depending on your needs, you can alternatively attach a load event listener to the window object:

    window.addEventListener('load', function () {
        // ...
        // Place code here.
        // ...
    });
    

    For the difference between between the DOMContentLoaded and load events, see this question.

  • Move the position of your <script> element, and load JavaScript last:

    Right now, your <script> element is being loaded in the <head> element of your document. This means that it will be executed before the body has loaded. Google developers recommends moving the <script> tags to the end of your page so that all the HTML content is rendered before the JavaScript is processed.

    <!DOCTYPE html>
    <html>
    <head></head>
    <body>
      <p>Some paragraph</p>
      <!-- End of HTML content in the body tag -->
    
      <script>
        <!-- Place your script tags here. -->
      </script>
    </body>
    </html>
    

How to get raw text from pdf file using java

Hi we can extract the pdf files using Apache Tika

The Example is :

import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.tika.metadata.Metadata;
import org.apache.tika.metadata.TikaCoreProperties;
import org.apache.tika.parser.AutoDetectParser;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.sax.BodyContentHandler;

public class WebPagePdfExtractor {

    public Map<String, Object> processRecord(String url) {
        DefaultHttpClient httpclient = new DefaultHttpClient();
        Map<String, Object> map = new HashMap<String, Object>();
        try {
            HttpGet httpGet = new HttpGet(url);
            HttpResponse response = httpclient.execute(httpGet);
            HttpEntity entity = response.getEntity();
            InputStream input = null;
            if (entity != null) {
                try {
                    input = entity.getContent();
                    BodyContentHandler handler = new BodyContentHandler();
                    Metadata metadata = new Metadata();
                    AutoDetectParser parser = new AutoDetectParser();
                    ParseContext parseContext = new ParseContext();
                    parser.parse(input, handler, metadata, parseContext);
                    map.put("text", handler.toString().replaceAll("\n|\r|\t", " "));
                    map.put("title", metadata.get(TikaCoreProperties.TITLE));
                    map.put("pageCount", metadata.get("xmpTPg:NPages"));
                    map.put("status_code", response.getStatusLine().getStatusCode() + "");
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                    if (input != null) {
                        try {
                            input.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            }
        } catch (Exception exception) {
            exception.printStackTrace();
        }
        return map;
    }

    public static void main(String arg[]) {
        WebPagePdfExtractor webPagePdfExtractor = new WebPagePdfExtractor();
        Map<String, Object> extractedMap = webPagePdfExtractor.processRecord("http://math.about.com/library/q20.pdf");
        System.out.println(extractedMap.get("text"));
    }

}

.gitignore is ignored by Git

Just remove the folder or file, which was committed previously in Git, by the following command. Then gitignore file will reflect the correct files.

    git rm -r -f "folder or files insides"

java.net.UnknownHostException: Invalid hostname for server: local

Trying to connect to your local computer.try with the hostname "localhost" instead or perhaps ::/ - the last one is ipv6

How to create an Oracle sequence starting with max value from a table?

DECLARE
    v_max NUMBER;
BEGIN
    SELECT (NVL (MAX (<COLUMN_NAME>), 0) + 1) INTO v_max FROM <TABLE_NAME>;
    EXECUTE IMMEDIATE 'CREATE SEQUENCE <SEQUENCE_NAME> INCREMENT BY 1 START WITH ' || v_max || ' NOCYCLE CACHE 20 NOORDER';
END;

rsync: how can I configure it to create target directory on server?

If you have more than the last leaf directory to be created, you can either run a separate ssh ... mkdir -p first, or use the --rsync-path trick as explained here :

rsync -a --rsync-path="mkdir -p /tmp/x/y/z/ && rsync" $source user@remote:/tmp/x/y/z/

Or use the --relative option as suggested by Tony. In that case, you only specify the root of the destination, which must exist, and not the directory structure of the source, which will be created:

rsync -a --relative /new/x/y/z/ user@remote:/pre_existing/dir/

This way, you will end up with /pre_existing/dir/new/x/y/z/

And if you want to have "y/z/" created, but not inside "new/x/", you can add ./ where you want --relativeto begin:

rsync -a --relative /new/x/./y/z/ user@remote:/pre_existing/dir/

would create /pre_existing/dir/y/z/.

Is it possible to auto-format your code in Dreamweaver?

ctrl+a->(click)commands->cleanup word HTML

What is the difference between Left, Right, Outer and Inner Joins?

Making it more visible might help. One example:

Table 1:

ID_STUDENT STUDENT_NAME

1               Raony
2               Diogo
3               Eduardo
4               Luiz

Table 2:

ID_STUDENT LOCKER

3               l1
4               l2
5               l3

What I get when I do:

-Inner join of Table 1 and Table 2: 

    - Inner join returns both tables merged only when the key 
      (ID_STUDENT) exists in both tables

    ID_STUDENT       STUDENT_NAME      LOCKER   

        3               Eduardo          l1
        4               Luiz             l2

-Left join of Table 1 and Table 2:

    - Left join merges both tables with all records form table 1, in 
      other words, there might be non-populated fields from table 2

    ID_ESTUDANTE    NOME_ESTUDANTE     LOCKER   

        1               Raony            -
        2               Diogo            -
        3               Eduardo          l1
        4               Luiz             l2

-Right join of table 1 and table 2:

    - Right join merges both tables with all records from table 2, in 
      other words, there might be non-populated fields from table 1

    ID_STUDENT        STUDENT_NAME     LOCKER   

        3               Eduardo          l1
        4               Luiz             l2
        5               -                l3

-Outter join of table 1 and table 2:

    - Returns all records from both tables, in other words, there
      might be non-populated fields either from table 1 or 2.

    ID_STUDENT        STUDENT_NAME     LOCKER   
        1               Raony            -
        2               Diogo            -
        3               Eduardo          l1
        4               Luiz             l2
        5               -                l3

SQL Server Error : String or binary data would be truncated

This error is usually encountered when inserting a record in a table where one of the columns is a VARCHAR or CHAR data type and the length of the value being inserted is longer than the length of the column.

I am not satisfied how Microsoft decided to inform with this "dry" response message, without any point of where to look for the answer.

How do I quickly rename a MySQL database (change schema name)?

Simplest bullet-and-fool-proof way of doing a complete rename (including dropping the old database at the end so it's a rename rather than a copy):

mysqladmin -uroot -pmypassword create newdbname
mysqldump -uroot -pmypassword --routines olddbname | mysql -uroot -pmypassword newdbname
mysqladmin -uroot -pmypassword drop olddbname

Steps:

  1. Copy the lines into Notepad.
  2. Replace all references to "olddbname", "newdbname", "mypassword" (+ optionally "root") with your equivalents.
  3. Execute one by one on the command line (entering "y" when prompted).

How to find integer array size in java

we can find length of array by using array_name.length attribute

int [] i = i.length;

What's the use of ob_start() in php?

The accepted answer here describes what ob_start() does - not why it is used (which was the question asked).

As stated elsewhere ob_start() creates a buffer which output is written to.

But nobody has mentioned that it is possible to stack multiple buffers within PHP. See ob_get_level().

As to the why....

  1. Sending HTML to the browser in larger chunks gives a performance benefit from a reduced network overhead.

  2. Passing the data out of PHP in larger chunks gives a performance and capacity benefit by reducing the number of context switches required

  3. Passing larger chunks of data to mod_gzip/mod_deflate gives a performance benefit in that the compression can be more efficient.

  4. buffering the output means that you can still manipulate the HTTP headers later in the code

  5. explicitly flushing the buffer after outputting the [head]....[/head] can allow the browser to begin marshaling other resources for the page before HTML stream completes.

  6. Capturing the output in a buffer means that it can redirected to other functions such as email, or copied to a file as a cached representation of the content

Unable to add window -- token null is not valid; is your activity running?

In my case, I was inflating a PopupMenu at the very beginning of the activity i.e on onCreate()... I fixed it by putting it in a Handler

  new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                PopupMenu popuMenu=new PopupMenu(SplashScreen.this,binding.progressBar);
                popuMenu.inflate(R.menu.bottom_nav_menu);
                popuMenu.show();
            }
        },100);

What is causing the error `string.split is not a function`?

Change this...

var string = document.location;

to this...

var string = document.location + '';

This is because document.location is a Location object. The default .toString() returns the location in string form, so the concatenation will trigger that.


You could also use document.URL to get a string.

How to store a dataframe using Pandas

Arctic is a high performance datastore for Pandas, numpy and other numeric data. It sits on top of MongoDB. Perhaps overkill for the OP, but worth mentioning for other folks stumbling across this post

JUnit test for System.out.println()

You can set the System.out print stream via setOut() (and for in and err). Can you redirect this to a print stream that records to a string, and then inspect that ? That would appear to be the simplest mechanism.

(I would advocate, at some stage, convert the app to some logging framework - but I suspect you already are aware of this!)

Jquery Value match Regex

Change it to this:

var email = /^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i;

This is a regular expression literal that is passed the i flag which means to be case insensitive.

Keep in mind that email address validation is hard (there is a 4 or 5 page regular expression at the end of Mastering Regular Expressions demonstrating this) and your expression certainly will not capture all valid e-mail addresses.

Create an Android GPS tracking application

Basically you need following things to make location detector android app

Now if you write each of these module yourself then it needs much time and efforts. So it would be better to use ready resources that are being maintained already.

Using all these resources, you will be able to create an flawless android location detection app.

1. Location Listening

You will first need to listen for current location of user. You can use any of below libraries to quick start.

Google Play Location Samples

This library provide last known location, location updates

Location Manager

With this library you just need to provide a Configuration object with your requirements, and you will receive a location or a fail reason with all the stuff are described above handled.

Live Location Sharing

Use this open source repo of the Hypertrack Live app to build live location sharing experience within your app within a few hours. HyperTrack Live app helps you share your Live Location with friends and family through your favorite messaging app when you are on the way to meet up. HyperTrack Live uses HyperTrack APIs and SDKs.

2. Markers Library

Google Maps Android API utility library

  • Marker clustering — handles the display of a large number of points
  • Heat maps — display a large number of points as a heat map
  • IconGenerator — display text on your Markers
  • Poly decoding and encoding — compact encoding for paths, interoperability with Maps API web services
  • Spherical geometry — for example: computeDistance, computeHeading, computeArea
  • KML — displays KML data
  • GeoJSON — displays and styles GeoJSON data

3. Polyline Libraries

DrawRouteMaps

If you want to add route maps feature in your apps you can use DrawRouteMaps to make you work more easier. This is lib will help you to draw route maps between two point LatLng.

trail-android

Simple, smooth animation for route / polylines on google maps using projections. (WIP)

Google-Directions-Android

This project allows you to calculate the direction between two locations and display the route on a Google Map using the Google Directions API.

A map demo app for quick start with maps

What does 'public static void' mean in Java?

It's three completely different things:

public means that the method is visible and can be called from other objects of other types. Other alternatives are private, protected, package and package-private. See here for more details.

static means that the method is associated with the class, not a specific instance (object) of that class. This means that you can call a static method without creating an object of the class.

void means that the method has no return value. If the method returned an int you would write int instead of void.

The combination of all three of these is most commonly seen on the main method which most tutorials will include.

How to validate phone numbers using regex

Note It takes as an input a US mobile number in any format and optionally accepts a second parameter - set true if you want the output mobile number formatted to look pretty. If the number provided is not a mobile number, it simple returns false. If a mobile number IS detected, it returns the entire sanitized number instead of true.

    function isValidMobile(num,format) {
        if (!format) format=false
        var m1 = /^(\W|^)[(]{0,1}\d{3}[)]{0,1}[.]{0,1}[\s-]{0,1}\d{3}[\s-]{0,1}[\s.]{0,1}\d{4}(\W|$)/
        if(!m1.test(num)) {
           return false
        }
        num = num.replace(/ /g,'').replace(/\./g,'').replace(/-/g,'').replace(/\(/g,'').replace(/\)/g,'').replace(/\[/g,'').replace(/\]/g,'').replace(/\+/g,'').replace(/\~/g,'').replace(/\{/g,'').replace(/\*/g,'').replace(/\}/g,'')
        if ((num.length < 10) || (num.length > 11) || (num.substring(0,1)=='0') || (num.substring(1,1)=='0') || ((num.length==10)&&(num.substring(0,1)=='1'))||((num.length==11)&&(num.substring(0,1)!='1'))) return false;
        num = (num.length == 11) ? num : ('1' + num);   
        if ((num.length == 11) && (num.substring(0,1) == "1")) {
            if (format===true) {
               return '(' + num.substr(1,3) + ') ' + num.substr(4,3) + '-' + num.substr(7,4)
            } else {
               return num
            }
        } else {
            return false;
        }
    }

AngularJS - Binding radio buttons to models with boolean values

 <label class="rate-hit">
     <input type="radio" ng-model="st.result" ng-value="true" ng-checked="st.result">
     Hit
 </label>
 &nbsp;&nbsp;
 <label class="rate-miss">
     <input type="radio" ng-model="st.result" ng-value="false" ng-checked="!st.result">
     Miss
 </label>

Difference between uint32 and uint32_t

uint32_t is defined in the standard, in

18.4.1 Header <cstdint> synopsis [cstdint.syn]

namespace std {
//...
typedef unsigned integer type uint32_t; // optional
//...
}

uint32 is not, it's a shortcut provided by some compilers (probably as typedef uint32_t uint32) for ease of use.

How to install iPhone application in iPhone Simulator

This thread discusses how to install the binary on the simulator. I've done it and it works: http://forums.macrumors.com/showthread.php?t=547557

From the thread:

Look inside your ~/Library/Application Support/iPhone Simulator/User/Applications/ directory and see what happens inside this directory when you install and run apps using XCode, and also when you delete apps using the Simulator.

You can run the Simulator by itself (without starting XCode).

If you start the Simulator, delete an app, quit the Simulator, put back copies of the files that were deleted from the support directory, and restart the Simulator, the app will reappear in the Simulator. Email those files with instructions about how to copy them into the appropriate support directory.

Disabling Warnings generated via _CRT_SECURE_NO_DEPRECATE

The best way to do this is by a simple check and assess. I usually do something like this:

#ifndef _DEPRECATION_DISABLE   /* One time only */
#define _DEPRECATION_DISABLE   /* Disable deprecation true */
#if (_MSC_VER >= 1400)         /* Check version */
#pragma warning(disable: 4996) /* Disable deprecation */
#endif /* #if defined(NMEA_WIN) && (_MSC_VER >= 1400) */
#endif /* #ifndef _DEPRECATION_DISABLE */

All that is really required is the following:

#pragma warning(disable: 4996)

Hasn't failed me yet; Hope this helps

How to convert a string to number in TypeScript?

You can follow either of the following ways.

var str = '54';

var num = +str; //easy way by using + operator
var num = parseInt(str); //by using the parseInt operation 

Setting active profile and config location from command line in spring boot

A way that i do this on intellij is setting an environment variable on the command like so:

test setup on intellij

In this case i am setting the profile to test

Number of days in particular month of particular year?

String date = "11-02-2000";
String[] input = date.split("-");
int day = Integer.valueOf(input[0]);
int month = Integer.valueOf(input[1]);
int year = Integer.valueOf(input[2]);
Calendar cal=Calendar.getInstance();
cal.set(Calendar.YEAR,year);
cal.set(Calendar.MONTH,month-1);
cal.set(Calendar.DATE, day);
//since month number starts from 0 (i.e jan 0, feb 1), 
//we are subtracting original month by 1
int days = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
System.out.println(days);

Batch file script to zip files

This is link by Tomas has a well written script to zip contents of a folder.

To make it work just copy the script into a batch file and execute it by specifying the folder to be zipped(source).

No need to mention destination directory as it is defaulted in the script to Desktop ("%USERPROFILE%\Desktop")

Copying the script here, just incase the web-link is down:

@ECHO OFF
SETLOCAL ENABLEDELAYEDEXPANSION

SET sourceDirPath=%1
IF [%2] EQU [] (
  SET destinationDirPath="%USERPROFILE%\Desktop"
) ELSE (
  SET destinationDirPath="%2"
)
IF [%3] EQU [] (
  SET destinationFileName="%~n1%.zip"
) ELSE (
  SET destinationFileName="%3"
)
SET tempFilePath=%TEMP%\FilesToZip.txt
TYPE NUL > %tempFilePath%

FOR /F "DELIMS=*" %%i IN ('DIR /B /S /A-D "%sourceDirPath%"') DO (
  SET filePath=%%i
  SET dirPath=%%~dpi
  SET dirPath=!dirPath:~0,-1!
  SET dirPath=!dirPath:%sourceDirPath%=!
  SET dirPath=!dirPath:%sourceDirPath%=!
  ECHO .SET DestinationDir=!dirPath! >> %tempFilePath%
  ECHO "!filePath!" >> %tempFilePath%
)

MAKECAB /D MaxDiskSize=0 /D CompressionType=MSZIP /D Cabinet=ON /D Compress=ON /D UniqueFiles=OFF /D DiskDirectoryTemplate=%destinationDirPath% /D CabinetNameTemplate=%destinationFileName%  /F %tempFilePath% > NUL 2>&1

DEL setup.inf > NUL 2>&1
DEL setup.rpt > NUL 2>&1
DEL %tempFilePath% > NUL 2>&1

How do I indent multiple lines at once in Notepad++?

Just install the NppAutoIndent plug-in, select Plugins > NppAutoIndent > Ignore Language and then Plugins > NppAutoIndent > Smart Indent.

How can I remove an element from a list?

Use - (Negative sign) along with position of element, example if 3rd element is to be removed use it as your_list[-3]

Input

my_list <- list(a = 3, b = 3, c = 4, d = "Hello", e = NA)
my_list
# $`a`
# [1] 3

# $b
# [1] 3

# $c
# [1] 4

# $d
# [1] "Hello"

# $e
# [1] NA

Remove single element from list

 my_list[-3]
 # $`a`
 # [1] 3

 # $b
 # [1] 3

 # $d
 # [1] "Hello"

 # $e
 [1] NA

Remove multiple elements from list

 my_list[c(-1,-3,-2)]
 # $`d`
 # [1] "Hello"

 # $e
 # [1] NA

 my_list[c(-3:-5)]
 # $`a`
 # [1] 3

 # $b
 # [1] 3

 my_list[-seq(1:2)]
 # $`c`
 # [1] 4

 # $d
 # [1] "Hello"

 # $e
 # [1] NA

Maven: repository element was not specified in the POM inside distributionManagement?

For me, this was something as simple as a missing version for my artifact - "1.1-SNAPSHOT"

Delete cookie by name?

//if passed exMins=0 it will delete as soon as it creates it.

function setCookie(cname, cvalue, exMins) {
    var d = new Date();
    d.setTime(d.getTime() + (exMins*60*1000));
    var expires = "expires="+d.toUTCString();  
    document.cookie = cname + "=" + cvalue + ";" + expires + ";path=/";
}

setCookie('cookieNameToDelete','',0) // this will delete the cookie.

How to create timer in angular2

I faced a problem that I had to use a timer, but I had to display them in 2 component same time, same screen. I created the timerObservable in a service. I subscribed to the timer in both component, and what happened? It won't be synched, cause new subscription always creates its own stream.

What I would like to say, is that if you plan to use one timer at several places, always put .publishReplay(1).refCount() at the end of the Observer, cause it will publish the same stream out of it every time.

Example:

this.startDateTimer = Observable.combineLatest(this.timer, this.startDate$, (localTimer, startDate) => {
  return this.calculateTime(startDate);
}).publishReplay(1).refCount();

How to get $(this) selected option in jQuery?

For the selected value: $(this).val()

If you need the selected option element, $("option:selected", this)

replace special characters in a string python

You can replace the special characters with the desired characters as follows,

import string
specialCharacterText = "H#y #@w @re &*)?"
inCharSet = "!@#$%^&*()[]{};:,./<>?\|`~-=_+\""
outCharSet = "                               " #corresponding characters in inCharSet to be replaced
splCharReplaceList = string.maketrans(inCharSet, outCharSet)
splCharFreeString = specialCharacterText.translate(splCharReplaceList)

Select2() is not a function

I was having this problem when I started using select2 with XCrud. I solved it by disabling XCrud from loading JQuery, it was it a second time, and loading it below the body tag. So make sure JQuery isn't getting loaded twice on your page.

Read and write a String from text file

It is recommended to read and write files asynchronously! and it's so easy to do in pure Swift,
here is the protocol:

protocol FileRepository {
    func read(from path: String) throws -> String
    func readAsync(from path: String, completion: @escaping (Result<String, Error>) -> Void)
    func write(_ string: String, to path: String) throws
    func writeAsync(_ string: String, to path: String, completion: @escaping (Result<Void, Error>) -> Void)
}

As you can see it allows you to read and write files synchronously or asynchronously.

Here is my implementation in Swift 5:

class DefaultFileRepository {
    
    // MARK: Properties
    
    let queue: DispatchQueue = .global()
    let fileManager: FileManager = .default
    lazy var baseURL: URL = {
        try! fileManager
            .url(for: .libraryDirectory, in: .userDomainMask, appropriateFor: nil, create: true)
            .appendingPathComponent("MyFiles")
    }()
    
    
    // MARK: Private functions
    
    private func doRead(from path: String) throws -> String {
        let url = baseURL.appendingPathComponent(path)
        
        var isDir: ObjCBool = false
        guard fileManager.fileExists(atPath: url.path, isDirectory: &isDir) && !isDir.boolValue else {
            throw ReadWriteError.doesNotExist
        }
        
        let string: String
        do {
            string = try String(contentsOf: url)
        } catch {
            throw ReadWriteError.readFailed(error)
        }
        
        return string
    }
    
    private func doWrite(_ string: String, to path: String) throws {
        let url = baseURL.appendingPathComponent(path)
        let folderURL = url.deletingLastPathComponent()
        
        var isFolderDir: ObjCBool = false
        if fileManager.fileExists(atPath: folderURL.path, isDirectory: &isFolderDir) {
            if !isFolderDir.boolValue {
                throw ReadWriteError.canNotCreateFolder
            }
        } else {
            do {
                try fileManager.createDirectory(at: folderURL, withIntermediateDirectories: true)
            } catch {
                throw ReadWriteError.canNotCreateFolder
            }
        }
        
        var isDir: ObjCBool = false
        guard !fileManager.fileExists(atPath: url.path, isDirectory: &isDir) || !isDir.boolValue else {
            throw ReadWriteError.canNotCreateFile
        }
        
        guard let data = string.data(using: .utf8) else {
            throw ReadWriteError.encodingFailed
        }
        
        do {
            try data.write(to: url)
        } catch {
            throw ReadWriteError.writeFailed(error)
        }
    }
    
}


extension DefaultFileRepository: FileRepository {
    func read(from path: String) throws -> String {
        try queue.sync { try self.doRead(from: path) }
    }
    
    func readAsync(from path: String, completion: @escaping (Result<String, Error>) -> Void) {
        queue.async {
            do {
                let result = try self.doRead(from: path)
                completion(.success(result))
            } catch {
                completion(.failure(error))
            }
        }
    }
    
    func write(_ string: String, to path: String) throws {
        try queue.sync { try self.doWrite(string, to: path) }
    }
    
    func writeAsync(_ string: String, to path: String, completion: @escaping (Result<Void, Error>) -> Void) {
        queue.async {
            do {
                try self.doWrite(string, to: path)
                completion(.success(Void()))
            } catch {
                completion(.failure(error))
            }
        }
    }
    
}


enum ReadWriteError: LocalizedError {
    
    // MARK: Cases
    
    case doesNotExist
    case readFailed(Error)
    case canNotCreateFolder
    case canNotCreateFile
    case encodingFailed
    case writeFailed(Error)
}

Spring Resttemplate exception handling

I have handled this as below:

try {
  response = restTemplate.postForEntity(requestUrl, new HttpEntity<>(requestBody, headers), String.class);
} catch (HttpStatusCodeException ex) {
  response = new ResponseEntity<String>(ex.getResponseBodyAsString(), ex.getResponseHeaders(), ex.getStatusCode());
}

Webdriver findElements By xpath

Your questions:

Q 1.) I would like to know why it returns all the texts that following the div?
It should not and I think in will not. It returns all div with 'id' attribute value equal 'containter' (and all children of this). But you are printing the results with ele.getText() Where getText will return all text content of all children of your result.

Get the visible (i.e. not hidden by CSS) innerText of this element, including sub-elements, without any leading or trailing whitespace.
Returns:
The innerText of this element.

Q 2.) how should I modify the code so it just return first or first few nodes that follow the parent note
This is not really clear what you are looking for. Example:

<p1> <div/> </p1 <p2/> 

The following to parent of the div is p2. This would be:

 //div[@id='container'][1]/parent::*/following-sibling::* 

or shorter

 //div[@id='container'][1]/../following-sibling::* 

If you are only looking for the first one extent the expression with an "predicate" (e.g [1] - for the first one. or [position() &lt; 4]for the first three)

If your are looking for the first child of the first div:

//div[@id='container'][1]/*[1]

If there is only one div with id an you are looking for the first child:

   //div[@id='container']/*[1]

and so on.

How to find out what the date was 5 days ago?

I think a readable way of doing that is:

$days_ago = date('Y-m-d', strtotime('-5 days', strtotime('2008-12-02')));

Don't understand why UnboundLocalError occurs (closure)

To modify a global variable inside a function, you must use the global keyword.

When you try to do this without the line

global counter

inside of the definition of increment, a local variable named counter is created so as to keep you from mucking up the counter variable that the whole program may depend on.

Note that you only need to use global when you are modifying the variable; you could read counter from within increment without the need for the global statement.

Make div stay at bottom of page's content all the time even when there are scrollbars

use fixed-bottom bootstrap class

<div id="footer" class="fixed-bottom w-100">

Check if a string is a valid Windows directory (folder) path

Here is a solution that leverages the use of Path.GetFullPath as recommended in the answer by @SLaks.

In the code that I am including here, note that IsValidPath(string path) is designed such that the caller does not have to worry about exception handling.

You may also find that the method that it calls, TryGetFullPath(...), also has merit on its own when you wish to safely attempt to get an absolute path.

/// <summary>
/// Gets a value that indicates whether <paramref name="path"/>
/// is a valid path.
/// </summary>
/// <returns>Returns <c>true</c> if <paramref name="path"/> is a
/// valid path; <c>false</c> otherwise. Also returns <c>false</c> if
/// the caller does not have the required permissions to access
/// <paramref name="path"/>.
/// </returns>
/// <seealso cref="Path.GetFullPath"/>
/// <seealso cref="TryGetFullPath"/>
public static bool IsValidPath(string path)
{
    string result;
    return TryGetFullPath(path, out result);
}

/// <summary>
/// Returns the absolute path for the specified path string. A return
/// value indicates whether the conversion succeeded.
/// </summary>
/// <param name="path">The file or directory for which to obtain absolute
/// path information.
/// </param>
/// <param name="result">When this method returns, contains the absolute
/// path representation of <paramref name="path"/>, if the conversion
/// succeeded, or <see cref="String.Empty"/> if the conversion failed.
/// The conversion fails if <paramref name="path"/> is null or
/// <see cref="String.Empty"/>, or is not of the correct format. This
/// parameter is passed uninitialized; any value originally supplied
/// in <paramref name="result"/> will be overwritten.
/// </param>
/// <returns><c>true</c> if <paramref name="path"/> was converted
/// to an absolute path successfully; otherwise, false.
/// </returns>
/// <seealso cref="Path.GetFullPath"/>
/// <seealso cref="IsValidPath"/>
public static bool TryGetFullPath(string path, out string result)
{
    result = String.Empty;
    if (String.IsNullOrWhiteSpace(path)) { return false; }
    bool status = false;

    try
    {
        result = Path.GetFullPath(path);
        status = true;
    }
    catch (ArgumentException) { }
    catch (SecurityException) { }
    catch (NotSupportedException) { }
    catch (PathTooLongException) { }

    return status;
}

Identify duplicates in a List

You can use something like this:

List<Integer> newList = new ArrayList<Integer>();
for(int i : yourOldList)
{
    yourOldList.remove(i);
    if(yourOldList.contains(i) && !newList.contains(i)) newList.add(i);
}

Java: Static Class?

There's no point in declaring the class as static. Just declare its methods static and call them from the class name as normal, like Java's Math class.

Also, even though it isn't strictly necessary to make the constructor private, it is a good idea to do so. Marking the constructor private prevents other people from creating instances of your class, then calling static methods from those instances. (These calls work exactly the same in Java, they're just misleading and hurt the readability of your code.)

What "wmic bios get serialnumber" actually retrieves?

wmic bios get serialnumber     

if run from a command line (start-run should also do the trick) prints out on screen the Serial Number of the product,
(for example in a toshiba laptop it would print out the serial number of the laptop.
with this serial number you can then identify your laptop model if you need ,from the makers service website-usually..:):)

I had to do exactly that.:):)

What methods of ‘clearfix’ can I use?

A new display value seems to the job in one line.

display: flow-root;

From the W3 spec: "The element generates a block container box, and lays out its contents using flow layout. It always establishes a new block formatting context for its contents."

Information: https://www.w3.org/TR/css-display-3/#valdef-display-flow-root https://www.chromestatus.com/feature/5769454877147136

?As shown in the link above, support is currently limited so fallback support like below may be of use: https://github.com/fliptheweb/postcss-flow-root

Git: "please tell me who you are" error

To fix I use: git config --global user.email "[email protected]" and works.

user.mail no work, need to put an E. Typo maybe?

What is com.sun.proxy.$Proxy

What are they?

Nothing special. Just as same as common Java Class Instance.

But those class are Synthetic proxy classes created by java.lang.reflect.Proxy#newProxyInstance

What is there relationship to the JVM? Are they JVM implementation specific?

Introduced in 1.3

http://docs.oracle.com/javase/1.3/docs/relnotes/features.html#reflection

It is a part of Java. so each JVM should support it.

How are they created (Openjdk7 source)?

In short : they are created using JVM ASM tech ( defining javabyte code at runtime )

something using same tech:

What happens after calling java.lang.reflect.Proxy#newProxyInstance

  1. reading the source you can see newProxyInstance call getProxyClass0 to obtain a `Class

    `

  2. after lots of cache or sth it calls the magic ProxyGenerator.generateProxyClass which return a byte[]
  3. call ClassLoader define class to load the generated $Proxy Class (the classname you have seen)
  4. just instance it and ready for use

What happens in magic sun.misc.ProxyGenerator

  1. draw a class(bytecode) combining all methods in the interfaces into one
  2. each method is build with same bytecode like

    1. get calling Method meth info (stored while generating)
    2. pass info into invocation handler's invoke()
    3. get return value from invocation handler's invoke()
    4. just return it
  3. the class(bytecode) represent in form of byte[]

How to draw a class

Thinking your java codes are compiled into bytecodes, just do this at runtime

Talk is cheap show you the code

core method in sun/misc/ProxyGenerator.java

generateClassFile

/**
 * Generate a class file for the proxy class.  This method drives the
 * class file generation process.
 */
private byte[] generateClassFile() {

    /* ============================================================
     * Step 1: Assemble ProxyMethod objects for all methods to
     * generate proxy dispatching code for.
     */

    /*
     * Record that proxy methods are needed for the hashCode, equals,
     * and toString methods of java.lang.Object.  This is done before
     * the methods from the proxy interfaces so that the methods from
     * java.lang.Object take precedence over duplicate methods in the
     * proxy interfaces.
     */
    addProxyMethod(hashCodeMethod, Object.class);
    addProxyMethod(equalsMethod, Object.class);
    addProxyMethod(toStringMethod, Object.class);

    /*
     * Now record all of the methods from the proxy interfaces, giving
     * earlier interfaces precedence over later ones with duplicate
     * methods.
     */
    for (int i = 0; i < interfaces.length; i++) {
        Method[] methods = interfaces[i].getMethods();
        for (int j = 0; j < methods.length; j++) {
            addProxyMethod(methods[j], interfaces[i]);
        }
    }

    /*
     * For each set of proxy methods with the same signature,
     * verify that the methods' return types are compatible.
     */
    for (List<ProxyMethod> sigmethods : proxyMethods.values()) {
        checkReturnTypes(sigmethods);
    }

    /* ============================================================
     * Step 2: Assemble FieldInfo and MethodInfo structs for all of
     * fields and methods in the class we are generating.
     */
    try {
        methods.add(generateConstructor());

        for (List<ProxyMethod> sigmethods : proxyMethods.values()) {
            for (ProxyMethod pm : sigmethods) {

                // add static field for method's Method object
                fields.add(new FieldInfo(pm.methodFieldName,
                    "Ljava/lang/reflect/Method;",
                     ACC_PRIVATE | ACC_STATIC));

                // generate code for proxy method and add it
                methods.add(pm.generateMethod());
            }
        }

        methods.add(generateStaticInitializer());

    } catch (IOException e) {
        throw new InternalError("unexpected I/O Exception");
    }

    if (methods.size() > 65535) {
        throw new IllegalArgumentException("method limit exceeded");
    }
    if (fields.size() > 65535) {
        throw new IllegalArgumentException("field limit exceeded");
    }

    /* ============================================================
     * Step 3: Write the final class file.
     */

    /*
     * Make sure that constant pool indexes are reserved for the
     * following items before starting to write the final class file.
     */
    cp.getClass(dotToSlash(className));
    cp.getClass(superclassName);
    for (int i = 0; i < interfaces.length; i++) {
        cp.getClass(dotToSlash(interfaces[i].getName()));
    }

    /*
     * Disallow new constant pool additions beyond this point, since
     * we are about to write the final constant pool table.
     */
    cp.setReadOnly();

    ByteArrayOutputStream bout = new ByteArrayOutputStream();
    DataOutputStream dout = new DataOutputStream(bout);

    try {
        /*
         * Write all the items of the "ClassFile" structure.
         * See JVMS section 4.1.
         */
                                    // u4 magic;
        dout.writeInt(0xCAFEBABE);
                                    // u2 minor_version;
        dout.writeShort(CLASSFILE_MINOR_VERSION);
                                    // u2 major_version;
        dout.writeShort(CLASSFILE_MAJOR_VERSION);

        cp.write(dout);             // (write constant pool)

                                    // u2 access_flags;
        dout.writeShort(ACC_PUBLIC | ACC_FINAL | ACC_SUPER);
                                    // u2 this_class;
        dout.writeShort(cp.getClass(dotToSlash(className)));
                                    // u2 super_class;
        dout.writeShort(cp.getClass(superclassName));

                                    // u2 interfaces_count;
        dout.writeShort(interfaces.length);
                                    // u2 interfaces[interfaces_count];
        for (int i = 0; i < interfaces.length; i++) {
            dout.writeShort(cp.getClass(
                dotToSlash(interfaces[i].getName())));
        }

                                    // u2 fields_count;
        dout.writeShort(fields.size());
                                    // field_info fields[fields_count];
        for (FieldInfo f : fields) {
            f.write(dout);
        }

                                    // u2 methods_count;
        dout.writeShort(methods.size());
                                    // method_info methods[methods_count];
        for (MethodInfo m : methods) {
            m.write(dout);
        }

                                     // u2 attributes_count;
        dout.writeShort(0); // (no ClassFile attributes for proxy classes)

    } catch (IOException e) {
        throw new InternalError("unexpected I/O Exception");
    }

    return bout.toByteArray();
}

addProxyMethod

/**
 * Add another method to be proxied, either by creating a new
 * ProxyMethod object or augmenting an old one for a duplicate
 * method.
 *
 * "fromClass" indicates the proxy interface that the method was
 * found through, which may be different from (a subinterface of)
 * the method's "declaring class".  Note that the first Method
 * object passed for a given name and descriptor identifies the
 * Method object (and thus the declaring class) that will be
 * passed to the invocation handler's "invoke" method for a given
 * set of duplicate methods.
 */
private void addProxyMethod(Method m, Class fromClass) {
    String name = m.getName();
    Class[] parameterTypes = m.getParameterTypes();
    Class returnType = m.getReturnType();
    Class[] exceptionTypes = m.getExceptionTypes();

    String sig = name + getParameterDescriptors(parameterTypes);
    List<ProxyMethod> sigmethods = proxyMethods.get(sig);
    if (sigmethods != null) {
        for (ProxyMethod pm : sigmethods) {
            if (returnType == pm.returnType) {
                /*
                 * Found a match: reduce exception types to the
                 * greatest set of exceptions that can thrown
                 * compatibly with the throws clauses of both
                 * overridden methods.
                 */
                List<Class<?>> legalExceptions = new ArrayList<Class<?>>();
                collectCompatibleTypes(
                    exceptionTypes, pm.exceptionTypes, legalExceptions);
                collectCompatibleTypes(
                    pm.exceptionTypes, exceptionTypes, legalExceptions);
                pm.exceptionTypes = new Class[legalExceptions.size()];
                pm.exceptionTypes =
                    legalExceptions.toArray(pm.exceptionTypes);
                return;
            }
        }
    } else {
        sigmethods = new ArrayList<ProxyMethod>(3);
        proxyMethods.put(sig, sigmethods);
    }
    sigmethods.add(new ProxyMethod(name, parameterTypes, returnType,
                                   exceptionTypes, fromClass));
}

Full code about gen the proxy method

    private MethodInfo generateMethod() throws IOException {
        String desc = getMethodDescriptor(parameterTypes, returnType);
        MethodInfo minfo = new MethodInfo(methodName, desc,
            ACC_PUBLIC | ACC_FINAL);

        int[] parameterSlot = new int[parameterTypes.length];
        int nextSlot = 1;
        for (int i = 0; i < parameterSlot.length; i++) {
            parameterSlot[i] = nextSlot;
            nextSlot += getWordsPerType(parameterTypes[i]);
        }
        int localSlot0 = nextSlot;
        short pc, tryBegin = 0, tryEnd;

        DataOutputStream out = new DataOutputStream(minfo.code);

        code_aload(0, out);

        out.writeByte(opc_getfield);
        out.writeShort(cp.getFieldRef(
            superclassName,
            handlerFieldName, "Ljava/lang/reflect/InvocationHandler;"));

        code_aload(0, out);

        out.writeByte(opc_getstatic);
        out.writeShort(cp.getFieldRef(
            dotToSlash(className),
            methodFieldName, "Ljava/lang/reflect/Method;"));

        if (parameterTypes.length > 0) {

            code_ipush(parameterTypes.length, out);

            out.writeByte(opc_anewarray);
            out.writeShort(cp.getClass("java/lang/Object"));

            for (int i = 0; i < parameterTypes.length; i++) {

                out.writeByte(opc_dup);

                code_ipush(i, out);

                codeWrapArgument(parameterTypes[i], parameterSlot[i], out);

                out.writeByte(opc_aastore);
            }
        } else {

            out.writeByte(opc_aconst_null);
        }

        out.writeByte(opc_invokeinterface);
        out.writeShort(cp.getInterfaceMethodRef(
            "java/lang/reflect/InvocationHandler",
            "invoke",
            "(Ljava/lang/Object;Ljava/lang/reflect/Method;" +
                "[Ljava/lang/Object;)Ljava/lang/Object;"));
        out.writeByte(4);
        out.writeByte(0);

        if (returnType == void.class) {

            out.writeByte(opc_pop);

            out.writeByte(opc_return);

        } else {

            codeUnwrapReturnValue(returnType, out);
        }

        tryEnd = pc = (short) minfo.code.size();

        List<Class<?>> catchList = computeUniqueCatchList(exceptionTypes);
        if (catchList.size() > 0) {

            for (Class<?> ex : catchList) {
                minfo.exceptionTable.add(new ExceptionTableEntry(
                    tryBegin, tryEnd, pc,
                    cp.getClass(dotToSlash(ex.getName()))));
            }

            out.writeByte(opc_athrow);

            pc = (short) minfo.code.size();

            minfo.exceptionTable.add(new ExceptionTableEntry(
                tryBegin, tryEnd, pc, cp.getClass("java/lang/Throwable")));

            code_astore(localSlot0, out);

            out.writeByte(opc_new);
            out.writeShort(cp.getClass(
                "java/lang/reflect/UndeclaredThrowableException"));

            out.writeByte(opc_dup);

            code_aload(localSlot0, out);

            out.writeByte(opc_invokespecial);

            out.writeShort(cp.getMethodRef(
                "java/lang/reflect/UndeclaredThrowableException",
                "<init>", "(Ljava/lang/Throwable;)V"));

            out.writeByte(opc_athrow);
        }

COUNT / GROUP BY with active record?

$this->db->select('overal_points');
$this->db->where('point_publish', 1);
$this->db->order_by('overal_points', 'desc'); 
$query = $this->db->get('company', 4)->result();

How to detect the character encoding of a text file?

If you want to pursue a "simple" solution, you might find this class I put together useful:

http://www.architectshack.com/TextFileEncodingDetector.ashx

It does the BOM detection automatically first, and then tries to differentiate between Unicode encodings without BOM, vs some other default encoding (generally Windows-1252, incorrectly labelled as Encoding.ASCII in .Net).

As noted above, a "heavier" solution involving NCharDet or MLang may be more appropriate, and as I note on the overview page of this class, the best is to provide some form of interactivity with the user if at all possible, because there simply is no 100% detection rate possible!

Snippet in case the site is offline:

using System;
using System.Text;
using System.Text.RegularExpressions;
using System.IO;

namespace KlerksSoft
{
    public static class TextFileEncodingDetector
    {
        /*
         * Simple class to handle text file encoding woes (in a primarily English-speaking tech 
         *      world).
         * 
         *  - This code is fully managed, no shady calls to MLang (the unmanaged codepage
         *      detection library originally developed for Internet Explorer).
         * 
         *  - This class does NOT try to detect arbitrary codepages/charsets, it really only
         *      aims to differentiate between some of the most common variants of Unicode 
         *      encoding, and a "default" (western / ascii-based) encoding alternative provided
         *      by the caller.
         *      
         *  - As there is no "Reliable" way to distinguish between UTF-8 (without BOM) and 
         *      Windows-1252 (in .Net, also incorrectly called "ASCII") encodings, we use a 
         *      heuristic - so the more of the file we can sample the better the guess. If you 
         *      are going to read the whole file into memory at some point, then best to pass 
         *      in the whole byte byte array directly. Otherwise, decide how to trade off 
         *      reliability against performance / memory usage.
         *      
         *  - The UTF-8 detection heuristic only works for western text, as it relies on 
         *      the presence of UTF-8 encoded accented and other characters found in the upper 
         *      ranges of the Latin-1 and (particularly) Windows-1252 codepages.
         *  
         *  - For more general detection routines, see existing projects / resources:
         *    - MLang - Microsoft library originally for IE6, available in Windows XP and later APIs now (I think?)
         *      - MLang .Net bindings: http://www.codeproject.com/KB/recipes/DetectEncoding.aspx
         *    - CharDet - Mozilla browser's detection routines
         *      - Ported to Java then .Net: http://www.conceptdevelopment.net/Localization/NCharDet/
         *      - Ported straight to .Net: http://code.google.com/p/chardetsharp/source/browse
         *  
         * Copyright Tao Klerks, 2010-2012, [email protected]
         * Licensed under the modified BSD license:
         * 
Redistribution and use in source and binary forms, with or without modification, are 
permitted provided that the following conditions are met:
 - Redistributions of source code must retain the above copyright notice, this list of 
conditions and the following disclaimer.
 - Redistributions in binary form must reproduce the above copyright notice, this list 
of conditions and the following disclaimer in the documentation and/or other materials
provided with the distribution.
 - The name of the author may not be used to endorse or promote products derived from 
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
OF SUCH DAMAGE.
         * 
         * CHANGELOG:
         *  - 2012-02-03: 
         *    - Simpler methods, removing the silly "DefaultEncoding" parameter (with "??" operator, saves no typing)
         *    - More complete methods
         *      - Optionally return indication of whether BOM was found in "Detect" methods
         *      - Provide straight-to-string method for byte arrays (GetStringFromByteArray)
         */

        const long _defaultHeuristicSampleSize = 0x10000; //completely arbitrary - inappropriate for high numbers of files / high speed requirements

        public static Encoding DetectTextFileEncoding(string InputFilename)
        {
            using (FileStream textfileStream = File.OpenRead(InputFilename))
            {
                return DetectTextFileEncoding(textfileStream, _defaultHeuristicSampleSize);
            }
        }

        public static Encoding DetectTextFileEncoding(FileStream InputFileStream, long HeuristicSampleSize)
        {
            bool uselessBool = false;
            return DetectTextFileEncoding(InputFileStream, _defaultHeuristicSampleSize, out uselessBool);
        }

        public static Encoding DetectTextFileEncoding(FileStream InputFileStream, long HeuristicSampleSize, out bool HasBOM)
        {
            if (InputFileStream == null)
                throw new ArgumentNullException("Must provide a valid Filestream!", "InputFileStream");

            if (!InputFileStream.CanRead)
                throw new ArgumentException("Provided file stream is not readable!", "InputFileStream");

            if (!InputFileStream.CanSeek)
                throw new ArgumentException("Provided file stream cannot seek!", "InputFileStream");

            Encoding encodingFound = null;

            long originalPos = InputFileStream.Position;

            InputFileStream.Position = 0;


            //First read only what we need for BOM detection
            byte[] bomBytes = new byte[InputFileStream.Length > 4 ? 4 : InputFileStream.Length];
            InputFileStream.Read(bomBytes, 0, bomBytes.Length);

            encodingFound = DetectBOMBytes(bomBytes);

            if (encodingFound != null)
            {
                InputFileStream.Position = originalPos;
                HasBOM = true;
                return encodingFound;
            }


            //BOM Detection failed, going for heuristics now.
            //  create sample byte array and populate it
            byte[] sampleBytes = new byte[HeuristicSampleSize > InputFileStream.Length ? InputFileStream.Length : HeuristicSampleSize];
            Array.Copy(bomBytes, sampleBytes, bomBytes.Length);
            if (InputFileStream.Length > bomBytes.Length)
                InputFileStream.Read(sampleBytes, bomBytes.Length, sampleBytes.Length - bomBytes.Length);
            InputFileStream.Position = originalPos;

            //test byte array content
            encodingFound = DetectUnicodeInByteSampleByHeuristics(sampleBytes);

            HasBOM = false;
            return encodingFound;
        }

        public static Encoding DetectTextByteArrayEncoding(byte[] TextData)
        {
            bool uselessBool = false;
            return DetectTextByteArrayEncoding(TextData, out uselessBool);
        }

        public static Encoding DetectTextByteArrayEncoding(byte[] TextData, out bool HasBOM)
        {
            if (TextData == null)
                throw new ArgumentNullException("Must provide a valid text data byte array!", "TextData");

            Encoding encodingFound = null;

            encodingFound = DetectBOMBytes(TextData);

            if (encodingFound != null)
            {
                HasBOM = true;
                return encodingFound;
            }
            else
            {
                //test byte array content
                encodingFound = DetectUnicodeInByteSampleByHeuristics(TextData);

                HasBOM = false;
                return encodingFound;
            }
        }

        public static string GetStringFromByteArray(byte[] TextData, Encoding DefaultEncoding)
        {
            return GetStringFromByteArray(TextData, DefaultEncoding, _defaultHeuristicSampleSize);
        }

        public static string GetStringFromByteArray(byte[] TextData, Encoding DefaultEncoding, long MaxHeuristicSampleSize)
        {
            if (TextData == null)
                throw new ArgumentNullException("Must provide a valid text data byte array!", "TextData");

            Encoding encodingFound = null;

            encodingFound = DetectBOMBytes(TextData);

            if (encodingFound != null)
            {
                //For some reason, the default encodings don't detect/swallow their own preambles!!
                return encodingFound.GetString(TextData, encodingFound.GetPreamble().Length, TextData.Length - encodingFound.GetPreamble().Length);
            }
            else
            {
                byte[] heuristicSample = null;
                if (TextData.Length > MaxHeuristicSampleSize)
                {
                    heuristicSample = new byte[MaxHeuristicSampleSize];
                    Array.Copy(TextData, heuristicSample, MaxHeuristicSampleSize);
                }
                else
                {
                    heuristicSample = TextData;
                }

                encodingFound = DetectUnicodeInByteSampleByHeuristics(TextData) ?? DefaultEncoding;
                return encodingFound.GetString(TextData);
            }
        }


        public static Encoding DetectBOMBytes(byte[] BOMBytes)
        {
            if (BOMBytes == null)
                throw new ArgumentNullException("Must provide a valid BOM byte array!", "BOMBytes");

            if (BOMBytes.Length < 2)
                return null;

            if (BOMBytes[0] == 0xff 
                && BOMBytes[1] == 0xfe 
                && (BOMBytes.Length < 4 
                    || BOMBytes[2] != 0 
                    || BOMBytes[3] != 0
                    )
                )
                return Encoding.Unicode;

            if (BOMBytes[0] == 0xfe 
                && BOMBytes[1] == 0xff
                )
                return Encoding.BigEndianUnicode;

            if (BOMBytes.Length < 3)
                return null;

            if (BOMBytes[0] == 0xef && BOMBytes[1] == 0xbb && BOMBytes[2] == 0xbf)
                return Encoding.UTF8;

            if (BOMBytes[0] == 0x2b && BOMBytes[1] == 0x2f && BOMBytes[2] == 0x76)
                return Encoding.UTF7;

            if (BOMBytes.Length < 4)
                return null;

            if (BOMBytes[0] == 0xff && BOMBytes[1] == 0xfe && BOMBytes[2] == 0 && BOMBytes[3] == 0)
                return Encoding.UTF32;

            if (BOMBytes[0] == 0 && BOMBytes[1] == 0 && BOMBytes[2] == 0xfe && BOMBytes[3] == 0xff)
                return Encoding.GetEncoding(12001);

            return null;
        }

        public static Encoding DetectUnicodeInByteSampleByHeuristics(byte[] SampleBytes)
        {
            long oddBinaryNullsInSample = 0;
            long evenBinaryNullsInSample = 0;
            long suspiciousUTF8SequenceCount = 0;
            long suspiciousUTF8BytesTotal = 0;
            long likelyUSASCIIBytesInSample = 0;

            //Cycle through, keeping count of binary null positions, possible UTF-8 
            //  sequences from upper ranges of Windows-1252, and probable US-ASCII 
            //  character counts.

            long currentPos = 0;
            int skipUTF8Bytes = 0;

            while (currentPos < SampleBytes.Length)
            {
                //binary null distribution
                if (SampleBytes[currentPos] == 0)
                {
                    if (currentPos % 2 == 0)
                        evenBinaryNullsInSample++;
                    else
                        oddBinaryNullsInSample++;
                }

                //likely US-ASCII characters
                if (IsCommonUSASCIIByte(SampleBytes[currentPos]))
                    likelyUSASCIIBytesInSample++;

                //suspicious sequences (look like UTF-8)
                if (skipUTF8Bytes == 0)
                {
                    int lengthFound = DetectSuspiciousUTF8SequenceLength(SampleBytes, currentPos);

                    if (lengthFound > 0)
                    {
                        suspiciousUTF8SequenceCount++;
                        suspiciousUTF8BytesTotal += lengthFound;
                        skipUTF8Bytes = lengthFound - 1;
                    }
                }
                else
                {
                    skipUTF8Bytes--;
                }

                currentPos++;
            }

            //1: UTF-16 LE - in english / european environments, this is usually characterized by a 
            //  high proportion of odd binary nulls (starting at 0), with (as this is text) a low 
            //  proportion of even binary nulls.
            //  The thresholds here used (less than 20% nulls where you expect non-nulls, and more than
            //  60% nulls where you do expect nulls) are completely arbitrary.

            if (((evenBinaryNullsInSample * 2.0) / SampleBytes.Length) < 0.2 
                && ((oddBinaryNullsInSample * 2.0) / SampleBytes.Length) > 0.6
                )
                return Encoding.Unicode;


            //2: UTF-16 BE - in english / european environments, this is usually characterized by a 
            //  high proportion of even binary nulls (starting at 0), with (as this is text) a low 
            //  proportion of odd binary nulls.
            //  The thresholds here used (less than 20% nulls where you expect non-nulls, and more than
            //  60% nulls where you do expect nulls) are completely arbitrary.

            if (((oddBinaryNullsInSample * 2.0) / SampleBytes.Length) < 0.2 
                && ((evenBinaryNullsInSample * 2.0) / SampleBytes.Length) > 0.6
                )
                return Encoding.BigEndianUnicode;


            //3: UTF-8 - Martin Dürst outlines a method for detecting whether something CAN be UTF-8 content 
            //  using regexp, in his w3c.org unicode FAQ entry: 
            //  http://www.w3.org/International/questions/qa-forms-utf-8
            //  adapted here for C#.
            string potentiallyMangledString = Encoding.ASCII.GetString(SampleBytes);
            Regex UTF8Validator = new Regex(@"\A(" 
                + @"[\x09\x0A\x0D\x20-\x7E]"
                + @"|[\xC2-\xDF][\x80-\xBF]"
                + @"|\xE0[\xA0-\xBF][\x80-\xBF]"
                + @"|[\xE1-\xEC\xEE\xEF][\x80-\xBF]{2}"
                + @"|\xED[\x80-\x9F][\x80-\xBF]"
                + @"|\xF0[\x90-\xBF][\x80-\xBF]{2}"
                + @"|[\xF1-\xF3][\x80-\xBF]{3}"
                + @"|\xF4[\x80-\x8F][\x80-\xBF]{2}"
                + @")*\z");
            if (UTF8Validator.IsMatch(potentiallyMangledString))
            {
                //Unfortunately, just the fact that it CAN be UTF-8 doesn't tell you much about probabilities.
                //If all the characters are in the 0-127 range, no harm done, most western charsets are same as UTF-8 in these ranges.
                //If some of the characters were in the upper range (western accented characters), however, they would likely be mangled to 2-byte by the UTF-8 encoding process.
                // So, we need to play stats.

                // The "Random" likelihood of any pair of randomly generated characters being one 
                //   of these "suspicious" character sequences is:
                //     128 / (256 * 256) = 0.2%.
                //
                // In western text data, that is SIGNIFICANTLY reduced - most text data stays in the <127 
                //   character range, so we assume that more than 1 in 500,000 of these character 
                //   sequences indicates UTF-8. The number 500,000 is completely arbitrary - so sue me.
                //
                // We can only assume these character sequences will be rare if we ALSO assume that this
                //   IS in fact western text - in which case the bulk of the UTF-8 encoded data (that is 
                //   not already suspicious sequences) should be plain US-ASCII bytes. This, I 
                //   arbitrarily decided, should be 80% (a random distribution, eg binary data, would yield 
                //   approx 40%, so the chances of hitting this threshold by accident in random data are 
                //   VERY low). 

                if ((suspiciousUTF8SequenceCount * 500000.0 / SampleBytes.Length >= 1) //suspicious sequences
                    && (
                           //all suspicious, so cannot evaluate proportion of US-Ascii
                           SampleBytes.Length - suspiciousUTF8BytesTotal == 0 
                           ||
                           likelyUSASCIIBytesInSample * 1.0 / (SampleBytes.Length - suspiciousUTF8BytesTotal) >= 0.8
                       )
                    )
                    return Encoding.UTF8;
            }

            return null;
        }

        private static bool IsCommonUSASCIIByte(byte testByte)
        {
            if (testByte == 0x0A //lf
                || testByte == 0x0D //cr
                || testByte == 0x09 //tab
                || (testByte >= 0x20 && testByte <= 0x2F) //common punctuation
                || (testByte >= 0x30 && testByte <= 0x39) //digits
                || (testByte >= 0x3A && testByte <= 0x40) //common punctuation
                || (testByte >= 0x41 && testByte <= 0x5A) //capital letters
                || (testByte >= 0x5B && testByte <= 0x60) //common punctuation
                || (testByte >= 0x61 && testByte <= 0x7A) //lowercase letters
                || (testByte >= 0x7B && testByte <= 0x7E) //common punctuation
                )
                return true;
            else
                return false;
        }

        private static int DetectSuspiciousUTF8SequenceLength(byte[] SampleBytes, long currentPos)
        {
            int lengthFound = 0;

            if (SampleBytes.Length >= currentPos + 1 
                && SampleBytes[currentPos] == 0xC2
                )
            {
                if (SampleBytes[currentPos + 1] == 0x81 
                    || SampleBytes[currentPos + 1] == 0x8D 
                    || SampleBytes[currentPos + 1] == 0x8F
                    )
                    lengthFound = 2;
                else if (SampleBytes[currentPos + 1] == 0x90 
                    || SampleBytes[currentPos + 1] == 0x9D
                    )
                    lengthFound = 2;
                else if (SampleBytes[currentPos + 1] >= 0xA0 
                    && SampleBytes[currentPos + 1] <= 0xBF
                    )
                    lengthFound = 2;
            }
            else if (SampleBytes.Length >= currentPos + 1 
                && SampleBytes[currentPos] == 0xC3
                )
            {
                if (SampleBytes[currentPos + 1] >= 0x80 
                    && SampleBytes[currentPos + 1] <= 0xBF
                    )
                    lengthFound = 2;
            }
            else if (SampleBytes.Length >= currentPos + 1 
                && SampleBytes[currentPos] == 0xC5
                )
            {
                if (SampleBytes[currentPos + 1] == 0x92 
                    || SampleBytes[currentPos + 1] == 0x93
                    )
                    lengthFound = 2;
                else if (SampleBytes[currentPos + 1] == 0xA0 
                    || SampleBytes[currentPos + 1] == 0xA1
                    )
                    lengthFound = 2;
                else if (SampleBytes[currentPos + 1] == 0xB8 
                    || SampleBytes[currentPos + 1] == 0xBD 
                    || SampleBytes[currentPos + 1] == 0xBE
                    )
                    lengthFound = 2;
            }
            else if (SampleBytes.Length >= currentPos + 1 
                && SampleBytes[currentPos] == 0xC6
                )
            {
                if (SampleBytes[currentPos + 1] == 0x92)
                    lengthFound = 2;
            }
            else if (SampleBytes.Length >= currentPos + 1 
                && SampleBytes[currentPos] == 0xCB
                )
            {
                if (SampleBytes[currentPos + 1] == 0x86 
                    || SampleBytes[currentPos + 1] == 0x9C
                    )
                    lengthFound = 2;
            }
            else if (SampleBytes.Length >= currentPos + 2 
                && SampleBytes[currentPos] == 0xE2
                )
            {
                if (SampleBytes[currentPos + 1] == 0x80)
                {
                    if (SampleBytes[currentPos + 2] == 0x93 
                        || SampleBytes[currentPos + 2] == 0x94
                        )
                        lengthFound = 3;
                    if (SampleBytes[currentPos + 2] == 0x98 
                        || SampleBytes[currentPos + 2] == 0x99 
                        || SampleBytes[currentPos + 2] == 0x9A
                        )
                        lengthFound = 3;
                    if (SampleBytes[currentPos + 2] == 0x9C 
                        || SampleBytes[currentPos + 2] == 0x9D 
                        || SampleBytes[currentPos + 2] == 0x9E
                        )
                        lengthFound = 3;
                    if (SampleBytes[currentPos + 2] == 0xA0 
                        || SampleBytes[currentPos + 2] == 0xA1 
                        || SampleBytes[currentPos + 2] == 0xA2
                        )
                        lengthFound = 3;
                    if (SampleBytes[currentPos + 2] == 0xA6)
                        lengthFound = 3;
                    if (SampleBytes[currentPos + 2] == 0xB0)
                        lengthFound = 3;
                    if (SampleBytes[currentPos + 2] == 0xB9 
                        || SampleBytes[currentPos + 2] == 0xBA
                        )
                        lengthFound = 3;
                }
                else if (SampleBytes[currentPos + 1] == 0x82 
                    && SampleBytes[currentPos + 2] == 0xAC
                    )
                    lengthFound = 3;
                else if (SampleBytes[currentPos + 1] == 0x84 
                    && SampleBytes[currentPos + 2] == 0xA2
                    )
                    lengthFound = 3;
            }

            return lengthFound;
        }

    }
}

Resize Cross Domain Iframe Height

If you have access to manipulate the code of the site you are loading, the following should provide a comprehensive method to updating the height of the iframe container anytime the height of the framed content changes.

Add the following code to the pages you are loading (perhaps in a header). This code sends a message containing the height of the HTML container any time the DOM is updated (if you're lazy loading) or the window is resized (when the user modifies the browser).

window.addEventListener("load", function(){
    if(window.self === window.top) return; // if w.self === w.top, we are not in an iframe 
    send_height_to_parent_function = function(){
        var height = document.getElementsByTagName("html")[0].clientHeight;
        //console.log("Sending height as " + height + "px");
        parent.postMessage({"height" : height }, "*");
    }
    // send message to parent about height updates
    send_height_to_parent_function(); //whenever the page is loaded
    window.addEventListener("resize", send_height_to_parent_function); // whenever the page is resized
    var observer = new MutationObserver(send_height_to_parent_function);           // whenever DOM changes PT1
    var config = { attributes: true, childList: true, characterData: true, subtree:true}; // PT2
    observer.observe(window.document, config);                                            // PT3 
});

Add the following code to the page that the iframe is stored on. This will update the height of the iframe, given that the message came from the page that that iframe loads.

<script>
window.addEventListener("message", function(e){
    var this_frame = document.getElementById("healthy_behavior_iframe");
    if (this_frame.contentWindow === e.source) {
        this_frame.height = e.data.height + "px";
        this_frame.style.height = e.data.height + "px";
    }
})
</script>

ObservableCollection not noticing when Item in it changes (even with INotifyPropertyChanged)

ObservableCollection will not propagate individual item changes as CollectionChanged events. You will either need to subscribe to each event and forward it manually, or you can check out the BindingList[T] class, which will do this for you.

Console.log(); How to & Debugging javascript

Learn to use a javascript debugger. Venkman (for Firefox) or the Web Inspector (part of Chome & Safari) are excellent tools for debugging what's going on.

You can set breakpoints and interrogate the state of the machine as you're interacting with your script; step through parts of your code to make sure everything is working as planned, etc.

Here is an excellent write up from WebMonkey on JavaScript Debugging for Beginners. It's a great place to start.

How can I use JSON data to populate the options of a select box?

Given returned json from your://site.com:

[{text:"Text1", val:"Value1"},
{text:"Text2", val:"Value2"},
{text:"Text3", val:"Value3"}]

Use this:

    $.getJSON("your://site.com", function(json){
            $('#select').empty();
            $('#select').append($('<option>').text("Select"));
            $.each(json, function(i, obj){
                    $('#select').append($('<option>').text(obj.text).attr('value', obj.val));
            });
    });

How to set column header text for specific column in Datagridview C#

private void datagrid_ColumnHeaderMouseClick(object sender, DataGridViewCellMouseEventArgs e)
{
    string test = this.datagrid.Columns[e.ColumnIndex].HeaderText;
}

This code will get the HeaderText value.

Check if an HTML input element is empty or has no value entered by user

var input = document.getElementById("customx");

if (input && input.value) {
    alert(1);
}
else {
    alert (0);
}

Nuget connection attempt failed "Unable to load the service index for source"

If you are behind a company proxy and on Mac, just make sure your http/https checkboxes are checked and applied.

Visual Studio loading symbols

Configure in Tools, Options, Debugging, Symbols.

You can watch the output window (view, output) to see what it's doing usually. If it's really slow that probably means it's hitting a symbol server, probably Microsoft's, to download missing symbols. This takes three HTTP hits for each file it can't find on every startup - you can sometimes see this in the status bar at the bottom or in e.g. Fiddler. You can see which modules have loaded symbols in Debug, Windows, Modules whilst you're debugging.

Symbols mean you get useful stack trace information into third party and system assemblies. You definitely need them for your own code, but I think those get loaded regardless. Your best bet is to turn off any non-local symbol sources in that menu and, if you're loading lots of symbols for system assemblies that you don't need to debug into you can temporarily disable loading those to speed up debug start - but they're often useful to have loaded.

onMeasure custom view explanation

If you don't need to change something onMeasure - there's absolutely no need for you to override it.

Devunwired code (the selected and most voted answer here) is almost identical to what the SDK implementation already does for you (and I checked - it had done that since 2009).

You can check the onMeasure method here :

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    setMeasuredDimension(getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec),
            getDefaultSize(getSuggestedMinimumHeight(), heightMeasureSpec));
}

public static int getDefaultSize(int size, int measureSpec) {
    int result = size;
    int specMode = MeasureSpec.getMode(measureSpec);
    int specSize = MeasureSpec.getSize(measureSpec);

    switch (specMode) {
    case MeasureSpec.UNSPECIFIED:
        result = size;
        break;
    case MeasureSpec.AT_MOST:
    case MeasureSpec.EXACTLY:
        result = specSize;
        break;
    }
    return result;
}

Overriding SDK code to be replaced with the exact same code makes no sense.

This official doc's piece that claims "the default onMeasure() will always set a size of 100x100" - is wrong.

How to stop Python closing immediately when executed in Microsoft Windows

In Python 2.7 adding this to the end of my py file (if __name__ == '__main__':) works:

closeInput = raw_input("Press ENTER to exit")
print "Closing..."

How to disable horizontal scrolling of UIScrollView?

Introduced in iOS 11 is a new property on UIScrollView

var contentLayoutGuide: UILayoutGuide

The documentation states that you:

Use this layout guide when you want to create Auto Layout constraints related to the content area of a scroll view.

Along with any other Autolayout constraints that you might be adding you will want to constrain the widthAnchor of the UIScrollView's contentLayoutGuide to be the same size as the "frame". You can use the frameLayoutGuide (also introduced in iOS 11) or any external width (such as your superView's.)

example:

NSLayoutConstraint.activate([
  scrollView.contentLayoutGuide.widthAnchor.constraint(equalTo: self.widthAnchor)
])

Documentation: https://developer.apple.com/documentation/uikit/uiscrollview/2865870-contentlayoutguide

Custom fonts and XML layouts (Android)

You can't extend TextView to create a widget or use one in a widgets layout: http://developer.android.com/guide/topics/appwidgets/index.html

Forward host port to docker container

A simple but relatively insecure way would be to use the --net=host option to docker run.

This option makes it so that the container uses the networking stack of the host. Then you can connect to services running on the host simply by using "localhost" as the hostname.

This is easier to configure because you won't have to configure the service to accept connections from the IP address of your docker container, and you won't have to tell the docker container a specific IP address or host name to connect to, just a port.

For example, you can test it out by running the following command, which assumes your image is called my_image, your image includes the telnet utility, and the service you want to connect to is on port 25:

docker run --rm -i -t --net=host my_image telnet localhost 25

If you consider doing it this way, please see the caution about security on this page:

https://docs.docker.com/articles/networking/

It says:

--net=host -- Tells Docker to skip placing the container inside of a separate network stack. In essence, this choice tells Docker to not containerize the container's networking! While container processes will still be confined to their own filesystem and process list and resource limits, a quick ip addr command will show you that, network-wise, they live “outside” in the main Docker host and have full access to its network interfaces. Note that this does not let the container reconfigure the host network stack — that would require --privileged=true — but it does let container processes open low-numbered ports like any other root process. It also allows the container to access local network services like D-bus. This can lead to processes in the container being able to do unexpected things like restart your computer. You should use this option with caution.

How to compile makefile using MinGW?

You have to actively choose to install MSYS to get the make.exe. So you should always have at least (the native) mingw32-make.exe if MinGW was installed properly. And if you installed MSYS you will have make.exe (in the MSYS subfolder probably).

Note that many projects require first creating a makefile (e.g. using a configure script or automake .am file) and it is this step that requires MSYS or cygwin. Makes you wonder why they bothered to distribute the native make at all.

Once you have the makefile, it is unclear if the native executable requires a different path separator than the MSYS make (forward slashes vs backward slashes). Any autogenerated makefile is likely to have unix-style paths, assuming the native make can handle those, the compiled output should be the same.

Remove insignificant trailing zeros from a number?

I had the basically the same requirement, and found that there is no built-in mechanism for this functionality.

In addition to trimming the trailing zeros, I also had the need to round off and format the output for the user's current locale (i.e. 123,456.789).

All of my work on this has been included as prettyFloat.js (MIT Licensed) on GitHub: https://github.com/dperish/prettyFloat.js


Usage Examples:

prettyFloat(1.111001, 3) // "1.111"
prettyFloat(1.111001, 4) // "1.111"
prettyFloat(1.1111001, 5) // "1.1111"
prettyFloat(1234.5678, 2) // "1234.57"
prettyFloat(1234.5678, 2, true) // "1,234.57" (en-us)


Updated - August, 2018


All modern browsers now support the ECMAScript Internationalization API, which provides language sensitive string comparison, number formatting, and date and time formatting.

let formatters = {
    default: new Intl.NumberFormat(),
    currency: new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD', minimumFractionDigits: 0, maximumFractionDigits: 0 }),
    whole: new Intl.NumberFormat('en-US', { style: 'decimal', minimumFractionDigits: 0, maximumFractionDigits: 0 }),
    oneDecimal: new Intl.NumberFormat('en-US', { style: 'decimal', minimumFractionDigits: 1, maximumFractionDigits: 1 }),
    twoDecimal: new Intl.NumberFormat('en-US', { style: 'decimal', minimumFractionDigits: 2, maximumFractionDigits: 2 })
};

formatters.twoDecimal.format(1234.5678);  // result: "1,234.57"
formatters.currency.format(28761232.291); // result: "$28,761,232"

For older browsers, you can use this polyfill: https://cdn.polyfill.io/v2/polyfill.min.js?features=Intl.~locale.en

Java SSL: how to disable hostname verification

It should be possible to create custom java agent that overrides default HostnameVerifier:

import javax.net.ssl.*;
import java.lang.instrument.Instrumentation;

public class LenientHostnameVerifierAgent {
    public static void premain(String args, Instrumentation inst) {
        HttpsURLConnection.setDefaultHostnameVerifier(new HostnameVerifier() {
            public boolean verify(String s, SSLSession sslSession) {
                return true;
            }
        });
    }
}

Then just add -javaagent:LenientHostnameVerifierAgent.jar to program's java startup arguments.

Docker error response from daemon: "Conflict ... already in use by container"

For people landing here from google like me and just want to build containers using multiple docker-compose files with one shared service:

Sometimes you have different projects that would share e.g. a database docker container. Only the first run should start the DB-Docker, the second should be detect that the DB is already running and skip this. To achieve such a behaviour we need the Dockers to lay in the same network and in the same project. Also the docker container name needs to be the same.

1st: Set the same network and container name in docker-compose

docker-compose in project 1:

version: '3'

services:
    service1:
        depends_on:
            - postgres
        # ...
        networks:
            - dockernet

    postgres:
        container_name: project_postgres
        image: postgres:10-alpine
        restart: always
        # ...
        networks:
            - dockernet

networks:
    dockernet:

docker-compose in project 2:

version: '3'

services:
    service2:
        depends_on:
            - postgres
        # ...
        networks:
            - dockernet

    postgres:
        container_name: project_postgres
        image: postgres:10-alpine
        restart: always
        # ...
        networks:
            - dockernet

networks:
    dockernet:

2nd: Set the same project using -p param or put both files in the same directory.

docker-compose -p {projectname} up

Go / golang time.Now().UnixNano() convert to milliseconds?

At https://github.com/golang/go/issues/44196 randall77 suggested

time.Now().Sub(time.Unix(0,0)).Milliseconds()

which exploits the fact that Go's time.Duration already have Milliseconds method.

Read file line by line using ifstream in C++

Since your coordinates belong together as pairs, why not write a struct for them?

struct CoordinatePair
{
    int x;
    int y;
};

Then you can write an overloaded extraction operator for istreams:

std::istream& operator>>(std::istream& is, CoordinatePair& coordinates)
{
    is >> coordinates.x >> coordinates.y;

    return is;
}

And then you can read a file of coordinates straight into a vector like this:

#include <fstream>
#include <iterator>
#include <vector>

int main()
{
    char filename[] = "coordinates.txt";
    std::vector<CoordinatePair> v;
    std::ifstream ifs(filename);
    if (ifs) {
        std::copy(std::istream_iterator<CoordinatePair>(ifs), 
                std::istream_iterator<CoordinatePair>(),
                std::back_inserter(v));
    }
    else {
        std::cerr << "Couldn't open " << filename << " for reading\n";
    }
    // Now you can work with the contents of v
}

What tool to use to draw file tree diagram

The advice to use Graphviz is good: you can generate the dot file and it will do the hard work of measuring strings, doing the layout, etc. Plus it can output the graphs in lot of formats, including vector ones.

I found a Perl program doing precisely that, in a mailing list, but I just can't find it back! I copied the sample dot file and studied it, since I don't know much of this declarative syntax and I wanted to learn a bit more.

Problem: with latest Graphviz, I have errors (or rather, warnings, as the final diagram is generated), both in the original graph and the one I wrote (by hand). Some searches shown this error was found in old versions and disappeared in more recent versions. Looks like it is back.

I still give the file, maybe it can be a starting point for somebody, or maybe it is enough for your needs (of course, you still have to generate it).

digraph tree
{
  rankdir=LR;

  DirTree [label="Directory Tree" shape=box]

  a_Foo_txt [shape=point]
  f_Foo_txt [label="Foo.txt", shape=none]
  a_Foo_txt -> f_Foo_txt

  a_Foo_Bar_html [shape=point]
  f_Foo_Bar_html [label="Foo Bar.html", shape=none]
  a_Foo_Bar_html -> f_Foo_Bar_html

  a_Bar_png [shape=point]
  f_Bar_png [label="Bar.png", shape=none]
  a_Bar_png -> f_Bar_png

  a_Some_Dir [shape=point]
  d_Some_Dir [label="Some Dir", shape=ellipse]
  a_Some_Dir -> d_Some_Dir

  a_VBE_C_reg [shape=point]
  f_VBE_C_reg [label="VBE_C.reg", shape=none]
  a_VBE_C_reg -> f_VBE_C_reg

  a_P_Folder [shape=point]
  d_P_Folder [label="P Folder", shape=ellipse]
  a_P_Folder -> d_P_Folder

  a_Processing_20081117_7z [shape=point]
  f_Processing_20081117_7z [label="Processing-20081117.7z", shape=none]
  a_Processing_20081117_7z -> f_Processing_20081117_7z

  a_UsefulBits_lua [shape=point]
  f_UsefulBits_lua [label="UsefulBits.lua", shape=none]
  a_UsefulBits_lua -> f_UsefulBits_lua

  a_Graphviz [shape=point]
  d_Graphviz [label="Graphviz", shape=ellipse]
  a_Graphviz -> d_Graphviz

  a_Tree_dot [shape=point]
  f_Tree_dot [label="Tree.dot", shape=none]
  a_Tree_dot -> f_Tree_dot

  {
    rank=same;
    DirTree -> a_Foo_txt -> a_Foo_Bar_html -> a_Bar_png -> a_Some_Dir -> a_Graphviz [arrowhead=none]
  }
  {
    rank=same;
    d_Some_Dir -> a_VBE_C_reg -> a_P_Folder -> a_UsefulBits_lua [arrowhead=none]
  }
  {
    rank=same;
    d_P_Folder -> a_Processing_20081117_7z [arrowhead=none]
  }
  {
    rank=same;
    d_Graphviz -> a_Tree_dot [arrowhead=none]
  }
}

> dot -Tpng Tree.dot -o Tree.png
Error: lost DirTree a_Foo_txt edge
Error: lost a_Foo_txt a_Foo_Bar_html edge
Error: lost a_Foo_Bar_html a_Bar_png edge
Error: lost a_Bar_png a_Some_Dir edge
Error: lost a_Some_Dir a_Graphviz edge
Error: lost d_Some_Dir a_VBE_C_reg edge
Error: lost a_VBE_C_reg a_P_Folder edge
Error: lost a_P_Folder a_UsefulBits_lua edge
Error: lost d_P_Folder a_Processing_20081117_7z edge
Error: lost d_Graphviz a_Tree_dot edge

I will try another direction, using Cairo, which is also able to export a number of formats. It is more work (computing positions/offsets) but the structure is simple, shouldn't be too hard.

use a javascript array to fill up a drop down select box

Use a for loop to iterate through your array. For each string, create a new option element, assign the string as its innerHTML and value, and then append it to the select element.

var cuisines = ["Chinese","Indian"];     
var sel = document.getElementById('CuisineList');
for(var i = 0; i < cuisines.length; i++) {
    var opt = document.createElement('option');
    opt.innerHTML = cuisines[i];
    opt.value = cuisines[i];
    sel.appendChild(opt);
}

DEMO

UPDATE: Using createDocumentFragment and forEach

If you have a very large list of elements that you want to append to a document, it can be non-performant to append each new element individually. The DocumentFragment acts as a light weight document object that can be used to collect elements. Once all your elements are ready, you can execute a single appendChild operation so that the DOM only updates once, instead of n times.

var cuisines = ["Chinese","Indian"];     

var sel = document.getElementById('CuisineList');
var fragment = document.createDocumentFragment();

cuisines.forEach(function(cuisine, index) {
    var opt = document.createElement('option');
    opt.innerHTML = cuisine;
    opt.value = cuisine;
    fragment.appendChild(opt);
});

sel.appendChild(fragment);

DEMO

Where do I configure log4j in a JUnit test class?

You may want to look into to Simple Logging Facade for Java (SLF4J). It is a facade that wraps around Log4j that doesn't require an initial setup call like Log4j. It is also fairly easy to switch out Log4j for Slf4j as the API differences are minimal.

How do I output coloured text to a Linux terminal?

You can use ANSI colour codes.

use these functions.

enum c_color{BLACK=30,RED=31,GREEN=32,YELLOW=33,BLUE=34,MAGENTA=35,CYAN=36,WHITE=37};
enum c_decoration{NORMAL=0,BOLD=1,FAINT=2,ITALIC=3,UNDERLINE=4,RIVERCED=26,FRAMED=51};
void pr(const string str,c_color color,c_decoration decoration=c_decoration::NORMAL){
  cout<<"\033["<<decoration<<";"<<color<<"m"<<str<<"\033[0m";
}

void prl(const string str,c_color color,c_decoration decoration=c_decoration::NORMAL){
   cout<<"\033["<<decoration<<";"<<color<<"m"<<str<<"\033[0m"<<endl;
}

Error Message: Type or namespace definition, or end-of-file expected

This line:

public  object Hours { get; set; }}

Your have a redundand } at the end

Implement a simple factory pattern with Spring 3 annotations

You are right, by creating object manually you are not letting Spring to perform autowiring. Consider managing your services by Spring as well:

@Component
public class MyServiceFactory {

    @Autowired
    private MyServiceOne myServiceOne;

    @Autowired
    private MyServiceTwo myServiceTwo;

    @Autowired
    private MyServiceThree myServiceThree;

    @Autowired
    private MyServiceDefault myServiceDefault;

    public static MyService getMyService(String service) {
        service = service.toLowerCase();

        if (service.equals("one")) {
            return myServiceOne;
        } else if (service.equals("two")) {
            return myServiceTwo;
        } else if (service.equals("three")) {
            return myServiceThree;
        } else {
            return myServiceDefault;
        }
    }
}

But I would consider the overall design to be rather poor. Wouldn't it better to have one general MyService implementation and pass one/two/three string as extra parameter to checkStatus()? What do you want to achieve?

@Component
public class MyServiceAdapter implements MyService {

    @Autowired
    private MyServiceOne myServiceOne;

    @Autowired
    private MyServiceTwo myServiceTwo;

    @Autowired
    private MyServiceThree myServiceThree;

    @Autowired
    private MyServiceDefault myServiceDefault;

    public boolean checkStatus(String service) {
        service = service.toLowerCase();

        if (service.equals("one")) {
            return myServiceOne.checkStatus();
        } else if (service.equals("two")) {
            return myServiceTwo.checkStatus();
        } else if (service.equals("three")) {
            return myServiceThree.checkStatus();
        } else {
            return myServiceDefault.checkStatus();
        }
    }
}

This is still poorly designed because adding new MyService implementation requires MyServiceAdapter modification as well (SRP violation). But this is actually a good starting point (hint: map and Strategy pattern).

PHP - syntax error, unexpected T_CONSTANT_ENCAPSED_STRING

When you're working with strings in PHP you'll need to pay special attention to the formation, using " or '

$string = 'Hello, world!';
$string = "Hello, world!";

Both of these are valid, the following is not:

$string = "Hello, world';

You must also note that ' inside of a literal started with " will not end the string, and vice versa. So when you have a string which contains ', it is generally best practice to use double quotation marks.

$string = "It's ok here";

Escaping the string is also an option

$string = 'It\'s ok here too';

More information on this can be found within the documentation

Spring RestTemplate - how to enable full debugging/logging of requests/responses?

Strangely, none of these solutions work as RestTemplate does not seem to return the response on some client and server 500x errors. In which case, you will have log those as well by implementing ResponseErrorHandler as follows. Here is a draft code, but you get the point:

You can set the same interceptor as the error handler:

restTemplate.getInterceptors().add(interceptor);
restTemplate.setRequestFactory(new BufferingClientHttpRequestFactory(new SimpleClientHttpRequestFactory()));
restTemplate.setErrorHandler(interceptor);

And the intercept implements both interfaces:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashSet;
import java.util.Set;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpRequest;
import org.springframework.http.HttpStatus.Series;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.web.client.DefaultResponseErrorHandler;
import org.springframework.web.client.ResponseErrorHandler;

public class LoggingRequestInterceptor implements ClientHttpRequestInterceptor, ResponseErrorHandler {
    static final Logger log = LoggerFactory.getLogger(LoggingRequestInterceptor.class);
    static final DefaultResponseErrorHandler defaultResponseErrorHandler = new DefaultResponseErrorHandler();
    final Set<Series> loggableStatuses = new HashSet();

    public LoggingRequestInterceptor() {
    }

    public LoggingRequestInterceptor(Set<Series> loggableStatuses) {
        loggableStatuses.addAll(loggableStatuses);
    }

    public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
        this.traceRequest(request, body);
        ClientHttpResponse response = execution.execute(request, body);
        if(response != null) {
            this.traceResponse(response);
        }

        return response;
    }

    private void traceRequest(HttpRequest request, byte[] body) throws IOException {
        log.debug("===========================request begin================================================");
        log.debug("URI         : {}", request.getURI());
        log.debug("Method      : {}", request.getMethod());
        log.debug("Headers     : {}", request.getHeaders());
        log.debug("Request body: {}", new String(body, "UTF-8"));
        log.debug("==========================request end================================================");
    }

    private void traceResponse(ClientHttpResponse response) throws IOException {
        if(this.loggableStatuses.isEmpty() || this.loggableStatuses.contains(response.getStatusCode().series())) {
            StringBuilder inputStringBuilder = new StringBuilder();

            try {
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(response.getBody(), "UTF-8"));

                for(String line = bufferedReader.readLine(); line != null; line = bufferedReader.readLine()) {
                    inputStringBuilder.append(line);
                    inputStringBuilder.append('\n');
                }
            } catch (Throwable var5) {
                log.error("cannot read response due to error", var5);
            }

            log.debug("============================response begin==========================================");
            log.debug("Status code  : {}", response.getStatusCode());
            log.debug("Status text  : {}", response.getStatusText());
            log.debug("Headers      : {}", response.getHeaders());
            log.debug("Response body: {}", inputStringBuilder.toString());
            log.debug("=======================response end=================================================");
        }

    }

    public boolean hasError(ClientHttpResponse response) throws IOException {
        return defaultResponseErrorHandler.hasError(response);
    }

    public void handleError(ClientHttpResponse response) throws IOException {
        this.traceResponse(response);
        defaultResponseErrorHandler.handleError(response);
    }
}

How to convert char* to wchar_t*?

In your example, wc is a local variable which will be deallocated when the function call ends. This puts you into undefined behavior territory.

The simple fix is this:

const wchar_t *GetWC(const char *c)
{
    const size_t cSize = strlen(c)+1;
    wchar_t* wc = new wchar_t[cSize];
    mbstowcs (wc, c, cSize);

    return wc;
}

Note that the calling code will then have to deallocate this memory, otherwise you will have a memory leak.

"Fatal error: Cannot redeclare <function>"

Another possible reason for getting that error is that your function has the same name as another PHP built-in function. For example,

function checkdate($date){
   $now=strtotime(date('Y-m-d H:i:s'));
   $tenYearsAgo=strtotime("-10 years", $now);
   $dateToCheck=strtotime($date);
   return ($tenYearsAgo > $dateToCheck) ? false : true;
}
echo checkdate('2016-05-12');

where the checkdate function already exists in PHP.

CSS set li indent

padding-left is what controls the indentation of ul not margin-left.

Compare: Here's setting padding-left to 0, notice all the indentation disappears.

_x000D_
_x000D_
ul {
  padding-left: 0;
}
_x000D_
<ul>
  <li>section a
    <ul>
      <li>one</li>
      <li>two</li>
      <li>three</li>
    </ul>
  </li>
</ul>
<ul>
  <li>section b
    <ul>
      <li>one</li>
      <li>two</li>
      <li>three</li>
    </ul>
  </li>
</ul>
_x000D_
_x000D_
_x000D_

and here's setting margin-left to 0px. Notice the indentation does NOT change.

_x000D_
_x000D_
ul {
  margin-left: 0;
}
_x000D_
<ul>
  <li>section a
    <ul>
      <li>one</li>
      <li>two</li>
      <li>three</li>
    </ul>
  </li>
</ul>
<ul>
  <li>section b
    <ul>
      <li>one</li>
      <li>two</li>
      <li>three</li>
    </ul>
  </li>
</ul>
_x000D_
_x000D_
_x000D_

Java: Check the date format of current string is according to required format or not

You can try this to simple date format valdation

 public Date validateDateFormat(String dateToValdate) {

    SimpleDateFormat formatter = new SimpleDateFormat("dd-MM-yyyy HHmmss");
    //To make strict date format validation
    formatter.setLenient(false);
    Date parsedDate = null;
    try {
        parsedDate = formatter.parse(dateToValdate);
        System.out.println("++validated DATE TIME ++"+formatter.format(parsedDate));

    } catch (ParseException e) {
        //Handle exception
    }
    return parsedDate;
}

how to save DOMPDF generated content to file?

I have just used dompdf and the code was a little different but it worked.

Here it is:

require_once("./pdf/dompdf_config.inc.php");
$files = glob("./pdf/include/*.php");
foreach($files as $file) include_once($file);

$html =
      '<html><body>'.
      '<p>Put your html here, or generate it with your favourite '.
      'templating system.</p>'.
      '</body></html>';

    $dompdf = new DOMPDF();
    $dompdf->load_html($html);
    $dompdf->render();
    $output = $dompdf->output();
    file_put_contents('Brochure.pdf', $output);

Only difference here is that all of the files in the include directory are included.

Other than that my only suggestion would be to specify a full directory path for writing the file rather than just the filename.

How to view the roles and permissions granted to any database user in Azure SQL server instance?

if you want to find about object name e.g. table name and stored procedure on which particular user has permission, use the following query:

SELECT pr.principal_id, pr.name, pr.type_desc, 
    pr.authentication_type_desc, pe.state_desc, pe.permission_name, OBJECT_NAME(major_id) objectName
FROM sys.database_principals AS pr
JOIN sys.database_permissions AS pe ON pe.grantee_principal_id = pr.principal_id
--INNER JOIN sys.schemas AS s ON s.principal_id =  sys.database_role_members.role_principal_id 
     where pr.name in ('youruser1','youruser2') 

How to deal with missing src/test/java source folder in Android/Maven project?

We can add java folder from

  1. Build Path -> Source.
  2. click on Add Folder.
  3. Select main as the container.
  4. click on Create Folder.
  5. Enter Folder name as java.
  6. Click on Finish

It works fine.

How to convert Varchar to Double in sql?

use DECIMAL() or NUMERIC() as they are fixed precision and scale numbers.

SELECT fullName, 
       CAST(totalBal as DECIMAL(9,2)) _totalBal
FROM client_info 
ORDER BY _totalBal DESC

Is this a good way to clone an object in ES6?

We can do that with two way:
1- First create a new object and replicate the structure of the existing one by iterating 
 over its properties and copying them on the primitive level.

let user = {
     name: "John",
     age: 30
    };

    let clone = {}; // the new empty object

    // let's copy all user properties into it
    for (let key in user) {
      clone[key] = user[key];
    }

    // now clone is a fully independant clone
    clone.name = "Pete"; // changed the data in it

    alert( user.name ); // still John in the original object

2- Second we can use the method Object.assign for that 
    let user = { name: "John" };
    let permissions1 = { canView: true };
    let permissions2 = { canEdit: true };

    // copies all properties from permissions1 and permissions2 into user
    Object.assign(user, permissions1, permissions2);

  -Another example

    let user = {
      name: "John",
      age: 30
    };

    let clone = Object.assign({}, user);
It copies all properties of user into the empty object and returns it. Actually, the same as the loop, but shorter.

But Object.assign() not create a deep clone

let user = {
  name: "John",
  sizes: {
    height: 182,
    width: 50
  }
};

let clone = Object.assign({}, user);

alert( user.sizes === clone.sizes ); // true, same object

// user and clone share sizes
user.sizes.width++;       // change a property from one place
alert(clone.sizes.width); // 51, see the result from the other one

To fix that, we should use the cloning loop that examines each value of user[key] and, if it’s an object, then replicate its structure as well. That is called a “deep cloning”.

There’s a standard algorithm for deep cloning that handles the case above and more complex cases, called the Structured cloning algorithm. In order not to reinvent the wheel, we can use a working implementation of it from the JavaScript library lodash the method is called _.cloneDeep(obj).

SET NOCOUNT ON usage

SET NOCOUNT ON; Above code will stop the message generated by sql server engine to fronted result window after the DML/DDL command execution.

Why we do it? As SQL server engine takes some resource to get the status and generate the message, it is considered as overload to the Sql server engine.So we set the noncount message on.

How to convert numbers between hexadecimal and decimal

If you want maximum performance when doing conversion from hex to decimal number, you can use the approach with pre-populated table of hex-to-decimal values.

Here is the code that illustrates that idea. My performance tests showed that it can be 20%-40% faster than Convert.ToInt32(...):

class TableConvert
  {
      static sbyte[] unhex_table =
      { -1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
       ,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
       ,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
       , 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,-1,-1,-1,-1,-1,-1
       ,-1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1
       ,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
       ,-1,10,11,12,13,14,15,-1,-1,-1,-1,-1,-1,-1,-1,-1
       ,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1
      };

      public static int Convert(string hexNumber)
      {
          int decValue = unhex_table[(byte)hexNumber[0]];
          for (int i = 1; i < hexNumber.Length; i++)
          {
              decValue *= 16;
              decValue += unhex_table[(byte)hexNumber[i]];
          }
          return decValue;
      }
  }

git discard all changes and pull from upstream

git reset <hash>  # you need to know the last good hash, so you can remove all your local commits

git fetch upstream
git checkout master
git merge upstream/master
git push origin master -f

voila, now your fork is back to same as upstream.

Download file through an ajax call php

@joe : Many thanks, this was a good heads up!

I had a slightly harder problem: 1. sending an AJAX request with POST data, for the server to produce a ZIP file 2. getting a response back 3. download the ZIP file

So that's how I did it (using JQuery to handle the AJAX request):

  1. Initial post request:

    var parameters = {
         pid     : "mypid",
       "files[]": ["file1.jpg","file2.jpg","file3.jpg"]
    }

    var options = { url: "request/url",//replace with your request url type: "POST",//replace with your request type data: parameters,//see above context: document.body,//replace with your contex success: function(data){ if (data) { if (data.path) { //Create an hidden iframe, with the 'src' attribute set to the created ZIP file. var dlif = $('<iframe/>',{'src':data.path}).hide(); //Append the iFrame to the context this.append(dlif); } else if (data.error) { alert(data.error); } else { alert('Something went wrong'); } } } }; $.ajax(options);

The "request/url" handles the zip creation (off topic, so I wont post the full code) and returns the following JSON object. Something like:

 //Code to create the zip file
 //......
 //Id of the file
 $zipid = "myzipfile.zip"
 //Download Link - it can be prettier
 $dlink = 'http://'.$_SERVER["SERVER_NAME"].'/request/download&file='.$zipid;
 //JSON response to be handled on the client side
 $result = '{"success":1,"path":"'.$dlink.'","error":null}';
 header('Content-type: application/json;');
 echo $result;

The "request/download" can perform some security checks, if needed, and generate the file transfer:

$fn = $_GET['file'];
if ($fn) {
  //Perform security checks
  //.....check user session/role/whatever
  $result = $_SERVER['DOCUMENT_ROOT'].'/path/to/file/'.$fn;
  if (file_exists($result)) {
    header('Content-Description: File Transfer');
    header('Content-Type: application/force-download');
    header('Content-Disposition: attachment; filename='.basename($result));
    header('Content-Transfer-Encoding: binary');
    header('Expires: 0');
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
    header('Pragma: public');
    header('Content-Length: ' . filesize($result));
    ob_clean();
    flush();
    readfile($result);
    @unlink($result);
  }

}

cast a List to a Collection

There have multiple solusions to convert list to a collection

Solution 1

List<Contact> CONTACTS = new ArrayList<String>();
// fill CONTACTS
Collection<Contact> c = CONTACTS;

Solution 2

private static final Collection<String> c = new ArrayList<String>(
                                                Arrays.asList("a", "b", "c"));

Solution 3

private static final Collection<Contact> = new ArrayList<Contact>(
                       Arrays.asList(new Contact("text1", "name1")
                                     new Contact("text2", "name2")));

Solution 4

List<? extends Contact> col = new ArrayList<Contact>(CONTACTS);

What is the best way to get the count/length/size of an iterator?

Your code will give you an exception when you reach the end of the iterator. You could do:

int i = 0;
while(iterator.hasNext()) {
    i++;
    iterator.next();
}

If you had access to the underlying collection, you would be able to call coll.size()...

EDIT OK you have amended...

What is the difference between the kernel space and the user space?

Each process has its own 4GB of virtual memory which maps to the physical memory through page tables. The virtual memory is mostly split in two parts: 3 GB for the use of the process and 1 GB for the use of the Kernel. Most of the variables you create lie in the first part of the address space. That part is called user space. The last part is where the kernel resides and is common for all the processes. This is called Kernel space and most of this space is mapped to the starting locations of physical memory where the kernel image is loaded at boot time.

calculate the mean for each column of a matrix in R

You can try this:

mean(as.matrix(cluster1))

Is there a way to programmatically minimize a window

in c#.net

this.WindowState = FormWindowState.Minimized

Converting a Java Keystore into PEM Format

I found a very interesting solution:

http://www.swview.org/node/191

Then, I divided the pair public/private key into two files private.key publi.pem and it works!

Convert String to Calendar Object in Java

Calendar cal = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("EEE MMM dd HH:mm:ss z yyyy", Locale.ENGLISH);
cal.setTime(sdf.parse("Mon Mar 14 16:02:37 GMT 2011"));// all done

note: set Locale according to your environment/requirement


See Also

How is using "<%=request.getContextPath()%>" better than "../"

request.getContextPath()- returns root path of your application, while ../ - returns parent directory of a file.

You use request.getContextPath(), as it will always points to root of your application. If you were to move your jsp file from one directory to another, nothing needs to be changed. Now, consider the second approach. If you were to move your jsp files from one folder to another, you'd have to make changes at every location where you are referring your files.

Also, better approach of using request.getContextPath() will be to set 'request.getContextPath()' in a variable and use that variable for referring your path.

<c:set var="context" value="${pageContext.request.contextPath}" />
<script src="${context}/themes/js/jquery.js"></script>

PS- This is the one reason I can figure out. Don't know if there is any more significance to it.

Generate Java class from JSON?

As far as I know there is no such tool. Yet.

The main reason is, I suspect, that unlike with XML (which has XML Schema, and then tools like 'xjc' to do what you ask, between XML and POJO definitions), there is no fully features schema language. There is JSON Schema, but it has very little support for actual type definitions (focuses on JSON structures), so it would be tricky to generate Java classes. But probably still possible, esp. if some naming conventions were defined and used to support generation.

However: this is something that has been fairly frequently requested (on mailing lists of JSON tool projects I follow), so I think that someone will write such a tool in near future.

So I don't think it is a bad idea per se (also: it is not a good idea for all use cases, depends on what you want to do ).

Why does typeof array with objects return "object" and not "array"?

Try this example and you will understand also what is the difference between Associative Array and Object in JavaScript.

Associative Array

var a = new Array(1,2,3); 
a['key'] = 'experiment';
Array.isArray(a);

returns true

Keep in mind that a.length will be undefined, because length is treated as a key, you should use Object.keys(a).length to get the length of an Associative Array.

Object

var a = {1:1, 2:2, 3:3,'key':'experiment'}; 
Array.isArray(a)

returns false

JSON returns an Object ... could return an Associative Array ... but it is not like that

Named tuple and default values for optional keyword arguments

I'm not sure if there's an easy way with just the built-in namedtuple. There's a nice module called recordtype that has this functionality:

>>> from recordtype import recordtype
>>> Node = recordtype('Node', [('val', None), ('left', None), ('right', None)])
>>> Node(3)
Node(val=3, left=None, right=None)
>>> Node(3, 'L')
Node(val=3, left=L, right=None)

Unable to read data from the transport connection : An existing connection was forcibly closed by the remote host

Another option would be to check the error code generated using try-catch block and first catching a WebException.

In my case, the error code was "SendFailure" because of certificate issue on HTTPS url, once I hit HTTP, that got resolved.

https://docs.microsoft.com/en-us/dotnet/api/system.net.webexceptionstatus?redirectedfrom=MSDN&view=netframework-4.8

White space showing up on right side of page when background image should extend full length of page

Apparently the (-o-min-device-pixel-ratio: 3/2) is causing problems. On my test site it was causing the right side to be cut off. I found a workaround on github that works for now. Using(-o-min-device-pixel-ratio: ~"3/2") seems to work fine.

Changing the Git remote 'push to' default

You can easily change default remote for branches all at once simple using this command

git push -u <remote_name> --all

Return the characters after Nth character in a string

Alternately, you could do a Text to Columns with space as the delimiter.

C error: undefined reference to function, but it IS defined

I think the problem is that when you're trying to compile testpoint.c, it includes point.h but it doesn't know about point.c. Since point.c has the definition for create, not having point.c will cause the compilation to fail.

I'm not familiar with MinGW, but you need to tell the compiler to look for point.c. For example with gcc you might do this:

gcc point.c testpoint.c

As others have pointed out, you also need to remove one of your main functions, since you can only have one.

Programmatically switching between tabs within Swift

If you want to do this from code that you are writing as part of a particular view controller, like in response to a button press or something, you can do this:

@IBAction func pushSearchButton(_ sender: UIButton?) {
    if let tabBarController = self.navigationController?.tabBarController  {
        tabBarController.selectedIndex = 1
    }
}

And you can also add code to handle tab switching using the UITabBarControllerDelegate methods. Using tags on the base view controllers of each tab, you can see where you are and act accordingly: For example

func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
    
    // if we didn't change tabs, don't do anything
    if tabBarController.selectedViewController?.tabBarItem.tag ==  viewController.tabBarItem.tag {
        return false
    }
    
    if viewController.tabBarItem.tag == 4096 { // some particular tab
        // do stuff appropriate for a transition to this particular tab
    }
    else if viewController.tabBarItem.tag == 2048 { // some other tab
        // do stuff appropriate for a transition to this other tab
    }
}

How do I seed a random class to avoid getting duplicate random values

A good seed generation for me is:

Random rand = new Random(Guid.NewGuid().GetHashCode());

It is very random. The seed is always different because the seed is also random generated.

Compare two DataFrames and output their differences side-by-side

If you found this thread trying to compare data fames in tests, then take a look at assert_frame_equal method: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.testing.assert_frame_equal.html

Put a Delay in Javascript

This thread has a good discussion and a useful solution:

function pause( iMilliseconds )
{
    var sDialogScript = 'window.setTimeout( function () { window.close(); }, ' + iMilliseconds + ');';
    window.showModalDialog('javascript:document.writeln ("<script>' + sDialogScript + '<' + '/script>")');
}

Unfortunately it appears that this doesn't work in some versions of IE, but the thread has many other worthy proposals if that proves to be a problem for you.

Using :before CSS pseudo element to add image to modal

You should use the background attribute to give an image to that element, and I would use ::after instead of before, this way it should be already drawn on top of your element.

.Modal:before{
  content: '';
  background:url('blackCarrot.png');
  width: /* width of the image */;
  height: /* height of the image */;
  display: block;
}

ORA-00942: table or view does not exist (works when a separate sql, but does not work inside a oracle function)

There's a strong chance that the privileges to select from table1 have been granted to a role, and the role has been granted to you. Privileges granted to a role are not available to PL/SQL written by a user, even if the user has been granted the role.

You see this a lot for users that have been granted the dba role on objects owned by sys. A user with dba role will be able to, say, SELECT * from V$SESSION, but will not be able to write a function that includes SELECT * FROM V$SESSION.

The fix is to grant explicit permissions on the object in question to the user directly, for example, in the case above, the SYS user has to GRANT SELECT ON V_$SESSION TO MyUser;

Is it possible to capture the stdout from the sh DSL command in the pipeline

A short version would be:

echo sh(script: 'ls -al', returnStdout: true).result

Get Maven artifact version at runtime

To get this running in Eclipse, as well as in a Maven build, you should add the addDefaultImplementationEntries and addDefaultSpecificationEntries pom entries as described in other replies, then use the following code:

public synchronized static final String getVersion() {
    // Try to get version number from pom.xml (available in Eclipse)
    try {
        String className = getClass().getName();
        String classfileName = "/" + className.replace('.', '/') + ".class";
        URL classfileResource = getClass().getResource(classfileName);
        if (classfileResource != null) {
            Path absolutePackagePath = Paths.get(classfileResource.toURI())
                    .getParent();
            int packagePathSegments = className.length()
                    - className.replace(".", "").length();
            // Remove package segments from path, plus two more levels
            // for "target/classes", which is the standard location for
            // classes in Eclipse.
            Path path = absolutePackagePath;
            for (int i = 0, segmentsToRemove = packagePathSegments + 2;
                    i < segmentsToRemove; i++) {
                path = path.getParent();
            }
            Path pom = path.resolve("pom.xml");
            try (InputStream is = Files.newInputStream(pom)) {
                Document doc = DocumentBuilderFactory.newInstance()
                        .newDocumentBuilder().parse(is);
                doc.getDocumentElement().normalize();
                String version = (String) XPathFactory.newInstance()
                        .newXPath().compile("/project/version")
                        .evaluate(doc, XPathConstants.STRING);
                if (version != null) {
                    version = version.trim();
                    if (!version.isEmpty()) {
                        return version;
                    }
                }
            }
        }
    } catch (Exception e) {
        // Ignore
    }

    // Try to get version number from maven properties in jar's META-INF
    try (InputStream is = getClass()
        .getResourceAsStream("/META-INF/maven/" + MAVEN_PACKAGE + "/"
                + MAVEN_ARTIFACT + "/pom.properties")) {
        if (is != null) {
            Properties p = new Properties();
            p.load(is);
            String version = p.getProperty("version", "").trim();
            if (!version.isEmpty()) {
                return version;
            }
        }
    } catch (Exception e) {
        // Ignore
    }

    // Fallback to using Java API to get version from MANIFEST.MF
    String version = null;
    Package pkg = getClass().getPackage();
    if (pkg != null) {
        version = pkg.getImplementationVersion();
        if (version == null) {
            version = pkg.getSpecificationVersion();
        }
    }
    version = version == null ? "" : version.trim();
    return version.isEmpty() ? "unknown" : version;
}

If your Java build puts target classes somewhere other than "target/classes", then you may need to adjust the value of segmentsToRemove.

Uninitialized Constant MessagesController

Your model is @Messages, change it to @message.

To change it like you should use migration:

def change   rename_table :old_table_name, :new_table_name end 

Of course do not create that file by hand but use rails generator:

rails g migration ChangeMessagesToMessage 

That will generate new file with proper timestamp in name in 'db dir. Then run:

rake db:migrate 

And your app should be fine since then.

Try-Catch-End Try in VBScript doesn't seem to work

Handling Errors

A sort of an "older style" of error handling is available to us in VBScript, that does make use of On Error Resume Next. First we enable that (often at the top of a file; but you may use it in place of the first Err.Clear below for their combined effect), then before running our possibly-error-generating code, clear any errors that have already occurred, run the possibly-error-generating code, and then explicitly check for errors:

On Error Resume Next
' ...
' Other Code Here (that may have raised an Error)
' ...
Err.Clear      ' Clear any possible Error that previous code raised
Set myObj = CreateObject("SomeKindOfClassThatDoesNotExist")
If Err.Number <> 0 Then
    WScript.Echo "Error: " & Err.Number
    WScript.Echo "Error (Hex): " & Hex(Err.Number)
    WScript.Echo "Source: " &  Err.Source
    WScript.Echo "Description: " &  Err.Description
    Err.Clear             ' Clear the Error
End If
On Error Goto 0           ' Don't resume on Error
WScript.Echo "This text will always print."

Above, we're just printing out the error if it occurred. If the error was fatal to the script, you could replace the second Err.clear with WScript.Quit(Err.Number).

Also note the On Error Goto 0 which turns off resuming execution at the next statement when an error occurs.

If you want to test behavior for when the Set succeeds, go ahead and comment that line out, or create an object that will succeed, such as vbscript.regexp.

The On Error directive only affects the current running scope (current Sub or Function) and does not affect calling or called scopes.


Raising Errors

If you want to check some sort of state and then raise an error to be handled by code that calls your function, you would use Err.Raise. Err.Raise takes up to five arguments, Number, Source, Description, HelpFile, and HelpContext. Using help files and contexts is beyond the scope of this text. Number is an error number you choose, Source is the name of your application/class/object/property that is raising the error, and Description is a short description of the error that occurred.

If MyValue <> 42 Then
    Err.Raise(42, "HitchhikerMatrix", "There is no spoon!")
End If

You could then handle the raised error as discussed above.


Change Log

  • Edit #1: Added an Err.Clear before the possibly error causing line to clear any previous errors that may have been ignored.
  • Edit #2: Clarified.
  • Edit #3: Added comments in code block. Clarified that there was expected to be more code between On Error Resume Next and Err.Clear. Fixed some grammar to be less awkward. Added info on Err.Raise. Formatting.
  • Is it possible to capture a Ctrl+C signal and run a cleanup function, in a "defer" fashion?

    Just for the record if somebody needs a way to handle signals on Windows. I had a requirement to handle from prog A calling prog B through os/exec but prog B never was able to terminate gracefully because sending signals through ex. cmd.Process.Signal(syscall.SIGTERM) or other signals are not supported on Windows. The way I handled is by creating a temp file as a signal ex. .signal.term through prog A and prog B needs to check if that file exists on interval base, if file exists it will exit the program and handle a cleanup if needed, I'm sure there are other ways but this did the job.

    If you can decode JWT, how are they secure?

    Only JWT's privateKey, which is on your server will decrypt the encrypted JWT. Those who know the privateKey will be able to decrypt the encrypted JWT.

    Hide the privateKey in a secure location in your server and never tell anyone the privateKey.

    Bootstrap 3 Navbar Collapse

    I had the same problem today.

    Bootstrap 4

    It's a native functionality: https://getbootstrap.com/docs/4.0/components/navbar/#responsive-behaviors

    You have to use .navbar-expand{-sm|-md|-lg|-xl} classes:

    <nav class="navbar navbar-expand-md navbar-light bg-light">
    

    Bootstrap 3

    @media (max-width: 991px) {
        .navbar-header {
            float: none;
        }
        .navbar-toggle {
            display: block;
        }
        .navbar-collapse {
            border-top: 1px solid transparent;
            box-shadow: inset 0 1px 0 rgba(255,255,255,0.1);
        }
        .navbar-collapse.collapse {
            display: none!important;
        }
        .navbar-nav {
            float: none!important;
            margin: 7.5px -15px;
        }
        .navbar-nav>li {
            float: none;
        }
        .navbar-nav>li>a {
            padding-top: 10px;
            padding-bottom: 10px;
        }
        .navbar-text {
            float: none;
            margin: 15px 0;
        }
        /* since 3.1.0 */
        .navbar-collapse.collapse.in { 
            display: block!important;
        }
        .collapsing {
            overflow: hidden!important;
        }
    }
    

    Just change 991px by 1199px for md sizes.

    Demo

    Updating a JSON object using Javascript

    A plain JavaScript solution, assuming jsonObj already contains JSON:

    Loop over it looking for the matching Id, set the corresponding Username, and break from the loop after the matched item has been modified:

    for (var i = 0; i < jsonObj.length; i++) {
      if (jsonObj[i].Id === 3) {
        jsonObj[i].Username = "Thomas";
        break;
      }
    }
    

    Here it is on jsFiddle.

    Here's the same thing wrapped in a function:

    function setUsername(id, newUsername) {
      for (var i = 0; i < jsonObj.length; i++) {
        if (jsonObj[i].Id === id) {
          jsonObj[i].Username = newUsername;
          return;
        }
      }
    }
    
    // Call as
    setUsername(3, "Thomas");
    

    How to permanently add a private key with ssh-add on Ubuntu?

    Adding the following lines in "~/.bashrc" solved the issue for me. I'm using Ubuntu 14.04 desktop.

    eval `gnome-keyring-daemon --start`
    USERNAME="reynold"
    export SSH_AUTH_SOCK="$(ls /run/user/$(id -u $USERNAME)/keyring*/ssh|head -1)"
    export SSH_AGENT_PID="$(pgrep gnome-keyring)"
    

    Split (explode) pandas dataframe string entry to separate rows

    I have been struggling with out-of-memory experience using various way to explode my lists so I prepared some benchmarks to help me decide which answers to upvote. I tested five scenarios with varying proportions of the list length to the number of lists. Sharing the results below:

    Time: (less is better, click to view large version)

    Speed

    Peak memory usage: (less is better)

    Peak memory usage

    Conclusions:

    • @MaxU's answer (update 2), codename concatenate offers the best speed in almost every case, while keeping the peek memory usage low,
    • see @DMulligan's answer (codename stack) if you need to process lots of rows with relatively small lists and can afford increased peak memory,
    • the accepted @Chang's answer works well for data frames that have a few rows but very large lists.

    Full details (functions and benchmarking code) are in this GitHub gist. Please note that the benchmark problem was simplified and did not include splitting of strings into the list - which most solutions performed in a similar fashion.

    C# How can I check if a URL exists/is valid?

    WebRequest request = WebRequest.Create("http://www.google.com");
    try
    {
         request.GetResponse();
    }
    catch //If exception thrown then couldn't get response from address
    {
         MessageBox.Show("The URL is incorrect");`
    }
    

    Is there a way to know your current username in mysql?

    Try the CURRENT_USER() function. This returns the username that MySQL used to authenticate your client connection. It is this username that determines your privileges.

    This may be different from the username that was sent to MySQL by the client (for example, MySQL might use an anonymous account to authenticate your client, even though you sent a username). If you want the username the client sent to MySQL when connecting use the USER() function instead.

    The value indicates the user name you specified when connecting to the server, and the client host from which you connected. The value can be different from that of CURRENT_USER().

    http://dev.mysql.com/doc/refman/5.0/en/information-functions.html#function_current-user

    Find where python is installed (if it isn't default dir)

    Have a look at sys.path:

    >>> import sys
    >>> print(sys.path)
    

    How to make Bootstrap Panel body with fixed height

    HTML :

    <div class="span4">
      <div class="panel panel-primary">
        <div class="panel-heading">jhdsahfjhdfhs</div>
        <div class="panel-body panel-height">fdoinfds sdofjohisdfj</div>
      </div>
    </div>
    

    CSS :

    .panel-height {
      height: 100px; / change according to your requirement/
    }
    

    How to write new line character to a file in Java

    bufferedWriter.write(text + "\n"); This method can work, but the new line character can be different between platforms, so alternatively, you can use this method:

    bufferedWriter.write(text);
    bufferedWriter.newline();
    

    Font Awesome not working, icons showing as squares

    Use this <i class="fa fa-camera-retro" ></i> you have not defined fa classes

    jQuery UI Datepicker - Multiple Date Selections

    http://t1m0n.name/air-datepicker/docs/? I've have tried several method of multi datepicker but only this works

    Tensorflow installation error: not a supported wheel on this platform

    Seems that tensorflow only work on python 3.5 at the moment, try to run this command before running the pip install

    conda create --name tensorflow python=3.5
    

    After this running the following lines :

    For cpu :

    pip install --ignore-installed --upgrade https://storage.googleapis.com/tensorflow/windows/cpu/tensorflow-1.1.0-cp35-cp35m-win_amd64.whl
    

    For gpu :

    pip install --ignore-installed --upgrade https://storage.googleapis.com/tensorflow/windows/gpu/tensorflow_gpu-1.1.0-cp35-cp35m-win_amd64.whl
    

    Should work like a charm,

    Cheers

    How to make a DIV always float on the screen in top right corner?

    Use position: fixed, and anchor it to the top and right sides of the page:

    #fixed-div {
        position: fixed;
        top: 1em;
        right: 1em;
    }
    

    IE6 does not support position: fixed, however. If you need this functionality in IE6, this purely-CSS solution seems to do the trick. You'll need a wrapper <div> to contain some of the styles for it to work, as seen in the stylesheet.

    Forwarding port 80 to 8080 using NGINX

    As simple as like this,

    make sure to change example.com to your domain (or IP), and 8080 to your Node.js application port:

    server {
        listen 80;
        server_name example.com;
    
        location / {
            proxy_set_header   X-Forwarded-For $remote_addr;
            proxy_set_header   Host $http_host;
            proxy_pass         "http://127.0.0.1:8080";
        }
    }
    

    Source: https://eladnava.com/binding-nodejs-port-80-using-nginx/

    How to change the colors of a PNG image easily?

    If you are going to be programming an application to do all of this, the process will be something like this:

    1. Convert image from RGB to HSV
    2. adjust H value
    3. Convert image back to RGB
    4. Save image

    How can I replace every occurrence of a String in a file with PowerShell?

    If You Need to Replace Strings in Multiple Files:

    It should be noted that the different methods posted here can be wildly different with regard to the time it takes to complete. For me, I regularly have large numbers of small files. To test what is most performant, I extracted 5.52 GB (5,933,604,999 bytes) of XML in 40,693 separate files and ran through three of the answers I found here:

    ## 5.52 GB (5,933,604,999 bytes) of XML files (40,693 files) 
    
    #### Test 1 - Plain Replace
    $start = get-date
    $xmls = (Get-ChildItem -Path "I:\TestseT\All_XML" -Recurse -Filter *.xml).FullName
    foreach ($xml in $xmls)
    {
    (Get-Content $xml).replace("'", " ") | Set-Content $xml
    }
    $end   = get-date
    NEW-TIMESPAN –Start $Start –End $End
    <#
    TotalMinutes: 103.725113128333
    #>
    
    #### Test 2 - Replace with -Raw
    $start = get-date
    $xmls = (Get-ChildItem -Path "I:\TestseT\All_XML" -Recurse -Filter *.xml).FullName
    foreach ($xml in $xmls)
    {
    (Get-Content $xml -Raw).replace("'", " ") | Set-Content $xml
    }
    $end   = get-date
    NEW-TIMESPAN –Start $Start –End $End
    <#
    TotalMinutes: 10.1600227983333
    #>
    
    #### Test 3 - .NET, System.IO
    $start = get-date
    $xmls = (Get-ChildItem -Path "I:\TestseT\All_XML" -Recurse -Filter *.xml).FullName
    foreach ($xml in $xmls)
    {
    $txt = [System.IO.File]::ReadAllText("$xml").Replace("'"," ") 
    [System.IO.File]::WriteAllText("$xml", $txt)
    }
    $end   = get-date
    NEW-TIMESPAN –Start $Start –End $End
    <#
    TotalMinutes: 5.83619516833333
    #>
    

    "Are you missing an assembly reference?" compile error - Visual Studio

    Are you strong-naming your assemblies? In that case it is not a good idea to auto-increment your build number because with every new build number you will also have to update all your references.

    clear data inside text file in c++

    If you simply open the file for writing with the truncate-option, you'll delete the content.

    std::ofstream ofs;
    ofs.open("test.txt", std::ofstream::out | std::ofstream::trunc);
    ofs.close();
    

    http://www.cplusplus.com/reference/fstream/ofstream/open/

    Create Test Class in IntelliJ

    Alternatively you could also position the cursor onto the class name and press alt+enter (Show intention actions and quick fixes). It will suggest to Create Test.

    At least works in IDEA version 12.

    Argument list too long error for rm, cp, mv commands

    Try this also If you wanna delete above 30/90 days (+) or else below 30/90(-) days files/folders then you can use the below ex commands

    Ex: For 90days excludes above after 90days files/folders deletes, it means 91,92....100 days

    find <path> -type f -mtime +90 -exec rm -rf {} \;
    

    Ex: For only latest 30days files that you wanna delete then use the below command (-)

    find <path> -type f -mtime -30 -exec rm -rf {} \;
    

    If you wanna giz the files for more than 2 days files

    find <path> -type f -mtime +2 -exec gzip {} \;
    

    If you wanna see the files/folders only from past one month . Ex:

    find <path> -type f -mtime -30 -exec ls -lrt {} \;
    

    Above 30days more only then list the files/folders Ex:

    find <path> -type f -mtime +30 -exec ls -lrt {} \;
    
    find /opt/app/logs -type f -mtime +30 -exec ls -lrt {} \;
    

    How to make g++ search for header files in a specific directory?

    Headers included with #include <> will be searched in all default directories , but you can also add your own location in the search path with -I command line arg.

    I saw your edit you could install your headers in default locations usually

     /usr/local/include
     libdir/gcc/target/version/include
     /usr/target/include
     /usr/include
    

    Confirm with compiler docs though.

    Submit form without reloading page

    You can use jQuery serialize function along with get/post as follows:

    $.get('server.php?' + $('#theForm').serialize())
    
    $.post('server.php', $('#theform').serialize())
    

    jQuery Serialize Documentation: http://api.jquery.com/serialize/

    Simple AJAX submit using jQuery:

    // this is the id of the submit button
    $("#submitButtonId").click(function() {
    
        var url = "path/to/your/script.php"; // the script where you handle the form input.
    
        $.ajax({
               type: "POST",
               url: url,
               data: $("#idForm").serialize(), // serializes the form's elements.
               success: function(data)
               {
                   alert(data); // show response from the php script.
               }
             });
    
        return false; // avoid to execute the actual submit of the form.
    });
    

    Constants in Objective-C

    If you like namespace constant, you can leverage struct, Friday Q&A 2011-08-19: Namespaced Constants and Functions

    // in the header
    extern const struct MANotifyingArrayNotificationsStruct
    {
        NSString *didAddObject;
        NSString *didChangeObject;
        NSString *didRemoveObject;
    } MANotifyingArrayNotifications;
    
    // in the implementation
    const struct MANotifyingArrayNotificationsStruct MANotifyingArrayNotifications = {
        .didAddObject = @"didAddObject",
        .didChangeObject = @"didChangeObject",
        .didRemoveObject = @"didRemoveObject"
    };
    

    Printing a 2D array in C

    First you need to input the two numbers say num_rows and num_columns perhaps using argc and argv then do a for loop to print the dots.

    int j=0;
    int k=0;
    for (k=0;k<num_columns;k++){
       for (j=0;j<num_rows;j++){
           printf(".");
       }
     printf("\n");
     }
    

    you'd have to replace the dot with something else later.

    How to get text in QlineEdit when QpushButton is pressed in a string?

    My first suggestion is to use Designer to create your GUIs. Typing them out yourself sucks, takes more time, and you will definitely make more mistakes than Designer.

    Here are some PyQt tutorials to help get you on the right track. The first one in the list is where you should start.

    A good guide for figuring out what methods are available for specific classes is the PyQt4 Class Reference. In this case you would look up QLineEdit and see the there is a text method.

    To answer your specific question:

    To make your GUI elements available to the rest of the object, preface them with self.

    import sys
    from PyQt4.QtCore import SIGNAL
    from PyQt4.QtGui import QDialog, QApplication, QPushButton, QLineEdit, QFormLayout
    
    class Form(QDialog):
        def __init__(self, parent=None):
            super(Form, self).__init__(parent)
    
            self.le = QLineEdit()
            self.le.setObjectName("host")
            self.le.setText("Host")
    
            self.pb = QPushButton()
            self.pb.setObjectName("connect")
            self.pb.setText("Connect") 
    
            layout = QFormLayout()
            layout.addWidget(self.le)
            layout.addWidget(self.pb)
    
            self.setLayout(layout)
            self.connect(self.pb, SIGNAL("clicked()"),self.button_click)
            self.setWindowTitle("Learning")
    
        def button_click(self):
            # shost is a QString object
            shost = self.le.text()
            print shost
    
    
    app = QApplication(sys.argv)
    form = Form()
    form.show()
    app.exec_()
    

    How to find whether a ResultSet is empty or not in Java?

    if (rs == null || !rs.first()) {
        //empty
    } else {
        //not empty
    }
    

    Note that after this method call, if the resultset is not empty, it is at the beginning.

    PHP equivalent of .NET/Java's toString()

    Use print_r:

    $myText = print_r($myVar,true);
    

    You can also use it like:

    $myText = print_r($myVar,true)."foo bar";
    

    This will set $myText to a string, like:

    array (
      0 => '11',
    )foo bar
    

    Use var_export to get a little bit more info (with types of variable,...):

    $myText = var_export($myVar,true);
    

    How to configure Chrome's Java plugin so it uses an existing JDK in the machine

    Starting with Version 42, released April 14, 2015, Chrome blocks all NPAPI plugins, including Java. Until September 2015 there will be a way around this, by going to chrome://flags/#enable-npapi and clicking on Enable. After that, you will have to use the IE tab extension to run the Direct-X version of the Java plugin.

    jQuery - Trigger event when an element is removed from the DOM

    I couldn't get this answer to work with unbinding (despite the update see here), but was able to figure out a way around it. The answer was to create a 'destroy_proxy' special event that triggered a 'destroyed' event. You put the event listener on both 'destroyed_proxy' and 'destroyed', then when you want to unbind, you just unbind the 'destroyed' event:

    var count = 1;
    (function ($) {
        $.event.special.destroyed_proxy = {
            remove: function (o) {
                $(this).trigger('destroyed');
            }
        }
    })(jQuery)
    
    $('.remove').on('click', function () {
        $(this).parent().remove();
    });
    
    $('li').on('destroyed_proxy destroyed', function () {
        console.log('Element removed');
        if (count > 2) {
            $('li').off('destroyed');
            console.log('unbinded');
        }
        count++;
    });
    

    Here is a fiddle

    How do I run a simple bit of code in a new thread?

    another option, that uses delegates and the Thread Pool...

    assuming 'GetEnergyUsage' is a method that takes a DateTime and another DateTime as input arguments, and returns an Int...

    // following declaration of delegate ,,,
    public delegate long GetEnergyUsageDelegate(DateTime lastRunTime, 
                                                DateTime procDateTime);
    
    // following inside of some client method 
    GetEnergyUsageDelegate nrgDel = GetEnergyUsage;                     
    IAsyncResult aR = nrgDel.BeginInvoke(lastRunTime, procDT, null, null);
    while (!aR.IsCompleted) Thread.Sleep(500);
    int usageCnt = nrgDel.EndInvoke(aR);
    

    How do I make a Mac Terminal pop-up/alert? Applescript?

    This would restore focus to the previous application and exit the script if the answer was empty.

    a=$(osascript -e 'try
    tell app "SystemUIServer"
    set answer to text returned of (display dialog "" default answer "")
    end
    end
    activate app (path to frontmost application as text)
    answer' | tr '\r' ' ')
    [[ -z "$a" ]] && exit
    

    If you told System Events to display the dialog, there would be a small delay if it wasn't running before.

    For documentation about display dialog, open the dictionary of Standard Additions in AppleScript Editor or see the AppleScript Language Guide.

    JavaScript Array to Set

    By definition "A Set is a collection of values, where each value may occur only once." So, if your array has repeated values then only one value among the repeated values will be added to your Set.

    var arr = [1, 2, 3];
    var set = new Set(arr);
    console.log(set); // {1,2,3}
    
    
    var arr = [1, 2, 1];
    var set = new Set(arr);
    console.log(set); // {1,2}
    

    So, do not convert to set if you have repeated values in your array.

    Meaning of numbers in "col-md-4"," col-xs-1", "col-lg-2" in Bootstrap

    From Twitter Bootstrap documentation:

    • small grid (= 768px) = .col-sm-*,
    • medium grid (= 992px) = .col-md-*,
    • large grid (= 1200px) = .col-lg-*.

    to Read More...

    View content of H2 or HSQLDB in-memory database

    This is a Play 2 controller to initialize the H2 TCP and Web servers:

    package controllers;
    
    import org.h2.tools.Server;
    import play.mvc.Controller;
    import play.mvc.Result;
    
    import java.sql.SQLException;
    
    /**
     * Play 2 controller to initialize H2 TCP Server and H2 Web Console Server.
     *
     * Once it's initialized, you can connect with a JDBC client with
     * the URL `jdbc:h2:tcp://127.0.1.1:9092/mem:DBNAME`,
     * or can be accessed with the web console at `http://localhost:8082`,
     * and the URL JDBC `jdbc:h2:mem:DBNAME`.
     *
     * @author Mariano Ruiz <[email protected]>
     */
    public class H2ServerController extends Controller {
    
        private static Server h2Server = null;
        private static Server h2WebServer = null;
    
        public static synchronized Result debugH2() throws SQLException {
            if (h2Server == null) {
                h2Server = Server.createTcpServer("-tcp", "-tcpAllowOthers", "-tcpPort", "9092");
                h2Server.start();
                h2WebServer = Server.createWebServer("-web","-webAllowOthers","-webPort","8082");
                h2WebServer.start();
                return ok("H2 TCP/Web servers initialized");
            } else {
                return ok("H2 TCP/Web servers already initialized");
            }
        }
    }
    

    How to print the full NumPy array, without truncation?

    numpy.savetxt

    numpy.savetxt(sys.stdout, numpy.arange(10000))
    

    or if you need a string:

    import StringIO
    sio = StringIO.StringIO()
    numpy.savetxt(sio, numpy.arange(10000))
    s = sio.getvalue()
    print s
    

    The default output format is:

    0.000000000000000000e+00
    1.000000000000000000e+00
    2.000000000000000000e+00
    3.000000000000000000e+00
    ...
    

    and it can be configured with further arguments.

    Note in particular how this also not shows the square brackets, and allows for a lot of customization, as mentioned at: How to print a Numpy array without brackets?

    Tested on Python 2.7.12, numpy 1.11.1.

    How can I get the IP address from NIC in Python?

    A simple approach which returns a string with ip-addresses for the interfaces is:

    from subprocess import check_output
    
    ips = check_output(['hostname', '--all-ip-addresses'])
    

    for more info see hostname.

    Can you delete data from influxdb?

    I'm surprised that nobody has mentioned InfluxDB retention policies for automatic data removal. You can set a default retention policy and also set them on a per-database level.

    From the docs:

    CREATE RETENTION POLICY <retention_policy_name> ON <database_name> DURATION <duration> REPLICATION <n> [DEFAULT]
    

    Can you get a Windows (AD) username in PHP?

    get_user_name works the same way as getenv('USERNAME');

    I had encoding(with cyrillic) problems using getenv('USERNAME')

    Error inflating class android.support.v7.widget.Toolbar?

    I had issues including toolbar in a RelativeLayout, try with LinearLayout. If you want to overlay the toolbar, try with:

     <RelativeLayout>
    
        <LinearLayout>
          --INCLUDE tOOLBAR--
        </LinearLayout>
    
        <Button></Button>
    
     </RelativeLayout>
    

    I don't understand why but it works for me.

    Daemon Threads Explanation

    A simpler way to think about it, perhaps: when main returns, your process will not exit if there are non-daemon threads still running.

    A bit of advice: Clean shutdown is easy to get wrong when threads and synchronization are involved - if you can avoid it, do so. Use daemon threads whenever possible.

    SQL multiple columns in IN clause

    Ensure you have an index on your firstname and lastname columns and go with 1. This really won't have much of a performance impact at all.

    EDIT: After @Dems comment regarding spamming the plan cache ,a better solution might be to create a computed column on the existing table (or a separate view) which contained a concatenated Firstname + Lastname value, thus allowing you to execute a query such as

    SELECT City 
    FROM User 
    WHERE Fullname in (@fullnames)
    

    where @fullnames looks a bit like "'JonDoe', 'JaneDoe'" etc

    How to write a comment in a Razor view?

    This comment syntax should work for you:

    @* enter comments here *@
    

    Java string split with "." (dot)

    The dot "." is a special character in java regex engine, so you have to use "\\." to escape this character:

    final String extensionRemoved = filename.split("\\.")[0];
    

    I hope this helps

    Safe navigation operator (?.) or (!.) and null property paths

    Another alternative that uses an external library is _.has() from Lodash.

    E.g.

    _.has(a, 'b.c')
    

    is equal to

    (a && a.b && a.b.c)
    

    EDIT: As noted in the comments, you lose out on Typescript's type inference when using this method. E.g. Assuming that one's objects are properly typed, one would get a compilation error with (a && a.b && a.b.z) if z is not defined as a field of object b. But using _.has(a, 'b.z'), one would not get that error.

    Run jQuery function onclick

    Using obtrusive JavaScript (i.e. inline code) as in your example, you can attach the click event handler to the div element with the onclick attribute like so:

     <div id="some-id" class="some-class" onclick="slideonlyone('sms_box');">
         ...
     </div>
    

    However, the best practice is unobtrusive JavaScript which you can easily achieve by using jQuery's on() method or its shorthand click(). For example:

     $(document).ready( function() {
         $('.some-class').on('click', slideonlyone('sms_box'));
         // OR //
         $('.some-class').click(slideonlyone('sms_box'));
     });
    

    Inside your handler function (e.g. slideonlyone() in this case) you can reference the element that triggered the event (e.g. the div in this case) with the $(this) object. For example, if you need its ID, you can access it with $(this).attr('id').


    EDIT

    After reading your comment to @fmsf below, I see you also need to dynamically reference the target element to be toggled. As @fmsf suggests, you can add this information to the div with a data-attribute like so:

    <div id="some-id" class="some-class" data-target="sms_box">
        ...
    </div>
    

    To access the element's data-attribute you can use the attr() method as in @fmsf's example, but the best practice is to use jQuery's data() method like so:

     function slideonlyone() {
         var trigger_id = $(this).attr('id'); // This would be 'some-id' in our example
         var target_id  = $(this).data('target'); // This would be 'sms_box'
         ...
     }
    

    Note how data-target is accessed with data('target'), without the data- prefix. Using data-attributes you can attach all sorts of information to an element and jQuery would automatically add them to the element's data object.

    PHP reindex array?

    Use array_values.

    $myarray = array_values($myarray);
    

    How to change a DIV padding without affecting the width/height ?

    To achieve a consistent result cross browser, you would usually add another div inside the div and give that no explicit width, and a margin. The margin will simulate padding for the outer div.

    Excel: How to check if a cell is empty with VBA?

    You could use IsEmpty() function like this:

    ...
    Set rRng = Sheet1.Range("A10")
    If IsEmpty(rRng.Value) Then ...
    

    you could also use following:

    If ActiveCell.Value = vbNullString Then ...
    

    Populate unique values into a VBA array from Excel

    This VBA function returns an array of distinct values when passed either a range or a 2D array source

    It defaults to processing the first column of the source, but you can optionally choose another column.

    I wrote a LinkedIn article about it.

    Function DistinctVals(a, Optional col = 1)
        Dim i&, v: v = a
        With CreateObject("Scripting.Dictionary")
            For i = 1 To UBound(v): .Item(v(i, col)) = 1: Next
            DistinctVals = Application.Transpose(.Keys)
        End With
    End Function
    

    Calculate RSA key fingerprint

    To check a remote SSH server prior to the first connection, you can give a look at www.server-stats.net/ssh/ to see all SHH keys for the server, as well as from when the key is known.

    That's not like an SSL certificate, but definitely a must-do before connecting to any SSH server for the first time.

    How to go to a URL using jQuery?

    Actually, you have to use the anchor # to play with this. If you reverse engineer the Gmail url system, you'll find

    https://mail.google.com/mail/u/0/#inbox
    https://mail.google.com/mail/u/0/#inbox?compose=new
    

    Everything after # is the part your want to load in your page, then you just have to chose where to load it.

    By the way, using document.location by adding a #something won't refresh your page.

    What key shortcuts are to comment and uncomment code?

    "commentLine" is the name of function you are looking for. This function coment and uncoment with the same keybinding

    Change the color of cells in one column when they don't match cells in another column

    In my case I had to compare column E and I.

    I used conditional formatting with new rule. Formula was "=IF($E1<>$I1,1,0)" for highlights in orange and "=IF($E1=$I1,1,0)" to highlight in green.

    Next problem is how many columns you want to highlight. If you open Conditional Formatting Rules Manager you can edit for each rule domain of applicability: Check "Applies to"

    In my case I used "=$E:$E,$I:$I" for both rules so I highlight only two columns for differences - column I and column E.

    Zoom in on a point (using scale and translate)

    I want to put here some information for those, who do separately drawing of picture and moving -zooming it.

    This may be useful when you want to store zooms and position of viewport.

    Here is drawer:

    function redraw_ctx(){
       self.ctx.clearRect(0,0,canvas_width, canvas_height)
       self.ctx.save()
       self.ctx.scale(self.data.zoom, self.data.zoom) // 
       self.ctx.translate(self.data.position.left, self.data.position.top) // position second
       // Here We draw useful scene My task - image:
       self.ctx.drawImage(self.img ,0,0) // position 0,0 - we already prepared
       self.ctx.restore(); // Restore!!!
    }
    

    Notice scale MUST be first.

    And here is zoomer:

    function zoom(zf, px, py){
        // zf - is a zoom factor, which in my case was one of (0.1, -0.1)
        // px, py coordinates - is point within canvas 
        // eg. px = evt.clientX - canvas.offset().left
        // py = evt.clientY - canvas.offset().top
        var z = self.data.zoom;
        var x = self.data.position.left;
        var y = self.data.position.top;
    
        var nz = z + zf; // getting new zoom
        var K = (z*z + z*zf) // putting some magic
    
        var nx = x - ( (px*zf) / K ); 
        var ny = y - ( (py*zf) / K);
    
        self.data.position.left = nx; // renew positions
        self.data.position.top = ny;   
        self.data.zoom = nz; // ... and zoom
        self.redraw_ctx(); // redraw context
        }
    

    and, of course, we would need a dragger:

    this.my_cont.mousemove(function(evt){
        if (is_drag){
            var cur_pos = {x: evt.clientX - off.left,
                           y: evt.clientY - off.top}
            var diff = {x: cur_pos.x - old_pos.x,
                        y: cur_pos.y - old_pos.y}
    
            self.data.position.left += (diff.x / self.data.zoom);  // we want to move the point of cursor strictly
            self.data.position.top += (diff.y / self.data.zoom);
    
            old_pos = cur_pos;
            self.redraw_ctx();
    
        }
    
    
    })
    

    How to get a Static property with Reflection

    The below seems to work for me.

    using System;
    using System.Reflection;
    
    public class ReflectStatic
    {
        private static int SomeNumber {get; set;}
        public static object SomeReference {get; set;}
        static ReflectStatic()
        {
            SomeReference = new object();
            Console.WriteLine(SomeReference.GetHashCode());
        }
    }
    
    public class Program
    {
        public static void Main()
        {
            var rs = new ReflectStatic();
            var pi = rs.GetType().GetProperty("SomeReference",  BindingFlags.Static | BindingFlags.Public);
            if(pi == null) { Console.WriteLine("Null!"); Environment.Exit(0);}
            Console.WriteLine(pi.GetValue(rs, null).GetHashCode());
    
    
        }
    }