Programs & Examples On #Duplex channel

CSS3 Rotate Animation

I have a rotating image using the same thing as you:

.knoop1 img{
    position:absolute;
    width:114px;
    height:114px;
    top:400px;
    margin:0 auto;
    margin-left:-195px;
    z-index:0;

    -webkit-transition-duration: 0.8s;
    -moz-transition-duration: 0.8s;
    -o-transition-duration: 0.8s;
    transition-duration: 0.8s;

    -webkit-transition-property: -webkit-transform;
    -moz-transition-property: -moz-transform;
    -o-transition-property: -o-transform;
     transition-property: transform;

     overflow:hidden;
}

.knoop1:hover img{
    -webkit-transform:rotate(360deg);
    -moz-transform:rotate(360deg); 
    -o-transform:rotate(360deg);
}

what is difference between success and .done() method of $.ajax

success only fires if the AJAX call is successful, i.e. ultimately returns a HTTP 200 status. error fires if it fails and complete when the request finishes, regardless of success.

In jQuery 1.8 on the jqXHR object (returned by $.ajax) success was replaced with done, error with fail and complete with always.

However you should still be able to initialise the AJAX request with the old syntax. So these do similar things:

// set success action before making the request
$.ajax({
  url: '...',
  success: function(){
    alert('AJAX successful');
  }
});

// set success action just after starting the request
var jqxhr = $.ajax( "..." )
  .done(function() { alert("success"); });

This change is for compatibility with jQuery 1.5's deferred object. Deferred (and now Promise, which has full native browser support in Chrome and FX) allow you to chain asynchronous actions:

$.ajax("parent").
    done(function(p) { return $.ajax("child/" + p.id); }).
    done(someOtherDeferredFunction).
    done(function(c) { alert("success: " + c.name); });

This chain of functions is easier to maintain than a nested pyramid of callbacks you get with success.

However, please note that done is now deprecated in favour of the Promise syntax that uses then instead:

$.ajax("parent").
    then(function(p) { return $.ajax("child/" + p.id); }).
    then(someOtherDeferredFunction).
    then(function(c) { alert("success: " + c.name); }).
    catch(function(err) { alert("error: " + err.message); });

This is worth adopting because async and await extend promises improved syntax (and error handling):

try {
    var p = await $.ajax("parent");
    var x = await $.ajax("child/" + p.id);
    var c = await someOtherDeferredFunction(x);
    alert("success: " + c.name);
}
catch(err) { 
    alert("error: " + err.message); 
}

PHP header redirect 301 - what are the implications?

Just a tip: using http_response_code is much easier to remember than writing the full header:

http_response_code(301);
header('Location: /option-a'); 
exit;

chrome : how to turn off user agent stylesheet settings?

https://developers.google.com/chrome-developer-tools/docs/settings

  1. Open Chrome dev tools
  2. Click gear icon on bottom right
  3. In General section, check or uncheck "Show user agent styles".

Error during SSL Handshake with remote server

I have 2 servers setup on docker, reverse proxy & web server. This error started happening for all my websites all of a sudden after 1 year. When setting up earlier, I generated a self signed certificate on the web server.

So, I had to generate the SSL certificate again and it started working...

openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ssl.key -out ssl.crt

Javascript extends class

   extend = function(destination, source) {   
          for (var property in source) {
            destination[property] = source[property];
          }
          return destination;
    };

Extending JavaScript

You could also add filters into the for loop.

Content Security Policy: The page's settings blocked the loading of a resource

I had a similar error type. First, I tried to add the meta tags in the code, but it didn't work.

I found out that on the nginx web server you may have a security setting that may block external code to run:

# Security directives
server_tokens off;
add_header X-Frame-Options SAMEORIGIN;
add_header X-Content-Type-Options nosniff;
add_header X-XSS-Protection "1; mode=block";
add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'  https://ajax.googleapis.com  https://ssl.google-analytics.com https://assets.zendesk.com https://connect.facebook.net; img-src 'self' https://ssl.google-analytics.com https://s-static.ak.facebook.com https://assets.zendesk.com; style-src 'self' 'unsafe-inline' https://assets.zendesk.com; font-src 'self' https://fonts.gstatic.com  https://themes.googleusercontent.com; frame-src https://player.vimeo.com https://assets.zendesk.com https://www.facebook.com https://s-static.ak.facebook.com https://tautt.zendesk.com; object-src 'none'";

Check the Content-Security-Policy. You may need to add the source reference.

How to select distinct rows in a datatable and store into an array

DataTable dt = new DataTable();
dt.Columns.Add("IntValue", typeof(int));
dt.Columns.Add("StringValue", typeof(string));
dt.Rows.Add(1, "1");
dt.Rows.Add(1, "1");
dt.Rows.Add(1, "1");
dt.Rows.Add(2, "2");
dt.Rows.Add(2, "2");

var x = (from r in dt.AsEnumerable()
        select r["IntValue"]).Distinct().ToList();

Flask SQLAlchemy query, specify column names

You can use Model.query, because the Model (or usually its base class, especially in cases where declarative extension is used) is assigned Sesssion.query_property. In this case the Model.query is equivalent to Session.query(Model).

I am not aware of the way to modify the columns returned by the query (except by adding more using add_columns()).
So your best shot is to use the Session.query(Model.col1, Model.col2, ...) (as already shown by Salil).

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

Here is a shorter bit of code that reenables scroll bars across your entire website. I'm not sure if it's much different than the current most popular answer but here it is:

::-webkit-scrollbar {
    -webkit-appearance: none;
    width: 7px;
}
::-webkit-scrollbar-thumb {
    border-radius: 4px;
    background-color: rgba(0,0,0,.5);
    box-shadow: 0 0 1px rgba(255,255,255,.5);
}

Found at this link: http://simurai.com/blog/2011/07/26/webkit-scrollbar

Check if string doesn't contain another string

Use this as your WHERE condition

WHERE CHARINDEX('Apples', column) = 0 

What characters are forbidden in Windows and Linux directory names?

For anyone looking for a regex:

const BLACKLIST = /[<>:"\/\\|?*]/g;

How do I get rid of an element's offset using CSS?

You can apply a reset css to get rid of those 'defaults'. Here is an example of a reset css http://meyerweb.com/eric/tools/css/reset/ . Just apply the reset styles BEFORE your own styles.

Count all duplicates of each value

If you want to check repetition more than 1 in descending order then implement below query.

SELECT   duplicate_data,COUNT(duplicate_data) AS duplicate_data
FROM     duplicate_data_table_name 
GROUP BY duplicate_data
HAVING   COUNT(duplicate_data) > 1
ORDER BY COUNT(duplicate_data) DESC

If want simple count query.

SELECT   COUNT(duplicate_data) AS duplicate_data
FROM     duplicate_data_table_name 
GROUP BY duplicate_data
ORDER BY COUNT(duplicate_data) DESC

How to add multiple classes to a ReactJS Component?

I know this is a late answer, but I hope this will help someone.

Consider that you have defined following classes in a css file 'primary', 'font-i', 'font-xl'

  • The first step would be to import the CSS file.
  • Then

_x000D_
_x000D_
<h3 class = {` ${'primary'} ${'font-i'} font-xl`}> HELLO WORLD </h3>
_x000D_
_x000D_
_x000D_

would do the trick!

For more info: https://www.youtube.com/watch?v=j5P9FHiBVNo&list=PLC3y8-rFHvwgg3vaYJgHGnModB54rxOk3&index=20

How can I loop through all rows of a table? (MySQL)

Since the suggestion of a loop implies the request for a procedure type solution. Here is mine.

Any query which works on any single record taken from a table can be wrapped in a procedure to make it run through each row of a table like so:

First delete any existing procedure with the same name, and change the delimiter so your SQL doesn't try to run each line as you're trying to write the procedure.

DROP PROCEDURE IF EXISTS ROWPERROW;
DELIMITER ;;

Then here's the procedure as per your example (table_A and table_B used for clarity)

CREATE PROCEDURE ROWPERROW()
BEGIN
DECLARE n INT DEFAULT 0;
DECLARE i INT DEFAULT 0;
SELECT COUNT(*) FROM table_A INTO n;
SET i=0;
WHILE i<n DO 
  INSERT INTO table_B(ID, VAL) SELECT (ID, VAL) FROM table_A LIMIT i,1;
  SET i = i + 1;
END WHILE;
End;
;;

Then dont forget to reset the delimiter

DELIMITER ;

And run the new procedure

CALL ROWPERROW();

You can do whatever you like at the "INSERT INTO" line which I simply copied from your example request.

Note CAREFULLY that the "INSERT INTO" line used here mirrors the line in the question. As per the comments to this answer you need to ensure that your query is syntactically correct for which ever version of SQL you are running.

In the simple case where your ID field is incremented and starts at 1 the line in the example could become:

INSERT INTO table_B(ID, VAL) VALUES(ID, VAL) FROM table_A WHERE ID=i;

Replacing the "SELECT COUNT" line with

SET n=10;

Will let you test your query on the first 10 record in table_A only.

One last thing. This process is also very easy to nest across different tables and was the only way I could carry out a process on one table which dynamically inserted different numbers of records into a new table from each row of a parent table.

If you need it to run faster then sure try to make it set based, if not then this is fine. You could also rewrite the above in cursor form but it may not improve performance. eg:

DROP PROCEDURE IF EXISTS cursor_ROWPERROW;
DELIMITER ;;

CREATE PROCEDURE cursor_ROWPERROW()
BEGIN
  DECLARE cursor_ID INT;
  DECLARE cursor_VAL VARCHAR;
  DECLARE done INT DEFAULT FALSE;
  DECLARE cursor_i CURSOR FOR SELECT ID,VAL FROM table_A;
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;
  OPEN cursor_i;
  read_loop: LOOP
    FETCH cursor_i INTO cursor_ID, cursor_VAL;
    IF done THEN
      LEAVE read_loop;
    END IF;
    INSERT INTO table_B(ID, VAL) VALUES(cursor_ID, cursor_VAL);
  END LOOP;
  CLOSE cursor_i;
END;
;;

Remember to declare the variables you will use as the same type as those from the queried tables.

My advise is to go with setbased queries when you can, and only use simple loops or cursors if you have to.

How to combine two byte arrays

I've used this code which works quite well just do appendData and either pass a single byte with an array, or two arrays to combine them :

protected byte[] appendData(byte firstObject,byte[] secondObject){
    byte[] byteArray= {firstObject};
    return appendData(byteArray,secondObject);
}

protected byte[] appendData(byte[] firstObject,byte secondByte){
    byte[] byteArray= {secondByte};
    return appendData(firstObject,byteArray);
}

protected byte[] appendData(byte[] firstObject,byte[] secondObject){
    ByteArrayOutputStream outputStream = new ByteArrayOutputStream( );
    try {
        if (firstObject!=null && firstObject.length!=0)
            outputStream.write(firstObject);
        if (secondObject!=null && secondObject.length!=0)   
            outputStream.write(secondObject);
    } catch (IOException e) {
        e.printStackTrace();
    }
    return outputStream.toByteArray();
}

Redirect from a view to another view

It's because your statement does not produce output.

Besides all the warnings of Darin and lazy (they are right); the question still offerst something to learn.

If you want to execute methods that don't directly produce output, you do:

@{ Response.Redirect("~/Account/LogIn?returnUrl=Products");}

This is also true for rendering partials like:

@{ Html.RenderPartial("_MyPartial"); }

Set variable in jinja

Just Set it up like this

{% set active_link = recordtype -%}

CASCADE DELETE just once

The delete with the cascade option only applied to tables with foreign keys defined. If you do a delete, and it says you cannot because it would violate the foreign key constraint, the cascade will cause it to delete the offending rows.

If you want to delete associated rows in this way, you will need to define the foreign keys first. Also, remember that unless you explicitly instruct it to begin a transaction, or you change the defaults, it will do an auto-commit, which could be very time consuming to clean up.

remove / reset inherited css from an element

From what I understand you want to use a div that inherits from no class but yours. As mentioned in the previous reply you cannot completely reset a div inheritance. However, what worked for me with that issue was to use another element - one that is not frequent and certainly not used in the current html page. A good example, is to use instead of then customize it to look just like your ideal would.

area { background-color : red; }

How to trigger click on page load?

$("document").ready({
    $("ul.galleria li:first-child img").click(function(){alert('i work click triggered'});
}); 

$("document").ready(function() { 
    $("ul.galleria li:first-child img").trigger('click'); 
}); 

just make sure the click handler is added prior to the trigger event in the call stack sequence.

  $("document").ready(function() { 
        $("ul.galleria li:first-child img").trigger('click'); 
    }); 

   $("document").ready({
        $("ul.galleria li:first-child img").click(function(){alert('i fail click triggered'});
    }); 

C++ queue - simple example

std::queue<myclass*> my_queue; will do the job.

See here for more information on this container.

How to get the max of two values in MySQL?

To get the maximum value of a column across a set of rows:

SELECT MAX(column1) FROM table; -- expect one result

To get the maximum value of a set of columns, literals, or variables for each row:

SELECT GREATEST(column1, 1, 0, @val) FROM table; -- expect many results

Does VBA have Dictionary Structure?

An additional dictionary example that is useful for containing frequency of occurence.

Outside of loop:

Dim dict As New Scripting.dictionary
Dim MyVar as String

Within a loop:

'dictionary
If dict.Exists(MyVar) Then
    dict.Item(MyVar) = dict.Item(MyVar) + 1 'increment
Else
    dict.Item(MyVar) = 1 'set as 1st occurence
End If

To check on frequency:

Dim i As Integer
For i = 0 To dict.Count - 1 ' lower index 0 (instead of 1)
    Debug.Print dict.Items(i) & " " & dict.Keys(i)
Next i

Formatting code in Notepad++

In my notepad++, it seems TextFX needs a perl environment to format HTML files. Tidy2 demands nothing so I think it's more handy.

Change the bullet color of list

Example JS Fiddle

Bullets take the color property of the list:

.listStyle {
    color: red;
}

Note if you want your list text to be a different colour, you have to wrap it in say, a p, for example:

.listStyle p {
    color: black;
}

Example HTML:

<ul class="listStyle">
    <li>
        <p><strong>View :</strong> blah blah.</p>
    </li>
    <li>
        <p><strong>View :</strong> blah blah.</p>
    </li>
</ul>

How do I declare and use variables in PL/SQL like I do in T-SQL?

In Oracle PL/SQL, if you are running a query that may return multiple rows, you need a cursor to iterate over the results. The simplest way is with a for loop, e.g.:

declare
  myname varchar2(20) := 'tom';
begin
  for result_cursor in (select * from mytable where first_name = myname) loop
    dbms_output.put_line(result_cursor.first_name);
    dbms_output.put_line(result_cursor.other_field);
  end loop;
end;

If you have a query that returns exactly one row, then you can use the select...into... syntax, e.g.:

declare 
  myname varchar2(20);
begin
  select first_name into myname 
    from mytable 
    where person_id = 123;
end;

Eclipse copy/paste entire line keyboard shortcut

On my Mac the default setting is is ALT+CMD+Down

You can change/view all key bindings by going Eclipse -> Preferences (shortcut CMD+,) and then General -> Keys

How to get input text length and validate user in javascript

JavaScript validation is not secure as anybody can change what your script does in the browser. Using it for enhancing the visual experience is ok though.

var textBox = document.getElementById("myTextBox");
var textLength = textBox.value.length;
if(textLength > 5)
{
    //red
    textBox.style.backgroundColor = "#FF0000";
}
else
{
    //green
    textBox.style.backgroundColor = "#00FF00";
}

How to insert data into SQL Server

You have to set Connection property of Command object and use parametersized query instead of hardcoded SQL to avoid SQL Injection.

 using(SqlConnection openCon=new SqlConnection("your_connection_String"))
    {
      string saveStaff = "INSERT into tbl_staff (staffName,userID,idDepartment) VALUES (@staffName,@userID,@idDepartment)";

      using(SqlCommand querySaveStaff = new SqlCommand(saveStaff))
       {
         querySaveStaff.Connection=openCon;
         querySaveStaff.Parameters.Add("@staffName",SqlDbType.VarChar,30).Value=name;
         .....
         openCon.Open();

         querySaveStaff.ExecuteNonQuery();
       }
     }

How to Alter a table for Identity Specification is identity SQL Server

You cannot "convert" an existing column into an IDENTITY column - you will have to create a new column as INT IDENTITY:

ALTER TABLE ProductInProduct 
ADD NewId INT IDENTITY (1, 1);

Update:

OK, so there is a way of converting an existing column to IDENTITY. If you absolutely need this - check out this response by Martin Smith with all the gory details.

std::wstring VS std::string

  1. When you want to have wide characters stored in your string. wide depends on the implementation. Visual C++ defaults to 16 bit if i remember correctly, while GCC defaults depending on the target. It's 32 bits long here. Please note wchar_t (wide character type) has nothing to do with unicode. It's merely guaranteed that it can store all the members of the largest character set that the implementation supports by its locales, and at least as long as char. You can store unicode strings fine into std::string using the utf-8 encoding too. But it won't understand the meaning of unicode code points. So str.size() won't give you the amount of logical characters in your string, but merely the amount of char or wchar_t elements stored in that string/wstring. For that reason, the gtk/glib C++ wrapper folks have developed a Glib::ustring class that can handle utf-8.

    If your wchar_t is 32 bits long, then you can use utf-32 as an unicode encoding, and you can store and handle unicode strings using a fixed (utf-32 is fixed length) encoding. This means your wstring's s.size() function will then return the right amount of wchar_t elements and logical characters.

  2. Yes, char is always at least 8 bit long, which means it can store all ASCII values.
  3. Yes, all major compilers support it.

PopupWindow $BadTokenException: Unable to add window -- token null is not valid

Use:

YourActivityName.this

Instead of:

getApplicationContext();

How do I deploy Node.js applications as a single executable file?

Not to beat a dead horse, but the solution you're describing sounds a lot like Node-Webkit.

From the Git Page:

node-webkit is an app runtime based on Chromium and node.js. You can write native apps in HTML and JavaScript with node-webkit. It also lets you call Node.js modules directly from the DOM and enables a new way of writing native applications with all Web technologies.

These instructions specifically detail the creation of a single file app that a user can execute, and this portion describes the external dependencies.

I'm not sure if it's the exact solution, but it seems pretty close.

Hope it helps!

Expanding a parent <div> to the height of its children

_x000D_
_x000D_
#parent{_x000D_
  background-color:green;_x000D_
  height:auto;_x000D_
  width:300px;_x000D_
  overflow:hidden;_x000D_
}_x000D_
_x000D_
#childRightCol{_x000D_
  color:gray;_x000D_
  background-color:yellow;_x000D_
  margin:10px;_x000D_
  padding:10px;_x000D_
}
_x000D_
<div id="parent">_x000D_
    <div id="childRightCol">_x000D_
        <p>_x000D_
          Lorem ipsum dolor sit amet, consectetur adipiscing elit. Quisque vulputate sit amet neque ac consequat._x000D_
        </p>_x000D_
    </div>_x000D_
  </div>
_x000D_
_x000D_
_x000D_

you are manage by using overflow:hidden; property in css

How to make EditText not editable through XML in Android?

When I want an activity to not focus on the EditText and also not show keyboard when clicked, this is what worked for me.

Adding attributes to the main layout

android:descendantFocusability="beforeDescendants"
android:focusableInTouchMode="true"

and then the EditText field

android:focusable="false"
android:focusableInTouchMode="false"

Here is an example:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_home"
    android:background="@drawable/bg_landing"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="0dp"
    android:paddingLeft="0dp"
    android:paddingRight="0dp"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:descendantFocusability="beforeDescendants"
    android:focusableInTouchMode="true"
    tools:context="com.woppi.woppi.samplelapp.HomeActivity">

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@null"
        android:inputType="textPersonName"
        android:ems="10"
        android:id="@+id/fromEditText"
        android:layout_weight="1"
        android:hint="@string/placeholder_choose_language"
        android:textColor="@android:color/white"
        android:textColorHint="@android:color/darker_gray"
        android:focusable="false"
        android:focusableInTouchMode="false"
        android:onClick="onSelectFromLanguage" />

</RelativeLayout>

Streaming via RTSP or RTP in HTML5

With VLC i'm able to transcode a live RTSP stream (mpeg4) to an HTTP stream in a OGG format (Vorbis/Theora). The quality is poor but the video work in Chrome 9. I have also tested with a trancoding in WEBM (VP8) but it's don't seem to work (VLC have the option but i don't know if it's really implemented for now..)

The first to have a doc on this should notify us ;)

How to remove an app with active device admin enabled on Android?

On Samsung go to "Settings" -> "Lock screen and security" -> "Other security settings" -> "Phone administrators" and deselect the admin which you want to uninstall.

The "security" word was hidden on my display, so it was not obvious that I should click on "Lock screen".

How do I get a substring of a string in Python?

>>> x = "Hello World!"
>>> x[2:]
'llo World!'
>>> x[:2]
'He'
>>> x[:-2]
'Hello Worl'
>>> x[-2:]
'd!'
>>> x[2:-2]
'llo Worl'

Python calls this concept "slicing" and it works on more than just strings. Take a look here for a comprehensive introduction.

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed

Please make sure you are using latest jdbc connector as per the mysql. I was facing this problem and when I replaced my old jdbc connector with the latest one, the problem was solved.

You can download latest jdbc driver from https://dev.mysql.com/downloads/connector/j/

Select Operating System as Platform Independent. It will show you two options. One as tar and one as zip. Download the zip and extract it to get the jar file and replace it with your old connector.

This is not only for hibernate framework, it can be used with any platform which requires a jdbc connector.

Java 8 - Difference between Optional.flatMap and Optional.map

You can refer below link to understand in detail (best explanation which I could find):

https://www.programmergirl.com/java-8-map-flatmap-difference/

Both map and flatMap - accept Function. The return type of map() is a single value whereas flatMap is returning stream of values

<R> Stream<R> map(Function<? super T, ? extends R> mapper)

<R> Stream<R> flatMap(Function<? super T, ? extends Stream<? extends R>> mapper)

Difference between using bean id and name in Spring configuration file

Both id and name are bean identifiers in Spring IOC container/ApplicationContecxt. The id attribute lets you specify exactly one id but using name attribute you can give alias name to that bean.

You can check the spring doc here.

Should composer.lock be committed to version control?

If you’re concerned about your code breaking, you should commit the composer.lock to your version control system to ensure all your project collaborators are using the same version of the code. Without a lock file, you will get new third-party code being pulled down each time.

The exception is when you use a meta apps, libraries where the dependencies should be updated on install (like the Zend Framework 2 Skeleton App). So the aim is to grab the latest dependencies each time when you want to start developing.

Source: Composer: It’s All About the Lock File

See also: What are the differences between composer update and composer install?

Vue is not defined

Sometimes the problem may be if you import that like this:

const Vue = window.vue;

this may overwrite the original Vue reference.

Short description of the scoping rules?

Essentially, the only thing in Python that introduces a new scope is a function definition. Classes are a bit of a special case in that anything defined directly in the body is placed in the class's namespace, but they are not directly accessible from within the methods (or nested classes) they contain.

In your example there are only 3 scopes where x will be searched in:

  • spam's scope - containing everything defined in code3 and code5 (as well as code4, your loop variable)

  • The global scope - containing everything defined in code1, as well as Foo (and whatever changes after it)

  • The builtins namespace. A bit of a special case - this contains the various Python builtin functions and types such as len() and str(). Generally this shouldn't be modified by any user code, so expect it to contain the standard functions and nothing else.

More scopes only appear when you introduce a nested function (or lambda) into the picture. These will behave pretty much as you'd expect however. The nested function can access everything in the local scope, as well as anything in the enclosing function's scope. eg.

def foo():
    x=4
    def bar():
        print x  # Accesses x from foo's scope
    bar()  # Prints 4
    x=5
    bar()  # Prints 5

Restrictions:

Variables in scopes other than the local function's variables can be accessed, but can't be rebound to new parameters without further syntax. Instead, assignment will create a new local variable instead of affecting the variable in the parent scope. For example:

global_var1 = []
global_var2 = 1

def func():
    # This is OK: It's just accessing, not rebinding
    global_var1.append(4) 

    # This won't affect global_var2. Instead it creates a new variable
    global_var2 = 2 

    local1 = 4
    def embedded_func():
        # Again, this doen't affect func's local1 variable.  It creates a 
        # new local variable also called local1 instead.
        local1 = 5
        print local1

    embedded_func() # Prints 5
    print local1    # Prints 4

In order to actually modify the bindings of global variables from within a function scope, you need to specify that the variable is global with the global keyword. Eg:

global_var = 4
def change_global():
    global global_var
    global_var = global_var + 1

Currently there is no way to do the same for variables in enclosing function scopes, but Python 3 introduces a new keyword, "nonlocal" which will act in a similar way to global, but for nested function scopes.

What are named pipes?

Named pipes in a unix/linux context can be used to make two different shells to communicate since a shell just can't share anything with another.

Furthermore, one script instantiated twice in the same shell can't share anything through the two instances. I found a use for named pipes when coding a daemon that contains the start() and stop() function, and I wanted to use the same script to perform the two actions.

Without named pipes (or any kind of semaphore) starting the script in the background is not a problem. The thing is when it finishes you just can't access the instance in background.

So when you want to send him the stop command you just can't: running the same script without named pipes and calling the stop() function won't do anything since you are actually running another instance.

The solution was to implement two pipes, one READ and the other WRITE when you start the daemon. Then make him, among its other tasks, listen to the READ pipe. Then the Stop() function contains a command that will write a message in the pipe, that will be handled by the background running script that will perform an exit 0. This way our second instance of the same script has only on task to do: tell the first instance to stop.

This way one and only one script can start and stop itself.

Of course you have different ways to do it by triggering the stop via a touch for example. But this one is nice and interesting to code.

How can I create an error 404 in PHP?

Immediately after that line try closing the response using exit or die()

header($_SERVER["SERVER_PROTOCOL"]." 404 Not Found");
exit;

or

header($_SERVER["SERVER_PROTOCOL"]." 404 Not Found");
die();

Make index.html default, but allow index.php to be visited if typed in

Hi,

Well, I have tried the methods mentioned above! it's working yes, but not exactly the way I wanted. I wanted to redirect the default page extension to the main domain with our further action.

Here how I do that...

# Accesible Index Page
<IfModule dir_module>
 DirectoryIndex index.php index.html
 RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /index\.(html|htm|php|php3|php5|shtml|phtml) [NC]
 RewriteRule ^index\.html|htm|php|php3|php5|shtml|phtml$ / [R=301,L]
</IfModule>

The above code simply captures any index.* and redirect it to the main domain.

Thank you

How to redirect from one URL to another URL?

You can redirect anything or more URL via javascript, Just simple window.location.href with if else

Use this code,

<script>
if(window.location.href == 'old_url')
{
    window.location.href="new_url";
}


//Another url redirect
if(window.location.href == 'old_url2')
{
    window.location.href="new_url2";
}
</script>

You can redirect many URL's by this procedure. Thanks.

Resolving javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed Error?

It is possible to disable SSL verification programmatically. Works in a pinch for dev, but not recommended for production since you'll want to either use "real" SSL verification there or install and use your own trusted keys and then still use "real" SSL verification.

Below code works for me:

import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

import javax.net.ssl.X509TrustManager;

public class TrustAnyTrustManager implements X509TrustManager {

  public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
  }

  public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
  }

  public X509Certificate[] getAcceptedIssuers() {
    return null;
  }
}

             HttpsURLConnection conn = null;
             URL url = new URL(serviceUrl);
             conn = (HttpsURLConnection) url.openConnection();
             SSLContext sc = SSLContext.getInstance("SSL");  
             sc.init(null, new TrustManager[]{new TrustAnyTrustManager()}, new java.security.SecureRandom());  
                    // Create all-trusting host name verifier
             HostnameVerifier allHostsValid = new HostnameVerifier() {
               public boolean verify(String hostname, SSLSession session) {
                return true;
              }
            };
            conn.setHostnameVerifier(allHostsValid);

Or if you don't control the Connections underneath, you can also override SSL verification globally for all connections https://stackoverflow.com/a/19542614/32453

If you are using Apache HTTPClient you must disable it "differently" (sadly): https://stackoverflow.com/a/2703233/32453

How to generate .NET 4.0 classes from xsd?

simple enough; just run (at the vs command prompt)

xsd your.xsd /classes

(which will create your.cs). Note, however, that most of the intrinsic options here haven't changed much since 2.0

For the options, use xsd /? or see MSDN; for example /enableDataBinding can be useful.

Get current value when change select option - Angular2

You can Use ngValue. ngValue passes sting and object both.

Pass as Object:

<select (change)="onItemChange($event.value)">
    <option *ngFor="#obj of arr" [ngValue]="obj.value">
       {{obj.value}}
    </option>
</select>

Pass as String:

<select (change)="onItemChange($event.value)">
    <option *ngFor="#obj of arr" [ngValue]="obj">
       {{obj.value}}
    </option>
</select>

How to get cookie's expire time

This is difficult to achieve, but the cookie expiration date can be set in another cookie. This cookie can then be read later to get the expiration date. Maybe there is a better way, but this is one of the methods to solve your problem.

npm WARN package.json: No repository field

It's just a check as of NPM v1.2.20, they report this as a warning.

However, don't worry, there are sooooooo many packages which still don't have the repository field in their package.json. The field is used for informational purposes.

In the case you're a package author, put the repository in your package.json, like this:

"repository": {
  "type": "git",
  "url": "git://github.com/username/repository.git"
}

Read more about the repository field, and see the logged bug for further details.


Additionally, as originally reported by @dan_nl, you can set private key in your package.json.
This will not only stop you from accidentally running npm publish in your app, but will also stop NPM from printing warnings regarding package.json problems.

{
  "name": "my-super-amazing-app",
  "version": "1.0.0",
  "private": true
}

How can I see what I am about to push with git?

To see which files are changed and view the actual code changes compared to the master branch you could use:

git diff --stat --patch origin master

NOTE: If you happen to use any of the Intellij IDEs then you can right-click your top-level project, select Git > Compare with branch > and pick the origin you want e.g. origin/master. In the file tree that will appear you can double-click the files to see a visual diff. Unlike the command-line option above you can edit your local versions from the diff window.

Changing datagridview cell color dynamically

Considere use DataBindingComplete event for update the style. The next code change the style of the cell:

    private void Grid_DataBindingComplete(object sender, DataGridViewBindingCompleteEventArgs e)
    {
        this.Grid.Rows[2].Cells[1].Style.BackColor = Color.Green;
    }

Post-increment and Pre-increment concept?

The pre increment is before increment value ++ e.g.:

(++v) or 1 + v

The post increment is after increment the value ++ e.g.:

(rmv++) or rmv + 1

Program:

int rmv = 10, vivek = 10;
cout << "rmv++ = " << rmv++ << endl; // the value is 10
cout << "++vivek = " << ++vivek; // the value is 11

HTTP 401 - what's an appropriate WWW-Authenticate header value?

When indicating HTTP Basic Authentication we return something like:

WWW-Authenticate: Basic realm="myRealm"

Whereas Basic is the scheme and the remainder is very much dependent on that scheme. In this case realm just provides the browser a literal that can be displayed to the user when prompting for the user id and password.

You're obviously not using Basic however since there is no point having session expiry when Basic Auth is used. I assume you're using some form of Forms based authentication.

From recollection, Windows Challenge Response uses a different scheme and different arguments.

The trick is that it's up to the browser to determine what schemes it supports and how it responds to them.

My gut feel if you are using forms based authentication is to stay with the 200 + relogin page but add a custom header that the browser will ignore but your AJAX can identify.

For a really good User + AJAX experience, get the script to hang on to the AJAX request that found the session expired, fire off a relogin request via a popup, and on success, resubmit the original AJAX request and carry on as normal.

Avoid the cheat that just gets the script to hit the site every 5 mins to keep the session alive cause that just defeats the point of session expiry.

The other alternative is burn the AJAX request but that's a poor user experience.

How to convert color code into media.brush?

What version of WPF are you using? I tried in both 3.5 and 4.0, and Fill="#FF000000" should work fine in a in the XAML. There is another syntax, however, if it doesn't. Here's a 3.5 XAML that I tested with two different ways. Better yet would be to use a resource.

<Window x:Class="WpfApplication2.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
<Grid>
    <Rectangle Height="100" HorizontalAlignment="Left" Margin="100,12,0,0" Name="rectangle1" Stroke="Black" VerticalAlignment="Top" Width="200" Fill="#FF00AE00" />
    <Rectangle Height="100" HorizontalAlignment="Left" Margin="100,132,0,0" Name="rectangle2" Stroke="Black" VerticalAlignment="Top" Width="200" >
        <Rectangle.Fill>
            <SolidColorBrush Color="#FF00AE00" />
        </Rectangle.Fill>
    </Rectangle>
</Grid>

Why does this "Slow network detected..." log appear in Chrome?

Go to the Font's stylesheet.css and add font-display: block; in all @font-face { }

This Stackoverflow Answer helped me..

Below is the Summary of the answer

If you can access to css of this extension, simply add font-display:block; on font-face definition or send feedback to developer of this extension:)

@font-face {
  font-family: ExampleFont;
  src: url(/path/to/fonts/examplefont.woff) format('woff'),
       url(/path/to/fonts/examplefont.eot) format('eot');
  font-weight: 400;
  font-style: normal;
  font-display: block;
}

FB OpenGraph og:image not pulling images (possibly https?)

In my case, it seems that the crawler is just having a bug. I've tried:

  • Changing links to http only
  • Removing end white space
  • Switching back to http completely
  • Reinstalling the website
  • Installing a bunch of OG plugins (I use WordPress)
  • Suspecting the server has a weird misconfiguration that blocks the bots (because all the OG checkers are unable to fetch tags, and other requests to my sites are unstable)

None of these works. This costed me a week. And suddenly out of nowhere it seems to work again.

Here are my research, if someone meets this problem again:

Also, there are more checkers other than the Facebook's Object Debugger for you to check: OpenGraphCheck.com, Abhinay Rathore's Open Graph Tester, Iframely's Embed Codes, Card Validator | Twitter Developers.

How to change indentation mode in Atom?

Changing language-specific configuration

I changed the default tab settings, and it still did not impact when I was editing my files, which were Python files. It also did not change when I modified the "*" setting in ~/.atom/config.cson . I don't have a good explanation for either of those.

However, when I added the following to my config.cson, I was able to change the tab in my Python files to 2 spaces:

'.source.python':
  editor:
    tabLength: 2

Thanks to this resource for the solution: Tab key not respecting tab length

how to rotate text left 90 degree and cell size is adjusted according to text in html

Unfortunately while I thought these answers may have worked for me, I struggled with a solution, as I'm using tables inside responsive tables - where the overflow-x is played with.

So, with that in mind, have a look at this link for a cleaner way, which doesn't have the weird width overflow issues. It worked for me in the end and was very easy to implement.

https://css-tricks.com/rotated-table-column-headers/

How can I symlink a file in Linux?

I'd like to present a plainer-English version of the descriptions already presented.

 ln -s  /path-text/of-symbolic-link  /path/to/file-to-hold-that-text

The "ln" command creates a link-FILE, and the "-s" specifies that the type of link will be symbolic. An example of a symbolic-link file can be found in a WINE installation (using "ls -la" to show one line of the directory contents):

 lrwxrwxrwx 1 me power 11 Jan  1 00:01 a: -> /mnt/floppy

Standard file-info stuff is at left (although note the first character is an "l" for "link"); the file-name is "a:" and the "->" also indicates the file is a link. It basically tells WINE how Windows "Drive A:" is to be associated with a floppy drive in Linux. To actually create a symbolic link SIMILAR to that (in current directory, and to actually do this for WINE is more complicated; use the "winecfg" utility):

 ln -s  /mnt/floppy  a:   //will not work if file a: already exists

What does --net=host option in Docker command really do?

  1. you can create your own new network like --net="anyname"
  2. this is done to isolate the services from different container.
  3. suppose the same service are running in different containers, but the port mapping remains same, the first container starts well , but the same service from second container will fail. so to avoid this, either change the port mappings or create a network.

On design patterns: When should I use the singleton?

Read only singletons storing some global state (user language, help filepath, application path) are reasonable. Be carefull of using singletons to control business logic - single almost always ends up being multiple

Scroll to a specific Element Using html

Should you want to resort to using a plug-in, malihu-custom-scrollbar-plugin, could do the job. It performs an actual scroll, not just a jump. You can even specify the speed/momentum of scroll. It also lets you set up a menu (list of links to scroll to), which have their CSS changed based on whether the anchors-to-scroll-to are in viewport, and other useful features.

There are demo on the author's site and let our company site serve as a real-world example too.

How to display multiple images in one figure correctly?

You could try the following:

import matplotlib.pyplot as plt
import numpy as np

def plot_figures(figures, nrows = 1, ncols=1):
    """Plot a dictionary of figures.

    Parameters
    ----------
    figures : <title, figure> dictionary
    ncols : number of columns of subplots wanted in the display
    nrows : number of rows of subplots wanted in the figure
    """

    fig, axeslist = plt.subplots(ncols=ncols, nrows=nrows)
    for ind,title in zip(range(len(figures)), figures):
        axeslist.ravel()[ind].imshow(figures[title], cmap=plt.jet())
        axeslist.ravel()[ind].set_title(title)
        axeslist.ravel()[ind].set_axis_off()
    plt.tight_layout() # optional



# generation of a dictionary of (title, images)
number_of_im = 20
w=10
h=10
figures = {'im'+str(i): np.random.randint(10, size=(h,w)) for i in range(number_of_im)}

# plot of the images in a figure, with 5 rows and 4 columns
plot_figures(figures, 5, 4)

plt.show()

However, this is basically just copy and paste from here: Multiple figures in a single window for which reason this post should be considered to be a duplicate.

I hope this helps.

How to clone a Date object?

This is the cleanest approach

_x000D_
_x000D_
let dat = new Date() _x000D_
let copyOf = new Date(dat.valueOf())_x000D_
_x000D_
console.log(dat);_x000D_
console.log(copyOf);
_x000D_
_x000D_
_x000D_

MySQL & Java - Get id of the last inserted value (JDBC)

Alternatively you can do:

Statement stmt = db.prepareStatement(query, Statement.RETURN_GENERATED_KEYS);
numero = stmt.executeUpdate();

ResultSet rs = stmt.getGeneratedKeys();
if (rs.next()){
    risultato=rs.getString(1);
}

But use Sean Bright's answer instead for your scenario.

Array.push() and unique items

try .includes()

[1, 2, 3].includes(2);     // true
[1, 2, 3].includes(4);     // false
[1, 2, 3].includes(3, 3);  // false
[1, 2, 3].includes(3, -1); // true
[1, 2, NaN].includes(NaN); // true

so something like

const array = [1, 3];
if (!array.includes(2))
    array.push(2);

note the browser compatibility at the bottom of the page, however.

How to load Spring Application Context

Add this at the start of main

ApplicationContext context = new ClassPathXmlApplicationContext("path/to/applicationContext.xml");

JobLauncher launcher=(JobLauncher)context.getBean("launcher");
Job job=(Job)context.getBean("job");

//Get as many beans you want
//Now do the thing you were doing inside test method
StopWatch sw = new StopWatch();
sw.start();
launcher.run(job, jobParameters);
sw.stop();
//initialize the log same way inside main
logger.info(">>> TIME ELAPSED:" + sw.prettyPrint());

How to prevent http file caching in Apache httpd (MAMP)

Tried this? Should work in both .htaccess, httpd.conf and in a VirtualHost (usually placed in httpd-vhosts.conf if you have included it from your httpd.conf)

<filesMatch "\.(html|htm|js|css)$">
  FileETag None
  <ifModule mod_headers.c>
     Header unset ETag
     Header set Cache-Control "max-age=0, no-cache, no-store, must-revalidate"
     Header set Pragma "no-cache"
     Header set Expires "Wed, 11 Jan 1984 05:00:00 GMT"
  </ifModule>
</filesMatch>

100% Prevent Files from being cached

This is similar to how google ads employ the header Cache-Control: private, x-gzip-ok="" > to prevent caching of ads by proxies and clients.

From http://www.askapache.com/htaccess/using-http-headers-with-htaccess.html

And optionally add the extension for the template files you are retrieving if you are using an extension other than .html for those.

Is Laravel really this slow?

I found that biggest speed gain with Laravel 4 you can achieve choosing right session drivers;

Sessions "driver" file;

Requests per second:    188.07 [#/sec] (mean)
Time per request:       26.586 [ms] (mean)
Time per request:       5.317 [ms] (mean, across all concurrent requests)


Session "driver" database;

Requests per second:    41.12 [#/sec] (mean)
Time per request:       121.604 [ms] (mean)
Time per request:       24.321 [ms] (mean, across all concurrent requests)

Hope that helps

What's the yield keyword in JavaScript?

To give a complete answer: yield is working similar to return, but in a generator.

As for the commonly given example, this works as follows:

function *squareGen(x) {
    var i;
    for (i = 0; i < x; i++) {
        yield i*i;
    }
}

var gen = squareGen(3);

console.log(gen.next().value); // prints 0
console.log(gen.next().value); // prints 1
console.log(gen.next().value); // prints 4

But theres also a second purpose of the yield keyword. It can be used to send values to the generator.

To clarify, a small example:

function *sendStuff() {
    y = yield (0);
    yield y*y;
}

var gen = sendStuff();

console.log(gen.next().value); // prints 0
console.log(gen.next(2).value); // prints 4

This works, as the value 2 is assigned to y, by sending it to the generator, after it stopped at the first yield (which returned 0).

This enables us to to some really funky stuff. (look up coroutine)

How can I get browser to prompt to save password?

Not every browser (e.g. IE 6) has options to remember credentials.

One thing you can do is to (once the user successfully logs in) store the user information via cookie and have a "Remember Me on this machine" option. That way, when the user comes again (even if he's logged off), your web application can retrieve the cookie and get the user information (user ID + Session ID) and allow him/her to carry on working.

Hope this can be suggestive. :-)

How to run Conda?

It turns out that I had not set the path.

To do so, I first had to edit .bash_profile (I downloaded it to my local desktop to do that, I do not know how to text edit a file from linux)

Then add this to .bash_profile:

PATH=$PATH:$HOME/anaconda/bin

to_string not declared in scope

//Try this if you can't use -std=c++11:-
int number=55;
char tempStr[32] = {0};
sprintf(tempStr, "%d", number);

get next sequence value from database using hibernate

Here is what worked for me (specific to Oracle, but using scalar seems to be the key)

Long getNext() {
    Query query = 
        session.createSQLQuery("select MYSEQ.nextval as num from dual")
            .addScalar("num", StandardBasicTypes.BIG_INTEGER);

    return ((BigInteger) query.uniqueResult()).longValue();
}

Thanks to the posters here: springsource_forum

Android set bitmap to Imageview

    //decode base64 string to image
    imageBytes = Base64.decode(encodedImage, Base64.DEFAULT);
    Bitmap decodedImage = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length);
    image.setImageBitmap(decodedImage);

  //setImageBitmap is imp

How to install pip3 on Windows?

On Windows pip3 should be in the Scripts path of your Python installation:

C:\path\to\python\Scripts\pip3

Use:

where python

to find out where your Python executable(s) is/are located. The result should look like this:

C:\path\to\python\python.exe

or:

C:\path\to\python\python3.exe

You can check if pip3 works with this absolute path:

C:\path\to\python\Scripts\pip3

if yes, add C:\path\to\python\Scripts to your environmental variable PATH .

Groovy String to Date

The first argument to parse() is the expected format. You have to change that to Date.parse("E MMM dd H:m:s z yyyy", testDate) for it to work. (Note you don't need to create a new Date object, it's a static method)

If you don't know in advance what format, you'll have to find a special parsing library for that. In Ruby there's a library called Chronic, but I'm not aware of a Groovy equivalent. Edit: There is a Java port of the library called jChronic, you might want to check it out.

Catch multiple exceptions at once?

Since I felt like these answers just touched the surface, I attempted to dig a bit deeper.

So what we would really want to do is something that doesn't compile, say:

// Won't compile... damn
public static void Main()
{
    try
    {
        throw new ArgumentOutOfRangeException();
    }
    catch (ArgumentOutOfRangeException)
    catch (IndexOutOfRangeException) 
    {
        // ... handle
    }

The reason we want this is because we don't want the exception handler to catch things that we need later on in the process. Sure, we can catch an Exception and check with an 'if' what to do, but let's be honest, we don't really want that. (FxCop, debugger issues, uglyness)

So why won't this code compile - and how can we hack it in such a way that it will?

If we look at the code, what we really would like to do is forward the call. However, according to the MS Partition II, IL exception handler blocks won't work like this, which in this case makes sense because that would imply that the 'exception' object can have different types.

Or to write it in code, we ask the compiler to do something like this (well it's not entirely correct, but it's the closest possible thing I guess):

// Won't compile... damn
try
{
    throw new ArgumentOutOfRangeException();
}
catch (ArgumentOutOfRangeException e) {
    goto theOtherHandler;
}
catch (IndexOutOfRangeException e) {
theOtherHandler:
    Console.WriteLine("Handle!");
}

The reason that this won't compile is quite obvious: what type and value would the '$exception' object have (which are here stored in the variables 'e')? The way we want the compiler to handle this is to note that the common base type of both exceptions is 'Exception', use that for a variable to contain both exceptions, and then handle only the two exceptions that are caught. The way this is implemented in IL is as 'filter', which is available in VB.Net.

To make it work in C#, we need a temporary variable with the correct 'Exception' base type. To control the flow of the code, we can add some branches. Here goes:

    Exception ex;
    try
    {
        throw new ArgumentException(); // for demo purposes; won't be caught.
        goto noCatch;
    }
    catch (ArgumentOutOfRangeException e) {
        ex = e;
    }
    catch (IndexOutOfRangeException e) {
        ex = e;
    }

    Console.WriteLine("Handle the exception 'ex' here :-)");
    // throw ex ?

noCatch:
    Console.WriteLine("We're done with the exception handling.");

The obvious disadvantages for this are that we cannot re-throw properly, and -well let's be honest- that it's quite the ugly solution. The uglyness can be fixed a bit by performing branch elimination, which makes the solution slightly better:

Exception ex = null;
try
{
    throw new ArgumentException();
}
catch (ArgumentOutOfRangeException e)
{
    ex = e;
}
catch (IndexOutOfRangeException e)
{
    ex = e;
}
if (ex != null)
{
    Console.WriteLine("Handle the exception here :-)");
}

That leaves just the 're-throw'. For this to work, we need to be able to perform the handling inside the 'catch' block - and the only way to make this work is by an catching 'Exception' object.

At this point, we can add a separate function that handles the different types of Exceptions using overload resolution, or to handle the Exception. Both have disadvantages. To start, here's the way to do it with a helper function:

private static bool Handle(Exception e)
{
    Console.WriteLine("Handle the exception here :-)");
    return true; // false will re-throw;
}

public static void Main()
{
    try
    {
        throw new OutOfMemoryException();
    }
    catch (ArgumentException e)
    {
        if (!Handle(e)) { throw; }
    }
    catch (IndexOutOfRangeException e)
    {
        if (!Handle(e)) { throw; }
    }

    Console.WriteLine("We're done with the exception handling.");

And the other solution is to catch the Exception object and handle it accordingly. The most literal translation for this, based on the context above is this:

try
{
    throw new ArgumentException();
}
catch (Exception e)
{
    Exception ex = (Exception)(e as ArgumentException) ?? (e as IndexOutOfRangeException);
    if (ex != null)
    {
        Console.WriteLine("Handle the exception here :-)");
        // throw ?
    }
    else 
    {
        throw;
    }
}

So to conclude:

  • If we don't want to re-throw, we might consider catching the right exceptions, and storing them in a temporary.
  • If the handler is simple, and we want to re-use code, the best solution is probably to introduce a helper function.
  • If we want to re-throw, we have no choice but to put the code in a 'Exception' catch handler, which will break FxCop and your debugger's uncaught exceptions.

Blurry text after using CSS transform: scale(); in Chrome

In Chrome 74.0.3729.169, current as of 5-25-19, there doesn't seem to be any fix for blurring occurring at certain browser zoom levels caused by the transform. Even a simple TransformY(50px) will blur the element. This doesn't occur in current versions of Firefox, Edge or Safari, and it doesn't seem to occur at all zoom levels.

How to darken an image on mouseover?

Make the image 100% bright so it is clear. And then on Img hover reduce it to whatever brightness you want.

_x000D_
_x000D_
img {_x000D_
   -webkit-transition: all 1s ease;_x000D_
   -moz-transition: all 1s ease;_x000D_
   -o-transition: all 1s ease;_x000D_
   -ms-transition: all 1s ease;_x000D_
   transition: all 1s ease;_x000D_
}_x000D_
_x000D_
img:hover {_x000D_
   -webkit-filter: brightness(70%);_x000D_
   filter: brightness(70%);_x000D_
}
_x000D_
<img src="http://dummyimage.com/300x150/ebebeb/000.jpg">
_x000D_
_x000D_
_x000D_

That will do it, Hope that helps

Fork() function in C

First a link to some documentation of fork()

http://pubs.opengroup.org/onlinepubs/009695399/functions/fork.html

The pid is provided by the kernel. Every time the kernel create a new process it will increase the internal pid counter and assign the new process this new unique pid and also make sure there are no duplicates. Once the pid reaches some high number it will wrap and start over again.

So you never know what pid you will get from fork(), only that the parent will keep it's unique pid and that fork will make sure that the child process will have a new unique pid. This is stated in the documentation provided above.

If you continue reading the documentation you will see that fork() return 0 for the child process and the new unique pid of the child will be returned to the parent. If the child want to know it's own new pid you will have to query for it using getpid().

pid_t pid = fork()
if(pid == 0) {
    printf("this is a child: my new unique pid is %d\n", getpid());
} else {
    printf("this is the parent: my pid is %d and I have a child with pid %d \n", getpid(), pid);
}

and below is some inline comments on your code

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>

int main() {
    pid_t pid1, pid2, pid3;
    pid1=0, pid2=0, pid3=0;
    pid1= fork(); /* A */
    if(pid1 == 0){
        /* This is child A */
        pid2=fork(); /* B */
        pid3=fork(); /* C */
    } else {
        /* This is parent A */
        /* Child B and C will never reach this code */
        pid3=fork(); /* D */
        if(pid3==0) {
            /* This is child D fork'ed from parent A */
            pid2=fork(); /* E */
        }
        if((pid1 == 0)&&(pid2 == 0)) {
            /* pid1 will never be 0 here so this is dead code */
            printf("Level 1\n");
        }
        if(pid1 !=0) {
            /* This is always true for both parent and child E */
            printf("Level 2\n");
        }
        if(pid2 !=0) {
           /* This is parent E (same as parent A) */
           printf("Level 3\n");
        }
        if(pid3 !=0) {
           /* This is parent D (same as parent A) */
           printf("Level 4\n");
        }
    }
    return 0;
}

How to set 'X-Frame-Options' on iframe?

This is also a new browser security feature to prevent phishing and other security threats. For chrome, you can download an extension to prevent the browser from denying the request. I encountered this issue while working on WordPress locally.

I use this extension https://chrome.google.com/webstore/detail/ignore-x-frame-headers/gleekbfjekiniecknbkamfmkohkpodhe

addEventListener vs onclick

If you are not too worried about browser support, there is a way to rebind the 'this' reference in the function called by the event. It will normally point to the element that generated the event when the function is executed, which is not always what you want. The tricky part is to at the same time be able to remove the very same event listener, as shown in this example: http://jsfiddle.net/roenbaeck/vBYu3/

/*
    Testing that the function returned from bind is rereferenceable, 
    such that it can be added and removed as an event listener.
*/
function MyImportantCalloutToYou(message, otherMessage) {
    // the following is necessary as calling bind again does 
    // not return the same function, so instead we replace the 
    // original function with the one bound to this instance
    this.swap = this.swap.bind(this); 
    this.element = document.createElement('div');
    this.element.addEventListener('click', this.swap, false);
    document.body.appendChild(this.element);
}
MyImportantCalloutToYou.prototype = {
    element: null,
    swap: function() {
        // now this function can be properly removed 
        this.element.removeEventListener('click', this.swap, false);           
    }
}

The code above works well in Chrome, and there's probably some shim around making "bind" compatible with other browsers.

removing table border

Please try to add this into inside the table tag.

border="0" cellspacing="0" cellpadding="0"

<table  border="0" cellspacing="0" cellpadding="0">
...
</table>

Reading integers from binary file in Python

The read method returns a sequence of bytes as a string. To convert from a string byte-sequence to binary data, use the built-in struct module: http://docs.python.org/library/struct.html.

import struct

print(struct.unpack('i', fin.read(4)))

Note that unpack always returns a tuple, so struct.unpack('i', fin.read(4))[0] gives the integer value that you are after.

You should probably use the format string '<i' (< is a modifier that indicates little-endian byte-order and standard size and alignment - the default is to use the platform's byte ordering, size and alignment). According to the BMP format spec, the bytes should be written in Intel/little-endian byte order.

google chrome extension :: console.log() from background page?

You can open the background page's console if you click on the "background.html" link in the extensions list.

To access the background page that corresponds to your extensions open Settings / Extensions or open a new tab and enter chrome://extensions. You will see something like this screenshot.

Chrome extensions dialogue

Under your extension click on the link background page. This opens a new window. For the context menu sample the window has the title: _generated_background_page.html.

Tree implementation in Java (root, parents and children)

Here is my implementation in java for your requirement. In the treeNode class i used generic array to store the tree data. we can also use arraylist or dynamic array to store the tree value.

public class TreeNode<T> {
   private T value = null;
   private TreeNode[] childrens = new TreeNode[100];
   private int childCount = 0;

    TreeNode(T value) {
        this.value = value;
    }

    public TreeNode addChild(T value) {
        TreeNode newChild = new TreeNode(value, this);
        childrens[childCount++] = newChild;
        return newChild;
    }

    static void traverse(TreeNode obj) {
        if (obj != null) {
            for (int i = 0; i < obj.childCount; i++) {
                System.out.println(obj.childrens[i].value);
                traverse(obj.childrens[i]);
            }
        }
        return;
    }

    void printTree(TreeNode obj) {
        System.out.println(obj.value);
        traverse(obj);
    }
}

And the client class for the above implementation.

public class Client {
    public static void main(String[] args) {
        TreeNode menu = new TreeNode("Menu");
        TreeNode item = menu.addChild("Starter");
            item = item.addChild("Veg");
                item.addChild("Paneer Tikka");
                item.addChild("Malai Paneer Tikka");
            item = item.addChild("Non-veg");
                item.addChild("Chicken Tikka");
                item.addChild("Malai Chicken Tikka");
        item = menu.addChild("Main Course");
            item = item.addChild("Veg");
                item.addChild("Mili Juli Sabzi");
                item.addChild("Aloo Shimla Mirch");
            item = item.addChild("Non-veg");
                item.addChild("Chicken Do Pyaaza");
                item.addChild("Chicken Chettinad");
        item = menu.addChild("Desserts");
                item = item.addChild("Cakes");
                        item.addChild("Black Forest");
                        item.addChild("Black Current");
                item = item.addChild("Ice Creams");
                        item.addChild("chocolate");
                        item.addChild("Vanilla");
        menu.printTree(menu);
    }
}

OUTPUT

Menu                                                                     
Starter                                                                 
Veg                                                                
Paneer Tikka                                                        
Malai Paneer Tikka                                                    
Non-veg                                                              
Chicken Tikka                                                      
Malai Chicken Tikka                                                 
Main Course                                                      
Veg                                                             
Mili Juli Sabzi                                                   
Aloo Shimla Mirch                                                  
Non-veg                                                               
Chicken Do Pyaaza                                                   
Chicken Chettinad                                                    
Desserts                                                         
Cakes                                                            
Black Forest                                                     
Black Current                                                   
Ice Creams                                                      
chocolate                                                       
Vanilla           

How to delete selected text in the vi editor

If you want to remove all lines in a file from your current line number, use dG, it will delete all lines (shift g) mean end of file

build-impl.xml:1031: The module has not been deployed

Start your IDE with administrative privilege( Windows: right click and run as admin), so that it has read write access to tomact folder for deployment. It worked for me.

Convert double to float in Java

To answer your query on "How to convert 2.3423424666767E13 to 23423424666767"

You can use a decimal formatter for formatting decimal numbers.

     double d = 2.3423424666767E13;
     DecimalFormat decimalFormat = new DecimalFormat("#");
     System.out.println(decimalFormat.format(d));

Output : 23423424666767

Angularjs ng-model doesn't work inside ng-if

The ng-if directive, like other directives creates a child scope. See the script below (or this jsfiddle)

_x000D_
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.0rc1/angular.min.js"></script>_x000D_
_x000D_
<script>_x000D_
    function main($scope) {_x000D_
        $scope.testa = false;_x000D_
        $scope.testb = false;_x000D_
        $scope.testc = false;_x000D_
        $scope.obj = {test: false};_x000D_
    }_x000D_
</script>_x000D_
_x000D_
<div ng-app >_x000D_
    <div ng-controller="main">_x000D_
        _x000D_
        Test A: {{testa}}<br />_x000D_
        Test B: {{testb}}<br />_x000D_
        Test C: {{testc}}<br />_x000D_
        {{obj.test}}_x000D_
        _x000D_
        <div>_x000D_
            testa (without ng-if): <input type="checkbox" ng-model="testa" />_x000D_
        </div>_x000D_
        <div ng-if="!testa">_x000D_
            testb (with ng-if): <input type="checkbox" ng-model="testb" /> {{testb}}_x000D_
        </div>_x000D_
        <div ng-if="!someothervar">_x000D_
            testc (with ng-if): <input type="checkbox" ng-model="testc" />_x000D_
        </div>_x000D_
        <div ng-if="!someothervar">_x000D_
            object (with ng-if): <input type="checkbox" ng-model="obj.test" />_x000D_
        </div>_x000D_
        _x000D_
    </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

So, your checkbox changes the testb inside of the child scope, but not the outer parent scope.

Note, that if you want to modify the data in the parent scope, you'll need to modify the internal properties of an object like in the last div that I added.

Get list of data-* attributes using javascript / jQuery

or convert gilly3's excellent answer to a jQuery method:

$.fn.info = function () {
    var data = {};
    [].forEach.call(this.get(0).attributes, function (attr) {
        if (/^data-/.test(attr.name)) {
            var camelCaseName = attr.name.substr(5).replace(/-(.)/g, function ($0, $1) {
                return $1.toUpperCase();
            });
            data[camelCaseName] = attr.value;
        }
    });
    return data;
}

Using: $('.foo').info();

Python 3.6 install win32api?

Information provided by @Gord

As of September 2019 pywin32 is now available from PyPI and installs the latest version (currently version 224). This is done via the pip command

pip install pywin32

If you wish to get an older version the sourceforge link below would probably have the desired version, if not you can use the command, where xxx is the version you require, e.g. 224

pip install pywin32==xxx

This differs to the pip command below as that one uses pypiwin32 which currently installs an older (namely 223)

Browsing the docs I see no reason for these commands to work for all python3.x versions, I am unsure on python2.7 and below so you would have to try them and if they do not work then the solutions below will work.


Probably now undesirable solutions but certainly still valid as of September 2019

There is no version of specific version ofwin32api. You have to get the pywin32module which currently cannot be installed via pip. It is only available from this link at the moment.

https://sourceforge.net/projects/pywin32/files/pywin32/Build%20220/

The install does not take long and it pretty much all done for you. Just make sure to get the right version of it depending on your python version :)


EDIT

Since I posted my answer there are other alternatives to downloading the win32api module.

It is now available to download through pip using this command;

pip install pypiwin32

Also it can be installed from this GitHub repository as provided in comments by @Heath

Spring 3 MVC accessing HttpRequest from controller

Spring MVC will give you the HttpRequest if you just add it to your controller method signature:

For instance:

/**
 * Generate a PDF report...
 */
@RequestMapping(value = "/report/{objectId}", method = RequestMethod.GET)
public @ResponseBody void generateReport(
        @PathVariable("objectId") Long objectId, 
        HttpServletRequest request, 
        HttpServletResponse response) {

    // ...
    // Here you can use the request and response objects like:
    // response.setContentType("application/pdf");
    // response.getOutputStream().write(...);

}

As you see, simply adding the HttpServletRequest and HttpServletResponse objects to the signature makes Spring MVC to pass those objects to your controller method. You'll want the HttpSession object too.

EDIT: It seems that HttpServletRequest/Response are not working for some people under Spring 3. Try using Spring WebRequest/WebResponse objects as Eduardo Zola pointed out.

I strongly recommend you to have a look at the list of supported arguments that Spring MVC is able to auto-magically inject to your handler methods.

How to set bootstrap navbar active class with Angular JS?

This did the trick for me:

  var domain = '{{ DOMAIN }}'; // www.example.com or dev.example.com
  var domain_index =  window.location.href.indexOf(domain);
  var long_app_name = window.location.href.slice(domain_index+domain.length+1); 
  // this turns http://www.example.com/whatever/whatever to whatever/whatever
  app_name = long_app_name.slice(0, long_app_name.indexOf('/')); 
  //now you are left off with just the first whatever which is usually your app name

then you use jquery(works with angular too) to add class active

$('nav a[href*="' + app_name+'"]').closest('li').addClass('active');

and of course the css:

.active{background:red;}

this works if you have your html like this:

<ul><li><a href="/ee">ee</a></li><li><a href="/dd">dd</a></li></ul>

this will atumatically add class active using the page url and color your background to red if your in www.somesite.com/ee thaen ee is the 'app' and it will be active

ADB Install Fails With INSTALL_FAILED_TEST_ONLY

None of the previous post solve my issue. Here is what's happening with me:
I normally load the app from android studio by clicking on the "Run" button. When you do this, android would create an app that's good for debug but not for install. If you try to install using:

adb install -r yourapk

you will get a message that says:

Failure [INSTALL_FAILED_TEST_ONLY]

When this happens, you will need to rebuilt the apk by first clean the build, then select Build->Build APK. See the image bellow:

build android apk

This APK is ready to be installed either through adb install command or any other methods

Hope this helps

David

How to make the background DIV only transparent using CSS

It's not possible, opacity is inherited by child nodes and you can't avoid this. To have only the parent transparent, you have to play with positioning (absolute) of the elements and their z-index

How to get system time in Java without creating a new Date

As jzd says, you can use System.currentTimeMillis. If you need it in a Date object but don't want to create a new Date object, you can use Date.setTime to reuse an existing Date object. Personally I hate the fact that Date is mutable, but maybe it's useful to you in this particular case. Similarly, Calendar has a setTimeInMillis method.

If possible though, it would probably be better just to keep it as a long. If you only need a timestamp, effectively, then that would be the best approach.

Target a css class inside another css class

I use div instead of tables and am able to target classes within the main class, as below:

CSS

.main {
    .width: 800px;
    .margin: 0 auto;
    .text-align: center;
}
.main .table {
    width: 80%;
}
.main .row {
   / ***something ***/
}
.main .column {
    font-size: 14px;
    display: inline-block;
}
.main .left {
    width: 140px;
    margin-right: 5px;
    font-size: 12px;
}
.main .right {
    width: auto;
    margin-right: 20px;
    color: #fff;
    font-size: 13px;
    font-weight: normal;
}

HTML

<div class="main">
    <div class="table">
        <div class="row">
            <div class="column left">Swing Over Bed</div>
            <div class="column right">650mm</div>
            <div class="column left">Swing In Gap</div>
            <div class="column right">800mm</div>
        </div>
    </div>
</div>

If you want to style a particular "cell" exclusively you can use another sub-class or the id of the div e.g:

.main #red { color: red; }

<div class="main">
    <div class="table">
        <div class="row">
            <div id="red" class="column left">Swing Over Bed</div>
            <div class="column right">650mm</div>
            <div class="column left">Swing In Gap</div>
            <div class="column right">800mm</div>
        </div>
    </div>
</div>

How can I lock a file using java (if possible)

Use this for unix if you are transferring using winscp or ftp:

public static void isFileReady(File entry) throws Exception {
        long realFileSize = entry.length();
        long currentFileSize = 0;
        do {
            try (FileInputStream fis = new FileInputStream(entry);) {
                currentFileSize = 0;
                while (fis.available() > 0) {
                    byte[] b = new byte[1024];
                    int nResult = fis.read(b);
                    currentFileSize += nResult;
                    if (nResult == -1)
                        break;
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            System.out.println("currentFileSize=" + currentFileSize + ", realFileSize=" + realFileSize);
        } while (currentFileSize != realFileSize);
    }

Is key-value observation (KVO) available in Swift?

In addition to Rob's answer. That class must inherit from NSObject, and we have 3 ways to trigger property change

Use setValue(value: AnyObject?, forKey key: String) from NSKeyValueCoding

class MyObjectToObserve: NSObject {
    var myDate = NSDate()
    func updateDate() {
        setValue(NSDate(), forKey: "myDate")
    }
}

Use willChangeValueForKey and didChangeValueForKey from NSKeyValueObserving

class MyObjectToObserve: NSObject {
    var myDate = NSDate()
    func updateDate() {
        willChangeValueForKey("myDate")
        myDate = NSDate()
        didChangeValueForKey("myDate")
    }
}

Use dynamic. See Swift Type Compatibility

You can also use the dynamic modifier to require that access to members be dynamically dispatched through the Objective-C runtime if you’re using APIs like key–value observing that dynamically replace the implementation of a method.

class MyObjectToObserve: NSObject {
    dynamic var myDate = NSDate()
    func updateDate() {
        myDate = NSDate()
    }
}

And property getter and setter is called when used. You can verify when working with KVO. This is an example of computed property

class MyObjectToObserve: NSObject {
    var backing: NSDate = NSDate()
    dynamic var myDate: NSDate {
        set {
            print("setter is called")
            backing = newValue
        }
        get {
            print("getter is called")
            return backing
        }
    }
}

Remove menubar from Electron app

Use this:

mainWindow = new BrowserWindow({width: 640, height: 360})
mainWindow.setMenuBarVisibility(false)

Reference: https://github.com/electron/electron/issues/1415

I tried mainWindow.setMenu(null), but it didn't work.

How to add Google Maps Autocomplete search box?

for me work this:

_x000D_
_x000D_
<input type="text"required id="autocomplete">_x000D_
_x000D_
<script>_x000D_
function initAutocomplete() {_x000D_
   new google.maps.places.Autocomplete(_x000D_
          (document.getElementById('autocomplete')),_x000D_
          {types: ['geocode']}_x000D_
   );_x000D_
}_x000D_
</script>_x000D_
<script src="https://maps.googleapis.com/maps/api/js?key=&libraries=places&callback=initAutocomplete"_x000D_
                async defer></script>
_x000D_
_x000D_
_x000D_

How do I iterate and modify Java Sets?

I don't like very much iterator's semantic, please consider this as an option. It's also safer as you publish less of your internal state

private Map<String, String> JSONtoMAP(String jsonString) {

    JSONObject json = new JSONObject(jsonString);
    Map<String, String> outMap = new HashMap<String, String>();

    for (String curKey : (Set<String>) json.keySet()) {
        outMap.put(curKey, json.getString(curKey));
    }

    return outMap;

}

Proper way to declare custom exceptions in modern Python?

A really simple approach:

class CustomError(Exception):
    pass

raise CustomError("Hmm, seems like this was custom coded...")

Or, have the error raise without printing __main__ (may look cleaner and neater):

class CustomError(Exception):
    __module__ = Exception.__module__

raise CustomError("Improved CustomError!")

What is the difference between UTF-8 and ISO-8859-1?

From another perspective, files that both unicode and ascii encodings fail to read because they have a byte 0xc0 in them, seem to get read by iso-8859-1 properly. The caveat is that the file shouldn't have unicode characters in it of course.

sqlplus statement from command line

I assume this is *nix?

Use "here document":

sqlplus -s user/pass <<+EOF
select 1 from dual;
+EOF

EDIT: I should have tried your second example. It works, too (even in Windows, sans ticks):

$ echo 'select 1 from dual;'|sqlplus -s user/pw

         1
----------
         1


$

Sum columns with null values in oracle

In some cases, nvl(sum(column_name),0) is also required. You may want to consider your scenarios.

For example, I am trying to fetch the sum of a particular column, from a particular table based on certain conditions. Based on the conditions,

  1. one or more rows exist in the table. In this case I want the sum.
  2. rows do not exist. In this case I want 0.

If you use sum(nvl(column_name,0)) here, it would give you null. What you might want is nvl(sum(column_name),0).

This may be required especially when you are passing this result to, say, java, have the datatype as number there because then this will not require special null handling.

jquery - disable click

Use off() method after click event is triggered to disable element for the further click.

$('#clickElement').off('click');

Is there any advantage of using map over unordered_map in case of trivial keys?

I was intrigued by the answer from @Jerry Coffin, which suggested that the ordered map would exhibit performance increases on long strings, after some experimentation (which can be downloaded from pastebin), I've found that this seems to hold true only for collections of random strings, when the map is initialised with a sorted dictionary (which contain words with considerable amounts of prefix-overlap), this rule breaks down, presumably because of the increased tree depth necessary to retrieve value. The results are shown below, the 1st number column is insert time, 2nd is fetch time.

g++ -g -O3 --std=c++0x   -c -o stdtests.o stdtests.cpp
g++ -o stdtests stdtests.o
gmurphy@interloper:HashTests$ ./stdtests
# 1st number column is insert time, 2nd is fetch time
 ** Integer Keys ** 
 unordered:      137      15
   ordered:      168      81
 ** Random String Keys ** 
 unordered:       55      50
   ordered:       33      31
 ** Real Words Keys ** 
 unordered:      278      76
   ordered:      516     298

When 1 px border is added to div, Div size increases, Don't want to do that

I usually use padding to resolve this issue. The padding will be added when border disappears and removed when border appears. Sample code:

.good-border {
  padding: 1px;
}

.good-border:hover {
  padding: 0px;
  border: 1px solid blue;
}

enter image description here

View my full sample code on JSFiddle: https://jsfiddle.net/3t7vyebt/4/

How can I create a link to a local file on a locally-run web page?

Janky at best

<a href="file://///server/folders/x/x/filename.ext">right click </a></td>

and then right click, select "copy location" option, and then paste into url.

Is there a color code for transparent in HTML?

Here, instead of making navigation bar transparent, remove any color attributes from the navigation bar to make the background visible.

Strangely, I came across this thinking that I needed a transparent color, but all I needed is to remove the color attributes.

.some-class{
    background-color: #fafafa; 
}

to

.some-class{
}

How to add/subtract time (hours, minutes, etc.) from a Pandas DataFrame.Index whos objects are of type datetime.time?

Liam's link looks great, but also check out pandas.Timedelta - looks like it plays nicely with NumPy's and Python's time deltas.

https://pandas.pydata.org/pandas-docs/stable/timedeltas.html

pd.date_range('2014-01-01', periods=10) + pd.Timedelta(days=1)

How to split a comma separated string and process in a loop using JavaScript

Like this:

var str = 'Hello, World, etc';
var myarray = str.split(',');

for(var i = 0; i < myarray.length; i++)
{
   console.log(myarray[i]);
}

How do I overload the square-bracket operator in C#?

public class CustomCollection : List<Object>
{
    public Object this[int index]
    {
        // ...
    }
}

Detect if a Form Control option button is selected in VBA

You should remove .Value from all option buttons because option buttons don't hold the resultant value, the option group control does. If you omit .Value then the default interface will report the option button status, as you are expecting. You should write all relevant code under commandbutton_click events because whenever the commandbutton is clicked the option button action will run.

If you want to run action code when the optionbutton is clicked then don't write an if loop for that.

EXAMPLE:

Sub CommandButton1_Click
    If OptionButton1 = true then
        (action code...)
    End if
End sub

Sub OptionButton1_Click   
    (action code...)
End sub

How can I create Min stl priority_queue?

In C++11 you could also create an alias for convenience:

template<class T> using min_heap = priority_queue<T, std::vector<T>, std::greater<T>>;

And use it like this:

min_heap<int> my_heap;

Spring Boot + JPA : Column name annotation ignored

I also tried all the above and nothing works. I got field called "gunName" in DB and i couldn't handle this, till i used example below:

@Column(name="\"gunName\"")
public String gunName;

with properties:

spring.jpa.hibernate.naming.implicit-strategy=org.hibernate.boot.model.naming.ImplicitNamingStrategyLegacyJpaImpl
spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl

also see this: https://stackoverflow.com/a/35708531

C Linking Error: undefined reference to 'main'

You are overwriting your object file runexp.o by running this command :

 gcc -o runexp.o scd.o data_proc.o -lm -fopenmp

In fact, the -o is for the output file. You need to run :

gcc -o runexp.out runexp.o scd.o data_proc.o -lm -fopenmp

runexp.out will be you binary file.

Simple proof that GUID is not unique

But do you have to be sure you have a duplicate, or do you only care if there can be a duplicate. To be sure that you have two people with the same birthday, you need 366 people (not counting leap year). For there to be a greater than 50% chance of having two people with the same birthday you only need 23 people. That's the birthday problem.

If you have 32 bits, you only need 77,163 values to have a greater than 50% chance of a duplicate. Try it out:

Random baseRandom = new Random(0);

int DuplicateIntegerTest(int interations)
{
    Random r = new Random(baseRandom.Next());
    int[] ints = new int[interations];
    for (int i = 0; i < ints.Length; i++)
    {
        ints[i] = r.Next();
    }
    Array.Sort(ints);
    for (int i = 1; i < ints.Length; i++)
    {
        if (ints[i] == ints[i - 1])
            return 1;
    }
    return 0;
}

void DoTest()
{
    baseRandom = new Random(0);
    int count = 0;
    int duplicates = 0;
    for (int i = 0; i < 1000; i++)
    {
        count++;
        duplicates += DuplicateIntegerTest(77163);
    }
    Console.WriteLine("{0} iterations had {1} with duplicates", count, duplicates);
}

1000 iterations had 737 with duplicates

Now 128 bits is a lot, so you are still talking a large number of items still giving you a low chance of collision. You would need the following number of records for the given odds using an approximation:

  • 0.8 billion billion for a 1/1000 chance of a collision occurring
  • 21.7 billion billion for 50% chance of a collision occurring
  • 39.6 billion billion for 90% chance of a collision occurring

There are about 1E14 emails sent per year so it would be about 400,000 years at this level before you would have a 90% chance of having two with the same GUID, but that is a lot different than saying you need to run a computer 83 billion times the age of the universe or that the sun would go cold before finding a duplicate.

What is the difference between const and readonly in C#?

Just to add, readonly for reference types only makes the reference read only not the values. For example:

public class Const_V_Readonly
{
  public const int I_CONST_VALUE = 2;
  public readonly char[] I_RO_VALUE = new Char[]{'a', 'b', 'c'};

  public UpdateReadonly()
  {
     I_RO_VALUE[0] = 'V'; //perfectly legal and will update the value
     I_RO_VALUE = new char[]{'V'}; //will cause compiler error
  }
}

Adding POST parameters before submit

You could do an ajax call.

That way, you would be able to populate the POST array yourself through the ajax 'data: ' parameter

var params = {
  url: window.location.pathname,
  time: new Date().getTime(), 
};


$.ajax({
  method: "POST",
  url: "your/script.php",
  data: params
});

Convert number to varchar in SQL with formatting

RIGHT('00' + CONVERT(VARCHAR, MyNumber), 2)

Be warned that this will cripple numbers > 99. You might want to factor in that possibility.

How to backup MySQL database in PHP?

Try out following example of using SELECT INTO OUTFILE query for creating table backup. This will only backup a particular table.

<?php
   $dbhost = 'localhost:3036';
   $dbuser = 'root';
   $dbpass = 'rootpassword';

   $conn = mysql_connect($dbhost, $dbuser, $dbpass);

   if(! $conn ) {
      die('Could not connect: ' . mysql_error());
   }

   $table_name = "employee";
   $backup_file  = "/tmp/employee.sql";
   $sql = "SELECT * INTO OUTFILE '$backup_file' FROM $table_name";

   mysql_select_db('test_db');
   $retval = mysql_query( $sql, $conn );

   if(! $retval ) {
      die('Could not take data backup: ' . mysql_error());
   }

   echo "Backedup  data successfully\n";

   mysql_close($conn);
?>

rbind error: "names do not match previous names"

The names of the first dataframe do not match the names of the second one. Just as the error message says.

> identical(names(xd.small[[1]]), names(xd.small[[2]]) )
[1] FALSE

If you do not care about the names of the 3rd or 4th columns of the second df, you can coerce them to be the same:

> names(xd.small[[1]]) <- names(xd.small[[2]]) 
> identical(names(xd.small[[1]]), names(xd.small[[2]]) )
[1] TRUE

Then things should proceed happily.

Why can't I check if a 'DateTime' is 'Nothing'?

DateTime is a value type, which means it always has some value.

It's like an integer - it can be 0, or 1, or less than zero, but it can never be "nothing".

If you want a DateTime that can take the value Nothing, use a Nullable DateTime.

How to get the current branch name in Git?

You can permanently set up your bash output to show your git-branch name. It is very handy when you work with different branches, no need to type $ git status all the time. Github repo git-aware-prompt .

Open your terminal (ctrl-alt-t) and enter the commands

mkdir ~/.bash
cd ~/.bash
git clone git://github.com/jimeh/git-aware-prompt.git

Edit your .bashrc with sudo nano ~/.bashrc command (for Ubuntu) and add the following to the top:

export GITAWAREPROMPT=~/.bash/git-aware-prompt
source "${GITAWAREPROMPT}/main.sh"

Then paste the code

export PS1="\${debian_chroot:+(\$debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\] \[$txtcyn\]\$git_branch\[$txtred\]\$git_dirty\[$txtrst\]\$ "

at the end of the same file you pasted the installation code into earlier. This will give you the colorized output:enter image description here

Display current date and time without punctuation

Without punctuation (as @Burusothman has mentioned):

current_date_time="`date +%Y%m%d%H%M%S`";
echo $current_date_time;

O/P:

20170115072120

With punctuation:

current_date_time="`date "+%Y-%m-%d %H:%M:%S"`";
echo $current_date_time;

O/P:

2017-01-15 07:25:33

How to extract a substring using regex

You don't need regex for this.

Add apache commons lang to your project (http://commons.apache.org/proper/commons-lang/), then use:

String dataYouWant = StringUtils.substringBetween(mydata, "'");

Submit form after calling e.preventDefault()

Sorry for delay, but I will try to make perfect form :)

I will added Count validation steps and check every time not .val(). Check .length, because I think is better pattern in your case. Of course remove unbind function.

My jsFiddle

Of course source code:

// Prevent form submit if any entrees are missing
$('form').submit(function(e){

    e.preventDefault();

    var formIsValid = true;

    // Count validation steps
    var validationLoop = 0;

    // Cycle through each Attendee Name
    $('[name="atendeename[]"]', this).each(function(index, el){

        // If there is a value
        if ($(el).val().length > 0) {
            validationLoop++;

            // Find adjacent entree input
            var entree = $(el).next('input');

            var entreeValue = entree.val();

            // If entree is empty, don't submit form
            if (entreeValue.length === 0) {
                alert('Please select an entree');
                entree.focus();
                formIsValid = false;
                return false;
            }

        }

    });

    if (formIsValid && validationLoop > 0) {
        alert("Correct Form");
        return true;
    } else {
        return false;
    }

});

Check image width and height before upload with Javascript

The file is just a file, you need to create an image like so:

var _URL = window.URL || window.webkitURL;
$("#file").change(function (e) {
    var file, img;
    if ((file = this.files[0])) {
        img = new Image();
        var objectUrl = _URL.createObjectURL(file);
        img.onload = function () {
            alert(this.width + " " + this.height);
            _URL.revokeObjectURL(objectUrl);
        };
        img.src = objectUrl;
    }
});

Demo: http://jsfiddle.net/4N6D9/1/

I take it you realize this is only supported in a few browsers. Mostly firefox and chrome, could be opera as well by now.

P.S. The URL.createObjectURL() method has been removed from the MediaStream interface. This method has been deprecated in 2013 and superseded by assigning streams to HTMLMediaElement.srcObject. The old method was removed because it is less safe, requiring a call to URL.revokeOjbectURL() to end the stream. Other user agents have either deprecated (Firefox) or removed (Safari) this feature feature.

For more information, please refer here.

How to dynamically load a Python class

module = __import__("my_package/my_module")
the_class = getattr(module, "MyClass")
obj = the_class()

How to install pkg config in windows?

I did this by installing Cygwin64 from this link https://www.cygwin.com/ Then - View Full, Search gcc and scroll down to find pkg-config. Click on icon to select latest version. This worked for me well.

Plotting a list of (x, y) coordinates in python matplotlib

As per this example:

import numpy as np
import matplotlib.pyplot as plt

N = 50
x = np.random.rand(N)
y = np.random.rand(N)

plt.scatter(x, y)
plt.show()

will produce:

enter image description here

To unpack your data from pairs into lists use zip:

x, y = zip(*li)

So, the one-liner:

plt.scatter(*zip(*li))

Serialize form data to JSON

Trying to solve the same problem (validation without getting into complex plugins and libraries), I created jQuery.serializeJSON, that improves serializeArray to support any kind of nested objects.

This plugin got very popular, but in another project I was using Backbone.js, where I would like to write the validation logic in the Backbone.js models. Then I created Backbone.Formwell, which allows you to show the errors returned by the validation method directly in the form.

Detect if checkbox is checked or unchecked in Angular.js ng-change event

The state of the checkbox will be reflected on whatever model you have it bound to, in this case, $scope.answers[item.questID]

How to change the height of a <br>?

I just had this problem, and I got around it by using

<div style="line-height:150%;">
    <br>
</div>

Best practice for localization and globalization of strings and labels

When you’re faced with a problem to solve (and frankly, who isn’t these days?), the basic strategy usually taken by we computer people is called “divide and conquer.” It goes like this:

  • Conceptualize the specific problem as a set of smaller sub-problems.
  • Solve each smaller problem.
  • Combine the results into a solution of the specific problem.

But “divide and conquer” is not the only possible strategy. We can also take a more generalist approach:

  • Conceptualize the specific problem as a special case of a more general problem.
  • Somehow solve the general problem.
  • Adapt the solution of the general problem to the specific problem.

- Eric Lippert

I believe many solutions already exist for this problem in server-side languages such as ASP.Net/C#.

I've outlined some of the major aspects of the problem

  • Issue: We need to load data only for the desired language

    Solution: For this purpose we save data to a separate files for each language

ex. res.de.js, res.fr.js, res.en.js, res.js(for default language)

  • Issue: Resource files for each page should be separated so we only get the data we need

    Solution: We can use some tools that already exist like https://github.com/rgrove/lazyload

  • Issue: We need a key/value pair structure to save our data

    Solution: I suggest a javascript object instead of string/string air. We can benefit from the intellisense from an IDE

  • Issue: General members should be stored in a public file and all pages should access them

    Solution: For this purpose I make a folder in the root of web application called Global_Resources and a folder to store global file for each sub folders we named it 'Local_Resources'

  • Issue: Each subsystems/subfolders/modules member should override the Global_Resources members on their scope

    Solution: I considered a file for each

Application Structure

root/
    Global_Resources/
        default.js
        default.fr.js
    UserManagementSystem/
        Local_Resources/
            default.js
            default.fr.js
            createUser.js
        Login.htm
        CreateUser.htm

The corresponding code for the files:

Global_Resources/default.js

var res = {
    Create : "Create",
    Update : "Save Changes",
    Delete : "Delete"
};

Global_Resources/default.fr.js

var res = {
    Create : "créer",
    Update : "Enregistrer les modifications",
    Delete : "effacer"
};

The resource file for the desired language should be loaded on the page selected from Global_Resource - This should be the first file that is loaded on all the pages.

UserManagementSystem/Local_Resources/default.js

res.Name = "Name";
res.UserName = "UserName";
res.Password = "Password";

UserManagementSystem/Local_Resources/default.fr.js

res.Name = "nom";
res.UserName = "Nom d'utilisateur";
res.Password = "Mot de passe";

UserManagementSystem/Local_Resources/createUser.js

// Override res.Create on Global_Resources/default.js
res.Create = "Create User"; 

UserManagementSystem/Local_Resources/createUser.fr.js

// Override Global_Resources/default.fr.js
res.Create = "Créer un utilisateur";

manager.js file (this file should be load last)

res.lang = "fr";

var globalResourcePath = "Global_Resources";
var resourceFiles = [];

var currentFile = globalResourcePath + "\\default" + res.lang + ".js" ;

if(!IsFileExist(currentFile))
    currentFile = globalResourcePath + "\\default.js" ;
if(!IsFileExist(currentFile)) throw new Exception("File Not Found");

resourceFiles.push(currentFile);

// Push parent folder on folder into folder
foreach(var folder in parent folder of current page)
{
    currentFile = folder + "\\Local_Resource\\default." + res.lang + ".js";

    if(!IsExist(currentFile))
        currentFile = folder + "\\Local_Resource\\default.js";
    if(!IsExist(currentFile)) throw new Exception("File Not Found");

    resourceFiles.push(currentFile);
}

for(int i = 0; i < resourceFiles.length; i++) { Load.js(resourceFiles[i]); }

// Get current page name
var pageNameWithoutExtension = "SomePage";

currentFile = currentPageFolderPath + pageNameWithoutExtension + res.lang + ".js" ;

if(!IsExist(currentFile))
    currentFile = currentPageFolderPath + pageNameWithoutExtension + ".js" ;
if(!IsExist(currentFile)) throw new Exception("File Not Found");

Hope it helps :)

mysql SELECT IF statement with OR

IF(compliment IN('set','Y',1), 'Y', 'N') AS customer_compliment

Will do the job as Buttle Butkus suggested.

Visual Studio 2010 - recommended extensions

WoVS Quick Add Reference

The “Quick Add Reference” extension augments the smart tag that VS shows for unrecognized types giving you a chance to add the corresponding assembly reference for that type plus corresponding “using” clause if needed in a single shot.

How to test if JSON object is empty in Java

obj.length() == 0

is what I would do.

Apache VirtualHost 403 Forbidden

I just spent several hours on this stupid problem

First, change permissions using this in terminal

find htdocs -type f -exec chmod 664 {} + -o -type d -exec chmod 775 {} +

I don't know what the difference is between 664 and 775 I did both 775 like this Also htdocs needs the directory path for instance for me it was

/usr/local/apache2/htdocs 

find htdocs -type f -exec chmod 775 {} + -o -type d -exec chmod 775 {} +

This is the other dumb thing too

make sure that your image src link is your domain name for instance

src="http://www.fakedomain.com/images/photo.png"

Be sure to have

EnableSendfile off in httpd.conf file
EnableMMAP off in httpd.conf file

You edit those using pico in terminal

I also created a directory for images specifically so that when you type in the browser address bar domainname.com/images, you will get a list of photos which can be downloaded and need to be downloaded successfully to indicate image files that are working properly

<Directory /usr/local/apache2/htdocs/images>
AddType images/png .png
</Directory>

And those are the solutions I have tried, now I have functioning images... yay!!!

Onto the next problem(s)

How to use jquery $.post() method to submit form values

Get the value of your textboxes using val() and store them in a variable. Pass those values through $.post. In using the $.Post Submit button you can actually remove the form.

<script>

    username = $("#username").val(); 
    password = $("#password").val();

    $("#post-btn").click(function(){        
        $.post("process.php", { username:username, password:password } ,function(data){
            alert(data);
        });
    });
</script>

How to encrypt/decrypt data in php?

Foreword

Starting with your table definition:

- UserID
- Fname
- Lname
- Email
- Password
- IV

Here are the changes:

  1. The fields Fname, Lname and Email will be encrypted using a symmetric cipher, provided by OpenSSL,
  2. The IV field will store the initialisation vector used for encryption. The storage requirements depend on the cipher and mode used; more about this later.
  3. The Password field will be hashed using a one-way password hash,

Encryption

Cipher and mode

Choosing the best encryption cipher and mode is beyond the scope of this answer, but the final choice affects the size of both the encryption key and initialisation vector; for this post we will be using AES-256-CBC which has a fixed block size of 16 bytes and a key size of either 16, 24 or 32 bytes.

Encryption key

A good encryption key is a binary blob that's generated from a reliable random number generator. The following example would be recommended (>= 5.3):

$key_size = 32; // 256 bits
$encryption_key = openssl_random_pseudo_bytes($key_size, $strong);
// $strong will be true if the key is crypto safe

This can be done once or multiple times (if you wish to create a chain of encryption keys). Keep these as private as possible.

IV

The initialisation vector adds randomness to the encryption and required for CBC mode. These values should be ideally be used only once (technically once per encryption key), so an update to any part of a row should regenerate it.

A function is provided to help you generate the IV:

$iv_size = 16; // 128 bits
$iv = openssl_random_pseudo_bytes($iv_size, $strong);

Example

Let's encrypt the name field, using the earlier $encryption_key and $iv; to do this, we have to pad our data to the block size:

function pkcs7_pad($data, $size)
{
    $length = $size - strlen($data) % $size;
    return $data . str_repeat(chr($length), $length);
}

$name = 'Jack';
$enc_name = openssl_encrypt(
    pkcs7_pad($name, 16), // padded data
    'AES-256-CBC',        // cipher and mode
    $encryption_key,      // secret key
    0,                    // options (not used)
    $iv                   // initialisation vector
);

Storage requirements

The encrypted output, like the IV, is binary; storing these values in a database can be accomplished by using designated column types such as BINARY or VARBINARY.

The output value, like the IV, is binary; to store those values in MySQL, consider using BINARY or VARBINARY columns. If this is not an option, you can also convert the binary data into a textual representation using base64_encode() or bin2hex(), doing so requires between 33% to 100% more storage space.

Decryption

Decryption of the stored values is similar:

function pkcs7_unpad($data)
{
    return substr($data, 0, -ord($data[strlen($data) - 1]));
}

$row = $result->fetch(PDO::FETCH_ASSOC); // read from database result
// $enc_name = base64_decode($row['Name']);
// $enc_name = hex2bin($row['Name']);
$enc_name = $row['Name'];
// $iv = base64_decode($row['IV']);
// $iv = hex2bin($row['IV']);
$iv = $row['IV'];

$name = pkcs7_unpad(openssl_decrypt(
    $enc_name,
    'AES-256-CBC',
    $encryption_key,
    0,
    $iv
));

Authenticated encryption

You can further improve the integrity of the generated cipher text by appending a signature that's generated from a secret key (different from the encryption key) and the cipher text. Before the cipher text is decrypted, the signature is first verified (preferably with a constant-time comparison method).

Example

// generate once, keep safe
$auth_key = openssl_random_pseudo_bytes(32, $strong);

// authentication
$auth = hash_hmac('sha256', $enc_name, $auth_key, true);
$auth_enc_name = $auth . $enc_name;

// verification
$auth = substr($auth_enc_name, 0, 32);
$enc_name = substr($auth_enc_name, 32);
$actual_auth = hash_hmac('sha256', $enc_name, $auth_key, true);

if (hash_equals($auth, $actual_auth)) {
    // perform decryption
}

See also: hash_equals()

Hashing

Storing a reversible password in your database must be avoided as much as possible; you only wish to verify the password rather than knowing its contents. If a user loses their password, it's better to allow them to reset it rather than sending them their original one (make sure that password reset can only be done for a limited time).

Applying a hash function is a one-way operation; afterwards it can be safely used for verification without revealing the original data; for passwords, a brute force method is a feasible approach to uncover it due to its relatively short length and poor password choices of many people.

Hashing algorithms such as MD5 or SHA1 were made to verify file contents against a known hash value. They're greatly optimized to make this verification as fast as possible while still being accurate. Given their relatively limited output space it was easy to build a database with known passwords and their respective hash outputs, the rainbow tables.

Adding a salt to the password before hashing it would render a rainbow table useless, but recent hardware advancements made brute force lookups a viable approach. That's why you need a hashing algorithm that's deliberately slow and simply impossible to optimize. It should also be able to increase the load for faster hardware without affecting the ability to verify existing password hashes to make it future proof.

Currently there are two popular choices available:

  1. PBKDF2 (Password Based Key Derivation Function v2)
  2. bcrypt (aka Blowfish)

This answer will use an example with bcrypt.

Generation

A password hash can be generated like this:

$password = 'my password';
$random = openssl_random_pseudo_bytes(18);
$salt = sprintf('$2y$%02d$%s',
    13, // 2^n cost factor
    substr(strtr(base64_encode($random), '+', '.'), 0, 22)
);

$hash = crypt($password, $salt);

The salt is generated with openssl_random_pseudo_bytes() to form a random blob of data which is then run through base64_encode() and strtr() to match the required alphabet of [A-Za-z0-9/.].

The crypt() function performs the hashing based on the algorithm ($2y$ for Blowfish), the cost factor (a factor of 13 takes roughly 0.40s on a 3GHz machine) and the salt of 22 characters.

Validation

Once you have fetched the row containing the user information, you validate the password in this manner:

$given_password = $_POST['password']; // the submitted password
$db_hash = $row['Password']; // field with the password hash

$given_hash = crypt($given_password, $db_hash);

if (isEqual($given_hash, $db_hash)) {
    // user password verified
}

// constant time string compare
function isEqual($str1, $str2)
{
    $n1 = strlen($str1);
    if (strlen($str2) != $n1) {
        return false;
    }
    for ($i = 0, $diff = 0; $i != $n1; ++$i) {
        $diff |= ord($str1[$i]) ^ ord($str2[$i]);
    }
    return !$diff;
}

To verify a password, you call crypt() again but you pass the previously calculated hash as the salt value. The return value yields the same hash if the given password matches the hash. To verify the hash, it's often recommended to use a constant-time comparison function to avoid timing attacks.

Password hashing with PHP 5.5

PHP 5.5 introduced the password hashing functions that you can use to simplify the above method of hashing:

$hash = password_hash($password, PASSWORD_BCRYPT, ['cost' => 13]);

And verifying:

if (password_verify($given_password, $db_hash)) {
    // password valid
}

See also: password_hash(), password_verify()

How to fire a change event on a HTMLSelectElement if the new value is the same as the old?

You have to add empty option to solve it,

I also can give you one more solution but its up to you that is fine for you or not Because User select default option after selecting other options than jsFunction will be called twice.

<select onChange="jsFunction()" id="selectOpt">
    <option value="1" onclick="jsFunction()">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
</select>

function jsFunction(){
  var myselect = document.getElementById("selectOpt");
  alert(myselect.options[myselect.selectedIndex].value);
}

Sublime text 3. How to edit multiple lines?

Thank you for all answers! I found it! It calls "Column selection (for Sublime)" and "Column Mode Editing (for Notepad++)" https://www.sublimetext.com/docs/3/column_selection.html

Auto-center map with multiple markers in Google Maps API v3

i had a situation where i can't change old code, so added this javascript function to calculate center point and zoom level:

_x000D_
_x000D_
//input_x000D_
var tempdata = ["18.9400|72.8200-19.1717|72.9560-28.6139|77.2090"];_x000D_
_x000D_
function getCenterPosition(tempdata){_x000D_
 var tempLat = tempdata[0].split("-");_x000D_
 var latitudearray = [];_x000D_
 var longitudearray = [];_x000D_
 var i;_x000D_
 for(i=0; i<tempLat.length;i++){_x000D_
  var coordinates = tempLat[i].split("|");_x000D_
  latitudearray.push(coordinates[0]);_x000D_
  longitudearray.push(coordinates[1]);_x000D_
 }_x000D_
 latitudearray.sort(function (a, b) { return a-b; });_x000D_
 longitudearray.sort(function (a, b) { return a-b; });_x000D_
 var latdifferenece = latitudearray[latitudearray.length-1] - latitudearray[0];_x000D_
 var temp = (latdifferenece / 2).toFixed(4) ;_x000D_
 var latitudeMid = parseFloat(latitudearray[0]) + parseFloat(temp);_x000D_
 var longidifferenece = longitudearray[longitudearray.length-1] - longitudearray[0];_x000D_
 temp = (longidifferenece / 2).toFixed(4) ;_x000D_
 var longitudeMid = parseFloat(longitudearray[0]) + parseFloat(temp);_x000D_
 var maxdifference = (latdifferenece > longidifferenece)? latdifferenece : longidifferenece;_x000D_
 var zoomvalue; _x000D_
 if(maxdifference >= 0 && maxdifference <= 0.0037)  //zoom 17_x000D_
  zoomvalue='17';_x000D_
 else if(maxdifference > 0.0037 && maxdifference <= 0.0070)  //zoom 16_x000D_
  zoomvalue='16';_x000D_
 else if(maxdifference > 0.0070 && maxdifference <= 0.0130)  //zoom 15_x000D_
  zoomvalue='15';_x000D_
 else if(maxdifference > 0.0130 && maxdifference <= 0.0290)  //zoom 14_x000D_
  zoomvalue='14';_x000D_
 else if(maxdifference > 0.0290 && maxdifference <= 0.0550)  //zoom 13_x000D_
  zoomvalue='13';_x000D_
 else if(maxdifference > 0.0550 && maxdifference <= 0.1200)  //zoom 12_x000D_
  zoomvalue='12';_x000D_
 else if(maxdifference > 0.1200 && maxdifference <= 0.4640)  //zoom 10_x000D_
  zoomvalue='10';_x000D_
 else if(maxdifference > 0.4640 && maxdifference <= 1.8580)  //zoom 8_x000D_
  zoomvalue='8';_x000D_
 else if(maxdifference > 1.8580 && maxdifference <= 3.5310)  //zoom 7_x000D_
  zoomvalue='7';_x000D_
 else if(maxdifference > 3.5310 && maxdifference <= 7.3367)  //zoom 6_x000D_
  zoomvalue='6';_x000D_
 else if(maxdifference > 7.3367 && maxdifference <= 14.222)  //zoom 5_x000D_
  zoomvalue='5';_x000D_
 else if(maxdifference > 14.222 && maxdifference <= 28.000)  //zoom 4_x000D_
  zoomvalue='4';_x000D_
 else if(maxdifference > 28.000 && maxdifference <= 58.000)  //zoom 3_x000D_
  zoomvalue='3';_x000D_
 else_x000D_
  zoomvalue='1';_x000D_
 return latitudeMid+'|'+longitudeMid+'|'+zoomvalue;_x000D_
}
_x000D_
_x000D_
_x000D_

How do I create directory if it doesn't exist to create a file?

You can use File.Exists to check if the file exists and create it using File.Create if required. Make sure you check if you have access to create files at that location.

Once you are certain that the file exists, you can write to it safely. Though as a precaution, you should put your code into a try...catch block and catch for the exceptions that function is likely to raise if things don't go exactly as planned.

Additional information for basic file I/O concepts.

Get value from text area

Use val():

 if ($("textarea").val()!== "") {
        alert($("textarea").val());
    }

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

You can use find to look for the selected option that is a descendant of the node(s) pointed to by the current jQuery object:

var cur_value = $(this).find('option:selected').text();

Since this is likely an immediate child, I would actually suggest using .children instead:

var cur_value = $(this).children('option:selected').text();

How to increment a pointer address and pointer's value?

checked the program and the results are as,

p++;    // use it then move to next int position
++p;    // move to next int and then use it
++*p;   // increments the value by 1 then use it 
++(*p); // increments the value by 1 then use it
++*(p); // increments the value by 1 then use it
*p++;   // use the value of p then moves to next position
(*p)++; // use the value of p then increment the value
*(p)++; // use the value of p then moves to next position
*++p;   // moves to the next int location then use that value
*(++p); // moves to next location then use that value

Is there a performance difference between a for loop and a for-each loop?

It's always better to use the iterator instead of indexing. This is because iterator is most likely optimzied for the List implementation while indexed (calling get) might not be. For example LinkedList is a List but indexing through its elements will be slower than iterating using the iterator.

Get MIME type from filename extension

Most of the solutions are working but why take so efforts while we also can get mime type very easily. In System.Web assembly, there is method for getting the mime type from file name. eg:

string mimeType = MimeMapping.GetMimeMapping(filename);

Encrypt and Decrypt text with RSA in PHP

Security warning: This code snippet is vulnerable to Bleichenbacher's 1998 padding oracle attack. See this answer for better security.

class MyEncryption
{

    public $pubkey = '...public key here...';
    public $privkey = '...private key here...';

    public function encrypt($data)
    {
        if (openssl_public_encrypt($data, $encrypted, $this->pubkey))
            $data = base64_encode($encrypted);
        else
            throw new Exception('Unable to encrypt data. Perhaps it is bigger than the key size?');

        return $data;
    }

    public function decrypt($data)
    {
        if (openssl_private_decrypt(base64_decode($data), $decrypted, $this->privkey))
            $data = $decrypted;
        else
            $data = '';

        return $data;
    }
}

Better way to revert to a previous SVN revision of a file?

What you're looking for is called a "reverse merge". You should consult the docs regarding the merge function in the SVN book (as luapyad, or more precisely the first commenter on that post, points out). If you're using Tortoise, you can also just go into the log view and right-click and choose "revert changes from this revision" on the one where you made the mistake.

How to get a cross-origin resource sharing (CORS) post request working

If for some reasons while trying to add headers or set control policy you're still getting nowhere you may consider using apache ProxyPass…

For example in one <VirtualHost> that uses SSL add the two following directives:

SSLProxyEngine On
ProxyPass /oauth https://remote.tld/oauth

Make sure the following apache modules are loaded (load them using a2enmod):

  • proxy
  • proxy_connect
  • proxy_http

Obviously you'll have to change your AJAX requests url in order to use the apache proxy…

How to change port for jenkins window service when 8080 is being used

Check in Jenkins.xml and update like below

<arguments>-Xrs -Xmx256m -Dhudson.lifecycle=hudson.lifecycle.WindowsServiceLifecycle -jar "%BASE%\jenkins.war" --httpPort=8090</arguments>

How can I determine the URL that a local Git repository was originally cloned from?

I prefer this one as it is easier to remember:

git config -l

It will list all useful information such as:

user.name=Your Name
[email protected]
core.autocrlf=input
core.repositoryformatversion=0
core.filemode=true
core.bare=false
core.logallrefupdates=true
remote.origin.url=https://github.com/mapstruct/mapstruct-examples
remote.origin.fetch=+refs/heads/*:refs/remotes/origin/*
branch.master.remote=origin
branch.master.merge=refs/heads/master

How to connect wireless network adapter to VMWare workstation?

I also encountered a similar problem. I run Ubuntu 11.04 on VMware on a Windows 7 host OS. Virtual machines can't expose the physical wireless cards. All of that is using a virtualization layer.

Print a list of space-separated elements in Python 3

You can apply the list as separate arguments:

print(*L)

and let print() take care of converting each element to a string. You can, as always, control the separator by setting the sep keyword argument:

>>> L = [1, 2, 3, 4, 5]
>>> print(*L)
1 2 3 4 5
>>> print(*L, sep=', ')
1, 2, 3, 4, 5
>>> print(*L, sep=' -> ')
1 -> 2 -> 3 -> 4 -> 5

Unless you need the joined string for something else, this is the easiest method. Otherwise, use str.join():

joined_string = ' '.join([str(v) for v in L])
print(joined_string)
# do other things with joined_string

Note that this requires manual conversion to strings for any non-string values in L!

yii2 redirect in controller action does not work?

Redirects the browser to the specified URL.

This method adds a "Location" header to the current response. Note that it does not send out the header until send() is called. In a controller action you may use this method as follows:

return Yii::$app->getResponse()->redirect($url);

In other places, if you want to send out the "Location" header immediately, you should use the following code:

Yii::$app->getResponse()->redirect($url)->send();
return;

Focusable EditText inside ListView

Sorry, answered my own question. It may not be the most correct or most elegant solution, but it works for me, and gives a pretty solid user experience. I looked into the code for ListView to see why the two behaviors are so different, and came across this from ListView.java:

    public void setItemsCanFocus(boolean itemsCanFocus) {
        mItemsCanFocus = itemsCanFocus;
        if (!itemsCanFocus) {
            setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS);
        }
    }

So, when calling setItemsCanFocus(false), it's also setting descendant focusability such that no child can get focus. This explains why I couldn't just toggle mItemsCanFocus in the ListView's OnItemSelectedListener -- because the ListView was then blocking focus to all children.

What I have now:

<ListView
    android:id="@android:id/list" 
    android:layout_height="match_parent" 
    android:layout_width="match_parent"
    android:descendantFocusability="beforeDescendants"
    />

I use beforeDescendants because the selector will only be drawn when the ListView itself (not a child) has focus, so the default behavior needs to be that the ListView takes focus first and draws selectors.

Then in the OnItemSelectedListener, since I know which header view I want to override the selector (would take more work to dynamically determine if any given position contains a focusable view), I can change descendant focusability, and set focus on the EditText. And when I navigate out of that header, change it back it again.

public void onItemSelected(AdapterView<?> listView, View view, int position, long id)
{
    if (position == 1)
    {
        // listView.setItemsCanFocus(true);

        // Use afterDescendants, because I don't want the ListView to steal focus
        listView.setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS);
        myEditText.requestFocus();
    }
    else
    {
        if (!listView.isFocused())
        {
            // listView.setItemsCanFocus(false);

            // Use beforeDescendants so that the EditText doesn't re-take focus
            listView.setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS);
            listView.requestFocus();
        }
    }
}

public void onNothingSelected(AdapterView<?> listView)
{
    // This happens when you start scrolling, so we need to prevent it from staying
    // in the afterDescendants mode if the EditText was focused 
    listView.setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS);
}

Note the commented-out setItemsCanFocus calls. With those calls, I got the correct behavior, but setItemsCanFocus(false) caused focus to jump from the EditText, to another widget outside of the ListView, back to the ListView and displayed the selector on the next selected item, and that jumping focus was distracting. Removing the ItemsCanFocus change, and just toggling descendant focusability got me the desired behavior. All items draw the selector as normal, but when getting to the row with the EditText, it focused on the text field instead. Then when continuing out of that EditText, it started drawing the selector again.

How to insert table values from one database to another database?

If both the tables have the same schema then use this query: insert into database_name.table_name select * from new_database_name.new_table_name where='condition'

Replace database_name with the name of your 1st database and table_name with the name of table you want to copy from also replace new_database_name with the name of your other database where you wanna copy and new_table_name is the name of the table.

How to remove duplicate objects in a List<MyObject> without equals/hashcode?

It is recommended to override equals() and hashCode() to work with hash-based collections, including HashMap, HashSet, and Hashtable, So doing this you can easily remove duplicates by initiating HashSet object with Blog list.

List<Blog> blogList = getBlogList();
Set<Blog> noDuplication = new HashSet<Blog>(blogList);

But Thanks to Java 8 which have very cleaner version to do this as you mentioned you can not change code to add equals() and hashCode()

Collection<Blog> uniqueBlogs = getUniqueBlogList(blogList);

private Collection<Blog> getUniqueBlogList(List<Blog> blogList) {
    return blogList.stream()
            .collect(Collectors.toMap(createUniqueKey(), Function.identity(), (blog1, blog2) -> blog1))
            .values();
}
List<Blog> updatedBlogList = new ArrayList<>(uniqueBlogs);

Third parameter of Collectors.toMap() is merge Function (functional interface) used to resolve collisions between values associated with the same key.

Windows error 2 occured while loading the Java VM

In cmd

C:\Users\Downloads>install.exe LAX_VM "C:\Program Files\Java\jdk1.8.0_60\bin\java.exe"

Normalize data in pandas

In [92]: df
Out[92]:
           a         b          c         d
A  -0.488816  0.863769   4.325608 -4.721202
B -11.937097  2.993993 -12.916784 -1.086236
C  -5.569493  4.672679  -2.168464 -9.315900
D   8.892368  0.932785   4.535396  0.598124

In [93]: df_norm = (df - df.mean()) / (df.max() - df.min())

In [94]: df_norm
Out[94]:
          a         b         c         d
A  0.085789 -0.394348  0.337016 -0.109935
B -0.463830  0.164926 -0.650963  0.256714
C -0.158129  0.605652 -0.035090 -0.573389
D  0.536170 -0.376229  0.349037  0.426611

In [95]: df_norm.mean()
Out[95]:
a   -2.081668e-17
b    4.857226e-17
c    1.734723e-17
d   -1.040834e-17

In [96]: df_norm.max() - df_norm.min()
Out[96]:
a    1
b    1
c    1
d    1

Regex Email validation

I've created a FormValidationUtils class to validate email:

public static class FormValidationUtils
{
    const string ValidEmailAddressPattern = "^[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,6}$";

    public static bool IsEmailValid(string email)
    {
        var regex = new Regex(ValidEmailAddressPattern, RegexOptions.IgnoreCase);
        return regex.IsMatch(email);
    }
}

How to make the python interpreter correctly handle non-ASCII characters in string operations?

For what it was worth, my character set was utf-8 and I had included the classic "# -*- coding: utf-8 -*-" line.

However, I discovered that I didn't have Universal Newlines when reading this data from a webpage.

My text had two words, separated by "\r\n". I was only splitting on the \n and replacing the "\n".

Once I looped through and saw the character set in question, I realized the mistake.

So, it could also be within the ASCII character set, but a character that you didn't expect.

Differences between cookies and sessions?

A lot contributions on this thread already, just summarize a sequence diagram to illustrate it in another way.

enter image description here

The is also a good link about this topic, https://web.stanford.edu/~ouster/cgi-bin/cs142-fall10/lecture.php?topic=cookie

Changing button color programmatically

I believe you want bgcolor. Something like this:

document.getElementById("button").bgcolor="#ffffff";

Here are a couple of demos that might help:

Background Color

Background Color Changer

How to start nginx via different port(other than 80)

If you are experiencing this problem when using Docker be sure to map the correct port numbers. If you map port 81:80 when running docker (or through docker-compose.yml), your nginx must listen on port 80 not 81, because docker does the mapping already.

I spent quite some time on this issue myself, so hope it can be to some help for future googlers.

How to declare Return Types for Functions in TypeScript

You can read more about function types in the language specification in sections 3.5.3.5 and 3.5.5.

The TypeScript compiler will infer types when it can, and this is done you do not need to specify explicit types. so for the greeter example, greet() returns a string literal, which tells the compiler that the type of the function is a string, and no need to specify a type. so for instance in this sample, I have the greeter class with a greet method that returns a string, and a variable that is assigned to number literal. the compiler will infer both types and you will get an error if you try to assign a string to a number.

class Greeter {
    greet() {
        return "Hello, ";  // type infered to be string
    }
} 

var x = 0; // type infered to be number

// now if you try to do this, you will get an error for incompatable types
x = new Greeter().greet(); 

Similarly, this sample will cause an error as the compiler, given the information, has no way to decide the type, and this will be a place where you have to have an explicit return type.

function foo(){
    if (true)
        return "string"; 
    else 
        return 0;
}

This, however, will work:

function foo() : any{
    if (true)
        return "string"; 
    else 
        return 0;
}

Passing null arguments to C# methods

Starting from C# 2.0, you can use the nullable generic type Nullable, and in C# there is a shorthand notation the type followed by ?

e.g.

private void Example(int? arg1, int? arg2)
{
    if(arg1 == null)
    {
        //do something
    }
    if(arg2 == null)
    {
        //do something else
    }
}

Android - Spacing between CheckBox and text

Instead of adjusting the text for Checkbox, I have done following thing and it worked for me for all the devices. 1) In XML, add checkbox and a textview to adjacent to one after another; keeping some distance. 2) Set checkbox text size to 0sp. 3) Add relative text to that textview next to the checkbox.

How to hide navigation bar permanently in android activity?

Its a security issue: https://stackoverflow.com/a/12605313/1303691

therefore its not possible to hide the Navigation on a tablet permanently with one single call at the beginning of the view creation. It will be hidden, but it will pop up when touching the Screen. So just the second touch to your screen can cause a onClickEvent on your layout. Therefore you need to intercept this call, but i haven't managed it yet, i will update my answer when i found it out. Or do you now the answer already?

How do I get Flask to run on port 80?

This is the only solution that worked for me on Ubuntu-18.

Inside the file app.py , use:

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=80)

The code above will give the same permission error unless sudo is used to run it:

sudo python3 app.py

How to get a context in a recycler view adapter

First globally declare

Context mContext;

pass context with the constructor, by modifying it.

public FeedAdapter(List<Post> myDataset, Context context) {
    mDataset = myDataset;
    this.mContext = context;
}

then use the mContext whereever you need it

How to remove line breaks (no characters!) from the string?

Alternative built-in: trim()

trim — Strip whitespace (or other characters) from the beginning and end of a string
Description ¶
trim ( string $str [, string $character_mask = " \t\n\r\0\x0B" ] ) : string

This function returns a string with whitespace stripped from the beginning and end of str.
Without the second parameter, trim() will strip these characters:

    " " (ASCII 32 (0x20)), an ordinary space.
    "\t" (ASCII 9 (0x09)), a tab.
    "\n" (ASCII 10 (0x0A)), a new line (line feed).
    "\r" (ASCII 13 (0x0D)), a carriage return.
    "\0" (ASCII 0 (0x00)), the NUL-byte.
    "\x0B" (ASCII 11 (0x0B)), a vertical tab.

It's there to remove line breaks from different kinds of text files, but does not handle html.

java.lang.ClassNotFoundException: org.eclipse.core.runtime.adaptor.EclipseStarter

I had the same issue.

just removed all my worskspace:

C:\Users\<name>\.<eclipse similar name>

Unique on a dataframe with only selected columns

Here are a couple dplyr options that keep non-duplicate rows based on columns id and id2:

library(dplyr)                                        
df %>% distinct(id, id2, .keep_all = TRUE)
df %>% group_by(id, id2) %>% filter(row_number() == 1)
df %>% group_by(id, id2) %>% slice(1)

Return row number(s) for a particular value in a column in a dataframe

Use which(mydata_2$height_chad1 == 2585)

Short example

df <- data.frame(x = c(1,1,2,3,4,5,6,3),
                 y = c(5,4,6,7,8,3,2,4))
df
  x y
1 1 5
2 1 4
3 2 6
4 3 7
5 4 8
6 5 3
7 6 2
8 3 4

which(df$x == 3)
[1] 4 8

length(which(df$x == 3))
[1] 2

count(df, vars = "x")
  x freq
1 1    2
2 2    1
3 3    2
4 4    1
5 5    1
6 6    1

df[which(df$x == 3),]
  x y
4 3 7
8 3 4

As Matt Weller pointed out, you can use the length function. The count function in plyr can be used to return the count of each unique column value.

Scope 'session' is not active for the current thread; IllegalStateException: No thread-bound request found

The problem is not in your Spring annotations but your design pattern. You mix together different scopes and threads:

  • singleton
  • session (or request)
  • thread pool of jobs

The singleton is available anywhere, it is ok. However session/request scope is not available outside a thread that is attached to a request.

Asynchronous job can run even the request or session doesn't exist anymore, so it is not possible to use a request/session dependent bean. Also there is no way to know, if your are running a job in a separate thread, which thread is the originator request (it means aop:proxy is not helpful in this case).


I think your code looks like that you want to make a contract between ReportController, ReportBuilder, UselessTask and ReportPage. Is there a way to use just a simple class (POJO) to store data from UselessTask and read it in ReportController or ReportPage and do not use ReportBuilder anymore?

How can I create a memory leak in Java?

There are many good examples of memory leaks in Java, and I will mention two of them in this answer.

Example 1:

Here is a good example of a memory leak from the book Effective Java, Third Edition (item 7: Eliminate obsolete object references):

// Can you spot the "memory leak"?
public class Stack {
    private static final int DEFAULT_INITIAL_CAPACITY = 16;
    private Object[] elements;
    private int size = 0;

    public Stack() {
        elements = new Object[DEFAULT_INITIAL_CAPACITY];
    }

    public void push(Object e) {
        ensureCapacity();
        elements[size++] = e;
    }

    public Object pop() {
        if (size == 0) throw new EmptyStackException();
        return elements[--size];
    }

    /*** Ensure space for at least one more element, roughly* doubling the capacity each time the array needs to grow.*/
    private void ensureCapacity() {
        if (elements.length == size) elements = Arrays.copyOf(elements, 2 * size + 1);
    }
}

This is the paragraph of the book that describe why this implementation will cause a memory leak:

If a stack grows and then shrinks, the objects that were popped off the stack will not be garbage collected, even if the program using the stack has no more references to them. This is because the stack maintains obsolete references to these objects. An obsolete reference is simply a reference that will never be dereferenced again. In this case, any references outside of the “active portion” of the element array are obsolete. The active portion consists of the elements whose index is less than size

Here is the solution of the book to tackle this memory leak:

The fix for this sort of problem is simple: null out references once they become obsolete. In the case of our Stack class, the reference to an item becomes obsolete as soon as it’s popped off the stack. The corrected version of the pop method looks like this:

public Object pop() {
    if (size == 0) throw new EmptyStackException();
    Object result = elements[--size];
    elements[size] = null; // Eliminate obsolete reference
    return result;
}

But how can we prevent a memory leak from happening? This is a good caveat from the book:

Generally speaking, whenever a class manages its own memory, the programmer should be alert for memory leaks. Whenever an element is freed, any object references contained in the element should be nulled out.

Example 2:

The observer pattern also can cause a memory leak. You can read about this pattern in the following link: Observer pattern.

This is one implementation of Observer pattern:

class EventSource {
    public interface Observer {
        void update(String event);
    }

    private final List<Observer> observers = new ArrayList<>();

    private void notifyObservers(String event) {
        observers.forEach(observer -> observer.update(event)); //alternative lambda expression: observers.forEach(Observer::update);
    }

    public void addObserver(Observer observer) {
        observers.add(observer);
    }

    public void scanSystemIn() {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNextLine()) {
            String line = scanner.nextLine();
            notifyObservers(line);
        }
    }
}

In this implementation, EventSource, which is Observable in Observer design pattern, can hold link to Obeserver objects, but this link is never removed from the observers field in EventSource. So they will never be collected by the garbage collector. One solution to tackle this problem is providing another method to client for removing the aforementioned observers from observers field when they don't need those observers any more:

public void removeObserver(Observer observer) {
    observers.remove(observer);
}

Converting Varchar Value to Integer/Decimal Value in SQL Server

You are getting arithmetic overflow. this means you are trying to make a conversion impossible to be made. This error is thrown when you try to make a conversion and the destiny data type is not enough to convert the origin data. For example:

If you try to convert 100.52 to decimal(4,2) you will get this error. The number 100.52 requires 5 positions and 2 of them are decimal.

Try to change the decimal precision to something like 16,2 or higher. Try with few records first then use it to all your select.

Converting byte array to String (Java)

You can try this.

String s = new String(bytearray);

Where/How to getIntent().getExtras() in an Android Fragment?

What I tend to do, and I believe this is what Google intended for developers to do too, is to still get the extras from an Intent in an Activity and then pass any extra data to fragments by instantiating them with arguments.

There's actually an example on the Android dev blog that illustrates this concept, and you'll see this in several of the API demos too. Although this specific example is given for API 3.0+ fragments, the same flow applies when using FragmentActivity and Fragment from the support library.

You first retrieve the intent extras as usual in your activity and pass them on as arguments to the fragment:

public static class DetailsActivity extends FragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // (omitted some other stuff)

        if (savedInstanceState == null) {
            // During initial setup, plug in the details fragment.
            DetailsFragment details = new DetailsFragment();
            details.setArguments(getIntent().getExtras());
            getSupportFragmentManager().beginTransaction().add(
                    android.R.id.content, details).commit();
        }
    }
}

In stead of directly invoking the constructor, it's probably easier to use a static method that plugs the arguments into the fragment for you. Such a method is often called newInstance in the examples given by Google. There actually is a newInstance method in DetailsFragment, so I'm unsure why it isn't used in the snippet above...

Anyways, all extras provided as argument upon creating the fragment, will be available by calling getArguments(). Since this returns a Bundle, its usage is similar to that of the extras in an Activity.

public static class DetailsFragment extends Fragment {
    /**
     * Create a new instance of DetailsFragment, initialized to
     * show the text at 'index'.
     */
    public static DetailsFragment newInstance(int index) {
        DetailsFragment f = new DetailsFragment();

        // Supply index input as an argument.
        Bundle args = new Bundle();
        args.putInt("index", index);
        f.setArguments(args);

        return f;
    }

    public int getShownIndex() {
        return getArguments().getInt("index", 0);
    }

    // (other stuff omitted)

}

How to disable javax.swing.JButton in java?

The code is very long so I can't paste all the code.

There could be any number of reasons why your code doesn't work. Maybe you declared the button variables twice so you aren't actually changing enabling/disabling the button like you think you are. Maybe you are blocking the EDT.

You need to create a SSCCE to post on the forum.

So its up to you to isolate the problem. Start with a simple frame thas two buttons and see if your code works. Once you get that working, then try starting a Thread that simply sleeps for 10 seconds to see if it still works.

Learn how the basice work first before writing a 200 line program.

Learn how to do some basic debugging, we are not mind readers. We can't guess what silly mistake you are doing based on your verbal description of the problem.

How to configure Fiddler to listen to localhost?

By simply adding fiddler to the url

http://localhost.fiddler:8081/

Traffic is routed through fiddler and therefore being displayed on fiddler.

Get the data received in a Flask request

@app.route('/addData', methods=['POST'])
def add_data():
     data_in = mongo.db.Data
     id = request.values.get("id")
     name = request.values.get("name")
     newuser = {'id' : id, 'name' : name}
     if voter.find({'id' : id, 'name' : name}).count() > 0:
            return "Data Exists"
     else:
            data_in.insert(newuser)
            return "Data Added"

jQuery Event : Detect changes to the html/text of a div

You are looking for MutationObserver or Mutation Events. Neither are supported everywhere nor are looked upon too fondly by the developer world.

If you know (and can make sure that) the div's size will change, you may be able to use the crossbrowser resize event.

How to format a number 0..9 to display with 2 digits (it's NOT a date)

I know that is late to respond, but there are a basic way to do it, with no libraries. If your number is less than 100, then:

(number/100).toFixed(2).toString().slice(2);

What is the difference between re.search and re.match?

You can refer the below example to understand the working of re.match and re.search

a = "123abc"
t = re.match("[a-z]+",a)
t = re.search("[a-z]+",a)

re.match will return none, but re.search will return abc.

(change) vs (ngModelChange) in angular

1 - (change) is bound to the HTML onchange event. The documentation about HTML onchange says the following :

Execute a JavaScript when a user changes the selected option of a <select> element

Source : https://www.w3schools.com/jsref/event_onchange.asp

2 - As stated before, (ngModelChange) is bound to the model variable binded to your input.

So, my interpretation is :

  • (change) triggers when the user changes the input
  • (ngModelChange) triggers when the model changes, whether it's consecutive to a user action or not