Programs & Examples On #Spree

Spree is a complete open source e-commerce solution for Ruby on Rails, freely available for commercial use under the terms of the New BSD License.

What's the point of the X-Requested-With header?

Some frameworks are using this header to detect xhr requests e.g. grails spring security is using this header to identify xhr request and give either a json response or html response as response.

Most Ajax libraries (Prototype, JQuery, and Dojo as of v2.1) include an X-Requested-With header that indicates that the request was made by XMLHttpRequest instead of being triggered by clicking a regular hyperlink or form submit button.

Source: http://grails-plugins.github.io/grails-spring-security-core/guide/helperClasses.html

How does delete[] know it's an array?

delete or delete[] would probably both free the memory allocated (memory pointed), but the big difference is that delete on an array won't call the destructor of each element of the array.

Anyway, mixing new/new[] and delete/delete[] is probably UB.

Is there more to an interface than having the correct methods

Normally Interfaces define the interface you should use (as the name says it ;-) ). Sample


public void foo(List l) {
   ... do something
}

Now your function foo accepts ArrayLists, LinkedLists, ... not only one type.

The most important thing in Java is that you can implement multiple interfaces but you can only extend ONE class! Sample:


class Test extends Foo implements Comparable, Serializable, Formattable {
...
}
is possible but

class Test extends Foo, Bar, Buz {
...
}
is not!

Your code above could also be: IBox myBox = new Rectangle();. The important thing is now, that myBox ONLY contains the methods/fields from IBox and not the (possibly existing) other methods from Rectangle.

In AVD emulator how to see sdcard folder? and Install apk to AVD?

  1. switch to DDMS perspective
  2. select the emulator in devices list, whose sdcard you want to explore.
  3. open File Explorer tab on right hand side.
  4. expand tree structure. mnt/sdcard/

refer to image belowenter image description here


To install apk manually: copy your apk to to sdk/platform-tools folder and run following command in the same folder

adb install apklocation.apk

How to know if other threads have finished?

You could also use SwingWorker, which has built-in property change support. See addPropertyChangeListener() or the get() method for a state change listener example.

How to install a plugin in Jenkins manually

In my case, I needed to install a plugin to an offline build server that's running a Windows Server (version won't matter here). I already installed Jenkins on my laptop to test out changes in advance and it is running on localhost:8080 as a windows service.

So if you are willing to take the time to setup Jenkins on a machine with Internet connection and carry these changes to the offline server Jenkins (it works, confirmed by me!), these are steps you could follow:

  • Jenkins on my laptop: Open up Jenkins, http://localhost:8080
  • Navigator: Manage Jenkins | Download plugin without install option
  • Windows Explorer: Copy the downloaded plugin file that is located at "c:\program files (x86)\Jenkins\plugins" folder (i.e. role-strategy.jpi)
  • Paste it into a shared folder in the offline server
  • Stop the Jenkins Service (Offline Server Jenkins) through Component Services, Jenkins Service
  • Copy the plugin file (i.e. role-strategy.jpi) into "c:\program files (x86)\Jenkins\plugins" folder on the (Offline Jenkins) server
  • Restart Jenkins and voila! It should be installed.

Detect if a page has a vertical scrollbar?

I wrote an updated version of Kees C. Bakker's answer:

const hasVerticalScroll = (node) => {
  if (!node) {
    if (window.innerHeight) {
      return document.body.offsetHeight > window.innerHeight
    }
    return (document.documentElement.scrollHeight > document.documentElement.offsetHeight)
      || (document.body.scrollHeight > document.body.offsetHeight)
  }
  return node.scrollHeight > node.offsetHeight
}

if (hasVerticalScroll(document.querySelector('body'))) {
  this.props.handleDisableDownScrollerButton()
}

The function returns true or false depending whether the page has a vertical scrollbar or not.

For example:

const hasVScroll = hasVerticalScroll(document.querySelector('body'))

if (hasVScroll) {
  console.log('HAS SCROLL', hasVScroll)
}

How to use PHP with Visual Studio

Maybe we should help you with a big misunderstanding on your side first: PHP is (like ASP.NET or whatever you used to far) a server side language while javascript is client side.

This means that PHP will run on your webserver and create a HTML page dynamically which is then sent to the browser. Javascript in turn is embedded (either directly or as a referenced file) into this HTML page and runs in the browser.

Maybe you can now understand why your approach so far could never work out.

Various ways to remove local Git changes

Option 1: Discard tracked and untracked file changes

Discard changes made to both staged and unstaged files.

$ git reset --hard [HEAD]

Then discard (or remove) untracked files altogether.

$ git clean [-f]

Option 2: Stash

You can first stash your changes

$ git stash

And then either drop or pop it depending on what you want to do. See https://git-scm.com/docs/git-stash#_synopsis.

Option 3: Manually restore files to original state

First we switch to the target branch

$ git checkout <branch-name>

List all files that have changes

$ git status

Restore each file to its original state manually

$ git restore <file-path>

Django -- Template tag in {% if %} block

Sorry for comment in an old post but if you want to use an else if statement this will help you

{% if title == source %}
    Do This
{% elif title == value %}
    Do This
{% else %}
    Do This
{% endif %}

For more info see Django Documentation

Using the last-child selector

Another solution that might work for you is to reverse the relationship. So you would set the border for all list items. You would then use first-child to eliminate the border for the first item. The first-child is statically supported in all browsers (meaning it can't be added dynamically through other code, but first-child is a CSS2 selector, whereas last-child was added in the CSS3 specification)

Note: This only works the way you intended if you only have 2 items in the list like your example. Any 3rd item and on will have borders applied to them.

How do getters and setters work?

You may also want to read "Why getter and setter methods are evil":

Though getter/setter methods are commonplace in Java, they are not particularly object oriented (OO). In fact, they can damage your code's maintainability. Moreover, the presence of numerous getter and setter methods is a red flag that the program isn't necessarily well designed from an OO perspective.

This article explains why you shouldn't use getters and setters (and when you can use them) and suggests a design methodology that will help you break out of the getter/setter mentality.

How to Identify port number of SQL server

PowerShell solution that shows all of the instances on the host as well as their incoming traffic addresses. The second bit might be helpful if all you know is the DNS:

ForEach ($SQL_Proc in Get-Process | Select-Object -Property ProcessName, Id | Where-Object {$_.ProcessName -like "*SQL*"})
{
    Get-NetTCPConnection | `
     Where-Object {$_.OwningProcess -eq $SQL_Proc.id} | `
      Select-Object -Property `
                                @{Label ="Process_Name";e={$SQL_Proc.ProcessName}}, `
                                @{Label ="Local_Address";e={$_.LocalAddress + ":" + $_.LocalPort }},  `
                                @{Label ="Remote_Address";e={$_.RemoteAddress + ":" + $_.RemotePort}}, State | `
      Format-Table
} 

Resolve Javascript Promise outside function scope

I liked @JonJaques answer but I wanted to take it a step further.

If you bind then and catch then the Deferred object, then it fully implements the Promise API and you can treat it as promise and await it and such.

_x000D_
_x000D_
class DeferredPromise {_x000D_
  constructor() {_x000D_
    this._promise = new Promise((resolve, reject) => {_x000D_
      // assign the resolve and reject functions to `this`_x000D_
      // making them usable on the class instance_x000D_
      this.resolve = resolve;_x000D_
      this.reject = reject;_x000D_
    });_x000D_
    // bind `then` and `catch` to implement the same interface as Promise_x000D_
    this.then = this._promise.then.bind(this._promise);_x000D_
    this.catch = this._promise.catch.bind(this._promise);_x000D_
    this[Symbol.toStringTag] = 'Promise';_x000D_
  }_x000D_
}_x000D_
_x000D_
const deferred = new DeferredPromise();_x000D_
console.log('waiting 2 seconds...');_x000D_
setTimeout(() => {_x000D_
  deferred.resolve('whoa!');_x000D_
}, 2000);_x000D_
_x000D_
async function someAsyncFunction() {_x000D_
  const value = await deferred;_x000D_
  console.log(value);_x000D_
}_x000D_
_x000D_
someAsyncFunction();
_x000D_
_x000D_
_x000D_

What's the difference between JavaScript and JScript?

There are some code differences to be aware of.

A negative first parameter to subtr is not supported, e.g. in Javascript: "string".substr(-1) returns "g", whereas in JScript: "string".substr(-1) returns "string"

It's possible to do "string"[0] to get "s" in Javascript, but JScript doesn't support such a construct. (Actually, only modern browsers appear to support the "string"[0] construct.

TextView Marquee not working

You must add the these attributes which is compulsary to marquee

 android:ellipsize="marquee"     
 android:focusable="true"    
 android:focusableInTouchMode="true"     
 android:singleLine="true"     
 android:marqueeRepeatLimit="marquee_forever"     
 android:scrollHorizontally="true"

How to construct a REST API that takes an array of id's for the resources

As much as I prefer this approach:-

    api.com/users?id=id1,id2,id3,id4,id5

The correct way is

    api.com/users?ids[]=id1&ids[]=id2&ids[]=id3&ids[]=id4&ids[]=id5

or

    api.com/users?ids=id1&ids=id2&ids=id3&ids=id4&ids=id5

This is how rack does it. This is how php does it. This is how node does it as well...

How to force Chrome's script debugger to reload javascript?

If you're running a local server on Apache, you can get what look like caching problems. This happened to me when I had a Apache server running under Vagrant (in virtualbox).

Just add the following lines to your config file (/etc/httpd/conf/httpd.conf or equivalent):

#Disable image serving for network mounted drive
EnableSendfile off

Note that it's worth searching through the config file to see if EnableSendfile is set to on anywhere else.

How to pass json POST data to Web API method as an object?

EDIT : 31/10/2017

The same code/approach will work for Asp.Net Core 2.0 as well. The major difference is, In asp.net core, both web api controllers and Mvc controllers are merged together to single controller model. So your return type might be IActionResult or one of it's implementation (Ex :OkObjectResult)


Use

contentType:"application/json"

You need to use JSON.stringify method to convert it to JSON string when you send it,

And the model binder will bind the json data to your class object.

The below code will work fine (tested)

$(function () {
    var customer = {contact_name :"Scott",company_name:"HP"};
    $.ajax({
        type: "POST",
        data :JSON.stringify(customer),
        url: "api/Customer",
        contentType: "application/json"
    });
});

Result

enter image description here

contentType property tells the server that we are sending the data in JSON format. Since we sent a JSON data structure,model binding will happen properly.

If you inspect the ajax request's headers, you can see that the Content-Type value is set as application/json.

If you do not specify contentType explicitly, It will use the default content type which is application/x-www-form-urlencoded;


Edit on Nov 2015 to address other possible issues raised in comments

Posting a complex object

Let's say you have a complex view model class as your web api action method parameter like this

public class CreateUserViewModel
{
   public int Id {set;get;}
   public string Name {set;get;}  
   public List<TagViewModel> Tags {set;get;}
}
public class TagViewModel
{
  public int Id {set;get;}
  public string Code {set;get;}
}

and your web api end point is like

public class ProductController : Controller
{
    [HttpPost]
    public CreateUserViewModel Save([FromBody] CreateUserViewModel m)
    {
        // I am just returning the posted model as it is. 
        // You may do other stuff and return different response.
        // Ex : missileService.LaunchMissile(m);
        return m;
    }
}

At the time of this writing, ASP.NET MVC 6 is the latest stable version and in MVC6, Both Web api controllers and MVC controllers are inheriting from Microsoft.AspNet.Mvc.Controller base class.

To send data to the method from client side, the below code should work fine

//Build an object which matches the structure of our view model class
var model = {
    Name: "Shyju",
    Id: 123,
    Tags: [{ Id: 12, Code: "C" }, { Id: 33, Code: "Swift" }]
};

$.ajax({
    type: "POST",
    data: JSON.stringify(model),
    url: "../product/save",
    contentType: "application/json"
}).done(function(res) {       
    console.log('res', res);
    // Do something with the result :)
});

Model binding works for some properties, but not all ! Why ?

If you do not decorate the web api method parameter with [FromBody] attribute

[HttpPost]
public CreateUserViewModel Save(CreateUserViewModel m)
{
    return m;
}

And send the model(raw javascript object, not in JSON format) without specifying the contentType property value

$.ajax({
    type: "POST",
    data: model,
    url: "../product/save"
}).done(function (res) {
     console.log('res', res);
});

Model binding will work for the flat properties on the model, not the properties where the type is complex/another type. In our case, Id and Name properties will be properly bound to the parameter m, But the Tags property will be an empty list.

The same problem will occur if you are using the short version, $.post which will use the default Content-Type when sending the request.

$.post("../product/save", model, function (res) {
    //res contains the markup returned by the partial view
    console.log('res', res);
});

Excel Macro - Select all cells with data and format as table

Try this one for current selection:

Sub A_SelectAllMakeTable2()
    Dim tbl As ListObject
    Set tbl = ActiveSheet.ListObjects.Add(xlSrcRange, Selection, , xlYes)
    tbl.TableStyle = "TableStyleMedium15"
End Sub

or equivalent of your macro (for Ctrl+Shift+End range selection):

Sub A_SelectAllMakeTable()
    Dim tbl As ListObject
    Dim rng As Range

    Set rng = Range(Range("A1"), Range("A1").SpecialCells(xlLastCell))
    Set tbl = ActiveSheet.ListObjects.Add(xlSrcRange, rng, , xlYes)
    tbl.TableStyle = "TableStyleMedium15"
End Sub

MySQL foreign key constraints, cascade delete

I think (I'm not certain) that foreign key constraints won't do precisely what you want given your table design. Perhaps the best thing to do is to define a stored procedure that will delete a category the way you want, and then call that procedure whenever you want to delete a category.

CREATE PROCEDURE `DeleteCategory` (IN category_ID INT)
LANGUAGE SQL
NOT DETERMINISTIC
MODIFIES SQL DATA
SQL SECURITY DEFINER
BEGIN

DELETE FROM
    `products`
WHERE
    `id` IN (
        SELECT `products_id`
        FROM `categories_products`
        WHERE `categories_id` = category_ID
    )
;

DELETE FROM `categories`
WHERE `id` = category_ID;

END

You also need to add the following foreign key constraints to the linking table:

ALTER TABLE `categories_products` ADD
    CONSTRAINT `Constr_categoriesproducts_categories_fk`
    FOREIGN KEY `categories_fk` (`categories_id`) REFERENCES `categories` (`id`)
    ON DELETE CASCADE ON UPDATE CASCADE,
    CONSTRAINT `Constr_categoriesproducts_products_fk`
    FOREIGN KEY `products_fk` (`products_id`) REFERENCES `products` (`id`)
    ON DELETE CASCADE ON UPDATE CASCADE

The CONSTRAINT clause can, of course, also appear in the CREATE TABLE statement.

Having created these schema objects, you can delete a category and get the behaviour you want by issuing CALL DeleteCategory(category_ID) (where category_ID is the category to be deleted), and it will behave how you want. But don't issue a normal DELETE FROM query, unless you want more standard behaviour (i.e. delete from the linking table only, and leave the products table alone).

Invalid column count in CSV input on line 1 Error

When facing errors with input files of any type, encoding issues are common.

A simple solution might be to open a new file, copy pasting your CSV text in it, then saving it as a new file.

Jenkins/Hudson - accessing the current build number?

As per Jenkins Documentation,

BUILD_NUMBER

is used. This number is identify how many times jenkins run this build process $BUILD_NUMBER is general syntax for it.

How do I install Eclipse with C++ in Ubuntu 12.10 (Quantal Quetzal)?

I also tried http://www.eclipse.org/cdt/ in Ubuntu 12.04.2 LTS and works fine!

  1. First, I downloaded it from www.eclipse.org/downloads/, choosing Eclipse IDE for C/C++ Developers.
  2. I save the file somewhere, let´s say into my home directory. Open a console or terminal, and type:

    >>cd ~; tar xvzf eclipse*.tar.gz;

  3. Remember for having Eclipse running in Linux, it is required a JVM, so download a jdk file e.g jdk-7u17-linux-i586.rpm (I cann´t post the link due to my low reputation) ... anyway

  4. Install the .rpm file following http://www.wikihow.com/Install-Java-on-Linux

  5. Find the path to the Java installation, by typing:

    >>which java

  6. I got /usr/bin/java. To start up Eclipse, type:

    >>cd ~/eclipse; ./eclipse -vm /usr/bin/java

Also, once everything is installed, in the home directory, you can double-click the executable icon called eclipse, and then you´ll have it!. In case you like an icon, create a .desktop file in /usr/share/applications:

>>sudo gedit /usr/share/applications/eclipse.desktop

The .desktop file content is as follows:

[Desktop Entry]  
Name=Eclipse  
Type=Application  
Exec="This is the path of the eclipse executable on your machine"  
Terminal=false 
Icon="This is the path of the icon.xpm file on your machine"  
Comment=Integrated Development Environment  
NoDisplay=false  
Categories=Development;IDE  
Name[en]=eclipse.desktop  

Best luck!

How to print a string in C++

#include <iostream>
std::cout << someString << "\n";

or

printf("%s\n",someString.c_str());

Manage toolbar's navigation and back button from fragment in android

Add a toolbar to your xml

<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:background="?attr/colorPrimary"
    android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
    app:popupTheme="@style/ThemeOverlay.AppCompat.Light">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Fragment title"/>

</android.support.v7.widget.Toolbar>

Then inside your onCreateView method in the Fragment:

Toolbar toolbar = view.findViewById(R.id.toolbar);
toolbar.setNavigationIcon(R.drawable.ic_back_button);
toolbar.setNavigationOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
         getActivity().onBackPressed();
    }
});

Is there a way to cast float as a decimal without rounding and preserving its precision?

cast (field1 as decimal(53,8)
) field 1

The default is: decimal(18,0)

how to display toolbox on the left side of window of Visual Studio Express for windows phone 7 development?

I had this problem with Blend for Visual Studio 2015. The Toolbox would just not appear anymore. This turns out to be because Blend is not Visual Studio!

(You can edit your code in Blend and build and run it... It certainly seems like Visual Studio, but it isn't. I'm not sure what the purpose of Blend is...)

You can tell you are in Blend if the task bar icon has big "B" in it. To switch from Blend to Visual Studio, go to View-> Edit in Visual Studio.... It will open up another application that looks just like Blend, except the Solution Explorer is on the right instead of the left, and now you have a toolbox...

ComboBox- SelectionChanged event has old value, not new value

From SelectionChanged event of a combobox you can get the selected item text as follow:

        private void myComboBox_SelectionChanged (object sender, SelectionChangedEventArgs e)
        {
        ComboBoxItem comboBoxItem = (ComboBoxItem) e.AddedItems[0];
        string selectedItemText = comboBoxItem.Content.ToString();
        }

Socket.IO - how do I get a list of connected sockets/clients?

This is the simplest way in Socket.IO 1.0+, if you are not using namespaces or rooms.

io.nsps["/"].sockets.length

This looks at the default namespace and determines the length of the sockets array, without needing to use Object.keys()

ImportError: No module named PyQt4

You have to check which Python you are using. I had the same problem because the Python I was using was not the same one that brew was using. In your command line:

  1. which python
    output: /usr/bin/python
  2. which brew
    output: /usr/local/bin/brew     //so they are different
  3. cd /usr/local/lib/python2.7/site-packages
  4. ls   //you can see PyQt4 and sip are here
  5. Now you need to add usr/local/lib/python2.7/site-packages to your python path.
  6. open ~/.bash_profile   //you will open your bash_profile file in your editor
  7. Add 'export PYTHONPATH=/usr/local/lib/python2.7/site-packages:$PYTHONPATH' to your bash file and save it
  8. Close your terminal and restart it to reload the shell
  9. python
  10. import PyQt4    // it is ok now

What are the different types of keys in RDBMS?

Partial Key:

It is a set of attributes that can uniquely identify weak entities and that are related to same owner entity. It is sometime called as Discriminator.

Alternate Key:

All Candidate Keys excluding the Primary Key are known as Alternate Keys.

Artificial Key:

If no obvious key, either stand alone or compound is available, then the last resort is to simply create a key, by assigning a unique number to each record or occurrence. Then this is known as developing an artificial key.

Compound Key:

If no single data element uniquely identifies occurrences within a construct, then combining multiple elements to create a unique identifier for the construct is known as creating a compound key.

Natural Key:

When one of the data elements stored within a construct is utilized as the primary key, then it is called the natural key.

Is there a way to do repetitive tasks at intervals?

A broader answer to this question might consider the Lego brick approach often used in Occam, and offered to the Java community via JCSP. There is a very good presentation by Peter Welch on this idea.

This plug-and-play approach translates directly to Go, because Go uses the same Communicating Sequential Process fundamentals as does Occam.

So, when it comes to designing repetitive tasks, you can build your system as a dataflow network of simple components (as goroutines) that exchange events (i.e. messages or signals) via channels.

This approach is compositional: each group of small components can itself behave as a larger component, ad infinitum. This can be very powerful because complex concurrent systems are made from easy to understand bricks.

Footnote: in Welch's presentation, he uses the Occam syntax for channels, which is ! and ? and these directly correspond to ch<- and <-ch in Go.

How to make a HTTP request using Ruby on Rails?

Net::HTTP is built into Ruby, but let's face it, often it's easier not to use its cumbersome 1980s style and try a higher level alternative:

How do I do a bulk insert in mySQL using node.js

Bulk inserts are possible by using nested array, see the github page

Nested arrays are turned into grouped lists (for bulk inserts), e.g. [['a', 'b'], ['c', 'd']] turns into ('a', 'b'), ('c', 'd')

You just insert a nested array of elements.

An example is given in here

var mysql = require('mysql');
var conn = mysql.createConnection({
    ...
});

var sql = "INSERT INTO Test (name, email, n) VALUES ?";
var values = [
    ['demian', '[email protected]', 1],
    ['john', '[email protected]', 2],
    ['mark', '[email protected]', 3],
    ['pete', '[email protected]', 4]
];
conn.query(sql, [values], function(err) {
    if (err) throw err;
    conn.end();
});

Note: values is an array of arrays wrapped in an array

[ [ [...], [...], [...] ] ]

There is also a totally different node-msql package for bulk insertion

Correct way to integrate jQuery plugins in AngularJS

i have alreay 2 situations where directives and services/factories didnt play well.

the scenario is that i have (had) a directive that has dependency injection of a service, and from the directive i ask the service to make an ajax call (with $http).

in the end, in both cases the ng-Repeat did not file at all, even when i gave the array an initial value.

i even tried to make a directive with a controller and an isolated-scope

only when i moved everything to a controller and it worked like magic.

example about this here Initialising jQuery plugin (RoyalSlider) in Angular JS

How to write trycatch in R

tryCatch has a slightly complex syntax structure. However, once we understand the 4 parts which constitute a complete tryCatch call as shown below, it becomes easy to remember:

expr: [Required] R code(s) to be evaluated

error : [Optional] What should run if an error occured while evaluating the codes in expr

warning : [Optional] What should run if a warning occured while evaluating the codes in expr

finally : [Optional] What should run just before quitting the tryCatch call, irrespective of if expr ran successfully, with an error, or with a warning

tryCatch(
    expr = {
        # Your code...
        # goes here...
        # ...
    },
    error = function(e){ 
        # (Optional)
        # Do this if an error is caught...
    },
    warning = function(w){
        # (Optional)
        # Do this if an warning is caught...
    },
    finally = {
        # (Optional)
        # Do this at the end before quitting the tryCatch structure...
    }
)

Thus, a toy example, to calculate the log of a value might look like:

log_calculator <- function(x){
    tryCatch(
        expr = {
            message(log(x))
            message("Successfully executed the log(x) call.")
        },
        error = function(e){
            message('Caught an error!')
            print(e)
        },
        warning = function(w){
            message('Caught an warning!')
            print(w)
        },
        finally = {
            message('All done, quitting.')
        }
    )    
}

Now, running three cases:

A valid case

log_calculator(10)
# 2.30258509299405
# Successfully executed the log(x) call.
# All done, quitting.

A "warning" case

log_calculator(-10)
# Caught an warning!
# <simpleWarning in log(x): NaNs produced>
# All done, quitting.

An "error" case

log_calculator("log_me")
# Caught an error!
# <simpleError in log(x): non-numeric argument to mathematical function>
# All done, quitting.

I've written about some useful use-cases which I use regularly. Find more details here: https://rsangole.netlify.com/post/try-catch/

Hope this is helpful.

Javascript Array Alert

If you want to see the array as an array, you can say

alert(JSON.stringify(aCustomers));

instead of all those document.writes.

http://jsfiddle.net/5b2eb/

However, if you want to display them cleanly, one per line, in your popup, do this:

alert(aCustomers.join("\n"));

http://jsfiddle.net/5b2eb/1/

Set focus on textbox in WPF

In Code behind you can achieve it only by doing this.

 private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            txtIndex.Focusable = true;
            txtIndex.Focus();
        }

Note: It wont work before window is loaded

Center an element in Bootstrap 4 Navbar

make new style

.container {
    position: relative;
}
.center-nav {
    position: absolute;
    left: 0;
    right: 0;
    margin: 0 auto;
    width: auto;
    max-width: 200px;
    text-align: center;
}
.center-nav li{
  text-align: center;
  width:100%;
}

Replace website name UL with below

<ul class="nav navbar-nav center-nav">
        <li class="nav-item"><a class="nav-link" href="#">Website Name</a></li>
 </ul>

Hope this helps..

Run Batch File On Start-up

To start the batch file at the start of your system, you can also use a registry key.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

Here you can create a string. As name you can choose anything and the data is the full path to your file.

There is also the registry key

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce

to run something at only the next start of your system.

PHP memcached Fatal error: Class 'Memcache' not found

I went into wp-config/ and deleted the object-cache.php and advanced-cache.php and it worked fine for me.

SQL Greater than, Equal to AND Less Than

Supposing you use sql server:

WHERE StartTime BETWEEN DATEADD(HOUR, -1, GetDate())
                    AND DATEADD(HOUR, 1, GetDate())

How to check if a date is in a given range?

Convert both dates to timestamps then do

pseudocode:

if date_from_user > start_date && date_from_user < end_date
    return true

How can I tail a log file in Python?

The only portable way to tail -f a file appears to be, in fact, to read from it and retry (after a sleep) if the read returns 0. The tail utilities on various platforms use platform-specific tricks (e.g. kqueue on BSD) to efficiently tail a file forever without needing sleep.

Therefore, implementing a good tail -f purely in Python is probably not a good idea, since you would have to use the least-common-denominator implementation (without resorting to platform-specific hacks). Using a simple subprocess to open tail -f and iterating through the lines in a separate thread, you can easily implement a non-blocking tail operation in Python.

Example implementation:

import threading, Queue, subprocess
tailq = Queue.Queue(maxsize=10) # buffer at most 100 lines

def tail_forever(fn):
    p = subprocess.Popen(["tail", "-f", fn], stdout=subprocess.PIPE)
    while 1:
        line = p.stdout.readline()
        tailq.put(line)
        if not line:
            break

threading.Thread(target=tail_forever, args=(fn,)).start()

print tailq.get() # blocks
print tailq.get_nowait() # throws Queue.Empty if there are no lines to read

Delete last commit in bitbucket

Once changes has been committed it will not be able to delete. because commit's basic nature is not to delete.

Thing you can do (easy and safe method),

Interactive Rebase:

1) git rebase -i HEAD~2 #will show your recent 2 commits

2) Your commit will list like , Recent will appear at the bottom of the page LILO(last in Last Out)

enter image description here

Delete the last commit row entirely

3) save it by ctrl+X or ESC:wq

now your branch will updated without your last commit..

How to set a default Value of a UIPickerView

I too had this problem. But apparently there is an issue of the order of method calls. You must call:

[self.picker selectRow:2 inComponent:0 animated:YES];

after calling

[self.view addSubview:self.picker];

Getting session value in javascript

protected void Page_Load(object sender, EventArgs e)
    {
        Session["MyTest"] = "abcd";

        String csname = "OnSubmitScript";
        Type cstype = this.GetType();

        // Get a ClientScriptManager reference from the Page class.
        ClientScriptManager cs = Page.ClientScript;

        // Check to see if the OnSubmit statement is already registered.
        if (!cs.IsOnSubmitStatementRegistered(cstype, csname))
        {
            string cstext = " document.getElementById(\"TextBox1\").value = getMyvalSession()  ; ";
            cs.RegisterOnSubmitStatement(cstype, csname, cstext);
        }

        if (TextBox1.Text.Equals("")) { }
        else {
              Session["MyTest"] = TextBox1.Text;
        }

    }


<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">

    <script language=javascript type="text/javascript">
        function getMyvalSession() {

             var txt = "efgh";
             var ff = '<%=Session["MyTest"] %>' + txt;
             return ff ;
        }
    </script>

</head>
<body>

    <form id="form1" runat="server">
    <div>
        <asp:TextBox ID="TextBox1" runat="server"  AutoPostBack=true ></asp:TextBox>
     <input type="submit"  value="Submit" />
    </div>
    </form>
</body>
</html>

How to pass data from child component to its parent in ReactJS?

You can even avoid the function at the parent updating the state directly

In Parent Component:

render(){
 return(<Child sendData={ v => this.setState({item: v}) } />);
}

In the Child Component:

demoMethod(){
   this.props.sendData(value);
}

How can I replace newline or \r\n with <br/>?

You may have real characters "\" in the string (the single quote strings, as said @Robik).

If you are quite sure the '\r' or '\n' strings should be replaced as well, I'm not talking of special characters here but a sequence of two chars '\' and 'r', then escape the '\' in the replace string and it will work:

str_replace(array("\r\n","\r","\n","\\r","\\n","\\r\\n"),"<br/>",$description);

Changing element style attribute dynamically using JavaScript

I change css style in Javascript function.

But Uncaught TypeError: bild is null .

If I run it in a normal html file it work.

CODE:

  var text = document.getElementById("text");
var bild = document.getElementById("bild");
var container = document.getElementById("container");

bild.style["background-image"] = "url('stock-bild-portrait-of-confident-senior-business-woman-standing-in-office-with-her-arms-crossed-mature-female-1156978234.jpg')";
//bild.style.background-image = "url('stock-bild-portrait-of-confident-senior-business-woman-standing-in-office-with-her-arms-crossed-mature-female-1156978234.jpg')";

 //  bild.style["background-image"] =  "url('" +  defaultpic + "')";
 alert (bild.style["background-image"]) ;
 bild.style["background-size"] = "300px";
 bild.style["background-repeat"] = "no-repeat";
 bild.style["background-position"] = "center";
 bild.style["border-radius"] = "50%";
 bild.style["background-clip"] = "border-box";
 bild.style["transition"] = "background-size 0.2s";
 bild.style["transition-timing-function"] = "cubic-bezier(.07,1.41,.82,1.41)";
 bild.style["display"] = "block";
 bild.style["width"] = "100px";
 bild.style["height"] = "100px";

 bild.style["text-decoration"] = "none";
 bild.style["cursor"] = "pointer";
 bild.style["overflow"] = "hidden";
 bild.style["text-indent"] = "100%";
 bild.style["white-space"] = "nowrap";

 container.style["position"] = "relative";
 container.style["font-family"] = "Arial";

 text.style["position"] = "center";
 text.style["bottom"] = "5px";
 text.style["left"] = "1px";
 text.style["color"] = "white";

How can one create an overlay in css?

         div{
         background-image:url('');
         background-size:cover;
         background-position:top center;
         position:relative;
         }

         div:before{
         content:'';
         position:absolute;
         left:0;
         top:0;
         height:100%;
         width:100%;
         background-color:rgba(0,0,0,0.7);
         }

Composer: Command Not Found

This problem arises when you have composer installed locally. To make it globally executable,run the below command in terminal

sudo mv composer.phar /usr/local/bin/composer

For CentOS 7 the command is

sudo mv composer.phar /usr/bin/composer

How can I dynamically set the position of view in Android?

Set the left position of this view relative to its parent:

view.setLeft(int leftPosition);

Set the right position of this view relative to its parent:

view.setRight(int rightPosition);

Set the top position of this view relative to its parent:

view.setTop(int topPosition);

Set the bottom position of this view relative to its parent:

view.setBottom(int bottomPositon);

The above methods are used to set the position the view related to its parent.

How do I tell what type of value is in a Perl variable?

$x is always a scalar. The hint is the sigil $: any variable (or dereferencing of some other type) starting with $ is a scalar. (See perldoc perldata for more about data types.)

A reference is just a particular type of scalar. The built-in function ref will tell you what kind of reference it is. On the other hand, if you have a blessed reference, ref will only tell you the package name the reference was blessed into, not the actual core type of the data (blessed references can be hashrefs, arrayrefs or other things). You can use Scalar::Util 's reftype will tell you what type of reference it is:

use Scalar::Util qw(reftype);

my $x = bless {}, 'My::Foo';
my $y = { };

print "type of x: " . ref($x) . "\n";
print "type of y: " . ref($y) . "\n";
print "base type of x: " . reftype($x) . "\n";
print "base type of y: " . reftype($y) . "\n";

...produces the output:

type of x: My::Foo
type of y: HASH
base type of x: HASH
base type of y: HASH

For more information about the other types of references (e.g. coderef, arrayref etc), see this question: How can I get Perl's ref() function to return REF, IO, and LVALUE? and perldoc perlref.

Note: You should not use ref to implement code branches with a blessed object (e.g. $ref($a) eq "My::Foo" ? say "is a Foo object" : say "foo not defined";) -- if you need to make any decisions based on the type of a variable, use isa (i.e if ($a->isa("My::Foo") { ... or if ($a->can("foo") { ...). Also see polymorphism.

MySQL DROP all tables, ignoring foreign keys

I came up with this modification on Dion Truter's answer to make it easier with many tables:

SET GROUP_CONCAT_MAX_LEN = 10000000;
SELECT CONCAT('SET FOREIGN_KEY_CHECKS=0;\n', 
              GROUP_CONCAT(CONCAT('DROP TABLE IF EXISTS `', table_name, '`')
                           SEPARATOR ';\n'),
              ';\nSET FOREIGN_KEY_CHECKS=1;')
FROM information_schema.tables
WHERE table_schema = 'SchemaName';

This returns the entire thing in one field, so you can copy once and delete all the tables (use Copy Field Content (unquoted) in Workbench). If you have a LOT of tables, you may hit some limits on GROUP_CONCAT(). If so, increase the max len variable (and max_allowed_packet, if necessary).

SQL Client for Mac OS X that works with MS SQL Server

Let's work together on a canonical answer.

Native Apps

Java-Based

Electron-Based

(TODO: Add others mentioned below)

How to Edit a row in the datatable

Try this I am also not 100 % sure

        for( int i = 0 ;i< dt.Rows.Count; i++)
        {
           If(dt.Rows[i].Product_id == 2)
           {
              dt.Rows[i].Columns["Product_name"].ColumnName = "cde";
           }
        }

Printing one character at a time from a string, using the while loop

Other answers have already given you the code you need to iterate though a string using a while loop (or a for loop) but I thought it might be useful to explain the difference between the two types of loops.

while loops repeat some code until a certain condition is met. For example:

import random

sum = 0
while sum < 100:
    sum += random.randint(0,100) #add a random number between 0 and 100 to the sum
    print sum

This code will keep adding random numbers between 0 and 100 until the total is greater or equal to 100. The important point is that this loop could run exactly once (if the first random number is 100) or it could run forever (if it keeps selecting 0 as the random number). We can't predict how many times the loop will run until after it completes.

for loops are basically just while loops but we use them when we want a loop to run a preset number of times. Java for loops usually use some sort of a counter variable (below I use i), and generally makes the similarity between while and for loops much more explicit.

for (int i=0; i < 10; i++) { //starting from 0, until i is 10, adding 1 each iteration
    System.out.println(i);
}

This loop will run exactly 10 times. This is just a nicer way to write this:

int i = 0;
while (i < 10) { //until i is 10
   System.out.println(i);
   i++; //add one to i 
}

The most common usage for a for loop is to iterate though a list (or a string), which Python makes very easy:

for item in myList:
    print item

or

for character in myString:
    print character

However, you didn't want to use a for loop. In that case, you'll need to look at each character using its index. Like this:

print myString[0] #print the first character
print myString[len(myString) - 1] # print the last character.

Knowing that you can make a for loop using only a while loop and a counter and knowing that you can access individual characters by index, it should now be easy to access each character one at a time using a while loop.

HOWEVER in general you'd use a for loop in this situation because it's easier to read.

How to hide underbar in EditText

You can also define a STYLE for your editText so you can regroup all properties in common. It is very powerful if you have to multiple edit text that need to has the behaviour

Put the code in res/values/styles.xml

<style name="MyEditTextStyle" parent="@android:style/TextAppearance.Widget.EditText">
    <item name="android:background">@color/transparence</item> //NO UNDERBAR
    <item name="android:maxLines">1</item>
    <item name="android:height">28dp</item> //COMMON HEIGHT
</style>

After that you just need to call it in your editText

<EditText
    android:id="@+id/edit1"
    style="@style/MyEditTextStyle"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" />

<EditText
    android:id="@+id/edit2"
    style="@style/MyEditTextStyle"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" />

jQuery Validation using the class instead of the name value

I know this is an old question. But I too needed the same one recently, and I got this question from stackoverflow + another answer from this blog. The answer which was in the blog was more straight forward as it focuses specially for this kind of a validation. Here is how to do it.

$.validator.addClassRules("price", {
     required: true,
     minlength: 2
});

This method does not require you to have validate method above this call.

Hope this will help someone in the future too. Source here.

Decorators with parameters?

enter image description here

  • Here we ran display info twice with two different names and two different ages.
  • Now every time we ran display info, our decorators also added the functionality of printing out a line before and a line after that wrapped function.
def decorator_function(original_function):
    def wrapper_function(*args, **kwargs):
        print('Executed Before', original_function.__name__)
        result = original_function(*args, **kwargs)
        print('Executed After', original_function.__name__, '\n')
        return result
    return wrapper_function


@decorator_function
def display_info(name, age):
    print('display_info ran with arguments ({}, {})'.format(name, age))


display_info('Mr Bean', 66)
display_info('MC Jordan', 57)

output:

Executed Before display_info
display_info ran with arguments (Mr Bean, 66)
Executed After display_info 

Executed Before display_info
display_info ran with arguments (MC Jordan, 57)
Executed After display_info 
  • So now let's go ahead and get our decorator function to accept arguments.

  • For example let's say that I wanted a customizable prefix to all of these print statements within the wrapper.

  • Now this would be a good candidate for an argument to the decorator.

  • The argument that we pass in will be that prefix. Now in order to do, this we're just going to add another outer layer to our decorator, so I'm going to call this a function a prefix decorator.

def prefix_decorator(prefix):
    def decorator_function(original_function):
        def wrapper_function(*args, **kwargs):
            print(prefix, 'Executed Before', original_function.__name__)
            result = original_function(*args, **kwargs)
            print(prefix, 'Executed After', original_function.__name__, '\n')
            return result
        return wrapper_function
    return decorator_function


@prefix_decorator('LOG:')
def display_info(name, age):
    print('display_info ran with arguments ({}, {})'.format(name, age))


display_info('Mr Bean', 66)
display_info('MC Jordan', 57)

output:

LOG: Executed Before display_info
display_info ran with arguments (Mr Bean, 66)
LOG: Executed After display_info 

LOG: Executed Before display_info
display_info ran with arguments (MC Jordan, 57)
LOG: Executed After display_info 
  • Now we have that LOG: prefix before our print statements in our wrapper function and you can change this any time that you want.

Getting Class type from String

Not sure what you are asking, but... Class.forname, maybe?

Python, remove all non-alphabet chars from string

Try:

s = ''.join(filter(str.isalnum, s))

This will take every char from the string, keep only alphanumeric ones and build a string back from them.

Is there a way to create key-value pairs in Bash script?

For persistent key/value storage, you can use kv-bash, a pure bash implementation of key/value database available at https://github.com/damphat/kv-bash

Usage

git clone https://github.com/damphat/kv-bash
source kv-bash/kv-bash

Try create some permanent variables

kvset myName  xyz
kvset myEmail [email protected]

#read the varible
kvget myEmail

#you can also use in another script with $(kvget keyname)
echo $(kvget myEmail)

Kotlin unresolved reference in IntelliJ

Invalidating caches and updating the Kotlin plugin in Android Studio did the trick for me.

Remove or uninstall library previously added : cocoapods

  1. Remove pod name(which to remove) from Podfile and then
  2. Open Terminal, set project folder path
  3. Run pod install --no-integrate

How to generate Entity Relationship (ER) Diagram of a database using Microsoft SQL Server Management Studio?

As of Oct 2019, SQL Server Management Studio, they did not upgraded the SSMS to add create ER Diagram feature.

I would suggest try using DBWeaver from here :

https://dbeaver.io/download/

I am using Mac and Windows both and I was able to download the community edition and logged into my SQL server database and was able to create the ER diagram using the DB Weaver.

ER Diagram using the Community Version Db Viewer

What is a "bundle" in an Android application

Bundle is not only to transfer data between two different components but more importantly it is used to restore the values stored before activity is destroyed into new activity.

such as the text in an EditText widget or the scroll position of a ListView.

How to get Exception Error Code in C#

Another method would be to get the error code from the exception class directly. For example:

catch (Exception ex)
{
    if (ex.InnerException is ServiceResponseException)
       {
        ServiceResponseException srex = ex.InnerException as ServiceResponseException;
        string ErrorCode = srex.ErrorCode.ToString();
       }
}

IOException: The process cannot access the file 'file path' because it is being used by another process

I got this error because I was doing File.Move to a file path without a file name, need to specify the full path in the destination.

AngularJS Error: $injector:unpr Unknown Provider

In my case, I added a new service (file) to my app. That new service is injected in an existing controller. I did not miss new service dependency injection into that existing controller and did not declare my app module no more than one place. The same exception is thrown when I re-run my web app and my browser cache is not reset with a new service file codes. I simply refreshed my browser to get that new service file for browser cache, and the problem was gone.

Trigger a button click with JavaScript on the Enter key in a text box

Short working pure JS

txtSearch.onkeydown= e => (e.key=="Enter") ? btnSearch.click() : 1

_x000D_
_x000D_
txtSearch.onkeydown= e => (e.key=="Enter") ? btnSearch.click() : 1

function doSomething() {
  console.log('');
}
_x000D_
<input type="text" id="txtSearch" />
<input type="button" id="btnSearch" value="Search" onclick="doSomething();" />
_x000D_
_x000D_
_x000D_

If table exists drop table then create it, if it does not exist just create it

Just put DROP TABLE IF EXISTS `tablename`; before your CREATE TABLE statement.

That statement drops the table if it exists but will not throw an error if it does not.

Linux cmd to search for a class file among jars irrespective of jar path

I have used this small snippet. Might be slower but works every time.

for i in 'find . -type f -name "*.jar"'; do
    jar tvf $i | grep "com.foo.bar.MyClass.clss";
    if [ $? -eq 0 ]; then echo $i; fi;
done

Detect rotation of Android phone in the browser with JavaScript

Here is the solution:

var isMobile = {
    Android: function() {
        return /Android/i.test(navigator.userAgent);
    },
    iOS: function() {
        return /iPhone|iPad|iPod/i.test(navigator.userAgent);
    }
};
if(isMobile.Android())
    {
        var previousWidth=$(window).width();
        $(window).on({
        resize: function(e) {
        var YourFunction=(function(){

            var screenWidth=$(window).width();
            if(previousWidth!=screenWidth)
            {
                previousWidth=screenWidth;
                alert("oreientation changed");
            }

        })();

        }
    });

    }
    else//mainly for ios
    {
        $(window).on({
            orientationchange: function(e) {
               alert("orientation changed");
            }   
        });
    }

Include CSS,javascript file in Yii Framework

In the view, add the following:

<?php  
  $cs = Yii::app()->getClientScript();
  $cs->registerScriptFile('/js/yourscript.js', CClientScript::POS_END);
  $cs->registerCssFile('/css/yourcss.css');
?>

Please notice the second parameter when you register the js file, it's the position of your script, when you set it CClientScript::POS_END, you let the HTML renders before the javascript is loaded.

MySQL Select last 7 days

The WHERE clause is misplaced, it has to follow the table references and JOIN operations.

Something like this:

 FROM tartikel p1 
 JOIN tartikelpict p2 
   ON p1.kArtikel = p2.kArtikel 
  AND p2.nNr = 1
WHERE p1.dErstellt >= DATE(NOW()) - INTERVAL 7 DAY
ORDER BY p1.kArtikel DESC

EDIT (three plus years later)

The above essentially answers the question "I tried to add a WHERE clause to my query and now the query is returning an error, how do I fix it?"

As to a question about writing a condition that checks a date range of "last 7 days"...

That really depends on interpreting the specification, what the datatype of the column in the table is (DATE or DATETIME) and what data is available... what should be returned.

To summarize: the general approach is to identify a "start" for the date/datetime range, and "end" of that range, and reference those in a query. Let's consider something easier... all rows for "yesterday".

If our column is DATE type. Before we incorporate an expression into a query, we can test it in a simple SELECT

 SELECT DATE(NOW()) + INTERVAL -1 DAY 

and verify the result returned is what we expect. Then we can use that same expression in a WHERE clause, comparing it to a DATE column like this:

 WHERE datecol = DATE(NOW()) + INTERVAL -1 DAY

For a DATETIME or TIMESTAMP column, we can use >= and < inequality comparisons to specify a range

 WHERE datetimecol >= DATE(NOW()) + INTERVAL -1 DAY
   AND datetimecol <  DATE(NOW()) + INTERVAL  0 DAY

For "last 7 days" we need to know if that mean from this point right now, back 7 days ... e.g. the last 7*24 hours , including the time component in the comparison, ...

 WHERE datetimecol >= NOW() + INTERVAL -7 DAY
   AND datetimecol <  NOW() + INTERVAL  0 DAY

the last seven complete days, not including today

 WHERE datetimecol >= DATE(NOW()) + INTERVAL -7 DAY
   AND datetimecol <  DATE(NOW()) + INTERVAL  0 DAY

or past six complete days plus so far today ...

 WHERE datetimecol >= DATE(NOW()) + INTERVAL -6 DAY
   AND datetimecol <  NOW()       + INTERVAL  0 DAY

I recommend testing the expressions on the right side in a SELECT statement, we can use a user-defined variable in place of NOW() for testing, not being tied to what NOW() returns so we can test borders, across week/month/year boundaries, and so on.

SET @clock = '2017-11-17 11:47:47' ;

SELECT DATE(@clock)
     , DATE(@clock) + INTERVAL -7 DAY 
     , @clock + INTERVAL -6 DAY 

Once we have expressions that return values that work for "start" and "end" for our particular use case, what we mean by "last 7 days", we can use those expressions in range comparisons in the WHERE clause.

(Some developers prefer to use the DATE_ADD and DATE_SUB functions in place of the + INTERVAL val DAY/HOUR/MINUTE/MONTH/YEAR syntax.

And MySQL provides some convenient functions for working with DATE, DATETIME and TIMESTAMP datatypes... DATE, LAST_DAY,

Some developers prefer to calculate the start and end in other code, and supply string literals in the SQL query, such that the query submitted to the database is

  WHERE datetimecol >= '2017-11-10 00:00'
    AND datetimecol <  '2017-11-17 00:00'

And that approach works too. (My preference would be to explicitly cast those string literals into DATETIME, either with CAST, CONVERT or just the + INTERVAL trick...

  WHERE datetimecol >= '2017-11-10 00:00' + INTERVAL 0 SECOND
    AND datetimecol <  '2017-11-17 00:00' + INTERVAL 0 SECOND

The above all assumes we are storing "dates" in appropriate DATE, DATETIME and/or TIMESTAMP datatypes, and not storing them as strings in variety of formats e.g. 'dd/mm/yyyy', m/d/yyyy, julian dates, or in sporadically non-canonical formats, or as a number of seconds since the beginning of the epoch, this answer would need to be much longer.

Gmail: 530 5.5.1 Authentication Required. Learn more at

You need to go here https://security.google.com/settings/security/apppasswords

then select Gmail and then select device. then click on Generate. Simply Copy & Paste password which is generated by Google.

How to create an email form that can send email using html

As many answers in this thread already suggest it is not possible to send a mail from a static HTML page without using PHP or JS. I just wanted to add that there a some great solutions which will take your HTTP Post request generated by your form and create a mail from it. Those solutions are especially useful in case you do not want to add JS or PHP to your website.

Those servers basically can be configured with a mail-server which is responsible for then sending the email. The receiver, subject, body etc. is received by the server from your HTTP(S) post and then stuffed into the mail you want to send. So technically speaking it is still not possible to send mails from your HTML form but the outcome is the same.

Some of these solutions can be bought as SaaS solution or you can host them by yourself. I'll just name a few but I'm sure there are plenty in case anyone is interested in the technology or the service itself.

Regular Expression Validation For Indian Phone Number and Mobile number

All Landline Numbers and Mobile Number

^[\d]{2,4}[- ]?[\d]{3}[- ]?[\d]{3,5}|([0])?(\+\d{1,2}[- ]?)?[789]{1}\d{9}$

How to fix Invalid AES key length?

Things to know in general:

  1. Key != Password
    • SecretKeySpec expects a key, not a password. See below
  2. It might be due to a policy restriction that prevents using 32 byte keys. See other answer on that

In your case

The problem is number 1: you are passing the password instead of the key.

AES only supports key sizes of 16, 24 or 32 bytes. You either need to provide exactly that amount or you derive the key from what you type in.

There are different ways to derive the key from a passphrase. Java provides a PBKDF2 implementation for such a purpose.

I used erickson's answer to paint a complete picture (only encryption, since the decryption is similar, but includes splitting the ciphertext):

SecureRandom random = new SecureRandom();
byte[] salt = new byte[16];
random.nextBytes(salt);

KeySpec spec = new PBEKeySpec("password".toCharArray(), salt, 65536, 256); // AES-256
SecretKeyFactory f = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
byte[] key = f.generateSecret(spec).getEncoded();
SecretKeySpec keySpec = new SecretKeySpec(key, "AES");

byte[] ivBytes = new byte[16];
random.nextBytes(ivBytes);
IvParameterSpec iv = new IvParameterSpec(ivBytes);

Cipher c = Cipher.getInstance("AES/CBC/PKCS5Padding");
c.init(Cipher.ENCRYPT_MODE, keySpec, iv);
byte[] encValue = c.doFinal(valueToEnc.getBytes());

byte[] finalCiphertext = new byte[encValue.length+2*16];
System.arraycopy(ivBytes, 0, finalCiphertext, 0, 16);
System.arraycopy(salt, 0, finalCiphertext, 16, 16);
System.arraycopy(encValue, 0, finalCiphertext, 32, encValue.length);

return finalCiphertext;

Other things to keep in mind:

  • Always use a fully qualified Cipher name. AES is not appropriate in such a case, because different JVMs/JCE providers may use different defaults for mode of operation and padding. Use AES/CBC/PKCS5Padding. Don't use ECB mode, because it is not semantically secure.
  • If you don't use ECB mode then you need to send the IV along with the ciphertext. This is usually done by prefixing the IV to the ciphertext byte array. The IV is automatically created for you and you can get it through cipherInstance.getIV().
  • Whenever you send something, you need to be sure that it wasn't altered along the way. It is hard to implement a encryption with MAC correctly. I recommend you to use an authenticated mode like CCM or GCM.

How can I print using JQuery

Try like

$('.printMe').click(function(){
     window.print();
});

or if you want to print selected area try like

$('.printMe').click(function(){
     $("#outprint").print();
});

How to append data to div using JavaScript?

Beware of innerHTML, you sort of lose something when you use it:

theDiv.innerHTML += 'content';

Is equivalent to:

theDiv.innerHTML = theDiv.innerHTML + 'content';

Which will destroy all nodes inside your div and recreate new ones. All references and listeners to elements inside it will be lost.

If you need to keep them (when you have attached a click handler, for example), you have to append the new contents with the DOM functions(appendChild,insertAfter,insertBefore):

var newNode = document.createElement('div');
newNode.innerHTML = data;
theDiv.appendChild(newNode);

Add an object to an Array of a custom class

The array declaration should be:

Car[] garage = new Car[100];

You can also just assign directly:

garage[1] = new Car("Blue");

Why can't non-default arguments follow default arguments?

Let me clear two points here :

  • firstly non-default argument should not follow default argument , it means you can't define (a=b,c) in function the order of defining parameter in function are :
    • positional parameter or non-default parameter i.e (a,b,c)
    • keyword parameter or default parameter i.e (a="b",r="j")
    • keyword-only parameter i.e (*args)
    • var-keyword parameter i.e (**kwargs)

def example(a, b, c=None, r="w" , d=[], *ae, **ab):

(a,b) are positional parameter

(c=none) is optional parameter

(r="w") is keyword parameter

(d=[]) is list parameter

(*ae) is keyword-only

(**ab) is var-keyword parameter

  • now secondary thing is if i try something like this : def example(a, b, c=a,d=b):

argument is not defined when default values are saved,Python computes and saves default values when you define the function

c and d are not defined, does not exist, when this happens (it exists only when the function is executed)

"a,a=b" its not allowed in parameter.

How do I remove the passphrase for the SSH key without having to create a new key?

$ ssh-keygen -p worked for me

Opened git bash. Pasted : $ ssh-keygen -p

Hit enter for default location.

Enter old passphrase

Enter new passphrase - BLANK

Confirm new passphrase - BLANK

BOOM the pain of entering passphrase for git push was gone.

Thanks!

Decompile an APK, modify it and then recompile it

I know this question is answered still, I would like to pass an information how to get source code from apk with out dexjar.

There is an online decompiler for android apks

  1. Upload apk from local machine
  2. Wait some moments
  3. Download source code in zip format

I don't know how reliable is this.

@darkheir Answer is the manual way to do decompile apk. It helps us to understand different phases in Apk creation.

Once you have source code , follow the step mentioned in the accepted answer

Report so many ads on this links Another online Apk De-compiler @Andrew Rukin : http://www.javadecompilers.com/apk

Still worth. Hats Off to creators.

MySQL - How to parse a string value to DATETIME format inside an INSERT statement?

Use MySQL's STR_TO_DATE() function to parse the string that you're attempting to insert:

INSERT INTO tblInquiry (fldInquiryReceivedDateTime) VALUES
  (STR_TO_DATE('5/15/2012 8:06:26 AM', '%c/%e/%Y %r'))

What is the difference between using constructor vs getInitialState in React / React Native?

The big difference is start from where they are coming from, so constructor is the constructor of your class in JavaScript, on the other side, getInitialState is part of the lifecycle of React . The constructor method is a special method for creating and initializing an object created with a class.

How to terminate the script in JavaScript?

Not applicable in most circumstances, but I had lots of async scripts running in the browser and as a hack I do

window.reload();

to stop everything.

Replace Div Content onclick

Working from your jsFiddle example:

The jsFiddle was fine, but you were missing semi-colons at the end of the event.preventDefault() statements.

This works: Revised jsFiddle

jQuery(document).ready(function() {
    jQuery(".rec1").click(function(event) {
        event.preventDefault();
        jQuery('#rec-box').html(jQuery(this).next().html()); 
    });
    jQuery(".rec2").click(function(event) {
        event.preventDefault();
        jQuery('#rec-box2').html(jQuery(this).next().html()); 
    });
});

How to set the custom border color of UIView programmatically?

Swift 3.0

       groundTrump.layer.borderColor = UIColor.red.cgColor

Set value for particular cell in pandas DataFrame using index

I would suggest:

df.loc[index_position, "column_name"] = some_value

How to hide the title bar for an Activity in XML with existing custom theme

You just need to change AppTheme style in Style.xml if you replace the definition from DarkActionBar

<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">

to NoActionBar

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">

the AppTheme defined in AndroidManifast.xml

Why can't I make a vector of references?

By their very nature, references can only be set at the time they are created; i.e., the following two lines have very different effects:

int & A = B;   // makes A an alias for B
A = C;         // assigns value of C to B.

Futher, this is illegal:

int & D;       // must be set to a int variable.

However, when you create a vector, there is no way to assign values to it's items at creation. You are essentially just making a whole bunch of the last example.

Change SQLite database mode to read-write

In Linux command shell, I did:

chmod 777 <db_folder>

Where contains the database file.

It works. Now I can access my database and make insert queries.

How to open a specific port such as 9090 in Google Compute Engine

console.cloud.google.com >> select project >> Networking > VPC network >> firewalls >> create firewall.

To apply the rule to VM instances, select Targets, "Specified target tags", and enter into "Target tags" the name of the tag. This tag will be used to apply the new firewall rule onto whichever instance you'd like.

in "Protocols and Ports" enter tcp:9090

Click Save.

Datanode process not running in Hadoop

Follow these steps and your datanode will start again.

  1. Stop dfs.
  2. Open hdfs-site.xml
  3. Remove the data.dir and name.dir properties from hdfs-site.xml and -format namenode again.
  4. Then remove the hadoopdata directory and add the data.dir and name.dir in hdfs-site.xml and again format namenode.
  5. Then start dfs again.

How to indent/format a selection of code in Visual Studio Code with Ctrl + Shift + F

  • you can also indent a whole section by selecting it and clicking TAB
  • and also indent backward using Shift+TAB

And of course for auto indentation and formatting, following the language you're using, you can see which good extensions do the good job, and which formatters to install or which parameters settings to enable or set for each language and its available tools. Just make sure to read well the documentation of the extension, to install and set all what it need.

Up to now the indentation problem bothers me with Python when copy pasting a block of code. If that's the case, here is how you solve that: Visual Studio Code indentation for Python

Format ints into string of hex

With python 2.X, you can do the following:

numbers = [0, 1, 2, 3, 127, 200, 255]
print "".join(chr(i).encode('hex') for i in numbers)

print

'000102037fc8ff'

Classes vs. Modules in VB.NET

You must use a Module (rather than a Class) if you're creating Extension methods. In VB.NET I'm not aware of another option.

Being resistant to Modules myself, I just spent a worthless couple of hours trying to work out how to add some boilerplate code to resolve embedded assemblies in one, only to find out that Sub New() (Module) and Shared Sub New() (Class) are equivalent. (I didn't even know there was a callable Sub New() in a Module!)

So I just threw the EmbeddedAssembly.Load and AddHandler AppDomain.CurrentDomain.AssemblyResolve lines in there and Bob became my uncle.

Addendum: I haven't checked it out 100% yet, but I have an inkling that Sub New() runs in a different order in a Module than a Class, just going by the fact that I had to move some declarations to inside methods from outside to avoid errors.

HTML form do some "action" when hit submit button

Ok, I'll take a stab at this. If you want to work with PHP, you will need to install and configure both PHP and a webserver on your machine. This article might get you started: PHP Manual: Installation on Windows systems

Once you have your environment setup, you can start working with webforms. Directly From the article: Processing form data with PHP:

For this example you will need to create two pages. On the first page we will create a simple HTML form to collect some data. Here is an example:

<html>   
<head>
 <title>Test Page</title>
</head>   
<body>   
    <h2>Data Collection</h2><p>
    <form action="process.php" method="post">  
        <table>
            <tr>
                <td>Name:</td>
                <td><input type="text" name="Name"/></td>
            </tr>   
            <tr>
                <td>Age:</td>
                <td><input type="text" name="Age"/></td>
            </tr>   
            <tr>
                <td colspan="2" align="center">
                <input type="submit"/>
                </td>
            </tr>
        </table>
    </form>
</body>
</html>

This page will send the Name and Age data to the page process.php. Now lets create process.php to use the data from the HTML form we made:

<?php   
    print "Your name is ". $Name;   
    print "<br />";   
    print "You are ". $Age . " years old";   
    print "<br />";   $old = 25 + $Age;
    print "In 25 years you will be " . $old . " years old";   
?>

As you may be aware, if you leave out the method="post" part of the form, the URL with show the data. For example if your name is Bill Jones and you are 35 years old, our process.php page will display as http://yoursite.com/process.php?Name=Bill+Jones&Age=35 If you want, you can manually change the URL in this way and the output will change accordingly.

Additional JavaScript Example

This single file example takes the html from your question and ties the onSubmit event of the form to a JavaScript function that pulls the values of the 2 textboxes and displays them in an alert box.

Note: document.getElementById("fname").value gets the object with the ID tag that equals fname and then pulls it's value - which in this case is the text in the First Name textbox.

 <html>
    <head>
     <script type="text/javascript">
     function ExampleJS(){
        var jFirst = document.getElementById("fname").value;
        var jLast = document.getElementById("lname").value;
        alert("Your name is: " + jFirst + " " + jLast);
     }
     </script>

    </head>
    <body>
        <FORM NAME="myform" onSubmit="JavaScript:ExampleJS()">

             First name: <input type="text" id="fname" name="firstname" /><br />
             Last name:  <input type="text" id="lname" name="lastname" /><br />
            <input name="Submit"  type="submit" value="Update" />
        </FORM>
    </body>
</html>

Copy to Clipboard for all Browsers using javascript

For security reasons most browsers do not allow to modify the clipboard (except IE, of course...).

The only way to make a copy-to-clipboard function cross-browser compatible is to use Flash.

Xlib: extension "RANDR" missing on display ":21". - Trying to run headless Google Chrome

Try this:

Xvfb :21 -screen 0 1024x768x24 +extension RANDR &
Xvfb --help

+extension name        Enable extension
-extension name        Disable extension

Usage of unicode() and encode() functions in Python

str is text representation in bytes, unicode is text representation in characters.

You decode text from bytes to unicode and encode a unicode into bytes with some encoding.

That is:

>>> 'abc'.decode('utf-8')  # str to unicode
u'abc'
>>> u'abc'.encode('utf-8') # unicode to str
'abc'

UPD Sep 2020: The answer was written when Python 2 was mostly used. In Python 3, str was renamed to bytes, and unicode was renamed to str.

>>> b'abc'.decode('utf-8') # bytes to str
'abc'
>>> 'abc'.encode('utf-8'). # str to bytes
b'abc'

Difference between "git add -A" and "git add ."

Both git add . and git add -A will stage all new, modified and deleted files in the newer versions of Git.

The difference is that git add -A stages files in "higher, current and subdirectories" that belong to your working Git repository. But doing a git add . only stages files in the current directory and subdirectories following it (not the files lying outside, i.e., higher directories).

Here's an example:

/my-repo
  .git/
  subfolder/
    nested-file.txt
  rootfile.txt

If your current working directory is /my-repo, and you do rm rootfile.txt, then cd subfolder, followed by git add ., then it will not stage the deleted file. But doing git add -A will certainly stage this change no matter where you perform the command from.

Iterating over every two elements in a list

Here we can have alt_elem method which can fit in your for loop.

def alt_elem(list, index=2):
    for i, elem in enumerate(list, start=1):
        if not i % index:
           yield tuple(list[i-index:i])


a = range(10)
for index in [2, 3, 4]:
    print("With index: {0}".format(index))
    for i in alt_elem(a, index):
       print(i)

Output:

With index: 2
(0, 1)
(2, 3)
(4, 5)
(6, 7)
(8, 9)
With index: 3
(0, 1, 2)
(3, 4, 5)
(6, 7, 8)
With index: 4
(0, 1, 2, 3)
(4, 5, 6, 7)

Note: Above solution might not be efficient considering operations performed in func.

What is a C++ delegate?

Very simply, a delegate provides functionality for how a function pointer SHOULD work. There are many limitations of function pointers in C++. A delegate uses some behind-the-scenes template nastyness to create a template-class function-pointer-type-thing that works in the way you might want it to.

ie - you can set them to point at a given function and you can pass them around and call them whenever and wherever you like.

There are some very good examples here:

Add back button to action bar

this one worked for me:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_your_activity);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    // ... other stuff
}

@Override
public boolean onSupportNavigateUp(){
    finish();
    return true;
}

The method onSupportNavigateUp() is called when you use the back button in the SupportActionBar.

Purpose of a constructor in Java?

Constructors are used to initialize the instances of your classes. You use a constructor to create new objects often with parameters specifying the initial state or other important information about the object

From the official Java tutorial:

A class contains constructors that are invoked to create objects from the class blueprint. Constructor declarations look like method declarations—except that they use the name of the class and have no return type. For example, Bicycle has one constructor:

public Bicycle(int startCadence, int startSpeed, int startGear) {
    gear = startGear;
    cadence = startCadence;
    speed = startSpeed;
}

To create a new Bicycle object called myBike, a constructor is called by the new operator:

Bicycle myBike = new Bicycle(30, 0, 8);

new Bicycle(30, 0, 8) creates space in memory for the object and initializes its fields.

Although Bicycle only has one constructor, it could have others, including a no-argument constructor:

public Bicycle() { gear = 1; cadence = 10; speed = 0; }

Bicycle yourBike = new Bicycle(); invokes the no-argument constructor to create a new Bicycle object called yourBike.

How can I make git show a list of the files that are being tracked?

The accepted answer only shows files in the current directory's tree. To show all of the tracked files that have been committed (on the current branch), use

git ls-tree --full-tree --name-only -r HEAD
  • --full-tree makes the command run as if you were in the repo's root directory.
  • -r recurses into subdirectories. Combined with --full-tree, this gives you all committed, tracked files.
  • --name-only removes SHA / permission info for when you just want the file paths.
  • HEAD specifies which branch you want the list of tracked, committed files for. You could change this to master or any other branch name, but HEAD is the commit you have checked out right now.

This is the method from the accepted answer to the ~duplicate question https://stackoverflow.com/a/8533413/4880003.

Press Enter to move to next control

You could also write your own Control for this, in case you want to use this more often. Assuming you have multiple TextBoxes in a Grid, it would look something like this:

public class AdvanceOnEnterTextBox : UserControl
{

    TextBox _TextBox;
    public static readonly DependencyProperty TextProperty = DependencyProperty.Register("Text", typeof(String), typeof(AdvanceOnEnterTextBox), null);
    public static readonly DependencyProperty InputScopeProperty = DependencyProperty.Register("InputScope", typeof(InputScope), typeof(AdvanceOnEnterTextBox), null);


    public AdvanceOnEnterTextBox()
    {
        _TextBox = new TextBox();
        _TextBox.KeyDown += customKeyDown;
        Content = _TextBox;

    }


    /// <summary>
    /// Text for the TextBox
    /// </summary>
    public String Text
    {
        get { return _TextBox.Text; }
        set { _TextBox.Text = value; }
    }


    /// <summary>
    /// Inputscope for the Custom Textbox
    /// </summary>
    public InputScope InputScope
    {
        get { return _TextBox.InputScope; }
        set { _TextBox.InputScope = value; }
    }


    void customKeyDown(object sender, KeyEventArgs e)
    {
        if (!e.Key.Equals(Key.Enter)) return;

        var element = ((TextBox)sender).Parent as AdvanceOnEnterTextBox;
        if (element != null)
        {
            int currentElementPosition = ((Grid)element.Parent).Children.IndexOf(element);
            try
            {
                // Jump to the next AdvanceOnEnterTextBox (assuming, that Labels are inbetween).
                ((AdvanceOnEnterTextBox)((Grid)element.Parent).Children.ElementAt(currentElementPosition + 2)).Focus();
            }
            catch (Exception)
            {
                // Close Keypad if this was the last AdvanceOnEnterTextBox
                ((AdvanceOnEnterTextBox)((Grid)element.Parent).Children.ElementAt(currentElementPosition)).IsEnabled = false;
                ((AdvanceOnEnterTextBox)((Grid)element.Parent).Children.ElementAt(currentElementPosition)).IsEnabled = true;
            }
        }
    }
}

How do I get a list of installed CPAN modules?

perl -MFile::Find=find -MFile::Spec::Functions -Tlwe 'find { wanted => sub { print canonpath $_ if /\.pm\z/ }, no_chdir => 1 }, @INC'

How to filter by IP address in Wireshark?

Filtering IP Address in Wireshark:

(1)single IP filtering:

ip.addr==X.X.X.X

ip.src==X.X.X.X

ip.dst==X.X.X.X

(2)Multiple IP filtering based on logical conditions:

OR condition:

(ip.src==192.168.2.25)||(ip.dst==192.168.2.25)

AND condition:

(ip.src==192.168.2.25) && (ip.dst==74.125.236.16)

How to edit Docker container files from the host?

The best way is:

  $ docker cp CONTAINER:FILEPATH LOCALFILEPATH
  $ vi LOCALFILEPATH
  $ docker cp LOCALFILEPATH CONTAINER:FILEPATH

Limitations with $ docker exec: it can only attach to a running container.

Limitations with $ docker run: it will create a new container.

ERROR 1130 (HY000): Host '' is not allowed to connect to this MySQL server

Go to PhpMyAdmin, click on desired database, go to Privilages tab and create new user "remote", and give him all privilages and in host field set "Any host" option(%).

"Proxy server connection failed" in google chrome

Try following these steps:

  1. Run Chrome as Administrator.
  2. Go to the settings in Chrome.
  3. Go to Advanced Settings (its all the way down).
  4. Scroll to Network Section and click on ''Change proxy settings''.
  5. A window will pop up with the name ''Internet Properties''
  6. Click on ''LAN settings''
  7. Un-check ''Use a proxy server for your LAN''
  8. Check ''Automatically detect settings''
  9. Click everything ''OK'' and you are done!

Computing cross-correlation function?

To cross-correlate 1d arrays use numpy.correlate.

For 2d arrays, use scipy.signal.correlate2d.

There is also scipy.stsci.convolve.correlate2d.

There is also matplotlib.pyplot.xcorr which is based on numpy.correlate.

See this post on the SciPy mailing list for some links to different implementations.

Edit: @user333700 added a link to the SciPy ticket for this issue in a comment.

Adjust UILabel height depending on the text

Adding to the above answers:

This can be easily achieved via storyboard.

  1. Set constraint for UILabel.(In my case I did top, left and fixed width)
  2. Set Number of line to 0 in Attribute Inspector
  3. Set Line Break to WordWrap in Attribute Inspector.

UILabel Height Adjust

What's is the difference between include and extend in use case diagram?

I like to think of "includes" as a necessary prerequisite/accompaniment of the base use case. This means that the base use case cannot be considered complete without the use case it includes. I'll give the example of an e-commerce website that sells items to customers. There's no way you can pay for an item without first selecting that item and putting it in the cart. This implies that the use case "Pay for Item" includes "select item".

There are varying uses of extends but I like to think of it as an alternative that may or may not be used. For example - still on the e-commerce site. When paying for an item, you may choose to pay on delivery, pay using paypal or pay by card. These are all alternatives to the "pay for item" use case. I may choose any of these options depending on my preference.

For more clarity and the rules surrounding use cases, read my article here:

http://businessanalystlearnings.com/ba-techniques/2013/2/20/use-case-diagram-the-basics

What is the right way to populate a DropDownList from a database?

((TextBox)GridView1.Rows[e.NewEditIndex].Cells[3].Controls[0]).Enabled = false;

What is the full path to the Packages folder for Sublime text 2 on Mac OS Lion

1. Solution

Open Sublime Text console ? paste in opened field:

sublime.packages_path()

? Enter. You get result in console output.


2. Relevance

This answer is relevant for April 2018. In the future, the data of this answer may be obsolete.


3. Not recommended

I'm not recommended @osiris answer. Arguments:

  1. In new versions of Sublime Text and/or operating systems (e.g. Sublime Text 4, macOS 14) paths may be changed.
  2. It doesn't take portable Sublime Text on Windows. In portable Sublime Text on Windows another path of Packages folder.
  3. It less simple.

4. Additional link

Setting network adapter metric priority in Windows 7

I had the same problem on Windows 7 64-bit Pro. I adjusted network adapters binding using Control panel but nothing changed. Also metrics where showing that Win should use Ethernet adapter as primary, but it didn't.

Then a tried to uninstall Ethernet adapter driver and then install it again (without restart) and then I checked metrics for sure.

After this, Windows started prioritize Ethernet adapter.

How to find an available port?

If you want to create your own server using a ServerSocket, you can just have it pick a free port for you:

  ServerSocket serverSocket = new ServerSocket(0);
  int port = serverSocket.getLocalPort();

Other server implementations typically have similar support. Jetty for example picks a free port unless you explicitly set it:

  Server server = new Server();
  ServerConnector connector = new ServerConnector(server);
  // don't call: connector.setPort(port);
  server.addConnector(connector);
  server.start();
  int port = connector.getLocalPort();

Error: Cannot match any routes. URL Segment: - Angular 2

Solved myself. Done some small structural changes also. Route from Component1 to Component2 is done by a single <router-outlet>. Component2 to Comonent3 and Component4 is done by multiple <router-outlet name= "xxxxx"> The resulting contents are :

Component1.html

<nav>
    <a routerLink="/two" class="dash-item">Go to 2</a>
</nav>
    <router-outlet></router-outlet>

Component2.html

 <a [routerLink]="['/two', {outlets: {'nameThree': ['three']}}]">In Two...Go to 3 ...       </a>
 <a [routerLink]="['/two', {outlets: {'nameFour': ['four']}}]">   In Two...Go to 4 ...</a>

 <router-outlet name="nameThree"></router-outlet>
 <router-outlet name="nameFour"></router-outlet>

The '/two' represents the parent component and ['three']and ['four'] represents the link to the respective children of component2 . Component3.html and Component4.html are the same as in the question.

router.module.ts

const routes: Routes = [
{
    path: '',
    redirectTo: 'one',
    pathMatch: 'full'
},
{
    path: 'two',
    component: ClassTwo, children: [

        {
            path: 'three',
            component: ClassThree,
            outlet: 'nameThree'
        },
        {
            path: 'four',
            component: ClassFour,
            outlet: 'nameFour'
        }
    ]
},];

AngularJS : The correct way of binding to a service properties

The Most Elegant Solutions...

app.service('svc', function(){ this.attr = []; return this; });
app.controller('ctrl', function($scope, svc){
    $scope.attr = svc.attr || [];
    $scope.$watch('attr', function(neo, old){ /* if necessary */ });
});
app.run(function($rootScope, svc){
    $rootScope.svc = svc;
    $rootScope.$watch('svc', function(neo, old){ /* change the world */ });
});

Also, I write EDAs (Event-Driven Architectures) so I tend to do something like the following [oversimplified version]:

var Service = function Service($rootScope) {
    var $scope = $rootScope.$new(this);
    $scope.that = [];
    $scope.$watch('that', thatObserver, true);
    function thatObserver(what) {
        $scope.$broadcast('that:changed', what);
    }
};

Then, I put a listener in my controller on the desired channel and just keep my local scope up to date this way.

In conclusion, there's not much of a "Best Practice" -- rather, its mostly preference -- as long as you're keeping things SOLID and employing weak coupling. The reason I would advocate the latter code is because EDAs have the lowest coupling feasible by nature. And if you aren't too concerned about this fact, let us avoid working on the same project together.

Hope this helps...

Rebase array keys after unsetting elements

I use $arr = array_merge($arr); to rebase an array. Simple and straightforward.

How to convert list of key-value tuples into dictionary?

If Tuple has no key repetitions, it's Simple.

tup = [("A",0),("B",3),("C",5)]
dic = dict(tup)
print(dic)

If tuple has key repetitions.

tup = [("A",0),("B",3),("C",5),("A",9),("B",4)]
dic = {}
for i, j in tup:
    dic.setdefault(i,[]).append(j)
print(dic)

Regular expression to match standard 10 digit phone number

Perhaps the easiest one compare to several others.

\(?\d+\)?[-.\s]?\d+[-.\s]?\d+

It matches the following:

(555) 444-6789

555-444-6789

555.444.6789

555 444 6789

Angular 1 - get current URL parameters

You could inject $routeParams to your controller and access all the params that where used when the route was resolved.

E.g.:

// route was: app.dev/backend/:type/:id

function MyCtrl($scope, $routeParams, $log) {
    // use the params
    $log.info($routeParams.type, $routeParams.id);
};

See angular $routeParams documentation for further information.

How can I get the values of data attributes in JavaScript code?

You could also grab the attributes with the getAttribute() method which will return the value of a specific HTML attribute.

_x000D_
_x000D_
var elem = document.getElementById('the-span');_x000D_
_x000D_
var typeId = elem.getAttribute('data-typeId');_x000D_
var type   = elem.getAttribute('data-type');_x000D_
var points = elem.getAttribute('data-points');_x000D_
var important = elem.getAttribute('data-important');_x000D_
_x000D_
console.log(`typeId: ${typeId} | type: ${type} | points: ${points} | important: ${important}`_x000D_
);
_x000D_
<span data-typeId="123" data-type="topic" data-points="-1" data-important="true" id="the-span"></span>
_x000D_
_x000D_
_x000D_

Xcode 7.2 no matching provisioning profiles found

With Xcode 7.2.1, if you are certain that your provisioning profile is correct (it has the correct App ID and certificate, and the corresponding certificate exists in your Keychain Access) then set the Code Signing Identity and set the Provisioning Profile to Automatic.

How do I initialize a TypeScript Object with a JSON-Object?

The 4th option described above is a simple and nice way to do it, which has to be combined with the 2nd option in the case where you have to handle a class hierarchy like for instance a member list which is any of a occurences of subclasses of a Member super class, eg Director extends Member or Student extends Member. In that case you have to give the subclass type in the json format

get UTC time in PHP

Using gmdate will always return a GMT date. Syntax is same as for date.

Python - Using regex to find multiple matches and print them out

Using regexes for this purpose is the wrong approach. Since you are using python you have a really awesome library available to extract parts from HTML documents: BeautifulSoup.

Remove file from SVN repository without deleting local copy

Deleting files and folders

If you want to delete an item from the repository, but keep it locally as an unversioned file/folder, use Extended Context Menu ? Delete (keep local). You have to hold the Shift key while right clicking on the item in the explorer list pane (right pane) in order to see this in the extended context menu.

Delete completely:
right mouse click ? Menu ? Delete

Delete & Keep local:
Shift + right mouse click ? Menu ? Delete

How do you create a Swift Date object?

In, Swift 3.0 you have set date object for this way.

extension Date
{
    init(dateString:String) {
        let dateStringFormatter = DateFormatter()
        dateStringFormatter.dateFormat = "yyyy-MM-dd"
        dateStringFormatter.locale = Locale(identifier: "en_US_POSIX")
        let d = dateStringFormatter.date(from: dateString)!
        self(timeInterval:0, since:d)
    }
}

How to read all files in a folder from Java?

void getFiles(){
        String dirPath = "E:/folder_name";
        File dir = new File(dirPath);
        String[] files = dir.list();
        if (files.length == 0) {
            System.out.println("The directory is empty");
        } else {
            for (String aFile : files) {
                System.out.println(aFile);
            }
        }
    }

Avoid line break between html elements

If you need this for several words or elements, but can't apply it to a whole TD or similar, the Span tag can be used.

<span style="white-space: nowrap">Text to break together</span>
    or 
<span class=nobr>Text to break together</span>

If you use the class version, remember to set up the CSS as detailed in the accepted answer.

Getting error "The package appears to be corrupt" while installing apk file

In my case by making build, from Build> Build apks, it worked.

Automatically create requirements.txt

Not a complete solution, but may help to compile a shortlist on Linux.

grep --include='*.py' -rhPo '^\s*(from|import)\s+\w+' . | sed -r 's/\s*(import|from)\s+//' | sort -u > requirements.txt

How do I update/upsert a document in Mongoose?

//Here is my code to it... work like ninj

router.param('contractor', function(req, res, next, id) {
  var query = Contractors.findById(id);

  query.exec(function (err, contractor){
    if (err) { return next(err); }
    if (!contractor) { return next(new Error("can't find contractor")); }

    req.contractor = contractor;
    return next();
  });
});

router.get('/contractors/:contractor/save', function(req, res, next) {

    contractor = req.contractor ;
    contractor.update({'_id':contractor._id},{upsert: true},function(err,contractor){
       if(err){ 
            res.json(err);
            return next(); 
            }
    return res.json(contractor); 
  });
});


--

Run a script in Dockerfile

WORKDIR /scripts
COPY bootstrap.sh .
RUN ./bootstrap.sh 

Change grid interval and specify tick labels in Matplotlib

A subtle alternative to MaxNoe's answer where you aren't explicitly setting the ticks but instead setting the cadence.

import matplotlib.pyplot as plt
from matplotlib.ticker import (AutoMinorLocator, MultipleLocator)

fig, ax = plt.subplots(figsize=(10, 8))

# Set axis ranges; by default this will put major ticks every 25.
ax.set_xlim(0, 200)
ax.set_ylim(0, 200)

# Change major ticks to show every 20.
ax.xaxis.set_major_locator(MultipleLocator(20))
ax.yaxis.set_major_locator(MultipleLocator(20))

# Change minor ticks to show every 5. (20/4 = 5)
ax.xaxis.set_minor_locator(AutoMinorLocator(4))
ax.yaxis.set_minor_locator(AutoMinorLocator(4))

# Turn grid on for both major and minor ticks and style minor slightly
# differently.
ax.grid(which='major', color='#CCCCCC', linestyle='--')
ax.grid(which='minor', color='#CCCCCC', linestyle=':')

Matplotlib Custom Grid

How do I format axis number format to thousands with a comma in matplotlib?

Short answer without importing matplotlib as mpl

plt.gca().yaxis.set_major_formatter(plt.matplotlib.ticker.StrMethodFormatter('{x:,.0f}'))

Modified from @AlexG's answer

How can I solve a connection pool problem between ASP.NET and SQL Server?

I also got this exact error log on my AWS EC2 instance.

There were no connection leaks since I was just deploying the alpha application (no real users), and I confirmed with Activity Monitor and sp_who that there are in fact no connections to the database.

My issue was AWS related - more specifically, with the Security Groups. See, only certain security groups had access to the RDS server where I hosted the database. I added an ingress rule with authorize-security-group-ingress command to allow access to the correct EC2 instance to the RDS server by using --source-group-name parameter. The ingress rule was added, I could see that on the AWS UI - but I got this error.

When I removed and then added the ingress rule manually on AWS UI - suddenly the exception was no more and the app was working.

ImportError: numpy.core.multiarray failed to import

If you want a specific version:

pip install numpy==1.8

WPF Binding to parent DataContext

Because of things like this, as a general rule of thumb, I try to avoid as much XAML "trickery" as possible and keep the XAML as dumb and simple as possible and do the rest in the ViewModel (or attached properties or IValueConverters etc. if really necessary).

If possible I would give the ViewModel of the current DataContext a reference (i.e. property) to the relevant parent ViewModel

public class ThisViewModel : ViewModelBase
{
    TypeOfAncestorViewModel Parent { get; set; }
}

and bind against that directly instead.

<TextBox Text="{Binding Parent}" />

Gitignore not working

I solved my problem doing the following:

First of all, I am a windows user, but i have faced similar issue. So, I am posting my solution here.

There is one simple reason why sometimes the .gitignore doesn`t work like it is supposed to. It is due to the EOL conversion behavior.

Here is a quick fix for that

Edit > EOL Conversion > Windows Format > Save

You can blame your text editor settings for that.

For example:

As i am a windows developer, I typically use Notepad++ for editing my text unlike Vim users.

So what happens is, when i open my .gitignore file using Notepad++, it looks something like this:

## Ignore Visual Studio temporary files, build results, and
## files generated by popular Visual Studio add-ons.
##
## Get latest from https://github.com/github/gitignore/blob/master/VisualStudio.gitignore


# See https://help.github.com/ignore-files/ for more about ignoring files.

# User-specific files
*.suo
*.user
*.userosscache
*.sln.docstates
*.dll
*.force
# User-specific files (MonoDevelop/Xamarin Studio)
*.userprefs

If i open the same file using the default Notepad, this is what i get

## Ignore Visual Studio temporary files, build results, and ## files generated by popular Visual Studio add-ons. ## ## Get latest from  https://github.com/github/gitignore/blob/master/VisualStudio.gitignore # See https://help.github.com/ignore-files/ for more about ignoring files. # User-specific files *.suo *.user *.userosscache 

So, you might have already guessed by looking at the output. Everything in the .gitignore has become a one liner, and since there is a ## in the start, it acts as if everything is commented.

The way to fix this is simple: Just open your .gitignore file with Notepad++ , then do the following

Edit > EOL Conversion > Windows Format > Save

The next time you open the same file with the windows default notepad, everything should be properly formatted. Try it and see if this works for you.

How to get a date in YYYY-MM-DD format from a TSQL datetime field?

This solution works for me, simple and effective (with 126 too)

CONVERT(NVARCHAR(MAX), CAST(GETDATE() as date), 120)

Regex: Check if string contains at least one digit

The regular expression you are looking for is simply this:

[0-9]

You do not mention what language you are using. If your regular expression evaluator forces REs to be anchored, you need this:

.*[0-9].*

Some RE engines (modern ones!) also allow you to write the first as \d (mnemonically: digit) and the second would then become .*\d.*.

Is it possible to have a multi-line comments in R?

R Studio (and Eclipse + StatET): Highlight the text and use CTRL+SHIFT+C to comment multiple lines in Windows. Or, command+SHIFT+C in OS-X.

Typescript react - Could not find a declaration file for module ''react-materialize'. 'path/to/module-name.js' implicitly has an any type

I've had a same problem with react-redux types. The simplest solution was add to tsconfig.json:

"noImplicitAny": false

Example:

{
  "compilerOptions": {
    "allowJs": true,
    "allowSyntheticDefaultImports": true,
    "esModuleInterop": true,
    "isolatedModules": true,
    "jsx": "react",
    "lib": ["es6"],
    "moduleResolution": "node",
    "noEmit": true,
    "strict": true,
    "target": "esnext",
    "noImplicitAny": false,
  },
  "exclude": ["node_modules", "babel.config.js", "metro.config.js", "jest.config.js"]
}

How to Use Sockets in JavaScript\HTML?

How to Use Sockets in JavaScript/HTML?

There is no facility to use general-purpose sockets in JS or HTML. It would be a security disaster, for one.

There is WebSocket in HTML5. The client side is fairly trivial:

socket= new WebSocket('ws://www.example.com:8000/somesocket');
socket.onopen= function() {
    socket.send('hello');
};
socket.onmessage= function(s) {
    alert('got reply '+s);
};

You will need a specialised socket application on the server-side to take the connections and do something with them; it is not something you would normally be doing from a web server's scripting interface. However it is a relatively simple protocol; my noddy Python SocketServer-based endpoint was only a couple of pages of code.

In any case, it doesn't really exist, yet. Neither the JavaScript-side spec nor the network transport spec are nailed down, and no browsers support it.

You can, however, use Flash where available to provide your script with a fallback until WebSocket is widely available. Gimite's web-socket-js is one free example of such. However you are subject to the same limitations as Flash Sockets then, namely that your server has to be able to spit out a cross-domain policy on request to the socket port, and you will often have difficulties with proxies/firewalls. (Flash sockets are made directly; for someone without direct public IP access who can only get out of the network through an HTTP proxy, they won't work.)

Unless you really need low-latency two-way communication, you are better off sticking with XMLHttpRequest for now.

How do I extract specific 'n' bits of a 32-bit unsigned integer in C?

There is a single BEXTR (Bit field extract (with register)) x86 instruction on Intel and AMD CPUs and UBFX on ARM. There are intrinsic functions such as _bextr_u32() (link requires sign-in) that allow to invoke this instruction explicitly.

They implement (source >> offset) & ((1 << n) - 1) C code: get n continuous bits from source starting at the offset bit. Here's a complete function definition that handles edge cases:

#include <limits.h>

unsigned getbits(unsigned value, unsigned offset, unsigned n)
{
  const unsigned max_n = CHAR_BIT * sizeof(unsigned);
  if (offset >= max_n)
    return 0; /* value is padded with infinite zeros on the left */
  value >>= offset; /* drop offset bits */
  if (n >= max_n)
    return value; /* all  bits requested */
  const unsigned mask = (1u << n) - 1; /* n '1's */
  return value & mask;
}

For example, to get 3 bits from 2273 (0b100011100001) starting at 5-th bit, call getbits(2273, 5, 3)—it extracts 7 (0b111).

For example, say I want the first 17 bits of the 32-bit value; what is it that I should do?

unsigned first_bits = value & ((1u << 17) - 1); // & 0x1ffff

Assuming CHAR_BIT * sizeof(unsigned) is 32 on your system.

I presume I am supposed to use the modulus operator and I tried it and was able to get the last 8 bits and last 16 bits

unsigned last8bitsvalue  = value & ((1u <<  8) - 1); // & 0xff
unsigned last16bitsvalue = value & ((1u << 16) - 1); // & 0xffff

If the offset is always zero as in all your examples in the question then you don't need the more general getbits(). There is a special cpu instruction BLSMSK that helps to compute the mask ((1 << n) - 1).

Link to "pin it" on pinterest without generating a button

I had the same question. This works great in Wordpress!

<a href="//pinterest.com/pin/create/link/?url=<?php the_permalink();?>&amp;description=<?php the_title();?>">Pin this</a>

How can I parse a JSON file with PHP?

Try:

$string = file_get_contents("/home/michael/test.json");
$json = json_decode($string, true);

foreach ($json as $key => $value) {
    if (!is_array($value)) {
        echo $key . '=>' . $value . '<br />';
    } else {
        foreach ($value as $key => $val) {
            echo $key . '=>' . $val . '<br />';
        }
    }
}

Number of times a particular character appears in a string

You may do this completely in-line by replacing the desired character with an empty string, calling LENGTH function and substracting from the original string's length.

SELECT 
  CustomerName, 
  LENGTH(CustomerName) -
  LENGTH(REPLACE(CustomerName, ' ', '')) AS NumberOfSpaces
FROM Customers;

How do you add a Dictionary of items into another Dictionary

Currently, looking at the Swift Standard Library Reference for Dictionary, there is no way to easy update a dictionary with another one.

You can write an extension to do it

var dict1 = ["a" : "foo"]
var dict2 = ["b" : "bar"]

extension Dictionary {
    mutating func update(other:Dictionary) {
        for (key,value) in other {
            self.updateValue(value, forKey:key)
        }
    }
}

dict1.update(dict2)
// dict1 is now ["a" : "foo", "b" : "bar]

Screen width in React Native

If you have a Style component that you can require from your Component, then you could have something like this at the top of the file:

const Dimensions = require('Dimensions');

const window = Dimensions.get('window');

And then you could provide fulscreen: {width: window.width, height: window.height}, in your Style component. Hope this helps

What is the difference between YAML and JSON?

GIT and YAML

The other answers are good. Read those first. But I'll add one other reason to use YAML sometimes: git.

Increasingly, many programming projects use git repositories for distribution and archival. And, while a git repo's history can equally store JSON and YAML files, the "diff" method used for tracking and displaying changes to a file is line-oriented. Since YAML is forced to be line-oriented, any small changes in a YAML file are easier to see by a human.

It is true, of course, that JSON files can be "made pretty" by sorting the strings/keys and adding indentation. But this is not the default and I'm lazy.

Personally, I generally use JSON for system-to-system interaction. I often use YAML for config files, static files, and tracked files. (I also generally avoid adding YAML relational anchors. Life is too short to hunt down loops.)

Also, if speed and space are really a concern, I don't use either. You might want to look at BSON.

Checking character length in ruby

Ruby provides a built-in function for checking the length of a string. Say it's called s:

if s.length <= 25
  # We're OK
else
  # Too long
end

Select multiple elements from a list

mylist[c(5,7,9)] should do it.

You want the sublists returned as sublists of the result list; you don't use [[]] (or rather, the function is [[) for that -- as Dason mentions in comments, [[ grabs the element.

Flask - Calling python function on button OnClick event

Easiest solution

<button type="button" onclick="window.location.href='{{ url_for( 'move_forward') }}';">Forward</button>

How can I fix assembly version conflicts with JSON.NET after updating NuGet package references in a new ASP.NET MVC 5 project?

I had similar issue and just wanted to post an answer for others in my situation.

I have a solution running a ASP.NET Web Application with multiple other C# class lib projects.

My ASP.NET Web Application wasn't using json, but other projects where.

This is how I fixed it:

  1. I made sure all projects where using latest version (6) using NuGet Update on all projects currently using any version of json - this didn't fix the issue
  2. I added json to the web application using NuGet - this fixed the issue (let me dive into why):

Step 2 was first of all adding a configuration information for json, that suggest that all projects, use the latest version (6) no matter what version they have. Adding the assembly binding to Web.Config is most likely the fix.

However, step 2 also cleaned up som legacy code. It turned out we have previously used an old version (5) of json in our Web Application and the NuGet folders wasn't deleted when the reference was (I suspect: manually) removed. Adding the latest json (6), removed the old folders (json v5). This might be part of the fix as well.

Session unset, or session_destroy?

Unset will destroy a particular session variable whereas session_destroy() will destroy all the session data for that user.

It really depends on your application as to which one you should use. Just keep the above in mind.

unset($_SESSION['name']); // will delete just the name data

session_destroy(); // will delete ALL data associated with that user.

How to find column names for all tables in all databases in SQL Server

Better way for you

sp_MSForEachDB @command1='USE ?;
SELECT 
    Table_Catalog 
    ,Table_Schema
    ,Table_Name
    ,Column_Name
    ,Data_Type
    ,Character_Maximum_Length
FROM INFORMATION_SCHEMA.COLUMNS
WHERE COLUMN_NAME like ''%ColumnNameHere%'''

@Media min-width & max-width

The underlying issue is using max-device-width vs plain old max-width.

Using the "device" keyword targets physical dimension of the screen, not the width of the browser window.

For example:

@media only screen and (max-device-width: 480px) {
    /* STYLES HERE for DEVICES with physical max-screen width of 480px */
}

Versus

@media only screen and (max-width: 480px) {
    /* STYLES HERE for BROWSER WINDOWS with a max-width of 480px. 
       This will work on desktops when the window is narrowed.  */
}

C# Remove object from list of objects

If ChunkList is List<Chunk>, you can use the RemoveAll method:

ChunkList.RemoveAll(chunk => chunk.UniqueID == ChunkID);

How to convert a JSON string to a Map<String, String> with Jackson JSON

Warning you get is done by compiler, not by library (or utility method).

Simplest way using Jackson directly would be:

HashMap<String,Object> props;

// src is a File, InputStream, String or such
props = new ObjectMapper().readValue(src, new TypeReference<HashMap<String,Object>>() {});
// or:
props = (HashMap<String,Object>) new ObjectMapper().readValue(src, HashMap.class);
// or even just:
@SuppressWarnings("unchecked") // suppresses typed/untype mismatch warnings, which is harmless
props = new ObjectMapper().readValue(src, HashMap.class);

Utility method you call probably just does something similar to this.

Python object.__repr__(self) should be an expression?

>>> from datetime import date
>>>
>>> repr(date.today())        # calls date.today().__repr__()
'datetime.date(2009, 1, 16)'
>>> eval(_)                   # _ is the output of the last command
datetime.date(2009, 1, 16)

The output is a string that can be parsed by the python interpreter and results in an equal object.

If that's not possible, it should return a string in the form of <...some useful description...>.

Moment JS - check if a date is today or in the future

i wanted it for something else but eventually found a trick which you can try

somedate.calendar(compareDate, { sameDay: '[Today]'})=='Today'

_x000D_
_x000D_
var d = moment();_x000D_
 var today = moment();_x000D_
 _x000D_
 console.log("Usign today's date, is Date is Today? ",d.calendar(today, {_x000D_
    sameDay: '[Today]'})=='Today');_x000D_
    _x000D_
 var someRondomDate = moment("2012/07/13","YYYY/MM/DD");_x000D_
 _x000D_
 console.log("Usign Some Random Date, is Today ?",someRondomDate.calendar(today, {_x000D_
    sameDay: '[Today]'})=='Today');_x000D_
    _x000D_
  _x000D_
 var anotherRandomDate =  moment("2012/07/13","YYYY/MM/DD");_x000D_
 _x000D_
 console.log("Two Random Date are same date ? ",someRondomDate.calendar(anotherRandomDate, {_x000D_
    sameDay: '[Today]'})=='Today');
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.18.1/moment.min.js"></script>
_x000D_
_x000D_
_x000D_

Best way to work with dates in Android SQLite

"SELECT  "+_ID+" ,  "+_DESCRIPTION +","+_CREATED_DATE +","+_DATE_TIME+" FROM "+TBL_NOTIFICATION+" ORDER BY "+"strftime(%s,"+_DATE_TIME+") DESC";

How do I kill an Activity when the Back button is pressed?

public boolean onKeyDown(int keycode, KeyEvent event) {
    if (keycode == KeyEvent.KEYCODE_BACK) {
        moveTaskToBack(true);
    }
    return super.onKeyDown(keycode, event);
}

My app closed with above code.

How do I install Python packages on Windows?

I had problems in installing packages on Windows. Found the solution. It works in Windows7+. Mainly anything with Windows Powershell should be able to make it work. This can help you get started with it.

  • Firstly, you'll need to add python installation to your PATH variable. This should help.
  • You need to download the package in zip format that you are trying to install and unzip it. If it is some odd zip format use 7Zip and it should be extracted.
  • Navigate to the directory extracted with setup.py using Windows Powershell (Use link for it if you have problems)
  • Run the command python setup.py install

That worked for me when nothing else was making any sense. I use Python 2.7 but the documentation suggests that same would work for Python 3.x also.

Transfer git repositories from GitLab to GitHub - can we, how to and pitfalls (if any)?

If you want to migrate the repo including the wiki and all issues and milestones, you can use node-gitlab-2-github and GitLab to GitHub migration

Request exceeded the limit of 10 internal redirects due to probable configuration error

This error occurred to me when I was debugging the PHP header() function:

header('Location: /aaa/bbb/ccc'); // error

If I use a relative path it works:

header('Location: aaa/bbb/ccc'); // success, but not what I wanted

However when I use an absolute path like /aaa/bbb/ccc, it gives the exact error:

Request exceeded the limit of 10 internal redirects due to probable configuration error. Use 'LimitInternalRecursion' to increase the limit if necessary. Use 'LogLevel debug' to get a backtrace.

It appears the header function redirects internally without going HTTP at all which is weird. After some tests and trials, I found the solution of adding exit after header():

header('Location: /aaa/bbb/ccc');
exit;

And it works properly.

Regular Expressions: Is there an AND operator?

((yes).*(no))|((no).*(yes))

Will match sentence having both yes and no at the same time, regardless the order in which they appear:

Do i like cookies? **Yes**, i do. But milk - **no**, definitely no.

**No**, you may not have my phone. **Yes**, you may go f yourself.

Will both match, ignoring case.

How to sort an associative array by its values in Javascript?

i use $.each of jquery but you can make it with a for loop, an improvement is this:

        //.ArraySort(array)
        /* Sort an array
         */
        ArraySort = function(array, sortFunc){
              var tmp = [];
              var aSorted=[];
              var oSorted={};

              for (var k in array) {
                if (array.hasOwnProperty(k)) 
                    tmp.push({key: k, value:  array[k]});
              }

              tmp.sort(function(o1, o2) {
                    return sortFunc(o1.value, o2.value);
              });                     

              if(Object.prototype.toString.call(array) === '[object Array]'){
                  $.each(tmp, function(index, value){
                      aSorted.push(value.value);
                  });
                  return aSorted;                     
              }

              if(Object.prototype.toString.call(array) === '[object Object]'){
                  $.each(tmp, function(index, value){
                      oSorted[value.key]=value.value;
                  });                     
                  return oSorted;
              }               
     };

So now you can do

    console.log("ArraySort");
    var arr1 = [4,3,6,1,2,8,5,9,9];
    var arr2 = {'a':4, 'b':3, 'c':6, 'd':1, 'e':2, 'f':8, 'g':5, 'h':9};
    var arr3 = {a: 'green', b: 'brown', c: 'blue', d: 'red'};
    var result1 = ArraySort(arr1, function(a,b){return a-b});
    var result2 = ArraySort(arr2, function(a,b){return a-b});
    var result3 = ArraySort(arr3, function(a,b){return a>b});
    console.log(result1);
    console.log(result2);       
    console.log(result3);

C# Syntax - Example of a Lambda Expression - ForEach() over Generic List

public void Each<T>(IEnumerable<T> items, Action<T> action)
{
    foreach (var item in items)
        action(item);
}

... and call it thusly:

Each(myList, i => Console.WriteLine(i));

How can I create an executable JAR with dependencies using Maven?

I went through every one of these responses looking to make a fat executable jar containing all dependencies and none of them worked right. The answer is the shade plugin, its very easy and straightforward.

    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-shade-plugin</artifactId>
      <version>2.3</version>
      <executions>
         <!-- Run shade goal on package phase -->
        <execution>
        <phase>package</phase>
        <goals>
            <goal>shade</goal>
        </goals>
        <configuration>
          <transformers>
             <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                <mainClass>path.to.MainClass</mainClass>
             </transformer>
          </transformers>
        </configuration>
          </execution>
      </executions>
    </plugin>

Be aware that your dependencies need to have a scope of compile or runtime for this to work properly.

This example came from mkyong.com

How to SUM parts of a column which have same text value in different column in the same row

A PivotTable might suit, though I am not quite certain of the layout of your data:

SO19669814 example

The bold numbers (one of each pair of duplicates) need not be shown as the field does not have to be subtotalled eg:

SO19669814 second example

Cannot install packages inside docker Ubuntu image

Make sure you don't have any syntax errors in your Dockerfile as this can cause this error as well. A correct example is:

RUN apt-get update \
    && apt-get -y install curl \
    another-package

It was a combination of fixing a syntax error and adding apt-get update that solved the problem for me.

How to add/subtract dates with JavaScript?

Working with dates in javascript is always a bit of a hassle. I always end up using a library. Moment.js and XDate are both great:

http://momentjs.com/

http://arshaw.com/xdate/

Fiddle:

http://jsfiddle.net/39fWa/

var $output = $('#output'),
    tomorrow = moment().add('days', 1);

$('<pre />').appendTo($output).text(tomorrow);

tomorrow = new XDate().addDays(-1);

$('<pre />').appendTo($output).text(tomorrow);

?

Server http:/localhost:8080 requires a user name and a password. The server says: XDB

I'll assume that uninstall and reinstall Tomcat is not acceptable to you. The screen shot show basic auth challenge screen from browser and on the default app. So most likely you have set up users on the tomcat using the conf/tomcat-users.xml Try going through this guide https://tomcat.apache.org/tomcat-7.0-doc/realm-howto.html#UserDatabaseRealm

There are several other realms that you could have possibly used. Hopefully you will remember when you start reading the doc

#1130 - Host ‘localhost’ is not allowed to connect to this MySQL server

Use the IP instead:

DROP USER 'root'@'127.0.0.1'; GRANT ALL PRIVILEGES ON . TO 'root'@'%';

For more possibilities, see this link.

To create the root user, seeing as MySQL is local & all, execute the following from the command line (Start > Run > "cmd" without quotes):

mysqladmin -u root password 'mynewpassword'

Documentation, and Lost root access in MySQL.

Why is $$ returning the same id as the parent process?

You can use one of the following.

  • $! is the PID of the last backgrounded process.
  • kill -0 $PID checks whether it's still running.
  • $$ is the PID of the current shell.

How do I create an average from a Ruby array?

arr = [0,4,8,2,5,0,2,6]
average = arr.inject(&:+).to_f / arr.size
# => 3.375

"Error 1067: The process terminated unexpectedly" when trying to start MySQL

I had practically the same problem. in the log file I found this:

110903  9:09:39  InnoDB: 1.1.4 started; log sequence number 1595675
110903  9:09:40 [ERROR] Fatal error: Can't open and lock privilege tables: Incorrect key file for table 'user'; try to repair it

Apparently the user table has been corrupted. I replaced it with another copy (user.frm ; user.MYD ; user.MYI in mysql\data\mysql)
and thats works for me.

ps: am using xampp.

How to create and download a csv file from php script?

I don't have enough reputation to reply to @complex857 solution. It works great, but I had to add ; at the end of the Content-Disposition header. Without it the browser adds two dashes at the end of the filename (e.g. instead of "export.csv" the file gets saved as "export.csv--"). Probably it tries to sanitize \r\n at the end of the header line.

Correct line should look like this:

header('Content-Disposition: attachment;filename="'.$filename.'";');

In case when CSV has UTF-8 chars in it, you have to change the encoding to UTF-8 by changing the Content-Type line:

header('Content-Type: application/csv; charset=UTF-8');

Also, I find it more elegant to use rewind() instead of fseek():

rewind($f);

Thanks for your solution!

What does template <unsigned int N> mean?

Yes, it is a non-type parameter. You can have several kinds of template parameters

  • Type Parameters.
    • Types
    • Templates (only classes and alias templates, no functions or variable templates)
  • Non-type Parameters
    • Pointers
    • References
    • Integral constant expressions

What you have there is of the last kind. It's a compile time constant (so-called constant expression) and is of type integer or enumeration. After looking it up in the standard, i had to move class templates up into the types section - even though templates are not types. But they are called type-parameters for the purpose of describing those kinds nonetheless. You can have pointers (and also member pointers) and references to objects/functions that have external linkage (those that can be linked to from other object files and whose address is unique in the entire program). Examples:

Template type parameter:

template<typename T>
struct Container {
    T t;
};

// pass type "long" as argument.
Container<long> test;

Template integer parameter:

template<unsigned int S>
struct Vector {
    unsigned char bytes[S];
};

// pass 3 as argument.
Vector<3> test;

Template pointer parameter (passing a pointer to a function)

template<void (*F)()>
struct FunctionWrapper {
    static void call_it() { F(); }
};

// pass address of function do_it as argument.
void do_it() { }
FunctionWrapper<&do_it> test;

Template reference parameter (passing an integer)

template<int &A>
struct SillyExample {
    static void do_it() { A = 10; }
};

// pass flag as argument
int flag;
SillyExample<flag> test;

Template template parameter.

template<template<typename T> class AllocatePolicy>
struct Pool {
    void allocate(size_t n) {
        int *p = AllocatePolicy<int>::allocate(n);
    }
};

// pass the template "allocator" as argument. 
template<typename T>
struct allocator { static T * allocate(size_t n) { return 0; } };
Pool<allocator> test;

A template without any parameters is not possible. But a template without any explicit argument is possible - it has default arguments:

template<unsigned int SIZE = 3>
struct Vector {
    unsigned char buffer[SIZE];
};

Vector<> test;

Syntactically, template<> is reserved to mark an explicit template specialization, instead of a template without parameters:

template<>
struct Vector<3> {
    // alternative definition for SIZE == 3
};

Convert .cer certificate to .jks

keytool comes with the JDK installation (in the bin folder):

keytool -importcert -file "your.cer" -keystore your.jks -alias "<anything>"

This will create a new keystore and add just your certificate to it.

So, you can't convert a certificate to a keystore: you add a certificate to a keystore.

What does "TypeError 'xxx' object is not callable" means?

I came across this error message through a silly mistake. A classic example of Python giving you plenty of room to make a fool of yourself. Observe:

class DOH(object):
def __init__(self, property=None):
    self.property=property

def property():
    return property

x = DOH(1)
print(x.property())

Results

$ python3 t.py
Traceback (most recent call last):
  File "t.py", line 9, in <module>
    print(x.property())
TypeError: 'int' object is not callable

The problem here of course is that the function is overwritten with a property.

How to set gradle home while importing existing project in Android studio

I've stumble across this question, trying to build an Ionic + Cordova app using Gradle from Android Studio installation, rather that installing Gradle separately.

On Centos, the Gradle binary was here: /home/YOURUSERNAME/.gradle/wrapper/dists/gradle-VERSION-all/CUSTOM_HASH/gradle-VERSION/bin

So, I've added export PATH=/home/maxim/.gradle/wrapper/dists/gradle-4.1-all/bzyivzo6n839fup2jbap0tjew/gradle-4.1/bin:$PATH to my ~/.bashrc and ionic cordova run android command worked just fine.

How to extract a single value from JSON response?

Only suggestion is to access your resp_dict via .get() for a more graceful approach that will degrade well if the data isn't as expected.

resp_dict = json.loads(resp_str)
resp_dict.get('name') # will return None if 'name' doesn't exist

You could also add some logic to test for the key if you want as well.

if 'name' in resp_dict:
    resp_dict['name']
else:
    # do something else here.

Remove Blank option from Select Option with AngularJS

Change your code like this. You forget about the value inside option. Before you assign the ng-model. It must have a value. Only then it doesn't get the undefined value.

<div ng-app="MyApp1">
<div ng-controller="MyController">
    <input type="text" ng-model="feed.name" placeholder="Name" />
     <select ng-model="feed">
        <option ng-repeat="template in configs" value="template.value">{{template.name}}    
 </option>
    </select>
    </div>
 </div>

JS

 var MyApp=angular.module('MyApp1',[])
 MyApp.controller('MyController',function($scope) {  
      $scope.feed = 'config1';      
      $scope.configs = [
         {'name': 'Config 1', 'value': 'config1'},
         {'name': 'Config 2', 'value': 'config2'},
         {'name': 'Config 3', 'value': 'config3'}
      ];
 });

How to display text in pygame?

This is slighly more OS independent way:

# do this init somewhere
import pygame
pygame.init()
screen = pygame.display.set_mode((640, 480))
font = pygame.font.Font(pygame.font.get_default_font(), 36)

# now print the text
text_surface = font.render('Hello world', antialias=True, color=(0, 0, 0))
screen.blit(text_surface, dest=(0,0))