Programs & Examples On #Maven jetty plugin

maven-jetty-plugin is a Maven plug-in which embeds the Jetty webserver within a Maven build. It is configured in the Maven POM file. It is extremely useful for Rapid Application Development.

Could not open ServletContext resource [/WEB-INF/applicationContext.xml]

ContextLoaderListener has its own context which is shared by all servlets and filters. By default it will search /WEB-INF/applicationContext.xml

You can customize this by using

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/somewhere-else/root-context.xml</param-value>
</context-param>

on web.xml, or remove this listener if you don't need one.

Is there a way to pass jvm args via command line to maven?

I think MAVEN_OPTS would be most appropriate for you. See here: http://maven.apache.org/configure.html

In Unix:

Add the MAVEN_OPTS environment variable to specify JVM properties, e.g. export MAVEN_OPTS="-Xms256m -Xmx512m". This environment variable can be used to supply extra options to Maven.

In Win, you need to set environment variable via the dialogue box

Add ... environment variable by opening up the system properties (WinKey + Pause),... In the same dialog, add the MAVEN_OPTS environment variable in the user variables to specify JVM properties, e.g. the value -Xms256m -Xmx512m. This environment variable can be used to supply extra options to Maven.

What is HTML5 ARIA?

What is it?

WAI-ARIA stands for “Web Accessibility Initiative – Accessible Rich Internet Applications”. It is a set of attributes to help enhance the semantics of a web site or web application to help assistive technologies, such as screen readers for the blind, make sense of certain things that are not native to HTML. The information exposed can range from something as simple as telling a screen reader that activating a link or button just showed or hid more items, to widgets as complex as whole menu systems or hierarchical tree views.

This is achieved by applying roles and state attributes to HTML 4.01 or later markup that has no bearing on layout or browser functionality, but provides additional information for assistive technologies.

One corner stone of WAI-ARIA is the role attribute. It tells the browser to tell the assistive technology that the HTML element used is not actually what the element name suggests, but something else. While it originally is only a div element, this div element may be the container to a list of auto-complete items, in which case a role of “listbox” would be appropriate to use. Likewise, another div that is a child of that container div, and which contains a single option item, should then get a role of “option”. Two divs, but through the roles, totally different meaning. The roles are modeled after commonly used desktop application counterparts.

An exception to this are document landmark roles, which don’t change the actual meaning of the element in question, but provide information about this particular place in a document.

The second corner stone are WAI-ARIA states and properties. They define the state of certain native or WAI-ARIA elements such as if something is collapsed or expanded, a form element is required, something has a popup menu attached to it or the like. These are often dynamic and change their values throughout the lifecycle of a web application, and are usually manipulated via JavaScript.

What is it not?

WAI-ARIA is not intended to influence browser behavior. Unlike a real button element, for example, a div which you pour the role of “button” onto does not give you keyboard focusability, an automatic click handler when Space or Enter are being pressed on it, and other properties that are indiginous to a button. The browser itself does not know that a div with role of “button” is a button, only its accessibility API portion does.

As a consequence, this means that you absolutely have to implement keyboard navigation, focusability and other behavioural patterns known from desktop applications yourself. You can find some Advanced ARIA techniques Here.

When should I not use it?

Yes, that’s correct, this section comes first! Because the first rule of using WAI-ARIA is: Don’t use it unless you absolutely have to! The less WAI-ARIA you have, and the more you can count on using native HTML widgets, the better! There are some more rules to follow, you can check them out here.

How to determine the number of days in a month in SQL Server?

select add_months(trunc(sysdate,'MM'),1) -  trunc(sysdate,'MM') from dual;

Can a website detect when you are using Selenium with chromedriver?

Some sites are detecting this:

function d() {
try {
    if (window.document.$cdc_asdjflasutopfhvcZLmcfl_.cache_)
        return !0
} catch (e) {}

try {
    //if (window.document.documentElement.getAttribute(decodeURIComponent("%77%65%62%64%72%69%76%65%72")))
    if (window.document.documentElement.getAttribute("webdriver"))
        return !0
} catch (e) {}

try {
    //if (decodeURIComponent("%5F%53%65%6C%65%6E%69%75%6D%5F%49%44%45%5F%52%65%63%6F%72%64%65%72") in window)
    if ("_Selenium_IDE_Recorder" in window)
        return !0
} catch (e) {}

try {
    //if (decodeURIComponent("%5F%5F%77%65%62%64%72%69%76%65%72%5F%73%63%72%69%70%74%5F%66%6E") in document)
    if ("__webdriver_script_fn" in document)
        return !0
} catch (e) {}

How do I change column default value in PostgreSQL?

If you want to remove the default value constraint, you can do:

ALTER TABLE <table> ALTER COLUMN <column> DROP DEFAULT;

Is there Selected Tab Changed Event in the standard WPF Tab Control

If anyone use WPF Modern UI,they cant use OnTabSelected event.but they can use SelectedSourceChanged event.

like this

<mui:ModernTab Layout="Tab" SelectedSourceChanged="ModernTab_SelectedSourceChanged" Background="Blue" AllowDrop="True" Name="tabcontroller" >

C# code is

private void ModernTab_SelectedSourceChanged(object sender, SourceEventArgs e)
    {
          var links = ((ModernTab)sender).Links;

          var link = this.tabcontroller.Links.FirstOrDefault(l => l.Source == e.Source);

          if (link != null) {
              var index = this.tabcontroller.Links.IndexOf(link);
              MessageBox.Show(index.ToString());
          }            
    }

How to hide a div with jQuery?

$('#myDiv').hide(); hide function is used to edit content and show function is used to show again.

For more please click on this link.

phpmyadmin "no data received to import" error, how to fix?

just copy your source DataBase(from your PC C:\xampp\mysql\data\"your data base"), then copy it to the destination folder in your MAC (/Application/Xampp/xamppfiles/var/mysql).

don't forget to set the permission of the new copied folder(your DataBase) in your MAC otherwise you can't see your tables!

to set the permission: -go to the folder of your DataBase(/Application/Xampp/xamppfiles/var/mysql/"your data base") -right click on it -select Get info -in the sharing&permissions you must add your user account(i.e. administrator or everyone) -choose its privilege to Read & Write -choose Apply to enclosed items

enjoy your Database ;)

Working copy locked error in tortoise svn while committing

I had no idea what file was having the lock so what I did to get out of this issue was:

  1. Went to the highest level folder
  2. Click clean-up and also ticked from the cleaning-up methods --> Break locks

This worked for me.

SQLRecoverableException: I/O Exception: Connection reset

add java security in your run command

java -jar -Djava.security.egd="file:///dev/urandom" yourjarfilename.jar

How do I make a batch file terminate upon encountering an error?

@echo off

set startbuild=%TIME%

C:\WINDOWS\Microsoft.NET\Framework\v3.5\msbuild.exe c:\link.xml /flp1:logfile=c:\link\errors.log;errorsonly /flp2:logfile=c:\link\warnings.log;warningsonly || goto :error

copy c:\app_offline.htm "\\lawpccnweb01\d$\websites\OperationsLinkWeb\app_offline.htm"

del \\lawpccnweb01\d$\websites\OperationsLinkWeb\bin\ /Q

echo Start Copy: %TIME%

set copystart=%TIME%

xcopy C:\link\_PublishedWebsites\OperationsLink \\lawpccnweb01\d$\websites\OperationsLinkWeb\ /s /y /d

del \\lawpccnweb01\d$\websites\OperationsLinkWeb\app_offline.htm

echo Started Build: %startbuild%
echo Started Copy: %copystart%
echo Finished Copy: %TIME%

c:\link\warnings.log

:error

c:\link\errors.log

Resize HTML5 canvas to fit window

CSS

body { margin: 0; } 
canvas { display: block; } 

JavaScript

window.addEventListener("load", function()
{
    var canvas = document.createElement('canvas'); document.body.appendChild(canvas);
    var context = canvas.getContext('2d');

    function draw()
    {
        context.clearRect(0, 0, canvas.width, canvas.height);
        context.beginPath();
        context.moveTo(0, 0); context.lineTo(canvas.width, canvas.height); 
        context.moveTo(canvas.width, 0); context.lineTo(0, canvas.height); 
        context.stroke();
    }
    function resize()
    {
        canvas.width = window.innerWidth;
        canvas.height = window.innerHeight;
        draw();
    }
    window.addEventListener("resize", resize);
    resize();
});

Difference between null and empty ("") Java String

"" and null both are different . the first one means as part of string variable declaration the string constant has been created in the string pool and some memory has been assigned for the same.

But when we are declaring it with null then it has just been instantiated jvm , but no memory has been allocated for it. therefore if you are trying to access this object by checking it with "" - blank variable , it can't prevent nullpointerexception . Please find below one use-case.

public class StringCheck {

public static void main(String[] args) {
    // TODO Auto-generated method stub

    String s1 = "siddhartha";
    String s2 = "";
    String s3 = null;

    System.out.println("length s1 ="+s1.length());
    System.out.println("length s2 ="+s2.length());

    //this piece of code will still throw nullpointerexception . 
    if(s3 != ""){
        System.out.println("length s3 ="+s3.length());
    }
}

}

JavaScript is in array

in array example,Its same in php (in_array)

 var ur_fit = ["slim_fit", "tailored", "comfort"];
 var ur_length = ["length_short", "length_regular", "length_high"];
    if(ur_fit.indexOf(data_this)!=-1){
        alert("Value is avail in ur_fit array");
    }
    else if(ur_length.indexOf(data_this)!=-1){      
         alert("value is avail in ur_legth array"); 

    }

What does elementFormDefault do in XSD?

ElementFormDefault has nothing to do with namespace of the types in the schema, it's about the namespaces of the elements in XML documents which comply with the schema.

Here's the relevent section of the spec:

Element Declaration Schema

Component Property  {target namespace}
Representation      If form is present and its ·actual value· is qualified, 
                    or if form is absent and the ·actual value· of 
                    elementFormDefault on the <schema> ancestor is qualified, 
                    then the ·actual value· of the targetNamespace [attribute]
                    of the parent <schema> element information item, or 
                    ·absent· if there is none, otherwise ·absent·.

What that means is that the targetNamespace you've declared at the top of the schema only applies to elements in the schema compliant XML document if either elementFormDefault is "qualified" or the element is declared explicitly in the schema as having form="qualified".

For example: If elementFormDefault is unqualified -

<element name="name" type="string" form="qualified"></element>
<element name="page" type="target:TypePage"></element>

will expect "name" elements to be in the targetNamespace and "page" elements to be in the null namespace.

To save you having to put form="qualified" on every element declaration, stating elementFormDefault="qualified" means that the targetNamespace applies to each element unless overridden by putting form="unqualified" on the element declaration.

Invoking a jQuery function after .each() has completed

You have to queue the rest of your request for it to work.

var elems = $(parentSelect).nextAll();
var lastID = elems.length - 1;

elems.each( function(i) {
    $(this).fadeOut(200, function() { 
        $(this).remove(); 
        if (i == lastID) {
            $j(this).queue("fx",function(){ doMyThing;});
        }
    });
});

Error: Uncaught (in promise): Error: Cannot match any routes Angular 2

I also had the same issue. Tried all ways and it didn't work out until I added the following in app.module.ts

import { Ng4LoadingSpinnerModule } from 'ng4-loading-spinner';

And add the following in your imports in app.module.ts

Ng4LoadingSpinnerModule.forRoot()

This case might be rare but I hope this helps someone out there

DateTimePicker time picker in 24 hour but displaying in 12hr?

Meridian pertains to AM/PM, by setting it to false you're indicating you don't want AM/PM, therefore you want 24-hour clock implicitly.

$('#timepicker1').timepicker({showMeridian:false});

Renaming a branch in GitHub

I've found three commands on how you can change your Git branch name, and these commands are a faster way to do that:

git branch -m old_branch new_branch         # Rename branch locally
git push origin :old_branch                 # Delete the old branch
git push --set-upstream origin new_branch   # Push the new branch, set local branch to track the new remote

If you need step-by-step you can read this great article:

How to Rename Git Local and Remote Branches

Concatenate rows of two dataframes in pandas

Thanks to @EdChum I was struggling with same problem especially when indexes do not match. Unfortunatly in pandas guide this case is missed (when you for example delete some rows)

import pandas as pd
t=pd.DataFrame()
t['a']=[1,2,3,4]
t=t.loc[t['a']>1] #now index starts from 1

u=pd.DataFrame()
u['b']=[1,2,3] #index starts from 0

#option 1
#keep index of t
u.index = t.index 

#option 2
#index of t starts from 0
t.reset_index(drop=True, inplace=True)

#now concat will keep number of rows 
r=pd.concat([t,u], axis=1)

Are multiple `.gitignore`s frowned on?

There are many scenarios where you want to commit a directory to your Git repo but without the files in it, for example the logs, cache, uploads directories etc.

So what I always do is to add a .gitignore file in those directories with the following content:

*
!.gitignore

With this .gitignore file, Git will not track any files in those directories yet still allow me to add the .gitignore file and hence the directory itself to the repo.

When should I use GC.SuppressFinalize()?

SuppressFinalize should only be called by a class that has a finalizer. It's informing the Garbage Collector (GC) that this object was cleaned up fully.

The recommended IDisposable pattern when you have a finalizer is:

public class MyClass : IDisposable
{
    private bool disposed = false;

    protected virtual void Dispose(bool disposing)
    {
        if (!disposed)
        {
            if (disposing)
            {
                // called via myClass.Dispose(). 
                // OK to use any private object references
            }
            // Release unmanaged resources.
            // Set large fields to null.                
            disposed = true;
        }
    }

    public void Dispose() // Implement IDisposable
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    ~MyClass() // the finalizer
    {
        Dispose(false);
    }
}

Normally, the CLR keeps tabs on objects with a finalizer when they are created (making them more expensive to create). SuppressFinalize tells the GC that the object was cleaned up properly and doesn't need to go onto the finalizer queue. It looks like a C++ destructor, but doesn't act anything like one.

The SuppressFinalize optimization is not trivial, as your objects can live a long time waiting on the finalizer queue. Don't be tempted to call SuppressFinalize on other objects mind you. That's a serious defect waiting to happen.

Design guidelines inform us that a finalizer isn't necessary if your object implements IDisposable, but if you have a finalizer you should implement IDisposable to allow deterministic cleanup of your class.

Most of the time you should be able to get away with IDisposable to clean up resources. You should only need a finalizer when your object holds onto unmanaged resources and you need to guarantee those resources are cleaned up.

Note: Sometimes coders will add a finalizer to debug builds of their own IDisposable classes in order to test that code has disposed their IDisposable object properly.

public void Dispose() // Implement IDisposable
{
    Dispose(true);
#if DEBUG
    GC.SuppressFinalize(this);
#endif
}

#if DEBUG
~MyClass() // the finalizer
{
    Dispose(false);
}
#endif

Tree data structure in C#

I have a little extension to the solutions.

Using a recursive generic declaration and a deriving subclass you can better concentrate on your actual target.

Notice, it's different from a non generic implementation, you don`t need to cast 'node' in 'NodeWorker'.

Here's my example:

public class GenericTree<T> where T : GenericTree<T> // recursive constraint  
{
  // no specific data declaration  

  protected List<T> children;

  public GenericTree()
  {
    this.children = new List<T>();
  }

  public virtual void AddChild(T newChild)
  {
    this.children.Add(newChild);
  }

  public void Traverse(Action<int, T> visitor)
  {
    this.traverse(0, visitor);
  }

  protected virtual void traverse(int depth, Action<int, T> visitor)
  {
    visitor(depth, (T)this);
    foreach (T child in this.children)
      child.traverse(depth + 1, visitor);
  }
}

public class GenericTreeNext : GenericTree<GenericTreeNext> // concrete derivation
{
  public string Name {get; set;} // user-data example

  public GenericTreeNext(string name)
  {
    this.Name = name;
  }
}

static void Main(string[] args)  
{  
  GenericTreeNext tree = new GenericTreeNext("Main-Harry");  
  tree.AddChild(new GenericTreeNext("Main-Sub-Willy"));  
  GenericTreeNext inter = new GenericTreeNext("Main-Inter-Willy");  
  inter.AddChild(new GenericTreeNext("Inter-Sub-Tom"));  
  inter.AddChild(new GenericTreeNext("Inter-Sub-Magda"));  
  tree.AddChild(inter);  
  tree.AddChild(new GenericTreeNext("Main-Sub-Chantal"));  
  tree.Traverse(NodeWorker);  
}  

static void NodeWorker(int depth, GenericTreeNext node)  
{                                // a little one-line string-concatenation (n-times)
  Console.WriteLine("{0}{1}: {2}", String.Join("   ", new string[depth + 1]), depth, node.Name);  
}  

Notepad++ Regular expression find and delete a line

Step 1

  • SearchFind → (goto Tab) Mark
  • Find what: ^Session.*$
  • Enable the checkbox Bookmark line
  • Enable the checkbox Regular expression (under Search Mode)
  • Click Mark All (this will find the regex and highlights all the lines and bookmark them)

Step 2

  • SearchBookmarkRemove Bookmarked Lines

How to get highcharts dates in the x axis?

Check this sample out from the Highcharts API.

Replace this

return Highcharts.dateFormat('%a %d %b', this.value);

With this

return Highcharts.dateFormat('%a %d %b %H:%M:%S', this.value);

Look here about the dateFormat() function.

Also see - tickInterval and pointInterval

rsync: difference between --size-only and --ignore-times

The short answer is that --ignore-times does more than its name implies. It ignores both the time and size. In contrast, --size-only does exactly what it says.


The long answer is that rsync has three ways to decide if a file is outdated:

  1. Compare the size of source and destination.
  2. Compare the timestamp of source and destination.
  3. Compare the static checksum of source and destination.

These checks are performed before transferring data. Notably, this means the static checksum is distinct from the stream checksum - the later is computed while transferring data.

By default, rsync uses only 1 and 2. Both 1 and 2 can be acquired together by a single stat, whereas 3 requires reading the entire file (this is independent from reading the file for transfer). Assuming only one modifier is specified, that means the following:

  • By using --size-only, only 1 is performed - timestamps and checksum are ignored. A file is copied unless its size is identical on both ends.

  • By using --ignore-times, neither of 1, 2 or 3 is performed. A file is always copied.

  • By using --checksum, 3 is used in addition to 1, but 2 is not performed. A file is copied unless size and checksum match. The checksum is only computed if size matches.

How do you round a double in Dart to a given degree of precision AFTER the decimal point?

num.toStringAsFixed() rounds. This one turns you num (n) into a string with the number of decimals you want (2), and then parses it back to your num in one sweet line of code:

n = num.parse(n.toStringAsFixed(2));

How do I shutdown, restart, or log off Windows via a bat file?

The most common ways to use the shutdown command are:

  • shutdown -s — Shuts down.
  • shutdown -r — Restarts.
  • shutdown -l — Logs off.
  • shutdown -h — Hibernates.

    Note: There is a common pitfall wherein users think -h means "help" (which it does for every other command-line program... except shutdown.exe, where it means "hibernate"). They then run shutdown -h and accidentally turn off their computers. Watch out for that.

  • shutdown -i — "Interactive mode". Instead of performing an action, it displays a GUI dialog.

  • shutdown -a — Aborts a previous shutdown command.

The commands above can be combined with these additional options:

  • -f — Forces programs to exit. Prevents the shutdown process from getting stuck.
  • -t <seconds> — Sets the time until shutdown. Use -t 0 to shutdown immediately.
  • -c <message> — Adds a shutdown message. The message will end up in the Event Log.
  • -y — Forces a "yes" answer to all shutdown queries.

    Note: This option is not documented in any official documentation. It was discovered by these StackOverflow users.


I want to make sure some other really good answers are also mentioned along with this one. Here they are in no particular order.

how to get domain name from URL

I once had to write such a regex for a company I worked for. The solution was this:

  • Get a list of every ccTLD and gTLD available. Your first stop should be IANA. The list from Mozilla looks great at first sight, but lacks ac.uk for example so for this it is not really usable.
  • Join the list like the example below. A warning: Ordering is important! If org.uk would appear after uk then example.org.uk would match org instead of example.

Example regex:

.*([^\.]+)(com|net|org|info|coop|int|co\.uk|org\.uk|ac\.uk|uk|__and so on__)$

This worked really well and also matched weird, unofficial top-levels like de.com and friends.

The upside:

  • Very fast if regex is optimally ordered

The downside of this solution is of course:

  • Handwritten regex which has to be updated manually if ccTLDs change or get added. Tedious job!
  • Very large regex so not very readable.

How to find out when a particular table was created in Oracle?

You copy and paste the following code. It will display all the tables with Name and Created Date

SELECT object_name,created FROM user_objects
WHERE object_name LIKE  '%table_name%'
AND object_type = 'TABLE'; 

Note: Replace '%table_name%' with the table name you are looking for.

Invalid use side-effecting operator Insert within a function

Functions cannot be used to modify base table information, use a stored procedure.

How to move text up using CSS when nothing is working

used the following snippet and it worked fine..

.smallText .bmv-disclaimer {
   height: 40px;
}

Attempt by security transparent method 'WebMatrix.WebData.PreApplicationStartCode.Start()'

I have removed it from my references.Then run this in Package Manager Console

Install-Package WebMatrix.Data

Finally add WebMatrix.WebData assembly to references,and rebuild project.It works for me.I hope it solves your problem too.

Common MySQL fields and their appropriate data types

Since you're going to be dealing with data of a variable length (names, email addresses), then you'd be wanting to use VARCHAR. The amount of space taken up by a VARCHAR field is [field length] + 1 bytes, up to max length 255, so I wouldn't worry too much about trying to find a perfect size. Take a look at what you'd imagine might be the longest length might be, then double it and set that as your VARCHAR limit. That said...:

I generally set email fields to be VARCHAR(100) - i haven't come up with a problem from that yet. Names I set to VARCHAR(50).

As the others have said, phone numbers and zip/postal codes are not actually numeric values, they're strings containing the digits 0-9 (and sometimes more!), and therefore you should treat them as a string. VARCHAR(20) should be well sufficient.

Note that if you were to store phone numbers as integers, many systems will assume that a number starting with 0 is an octal (base 8) number! Therefore, the perfectly valid phone number "0731602412" would get put into your database as the decimal number "124192010"!!

Does C have a string type?

C does not have its own String data type like Java.

Only we can declare String datatype in C using character array or character pointer For example :

 char message[10]; 
 or 
 char *message;

But you need to declare at least:

    char message[14]; 

to copy "Hello, world!" into message variable.

  • 13 : length of the "Hello, world!"
  • 1 : for '\0' null character that identifies end of the string

Adding a simple UIAlertView

As a supplementary to the two previous answers (of user "sudo rm -rf" and "Evan Mulawski"), if you don't want to do anything when your alert view is clicked, you can just allocate, show and release it. You don't have to declare the delegate protocol.

How to delete a file or folder?

I recommend using subprocess if writing a beautiful and readable code is your cup of tea:

import subprocess
subprocess.Popen("rm -r my_dir", shell=True)

And if you are not a software engineer, then maybe consider using Jupyter; you can simply type bash commands:

!rm -r my_dir

Traditionally, you use shutil:

import shutil
shutil.rmtree(my_dir) 

How do you query for "is not null" in Mongo?

db.collection_name.find({"filed_name":{$exists:true}});

fetch documents that contain this filed_name even it is null.

Warning

db.collection_name.find({"filed_name":{$ne:null}});

fetch documents that its field_name has a value $ne to null but this value could be an empty string also.

My proposition:

db.collection_name.find({ "field_name":{$ne:null},$where:"this.field_name.length >0"})

How to initialize a struct in accordance with C programming language standards

I didn't like any of these answers so I made my own. I don't know if this is ANSI C or not, it's just GCC 4.2.1 in it's default mode. I never can remember the bracketing so I start with a subset of my data and do battle with compiler error messages until it shuts up. Readability is my first priority.

    // in a header:
    typedef unsigned char uchar;

    struct fields {
      uchar num;
      uchar lbl[35];
    };

    // in an actual c file (I have 2 in this case)
    struct fields labels[] = {
      {0,"Package"},
      {1,"Version"},
      {2,"Apport"},
      {3,"Architecture"},
      {4,"Bugs"},
      {5,"Description-md5"},
      {6,"Essential"},
      {7,"Filename"},
      {8,"Ghc-Package"},
      {9,"Gstreamer-Version"},
      {10,"Homepage"},
      {11,"Installed-Size"},
      {12,"MD5sum"},
      {13,"Maintainer"},
      {14,"Modaliases"},
      {15,"Multi-Arch"},
      {16,"Npp-Description"},
      {17,"Npp-File"},
      {18,"Npp-Name"},
      {19,"Origin"}
    };

The data may start life as a tab-delimited file that you search-replace to massage into something else. Yes, this is Debian stuff. So one outside pair of {} (indicating the array), then another pair for each struct inside. With commas between. Putting things in a header isn't strictly necessary, but I've got about 50 items in my struct so I want them in a separate file, both to keep the mess out of my code and so it's easier to replace.

How to listen for 'props' changes

Not sure if you have resolved it (and if I understand correctly), but here's my idea:

If parent receives myProp, and you want it to pass to child and watch it in child, then parent has to have copy of myProp (not reference).

Try this:

new Vue({
  el: '#app',
  data: {
    text: 'Hello'
  },
  components: {
    'parent': {
      props: ['myProp'],
      computed: {
        myInnerProp() { return myProp.clone(); } //eg. myProp.slice() for array
      }
    },
    'child': {
      props: ['myProp'],
      watch: {
        myProp(val, oldval) { now val will differ from oldval }
      }
    }
  }
}

and in html:

<child :my-prop="myInnerProp"></child>

actually you have to be very careful when working on complex collections in such situations (passing down few times)

Can I add a UNIQUE constraint to a PostgreSQL table, after it's already created?

Yes, you can add a UNIQUE constraint after the fact. However, if you have non-unique entries in your table Postgres will complain about it until you correct them.

How to Create a real one-to-one relationship in SQL Server

What about this ?

create table dbo.[Address]
(
Id int identity not null,
City nvarchar(255) not null,
Street nvarchar(255) not null,
CONSTRAINT PK_Address PRIMARY KEY (Id)
)

create table dbo.[Person]
(
Id int identity not null,
AddressId int not null,
FirstName nvarchar(255) not null,
LastName nvarchar(255) not null,
CONSTRAINT PK_Person PRIMARY KEY (Id),
CONSTRAINT FK_Person_Address FOREIGN KEY (AddressId) REFERENCES dbo.[Address] (Id)
)

How can I select the row with the highest ID in MySQL?

SELECT MAX(id) FROM TABELNAME

This identifies the largest id and returns the value

Convert JSON String To C# Object

add this ddl to reference to your project: System.Web.Extensions.dll

use this namespace: using System.Web.Script.Serialization;

public class IdName
{
    public int Id { get; set; }
    public string Name { get; set; }
}


   string jsonStringSingle = "{'Id': 1, 'Name':'Thulasi Ram.S'}".Replace("'", "\"");
   var entity = new JavaScriptSerializer().Deserialize<IdName>(jsonStringSingle);

   string jsonStringCollection = "[{'Id': 2, 'Name':'Thulasi Ram.S'},{'Id': 2, 'Name':'Raja Ram.S'},{'Id': 3, 'Name':'Ram.S'}]".Replace("'", "\"");
   var collection = new JavaScriptSerializer().Deserialize<IEnumerable<IdName>>(jsonStringCollection);

How do files get into the External Dependencies in Visual Studio C++?

To resolve external dependencies within project. below things are important..
1. The compiler should know that where are header '.h' files located in workspace.
2. The linker able to find all specified  all '.lib' files & there names for current project.

So, Developer has to specify external dependencies for Project as below..

1. Select Project in Solution explorer.

2 . Project Properties -> Configuration Properties -> C/C++ -> General
specify all header files in "Additional Include Directories".

3.  Project Properties -> Configuration Properties -> Linker -> General
specify relative path for all lib files in "Additional Library Directories".

enter image description here enter image description here

How to remove an element from the flow?

position: fixed; will also "pop" an element out of the flow, as you say. :)

position: absolute must be accompanied by a position. e.g. top: 1rem; left: 1rem

position: fixed however, will place the element where it would normally appear according to the document flow, but prevent it from moving after that. It also effectively set's the height to 0px (with regards to the dom) so that the next element shifts up over it.

This can be pretty cool, because you can set position: fixed; z-index: 1 (or whatever z-index you need) so that it "pops" over the next element.

This is especially useful for fixed position headers that stay at the top when you scroll, for example.

How do I copy a version of a single file from one git branch to another?

Run this from the branch where you want the file to end up:

git checkout otherbranch myfile.txt

General formulas:

git checkout <commit_hash> <relative_path_to_file_or_dir>
git checkout <remote_name>/<branch_name> <file_or_dir>

Some notes (from comments):

  • Using the commit hash you can pull files from any commit
  • This works for files and directories
  • overwrites the file myfile.txt and mydir
  • Wildcards don't work, but relative paths do
  • Multiple paths can be specified

an alternative:

git show commit_id:path/to/file > path/to/file

Calendar Recurring/Repeating Events - Best Storage Method

While the proposed solutions work, I was trying to implement with Full Calendar and it would require over 90 database calls for each view (as it loads current, previous, and next month), which, I wasn't too thrilled about.

I found an recursion library https://github.com/tplaner/When where you simply store the rules in the database and one query to pull all the relevant rules.

Hopefully this will help someone else, as I spent so many hours trying to find a good solution.

Edit: This Library is for PHP

"Cannot instantiate the type..."

Queue is an Interface so you can not initiate it directly. Initiate it by one of its implementing classes.

From the docs all known implementing classes:

  • AbstractQueue
  • ArrayBlockingQueue
  • ArrayDeque
  • ConcurrentLinkedQueue
  • DelayQueue
  • LinkedBlockingDeque
  • LinkedBlockingQueue
  • LinkedList
  • PriorityBlockingQueue
  • PriorityQueue
  • SynchronousQueue

You can use any of above based on your requirement to initiate a Queue object.

Oracle 'Partition By' and 'Row_Number' keyword

That selects the row number per country code, account, and currency. So, the rows with country code "US", account "XYZ" and currency "$USD" will each get a row number assigned from 1-n; the same goes for every other combination of those columns in the result set.

This query is kind of funny, because the order by clause does absolutely nothing. All the rows in each partition have the same country code, account, and currency, so there's no point ordering by those columns. The ultimate row numbers assigned in this particular query will therefore be unpredictable.

Hope that helps...

How to query the permissions on an Oracle directory?

With Oracle 11g R2 (at least with 11.2.02) there is a view named datapump_dir_objs.

SELECT * FROM datapump_dir_objs;

The view shows the NAME of the directory object, the PATH as well as READ and WRITE permissions for the currently connected user. It does not show any directory objects which the current user has no permission to read from or write to, though.

Vertical divider CSS

<div class="headerdivider"></div>

and

.headerdivider {
    border-left: 1px solid #38546d;
    background: #16222c;
    width: 1px;
    height: 80px;
    position: absolute;
    right: 250px;
    top: 10px;
}

Selenium WebDriver findElement(By.xpath()) not working for me

You haven't specified what kind of html element you are trying to do an absolute xpath search on. In your case, it's the input element.

Try this:

element = findElement(By.xpath("//input[@class='t-TextBox' and @type='email' and @test-    
id='test-username']");

selected value get from db into dropdown select box option using php mysql error

THE EASIEST SOLUTION

It will add an extra in your options but your problem will be solved.

<?php 
    if ($editing == Yes) {
        echo "<option value=\".$MyValue.\" SELECTED>".$MyValue."</option>";
    }
?>

Is there a Python equivalent to Ruby's string interpolation?

You can also have this

name = "Spongebob Squarepants"
print "Who lives in a Pineapple under the sea? \n{name}.".format(name=name)

http://docs.python.org/2/library/string.html#formatstrings

Getting a union of two arrays in JavaScript

I would first concatenate the arrays, then I would return only the unique value.

You have to create your own function to return unique values. Since it is a useful function, you might as well add it in as a functionality of the Array.

In your case with arrays array1 and array2 it would look like this:

  1. array1.concat(array2) - concatenate the two arrays
  2. array1.concat(array2).unique() - return only the unique values. Here unique() is a method you added to the prototype for Array.

The whole thing would look like this:

_x000D_
_x000D_
Array.prototype.unique = function () {_x000D_
    var r = new Array();_x000D_
    o: for(var i = 0, n = this.length; i < n; i++)_x000D_
    {_x000D_
        for(var x = 0, y = r.length; x < y; x++)_x000D_
        {_x000D_
            if(r[x]==this[i])_x000D_
            {_x000D_
                continue o;_x000D_
            }_x000D_
        }_x000D_
        r[r.length] = this[i];_x000D_
    }_x000D_
    return r;_x000D_
}_x000D_
var array1 = [34,35,45,48,49];_x000D_
var array2 = [34,35,45,48,49,55];_x000D_
_x000D_
// concatenate the arrays then return only the unique values_x000D_
console.log(array1.concat(array2).unique());
_x000D_
_x000D_
_x000D_

Node.js Write a line into a .txt file

Step 1

If you have a small file Read all the file data in to memory

Step 2

Convert file data string into Array

Step 3

Search the array to find a location where you want to insert the text

Step 4

Once you have the location insert your text

yourArray.splice(index,0,"new added test");

Step 5

convert your array to string

yourArray.join("");

Step 6

write your file like so

fs.createWriteStream(yourArray);

This is not advised if your file is too big

Android: Create a toggle button with image and no text

ToggleButton inherits from TextView so you can set drawables to be displayed at the 4 borders of the text. You can use that to display the icon you want on top of the text and hide the actual text

<ToggleButton
    android:id="@+id/toggleButton1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:drawableTop="@android:drawable/ic_menu_info_details"
    android:gravity="center"
    android:textOff=""
    android:textOn=""
    android:textSize="0dp" />

The result compared to regular ToggleButton looks like

enter image description here

The seconds option is to use an ImageSpan to actually replace the text with an image. Looks slightly better since the icon is at the correct position but can't be done with layout xml directly.

You create a plain ToggleButton

<ToggleButton
    android:id="@+id/toggleButton3"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:checked="false" />

Then set the "text" programmatially

ToggleButton button = (ToggleButton) findViewById(R.id.toggleButton3);
ImageSpan imageSpan = new ImageSpan(this, android.R.drawable.ic_menu_info_details);
SpannableString content = new SpannableString("X");
content.setSpan(imageSpan, 0, 1, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
button.setText(content);
button.setTextOn(content);
button.setTextOff(content);

The result here in the middle - icon is placed slightly lower since it takes the place of the text.

enter image description here

Running a command as Administrator using PowerShell?

Here is an addition to Shay Levi's suggestion (just add these lines at the beginning of a script):

if (-NOT ([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole] "Administrator"))  
{  
  $arguments = "& '" +$myinvocation.mycommand.definition + "'"
  Start-Process powershell -Verb runAs -ArgumentList $arguments
  Break
}

This results in the current script being passed to a new powershell process in Administrator mode (if current User has access to Administrator mode and the script is not launched as Administrator).

SQLAlchemy: print the actual query

I would like to point out that the solutions given above do not "just work" with non-trivial queries. One issue I came across were more complicated types, such as pgsql ARRAYs causing issues. I did find a solution that for me, did just work even with pgsql ARRAYs:

borrowed from: https://gist.github.com/gsakkis/4572159

The linked code seems to be based on an older version of SQLAlchemy. You'll get an error saying that the attribute _mapper_zero_or_none doesn't exist. Here's an updated version that will work with a newer version, you simply replace _mapper_zero_or_none with bind. Additionally, this has support for pgsql arrays:

# adapted from:
# https://gist.github.com/gsakkis/4572159
from datetime import date, timedelta
from datetime import datetime

from sqlalchemy.orm import Query


try:
    basestring
except NameError:
    basestring = str


def render_query(statement, dialect=None):
    """
    Generate an SQL expression string with bound parameters rendered inline
    for the given SQLAlchemy statement.
    WARNING: This method of escaping is insecure, incomplete, and for debugging
    purposes only. Executing SQL statements with inline-rendered user values is
    extremely insecure.
    Based on http://stackoverflow.com/questions/5631078/sqlalchemy-print-the-actual-query
    """
    if isinstance(statement, Query):
        if dialect is None:
            dialect = statement.session.bind.dialect
        statement = statement.statement
    elif dialect is None:
        dialect = statement.bind.dialect

    class LiteralCompiler(dialect.statement_compiler):

        def visit_bindparam(self, bindparam, within_columns_clause=False,
                            literal_binds=False, **kwargs):
            return self.render_literal_value(bindparam.value, bindparam.type)

        def render_array_value(self, val, item_type):
            if isinstance(val, list):
                return "{%s}" % ",".join([self.render_array_value(x, item_type) for x in val])
            return self.render_literal_value(val, item_type)

        def render_literal_value(self, value, type_):
            if isinstance(value, long):
                return str(value)
            elif isinstance(value, (basestring, date, datetime, timedelta)):
                return "'%s'" % str(value).replace("'", "''")
            elif isinstance(value, list):
                return "'{%s}'" % (",".join([self.render_array_value(x, type_.item_type) for x in value]))
            return super(LiteralCompiler, self).render_literal_value(value, type_)

    return LiteralCompiler(dialect, statement).process(statement)

Tested to two levels of nested arrays.

How to load my app from Eclipse to my Android phone instead of AVD

Yes! You can Debug Android Application While you are developing them follow these steps.. Make sure that you have PC suite of the mobile manufacturer. For Example:if you are using samsung you should have samsung kies

1.Enable USB debugging on your device:Settings > Applications > Development > USB debugging 2.Enable Unknownresources:Settings>Unknowresoures
3.Connect your device to PC
4.Select your Application Right click it: RunAS>Run configurations>Choose Device>Target Select your device Run.

You can also without using debugging cable.For that you need to install Airdroid in your device.After installing enter the link in your browser and Drag and Drop .apk file.

Happy Coding!

Binary Data in JSON String. Something better than Base64

The problem with UTF-8 is that it is not the most space efficient encoding. Also, some random binary byte sequences are invalid UTF-8 encoding. So you can't just interpret a random binary byte sequence as some UTF-8 data because it will be invalid UTF-8 encoding. The benefit of this constrain on the UTF-8 encoding is that it makes it robust and possible to locate multi byte chars start and end whatever byte we start looking at.

As a consequence, if encoding a byte value in the range [0..127] would need only one byte in UTF-8 encoding, encoding a byte value in the range [128..255] would require 2 bytes ! Worse than that. In JSON, control chars, " and \ are not allowed to appear in a string. So the binary data would require some transformation to be properly encoded.

Let see. If we assume uniformly distributed random byte values in our binary data then, on average, half of the bytes would be encoded in one bytes and the other half in two bytes. The UTF-8 encoded binary data would have 150% of the initial size.

Base64 encoding grows only to 133% of the initial size. So Base64 encoding is more efficient.

What about using another Base encoding ? In UTF-8, encoding the 128 ASCII values is the most space efficient. In 8 bits you can store 7 bits. So if we cut the binary data in 7 bit chunks to store them in each byte of an UTF-8 encoded string, the encoded data would grow only to 114% of the initial size. Better than Base64. Unfortunately we can't use this easy trick because JSON doesn't allow some ASCII chars. The 33 control characters of ASCII ( [0..31] and 127) and the " and \ must be excluded. This leaves us only 128-35 = 93 chars.

So in theory we could define a Base93 encoding which would grow the encoded size to 8/log2(93) = 8*log10(2)/log10(93) = 122%. But a Base93 encoding would not be as convenient as a Base64 encoding. Base64 requires to cut the input byte sequence in 6bit chunks for which simple bitwise operation works well. Beside 133% is not much more than 122%.

This is why I came independently to the common conclusion that Base64 is indeed the best choice to encode binary data in JSON. My answer presents a justification for it. I agree it isn't very attractive from the performance point of view, but consider also the benefit of using JSON with it's human readable string representation easy to manipulate in all programming languages.

If performance is critical than a pure binary encoding should be considered as replacement of JSON. But with JSON my conclusion is that Base64 is the best.

Moment Js UTC to Local Time

Here is what I do using Intl api:

let currentTimeZone = new Intl.DateTimeFormat().resolvedOptions().timeZone; // For example: Australia/Sydney

this will return a time zone name. Pass this parameter to the following function to get the time

let dateTime = new Date(date).toLocaleDateString('en-US',{ timeZone: currentTimeZone, hour12: true});

let time = new Date(date).toLocaleTimeString('en-US',{ timeZone: currentTimeZone, hour12: true});

you can also format the time with moment like this:

moment(new Date(`${dateTime} ${time}`)).format('YYYY-MM-DD[T]HH:mm:ss');

How to solve the “failed to lazily initialize a collection of role” Hibernate exception

I know it's an old question but I want to help. You can put the transactional annotation on the service method you need, in this case findTopicByID(id) should have

@Transactional(propagation=Propagation.REQUIRED, readOnly=true, noRollbackFor=Exception.class)

more info about this annotation can be found here

About the other solutions:

fetch = FetchType.EAGER 

is not a good practice, it should be used ONLY if necessary.

Hibernate.initialize(topics.getComments());

The hibernate initializer binds your classes to the hibernate technology. If you are aiming to be flexible is not a good way to go.

Hope it helps

Go to next item in ForEach-Object

I know this is an old post, but I wanted to add something I learned for the next folks who land here while googling.

In Powershell 5.1, you want to use continue to move onto the next item in your loop. I tested with 6 items in an array, had a foreach loop through, but put an if statement with:

foreach($i in $array){    
    write-host -fore green "hello $i"
    if($i -like "something"){
        write-host -fore red "$i is bad"
        continue
        write-host -fore red "should not see this"
    }
}

Of the 6 items, the 3rd one was something. As expected, it looped through the first 2, then the matching something gave me the red line where $i matched, I saw something is bad and then it went on to the next item in the array without saying should not see this. I tested with return and it exited the loop altogether.

Which font is used in Visual Studio Code Editor and how to change fonts?

The default fonts are different across Windows, Mac, and Linux. As of VSCode 1.15.1, the default font settings can be found in the source code:

const DEFAULT_WINDOWS_FONT_FAMILY = 'Consolas, \'Courier New\', monospace';
const DEFAULT_MAC_FONT_FAMILY = 'Menlo, Monaco, \'Courier New\', monospace';
const DEFAULT_LINUX_FONT_FAMILY = '\'Droid Sans Mono\', \'Courier New\', monospace, \'Droid Sans Fallback\'';

How to create an alert message in jsp page after submit process is complete

So let's say after getMasterData servlet will response.sendRedirect to to test.jsp.

In test.jsp

Create a javascript

<script type="text/javascript">
function alertName(){
alert("Form has been submitted");
} 
</script> 

and than at the bottom

<script type="text/javascript"> window.onload = alertName; </script>

Note:im not sure how to type the code in stackoverflow!. Edit: I just learned how to

Edit 2: TO the question:This works perfectly. Another question. How would I get rid of the initial alert when I first start up the JSP? "Form has been submitted" is present the second I execute. It shows up after the load is done to which is perfect.

To do that i would highly recommendation to use session!

So what you want to do is in your servlet:

session.setAttribute("getAlert", "Yes");//Just initialize a random variable.
response.sendRedirect(test.jsp);

than in the test.jsp

<%
session.setMaxInactiveInterval(2);
%>

 <script type="text/javascript">
var Msg ='<%=session.getAttribute("getAlert")%>';
    if (Msg != "null") {
 function alertName(){
 alert("Form has been submitted");
 } 
 }
 </script> 

and than at the bottom

<script type="text/javascript"> window.onload = alertName; </script>

So everytime you submit that form a session will be pass on! If session is not null the function will run!

Angular 2: import external js file into component

Here is a simple way i did it in my project.

lets say you need to use clipboard.min.js and for the sake of the example lets say that inside clipboard.min.js there is a function that called test2().

in order to use test2() function you need:

  1. make a reference to the .js file inside you index.html.
  2. import clipboard.min.js to your component.
  3. declare a variable that will use you to call the function.

here are only the relevant parts from my project (see the comments):

index.html:

<!DOCTYPE html>
<html>
<head>
    <title>Angular QuickStart</title>
    <base href="/src/">
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="styles.css">

    <!-- Polyfill(s) for older browsers -->
    <script src="/node_modules/core-js/client/shim.min.js"></script>


    <script src="/node_modules/zone.js/dist/zone.js"></script>
    <script src="/node_modules/systemjs/dist/system.src.js"></script>

    <script src="systemjs.config.js"></script>
    <script>
        System.import('main.js').catch(function (err) { console.error(err); });
    </script>

    <!-- ************ HERE IS THE REFERENCE TO clipboard.min.js -->
    <script src="app/txtzone/clipboard.min.js"></script>
</head>

<body>
    <my-app>Loading AppComponent content here ...</my-app>
</body>
</html>

app.component.ts:

import '../txtzone/clipboard.min.js';
declare var test2: any; // variable as the name of the function inside clipboard.min.js

@Component({
    selector: 'txt-zone',
    templateUrl: 'app/txtzone/Txtzone.component.html',
    styleUrls: ['app/txtzone/TxtZone.css'],
})



export class TxtZoneComponent implements AfterViewInit {

    // call test2
    callTest2()
    {   
        new test2(); // the javascript function will execute
    }

}

Apache and Node.js on the Same Server

I was looking for the same information. Finally found the answer from the link on the answer above by @Straseus

http://arguments.callee.info/2010/04/20/running-apache-and-node-js-together/

Here is the final solution to run apache website on port 80, node js service on port 8080 and use .htaccess RewriteRule

In the DocumentRoot of the apache website, add the following:

Options +FollowSymLinks -MultiViews

<IfModule mod_rewrite.c>

RewriteEngine on

# Simple URL redirect:
RewriteRule ^test.html$ http://arguments.callee.info:8000/test/ [P]

# More complicated (the user sees only "benchmark.html" in their address bar)
RewriteRule ^benchmark.html$ http://arguments.callee.info:8000/node?action=benchmark [P]

# Redirect a whole subdirectory:
RewriteRule ^node/(.*) http://arguments.callee.info:8000/$1 [P]

For the directory level redirect, the link above suggested (.+) rule, which requires one or more character after the 'node/'. I had to convert it to (.*) which is zero or more for my stuff to work.

Thanks a lot for the link @Straseus

How can I get the external SD card path for Android 4.0+?

that's not true. /mnt/sdcard/external_sd can exist even if the SD card is not mounted. your application will crash when you try to write to /mnt/sdcard/external_sd when it's not mounted.

you need to check if the SD card is mounted first using:

boolean isSDPresent = Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED);

php - add + 7 days to date format mm dd, YYYY

Another more recent and object style way to do it :

$date = new DateTime('now');
$date->add(new DateInterval('P7D'));

php doc of datetime add

Insert multiple rows with one query MySQL

Here are a few ways to do it

INSERT INTO pxlot (realname,email,address,phone,status,regtime,ip) 
select '$realname','$email','$address','$phone','0','$dateTime','$ip' 
from SOMETABLEWITHTONSOFROWS LIMIT 3;

or

INSERT INTO pxlot (realname,email,address,phone,status,regtime,ip) 
select '$realname','$email','$address','$phone','0','$dateTime','$ip'
union all select '$realname','$email','$address','$phone','0','$dateTime','$ip'
union all select '$realname','$email','$address','$phone','0','$dateTime','$ip'

or

INSERT INTO pxlot (realname,email,address,phone,status,regtime,ip) 
values ('$realname','$email','$address','$phone','0','$dateTime','$ip')
,('$realname','$email','$address','$phone','0','$dateTime','$ip')
,('$realname','$email','$address','$phone','0','$dateTime','$ip')

How do I vertically center an H1 in a div?

Just use padding top and bottom, it will automatically center the content vertically.

calling a function from class in python - different way

class MathsOperations:
    def __init__ (self, x, y):
        self.a = x
        self.b = y
    def testAddition (self):
        return (self.a + self.b)

    def testMultiplication (self):
        return (self.a * self.b)

then

temp = MathsOperations()
print(temp.testAddition())

Django: Display Choice Value

For every field that has choices set, the object will have a get_FOO_display() method, where FOO is the name of the field. This method returns the “human-readable” value of the field.

In Views

person = Person.objects.filter(to_be_listed=True)
context['gender'] = person.get_gender_display()

In Template

{{ person.get_gender_display }}

Documentation of get_FOO_display()

Padding In bootstrap

I have not used Bootstrap but I worked on Zurb Foundation. On that I used to add space like this.

<div id="main" class="container" role="main">
    <div class="row">

        <div class="span5 offset1">
            <h2>Welcome</h2>
            <p>Hello and welcome to my website.</p>
        </div>
        <div class="span6">
            Image Here (TODO)
        </div>
    </div>

Visit this link: http://getbootstrap.com/2.3.2/scaffolding.html and read the section: Offsetting columns.

I think I know what you are doing wrong. If you are applying padding to the span6 like this:

<div class="span6" style="padding-left:5px;">
    <h2>Welcome</h2>
    <p>Hello and welcome to my website.</p>
</div>

It is wrong. What you have to do is add padding to the elements inside:

<div class="span6">
    <h2 style="padding-left:5px;">Welcome</h2>
    <p  style="padding-left:5px;">Hello and welcome to my website.</p>
</div>

How to deserialize JS date using Jackson?

I found a work around but with this I'll need to annotate each date's setter throughout the project. Is there a way in which I can specify the format while creating the ObjectMapper?

Here's what I did:

public class CustomJsonDateDeserializer extends JsonDeserializer<Date>
{
    @Override
    public Date deserialize(JsonParser jsonParser,
            DeserializationContext deserializationContext) throws IOException, JsonProcessingException {

        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
        String date = jsonParser.getText();
        try {
            return format.parse(date);
        } catch (ParseException e) {
            throw new RuntimeException(e);
        }

    }

}

And annotated each Date field's setter method with this:

@JsonDeserialize(using = CustomJsonDateDeserializer.class)

How to ssh from within a bash script?

  1. If you want the password prompt to go away then use key based authentication (described here).

  2. To run commands remotely over ssh you have to give them as an argument to ssh, like the following:

root@host:~ # ssh root@www 'ps -ef | grep apache | grep -v grep | wc -l'

How do I cancel a build that is in progress in Visual Studio?

The "pause" command was a function button underneath my right shift key, so the below combination of keys did the trick for me.

Ctrl + Fn + Shift

Is it possible to use global variables in Rust?

Heap allocations are possible for static variables if you use the lazy_static macro as seen in the docs

Using this macro, it is possible to have statics that require code to be executed at runtime in order to be initialized. This includes anything requiring heap allocations, like vectors or hash maps, as well as anything that requires function calls to be computed.

// Declares a lazily evaluated constant HashMap. The HashMap will be evaluated once and
// stored behind a global static reference.

use lazy_static::lazy_static;
use std::collections::HashMap;

lazy_static! {
    static ref PRIVILEGES: HashMap<&'static str, Vec<&'static str>> = {
        let mut map = HashMap::new();
        map.insert("James", vec!["user", "admin"]);
        map.insert("Jim", vec!["user"]);
        map
    };
}

fn show_access(name: &str) {
    let access = PRIVILEGES.get(name);
    println!("{}: {:?}", name, access);
}

fn main() {
    let access = PRIVILEGES.get("James");
    println!("James: {:?}", access);

    show_access("Jim");
}

sqlite3.OperationalError: unable to open database file

Django NewbieMistakes

PROBLEM You're using SQLite3, your DATABASE_NAME is set to the database file's full path, the database file is writeable by Apache, but you still get the above error.

SOLUTION Make sure Apache can also write to the parent directory of the database. SQLite needs to be able to write to this directory.

Make sure each folder of your database file's full path does not start with number, eg. /www/4myweb/db (observed on Windows 2000).

If DATABASE_NAME is set to something like '/Users/yourname/Sites/mydjangoproject/db/db', make sure you've created the 'db' directory first.

Make sure your /tmp directory is world-writable (an unlikely cause as other thing on your system will also not work). ls /tmp -ald should produce drwxrwxrwt ....

Make sure the path to the database specified in settings.py is a full path.

Also make sure the file is present where you expect it to be.

How to git clone a specific tag

git clone --depth 1 --branch <tag_name> <repo_url>

Example

git clone --depth 1 --branch 0.37.2 https://github.com/apache/incubator-superset.git

<tag_name> : 0.37.2

<repo_url> : https://github.com/apache/incubator-superset.git

How to use subList()

You could use streams in Java 8. To always get 10 entries at the most, you could do:

dataList.stream().skip(5).limit(10).collect(Collectors.toList());
dataList.stream().skip(30).limit(10).collect(Collectors.toList());

Java: getMinutes and getHours

One more way of getting minutes and hours is by using SimpleDateFormat.

SimpleDateFormat formatMinutes = new SimpleDateFormat("mm")
String getMinutes = formatMinutes.format(new Date())

SimpleDateFormat formatHours = new SimpleDateFormat("HH")
String getHours = formatHours.format(new Date())

How can I delete using INNER JOIN with SQL Server?

This version should work:

DELETE WorkRecord2
FROM WorkRecord2 
INNER JOIN Employee ON EmployeeRun=EmployeeNo
Where Company = '1' AND Date = '2013-05-06'

PermissionError: [Errno 13] in python

When doing;

a_file = open('E:\Python Win7-64-AMD 3.3\Test', encoding='utf-8')

...you're trying to open a directory as a file, which may (and on most non UNIX file systems will) fail.

Your other example though;

a_file = open('E:\Python Win7-64-AMD 3.3\Test\a.txt', encoding='utf-8')

should work well if you just have the permission on a.txt. You may want to use a raw (r-prefixed) string though, to make sure your path does not contain any escape characters like \n that will be translated to special characters.

a_file = open(r'E:\Python Win7-64-AMD 3.3\Test\a.txt', encoding='utf-8')

How to start Spyder IDE on Windows

Install Ananconda packages and within that launch spyder 3 for first time. Then by second time you just click on spyder under anaconda in all programs.

Rails create or update magic?

Rails 6

Rails 6 added an upsert and upsert_all methods that deliver this functionality.

Model.upsert(column_name: value)

[upsert] It does not instantiate any models nor does it trigger Active Record callbacks or validations.

Rails 5, 4, and 3

Not if you are looking for an "upsert" (where the database executes an update or an insert statement in the same operation) type of statement. Out of the box, Rails and ActiveRecord have no such feature. You can use the upsert gem, however.

Otherwise, you can use: find_or_initialize_by or find_or_create_by, which offer similar functionality, albeit at the cost of an additional database hit, which, in most cases, is hardly an issue at all. So unless you have serious performance concerns, I would not use the gem.

For example, if no user is found with the name "Roger", a new user instance is instantiated with its name set to "Roger".

user = User.where(name: "Roger").first_or_initialize
user.email = "[email protected]"
user.save

Alternatively, you can use find_or_initialize_by.

user = User.find_or_initialize_by(name: "Roger")

In Rails 3.

user = User.find_or_initialize_by_name("Roger")
user.email = "[email protected]"
user.save

You can use a block, but the block only runs if the record is new.

User.where(name: "Roger").first_or_initialize do |user|
  # this won't run if a user with name "Roger" is found
  user.save 
end

User.find_or_initialize_by(name: "Roger") do |user|
  # this also won't run if a user with name "Roger" is found
  user.save
end

If you want to use a block regardless of the record's persistence, use tap on the result:

User.where(name: "Roger").first_or_initialize.tap do |user|
  user.email = "[email protected]"
  user.save
end

Add 2 hours to current time in MySQL?

SELECT * FROM courses WHERE (NOW() + INTERVAL 2 HOUR) > start_time

Android Studio Could not initialize class org.codehaus.groovy.runtime.InvokerHelper

When you upgrade to the latest version of the gradle in the gradle-wrapper.properties file i.e. distributionUrl=https\://services.gradle.org/distributions/gradle-6.6.1-bin.zip please do not forget to change the gradle version in the build.gradle file as well

wrapper {
    gradleVersion = '6.6.1'
}

How to use refs in React with Typescript

class SelfFocusingInput extends React.Component<{ value: string, onChange: (value: string) => any }, {}>{
    ctrls: {
        input?: HTMLInputElement;
    } = {};
    render() {
        return (
            <input
                ref={(input) => this.ctrls.input = input}
                value={this.props.value}
                onChange={(e) => { this.props.onChange(this.ctrls.input.value) } }
                />
        );
    }
    componentDidMount() {
        this.ctrls.input.focus();
    }
}

put them in an object

Encrypt Password in Configuration Files?

Depending on how secure you need the configuration files or how reliable your application is, http://activemq.apache.org/encrypted-passwords.html may be a good solution for you.

If you are not too afraid of the password being decrypted and it can be really simple to configure using a bean to store the password key. However, if you need more security you can set an environment variable with the secret and remove it after launch. With this you have to worry about the application / server going down and not application not automatically relaunching.

CSS align one item right with flexbox

To align some elements (headerElement) in the center and the last element to the right (headerEnd).

.headerElement {
    margin-right: 5%;
    margin-left: 5%;
}
.headerEnd{
    margin-left: auto;
}

How to create table using select query in SQL Server?

An example statement that uses a sub-select :

select * into MyNewTable
from
(
select 
  * 
from 
[SomeOtherTablename]
where 
  EventStartDatetime >= '01/JAN/2018' 
)
) mysourcedata
;

note that the sub query must be given a name .. any name .. e.g. above example gives the subquery a name of mysourcedata. Without this a syntax error is issued in SQL*server 2012.

The database should reply with a message like: (9999 row(s) affected)

What is a predicate in c#?

The following code can help you to understand some real world use of predicates (Combined with named iterators).

namespace Predicate
{
    class Person
    {
        public int Age { get; set; }
    }
    class Program
    {
        static void Main(string[] args)
        {
            foreach (Person person in OlderThan(18))
            {
                Console.WriteLine(person.Age);
            }
        }

        static IEnumerable<Person> OlderThan(int age)
        {
            Predicate<Person> isOld = x => x.Age > age;
            Person[] persons = { new Person { Age = 10 }, new Person { Age = 20 }, new Person { Age = 19 } };

            foreach (Person person in persons)
                if (isOld(person)) yield return person;
        }
    }
}

How can I stop the browser back button using JavaScript?

In my case this was a shopping order. So I disabled the button. When the user clicked back, the button was disabled still. When they clicked back one more time, and then clicked a page button to go forward. I knew their order was submitted and skipped to another page.

In the case when the page actually refreshed which would make the button (theoretically), available; I was then able to react in the page load that the order was already submitted and redirected then too.

$(this).serialize() -- How to add a value?

We can do like:

data = $form.serialize() + "&foo=bar";

For example:

var userData = localStorage.getItem("userFormSerializeData");
var userId = localStorage.getItem("userId");

$.ajax({
    type: "POST",
    url: postUrl,
    data: $(form).serialize() + "&" + userData + "&userId=" + userId,
    dataType: 'json',
    success: function (response) {
        //do something
    }
});

mysql after insert trigger which updates another table's column

With your requirements you don't need BEGIN END and IF with unnecessary SELECT in your trigger. So you can simplify it to this

CREATE TRIGGER occupy_trig AFTER INSERT ON occupiedroom 
FOR EACH ROW
  UPDATE BookingRequest
     SET status = 1
   WHERE idRequest = NEW.idRequest;

Web scraping with Python

Make your life easier by using CSS Selectors

I know I have come late to party but I have a nice suggestion for you.

Using BeautifulSoup is already been suggested I would rather prefer using CSS Selectors to scrape data inside HTML

import urllib2
from bs4 import BeautifulSoup

main_url = "http://www.example.com"

main_page_html  = tryAgain(main_url)
main_page_soup = BeautifulSoup(main_page_html)

# Scrape all TDs from TRs inside Table
for tr in main_page_soup.select("table.class_of_table"):
   for td in tr.select("td#id"):
       print(td.text)
       # For acnhors inside TD
       print(td.select("a")[0].text)
       # Value of Href attribute
       print(td.select("a")[0]["href"])

# This is method that scrape URL and if it doesnt get scraped, waits for 20 seconds and then tries again. (I use it because my internet connection sometimes get disconnects)
def tryAgain(passed_url):
    try:
        page  = requests.get(passed_url,headers = random.choice(header), timeout = timeout_time).text
        return page
    except Exception:
        while 1:
            print("Trying again the URL:")
            print(passed_url)
            try:
                page  = requests.get(passed_url,headers = random.choice(header), timeout = timeout_time).text
                print("-------------------------------------")
                print("---- URL was successfully scraped ---")
                print("-------------------------------------")
                return page
            except Exception:
                time.sleep(20)
                continue 

TypeError: int() argument must be a string, a bytes-like object or a number, not 'list'

What the error is telling, is that you can't convert an entire list into an integer. You could get an index from the list and convert that into an integer:

x = ["0", "1", "2"] 
y = int(x[0]) #accessing the zeroth element

If you're trying to convert a whole list into an integer, you are going to have to convert the list into a string first:

x = ["0", "1", "2"]
y = ''.join(x) # converting list into string
z = int(y)

If your list elements are not strings, you'll have to convert them to strings before using str.join:

x = [0, 1, 2]
y = ''.join(map(str, x))
z = int(y)

Also, as stated above, make sure that you're not returning a nested list.

How do I get the full path to a Perl script that is executing?

On *nix, you likely have the "whereis" command, which searches your $PATH looking for a binary with a given name. If $0 doesn't contain the full path name, running whereis $scriptname and saving the result into a variable should tell you where the script is located.

How can I switch themes in Visual Studio 2012

Try the steps in here: If you don't have Visual Studio 2010 installed, some icons are provided.

http://supunlivera.blogspot.com/2012/09/visual-studio-2012-theme-change-get-vs.html

R numbers from 1 to 100

If you need the construct for a quick example to play with, use the : operator.

But if you are creating a vector/range of numbers dynamically, then use seq() instead.

Let's say you are creating the vector/range of numbers from a to b with a:b, and you expect it to be an increasing series. Then, if b is evaluated to be less than a, you will get a decreasing sequence but you will never be notified about it, and your program will continue to execute with the wrong kind of input.

In this case, if you use seq(), you can set the sign of the by argument to match the direction of your sequence, and an error will be raised if they do not match. For example,

seq(a, b, -1)

will raise an error for a=2, b=6, because the coder expected a decreasing sequence.

Getting Access Denied when calling the PutObject operation with bucket-level permission

In case this help out anyone else, in my case, I was using a CMK (it worked fine using the default aws/s3 key)

I had to go into my encryption key definition in IAM and add the programmatic user logged into boto3 to the list of users that "can use this key to encrypt and decrypt data from within applications and when using AWS services integrated with KMS.".

How to revert a "git rm -r ."?

If you end up with none of the above working, you might be able to retrieve data using the suggestion from here: http://www.spinics.net/lists/git/msg62499.html

git prune -n
git cat-file -p <blob #>

String to HashMap JAVA

Assuming no key contains either ',' or ':':

Map<String, Integer> map = new HashMap<String, Integer>();
for(final String entry : s.split(",")) {
    final String[] parts = entry.split(":");
    assert(parts.length == 2) : "Invalid entry: " + entry;
    map.put(parts[0], new Integer(parts[1]));
}

Using number as "index" (JSON)

JSON regulates key type to be string. The purpose is to support the dot notation to access the members of the object.

For example, person = {"height":170, "weight":60, "age":32}. You can access members by person.height, person.weight, etc. If JSON supports value keys, then it would look like person.0, person.1, person.2.

How to make a simple collection view with Swift

This project has been tested with Xcode 10 and Swift 4.2.

Create a new project

It can be just a Single View App.

Add the code

Create a new Cocoa Touch Class file (File > New > File... > iOS > Cocoa Touch Class). Name it MyCollectionViewCell. This class will hold the outlets for the views that you add to your cell in the storyboard.

import UIKit
class MyCollectionViewCell: UICollectionViewCell {
    
    @IBOutlet weak var myLabel: UILabel!
}

We will connect this outlet later.

Open ViewController.swift and make sure you have the following content:

import UIKit
class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate {
    
    let reuseIdentifier = "cell" // also enter this string as the cell identifier in the storyboard
    var items = ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", "26", "27", "28", "29", "30", "31", "32", "33", "34", "35", "36", "37", "38", "39", "40", "41", "42", "43", "44", "45", "46", "47", "48"]
    
    
    // MARK: - UICollectionViewDataSource protocol
    
    // tell the collection view how many cells to make
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return self.items.count
    }
    
    // make a cell for each cell index path
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
        
        // get a reference to our storyboard cell
        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuseIdentifier, for: indexPath as IndexPath) as! MyCollectionViewCell
        
        // Use the outlet in our custom class to get a reference to the UILabel in the cell
        cell.myLabel.text = self.items[indexPath.row] // The row value is the same as the index of the desired text within the array.
        cell.backgroundColor = UIColor.cyan // make cell more visible in our example project
        
        return cell
    }
    
    // MARK: - UICollectionViewDelegate protocol
    
    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        // handle tap events
        print("You selected cell #\(indexPath.item)!")
    }
}

Notes

  • UICollectionViewDataSource and UICollectionViewDelegate are the protocols that the collection view follows. You could also add the UICollectionViewFlowLayout protocol to change the size of the views programmatically, but it isn't necessary.
  • We are just putting simple strings in our grid, but you could certainly do images later.

Set up the storyboard

Drag a Collection View to the View Controller in your storyboard. You can add constraints to make it fill the parent view if you like.

enter image description here

Make sure that your defaults in the Attribute Inspector are also

  • Items: 1
  • Layout: Flow

The little box in the top left of the Collection View is a Collection View Cell. We will use it as our prototype cell. Drag a Label into the cell and center it. You can resize the cell borders and add constraints to center the Label if you like.

enter image description here

Write "cell" (without quotes) in the Identifier box of the Attributes Inspector for the Collection View Cell. Note that this is the same value as let reuseIdentifier = "cell" in ViewController.swift.

enter image description here

And in the Identity Inspector for the cell, set the class name to MyCollectionViewCell, our custom class that we made.

enter image description here

Hook up the outlets

  • Hook the Label in the collection cell to myLabel in the MyCollectionViewCell class. (You can Control-drag.)
  • Hook the Collection View delegate and dataSource to the View Controller. (Right click Collection View in the Document Outline. Then click and drag the plus arrow up to the View Controller.)

enter image description here

Finished

Here is what it looks like after adding constraints to center the Label in the cell and pinning the Collection View to the walls of the parent.

enter image description here

Making Improvements

The example above works but it is rather ugly. Here are a few things you can play with:

Background color

In the Interface Builder, go to your Collection View > Attributes Inspector > View > Background.

Cell spacing

Changing the minimum spacing between cells to a smaller value makes it look better. In the Interface Builder, go to your Collection View > Size Inspector > Min Spacing and make the values smaller. "For cells" is the horizontal distance and "For lines" is the vertical distance.

Cell shape

If you want rounded corners, a border, and the like, you can play around with the cell layer. Here is some sample code. You would put it directly after cell.backgroundColor = UIColor.cyan in code above.

cell.layer.borderColor = UIColor.black.cgColor
cell.layer.borderWidth = 1
cell.layer.cornerRadius = 8

See this answer for other things you can do with the layer (shadow, for example).

Changing the color when tapped

It makes for a better user experience when the cells respond visually to taps. One way to achieve this is to change the background color while the cell is being touched. To do that, add the following two methods to your ViewController class:

// change background color when user touches cell
func collectionView(_ collectionView: UICollectionView, didHighlightItemAt indexPath: IndexPath) {
    let cell = collectionView.cellForItem(at: indexPath)
    cell?.backgroundColor = UIColor.red
}

// change background color back when user releases touch
func collectionView(_ collectionView: UICollectionView, didUnhighlightItemAt indexPath: IndexPath) {
    let cell = collectionView.cellForItem(at: indexPath)
    cell?.backgroundColor = UIColor.cyan
}

Here is the updated look:

enter image description here

Further study

UITableView version of this Q&A

How do I connect to a Websphere Datasource with a given JNDI name?

Find below code to get database connection from your web app server. Just create datasource in app server and use following code to get connection :

// To Get DataSource
Context ctx = new InitialContext();
DataSource ds = (DataSource)ctx.lookup("jdbc/abcd");
// Get Connection and Statement
Connection c = ds.getConnection();
stmt = c.createStatement();

Import naming and sql classes. No need to add any xml file or to edit anything in project.
That's it..

How to convert strings into integers in Python?

Yet another functional solution for Python 2:

from functools import partial

map(partial(map, int), T1)

Python 3 will be a little bit messy though:

list(map(list, map(partial(map, int), T1)))

we can fix this with a wrapper

def oldmap(f, iterable):
    return list(map(f, iterable))

oldmap(partial(oldmap, int), T1)

Latex - Change margins of only a few pages

A slight modification of this to change the \voffset works for me:

\newenvironment{changemargin}[1]{
  \begin{list}{}{
    \setlength{\voffset}{#1}
  }
  \item[]}{\end{list}}

And then put your figures in a \begin{changemargin}{-1cm}...\end{changemargin} environment.

How can I read the contents of an URL with Python?

We can read website html content as below :

from urllib.request import urlopen
response = urlopen('http://google.com/')
html = response.read()
print(html)

How to check if JSON return is empty with jquery

if (!json[0]) alert("JSON empty");

Angular 2 - NgFor using numbers instead collections

<div *ngFor="let number of [].constructor(myCollection)">
    <div>
        Hello World
    </div>
</div>

This is a nice and quick way to repeat for the amount of times in myCollection.

So if myCollection was 5, Hello World would be repeated 5 times.

Pip - Fatal error in launcher: Unable to create process using '"'

I met the the same error as you.that is because i had transplanted my python file from D disk to e disk. after that ,when I inputed python ,it worked. pip and other exe file which has the same path as pip ,it did not work. when "python -m pip install --upgrade pip" order was inputed,pip order worked,but other exe file which has the same path as pip did not work,so i think it is not the best way. at last I unistalled my python,and re-install it.everything is okay.maybe it is not the best way for all of you ,but it is for me.

How do I copy directories recursively with gulp?

Turns out that to copy a complete directory structure gulp needs to be provided with a base for your gulp.src() method.

So gulp.src( [ files ], { "base" : "." }) can be used in the structure above to copy all the directories recursively.

If, like me, you may forget this then try:

gulp.copy=function(src,dest){
    return gulp.src(src, {base:"."})
        .pipe(gulp.dest(dest));
};

Send message to specific client with socket.io and node.js

Well you have to grab the client for that (surprise), you can either go the simple way:

var io = io.listen(server);
io.clients[sessionID].send()

Which may break, I doubt it, but it's always a possibility that io.clients might get changed, so use the above with caution

Or you keep track of the clients yourself, therefore you add them to your own clients object in the connection listener and remove them in the disconnect listener.

I would use the latter one, since depending on your application you might want to have more state on the clients anyway, so something like clients[id] = {conn: clientConnect, data: {...}} might do the job.

What is the difference between Scope_Identity(), Identity(), @@Identity, and Ident_Current()?

Good question.

  • @@IDENTITY: returns the last identity value generated on your SQL connection (SPID). Most of the time it will be what you want, but sometimes it isn't (like when a trigger is fired in response to an INSERT, and the trigger executes another INSERT statement).

  • SCOPE_IDENTITY(): returns the last identity value generated in the current scope (i.e. stored procedure, trigger, function, etc).

  • IDENT_CURRENT(): returns the last identity value for a specific table. Don't use this to get the identity value from an INSERT, it's subject to race conditions (i.e. multiple connections inserting rows on the same table).

  • IDENTITY(): used when declaring a column in a table as an identity column.

For more reference, see: http://msdn.microsoft.com/en-us/library/ms187342.aspx.

To summarize: if you are inserting rows, and you want to know the value of the identity column for the row you just inserted, always use SCOPE_IDENTITY().

Getting absolute URLs using ASP.NET Core

This is a variation of the anwser by Muhammad Rehan Saeed, with the class getting parasitically attached to the existing .net core MVC class of the same name, so that everything just works.

namespace Microsoft.AspNetCore.Mvc
{
    /// <summary>
    /// <see cref="IUrlHelper"/> extension methods.
    /// </summary>
    public static partial class UrlHelperExtensions
    {
        /// <summary>
        /// Generates a fully qualified URL to an action method by using the specified action name, controller name and
        /// route values.
        /// </summary>
        /// <param name="url">The URL helper.</param>
        /// <param name="actionName">The name of the action method.</param>
        /// <param name="controllerName">The name of the controller.</param>
        /// <param name="routeValues">The route values.</param>
        /// <returns>The absolute URL.</returns>
        public static string AbsoluteAction(
            this IUrlHelper url,
            string actionName,
            string controllerName,
            object routeValues = null)
        {
            return url.Action(actionName, controllerName, routeValues, url.ActionContext.HttpContext.Request.Scheme);
        }

        /// <summary>
        /// Generates a fully qualified URL to the specified content by using the specified content path. Converts a
        /// virtual (relative) path to an application absolute path.
        /// </summary>
        /// <param name="url">The URL helper.</param>
        /// <param name="contentPath">The content path.</param>
        /// <returns>The absolute URL.</returns>
        public static string AbsoluteContent(
            this IUrlHelper url,
            string contentPath)
        {
            HttpRequest request = url.ActionContext.HttpContext.Request;
            return new Uri(new Uri(request.Scheme + "://" + request.Host.Value), url.Content(contentPath)).ToString();
        }

        /// <summary>
        /// Generates a fully qualified URL to the specified route by using the route name and route values.
        /// </summary>
        /// <param name="url">The URL helper.</param>
        /// <param name="routeName">Name of the route.</param>
        /// <param name="routeValues">The route values.</param>
        /// <returns>The absolute URL.</returns>
        public static string AbsoluteRouteUrl(
            this IUrlHelper url,
            string routeName,
            object routeValues = null)
        {
            return url.RouteUrl(routeName, routeValues, url.ActionContext.HttpContext.Request.Scheme);
        }
    }
}

Properties private set;

You can let the user set a read-only property by providing it through the constructor:

public class Person
{
    public Person(int id)
    {
        this.Id = id;
    }

    public string Name { get;  set; }
    public int Id { get; private set; }
    public int Age { get; set; }
}

Load More Posts Ajax Button in WordPress

UPDATE 24.04.2016.

I've created tutorial on my page https://madebydenis.com/ajax-load-posts-on-wordpress/ about implementing this on Twenty Sixteen theme, so feel free to check it out :)

EDIT

I've tested this on Twenty Fifteen and it's working, so it should be working for you.

In index.php (assuming that you want to show the posts on the main page, but this should work even if you put it in a page template) I put:

    <div id="ajax-posts" class="row">
        <?php
            $postsPerPage = 3;
            $args = array(
                    'post_type' => 'post',
                    'posts_per_page' => $postsPerPage,
                    'cat' => 8
            );

            $loop = new WP_Query($args);

            while ($loop->have_posts()) : $loop->the_post();
        ?>

         <div class="small-12 large-4 columns">
                <h1><?php the_title(); ?></h1>
                <p><?php the_content(); ?></p>
         </div>

         <?php
                endwhile;
        wp_reset_postdata();
         ?>
    </div>
    <div id="more_posts">Load More</div>

This will output 3 posts from category 8 (I had posts in that category, so I used it, you can use whatever you want to). You can even query the category you're in with

$cat_id = get_query_var('cat');

This will give you the category id to use in your query. You could put this in your loader (load more div), and pull with jQuery like

<div id="more_posts" data-category="<?php echo $cat_id; ?>">>Load More</div>

And pull the category with

var cat = $('#more_posts').data('category');

But for now, you can leave this out.

Next in functions.php I added

wp_localize_script( 'twentyfifteen-script', 'ajax_posts', array(
    'ajaxurl' => admin_url( 'admin-ajax.php' ),
    'noposts' => __('No older posts found', 'twentyfifteen'),
));

Right after the existing wp_localize_script. This will load WordPress own admin-ajax.php so that we can use it when we call it in our ajax call.

At the end of the functions.php file I added the function that will load your posts:

function more_post_ajax(){

    $ppp = (isset($_POST["ppp"])) ? $_POST["ppp"] : 3;
    $page = (isset($_POST['pageNumber'])) ? $_POST['pageNumber'] : 0;

    header("Content-Type: text/html");

    $args = array(
        'suppress_filters' => true,
        'post_type' => 'post',
        'posts_per_page' => $ppp,
        'cat' => 8,
        'paged'    => $page,
    );

    $loop = new WP_Query($args);

    $out = '';

    if ($loop -> have_posts()) :  while ($loop -> have_posts()) : $loop -> the_post();
        $out .= '<div class="small-12 large-4 columns">
                <h1>'.get_the_title().'</h1>
                <p>'.get_the_content().'</p>
         </div>';

    endwhile;
    endif;
    wp_reset_postdata();
    die($out);
}

add_action('wp_ajax_nopriv_more_post_ajax', 'more_post_ajax');
add_action('wp_ajax_more_post_ajax', 'more_post_ajax');

Here I've added paged key in the array, so that the loop can keep track on what page you are when you load your posts.

If you've added your category in the loader, you'd add:

$cat = (isset($_POST['cat'])) ? $_POST['cat'] : '';

And instead of 8, you'd put $cat. This will be in the $_POST array, and you'll be able to use it in ajax.

Last part is the ajax itself. In functions.js I put inside the $(document).ready(); enviroment

var ppp = 3; // Post per page
var cat = 8;
var pageNumber = 1;


function load_posts(){
    pageNumber++;
    var str = '&cat=' + cat + '&pageNumber=' + pageNumber + '&ppp=' + ppp + '&action=more_post_ajax';
    $.ajax({
        type: "POST",
        dataType: "html",
        url: ajax_posts.ajaxurl,
        data: str,
        success: function(data){
            var $data = $(data);
            if($data.length){
                $("#ajax-posts").append($data);
                $("#more_posts").attr("disabled",false);
            } else{
                $("#more_posts").attr("disabled",true);
            }
        },
        error : function(jqXHR, textStatus, errorThrown) {
            $loader.html(jqXHR + " :: " + textStatus + " :: " + errorThrown);
        }

    });
    return false;
}

$("#more_posts").on("click",function(){ // When btn is pressed.
    $("#more_posts").attr("disabled",true); // Disable the button, temp.
    load_posts();
});

Saved it, tested it, and it works :)

Images as proof (don't mind the shoddy styling, it was done quickly). Also post content is gibberish xD

enter image description here

enter image description here

enter image description here

UPDATE

For 'infinite load' instead on click event on the button (just make it invisible, with visibility: hidden;) you can try with

$(window).on('scroll', function () {
    if ($(window).scrollTop() + $(window).height()  >= $(document).height() - 100) {
        load_posts();
    }
});

This should run the load_posts() function when you're 100px from the bottom of the page. In the case of the tutorial on my site you can add a check to see if the posts are loading (to prevent firing of the ajax twice), and you can fire it when the scroll reaches the top of the footer

$(window).on('scroll', function(){
    if($('body').scrollTop()+$(window).height() > $('footer').offset().top){
        if(!($loader.hasClass('post_loading_loader') || $loader.hasClass('post_no_more_posts'))){
                load_posts();
        }
    }
});

Now the only drawback in these cases is that you could never scroll to the value of $(document).height() - 100 or $('footer').offset().top for some reason. If that should happen, just increase the number where the scroll goes to.

You can easily check it by putting console.logs in your code and see in the inspector what they throw out

$(window).on('scroll', function () {
    console.log($(window).scrollTop() + $(window).height());
    console.log($(document).height() - 100);
    if ($(window).scrollTop() + $(window).height()  >= $(document).height() - 100) {
        load_posts();
    }
});

And just adjust accordingly ;)

Hope this helps :) If you have any questions just ask.

Merge, update, and pull Git branches without using checkouts

Another, admittedly pretty brute way is to just re-create the branch:

git fetch remote
git branch -f localbranch remote/remotebranch

This throws away the local outdated branch and re-creates one with the same name, so use with care ...

How to set a JVM TimeZone Properly

If you are using Maven:

mvn -Dexec.args="-Duser.timezone=Europe/Sofia ....."

Check if EditText is empty.

EditText txtUserID = (EditText) findViewById(R.id.txtUserID);

String UserID = txtUserID.getText().toString();

if (UserID.equals("")) 

{
    Log.d("value","null");
}

You will see the message in LogCat....

How to delete files/subfolders in a specific directory at the command prompt in Windows

I tried several of these approaches, but none worked properly.

I found this two-step approach on the site Windows Command Line:

forfiles /P %pathtofolder% /M * /C "cmd /c if @isdir==FALSE del @file"

forfiles /P %pathtofolder%  /M * /C "cmd /c if @isdir==TRUE rmdir /S /Q @file"

It worked exactly as I needed and as specified by the OP.

Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/JDBC_DBO]]

server.xml is created when you publish a project.Now If you add more dependency later then server.xml will not be able to catch it until and unless it is refreshed again. Sometimes you need to rebuild context/config file also. First you try to clean the work directory.If it doesn't work then delete server and Server folder,then reconfigure those two.

Hiding user input on terminal in Linux script

Get Username and password

Make it more clear to read but put it on a better position over the screen

#!/bin/bash
clear
echo 
echo 
echo
counter=0
unset username
prompt="  Enter Username:"
while IFS= read -p "$prompt" -r -s -n 1 char
do
    if [[ $char == $'\0' ]]; then
        break
    elif [ $char == $'\x08' ] && [ $counter -gt 0 ]; then
        prompt=$'\b \b'
        username="${username%?}"
        counter=$((counter-1))
    elif [ $char == $'\x08' ] && [ $counter -lt 1 ]; then
        prompt=''
        continue
    else
        counter=$((counter+1))
        prompt="$char"
        username+="$char"
    fi
done
echo
unset password
prompt="  Enter Password:"
while IFS= read -p "$prompt" -r -s -n 1 char
do
    if [[ $char == $'\0' ]]; then
        break
    elif [ $char == $'\x08' ] && [ $counter -gt 0 ]; then
        prompt=$'\b \b'
        password="${password%?}"
        counter=$((counter-1))
    elif [ $char == $'\x08' ] && [ $counter -lt 1 ]; then
        echo
        prompt="  Enter Password:"
        continue
    else
        counter=$((counter+1))
        prompt='*'
        password+="$char"
    fi
done

javac not working in windows command prompt

I was having the same problem posted in this title. Java would work, but javac would not in the Windows command prompt (cmd.exe).

For me, it was simply that I had placed a space when adding C:\Program Files\Java\jdk1.8.0\bin to the end of my %PATH% environment variable.
Remove the space between the ; and the next file path.

How to get names of classes inside a jar file?

This is a hack I'm using:

You can use java's autocomplete like this:

java -cp path_to.jar <Tab>

This will give you a list of classes available to pass as the starting class. Of course, trying to use one that has no main file will not do anything, but you can see what java thinks the classes inside the .jar are called.

Calculating the position of points in a circle

The angle between each of your points is going to be 2Pi/x so you can say that for points n= 0 to x-1 the angle from a defined 0 point is 2nPi/x.

Assuming your first point is at (r,0) (where r is the distance from the centre point) then the positions relative to the central point will be:

rCos(2nPi/x),rSin(2nPi/x)

Detect if PHP session exists

If you are on php 5.4+, it is cleaner to use session_status():

if (session_status() == PHP_SESSION_ACTIVE) {
  echo 'Session is active';
}
  • PHP_SESSION_DISABLED if sessions are disabled.
  • PHP_SESSION_NONE if sessions are enabled, but none exists.
  • PHP_SESSION_ACTIVE if sessions are enabled, and one exists.

How to move the cursor word by word in the OS X Terminal

Use Natural Text Editing preset!

enter image description here

Essentially it binds, among other key sequences, Option + LeftArrow to ^[b sequence and Option + RightArrow to ^[f

This works in fish and bash, as well as in psql terminal.

How do I connect to my existing Git repository using Visual Studio Code?

  1. Open Vs Code
  2. Go to view
  3. Click on terminal to open a terminal in VS Code
  4. Copy the link for your existing repository from your GitHub page.
  5. Type “git clone” and paste the link in addition i.e “git clone https://github.com/...”
  6. This will open the repository in your Vs Code Editor.

Node.js/Windows error: ENOENT, stat 'C:\Users\RT\AppData\Roaming\npm'

I recommend setting an alternative location for your npm modules.

npm config set prefix C:\Dev\npm-repository\npm --global 
npm config set cache C:\Dev\npm-repository\npm-cache --global  

Of course you can set the location to wherever best suits.

This has worked well for me and gets around any permissions issues that you may encounter.

Visual Studio Code always asking for git credentials

This has been working for me:
1. Set credential hepler to store
$ git config --global credential.helper store
2. then verify if you want:
$ git config --global credential.helper store

Simple example when using git bash quoted from Here (works for current repo only, use --global for all repos)

$ git config credential.helper store
$ git push http://example.com/repo.git
Username: < type your username >
Password: < type your password >

[several days later]
$ git push http://example.com/repo.git
[your credentials are used automatically]

Will work for VS Code too.

More detailed example and advanced usage here.

Note: Username & Passwords are not encrypted and stored in plain text format so use it on your personal computer only.

what does numpy ndarray shape do?

.shape() gives the actual shape of your array in terms of no of elements in it, No of rows/No of Columns. The answer you get is in the form of tuples.

For Example: 1D ARRAY:

d=np.array([1,2,3,4])
print(d)
(1,)

Output: (4,) ie the number4 denotes the no of elements in the 1D Array.

2D Array:

e=np.array([[1,2,3],[4,5,6]])   
print(e)
(2,3)

Output: (2,3) ie the number of rows and the number of columns.

The number of elements in the final output will depend on the number of rows in the Array....it goes on increasing gradually.

Please initialize the log4j system properly. While running web service

If the below statment is present in your class then your log4j.properties should be in java source(src) folder , if it is jar executable it should be packed in jar not a seperate file.

static Logger log = Logger.getLogger(MyClass.class);

Thanks,

Cannot connect to the Docker daemon on macOS

I had the same problem. Docker running but couldn't access it through CLI.

For me the problem was solved by executing "Docker Quickstart Terminal.app". This is located in the "/Applications/Docker/" folder. As long as I work in this instance of the Terminal app Docker works perfectly. If a second window is needed I have to run the "Quickstart" app once more.

I have a Docker for Mac installation. Therefore I am not sure if my solution is valid for a Homebrew installation.

The "Docker Quickstart Terminal" app seems to be essentially some applescripts to launch the terminal app and a bash start script that initialise all the necessary environment variables.

Hope this helps someone else !

How to exclude 0 from MIN formula Excel

Solutions listed did not exactly work for me. The closest was Chief Wiggum - I wanted to add a comment on his answer but lack the reputation to do so. So I post as separate answer:

=MIN(IF(A1:E1>0;A1:E1))

Then instead of pressing ENTER, press CTRL+SHIFT+ENTER and watch Excel add { and } to respectively the beginning and the end of the formula (to activate the formula on array).

The comma "," and "If" statement as proposed by Chief Wiggum did not work on Excel Home and Student 2013. Need a semicolon ";" as well as full cap "IF" did the trick. Small syntax difference but took me 1.5 hour to figure out why I was getting an error and #VALUE.

What is move semantics?

Move semantics are based on rvalue references.
An rvalue is a temporary object, which is going to be destroyed at the end of the expression. In current C++, rvalues only bind to const references. C++1x will allow non-const rvalue references, spelled T&&, which are references to an rvalue objects.
Since an rvalue is going to die at the end of an expression, you can steal its data. Instead of copying it into another object, you move its data into it.

class X {
public: 
  X(X&& rhs) // ctor taking an rvalue reference, so-called move-ctor
    : data_()
  {
     // since 'x' is an rvalue object, we can steal its data
     this->swap(std::move(rhs));
     // this will leave rhs with the empty data
  }
  void swap(X&& rhs);
  // ... 
};

// ...

X f();

X x = f(); // f() returns result as rvalue, so this calls move-ctor

In the above code, with old compilers the result of f() is copied into x using X's copy constructor. If your compiler supports move semantics and X has a move-constructor, then that is called instead. Since its rhs argument is an rvalue, we know it's not needed any longer and we can steal its value.
So the value is moved from the unnamed temporary returned from f() to x (while the data of x, initialized to an empty X, is moved into the temporary, which will get destroyed after the assignment).

How do I change db schema to dbo

You can batch change schemas of multiple database objects as described in this post:

How to change schema of all tables, views and stored procedures in MSSQL

How do I write dispatch_after GCD in Swift 3, 4, and 5?

try this

let when = DispatchTime.now() + 1.5
    DispatchQueue.main.asyncAfter(deadline: when) {
        //some code
    }

How to safely call an async method in C# without await

On technologies with message loops (not sure if ASP is one of them), you can block the loop and process messages until the task is over, and use ContinueWith to unblock the code:

public void WaitForTask(Task task)
{
    DispatcherFrame frame = new DispatcherFrame();
    task.ContinueWith(t => frame.Continue = false));
    Dispatcher.PushFrame(frame);
}

This approach is similar to blocking on ShowDialog and still keeping the UI responsive.

Fatal error: Please read "Security" section of the manual to find out how to run mysqld as root

On top of @mise's answer, After I installed MacOS Mojave, I also had to change files ownership on all my MAMP directory and contents).

From the Finder, I went in Application/MAMP, showed files info (cmd + i) and in permissions section added myself with read & write perms, then from the little gear applied to all the children.

Send JSON via POST in C# and Receive the JSON returned?

You can build your HttpContent using the combination of JObject to avoid and JProperty and then call ToString() on it when building the StringContent:

        /*{
          "agent": {                             
            "name": "Agent Name",                
            "version": 1                                                          
          },
          "username": "Username",                                   
          "password": "User Password",
          "token": "xxxxxx"
        }*/

        JObject payLoad = new JObject(
            new JProperty("agent", 
                new JObject(
                    new JProperty("name", "Agent Name"),
                    new JProperty("version", 1)
                    ),
                new JProperty("username", "Username"),
                new JProperty("password", "User Password"),
                new JProperty("token", "xxxxxx")    
                )
            );

        using (HttpClient client = new HttpClient())
        {
            var httpContent = new StringContent(payLoad.ToString(), Encoding.UTF8, "application/json");

            using (HttpResponseMessage response = await client.PostAsync(requestUri, httpContent))
            {
                response.EnsureSuccessStatusCode();
                string responseBody = await response.Content.ReadAsStringAsync();
                return JObject.Parse(responseBody);
            }
        }

How to initialize java.util.date to empty

An instance of Date always represents a date and cannot be empty. You can use a null value of date2 to represent "there is no date". You will have to check for null whenever you use date2 to avoid a NullPointerException, like when rendering your page:

if (date2 != null)
  // print date2
else
  // print nothing, or a default value

SQL Server - calculate elapsed time between two datetime stamps in HH:MM:SS format

The best and simple way:

Convert(varchar, {EndTime} - {StartTime}, 108)

Just like Anri noted.

With form validation: why onsubmit="return functionname()" instead of onsubmit="functionname()"?

Returning false from the function will stop the event continuing. I.e. it will stop the form submitting.

i.e.

function someFunction()
{
    if (allow) // For example, checking that a field isn't empty
    {
       return true; // Allow the form to submit
    }
    else
    {
       return false; // Stop the form submitting
    }
}

How can I send large messages with Kafka (over 15MB)?

Minor changes required for Kafka 0.10 and the new consumer compared to laughing_man's answer:

  • Broker: No changes, you still need to increase properties message.max.bytes and replica.fetch.max.bytes. message.max.bytes has to be equal or smaller(*) than replica.fetch.max.bytes.
  • Producer: Increase max.request.size to send the larger message.
  • Consumer: Increase max.partition.fetch.bytes to receive larger messages.

(*) Read the comments to learn more about message.max.bytes<=replica.fetch.max.bytes

adding css class to multiple elements

Try using:

.button input, .button a {
    // css stuff
}

Also, read up on CSS.

Edit: If it were me, I'd add the button class to the element, not to the parent tag. Like so:

HTML:

<a href="#" class='button'>BUTTON TEXT</a>
<input type="submit" class='button' value='buttontext' />

CSS:

.button {
    // css stuff
}

For specific css stuff use:

input.button {
    // css stuff
}
a.button {
    // css stuff
}

Log4net does not write the log in the log file

Also, Make sure the "Copy always" option is selected for [log4net].config

enter image description here

Creating threads - Task.Factory.StartNew vs new Thread()

There is a big difference. Tasks are scheduled on the ThreadPool and could even be executed synchronous if appropiate.

If you have a long running background work you should specify this by using the correct Task Option.

You should prefer Task Parallel Library over explicit thread handling, as it is more optimized. Also you have more features like Continuation.

Bootstrap datetimepicker is not a function

Try to use datepicker/ timepicker instead of datetimepicker like:

replace:

$('#datetimepicker1').datetimepicker();

with:

$('#datetimepicker1').datepicker(); // or timepicker for time picker

What are the rules about using an underscore in a C++ identifier?

The rules (which did not change in C++11):

  • Reserved in any scope, including for use as implementation macros:
    • identifiers beginning with an underscore followed immediately by an uppercase letter
    • identifiers containing adjacent underscores (or "double underscore")
  • Reserved in the global namespace:
    • identifiers beginning with an underscore
  • Also, everything in the std namespace is reserved. (You are allowed to add template specializations, though.)

From the 2003 C++ Standard:

17.4.3.1.2 Global names [lib.global.names]

Certain sets of names and function signatures are always reserved to the implementation:

  • Each name that contains a double underscore (__) or begins with an underscore followed by an uppercase letter (2.11) is reserved to the implementation for any use.
  • Each name that begins with an underscore is reserved to the implementation for use as a name in the global namespace.165

165) Such names are also reserved in namespace ::std (17.4.3.1).

Because C++ is based on the C standard (1.1/2, C++03) and C99 is a normative reference (1.2/1, C++03) these also apply, from the 1999 C Standard:

7.1.3 Reserved identifiers

Each header declares or defines all identifiers listed in its associated subclause, and optionally declares or defines identifiers listed in its associated future library directions subclause and identifiers which are always reserved either for any use or for use as file scope identifiers.

  • All identifiers that begin with an underscore and either an uppercase letter or another underscore are always reserved for any use.
  • All identifiers that begin with an underscore are always reserved for use as identifiers with file scope in both the ordinary and tag name spaces.
  • Each macro name in any of the following subclauses (including the future library directions) is reserved for use as specified if any of its associated headers is included; unless explicitly stated otherwise (see 7.1.4).
  • All identifiers with external linkage in any of the following subclauses (including the future library directions) are always reserved for use as identifiers with external linkage.154
  • Each identifier with file scope listed in any of the following subclauses (including the future library directions) is reserved for use as a macro name and as an identifier with file scope in the same name space if any of its associated headers is included.

No other identifiers are reserved. If the program declares or defines an identifier in a context in which it is reserved (other than as allowed by 7.1.4), or defines a reserved identifier as a macro name, the behavior is undefined.

If the program removes (with #undef) any macro definition of an identifier in the first group listed above, the behavior is undefined.

154) The list of reserved identifiers with external linkage includes errno, math_errhandling, setjmp, and va_end.

Other restrictions might apply. For example, the POSIX standard reserves a lot of identifiers that are likely to show up in normal code:

  • Names beginning with a capital E followed a digit or uppercase letter:
    • may be used for additional error code names.
  • Names that begin with either is or to followed by a lowercase letter
    • may be used for additional character testing and conversion functions.
  • Names that begin with LC_ followed by an uppercase letter
    • may be used for additional macros specifying locale attributes.
  • Names of all existing mathematics functions suffixed with f or l are reserved
    • for corresponding functions that operate on float and long double arguments, respectively.
  • Names that begin with SIG followed by an uppercase letter are reserved
    • for additional signal names.
  • Names that begin with SIG_ followed by an uppercase letter are reserved
    • for additional signal actions.
  • Names beginning with str, mem, or wcs followed by a lowercase letter are reserved
    • for additional string and array functions.
  • Names beginning with PRI or SCN followed by any lowercase letter or X are reserved
    • for additional format specifier macros
  • Names that end with _t are reserved
    • for additional type names.

While using these names for your own purposes right now might not cause a problem, they do raise the possibility of conflict with future versions of that standard.


Personally I just don't start identifiers with underscores. New addition to my rule: Don't use double underscores anywhere, which is easy as I rarely use underscore.

After doing research on this article I no longer end my identifiers with _t as this is reserved by the POSIX standard.

The rule about any identifier ending with _t surprised me a lot. I think that is a POSIX standard (not sure yet) looking for clarification and official chapter and verse. This is from the GNU libtool manual, listing reserved names.

CesarB provided the following link to the POSIX 2004 reserved symbols and notes 'that many other reserved prefixes and suffixes ... can be found there'. The POSIX 2008 reserved symbols are defined here. The restrictions are somewhat more nuanced than those above.

Get list of a class' instance methods

You can get a more detailed list (e.g. structured by defining class) with gems like debugging or looksee.

numbers not allowed (0-9) - Regex Expression in javascript

Something as simple as [a-z]+, or perhaps [\S]+, or even [a-zA-Z]+?

'invalid value encountered in double_scalars' warning, possibly numpy

Sometimes NaNs or null values in data will generate this error with Numpy. If you are ingesting data from say, a CSV file or something like that, and then operating on the data using numpy arrays, the problem could have originated with your data ingest. You could try feeding your code a small set of data with known values, and see if you get the same result.

Best way to find the intersection of multiple sets?

As of 2.6, set.intersection takes arbitrarily many iterables.

>>> s1 = set([1, 2, 3])
>>> s2 = set([2, 3, 4])
>>> s3 = set([2, 4, 6])
>>> s1 & s2 & s3
set([2])
>>> s1.intersection(s2, s3)
set([2])
>>> sets = [s1, s2, s3]
>>> set.intersection(*sets)
set([2])

Converts scss to css

If you click on the title CSS (SCSS) in CodePen (don't change the pre-processor with the gear) it will switch to the compiled CSS view.

Codepen Screenshot of Compiled Preview

How to modify the nodejs request default timeout time?

I'm assuming you're using express, given the logs you have in your question. The key is to set the timeout property on server (the following sets the timeout to one second, use whatever value you want):

var server = app.listen(app.get('port'), function() {
  debug('Express server listening on port ' + server.address().port);
});
server.timeout = 1000;

If you're not using express and are only working with vanilla node, the principle is the same. The following will not return data:

var http = require('http');
var server = http.createServer(function (req, res) {
  setTimeout(function() {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.end('Hello World\n');
  }, 200);
}).listen(1337, '127.0.0.1');

server.timeout = 20;
console.log('Server running at http://127.0.0.1:1337/');

"React.Children.only expected to receive a single React element child" error when putting <Image> and <TouchableHighlight> in a <View>

In my case, I just had to put the element one line down:

This throws an error:

_x000D_
_x000D_
export function DismissKeyboard(props: IProps) {
  return <TouchableWithoutFeedback
    onPress={() => Keyboard.dismiss()}> {props.children}
  </TouchableWithoutFeedback>;
}
_x000D_
_x000D_
_x000D_

While this does not throw an error:

_x000D_
_x000D_
export function DismissKeyboard(props: IProps) {
  return <TouchableWithoutFeedback
    onPress={() => Keyboard.dismiss()}>
    {props.children}
  </TouchableWithoutFeedback>;
}
_x000D_
_x000D_
_x000D_

SQL- Ignore case while searching for a string

Like this.

SELECT DISTINCT COL_NAME FROM myTable WHERE COL_NAME iLIKE '%Priceorder%'

In postgresql.

DB2 Timestamp select statement

You might want to use TRUNC function on your column when comparing with string format, so it compares only till seconds, not milliseconds.

SELECT * FROM <table_name> WHERE id = 1 
AND TRUNC(usagetime, 'SS') = '2012-09-03 08:03:06';

If you wanted to truncate upto minutes, hours, etc. that is also possible, just use appropriate notation instead of 'SS':

hour ('HH'), minute('MI'), year('YEAR' or 'YYYY'), month('MONTH' or 'MM'), Day ('DD')

How to keep form values after post

you can save them into a $_SESSION variable and then when the user calls that page again populate all the inputs with their respective session variables.

How to compare two Carbon Timestamps?

Carbon has a bunch of comparison functions with mnemonic names:

  • equalTo()
  • notEqualTo()
  • greaterThan()
  • greaterThanOrEqualTo()
  • lessThan()
  • lessThanOrEqualTo()

Usage:

 if($model->edited_at->greaterThan($model->created_at)){
     // edited at is newer than created at
 }

Valid for nesbot/carbon 1.36.2

if you are not sure what Carbon version you are on, run this

$composer show "nesbot/carbon"

documentation: https://carbon.nesbot.com/docs/#api-comparison

How to draw a circle with given X and Y coordinates as the middle spot of the circle?

So we are all doing the same home work?

Strange how the most up-voted answer is wrong. Remember, draw/fillOval take height and width as parameters, not the radius. So to correctly draw and center a circle with user-provided x, y, and radius values you would do something like this:

public static void drawCircle(Graphics g, int x, int y, int radius) {

  int diameter = radius * 2;

  //shift x and y by the radius of the circle in order to correctly center it
  g.fillOval(x - radius, y - radius, diameter, diameter); 

}

Yes or No confirm box using jQuery

You can reuse your confirm:

    function doConfirm(body, $_nombrefuncion)
    {   var param = undefined;
        var $confirm = $("<div id='confirm' class='hide'></div>").dialog({
            autoOpen: false,
            buttons: {
                Yes: function() {
                param = true;
                $_nombrefuncion(param);
                $(this).dialog('close');
            },
                No: function() {
                param = false;
                $_nombrefuncion(param);
                $(this).dialog('close');
            }
                                    }
        });
        $confirm.html("<h3>"+body+"<h3>");
        $confirm.dialog('open');                                     
    };

// for this form just u must change or create a new function for to reuse the confirm
    function resultadoconfirmresetVTyBFD(param){
        $fecha = $("#asigfecha").val();
        if(param ==true){
              // DO THE CONFIRM
        }
    }

//Now just u must call the function doConfirm
    doConfirm('body message',resultadoconfirmresetVTyBFD);

Detailed 500 error message, ASP + IIS 7.5

In my case it was permission issue. Open application folder properties -> Security tab -> Edit -> Add

  • IIS AppPool\[DefaultAppPool or any other apppool] (if use ApplicationPoolIdentity option)
  • IUSRS
  • IIS_IUSRS

Interface type check with Typescript

You can validate a TypeScript type at runtime using ts-validate-type, like so (does require a Babel plugin though):

const user = validateType<{ name: string }>(data);

Selenium using Python - Geckodriver executable needs to be in PATH

Selenium answers this question in their DESCRIPTION.rst file:

Drivers
=======

Selenium requires a driver to interface with the chosen browser. Firefox, for example, requires geckodriver <https://github.com/mozilla/geckodriver/releases>_, which needs to be installed before the below examples can be run. Make sure it's in your PATH, e. g., place it in /usr/bin or /usr/local/bin.

Failure to observe this step will give you an error `selenium.common.exceptions.WebDriverException: Message: 'geckodriver' executable needs to be in PATH.

Basically just download the geckodriver, unpack it and move the executable to your /usr/bin folder.

Laravel Mail::send() sending to multiple to or bcc addresses

You can loop over recipientce like:

foreach (['[email protected]', '[email protected]'] as $recipient) {
    Mail::to($recipient)->send(new OrderShipped($order));
}

See documentation here

Cannot find module cv2 when using OpenCV

I solved my issue using the following command :

conda install opencv

Pointer-to-pointer dynamic two-dimensional array

this can be done this way

  1. I have used Operator Overloading
  2. Overloaded Assignment
  3. Overloaded Copy Constructor

    /*
     * Soumil Nitin SHah
     * Github: https://github.com/soumilshah1995
     */
    
    #include <iostream>
    using namespace std;
            class Matrix{
    
    public:
        /*
         * Declare the Row and Column
         *
         */
        int r_size;
        int c_size;
        int **arr;
    
    public:
        /*
         * Constructor and Destructor
         */
    
        Matrix(int r_size, int c_size):r_size{r_size},c_size{c_size}
        {
            arr = new int*[r_size];
            // This Creates a 2-D Pointers
            for (int i=0 ;i < r_size; i++)
            {
                arr[i] = new int[c_size];
            }
    
            // Initialize all the Vector to 0 initially
            for (int row=0; row<r_size; row ++)
            {
                for (int column=0; column < c_size; column ++)
                {
                    arr[row][column] = 0;
                }
            }
            std::cout << "Constructor -- creating Array Size ::" << r_size << " " << c_size << endl;
        }
    
        ~Matrix()
        {
            std::cout << "Destructpr  -- Deleting  Array Size ::" << r_size <<" " << c_size << endl;
    
        }
    
        Matrix(const Matrix &source):Matrix(source.r_size, source.c_size)
    
        {
            for (int row=0; row<source.r_size; row ++)
            {
                for (int column=0; column < source.c_size; column ++)
                {
                    arr[row][column] = source.arr[row][column];
                }
            }
    
            cout << "Copy Constructor " << endl;
        }
    
    
    public:
        /*
         * Operator Overloading
         */
    
        friend std::ostream &operator<<(std::ostream &os, Matrix & rhs)
        {
            int rowCounter = 0;
            int columnCOUNTER = 0;
            int globalCounter = 0;
    
            for (int row =0; row < rhs.r_size; row ++)
            {
                for (int column=0; column < rhs.c_size ; column++)
                {
                    globalCounter = globalCounter + 1;
                }
                rowCounter = rowCounter + 1;
            }
    
    
            os << "Total There are " << globalCounter << " Elements" << endl;
            os << "Array Elements are as follow -------" << endl;
            os << "\n";
    
            for (int row =0; row < rhs.r_size; row ++)
            {
                for (int column=0; column < rhs.c_size ; column++)
                {
                    os << rhs.arr[row][column] << " ";
                }
            os <<"\n";
            }
            return os;
        }
    
        void operator()(int row, int column , int Data)
        {
            arr[row][column] = Data;
        }
    
        int &operator()(int row, int column)
        {
            return arr[row][column];
        }
    
        Matrix &operator=(Matrix &rhs)
                {
                    cout << "Assingment Operator called " << endl;cout <<"\n";
                    if(this == &rhs)
                    {
                        return *this;
                    } else
                        {
                        delete [] arr;
    
                            arr = new int*[r_size];
                            // This Creates a 2-D Pointers
                            for (int i=0 ;i < r_size; i++)
                            {
                                arr[i] = new int[c_size];
                            }
    
                            // Initialize all the Vector to 0 initially
                            for (int row=0; row<r_size; row ++)
                            {
                                for (int column=0; column < c_size; column ++)
                                {
                                    arr[row][column] = rhs.arr[row][column];
                                }
                            }
    
                            return *this;
                        }
    
                }
    
    };
    
                int main()
    {
    
        Matrix m1(3,3);         // Initialize Matrix 3x3
    
        cout << m1;cout << "\n";
    
        m1(0,0,1);
        m1(0,1,2);
        m1(0,2,3);
    
        m1(1,0,4);
        m1(1,1,5);
        m1(1,2,6);
    
        m1(2,0,7);
        m1(2,1,8);
        m1(2,2,9);
    
        cout << m1;cout <<"\n";             // print Matrix
        cout << "Element at Position (1,2) : " << m1(1,2) << endl;
    
        Matrix m2(3,3);
        m2 = m1;
        cout << m2;cout <<"\n";
    
        print(m2);
    
        return 0;
    }
    

How to load assemblies in PowerShell?

You can load the whole *.dll assembly with

$Assembly = [System.Reflection.Assembly]::LoadFrom("C:\folder\file.dll");

api-ms-win-crt-runtime-l1-1-0.dll is missing when opening Microsoft Office file

While the answer from alireza is correct, it has one gotcha:

You can't install Microsoft Visual C++ 2015 redist (runtime) unless you have Windows Update KB2999226 installed (at least on Windows 7 64-bit SP1).

Responsive css styles on mobile devices ONLY

Why not use a media query range.

I'm currently working on a responsive layout for my employer and the ranges I'm using are as follows:

You have your main desktop styles in the body of the CSS file (1024px and above) and then for specific screen sizes I'm using:

@media all and (min-width:960px) and (max-width: 1024px) {
  /* put your css styles in here */
}

@media all and (min-width:801px) and (max-width: 959px) {
  /* put your css styles in here */
}

@media all and (min-width:769px) and (max-width: 800px) {
  /* put your css styles in here */
}

@media all and (min-width:569px) and (max-width: 768px) {
  /* put your css styles in here */
}

@media all and (min-width:481px) and (max-width: 568px) {
  /* put your css styles in here */
}

@media all and (min-width:321px) and (max-width: 480px) {
  /* put your css styles in here */
}

@media all and (min-width:0px) and (max-width: 320px) {
  /* put your css styles in here */
}

This will cover pretty much all devices being used - I would concentrate on getting the styling correct for the sizes at the end of the range (i.e. 320, 480, 568, 768, 800, 1024) as for all the others they will just be responsive to the size available.

Also, don't use px anywhere - use em's or %.

How do I install PyCrypto on Windows?

Step 1: Install Visual C++ 2010 Express from here.

(Do not install Microsoft Visual Studio 2010 Service Pack 1 )

Step 2: Remove all the Microsoft Visual C++ 2010 Redistributable packages from Control Panel\Programs and Features. If you don't do those then the install is going to fail with an obscure "Fatal error during installation" error.

Step 3: Install offline version of Windows SDK for Visual Studio 2010 (v7.1) from here. This is required for 64bit extensions. Windows has builtin mounting for ISOs like Pismo.

Step 4: You need to install the ISO file with Pismo File Mount Audit Package. Download Pismo from here

Step 5: Right click the downloaded ISO file and choose mount with Pismo. Thereafter, install the Setup\SDKSetup.exe instead of setup.exe.

Step 6a: Create a vcvars64.bat file in C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\bin\amd64 by changing directory to C:\Program Files (x86)\Microsoft Visual Studio version\VC\ on the command prompt. Type command on the command prompt: cd C:\Program Files (x86)\Microsoft Visual Studio version\VC\r

Step 6b: To configure this Command Prompt window for 64-bit command-line builds that target x86 platforms, at the command prompt, enter: vcvarsall x86 Click here for more options.

Step 7: At the command prompt, install the PyCrypto by typing: C:\Python3X>pip install -U your_wh_file

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

Capslock + Tab to indent multiple lines at once. Highlight the text first.

Yarn install command error No such file or directory: 'install'

Tried above steps, didn't work on Ubuntu 20. For Ubuntu 20, remove the cmdtest and yarn like suggested above. Install yarn with below commands:

curl -sL https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -

echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list

sudo apt update && sudo apt install yarn

How can I login to a website with Python?

Maybe you want to use twill. It's quite easy to use and should be able to do what you want.

It will look like the following:

from twill.commands import *
go('http://example.org')

fv("1", "email-email", "blabla.com")
fv("1", "password-clear", "testpass")

submit('0')

You can use showforms() to list all forms once you used go… to browse to the site you want to login. Just try it from the python interpreter.

Eclipse doesn't stop at breakpoints

I suddenly experienced the skipping of breakpoints as well in Eclipse Juno CDT. For me the issue was that I had set optimization levels up. Once I set it back to none it was working fine. To set optimization levels go to Project Properties -> C/C++ Build -> Settings -> Tool Settings pan depending on which compiler you are using go to -> Optimization and set Optimization Level to: None (-O0). Hope this helps! Best

How do I determine whether my calculation of pi is accurate?

Since I'm the current world record holder for the most digits of pi, I'll add my two cents:

Unless you're actually setting a new world record, the common practice is just to verify the computed digits against the known values. So that's simple enough.

In fact, I have a webpage that lists snippets of digits for the purpose of verifying computations against them: http://www.numberworld.org/digits/Pi/


But when you get into world-record territory, there's nothing to compare against.

Historically, the standard approach for verifying that computed digits are correct is to recompute the digits using a second algorithm. So if either computation goes bad, the digits at the end won't match.

This does typically more than double the amount of time needed (since the second algorithm is usually slower). But it's the only way to verify the computed digits once you've wandered into the uncharted territory of never-before-computed digits and a new world record.


Back in the days where supercomputers were setting the records, two different AGM algorithms were commonly used:

These are both O(N log(N)^2) algorithms that were fairly easy to implement.

However, nowadays, things are a bit different. In the last three world records, instead of performing two computations, we performed only one computation using the fastest known formula (Chudnovsky Formula):

Enter image description here

This algorithm is much harder to implement, but it is a lot faster than the AGM algorithms.

Then we verify the binary digits using the BBP formulas for digit extraction.

Enter image description here

This formula allows you to compute arbitrary binary digits without computing all the digits before it. So it is used to verify the last few computed binary digits. Therefore it is much faster than a full computation.

The advantage of this is:

  1. Only one expensive computation is needed.

The disadvantage is:

  1. An implementation of the Bailey–Borwein–Plouffe (BBP) formula is needed.
  2. An additional step is needed to verify the radix conversion from binary to decimal.

I've glossed over some details of why verifying the last few digits implies that all the digits are correct. But it is easy to see this since any computation error will propagate to the last digits.


Now this last step (verifying the conversion) is actually fairly important. One of the previous world record holders actually called us out on this because, initially, I didn't give a sufficient description of how it worked.

So I've pulled this snippet from my blog:

N = # of decimal digits desired
p = 64-bit prime number

Enter image description here

Compute A using base 10 arithmetic and B using binary arithmetic.

Enter image description here

If A = B, then with "extremely high probability", the conversion is correct.


For further reading, see my blog post Pi - 5 Trillion Digits.

HTML 5 Video "autoplay" not automatically starting in CHROME

This may not have been the case at the time the question was asked, but as of Chrome 66, autoplay is blocked.

http://bgr.com/2018/04/18/google-chrome-66-download-auto-playing-videos-block/

Excel is not updating cells, options > formula > workbook calculation set to automatic

In short

creating or moving some/all reference containing worksheets (out and) into your workbook may solve it.

More details

I had this issue after copying some sheets from "template" sheets/workbooks to some new "destination" workbook (the templates were provided by other users!):

I got:

  • workbook WbTempl1
    • with sheet WsTempl1RefDef (defining the references used e.g. in WsTempl2RefUsr below, e.g. project on A1)
  • workbook WbTempl2 (above references do not exist, because WsTempl1RefDef is not contained nor externally referenced, e.g. like WbTempl2.Names("project").refersTo="C:\WbTempl1.xls]'WsTempl1RefDef!A1")
    • contains sheet WsTempl2RefUsr (uses inexisting global references, e.g. =project)

and wanted to create a WbDst to copy WsTempl1RefDef and WsTempl2RefUsr into it.


The following did not work:

  1. create workbook WbDst
  2. copy sheet WsTempl1RefDef into it (references were locally created)
  3. copy sheet WsTempl2RefUsr into it

Here as well the Ctrl(SHIFT)ALTF9 nor Application.CalculateFullRebuild worked on WbDst.


The following worked:

  1. create workbook WbDst
  2. move (not copy) sheet WsTempl1RefDef into WbTempl2
    • (we do not have to save them)
  3. copy sheet WsTempl1RefDef into WbDst
  4. copy sheet WsTempl2RefUsr into WbDst

Automatic exit from Bash shell script on error

One point missed in the existing answers is show how to inherit the error traps. The bash shell provides one such option for that using set

-E

If set, any trap on ERR is inherited by shell functions, command substitutions, and commands executed in a subshell environment. The ERR trap is normally not inherited in such cases.


Adam Rosenfield's answer recommendation to use set -e is right in certain cases but it has its own potential pitfalls. See GreyCat's BashFAQ - 105 - Why doesn't set -e (or set -o errexit, or trap ERR) do what I expected?

According to the manual, set -e exits

if a simple commandexits with a non-zero status. The shell does not exit if the command that fails is part of the command list immediately following a while or until keyword, part of the test in a if statement, part of an && or || list except the command following the final && or ||, any command in a pipeline but the last, or if the command's return value is being inverted via !".

which means, set -e does not work under the following simple cases (detailed explanations can be found on the wiki)

  1. Using the arithmetic operator let or $((..)) ( bash 4.1 onwards) to increment a variable value as

    #!/usr/bin/env bash
    set -e
    i=0
    let i++                   # or ((i++)) on bash 4.1 or later
    echo "i is $i" 
    
  2. If the offending command is not part of the last command executed via && or ||. For e.g. the below trap wouldn't fire when its expected to

    #!/usr/bin/env bash
    set -e
    test -d nosuchdir && echo no dir
    echo survived
    
  3. When used incorrectly in an if statement as, the exit code of the if statement is the exit code of the last executed command. In the example below the last executed command was echo which wouldn't fire the trap, even though the test -d failed

    #!/usr/bin/env bash
    set -e
    f() { if test -d nosuchdir; then echo no dir; fi; }
    f 
    echo survived
    
  4. When used with command-substitution, they are ignored, unless inherit_errexit is set with bash 4.4

    #!/usr/bin/env bash
    set -e
    foo=$(expr 1-1; true)
    echo survived
    
  5. when you use commands that look like assignments but aren't, such as export, declare, typeset or local. Here the function call to f will not exit as local has swept the error code that was set previously.

    set -e
    f() { local var=$(somecommand that fails); }        
    g() { local var; var=$(somecommand that fails); }
    
  6. When used in a pipeline, and the offending command is not part of the last command. For e.g. the below command would still go through. One options is to enable pipefail by returning the exit code of the first failed process:

    set -e
    somecommand that fails | cat -
    echo survived
    

The ideal recommendation is to not use set -e and implement an own version of error checking instead. More information on implementing custom error handling on one of my answers to Raise error in a Bash script

HTTP Error 500.19 and error code : 0x80070021

I solved this by doing the following:

WebServer(ISS)->WebServer->Application Development
add .NET Extensibility 3.5
add .NET Extensibility 4.5
add ASP.NET 4.5
add ISAPI Extensions
add ISAPI Filters

enter image description here

Is there a css cross-browser value for "width: -moz-fit-content;"?

Is there a single declaration that fixes this for Webkit, Gecko, and Blink? No. However, there is a cross-browser solution by specifying multiple width property values that correspond to each layout engine's convention.

.mydiv {  
  ...
  width: intrinsic;           /* Safari/WebKit uses a non-standard name */
  width: -moz-max-content;    /* Firefox/Gecko */
  width: -webkit-max-content; /* Chrome */
  ...
}

Adapted from: MDN

Email address validation using ASP.NET MVC data type attributes

[Required(ErrorMessage = "Please enter Social Email id")]
    [DataType(DataType.EmailAddress)]
    [EmailAddress]
    public string Email { get; set; }

How to extract public key using OpenSSL?

For those interested in the details - you can see what's inside the public key file (generated as explained above), by doing this:-

openssl rsa -noout -text -inform PEM -in key.pub -pubin

or for the private key file, this:-

openssl rsa -noout -text -in key.private

which outputs as text on the console the actual components of the key (modulus, exponents, primes, ...)

How to convert a timezone aware string to datetime in Python without dateutil?

You can convert like this.

date = datetime.datetime.strptime('2019-3-16T5-49-52-595Z','%Y-%m-%dT%H-%M-%S-%f%z')
date_time = date.strftime('%Y-%m-%dT%H:%M:%S.%fZ')

How to determine if a number is positive or negative?

Integers are trivial; this you already know. The deep problem is how to deal with floating-point values. At that point, you've got to know a bit more about how floating point values actually work.

The key is Double.doubleToLongBits(), which lets you get at the IEEE representation of the number. (The method's really a direct cast under the hood, with a bit of magic for dealing with NaN values.) Once a double has been converted to a long, you can just use 0x8000000000000000L as a mask to select the sign bit; if zero, the value is positive, and if one, it's negative.

How to load a model from an HDF5 file in Keras?

I done in this way

from keras.models import Sequential
from keras_contrib.losses import import crf_loss
from keras_contrib.metrics import crf_viterbi_accuracy

# To save model
model.save('my_model_01.hdf5')

# To load the model
custom_objects={'CRF': CRF,'crf_loss': crf_loss,'crf_viterbi_accuracy':crf_viterbi_accuracy}

# To load a persisted model that uses the CRF layer 
model1 = load_model("/home/abc/my_model_01.hdf5", custom_objects = custom_objects)

Creating a file name as a timestamp in a batch job

For big zip files for deployment, I use quarter hours. No one else on this page had mentioned it before, so I'll put my small script here:

set /a "quarter_hours=%time:~0,2%*4 + %time:~3,2% / 15"
set "zip_file=release_%DATE:~-4%.%DATE:~4,2%.%DATE:~7,2%.%quarter_hours%.zip"

It doesn't zero pad quarter hours from midnight to 5am yet, but it still makes it so you can have a stamped release multiple times a day with few collisions.

Hope that helps.

What is a Subclass

Think of a class as a description of the members of a set of things. All of the members of that set have common characteristics (methods and properties).

A subclass is a class that describes the members of a particular subset of the original set. They share many of characteristics of the main class, but may have properties or methods that are unique to members of the subclass.

You declare that one class is subclass of another via the "extends" keyword in Java.

public class B extends A
{
...
}

B is a subclass of A. Instances of class B will automatically exhibit many of the same properties as instances of class A.

This is the main concept of inheritance in Object-Oriented programming.

Mysql service is missing

Go to

C:\Program Files\MySQL\MySQL Server 5.2\bin

then Open MySQLInstanceConfig file

then complete the wizard.

Click finish

Solve the problem

I think this is the best way to change the port number also.

It works for me

How to escape indicator characters (i.e. : or - ) in YAML

Another way that works with the YAML parser used in Jekyll:

title: My Life&#58; A Memoir

Colons not followed by spaces don't seem to bother Jekyll's YAML parser, on the other hand. Neither do dashes.

RESTful Authentication

I think restful authentication involves the passing of an authentication token as a parameter in the request. Examples are the use of apikeys by api's. I don't believe the use of cookies or http auth qualifies.

How to make a launcher

They're examples provided by the Android team, if you've already loaded Samples, you can import Home screen replacement sample by following these steps.

File > New > Other >Android > Android Sample Project > Android x.x > Home > Finish

But if you do not have samples loaded, then download it using the below steps

Windows > Android SDK Manager > chooses "Sample for SDK" for SDK you need it > Install package > Accept License > Install