Programs & Examples On #Cortex a8

The ARM Cortex-A8 processor is based on the ARMv7 architecture and has the ability to scale in speed from 600MHz to greater than 1GHz. The Cortex-A8 processor can meet the requirements for power-optimized mobile devices needing operation in less than 300mW; and performance-optimized consumer applications requiring 2000 Dhrystone MIPS.

Installation error: INSTALL_FAILED_OLDER_SDK

I am using Android Studio 0.8.1. I have a project's gradle file like below:

android {
    compileSdkVersion 19
    buildToolsVersion "20.0.0"

    defaultConfig {
        applicationId "com.omersonmez.widgets.hotspot"
        minSdkVersion 15
        targetSdkVersion 19
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            runProguard false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

My emulator was android 4.0. So i modified my emulator and made api level 4.0.3(apilevel 15). It worked.

What does appending "?v=1" to CSS and JavaScript URLs in link and script tags do?

These are usually to make sure that the browser gets a new version when the site gets updated with a new version, e.g. as part of our build process we'd have something like this:

/Resources/Combined.css?v=x.x.x.buildnumber

Since this changes with every new code push, the client's forced to grab a new version, just because of the querystring. Look at this page (at the time of this answer) for example:

<link ... href="http://sstatic.net/stackoverflow/all.css?v=c298c7f8233d">

I think instead of a revision number the SO team went with a file hash, which is an even better approach, even with a new release, the browsers only forced to grab a new version when the file actually changes.

Both of these approaches allow you to set the cache header to something ridiculously long, say 20 years...yet when it changes, you don't have to worry about that cache header, the browser sees a different querystring and treats it as a different, new file.

Storing images in SQL Server?

I would prefer to store the image in a directory, then store a reference to the image file in the database.

However, if you do store the image in the database, you should partition your database so the image column resides in a separate file.

You can read more about using filegroups here http://msdn.microsoft.com/en-us/library/ms179316.aspx.

Operation Not Permitted when on root - El Capitan (rootless disabled)

If after calling "csrutil disabled" still your command does not work, try with "sudo" in terminal, for example:

sudo mv geckodriver /usr/local/bin

And it should work.

How to share my Docker-Image without using the Docker-Hub?

Docker images are stored as filesystem layers. Every command in the Dockerfile creates a layer. You can also create layers by using docker commit from the command line after making some changes (via docker run probably).

These layers are stored by default under /var/lib/docker. While you could (theoretically) cherry pick files from there and install it in a different docker server, is probably a bad idea to play with the internal representation used by Docker.

When you push your image, these layers are sent to the registry (the docker hub registry, by default… unless you tag your image with another registry prefix) and stored there. When pushing, the layer id is used to check if you already have the layer locally or it needs to be downloaded. You can use docker history to peek at which layers (other images) are used (and, to some extent, which command created the layer).

As for options to share an image without pushing to the docker hub registry, your best options are:

  • docker save an image or docker export a container. This will output a tar file to standard output, so you will like to do something like docker save 'dockerizeit/agent' > dk.agent.latest.tar. Then you can use docker load or docker import in a different host.

  • Host your own private registry. - Outdated, see comments See the docker registry image. We have built an s3 backed registry which you can start and stop as needed (all state is kept on the s3 bucket of your choice) which is trivial to setup. This is also an interesting way of watching what happens when pushing to a registry

  • Use another registry like quay.io (I haven't personally tried it), although whatever concerns you have with the docker hub will probably apply here too.

How do I install g++ on MacOS X?

Download Xcode, which is free with an ADC online membership (also free):

http://developer.apple.com/technology/xcode.html

How do I best silence a warning about unused variables?

Use compiler's flag, e.g. flag for GCC: -Wno-unused-variable

Updating Python on Mac

Its always best to use homebrew to update or install python. In terminal type:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)

This will install homebrew (it takes sometime depending on your internet speed)

Then, in terminal, type

brew update

This will first update brew (you don't have to do that if you already have the latest version)

then type

brew upgrade python

This brew will update python to the latest viable version.

That should do it.

What is the newline character in the C language: \r or \n?

What is the newline character in the C language: \r or \n?

The new-line may be thought of a some char and it has the value of '\n'. C11 5.2.1

This C new-line comes up in 3 places: C source code, as a single char and as an end-of-line in file I/O when in text mode.

  1. Many compilers will treat source text as ASCII. In that case, codes 10, sometimes 13, and sometimes paired 13,10 as new-line for source code. Had the source code been in another character set, different codes may be used. This new-line typically marks the end of a line of source code (actually a bit more complicated here), // comment, and # directives.

  2. In source code, the 2 characters \ and n represent the char new-line as \n. If ASCII is used, this char would have the value of 10.

  3. In file I/O, in text mode, upon reading the bytes of the input file (and stdin), depending on the environment, when bytes with the value(s) of 10 (Unix), 13,10, (*1) (Windows), 13 (Old Mac??) and other variations are translated in to a '\n'. Upon writing a file (or stdout), the reverse translation occurs.
    Note: File I/O in binary mode makes no translation.

The '\r' in source code is the carriage return char.

(*1) A lone 13 and/or 10 may also translate into \n.

What do hjust and vjust do when making a plot using ggplot?

The value of hjust and vjust are only defined between 0 and 1:

  • 0 means left-justified
  • 1 means right-justified

Source: ggplot2, Hadley Wickham, page 196

(Yes, I know that in most cases you can use it beyond this range, but don't expect it to behave in any specific way. This is outside spec.)

hjust controls horizontal justification and vjust controls vertical justification.

An example should make this clear:

td <- expand.grid(
    hjust=c(0, 0.5, 1),
    vjust=c(0, 0.5, 1),
    angle=c(0, 45, 90),
    text="text"
)

ggplot(td, aes(x=hjust, y=vjust)) + 
    geom_point() +
    geom_text(aes(label=text, angle=angle, hjust=hjust, vjust=vjust)) + 
    facet_grid(~angle) +
    scale_x_continuous(breaks=c(0, 0.5, 1), expand=c(0, 0.2)) +
    scale_y_continuous(breaks=c(0, 0.5, 1), expand=c(0, 0.2))

enter image description here


To understand what happens when you change the hjust in axis text, you need to understand that the horizontal alignment for axis text is defined in relation not to the x-axis, but to the entire plot (where this includes the y-axis text). (This is, in my view, unfortunate. It would be much more useful to have the alignment relative to the axis.)

DF <- data.frame(x=LETTERS[1:3],y=1:3)
p <- ggplot(DF, aes(x,y)) + geom_point() + 
    ylab("Very long label for y") +
    theme(axis.title.y=element_text(angle=0))


p1 <- p + theme(axis.title.x=element_text(hjust=0)) + xlab("X-axis at hjust=0")
p2 <- p + theme(axis.title.x=element_text(hjust=0.5)) + xlab("X-axis at hjust=0.5")
p3 <- p + theme(axis.title.x=element_text(hjust=1)) + xlab("X-axis at hjust=1")

library(ggExtra)
align.plots(p1, p2, p3)

enter image description here


To explore what happens with vjust aligment of axis labels:

DF <- data.frame(x=c("a\na","b","cdefghijk","l"),y=1:4)
p <- ggplot(DF, aes(x,y)) + geom_point()

p1 <- p + theme(axis.text.x=element_text(vjust=0, colour="red")) + 
        xlab("X-axis labels aligned with vjust=0")
p2 <- p + theme(axis.text.x=element_text(vjust=0.5, colour="red")) + 
        xlab("X-axis labels aligned with vjust=0.5")
p3 <- p + theme(axis.text.x=element_text(vjust=1, colour="red")) + 
        xlab("X-axis labels aligned with vjust=1")


library(ggExtra)
align.plots(p1, p2, p3)

enter image description here

How to join multiple collections with $lookup in mongodb

The join feature supported by Mongodb 3.2 and later versions. You can use joins by using aggregate query.
You can do it using below example :

db.users.aggregate([

    // Join with user_info table
    {
        $lookup:{
            from: "userinfo",       // other table name
            localField: "userId",   // name of users table field
            foreignField: "userId", // name of userinfo table field
            as: "user_info"         // alias for userinfo table
        }
    },
    {   $unwind:"$user_info" },     // $unwind used for getting data in object or for one record only

    // Join with user_role table
    {
        $lookup:{
            from: "userrole", 
            localField: "userId", 
            foreignField: "userId",
            as: "user_role"
        }
    },
    {   $unwind:"$user_role" },

    // define some conditions here 
    {
        $match:{
            $and:[{"userName" : "admin"}]
        }
    },

    // define which fields are you want to fetch
    {   
        $project:{
            _id : 1,
            email : 1,
            userName : 1,
            userPhone : "$user_info.phone",
            role : "$user_role.role",
        } 
    }
]);

This will give result like this:

{
    "_id" : ObjectId("5684f3c454b1fd6926c324fd"),
    "email" : "[email protected]",
    "userName" : "admin",
    "userPhone" : "0000000000",
    "role" : "admin"
}

Hope this will help you or someone else.

Thanks

How do I monitor the computer's CPU, memory, and disk usage in Java?

For disk space, if you have Java 6, you can use the getTotalSpace and getFreeSpace methods on File. If you're not on Java 6, I believe you can use Apache Commons IO to get some of the way there.

I don't know of any cross platform way to get CPU usage or Memory usage I'm afraid.

JavaScript file not updating no matter what I do

I was going insane trying to get my js files to refresh and I tried everything. Then I did a header check and remembered I was using Cloudflare!

In Cloudflare you can use dev mode to disable proxy.

How to use java.String.format in Scala?

This is a list of what String.format can do. The same goes for printf

int i = 123;
o.printf( "|%d|%d|%n" ,       i, -i );      // |123|-123|
o.printf( "|%5d|%5d|%n" ,     i, -i );      // |  123| –123|
o.printf( "|%-5d|%-5d|%n" ,   i, -i );      // |123  |-123 |
o.printf( "|%+-5d|%+-5d|%n" , i, -i );      // |+123 |-123 |
o.printf( "|%05d|%05d|%n%n",  i, -i );      // |00123|-0123|

o.printf( "|%X|%x|%n", 0xabc, 0xabc );      // |ABC|abc|
o.printf( "|%04x|%#x|%n%n", 0xabc, 0xabc ); // |0abc|0xabc|

double d = 12345.678;
o.printf( "|%f|%f|%n" ,         d, -d );    // |12345,678000|     |-12345,678000|
o.printf( "|%+f|%+f|%n" ,       d, -d );    // |+12345,678000| |-12345,678000|
o.printf( "|% f|% f|%n" ,       d, -d );    // | 12345,678000| |-12345,678000|
o.printf( "|%.2f|%.2f|%n" ,     d, -d );    // |12345,68| |-12345,68|
o.printf( "|%,.2f|%,.2f|%n" ,   d, -d );    // |12.345,68| |-12.345,68|
o.printf( "|%.2f|%(.2f|%n",     d, -d );    // |12345,68| |(12345,68)|
o.printf( "|%10.2f|%10.2f|%n" , d, -d );    // |  12345,68| | –12345,68|
o.printf( "|%010.2f|%010.2f|%n",d, -d );    // |0012345,68| |-012345,68|

String s = "Monsterbacke";
o.printf( "%n|%s|%n", s );                  // |Monsterbacke|
o.printf( "|%S|%n", s );                    // |MONSTERBACKE|
o.printf( "|%20s|%n", s );                  // |        Monsterbacke|
o.printf( "|%-20s|%n", s );                 // |Monsterbacke        |
o.printf( "|%7s|%n", s );                   // |Monsterbacke|
o.printf( "|%.7s|%n", s );                  // |Monster|
o.printf( "|%20.7s|%n", s );                // |             Monster|

Date t = new Date();
o.printf( "%tT%n", t );                     // 11:01:39
o.printf( "%tD%n", t );                     // 04/18/08
o.printf( "%1$te. %1$tb%n", t );            // 18. Apr

Binding Button click to a method

You have various possibilies. The most simple and the most ugly is:

XAML

<Button Name="cmdCommand" Click="Button_Clicked" Content="Command"/> 

Code Behind

private void Button_Clicked(object sender, RoutedEventArgs e) { 
    FrameworkElement fe=sender as FrameworkElement;
    ((YourClass)fe.DataContext).DoYourCommand();     
} 

Another solution (better) is to provide a ICommand-property on your YourClass. This command will have already a reference to your YourClass-object and therefore can execute an action on this class.

XAML

<Button Name="cmdCommand" Command="{Binding YourICommandReturningProperty}" Content="Command"/>

Because during writing this answer, a lot of other answers were posted, I stop writing more. If you are interested in one of the ways I showed or if you think I have made a mistake, make a comment.

<xsl:variable> Print out value of XSL variable using <xsl:value-of>

Your main problem is thinking that the variable you declared outside of the template is the same variable being "set" inside the choose statement. This is not how XSLT works, the variable cannot be reassigned. This is something more like what you want:

<xsl:template match="class">
  <xsl:copy><xsl:apply-templates select="@*|node()"/></xsl:copy>
  <xsl:variable name="subexists">
    <xsl:choose>
      <xsl:when test="joined-subclass">true</xsl:when>
      <xsl:otherwise>false</xsl:otherwise>
    </xsl:choose>
  </xsl:variable>
  subexists:      <xsl:value-of select="$subexists" />
</xsl:template>

And if you need the variable to have "global" scope then declare it outside of the template:

<xsl:variable name="subexists">
  <xsl:choose>
     <xsl:when test="/path/to/node/joined-subclass">true</xsl:when>
     <xsl:otherwise>false</xsl:otherwise>
  </xsl:choose>
</xsl:variable>

<xsl:template match="class">
   subexists:      <xsl:value-of select="$subexists" />
</xsl:template>

Android: disabling highlight on listView click

RoflcoptrException's answer should do the trick,but for some reason it did not work for me, So I am posting the solution which worked for me, hope it helps someone

<ListView 
android:listSelector="@android:color/transparent" 
android:cacheColorHint="@android:color/transparent"
/>

Install MySQL on Ubuntu without a password prompt

This should do the trick

export DEBIAN_FRONTEND=noninteractive
sudo -E apt-get -q -y install mysql-server

Of course, it leaves you with a blank root password - so you'll want to run something like

mysqladmin -u root password mysecretpasswordgoeshere

Afterwards to add a password to the account.

How to hash some string with sha256 in Java?

import java.security.MessageDigest;

public class CodeSnippets {

 public static String getSha256(String value) {
    try{
        MessageDigest md = MessageDigest.getInstance("SHA-256");
        md.update(value.getBytes());
        return bytesToHex(md.digest());
    } catch(Exception ex){
        throw new RuntimeException(ex);
    }
 }
 private static String bytesToHex(byte[] bytes) {
    StringBuffer result = new StringBuffer();
    for (byte b : bytes) result.append(Integer.toString((b & 0xff) + 0x100, 16).substring(1));
    return result.toString();
 }
}

Java: Check if command line arguments are null

The arguments can never be null. They just wont exist.

In other words, what you need to do is check the length of your arguments.

public static void main(String[] args)
{
    // Check how many arguments were passed in
    if(args.length == 0)
    {
        System.out.println("Proper Usage is: java program filename");
        System.exit(0);
    }
}

How to alter a column and change the default value?

ALTER TABLE foobar_data MODIFY COLUMN col VARCHAR(255) NOT NULL DEFAULT '{}';

A second possibility which does the same (thanks to juergen_d):

ALTER TABLE foobar_data CHANGE COLUMN col col VARCHAR(255) NOT NULL DEFAULT '{}';

Is there 'byte' data type in C++?

Yes, there is std::byte (defined in <cstddef>).

C++ 17 introduced it.

Check box size change with CSS

You might want to do this.

input[type=checkbox] {

 -ms-transform: scale(2); /* IE */
 -moz-transform: scale(2); /* FF */
 -webkit-transform: scale(2); /* Safari and Chrome */
 -o-transform: scale(2); /* Opera */
  padding: 10px;
}

Is jQuery $.browser Deprecated?

From the documentation:

The $.browser property is deprecated in jQuery 1.3, and its functionality may be moved to a team-supported plugin in a future release of jQuery.

So, yes, it is deprecated, but your existing implementations will continue to work. If the functionality is removed, it will likely be easily accessible using a plugin.

As to whether there is an alternative... The answer is "yes, probably". It is far, far better to do feature detection using $.support rather than browser detection: detect the actual feature you need, not the browser that provides it. Most important features that vary from browser to browser are detected with that.


Update 16 February 2013: In jQuery 1.9, this feature was removed (docs). It is far better not to use it. If you really, really must use its functionality, you can restore it with the jQuery Migrate plugin.

Why does IE9 switch to compatibility mode on my website?

Works in IE9 documentMode for me.

Without a X-UA-Compatible header/meta to set an explicit documentMode, you'll get a mode based on:

  • whether the user has clicked the ‘compatibility view’ button in that domain before;
  • perhaps also whether this has happened automatically due to some other content on the site causing IE8/9's renderer to crash and fall back to the old renderer;
  • whether the user has opted to put all sites in compatibility view by default;
  • whether IE thinks the site is on your intranet and so defaults to compatibility view;
  • whether the site in question is in Microsoft's own list of websites that require compatibility view.

You can change these settings from ‘Tools -> Compatibility view settings’ from the IE menu. Of course that menu is now sneakily hidden, so you won't see it until you press Alt.

As a site author, if you're confident that your site complies to standards (renders well in other browsers, and uses feature-sniffing to decide what browser workarounds to use), I suggest using:

<meta http-equiv="X-UA-Compatible" content="IE=Edge"/>

or the HTTP header:

X-UA-Compatible: IE=Edge

to get the latest renderer whatever IE version is in use.

Get Unix timestamp with C++

Windows uses a different epoch and time units: see Convert Windows Filetime to second in Unix/Linux

What std::time() returns on Windows is (as yet) unknown to me (;-))

Send text to specific contact programmatically (whatsapp)

This will first search for the specified contact and then open a chat window. And if WhatsApp is not installed then try-catch block handle this.

    String digits = "\\d+";
    String mob_num = "987654321";     
    if (mob_num.matches(digits)) 
            {
        try {
              //linking for whatsapp
              Uri uri = Uri.parse("whatsapp://send?phone=+91" + mob_num);
              Intent i = new Intent(Intent.ACTION_VIEW, uri);
              startActivity(i);
            }
            catch (ActivityNotFoundException e){
                    e.printStackTrace();
                    //if you're in anonymous class pass context like "YourActivity.this"
                    Toast.makeText(this, "WhatsApp not installed.", Toast.LENGTH_SHORT).show();
            }
        }

What is the difference between a deep copy and a shallow copy?

In short, it depends on what points to what. In a shallow copy, object B points to object A's location in memory. In deep copy, all things in object A's memory location get copied to object B's memory location.

This wiki article has a great diagram.

http://en.wikipedia.org/wiki/Object_copy

Google Play Services GCM 9.2.0 asks to "update" back to 9.0.0

Do you have the line

apply plugin: 'com.google.gms.google-services' 

line at the bottom of your app's build.gradle file?

I saw some errors when it was on the top and as it's written here, it should be at the bottom.

Uncompress tar.gz file

Use -C option of tar:

tar zxvf <yourfile>.tar.gz -C /usr/src/

and then, the content of the tar should be in:

/usr/src/<yourfile>

How to create a GUID in Excel?

=CONCATENATE(
    DEC2HEX(RANDBETWEEN(0;4294967295);8);"-";
    DEC2HEX(RANDBETWEEN(0;42949);4);"-";
    DEC2HEX(RANDBETWEEN(0;42949);4);"-";
    DEC2HEX(RANDBETWEEN(0;42949);4);"-";
    DEC2HEX(RANDBETWEEN(0;4294967295);8);
    DEC2HEX(RANDBETWEEN(0;42949);4)
)

How to access random item in list?

Why not[2]:

public static T GetRandom<T>(this List<T> list)
{
     return list[(int)(DateTime.Now.Ticks%list.Count)];
}

jQuery exclude elements with certain class in selector

use this..

$(".content_box a:not('.button')")

SQL Connection Error: System.Data.SqlClient.SqlException (0x80131904)

Check these steps.

  1. go to Sql Server Configuration management->SQL Server network config->protocols for 'servername' and check TCP/IP is enabled.
  2. Open SSMS in run, and check you are able to login to server using specfied username/password and/or using windows authentication.
  3. repeat step 1 for SQL native client config also

Counting the number of elements in array

Best practice of getting length is use length filter returns the number of items of a sequence or mapping, or the length of a string. For example: {{ notcount | length }}

But you can calculate count of elements in for loop. For example:

{% set count = 0 %}
{% for nc in notcount %}
    {% set count = count + 1 %}
{% endfor %}

{{ count }}

This solution helps if you want to calculate count of elements by condition, for example you have a property name inside object and you want to calculate count of objects with not empty names:

{% set countNotEmpty = 0 %}
{% for nc in notcount if nc.name %}
    {% set countNotEmpty = countNotEmpty + 1 %}
{% endfor %}

{{ countNotEmpty }}

Useful links:

How do I create a ListView with rounded corners in Android?

Here is one way of doing it (Thanks to Android Documentation though!):

Add the following into a file (say customshape.xml) and then place it in (res/drawable/customshape.xml)

<?xml version="1.0" encoding="UTF-8"?> 
<shape xmlns:android="http://schemas.android.com/apk/res/android" 
     android:shape="rectangle"> 
     <gradient 
         android:startColor="#SomeGradientBeginColor"
         android:endColor="#SomeGradientEndColor" 
         android:angle="270"/> 

    <corners 
         android:bottomRightRadius="7dp" 
         android:bottomLeftRadius="7dp" 
         android:topLeftRadius="7dp" 
         android:topRightRadius="7dp"/> 
</shape> 

Once you are done with creating this file, just set the background in one of the following ways:

Through Code: listView.setBackgroundResource(R.drawable.customshape);

Through XML, just add the following attribute to the container (ex: LinearLayout or to any fields):

android:background="@drawable/customshape"

Hope someone finds it useful...

Check file uploaded is in csv format

So I ran into this today.

Was attempting to validate an uploaded CSV file's MIME type by looking at $_FILES['upload_file']['type'], but for certain users on various browsers (and not necessarily the same browsers between said users; for instance it worked fine for me in FF but for another user it didn't work on FF) the $_FILES['upload_file']['type'] was coming up as "application/vnd.ms-excel" instead of the expected "text/csv" or "text/plain".

So I resorted to using the (IMHO) much more reliable finfo_* functions something like this:

$acceptable_mime_types = array('text/plain', 'text/csv', 'text/comma-separated-values');

if (!empty($_FILES) && array_key_exists('upload_file', $_FILES) && $_FILES['upload_file']['error'] == UPLOAD_ERR_OK) {
    $tmpf = $_FILES['upload_file']['tmp_name'];

    // Make sure $tmpf is kosher, then:

    $finfo = finfo_open(FILEINFO_MIME_TYPE);
    $mime_type = finfo_file($finfo, $tmpf);

    if (!in_array($mime_type, $acceptable_mime_types)) {
        // Unacceptable mime type.
    }
}

Laravel where on relationship object

The correct syntax to do this on your relations is:

Event::whereHas('participants', function ($query) {
    return $query->where('IDUser', '=', 1);
})->get();

Read more at https://laravel.com/docs/5.8/eloquent-relationships#eager-loading

Delete element in a slice

In golang's wiki it show some tricks for slice, including delete an element from slice.

Link: enter link description here

For example a is the slice which you want to delete the number i element.

a = append(a[:i], a[i+1:]...)

OR

a = a[:i+copy(a[i:], a[i+1:])]

The iOS Simulator deployment targets is set to 7.0, but the range of supported deployment target version for this platform is 8.0 to 12.1

The problem is in your pod files deployment target iOS Version not in your project deployment target iOS Version, so you need to change the deployment iOS version for your pods as well to anything higher than 8.0 to do so open your project workspace and do this:

1- Click on pods.

2- Select each project and target and click on build settings.

3- Under Deployment section change the iOS Deployment Target version to anything more than 8.0 (better to try the same project version).

4- Repeat this for every other project in your pods then run the app.

see the photo for details enter image description here

How do operator.itemgetter() and sort() work?

You are asking a lot of questions that you could answer yourself by reading the documentation, so I'll give you a general advice: read it and experiment in the python shell. You'll see that itemgetter returns a callable:

>>> func = operator.itemgetter(1)
>>> func(a)
['Paul', 22, 'Car Dealer']
>>> func(a[0])
8

To do it in a different way, you can use lambda:

a.sort(key=lambda x: x[1])

And reverse it:

a.sort(key=operator.itemgetter(1), reverse=True)

Sort by more than one column:

a.sort(key=operator.itemgetter(1,2))

See the sorting How To.

How to disable editing of elements in combobox for c#?

Yow can change the DropDownStyle in properties to DropDownList. This will not show the TextBox for filter.

DropDownStyle Property
(Screenshot provided by FUSION CHA0S.)

Longer object length is not a multiple of shorter object length?

Yes, this is something that you should worry about. Check the length of your objects with nrow(). R can auto-replicate objects so that they're the same length if they differ, which means you might be performing operations on mismatched data.

In this case you have an obvious flaw in that your subtracting aggregated data from raw data. These will definitely be of different lengths. I suggest that you merge them as time series (using the dates), then locf(), then do your subtraction. Otherwise merge them by truncating the original dates to the same interval as the aggregated series. Just be very careful that you don't drop observations.

Lastly, as some general advice as you get started: look at the result of your computations to see if they make sense. You might even pull them into a spreadsheet and replicate the results.

Placeholder Mixin SCSS/CSS

To avoid 'Unclosed block: CssSyntaxError' errors being thrown from sass compilers add a ';' to the end of @content.

@mixin placeholder {
   ::-webkit-input-placeholder { @content;}
   :-moz-placeholder           { @content;}
   ::-moz-placeholder          { @content;}
   :-ms-input-placeholder      { @content;}
}

How can I create an object and add attributes to it?

Now you can do (not sure if it's the same answer as evilpie):

MyObject = type('MyObject', (object,), {})
obj = MyObject()
obj.value = 42

The imported project "C:\Microsoft.CSharp.targets" was not found

For errors with Microsoft.WebApplications.targets, you can:

  1. Install Visual Studio 2010 (or the same version as in development machine) in your TFS server.
  2. Copy the “Microsoft.WebApplication.targets” from development machine file to TFS build machine.

Here's the post.

How connect Postgres to localhost server using pgAdmin on Ubuntu?

It helps me:


1. Open the file pg_hba.conf

sudo nano /etc/postgresql/9.x/main/pg_hba.conf

and change this line:

Database administrative login by Unix domain socket
local   all             postgres                                md5

to

Database administrative login by Unix domain socket
local   all             postgres                                trust
  1. Restart the server

    sudo service postgresql restart

  2. Login into psql and set password

    psql -U postgres

ALTER USER postgres with password 'new password';

  1. Again open the file pg_hba.conf and change this line:
Database administrative login by Unix domain socket
    local   all             postgres                                trust

to

    Database administrative login by Unix domain socket
    local   all             postgres                                md5
  1. Restart the server

    sudo service postgresql restart


It works.

enter image description here


Helpful links
1: PostgreSQL (from ubuntu.com)

How to show all rows by default in JQuery DataTable

Use:

$('#example').dataTable({
    aLengthMenu: [
        [25, 50, 100, 200, -1],
        [25, 50, 100, 200, "All"]
    ],
    iDisplayLength: -1
});

Or if using 1.10+

$('#example').dataTable({
    paging: false
});

The option you should use is iDisplayLength:

$('#adminProducts').dataTable({
  'iDisplayLength': 100
});

$('#table').DataTable({
   "lengthMenu": [ [5, 10, 25, 50, -1], [5, 10, 25, 50, "All"] ]
});

It will Load by default all entries.

$('#example').dataTable({
    aLengthMenu: [
        [25, 50, 100, 200, -1],
        [25, 50, 100, 200, "All"]
    ],
    iDisplayLength: -1
});

Or if using 1.10+

$('#example').dataTable({
    paging: false
});

If you want to load by default 25 not all do this.

$('#example').dataTable({
    aLengthMenu: [
        [25, 50, 100, 200, -1],
        [25, 50, 100, 200, "All"]
    ],
});

Where can I download Eclipse Android bundle?

You don't actually need the bundle as the ADT can be used with just any latest Eclipse IDE.


1. Make sure you have JDK installed.

  1. Download latest eclipse.

  2. Download latest ADT plugin ADT-XX.X.X.zip. As of this answer the current version is ADT-23.0.7.zip (More versions at http://developer.android.com/tools/sdk/eclipse-adt.html)

  3. Open Eclipse and follow the following steps:

    • Open Help > Install New Software > Add > Archive
    • Navigate to where you downloaded your ADT plugin and select it.
    • Check Developer Tools, click Next, accept any licenses and Finish
  4. After restarting Eclipse, if you are not able to open a layout file go to step 4 but instead of selecting archive add https://dl-ssl.google.com/android/eclipse/ in the Location: textbox. Press Ok, update the ADT and restart Eclipse. Close and reopen the layout files and you'll be good to go.

  5. Run the Android SDK Manager to update its components.


EDIT: The ADT plugin has long since been deprecated. For more information visit this link:

https://developer.android.com/studio/tools/sdk/eclipse-adt.html

"if not exist" command in batch file

if not exist "%USERPROFILE%\.qgis-custom\" (
    mkdir "%USERPROFILE%\.qgis-custom" 2>nul
    if not errorlevel 1 (
        xcopy "%OSGEO4W_ROOT%\qgisconfig" "%USERPROFILE%\.qgis-custom" /s /v /e
    )
)

You have it almost done. The logic is correct, just some little changes.

This code checks for the existence of the folder (see the ending backslash, just to differentiate a folder from a file with the same name).

If it does not exist then it is created and creation status is checked. If a file with the same name exists or you have no rights to create the folder, it will fail.

If everyting is ok, files are copied.

All paths are quoted to avoid problems with spaces.

It can be simplified (just less code, it does not mean it is better). Another option is to always try to create the folder. If there are no errors, then copy the files

mkdir "%USERPROFILE%\.qgis-custom" 2>nul 
if not errorlevel 1 (
    xcopy "%OSGEO4W_ROOT%\qgisconfig" "%USERPROFILE%\.qgis-custom" /s /v /e
)

In both code samples, files are not copied if the folder is not being created during the script execution.

EDITED - As dbenham comments, the same code can be written as a single line

md "%USERPROFILE%\.qgis-custom" 2>nul && xcopy "%OSGEO4W_ROOT%\qgisconfig" "%USERPROFILE%\.qgis-custom" /s /v /e

The code after the && will only be executed if the previous command does not set errorlevel. If mkdir fails, xcopy is not executed.

Center form submit buttons HTML / CSS

http://jsfiddle.net/SebastianPataneMasuelli/rJxQC/

i just wrapped a div around them and made it align center. then you don't need any css on the buttons to center them.

<div class="buttonHolder">
  <input value="Search" title="Search" type="submit" id="btn_s"> 
  <input value="I'm Feeling Lucky" title="I'm Feeling Lucky" name="lucky" type="submit" id="btn_i">
</div>

.buttonHolder{ text-align: center; }

How to pass query parameters with a routerLink

queryParams

queryParams is another input of routerLink where they can be passed like

<a [routerLink]="['../']" [queryParams]="{prop: 'xxx'}">Somewhere</a>

fragment

<a [routerLink]="['../']" [queryParams]="{prop: 'xxx'}" [fragment]="yyy">Somewhere</a>

routerLinkActiveOptions

To also get routes active class set on parent routes:

[routerLinkActiveOptions]="{ exact: false }"

To pass query parameters to this.router.navigate(...) use

let navigationExtras: NavigationExtras = {
  queryParams: { 'session_id': sessionId },
  fragment: 'anchor'
};

// Navigate to the login page with extras
this.router.navigate(['/login'], navigationExtras);

See also https://angular.io/guide/router#query-parameters-and-fragments

ldap_bind: Invalid Credentials (49)

I don't see an obvious problem with the above.

It's possible your ldap.conf is being overridden, but the command-line options will take precedence, ldapsearch will ignore BINDDN in the main ldap.conf, so the only parameter that could be wrong is the URI. (The order is ETCDIR/ldap.conf then ~/ldaprc or ~/.ldaprc and then ldaprc in the current directory, though there environment variables which can influence this too, see man ldapconf.)

Try an explicit URI:

ldapsearch -x -W -D 'cn=Manager,dc=example,dc=com' -b "" -s base -H ldap://localhost

or prevent defaults with:

LDAPNOINIT=1 ldapsearch -x -W -D 'cn=Manager,dc=example,dc=com' -b "" -s base

If that doesn't work, then some troubleshooting (you'll probably need the full path to the slapd binary for these):

  • make sure your slapd.conf is being used and is correct (as root)

    slapd -T test -f slapd.conf -d 65535

    You may have a left-over or default slapd.d configuration directory which takes preference over your slapd.conf (unless you specify your config explicitly with -f, slapd.conf is officially deprecated in OpenLDAP-2.4). If you don't get several pages of output then your binaries were built without debug support.

  • stop OpenLDAP, then manually start slapd in a separate terminal/console with debug enabled (as root, ^C to quit)

    slapd -h ldap://localhost -d 481

    then retry the search and see if you can spot the problem (there will be a lot of schema noise in the start of the output unfortunately). (Note: running slapd without the -u/-g options can change file ownerships which can cause problems, you should usually use those options, probably -u ldap -g ldap )

  • if debug is enabled, then try also

    ldapsearch -v -d 63 -W -D 'cn=Manager,dc=example,dc=com' -b "" -s base

How can I set a dynamic model name in AngularJS?

Or you can use

<select [(ngModel)]="Answers[''+question.Name+'']" ng-options="option for option in question.Options">
        </select>

How to annotate MYSQL autoincrement field with JPA annotations

Using MySQL, only this approach was working for me:

@Id @GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;

The other 2 approaches stated by Pascal in his answer were not working for me.

How to remove the underline for anchors(links)?

Sometime it will override by some rendering UI CSS. Better to use:

a.className {
    text-decoration: none !important;
}

JSON.stringify doesn't work with normal Javascript array

I posted a fix for this here

You can use this function to modify JSON.stringify to encode arrays, just post it near the beginning of your script (check the link above for more detail):

// Upgrade for JSON.stringify, updated to allow arrays
(function(){
    // Convert array to object
    var convArrToObj = function(array){
        var thisEleObj = new Object();
        if(typeof array == "object"){
            for(var i in array){
                var thisEle = convArrToObj(array[i]);
                thisEleObj[i] = thisEle;
            }
        }else {
            thisEleObj = array;
        }
        return thisEleObj;
    };
    var oldJSONStringify = JSON.stringify;
    JSON.stringify = function(input){
        if(oldJSONStringify(input) == '[]')
            return oldJSONStringify(convArrToObj(input));
        else
            return oldJSONStringify(input);
    };
})();

Key value pairs using JSON

JSON (= JavaScript Object Notation), is a lightweight and fast mechanism to convert Javascript objects into a string and vice versa.

Since Javascripts objects consists of key/value pairs its very easy to use and access JSON that way.

So if we have an object:

var myObj = {
    foo:   'bar',
    base:  'ball',
    deep:  {
       java:  'script'
    }
};

We can convert that into a string by calling window.JSON.stringify(myObj); with the result of "{"foo":"bar","base":"ball","deep":{"java":"script"}}".

The other way around, we would call window.JSON.parse("a json string like the above");.

JSON.parse() returns a javascript object/array on success.

alert(myObj.deep.java);  // 'script'

window.JSON is not natively available in all browser. Some "older" browser need a little javascript plugin which offers the above mentioned functionality. Check http://www.json.org for further information.

In laymans terms, what does 'static' mean in Java?

The static keyword can be used in several different ways in Java and in almost all cases it is a modifier which means the thing it is modifying is usable without an enclosing object instance.

Java is an object oriented language and by default most code that you write requires an instance of the object to be used.

public class SomeObject {
    public int someField;
    public void someMethod() { };
    public Class SomeInnerClass { };
}

In order to use someField, someMethod, or SomeInnerClass I have to first create an instance of SomeObject.

public class SomeOtherObject {
    public void doSomeStuff() {
        SomeObject anInstance = new SomeObject();
        anInstance.someField = 7;
        anInstance.someMethod();
        //Non-static inner classes are usually not created outside of the
        //class instance so you don't normally see this syntax
        SomeInnerClass blah = anInstance.new SomeInnerClass();
    }
}

If I declare those things static then they do not require an enclosing instance.

public class SomeObjectWithStaticStuff {
    public static int someField;
    public static void someMethod() { };
    public static Class SomeInnerClass { };
}

public class SomeOtherObject {
    public void doSomeStuff() {
        SomeObjectWithStaticStuff.someField = 7;
        SomeObjectWithStaticStuff.someMethod();
        SomeObjectWithStaticStuff.SomeInnerClass blah = new SomeObjectWithStaticStuff.SomeInnerClass();
        //Or you can also do this if your imports are correct
        SomeInnerClass blah2 = new SomeInnerClass();
    }
}

Declaring something static has several implications.

First, there can only ever one value of a static field throughout your entire application.

public class SomeOtherObject {
    public void doSomeStuff() {
        //Two objects, two different values
        SomeObject instanceOne = new SomeObject();
        SomeObject instanceTwo = new SomeObject();
        instanceOne.someField = 7;
        instanceTwo.someField = 10;
        //Static object, only ever one value
        SomeObjectWithStaticStuff.someField = 7;
        SomeObjectWithStaticStuff.someField = 10; //Redefines the above set
    }
}

The second issue is that static methods and inner classes cannot access fields in the enclosing object (since there isn't one).

public class SomeObjectWithStaticStuff {
    private int nonStaticField;
    private void nonStaticMethod() { };

    public static void someStaticMethod() {
        nonStaticField = 7; //Not allowed
        this.nonStaticField = 7; //Not allowed, can never use *this* in static
        nonStaticMethod(); //Not allowed
        super.someSuperMethod(); //Not allowed, can never use *super* in static
    }

    public static class SomeStaticInnerClass {

        public void doStuff() {
            someStaticField = 7; //Not allowed
            nonStaticMethod(); //Not allowed
            someStaticMethod(); //This is ok
        }

    }
}

The static keyword can also be applied to inner interfaces, annotations, and enums.

public class SomeObject {
    public static interface SomeInterface { };
    public static @interface SomeAnnotation { };
    public static enum SomeEnum { };
}

In all of these cases the keyword is redundant and has no effect. Interfaces, annotations, and enums are static by default because they never have a relationship to an inner class.

This just describes what they keyword does. It does not describe whether the use of the keyword is a bad idea or not. That can be covered in more detail in other questions such as Is using a lot of static methods a bad thing?

There are also a few less common uses of the keyword static. There are static imports which allow you to use static types (including interfaces, annotations, and enums not redundantly marked static) unqualified.

//SomeStaticThing.java
public class SomeStaticThing {
    public static int StaticCounterOne = 0;
}

//SomeOtherStaticThing.java
public class SomeOtherStaticThing {
    public static int StaticCounterTwo = 0;
}

//SomeOtherClass.java
import static some.package.SomeStaticThing.*;
import some.package.SomeOtherStaticThing.*;

public class SomeOtherClass {
    public void doStuff() {
        StaticCounterOne++; //Ok
        StaticCounterTwo++; //Not ok
        SomeOtherStaticThing.StaticCounterTwo++; //Ok
    }
}

Lastly, there are static initializers which are blocks of code that are run when the class is first loaded (which is usually just before a class is instantiated for the first time in an application) and (like static methods) cannot access non-static fields or methods.

public class SomeObject {

    private static int x;

    static {
        x = 7;
    }
}

Unable to load DLL 'SQLite.Interop.dll'

When you get in this state, try performing a Rebuild-All. If this fixes the problem, you may have the same issue I had.

Some background (my understanding):

  • SQLite has 1 managed assembly (System.Data.SQLite.dll) and several platform specific assemblies (SQLite.Interop.dll). When installing SQLite with Nuget, Nuget will add the platform specific assemblies to your project (within several folders: \x86, \x64), and configures these dlls to "Copy Always".

  • Upon load, the managed assembly will search for platform specific assemblies inside the \x86 and \x64 folders. You can see more on that here. The exception is this managed assembly attempting to find the relevant (SQLite.Interop.dll) inside these folders (and failing).

My Scenario:

I have 2 projects in my solution; a WPF app, and a class library. The WPF app references the class library, and the class library references SQLite (installed via Nuget).

The issue for me was when I modify only the WPF app, VS attempts to do a partial rebuild (realizing that the dependent dll hasn't changed). Somewhere in this process, VS cleans the content of the \x86 and \x64 folders (blowing away SQLite.Interop.dll). When I do a full Rebuild-All, VS copies the folders and their contents correctly.

My Solution:

To fix this, I ended up adding a Post-Build process using xcopy to force copying the \x86 and \x64 folders from the class library to my WPF project \bin directory.

Alternatively, you could do fancier things with the build configuration / output directories.

Can't specify the 'async' modifier on the 'Main' method of a console app

class Program
{
     public static EventHandler AsyncHandler;
     static void Main(string[] args)
     {
        AsyncHandler+= async (sender, eventArgs) => { await AsyncMain(); };
        AsyncHandler?.Invoke(null, null);
     }

     private async Task AsyncMain()
     {
        //Your Async Code
     }
}

How can jQuery deferred be used?

Another use that I've been putting to good purpose is fetching data from multiple sources. In the example below, I'm fetching multiple, independent JSON schema objects used in an existing application for validation between a client and a REST server. In this case, I don't want the browser-side application to start loading data before it has all the schemas loaded. $.when.apply().then() is perfect for this. Thank to Raynos for pointers on using then(fn1, fn2) to monitor for error conditions.

fetch_sources = function (schema_urls) {
    var fetch_one = function (url) {
            return $.ajax({
                url: url,
                data: {},
                contentType: "application/json; charset=utf-8",
                dataType: "json",
            });
        }
    return $.map(schema_urls, fetch_one);
}

var promises = fetch_sources(data['schemas']);
$.when.apply(null, promises).then(

function () {
    var schemas = $.map(arguments, function (a) {
        return a[0]
    });
    start_application(schemas);
}, function () {
    console.log("FAIL", this, arguments);
});     

Can I embed a custom font in an iPhone application?

Yes, you can include custom fonts. Refer to the documentation on UIFont, specifically, the fontWithName:size: method.

1) Make sure you include the font in your resources folder.

2) The "name" of the font is not necessarily the filename.

3) Make sure you have the legal right to use that font. By including it in your app, you're also distributing it, and you need to have the right to do that.

Error in data frame undefined columns selected

Are you meaning?

data2 <- data1[good,]

With

data1[good]

you're selecting columns in a wrong way (using a logical vector of complete rows).

Consider that parameter pollutant is not used; is it a column name that you want to extract? if so it should be something like

data2 <- data1[good, pollutant]

Furthermore consider that you have to rbind the data.frames inside the for loop, otherwise you get only the last data.frame (its completed.cases)

And last but not least, i'd prefer generating filenames eg with

id <- 1:322
paste0( directory, "/", gsub(" ", "0", sprintf("%3d",id)), ".csv")

A little modified chunk of ?sprintf

The string fmt (in our case "%3d") contains normal characters, which are passed through to the output string, and also conversion specifications which operate on the arguments provided through .... The allowed conversion specifications start with a % and end with one of the letters in the set aAdifeEgGosxX%. These letters denote the following types:

  • d: integer

Eg a more general example

    sprintf("I am %10d years old", 25)
[1] "I am         25 years old"
          ^^^^^^^^^^
          |        |
          1       10

Full examples of using pySerial package

http://web.archive.org/web/20131107050923/http://www.roman10.net/serial-port-communication-in-python/comment-page-1/

#!/usr/bin/python

import serial, time
#initialization and open the port

#possible timeout values:
#    1. None: wait forever, block call
#    2. 0: non-blocking mode, return immediately
#    3. x, x is bigger than 0, float allowed, timeout block call

ser = serial.Serial()
#ser.port = "/dev/ttyUSB0"
ser.port = "/dev/ttyUSB7"
#ser.port = "/dev/ttyS2"
ser.baudrate = 9600
ser.bytesize = serial.EIGHTBITS #number of bits per bytes
ser.parity = serial.PARITY_NONE #set parity check: no parity
ser.stopbits = serial.STOPBITS_ONE #number of stop bits
#ser.timeout = None          #block read
ser.timeout = 1            #non-block read
#ser.timeout = 2              #timeout block read
ser.xonxoff = False     #disable software flow control
ser.rtscts = False     #disable hardware (RTS/CTS) flow control
ser.dsrdtr = False       #disable hardware (DSR/DTR) flow control
ser.writeTimeout = 2     #timeout for write

try: 
    ser.open()
except Exception, e:
    print "error open serial port: " + str(e)
    exit()

if ser.isOpen():

    try:
        ser.flushInput() #flush input buffer, discarding all its contents
        ser.flushOutput()#flush output buffer, aborting current output 
                 #and discard all that is in buffer

        #write data
        ser.write("AT+CSQ")
        print("write data: AT+CSQ")

       time.sleep(0.5)  #give the serial port sometime to receive the data

       numOfLines = 0

       while True:
          response = ser.readline()
          print("read data: " + response)

        numOfLines = numOfLines + 1

        if (numOfLines >= 5):
            break

        ser.close()
    except Exception, e1:
        print "error communicating...: " + str(e1)

else:
    print "cannot open serial port "

Call a stored procedure with another in Oracle

Sure, you just call it from within the SP, there's no special syntax.

Ex:

   PROCEDURE some_sp
   AS
   BEGIN
      some_other_sp('parm1', 10, 20.42);
   END;

If the procedure is in a different schema than the one the executing procedure is in, you need to prefix it with schema name.

   PROCEDURE some_sp
   AS
   BEGIN
      other_schema.some_other_sp('parm1', 10, 20.42);
   END;

How to avoid "RuntimeError: dictionary changed size during iteration" error?

You cannot iterate through a dictionary while its changing during for loop. Make a casting to list and iterate over that list, it works for me.

    for key in list(d):
        if not d[key]: 
            d.pop(key)

IOError: [Errno 32] Broken pipe: Python

The problem is due to SIGPIPE handling. You can solve this problem using the following code:

from signal import signal, SIGPIPE, SIG_DFL
signal(SIGPIPE,SIG_DFL) 

See here for background on this solution. Better answer here.

Is there a way to make AngularJS load partials in the beginning and not at when needed?

You can pass $state to your controller and then when the page loads and calls the getter in the controller you call $state.go('index') or whatever partial you want to load. Done.

what does the __file__ variable mean/do?

When a module is loaded from a file in Python, __file__ is set to its path. You can then use that with other functions to find the directory that the file is located in.

Taking your examples one at a time:

A = os.path.join(os.path.dirname(__file__), '..')
# A is the parent directory of the directory where program resides.

B = os.path.dirname(os.path.realpath(__file__))
# B is the canonicalised (?) directory where the program resides.

C = os.path.abspath(os.path.dirname(__file__))
# C is the absolute path of the directory where the program resides.

You can see the various values returned from these here:

import os
print(__file__)
print(os.path.join(os.path.dirname(__file__), '..'))
print(os.path.dirname(os.path.realpath(__file__)))
print(os.path.abspath(os.path.dirname(__file__)))

and make sure you run it from different locations (such as ./text.py, ~/python/text.py and so forth) to see what difference that makes.


I just want to address some confusion first. __file__ is not a wildcard it is an attribute. Double underscore attributes and methods are considered to be "special" by convention and serve a special purpose.

http://docs.python.org/reference/datamodel.html shows many of the special methods and attributes, if not all of them.

In this case __file__ is an attribute of a module (a module object). In Python a .py file is a module. So import amodule will have an attribute of __file__ which means different things under difference circumstances.

Taken from the docs:

__file__ is the pathname of the file from which the module was loaded, if it was loaded from a file. The __file__ attribute is not present for C modules that are statically linked into the interpreter; for extension modules loaded dynamically from a shared library, it is the pathname of the shared library file.

In your case the module is accessing it's own __file__ attribute in the global namespace.

To see this in action try:

# file: test.py

print globals()
print __file__

And run:

python test.py

{'__builtins__': <module '__builtin__' (built-in)>, '__name__': '__main__', '__file__':
 'test_print__file__.py', '__doc__': None, '__package__': None}
test_print__file__.py

How to set top position using jquery

You could also do

   var x = $('#element').height();   // or any changing value

   $('selector').css({'top' : x + 'px'});

OR

You can use directly

$('#element').css( "height" )

The difference between .css( "height" ) and .height() is that the latter returns a unit-less pixel value (for example, 400) while the former returns a value with units intact (for example, 400px). The .height() method is recommended when an element's height needs to be used in a mathematical calculation. jquery doc

Django Cookies, how can I set them?

Anyone interested in doing this should read the documentation of the Django Sessions framework. It stores a session ID in the user's cookies, but maps all the cookies-like data to your database. This is an improvement on the typical cookies-based workflow for HTTP requests.

Here is an example with a Django view ...

def homepage(request):

    request.session.setdefault('how_many_visits', 0)
    request.session['how_many_visits'] += 1

    print(request.session['how_many_visits'])

    return render(request, 'home.html', {})

If you keep visiting the page over and over, you'll see the value start incrementing up from 1 until you clear your cookies, visit on a new browser, go incognito, or do anything else that sidesteps Django's Session ID cookie.

How to add one column into existing SQL Table

Its work perfectly

ALTER TABLE `products` ADD `LastUpdate` varchar(200) NULL;

But if you want more precise in table then you can try AFTER.

ALTER TABLE `products` ADD `LastUpdate` varchar(200) NULL AFTER `column_name`;

It will add LastUpdate column after specified column name (column_name).

MySQL set current date in a DATETIME field on insert

Since MySQL 5.6.X you can do this:

ALTER TABLE `schema`.`users` 
CHANGE COLUMN `created` `created` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP ;

That way your column will be updated with the current timestamp when a new row is inserted, or updated.

If you're using MySQL Workbench, you can just put CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP in the DEFAULT value field, like so:

enter image description here

http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-5.html

"element.dispatchEvent is not a function" js error caught in firebug of FF3.0

check for this by calling the library jquery after the noconflict.js or that this calling more than once jquery library after the noconflict.js

Iterate through every file in one directory

As others have said, Dir::foreach is a good option here. However, note that Dir::foreach and Dir::entries will always include . and .. (the current and parent directories). You will generally not want to work on them, so you can use Dir::each_child or Dir::children (as suggested by ma11hew28) or do something like this:

Dir.foreach('/path/to/dir') do |filename|
  next if filename == '.' or filename == '..'
  # Do work on the remaining files & directories
end

Dir::foreach and Dir::entries (as well as Dir::each_child and Dir::children) also include hidden files & directories. Often this is what you want, but if it isn't, you need to do something to skip over them.

Alternatively, you might want to look into Dir::glob which provides simple wildcard matching:

Dir.glob('/path/to/dir/*.rb') do |rb_filename|
  # Do work on files & directories ending in .rb
end

Why is 2 * (i * i) faster than 2 * i * i in Java?

The two methods of adding do generate slightly different byte code:

  17: iconst_2
  18: iload         4
  20: iload         4
  22: imul
  23: imul
  24: iadd

For 2 * (i * i) vs:

  17: iconst_2
  18: iload         4
  20: imul
  21: iload         4
  23: imul
  24: iadd

For 2 * i * i.

And when using a JMH benchmark like this:

@Warmup(iterations = 5, batchSize = 1)
@Measurement(iterations = 5, batchSize = 1)
@Fork(1)
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.MILLISECONDS)
@State(Scope.Benchmark)
public class MyBenchmark {

    @Benchmark
    public int noBrackets() {
        int n = 0;
        for (int i = 0; i < 1000000000; i++) {
            n += 2 * i * i;
        }
        return n;
    }

    @Benchmark
    public int brackets() {
        int n = 0;
        for (int i = 0; i < 1000000000; i++) {
            n += 2 * (i * i);
        }
        return n;
    }

}

The difference is clear:

# JMH version: 1.21
# VM version: JDK 11, Java HotSpot(TM) 64-Bit Server VM, 11+28
# VM options: <none>

Benchmark                      (n)  Mode  Cnt    Score    Error  Units
MyBenchmark.brackets    1000000000  avgt    5  380.889 ± 58.011  ms/op
MyBenchmark.noBrackets  1000000000  avgt    5  512.464 ± 11.098  ms/op

What you observe is correct, and not just an anomaly of your benchmarking style (i.e. no warmup, see How do I write a correct micro-benchmark in Java?)

Running again with Graal:

# JMH version: 1.21
# VM version: JDK 11, Java HotSpot(TM) 64-Bit Server VM, 11+28
# VM options: -XX:+UnlockExperimentalVMOptions -XX:+EnableJVMCI -XX:+UseJVMCICompiler

Benchmark                      (n)  Mode  Cnt    Score    Error  Units
MyBenchmark.brackets    1000000000  avgt    5  335.100 ± 23.085  ms/op
MyBenchmark.noBrackets  1000000000  avgt    5  331.163 ± 50.670  ms/op

You see that the results are much closer, which makes sense, since Graal is an overall better performing, more modern, compiler.

So this is really just up to how well the JIT compiler is able to optimize a particular piece of code, and doesn't necessarily have a logical reason to it.

Get current working directory in a Qt application

Just tested and QDir::currentPath() does return the path from which I called my executable.

And a symlink does not "exist". If you are executing an exe from that path you are effectively executing it from the path the symlink points to.

Maven: Failed to retrieve plugin descriptor error

In my case, it was not worknig even after passing the proxy credentails.

Mistake was - forgot to remove the comment line.

<!-- proxy
 | Specification for one proxy, to be used in connecting to the network.

<proxy>
  <id>optional</id>
  <active>true</active>
  <protocol>http</protocol>
  <username>345325</username>
  <password>dfgasdfg</password>
  <host>proxy.abc.com</host>
  <port>8080</port>
  <nonProxyHosts>proxy.abc.com</nonProxyHosts>
</proxy>
|-->    ----------REMOVE THIS LINE AND CLOSE It above <proxy> tag

Extract substring in Bash

shell cut - print specific range of characters or given part from a string

#method1) using bash

 str=2020-08-08T07:40:00.000Z
 echo ${str:11:8}

#method2) using cut

 str=2020-08-08T07:40:00.000Z
 cut -c12-19 <<< $str

#method3) when working with awk

 str=2020-08-08T07:40:00.000Z
 awk '{time=gensub(/.{11}(.{8}).*/,"\\1","g",$1); print time}' <<< $str

Where to find 64 bit version of chromedriver.exe for Selenium WebDriver?

You will find newest version of the chromedriver here: http://chromedriver.storage.googleapis.com/index.html - there is a 64bit version for linux.

How to make sure that string is valid JSON using JSON.NET

Through Code:

Your best bet is to use parse inside a try-catch and catch exception in case of failed parsing. (I am not aware of any TryParse method).

(Using JSON.Net)

Simplest way would be to Parse the string using JToken.Parse, and also to check if the string starts with { or [ and ends with } or ] respectively (added from this answer):

private static bool IsValidJson(string strInput)
{
    if (string.IsNullOrWhiteSpace(strInput)) { return false;}
    strInput = strInput.Trim();
    if ((strInput.StartsWith("{") && strInput.EndsWith("}")) || //For object
        (strInput.StartsWith("[") && strInput.EndsWith("]"))) //For array
    {
        try
        {
            var obj = JToken.Parse(strInput);
            return true;
        }
        catch (JsonReaderException jex)
        {
            //Exception in parsing json
            Console.WriteLine(jex.Message);
            return false;
        }
        catch (Exception ex) //some other exception
        {
            Console.WriteLine(ex.ToString());
            return false;
        }
    }
    else
    {
        return false;
    }
}

The reason to add checks for { or [ etc was based on the fact that JToken.Parse would parse the values such as "1234" or "'a string'" as a valid token. The other option could be to use both JObject.Parse and JArray.Parse in parsing and see if anyone of them succeeds, but I believe checking for {} and [] should be easier. (Thanks @RhinoDevel for pointing it out)

Without JSON.Net

You can utilize .Net framework 4.5 System.Json namespace ,like:

string jsonString = "someString";
try
{
    var tmpObj = JsonValue.Parse(jsonString);
}
catch (FormatException fex)
{
    //Invalid json format
    Console.WriteLine(fex);
}
catch (Exception ex) //some other exception
{
    Console.WriteLine(ex.ToString());
}

(But, you have to install System.Json through Nuget package manager using command: PM> Install-Package System.Json -Version 4.0.20126.16343 on Package Manager Console) (taken from here)

Non-Code way:

Usually, when there is a small json string and you are trying to find a mistake in the json string, then I personally prefer to use available on-line tools. What I usually do is:

Bulk Insert Correctly Quoted CSV File in SQL Server

Make sure you have enabled TextQualified option and set it to be ".

Interview Question: Merge two sorted singly linked lists without creating new nodes

This could be done without creating the extra node, with just an another Node reference passing to the parameters (Node temp).

private static Node mergeTwoLists(Node nodeList1, Node nodeList2, Node temp) {
    if(nodeList1 == null) return nodeList2;
    if(nodeList2 == null) return nodeList1;

    if(nodeList1.data <= nodeList2.data){
        temp = nodeList1;
        temp.next = mergeTwoLists(nodeList1.next, nodeList2, temp);
    }
    else{
        temp = nodeList2;
        temp.next = mergeTwoLists(nodeList1, nodeList2.next, temp);
    }
    return temp;
}

How to convert a Date to a formatted string in VB.net?

Dim timeFormat As String = "yyyy-MM-dd HH:mm:ss"
objBL.date = Convert.ToDateTime(txtDate.Value).ToString(timeFormat)

Binary Data Posting with curl

You don't need --header "Content-Length: $LENGTH".

curl --request POST --data-binary "@template_entry.xml" $URL

Note that GET request does not support content body widely.

Also remember that POST request have 2 different coding schema. This is first form:

  $ nc -l -p 6666 &
  $ curl  --request POST --data-binary "@README" http://localhost:6666

POST / HTTP/1.1
User-Agent: curl/7.21.0 (x86_64-pc-linux-gnu) libcurl/7.21.0 OpenSSL/0.9.8o zlib/1.2.3.4 libidn/1.15 libssh2/1.2.6
Host: localhost:6666
Accept: */*
Content-Length: 9309
Content-Type: application/x-www-form-urlencoded
Expect: 100-continue

.. -*- mode: rst; coding: cp1251; fill-column: 80 -*-
.. rst2html.py README README.html
.. contents::

You probably request this:

-F/--form name=content
           (HTTP) This lets curl emulate a filled-in form in
              which a user has pressed the submit button. This
              causes curl to POST data using the Content- Type
              multipart/form-data according to RFC2388. This
              enables uploading of binary files etc. To force the
              'content' part to be a file, prefix the file name
              with an @ sign. To just get the content part from a
              file, prefix the file name with the symbol <. The
              difference between @ and < is then that @ makes a
              file get attached in the post as a file upload,
              while the < makes a text field and just get the
              contents for that text field from a file.

<meta charset="utf-8"> vs <meta http-equiv="Content-Type">

I would recommend doing it like this to keep things in line with HTML5.

<meta charset="UTF-8">

EG:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
</body>
</html>

How to get the data-id attribute?

I use $.data - http://api.jquery.com/jquery.data/

//Set value 7 to data-id 
$.data(this, 'id', 7);

//Get value from data-id
alert( $(this).data("id") ); // => outputs 7

Posting JSON data via jQuery to ASP .NET MVC 4 controller action

I think you'll find your answer if you refer to this post: Deserialize JSON into C# dynamic object?

There are various ways of achieving what you want here. The System.Web.Helpers.Json approach (a few answers down) seems to be the simplest.

What is the best way to create a string array in python?

The error message says it all: strs[sum-1] is a tuple, not a string. If you show more of your code someone will probably be able to help you. Without that we can only guess.

Find unique lines

You could also print out the unique value in "file" using the cat command by piping to sort and uniq

cat file | sort | uniq -u

Palindrome check in Javascript

25x faster than the standard answer

function isPalindrome(s,i) {
 return (i=i||0)<0||i>=s.length>>1||s[i]==s[s.length-1-i]&&isPalindrome(s,++i);
}

use like:

isPalindrome('racecar');

as it defines "i" itself

Fiddle: http://jsfiddle.net/namcx0yf/9/

This is ~25 times faster than the standard answer below.

function checkPalindrome(str) {
  return str == str.split('').reverse().join('');
}

Fiddle: http://jsfiddle.net/t0zfjfab/2/

View console for performance results.

Although the solution is difficult to read and maintain, I would recommend understanding it to demonstrate non-branching with recursion and bit shifting to impress your next interviewer.

explained

The || and && are used for control flow like "if" "else". If something left of || is true, it just exits with true. If something is false left of || it must continue. If something left of && is false, it exits as false, if something left of a && is true, it must continue. This is considered "non-branching" as it does not need if-else interupts, rather its just evaluated.

1. Used an initializer not requiring "i" to be defined as an argument. Assigns "i" to itself if defined, otherwise initialize to 0. Always is false so next OR condition is always evaluated.

(i = i || 0) < 0

2. Checks if "i" went half way but skips checking middle odd char. Bit shifted here is like division by 2 but to lowest even neighbor division by 2 result. If true then assumes palindrome since its already done. If false evaluates next OR condition.

i >= s.length >> 1

3. Compares from beginning char and end char according to "i" eventually to meet as neighbors or neighbor to middle char. If false exits and assumes NOT palindrome. If true continues on to next AND condition.

s[i] == s[s.length-1-i]

4. Calls itself again for recursion passing the original string as "s". Since "i" is defined for sure at this point, it is pre-incremented to continue checking the string's position. Returns boolean value indicating if palindrome.

isPalindrome(s,++i)

BUT...

A simple for loop is still about twice as fast as my fancy answer (aka KISS principle)

function fastestIsPalindrome(str) {
  var len = Math.floor(str.length / 2);
  for (var i = 0; i < len; i++)
    if (str[i] !== str[str.length - i - 1])
      return false;
  return true;
}

http://jsfiddle.net/6L953awz/1/

Flexbox: center horizontally and vertically

If you need to center a text in a link this will do the trick:

_x000D_
_x000D_
div {_x000D_
  display: flex;_x000D_
_x000D_
  width: 200px;_x000D_
  height: 80px;_x000D_
  background-color: yellow;_x000D_
}_x000D_
_x000D_
a {_x000D_
  display: flex;_x000D_
  align-items: center;_x000D_
  justify-content: center;_x000D_
  text-align: center; /* only important for multiple lines */_x000D_
_x000D_
  padding: 0 20px;_x000D_
  background-color: silver;_x000D_
  border: 2px solid blue;_x000D_
}
_x000D_
<div>_x000D_
  <a href="#">text</a>_x000D_
  <a href="#">text with two lines</a>_x000D_
</div>
_x000D_
_x000D_
_x000D_

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

So you want the code to the pin it button without installing the button? If so just paste this code in the place of the url of the page you're pinning from. It should function as a pin it button without the button.

javascript:void((function(){var%20e=document.createElement('script');e.setAttribute('type','text/javascript');e.setAttribute('charset','UTF-8');e.setAttribute('src','http://assets.pinterest.com/js/pinmarklet.js?r='+Math.random()*99999999);document.body.appendChild(e)})());

Python convert object to float

I eventually used:

weather["Temp"] = weather["Temp"].convert_objects(convert_numeric=True)

It worked just fine, except that I got the following message.

C:\ProgramData\Anaconda3\lib\site-packages\ipykernel_launcher.py:3: FutureWarning:
convert_objects is deprecated.  Use the data-type specific converters pd.to_datetime, pd.to_timedelta and pd.to_numeric.

Missing Push Notification Entitlement

Yes, that's the cause of the App Store rejection. If your ad-hoc provisioning profile has the aps-environment key, it means your app is configured correctly in the Apple Provisioning Portal. All you need to do is delete the App Store distribution profile on your local machine, then re-download and install the distribution profile from the Provisioning Portal. This new one should contain the aps-environment key.

Finding modified date of a file/folder

PowerShell code to find all document library files modified from last 2 days.

$web = Get-SPWeb -Identity http://siteName:9090/ 
        $list = $web.GetList("http://siteName:9090/Style Library/")
        $folderquery =  New-Object Microsoft.SharePoint.SPQuery  
        $foldercamlQuery =  
        '<Where>   <Eq> 
                <FieldRef Name="ContentType" />  <Value Type="text">Folder</Value> 
            </Eq> </Where>' 
        $folderquery.Query = $foldercamlQuery 
        $folders = $list.GetItems($folderquery) 
        foreach($folderItem in $folders) 
        { 
            $folder = $folderItem.Folder
            if($folder.ItemCount -gt 0){ 
            Write-Host " find Item count " $folder.ItemCount
                $oldest = $null
                $files = $folder.Files

                $date = (Get-Date).AddDays(-2).ToString(“MM/dd/yyyy”)
                foreach ($file in $files){ 
                    if($file.Item["Modified"]-Ge $date)
                    {
                        Write-Host "Last 2 days modified folder name:"   $folder   " File Name: "  $file.Item["Name"]   " Date of midified: "  $file.Item["Modified"] 
                    } 
                } 
            } 
            else
             { 
                Write-Warning "$folder['Name'] is empty" 
            } 
        }

Bootstrap 3 Slide in Menu / Navbar on Mobile

Without Plugin, we can do this; bootstrap multi-level responsive menu for mobile phone with slide toggle for mobile:

_x000D_
_x000D_
$('[data-toggle="slide-collapse"]').on('click', function() {_x000D_
  $navMenuCont = $($(this).data('target'));_x000D_
  $navMenuCont.animate({_x000D_
    'width': 'toggle'_x000D_
  }, 350);_x000D_
  $(".menu-overlay").fadeIn(500);_x000D_
});_x000D_
_x000D_
$(".menu-overlay").click(function(event) {_x000D_
  $(".navbar-toggle").trigger("click");_x000D_
  $(".menu-overlay").fadeOut(500);_x000D_
});_x000D_
_x000D_
// if ($(window).width() >= 767) {_x000D_
//     $('ul.nav li.dropdown').hover(function() {_x000D_
//         $(this).find('>.dropdown-menu').stop(true, true).delay(200).fadeIn(500);_x000D_
//     }, function() {_x000D_
//         $(this).find('>.dropdown-menu').stop(true, true).delay(200).fadeOut(500);_x000D_
//     });_x000D_
_x000D_
//     $('ul.nav li.dropdown-submenu').hover(function() {_x000D_
//         $(this).find('>.dropdown-menu').stop(true, true).delay(200).fadeIn(500);_x000D_
//     }, function() {_x000D_
//         $(this).find('>.dropdown-menu').stop(true, true).delay(200).fadeOut(500);_x000D_
//     });_x000D_
_x000D_
_x000D_
//     $('ul.dropdown-menu [data-toggle=dropdown]').on('click', function(event) {_x000D_
//         event.preventDefault();_x000D_
//         event.stopPropagation();_x000D_
//         $(this).parent().siblings().removeClass('open');_x000D_
//         $(this).parent().toggleClass('open');_x000D_
//         $('b', this).toggleClass("caret caret-up");_x000D_
//     });_x000D_
// }_x000D_
_x000D_
// $(window).resize(function() {_x000D_
//     if( $(this).width() >= 767) {_x000D_
//         $('ul.nav li.dropdown').hover(function() {_x000D_
//             $(this).find('>.dropdown-menu').stop(true, true).delay(200).fadeIn(500);_x000D_
//         }, function() {_x000D_
//             $(this).find('>.dropdown-menu').stop(true, true).delay(200).fadeOut(500);_x000D_
//         });_x000D_
//     }_x000D_
// });_x000D_
_x000D_
var windowWidth = $(window).width();_x000D_
if (windowWidth > 767) {_x000D_
  // $('ul.dropdown-menu [data-toggle=dropdown]').on('click', function(event) {_x000D_
  //     event.preventDefault();_x000D_
  //     event.stopPropagation();_x000D_
  //     $(this).parent().siblings().removeClass('open');_x000D_
  //     $(this).parent().toggleClass('open');_x000D_
  //     $('b', this).toggleClass("caret caret-up");_x000D_
  // });_x000D_
_x000D_
  $('ul.nav li.dropdown').hover(function() {_x000D_
    $(this).find('>.dropdown-menu').stop(true, true).delay(200).fadeIn(500);_x000D_
  }, function() {_x000D_
    $(this).find('>.dropdown-menu').stop(true, true).delay(200).fadeOut(500);_x000D_
  });_x000D_
_x000D_
  $('ul.nav li.dropdown-submenu').hover(function() {_x000D_
    $(this).find('>.dropdown-menu').stop(true, true).delay(200).fadeIn(500);_x000D_
  }, function() {_x000D_
    $(this).find('>.dropdown-menu').stop(true, true).delay(200).fadeOut(500);_x000D_
  });_x000D_
_x000D_
_x000D_
  $('ul.dropdown-menu [data-toggle=dropdown]').on('click', function(event) {_x000D_
    event.preventDefault();_x000D_
    event.stopPropagation();_x000D_
    $(this).parent().siblings().removeClass('open');_x000D_
    $(this).parent().toggleClass('open');_x000D_
    // $('b', this).toggleClass("caret caret-up");_x000D_
  });_x000D_
}_x000D_
if (windowWidth < 767) {_x000D_
  $('ul.dropdown-menu [data-toggle=dropdown]').on('click', function(event) {_x000D_
    event.preventDefault();_x000D_
    event.stopPropagation();_x000D_
    $(this).parent().siblings().removeClass('open');_x000D_
    $(this).parent().toggleClass('open');_x000D_
    // $('b', this).toggleClass("caret caret-up");_x000D_
  });_x000D_
}_x000D_
_x000D_
// $('.dropdown a').append('Some text');
_x000D_
@media only screen and (max-width: 767px) {_x000D_
  #slide-navbar-collapse {_x000D_
    position: fixed;_x000D_
    top: 0;_x000D_
    left: 15px;_x000D_
    z-index: 999999;_x000D_
    width: 280px;_x000D_
    height: 100%;_x000D_
    background-color: #f9f9f9;_x000D_
    overflow: auto;_x000D_
    bottom: 0;_x000D_
    max-height: inherit;_x000D_
  }_x000D_
  .menu-overlay {_x000D_
    display: none;_x000D_
    background-color: #000;_x000D_
    bottom: 0;_x000D_
    left: 0;_x000D_
    opacity: 0.5;_x000D_
    filter: alpha(opacity=50);_x000D_
    /* IE7 & 8 */_x000D_
    position: fixed;_x000D_
    right: 0;_x000D_
    top: 0;_x000D_
    z-index: 49;_x000D_
  }_x000D_
  .navbar-fixed-top {_x000D_
    position: initial !important;_x000D_
  }_x000D_
  .navbar-nav .open .dropdown-menu {_x000D_
    background-color: #ffffff;_x000D_
  }_x000D_
  ul.nav.navbar-nav li {_x000D_
    border-bottom: 1px solid #eee;_x000D_
  }_x000D_
  .navbar-nav .open .dropdown-menu .dropdown-header,_x000D_
  .navbar-nav .open .dropdown-menu>li>a {_x000D_
    padding: 10px 20px 10px 15px;_x000D_
  }_x000D_
}_x000D_
_x000D_
.dropdown-submenu {_x000D_
  position: relative;_x000D_
}_x000D_
_x000D_
.dropdown-submenu .dropdown-menu {_x000D_
  top: 0;_x000D_
  left: 100%;_x000D_
  margin-top: -1px;_x000D_
}_x000D_
_x000D_
li.dropdown a {_x000D_
  display: block;_x000D_
  position: relative;_x000D_
}_x000D_
_x000D_
li.dropdown>a:before {_x000D_
  content: "\f107";_x000D_
  font-family: FontAwesome;_x000D_
  position: absolute;_x000D_
  right: 6px;_x000D_
  top: 5px;_x000D_
  font-size: 15px;_x000D_
}_x000D_
_x000D_
li.dropdown-submenu>a:before {_x000D_
  content: "\f107";_x000D_
  font-family: FontAwesome;_x000D_
  position: absolute;_x000D_
  right: 6px;_x000D_
  top: 10px;_x000D_
  font-size: 15px;_x000D_
}_x000D_
_x000D_
ul.dropdown-menu li {_x000D_
  border-bottom: 1px solid #eee;_x000D_
}_x000D_
_x000D_
.dropdown-menu {_x000D_
  padding: 0px;_x000D_
  margin: 0px;_x000D_
  border: none !important;_x000D_
}_x000D_
_x000D_
li.dropdown.open {_x000D_
  border-bottom: 0px !important;_x000D_
}_x000D_
_x000D_
li.dropdown-submenu.open {_x000D_
  border-bottom: 0px !important;_x000D_
}_x000D_
_x000D_
li.dropdown-submenu>a {_x000D_
  font-weight: bold !important;_x000D_
}_x000D_
_x000D_
li.dropdown>a {_x000D_
  font-weight: bold !important;_x000D_
}_x000D_
_x000D_
.navbar-default .navbar-nav>li>a {_x000D_
  font-weight: bold !important;_x000D_
  padding: 10px 20px 10px 15px;_x000D_
}_x000D_
_x000D_
li.dropdown>a:before {_x000D_
  content: "\f107";_x000D_
  font-family: FontAwesome;_x000D_
  position: absolute;_x000D_
  right: 6px;_x000D_
  top: 9px;_x000D_
  font-size: 15px;_x000D_
}_x000D_
_x000D_
@media (min-width: 767px) {_x000D_
  li.dropdown-submenu>a {_x000D_
    padding: 10px 20px 10px 15px;_x000D_
  }_x000D_
  li.dropdown>a:before {_x000D_
    content: "\f107";_x000D_
    font-family: FontAwesome;_x000D_
    position: absolute;_x000D_
    right: 3px;_x000D_
    top: 12px;_x000D_
    font-size: 15px;_x000D_
  }_x000D_
}
_x000D_
<!DOCTYPE html>_x000D_
<html lang="en">_x000D_
_x000D_
  <head>_x000D_
    <title>Bootstrap Example</title>_x000D_
    <meta charset="utf-8">_x000D_
    <meta name="viewport" content="width=device-width, initial-scale=1">_x000D_
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">_x000D_
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>_x000D_
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>_x000D_
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">_x000D_
_x000D_
  </head>_x000D_
_x000D_
  <body>_x000D_
    <nav class="navbar navbar-default navbar-fixed-top">_x000D_
      <div class="container-fluid">_x000D_
        <!-- Brand and toggle get grouped for better mobile display -->_x000D_
        <div class="navbar-header">_x000D_
          <button type="button" class="navbar-toggle collapsed" data-toggle="slide-collapse" data-target="#slide-navbar-collapse" aria-expanded="false">_x000D_
                    <span class="sr-only">Toggle navigation</span>_x000D_
                    <span class="icon-bar"></span>_x000D_
                    <span class="icon-bar"></span>_x000D_
                    <span class="icon-bar"></span>_x000D_
                </button>_x000D_
          <a class="navbar-brand" href="#">Brand</a>_x000D_
        </div>_x000D_
        <!-- Collect the nav links, forms, and other content for toggling -->_x000D_
        <div class="collapse navbar-collapse" id="slide-navbar-collapse">_x000D_
          <ul class="nav navbar-nav">_x000D_
            <li><a href="#">Link <span class="sr-only">(current)</span></a></li>_x000D_
            <li><a href="#">Link</a></li>_x000D_
            <li class="dropdown">_x000D_
              <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Dropdown</span></a>_x000D_
              <ul class="dropdown-menu">_x000D_
                <li><a href="#">Action</a></li>_x000D_
                <li><a href="#">Another action</a></li>_x000D_
                <li><a href="#">Something else here</a></li>_x000D_
                <li><a href="#">Separated link</a></li>_x000D_
                <li><a href="#">One more separated link</a></li>_x000D_
                <li class="dropdown-submenu">_x000D_
                  <a href="#" data-toggle="dropdown">SubMenu 1</span></a>_x000D_
                  <ul class="dropdown-menu">_x000D_
                    <li><a href="#">3rd level dropdown</a></li>_x000D_
                    <li><a href="#">3rd level dropdown</a></li>_x000D_
                    <li><a href="#">3rd level dropdown</a></li>_x000D_
                    <li><a href="#">3rd level dropdown</a></li>_x000D_
                    <li><a href="#">3rd level dropdown</a></li>_x000D_
                    <li class="dropdown-submenu">_x000D_
                      <a href="#" data-toggle="dropdown">SubMenu 2</span></a>_x000D_
                      <ul class="dropdown-menu">_x000D_
                        <li><a href="#">3rd level dropdown</a></li>_x000D_
                        <li><a href="#">3rd level dropdown</a></li>_x000D_
                        <li><a href="#">3rd level dropdown</a></li>_x000D_
                        <li><a href="#">3rd level dropdown</a></li>_x000D_
                        <li><a href="#">3rd level dropdown</a></li>_x000D_
                      </ul>_x000D_
                    </li>_x000D_
                  </ul>_x000D_
                </li>_x000D_
              </ul>_x000D_
            </li>_x000D_
            <li><a href="#">Link</a></li>_x000D_
          </ul>_x000D_
          <ul class="nav navbar-nav navbar-right">_x000D_
            <li><a href="#">Link</a></li>_x000D_
            <li class="dropdown">_x000D_
              <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Dropdown</span></a>_x000D_
              <ul class="dropdown-menu">_x000D_
                <li><a href="#">Action</a></li>_x000D_
                <li><a href="#">Another action</a></li>_x000D_
                <li><a href="#">Something else here</a></li>_x000D_
                <li><a href="#">Separated link</a></li>_x000D_
              </ul>_x000D_
            </li>_x000D_
          </ul>_x000D_
        </div>_x000D_
        <!-- /.navbar-collapse -->_x000D_
      </div>_x000D_
      <!-- /.container-fluid -->_x000D_
    </nav>_x000D_
    <div class="menu-overlay"></div>_x000D_
    <div class="col-md-12">_x000D_
      <h1>Resize the window to see the result</h1>_x000D_
      <p>_x000D_
        Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus non bibendum sem, et sodales massa. Proin quis velit vel nisl imperdiet rhoncus vitae id tortor. Praesent blandit tellus in enim sollicitudin rutrum. Integer ullamcorper, augue ut tristique_x000D_
        ultrices, augue magna placerat ex, ac varius mauris ante sed dui. Fusce ullamcorper vulputate magna, a malesuada nunc pellentesque sit amet. Donec posuere placerat erat, sed ornare enim aliquam vitae. Nullam pellentesque auctor augue, vel commodo_x000D_
        dolor porta ac. Sed libero eros, fringilla ac lorem in, blandit scelerisque lorem. Suspendisse iaculis justo velit, sit amet fringilla velit ornare a. Sed consectetur quam eget ipsum luctus bibendum. Ut nisi lectus, viverra vitae ipsum sit amet,_x000D_
        condimentum condimentum neque. In maximus suscipit eros ut eleifend. Donec venenatis mauris nulla, ac bibendum metus bibendum vel._x000D_
      </p>_x000D_
      <p>_x000D_
        Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus non bibendum sem, et sodales massa. Proin quis velit vel nisl imperdiet rhoncus vitae id tortor. Praesent blandit tellus in enim sollicitudin rutrum. Integer ullamcorper, augue ut tristique_x000D_
        ultrices, augue magna placerat ex, ac varius mauris ante sed dui. Fusce ullamcorper vulputate magna, a malesuada nunc pellentesque sit amet. Donec posuere placerat erat, sed ornare enim aliquam vitae. Nullam pellentesque auctor augue, vel commodo_x000D_
        dolor porta ac. Sed libero eros, fringilla ac lorem in, blandit scelerisque lorem. Suspendisse iaculis justo velit, sit amet fringilla velit ornare a. Sed consectetur quam eget ipsum luctus bibendum. Ut nisi lectus, viverra vitae ipsum sit amet,_x000D_
        condimentum condimentum neque. In maximus suscipit eros ut eleifend. Donec venenatis mauris nulla, ac bibendum metus bibendum vel._x000D_
      </p>_x000D_
      <p>_x000D_
        Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus non bibendum sem, et sodales massa. Proin quis velit vel nisl imperdiet rhoncus vitae id tortor. Praesent blandit tellus in enim sollicitudin rutrum. Integer ullamcorper, augue ut tristique_x000D_
        ultrices, augue magna placerat ex, ac varius mauris ante sed dui. Fusce ullamcorper vulputate magna, a malesuada nunc pellentesque sit amet. Donec posuere placerat erat, sed ornare enim aliquam vitae. Nullam pellentesque auctor augue, vel commodo_x000D_
        dolor porta ac. Sed libero eros, fringilla ac lorem in, blandit scelerisque lorem. Suspendisse iaculis justo velit, sit amet fringilla velit ornare a. Sed consectetur quam eget ipsum luctus bibendum. Ut nisi lectus, viverra vitae ipsum sit amet,_x000D_
        condimentum condimentum neque. In maximus suscipit eros ut eleifend. Donec venenatis mauris nulla, ac bibendum metus bibendum vel._x000D_
      </p>_x000D_
      <p>_x000D_
        Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus non bibendum sem, et sodales massa. Proin quis velit vel nisl imperdiet rhoncus vitae id tortor. Praesent blandit tellus in enim sollicitudin rutrum. Integer ullamcorper, augue ut tristique_x000D_
        ultrices, augue magna placerat ex, ac varius mauris ante sed dui. Fusce ullamcorper vulputate magna, a malesuada nunc pellentesque sit amet. Donec posuere placerat erat, sed ornare enim aliquam vitae. Nullam pellentesque auctor augue, vel commodo_x000D_
        dolor porta ac. Sed libero eros, fringilla ac lorem in, blandit scelerisque lorem. Suspendisse iaculis justo velit, sit amet fringilla velit ornare a. Sed consectetur quam eget ipsum luctus bibendum. Ut nisi lectus, viverra vitae ipsum sit amet,_x000D_
        condimentum condimentum neque. In maximus suscipit eros ut eleifend. Donec venenatis mauris nulla, ac bibendum metus bibendum vel._x000D_
      </p>_x000D_
      <p>_x000D_
        Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus non bibendum sem, et sodales massa. Proin quis velit vel nisl imperdiet rhoncus vitae id tortor. Praesent blandit tellus in enim sollicitudin rutrum. Integer ullamcorper, augue ut tristique_x000D_
        ultrices, augue magna placerat ex, ac varius mauris ante sed dui. Fusce ullamcorper vulputate magna, a malesuada nunc pellentesque sit amet. Donec posuere placerat erat, sed ornare enim aliquam vitae. Nullam pellentesque auctor augue, vel commodo_x000D_
        dolor porta ac. Sed libero eros, fringilla ac lorem in, blandit scelerisque lorem. Suspendisse iaculis justo velit, sit amet fringilla velit ornare a. Sed consectetur quam eget ipsum luctus bibendum. Ut nisi lectus, viverra vitae ipsum sit amet,_x000D_
        condimentum condimentum neque. In maximus suscipit eros ut eleifend. Donec venenatis mauris nulla, ac bibendum metus bibendum vel._x000D_
      </p>_x000D_
    </div>_x000D_
_x000D_
  </body>_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_

Reference JS fiddle

In Maven how to exclude resources from the generated jar?

When I create an executable jar with dependencies (using this guide), all properties files are packaged into that jar too. How to stop it from happening? Thanks.

Properties files from where? Your main jar? Dependencies?

In the former case, putting resources under src/test/resources as suggested is probably the most straight forward and simplest option.

In the later case, you'll have to create a custom assembly descriptor with special excludes/exclude in the unpackOptions.

Java random numbers using a seed

If you're giving the same seed, that's normal. That's an important feature allowing tests.

Check this to understand pseudo random generation and seeds:

Pseudorandom number generator

A pseudorandom number generator (PRNG), also known as a deterministic random bit generator DRBG, is an algorithm for generating a sequence of numbers that approximates the properties of random numbers. The sequence is not truly random in that it is completely determined by a relatively small set of initial values, called the PRNG's state, which includes a truly random seed.

If you want to have different sequences (the usual case when not tuning or debugging the algorithm), you should call the zero argument constructor which uses the nanoTime to try to get a different seed every time. This Random instance should of course be kept outside of your method.

Your code should probably be like this:

private Random generator = new Random();
double randomGenerator() {
    return generator.nextDouble()*0.5;
}

Java - Access is denied java.io.FileNotFoundException

You need to set permission for the user controls .

  1. Goto C:\Program Files\
  2. Right click java folder, click properties. Select the security tab.
  3. There, click on "Edit" button, which will pop up PERMISSIONS FOR JAVA window.
  4. Click on Add, which will pop up a new window. In that, in the "Enter object name" box, Enter your user account name, and click okay(if already exist, skip this step).
  5. Now in "PERMISSIONS OF JAVA" window, you will see several clickable options like CREATOR OWNER, SYSTEM, among them is your username. Click on it, and check mark the FULL CONTROL option in Permissions for sub window.
  6. Finally, Hit apply and okay.

Showing Thumbnail for link in WhatsApp || og:image meta-tag doesn't work

In reply to https://stackoverflow.com/a/35785393/1518500

Try the updated version for schema.org

<span itemprop="image" itemscope itemtype="http://schema.org/ImageObject"> 
 <link itemprop="url" href="imgurlHere">
 <meta itemprop="width" content="1200">
 <meta itemprop="height" content="800">
</span>

or using the json-ld format from google

<script type="application/ld+json">
 {
"@context": "http://schema.org/",
"@type": "ImageObject",
 "url": "ImgURLhere",
    "height": 800,
    "width": 1200

 }
 </script>

Adding subscribers to a list using Mailchimp's API v3

These are good answers but detached from a full answer as to how you would get a form to send data and handle that response. This will demonstrate how to add a member to a list with v3.0 of the API from an HTML page via jquery .ajax().

In Mailchimp:

  1. Acquire your API Key and List ID
  2. Make sure you setup your list and what custom fields you want to use with it. In this case, I've set up zipcode as a custom field in the list BEFORE I did the API call.
  3. Check out the API docs on adding members to lists. We are using the create method which requires the use of HTTP POST requests. There are other options in here that require PUT if you want to be able to modify/delete subs.

HTML:

<form id="pfb-signup-submission" method="post">
  <div class="sign-up-group">
    <input type="text" name="pfb-signup" id="pfb-signup-box-fname" class="pfb-signup-box" placeholder="First Name">
    <input type="text" name="pfb-signup" id="pfb-signup-box-lname" class="pfb-signup-box" placeholder="Last Name">
    <input type="email" name="pfb-signup" id="pfb-signup-box-email" class="pfb-signup-box" placeholder="[email protected]">
    <input type="text" name="pfb-signup" id="pfb-signup-box-zip" class="pfb-signup-box" placeholder="Zip Code">
  </div>
  <input type="submit" class="submit-button" value="Sign-up" id="pfb-signup-button"></a>
  <div id="pfb-signup-result"></div>
</form>

Key things:

  1. Give your <form> a unique ID and don't forget the method="post" attribute so the form works.
  2. Note the last line #signup-result is where you will deposit the feedback from the PHP script.

PHP:

<?php
  /*
   * Add a 'member' to a 'list' via mailchimp API v3.x
   * @ http://developer.mailchimp.com/documentation/mailchimp/reference/lists/members/#create-post_lists_list_id_members
   *
   * ================
   * BACKGROUND
   * Typical use case is that this code would get run by an .ajax() jQuery call or possibly a form action
   * The live data you need will get transferred via the global $_POST variable
   * That data must be put into an array with keys that match the mailchimp endpoints, check the above link for those
   * You also need to include your API key and list ID for this to work.
   * You'll just have to go get those and type them in here, see README.md
   * ================
   */

  // Set API Key and list ID to add a subscriber
  $api_key = 'your-api-key-here';
  $list_id = 'your-list-id-here';

  /* ================
   * DESTINATION URL
   * Note: your API URL has a location subdomain at the front of the URL string
   * It can vary depending on where you are in the world
   * To determine yours, check the last 3 digits of your API key
   * ================
   */
  $url = 'https://us5.api.mailchimp.com/3.0/lists/' . $list_id . '/members/';

  /* ================
   * DATA SETUP
   * Encode data into a format that the add subscriber mailchimp end point is looking for
   * Must include 'email_address' and 'status'
   * Statuses: pending = they get an email; subscribed = they don't get an email
   * Custom fields go into the 'merge_fields' as another array
   * More here: http://developer.mailchimp.com/documentation/mailchimp/reference/lists/members/#create-post_lists_list_id_members
   * ================
   */
  $pfb_data = array(
    'email_address' => $_POST['emailname'],
    'status'        => 'pending',
    'merge_fields'  => array(
      'FNAME'       => $_POST['firstname'],
      'LNAME'       => $_POST['lastname'],
      'ZIPCODE'     => $_POST['zipcode']
    ),
  );

  // Encode the data
  $encoded_pfb_data = json_encode($pfb_data);

  // Setup cURL sequence
  $ch = curl_init();

  /* ================
   * cURL OPTIONS
   * The tricky one here is the _USERPWD - this is how you transfer the API key over
   * _RETURNTRANSFER allows us to get the response into a variable which is nice
   * This example just POSTs, we don't edit/modify - just a simple add to a list
   * _POSTFIELDS does the heavy lifting
   * _SSL_VERIFYPEER should probably be set but I didn't do it here
   * ================
   */
  curl_setopt($ch, CURLOPT_URL, $url);
  curl_setopt($ch, CURLOPT_USERPWD, 'user:' . $api_key);
  curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json'));
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
  curl_setopt($ch, CURLOPT_TIMEOUT, 10);
  curl_setopt($ch, CURLOPT_POST, 1);
  curl_setopt($ch, CURLOPT_POSTFIELDS, $encoded_pfb_data);
  curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

  $results = curl_exec($ch); // store response
  $response = curl_getinfo($ch, CURLINFO_HTTP_CODE); // get HTTP CODE
  $errors = curl_error($ch); // store errors

  curl_close($ch);

  // Returns info back to jQuery .ajax or just outputs onto the page

  $results = array(
    'results' => $result_info,
    'response' => $response,
    'errors' => $errors
  );

  // Sends data back to the page OR the ajax() in your JS
  echo json_encode($results);
?>

Key things:

  1. CURLOPT_USERPWD handles the API key and Mailchimp doesn't really show you how to do this.
  2. CURLOPT_RETURNTRANSFER gives us the response in such a way that we can send it back into the HTML page with the .ajax() success handler.
  3. Use json_encodeon the data you received.

JS:

// Signup form submission
$('#pfb-signup-submission').submit(function(event) {
  event.preventDefault();

  // Get data from form and store it
  var pfbSignupFNAME = $('#pfb-signup-box-fname').val();
  var pfbSignupLNAME = $('#pfb-signup-box-lname').val();
  var pfbSignupEMAIL = $('#pfb-signup-box-email').val();
  var pfbSignupZIP = $('#pfb-signup-box-zip').val();

  // Create JSON variable of retreived data
  var pfbSignupData = {
    'firstname': pfbSignupFNAME,
    'lastname': pfbSignupLNAME,
    'email': pfbSignupEMAIL,
    'zipcode': pfbSignupZIP
  };

  // Send data to PHP script via .ajax() of jQuery
  $.ajax({
    type: 'POST',
    dataType: 'json',
    url: 'mailchimp-signup.php',
    data: pfbSignupData,
    success: function (results) {
      $('#pfb-signup-box-fname').hide();
      $('#pfb-signup-box-lname').hide();
      $('#pfb-signup-box-email').hide();
      $('#pfb-signup-box-zip').hide();
      $('#pfb-signup-result').text('Thanks for adding yourself to the email list. We will be in touch.');
      console.log(results);
    },
    error: function (results) {
      $('#pfb-signup-result').html('<p>Sorry but we were unable to add you into the email list.</p>');
      console.log(results);
    }
  });
});

Key things:

  1. JSON data is VERY touchy on transfer. Here, I am putting it into an array and it looks easy. If you are having problems, it is likely because of how your JSON data is structured. Check this out!
  2. The keys for your JSON data will become what you reference in the PHP _POST global variable. In this case it will be _POST['email'], _POST['firstname'], etc. But you could name them whatever you want - just remember what you name the keys of the data part of your JSON transfer is how you access them in PHP.
  3. This obviously requires jQuery ;)

JUNIT Test class in Eclipse - java.lang.ClassNotFoundException

In "Package Explorer" view, Right click your test class, then "Build Path">>"Include", it should be OK.

Remove Style on Element

You can edit style with pure Javascript. No library needed, supported by all browsers except IE where you need to set to '' instead of null (see comments).

var element = document.getElementById('sample_id');

element.style.width = null;
element.style.height = null;

For more information, you can refer to HTMLElement.style documentation on MDN.

How can I use Python to get the system hostname?

What about :

import platform

h = platform.uname()[1]

Actually you may want to have a look to all the result in platform.uname()

Spring data JPA query with parameter properties

You can try something like this:

public interface PersonRepository extends CrudRepository<Person, Long> {
       @Query("select p from Person AS p"
       + " ,Name AS n"  
       + " where p.forename = n.forename "
       + " and p.surname = n.surname"
       + " and n = :name")
       Set<Person>findByName(@Param("name") Name name);
    }

What is the difference between an abstract function and a virtual function?

An abstract function cannot have functionality. You're basically saying, any child class MUST give their own version of this method, however it's too general to even try to implement in the parent class.

A virtual function, is basically saying look, here's the functionality that may or may not be good enough for the child class. So if it is good enough, use this method, if not, then override me, and provide your own functionality.

Converting a pointer into an integer

  1. #include <stdint.h>
  2. Use uintptr_t standard type defined in the included standard header file.

Sequence contains no matching element

From the MSDN library:

The First<TSource>(IEnumerable<TSource>) method throws an exception if source contains no elements. To instead return a default value when the source sequence is empty, use the FirstOrDefault method.

What's the difference between "Request Payload" vs "Form Data" as seen in Chrome dev tools Network tab

In Chrome, request with 'Content-Type:application/json' shows as Request PayedLoad and sends data as json object.

But request with 'Content-Type:application/x-www-form-urlencoded' shows Form Data and sends data as Key:Value Pair, so if you have array of object in one key it flats that key's value:

{ Id: 1, 
name:'john', 
phones:[{title:'home',number:111111,...},
        {title:'office',number:22222,...}]
}

sends

{ Id: 1, 
name:'john', 
phones:[object object]
phones:[object object]
}

Add items in array angular 4

Yes there is a way to do it.

First declare a class.

//anyfile.ts
export class Custom
{
  name: string, 
  empoloyeeID: number
}

Then in your component import the class

import {Custom} from '../path/to/anyfile.ts'
.....
export class FormComponent implements OnInit {
 name: string;
 empoloyeeID : number;
 empList: Array<Custom> = [];
 constructor() {

 }

 ngOnInit() {
 }
 onEmpCreate(){
   //console.log(this.name,this.empoloyeeID);
   let customObj = new Custom();
   customObj.name = "something";
   customObj.employeeId = 12; 
   this.empList.push(customObj);
   this.name ="";
   this.empoloyeeID = 0; 
 }
}

Another way would be to interfaces read the documentation once - https://www.typescriptlang.org/docs/handbook/interfaces.html

Also checkout this question, it is very interesting - When to use Interface and Model in TypeScript / Angular2

HTML 5 Favicon - Support?

The answers provided (at the time of this post) are link only answers so I thought I would summarize the links into an answer and what I will be using.

When working to create Cross Browser Favicons (including touch icons) there are several things to consider.

The first (of course) is Internet Explorer. IE does not support PNG favicons until version 11. So our first line is a conditional comment for favicons in IE 9 and below:

<!--[if IE]><link rel="shortcut icon" href="path/to/favicon.ico"><![endif]-->

To cover the uses of the icon create it at 32x32 pixels. Notice the rel="shortcut icon" for IE to recognize the icon it needs the word shortcut which is not standard. Also we wrap the .ico favicon in a IE conditional comment because Chrome and Safari will use the .ico file if it is present, despite other options available, not what we would like.

The above covers IE up to IE 9. IE 11 accepts PNG favicons, however, IE 10 does not. Also IE 10 does not read conditional comments thus IE 10 won't show a favicon. With IE 11 and Edge available I don't see IE 10 in widespread use, so I ignore this browser.

For the rest of the browsers we are going to use the standard way to cite a favicon:

<link rel="icon" href="path/to/favicon.png">

This icon should be 196x196 pixels in size to cover all devices that may use this icon.

To cover touch icons on mobile devices we are going to use Apple's proprietary way to cite a touch icon:

<link rel="apple-touch-icon-precomposed" href="apple-touch-icon-precomposed.png">

Using rel="apple-touch-icon-precomposed" will not apply the reflective shine when bookmarked on iOS. To have iOS apply the shine use rel="apple-touch-icon". This icon should be sized to 180x180 pixels as that is the current size recommend by Apple for the latest iPhones and iPads. I have read Blackberry will also use rel="apple-touch-icon-precomposed".

As a note: Chrome for Android states:

The apple-touch-* are deprecated, and will be supported only for a short time. (Written as of beta for m31 of Chrome).

Custom Tiles for IE 11+ on Windows 8.1+

IE 11+ on Windows 8.1+ does offer a way to create pinned tiles for your site.

Microsoft recommends creating a few tiles at the following size:

Small: 128 x 128

Medium: 270 x 270

Wide: 558 x 270

Large: 558 x 558

These should be transparent images as we will define a color background next.

Once these images are created you should create an xml file called browserconfig.xml with the following code:

<?xml version="1.0" encoding="utf-8"?>
<browserconfig>
  <msapplication>
    <tile>
      <square70x70logo src="images/smalltile.png"/>
      <square150x150logo src="images/mediumtile.png"/>
      <wide310x150logo src="images/widetile.png"/>
      <square310x310logo src="images/largetile.png"/>
      <TileColor>#009900</TileColor>
    </tile>
  </msapplication>
</browserconfig>

Save this xml file in the root of your site. When a site is pinned IE will look for this file. If you want to name the xml file something different or have it in a different location add this meta tag to the head:

<meta name="msapplication-config" content="path-to-browserconfig/custom-name.xml" />

For additional information on IE 11+ custom tiles and using the XML file visit Microsoft's website.

Putting it all together:

To put it all together the above code would look like this:

<!-- For IE 9 and below. ICO should be 32x32 pixels in size -->
<!--[if IE]><link rel="shortcut icon" href="path/to/favicon.ico"><![endif]-->

<!-- Touch Icons - iOS and Android 2.1+ 180x180 pixels in size. --> 
<link rel="apple-touch-icon-precomposed" href="apple-touch-icon-precomposed.png">

<!-- Firefox, Chrome, Safari, IE 11+ and Opera. 196x196 pixels in size. -->
<link rel="icon" href="path/to/favicon.png">

Windows Phone Live Tiles

If a user is using a Windows Phone they can pin a website to the start screen of their phone. Unfortunately, when they do this it displays a screenshot of your phone, not a favicon (not even the MS specific code referenced above). To make a "Live Tile" for Windows Phone Users for your website one must use the following code:

Here are detailed instructions from Microsoft but here is a synopsis:

Step 1

Create a square image for your website, to support hi-res screens create it at 768x768 pixels in size.

Step 2

Add a hidden overlay of this image. Here is example code from Microsoft:

<div id="TileOverlay" onclick="ToggleTileOverlay()" style='background-color: Highlight; height: 100%; width: 100%; top: 0px; left: 0px; position: fixed; color: black; visibility: hidden'>
  <img src="customtile.png" width="320" height="320" />
  <div style='margin-top: 40px'>
     Add text/graphic asking user to pin to start using the menu...
  </div>
</div>

Step 3

You then can add thew following line to add a pin to start link:

<a href="javascript:ToggleTileOverlay()">Pin this site to your start screen</a>

Microsoft recommends that you detect windows phone and only show that link to those users since it won't work for other users.

Step 4

Next you add some JS to toggle the overlay visibility

<script>
function ToggleTileOverlay() {
 var newVisibility =     (document.getElementById('TileOverlay').style.visibility == 'visible') ? 'hidden' : 'visible';
 document.getElementById('TileOverlay').style.visibility =    newVisibility;
}
</script>

Note on Sizes

I am using one size as every browser will scale down the image as necessary. I could add more HTML to specify multiple sizes if desired for those with a lower bandwidth but I am already compressing the PNG files heavily using TinyPNG and I find this unnecessary for my purposes. Also, according to philippe_b's answer Chrome and Firefox have bugs that cause the browser to load all sizes of icons. Using one large icon may be better than multiple smaller ones because of this.

Further Reading

For those who would like more details see the links below:

css with background image without repeating the image

This is all you need:

background-repeat: no-repeat;

Remove Sub String by using Python

import re
re.sub('<.*?>', '', string)
"i think mabe 124 + but I don't have a big experience it just how I see it in my eyes fun stuff"

The re.sub function takes a regular expresion and replace all the matches in the string with the second parameter. In this case, we are searching for all tags ('<.*?>') and replacing them with nothing ('').

The ? is used in re for non-greedy searches.

More about the re module.

Find if a textbox is disabled or not using jquery

 if($("element_selector").attr('disabled') || $("element_selector").prop('disabled'))
 {

    // code when element is disabled

  }

How to reenable event.preventDefault?

You can re-activate the actions by adding

this.delegateEvents();  // Re-activates the events for all the buttons

If you add it to the render function of a backbone js view, then you can use event.preventDefault() as required.

How to change root logging level programmatically for logback

I think you can use MDC to change logging level programmatically. The code below is an example to change logging level on current thread. This approach does not create dependency to logback implementation (SLF4J API contains MDC).

<configuration>
  <turboFilter class="ch.qos.logback.classic.turbo.DynamicThresholdFilter">
    <Key>LOG_LEVEL</Key>
    <DefaultThreshold>DEBUG</DefaultThreshold>
    <MDCValueLevelPair>
      <value>TRACE</value>
      <level>TRACE</level>
    </MDCValueLevelPair>
    <MDCValueLevelPair>
      <value>DEBUG</value>
      <level>DEBUG</level>
    </MDCValueLevelPair>
    <MDCValueLevelPair>
      <value>INFO</value>
      <level>INFO</level>
    </MDCValueLevelPair>
    <MDCValueLevelPair>
      <value>WARN</value>
      <level>WARN</level>
    </MDCValueLevelPair>
    <MDCValueLevelPair>
      <value>ERROR</value>
      <level>ERROR</level>
    </MDCValueLevelPair>
  </turboFilter>
  ......
</configuration>
MDC.put("LOG_LEVEL", "INFO");

Using Colormaps to set color of line in matplotlib

U may do as I have written from my deleted account (ban for new posts :( there was). Its rather simple and nice looking.

Im using 3-rd one of these 3 ones usually, also I wasny checking 1 and 2 version.

from matplotlib.pyplot import cm
import numpy as np

#variable n should be number of curves to plot (I skipped this earlier thinking that it is obvious when looking at picture - sorry my bad mistake xD): n=len(array_of_curves_to_plot)
#version 1:

color=cm.rainbow(np.linspace(0,1,n))
for i,c in zip(range(n),color):
   ax1.plot(x, y,c=c)

#or version 2: - faster and better:

color=iter(cm.rainbow(np.linspace(0,1,n)))
c=next(color)
plt.plot(x,y,c=c)

#or version 3:

color=iter(cm.rainbow(np.linspace(0,1,n)))
for i in range(n):
   c=next(color)
   ax1.plot(x, y,c=c)

example of 3:

Ship RAO of Roll vs Ikeda damping in function of Roll amplitude A44

Oracle - Insert New Row with Auto Incremental ID

the complete know how, i have included a example of the triggers and sequence

create table temasforo(
idtemasforo NUMBER(5) PRIMARY KEY,
autor       VARCHAR2(50) NOT NULL,
fecha       DATE DEFAULT (sysdate),
asunto      LONG  );

create sequence temasforo_seq
  start with 1
  increment by 1
  nomaxvalue;

create or replace
trigger temasforo_trigger
  before insert on temasforo
  referencing OLD as old NEW as new
  for each row
  begin
      :new.idtemasforo:=temasforo_seq.nextval;
    end;

reference: http://thenullpointerexceptionx.blogspot.mx/2013/06/llaves-primarias-auto-incrementales-en.html

Convert INT to FLOAT in SQL

In oracle db there is a trick for casting int to float (I suppose, it should also work in mysql):

select myintfield + 0.0 as myfloatfield from mytable

While @Heximal's answer works, I don't personally recommend it.

This is because it uses implicit casting. Although you didn't type CAST, either the SUM() or the 0.0 need to be cast to be the same data-types, before the + can happen. In this case the order of precedence is in your favour, and you get a float on both sides, and a float as a result of the +. But SUM(aFloatField) + 0 does not yield an INT, because the 0 is being implicitly cast to a FLOAT.

I find that in most programming cases, it is much preferable to be explicit. Don't leave things to chance, confusion, or interpretation.

If you want to be explicit, I would use the following.

CAST(SUM(sl.parts) AS FLOAT) * cp.price
-- using MySQL CAST FLOAT  requires 8.0

I won't discuss whether NUMERIC or FLOAT *(fixed point, instead of floating point)* is more appropriate, when it comes to rounding errors, etc. I'll just let you google that if you need to, but FLOAT is so massively misused that there is a lot to read about the subject already out there.

You can try the following to see what happens...

CAST(SUM(sl.parts) AS NUMERIC(10,4)) * CAST(cp.price AS NUMERIC(10,4))

"call to undefined function" error when calling class method

You dont have a function named assign(), but a method with this name. PHP is not Java and in PHP you have to make clear, if you want to call a function

assign()

or a method

$object->assign()

In your case the call to the function resides inside another method. $this always refers to the object, in which a method exists, itself.

$this->assign()

Execution sequence of Group By, Having and Where clause in SQL Server?

This is the SQL Order of execution of a Query,

enter image description here

You can check order of execution with examples from this article.

For you question below lines might be helpful and directly got from this article.

  1. GROUP BY --> The remaining rows after the WHERE constraints are applied are then grouped based on common values in the column specified in the GROUP BY clause. As a result of the grouping, there will only be as many rows as there are unique values in that column. Implicitly, this means that you should only need to use this when you have aggregate functions in your query.
  1. HAVING --> If the query has a GROUP BY clause, then the constraints in the HAVING clause are then applied to the grouped rows, discard the grouped rows that don't satisfy the constraint. Like the WHERE clause, aliases are also not accessible from this step in most databases.

References:-

Why does Java's hashCode() in String use 31 as a multiplier?

According to Joshua Bloch's Effective Java (a book that can't be recommended enough, and which I bought thanks to continual mentions on stackoverflow):

The value 31 was chosen because it is an odd prime. If it were even and the multiplication overflowed, information would be lost, as multiplication by 2 is equivalent to shifting. The advantage of using a prime is less clear, but it is traditional. A nice property of 31 is that the multiplication can be replaced by a shift and a subtraction for better performance: 31 * i == (i << 5) - i. Modern VMs do this sort of optimization automatically.

(from Chapter 3, Item 9: Always override hashcode when you override equals, page 48)

Finding the number of non-blank columns in an Excel sheet using VBA

Jean-François Corbett's answer is perfect. To be exhaustive I would just like to add that with some restrictons you could also use UsedRange.Columns.Count or UsedRange.Rows.Count.
The problem is that UsedRange is not always updated when deleting rows/columns (at least until you reopen the workbook).

replacing text in a file with Python

Reading from standard input, write 'code.py' as follows:

import sys

rep = {'zero':'0', 'temp':'bob', 'garbage':'nothing'}

for line in sys.stdin:
    for k, v in rep.iteritems():
        line = line.replace(k, v)
    print line

Then, execute the script with redirection or piping (http://en.wikipedia.org/wiki/Redirection_(computing))

python code.py < infile > outfile

How to execute AngularJS controller function on page load?

angular.element(document).ready(function () {

    // your code here

});

Downloading a file from spring controllers

What I can quickly think of is, generate the pdf and store it in webapp/downloads/< RANDOM-FILENAME>.pdf from the code and send a forward to this file using HttpServletRequest

request.getRequestDispatcher("/downloads/<RANDOM-FILENAME>.pdf").forward(request, response);

or if you can configure your view resolver something like,

  <bean id="pdfViewResolver"
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="viewClass"
              value="org.springframework.web.servlet.view.JstlView" />
    <property name="order" value=”2"/>
    <property name="prefix" value="/downloads/" />
    <property name="suffix" value=".pdf" />
  </bean>

then just return

return "RANDOM-FILENAME";

How can I save application settings in a Windows Forms application?

The registry is a no-go. You're not sure whether the user which uses your application, has sufficient rights to write to the registry.

You can use the app.config file to save application-level settings (that are the same for each user who uses your application).

I would store user-specific settings in an XML file, which would be saved in Isolated Storage or in the SpecialFolder.ApplicationData directory.

Next to that, as from .NET 2.0, it is possible to store values back to the app.config file.

How to put a jar in classpath in Eclipse?

Right click your project in eclipse, build path -> add external jars.

TypeError: document.getElementbyId is not a function

JavaScript is case-sensitive. The b in getElementbyId should be capitalized.

var content = document.getElementById("edit").innerHTML;

Java: unparseable date exception

I encountered this error working in Talend. I was able to store S3 CSV files created from Redshift without a problem. The error occurred when I was trying to load the same S3 CSV files into an Amazon RDS MySQL database. I tried the default timestamp Talend timestamp formats but they were throwing exception:unparseable date when loading into MySQL.

This from the accepted answer helped me solve this problem:

By the way, the "unparseable date" exception can here only be thrown by SimpleDateFormat#parse(). This means that the inputDate isn't in the expected pattern "yyyy-MM-dd HH:mm:ss z". You'll probably need to modify the pattern to match the inputDate's actual pattern

The key to my solution was changing the Talend schema. Talend set the timestamp field to "date" so I changed it to "timestamp" then I inserted "yyyy-MM-dd HH:mm:ss z" into the format string column view a screenshot here talend schema

I had other issues with 12 hour and 24 hour timestamp translations until I added the "z" at the end of the timestamp string.

Start thread with member function

Since you are using C++11, lambda-expression is a nice&clean solution.

class blub {
    void test() {}
  public:
    std::thread spawn() {
      return std::thread( [this] { this->test(); } );
    }
};

since this-> can be omitted, it could be shorten to:

std::thread( [this] { test(); } )

or just (deprecated)

std::thread( [=] { test(); } )

LIMIT 10..20 in SQL Server

as you found, this is the preferred sql server method:

SELECT * FROM ( 
  SELECT *, ROW_NUMBER() OVER (ORDER BY name) as row FROM sys.databases 
 ) a WHERE a.row > 5 and a.row <= 10

How to merge rows in a column into one cell in excel?

Inside CONCATENATE you can use TRANSPOSE if you expand it (F9) then remove the surrounding {}brackets like this recommends

=CONCATENATE(TRANSPOSE(B2:B19))

Becomes

=CONCATENATE("Oh ","combining ", "a " ...)

CONCATENATE(TRANSPOSE(B2:B19))

You may need to add your own separator on the end, say create a column C and transpose that column.

=B1&" "
=B2&" "
=B3&" "

WebRTC vs Websockets: If WebRTC can do Video, Audio, and Data, why do I need Websockets?

Comparing websocket and webrtc is unfair.

Websocket is based on top of TCP. Packet's boundary can be detected from header information of a websocket packet unlike tcp.

Typically, webrtc makes use of websocket. The signalling for webrtc is not defined, it is upto the service provider what kind of signalling he wants to use. It may be SIP, HTTP, JSON or any text / binary message.

The signalling messages can be send / received using websocket.

Objective-C: Calling selectors with multiple arguments

iOS users also expect autocapitalization: In a standard text field, the first letter of a sentence in a case-sensitive language is automatically capitalized.

You can decide whether or not to implement such features; there is no dedicated API for any of the features just listed, so providing them is a competitive advantage.

Apple document is saying there is no API available for this feature and some other expected feature in a customkeyboard. so you need to find out your own logic to implement this.

Getting IPV4 address from a sockaddr structure

Emil's answer is correct, but it's my understanding that inet_ntoa is deprecated and that instead you should use inet_ntop. If you are using IPv4, cast your struct sockaddr to sockaddr_in. Your code will look something like this:

struct addrinfo *res;   // populated elsewhere in your code
struct sockaddr_in *ipv4 = (struct sockaddr_in *)res->ai_addr;
char ipAddress[INET_ADDRSTRLEN];
inet_ntop(AF_INET, &(ipv4->sin_addr), ipAddress, INET_ADDRSTRLEN);

printf("The IP address is: %s\n", ipAddress);

Take a look at this great resource for more explanation, including how to do this for IPv6 addresses.

window.history.pushState refreshing the browser

As others have suggested, you are not clearly explaining your problem, what you are trying to do, or what your expectations are as to what this function is actually supposed to do.

If I have understood correctly, then you are expecting this function to refresh the page for you (you actually use the term "reloads the browser").

But this function is not intended to reload the browser.

All the function does, is to add (push) a new "state" onto the browser history, so that in future, the user will be able to return to this state that the web-page is now in.

Normally, this is used in conjunction with AJAX calls (which refresh only a part of the page).

For example, if a user does a search "CATS" in one of your search boxes, and the results of the search (presumably cute pictures of cats) are loaded back via AJAX, into the lower-right of your page -- then your page state will not be changed. In other words, in the near future, when the user decides that he wants to go back to his search for "CATS", he won't be able to, because the state doesn't exist in his history. He will only be able to click back to your blank search box.

Hence the need for the function

history.pushState({},"Results for `Cats`",'url.html?s=cats');

It is intended as a way to allow the programmer to specifically define his search into the user's history trail. That's all it is intended to do.

When the function is working properly, the only thing you should expect to see, is the address in your browser's address-bar change to whatever you specify in your URL.

If you already understand this, then sorry for this long preamble. But it sounds from the way you pose the question, that you have not.

As an aside, I have also found some contradictions between the way that the function is described in the documentation, and the way it works in reality. I find that it is not a good idea to use blank or empty values as parameters.

See my answer to this SO question. So I would recommend putting a description in your second parameter. From memory, this is the description that the user sees in the drop-down, when he clicks-and-holds his mouse over "back" button.

How to use function srand() with time.h?

#include"stdio.h"
#include"conio.h"
#include"time.h"

void main()
{
  time_t t;
  int i;
  srand(time(&t));

  for(i=1;i<=10;i++)
    printf("%c\t",rand()%10);
  getch();
}

Using json_encode on objects in PHP (regardless of scope)

I didn't see this mentioned yet, but beans have a built-in method called getProperties().

So, to use it:

// What bean do we want to get?
$type = 'book';
$id = 13;

// Load the bean
$post = R::load($type,$id);

// Get the properties
$props = $post->getProperties();

// Print the JSON-encoded value
print json_encode($props);

This outputs:

{
    "id": "13",
    "title": "Oliver Twist",
    "author": "Charles Dickens"
}

Now take it a step further. If we have an array of beans...

// An array of beans (just an example)
$series = array($post,$post,$post);

...then we could do the following:

  • Loop through the array with a foreach loop.

  • Replace each element (a bean) with an array of the bean's properties.

So this...

foreach ($series as &$val) {
  $val = $val->getProperties();
}

print json_encode($series);

...outputs this:

[
    {
        "id": "13",
        "title": "Oliver Twist",
        "author": "Charles Dickens"
    },
    {
        "id": "13",
        "title": "Oliver Twist",
        "author": "Charles Dickens"
    },
    {
        "id": "13",
        "title": "Oliver Twist",
        "author": "Charles Dickens"
    }
]

Hope this helps!

AngularJS does not send hidden field value

You cannot use double binding with hidden field. The solution is to use brackets :

<input type="hidden" name="someData" value="{{data}}" /> {{data}}

EDIT : See this thread on github : https://github.com/angular/angular.js/pull/2574

EDIT:

Since Angular 1.2, you can use 'ng-value' directive to bind an expression to the value attribute of input. This directive should be used with input radio or checkbox but works well with hidden input.

Here is the solution using ng-value:

<input type="hidden" name="someData" ng-value="data" />

Here is a fiddle using ng-value with an hidden input: http://jsfiddle.net/6SD9N

What is the meaning of 'No bundle URL present' in react-native?

Open a terminal window

cd into YOUR_PROJECT/ios

Remove the build folder with rm -r build

After that open your project in Xcode and run once. it will run with starting the server and create the main.jsbundle file.

Now if you Run react-native run-ios from terminal again it will work as expected.

Hope it will help!.

How to get the cell value by column name not by index in GridView in asp.net

For Lambda lovers

protected void GridView_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        var boundFields = e.Row.Cells.Cast<DataControlFieldCell>()
            .Select(cell => cell.ContainingField).Cast<BoundField>().ToList();

        int idx = boundFields.IndexOf(
            boundFields.FirstOrDefault(f => f.DataField == "ColName"));

        e.Row.Cells[idx].Text = modification;        
    }
}

Android - shadow on text?

You should be able to add the style, like this (taken from source code for Ringdroid):

  <style name="AudioFileInfoOverlayText">
    <item name="android:paddingLeft">4px</item>
    <item name="android:paddingBottom">4px</item>
    <item name="android:textColor">#ffffffff</item>
    <item name="android:textSize">12sp</item>
    <item name="android:shadowColor">#000000</item>
    <item name="android:shadowDx">1</item>
    <item name="android:shadowDy">1</item>
    <item name="android:shadowRadius">1</item>
  </style>

And in your layout, use the style like this:

 <TextView android:id="@+id/info"
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       style="@style/AudioFileInfoOverlayText"
       android:gravity="center" />

Edit: the source code can be viewed here: https://github.com/google/ringdroid

Edit2: To set this style programmatically, you'd do something like this (modified from this example to match ringdroid's resources from above)

TextView infoTextView = (TextView) findViewById(R.id.info);
infoTextView.setTextAppearance(getApplicationContext(),  
       R.style.AudioFileInfoOverlayText);

The signature for setTextAppearance is

public void setTextAppearance (Context context, int resid)

Since: API Level 1
Sets the text color, size, style, hint color, and highlight color from the specified TextAppearance resource.

How to create a new object instance from a Type

If this is for something that will be called a lot in an application instance, it's a lot faster to compile and cache dynamic code instead of using the activator or ConstructorInfo.Invoke(). Two easy options for dynamic compilation are compiled Linq Expressions or some simple IL opcodes and DynamicMethod. Either way, the difference is huge when you start getting into tight loops or multiple calls.

The input is not a valid Base-64 string as it contains a non-base 64 character

Since you're returning a string as JSON, that string will include the opening and closing quotes in the raw response. So your response should probably look like:

"abc123XYZ=="

or whatever...You can try confirming this with Fiddler.

My guess is that the result.Content is the raw string, including the quotes. If that's the case, then result.Content will need to be deserialized before you can use it.

Laravel blank white screen

An update to fideloper's answer for Laravel 5 and its new file structure is:

$ sudo chmod -R o+w storage/

check for null date in CASE statement, where have I gone wrong?

select Id, StartDate,
Case IsNull (StartDate , '01/01/1800')
When '01/01/1800' then
  'Awaiting'
Else
  'Approved'
END AS StartDateStatus
From MyTable

how to check if string contains '+' character

[+]is simpler

    String s = "ddjdjdj+kfkfkf";

    if(s.contains ("+"))
    {
        String parts[] = s.split("[+]");
        s =  parts[0]; // i want to strip part after  +
    }
    System.out.println(s);

Import SQL file into mysql

from the command line (cmd.exe, not from within mysql shell) try something like:

type c:/nite.sql | mysql -uuser -ppassword dbname

Binding objects defined in code-behind

Define a converter:

public class RowIndexConverter : IValueConverter
{
    public object Convert( object value, Type targetType,
                           object parameter, CultureInfo culture )
    {
        var row = (IDictionary<string, object>) value;
        var key = (string) parameter;
        return row.Keys.Contains( key ) ? row[ key ] : null;
    }

    public object ConvertBack( object value, Type targetType,
                               object parameter, CultureInfo culture )
    {
        throw new NotImplementedException( );
    }
}

Bind to a custom definition of a Dictionary. There's lot of overrides that I've omitted, but the indexer is the important one, because it emits the property changed event when the value is changed. This is required for source to target binding.

public class BindableRow : INotifyPropertyChanged, IDictionary<string, object>
{
    private Dictionary<string, object> _data = new Dictionary<string, object>( );

    public object Dummy   // Provides a dummy property for the column to bind to
    {
        get
        {
            return this;
        }
        set
        {
            var o = value;
        }
    }


    public object this[ string index ]
    {
        get
        {
            return _data[ index ];
        }
        set
        {
            _data[ index ] = value;
            InvokePropertyChanged( new PropertyChangedEventArgs( "Dummy" ) ); // Trigger update
        }
    }


}

In your .xaml file use this converter. First reference it:

<UserControl.Resources>
    <ViewModelHelpers:RowIndexConverter x:Key="RowIndexConverter"/>
</UserControl.Resources>

Then, for instance, if your dictionary has an entry where the key is "Name", then to bind to it: use

<TextBlock  Text="{Binding Dummy, Converter={StaticResource RowIndexConverter}, ConverterParameter=Name}">

Permissions error when connecting to EC2 via SSH on Mac OSx

Are you sure you have used the right instance? I ran into this problem and realized that something like 4 of the ubuntu instances i tried did not have SSH servers installed on them.

For a list of good servers see "Getting the images" about half way down. Sounds like you may be using something else... the default username is ubuntu on these images.

https://help.ubuntu.com/community/EC2StartersGuide

Swift GET request with parameters

When building a GET request, there is no body to the request, but rather everything goes on the URL. To build a URL (and properly percent escaping it), you can also use URLComponents.

var url = URLComponents(string: "https://www.google.com/search/")!

url.queryItems = [
    URLQueryItem(name: "q", value: "War & Peace")
]

The only trick is that most web services need + character percent escaped (because they'll interpret that as a space character as dictated by the application/x-www-form-urlencoded specification). But URLComponents will not percent escape it. Apple contends that + is a valid character in a query and therefore shouldn't be escaped. Technically, they are correct, that it is allowed in a query of a URI, but it has a special meaning in application/x-www-form-urlencoded requests and really should not be passed unescaped.

Apple acknowledges that we have to percent escaping the + characters, but advises that we do it manually:

var url = URLComponents(string: "https://www.wolframalpha.com/input/")!

url.queryItems = [
    URLQueryItem(name: "i", value: "1+2")
]

url.percentEncodedQuery = url.percentEncodedQuery?.replacingOccurrences(of: "+", with: "%2B")

This is an inelegant work-around, but it works, and is what Apple advises if your queries may include a + character and you have a server that interprets them as spaces.

So, combining that with your sendRequest routine, you end up with something like:

func sendRequest(_ url: String, parameters: [String: String], completion: @escaping ([String: Any]?, Error?) -> Void) {
    var components = URLComponents(string: url)!
    components.queryItems = parameters.map { (key, value) in 
        URLQueryItem(name: key, value: value) 
    }
    components.percentEncodedQuery = components.percentEncodedQuery?.replacingOccurrences(of: "+", with: "%2B")
    let request = URLRequest(url: components.url!)

    let task = URLSession.shared.dataTask(with: request) { data, response, error in
        guard let data = data,                            // is there data
            let response = response as? HTTPURLResponse,  // is there HTTP response
            (200 ..< 300) ~= response.statusCode,         // is statusCode 2XX
            error == nil else {                           // was there no error, otherwise ...
                completion(nil, error)
                return
        }

        let responseObject = (try? JSONSerialization.jsonObject(with: data)) as? [String: Any]
        completion(responseObject, nil)
    }
    task.resume()
}

And you'd call it like:

sendRequest("someurl", parameters: ["foo": "bar"]) { responseObject, error in
    guard let responseObject = responseObject, error == nil else {
        print(error ?? "Unknown error")
        return
    }

    // use `responseObject` here
}

Personally, I'd use JSONDecoder nowadays and return a custom struct rather than a dictionary, but that's not really relevant here. Hopefully this illustrates the basic idea of how to percent encode the parameters into the URL of a GET request.


See previous revision of this answer for Swift 2 and manual percent escaping renditions.

Insert string in beginning of another string

The first case is done using the insert() method:

_sb.insert(0, "Hello ");

The latter case can be done using the overloaded + operator on Strings. This uses a StringBuilder behind the scenes:

String s2 = "Hello " + _s;

Ruby on Rails. How do I use the Active Record .build method in a :belongs to relationship?

Where it is documented:

From the API documentation under the has_many association in "Module ActiveRecord::Associations::ClassMethods"

collection.build(attributes = {}, …) Returns one or more new objects of the collection type that have been instantiated with attributes and linked to this object through a foreign key, but have not yet been saved. Note: This only works if an associated object already exists, not if it‘s nil!

The answer to building in the opposite direction is a slightly altered syntax. In your example with the dogs,

Class Dog
   has_many :tags
   belongs_to :person
end

Class Person
  has_many :dogs
end

d = Dog.new
d.build_person(:attributes => "go", :here => "like normal")

or even

t = Tag.new
t.build_dog(:name => "Rover", :breed => "Maltese")

You can also use create_dog to have it saved instantly (much like the corresponding "create" method you can call on the collection)

How is rails smart enough? It's magic (or more accurately, I just don't know, would love to find out!)

How to check whether a int is not null or empty?

An integer can't be null but there is a really simple way of doing what you want to do. Use an if-then statement in which you check the integer's value against all possible values.

Example:

int x;

// Some Code...

if (x <= 0 || x > 0){
    // What you want the code to do if x has a value
} else {
    // What you want the code to do if x has no value 
}

Disclaimer: I am assuming that Java does not automatically set values of numbers to 0 if it doesn't see a value.

How do I escape a reserved word in Oracle?

you have to rename the column to an other name because TABLE is reserved by Oracle.

You can see all reserved words of Oracle in the oracle view V$RESERVED_WORDS.

Export data from R to Excel

Recently used xlsx package, works well.

library(xlsx)
write.xlsx(x, file, sheetName="Sheet1")

where x is a data.frame

How Do I Get the Query Builder to Output Its Raw SQL Query as a String?

Here comes the perfect example:

https://laravel.com/docs/5.8/database#listening-for-query-events

Open app\Providers\AppServiceProvider.php and add the following to Boot() function:

DB::listen(function ($query) {
    var_dump([
        $query->sql,
        $query->bindings,
        $query->time
    ]);
});

So you don't need to put DB::enableQuerylog() and DB::getQuerylog() in every function.

How do I localize the jQuery UI Datepicker?

I figured out the demo and implemented it the following way:

$.datepicker.setDefaults(
  $.extend(
    {'dateFormat':'dd-mm-yy'},
    $.datepicker.regional['nl']
  )
);

I needed to set the default for the dateformat too ...

ASP.NET MVC controller actions that return JSON or partial html

PartialViewResult and JSONReuslt inherit from the base class ActionResult. so if return type is decided dynamically declare method output as ActionResult.

public ActionResult DynamicReturnType(string parameter)
        {
            if (parameter == "JSON")
                return Json("<JSON>", JsonRequestBehavior.AllowGet);
            else if (parameter == "PartialView")
                return PartialView("<ViewName>");
            else
                return null;


        }

How to use execvp()

In cpp, you need to pay special attention to string types when using execvp:

#include <iostream>
#include <string>
#include <cstring>
#include <stdio.h>
#include <unistd.h>
using namespace std;

const size_t MAX_ARGC = 15; // 1 command + # of arguments
char* argv[MAX_ARGC + 1]; // Needs +1 because of the null terminator at the end
// c_str() converts string to const char*, strdup converts const char* to char*
argv[0] = strdup(command.c_str());

// start filling up the arguments after the first command
size_t arg_i = 1;
while (cin && arg_i < MAX_ARGC) {
    string arg;
    cin >> arg;
    if (arg.empty()) {
        argv[arg_i] = nullptr;
        break;
    } else {
        argv[arg_i] = strdup(arg.c_str());
    }
    ++arg_i;
}

// Run the command with arguments
if (execvp(command.c_str(), argv) == -1) {
    // Print error if command not found
    cerr << "command '" << command << "' not found\n";
}

Reference: execlp?execvp?????

How do I get specific properties with Get-AdUser

using select-object for example:

Get-ADUser -Filter * -SearchBase 'OU=Users & Computers, DC=aaaaaaa, DC=com' -Properties DisplayName | select -expand displayname | Export-CSV "ADUsers.csv" 

Trying to Validate URL Using JavaScript

Demo : http://jsbin.com/uzimeb/1/edit

function checkURL(value) {
    var urlregex = new RegExp("^(http|https|ftp)\://([a-zA-Z0-9\.\-]+(\:[a-zA-Z0-9\.&amp;%\$\-]+)*@)*((25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9])\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[1-9]|0)\.(25[0-5]|2[0-4][0-9]|[0-1]{1}[0-9]{2}|[1-9]{1}[0-9]{1}|[0-9])|([a-zA-Z0-9\-]+\.)*[a-zA-Z0-9\-]+\.(com|edu|gov|int|mil|net|org|biz|arpa|info|name|pro|aero|coop|museum|[a-zA-Z]{2}))(\:[0-9]+)*(/($|[a-zA-Z0-9\.\,\?\'\\\+&amp;%\$#\=~_\-]+))*$");
    if (urlregex.test(value)) {
        return (true);
    }
    return (false);
}

What's the difference between a single precision and double precision floating point operation?

Single precision number uses 32 bits, with the MSB being sign bit, whereas double precision number uses 64bits, MSB being sign bit

Single precision

SEEEEEEEEFFFFFFFFFFFFFFFFFFFFFFF.(SIGN+EXPONENT+SIGNIFICAND)

Double precision:

SEEEEEEEEEEEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF.(SIGN+EXPONENT+SIGNIFICAND)

How do I keep CSS floats in one line?

Another option: Do not float your right column; just give it a left margin to move it beyond the float. You'll need a hack or two to fix IE6, but that's the basic idea.

How to set up Android emulator proxy settings

Now there is a setting in Android emulator enter image description here

blur() vs. onblur()

This:

document.getElementById('myField').onblur();

works because your element (the <input>) has an attribute called "onblur" whose value is a function. Thus, you can call it. You're not telling the browser to simulate the actual "blur" event, however; there's no event object created, for example.

Elements do not have a "blur" attribute (or "method" or whatever), so that's why the first thing doesn't work.

Updating state on props change in React Form

It's quite clearly from their docs:

If you used componentWillReceiveProps for re-computing some data only when a prop changes, use a memoization helper instead.

Use: https://reactjs.org/blog/2018/06/07/you-probably-dont-need-derived-state.html#what-about-memoization

Is there a WebSocket client implemented for Python?

Since I have been doing a bit of research in that field lately (Jan, '12), the most promising client is actually : WebSocket for Python. It support a normal socket that you can call like this :

ws = EchoClient('http://localhost:9000/ws')

The client can be Threaded or based on IOLoop from Tornado project. This will allow you to create a multi concurrent connection client. Useful if you want to run stress tests.

The client also exposes the onmessage, opened and closed methods. (WebSocket style).

python and sys.argv

BTW you can pass the error message directly to sys.exit:

if len(sys.argv) < 2:
    sys.exit('Usage: %s database-name' % sys.argv[0])

if not os.path.exists(sys.argv[1]):
    sys.exit('ERROR: Database %s was not found!' % sys.argv[1])

How to clone ArrayList and also clone its contents?

You will need to clone the ArrayList by hand (by iterating over it and copying each element to a new ArrayList), because clone() will not do it for you. Reason for this is that the objects contained in the ArrayList may not implement Clonable themselves.

Edit: ... and that is exactly what Varkhan's code does.

Using R to download zipped data file, extract, and import data

Try this code. It works for me:

unzip(zipfile="<directory and filename>",
      exdir="<directory where the content will be extracted>")

Example:

unzip(zipfile="./data/Data.zip",exdir="./data")

Div vertical scrollbar show

Always : If you always want vertical scrollbar, use overflow-y: scroll;

jsFiddle:

<div style="overflow-y: scroll;">
......
</div>

When needed: If you only want vertical scrollbar when needed, use overflow-y: auto; (You need to specify a height in this case)

jsFiddle:

<div style="overflow-y: auto; height:150px; ">
....
</div>

Convert NSNumber to int in Objective-C

A less verbose approach:

int number = [dict[@"integer"] intValue];

Can't connect to MySQL server on 'localhost' (10061)

I tried Kuzhichamadam Inn's solution and found that a slight change needed to be made.

MYSQL57 was a network service. I had tried this repeatedly with no success. When I opened services.msc I found another service for localhost: MySQL. I started that one using the process below and it worked.

run > services.msc > rightclick MySQL > properties >start

How to convert string to integer in UNIX

An answer that is not limited to the OP's case

The title of the question leads people here, so I decided to answer that question for everyone else since the OP's described case was so limited.

TL;DR

I finally settled on writing a function.

  1. If you want 0 in case of non-int:
int(){ printf '%d' ${1:-} 2>/dev/null || :; }
  1. If you want [empty_string] in case of non-int:
int(){ expr 0 + ${1:-} 2>/dev/null||:; }
  1. If you want find the first int or [empty_string]:
int(){ expr ${1:-} : '[^0-9]*\([0-9]*\)' 2>/dev/null||:; }
  1. If you want find the first int or 0:
# This is a combination of numbers 1 and 2
int(){ expr ${1:-} : '[^0-9]*\([0-9]*\)' 2>/dev/null||:; }

If you want to get a non-zero status code on non-int, remove the ||: (aka or true) but leave the ;

Tests

# Wrapped in parens to call a subprocess and not `set` options in the main bash process
# In other words, you can literally copy-paste this code block into your shell to test
( set -eu;
    tests=( 4 "5" "6foo" "bar7" "foo8.9bar" "baz" " " "" )
    test(){ echo; type int; for test in "${tests[@]}"; do echo "got '$(int $test)' from '$test'"; done; echo "got '$(int)' with no argument"; }

    int(){ printf '%d' ${1:-} 2>/dev/null||:; };
    test

    int(){ expr 0 + ${1:-} 2>/dev/null||:; }
    test

    int(){ expr ${1:-} : '[^0-9]*\([0-9]*\)' 2>/dev/null||:; }
    test

    int(){ printf '%d' $(expr ${1:-} : '[^0-9]*\([0-9]*\)' 2>/dev/null)||:; }
    test

    # unexpected inconsistent results from `bc`
    int(){ bc<<<"${1:-}" 2>/dev/null||:; }
    test
)

Test output

int is a function
int ()
{
    printf '%d' ${1:-} 2> /dev/null || :
}
got '4' from '4'
got '5' from '5'
got '0' from '6foo'
got '0' from 'bar7'
got '0' from 'foo8.9bar'
got '0' from 'baz'
got '0' from ' '
got '0' from ''
got '0' with no argument

int is a function
int ()
{
    expr 0 + ${1:-} 2> /dev/null || :
}
got '4' from '4'
got '5' from '5'
got '' from '6foo'
got '' from 'bar7'
got '' from 'foo8.9bar'
got '' from 'baz'
got '' from ' '
got '' from ''
got '' with no argument

int is a function
int ()
{
    expr ${1:-} : '[^0-9]*\([0-9]*\)' 2> /dev/null || :
}
got '4' from '4'
got '5' from '5'
got '6' from '6foo'
got '7' from 'bar7'
got '8' from 'foo8.9bar'
got '' from 'baz'
got '' from ' '
got '' from ''
got '' with no argument

int is a function
int ()
{
    printf '%d' $(expr ${1:-} : '[^0-9]*\([0-9]*\)' 2>/dev/null) || :
}
got '4' from '4'
got '5' from '5'
got '6' from '6foo'
got '7' from 'bar7'
got '8' from 'foo8.9bar'
got '0' from 'baz'
got '0' from ' '
got '0' from ''
got '0' with no argument

int is a function
int ()
{
    bc <<< "${1:-}" 2> /dev/null || :
}
got '4' from '4'
got '5' from '5'
got '' from '6foo'
got '0' from 'bar7'
got '' from 'foo8.9bar'
got '0' from 'baz'
got '' from ' '
got '' from ''
got '' with no argument

Note

I got sent down this rabbit hole because the accepted answer is not compatible with set -o nounset (aka set -u)

# This works
$ ( number="3"; string="foo"; echo $((number)) $((string)); )
3 0

# This doesn't
$ ( set -u; number="3"; string="foo"; echo $((number)) $((string)); )
-bash: foo: unbound variable

Exception : javax.net.ssl.SSLPeerUnverifiedException: peer not authenticated

if you are in dev mode with not valid certificate, why not just set weClient.setUseInsecureSSL(true). works for me

How to use LogonUser properly to impersonate domain user from workgroup client

Very few posts suggest using LOGON_TYPE_NEW_CREDENTIALS instead of LOGON_TYPE_NETWORK or LOGON_TYPE_INTERACTIVE. I had an impersonation issue with one machine connected to a domain and one not, and this fixed it. The last code snippet in this post suggests that impersonating across a forest does work, but it doesn't specifically say anything about trust being set up. So this may be worth trying:

const int LOGON_TYPE_NEW_CREDENTIALS = 9;
const int LOGON32_PROVIDER_WINNT50 = 3;
bool returnValue = LogonUser(user, domain, password,
            LOGON_TYPE_NEW_CREDENTIALS, LOGON32_PROVIDER_WINNT50,
            ref tokenHandle);

MSDN says that LOGON_TYPE_NEW_CREDENTIALS only works when using LOGON32_PROVIDER_WINNT50.

How to set a default value with Html.TextBoxFor?

this worked for me , in this way we setting the default value to empty string

@Html.TextBoxFor(m => m.Id, new { @Value = "" })

java.lang.RuntimeException: Uncompilable source code - what can cause this?

I had the same issue with one of my netbeans project.

Check whether you have correctly put the package name on all the classes. I got the same error message because i forgot to put the package name of a certain class (which was copied from another project).

How to create a multi line body in C# System.Net.Mail.MailMessage

Try using a StringBuilder object and use the appendline method. That might work.

How can I tell gcc not to inline a function?

Use the noinline attribute:

int func(int arg) __attribute__((noinline))
{
}

You should probably use it both when you declare the function for external use and when you write the function.

Really killing a process in Windows

taskkill /im myprocess.exe /f

The "/f" is for "force". If you know the PID, then you can specify that, as in:

taskkill /pid 1234 /f

Lots of other options are possible, just type taskkill /? for all of them. The "/t" option kills a process and any child processes; that may be useful to you.

What's the difference between REST & RESTful

REST is an architectural pattern for creating web services. A RESTful service is one that implements that pattern.

XMLHttpRequest cannot load file. Cross origin requests are only supported for HTTP

This error is happening because you are just opening html documents directly from the browser. To fix this you will need to serve your code from a webserver and access it on localhost. If you have Apache setup, use it to serve your files. Some IDE's have built in web servers, like JetBrains IDE's, Eclipse...

If you have Node.Js setup then you can use http-server. Just run npm install http-server -g and you will be able to use it in terminal like http-server C:\location\to\app. Kirill Fuchs

Current date without time

Use the Date property: Gets the date component of this instance.

var dateAndTime = DateTime.Now;
var date = dateAndTime.Date;

variable date contain the date and the time part will be 00:00:00.

or

Console.WriteLine(DateTime.Now.ToString("dd/MM/yyyy"));

or

DateTime.ToShortDateString Method-

Console.WriteLine(DateTime.Now.ToShortDateString ());

How to make a website secured with https

@balalakshmi mentioned about the correct authentication settings. Authentication is only half of the problem, the other half is authorization.

If you're using Forms Authentication and standard controls like <asp:Login> there are a couple of things you'll need to do to ensure that only your authenticated users can access secured pages.

In web.config, under the <system.web> section you'll need to disable anonymous access by default:

<authorization>
 <deny users="?" />
</authorization>

Any pages that will be accessed anonymously (such as the Login.aspx page itself) will need to have an override that re-allows anonymous access. This requires a <location> element and must be located at the <configuration> level (outside the <system.web> section), like this:

<!-- Anonymous files -->
<location path="Login.aspx">
 <system.web>
  <authorization>
   <allow users="*" />
  </authorization>
 </system.web>
</location>

Note that you'll also need to allow anonymous access to any style sheets or scripts that are used by the anonymous pages:

<!-- Anonymous folders -->
<location path="styles">
 <system.web>
  <authorization>
   <allow users="*" />
  </authorization>
 </system.web>
</location>

Be aware that the location's path attribute is relative to the web.config folder and cannot have a ~/ prefix, unlike most other path-type configuration attributes.

How do I find out what type each object is in a ArrayList<Object>?

If you expect the data to be numeric in some form, and all you are interested in doing is converting the result to a numeric value, I would suggest:

for (Object o:list) {
  Double.parseDouble(o.toString);
}

Returning from a void function

The only reason to have a return in a void function would be to exit early due to some conditional statement:

void foo(int y)
{
    if(y == 0) return;

    // do stuff with y
}

As unwind said: when the code ends, it ends. No need for an explicit return at the end.

How do I choose the URL for my Spring Boot webapp?

In Spring Boot 2 the property in e.g. application.properties is server.servlet.context-path=/myWebApp to set the context path.

https://docs.spring.io/spring-boot/docs/2.0.1.BUILD-SNAPSHOT/reference/htmlsingle/#_custom_context_path

json_decode to array

According to the PHP Documentation json_decode function has a parameter named assoc which convert the returned objects into associative arrays

 mixed json_decode ( string $json [, bool $assoc = FALSE ] )

Since assoc parameter is FALSE by default, You have to set this value to TRUE in order to retrieve an array.

Examine the below code for an example implication:

$json = '{"a":1,"b":2,"c":3,"d":4,"e":5}';
var_dump(json_decode($json));
var_dump(json_decode($json, true));

which outputs:

object(stdClass)#1 (5) {
    ["a"] => int(1)
    ["b"] => int(2)
    ["c"] => int(3)
    ["d"] => int(4)
    ["e"] => int(5)
}

array(5) {
    ["a"] => int(1)
    ["b"] => int(2)
    ["c"] => int(3)
    ["d"] => int(4)
    ["e"] => int(5)
}

Can I force pip to reinstall the current version?

If you have a text file with loads of packages you need to add the -r flag

pip install --upgrade --no-deps --force-reinstall -r requirements.txt