Programs & Examples On #Presenter

Flutter - The method was called on null

You should declare your method first in void initState(), so when the first time pages has been loaded, it will init your method first, hope it can help

What is difference between MVC, MVP & MVVM design pattern in terms of coding c#

Great Explanation from the link : http://geekswithblogs.net/dlussier/archive/2009/11/21/136454.aspx

Let's First look at MVC

The input is directed at the Controller first, not the view. That input might be coming from a user interacting with a page, but it could also be from simply entering a specific url into a browser. In either case, its a Controller that is interfaced with to kick off some functionality.

There is a many-to-one relationship between the Controller and the View. That’s because a single controller may select different views to be rendered based on the operation being executed.

There is one way arrow from Controller to View. This is because the View doesn’t have any knowledge of or reference to the controller.

The Controller does pass back the Model, so there is knowledge between the View and the expected Model being passed into it, but not the Controller serving it up.

MVP – Model View Presenter

Now let’s look at the MVP pattern. It looks very similar to MVC, except for some key distinctions:

The input begins with the View, not the Presenter.

There is a one-to-one mapping between the View and the associated Presenter.

The View holds a reference to the Presenter. The Presenter is also reacting to events being triggered from the View, so its aware of the View its associated with.

The Presenter updates the View based on the requested actions it performs on the Model, but the View is not Model aware.

MVVM – Model View View Model

So with the MVC and MVP patterns in front of us, let’s look at the MVVM pattern and see what differences it holds:

The input begins with the View, not the View Model.

While the View holds a reference to the View Model, the View Model has no information about the View. This is why its possible to have a one-to-many mapping between various Views and one View Model…even across technologies. For example, a WPF View and a Silverlight View could share the same View Model.

Moq, SetupGet, Mocking a property

ColumnNames is a property of type List<String> so when you are setting up you need to pass a List<String> in the Returns call as an argument (or a func which return a List<String>)

But with this line you are trying to return just a string

input.SetupGet(x => x.ColumnNames).Returns(temp[0]);

which is causing the exception.

Change it to return whole list:

input.SetupGet(x => x.ColumnNames).Returns(temp);

Need table of key codes for android and presenter

Keyboard(BT) commands can be passed through command prompt

open command prompt and write "adb shell input keyevent keycode"

examples:-

for "enter" write
adb shell input keyevent 23

up
adb shell input keyevent 19

down
adb shell input keyevent 20

left
adb shell input keyevent 21

right
adb shell input keyevent 22

keycode List:

0 -->  "KEYCODE_0" 
1 -->  "KEYCODE_SOFT_LEFT" 
2 -->  "KEYCODE_SOFT_RIGHT" 
3 -->  "KEYCODE_HOME" 
4 -->  "KEYCODE_BACK" 
5 -->  "KEYCODE_CALL" 
6 -->  "KEYCODE_ENDCALL" 
7 -->  "KEYCODE_0" 
8 -->  "KEYCODE_1" 
9 -->  "KEYCODE_2" 
10 -->  "KEYCODE_3" 
11 -->  "KEYCODE_4" 
12 -->  "KEYCODE_5" 
13 -->  "KEYCODE_6" 
14 -->  "KEYCODE_7" 
15 -->  "KEYCODE_8" 
16 -->  "KEYCODE_9" 
17 -->  "KEYCODE_STAR" 
18 -->  "KEYCODE_POUND" 
19 -->  "KEYCODE_DPAD_UP" 
20 -->  "KEYCODE_DPAD_DOWN" 
21 -->  "KEYCODE_DPAD_LEFT" 
22 -->  "KEYCODE_DPAD_RIGHT" 
23 -->  "KEYCODE_DPAD_CENTER" 
24 -->  "KEYCODE_VOLUME_UP" 
25 -->  "KEYCODE_VOLUME_DOWN" 
26 -->  "KEYCODE_POWER" 
27 -->  "KEYCODE_CAMERA" 
28 -->  "KEYCODE_CLEAR" 
29 -->  "KEYCODE_A" 
30 -->  "KEYCODE_B" 
31 -->  "KEYCODE_C" 
32 -->  "KEYCODE_D" 
33 -->  "KEYCODE_E" 
34 -->  "KEYCODE_F" 
35 -->  "KEYCODE_G" 
36 -->  "KEYCODE_H" 
37 -->  "KEYCODE_I" 
38 -->  "KEYCODE_J" 
39 -->  "KEYCODE_K" 
40 -->  "KEYCODE_L" 
41 -->  "KEYCODE_M" 
42 -->  "KEYCODE_N" 
43 -->  "KEYCODE_O" 
44 -->  "KEYCODE_P" 
45 -->  "KEYCODE_Q" 
46 -->  "KEYCODE_R" 
47 -->  "KEYCODE_S" 
48 -->  "KEYCODE_T" 
49 -->  "KEYCODE_U" 
50 -->  "KEYCODE_V" 
51 -->  "KEYCODE_W" 
52 -->  "KEYCODE_X" 
53 -->  "KEYCODE_Y" 
54 -->  "KEYCODE_Z" 
55 -->  "KEYCODE_COMMA" 
56 -->  "KEYCODE_PERIOD" 
57 -->  "KEYCODE_ALT_LEFT" 
58 -->  "KEYCODE_ALT_RIGHT" 
59 -->  "KEYCODE_SHIFT_LEFT" 
60 -->  "KEYCODE_SHIFT_RIGHT" 
61 -->  "KEYCODE_TAB" 
62 -->  "KEYCODE_SPACE" 
63 -->  "KEYCODE_SYM" 
64 -->  "KEYCODE_EXPLORER" 
65 -->  "KEYCODE_ENVELOPE" 
66 -->  "KEYCODE_ENTER" 
67 -->  "KEYCODE_DEL" 
68 -->  "KEYCODE_GRAVE" 
69 -->  "KEYCODE_MINUS" 
70 -->  "KEYCODE_EQUALS" 
71 -->  "KEYCODE_LEFT_BRACKET" 
72 -->  "KEYCODE_RIGHT_BRACKET" 
73 -->  "KEYCODE_BACKSLASH" 
74 -->  "KEYCODE_SEMICOLON" 
75 -->  "KEYCODE_APOSTROPHE" 
76 -->  "KEYCODE_SLASH" 
77 -->  "KEYCODE_AT" 
78 -->  "KEYCODE_NUM" 
79 -->  "KEYCODE_HEADSETHOOK" 
80 -->  "KEYCODE_FOCUS" 
81 -->  "KEYCODE_PLUS" 
82 -->  "KEYCODE_MENU" 
83 -->  "KEYCODE_NOTIFICATION" 
84 -->  "KEYCODE_SEARCH" 
85 -->  "KEYCODE_MEDIA_PLAY_PAUSE"
86 -->  "KEYCODE_MEDIA_STOP"
87 -->  "KEYCODE_MEDIA_NEXT"
88 -->  "KEYCODE_MEDIA_PREVIOUS"
89 -->  "KEYCODE_MEDIA_REWIND"
90 -->  "KEYCODE_MEDIA_FAST_FORWARD"
91 -->  "KEYCODE_MUTE"
92 -->  "KEYCODE_PAGE_UP"
93 -->  "KEYCODE_PAGE_DOWN"
94 -->  "KEYCODE_PICTSYMBOLS"
...
122 -->  "KEYCODE_MOVE_HOME"
123 -->  "KEYCODE_MOVE_END"

WPF: ItemsControl with scrollbar (ScrollViewer)

To get a scrollbar for an ItemsControl, you can host it in a ScrollViewer like this:

<ScrollViewer VerticalScrollBarVisibility="Auto">
  <ItemsControl>
    <uc:UcSpeler />
    <uc:UcSpeler />
    <uc:UcSpeler />
    <uc:UcSpeler />
    <uc:UcSpeler />
  </ItemsControl>
</ScrollViewer>

WPF TabItem Header Styling

While searching for a way to round tabs, I found Carlo's answer and it did help but I needed a bit more. Here is what I put together, based on his work. This was done with MS Visual Studio 2015.

The Code:

<Window x:Class="MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:MealNinja"
        mc:Ignorable="d"
        Title="Rounded Tabs Example" Height="550" Width="700" WindowStartupLocation="CenterScreen" FontFamily="DokChampa" FontSize="13.333" ResizeMode="CanMinimize" BorderThickness="0">
    <Window.Effect>
        <DropShadowEffect Opacity="0.5"/>
    </Window.Effect>
    <Grid Background="#FF423C3C">
        <TabControl x:Name="tabControl" TabStripPlacement="Left" Margin="6,10,10,10" BorderThickness="3">
            <TabControl.Resources>
                <Style TargetType="{x:Type TabItem}">
                    <Setter Property="Template">
                        <Setter.Value>
                            <ControlTemplate TargetType="{x:Type TabItem}">
                                <Grid>
                                    <Border Name="Border" Background="#FF6E6C67" Margin="2,2,-8,0" BorderBrush="Black" BorderThickness="1,1,1,1" CornerRadius="10">
                                        <ContentPresenter x:Name="ContentSite" ContentSource="Header" VerticalAlignment="Center" HorizontalAlignment="Center" Margin="2,2,12,2" RecognizesAccessKey="True"/>
                                    </Border>
                                    <Rectangle Height="100" Width="10" Margin="0,0,-10,0" Stroke="Black" VerticalAlignment="Bottom" HorizontalAlignment="Right" StrokeThickness="0" Fill="#FFD4D0C8"/>
                                </Grid>
                                <ControlTemplate.Triggers>
                                    <Trigger Property="IsSelected" Value="True">
                                        <Setter Property="FontWeight" Value="Bold" />
                                        <Setter TargetName="ContentSite" Property="Width" Value="30" />
                                        <Setter TargetName="Border" Property="Background" Value="#FFD4D0C8" />
                                    </Trigger>
                                    <Trigger Property="IsEnabled" Value="False">
                                        <Setter TargetName="Border" Property="Background" Value="#FF6E6C67" />
                                    </Trigger>
                                    <Trigger Property="IsMouseOver" Value="true">
                                        <Setter Property="FontWeight" Value="Bold" />
                                    </Trigger>
                                </ControlTemplate.Triggers>
                            </ControlTemplate>
                        </Setter.Value>
                    </Setter>
                    <Setter Property="HeaderTemplate">
                        <Setter.Value>
                            <DataTemplate>
                                <ContentPresenter Content="{TemplateBinding Content}">
                                    <ContentPresenter.LayoutTransform>
                                        <RotateTransform Angle="270" />
                                    </ContentPresenter.LayoutTransform>
                                </ContentPresenter>
                            </DataTemplate>
                        </Setter.Value>
                    </Setter>
                    <Setter Property="Background" Value="#FF6E6C67" />
                    <Setter Property="Height" Value="90" />
                    <Setter Property="Margin" Value="0" />
                    <Setter Property="Padding" Value="0" />
                    <Setter Property="FontFamily" Value="DokChampa" />
                    <Setter Property="FontSize" Value="16" />
                    <Setter Property="VerticalAlignment" Value="Top" />
                    <Setter Property="HorizontalAlignment" Value="Right" />
                    <Setter Property="UseLayoutRounding" Value="False" />
                </Style>
                <Style x:Key="tabGrids">
                    <Setter Property="Grid.Background" Value="#FFE5E5E5" />
                    <Setter Property="Grid.Margin" Value="6,10,10,10" />
                </Style>
            </TabControl.Resources>
            <TabItem Header="Planner">
                <Grid Style="{StaticResource tabGrids}"/>
            </TabItem>
            <TabItem Header="Section 2">
                <Grid Style="{StaticResource tabGrids}"/>
            </TabItem>
            <TabItem Header="Section III">
                <Grid Style="{StaticResource tabGrids}"/>
            </TabItem>
            <TabItem Header="Section 04">
                <Grid Style="{StaticResource tabGrids}"/>
            </TabItem>
            <TabItem Header="Tools">
                <Grid Style="{StaticResource tabGrids}"/>
            </TabItem>
        </TabControl>
    </Grid>
</Window>

Screenshot:

enter image description here

WPF TemplateBinding vs RelativeSource TemplatedParent

I thought TemplateBinding does not support Freezable types (which includes brush objects). To get around the problem. One can make use of TemplatedParent

How To Format A Block of Code Within a Presentation?

An on-line syntax highlighter:

http://markup.su/highlighter/

or

http://hilite.me/

Just copy and paste into your document.

What are MVP and MVC and what is the difference?

I have used both MVP and MVC and although we as developers tend to focus on the technical differences of both patterns the point for MVP in IMHO is much more related to ease of adoption than anything else.

If I’m working in a team that already as a good background on web forms development style it’s far easier to introduce MVP than MVC. I would say that MVP in this scenario is a quick win.

My experience tells me that moving a team from web forms to MVP and then from MVP to MVC is relatively easy; moving from web forms to MVC is more difficult.

I leave here a link to a series of articles a friend of mine has published about MVP and MVC.

http://www.qsoft.be/post/Building-the-MVP-StoreFront-Gutthrie-style.aspx

When should an Excel VBA variable be killed or set to Nothing?

VB6/VBA uses deterministic approach to destoying objects. Each object stores number of references to itself. When the number reaches zero, the object is destroyed.

Object variables are guaranteed to be cleaned (set to Nothing) when they go out of scope, this decrements the reference counters in their respective objects. No manual action required.

There are only two cases when you want an explicit cleanup:

  1. When you want an object to be destroyed before its variable goes out of scope (e.g., your procedure is going to take long time to execute, and the object holds a resource, so you want to destroy the object as soon as possible to release the resource).

  2. When you have a circular reference between two or more objects.

    If objectA stores a references to objectB, and objectB stores a reference to objectA, the two objects will never get destroyed unless you brake the chain by explicitly setting objectA.ReferenceToB = Nothing or objectB.ReferenceToA = Nothing.

The code snippet you show is wrong. No manual cleanup is required. It is even harmful to do a manual cleanup, as it gives you a false sense of more correct code.

If you have a variable at a class level, it will be cleaned/destroyed when the class instance is destructed. You can destroy it earlier if you want (see item 1.).

If you have a variable at a module level, it will be cleaned/destroyed when your program exits (or, in case of VBA, when the VBA project is reset). You can destroy it earlier if you want (see item 1.).

Access level of a variable (public vs. private) does not affect its life time.

Get string after character

Use parameter expansion, if the value is already stored in a variable.

$ str="GenFiltEff=7.092200e-01"
$ value=${str#*=}

Or use read

$ IFS="=" read name value <<< "GenFiltEff=7.092200e-01"

Either way,

$ echo $value
7.092200e-01

Can we instantiate an abstract class directly?

You can't directly instantiate an abstract class, but you can create an anonymous class when there is no concrete class:

public class AbstractTest {
    public static void main(final String... args) {
        final Printer p = new Printer() {
            void printSomethingOther() {
                System.out.println("other");
            }
            @Override
            public void print() {
                super.print();
                System.out.println("world");
                printSomethingOther(); // works fine
            }
        };
        p.print();
        //p.printSomethingOther(); // does not work
    }
}

abstract class Printer {
    public void print() {
        System.out.println("hello");
    }
}

This works with interfaces, too.

How to center body on a page?

    body
    {
        width:80%;
        margin-left:auto;
        margin-right:auto;
    }

This will work on most browsers, including IE.

Automatically get loop index in foreach loop in Perl

Not with foreach.

If you definitely need the element cardinality in the array, use a 'for' iterator:

for ($i=0; $i<@x; ++$i) {
  print "Element at index $i is " , $x[$i] , "\n";
}

How to fluently build JSON in Java?

If you are using Jackson do a lot of JsonNode building in code, you may be interesting in the following set of utilities. The benefit of using them is that they support a more natural chaining style that better shows the structure of the JSON under construction.

Here is an example usage:

import static JsonNodeBuilders.array;
import static JsonNodeBuilders.object;

...

val request = object("x", "1").with("y", array(object("z", "2"))).end();

Which is equivalent to the following JSON:

{"x":"1", "y": [{"z": "2"}]}

Here are the classes:

import static lombok.AccessLevel.PRIVATE;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.JsonNodeFactory;
import com.fasterxml.jackson.databind.node.ObjectNode;

import lombok.NoArgsConstructor;
import lombok.NonNull;
import lombok.RequiredArgsConstructor;
import lombok.val;

/**
 * Convenience {@link JsonNode} builder.
 */
@NoArgsConstructor(access = PRIVATE)
public final class JsonNodeBuilders {

  /**
   * Factory methods for an {@link ObjectNode} builder.
   */

  public static ObjectNodeBuilder object() {
    return object(JsonNodeFactory.instance);
  }

  public static ObjectNodeBuilder object(@NonNull String k1, boolean v1) {
    return object().with(k1, v1);
  }

  public static ObjectNodeBuilder object(@NonNull String k1, int v1) {
    return object().with(k1, v1);
  }

  public static ObjectNodeBuilder object(@NonNull String k1, float v1) {
    return object().with(k1, v1);
  }

  public static ObjectNodeBuilder object(@NonNull String k1, String v1) {
    return object().with(k1, v1);
  }

  public static ObjectNodeBuilder object(@NonNull String k1, String v1, @NonNull String k2, String v2) {
    return object(k1, v1).with(k2, v2);
  }

  public static ObjectNodeBuilder object(@NonNull String k1, String v1, @NonNull String k2, String v2,
      @NonNull String k3, String v3) {
    return object(k1, v1, k2, v2).with(k3, v3);
  }

  public static ObjectNodeBuilder object(@NonNull String k1, JsonNodeBuilder<?> builder) {
    return object().with(k1, builder);
  }

  public static ObjectNodeBuilder object(JsonNodeFactory factory) {
    return new ObjectNodeBuilder(factory);
  }

  /**
   * Factory methods for an {@link ArrayNode} builder.
   */

  public static ArrayNodeBuilder array() {
    return array(JsonNodeFactory.instance);
  }

  public static ArrayNodeBuilder array(@NonNull boolean... values) {
    return array().with(values);
  }

  public static ArrayNodeBuilder array(@NonNull int... values) {
    return array().with(values);
  }

  public static ArrayNodeBuilder array(@NonNull String... values) {
    return array().with(values);
  }

  public static ArrayNodeBuilder array(@NonNull JsonNodeBuilder<?>... builders) {
    return array().with(builders);
  }

  public static ArrayNodeBuilder array(JsonNodeFactory factory) {
    return new ArrayNodeBuilder(factory);
  }

  public interface JsonNodeBuilder<T extends JsonNode> {

    /**
     * Construct and return the {@link JsonNode} instance.
     */
    T end();

  }

  @RequiredArgsConstructor
  private static abstract class AbstractNodeBuilder<T extends JsonNode> implements JsonNodeBuilder<T> {

    /**
     * The source of values.
     */
    @NonNull
    protected final JsonNodeFactory factory;

    /**
     * The value under construction.
     */
    @NonNull
    protected final T node;

    /**
     * Returns a valid JSON string, so long as {@code POJONode}s not used.
     */
    @Override
    public String toString() {
      return node.toString();
    }

  }

  public final static class ObjectNodeBuilder extends AbstractNodeBuilder<ObjectNode> {

    private ObjectNodeBuilder(JsonNodeFactory factory) {
      super(factory, factory.objectNode());
    }

    public ObjectNodeBuilder withNull(@NonNull String field) {
      return with(field, factory.nullNode());
    }

    public ObjectNodeBuilder with(@NonNull String field, int value) {
      return with(field, factory.numberNode(value));
    }

    public ObjectNodeBuilder with(@NonNull String field, float value) {
      return with(field, factory.numberNode(value));
    }

    public ObjectNodeBuilder with(@NonNull String field, boolean value) {
      return with(field, factory.booleanNode(value));
    }

    public ObjectNodeBuilder with(@NonNull String field, String value) {
      return with(field, factory.textNode(value));
    }

    public ObjectNodeBuilder with(@NonNull String field, JsonNode value) {
      node.set(field, value);
      return this;
    }

    public ObjectNodeBuilder with(@NonNull String field, @NonNull JsonNodeBuilder<?> builder) {
      return with(field, builder.end());
    }

    public ObjectNodeBuilder withPOJO(@NonNull String field, @NonNull Object pojo) {
      return with(field, factory.pojoNode(pojo));
    }

    @Override
    public ObjectNode end() {
      return node;
    }

  }

  public final static class ArrayNodeBuilder extends AbstractNodeBuilder<ArrayNode> {

    private ArrayNodeBuilder(JsonNodeFactory factory) {
      super(factory, factory.arrayNode());
    }

    public ArrayNodeBuilder with(boolean value) {
      node.add(value);
      return this;
    }

    public ArrayNodeBuilder with(@NonNull boolean... values) {
      for (val value : values)
        with(value);
      return this;
    }

    public ArrayNodeBuilder with(int value) {
      node.add(value);
      return this;
    }

    public ArrayNodeBuilder with(@NonNull int... values) {
      for (val value : values)
        with(value);
      return this;
    }

    public ArrayNodeBuilder with(float value) {
      node.add(value);
      return this;
    }

    public ArrayNodeBuilder with(String value) {
      node.add(value);
      return this;
    }

    public ArrayNodeBuilder with(@NonNull String... values) {
      for (val value : values)
        with(value);
      return this;
    }

    public ArrayNodeBuilder with(@NonNull Iterable<String> values) {
      for (val value : values)
        with(value);
      return this;
    }

    public ArrayNodeBuilder with(JsonNode value) {
      node.add(value);
      return this;
    }

    public ArrayNodeBuilder with(@NonNull JsonNode... values) {
      for (val value : values)
        with(value);
      return this;
    }

    public ArrayNodeBuilder with(JsonNodeBuilder<?> value) {
      return with(value.end());
    }

    public ArrayNodeBuilder with(@NonNull JsonNodeBuilder<?>... builders) {
      for (val builder : builders)
        with(builder);
      return this;
    }

    @Override
    public ArrayNode end() {
      return node;
    }

  }

}

Note that the implementation uses Lombok, but you can easily desugar it to fill in the Java boilerplate.

Disable button in WPF?

By code:

btn_edit.IsEnabled = true;

By XAML:

<Button Content="Edit data" Grid.Column="1" Name="btn_edit" Grid.Row="1" IsEnabled="False" />

Full screen background image in an activity

If you want your image to show BEHIND a transparent Action Bar, put the following into your Theme's style definition:

<item name="android:windowActionBarOverlay">true</item>

Enjoy!

I want to delete all bin and obj folders to force all projects to rebuild everything

To delete bin and obj before build add to project file:

<Target Name="BeforeBuild">
    <!-- Remove obj folder -->
    <RemoveDir Directories="$(BaseIntermediateOutputPath)" />
    <!-- Remove bin folder -->
    <RemoveDir Directories="$(BaseOutputPath)" />
</Target>

Here is article: How to remove bin and/or obj folder before the build or deploy

Auto increment in phpmyadmin

(a)Simply click on your database, select your table. Click on 'Operations'. Under the 'table options' section change the AUTO_INCREMENT value to your desired value, in this case: 10000 the click 'Go'. (See the image attached)

(b)Alternatively, you can run a SQL command under the SQL tab after selecting your table. Simply type 'ALTER TABLE table_name AUTO_INCREMENT = 10000;' then click 'Go'. That's it!! SETTING AUTO INCREMENT VALUE image(a)

SETTING AUTO INCREMENT VALUE image(B)

What is the easiest way to clear a database from the CLI with manage.py in Django?

Using Django Extensions, running:

./manage.py reset_db

Will clear the database tables, then running:

./manage.py syncdb

Will recreate them (south may ask you to migrate things).

What tools do you use to test your public REST API?

If you're just testing your APIs manually, we've found RestClient 2.3 or the Poster add-on for Firefox to be pretty helpful. Both of these let you build requests that GET, PUT, POST, or DELETE. You can save these requests to rerun later.

For simple automated testing try the Linux (or Cygwin) 'curl' command in a shell script.

From something more industrial strength you can move up to Apache JMeter. JMeter is great for load testing.

31 October 2014: HTTPRequester is now a better choice for Firefox.

July 2015: Postman is a good choice for Chrome

how to set the query timeout from SQL connection string

Only from code:

_x000D_
_x000D_
namespace xxx.DsXxxTableAdapters {_x000D_
    partial class ZzzTableAdapter_x000D_
    {_x000D_
        public void SetTimeout(int timeout)_x000D_
        {_x000D_
            if (this.Adapter.DeleteCommand != null) { this.Adapter.DeleteCommand.CommandTimeout = timeout; }_x000D_
            if (this.Adapter.InsertCommand != null) { this.Adapter.InsertCommand.CommandTimeout = timeout; }_x000D_
            if (this.Adapter.UpdateCommand != null) { this.Adapter.UpdateCommand.CommandTimeout = timeout; }_x000D_
            if (this._commandCollection == null) { this.InitCommandCollection(); }_x000D_
            if (this._commandCollection != null)_x000D_
            {_x000D_
                foreach (System.Data.SqlClient.SqlCommand item in this._commandCollection)_x000D_
                {_x000D_
                    if (item != null)_x000D_
                    { item.CommandTimeout = timeout; }_x000D_
                }_x000D_
            }_x000D_
        }_x000D_
    }_x000D_
 _x000D_
    //...._x000D_
 _x000D_
 }
_x000D_
_x000D_
_x000D_

javax.net.ssl.SSLHandshakeException: Remote host closed connection during handshake during web service communicaiton

Java 7 defaults to TLS 1.0, which can cause this error when that protocol is not accepted. I ran into this problem with a Tomcat application and a server that would not accept TLS 1.0 connections any longer. I added

-Dhttps.protocols=TLSv1.1,TLSv1.2

to the Java options and that fixed it. (Tomcat was running Java 7.)

PHP CURL DELETE request

switch ($method) {
    case "GET":
        curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "GET");
        break;
    case "POST":
        curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "POST");
        break;
    case "PUT":
        curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "PUT");
        break;
    case "DELETE":
        curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "DELETE"); 
        break;
}

Correct way to handle conditional styling in React

 <div style={{ visibility: this.state.driverDetails.firstName != undefined? 'visible': 'hidden'}}></div>

Checkout the above code. That will do the trick.

nodejs mongodb object id to string

function encodeToken(token){
    //token must be a string .
    token = typeof token == 'string' ? token : String(token)
}

User.findOne({name: 'elrrrrrrr'}, function(err, it) {
    encodeToken(it._id)
})

In mongoose , the objectId is an object (console.log(typeof it._id)).

ReferenceError: document is not defined (in plain JavaScript)

Try adding the script element just before the /body tag like that

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <link rel="stylesheet" type="text/css" href="css/quiz.css" />
</head>
<body>

    <div id="divid">Next</div>
    <script type="text/javascript" src="js/quiz.js"></script>
</body>
</html>

Using grep to search for a string that has a dot in it

You can escape the dot and other special characters using \

eg. grep -r "0\.49"

PHP session handling errors

you have to change your session.save_path setting to the accessible dir, /tmp/ for example

How to change: http://php.net/session_save_path

Being on the shared host, it is advised to set your session save path inside of your home directory but below document root

also note that

  • using ob_start is unnecessary here,
  • and I am sure you put @ operator by accident and already going to remove it forever, don't you?

Should I test private methods or only public ones?

I understand the point of view where private methods are considered as implementations details and then don't have to be tested. And I would stick with this rule if we had to develop outside of the object only. But us, are we some kind of restricted developers who are developing only outside of objects, calling only their public methods? Or are we actually also developing that object? As we are not bound to program outside objects, we will probably have to call those private methods into new public ones we are developing. Wouldn't it be great to know that the private method resist against all odds?

I know some people could answer that if we are developing another public method into that object then this one should be tested and that's it (the private method could carry on living without test). But this is also true for any public methods of an object: when developing a web app, all the public methods of an object are called from controllers methods and hence could be considered as implementation details for controllers.

So why are we unit testing objects? Because it is really difficult, not to say impossible to be sure that we are testing the controllers' methods with the appropriate input which will trigger all the branches of the underlying code. In other words, the higher we are in the stack, the more difficult it is to test all the behaviour. And so is the same for private methods.

To me the frontier between private and public methods is a psychologic criteria when it comes to tests. Criteria which matters more to me are:

  • is the method called more than once from different places?
  • is the method sophisticated enough to require tests?

How to use pip with python 3.4 on windows?

Assuming you don't have any other Python installations, you should be able to do python -m pip after a default installation. Something like the following should be in your system path:

C:\Python34\Scripts

This would obviously be different, if you installed Python in a different location.

jquery find class and get the value

You can also get the value by the following way

$(document).ready(function(){
  $("#start").click(function(){
    alert($(this).find("input[class='myClass']").val());
  });
});

Hive Alter table change Column Name

Change Column Name/Type/Position/Comment:

ALTER TABLE table_name CHANGE [COLUMN] col_old_name col_new_name column_type [COMMENT col_comment] [FIRST|AFTER column_name]

Example:

CREATE TABLE test_change (a int, b int, c int);

// will change column a's name to a1
ALTER TABLE test_change CHANGE a a1 INT;

Check if element is in the list (contains)

Use std::find, something like:

if (std::find(std::begin(my_list), std::end(my_list), my_var) != std::end(my_list))
    // my_list has my_var

Get current application physical path within Application_Start

 protected void Application_Start(object sender, EventArgs e)
 {
     string path = Server.MapPath("/");
     //or 
     string path2 = Server.MapPath("~");
     //depends on your application needs

 }

Check if argparse optional argument is set or not

If your argument is positional (ie it doesn't have a "-" or a "--" prefix, just the argument, typically a file name) then you can use the nargs parameter to do this:

parser = argparse.ArgumentParser(description='Foo is a program that does things')
parser.add_argument('filename', nargs='?')
args = parser.parse_args()

if args.filename is not None:
    print('The file name is {}'.format(args.filename))
else:
    print('Oh well ; No args, no problems')

Convert date to datetime in Python

The accepted answer is correct, but I would prefer to avoid using datetime.min.time() because it's not obvious to me exactly what it does. If it's obvious to you, then more power to you. I also feel the same way about the timetuple method and the reliance on the ordering.

In my opinion, the most readable, explicit way of doing this without relying on the reader to be very familiar with the datetime module API is:

from datetime import date, datetime
today = date.today()
today_with_time = datetime(
    year=today.year, 
    month=today.month,
    day=today.day,
)

That's my take on "explicit is better than implicit."

How to supply value to an annotation from a Constant java

Compile constants can only be primitives and Strings:

15.28. Constant Expressions

A compile-time constant expression is an expression denoting a value of primitive type or a String that does not complete abruptly and is composed using only the following:

  • Literals of primitive type and literals of type String
  • Casts to primitive types and casts to type String
  • [...] operators [...]
  • Parenthesized expressions whose contained expression is a constant expression.
  • Simple names that refer to constant variables.
  • Qualified names of the form TypeName . Identifier that refer to constant variables.

Actually in java there is no way to protect items in an array. At runtime someone can always do FieldValues.FIELD1[0]="value3", therefore the array cannot be really constant if we look deeper.

Where can I get a virtual machine online?

koding.com has a free VM running Ubuntu. The specs are pretty good, 1 gig memory for example. They have a terminal online you can access through their website, or use SSH. The VM will go to sleep approximately 20 minutes after you log out. The reason is to discourage users from running live production code on the VM. The VM resides behind a proxy. Running web servers that only speak HTTP (port 80) should work just fine, but I think you'll get into a lot of trouble whenever you want to work directly with other ports. Many mind-like alternatives offer similar setups. Good luck!

I had the same idea as you but given all restrictions everybody keep imposing everywhere I feel that I must go out and pay for a VPS.

How do I run a PowerShell script when the computer starts?

This is really just an expansion on @mjolinor simple answer [Use Task Scheduler].

I knew "Task Scheduler" was the correct way, but it took a bit of effort to get it running the way I wanted and thought I'd post my finding for others.

Issues including:

  • Redirecting output to logs
  • Hiding the PowerShell window

Note: You must have permission to run script see ExecutionPolicy

Then in Task Scheduler, the most important/tricky part is the Action

It should be Start a Program

Program/Script:

powershell

Add arguments (optional) :

-windowstyle hidden -command full\path\script.ps1 >> "%TEMP%\StartupLog.txt" 2>&1

Note:

If you see -File on the internet, it will work, but understand nothing can be after -File except the File Path, IE: The redirect is taken to be part of the file path and it fails, you must use -command in conjunction with redirect, but you can prepend additional commands/arguments such as -windowstyle hidden to not show PowerShell window.

I had to adjust all Write-Host to Write-Output in my script as well.

COUNT DISTINCT with CONDITIONS

You can try this:

select
  count(distinct tag) as tag_count,
  count(distinct (case when entryId > 0 then tag end)) as positive_tag_count
from
  your_table_name;

The first count(distinct...) is easy. The second one, looks somewhat complex, is actually the same as the first one, except that you use case...when clause. In the case...when clause, you filter only positive values. Zeros or negative values would be evaluated as null and won't be included in count.

One thing to note here is that this can be done by reading the table once. When it seems that you have to read the same table twice or more, it can actually be done by reading once, in most of the time. As a result, it will finish the task a lot faster with less I/O.

combining results of two select statements

While it is possible to combine the results, I would advise against doing so.

You have two fundamentally different types of queries that return a different number of rows, a different number of columns and different types of data. It would be best to leave it as it is - two separate queries.

How to import an excel file in to a MySQL database

Step 1 Create Your CSV file

Step 2 log in to your mysql server

     mysql -uroot -pyourpassword 

Step 3 load your csv file

     load data local infile '//home/my-sys/my-excel.csv' into table my_tables fields terminated by ',' enclosed by '"' (Country, Amount,Qty);

Fixing the order of facets in ggplot

Make your size a factor in your dataframe by:

temp$size_f = factor(temp$size, levels=c('50%','100%','150%','200%'))

Then change the facet_grid(.~size) to facet_grid(.~size_f)

Then plot: enter image description here

The graphs are now in the correct order.

How can I increment a date by one day in Java?

SimpleDateFormat dateFormat = new SimpleDateFormat( "yyyy-MM-dd" );
Calendar cal = Calendar.getInstance();
cal.setTime( dateFormat.parse( inputString ) );
cal.add( Calendar.DATE, 1 );

What does %~d0 mean in a Windows batch file?

Yes, There are other shortcuts that you can use which are given below. In your command, ~d0 would mean the drive letter of the 0th argument.

~ expands the given variable
d gets the drive letter only
0 is the argument you are referencing

As the 0th argument is the script path, it gets the drive letter of the path for you. You can use the following shortcuts too.

%~1         - expands %1 removing any surrounding quotes (")
%~f1        - expands %1 to a fully qualified path name
%~d1        - expands %1 to a drive letter only
%~p1        - expands %1 to a path only
%~n1        - expands %1 to a file name only
%~x1        - expands %1 to a file extension only
%~s1        - expanded path contains short names only
%~a1        - expands %1 to file attributes
%~t1        - expands %1 to date/time of file
%~z1        - expands %1 to size of file
%~$PATH:1   - searches the directories listed in the PATH
               environment variable and expands %1 to the fully
               qualified name of the first one found.  If the
               environment variable name is not defined or the
               file is not found by the search, then this
               modifier expands to the empty string    

%~dp1       - expands %1 to a drive letter and path only
%~nx1       - expands %1 to a file name and extension only
%~dp$PATH:1 - searches the directories listed in the PATH
               environment variable for %1 and expands to the
               drive letter and path of the first one found.
%~ftza1     - expands %1 to a DIR like output line

This can be also found directly in command prompt when you run CALL /? or FOR /?

Python: IndexError: list index out of range

I think you mean to put the rolling of the random a,b,c, etc within the loop:

a = None # initialise
while not (a in winning_numbers):
    # keep rolling an a until you get one not in winning_numbers
    a = random.randint(1,30)
    winning_numbers.append(a)

Otherwise, a will be generated just once, and if it is in winning_numbers already, it won't be added. Since the generation of a is outside the while (in your code), if a is already in winning_numbers then too bad, it won't be re-rolled, and you'll have one less winning number.

That could be what causes your error in if guess[i] == winning_numbers[i]. (Your winning_numbers isn't always of length 5).

Scrolling a div with jQuery

Relatively-position your content div within a parent div having overflow:hidden. Make your up/down arrows move the top value of the content div. The following jQuery is untested. Let me know if you require any further assistance with it as a concept.

div.container {
  overflow:hidden;
  width:200px;
  height:200px;
}
div.content {
  position:relative;
  top:0;
}

<div class="container">
  <p>
    <a href="enablejs.html" class="up">Up</a> / 
    <a href="enablejs.html" class="dn">Down</a>
  </p>
  <div class="content">
    <p>Hello World</p>
  </div>
</div>

$(function(){
  $(".container a.up").bind("click", function(){
    var topVal = $(this).parents(".container").find(".content").css("top");
    $(this).parents(".container").find(".content").css("top", topVal-10);
  });

  $(".container a.dn").bind("click", function(){
    var topVal = $(this).parents(".container").find(".content").css("top");
    $(this).parents(".container").find(".content").css("top", topVal+10);
  });
});

How to control the width and height of the default Alert Dialog in Android?

I dont know whether you can change the default height/width of AlertDialog but if you wanted to do this, I think you can do it by creating your own custom dialog. You just have to give android:theme="@android:style/Theme.Dialog" in the android manifest.xml for your activity and can write the whole layout as per your requirement. you can set the height and width of your custom dialog from the Android Resource XML.

How do I remove a specific element from a JSONArray?

We can use iterator to filter out the array entries instead of creating a new  Array. 

'public static void removeNullsFrom(JSONArray array) throws JSONException {
                if (array != null) {
                    Iterator<Object> iterator = array.iterator();
                    while (iterator.hasNext()) {
                        Object o = iterator.next();
                        if (o == null || o == JSONObject.NULL) {
                            iterator.remove();
                        }
                    }
                }
            }'

How do you convert a DataTable into a generic list?

If you're using .NET 3.5, you can use DataTableExtensions.AsEnumerable (an extension method) and then if you really need a List<DataRow> instead of just IEnumerable<DataRow> you can call Enumerable.ToList:

IEnumerable<DataRow> sequence = dt.AsEnumerable();

or

using System.Linq;
...
List<DataRow> list = dt.AsEnumerable().ToList();

Subtracting 1 day from a timestamp date

Use the INTERVAL type to it. E.g:

--yesterday
SELECT NOW() - INTERVAL '1 DAY';

--Unrelated to the question, but PostgreSQL also supports some shortcuts:
SELECT 'yesterday'::TIMESTAMP, 'tomorrow'::TIMESTAMP, 'allballs'::TIME;

Then you can do the following on your query:

SELECT 
    org_id,
    count(accounts) AS COUNT,
    ((date_at) - INTERVAL '1 DAY') AS dateat
FROM 
    sourcetable
WHERE 
    date_at <= now() - INTERVAL '130 DAYS'
GROUP BY 
    org_id,
    dateat;


TIPS

Tip 1

You can append multiple operands. E.g.: how to get last day of current month?

SELECT date_trunc('MONTH', CURRENT_DATE) + INTERVAL '1 MONTH - 1 DAY';

Tip 2

You can also create an interval using make_interval function, useful when you need to create it at runtime (not using literals):

SELECT make_interval(days => 10 + 2);
SELECT make_interval(days => 1, hours => 2);
SELECT make_interval(0, 1, 0, 5, 0, 0, 0.0);


More info:

Date/Time Functions and Operators

datatype-datetime (Especial values).

Commenting multiple lines in DOS batch file

Another option is to enclose the unwanted lines in an IF block that can never be true

if 1==0 (
...
)

Of course nothing within the if block will be executed, but it will be parsed. So you can't have any invalid syntax within. Also, the comment cannot contain ) unless it is escaped or quoted. For those reasons the accepted GOTO solution is more reliable. (The GOTO solution may also be faster)

Update 2017-09-19

Here is a cosmetic enhancement to pdub's GOTO solution. I define a simple environment variable "macro" that makes the GOTO comment syntax a bit better self documenting. Although it is generally recommended that :labels are unique within a batch script, it really is OK to embed multiple comments like this within the same batch script.

@echo off
setlocal

set "beginComment=goto :endComment"

%beginComment%
Multi-line comment 1
goes here
:endComment

echo This code executes

%beginComment%
Multi-line comment 2
goes here
:endComment

echo Done

Or you could use one of these variants of npocmaka's solution. The use of REM instead of BREAK makes the intent a bit clearer.

rem.||(
   remarks
   go here
)

rem^ ||(
   The space after the caret
   is critical
)

TypeScript-'s Angular Framework Error - "There is no directive with exportAs set to ngForm"

In addition to import the form module in login component ts file you need to import NgForm also.

import { NgForm } from '@angular/forms';

This resolved my issue

What and When to use Tuple?

This msdn article explains it very well with examples, "A tuple is a data structure that has a specific number and sequence of elements".

Tuples are commonly used in four ways:

  1. To represent a single set of data. For example, a tuple can represent a database record, and its components can represent individual fields of the record.

  2. To provide easy access to, and manipulation of, a data set.

  3. To return multiple values from a method without using out parameters (in C#) or ByRef parameters (in Visual Basic).

  4. To pass multiple values to a method through a single parameter. For example, the Thread.Start(Object) method has a single parameter that lets you supply one value to the method that the thread executes at startup time. If you supply a Tuple<T1, T2, T3> object as the method argument, you can supply the thread’s startup routine with three items of data.

Undefined symbols for architecture i386

A bit late to the party but might be valuable to someone with this error..

I just straight copied a bunch of files into an Xcode project, if you forget to add them to your projects Build Phases you will get the error "Undefined symbols for architecture i386". So add your implementation files to Compile Sources, and Xib files to Copy Bundle Resources.

The error was telling me that there was no link to my classes simply because they weren't included in the Compile Sources, quite obvious really but may save someone a headache.

Convert object to JSON string in C#

Use .net inbuilt class JavaScriptSerializer

  JavaScriptSerializer js = new JavaScriptSerializer();
  string json = js.Serialize(obj);

use "netsh wlan set hostednetwork ..." to create a wifi hotspot and the authentication can't work correctly

I am using Windows 10 Home edition.

I tried various combination,

netsh wlan show drivers
netsh wlan show hostednetwork
netsh wlan set hostednetwork mode=allow ssid=happy key=12345678
netsh wlan start hostednetwork

and also,

Control Panel\Network and Internet\Network Connections\Ethernet Properties\Sharing\Internet Connection Sharing\Allow other network users to connect through this computer Internet connection...

But still cannot activate WiFi hotspot.

While I have given up, somehow I click on Network icon on the taskbar, suddenly I see the buttons:

[ Wi-Fi ] [ Airplane Mode ] [ Mobile hotspot ]

Just like how our mobile phone can enable Mobile hotspot, Windows 10 has Mobile hotspot build-in. Just click on [ Mobile hotspot ] button and it works.

How to match a line not containing a word

This should work:

/^((?!PART).)*$/

If you only wanted to exclude it from the beginning of the line (I know you don't, but just FYI), you could use this:

/^(?!PART)/

Edit (by request): Why this pattern works

The (?!...) syntax is a negative lookahead, which I've always found tough to explain. Basically, it means "whatever follows this point must not match the regular expression /PART/." The site I've linked explains this far better than I can, but I'll try to break this down:

^         #Start matching from the beginning of the string.    
(?!PART)  #This position must not be followed by the string "PART".
.         #Matches any character except line breaks (it will include those in single-line mode).
$         #Match all the way until the end of the string.

The ((?!xxx).)* idiom is probably hardest to understand. As we saw, (?!PART) looks at the string ahead and says that whatever comes next can't match the subpattern /PART/. So what we're doing with ((?!xxx).)* is going through the string letter by letter and applying the rule to all of them. Each character can be anything, but if you take that character and the next few characters after it, you'd better not get the word PART.

The ^ and $ anchors are there to demand that the rule be applied to the entire string, from beginning to end. Without those anchors, any piece of the string that didn't begin with PART would be a match. Even PART itself would have matches in it, because (for example) the letter A isn't followed by the exact string PART.

Since we do have ^ and $, if PART were anywhere in the string, one of the characters would match (?=PART). and the overall match would fail. Hope that's clear enough to be helpful.

Is it possible to get multiple values from a subquery?

In Oracle query

select a.x
            ,(select b.y || ',' || b.z
                from   b
                where  b.v = a.v
                and    rownum = 1) as multple_columns
from   a

can be transformed to:

select a.x, b1.y, b1.z
from   a, b b1
where  b1.rowid = (
       select b.rowid
       from   b
       where  b.v = a.v
       and    rownum = 1
)

Is useful when we want to prevent duplication for table A. Similarly, we can increase the number of tables:

.... where (b1.rowid,c1.rowid) = (select b.rowid,c.rowid ....

Print array elements on separate lines in Bash?

Try doing this :

$ printf '%s\n' "${my_array[@]}"

The difference between $@ and $*:

  • Unquoted, the results are unspecified. In Bash, both expand to separate args and then wordsplit and globbed.

  • Quoted, "$@" expands each element as a separate argument, while "$*" expands to the args merged into one argument: "$1c$2c..." (where c is the first char of IFS).

You almost always want "$@". Same goes for "${arr[@]}".

Always quote them!

Windows Bat file optional argument parsing

The selected answer works, but it could use some improvement.

  • The options should probably be initialized to default values.
  • It would be nice to preserve %0 as well as the required args %1 and %2.
  • It becomes a pain to have an IF block for every option, especially as the number of options grows.
  • It would be nice to have a simple and concise way to quickly define all options and defaults in one place.
  • It would be good to support stand-alone options that serve as flags (no value following the option).
  • We don't know if an arg is enclosed in quotes. Nor do we know if an arg value was passed using escaped characters. Better to access an arg using %~1 and enclose the assignment within quotes. Then the batch can rely on the absence of enclosing quotes, but special characters are still generally safe without escaping. (This is not bullet proof, but it handles most situations)

My solution relies on the creation of an OPTIONS variable that defines all of the options and their defaults. OPTIONS is also used to test whether a supplied option is valid. A tremendous amount of code is saved by simply storing the option values in variables named the same as the option. The amount of code is constant regardless of how many options are defined; only the OPTIONS definition has to change.

EDIT - Also, the :loop code must change if the number of mandatory positional arguments changes. For example, often times all arguments are named, in which case you want to parse arguments beginning at position 1 instead of 3. So within the :loop, all 3 become 1, and 4 becomes 2.

@echo off
setlocal enableDelayedExpansion

:: Define the option names along with default values, using a <space>
:: delimiter between options. I'm using some generic option names, but 
:: normally each option would have a meaningful name.
::
:: Each option has the format -name:[default]
::
:: The option names are NOT case sensitive.
::
:: Options that have a default value expect the subsequent command line
:: argument to contain the value. If the option is not provided then the
:: option is set to the default. If the default contains spaces, contains
:: special characters, or starts with a colon, then it should be enclosed
:: within double quotes. The default can be undefined by specifying the
:: default as empty quotes "".
:: NOTE - defaults cannot contain * or ? with this solution.
::
:: Options that are specified without any default value are simply flags
:: that are either defined or undefined. All flags start out undefined by
:: default and become defined if the option is supplied.
::
:: The order of the definitions is not important.
::
set "options=-username:/ -option2:"" -option3:"three word default" -flag1: -flag2:"

:: Set the default option values
for %%O in (%options%) do for /f "tokens=1,* delims=:" %%A in ("%%O") do set "%%A=%%~B"

:loop
:: Validate and store the options, one at a time, using a loop.
:: Options start at arg 3 in this example. Each SHIFT is done starting at
:: the first option so required args are preserved.
::
if not "%~3"=="" (
  set "test=!options:*%~3:=! "
  if "!test!"=="!options! " (
    rem No substitution was made so this is an invalid option.
    rem Error handling goes here.
    rem I will simply echo an error message.
    echo Error: Invalid option %~3
  ) else if "!test:~0,1!"==" " (
    rem Set the flag option using the option name.
    rem The value doesn't matter, it just needs to be defined.
    set "%~3=1"
  ) else (
    rem Set the option value using the option as the name.
    rem and the next arg as the value
    set "%~3=%~4"
    shift /3
  )
  shift /3
  goto :loop
)

:: Now all supplied options are stored in variables whose names are the
:: option names. Missing options have the default value, or are undefined if
:: there is no default.
:: The required args are still available in %1 and %2 (and %0 is also preserved)
:: For this example I will simply echo all the option values,
:: assuming any variable starting with - is an option.
::
set -

:: To get the value of a single parameter, just remember to include the `-`
echo The value of -username is: !-username!

There really isn't that much code. Most of the code above is comments. Here is the exact same code, without the comments.

@echo off
setlocal enableDelayedExpansion

set "options=-username:/ -option2:"" -option3:"three word default" -flag1: -flag2:"

for %%O in (%options%) do for /f "tokens=1,* delims=:" %%A in ("%%O") do set "%%A=%%~B"
:loop
if not "%~3"=="" (
  set "test=!options:*%~3:=! "
  if "!test!"=="!options! " (
      echo Error: Invalid option %~3
  ) else if "!test:~0,1!"==" " (
      set "%~3=1"
  ) else (
      set "%~3=%~4"
      shift /3
  )
  shift /3
  goto :loop
)
set -

:: To get the value of a single parameter, just remember to include the `-`
echo The value of -username is: !-username!


This solution provides Unix style arguments within a Windows batch. This is not the norm for Windows - batch usually has the options preceding the required arguments and the options are prefixed with /.

The techniques used in this solution are easily adapted for a Windows style of options.

  • The parsing loop always looks for an option at %1, and it continues until arg 1 does not begin with /
  • Note that SET assignments must be enclosed within quotes if the name begins with /.
    SET /VAR=VALUE fails
    SET "/VAR=VALUE" works. I am already doing this in my solution anyway.
  • The standard Windows style precludes the possibility of the first required argument value starting with /. This limitation can be eliminated by employing an implicitly defined // option that serves as a signal to exit the option parsing loop. Nothing would be stored for the // "option".


Update 2015-12-28: Support for ! in option values

In the code above, each argument is expanded while delayed expansion is enabled, which means that ! are most likely stripped, or else something like !var! is expanded. In addition, ^ can also be stripped if ! is present. The following small modification to the un-commented code removes the limitation such that ! and ^ are preserved in option values.

@echo off
setlocal enableDelayedExpansion

set "options=-username:/ -option2:"" -option3:"three word default" -flag1: -flag2:"

for %%O in (%options%) do for /f "tokens=1,* delims=:" %%A in ("%%O") do set "%%A=%%~B"
:loop
if not "%~3"=="" (
  set "test=!options:*%~3:=! "
  if "!test!"=="!options! " (
      echo Error: Invalid option %~3
  ) else if "!test:~0,1!"==" " (
      set "%~3=1"
  ) else (
      setlocal disableDelayedExpansion
      set "val=%~4"
      call :escapeVal
      setlocal enableDelayedExpansion
      for /f delims^=^ eol^= %%A in ("!val!") do endlocal&endlocal&set "%~3=%%A" !
      shift /3
  )
  shift /3
  goto :loop
)
goto :endArgs
:escapeVal
set "val=%val:^=^^%"
set "val=%val:!=^!%"
exit /b
:endArgs

set -

:: To get the value of a single parameter, just remember to include the `-`
echo The value of -username is: !-username!

SyntaxError: unexpected EOF while parsing

You're missing a closing parenthesis ) in print():

print('{0}+{1}={2}'.format(n1,n2,t1))

and you're also not storing the returned value from int(), so z is still a string.

z = input('?')
z = int(z)

or simply:

z = int(input('?'))

How to Make A Chevron Arrow Using CSS?

Here's a different approach:

1) Use the multiplication character: &times; ×

2) Hide half of it with overflow:hidden

3) Then add a triangle as a pseudo element for the tip.

The advantage here is that no transforms are necessary. (It will work in IE8+)

FIDDLE

_x000D_
_x000D_
.arrow {_x000D_
  position: relative;_x000D_
}_x000D_
.arrow:before {_x000D_
  content: '×';_x000D_
  display: inline-block;_x000D_
  position: absolute;_x000D_
  font-size: 240px;_x000D_
  font-weight: bold;_x000D_
  font-family: verdana;_x000D_
  width: 103px;_x000D_
  height: 151px;_x000D_
  overflow: hidden;_x000D_
  line-height: 117px;_x000D_
}_x000D_
.arrow:after {_x000D_
  content: '';_x000D_
  display: inline-block;_x000D_
  position: absolute;_x000D_
  left: 101px;_x000D_
  top: 51px;_x000D_
  width: 0;_x000D_
  height: 0;_x000D_
  border-style: solid;_x000D_
  border-width: 25px 0 25px 24px;_x000D_
  border-color: transparent transparent transparent black;_x000D_
}
_x000D_
<div class="arrow"></div>
_x000D_
_x000D_
_x000D_

Oracle - Insert New Row with Auto Incremental ID

There is no built-in auto_increment in Oracle.

You need to use sequences and triggers.

Read here how to do it right. (Step-by-step how-to for "Creating auto-increment columns in Oracle")

Delete statement in SQL is very slow

Check execution plan of this delete statement. Have a look if index seek is used. Also what is data type of col?

If you are using wrong data type, change update statement (like from '1' to 1 or N'1').

If index scan is used consider using some query hint..

How to get json key and value in javascript?

http://jsfiddle.net/v8aWF/

Worked out a fiddle. Do check it out

(function() {
    var oJson = {
        "name": "", 
        "skills": "", 
        "jobtitle": "Entwickler", 
        "res_linkedin": "GwebSearch"
    }
    alert(oJson.jobtitle);
})();

How to load all modules in a folder?

Update in 2017: you probably want to use importlib instead.

Make the Foo directory a package by adding an __init__.py. In that __init__.py add:

import bar
import eggs
import spam

Since you want it dynamic (which may or may not be a good idea), list all py-files with list dir and import them with something like this:

import os
for module in os.listdir(os.path.dirname(__file__)):
    if module == '__init__.py' or module[-3:] != '.py':
        continue
    __import__(module[:-3], locals(), globals())
del module

Then, from your code do this:

import Foo

You can now access the modules with

Foo.bar
Foo.eggs
Foo.spam

etc. from Foo import * is not a good idea for several reasons, including name clashes and making it hard to analyze the code.

Setting dynamic scope variables in AngularJs - scope.<some_string>

If you were trying to do what I imagine you were trying to do, then you only have to treat scope like a regular JS object.

This is what I use for an API success response for JSON data array...

function(data){

    $scope.subjects = [];

    $.each(data, function(i,subject){
        //Store array of data types
        $scope.subjects.push(subject.name);

        //Split data in to arrays
        $scope[subject.name] = subject.data;
    });
}

Now {{subjects}} will return an array of data subject names, and in my example there would be a scope attribute for {{jobs}}, {{customers}}, {{staff}}, etc. from $scope.jobs, $scope.customers, $scope.staff

How to change the background colour's opacity in CSS

Use RGB values combined with opacity to get the transparency that you wish.

For instance,

<div style=" background: rgb(255, 0, 0) ; opacity: 0.2;">&nbsp;</div>
<div style=" background: rgb(255, 0, 0) ; opacity: 0.4;">&nbsp;</div>
<div style=" background: rgb(255, 0, 0) ; opacity: 0.6;">&nbsp;</div>
<div style=" background: rgb(255, 0, 0) ; opacity: 0.8;">&nbsp;</div>
<div style=" background: rgb(255, 0, 0) ; opacity: 1;">&nbsp;</div>

Similarly, with actual values without opacity, will give the below.

<div style=" background: rgb(243, 191, 189) ; ">&nbsp;</div>
<div style=" background: rgb(246, 143, 142) ; ">&nbsp;</div>
<div style=" background: rgb(249, 95 , 94)  ; ">&nbsp;</div>
<div style=" background: rgb(252, 47, 47)   ; ">&nbsp;</div>
<div style=" background: rgb(255, 0, 0)     ; ">&nbsp;</div>

You can have a look at this WORKING EXAMPLE.

Now, if we specifically target your issue, here is the WORKING DEMO SPECIFIC TO YOUR ISSUE.

The HTML

<div class="social">
    <img src="http://www.google.co.in/images/srpr/logo4w.png" border="0" />
</div>

The CSS:

social img{
    opacity:0.5;
}
.social img:hover {
    opacity:1;
    background-color:black;
    cursor:pointer;
    background: rgb(255, 0, 0) ; opacity: 0.5;
}

Hope this helps Now.

How to get an element by its href in jquery?

Yes, you can use jQuery's attribute selector for that.

var linksToGoogle = $('a[href="http://google.com"]');

Alternatively, if your interest is rather links starting with a certain URL, use the attribute-starts-with selector:

var allLinksToGoogle = $('a[href^="http://google.com"]');

What is going wrong when Visual Studio tells me "xcopy exited with code 4"

In my case the issue was due to incorrect build order. One project had an xcopy command on post-build events to copy files from bin folder to another folder. But because of incorrect dependencies new files were getting created in bin folder while xcopy is in progress.

In VS right click on the project where you have post-build events. Go to Build Dependencies > Project Dependencies and make sure its correct. Verify the project build order(next tab to dependencies) as well.

Global constants file in Swift

I am abit late to the party.

No matter here's how i manage the constants file so that it makes more sense to developers while writing code in swift.

FOR URL:

//URLConstants.swift

  struct APPURL {

    private struct Domains {
        static let Dev = "http://test-dev.cloudapp.net"
        static let UAT = "http://test-UAT.com"
        static let Local = "192.145.1.1"
        static let QA = "testAddress.qa.com"
    }

    private  struct Routes {
        static let Api = "/api/mobile"
    }

    private  static let Domain = Domains.Dev
    private  static let Route = Routes.Api
    private  static let BaseURL = Domain + Route

    static var FacebookLogin: String {
        return BaseURL  + "/auth/facebook"
    }
}

For CUSTOMFONTS:

//FontsConstants.swift
struct FontNames {

    static let LatoName = "Lato"
    struct Lato {
        static let LatoBold = "Lato-Bold"
        static let LatoMedium = "Lato-Medium"
        static let LatoRegular = "Lato-Regular"
        static let LatoExtraBold = "Lato-ExtraBold"
    }
}

FOR ALL THE KEYS USED IN APP

//KeyConstants.swift
    struct Key {

        static let DeviceType = "iOS"
        struct Beacon{
            static let ONEXUUID = "xxxx-xxxx-xxxx-xxxx"
        }

        struct UserDefaults {
            static let k_App_Running_FirstTime = "userRunningAppFirstTime"
        }

        struct Headers {
            static let Authorization = "Authorization"
            static let ContentType = "Content-Type"
        }
        struct Google{
            static let placesKey = "some key here"//for photos
            static let serverKey = "some key here"
        }

        struct ErrorMessage{
            static let listNotFound = "ERROR_LIST_NOT_FOUND"
            static let validationError = "ERROR_VALIDATION"
        }
    }

FOR COLOR CONSTANTS:

//ColorConstants.swift
struct AppColor {

    private struct Alphas {
        static let Opaque = CGFloat(1)
        static let SemiOpaque = CGFloat(0.8)
        static let SemiTransparent = CGFloat(0.5)
        static let Transparent = CGFloat(0.3)
    }

    static let appPrimaryColor =  UIColor.white.withAlphaComponent(Alphas.SemiOpaque)
    static let appSecondaryColor =  UIColor.blue.withAlphaComponent(Alphas.Opaque)

    struct TextColors {
        static let Error = AppColor.appSecondaryColor
        static let Success = UIColor(red: 0.1303, green: 0.9915, blue: 0.0233, alpha: Alphas.Opaque) 
    }

    struct TabBarColors{
        static let Selected = UIColor.white
        static let NotSelected = UIColor.black
    }

    struct OverlayColor {
        static let SemiTransparentBlack = UIColor.black.withAlphaComponent(Alphas.Transparent)
        static let SemiOpaque = UIColor.black.withAlphaComponent(Alphas.SemiOpaque)
        static let demoOverlay = UIColor.black.withAlphaComponent(0.6)
    }
}

You can wrap these all files in a common group named Constants in your Xcode Project.

And for more watch this video

Converting file size in bytes to human-readable string

Here is a prototype to convert a number to a readable string respecting the new international standards.

There are two ways to represent big numbers: You could either display them in multiples of 1000 = 10 3 (base 10) or 1024 = 2 10 (base 2). If you divide by 1000, you probably use the SI prefix names, if you divide by 1024, you probably use the IEC prefix names. The problem starts with dividing by 1024. Many applications use the SI prefix names for it and some use the IEC prefix names. The current situation is a mess. If you see SI prefix names you do not know whether the number is divided by 1000 or 1024

https://wiki.ubuntu.com/UnitsPolicy

http://en.wikipedia.org/wiki/Template:Quantities_of_bytes

Object.defineProperty(Number.prototype,'fileSize',{value:function(a,b,c,d){
 return (a=a?[1e3,'k','B']:[1024,'K','iB'],b=Math,c=b.log,
 d=c(this)/c(a[0])|0,this/b.pow(a[0],d)).toFixed(2)
 +' '+(d?(a[1]+'MGTPEZY')[--d]+a[2]:'Bytes');
},writable:false,enumerable:false});

This function contains no loop, and so it's probably faster than some other functions.

Usage:

IEC prefix

console.log((186457865).fileSize()); // default IEC (power 1024)
//177.82 MiB
//KiB,MiB,GiB,TiB,PiB,EiB,ZiB,YiB

SI prefix

console.log((186457865).fileSize(1)); //1,true for SI (power 1000)
//186.46 MB 
//kB,MB,GB,TB,PB,EB,ZB,YB

i set the IEC as default because i always used binary mode to calculate the size of a file... using the power of 1024


If you just want one of them in a short oneliner function:

SI

function fileSizeSI(a,b,c,d,e){
 return (b=Math,c=b.log,d=1e3,e=c(a)/c(d)|0,a/b.pow(d,e)).toFixed(2)
 +' '+(e?'kMGTPEZY'[--e]+'B':'Bytes')
}
//kB,MB,GB,TB,PB,EB,ZB,YB

IEC

function fileSizeIEC(a,b,c,d,e){
 return (b=Math,c=b.log,d=1024,e=c(a)/c(d)|0,a/b.pow(d,e)).toFixed(2)
 +' '+(e?'KMGTPEZY'[--e]+'iB':'Bytes')
}
//KiB,MiB,GiB,TiB,PiB,EiB,ZiB,YiB

Usage:

console.log(fileSizeIEC(7412834521));

if you have some questions about the functions just ask

How do I fix PyDev "Undefined variable from import" errors?

in preferences --> PyDev --> PyLint under arguments to pass to PyLint add this line:

--generated-members=objects

you will need to do this for each generated . I found this by googling, but I lost the reference.

typeof !== "undefined" vs. != null

if (input == undefined) { ... }

works just fine. It is of course not a null comparison, but I usually find that if I need to distinguish between undefined and null, I actually rather need to distinguish between undefined and just any false value, so

else if (input) { ... }

does it.

If a program redefines undefined it is really braindead anyway.

The only reason I can think of was for IE4 compatibility, it did not understand the undefined keyword (which is not actually a keyword, unfortunately), but of course values could be undefined, so you had to have this:

var undefined;

and the comparison above would work just fine.

In your second example, you probably need double parentheses to make lint happy?

How to make a HTTP request using Ruby on Rails?

You can use Ruby's Net::HTTP class:

require 'net/http'

url = URI.parse('http://www.example.com/index.html')
req = Net::HTTP::Get.new(url.to_s)
res = Net::HTTP.start(url.host, url.port) {|http|
  http.request(req)
}
puts res.body

SQL for ordering by number - 1,2,3,4 etc instead of 1,10,11,12

ORDER_BY cast(registration_no as unsigned) ASC

gives the desired result with warnings.

Hence, better to go for

ORDER_BY registration_no + 0 ASC

for a clean result without any SQL warnings.

Inheriting constructors

You have to explicitly define the constructor in B and explicitly call the constructor for the parent.

B(int x) : A(x) { }

or

B() : A(5) { }

Query to get the names of all tables in SQL Server 2008 Database

Try this:

SELECT s.NAME + '.' + t.NAME AS TableName
FROM sys.tables t
INNER JOIN sys.schemas s
    ON t.schema_id = s.schema_id

it will display the schema+table name for all tables in the current database.

Here is a version that will list every table in every database on the current server. it allows a search parameter to be used on any part or parts of the server+database+schema+table names:

SET NOCOUNT ON
DECLARE @AllTables table (CompleteTableName nvarchar(4000))
DECLARE @Search nvarchar(4000)
       ,@SQL   nvarchar(4000)
SET @Search=null --all rows
SET @SQL='select @@SERVERNAME+''.''+''?''+''.''+s.name+''.''+t.name from [?].sys.tables t inner join sys.schemas s on t.schema_id=s.schema_id WHERE @@SERVERNAME+''.''+''?''+''.''+s.name+''.''+t.name LIKE ''%'+ISNULL(@SEARCH,'')+'%'''

INSERT INTO @AllTables (CompleteTableName)
    EXEC sp_msforeachdb @SQL
SET NOCOUNT OFF
SELECT * FROM @AllTables ORDER BY 1

set @Search to NULL for all tables, set it to things like 'dbo.users' or 'users' or '.master.dbo' or even include wildcards like '.master.%.u', etc.

How do you create a custom AuthorizeAttribute in ASP.NET Core?

I'm the asp.net security person. Firstly let me apologize that none of this is documented yet outside of the music store sample or unit tests, and it's all still being refined in terms of exposed APIs. Detailed documentation is here.

We don't want you writing custom authorize attributes. If you need to do that we've done something wrong. Instead, you should be writing authorization requirements.

Authorization acts upon Identities. Identities are created by authentication.

You say in comments you want to check a session ID in a header. Your session ID would be the basis for identity. If you wanted to use the Authorize attribute you'd write an authentication middleware to take that header and turn it into an authenticated ClaimsPrincipal. You would then check that inside an authorization requirement. Authorization requirements can be as complicated as you like, for example here's one that takes a date of birth claim on the current identity and will authorize if the user is over 18;

public class Over18Requirement : AuthorizationHandler<Over18Requirement>, IAuthorizationRequirement
{
        public override void Handle(AuthorizationHandlerContext context, Over18Requirement requirement)
        {
            if (!context.User.HasClaim(c => c.Type == ClaimTypes.DateOfBirth))
            {
                context.Fail();
                return;
            }

            var dateOfBirth = Convert.ToDateTime(context.User.FindFirst(c => c.Type == ClaimTypes.DateOfBirth).Value);
            int age = DateTime.Today.Year - dateOfBirth.Year;
            if (dateOfBirth > DateTime.Today.AddYears(-age))
            {
                age--;
            }

            if (age >= 18)
            {
                context.Succeed(requirement);
            }
            else
            {
                context.Fail();
            }
        }
    }
}

Then in your ConfigureServices() function you'd wire it up

services.AddAuthorization(options =>
{
    options.AddPolicy("Over18", 
        policy => policy.Requirements.Add(new Authorization.Over18Requirement()));
});

And finally, apply it to a controller or action method with

[Authorize(Policy = "Over18")]

SQL Server copy all rows from one table into another i.e duplicate table

Either you can use RAW SQL:

INSERT INTO DEST_TABLE (Field1, Field2) 
SELECT Source_Field1, Source_Field2 
FROM SOURCE_TABLE

Or use the wizard:

  1. Right Click on the Database -> Tasks -> Export Data
  2. Select the source/target Database
  3. Select source/target table and fields
  4. Copy the data

Then execute:

TRUNCATE TABLE SOURCE_TABLE

Select datatype of the field in postgres

Try this request :

SELECT column_name, data_type FROM information_schema.columns WHERE 
table_name = 'YOUR_TABLE' AND column_name = 'YOUR_FIELD';

How to send emails from my Android application?

/**
 * Will start the chosen Email app
 *
 * @param context    current component context.
 * @param emails     Emails you would like to send to.
 * @param subject    The subject that will be used in the Email app.
 * @param forceGmail True - if you want to open Gmail app, False otherwise. If the Gmail
 *                   app is not installed on this device a chooser will be shown.
 */
public static void sendEmail(Context context, String[] emails, String subject, boolean forceGmail) {

    Intent i = new Intent(Intent.ACTION_SENDTO);
    i.setData(Uri.parse("mailto:"));
    i.putExtra(Intent.EXTRA_EMAIL, emails);
    i.putExtra(Intent.EXTRA_SUBJECT, subject);
    if (forceGmail && isPackageInstalled(context, "com.google.android.gm")) {
        i.setPackage("com.google.android.gm");
        i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(i);
    } else {
        try {
            context.startActivity(Intent.createChooser(i, "Send mail..."));
        } catch (ActivityNotFoundException e) {
            Toast.makeText(context, "No email app is installed on your device...", Toast.LENGTH_SHORT).show();
        }
    }
}

/**
 * Check if the given app is installed on this devuice.
 *
 * @param context     current component context.
 * @param packageName The package name you would like to check.
 * @return True if this package exist, otherwise False.
 */
public static boolean isPackageInstalled(@NonNull Context context, @NonNull String packageName) {
    PackageManager pm = context.getPackageManager();
    if (pm != null) {
        try {
            pm.getPackageInfo(packageName, 0);
            return true;
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
    }
    return false;
}

Clearing NSUserDefaults

I found this:

osascript -e 'tell application "iOS Simulator" to quit'
xcrun simctl list devices | grep -v '^[-=]' | cut -d "(" -f2 | cut -d ")" -f1 | xargs -I {} xcrun simctl erase "{}"

Source: https://gist.github.com/ZevEisenberg/5a172662cb576872d1ab

How to remove unused C/C++ symbols with GCC and ld?

You can use strip binary on object file(eg. executable) to strip all symbols from it.

Note: it changes file itself and don't create copy.

Autowiring two beans implementing same interface - how to set default bean to autowire?

For Spring 2.5, there's no @Primary. The only way is to use @Qualifier.

How to Convert JSON object to Custom C# object?

public static class Utilities
{
    public static T Deserialize<T>(string jsonString)
    {
        using (MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(jsonString)))
        {    
            DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(T));
            return (T)serializer.ReadObject(ms);
        }
    }
}

More information go to following link http://ishareidea.blogspot.in/2012/05/json-conversion.html

About DataContractJsonSerializer Class you can read here.

Make sure that the controller has a parameterless public constructor error

In my case, Unity turned out to be a red herring. My problem was a result of different projects targeting different versions of .NET. Unity was set up right and everything was registered with the container correctly. Everything compiled fine. But the type was in a class library, and the class library was set to target .NET Framework 4.0. The WebApi project using Unity was set to target .NET Framework 4.5. Changing the class library to also target 4.5 fixed the problem for me.

I discovered this by commenting out the DI constructor and adding default constructor. I commented out the controller methods and had them throw NotImplementedException. I confirmed that I could reach the controller, and seeing my NotImplementedException told me it was instantiating the controller fine. Next, in the default constructor, I manually instantiated the dependency chain instead of relying on Unity. It still compiled, but when I ran it the error message came back. This confirmed for me that I still got the error even when Unity was out of the picture. Finally, I started at the bottom of the chain and worked my way up, commenting out one line at a time and retesting until I no longer got the error message. This pointed me in the direction of the offending class, and from there I figured out that it was isolated to a single assembly.

Cannot connect to the Docker daemon at unix:/var/run/docker.sock. Is the docker daemon running?

here's the solution which works for me on Linux

systemctl start docker.

TypeError: a bytes-like object is required, not 'str' in python and CSV

You are opening the csv file in binary mode, it should be 'w'

import csv

# open csv file in write mode with utf-8 encoding
with open('output.csv','w',encoding='utf-8',newline='')as w:
    fieldnames = ["SNo", "States", "Dist", "Population"]
    writer = csv.DictWriter(w, fieldnames=fieldnames)
    # write list of dicts
    writer.writerows(list_of_dicts) #writerow(dict) if write one row at time

SVN how to resolve new tree conflicts when file is added on two branches

What if the incoming changes are the ones you want? I'm unable to run svn resolve --accept theirs-full

svn resolve --accept base

Set selected radio from radio group with a value

There is a better way of checking radios and checkbox; you have to pass an array of values to the val method instead of a raw value

Note: If you simply pass the value by itself (without being inside an array), that will result in all values of "mygroup" being set to the value.

$("input[name=mygroup]").val([5]);

Here is the jQuery doc that explains how it works: http://api.jquery.com/val/#val-value

And .val([...]) also works with form elements like <input type="checkbox">, <input type="radio">, and <option>s inside of a <select>.

The inputs and the options having a value that matches one of the elements of the array will be checked or selected, while those having a value that don't match one of the elements of the array will be unchecked or unselected

Fiddle demonstrating this working: https://jsfiddle.net/92nekvp3/

Select records from today, this week, this month php mysql

You can do same thing using single query

SELECT sum(if(DATE(dDate)=DATE(CURRENT_TIMESTAMP),earning,null)) astodays,
       sum(if(YEARWEEK(dDate)=YEARWEEK(CURRENT_DATE),earning,null)) as weeks, 
       IF((MONTH(dDate) = MONTH(CURRENT_TIMESTAMP()) AND YEAR(dDate) = YEAR(CURRENT_TIMESTAMP())),sum(earning),0) AS months,
       IF(YEAR(dDate) = YEAR(CURRENT_TIMESTAMP()),sum(earning),0) AS years, 
       sum(fAdminFinalEarning) as total_earning FROM `earning`

Hope this works.

JSON.parse unexpected token s

Variables (something) are not valid JSON, verify using http://jsonlint.com/

How to npm install to a specified directory?

As of npm version 3.8.6, you can use

npm install --prefix ./install/here <package>

to install in the specified directory. NPM automatically creates node_modules folder even when a node_modules directory already exists in the higher up hierarchy. You can also have a package.json in the current directory and then install it in the specified directory using --prefix option:

npm install --prefix ./install/here

As of npm 6.0.0, you can use

npm install --prefix ./install/here ./

to install the package.json in current directory to "./install/here" directory. There is one thing that I have noticed on Mac that it creates a symlink to parent folder inside the node_modules directory. But, it still works.

NOTE: NPM honours the path that you've specified through the --prefix option. It resolves as per npm documentation on folders, only when npm install is used without the --prefix option.

How to programmatically set the ForeColor of a label to its default?

For example summer :

lblSummer.foreColor = color.Yellow;

Best /Fastest way to read an Excel Sheet into a DataTable?

public DataTable ImportExceltoDatatable(string filepath)
{
    // string sqlquery= "Select * From [SheetName$] Where YourCondition";
    string sqlquery = "Select * From [SheetName$] Where Id='ID_007'";
    DataSet ds = new DataSet();
    string constring = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + filepath + ";Extended Properties=\"Excel 12.0;HDR=YES;\"";
    OleDbConnection con = new OleDbConnection(constring + "");
    OleDbDataAdapter da = new OleDbDataAdapter(sqlquery, con);
    da.Fill(ds);
    DataTable dt = ds.Tables[0];
    return dt;
}

How to stop "setInterval"

setInterval returns an id that you can use to cancel the interval with clearInterval()

How to run python script on terminal (ubuntu)?

Sorry, Im a newbie myself and I had this issue:

./hello.py: line 1: syntax error near unexpected token "Hello World"' ./hello.py: line 1:print("Hello World")'

I added the file header for the python 'deal' as #!/usr/bin/python

Then simple executed the program with './hello.py'

Unable to run Java GUI programs with Ubuntu

I stopped getting this exception when I installed default-jdk using apt. I'm running Ubuntu 14.04 (Trusty Tahr), and the problem appears to have been the result of having a "headless" Java installed. All I did was:

sudo apt-get install default-jdk

How to add extension methods to Enums

You can create an extension for anything, even object(although that's not considered best-practice). Understand an extension method just as a public static method. You can use whatever parameter-type you like on methods.

public static class DurationExtensions
{
  public static int CalculateDistanceBetween(this Duration first, Duration last)
  {
    //Do something here
  }
}

In Excel how to get the left 5 characters of each cell in a specified column and put them into a new column

1) Put =Left(E1,5) in F1

2) Copy F1, then select entire F column and paste.

How to get the size of the current screen in WPF?

Here budy. This will give you only the width and height of the workarea

System.Windows.SystemParameters.WorkArea.Width
System.Windows.SystemParameters.WorkArea.Height

Make columns of equal width in <table>

Use following property same as table and its fully dynamic:

_x000D_
_x000D_
ul {_x000D_
    width: 100%;_x000D_
    display: table;_x000D_
    table-layout: fixed; /* optional, for equal spacing */_x000D_
    border-collapse: collapse;_x000D_
}_x000D_
li {_x000D_
    display: table-cell;_x000D_
    text-align: center;_x000D_
    border: 1px solid pink;_x000D_
    vertical-align: middle;_x000D_
}
_x000D_
<ul>_x000D_
  <li>foo<br>foo</li>_x000D_
  <li>barbarbarbarbar</li>_x000D_
  <li>baz klxjgkldjklg </li>_x000D_
  <li>baz</li>_x000D_
  <li>baz lds.jklklds</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

May be its solve your issue.

VBA code to set date format for a specific column as "yyyy-mm-dd"

It works, when you use both lines:

Application.ActiveWorkbook.Worksheets("data").Range("C1", "C20000") = Format(Date, "yyyy-mm-dd")
Application.ActiveWorkbook.Worksheets("data").Range("C1", "C20000").NumberFormat = "yyyy-mm-dd"

How to turn off word wrapping in HTML?

This worked for me to stop silly work breaks from happening within Chrome textareas

word-break: keep-all;

Easiest way to change font and font size

This should do it (bold as well);

label1.Font = new Font("Serif", 24,FontStyle.Bold);

MySQL INNER JOIN select only one row from second table

   SELECT u.* 
        FROM users AS u
        INNER JOIN (
            SELECT p.*,
             @num := if(@id = user_id, @num + 1, 1) as row_number,
             @id := user_id as tmp
            FROM payments AS p,
                 (SELECT @num := 0) x,
                 (SELECT @id := 0) y
            ORDER BY p.user_id ASC, date DESC)
        ON (p.user_id = u.id) and (p.row_number=1)
        WHERE u.package = 1

Pass user defined environment variable to tomcat

You can use setenv.bat or .sh to pass the environment variables to the Tomcat.

Create CATALINA_BASE/bin/setenv.bat or .sh file and put the following line in it, and then start the Tomcat.

On Windows:

set APP_MASTER_PASSWORD=foo

On Unix like systems:

export APP_MASTER_PASSWORD=foo

Find which version of package is installed with pip

You can use the grep command to find out.

pip show <package_name>|grep Version

Example:

pip show urllib3|grep Version

will show only the versions.

Metadata-Version: 2.0
Version: 1.12

String to date in Oracle with milliseconds

I don't think you can use fractional seconds with to_date or the DATE type in Oracle. I think you need to_timestamp which returns a TIMESTAMP type.

Why can't I define a static method in a Java interface?

Interfaces just provide a list of things a class will provide, not an actual implementation of those things, which is what your static item is.

If you want statics, use an abstract class and inherit it, otherwise, remove the static.

Hope that helps!

Execute Stored Procedure from a Function

Another option, in addition to using OPENQUERY and xp_cmdshell, is to use SQLCLR (SQL Server's "CLR Integration" feature). Not only is the SQLCLR option more secure than those other two methods, but there is also the potential benefit of being able to call the stored procedure in the current session such that it would have access to any session-based objects or settings, such as:

  • temporary tables
  • temporary stored procedures
  • CONTEXT_INFO

This can be achieved by using "context connection = true;" as the ConnectionString. Just keep in mind that all other restrictions placed on T-SQL User-Defined Functions will be enforced (i.e. cannot have any side-effects).

If you use a regular connection (i.e. not using the context connection), then it will operate as an independent call, just like it does when using the OPENQUERY and xp_cmdshell methods.

HOWEVER, please keep in mind that if you will be using a function that calls a stored procedure (regardless of which of the 3 noted methods you use) in a statement that affects more than 1 row, then the behavior cannot be expected to run once per row. As @MartinSmith mentioned in a comment on @MatBailie's answer, the Query Optimizer does not guarantee either the timing or number of executions of functions. But if you are using it in a SET @Variable = function(); statement or SELECT * FROM function(); query, then it should be ok.

An example of using a .NET / C# SQLCLR user-defined function to execute a stored procedure is shown in the following article (which I wrote):

Stairway to SQLCLR Level 2: Sample Stored Procedure and Function

private constructor

For example, you can invoke a private constructor inside a friend class or a friend function.

Singleton pattern usually uses it to make sure that nobody creates more instances of the intended type.

CSS3's border-radius property and border-collapse:collapse don't mix. How can I use border-radius to create a collapsed table with rounded corners?

I tried a workaround using the pseudo elements :before and :after on the thead th:first-child and thead th:last-child

In combination with wrapping the table with a <div class="radius borderCCC">

table thead th:first-child:before{ 
    content:" ";
    position:absolute;
    top:-1px;
    left:-1px;
    width:15px;
    height:15px;
    border-left:1px solid #ccc;
    border-top:1px solid #ccc; 
    -webkit-border-radius:5px 0px 0px;
}
table thead th:last-child:after{ 
    content:" "; 
    position:absolute; 
    top:-1px;
    right:-1px; 
    width:15px;
    height:15px;
    border-right:1px solid #ccc;
    border-top:1px solid #ccc;
    -webkit-border-radius:0px 5px 0px 0px;
}

see jsFiddle

Works for me in chrome (13.0.782.215) Let me know if this works for you in other browsers.

AngularJS/javascript converting a date String to date object

I know this is in the above answers, but my point is that I think all you need is

new Date(collectionDate);

if your goal is to convert a date string into a date (as per the OP "How do I convert it to a date object?").

Why are hexadecimal numbers prefixed with 0x?

Note: I don't know the correct answer, but the below is just my personal speculation!

As has been mentioned a 0 before a number means it's octal:

04524 // octal, leading 0

Imagine needing to come up with a system to denote hexadecimal numbers, and note we're working in a C style environment. How about ending with h like assembly? Unfortunately you can't - it would allow you to make tokens which are valid identifiers (eg. you could name a variable the same thing) which would make for some nasty ambiguities.

8000h // hex
FF00h // oops - valid identifier!  Hex or a variable or type named FF00h?

You can't lead with a character for the same reason:

xFF00 // also valid identifier

Using a hash was probably thrown out because it conflicts with the preprocessor:

#define ...
#FF00 // invalid preprocessor token?

In the end, for whatever reason, they decided to put an x after a leading 0 to denote hexadecimal. It is unambiguous since it still starts with a number character so can't be a valid identifier, and is probably based off the octal convention of a leading 0.

0xFF00 // definitely not an identifier!

Align DIV to bottom of the page

Try position:fixed; bottom:0;. This will make your div to stay fixed at the bottom.

WORKING DEMO

The HTML:

<div id="bottom-stuff">
  <div id="search"> MY DIV </div>
</div>
<div id="bottom"> MY DIV </div>

The CSS:

#bottom-stuff {

    position: relative;
}

#bottom{

    position: fixed; 
    background:gray; 
    width:100%;
    bottom:0;
}

#search{height:5000px; overflow-y:scroll;}

Hope this helps.

How do I clear only a few specific objects from the workspace?

If you're using RStudio, please consider never using the rm(list = ls()) approach!* Instead, you should build your workflow around frequently employing the Ctrl+Shift+F10 shortcut to restart your R session. This is the fastest way to both nuke the current set of user-defined variables AND to clear loaded packages, devices, etc. The reproducibility of your work will increase markedly by adopting this habit.

See this excellent thread on Rstudio community for (h/t @kierisi) for a more thorough discussion (the main gist is captured by what I've stated already).

I must admit my own first few years of R coding featured script after script starting with the rm "trick" -- I'm writing this answer as advice to anyone else who may be starting out their R careers.

*of course there are legitimate uses for this -- much like attach -- but beginning users will be much better served (IMO) crossing that bridge at a later date.

How can I print message in Makefile?

$(info your_text) : Information. This doesn't stop the execution.

$(warning your_text) : Warning. This shows the text as a warning.

$(error your_text) : Fatal Error. This will stop the execution.

Getting the name of the currently executing method

This is an expansion on virgo47's answer (above).

It provides some static methods to get the current and invoking class / method names.

/* Utility class: Getting the name of the current executing method 
 * https://stackoverflow.com/questions/442747/getting-the-name-of-the-current-executing-method
 * 
 * Provides: 
 * 
 *      getCurrentClassName()
 *      getCurrentMethodName()
 *      getCurrentFileName()
 * 
 *      getInvokingClassName()
 *      getInvokingMethodName()
 *      getInvokingFileName()
 *
 * Nb. Using StackTrace's to get this info is expensive. There are more optimised ways to obtain
 * method names. See other stackoverflow posts eg. https://stackoverflow.com/questions/421280/in-java-how-do-i-find-the-caller-of-a-method-using-stacktrace-or-reflection/2924426#2924426
 *
 * 29/09/2012 (lem) - added methods to return (1) fully qualified names and (2) invoking class/method names
 */
package com.stackoverflow.util;

public class StackTraceInfo
{
    /* (Lifted from virgo47's stackoverflow answer) */
    private static final int CLIENT_CODE_STACK_INDEX;

    static {
        // Finds out the index of "this code" in the returned stack trace - funny but it differs in JDK 1.5 and 1.6
        int i = 0;
        for (StackTraceElement ste: Thread.currentThread().getStackTrace())
        {
            i++;
            if (ste.getClassName().equals(StackTraceInfo.class.getName()))
            {
                break;
            }
        }
        CLIENT_CODE_STACK_INDEX = i;
    }

    public static String getCurrentMethodName()
    {
        return getCurrentMethodName(1);     // making additional overloaded method call requires +1 offset
    }

    private static String getCurrentMethodName(int offset)
    {
        return Thread.currentThread().getStackTrace()[CLIENT_CODE_STACK_INDEX + offset].getMethodName();
    }

    public static String getCurrentClassName()
    {
        return getCurrentClassName(1);      // making additional overloaded method call requires +1 offset
    }

    private static String getCurrentClassName(int offset)
    {
    return Thread.currentThread().getStackTrace()[CLIENT_CODE_STACK_INDEX + offset].getClassName();
    }

    public static String getCurrentFileName()
    {
        return getCurrentFileName(1);     // making additional overloaded method call requires +1 offset
    }

    private static String getCurrentFileName(int offset)
    {
        String filename = Thread.currentThread().getStackTrace()[CLIENT_CODE_STACK_INDEX + offset].getFileName();
        int lineNumber = Thread.currentThread().getStackTrace()[CLIENT_CODE_STACK_INDEX + offset].getLineNumber();

        return filename + ":" + lineNumber;
    }

    public static String getInvokingMethodName()
    {
        return getInvokingMethodName(2); 
    }

    private static String getInvokingMethodName(int offset)
    {
        return getCurrentMethodName(offset + 1);    // re-uses getCurrentMethodName() with desired index
    }

    public static String getInvokingClassName()
    {
        return getInvokingClassName(2); 
    }

    private static String getInvokingClassName(int offset)
    {
        return getCurrentClassName(offset + 1);     // re-uses getCurrentClassName() with desired index
    }

    public static String getInvokingFileName()
    {
        return getInvokingFileName(2); 
    }

    private static String getInvokingFileName(int offset)
    {
        return getCurrentFileName(offset + 1);     // re-uses getCurrentFileName() with desired index
    }

    public static String getCurrentMethodNameFqn()
    {
        return getCurrentMethodNameFqn(1);
    }

    private static String getCurrentMethodNameFqn(int offset)
    {
        String currentClassName = getCurrentClassName(offset + 1);
        String currentMethodName = getCurrentMethodName(offset + 1);

        return currentClassName + "." + currentMethodName ;
    }

    public static String getCurrentFileNameFqn()
    {
        String CurrentMethodNameFqn = getCurrentMethodNameFqn(1);
        String currentFileName = getCurrentFileName(1);

        return CurrentMethodNameFqn + "(" + currentFileName + ")";
    }

    public static String getInvokingMethodNameFqn()
    {
        return getInvokingMethodNameFqn(2);
    }

    private static String getInvokingMethodNameFqn(int offset)
    {
        String invokingClassName = getInvokingClassName(offset + 1);
        String invokingMethodName = getInvokingMethodName(offset + 1);

        return invokingClassName + "." + invokingMethodName;
    }

    public static String getInvokingFileNameFqn()
    {
        String invokingMethodNameFqn = getInvokingMethodNameFqn(2);
        String invokingFileName = getInvokingFileName(2);

        return invokingMethodNameFqn + "(" + invokingFileName + ")";
    }
}

How do I render a shadow?

  panel: {
    // ios
    backgroundColor: '#03A9F4',
    alignItems: 'center', 
    shadowOffset: {width: 0, height: 13}, 
    shadowOpacity: 0.3,
    shadowRadius: 6,

    // android (Android +5.0)
    elevation: 3,
  }

or you can use react-native-shadow for android

Maven command to determine which settings.xml file Maven is using

Quick and dirty method to determine if Maven is using desired settings.xml would be invalidate its xml and run some safe maven command that requires settings.xml.

If it reads this settings.xml then Maven reports an error: "Error reading settings.xml..."

How to wait till the response comes from the $http request, in angularjs?

I was having the same problem and none if these worked for me. Here is what did work though...

app.factory('myService', function($http) {
    var data = function (value) {
            return $http.get(value);
    }

    return { data: data }
});

and then the function that uses it is...

vm.search = function(value) {

        var recieved_data = myService.data(value);

        recieved_data.then(
            function(fulfillment){
                vm.tags = fulfillment.data;
            }, function(){
                console.log("Server did not send tag data.");
        });
    };

The service isn't that necessary but I think its a good practise for extensibility. Most of what you will need for one will for any other, especially when using APIs. Anyway I hope this was helpful.

Printing all global variables/local variables?

In addition, since info locals does not display the arguments to the function you're in, use

(gdb) info args

For example:

int main(int argc, char *argv[]) {
    argc = 6*7;    //Break here.
    return 0;
}

argc and argv won't be shown by info locals. The message will be "No locals."

Reference: info locals command.

"unadd" a file to svn before commit

Full process (Unix svn package):

Check files are not in SVN:

> svn st -u folder 
? folder

Add all (including ignored files):

> svn add folder
A   folder
A   folder/file1.txt
A   folder/folder2
A   folder/folder2/file2.txt
A   folder/folderToIgnore
A   folder/folderToIgnore/fileToIgnore1.txt
A   fileToIgnore2.txt

Remove "Add" Flag to All * Ignore * files:

> cd folder

> svn revert --recursive folderToIgnore
Reverted 'folderToIgnore'
Reverted 'folderToIgnore/fileToIgnore1.txt'


> svn revert fileToIgnore2.txt
Reverted 'fileToIgnore2.txt'

Edit svn ignore on folder

svn propedit svn:ignore .

Add two singles lines with just the following:

folderToIgnore
fileToIgnore2.txt

Check which files will be upload and commit:

> cd ..

> svn st -u
A   folder
A   folder/file1.txt
A   folder/folder2
A   folder/folder2/file2.txt


> svn ci -m "Commit message here"

.htaccess: Invalid command 'RewriteEngine', perhaps misspelled or defined by a module not included in the server configuration

or defined by a module not included in the server configuration

Check to make sure you have mod_rewrite enabled.

From: https://webdevdoor.com/php/mod_rewrite-windows-apache-url-rewriting

  1. Find the httpd.conf file (usually you will find it in a folder called conf, config or something along those lines)
  2. Inside the httpd.conf file uncomment the line LoadModule rewrite_module modules/mod_rewrite.so (remove the pound '#' sign from in front of the line)
  3. Also find the line ClearModuleList is uncommented then find and make sure that the line AddModule mod_rewrite.c is not commented out.

If the LoadModule rewrite_module modules/mod_rewrite.so line is missing from the httpd.conf file entirely, just add it.

Sample command

To enable the module in a standard ubuntu do this:

a2enmod rewrite
systemctl restart apache2

Anaconda / Python: Change Anaconda Prompt User Path

In both: Anaconda prompt and the old cmd.exe, you change your directory by first changing to the drive you want, by simply writing its name followed by a ':', exe: F: , which will take you to the drive named 'F' on your machine. Then using the command cd to navigate your way inside that drive as you normally would.

How to SHA1 hash a string in Android?

You don't need andorid for this. You can just do it in simple java.

Have you tried a simple java example and see if this returns the right sha1.

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class AeSimpleSHA1 {
    private static String convertToHex(byte[] data) {
        StringBuilder buf = new StringBuilder();
        for (byte b : data) {
            int halfbyte = (b >>> 4) & 0x0F;
            int two_halfs = 0;
            do {
                buf.append((0 <= halfbyte) && (halfbyte <= 9) ? (char) ('0' + halfbyte) : (char) ('a' + (halfbyte - 10)));
                halfbyte = b & 0x0F;
            } while (two_halfs++ < 1);
        }
        return buf.toString();
    }

    public static String SHA1(String text) throws NoSuchAlgorithmException, UnsupportedEncodingException {
        MessageDigest md = MessageDigest.getInstance("SHA-1");
        byte[] textBytes = text.getBytes("iso-8859-1");
        md.update(textBytes, 0, textBytes.length);
        byte[] sha1hash = md.digest();
        return convertToHex(sha1hash);
    }
}

Also share what your expected sha1 should be. Maybe ObjectC is doing it wrong.

Concatenate columns in Apache Spark DataFrame

In Java you can do this to concatenate multiple columns. The sample code is to provide you a scenario and how to use it for better understanding.

SparkSession spark = JavaSparkSessionSingleton.getInstance(rdd.context().getConf());
Dataset<Row> reducedInventory = spark.sql("select * from table_name")
                        .withColumn("concatenatedCol",
                                concat(col("col1"), lit("_"), col("col2"), lit("_"), col("col3")));


class JavaSparkSessionSingleton {
    private static transient SparkSession instance = null;

    public static SparkSession getInstance(SparkConf sparkConf) {
        if (instance == null) {
            instance = SparkSession.builder().config(sparkConf)
                    .getOrCreate();
        }
        return instance;
    }
}

The above code concatenated col1,col2,col3 seperated by "_" to create a column with name "concatenatedCol".

How do I resize an image using PIL and maintain its aspect ratio?

I will also add a version of the resize that keeps the aspect ratio fixed. In this case, it will adjust the height to match the width of the new image, based on the initial aspect ratio, asp_rat, which is float (!). But, to adjust the width to the height, instead, you just need to comment one line and uncomment the other in the else loop. You will see, where.

You do not need the semicolons (;), I keep them just to remind myself of syntax of languages I use more often.

from PIL import Image

img_path = "filename.png";
img = Image.open(img_path);     # puts our image to the buffer of the PIL.Image object

width, height = img.size;
asp_rat = width/height;

# Enter new width (in pixels)
new_width = 50;

# Enter new height (in pixels)
new_height = 54;

new_rat = new_width/new_height;

if (new_rat == asp_rat):
    img = img.resize((new_width, new_height), Image.ANTIALIAS); 

# adjusts the height to match the width
# NOTE: if you want to adjust the width to the height, instead -> 
# uncomment the second line (new_width) and comment the first one (new_height)
else:
    new_height = round(new_width / asp_rat);
    #new_width = round(new_height * asp_rat);
    img = img.resize((new_width, new_height), Image.ANTIALIAS);

# usage: resize((x,y), resample)
# resample filter -> PIL.Image.BILINEAR, PIL.Image.NEAREST (default), PIL.Image.BICUBIC, etc..
# https://pillow.readthedocs.io/en/3.1.x/reference/Image.html#PIL.Image.Image.resize

# Enter the name under which you would like to save the new image
img.save("outputname.png");

And, it is done. I tried to document it as much as I can, so it is clear.

I hope it might be helpful to someone out there!

C# - Simplest way to remove first occurrence of a substring from another string

If you'd like a simple method to resolve this problem. (Can be used as an extension)

See below:

    public static string RemoveFirstInstanceOfString(this string value, string removeString)
    {
        int index = value.IndexOf(removeString, StringComparison.Ordinal);
        return index < 0 ? value : value.Remove(index, removeString.Length);
    }

Usage:

    string valueWithPipes = "| 1 | 2 | 3";
    string valueWithoutFirstpipe = valueWithPipes.RemoveFirstInstanceOfString("|");
    //Output, valueWithoutFirstpipe = " 1 | 2 | 3";

Inspired by and modified @LukeH's and @Mike's answer.

Don't forget the StringComparison.Ordinal to prevent issues with Culture settings. https://www.jetbrains.com/help/resharper/2018.2/StringIndexOfIsCultureSpecific.1.html

Clicking at coordinates without identifying element

This can be done using Actions class in java

Use following code -

new Actions(driver).moveByOffset(x coordinate, y coordinate).click().build().perform(); 

Note: Selenium 3 doesn't support Actions class for geckodriver

Also, note that x and y co-ordinates are relative values from current mouse position. Assuming mouse co-ordinates are at (0,0) to start with, if you want to use absolute values, you can perform the below action immediately after you clicked on it using the above code.

new Actions(driver).moveByOffset(-x coordinate, -y coordinate).perform();

Enable/Disable a dropdownbox in jquery

this is to disable dropdown2 , dropdown 3 if you select the option from dropdown1 that has the value 15

$("#dropdown1").change(function(){
            if ( $(this).val()!= "15" ) {
                $("#dropdown2").attr("disabled",true);
                $("#dropdown13").attr("disabled",true);

            }

take(1) vs first()

Operators first() and take(1) aren't the same.

The first() operator takes an optional predicate function and emits an error notification when no value matched when the source completed.

For example this will emit an error:

import { EMPTY, range } from 'rxjs';
import { first, take } from 'rxjs/operators';

EMPTY.pipe(
  first(),
).subscribe(console.log, err => console.log('Error', err));

... as well as this:

range(1, 5).pipe(
  first(val => val > 6),
).subscribe(console.log, err => console.log('Error', err));

While this will match the first value emitted:

range(1, 5).pipe(
  first(),
).subscribe(console.log, err => console.log('Error', err));

On the other hand take(1) just takes the first value and completes. No further logic is involved.

range(1, 5).pipe(
  take(1),
).subscribe(console.log, err => console.log('Error', err));

Then with empty source Observable it won't emit any error:

EMPTY.pipe(
  take(1),
).subscribe(console.log, err => console.log('Error', err));

Jan 2019: Updated for RxJS 6

Split a String into an array in Swift?

This has Changed again in Beta 5. Weee! It's now a method on CollectionType

Old:

var fullName = "First Last"
var fullNameArr = split(fullName) {$0 == " "}

New:

var fullName = "First Last"
var fullNameArr = fullName.split {$0 == " "}

Apples Release Notes

Rebuild all indexes in a Database

DECLARE @String NVARCHAR(MAX);
USE Databse Name;
SELECT @String
    =
(
    SELECT 'ALTER INDEX [' + dbindexes.[name] + '] ON [' + db.name + '].[' + dbschemas.[name] + '].[' + dbtables.[name]
           + '] REBUILD PARTITION = ALL WITH (DATA_COMPRESSION = PAGE);' + CHAR(10) AS [text()]
    FROM sys.dm_db_index_physical_stats(DB_ID(), NULL, NULL, NULL, NULL) AS indexstats
        INNER JOIN sys.tables dbtables
            ON dbtables.[object_id] = indexstats.[object_id]
        INNER JOIN sys.schemas dbschemas
            ON dbtables.[schema_id] = dbschemas.[schema_id]
        INNER JOIN sys.indexes AS dbindexes
            ON dbindexes.[object_id] = indexstats.[object_id]
               AND indexstats.index_id = dbindexes.index_id
        INNER JOIN sys.databases AS db
            ON db.database_id = indexstats.database_id
    WHERE dbindexes.name IS NOT NULL
          AND indexstats.database_id = DB_ID()
          AND indexstats.avg_fragmentation_in_percent >= 10
    ORDER BY indexstats.page_count DESC
    FOR XML PATH('')
);
EXEC (@String);

How to concatenate strings in a Windows batch file?

Note that the variables @fname or @ext can be simply concatenated. This:

forfiles /S /M *.pdf /C "CMD /C REN @path @fname_old.@ext"

renames all PDF files to "filename_old.pdf"

How do I concatenate strings?

Simple ways to concatenate strings in Rust

There are various methods available in Rust to concatenate strings

First method (Using concat!() ):

fn main() {
    println!("{}", concat!("a", "b"))
}

The output of the above code is :

ab


Second method (using push_str() and + operator):

fn main() {
    let mut _a = "a".to_string();
    let _b = "b".to_string();
    let _c = "c".to_string();

    _a.push_str(&_b);

    println!("{}", _a);

    println!("{}", _a + &_c);
}

The output of the above code is:

ab

abc


Third method (Using format!()):

fn main() {
    let mut _a = "a".to_string();
    let _b = "b".to_string();
    let _c = format!("{}{}", _a, _b);

    println!("{}", _c);
}

The output of the above code is :

ab

Check it out and experiment with Rust playground.

Show datalist labels but submit the actual value

Note that datalist is not the same as a select. It allows users to enter a custom value that is not in the list, and it would be impossible to fetch an alternate value for such input without defining it first.

Possible ways to handle user input are to submit the entered value as is, submit a blank value, or prevent submitting. This answer handles only the first two options.

If you want to disallow user input entirely, maybe select would be a better choice.


To show only the text value of the option in the dropdown, we use the inner text for it and leave out the value attribute. The actual value that we want to send along is stored in a custom data-value attribute:

To submit this data-value we have to use an <input type="hidden">. In this case we leave out the name="answer" on the regular input and move it to the hidden copy.

<input list="suggestionList" id="answerInput">
<datalist id="suggestionList">
    <option data-value="42">The answer</option>
</datalist>
<input type="hidden" name="answer" id="answerInput-hidden">

This way, when the text in the original input changes we can use javascript to check if the text also present in the datalist and fetch its data-value. That value is inserted into the hidden input and submitted.

document.querySelector('input[list]').addEventListener('input', function(e) {
    var input = e.target,
        list = input.getAttribute('list'),
        options = document.querySelectorAll('#' + list + ' option'),
        hiddenInput = document.getElementById(input.getAttribute('id') + '-hidden'),
        inputValue = input.value;

    hiddenInput.value = inputValue;

    for(var i = 0; i < options.length; i++) {
        var option = options[i];

        if(option.innerText === inputValue) {
            hiddenInput.value = option.getAttribute('data-value');
            break;
        }
    }
});

The id answer and answer-hidden on the regular and hidden input are needed for the script to know which input belongs to which hidden version. This way it's possible to have multiple inputs on the same page with one or more datalists providing suggestions.

Any user input is submitted as is. To submit an empty value when the user input is not present in the datalist, change hiddenInput.value = inputValue to hiddenInput.value = ""


Working jsFiddle examples: plain javascript and jQuery

Flutter does not find android sdk

Kindly first of all check your latest sdk first step: install latest Sdk platform

second step: Install all these licenses

Now Run

run flutter doctor --android-licenses Press Y against each agreement

run flutter doctor flutter doctor it will work fine.

C read file line by line

Use fgets() to read a line from a file handle.

Concatenate multiple node values in xpath

If you need to join xpath-selected text nodes but can not use string-join (when you are stuck with XSL 1.0) this might help:

<xsl:variable name="x">
    <xsl:apply-templates select="..." mode="string-join-mode"/>
</xsl:variable>
joined and normalized: <xsl:value-of select="normalize-space($x)"/>

<xsl:template match="*" mode="string-join-mode">
    <xsl:apply-templates mode="string-join-mode"/>
</xsl:template>    

<xsl:template match="text()" mode="string-join-mode">
    <xsl:value-of select="."/>
</xsl:template>    

Disabling the long-running-script message in Internet Explorer

I can't comment on the previous answers since I haven't tried them. However I know the following strategy works for me. It is a bit less elegant but gets the job done. It also doesn't require breaking code into chunks like some other approaches seem to do. In my case, that was not an option, because my code had recursive calls to the logic that was being looped; i.e., there was no practical way to just hop out of the loop, then be able to resume in some way by using global vars to preserve current state since those globals could be changed by references to them in a subsequent recursed call. So I needed a straight-forward way that would not offer a chance for the code to compromise the data state integrity.

Assuming the "stop script?" dialog is coming up during a for() loop executuion after a number of iterations (in my case, about 8-10), and messing with the registry is no option, here was the fix (for me, anyway):

var anarray = [];
var array_member = null;
var counter = 0; // Could also be initialized to the max desired value you want, if
                 // planning on counting downward.

function func_a()
{
 // some code
 // optionally, set 'counter' to some desired value.
 ...
 anarray = { populate array with objects to be processed that would have been
             processed by a for() }
 // 'anarry' is going to be reduced in size iteratively.  Therefore, if you need
 //  to maintain an orig. copy of it, create one, something like 'anarraycopy'.
 //  If you need only a shallow copy, use 'anarraycopy = anarray.slice(0);'
 //  A deep copy, depending on what kind of objects you have in the array, may be
 //  necessary.  The strategy for a deep copy will vary and is not discussed here.
 //  If you need merely to record the array's orig. size, set a local or
 //  global var equal to 'anarray.length;', depending on your needs.
 // - or -
 // plan to use 'counter' as if it was 'i' in a for(), as in
 // for(i=0; i < x; i++ {...}

   ...

   // Using 50 for example only.  Could be 100, etc. Good practice is to pick something
   // other than 0 due to Javascript engine processing; a 0 value is all but useless
   // since it takes time for Javascript to do anything. 50 seems to be good value to
   // use. It could be though that what value to use does  depend on how much time it
   // takes the code in func_c() to execute, so some profiling and knowing what the 
   // most likely deployed user base is going to be using might help. At the same 
   // time, this may make no difference.  Not entirely sure myself.  Also, 
   // using "'func_b()'" instead of just "func_b()" is critical.  I've found that the
   // callback will not occur unless you have the function in single-quotes.

   setTimeout('func_b()', 50);

  //  No more code after this.  function func_a() is now done.  It's important not to
  //  put any more code in after this point since setTimeout() does not act like
  //  Thread.sleep() in Java.  Processing just continues, and that is the problem
  //  you're trying to get around.

} // func_a()


function func_b()
{
 if( anarray.length == 0 )
 {
   // possibly do something here, relevant to your purposes
   return;
 }
//  -or- 
if( counter == x ) // 'x' is some value you want to go to.  It'll likely either
                   // be 0 (when counting down) or the max desired value you
                   // have for x if counting upward.
{
  // possibly do something here, relevant to your purposes
  return;
}

array_member = anarray[0];
anarray.splice(0,1); // Reduces 'anarray' by one member, the one at anarray[0].
                     // The one that was at anarray[1] is now at
                     // anarray[0] so will be used at the next iteration of func_b().

func_c();

setTimeout('func_b()', 50);

} // func_b()


function func_c()
{
  counter++; // If not using 'anarray'.  Possibly you would use
             // 'counter--' if you set 'counter' to the highest value
             // desired and are working your way backwards.

  // Here is where you have the code that would have been executed
  // in the for() loop.  Breaking out of it or doing a 'continue'
  // equivalent can be done with using 'return;' or canceling 
  // processing entirely can be done by setting a global var
  // to indicate the process is cancelled, then doing a 'return;', as in
  // 'bCancelOut = true; return;'.  Then in func_b() you would be evaluating
  // bCancelOut at the top to see if it was true.  If so, you'd just exit from
  // func_b() with a 'return;'

} // func_c()

How to get image height and width using java?

Here is something very simple and handy.

BufferedImage bimg = ImageIO.read(new File(filename));
int width          = bimg.getWidth();
int height         = bimg.getHeight();

MaxLength Attribute not generating client-side validation attributes

This can replace the MaxLength and the MinLength

[StringLength(40, MinimumLength = 10 , ErrorMessage = "Name cannot be longer than 40 characters and less than 10")]

How to use 'find' to search for files created on a specific date?

@Max: is right about the creation time.

However, if you want to calculate the elapsed days argument for one of the -atime, -ctime, -mtime parameters, you can use the following expression

ELAPSED_DAYS=$(( ( $(date +%s) - $(date -d '2008-09-24' +%s) ) / 60 / 60 / 24 - 1 ))

Replace "2008-09-24" with whatever date you want and ELAPSED_DAYS will be set to the number of days between then and today. (Update: subtract one from the result to align with find's date rounding.)

So, to find any file modified on September 24th, 2008, the command would be:

find . -type f -mtime $(( ( $(date +%s) - $(date -d '2008-09-24' +%s) ) / 60 / 60 / 24 - 1 ))

This will work if your version of find doesn't support the -newerXY predicates mentioned in @Arve:'s answer.

What is the .idea folder?

It contains your local IntelliJ IDE configs. I recommend adding this folder to your .gitignore file:

# intellij configs
.idea/

writing a batch file that opens a chrome URL

start "Chrome" "C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --profile-directory="Profile 2"

start "webpage name" "http://someurl.com/"

start "Chrome" "C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --profile-directory="Profile 3"

start "webpage name" "http://someurl.com/"

Git fast forward VS no fast forward merge

When we work on development environment and merge our code to staging/production branch then Git no fast forward can be a better option. Usually when we work in development branch for a single feature we tend to have multiple commits. Tracking changes with multiple commits can be inconvenient later on. If we merge with staging/production branch using Git no fast forward then it will have only 1 commit. Now anytime we want to revert the feature, just revert that commit. Life is easy.

Can anonymous class implement interface?

The best solution is just not to use anonymous classes.

public class Test
{
    class DummyInterfaceImplementor : IDummyInterface
    {
        public string A { get; set; }
        public string B { get; set; }
    }

    public void WillThisWork()
    {
        var source = new DummySource[0];
        var values = from value in source
                     select new DummyInterfaceImplementor()
                     {
                         A = value.A,
                         B = value.C + "_" + value.D
                     };

        DoSomethingWithDummyInterface(values.Cast<IDummyInterface>());

    }

    public void DoSomethingWithDummyInterface(IEnumerable<IDummyInterface> values)
    {
        foreach (var value in values)
        {
            Console.WriteLine("A = '{0}', B = '{1}'", value.A, value.B);
        }
    }
}

Note that you need to cast the result of the query to the type of the interface. There might be a better way to do it, but I couldn't find it.

Getting DOM element value using pure JavaScript

There is no difference if we look on effect - value will be the same. However there is something more...

Solution 3:

_x000D_
_x000D_
function doSomething() {_x000D_
  console.log( theId.value );_x000D_
}
_x000D_
<input id="theId" value="test" onclick="doSomething()" />
_x000D_
_x000D_
_x000D_

if DOM element has id then you can use it in js directly

Turn ON/OFF Camera LED/flash light in Samsung Galaxy Ace 2.2.1 & Galaxy Tab

I will soon released a new version of my app to support to galaxy ace.

You can download here: https://play.google.com/store/apps/details?id=droid.pr.coolflashlightfree

In order to solve your problem you should do this:

this._camera = Camera.open();     
this._camera.startPreview();
this._camera.autoFocus(new AutoFocusCallback() {
public void onAutoFocus(boolean success, Camera camera) {
}
});

Parameters params = this._camera.getParameters();
params.setFlashMode(Parameters.FLASH_MODE_ON);
this._camera.setParameters(params);

params = this._camera.getParameters();
params.setFlashMode(Parameters.FLASH_MODE_OFF);
this._camera.setParameters(params);

don't worry about FLASH_MODE_OFF because this will keep the light on, strange but it's true

to turn off the led just release the camera

How to stop C++ console application from exiting immediately?

The solution by James works for all Platforms.

Alternatively on Windows you can also add the following just before you return from main function:

  system("pause");

This will run the pause command which waits till you press a key and also displays a nice message Press any key to continue . . .

Generate PDF from Swagger API documentation

I created a web site https://www.swdoc.org/ that specifically addresses the problem. So it automates swagger.json -> Asciidoc, Asciidoc -> pdf transformation as suggested in the answers. Benefit of this is that you dont need to go through the installation procedures. It accepts a spec document in form of url or just a raw json. Project is written in C# and its page is https://github.com/Irdis/SwDoc

EDIT

It might be a good idea to validate your json specs here: http://editor.swagger.io/ if you are having any problems with SwDoc, like the pdf being generated incomplete.

How can I get the active screen dimensions?

WinForms

For multi-monitor setups you will also need account for the X and Y position:

Rectangle activeScreenDimensions = Screen.FromControl(this).Bounds;
this.Size = new Size(activeScreenDimensions.Width + activeScreenDimensions.X, activeScreenDimensions.Height + activeScreenDimensions.Y);

get basic SQL Server table structure information

Instead of using count(*) you can SELECT * and you will return all of the details that you want including data_type:

SELECT *
FROM INFORMATION_SCHEMA.COLUMNS
WHERE table_name = 'Address'

MSDN Docs on INFORMATION_SCHEMA.COLUMNS

Remove columns from DataTable in C#

To remove all columns after the one you want, below code should work. It will remove at index 10 (remember Columns are 0 based), until the Column count is 10 or less.

DataTable dt;
int desiredSize = 10;

while (dt.Columns.Count > desiredSize)
{
   dt.Columns.RemoveAt(desiredSize);
}

How do I bind a List<CustomObject> to a WPF DataGrid?

You dont need to give column names manually in xaml. Just set AutoGenerateColumns property to true and your list will be automatically binded to DataGrid. refer code. XAML Code:

<Grid>
    <DataGrid x:Name="MyDatagrid" AutoGenerateColumns="True" Height="447" HorizontalAlignment="Left" Margin="20,85,0,0" VerticalAlignment="Top" Width="799"  ItemsSource="{Binding Path=ListTest, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"  CanUserAddRows="False"> </Grid>

C#

Public Class Test 
{
    public string m_field1_Test{get;set;}
    public string m_field2_Test { get; set; }
    public Test()
    {
        m_field1_Test = "field1";
        m_field2_Test = "field2";
    }
    public MainWindow()
    {

        listTest = new List<Test>();

        for (int i = 0; i < 10; i++)
        {
            obj = new Test();
            listTest.Add(obj);

        }

        this.MyDatagrid.ItemsSource = ListTest;

        InitializeComponent();

    }

Remove trailing comma from comma-separated string

To remove the ", " part which is immediately followed by end of string, you can do:

str = str.replaceAll(", $", "");

This handles the empty list (empty string) gracefully, as opposed to lastIndexOf / substring solutions which requires special treatment of such case.

Example code:

String str = "kushalhs, mayurvm, narendrabz, ";
str = str.replaceAll(", $", "");
System.out.println(str);  // prints "kushalhs, mayurvm, narendrabz"

NOTE: Since there has been some comments and suggested edits about the ", $" part: The expression should match the trailing part that you want to remove.

  • If your input looks like "a,b,c,", use ",$".
  • If your input looks like "a, b, c, ", use ", $".
  • If your input looks like "a , b , c , ", use " , $".

I think you get the point.

IIS URL Rewrite and Web.config

1) Your existing web.config: you have declared rewrite map .. but have not created any rules that will use it. RewriteMap on its' own does absolutely nothing.

2) Below is how you can do it (it does not utilise rewrite maps -- rules only, which is fine for small amount of rewrites/redirects):

This rule will do SINGLE EXACT rewrite (internal redirect) /page to /page.html. URL in browser will remain unchanged.

<system.webServer>
    <rewrite>
        <rules>
            <rule name="SpecificRewrite" stopProcessing="true">
                <match url="^page$" />
                <action type="Rewrite" url="/page.html" />
            </rule>
        </rules>
    </rewrite>
</system.webServer>

This rule #2 will do the same as above, but will do 301 redirect (Permanent Redirect) where URL will change in browser.

<system.webServer>
    <rewrite>
        <rules>
            <rule name="SpecificRedirect" stopProcessing="true">
                <match url="^page$" />
                <action type="Redirect" url="/page.html" />
            </rule>
        </rules>
    </rewrite>
</system.webServer>

Rule #3 will attempt to execute such rewrite for ANY URL if there are such file with .html extension (i.e. for /page it will check if /page.html exists, and if it does then rewrite occurs):

<system.webServer>
    <rewrite>
        <rules>
            <rule name="DynamicRewrite" stopProcessing="true">
                <match url="(.*)" />
                <conditions>
                    <add input="{REQUEST_FILENAME}\.html" matchType="IsFile" />
                </conditions>
                <action type="Rewrite" url="/{R:1}.html" />
            </rule>
        </rules>
    </rewrite>
</system.webServer>

Get Character value from KeyCode in JavaScript... then trim

For those of you who came here looking for the actual Unicode character values for a keycode, like I did, here is a function for that. For instance, given the right arrow unicode keycode this will output the visible string \u001B\u005B\u0043

function toUnicode(theString) {
    var unicodeString = '';
    for (var i = 0; i < theString.length; i++) {
        var theUnicode = theString.charCodeAt(i).toString(16).toUpperCase();
        while (theUnicode.length < 4) {
            theUnicode = '0' + theUnicode;
        }
        theUnicode = '\\u' + theUnicode;
        unicodeString += theUnicode;
    }
    return unicodeString;
}

Right way to split an std::string into a vector<string>

A convenient way would be boost's string algorithms library.

#include <boost/algorithm/string/classification.hpp> // Include boost::for is_any_of
#include <boost/algorithm/string/split.hpp> // Include for boost::split
// ...

std::vector<std::string> words;
std::string s;
boost::split(words, s, boost::is_any_of(", "), boost::token_compress_on);

Split string into tokens and save them in an array

Why strtok() is a bad idea

Do not use strtok() in normal code, strtok() uses static variables which have some problems. There are some use cases on embedded microcontrollers where static variables make sense but avoid them in most other cases. strtok() behaves unexpected when more than 1 thread uses it, when it is used in a interrupt or when there are some other circumstances where more than one input is processed between successive calls to strtok(). Consider this example:

#include <stdio.h>
#include <string.h>

//Splits the input by the / character and prints the content in between
//the / character. The input string will be changed
void printContent(char *input)
{
    char *p = strtok(input, "/");
    while(p)
    {
        printf("%s, ",p);
        p = strtok(NULL, "/");
    }
}

int main(void)
{
    char buffer[] = "abc/def/ghi:ABC/DEF/GHI";
    char *p = strtok(buffer, ":");
    while(p)
    {
        printContent(p);
        puts(""); //print newline
        p = strtok(NULL, ":");
    }
    return 0;
}

You may expect the output:

abc, def, ghi,
ABC, DEF, GHI,

But you will get

abc, def, ghi,

This is because you call strtok() in printContent() resting the internal state of strtok() generated in main(). After returning, the content of strtok() is empty and the next call to strtok() returns NULL.

What you should do instead

You could use strtok_r() when you use a POSIX system, this versions does not need static variables. If your library does not provide strtok_r() you can write your own version of it. This should not be hard and Stackoverflow is not a coding service, you can write it on your own.

how to show alternate image if source image is not found? (onerror working in IE but not in mozilla)

I have got the solution for my query:

i have done something like this:

cell.innerHTML="<img height=40 width=40 alt='' src='<%=request.getContextPath()%>/writeImage.htm?' onerror='onImgError(this);' onLoad='setDefaultImage(this);'>"

function setDefaultImage(source){
        var badImg = new Image();
        badImg.src = "video.png";
        var cpyImg = new Image();
        cpyImg.src = source.src;

        if(!cpyImg.width)
        {
            source.src = badImg.src;
        }

    }


    function onImgError(source){
        source.src = "video.png";
        source.onerror = ""; 
        return true; 
    } 

This way it's working in all browsers.

Extract names of objects from list

You can just use:

> names(LIST)
[1] "A" "B"

Obviously the names of the first element is just

> names(LIST)[1]
[1] "A"

How to convert a char to a String?

Here are a few methods, in no particular order:

char c = 'c';

String s = Character.toString(c); // Most efficient way

s = new Character(c).toString(); // Same as above except new Character objects needs to be garbage-collected

s = c + ""; // Least efficient and most memory-inefficient, but common amongst beginners because of its simplicity

s = String.valueOf(c); // Also quite common

s = String.format("%c", c); // Not common

Formatter formatter = new Formatter();
s = formatter.format("%c", c).toString(); // Same as above
formatter.close();

Connection timeout for SQL server

If you want to dynamically change it, I prefer using SqlConnectionStringBuilder .

It allows you to convert ConnectionString i.e. a string into class Object, All the connection string properties will become its Member.

In this case the real advantage would be that you don't have to worry about If the ConnectionTimeout string part is already exists in the connection string or not?

Also as it creates an Object and its always good to assign value in object rather than manipulating string.

Here is the code sample:

var sscsb = new SqlConnectionStringBuilder(_dbFactory.Database.ConnectionString);

sscsb.ConnectTimeout = 30;

var conn = new SqlConnection(sscsb.ConnectionString);

Extend contigency table with proportions (percentages)

Your code doesn't seem so ugly to me...
however, an alternative (not much better) could be e.g. :

df <- data.frame(table(yn))
colnames(df) <- c('Smoker','Freq')
df$Perc <- df$Freq / sum(df$Freq) * 100

------------------
  Smoker Freq Perc
1     No   19 47.5
2    Yes   21 52.5

How to call external JavaScript function in HTML

If a <script> has a src then the text content of the element will be not be executed as JS (although it will appear in the DOM).

You need to use multiple script elements.

  1. a <script> to load the external script
  2. a <script> to hold your inline code (with the call to the function in the external script)

    scroll_messages();

With ng-bind-html-unsafe removed, how do I inject HTML?

I've had a similar problem. Still couldn't get content from my markdown files hosted on github.

After setting up a whitelist (with added github domain) to the $sceDelegateProvider in app.js it worked like a charm.

Description: Using a whitelist instead of wrapping as trusted if you load content from a different urls.

Docs: $sceDelegateProvider and ngInclude (for fetching, compiling and including external HTML fragment)

WSDL vs REST Pros and Cons

SOAP: It can be transported via SMTP also, means we can invoke the service using Email simple text format also

It needs additional framework/engine should be in web service consumer machine to convert SOAP message to respective objects structure in various languages.

REST: Now WSDL2.0 supports to describe REST web service also

We can use when you want to make your service as lightweight, example calling from mobile devices like cell phone, pda etc...

Android camera android.hardware.Camera deprecated

Answers provided here as which camera api to use are wrong. Or better to say they are insufficient.

Some phones (for example Samsung Galaxy S6) could be above api level 21 but still may not support Camera2 api.

CameraCharacteristics mCameraCharacteristics = mCameraManager.getCameraCharacteristics(mCameraId);
Integer level = mCameraCharacteristics.get(CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL);
if (level == null || level == CameraCharacteristics.INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY) {
    return false;
}

CameraManager class in Camera2Api has a method to read camera characteristics. You should check if hardware wise device is supporting Camera2 Api or not.

But there are more issues to handle if you really want to make it work for a serious application: Like, auto-flash option may not work for some devices or battery level of the phone might create a RuntimeException on Camera or phone could return an invalid camera id and etc.

So best approach is to have a fallback mechanism as for some reason Camera2 fails to start you can try Camera1 and if this fails as well you can make a call to Android to open default Camera for you.

How do you set the document title in React?

You can use React Helmet:

import React from 'react'
import { Helmet } from 'react-helmet'

const TITLE = 'My Page Title'

class MyComponent extends React.PureComponent {
  render () {
    return (
      <>
        <Helmet>
          <title>{ TITLE }</title>
        </Helmet>
        ...
      </>
    )
  }
}

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

It's \n. When you're reading or writing text mode files, or to stdin/stdout etc, you must use \n, and C will handle the translation for you. When you're dealing with binary files, by definition you are on your own.

Send HTML in email via PHP

You can easily send the email with HTML content via PHP. Use the following script.

<?php
$to = '[email protected]';
$subject = "Send HTML Email Using PHP";

$htmlContent = '
<html>
<body>
    <h1>Send HTML Email Using PHP</h1>
    <p>This is a HTMl email using PHP by CodexWorld</p>
</body>
</html>';

// Set content-type header for sending HTML email
$headers = "MIME-Version: 1.0" . "\r\n";
$headers .= "Content-type:text/html;charset=UTF-8" . "\r\n";

// Additional headers
$headers .= 'From: CodexWorld<[email protected]>' . "\r\n";
$headers .= 'Cc: [email protected]' . "\r\n";
$headers .= 'Bcc: [email protected]' . "\r\n";

// Send email
if(mail($to,$subject,$htmlContent,$headers)):
    $successMsg = 'Email has sent successfully.';
else:
    $errorMsg = 'Email sending fail.';
endif;
?>

Source code and live demo can be found from here - Send Beautiful HTML Email using PHP

How to remove the first Item from a list?

you would just do this

l = [0, 1, 2, 3, 4]
l.pop(0)

or l = l[1:]

Pros and Cons

Using pop you can retrieve the value

say x = l.pop(0) x would be 0

Linq where clause compare only date value without time value

Do not simplify the code to avoid "linq translation error": The test consist between a date with time at 0:0:0 and the same date with time at 23:59:59

        iFilter.MyDate1 = DateTime.Today;  // or DateTime.MinValue

        // GET 
        var tempQuery = ctx.MyTable.AsQueryable();

        if (iFilter.MyDate1 != DateTime.MinValue)
        {
            TimeSpan temp24h = new TimeSpan(23,59,59);
            DateTime tempEndMyDate1 = iFilter.MyDate1.Add(temp24h);

            // DO not change the code below, you need 2 date variables...
            tempQuery = tempQuery.Where(w => w.MyDate2 >= iFilter.MyDate1
                                          && w.MyDate2 <= tempEndMyDate1);
        }

        List<MyTable> returnObject = tempQuery.ToList();

Coloring Buttons in Android with Material Design and AppCompat

I actually didn't want a change to my custom button styles but unfortunately they weren't working anymore.

My App has a minSdkVersion of 9 and everything worked before.

I don't know why but since I removed the android: before the buttonStyle it seems to work again

now = working:

<item name="buttonStyle">@style/ButtonmyTime</item>

before = just gray material buttons:

<item name="android:buttonStyle">@style/ButtonmyTime</item>

I have no spezial folder for newver android version since my buttons are quite flat and they should look the same across all android versions.

Maybe someone can tell me why I had to remove the "android:" The ImageButton is still working with "android:"

<item name="android:imageButtonStyle">@style/ImageButtonmyTimeGreen</item>

Throwing exceptions in a PHP Try Catch block

Throw needs an object instantiated by \Exception. Just the $e catched can play the trick.

throw $e

JavaScript - Hide a Div at startup (load)

Using CSS you can just set display:none for the element in a CSS file or in a style attribute

#div { display:none; }
<div id="div"></div>



<div style="display:none"></div>

or having the js just after the div might be fast enough too, but not as clean

Angular-cli from css to scss

For existing projects:

In angular.json file

  1. In build part and in test part, replace:

    "styles": ["src/styles.css"], by "styles": ["src/styles.scss"],

  2. Replace:

    "schematics": {}, by "schematics": { "@schematics/angular:component": { "style": "scss" } },

Using ng config schematics.@schematics/angular:component.styleext scss command works but it does not place the configuration in the same place.

In your project rename your .css files to .scss

For a new project, this command do all the work:

ng n project-name --style=scss

For global configuration

New versions seems to not have a global command

Converting XML to JSON using Python?

Well, probably the simplest way is just parse the XML into dictionaries and then serialize that with simplejson.

How to check syslog in Bash on Linux?

tail -f /var/log/syslog | grep process_name where process_name is the name of the process we are interested in

COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better?

Bottom Line

Use either COUNT(field) or COUNT(*), and stick with it consistently, and if your database allows COUNT(tableHere) or COUNT(tableHere.*), use that.

In short, don't use COUNT(1) for anything. It's a one-trick pony, which rarely does what you want, and in those rare cases is equivalent to count(*)

Use count(*) for counting

Use * for all your queries that need to count everything, even for joins, use *

SELECT boss.boss_id, COUNT(subordinate.*)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

But don't use COUNT(*) for LEFT joins, as that will return 1 even if the subordinate table doesn't match anything from parent table

SELECT boss.boss_id, COUNT(*)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

Don't be fooled by those advising that when using * in COUNT, it fetches entire row from your table, saying that * is slow. The * on SELECT COUNT(*) and SELECT * has no bearing to each other, they are entirely different thing, they just share a common token, i.e. *.

An alternate syntax

In fact, if it is not permitted to name a field as same as its table name, RDBMS language designer could give COUNT(tableNameHere) the same semantics as COUNT(*). Example:

For counting rows we could have this:

SELECT COUNT(emp) FROM emp

And they could make it simpler:

SELECT COUNT() FROM emp

And for LEFT JOINs, we could have this:

SELECT boss.boss_id, COUNT(subordinate)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

But they cannot do that (COUNT(tableNameHere)) since SQL standard permits naming a field with the same name as its table name:

CREATE TABLE fruit -- ORM-friendly name
(
fruit_id int NOT NULL,
fruit varchar(50), /* same name as table name, 
                and let's say, someone forgot to put NOT NULL */
shape varchar(50) NOT NULL,
color varchar(50) NOT NULL
)

Counting with null

And also, it is not a good practice to make a field nullable if its name matches the table name. Say you have values 'Banana', 'Apple', NULL, 'Pears' on fruit field. This will not count all rows, it will only yield 3, not 4

SELECT count(fruit) FROM fruit

Though some RDBMS do that sort of principle (for counting the table's rows, it accepts table name as COUNT's parameter), this will work in Postgresql (if there is no subordinate field in any of the two tables below, i.e. as long as there is no name conflict between field name and table name):

SELECT boss.boss_id, COUNT(subordinate)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

But that could cause confusion later if we will add a subordinate field in the table, as it will count the field(which could be nullable), not the table rows.

So to be on the safe side, use:

SELECT boss.boss_id, COUNT(subordinate.*)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

count(1): The one-trick pony

In particular to COUNT(1), it is a one-trick pony, it works well only on one table query:

SELECT COUNT(1) FROM tbl

But when you use joins, that trick won't work on multi-table queries without its semantics being confused, and in particular you cannot write:

-- count the subordinates that belongs to boss
SELECT boss.boss_id, COUNT(subordinate.1)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

So what's the meaning of COUNT(1) here?

SELECT boss.boss_id, COUNT(1)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

Is it this...?

-- counting all the subordinates only
SELECT boss.boss_id, COUNT(subordinate.boss_id)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

Or this...?

-- or is that COUNT(1) will also count 1 for boss regardless if boss has a subordinate
SELECT boss.boss_id, COUNT(*)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

By careful thought, you can infer that COUNT(1) is the same as COUNT(*), regardless of type of join. But for LEFT JOINs result, we cannot mold COUNT(1) to work as: COUNT(subordinate.boss_id), COUNT(subordinate.*)

So just use either of the following:

-- count the subordinates that belongs to boss
SELECT boss.boss_id, COUNT(subordinate.boss_id)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

Works on Postgresql, it's clear that you want to count the cardinality of the set

-- count the subordinates that belongs to boss
SELECT boss.boss_id, COUNT(subordinate.*)
FROM boss
LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id
GROUP BY boss.id

Another way to count the cardinality of the set, very English-like (just don't make a column with a name same as its table name) : http://www.sqlfiddle.com/#!1/98515/7

select boss.boss_name, count(subordinate)
from boss
left join subordinate on subordinate.boss_code = boss.boss_code
group by boss.boss_name

You cannot do this: http://www.sqlfiddle.com/#!1/98515/8

select boss.boss_name, count(subordinate.1)
from boss
left join subordinate on subordinate.boss_code = boss.boss_code
group by boss.boss_name

You can do this, but this produces wrong result: http://www.sqlfiddle.com/#!1/98515/9

select boss.boss_name, count(1)
from boss
left join subordinate on subordinate.boss_code = boss.boss_code
group by boss.boss_name

How to change a text with jQuery

Something like this should do the trick:

$(document).ready(function() {
    $('#toptitle').text(function(i, oldText) {
        return oldText === 'Profil' ? 'New word' : oldText;
    });
});

This only replaces the content when it is Profil. See text in the jQuery API.

Set proxy through windows command line including login parameters

If you are using Microsoft windows environment then you can set a variable named HTTP_PROXY, FTP_PROXY, or HTTPS_PROXY depending on the requirement.

I have used following settings for allowing my commands at windows command prompt to use the browser proxy to access internet.

set HTTP_PROXY=http://proxy_userid:proxy_password@proxy_ip:proxy_port

The parameters on right must be replaced with actual values.

Once the variable HTTP_PROXY is set, all our subsequent commands executed at windows command prompt will be able to access internet through the proxy along with the authentication provided.

Additionally if you want to use ftp and https as well to use the same proxy then you may like to the following environment variables as well.

set FTP_PROXY=%HTTP_PROXY%

set HTTPS_PROXY=%HTTP_PROXY%

getCurrentPosition() and watchPosition() are deprecated on insecure origins

Found a likely answer in /jstillwell's posts here: https://github.com/stefanocudini/leaflet-gps/issues/15 basically this feature will not be supported (in Chrome only?) in the future, but only for HTTP sites. HTTPS will still be ok, and there are no plans to create an equivalent replacement for HTTP use.

What are the best practices for SQLite on Android?

I know that the response is late, but the best way to execute sqlite queries in android is through a custom content provider. In that way the UI is decoupled with the database class(the class that extends the SQLiteOpenHelper class). Also the queries are executed in a background thread(Cursor Loader).

How to convert byte array to string and vice versa?

The "proper conversion" between byte[] and String is to explicitly state the encoding you want to use. If you start with a byte[] and it does not in fact contain text data, there is no "proper conversion". Strings are for text, byte[] is for binary data, and the only really sensible thing to do is to avoid converting between them unless you absolutely have to.

If you really must use a String to hold binary data then the safest way is to use Base64 encoding.

How to detect browser using angularjs?

Like Eliran Malka asked, why do you need to check for IE 9?

Detecting browser make and version is generally a bad smell. This generally means that you there is a bigger problem with the code if you need JavaScript to detect specific versions of browser.

There are genuine cases where a feature won't work, like say WebSockets isn't supported in IE 8 or 9. This should be solved by checking for WebSocket support, and applying a polyfill if there is no native support.

This should be done with a library like Modernizr.

That being said, you can easily create service that would return the browser. There are valid cases where a feature exists in a browser but the implementation is outdated or broken. Modernizr is not appropriate for these cases.

app.service('browser', ['$window', function($window) {

     return function() {

         var userAgent = $window.navigator.userAgent;

        var browsers = {chrome: /chrome/i, safari: /safari/i, firefox: /firefox/i, ie: /internet explorer/i};

        for(var key in browsers) {
            if (browsers[key].test(userAgent)) {
                return key;
            }
       };

       return 'unknown';
    }

}]);

Fixed typo broswers

Note: This is just an example of how to create a service in angular that will sniff the userAgent string. This is just a code example that is not expected to work in production and report all browsers in all situations.

UPDATE

It is probably best to use a third party library like https://github.com/ded/bowser or https://github.com/darcyclarke/Detect.js. These libs place an object on the window named bowser or detect respectively.

You can then expose this to the Angular IoC Container like this:

angular.module('yourModule').value('bowser', bowser);

Or

detectFactory.$inject = ['$window'];
function detectFactory($window) {
    return detect.parse($window.navigator.userAgent);
} 
angular.module('yourModule').factory('detect', detectFactory);

You would then inject one of these the usual way, and use the API provided by the lib. If you choose to use another lib that instead uses a constructor method, you would create a factory that instantiates it:

function someLibFactory() {
    return new SomeLib();
}
angular.module('yourModule').factory('someLib', someLibFactory);

You would then inject this into your controllers and services the normal way.

If the library you are injecting does not exactly match your requirements, you may want to employ the Adapter Pattern where you create a class/constructor with the exact methods you need.

In this example we just need to test for IE 9, and we are going to use the bowser lib above.

BrowserAdapter.$inject = ['bowser']; // bring in lib
function BrowserAdapter(bowser) {
    this.bowser = bowser;
}

BrowserAdapter.prototype.isIe9 = function() {
    return this.bowser.msie && this.browser.version == 9;
}

angular.module('yourModule').service('browserAdapter', BrowserAdapter);

Now in a controller or service you can inject the browserAdapter and just do if (browserAdapter.isIe9) { // do something }

If later you wanted to use detect instead of bowser, the changes in your code would be isolated to the BrowserAdapter.

UPDATE

In reality these values never change. IF you load the page in IE 9 it will never become Chrome 44. So instead of registering the BrowserAdapter as a service, just put the result in a value or constant.

angular.module('app').value('isIe9', broswerAdapter.isIe9);

How to install Python packages from the tar.gz file without using pip install

Thanks to the answers below combined I've got it working.

  • First needed to unpack the tar.gz file into a folder.
  • Then before running python setup.py install had to point cmd towards the correct folder. I did this by pushd C:\Users\absolutefilepathtotarunpackedfolder
  • Then run python setup.py install

Thanks Tales Padua & Hugo Honorem

2D cross-platform game engine for Android and iOS?

Here is just a reply from Richard Pickup on LinkedIn to a similar question of mine:

I've used cocos 2dx marmalade and unity on both iOS and android. For 2d games cocos2dx is the way to go every time. Unity is just too much overkill for 2d games and as already stated marmalade is just a thin abstraction layer not really a game engine. You can even run cocos2d on top of marmalade. My approach would be to use cocos2dx on iOS and android then in future run cocosd2dx code on top of marmalade as an easy way to port to bb10 and win phone 7

Can regular expressions be used to match nested patterns?

No. It's that easy. A finite automaton (which is the data structure underlying a regular expression) does not have memory apart from the state it's in, and if you have arbitrarily deep nesting, you need an arbitrarily large automaton, which collides with the notion of a finite automaton.

You can match nested/paired elements up to a fixed depth, where the depth is only limited by your memory, because the automaton gets very large. In practice, however, you should use a push-down automaton, i.e a parser for a context-free grammar, for instance LL (top-down) or LR (bottom-up). You have to take the worse runtime behavior into account: O(n^3) vs. O(n), with n = length(input).

There are many parser generators avialable, for instance ANTLR for Java. Finding an existing grammar for Java (or C) is also not difficult.
For more background: Automata Theory at Wikipedia

How to pass an array into a function, and return the results with an array

Try

$waffles = foo($waffles);

Or pass the array by reference, like suggested in the other answers.

In addition, you can add new elements to an array without writing the index, e.g.

$waffles = array(1,2,3); // filling on initialization

or

$waffles = array();
$waffles[] = 1;
$waffles[] = 2;
$waffles[] = 3;

On a sidenote, if you want to sum all values in an array, use array_sum()

Check if a parameter is null or empty in a stored procedure

I use coalesce:

IF ( COALESCE( @PreviousStartDate, '' ) = '' ) ...

What is resource-ref in web.xml used for?

You can always refer to resources in your application directly by their JNDI name as configured in the container, but if you do so, essentially you are wiring the container-specific name into your code. This has some disadvantages, for example, if you'll ever want to change the name later for some reason, you'll need to update all the references in all your applications, and then rebuild and redeploy them.

<resource-ref> introduces another layer of indirection: you specify the name you want to use in the web.xml, and, depending on the container, provide a binding in a container-specific configuration file.

So here's what happens: let's say you want to lookup the java:comp/env/jdbc/primaryDB name. The container finds that web.xml has a <resource-ref> element for jdbc/primaryDB, so it will look into the container-specific configuration, that contains something similar to the following:

<resource-ref>
  <res-ref-name>jdbc/primaryDB</res-ref-name>
  <jndi-name>jdbc/PrimaryDBInTheContainer</jndi-name>
</resource-ref>

Finally, it returns the object registered under the name of jdbc/PrimaryDBInTheContainer.

The idea is that specifying resources in the web.xml has the advantage of separating the developer role from the deployer role. In other words, as a developer, you don't have to know what your required resources are actually called in production, and as the guy deploying the application, you will have a nice list of names to map to real resources.

Java String.split() Regex

str.split (" ") 
res27: Array[java.lang.String] = Array(a, +, b, -, c, *, d, /, e, <, f, >, g, >=, h, <=, i, ==, j)

Unrecognized attribute 'targetFramework'. Note that attribute names are case-sensitive

In IIS

Click on Application Pools

Right Click on DefaultAppPool --->> Set Application Pool Default....--->>Change .Net Version to V 4.0.

Letsencrypt add domain to existing certificate

Apache on Ubuntu, using the Apache plugin:

sudo certbot certonly --cert-name example.com -d m.example.com,www.m.example.com

The above command is vividly explained in the Certbot user guide on changing a certificate's domain names. Note that the command for changing a certificate's domain names applies to adding new domain names as well.

Edit

If running the above command gives you the error message

Client with the currently selected authenticator does not support any combination of challenges that will satisfy the CA.

follow these instructions from the Let's Encrypt Community

Ruby - ignore "exit" in code

One hackish way to define an exit method in context:

class Bar; def exit; end; end 

This works because exit in the initializer will be resolved as self.exit1. In addition, this approach allows using the object after it has been created, as in: b = B.new.

But really, one shouldn't be doing this: don't have exit (or even puts) there to begin with.

(And why is there an "infinite" loop and/or user input in an intiailizer? This entire problem is primarily the result of poorly structured code.)


1 Remember Kernel#exit is only a method. Since Kernel is included in every Object, then it's merely the case that exit normally resolves to Object#exit. However, this can be changed by introducing an overridden method as shown - nothing fancy.

Get data from fs.readFile

var fs = require('fs');
var path = (process.cwd()+"\\text.txt");

fs.readFile(path , function(err,data)
{
    if(err)
        console.log(err)
    else
        console.log(data.toString());
});

Debugging with command-line parameters in Visual Studio

Yes, it's in the Debugging section of the properties page of the project.

In Visual Studio since 2008: right-click the project, choose Properties, go to the Debugging section -- there is a box for "Command Arguments". (Tip: not solution, but project).

check if file exists in php

You can also use PHP get_headers() function.

Example:

function check_file_exists_here($url){
   $result=get_headers($url);
   return stripos($result[0],"200 OK")?true:false; //check if $result[0] has 200 OK
}

if(check_file_exists_here("http://www.mywebsite.com/file.pdf"))
   echo "This file exists";
else
   echo "This file does not exist";

How to clear PermGen space Error in tomcat

In Tomcat 7.0 Windows Service Installer Version.There is not catalina.bat in /bin . So you need open Tomcat7w.exe in /bin and add blow JVM argument

-XX:PermSize=256m -XX:MaxPermSize=512m

on Java Option in Java Tab, like this. You also add other options.

enter image description here

Another, if you use IntellijIDEA you need add JVM argument in Server Configurations,like this.

enter image description here

What do curly braces mean in Verilog?

As Matt said, the curly braces are for concatenation. The extra curly braces around 16{a[15]} are the replication operator. They are described in the IEEE Standard for Verilog document (Std 1364-2005), section "5.1.14 Concatenations".

{16{a[15]}}

is the same as

{ 
   a[15], a[15], a[15], a[15], a[15], a[15], a[15], a[15],
   a[15], a[15], a[15], a[15], a[15], a[15], a[15], a[15]
}

In bit-blasted form,

assign result = {{16{a[15]}}, {a[15:0]}};

is the same as:

assign result[ 0] = a[ 0];
assign result[ 1] = a[ 1];
assign result[ 2] = a[ 2];
assign result[ 3] = a[ 3];
assign result[ 4] = a[ 4];
assign result[ 5] = a[ 5];
assign result[ 6] = a[ 6];
assign result[ 7] = a[ 7];
assign result[ 8] = a[ 8];
assign result[ 9] = a[ 9];
assign result[10] = a[10];
assign result[11] = a[11];
assign result[12] = a[12];
assign result[13] = a[13];
assign result[14] = a[14];
assign result[15] = a[15];
assign result[16] = a[15];
assign result[17] = a[15];
assign result[18] = a[15];
assign result[19] = a[15];
assign result[20] = a[15];
assign result[21] = a[15];
assign result[22] = a[15];
assign result[23] = a[15];
assign result[24] = a[15];
assign result[25] = a[15];
assign result[26] = a[15];
assign result[27] = a[15];
assign result[28] = a[15];
assign result[29] = a[15];
assign result[30] = a[15];
assign result[31] = a[15];