Programs & Examples On #Watermark

A watermark is information embedded within a file. In the most common usage, watermarks are added to images to identify the image's creator.

Watermark / hint text / placeholder TextBox

This technique uses the Background property to show / hide placeholder textbox.
Placeholder is shown event when Textbox has the focus

How it works:

  • When empty, TextBox background set to Transparent to show PlaceHolder text.
  • When not empty background set to White to cover up PlaceHolder text.

Here is basic example. For my own purposes I turned this into a UserControl.

<Grid>
    <Grid.Resources>
        <ux:NotEmptyConverter x:Key="NotEmptyConverter" />

        <Style TargetType="{x:Type Control}" x:Key="DefaultStyle">
            <Setter Property="FontSize" Value="20" />
            <Setter Property="Margin" Value="10"/>
            <Setter Property="VerticalAlignment" Value="Center"></Setter>
            <Setter Property="VerticalContentAlignment" Value="Center"></Setter>
        </Style>

        <Style TargetType="{x:Type TextBox}" BasedOn="{StaticResource DefaultStyle}"></Style>

    </Grid.Resources>

    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
    </Grid.RowDefinitions>
    <TextBox Grid.Row="0" Text="Placeholder Text Is Here" Foreground="DarkGray" />
    <TextBox Grid.Row="0" Name="TextBoxEdit" 
            Text="{Binding Path=FirstName, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" >
        <TextBox.Style>
            <Style TargetType="{x:Type TextBox}" BasedOn="{StaticResource DefaultStyle}">
                <Style.Triggers>
                    <DataTrigger Binding="{Binding Path=FirstName.Length, FallbackValue=0, TargetNullValue=0}" Value="0">
                        <Setter Property="Background" Value="Transparent"/>
                    </DataTrigger>
                    <DataTrigger Binding="{Binding Path=FirstName, FallbackValue=0, TargetNullValue=0, Converter={StaticResource NotEmptyConverter}}" Value="false">
                        <Setter Property="Background" Value="White"/>
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </TextBox.Style>
    </TextBox>
</Grid>

Here is the ValueConverter to detect non-empty strings in the DataTrigger.

public class NotEmptyConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        var s = value as string;
        return string.IsNullOrEmpty(s);
    }
    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        return null;
    }
}

Creating watermark using html and css

I would recommend everyone look into CSS grids. It has been supported by most browsers now since about 2017. Here is a link to some documentation: https://css-tricks.com/snippets/css/complete-guide-grid/ . It is so much easier to keep your page elements where you want them, especially when it comes to responsiveness. It took me all of 20 minutes to learn how to do it, and I'm a newbie!

<div class="grid-div">
    <p class="hello">Hello</p>
    <p class="world">World</p>
</div>


//begin css//

.grid-div {
    display: grid;
    grid-template-columns: 50% 50%;
    grid-template-rows: 50% 50%;
}

.hello {
    grid-column-start: 2;
    grid-row-start: 2;
}

.world {
    grid-column-start: 1;
    grid-row-start: 2;
}

This code will split the page into 4 equal quadrants, placing the "Hello" in the bottom right, and the "World" in the bottom left without having to change their positioning or playing with margins.

This can be extrapolated into very complex grid layouts with overlapping, infinite grids of all sizes, and even grids nested inside grids, without losing control of your elements every time something changes (MS Word I'm looking at you).

Hope this helps whoever still needs it!

Impersonate tag in Web.Config

The identity section goes under the system.web section, not under authentication:

<system.web>
  <authentication mode="Windows"/>
  <identity impersonate="true" userName="foo" password="bar"/>
</system.web>

Return index of highest value in an array

My solution is:

$maxs = array_keys($array, max($array))

Note:
this way you can retrieve every key related to a given max value.

If you are interested only in one key among all simply use $maxs[0]

How to add custom html attributes in JSX

Consider you want to pass a custom attribute named myAttr with value myValue, this will work:

<MyComponent data-myAttr={myValue} />

HTML / CSS Popup div on text click

DEMO

In the content area you can provide whatever you want to display in it.

_x000D_
_x000D_
.black_overlay {_x000D_
  display: none;_x000D_
  position: absolute;_x000D_
  top: 0%;_x000D_
  left: 0%;_x000D_
  width: 100%;_x000D_
  height: 100%;_x000D_
  background-color: black;_x000D_
  z-index: 1001;_x000D_
  -moz-opacity: 0.8;_x000D_
  opacity: .80;_x000D_
  filter: alpha(opacity=80);_x000D_
}_x000D_
.white_content {_x000D_
  display: none;_x000D_
  position: absolute;_x000D_
  top: 25%;_x000D_
  left: 25%;_x000D_
  width: 50%;_x000D_
  height: 50%;_x000D_
  padding: 16px;_x000D_
  border: 16px solid orange;_x000D_
  background-color: white;_x000D_
  z-index: 1002;_x000D_
  overflow: auto;_x000D_
}
_x000D_
<html>_x000D_
_x000D_
<head>_x000D_
  <title>LIGHTBOX EXAMPLE</title>_x000D_
</head>_x000D_
_x000D_
<body>_x000D_
  <p>This is the main content. To display a lightbox click <a href="javascript:void(0)" onclick="document.getElementById('light').style.display='block';document.getElementById('fade').style.display='block'">here</a>_x000D_
  </p>_x000D_
  <div id="light" class="white_content">This is the lightbox content. <a href="javascript:void(0)" onclick="document.getElementById('light').style.display='none';document.getElementById('fade').style.display='none'">Close</a>_x000D_
  </div>_x000D_
  <div id="fade" class="black_overlay"></div>_x000D_
</body>_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_

RestSharp simple complete example

Changing

RestResponse response = client.Execute(request);

to

IRestResponse response = client.Execute(request);

worked for me.

Can I use library that used android support with Androidx projects.

I used these two lines of code in application tag in manifest.xml and it worked.

 tools:replace="android:appComponentFactory"    
 android:appComponentFactory="whateverString"

Source: https://github.com/android/android-ktx/issues/576#issuecomment-437145192

Get contentEditable caret index position

_x000D_
_x000D_
$("#editable").on('keydown keyup mousedown mouseup',function(e){_x000D_
     _x000D_
       if($(window.getSelection().anchorNode).is($(this))){_x000D_
       $('#position').html('0')_x000D_
       }else{_x000D_
         $('#position').html(window.getSelection().anchorOffset);_x000D_
       }_x000D_
 });
_x000D_
body{_x000D_
  padding:40px;_x000D_
}_x000D_
#editable{_x000D_
  height:50px;_x000D_
  width:400px;_x000D_
  border:1px solid #000;_x000D_
}_x000D_
#editable p{_x000D_
  margin:0;_x000D_
  padding:0;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.1/jquery.min.js"></script>_x000D_
<div contenteditable="true" id="editable">move the cursor to see position</div>_x000D_
<div>_x000D_
position : <span id="position"></span>_x000D_
</div>
_x000D_
_x000D_
_x000D_

file_put_contents: Failed to open stream, no such file or directory

There is definitly a problem with the destination folder path.

Your above error message says, it wants to put the contents to a file in the directory /files/grantapps/, which would be beyond your vhost, but somewhere in the system (see the leading absolute slash )

You should double check:

  • Is the directory /home/username/public_html/files/grantapps/ really present.
  • Contains your loop and your file_put_contents-Statement the absolute path /home/username/public_html/files/grantapps/

Java read file and store text in an array

Stored as strings:

public class ReadTemps {

    public static void main(String[] args) throws IOException {
    // TODO code application logic here

    // // read KeyWestTemp.txt

    // create token1
    String token1 = "";

    // for-each loop for calculating heat index of May - October

    // create Scanner inFile1
    Scanner inFile1 = new Scanner(new File("KeyWestTemp.txt")).useDelimiter(",\\s*");

    // Original answer used LinkedList, but probably preferable to use ArrayList in most cases
    // List<String> temps = new LinkedList<String>();
    List<String> temps = new ArrayList<String>();

    // while loop
    while (inFile1.hasNext()) {
      // find next line
      token1 = inFile1.next();
      temps.add(token1);
    }
    inFile1.close();

    String[] tempsArray = temps.toArray(new String[0]);

    for (String s : tempsArray) {
      System.out.println(s);
    }
  }
}

For floats:

import java.io.File;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;

public class ReadTemps {

  public static void main(String[] args) throws IOException {
    // TODO code application logic here

    // // read KeyWestTemp.txt

    // create token1

    // for-each loop for calculating heat index of May - October

    // create Scanner inFile1
    Scanner inFile1 = new Scanner(new File("KeyWestTemp.txt")).useDelimiter(",\\s*");


    // Original answer used LinkedList, but probably preferable to use ArrayList in most cases
    // List<Float> temps = new LinkedList<Float>();
    List<Float> temps = new ArrayList<Float>();

    // while loop
    while (inFile1.hasNext()) {
      // find next line
      float token1 = inFile1.nextFloat();
      temps.add(token1);
    }
    inFile1.close();

    Float[] tempsArray = temps.toArray(new Float[0]);

    for (Float s : tempsArray) {
      System.out.println(s);
    }
  }
}

regex string replace

Just change + to -:

str = str.replace(/[^a-z0-9-]/g, "");

You can read it as:

  1. [^ ]: match NOT from the set
  2. [^a-z0-9-]: match if not a-z, 0-9 or -
  3. / /g: do global match

More information:

correct way to use super (argument passing)

If you're going to have a lot of inheritence (that's the case here) I suggest you to pass all parameters using **kwargs, and then pop them right after you use them (unless you need them in upper classes).

class First(object):
    def __init__(self, *args, **kwargs):
        self.first_arg = kwargs.pop('first_arg')
        super(First, self).__init__(*args, **kwargs)

class Second(First):
    def __init__(self, *args, **kwargs):
        self.second_arg = kwargs.pop('second_arg')
        super(Second, self).__init__(*args, **kwargs)

class Third(Second):
    def __init__(self, *args, **kwargs):
        self.third_arg = kwargs.pop('third_arg')
        super(Third, self).__init__(*args, **kwargs)

This is the simplest way to solve those kind of problems.

third = Third(first_arg=1, second_arg=2, third_arg=3)

How do you find the row count for all your tables in Postgres

I usually don't rely on statistics, especially in PostgreSQL.

SELECT table_name, dsql2('select count(*) from '||table_name) as rownum
FROM information_schema.tables
WHERE table_type='BASE TABLE'
    AND table_schema='livescreen'
ORDER BY 2 DESC;
CREATE OR REPLACE FUNCTION dsql2(i_text text)
  RETURNS int AS
$BODY$
Declare
  v_val int;
BEGIN
  execute i_text into v_val;
  return v_val;
END; 
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;

How to tell a Mockito mock object to return something different the next time it is called?

For Anyone using spy() and the doReturn() instead of the when() method:

what you need to return different object on different calls is this:

doReturn(obj1).doReturn(obj2).when(this.spyFoo).someMethod();

.

For classic mocks:

when(this.mockFoo.someMethod()).thenReturn(obj1, obj2);

or with an exception being thrown:

when(mockFoo.someMethod())
        .thenReturn(obj1)
        .thenThrow(new IllegalArgumentException())
        .thenReturn(obj2, obj3);

What does mscorlib stand for?

It stands for

Microsoft's Common Object Runtime Library

and it is the primary assembly for the Framework Common Library.

It contains the following namespaces:

 System
 System.Collections
 System.Configuration.Assemblies
 System.Diagnostics
 System.Diagnostics.SymbolStore
 System.Globalization
 System.IO
 System.IO.IsolatedStorage
 System.Reflection
 System.Reflection.Emit
 System.Resources
 System.Runtime.CompilerServices
 System.Runtime.InteropServices
 System.Runtime.InteropServices.Expando
 System.Runtime.Remoting
 System.Runtime.Remoting.Activation
 System.Runtime.Remoting.Channels
 System.Runtime.Remoting.Contexts
 System.Runtime.Remoting.Lifetime
 System.Runtime.Remoting.Messaging
 System.Runtime.Remoting.Metadata
 System.Runtime.Remoting.Metadata.W3cXsd2001
 System.Runtime.Remoting.Proxies
 System.Runtime.Remoting.Services
 System.Runtime.Serialization
 System.Runtime.Serialization.Formatters
 System.Runtime.Serialization.Formatters.Binary
 System.Security
 System.Security.Cryptography
 System.Security.Cryptography.X509Certificates
 System.Security.Permissions
 System.Security.Policy
 System.Security.Principal
 System.Text
 System.Threading
 Microsoft.Win32 

Interesting info about MSCorlib:

  • The .NET 2.0 assembly will reference and use the 2.0 mscorlib.The .NET 1.1 assembly will reference the 1.1 mscorlib but will use the 2.0 mscorlib at runtime (due to hard-coded version redirects in theruntime itself)
  • In GAC there is only one version of mscorlib, you dont find 1.1 version on GAC even if you have 1.1 framework installed on your machine. It would be good if somebody can explain why MSCorlib 2.0 alone is in GAC whereas 1.x version live inside framework folder
  • Is it possible to force a different runtime to be loaded by the application by making a config setting in your app / web.config? you won’t be able to choose the CLR version by settings in the ConfigurationFile – at that point, a CLR will already be running, and there can only be one per process. Immediately after the CLR is chosen the MSCorlib appropriate for that CLR is loaded.

Calculate percentage Javascript

Try:

const result = Math.round((data.expense / data.income) * 100)

What does "&" at the end of a linux command mean?

The & makes the command run in the background.

From man bash:

If a command is terminated by the control operator &, the shell executes the command in the background in a subshell. The shell does not wait for the command to finish, and the return status is 0.

How to download the latest artifact from Artifactory repository?

In case you need to download an artifact in a Dockerfile, instead of using wget or curl or the likes you can simply use the 'ADD' directive:

ADD ${ARTIFACT_URL} /opt/app/app.jar

Of course, the tricky part is determining the ARTIFACT_URL, but there's enough about that in all the other answers.

However, Docker best practises strongly discourage using ADD for this purpose and recommend using wget or curl.

Difference between npx and npm?

Here's an example of NPX in action: npx cowsay hello

If you type that into your bash terminal you'll see the result. The benefit of this is that npx has temporarily installed cowsay. There is no package pollution since cowsay is not permanently installed. This is great for one off packages where you want to avoid package pollution.

As mentioned in other answers, npx is also very useful in cases where (with npm) the package needs to be installed then configured before running. E.g. instead of using npm to install and then configure the json.package file and then call the configured run command just use npx instead. A real example: npx create-react-app my-app

Unable to compile class for JSP

Try adding this to your web.xml:

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>
        /WEB-INF/your-servlet-name.xml
    </param-value>

Java Currency Number format

I think this is simple and clear for printing a currency:

DecimalFormat df = new DecimalFormat("$###,###.##"); // or pattern "###,###.##$"
System.out.println(df.format(12345.678));

output: $12,345.68

And one of possible solutions for the question:

public static void twoDecimalsOrOmit(double d) {
    System.out.println(new DecimalFormat(d%1 == 0 ? "###.##" : "###.00").format(d));
}

twoDecimalsOrOmit((double) 100);
twoDecimalsOrOmit(100.1);

Output:

100

100.10

AngularJS - get element attributes values

Use Jquery functions

<Button id="myPselector" data-id="1234">HI</Button> 
console.log($("#myPselector").attr('data-id'));

dispatch_after - GCD in Swift?

Swift 3+

This is super-easy and elegant in Swift 3+:

DispatchQueue.main.asyncAfter(deadline: .now() + 4.5) {
    // ...
}

Older Answer:

To expand on Cezary's answer, which will execute after 1 nanosecond, I had to do the following to execute after 4 and a half seconds.

let delay = 4.5 * Double(NSEC_PER_SEC)
let time = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))
dispatch_after(time, dispatch_get_main_queue(), block)

Edit: I discovered that my original code was slightly wrong. Implicit typing causes a compile error if you don't cast NSEC_PER_SEC to a Double.

If anyone can suggest a more optimal solution I'd be keen to hear it.

Detect touch press vs long press vs movement?

I was looking for a similar solution and this is what I would suggest. In the OnTouch method, record the time for MotionEvent.ACTION_DOWN event and then for MotionEvent.ACTION_UP, record the time again. This way you can set your own threshold also. After experimenting few times you will know the max time in millis it would need to record a simple touch and you can use this in move or other method as you like.

Hope this helped. Please comment if you used a different method and solved your problem.

What is the 'open' keyword in Swift?

Open is an access level, was introduced to impose limitations on class inheritance on Swift.

This means that the open access level can only be applied to classes and class members.

In Classes

An open class can be subclassed in the module it is defined in and in modules that import the module in which the class is defined.

In Class members

The same applies to class members. An open method can be overridden by subclasses in the module it is defined in and in modules that import the module in which the method is defined.

THE NEED FOR THIS UPDATE

Some classes of libraries and frameworks are not designed to be subclassed and doing so may result in unexpected behavior. Native Apple library also won't allow overriding the same methods and classes,

So after this addition they will apply public and private access levels accordingly.

For more details have look at Apple Documentation on Access Control

Scroll event listener javascript

For those who found this question hoping to find an answer that doesn't involve jQuery, you hook into the window "scroll" event using normal event listening. Say we want to add scroll listening to a number of CSS-selector-able elements:

// what should we do when scrolling occurs
var runOnScroll =  function(evt) {
  // not the most exciting thing, but a thing nonetheless
  console.log(evt.target);
};

// grab elements as array, rather than as NodeList
var elements = document.querySelectorAll("...");
elements = Array.prototype.slice.call(elements);

// and then make each element do something on scroll
elements.forEach(function(element) {
  window.addEventListener("scroll", runOnScroll, {passive: true});
});

(Using the passive attribute to tell the browser that this event won't interfere with scrolling itself)

For bonus points, you can give the scroll handler a lock mechanism so that it doesn't run if we're already scrolling:

// global lock, so put this code in a closure of some sort so you're not polluting.
var locked = false;
var lastCall = false;

var runOnScroll =  function(evt) {
  if(locked) return;

  if (lastCall) clearTimeout(lastCall);
  lastCall = setTimeout(() => {
    runOnScroll(evt);
    // you do this because you want to handle the last
    // scroll event, even if it occurred while another
    // event was being processed.
  }, 200);

  // ...your code goes here...

  locked = false;
};

How do I reset the scale/zoom of a web app on an orientation change on the iPhone?

I had the same problem, and setting the maximum-scale=1.0 worked for me.

Edit: As mentioned in the comments this does disable user zoom except when the content exceeds the width-resolution. As mentioned, this might not be wise. It might also be desired in some cases.

The viewport code:

    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0;">

Change navbar color in Twitter Bootstrap

Using Less

You could also consider to compile your own version. Try http://getbootstrap.com/customize/ (which has a apart section for the Navbars settings (Default navbar and Inverted Navbar)) or download your own copy from https://github.com/twbs/bootstrap.

You will find the navbar settings in variables.less. navbar.less is used to compile the navbar (depends on variables.less and mixins.less).

Copy the 'navbar-default section' and fill in your own color settings. Changing the variables in variables.less will be the easiest way (changing the default or inverse navbar won't be a problem because you have one navbar per page only).

You won't change all settings in most cases:

// Navbar
// -------------------------

// Basics of a navbar
@navbar-height:                    50px;
@navbar-margin-bottom:             @line-height-computed;
@navbar-default-color:             #777;
@navbar-default-bg:                #f8f8f8;
@navbar-default-border:            darken(@navbar-default-bg, 6.5%);
@navbar-border-radius:             @border-radius-base;
@navbar-padding-horizontal:        floor(@grid-gutter-width / 2);
@navbar-padding-vertical:          ((@navbar-height - @line-height-computed) / 2);

// Navbar links
@navbar-default-link-color:                #777;
@navbar-default-link-hover-color:          #333;
@navbar-default-link-hover-bg:             transparent;
@navbar-default-link-active-color:         #555;
@navbar-default-link-active-bg:            darken(@navbar-default-bg, 6.5%);
@navbar-default-link-disabled-color:       #ccc;
@navbar-default-link-disabled-bg:          transparent;

// Navbar brand label
@navbar-default-brand-color:               @navbar-default-link-color;
@navbar-default-brand-hover-color:         darken(@navbar-default-link-color, 10%);
@navbar-default-brand-hover-bg:            transparent;

// Navbar toggle
@navbar-default-toggle-hover-bg:           #ddd;
@navbar-default-toggle-icon-bar-bg:        #ccc;
@navbar-default-toggle-border-color:       #ddd;

You could also try http://twitterbootstrap3navbars.w3masters.nl/. This tool generates CSS code for your custom navbar. Optionally, you could also add gradient colors and borders to the navbar.

What regular expression will match valid international phone numbers?

All country codes are defined by the ITU. The following regex is based on ITU-T E.164 and Annex to ITU Operational Bulletin No. 930 – 15.IV.2009. It contains all current country codes and codes reserved for future use. While it could be shortened a bit, I decided to include each code independently.

This is for calls originating from the USA. For other countries, replace the international access code (the 011 at the beginning of the regex) with whatever is appropriate for that country's dialing plan.

Also, note that ITU E.164 defines the maximum length of a full international telephone number to 15 digits. This means a three digit country code results in up to 12 additional digits, and a 1 digit country code could contain up to 14 additional digits. Hence the

[0-9]{0,14}$

a the end of the regex.

Most importantly, this regex does not mean the number is valid - each country defines its own internal numbering plan. This only ensures that the country code is valid.

^011(999|998|997|996|995|994|993|992|991| 990|979|978|977|976|975|974|973|972|971|970| 969|968|967|966|965|964|963|962|961|960|899| 898|897|896|895|894|893|892|891|890|889|888| 887|886|885|884|883|882|881|880|879|878|877| 876|875|874|873|872|871|870|859|858|857|856| 855|854|853|852|851|850|839|838|837|836|835| 834|833|832|831|830|809|808|807|806|805|804| 803|802|801|800|699|698|697|696|695|694|693| 692|691|690|689|688|687|686|685|684|683|682| 681|680|679|678|677|676|675|674|673|672|671| 670|599|598|597|596|595|594|593|592|591|590| 509|508|507|506|505|504|503|502|501|500|429| 428|427|426|425|424|423|422|421|420|389|388| 387|386|385|384|383|382|381|380|379|378|377| 376|375|374|373|372|371|370|359|358|357|356| 355|354|353|352|351|350|299|298|297|296|295| 294|293|292|291|290|289|288|287|286|285|284| 283|282|281|280|269|268|267|266|265|264|263| 262|261|260|259|258|257|256|255|254|253|252| 251|250|249|248|247|246|245|244|243|242|241| 240|239|238|237|236|235|234|233|232|231|230| 229|228|227|226|225|224|223|222|221|220|219| 218|217|216|215|214|213|212|211|210|98|95|94| 93|92|91|90|86|84|82|81|66|65|64|63|62|61|60| 58|57|56|55|54|53|52|51|49|48|47|46|45|44|43| 41|40|39|36|34|33|32|31|30|27|20|7|1)[0-9]{0, 14}$

How to restore a SQL Server 2012 database to SQL Server 2008 R2?

To: Killercam Thanks for your solutions. I tried the first solution for an hour, but didn't work for me.

I used scripts generate method to move data from SQL Server 2012 to SQL Server 2008 R2 as steps bellow:

In the 2012 SQL Management Studio

  1. Tasks -> Generate Scripts (in first wizard screen, click Next - may not show)
  2. Choose Script entire database and all database objects -> Next
  3. Click [Advanced] button 3.1 Change [Types of data to script] from "Schema only" to "Schema and data" 3.2 Change [Script for Server Version] "2012" to "2008"
  4. Finish next wizard steps for creating script file
  5. Use sqlcmd to import the exported script file to your SQL Server 2008 R2 5.1 Open windows command line 5.2 Type [sqlcmd -S -i Path to your file] (Ex: [sqlcmd -S localhost -i C:\mydatabase.sql])

It works for me.

What does "to stub" mean in programming?

Stub is a piece of code which converts the parameters during RPC (Remote procedure call).The parameters of RPC have to be converted because both client and server use different address space. Stub performs this conversion so that server perceive the RPC as a local function call.

How do I POST JSON data with cURL?

Here is another way to do it, if you have dynamic data to be included.

#!/bin/bash

version=$1
text=$2
branch=$(git rev-parse --abbrev-ref HEAD)
repo_full_name=$(git config --get remote.origin.url | sed 's/.*:\/\/github.com\///;s/.git$//')
token=$(git config --global github.token)

generate_post_data()
{
  cat <<EOF
{
  "tag_name": "$version",
  "target_commitish": "$branch",
  "name": "$version",
  "body": "$text",
  "draft": false,
  "prerelease": false
}
EOF
}

echo "Create release $version for repo: $repo_full_name branch: $branch"
curl --data "$(generate_post_data)" "https://api.github.com/repos/$repo_full_name/releases?access_token=$token"

Python import csv to list

You can use the list() function to convert csv reader object to list

import csv

with open('input.csv') as csv_file:
    reader = csv.reader(csv_file, delimiter=',')
    rows = list(reader)
    print(rows)

Checkbox value true/false

jQuery.is() function does not have a signature for .is('selector', function).

I guess you want to do something like this:

      if($("#checkbox1").is(':checked')){
          $("#checkbox1").attr('value', 'true');
      }

How to plot vectors in python using matplotlib

What did you expect the following to do?

v1 = [0,0],[M[i,0],M[i,1]]
v1 = [M[i,0]],[M[i,1]]

This is making two different tuples, and you overwrite what you did the first time... Anyway, matplotlib does not understand what a "vector" is in the sense you are using. You have to be explicit, and plot "arrows":

In [5]: ax = plt.axes()

In [6]: ax.arrow(0, 0, *v1, head_width=0.05, head_length=0.1)
Out[6]: <matplotlib.patches.FancyArrow at 0x114fc8358>

In [7]: ax.arrow(0, 0, *v2, head_width=0.05, head_length=0.1)
Out[7]: <matplotlib.patches.FancyArrow at 0x115bb1470>

In [8]: plt.ylim(-5,5)
Out[8]: (-5, 5)

In [9]: plt.xlim(-5,5)
Out[9]: (-5, 5)

In [10]: plt.show()

Result:

enter image description here

Google Maps: How to create a custom InfoWindow?

I think the best answer I've come up with is here: https://codepen.io/sentrathis96/pen/yJPZGx

I can't take credit for this, I forked this from another codepen user to fix the google maps dependency to actually load

Make note of the call to:

InfoWindow() // constructor

Compare two Timestamp in java

Just convert the timestamp in millisec representation. Use getTime() method.

d3 add text to circle

Here is an example showing some text in circles with data from a json file: http://bl.ocks.org/4474971. Which gives the following:

enter image description here

The main idea behind this is to encapsulate the text and the circle in the same "div" as you would do in html to have the logo and the name of the company in the same div in a page header.

The main code is:

var width = 960,
    height = 500;

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height)

d3.json("data.json", function(json) {
    /* Define the data for the circles */
    var elem = svg.selectAll("g")
        .data(json.nodes)

    /*Create and place the "blocks" containing the circle and the text */  
    var elemEnter = elem.enter()
        .append("g")
        .attr("transform", function(d){return "translate("+d.x+",80)"})

    /*Create the circle for each block */
    var circle = elemEnter.append("circle")
        .attr("r", function(d){return d.r} )
        .attr("stroke","black")
        .attr("fill", "white")

    /* Create the text for each block */
    elemEnter.append("text")
        .attr("dx", function(d){return -20})
        .text(function(d){return d.label})
})

and the json file is:

{"nodes":[
  {"x":80, "r":40, "label":"Node 1"}, 
  {"x":200, "r":60, "label":"Node 2"}, 
  {"x":380, "r":80, "label":"Node 3"}
]}

The resulting html code shows the encapsulation you want:

<svg width="960" height="500">
    <g transform="translate(80,80)">
        <circle r="40" stroke="black" fill="white"></circle>
        <text dx="-20">Node 1</text>
    </g>
    <g transform="translate(200,80)">
        <circle r="60" stroke="black" fill="white"></circle>
        <text dx="-20">Node 2</text>
    </g>
    <g transform="translate(380,80)">
        <circle r="80" stroke="black" fill="white"></circle>
        <text dx="-20">Node 3</text>
    </g>
</svg>

How to execute a shell script on a remote server using Ansible?

local_action runs the command on the local server, not on the servers you specify in hosts parameter.

Change your "Execute the script" task to

- name: Execute the script
  command: sh /home/test_user/test.sh

and it should do it.

You don't need to repeat sudo in the command line because you have defined it already in the playbook.

According to Ansible Intro to Playbooks user parameter was renamed to remote_user in Ansible 1.4 so you should change it, too

remote_user: test_user

So, the playbook will become:

---
- name: Transfer and execute a script.
  hosts: server
  remote_user: test_user
  sudo: yes
  tasks:
     - name: Transfer the script
       copy: src=test.sh dest=/home/test_user mode=0777

     - name: Execute the script
       command: sh /home/test_user/test.sh

Get custom product attributes in Woocommerce

Update for 2018. You can use:

global $product;
echo wc_display_product_attributes( $product );

To customise the output, copy plugins/woocommerce/templates/single-product/product-attributes.php to themes/theme-child/woocommerce/single-product/product-attributes.php and modify that.

What is the iPhone 4 user-agent?

This site seems to keep a complete list that's still maintained

iPhone, iPod Touch, and iPad from iOS 2.0 - 5.1.1 (to date).

You do need to assemble the full user-agent string out of the information listed in the page's columns.

Python: How to use RegEx in an if statement?

Regex's shouldn't really be used in this fashion - unless you want something more complicated than what you're trying to do - for instance, you could just normalise your content string and comparision string to be:

if 'facebook.com' in content.lower():
    shutil.copy(x, "C:/Users/David/Desktop/Test/MyFiles2")

How do I center list items inside a UL element?

I overcame the problem with this solution.

HTML:

<div class="list-wrapper">
    <ul>
        <li>a</li>
        <li>b</li>
        <li>c</li>
        <li>d</li>
        <li>e</li>
    </ul>
</div>

CSS:

.list-wrapper {
   text-align: -webkit-center;
}
.list-wrapper ul {
    display:block;
}   

What is the difference between React Native and React?

React Js is manipulating with HTML Dom. But React native is manipulating with mobile(iOS/android) native ui component.

IndentationError expected an indented block

I got the same error, This is what i did to solve the issue.

Before Indentation:

enter image description here

Indentation Error: expected an indented block.

After Indentation:

enter image description here

Working fine. After TAB space.

How can I show/hide a specific alert with twitter bootstrap?

I use this alert

_x000D_
_x000D_
function myFunction() {_x000D_
   $('#passwordsNoMatchRegister').fadeIn(1000);_x000D_
   setTimeout(function() { _x000D_
       $('#passwordsNoMatchRegister').fadeOut(1000); _x000D_
   }, 5000);_x000D_
}
_x000D_
<link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">_x000D_
  <script src="//ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
  <script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>_x000D_
_x000D_
_x000D_
<button onclick="myFunction()">Try it</button> _x000D_
_x000D_
_x000D_
<div class="alert alert-danger" id="passwordsNoMatchRegister" style="display:none;">_x000D_
    <strong>Error!</strong> Looks like the passwords you entered don't match!_x000D_
  </div>_x000D_
  _x000D_
 _x000D_
  
_x000D_
_x000D_
_x000D_

How do I install TensorFlow's tensorboard?

The pip package you are looking for is tensorflow-tensorboard developed by Google.

scikit-learn random state in splitting dataset

If you don't mention the random_state in the code, then whenever you execute your code a new random value is generated and the train and test datasets would have different values each time.

However, if you use a particular value for random_state(random_state = 1 or any other value) everytime the result will be same,i.e, same values in train and test datasets.

How to view the Folder and Files in GAC?

I'm a day late and a dollar short on this one. If you want to view the folder structure of the GAC in Windows Explorer, you can do this by using the registry:

  1. Launch regedit.
  2. Navigate to HKLM\Software\Microsoft\Fusion
  3. Add a DWORD called DisableCacheViewer and set the value to 1.

For a temporary view, you can substitute a drive for the folder path, which strips away the special directory properties.

  1. Launch a Command Prompt at your account's privilege level.
  2. Type SUBST Z: C:\Windows\assembly
    • Z can be any free drive letter.
  3. Open My Computer and look in the new substitute directory.
  4. To remove the virtual drive from Command Prompt, type SUBST Z: /D

As for why you'd want to do something like this, I've used this trick to compare GAC'd DLLs between different machines to make sure they're truly the same.

while installing vc_redist.x64.exe, getting error "Failed to configure per-machine MSU package."

Posting answer to my own question as I found it here and was hidden in bottom somewhere -

https://social.msdn.microsoft.com/Forums/vstudio/en-US/64baed8c-b00c-40d5-b19a-99b26a11516e/visual-c-redistributable-for-visual-studio-2015-rc-fails-on-windows-server-2012?forum=vssetup

This is because the OS failed to install the required update Windows8.1-KB2999226-x64.msu.

However, you can install it by extracting that update to a folder (e.g. XXXX), and execute following cmdlet. You can find the Windows8.1-KB2999226-x64.msu at below.

C:\ProgramData\Package Cache\469A82B09E217DDCF849181A586DF1C97C0C5C85\packages\Patch\amd64\Windows8.1-KB2999226-x64.msu

copy this file to a folder you like, and

Create a folder XXXX in that and execute following commands from Admin command propmt

wusa.exe Windows8.1-KB2999226-x64.msu /extract:XXXX

DISM.exe /Online /Add-Package /PackagePath:XXXX\Windows8.1-KB2999226-x64.cab

vc_redist.x64.exe /repair

(last command need not be run. Just execute vc_redist.x64.exe once again)

this worked for me.

How to debug (only) JavaScript in Visual Studio?

For debugging JavaScript code in VS2015, there is no need for

  1. Enabling script debugging in IE Options -> Advanced tab
  2. Writing debugger statement in JavaScript code

Attaching IE didn't work, but here is a workaround.

Select IE

enter image description here

and press F5. This will attach both worker process and IE as shown here- enter image description here

If you are not interested in debugging server code, detach it from Processes window. enter image description here

You will still face the slowness when you press F5 and all your server code compiles and loads up in VS. Note that you can detach and attach again the IE instance launched from VS. JavaScript breakpoints are hit the same way they are in server side code.

How to target the href to div

if you use

angularjs

you have just to write the right css in order to frame you div html code

<div 
style="height:51px;width:111px;margin-left:203px;" 
ng-click="nextDetail()">
</div>


JS Code(in your controller):

$scope.nextDetail = function()
{
....
}

How to set python variables to true or false?

First to answer your question, you set a variable to true or false by assigning True or False to it:

myFirstVar = True
myOtherVar = False

If you have a condition that is basically like this though:

if <condition>:
    var = True
else:
    var = False

then it is much easier to simply assign the result of the condition directly:

var = <condition>

In your case:

match_var = a == b

How can I send emails through SSL SMTP with the .NET Framework?

In VB.NET while trying to connect to Rackspace's SSL port on 465 I encountered the same issue (requires implicit SSL). I made use of https://www.nuget.org/packages/MailKit/ in order to successfully connect.

The following is an example of an HTML email message.

Imports MailKit.Net.Smtp
Imports MailKit
Imports MimeKit

Sub somesub()
    Dim builder As New BodyBuilder()
    Dim mail As MimeMessage
    mail = New MimeMessage()
    mail.From.Add(New MailboxAddress("", c_MailUser))
    mail.To.Add(New MailboxAddress("", c_ToUser))
    mail.Subject = "Mail Subject"
    builder.HtmlBody = "<html><body>Body Text"
    builder.HtmlBody += "</body></html>"
      mail.Body = builder.ToMessageBody()

      Using client As New SmtpClient
        client.Connect(c_MailServer, 465, True)
        client.AuthenticationMechanisms.Remove("XOAUTH2") ' Do not use OAUTH2
        client.Authenticate(c_MailUser, c_MailPassword) ' Use a username / password to authenticate.
        client.Send(mail)
        client.Disconnect(True)
    End Using 

End Sub

How do I import the javax.servlet API in my Eclipse project?

From wikipedia.

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class HelloWorld extends HttpServlet {
  public void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    PrintWriter out = response.getWriter();
    out.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 " +
                "Transitional//EN\">\n" +
                "<html>\n" +
                "<head><title>Hello WWW</title></head>\n" +
                "<body>\n" +
                "<h1>Hello WWW</h1>\n" +
                "</body></html>");
  }
}

This, of course, works only if you have added the servlet-api.jar to Eclipse build path. Typically your application server (e.g Tomcat) will have the right jar file.

paint() and repaint() in Java

It's not necessary to call repaint unless you need to render something specific onto a component. "Something specific" meaning anything that isn't provided internally by the windowing toolkit you're using.

Static linking vs dynamic linking

Best example for dynamic linking is, when the library is dependent on the used hardware. In ancient times the C math library was decided to be dynamic, so that each platform can use all processor capabilities to optimize it.

An even better example might be OpenGL. OpenGl is an API that is implemented differently by AMD and NVidia. And you are not able to use an NVidia implementation on an AMD card, because the hardware is different. You cannot link OpenGL statically into your program, because of that. Dynamic linking is used here to let the API be optimized for all platforms.

join list of lists in python

A performance comparison:

import itertools
import timeit
big_list = [[0]*1000 for i in range(1000)]
timeit.repeat(lambda: list(itertools.chain.from_iterable(big_list)), number=100)
timeit.repeat(lambda: list(itertools.chain(*big_list)), number=100)
timeit.repeat(lambda: (lambda b: map(b.extend, big_list))([]), number=100)
timeit.repeat(lambda: [el for list_ in big_list for el in list_], number=100)
[100*x for x in timeit.repeat(lambda: sum(big_list, []), number=1)]

Producing:

>>> import itertools
>>> import timeit
>>> big_list = [[0]*1000 for i in range(1000)]
>>> timeit.repeat(lambda: list(itertools.chain.from_iterable(big_list)), number=100)
[3.016212113769325, 3.0148865239060227, 3.0126415732791028]
>>> timeit.repeat(lambda: list(itertools.chain(*big_list)), number=100)
[3.019953987082083, 3.528754223385439, 3.02181439266457]
>>> timeit.repeat(lambda: (lambda b: map(b.extend, big_list))([]), number=100)
[1.812084445152557, 1.7702404451095965, 1.7722977998725362]
>>> timeit.repeat(lambda: [el for list_ in big_list for el in list_], number=100)
[5.409658160700605, 5.477502077679354, 5.444318360412744]
>>> [100*x for x in timeit.repeat(lambda: sum(big_list, []), number=1)]
[399.27587954973444, 400.9240571138051, 403.7521153804846]

This is with Python 2.7.1 on Windows XP 32-bit, but @temoto in the comments above got from_iterable to be faster than map+extend, so it's quite platform and input dependent.

Stay away from sum(big_list, [])

How to get the insert ID in JDBC?

In my case ->

ConnectionClass objConnectionClass=new ConnectionClass();
con=objConnectionClass.getDataBaseConnection();
pstmtGetAdd=con.prepareStatement(SQL_INSERT_ADDRESS_QUERY,Statement.RETURN_GENERATED_KEYS);
pstmtGetAdd.setString(1, objRegisterVO.getAddress());
pstmtGetAdd.setInt(2, Integer.parseInt(objRegisterVO.getCityId()));
int addId=pstmtGetAdd.executeUpdate();              
if(addId>0)
{
    ResultSet rsVal=pstmtGetAdd.getGeneratedKeys();
    rsVal.next();
    addId=rsVal.getInt(1);
}

How to turn a String into a JavaScript function call?

I prefer to use something like this:

window.callbackClass['newFunctionName'] = function(data) { console.log(data) };
...
window.callbackClass['newFunctionName'](data);

Click a button programmatically - JS

The other answers here rely on the user making an initial click (on the image). This is fine for the specifics of the OP detail but not necessarily the question title.

There is an answer here explaining how to do it by firing a click event on the button ( or any element ).

Splitting string into multiple rows in Oracle

There is a huge difference between the below two:

  • splitting a single delimited string
  • splitting delimited strings for multiple rows in a table.

If you do not restrict the rows, then the CONNECT BY clause would produce multiple rows and will not give the desired output.

Apart from Regular Expressions, a few other alternatives are using:

  • XMLTable
  • MODEL clause

Setup

SQL> CREATE TABLE t (
  2    ID          NUMBER GENERATED ALWAYS AS IDENTITY,
  3    text        VARCHAR2(100)
  4  );

Table created.

SQL>
SQL> INSERT INTO t (text) VALUES ('word1, word2, word3');

1 row created.

SQL> INSERT INTO t (text) VALUES ('word4, word5, word6');

1 row created.

SQL> INSERT INTO t (text) VALUES ('word7, word8, word9');

1 row created.

SQL> COMMIT;

Commit complete.

SQL>
SQL> SELECT * FROM t;

        ID TEXT
---------- ----------------------------------------------
         1 word1, word2, word3
         2 word4, word5, word6
         3 word7, word8, word9

SQL>

Using XMLTABLE:

SQL> SELECT id,
  2         trim(COLUMN_VALUE) text
  3  FROM t,
  4    xmltable(('"'
  5    || REPLACE(text, ',', '","')
  6    || '"'))
  7  /

        ID TEXT
---------- ------------------------
         1 word1
         1 word2
         1 word3
         2 word4
         2 word5
         2 word6
         3 word7
         3 word8
         3 word9

9 rows selected.

SQL>

Using MODEL clause:

SQL> WITH
  2  model_param AS
  3     (
  4            SELECT id,
  5                      text AS orig_str ,
  6                   ','
  7                          || text
  8                          || ','                                 AS mod_str ,
  9                   1                                             AS start_pos ,
 10                   Length(text)                                   AS end_pos ,
 11                   (Length(text) - Length(Replace(text, ','))) + 1 AS element_count ,
 12                   0                                             AS element_no ,
 13                   ROWNUM                                        AS rn
 14            FROM   t )
 15     SELECT   id,
 16              trim(Substr(mod_str, start_pos, end_pos-start_pos)) text
 17     FROM     (
 18                     SELECT *
 19                     FROM   model_param MODEL PARTITION BY (id, rn, orig_str, mod_str)
 20                     DIMENSION BY (element_no)
 21                     MEASURES (start_pos, end_pos, element_count)
 22                     RULES ITERATE (2000)
 23                     UNTIL (ITERATION_NUMBER+1 = element_count[0])
 24                     ( start_pos[ITERATION_NUMBER+1] = instr(cv(mod_str), ',', 1, cv(element_no)) + 1,
 25                     end_pos[iteration_number+1] = instr(cv(mod_str), ',', 1, cv(element_no) + 1) )
 26                 )
 27     WHERE    element_no != 0
 28     ORDER BY mod_str ,
 29           element_no
 30  /

        ID TEXT
---------- --------------------------------------------------
         1 word1
         1 word2
         1 word3
         2 word4
         2 word5
         2 word6
         3 word7
         3 word8
         3 word9

9 rows selected.

SQL>

Could not connect to SMTP host: smtp.gmail.com, port: 465, response: -1

You need to tell it that you are using SSL:

props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");

In case you miss anything, here is working code:

String  d_email = "[email protected]",
            d_uname = "Name",
            d_password = "urpassword",
            d_host = "smtp.gmail.com",
            d_port  = "465",
            m_to = "[email protected]",
            m_subject = "Indoors Readable File: " + params[0].getName(),
            m_text = "This message is from Indoor Positioning App. Required file(s) are attached.";
    Properties props = new Properties();
    props.put("mail.smtp.user", d_email);
    props.put("mail.smtp.host", d_host);
    props.put("mail.smtp.port", d_port);
    props.put("mail.smtp.starttls.enable","true");
    props.put("mail.smtp.debug", "true");
    props.put("mail.smtp.auth", "true");
    props.put("mail.smtp.socketFactory.port", d_port);
    props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
    props.put("mail.smtp.socketFactory.fallback", "false");

    SMTPAuthenticator auth = new SMTPAuthenticator();
    Session session = Session.getInstance(props, auth);
    session.setDebug(true);

    MimeMessage msg = new MimeMessage(session);
    try {
        msg.setSubject(m_subject);
        msg.setFrom(new InternetAddress(d_email));
        msg.addRecipient(Message.RecipientType.TO, new InternetAddress(m_to));

Transport transport = session.getTransport("smtps");
            transport.connect(d_host, Integer.valueOf(d_port), d_uname, d_password);
            transport.sendMessage(msg, msg.getAllRecipients());
            transport.close();

        } catch (AddressException e) {
            e.printStackTrace();
            return false;
        } catch (MessagingException e) {
            e.printStackTrace();
            return false;
        }

Remove char at specific index - python

Try this code:

s = input() 
a = int(input()) 
b = s.replace(s[a],'')
print(b)

Map implementation with duplicate keys

class  DuplicateMap<K, V> 
{
    enum MapType
    {
        Hash,LinkedHash
    }

    int HashCode = 0;
    Map<Key<K>,V> map = null;

    DuplicateMap()
    {
        map = new HashMap<Key<K>,V>();
    }

    DuplicateMap( MapType maptype )
    {
        if ( maptype == MapType.Hash ) {
            map = new HashMap<Key<K>,V>();
        }
        else if ( maptype == MapType.LinkedHash ) {
            map = new LinkedHashMap<Key<K>,V>();
        }
        else
            map = new HashMap<Key<K>,V>();
    }

    V put( K key, V value  )
    {

        return map.put( new Key<K>( key , HashCode++ ), value );
    }

    void putAll( Map<K, V> map1 )
    {
        Map<Key<K>,V> map2 = new LinkedHashMap<Key<K>,V>();

        for ( Entry<K, V> entry : map1.entrySet() ) {
            map2.put( new Key<K>( entry.getKey() , HashCode++ ), entry.getValue());
        }
        map.putAll(map2);
    }

    Set<Entry<K, V>> entrySet()
    {
        Set<Entry<K, V>> entry = new LinkedHashSet<Map.Entry<K,V>>();
        for ( final Entry<Key<K>, V> entry1 : map.entrySet() ) {
            entry.add( new Entry<K, V>(){
                private K Key = entry1.getKey().Key();
                private V Value = entry1.getValue();

                @Override
                public K getKey() {
                    return Key;
                }

                @Override
                public V getValue() {
                    return Value;
                }

                @Override
                public V setValue(V value) {
                    return null;
                }});
        }

        return entry;
    }

    @Override
    public String toString() {
        StringBuilder builder = new  StringBuilder();
        builder.append("{");
        boolean FirstIteration = true;
        for ( Entry<K, V> entry : entrySet() ) {
            builder.append( ( (FirstIteration)? "" : "," ) + ((entry.getKey()==null) ? null :entry.getKey().toString() ) + "=" + ((entry.getValue()==null) ? null :entry.getValue().toString() )  );
            FirstIteration = false;
        }
        builder.append("}");
        return builder.toString();
    }

    class Key<K1>
    {
        K1 Key;
        int HashCode;

        public Key(K1 key, int hashCode) {
            super();
            Key = key;
            HashCode = hashCode;
        }

        public K1 Key() {
            return Key;
        }

        @Override
        public String toString() {
            return  Key.toString() ;
        }

        @Override
        public int hashCode() {

            return HashCode;
        }
    }

How to change JAVA.HOME for Eclipse/ANT

Also be sure to set your JAVA_HOME environment variable. In fact, I usually set the JAVA_HOME, then prepend the string "%JAVA_HOME%\bin" to the system's PATH environment variable so that if Java ever gets upgraded or changed, only the JAVA_HOME variable will need to be changed.

And make sure that you close any command prompt windows or open applications that may read your environment variables, as changes to environment variables are normally not noticed until an application is re-launched.

What are MVP and MVC and what is the difference?

Also worth remembering is that there are different types of MVPs as well. Fowler has broken the pattern into two - Passive View and Supervising Controller.

When using Passive View, your View typically implement a fine-grained interface with properties mapping more or less directly to the underlaying UI widget. For instance, you might have a ICustomerView with properties like Name and Address.

Your implementation might look something like this:

public class CustomerView : ICustomerView
{
    public string Name
    { 
        get { return txtName.Text; }
        set { txtName.Text = value; }
    }
}

Your Presenter class will talk to the model and "map" it to the view. This approach is called the "Passive View". The benefit is that the view is easy to test, and it is easier to move between UI platforms (Web, Windows/XAML, etc.). The disadvantage is that you can't leverage things like databinding (which is really powerful in frameworks like WPF and Silverlight).

The second flavor of MVP is the Supervising Controller. In that case your View might have a property called Customer, which then again is databound to the UI widgets. You don't have to think about synchronizing and micro-manage the view, and the Supervising Controller can step in and help when needed, for instance with compled interaction logic.

The third "flavor" of MVP (or someone would perhaps call it a separate pattern) is the Presentation Model (or sometimes referred to Model-View-ViewModel). Compared to the MVP you "merge" the M and the P into one class. You have your customer object which your UI widgets is data bound to, but you also have additional UI-spesific fields like "IsButtonEnabled", or "IsReadOnly", etc.

I think the best resource I've found to UI architecture is the series of blog posts done by Jeremy Miller over at The Build Your Own CAB Series Table of Contents. He covered all the flavors of MVP and showed C# code to implement them.

I have also blogged about the Model-View-ViewModel pattern in the context of Silverlight over at YouCard Re-visited: Implementing the ViewModel pattern.

How to wait 5 seconds with jQuery?

Have been using this one for a message overlay that can be closed immediately on click or it does an autoclose after 10 seconds.

button = $('.status-button a', whatever);
if(button.hasClass('close')) {
  button.delay(10000).queue(function() {
    $(this).click().dequeue();
  });
}

Assign format of DateTime with data annotations?

set your property using below code at the time of model creation i think your problem will be solved..and the time are not appear in database.you dont need to add any annotation.

private DateTime? dob;
        public DateTime? DOB
        {
            get
            {
                if (dob != null)
                {
                    return dob.Value.Date;
                }
                else
                {
                    return null;
                }

            }
            set { dob = value; }
        }

How to insert text at beginning of a multi-line selection in vi/Vim

  • Press Esc to enter 'command mode'
  • Use Ctrl+V to enter visual block mode
  • Move Up/Downto select the columns of text in the lines you want to comment.
  • Then hit Shift+i and type the text you want to insert.
  • Then hit Esc, wait 1 second and the inserted text will appear on every line.

For further information and reading, check out "Inserting text in multiple lines" in the Vim Tips Wiki.

Calculate relative time in C#

In PHP, I do it this way:

<?php
function timesince($original) {
    // array of time period chunks
    $chunks = array(
        array(60 * 60 * 24 * 365 , 'year'),
        array(60 * 60 * 24 * 30 , 'month'),
        array(60 * 60 * 24 * 7, 'week'),
        array(60 * 60 * 24 , 'day'),
        array(60 * 60 , 'hour'),
        array(60 , 'minute'),
    );

    $today = time(); /* Current unix time  */
    $since = $today - $original;

    if($since > 604800) {
    $print = date("M jS", $original);

    if($since > 31536000) {
        $print .= ", " . date("Y", $original);
    }

    return $print;
}

// $j saves performing the count function each time around the loop
for ($i = 0, $j = count($chunks); $i < $j; $i++) {

    $seconds = $chunks[$i][0];
    $name = $chunks[$i][1];

    // finding the biggest chunk (if the chunk fits, break)
    if (($count = floor($since / $seconds)) != 0) {
        break;
    }
}

$print = ($count == 1) ? '1 '.$name : "$count {$name}s";

return $print . " ago";

} ?>

How to get request url in a jQuery $.get/ajax request

I can't get it to work on $.get() because it has no complete event.

I suggest to use $.ajax() like this,

$.ajax({
    url: 'http://www.example.org',
    data: {'a':1,'b':2,'c':3},
    dataType: 'xml',
    complete : function(){
        alert(this.url)
    },
    success: function(xml){
    }
});

craz demo

Stopword removal with NLTK

There is an in-built stopword list in NLTK made up of 2,400 stopwords for 11 languages (Porter et al), see http://nltk.org/book/ch02.html

>>> from nltk import word_tokenize
>>> from nltk.corpus import stopwords
>>> stop = set(stopwords.words('english'))
>>> sentence = "this is a foo bar sentence"
>>> print([i for i in sentence.lower().split() if i not in stop])
['foo', 'bar', 'sentence']
>>> [i for i in word_tokenize(sentence.lower()) if i not in stop] 
['foo', 'bar', 'sentence']

I recommend looking at using tf-idf to remove stopwords, see Effects of Stemming on the term frequency?

Get Current date & time with [NSDate date]

NSLocale* currentLocale = [NSLocale currentLocale];
[[NSDate date] descriptionWithLocale:currentLocale];  

or use

NSDateFormatter *dateFormatter=[[NSDateFormatter alloc] init]; 
[dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
// or @"yyyy-MM-dd hh:mm:ss a" if you prefer the time with AM/PM 
NSLog(@"%@",[dateFormatter stringFromDate:[NSDate date]]);

how to get the base url in javascript

This is done simply by doing this variable.

var base_url = '<?php echo base_url();?>'

This will have base url now. And now make a javascript function that will use this variable

function base_url(string){
    return base_url + string;
}

And now this will always use the correct path.

var path    =   "assets/css/themes/" + color_ + ".css"
$('#style_color').attr("href", base_url(path) );

"ssl module in Python is not available" when installing package with pip3

On macos, configure python 3.8.1 with the command below will solve the problem, i think it would also work on Linux.

./configure --enable-optimizations --with-openssl=/usr/local/opt/[email protected]/

change the dir parameter based on your system.

Sorting an array of objects by property values

While it is a bit of an overkill for just sorting a single array, this prototype function allows to sort Javascript arrays by any key, in ascending or descending order, including nested keys, using dot syntax.

(function(){
    var keyPaths = [];

    var saveKeyPath = function(path) {
        keyPaths.push({
            sign: (path[0] === '+' || path[0] === '-')? parseInt(path.shift()+1) : 1,
            path: path
        });
    };

    var valueOf = function(object, path) {
        var ptr = object;
        for (var i=0,l=path.length; i<l; i++) ptr = ptr[path[i]];
        return ptr;
    };

    var comparer = function(a, b) {
        for (var i = 0, l = keyPaths.length; i < l; i++) {
            aVal = valueOf(a, keyPaths[i].path);
            bVal = valueOf(b, keyPaths[i].path);
            if (aVal > bVal) return keyPaths[i].sign;
            if (aVal < bVal) return -keyPaths[i].sign;
        }
        return 0;
    };

    Array.prototype.sortBy = function() {
        keyPaths = [];
        for (var i=0,l=arguments.length; i<l; i++) {
            switch (typeof(arguments[i])) {
                case "object": saveKeyPath(arguments[i]); break;
                case "string": saveKeyPath(arguments[i].match(/[+-]|[^.]+/g)); break;
            }
        }
        return this.sort(comparer);
    };    
})();

Usage:

var data = [
    { name: { first: 'Josh', last: 'Jones' }, age: 30 },
    { name: { first: 'Carlos', last: 'Jacques' }, age: 19 },
    { name: { first: 'Carlos', last: 'Dante' }, age: 23 },
    { name: { first: 'Tim', last: 'Marley' }, age: 9 },
    { name: { first: 'Courtney', last: 'Smith' }, age: 27 },
    { name: { first: 'Bob', last: 'Smith' }, age: 30 }
]

data.sortBy('age'); // "Tim Marley(9)", "Carlos Jacques(19)", "Carlos Dante(23)", "Courtney Smith(27)", "Josh Jones(30)", "Bob Smith(30)"

Sorting by nested properties with dot-syntax or array-syntax:

data.sortBy('name.first'); // "Bob Smith(30)", "Carlos Dante(23)", "Carlos Jacques(19)", "Courtney Smith(27)", "Josh Jones(30)", "Tim Marley(9)"
data.sortBy(['name', 'first']); // "Bob Smith(30)", "Carlos Dante(23)", "Carlos Jacques(19)", "Courtney Smith(27)", "Josh Jones(30)", "Tim Marley(9)"

Sorting by multiple keys:

data.sortBy('name.first', 'age'); // "Bob Smith(30)", "Carlos Jacques(19)", "Carlos Dante(23)", "Courtney Smith(27)", "Josh Jones(30)", "Tim Marley(9)"
data.sortBy('name.first', '-age'); // "Bob Smith(30)", "Carlos Dante(23)", "Carlos Jacques(19)", "Courtney Smith(27)", "Josh Jones(30)", "Tim Marley(9)"

You can fork the repo: https://github.com/eneko/Array.sortBy

How do I write a for loop in bash

From this site:

for i in $(seq 1 10);
do
    echo $i
done

Querying date field in MongoDB with Mongoose

{ "date" : "1000000" } in your Mongo doc seems suspect. Since it's a number, it should be { date : 1000000 }

It's probably a type mismatch. Try post.findOne({date: "1000000"}, callback) and if that works, you have a typing issue.

django - get() returned more than one topic

Don't :-

xyz = Blogs.objects.get(user_id=id)

Use:-

xyz = Blogs.objects.all().filter(user_id=id)

How to get Locale from its String representation in Java?

Option 1 :

org.apache.commons.lang3.LocaleUtils.toLocale("en_US")

Option 2 :

Locale.forLanguageTag("en-US")

Please note Option 1 is "underscore" between language and country , and Option 2 is "dash".

Concatenate multiple result rows of one column into one, group by another column

Simpler with the aggregate function string_agg() (Postgres 9.0 or later):

SELECT movie, string_agg(actor, ', ') AS actor_list
FROM   tbl
GROUP  BY 1;

The 1 in GROUP BY 1 is a positional reference and a shortcut for GROUP BY movie in this case.

string_agg() expects data type text as input. Other types need to be cast explicitly (actor::text) - unless an implicit cast to text is defined - which is the case for all other character types (varchar, character, "char"), and some other types.

As isapir commented, you can add an ORDER BY clause in the aggregate call to get a sorted list - should you need that. Like:

SELECT movie, string_agg(actor, ', ' ORDER BY actor) AS actor_list
FROM   tbl
GROUP  BY 1;

But it's typically faster to sort rows in a subquery. See:

How to extract custom header value in Web API message handler?

Try something like this:

IEnumerable<string> headerValues = request.Headers.GetValues("MyCustomID");
var id = headerValues.FirstOrDefault();

There's also a TryGetValues method on Headers you can use if you're not always guaranteed to have access to the header.

What does it mean when a PostgreSQL process is "idle in transaction"?

The PostgreSQL manual indicates that this means the transaction is open (inside BEGIN) and idle. It's most likely a user connected using the monitor who is thinking or typing. I have plenty of those on my system, too.

If you're using Slony for replication, however, the Slony-I FAQ suggests idle in transaction may mean that the network connection was terminated abruptly. Check out the discussion in that FAQ for more details.

Boto3 to download all files from a S3 Bucket

I have been running into this problem for a while and with all of the different forums I've been through I haven't see a full end-to-end snip-it of what works. So, I went ahead and took all the pieces (add some stuff on my own) and have created a full end-to-end S3 Downloader!

This will not only download files automatically but if the S3 files are in subdirectories, it will create them on the local storage. In my application's instance, I need to set permissions and owners so I have added that too (can be comment out if not needed).

This has been tested and works in a Docker environment (K8) but I have added the environmental variables in the script just in case you want to test/run it locally.

I hope this helps someone out in their quest of finding S3 Download automation. I also welcome any advice, info, etc. on how this can be better optimized if needed.

#!/usr/bin/python3
import gc
import logging
import os
import signal
import sys
import time
from datetime import datetime

import boto
from boto.exception import S3ResponseError
from pythonjsonlogger import jsonlogger

formatter = jsonlogger.JsonFormatter('%(message)%(levelname)%(name)%(asctime)%(filename)%(lineno)%(funcName)')

json_handler_out = logging.StreamHandler()
json_handler_out.setFormatter(formatter)

#Manual Testing Variables If Needed
#os.environ["DOWNLOAD_LOCATION_PATH"] = "some_path"
#os.environ["BUCKET_NAME"] = "some_bucket"
#os.environ["AWS_ACCESS_KEY"] = "some_access_key"
#os.environ["AWS_SECRET_KEY"] = "some_secret"
#os.environ["LOG_LEVEL_SELECTOR"] = "DEBUG, INFO, or ERROR"

#Setting Log Level Test
logger = logging.getLogger('json')
logger.addHandler(json_handler_out)
logger_levels = {
    'ERROR' : logging.ERROR,
    'INFO' : logging.INFO,
    'DEBUG' : logging.DEBUG
}
logger_level_selector = os.environ["LOG_LEVEL_SELECTOR"]
logger.setLevel(logger_level_selector)

#Getting Date/Time
now = datetime.now()
logger.info("Current date and time : ")
logger.info(now.strftime("%Y-%m-%d %H:%M:%S"))

#Establishing S3 Variables and Download Location
download_location_path = os.environ["DOWNLOAD_LOCATION_PATH"]
bucket_name = os.environ["BUCKET_NAME"]
aws_access_key_id = os.environ["AWS_ACCESS_KEY"]
aws_access_secret_key = os.environ["AWS_SECRET_KEY"]
logger.debug("Bucket: %s" % bucket_name)
logger.debug("Key: %s" % aws_access_key_id)
logger.debug("Secret: %s" % aws_access_secret_key)
logger.debug("Download location path: %s" % download_location_path)

#Creating Download Directory
if not os.path.exists(download_location_path):
    logger.info("Making download directory")
    os.makedirs(download_location_path)

#Signal Hooks are fun
class GracefulKiller:
    kill_now = False
    def __init__(self):
        signal.signal(signal.SIGINT, self.exit_gracefully)
        signal.signal(signal.SIGTERM, self.exit_gracefully)
    def exit_gracefully(self, signum, frame):
        self.kill_now = True

#Downloading from S3 Bucket
def download_s3_bucket():
    conn = boto.connect_s3(aws_access_key_id, aws_access_secret_key)
    logger.debug("Connection established: ")
    bucket = conn.get_bucket(bucket_name)
    logger.debug("Bucket: %s" % str(bucket))
    bucket_list = bucket.list()
#    logger.info("Number of items to download: {0}".format(len(bucket_list)))

    for s3_item in bucket_list:
        key_string = str(s3_item.key)
        logger.debug("S3 Bucket Item to download: %s" % key_string)
        s3_path = download_location_path + "/" + key_string
        logger.debug("Downloading to: %s" % s3_path)
        local_dir = os.path.dirname(s3_path)

        if not os.path.exists(local_dir):
            logger.info("Local directory doesn't exist, creating it... %s" % local_dir)
            os.makedirs(local_dir)
            logger.info("Updating local directory permissions to %s" % local_dir)
#Comment or Uncomment Permissions based on Local Usage
            os.chmod(local_dir, 0o775)
            os.chown(local_dir, 60001, 60001)
        logger.debug("Local directory for download: %s" % local_dir)
        try:
            logger.info("Downloading File: %s" % key_string)
            s3_item.get_contents_to_filename(s3_path)
            logger.info("Successfully downloaded File: %s" % s3_path)
            #Updating Permissions
            logger.info("Updating Permissions for %s" % str(s3_path))
#Comment or Uncomment Permissions based on Local Usage
            os.chmod(s3_path, 0o664)
            os.chown(s3_path, 60001, 60001)
        except (OSError, S3ResponseError) as e:
            logger.error("Fatal error in s3_item.get_contents_to_filename", exc_info=True)
            # logger.error("Exception in file download from S3: {}".format(e))
            continue
        logger.info("Deleting %s from S3 Bucket" % str(s3_item.key))
        s3_item.delete()

def main():
    killer = GracefulKiller()
    while not killer.kill_now:
        logger.info("Checking for new files on S3 to download...")
        download_s3_bucket()
        logger.info("Done checking for new files, will check in 120s...")
        gc.collect()
        sys.stdout.flush()
        time.sleep(120)
if __name__ == '__main__':
    main()

How to Call Controller Actions using JQuery in ASP.NET MVC

In response to the above post I think it needs this line instead of your line:-

var strMethodUrl = '@Url.Action("SubMenu_Click", "Logging")?param1='+value1+' &param2='+value2

Or else you send the actual strings value1 and value2 to the controller.

However, for me, it only calls the controller once. It seems to hit 'receieveResponse' each time, but a break point on the controller method shows it is only hit 1st time until a page refresh.


Here is a working solution. For the cshtml page:-

   <button type="button" onclick="ButtonClick();"> Call &raquo;</button>

<script>
    function ButtonClick()
    {
        callControllerMethod2("1", "2");
    }
    function callControllerMethod2(value1, value2)
    {
        var response = null;
        $.ajax({
            async: true,
            url: "Logging/SubMenu_Click?param1=" + value1 + " &param2=" + value2,
            cache: false,
            dataType: "json",
            success: function (data) { receiveResponse(data); }
        });
    }
    function receiveResponse(response)
    {
        if (response != null)
        {
            for (var i = 0; i < response.length; i++)
            {
                alert(response[i].Data);
            }
        }
    }
</script>

And for the controller:-

public class A
{
    public string Id { get; set; }
    public string Data { get; set; }

}
public JsonResult SubMenu_Click(string param1, string param2)
{
    A[] arr = new A[] {new A(){ Id = "1", Data = DateTime.Now.Millisecond.ToString() } };
    return Json(arr , JsonRequestBehavior.AllowGet);
}

You can see the time changing each time it is called, so there is no caching of the values...

WCF named pipe minimal example

I just found this excellent little tutorial. broken link (Cached version)

I also followed Microsoft's tutorial which is nice, but I only needed pipes as well.

As you can see, you don't need configuration files and all that messy stuff.

By the way, he uses both HTTP and pipes. Just remove all code lines related to HTTP, and you'll get a pure pipe example.

How to sign an android apk file

Don't worry...! Follow these below steps and you will get your signed .apk file. I was also worry about that, but these step get ride me off from the frustration. Steps to sign your application:

  1. Export the unsigned package:

Right click on the project in Eclipse -> Android Tools -> Export Unsigned Application Package (like here we export our GoogleDriveApp.apk to Desktop)

Sign the application using your keystore and the jarsigner tool (follow below steps):

Open cmd-->change directory where your "jarsigner.exe" exist (like here in my system it exist at "C:\Program Files\Java\jdk1.6.0_17\bin"

Now enter belwo command in cmd:

jarsigner -verbose -keystore c:\users\android\debug.keystore c:\users\pir fahim\Desktops\GoogleDriveApp.apk my_keystore_alias

It will ask you to provide your password: Enter Passphrase for keystore: It will sign your apk.To verify that the signing is successful you can run:

jarsigner -verify c:\users\pir fahim\Desktops\GoogleDriveApp.apk

It should come back with: jar verified.

Method 2

If you are using eclipse with ADT, then it is simple to compiled, signed, aligned, and ready the file for distribution.what you have to do just follow this steps.

  • File > Export.
  • Export android application
  • Browse-->select your project
  • Next-->Next

These steps will compiled, signed and zip aligned your project and now you are ready to distribute your project or upload at Google Play store.

Understanding __get__ and __set__ and Python descriptors

You'd see https://docs.python.org/3/howto/descriptor.html#properties

class Property(object):
    "Emulate PyProperty_Type() in Objects/descrobject.c"

    def __init__(self, fget=None, fset=None, fdel=None, doc=None):
        self.fget = fget
        self.fset = fset
        self.fdel = fdel
        if doc is None and fget is not None:
            doc = fget.__doc__
        self.__doc__ = doc

    def __get__(self, obj, objtype=None):
        if obj is None:
            return self
        if self.fget is None:
            raise AttributeError("unreadable attribute")
        return self.fget(obj)

    def __set__(self, obj, value):
        if self.fset is None:
            raise AttributeError("can't set attribute")
        self.fset(obj, value)

    def __delete__(self, obj):
        if self.fdel is None:
            raise AttributeError("can't delete attribute")
        self.fdel(obj)

    def getter(self, fget):
        return type(self)(fget, self.fset, self.fdel, self.__doc__)

    def setter(self, fset):
        return type(self)(self.fget, fset, self.fdel, self.__doc__)

    def deleter(self, fdel):
        return type(self)(self.fget, self.fset, fdel, self.__doc__)

Use placeholders in yaml

With Yglu Structural Templating, your example can be written:

foo: !()
  !? $.propname: 
     type: number 
     default: !? $.default

bar:
  !apply .foo: 
    propname: "some_prop"
    default: "some default"

Disclaimer: I am the author or Yglu.

SQL count rows in a table

Why don't you just right click on the table and then properties -> Storage and it would tell you the row count. You can use the below for row count in a view

SELECT SUM (row_count) 
FROM sys.dm_db_partition_stats 
WHERE object_id=OBJECT_ID('Transactions')    
AND (index_id=0 or index_id=1)`

Launch Minecraft from command line - username and password as prefix

You can do this, you just need to circumvent the launcher.

In %appdata%\.minecraft\bin (or ~/.minecraft/bin on unixy systems), there is a minecraft.jar file. This is the actual game - the launcher runs this.

Invoke it like so:

java -Xms512m -Xmx1g -Djava.library.path=natives/ -cp "minecraft.jar;lwjgl.jar;lwjgl_util.jar" net.minecraft.client.Minecraft <username> <sessionID>

Set the working directory to .minecraft/bin.

To get the session ID, POST (request this page):

https://login.minecraft.net?user=<username>&password=<password>&version=13

You'll get a response like this:

1343825972000:deprecated:SirCmpwn:7ae9007b9909de05ea58e94199a33b30c310c69c:dba0c48e1c584963b9e93a038a66bb98

The fourth field is the session ID. More details here. Read those details, this answer is outdated

Here's an example of logging in to minecraft.net in C#.

How to convert string to integer in C#

bool result = Int32.TryParse(someString, out someNumeric)

This method will try to convert someString into someNumeric, and return a result depends if the conversion is successful, true if conversion is successful and false if conversion failed. Take note that this method will not throw exception if the conversion failed like how Int32.Parse method did and instead it returns zero for someNumeric.

For more information, you can read here:

https://msdn.microsoft.com/en-us/library/f02979c7(v=vs.110).aspx?cs-save-lang=1&cs-lang=csharp#code-snippet-2
&
How to convert string to integer in C#

PHP: Split string into array, like explode with no delimiter

str_split can do the trick. Note that strings in PHP can be accessed just like a chars array, in most cases, you won't need to split your string into a "new" array.

ModelState.AddModelError - How can I add an error that isn't for a property?

I eventually stumbled upon an example of the usage I was looking for - to assign an error to the Model in general, rather than one of it's properties, as usual you call:

ModelState.AddModelError(string key, string errorMessage);

but use an empty string for the key:

ModelState.AddModelError(string.Empty, "There is something wrong with Foo.");

The error message will present itself in the <%: Html.ValidationSummary() %> as you'd expect.

sqlalchemy filter multiple columns

A generic piece of code that will work for multiple columns. This can also be used if there is a need to conditionally implement search functionality in the application.

search_key = "abc"
search_args = [col.ilike('%%%s%%' % search_key) for col in ['col1', 'col2', 'col3']]
query = Query(table).filter(or_(*search_args))
session.execute(query).fetchall()

Note: the %% are important to skip % formatting the query.

Difference between no-cache and must-revalidate

I believe that must-revalidate means :

Once the cache expires, refuse to return stale responses to the user even if they say that stale responses are acceptable.

Whereas no-cache implies :

must-revalidate plus the fact the response becomes stale right away.

If a response is cacheable for 10 seconds, then must-revalidate kicks in after 10 seconds, whereas no-cache implies must-revalidate after 0 seconds.

At least, that's my interpretation.

Call JavaScript function on DropDownList SelectedIndexChanged Event:

Or you can do it like as well:

<asp:DropDownList ID="ddl" runat="server"  AutoPostBack="true" onchange="javascript:CalcTotalAmt();" OnSelectedIndexChanged="ddl_SelectedIndexChanged"></asp:DropDownList>

Upgrading PHP in XAMPP for Windows?

Take a backup of your htdocs and data folder (subfolder of MySQL folder), reinstall upgraded version and replace those folders.

Note: In case you have changed config files like PHP (php.ini), Apache (httpd.conf) or any other, please take back up of those files as well and replace them with newly installed version.

change image opacity using javascript

Supposing you're using plain JS (see other answers for jQuery), to change an element's opacity, write:

var element = document.getElementById('id');
element.style.opacity = "0.9";
element.style.filter  = 'alpha(opacity=90)'; // IE fallback

iCheck check if checkbox is checked

Use following code to check if iCheck is checked or not using single method.

$('Selector').on('ifChanged', function(event){

    //Check if checkbox is checked or not
    var checkboxChecked = $(this).is(':checked');

    if(checkboxChecked) {
        alert("checked");
    }else{
        alert("un-checked");
    }
});

What does this GCC error "... relocation truncated to fit..." mean?

Often, this error means your program is too large, and often it's too large because it contains one or more very large data objects. For example,

char large_array[1ul << 31];
int other_global;
int main(void) { return other_global; }

will produce a "relocation truncated to fit" error on x86-64/Linux, if compiled in the default mode and without optimization. (If you turn on optimization, it could, at least theoretically, figure out that large_array is unused and/or that other_global is never written, and thus generate code that doesn't trigger the problem.)

What's going on is that, by default, GCC uses its "small code model" on this architecture, in which all of the program's code and statically allocated data must fit into the lowest 2GB of the address space. (The precise upper limit is something like 2GB - 2MB, because the very lowest 2MB of any program's address space is permanently unusable. If you are compiling a shared library or position-independent executable, all of the code and data must still fit into two gigabytes, but they're not nailed to the bottom of the address space anymore.) large_array consumes all of that space by itself, so other_global is assigned an address above the limit, and the code generated for main cannot reach it. You get a cryptic error from the linker, rather than a helpful "large_array is too large" error from the compiler, because in more complex cases the compiler can't know that other_global will be out of reach, so it doesn't even try for the simple cases.

Most of the time, the correct response to getting this error is to refactor your program so that it doesn't need gigantic static arrays and/or gigabytes of machine code. However, if you really have to have them for some reason, you can use the "medium" or "large" code models to lift the limits, at the price of somewhat less efficient code generation. These code models are x86-64-specific; something similar exists for most other architectures, but the exact set of "models" and the associated limits will vary. (On a 32-bit architecture, for instance, you might have a "small" model in which the total amount of code and data was limited to something like 224 bytes.)

Merge trunk to branch in Subversion

Is there something that prevents you from merging all revisions on trunk since the last merge?

svn merge -rLastRevisionMergedFromTrunkToBranch:HEAD url/of/trunk path/to/branch/wc

should work just fine. At least if you want to merge all changes on trunk to your branch.

Please explain about insertable=false and updatable=false in reference to the JPA @Column annotation

I would like to add to the answers of BalusC and Pascal Thivent another common use of insertable=false, updatable=false:

Consider a column that is not an id but some kind of sequence number. The responsibility for calculating the sequence number may not necessarily belong to the application.

For example, sequence number starts with 1000 and should increment by one for each new entity. This is easily done, and very appropriately so, in the database, and in such cases these configurations makes sense.

Can I pass a JavaScript variable to another browser window?

One can pass a message from the 'parent' window to the 'child' window:

in the 'parent window' open the child

    var win = window.open(<window.location.href>, '_blank');    
       setTimeout(function(){
                    win.postMessage(SRFBfromEBNF,"*")
                  },1000);
    win.focus();

the to be replaced according to the context

In the 'child'

    window.addEventListener('message', function(event) {
        if(event.srcElement.location.href==window.location.href){
        /* do what you want with event.data */
        }
    }); 

The if test must be changed according to the context

How to find the .NET framework version of a Visual Studio project?

Simple Right Click and go to Properties Option of any project on your Existing application and see the Application option on Left menu and then click on Application option see target Framework to see current Framework version .

How can I insert into a BLOB column from an insert statement in sqldeveloper?

To insert a VARCHAR2 into a BLOB column you can rely on the function utl_raw.cast_to_raw as next:

insert into mytable(id, myblob) values (1, utl_raw.cast_to_raw('some magic here'));

It will cast your input VARCHAR2 into RAW datatype without modifying its content, then it will insert the result into your BLOB column.

More details about the function utl_raw.cast_to_raw

Set up adb on Mac OS X

If you are setting the path in Catalina use below command one after another in the terminal. It's working fine for me.

export ANDROID_HOME=/Users/$USER/Library/Android/sdk
export PATH=${PATH}:$ANDROID_HOME/tools:$ANDROID_HOME/platform-tools

source ~/.bash_profile

How can I tell jackson to ignore a property for which I don't have control over the source code?

I had a similar issue, but it was related to Hibernate's bi-directional relationships. I wanted to show one side of the relationship and programmatically ignore the other, depending on what view I was dealing with. If you can't do that, you end up with nasty StackOverflowExceptions. For instance, if I had these objects

public class A{
  Long id;
  String name;
  List<B> children;
}

public class B{
  Long id;
  A parent;
}

I would want to programmatically ignore the parent field in B if I were looking at A, and ignore the children field in A if I were looking at B.

I started off using mixins to do this, but that very quickly becomes horrible; you have so many useless classes laying around that exist solely to format data. I ended up writing my own serializer to handle this in a cleaner way: https://github.com/monitorjbl/json-view.

It allows you programmatically specify what fields to ignore:

ObjectMapper mapper = new ObjectMapper();
SimpleModule module = new SimpleModule();
module.addSerializer(JsonView.class, new JsonViewSerializer());
mapper.registerModule(module);

List<A> list = getListOfA();
String json = mapper.writeValueAsString(JsonView.with(list)
    .onClass(B.class, match()
        .exclude("parent")));

It also lets you easily specify very simplified views through wildcard matchers:

String json = mapper.writeValueAsString(JsonView.with(list)
    .onClass(A.class, match()
        .exclude("*")
         .include("id", "name")));

In my original case, the need for simple views like this was to show the bare minimum about the parent/child, but it also became useful for our role-based security. Less privileged views of objects needed to return less information about the object.

All of this comes from the serializer, but I was using Spring MVC in my app. To get it to properly handle these cases, I wrote an integration that you can drop in to existing Spring controller classes:

@Controller
public class JsonController {
  private JsonResult json = JsonResult.instance();
  @Autowired
  private TestObjectService service;

  @RequestMapping(method = RequestMethod.GET, value = "/bean")
  @ResponseBody
  public List<TestObject> getTestObject() {
    List<TestObject> list = service.list();

    return json.use(JsonView.with(list)
        .onClass(TestObject.class, Match.match()
            .exclude("int1")
            .include("ignoredDirect")))
        .returnValue();
  }
}

Both are available on Maven Central. I hope it helps someone else out there, this is a particularly ugly problem with Jackson that didn't have a good solution for my case.

document.getElementById(id).focus() is not working for firefox or chrome

2 things to mention if focus() not working:

  • use this function after appending to parent
  • if console is selected, after refreshing page, element will not gain focus, so select (click on) the webpage while testing

This way works in both Firefox and Chrome without any setTimeOut().

How can I find the version of php that is running on a distinct domain name?

There is a surprisingly effective way that consists of using the easter eggs.

They differ from version to version.

jQuery get selected option value (not the text, but the attribute 'value')

It's working better. Try it.

let value = $("select#yourId option").filter(":selected").val();

PostgreSQL return result set as JSON array?

TL;DR

SELECT json_agg(t) FROM t

for a JSON array of objects, and

SELECT
    json_build_object(
        'a', json_agg(t.a),
        'b', json_agg(t.b)
    )
FROM t

for a JSON object of arrays.

List of objects

This section describes how to generate a JSON array of objects, with each row being converted to a single object. The result looks like this:

[{"a":1,"b":"value1"},{"a":2,"b":"value2"},{"a":3,"b":"value3"}]

9.3 and up

The json_agg function produces this result out of the box. It automatically figures out how to convert its input into JSON and aggregates it into an array.

SELECT json_agg(t) FROM t

There is no jsonb (introduced in 9.4) version of json_agg. You can either aggregate the rows into an array and then convert them:

SELECT to_jsonb(array_agg(t)) FROM t

or combine json_agg with a cast:

SELECT json_agg(t)::jsonb FROM t

My testing suggests that aggregating them into an array first is a little faster. I suspect that this is because the cast has to parse the entire JSON result.

9.2

9.2 does not have the json_agg or to_json functions, so you need to use the older array_to_json:

SELECT array_to_json(array_agg(t)) FROM t

You can optionally include a row_to_json call in the query:

SELECT array_to_json(array_agg(row_to_json(t))) FROM t

This converts each row to a JSON object, aggregates the JSON objects as an array, and then converts the array to a JSON array.

I wasn't able to discern any significant performance difference between the two.

Object of lists

This section describes how to generate a JSON object, with each key being a column in the table and each value being an array of the values of the column. It's the result that looks like this:

{"a":[1,2,3], "b":["value1","value2","value3"]}

9.5 and up

We can leverage the json_build_object function:

SELECT
    json_build_object(
        'a', json_agg(t.a),
        'b', json_agg(t.b)
    )
FROM t

You can also aggregate the columns, creating a single row, and then convert that into an object:

SELECT to_json(r)
FROM (
    SELECT
        json_agg(t.a) AS a,
        json_agg(t.b) AS b
    FROM t
) r

Note that aliasing the arrays is absolutely required to ensure that the object has the desired names.

Which one is clearer is a matter of opinion. If using the json_build_object function, I highly recommend putting one key/value pair on a line to improve readability.

You could also use array_agg in place of json_agg, but my testing indicates that json_agg is slightly faster.

There is no jsonb version of the json_build_object function. You can aggregate into a single row and convert:

SELECT to_jsonb(r)
FROM (
    SELECT
        array_agg(t.a) AS a,
        array_agg(t.b) AS b
    FROM t
) r

Unlike the other queries for this kind of result, array_agg seems to be a little faster when using to_jsonb. I suspect this is due to overhead parsing and validating the JSON result of json_agg.

Or you can use an explicit cast:

SELECT
    json_build_object(
        'a', json_agg(t.a),
        'b', json_agg(t.b)
    )::jsonb
FROM t

The to_jsonb version allows you to avoid the cast and is faster, according to my testing; again, I suspect this is due to overhead of parsing and validating the result.

9.4 and 9.3

The json_build_object function was new to 9.5, so you have to aggregate and convert to an object in previous versions:

SELECT to_json(r)
FROM (
    SELECT
        json_agg(t.a) AS a,
        json_agg(t.b) AS b
    FROM t
) r

or

SELECT to_jsonb(r)
FROM (
    SELECT
        array_agg(t.a) AS a,
        array_agg(t.b) AS b
    FROM t
) r

depending on whether you want json or jsonb.

(9.3 does not have jsonb.)

9.2

In 9.2, not even to_json exists. You must use row_to_json:

SELECT row_to_json(r)
FROM (
    SELECT
        array_agg(t.a) AS a,
        array_agg(t.b) AS b
    FROM t
) r

Documentation

Find the documentation for the JSON functions in JSON functions.

json_agg is on the aggregate functions page.

Design

If performance is important, ensure you benchmark your queries against your own schema and data, rather than trust my testing.

Whether it's a good design or not really depends on your specific application. In terms of maintainability, I don't see any particular problem. It simplifies your app code and means there's less to maintain in that portion of the app. If PG can give you exactly the result you need out of the box, the only reason I can think of to not use it would be performance considerations. Don't reinvent the wheel and all.

Nulls

Aggregate functions typically give back NULL when they operate over zero rows. If this is a possibility, you might want to use COALESCE to avoid them. A couple of examples:

SELECT COALESCE(json_agg(t), '[]'::json) FROM t

Or

SELECT to_jsonb(COALESCE(array_agg(t), ARRAY[]::t[])) FROM t

Credit to Hannes Landeholm for pointing this out

Running ASP.Net on a Linux based server

There is the Mono Project from Novell that will allow you to run ASP.Net on Apache.

http://www.mono-project.com/Main_Page

Batchfile to create backup and rename with timestamp

See if this is what you want to do:

@echo off
for /f "delims=" %%a in ('wmic OS Get localdatetime  ^| find "."') do set dt=%%a
set YYYY=%dt:~0,4%
set MM=%dt:~4,2%
set DD=%dt:~6,2%
set HH=%dt:~8,2%
set Min=%dt:~10,2%
set Sec=%dt:~12,2%

set stamp=%YYYY%-%MM%-%DD%_%HH%-%Min%-%Sec%

copy "F:\Folder\File 1.xlsx" "F:\Folder\Archive\File 1 - %stamp%.xlsx"

How do I escape spaces in path for scp copy in Linux?

Use 3 backslashes to escape spaces in names of directories:

scp user@host:/path/to/directory\\\ with\\\ spaces/file ~/Downloads

should copy to your Downloads directory the file from the remote directory called directory with spaces.

javascript unexpected identifier

Yes, you have a } too many. Anyway, compressing yourself tends to result in errors.

function () {
    if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
        document.getElementById("content").innerHTML = xmlhttp.responseText;
    }
} // <-- end function?
xmlhttp.open("GET", "data/" + id + ".html", true);
xmlhttp.send();
}

Use Closure Compiler instead.

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

This one worked for me:

>> print(df)
                          TotalVolume  Symbol
2016-04-15 09:00:00       108400       2802.T
2016-04-15 09:05:00       50300        2802.T

>> print(df.set_index(pd.to_datetime(df.index.values) - datetime(2016, 4, 15)))

             TotalVolume  Symbol
09:00:00     108400       2802.T
09:05:00     50300        2802.T

Add alternating row color to SQL Server Reporting services report

Go to the table row's BackgroundColor property and choose "Expression..."

Use this expression:

= IIf(RowNumber(Nothing) Mod 2 = 0, "Silver", "Transparent")

This trick can be applied to many areas of the report.

And in .NET 3.5+ You could use:

= If(RowNumber(Nothing) Mod 2 = 0, "Silver", "Transparent")

Not looking for rep--I just researched this question myself and thought I'd share.

ng-change get new value and original value

You can use something like ng-change=someMethod({{user.id}}). By keeping your value in side {{expression}} it will evaluate expression in-line and gives you current value(value before ng-change method is called).

<select ng-model="selectedValue" ng-change="change(selectedValue, '{{selectedValue}}')">

How to set min-font-size in CSS

Looks like I'm a bit late but for others with this issue try this code

p { font-size: 3vmax; }

use whatever tag you prefer and size you prefer (replace the 3)

p { font-size: 3vmin; }

is used for a max size.

sqlplus statement from command line

My version

$ sqlplus -s username/password@host:port/service <<< "select 1 from dual;"


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

EDIT:

For multiline you can use this

$ echo -e "select 1 from dual; \n select 2 from dual;" | sqlplus -s username/password@host:port/service


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


         2
----------
         2

Flutter: Trying to bottom-center an item in a Column, but it keeps left-aligning

Widget _bottom() {
    return Column(
      mainAxisAlignment: MainAxisAlignment.start,
      children: [
        Expanded(
          child: Container(
            color: Colors.amberAccent,
            width: double.infinity,
            child: SingleChildScrollView(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.start,
                crossAxisAlignment: CrossAxisAlignment.start,
                children: new List<int>.generate(50, (index) => index + 1)
                    .map((item) {
                  return Text(
                    item.toString(),
                    style: TextStyle(fontSize: 20),
                  );
                }).toList(),
              ),
            ),
          ),
        ),
        Container(
          color: Colors.blue,
          child: Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Text(
                'BoTToM',
                textAlign: TextAlign.center,
                style: TextStyle(fontSize: 33),
              ),
            ],
          ),
        ),
      ],
    );
  }

Git asks for username every time I push

You can just run

git config --global credential.helper wincred

after installing and logging into GIT for windows in your system.

Verilog: How to instantiate a module

This is all generally covered by Section 23.3.2 of SystemVerilog IEEE Std 1800-2012.

The simplest way is to instantiate in the main section of top, creating a named instance and wiring the ports up in order:

module top(
   input        clk,
   input        rst_n,
   input        enable,
   input  [9:0] data_rx_1,
   input  [9:0] data_rx_2,
   output [9:0] data_tx_2
);

subcomponent subcomponent_instance_name (
  clk, rst_n, data_rx_1, data_tx ); 

endmodule

This is described in Section 23.3.2.1 of SystemVerilog IEEE Std 1800-2012.

This has a few draw backs especially regarding the port order of the subcomponent code. simple refactoring here can break connectivity or change behaviour. for example if some one else fixs a bug and reorders the ports for some reason, switching the clk and reset order. There will be no connectivity issue from your compiler but will not work as intended.

module subcomponent(
  input        rst_n,       
  input        clk,
  ...

It is therefore recommended to connect using named ports, this also helps tracing connectivity of wires in the code.

module top(
   input        clk,
   input        rst_n,
   input        enable,
   input  [9:0] data_rx_1,
   input  [9:0] data_rx_2,
   output [9:0] data_tx_2
);

subcomponent subcomponent_instance_name (
  .clk(clk), .rst_n(rst_n), .data_rx(data_rx_1), .data_tx(data_tx) ); 

endmodule

This is described in Section 23.3.2.2 of SystemVerilog IEEE Std 1800-2012.

Giving each port its own line and indenting correctly adds to the readability and code quality.

subcomponent subcomponent_instance_name (
  .clk      ( clk       ), // input
  .rst_n    ( rst_n     ), // input
  .data_rx  ( data_rx_1 ), // input  [9:0]
  .data_tx  ( data_tx   )  // output [9:0]
);

So far all the connections that have been made have reused inputs and output to the sub module and no connectivity wires have been created. What happens if we are to take outputs from one component to another:

clk_gen( 
  .clk      ( clk_sub   ), // output
  .en       ( enable    )  // input

subcomponent subcomponent_instance_name (
  .clk      ( clk_sub   ), // input
  .rst_n    ( rst_n     ), // input 
  .data_rx  ( data_rx_1 ), // input  [9:0]
  .data_tx  ( data_tx   )  // output [9:0]
);

This nominally works as a wire for clk_sub is automatically created, there is a danger to relying on this. it will only ever create a 1 bit wire by default. An example where this is a problem would be for the data:

Note that the instance name for the second component has been changed

subcomponent subcomponent_instance_name (
  .clk      ( clk_sub   ), // input
  .rst_n    ( rst_n     ), // input 
  .data_rx  ( data_rx_1 ), // input  [9:0]
  .data_tx  ( data_temp )  // output [9:0]
);
subcomponent subcomponent_instance_name2 (
  .clk      ( clk_sub   ), // input
  .rst_n    ( rst_n     ), // input 
  .data_rx  ( data_temp ), // input  [9:0]
  .data_tx  ( data_tx   )  // output [9:0]
);

The issue with the above code is that data_temp is only 1 bit wide, there would be a compile warning about port width mismatch. The connectivity wire needs to be created and a width specified. I would recommend that all connectivity wires be explicitly written out.

wire [9:0] data_temp
subcomponent subcomponent_instance_name (
  .clk      ( clk_sub   ), // input
  .rst_n    ( rst_n     ), // input 
  .data_rx  ( data_rx_1 ), // input  [9:0]
  .data_tx  ( data_temp )  // output [9:0]
);
subcomponent subcomponent_instance_name2 (
  .clk      ( clk_sub   ), // input
  .rst_n    ( rst_n     ), // input 
  .data_rx  ( data_temp ), // input  [9:0]
  .data_tx  ( data_tx   )  // output [9:0]
);

Moving to SystemVerilog there are a few tricks available that save typing a handful of characters. I believe that they hinder the code readability and can make it harder to find bugs.

Use .port with no brackets to connect to a wire/reg of the same name. This can look neat especially with lots of clk and resets but at some levels you may generate different clocks or resets or you actually do not want to connect to the signal of the same name but a modified one and this can lead to wiring bugs that are not obvious to the eye.

module top(
   input        clk,
   input        rst_n,
   input        enable,
   input  [9:0] data_rx_1,
   input  [9:0] data_rx_2,
   output [9:0] data_tx_2
);

subcomponent subcomponent_instance_name (
  .clk,                    // input **Auto connect**
  .rst_n,                  // input **Auto connect**
  .data_rx  ( data_rx_1 ), // input  [9:0]
  .data_tx  ( data_tx   )  // output [9:0]
);

endmodule

This is described in Section 23.3.2.3 of SystemVerilog IEEE Std 1800-2012.

Another trick that I think is even worse than the one above is .* which connects unmentioned ports to signals of the same wire. I consider this to be quite dangerous in production code. It is not obvious when new ports have been added and are missing or that they might accidentally get connected if the new port name had a counter part in the instancing level, they get auto connected and no warning would be generated.

subcomponent subcomponent_instance_name (
  .*,                      // **Auto connect**
  .data_rx  ( data_rx_1 ), // input  [9:0]
  .data_tx  ( data_tx   )  // output [9:0]
);

This is described in Section 23.3.2.4 of SystemVerilog IEEE Std 1800-2012.

jquery how to use multiple ajax calls one after the end of the other

You could also use jquery when and then functions. for example

 $.when( $.ajax( "test.aspx" ) ).then(function( data, textStatus, jqXHR ) {
  //another ajax call
});

https://api.jquery.com/jQuery.when/

Finding the source code for built-in Python functions?

Quite an unknown resource is the Python Developer Guide.

In a (somewhat) recent GH issue, a new chapter was added for to address the question you're asking: CPython Source Code Layout. If something should change, that resource will also get updated.

Split comma-separated input box values into array in jquery, and loop through it

var array = $('#searchKeywords').val().split(",");

then

$.each(array,function(i){
   alert(array[i]);
});

OR

for (i=0;i<array.length;i++){
     alert(array[i]);
}

How to select only 1 row from oracle sql?

There is no limit 1 condition (thats MySQL / PostgresSQL) in Oracle, you need to specify where rownum = 1.

How to invoke a Linux shell command from Java

Building on @Tim's example to make a self-contained method:

import java.io.BufferedReader;
import java.io.File;
import java.io.InputStreamReader;
import java.util.ArrayList;

public class Shell {

    /** Returns null if it failed for some reason.
     */
    public static ArrayList<String> command(final String cmdline,
    final String directory) {
        try {
            Process process = 
                new ProcessBuilder(new String[] {"bash", "-c", cmdline})
                    .redirectErrorStream(true)
                    .directory(new File(directory))
                    .start();

            ArrayList<String> output = new ArrayList<String>();
            BufferedReader br = new BufferedReader(
                new InputStreamReader(process.getInputStream()));
            String line = null;
            while ( (line = br.readLine()) != null )
                output.add(line);

            //There should really be a timeout here.
            if (0 != process.waitFor())
                return null;

            return output;

        } catch (Exception e) {
            //Warning: doing this is no good in high quality applications.
            //Instead, present appropriate error messages to the user.
            //But it's perfectly fine for prototyping.

            return null;
        }
    }

    public static void main(String[] args) {
        test("which bash");

        test("find . -type f -printf '%T@\\\\t%p\\\\n' "
            + "| sort -n | cut -f 2- | "
            + "sed -e 's/ /\\\\\\\\ /g' | xargs ls -halt");

    }

    static void test(String cmdline) {
        ArrayList<String> output = command(cmdline, ".");
        if (null == output)
            System.out.println("\n\n\t\tCOMMAND FAILED: " + cmdline);
        else
            for (String line : output)
                System.out.println(line);

    }
}

(The test example is a command that lists all files in a directory and its subdirectories, recursively, in chronological order.)

By the way, if somebody can tell me why I need four and eight backslashes there, instead of two and four, I can learn something. There is one more level of unescaping happening than what I am counting.

Edit: Just tried this same code on Linux, and there it turns out that I need half as many backslashes in the test command! (That is: the expected number of two and four.) Now it's no longer just weird, it's a portability problem.

how to run command "mysqladmin flush-hosts" on Amazon RDS database Server instance?

On Amazon RDS FLUSH HOSTS; can be executed from default user ("Master Username" in RDS info), and it helps.

Why is super.super.method(); not allowed in Java?

Calling of super.super.method() make sense when you can't change code of base class. This often happens when you are extending an existing library.

Ask yourself first, why are you extending that class? If answer is "because I can't change it" then you can create exact package and class in your application, and rewrite naughty method or create delegate:

package com.company.application;

public class OneYouWantExtend extends OneThatContainsDesiredMethod {

    // one way is to rewrite method() to call super.method() only or 
    // to doStuff() and then call super.method()

    public void method() {
        if (isDoStuff()) {
            // do stuff
        }
        super.method();
    }

    protected abstract boolean isDoStuff();


    // second way is to define methodDelegate() that will call hidden super.method()

    public void methodDelegate() {
        super.method();
    }
    ...
}

public class OneThatContainsDesiredMethod {

    public void method() {...}
    ...
}

For instance, you can create org.springframework.test.context.junit4.SpringJUnit4ClassRunner class in your application so this class should be loaded before the real one from jar. Then rewrite methods or constructors.

Attention: This is absolute hack, and it is highly NOT recommended to use but it's WORKING! Using of this approach is dangerous because of possible issues with class loaders. Also this may cause issues each time you will update library that contains overwritten class.

Excel function to make SQL-like queries on worksheet data?

One quick way to do this is to create a column with a formula that evaluates to true for the rows you care about and then filter for the value TRUE in that column.

Find a file with a certain extension in folder

Use this code for read file with all type of extension file.

string[] sDirectoryInfo = Directory.GetFiles(SourcePath, "*.*");

PHP Connection failed: SQLSTATE[HY000] [2002] Connection refused

Using MAMP ON Mac, I solve my problem by renaming

/Applications/MAMP/tmp/mysql/mysql.sock.lock

to

/Applications/MAMP/tmp/mysql/mysql.sock

SQL time difference between two dates result in hh:mm:ss

declare @StartDate datetime, @EndDate datetime

select @StartDate = '10/01/2012 08:40:18.000',@EndDate='10/04/2012 09:52:48.000'

select convert(varchar(5),DateDiff(s, @startDate, @EndDate)/3600)+':'+convert(varchar(5),DateDiff(s, @startDate, @EndDate)%3600/60)+':'+convert(varchar(5),(DateDiff(s, @startDate, @EndDate)%60)) as [hh:mm:ss]

This query will helpful to you.

Run script with rc.local: script works, but not at boot

It is my understanding that if you place your script in a certain RUN Level, you should use ln -s to link the script to the level you want it to work in.

What are the differences between Visual Studio Code and Visual Studio?

I will provide a detailed differences between Visual Studio and Visual Studio Code below.

If you really look at it the most obvious difference is that .NET has been split into two:

  • .NET Core (Mac, Linux, and Windows)
  • .NET Framework (Windows only)

All native user interface technologies (Windows Presentation Foundation, Windows Forms, etc.) are part of the framework, not the core.

The "Visual" in Visual Studio (from Visual Basic) was largely synonymous with visual UI (drag & drop WYSIWYG) design, so in that sense, Visual Studio Code is Visual Studio without the Visual!

The second most obvious difference is that Visual Studio tends to be oriented around projects & solutions.

Visual Studio Code:

  • It's a lightweight source code editor which can be used to view, edit, run, and debug source code for applications.
  • Simply it is Visual Studio without the Visual UI, majorly a superman’s text-editor.
  • It is mainly oriented around files, not projects.
  • It does not have any scaffolding support.
  • It is a competitor of Sublime Text or Atom on Electron.
  • It is based on the Electron framework, which is used to build cross platform desktop application using web technologies.
  • It does not have support for Microsoft's version control system; Team Foundation Server.
  • It has limited IntelliSense for Microsoft file types and similar features.
  • It is mainly used by developers on a Mac who deal with client-side technologies (HTML, JavaScript, and CSS).

Visual Studio:

  • As the name indicates, it is an IDE, and it contains all the features required for project development. Like code auto completion, debugger, database integration, server setup, configurations, and so on.
  • It is a complete solution mostly used by and for .NET related developers. It includes everything from source control to bug tracker to deployment tools, etc. It has everything required to develop.
  • It is widely used on .NET related projects (though you can use it for other things). The community version is free, but if you want to make most of it then it is not free.
  • Visual Studio is aimed to be the world’s best IDE (integrated development environment), which provide full stack develop toolsets, including a powerful code completion component called IntelliSense, a debugger which can debug both source code and machine code, everything about ASP.NET development, and something about SQL development.

  • In the latest version of Visual Studio, you can develop cross-platform application without leaving the IDE. And Visual Studio takes more than 8 GB disk space (according to the components you select).

  • In brief, Visual Studio is an ultimate development environment, and it’s quite heavy.

Reference: https://www.quora.com/What-is-the-difference-between-Visual-Studio-and-Visual-Studio-Code

Conditional step/stage in Jenkins pipeline

According to other answers I am adding the parallel stages scenario:

pipeline {
    agent any
    stages {
        stage('some parallel stage') {
            parallel {
                stage('parallel stage 1') {
                    when {
                      expression { ENV == "something" }
                    }
                    steps {
                        echo 'something'
                    }
                }
                stage('parallel stage 2') {
                    steps {
                        echo 'something'
                    }
                }
            }
        }
    }
}

Items in JSON object are out of order using "json.dumps"?

Both Python dict (before Python 3.7) and JSON object are unordered collections. You could pass sort_keys parameter, to sort the keys:

>>> import json
>>> json.dumps({'a': 1, 'b': 2})
'{"b": 2, "a": 1}'
>>> json.dumps({'a': 1, 'b': 2}, sort_keys=True)
'{"a": 1, "b": 2}'

If you need a particular order; you could use collections.OrderedDict:

>>> from collections import OrderedDict
>>> json.dumps(OrderedDict([("a", 1), ("b", 2)]))
'{"a": 1, "b": 2}'
>>> json.dumps(OrderedDict([("b", 2), ("a", 1)]))
'{"b": 2, "a": 1}'

Since Python 3.6, the keyword argument order is preserved and the above can be rewritten using a nicer syntax:

>>> json.dumps(OrderedDict(a=1, b=2))
'{"a": 1, "b": 2}'
>>> json.dumps(OrderedDict(b=2, a=1))
'{"b": 2, "a": 1}'

See PEP 468 – Preserving Keyword Argument Order.

If your input is given as JSON then to preserve the order (to get OrderedDict), you could pass object_pair_hook, as suggested by @Fred Yankowski:

>>> json.loads('{"a": 1, "b": 2}', object_pairs_hook=OrderedDict)
OrderedDict([('a', 1), ('b', 2)])
>>> json.loads('{"b": 2, "a": 1}', object_pairs_hook=OrderedDict)
OrderedDict([('b', 2), ('a', 1)])

How do I access refs of a child component in the parent component

First of all, I want to say a big screw you to React for designing an interface that doesn't let us access 'ref' on the instantiated child components, in whatever context, without having to use the 'forwardRef' "hack" (which technically only works on specific/single instances, and not dynamic collections). Thanks for making our lives harder with your proprietary hook crap and now forcing us to use functional components (which can't inherit base functionality without more hacks). Why did JavaScript add class support to begin with? Right...

With that said, here is how I solve the problem for dynamic components:

On the parent, dynamically create references to the child components, for example:

class Form extends Component {
    fieldRefs: [];

    componentWillMount = () => {
        this.fieldRefs = [];
        for(let f of this.props.children) {
            if (f && f.type.name == 'FormField') {
                f.ref = createRef();
                this.fieldRefs.push(f);
            }
        }
    }

    public getFields = () => {
        let data = {};

        for(let r of this.fieldRefs) {
            let f = r.ref.current;
            data[f.props.id] = f.field.current.value;
        }

        return data;
    }
}

The Child component (ie <FormField />) implements it's own 'field' ref, to be referred to from the parent:

class FormField extends Component {
    field = createRef();
    
    render() {
        return(
            <input ref={this.field} type={type} />
        );
    }
}

Then in your main page, "Parent Parent" component, you can get the field values from the reference with:

class Page extends Component {
    form = createRef();

    onSubmit = () => {
        let fields = this.form.current.getFields();
    }

    render() {
        return (
            <Form ref={this.form}>
                <FormField id="email" type="email" autoComplete="email" label="E-mail" />
                <FormField id="password" type="password" autoComplete="password" label="Password" />

                <div class="button" onClick={this.onSubmit}>Submit</div>
            </Form>
        );
    }
}

I implemented this because I wanted to encapsulate all generic form functionality from a main <Form /> component, and the only way to be able to have the main client/page component set and style its own inner components was to use child components (ie. <FormField /> items within the parent <Form />, which is inside some other <Page /> component).

So, while some might consider this a hack, it's just as hackey as React's attempts to block the actual 'ref' from any parent, which I think is a ridiculous design, however they want to rationalize it.

Also wtf SO. It's 2021 and we still don't have get proper code-editing tools in your editor. Ffs.

How to do what head, tail, more, less, sed do in Powershell?

"-TotalCount" in this instance responds exactly like "-head". You have to use -TotalCount or -head to run the command like that. But -TotalCount is misleading - it does not work in ACTUALLY giving you ANY counts...

gc -TotalCount 25 C:\scripts\logs\robocopy_report.txt

The above script, tested in PS 5.1 is the SAME response as below...

gc -head 25 C:\scripts\logs\robocopy_report.txt

So then just use '-head 25" already!

Log4j: How to configure simplest possible file logging?

Here's a simple one that I often use:

# Set up logging to include a file record of the output
# Note: the file is always created, even if there is 
# no actual output.
log4j.rootLogger=error, stdout, R

# Log format to standard out
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=   %5p\t[%d] [%t] (%F:%L)\n     \t%m%n\n

# File based log output
log4j.appender.R=org.apache.log4j.RollingFileAppender
log4j.appender.R.File=owls_conditions.log
log4j.appender.R.MaxFileSize=10000KB
# Keep one backup file
log4j.appender.R.MaxBackupIndex=1
log4j.appender.R.layout=org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=   %5p\t[%d] [%t] (%F:%L)\n     \t%m%n\n

The format of the log is as follows:

ERROR   [2009-09-13 09:56:01,760] [main] (RDFDefaultErrorHandler.java:44)
        http://www.xfront.com/owl/ontologies/camera/#(line 1 column 1): Content is not allowed in prolog.

Such a format is defined by the string %5p\t[%d] [%t] (%F:%L)\n \t%m%n\n. You can read the meaning of conversion characters in log4j javadoc for PatternLayout.

Included comments should help in understanding what it does. Further notes:

  • it logs both to console and to file; in this case the file is named owls_conditions.log: change it according to your needs;
  • files are rotated when they reach 10000KB, and one back-up file is kept

Java recursive Fibonacci sequence

Try this

private static int fibonacci(int n){
    if(n <= 1)
        return n;
    return fibonacci(n - 1) + fibonacci(n - 2);
}

Java: Rotating Images

public static BufferedImage rotateCw( BufferedImage img )
{
    int         width  = img.getWidth();
    int         height = img.getHeight();
    BufferedImage   newImage = new BufferedImage( height, width, img.getType() );

    for( int i=0 ; i < width ; i++ )
        for( int j=0 ; j < height ; j++ )
            newImage.setRGB( height-1-j, i, img.getRGB(i,j) );

    return newImage;
}

from https://coderanch.com/t/485958/java/Rotating-buffered-image

What is an Endpoint?

API stands for Application Programming Interface. It is a way for your application to interact with other applications via an endpoint. Conversely, you can build out an API for your application that is available for other developers to utilize/connect to via HTTP methods, which are RESTful. Representational State Transfer (REST):

  • GET: Retrieve data from an API endpoint.
  • PUT: Update data via an API - similar to POST but more about updating info.
  • POST: Send data to an API.
  • DELETE: Remove data from given API.

Cannot declare instance members in a static class in C#

As John Weldon said all members must be static in a static class. Try

public static class employee
{
     static NameValueCollection appSetting = ConfigurationManager.AppSettings;    

}

how to get docker-compose to use the latest image from repository

Since 2020-05-07, the docker-compose spec also defines the "pull_policy" property for a service:

version: '3.7'

services:
  my-service:
    image: someimage/somewhere
    pull_policy: always

The docker-compose spec says:

pull_policy defines the decisions Compose implementations will make when it starts to pull images.

Possible values are (tl;dr, check spec for more details):

  • always: always pull
  • never: don't pull (breaks if the image can not be found)
  • missing: pulls if the image is not cached
  • build: always build or rebuild

ASP.NET MVC - passing parameters to the controller

There is another way to accomplish that (described in more details in Stephen Walther's Pager example

Essentially, you create a link in the view:

Html.ActionLink("Next page", "Index", routeData)

In routeData you can specify name/value pairs (e.g., routeData["page"] = 5), and in the controller Index function corresponding parameters receive the value. That is,

public ViewResult Index(int? page)

will have page passed as 5. I have to admit, it's quite unusual that string ("page") automagically becomes a variable - but that's how MVC works in other languages as well...

How can I get a List from some class properties with Java 8 Stream?

You can use map :

List<String> names = 
    personList.stream()
              .map(Person::getName)
              .collect(Collectors.toList());

EDIT :

In order to combine the Lists of friend names, you need to use flatMap :

List<String> friendNames = 
    personList.stream()
              .flatMap(e->e.getFriends().stream())
              .collect(Collectors.toList());

How do I update Homebrew?

  • cd /usr/local
  • git status
  • Discard all the changes (unless you actually want to try to commit to Homebrew - you probably don't)
  • git status til it's clean
  • brew update

SQL Server function to return minimum date (January 1, 1753)

It's not January 1, 1753 but select cast('' as datetime) wich reveals: 1900-01-01 00:00:00.000 gives the default value by SQL server. (Looks more uninitialized to me anyway)

Convert JSONObject to Map

org.json.JSONObject#toMap() will do to work

What is the difference between state and props in React?

From: Andrea Chiarelli book “Beginning React: Simplify your frontend development workflow and enhance the user experience of your applications with React” :

Every React component has a props property. The purpose of this property is to collect data input passed to the component itself. JSX attribute is attached to a React element, a property with the same name is attached to the props object. So, we can access the passed data by using the attached property. In addition, the immutability of props allows us to think of components as pure functions, which are functions that have no side effects (since they don't change their input data). We can think of data passing from one component to another as a unidirectional data flow, from the parent component toward the child components. This gives us a more controllable system.

React provides a mechanism to support the automatic rendering of a component when data changes. Such a mechanism is based on the concept of state. React state is a property that represents data that changes over time. Every component supports the state property, but it should be used carefully. Components that store data that can change over time are said to be stateful components. A stateful component stores the state in the this.state property. To inform a component that the state has changed, you must use the setState() method. State initialization is the only case where you can assign a value to the this.state property without using setState().

setState() merges new data with old data already contained in the state, and overwrites the previous state setState() triggers the execution of the render() method, so you should never call render() explicitly

How to use Redirect in the new react-router-dom of Reactjs

You have to use setState to set a property that will render the <Redirect> inside your render() method.

E.g.

class MyComponent extends React.Component {
  state = {
    redirect: false
  }

  handleSubmit () {
    axios.post(/**/)
      .then(() => this.setState({ redirect: true }));
  }

  render () {
    const { redirect } = this.state;

     if (redirect) {
       return <Redirect to='/somewhere'/>;
     }

     return <RenderYourForm/>;
}

You can also see an example in the official documentation: https://reacttraining.com/react-router/web/example/auth-workflow


That said, I would suggest you to put the API call inside a service or something. Then you could just use the history object to route programatically. This is how the integration with redux works.

But I guess you have your reasons to do it this way.

android : Error converting byte to dex

In my case the problem was because of capital letters in some packages.

Codeigniter displays a blank page instead of error messages

Since none of the solutions seem to be working for you so far, try this one:

ini_set('display_errors', 1);

http://www.php.net/manual/en/errorfunc.configuration.php#ini.display-errors

This explicitly tells PHP to display the errors. Some environments can have this disabled by default.

This is what my environment settings look like in index.php:

/*
 *---------------------------------------------------------------
 * APPLICATION ENVIRONMENT
 *---------------------------------------------------------------
 */
define('ENVIRONMENT', 'development');
/*
 *---------------------------------------------------------------
 * ERROR REPORTING
 *---------------------------------------------------------------
 */
if (defined('ENVIRONMENT'))
{
    switch (ENVIRONMENT)
    {
        case 'development':
            // Report all errors
            error_reporting(E_ALL);

            // Display errors in output
            ini_set('display_errors', 1);
        break;

        case 'testing':
        case 'production':
            // Report all errors except E_NOTICE
            // This is the default value set in php.ini
            error_reporting(E_ALL ^ E_NOTICE);

            // Don't display errors (they can still be logged)
            ini_set('display_errors', 0);
        break;

        default:
            exit('The application environment is not set correctly.');
    }
}

Replacing some characters in a string with another character

Here is a solution with shell parameter expansion that replaces multiple contiguous occurrences with a single _:

$ var=AxxBCyyyDEFzzLMN
$ echo "${var//+([xyz])/_}"
A_BC_DEF_LMN

Notice that the +(pattern) pattern requires extended pattern matching, turned on with

shopt -s extglob

Alternatively, with the -s ("squeeze") option of tr:

$ tr -s xyz _ <<< "$var"
A_BC_DEF_LMN

Loop code for each file in a directory

Try GLOB()

$dir = "/etc/php5/*";  

// Open a known directory, and proceed to read its contents  
foreach(glob($dir) as $file)  
{  
    echo "filename: $file : filetype: " . filetype($file) . "<br />";  
}  

Get first day of week in PHP?

Here's a one liner for the first day of last week, and the last day of last week as a DateTime object.

$firstDay = (new \DateTime())->modify(sprintf('-%d day', date('w') + 7))
                             ->setTime(0, 0, 0);
$lastDay = (new \DateTime())->modify(sprintf('-%d day', date('w') + 1))
                            ->setTime(23, 59, 59);

What is the difference between Normalize.css and Reset CSS?

Normalize.css is mainly a set of styles, based on what its author thought would look good, and make it look consistent across browsers. Reset basically strips styling from elements so you have more control over the styling of everything.

I use both.

Some styles from Reset, some from Normalize.css. For example, from Normalize.css, there's a style to make sure all input elements have the same font, which doesn't occur (between text inputs and textareas). Reset has no such style, so inputs have different fonts, which is not normally wanted.

So bascially, using the two CSS files does a better job 'Equalizing' everything ;)

regards!

How to implement a property in an interface

In the interface, you specify the property:

public interface IResourcePolicy
{
   string Version { get; set; }
}

In the implementing class, you need to implement it:

public class ResourcePolicy : IResourcePolicy
{
   public string Version { get; set; }
}

This looks similar, but it is something completely different. In the interface, there is no code. You just specify that there is a property with a getter and a setter, whatever they will do.

In the class, you actually implement them. The shortest way to do this is using this { get; set; } syntax. The compiler will create a field and generate the getter and setter implementation for it.

How to handle configuration in Go

The JSON format worked for me quite well. The standard library offers methods to write the data structure indented, so it is quite readable.

See also this golang-nuts thread.

The benefits of JSON are that it is fairly simple to parse and human readable/editable while offering semantics for lists and mappings (which can become quite handy), which is not the case with many ini-type config parsers.

Example usage:

conf.json:

{
    "Users": ["UserA","UserB"],
    "Groups": ["GroupA"]
}

Program to read the configuration

import (
    "encoding/json"
    "os"
    "fmt"
)

type Configuration struct {
    Users    []string
    Groups   []string
}

file, _ := os.Open("conf.json")
defer file.Close()
decoder := json.NewDecoder(file)
configuration := Configuration{}
err := decoder.Decode(&configuration)
if err != nil {
  fmt.Println("error:", err)
}
fmt.Println(configuration.Users) // output: [UserA, UserB]

How can I make a list of installed packages in a certain virtualenv?

If you're still a bit confused about virtualenv you might not pick up how to combine the great tips from the answers by Ioannis and Sascha. I.e. this is the basic command you need:

/YOUR_ENV/bin/pip freeze --local

That can be easily used elsewhere. E.g. here is a convenient and complete answer, suited for getting all the local packages installed in all the environments you set up via virtualenvwrapper:

cd ${WORKON_HOME:-~/.virtualenvs}
for dir in *; do [ -d $dir ] && $dir/bin/pip freeze --local >  /tmp/$dir.fl; done
more /tmp/*.fl

Python match a string with regex

The r makes the string a raw string, which doesn't process escape characters (however, since there are none in the string, it is actually not needed here).

Also, re.match matches from the beginning of the string. In other words, it looks for an exact match between the string and the pattern. To match stuff that could be anywhere in the string, use re.search. See a demonstration below:

>>> import re
>>> line = 'This,is,a,sample,string'
>>> re.match("sample", line)
>>> re.search("sample", line)
<_sre.SRE_Match object at 0x021D32C0>
>>>

How do you concatenate Lists in C#?

Concat returns a new sequence without modifying the original list. Try myList1.AddRange(myList2).

How to update all MySQL table rows at the same time?

You can try this,

UPDATE *tableName* SET *field1* = *your_data*, *field2* = *your_data* ... WHERE 1 = 1;

Well in your case if you want to update your online_status to some value, you can try this,

UPDATE thisTable SET online_status = 'Online' WHERE 1 = 1;

Hope it helps. :D

How to implode array with key and value without foreach in PHP

You could use http_build_query, like this:

<?php
  $a=array("item1"=>"object1", "item2"=>"object2");
  echo http_build_query($a,'',', ');
?>

Output:

item1=object1, item2=object2 

Demo

Unable to read data from the transport connection : An existing connection was forcibly closed by the remote host

For me, It was an issue where in the IIS binding it had the IP address of the web server. I changed it to use all unassigned IPs and my application started to work.

Passing parameter to controller action from a Html.ActionLink

You are using the incorrect overload of ActionLink. Try this

<%= Html.ActionLink("Create New Part", "CreateParts", "PartList", new { parentPartId = 0 }, null)%>

How to trigger click event on href element

The native DOM method does the right thing:

$('.cssbuttongo')[0].click();
                  ^
              Important!

This works regardless of whether the href is a URL, a fragment (e.g. #blah) or even a javascript:.

Note that this calls the DOM click method instead of the jQuery click method (which is very incomplete and completely ignores href).

Is there a keyboard shortcut (hotkey) to open Terminal in macOS?

iTerm2 - an alternative to Terminal - has an option to use configurable system-wide hotkey to show/hide (initially set to Alt+Space, disabled by default)

Dynamically add data to a javascript map

Javascript now has a specific built in object called Map, you can call as follows :

   var myMap = new Map()

You can update it with .set :

   myMap.set("key0","value")

This has the advantage of methods you can use to handle look ups, like the boolean .has

  myMap.has("key1"); // evaluates to false 

You can use this before calling .get on your Map object to handle looking up non-existent keys

Setting Timeout Value For .NET Web Service

Try setting the timeout value in your web service proxy class:

WebReference.ProxyClass myProxy = new WebReference.ProxyClass();
myProxy.Timeout = 100000; //in milliseconds, e.g. 100 seconds

I am getting an "Invalid Host header" message when connecting to webpack-dev-server remotely

If you are using create-react-app on C9 just run this command to start

npm run start --public $C9_HOSTNAME

And access the app from whatever your hostname is (eg type $C_HOSTNAME in the terminal to get the hostname)

Angular js init ng-model from default values

This is an obviously lacking, but easily added fix for AngularJS. Just write a quick directive to set the model value from the input field.

<input name="card[description]" value="Visa-4242" ng-model="card.description" ng-initial>

Here's my version:

var app = angular.module('forms', []);

app.directive('ngInitial', function() {
  return {
    restrict: 'A',
    controller: [
      '$scope', '$element', '$attrs', '$parse', function($scope, $element, $attrs, $parse) {
        var getter, setter, val;
        val = $attrs.ngInitial || $attrs.value;
        getter = $parse($attrs.ngModel);
        setter = getter.assign;
        setter($scope, val);
      }
    ]
  };
});

How to generate entire DDL of an Oracle schema (scriptable)?

There is a problem with objects such as PACKAGE_BODY:

SELECT DBMS_METADATA.get_ddl(object_Type, object_name, owner) FROM ALL_OBJECTS WHERE OWNER = 'WEBSERVICE';


ORA-31600 invalid input value PACKAGE BODY parameter OBJECT_TYPE in function GET_DDL
ORA-06512: ??  "SYS.DBMS_METADATA", line 4018
ORA-06512: ??  "SYS.DBMS_METADATA", line 5843
ORA-06512: ??  line 1
31600. 00000 -  "invalid input value %s for parameter %s in function %s"
*Cause:    A NULL or invalid value was supplied for the parameter.
*Action:   Correct the input value and try the call again.



SELECT DBMS_METADATA.GET_DDL(REPLACE(object_type,' ','_'), object_name, owner)
  FROM all_OBJECTS 
  WHERE (OWNER = 'OWNER1');

Can VS Code run on Android?

I don't agree with the accepted answer that the lack of electron prevents VSC on Android.

Electron is really the desktop equivelent of projects like Apache Cordova or Adobe PhoneGap (but Electron is much less efficient and will presumably give way to solutions much closer to Cordova/PhoneGap when possible - it is already being worked on eg. here.)

API's would need to be mapped from their electron equivelents, and many of the plug-ins will have their own issues (but Android is reasonably flexible about allowing stuff like Python compared to iOS) so it is doable.

On the other hand, the demand for an Android version of VSC probably comes from people using the new Chromebooks that support Android, and there is already a solution for ChromeOS using crouton, available here.

Using new line(\n) in string and rendering the same in HTML

I had the following problem where I was fetching data from a database and wanted to display a string containing \n. None of the solutions above worked for me and I finally came up with a solution: https://stackoverflow.com/a/61484190/7251208

Disable Input fields in reactive form

This worked for me: this.form.get('first').disable({onlySelf: true});

How to set the background image of a html 5 canvas to .png image

You can give the background image in css :

#canvas { background:url(example.jpg) }

it will show you canvas back ground image

How to rename files and folder in Amazon S3?

aws s3 cp s3://source_folder/ s3://destination_folder/ --recursive
aws s3 rm s3://source_folder --recursive

How can I exclude all "permission denied" messages from "find"?

Redirect standard error. For instance, if you're using bash on a unix machine, you can redirect standard error to /dev/null like this:

find . 2>/dev/null >files_and_folders

Post request in Laravel - Error - 419 Sorry, your session/ 419 your page has expired

In your Http/Kernel.php

try to comment this line :

\Illuminate\Session\Middleware\AuthenticateSession::class,

in your web middleware array

it might be the root of your issue

Creating a new directory in C

Look at stat for checking if the directory exists,

And mkdir, to create a directory.

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

struct stat st = {0};

if (stat("/some/directory", &st) == -1) {
    mkdir("/some/directory", 0700);
}

You can see the manual of these functions with the man 2 stat and man 2 mkdir commands.

Double array initialization in Java

This is array initializer syntax, and it can only be used on the right-hand-side when declaring a variable of array type. Example:

int[] x = {1,2,3,4};
String y = {"a","b","c"};

If you're not on the RHS of a variable declaration, use an array constructor instead:

int[] x;
x = new int[]{1,2,3,4};
String y;
y = new String[]{"a","b","c"};

These declarations have the exact same effect: a new array is allocated and constructed with the specified contents.

In your case, it might actually be clearer (less repetitive, but a bit less concise) to specify the table programmatically:

double[][] m = new double[4][4];

for(int i=0; i<4; i++) {
    for(int j=0; j<4; j++) {
        m[i][j] = i*j;
    }
}

How to set timeout for a line of c# code

You can use the IAsyncResult and Action class/interface to achieve this.

public void TimeoutExample()
{
    IAsyncResult result;
    Action action = () =>
    {
        // Your code here
    };

    result = action.BeginInvoke(null, null);

    if (result.AsyncWaitHandle.WaitOne(10000))
         Console.WriteLine("Method successful.");
    else
         Console.WriteLine("Method timed out.");
}

How to read values from the querystring with ASP.NET Core?

You can use [FromQuery] to bind a particular model to the querystring:

https://docs.microsoft.com/en-us/aspnet/core/mvc/models/model-binding

e.g.

[HttpGet()]
public IActionResult Get([FromQuery(Name = "page")] string page)
{...}

Using JQuery to open a popup window and print

You should put the print function in your view-details.php file and call it once the file is loaded, by either using

<body onload="window.print()"> 

or

$(document).ready(function () { 
  window.print(); 
});

Disable cache for some images

Let's add another solution one to the bunch.

Adding a unique string at the end is a perfect solution.

example.jpg?646413154

Following solution extends this method and provides both the caching capability and fetch a new version when the image is updated.

When the image is updated, the filemtime will be changed.

<?php
$filename = "path/to/images/example.jpg";
$filemtime = filemtime($filename);
?>

Now output the image:

<img src="images/example.jpg?<?php echo $filemtime; ?>" >

Prevent Default on Form Submit jQuery

Use the new "on" event syntax.

$(document).ready(function() {
  $('form').on('submit', function(e){
    // validation code here
    if(!valid) {
      e.preventDefault();
    }
  });
});

Cite: https://api.jquery.com/on/

Using C++ filestreams (fstream), how can you determine the size of a file?

I'm a novice, but this is my self taught way of doing it:

ifstream input_file("example.txt", ios::in | ios::binary)

streambuf* buf_ptr =  input_file.rdbuf(); //pointer to the stream buffer

input.get(); //extract one char from the stream, to activate the buffer
input.unget(); //put the character back to undo the get()

size_t file_size = buf_ptr->in_avail();
//a value of 0 will be returned if the stream was not activated, per line 3.

How to add CORS request in header in Angular 5

The following worked for me after hours of trying

      $http.post("http://localhost:8080/yourresource", parameter, {headers: 
      {'Content-Type': 'application/json', 'Access-Control-Allow-Origin': '*' } }).

However following code did not work, I am unclear as to why, hopefully someone can improve this answer.

          $http({   method: 'POST', url: "http://localhost:8080/yourresource", 
                    parameter, 
                    headers: {'Content-Type': 'application/json', 
                              'Access-Control-Allow-Origin': '*',
                              'Access-Control-Allow-Methods': 'POST'} 
                })

Can I assume (bool)true == (int)1 for any C++ compiler?

Charles Bailey's answer is correct. The exact wording from the C++ standard is (§4.7/4): "If the source type is bool, the value false is converted to zero and the value true is converted to one."

Edit: I see he's added the reference as well -- I'll delete this shortly, if I don't get distracted and forget...

Edit2: Then again, it is probably worth noting that while the Boolean values themselves always convert to zero or one, a number of functions (especially from the C standard library) return values that are "basically Boolean", but represented as ints that are normally only required to be zero to indicate false or non-zero to indicate true. For example, the is* functions in <ctype.h> only require zero or non-zero, not necessarily zero or one.

If you cast that to bool, zero will convert to false, and non-zero to true (as you'd expect).

Java - Convert integer to string

Integer class has static method toString() - you can use it:

int i = 1234;
String str = Integer.toString(i);

Returns a String object representing the specified integer. The argument is converted to signed decimal representation and returned as a string, exactly as if the argument and radix 10 were given as arguments to the toString(int, int) method.

"Eliminate render-blocking CSS in above-the-fold content"

The 2019 optimal solution for this is HTTP/2 Server Push.

You do not need any hacky javascript solutions or inline styles. However, you do need a server that supports HTTP 2.0 (any modern server version will), which itself requires your server to run SSL. However, with Let's Encrypt there's no reason not to be using SSL anyway.

My site https://r.je/ has a 100/100 score for both mobile and desktop.

The reason for these errors is that the browser gets the HTML, then has to wait for the CSS to be downloaded before the page can be rendered. Using HTTP2 you can send both the HTML and the CSS at the same time.

You can use HTTP/2 push by setting the Link header.

Apache example (.htaccess):

Header add Link "</style.css>; as=style; rel=preload, </font.css>; as=style; rel=preload"

For NGINX you can add the header to your location tag in the server configuration:

location = / {
    add_header Link "</style.css>; as=style; rel=preload, </font.css>; as=style; rel=preload";
}

With this header set, the browser receives the HTML and CSS at the same time which stops the CSS from blocking rendering.

You will want to tweak it so that the CSS is only sent on the first request, but the Link header is the most complete and least hacky solution to "Eliminate Render Blocking Javascript and CSS"

For a detailed discussion, take a look at my post here: Eliminate Render Blocking CSS using HTTP/2 Push

What does if [ $? -eq 0 ] mean for shell scripts?

It's checking the return value ($?) of grep. In this case it's comparing it to 0 (success).

Usually when you see something like this (checking the return value of grep) it's checking to see whether the particular string was detected. Although the redirect to /dev/null isn't necessary, the same thing can be accomplished using -q.

Fixing a systemd service 203/EXEC failure (no such file or directory)

When this happened to me it was because my script had DOS line endings, which always messes up the shebang line at the top of the script. I changed it to Unix line endings and it worked.

Could not install Gradle distribution from 'https://services.gradle.org/distributions/gradle-2.1-all.zip'

I had the same problem. (My problem is with gradle 4.4 files)

Actually the problem is incorrect downloading of 4.4 gradle which already I had. When I delete gradle 4.4 version C:\Users\$Your_User\.gradle\wrapper\dists\gradle-4.4-all

Android studio again downloads gradle-4.4 and syncs with my project.

Now it had rectified with the help of Michelin Man

Thanks for your answer Michelin

node.js, socket.io with SSL

This is my nginx config file and iosocket code. Server(express) is listening on port 9191. It works well: nginx config file:

server {
    listen       443 ssl;
    server_name  localhost;
    root   /usr/share/nginx/html/rdist;

    location /user/ {
        proxy_pass   http://localhost:9191;
    }
    location /api/ {
        proxy_pass   http://localhost:9191;
    }
    location /auth/ {
        proxy_pass   http://localhost:9191;
    }

    location / {
        index  index.html index.htm;
        if (!-e $request_filename){
          rewrite ^(.*)$ /index.html break;
        }
    }
    location /socket.io/ {
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_pass   http://localhost:9191/socket.io/;
    }


    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /usr/share/nginx/html;
    }

    ssl_certificate /etc/nginx/conf.d/sslcert/xxx.pem;
    ssl_certificate_key /etc/nginx/conf.d/sslcert/xxx.key;

}

Server:

const server = require('http').Server(app)
const io = require('socket.io')(server)
io.on('connection', (socket) => {
    handleUserConnect(socket)

  socket.on("disconnect", () => {
   handleUserDisConnect(socket)
  });
})

server.listen(9191, function () {
  console.log('Server listening on port 9191')
})

Client(react):

    const socket = io.connect('', { secure: true, query: `userId=${this.props.user._id}` })

        socket.on('notifications', data => {
            console.log('Get messages from back end:', data)
            this.props.mergeNotifications(data)
        })