Programs & Examples On #Jvlc

JVLC is a project creating Java bindings for libvlc and the popular VLC media player. The project is now mostly dead however and vlcj is a more maintained and better supported alternative.

Is it more efficient to copy a vector by reserving and copying, or by creating and swapping?

Your second example does not work if you send the argument by reference. Did you mean

void copyVecFast(vec<int> original) // no reference
{

  vector<int> new_;
  new_.swap(original); 
}

That would work, but an easier way is

vector<int> new_(original);

How to submit a form on enter when the textarea has focus?

<form id="myform">
    <input type="textbox" id="field"/>
    <input type="button" value="submit">
</form>

<script>
    $(function () {
        $("#field").keyup(function (event) {
            if (event.which === 13) {
                document.myform.submit();
            }
        }
    });
</script>

PPT to PNG with transparent background

One workaround that I have done is:

  • Ctrl + a to select everything in the slide
  • Ctrl + c to copy it
  • open GIMP (probably works in Photoshop or other software)
  • make a new image with a transparent background
  • Ctrl + v to paste all the vectors/text into the image
  • Export the image to a PNG or whatever format

It looks pretty much exactly the same as in Powerpoint, and the vectors/text are very clean with their transparency edges.

Create a directory if it doesn't exist

Probably the easiest and most efficient way is to use boost and the boost::filesystem functions. This way you can build a directory simply and ensure that it is platform independent.

const char* path = _filePath.c_str();
boost::filesystem::path dir(path);
if(boost::filesystem::create_directory(dir))
{
    std::cerr<< "Directory Created: "<<_filePath<<std::endl;
}

boost::filesystem::create_directory - documentation

How to format a UTC date as a `YYYY-MM-DD hh:mm:ss` string using NodeJS?

I am using dateformat at Nodejs and angularjs, so good

install

$ npm install dateformat
$ dateformat --help

demo

var dateFormat = require('dateformat');
var now = new Date();

// Basic usage
dateFormat(now, "dddd, mmmm dS, yyyy, h:MM:ss TT");
// Saturday, June 9th, 2007, 5:46:21 PM

// You can use one of several named masks
dateFormat(now, "isoDateTime");
// 2007-06-09T17:46:21

// ...Or add your own
dateFormat.masks.hammerTime = 'HH:MM! "Can\'t touch this!"';
dateFormat(now, "hammerTime");
// 17:46! Can't touch this!

// You can also provide the date as a string
dateFormat("Jun 9 2007", "fullDate");
// Saturday, June 9, 2007
...

How to delete all files from a specific folder?

You can do it via FileInfo or DirectoryInfo:

DirectoryInfo di = new DirectoryInfo("TempDir");
di.Delete(true);

And then recreate the directory

Why do we use web.xml?

It says all the requests to go through WicketFilter


Also, if you use wicket WicketApplication for application level settings. Like URL patterns and things that are true at app level


This is what you need really, http://wicket.apache.org/learn/examples/helloworld.html

Easiest way to split a string on newlines in .NET?

string[] lines = text.Split(
  Environment.NewLine.ToCharArray(), 
  StringSplitOptions.RemoveEmptyStrings);

The RemoveEmptyStrings option will make sure you don't have empty entries due to \n following a \r

(Edit to reflect comments:) Note that it will also discard genuine empty lines in the text. This is usually what I want but it might not be your requirement.

How do I start my app on startup?

This is how to make an activity start running after android device reboot:

Insert this code in your AndroidManifest.xml file, within the <application> element (not within the <activity> element):

<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

<receiver
    android:enabled="true"
    android:exported="true" 
    android:name="yourpackage.yourActivityRunOnStartup"
    android:permission="android.permission.RECEIVE_BOOT_COMPLETED">

    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED" />
        <action android:name="android.intent.action.QUICKBOOT_POWERON" />
        <category android:name="android.intent.category.DEFAULT" />
    </intent-filter>

</receiver>

Then create a new class yourActivityRunOnStartup (matching the android:name specified for the <receiver> element in the manifest):

package yourpackage;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class yourActivityRunOnStartup extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent.getAction().equals(Intent.ACTION_BOOT_COMPLETED)) {
            Intent i = new Intent(context, MainActivity.class);
            i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            context.startActivity(i);
        }
    }

}

Note: The call i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); is important because the activity is launched from a context outside the activity. Without this, the activity will not start.

Also, the values android:enabled, android:exported and android:permission in the <receiver> tag do not seem mandatory. The app receives the event without these values. See the example here.

Format output string, right alignment

To do it by using f-string and with control of the number of trailing digits:

print(f'A number -> {my_number:>20.5f}')

Jackson - Deserialize using generic class

if you're using scala and know the generic type at compile time, but don't want to manually pass TypeReference everywhere in all your api l ayers, you can use the following code (with jackson 2.9.5):

def read[T](entityStream: InputStream)(implicit typeTag: WeakTypeTag[T]): T = {

    //nathang: all of this *crazy* scala reflection allows us to handle List[Seq[Map[Int,Value]]]] without passing
    // new TypeReference[List[Seq[Map[Int,Value]]]]](){} to the function

    def recursiveFindGenericClasses(t: Type): JavaType = {
      val current = typeTag.mirror.runtimeClass(t)

      if (t.typeArgs.isEmpty) {
        val noSubtypes = Seq.empty[Class[_]]
        factory.constructParametricType(current, noSubtypes:_*)
      }

      else {
        val genericSubtypes: Seq[JavaType] = t.typeArgs.map(recursiveFindGenericClasses)
        factory.constructParametricType(current, genericSubtypes:_*)
      }

    }

    val javaType = recursiveFindGenericClasses(typeTag.tpe)

    json.readValue[T](entityStream, javaType)
  }

which can be used like this:

read[List[Map[Int, SomethingToSerialize]]](inputStream)

String to Binary in C#

It sounds like you basically want to take an ASCII string, or more preferably, a byte[] (as you can encode your string to a byte[] using your preferred encoding mode) into a string of ones and zeros? i.e. 101010010010100100100101001010010100101001010010101000010111101101010

This will do that for you...

//Formats a byte[] into a binary string (010010010010100101010)
public string Format(byte[] data)
{
    //storage for the resulting string
    string result = string.Empty;
    //iterate through the byte[]
    foreach(byte value in data)
    {
        //storage for the individual byte
        string binarybyte = Convert.ToString(value, 2);
        //if the binarybyte is not 8 characters long, its not a proper result
        while(binarybyte.Length < 8)
        {
            //prepend the value with a 0
            binarybyte = "0" + binarybyte;
        }
        //append the binarybyte to the result
        result += binarybyte;
    }
    //return the result
    return result;
}

download a file from Spring boot rest service

The below Sample code worked for me and might help someone.

import org.springframework.core.io.ByteArrayResource;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

@RestController
@RequestMapping("/app")
public class ImageResource {

    private static final String EXTENSION = ".jpg";
    private static final String SERVER_LOCATION = "/server/images";

    @RequestMapping(path = "/download", method = RequestMethod.GET)
    public ResponseEntity<Resource> download(@RequestParam("image") String image) throws IOException {
        File file = new File(SERVER_LOCATION + File.separator + image + EXTENSION);

        HttpHeaders header = new HttpHeaders();
        header.add(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=img.jpg");
        header.add("Cache-Control", "no-cache, no-store, must-revalidate");
        header.add("Pragma", "no-cache");
        header.add("Expires", "0");

        Path path = Paths.get(file.getAbsolutePath());
        ByteArrayResource resource = new ByteArrayResource(Files.readAllBytes(path));

        return ResponseEntity.ok()
                .headers(header)
                .contentLength(file.length())
                .contentType(MediaType.parseMediaType("application/octet-stream"))
                .body(resource);
    }

}

How to access static resources when mapping a global front controller servlet on /*

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">
<mvc:default-servlet-handler/>
</beans>

and if you want to use annotation based configuration use below code

@Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }

Error : No resource found that matches the given name (at 'icon' with value '@drawable/icon')

if cordova app copy a valid png file to

resources\android\icon.png

and then run

ionic resources --icon

How do I create a comma-separated list using a SQL query?

To be agnostic, drop back and punt.

Select a.name as a_name, r.name as r_name
  from ApplicationsResource ar, Applications a, Resources r
 where a.id = ar.app_id
   and r.id = ar.resource_id
 order by r.name, a.name;

Now user your server programming language to concatenate a_names while r_name is the same as the last time.

How do I generate sourcemaps when using babel and webpack?

Even same issue I faced, in browser it was showing compiled code. I have made below changes in webpack config file and it is working fine now.

 devtool: '#inline-source-map',
 debug: true,

and in loaders I kept babel-loader as first option

loaders: [
  {
    loader: "babel-loader",
    include: [path.resolve(__dirname, "src")]
  },
  { test: /\.js$/, exclude: [/app\/lib/, /node_modules/], loader: 'ng-annotate!babel' },
  { test: /\.html$/, loader: 'raw' },
  {
    test: /\.(jpe?g|png|gif|svg)$/i,
    loaders: [
      'file?hash=sha512&digest=hex&name=[hash].[ext]',
      'image-webpack?bypassOnDebug&optimizationLevel=7&interlaced=false'
    ]
  },
  {test: /\.less$/, loader: "style!css!less"},
  { test: /\.styl$/, loader: 'style!css!stylus' },
  { test: /\.css$/, loader: 'style!css' }
]

Unrecognized attribute 'targetFramework'. Note that attribute names are case-sensitive

Just Remove the "Target Framework 4.0" and close the bracket.

It will Work

The thread has exited with code 0 (0x0) with no unhandled exception

Stop this error you have to follow this simple steps

  1. Open Visual Studio
  2. Select option debug from the top
  3. Select Options
  4. In Option Select debugging under debugging select General
  5. In General Select check box "Automatically close the console when debugging stop"
  6. Save it

Then Run the code by using Shortcut key Ctrl+f5

**Other wise it still show error when you run it direct

How can I get the DateTime for the start of the week?

try with this in c#.With this code you can get both first date and last date of a given week.Here Sunday is the first day and Saturday is the last day but you can set both day's according to your culture

DateTime firstDate = GetFirstDateOfWeek(DateTime.Parse("05/09/2012").Date,DayOfWeek.Sunday);
DateTime lastDate = GetLastDateOfWeek(DateTime.Parse("05/09/2012").Date, DayOfWeek.Saturday);

public static DateTime GetFirstDateOfWeek(DateTime dayInWeek, DayOfWeek firstDay)
{
    DateTime firstDayInWeek = dayInWeek.Date;
    while (firstDayInWeek.DayOfWeek != firstDay)
        firstDayInWeek = firstDayInWeek.AddDays(-1);

    return firstDayInWeek;
}
public static DateTime GetLastDateOfWeek(DateTime dayInWeek, DayOfWeek firstDay)
{
    DateTime lastDayInWeek = dayInWeek.Date;
    while (lastDayInWeek.DayOfWeek != firstDay)
        lastDayInWeek = lastDayInWeek.AddDays(1);

    return lastDayInWeek;
}

using wildcards in LDAP search filters/queries

This should work, at least according to the Search Filter Syntax article on MSDN network.

The "hang-up" you have noticed is probably just a delay. Try running the same query with narrower scope (for example the specific OU where the test object is located), as it may take very long time for processing if you run it against all AD objects.

You may also try separating the filter into two parts:

(|(displayName=*searchstring)(displayName=searchstring*))

Handling JSON Post Request in Go

Please use json.Decoder instead of json.Unmarshal.

func test(rw http.ResponseWriter, req *http.Request) {
    decoder := json.NewDecoder(req.Body)
    var t test_struct
    err := decoder.Decode(&t)
    if err != nil {
        panic(err)
    }
    log.Println(t.Test)
}

Frame Buster Buster ... buster code needed

After pondering this for a little while, I believe this will show them who's boss...

if(top != self) {
  window.open(location.href, '_top');
}

Using _top as the target parameter for window.open() will launch it in the same window.

Runtime vs. Compile time

Translation of source code into stuff-happening-on-the-[screen|disk|network] can occur in (roughly) two ways; call them compiling and interpreting.

In a compiled program (examples are c and fortran):

  1. The source code is fed into another program (usually called a compiler--go figure), which produces an executable program (or an error).
  2. The executable is run (by double clicking it, or typing it's name on the command line)

Things that happen in the first step are said to happen at "compile time", things that happen in the second step are said to happen at "run time".

In an interpreted program (example MicroSoft basic (on dos) and python (I think)):

  1. The source code is fed into another program (usually called an interpreter) which "runs" it directly. Here the interpreter serves as an intermediate layer between your program and the operating system (or the hardware in really simple computers).

In this case the difference between compile time and run time is rather harder to pin down, and much less relevant to the programmer or user.

Java is a sort of hybrid, where the code is compiled to bytecode, which then runs on a virtual machine which is usually an interpreter for the bytecode.

There is also an intermediate case in which the program is compiled to bytecode and run immediately (as in awk or perl).

Java default constructor

A default constructor is automatically generated by the compiler if you do not explicitly define at least one constructor in your class. You've defined two, so your class does not have a default constructor.

Per The Java Language Specification Third Edition:

8.8.9 Default Constructor

If a class contains no constructor declarations, then a default constructor that takes no parameters is automatically provided...

List of enum values in java

This is a more generic solution, that can be use for any Enum object, so be free of used.

static public List<Object> constFromEnumToList(Class enumType) {
    List<Object> nueva = new ArrayList<Object>();
    if (enumType.isEnum()) {
        try {
            Class<?> cls = Class.forName(enumType.getCanonicalName());
            Object[] consts = cls.getEnumConstants();
            nueva.addAll(Arrays.asList(consts));
        } catch (ClassNotFoundException e) {
            System.out.println("No se localizo la clase");
        }
    }
    return nueva;
}

Now you must call this way:

constFromEnumToList(MiEnum.class);

Find all stored procedures that reference a specific column in some table

You can use ApexSQL Search, it's a free SSMS and Visual Studio add-in and it can list all objects that reference a specific table column. It can also find data stored in tables and views. You can easily filter the results to show a specific database object type that references the column

enter image description here

Disclaimer: I work for ApexSQL as a Support Engineer

Better way to get type of a Javascript variable?

I guess the most universal solution here - is to check for undefined and null first, then just call constructor.name.toLowerCase().

const getType = v =>
  v === undefined
    ? 'undefined'
    : v === null
      ? 'null'
      : v.constructor.name.toLowerCase();




console.log(getType(undefined)); // 'undefined'
console.log(getType(null)); // 'null'
console.log(getType('')); // 'string'
console.log(getType([])); // 'array'
console.log(getType({})); // 'object'
console.log(getType(new Set())); // `set'
console.log(getType(Promise.resolve())); // `promise'
console.log(getType(new Map())); // `map'

How to get a context in a recycler view adapter

You can define:

Context ctx; 

And on onCreate initialise ctx to:

ctx=parent.getContext(); 

Note: Parent is a ViewGroup.

Fatal error: iostream: No such file or directory in compiling C program using GCC

Seems like you posted a new question after you realized that you were dealing with a simpler problem related to size_t. I am glad that you did.

Anyways, You have a .c source file, and most of the code looks as per C standards, except that #include <iostream> and using namespace std;

C equivalent for the built-in functions of C++ standard #include<iostream> can be availed through #include<stdio.h>

  1. Replace #include <iostream> with #include <stdio.h>, delete using namespace std;
  2. With #include <iostream> taken off, you would need a C standard alternative for cout << endl;, which can be done by printf("\n"); or putchar('\n');
    Out of the two options, printf("\n"); works the faster as I observed.

    When used printf("\n"); in the code above in place of cout<<endl;

    $ time ./thread.exe
    1 2 3 4 5 6 7 8 9 10
    
    real    0m0.031s
    user    0m0.030s
    sys     0m0.030s
    

    When used putchar('\n'); in the code above in place of cout<<endl;

    $ time ./thread.exe
    1 2 3 4 5 6 7 8 9 10
    
    real    0m0.047s
    user    0m0.030s
    sys     0m0.030s
    

Compiled with Cygwin gcc (GCC) 4.8.3 version. results averaged over 10 samples. (Took me 15 mins)

How do I get the AM/PM value from a DateTime?

Something like bool isPM = GetHour() > 11. But if you want to format a date to a string, you shouldn't need to do this yourself. Use the date formatting functions for that.

How to deserialize JS date using Jackson?

There is a good blog about this topic: http://www.baeldung.com/jackson-serialize-dates Use @JsonFormat looks the most simple way.

public class Event {
    public String name;

    @JsonFormat
      (shape = JsonFormat.Shape.STRING, pattern = "dd-MM-yyyy hh:mm:ss")
    public Date eventDate;
}

SET NOCOUNT ON usage

Ok now I've done my research, here is the deal:

In TDS protocol, SET NOCOUNT ON only saves 9-bytes per query while the text "SET NOCOUNT ON" itself is a whopping 14 bytes. I used to think that 123 row(s) affected was returned from server in plain text in a separate network packet but that's not the case. It's in fact a small structure called DONE_IN_PROC embedded in the response. It's not a separate network packet so no roundtrips are wasted.

I think you can stick to default counting behavior almost always without worrying about the performance. There are some cases though, where calculating the number of rows beforehand would impact the performance, such as a forward-only cursor. In that case NOCOUNT might be a necessity. Other than that, there is absolutely no need to follow "use NOCOUNT wherever possible" motto.

Here is a very detailed analysis about insignificance of SET NOCOUNT setting: http://daleburnett.com/2014/01/everything-ever-wanted-know-set-nocount/

How to run a function in jquery

The following should work nicely.

$(function() {

  // Way 1
  function doosomething()
  {
    //Doo something
  }

  // Way 2, equivalent to Way 1
  var doosomething = function() {
    // Doo something
  }

  $("div.class").click(doosomething);

  $("div.secondclass").click(doosomething);

});

Basically, you are declaring your function in the same scope as your are using it (JavaScript uses Closures to determine scope).

Now, since functions in JavaScript behave like any other object, you can simply assign doosomething as the function to call on click by using .click(doosomething);

Your function will not execute until you call it using doosomething() (doosomething without the () refers to the function but doesn't call it) or another function calls in (in this case, the click handler).

Where is the WPF Numeric UpDown control?

Use VerticalScrollBar with the TextBlock control in WPF. In your code behind, add the following code:

In the constructor, define an event handler for the scrollbar:

scrollBar1.ValueChanged += new RoutedPropertyChangedEventHandler<double>(scrollBar1_ValueChanged);
scrollBar1.Minimum = 0;
scrollBar1.Maximum = 1;
scrollBar1.SmallChange = 0.1;

Then in the event handler, add:

void scrollBar1_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
{
    FteHolderText.Text = scrollBar1.Value.ToString();
}

Here is the original snippet from my code... make necessary changes.. :)

public NewProjectPlan()
{
    InitializeComponent();

    this.Loaded += new RoutedEventHandler(NewProjectPlan_Loaded);

    scrollBar1.ValueChanged += new RoutedPropertyChangedEventHandler<double>(scrollBar1_ValueChanged);
    scrollBar1.Minimum = 0;
    scrollBar1.Maximum = 1;
    scrollBar1.SmallChange = 0.1;

    // etc...
}

void scrollBar1_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
{
    FteHolderText.Text = scrollBar1.Value.ToString();
}

How to solve "java.io.IOException: error=12, Cannot allocate memory" calling Runtime#exec()?

I solved this using JNA: https://github.com/twall/jna

import com.sun.jna.Library;
import com.sun.jna.Native;
import com.sun.jna.Platform;

public class prova {

    private interface CLibrary extends Library {
        CLibrary INSTANCE = (CLibrary) Native.loadLibrary((Platform.isWindows() ? "msvcrt" : "c"), CLibrary.class);
        int system(String cmd);
    }

    private static int exec(String command) {
        return CLibrary.INSTANCE.system(command);
    }

    public static void main(String[] args) {
        exec("ls");
    }
}

INSERT INTO vs SELECT INTO

  1. Which statement is preferable? Depends on what you are doing.

  2. Are there other performance implications? If the table is a permanent table, you can create indexes at the time of table creation which has implications for performance both negatively and positiviely. Select into does not recreate indexes that exist on current tables and thus subsequent use of the table may be slower than it needs to be.

  3. What is a good use case for SELECT...INTO over INSERT INTO ...? Select into is used if you may not know the table structure in advance. It is faster to write than create table and an insert statement, so it is used to speed up develoment at times. It is often faster to use when you are creating a quick temp table to test things or a backup table of a specific query (maybe records you are going to delete). It should be rare to see it used in production code that will run multiple times (except for temp tables) because it will fail if the table was already in existence.

It is sometimes used inappropriately by people who don't know what they are doing. And they can cause havoc in the db as a result. I strongly feel it is inappropriate to use SELECT INTO for anything other than a throwaway table (a temporary backup, a temp table that will go away at the end of the stored proc ,etc.). Permanent tables need real thought as to their design and SELECT INTO makes it easy to avoid thinking about anything even as basic as what columns and what datatypes.

In general, I prefer the use of the create table and insert statement - you have more controls and it is better for repeatable processes. Further, if the table is a permanent table, it should be created from a separate create table script (one that is in source control) as creating permanent objects should not, in general, in code are inserts/deletes/updates or selects from a table. Object changes should be handled separately from data changes because objects have implications beyond the needs of a specific insert/update/select/delete. You need to consider the best data types, think about FK constraints, PKs and other constraints, consider auditing requirements, think about indexing, etc.

What is the difference between a web API and a web service?

In the context of ASP.Net a Web API is a Controller whose base class is ApiController and does not use Views. A Web Service is a class derived from WebService and has automatic WSDL generation. By default it is a SOAP api, but you can also use JSON by adding a ScriptServiceAttribute.

What is a good regular expression to match a URL?

These are the droids you're looking for. This is taken from validator.js which is the library you should really use to do this. But if you want to roll your own, who am I to stop you? If you want pure regex then you can just take out the length check. I think it's a good idea to test the length of the URL though if you really want to determine compliance with the spec.

 function isURL(str) {
     var urlRegex = '^(?!mailto:)(?:(?:http|https|ftp)://)(?:\\S+(?::\\S*)?@)?(?:(?:(?:[1-9]\\d?|1\\d\\d|2[01]\\d|22[0-3])(?:\\.(?:1?\\d{1,2}|2[0-4]\\d|25[0-5])){2}(?:\\.(?:[0-9]\\d?|1\\d\\d|2[0-4]\\d|25[0-4]))|(?:(?:[a-z\\u00a1-\\uffff0-9]+-?)*[a-z\\u00a1-\\uffff0-9]+)(?:\\.(?:[a-z\\u00a1-\\uffff0-9]+-?)*[a-z\\u00a1-\\uffff0-9]+)*(?:\\.(?:[a-z\\u00a1-\\uffff]{2,})))|localhost)(?::\\d{2,5})?(?:(/|\\?|#)[^\\s]*)?$';
     var url = new RegExp(urlRegex, 'i');
     return str.length < 2083 && url.test(str);
}

In C#, why is String a reference type that behaves like a value type?

At the risk of getting yet another mysterious down-vote...the fact that many mention the stack and memory with respect to value types and primitive types is because they must fit into a register in the microprocessor. You cannot push or pop something to/from the stack if it takes more bits than a register has....the instructions are, for example "pop eax" -- because eax is 32 bits wide on a 32-bit system.

Floating-point primitive types are handled by the FPU, which is 80 bits wide.

This was all decided long before there was an OOP language to obfuscate the definition of primitive type and I assume that value type is a term that has been created specifically for OOP languages.

javax.validation.ValidationException: HV000183: Unable to load 'javax.el.ExpressionFactory'

In case you don't need javax.el (for example in a JavaSE application), use ParameterMessageInterpolator from Hibernate validator. Hibernate validator is a standalone component, which can be used without Hibernate itself.

Depend on hibernate-validator

<dependency>
   <groupId>org.hibernate</groupId>
   <artifactId>hibernate-validator</artifactId>
   <version>6.0.16.Final</version>
</dependency>

Use ParameterMessageInterpolator

import javax.validation.Validation;
import javax.validation.Validator;
import org.hibernate.validator.messageinterpolation.ParameterMessageInterpolator;

private static final Validator VALIDATOR =
  Validation.byDefaultProvider()
    .configure()
    .messageInterpolator(new ParameterMessageInterpolator())
    .buildValidatorFactory()
    .getValidator();

Parsing boolean values with argparse

just do the following , you can make --test = True by using

python filename --test

parser.add_argument("--test" , default=False ,help="test ?", dest='test', action='store_true')

How to pass parameter to click event in Jquery

As DOC says, you can pass data to the handler as next:

// say your selector and click handler looks something like this...
$("some selector").on('click',{param1: "Hello", param2: "World"}, cool_function);

// in your function, just grab the event object and go crazy...
function cool_function(event){
    alert(event.data.param1);
    alert(event.data.param2);

    // access element's id where click occur
    alert( event.target.id ); 
}

Datatable select with multiple conditions

Dim dr As DataRow()


dr = dt.Select("A="& a & "and B="& b & "and C=" & c,"A",DataViewRowState.CurrentRows)

Where A,B,C are the column names where second parameter is for sort expression

How to have a a razor action link open in a new tab?

For

@Url.Action

<a href="@Url.Action("Action", "Controller")" target="_blank">Link Text</a>

static files with express.js

use below inside your app.js

app.use(express.static('folderName'));

(folderName is folder which has files) - remember these assets are accessed direct through server path (i.e. http://localhost:3000/abc.png (where as abc.png is inside folderName folder)

Class Not Found: Empty Test Suite in IntelliJ

This might also happen, if your test folder has been imported as a separate module (a small square is shown on the folder icon in the project view).
Remove the module by selecting the test folder in the project view and press DEL.
Then start your test.
If a popup dialog appears with an error message, that no module is selected, specify your root module from the dropdown.

What is a semaphore?

A semaphore is a way to lock a resource so that it is guaranteed that while a piece of code is executed, only this piece of code has access to that resource. This keeps two threads from concurrently accesing a resource, which can cause problems.

R: how to label the x-axis of a boxplot

If you read the help file for ?boxplot, you'll see there is a names= parameter.

     boxplot(apple, banana, watermelon, names=c("apple","banana","watermelon"))

enter image description here

retrieve links from web page using python and BeautifulSoup

There can be many duplicate links together with both external and internal links. To differentiate between the two and just get unique links using sets:

# Python 3.
import urllib    
from bs4 import BeautifulSoup

url = "http://www.espncricinfo.com/"
resp = urllib.request.urlopen(url)
# Get server encoding per recommendation of Martijn Pieters.
soup = BeautifulSoup(resp, from_encoding=resp.info().get_param('charset'))  
external_links = set()
internal_links = set()
for line in soup.find_all('a'):
    link = line.get('href')
    if not link:
        continue
    if link.startswith('http'):
        external_links.add(link)
    else:
        internal_links.add(link)

# Depending on usage, full internal links may be preferred.
full_internal_links = {
    urllib.parse.urljoin(url, internal_link) 
    for internal_link in internal_links
}

# Print all unique external and full internal links.
for link in external_links.union(full_internal_links):
    print(link)

iOS for VirtualBox

VirtualBox is a virtualizer, not an emulator. (The name kinda gives it away.) I.e. it can only virtualize a CPU that is actually there, not emulate one that isn't. In particular, VirtualBox can only virtualize x86 and AMD64 CPUs. iOS only runs on ARM CPUs.

get original element from ng-click

You need $event.currentTarget instead of $event.target.

How do I extract the contents of an rpm?

7-Zip is able to extract the contents. It works the same way that a tar.gz file works. A compressed file inside a compressed file.

On Windows 7 Pro with 7-Zip installed:

Right click the rpm file. Mouse over 7-Zip in the context menu. Select extract to "filename".

Enter into the filename folder.

Right click the cpio file. Mouse over 7-Zip in the context menu. Select extract to "filename".

You are done. The folder with "filename" contains the extracted contents for inspecting.

I know you Linux guys despise things being made easy, but in the long run, if you have to spend time hunting down a solution to a simple problem like this; that inefficiency is costing you money.

Given the fact that you Linux guys despise efficient simplicity, I highly doubt that the Linux version of 7-Zip will do the same thing in the exact same way.

Why make it easy when you can make downright stupid hard and claim to be a genius at the same time?

Just to be clear; I'm not a Windows fanboy. I'm actually looking into moving over to Linux. I just couldn't resist the opportunity to rub what Windows developers would see as common sense, best developer practices into your faces.

Just be glad it's me posting this and you don't have Mark Harmon standing next to you cause; Special agent Leroy Jethro Gibbs would have done given you a head slap for not using your head.

I don't know which Gibbs rule it is but the rule is: Don't make things harder for yourself than they have to be.

Now we get to see who needs to take a vacation. Take care!

How to set environment variables in PyCharm?

I was able to figure out this using a PyCharm plugin called EnvFile. This plugin, basically allows setting environment variables to run configurations from one or multiple files.

The installation is pretty simple:

Preferences > Plugins > Browse repositories... > Search for "Env File" > Install Plugin.

Then, I created a file, in my project root, called environment.env which contains:

DATABASE_URL=postgres://127.0.0.1:5432/my_db_name
DEBUG=1

Then I went to Run->Edit Configurations, and I followed the steps in the next image:

Set Environment Variables

In 3, I chose the file environment.env, and then I could just click the play button in PyCharm, and everything worked like a charm.

How to grep and replace

Usually not with grep, but rather with sed -i 's/string_to_find/another_string/g' or perl -i.bak -pe 's/string_to_find/another_string/g'.

C# How can I check if a URL exists/is valid?

WebRequest request = WebRequest.Create("http://www.google.com");
try
{
     request.GetResponse();
}
catch //If exception thrown then couldn't get response from address
{
     MessageBox.Show("The URL is incorrect");`
}

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

I tried ComboBox1_KeyPress but it allows to delete the character & you can also use copy paste command. My DropDownStyle is set to DropDownList but still no use. So I did below step to avoid combobox text editing.

  • Below code handles delete & backspace key. And also disables combination with control key (e.g. ctr+C or ctr+X)

     Private Sub CmbxInType_KeyDown(sender As Object, e As KeyEventArgs) Handles CmbxInType.KeyDown
        If e.KeyCode = Keys.Delete Or e.KeyCode = Keys.Back Then 
            e.SuppressKeyPress = True
        End If
    
        If Not (e.Control AndAlso e.KeyCode = Keys.C) Then
            e.SuppressKeyPress = True
        End If
    End Sub
    
  • In form load use below line to disable right click on combobox control to avoid cut/paste via mouse click.

    CmbxInType.ContextMenu = new ContextMenu()
    

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

I think we can access the socket object from the server, and you can assign the nickname, and point its socket id,

io.sockets.on('connection',function(socket){ 
    io.sockets.sockets['nickname'] = socket.id;
    client.on("chat", function(data) {      
        var sock_id = io.sockets.sockets['nickname']
        io.sockets.sockets[sock_id].emit("private", "message");
    });    
});

On disconnect please remove the nickname from io.sockets.sockets.

How to enable or disable an anchor using jQuery?

It's as simple as return false;

ex.

jQuery("li a:eq(0)").click(function(){
   return false;
})

or

jQuery("#menu a").click(function(){
   return false;
})

How to access the local Django webserver from outside world

I'm going to add this here:

  1. sudo python manage.py runserver 80

  2. Go to your phone or computer and enter your computers internal IP (e.g 192.168.0.12) into the browser.

At this point you should be connected to the Django server.

This should also work without sudo:

python manage.py runserver 0.0.0.0:8000

Java "lambda expressions not supported at this language level"

Ctrl + Alt + Shift + S and then from project select the language level 1.8, read more about Lambda Expressions here

Show a number to two decimal places

For conditional rounding off ie. show decimal where it's really needed otherwise whole number

123.56 => 12.56

123.00 => 123

$somenumber = 123.56;

$somenumber = round($somenumber,2);

if($somenumber == intval($somenumber))
{
    $somenumber = intval($somenumber);
}

echo $somenumber; // 123.56


$somenumber = 123.00;

$somenumber = round($somenumber,2);

if($somenumber == intval($somenumber))
{
    $somenumber = intval($somenumber);
}

echo $somenumber; // 123    

Angular - POST uploaded file

In my project , I use the XMLHttpRequest to send multipart/form-data. I think it will fit you to.

and the uploader code

let xhr = new XMLHttpRequest();
xhr.open('POST', 'http://www.example.com/rest/api', true);
xhr.withCredentials = true;
xhr.send(formData);

Here is example : https://github.com/wangzilong/angular2-multipartForm

How to decorate a class?

I would second the notion that you may wish to consider a subclass instead of the approach you've outlined. However, not knowing your specific scenario, YMMV :-)

What you're thinking of is a metaclass. The __new__ function in a metaclass is passed the full proposed definition of the class, which it can then rewrite before the class is created. You can, at that time, sub out the constructor for a new one.

Example:

def substitute_init(self, id, *args, **kwargs):
    pass

class FooMeta(type):

    def __new__(cls, name, bases, attrs):
        attrs['__init__'] = substitute_init
        return super(FooMeta, cls).__new__(cls, name, bases, attrs)

class Foo(object):

    __metaclass__ = FooMeta

    def __init__(self, value1):
        pass

Replacing the constructor is perhaps a bit dramatic, but the language does provide support for this kind of deep introspection and dynamic modification.

LDAP server which is my base dn

The base dn is dc=example,dc=com.

I don't know about openca, but I will try this answer since you got very little traffic so far.

A base dn is the point from where a server will search for users. So I would try to simply use admin as a login name.

If openca behaves like most ldap aware applications, this is what is going to happen :

  1. An ldap search for the user admin will be done by the server starting at the base dn (dc=example,dc=com).
  2. When the user is found, the full dn (cn=admin,dc=example,dc=com) will be used to bind with the supplied password.
  3. The ldap server will hash the password and compare with the stored hash value. If it matches, you're in.

Getting step 1 right is the hardest part, but mostly because we don't get to do it often. Things you have to look out for in your configuraiton file are :

  • The dn your application will use to bind to the ldap server. This happens at application startup, before any user comes to authenticate. You will have to supply a full dn, maybe something like cn=admin,dc=example,dc=com.
  • The authentication method. It is usually a "simple bind".
  • The user search filter. Look at the attribute named objectClass for your admin user. It will be either inetOrgPerson or user. There will be others like top, you can ignore them. In your openca configuration, there should be a string like (objectClass=inetOrgPerson). Whatever it is, make sure it matches your admin user's object Class. You can specify two object class with this search filter (|(objectClass=inetOrgPerson)(objectClass=user)).

Download an LDAP Browser, such as Apache's Directory Studio. Connect using your application's credentials, so you will see what your application sees.

Entity Framework: table without primary key

I`m very happy my problem is solved.

Unable to update the EntitySet - because it has a DefiningQuery and no <UpdateFunction> element exist

and do this : Look below that line and find the tag. It will have a big ol' select statement in it. Remove the tag and it's contents..

now without changing DB T I can insert to a table which has not PK

thanks all and thank Pharylon

how to stop Javascript forEach?

    var f = "how to stop Javascript forEach?".split(' ');
    f.forEach(function (a,b){
        console.info(b+1);
        if (a == 'stop') {
            console.warn("\tposition: \'stop\'["+(b+1)+"] \r\n\tall length: " + (f.length)); 
            f.length = 0; //<--!!!
        }
    });

What are intent-filters in Android?

First change the xml, mark your second activity as DEFAULT

<activity android:name=".AddNewActivity" android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
    </activity>

Now you can initiate this activity using StartActivity method.

How to sum all column values in multi-dimensional array?

You can try this:

$c = array_map(function () {
      return array_sum(func_get_args());
     },$a, $b);

and finally:

print_r($c);

HTML Script tag: type or language (or omit both)?

HTML4/XHTML1 requires

<script type="...">...</script>

HTML5 faces the fact that there is only one scripting language on the web, and allows

<script>...</script>

The latter works in any browser that supports scripting (NN2+).

Bootstrap 3: pull-right for col-lg only

.pull-right-not-xs, .pull-right-not-sm, .pull-right-not-md, .pull-right-not-lg{
    float: right;
}

.pull-left-not-xs, .pull-left-not-sm, .pull-left-not-md, .pull-left-not-lg{
    float: left;
}
@media (max-width: 767px) {    
    .pull-right-not-xs, .pull-left-not-xs{
        float: none;
    }
    .pull-right-xs {
        float: right;
    }
    .pull-left-xs {
        float: left;
    }
}
@media (min-width: 768px) and (max-width: 991px) {
    .pull-right-not-sm, .pull-left-not-sm{
        float: none;
    }
    .pull-right-sm {
        float: right;
    }
    .pull-left-sm {
        float: left;
    }
}
@media (min-width: 992px) and (max-width: 1199px) {
    .pull-right-not-md, .pull-left-not-md{
        float: none;
    }
    .pull-right-md {
        float: right;
    }
    .pull-left-md {
        float: left;
    }
}
@media (min-width: 1200px) {
    .pull-right-not-lg, .pull-left-not-lg{
        float: none;
    }
    .pull-right-lg {
        float: right;
    }
    .pull-left-lg {
        float: left;
    }
}

Check if an array contains any element of another array in JavaScript

Personally, I would use the following function:

var arrayContains = function(array, toMatch) {
    var arrayAsString = array.toString();
    return (arrayAsString.indexOf(','+toMatch+',') >-1);
}

The "toString()" method will always use commas to separate the values. Will only really work with primitive types.

How to set dropdown arrow in spinner?

copy and paste this xml instead of your xml

<?xml version="1.0" encoding="UTF-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/back1"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <LinearLayout
        android:id="@+id/linearLayout1"
        android:layout_width="wrap_content"
        android:layout_height="55dp"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="20dp" 
        android:background="@drawable/red">

        <Spinner
            android:id="@+id/spinner1"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:dropDownWidth="fill_parent" 
            android:background="@android:drawable/btn_dropdown"
         />

    </LinearLayout>

    <EditText
        android:id="@+id/editText1"
        android:layout_width="wrap_content"
        android:layout_height="55dp"
        android:layout_alignLeft="@+id/linearLayout1"
        android:layout_alignRight="@+id/linearLayout1"
        android:layout_below="@+id/linearLayout1"
        android:layout_marginTop="25dp"
        android:background="@drawable/red"
        android:ems="10"
        android:hint="enter card number" >

        <requestFocus />
    </EditText>

    <LinearLayout
        android:id="@+id/linearLayout2"
        android:layout_width="wrap_content"
        android:layout_height="55dp"
        android:layout_alignLeft="@+id/editText1"
        android:layout_alignRight="@+id/editText1"
        android:layout_below="@+id/editText1"
        android:layout_marginTop="33dp"
        android:orientation="horizontal" 
        android:background="@drawable/red">

        <Spinner
            android:id="@+id/spinner3"
            android:layout_width="72dp"
            android:layout_height="wrap_content"
            android:background="@android:drawable/btn_dropdown"
             />

        <Spinner
            android:id="@+id/spinner2"
            android:layout_width="72dp"
            android:layout_height="wrap_content" 
            android:background="@android:drawable/btn_dropdown"
            />

        <EditText
            android:id="@+id/editText2"
            android:layout_width="22dp"
            android:layout_height="match_parent"
            android:layout_weight="0.18"
            android:ems="10"
            android:hint="enter cvv" />

    </LinearLayout>

    <LinearLayout
        android:id="@+id/linearLayout3"
        android:layout_width="wrap_content"
        android:layout_height="55dp"
        android:layout_alignParentLeft="true"
        android:layout_alignRight="@+id/linearLayout2"
        android:layout_below="@+id/linearLayout2"
        android:layout_marginTop="26dp"
        android:orientation="vertical"
        android:background="@drawable/red" >
    </LinearLayout>

    <Spinner
        android:id="@+id/spinner4"
        android:layout_width="15dp"
        android:layout_height="18dp"
        android:layout_alignBottom="@+id/linearLayout3"
        android:layout_alignLeft="@+id/linearLayout3"
        android:layout_alignRight="@+id/linearLayout3"
        android:layout_alignTop="@+id/linearLayout3"
        android:background="@android:drawable/btn_dropdown"
      />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/linearLayout3"
        android:layout_marginTop="18dp"
        android:text="Add Amount" 
        android:background="@drawable/buttonsty"/>
</RelativeLayout>

python xlrd unsupported format, or corrupt file.

I know there should be a proper way to solve it but just to save time

I uploaded my xlsx sheet to Google Sheets and then again downloaded it from Google Sheets it working now

If you don't have time to solve the problem, you can try this

Terminal Multiplexer for Microsoft Windows - Installers for GNU Screen or tmux

Adding to the thread, there's a new console in town called babun, im running tmux in it without a problem. lets you run bash or the zsh.

click here for github

bootstrap jquery show.bs.modal event won't fire

This happens when code might been executed before and it's not showing up so you can add timeout() for it tp fire.

$(document).on('shown.bs.modal', function (event) {
      setTimeout(function(){
        alert("Hi");
      },1000); 
    });

Enable ASP.NET ASMX web service for HTTP POST / GET requests

Try to declare UseHttpGet over your method.

[ScriptMethod(UseHttpGet = true)]
public string HelloWorld()
{
    return "Hello World";
}

How to convert JSON to XML or XML to JSON?

Thanks for David Brown's answer. In my case of JSON.Net 3.5, the convert methods are under the JsonConvert static class:

XmlNode myXmlNode = JsonConvert.DeserializeXmlNode(myJsonString); // is node not note
// or .DeserilizeXmlNode(myJsonString, "root"); // if myJsonString does not have a root
string jsonString = JsonConvert.SerializeXmlNode(myXmlNode);

How to find and return a duplicate value in array

If you are comparing two different arrays (instead of one against itself) a very fast way is to use the intersect operator & provided by Ruby's Array class.

# Given
a = ['a', 'b', 'c', 'd']
b = ['e', 'f', 'c', 'd']

# Then this...
a & b # => ['c', 'd']

How to interactively (visually) resolve conflicts in SourceTree / git

From SourceTree, click on Tools->Options. Then on the "General" tab, make sure to check the box to allow SourceTree to modify your Git config files.

Then switch to the "Diff" tab. On the lower half, use the drop down to select the external program you want to use to do the diffs and merging. I've installed KDiff3 and like it well enough. When you're done, click OK.

Now when there is a merge, you can go under Actions->Resolve Conflicts->Launch External Merge Tool.

How to download python from command-line?

apt-get install python2.7 will work on debian-like linuxes. The python website describes a whole bunch of other ways to get Python.

Web link to specific whatsapp contact

This approach only works on Android AND if you have the number on your contact list. If you don't have it, Android opens your SMS app, so you can invite the contact to use Whatsapp.

<a href="https://api.whatsapp.com/send?phone=2567xxxxxxxxx" method="get" target="_blank"><i class="fa fa-whatsapp"></i></a>

Google Chrome am targeting a blank window

HTML 5 input type="number" element for floating point numbers on Chrome

Try this

_x000D_
_x000D_
<input onkeypress='return event.charCode >= 48 && _x000D_
                          event.charCode <= 57 || _x000D_
                          event.charCode == 46'>
_x000D_
_x000D_
_x000D_

JavaScript function to add X months to a date

Taken from @bmpsini and @Jazaret responses, but not extending prototypes: using plain functions (Why is extending native objects a bad practice?):

function isLeapYear(year) { 
    return (((year % 4 === 0) && (year % 100 !== 0)) || (year % 400 === 0)); 
}

function getDaysInMonth(year, month) {
    return [31, (isLeapYear(year) ? 29 : 28), 31, 30, 31, 30, 31, 31, 30, 31, 30, 31][month];
}

function addMonths(date, value) {
    var d = new Date(date),
        n = date.getDate();
    d.setDate(1);
    d.setMonth(d.getMonth() + value);
    d.setDate(Math.min(n, getDaysInMonth(d.getFullYear(), d.getMonth())));
    return d;
}

Use it:

var nextMonth = addMonths(new Date(), 1);

Declare variable MySQL trigger

Agree with neubert about the DECLARE statements, this will fix syntax error. But I would suggest you to avoid using openning cursors, they may be slow.

For your task: use INSERT...SELECT statement which will help you to copy data from one table to another using only one query.

INSERT ... SELECT Syntax.

How can I exclude $(this) from a jQuery selector?

You can use the not function rather than the :not selector:

$(".content a").not(this).hide("slow")

awk partly string match (if column/word partly matches)

awk '$3 ~ /snow/ { print }' dummy_file 

Explanation of BASE terminology

ACID and BASE are consistency models for RDBMS and NoSQL respectively. ACID transactions are far more pessimistic i.e. they are more worried about data safety. In the NoSQL database world, ACID transactions are less fashionable as some databases have loosened the requirements for immediate consistency, data freshness and accuracy in order to gain other benefits, like scalability and resiliency.

BASE stands for -

  • Basic Availability - The database appears to work most of the time.
  • Soft-state - Stores don't have to be write-consistent, nor do different replicas have to be mutually consistent all the time.
  • Eventual consistency - Stores exhibit consistency at some later point (e.g., lazily at read time).

Therefore BASE relaxes consistency to allow the system to process request even in an inconsistent state.

Example: No one would mind if their tweet were inconsistent within their social network for a short period of time. It is more important to get an immediate response than to have a consistent state of users' information.

Fetch frame count with ffmpeg

try this:

ffmpeg -i "path to file" -f null /dev/null 2>&1 | grep 'frame=' | cut -f 2 -d ' '

Viewing unpushed Git commits

git cherry -v

This will list out your local comment history (not yet pushed) with corresponding message

How do you import an Eclipse project into Android Studio now?

Simple steps: 1.Go to Android Studio. 2.Close all open projects if any. 3.There will be an option which says import non Android Studio Projects(Eclipse ect). 4.Click on it and choose ur project Thats't it enjoy!!!

Python 3: UnboundLocalError: local variable referenced before assignment

This is because, even though Var1 exists, you're also using an assignment statement on the name Var1 inside of the function (Var1 -= 1 at the bottom line). Naturally, this creates a variable inside the function's scope called Var1 (truthfully, a -= or += will only update (reassign) an existing variable, but for reasons unknown (likely consistency in this context), Python treats it as an assignment). The Python interpreter sees this at module load time and decides (correctly so) that the global scope's Var1 should not be used inside the local scope, which leads to a problem when you try to reference the variable before it is locally assigned.

Using global variables, outside of necessity, is usually frowned upon by Python developers, because it leads to confusing and problematic code. However, if you'd like to use them to accomplish what your code is implying, you can simply add:

global Var1, Var2

inside the top of your function. This will tell Python that you don't intend to define a Var1 or Var2 variable inside the function's local scope. The Python interpreter sees this at module load time and decides (correctly so) to look up any references to the aforementioned variables in the global scope.

Some Resources

  • the Python website has a great explanation for this common issue.
  • Python 3 offers a related nonlocal statement - check that out as well.

What ports need to be open for TortoiseSVN to authenticate (clear text) and commit?

What's the first part of your Subversion repository URL?

  • If your URL looks like: http://subversion/repos/, then you're probably going over Port 80.
  • If your URL looks like: https://subversion/repos/, then you're probably going over Port 443.
  • If your URL looks like: svn://subversion/, then you're probably going over Port 3690.
  • If your URL looks like: svn+ssh://subversion/repos/, then you're probably going over Port 22.
  • If your URL contains a port number like: http://subversion/repos:8080, then you're using that port.

I can't guarantee the first four since it's possible to reconfigure everything to use different ports, of if you go through a proxy of some sort.

If you're using a VPN, you may have to configure your VPN client to reroute these to their correct ports. A lot of places don't configure their correctly VPNs to do this type of proxying. It's either because they have some sort of anal-retentive IT person who's being overly security conscious, or because they simply don't know any better. Even worse, they'll give you a client where this stuff can't be reconfigured.

The only way around that is to log into a local machine over the VPN, and then do everything from that system.

How to generate class diagram from project in Visual Studio 2013?

Right click on the project in solution explorer or class view window --> "View" --> "View Class Diagram"

How to position a CSS triangle using ::after?

Just add position:relative to the parent element .sidebar-resources-categories

http://jsfiddle.net/matthewabrman/5msuY/

explanation: the ::after elements position is based off of it's parent, in your example you probably had a parent element of the .sidebar-res... which had a set height, therefore it rendered just below it. Adding position relative to the .sidebar-res... makes the after elements move to 100% of it's parent which now becomes the .sidebar-res... because it's position is set to relative. I'm not sure how to explain it but it's expected behaviour.

read more on the subject: http://css-tricks.com/absolute-positioning-inside-relative-positioning/

How to redirect stdout to both file and console with scripting?

To redirect output to a file and a terminal without modifying how your Python script is used outside, you could use pty.spawn(itself):

#!/usr/bin/env python
"""Redirect stdout to a file and a terminal inside a script."""
import os
import pty
import sys

def main():
    print('put your code here')

if __name__=="__main__":
    sentinel_option = '--dont-spawn'
    if sentinel_option not in sys.argv:
        # run itself copying output to the log file
        with open('script.log', 'wb') as log_file:
            def read(fd):
                data = os.read(fd, 1024)
                log_file.write(data)
                return data

            argv = [sys.executable] + sys.argv + [sentinel_option]
            rc = pty.spawn(argv, read)
    else:
        sys.argv.remove(sentinel_option)
        rc = main()
    sys.exit(rc)

If pty module is not available (on Windows) then you could replace it with teed_call() function that is more portable but it provides ordinary pipes instead of a pseudo-terminal -- it may change behaviour of some programs.

The advantage of pty.spawn and subprocess.Popen -based solutions over replacing sys.stdout with a file-like object is that they can capture the output at a file descriptor level e.g., if the script starts other processes that can also produce output on stdout/stderr. See my answer to the related question: Redirect stdout to a file in Python?

file_get_contents("php://input") or $HTTP_RAW_POST_DATA, which one is better to get the body of JSON request?

Actually php://input allows you to read raw POST data.

It is a less memory intensive alternative to $HTTP_RAW_POST_DATA and does not need any special php.ini directives.

php://input is not available with enctype="multipart/form-data".

Reference: http://php.net/manual/en/wrappers.php.php

Left Join With Where Clause

The where clause is filtering away rows where the left join doesn't succeed. Move it to the join:

SELECT  `settings`.*, `character_settings`.`value`
FROM    `settings`
LEFT JOIN 
       `character_settings` 
ON     `character_settings`.`setting_id` = `settings`.`id`
        AND `character_settings`.`character_id` = '1'  

Moment.js transform to date object

moment has updated the js lib as of 06/2018.

var newYork    = moment.tz("2014-06-01 12:00", "America/New_York");
var losAngeles = newYork.clone().tz("America/Los_Angeles");
var london     = newYork.clone().tz("Europe/London");

newYork.format();    // 2014-06-01T12:00:00-04:00
losAngeles.format(); // 2014-06-01T09:00:00-07:00
london.format();     // 2014-06-01T17:00:00+01:00

if you have freedom to use Angular5+, then better use datePipe feature there than the timezone function here. I have to use moment.js because my project limits to Angular2 only.

angular2: Error: TypeError: Cannot read property '...' of undefined

Safe navigation operator or Existential Operator or Null Propagation Operator is supported in Angular Template. Suppose you have Component class

  myObj:any = {
    doSomething: function () { console.log('doing something'); return 'doing something'; },
  };
  myArray:any;
  constructor() { }

  ngOnInit() {
    this.myArray = [this.myObj];
  }

You can use it in template html file as following:

<div>test-1: {{  myObj?.doSomething()}}</div>
<div>test-2: {{  myArray[0].doSomething()}}</div>
<div>test-3: {{  myArray[2]?.doSomething()}}</div>

ASP.NET Web API - PUT & DELETE Verbs Not Allowed - IIS 8

After endless searching and trying the already supplied answers (adding the PUT,DELETE verbs and remove WEBdav) it just didn't work.

I went to IIS logging settings: > View Log Files. In my case W3SVC4 was the folder with the latest date, opened the folder, looked up the latest log file and saw this entry: GET /Rejected-By-UrlScan ~/MYDOMAIN/API/ApiName/UpdateMETHOD

The Update method was listed with verb GET, weird right? So I Googled for Rejected-By-UrlScan and found this link: UrlScan Broke My Blog.

I went to here: %windir%\system32\inetsrv\urlscan\UrlScan.ini

Basically, the UrlScan blocked PUT and DELETE verbs. I opened this INI file, added the PUT and DELETE to the AllowVerbs and removed them from the DenyVerbs listings. I saved the INI file and it worked! So for me these steps were necessary next to the ExtensionlessUrlHandler hints.

Windows Webserver 2008 R2 (64 bit), IIS 7.5. I'm using this in combination with DotNetNuke (DNN) WebAPI. ASP.Net 4.0 My update method:

[HttpPut]
[DnnAuthorize(StaticRoles = "MyRoleNames")]
public HttpResponseMessage UpdateMETHOD(DTO.MyObject myData)

Open file dialog and select a file using WPF controls and C#

Something like that should be what you need

private void button1_Click(object sender, RoutedEventArgs e)
{
    // Create OpenFileDialog 
    Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();



    // Set filter for file extension and default file extension 
    dlg.DefaultExt = ".png";
    dlg.Filter = "JPEG Files (*.jpeg)|*.jpeg|PNG Files (*.png)|*.png|JPG Files (*.jpg)|*.jpg|GIF Files (*.gif)|*.gif"; 


    // Display OpenFileDialog by calling ShowDialog method 
    Nullable<bool> result = dlg.ShowDialog();


    // Get the selected file name and display in a TextBox 
    if (result == true)
    {
        // Open document 
        string filename = dlg.FileName;
        textBox1.Text = filename;
    }
}

static and extern global variables in C and C++

Global variables are not extern nor static by default on C and C++. When you declare a variable as static, you are restricting it to the current source file. If you declare it as extern, you are saying that the variable exists, but are defined somewhere else, and if you don't have it defined elsewhere (without the extern keyword) you will get a link error (symbol not found).

Your code will break when you have more source files including that header, on link time you will have multiple references to varGlobal. If you declare it as static, then it will work with multiple sources (I mean, it will compile and link), but each source will have its own varGlobal.

What you can do in C++, that you can't in C, is to declare the variable as const on the header, like this:

const int varGlobal = 7;

And include in multiple sources, without breaking things at link time. The idea is to replace the old C style #define for constants.

If you need a global variable visible on multiple sources and not const, declare it as extern on the header, and then define it, this time without the extern keyword, on a source file:

Header included by multiple files:

extern int varGlobal;

In one of your source files:

int varGlobal = 7;

How do I declare a two dimensional array?

Or for larger arrays, all with the same value:

$m_by_n_array = array_fill(0, $n, array_fill(0, $m, $value);

will create an $m by $n array with everything set to $value.

Can't find System.Windows.Media namespace?

For Visual Studio 2017

Find "References" in Solution explorer

Right click "References"

Choose "Add Reference..."

Find "Presentation.Core" list and check checkbox

Click OK

Error occurred during initialization of VM (java/lang/NoClassDefFoundError: java/lang/Object)

please try to execute java from

C:\Program Files\Java\jdk1.7.0_10\bin

i.e from the location where java is installed.

If it is successful, it means that the error lies somewhere in the classpath.

Also, this guy seems to have had the same problem as yours, check it out

lvalue required as left operand of assignment error when using C++

To assign, you should use p=p+1; instead of p+1=p;

int main()
{

   int x[3]={4,5,6};
   int *p=x;
   p=p+1; /*You just needed to switch the terms around*/
   cout<<p<<endl;
   getch();
}

Using gradle to find dependency tree

If you want to visualize your dependencies in a graph you can use gradle-dependency-graph-generator plugin.

Generally the output of this plugin can be found in build/reports/dependency-graph directory and it contains three files (.dot|.png|.svg) if you are using the 0.5.0 version of the plugin.

Example of dependences graph in a real app (Chess Clock):

graph

Best method for reading newline delimited files and discarding the newlines?

What do you think about this approach?

with open(filename) as data:
    datalines = (line.rstrip('\r\n') for line in data)
    for line in datalines:
        ...do something awesome...

Generator expression avoids loading whole file into memory and with ensures closing the file

Using Java 8's Optional with Stream::flatMap

I'm adding this second answer based on a proposed edit by user srborlongan to my other answer. I think the technique proposed was interesting, but it wasn't really suitable as an edit to my answer. Others agreed and the proposed edit was voted down. (I wasn't one of the voters.) The technique has merit, though. It would have been best if srborlongan had posted his/her own answer. This hasn't happened yet, and I didn't want the technique to be lost in the mists of the StackOverflow rejected edit history, so I decided to surface it as a separate answer myself.

Basically the technique is to use some of the Optional methods in a clever way to avoid having to use a ternary operator (? :) or an if/else statement.

My inline example would be rewritten this way:

Optional<Other> result =
    things.stream()
          .map(this::resolve)
          .flatMap(o -> o.map(Stream::of).orElseGet(Stream::empty))
          .findFirst();

An my example that uses a helper method would be rewritten this way:

/**
 * Turns an Optional<T> into a Stream<T> of length zero or one depending upon
 * whether a value is present.
 */
static <T> Stream<T> streamopt(Optional<T> opt) {
    return opt.map(Stream::of)
              .orElseGet(Stream::empty);
}

Optional<Other> result =
    things.stream()
          .flatMap(t -> streamopt(resolve(t)))
          .findFirst();

COMMENTARY

Let's compare the original vs modified versions directly:

// original
.flatMap(o -> o.isPresent() ? Stream.of(o.get()) : Stream.empty())

// modified
.flatMap(o -> o.map(Stream::of).orElseGet(Stream::empty))

The original is a straightforward if workmanlike approach: we get an Optional<Other>; if it has a value, we return a stream containing that value, and if it has no value, we return an empty stream. Pretty simple and easy to explain.

The modification is clever and has the advantage that it avoids conditionals. (I know that some people dislike the ternary operator. If misused it can indeed make code hard to understand.) However, sometimes things can be too clever. The modified code also starts off with an Optional<Other>. Then it calls Optional.map which is defined as follows:

If a value is present, apply the provided mapping function to it, and if the result is non-null, return an Optional describing the result. Otherwise return an empty Optional.

The map(Stream::of) call returns an Optional<Stream<Other>>. If a value was present in the input Optional, the returned Optional contains a Stream that contains the single Other result. But if the value was not present, the result is an empty Optional.

Next, the call to orElseGet(Stream::empty) returns a value of type Stream<Other>. If its input value is present, it gets the value, which is the single-element Stream<Other>. Otherwise (if the input value is absent) it returns an empty Stream<Other>. So the result is correct, the same as the original conditional code.

In the comments discussing on my answer, regarding the rejected edit, I had described this technique as "more concise but also more obscure". I stand by this. It took me a while to figure out what it was doing, and it also took me a while to write up the above description of what it was doing. The key subtlety is the transformation from Optional<Other> to Optional<Stream<Other>>. Once you grok this it makes sense, but it wasn't obvious to me.

I'll acknowledge, though, that things that are initially obscure can become idiomatic over time. It might be that this technique ends up being the best way in practice, at least until Optional.stream gets added (if it ever does).

UPDATE: Optional.stream has been added to JDK 9.

How to understand nil vs. empty vs. blank in Ruby

Don't forget any? which is generally !empty?. In Rails I typically check for the presence of something at the end of a statement with if something or unless something then use blank? where needed since it seems to work everywhere.

How to perform Join between multiple tables in LINQ lambda

var query = from a in d.tbl_Usuarios
                    from b in d.tblComidaPreferidas
                    from c in d.tblLugarNacimientoes
                    select new
                    {
                        _nombre = a.Nombre,
                        _comida = b.ComidaPreferida,
                        _lNacimiento = c.Ciudad
                    };
        foreach (var i in query)
        {
            Console.WriteLine($"{i._nombre } le gusta {i._comida} y nació en {i._lNacimiento}");
        }

Forward declaring an enum in C++

Forward declaration of enums is possible since C++11. Previously, the reason enum types couldn't be forward declared is because the size of the enumeration depends on its contents. As long as the size of the enumeration is specified by the application, it can be forward declared:

enum Enum1;                   //Illegal in C++ and C++0x; no size is explicitly specified.
enum Enum2 : unsigned int;    //Legal in C++0x.
enum class Enum3;             //Legal in C++0x, because enum class declarations have a default type of "int".
enum class Enum4: unsigned int; //Legal C++0x.
enum Enum2 : unsigned short;  //Illegal in C++0x, because Enum2 was previously declared with a different type.

git pull displays "fatal: Couldn't find remote ref refs/heads/xxxx" and hangs up

To pull a remote branch locally, I do the following:

git checkout -b branchname // creates a local branch with the same name and checks out on it

git pull origin branchname // pulls the remote one onto your local one

The only time I did this and it didn't work, I deleted the repo, cloned it again and repeated the above 2 steps; it worked.

Easiest way to open a download window without navigating away from the page

This javascript is nice that it doesn't open a new window or tab.

window.location.assign(url);

Nginx: Permission denied for nginx on Ubuntu

if you don't want to start nginx as root.

first creat log file :

sudo touch /var/log/nginx/error.log

and then fix permissions:

sudo chown -R www-data:www-data /var/log/nginx

sudo find /var/log/nginx -type f -exec chmod 666 {} \;

sudo find /var/log/nginx -type d -exec chmod 755 {} \;

SqlServer: Login failed for user

We solved our Linux/php hook to SQL Server problem by creating a new login account with SQL Server authentication instead of Windows authentication.

How to add a “readonly” attribute to an <input>?

Check the code below:

<input id="mail">

<script>

 document.getElementById('mail').readOnly = true; // makes input readonline
 document.getElementById('mail').readOnly = false; // makes input writeable again

</script>

Using IF ELSE statement based on Count to execute different Insert statements

one obvious solution is to run 2 separate queries, first select all items that have count=1 and run your insert, then select the items with count>1 and run the second insert.

as a second step if the two inserts are similar you can probably combine them into one query.

another possibility is to use a cursor to loop thru your recordset and do whatever logic you need for each line.

What is a Subclass

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

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

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

public class B extends A
{
...
}

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

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

Are all Spring Framework Java Configuration injection examples buggy?

In your test, you are comparing the two TestParent beans, not the single TestedChild bean.

Also, Spring proxies your @Configuration class so that when you call one of the @Bean annotated methods, it caches the result and always returns the same object on future calls.

See here:

How to query DATETIME field using only date in Microsoft SQL Server?

select *
  from invoice
 where TRUNC(created_date) <=TRUNC(to_date('04-MAR-18 15:00:00','dd-mon-yy hh24:mi:ss'));

git is not installed or not in the PATH

Did you install Git correctly?

According to the Bower site, you need to make sure you check the option "Run Git from Windows Command Prompt".

I had this issue where Git was not found when I was trying to install Angular. I re-ran the installer for git and changed my setting and then it worked.

enter image description here

From the bower site: http://bower.io/

Abstraction VS Information Hiding VS Encapsulation

Abstraction : Abstraction is the concept/technique used to identify what should be the external view of an object. Making only the required interface available.

Information Hiding : It is complementary to Abstraction, as through information hiding Abstraction is achieved. Hiding everything else but the external view.

Encapsulation : Is binding of data and related functions into a unit. It facilitates Abstraction and information hiding. Allowing features like member access to be applied on the unit to achieve Abstraction and Information hiding

Set new id with jQuery

Use .val() not attr('value').

How can I check if a view is visible or not in Android?

Although View.getVisibility() does get the visibility, its not a simple true/false. A view can have its visibility set to one of three things.

View.VISIBLE The view is visible.

View.INVISIBLE The view is invisible, but any spacing it would normally take up will still be used. Its "invisible"

View.GONE The view is gone, you can't see it and it doesn't take up the "spot".

So to answer your question, you're looking for:

if (myImageView.getVisibility() == View.VISIBLE) {
    // Its visible
} else {
    // Either gone or invisible
}

How to make a deep copy of Java ArrayList

public class Person{

    String s;
    Date d;
    ...

    public Person clone(){
        Person p = new Person();
        p.s = this.s.clone();
        p.d = this.d.clone();
        ...
        return p;
    }
}

In your executing code:

ArrayList<Person> clone = new ArrayList<Person>();
for(Person p : originalList)
    clone.add(p.clone());

Python append() vs. + operator on lists, why do these give different results?

you should use extend()

>>> c=[1,2,3]
>>> c.extend(c)
>>> c
[1, 2, 3, 1, 2, 3]

other info: append vs. extend

Cannot redeclare function php

You (or Joomla) is likely including this file multiple times. Enclose your function in a conditional block:

if (!function_exists('parseDate')) {
    // ... proceed to declare your function
}

Reading string from input with space character?

scanf("%s",name);

use & with scanf input

What do parentheses surrounding an object/function/class declaration mean?

...but what about the previous round parenteses surrounding all the function declaration?

Specifically, it makes JavaScript interpret the 'function() {...}' construct as an inline anonymous function expression. If you omitted the brackets:

function() {
    alert('hello');
}();

You'd get a syntax error, because the JS parser would see the 'function' keyword and assume you're starting a function statement of the form:

function doSomething() {
}

...and you can't have a function statement without a function name.

function expressions and function statements are two different constructs which are handled in very different ways. Unfortunately the syntax is almost identical, so it's not just confusing to the programmer, even the parser has difficulty telling which you mean!

Expression must be a modifiable lvalue

In C, you will also experience the same error if you declare a:

char array[size];

and than try to assign a value without specifying an index position:

array = '\0'; 

By doing:

array[index] = '0\';

You're specifying the accessible/modifiable address previously declared.

Array initializing in Scala

scala> val arr = Array("Hello","World")
arr: Array[java.lang.String] = Array(Hello, World)

What is Hash and Range Primary Key?

As the whole thing is mixing up let's look at it function and code to simulate what it means consicely

The only way to get a row is via primary key

getRow(pk: PrimaryKey): Row

Primary key data structure can be this:

// If you decide your primary key is just the partition key.
class PrimaryKey(partitionKey: String)

// and in thids case
getRow(somePartitionKey): Row

However you can decide your primary key is partition key + sort key in this case:

// if you decide your primary key is partition key + sort key
class PrimaryKey(partitionKey: String, sortKey: String)

getRow(partitionKey, sortKey): Row
getMultipleRows(partitionKey): Row[]

So the bottom line:

  1. Decided that your primary key is partition key only? get single row by partition key.

  2. Decided that your primary key is partition key + sort key? 2.1 Get single row by (partition key, sort key) or get range of rows by (partition key)

In either way you get a single row by primary key the only question is if you defined that primary key to be partition key only or partition key + sort key

Building blocks are:

  1. Table
  2. Item
  3. KV Attribute.

Think of Item as a row and of KV Attribute as cells in that row.

  1. You can get an item (a row) by primary key.
  2. You can get multiple items (multiple rows) by specifying (HashKey, RangeKeyQuery)

You can do (2) only if you decided that your PK is composed of (HashKey, SortKey).

More visually as its complex, the way I see it:

+----------------------------------------------------------------------------------+
|Table                                                                             |
|+------------------------------------------------------------------------------+  |
||Item                                                                          |  |
||+-----------+ +-----------+ +-----------+ +-----------+                       |  |
|||primaryKey | |kv attr    | |kv attr ...| |kv attr ...|                       |  |
||+-----------+ +-----------+ +-----------+ +-----------+                       |  |
|+------------------------------------------------------------------------------+  |
|+------------------------------------------------------------------------------+  |
||Item                                                                          |  |
||+-----------+ +-----------+ +-----------+ +-----------+ +-----------+         |  |
|||primaryKey | |kv attr    | |kv attr ...| |kv attr ...| |kv attr ...|         |  |
||+-----------+ +-----------+ +-----------+ +-----------+ +-----------+         |  |
|+------------------------------------------------------------------------------+  |
|                                                                                  |
+----------------------------------------------------------------------------------+

+----------------------------------------------------------------------------------+
|1. Always get item by PrimaryKey                                                  |
|2. PK is (Hash,RangeKey), great get MULTIPLE Items by Hash, filter/sort by range     |
|3. PK is HashKey: just get a SINGLE ITEM by hashKey                               |
|                                                      +--------------------------+|
|                                 +---------------+    |getByPK => getBy(1        ||
|                 +-----------+ +>|(HashKey,Range)|--->|hashKey, > < or startWith ||
|              +->|Composite  |-+ +---------------+    |of rangeKeys)             ||
|              |  +-----------+                        +--------------------------+|
|+-----------+ |                                                                   |
||PrimaryKey |-+                                                                   |
|+-----------+ |                                       +--------------------------+|
|              |  +-----------+   +---------------+    |getByPK => get by specific||
|              +->|HashType   |-->|get one item   |--->|hashKey                   ||
|                 +-----------+   +---------------+    |                          ||
|                                                      +--------------------------+|
+----------------------------------------------------------------------------------+

So what is happening above. Notice the following observations. As we said our data belongs to (Table, Item, KVAttribute). Then Every Item has a primary key. Now the way you compose that primary key is meaningful into how you can access the data.

If you decide that your PrimaryKey is simply a hash key then great you can get a single item out of it. If you decide however that your primary key is hashKey + SortKey then you could also do a range query on your primary key because you will get your items by (HashKey + SomeRangeFunction(on range key)). So you can get multiple items with your primary key query.

Note: I did not refer to secondary indexes.

Is it possible to pull just one file in Git?

Here is a slightly easier method I just came up with when researching this:

git fetch {remote}
git checkout FETCH_HEAD -- {file}

How do I get the current time zone of MySQL?

Insert a dummy record into one of your databases that has a timestamp Select that record and get value of timestamp. Delete that record. Gets for sure the timezone that the server is using to write data and ignores PHP timezones.

Django model "doesn't declare an explicit app_label"

O...M...G I was getting this error too and I spent almost 2 days on it and now I finally managed to solve it. Honestly...the error had nothing to do with what the problem was. In my case it was a simple matter of syntax. I was trying to run a python module standalone that used some django models in a django context, but the module itself wasn't a django model. But I was declaring the class wrong

instead of having

class Scrapper:
    name = ""
    main_link= ""
    ...

I was doing

class Scrapper(Website):
    name = ""
    main_link= ""
    ...

which is obviously wrong. The message is so misleading that I couldn't help myself but think it was some issue with configuration or just using django in a wrong way since I'm very new to it.

I'll share this here for someone newbie as me going through the same silliness can hopefully solve their issue.

Adding a slide effect to bootstrap dropdown

Expanded answer, was my first answer so excuse if there wasn’t enough detail before.

For Bootstrap 3.x I personally prefer CSS animations and I've been using animate.css & along with the Bootstrap Dropdown Javascript Hooks. Although it might not have the exactly effect you're after it's a pretty flexible approach.

Step 1: Add animate.css to your page with the head tags:

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/animate.css/3.4.0/animate.min.css">

Step 2: Use the standard Bootstrap HTML on the trigger:

<div class="dropdown">
  <button type="button" data-toggle="dropdown">Dropdown trigger</button>

  <ul class="dropdown-menu">
    ...
  </ul>
</div>

Step 3: Then add 2 custom data attributes to the dropdrop-menu element; data-dropdown-in for the in animation and data-dropdown-out for the out animation. These can be any animate.css effects like fadeIn or fadeOut

<ul class="dropdown-menu" data-dropdown-in="fadeIn" data-dropdown-out="fadeOut">
......
</ul>

Step 4: Next add the following Javascript to read the data-dropdown-in/out data attributes and react to the Bootstrap Javascript API hooks/events (http://getbootstrap.com/javascript/#dropdowns-events):

var dropdownSelectors = $('.dropdown, .dropup');

// Custom function to read dropdown data
// =========================
function dropdownEffectData(target) {
  // @todo - page level global?
  var effectInDefault = null,
      effectOutDefault = null;
  var dropdown = $(target),
      dropdownMenu = $('.dropdown-menu', target);
  var parentUl = dropdown.parents('ul.nav'); 

  // If parent is ul.nav allow global effect settings
  if (parentUl.size() > 0) {
    effectInDefault = parentUl.data('dropdown-in') || null;
    effectOutDefault = parentUl.data('dropdown-out') || null;
  }

  return {
    target:       target,
    dropdown:     dropdown,
    dropdownMenu: dropdownMenu,
    effectIn:     dropdownMenu.data('dropdown-in') || effectInDefault,
    effectOut:    dropdownMenu.data('dropdown-out') || effectOutDefault,  
  };
}

// Custom function to start effect (in or out)
// =========================
function dropdownEffectStart(data, effectToStart) {
  if (effectToStart) {
    data.dropdown.addClass('dropdown-animating');
    data.dropdownMenu.addClass('animated');
    data.dropdownMenu.addClass(effectToStart);    
  }
}

// Custom function to read when animation is over
// =========================
function dropdownEffectEnd(data, callbackFunc) {
  var animationEnd = 'webkitAnimationEnd mozAnimationEnd MSAnimationEnd oanimationend animationend';
  data.dropdown.one(animationEnd, function() {
    data.dropdown.removeClass('dropdown-animating');
    data.dropdownMenu.removeClass('animated');
    data.dropdownMenu.removeClass(data.effectIn);
    data.dropdownMenu.removeClass(data.effectOut);

    // Custom callback option, used to remove open class in out effect
    if(typeof callbackFunc == 'function'){
      callbackFunc();
    }
  });
}

// Bootstrap API hooks
// =========================
dropdownSelectors.on({
  "show.bs.dropdown": function () {
    // On show, start in effect
    var dropdown = dropdownEffectData(this);
    dropdownEffectStart(dropdown, dropdown.effectIn);
  },
  "shown.bs.dropdown": function () {
    // On shown, remove in effect once complete
    var dropdown = dropdownEffectData(this);
    if (dropdown.effectIn && dropdown.effectOut) {
      dropdownEffectEnd(dropdown, function() {}); 
    }
  },  
  "hide.bs.dropdown":  function(e) {
    // On hide, start out effect
    var dropdown = dropdownEffectData(this);
    if (dropdown.effectOut) {
      e.preventDefault();   
      dropdownEffectStart(dropdown, dropdown.effectOut);   
      dropdownEffectEnd(dropdown, function() {
        dropdown.dropdown.removeClass('open');
      }); 
    }    
  }, 
});

Step 5 (optional): If you want to speed up or alter the animation you can do so with CSS like the following:

.dropdown-menu.animated {
  /* Speed up animations */
  -webkit-animation-duration: 0.55s;
  animation-duration: 0.55s;
  -webkit-animation-timing-function: ease;
  animation-timing-function: ease;
}

Wrote an article with more detail and a download if anyones interested: article: http://bootbites.com/tutorials/bootstrap-dropdown-effects-animatecss

Hope that’s helpful & this second write up has the level of detail that’s needed Tom

check if a number already exist in a list in python

You could probably use a set object instead. Just add numbers to the set. They inherently do not replicate.

Converting String To Float in C#

You can double.Parse("41.00027357629127");

JavaScript error: "is not a function"

I also hit this error. In my case the root cause was async related (during a codebase refactor): An asynchronous function that builds the object to which the "not a function" function belongs was not awaited, and the subsequent attempt to invoke the function throws the error, example below:

const car = carFactory.getCar();
car.drive() //throws TypeError: drive is not a function

The fix was:

const car = await carFactory.getCar();
car.drive()

Posting this incase it helps anyone else facing this error.

How to Decrease Image Brightness in CSS

Like

.classname
{
 opacity: 0.5;
}

tkinter: how to use after method

I believe, the 500ms run in the background, while the rest of the code continues to execute and empties the list.

Then after 500ms nothing happens, as no function-call is implemented in the after-callup (same as frame.after(500, function=None))

Why is python setup.py saying invalid command 'bdist_wheel' on Travis CI?

It helped me to follow instructions in here:

https://packaging.python.org/guides/installing-using-linux-tools/

Debian/Ubuntu

Python 2:

sudo apt install python-pip

Python 3:

sudo apt install python3-venv python3-pip

When should I use double or single quotes in JavaScript?

I hope I am not adding something obvious, but I have been struggling with Django, Ajax, and JSON on this.

Assuming that in your HTML code you do use double quotes, as normally should be, I highly suggest to use single quotes for the rest in JavaScript.

So I agree with ady, but with some care.

My bottom line is:

In JavaScript it probably doesn't matter, but as soon as you embed it inside HTML or the like you start to get troubles. You should know what is actually escaping, reading, passing your string.

My simple case was:

tbox.innerHTML = tbox.innerHTML + '<div class="thisbox_des" style="width:210px;" onmouseout="clear()"><a href="/this/thislist/'
                   + myThis[i].pk +'"><img src="/site_media/'
                   + myThis[i].fields.thumbnail +'" height="80" width="80" style="float:left;" onmouseover="showThis('
                   + myThis[i].fields.left +','
                   + myThis[i].fields.right +',\''
                   + myThis[i].fields.title +'\')"></a><p style="float:left;width:130px;height:80px;"><b>'
                   + myThis[i].fields.title +'</b> '
                   + myThis[i].fields.description +'</p></div>'

You can spot the ' in the third field of showThis.

The double quote didn't work!

It is clear why, but it is also clear why we should stick to single quotes... I guess...

This case is a very simple HTML embedding, and the error was generated by a simple copy/paste from a 'double quoted' JavaScript code.

So to answer the question:

Try to use single quotes while within HTML. It might save a couple of debug issues...

How can I check if a Perl module is installed on my system from the command line?

I believe your solution will only look in the root of each directory path contained in the @INC array. You need something recursive, like:

 perl -e 'foreach (@INC) {
    print `find $_ -type f -name "*.pm"`;
 }'

Compare two Lists for differences

I hope that I am understing your question correctly, but you can do this very quickly with Linq. I'm assuming that universally you will always have an Id property. Just create an interface to ensure this.

If how you identify an object to be the same changes from class to class, I would recommend passing in a delegate that returns true if the two objects have the same persistent id.

Here is how to do it in Linq:

List<Employee> listA = new List<Employee>();
        List<Employee> listB = new List<Employee>();

        listA.Add(new Employee() { Id = 1, Name = "Bill" });
        listA.Add(new Employee() { Id = 2, Name = "Ted" });

        listB.Add(new Employee() { Id = 1, Name = "Bill Sr." });
        listB.Add(new Employee() { Id = 3, Name = "Jim" });

        var identicalQuery = from employeeA in listA
                             join employeeB in listB on employeeA.Id equals employeeB.Id
                             select new { EmployeeA = employeeA, EmployeeB = employeeB };

        foreach (var queryResult in identicalQuery)
        {
            Console.WriteLine(queryResult.EmployeeA.Name);
            Console.WriteLine(queryResult.EmployeeB.Name);
        }

Parse an HTML string with JS

Create a dummy DOM element and add the string to it. Then, you can manipulate it like any DOM element.

var el = document.createElement( 'html' );
el.innerHTML = "<html><head><title>titleTest</title></head><body><a href='test0'>test01</a><a href='test1'>test02</a><a href='test2'>test03</a></body></html>";

el.getElementsByTagName( 'a' ); // Live NodeList of your anchor elements

Edit: adding a jQuery answer to please the fans!

var el = $( '<div></div>' );
el.html("<html><head><title>titleTest</title></head><body><a href='test0'>test01</a><a href='test1'>test02</a><a href='test2'>test03</a></body></html>");

$('a', el) // All the anchor elements

How to convert Java String into byte[]?

Try using String.getBytes(). It returns a byte[] representing string data. Example:

String data = "sample data";
byte[] byteData = data.getBytes();

How to deselect all selected rows in a DataGridView control?

Thanks Cody heres the c# for ref:

if (e.Button == System.Windows.Forms.MouseButtons.Left)
        {
            DataGridView.HitTestInfo hit = dgv_track.HitTest(e.X, e.Y);
            if (hit.Type == DataGridViewHitTestType.None)
            {
                dgv_track.ClearSelection();
                dgv_track.CurrentCell = null;
            }
        }

How to put img inline with text

Images have display: inline by default.
You might want to put the image inside the paragraph.
<p><img /></p>

How to get the fragment instance from the FragmentActivity?

To get the fragment instance in a class that extends FragmentActivity:

MyclassFragment instanceFragment=
    (MyclassFragment)getSupportFragmentManager().findFragmentById(R.id.idFragment);

To get the fragment instance in a class that extends Fragment:

MyclassFragment instanceFragment =  
    (MyclassFragment)getFragmentManager().findFragmentById(R.id.idFragment);

nvm is not compatible with the npm config "prefix" option:

Just resolved the issue. I symlinked $HOME/.nvm to $DEV_ZONE/env/node/nvm directory. I was facing same issue. I replaced NVM_DIR in $HOME/.zshrc as follows

export NVM_DIR="$DEV_ZONE/env/node/nvm"

BTW, please install NVM using curl or wget command not by using brew. For more please check the comment in this issue on Github: 855#issuecomment-146115434

creating Hashmap from a JSON String

No JSON libraries, just String and HashMap.
Keeps it simple!
Hope it suits to all.

// JSON Transform to HashMap example based on String

    String tempJson = "{\"incomePhone\":\"213121122\",\"clientId\":\"1001\",\"clientAccountManager\":\"Gestor de Conta 1\",\"clientRetailBranch\":\"100\",\"phoneAccountManager\":\"7800100\"}";
    System.out.println(tempJson);

    String[] parts = tempJson.split(",");
    HashMap<String,String> jsonHash = new HashMap<String,String>();

    for(int i=0;i<parts.length;i++){
        parts[i]    =   parts[i].replace("\"", "");
        parts[i]    =   parts[i].replace("{", "");
        parts[i]    =   parts[i].replace("}", "");
        String[] subparts = parts[i].split(":");
        jsonHash.put(subparts[0],subparts[1]);
    }

XAMPP permissions on Mac OS X?

You can also simply change Apache Conf file to a different User Name and keep the group:

Apache Conf Applications/Xammp/etc/..

User 'User' = your user name in Mac os x.

Group daemon

sudo chown -R 'User':daemon ~/Sites/wordpress 

sudo chmod -R g+w ~/Sites/wordpress

JFrame: How to disable window resizing?

Use setResizable on your JFrame

yourFrame.setResizable(false);

But extending JFrame is generally a bad idea.

The view didn't return an HttpResponse object. It returned None instead

if qs.count()==1:
        print('cart id exists')
        if ....

else:    
        return render(request,"carts/home.html",{})

Such type of code will also return you the same error this is because of the intents as the return statement should be for else not for if statement.

above code can be changed to

if qs.count()==1:
        print('cart id exists')
        if ....

else:   

return render(request,"carts/home.html",{})

This may solve such issues

How to vertically align text in input type="text"?

Use padding to fake it since vertical-align doesn't work on text inputs.

jsFiddle example

CSS

.date-input {     
    width: 145px;
    padding-top: 80px;
}?

Cannot ignore .idea/workspace.xml - keeps popping up

To remove .idea/ completely from the git without affecting your IDE config you could just do:

git rm -r --cached '.idea/'
echo .idea >> .gitignore
git commit -am "removed .idea/ directory"

How can I run a windows batch file but hide the command window?

Native C++ codified version of Oleg's answer -- this is copy/pasted from a project I work on under the Boost Software License.

BOOL noError;
STARTUPINFO startupInfo;
PROCESS_INFORMATION processInformation;
ZeroMemory(&startupInfo, sizeof(startupInfo));
startupInfo.cb = sizeof(startupInfo);
startupInfo.dwFlags = STARTF_USESHOWWINDOW;
startupInfo.wShowWindow = SW_HIDE;
noError = CreateProcess(
    NULL,                                           //lpApplicationName
    //Okay the const_cast is bad -- this code was written a while ago.
    //should probably be &commandLine[0] instead. Oh, and commandLine is
    //a std::wstring
    const_cast<LPWSTR>(commandLine.c_str()),        //lpCommandLine
    NULL,                                           //lpProcessAttributes
    NULL,                                           //lpThreadAttributes
    FALSE,                                          //bInheritHandles
    CREATE_NO_WINDOW | CREATE_UNICODE_ENVIRONMENT,  //dwCreationFlags
    //This is for passing in a custom environment block -- you can probably
    //just use NULL here.
    options.e ? environment : NULL,                 //lpEnvironment
    NULL,                                           //lpCurrentDirectory
    &startupInfo,                                   //lpStartupInfo
    &processInformation                             //lpProcessInformation
);

if(!noError)
{
    return GetLastError();
}

DWORD exitCode = 0;

if (options.w) //Wait
{
    WaitForSingleObject(processInformation.hProcess, INFINITE);
    if (GetExitCodeProcess(processInformation.hProcess, &exitCode) == 0)
    {
        exitCode = (DWORD)-1;
    }
}

CloseHandle( processInformation.hProcess );
CloseHandle( processInformation.hThread );

Java List.add() UnsupportedOperationException

You must initialize your List seeAlso :

List<String> seeAlso = new Vector<String>();

or

List<String> seeAlso = new ArrayList<String>();

OpenMP set_num_threads() is not working

Besides calling omp_get_num_threads() outside of the parallel region in your case, calling omp_set_num_threads() still doesn't guarantee that the OpenMP runtime will use exactly the specified number of threads. omp_set_num_threads() is used to override the value of the environment variable OMP_NUM_THREADS and they both control the upper limit of the size of the thread team that OpenMP would spawn for all parallel regions (in the case of OMP_NUM_THREADS) or for any consequent parallel region (after a call to omp_set_num_threads()). There is something called dynamic teams that could still pick smaller number of threads if the run-time system deems it more appropriate. You can disable dynamic teams by calling omp_set_dynamic(0) or by setting the environment variable OMP_DYNAMIC to false.

To enforce a given number of threads you should disable dynamic teams and specify the desired number of threads with either omp_set_num_threads():

omp_set_dynamic(0);     // Explicitly disable dynamic teams
omp_set_num_threads(4); // Use 4 threads for all consecutive parallel regions
#pragma omp parallel ...
{
    ... 4 threads used here ...
}

or with the num_threads OpenMP clause:

omp_set_dynamic(0);     // Explicitly disable dynamic teams
// Spawn 4 threads for this parallel region only
#pragma omp parallel ... num_threads(4)
{
    ... 4 threads used here ...
}

Improve subplot size/spacing with many subplots in matplotlib

Try using plt.tight_layout

As a quick example:

import matplotlib.pyplot as plt

fig, axes = plt.subplots(nrows=4, ncols=4)
fig.tight_layout() # Or equivalently,  "plt.tight_layout()"

plt.show()

Without Tight Layout

enter image description here


With Tight Layout enter image description here

How to prettyprint a JSON file?

You could use the built-in module pprint (https://docs.python.org/3.9/library/pprint.html).

How you can read the file with json data and print it out.

import json
import pprint

json_data = None
with open('file_name.txt', 'r') as f:
    data = f.read()
    json_data = json.loads(data)

pprint.pprint(json_data)

How to pip install a package with min and max version range?

you can also use:

pip install package==0.5.*

which is more consistent and easy to read.

CSS styling in Django forms

Edit: Another (slightly better) way of doing what I'm suggesting is answered here: Django form input field styling

All the above options are awesome, just thought I'd throw in this one because it's different.

If you want custom styling, classes, etc. on your forms, you can make an html input in your template that matches your form field. For a CharField, for example, (default widget is TextInput), let's say you want a bootstrap-looking text input. You would do something like this:

<input type="text" class="form-control" name="form_field_name_here">

And as long as you put the form field name matches the html name attribue, (and the widget probably needs to match the input type as well) Django will run all the same validators on that field when you run validate or form.is_valid() and

Styling other things like labels, error messages, and help text don't require much workaround because you can do something like form.field.error.as_text and style them however you want. The actual fields are the ones that require some fiddling.

I don't know if this is the best way, or the way I would recommend, but it is a way, and it might be right for someone.

Here's a useful walkthrough of styling forms and it includes most of the answers listed on SO (like using the attr on the widgets and widget tweaks). https://simpleisbetterthancomplex.com/article/2017/08/19/how-to-render-django-form-manually.html

How to make rounded percentages add up to 100%

If you really must round them, there are already very good suggestions here (largest remainder, least relative error, and so on).

There is also already one good reason not to round (you'll get at least one number that "looks better" but is "wrong"), and how to solve that (warn your readers) and that is what I do.

Let me add on the "wrong" number part.

Suppose you have three events/entitys/... with some percentages that you approximate as:

DAY 1
who |  real | app
----|-------|------
  A | 33.34 |  34
  B | 33.33 |  33
  C | 33.33 |  33

Later on the values change slightly, to

DAY 2
who |  real | app
----|-------|------
  A | 33.35 |  33
  B | 33.36 |  34
  C | 33.29 |  33

The first table has the already mentioned problem of having a "wrong" number: 33.34 is closer to 33 than to 34.

But now you have a bigger error. Comparing day 2 to day 1, the real percentage value for A increased, by 0.01%, but the approximation shows a decrease by 1%.

That is a qualitative error, probably quite worse that the initial quantitative error.

One could devise a approximation for the whole set but, you may have to publish data on day one, thus you'll not know about day two. So, unless you really, really, must approximate, you probably better not.

How to get the current time in milliseconds in C Programming

quick answer

#include<stdio.h>   
#include<time.h>   

int main()   
{   
    clock_t t1, t2;  
    t1 = clock();   
    int i;
    for(i = 0; i < 1000000; i++)   
    {   
        int x = 90;  
    }   

    t2 = clock();   

    float diff = ((float)(t2 - t1) / 1000000.0F ) * 1000;   
    printf("%f",diff);   

    return 0;   
}

mysql is not recognised as an internal or external command,operable program or batch

I am using xampp. For me best option is to change environment variables. Environment variable changing window is shared by @Abu Bakr in this thread

I change the path value as C:\xampp\mysql\bin; and it is working nice

Replace preg_replace() e modifier with preg_replace_callback

In a regular expression, you can "capture" parts of the matched string with (brackets); in this case, you are capturing the (^|_) and ([a-z]) parts of the match. These are numbered starting at 1, so you have back-references 1 and 2. Match 0 is the whole matched string.

The /e modifier takes a replacement string, and substitutes backslash followed by a number (e.g. \1) with the appropriate back-reference - but because you're inside a string, you need to escape the backslash, so you get '\\1'. It then (effectively) runs eval to run the resulting string as though it was PHP code (which is why it's being deprecated, because it's easy to use eval in an insecure way).

The preg_replace_callback function instead takes a callback function and passes it an array containing the matched back-references. So where you would have written '\\1', you instead access element 1 of that parameter - e.g. if you have an anonymous function of the form function($matches) { ... }, the first back-reference is $matches[1] inside that function.

So a /e argument of

'do_stuff(\\1) . "and" . do_stuff(\\2)'

could become a callback of

function($m) { return do_stuff($m[1]) . "and" . do_stuff($m[2]); }

Or in your case

'strtoupper("\\2")'

could become

function($m) { return strtoupper($m[2]); }

Note that $m and $matches are not magic names, they're just the parameter name I gave when declaring my callback functions. Also, you don't have to pass an anonymous function, it could be a function name as a string, or something of the form array($object, $method), as with any callback in PHP, e.g.

function stuffy_callback($things) {
    return do_stuff($things[1]) . "and" . do_stuff($things[2]);
}
$foo = preg_replace_callback('/([a-z]+) and ([a-z]+)/', 'stuffy_callback', 'fish and chips');

As with any function, you can't access variables outside your callback (from the surrounding scope) by default. When using an anonymous function, you can use the use keyword to import the variables you need to access, as discussed in the PHP manual. e.g. if the old argument was

'do_stuff(\\1, $foo)'

then the new callback might look like

function($m) use ($foo) { return do_stuff($m[1], $foo); }

Gotchas

  • Use of preg_replace_callback is instead of the /e modifier on the regex, so you need to remove that flag from your "pattern" argument. So a pattern like /blah(.*)blah/mei would become /blah(.*)blah/mi.
  • The /e modifier used a variant of addslashes() internally on the arguments, so some replacements used stripslashes() to remove it; in most cases, you probably want to remove the call to stripslashes from your new callback.

AttributeError: 'module' object has no attribute 'urlopen'

Change TWO lines:

import urllib.request #line1

#Replace
urllib.urlopen("http://www.python.org")
#To
urllib.request.urlopen("http://www.python.org") #line2

If You got ERROR 403: Forbidden Error exception try this:

siteurl = "http://www.python.org"

req = urllib.request.Request(siteurl, headers={'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.100 Safari/537.36'})
pageHTML = urllib.request.urlopen(req).read()

I hope your problem resolved.

How to calculate percentage with a SQL statement

I had a similar issue to this. you should be able to get the correct result multiplying by 1.0 instead of 100.See example Image attached

Select Grade, (Count(Grade)* 1.0 / (Select Count(*) From MyTable)) as Score From MyTable Group By Grade See reference image attached

I cannot start SQL Server browser

right click on SQL Server browser and properties, then Connection tab and chose open session with system account and not this account. then apply and chose automatic and finally run the server.

SQL query for a carriage return in a string and ultimately removing carriage return

Something like this seems to work for me:

SELECT * FROM Parameters WHERE Name LIKE '%\n%'

How do I turn off the output from tar commands on Unix?

Just drop the option v.

-v is for verbose. If you don't use it then it won't display:

tar -zxf tmp.tar.gz -C ~/tmp1

How to tell if a connection is dead in python

From the link Jweede posted:

exception socket.timeout:

This exception is raised when a timeout occurs on a socket
which has had timeouts enabled via a prior call to settimeout().
The accompanying value is a string whose value is currently
always “timed out”.

Here are the demo server and client programs for the socket module from the python docs

# Echo server program
import socket

HOST = ''                 # Symbolic name meaning all available interfaces
PORT = 50007              # Arbitrary non-privileged port
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
print 'Connected by', addr
while 1:
    data = conn.recv(1024)
    if not data: break
    conn.send(data)
conn.close()

And the client:

# Echo client program
import socket

HOST = 'daring.cwi.nl'    # The remote host
PORT = 50007              # The same port as used by the server
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
s.send('Hello, world')
data = s.recv(1024)
s.close()
print 'Received', repr(data)

On the docs example page I pulled these from, there are more complex examples that employ this idea, but here is the simple answer:

Assuming you're writing the client program, just put all your code that uses the socket when it is at risk of being dropped, inside a try block...

try:
    s.connect((HOST, PORT))
    s.send("Hello, World!")
    ...
except socket.timeout:
    # whatever you need to do when the connection is dropped

How can I suppress the newline after a print statement?

Code for Python 3.6.1

print("This first text and " , end="")

print("second text will be on the same line")

print("Unlike this text which will be on a newline")

Output

>>>
This first text and second text will be on the same line
Unlike this text which will be on a newline

What does the 'export' command do?

In simple terms, environment variables are set when you open a new shell session. At any time if you change any of the variable values, the shell has no way of picking that change. that means the changes you made become effective in new shell sessions. The export command, on the other hand, provides the ability to update the current shell session about the change you made to the exported variable. You don't have to wait until new shell session to use the value of the variable you changed.

How to enable PHP's openssl extension to install Composer?

C:\wamp\bin\php\php5.3.13

Browse to the line that reads:

;extension=php_openssl.dll

and remove the semicolon preceding the line. Restart your WAMP server services (click in your icon tray > 'Restart All Services'

How do I migrate an SVN repository with history to a new Git repository?

There is a new solution for smooth migration from Subversion to Git (or for using both simultaneously): SubGit.

I'm working on this project myself. We use SubGit in our repositories - some of my teammates use Git and some Subversion and so far it works very well.

To migrate from Subversion to Git with SubGit you need to run:

$ subgit install svn_repos
...
TRANSLATION SUCCESSFUL 

After that you'll get Git repository in svn_repos/.git and may clone it, or just continue to use Subversion and this new Git repository together: SubGit will make sure that both are always kept in sync.

In case your Subversion repository contains multiple projects, then multiple Git repositories will be created in svn_repos/git directory. To customize translation before running it do the following:

$ subgit configure svn_repos
$ edit svn_repos/conf/subgit.conf (change mapping, add authors mapping, etc)
$ subgit install svn_repos

With SubGit you may migrate to pure Git (not git-svn) and start using it while still keeping Subversion as long as you need it (for your already configured build tools, for instance).

Hope this helps!

Apache 2.4 - Request exceeded the limit of 10 internal redirects due to probable configuration error

This problem can be caused by requests for certain files that don't exist. For example, requests for files in wp-content/uploads/ where the file does not exist.

If this is the situation you're seeing, you can solve the problem by going to .htaccess and changing this line:

RewriteRule ^(wp-(content|admin|includes).*) $1 [L]

to:

RewriteRule ^(wp-(content|admin|includes).*) - [L]

The underlying issue is that the rule above triggers a rewrite to the exact same url with a slash in front and because there was a rewrite, the newly rewritten request goes back through the rules again and the same rule is triggered. By changing that line's "$1" to "-", no rewrite happens and so the rewriting process does not start over again with the same URL.

It's possible that there's a difference in how apache 2.2 and 2.4 handle this situation of only-difference-is-a-slash-in-front and that's why the default rules provided by WordPress aren't working perfectly.

Pandas count(distinct) equivalent

Using crosstab, this will return more information than groupby nunique

pd.crosstab(df.YEARMONTH,df.CLIENTCODE)
Out[196]: 
CLIENTCODE  1  2  3
YEARMONTH          
201301      2  1  0
201302      1  2  1

After a little bit modify ,yield the result

pd.crosstab(df.YEARMONTH,df.CLIENTCODE).ne(0).sum(1)
Out[197]: 
YEARMONTH
201301    2
201302    3
dtype: int64

how do I get the bullet points of a <ul> to center with the text?

ul {
  padding-left: 0;
  list-style-position: inside;
}

Explanation: The first property padding-left: 0 clears the default padding/spacing for the ul element while list-style-position: inside makes the dots/bullets of li aligned like a normal text.

So this code

<p>The ul element</p>
<ul>
asdfas
  <li>Coffee</li>
  <li>Tea</li>
  <li>Milk</li>
</ul>

without any CSS will give us this:
enter image description here
but if we add in the CSS give at the top, that will give us this:
enter image description here

How read Doc or Docx file in java?

Here is the code of ReadDoc/docx.java: This will read a dox/docx file and print its content to the console. you can customize it your way.

import java.io.*;
import org.apache.poi.hwpf.HWPFDocument;
import org.apache.poi.hwpf.extractor.WordExtractor;

public class ReadDocFile
{
    public static void main(String[] args)
    {
        File file = null;
        WordExtractor extractor = null;
        try
        {

            file = new File("c:\\New.doc");
            FileInputStream fis = new FileInputStream(file.getAbsolutePath());
            HWPFDocument document = new HWPFDocument(fis);
            extractor = new WordExtractor(document);
            String[] fileData = extractor.getParagraphText();
            for (int i = 0; i < fileData.length; i++)
            {
                if (fileData[i] != null)
                    System.out.println(fileData[i]);
            }
        }
        catch (Exception exep)
        {
            exep.printStackTrace();
        }
    }
}

What is the use of static variable in C#? When to use it? Why can't I declare the static variable inside method?

Starting from this @Kartik Patel example , I have changed a little maybe now is more clear about static variable

 public class Variable
    {
        public static string StaticName = "Sophia ";
        public string nonStName = "Jenna ";
        public void test()
        {
            StaticName = StaticName + " Lauren"; 
            Console.WriteLine("  static ={0}",StaticName);
            nonStName = nonStName + "Bean ";
            Console.WriteLine("  NeStatic neSt={0}", nonStName);

        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            Variable var = new Variable();
            var.test();
            Variable var1 = new Variable();
            var1.test();
            Variable var2 = new Variable();
            var2.test();
            Console.ReadKey();

        }
    }

Output 
  static =Sophia  Lauren
  NeStatic neSt=Jenna Bean
  static =Sophia  Lauren Lauren
  NeStatic neSt=Jenna Bean
  static =Sophia  Lauren Lauren Lauren
  NeStatic neSt=Jenna Bean
  1. Class Variable VS Instance Variable in C#

    Static Class Members C# OR Class Variable

    class A
    {
        // Class variable or " static member variable"  are declared with 
        //the "static " keyword
    
        public static int i=20;
        public int j=10;         //Instance variable 
        public static string s1="static class variable"; //Class variable 
        public string s2="instance variable";        // instance variable 
    }
    class Program
    {
        static void Main(string[] args)
        {
            A obj1 = new A();
    
            // obj1 instance variables 
            Console.WriteLine("obj1 instance variables ");
            Console.WriteLine(A.i);
            Console.WriteLine(obj1.j);
            Console.WriteLine(obj1.s2);
            Console.WriteLine(A.s1);
    
            A obj2 = new A();
    
            // obj2 instance variables 
            Console.WriteLine("obj2 instance variables ");
            Console.WriteLine(A.i);
            Console.WriteLine(obj2.j);
            Console.WriteLine(obj2.s2);
            Console.WriteLine(A.s1);
    
            Console.ReadKey();
    
        }
    
    
    }
    

    }

enter image description here enter image description here enter image description here enter image description here

https://en.wikipedia.org/wiki/Class_variable

https://en.wikipedia.org/wiki/Instance_variable

https://en.wikipedia.org/wiki/Static_variable

https://javaconceptoftheday.com/class-variables-and-instance-variables-in-java/?fbclid=IwAR1_dtpHzg3bC5WlGQGdgewaTvuOI6cwVeFUtTV8IZuGTj1qH5PmKGwX0yM

https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/classes-and-structs/static-classes-and-static-class-members

How do I get the absolute directory of a file in bash?

This will work for both file and folder:

absPath(){
    if [[ -d "$1" ]]; then
        cd "$1"
        echo "$(pwd -P)"
    else 
        cd "$(dirname "$1")"
        echo "$(pwd -P)/$(basename "$1")"
    fi
}

JavaScript regex for alphanumeric string with length of 3-5 chars

First this script test the strings N having chars from 3 to 5.

For multi language (arabic, Ukrainian) you Must use this

var regex = /^([a-zA-Z0-9_-\u0600-\u065f\u066a-\u06EF\u06fa-\u06ff\ufb8a\u067e\u0686\u06af\u0750-\u077f\ufb50-\ufbc1\ufbd3-\ufd3f\ufd50-\ufd8f\ufd92-\ufdc7\ufe70-\ufefc\uFDF0-\uFDFD]+){3,5}$/;  regex.test('?????');

Other wise the below is for English Alphannumeric only

/^([a-zA-Z0-9_-]){3,5}$/

P.S the above dose not accept special characters

one final thing the above dose not take space as test it will fail if there is space if you want space then add after the 0-9\s

\s

And if you want to check lenght of all string add dot .

var regex = /^([a-zA-Z0-9\s@,!=%$#&_-\u0600-\u065f\u066a-\u06EF\u06fa-\u06ff\ufb8a\u067e\u0686\u06af\u0750-\u077f\ufb50-\ufbc1\ufbd3-\ufd3f\ufd50-\ufd8f\ufd92-\ufdc7\ufe70-\ufefc\uFDF0-\uFDFD]).{1,30}$/;

How do you specify a different port number in SQL Management Studio?

Another way is to setup an alias in Config Manager. Then simply type that alias name when you want to connect. This makes it much easier and is more prefereable when you have to manage several servers/instances and/or servers on multiple ports and/or multiple protocols. Give them friendly names and it becomes much easier to remember them.

Should I use the Reply-To header when sending emails as a service to others?

I tested dkarp's solution with gmail and it was filtered to spam. Use the Reply-To header instead (or in addition, although gmail apparently doesn't need it). Here's how linkedin does it:

Sender: [email protected]
From: John Doe via LinkedIn <[email protected]>
Reply-To: John Doe <[email protected]>
To: My Name <[email protected]>

Once I switched to this format, gmail is no longer filtering my messages as spam.

Angular2 disable button

Using ngClass to disabled the button for invalid form is not good practice in Angular2 when its providing inbuilt features to enable and disable the button if form is valid and invalid respectively without doing any extra efforts/logic.

[disabled] will do all thing like if form is valid then it will be enabled and if form is invalid then it will be disabled automatically.

See Example:

<form (ngSubmit)="f.form.valid" #f="ngForm" novalidate>
<input type="text" placeholder="Name" [(ngModel)]="txtName" name="txtname" #textname="ngModel" required>
<input type="button" class="mdl-button" [disabled]="!f.form.valid" (click)="onSave()" name="">

How to sort List of objects by some property

Using Comparator

For Example:

class Score {

    private String name;
    private List<Integer> scores;
    // +accessor methods
}

    Collections.sort(scores, new Comparator<Score>() {

        public int compare(Score o1, Score o2) {
            // compare two instance of `Score` and return `int` as result.
            return o2.getScores().get(0).compareTo(o1.getScores().get(0));
        }
    });

With Java 8 onwards, you can simply use lambda expression to represent Comparator instance.

Collections.sort(scores, (s1, s2) -> { /* compute and return int */ });

Passing references to pointers in C++

Your function expects a reference to an actual string pointer in the calling scope, not an anonymous string pointer. Thus:

string s;
string* _s = &s;
myfunc(_s);

should compile just fine.

However, this is only useful if you intend to modify the pointer you pass to the function. If you intend to modify the string itself you should use a reference to the string as Sake suggested. With that in mind it should be more obvious why the compiler complains about you original code. In your code the pointer is created 'on the fly', modifying that pointer would have no consequence and that is not what is intended. The idea of a reference (vs. a pointer) is that a reference always points to an actual object.

Spring-Boot: How do I set JDBC pool properties like maximum number of connections?

At the current version of Spring-Boot (1.4.1.RELEASE) , each pooling datasource implementation has its own prefix for properties.

For instance, if you are using tomcat-jdbc:

spring.datasource.tomcat.max-wait=10000

You can find the explanation out here

spring.datasource.max-wait=10000

this have no effect anymore.

how to stop a loop arduino

The three options that come to mind:

1st) End void loop() with while(1)... or equally as good... while(true)

void loop(){
    //the code you want to run once here, 
    //e.g., If (blah == blah)...etc.

    while(1)        //last line of main loop
}

This option runs your code once and then kicks the Ard into an endless "invisible" loop. Perhaps not the nicest way to go, but as far as outside appearances, it gets the job done.
The Ard will continue to draw current while it spins itself in an endless circle... perhaps one could set up a sort of timer function that puts the Ard to sleep after so many seconds, minutes, etc., of looping... just a thought... there are certainly various sleep libraries out there... see e.g., Monk, Programming Arduino: Next Steps, pgs., 85-100 for further discussion of such.

2nd) Create a "stop main loop" function with a conditional control structure that makes its initial test fail on a second pass.
This often requires declaring a global variable and having the "stop main loop" function toggle the value of the variable upon termination. E.g.,

boolean stop_it = false;         //global variable

void setup(){
    Serial.begin(9600); 
    //blah...
}

boolean stop_main_loop(){        //fancy stop main loop function

    if(stop_it == false){   //which it will be the first time through

        Serial.println("This should print once.");

       //then do some more blah....you can locate all the
       // code you want to run once here....eventually end by 
       //toggling the "stop_it" variable ... 
    }
    stop_it = true; //...like this
    return stop_it;   //then send this newly updated "stop_it" value
                     // outside the function
}

void loop{ 

    stop_it = stop_main_loop();     //and finally catch that updated 
                                    //value and store it in the global stop_it 
                                    //variable, effectively 
                                    //halting the loop  ...
}

Granted, this might not be especially pretty, but it also works.
It kicks the Ard into another endless "invisible" loop, but this time it's a case of repeatedly checking the if(stop_it == false) condition in stop_main_loop() which of course fails to pass every time after the first time through.

3rd) One could once again use a global variable but use a simple if (test == blah){} structure instead of a fancy "stop main loop" function.

boolean start = true;                  //global variable

void setup(){

      Serial.begin(9600);
}

void loop(){

      if(start == true){           //which it will be the first time through



           Serial.println("This should print once.");       

           //the code you want to run once here, 
           //e.g., more If (blah == blah)...etc.

     }

start = false;                //toggle value of global "start" variable
                              //Next time around, the if test is sure to fail.
}

There are certainly other ways to "stop" that pesky endless main loop but these three as well as those already mentioned should get you started.

Why aren't python nested functions called closures?

def nested1(num1): 
    print "nested1 has",num1
    def nested2(num2):
        print "nested2 has",num2,"and it can reach to",num1
        return num1+num2    #num1 referenced for reading here
    return nested2

Gives:

In [17]: my_func=nested1(8)
nested1 has 8

In [21]: my_func(5)
nested2 has 5 and it can reach to 8
Out[21]: 13

This is an example of what a closure is and how it can be used.

DisplayName attribute from Resources?

public class Person
{
    // Before C# 6.0
    [Display(Name = "Age", ResourceType = typeof(Testi18n.Resource))]
    public string Age { get; set; }

    // After C# 6.0
    // [Display(Name = nameof(Resource.Age), ResourceType = typeof(Resource))]
}
  1. Define ResourceType of the attribute so it looks for a resource
  2. Define Name of the attribute which is used for the key of resource, after C# 6.0, you can use nameof for strong typed support instead of hard coding the key.

  3. Set the culture of current thread in the controller.

Resource.Culture = CultureInfo.GetCultureInfo("zh-CN");

  1. Set the accessibility of the resource to public

  2. Display the label in cshtml like this

@Html.DisplayNameFor(model => model.Age)

How do I loop through or enumerate a JavaScript object?

via prototype with forEach() which should skip the prototype chain properties:

Object.prototype.each = function(f) {
    var obj = this
    Object.keys(obj).forEach( function(key) { 
        f( key , obj[key] ) 
    });
}


//print all keys and values
var obj = {a:1,b:2,c:3}
obj.each(function(key,value) { console.log(key + " " + value) });
// a 1
// b 2
// c 3