Programs & Examples On #Narrator

Narrator is a screen reader that reads text on the screen aloud

Number of lines in a file in Java

Only way to know how many lines there are in file is to count them. You can of course create a metric from your data giving you an average length of one line and then get the file size and divide that with avg. length but that won't be accurate.

Use :hover to modify the css of another class?

There are two approaches you can take, to have a hovered element affect (E) another element (F):

  1. F is a child-element of E, or
  2. F is a later-sibling (or sibling's descendant) element of E (in that E appears in the mark-up/DOM before F):

To illustrate the first of these options (F as a descendant/child of E):

.item:hover .wrapper {
    color: #fff;
    background-color: #000;
}?

To demonstrate the second option, F being a sibling element of E:

.item:hover ~ .wrapper {
    color: #fff;
    background-color: #000;
}?

In this example, if .wrapper was an immediate sibling of .item (with no other elements between the two) you could also use .item:hover + .wrapper.

JS Fiddle demonstration.

References:

How to make div appear in front of another?

Use the CSS z-index property. Elements with a greater z-index value are positioned in front of elements with smaller z-index values.

Note that for this to work, you also need to set a position style (position:absolute, position:relative, or position:fixed) on both/all of the elements you want to order.

Check if process returns 0 with batch file

This is not exactly the answer to the question, but I end up here every time I want to find out how to get my batch file to exit with and error code when a process returns an nonzero code.

So here is the answer to that:

if %ERRORLEVEL% NEQ 0 exit %ERRORLEVEL%

Why should I use an IDE?

It depends highly on what you're doing and what language you're doing it in. Personally, I tend to not use an IDE (or "my IDE consists of 3 xterms running vim, one running a database client, and one with a bash prompt or tailing logs", depending on how broadly you define "IDE") for most of my work, but, if I were to find myself developing a platform-native GUI, then I'd reach for a language-appropriate IDE in an instant - IMO, IDEs and graphical form editing are clearly made for each other.

How to Upload Image file in Retrofit 2

Retrofit 2.0 solution

@Multipart
@POST(APIUtils.UPDATE_PROFILE_IMAGE_URL)
public Call<CommonResponse> requestUpdateImage(@PartMap Map<String, RequestBody> map);

and

    Map<String, RequestBody> params = new HashMap<>();

    params.put("newProfilePicture" + "\"; filename=\"" + FilenameUtils.getName(file.getAbsolutePath()), RequestBody.create(MediaType.parse("image/jpg"), file));



 Call<CommonResponse> call = request.requestUpdateImage(params);

you can use
image/jpg image/png image/gif

How to get the string size in bytes?

While sizeof works for this specific type of string:

char str[] = "content";
int charcount = sizeof str - 1; // -1 to exclude terminating '\0'

It does not work if str is pointer (sizeof returns size of pointer, usually 4 or 8) or array with specified length (sizeof will return the byte count matching specified length, which for char type are same).

Just use strlen().

*ngIf and *ngFor on same element causing error

_x000D_
_x000D_
<!-- Since angular2 stable release multiple directives are not supported on a single element(from the docs) still you can use it like below -->_x000D_
_x000D_
_x000D_
<ul class="list-group">_x000D_
                <template ngFor let-item [ngForOf]="stuff" [ngForTrackBy]="trackBy_stuff">_x000D_
                    <li *ngIf="item.name" class="list-group-item">{{item.name}}</li>_x000D_
                </template>_x000D_
   </ul>
_x000D_
_x000D_
_x000D_

Function stoi not declared

#include <algorithm>

Include this and then you can compile it using...

g++ -Wall -std=c++11 test.cpp -o test

You can also add "cd /d %~dp0" as the first line of a .bat file in the same directory as your source file so all you have to do is double click on the .bat file for an "automated" compilation.

Hope this helps!

Python print statement “Syntax Error: invalid syntax”

In Python 3, print is a function, you need to call it like print("hello world").

Session 'app' error while installing APK

This error happens due to Gradle not synced with the project. go to Tools- Android- Sync Project with Gradle files. Then Run it again. On newer Android Studio versions, go to File-> Sync project with gradle files

Counting the number of occurences of characters in a string

if this is a real program and not a study project, then look at using the Apache Commons StringUtils class - particularly the countMatches method.

If it is a study project then keep at it and learn from your exploring :)

NoClassDefFoundError: org/slf4j/impl/StaticLoggerBinder

You have included the dependency for sflj's api, but not the dependency for the implementation of the api, that is a separate jar, you could try slf4j-simple-1.6.1.jar.

Argument of type 'X' is not assignable to parameter of type 'X'

For what it worth, if anyone has this problem only in VSCode, just restart VSCode and it should fix it. Sometimes, Intellisense seems to mess up with imports or types.

Related to Typescript: Argument of type 'RegExpMatchArray' is not assignable to parameter of type 'string'

Converting Go struct to JSON

You need to export the User.name field so that the json package can see it. Rename the name field to Name.

package main

import (
    "fmt"
    "encoding/json"
)

type User struct {
    Name string
}

func main() {
    user := &User{Name: "Frank"}
    b, err := json.Marshal(user)
    if err != nil {
        fmt.Println(err)
        return
    }
    fmt.Println(string(b))
}

Output:

{"Name":"Frank"}

Postgres could not connect to server

For anyone reading this and using Postgres.app, you may need host: localhost in your database.yml. http://postgresapp.com/documentation#toc_3

How do I change the background color with JavaScript?

I would prefer to see the use of a css class here. It avoids having hard to read colors / hex codes in javascript.

document.body.className = className;

Reading a date using DataReader

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;
namespace Library
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\NIKHIL R\Documents\Library.mdf;Integrated Security=True;Connect Timeout=30");
            string query = "INSERT INTO [Table] (BookName , AuthorName , Category) VALUES('" + textBox1.Text.ToString() + "' , '" + textBox2.Text.ToString() + "' , '" + textBox3.Text.ToString() + "')";
            SqlCommand com = new SqlCommand(query, con);
            con.Open();
            com.ExecuteNonQuery();
            con.Close();
            MessageBox.Show("Entry Added");
        }

        private void button3_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\NIKHIL R\Documents\Library.mdf;Integrated Security=True;Connect Timeout=30");
            string query = "SELECT * FROM [TABLE] WHERE BookName='" + textBox1.Text.ToString() + "' OR AuthorName='" + textBox2.Text.ToString() + "'";
            string query1 = "SELECT BookStatus FROM [Table] where BookName='" + textBox1.Text.ToString() + "'";
            string query2 = "SELECT DateOfReturn FROM [Table] where BookName='" + textBox1.Text.ToString() + "'";
            SqlCommand com = new SqlCommand(query, con);
            SqlDataReader dr, dr1,dr2;
            con.Open();
            com.ExecuteNonQuery();
            dr = com.ExecuteReader();

            if (dr.Read())
            {
                con.Close();
                con.Open();
                SqlCommand com1 = new SqlCommand(query1, con);
                com1.ExecuteNonQuery();
                dr1 = com1.ExecuteReader();
                dr1.Read();
                string i = dr1["BookStatus"].ToString();
                if (i =="1" )
                {
                    con.Close();
                    con.Open();
                    SqlCommand com2 = new SqlCommand(query2, con);
                    com2.ExecuteNonQuery();
                    dr2 = com2.ExecuteReader();
                    dr2.Read();


                        MessageBox.Show("This book is already issued\n " + "Book will be available by "+ dr2["DateOfReturn"] );

                }
                else
                {
                    con.Close();
                    con.Open();
                    dr = com.ExecuteReader();
                    dr.Read();
                   MessageBox.Show("BookFound\n" + "BookName=" + dr["BookName"] + "\n AuthorName=" + dr["AuthorName"]);
                }
                con.Close();
            }
            else
            {
                MessageBox.Show("This Book is not available in the library");
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\NIKHIL R\Documents\Library.mdf;Integrated Security=True;Connect Timeout=30");
            string query = "SELECT * FROM [TABLE] WHERE BookName='" + textBox1.Text.ToString() + "'";
            string dateofissue1 = DateTime.Today.ToString("dd-MM-yyyy");
            string dateofreturn = DateTime.Today.AddDays(15).ToString("dd-MM-yyyy");
            string query1 = "update [Table] set BookStatus=1,DateofIssue='"+ dateofissue1 +"',DateOfReturn='"+ dateofreturn +"' where BookName='" + textBox1.Text.ToString() + "'";
            con.Open();
            SqlCommand com = new SqlCommand(query, con);
            SqlDataReader dr;
            com.ExecuteNonQuery();
            dr = com.ExecuteReader();
            if (dr.Read())
            {
                con.Close();
                con.Open();
                string dateofissue = DateTime.Today.ToString("dd-MM-yyyy");
                textBox4.Text = dateofissue;
                textBox5.Text = DateTime.Today.AddDays(15).ToString("dd-MM-yyyy");
                SqlCommand com1 = new SqlCommand(query1, con);
                com1.ExecuteNonQuery();
                MessageBox.Show("Book Isuued");
            }
            else
            {
                MessageBox.Show("Book Not Found");
            }
            con.Close();

        }

        private void button4_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\NIKHIL R\Documents\Library.mdf;Integrated Security=True;Connect Timeout=30");
            string query1 = "update [Table] set BookStatus=0 WHERE BookName='"+textBox1.Text.ToString()+"'";
            con.Open();
            SqlCommand com = new SqlCommand(query1, con);
            com.ExecuteNonQuery();
            string today = DateTime.Today.ToString("dd-MM-yyyy");
            DateTime today1 = DateTime.Parse(today);
            string query = "SELECT dateofReturn from [Table] where BookName='" + textBox1.Text.ToString() + "'";
            con.Close();
            con.Open();
            SqlDataReader dr;
            SqlCommand cmd = new SqlCommand(query, con);
            cmd.ExecuteNonQuery();
            dr = cmd.ExecuteReader();
            dr.Read();
            string DOR = dr["DateOfReturn"].ToString();
            DateTime dor = DateTime.Parse(DOR);
            TimeSpan ts = today1.Subtract(dor);
            string query2 = "update [Table] set DateOfIssue=NULL, DateOfReturn=NULL WHERE BookName='" + textBox1.Text.ToString() + "'";
            con.Close();
            con.Open();
            SqlCommand com2 = new SqlCommand(query2, con);
            com2.ExecuteNonQuery();
            int x = int.Parse(ts.Days.ToString());
            if (x > 0)
            {
                int fine = x * 5;
                textBox6.Text = fine.ToString();
                MessageBox.Show("Book Received\nFine=" + fine);
            }
            else
            {
                textBox6.Text = "0";
                MessageBox.Show("Book Received\nFine=0");
            }
                con.Close();
        }
    }
}

moment.js, how to get day of week number

From the docs page, notice they have these helpful headers

http://momentjs.com/docs/#/get-set/weekday/
(I didn't see them at first)

With header sections for:

  • Date of Month
  • Day of Week
  • etc

.

  var now = moment();
  var day  = now.day();
  var date = now.date(); // Number

What do "branch", "tag" and "trunk" mean in Subversion repositories?

Now that's the thing about software development, there's no consistent knowledge about anything, everybody seems to have it their own way, but that's because it is a relatively young discipline anyway.

Here's my plain simple way,

trunk - The trunk directory contains the most current, approved, and merged body of work. Contrary to what many have confessed, my trunk is only for clean, neat, approved work, and not a development area, but rather a release area.

At some given point in time when the trunk seems all ready to release, then it is tagged and released.

branches - The branches directory contains experiments and ongoing work. Work under a branch stays there until is approved to be merged into the trunk. For me, this is the area where all the work is done.

For example: I can have an iteration-5 branch for a fifth round of development on the product, maybe a prototype-9 branch for a ninth round of experimenting, and so on.

tags - The tags directory contains snapshots of approved branches and trunk releases. Whenever a branch is approved to merge into the trunk, or a release is made of the trunk, a snapshot of the approved branch or trunk release is made under tags.

I suppose with tags I can jump back and forth through time to points interest quite easily.

Is it possible to set an object to null?

An object of a class cannot be set to NULL; however, you can set a pointer (which contains a memory address of an object) to NULL.

Example of what you can't do which you are asking:

Cat c;
c = NULL;//Compiling error

Example of what you can do:

Cat c;
//Set p to hold the memory address of the object c
Cat *p = &c;
//Set p to hold NULL
p = NULL;

Checking character length in ruby

I think you could just use the String#length method...

http://ruby-doc.org/core-1.9.3/String.html#method-i-length

Example:

text = 'The quick brown fox jumps over the lazy dog.'
puts text.length > 25 ? 'Too many characters' : 'Accepted'

Why do I always get the same sequence of random numbers with rand()?

call srand(sameSeed) before calling rand(). More details here.

How do I find the current executable filename?

This one was not included:

System.Windows.Forms.Application.ExecutablePath;

~Joe

How to set Status Bar Style in Swift 3

Swift 5

To add more detail for PRAVEEN's answer at https://stackoverflow.com/a/40066798/2082851, I would like to provide my implementation. It supports the flexibility to customize each controller's status bar.

In overall, we will create a BaseViewController which handle the statusBarStyle property in all the case. When you create a new controller, make it as subclass of this base controller.

Whenever you want to change the status appearance, you only need to update this property. The status bar style will be updated immediately.

Implementation

class BaseViewController: UIViewController {

    var statusBarStyle: UIStatusBarStyle = .default {
        didSet {
            setNeedsStatusBarAppearanceUpdate()
        }
    }

    override var preferredStatusBarStyle: UIStatusBarStyle {
        return statusBarStyle
    }
}

Demo

class ViewController: BaseViewController, UIScrollViewDelegate {

    let scrollView = UIScrollView()
    ... 
    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        UIView.animate(withDuration: 0.3) {
            if scrollView.contentOffset.y > 30 {
                self.statusBarStyle = .darkContent
            } else {
                self.statusBarStyle = .lightContent
            }
        }
    }
}

enter image description here

2. UINavigationController

For UINavigationController, it is a special case, which you can follow either solutions:

Solution A: Override with message dispatch

Since UINavigationController is an NSObject and inherit from ObjectiveC, its methods are message dispatch and you can override them.

extension UINavigationController {
   open override var preferredStatusBarStyle: UIStatusBarStyle {
      return topViewController?.preferredStatusBarStyle ?? .default
   }
}

Solution B: Create UINavigationController subclass

If you already have a custom UINavigationController (which usually need to control more requirements), this is the best solution for you.

final class NavigationController: UINavigationController {
    override var preferredStatusBarStyle: UIStatusBarStyle {
        return topViewController?.preferredStatusBarStyle ?? super.preferredStatusBarStyle
    }
}

Finding the average of a list

Instead of casting to float, you can add 0.0 to the sum:

def avg(l):
    return sum(l, 0.0) / len(l)

Extreme wait-time when taking a SQL Server database offline

In my case I had looked at some tables in the DB prior to executing this action. My user account was holding an active connection to this DB in SSMS. Once I disconnected from the server in SSMS (leaving the 'Take database offline' dialog box open) the operation succeeded.

Is there a rule-of-thumb for how to divide a dataset into training and validation sets?

There are two competing concerns: with less training data, your parameter estimates have greater variance. With less testing data, your performance statistic will have greater variance. Broadly speaking you should be concerned with dividing data such that neither variance is too high, which is more to do with the absolute number of instances in each category rather than the percentage.

If you have a total of 100 instances, you're probably stuck with cross validation as no single split is going to give you satisfactory variance in your estimates. If you have 100,000 instances, it doesn't really matter whether you choose an 80:20 split or a 90:10 split (indeed you may choose to use less training data if your method is particularly computationally intensive).

Assuming you have enough data to do proper held-out test data (rather than cross-validation), the following is an instructive way to get a handle on variances:

  1. Split your data into training and testing (80/20 is indeed a good starting point)
  2. Split the training data into training and validation (again, 80/20 is a fair split).
  3. Subsample random selections of your training data, train the classifier with this, and record the performance on the validation set
  4. Try a series of runs with different amounts of training data: randomly sample 20% of it, say, 10 times and observe performance on the validation data, then do the same with 40%, 60%, 80%. You should see both greater performance with more data, but also lower variance across the different random samples
  5. To get a handle on variance due to the size of test data, perform the same procedure in reverse. Train on all of your training data, then randomly sample a percentage of your validation data a number of times, and observe performance. You should now find that the mean performance on small samples of your validation data is roughly the same as the performance on all the validation data, but the variance is much higher with smaller numbers of test samples

Check string length in PHP

$message is propably not a string at all, but an array. Use $message[0] to access the first element.

SQL Query - Concatenating Results into One String

If you're on SQL Server 2005 or up, you can use this FOR XML PATH & STUFF trick:

DECLARE @CodeNameString varchar(100)

SELECT 
   @CodeNameString = STUFF( (SELECT ',' + CodeName 
                             FROM dbo.AccountCodes 
                             ORDER BY Sort
                             FOR XML PATH('')), 
                            1, 1, '')

The FOR XML PATH('') basically concatenates your strings together into one, long XML result (something like ,code1,code2,code3 etc.) and the STUFF puts a "nothing" character at the first character, e.g. wipes out the "superfluous" first comma, to give you the result you're probably looking for.

UPDATE: OK - I understand the comments - if your text in the database table already contains characters like <, > or &, then my current solution will in fact encode those into &lt;, &gt;, and &amp;.

If you have a problem with that XML encoding - then yes, you must look at the solution proposed by @KM which works for those characters, too. One word of warning from me: this approach is a lot more resource and processing intensive - just so you know.

Calling dynamic function with dynamic number of parameters

Your code only works for global functions, ie. members of the window object. To use it with arbitrary functions, pass the function itself instead of its name as a string:

function dispatch(fn, args) {
    fn = (typeof fn == "function") ? fn : window[fn];  // Allow fn to be a function object or the name of a global function
    return fn.apply(this, args || []);  // args is optional, use an empty array by default
}

function f1() {}

function f2() {
    var f = function() {};
    dispatch(f, [1, 2, 3]);
}

dispatch(f1, ["foobar"]);
dispatch("f1", ["foobar"]);

f2();  // calls inner-function "f" in "f2"
dispatch("f", [1, 2, 3]);  // doesn't work since "f" is local in "f2"

Why Choose Struct Over Class?

Some advantages:

  • automatically threadsafe due to not being shareable
  • uses less memory due to no isa and refcount (and in fact is stack allocated generally)
  • methods are always statically dispatched, so can be inlined (though @final can do this for classes)
  • easier to reason about (no need to "defensively copy" as is typical with NSArray, NSString, etc...) for the same reason as thread safety

Uncaught TypeError: Cannot read property 'value' of null

Add a check

if (document.getElementById('cal_preview') != null) {
    str = document.getElementById("cal_preview").value;
}

right click context menu for datagridview

  • Put a context menu on your form, name it, set captions etc. using the built-in editor
  • Link it to your grid using the grid property ContextMenuStrip
  • For your grid, create an event to handle CellContextMenuStripNeeded
  • The Event Args e has useful properties e.ColumnIndex, e.RowIndex.

I believe that e.RowIndex is what you are asking for.

Suggestion: when user causes your event CellContextMenuStripNeeded to fire, use e.RowIndex to get data from your grid, such as the ID. Store the ID as the menu event's tag item.

Now, when user actually clicks your menu item, use the Sender property to fetch the tag. Use the tag, containing your ID, to perform the action you need.

Decorators with parameters?

This is a template for a function decorator that does not require () if no parameters are to be given:

import functools


def decorator(x_or_func=None, *decorator_args, **decorator_kws):
    def _decorator(func):
        @functools.wraps(func)
        def wrapper(*args, **kws):
            if 'x_or_func' not in locals() \
                    or callable(x_or_func) \
                    or x_or_func is None:
                x = ...  # <-- default `x` value
            else:
                x = x_or_func
            return func(*args, **kws)

        return wrapper

    return _decorator(x_or_func) if callable(x_or_func) else _decorator

an example of this is given below:

def multiplying(factor_or_func=None):
    def _decorator(func):
        @functools.wraps(func)
        def wrapper(*args, **kwargs):
            if 'factor_or_func' not in locals() \
                    or callable(factor_or_func) \
                    or factor_or_func is None:
                factor = 1
            else:
                factor = factor_or_func
            return factor * func(*args, **kwargs)
        return wrapper
    return _decorator(factor_or_func) if callable(factor_or_func) else _decorator


@multiplying
def summing(x): return sum(x)

print(summing(range(10)))
# 45


@multiplying()
def summing(x): return sum(x)

print(summing(range(10)))
# 45


@multiplying(10)
def summing(x): return sum(x)

print(summing(range(10)))
# 450

Filtering DataGridView without changing datasource

I have a clearer proposal on automatic search in a DataGridView

this is an example

private void searchTb_TextChanged(object sender, EventArgs e)
    {
        try
        {
            (lecteurdgview.DataSource as DataTable).DefaultView.RowFilter = String.IsNullOrEmpty(searchTb.Text) ?
                "lename IS NOT NULL" :
                String.Format("lename LIKE '{0}' OR lecni LIKE '{1}' OR ledatenais LIKE '{2}' OR lelieu LIKE '{3}'", searchTb.Text, searchTb.Text, searchTb.Text, searchTb.Text);
        }
        catch (Exception ex) {
            MessageBox.Show(ex.StackTrace);
        }
    }

In NetBeans how do I change the Default JDK?

If I remember correctly, you'll need to set the netbeans_jdkhome property in your netbeans config file. Should be in your etc/netbeans.conf file.

How to refresh table contents in div using jquery/ajax

You can load HTML page partial, in your case is everything inside div#mytable.

setTimeout(function(){
   $( "#mytable" ).load( "your-current-page.html #mytable" );
}, 2000); //refresh every 2 seconds

more information read this http://api.jquery.com/load/

Update Code (if you don't want it auto-refresh)

<button id="refresh-btn">Refresh Table</button>

<script>
$(document).ready(function() {

   function RefreshTable() {
       $( "#mytable" ).load( "your-current-page.html #mytable" );
   }

   $("#refresh-btn").on("click", RefreshTable);

   // OR CAN THIS WAY
   //
   // $("#refresh-btn").on("click", function() {
   //    $( "#mytable" ).load( "your-current-page.html #mytable" );
   // });


});
</script>

Why is this jQuery click function not working?

Be sure there is nothing on your button (such a div or a trasparent img) that keeps from clicking the button. It sounds stupid, but sometimes we think that jQuery is not working and all that stuffs and the problem is on the positioning of DOM elements.

Correct way to pause a Python program

I think that the best way to stop the execution is the time.sleep() function.

If you need to suspend the execution only in certain cases you can simply implement an if statement like this:

if somethinghappen:
    time.sleep(seconds)

You can leave the else branch empty.

Using async/await with a forEach loop

A simple drop-in solution for replacing a forEach() await loop that is not working is replacing forEach with map and adding Promise.all( to the beginning.

For example:

await y.forEach(async (x) => {

to

await Promise.all(y.map(async (x) => {

An extra ) is needed at the end.

In Gradle, is there a better way to get Environment Variables?

In android gradle 0.4.0 you can just do:

println System.env.HOME

classpath com.android.tools.build:gradle-experimental:0.4.0

How to check a string against null in java?

Use TextUtils Method if u working in Android.

TextUtils.isEmpty(str) : Returns true if the string is null or 0-length. Parameters: str the string to be examined Returns: true if str is null or zero length

  if(TextUtils.isEmpty(str)) {
        // str is null or lenght is 0
    }

Below is source code of this method.You can use direclty.

 /**
     * Returns true if the string is null or 0-length.
     * @param str the string to be examined
     * @return true if str is null or zero length
     */
    public static boolean isEmpty(CharSequence str) {
        if (str == null || str.length() == 0)
            return true;
        else
            return false;
    }

Adding an HTTP Header to the request in a servlet filter

You'll have to use an HttpServletRequestWrapper:

public void doFilter(final ServletRequest request, final ServletResponse response, final FilterChain chain) throws IOException, ServletException {
    final HttpServletRequest httpRequest = (HttpServletRequest) request;
    HttpServletRequestWrapper wrapper = new HttpServletRequestWrapper(httpRequest) {
        @Override
        public String getHeader(String name) {
            final String value = request.getParameter(name);
            if (value != null) {
                return value;
            }
            return super.getHeader(name);
        }
    };
    chain.doFilter(wrapper, response);
}

Depending on what you want to do you may need to implement other methods of the wrapper like getHeaderNames for instance. Just be aware that this is trusting the client and allowing them to manipulate any HTTP header. You may want to sandbox it and only allow certain header values to be modified this way.

How do I fix 'ImportError: cannot import name IncompleteRead'?

Simply running easy_install -U pip resolved my problem.

Trouble Connecting to sql server Login failed. "The login is from an untrusted domain and cannot be used with Windows authentication"

If you using windows authentication make sure that password of the user hasn't expired. An expired password can explain this error. This was the problem in my case.

JFrame background image

You can do:

setContentPane(new JLabel(new ImageIcon("resources/taverna.jpg")));

At first line of the Jframe class constructor, that works fine for me

docker: executable file not found in $PATH

I found the same problem. I did the following:

docker run -ti devops -v /tmp:/tmp /bin/bash

When I change it to

docker run -ti -v /tmp:/tmp devops /bin/bash

it works fine.

Convert Decimal to Varchar

If you are using SQL Server 2012, 2014 or newer, use the Format Function instead:

select Format( decimalColumnName ,'FormatString','en-US' )

Review the Microsoft topic and .NET format syntax for how to define the format string.

An example for this question would be:

select Format( MyDecimalColumn ,'N','en-US' )

Sum values in foreach loop php

In your case IF you want to go with foreach loop than

$sum = 0;
foreach($group as $key => $value) {
   $sum += $value; 
}
echo $sum;

But if you want to go with direct sum of array than look on below for your solution :

$total = array_sum($group);

for only sum of array looping is time wasting.

http://php.net/manual/en/function.array-sum.php

array_sum — Calculate the sum of values in an array

<?php
$a = array(2, 4, 6, 8);
echo "sum(a) = " . array_sum($a) . "\n";

$b = array("a" => 1.2, "b" => 2.3, "c" => 3.4);
echo "sum(b) = " . array_sum($b) . "\n";
?>

The above example will output:

sum(a) = 20
sum(b) = 6.9

python JSON only get keys in first level

for key in data.keys():
    print key

How to read lines of a file in Ruby

Your first file has Mac Classic line endings (that’s "\r" instead of the usual "\n"). Open it with

File.open('foo').each(sep="\r") do |line|

to specify the line endings.

Java: Difference between the setPreferredSize() and setSize() methods in components

setSize will resize the component to the specified size.

setPreferredSize sets the preferred size. The component may not actually be this size depending on the size of the container it's in, or if the user re-sized the component manually.

insert data into database with codeigniter

Check your controller:

function order()
    $OrderLines = $this->input->post('orderlines');
    $CustomerName = $this->input->post('customer');
    $data = array(
        'OrderLines' => $OrderLines,
        'CustomerName' =>$CustomerName
    ); 

    $this->db->insert('Customer_Orders', $data);
}

iText - add content to existing PDF file

iText has more than one way of doing this. The PdfStamper class is one option. But I find the easiest method is to create a new PDF document then import individual pages from the existing document into the new PDF.

// Create output PDF
Document document = new Document(PageSize.A4);
PdfWriter writer = PdfWriter.getInstance(document, outputStream);
document.open();
PdfContentByte cb = writer.getDirectContent();

// Load existing PDF
PdfReader reader = new PdfReader(templateInputStream);
PdfImportedPage page = writer.getImportedPage(reader, 1); 

// Copy first page of existing PDF into output PDF
document.newPage();
cb.addTemplate(page, 0, 0);

// Add your new data / text here
// for example...
document.add(new Paragraph("my timestamp")); 

document.close();

This will read in a PDF from templateInputStream and write it out to outputStream. These might be file streams or memory streams or whatever suits your application.

Random number between 0 and 1 in python

random.random() does exactly that

>>> import random
>>> for i in range(10):
...     print(random.random())
... 
0.908047338626
0.0199900075962
0.904058545833
0.321508119045
0.657086320195
0.714084413092
0.315924955063
0.696965958019
0.93824013683
0.484207425759

If you want really random numbers, and to cover the range [0, 1]:

>>> import os
>>> int.from_bytes(os.urandom(8), byteorder="big") / ((1 << 64) - 1)
0.7409674234050893

Add ArrayList to another ArrayList in java

The problem you have is caused that you use the same ArrayList NodeList over all iterations in main for loop. Each iterations NodeList is enlarged by new elements.

  1. After first loop, NodeList has 5 elements (PropertyStart,a,b,c,PropertyEnd) and list has 1 element (NodeList: (PropertyStart,a,b,c,PropertyEnd))

  2. After second loop NodeList has 10 elements (PropertyStart,a,b,c,PropertyEnd,PropertyStart,d,e,f,PropertyEnd) and list has 2 elements (NodeList (with 10 elements), NodeList (with 10 elements))

To get you expectations you must replace

NodeList.addAll(nodes);
list.add(NodeList)

by

List childrenList = new ArrayList(nodes);
list.add(childrenList);

PS. Your code is not readable, keep Java code conventions to have readble code. For example is hard to recognize if NodeList is a class or object

Configure WAMP server to send email

Configuring a working email client from localhost is quite a chore, I have spent hours of frustration attempting it. I'm sure someone more experienced may be able to help, or they may perhaps agree with me.

If you just want to test, here is a great tool for testing mail locally, that requires almost no configuration:

http://www.toolheap.com/test-mail-server-tool/

It worked right off the bat for me, hope this helps you.

How to change CSS using jQuery?

When you are using Multiple css property with jQuery then you must use the curly Brace in starting and in the end. You are missing the ending curly brace.

function init() {
 $("h1").css("backgroundColor", "yellow");

 $("#myParagraph").css({"background-color":"black","color":"white"});

 $(".bordered").css("border", "1px solid black");
}

You can have a look at this jQuery CSS Selector tutorial.

How do I convert 2018-04-10T04:00:00.000Z string to DateTime?

Update: Using DateTimeFormat, introduced in java 8:

The idea is to define two formats: one for the input format, and one for the output format. Parse with the input formatter, then format with the output formatter.

Your input format looks quite standard, except the trailing Z. Anyway, let's deal with this: "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'". The trailing 'Z' is the interesting part. Usually there's time zone data here, like -0700. So the pattern would be ...Z, i.e. without apostrophes.

The output format is way more simple: "dd-MM-yyyy". Mind the small y -s.

Here is the example code:

DateTimeFormatter inputFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.ENGLISH);
DateTimeFormatter outputFormatter = DateTimeFormatter.ofPattern("dd-MM-yyy", Locale.ENGLISH);
LocalDate date = LocalDate.parse("2018-04-10T04:00:00.000Z", inputFormatter);
String formattedDate = outputFormatter.format(date);
System.out.println(formattedDate); // prints 10-04-2018

Original answer - with old API SimpleDateFormat

SimpleDateFormat inputFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
SimpleDateFormat outputFormat = new SimpleDateFormat("dd-MM-yyyy");
Date date = inputFormat.parse("2018-04-10T04:00:00.000Z");
String formattedDate = outputFormat.format(date);
System.out.println(formattedDate); // prints 10-04-2018

Is embedding background image data into CSS as Base64 good or bad practice?

Bringing a bit for users of Sublime Text 2, there is a plugin that gives the base64 code we load the images in the ST.

Called Image2base64: https://github.com/tm-minty/sublime-text-2-image2base64

PS: Never save this file generated by the plugin because it would overwrite the file and would destroy.

How to access PHP session variables from jQuery function in a .js file?

This is strictly not speaking using jQuery, but I have found this method easier than using jQuery. There are probably endless methods of achieving this and many clever ones here, but not all have worked for me. However the following method has always worked and I am passing it one in case it helps someone else.

Three javascript libraries are required, createCookie, readCookie and eraseCookie. These libraries are not mine but I began using them about 5 years ago and don't know their origin.

createCookie = function(name, value, days) {
if (days) {
    var date = new Date();
    date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
    var expires = "; expires=" + date.toGMTString();
}
else var expires = "";

document.cookie = name + "=" + value + expires + "; path=/";
}

readCookie = function (name) {
var nameEQ = name + "=";
var ca = document.cookie.split(';');
for (var i = 0; i < ca.length; i++) {
    var c = ca[i];
    while (c.charAt(0) == ' ') c = c.substring(1, c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);
}
return null;
}
eraseCookie = function (name) {
   createCookie(name, "", -1);
}

To call them you need to create a small PHP function, normally as part of your support library, as follows:

<?php
 function createjavaScriptCookie($sessionVarible) {
 $s =  "<script>";
 $s = $s.'createCookie('. '"'. $sessionVarible                 
 .'",'.'"'.$_SESSION[$sessionVarible].'"'. ',"1"'.')';
 $s = $s."</script>";
 echo $s;
}
?>

So to use all you now have to include within your index.php file is

$_SESSION["video_dir"] = "/video_dir/";
createjavaScriptCookie("video_dir");

Now in your javascript library.js you can recover the cookie with the following code:

var videoPath = readCookie("video_dir") +'/'+ video_ID + '.mp4';

I hope this helps.

How can I use Helvetica Neue Condensed Bold in CSS?

You would have to turn your font into a web font as shown in these SO questions:

However, you may run into copyright issues with this: Not every font allows distribution as a web font. Check your font license to see whether it is allowed.

One of the easiest free and legal ways to use web fonts is Google Web Fonts. However, sadly, they don't have Helvetica Neue in their portfolio.

One of the easiest non-free and legal ways is to purchase the font from a foundry that offers web licenses. I happen to know that the myFonts foundry does this; they even give you a full package with all the JavaScript and CSS pre-prepared. I'm sure other foundries do the same.

Edit: MyFonts have Helvetica neue in Stock, but apparently not with a web license. Check out this list of similar fonts of which some have a web license. Also, Ray Larabie has some nice fonts there, with web licenses, some of them are free.

Count(*) vs Count(1) - SQL Server

In SQL Server, these statements yield the same plans.

Contrary to the popular opinion, in Oracle they do too.

SYS_GUID() in Oracle is quite computation intensive function.

In my test database, t_even is a table with 1,000,000 rows

This query:

SELECT  COUNT(SYS_GUID())
FROM    t_even

runs for 48 seconds, since the function needs to evaluate each SYS_GUID() returned to make sure it's not a NULL.

However, this query:

SELECT  COUNT(*)
FROM    (
        SELECT  SYS_GUID()
        FROM    t_even
        )

runs for but 2 seconds, since it doen't even try to evaluate SYS_GUID() (despite * being argument to COUNT(*))

href around input type submit

<a href="1.html"><input type="text" class="button_active" value="1"></a>
<a href="2.html"><input type="text" class="button" value="2"></a>
<a href="3.html"><input type="text" class="button" value="3"></a>

Try that. Unless you truly need to stick with the type as submit, then what I provided should work. If you are going to stick with submit, then everything mentioned above is correct, it makes no sense.

Remove spaces from a string in VB.NET

This will remove spaces only, matches the SQL functionality of rtrim(ltrim(myString))

Dim charstotrim() As Char = {" "c}
myString = myString .Trim(charstotrim) 

Unable to load script.Make sure you are either running a Metro server or that your bundle 'index.android.bundle' is packaged correctly for release

You can try the following:

Add this line on your AndroidManifest.xml

<application
[...]
android:usesCleartextTraffic="true"
/>
[...]
</application>

Hidden features of Windows batch files

This batch file works both with simple files as well as directories as command line parameters (you can mix them in any order). The loop runs the command ('echo' in this example) on any specified file, if a parameter is a directory it runs the command recursively on each file in it.

@echo off
for /f "delims=" %%f in ('dir %* /a-d /b /s') do echo %%f

Select row and element in awk

To expand on Dennis's answer, use awk's -v option to pass the i and j values:

# print the j'th field of the i'th line
awk -v i=5 -v j=3 'FNR == i {print $j}'

How to make a window always stay on top in .Net?

What is the other application you are trying to suppress the visibility of? Have you investigated other ways of achieving your desired effect? Please do so before subjecting your users to such rogue behaviour as you are describing: what you are trying to do sound rather like what certain naughty sites do with browser windows...

At least try to adhere to the rule of Least Surprise. Users expect to be able to determine the z-order of most applications themselves. You don't know what is most important to them, so if you change anything, you should focus on pushing the other application behind everything rather than promoting your own.

This is of course trickier, since Windows doesn't have a particularly sophisticated window manager. Two approaches suggest themselves:

  1. enumerating top-level windows and checking which process they belong to, dropping their z-order if so. (I'm not sure if there are framework methods for these WinAPI functions.)
  2. Fiddling with child process permissions to prevent it from accessing the desktop... but I wouldn't try this until the othe approach failed, as the child process might end up in a zombie state while requiring user interaction.

'cannot open git-upload-pack' error in Eclipse when cloning or pushing git repository

I added -Dhttps.protocols=TLSv1.1,TLSv1.2 to eclipse.ini and it's working. I use java 1.7

SQL query to make all data in a column UPPER CASE?

Permanent:

UPDATE
  MyTable
SET
  MyColumn = UPPER(MyColumn)

Temporary:

SELECT
  UPPER(MyColumn) AS MyColumn
FROM
  MyTable

Create a remote branch on GitHub

Git is supposed to understand what files already exist on the server, unless you somehow made a huge difference to your tree and the new changes need to be sent.

To create a new branch with a copy of your current state

git checkout -b new_branch #< create a new local branch with a copy of your code
git push origin new_branch #< pushes to the server

Can you please describe the steps you did to understand what might have made your repository need to send that much to the server.

print arraylist element?

If you want to print an arraylist with integer numbers, as an example you can use below code.

class Test{
    public static void main(String[] args){
        ArrayList<Integer> arraylist = new ArrayList<Integer>();

        for(int i=0; i<=10; i++){
            arraylist .add(i);
        }
       for (Integer n : arraylist ){
            System.out.println(n);
       }
   }
}

The output is above code:

0
1
2
3
4
5
6
7
8
9
10

How do you get the Git repository's name in some Git repository?

This one works pretty well with git-2.18.2 and can be launched from outside git target repository:

basename -s .git $(git --git-dir=/<project-path>/.git remote get-url origin)

Java synchronized method lock on object, or method?

This might not work as the boxing and autoboxing from Integer to int and viceversa is dependant on JVM and there is high possibility that two different numbers might get hashed to same address if they are between -128 and 127.

Import and insert sql.gz file into database with putty

For an oneliner, on linux or cygwin, you need to do public key authentication on the host, otherwise ssh will be asking for password.


gunzip -c numbers.sql.gz | ssh user@host mysql --user=user_name --password=your_password db_name

Or do port forwarding and connect to the remote mysql using a "local" connection:

ssh -L some_port:host:local_mysql_port user@host

then do the mysql connection on your local machine to localhost:some_port.

The port forwarding will work from putty too, with the similar -L option or you can configure it from the settings panel, somewhere down on the tree.

How to analyse the heap dump using jmap in java

You should use jmap -heap:format=b <process-id> without any paths. So it creates a *.bin file which you can open with jvisualvm.exe (same path as jmap). It's a great tool to open such dump files.

PUT vs. POST in REST

In addition to differences suggested by others, I want to add one more.

In POST method you can send body params in form-data

In PUT method you have to send body params in x-www-form-urlencoded

Header Content-Type:application/x-www-form-urlencoded

According to this, you cannot send files or multipart data in the PUT method

EDIT

The content type "application/x-www-form-urlencoded" is inefficient for sending large quantities of binary data or text containing non-ASCII characters. The content type "multipart/form-data" should be used for submitting forms that contain files, non-ASCII data, and binary data.

Which means if you have to submit

files, non-ASCII data, and binary data

you should use POST method

Php header location redirect not working

I had similar problem... solved by adding ob_start(); and ob_end_flush(); ...

<?php 
ob_start();


require 'engine/vishnuHTML.class.php';
require 'engine/admin/login.class.php';

$html=new vishnuHTML();
 (!isset($_SESSION))?session_start():"";

/* blah bla Code
...........
...........
 */

</div>
</div>
<?php
}



ob_end_flush();
?>

Think of ob_start() as saying "Start remembering everything that would normally be outputted, but don't quite do anything with it yet."

ob_end_clean() or ob_flush(), which either stops saving things and discards whatever was saved, or stops saving and outputs it all at once, respectively.

Time complexity of Euclid's Algorithm

There's a great look at this on the wikipedia article.

It even has a nice plot of complexity for value pairs.

It is not O(a%b).

It is known (see article) that it will never take more steps than five times the number of digits in the smaller number. So the max number of steps grows as the number of digits (ln b). The cost of each step also grows as the number of digits, so the complexity is bound by O(ln^2 b) where b is the smaller number. That's an upper limit, and the actual time is usually less.

MongoDB SELECT COUNT GROUP BY

Additionally if you need to restrict the grouping you can use:

db.events.aggregate( 
    {$match: {province: "ON"}},
    {$group: {_id: "$date", number: {$sum: 1}}}  
)

Deprecated: mysql_connect()

You can remove the warning by adding a '@' before the mysql_connect.

@mysql_connect('localhost','root','');

but as the warning is telling you, use mysqli or PDO since the mysql extension will be removed in the future.

Differences between arm64 and aarch64

It seems that ARM64 was created by Apple and AARCH64 by the others, most notably GNU/GCC guys.

After some googling I found this link:

The LLVM 64-bit ARM64/AArch64 Back-Ends Have Merged

So it makes sense, iPad calls itself ARM64, as Apple is using LLVM, and Edge uses AARCH64, as Android is using GNU GCC toolchain.

Can I load a UIImage from a URL?

AFNetworking provides async image loading into a UIImageView with placeholder support. It also supports async networking for working with APIs in general.

Get the difference between dates in terms of weeks, months, quarters, and years

Here the still lacking lubridate answer (although Gregor's function is built on this package)

The lubridate timespan documentation is very helpful for understanding the difference between periods and duration. I also like the lubridate cheatsheet and this very useful thread

library(lubridate)

dates <- c(dmy('14.01.2013'), dmy('26.03.2014'))

span <- dates[1] %--% dates[2] #creating an interval object

#creating period objects 
as.period(span, unit = 'year') 
#> [1] "1y 2m 12d 0H 0M 0S"
as.period(span, unit = 'month')
#> [1] "14m 12d 0H 0M 0S"
as.period(span, unit = 'day')
#> [1] "436d 0H 0M 0S"

Periods do not accept weeks as units. But you can convert durations to weeks:

as.duration(span)/ dweeks(1)
#makes duration object (in seconds) and divides by duration of a week (in seconds)
#> [1] 62.28571

Created on 2019-11-04 by the reprex package (v0.3.0)

Get index of element as child relative to parent

There's no need to require a big library like jQuery to accomplish this, if you don't want to. To achieve this with built-in DOM manipulation, get a collection of the li siblings in an array, and on click, check the indexOf the clicked element in that array.

_x000D_
_x000D_
const lis = [...document.querySelectorAll('#wizard > li')];_x000D_
lis.forEach((li) => {_x000D_
  li.addEventListener('click', () => {_x000D_
    const index = lis.indexOf(li);_x000D_
    console.log(index);_x000D_
  });_x000D_
});
_x000D_
<ul id="wizard">_x000D_
    <li>Step 1</li>_x000D_
    <li>Step 2</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

Or, with event delegation:

_x000D_
_x000D_
const lis = [...document.querySelectorAll('#wizard li')];_x000D_
document.querySelector('#wizard').addEventListener('click', ({ target }) => {_x000D_
  // Make sure the clicked element is a <li> which is a child of wizard:_x000D_
  if (!target.matches('#wizard > li')) return;_x000D_
  _x000D_
  const index = lis.indexOf(target);_x000D_
  console.log(index);_x000D_
});
_x000D_
<ul id="wizard">_x000D_
    <li>Step 1</li>_x000D_
    <li>Step 2</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

Or, if the child elements may change dynamically (like with a todo list), then you'll have to construct the array of lis on every click, rather than beforehand:

_x000D_
_x000D_
const wizard = document.querySelector('#wizard');_x000D_
wizard.addEventListener('click', ({ target }) => {_x000D_
  // Make sure the clicked element is a <li>_x000D_
  if (!target.matches('li')) return;_x000D_
  _x000D_
  const lis = [...wizard.children];_x000D_
  const index = lis.indexOf(target);_x000D_
  console.log(index);_x000D_
});
_x000D_
<ul id="wizard">_x000D_
    <li>Step 1</li>_x000D_
    <li>Step 2</li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

On design patterns: When should I use the singleton?

Shared resources. Especially in PHP, a database class, a template class, and a global variable depot class. All have to be shared by all modules/classes that are being used throughout the code.

It's a true object usage -> the template class contains the page template that is being built, and it gets shaped, added, changed by modules that are adding to page output. It has to be kept as a single instance so that this can happen, and the same goes for databases. With a shared database singleton, all modules' classes can get access to queries and get them without having to rerun them.

A global variable depot singleton provides you a global, reliable, and easily usable variable depot. It tidies up your code a great lot. Imagine having all configuration values in an array in a singleton like:

$gb->config['hostname']

or having all language values in an array like:

$gb->lang['ENTER_USER']

In the end of running the code for the page, you get, say, a now mature:

$template

Singleton, a $gb singleton that has the lang array for replacing into it, and all output loaded and ready. You just replace them into the keys that are now present in mature template object's page value, and then serve it out to user.

The great advantage of this is you can do ANY post-processing you like on anything. You can pipe all language values to google translate, or another translate service and get them back, and replace them into their places, translated, for example. or, you can replace in page structures, or, content strings, as you want.

Stopping a CSS3 Animation on last frame

The best way seems to put the final state at the main part of css. Like here, i put width to 220px, so that it finally becomes 220px. But starting to 0px;

div.menu-item1 {
  font-size: 20px;
  border: 2px solid #fff;
  width: 220px;
  animation: slide 1s;
  -webkit-animation: slide 1s; /* Safari and Chrome */
}
@-webkit-keyframes slide { /* Safari and Chrome */
  from {width:0px;}
  to {width:220px;}
}  

No connection could be made because the target machine actively refused it 127.0.0.1

The issue disappeared for me when I started Fiddler. Was using it on my machine before having the issue. Probably something with Fiddler being proxy.

mysql data directory location

If you are using macOS {mine 'High Sierra'} and Installed XAMPP

You can find mysql data files;

Go to : /Applications/XAMPP/xamppfiles/var/mysql/

What is the best way to uninstall gems from a rails3 project?

Bundler now has a bundle remove GEM_NAME command (since v1.17.0, 25 October 2018).

How to convert date to string and to date again?

Use DateFormat#parse(String):

Date date = dateFormat.parse("2013-10-22");

Is it possible to change the speed of HTML's <marquee> tag?

_x000D_
_x000D_
<marquee behavior=scroll direction="left" scrollamount="5">Your message here</marquee>
_x000D_
_x000D_
_x000D_

scrollamount controls the speed of text: higher the value higher is the scrolling speed

center image in div with overflow hidden

just make sure how you are using image through css background use backgroud image position like background: url(your image path) no-repeat center center; automatically it wil align center to the screen.

Difference between map and collect in Ruby?

The collect and collect! methods are aliases to map and map!, so they can be used interchangeably. Here is an easy way to confirm that:

Array.instance_method(:map) == Array.instance_method(:collect)
 => true

How to set a value of a variable inside a template code?

Create a template tag:

The app should contain a templatetags directory, at the same level as models.py, views.py, etc. If this doesn’t already exist, create it - don’t forget the __init__.py file to ensure the directory is treated as a Python package.

Create a file named define_action.py inside of the templatetags directory with the following code:

from django import template
register = template.Library()

@register.simple_tag
def define(val=None):
  return val

Note: Development server won’t automatically restart. After adding the templatetags module, you will need to restart your server before you can use the tags or filters in templates.


Then in your template you can assign values to the context like this:

{% load define_action %}
{% if item %}

   {% define "Edit" as action %}

{% else %}

   {% define "Create" as action %}

{% endif %}


Would you like to {{action}} this item?

Why do people hate SQL cursors so much?

Cursors tend to be used by beginning SQL developers in places where set-based operations would be better. Particularly when people learn SQL after learning a traditional programming language, the "iterate over these records" mentality tends to lead people to use cursors inappropriately.

Most serious SQL books include a chapter enjoining the use of cursors; well-written ones make it clear that cursors have their place but shouldn't be used for set-based operations.

There are obviously situations where cursors are the correct choice, or at least A correct choice.

Converting array to list in Java

The problem is that varargs got introduced in Java5 and unfortunately, Arrays.asList() got overloaded with a vararg version too. So Arrays.asList(spam) is understood by the Java5 compiler as a vararg parameter of int arrays.

This problem is explained in more details in Effective Java 2nd Ed., Chapter 7, Item 42.

How to SSH to a VirtualBox guest externally through a host?

You can also use a Bridged Network (or "Bridge Adapter", in newer versions) in network settings. This will put your VM in a VLAN with your machine. So you can just ssh into the VM like this.

ssh user@IP_OF_VM

JQuery, select first row of table

jQuery is not necessary, you can use only javascript.

<table id="table">
  <tr>...</tr>
  <tr>...</tr>
  <tr>...</tr>
   ......
  <tr>...</tr>
</table>

The table object has a collection of all rows.

var myTable = document.getElementById('table');
var rows =  myTable.rows;
var firstRow = rows[0];

CORS Access-Control-Allow-Headers wildcard being ignored?

Quoted from monsur,

The Access-Control-Allow-Headers header does not allow wildcards. It must be an exact match: http://www.w3.org/TR/cors/#access-control-allow-headers-response-header.

So here is my php solution.

if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') {
  $headers=getallheaders();
  @$ACRH=$headers["Access-Control-Request-Headers"];
  header("Access-Control-Allow-Headers: $ACRH");
}

What are the rules for JavaScript's automatic semicolon insertion (ASI)?

First of all you should know which statements are affected by the automatic semicolon insertion (also known as ASI for brevity):

  • empty statement
  • var statement
  • expression statement
  • do-while statement
  • continue statement
  • break statement
  • return statement
  • throw statement

The concrete rules of ASI, are described in the specification §11.9.1 Rules of Automatic Semicolon Insertion

Three cases are described:

  1. When an offending token is encountered that is not allowed by the grammar, a semicolon is inserted before it if:
  • The token is separated from the previous token by at least one LineTerminator.
  • The token is }

e.g.:

    { 1
    2 } 3

is transformed to

    { 1
    ;2 ;} 3;

The NumericLiteral 1 meets the first condition, the following token is a line terminator.
The 2 meets the second condition, the following token is }.

  1. When the end of the input stream of tokens is encountered and the parser is unable to parse the input token stream as a single complete Program, then a semicolon is automatically inserted at the end of the input stream.

e.g.:

    a = b
    ++c

is transformed to:

    a = b;
    ++c;
  1. This case occurs when a token is allowed by some production of the grammar, but the production is a restricted production, a semicolon is automatically inserted before the restricted token.

Restricted productions:

    UpdateExpression :
        LeftHandSideExpression [no LineTerminator here] ++
        LeftHandSideExpression [no LineTerminator here] --
    
    ContinueStatement :
        continue ;
        continue [no LineTerminator here] LabelIdentifier ;
    
    BreakStatement :
        break ;
        break [no LineTerminator here] LabelIdentifier ;
    
    ReturnStatement :
        return ;
        return [no LineTerminator here] Expression ;
    
    ThrowStatement :
        throw [no LineTerminator here] Expression ; 

    ArrowFunction :
        ArrowParameters [no LineTerminator here] => ConciseBody

    YieldExpression :
        yield [no LineTerminator here] * AssignmentExpression
        yield [no LineTerminator here] AssignmentExpression

The classic example, with the ReturnStatement:

    return 
      "something";

is transformed to

    return;
      "something";

How to Set a Custom Font in the ActionBar Title?

Try using This

TextView headerText= new TextView(getApplicationContext());
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(ActionBar.LayoutParams.WRAP_CONTENT, ActionBar.LayoutParams.WRAP_CONTENT);
headerText.setLayoutParams(lp);
headerText.setText("Welcome!");
headerText.setTextSize(20);
headerText.setTextColor(Color.parseColor("#FFFFFF"));
Typeface tf = Typeface.createFromAsset(getAssets(), "fonts/wesfy_regular.ttf");
headerText.setTypeface(tf);
getSupportActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);
getSupportActionBar().setCustomView(headerText);

How to print a double with two decimals in Android?

yourTextView.setText(String.format("Value of a: %.2f", a));

How to parse JSON without JSON.NET library?

You can use the classes found in the System.Json Namespace which were added in .NET 4.5. You need to add a reference to the System.Runtime.Serialization assembly

The JsonValue.Parse() Method parses JSON text and returns a JsonValue:

JsonValue value = JsonValue.Parse(@"{ ""name"":""Prince Charming"", ...");

If you pass a string with a JSON object, you should be able to cast the value to a JsonObject:

using System.Json;


JsonObject result = value as JsonObject;

Console.WriteLine("Name .... {0}", (string)result["name"]);
Console.WriteLine("Artist .. {0}", (string)result["artist"]);
Console.WriteLine("Genre ... {0}", (string)result["genre"]);
Console.WriteLine("Album ... {0}", (string)result["album"]);

The classes are quite similar to those found in the System.Xml.Linq Namespace.

How to change the default encoding to UTF-8 for Apache?

Where all the HTML files are in UTF-8 and don't have meta tags for content type, I was only able to set the needed default for these files to be sent by Apache 2.4 by adding both directives:

AddLanguage ru .html
AddCharset UTF-8 .html

Bootstrap 3 dropdown select

Ive been looking for an nice select dropdown for some time now and I found a good one. So im just gonna leave it here. Its called bootsrap-select

here's the link. check it out. it has editable dropdowns, combo drop downs and more. And its a breeze to add to your project.

If the link dies just search for bootstrap-select by silviomoreto.github.io. This is better because its a normal select tag

Get real path from URI, Android KitKat new storage access framework

Note: This answer addresses part of the problem. For a complete solution (in the form of a library), look at Paul Burke's answer.

You could use the URI to obtain document id, and then query either MediaStore.Images.Media.EXTERNAL_CONTENT_URI or MediaStore.Images.Media.INTERNAL_CONTENT_URI (depending on the SD card situation).

To get document id:

// Will return "image:x*"
String wholeID = DocumentsContract.getDocumentId(uriThatYouCurrentlyHave);

// Split at colon, use second item in the array
String id = wholeID.split(":")[1];

String[] column = { MediaStore.Images.Media.DATA };     

// where id is equal to             
String sel = MediaStore.Images.Media._ID + "=?";

Cursor cursor = getContentResolver().
                          query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, 
                          column, sel, new String[]{ id }, null);

String filePath = "";

int columnIndex = cursor.getColumnIndex(column[0]);

if (cursor.moveToFirst()) {
    filePath = cursor.getString(columnIndex);
}   

cursor.close();

Reference: I'm not able to find the post that this solution is taken from. I wanted to ask the original poster to contribute here. Will look some more tonight.

SQL Server - Return value after INSERT

There are many ways to exit after insert

When you insert data into a table, you can use the OUTPUT clause to return a copy of the data that’s been inserted into the table. The OUTPUT clause takes two basic forms: OUTPUT and OUTPUT INTO. Use the OUTPUT form if you want to return the data to the calling application. Use the OUTPUT INTO form if you want to return the data to a table or a table variable.

DECLARE @MyTableVar TABLE (id INT,NAME NVARCHAR(50));

INSERT INTO tableName
(
  NAME,....
)OUTPUT INSERTED.id,INSERTED.Name INTO @MyTableVar
VALUES
(
   'test',...
)

IDENT_CURRENT: It returns the last identity created for a particular table or view in any session.

SELECT IDENT_CURRENT('tableName') AS [IDENT_CURRENT]

SCOPE_IDENTITY: It returns the last identity from a same session and the same scope. A scope is a stored procedure/trigger etc.

SELECT SCOPE_IDENTITY() AS [SCOPE_IDENTITY];  

@@IDENTITY: It returns the last identity from the same session.

SELECT @@IDENTITY AS [@@IDENTITY];

Named capturing groups in JavaScript regex?

Don't have ECMAScript 2018?

My goal was to make it work as similar as possible to what we are used to with named groups. Whereas in ECMAScript 2018 you can place ?<groupname> inside the group to indicate a named group, in my solution for older javascript, you can place (?!=<groupname>) inside the group to do the same thing. So it's an extra set of parenthesis and an extra !=. Pretty close!

I wrapped all of it into a string prototype function

Features

  • works with older javascript
  • no extra code
  • pretty simple to use
  • Regex still works
  • groups are documented within the regex itself
  • group names can have spaces
  • returns object with results

Instructions

  • place (?!={groupname}) inside each group you want to name
  • remember to eliminate any non-capturing groups () by putting ?: at the beginning of that group. These won't be named.

arrays.js

// @@pattern - includes injections of (?!={groupname}) for each group
// @@returns - an object with a property for each group having the group's match as the value 
String.prototype.matchWithGroups = function (pattern) {
  var matches = this.match(pattern);
  return pattern
  // get the pattern as a string
  .toString()
  // suss out the groups
  .match(/<(.+?)>/g)
  // remove the braces
  .map(function(group) {
    return group.match(/<(.+)>/)[1];
  })
  // create an object with a property for each group having the group's match as the value 
  .reduce(function(acc, curr, index, arr) {
    acc[curr] = matches[index + 1];
    return acc;
  }, {});
};    

usage

function testRegGroups() {
  var s = '123 Main St';
  var pattern = /((?!=<house number>)\d+)\s((?!=<street name>)\w+)\s((?!=<street type>)\w+)/;
  var o = s.matchWithGroups(pattern); // {'house number':"123", 'street name':"Main", 'street type':"St"}
  var j = JSON.stringify(o);
  var housenum = o['house number']; // 123
}

result of o

{
  "house number": "123",
  "street name": "Main",
  "street type": "St"
}

How to overload functions in javascript?

No Problem with Overloading in JS , The pb how to maintain a clean code when overloading function ?

You can use a forward to have clean code, based on two things:

  1. Number of arguments (when calling the function).
  2. Type of arguments (when calling the function)

      function myFunc(){
          return window['myFunc_'+arguments.length+Array.from(arguments).map((arg)=>typeof arg).join('_')](...arguments);
       }
    
        /** one argument & this argument is string */
      function myFunc_1_string(){
    
      }
       //------------
       /** one argument & this argument is object */
      function myFunc_1_object(){
    
      }
      //----------
      /** two arguments & those arguments are both string */
      function myFunc_2_string_string(){
    
      }
       //--------
      /** Three arguments & those arguments are : id(number),name(string), callback(function) */
      function myFunc_3_number_string_function(){
                let args=arguments;
                  new Person(args[0],args[1]).onReady(args[3]);
      }
    
       //--- And so on ....   
    

How to run TestNG from command line

You will need to use semicolon as delimiter while specifying the jar and class file path in windows. This solved the issue.
Assuming the class file is under C:.

java -cp ".;C:\testng.jar" org.testng.TestNG testing.xml

Android button font size

You define these attributes in xml as you would anything else, for example:

<Button android:id="@+id/next_button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/next"
            android:background="@drawable/mybutton_background"
            android:textSize="10sp" /> <!-- Use SP(Scale Independent Pixel) -->

You can find the allowed attributes in the api.

Or, if you want this to apply to all buttons in your application, create a style. See the Styles and Themes development documentation.

Find what 2 numbers add to something and multiply to something

That's basically a set of 2 simultaneous equations:

x*y = a
X+y = b

(using the mathematical convention of x and y for the variables to solve and a and b for arbitrary constants).

But the solution involves a quadratic equation (because of the x*y), so depending on the actual values of a and b, there may not be a solution, or there may be multiple solutions.

using wildcards in LDAP search filters/queries

A filter argument with a trailing * can be evaluated almost instantaneously via an index lookup. A leading * implies a sequential search through the index, so it is O(N). It will take ages.

I suggest you reconsider the requirement.

Java - get the current class name?

Try using this this.getClass().getCanonicalName() or this.getClass().getSimpleName(). If it's an anonymous class, use this.getClass().getSuperclass().getName()

Find package name for Android apps to use Intent to launch Market app from web

Adding to the above answers: To find the package name of installed apps on any android device: Go to Storage/Android/data/< package-name >

Is there any use for unique_ptr with array?

There are tradeoffs, and you pick the solution which matches what you want. Off the top of my head:

Initial size

  • vector and unique_ptr<T[]> allow the size to be specified at run-time
  • array only allows the size to be specified at compile time

Resizing

  • array and unique_ptr<T[]> do not allow resizing
  • vector does

Storage

  • vector and unique_ptr<T[]> store the data outside the object (typically on the heap)
  • array stores the data directly in the object

Copying

  • array and vector allow copying
  • unique_ptr<T[]> does not allow copying

Swap/move

  • vector and unique_ptr<T[]> have O(1) time swap and move operations
  • array has O(n) time swap and move operations, where n is the number of elements in the array

Pointer/reference/iterator invalidation

  • array ensures pointers, references and iterators will never be invalidated while the object is live, even on swap()
  • unique_ptr<T[]> has no iterators; pointers and references are only invalidated by swap() while the object is live. (After swapping, pointers point into to the array that you swapped with, so they're still "valid" in that sense.)
  • vector may invalidate pointers, references and iterators on any reallocation (and provides some guarantees that reallocation can only happen on certain operations).

Compatibility with concepts and algorithms

  • array and vector are both Containers
  • unique_ptr<T[]> is not a Container

I do have to admit, this looks like an opportunity for some refactoring with policy-based design.

Converting time stamps in excel to dates

i got result from this in LibreOffice Calc :

=DATE(1970,1,1)+Column_id_here/60/60/24

Convert a JSON String to a HashMap

Hope this will work, try this:

import com.fasterxml.jackson.databind.ObjectMapper;
Map<String, Object> response = new ObjectMapper().readValue(str, HashMap.class);

str, your JSON String

As Simple as this, if you want emailid,

String emailIds = response.get("email id").toString();

Removing the title text of an iOS UIBarButtonItem

Here's what I'm doing me, which is simpler to remove the title of back button

override func viewDidLoad() {
    super.viewDidLoad()
    navigationController?.navigationBar?.backItem?.title = ""
}

Python: download a file from an FTP server

requests library doesn't support ftp links.

To download a file from FTP server you could:

import urllib 

urllib.urlretrieve('ftp://server/path/to/file', 'file')
# if you need to pass credentials:
#   urllib.urlretrieve('ftp://username:password@server/path/to/file', 'file')

Or:

import shutil
import urllib2
from contextlib import closing

with closing(urllib2.urlopen('ftp://server/path/to/file')) as r:
    with open('file', 'wb') as f:
        shutil.copyfileobj(r, f)

Python3:

import shutil
import urllib.request as request
from contextlib import closing

with closing(request.urlopen('ftp://server/path/to/file')) as r:
    with open('file', 'wb') as f:
        shutil.copyfileobj(r, f)

How to get the second column from command output?

If you have GNU awk this is the solution you want:

$ awk '{print $1}' FPAT='"[^"]+"' file
"A B"
"C"
"D"

(Mac) -bash: __git_ps1: command not found

For git, there are /Applications/Xcode.app/Contents/Developer/usr/share/git-core/git-prompt.sh. And please look /etc/bashrc_Apple_Terminal too.

So, I put these in ~/.bash_profile:

if [ -f /Applications/Xcode.app/Contents/Developer/usr/share/git-core/git-prompt.sh ]; then
  . /Applications/Xcode.app/Contents/Developer/usr/share/git-core/git-prompt.sh
  export GIT_PS1_SHOWCOLORHINTS=1
  export GIT_PS1_SHOWDIRTYSTATE=1
  PROMPT_COMMAND="${PROMPT_COMMAND:+$PROMPT_COMMAND; }__git_ps1 '\u:\w' '\\\$ '"
fi

Editor does not contain a main type in Eclipse

Make sure you do Run As > Java Application.

If not you could try a Project > Clean

Some more questions that deals with this that could be helpful, Refer this

Installing python module within code

i added some exception handling to @Aaron's answer.

import subprocess
import sys

try:
    import pandas as pd
except ImportError:
    subprocess.check_call([sys.executable, "-m", "pip", "install", 'pandas'])
finally:
    import pandas as pd

No internet on Android emulator - why and how to fix?

on OSX, Little Snitch was automatically denying any connection to Eclipse (and the emulator). Allow connections in Little Snitch, you have to go into Little Snitch's rules

jQuery detect if string contains something

use Contains of jquery Contains like this

if ($('.type:contains("> <")').length > 0)
{
 //do stuffs to change 
}

Passing data between controllers in Angular JS?

From the description, seems as though you should be using a service. Check out http://egghead.io/lessons/angularjs-sharing-data-between-controllers and AngularJS Service Passing Data Between Controllers to see some examples.

You could define your product service (as a factory) as such:

app.factory('productService', function() {
  var productList = [];

  var addProduct = function(newObj) {
      productList.push(newObj);
  };

  var getProducts = function(){
      return productList;
  };

  return {
    addProduct: addProduct,
    getProducts: getProducts
  };

});

Dependency inject the service into both controllers.

In your ProductController, define some action that adds the selected object to the array:

app.controller('ProductController', function($scope, productService) {
    $scope.callToAddToProductList = function(currObj){
        productService.addProduct(currObj);
    };
});

In your CartController, get the products from the service:

app.controller('CartController', function($scope, productService) {
    $scope.products = productService.getProducts();
});

Simplest way to do grouped barplot

with ggplot2:

library(ggplot2)
Animals <- read.table(
  header=TRUE, text='Category        Reason Species
1   Decline       Genuine      24
2  Improved       Genuine      16
3  Improved Misclassified      85
4   Decline Misclassified      41
5   Decline     Taxonomic       2
6  Improved     Taxonomic       7
7   Decline       Unclear      41
8  Improved       Unclear     117')

ggplot(Animals, aes(factor(Reason), Species, fill = Category)) + 
  geom_bar(stat="identity", position = "dodge") + 
  scale_fill_brewer(palette = "Set1")

Bar Chart

VBA check if object is set

If obj Is Nothing Then
    ' need to initialize obj: '
    Set obj = ...
Else
    ' obj already set / initialized. '
End If

Or, if you prefer it the other way around:

If Not obj Is Nothing Then
    ' obj already set / initialized. '
Else
    ' need to initialize obj: '
    Set obj = ...
End If

PHP isset() with multiple parameters

Use the php's OR (||) logical operator for php isset() with multiple operator e.g

if (isset($_POST['room']) || ($_POST['cottage']) || ($_POST['villa'])) {

}

How to hide/show div tags using JavaScript?

Use the following code:

function hide {
document.getElementById('div').style.display = "none";
}
function show {
document.getElementById('div').style.display = "block";
}

Regular expression negative lookahead

If you revise your regular expression like this:

drupal-6.14/(?=sites(?!/all|/default)).*
             ^^

...then it will match all inputs that contain drupal-6.14/ followed by sites followed by anything other than /all or /default. For example:

drupal-6.14/sites/foo
drupal-6.14/sites/bar
drupal-6.14/sitesfoo42
drupal-6.14/sitesall

Changing ?= to ?! to match your original regex simply negates those matches:

drupal-6.14/(?!sites(?!/all|/default)).*
             ^^

So, this simply means that drupal-6.14/ now cannot be followed by sites followed by anything other than /all or /default. So now, these inputs will satisfy the regex:

drupal-6.14/sites/all
drupal-6.14/sites/default
drupal-6.14/sites/all42

But, what may not be obvious from some of the other answers (and possibly your question) is that your regex will also permit other inputs where drupal-6.14/ is followed by anything other than sites as well. For example:

drupal-6.14/foo
drupal-6.14/xsites

Conclusion: So, your regex basically says to include all subdirectories of drupal-6.14 except those subdirectories of sites whose name begins with anything other than all or default.

How to ignore certain files in Git

git reset filename
git rm --cached filename

then add your file which you want to ignore it,

then commit and push to your repository

SQL Server converting varbinary to string

If you want to convert a single VARBINARY value into VARCHAR (STRING) you can do by declaring a variable like this:

DECLARE @var VARBINARY(MAX)
SET @var = 0x21232F297A57A5A743894A0E4A801FC3
SELECT CAST(@var AS VARCHAR(MAX))

If you are trying to select from table column then you can do like this:

SELECT CAST(myBinaryCol AS VARCHAR(MAX))
FROM myTable

MAVEN_HOME, MVN_HOME or M2_HOME

MAVEN_HOME is used for maven 1 and M2_HOME is used to locate maven 2. Having the two different _HOME variables means it is possible to run both on the same machine. And if you check old mvn.cmd scripts they have something like,

@REM ----------------------------------------------------------------------------
@REM Maven2 Start Up Batch script
@REM
@REM Required ENV vars:
@REM JAVA_HOME - location of a JDK home dir
@REM
@REM Optional ENV vars
@REM M2_HOME - location of maven2's installed home dir
@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a key stroke before ending
@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
@REM     e.g. to debug Maven itself, use
@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
@REM ----------------------------------------------------------------------------

See that @REM M2_HOME - location of maven2's installed home dir

Anyway usage of this pattern is now deprecated with maven 3.5 as per the documentation.

Based on problems in using M2_HOME related to different Maven versions installed and to simplify things, the usage of M2_HOME has been removed and is not supported any more MNG-5823, MNG-5836, MNG-5607

So now the mvn.cmd look like,

@REM -----------------------------------------------------------------------------
@REM Apache Maven Startup Script
@REM
@REM Environment Variable Prerequisites
@REM
@REM   JAVA_HOME          Must point at your Java Development Kit installation.
@REM   MAVEN_BATCH_ECHO  (Optional) Set to 'on' to enable the echoing of the batch commands.
@REM   MAVEN_BATCH_PAUSE (Optional) set to 'on' to wait for a key stroke before ending.
@REM   MAVEN_OPTS        (Optional) Java runtime options used when Maven is executed.
@REM   MAVEN_SKIP_RC     (Optional) Flag to disable loading of mavenrc files.
@REM -----------------------------------------------------------------------------

So what you need is JAVA_HOME to be set correctly. As per the new installation guide (as of 12/29/2017), Just add the maven bin directory path to the PATH variable. It should do the trick.

ex : export PATH=/opt/apache-maven-3.5.2/bin:$PATH

Live Video Streaming with PHP

For live video conferencing you can't ignore the need of a streaming server.

Yes, flash will let you display video from a webcam within the local flash control, but that won't let you then send that video over the network - for that you need a streaming server to send it to.

If you're going to build something like this it's prudent to think about how you're going to host the video from a very early stage as it will influence how you build the application. Flash/Flex/Silverlight/Windows Media....etc....

How do I get the latest version of my code?

I understand you want to trash your local changes and pull down what's on your remote?

If all else fails, and if you're (quite understandably) scared of "reset", the simplest thing is just to clone origin into a new directory and trash your old one.

Efficient way to Handle ResultSet in Java

A couple of things to enhance the other answers. First, you should never return a HashMap, which is a specific implementation. Return instead a plain old java.util.Map. But that's actually not right for this example, anyway. Your code only returns the last row of the ResultSet as a (Hash)Map. You instead want to return a List<Map<String,Object>>. Think about how you should modify your code to do that. (Or you could take Dave Newton's suggestion).

How to get all columns' names for all the tables in MySQL?

select * from information_schema.columns
where table_schema = 'your_db'
order by table_name,ordinal_position

Soft Edges using CSS?

It depends on what type of fading you are looking for.

But with shadow and rounded corners you can get a nice result. Rounded corners because the bigger the shadow, the weirder it will look in the edges unless you balance it out with rounded corners.

http://jsfiddle.net/tLu7u/

also.. http://css3pie.com/

Browse for a directory in C#

string folderPath = "";
FolderBrowserDialog folderBrowserDialog1 = new FolderBrowserDialog();
if (folderBrowserDialog1.ShowDialog() == DialogResult.OK) {
    folderPath = folderBrowserDialog1.SelectedPath ;
}

Optimal way to concatenate/aggregate strings

Although @serge answer is correct but i compared time consumption of his way against xmlpath and i found the xmlpath is so faster. I'll write the compare code and you can check it by yourself. This is @serge way:

DECLARE @startTime datetime2;
DECLARE @endTime datetime2;
DECLARE @counter INT;
SET @counter = 1;

set nocount on;

declare @YourTable table (ID int, Name nvarchar(50))

WHILE @counter < 1000
BEGIN
    insert into @YourTable VALUES (ROUND(@counter/10,0), CONVERT(NVARCHAR(50), @counter) + 'CC')
    SET @counter = @counter + 1;
END

SET @startTime = GETDATE()

;WITH Partitioned AS
(
    SELECT 
        ID,
        Name,
        ROW_NUMBER() OVER (PARTITION BY ID ORDER BY Name) AS NameNumber,
        COUNT(*) OVER (PARTITION BY ID) AS NameCount
    FROM @YourTable
),
Concatenated AS
(
    SELECT ID, CAST(Name AS nvarchar) AS FullName, Name, NameNumber, NameCount FROM Partitioned WHERE NameNumber = 1

    UNION ALL

    SELECT 
        P.ID, CAST(C.FullName + ', ' + P.Name AS nvarchar), P.Name, P.NameNumber, P.NameCount
    FROM Partitioned AS P
        INNER JOIN Concatenated AS C ON P.ID = C.ID AND P.NameNumber = C.NameNumber + 1
)
SELECT 
    ID,
    FullName
FROM Concatenated
WHERE NameNumber = NameCount

SET @endTime = GETDATE();

SELECT DATEDIFF(millisecond,@startTime, @endTime)
--Take about 54 milliseconds

And this is xmlpath way:

DECLARE @startTime datetime2;
DECLARE @endTime datetime2;
DECLARE @counter INT;
SET @counter = 1;

set nocount on;

declare @YourTable table (RowID int, HeaderValue int, ChildValue varchar(5))

WHILE @counter < 1000
BEGIN
    insert into @YourTable VALUES (@counter, ROUND(@counter/10,0), CONVERT(NVARCHAR(50), @counter) + 'CC')
    SET @counter = @counter + 1;
END

SET @startTime = GETDATE();

set nocount off
SELECT
    t1.HeaderValue
        ,STUFF(
                   (SELECT
                        ', ' + t2.ChildValue
                        FROM @YourTable t2
                        WHERE t1.HeaderValue=t2.HeaderValue
                        ORDER BY t2.ChildValue
                        FOR XML PATH(''), TYPE
                   ).value('.','varchar(max)')
                   ,1,2, ''
              ) AS ChildValues
    FROM @YourTable t1
    GROUP BY t1.HeaderValue

SET @endTime = GETDATE();

SELECT DATEDIFF(millisecond,@startTime, @endTime)
--Take about 4 milliseconds

ASP.NET MVC: What is the purpose of @section?

A good example is Javascript. You want this to be at the bottom of the page that is rendered in the browser because this is best practice.

How would you do this from a View based on a Layout/Masterpage where you can only access the middle of the page?

You do this by declaring a Scripts section at the bottom of the Layout page. Then you can add content, in this case Javascript includes (I hope!), from your View page to the bottom of your layout page.

How can I switch views programmatically in a view controller? (Xcode, iPhone)

If you want to present a new view in the same storyboard,

In CurrentViewController.m,

#import "YourViewController.h"

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
YourViewController *viewController = (YourViewController *)[storyboard instantiateViewControllerWithIdentifier:@"YourViewControllerIdentifier"];
[self presentViewController:viewController animated:YES completion:nil];

To set identifier to a view controller, Open MainStoryBoard.storyboard. Select YourViewController View-> Utilities -> ShowIdentityInspector. There you can specify the identifier.

Concatenating two std::vectors

std::vector<int> first;
std::vector<int> second;

first.insert(first.end(), second.begin(), second.end());

Run C++ in command prompt - Windows

have MinGW compiler bin directory added to path.

use mingw32-g++ -s -c source_file_name.cpp -o output_file_name.o to compile

then mingw32-g++ -o executable_file_name.exe output_file_name.o to build exe

finally, you run with executable_file_name.exe

Cannot find or open the PDB file in Visual Studio C++ 2010

Working with VS 2013.
Try the following Tools -> Options -> Debugging -> Output Window -> Module Load Messages -> Off

It will disable the display of modules loaded.

Convert Object to JSON string

Convert JavaScript object to json data

$("form").submit(function(event){
  event.preventDefault();
  var formData = $("form").serializeArray(); // Create array of object
  var jsonConvertedData = JSON.stringify(formData);  // Convert to json
  consol.log(jsonConvertedData);
});

You can validate json data using http://jsonlint.com

Does Hibernate create tables in the database automatically

yes you can use

<property name="hbm2ddl.auto" value="create"/>

How can I determine installed SQL Server instances and their versions?

I had this same issue when I was assessing 100+ servers, I had a script written in C# to browse the service names consist of SQL. When instances installed on the server, SQL Server adds a service for each instance with service name. It may vary for different versions like 2000 to 2008 but for sure there is a service with instance name.

I take the service name and obtain instance name from the service name. Here is the sample code used with WMI Query Result:

if (ServiceData.DisplayName == "MSSQLSERVER" || ServiceData.DisplayName == "SQL Server (MSSQLSERVER)")
            {
                InstanceData.Name = "DEFAULT";
                InstanceData.ConnectionName = CurrentMachine.Name;
                CurrentMachine.ListOfInstances.Add(InstanceData);
            }
            else
                if (ServiceData.DisplayName.Contains("SQL Server (") == true)
                {
                    InstanceData.Name = ServiceData.DisplayName.Substring(
                                            ServiceData.DisplayName.IndexOf("(") + 1,
                                            ServiceData.DisplayName.IndexOf(")") - ServiceData.DisplayName.IndexOf("(") - 1
                                        );
                    InstanceData.ConnectionName = CurrentMachine.Name + "\\" + InstanceData.Name;
                    CurrentMachine.ListOfInstances.Add(InstanceData);
                }
                else
                    if (ServiceData.DisplayName.Contains("MSSQL$") == true)
                    {
                        InstanceData.Name = ServiceData.DisplayName.Substring(
                                                ServiceData.DisplayName.IndexOf("$") + 1,
                                                ServiceData.DisplayName.Length - ServiceData.DisplayName.IndexOf("$") - 1
                                            );

                        InstanceData.ConnectionName = CurrentMachine.Name + "\\" + InstanceData.Name;
                        CurrentMachine.ListOfInstances.Add(InstanceData);
                    }

Is there a code obfuscator for PHP?

People will offer you obfuscators, but no amount of obfuscation can prevent someone from getting at your code. None. If your computer can run it, or in the case of movies and music if it can play it, the user can get at it. Even compiling it to machine code just makes the job a little more difficult. If you use an obfuscator, you are just fooling yourself. Worse, you're also disallowing your users from fixing bugs or making modifications.

Music and movie companies haven't quite come to terms with this yet, they still spend millions on DRM.

In interpreted languages like PHP and Perl it's trivial. Perl used to have lots of code obfuscators, then we realized you can trivially decompile them.

perl -MO=Deparse some_program

PHP has things like DeZender and Show My Code.

My advice? Write a license and get a lawyer. The only other option is to not give out the code and instead run a hosted service.

See also the perlfaq entry on the subject.

Efficient SQL test query or validation query that will work across all (or most) databases

select 1 would work in sql server, not sure about the others.

Use standard ansi sql to create a table and then query from that table.

Where to put a textfile I want to use in eclipse?

Just create a folder Files under src and put your file there. This will look like src/Files/myFile.txt

Note: In your code you need to specify like this Files/myFile.txt e.g.

getResource("Files/myFile.txt");

So when you build your project and run the .jar file this should be able to work.

How to automatically close cmd window after batch file execution?

To close the current cmd windows immediately, just add as the last command/line:

move nul 2>&0

Try move nul to nowhere and redirect the stderr to stdin will result in the current window cmd.exe being closed

This is different from closing a bat, or exiting it using goto :EOF or Exit /b

Bootstrap 3 - Set Container Width to 940px Maximum for Desktops?

In the first place consider the Small grid, see: http://getbootstrap.com/css/#grid-options. A max container width of 750 px will maybe to small for you (also read: Why does Bootstrap 3 force the container width to certain sizes?)

When using the Small grid use media queries to set the max-container width:

@media (min-width: 768px) { .container { max-width: 750px; } }

Second also read this question: Bootstrap 3 - 940px width grid?, possible duplicate?

12 x 60 = 720px for the columns and 11 x 20 = 220px

there will also a gutter of 20px on both sides of the grid so 220 + 720 + 40 makes 980px

there is 'no' @ColumnWidth

You colums width will be calculated dynamically based on your settings in variables.less. you could set @grid-columns and @grid-gutter-width. The width of a column will be set as a percentage via grid.less in mixins.less:

.calc-grid(@index, @class, @type) when (@type = width) {
  .col-@{class}-@{index} {
    width: percentage((@index / @grid-columns));
  }
}

update Set @grid-gutter-width to 20px;, @container-desktop: 940px;, @container-large-desktop: @container-desktop and recompile bootstrap.

How do you use NSAttributedString?

Super easy way to do this.

let text = "This is a colorful attributed string"
let attributedText = 
NSMutableAttributedString.getAttributedString(fromString: text)
attributedText.apply(color: .red, subString: "This")
//Apply yellow color on range
attributedText.apply(color: .yellow, onRange: NSMakeRange(5, 4))

For more detail click here; https://github.com/iOSTechHub/AttributedString

Multiple submit buttons in the same form calling different Servlets

There are several ways to achieve this.

Probably the easiest would be to use JavaScript to change the form's action.

<input type="submit" value="SecondServlet" onclick="form.action='SecondServlet';">

But this of course won't work when the enduser has JS disabled (mobile browsers, screenreaders, etc).


Another way is to put the second button in a different form, which may or may not be what you need, depending on the concrete functional requirement, which is not clear from the question at all.

<form action="FirstServlet" method="Post">
    Last Name: <input type="text" name="lastName" size="20">
    <br><br>
    <input type="submit" value="FirstServlet">
</form>
<form action="SecondServlet" method="Post">
    <input type="submit"value="SecondServlet">
</form>

Note that a form would on submit only send the input data contained in the very same form, not in the other form.


Again another way is to just create another single entry point servlet which delegates further to the right servlets (or preferably, the right business actions) depending on the button pressed (which is by itself available as a request parameter by its name):

<form action="MainServlet" method="Post">
    Last Name: <input type="text" name="lastName" size="20">
    <br><br>
    <input type="submit" name="action" value="FirstServlet">
    <input type="submit" name="action" value="SecondServlet">
</form>

with the following in MainServlet

String action = request.getParameter("action");

if ("FirstServlet".equals(action)) {
    // Invoke FirstServlet's job here.
} else if ("SecondServlet".equals(action)) {
    // Invoke SecondServlet's job here.
}

This is only not very i18n/maintenance friendly. What if you need to show buttons in a different language or change the button values while forgetting to take the servlet code into account?


A slight change is to give the buttons its own fixed and unique name, so that its presence as request parameter could be checked instead of its value which would be sensitive to i18n/maintenance:

<form action="MainServlet" method="Post">
    Last Name: <input type="text" name="lastName" size="20">
    <br><br>
    <input type="submit" name="first" value="FirstServlet">
    <input type="submit" name="second" value="SecondServlet">
</form>

with the following in MainServlet

if (request.getParameter("first") != null) {
    // Invoke FirstServlet's job here.
} else if (request.getParameter("second") != null) {
    // Invoke SecondServlet's job here.
}

Last way would be to just use a MVC framework like JSF so that you can directly bind javabean methods to buttons, but that would require drastic changes to your existing code.

<h:form>
    Last Name: <h:inputText value="#{bean.lastName}" size="20" />
    <br/><br/>
    <h:commandButton value="First" action="#{bean.first}" />
    <h:commandButton value="Second" action="#{bean.Second}" />
</h:form>

with just the following javabean instead of a servlet

@ManagedBean
@RequestScoped
public class Bean {

    private String lastName; // +getter+setter

    public void first() {
        // Invoke original FirstServlet's job here.
    }

    public void second() {
        // Invoke original SecondServlet's job here.
    }

}

How do I convert uint to int in C#?

Given:

 uint n = 3;

int i = checked((int)n); //throws OverflowException if n > Int32.MaxValue
int i = unchecked((int)n); //converts the bits only 
                           //i will be negative if n > Int32.MaxValue

int i = (int)n; //same behavior as unchecked

or

int i = Convert.ToInt32(n); //same behavior as checked

--EDIT

Included info as mentioned by Kenan E. K.

SQL Server Installation - What is the Installation Media Folder?

For the SQL Server 2019 (Express Edition) installation, I did the following:

  1. Open SQL Server Installation Center
  2. Click on Installation
  3. Click on New SQL Server stand-alone installation or add features to an existing installation
  4. Browse to C:\SQL2019\Express_ENU and click OK

Convert char* to string C++

There seems to be a few details left out of your explanation, but I will do my best...

If these are NUL-terminated strings or the memory is pre-zeroed, you can just iterate down the length of the memory segment until you hit a NUL (0) character or the maximum length (whichever comes first). Use the string constructor, passing the buffer and the size determined in the previous step.

string retrieveString( char* buf, int max ) {

    size_t len = 0;
    while( (len < max) && (buf[ len ] != '\0') ) {
        len++;
    }

    return string( buf, len );

}

If the above is not the case, I'm not sure how you determine where a string ends.

How to enable cross-origin resource sharing (CORS) in the express.js framework on node.js

You must set Access-Control-Allow-Credentials: true, if you want to use "cookie" via "Credentials"

app.all('*', function(req, res, next) {
  res.header('Access-Control-Allow-Origin', '*');
  res.header('Access-Control-Allow-Credentials', true);
  res.header('Access-Control-Allow-Methods', 'PUT, GET, POST, DELETE, OPTIONS');
  res.header('Access-Control-Allow-Headers', 'Content-Type');
  next();
});

Classes cannot be accessed from outside package

Maybe you should try removing "new" keyword and see if works. Because last time I got this error when I tried creating Typeface something like this:

Typeface typeface = new Typeface().create("Arial",Typeface.BOLD);

What's the best way to dedupe a table?

For SQL, you may use the INSERT IGNORE INTO table SELECT xy FROM unkeyed_table;

For an algorithm, if you can assume that to-be-primary keys may be repeated, but a to-be-primary-key uniquely identifies the content of the row, than hash only the to-be-primary key and check for repetition.

How do I set adaptive multiline UILabel text?

I kind of got things working by adding auto layout constraints:

auto layout contraints

But I am not happy with this. Took a lot of trial and error and couldn't understand why this worked.

Also I had to add to use titleLabel.numberOfLines = 0 in my ViewController

Hashing a dictionary?

You can use the maps library to do this. Specifically, maps.FrozenMap

import maps
fm = maps.FrozenMap(my_dict)
hash(fm)

To install maps, just do:

pip install maps

It handles the nested dict case too:

import maps
fm = maps.FrozenMap.recurse(my_dict)
hash(fm)

Disclaimer: I am the author of the maps library.

How to run JUnit test cases from the command line

Actually you can also make the Junit test a runnable Jar and call the runnable jar as java -jar

Defining array with multiple types in TypeScript

My TS lint was complaining about other solutions, so the solution that was working for me was:

item: Array<Type1 | Type2>

if there's only one type, it's fine to use:

item: Type1[]

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

The only built-in way to "downgrade" a database from one SQL Server version to a lower one is the hard way: Script out the whole database, schema and data, then execute the script on the target server.

This is do-able but tends to be brutal.

Python: How do I make a subclass from a superclass?

There is another way to make subclasses in python dynamically with a function type():

SubClass = type('SubClass', (BaseClass,), {'set_x': set_x})  # Methods can be set, including __init__()

You usually want to use this method when working with metaclasses. When you want to do some lower level automations, that alters way how python creates class. Most likely you will not ever need to do it in this way, but when you do, than you already will know what you are doing.

CSS Margin: 0 is not setting to 0

you should have either (or both):

  1. a paddding != 0 on body
  2. a margin !=0 on #header

try

html, #header {
    margin: 0 !important;
    padding: 0 !important;
}

The margin is the "space" outside the box, the padding is the "space" inside the box (between the border and the content). The !important prevent overriding of property by latter rules.

Simple mediaplayer play mp3 from file path?

String filePath = Environment.getExternalStorageDirectory()+"/yourfolderNAme/yopurfile.mp3";
mediaPlayer = new  MediaPlayer();
mediaPlayer.setDataSource(filePath);
mediaPlayer.prepare();   
mediaPlayer.start()

and this play from raw folder.

int resID = myContext.getResources().getIdentifier(playSoundName,"raw",myContext.getPackageName());

            MediaPlayer mediaPlayer = MediaPlayer.create(myContext,resID);
            mediaPlayer.prepare();
            mediaPlayer.start();

mycontext=application.this. use.

How do I upload a file with metadata using a REST web service?

I don't understand why, over the course of eight years, no one has posted the easy answer. Rather than encode the file as base64, encode the json as a string. Then just decode the json on the server side.

In Javascript:

let formData = new FormData();
formData.append("file", myfile);
formData.append("myjson", JSON.stringify(myJsonObject));

POST it using Content-Type: multipart/form-data

On the server side, retrieve the file normally, and retrieve the json as a string. Convert the string to an object, which is usually one line of code no matter what programming language you use.

(Yes, it works great. Doing it in one of my apps.)

What's a simple way to get a text input popup dialog box on an iPhone

Since IOS 9.0 use UIAlertController:

UIAlertController* alert = [UIAlertController alertControllerWithTitle:@"My Alert"
                                                           message:@"This is an alert."
                                                          preferredStyle:UIAlertControllerStyleAlert];

UIAlertAction* defaultAction = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault
                                                  handler:^(UIAlertAction * action) {
                    //use alert.textFields[0].text
                                                       }];
UIAlertAction* cancelAction = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleDefault
                                                      handler:^(UIAlertAction * action) {
                                                          //cancel action
                                                      }];
[alert addTextFieldWithConfigurationHandler:^(UITextField * _Nonnull textField) {
    // A block for configuring the text field prior to displaying the alert
}];
[alert addAction:defaultAction];
[alert addAction:cancelAction];
[self presentViewController:alert animated:YES completion:nil];

CSS3 Transition not working

Transition is more like an animation.

div.sicon a {
    background:-moz-radial-gradient(left, #ffffff 24%, #cba334 88%);
    transition: background 0.5s linear;
    -moz-transition: background 0.5s linear; /* Firefox 4 */
    -webkit-transition: background 0.5s linear; /* Safari and Chrome */
    -o-transition: background 0.5s linear; /* Opera */
    -ms-transition: background 0.5s linear; /* Explorer 10 */
}

So you need to invoke that animation with an action.

div.sicon a:hover {
    background:-moz-radial-gradient(left, #cba334 24%, #ffffff 88%);
}

Also check for browser support and if you still have some problem with whatever you're trying to do! Check css-overrides in your stylesheet and also check out for behavior: ***.htc css hacks.. there may be something overriding your transition!

You should check this out: http://www.w3schools.com/css/css3_transitions.asp

Create table using Javascript

Here is an example of drawing a table using raphael.js. We can draw tables directly to the canvas of the browser using Raphael.js Raphael.js is a javascript library designed specifically for artists and graphic designers.

<!DOCTYPE html>
<html>

    <head>
    </head>
    <body>
        <div id='panel'></div>
    </body>
    <script src="http://cdnjs.cloudflare.com/ajax/libs/raphael/2.1.0/raphael-min.js"> </script>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>

<script>    
paper = new Raphael(0,0,500,500);// width:500px, height:500px

var x = 100;
var y = 50;
var height = 50
var width = 100;

WriteTableRow(x,y,width*2,height,paper,"TOP Title");// draw a table header as merged cell
y= y+height;
WriteTableRow(x,y,width,height,paper,"Score,Player");// draw table header as individual cells
y= y+height;
for (i=1;i<=4;i++)
{
var k;
k = Math.floor(Math.random() * (10 + 1 - 5) + 5);//prepare table contents as random data
WriteTableRow(x,y,width,height,paper,i+","+ k + "");// draw a row
y= y+height;
}


function WriteTableRow(x,y,width,height,paper,TDdata)
{ // width:cell width, height:cell height, paper: canvas, TDdata: texts for a row. Separated each cell content with a comma.

    var TD = TDdata.split(",");
    for (j=0;j<TD.length;j++)
    {
        var rect = paper.rect(x,y,width,height).attr({"fill":"white","stroke":"red"});// draw outline
        paper.text(x+width/2, y+height/2, TD[j]) ;// draw cell text
        x = x + width;
    }
}

</script>

</html>

Please check the preview image: https://i.stack.imgur.com/RAFhH.png

Getting value of HTML Checkbox from onclick/onchange events

Use this

<input type="checkbox" onclick="onClickHandler()" id="box" />

<script>
function onClickHandler(){
    var chk=document.getElementById("box").value;

    //use this value

}
</script>

What are advantages of Artificial Neural Networks over Support Vector Machines?

One answer I'm missing here: Multi-layer perceptron is able to find relation between features. For example it is necessary in computer vision when a raw image is provided to the learning algorithm and now Sophisticated features are calculated. Essentially the intermediate levels can calculate new unknown features.

Select rows having 2 columns equal value

select t.* from table t
    join (
        select C2, C3, C4
        from table
        group by C2, C3, C4
        having count(*) > 1
    ) t2
    using (C2, C3, C4);

How to get the exact local time of client?

Here is a version that works well in September 2020 using fetch and https://worldtimeapi.org/api

_x000D_
_x000D_
fetch("https://worldtimeapi.org/api/ip")
  .then(response => response.json())
  .then(data => console.log(data.dst,data.datetime));
_x000D_
_x000D_
_x000D_

How to redirect 404 errors to a page in ExpressJS?

If you want to redirect to error pages from your functions (routes) then do following things -

  1. Add general error messages code in your app.js -

    app.use(function(err, req, res, next) {
        // set locals, only providing error in development
        res.locals.message = err.message
        res.locals.error = req.app.get('env') === 'development' ? err : {}
    
        // render the error page
        // you can also serve different error pages
        // for example sake, I am just responding with simple error messages 
        res.status(err.status || 500)
       if(err.status === 403){
           return res.send('Action forbidden!');
       }
    
       if(err.status === 404){
           return res.send('Page not found!');
       }
    
       // when status is 500, error handler
       if(err.status === 500) {
           return res.send('Server error occured!');
       }
       res.render('error')
    })
    
  2. In your function, instead of using a error-page redirect you can use set the error status first and then use next() for the code flow to go through above code -

    if(FOUND){
        ...
    }else{
        // redirecting to general error page
        // any error code can be used (provided you have handled its error response)
        res.status(404)
        // calling next() will make the control to go call the step 1. error code
        // it will return the error response according to the error code given (provided you have handled its error response)
        next()
    }
    

Node.js - How to send data from html to express

Using http.createServer is very low-level and really not useful for creating web applications as-is.

A good framework to use on top of it is Express, and I would seriously suggest using it. You can install it using npm install express.

When you have, you can create a basic application to handle your form:

var express = require('express');
var bodyParser = require('body-parser');
var app     = express();

//Note that in version 4 of express, express.bodyParser() was
//deprecated in favor of a separate 'body-parser' module.
app.use(bodyParser.urlencoded({ extended: true })); 

//app.use(express.bodyParser());

app.post('/myaction', function(req, res) {
  res.send('You sent the name "' + req.body.name + '".');
});

app.listen(8080, function() {
  console.log('Server running at http://127.0.0.1:8080/');
});

You can make your form point to it using:

<form action="http://127.0.0.1:8080/myaction" method="post">

The reason you can't run Node on port 80 is because there's already a process running on that port (which is serving your index.html). You could use Express to also serve static content, like index.html, using the express.static middleware.

Pass array to ajax request in $.ajax()

Just use the JSON.stringify method and pass it through as the "data" parameter for the $.ajax function, like follows:

$.ajax({
    type: "POST",
    url: "index.php",
    dataType: "json",
    data: JSON.stringify({ paramName: info }),
    success: function(msg){
        $('.answer').html(msg);
    }
});

You just need to make sure you include the JSON2.js file in your page...

Using Docker-Compose, how to execute multiple commands

* UPDATE *

I figured the best way to run some commands is to write a custom Dockerfile that does everything I want before the official CMD is ran from the image.

docker-compose.yaml:

version: '3'

# Can be used as an alternative to VBox/Vagrant
services:

  mongo:
    container_name: mongo
    image: mongo
    build:
      context: .
      dockerfile: deploy/local/Dockerfile.mongo
    ports:
      - "27017:27017"
    volumes:
      - ../.data/mongodb:/data/db

Dockerfile.mongo:

FROM mongo:3.2.12

RUN mkdir -p /fixtures

COPY ./fixtures /fixtures

RUN (mongod --fork --syslog && \
     mongoimport --db wcm-local --collection clients --file /fixtures/clients.json && \
     mongoimport --db wcm-local --collection configs --file /fixtures/configs.json && \
     mongoimport --db wcm-local --collection content --file /fixtures/content.json && \
     mongoimport --db wcm-local --collection licenses --file /fixtures/licenses.json && \
     mongoimport --db wcm-local --collection lists --file /fixtures/lists.json && \
     mongoimport --db wcm-local --collection properties --file /fixtures/properties.json && \
     mongoimport --db wcm-local --collection videos --file /fixtures/videos.json)

This is probably the cleanest way to do it.

* OLD WAY *

I created a shell script with my commands. In this case I wanted to start mongod, and run mongoimport but calling mongod blocks you from running the rest.

docker-compose.yaml:

version: '3'

services:
  mongo:
    container_name: mongo
    image: mongo:3.2.12
    ports:
      - "27017:27017"
    volumes:
      - ./fixtures:/fixtures
      - ./deploy:/deploy
      - ../.data/mongodb:/data/db
    command: sh /deploy/local/start_mongod.sh

start_mongod.sh:

mongod --fork --syslog && \
mongoimport --db wcm-local --collection clients --file /fixtures/clients.json && \
mongoimport --db wcm-local --collection configs --file /fixtures/configs.json && \
mongoimport --db wcm-local --collection content --file /fixtures/content.json && \
mongoimport --db wcm-local --collection licenses --file /fixtures/licenses.json && \
mongoimport --db wcm-local --collection lists --file /fixtures/lists.json && \
mongoimport --db wcm-local --collection properties --file /fixtures/properties.json && \
mongoimport --db wcm-local --collection videos --file /fixtures/videos.json && \
pkill -f mongod && \
sleep 2 && \
mongod

So this forks mongo, does monogimport and then kills the forked mongo which is detached, and starts it up again without detaching. Not sure if there is a way to attach to a forked process but this does work.

NOTE: If you strictly want to load some initial db data this is the way to do it:

mongo_import.sh

#!/bin/bash
# Import from fixtures

# Used in build and docker-compose mongo (different dirs)
DIRECTORY=../deploy/local/mongo_fixtures
if [[ -d "/fixtures" ]]; then
    DIRECTORY=/fixtures
fi
echo ${DIRECTORY}

mongoimport --db wcm-local --collection clients --file ${DIRECTORY}/clients.json && \
mongoimport --db wcm-local --collection configs --file ${DIRECTORY}/configs.json && \
mongoimport --db wcm-local --collection content --file ${DIRECTORY}/content.json && \
mongoimport --db wcm-local --collection licenses --file ${DIRECTORY}/licenses.json && \
mongoimport --db wcm-local --collection lists --file ${DIRECTORY}/lists.json && \
mongoimport --db wcm-local --collection properties --file ${DIRECTORY}/properties.json && \
mongoimport --db wcm-local --collection videos --file ${DIRECTORY}/videos.json

mongo_fixtures/*.json files were created via mongoexport command.

docker-compose.yaml

version: '3'

services:
  mongo:
    container_name: mongo
    image: mongo:3.2.12
    ports:
      - "27017:27017"
    volumes:
      - mongo-data:/data/db:cached
      - ./deploy/local/mongo_fixtures:/fixtures
      - ./deploy/local/mongo_import.sh:/docker-entrypoint-initdb.d/mongo_import.sh


volumes:
  mongo-data:
    driver: local

Differences between C++ string == and compare()?

One thing that is not covered here is that it depends if we compare string to c string, c string to string or string to string.

A major difference is that for comparing two strings size equality is checked before doing the compare and that makes the == operator faster than a compare.

here is the compare as i see it on g++ Debian 7

// operator ==
  /**
   *  @brief  Test equivalence of two strings.
   *  @param __lhs  First string.
   *  @param __rhs  Second string.
   *  @return  True if @a __lhs.compare(@a __rhs) == 0.  False otherwise.
   */
  template<typename _CharT, typename _Traits, typename _Alloc>
    inline bool
    operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
           const basic_string<_CharT, _Traits, _Alloc>& __rhs)
    { return __lhs.compare(__rhs) == 0; }

  template<typename _CharT>
    inline
    typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, bool>::__type
    operator==(const basic_string<_CharT>& __lhs,
           const basic_string<_CharT>& __rhs)
    { return (__lhs.size() == __rhs.size()
          && !std::char_traits<_CharT>::compare(__lhs.data(), __rhs.data(),
                            __lhs.size())); }

  /**
   *  @brief  Test equivalence of C string and string.
   *  @param __lhs  C string.
   *  @param __rhs  String.
   *  @return  True if @a __rhs.compare(@a __lhs) == 0.  False otherwise.
   */
  template<typename _CharT, typename _Traits, typename _Alloc>
    inline bool
    operator==(const _CharT* __lhs,
           const basic_string<_CharT, _Traits, _Alloc>& __rhs)
    { return __rhs.compare(__lhs) == 0; }

  /**
   *  @brief  Test equivalence of string and C string.
   *  @param __lhs  String.
   *  @param __rhs  C string.
   *  @return  True if @a __lhs.compare(@a __rhs) == 0.  False otherwise.
   */
  template<typename _CharT, typename _Traits, typename _Alloc>
    inline bool
    operator==(const basic_string<_CharT, _Traits, _Alloc>& __lhs,
           const _CharT* __rhs)
    { return __lhs.compare(__rhs) == 0; }

jQuery autohide element after 5 seconds

jQuery(".success_mgs").show(); setTimeout(function(){ jQuery(".success_mgs").hide();},5000);

How can I set response header on express.js assets

You can also add a middleware to add CORS headers, something like this would work:

/**
 * Adds CORS headers to the response
 *
 * {@link https://en.wikipedia.org/wiki/Cross-origin_resource_sharing}
 * {@link http://expressjs.com/en/4x/api.html#res.set}
 * @param {object} request the Request object
 * @param {object} response the Response object
 * @param {function} next function to continue execution
 * @returns {void}
 * @example
 * <code>
 * const express = require('express');
 * const corsHeaders = require('./middleware/cors-headers');
 *
 * const app = express();
 * app.use(corsHeaders);
 * </code>
 */
module.exports = (request, response, next) => {
    // http://expressjs.com/en/4x/api.html#res.set
    response.set({
        'Access-Control-Allow-Origin': '*',
        'Access-Control-Allow-Methods': 'DELETE,GET,PATCH,POST,PUT',
        'Access-Control-Allow-Headers': 'Content-Type,Authorization'
    });

    // intercept OPTIONS method
    if(request.method === 'OPTIONS') {
        response.send(200);
    } else {
        next();
    }
};

how to check if input field is empty

use .val(), it will return the value of the <input>

$("#spa").val().length > 0

And you had a typo, length not lenght.

Jenkins Host key verification failed

  1. login as jenkins using: "sudo su -s /bin/bash jenkins"
  2. git clone the desired repo which causes the key error
  3. it will ask you to add the key by showing Yes/No (enter yes or y)

that's it!

you can now re-run the jenkins job.

I hope you this will fix your issue.

How to stop C# console applications from closing automatically?

Alternatively, you can delay the closing using the following code:

System.Threading.Thread.Sleep(1000);

Note the Sleep is using milliseconds.

Could not load file or assembly System.Net.Http, Version=4.0.0.0 with ASP.NET (MVC 4) Web API OData Prerelease

If this issue occurs, kindly check web.config in below section

Below section gives the version of particular dll used

after checking this section in web.config, open solution explorer and select reference from the project tree as shown . Solution Explorer->Reference

After expanding reference, find the dll which caused the error. Right click on the dll reference and check for version like shown in the image above.

If both config dll version and referenced dll is different you would get this exception. Make sure both are of same version which would help.

Invalid postback or callback argument. Event validation is enabled using '<pages enableEventValidation="true"/>'

I had an experience with DataGrid. One of it's columns was "Select" button. When I was clicking "Select" button of any row I had received this error message:

"Invalid postback or callback argument. Event validation is enabled using in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation."

I changed several codes, and finally I succeeded. My experience route:

1) I changed page attribute to EnableEventValidation="false". But it didn't work. (not only is this dangerous for security reason, my event handler wasn't called: void Grid_SelectedIndexChanged(object sender, EventArgs e)

2) I implemented ClientScript.RegisterForEventValidation in Render method. But it didn't work.

protected override void Render(HtmlTextWriter writer)
{
    foreach (DataGridItem item in this.Grid.Items)
    {
        Page.ClientScript.RegisterForEventValidation(item.UniqueID);
        foreach (TableCell cell in (item as TableRow).Cells)
        {
            Page.ClientScript.RegisterForEventValidation(cell.UniqueID);
            foreach (System.Web.UI.Control control in cell.Controls)
            {
                if (control is Button)
                    Page.ClientScript.RegisterForEventValidation(control.UniqueID);
            }
        }
    }
}

3) I changed my button type in grid column from PushButton to LinkButton. It worked! ("ButtonType="LinkButton"). I think if you can change your button to other controls like "LinkButton" in other cases, it would work properly.

How can I count the number of children?

You don't need jQuery for this. You can use JavaScript's .childNodes.length.

Just make sure to subtract 1 if you don't want to include the default text node (which is empty by default). Thus, you'd use the following:

var count = elem.childNodes.length - 1;

C++: Where to initialize variables in constructor

In short, always prefer initialization lists when possible. 2 reasons:

  • If you do not mention a variable in a class's initialization list, the constructor will default initialize it before entering the body of the constructor you've written. This means that option 2 will lead to each variable being written to twice, once for the default initialization and once for the assignment in the constructor body.

  • Also, as mentioned by mwigdahl and avada in other answers, const members and reference members can only be initialized in an initialization list.

Also note that variables are always initialized on the order they are declared in the class declaration, not in the order they are listed in an initialization list (with proper warnings enabled a compiler will warn you if a list is written out of order). Similarly, destructors will call member destructors in the opposite order, last to first in the class declaration, after the code in your class's destructor has executed.