Programs & Examples On #Wmf

A Windows metafile (WMF) consists of a collection of records that can store an image. The stored image can be rendered by parsing and processing the metafile structure.

how to save canvas as png image?

try this:

var c=document.getElementById("alpha");
var d=c.toDataURL("image/png");
var w=window.open('about:blank','image from canvas');
w.document.write("<img src='"+d+"' alt='from canvas'/>");

This shows image from canvas on new page, but if you have open popup in new tab setting it shows about:blank in address bar.

EDIT:- though window.open("<img src='"+ c.toDataURL('image/png') +"'/>") does not work in FF or Chrome, following works though rendering is somewhat different from what is shown on canvas, I think transparency is the issue:

window.open(c.toDataURL('image/png'));

what does this mean ? image/png;base64?

They serve the actual image inside CSS so there will be less HTTP requests per page.

Why can templates only be implemented in the header file?

The compiler will generate code for each template instantiation when you use a template during the compilation step. In the compilation and linking process .cpp files are converted to pure object or machine code which in them contains references or undefined symbols because the .h files that are included in your main.cpp have no implementation YET. These are ready to be linked with another object file that defines an implementation for your template and thus you have a full a.out executable.

However since templates need to be processed in the compilation step in order to generate code for each template instantiation that you define, so simply compiling a template separate from it's header file won't work because they always go hand and hand, for the very reason that each template instantiation is a whole new class literally. In a regular class you can separate .h and .cpp because .h is a blueprint of that class and the .cpp is the raw implementation so any implementation files can be compiled and linked regularly, however using templates .h is a blueprint of how the class should look not how the object should look meaning a template .cpp file isn't a raw regular implementation of a class, it's simply a blueprint for a class, so any implementation of a .h template file can't be compiled because you need something concrete to compile, templates are abstract in that sense.

Therefore templates are never separately compiled and are only compiled wherever you have a concrete instantiation in some other source file. However, the concrete instantiation needs to know the implementation of the template file, because simply modifying the typename T using a concrete type in the .h file is not going to do the job because what .cpp is there to link, I can't find it later on because remember templates are abstract and can't be compiled, so I'm forced to give the implementation right now so I know what to compile and link, and now that I have the implementation it gets linked into the enclosing source file. Basically, the moment I instantiate a template I need to create a whole new class, and I can't do that if I don't know how that class should look like when using the type I provide unless I make notice to the compiler of the template implementation, so now the compiler can replace T with my type and create a concrete class that's ready to be compiled and linked.

To sum up, templates are blueprints for how classes should look, classes are blueprints for how an object should look. I can't compile templates separate from their concrete instantiation because the compiler only compiles concrete types, in other words, templates at least in C++, is pure language abstraction. We have to de-abstract templates so to speak, and we do so by giving them a concrete type to deal with so that our template abstraction can transform into a regular class file and in turn, it can be compiled normally. Separating the template .h file and the template .cpp file is meaningless. It is nonsensical because the separation of .cpp and .h only is only where the .cpp can be compiled individually and linked individually, with templates since we can't compile them separately, because templates are an abstraction, therefore we are always forced to put the abstraction always together with the concrete instantiation where the concrete instantiation always has to know about the type being used.

Meaning typename T get's replaced during the compilation step not the linking step so if I try to compile a template without T being replaced as a concrete value type that is completely meaningless to the compiler and as a result object code can't be created because it doesn't know what T is.

It is technically possible to create some sort of functionality that will save the template.cpp file and switch out the types when it finds them in other sources, I think that the standard does have a keyword export that will allow you to put templates in a separate cpp file but not that many compilers actually implement this.

Just a side note, when making specializations for a template class, you can separate the header from the implementation because a specialization by definition means that I am specializing for a concrete type that can be compiled and linked individually.

Selecting multiple items in ListView

I would advice to check the logic of ListActivity according to what is needed could be the best way not to lose much time

link

developer.android

How to check if a scope variable is undefined in AngularJS template?

Using undefined to make a decision is usually a sign of bad design in Javascript. You might consider doing something else.

However, to answer your question: I think the best way of doing so would be adding a helper function.

$scope.isUndefined = function (thing) {
    return (typeof thing === "undefined");
}

and in the template

<div ng-show="isUndefined(foo)"></div>

What LaTeX Editor do you suggest for Linux?

I use TeXMaker. If you're using Ubuntu, it should be in the apt-get repository. To install texmaker, run:

sudo apt-get install texmaker

Grep characters before and after match?

You mean, like this:

grep -o '.\{0,20\}test_pattern.\{0,20\}' file

?

That will print up to twenty characters on either side of test_pattern. The \{0,20\} notation is like *, but specifies zero to twenty repetitions instead of zero or more.The -o says to show only the match itself, rather than the entire line.

Using group by on multiple columns

In simple English from GROUP BY with two parameters what we are doing is looking for similar value pairs and get the count to a 3rd column.

Look at the following example for reference. Here I'm using International football results from 1872 to 2020

+----------+----------------+--------+---+---+--------+---------+-------------------+-----+
|       _c0|             _c1|     _c2|_c3|_c4|     _c5|      _c6|                _c7|  _c8|
+----------+----------------+--------+---+---+--------+---------+-------------------+-----+
|1872-11-30|        Scotland| England|  0|  0|Friendly|  Glasgow|           Scotland|FALSE|
|1873-03-08|         England|Scotland|  4|  2|Friendly|   London|            England|FALSE|
|1874-03-07|        Scotland| England|  2|  1|Friendly|  Glasgow|           Scotland|FALSE|
|1875-03-06|         England|Scotland|  2|  2|Friendly|   London|            England|FALSE|
|1876-03-04|        Scotland| England|  3|  0|Friendly|  Glasgow|           Scotland|FALSE|
|1876-03-25|        Scotland|   Wales|  4|  0|Friendly|  Glasgow|           Scotland|FALSE|
|1877-03-03|         England|Scotland|  1|  3|Friendly|   London|            England|FALSE|
|1877-03-05|           Wales|Scotland|  0|  2|Friendly|  Wrexham|              Wales|FALSE|
|1878-03-02|        Scotland| England|  7|  2|Friendly|  Glasgow|           Scotland|FALSE|
|1878-03-23|        Scotland|   Wales|  9|  0|Friendly|  Glasgow|           Scotland|FALSE|
|1879-01-18|         England|   Wales|  2|  1|Friendly|   London|            England|FALSE|
|1879-04-05|         England|Scotland|  5|  4|Friendly|   London|            England|FALSE|
|1879-04-07|           Wales|Scotland|  0|  3|Friendly|  Wrexham|              Wales|FALSE|
|1880-03-13|        Scotland| England|  5|  4|Friendly|  Glasgow|           Scotland|FALSE|
|1880-03-15|           Wales| England|  2|  3|Friendly|  Wrexham|              Wales|FALSE|
|1880-03-27|        Scotland|   Wales|  5|  1|Friendly|  Glasgow|           Scotland|FALSE|
|1881-02-26|         England|   Wales|  0|  1|Friendly|Blackburn|            England|FALSE|
|1881-03-12|         England|Scotland|  1|  6|Friendly|   London|            England|FALSE|
|1881-03-14|           Wales|Scotland|  1|  5|Friendly|  Wrexham|              Wales|FALSE|
|1882-02-18|Northern Ireland| England|  0| 13|Friendly|  Belfast|Republic of Ireland|FALSE|
+----------+----------------+--------+---+---+--------+---------+-------------------+-----+

And now I'm going to group by similar country(column _c7) and tournament(_c5) value pairs by GROUP BY operation,

SELECT `_c5`,`_c7`,count(*)  FROM res GROUP BY `_c5`,`_c7`

+--------------------+-------------------+--------+
|                 _c5|                _c7|count(1)|
+--------------------+-------------------+--------+
|            Friendly|  Southern Rhodesia|      11|
|            Friendly|            Ecuador|      68|
|African Cup of Na...|           Ethiopia|      41|
|Gold Cup qualific...|Trinidad and Tobago|       9|
|AFC Asian Cup qua...|             Bhutan|       7|
|African Nations C...|              Gabon|       2|
|            Friendly|           China PR|     170|
|FIFA World Cup qu...|             Israel|      59|
|FIFA World Cup qu...|              Japan|      61|
|UEFA Euro qualifi...|            Romania|      62|
|AFC Asian Cup qua...|              Macau|       9|
|            Friendly|        South Sudan|       1|
|CONCACAF Nations ...|           Suriname|       3|
|         Copa Newton|          Argentina|      12|
|            Friendly|        Philippines|      38|
|FIFA World Cup qu...|              Chile|      68|
|African Cup of Na...|         Madagascar|      29|
|FIFA World Cup qu...|       Burkina Faso|      30|
| UEFA Nations League|            Denmark|       4|
|        Atlantic Cup|           Paraguay|       2|
+--------------------+-------------------+--------+

Explanation: The meaning of the first row is there were 11 Friendly tournaments held on Southern Rhodesia in total.

Note: Here it's mandatory to use a counter column in this case.

Default fetch type for one-to-one, many-to-one and one-to-many in Hibernate

To answer your question, Hibernate is an implementation of the JPA standard. Hibernate has its own quirks of operation, but as per the Hibernate docs

By default, Hibernate uses lazy select fetching for collections and lazy proxy fetching for single-valued associations. These defaults make sense for most associations in the majority of applications.

So Hibernate will always load any object using a lazy fetching strategy, no matter what type of relationship you have declared. It will use a lazy proxy (which should be uninitialized but not null) for a single object in a one-to-one or many-to-one relationship, and a null collection that it will hydrate with values when you attempt to access it.

It should be understood that Hibernate will only attempt to fill these objects with values when you attempt to access the object, unless you specify fetchType.EAGER.

Inserting values into a SQL Server database using ado.net via C#

Remove the comma

... Gender,Contact, " + ") VALUES ...
                  ^-----------------here

Counting the number of elements with the values of x in a vector

You can make a function to give you results.

# your list
numbers <- c(4,23,4,23,5,43,54,56,657,67,67,435,
         453,435,324,34,456,56,567,65,34,435)

function1<-function(x){
    if(x==value){return(1)}else{ return(0) }
}

# set your value here
value<-4

# make a vector which return 1 if it equal to your value, 0 else
vector<-sapply(numbers,function(x) function1(x))
sum(vector)

result: 2

Android Studio suddenly cannot resolve symbols

try to change your build.gradle with these value:

android { compileSdkVersion 18 buildToolsVersion '21.0.1'

defaultConfig {
    minSdkVersion 18
    targetSdkVersion 18
}

Check if record exists from controller in Rails

I would do it this way if you needed an instance variable of the object to work with:

if @business = Business.where(:user_id => current_user.id).first
  #Do stuff
else
  #Do stuff
end

Setting public class variables

You're "setting" the value of that variable/attribute. Not overriding or overloading it. Your code is very, very common and normal.

All of these terms ("set", "override", "overload") have specific meanings. Override and Overload are about polymorphism (subclassing).

From http://en.wikipedia.org/wiki/Object-oriented_programming :

Polymorphism allows the programmer to treat derived class members just like their parent class' members. More precisely, Polymorphism in object-oriented programming is the ability of objects belonging to different data types to respond to method calls of methods of the same name, each one according to an appropriate type-specific behavior. One method, or an operator such as +, -, or *, can be abstractly applied in many different situations. If a Dog is commanded to speak(), this may elicit a bark(). However, if a Pig is commanded to speak(), this may elicit an oink(). They both inherit speak() from Animal, but their derived class methods override the methods of the parent class; this is Overriding Polymorphism. Overloading Polymorphism is the use of one method signature, or one operator such as "+", to perform several different functions depending on the implementation. The "+" operator, for example, may be used to perform integer addition, float addition, list concatenation, or string concatenation. Any two subclasses of Number, such as Integer and Double, are expected to add together properly in an OOP language. The language must therefore overload the addition operator, "+", to work this way. This helps improve code readability. How this is implemented varies from language to language, but most OOP languages support at least some level of overloading polymorphism.

How to count duplicate rows in pandas dataframe?

ran into this problem today and wanted to include NaNs so I replace them temporarily with "" (empty string). Please comment if you do not understand something :). This solution assumes that "" is not a relevant value for you. It should also work with numerical data (I have tested it sucessfully but not extensively) since pandas will infer the data type again after replacing "" with np.nan.

import pandas as pd

# create test data
df = pd.DataFrame({'test':['foo','bar',None,None,'foo'],
                  'test2':['bar',None,None,None,'bar'],
                  'test3':[None, 'foo','bar',None,None]})

# fill null values with '' to not lose them during groupby
# groupby all columns and calculate the length of the resulting groups
# rename the series obtained with groupby to "group_count"
# reset the index to get a DataFrame
# replace '' with np.nan (this reverts our first operation)
# sort DataFrame by "group_count" descending
df = (df.fillna('')\
      .groupby(df.columns.tolist()).apply(len)\
      .rename('group_count')\
      .reset_index()\
      .replace('',np.nan)\
      .sort_values(by = ['group_count'], ascending = False))
df
  test test2 test3  group_count
3  foo   bar   NaN            2
0  NaN   NaN   NaN            1
1  NaN   NaN   bar            1
2  bar   NaN   foo            1

How do I set the colour of a label (coloured text) in Java?

For single color foreground color

label.setForeground(Color.RED)

For multiple foreground colors in the same label:

(I would probably put two labels next to each other using a GridLayout or something, but here goes...)

You could use html in your label text as follows:

frame.add(new JLabel("<html>Text color: <font color='red'>red</font></html>"));

which produces:

enter image description here

How to restart adb from root to user mode?

adb kill-server and adb start-server only control the adb daemon on the PC side. You need to restart adbd daemon on the device itself after reverting the service.adb.root property change done by adb root:

~$ adb shell id
uid=2000(shell) gid=2000(shell)

~$ adb root
restarting adbd as root

~$ adb shell id
uid=0(root) gid=0(root)

~$ adb shell 'setprop service.adb.root 0; setprop ctl.restart adbd'

~$ adb shell id
uid=2000(shell) gid=2000(shell)

How do I read a date in Excel format in Python?

Expected situation

# Wrong output from cell_values()
42884.0

# Expected output
2017-5-29

Example: Let cell_values(2,2) from sheet number 0 will be the date targeted

Get the required variables as the following

workbook = xlrd.open_workbook("target.xlsx")

sheet = workbook.sheet_by_index(0)

wrongValue = sheet.cell_value(2,2)

And make use of xldate_as_tuple

y, m, d, h, i, s = xlrd.xldate_as_tuple(wrongValue, workbook.datemode)
print("{0} - {1} - {2}".format(y, m, d))

That's my solution

How to read first N lines of a file?

N = 10
with open("file.txt", "a") as file:  # the a opens it in append mode
    for i in range(N):
        line = next(file).strip()
        print(line)

Server Client send/receive simple text

The following code send and recieve the current date and time from and to the server

//The following code is for the server application:

namespace Server
{
    class Program
    {
        const int PORT_NO = 5000;
        const string SERVER_IP = "127.0.0.1";

        static void Main(string[] args)
        {
            //---listen at the specified IP and port no.---
            IPAddress localAdd = IPAddress.Parse(SERVER_IP);
            TcpListener listener = new TcpListener(localAdd, PORT_NO);
            Console.WriteLine("Listening...");
            listener.Start();

            //---incoming client connected---
            TcpClient client = listener.AcceptTcpClient();

            //---get the incoming data through a network stream---
            NetworkStream nwStream = client.GetStream();
            byte[] buffer = new byte[client.ReceiveBufferSize];

            //---read incoming stream---
            int bytesRead = nwStream.Read(buffer, 0, client.ReceiveBufferSize);

            //---convert the data received into a string---
            string dataReceived = Encoding.ASCII.GetString(buffer, 0, bytesRead);
            Console.WriteLine("Received : " + dataReceived);

            //---write back the text to the client---
            Console.WriteLine("Sending back : " + dataReceived);
            nwStream.Write(buffer, 0, bytesRead);
            client.Close();
            listener.Stop();
            Console.ReadLine();
        }
    }
}

//this is the code for the client

namespace Client
{
    class Program
    {
        const int PORT_NO = 5000;
        const string SERVER_IP = "127.0.0.1";
        static void Main(string[] args)
        {
            //---data to send to the server---
            string textToSend = DateTime.Now.ToString();

            //---create a TCPClient object at the IP and port no.---
            TcpClient client = new TcpClient(SERVER_IP, PORT_NO);
            NetworkStream nwStream = client.GetStream();
            byte[] bytesToSend = ASCIIEncoding.ASCII.GetBytes(textToSend);

            //---send the text---
            Console.WriteLine("Sending : " + textToSend);
            nwStream.Write(bytesToSend, 0, bytesToSend.Length);

            //---read back the text---
            byte[] bytesToRead = new byte[client.ReceiveBufferSize];
            int bytesRead = nwStream.Read(bytesToRead, 0, client.ReceiveBufferSize);
            Console.WriteLine("Received : " + Encoding.ASCII.GetString(bytesToRead, 0, bytesRead));
            Console.ReadLine();
            client.Close();
        }
    }
}

while ($row = mysql_fetch_array($result)) - how many loops are being performed?

I'm assuming mysql_fetch_array() perfroms a loop, so I'm interested in if using a while() in conjunction with it, if it saves a nested loop.

No. mysql_fetch_array just returns the next row of the result and advances the internal pointer. It doesn't loop. (Internally it may or may not use some loop somewhere, but that's irrelevant.)

while ($row = mysql_fetch_array($result)) {
   ...
}

This does the following:

  1. mysql_fetch_array retrieves and returns the next row
  2. the row is assigned to $row
  3. the expression is evaluated and if it evaluates to true, the contents of the loop are executed
  4. the procedure begins anew
$row = mysql_fetch_array($result);
foreach($row as $r) {
    ...
}

This does the following:

  1. mysql_fetch_array retrieves and returns the next row
  2. the row is assigned to $row
  3. foreach loops over the contents of the array and executes the contents of the loop as many times as there are items in the array

In both cases mysql_fetch_array does exactly the same thing. You have only as many loops as you write. Both constructs do not do the same thing though. The second will only act on one row of the result, while the first will loop over all rows.

How to re-sign the ipa file?

The answers posted here all didn't quite work for me. They mainly skipped signing embedded frameworks (or including the entitlements).

Here's what's worked for me (it assumes that one ipa file exists is in the current directory):

PROVISION="/path/to/file.mobileprovision"
CERTIFICATE="Name of certificate: To sign with" # must be in the keychain

unzip -q *.ipa
rm -rf Payload/*.app/_CodeSignature/

# Replace embedded provisioning profile
cp "$PROVISION" Payload/*.app/embedded.mobileprovision

# Extract entitlements from app
codesign -d --entitlements :entitlements.plist Payload/*.app/

# Re-sign embedded frameworks
codesign -f -s "$CERTIFICATE" --entitlements entitlements.plist Payload/*.app/Frameworks/*

# Re-sign the app (with entitlements)
codesign -f -s "$CERTIFICATE" --entitlements entitlements.plist Payload/*.app/

zip -qr resigned.ipa Payload

# Cleanup
rm entitlements.plist
rm -r Payload/

Good examples using java.util.logging

I would suggest that you use Apache's commons logging utility. It is highly scalable and supports separate log files for different loggers. See here.

return, return None, and no return at all?

In terms of functionality these are all the same, the difference between them is in code readability and style (which is important to consider)

How to bind a List<string> to a DataGridView control?

The following should work as long as you're bound to anything that implements IEnumerable<string>. It will bind the column directly to the string itself, rather than to a Property Path of that string object.

<sdk:DataGridTextColumn Binding="{Binding}" />

How can I display the users profile pic using the facebook graph api?

I was having a problem fetching profile photos while using CURL. I thought for a while there was something wrong my implementation of the Facebook API, but I need to add a bit to my CURL called:

curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);

How to make bootstrap 3 fluid layout without horizontal scrollbar

In the latest version of Twitter Bootstrap the layout is fluid by default, hence you don't need extra classes to declare your layout as fluid.

You can further refer to -

http://bassjobsen.weblogs.fm/migrate-your-templates-from-twitter-bootstrap-2-x-to-twitter-bootstrap-3/ http://blog.getbootstrap.com/

React Error: Target Container is not a DOM Element

I had encountered the same error with React version 16. This error comes when the Javascript that tries to render the React component is included before the static parent dom element in the html. Fix is same as the accepted answer, i.e. the JavaScript should get included only after the static parent dom element has been defined in the html.

What are the differences between JSON and JSONP?

JSONP stands for “JSON with Padding” and it is a workaround for loading data from different domains. It loads the script into the head of the DOM and thus you can access the information as if it were loaded on your own domain, thus by-passing the cross domain issue.

jsonCallback(
{
    "sites":
    [
        {
            "siteName": "JQUERY4U",
            "domainName": "http://www.jquery4u.com",
            "description": "#1 jQuery Blog for your Daily News, Plugins, Tuts/Tips &amp; Code Snippets."
        },
        {
            "siteName": "BLOGOOLA",
            "domainName": "http://www.blogoola.com",
            "description": "Expose your blog to millions and increase your audience."
        },
        {
            "siteName": "PHPSCRIPTS4U",
            "domainName": "http://www.phpscripts4u.com",
            "description": "The Blog of Enthusiastic PHP Scripters"
        }
    ]
});

(function($) {
var url = 'http://www.jquery4u.com/scripts/jquery4u-sites.json?callback=?';

$.ajax({
   type: 'GET',
    url: url,
    async: false,
    jsonpCallback: 'jsonCallback',
    contentType: "application/json",
    dataType: 'jsonp',
    success: function(json) {
       console.dir(json.sites);
    },
    error: function(e) {
       console.log(e.message);
    }
});

})(jQuery);

Now we can request the JSON via AJAX using JSONP and the callback function we created around the JSON content. The output should be the JSON as an object which we can then use the data for whatever we want without restrictions.

MongoDB: How to find out if an array field contains an element?

I am trying to explain by putting problem statement and solution to it. I hope it will help

Problem Statement:

Find all the published products, whose name like ABC Product or PQR Product, and price should be less than 15/-

Solution:

Below are the conditions that need to be taken care of

  1. Product price should be less than 15
  2. Product name should be either ABC Product or PQR Product
  3. Product should be in published state.

Below is the statement that applies above criterion to create query and fetch data.

$elements = $collection->find(
             Array(
                [price] => Array( [$lt] => 15 ),
                [$or] => Array(
                            [0]=>Array(
                                    [product_name]=>Array(
                                       [$in]=>Array(
                                            [0] => ABC Product,
                                            [1]=> PQR Product
                                            )
                                        )
                                    )
                                ),
                [state]=>Published
                )
            );

How to run html file on localhost?

As Nora suggests, you can use the python simple server. Navigate to the folder from which you want to serve your html page, then execute python -m SimpleHTTPServer. Now you can use your web-browser and navigate to http://localhost:8000/ where your page is being served. If your page is named index.html then the server automatically loads that for you. If you want to access any other page, you'll need to browse to http://localhost:8000/{your page name}

Simplest way to wait some asynchronous tasks complete, in Javascript?

Expanding upon @freakish answer, async also offers a each method, which seems especially suited for your case:

var async = require('async');

async.each(['aaa','bbb','ccc'], function(name, callback) {
    conn.collection(name).drop( callback );
}, function(err) {
    if( err ) { return console.log(err); }
    console.log('all dropped');
});

IMHO, this makes the code both more efficient and more legible. I've taken the liberty of removing the console.log('dropped') - if you want it, use this instead:

var async = require('async');

async.each(['aaa','bbb','ccc'], function(name, callback) {
    // if you really want the console.log( 'dropped' ),
    // replace the 'callback' here with an anonymous function
    conn.collection(name).drop( function(err) {
        if( err ) { return callback(err); }
        console.log('dropped');
        callback()
    });
}, function(err) {
    if( err ) { return console.log(err); }
    console.log('all dropped');
});

Concat all strings inside a List<string> using LINQ

You can use Aggregate, to concatenate the strings into a single, character separated string but will throw an Invalid Operation Exception if the collection is empty.

You can use Aggregate function with a seed string.

var seed = string.Empty;
var seperator = ",";

var cars = new List<string>() { "Ford", "McLaren Senna", "Aston Martin Vanquish"};

var carAggregate = cars.Aggregate(seed,
                (partialPhrase, word) => $"{partialPhrase}{seperator}{word}").TrimStart(',');

you can use string.Join doesn’t care if you pass it an empty collection.

var seperator = ",";

var cars = new List<string>() { "Ford", "McLaren Senna", "Aston Martin Vanquish"};

var carJoin = string.Join(seperator, cars);

How do I see the commit differences between branches in git?

I'd suggest the following to see the difference "in commits". For symmetric difference, repeat the command with inverted args:

git cherry -v master [your branch, or HEAD as default]

Download TS files from video stream

  • Download VLC Player
  • Media
  • Convert/Save
  • Network (Tab)
  • Enter URL of [playlist].m3u8
  • Follow remaining wizard steps to set the stream destination (File)
  • Set appropriate transcoding profile (MP4 at the time of this answer)
  • Watch video

Installation error: INSTALL_FAILED_OLDER_SDK

Mate, my advice is to change virtual device. Download "Genimotion" application, its easy to use and there are a lot of any devices you need

Print a list of all installed node.js modules

for package in `sudo npm -g ls --depth=0 --parseable`; do
    printf "${package##*/}\n";
done

How make background image on newsletter in outlook?

I had exactly this problem a couple of months ago while working on a WYSIWYG email editor for my company. Outlook only supports background images if they're applied to the <body> tag - any other element and it'll fail.

In the end, the only workaround I found was to use <div> element for text input, then during the content submission process I fired an AJAX request with the <div>'s content to a PHP script which wrote the text onto a blank version of our header image, saved the file and returned its (uniquely generated) name. I then used Javascript to remove the <div> and add an <img> tag using the returned filename in the src attribute.

You can get all the info/methodology from the imagecreatefrompng() page on the PHP Docs site.

Click button copy to clipboard using jQuery

jQuery simple solution.

Should be triggered by user's click.

$("<textarea/>").appendTo("body").val(text).select().each(function () {
            document.execCommand('copy');
        }).remove();

How can I add a hint text to WPF textbox?

I once got into the same situation, I solved it following way. I've only fulfilled the requirements of a hint box, you can make it more interactive by adding effects and other things on other events like on focus etc.

WPF CODE (I've removed styling to make it readable)

<Grid Margin="0,0,0,0"  Background="White">
    <Label Name="adminEmailHint" Foreground="LightGray" Padding="6"  FontSize="14">Admin Email</Label>
    <TextBox Padding="4,7,4,8" Background="Transparent" TextChanged="adminEmail_TextChanged" Height="31" x:Name="adminEmail" Width="180" />
</Grid>
<Grid Margin="10,0,10,0" Background="White" >
    <Label Name="adminPasswordHint" Foreground="LightGray" Padding="6"  FontSize="14">Admin Password</Label>
    <PasswordBox Padding="4,6,4,8" Background="Transparent" PasswordChanged="adminPassword_PasswordChanged" Height="31" x:Name="adminPassword" VerticalContentAlignment="Center" VerticalAlignment="Center" Width="180" FontFamily="Helvetica" FontWeight="Light" FontSize="14" Controls:TextBoxHelper.Watermark="Admin Password"  FontStyle="Normal" />
</Grid>

C# Code

private void adminEmail_TextChanged(object sender, TextChangedEventArgs e)
    {
        if(adminEmail.Text.Length == 0)
        {
            adminEmailHint.Visibility = Visibility.Visible;
        }
        else
        {
            adminEmailHint.Visibility = Visibility.Hidden;
        }
    }

private void adminPassword_PasswordChanged(object sender, RoutedEventArgs e)
    {
        if (adminPassword.Password.Length == 0)
        {
            adminPasswordHint.Visibility = Visibility.Visible;
        }
        else
        {
            adminPasswordHint.Visibility = Visibility.Hidden;
        }
    }

How to get the current location in Google Maps Android API v2?

try this

if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
                == PackageManager.PERMISSION_GRANTED) {
    mMap.setMyLocationEnabled(true);
} else {
    // Show rationale and request permission.
}

Delete directory with files in it?

What about this:

function recursiveDelete($dirPath, $deleteParent = true){
    foreach(new RecursiveIteratorIterator(new RecursiveDirectoryIterator($dirPath, FilesystemIterator::SKIP_DOTS), RecursiveIteratorIterator::CHILD_FIRST) as $path) {
        $path->isFile() ? unlink($path->getPathname()) : rmdir($path->getPathname());
    }
    if($deleteParent) rmdir($dirPath);
}

Submit form and stay on same page?

The HTTP/CGI way to do this would be for your program to return an HTTP status code of 204 (No Content).

Java - Check Not Null/Empty else assign default value

Use org.apache.commons.lang3.StringUtils

String emptyString = new String();    
result = StringUtils.defaultIfEmpty(emptyString, "default");
System.out.println(result);

String nullString = null;
result = StringUtils.defaultIfEmpty(nullString, "default");
System.out.println(result);

Both of the above options will print:

default

default

Java getHours(), getMinutes() and getSeconds()

For a time difference, note that the calendar starts at 01.01.1970, 01:00, not at 00:00. If you're using java.util.Date and java.text.SimpleDateFormat, you will have to compensate for 1 hour:

long start = System.currentTimeMillis();
long end = start + (1*3600 + 23*60 + 45) * 1000 + 678; // 1 h 23 min 45.678 s
Date timeDiff = new Date(end - start - 3600000); // compensate for 1h in millis
SimpleDateFormat timeFormat = new SimpleDateFormat("H:mm:ss.SSS");
System.out.println("Duration: " + timeFormat.format(timeDiff));

This will print:

Duration: 1:23:45.678

"Logging out" of phpMyAdmin?

This happens because the current account you have used to log in probably has very limited priviledges.

To fix this problem, you can change your the AllowNoPassword config setting to false in config.inc.php. You may also force the authentication to use the config file and specify the default username and password .

$cfg['Servers'][$i]['AllowNoPassword'] = false;
$cfg['Servers'][$i]['auth_type'] = 'config';

$cfg['Servers'][$i]['user'] = 'root';
$cfg['Servers'][$i]['password'] = ''; // leave blank if no password

After this, the PhPMyAdmin login page should show up when you refresh the page. You can then log in with the default root password.

More details can be found on this post ..

Numpy matrix to array

You can try the following variant:

result=np.array(M).flatten()

Get exception description and stack trace which caused an exception, all as a string

For Python 3.5+:

So, you can get the stacktrace from your exception as from any other exception. Use traceback.TracebackException for it (just replace ex with your exception):

print("".join(traceback.TracebackException.from_exception(ex).format())

An extended example and other features to do this:

import traceback

try:
    1/0
except Exception as ex:
    print("".join(traceback.TracebackException.from_exception(ex).format()) == traceback.format_exc() == "".join(traceback.format_exception(type(ex), ex, ex.__traceback__))) # This is True !!
    print("".join(traceback.TracebackException.from_exception(ex).format()))

The output will be something like this:

True
Traceback (most recent call last):
  File "untidsfsdfsdftled.py", line 29, in <module>
    1/0
ZeroDivisionError: division by zero

AngularJS open modal on button click

Hope this will help you .

Here is Html code:-

    <body>
    <div ng-controller="MyController" class="container">
      <h1>Modal example</h1>
      <button ng-click="open()" class="btn btn-primary">Test Modal</button>

      <modal title="Login form" visible="showModal">
        <form role="form">

        </form>
      </modal>
    </div>
</body>

AngularJs code:-

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

mymodal.controller('MyController', function ($scope) {
    $scope.showModal = false;
    $scope.open = function(){
    $scope.showModal = !$scope.showModal;
    };
  });

mymodal.directive('modal', function () {
    return {
      template: '<div class="modal fade">' + 
          '<div class="modal-dialog">' + 
            '<div class="modal-content">' + 
              '<div class="modal-header">' + 
                '<button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>' + 
                '<h4 class="modal-title">{{ title }}</h4>' + 
              '</div>' + 
              '<div class="modal-body" ng-transclude></div>' + 
            '</div>' + 
          '</div>' + 
        '</div>',
      restrict: 'E',
      transclude: true,
      replace:true,
      scope:true,
      link: function postLink(scope, element, attrs) {
        scope.title = attrs.title;

        scope.$watch(attrs.visible, function(value){
          if(value == true)
            $(element).modal('show');
          else
            $(element).modal('hide');
        });

        $(element).on('shown.bs.modal', function(){
          scope.$apply(function(){
            scope.$parent[attrs.visible] = true;
          });
        });

        $(element).on('hidden.bs.modal', function(){
          scope.$apply(function(){
            scope.$parent[attrs.visible] = false;
          });
        });
      }
    };
  });

Check this--jsfiddle

How to select count with Laravel's fluent query builder?

You can use an array in the select() to define more columns and you can use the DB::raw() there with aliasing it to followers. Should look like this:

$query = DB::table('category_issue')
    ->select(array('issues.*', DB::raw('COUNT(issue_subscriptions.issue_id) as followers')))
    ->where('category_id', '=', 1)
    ->join('issues', 'category_issue.issue_id', '=', 'issues.id')
    ->left_join('issue_subscriptions', 'issues.id', '=', 'issue_subscriptions.issue_id')
    ->group_by('issues.id')
    ->order_by('followers', 'desc')
    ->get();

How can I split a string with a string delimiter?

string[] tokens = str.Split(new[] { "is Marco and" }, StringSplitOptions.None);

If you have a single character delimiter (like for instance ,), you can reduce that to (note the single quotes):

string[] tokens = str.Split(',');

The intel x86 emulator accelerator (HAXM installer) revision 6.0.5 is showing not compatible with windows

Try the following

  1. download HAXM from Intel https://software.intel.com/en-us/android/articles/intel-hardware-accelerated-execution-manager.

  2. Unzip the file and Run intelhaxm-android.exe.

  3. Run silent_install.bat.

In my computer Win10 x64 - VS2015 it worked

VBA Excel Provide current Date in Text box

Actually, it is less complicated than it seems.

Sub 
  today_1()
  ActiveCell.FormulaR1C1 = "=TODAY()"
  ActiveCell.Value = Date
End Sub

Laravel 5.4 Specific Table Migration

First you should create one migration file for your table like:

public function up()
    {
        Schema::create('test', function (Blueprint $table) {
            $table->increments('id');
            $table->string('fname',255);
            $table->string('lname',255);
            $table->rememberToken();
            $table->timestamps();
        });
    }

After create test folder in migrations folder then newly created migration moved/copied in test folder and run below command in your terminal/cmd like:

php artisan migrate --path=/database/migrations/test/

How to fix Error: laravel.log could not be opened?

If problem persists after setting permissions right for the storage and bootstrap/cache folders, first confirm by turning off selinux with the command

setenforce 0 If this works after the above command, this should allow writing, but you've turned off added security server-wide. That's bad. Turn SELinux back.

setenforce 1 Then finally use SELinux to allow writing of the file by using this command

chcon -R -t httpd_sys_rw_content_t storage And you're good to go!

This link helped a lot!

Change background color of iframe issue

JavaScript is what you need. If you are loading iframe when loading the page, insert the test for iframe using the onload event. If iframe is inserted in realtime, then create a callback function on insertion and hook in whatever action you need to take :)

How to remove time portion of date in C# in DateTime object only?

Use date.ToShortDateString() to get the date without the time component

var date = DateTime.Now
var shortDate = date.ToShortDateString() //will give you 16/01/2019

use date.ToString() to customize the format of the date

var date = DateTime.Now
var shortDate = date.ToString('dd-MMM-yyyy') //will give you 16-Jan-2019

ALTER TABLE on dependent column

I believe that you will have to drop the foreign key constraints first. Then update all of the appropriate tables and remap them as they were.

ALTER TABLE [dbo.Details_tbl] DROP CONSTRAINT [FK_Details_tbl_User_tbl];
-- Perform more appropriate alters
ALTER TABLE [dbo.Details_tbl] ADD FOREIGN KEY (FK_Details_tbl_User_tbl) 
    REFERENCES User_tbl(appId);
-- Perform all appropriate alters to bring the key constraints back

However, unless memory is a really big issue, I would keep the identity as an INT. Unless you are 100% positive that your keys will never grow past the TINYINT restraints. Just a word of caution :)

shift a std_logic_vector of n bit to right or left

Use the ieee.numeric_std library, and the appropriate vector type for the numbers you are working on (unsigned or signed).

Then the operators are sla/sra for arithmetic shifts (ie fill with sign bit on right shifts and lsb on left shifts) and sll/srl for logical shifts (ie fill with '0's).

You pass a parameter to the operator to define the number of bits to shift:

A <= B srl 2; -- logical shift right 2 bits

Update:

I have no idea what I was writing above (thanks to Val for pointing that out!)

Of course the correct way to shift signed and unsigned types is with the shift_left and shift_right functions defined in ieee.numeric_std.

The shift and rotate operators sll, ror etc are for vectors of boolean, bit or std_ulogic, and can have interestingly unexpected behaviour in that the arithmetic shifts duplicate the end-bit even when shifting left.

And much more history can be found here:

http://jdebp.eu./FGA/bit-shifts-in-vhdl.html

However, the answer to the original question is still

sig <= tmp sll number_of_bits;

Get/pick an image from Android's built-in Gallery app programmatically

Below solution work for 2.3(Gingerbread)-4.4(Kitkat), 5.0(Lollipop) and 6.0(Marshmallow) also:-

Step 1 Code for opening the gallery to select pics:

public static final int PICK_IMAGE = 1;
private void takePictureFromGalleryOrAnyOtherFolder() 
{
    Intent intent = new Intent();
    intent.setType("image/*");
    intent.setAction(Intent.ACTION_GET_CONTENT);
    startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE);
}

Step 2 Code for getting data in onActivityResult:

 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
            super.onActivityResult(requestCode, resultCode, data);
            if (resultCode == Activity.RESULT_OK) {
               if (requestCode == PICK_IMAGE) {
                    Uri selectedImageUri = data.getData();
                    String imagePath = getRealPathFromURI(selectedImageUri);
                   //Now you have imagePath do whatever you want to do now
                 }//end of inner if
             }//end of outer if
      }

 public String getRealPathFromURI(Uri contentUri) {
        //Uri contentUri = Uri.parse(contentURI);

        String[] projection = { MediaStore.Images.Media.DATA };
        Cursor cursor = null;
        try {
            if (Build.VERSION.SDK_INT > 19) {
                // Will return "image:x*"
                String wholeID = DocumentsContract.getDocumentId(contentUri);
                // Split at colon, use second item in the array
                String id = wholeID.split(":")[1];
                // where id is equal to
                String sel = MediaStore.Images.Media._ID + "=?";

                cursor = context.getContentResolver().query(
                        MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
                        projection, sel, new String[] { id }, null);
            } else {
                cursor = context.getContentResolver().query(contentUri,
                        projection, null, null, null);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        String path = null;
        try {
            int column_index = cursor
                    .getColumnIndex(MediaStore.Images.Media.DATA);
            cursor.moveToFirst();
            path = cursor.getString(column_index).toString();
            cursor.close();
        } catch (NullPointerException e) {
            e.printStackTrace();
        }
        return path;
    }

Error pushing to GitHub - insufficient permission for adding an object to repository database

If you still get this error later after setting the permissions you may need to modify your creation mask. We found our new commits (folders under objects) were still being created with no group write permission, hence only the person who committed them could push into the repository.

We fixed this by setting the umask of the SSH users to 002 with an appropriate group shared by all users.

e.g.

umask 002

where the middle 0 is allowing group write by default.

Linux command: How to 'find' only text files?

Although it is an old question, I think this info bellow will add to the quality of the answers here.

When ignoring files with the executable bit set, I just use this command:

find . ! -perm -111

To keep it from recursively enter into other directories:

find . -maxdepth 1 ! -perm -111

No need for pipes to mix lots of commands, just the powerful plain find command.

  • Disclaimer: it is not exactly what OP asked, because it doesn't check if the file is binary or not. It will, for example, filter out bash script files, that are text themselves but have the executable bit set.

That said, I hope this is useful to anyone.

CSS background image to fit width, height should auto-scale in proportion

Based on tips from https://developer.mozilla.org/en-US/docs/CSS/background-size I end up with the following recipe that worked for me

body {
        overflow-y: hidden ! important;
        overflow-x: hidden ! important;
        background-color: #f8f8f8;
        background-image: url('index.png');
        /*background-size: cover;*/
        background-size: contain;
        background-repeat: no-repeat;
        background-position: right;
}

if else condition in blade file (laravel 5.3)

No curly braces required you can directly write

@if($user->status =='waiting')         
      <td><a href="#" class="viewPopLink btn btn-default1" role="button" data-id="{{ $user->travel_id }}" data-toggle="modal" data-target="#myModal">Approve/Reject<a></td>         
@else
      <td>{{ $user->status }}</td>        
@endif

Insertion sort vs Bubble Sort Algorithms

Another difference, I didn't see here:

Bubble sort has 3 value assignments per swap: you have to build a temporary variable first to save the value you want to push forward(no.1), than you have to write the other swap-variable into the spot you just saved the value of(no.2) and then you have to write your temporary variable in the spot other spot(no.3). You have to do that for each spot - you want to go forward - to sort your variable to the correct spot.

With insertion sort you put your variable to sort in a temporary variable and then put all variables in front of that spot 1 spot backwards, as long as you reach the correct spot for your variable. That makes 1 value assignement per spot. In the end you write your temp-variable into the the spot.

That makes far less value assignements, too.

This isn't the strongest speed-benefit, but i think it can be mentioned.

I hope, I expressed myself understandable, if not, sorry, I'm not a nativ Britain

How to obfuscate Python code effectively?

As other answers have stated, there really just isn't a way that's any good. Base64 can be decoded. Bytecode can be decompiled. Python was initially just interpreted, and most interpreted languages try to speed up machine interpretation more than make it difficult for human interpretation.

Python was made to be readable and shareable, not obfuscated. The language decisions about how code has to be formatted were to promote readability across different authors.

Obfuscating python code just doesn't really mesh with the language. Re-evaluate your reasons for obfuscating the code.

Creating a "logical exclusive or" operator in Java

Here is a var arg XOR method for java...

public static boolean XOR(boolean... args) {
  boolean r = false;
  for (boolean b : args) {
    r = r ^ b;
  }
  return r;
}

Enjoy

How to extract text from a PDF file?

I've got a better work around than OCR and to maintain the page alignment while extracting the text from a PDF. Should be of help:

from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
from pdfminer.converter import TextConverter
from pdfminer.layout import LAParams
from pdfminer.pdfpage import PDFPage
from io import StringIO

def convert_pdf_to_txt(path):
    rsrcmgr = PDFResourceManager()
    retstr = StringIO()
    codec = 'utf-8'
    laparams = LAParams()
    device = TextConverter(rsrcmgr, retstr, codec=codec, laparams=laparams)
    fp = open(path, 'rb')
    interpreter = PDFPageInterpreter(rsrcmgr, device)
    password = ""
    maxpages = 0
    caching = True
    pagenos=set()


    for page in PDFPage.get_pages(fp, pagenos, maxpages=maxpages, password=password,caching=caching, check_extractable=True):
        interpreter.process_page(page)


    text = retstr.getvalue()

    fp.close()
    device.close()
    retstr.close()
    return text

text= convert_pdf_to_txt('test.pdf')
print(text)

Suppress InsecureRequestWarning: Unverified HTTPS request is being made in Python2.6

Why not using pyvmomi original function SmartConnectNoSSL. They added this function on June 14, 2016 and named it ConnectNoSSL, one day after they changed the name to SmartConnectNoSSL, use that instead of by passing the warning with unnecessary lines of code in your project?

Provides a standard method for connecting to a specified server without SSL verification. Useful when connecting to servers with self-signed certificates or when you wish to ignore SSL altogether

service_instance = connect.SmartConnectNoSSL(host=args.ip,
                                             user=args.user,
                                             pwd=args.password)

How can I easily switch between PHP versions on Mac OSX?

i think unlink & link php versions are not enough because we are often using php with apache(httpd), so need to update httpd.conf after switch php version.

i have write shell script for disable/enable php_module automatically inside httpd.conf, look at line 46 to line 54 https://github.com/dangquangthai/switch-php-version-on-mac-sierra/blob/master/switch-php#L46

Follow my steps:

1) Check installed php versions by brew, for sure everything good

> brew list | grep php
#output
php56
php56-intl
php56-mcrypt
php71
php71-intl
php71-mcrypt

2) Run script

> switch-php 71 # or switch-php 56
#output
PHP version [71] found
Switching from [php56] to [php71] ... 
Unlink php56 ... [OK] and Link php71 ... [OK]
Updating Apache2.4 Configuration /usr/local/etc/httpd/httpd.conf ... [OK]
Restarting Apache2.4 ... [OK]
PHP 7.1.11 (cli) (built: Nov  3 2017 08:48:02) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2017 Zend Technologies

3) Finally, when your got above message, check httpd.conf, in my laptop:

vi /usr/local/etc/httpd/httpd.conf

You can see near by LoadModule lines

LoadModule php7_module /usr/local/Cellar/php71/7.1.11_22/libexec/apache2/libphp7.so
#LoadModule php5_module /usr/local/Cellar/php56/5.6.32_8/libexec/apache2/libphp5.so

4) open httpd://localhost/info.php

i hope it helpful

Filtering Pandas DataFrames on dates

If your datetime column have the Pandas datetime type (e.g. datetime64[ns]), for proper filtering you need the pd.Timestamp object, for example:

from datetime import date

import pandas as pd

value_to_check = pd.Timestamp(date.today().year, 1, 1)
filter_mask = df['date_column'] < value_to_check
filtered_df = df[filter_mask]

PHP Adding 15 minutes to Time value

To expand on previous answers, a function to do this could work like this (changing the time and interval formats however you like them according to this for function.date, and this for DateInterval):

(I've also written an alternate form of the below function here.)

// Return adjusted time.

function addMinutesToTime( $time, $plusMinutes ) {

    $time = DateTime::createFromFormat( 'g:i:s', $time );
    $time->add( new DateInterval( 'PT' . ( (integer) $plusMinutes ) . 'M' ) );
    $newTime = $time->format( 'g:i:s' );

    return $newTime;
}

$adjustedTime = addMinutesToTime( '9:15:00', 15 );

echo '<h1>Adjusted Time: ' . $adjustedTime . '</h1>' . PHP_EOL . PHP_EOL;

Formatting Numbers by padding with leading zeros in SQL Server

Another way, just for completeness.

DECLARE @empNumber INT = 7123
SELECT STUFF('000000', 6-LEN(@empNumber)+1, LEN(@empNumber), @empNumber)

Or, as per your query

SELECT STUFF('000000', 6-LEN(EmployeeID)+1, LEN(EmployeeID), EmployeeID) 
         AS EmployeeCode
FROM dbo.RequestItems
WHERE ID=0

Don't understand why UnboundLocalError occurs (closure)

try this

counter = 0

def increment():
  global counter
  counter += 1

increment()

How to make a new List in Java

Let me summarize and add something:

JDK

1. new ArrayList<String>();
2. Arrays.asList("A", "B", "C")

Guava

1. Lists.newArrayList("Mike", "John", "Lesly");
2. Lists.asList("A","B", new String [] {"C", "D"});

Immutable List

1. Collections.unmodifiableList(new ArrayList<String>(Arrays.asList("A","B")));
2. ImmutableList.builder()                                      // Guava
            .add("A")
            .add("B").build();
3. ImmutableList.of("A", "B");                                  // Guava
4. ImmutableList.copyOf(Lists.newArrayList("A", "B", "C"));     // Guava

Empty immutable List

1. Collections.emptyList();
2. Collections.EMPTY_LIST;

List of Characters

1. Lists.charactersOf("String")                                 // Guava
2. Lists.newArrayList(Splitter.fixedLength(1).split("String"))  // Guava

List of Integers

Ints.asList(1,2,3);                                             // Guava

Refresh Page C# ASP.NET

Careful with rewriting URLs, though. I'm using this, so it keeps URLs rewritten.

Response.Redirect(Request.RawUrl);

Error: allowDefinition='MachineToApplication' beyond application level

Delete bin and obj folders. Then rebuild the solution.

How can I open a URL in Android's web browser from my application?

//OnClick Listener

  @Override
      public void onClick(View v) {
        String webUrl = news.getNewsURL();
        if(webUrl!="")
        Utils.intentWebURL(mContext, webUrl);
      }

//Your Util Method

public static void intentWebURL(Context context, String url) {
        if (!url.startsWith("http://") && !url.startsWith("https://")) {
            url = "http://" + url;
        }
        boolean flag = isURL(url);
        if (flag) {
            Intent browserIntent = new Intent(Intent.ACTION_VIEW,
                    Uri.parse(url));
            context.startActivity(browserIntent);
        }

    }

How to use Object.values with typescript?

Instead of

Object.values(myObject);

use

Object["values"](myObject);

In your example case:

const values = Object["values"](data).map(x => x.substr(0, x.length - 4));

This will hide the ts compiler error.

Node.js: how to consume SOAP XML web service

Adding to Kim .J's solution: you can add preserveWhitespace=true in order to avoid a Whitespace error. Like this:

soap.CreateClient(url,preserveWhitespace=true,function(...){

How to set transparent background for Image Button in code?

DON'T USE A TRANSAPENT OR NULL LAYOUT because then the button (or the generic view) will no more highlight at click!!!

I had the same problem and finally I found the correct attribute from Android API to solve the problem. It can apply to any view

Use this in the button specifications

android:background="?android:selectableItemBackground"

This requires API 11

How to drop columns using Rails migration

For older versions of Rails

ruby script/generate migration RemoveFieldNameFromTableName field_name:datatype

For Rails 3 and up

rails generate migration RemoveFieldNameFromTableName field_name:datatype

"Integer number too large" error message for 600851475143

Append suffix L: 23423429L.

By default, java interpret all numeral literals as 32-bit integer values. If you want to explicitely specify that this is something bigger then 32-bit integer you should use suffix L for long values.

Creating threads - Task.Factory.StartNew vs new Thread()

In the first case you are simply starting a new thread while in the second case you are entering in the thread pool.

The thread pool job is to share and recycle threads. It allows to avoid losing a few millisecond every time we need to create a new thread.

There are a several ways to enter the thread pool:

  • with the TPL (Task Parallel Library) like you did
  • by calling ThreadPool.QueueUserWorkItem
  • by calling BeginInvoke on a delegate
  • when you use a BackgroundWorker

time data does not match format

No need to use datetime library. Using the dateutil library there is no need of any format:

>>> from dateutil import parser
>>> s= '25 April, 2020, 2:50, pm, IST'
>>> parser.parse(s)
datetime.datetime(2020, 4, 25, 14, 50)

Re-enabling window.alert in Chrome

I can see that this only for actually turning the dialogs back on. But if you are a web dev and you would like to see a way to possibly have some form of notification when these are off...in the case that you are using native alerts/confirms for validation or whatever. Check this solution to detect and notify the user https://stackoverflow.com/a/23697435/1248536

Generate random colors (RGB)

Taking a uniform random variable as the value of RGB may generate a large amount of gray, white, and black, which are often not the colors we want.

The cv::applyColorMap can easily generate a random RGB palette, and you can choose a favorite color map from the list here

Example for C++11:

#include <algorithm>
#include <numeric>
#include <random>
#include <opencv2/opencv.hpp>

std::random_device rd;
std::default_random_engine re(rd());

// Generating randomized palette
cv::Mat palette(1, 255, CV_8U);
std::iota(palette.data, palette.data + 255, 0);
std::shuffle(palette.data, palette.data + 255, re);
cv::applyColorMap(palette, palette, cv::COLORMAP_JET);

// ...

// Picking random color from palette and drawing
auto randColor = palette.at<cv::Vec3b>(i % palette.cols);
cv::rectangle(img, cv::Rect(0, 0, 100, 100), randColor, -1);

Example for Python3:

import numpy as np, cv2

palette = np.arange(0, 255, dtype=np.uint8).reshape(1, 255, 1)
palette = cv2.applyColorMap(palette, cv2.COLORMAP_JET).squeeze(0)
np.random.shuffle(palette)
# ...

rand_color = tuple(palette[i % palette.shape[0]].tolist())
cv2.rectangle(img, (0, 0), (100, 100), rand_color, -1)

If you don't need so many colors, you can just cut the palette to the desired length.

How do I make an Event in the Usercontrol and have it handled in the Main Form?

For those looking to do this in VB, here's how I got mine to work with a checkbox.

Background: I was trying to make my own checkbox that is a slider/switch control. I've only included the relevant code for this question.

In User control MyCheckbox.ascx

<asp:CheckBox ID="checkbox" runat="server" AutoPostBack="true" />

In User control MyCheckbox.ascx.vb

Create an EventHandler (OnCheckChanged). When an event fires on the control (ID="checkbox") inside your usercontrol (MyCheckBox.ascx), then fire your EventHandler (OnCheckChanged).

Public Event OnCheckChanged As EventHandler

Private Sub checkbox_CheckedChanged(sender As Object, e As EventArgs) Handles checkbox.CheckedChanged
    RaiseEvent OnCheckChanged(Me, e)
End Sub

In Page MyPage.aspx

<uc:MyCheckbox runat="server" ID="myCheck" OnCheckChanged="myCheck_CheckChanged" />

Note: myCheck_CheckChanged didn't fire until I added the Handles clause below

In Page MyPage.aspx.vb

Protected Sub myCheck_CheckChanged (sender As Object, e As EventArgs) Handles scTransparentVoting.OnCheckChanged
    'Do some page logic here
End Sub

R color scatter plot points based on values

Here is a method using a lookup table of thresholds and associated colours to map the colours to the variable of interest.

 # make a grid 'Grd' of points and number points for side of square 'GrdD'
Grd <- expand.grid(seq(0.5,400.5,10),seq(0.5,400.5,10))
GrdD <- length(unique(Grd$Var1))

# Add z-values to the grid points
Grd$z <- rnorm(length(Grd$Var1), mean = 10, sd =2)

# Make a vector of thresholds 'Brks' to colour code z 
Brks <- c(seq(0,18,3),Inf)

# Make a vector of labels 'Lbls' for the colour threhsolds
Lbls <- Lbls <- c('0-3','3-6','6-9','9-12','12-15','15-18','>18')

# Make a vector of colours 'Clrs' for to match each range
Clrs <- c("grey50","dodgerblue","forestgreen","orange","red","purple","magenta")

# Make up lookup dataframe 'LkUp' of the lables and colours 
LkUp <- data.frame(cbind(Lbls,Clrs),stringsAsFactors = FALSE)

# Add a new variable 'Lbls' the grid dataframe mapping the labels based on z-value
Grd$Lbls <- as.character(cut(Grd$z, breaks = Brks, labels = Lbls))

# Add a new variable 'Clrs' to the grid dataframe based on the Lbls field in the grid and lookup table
Grd <- merge(Grd,LkUp, by.x = 'Lbls')

# Plot the grid using the 'Clrs' field for the colour of each point
plot(Grd$Var1,
     Grd$Var2,
     xlim = c(0,400),
     ylim = c(0,400),
     cex = 1.0,
     col = Grd$Clrs,
     pch = 20,
     xlab = 'mX',
     ylab = 'mY',
     main = 'My Grid',
     axes = FALSE,
     labels = FALSE,
     las = 1
)

axis(1,seq(0,400,100))
axis(2,seq(0,400,100),las = 1)
box(col = 'black')

legend("topleft", legend = Lbls, fill = Clrs, title = 'Z')

How to delete from a text file, all lines that contain a specific string?

cat filename | grep -v "pattern" > filename.1
mv filename.1 filename

What is the difference between #import and #include in Objective-C?

There seems to be a lot of confusion regarding the preprocessor.

What the compiler does when it sees a #include that it replaces that line with the contents of the included files, no questions asked.

So if you have a file a.h with this contents:

typedef int my_number;

and a file b.c with this content:

#include "a.h"
#include "a.h"

the file b.c will be translated by the preprocessor before compilation to

typedef int my_number;
typedef int my_number;

which will result in a compiler error, since the type my_number is defined twice. Even though the definition is the same this is not allowed by the C language.

Since a header often is used in more than one place include guards usually are used in C. This looks like this:

 #ifndef _a_h_included_
 #define _a_h_included_

 typedef int my_number;

 #endif

The file b.c still would have the whole contents of the header in it twice after being preprocessed. But the second instance would be ignored since the macro _a_h_included_ would already have been defined.

This works really well, but has two drawbacks. First of all the include guards have to be written, and the macro name has to be different in every header. And secondly the compiler has still to look for the header file and read it as often as it is included.

Objective-C has the #import preprocessor instruction (it also can be used for C and C++ code with some compilers and options). This does almost the same as #include, but it also notes internally which file has already been included. The #import line is only replaced by the contents of the named file for the first time it is encountered. Every time after that it is just ignored.

Import .bak file to a database in SQL server

Instead of choosing Restore Database..., select Restore Files and Filegroups...

Then enter a database name, select your .bak file path as the source, check the restore checkbox, and click Ok. If the .bak file is valid, it will work.

(The SQL Server restore option names are not intuitive for what should a very simple task.)

Is it possible to get the index you're sorting over in Underscore.js?

The iterator of _.each is called with 3 parameters (element, index, list). So yes, for _.each you cab get the index.

You can do the same in sortBy

Force LF eol in git repo and working copy

To force LF line endings for all text files, you can create .gitattributes file in top-level of your repository with the following lines (change as desired):

# Ensure all C and PHP files use LF.
*.c         eol=lf
*.php       eol=lf

which ensures that all files that Git considers to be text files have normalized (LF) line endings in the repository (normally core.eol configuration controls which one do you have by default).

Based on the new attribute settings, any text files containing CRLFs should be normalized by Git. If this won't happen automatically, you can refresh a repository manually after changing line endings, so you can re-scan and commit the working directory by the following steps (given clean working directory):

$ echo "* text=auto" >> .gitattributes
$ rm .git/index     # Remove the index to force Git to
$ git reset         # re-scan the working directory
$ git status        # Show files that will be normalized
$ git add -u
$ git add .gitattributes
$ git commit -m "Introduce end-of-line normalization"

or as per GitHub docs:

git add . -u
git commit -m "Saving files before refreshing line endings"
git rm --cached -r . # Remove every file from Git's index.
git reset --hard # Rewrite the Git index to pick up all the new line endings.
git add . # Add all your changed files back, and prepare them for a commit.
git commit -m "Normalize all the line endings" # Commit the changes to your repository.

See also: @Charles Bailey post.

In addition, if you would like to exclude any files to not being treated as a text, unset their text attribute, e.g.

manual.pdf      -text

Or mark it explicitly as binary:

# Denote all files that are truly binary and should not be modified.
*.png binary
*.jpg binary

To see some more advanced git normalization file, check .gitattributes at Drupal core:

# Drupal git normalization
# @see https://www.kernel.org/pub/software/scm/git/docs/gitattributes.html
# @see https://www.drupal.org/node/1542048

# Normally these settings would be done with macro attributes for improved
# readability and easier maintenance. However macros can only be defined at the
# repository root directory. Drupal avoids making any assumptions about where it
# is installed.

# Define text file attributes.
# - Treat them as text.
# - Ensure no CRLF line-endings, neither on checkout nor on checkin.
# - Detect whitespace errors.
#   - Exposed by default in `git diff --color` on the CLI.
#   - Validate with `git diff --check`.
#   - Deny applying with `git apply --whitespace=error-all`.
#   - Fix automatically with `git apply --whitespace=fix`.

*.config  text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.css     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.dist    text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.engine  text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.html    text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=html
*.inc     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.install text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.js      text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.json    text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.lock    text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.map     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.md      text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.module  text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.php     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.po      text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.profile text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.script  text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.sh      text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.sql     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.svg     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.theme   text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2 diff=php
*.twig    text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.txt     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.xml     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2
*.yml     text eol=lf whitespace=blank-at-eol,-blank-at-eof,-space-before-tab,tab-in-indent,tabwidth=2

# Define binary file attributes.
# - Do not treat them as text.
# - Include binary diff in patches instead of "binary files differ."
*.eot     -text diff
*.exe     -text diff
*.gif     -text diff
*.gz      -text diff
*.ico     -text diff
*.jpeg    -text diff
*.jpg     -text diff
*.otf     -text diff
*.phar    -text diff
*.png     -text diff
*.svgz    -text diff
*.ttf     -text diff
*.woff    -text diff
*.woff2   -text diff

See also:

Stretch background image css?

CSS3: http://webdesign.about.com/od/styleproperties/p/blspbgsize.htm

.style1 {
  ...
  background-size: 100%;
}

You can specify just width or height with:

background-size: 100% 50%;

Which will stretch it 100% of the width and 50% of the height.


Browser support: http://caniuse.com/#feat=background-img-opts

regular expression to match exactly 5 digits

My test string for the following:

testing='12345,abc,123,54321,ab15234,123456,52341';

If I understand your question, you'd want ["12345", "54321", "15234", "52341"].

If JS engines supported regexp lookbehinds, you could do:

testing.match(/(?<!\d)\d{5}(?!\d)/g)

Since it doesn't currently, you could:

testing.match(/(?:^|\D)(\d{5})(?!\d)/g)

and remove the leading non-digit from appropriate results, or:

pentadigit=/(?:^|\D)(\d{5})(?!\d)/g;
result = [];
while (( match = pentadigit.exec(testing) )) {
    result.push(match[1]);
}

Note that for IE, it seems you need to use a RegExp stored in a variable rather than a literal regexp in the while loop, otherwise you'll get an infinite loop.

Error: Uncaught (in promise): Error: Cannot match any routes Angular 2

I am using angular 4 and faced the same issue apply, all possible solution but finally, this solve my problem

export class AppRoutingModule {
constructor(private router: Router) {
    this.router.errorHandler = (error: any) => {
        this.router.navigate(['404']); // or redirect to default route
    }
  }
}

Hope this will help you.

Unable to login to SQL Server + SQL Server Authentication + Error: 18456

You need to enable SQL Server Authentication:

  1. In the Object Explorer, right click on the server and click on "Properties"

DBMS Properties dialog

  1. In the "Server Properties" window click on "Security" in the list of pages on the left. Under "Server Authentication" choose the "SQL Server and Windows Authentication mode" radio option.

SQL Server Authentication dialog

  1. Restart the SQLEXPRESS service.

How do I change file permissions in Ubuntu

Add -R for recursive:

sudo chmod -R 666 /var/www

Cannot create Maven Project in eclipse

For me the solution was a bit simpler, I just had to clean the repository : .m2/repository/org/apache/maven/archetypes

Why am I getting string does not name a type Error?

Try a using namespace std; at the top of game.h or use the fully-qualified std::string instead of string.

The namespace in game.cpp is after the header is included.

How can I create a small color box using html and css?

You can create these easily using the floating ability of CSS, for example. I have created a small example on Jsfiddle over here, all the related css and html is also provided there.

_x000D_
_x000D_
.foo {_x000D_
  float: left;_x000D_
  width: 20px;_x000D_
  height: 20px;_x000D_
  margin: 5px;_x000D_
  border: 1px solid rgba(0, 0, 0, .2);_x000D_
}_x000D_
_x000D_
.blue {_x000D_
  background: #13b4ff;_x000D_
}_x000D_
_x000D_
.purple {_x000D_
  background: #ab3fdd;_x000D_
}_x000D_
_x000D_
.wine {_x000D_
  background: #ae163e;_x000D_
}
_x000D_
<div class="foo blue"></div>_x000D_
<div class="foo purple"></div>_x000D_
<div class="foo wine"></div>
_x000D_
_x000D_
_x000D_

What is the difference between UNION and UNION ALL?

UNION removes duplicate records in other hand UNION ALL does not. But one need to check the bulk of data that is going to be processed and the column and data type must be same.

since union internally uses "distinct" behavior to select the rows hence it is more costly in terms of time and performance. like

select project_id from t_project
union
select project_id from t_project_contact  

this gives me 2020 records

on other hand

select project_id from t_project
union all
select project_id from t_project_contact

gives me more than 17402 rows

on precedence perspective both has same precedence.

How to sign in kubernetes dashboard?

TL;DR

To get the token in a single oneliner:

kubectl -n kube-system describe secret $(kubectl -n kube-system get secret | awk '/^deployment-controller-token-/{print $1}') | awk '$1=="token:"{print $2}'

This assumes that your ~/.kube/config is present and valid. And also that kubectl config get-contexts indicates that you are using the correct context (cluster and namespace) for the dashboard you are logging into.

Explanation

I derived this answer from what I learned from @silverfox's answer. That is a very informative write up. Unfortunately it falls short of telling you how to actually put the information into practice. Maybe I've been doing DevOps too long, but I think in shell. It's much more difficult for me to learn or teach in English.

Here is that oneliner with line breaks and indents for readability:

kubectl -n kube-system describe secret $(
  kubectl -n kube-system get secret | \
  awk '/^deployment-controller-token-/{print $1}'
) | \
awk '$1=="token:"{print $2}'

There are 4 distinct commands and they get called in this order:

  • Line 2 - This is the first command from @silverfox's Token section.
  • Line 3 - Print only the first field of the line beginning with deployment-controller-token- (which is the pod name)
  • Line 1 - This is the second command from @silverfox's Token section.
  • Line 5 - Print only the second field of the line whose first field is "token:"

require_once :failed to open stream: no such file or directory

It says that the file C:\wamp\www\mysite\php\includes\dbconn.inc doesn't exist, so the error is, you're missing the file.

How to convert a unix timestamp (seconds since epoch) to Ruby DateTime?

Sorry, brief moment of synapse failure. Here's the real answer.

require 'date'

Time.at(seconds_since_epoch_integer).to_datetime

Brief example (this takes into account the current system timezone):

$ date +%s
1318996912

$ irb

ruby-1.9.2-p180 :001 > require 'date'
 => true 

ruby-1.9.2-p180 :002 > Time.at(1318996912).to_datetime
 => #<DateTime: 2011-10-18T23:01:52-05:00 (13261609807/5400,-5/24,2299161)> 

Further update (for UTC):

ruby-1.9.2-p180 :003 > Time.at(1318996912).utc.to_datetime
 => #<DateTime: 2011-10-19T04:01:52+00:00 (13261609807/5400,0/1,2299161)>

Recent Update: I benchmarked the top solutions in this thread while working on a HA service a week or two ago, and was surprised to find that Time.at(..) outperforms DateTime.strptime(..) (update: added more benchmarks).

# ~ % ruby -v
#  => ruby 2.1.5p273 (2014-11-13 revision 48405) [x86_64-darwin13.0]

irb(main):038:0> Benchmark.measure do
irb(main):039:1*   ["1318996912", "1318496912"].each do |s|
irb(main):040:2*     DateTime.strptime(s, '%s')
irb(main):041:2>   end
irb(main):042:1> end

=> #<Benchmark ... @real=2.9e-05 ... @total=0.0>

irb(main):044:0> Benchmark.measure do
irb(main):045:1>   [1318996912, 1318496912].each do |i|
irb(main):046:2>     DateTime.strptime(i.to_s, '%s')
irb(main):047:2>   end
irb(main):048:1> end

=> #<Benchmark ... @real=2.0e-05 ... @total=0.0>

irb(main):050:0* Benchmark.measure do
irb(main):051:1*   ["1318996912", "1318496912"].each do |s|
irb(main):052:2*     Time.at(s.to_i).to_datetime
irb(main):053:2>   end
irb(main):054:1> end

=> #<Benchmark ... @real=1.5e-05 ... @total=0.0>

irb(main):056:0* Benchmark.measure do
irb(main):057:1*   [1318996912, 1318496912].each do |i|
irb(main):058:2*     Time.at(i).to_datetime
irb(main):059:2>   end
irb(main):060:1> end

=> #<Benchmark ... @real=2.0e-05 ... @total=0.0>

Foreign key referring to primary keys across multiple tables?

You can probably add two foreign key constraints (honestly: I've never tried it), but it'd then insist the parent row exist in both tables.

Instead you probably want to create a supertype for your two employee subtypes, and then point the foreign key there instead. (Assuming you have a good reason to split the two types of employees, of course).

                 employee       
employees_ce     ————————       employees_sn
————————————     type           ————————————
empid —————————> empid <——————— empid
name               /|\          name
                    |  
                    |  
      deductions    |  
      ——————————    |  
      empid ————————+  
      name

type in the employee table would be ce or sn.

How to pass arguments to Shell Script through docker run

If you want to run it @build time :

CMD /bin/bash /file.sh arg1

if you want to run it @run time :

ENTRYPOINT ["/bin/bash"]
CMD ["/file.sh", "arg1"]

Then in the host shell

docker build -t test .
docker run -i -t test

How to load a resource from WEB-INF directory of a web archive

Here is how it works for me with no Servlet use.

Let's say I am trying to access web.xml in project/WebContent/WEB-INF/web.xml

  1. In project property Source-tab add source folder by pointing to the parent container for WEB-INF folder (in my case WebContent )

  2. Now let's use class loader:

    InputStream inStream = class.getClass().getClassLoader().getResourceAsStream("Web-INF/web.xml")
    

form_for but to post to a different action

new syntax

<%= form_for :user, url: custom_user_path, method: :post do |f|%>
<%end%>

How to limit text width

I think what you are trying to do is to wrap long text without spaces.

look at this :Hyphenator.js and it's demo.

How to access /storage/emulated/0/

In Emulator, to view this file click on Settings>Storage>Other>Android>data>com.companyname.textapp>file>Download. Here, textapp is the name of the app you are working on.

Dynamic require in RequireJS, getting "Module name has not been loaded yet for context" error?

The limitation relates to the simplified CommonJS syntax vs. the normal callback syntax:

Loading a module is inherently an asynchronous process due to the unknown timing of downloading it. However, RequireJS in emulation of the server-side CommonJS spec tries to give you a simplified syntax. When you do something like this:

var foomodule = require('foo');
// do something with fooModule

What's happening behind the scenes is that RequireJS is looking at the body of your function code and parsing out that you need 'foo' and loading it prior to your function execution. However, when a variable or anything other than a simple string, such as your example...

var module = require(path); // Call RequireJS require

...then Require is unable to parse this out and automatically convert it. The solution is to convert to the callback syntax;

var moduleName = 'foo';
require([moduleName], function(fooModule){
    // do something with fooModule
})

Given the above, here is one possible rewrite of your 2nd example to use the standard syntax:

define(['dyn_modules'], function (dynModules) {
    require(dynModules, function(){
        // use arguments since you don't know how many modules you're getting in the callback
        for (var i = 0; i < arguments.length; i++){
            var mymodule = arguments[i];
            // do something with mymodule...
        }
    });

});

EDIT: From your own answer, I see you're using underscore/lodash, so using _.values and _.object can simplify the looping through arguments array as above.

What is the Python equivalent of Matlab's tic and toc functions?

This can also be done using a wrapper. Very general way of keeping time.

The wrapper in this example code wraps any function and prints the amount of time needed to execute the function:

def timethis(f):
    import time

    def wrapped(*args, **kwargs):
        start = time.time()
        r = f(*args, **kwargs)
        print "Executing {0} took {1} seconds".format(f.func_name,  time.time()-start)
        return r
    return wrapped

@timethis
def thistakestime():
    for x in range(10000000):
        pass

thistakestime()

Better naming in Tuple classes than "Item1", "Item2"

Just to add to @MichaelMocko answer. Tuples have couple of gotchas at the moment:

You can't use them in EF expression trees

Example:

public static (string name, string surname) GetPersonName(this PersonContext ctx, int id)
{
    return ctx.Persons
        .Where(person => person.Id == id)
        // Selecting as Tuple
        .Select(person => (person.Name, person.Surname))
        .First();
}

This will fail to compile with "An expression tree may not contain a tuple literal" error. Unfortunately, the expression trees API wasn't expanded with support for tuples when these were added to the language.

Track (and upvote) this issue for the updates: https://github.com/dotnet/roslyn/issues/12897

To get around the problem, you can cast it to anonymous type first and then convert the value to tuple:

// Will work
public static (string name, string surname) GetPersonName(this PersonContext ctx, int id)
{
    return ctx.Persons
        .Where(person => person.Id == id)
        .Select(person => new { person.Name, person.Surname })
        .ToList()
        .Select(person => (person.Name, person.Surname))
        .First();
}

Another option is to use ValueTuple.Create:

// Will work
public static (string name, string surname) GetPersonName(this PersonContext ctx, int id)
{
    return ctx.Persons
        .Where(person => person.Id == id)
        .Select(person => ValueTuple.Create(person.Name, person.Surname))
        .First();
}

References:

You can't deconstruct them in lambdas

There's a proposal to add the support: https://github.com/dotnet/csharplang/issues/258

Example:

public static IQueryable<(string name, string surname)> GetPersonName(this PersonContext ctx, int id)
{
    return ctx.Persons
        .Where(person => person.Id == id)
        .Select(person => ValueTuple.Create(person.Name, person.Surname));
}

// This won't work
ctx.GetPersonName(id).Select((name, surname) => { return name + surname; })

// But this will
ctx.GetPersonName(id).Select(t => { return t.name + t.surname; })

References:

They won't serialize nicely

using System;
using Newtonsoft.Json;

public class Program
{
    public static void Main() {
        var me = (age: 21, favoriteFood: "Custard");
        string json = JsonConvert.SerializeObject(me);

        // Will output {"Item1":21,"Item2":"Custard"}
        Console.WriteLine(json); 
    }
}

Tuple field names are only available at compile time and are completely wiped out at runtime.

References:

Align div right in Bootstrap 3

i think you try to align the content to the right within the div, the div with offset already push itself to the right, here some code and LIVE sample:
FYI: .pull-right only push the div to the right, but not the content inside the div.

HTML:

<div class="row">
  <div class="container">
    <div class="col-md-4 someclass">
      left content
    </div>
    <div class="col-md-4 col-md-offset-4 someclass">
      <div class="yellow_background totheright">right content</div>
    </div>
  </div>
</div>

CSS:

.someclass{ /*this class for testing purpose only*/
    border:1px solid blue;
    line-height:2em;
}

.totheright{ /*this will align the text to the right*/
  text-align:right;
}

.yellow_background{
    background-color:yellow;
}

Another modification:

...
<div class="yellow_background totheright">
  <span>right content</span>
  <br/>image also align-right<br/>
  <img width="15%" src="https://www.google.com/images/srpr/logo11w.png"/>
</div>
...

hope it will clear your problem

changing permission for files and folder recursively using shell command in mac

By using CHMOD yes:

For Recursive file:

chmod -R 777 foldername or pathname

For non recursive:

chmod 777 foldername or pathname

Is the MIME type 'image/jpg' the same as 'image/jpeg'?

For those it might help, I use this list as a reference to define my content-type when I have to deal with images on my app.

It says that jpg extension can be declared with Content-type : image/jpeg

There isn't any image/jpg attribute for content-type.

How to automate browsing using python?

I have found the iMacros Firefox plugin (which is free) to work very well.

It can be automated with Python using Windows COM object interfaces. Here's some example code from http://wiki.imacros.net/Python. It requires Python Windows Extensions:

import win32com.client
def Hello():
    w=win32com.client.Dispatch("imacros")
    w.iimInit("", 1)
    w.iimPlay("Demo\\FillForm")
if __name__=='__main__':
    Hello()

jQuery checkbox onChange

There is a typo error :

$('#activelist :checkbox')...

Should be :

$('#inactivelist:checkbox')...

No Main class found in NetBeans

In project properties, under the run tab, specify your main class. Moreover, To avoid this issue, you need to check "Create main class" during creating new project. Specifying main class in properties should always work, but if in some rare case it doesn't work, then the issue could be resolved by re-creating the project and not forgetting to check "Create main class" if it is unchecked.

How to install all required PHP extensions for Laravel?

Laravel Server Requirements mention that BCMath, Ctype, JSON, Mbstring, OpenSSL, PDO, Tokenizer, and XML extensions are required. Most of the extensions are installed and enabled by default.

You can run the following command in Ubuntu to make sure the extensions are installed.

sudo apt install openssl php-common php-curl php-json php-mbstring php-mysql php-xml php-zip

PHP version specific installation (if PHP 7.4 installed)

sudo apt install php7.4-common php7.4-bcmath openssl php7.4-json php7.4-mbstring

You may need other PHP extensions for your composer packages. Find from links below.

PHP extensions for Ubuntu 20.04 LTS (Focal Fossa)

PHP extensions for Ubuntu 18.04 LTS (Bionic)

PHP extensions for Ubuntu 16.04 LTS (Xenial)

How to prevent page scrolling when scrolling a DIV element?

All you need is

e.preventDefault();

on child element.

What are ODEX files in Android?

The blog article is mostly right, but not complete. To have a full understanding of what an odex file does, you have to understand a little about how application files (APK) work.

Applications are basically glorified ZIP archives. The java code is stored in a file called classes.dex and this file is parsed by the Dalvik JVM and a cache of the processed classes.dex file is stored in the phone's Dalvik cache.

An odex is basically a pre-processed version of an application's classes.dex that is execution-ready for Dalvik. When an application is odexed, the classes.dex is removed from the APK archive and it does not write anything to the Dalvik cache. An application that is not odexed ends up with 2 copies of the classes.dex file--the packaged one in the APK, and the processed one in the Dalvik cache. It also takes a little longer to launch the first time since Dalvik has to extract and process the classes.dex file.

If you are building a custom ROM, it's a really good idea to odex both your framework JAR files and the stock apps in order to maximize the internal storage space for user-installed apps. If you want to theme, then simply deodex -> apply your theme -> reodex -> release.

To actually deodex, use small and baksmali:

https://github.com/JesusFreke/smali/wiki/DeodexInstructions

Standard deviation of a list

Here's some pure-Python code you can use to calculate the mean and standard deviation.

All code below is based on the statistics module in Python 3.4+.

def mean(data):
    """Return the sample arithmetic mean of data."""
    n = len(data)
    if n < 1:
        raise ValueError('mean requires at least one data point')
    return sum(data)/n # in Python 2 use sum(data)/float(n)

def _ss(data):
    """Return sum of square deviations of sequence data."""
    c = mean(data)
    ss = sum((x-c)**2 for x in data)
    return ss

def stddev(data, ddof=0):
    """Calculates the population standard deviation
    by default; specify ddof=1 to compute the sample
    standard deviation."""
    n = len(data)
    if n < 2:
        raise ValueError('variance requires at least two data points')
    ss = _ss(data)
    pvar = ss/(n-ddof)
    return pvar**0.5

Note: for improved accuracy when summing floats, the statistics module uses a custom function _sum rather than the built-in sum which I've used in its place.

Now we have for example:

>>> mean([1, 2, 3])
2.0
>>> stddev([1, 2, 3]) # population standard deviation
0.816496580927726
>>> stddev([1, 2, 3], ddof=1) # sample standard deviation
0.1

Unix command-line JSON parser?

I just made jkid which is a small command-line json explorer that I made to easily explore big json objects. Objects can be explored "transversally" and a "preview" option is there to avoid console overflow.

$  echo '{"john":{"size":20, "eyes":"green"}, "bob":{"size":30, "eyes":"brown"}}' > test3.json
$  jkid . eyes test3.json 
object[.]["eyes"]
{
  "bob": "brown", 
  "john": "green"
}

Using the RUN instruction in a Dockerfile with 'source' does not work

I had the same problem and in order to execute pip install inside virtualenv I had to use this command:

RUN pip install virtualenv virtualenvwrapper
RUN mkdir -p /opt/virtualenvs
ENV WORKON_HOME /opt/virtualenvs
RUN /bin/bash -c "source /usr/local/bin/virtualenvwrapper.sh \
    && mkvirtualenv myapp \
    && workon myapp \
    && pip install -r /mycode/myapp/requirements.txt"

I hope it helps.

Cannot obtain value of local or argument as it is not available at this instruction pointer, possibly because it has been optimized away

In my case, I was working on a web api project and although the project was set correctly to full debug, I was still seeing this error every time I attached to the IIS process I was trying to debug. Then I realized the publish profile was set to use the Release configuration. So one more place to check is your publish profile if you're using the 'Publish' feature of your dotnet web api project.

jQuery: Can I call delay() between addClass() and such?

You can create a new queue item to do your removing of the class:

$("#div").addClass("error").delay(1000).queue(function(next){
    $(this).removeClass("error");
    next();
});

Or using the dequeue method:

$("#div").addClass("error").delay(1000).queue(function(){
    $(this).removeClass("error").dequeue();
});

The reason you need to call next or dequeue is to let jQuery know that you are done with this queued item and that it should move on to the next one.

Getting the last revision number in SVN?

$ svn log | head -10 on whatever directory that has a .svn folder

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

I believe what you want is:

SELECT ItemName, GROUP_CONCAT(DepartmentId) FROM table_name GROUP BY ItemName

If you're using MySQL

Reference

No 'Access-Control-Allow-Origin' header is present on the requested resource error

Try this - set Ajax call by setting up the header as follows:

var uri = "http://localhost:50869/odata/mydatafeeds"
$.ajax({
    url: uri,
    beforeSend: function (request) {
        request.setRequestHeader("Authorization", "Negotiate");
    },
    async: true,
    success: function (data) {
        alert(JSON.stringify(data));
    },
    error: function (xhr, textStatus, errorMessage) {
        alert(errorMessage);
    }                
});

Then run your code by opening Chrome with the following command line:

chrome.exe --user-data-dir="C:/Chrome dev session" --disable-web-security

Favicon: .ico or .png / correct tags?

For compatibility with all browsers stick with .ico.

.png is getting more and more support though as it is easier to create using multiple programs.

for .ico

<link rel="shortcut icon" href="http://example.com/myicon.ico" />

for .png, you need to specify the type

<link rel="icon" type="image/png" href="http://example.com/image.png" />

After installation of Gulp: “no command 'gulp' found”

I'm on lubuntu 19.10

I've used combination of previous answers, and didn't tweak the $PATH.

  1. npm uninstall --global gulp gulp-cli This removes any package if they are already there.
  2. sudo npm install --global gulp-cli Reinstall it as root user.

If you want to do copy and paste

npm uninstall --global gulp gulp-cli && sudo npm install --global gulp-cli 

should work

I guess --global is unnecessary here as it's installed using sudo, but I've used it just in case.

How to tell if homebrew is installed on Mac OS X

In my case Mac OS High Sierra 10.13.6

brew -v

OutPut-
Homebrew 2.2.2
Homebrew/homebrew-core (git revision 71aa; last commit 2020-01-07)
Homebrew/homebrew-cask (git revision 84f00; last commit 2020-01-07)

Will the IE9 WebBrowser Control Support all of IE9's features, including SVG?

Regarding whitehawk's accepted answer. I am just trying to add a bit hands on experience. Was just trying to add a comments, but SO complains it's too long.

Basically, without IE 9 installed, the registry switch FEATURE_BROWSER_EMULATION won't work AT ALL.

For example, my own experience today I was trying to get the .net webcontrol to work with IE10 mode because one html I am trying to render won't work with .netControl under VS2012, and not even work when I load the html to IE8 directly, still css won't render properly(even after I say allow blocked content). But I have tested the same html ok with IE10 on a friend's win 8 machine. That's why I am trying to set the .net webControl to IE 10 mode but just keeps failing...

Now I figured this is bcos my win 7 machine only have IE8 installed, so regardless which value I set to the FEATURE_BROWSER_EMULATION switch(value to IE9, IE10 IE11), it just won't work AT ALL !

Then I downloaded and installed IE 10 on my win 7 machine. Still it won't work, then I added the FEATURE_BROWSER_EMULATION, it started working !

Also I noticed regardless which value I set , even set it to value 0 by default, the webControl is still using IE 10 mode which still works for me.

So to summarise, If you have IE X installed but you want your .Net webControl to work under IE (X+N) N>0 modo, TWO things you need to do:

  1. Go to MS website & download and install IE (X+N) on your machine, you will need to reboot after installation.

  2. apply whitehawk's answer.

Basically: To control the value of this feature by using the registry, add the name of your executable file to the following setting and set the value to match the desired setting.

HKEY_LOCAL_MACHINE (or HKEY_CURRENT_USER)
   SOFTWARE
      Microsoft
         Internet Explorer
            Main
               FeatureControl
                  FEATURE_BROWSER_EMULATION
                     contoso.exe = (DWORD) 00009000

Windows Internet Explorer 8 and later. The FEATURE_BROWSER_EMULATION feature defines the default emulation mode for Internet Explorer and supports the following values.

Value Description

  • 11001 (0x2AF9 Internet Explorer 11. Webpages are displayed in IE11 edge mode, regardless of the !DOCTYPE directive.

    11000 (0x2AF8) IE11. Webpages containing standards-based !DOCTYPE directives are displayed in IE11 edge mode. Default value for IE11.

    10001 (0x2711) Internet Explorer 10. Webpages are displayed in IE10 Standards mode, regardless of the !DOCTYPE directive.

    10000 (0x02710) Internet Explorer 10. Webpages containing standards-based !DOCTYPE directives are displayed in IE10 Standards mode. Default value for Internet Explorer 10.

    9999 (0x270F) Windows Internet Explorer 9. Webpages are displayed in IE9 Standards mode, regardless of the !DOCTYPE directive.

    9000 (0x2328) Internet Explorer 9. Webpages containing standards-based !DOCTYPE directives are displayed in IE9 mode. Default value for Internet Explorer 9.

    Important In Internet Explorer 10, Webpages containing standards-based !DOCTYPE directives are displayed in IE10 Standards mode.

    8888 (0x22B8) Webpages are displayed in IE8 Standards mode, regardless of the !DOCTYPE directive.

    8000 (0x1F40) Webpages containing standards-based !DOCTYPE directives are displayed in IE8 mode. Default value for Internet Explorer 8 Important In Internet Explorer 10, Webpages containing standards-based !DOCTYPE directives are displayed in IE10 Standards mode.

    7000 (0x1B58) Webpages containing standards-based !DOCTYPE directives are displayed in IE7 Standards mode. Default value for applications hosting the WebBrowser Control.

Full ref here

Using Jquery Datatable with AngularJs

For AngularJs you have to use "angular-datatables.min.js" file for datatable settings. You will get this from http://l-lin.github.io/angular-datatables/#/welcome.

After that you can write code like below,

<script>
     var app = angular.module('AngularWayApp', ['datatables']);
</script>

<div ng-app="AngularWayApp" ng-controller="AngularWayCtrl">
  <table id="example" datatable="ng" class="table">
                                    <thead>
                                        <tr>
                                            <th><b>UserID</b></th>
                                            <th><b>Firstname</b></th>
                                            <th><b>Lastname</b></th>
                                            <th><b>Email</b></th>
                                            <th><b>Actions</b></th>
                                        </tr>
                                    </thead>
                                    <tbody>
                                        <tr ng-repeat="user in users" ng-click="testingClick(user)">
                                            <td>
                                                {{user.UserId}}
                                            </td>
                                            <td>
                                                {{user.FirstName}}
                                            </td>
                                            <td>
                                                {{user.Lastname}}
                                            </td>
                                            <td>
                                                {{user.Email}}
                                            </td>
                                            <td>
                                                <span ng-click="editUser(user)" style="color:blue;cursor: pointer; font-weight:500; font-size:15px" class="btnAdd" data-toggle="modal" data-target="#myModal">Edit</span> &nbsp;&nbsp; | &nbsp;&nbsp;
                                                <span ng-click="deleteUser(user)" style="color:red; cursor: pointer; font-weight:500; font-size:15px" class="btnRed">Delete</span>
                                            </td>
                                        </tr>
                                    </tbody>
                                </table>
                                </div>

How to get input text value from inside td

I'm having a hard time figuring out what exactly you're looking for here, so hope I'm not way off base.

I'm assuming what you mean is that when a keyup event occurs on the input with class "start" you want to get the values of all the inputs in neighbouring <td>s:

    $('.start').keyup(function() {
        var otherInputs = $(this).parents('td').siblings().find('input');

        for(var i = 0; i < otherInputs.length; i++) {
            alert($(otherInputs[i]).val());
        }
        return false;
    });

How to use \n new line in VB msgbox() ...?

msgbox("your text here" & Environment.NewLine & "more text") is the easist way. no point in making your code harder or more ocmplicated than you need it to be...

missing private key in the distribution certificate on keychain

I got into this situation ("Missing private key.") after Xcode failed to create new distribution certificate - an unknown error occurred.

Then, I struggled to obtain the private key or to generate new certificate. From the certificate manager in Xcode I got strange errors like "The passphrase you entered is wrong". But it did not even ask me for any passphrase.

What helped me was:

  1. Revoke all not-working distribution certificates at developer.apple.com
  2. Restart my Mac

After that, Xcode was able to create new distribution certificate and no private key was missing.

Lesson learned: Restart your Mac as much as your Windows ;)

DateTime.Now.ToShortDateString(); replace month and day

Little addition to Jason's answer:

  1. The ToShortDateString() is culture-sensitive.

From MSDN:

The string returned by the ToShortDateString method is culture-sensitive. It reflects the pattern defined by the current culture's DateTimeFormatInfo object. For example, for the en-US culture, the standard short date pattern is "M/d/yyyy"; for the de-DE culture, it is "dd.MM.yyyy"; for the ja-JP culture, it is "yyyy/M/d". The specific format string on a particular computer can also be customized so that it differs from the standard short date format string.

That's mean it's better to use the ToString() method and define format explicitly (as Jason said). Although if this string appeas in UI the ToShortDateString() is a good solution because it returns string which is familiar to a user.

  1. If you need just today's date you can use DateTime.Today.

From inside of a Docker container, how do I connect to the localhost of the machine?

None of the answers worked for me when using Docker Toolbox on Windows 10 Home, but 10.0.2.2 did, since it uses VirtualBox which exposes the host to the VM on this address.

How to get today's Date?

Code To Get Today's date in any specific Format

You can define the desired format in SimpleDateFormat instance to get the date in that specific formate

 DateFormat dateFormat = new SimpleDateFormat("MM/dd/yyyy");
        Calendar cal = Calendar.getInstance();
        Date date = cal.getTime();
        String todaysdate = dateFormat.format(date);
         System.out.println("Today's date : " + todaysdate);

Follow below links to see the valid date format combination.

https://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html

CODE : To get x days ahead or Previous from Today's date, To get the past date or Future date.

For Example :

Today date : 11/27/2018

xdayFromTodaysDate = 2 to get date as 11/29/2018

xdayFromTodaysDate = -2 to get date as 11/25/2018

  public String getAniversaryDate(int xdayFromTodaysDate ){

        DateFormat dateFormat = new SimpleDateFormat("MM/dd/yyyy");
        Calendar cal = Calendar.getInstance();
        Date date = cal.getTime();
        cal.setTime(date);
        cal.add(Calendar.DAY_OF_MONTH,xdayFromTodaysDate);
        date = cal.getTime();
        String aniversaryDate = dateFormat.format(date);
        LOGGER.info("Today's date : " + todaysdate);
          return aniversaryDate;

    }

CODE : To get x days ahead or Previous from a Given date

  public String getAniversaryDate(String givendate, int xdayFromTodaysDate ){


        Calendar cal = Calendar.getInstance();
        DateFormat dateFormat = new SimpleDateFormat("MM/dd/yyyy");
        try {
            Date date = dateFormat.parse(givendate);
            cal.setTime(date);
            cal.add(Calendar.DAY_OF_MONTH,xdayFromTodaysDate);
            date = cal.getTime();
            String aniversaryDate = dateFormat.format(date);
            LOGGER.info("aniversaryDate : " + aniversaryDate);
            return aniversaryDate;
        } catch (ParseException e) {
            e.printStackTrace();
            return null;
        }

    }

How to fix error "Updating Maven Project". Unsupported IClasspathEntry kind=4?

Upgrading from Kepler to Luna worked for me.

I had just added some components for Java 1.8 support. It seems that they where not as compatible as I would like or that I mixed the wrong ones. It really caused a lot of problems. Trying to update the system reported errors as they couldn't fulfill some dependencies. Maven upgrades didn't work. Tried a lot of things.

So, if there is no reason to avoid the upgrade just add the luna repository to avalilable software sites (Luna http://download.eclipse.org/releases/luna/ ) and "check for updates". It is better to have all the components with the same version and there are some nice new features.

Update R using RStudio

If you're using a Mac computer, you can use the new updateR package to update the R version from RStudio: http://www.andreacirillo.com/2018/02/10/updater-package-update-r-version-with-a-function-on-mac-osx/

In summary, you need to perform this:

To update your R version from within Rstudio using updateR you just have to run these five lines of code:

install.packages('devtools') #assuming it is not already installed
library(devtools)
install_github('andreacirilloac/updateR')
library(updateR)
updateR(admin_password = 'Admin user password')

at the end of installation process a message is going to confirm you the happy end:

everything went smoothly
open a Terminal session and run 'R' to assert that latest version was installed

How to vertically center <div> inside the parent element with CSS?

I found this site useful: http://www.vanseodesign.com/css/vertical-centering/ This worked for me:

HTML

<div id="parent">
    <div id="child">Content here</div>
</div>

CSS

#parent {
    padding: 5% 0;
}

#child {
    padding: 10% 0;
}

Live search through table rows

François Wahl approach, but a bit shorter:

$("#search").keyup(function() {
    var value = this.value;

    $("table").find("tr").each(function(index) {
        if (!index) return;
        var id = $(this).find("td").first().text();
        $(this).toggle(id.indexOf(value) !== -1);
    });
});

http://jsfiddle.net/ARTsinn/CgFd9/

How to get primary key column in Oracle?

Same as the answer from 'Richie' but a bit more concise.

  1. Query for user constraints only

    SELECT column_name FROM all_cons_columns WHERE constraint_name = (
      SELECT constraint_name FROM user_constraints 
      WHERE UPPER(table_name) = UPPER('tableName') AND CONSTRAINT_TYPE = 'P'
    );
    
  2. Query for all constraints

    SELECT column_name FROM all_cons_columns WHERE constraint_name = (
      SELECT constraint_name FROM all_constraints 
      WHERE UPPER(table_name) = UPPER('tableName') AND CONSTRAINT_TYPE = 'P'
    );
    

How to search text using php if ($text contains "World")

This might be what you are looking for:

<?php

$text = 'This is a Simple text.';

// this echoes "is is a Simple text." because 'i' is matched first
echo strpbrk($text, 'mi');

// this echoes "Simple text." because chars are case sensitive
echo strpbrk($text, 'S');
?>

Is it?

Or maybe this:

<?php
$mystring = 'abc';
$findme   = 'a';
$pos = strpos($mystring, $findme);

// Note our use of ===.  Simply == would not work as expected
// because the position of 'a' was the 0th (first) character.
if ($pos === false) {
    echo "The string '$findme' was not found in the string '$mystring'";
} else {
    echo "The string '$findme' was found in the string '$mystring'";
    echo " and exists at position $pos";
}
?>

Or even this

<?php
$email  = '[email protected]';
$domain = strstr($email, '@');
echo $domain; // prints @example.com

$user = strstr($email, '@', true); // As of PHP 5.3.0
echo $user; // prints name
?>

You can read all about them in the documentation here:

http://php.net/manual/en/book.strings.php

How can I clear the input text after clicking

Update: I took your saying "click" literally, which was a bit dumb of me. You can substitute focus for click in all of the below if you also want the action to happen when the user tabs to the input, which seems likely.

Update 2: My guess is that you're looking to do placeholders; see note and example at the end.


Original answer:

You can do this:

$("selector_for_the_input").click(function() {
    this.value = '';
});

...but that will clear the text regardless of what it is. If you only want to clear it if it's a specific value:

$("selector_for_the_input").click(function() {
    if (this.value === "TEXT") {
        this.value = '';
    }
});

So for example, if the input has an id, you could do:

$("#theId").click(function() {
    if (this.value === "TEXT") {
        this.value = '';
    }
});

Or if it's in a form with an id (say, "myForm") and you want to do this for every form field:

$("#myForm input").click(function() {
    if (this.value === "TEXT") {
        this.value = '';
    }
});

You may also be able to do it with delegation:

$("#myForm").delegate("input", "click", function() {
    if (this.value === "TEXT") {
        this.value = '';
    }
});

That uses delegate to hook up a handler on the form but apply it to the inputs on the form, rather than hooking up a handler to each individual input.


If you're trying to do placeholders, there's more to it than that and you may want to find a good plug-in to do it. But here's the basics:

HTML:

<form id='theForm'>
  <label>Field 1:
    <input type='text' value='provide a value for field 1'>
  </label>
  <br><label>Field 2:
    <input type='text' value='provide a value for field 2'>
  </label>
  <br><label>Field 3:
    <input type='text' value='provide a value for field 3'>
  </label>
</form>

JavaScript using jQuery:

jQuery(function($) {

  // Save the initial values of the inputs as placeholder text
  $('#theForm input').attr("data-placeholdertext", function() {
    return this.value;
  });

  // Hook up a handler to delete the placeholder text on focus,
  // and put it back on blur
  $('#theForm')
    .delegate('input', 'focus', function() {
      if (this.value === $(this).attr("data-placeholdertext")) {
        this.value = '';
      }
    })
    .delegate('input', 'blur', function() {
      if (this.value.length == 0) {
        this.value = $(this).attr("data-placeholdertext");
      }
    });

});

Live copy

Of course, you can also use the new placeholder attribute from HTML5 and only do the above if your code is running on a browser that doesn't support it, in which case you want to invert the logic I used above:

HTML:

<form id='theForm'>
  <label>Field 1:
    <input type='text' placeholder='provide a value for field 1'>
  </label>
  <br><label>Field 2:
    <input type='text' placeholder='provide a value for field 2'>
  </label>
  <br><label>Field 3:
    <input type='text' placeholder='provide a value for field 3'>
  </label>
</form>

JavaScript with jQuery:

jQuery(function($) {

  // Is placeholder supported?
  if ('placeholder' in document.createElement('input')) {
    // Yes, no need for us to do it
    display("This browser supports automatic placeholders");
  }
  else {
    // No, do it manually
    display("Manual placeholders");

    // Set the initial values of the inputs as placeholder text
    $('#theForm input').val(function() {
      if (this.value.length == 0) {
        return $(this).attr('placeholder');
      }
    });

    // Hook up a handler to delete the placeholder text on focus,
    // and put it back on blur
    $('#theForm')
      .delegate('input', 'focus', function() {
        if (this.value === $(this).attr("placeholder")) {
          this.value = '';
        }
      })
      .delegate('input', 'blur', function() {
        if (this.value.length == 0) {
          this.value = $(this).attr("placeholder");
        }
      });
  }

  function display(msg) {
    $("<p>").html(msg).appendTo(document.body);
  }

});

Live copy

(Kudos to diveintohtml5.ep.io for the placholder feature-detection code.)

Limit the height of a responsive image with css

The trick is to add both max-height: 100%; and max-width: 100%; to .container img. Example CSS:

.container {
  width: 300px;
  border: dashed blue 1px;
}

.container img {
  max-height: 100%;
  max-width: 100%;
}

In this way, you can vary the specified width of .container in whatever way you want (200px or 10% for example), and the image will be no larger than its natural dimensions. (You could specify pixels instead of 100% if you didn't want to rely on the natural size of the image.)

Here's the whole fiddle: http://jsfiddle.net/KatieK/Su28P/1/

should use size_t or ssize_t

ssize_t is not included in the standard and isn't portable. size_t should be used when handling the size of objects (there's ptrdiff_t too, for pointer differences).

How does a hash table work?

Here's an explanation in layman's terms.

Let's assume you want to fill up a library with books and not just stuff them in there, but you want to be able to easily find them again when you need them.

So, you decide that if the person that wants to read a book knows the title of the book and the exact title to boot, then that's all it should take. With the title, the person, with the aid of the librarian, should be able to find the book easily and quickly.

So, how can you do that? Well, obviously you can keep some kind of list of where you put each book, but then you have the same problem as searching the library, you need to search the list. Granted, the list would be smaller and easier to search, but still you don't want to search sequentially from one end of the library (or list) to the other.

You want something that, with the title of the book, can give you the right spot at once, so all you have to do is just stroll over to the right shelf, and pick up the book.

But how can that be done? Well, with a bit of forethought when you fill up the library and a lot of work when you fill up the library.

Instead of just starting to fill up the library from one end to the other, you devise a clever little method. You take the title of the book, run it through a small computer program, which spits out a shelf number and a slot number on that shelf. This is where you place the book.

The beauty of this program is that later on, when a person comes back in to read the book, you feed the title through the program once more, and get back the same shelf number and slot number that you were originally given, and this is where the book is located.

The program, as others have already mentioned, is called a hash algorithm or hash computation and usually works by taking the data fed into it (the title of the book in this case) and calculates a number from it.

For simplicity, let's say that it just converts each letter and symbol into a number and sums them all up. In reality, it's a lot more complicated than that, but let's leave it at that for now.

The beauty of such an algorithm is that if you feed the same input into it again and again, it will keep spitting out the same number each time.

Ok, so that's basically how a hash table works.

Technical stuff follows.

First, there's the size of the number. Usually, the output of such a hash algorithm is inside a range of some large number, typically much larger than the space you have in your table. For instance, let's say that we have room for exactly one million books in the library. The output of the hash calculation could be in the range of 0 to one billion which is a lot higher.

So, what do we do? We use something called modulus calculation, which basically says that if you counted to the number you wanted (i.e. the one billion number) but wanted to stay inside a much smaller range, each time you hit the limit of that smaller range you started back at 0, but you have to keep track of how far in the big sequence you've come.

Say that the output of the hash algorithm is in the range of 0 to 20 and you get the value 17 from a particular title. If the size of the library is only 7 books, you count 1, 2, 3, 4, 5, 6, and when you get to 7, you start back at 0. Since we need to count 17 times, we have 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, and the final number is 3.

Of course modulus calculation isn't done like that, it's done with division and a remainder. The remainder of dividing 17 by 7 is 3 (7 goes 2 times into 17 at 14 and the difference between 17 and 14 is 3).

Thus, you put the book in slot number 3.

This leads to the next problem. Collisions. Since the algorithm has no way to space out the books so that they fill the library exactly (or the hash table if you will), it will invariably end up calculating a number that has been used before. In the library sense, when you get to the shelf and the slot number you wish to put a book in, there's already a book there.

Various collision handling methods exist, including running the data into yet another calculation to get another spot in the table (double hashing), or simply to find a space close to the one you were given (i.e. right next to the previous book assuming the slot was available also known as linear probing). This would mean that you have some digging to do when you try to find the book later, but it's still better than simply starting at one end of the library.

Finally, at some point, you might want to put more books into the library than the library allows. In other words, you need to build a bigger library. Since the exact spot in the library was calculated using the exact and current size of the library, it goes to follow that if you resize the library you might end up having to find new spots for all the books since the calculation done to find their spots has changed.

I hope this explanation was a bit more down to earth than buckets and functions :)

File path to resource in our war/WEB-INF folder?

I know this is late, but this is how I normally do it,

ClassLoader classLoader = Thread.currentThread().getContextClassLoader();           
InputStream stream = classLoader.getResourceAsStream("../test/foo.txt");

adding 30 minutes to datetime php/mysql

If you are using MySQL you can do it like this:

SELECT '2008-12-31 23:59:59' + INTERVAL 30 MINUTE;


For a pure PHP solution use strtotime

strtotime('+ 30 minute',$yourdate);

Java 8 - Best way to transform a list: map or foreach?

One of the main benefits of using streams is that it gives the ability to process data in a declarative way, that is, using a functional style of programming. It also gives multi-threading capability for free meaning there is no need to write any extra multi-threaded code to make your stream concurrent.

Assuming the reason you are exploring this style of programming is that you want to exploit these benefits then your first code sample is potentially not functional since the foreach method is classed as being terminal (meaning that it can produce side-effects).

The second way is preferred from functional programming point of view since the map function can accept stateless lambda functions. More explicitly, the lambda passed to the map function should be

  1. Non-interfering, meaning that the function should not alter the source of the stream if it is non-concurrent (e.g. ArrayList).
  2. Stateless to avoid unexpected results when doing parallel processing (caused by thread scheduling differences).

Another benefit with the second approach is if the stream is parallel and the collector is concurrent and unordered then these characteristics can provide useful hints to the reduction operation to do the collecting concurrently.

Unable to establish SSL connection upon wget on Ubuntu 14.04 LTS

If you trust the host, either add the valid certificate, specify --no-check-certificate or add:

check_certificate = off

into your ~/.wgetrc.

In some rare cases, your system time could be out-of-sync therefore invalidating the certificates.

Good PHP ORM Library?

Look into Doctrine.

Doctrine 1.2 implements Active Record. Doctrine 2+ is a DataMapper ORM.

Also, check out Xyster. It's based on the Data Mapper pattern.

Also, take a look at DataMapper vs. Active Record.

How to select the first row of each group?

The solution below does only one groupBy and extract the rows of your dataframe that contain the maxValue in one shot. No need for further Joins, or Windows.

import org.apache.spark.sql.Row
import org.apache.spark.sql.catalyst.encoders.RowEncoder
import org.apache.spark.sql.DataFrame

//df is the dataframe with Day, Category, TotalValue

implicit val dfEnc = RowEncoder(df.schema)

val res: DataFrame = df.groupByKey{(r) => r.getInt(0)}.mapGroups[Row]{(day: Int, rows: Iterator[Row]) => i.maxBy{(r) => r.getDouble(2)}}

Difference between drop table and truncate table?

DROP TABLE deletes the table.

TRUNCATE TABLE empties it, but leaves its structure for future data.

How to add a file to the last commit in git?

If you didn't push the update in remote then the simple solution is remove last local commit using following command: git reset HEAD^. Then add all files and commit again.

C# string does not contain possible?

You should put all your words into some kind of Collection or List and then call it like this:

var searchFor = new List<string>();
searchFor.Add("pineapple");
searchFor.Add("mango");

bool containsAnySearchString = searchFor.Any(word => compareString.Contains(word));

If you need to make a case or culture independent search you should call it like this:

bool containsAnySearchString = 
   searchFor.Any(word => compareString.IndexOf
     (word, StringComparison.InvariantCultureIgnoreCase >= 0);

SQLite "INSERT OR REPLACE INTO" vs. "UPDATE ... WHERE"

UPDATE will not do anything if the row does not exist.

Where as the INSERT OR REPLACE would insert if the row does not exist, or replace the values if it does.

How can I use a local image as the base image with a dockerfile?

Remember to put not only the tag but also the repository in which that tag is, this way:

docker images
REPOSITORY                                TAG                       IMAGE ID            CREATED             SIZE
elixir                                    1.7-centos7_3             e15e6bf57262        20 hours ago        925MB

You should reference it this way:

elixir:1.7-centos7_3

How to hide/show more text within a certain length (like youtube)

Updated @Hussein solution with preview height that will adapt to the paragraph number of lines.

So with this bit of code : - You can choose the number of lines you want to show in preview, it will works for all screen sizes, even if font-size is responsive. - There is no need to add classes or back-end editing to separate preview from whole content.

http://jsfiddle.net/7Vv8u/5816/

var h = $('div')[0].scrollHeight;

divLineHeight = parseInt($('div').css('line-height'));
divPaddingTop = parseInt($('div').css('padding-top'));
lineToShow = 2;
divPreviewHeight = divLineHeight*lineToShow - divPaddingTop;
$('div').css('height', divPreviewHeight );

$('#more').click(function(e) {
  e.stopPropagation();
  $('div').animate({
    'height': h
  })
});

$(document).click(function() {
  $('div').animate({
    'height': divPreviewHeight
  })
})

What does $_ mean in PowerShell?

$_ is an variable which iterates over each object/element passed from the previous | (pipe).

Key existence check in HashMap

You can also use the computeIfAbsent() method in the HashMap class.

In the following example, map stores a list of transactions (integers) that are applied to the key (the name of the bank account). To add 2 transactions of 100 and 200 to checking_account you can write:

HashMap<String, ArrayList<Integer>> map = new HashMap<>();
map.computeIfAbsent("checking_account", key -> new ArrayList<>())
   .add(100)
   .add(200);

This way you don't have to check to see if the key checking_account exists or not.

  • If it does not exist, one will be created and returned by the lambda expression.
  • If it exists, then the value for the key will be returned by computeIfAbsent().

Really elegant!

import .css file into .less file

From the LESS website:

If you want to import a CSS file, and don’t want LESS to process it, just use the .css extension:

@import "lib.css"; The directive will just be left as is, and end up in the CSS output.

As jitbit points out in the comments below, this is really only useful for development purposes, as you wouldn't want to have unnecessary @imports consuming precious bandwidth.

Reinitialize Slick js after successful ajax call

The best way would be to use the unslick setting or function(depending on your version of slick) as stated in the other answers but that did not work for me. I'm getting some errors from slick that seem to be related to this.

What did work for now, however, is removing the slick-initialized and slick-slider classes from the container before reinitializing slick, like so:

function slickCarousel() {
    $('.skills_section').removeClass("slick-initialized slick-slider");
    $('.skills_section').slick({
        infinite: true,
        slidesToShow: 3,
        slidesToScroll: 1
    });
}

Removing the classes doesn't seem to initiate the destroy event(not tested but makes sense) but does cause the later slick() call to behave properly so as long as you don't have any triggers on destroy, you should be good.

How do you sort an array on multiple columns?

String Appending Method

You can sort by multiple values simply by appending the values into a string and comparing the strings. It is helpful to add a split key character to prevent runoff from one key to the next.

Example

_x000D_
_x000D_
const arr = [ 
    { a: 1, b: 'a', c: 3 },
    { a: 2, b: 'a', c: 5 },
    { a: 1, b: 'b', c: 4 },
    { a: 2, b: 'a', c: 4 }
]


function sortBy (arr, keys, splitKeyChar='~') {
    return arr.sort((i1,i2) => {
        const sortStr1 = keys.reduce((str, key) => str + splitKeyChar+i1[key], '')
        const sortStr2 = keys.reduce((str, key) => str + splitKeyChar+i2[key], '')
        return sortStr1.localeCompare(sortStr2)
    })
}

console.log(sortBy(arr, ['a', 'b', 'c']))
_x000D_
_x000D_
_x000D_

Recursion Method

You can also use Recursion to do this. It is a bit more complex than the String Appending Method but it allows you to do ASC and DESC on the key level. I'm commenting on each section as it is a bit more complex.

There are a few commented out tests to show and verify the sorting works with a mixture of order and default order.

Example

const arr = [ 
    { a: 1, b: 'a', c: 3 },
    { a: 2, b: 'a', c: 5 },
    { a: 1, b: 'b', c: 4 },
    { a: 2, b: 'a', c: 4 }
]


function sortBy (arr, keys) {
    return arr.sort(function sort (i1,i2, sKeys=keys) {
        // Get order and key based on structure
        const compareKey = (sKeys[0].key) ? sKeys[0].key : sKeys[0];
        const order = sKeys[0].order || 'ASC'; // ASC || DESC
        // Calculate compare value and modify based on order
        let compareValue = i1[compareKey].toString().localeCompare(i2[compareKey].toString())
        compareValue = (order.toUpperCase() === 'DESC') ? compareValue * -1 : compareValue
        // See if the next key needs to be considered 
        const checkNextKey = compareValue === 0 && sKeys.length !== 1
        // Return compare value
        return (checkNextKey) ? sort(i1, i2, sKeys.slice(1)): compareValue;
    })
}

// console.log(sortBy(arr, ['a', 'b', 'c']))
console.log(sortBy(arr, [{key:'a',order:'desc'}, 'b', 'c']))
// console.log(sortBy(arr, ['a', 'b', {key:'c',order:'desc'}]))
// console.log(sortBy(arr, ['a', {key:'b',order:'desc'}, 'c']))
// console.log(sortBy(arr, [{key:'a',order:'asc'}, {key:'b',order:'desc'}, {key:'c',order:'desc'}]))

date() method, "A non well formed numeric value encountered" does not want to format a date passed in $_POST

From the documentation for strtotime():

Dates in the m/d/y or d-m-y formats are disambiguated by looking at the separator between the various components: if the separator is a slash (/), then the American m/d/y is assumed; whereas if the separator is a dash (-) or a dot (.), then the European d-m-y format is assumed.

In your date string, you have 12-16-2013. 16 isn't a valid month, and hence strtotime() returns false.

Since you can't use DateTime class, you could manually replace the - with / using str_replace() to convert the date string into a format that strtotime() understands:

$date = '2-16-2013';
echo date('Y-m-d', strtotime(str_replace('-','/', $date))); // => 2013-02-16

what does the __file__ variable mean/do?

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

Taking your examples one at a time:

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

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

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

You can see the various values returned from these here:

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

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


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

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

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

Taken from the docs:

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

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

To see this in action try:

# file: test.py

print globals()
print __file__

And run:

python test.py

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

How to solve npm install throwing fsevents warning on non-MAC OS?

I also had the same issue though am using MacOS. The issue is kind of bug. I solved this issue by repeatedly running the commands,

sudo npm cache clean --force 
sudo npm uninstall 
sudo npm install

One time it did not work but when I repeatedly cleaned the cache and after uninstalling npm, reinstalling npm, the error went off. I am using Angular 8 and this issue is common

Compare every item to every other item in ArrayList

This code helped me get this behaviour: With a list a,b,c, I should get compared ab, ac and bc, but any other pair would be excess / not needed.

import java.util.*;
import static java.lang.System.out;

// rl = rawList; lr = listReversed
ArrayList<String> rl = new ArrayList<String>();
ArrayList<String> lr = new ArrayList<String>();
rl.add("a");
rl.add("b");
rl.add("c");
rl.add("d");
rl.add("e");
rl.add("f");

lr.addAll(rl);
Collections.reverse(lr);

for (String itemA : rl) {
    lr.remove(lr.size()-1);
        for (String itemZ : lr) {
        System.out.println(itemA + itemZ);
    }
}

The loop goes as like in this picture: Triangular comparison visual example

or as this:

   |   f    e    d    c    b   a
   ------------------------------
a  |  af   ae   ad   ac   ab   ·
b  |  bf   be   bd   bc   ·   
c  |  cf   ce   cd   ·      
d  |  df   de   ·         
e  |  ef   ·            
f  |  ·               

total comparisons is a triangular number (n * n-1)/2

Is there any native DLL export functions viewer?

If you don't have the source code and API documentation, the machine code is all there is, you need to disassemble the dll library using something like IDA Pro , another option is use the trial version of PE Explorer.

PE Explorer provides a Disassembler. There is only one way to figure out the parameters: run the disassembler and read the disassembly output. Unfortunately, this task of reverse engineering the interface cannot be automated.

PE Explorer comes bundled with descriptions for 39 various libraries, including the core Windows® operating system libraries (eg. KERNEL32, GDI32, USER32, SHELL32, WSOCK32), key graphics libraries (DDRAW, OPENGL32) and more.

alt text
(source: heaventools.com)

Chrome - ERR_CACHE_MISS

If you are using WebView in Android developing the problem is that you didn't add uses permission

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

How can I convert a datetime object to milliseconds since epoch (unix time) in Python?

You can use Delorean to travel in space and time!

import datetime
import delorean
dt = datetime.datetime.utcnow()
delorean.Delorean(dt, timezone="UTC").epoch

http://delorean.readthedocs.org/en/latest/quickstart.html  

How to change Toolbar Navigation and Overflow Menu icons (appcompat v7)?

There is a simple, easy and better approach, if we need to change only the color of hamburger/back icon.

It is better as it changes color only of desired icon, whereas colorControlNormal and android:textColorSecondary might affect other childviews of toolbar as well.

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <item name="drawerArrowStyle">@style/DrawerArrowStyle</item>
</style>

<style name="DrawerArrowStyle" parent="Widget.AppCompat.DrawerArrowToggle">
    <item name="spinBars">true</item>
    <item name="color">@android:color/white</item>
</style>

Copy files from one directory into an existing directory

Depending on some details you might need to do something like this:

r=$(pwd)
case "$TARG" in
    /*) p=$r;;
    *) p="";;
    esac
cd "$SRC" && cp -r . "$p/$TARG"
cd "$r"

... this basically changes to the SRC directory and copies it to the target, then returns back to whence ever you started.

The extra fussing is to handle relative or absolute targets.

(This doesn't rely on subtle semantics of the cp command itself ... about how it handles source specifications with or without a trailing / ... since I'm not sure those are stable, portable, and reliable beyond just GNU cp and I don't know if they'll continue to be so in the future).

Get the element triggering an onclick event in jquery?

It's top google stackoverflow question, but all answers are not jQuery related!

$(".someclass").click(
    function(event)
    {
        console.log(event, this);
    }
);

'event' contains 2 important values:

event.currentTarget - element to which event is triggered ('.someclass' element)

event.target - element clicked (in case when inside '.someclass' [div] are other elements and you clicked on of them)

this - is set to triggered element ('.someclass'), but it's JavaScript element, not jQuery element, so if you want to use some jQuery function on it, you must first change it to jQuery element: $(this)

When your refresh the page and reload the scripts again; this method not work. You have to use jquery "unbind" method.

Is there a way to remove unused imports and declarations from Angular 2+?

If you're a heavy visual studio user, you can simply open your preference settings and add the following to your settings.json:

...
"editor.formatOnSave": true,
"editor.codeActionsOnSave": {
  "source.organizeImports": true
}
....

Hopefully this can be helpful!

Find UNC path of a network drive?

The answer is a simple PowerShell one-liner:

Get-WmiObject Win32_NetworkConnection | ft "RemoteName","LocalName" -A

If you only want to pull the UNC for one particular drive, add a where statement:

Get-WmiObject Win32_NetworkConnection | where -Property 'LocalName' -eq 'Z:'  | ft "RemoteName","LocalName" -A

How do I handle newlines in JSON?

According to the specification, http://www.ecma-international.org/publications/files/ECMA-ST/ECMA-404.pdf:

A string is a sequence of Unicode code points wrapped with quotation marks (U+0022). All characters may be placed within the quotation marks except for the characters that must be escaped: quotation mark (U+0022), reverse solidus (U+005C), and the control characters U+0000 to U+001F. There are two-character escape sequence representations of some characters.

So you can't pass 0x0A or 0x0C codes directly. It is forbidden! The specification suggests to use escape sequences for some well-defined codes from U+0000 to U+001F:

  • \f represents the form feed character (U+000C).
  • \n represents the line feed character (U+000A).

As most of programming languages uses \ for quoting, you should escape the escape syntax (double-escape - once for language/platform, once for JSON itself):

jsonStr = "{ \"name\": \"Multi\\nline.\" }";

Executing another application from Java

Here is an example of how to use ProcessBuilder to execute your remote application. Since you do not care about input/output and/or errors, you can do as follows:

List<String> args = new ArrayList<String>();
args.add ("script.bat"); // command name
args.add ("-option"); // optional args added as separate list items
ProcessBuilder pb = new ProcessBuilder (args);
Process p = pb.start();
p.waitFor();

the waitFor() method will wait until the process had ended before continuing. This method returns the error code of the process but, since you don't care about it, I didn't put it in the example.

python plot normal distribution

Use seaborn instead i am using distplot of seaborn with mean=5 std=3 of 1000 values

value = np.random.normal(loc=5,scale=3,size=1000)
sns.distplot(value)

You will get a normal distribution curve

Need to make a clickable <div> button

Just use an <a> by itself, set it to display: block; and set width and height. Get rid of the <span> and <div>. This is the semantic way to do it. There is no need to wrap things in <divs> (or any element) for layout. That is what CSS is for.

Demo: http://jsfiddle.net/ThinkingStiff/89Enq/

HTML:

<a id="music" href="Music.html">Music I Like</a>

CSS:

#music {
    background-color: black;
    color: white;
    display: block;
    height: 40px;
    line-height: 40px;
    text-decoration: none;
    width: 100px;
    text-align: center;
}

Output:

enter image description here

How to declare a Fixed length Array in TypeScript

The Tuple approach :

This solution provides a strict FixedLengthArray (ak.a. SealedArray) type signature based in Tuples.

Syntax example :

// Array containing 3 strings
let foo : FixedLengthArray<[string, string, string]> 

This is the safest approach, considering it prevents accessing indexes out of the boundaries.

Implementation :

type ArrayLengthMutationKeys = 'splice' | 'push' | 'pop' | 'shift' | 'unshift' | number
type ArrayItems<T extends Array<any>> = T extends Array<infer TItems> ? TItems : never
type FixedLengthArray<T extends any[]> =
  Pick<T, Exclude<keyof T, ArrayLengthMutationKeys>>
  & { [Symbol.iterator]: () => IterableIterator< ArrayItems<T> > }

Tests :

var myFixedLengthArray: FixedLengthArray< [string, string, string]>

// Array declaration tests
myFixedLengthArray = [ 'a', 'b', 'c' ]  // ? OK
myFixedLengthArray = [ 'a', 'b', 123 ]  // ? TYPE ERROR
myFixedLengthArray = [ 'a' ]            // ? LENGTH ERROR
myFixedLengthArray = [ 'a', 'b' ]       // ? LENGTH ERROR

// Index assignment tests 
myFixedLengthArray[1] = 'foo'           // ? OK
myFixedLengthArray[1000] = 'foo'        // ? INVALID INDEX ERROR

// Methods that mutate array length
myFixedLengthArray.push('foo')          // ? MISSING METHOD ERROR
myFixedLengthArray.pop()                // ? MISSING METHOD ERROR

// Direct length manipulation
myFixedLengthArray.length = 123         // ? READ-ONLY ERROR

// Destructuring
var [ a ] = myFixedLengthArray          // ? OK
var [ a, b ] = myFixedLengthArray       // ? OK
var [ a, b, c ] = myFixedLengthArray    // ? OK
var [ a, b, c, d ] = myFixedLengthArray // ? INVALID INDEX ERROR

(*) This solution requires the noImplicitAny typescript configuration directive to be enabled in order to work (commonly recommended practice)


The Array(ish) approach :

This solution behaves as an augmentation of the Array type, accepting an additional second parameter(Array length). Is not as strict and safe as the Tuple based solution.

Syntax example :

let foo: FixedLengthArray<string, 3> 

Keep in mind that this approach will not prevent you from accessing an index out of the declared boundaries and set a value on it.

Implementation :

type ArrayLengthMutationKeys = 'splice' | 'push' | 'pop' | 'shift' |  'unshift'
type FixedLengthArray<T, L extends number, TObj = [T, ...Array<T>]> =
  Pick<TObj, Exclude<keyof TObj, ArrayLengthMutationKeys>>
  & {
    readonly length: L 
    [ I : number ] : T
    [Symbol.iterator]: () => IterableIterator<T>   
  }

Tests :

var myFixedLengthArray: FixedLengthArray<string,3>

// Array declaration tests
myFixedLengthArray = [ 'a', 'b', 'c' ]  // ? OK
myFixedLengthArray = [ 'a', 'b', 123 ]  // ? TYPE ERROR
myFixedLengthArray = [ 'a' ]            // ? LENGTH ERROR
myFixedLengthArray = [ 'a', 'b' ]       // ? LENGTH ERROR

// Index assignment tests 
myFixedLengthArray[1] = 'foo'           // ? OK
myFixedLengthArray[1000] = 'foo'        // ? SHOULD FAIL

// Methods that mutate array length
myFixedLengthArray.push('foo')          // ? MISSING METHOD ERROR
myFixedLengthArray.pop()                // ? MISSING METHOD ERROR

// Direct length manipulation
myFixedLengthArray.length = 123         // ? READ-ONLY ERROR

// Destructuring
var [ a ] = myFixedLengthArray          // ? OK
var [ a, b ] = myFixedLengthArray       // ? OK
var [ a, b, c ] = myFixedLengthArray    // ? OK
var [ a, b, c, d ] = myFixedLengthArray // ? SHOULD FAIL

Default values and initialization in Java

I wrote following function to return a default representation 0 or false of a primitive or Number:

/**
 * Retrieves the default value 0 / false for any primitive representative or
 * {@link Number} type.
 *
 * @param type
 *
 * @return
 */
@SuppressWarnings("unchecked")
public static <T> T getDefault(final Class<T> type)
{
    if (type.equals(Long.class) || type.equals(Long.TYPE))
        return (T) new Long(0);
    else if (type.equals(Integer.class) || type.equals(Integer.TYPE))
        return (T) new Integer(0);
    else if (type.equals(Double.class) || type.equals(Double.TYPE))
        return (T) new Double(0);
    else if (type.equals(Float.class) || type.equals(Float.TYPE))
        return (T) new Float(0);
    else if (type.equals(Short.class) || type.equals(Short.TYPE))
        return (T) new Short((short) 0);
    else if (type.equals(Byte.class) || type.equals(Byte.TYPE))
        return (T) new Byte((byte) 0);
    else if (type.equals(Character.class) || type.equals(Character.TYPE))
        return (T) new Character((char) 0);
    else if (type.equals(Boolean.class) || type.equals(Boolean.TYPE))
        return (T) new Boolean(false);
    else if (type.equals(BigDecimal.class))
        return (T) BigDecimal.ZERO;
    else if (type.equals(BigInteger.class))
        return (T) BigInteger.ZERO;
    else if (type.equals(AtomicInteger.class))
        return (T) new AtomicInteger();
    else if (type.equals(AtomicLong.class))
        return (T) new AtomicLong();
    else if (type.equals(DoubleAdder.class))
        return (T) new DoubleAdder();
    else
        return null;
}

I use it in hibernate ORM projection queries when the underlying SQL query returns null instead of 0.

/**
 * Retrieves the unique result or zero, <code>false</code> if it is
 * <code>null</code> and represents a number
 *
 * @param criteria
 *
 * @return zero if result is <code>null</code>
 */
public static <T> T getUniqueResultDefault(final Class<T> type, final Criteria criteria)
{
    final T result = (T) criteria.uniqueResult();

    if (result != null)
        return result;
    else
        return Utils.getDefault(type);
}

One of the many unnecessary complex things about Java making it unintuitive to use. Why instance variables are initialized with default 0 but local are not is not logical. Similar why enums dont have built in flag support and many more options. Java lambda is a nightmare compared to C# and not allowing class extension methods is also a big problem.

Java ecosystem comes up with excuses why its not possible but me as the user / developer i dont care about their excuses. I want easy approach and if they dont fix those things they will loose big in the future since C# and other languages are not waiting to make life of developers more simple. Its just sad to see the decline in the last 10 years since i work daily with Java.

Spring boot: Unable to start embedded Tomcat servlet container

Simple way to handle this is to include this in your application.properties or .yml file: server.port=0 for application.properties and server.port: 0 for application.yml files. Of course need to be aware these may change depending on the springboot version you are using. These will allow your machine to dynamically allocate any free port available for use. To statically assign a port change the above to server.port = someportnumber. If running unix based OS you may want to check for zombie activities on the port in question and if possible kill it using fuser -k {theport}/tcp. Your .yml or .properties should look like this. server: port: 8089 servlet: context-path: /somecontextpath

How to see query history in SQL Server Management Studio

you can use "Automatically generate script on every save", if you are using management studio. This is not certainly logging. Check if useful for you.. ;)

Java ResultSet how to check if there are any results

You would usually do something like this:

while ( resultSet.next() ) { 
   // Read the next item
   resultSet.getString("columnName");
}

If you want to report an empty set, add a variable counting the items read. If you only need to read a single item, then your code is adequate.

Passing variables to the next middleware using next() in Express.js

The trick is pretty simple... The request cycle is still pretty much alive. You can just add a new variable that will create a temporary, calling

app.get('some/url/endpoint', middleware1, middleware2);

Since you can handle your request in the first middleware

(req, res, next) => {
    var yourvalue = anyvalue
}

In middleware 1 you handle your logic and store your value like below:

req.anyvariable = yourvalue

In middleware 2 you can catch this value from middleware 1 doing the following:

(req, res, next) => {
    var storedvalue = req.yourvalue
}

How to count days between two dates in PHP?

Here is the raw way to do it

$startTimeStamp = strtotime("2011/07/01");
$endTimeStamp = strtotime("2011/07/17");

$timeDiff = abs($endTimeStamp - $startTimeStamp);

$numberDays = $timeDiff/86400;  // 86400 seconds in one day

// and you might want to convert to integer
$numberDays = intval($numberDays);

Representing Directory & File Structure in Markdown Syntax

You can use tree to generate something very similar to your example. Once you have the output, you can wrap it in a <pre> tag to preserve the plain text formatting.

How to display alt text for an image in chrome

I use this, it works with php...

<span><?php
if (file_exists("image/".$data['img_name'])) {
  ?>
  <img src="image/<?php echo $data['img_name']; ?>" width="100" height="100">
  <?php
}else{
  echo "Image Not Found";
}>?
</span>

Essentially what the code is doing, is checking for the File. The $data variable will be used with our array then actually make the desired change. If it isn't found, it will throw an Exception.

How to make a promise from setTimeout

Update (2017)

Here in 2017, Promises are built into JavaScript, they were added by the ES2015 spec (polyfills are available for outdated environments like IE8-IE11). The syntax they went with uses a callback you pass into the Promise constructor (the Promise executor) which receives the functions for resolving/rejecting the promise as arguments.

First, since async now has a meaning in JavaScript (even though it's only a keyword in certain contexts), I'm going to use later as the name of the function to avoid confusion.

Basic Delay

Using native promises (or a faithful polyfill) it would look like this:

function later(delay) {
    return new Promise(function(resolve) {
        setTimeout(resolve, delay);
    });
}

Note that that assumes a version of setTimeout that's compliant with the definition for browsers where setTimeout doesn't pass any arguments to the callback unless you give them after the interval (this may not be true in non-browser environments, and didn't used to be true on Firefox, but is now; it's true on Chrome and even back on IE8).

Basic Delay with Value

If you want your function to optionally pass a resolution value, on any vaguely-modern browser that allows you to give extra arguments to setTimeout after the delay and then passes those to the callback when called, you can do this (current Firefox and Chrome; IE11+, presumably Edge; not IE8 or IE9, no idea about IE10):

function later(delay, value) {
    return new Promise(function(resolve) {
        setTimeout(resolve, delay, value); // Note the order, `delay` before `value`
        /* Or for outdated browsers that don't support doing that:
        setTimeout(function() {
            resolve(value);
        }, delay);
        Or alternately:
        setTimeout(resolve.bind(null, value), delay);
        */
    });
}

If you're using ES2015+ arrow functions, that can be more concise:

function later(delay, value) {
    return new Promise(resolve => setTimeout(resolve, delay, value));
}

or even

const later = (delay, value) =>
    new Promise(resolve => setTimeout(resolve, delay, value));

Cancellable Delay with Value

If you want to make it possible to cancel the timeout, you can't just return a promise from later, because promises can't be cancelled.

But we can easily return an object with a cancel method and an accessor for the promise, and reject the promise on cancel:

const later = (delay, value) => {
    let timer = 0;
    let reject = null;
    const promise = new Promise((resolve, _reject) => {
        reject = _reject;
        timer = setTimeout(resolve, delay, value);
    });
    return {
        get promise() { return promise; },
        cancel() {
            if (timer) {
                clearTimeout(timer);
                timer = 0;
                reject();
                reject = null;
            }
        }
    };
};

Live Example:

_x000D_
_x000D_
const later = (delay, value) => {_x000D_
    let timer = 0;_x000D_
    let reject = null;_x000D_
    const promise = new Promise((resolve, _reject) => {_x000D_
        reject = _reject;_x000D_
        timer = setTimeout(resolve, delay, value);_x000D_
    });_x000D_
    return {_x000D_
        get promise() { return promise; },_x000D_
        cancel() {_x000D_
            if (timer) {_x000D_
                clearTimeout(timer);_x000D_
                timer = 0;_x000D_
                reject();_x000D_
                reject = null;_x000D_
            }_x000D_
        }_x000D_
    };_x000D_
};_x000D_
_x000D_
const l1 = later(100, "l1");_x000D_
l1.promise_x000D_
  .then(msg => { console.log(msg); })_x000D_
  .catch(() => { console.log("l1 cancelled"); });_x000D_
_x000D_
const l2 = later(200, "l2");_x000D_
l2.promise_x000D_
  .then(msg => { console.log(msg); })_x000D_
  .catch(() => { console.log("l2 cancelled"); });_x000D_
setTimeout(() => {_x000D_
  l2.cancel();_x000D_
}, 150);
_x000D_
_x000D_
_x000D_


Original Answer from 2014

Usually you'll have a promise library (one you write yourself, or one of the several out there). That library will usually have an object that you can create and later "resolve," and that object will have a "promise" you can get from it.

Then later would tend to look something like this:

function later() {
    var p = new PromiseThingy();
    setTimeout(function() {
        p.resolve();
    }, 2000);

    return p.promise(); // Note we're not returning `p` directly
}

In a comment on the question, I asked:

Are you trying to create your own promise library?

and you said

I wasn't but I guess now that's actually what I was trying to understand. That how a library would do it

To aid that understanding, here's a very very basic example, which isn't remotely Promises-A compliant: Live Copy

<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>Very basic promises</title>
</head>
<body>
  <script>
    (function() {

      // ==== Very basic promise implementation, not remotely Promises-A compliant, just a very basic example
      var PromiseThingy = (function() {

        // Internal - trigger a callback
        function triggerCallback(callback, promise) {
          try {
            callback(promise.resolvedValue);
          }
          catch (e) {
          }
        }

        // The internal promise constructor, we don't share this
        function Promise() {
          this.callbacks = [];
        }

        // Register a 'then' callback
        Promise.prototype.then = function(callback) {
          var thispromise = this;

          if (!this.resolved) {
            // Not resolved yet, remember the callback
            this.callbacks.push(callback);
          }
          else {
            // Resolved; trigger callback right away, but always async
            setTimeout(function() {
              triggerCallback(callback, thispromise);
            }, 0);
          }
          return this;
        };

        // Our public constructor for PromiseThingys
        function PromiseThingy() {
          this.p = new Promise();
        }

        // Resolve our underlying promise
        PromiseThingy.prototype.resolve = function(value) {
          var n;

          if (!this.p.resolved) {
            this.p.resolved = true;
            this.p.resolvedValue = value;
            for (n = 0; n < this.p.callbacks.length; ++n) {
              triggerCallback(this.p.callbacks[n], this.p);
            }
          }
        };

        // Get our underlying promise
        PromiseThingy.prototype.promise = function() {
          return this.p;
        };

        // Export public
        return PromiseThingy;
      })();

      // ==== Using it

      function later() {
        var p = new PromiseThingy();
        setTimeout(function() {
          p.resolve();
        }, 2000);

        return p.promise(); // Note we're not returning `p` directly
      }

      display("Start " + Date.now());
      later().then(function() {
        display("Done1 " + Date.now());
      }).then(function() {
        display("Done2 " + Date.now());
      });

      function display(msg) {
        var p = document.createElement('p');
        p.innerHTML = String(msg);
        document.body.appendChild(p);
      }
    })();
  </script>
</body>
</html>

git checkout master error: the following untracked working tree files would be overwritten by checkout

With Git 2.23 (August 2019), that would be, using git switch -f:

git switch -f master

That avoids the confusion with git checkout (which deals with files or branches).

And that will proceeds, even if the index or the working tree differs from HEAD.
Both the index and working tree are restored to match the switching target.
If --recurse-submodules is specified, submodule content is also restored to match the switching target.
This is used to throw away local changes.

What do Push and Pop mean for Stacks?

Ok. As the other answerers explained, a stack is a last-in, first-out data structure. You add an element to the top of the stack with a Push operation. You take an element off the top with a Pop operation. The elements are removed in reverse order to the order they were put inserted (hence Last In, First Out). For example, if you push the elments 1,2,3 in that order, the number 3 will be at the top of the stack. A Pop operation will remove it (it was the last in) and leave 2 at the top of the stack.

Regarding the rest of the lecture, the lecturer tried to describe a stack-based machine that evaluates arithmetic expressions. The machine operates by continuously popping 3 elements from the top of the stack. The first two elements are operands and the third is an operator (+, -, *, /). It then applies this operator on the operands, and pushes the result onto the stack. The process continues until there is only one element on the stack, which is the value of the expression.

So, suppose we begin by pushing the values "+/*23-21*5-41" in left-to-right order onto the stack. We then pop 3 elements from the top. The last in is first out, which means the first 3 element are "1", "4", and "-" in that order. We push the number 3 (the result of 4-1) onto the stack, then pop the three topmost elements: 3, 5, *. Push the result, 15, onto the stack, and so on.

Git: which is the default configured remote for branch?

You can do it more simply, guaranteeing that your .gitconfig is left in a meaningful state:

Using Git version v1.8.0 and above

git push -u hub master when pushing, or:
git branch -u hub/master

OR

(This will set the remote for the currently checked-out branch to hub/master)
git branch --set-upstream-to hub/master

OR

(This will set the remote for the branch named branch_name to hub/master)
git branch branch_name --set-upstream-to hub/master

If you're using v1.7.x or earlier

you must use --set-upstream:
git branch --set-upstream master hub/master

How to duplicate a whole line in Vim?

If you would like to duplicate a line and paste it right away below the current like, just like in Sublime Ctrl+Shift+D, then you can add this to your .vimrc file.

nmap <S-C-d> <Esc>Yp

Or, for Insert mode:

imap <S-C-d> <Esc>Ypa