Programs & Examples On #Entropy

Entropy is a measure of the uncertainty in a random variable.

How to deal with a slow SecureRandom generator?

There is a tool (on Ubuntu at least) that will feed artificial randomness into your system. The command is simply:

rngd -r /dev/urandom

and you may need a sudo at the front. If you don't have rng-tools package, you will need to install it. I tried this, and it definitely helped me!

Source: matt vs world

Fastest way to compute entropy in Python

My favorite function for entropy is the following:

def entropy(labels):
    prob_dict = {x:labels.count(x)/len(labels) for x in labels}
    probs = np.array(list(prob_dict.values()))

    return - probs.dot(np.log2(probs))

I am still looking for a nicer way to avoid the dict -> values -> list -> np.array conversion. Will comment again if I found it.

{"<user xmlns=''> was not expected.} Deserializing Twitter XML

The error message is so vague, for me I had this code:

var streamReader = new StreamReader(response.GetResponseStream());
var xmlSerializer = new XmlSerializer(typeof(aResponse));
theResponse = (bResponse) xmlSerializer.Deserialize(streamReader);

Notice xmlSerializer is instantiated with aResponse but on deserializing I accidentally casted it to bResonse.

Creating an empty file in C#

System.IO.File.Create(@"C:\Temp.txt");

As others have pointed out, you should dispose of this object or wrap it in an empty using statement.

using (System.IO.File.Create(@"C:\Temp.txt"));

AngularJS/javascript converting a date String to date object

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

new Date(collectionDate);

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

Reset/remove CSS styles for element only

Any chance you're looking for the !important rule? It doesn't undo all declarations but it provides a way to override them.

"When an !important rule is used on a style declaration, this declaration overrides any other declaration made in the CSS, wherever it is in the declaration list. Although, !important has nothing to do with specificity."

https://developer.mozilla.org/en-US/docs/CSS/Specificity#The_!important_exception

Setting the Textbox read only property to true using JavaScript

Try This :-

set Read Only False ( Editable TextBox)

document.getElementById("txtID").readOnly=false;

set Read Only true(Not Editable )

var v1=document.getElementById("txtID");
v1.setAttribute("readOnly","true");

This can work on IE and Firefox also.

Missing artifact com.sun:tools:jar

Problem is system is not able to find the file tools.jar

So first check that the file is there in the JDK installation of the directory.

enter image description here

Make the below entry in POM.xml as rightly pointed by others

<dependency>
<groupId>com.sun</groupId>
<artifactId>tools</artifactId>
<version>1.6</version>
<scope>system</scope>
<systemPath>C:\Program Files\Java\jdk1.8.0_241\lib\tools.jar</systemPath>
</dependency> 

then Follow the below steps also to remove the problem

1) Right Click on your project

2) Click on Build path

As per the below image, select the workspace default JRE and click on finish.

enter image description here

ListView inside ScrollView is not scrolling on Android

Use this method and your listview become scrollable inside scrollview:-

   ListView lstNewsOffer.setAdapter(new ViewOfferAdapter(
                            ViewNewsDetail.this, viewOfferList));
                    getListViewSize(lstNewsOffer);

void getListViewSize(ListView myListView) {
    ListAdapter myListAdapter = myListView.getAdapter();
    if (myListAdapter == null) {
        // do nothing return null
        return;
    }
    // set listAdapter in loop for getting final size
    int totalHeight = 0;
    for (int size = 0; size < myListAdapter.getCount(); size++) {
        View listItem = myListAdapter.getView(size, null, myListView);
        listItem.measure(0, 0);
        totalHeight += listItem.getMeasuredHeight();
    }
    // setting listview item in adapter
    ViewGroup.LayoutParams params = myListView.getLayoutParams();
    params.height = totalHeight
            + (myListView.getDividerHeight() * (myListAdapter.getCount() - 1));
    myListView.setLayoutParams(params);
    // print height of adapter on log
    Log.i("height of listItem:", String.valueOf(totalHeight));
}

What is a callback in java

A callback is commonly used in asynchronous programming, so you could create a method which handles the response from a web service. When you call the web service, you could pass the method to it so that when the web service responds, it call's the method you told it ... it "calls back".

In Java this can commonly be done through implementing an interface and passing an object (or an anonymous inner class) that implements it. You find this often with transactions and threading - such as the Futures API.

http://docs.oracle.com/javase/1.5.0/docs/api/java/util/concurrent/Future.html

How to change a package name in Eclipse?

HOW TO COPY AND PASTE ANDROID PROJECT

A. If you are using Eclipse and all you want to do is first open the project that you want to copy(DON"T FORGET TO OPEN THE PROJECT THAT YOU NEED TO COPY), then clone(copy/paste) your Android project within the explorer package window on the left side of Eclipse. Eclipse will ask you for a new project name when you paste. Give it a new project name. Since Eclipse project name and directory are independent of the application name and package, the following steps will help you on how to change package names. Note: there are two types of package names.

1.To change src package names of packages within Src folder follow the following steps: First you need to create new package: (src >>>> right click >>>> new >>>> package).

Example of creating package: com.new.name

Follow these steps to move the Java files from the old copied package in part A to your new package.

Select the Java files within that old package

Right click that java files

select "Refactor" option

select "Move" option

Select your preferred package from the list of packages in a dialogue window. Most probably you need to select the new one you just created and hit "OK"

2.To change Application package name(main package), follow the following steps:

First right click your project

Then go to "Android tools"

Then select "Rename Application package"

Enter a new name in a dialogue window , and hit OK.

Then It will show you in which part of your project the Application name will be changed.

It will show you that the Application name will be changed in manifest, and in most relevant Java files. Hit "OK"

YOU DONE in this part, but make sure you rebuild your project to take effect.

To rebuild your project, go to ""project" >>> "Clean" >>>> select a Project from a projects

list, and hit "OK". Finally, you can run your new project.

java.nio.file.Path for a classpath resource

This one works for me:

return Paths.get(ClassLoader.getSystemResource(resourceName).toURI());

How to make a new List in Java

As an option you can use double brace initialization here:

List<String> list = new ArrayList<String>(){
  {
   add("a");
   add("b");
  }
};

Visual Studio 2015 installer hangs during install?

Same thing happened to me, and I also tried to terminate secondary process from task manager. Do not do that. It is not a solution, but rather a hack which may cause issues later. In my case, I was not even able to uninstall Visual Studio. I tried both web installation and ISO, same issue.

Here is how it worked finally. I restored my Windows 7 to earliest restore point as possible, when there was nothing installed, so I was sure that there would be no conflicts between the different tools (Java, Android API, etc.)

I started the installation of Visual Studio 2015 Community Release Candidate at 10 p.m. At 7 a.m., it was working on Android API 19-21. A hour later, it was finally preparing Visual Studio.

This means that all you need to do is to actually wait 8 to 9 hours. Don't terminate the secondary installer at risk of breaking your Visual Studio; just wait.

Create a new file in git bash

Yes, it is. Just create files in the windows explorer and git automatically detects these files as currently untracked. Then add it with the command you already mentioned.

git add does not create any files. See also http://gitref.org/basic/#add

Github probably creates the file with touch and adds the file for tracking automatically. You can do this on the bash as well.

Automatically start forever (node) on system restart

  1. Install PM2 globally using NPM

    npm install pm2 -g

  2. Start your script with pm2

    pm2 start app.js

  3. generate an active startup script

    pm2 startup

    NOTE: pm2 startup is for startting the PM2 when the system reboots. PM2 once started, restarts all the processes it had been managing before the system went down.

In case you want to disable the automatic startup, simply use pm2 unstartup

If you want the startup script to be executed under another user, just use the -u <username> option and the --hp <user_home>:

How to capitalize the first letter of text in a TextView in an Android Application

for Kotlin, just call

textview.text = string.capitalize()

Can't import org.apache.http.HttpResponse in Android Studio

HttpClient was deprecated in Android 5.1 and is removed from the Android SDK in Android 6.0. While there is a workaround to continue using HttpClient in Android 6.0 with Android Studio, you really need to move to something else. That "something else" could be:

Or, depending upon the nature of your HTTP work, you might choose a library that supports higher-order operations (e.g., Retrofit for Web service APIs).

In a pinch, you could enable the legacy APIs, by having useLibrary 'org.apache.http.legacy' in your android closure in your module's build.gradle file. However, Google has been advising people for years to stop using Android's built-in HttpClient, and so at most, this should be a stop-gap move, while you work on a more permanent shift to another API.

Convert Mercurial project to Git

Another option is to create a free Kiln account -- kiln round trips between git and hg with 100% metadata retention, so you can use it for a one time convert or use it to access a repository using whichever client you prefer.

Android WebView progress bar

wait until the process is over ...

while(webview.getProgress()< 100){}
progressBar.setVisibility(View.GONE);

What is the precise meaning of "ours" and "theirs" in git?

I suspect you're confused here because it's fundamentally confusing. To make things worse, the whole ours/theirs stuff switches roles (becomes backwards) when you are doing a rebase.

Ultimately, during a git merge, the "ours" branch refers to the branch you're merging into:

git checkout merge-into-ours

and the "theirs" branch refers to the (single) branch you're merging:

git merge from-theirs

and here "ours" and "theirs" makes some sense, as even though "theirs" is probably yours anyway, "theirs" is not the one you were on when you ran git merge.

While using the actual branch name might be pretty cool, it falls apart in more complex cases. For instance, instead of the above, you might do:

git checkout ours
git merge 1234567

where you're merging by raw commit-ID. Worse, you can even do this:

git checkout 7777777    # detach HEAD
git merge 1234567       # do a test merge

in which case there are no branch names involved!

I think it's little help here, but in fact, in gitrevisions syntax, you can refer to an individual path in the index by number, during a conflicted merge

git show :1:README
git show :2:README
git show :3:README

Stage #1 is the common ancestor of the files, stage #2 is the target-branch version, and stage #3 is the version you are merging from.


The reason the "ours" and "theirs" notions get swapped around during rebase is that rebase works by doing a series of cherry-picks, into an anonymous branch (detached HEAD mode). The target branch is the anonymous branch, and the merge-from branch is your original (pre-rebase) branch: so "--ours" means the anonymous one rebase is building while "--theirs" means "our branch being rebased".


As for the gitattributes entry: it could have an effect: "ours" really means "use stage #2" internally. But as you note, it's not actually in place at the time, so it should not have an effect here ... well, not unless you copy it into the work tree before you start.

Also, by the way, this applies to all uses of ours and theirs, but some are on a whole file level (-s ours for a merge strategy; git checkout --ours during a merge conflict) and some are on a piece-by-piece basis (-X ours or -X theirs during a -s recursive merge). Which probably does not help with any of the confusion.

I've never come up with a better name for these, though. And: see VonC's answer to another question, where git mergetool introduces yet more names for these, calling them "local" and "remote"!

Unable to find the wrapper "https" - did you forget to enable it when you configured PHP?

For those using Winginx (nginx based instead of Apache based), I fixed it with these 4 steps:

  1. On the Tools menu hit the Winginx PHP5 Config (never mind the 5 in the name...):

    Winginx PHP5 Config

  2. Select the PHP version you want the php.ini to change:

    PHP version selection

  3. On the PHP Extensions tab select the php_openssl extension and hit the Save button:

    php_openssl selection

  4. restart the appropriate PHP service through the taskbar (Stop and Start):

    Restart PHP service

How to convert a single char into an int

Or you could use the "correct" method, similar to your original atoi approach, but with std::stringstream instead. That should work with chars as input as well as strings. (boost::lexical_cast is another option for a more convenient syntax)

(atoi is an old C function, and it's generally recommended to use the more flexible and typesafe C++ equivalents where possible. std::stringstream covers conversion to and from strings)

cd into directory without having permission

You've got several options:

  • Use a different user account, one with execute permissions on that directory.
  • Change the permissions on the directory to allow your user account execute permissions.
    • Either use chmod(1) to change the permissions or
    • Use the setfacl(1) command to add an access control list entry for your user account. (This also requires mounting the filesystem with the acl option; see mount(8) and fstab(5) for details on the mount parameter.)

It's impossible to suggest the correct approach without knowing more about the problem; why are the directory permissions set the way they are? Why do you need access to that directory?

The default XML namespace of the project must be the MSBuild XML namespace

if the project is not a big ,

1- change the name of folder project

2- make a new project with the same project (before renaming)

3- add existing files from the old project to the new project (totally same , same folders , same names , ...)

4- open the the new project file (as xml ) and the old project

5- copy the new project file (xml content ) and paste it in the old project file

6- delete the old project

7- rename the old folder project to old name

How do you handle a form change in jQuery?

var formStr = JSON.stringify($("#form").serializeArray());
...
function Submit(){
   var newformStr = JSON.stringify($("#form").serializeArray());
   if (formStr != newformStr){
      ...
         formChangedfunct();
      ...
   }
   else {
      ...
         formUnchangedfunct();
      ...
   }
}

psql: could not connect to server: No such file or directory (Mac OS X)

I just got the same issue as I have put my machine(ubuntu) for update and got below error:

could not connect to server: No such file or directory Is the server running locally and accepting connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?

After completing the updating process when I restart my system error gone. And its work like charm as before.. I guess this was happened as pg was updating and another process started.

Optional Parameters in Go?

I ended up using a combination of a structure of params and variadic args. This way, I didn't have to change the existing interface which was consumed by several services and my service was able to pass additional params as needed. Sample code in golang playground: https://play.golang.org/p/G668FA97Nu

Determine Pixel Length of String in Javascript/jQuery?

First replicate the location and styling of the text and then use Jquery width() function. This will make the measurements accurate. For example you have css styling with a selector of:

.style-head span
{
  //Some style set
}

You would need to do this with Jquery already included above this script:

var measuringSpan = document.createElement("span");
measuringSpan.innerText = 'text to measure';
measuringSpan.style.display = 'none'; /*so you don't show that you are measuring*/
$('.style-head')[0].appendChild(measuringSpan);
var theWidthYouWant = $(measuringSpan).width();

Needless to say

theWidthYouWant

will hold the pixel length. Then remove the created elements after you are done or you will get several if this is done a several times. Or add an ID to reference instead.

Invalid default value for 'dateAdded'

CURRENT_TIMESTAMP is version specific and is now allowed for DATETIME columns as of version 5.6.

See MySQL docs.

Why does CSV file contain a blank line in between each data line when outputting with Dictwriter in Python

Changing the 'w' (write) in this line:

output = csv.DictWriter(open('file3.csv','w'), delimiter=',', fieldnames=headers)

To 'wb' (write binary) fixed this problem for me:

output = csv.DictWriter(open('file3.csv','wb'), delimiter=',', fieldnames=headers)

Python v2.75: Open()

Credit to @dandrejvv for the solution in the comment on the original post above.

Where is SQLite database stored on disk?

If you are running Rails (its the default db in Rails) check the {RAILS_ROOT}/config/database.yml file and you will see something like:

database: db/development.sqlite3

This means that it will be in the {RAILS_ROOT}/db directory.

How to replace all double quotes to single quotes using jquery?

You can also use replaceAll(search, replaceWith) [MDN].

Then, make sure you have a string by wrapping one type of quotes by a different type:

 'a "b" c'.replaceAll('"', "'")
 // result: "a 'b' c"
    
 'a "b" c'.replaceAll(`"`, `'`)
 // result: "a 'b' c"

 // Using RegEx. You MUST use a global RegEx(Meaning it'll match all occurrences).
 'a "b" c'.replaceAll(/\"/g, "'")
 // result: "a 'b' c"

Important(!) if you choose regex:

when using a regexp you have to set the global ("g") flag; otherwise, it will throw a TypeError: "replaceAll must be called with a global RegExp".

Toolbar Navigation Hamburger Icon missing

Here is the simplest solution that worked for me.

The ActionBarDrawerToggle has two types constructors. One of them take toolbar as a parameter. Use that (second one below) to get the animated hamburger.

ActionBarDrawerToggle(this, mDrawerLayout, R.string.content_desc_drawer_open, 
R.string.content_desc_drawer_close);

ActionBarDrawerToggle(this, mDrawerLayout, toolbar, R.string.content_desc_drawer_open, 
R.string.content_desc_drawer_close);`  //use this constructor

How to code a very simple login system with java

this is my first code on this site try this

import java.util.Scanner;
public class BATM {

public static void main(String[] args) {
    Scanner input = new Scanner(System.in);

    String username;
    String password;

    System.out.println("Log in:");
    System.out.println("username: ");
    username = input.next();

    System.out.println("password: ");
    password = input.next();

    //users check = new users(username, password);

    if(username.equals(username) && password.equals(password)) 
        System.out.println("You are logged in");



}

}

Does the join order matter in SQL?

For INNER joins, no, the order doesn't matter. The queries will return same results, as long as you change your selects from SELECT * to SELECT a.*, b.*, c.*.


For (LEFT, RIGHT or FULL) OUTER joins, yes, the order matters - and (updated) things are much more complicated.

First, outer joins are not commutative, so a LEFT JOIN b is not the same as b LEFT JOIN a

Outer joins are not associative either, so in your examples which involve both (commutativity and associativity) properties:

a LEFT JOIN b 
    ON b.ab_id = a.ab_id
  LEFT JOIN c
    ON c.ac_id = a.ac_id

is equivalent to:

a LEFT JOIN c 
    ON c.ac_id = a.ac_id
  LEFT JOIN b
    ON b.ab_id = a.ab_id

but:

a LEFT JOIN b 
    ON  b.ab_id = a.ab_id
  LEFT JOIN c
    ON  c.ac_id = a.ac_id
    AND c.bc_id = b.bc_id

is not equivalent to:

a LEFT JOIN c 
    ON  c.ac_id = a.ac_id
  LEFT JOIN b
    ON  b.ab_id = a.ab_id
    AND b.bc_id = c.bc_id

Another (hopefully simpler) associativity example. Think of this as (a LEFT JOIN b) LEFT JOIN c:

a LEFT JOIN b 
    ON b.ab_id = a.ab_id          -- AB condition
 LEFT JOIN c
    ON c.bc_id = b.bc_id          -- BC condition

This is equivalent to a LEFT JOIN (b LEFT JOIN c):

a LEFT JOIN  
    b LEFT JOIN c
        ON c.bc_id = b.bc_id          -- BC condition
    ON b.ab_id = a.ab_id          -- AB condition

only because we have "nice" ON conditions. Both ON b.ab_id = a.ab_id and c.bc_id = b.bc_id are equality checks and do not involve NULL comparisons.

You can even have conditions with other operators or more complex ones like: ON a.x <= b.x or ON a.x = 7 or ON a.x LIKE b.x or ON (a.x, a.y) = (b.x, b.y) and the two queries would still be equivalent.

If however, any of these involved IS NULL or a function that is related to nulls like COALESCE(), for example if the condition was b.ab_id IS NULL, then the two queries would not be equivalent.

How to get selected option using Selenium WebDriver with Java

In Selenium Python it is:

from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support.ui import Select

def get_selected_value_from_drop_down(self):
    try:
        select = Select(WebDriverWait(self.driver, 20).until(EC.element_to_be_clickable((By.ID, 'data_configuration_edit_data_object_tab_details_lb_use_for_match'))))
        return select.first_selected_option.get_attribute("value")
    except NoSuchElementException, e:
        print "Element not found "
        print e

Checking to see if one array's elements are in another array in PHP

Performance test for in_array vs array_intersect:

$a1 = array(2,4,8,11,12,13,14,15,16,17,18,19,20);

$a2 = array(3,20);

$intersect_times = array();
$in_array_times = array();
for($j = 0; $j < 10; $j++)
{
    /***** TEST ONE array_intersect *******/
    $t = microtime(true);
    for($i = 0; $i < 100000; $i++)
    {
        $x = array_intersect($a1,$a2);
        $x = empty($x);
    }
    $intersect_times[] = microtime(true) - $t;


    /***** TEST TWO in_array *******/
    $t2 = microtime(true);
    for($i = 0; $i < 100000; $i++)
    {
        $x = false;
        foreach($a2 as $v){
            if(in_array($v,$a1))
            {
                $x = true;
                break;
            }
        }
    }
    $in_array_times[] = microtime(true) - $t2;
}

echo '<hr><br>'.implode('<br>',$intersect_times).'<br>array_intersect avg: '.(array_sum($intersect_times) / count($intersect_times));
echo '<hr><br>'.implode('<br>',$in_array_times).'<br>in_array avg: '.(array_sum($in_array_times) / count($in_array_times));
exit;

Here are the results:

0.26520013809204
0.15600109100342
0.15599989891052
0.15599989891052
0.1560001373291
0.1560001373291
0.15599989891052
0.15599989891052
0.15599989891052
0.1560001373291
array_intersect avg: 0.16692011356354

0.015599966049194
0.031199932098389
0.031200170516968
0.031199932098389
0.031200885772705
0.031199932098389
0.031200170516968
0.031201124191284
0.031199932098389
0.031199932098389
in_array avg: 0.029640197753906

in_array is at least 5 times faster. Note that we "break" as soon as a result is found.

Enabling the OpenSSL in XAMPP

Yes, you must open php.ini and remove the semicolon to:

;extension=php_openssl.dll

If you don't have that line, check that you have the file (In my PC is on D:\xampp\php\ext) and add this to php.ini in the "Dynamic Extensions" section:

extension=php_openssl.dll

Things have changed for PHP > 7. This is what i had to do for PHP 7.2.

Step: 1: Uncomment extension=openssl

Step: 2: Uncomment extension_dir = "ext"

Step: 3: Restart xampp.

Done.

Explanation: ( From php.ini )

If you wish to have an extension loaded automatically, use the following syntax:

extension=modulename

Note : The syntax used in previous PHP versions (extension=<ext>.so and extension='php_<ext>.dll) is supported for legacy reasons and may be deprecated in a future PHP major version. So, when it is possible, please move to the new (extension=<ext>) syntax.

Special Note: Be sure to appropriately set the extension_dir directive.

how to get session id of socket.io client in Client

Try this way.

                var socket = io.connect('http://...');
                console.log(socket.Socket.sessionid);

Call to getLayoutInflater() in places not in activity

LayoutInflater inflater = (LayoutInflater) context.getSystemService( Context.LAYOUT_INFLATER_SERVICE );

Use this instead!

How do I find the version of Apache running without access to the command line?

Use this PHP script:

 $version = apache_get_version();
    echo "$version\n";

Se apache_get_version.

tsc is not recognized as internal or external command

You need to run:

npx tsc

...rather than just calling tsc own its on like a Windows command as everyone else seems to be suggesting.

If you don't have npx installed then you should. It should be installed globally (unlike Typescript). So first run:

npm install -g npx

..then run npx tsc.

static linking only some libraries

Some loaders (linkers) provide switches for turning dynamic loading on and off. If GCC is running on such a system (Solaris - and possibly others), then you can use the relevant option.

If you know which libraries you want to link statically, you can simply specify the static library file in the link line - by full path.

How to format background color using twitter bootstrap?

Just add a div around the container so it looks like:

<div style="background: red;">
  <div class="container marketing">
    <h2 style="padding-top: 60px;"></h2>
  </div>
</div>

Node.js res.setHeader('content-type', 'text/javascript'); pushing the response javascript as file download

Use application/javascript as content type instead of text/javascript

text/javascript is mentioned obsolete. See reference docs.

http://www.iana.org/assignments/media-types/application

Also see this question on SO.

UPDATE:

I have tried executing the code you have given and the below didn't work.

res.setHeader('content-type', 'text/javascript');
res.send(JS_Script);

This is what worked for me.

res.setHeader('content-type', 'text/javascript');
res.end(JS_Script);

As robertklep has suggested, please refer to the node http docs, there is no response.send() there.

Node.js - SyntaxError: Unexpected token import

As mentioned in other answers Node JS currently doesn't support ES6 imports.

(As of now, read EDIT 2)

Enable ES6 imports in node js provides a solution to this issue. I have tried this and it worked for me.

Run the command:

    npm install babel-register babel-preset-env --save-dev

Now you need to create a new file (config.js) and add the following code to it.

    require('babel-register')({
        presets: [ 'env' ]
    })
    // Import the rest of our application.
    module.exports = require('./your_server_file.js')

Now you can write import statements without getting any errors.

Hope this helps.

EDIT:

You need to run the new file which you created with above code. In my case it was config.js. So I have to run:

    node config.js

EDIT 2:

While experimenting, I found one easy solution to this issue.

Create .babelrc file in the root of your project.

Add following (and any other babel presets you need, can be added in this file):

    {
        "presets": ["env"]
    }

Install babel-preset-env using command npm install babel-preset-env --save, and then install babel-cli using command npm install babel-cli -g --save

Now, go to the folder where your server or index file exists and run using: babel-node fileName.js

Or you can run using npm start by adding following code to your package.json file:

    "scripts": {
        "start": "babel-node src/index.js"
    }

Android : difference between invisible and gone?

INVISIBLE:
The view has to be drawn and it takes time.

GONE:
The view doesn't have to be drawn.

SyntaxError: Unexpected token function - Async Await Nodejs

Though I'm coming in late, what worked for me was to install transform-async-generator and transform-runtime plugin like so:

npm i babel-plugin-transform-async-to-generator babel-plugin-transform-runtime --save-dev

the package.json would be like this:

"devDependencies": {
   "babel-plugin-transform-async-to-generator": "6.24.1",
   "babel-plugin-transform-runtime": "6.23.0"
}

create .babelrc file and write this:

{
  "plugins": ["transform-async-to-generator", 
["transform-runtime", {
      "polyfill": false,
      "regenerator": true
    }]
]
}

and then happy coding with async/await

Importing CSV with line breaks in Excel 2007

I had a similar problem. I had some twitter data in MySQL. The data had Line feed( LF or \n) with in the data. I had a requirement of exporting the MySQL data into excel. The LF was messing up my import of csv file. So I did the following -

1. From MySQL exported to CSV with Record separator as CRLF
2. Opened the data in notepad++ 
3. Replaced CRLF (\r\n) with some string I am not expecting in the Data. I used ###~###! as replacement of CRLF
4. Replaced LF (\n) with Space
5. Replaced ###~###! with \r\n, so my record separator are back.
6. Saved and then imported into Excel

NOTE- While replacing CRLF or LF dont forget to Check Excended (\n,\r,\t... Checkbox [look at the left hand bottom of the Dialog Box)

Accessing Websites through a Different Port?

You can run the web server on any port. 80 is just convention as are 8080 (web server on unprivileged port) and 443 (web server + ssl). However if you're looking to see some web site by pointing your browser to a different port you're probably out of luck. Unless the web server is being run on that port explicitly you'll just get an error message.

Rails 4: List of available datatypes

You might also find it useful to know generally what these data types are used for:

There's also references used to create associations. But, I'm not sure this is an actual data type.

New Rails 4 datatypes available in PostgreSQL:

  • :hstore - storing key/value pairs within a single value (learn more about this new data type)
  • :array - an arrangement of numbers or strings in a particular row (learn more about it and see examples)
  • :cidr_address - used for IPv4 or IPv6 host addresses
  • :inet_address - used for IPv4 or IPv6 host addresses, same as cidr_address but it also accepts values with nonzero bits to the right of the netmask
  • :mac_address - used for MAC host addresses

Learn more about the address datatypes here and here.

Also, here's the official guide on migrations: http://edgeguides.rubyonrails.org/migrations.html

How to convert Double to int directly?

If you really should use Double instead of double you even can get the int Value of Double by calling:

Double d = new Double(1.23);
int i = d.intValue();

Else its already described by Peter Lawreys answer.

Python Requests library redirect new url

I think requests.head instead of requests.get will be more safe to call when handling url redirect,check the github issue here:

r = requests.head(url, allow_redirects=True)
print(r.url)

How to delete specific columns with VBA?

You were just missing the second half of the column statement telling it to remove the entire column, since most normal Ranges start with a Column Letter, it was looking for a number and didn't get one. The ":" gets the whole column, or row.

I think what you were looking for in your Range was this:

Range("C:C,F:F,I:I,L:L,O:O,R:R").Delete

Just change the column letters to match your needs.

What is the use of the init() usage in JavaScript?

In JavaScript when you create any object through a constructor call like below

step 1 : create a function say Person..

function Person(name){
this.name=name;
}
person.prototype.print=function(){
console.log(this.name);
}

step 2 : create an instance for this function..

var obj=new Person('venkat')

//above line will instantiate this function(Person) and return a brand new object called Person {name:'venkat'}

if you don't want to instantiate this function and call at same time.we can also do like below..

var Person = {
  init: function(name){
    this.name=name;
  },
  print: function(){
    console.log(this.name);
  }
};
var obj=Object.create(Person);
obj.init('venkat');
obj.print();

in the above method init will help in instantiating the object properties. basically init is like a constructor call on your class.

How to redirect to Index from another controller?

You can use local redirect. Following codes are jumping the HomeController's Index page:

public class SharedController : Controller
    {
        // GET: /<controller>/
        public IActionResult _Layout(string btnLogout)
        {
            if (btnLogout != null)
            {
                return LocalRedirect("~/Index");
            }

            return View();
        }
}

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 23: ordinal not in range(128)

You are encoding to UTF-8, then re-encoding to UTF-8. Python can only do this if it first decodes again to Unicode, but it has to use the default ASCII codec:

>>> u'ñ'
u'\xf1'
>>> u'ñ'.encode('utf8')
'\xc3\xb1'
>>> u'ñ'.encode('utf8').encode('utf8')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 0: ordinal not in range(128)

Don't keep encoding; leave encoding to UTF-8 to the last possible moment instead. Concatenate Unicode values instead.

You can use str.join() (or, rather, unicode.join()) here to concatenate the three values with dashes in between:

nombre = u'-'.join(fabrica, sector, unidad)
return nombre.encode('utf-8')

but even encoding here might be too early.

Rule of thumb: decode the moment you receive the value (if not Unicode values supplied by an API already), encode only when you have to (if the destination API does not handle Unicode values directly).

Java Reflection: How to get the name of a variable?

You can do like this:

Field[] fields = YourClass.class.getDeclaredFields();
//gives no of fields
System.out.println(fields.length);         
for (Field field : fields) {
    //gives the names of the fields
    System.out.println(field.getName());   
}

What is use of c_str function In c++

Oh must add my own pick here, you will use this when you encode/decode some string obj you transfer between two programs.

Lets say you use base64encode some array in python, and then you want to decode that into c++. Once you have the string you decode from base64decode in c++. In order to get it back to array of float, all you need to do here is

float arr[1024];
memcpy(arr, ur_string.c_str(), sizeof(float) * 1024);

This is pretty common use I suppose.

Understanding MongoDB BSON Document size limit

To post a clarification answer here for those who get directed here by Google.

The document size includes everything in the document including the subdocuments, nested objects etc.

So a document of:

{
  "_id": {},
  "na": [1, 2, 3],
  "naa": [
    { "w": 1, "v": 2, "b": [1, 2, 3] },
    { "w": 5, "b": 2, "h": [{ "d": 5, "g": 7 }, {}] }
  ]
}

Has a maximum size of 16 MB.

Subdocuments and nested objects are all counted towards the size of the document.

Send file using POST from a Python script

The only thing that stops you from using urlopen directly on a file object is the fact that the builtin file object lacks a len definition. A simple way is to create a subclass, which provides urlopen with the correct file. I have also modified the Content-Type header in the file below.

import os
import urllib2
class EnhancedFile(file):
    def __init__(self, *args, **keyws):
        file.__init__(self, *args, **keyws)

    def __len__(self):
        return int(os.fstat(self.fileno())[6])

theFile = EnhancedFile('a.xml', 'r')
theUrl = "http://example.com/abcde"
theHeaders= {'Content-Type': 'text/xml'}

theRequest = urllib2.Request(theUrl, theFile, theHeaders)

response = urllib2.urlopen(theRequest)

theFile.close()


for line in response:
    print line

Count all occurrences of a string in lots of files with grep

You can use a simple grep to capture the number of occurrences effectively. I will use the -i option to make sure STRING/StrING/string get captured properly.

Command line that gives the files' name:

grep -oci string * | grep -v :0

Command line that removes the file names and prints 0 if there is a file without occurrences:

grep -ochi string *

How do I disable a href link in JavaScript?

You can simply give it an empty hash:

anchor.href = "#";

or if that's not good enough of a "disable", use an event handler:

anchor.href = "javascript:void(0)";

How to detect the screen resolution with JavaScript?

if you mean browser resolution then

window.innerWidth gives you the browser resolution

you can test with http://howbigismybrowser.com/ try changing your screen resolution by zoom in / out browser and check resolution size with http://howbigismybrowser.com/ enter image description here Window.innerWidth should be same as screen resolution width

Bootstrap Accordion button toggle "data-parent" not working

Here is a (hopefully) universal patch I developed to fix this problem for BootStrap V3. No special requirements other than plugging in the script.

$(':not(.panel) > [data-toggle="collapse"][data-parent]').click(function() {
    var parent = $(this).data('parent');
    var items = $('[data-toggle="collapse"][data-parent="' + parent + '"]').not(this);
    items.each(function() {
        var target = $(this).data('target') || '#' + $(this).prop('href').split('#')[1];
        $(target).filter('.in').collapse('hide');
    });
});

EDIT: Below is a simplified answer which still meets my needs, and I'm now using a delegated click handler:

$(document.body).on('click', ':not(.panel) > [data-toggle="collapse"][data-parent]', function() {
    var parent = $(this).data('parent');
    var target = $(this).data('target') || $(this).prop('hash');
    $(parent).find('.collapse.in').not(target).collapse('hide');
});

How to insert multiple rows from array using CodeIgniter framework?

$query= array(); 
foreach( $your_data as $row ) {
    $query[] = '("'.mysql_real_escape_string($row['text']).'", '.$row['category_id'].')';
}
mysql_query('INSERT INTO table (text, category) VALUES '.implode(',', $query));

Is there a way to follow redirects with command line cURL?

As said, to follow redirects you can use the flag -L or --location:

curl -L http://www.example.com

But, if you want limit the number of redirects, add the parameter --max-redirs

--max-redirs <num>

Set maximum number of redirection-followings allowed. If -L, --location is used, this option can be used to prevent curl from following redirections "in absurdum". By default, the limit is set to 50 redirections. Set this option to -1 to make it limitless. If this option is used several times, the last one will be used.

How do I change the IntelliJ IDEA default JDK?

The above responses were very useful, but after all settings, the project was running with the wrong version. Finally, I noticed that it can be also configured in the Dependencies window. Idea 2018.1.3 File -> Project Structure -> Modules -> Sources and Dependencies.

how to convert integer to string?

NSString* myNewString = [NSString stringWithFormat:@"%d", myInt];

How do I view the SQL generated by the Entity Framework?

Well, I am using Express profiler for that purpose at the moment, the drawback is that it only works for MS SQL Server. You can find this tool here: https://expressprofiler.codeplex.com/

LINQ to Entities does not recognize the method 'System.String ToString()' method, and this method cannot be translated into a store expression

Cast table to Enumerable, then you call LINQ methods with using ToString() method inside:

    var example = contex.table_name.AsEnumerable()
.Select(x => new {Date = x.date.ToString("M/d/yyyy")...)

But be careful, when you calling AsEnumerable or ToList methods because you will request all data from all entity before this method. In my case above I read all table_name rows by one request.

jQuery 1.9 .live() is not a function

.live() was deprecated and has now been removed from jQuery 1.9 You should use .on()

Getting "java.nio.file.AccessDeniedException" when trying to write to a folder

Not the answer for this question

I got this exception when trying to delete a folder where i deleted the file inside.

Example:

createFolder("folder");  
createFile("folder/file");  
deleteFile("folder/file");  
deleteFolder("folder"); // error here

While deleteFile("folder/file"); returned that it was deleted, the folder will only be considered empty after the program restart.

On some operating systems it may not be possible to remove a file when it is open and in use by this Java virtual machine or other programs.

https://docs.oracle.com/javase/8/docs/api/java/nio/file/Files.html#delete-java.nio.file.Path-

Explanation from dhke

Flask SQLAlchemy query, specify column names

session.query().with_entities(SomeModel.col1)

is the same as

session.query(SomeModel.col1)

for alias, we can use .label()

session.query(SomeModel.col1.label('some alias name'))

How do I configure git to ignore some files locally?

You can install some git aliases to make this process simpler. This edits the [alias] node of your .gitconfig file.

git config --global alias.ignore 'update-index --skip-worktree'
git config --global alias.unignore 'update-index --no-skip-worktree'
git config --global alias.ignored '!git ls-files -v | grep "^S"'

The shortcuts this installs for you are as follows:

  • git ignore config.xml
    • git will pretend that it doesn't see any changes upon config.xml — preventing you from accidentally committing those changes.
  • git unignore config.xml
    • git will resume acknowledging your changes to config.xml — allowing you again to commit those changes.
  • git ignored
    • git will list all the files which you are "ignoring" in the manner described above.

I built these by referring to phatmann's answer — which presents an --assume-unchanged version of the same.

The version I present uses --skip-worktree for ignoring local changes. See Borealid's answer for a full explanation of the difference, but essentially --skip-worktree's purpose is for developers to change files without the risk of committing their changes.

The git ignored command presented here uses git ls-files -v, and filters the list to show just those entries beginning with the S tag. The S tag denotes a file whose status is "skip worktree". For a full list of the file statuses shown by git ls-files: see the documentation for the -t option on git ls-files.

How to fix "containing working copy admin area is missing" in SVN?

I had this error recently. It was caused by root owning a couple of files in the directory giving this error.

After I changed the permissions everything worked as expected.

How do you use bcrypt for hashing passwords in PHP?

You'll get a lot of information in Enough With The Rainbow Tables: What You Need To Know About Secure Password Schemes or Portable PHP password hashing framework.

The goal is to hash the password with something slow, so someone getting your password database will die trying to brute force it (a 10 ms delay to check a password is nothing for you, a lot for someone trying to brute force it). Bcrypt is slow and can be used with a parameter to choose how slow it is.

How to get a particular date format ('dd-MMM-yyyy') in SELECT query SQL Server 2008 R2

select CONVERT(NVARCHAR, SYSDATETIME(), 106) AS [DD-MON-YYYY]

or else

select REPLACE(CONVERT(NVARCHAR,GETDATE(), 106), ' ', '-')

both works fine

NSRange to Range<String.Index>

I've found the cleanest swift2 only solution is to create a category on NSRange:

extension NSRange {
    func stringRangeForText(string: String) -> Range<String.Index> {
        let start = string.startIndex.advancedBy(self.location)
        let end = start.advancedBy(self.length)
        return Range<String.Index>(start: start, end: end)
    }
}

And then call it from for text field delegate function:

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
    let range = range.stringRangeForText(textField.text)
    let output = textField.text.stringByReplacingCharactersInRange(range, withString: string)

    // your code goes here....

    return true
}

Matplotlib (pyplot) savefig outputs blank image

let's me give a more detail example:

import numpy as np
import matplotlib.pyplot as plt


def draw_result(lst_iter, lst_loss, lst_acc, title):
    plt.plot(lst_iter, lst_loss, '-b', label='loss')
    plt.plot(lst_iter, lst_acc, '-r', label='accuracy')

    plt.xlabel("n iteration")
    plt.legend(loc='upper left')
    plt.title(title)
    plt.savefig(title+".png")  # should before plt.show method

    plt.show()


def test_draw():
    lst_iter = range(100)
    lst_loss = [0.01 * i + 0.01 * i ** 2 for i in xrange(100)]
    # lst_loss = np.random.randn(1, 100).reshape((100, ))
    lst_acc = [0.01 * i - 0.01 * i ** 2 for i in xrange(100)]
    # lst_acc = np.random.randn(1, 100).reshape((100, ))
    draw_result(lst_iter, lst_loss, lst_acc, "sgd_method")


if __name__ == '__main__':
    test_draw()

enter image description here

Writing an Excel file in EPPlus

If you have a collection of objects that you load using stored procedure you can also use LoadFromCollection.

using (ExcelPackage package = new ExcelPackage(file))
{
    ExcelWorksheet worksheet = package.Workbook.Worksheets.Add("test");

    worksheet.Cells["A1"].LoadFromCollection(myColl, true, OfficeOpenXml.Table.TableStyles.Medium1);

    package.Save();
}

Add list to set?

Please notice the function set.update(). The documentation says:

Update a set with the union of itself and others.

Cannot open include file with Visual Studio

I found this post because I was having the same error in Microsoft Visual C++. (Though it seems it's cause was a little different, than the above posted question.)

I had placed the file, I was trying to include, in the same directory, but it still could not be found.

My include looked like this: #include <ftdi.h>

But When I changed it to this: #include "ftdi.h" then it found it.

Center Div inside another (100% width) div

.outerdiv {
    margin-left: auto;
    margin-right: auto;
    display: table;
}

Doesn't work in internet explorer 7... but who cares ?

Invalid argument supplied for foreach()

More concise extension of @Kris's code

function secure_iterable($var)
{
    return is_iterable($var) ? $var : array();
}

foreach (secure_iterable($values) as $value)
{
     //do stuff...
}

especially for using inside template code

<?php foreach (secure_iterable($values) as $value): ?>
    ...
<?php endforeach; ?>

How to write both h1 and h2 in the same line?

h1 and h2 are native display: block elements.

Make them display: inline so they behave like normal text.

You should also reset the default padding and margin that the elements have.

find_spec_for_exe': can't find gem bundler (>= 0.a) (Gem::GemNotFoundException)

The real answer is here if you try to install bundler 2.0.1 or 2.0.0 due to Bundler requiring RubyGems v3.0.0

Yesterday I released Bundler 2.0 that introduced a number of breaking changes. One of the those changes was setting Bundler to require RubyGems v3.0.0. After making the release, it has become clear that lots of our users are running into issues with Bundler 2 requiring a really new version of RubyGems.

We have been listening closely to feedback from users and have decided to relax the RubyGems requirement to v2.5.0 at minimum. We have released a new Bundler version, v2.0.1, that adjusts this requirement.

For more info, see: https://bundler.io/blog/2019/01/04/an-update-on-the-bundler-2-release.html

Twitter Bootstrap Form File Element Upload Button

Upload buttons are a pain to style because it styles the input and not the button.

but you can use this trick:

http://www.quirksmode.org/dom/inputfile.html

Summary:

  1. Take a normal <input type="file"> and put it in an element with position: relative.

  2. To this same parent element, add a normal <input> and an image, which have the correct styles. Position these elements absolutely, so that they occupy the same place as the <input type="file">.

  3. Set the z-index of the <input type="file"> to 2 so that it lies on top of the styled input/image.

  4. Finally, set the opacity of the <input type="file"> to 0. The <input type="file"> now becomes effectively invisible, and the styles input/image shines through, but you can still click on the "Browse" button. If the button is positioned on top of the image, the user appears to click on the image and gets the normal file selection window. (Note that you can't use visibility: hidden, because a truly invisible element is unclickable, too, and we need the to remain clickable)

Use mysql_fetch_array() with foreach() instead of while()

You can code like this:

$query_select = "SELECT * FROM shouts ORDER BY id DESC LIMIT 8;";
$result_select = mysql_query($query_select) or die(mysql_error());
$rows = array();
while($row = mysql_fetch_array($result_select))
    $rows[] = $row;
foreach($rows as $row){ 
    $ename = stripslashes($row['name']);
    $eemail = stripcslashes($row['email']);
    $epost = stripslashes($row['post']);
    $eid = $row['id'];

    $grav_url = "http://www.gravatar.com/avatar.php?gravatar_id=".md5(strtolower($eemail))."&size=70";

    echo ('<img src = "' . $grav_url . '" alt="Gravatar">'.'<br/>');

    echo $eid . '<br/>';

    echo $ename . '<br/>';

    echo $eemail . '<br/>';

    echo $epost . '<br/><br/><br/><br/>';
}

As you can see, it's still need a loop while to get data from mysql_fetch_array

What is the @Html.DisplayFor syntax for?

After looking for an answer for myself for some time, i could find something. in general if we are using it for just one property it appears same even if we do a "View Source" of generated HTML Below is generated HTML for example, when i want to display only Name property for my class

    <td>
    myClassNameProperty
    </td>
   <td>
    myClassNameProperty, This is direct from Item
    </td>

This is the generated HTML from below code

<td>
@Html.DisplayFor(modelItem=>item.Genre.Name)            
</td>

<td>
@item.Genre.Name, This is direct from Item
</td>

At the same time now if i want to display all properties in one statement for my class "Genre" in this case, i can use @Html.DisplayFor() to save on my typing, for least

i can write @Html.DisplayFor(modelItem=>item.Genre) in place of writing a separate statement for each property of Genre as below

@item.Genre.Name
@item.Genre.Id
@item.Genre.Description

and so on depending on number of properties.

convert pfx format to p12

Run this command to change .cert file to .p12:

openssl pkcs12 -export -out server.p12 -inkey server.key -in server.crt 

Where server.key is the server key and server.cert is a CA issue cert or a self sign cert file.

PHP CURL CURLOPT_SSL_VERIFYPEER ignored

According to documentation: to verify host or peer certificate you need to specify alternate certificates with the CURLOPT_CAINFO option or a certificate directory can be specified with the CURLOPT_CAPATH option.

Also look at CURLOPT_SSL_VERIFYHOST:

  • 1 to check the existence of a common name in the SSL peer certificate.
  • 2 to check the existence of a common name and also verify that it matches the hostname provided.

curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);

How to read file with async/await properly?

You can use fs.promises available natively since Node v11.0.0

import fs from 'fs';

const readFile = async filePath => {
  try {
    const data = await fs.promises.readFile(filePath, 'utf8')
    return data
  }
  catch(err) {
    console.log(err)
  }
}

How to close current tab in a browser window?

<button class="closeButton" style="cursor: pointer" onclick="window.close();">Close Window</button>

this did the work for me

Reinitialize Slick js after successful ajax call

$('#slick-slider').slick('refresh'); //Working for slick 1.8.1

Get exit code of a background process

As I see almost all answers use external utilities (mostly ps) to poll the state of the background process. There is a more unixesh solution, catching the SIGCHLD signal. In the signal handler it has to be checked which child process was stopped. It can be done by kill -0 <PID> built-in (universal) or checking the existence of /proc/<PID> directory (Linux specific) or using the jobs built-in ( specific. jobs -l also reports the pid. In this case the 3rd field of the output can be Stopped|Running|Done|Exit . ).

Here is my example.

The launched process is called loop.sh. It accepts -x or a number as an argument. For -x is exits with exit code 1. For a number it waits num*5 seconds. In every 5 seconds it prints its PID.

The launcher process is called launch.sh:

#!/bin/bash

handle_chld() {
    local tmp=()
    for((i=0;i<${#pids[@]};++i)); do
        if [ ! -d /proc/${pids[i]} ]; then
            wait ${pids[i]}
            echo "Stopped ${pids[i]}; exit code: $?"
        else tmp+=(${pids[i]})
        fi
    done
    pids=(${tmp[@]})
}

set -o monitor
trap "handle_chld" CHLD

# Start background processes
./loop.sh 3 &
pids+=($!)
./loop.sh 2 &
pids+=($!)
./loop.sh -x &
pids+=($!)

# Wait until all background processes are stopped
while [ ${#pids[@]} -gt 0 ]; do echo "WAITING FOR: ${pids[@]}"; sleep 2; done
echo STOPPED

For more explanation see: Starting a process from bash script failed

How do I convert Word files to PDF programmatically?

I went through the Word to PDF pain when someone dumped me with 10000 word files to convert to PDF. Now I did it in C# and used Word interop but it was slow and crashed if I tried to use PC at all.. very frustrating.

This lead me to discovering I could dump interops and their slowness..... for Excel I use (EPPLUS) and then I discovered that you can get a free tool called Spire that allows converting to PDF... with limitations!

http://www.e-iceblue.com/Introduce/free-doc-component.html#.VtAg4PmLRhE

How to change Windows 10 interface language on Single Language version

You can download language pack and use "Install or Uninstall display languages" wizard. To do this:

  • Press Win+R, paste lpksetup and press Enter
  • Wizard will appear on the screen
  • Click the Install display languages button
  • In the next page of the wizard, click Browse and pick the *.cab file of the MUI language you downloaded
  • Click the Next button to install language

How do you uninstall MySQL from Mac OS X?

I also had entries in:

/Library/Receipts/InstallHistory.plist

that i had to delete.

Write to rails console

I think you should use the Rails debug options:

logger.debug "Person attributes hash: #{@person.attributes.inspect}"
logger.info "Processing the request..."
logger.fatal "Terminating application, raised unrecoverable error!!!"

https://guides.rubyonrails.org/debugging_rails_applications.html

Android Support Design TabLayout: Gravity Center and Mode Scrollable

This is the solution I used to automatically change between SCROLLABLE and FIXED+FILL. It is the complete code for the @Fighter42 solution:

(The code below shows where to put the modification if you've used Google's tabbed activity template)

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    // Create the adapter that will return a fragment for each of the three
    // primary sections of the activity.
    mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.container);
    mViewPager.setAdapter(mSectionsPagerAdapter);

    // Set up the tabs
    final TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
    tabLayout.setupWithViewPager(mViewPager);

    // Mario Velasco's code
    tabLayout.post(new Runnable()
    {
        @Override
        public void run()
        {
            int tabLayoutWidth = tabLayout.getWidth();

            DisplayMetrics metrics = new DisplayMetrics();
            ActivityMain.this.getWindowManager().getDefaultDisplay().getMetrics(metrics);
            int deviceWidth = metrics.widthPixels;

            if (tabLayoutWidth < deviceWidth)
            {
                tabLayout.setTabMode(TabLayout.MODE_FIXED);
                tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
            } else
            {
                tabLayout.setTabMode(TabLayout.MODE_SCROLLABLE);
            }
        }
    });
}

Layout:

    <android.support.design.widget.TabLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal" />

If you don't need to fill width, better to use @karaokyo solution.

If statement for strings in python?

Python is case sensitive and needs proper indentation. You need to use lowercase "if", indent your conditions properly and the code has a bug. proceed will evaluate to y

jQuery .ready in a dynamically inserted iframe

Found the solution to the problem.

When you click on a thickbox link that open a iframe, it insert an iframe with an id of TB_iframeContent.

Instead of relying on the $(document).ready event in the iframe code, I just have to bind to the load event of the iframe in the parent document:

$('#TB_iframeContent', top.document).load(ApplyGalleria);

This code is in the iframe but binds to an event of a control in the parent document. It works in FireFox and IE.

How to open new browser window on button click event?

You can use some code like this, you can adjust a height and width as per your need

    protected void button_Click(object sender, EventArgs e)
    {
        // open a pop up window at the center of the page.
        ScriptManager.RegisterStartupScript(this, typeof(string), "OPEN_WINDOW", "var Mleft = (screen.width/2)-(760/2);var Mtop = (screen.height/2)-(700/2);window.open( 'your_page.aspx', null, 'height=700,width=760,status=yes,toolbar=no,scrollbars=yes,menubar=no,location=no,top=\'+Mtop+\', left=\'+Mleft+\'' );", true);
    }

How to install requests module in Python 3.4, instead of 2.7

i was facing same issue in beautiful soup , I solved this issue by this command , your issue will also get rectified . You are unable to install requests in python 3.4 because your python libraries are not updated . use this command apt-get install python3-requests Just run it will ask you to add 222 MB space in your hard disk , just press Y and wait for completing process, after ending up whole process . check your problem will be resolved.

Convert an array to string

You can join your array using the following:

string.Join(",", Client);

Then you can output anyway you want. You can change the comma to what ever you want, a space, a pipe, or whatever.

Send JSON data via POST (ajax) and receive json response from Controller (MVC)

var SendInfo= { SendInfo: [... your elements ...]};

        $.ajax({
            type: 'post',
            url: 'Your-URI',
            data: JSON.stringify(SendInfo),
            contentType: "application/json; charset=utf-8",
            traditional: true,
            success: function (data) {
                ...
            }
        });

and in action

public ActionResult AddDomain(IEnumerable<PersonSheets> SendInfo){
...

you can bind your array like this

var SendInfo = [];

$(this).parents('table').find('input:checked').each(function () {
    var domain = {
        name: $("#id-manuf-name").val(),
        address: $("#id-manuf-address").val(),
        phone: $("#id-manuf-phone").val(),
    }

    SendInfo.push(domain);
});

hope this can help you.

What is the effect of encoding an image in base64?

It will be approximately 37% larger:

Very roughly, the final size of Base64-encoded binary data is equal to 1.37 times the original data size

Source: http://en.wikipedia.org/wiki/Base64

How can I change an element's class with JavaScript?

Just thought I'd throw this in:

function inArray(val, ary){
  for(var i=0,l=ary.length; i<l; i++){
    if(ary[i] === val){
      return true;
    }
  }
  return false;
}
function removeClassName(classNameS, fromElement){
  var x = classNameS.split(/\s/), s = fromElement.className.split(/\s/), r = [];
  for(var i=0,l=s.length; i<l; i++){
    if(!iA(s[i], x))r.push(s[i]);
  }
  fromElement.className = r.join(' ');
}
function addClassName(classNameS, toElement){
  var s = toElement.className.split(/\s/);
  s.push(c); toElement.className = s.join(' ');
}

JavaScript - Get minutes between two dates

Subtracting 2 Date objects gives you the difference in milliseconds, e.g.:

var diff = Math.abs(new Date('2011/10/09 12:00') - new Date('2011/10/09 00:00'));

Math.abs is used to be able to use the absolute difference (so new Date('2011/10/09 00:00') - new Date('2011/10/09 12:00') gives the same result).

Dividing the result by 1000 gives you the number of seconds. Dividing that by 60 gives you the number of minutes. To round to whole minutes, use Math.floor or Math.ceil:

var minutes = Math.floor((diff/1000)/60);

In this example the result will be 720

Compare every item to every other item in ArrayList

What's the problem with using for loop inside, just like outside?

for (int j = i + 1; j < list.size(); ++j) {
    ...
}

In general, since Java 5, I used iterators only once or twice.

Difference between 3NF and BCNF in simple terms (must be able to explain to an 8-year old)

The difference between BCNF and 3NF

Using the BCNF definition

If and only if for every one of its dependencies X ? Y, at least one of the following conditions hold:

  • X ? Y is a trivial functional dependency (Y ? X), or
  • X is a super key for schema R

and the 3NF definition

If and only if, for each of its functional dependencies X ? A, at least one of the following conditions holds:

  • X contains A (that is, X ? A is trivial functional dependency), or
  • X is a superkey, or
  • Every element of A-X, the set difference between A and X, is a prime attribute (i.e., each attribute in A-X is contained in some candidate key)

We see the following difference, in simple terms:

  • In BCNF: Every partial key (prime attribute) can only depend on a superkey,

whereas

  • In 3NF: A partial key (prime attribute) can also depend on an attribute that is not a superkey (i.e. another partial key/prime attribute or even a non-prime attribute).

Where

  1. A prime attribute is an attribute found in a candidate key, and
  2. A candidate key is a minimal superkey for that relation, and
  3. A superkey is a set of attributes of a relation variable for which it holds that in all relations assigned to that variable, there are no two distinct tuples (rows) that have the same values for the attributes in this set.Equivalently a superkey can also be defined as a set of attributes of a relation schema upon which all attributes of the schema are functionally dependent. (A superkey always contains a candidate key/a candidate key is always a subset of a superkey. You can add any attribute in a relation to obtain one of the superkeys.)

That is, no partial subset (any non trivial subset except the full set) of a candidate key can be functionally dependent on anything other than a superkey.

A table/relation not in BCNF is subject to anomalies such as the update anomalies mentioned in the pizza example by another user. Unfortunately,

  • BNCF cannot always be obtained, while
  • 3NF can always be obtained.

3NF Versus BCNF Example

An example of the difference can currently be found at "3NF table not meeting BCNF (Boyce–Codd normal form)" on Wikipedia, where the following table meets 3NF but not BCNF because "Tennis Court" (a partial key/prime attribute) depends on "Rate Type" (a partial key/prime attribute that is not a superkey), which is a dependency we could determine by asking the clients of the database, the tennis club:

Today's Tennis Court Bookings (3NF, not BCNF)

Court   Start Time  End Time    Rate Type
------- ----------  --------    ---------
1       09:30       10:30       SAVER
1       11:00       12:00       SAVER
1       14:00       15:30       STANDARD
2       10:00       11:30       PREMIUM-B
2       11:30       13:30       PREMIUM-B
2       15:00       16:30       PREMIUM-A

The table's superkeys are:

S1 = {Court, Start Time}
S2 = {Court, End Time}
S3 = {Rate Type, Start Time}
S4 = {Rate Type, End Time}
S5 = {Court, Start Time, End Time}
S6 = {Rate Type, Start Time, End Time}
S7 = {Court, Rate Type, Start Time}
S8 = {Court, Rate Type, End Time}
ST = {Court, Rate Type, Start Time, End Time}, the trivial superkey

The 3NF problem: The partial key/prime attribute "Court" is dependent on something other than a superkey. Instead, it is dependent on the partial key/prime attribute "Rate Type". This means that the user must manually change the rate type if we upgrade a court, or manually change the court if wanting to apply a rate change.

  • But what if the user upgrades the court but does not remember to increase the rate? Or what if the wrong rate type is applied to a court?

(In technical terms, we cannot guarantee that the "Rate Type" -> "Court" functional dependency will not be violated.)

The BCNF solution: If we want to place the above table in BCNF we can decompose the given relation/table into the following two relations/tables (assuming we know that the rate type is dependent on only the court and membership status, which we could discover by asking the clients of our database, the owners of the tennis club):

Rate Types (BCNF and the weaker 3NF, which is implied by BCNF)

Rate Type   Court   Member Flag
---------   -----   -----------
SAVER       1       Yes
STANDARD    1       No
PREMIUM-A   2       Yes
PREMIUM-B   2       No

Today's Tennis Court Bookings (BCNF and the weaker 3NF, which is implied by BCNF)

Member Flag     Court     Start Time   End Time
-----------     -----     ----------   --------
Yes             1         09:30        10:30
Yes             1         11:00        12:00
No              1         14:00        15:30
No              2         10:00        11:30
No              2         11:30        13:30
Yes             2         15:00        16:30

Problem Solved: Now if we upgrade the court we can guarantee the rate type will reflect this change, and we cannot charge the wrong price for a court.

(In technical terms, we can guarantee that the functional dependency "Rate Type" -> "Court" will not be violated.)

Python Pandas: Get index of rows which column matches certain value

If you want to use your dataframe object only once, use:

df['BoolCol'].loc[lambda x: x==True].index

What is a thread exit code?

what happened to me is that I have multiple projects in my solution. I meant to debug project 1, however, the project 2 was set as the default starting project. I fixed this by, right click on the project and select "Set as startup project", then running debugging is fine.

"SELECT ... IN (SELECT ...)" query in CodeIgniter

I think you can create a simple SQL query:

$sql="select username from user where id in (select id from idtables)";
$query=$this->db->query($sql);

and then you can use it normally.

How to call shell commands from Ruby

The way I like to do this is using the %x literal, which makes it easy (and readable!) to use quotes in a command, like so:

directorylist = %x[find . -name '*test.rb' | sort]

Which, in this case, will populate file list with all test files under the current directory, which you can process as expected:

directorylist.each do |filename|
  filename.chomp!
  # work with file
end

Creating a system overlay window (always on top)

Following @Sam Lu's answer, Indeed Android 4.x blocks certain types from listening to outside touch events, but some types, such as TYPE_SYSTEM_ALERT, still do the job.

Example

    WindowManager.LayoutParams params = new WindowManager.LayoutParams(
            WindowManager.LayoutParams.MATCH_PARENT,
            WindowManager.LayoutParams.MATCH_PARENT,
            WindowManager.LayoutParams.TYPE_SYSTEM_ALERT,
            WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
                    | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
                    | WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH,
            PixelFormat.TRANSLUCENT);

    WindowManager wm = (WindowManager) getSystemService(WINDOW_SERVICE);
    LayoutInflater inflater = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
    View myView = inflater.inflate(R.layout.my_view, null);
    myView.setOnTouchListener(new OnTouchListener() {
       @Override
       public boolean onTouch(View v, MotionEvent event) {
           Log.d(TAG, "touch me");
           return true;
       }
     });

    // Add layout to window manager
    wm.addView(myView, params);

Permissions

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

How to specify line breaks in a multi-line flexbox layout?

The simplest and most reliable solution is inserting flex items at the right places. If they are wide enough (width: 100%), they will force a line break.

_x000D_
_x000D_
.container {_x000D_
  background: tomato;_x000D_
  display: flex;_x000D_
  flex-flow: row wrap;_x000D_
  align-content: space-between;_x000D_
  justify-content: space-between;_x000D_
}_x000D_
.item {_x000D_
  width: 100px;_x000D_
  background: gold;_x000D_
  height: 100px;_x000D_
  border: 1px solid black;_x000D_
  font-size: 30px;_x000D_
  line-height: 100px;_x000D_
  text-align: center;_x000D_
  margin: 10px_x000D_
}_x000D_
.item:nth-child(4n - 1) {_x000D_
  background: silver;_x000D_
}_x000D_
.line-break {_x000D_
  width: 100%;_x000D_
}
_x000D_
<div class="container">_x000D_
  <div class="item">1</div>_x000D_
  <div class="item">2</div>_x000D_
  <div class="item">3</div>_x000D_
  <div class="line-break"></div>_x000D_
  <div class="item">4</div>_x000D_
  <div class="item">5</div>_x000D_
  <div class="item">6</div>_x000D_
  <div class="line-break"></div>_x000D_
  <div class="item">7</div>_x000D_
  <div class="item">8</div>_x000D_
  <div class="item">9</div>_x000D_
  <div class="line-break"></div>_x000D_
  <div class="item">10</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

But that's ugly and not semantic. Instead, we could generate pseudo-elements inside the flex container, and use order to move them to the right places.

_x000D_
_x000D_
.container {_x000D_
  background: tomato;_x000D_
  display: flex;_x000D_
  flex-flow: row wrap;_x000D_
  align-content: space-between;_x000D_
  justify-content: space-between;_x000D_
}_x000D_
.item {_x000D_
  width: 100px;_x000D_
  background: gold;_x000D_
  height: 100px;_x000D_
  border: 1px solid black;_x000D_
  font-size: 30px;_x000D_
  line-height: 100px;_x000D_
  text-align: center;_x000D_
  margin: 10px_x000D_
}_x000D_
.item:nth-child(3n) {_x000D_
  background: silver;_x000D_
}_x000D_
.container::before, .container::after {_x000D_
  content: '';_x000D_
  width: 100%;_x000D_
  order: 1;_x000D_
}_x000D_
.item:nth-child(n + 4) {_x000D_
  order: 1;_x000D_
}_x000D_
.item:nth-child(n + 7) {_x000D_
  order: 2;_x000D_
}
_x000D_
<div class="container">_x000D_
  <div class="item">1</div>_x000D_
  <div class="item">2</div>_x000D_
  <div class="item">3</div>_x000D_
  <div class="item">4</div>_x000D_
  <div class="item">5</div>_x000D_
  <div class="item">6</div>_x000D_
  <div class="item">7</div>_x000D_
  <div class="item">8</div>_x000D_
  <div class="item">9</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

But there is a limitation: the flex container can only have a ::before and a ::after pseudo-element. That means you can only force 2 line breaks.

To solve that, you can generate the pseudo-elements inside the flex items instead of in the flex container. This way you won't be limited to 2. But those pseudo-elements won't be flex items, so they won't be able to force line breaks.

But luckily, CSS Display L3 has introduced display: contents (currently only supported by Firefox 37):

The element itself does not generate any boxes, but its children and pseudo-elements still generate boxes as normal. For the purposes of box generation and layout, the element must be treated as if it had been replaced with its children and pseudo-elements in the document tree.

So you can apply display: contents to the children of the flex container, and wrap the contents of each one inside an additional wrapper. Then, the flex items will be those additional wrappers and the pseudo-elements of the children.

_x000D_
_x000D_
.container {_x000D_
  background: tomato;_x000D_
  display: flex;_x000D_
  flex-flow: row wrap;_x000D_
  align-content: space-between;_x000D_
  justify-content: space-between;_x000D_
}_x000D_
.item {_x000D_
  display: contents;_x000D_
}_x000D_
.item > div {_x000D_
  width: 100px;_x000D_
  background: gold;_x000D_
  height: 100px;_x000D_
  border: 1px solid black;_x000D_
  font-size: 30px;_x000D_
  line-height: 100px;_x000D_
  text-align: center;_x000D_
  margin: 10px;_x000D_
}_x000D_
.item:nth-child(3n) > div {_x000D_
  background: silver;_x000D_
}_x000D_
.item:nth-child(3n)::after {_x000D_
  content: '';_x000D_
  width: 100%;_x000D_
}
_x000D_
<div class="container">_x000D_
  <div class="item"><div>1</div></div>_x000D_
  <div class="item"><div>2</div></div>_x000D_
  <div class="item"><div>3</div></div>_x000D_
  <div class="item"><div>4</div></div>_x000D_
  <div class="item"><div>5</div></div>_x000D_
  <div class="item"><div>6</div></div>_x000D_
  <div class="item"><div>7</div></div>_x000D_
  <div class="item"><div>8</div></div>_x000D_
  <div class="item"><div>9</div></div>_x000D_
  <div class="item"><div>10</div></div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Alternatively, according to Fragmenting Flex Layout and CSS Fragmentation, Flexbox allows forced breaks by using break-before, break-after or their CSS 2.1 aliases:

.item:nth-child(3n) {
  page-break-after: always; /* CSS 2.1 syntax */
  break-after: always; /* New syntax */
}

_x000D_
_x000D_
.container {_x000D_
  background: tomato;_x000D_
  display: flex;_x000D_
  flex-flow: row wrap;_x000D_
  align-content: space-between;_x000D_
  justify-content: space-between;_x000D_
}_x000D_
.item {_x000D_
  width: 100px;_x000D_
  background: gold;_x000D_
  height: 100px;_x000D_
  border: 1px solid black;_x000D_
  font-size: 30px;_x000D_
  line-height: 100px;_x000D_
  text-align: center;_x000D_
  margin: 10px_x000D_
}_x000D_
.item:nth-child(3n) {_x000D_
  page-break-after: always;_x000D_
  background: silver;_x000D_
}
_x000D_
<div class="container">_x000D_
  <div class="item">1</div>_x000D_
  <div class="item">2</div>_x000D_
  <div class="item">3</div>_x000D_
  <div class="item">4</div>_x000D_
  <div class="item">5</div>_x000D_
  <div class="item">6</div>_x000D_
  <div class="item">7</div>_x000D_
  <div class="item">8</div>_x000D_
  <div class="item">9</div>_x000D_
  <div class="item">10</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Forced line breaks in flexbox are not widely supported yet, but it works on Firefox.

How to reset Jenkins security settings from the command line?

In El-Capitan config.xml can not be found at

/var/lib/jenkins/

Its available in

~/.jenkins

then after that as other mentioned open the config.xml file and make the following changes

  • In this replace <useSecurity>true</useSecurity> with <useSecurity>false</useSecurity>

  • Remove <authorizationStrategy> and <securityRealm>

  • Save it and restart the jenkins(sudo service jenkins restart)

SDK Manager.exe doesn't work

Similar to sixty9 I renamed java.exe, javaw.exe, javaws.exe (I never delete files when troubleshooting) after I created a JAVA_HOME environment variable and added path variables.

I had installed the Java SDK on my D:\ drive ( instead of the default).

  1. Create a JAVA_HOME variable: Variable Name: %JAVA_HOME% Value: D:\Program Files\Java.

  2. Added the following to the Path variable:

    %JAVA_HOME%\jre7\bin;%JAVA_HOME%\jdk1.7.0_03\bin;
    
  3. Renamed java.exe, javaw.exe and javaws.exe.

  4. Restarted the system and the Android SDK installer found my JDK and installed successfully.

Why is a primary-foreign key relation required when we can join without it?

I know its late to post, but I use the site for my own reference and so I wanted to put an answer here for myself to reference in the future too. I hope you (and others) find it helpful.

Lets pretend a bunch of super Einstein experts designed our database. Our super perfect database has 3 tables, and the following relationships defined between them:

TblA 1:M TblB
TblB 1:M TblC

Notice there is no relationship between TblA and TblC

In most scenarios such a simple database is easy to navigate but in commercial databases it is usually impossible to be able to tell at the design stage all the possible uses and combination of uses for data, tables, and even whole databases, especially as systems get built upon and other systems get integrated or switched around or out. This simple fact has spawned a whole industry built on top of databases called Business Intelligence. But I digress...

In the above case, the structure is so simple to understand that its easy to see you can join from TblA, through to B, and through to C and vice versa to get at what you need. It also very vaguely highlights some of the problems with doing it. Now expand this simple chain to 10 or 20 or 50 relationships long. Now all of a sudden you start to envision a need for exactly your scenario. In simple terms, a join from A to C or vice versa or A to F or B to Z or whatever as our system grows.

There are many ways this can indeed be done. The one mentioned above being the most popular, that is driving through all the links. The major problem is that its very slow. And gets progressively slower the more tables you add to the chain, the more those tables grow, and the further you want to go through it.

Solution 1: Look for a common link. It must be there if you taught of a reason to join A to C. If it is not obvious, create a relationship and then join on it. i.e. To join A through B through C there must be some commonality or your join would either produce zero results or a massive number or results (Cartesian product). If you know this commonality, simply add the needed columns to A and C and link them directly.

The rule for relationships is that they simply must have a reason to exist. Nothing more. If you can find a good reason to link from A to C then do it. But you must ensure your reason is not redundant (i.e. its already handled in some other way).

Now a word of warning. There are some pitfalls. But I don't do a good job of explaining them so I will refer you to my source instead of talking about it here. But remember, this is getting into some heavy stuff, so this video about fan and chasm traps is really only a starting point. You can join without relationships. But I advise watching this video first as this goes beyond what most people learn in college and well into the territory of the BI and SAP guys. These guys, while they can program, their day job is to specialise in exactly this kind of thing. How to get massive amounts of data to talk to each other and make sense.

This video is one of the better videos I have come across on the subject. And it's worth looking over some of his other videos. I learned a lot from him.

Linq select objects in list where exists IN (A,B,C)

Try with Contains function;

Determines whether a sequence contains a specified element.

var allowedStatus = new[]{ "A", "B", "C" };
var filteredOrders = orders.Order.Where(o => allowedStatus.Contains(o.StatusCode));

Is it possible to append to innerHTML without destroying descendants' event listeners?

I created my markup to insert as a string since it's less code and easier to read than working with the fancy dom stuff.

Then I made it innerHTML of a temporary element just so I could take the one and only child of that element and attach to the body.

var html = '<div>';
html += 'Hello div!';
html += '</div>';

var tempElement = document.createElement('div');
tempElement.innerHTML = html;
document.getElementsByTagName('body')[0].appendChild(tempElement.firstChild);

Input type for HTML form for integer

Prior to HTML5, input type="text" simply means a field to insert free text, regardless of what you want it be. that is the job of validations you would have to do in order to guarantee the user enters a valid number

If you're using HTML5, you can use the new input types, one of which is number that automatically validates the text input, and forces it to be a number

keep in mind though, that if you're building a server side app (php for example) you will still have to validate the input on that side (make sure it is really a number) since it's pretty easy to hack the html and change the input type, removing the browser validation

Replacing NULL and empty string within Select statement

Sounds like you want a view instead of altering actual table data.

Coalesce(NullIf(rtrim(Address.Country),''),'United States')

This will force your column to be null if it is actually an empty string (or blank string) and then the coalesce will have a null to work with.

How do you check if a string is not equal to an object or other string value in java?

you'll want to use && to see that it is not equal to "AM" AND not equal to "PM"

if(!TimeOfDayStringQ.equals("AM") && !TimeOfDayStringQ.equals("PM")) {
    System.out.println("Sorry, incorrect input.");
    System.exit(1);
}

to be clear you can also do

if(!(TimeOfDayStringQ.equals("AM") || TimeOfDayStringQ.equals("PM"))){
    System.out.println("Sorry, incorrect input.");
    System.exit(1);
}

to have the not (one or the other) phrase in the code (remember the (silent) brackets)

How do I make a text go onto the next line if it overflows?

word-wrap: break-word; 

add this to your container that should do the trick

Execution failed for task ':app:processDebugResources' even with latest build tools

as a quick fix to this question, make sure your compile Sdk verion, your buildtoolsversion, your appcompat, and finally your support library are all running on the same sdk version, for further clarity take a look at the image i just uploaded. Cheers. Follow the red annotations and get rid of that trouble.

enter image description here

String contains - ignore case

You can use

org.apache.commons.lang3.StringUtils.containsIgnoreCase(CharSequence str,
                                     CharSequence searchStr);

Checks if CharSequence contains a search CharSequence irrespective of case, handling null. Case-insensitivity is defined as by String.equalsIgnoreCase(String).

A null CharSequence will return false.

This one will be better than regex as regex is always expensive in terms of performance.

For official doc, refer to : StringUtils.containsIgnoreCase

Update :

If you are among the ones who

  • don't want to use Apache commons library
  • don't want to go with the expensive regex/Pattern based solutions,
  • don't want to create additional string object by using toLowerCase,

you can implement your own custom containsIgnoreCase using java.lang.String.regionMatches

public boolean regionMatches(boolean ignoreCase,
                             int toffset,
                             String other,
                             int ooffset,
                             int len)

ignoreCase : if true, ignores case when comparing characters.

public static boolean containsIgnoreCase(String str, String searchStr)     {
    if(str == null || searchStr == null) return false;

    final int length = searchStr.length();
    if (length == 0)
        return true;

    for (int i = str.length() - length; i >= 0; i--) {
        if (str.regionMatches(true, i, searchStr, 0, length))
            return true;
    }
    return false;
}

Return 0 if field is null in MySQL

You can use coalesce(column_name,0) instead of just column_name. The coalesce function returns the first non-NULL value in the list.

I should mention that per-row functions like this are usually problematic for scalability. If you think your database may get to be a decent size, it's often better to use extra columns and triggers to move the cost from the select to the insert/update.

This amortises the cost assuming your database is read more often than written (and most of them are).

Why do you create a View in a database?

I think first one .To hide the complexity of Query. Its very appropriate for views .How when we normalize Database tables increases.Now to fetch data is very difficult when number of tables increases.So best way to handle is follow views.If i am wrong correct me.

Posting array from form

You're already doing that, as a matter of fact. When the form is submitted, the data is passed through a post array ($_POST). Your process.php is receiving that array and redistributing its values as individual variables.

Is there a CSS selector for text nodes?

Text nodes cannot have margins or any other style applied to them, so anything you need style applied to must be in an element. If you want some of the text inside of your element to be styled differently, wrap it in a span or div, for example.

Detect if the app was launched/opened from a push notification

For swift:

func application(application: UIApplication, didReceiveRemoteNotification userInfo: [NSObject : AnyObject]) {
    PFPush.handlePush(userInfo)

    if application.applicationState == UIApplicationState.Inactive || application.applicationState == UIApplicationState.Background {
        //opened from a push notification when the app was in the background

    }

}

How do I declare an array of undefined or no initial size?

Modern C, aka C99, has variable length arrays, VLA. Unfortunately, not all compilers support this but if yours does this would be an alternative.

Accessing MVC's model property from Javascript

try this: (you missed the single quotes)

var floorplanSettings = '@Html.Raw(Json.Encode(Model.FloorPlanSettings))';

How to overwrite files with Copy-Item in PowerShell

How about calling the .NET Framework methods?

You can do ANYTHING with them... :

[System.IO.File]::Copy($src, $dest, $true);

The $true argument makes it overwrite.

Parsing JSON Array within JSON Object

line 2 should be

for (int i = 0; i < jsonMainArr.size(); i++) {  // **line 2**

For line 3, I'm having to do

    JSONObject childJSONObject = (JSONObject) new JSONParser().parse(jsonMainArr.get(i).toString());

How do I upload a file to an SFTP server in C# (.NET)?

Maybe you can script/control winscp?

Update: winscp now has a .NET library available as a nuget package that supports SFTP, SCP, and FTPS

HTML Upload MAX_FILE_SIZE does not appear to work

There IS A POINT in introducing MAX_FILE_SIZE client side hidden form field.

php.ini can limit uploaded file size. So, while your script honors the limit imposed by php.ini, different HTML forms can further limit an uploaded file size. So, when uploading video, form may limit* maximum size to 10MB, and while uploading photos, forms may put a limit of just 1mb. And at the same time, the maximum limit can be set in php.ini to suppose 10mb to allow all this.

Although this is not a fool proof way of telling the server what to do, yet it can be helpful.

  • HTML does'nt limit anything. It just forwards the server all form variable including MAX_FILE_SIZE and its value.

Hope it helped someone.

Adding a new value to an existing ENUM Type

just in case, if you are using Rails and you have several statements you will need to execute one by one, like:

execute "ALTER TYPE XXX ADD VALUE IF NOT EXISTS 'YYY';"
execute "ALTER TYPE XXX ADD VALUE IF NOT EXISTS 'ZZZ';"

GnuPG: "decryption failed: secret key not available" error from gpg on Windows

when reimporting your keys from the old keyring, you need to specify the command:

gpg --allow-secret-key-import --import <keyring>

otherwise it will only import the public keys, not the private keys.

Java - Check if JTextField is empty or not

private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    // Submit Button        

    String Fname = jTextField1.getText();
    String Lname = jTextField2.getText();
    String Desig = jTextField3.getText();
    String Nic = jTextField4.getText();
    String Phone = jTextField5.getText();
    String Add = jTextArea1.getText();
    String Dob = jTextField6.getText();
    // String Gender;
    // Image

    if (Fname.hashCode() == 0 || Lname.hashCode() == 0 || Desig.hashCode() == 0 || Nic.hashCode() == 0 || Phone.hashCode() == 0 || Add.hashCode() == 0)
    {
        JOptionPane.showMessageDialog(null, "Some fields are empty!");
    }
    else
    {
        JOptionPane.showMessageDialog(null, "OK");
    }
}

How can I show a hidden div when a select option is selected?

Check this code. It awesome code for hide div using select item.

HTML

<select name="name" id="cboOptions" onchange="showDiv('div',this)" class="form-control" >
    <option value="1">YES</option>
    <option value="2">NO</option>
</select>

<div id="div1" style="display:block;">
    <input type="text" id="customerName" class="form-control" placeholder="Type Customer Name...">
    <input type="text" style="margin-top: 3px;" id="customerAddress" class="form-control" placeholder="Type Customer Address...">
    <input type="text" style="margin-top: 3px;" id="customerMobile" class="form-control" placeholder="Type Customer Mobile...">
</div>
<div id="div2" style="display:none;">
    <input type="text" list="cars" id="customerID" class="form-control" placeholder="Type Customer Name...">
    <datalist id="cars">
        <option>Value 1</option>
        <option>Value 2</option>
        <option>Value 3</option>
        <option>Value 4</option>
    </datalist>
</div>

JS

<script>
    function showDiv(prefix,chooser) 
    {
            for(var i=0;i<chooser.options.length;i++) 
            {
                var div = document.getElementById(prefix+chooser.options[i].value);
                div.style.display = 'none';
            }

            var selectedOption = (chooser.options[chooser.selectedIndex].value);

            if(selectedOption == "1")
            {
                displayDiv(prefix,"1");
            }
            if(selectedOption == "2")
            {
                displayDiv(prefix,"2");
            }
    }

    function displayDiv(prefix,suffix) 
    {
            var div = document.getElementById(prefix+suffix);
            div.style.display = 'block';
    }
</script>

Regex: Use start of line/end of line signs (^ or $) in different context

You can't use ^ and $ in character classes in the way you wish - they will be interpreted literally, but you can use an alternation to achieve the same effect:

(^|,)garp(,|$)

CSS align images and text on same line

You can either use (on the h4 elements, as they are block by default)

display: inline-block;

Or you can float the elements to the left/rght

float: left;

Just don't forget to clear the floats after

clear: left;

More visual example for the float left/right option as shared below by @VSB:

_x000D_
_x000D_
<h4> _x000D_
    <div style="float:left;">Left Text</div>_x000D_
    <div style="float:right;">Right Text</div>_x000D_
    <div style="clear: left;"/>_x000D_
</h4>
_x000D_
_x000D_
_x000D_

Which comes first in a 2D array, rows or columns?

All depends on your visualization of the array. Rows and Columns are properties of visualization (probably in your imagination) of the array, not the array itself.

It's exactly the same as asking is number "5" red or green?

I could draw it red, I could draw it greed right? Color is not an integral property of a number. In the same way representing 2D array as a grid of rows and columns is not necessary for existence of this array.

2D array has just first dimention and second dimention, everything related to visualizing those is purely your flavour.

When I have char array char[80][25], I may like to print it on console rotated so that I have 25 rows of 80 characters that fits the screen without scroll.

I'll try to provide viable example when representing 2D array as rows and columns doesn't make sense at all: Let's say I need an array of 1 000 000 000 integers. My machine has 8GB of RAM, so I have enough memory for this, but if you try executing var a = new int[1000000000], you'll most likely get OutOfMemory exception. That's because of memory fragmentation - there is no consecutive block of memory of this size. Instead you you can create 2D array 10 000 x 100 000 with your values. Logically it is 1D array, so you'd like to draw and imagine it as a single sequence of values, but due to technical implementation it is 2D.

How can I capture the right-click event in JavaScript?

Use the oncontextmenu event.

Here's an example:

<div oncontextmenu="javascript:alert('success!');return false;">
    Lorem Ipsum
</div>

And using event listeners (credit to rampion from a comment in 2011):

el.addEventListener('contextmenu', function(ev) {
    ev.preventDefault();
    alert('success!');
    return false;
}, false);

Don't forget to return false, otherwise the standard context menu will still pop up.

If you are going to use a function you've written rather than javascript:alert("Success!"), remember to return false in BOTH the function AND the oncontextmenu attribute.

ORDER BY items must appear in the select list if SELECT DISTINCT is specified

Try one of these:

  1. Use column alias:

    ORDER BY RadioServiceCodeId,RadioService

  2. Use column position:

    ORDER BY 1,2

You can only order by columns that actually appear in the result of the DISTINCT query - the underlying data isn't available for ordering on.

Where is the user's Subversion config file stored on the major operating systems?

@Baxter's is mostly correct but it is missing one important Windows-specific detail.

Subversion's runtime configuration area is stored in the %APPDATA%\Subversion\ directory. The files are config and servers.

However, in addition to text-based configuration files, Subversion clients can use Windows Registry to store the client settings. It makes it possible to modify the settings with PowerShell in a convenient manner, and also distribute these settings to user workstations in Active Directory environment via AD Group Policy. See SVNBook | Configuration and the Windows Registry (you can find examples and a sample *.reg file there).

enter image description here

Converting dictionary to JSON

Defining r as a dictionary should do the trick:

>>> r: dict = {'is_claimed': 'True', 'rating': 3.5}
>>> print(r['rating'])
3.5
>>> type(r)
<class 'dict'>

How does Django's Meta class work?

Django's Model class specifically handles having an attribute named Meta which is a class. It's not a general Python thing.

Python metaclasses are completely different.

Convert List<String> to List<Integer> directly

Using lambda:

strList.stream().map(org.apache.commons.lang3.math.NumberUtils::toInt).collect(Collectors.toList());

"You may need an appropriate loader to handle this file type" with Webpack and Babel

Due to updates and changes overtime, version compatibility start causing issues with configuration.

Your webpack.config.js should be like this you can also configure how ever you dim fit.

var path = require('path');
var webpack = require("webpack");

module.exports = {
  entry: './src/js/app.js',
  devtool: 'source-map',
    mode: 'development',
  module: {
    rules: [{
      test: /\.js$/,
      exclude: /node_modules/,
      use: ["babel-loader"]
    },{
      test: /\.css$/,
      use: ['style-loader', 'css-loader']
    }]
  },
  output: {
    path: path.resolve(__dirname, './src/vendor'),
    filename: 'bundle.min.js'
  }
};

Another Thing to notice it's the change of args, you should read babel documentation https://babeljs.io/docs/en/presets

.babelrc

{
    "presets": ["@babel/preset-env", "@babel/preset-react"]
}

NB: you have to make sure you have the above @babel/preset-env & @babel/preset-react installed in your package.json dependencies

Simple and clean way to convert JSON string to Object in Swift

You can use swift.quicktype.io for converting JSON to either struct or class. Even you can mention version of swift to genrate code.

Example JSON:

{
  "message": "Hello, World!"
}

Generated code:

import Foundation

typealias Sample = OtherSample

struct OtherSample: Codable {
    let message: String
}

// Serialization extensions

extension OtherSample {
    static func from(json: String, using encoding: String.Encoding = .utf8) -> OtherSample? {
        guard let data = json.data(using: encoding) else { return nil }
        return OtherSample.from(data: data)
    }

    static func from(data: Data) -> OtherSample? {
        let decoder = JSONDecoder()
        return try? decoder.decode(OtherSample.self, from: data)
    }

    var jsonData: Data? {
        let encoder = JSONEncoder()
        return try? encoder.encode(self)
    }

    var jsonString: String? {
        guard let data = self.jsonData else { return nil }
        return String(data: data, encoding: .utf8)
    }
}

extension OtherSample {
    enum CodingKeys: String, CodingKey {
        case message
    }
}

Global variables in R

What about .GlobalEnv$a <- "new" ? I saw this explicit way of creating a variable in a certain environment here: http://adv-r.had.co.nz/Environments.html. It seems shorter than using the assign() function.

Return multiple values from a function, sub or type?

Ideas :

  1. Use pass by reference (ByRef)
  2. Build a User Defined Type to hold the stuff you want to return, and return that.
  3. Similar to 2 - build a class to represent the information returned, and return objects of that class...

Best practice multi language website

A really simple option that works with any website where you can upload Javascript is www.multilingualizer.com

It lets you put all text for all languages onto one page and then hides the languages the user doesn't need to see. Works well.

Set the layout weight of a TextView programmatically

The answer is that you have to use TableRow.LayoutParams, not LinearLayout.LayoutParams or any other LayoutParams.

TextView tv = new TextView(v.getContext());
LayoutParams params = new TableRow.LayoutParams(0, LayoutParams.WRAP_CONTENT, 1f);
tv.setLayoutParams(params);

The different LayoutParams are not interchangeable and if you use the wrong one then nothing seems to happen. The text view's parent is a table row, hence:

http://developer.android.com/reference/android/widget/TableRow.LayoutParams.html

Dynamically add script tag with src that may include document.write

Well, there are multiple ways you can include dynamic javascript, I use this one for many of the projects.

var script = document.createElement("script")
script.type = "text/javascript";
//Chrome,Firefox, Opera, Safari 3+
script.onload = function(){
console.log("Script is loaded");
};
script.src = "file1.js";
document.getElementsByTagName("head")[0].appendChild(script);

You can call create a universal function which can help you to load as many javascript files as needed. There is a full tutorial about this here.

Inserting Dynamic Javascript the right way

Align two divs horizontally side by side center to the page using bootstrap css

I recommend css grid over bootstrap if what you really want, is to have more structured data, e.g. a side by side table with multiple rows, because you don't have to add class name for every child:

// css-grid: https://www.w3schools.com/css/tryit.asp?filename=trycss_grid
// https://css-tricks.com/snippets/css/complete-guide-grid/
.grid-container {
  display: grid;
  grid-template-columns: auto auto; // 20vw 40vw for me because I have dt and dd
  padding: 10px;
  text-align: left;
  justify-content: center;
  align-items: center;
}

.grid-container > div {
  padding: 20px;
}


<div class="grid-container">
  <div>1</div>
  <div>2</div>
  <div>3</div>
  <div>4</div>
  <div>5</div>
  <div>6</div>
  <div>7</div>
  <div>8</div>
</div>

css-grid

Angular window resize event

@Günter's answer is correct. I just wanted to propose yet another method.

You could also add the host-binding inside the @Component()-decorator. You can put the event and desired function call in the host-metadata-property like so:

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css'],
  host: {
    '(window:resize)': 'onResize($event)'
  }
})
export class AppComponent{
   onResize(event){
     event.target.innerWidth; // window width
   }
}

Error 415 Unsupported Media Type: POST not reaching REST if JSON, but it does if XML

If none of the solution worked and you are working with JAXB, then you need to annotate your class with @XmlRootElement to avoid 415 unsupported media type

Unused arguments in R

You could use dots: ... in your function definition.

myfun <- function(a, b, ...){
  cat(a,b)
}

myfun(a=4,b=7,hello=3)

# 4 7

How to set up java logging using a properties file? (java.util.logging)

Logger log = Logger.getLogger("myApp");
log.setLevel(Level.ALL);
log.info("initializing - trying to load configuration file ...");

//Properties preferences = new Properties();
try {
    //FileInputStream configFile = new //FileInputStream("/path/to/app.properties");
    //preferences.load(configFile);
    InputStream configFile = myApp.class.getResourceAsStream("app.properties");
    LogManager.getLogManager().readConfiguration(configFile);
} catch (IOException ex)
{
    System.out.println("WARNING: Could not open configuration file");
    System.out.println("WARNING: Logging not configured (console output only)");
}
log.info("starting myApp");

this is working..:) you have to pass InputStream in readConfiguration().

How to set TextView textStyle such as bold, italic

Programmatically:

You can do programmatically using setTypeface() method:

Below is the code for default Typeface

textView.setTypeface(null, Typeface.NORMAL);      // for Normal Text
textView.setTypeface(null, Typeface.BOLD);        // for Bold only
textView.setTypeface(null, Typeface.ITALIC);      // for Italic
textView.setTypeface(null, Typeface.BOLD_ITALIC); // for Bold and Italic

and if you want to set custom Typeface:

textView.setTypeface(textView.getTypeface(), Typeface.NORMAL);      // for Normal Text
textView.setTypeface(textView.getTypeface(), Typeface.BOLD);        // for Bold only
textView.setTypeface(textView.getTypeface(), Typeface.ITALIC);      // for Italic
textView.setTypeface(textView.getTypeface(), Typeface.BOLD_ITALIC); // for Bold and Italic

XML:

You can set directly in XML file in <TextView /> like this:

android:textStyle="normal"
android:textStyle="normal|bold"
android:textStyle="normal|italic"
android:textStyle="bold"
android:textStyle="bold|italic"

Or you can set your fav font (from assets). for more info see link

How can I apply styles to multiple classes at once?

You can have multiple CSS declarations for the same properties by separating them with commas:

.abc, .xyz {
   margin-left: 20px;
}

Reasons for using the set.seed function

You have to set seed every time you want to get a reproducible random result.

set.seed(1)
rnorm(4)
set.seed(1)
rnorm(4)

How to detect escape key press with pure JS or jQuery?

pure JS (no JQuery)

document.addEventListener('keydown', function(e) {
    if(e.keyCode == 27){
      //add your code here
    }
});

SQL Server Regular expressions in T-SQL

If you are using SQL Server 2016 or above, you can use sp_execute_external_script along with R. It has functions for Regular Expression searches, such as grep and grepl.

Here's an example for email addresses. I'll query some "people" via the SQL Server database engine, pass the data for those people to R, let R decide which people have invalid email addresses, and have R pass back that subset of people to SQL Server. The "people" are from the [Application].[People] table in the [WideWorldImporters] sample database. They get passed to the R engine as a dataframe named InputDataSet. R uses the grepl function with the "not" operator (exclamation point!) to find which people have email addresses that don't match the RegEx string search pattern.

EXEC sp_execute_external_script 
 @language = N'R',
 @script = N' RegexWithR <- InputDataSet;
OutputDataSet <- RegexWithR[!grepl("([_a-z0-9-]+(\\.[_a-z0-9-]+)*@[a-z0-9-]+(\\.[a-z0-9-]+)*(\\.[a-z]{2,4}))", RegexWithR$EmailAddress), ];',
 @input_data_1 = N'SELECT PersonID, FullName, EmailAddress FROM Application.People'
 WITH RESULT SETS (([PersonID] INT, [FullName] NVARCHAR(50), [EmailAddress] NVARCHAR(256)))

Note that the appropriate features must be installed on the SQL Server host. For SQL Server 2016, it is called "SQL Server R Services". For SQL Server 2017, it was renamed to "SQL Server Machine Learning Services".

Closing Thoughts Microsoft's implementation of SQL (T-SQL) doesn't have native support for RegEx. This proposed solution may not be any more desirable to the OP than the use of a CLR stored procedure. But it does offer an additional way to approach the problem.

Instantiating a generic class in Java

I really need to instantiate a T in Foo using a parameter-less constructor

Simple answer is "you cant do that" java uses type erasure to implment generics which would prevent you from doing this.

How can one work around Java's limitation?

One way (there could be others) is to pass the object that you would pass the instance of T to the constructor of Foo<T>. Or you could have a method setBar(T theInstanceofT); to get your T instead of instantiating in the class it self.

How to hide a TemplateField column in a GridView

GridView1.Columns[columnIndex].Visible = false;

Faster alternative in Oracle to SELECT COUNT(*) FROM sometable

You can have better performance by using the following method:

SELECT COUNT(1) FROM (SELECT /*+FIRST_ROWS*/ column_name 
FROM table_name 
WHERE column_name = 'xxxxx' AND ROWNUM = 1);

how to use free cloud database with android app?

Now there are a lot of cloud providers , providing solutions like MBaaS (Mobile Backend as a Service). Some only give access to cloud database, some will do the user management for you, some let you place code around cloud database and there are facilities of access control, push notifications, analytics, integrated image and file hosting etc.

Here are some providers which have a "free-tier" (may change in future):

  1. Firebase (Google) - https://firebase.google.com/
  2. AWS Mobile (Amazon) - https://aws.amazon.com/mobile/
  3. Azure Mobile (Microsoft) - https://azure.microsoft.com/en-in/services/app-service/mobile/
  4. MongoDB Realm (MongoDB) - https://www.mongodb.com/realm
  5. Back4app (Popular) - https://www.back4app.com/

Open source solutions:

  1. Parse - http://parseplatform.org/
  2. Apache User Grid - https://usergrid.apache.org/
  3. SupaBase (under development) - https://supabase.io/

Inline for loop

you can use enumerate keeping the ind/index of the elements is in vm, if you make vm a set you will also have 0(1) lookups:

vm = {-1, -1, -1, -1}

print([ind if q in vm else 9999 for ind,ele in enumerate(vm) ])

PHP convert XML to JSON

If you would like to only convert a specific part of the XML to JSON, you can use XPath to retrieve this and convert that to JSON.

<?php
$file = @file_get_contents($xml_File, FILE_TEXT);
$xml = new SimpleXMLElement($file);
$xml_Excerpt = @$xml->xpath('/states/state[@id="AL"]')[0]; // [0] gets the node
echo json_encode($xml_Excerpt);
?>

Please note that if you Xpath is incorrect, this will die with an error. So if you're debugging this through AJAX calls I recommend you log the response bodies as well.

How to iterate over arguments in a Bash script

Note that Robert's answer is correct, and it works in sh as well. You can (portably) simplify it even further:

for i in "$@"

is equivalent to:

for i

I.e., you don't need anything!

Testing ($ is command prompt):

$ set a b "spaces here" d
$ for i; do echo "$i"; done
a
b
spaces here
d
$ for i in "$@"; do echo "$i"; done
a
b
spaces here
d

I first read about this in Unix Programming Environment by Kernighan and Pike.

In bash, help for documents this:

for NAME [in WORDS ... ;] do COMMANDS; done

If 'in WORDS ...;' is not present, then 'in "$@"' is assumed.

Should you use .htm or .html file extension? What is the difference, and which file is correct?

.html - DOS has been dead for a long time. But it doesn't really make much difference in the end.

How can you find out which process is listening on a TCP or UDP port on Windows?

Follow these tools: From cmd: C:\> netstat -anob with Administrator privileges.

Process Explorer

Process Dump

Port Monitor

All from sysinternals.com.

If you just want to know process running and threads under each process, I recommend learning about wmic. It is a wonderful command-line tool, which gives you much more than you can know.

Example:

c:\> wmic process list brief /every:5

The above command will show an all process list in brief every 5 seconds. To know more, you can just go with /? command of windows , for example,

c:\> wmic /?
c:\> wmic process /?
c:\> wmic prcess list /?

And so on and so forth. :)

How do I find the authoritative name-server for a domain name?

You can use the whois service. On a UNIX like operating system you would execute the following command. Alternatively you can do it on the web at http://www.internic.net/whois.html.

whois stackoverflow.com

You would get the following response.

...text removed here...

Domain servers in listed order: NS51.DOMAINCONTROL.COM NS52.DOMAINCONTROL.COM

You can use nslookup or dig to find out more information about records for a given domain. This might help you resolve the conflicts you have described.

How to write "not in ()" sql query using join

This article:

may be if interest to you.

In a couple of words, this query:

SELECT  d1.short_code
FROM    domain1 d1
LEFT JOIN
        domain2 d2
ON      d2.short_code = d1.short_code
WHERE   d2.short_code IS NULL

will work but it is less efficient than a NOT NULL (or NOT EXISTS) construct.

You can also use this:

SELECT  short_code
FROM    domain1
EXCEPT
SELECT  short_code
FROM    domain2

This is using neither NOT IN nor WHERE (and even no joins!), but this will remove all duplicates on domain1.short_code if any.

Angular 4 HttpClient Query Parameters

search property of type URLSearchParams in RequestOptions class is deprecated in angular 4. Instead, you should use params property of type URLSearchParams.

append multiple values for one key in a dictionary

d = {} 

# import list of year,value pairs

for year,value in mylist:
    try:
        d[year].append(value)
    except KeyError:
        d[year] = [value]

The Python way - it is easier to receive forgiveness than ask permission!

What does an exclamation mark mean in the Swift language?

Here are some examples:

var name:String = "Hello World"
var word:String?

Where word is an optional value. means it may or may not contain a value.

word = name 

Here name has a value so we can assign it

var cow:String = nil
var dog:String!

Where dog is forcefully unwrapped means it must contain a value

dog = cow

The application will crash because we are assign nil to unwrapped

"The given path's format is not supported."

I see that the originator found out that the error occurred when trying to save the filename with an entire path. Actually it's enough to have a ":" in the file name to get this error. If there might be ":" in your file name (for instance if you have a date stamp in your file name) make sure you replace these with something else. I.e:

string fullFileName = fileName.Split('.')[0] + "(" + DateTime.Now.ToString().Replace(':', '-') + ")." + fileName.Split('.')[1];

Svn switch from trunk to branch

In my case, I wanted to check out a new branch that has cut recently but it's it big in size and I want to save time and internet bandwidth, as I'm in a slow metered network

so I copped the previous branch that I already checked in

I went to the working directory, and from svn info, I can see it's on the previous branch I did the following command (you can find this command from svn switch --help)

svn switch ^/branches/newBranchName

go check svn info again you can see it is becoming the newBranchName go ahead and svn up

and this how I got the new branch easily, quickly with minimum data transmitting over the internet

hope sharing my case helps and speeds up your work

Pass values of checkBox to controller action in asp.net mvc4

 public ActionResult Save(Director director)
        {
          // IsActive my model property same name give in cshtml
//IsActive <input type="checkbox" id="IsActive" checked="checked" value="true" name="IsActive" 
            if(ModelState.IsValid)
            {
                DirectorVM ODirectorVM = new DirectorVM();
                ODirectorVM.SaveData(director);
                return RedirectToAction("Display");
            }
            return RedirectToAction("Add");
        }

Saving a Excel File into .txt format without quotes

I have the same problem: I have to make a specific .txt file for bank payments out of an excel file. The .txt file must not be delimeted by any character, because the standard requires a certain number of commas after each mandatory field. The easiest way of doing it is to copy the contect of the excel file and paste it in notepad.

The 'json' native gem requires installed build tools

My gem version 2.0.3 and I was getting the same issue. This command resolved it:

gem install json --platform=ruby --verbose

CSS z-index not working (position absolute)

Just add the second .absolute div before the other .second div:

<div class="absolute" style="top: 54px"></div>
<div class="absolute">
    <div id="relative"></div>
</div>

Because the two elements have an index 0.

Is it possible to compile a program written in Python?

You dont have to compile it. the first you use it (import) it is compiled by the CPython interpreter. But if you really want to compile there are several options.

To compile to exe

Or 2 compile just a specific *.py file, you can just use

import py_compile
py_compile.compile("yourpythoncode.py")

JavaScript replace \n with <br />

You need the /g for global matching

replace(/\n/g, "<br />");

This works for me for \n - see this answer if you might have \r\n

NOTE: The dupe is the most complete answer for any combination of \r\n, \r or \n

_x000D_
_x000D_
var messagetoSend = document.getElementById('x').value.replace(/\n/g, "<br />");_x000D_
console.log(messagetoSend);
_x000D_
<textarea id="x" rows="9">_x000D_
    Line 1_x000D_
    _x000D_
    _x000D_
    Line 2_x000D_
    _x000D_
    _x000D_
    _x000D_
    _x000D_
    Line 3_x000D_
</textarea>
_x000D_
_x000D_
_x000D_

UPDATE

It seems some visitors of this question have text with the breaklines escaped as

some text\r\nover more than one line"

In that case you need to escape the slashes:

replace(/\\r\\n/g, "<br />");

NOTE: All browsers will ignore \r in a string when rendering.

Using Linq select list inside list

list.Where(m => m.application == "applicationName" && 
           m.users.Any(u => u.surname=="surname"));

if you want to filter users as TimSchmelter commented, you can use

list.Where(m => m.application == "applicationName")
    .Select(m => new Model
    {
        application = m.application,
        users = m.users.Where(u => u.surname=="surname").ToList()
    });

Can't access to HttpContext.Current

Adding a bit to mitigate the confusion here. Even though Darren Davies' (accepted) answer is more straight forward, I think Andrei's answer is a better approach for MVC applications.

The answer from Andrei means that you can use HttpContext just as you would use System.Web.HttpContext.Current. For example, if you want to do this:

System.Web.HttpContext.Current.User.Identity.Name

you should instead do this:

HttpContext.User.Identity.Name

Both achieve the same result, but (again) in terms of MVC, the latter is more recommended.

Another good and also straight forward information regarding this matter can be found here: Difference between HttpContext.Current and Controller.Context in MVC ASP.NET.

Python function as a function argument?

  1. Yes, it's allowed.
  2. You use the function as you would any other: anotherfunc(*extraArgs)

How do I do base64 encoding on iOS?

This is a good use case for Objective C categories.

For Base64 encoding:

#import <Foundation/NSString.h>

@interface NSString (NSStringAdditions)

+ (NSString *) base64StringFromData:(NSData *)data length:(int)length;

@end

-------------------------------------------

#import "NSStringAdditions.h"

static char base64EncodingTable[64] = {
  'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
  'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
  'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
  'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
};

@implementation NSString (NSStringAdditions)

+ (NSString *) base64StringFromData: (NSData *)data length: (int)length {
  unsigned long ixtext, lentext;
  long ctremaining;
  unsigned char input[3], output[4];
  short i, charsonline = 0, ctcopy;
  const unsigned char *raw;
  NSMutableString *result;

  lentext = [data length]; 
  if (lentext < 1)
    return @"";
  result = [NSMutableString stringWithCapacity: lentext];
  raw = [data bytes];
  ixtext = 0; 

  while (true) {
    ctremaining = lentext - ixtext;
    if (ctremaining <= 0) 
       break;        
    for (i = 0; i < 3; i++) { 
       unsigned long ix = ixtext + i;
       if (ix < lentext)
          input[i] = raw[ix];
       else
  input[i] = 0;
  }
  output[0] = (input[0] & 0xFC) >> 2;
  output[1] = ((input[0] & 0x03) << 4) | ((input[1] & 0xF0) >> 4);
  output[2] = ((input[1] & 0x0F) << 2) | ((input[2] & 0xC0) >> 6);
  output[3] = input[2] & 0x3F;
  ctcopy = 4;
  switch (ctremaining) {
    case 1: 
      ctcopy = 2; 
      break;
    case 2: 
      ctcopy = 3; 
      break;
  }

  for (i = 0; i < ctcopy; i++)
     [result appendString: [NSString stringWithFormat: @"%c", base64EncodingTable[output[i]]]];

  for (i = ctcopy; i < 4; i++)
     [result appendString: @"="];

  ixtext += 3;
  charsonline += 4;

  if ((length > 0) && (charsonline >= length))
    charsonline = 0;
  }     
  return result;
}

@end

For Base64 decoding:

#import <Foundation/Foundation.h>

@class NSString;

@interface NSData (NSDataAdditions)

+ (NSData *) base64DataFromString:(NSString *)string;

@end

-------------------------------------------

#import "NSDataAdditions.h"

@implementation NSData (NSDataAdditions)

+ (NSData *)base64DataFromString: (NSString *)string
{
    unsigned long ixtext, lentext;
    unsigned char ch, inbuf[4], outbuf[3];
    short i, ixinbuf;
    Boolean flignore, flendtext = false;
    const unsigned char *tempcstring;
    NSMutableData *theData;

    if (string == nil)
    {
        return [NSData data];
    }

    ixtext = 0;

    tempcstring = (const unsigned char *)[string UTF8String];

    lentext = [string length];

    theData = [NSMutableData dataWithCapacity: lentext];

    ixinbuf = 0;

    while (true)
    {
        if (ixtext >= lentext)
        {
            break;
        }

        ch = tempcstring [ixtext++];

        flignore = false;

        if ((ch >= 'A') && (ch <= 'Z'))
        {
            ch = ch - 'A';
        }
        else if ((ch >= 'a') && (ch <= 'z'))
        {
            ch = ch - 'a' + 26;
        }
        else if ((ch >= '0') && (ch <= '9'))
        {
            ch = ch - '0' + 52;
        }
        else if (ch == '+')
        {
            ch = 62;
        }
        else if (ch == '=')
        {
            flendtext = true;
        }
        else if (ch == '/')
        {
            ch = 63;
        }
        else
        {
            flignore = true; 
        }

        if (!flignore)
        {
            short ctcharsinbuf = 3;
            Boolean flbreak = false;

            if (flendtext)
            {
                if (ixinbuf == 0)
                {
                    break;
                }

                if ((ixinbuf == 1) || (ixinbuf == 2))
                {
                    ctcharsinbuf = 1;
                }
                else
                {
                    ctcharsinbuf = 2;
                }

                ixinbuf = 3;

                flbreak = true;
            }

            inbuf [ixinbuf++] = ch;

            if (ixinbuf == 4)
            {
                ixinbuf = 0;

                outbuf[0] = (inbuf[0] << 2) | ((inbuf[1] & 0x30) >> 4);
                outbuf[1] = ((inbuf[1] & 0x0F) << 4) | ((inbuf[2] & 0x3C) >> 2);
                outbuf[2] = ((inbuf[2] & 0x03) << 6) | (inbuf[3] & 0x3F);

                for (i = 0; i < ctcharsinbuf; i++)
                {
                    [theData appendBytes: &outbuf[i] length: 1];
                }
            }

            if (flbreak)
            {
                break;
            }
        }
    }

    return theData;
}

    @end

Open Jquery modal dialog on click event

Try adding this line before your dialog line.

$( "#dialog" ).dialog( "open" );

This method worked for me. It seems that the "close" command messes up the dialog opening again with only the .dialog() .

Using your code as an example, it would go in like this (note that you may need to add more to your code for it to make sense):

    <script type="text/javascript">
$(document).ready(function() {
    //$('#dialog').dialog();
    $('#dialog_link').click(function() {
$( "#dialog" ).dialog( "open" );        
$('#dialog').dialog();
        return false;
    });
});
</script>    
</head><body>
   <div id="dialog" title="Dialog Title" style="display:none"> Some text</div>  
   <p id="dialog_link">Open Dialog</p>  
</body></html>

Remove the title bar in Windows Forms

 Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None

Fastest way to check if a string matches a regexp in ruby?

Starting with Ruby 2.4.0, you may use RegExp#match?:

pattern.match?(string)

Regexp#match? is explicitly listed as a performance enhancement in the release notes for 2.4.0, as it avoids object allocations performed by other methods such as Regexp#match and =~:

Regexp#match?
Added Regexp#match?, which executes a regexp match without creating a back reference object and changing $~ to reduce object allocation.