Programs & Examples On #Voldemort

Voldemort is a distributed key-value storage system used by LinkedIn. The source code is available under the Apache 2.0 license. The Voldemort project website is http://www.project-voldemort.com/voldemort/

Maven2: Missing artifact but jars are in place

sudo eclipse

The issue for me was related to @maximilianus's question - in that eclipse was unable to locate the artifacts on my machine.

Turns out all I had to do was run ubuntu as super user, and eclipse could access the /root/.m2/ directory

(Not sure this is good practice, but it solved a problem I've spent hours on)

Edit: This is not definitely good practice, instead I setup my environment all over again, as a normal user rather than root, and it worked fine! (Learning Linux)

Register .NET Framework 4.5 in IIS 7.5

Hosting asp.net 4.5/4.5.1 Web application on Local IIS 1)Be Sure IIS Installation before Visual Installation Installataion then aspnet_regiis will already registerd with IIS

If Not Install IIS and then Register aspnet_regiis with IIS by cmd Editor

For VS2012 and 32 bit OS Run Below code on command editor :

1)Install IIS First & then

2)

cd C:\Windows\Microsoft.NET\Framework\v4.0.30319   

  C:\Windows\Microsoft.NET\Framework\v4.0.30319> aspnet_regiis -i

For VS2012 and 64 bit OS Below code on command editor:

1)Install IIS First & then

2)

cd C:\Windows\Microsoft.NET\Framework64\v4.0.30319    
  C:\Windows\Microsoft.NET\Framework64\v4.0.30319> aspnet_regiis -i

BY Following Above Steps Current Version of VS2012 registered with IIS Hosting (VS2012 Web APP)

Create VS2012 Web Application(WebForm/MVC) then Build Application Right Click On WebApplication(WebForm/MVC) go to 'Properties' Click On 'Web' Tab on then 'Use Local IIS Web Server' Then Uncheck 'Use IIS Express' (If Visul Studio 2013 Select 'Local IIS' from Dropdown) Provide Project Url like "http://localhost/MvcDemoApp" Then Click On 'Create Virtual Directory' Button Then Open IIS by Prssing 'Window + R' Run Command and type 'inetmgr' and 'Enter' (or 'OK' Button) Then Expand 'Sites->Default Web Site' you Hosted Successfully. If Still Gets any Server Error like 'The resource cannot be found.' Then Include following code in web.config

 <configuration>
     <system.webServer>
         <modules runAllManagedModulesForAllRequests="true"></modules>

And Run Application

If still problem occurs Check application pool by : In iis Right click on application->Manage Application->Advanced setting->General. you see the application pool. then close advance setting window. click on 'Application Pools' you will see the all application pools in middle window. Right click on application pool in which application hosted(DefaultAppPool). click 'Basic Setting' -> Change .Net FrameWork Version to->.Net FrameWork v4.0.30349

Where can I get a list of Ansible pre-defined variables?

There are 3 sources of variables in Ansible:

  1. Variables gathered from facts. You can get them by running command: ansible -m setup hostname

  2. Built-in (pre-defined) Ansible variables (AKA 'magic' variables). They are documented in Ansible documentation: http://docs.ansible.com/playbooks_variables.html#magic-variables-and-how-to-access-information-about-other-hosts
    Here is the list extracted from Ansible 1.9 documentation:

    • group_names
    • groups
    • inventory_hostname
    • ansible_hostname
    • inventory_hostname_short
    • play_hosts
    • delegate_to
    • inventory_dir
    • inventory_file
  3. Variables passed to ansible via command line. But obviously you know what they are

When is std::weak_ptr useful?

Apart from the other already mentioned valid use cases std::weak_ptr is an awesome tool in a multithreaded environment, because

  • It doesn't own the object and so can't hinder deletion in a different thread
  • std::shared_ptr in conjunction with std::weak_ptr is safe against dangling pointers - in opposite to std::unique_ptr in conjunction with raw pointers
  • std::weak_ptr::lock() is an atomic operation (see also About thread-safety of weak_ptr)

Consider a task to load all images of a directory (~10.000) simultaneously into memory (e.g. as a thumbnail cache). Obviously the best way to do this is a control thread, which handles and manages the images, and multiple worker threads, which load the images. Now this is an easy task. Here's a very simplified implementation (join() etc is omitted, the threads would have to be handled differently in a real implementation etc)

// a simplified class to hold the thumbnail and data
struct ImageData {
  std::string path;
  std::unique_ptr<YourFavoriteImageLibData> image;
};

// a simplified reader fn
void read( std::vector<std::shared_ptr<ImageData>> imagesToLoad ) {
   for( auto& imageData : imagesToLoad )
     imageData->image = YourFavoriteImageLib::load( imageData->path );
}

// a simplified manager
class Manager {
   std::vector<std::shared_ptr<ImageData>> m_imageDatas;
   std::vector<std::unique_ptr<std::thread>> m_threads;
public:
   void load( const std::string& folderPath ) {
      std::vector<std::string> imagePaths = readFolder( folderPath );
      m_imageDatas = createImageDatas( imagePaths );
      const unsigned numThreads = std::thread::hardware_concurrency();
      std::vector<std::vector<std::shared_ptr<ImageData>>> splitDatas = 
        splitImageDatas( m_imageDatas, numThreads );
      for( auto& dataRangeToLoad : splitDatas )
        m_threads.push_back( std::make_unique<std::thread>(read, dataRangeToLoad) );
   }
};

But it becomes much more complicated, if you want to interrupt the loading of the images, e.g. because the user has chosen a different directory. Or even if you want to destroy the manager.

You'd need thread communication and have to stop all loader threads, before you may change your m_imageDatas field. Otherwise the loaders would carry on loading until all images are done - even if they are already obsolete. In the simplified example, that wouldn't be too hard, but in a real environment things can be much more complicated.

The threads would probably be part of a thread pool used by multiple managers, of which some are being stopped, and some aren't etc. The simple parameter imagesToLoad would be a locked queue, into which those managers push their image requests from different control threads with the readers popping the requests - in an arbitrary order - at the other end. And so the communication becomes difficult, slow and error-prone. A very elegant way to avoid any additional communication in such cases is to use std::shared_ptr in conjunction with std::weak_ptr.

// a simplified reader fn
void read( std::vector<std::weak_ptr<ImageData>> imagesToLoad ) {
   for( auto& imageDataWeak : imagesToLoad ) {
     std::shared_ptr<ImageData> imageData = imageDataWeak.lock();
     if( !imageData )
        continue;
     imageData->image = YourFavoriteImageLib::load( imageData->path );
   }
}

// a simplified manager
class Manager {
   std::vector<std::shared_ptr<ImageData>> m_imageDatas;
   std::vector<std::unique_ptr<std::thread>> m_threads;
public:
   void load( const std::string& folderPath ) {
      std::vector<std::string> imagePaths = readFolder( folderPath );
      m_imageDatas = createImageDatas( imagePaths );
      const unsigned numThreads = std::thread::hardware_concurrency();
      std::vector<std::vector<std::weak_ptr<ImageData>>> splitDatas = 
        splitImageDatasToWeak( m_imageDatas, numThreads );
      for( auto& dataRangeToLoad : splitDatas )
        m_threads.push_back( std::make_unique<std::thread>(read, dataRangeToLoad) );
   }
};

This implementation is nearly as easy as the first one, doesn't need any additional thread communication, and could be part of a thread pool/queue in a real implementation. Since the expired images are skipped, and non-expired images are processed, the threads never would have to be stopped during normal operation. You could always safely change the path or destroy your managers, since the reader fn checks, if the owning pointer isn't expired.

Android: how to make an activity return results to the activity which calls it?

If you want to finish and just add a resultCode (without data), you can call setResult(int resultCode) before finish().

For example:

...
if (everything_OK) {
    setResult(Activity.RESULT_OK); // OK! (use whatever code you want)
    finish();
}
else {
   setResult(Activity.RESULT_CANCELED); // some error ...
   finish();
}
...

Then in your calling activity, check the resultCode, to see if we're OK.

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == someCustomRequestCode) {
        if (resultCode == Activity.RESULT_OK) {
            // OK!
        }
        else if (resultCode = Activity.RESULT_CANCELED) {
            // something went wrong :-(
        }
    }
}

Don't forget to call the activity with startActivityForResult(intent, someCustomRequestCode).

How to hash a string into 8 digits?

Just to complete JJC answer, in python 3.5.3 the behavior is correct if you use hashlib this way:

$ python3 -c '
import hashlib
hash_object = hashlib.sha256(b"Caroline")
hex_dig = hash_object.hexdigest()
print(hex_dig)
'
739061d73d65dcdeb755aa28da4fea16a02b9c99b4c2735f2ebfa016f3e7fded
$ python3 -c '
import hashlib
hash_object = hashlib.sha256(b"Caroline")
hex_dig = hash_object.hexdigest()
print(hex_dig)
'
739061d73d65dcdeb755aa28da4fea16a02b9c99b4c2735f2ebfa016f3e7fded

$ python3 -V
Python 3.5.3

Execute command on all files in a directory

The following bash code will pass $file to command where $file will represent every file in /dir

for file in /dir/*
do
  cmd [option] "$file" >> results.out
done

Example

el@defiant ~/foo $ touch foo.txt bar.txt baz.txt
el@defiant ~/foo $ for i in *.txt; do echo "hello $i"; done
hello bar.txt
hello baz.txt
hello foo.txt

How do I call a Django function on button click?

here is a pure-javascript, minimalistic approach. I use JQuery but you can use any library (or even no libraries at all).

<html>
    <head>
        <title>An example</title>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
        <script>
            function call_counter(url, pk) {
                window.open(url);
                $.get('YOUR_VIEW_HERE/'+pk+'/', function (data) {
                    alert("counter updated!");
                });
            }
        </script>
    </head>
    <body>
        <button onclick="call_counter('http://www.google.com', 12345);">
            I update object 12345
        </button>
        <button onclick="call_counter('http://www.yahoo.com', 999);">
            I update object 999
        </button>
    </body>
</html>

Alternative approach

Instead of placing the JavaScript code, you can change your link in this way:

<a target="_blank" 
    class="btn btn-info pull-right" 
    href="{% url YOUR_VIEW column_3_item.pk %}/?next={{column_3_item.link_for_item|urlencode:''}}">
    Check It Out
</a>

and in your views.py:

def YOUR_VIEW_DEF(request, pk):
    YOUR_OBJECT.objects.filter(pk=pk).update(views=F('views')+1)
    return HttpResponseRedirect(request.GET.get('next')))

How to convert View Model into JSON object in ASP.NET MVC?

Well done, you've only just started using MVC and you've found its first major flaw.

You don't really want to be converting it to JSON in the view, and you don't really want to convert it in the controller, as neither of these locations make sense. Unfortunately, you're stuck with this situation.

The best thing I've found to do is send the JSON to the view in a ViewModel, like this:

var data = somedata;
var viewModel = new ViewModel();
var serializer = new JavaScriptSerializer();
viewModel.JsonData = serializer.Serialize(data);

return View("viewname", viewModel);

then use

<%= Model.JsonData %>

in your view. Be aware that the standard .NET JavaScriptSerializer is pretty crap.

doing it in the controller at least makes it testable (although not exactly like the above - you probably want to take an ISerializer as a dependency so you can mock it)

Update also, regarding your JavaScript, it would be good practice to wrap ALL the widget JS you have above like so:

(
    // all js here
)();

this way if you put multiple widgets on a page, you won't get conflicts (unless you need to access the methods from elsewhere in the page, but in that case you should be registering the widget with some widget framework anyway). It may not be a problem now, but it would be good practice to add the brackets now to save yourself muchos effort in the future when it becomes a requirement, it's also good OO practice to encapsulate the functionality.

What can <f:metadata>, <f:viewParam> and <f:viewAction> be used for?

Send params from View to an other View, from Sender View to Receiver View use viewParam and includeViewParams=true

In Sender

  1. Declare params to be sent. We can send String, Object,…

Sender.xhtml

<f:metadata>
      <f:viewParam name="ID" value="#{senderMB._strID}" />
</f:metadata>
  1. We’re going send param ID, it will be included with “includeViewParams=true” in return String of click button event Click button fire senderMB.clickBtnDetail(dto) with dto from senderMB._arrData

Sender.xhtml

<p:dataTable rowIndexVar="index" id="dataTale"value="#{senderMB._arrData}" var="dto">
      <p:commandButton action="#{senderMB.clickBtnDetail(dto)}" value="??" 
      ajax="false"/>
</p:dataTable>

In senderMB.clickBtnDetail(dto) we assign _strID with argument we got from button event (dto), here this is Sender_DTO and assign to senderMB._strID

Sender_MB.java
    public String clickBtnDetail(sender_DTO sender_dto) {
        this._strID = sender_dto.getStrID();
        return "Receiver?faces-redirect=true&includeViewParams=true";
    }

The link when clicked will become http://localhost:8080/my_project/view/Receiver.xhtml?*ID=12345*

In Recever

  1. Get viewParam Receiver.xhtml In Receiver we declare f:viewParam to get param from get request (receive), the name of param of receiver must be the same with sender (page)

Receiver.xhtml

<f:metadata><f:viewParam name="ID" value="#{receiver_MB._strID}"/></f:metadata>

It will get param ID from sender View and assign to receiver_MB._strID

  1. Use viewParam In Receiver, we want to use this param in sql query before the page render, so that we use preRenderView event. We are not going to use constructor because constructor will be invoked before viewParam is received So that we add

Receiver.xhtml

<f:event listener="#{receiver_MB.preRenderView}" type="preRenderView" />

into f:metadata tag

Receiver.xhtml

<f:metadata>
<f:viewParam name="ID" value="#{receiver_MB._strID}" />
<f:event listener="#{receiver_MB.preRenderView}"
            type="preRenderView" />
</f:metadata>

Now we want to use this param in our read database method, it is available to use

Receiver_MB.java
public void preRenderView(ComponentSystemEvent event) throws Exception {
        if (FacesContext.getCurrentInstance().isPostback()) {
            return;
        }
        readFromDatabase();
    }
private void readFromDatabase() {
//use _strID to read and set property   
}

"message failed to fetch from registry" while trying to install any module

One thing that has worked for me with random npm install errors (where the package that errors out is different under different times (but same environment) is to use this:

npm cache clean

And then repeat the process. Then the process seems to go smoother and the real problem and error message will emerge, where you can fix it and then proceed.

This is based on experience of running npm install of a whole bunch of packages under a pretty bare Ubuntu installation inside a Docker instance. Sometimes there are build/make tools missing from the Ubuntu and the npm errors will not show the real problem until you clean the cache for some reason.

How to use if, else condition in jsf to display image

For those like I who just followed the code by skuntsel and received a cryptic stack trace, allow me to save you some time.

It seems c:if cannot by itself be followed by c:otherwise.

The correct solution is as follows:

<c:choose>
    <c:when test="#{some.test}">
        <p>some.test is true</p>
    </c:when>
    <c:otherwise>
        <p>some.test is not true</p>
    </c:otherwise>
</c:choose>

You can add additional c:when tests in as necessary.

How to make <label> and <input> appear on the same line on an HTML form?

For Bootstrap 4 it could be done with class="form-group" style="display: flex"

<div class="form-group" style="display: flex">
    <label>Topjava comment:</label>
    <input class="form-control" type="checkbox"/>
</div>

Declaring an enum within a class

Nowadays - using C++11 - you can use enum class for this:

enum class Color { RED, BLUE, WHITE };

AFAII this does exactly what you want.

git-diff to ignore ^M

Is there an option like "treat ^M as newline when diffing" ?

There will be one with Git 2.16 (Q1 2018), as the "diff" family of commands learned to ignore differences in carriage return at the end of line.

See commit e9282f0 (26 Oct 2017) by Junio C Hamano (gitster).
Helped-by: Johannes Schindelin (dscho).
(Merged by Junio C Hamano -- gitster -- in commit 10f65c2, 27 Nov 2017)

diff: --ignore-cr-at-eol

A new option --ignore-cr-at-eol tells the diff machinery to treat a carriage-return at the end of a (complete) line as if it does not exist.

Just like other "--ignore-*" options to ignore various kinds of whitespace differences, this will help reviewing the real changes you made without getting distracted by spurious CRLF<->LF conversion made by your editor program.

Javascript to set hidden form value on drop down change

Plain old Javascript:

<script type="text/javascript">

function changeHiddenInput (objDropDown)
{
    var objHidden = document.getElementById("hiddenInput");
    objHidden.value = objDropDown.value; 
}

</script>
<form>
    <select id="dropdown" name="dropdown" onchange="changeHiddenInput(this)">
        <option value="1">One</option>
        <option value="2">Two</option>
        <option value="3">Three</option>
    </select>

    <input type="hidden" name="hiddenInput" id="hiddenInput" value="" />
</form>

how to add the missing RANDR extension

I had the same problem with Firefox 30 + Selenium 2.49 + Ubuntu 15.04.

It worked fine with Ubuntu 14 but after upgrade to 15.04 I got same RANDR warning and problem at starting Firefox using Xfvb.

After adding +extension RANDR it worked again.

$ vim /etc/init/xvfb.conf

#!upstart
description "Xvfb Server as a daemon"

start on filesystem and started networking
stop on shutdown

respawn

env XVFB=/usr/bin/Xvfb
env XVFBARGS=":10 -screen 1 1024x768x24 -ac +extension GLX +extension RANDR +render -noreset"
env PIDFILE=/var/run/xvfb.pid

exec start-stop-daemon --start --quiet --make-pidfile --pidfile $PIDFILE --exec $XVFB -- $XVFBARGS >> /var/log/xvfb.log 2>&1

How to configure XAMPP to send mail from localhost?

You have to configure SMTP on your server. You can use G Suite SMTP by Google for free:

<?php

$mail = new PHPMailer(true);

// Send mail using Gmail
if($send_using_gmail){
    $mail->IsSMTP(); // telling the class to use SMTP
    $mail->SMTPAuth = true; // enable SMTP authentication
    $mail->SMTPSecure = "ssl"; // sets the prefix to the servier
    $mail->Host = "smtp.gmail.com"; // sets GMAIL as the SMTP server
    $mail->Port = 465; // set the SMTP port for the GMAIL server
    $mail->Username = "[email protected]"; // GMAIL username
    $mail->Password = "your-gmail-password"; // GMAIL password
}

// Typical mail data
$mail->AddAddress($email, $name);
$mail->SetFrom($email_from, $name_from);
$mail->Subject = "My Subject";
$mail->Body = "Mail contents";

try{
    $mail->Send();
    echo "Success!";
} catch(Exception $e){
    // Something went bad
    echo "Fail :(";
}

?>

Read more about PHPMailer here.

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

From git checkout's usage:

-2, --ours            checkout our version for unmerged files
-3, --theirs          checkout their version for unmerged files
-m, --merge           perform a 3-way merge with the new branch

When resolving merge conflicts, you can do git checkout --theirs some_file, and git checkout --ours some_file to reset the file to the current version and the incoming versions respectively.

If you've done git checkout --ours some_file or git checkout --theirs some_file and would like to reset the file to the 3-way merge version of the file, you can do git checkout --merge some_file.

How to find Oracle Service Name

Connect to the database with the "system" user, and execute the following command:

show parameter service_name 

What is console.log?

It is used to log (anything you pass it) to the Firebug console. The main usage would be to debug your JavaScript code.

Convert .cer certificate to .jks

Export a certificate from a keystore:

keytool -export -alias mydomain -file mydomain.crt -keystore keystore.jks

Using pickle.dump - TypeError: must be str, not bytes

The output file needs to be opened in binary mode:

f = open('varstor.txt','w')

needs to be:

f = open('varstor.txt','wb')

How to use PHP with Visual Studio

Maybe we should help you with a big misunderstanding on your side first: PHP is (like ASP.NET or whatever you used to far) a server side language while javascript is client side.

This means that PHP will run on your webserver and create a HTML page dynamically which is then sent to the browser. Javascript in turn is embedded (either directly or as a referenced file) into this HTML page and runs in the browser.

Maybe you can now understand why your approach so far could never work out.

How to check if array is empty or does not exist?

You want to do the check for undefined first. If you do it the other way round, it will generate an error if the array is undefined.

if (array === undefined || array.length == 0) {
    // array empty or does not exist
}

Update

This answer is getting a fair amount of attention, so I'd like to point out that my original answer, more than anything else, addressed the wrong order of the conditions being evaluated in the question. In this sense, it fails to address several scenarios, such as null values, other types of objects with a length property, etc. It is also not very idiomatic JavaScript.

The foolproof approach
Taking some inspiration from the comments, below is what I currently consider to be the foolproof way to check whether an array is empty or does not exist. It also takes into account that the variable might not refer to an array, but to some other type of object with a length property.

if (!Array.isArray(array) || !array.length) {
  // array does not exist, is not an array, or is empty
  // ? do not attempt to process array
}

To break it down:

  1. Array.isArray(), unsurprisingly, checks whether its argument is an array. This weeds out values like null, undefined and anything else that is not an array.
    Note that this will also eliminate array-like objects, such as the arguments object and DOM NodeList objects. Depending on your situation, this might not be the behavior you're after.

  2. The array.length condition checks whether the variable's length property evaluates to a truthy value. Because the previous condition already established that we are indeed dealing with an array, more strict comparisons like array.length != 0 or array.length !== 0 are not required here.

The pragmatic approach
In a lot of cases, the above might seem like overkill. Maybe you're using a higher order language like TypeScript that does most of the type-checking for you at compile-time, or you really don't care whether the object is actually an array, or just array-like.

In those cases, I tend to go for the following, more idiomatic JavaScript:

if (!array || !array.length) {
    // array or array.length are falsy
    // ? do not attempt to process array
}

Or, more frequently, its inverse:

if (array && array.length) {
    // array and array.length are truthy
    // ? probably OK to process array
}

With the introduction of the optional chaining operator (Elvis operator) in ECMAScript 2020, this can be shortened even further:

if (!array?.length) {
    // array or array.length are falsy
    // ? do not attempt to process array
}

Or the opposite:

if (array?.length) {
    // array and array.length are truthy
    // ? probably OK to process array
}

How do I Search/Find and Replace in a standard string?

I believe this would work. It takes const char*'s as a parameter.

//params find and replace cannot be NULL
void FindAndReplace( std::string& source, const char* find, const char* replace )
{
   //ASSERT(find != NULL);
   //ASSERT(replace != NULL);
   size_t findLen = strlen(find);
   size_t replaceLen = strlen(replace);
   size_t pos = 0;

   //search for the next occurrence of find within source
   while ((pos = source.find(find, pos)) != std::string::npos)
   {
      //replace the found string with the replacement
      source.replace( pos, findLen, replace );

      //the next line keeps you from searching your replace string, 
      //so your could replace "hello" with "hello world" 
      //and not have it blow chunks.
      pos += replaceLen; 
   }
}

validate natural input number with ngpattern

This is working

<form name="myform" ng-submit="create()">
    <input type="number"
           name="price_field"
           ng-model="price"
           require
           ng-pattern="/^\d{0,9}(\.\d{1,9})?$/">
    <span  ng-show="myform.price_field.$error.pattern">Not valid number!</span>
    <input type="submit" class="btn">
 </form>

Google Maps JavaScript API RefererNotAllowedMapError

I struggled to make this work as well, but here are some pointers:

  • The URLs set as referrers include http, e.g. http://example.com/*
  • Google Maps JavaScript API was enabled
  • Billing was set-up on this account

Once all of this above was resolved, the maps displayed as expected.

HTML span align center not working?

On top of all the other explanations, I believe you're using equal "=" sign, instead of colon ":":

<span style="border:1px solid red;text-align=center">

It should be:

<span style="border:1px solid red;text-align:center">

Decimal values in SQL for dividing results

CAST( ROUND(columnA *1.00 / columnB, 2) AS FLOAT)

PHP : send mail in localhost

You will need to install a local mailserver in order to do this. If you want to send it to external e-mail addresses, it might end up in unwanted e-mails or it may not arrive at all.

A good mailserver which I use (I use it on Linux, but it's also available for Windows) is Axigen: http://www.axigen.com/mail-server/download/

You might need some experience with mailservers to install it, but once it works, you can do anything you want with it.

UTF-8 encoded html pages show ? (questions marks) instead of characters

In my case, database returned latin1, when my browser expected utf8.

So for MySQLi I did:

 mysqli_set_charset($dblink, "utf8");    

See http://php.net/manual/en/mysqli.set-charset.php for more info

Is there a way to override class variables in Java?

You can create a getter and then override that getter. It's particularly useful if the variable you are overriding is a sub-class of itself. Imagine your super class has an Object member but in your sub-class this is now more defined to be an Integer.

class Dad
{
        private static final String me = "dad";

        protected String getMe() {
            return me;
        }

        public void printMe()
        {
                System.out.println(getMe());
        }
}

class Son extends Dad
{
        private static final String me = "son";

        @Override
        protected String getMe() {
            return me;
        }
}

public void doIt()
{
        new Son().printMe(); //Prints "son"
}

Convert varchar to uniqueidentifier in SQL Server

SELECT CONVERT(uniqueidentifier,STUFF(STUFF(STUFF(STUFF('B33D42A3AC5A4D4C81DD72F3D5C49025',9,0,'-'),14,0,'-'),19,0,'-'),24,0,'-'))

How do I make a transparent border with CSS?

You can use "transparent" as a colour. In some versions of IE, that comes up as black, but I've not tested it out since the IE6 days.

http://www.researchkitchen.de/blog/archives/css-bordercolor-transparent.php

How to set the java.library.path from Eclipse

Click Run
Click Debug ...
New Java Application
Click Arguments tab
in the 2nd box (VM Arguments) add the -D entry

-Xdebug -verbose:gc -Xbootclasspath/p:jar/vbjorb.jar;jar/oracle9.jar;classes;jar/mq.jar;jar/xml4j.jar -classpath -DORBInitRef=NameService=iioploc://10.101.2.94:8092/NameService  

etc...

Where is the Microsoft.IdentityModel dll

I had a similar problem. I got an exception "Type is not resolved for member 'Microsoft.IdentityModel.Claims.ClaimsPrincipal, Microsoft.IdentityModel, Version = 3.5.0.0, Culture = neutral, PublicKeyToken = 31bf3856ad364e35'.".

I tried to run the ASP.NET application from Visual Studio, which was a reference to a local copy of Microsoft.IdentityModel.dll.

I did not want to install the SDK and I had to copy the library to the directory "C: \ Program Files \ Common Files \ Microsoft Shared \ DevServer \ 10.0" and restart Visual Studio.

How do I get java logging output to appear on a single line?

if you're using java.util.logging, then there is a configuration file that is doing this to log contents (unless you're using programmatic configuration). So, your options are
1) run post -processor that removes the line breaks
2) change the log configuration AND remove the line breaks from it. Restart your application (server) and you should be good.

WAMP shows error 'MSVCR100.dll' is missing when install

If you don't understand anything then download vcredist_x86.exe from http://www.microsoft.com/en-us/download/details.aspx?id=8328 . It will solve your problem.

How can I initialise a static Map?

Maybe it's interesting to check out Google Collections, e.g. the videos that they have on their page. They provide various ways to initialize maps and sets, and provide immutable collections as well.

Update: This library is now named Guava.

Get final URL after curl is redirected

This would work:

 curl -I somesite.com | perl -n -e '/^Location: (.*)$/ && print "$1\n"'

const to Non-const Conversion in C++

The actual code to cast away the const-ness of your pointer would be:

BoxT<T> * nonConstObj = const_cast<BoxT<T> *>(constObj);

But note that this really is cheating. A better solution would either be to figure out why you want to modify a const object, and redesign your code so you don't have to.... or remove the const declaration from your vector, if it turns out you don't really want those items to be read-only after all.

How to add directory to classpath in an application run profile in IntelliJ IDEA?

I am using Idea 8. in your module dependancies tab (in the project structure dialog). Add a "Module Library". There you can select a Jar Directory to add. Then make sure the run profile is using the Classpath and JDK of the correct module when it runs (this is in the run config dialog.

Checking if a character is a special character in Java

This method checks if a String contains a special character (based on your definition).

/**
 *  Returns true if s contains any character other than 
 *  letters, numbers, or spaces.  Returns false otherwise.
 */

public boolean containsSpecialCharacter(String s) {
    return (s == null) ? false : s.matches("[^A-Za-z0-9 ]");
}

You can use the same logic to count special characters in a string like this:

/**
 *  Counts the number of special characters in s.
 */

 public int getSpecialCharacterCount(String s) {
     if (s == null || s.trim().isEmpty()) {
         return 0;
     }
     int theCount = 0;
     for (int i = 0; i < s.length(); i++) {
         if (s.substring(i, 1).matches("[^A-Za-z0-9 ]")) {
             theCount++;
         }
     }
     return theCount;
 }

Another approach is to put all the special chars in a String and use String.contains:

/**
 *  Counts the number of special characters in s.
 */

 public int getSpecialCharacterCount(String s) {
     if (s == null || s.trim().isEmpty()) {
         return 0;
     }
     int theCount = 0;
     String specialChars = "/*!@#$%^&*()\"{}_[]|\\?/<>,.";
     for (int i = 0; i < s.length(); i++) {
         if (specialChars.contains(s.substring(i, 1))) {
             theCount++;
         }
     }
     return theCount;
 }

NOTE: You must escape the backslash and " character with a backslashes.


The above are examples of how to approach this problem in general.

For your exact problem as stated in the question, the answer by @LanguagesNamedAfterCoffee is the most efficient approach.

How to show progress dialog in Android?

ProgressDialog pd = new ProgressDialog(yourActivity.this);
pd.setMessage("loading");
pd.show();

And that's all you need.

How to call multiple functions with @click in vue?

I'd add, that you can also use this to call multiple emits or methods or both together by separating with ; semicolon

  @click="method1(); $emit('emit1'); $emit('emit2');"

How To Execute SSH Commands Via PHP

Do you have the SSH2 extension available?

Docs: http://www.php.net/manual/en/function.ssh2-exec.php

$connection = ssh2_connect('shell.example.com', 22);
ssh2_auth_password($connection, 'username', 'password');

$stream = ssh2_exec($connection, '/usr/local/bin/php -i');

Function not defined javascript

The actual problem is with your

showList function.

There is an extra ')' after 'visible'.

Remove that and it will work fine.

function showList()
{
  if (document.getElementById("favSports").style.visibility == "hidden") 
    {
       // document.getElementById("favSports").style.visibility = "visible");  
       // your code
       document.getElementById("favSports").style.visibility = "visible";
       // corrected code
    }
}

Disable autocomplete via CSS

You can't use CSS to disable autocomplete, but you can use HTML:

<input type="text" autocomplete="false" />

Technically you can replace false with any invalid value and it'll work. This iOS the only solution I've found which also works in Edge.

When to use %r instead of %s in Python?

This is a version of Ben James's answer, above:

>>> import datetime
>>> x = datetime.date.today()
>>> print x
2013-01-11
>>> 
>>> 
>>> print "Today's date is %s ..." % x
Today's date is 2013-01-11 ...
>>> 
>>> print "Today's date is %r ..." % x
Today's date is datetime.date(2013, 1, 11) ...
>>>

When I ran this, it helped me see the usefulness of %r.

jquery simple image slideshow tutorial

I dont know why you havent marked on of these gr8 answers... here is another option which would enable you and anyone else visiting to control transition speed and pause time

JAVASCRIPT

$(function () {

    /* SET PARAMETERS */
    var change_img_time     = 5000; 
    var transition_speed    = 100;

    var simple_slideshow    = $("#exampleSlider"),
        listItems           = simple_slideshow.children('li'),
        listLen             = listItems.length,
        i                   = 0,

        changeList = function () {

            listItems.eq(i).fadeOut(transition_speed, function () {
                i += 1;
                if (i === listLen) {
                    i = 0;
                }
                listItems.eq(i).fadeIn(transition_speed);
            });

        };

    listItems.not(':first').hide();
    setInterval(changeList, change_img_time);

});

.

HTML

<ul id="exampleSlider">
    <li><img src="http://placehold.it/500x250" alt="" /></li>
    <li><img src="http://placehold.it/500x250" alt="" /></li>
    <li><img src="http://placehold.it/500x250" alt="" /></li>
    <li><img src="http://placehold.it/500x250" alt="" /></li>
</ul>

.
If your keeping this simple its easy to keep it resposive
best to visit the: DEMO

.
If you want something with special transition FX (Still responsive) - check this out
DEMO WITH SPECIAL FX

In LaTeX, how can one add a header/footer in the document class Letter?

This code works to insert both header and footer on the first page with header center aligned and footer left aligned

\makeatletter
\let\old@ps@headings\ps@headings
\let\old@ps@IEEEtitlepagestyle\ps@IEEEtitlepagestyle
\def\confheader#1{%
  % for the first page
  \def\ps@IEEEtitlepagestyle{%
    \old@ps@IEEEtitlepagestyle%
    \def\@oddhead{\strut\hfill#1\hfill\strut}%
    \def\@evenhead{\strut\hfill#1\hfill\strut}%
 \def\@oddfoot{\mycopyrightnotice}
  \def\@evenfoot{}
  }%
  \ps@headings%
}
\makeatother

\confheader{%
  5$^{th}$  IEEE International Conference on Recent Advances and Innovations in Engineering - ICRAIE 2020 (IEEE Record\#51050) %EDIT HERE
}

\def\mycopyrightnotice{
  {\footnotesize XXX-1-7281-8867-6/20/\$31.00~\copyright~2020 IEEE\hfill} % EDIT HERE
  \gdef\mycopyrightnotice{}

}

\newcommand*{\affmark}[1][*]{\textsuperscript{#1}}


\def\BibTeX{{\rm B\kern-.05em{\sc i\kern-.025em b}\kern-.08em
    T\kern-.1667em\lower.7ex\hbox{E}\kern-.125emX}}
\newcommand{\ma}[1]{\mbox{\boldmath$#1$}} ```

Write string to text file and ensure it always overwrites the existing content.

Use the File.WriteAllText method. It creates the file if it doesn't exist and overwrites it if it exists.

Getting the last element of a list

lst[-1] is the best approach, but with general iterables, consider more_itertools.last:

Code

import more_itertools as mit


mit.last([0, 1, 2, 3])
# 3

mit.last(iter([1, 2, 3]))
# 3

mit.last([], "some default")
# 'some default'

How to search file text for a pattern and replace it with a given value

Here's a solution for find/replace in all files of a given directory. Basically I took the answer provided by sepp2k and expanded it.

# First set the files to search/replace in
files = Dir.glob("/PATH/*")

# Then set the variables for find/replace
@original_string_or_regex = /REGEX/
@replacement_string = "STRING"

files.each do |file_name|
  text = File.read(file_name)
  replace = text.gsub!(@original_string_or_regex, @replacement_string)
  File.open(file_name, "w") { |file| file.puts replace }
end

What is the best way to detect a mobile device?

I use this solution and it works fine on all devices:

if (typeof window.orientation !== "undefined" || navigator.userAgent.indexOf('IEMobile') !== -1) {
   //is_mobile
}

BootStrap : Uncaught TypeError: $(...).datetimepicker is not a function

This is a bit late but I know it will help someone:

If you are using datetimepicker make sure you include the right CSS and JS files. datetimepicker uses(Take note of their names);

https://cdnjs.cloudflare.com/ajax/libs/bootstrap-datetimepicker/4.17.37/css/bootstrap-datetimepicker.css

and

https://cdnjs.cloudflare.com/ajax/libs/bootstrap-datetimepicker/4.17.37/js/bootstrap-datetimepicker.min.js

On the above question asked by @mindfreak,The main problem is due to the imported files.

Read/Write String from/to a File in Android

the first thing we need is the permissions in AndroidManifest.xml

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_INTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_INTERNAL_STORAGE" />

so in an asyncTask Kotlin class, we treat the creation of the file

    import android.os.AsyncTask
    import android.os.Environment
    import android.util.Log
    import java.io.*
    class WriteFile: AsyncTask<String, Int, String>() {
        private val mFolder = "/MainFolder"
        lateinit var folder: File
        internal var writeThis = "string to cacheApp.txt"
        internal var cacheApptxt = "cacheApp.txt"
        override fun doInBackground(vararg writethis: String): String? {
            val received = writethis[0]
            if(received.isNotEmpty()){
                writeThis = received
            }
            folder = File(Environment.getExternalStorageDirectory(),"$mFolder/")
            if(!folder.exists()){
                folder.mkdir()
                val readME = File(folder, cacheApptxt)
                val file = File(readME.path)
                val out: BufferedWriter
                try {
                    out = BufferedWriter(FileWriter(file, true), 1024)
                    out.write(writeThis)
                    out.newLine()
                    out.close()
                    Log.d("Output_Success", folder.path)
                } catch (e: Exception) {
                    Log.d("Output_Exception", "$e")
                }
            }
            return folder.path

    }

        override fun onPostExecute(result: String) {
            super.onPostExecute(result)

            if(result.isNotEmpty()){
                //implement an interface or do something
                Log.d("onPostExecuteSuccess", result)
            }else{
                Log.d("onPostExecuteFailure", result)
            }
        }

    }

Of course if you are using Android above Api 23, you must handle the request to allow writing to device memory. Something like this

    import android.Manifest
    import android.content.Context
    import android.content.pm.PackageManager
    import android.os.Build
    import androidx.appcompat.app.AppCompatActivity
    import androidx.core.app.ActivityCompat
    import androidx.core.content.ContextCompat

    class ReadandWrite {
        private val mREAD = 9
        private val mWRITE = 10
        private var readAndWrite: Boolean = false
        fun readAndwriteStorage(ctx: Context, atividade: AppCompatActivity): Boolean {
            if (Build.VERSION.SDK_INT < 23) {
                readAndWrite = true
            } else {
                val mRead = ContextCompat.checkSelfPermission(ctx, Manifest.permission.READ_EXTERNAL_STORAGE)
                val mWrite = ContextCompat.checkSelfPermission(ctx, Manifest.permission.WRITE_EXTERNAL_STORAGE)

                if (mRead != PackageManager.PERMISSION_GRANTED) {
                    ActivityCompat.requestPermissions(atividade, arrayOf(Manifest.permission.READ_EXTERNAL_STORAGE), mREAD)
                } else {
                    readAndWrite = true
                }

                if (mWrite != PackageManager.PERMISSION_GRANTED) {
                    ActivityCompat.requestPermissions(atividade, arrayOf(Manifest.permission.WRITE_EXTERNAL_STORAGE), mWRITE)
                } else {
                    readAndWrite = true
                }
            }
            return readAndWrite
        }
    }

then in an activity, execute the call.

  var pathToFileCreated = ""
    val anRW = ReadandWrite().readAndwriteStorage(this,this)
    if(anRW){
        pathToFileCreated =  WriteFile().execute("onTaskComplete").get()
        Log.d("pathToFileCreated",pathToFileCreated)
    }

Default visibility for C# classes and members (fields, methods, etc.)?

By default, the access modifier for a class is internal. That means to say, a class is accessible within the same assembly. But if we want the class to be accessed from other assemblies then it has to be made public.

How to filter WooCommerce products by custom attribute

You can use the WooCommerce Layered Nav widget, which allows you to use different sets of attributes as filters for products. Here's the "official" description:

Shows a custom attribute in a widget which lets you narrow down the list of products when viewing product categories.

If you look into plugins/woocommerce/widgets/widget-layered_nav.php, you can see the way it operates with the attributes in order to set filters. The URL then looks like this:

http://yoursite.com/shop/?filtering=1&filter_min-kvadratura=181&filter_max-kvadratura=108&filter_obem-ohlajdane=111

... and the digits are actually the id-s of the different attribute values, that you want to set.

How to get height of Keyboard?

Swift 4 and Constraints

To your tableview add a bottom constraint relative to the bottom safe area. In my case the constraint is called tableViewBottomLayoutConstraint.

@IBOutlet weak var tableViewBottomLayoutConstraint: NSLayoutConstraint!

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillAppear(notification:)), name: .UIKeyboardWillShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillDisappear(notification:)), name: .UIKeyboardWillHide, object: nil)
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)

    NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillShow , object: nil)
    NotificationCenter.default.removeObserver(self, name: .UIKeyboardWillHide , object: nil)
}

@objc 
func keyboardWillAppear(notification: NSNotification?) {

    guard let keyboardFrame = notification?.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue else {
        return
    }

    let keyboardHeight: CGFloat
    if #available(iOS 11.0, *) {
        keyboardHeight = keyboardFrame.cgRectValue.height - self.view.safeAreaInsets.bottom
    } else {
        keyboardHeight = keyboardFrame.cgRectValue.height
    }

    tableViewBottomLayoutConstraint.constant = keyboardHeight
}

@objc 
func keyboardWillDisappear(notification: NSNotification?) {
    tableViewBottomLayoutConstraint.constant = 0.0
}

how to parse JSONArray in android

If you're after the 'name', why does your code snippet look like an attempt to get the 'characters'?

Anyways, this is no different from any other list- or array-like operation: you just need to iterate over the dataset and grab the information you're interested in. Retrieving all the names should look somewhat like this:

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

JSONArray cast = jsonResponse.getJSONArray("abridged_cast");
for (int i=0; i<cast.length(); i++) {
    JSONObject actor = cast.getJSONObject(i);
    String name = actor.getString("name");
    allNames.add(name);
}

(typed straight into the browser, so not tested).

Better solution without exluding fields from Binding

You should not use your domain models in your views. ViewModels are the correct way to do it.

You need to map your domain model's necessary fields to viewmodel and then use this viewmodel in your controllers. This way you will have the necessery abstraction in your application.

If you never heard of viewmodels, take a look at this.

How to get current PHP page name

$_SERVER["PHP_SELF"]; will give you the current filename and its path, but basename(__FILE__) should give you the filename that it is called from.

So

if(basename(__FILE__) == 'file_name.php') {
  //Hide
} else {
  //show
}

should do it.

What to do with branch after merge

If you DELETE the branch after merging it, just be aware that all hyperlinks, URLs, and references of your DELETED branch will be BROKEN.

How to get single value from this multi-dimensional PHP array

Look at the keys and indentation in your print_r:

echo $myarray[0]['email'];

echo $myarray[0]['gender'];

...etc

Open text file and program shortcut in a Windows batch file

Try using:

@ECHO off
ECHO Hello World!

START /MAX D:\SA\pro\hello.txt

Getting the error "Missing $ inserted" in LaTeX

I had the same problem - and I have read all these answers, but unfortunately none of them worked for me. Eventually I tried removing this line

%\usepackage[latin1]{inputenc}

and all errors disappeared.

SQL Server - Adding a string to a text column (concat equivalent)

like said before best would be to set datatype of the column to nvarchar(max), but if that's not possible you can do the following using cast or convert:

-- create a test table 
create table test (
    a text
) 
-- insert test value
insert into test (a) values ('this is a text')
-- the following does not work !!!
update test set a = a + ' and a new text added'
-- but this way it works: 
update test set a = cast ( a as nvarchar(max))  + cast (' and a new text added' as nvarchar(max) )
-- test result
select * from test
-- column a contains:
this is a text and a new text added

hope that helps

How to word wrap text in HTML?

Try this

_x000D_
_x000D_
div{_x000D_
  display: block;_x000D_
  display: -webkit-box;_x000D_
  height: 20px;_x000D_
  margin: 3px auto;_x000D_
  font-size: 14px;_x000D_
  line-height: 1.4;_x000D_
  -webkit-line-clamp: 1;_x000D_
  -webkit-box-orient: vertical;_x000D_
  overflow: hidden;_x000D_
  text-overflow: ellipsis;_x000D_
}
_x000D_
_x000D_
_x000D_

the property text-overflow: ellipsis add ... and line-clamp show the number of lines.

node.js require all files in a folder?

I have a folder /fields full of files with a single class each, ex:

fields/Text.js -> Test class
fields/Checkbox.js -> Checkbox class

Drop this in fields/index.js to export each class:

var collectExports, fs, path,
  __hasProp = {}.hasOwnProperty;

fs = require('fs');    
path = require('path');

collectExports = function(file) {
  var func, include, _results;

  if (path.extname(file) === '.js' && file !== 'index.js') {
    include = require('./' + file);
    _results = [];
    for (func in include) {
      if (!__hasProp.call(include, func)) continue;
      _results.push(exports[func] = include[func]);
    }
    return _results;
  }
};

fs.readdirSync('./fields/').forEach(collectExports);

This makes the modules act more like they would in Python:

var text = new Fields.Text()
var checkbox = new Fields.Checkbox()

Using column alias in WHERE clause of MySQL query produces an error

Maybe my answer is too late but this can help others.

You can enclose it with another select statement and use where clause to it.

SELECT * FROM (Select col1, col2,...) as t WHERE t.calcAlias > 0

calcAlias is the alias column that was calculated.

How to fix the error; 'Error: Bootstrap tooltips require Tether (http://github.hubspot.com/tether/)'

An additional note. If you check uncompressed javascript file, you will find the condition:

if(window.Tether === undefined) {
     throw new Error('Bootstrap tooltips require Tether (http://github.hubspot.com/tether)')
}

So the error message contains the required information.

You can download the archive from that link.

Uncompressed version:

https://rawgit.com/HubSpot/tether/master/src/js/tether.js https://rawgit.com/HubSpot/tether/master/dist/css/tether.css

How to compile and run C files from within Notepad++ using NppExec plugin?

I've written just this to execute compiling and run the file after, plus fileinputname = fileoutputname on windowsmashines, if your compilerpath is registred in the windows PATH-var:

NPP_SAVE
cd "$(CURRENT_DIRECTORY)"
set LEN~ strrfind $(FILE_NAME) .
set EXENAME ~ substr 0 $(LEN) $(FILE_NAME)
set $(EXENAME) = $(EXENAME).exe
c++.exe "$(FILE_NAME)" -o "$(EXENAME)"
"$(EXENAME)"

should work for any compiler if you change c++.exe to what you want

How is __eq__ handled in Python and in what order?

When Python2.x sees a == b, it tries the following.

  • If type(b) is a new-style class, and type(b) is a subclass of type(a), and type(b) has overridden __eq__, then the result is b.__eq__(a).
  • If type(a) has overridden __eq__ (that is, type(a).__eq__ isn't object.__eq__), then the result is a.__eq__(b).
  • If type(b) has overridden __eq__, then the result is b.__eq__(a).
  • If none of the above are the case, Python repeats the process looking for __cmp__. If it exists, the objects are equal iff it returns zero.
  • As a final fallback, Python calls object.__eq__(a, b), which is True iff a and b are the same object.

If any of the special methods return NotImplemented, Python acts as though the method didn't exist.

Note that last step carefully: if neither a nor b overloads ==, then a == b is the same as a is b.


From https://eev.ee/blog/2012/03/24/python-faq-equality/

Java: Check if command line arguments are null

You should check for (args == null || args.length == 0). Although the null check isn't really needed, it is a good practice.

How can I get the number of days between 2 dates in Oracle 11g?

  • Full days between end of month and start of today, including the last day of the month:

    SELECT LAST_DAY (TRUNC(SysDate)) - TRUNC(SysDate) + 1 FROM dual
    
  • Days between using exact time:

    SELECT SysDate - TO_DATE('2018-01-01','YYYY-MM-DD') FROM dual
    

How can I escape a double quote inside double quotes?

Bash allows you to place strings adjacently, and they'll just end up being glued together.

So this:

$ echo "Hello"', world!'

produces

Hello, world!

The trick is to alternate between single and double-quoted strings as required. Unfortunately, it quickly gets very messy. For example:

$ echo "I like to use" '"double quotes"' "sometimes"

produces

I like to use "double quotes" sometimes

In your example, I would do it something like this:

$ dbtable=example
$ dbload='load data local infile "'"'gfpoint.csv'"'" into '"table $dbtable FIELDS TERMINATED BY ',' ENCLOSED BY '"'"'"' LINES "'TERMINATED BY "'"'\n'"'" IGNORE 1 LINES'
$ echo $dbload

which produces the following output:

load data local infile "'gfpoint.csv'" into table example FIELDS TERMINATED BY ',' ENCLOSED BY '"' LINES TERMINATED BY "'\n'" IGNORE 1 LINES

It's difficult to see what's going on here, but I can annotate it using Unicode quotes. The following won't work in bash – it's just for illustration:

dbload=load data local infile "’“'gfpoint.csv'”‘" into’“table $dbtable FIELDS TERMINATED BY ',' ENCLOSED BY '”‘"’“' LINES”‘TERMINATED BY "’“'\n'”‘" IGNORE 1 LINES

The quotes like “ ‘ ’ ” in the above will be interpreted by bash. The quotes like " ' will end up in the resulting variable.

If I give the same treatment to the earlier example, it looks like this:

$ echoI like to use"double quotes"sometimes

SQL Insert Query Using C#

private void button1_Click(object sender, EventArgs e)
    {
        String query = "INSERT INTO product (productid, productname,productdesc,productqty) VALUES (@txtitemid,@txtitemname,@txtitemdesc,@txtitemqty)";
        try
        {
            using (SqlCommand command = new SqlCommand(query, con))
            {

                command.Parameters.AddWithValue("@txtitemid", txtitemid.Text);
                command.Parameters.AddWithValue("@txtitemname", txtitemname.Text);
                command.Parameters.AddWithValue("@txtitemdesc", txtitemdesc.Text);
                command.Parameters.AddWithValue("@txtitemqty", txtitemqty.Text);


                con.Open();
                int result = command.ExecuteNonQuery();

                // Check Error
                if (result < 0)
                    MessageBox.Show("Error");

                MessageBox.Show("Record...!", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);
                con.Close();
                loader();
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
            con.Close();
        }
    }

How to make space between LinearLayout children?

Using padding in the layout of Child View.

layout.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_margin="5dp"
          android:background="@drawable/backage_text"
          android:textColor="#999999"
           >

</TextView>

backage_text.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">

    <solid android:color="@color/white"/>
    <corners android:radius="2dp"/>
    <stroke
        android:width="1dp"
        android:color="#999999"/>
    <padding
        android:bottom="5dp"
        android:left="10dp"
        android:right="10dp"
        android:top="5dp" />
</shape>

How can I use modulo operator (%) in JavaScript?

That would be the modulo operator, which produces the remainder of the division of two numbers.

CMD: How do I recursively remove the "Hidden"-Attribute of files and directories

if you wanna remove attributes for all files in all folders on whole flash drive do this:

attrib -r -s -h /S /D

this command will remove attrubutes for all files folders and subfolders:

-read only -system file -is hidden -Processes matching files and all subfolders. -Processes folders as well

failed to open stream: No such file or directory in

you can use:

define("PATH_ROOT", dirname(__FILE__));
include_once PATH_ROOT . "/PoliticalForum/headerSite.php";

Replacing a 32-bit loop counter with 64-bit introduces crazy performance deviations with _mm_popcnt_u64 on Intel CPUs

Ok, I want to provide a small answer to one of the sub-questions that the OP asked that don't seem to be addressed in the existing questions. Caveat, I have not done any testing or code generation, or disassembly, just wanted to share a thought for others to possibly expound upon.

Why does the static change the performance?

The line in question: uint64_t size = atol(argv[1])<<20;

Short Answer

I would look at the assembly generated for accessing size and see if there are extra steps of pointer indirection involved for the non-static version.

Long Answer

Since there is only one copy of the variable whether it was declared static or not, and the size doesn't change, I theorize that the difference is the location of the memory used to back the variable along with where it is used in the code further down.

Ok, to start with the obvious, remember that all local variables (along with parameters) of a function are provided space on the stack for use as storage. Now, obviously, the stack frame for main() never cleans up and is only generated once. Ok, what about making it static? Well, in that case the compiler knows to reserve space in the global data space of the process so the location can not be cleared by the removal of a stack frame. But still, we only have one location so what is the difference? I suspect it has to do with how memory locations on the stack are referenced.

When the compiler is generating the symbol table, it just makes an entry for a label along with relevant attributes, like size, etc. It knows that it must reserve the appropriate space in memory but doesn't actually pick that location until somewhat later in process after doing liveness analysis and possibly register allocation. How then does the linker know what address to provide to the machine code for the final assembly code? It either knows the final location or knows how to arrive at the location. With a stack, it is pretty simple to refer to a location based one two elements, the pointer to the stackframe and then an offset into the frame. This is basically because the linker can't know the location of the stackframe before runtime.

Best practices when running Node.js with port 80 (Ubuntu / Linode)

For port 80 (which was the original question), Daniel is exactly right. I recently moved to https and had to switch from iptables to a light nginx proxy managing the SSL certs. I found a useful answer along with a gist by gabrielhpugliese on how to handle that. Basically I

Hopefully that can save someone else some headaches. I'm sure there's a pure-node way of doing this, but nginx was quick and it worked.

What is the maximum possible length of a .NET string?

The max length of a string on my machine is 1,073,741,791.

You see, Strings aren't limited by integer as is commonly believed.

Memory restrictions aside, Strings cannot have more than 230 (1,073,741,824) characters, since a 2GB limit is imposed by the Microsoft CLR (Common Language Runtime). 33 more than my computer allowed.

Now, here's something you're welcome to try yourself.

Create a new C# console app in Visual Studio and then copy/paste the main method here:

static void Main(string[] args)
{
    Console.WriteLine("String test, by Nicholas John Joseph Taylor");

    Console.WriteLine("\nTheoretically, C# should support a string of int.MaxValue, but we run out of memory before then.");

    Console.WriteLine("\nThis is a quickish test to narrow down results to find the max supported length of a string.");

    Console.WriteLine("\nThe test starts ...now:\n");

    int Length = 0;

    string s = "";

    int Increment = 1000000000; // We know that s string with the length of 1000000000 causes an out of memory exception.

    LoopPoint:

    // Make a string appendage the length of the value of Increment

    StringBuilder StringAppendage = new StringBuilder();

    for (int CharacterPosition = 0; CharacterPosition < Increment; CharacterPosition++)
    {
        StringAppendage.Append("0");

    }

    // Repeatedly append string appendage until an out of memory exception is thrown.

    try
    {
        if (Increment > 0)
            while (Length < int.MaxValue)
            {
                Length += Increment;

                s += StringAppendage.ToString(); // Append string appendage the length of the value of Increment

                Console.WriteLine("s.Length = " + s.Length + " at " + DateTime.Now.ToString("dd/MM/yyyy HH:mm"));

            }

    }
    catch (OutOfMemoryException ex) // Note: Any other exception will crash the program.
    {
        Console.WriteLine("\n" + ex.Message + " at " + DateTime.Now.ToString("dd/MM/yyyy HH:mm") + ".");

        Length -= Increment;

        Increment /= 10;

        Console.WriteLine("After decimation, the value of Increment is " + Increment + ".");

    }
    catch (Exception ex2)
    {
        Console.WriteLine("\n" + ex2.Message + " at " + DateTime.Now.ToString("dd/MM/yyyy HH:mm") + ".");

        Console.WriteLine("Press a key to continue...");

        Console.ReadKey();

    }

    if (Increment > 0)
    {
        goto LoopPoint;

    }

    Console.WriteLine("Test complete.");

    Console.WriteLine("\nThe max length of a string is " + s.Length + ".");

    Console.WriteLine("\nPress any key to continue.");

    Console.ReadKey();

}

My results were as follows:

String test, by Nicholas John Joseph Taylor

Theoretically, C# should support a string of int.MaxValue, but we run out of memory before then.

This is a quickish test to narrow down results to find the max supported length of a string.

The test starts ...now:

s.Length = 1000000000 at 08/05/2019 12:06

Exception of type 'System.OutOfMemoryException' was thrown. at 08/05/2019 12:06. After decimation, the value of Increment is 100000000.

Exception of type 'System.OutOfMemoryException' was thrown. at 08/05/2019 12:06. After decimation, the value of Increment is 10000000. s.Length = 1010000000 at 08/05/2019 12:06 s.Length = 1020000000 at 08/05/2019 12:06 s.Length = 1030000000 at 08/05/2019 12:06 s.Length = 1040000000 at 08/05/2019 12:06 s.Length = 1050000000 at 08/05/2019 12:06 s.Length = 1060000000 at 08/05/2019 12:06 s.Length = 1070000000 at 08/05/2019 12:06

Exception of type 'System.OutOfMemoryException' was thrown. at 08/05/2019 12:06. After decimation, the value of Increment is 1000000. s.Length = 1071000000 at 08/05/2019 12:06 s.Length = 1072000000 at 08/05/2019 12:06 s.Length = 1073000000 at 08/05/2019 12:06

Exception of type 'System.OutOfMemoryException' was thrown. at 08/05/2019 12:06. After decimation, the value of Increment is 100000. s.Length = 1073100000 at 08/05/2019 12:06 s.Length = 1073200000 at 08/05/2019 12:06 s.Length = 1073300000 at 08/05/2019 12:06 s.Length = 1073400000 at 08/05/2019 12:06 s.Length = 1073500000 at 08/05/2019 12:06 s.Length = 1073600000 at 08/05/2019 12:06 s.Length = 1073700000 at 08/05/2019 12:06

Exception of type 'System.OutOfMemoryException' was thrown. at 08/05/2019 12:06. After decimation, the value of Increment is 10000. s.Length = 1073710000 at 08/05/2019 12:06 s.Length = 1073720000 at 08/05/2019 12:06 s.Length = 1073730000 at 08/05/2019 12:06 s.Length = 1073740000 at 08/05/2019 12:06

Exception of type 'System.OutOfMemoryException' was thrown. at 08/05/2019 12:06. After decimation, the value of Increment is 1000. s.Length = 1073741000 at 08/05/2019 12:06

Exception of type 'System.OutOfMemoryException' was thrown. at 08/05/2019 12:06. After decimation, the value of Increment is 100. s.Length = 1073741100 at 08/05/2019 12:06 s.Length = 1073741200 at 08/05/2019 12:06 s.Length = 1073741300 at 08/05/2019 12:07 s.Length = 1073741400 at 08/05/2019 12:07 s.Length = 1073741500 at 08/05/2019 12:07 s.Length = 1073741600 at 08/05/2019 12:07 s.Length = 1073741700 at 08/05/2019 12:07

Exception of type 'System.OutOfMemoryException' was thrown. at 08/05/2019 12:07. After decimation, the value of Increment is 10. s.Length = 1073741710 at 08/05/2019 12:07 s.Length = 1073741720 at 08/05/2019 12:07 s.Length = 1073741730 at 08/05/2019 12:07 s.Length = 1073741740 at 08/05/2019 12:07 s.Length = 1073741750 at 08/05/2019 12:07 s.Length = 1073741760 at 08/05/2019 12:07 s.Length = 1073741770 at 08/05/2019 12:07 s.Length = 1073741780 at 08/05/2019 12:07 s.Length = 1073741790 at 08/05/2019 12:07

Exception of type 'System.OutOfMemoryException' was thrown. at 08/05/2019 12:07. After decimation, the value of Increment is 1. s.Length = 1073741791 at 08/05/2019 12:07

Exception of type 'System.OutOfMemoryException' was thrown. at 08/05/2019 12:07. After decimation, the value of Increment is 0. Test complete.

The max length of a string is 1073741791.

Press any key to continue.

The max length of a string on my machine is 1073741791.

I'd appreciate it very much if people could post their results as a comment below.

It will be interesting to learn if people get the same or different results.

How to update/refresh specific item in RecyclerView

A way that has worked for me personally, is using the recyclerview's adapter methods to deal with changes in it's items.

It would go in a way similar to this, create a method in your custom recycler's view somewhat like this:

public void modifyItem(final int position, final Model model) {
    mainModel.set(position, model);
    notifyItemChanged(position);
}

How to check for empty array in vba macro

As you are dealing with a string array, have you considered Join?

If Len(Join(FileNamesList)) > 0 Then

How to declare a global variable in php?

Let's think a little different, You can use static parameters:

class global {
    static $foo = "bar";
}

And you can use and modify it every where you like, like:

function func() {
    echo global::$foo;
}

Inversion of Control vs Dependency Injection

As for this question, I'd say the wiki has already provided detailed and easy-understanding explanations. I will just quote the most significant here.

Implementation of IoC

In object-oriented programming, there are several basic techniques to implement inversion of control. These are:

  1. Using a service locator pattern Using dependency injection, for example Constructor injection Parameter injection Setter injection Interface injection;
  2. Using a contextualized lookup;
  3. Using template method design pattern;
  4. Using strategy design pattern

As for Dependency Injection

dependency injection is a technique whereby one object (or static method) supplies the dependencies of another object. A dependency is an object that can be used (a service). An injection is the passing of a dependency to a dependent object (a client) that would use it.

ORA-01653: unable to extend table by in tablespace ORA-06512

To resolve this error:

ORA-01653 unable to extend table by 1024 in tablespace your-tablespace-name

Just run this PL/SQL command for extended tablespace size automatically on-demand:

alter database datafile '<your-tablespace-name>.dbf' autoextend on maxsize unlimited;

I get this error in import big dump file, just run this command without stopping import routine or restarting the database.

Note: each data file has a limit of 32GB of size if you need more than 32GB you should add a new data file to your existing tablespace.

More info: alter_autoextend_on

Why have header files and .cpp files?

C++ compilation

A compilation in C++ is done in 2 major phases:

  1. The first is the compilation of "source" text files into binary "object" files: The CPP file is the compiled file and is compiled without any knowledge about the other CPP files (or even libraries), unless fed to it through raw declaration or header inclusion. The CPP file is usually compiled into a .OBJ or a .O "object" file.

  2. The second is the linking together of all the "object" files, and thus, the creation of the final binary file (either a library or an executable).

Where does the HPP fit in all this process?

A poor lonesome CPP file...

The compilation of each CPP file is independent from all other CPP files, which means that if A.CPP needs a symbol defined in B.CPP, like:

// A.CPP
void doSomething()
{
   doSomethingElse(); // Defined in B.CPP
}

// B.CPP
void doSomethingElse()
{
   // Etc.
}

It won't compile because A.CPP has no way to know "doSomethingElse" exists... Unless there is a declaration in A.CPP, like:

// A.CPP
void doSomethingElse() ; // From B.CPP

void doSomething()
{
   doSomethingElse() ; // Defined in B.CPP
}

Then, if you have C.CPP which uses the same symbol, you then copy/paste the declaration...

COPY/PASTE ALERT!

Yes, there is a problem. Copy/pastes are dangerous, and difficult to maintain. Which means that it would be cool if we had some way to NOT copy/paste, and still declare the symbol... How can we do it? By the include of some text file, which is commonly suffixed by .h, .hxx, .h++ or, my preferred for C++ files, .hpp:

// B.HPP (here, we decided to declare every symbol defined in B.CPP)
void doSomethingElse() ;

// A.CPP
#include "B.HPP"

void doSomething()
{
   doSomethingElse() ; // Defined in B.CPP
}

// B.CPP
#include "B.HPP"

void doSomethingElse()
{
   // Etc.
}

// C.CPP
#include "B.HPP"

void doSomethingAgain()
{
   doSomethingElse() ; // Defined in B.CPP
}

How does include work?

Including a file will, in essence, parse and then copy-paste its content in the CPP file.

For example, in the following code, with the A.HPP header:

// A.HPP
void someFunction();
void someOtherFunction();

... the source B.CPP:

// B.CPP
#include "A.HPP"

void doSomething()
{
   // Etc.
}

... will become after inclusion:

// B.CPP
void someFunction();
void someOtherFunction();

void doSomething()
{
   // Etc.
}

One small thing - why include B.HPP in B.CPP?

In the current case, this is not needed, and B.HPP has the doSomethingElse function declaration, and B.CPP has the doSomethingElse function definition (which is, by itself a declaration). But in a more general case, where B.HPP is used for declarations (and inline code), there could be no corresponding definition (for example, enums, plain structs, etc.), so the include could be needed if B.CPP uses those declaration from B.HPP. All in all, it is "good taste" for a source to include by default its header.

Conclusion

The header file is thus necessary, because the C++ compiler is unable to search for symbol declarations alone, and thus, you must help it by including those declarations.

One last word: You should put header guards around the content of your HPP files, to be sure multiple inclusions won't break anything, but all in all, I believe the main reason for existence of HPP files is explained above.

#ifndef B_HPP_
#define B_HPP_

// The declarations in the B.hpp file

#endif // B_HPP_

or even simpler (although not standard)

#pragma once

// The declarations in the B.hpp file

TypeError: unhashable type: 'list' when using built-in set function

    python 3.2


    >>>> from itertools import chain
    >>>> eg=sorted(list(set(list(chain(*eg)))), reverse=True)
        [7, 6, 5, 4, 3, 2, 1]


   ##### eg contain 2 list within a list. so if you want to use set() function
   you should flatten the list like [1, 2, 3, 4, 4, 5, 6, 7]

   >>> res= list(chain(*eg))       # [1, 2, 3, 4, 4, 5, 6, 7]                   
   >>> res1= set(res)                    #   [1, 2, 3, 4, 5, 6, 7]
   >>> res1= sorted(res1,reverse=True)

Excel how to fill all selected blank cells with text

If all the cells are under one column, you could just filter the column and then select "(blank)" and then insert any value into the cells. But be careful, press "alt + 4" to make sure you are inserting value into the visible cells only.

Detect if page has finished loading

there are two ways to do this in jquery depending what you are looking for..

using jquery you can do

  • //this will wait for the text assets to be loaded before calling this (the dom.. css.. js)

    $(document).ready(function(){...});
    
  • //this will wait for all the images and text assets to finish loading before executing

    $(window).load(function(){...});
    

Android - Get value from HashMap

This with no warnings!

    HashMap<String, String> meMap=new HashMap<String, String>();
    meMap.put("Color1","Red");
    meMap.put("Color2","Blue");
    meMap.put("Color3","Green");
    meMap.put("Color4","White");

    for (Object o : meMap.keySet()) {
        Toast.makeText(getBaseContext(), meMap.get(o.toString()),
                Toast.LENGTH_SHORT).show();
    }

How to start and stop android service from a adb shell?

If you want to run the script in adb shell, then I am trying to do the same, but with an application. I think you can use "am start" command

usage: am [subcommand] [options]

start an Activity: am start [-D] [-W] <INTENT>
    -D: enable debugging
    -W: wait for launch to complete

**start a Service: am startservice <INTENT>**

send a broadcast Intent: am broadcast <INTENT>

start an Instrumentation: am instrument [flags] <COMPONENT>
    -r: print raw results (otherwise decode REPORT_KEY_STREAMRESULT)
    -e <NAME> <VALUE>: set argument <NAME> to <VALUE>
    -p <FILE>: write profiling data to <FILE>
    -w: wait for instrumentation to finish before returning

start profiling: am profile <PROCESS> start <FILE>
stop profiling: am profile <PROCESS> stop

start monitoring: am monitor [--gdb <port>]
    --gdb: start gdbserv on the given port at crash/ANR

<INTENT> specifications include these flags:
    [-a <ACTION>] [-d <DATA_URI>] [-t <MIME_TYPE>]
    [-c <CATEGORY> [-c <CATEGORY>] ...]
    [-e|--es <EXTRA_KEY> <EXTRA_STRING_VALUE> ...]
    [--esn <EXTRA_KEY> ...]
    [--ez <EXTRA_KEY> <EXTRA_BOOLEAN_VALUE> ...]
    [-e|--ei <EXTRA_KEY> <EXTRA_INT_VALUE> ...]
    [-n <COMPONENT>] [-f <FLAGS>]
    [--grant-read-uri-permission] [--grant-write-uri-permission]
    [--debug-log-resolution]
    [--activity-brought-to-front] [--activity-clear-top]
    [--activity-clear-when-task-reset] [--activity-exclude-from-recents]
    [--activity-launched-from-history] [--activity-multiple-task]
    [--activity-no-animation] [--activity-no-history]
    [--activity-no-user-action] [--activity-previous-is-top]
    [--activity-reorder-to-front] [--activity-reset-task-if-needed]
    [--activity-single-top]
    [--receiver-registered-only] [--receiver-replace-pending]
    [<URI>]

C++ IDE for Macs

Code::Blocks is cross-platform, using the wxWidgets library. It's the one I use.

Get escaped URL parameter

What you really want is the jQuery URL Parser plugin. With this plugin, getting the value of a specific URL parameter (for the current URL) looks like this:

$.url().param('foo');

If you want an object with parameter names as keys and parameter values as values, you'd just call param() without an argument, like this:

$.url().param();

This library also works with other urls, not just the current one:

$.url('http://allmarkedup.com?sky=blue&grass=green').param();
$('#myElement').url().param(); // works with elements that have 'src', 'href' or 'action' attributes

Since this is an entire URL parsing library, you can also get other information from the URL, like the port specified, or the path, protocol etc:

var url = $.url('http://allmarkedup.com/folder/dir/index.html?item=value');
url.attr('protocol'); // returns 'http'
url.attr('path'); // returns '/folder/dir/index.html'

It has other features as well, check out its homepage for more docs and examples.

Instead of writing your own URI parser for this specific purpose that kinda works in most cases, use an actual URI parser. Depending on the answer, code from other answers can return 'null' instead of null, doesn't work with empty parameters (?foo=&bar=x), can't parse and return all parameters at once, repeats the work if you repeatedly query the URL for parameters etc.

Use an actual URI parser, don't invent your own.

For those averse to jQuery, there's a version of the plugin that's pure JS.

OS X Terminal UTF-8 issues

In my case, simply using the uxterm command instead of xterm solved the problem. It's available in /opt/X11/bin/uxterm by installing the XQuartz package provided by Apple.

Get the current date in java.sql.Date format

new java.sql.Date(Calendar.getInstance().getTimeInMillis());

One line if statement not working

For simplicity, If you need to default to some value if nil you can use:

@something.nil? = "No" || "Yes"

How to explain callbacks in plain english? How are they different from calling one function from another function?

A callback is a method that is scheduled to be executed when a condition is met.

An "real world" example is a local video game store. You are waiting for Half-Life 3. Instead of going to the store every day to see if it is in, you register your email on a list to be notified when the game is available. The email becomes your "callback" and the condition to be met is the game's availability.

A "programmers" example is a web page where you want to perform an action when a button is clicked. You register a callback method for a button and continue doing other tasks. When/if the user cicks on the button, the browser will look at the list of callbacks for that event and call your method.

A callback is a way to handle events asynchronously. You can never know when the callback will be executed, or if it will be executed at all. The advantage is that it frees your program and CPU cycles to perform other tasks while waiting for the reply.

Get immediate first child element

Both these will give you the first child node:

console.log(parentElement.firstChild); // or
console.log(parentElement.childNodes[0]);

If you need the first child that is an element node then use:

console.log(parentElement.children[0]);

Edit

Ah, I see your problem now; parentElement is an array.

If you know that getElementsByClassName will only return one result, which it seems you do, you should use [0] to dearray (yes, I made that word up) the element:

var parentElement = document.getElementsByClassName("uniqueClassName")[0];

fatal: could not create work tree dir 'kivy'

In my case what happened was that the user I was using had no ownership over the directory. I simply had to change ownership of the directory to that user. For example if user is ubuntu:

chown ubuntu:ubuntu -R directory-in-question

cd directory-in-question/

git clone <git repo comes here >

How to remove commits from a pull request

You have several techniques to do it.

This post - read the part about the revert will explain in details what we want to do and how to do it.

Here is the most simple solution to your problem:

# Checkout the desired branch
git checkout <branch>

# Undo the desired commit
git revert <commit>

# Update the remote with the undo of the code
git push origin <branch>

The revert command will create a new commit with the undo of the original commit.

cannot convert data (type interface {}) to type string: need type assertion

Type Assertion

This is known as type assertion in golang, and it is a common practice.

Here is the explanation from a tour of go:

A type assertion provides access to an interface value's underlying concrete value.

t := i.(T)

This statement asserts that the interface value i holds the concrete type T and assigns the underlying T value to the variable t.

If i does not hold a T, the statement will trigger a panic.

To test whether an interface value holds a specific type, a type assertion can return two values: the underlying value and a boolean value that reports whether the assertion succeeded.

t, ok := i.(T)

If i holds a T, then t will be the underlying value and ok will be true.

If not, ok will be false and t will be the zero value of type T, and no panic occurs.

NOTE: value i should be interface type.

Pitfalls

Even if i is an interface type, []i is not interface type. As a result, in order to convert []i to its value type, we have to do it individually:

// var items []i
for _, item := range items {
    value, ok := item.(T)
    dosomethingWith(value)
}

Performance

As for performance, it can be slower than direct access to the actual value as show in this stackoverflow answer.

Not Able To Debug App In Android Studio

This solved my problem. Uninstall app from device and run it again via Android studio.

Using :: in C++

The :: is called scope resolution operator. Can be used like this:

:: identifier
class-name :: identifier
namespace :: identifier

You can read about it here
https://docs.microsoft.com/en-us/cpp/cpp/scope-resolution-operator?view=vs-2017

Get Value of a Edit Text field

I guess you will have to use this code when calling the "mEdit" your EditText object :

myActivity.this.mEdit.getText().toString()

Just make sure that the compiler know which EditText to call and use.

Python loop counter in a for loop

enumerate is what you are looking for.

You might also be interested in unpacking:

# The pattern
x, y, z = [1, 2, 3]

# also works in loops:
l = [(28, 'M'), (4, 'a'), (1990, 'r')]
for x, y in l:
    print(x)  # prints the numbers 28, 4, 1990

# and also
for index, (x, y) in enumerate(l):
    print(x)  # prints the numbers 28, 4, 1990

Also, there is itertools.count() so you could do something like

import itertools

for index, el in zip(itertools.count(), [28, 4, 1990]):
    print(el)  # prints the numbers 28, 4, 1990

Custom circle button

With the official Material Components library you can use the MaterialButton applying a Widget.MaterialComponents.Button.Icon style.

Something like:

   <com.google.android.material.button.MaterialButton
            android:layout_width="48dp"
            android:layout_height="48dp"
            style="@style/Widget.MaterialComponents.Button.Icon"
            app:icon="@drawable/ic_add"
            app:iconSize="24dp"
            app:iconPadding="0dp"
            android:insetLeft="0dp"
            android:insetTop="0dp"
            android:insetRight="0dp"
            android:insetBottom="0dp"
            app:shapeAppearanceOverlay="@style/ShapeAppearanceOverlay.MyApp.Button.Rounded"
            />

Currently the app:iconPadding="0dp",android:insetLeft,android:insetTop,android:insetRight,android:insetBottom attributes are needed to center the icon on the button avoiding extra padding space.

Use the app:shapeAppearanceOverlay attribute to get rounded corners. In this case you will have a circle.

  <style name="ShapeAppearanceOverlay.MyApp.Button.Rounded" parent="">
    <item name="cornerFamily">rounded</item>
    <item name="cornerSize">50%</item>
  </style>

The final result:

enter image description here

Regular expression for decimal number

In general, i.e. unlimited decimal places:

^-?(([1-9]\d*)|0)(.0*[1-9](0*[1-9])*)?$

Border around specific rows in a table?

Group rows together using the <tbody> tag and then apply style.

<table>
  <tr><td>No Style here</td></tr>
  <tbody class="red-outline">
    <tr><td>Style me</td></tr>
    <tr><td>And me</td></tr>
  </tbody>
  <tr><td>No Style here</td></tr>
</table>  

And the css in style.css

.red-outline {
  outline: 1px solid red;
}

Filter object properties by key in ES6

This function will filter an object based on a list of keys, its more efficient than the previous answer as it doesn't have to use Array.filter before calling reduce. so its O(n) as opposed to O(n + filtered)

function filterObjectByKeys (object, keys) {
  return Object.keys(object).reduce((accum, key) => {
    if (keys.includes(key)) {
      return { ...accum, [key]: object[key] }
    } else {
      return accum
    }
  }, {})
}

android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database

Please make sure you are not trying to open and close the database repeatedly either from main thread or background thread.

Make a singleton class in your application and try to create and open data from this class only.

Is guarantees you that database open call is made only when it does not exist.

In your entire application use the same approach of getting sqLiteDatabase object when it is required.

I used below code and my problem is solved now after 1.5 days.

...............................................................

In Your Activity class onCreate() method

public class MainActivity extends AppCompatActivity   {  
   private AssetsDatabaseHelper helper;    

@Override        
protected void onCreate(Bundle savedInstanceState) {        
helper = AssetsDatabaseHelper.getInstance(this);      
    sqLiteDatabase = helper.getDatabase();     
    }    
}    

public class AssetsDatabaseHelper {    
    Context context;    
    SQLiteDatabase sqLiteDatabase;    
    DatabaseHelper databaseHelper;    
    private static AssetsDatabaseHelper instance;    

    private  AssetsDatabaseHelper(Context context){    
        this.context = context;    

        databaseHelper = new DatabaseHelper(context);    
        if(databaseHelper.checkDatabase()){    
            try{    
                databaseHelper.openDatabase();    
            }catch(SQLException sqle){    
                Log.e("Exception in opening ", " :: database :: sqle.getCause() : "+sqle.getCause());    
            }    
        }else{    
            try{    
                databaseHelper.createDatabase();    
            }catch(IOException ioe){    
                Log.d("Exception in creating ", " :: database :: ioe.getCause() : "+ioe.getCause());    
            }
            try{    
                databaseHelper.openDatabase();    
            }catch(SQLException sqle){    
Log.e("Exception in opening ", " :: database :: "+sqle.getCause());    
            }    
        }
         sqLiteDatabase = databaseHelper.getSqLiteDatabase();    
    }    

    public static AssetsDatabaseHelper getInstance(Context context){    
        if(instance != null){    
            return instance;    
        }else {     
            instance = new AssetsDatabaseHelper(context);    
            return instance;     
        }    
    }  


    public SQLiteDatabase getDatabase(){    
        return sqLiteDatabase;        
    }      
}    

wampserver doesn't go green - stays orange

Make a Ctrl+Alt+Suppr in order to see if no other Apache version is ever runing on your computer. It was the case for me, I just stop them and the light pass green!

Cheers!

Absolute Positioning & Text Alignment

position: absolute;
color: #ffffff;
font-weight: 500;
top: 0%;
left: 0%;
right: 0%;
text-align: center;

How to set default Checked in checkbox ReactJS?

You may pass "true" or "" to the checked property of input checkbox. The empty quotes ("") will be understood as false and the item will be unchecked.

let checked = variable === value ? "true" : "";
<input
     className="form-check-input"
    type="checkbox"
    value={variable}
    id={variable}
    name={variable}
    checked={checked}
/>
<label className="form-check-label">{variable}</label>

How do I restore a dump file from mysqldump?

You can also use the restore menu in MySQL Administrator. You just have to open the back-up file, and then click the restore button.

Common sources of unterminated string literal

I've had trouble with angled quotes in the past ( ‘ ) usually from copy and pasting from Word. Replacing them with regular single quotes ( ' ) does the trick.

How to disable and then enable onclick event on <div> with javascript

I'm confused by your question, seems to me that the question title and body are asking different things. If you want to disable/enable a click event on a div simply do:

$("#id").on('click', function(){ //enables click event
    //do your thing here
});

$("#id").off('click'); //disables click event

If you want to disable a div, use the following code:

$("#id").attr('disabled','disabled');

Hope this helps.

edit: oops, didn't see the other bind/unbind answer. Sorry. Those methods are also correct, though they've been deprecated in jQuery 1.7, and replaced by on()/off()

How to initialize a JavaScript Date to a particular time zone

I know its 3 years too late, but maybe it can help someone else because I haven't found anything like that except for the moment-timezone library, which is not exactly the same as what he's asking for here.

I've done something similar for german timezone, this is a little complex because of daylight saving time and leap years where you have 366 days.

it might need a little work with the "isDaylightSavingTimeInGermany" function while different timezones change on different times the daylight saving time.

anyway, check out this page: https://github.com/zerkotin/german-timezone-converter/wiki

the main methods are: convertLocalDateToGermanTimezone convertGermanDateToLocalTimezone

I've put an effort into documenting it, so it won't be so confusing.

C++ Array of pointers: delete or delete []?

The second one is correct under the circumstances (well, the least wrong, anyway).

Edit: "least wrong", as in the original code shows no good reason to be using new or delete in the first place, so you should probably just use:

std::vector<Monster> monsters;

The result will be simpler code and cleaner separation of responsibilities.

Fastest way to count number of occurrences in a Python list

You can use pandas, by transforming the list to a pd.Series then simply use .value_counts()

import pandas as pd
a = ['1', '1', '1', '1', '1', '1', '2', '2', '2', '2', '7', '7', '7', '10', '10']
a_cnts = pd.Series(a).value_counts().to_dict()

Input  >> a_cnts["1"], a_cnts["10"]
Output >> (6, 2)

Replace special characters in a string with _ (underscore)

string = string.replace(/[&\/\\#,+()$~%.'":*?<>{}]/g,'_');

Alternatively, to change all characters except numbers and letters, try:

string = string.replace(/[^a-zA-Z0-9]/g,'_');

Scraping: SSL: CERTIFICATE_VERIFY_FAILED error for http://en.wikipedia.org

I'm a relative novice compared to all the experts on Stack Overflow.

I have 2 versions of jupyter notebook running (one through a fresh Anaconda Navigator installation and one through ????). I think this is because Anaconda was installed as a local installation on my Mac (per Anaconda instructions).

I already had python 3.7 installed. After that, I used my terminal to open jupyter notebook and I think that it put another version globally onto my Mac.

However, I'm not sure because I'm just learning through trial and error!

I did the terminal command:

conda install -c anaconda certifi 

(as directed above, but it didn't work.)

My python 3.7 is installed on OS Catalina10.15.3 in:

  • /Library/Python/3.7/site-packages AND
  • ~/Library/Python/3.7/lib/python/site-packages

The certificate is at:

  • ~/Library/Python/3.7/lib/python/site-packages/certifi-2019.11.28.dist-info

I tried to find the Install Certificate.command ... but couldn't find it through looking through the file structures...not in Applications...not in links above.

I finally installed it by finding it through Spotlight (as someone suggested above). And it double clicked automatically and installed ANOTHER certificate in the same folder as:

  • ~/Library/Python/3.7/lib/python/site-packages/

NONE of the above solved anything for me...I still got the same error.

So, I solved the problem by:

  1. closing my jupyter notebook.
  2. opening Anaconda Navigator.
  3. opening jupyter notebook through the Navigator GUI (instead of through Terminal).
  4. opening my notebook and running the code.

I can't tell you why this worked. But it solved the problem for me.

I just want to save someone the hassle next time. If someone can tell my why it worked, that would be terrific.

I didn't try the other terminal commands because of the 2 versions of jupyter notebook that I knew were a problem. I just don't know how to fix that.

How to programmatically turn off WiFi on Android device?

You need the following permissions in your manifest file:

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

Then you can use the following in your activity class:

WifiManager wifiManager = (WifiManager) this.getApplicationContext().getSystemService(Context.WIFI_SERVICE); 
wifiManager.setWifiEnabled(true);
wifiManager.setWifiEnabled(false);

Use the following to check if it's enabled or not

boolean wifiEnabled = wifiManager.isWifiEnabled()

You'll find a nice tutorial on the subject on this site.

Data truncated for column?

when i first tried to import csv into mysql , i got the same error , and then i figured out mysql table i created doesn't have the character length of the importing csv field , so if it's the first time importing csv

  1. its a good idea to give more character length .
  2. label all fields as varchar or text , don't blend int or other values.

then you are good to go.

Display Adobe pdf inside a div

Here is another way to display PDF inside Div by using Iframe like below.

_x000D_
_x000D_
<div>_x000D_
  <iframe src="/pdf/test.pdf" style="width:100%;height:700px;"></iframe>_x000D_
</div>_x000D_
<div>_x000D_
  <!-- I agree button -->_x000D_
</div>
_x000D_
_x000D_
_x000D_

What is the difference between attribute and property?

<property attribute="attributeValue">proopertyValue</property>

would be one way to look at it.

In C#

[Attribute]
public class Entity
{
    private int Property{get; set;};

How can I lock the first row and first column of a table when scrolling, possibly using JavaScript and CSS?

You need two tables, where the first one is an exact overlay over the second one. The second one contains all the data, where the first one just contains the first column. You have to synchronize it's width and depending on the content also the height of it's rows.

Additional to this two tables, you need a third one. That's the first row, which lays exactly between the other two and has to be synchronized in the same way.

You will need absolute positioning here. Next, you would synchronize the scrolling of the data table with the scrolling positions of the head row and first column table.

That works very well in all major browsers, except for one issue: The synchronized scrolling will flutter. To fix that, you need two outher div containers that hold a clone of the content of the header row and the first column. When scrolling vertically, you display the header row clone to prevent fluttering, while you reposition the original in the background. When scrolling horizontally, you would show the first row clone. Same thing here.

error: No resource identifier found for attribute 'adSize' in package 'com.google.example' main.xml

I usually embed the xmlns:ads property into the adview properties this way:

<com.google.android.gms.ads.AdView
    xmlns:ads="http://schemas.android.com/apk/res-auto"
    android:id="@+id/adView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    ads:adSize="BANNER"
    ads:adUnitId="@string/banner_ad_unit_id"/>

so that you dont need to embed into the parent every and each time you copy the adview.

Just copy and paste the adview above and paste it anywhere and it should work

Java 8 Lambda function that throws exception?

If you don't mind using a third party library, with cyclops-react, a library I contribute to, you can use the FluentFunctions API to write

 Function<String, Integer> standardFn = FluentFunctions.ofChecked(this::myMethod);

ofChecked takes a jOO? CheckedFunction and returns the reference softened back to a standard (unchecked) JDK java.util.function.Function.

Alternatively you can keep working with the captured function via the FluentFunctions api!

For example to execute your method, retrying it up to 5 times and logging it's status you can write

  FluentFunctions.ofChecked(this::myMethod)
                 .log(s->log.debug(s),e->log.error(e,e.getMessage())
                 .try(5,1000)
                 .apply("my param");

Set the table column width constant regardless of the amount of text in its cells?

What I do is:

  1. Set the td width:

    <td width="200" height="50"><!--blaBlaBla Contents here--></td>
    
  2. Set the td width with CSS:

    <td style="width:200px; height:50px;">
    
  3. Set the width again as max and min with CSS:

    <td style="max-width:200px; min-width:200px; max-height:50px; min-height:50px; width:200px; height:50px;">
    

It sounds little bit repetitive but it gives me the desired result. To achieve this with much ease, you may need put the CSS values in a class in your style-sheet:

.td_size {    
  width:200px; 
  height:50px;
  max-width:200px;
  min-width:200px; 
  max-height:50px; 
  min-height:50px;
  **overflow:hidden;** /*(Optional)This might be useful for some overflow contents*/   
}

then:

<td class="td_size">

Place the class attribute to any <td> you want.

Create a dropdown component

Hope this will help to someone. Works fine in Angular 6 with reactive forms. Can operate by keyboard too.

dropdown.component.html

<div class="dropdown-wrapper {{className}} {{isFocused ? 'focus':''}}" [ngClass]="{'is-open':isOpen, 'disabled':isReadOnly}" *ngIf="options" (contextmenu)="$event.stopPropagation();">
  <div class="box" (click)="toggle($event)">
    <ng-container>
      <div class="dropdown-selected" *ngIf="isSelectedValue" l10nTranslate><span>{{options[selected]}}</span></div>
      <div class="dropdown-selected" *ngIf="!isSelectedValue" l10nTranslate><span>{{placeholder}}</span></div>
    </ng-container>
  </div>

  <ul class="dropdown-options" *ngIf="options">
    <li *ngIf="placeholder" (click)="$event.stopPropagation()">{{placeholder}}</li>
    <ng-container>
      <li id="li{{i}}"
        *ngFor="let option of options; let i = index"
        [class.active]="selected === i"
        (click)="optionSelect(option, i, $event)"
        l10nTranslate
      >
        {{option}}
      </li>
    </ng-container>

  </ul>
</div>

dropdown.component.scss

@import "../../../assets/scss/variables";

// DROPDOWN STYLES
.dropdown-wrapper {
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    border: 1px solid #DDDDDD;
    border-radius: 3px;
    cursor: pointer;
    position: relative;
    &.focus{
        border: 1px solid #a8a8a8;
    }
    .box {
        display: -webkit-box;
        display: -ms-flexbox;
        display: flex;
        width: 100%;
    } 

    // SELECTED
    .dropdown-selected {
        height: 30px;
        position: relative;
        padding: 10px 30px 10px 10px;
        display: -webkit-box;
        display: -ms-flexbox;
        display: flex;
        -webkit-box-align: center;
            -ms-flex-align: center;
                align-items: center;
        width: 100%;
        font-size: 12px;
        color: #666666;
        overflow: hidden;
        background-color: #fff;
        &::before {
            content: "";
            position: absolute;
            top: 50%;
            right: 5px;
            -webkit-transform: translateY(-50%);
                    transform: translateY(-50%);
            width: 22px;
            height: 22px;
            background: url('/assets/i/dropdown-open-selector.svg');
            background-size: 22px 22px;
        }
        span {
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
        }
    } 

    // DROPDOWN OPTIONS
    .dropdown-options {
        display: none;
        position: absolute;
        padding: 8px 6px 9px 5px;
        max-height: 261px;
        overflow-y: auto;
        z-index: 999;
        li {
            padding: 10px 25px 10px 10px;
            font-size: $regular-font-size;
            color: $content-text-black;
            position: relative;
            line-height: 10px;
            &:last-child {
                border-bottom: none;
            }
            &:hover {
                background-color: #245A88;
                border-radius: 3px;
                color: #fff;
                border-bottom-color: transparent;
            }
            &:focus{
                background-color: #245A88;
                border-radius: 3px;
                color: #fff;
            }
            &.active {
                background-color: #245A88;
                border-radius: 3px;
                color: #fff;
                border-bottom-color: transparent;
            }
            &:hover {
                background-color: #7898B3
            }
            &.active {
                font-weight: 600;
            }
        }
    }
    &.is-open {
        .dropdown-selected {
            &::before {
                content: "";
                position: absolute;
                top: 50%;
                right: 5px;
                -webkit-transform: translateY(-50%);
                        transform: translateY(-50%);
                width: 22px;
                height: 22px;
                background: url('/assets/i/dropdown-close-selector.svg');
                background-size: 22px 22px;
            }
        }
        .dropdown-options {
            display: -webkit-box;
            display: -ms-flexbox;
            display: flex;
            -webkit-box-orient: vertical;
            -webkit-box-direction: normal;
                -ms-flex-direction: column;
                    flex-direction: column;
            width: 100%;
            top: 32px;
            border-radius: 3px;
            background-color: #ffffff;
            border: 1px solid #DDDDDD;
            -webkit-box-shadow: 0px 3px 11px 0 rgba(1, 2, 2, 0.14);
                    box-shadow: 0px 3px 11px 0 rgba(1, 2, 2, 0.14);
        }
    }
    &.data-input-fields {
        .box {
            height: 35px;
        }
    }
    &.send-email-table-select {
        min-width: 140px;
        border: none;
    }
    &.persoanal-settings {
        width: 80px;
    }
}

div.dropdown-wrapper.disabled
{
  pointer-events: none;
  background-color: #F1F1F1;
  opacity: 0.7;
}

dropdown.component.ts

import { Component, OnInit, Input, Output, EventEmitter, HostListener, forwardRef } from '@angular/core';
import { ControlValueAccessor, NG_VALUE_ACCESSOR } from '@angular/forms';

const noop = () => {
};

export const CUSTOM_INPUT_CONTROL_VALUE_ACCESSOR: any = {
  provide: NG_VALUE_ACCESSOR,
  useExisting: forwardRef(() => DropdownComponent),
  multi: true
};

@Component({
  selector: 'app-dropdown',
  templateUrl: './dropdown.component.html',
  styleUrls: ['./dropdown.component.scss'],
  providers: [CUSTOM_INPUT_CONTROL_VALUE_ACCESSOR]
})
export class DropdownComponent implements OnInit, ControlValueAccessor {

  @Input() options: Array<string>;
  @Input() selected: number;
  @Input() className: string;
  @Input() placeholder: string;
  @Input() isReadOnly = false;
  @Output() optSelect = new EventEmitter();
  isOpen = false;
  selectedOption;


  private onTouchedCallback: () => void = noop;
  private onChangeCallback: (_: any) => void = noop;
  isSelectedValue: boolean;
  key: string;
  isFocused: boolean;

  /**
   *Creates an instance of DropdownComponent.
   * @memberof DropdownComponent
   */

  ngOnInit() {
    // Place default value in dropdown
    if (this.selected) {
      this.placeholder = '';
      this.isOpen = false;
    }
  }

  @HostListener('focus')
  focusHandler() {
    this.selected = 0;
    this.isFocused = true;
  }

  @HostListener('focusout')
  focusOutHandler() {
    this.isFocused = false;
  }

  @HostListener('document:keydown', ['$event'])
  keyPressHandle(event: KeyboardEvent) {

    if (this.isFocused) {
      this.key = event.code;
      switch (this.key) {
        case 'Space':
          this.isOpen = true;
          break;
        case 'ArrowDown':
          if (this.options.length - 1 > this.selected) {
            this.selected = this.selected + 1;
          }
          break;
        case 'ArrowUp':
          if (this.selected > 0) {
            this.selected = this.selected - 1;
          }
          break;
        case 'Enter':
          if (this.selected > 0) {
            this.isSelectedValue = true;
            this.isOpen = false;
            this.onChangeCallback(this.selected);
            this.optSelect.emit(this.options[this.selected]);
          }
          break;
      }
    }

  }

  /**
  * option selection
  * @param {string} selectedOption - text
  * @param {number} idx - current index of item
  * @param {any} event - object
  */
  optionSelect(selectedOption: string, idx, e: any) {
    e.stopPropagation();
    this.selected = idx;
    this.isSelectedValue = true;
    // this.placeholder = '';
    this.isOpen = false;
    this.onChangeCallback(this.selected);
    this.optSelect.emit(selectedOption);
  }

  /**
  * toggle the dropdown
  * @param {any} event object
  */
  toggle(e: any) {
    e.stopPropagation();
    // close all previously opened dropdowns, before open
    const allElems = document.querySelectorAll('.dropdown-wrapper');
    for (let i = 0; i < allElems.length; i++) {
      allElems[i].classList.remove('is-open');
    }
    this.isOpen = !this.isOpen;
    if (this.selected >= 0) {
      document.querySelector('#li' + this.selected).scrollIntoView(true);
    }
  }

  /**
  * dropdown click on outside
  */
  @HostListener('document: click', ['$event'])
  onClick() {
    this.isOpen = false;
  }

  /**
   * Method implemented from ControlValueAccessor and set default selected value
   * @param {*} obj
   * @memberof DropdownComponent
   */
  writeValue(obj: any): void {
    if (obj && obj !== '') {
      this.isSelectedValue = true;
      this.selected = obj;
    } else {
      this.isSelectedValue = false;
    }
  }

  // From ControlValueAccessor interface
  registerOnChange(fn: any) {
    this.onChangeCallback = fn;
  }

  // From ControlValueAccessor interface
  registerOnTouched(fn: any) {
    this.onTouchedCallback = fn;
  }

  setDisabledState?(isDisabled: boolean): void {

  }

}

Usage

<app-dropdown formControlName="type" [options]="types" [placeholder]="captureData.type" [isReadOnly]="isReadOnly">
</app-dropdown>

Options must bind an array as follows. It can change based on the requirement.

types= [
        {
            "id": "1",
            "value": "Type 1"
        },
        {
             "id": "2",
             "value": "Type 2"
        },
        {
              "id": "3",
              "value": "Type 3"
        }] 

When to use: Java 8+ interface default method, vs. abstract method

Please think first of open/closed principle. The default methods in interfaces DO VIOLATE it. This is a bad feature in Java. It encourages bad design, bad architecture, low software quality. I would suggest to avoid using default methods completely.

Ask yourself a few questions: Why can't you put your methods to the abstract class? Would you need then more than one abstract class? Then think about what is your class responsible for. Are you sure all methods you are going to put to the single class really fulfill the same purpose? May be you will distinguish several purposes and will then split your class into several classes, for each purpose its own class.

Replace multiple whitespaces with single whitespace in JavaScript string

using a regular expression with the replace function does the trick:

string.replace(/\s/g, "")

Scanner only reads first word instead of line

The javadocs for Scanner answer your question

A Scanner breaks its input into tokens using a delimiter pattern, which by default matches whitespace.

You might change the default whitespace pattern the Scanner is using by doing something like

Scanner s = new Scanner();
s.useDelimiter("\n");

Remove from the beginning of std::vector

Two suggestions:

  1. Use std::deque instead of std::vector for better performance in your specific case and use the method std::deque::pop_front().
  2. Rethink (I mean: delete) the & in std::vector<ScanRule>& topPriorityRules;

How to make Python speak

PYTTSX3!

WHAT:

Pyttsx3 is a python module which is a modern clone of pyttsx, modified to work perfectly well in the latest versions of Python 3!

WHY:

It is 100% MULTI-PLATFORM and WORKS OFFLINE and IS ACTIVE/STILL BEING DEVELOPED and WORKS WITH ANY PYTHON VERSION

HOW:

It can be easily installed with pip install pyttsx3 and usage is the same as pyttsx:

import pyttsx3;
engine = pyttsx3.init();
engine.say("I will speak this text");
engine.runAndWait();

This is the best multi platform option!

Remove innerHTML from div


var $div = $('#desiredDiv');
$div.contents().remove();
$div.html('<p>This is new HTML.</p>');

That should work just fine.

Angular 2 - Using 'this' inside setTimeout

You need to use Arrow function ()=> ES6 feature to preserve this context within setTimeout.

// var that = this;                             // no need of this line
this.messageSuccess = true;

setTimeout(()=>{                           //<<<---using ()=> syntax
      this.messageSuccess = false;
 }, 3000);

Angular directives - when and how to use compile, controller, pre-link and post-link

How to declare the various functions?

Compile, Controller, Pre-link & Post-link

If one is to use all four function, the directive will follow this form:

myApp.directive( 'myDirective', function () {
    return {
        restrict: 'EA',
        controller: function( $scope, $element, $attrs, $transclude ) {
            // Controller code goes here.
        },
        compile: function compile( tElement, tAttributes, transcludeFn ) {
            // Compile code goes here.
            return {
                pre: function preLink( scope, element, attributes, controller, transcludeFn ) {
                    // Pre-link code goes here
                },
                post: function postLink( scope, element, attributes, controller, transcludeFn ) {
                    // Post-link code goes here
                }
            };
        }
    };  
});

Notice that compile returns an object containing both the pre-link and post-link functions; in Angular lingo we say the compile function returns a template function.

Compile, Controller & Post-link

If pre-link isn't necessary, the compile function can simply return the post-link function instead of a definition object, like so:

myApp.directive( 'myDirective', function () {
    return {
        restrict: 'EA',
        controller: function( $scope, $element, $attrs, $transclude ) {
            // Controller code goes here.
        },
        compile: function compile( tElement, tAttributes, transcludeFn ) {
            // Compile code goes here.
            return function postLink( scope, element, attributes, controller, transcludeFn ) {
                    // Post-link code goes here                 
            };
        }
    };  
});

Sometimes, one wishes to add a compile method, after the (post) link method was defined. For this, one can use:

myApp.directive( 'myDirective', function () {
    return {
        restrict: 'EA',
        controller: function( $scope, $element, $attrs, $transclude ) {
            // Controller code goes here.
        },
        compile: function compile( tElement, tAttributes, transcludeFn ) {
            // Compile code goes here.

            return this.link;
        },
        link: function( scope, element, attributes, controller, transcludeFn ) {
            // Post-link code goes here
        }

    };  
});

Controller & Post-link

If no compile function is needed, one can skip its declaration altogether and provide the post-link function under the link property of the directive's configuration object:

myApp.directive( 'myDirective', function () {
    return {
        restrict: 'EA',
        controller: function( $scope, $element, $attrs, $transclude ) {
            // Controller code goes here.
        },
        link: function postLink( scope, element, attributes, controller, transcludeFn ) {
                // Post-link code goes here                 
        },          
    };  
});

No controller

In any of the examples above, one can simply remove the controller function if not needed. So for instance, if only post-link function is needed, one can use:

myApp.directive( 'myDirective', function () {
    return {
        restrict: 'EA',
        link: function postLink( scope, element, attributes, controller, transcludeFn ) {
                // Post-link code goes here                 
        },          
    };  
});

Ruby on Rails form_for select field with class

You can also add prompt option like this.

<%= f.select(:object_field, ['Item 1', 'Item 2'], {include_blank: "Select something"}, { :class => 'my_style_class' }) %>

Docker-Compose can't connect to Docker Daemon

in my case it is because the ubuntu permission,

  1. List item

check permission by

docker info 

if they print problem permission, enter image description here then use

sudo chmod -R 777 /var/run/docker.sock

What is the standard way to add N seconds to datetime.time in Python?

You cannot simply add number to datetime because it's unclear what unit is used: seconds, hours, weeks...

There is timedelta class for manipulations with date and time. datetime minus datetime gives timedelta, datetime plus timedelta gives datetime, two datetime objects cannot be added although two timedelta can.

Create timedelta object with how many seconds you want to add and add it to datetime object:

>>> from datetime import datetime, timedelta
>>> t = datetime.now() + timedelta(seconds=3000)
>>> print(t)
datetime.datetime(2018, 1, 17, 21, 47, 13, 90244)

There is same concept in C++: std::chrono::duration.

Check if argparse optional argument is set or not

Very simple, after defining args variable by 'args = parser.parse_args()' it contains all data of args subset variables too. To check if a variable is set or no assuming the 'action="store_true" is used...

if args.argument_name:
   # do something
else:
   # do something else

Remove 'b' character do in front of a string literal in Python 3

This should do the trick:

pw_bytes.decode("utf-8")

How to host a Node.Js application in shared hosting

I installed Node.js on bluehost.com (a shared server) using:

wget <path to download file>
tar -xf <gzip file>
mv <gzip_file_dir> node

This will download the tar file, extract to a directory and then rename that directory to the name 'node' to make it easier to use.

then

./node/bin/npm install jt-js-sample

Returns:
npm WARN engine [email protected]: wanted: {"node":"0.10.x"} (current: {"node":"0.12.4","npm":"2.10.1"})
[email protected] node_modules/jt-js-sample
+-- [email protected] ([email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected])

I can now use the commands:

# ~/node/bin/node -v
v0.12.4

# ~/node/bin/npm -v
2.10.1

For security reasons, I have renamed my node directory to something else.

How to remove tab indent from several lines in IDLE?

In Jupyter Notebook,

 SHIFT+ TAB(to move left) and TAB(to move right) movement is perfectly working.

Parse JSON from HttpURLConnection object

You can get raw data using below method. BTW, this pattern is for Java 6. If you are using Java 7 or newer, please consider try-with-resources pattern.

public String getJSON(String url, int timeout) {
    HttpURLConnection c = null;
    try {
        URL u = new URL(url);
        c = (HttpURLConnection) u.openConnection();
        c.setRequestMethod("GET");
        c.setRequestProperty("Content-length", "0");
        c.setUseCaches(false);
        c.setAllowUserInteraction(false);
        c.setConnectTimeout(timeout);
        c.setReadTimeout(timeout);
        c.connect();
        int status = c.getResponseCode();

        switch (status) {
            case 200:
            case 201:
                BufferedReader br = new BufferedReader(new InputStreamReader(c.getInputStream()));
                StringBuilder sb = new StringBuilder();
                String line;
                while ((line = br.readLine()) != null) {
                    sb.append(line+"\n");
                }
                br.close();
                return sb.toString();
        }

    } catch (MalformedURLException ex) {
        Logger.getLogger(getClass().getName()).log(Level.SEVERE, null, ex);
    } catch (IOException ex) {
        Logger.getLogger(getClass().getName()).log(Level.SEVERE, null, ex);
    } finally {
       if (c != null) {
          try {
              c.disconnect();
          } catch (Exception ex) {
             Logger.getLogger(getClass().getName()).log(Level.SEVERE, null, ex);
          }
       }
    }
    return null;
}

And then you can use returned string with Google Gson to map JSON to object of specified class, like this:

String data = getJSON("http://localhost/authmanager.php");
AuthMsg msg = new Gson().fromJson(data, AuthMsg.class);
System.out.println(msg);

There is a sample of AuthMsg class:

public class AuthMsg {
    private int code;
    private String message;

    public int getCode() {
        return code;
    }
    public void setCode(int code) {
        this.code = code;
    }

    public String getMessage() {
        return message;
    }
    public void setMessage(String message) {
        this.message = message;
    }
}

JSON returned by http://localhost/authmanager.php must look like this:

{"code":1,"message":"Logged in"}

Regards

How to tell Jackson to ignore a field during serialization if its value is null?

Just to expand on the other answers - if you need to control the omission of null values on a per-field basis, annotate the field in question (or alternatively annotate the field's 'getter').

example - here only fieldOne will be ommitted from json if it is null. fieldTwo will always be included regardless of if it is null.

public class Foo {

    @JsonInclude(JsonInclude.Include.NON_NULL) 
    private String fieldOne;

    private String fieldTwo;
}

To omit all null values in the class as a default, annotate the class. Per-field/getter annotations can still be used to override this default if necessary.

example - here fieldOne and fieldTwo will be ommitted from json if they are null, respectively, because this is the default set by the class annotation. fieldThree however will override the default and will always be included, because of the annotation on the field.

@JsonInclude(JsonInclude.Include.NON_NULL)
public class Foo {

    private String fieldOne;

    private String fieldTwo;

    @JsonInclude(JsonInclude.Include.ALWAYS)
    private String fieldThree;
}

UPDATE

The above is for Jackson 2. For earlier versions of Jackson you need to use:

@JsonSerialize(include=JsonSerialize.Inclusion.NON_NULL) 

instead of

@JsonInclude(JsonInclude.Include.NON_NULL)

If this update is useful, please upvote ZiglioUK's answer below, it pointed out the newer Jackson 2 annotation long before I updated my answer to use it!

What is the best way to search the Long datatype within an Oracle database?

You can't search LONGs directly. LONGs can't appear in the WHERE clause. They can appear in the SELECT list though so you can use that to narrow down the number of rows you'd have to examine.

Oracle has recommended converting LONGs to CLOBs for at least the past 2 releases. There are fewer restrictions on CLOBs.

You are trying to add a non-nullable field 'new_field' to userprofile without a default

You need to provide a default value:

new_field = models.CharField(max_length=140, default='SOME STRING')

Can't concat bytes to str

subprocess.check_output() returns a bytestring.

In Python 3, there's no implicit conversion between unicode (str) objects and bytes objects. If you know the encoding of the output, you can .decode() it to get a string, or you can turn the \n you want to add to bytes with "\n".encode('ascii')

Min and max value of input in angular4 application

You can control with a change event if the input is within your range, if it is not in the range you assign 0.

<md-input-container>
  <input type="number" 
    maxlength="3" 
    min="0" 
    max="100" 
    required 
    mdInput 
    placeholder="Charge" 
    [(ngModel)]="rateInput"
    (change)= "rateInput < 0 ? rateInput = 0 : rateInput; rateInput > 100 ? rateInput = 0 : rateIntput;"
    name="rateInput">
  <md-error>Required field</md-error>
</md-input-container>

Control flow in T-SQL SP using IF..ELSE IF - are there other ways?

Also you can try to formulate your answer in the form of a SELECT CASE Statement. You can then later create simple if then's that use your results if needed as you have narrowed down the possibilities.

SELECT @Result =   
CASE @inputParam   
WHEN 1 THEN 1   
WHEN 2 THEN 2   
WHEN 3 THEN 1   
ELSE 4   
END  

IF @Result = 1   
BEGIN  
...  
END  

IF @Result = 2   
BEGIN   
....  
END  

IF @Result = 4   
BEGIN   
//Error handling code   
END   

How can I render Partial views in asp.net mvc 3?

<%= Html.Partial("PartialName", Model) %>

Is it possible to open developer tools console in Chrome on Android phone?

Please do yourself a favor and just hit the easy button:

download Web Inspector (Open Source) from the Play store.

A CAVEAT: ATTOW, console output does not accept rest params! I.e. if you have something like this:

console.log('one', 'two', 'three');

you will only see

one

logged to the console. You'll need to manually wrap the params in an Array and join, like so:

console.log([ 'one', 'two', 'three' ].join(' '));

to see the expected output.

But the app is open source! A patch may be imminent! The patcher could even be you!

How to initialize/instantiate a custom UIView class with a XIB file in Swift

And this is the answer of Frederik on Swift 3.0

/*
 Usage:
 - make your CustomeView class and inherit from this one
 - in your Xib file make the file owner is your CustomeView class
 - *Important* the root view in your Xib file must be of type UIView
 - link all outlets to the file owner
 */
@IBDesignable
class NibLoadingView: UIView {

    @IBOutlet weak var view: UIView!

    override init(frame: CGRect) {
        super.init(frame: frame)
        nibSetup()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        nibSetup()
    }

    private func nibSetup() {
        backgroundColor = .clear

        view = loadViewFromNib()
        view.frame = bounds
        view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        view.translatesAutoresizingMaskIntoConstraints = true

        addSubview(view)
    }

    private func loadViewFromNib() -> UIView {
        let bundle = Bundle(for: type(of: self))
        let nib = UINib(nibName: String(describing: type(of: self)), bundle: bundle)
        let nibView = nib.instantiate(withOwner: self, options: nil).first as! UIView

        return nibView
    }
}

PHP expects T_PAAMAYIM_NEKUDOTAYIM?

This just happened to me in a string assignment using double quotes. I was missing a closing curly on a POST variable...

"for {$_POST['txtName'] on $date";

should have been

"for {$_POST['txtName']} on $date";

I can't explain why. I mean, I see the error that would break the code but I don't see why it references a class error.

How to end C++ code

Either return a value from your main or use the exit function. Both take an int. It doesn't really matter what value you return unless you have an external process watching for the return value.

Errors: Data path ".builders['app-shell']" should have required property 'class'

I had this issue, this is how i have solved it. The problem mostly is that your Angular version is not supporting your Node.js version for the build. So the best solution is to upgrade your Node.js to the most current stable one.

For a clean upgrade of Node.js, i advise using n. if you are using Mac.

npm install -g n
npm cache clean -f
sudo n stable
npm update -g

and now check that you are updated:

node -v
npm -v

For more details, check this link: here

How to get instance variables in Python?

Both the Vars() and dict methods will work for the example the OP posted, but they won't work for "loosely" defined objects like:

class foo:
  a = 'foo'
  b = 'bar'

To print all non-callable attributes, you can use the following function:

def printVars(object):
    for i in [v for v in dir(object) if not callable(getattr(object,v))]:
        print '\n%s:' % i
        exec('print object.%s\n\n') % i

Re-ordering factor levels in data frame

Assuming your dataframe is mydf:

mydf$task <- factor(mydf$task, levels = c("up", "down", "left", "right", "front", "back"))

Clearing an input text field in Angular2

Method 1.

Using `ngModel`.

@Component({
  selector: 'my-app',
  template: `
    <div>
      <input type="text" placeholder="Search..."  [(ngModel)]="searchValue">
      <button (click)="clearSearch()">Clear</button>
    </div>
  `,
})
export class App {
  searchValue:string = '';
  clearSearch() {
    this.searchValue = null;
  }
}

Plunker code: Plunker1

Method 2.

Using null value instead of empty quotation marks.

@Component({
  selector: 'my-app',
  template: `
    <div>
      <input type="text" placeholder="Search..." [value]="searchValue">
      <button (click)="clearSearch()">Clear</button>
    </div>
  `,
})
export class App {
  searchValue:string = '';
  clearSearch() {
    this.searchValue = null;
  }
}

Plunker code: Plunker2

Angular 6: How to set response type as text while making http call

You should not use those headers, the headers determine what kind of type you are sending, and you are clearly sending an object, which means, JSON.

Instead you should set the option responseType to text:

addToCart(productId: number, quantity: number): Observable<any> {
  const headers = new HttpHeaders().set('Content-Type', 'text/plain; charset=utf-8');

  return this.http.post(
    'http://localhost:8080/order/addtocart', 
    { dealerId: 13, createdBy: "-1", productId, quantity }, 
    { headers, responseType: 'text'}
  ).pipe(catchError(this.errorHandlerService.handleError));
}

Express.js: how to get remote client address

Particularly for node, the documentation for the http server component, under event connection says:

[Triggered] when a new TCP stream is established. [The] socket is an object of type net.Socket. Usually users will not want to access this event. In particular, the socket will not emit readable events because of how the protocol parser attaches to the socket. The socket can also be accessed at request.connection.

So, that means request.connection is a socket and according to the documentation there is indeed a socket.remoteAddress attribute which according to the documentation is:

The string representation of the remote IP address. For example, '74.125.127.100' or '2001:4860:a005::68'.

Under express, the request object is also an instance of the Node http request object, so this approach should still work.

However, under Express.js the request already has two attributes: req.ip and req.ips

req.ip

Return the remote address, or when "trust proxy" is enabled - the upstream address.

req.ips

When "trust proxy" is true, parse the "X-Forwarded-For" ip address list and return an array, otherwise an empty array is returned. For example if the value were "client, proxy1, proxy2" you would receive the array ["client", "proxy1", "proxy2"] where "proxy2" is the furthest down-stream.

It may be worth mentioning that, according to my understanding, the Express req.ip is a better approach than req.connection.remoteAddress, since req.ip contains the actual client ip (provided that trusted proxy is enabled in express), whereas the other may contain the proxy's IP address (if there is one).

That is the reason why the currently accepted answer suggests:

var ip = req.headers['x-forwarded-for'] || req.connection.remoteAddress;

The req.headers['x-forwarded-for'] will be the equivalent of express req.ip.

How to get the PID of a process by giving the process name in Mac OS X ?

You can try this

pid=$(ps -o pid=,comm= | grep -m1 $procname | cut -d' ' -f1)

"CSV file does not exist" for a filename with embedded quotes

I also experienced the same problem I solved as follows:

dataset = pd.read_csv('C:\\Users\\path\\to\\file.csv')

Sass nth-child nesting

I'd be careful about trying to get too clever here. I think it's confusing as it is and using more advanced nth-child parameters will only make it more complicated. As for the background color I'd just set that to a variable.

Here goes what I came up with before I realized trying to be too clever might be a bad thing.

#romtest {
 $bg: #e5e5e5;
 .detailed {
    th {
      &:nth-child(-2n+6) {
        background-color: $bg;
      }
    }
    td {
      &:nth-child(3n), &:nth-child(2), &:nth-child(7) {
        background-color: $bg;
      }
      &.last {
        &:nth-child(-2n+4){
          background-color: $bg;
        }
      }
    }
  }
}

and here is a quick demo: http://codepen.io/anon/pen/BEImD

----EDIT----

Here's another approach to avoid retyping background-color:

#romtest {
  %highlight {
    background-color: #e5e5e5; 
  }
  .detailed {
    th {
      &:nth-child(-2n+6) {
        @extend %highlight;
      }
    }

    td {
      &:nth-child(3n), &:nth-child(2), &:nth-child(7) {
        @extend %highlight;
      }
      &.last {
        &:nth-child(-2n+4){
          @extend %highlight;
        }
      }
    }
  }
}

Unsupported method: BaseConfig.getApplicationIdSuffix()

I also faced the same issue and got a solution very similar:

  1. Changing the classpath to classpath 'com.android.tools.build:gradle:2.3.2'

    Image after adding the classpath

  2. A new message indicating to Update Build Tool version, so just click that message to update. Update

Error Code: 1290. The MySQL server is running with the --secure-file-priv option so it cannot execute this statement

If you changed my.ini and restarted mysql and you still get this error please check your file path and replace "\" to "/". I solved my proplem after replacing.

Creating a search form in PHP to search a database?

try this out let me know what happens.

Form:

<form action="form.php" method="post"> 
Search: <input type="text" name="term" /><br /> 
<input type="submit" value="Submit" /> 
</form> 

Form.php:

$term = mysql_real_escape_string($_REQUEST['term']);    

$sql = "SELECT * FROM liam WHERE Description LIKE '%".$term."%'";
$r_query = mysql_query($sql);

while ($row = mysql_fetch_array($r_query)){ 
echo 'Primary key: ' .$row['PRIMARYKEY']; 
echo '<br /> Code: ' .$row['Code']; 
echo '<br /> Description: '.$row['Description']; 
echo '<br /> Category: '.$row['Category']; 
echo '<br /> Cut Size: '.$row['CutSize'];  
} 

Edit: Cleaned it up a little more.

Final Cut (my test file):

<?php
$db_hostname = 'localhost';
$db_username = 'demo';
$db_password = 'demo';
$db_database = 'demo';

// Database Connection String
$con = mysql_connect($db_hostname,$db_username,$db_password);
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }

mysql_select_db($db_database, $con);
?>

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="utf-8" />
        <title></title>
    </head>
    <body>
<form action="" method="post">  
Search: <input type="text" name="term" /><br />  
<input type="submit" value="Submit" />  
</form>  
<?php
if (!empty($_REQUEST['term'])) {

$term = mysql_real_escape_string($_REQUEST['term']);     

$sql = "SELECT * FROM liam WHERE Description LIKE '%".$term."%'"; 
$r_query = mysql_query($sql); 

while ($row = mysql_fetch_array($r_query)){  
echo 'Primary key: ' .$row['PRIMARYKEY'];  
echo '<br /> Code: ' .$row['Code'];  
echo '<br /> Description: '.$row['Description'];  
echo '<br /> Category: '.$row['Category'];  
echo '<br /> Cut Size: '.$row['CutSize'];   
}  

}
?>
    </body>
</html>

OpenCV resize fails on large image with "error: (-215) ssize.area() > 0 in function cv::resize"

I am having OpenCV version 3.4.3 on MacOS. I was getting the same error as above.

I changed my code from

frame = cv2.resize(frame, (0,0), fx=0.5, fy=0.5)   

to

frame = cv2.resize(frame, None, fx=0.5, fy=0.5)    

Now its working fine for me.

How do I set a cookie on HttpClient's HttpRequestMessage

The accepted answer is the correct way to do this in most cases. However, there are some situations where you want to set the cookie header manually. Normally if you set a "Cookie" header it is ignored, but that's because HttpClientHandler defaults to using its CookieContainer property for cookies. If you disable that then by setting UseCookies to false you can set cookie headers manually and they will appear in the request, e.g.

var baseAddress = new Uri("http://example.com");
using (var handler = new HttpClientHandler { UseCookies = false })
using (var client = new HttpClient(handler) { BaseAddress = baseAddress })
{
    var message = new HttpRequestMessage(HttpMethod.Get, "/test");
    message.Headers.Add("Cookie", "cookie1=value1; cookie2=value2");
    var result = await client.SendAsync(message);
    result.EnsureSuccessStatusCode();
}

Hibernate: Automatically creating/updating the db tables based on entity classes

You might try changing this line in your persistence.xml from

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

to:

<property name="hibernate.hbm2ddl.auto" value="update"/>

This is supposed to maintain the schema to follow any changes you make to the Model each time you run the app.

Got this from JavaRanch

How to avoid HTTP error 429 (Too Many Requests) python

In many cases, continuing to scrape data from a website even when the server is requesting you not to is unethical. However, in the cases where it isn't, you can utilize a list of public proxies in order to scrape a website with many different IP addresses.

Get path to execution directory of Windows Forms application

In VB.NET

Dim directory as String = My.Application.Info.DirectoryPath

In C#

string directory = AppDomain.CurrentDomain.BaseDirectory;

Android Drawing Separator/Divider Line in Layout?

Simple solution

just add this code in your layout and replace 'Id_of__view_present_above' to the id of the view, below which you need the divider.

<TextView
  android:layout_width="match_parent"
  android:layout_height="1dp"
  android:background="#c0c0c0"
  android:id="@+id/your_id"
  android:layout_marginTop="16dp" 
  android:layout_below="@+id/Id_of__view_present_above"
/>

How do you round UP a number in Python?

My share

I have tested print(-(-101 // 5)) = 21 given example above.

Now for rounding up:

101 * 19% = 19.19

I can not use ** so I spread the multiply to division:

(-(-101 //(1/0.19))) = 20

MySQL joins and COUNT(*) from another table

SELECT DISTINCT groups.id, 
       (SELECT COUNT(*) FROM group_members
        WHERE member_id = groups.id) AS memberCount
FROM groups

POST request not allowed - 405 Not Allowed - nginx, even with headers included

This is the real proxy redirection to the intended server.

server {
  listen          80;
  server_name     localhost;
location / {
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-NginX-Proxy true;
    proxy_pass http://xx.xxx.xxx.xxx/;
    proxy_redirect off;
    proxy_set_header Host $host;

  }
}

ERROR! MySQL manager or server PID file could not be found! QNAP

I know this is an older post, but I ran into the ERROR! MySQL server PID file could not be found! when trying to start MySQL after making an update to my.cnf file. I did the following to resolve the issue:

  1. Deleted my experimental update to my.cnf

  2. Deleted the .net.pid and .net.err files.

delete /usr/local/var/mysql/**<YourUserName>**-MBP.airstreamcomm.net.*
  1. Ensured all MySQL processes are stopped.
ps -ax | grep mysql
kill **<process id>**
  1. Started MySQL server as normal.
mysql.server start

Is it possible to set UIView border properties from interface builder?

Similar answer to iHulk's one, but in Swift

Add a file named UIView.swift in your project (or just paste this in any file) :

import UIKit

@IBDesignable extension UIView {
    @IBInspectable var borderColor: UIColor? {
        set {
            layer.borderColor = newValue?.cgColor
        }
        get {
            guard let color = layer.borderColor else {
                return nil
            }
            return UIColor(cgColor: color)
        }
    }
    @IBInspectable var borderWidth: CGFloat {
        set {
            layer.borderWidth = newValue
        }
        get {
            return layer.borderWidth
        }
    }
    @IBInspectable var cornerRadius: CGFloat {
        set {
            layer.cornerRadius = newValue
            clipsToBounds = newValue > 0
        }
        get {
            return layer.cornerRadius
        }
    }
}

Then this will be available in Interface Builder for every button, imageView, label, etc. in the Utilities Panel > Attributes Inspector :

Attributes Inspector

Note: the border will only appear at runtime.

How to bind event listener for rendered elements in Angular 2?

import { AfterViewInit, Component, ElementRef} from '@angular/core';

constructor(private elementRef:ElementRef) {}

ngAfterViewInit() {
  this.elementRef.nativeElement.querySelector('my-element')
                                .addEventListener('click', this.onClick.bind(this));
}

onClick(event) {
  console.log(event);
}

Output (echo/print) everything from a PHP Array

For nice & readable results, use this:

function printVar($var) {
    echo '<pre>';
    var_dump($var); 
    echo '</pre>';
}

The above function will preserve the original formatting, making it (more)readable in a web browser.

Qt Creator color scheme

Linux, Qt Creator >= 3.4:

You could edit theese themes:

/usr/share/qtcreator/themes/default.creatortheme
/usr/share/qtcreator/themes/dark.creatortheme

How to make an introduction page with Doxygen

I tried all the above with v 1.8.13 to no avail. What worked for me (on macOS) was to use the doxywizard->Expert tag to fill the USE_MD_FILE_AS_MAINPAGE setting.

It made the following changes to my Doxyfile:

USE_MDFILE_AS_MAINPAGE = ../README.md
...
INPUT                  = ../README.md \
                         ../sdk/include \
                         ../sdk/src

Note the line termination for INPUT, I had just been using space as a separator as specified in the documentation. AFAICT this is the only change between the not-working and working version of the Doxyfile.

xcode library not found

For me it was a silly thing: my mac uploaded the file into iCloud, and that is why Xcode did not find it.

If you turn off the automatic upload, it wont happen again.

jasmine: Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL

Instead of

beforeEach(() => {..

use

beforeEach(fakeAsync(() => {..

What is the difference between Cloud, Grid and Cluster?

There's some pretty good answers here but I want to elaborate on all topics:

Cloud: shailesh's answer is awesome, nothing to add there! Basically, An application that's served seamlessly over the network can be considered a Cloud application. Cloud isn't a new invention and it's very similar to Grid computing, but it's more of a buzzword with the spike of recent popularity.

Grid: Grid is defined as a large collection as machines connected by a private network and offers a set of services to users, it acts as a sort of supercomputer by sharing processing power across the machines. Source: Tenenbaum, Andrew.

Cluster: A cluster is different from those two. Clusters are two or more computers who share a network connection that acts as a heart-beat. Clusters are configurable in Active-Active or Active-Passive ways. Active-Active being that each computer runs it's own set of services (Say, one runs a SQL instance, the other runs a web server) and they share some resources such as storage. If one of the computers in a cluster goes down the service fails over to the other node and almost seamlessly starts running there. Active-Passive is similar, but only one machine runs these services and only takes over once there's a failure.

Eliminate extra separators below UITableView

Try this

self.tables.tableFooterView = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 320.0f, 10.0f)];

React Js: Uncaught (in promise) SyntaxError: Unexpected token < in JSON at position 0

I was getting the same error, for me, it was because API was just returning a string however in fetch call I was expecting json :

response => response.json()

Returning json from API resolved the issue for me, if your API is not supposed to return json then simply don't do response.json()

Plot multiple columns on the same graph in R

The easiest is to convert your data to a "tall" format.

s <- 
"A       B        C       G       Xax
0.451   0.333   0.034   0.173   0.22        
0.491   0.270   0.033   0.207   0.34    
0.389   0.249   0.084   0.271   0.54    
0.425   0.819   0.077   0.281   0.34
0.457   0.429   0.053   0.386   0.53    
0.436   0.524   0.049   0.249   0.12    
0.423   0.270   0.093   0.279   0.61    
0.463   0.315   0.019   0.204   0.23
"
d <- read.delim(textConnection(s), sep="")

library(ggplot2)
library(reshape2)
d <- melt(d, id.vars="Xax")

# Everything on the same plot
ggplot(d, aes(Xax,value, col=variable)) + 
  geom_point() + 
  stat_smooth() 

# Separate plots
ggplot(d, aes(Xax,value)) + 
  geom_point() + 
  stat_smooth() +
  facet_wrap(~variable)

BigDecimal setScale and round

One important point that is alluded to but not directly addressed is the difference between "precision" and "scale" and how they are used in the two statements. "precision" is the total number of significant digits in a number. "scale" is the number of digits to the right of the decimal point.

The MathContext constructor only accepts precision and RoundingMode as arguments, and therefore scale is never specified in the first statement.

setScale() obviously accepts scale as an argument, as well as RoundingMode, however precision is never specified in the second statement.

If you move the decimal point one place to the right, the difference will become clear:

// 1.
new BigDecimal("35.3456").round(new MathContext(4, RoundingMode.HALF_UP));
//result = 35.35
// 2.
new BigDecimal("35.3456").setScale(4, RoundingMode.HALF_UP);
// result = 35.3456

How to use Lambda in LINQ select statement

Why not just use all Lambda syntax?

database.Stores.Where(s => s.CompanyID == curCompany.ID)
               .Select(s => new SelectListItem
                   {
                       Value = s.Name,
                       Text = s.ID
                   });