How to go from one page to another page using javascript?

You cannot sanely depend on client side JavaScript to determine if user credentials are correct. The browser (and all code that executes that) is under the control of the user, not you, so it is not trustworthy.

The username and password need to be entered using a form. The OK button will be a submit button. The action attribute must point to a URL which will be handled by a program that checks the credentials.

This program could be written in JavaScript, but how you go about that would depend on which server side JavaScript engine you were using. Note that SSJS is not a mainstream technology so if you really want to use it, you would have to use specialised hosting or admin your own server.

(Half a decade later and SSJS is much more common thanks to Node.js, it is still fairly specialised though).

If you want to redirect afterwards, then the program needs to emit an HTTP Location header.

Note that you need to check the credentials are OK (usually by storing a token, which isn't the actual password, in a cookie) before outputting any private page. Otherwise anyone could get to the private pages by knowing the URL (and thus bypassing the login system).

Download File Using Javascript/jQuery

I know I'm late for the party, but I'd like to share my solution which is variation of Imagine Breaker's solution above. I tried to use his solution, because his solution seems most simple and easy to me. But like other said, it didn't work for some browsers, so I put some variation on it by using jquery.

Hope this could help someone out there.

function download(url) {
  var link = document.createElement("a");
  $(link).click(function(e) {
    e.preventDefault();
    window.location.href = url;
  });
  $(link).click();
}

How to serve up a JSON response using Go?

You may use this package renderer, I have written to solve this kind of problem, it's a wrapper to serve JSON, JSONP, XML, HTML etc.

Calling stored procedure with return value

I know this is old, but i stumbled on it with Google.

If you have a return value in your stored procedure say "Return 1" - not using output parameters.

You can do the following - "@RETURN_VALUE" is silently added to every command object. NO NEED TO EXPLICITLY ADD

    cmd.ExecuteNonQuery();
    rtn = (int)cmd.Parameters["@RETURN_VALUE"].Value;

How to change title of Activity in Android?

If you want to set title in Java file, then write in your activity onCreate

setTitle("Your Title");

if you want to in Manifest then write

    <activity
        android:name=".MainActivity"
        android:label="Your Title" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

I got error "The DELETE statement conflicted with the REFERENCE constraint"

Have you considered applying ON DELETE CASCADE where relevant?

How to handle Uncaught (in promise) DOMException: The play() request was interrupted by a call to pause()

I second Shobhit Verma, and I have a little note to add : in his post he told that in Chrome (Opera for myself) the players need to be muted in order for the autoplay to succeed... And ironically, if you elevate the volume after load, it will still play... It's like all those anti-pop-ups mechanic that ignore invisible frame slid into your code... php-echoed html and javascript is : 10-second setTimeout onLoad of body tag that rises volume to maximum, video with autoplay and muted='muted' (yeah that $muted_code part is = "muted='muted")

echo "<body style='margin-bottom:0pt; margin-top:0pt; margin-left:0pt; margin-right:0pt' onLoad=\"setTimeout(function() {var vid = document.getElementById('hourglass_video'); vid.volume = 1.0;},10000);\">";
    echo "<div id='hourglass_container' width='100%' height='100%' align='center' style='text-align:right; vertical-align:bottom'>";
    echo "<video autoplay {$muted_code}title=\"!!! Pausing this video will immediately end your turn!!!\" oncontextmenu=\"dont_stop_hourglass(event);\" onPause=\"{$action}\" id='hourglass_video' frameborder='0' style='width:95%; margin-top:28%'>";

Can not deserialize instance of java.lang.String out of START_OBJECT token

Resolved the problem using Jackson library. Prints are called out of Main class and all POJO classes are created. Here is the code snippets.

MainClass.java

public class MainClass {
  public static void main(String[] args) throws JsonParseException, 
       JsonMappingException, IOException {

String jsonStr = "{\r\n" + "    \"id\": 2,\r\n" + " \"socket\": \"0c317829-69bf- 
             43d6-b598-7c0c550635bb\",\r\n"
            + " \"type\": \"getDashboard\",\r\n" + "    \"data\": {\r\n"
            + "     \"workstationUuid\": \"ddec1caa-a97f-4922-833f- 
            632da07ffc11\"\r\n" + " },\r\n"
            + " \"reply\": true\r\n" + "}";

    ObjectMapper mapper = new ObjectMapper();

    MyPojo details = mapper.readValue(jsonStr, MyPojo.class);

    System.out.println("Value for getFirstName is: " + details.getId());
    System.out.println("Value for getLastName  is: " + details.getSocket());
    System.out.println("Value for getChildren is: " + 
      details.getData().getWorkstationUuid());
    System.out.println("Value for getChildren is: " + details.getReply());

}

MyPojo.java

public class MyPojo {
    private String id;

    private Data data;

    private String reply;

    private String socket;

    private String type;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public Data getData() {
        return data;
    }

    public void setData(Data data) {
        this.data = data;
    }

    public String getReply() {
        return reply;
    }

    public void setReply(String reply) {
        this.reply = reply;
    }

    public String getSocket() {
        return socket;
    }

    public void setSocket(String socket) {
        this.socket = socket;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    } 
}

Data.java

public class Data {
    private String workstationUuid;

    public String getWorkstationUuid() {
        return workstationUuid;
    }

    public void setWorkstationUuid(String workstationUuid) {
        this.workstationUuid = workstationUuid;
    }   
}

RESULTS:

Value for getFirstName is: 2
Value for getLastName  is: 0c317829-69bf-43d6-b598-7c0c550635bb
Value for getChildren is: ddec1caa-a97f-4922-833f-632da07ffc11
Value for getChildren is: true

How can I remove an SSH key?

Note that there are at least two bug reports for ssh-add -d/-D not removing keys:

The exact issue is:

ssh-add -d/-D deletes only manually added keys from gnome-keyring.
There is no way to delete automatically added keys.
This is the original bug, and it's still definitely present.

So, for example, if you have two different automatically-loaded ssh identities associated with two different GitHub accounts -- say for work and for home -- there's no way to switch between them. GitHubtakes the first one which matches, so you always appear as your 'home' user to GitHub, with no way to upload things to work projects.

Allowing ssh-add -d to apply to automatically-loaded keys (and ssh-add -t X to change the lifetime of automatically-loaded keys), would restore the behavior most users expect.

More precisely, about the issue:

The culprit is gpg-keyring-daemon:

It subverts the normal operation of ssh-agent, mostly just so that it can pop up a pretty box into which you can type the passphrase for an encrypted ssh key.

And it paws through your .ssh directory, and automatically adds any keys it finds to your agent.
And it won't let you delete those keys.

How do we hate this? Let's not count the ways -- life's too short.

The failure is compounded because newer ssh clients automatically try all the keys in your ssh-agent when connecting to a host.
If there are too many, the server will reject the connection.
And since gnome-keyring-daemon has decided for itself how many keys you want your ssh-agent to have, and has autoloaded them, AND WON'T LET YOU DELETE THEM, you're toast.

This bug is still confirmed in Ubuntu 14.04.4, as recently as two days ago (August 21st, 2014)

A possible workaround:

Do ssh-add -D to delete all your manually added keys. This also locks the automatically added keys, but is not much use since gnome-keyring will ask you to unlock them anyways when you try doing a git push.

Navigate to your ~/.ssh folder and move all your key files except the one you want to identify with into a separate folder called backup. If necessary you can also open seahorse and delete the keys from there.
Now you should be able to do git push without a problem.

Another workaround:

What you really want to do is to turn off gpg-keyring-daemon altogether.
Go to System --> Preferences --> Startup Applications, and unselect the "SSH Key Agent (Gnome Keyring SSH Agent)" box -- you'll need to scroll down to find it.

You'll still get an ssh-agent, only now it will behave sanely: no keys autoloaded, you run ssh-add to add them, and if you want to delete keys, you can. Imagine that.

This comments actually suggests:

The solution is to keep gnome-keyring-manager from ever starting up, which was strangely difficult by finally achieved by removing the program file's execute permission.

Ryan Lue adds another interesting corner case in the comments:

In case this helps anyone: I even tried deleting the id_rsa and id_rsa.pub files altogether, and the key was still showing up.

Turns out gpg-agent was caching them in a ~/.gnupg/sshcontrol file; I had to manually delete them from there.

That is the case when the keygrip has been added as in here.

Keyboard shortcut to paste clipboard content into command prompt window (Win XP)

If you use the clipboard manager Ditto (open source, gratis), you can simply use the shortcut to paste from Ditto, and it will paste the clipboard in CMD for you.

How to find the privileges and roles granted to a user in Oracle?

The only visible result I was able to understand was first to connect with the user I wanted to get the rights, then with the following query:

SELECT GRANTEE, PRIVILEGE, TABLE_NAME FROM USER_TAB_PRIVS;

How to use JUnit to test asynchronous processes

IMHO it's bad practice to have unit tests create or wait on threads, etc. You'd like these tests to run in split seconds. That's why I'd like to propose a 2-step approach to testing async processes.

Test that your async process is submitted properly. You can mock the object that accepts your async requests and make sure that the submitted job has correct properties, etc.
Test that your async callbacks are doing the right things. Here you can mock out the originally submitted job and assume it's initialized properly and verify that your callbacks are correct.

Node.js: Gzip compression?

How about this?

node-compress
A streaming compression / gzip module for node.js
To install, ensure that you have libz installed, and run:
node-waf configure
node-waf build
This will put the compress.node binary module in build/default.
...

.mp4 file not playing in chrome

I too had the same issue. I changed the codec to H264-MPEG-4 AVC and the videos started working in HTML5/Chrome.

Option selected in converter: H264-MPEG-4 AVC, Codec visible in VLC player: H264-MPEG-4 AVC (part 10) (avc1)

Hope it helps...

What are forward declarations in C++?

The term "forward declaration" in C++ is mostly only used for class declarations. See (the end of) this answer for why a "forward declaration" of a class really is just a simple class declaration with a fancy name.

In other words, the "forward" just adds ballast to the term, as any declaration can be seen as being forward in so far as it declares some identifier before it is used.

(As to what is a declaration as opposed to a definition, again see What is the difference between a definition and a declaration?)

Evaluate list.contains string in JSTL

${fn:contains({1,2,4,8}, 2)}

  <c:if test = "${fn:contains(theString, 'test')}">
     <p>Found test string<p>
  </c:if>

  <c:if test = "${fn:contains(theString, 'TEST')}">
     <p>Found TEST string<p>
  </c:if>

Undefined function mysql_connect()

There must be some syntax error. Copy/paste this code and see if it works:

<?php
    $link = mysql_connect('localhost', 'root', '');
    if (!$link) {
        die('Could not connect:' . mysql_error());
    }
    echo 'Connected successfully';
    ?

I had the same error message. It turns out I was using the msql_connect() function instead of mysql_connect().

How to import cv2 in python3?

The best way is to create a virtual env. first and then do pip install , everything will work fine

how to sort order of LEFT JOIN in SQL query?

try this out:

   SELECT
      `userName`,
      `carPrice`
   FROM `users`
   LEFT JOIN `cars`
   ON cars.belongsToUser=users.id
   WHERE `id`='4'
   ORDER BY `carPrice` DESC
   LIMIT 1

Felix

What is the difference between application server and web server?

In short,
The web server is a server that serves static web pages to users via HTTP requests.
The application server is a server that hosts the business logic for a system.
It often hosts both long-running/batch processes and/or interop services not meant for human consumption (REST/JSON services, SOAP, RPC, etc).

Get element from within an iFrame

None of the other answers were working for me. I ended up creating a function within my iframe that returns the object I was looking for:

function getElementWithinIframe() {
    return document.getElementById('copy-sheet-form');
}

Then you call that function like so to retrieve the element:

var el = document.getElementById("iframeId").contentWindow.functionNameToCall();

How to kill a child process by the parent process?

In the parent process, fork()'s return value is the process ID of the child process. Stuff that value away somewhere for when you need to terminate the child process. fork() returns zero(0) in the child process.

When you need to terminate the child process, use the kill(2) function with the process ID returned by fork(), and the signal you wish to deliver (e.g. SIGTERM).

Remember to call wait() on the child process to prevent any lingering zombies.

jQuery Event : Detect changes to the html/text of a div

You are looking for MutationObserver or Mutation Events. Neither are supported everywhere nor are looked upon too fondly by the developer world.

If you know (and can make sure that) the div's size will change, you may be able to use the crossbrowser resize event.

How to create a directory in Java?

Though this question has been answered. I would like to put something extra, i.e. if there is a file exist with the directory name that you are trying to create than it should prompt an error. For future visitors.

public static void makeDir()
{
    File directory = new File(" dirname ");
    if (directory.exists() && directory.isFile())
    {
        System.out.println("The dir with name could not be" +
        " created as it is a normal file");
    }
    else
    {
        try
        {
            if (!directory.exists())
            {
                directory.mkdir();
            }
            String username = System.getProperty("user.name");
            String filename = " path/" + username + ".txt"; //extension if you need one

        }
        catch (IOException e)
        {
            System.out.println("prompt for error");
        }
    }
}

How do I view executed queries within SQL Server Management Studio?

More clear query, targeting Studio sql queries is :

SELECT text  FROM sys.dm_exec_sessions es
  INNER JOIN sys.dm_exec_connections ec
      ON es.session_id = ec.session_id
  CROSS APPLY sys.dm_exec_sql_text(ec.most_recent_sql_handle) 
  where program_name like '%Query'

Custom HTTP headers : naming conventions

The question bears re-reading. The actual question asked is not similar to vendor prefixes in CSS properties, where future-proofing and thinking about vendor support and official standards is appropriate. The actual question asked is more akin to choosing URL query parameter names. Nobody should care what they are. But name-spacing the custom ones is a perfectly valid -- and common, and correct -- thing to do.

Rationale:
It is about conventions among developers for custom, application-specific headers -- "data relevant to their account" -- which have nothing to do with vendors, standards bodies, or protocols to be implemented by third parties, except that the developer in question simply needs to avoid header names that may have other intended use by servers, proxies or clients. For this reason, the "X-Gzip/Gzip" and "X-Forwarded-For/Forwarded-For" examples given are moot. The question posed is about conventions in the context of a private API, akin to URL query parameter naming conventions. It's a matter of preference and name-spacing; concerns about "X-ClientDataFoo" being supported by any proxy or vendor without the "X" are clearly misplaced.

There's nothing special or magical about the "X-" prefix, but it helps to make it clear that it is a custom header. In fact, RFC-6648 et al help bolster the case for use of an "X-" prefix, because -- as vendors of HTTP clients and servers abandon the prefix -- your app-specific, private-API, personal-data-passing-mechanism is becoming even better-insulated against name-space collisions with the small number of official reserved header names. That said, my personal preference and recommendation is to go a step further and do e.g. "X-ACME-ClientDataFoo" (if your widget company is "ACME").

IMHO the IETF spec is insufficiently specific to answer the OP's question, because it fails to distinguish between completely different use cases: (A) vendors introducing new globally-applicable features like "Forwarded-For" on the one hand, vs. (B) app developers passing app-specific strings to/from client and server. The spec only concerns itself with the former, (A). The question here is whether there are conventions for (B). There are. They involve grouping the parameters together alphabetically, and separating them from the many standards-relevant headers of type (A). Using the "X-" or "X-ACME-" prefix is convenient and legitimate for (B), and does not conflict with (A). The more vendors stop using "X-" for (A), the more cleanly-distinct the (B) ones will become.

Example:
Google (who carry a bit of weight in the various standards bodies) are -- as of today, 20141102 in this slight edit to my answer -- currently using "X-Mod-Pagespeed" to indicate the version of their Apache module involved in transforming a given response. Is anyone really suggesting that Google should use "Mod-Pagespeed", without the "X-", and/or ask the IETF to bless its use?

Summary:
If you're using custom HTTP Headers (as a sometimes-appropriate alternative to cookies) within your app to pass data to/from your server, and these headers are, explicitly, NOT intended ever to be used outside the context of your application, name-spacing them with an "X-" or "X-FOO-" prefix is a reasonable, and common, convention.

Filtering collections in C#

List<T> has a FindAll method that will do the filtering for you and return a subset of the list.

MSDN has a great code example here: http://msdn.microsoft.com/en-us/library/aa701359(VS.80).aspx

EDIT: I wrote this before I had a good understanding of LINQ and the Where() method. If I were to write this today i would probably use the method Jorge mentions above. The FindAll method still works if you're stuck in a .NET 2.0 environment though.

How to show one layout on top of the other programmatically in my case?

Use a FrameLayout with two children. The two children will be overlapped. This is recommended in one of the tutorials from Android actually, it's not a hack...

Here is an example where a TextView is displayed on top of an ImageView:

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent">

  <ImageView  
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 

    android:scaleType="center"
    android:src="@drawable/golden_gate" />

  <TextView
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_marginBottom="20dip"
    android:layout_gravity="center_horizontal|bottom"

    android:padding="12dip"

    android:background="#AA000000"
    android:textColor="#ffffffff"

    android:text="Golden Gate" />

</FrameLayout>

Here is the result

Can I pass parameters by reference in Java?

I don't think you can. Your best option might be to encapsulate the thing you want to pass "by ref" onto another class instance, and pass the (outer) class's reference (by value). If you see what I mean...

i.e. your method changes the internal state of the object it is passed, which is then visible to the caller.

how to check if string contains '+' character

You need this instead:

if(s.contains("+"))

contains() method of String class does not take regular expression as a parameter, it takes normal text.

EDIT:

String s = "ddjdjdj+kfkfkf";

if(s.contains("+"))
{
    String parts[] = s.split("\\+");
    System.out.print(parts[0]);
}

OUTPUT:

ddjdjdj

react-router getting this.props.location in child components

(Update) V5.1 & Hooks (Requires React >= 16.8)

You can use useHistory, useLocation and useRouteMatch in your component to get match, history and location .

const Child = () => {
  const location = useLocation();
  const history = useHistory();
  const match = useRouteMatch("write-the-url-you-want-to-match-here");

  return (
    <div>{location.pathname}</div>
  )
}

export default Child

(Update) V4 & V5

You can use withRouter HOC in order to inject match, history and location in your component props.

class Child extends React.Component {
  static propTypes = {
    match: PropTypes.object.isRequired,
    location: PropTypes.object.isRequired,
    history: PropTypes.object.isRequired
  }

  render() {
    const { match, location, history } = this.props

    return (
      <div>{location.pathname}</div>
    )
  }
}

export default withRouter(Child)

(Update) V3

You can use withRouter HOC in order to inject router, params, location, routes in your component props.

class Child extends React.Component {

  render() {
    const { router, params, location, routes } = this.props

    return (
      <div>{location.pathname}</div>
    )
  }
}

export default withRouter(Child)

Original answer

If you don't want to use the props, you can use the context as described in React Router documentation

First, you have to set up your childContextTypes and getChildContext

class App extends React.Component{

  getChildContext() {
    return {
      location: this.props.location
    }
  }

  render() {
    return <Child/>;
  }
}

App.childContextTypes = {
    location: React.PropTypes.object
}

Then, you will be able to access to the location object in your child components using the context like this

class Child extends React.Component{

   render() {
     return (
       <div>{this.context.location.pathname}</div>
     )
   }

}

Child.contextTypes = {
    location: React.PropTypes.object
 }

How to subtract days from a plain Date?

A few of the existing solutions were close, but not quite exactly what I wanted. This function works with both positive or negative values and handles boundary cases.

function addDays(date, days) {
    return new Date(
        date.getFullYear(),
        date.getMonth(),
        date.getDate() + days,
        date.getHours(),
        date.getMinutes(),
        date.getSeconds(),
        date.getMilliseconds()
    );
}

How do you find all subclasses of a given class in Java?

It should be noted as well that this will of course only find all those subclasses that exist on your current classpath. Presumably this is OK for what you are currently looking at, and chances are you did consider this, but if you have at any point released a non-final class into the wild (for varying levels of "wild") then it is entirely feasible that someone else has written their own subclass that you will not know about.

Thus if you happened to be wanting to see all subclasses because you want to make a change and are going to see how it affects subclasses' behaviour - then bear in mind the subclasses that you can't see. Ideally all of your non-private methods, and the class itself should be well-documented; make changes according to this documentation without changing the semantics of methods/non-private fields and your changes should be backwards-compatible, for any subclass that followed your definition of the superclass at least.

What are the "spec.ts" files generated by Angular CLI for?

The spec files are unit tests for your source files. The convention for Angular applications is to have a .spec.ts file for each .ts file. They are run using the Jasmine javascript test framework through the Karma test runner (https://karma-runner.github.io/) when you use the ng test command.

You can use this for some further reading:

https://angular.io/guide/testing

Best practice to call ConfigureAwait for all server-side code

The biggest draw back I've found with using ConfigureAwait(false) is that the thread culture is reverted to the system default. If you've configured a culture e.g ...

<system.web>
    <globalization culture="en-AU" uiCulture="en-AU" />    
    ...

and you're hosting on a server whose culture is set to en-US, then you will find before ConfigureAwait(false) is called CultureInfo.CurrentCulture will return en-AU and after you will get en-US. i.e.

// CultureInfo.CurrentCulture ~ {en-AU}
await xxxx.ConfigureAwait(false);
// CultureInfo.CurrentCulture ~ {en-US}

If your application is doing anything which requires culture specific formatting of data, then you'll need to be mindful of this when using ConfigureAwait(false).

Format the date using Ruby on Rails

Once you have parsed the timestamp string and have a time object (see other answers for details), you can use Time.to_formatted_s from Rails. It has several formats built in that you can specify with symbols.

Quote:

time = Time.now                     # => Thu Jan 18 06:10:17 CST 2007

time.to_formatted_s(:time)          # => "06:10"
time.to_s(:time)                    # => "06:10"

time.to_formatted_s(:db)            # => "2007-01-18 06:10:17"
time.to_formatted_s(:number)        # => "20070118061017"
time.to_formatted_s(:short)         # => "18 Jan 06:10"
time.to_formatted_s(:long)          # => "January 18, 2007 06:10"
time.to_formatted_s(:long_ordinal)  # => "January 18th, 2007 06:10"
time.to_formatted_s(:rfc822)        # => "Thu, 18 Jan 2007 06:10:17 -0600"

(Time.to_s is an alias)

You can also define your own formats - usually in an initializer (Thanks to Dave Newton for pointing this out). This is how it's done:

# config/initializers/time_formats.rb
Time::DATE_FORMATS[:month_and_year] = "%B %Y"
Time::DATE_FORMATS[:short_ordinal] = lambda { |time| time.strftime("%B #{time.day.ordinalize}") }

What is the cleanest way to disable CSS transition effects temporarily?

Short Answer

Use this CSS:

.notransition {
  -webkit-transition: none !important;
  -moz-transition: none !important;
  -o-transition: none !important;
  transition: none !important;
}

Plus either this JS (without jQuery)...

someElement.classList.add('notransition'); // Disable transitions
doWhateverCssChangesYouWant(someElement);
someElement.offsetHeight; // Trigger a reflow, flushing the CSS changes
someElement.classList.remove('notransition'); // Re-enable transitions

Or this JS with jQuery...

$someElement.addClass('notransition'); // Disable transitions
doWhateverCssChangesYouWant($someElement);
$someElement[0].offsetHeight; // Trigger a reflow, flushing the CSS changes
$someElement.removeClass('notransition'); // Re-enable transitions

... or equivalent code using whatever other library or framework you're working with.

Explanation

This is actually a fairly subtle problem.

First up, you probably want to create a 'notransition' class that you can apply to elements to set their *-transition CSS attributes to none. For instance:

.notransition {
  -webkit-transition: none !important;
  -moz-transition: none !important;
  -o-transition: none !important;
  transition: none !important;
}

_{(Minor aside - note the lack of an -ms-transition in there. You don't need it. The first version of Internet Explorer to support transitions at all was IE 10, which supported them unprefixed.)}

But that's just style, and is the easy bit. When you come to try and use this class, you'll run into a trap. The trap is that code like this won't work the way you might naively expect:

// Don't do things this way! It doesn't work!
someElement.classList.add('notransition')
someElement.style.height = '50px' // just an example; could be any CSS change
someElement.classList.remove('notransition')

Naively, you might think that the change in height won't be animated, because it happens while the 'notransition' class is applied. In reality, though, it will be animated, at least in all modern browsers I've tried. The problem is that the browser is caching the styling changes that it needs to make until the JavaScript has finished executing, and then making all the changes in a single reflow. As a result, it does a reflow where there is no net change to whether or not transitions are enabled, but there is a net change to the height. Consequently, it animates the height change.

You might think a reasonable and clean way to get around this would be to wrap the removal of the 'notransition' class in a 1ms timeout, like this:

// Don't do things this way! It STILL doesn't work!
someElement.classList.add('notransition')
someElement.style.height = '50px' // just an example; could be any CSS change
setTimeout(function () {someElement.classList.remove('notransition')}, 1);

but this doesn't reliably work either. I wasn't able to make the above code break in WebKit browsers, but on Firefox (on both slow and fast machines) you'll sometimes (seemingly at random) get the same behaviour as using the naive approach. I guess the reason for this is that it's possible for the JavaScript execution to be slow enough that the timeout function is waiting to execute by the time the browser is idle and would otherwise be thinking about doing an opportunistic reflow, and if that scenario happens, Firefox executes the queued function before the reflow.

The only solution I've found to the problem is to force a reflow of the element, flushing the CSS changes made to it, before removing the 'notransition' class. There are various ways to do this - see here for some. The closest thing there is to a 'standard' way of doing this is to read the offsetHeight property of the element.

One solution that actually works, then, is

someElement.classList.add('notransition'); // Disable transitions
doWhateverCssChangesYouWant(someElement);
someElement.offsetHeight; // Trigger a reflow, flushing the CSS changes
someElement.classList.remove('notransition'); // Re-enable transitions

Here's a JS fiddle that illustrates the three possible approaches I've described here (both the one successful approach and the two unsuccessful ones): http://jsfiddle.net/2uVAA/131/

Calculate the display width of a string in Java

Use the getWidth method in the following class:

import java.awt.*;
import java.awt.geom.*;
import java.awt.font.*;

class StringMetrics {

  Font font;
  FontRenderContext context;

  public StringMetrics(Graphics2D g2) {

    font = g2.getFont();
    context = g2.getFontRenderContext();
  }

  Rectangle2D getBounds(String message) {

    return font.getStringBounds(message, context);
  }

  double getWidth(String message) {

    Rectangle2D bounds = getBounds(message);
    return bounds.getWidth();
  }

  double getHeight(String message) {

    Rectangle2D bounds = getBounds(message);
    return bounds.getHeight();
  }

}

error Failed to build iOS project. We ran "xcodebuild" command but it exited with error code 65

cd ios && rm Podfile.lock && pod install worked for me.

"Expected an indented block" error?

I also experienced that for example:

This code doesnt work and get the intended block error.

class Foo(models.Model):
title = models.CharField(max_length=200)
body = models.TextField()
pub_date = models.DateTimeField('date published')
likes = models.IntegerField()

def __unicode__(self):
return self.title

However, when i press tab before typing return self.title statement, the code works.

class Foo(models.Model):
title = models.CharField(max_length=200)
body = models.TextField()
pub_date = models.DateTimeField('date published')
likes = models.IntegerField()

def __unicode__(self):
    return self.title

Hope, this will help others.

java.math.BigInteger cannot be cast to java.lang.Long

I'm lacking context, but this is working just fine:

List<BigInteger> nums = new ArrayList<BigInteger>();
Long max = Collections.max(nums).longValue(); // from BigInteger to Long...

How to concatenate int values in java?

I would suggest converting them to Strings.

StringBuilder concatenated = new StringBuilder();
concatenated.append(a);
concatenated.append(b);
/// etc...
concatenated.append(e);

Then converting back to an Integer:

Integer.valueOf(concatenated.toString());

ImageView in android XML layout with layout_height="wrap_content" has padding top & bottom

I had a simular issue and resolved it using android:adjustViewBounds="true" on the ImageView.

<ImageView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:adjustViewBounds="true"
    android:contentDescription="@string/banner_alt"
    android:src="@drawable/banner_portrait" />

How to run ssh-add on windows?

If you are trying to setup a key for using git with ssh, there's always an option to add a configuration for the identity file.

vi ~/.ssh/config

Host example.com
IdentityFile ~/.ssh/example_key

How to generate and validate a software license key?

I strongly believe, that only public key cryptography based licensing system is the right approach here, because you don't have to include essential information required for license generation into your sourcecode.

In the past, I've used Treek's Licensing Library many times, because it fullfills this requirements and offers really good price. It uses the same license protection for end users and itself and noone cracked that until now. You can also find good tips on the website to avoid piracy and cracking.

How to get the category title in a post in Wordpress?

You can use

<?php the_category(', '); ?>

which would output them in a comma separated list.

You can also do the same for tags as well:

<?php the_tags('<em>:</em>', ', ', ''); ?>

How to install xgboost in Anaconda Python (Windows platform)?

The package directory states that xgboost is unstable for windows and is disabled:

pip installation on windows is currently disabled for further invesigation, please install from github.

https://pypi.python.org/pypi/xgboost/

Javascript counting number of objects in object

In recent browsers you can use:

Object.keys(obj.Data).length

See MDN

For older browsers, use the for-in loop in Michael Geary's answer.

Convert string to Python class object?

This could work:

import sys

def str_to_class(classname):
    return getattr(sys.modules[__name__], classname)

No String-argument constructor/factory method to deserialize from String value ('')

This exception says that you are trying to deserialize the object "Address" from string "\"\"" instead of an object description like "{…}". The deserializer can't find a constructor of Address with String argument. You have to replace "" by {} to avoid this error.

Setting onSubmit in React.js

I'd also suggest moving the event handler outside render.

var OnSubmitTest = React.createClass({

  submit: function(e){
    e.preventDefault();
    alert('it works!');
  }

  render: function() {
    return (
      <form onSubmit={this.submit}>
        <button>Click me</button>
      </form>
    );
  }
});

How can compare-and-swap be used for a wait-free mutual exclusion for any shared data structure?

The linked list holds operations on the shared data structure.

For example, if I have a stack, it will be manipulated with pushes and pops. The linked list would be a set of pushes and pops on the pseudo-shared stack. Each thread sharing that stack will actually have a local copy, and to get to the current shared state, it'll walk the linked list of operations, and apply each operation in order to its local copy of the stack. When it reaches the end of the linked list, its local copy holds the current state (though, of course, it's subject to becoming stale at any time).

In the traditional model, you'd have some sort of locks around each push and pop. Each thread would wait to obtain a lock, then do a push or pop, then release the lock.

In this model, each thread has a local snapshot of the stack, which it keeps synchronized with other threads' view of the stack by applying the operations in the linked list. When it wants to manipulate the stack, it doesn't try to manipulate it directly at all. Instead, it simply adds its push or pop operation to the linked list, so all the other threads can/will see that operation and they can all stay in sync. Then, of course, it applies the operations in the linked list, and when (for example) there's a pop it checks which thread asked for the pop. It uses the popped item if and only if it's the thread that requested this particular pop.

phonegap open link in browser

As answered in other posts, you have two different options for different platforms. What I do is:

document.addEventListener('deviceready', onDeviceReady, false);

function onDeviceReady() {

    // Mock device.platform property if not available
    if (!window.device) {
        window.device = { platform: 'Browser' };
    }

    handleExternalURLs();
}

function handleExternalURLs() {
    // Handle click events for all external URLs
    if (device.platform.toUpperCase() === 'ANDROID') {
        $(document).on('click', 'a[href^="http"]', function (e) {
            var url = $(this).attr('href');
            navigator.app.loadUrl(url, { openExternal: true });
            e.preventDefault();
        });
    }
    else if (device.platform.toUpperCase() === 'IOS') {
        $(document).on('click', 'a[href^="http"]', function (e) {
            var url = $(this).attr('href');
            window.open(url, '_system');
            e.preventDefault();
        });
    }
    else {
        // Leave standard behaviour
    }
}

So as you can see I am checking the device platform and depending on that I am using a different method. In case of a standard browser, I leave standard behaviour. From now on the solution will work fine on Android, iOS and in a browser, while HTML page won't be changed, so that it can have URLs represented as standard anchor

<a href="http://stackoverflow.com">

The solution requires InAppBrowser and Device plugins

415 Unsupported Media Type - POST json to OData service in lightswitch 2012

It looks like this issue has to do with the difference between the Content-Type and Accept headers. In HTTP, Content-Type is used in request and response payloads to convey the media type of the current payload. Accept is used in request payloads to say what media types the server may use in the response payload.

So, having a Content-Type in a request without a body (like your GET request) has no meaning. When you do a POST request, you are sending a message body, so the Content-Type does matter.

If a server is not able to process the Content-Type of the request, it will return a 415 HTTP error. (If a server is not able to satisfy any of the media types in the request Accept header, it will return a 406 error.)

In OData v3, the media type "application/json" is interpreted to mean the new JSON format ("JSON light"). If the server does not support reading JSON light, it will throw a 415 error when it sees that the incoming request is JSON light. In your payload, your request body is verbose JSON, not JSON light, so the server should be able to process your request. It just doesn't because it sees the JSON light content type.

You could fix this in one of two ways:

Make the Content-Type "application/json;odata=verbose" in your POST request, or
Include the DataServiceVersion header in the request and set it be less than v3. For example:
```
DataServiceVersion: 2.0;
```

(Option 2 assumes that you aren't using any v3 features in your request payload.)

Why doesn't wireshark detect my interface?

In Windows, with Wireshark 2.0.4, running as Administrator did not solve this for me. What did was restarting the NetGroup Packet Filter Driver (npf) service:

Open a Command Prompt with administrative privileges.
Execute the command sc query npf and verify if the service is running.
Execute the command sc stop npf followed by the command sc start npf.
Open WireShark and press F5.

Source: http://dynamic-datacenter.be/?p=1279

UML diagram shapes missing on Visio 2013

Please check this KB article : http://support.microsoft.com/kb/2259709 This issue occurs because Visio 2013 uses new UML and database modeling templates that are not used by Visio 2010 or by earlier versions of Visio. And it applies to both :

"Microsoft Visio Professional 2013" and "Microsoft Visio Standard 2013"

So upgrading to Pro might not help as well.

Change <br> height using CSS

The line height of the br tag can be different from the line height of the rest of the text inside a paragraph text by setting font-size for br tag.

Example: br { font-size: 200%; }

How do I select child elements of any depth using XPath?

Also, you can do it with css selectors:

form#myform input[type='submit']

space beween elements in css elector means searching input[type='submit'] that elements at any depth of parent form#myform element

T-sql - determine if value is integer

With sqlserver 2005 and later you can use regex-like character classes with LIKE operator. See here.

To check if a string is a non-negative integer (it is a sequence of decimal digits) you can test that it doesn't contain other characters.

SELECT numstr
  FROM table
 WHERE numstr NOT LIKE '%[^0-9]%'

Note1: This will return empty strings too.

Note2: Using LIKE '%[0-9]%' will return any string that contains at least a digit.

See fiddle

Transmitting newline character "\n"

late to the party, but if anyone comes across this, javascript has a encodeURI method

Trouble using ROW_NUMBER() OVER (PARTITION BY ...)

I would do something like this:

;WITH x 
 AS (SELECT *, 
            Row_number() 
              OVER( 
                partition BY employeeid 
                ORDER BY datestart) rn 
     FROM   employeehistory) 
SELECT * 
FROM   x x1 
   LEFT OUTER JOIN x x2 
                ON x1.rn = x2.rn + 1

Or maybe it would be x2.rn - 1. You'll have to see. In any case, you get the idea. Once you have the table joined on itself, you can filter, group, sort, etc. to get what you need.

Reliable way for a Bash script to get the full path to itself

Here's what I've come up with (edit: plus some tweaks provided by sfstewman, levigroker, Kyle Strand, and Rob Kennedy), that seems to mostly fit my "better" criteria:

SCRIPTPATH="$( cd "$(dirname "$0")" >/dev/null 2>&1 ; pwd -P )"

That SCRIPTPATH line seems particularly roundabout, but we need it rather than SCRIPTPATH=`pwd` in order to properly handle spaces and symlinks.

The inclusion of output redirection (>/dev/null 2>&1) handles the rare(?) case where cd might produce output that would interfere with the surrounding $( ... ) capture. (Such as cd being overridden to also ls a directory after switching to it.)

Note also that esoteric situations, such as executing a script that isn't coming from a file in an accessible file system at all (which is perfectly possible), is not catered to there (or in any of the other answers I've seen).

Meaning of Choreographer messages in Logcat

This usually happens when debugging using the emulator, which is known to be slow anyway.

Coloring Buttons in Android with Material Design and AppCompat

Edit (22.06.2016):

Appcompat library started to support material buttons after I posted the original response. In this post you can see the easiest implementation of raised and flat buttons.

Original Answer:

Since that AppCompat doesn't support the button yet you can use xml as backgrounds. For doing that I had a look at the source code of the Android and found the related files for styling material buttons.

1 - Look at the original implementation of material button from source.

Have a look at the btn_default_material.xml on android source code.

You can copy the file into your projects drawable-v21 folder. But don't touch the color attr here. The file you need to change is the second file.

drawable-v21/custom_btn.xml

<ripple xmlns:android="http://schemas.android.com/apk/res/android"
    android:color="?attr/colorControlHighlight">
    <item android:drawable="@drawable/btn_default_mtrl_shape" />
</ripple>

2 - Get the shape of the original material button

As you realise there is a shape used inside this drawable which you can find in this file of the source code.

<inset xmlns:android="http://schemas.android.com/apk/res/android"
   android:insetLeft="@dimen/button_inset_horizontal_material"
   android:insetTop="@dimen/button_inset_vertical_material"
   android:insetRight="@dimen/button_inset_horizontal_material"
   android:insetBottom="@dimen/button_inset_vertical_material">
<shape android:shape="rectangle">
    <corners android:radius="@dimen/control_corner_material" />
    <solid android:color="?attr/colorButtonNormal" />
    <padding android:left="@dimen/button_padding_horizontal_material"
             android:top="@dimen/button_padding_vertical_material"
             android:right="@dimen/button_padding_horizontal_material"
             android:bottom="@dimen/button_padding_vertical_material" />
</shape>

3 - Getting dimensions of the material button

And in this file you there are some dimensions used from the file that you can find here. You can copy the whole file and put into your values folder. This is important for applying the same size (that is used in material buttons) to all buttons

4 - Create another drawable file for old versions

For older versions you should have another drawable with the same name. I am directly putting the items inline instead of referencing. You may want to reference them. But again, the most important thing is the original dimensions of the material button.

drawable/custom_btn.xml

    <?xml version="1.0" encoding="utf-8"?>
    <selector xmlns:android="http://schemas.android.com/apk/res/android">
    
    <!-- pressed state -->
    <item android:state_pressed="true">
        <inset xmlns:android="http://schemas.android.com/apk/res/android"
            android:insetLeft="@dimen/button_inset_horizontal_material"
            android:insetTop="@dimen/button_inset_vertical_material"
            android:insetRight="@dimen/button_inset_horizontal_material"
            android:insetBottom="@dimen/button_inset_vertical_material">
            <shape android:shape="rectangle">
                <corners android:radius="@dimen/control_corner_material" />
                <solid android:color="@color/PRESSED_STATE_COLOR" />
                <padding android:left="@dimen/button_padding_horizontal_material"
                    android:top="@dimen/button_padding_vertical_material"
                    android:right="@dimen/button_padding_horizontal_material"
                    android:bottom="@dimen/button_padding_vertical_material" />
            </shape>
        </inset>
    </item>
    
    <!-- focused state -->
    <item android:state_focused="true">
        <inset xmlns:android="http://schemas.android.com/apk/res/android"
            android:insetLeft="@dimen/button_inset_horizontal_material"
            android:insetTop="@dimen/button_inset_vertical_material"
            android:insetRight="@dimen/button_inset_horizontal_material"
            android:insetBottom="@dimen/button_inset_vertical_material">
            <shape android:shape="rectangle">
                <corners android:radius="@dimen/control_corner_material" />
                <solid android:color="@color/FOCUSED_STATE_COLOR" />
                <padding android:left="@dimen/button_padding_horizontal_material"
                    android:top="@dimen/button_padding_vertical_material"
                    android:right="@dimen/button_padding_horizontal_material"
                    android:bottom="@dimen/button_padding_vertical_material" />
            </shape>
        </inset>
    </item>
    
    <!-- normal state -->
    <item>
        <inset xmlns:android="http://schemas.android.com/apk/res/android"
            android:insetLeft="@dimen/button_inset_horizontal_material"
            android:insetTop="@dimen/button_inset_vertical_material"
            android:insetRight="@dimen/button_inset_horizontal_material"
            android:insetBottom="@dimen/button_inset_vertical_material">
            <shape android:shape="rectangle">
                <corners android:radius="@dimen/control_corner_material" />
                <solid android:color="@color/NORMAL_STATE_COLOR" />
                <padding android:left="@dimen/button_padding_horizontal_material"
                    android:top="@dimen/button_padding_vertical_material"
                    android:right="@dimen/button_padding_horizontal_material"
                    android:bottom="@dimen/button_padding_vertical_material" />
            </shape>
        </inset>
    </item>
</selector>

Result

Your button will have ripple effect on Lollipop devices. The old versions will have exactly same button except the ripple effect. But since that you provide drawables for different states, they'll also respond to touch events (as the old way).

How to write data to a text file without overwriting the current data

Look into the File class.

You can create a streamwriter with

StreamWriter sw = File.Create(....)

You can open an existing file with

File.Open(...)

You can append text easily with

File.AppendAllText(...);

How get sound input from microphone in python, and process it on the fly?

If you are using LINUX, you can use pyALSAAUDIO. For windows, we have PyAudio and there is also a library called SoundAnalyse.

I found an example for Linux here:

#!/usr/bin/python
## This is an example of a simple sound capture script.
##
## The script opens an ALSA pcm for sound capture. Set
## various attributes of the capture, and reads in a loop,
## Then prints the volume.
##
## To test it out, run it and shout at your microphone:

import alsaaudio, time, audioop

# Open the device in nonblocking capture mode. The last argument could
# just as well have been zero for blocking mode. Then we could have
# left out the sleep call in the bottom of the loop
inp = alsaaudio.PCM(alsaaudio.PCM_CAPTURE,alsaaudio.PCM_NONBLOCK)

# Set attributes: Mono, 8000 Hz, 16 bit little endian samples
inp.setchannels(1)
inp.setrate(8000)
inp.setformat(alsaaudio.PCM_FORMAT_S16_LE)

# The period size controls the internal number of frames per period.
# The significance of this parameter is documented in the ALSA api.
# For our purposes, it is suficcient to know that reads from the device
# will return this many frames. Each frame being 2 bytes long.
# This means that the reads below will return either 320 bytes of data
# or 0 bytes of data. The latter is possible because we are in nonblocking
# mode.
inp.setperiodsize(160)

while True:
    # Read data from device
    l,data = inp.read()
    if l:
        # Return the maximum of the absolute value of all samples in a fragment.
        print audioop.max(data, 2)
    time.sleep(.001)

What does the percentage sign mean in Python

The modulus operator. The remainder when you divide two number.

For Example:

>>> 5 % 2 = 1 # remainder of 5 divided by 2 is 1
>>> 7 % 3 = 1 # remainer of 7 divided by 3 is 1
>>> 3 % 1 = 0 # because 1 divides evenly into 3

Setting value of active workbook in Excel VBA

This is all you need

Set wbOOR = ActiveWorkbook

Converting Long to Date in Java returns 1970

1220227200 corresponds to Jan 15 1980 (and indeed new Date(1220227200).toString() returns "Thu Jan 15 03:57:07 CET 1970"). If you pass a long value to a date, that is before 01/01/1970 it will in fact return a date of 01/01/1970. Make sure that your values are not in this situation (lower than 82800000).

Oracle date function for the previous month

Getting last nth months data retrieve

SELECT * FROM TABLE_NAME 
WHERE DATE_COLUMN BETWEEN '&STARTDATE' AND '&ENDDATE';

Convert string to number field

Within Crystal, you can do it by creating a formula that uses the ToNumber function. It might be a good idea to code for the possibility that the field might include non-numeric data - like so:

If NumericText ({field}) then ToNumber ({field}) else 0

Alternatively, you might find it easier to convert the field's datatype within the query used in the report.

What difference between the DATE, TIME, DATETIME, and TIMESTAMP Types

I have a slightly different perspective on the difference between a DATETIME and a TIMESTAMP. A DATETIME stores a literal value of a date and time with no reference to any particular timezone. So, I can set a DATETIME column to a value such as '2019-01-16 12:15:00' to indicate precisely when my last birthday occurred. Was this Eastern Standard Time? Pacific Standard Time? Who knows? Where the current session time zone of the server comes into play occurs when you set a DATETIME column to some value such as NOW(). The value stored will be the current date and time using the current session time zone in effect. But once a DATETIME column has been set, it will display the same regardless of what the current session time zone is.

A TIMESTAMP column on the other hand takes the '2019-01-16 12:15:00' value you are setting into it and interprets it in the current session time zone to compute an internal representation relative to 1/1/1970 00:00:00 UTC. When the column is displayed, it will be converted back for display based on whatever the current session time zone is. It's a useful fiction to think of a TIMESTAMP as taking the value you are setting and converting it from the current session time zone to UTC for storing and then converting it back to the current session time zone for displaying.

If my server is in San Francisco but I am running an event in New York that starts on 9/1/1029 at 20:00, I would use a TIMESTAMP column for holding the start time, set the session time zone to 'America/New York' and set the start time to '2009-09-01 20:00:00'. If I want to know whether the event has occurred or not, regardless of the current session time zone setting I can compare the start time with NOW(). Of course, for displaying in a meaningful way to a perspective customer, I would need to set the correct session time zone. If I did not need to do time comparisons, then I would probably be better off just using a DATETIME column, which will display correctly (with an implied EST time zone) regardless of what the current session time zone is.

TIMESTAMP LIMITATION

The TIMESTAMP type has a range of '1970-01-01 00:00:01' UTC to '2038-01-19 03:14:07' UTC and so it may not usable for your particular application. In that case you will have to use a DATETIME type. You will, of course, always have to be concerned that the current session time zone is set properly whenever you are using this type with date functions such as NOW().

Installing Apache Maven Plugin for Eclipse

I found Maven Integration for Eclipse here.

http://download.eclipse.org/technology/m2e/releases

After installing restart eclipse. Worked for me running Eclipse Juno.

Find TODO tags in Eclipse

Tasks view, under Window -> Show View -> Tasks

Created Button Click Event c#

    public MainWindow()
    {
        // This button needs to exist on your form.
        myButton.Click += myButton_Click;
    }

    void myButton_Click(object sender, RoutedEventArgs e)
    {
        MessageBox.Show("Message here");
        this.Close();
    }

What is "String args[]"? parameter in main method Java

Those are for command-line arguments in Java.

In other words, if you run

java MyProgram one two

Then args contains:

[ "one", "two" ]

public static void main(String [] args) {
    String one = args[0]; //=="one"
    String two = args[1]; //=="two"
}

The reason for this is to configure your application to run a particular way or provide it with some piece of information it needs.

If you are new to Java, I highly recommend reading through the official Oracle's Java™ Tutorials.

Setting up Vim for Python

Under Linux, What worked for me was John Anderson's (sontek) guide, which you can find at this link. However, I cheated and just used his easy configuration setup from his Git repostiory:

git clone -b vim https://github.com/sontek/dotfiles.git

cd dotfiles

./install.sh vim

His configuration is fairly up to date as of today.

"No X11 DISPLAY variable" - what does it mean?

you must enable X11 forwarding in you PuTTy

to do so open PuTTy, go to Connection => SSH => Tunnels and check mark the Enable X11 forwarding

Also sudo to server and export the below variable here IP is your local machine's IP

export DISPLAY=10.75.75.75:0.0

Rails Object to hash

You can get the attributes of a model object returned as a hash using either

@post.attributes

@post.as_json

as_json allows you to include associations and their attributes as well as specify which attributes to include/exclude (see documentation). However, if you only need the attributes of the base object, benchmarking in my app with ruby 2.2.3 and rails 4.2.2 demonstrates that attributes requires less than half as much time as as_json.

>> p = Problem.last
 Problem Load (0.5ms)  SELECT  "problems".* FROM "problems"  ORDER BY "problems"."id" DESC LIMIT 1
=> #<Problem id: 137, enabled: true, created_at: "2016-02-19 11:20:28", updated_at: "2016-02-26 07:47:34"> 
>>
>> p.attributes
=> {"id"=>137, "enabled"=>true, "created_at"=>Fri, 19 Feb 2016 11:20:28 UTC +00:00, "updated_at"=>Fri, 26 Feb 2016 07:47:34 UTC +00:00}
>>
>> p.as_json
=> {"id"=>137, "enabled"=>true, "created_at"=>Fri, 19 Feb 2016 11:20:28 UTC +00:00, "updated_at"=>Fri, 26 Feb 2016 07:47:34 UTC +00:00}
>>
>> n = 1000000
>> Benchmark.bmbm do |x|
?>   x.report("attributes") { n.times { p.attributes } }
?>   x.report("as_json")    { n.times { p.as_json } }
>> end
Rehearsal ----------------------------------------------
attributes   6.910000   0.020000   6.930000 (  7.078699)
as_json     14.810000   0.160000  14.970000 ( 15.253316)
------------------------------------ total: 21.900000sec

             user     system      total        real
attributes   6.820000   0.010000   6.830000 (  7.004783)
as_json     14.990000   0.050000  15.040000 ( 15.352894)

What is REST call and how to send a REST call?

REST is just a software architecture style for exposing resources.

Use HTTP methods explicitly.
Be stateless.
Expose directory structure-like URIs.
Transfer XML, JavaScript Object Notation (JSON), or both.

A typical REST call to return information about customer 34456 could look like:

http://example.com/customer/34456

Have a look at the IBM tutorial for REST web services

CSS: Change image src on img:hover

You cannot change the img src using css. You can use the following pure css solution though. HTML:

<div id="asks"></div>

CSS:

#asks {
  width: 100px;
  height: 100px;
  background-image: url('http://dummyimage.com/100x100/0000/fff');
}

#asks:hover {
  background-image: url('http://dummyimage.com/100x100/eb00eb/fff');
}

Or, if you don't want to use a div with a background image, you can use a javascript/jQuery solution. Html:

<img id="asks" src="http://dummyimage.com/100x100/000/fff" />

jQuery:

$('#asks')
  .mouseenter(function(){$('#asks').attr('src', 'http://dummyimage.com/100x100/eb00eb/fff');})
  .mouseleave(function(){$('#asks').attr('src', 'http://dummyimage.com/100x100/000/fff');});

How to add a custom right-click menu to a webpage?

A simple way you could do it is use onContextMenu to return a JavaScript function:

<input type="button" value="Example" onContextMenu="return RightClickFunction();">

<script>
 function RightClickFunction() {
  // Enter your code here;
  return false;
 }
</script>

And by entering return false; you will cancel out the context menu.

if you still want to display the context menu you can just remove the return false; line.

How to edit binary file on Unix systems

Bless is a high quality, full featured hex editor.

It is written in mono/Gtk# and its primary platform is GNU/Linux. However it should be able to run without problems on every platform that mono and Gtk# run. Main Features Bless currently provides the following features:

Efficient editing of large data files and block devices.
Multilevel undo - redo operations.
Customizable data views.
Fast data rendering on screen.
Multiple tabs.
Fast find and replace operations.
A data conversion table.
Advanced copy/paste capabilities.
Highlighting of selection pattern matches in the file.
Plugin based architecture.
Export of data to text and html (others with plugins).
Bitwise operations on data.
A comprehensive user manual.

copied from http://home.gna.org/bless/

Bootstrap 3: Offset isn't working?

If I get you right, you want something that seems to be the opposite of what is desired normally: you want a horizontal layout for small screens and vertically stacked elements on large screens. You may achieve this in a way like this:

<div class="container">
    <div class="row">
        <div class="hidden-md hidden-lg col-xs-3 col-xs-offset-6">a</div>
        <div class="hidden-md hidden-lg col-xs-3">b</div>
    </div>
    <div class="row">
        <div class="hidden-xs hidden-sm">c</div>

    </div>
</div>

On small screens, i.e. xs and sm, this generates one row with two columns with an offset of 6. On larger screens, i.e. md and lg, it generates two vertically stacked elements in full width (12 columns).

where is create-react-app webpack config and files?

I know it's pretty late, but for future people stumbling upon this issue, if you want to have access to the webpack config of CRA, there's no other way except you have to run:

$ npm run eject

However, with ejection, you'll strip away yourself from CRA pipeline of updates, therefore from the point of ejection, you have to maintain it yourself.

I have come across this issue many times, and therefore I've created a template for react apps which have most of the same config as CRA, but also additional perks (like styled-components, jest unit test, Travis ci for deployments, prettier, ESLint, etc...) to make the maintenance easier. Check out the repo.

How to sort pandas data frame using values from several columns?

DataFrame.sort is deprecated; use DataFrame.sort_values.

>>> df.sort_values(['c1','c2'], ascending=[False,True])
   c1   c2
0   3   10
3   2   15
1   2   30
4   2  100
2   1   20
>>> df.sort(['c1','c2'], ascending=[False,True])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/ampawake/anaconda/envs/pseudo/lib/python2.7/site-packages/pandas/core/generic.py", line 3614, in __getattr__
    return object.__getattribute__(self, name)
AttributeError: 'DataFrame' object has no attribute 'sort'

Change the color of a checked menu item in a navigation drawer

One need to set NavigateItem checked true whenever item in NavigateView is clicked

//listen for navigation events
NavigationView navigationView = (NavigationView)findViewById(R.id.navigation);
navigationView.setNavigationItemSelectedListener(this);
// select the correct nav menu item
navigationView.getMenu().findItem(mNavItemId).setChecked(true);

Add NavigationItemSelectedListener on NavigationView

  @Override
  public boolean onNavigationItemSelected(final MenuItem menuItem) {
    // update highlighted item in the navigation menu
    menuItem.setChecked(true);
    mNavItemId = menuItem.getItemId();

    // allow some time after closing the drawer before performing real navigation
    // so the user can see what is happening
    mDrawerLayout.closeDrawer(GravityCompat.START);
    mDrawerActionHandler.postDelayed(new Runnable() {
      @Override
      public void run() {
        navigate(menuItem.getItemId());
      }
    }, DRAWER_CLOSE_DELAY_MS);
    return true;
  }

How to close a web page on a button click, a hyperlink or a link button click?

double click the button and add write // this.close();

  private void buttonClick(object sender, EventArgs e)
{
    this.Close();
}

Typing the Enter/Return key using Python and Selenium

object.sendKeys("your message", Keys.ENTER);

It works.

how to change default python version?

In short: change the path in Environment Variables!

For Windows:

Advanced System Settings > Advance (tab). On bottom you'll find 'Environment Variables'
Double-click on the Path. You'll see path to one of the python installations, change that to path of your desired version.

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

If you are familiar with C++ and macros, then

#import "Class.h"

is similar to

{
#pragma once

#include "class.h"
}

which means that your Class will be loaded only once when your app runs.

MongoDB running but can't connect using shell

If your mongoDB server(remote server)'s version is greater then 4.0.3, then you will face this issue. Hence you should replace your current mongo-client shell with below mongo :

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 9DA31620334BD75D9DCB49F368818C72E52529D4
echo "deb [ arch=amd64,arm64 ] https://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/4.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-4.0.list
sudo apt-get update
sudo apt-get install -y mongodb-org

Then you mongo client will be able to connect your remove mongodb

How to find a value in an array and remove it by using PHP array functions?

<?php
$my_array = array('sheldon', 'leonard', 'howard', 'penny');
$to_remove = array('howard');
$result = array_diff($my_array, $to_remove);
?>

How to replace DOM element in place using Javascript?

I had a similar issue and found this thread. Replace didn't work for me, and going by the parent was difficult for my situation. Inner Html replaced the children, which wasn't what I wanted either. Using outerHTML got the job done. Hope this helps someone else!

currEl = <div>hello</div>
newElem = <span>Goodbye</span>
currEl.outerHTML = newElem
# currEl = <span>Goodbye</span>

How to display gpg key details without importing it?

When I stumbled up on this answer I was looking for a way to get an output that is easy to parse. For me the option --with-colons did the trick:

$ gpg --with-colons file
sec::4096:1:AAAAAAAAAAAAAAAA:YYYY-MM-DD::::Name (comment) email
ssb::4096:1:BBBBBBBBBBBBBBBB:YYYY-MM-DD::::

Documentation can be found here.

How can I go back/route-back on vue-router?

If you're using Vuex you can use https://github.com/vuejs/vuex-router-sync

Just initialize it in your main file with:

import VuexRouterSync from 'vuex-router-sync';
VuexRouterSync.sync(store, router);

Each route change will update route state object in Vuex. You can next create getter to use the from Object in route state or just use the state (better is to use getters, but it's other story https://vuex.vuejs.org/en/getters.html), so in short it would be (inside components methods/values):

this.$store.state.route.from.fullPath

You can also just place it in <router-link> component:

<router-link :to="{ path: $store.state.route.from.fullPath }"> 
  Back 
</router-link>

So when you use code above, link to previous path would be dynamically generated.

How to set multiple commands in one yaml file with Kubernetes?

command: ["/bin/sh","-c"]
args: ["command one; command two && command three"]

Explanation: The command ["/bin/sh", "-c"] says "run a shell, and execute the following instructions". The args are then passed as commands to the shell. In shell scripting a semicolon separates commands, and && conditionally runs the following command if the first succeed. In the above example, it always runs command one followed by command two, and only runs command three if command two succeeded.

Alternative: In many cases, some of the commands you want to run are probably setting up the final command to run. In this case, building your own Dockerfile is the way to go. Look at the RUN directive in particular.

init-param and context-param

Consider the below definition in web.xml

<servlet>
    <servlet-name>HelloWorld</servlet-name>
    <servlet-class>TestServlet</servlet-class>
    <init-param>
        <param-name>myprop</param-name>
        <param-value>value</param-value>
    </init-param>
</servlet>

You can see that init-param is defined inside a servlet element. This means it is only available to the servlet under declaration and not to other parts of the web application. If you want this parameter to be available to other parts of the application say a JSP this needs to be explicitly passed to the JSP. For instance passed as request.setAttribute(). This is highly inefficient and difficult to code.

So if you want to get access to global values from anywhere within the application without explicitly passing those values, you need to use Context Init parameters.

Consider the following definition in web.xml

 <web-app>
      <context-param>
           <param-name>myprop</param-name>
           <param-value>value</param-value>
      </context-param>
 </web-app>

This context param is available to all parts of the web application and it can be retrieved from the Context object. For instance, getServletContext().getInitParameter(“dbname”);

From a JSP you can access the context parameter using the application implicit object. For example, application.getAttribute(“dbname”);

How do I rename a repository on GitHub?

I rename my own just by simply :

going to github.com on my repository
Open Settings Tab
The first setting you can see is the "Repository Name"
Change the actual one and put the new name you want to give to your repository
Click on "Rename" button

After this step, GitHub will make sure that, your online repository matches your local folder name. At this step your problem is solved, unless you also want to rename your local folder. Then do it manually and just use the Github client for windows to refind again your repository into your hard drive, and Github will match it again. That's all! Very simple.

How to remove a branch locally?

By your tags, I'm assuming your using Github. Why not create some branch protection rules for your master branch? That way even if you do try to push to master, it will reject it.

1) Go to the 'Settings' tab of your repo on Github.

2) Click on 'Branches' on the left side-menu.

3) Click 'Add rule'

4) Enter 'master' for a branch pattern.

5) Check off 'Require pull request reviews before merging'

I would also recommend doing the same for your dev branch.

How to make a vertical line in HTML

I used a combination of the "hr" code suggested, and here's what my code looks like:

<hr style="width:0.5px; height:500px; position: absolute; left: 315px;"/>

I simply changed the value of the "left" pixel value to position it. (I used the vertical line to line-up content on my webpage, and then I removed it.)

Twitter - How to embed native video from someone else's tweet into a New Tweet or a DM

I eventually figured out an easy way to do it:

On your Twitter feed, click the date/time of the tweet containing the video. That will open the single tweet view
Look for the down-pointing arrow at the top-right corner of the tweet, click it to open drop-down menue
Select the "Embed Video" option and copy the HTML embed code and Paste it to Notepad
Find the last "t.co" shortened URL inside the HTML code (should be something like this: https://``t.co/tQM43ftXyM). Copy this URL and paste it in a new browser tab.
The browser will expand the shortened URL to something which looks like this: https://twitter.com/UserName/status/828267001496784896/video/1

This is the link to the Twitter Card containing the native video. Pasting this link in a new tweet or DM will include the native video in it!

How to take screenshot of a div with JavaScript?

After hours of research, I finally found a solution to take a screenshot of an element, even if the origin-clean FLAG is set (to prevent XSS), that´s why you can even capture for example Google Maps (in my case). I wrote a universal function to get a screenshot. The only thing you need in addition is the html2canvas library (https://html2canvas.hertzen.com/).

Example:

getScreenshotOfElement($("div#toBeCaptured").get(0), 0, 0, 100, 100, function(data) {
    // in the data variable there is the base64 image
    // exmaple for displaying the image in an <img>
    $("img#captured").attr("src", "data:image/png;base64,"+data);
});

Keep in mind console.log() and alert() won´t generate output if the size of the image is great.

Function:

function getScreenshotOfElement(element, posX, posY, width, height, callback) {
    html2canvas(element, {
        onrendered: function (canvas) {
            var context = canvas.getContext('2d');
            var imageData = context.getImageData(posX, posY, width, height).data;
            var outputCanvas = document.createElement('canvas');
            var outputContext = outputCanvas.getContext('2d');
            outputCanvas.width = width;
            outputCanvas.height = height;

            var idata = outputContext.createImageData(width, height);
            idata.data.set(imageData);
            outputContext.putImageData(idata, 0, 0);
            callback(outputCanvas.toDataURL().replace("data:image/png;base64,", ""));
        },
        width: width,
        height: height,
        useCORS: true,
        taintTest: false,
        allowTaint: false
    });
}

How can multiple rows be concatenated into one in Oracle without creating a stored procedure?

From Oracle 11gR2, the LISTAGG clause should do the trick:

SELECT question_id,
       LISTAGG(element_id, ',') WITHIN GROUP (ORDER BY element_id)
FROM YOUR_TABLE
GROUP BY question_id;

Beware if the resulting string is too big (more than 4000 chars for a VARCHAR2, for instance): from version 12cR2, we can use ON OVERFLOW TRUNCATE/ERROR to deal with this issue.

How do you properly return multiple values from a Promise?

Here is how I reckon you should be doing.

splitting the chain

Because both functions will be using amazingData, it makes sense to have them in a dedicated function. I usually do that everytime I want to reuse some data, so it is always present as a function arg.

As your example is running some code, I will suppose it is all declared inside a function. I will call it toto(). Then we will have another function which will run both afterSomething() and afterSomethingElse().

function toto() {
    return somethingAsync()
        .then( tata );
}

You will also notice I added a return statement as it is usually the way to go with Promises - you always return a promise so we can keep chaining if required. Here, somethingAsync() will produce amazingData and it will be available everywhere inside the new function.

Now what this new function will look like typically depends on is processAsync() also asynchronous?

processAsync not asynchronous

No reason to overcomplicate things if processAsync() is not asynchronous. Some old good sequential code would make it.

function tata( amazingData ) {
    var processed = afterSomething( amazingData );
    return afterSomethingElse( amazingData, processed );
}

function afterSomething( amazingData ) {
    return processAsync( amazingData );
}
function afterSomethingElse( amazingData, processedData ) {
}

Note that it does not matter if afterSomethingElse() is doing something async or not. If it does, a promise will be returned and the chain can continue. If it is not, then the result value will be returned. But because the function is called from a then(), the value will be wrapped into a promise anyway (at least in raw Javascript).

processAsync asynchronous

If processAsync() is asynchronous, the code will look slightly different. Here we consider afterSomething() and afterSomethingElse() are not going to be reused anywhere else.

function tata( amazingData ) {
    return afterSomething()
        .then( afterSomethingElse );

    function afterSomething( /* no args */ ) {
        return processAsync( amazingData );
    }
    function afterSomethingElse( processedData ) {
        /* amazingData can be accessed here */
    }
}

Same as before for afterSomethingElse(). It can be asynchronous or not. A promise will be returned, or a value wrapped into a resolved promise.

Your coding style is quite close to what I use to do, that is why I answered even after 2 years. I am not a big fan of having anonymous functions everywhere. I find it hard to read. Even if it is quite common in the community. It is as we replaced the callback-hell by a promise-purgatory.

I also like to keep the name of the functions in the then short. They will only be defined locally anyway. And most of the time they will call another function defined elsewhere - so reusable - to do the job. I even do that for functions with only 1 parameter, so I do not need to get the function in and out when I add/remove a parameter to the function signature.

Eating example

Here is an example:

function goingThroughTheEatingProcess(plenty, of, args, to, match, real, life) {
    return iAmAsync()
        .then(chew)
        .then(swallow);

        function chew(result) {
            return carefullyChewThis(plenty, of, args, "water", "piece of tooth", result);
        }

        function swallow(wine) {
            return nowIsTimeToSwallow(match, real, life, wine);
        }
}

function iAmAsync() {
    return Promise.resolve("mooooore");
}

function carefullyChewThis(plenty, of, args, and, some, more) {
    return true;
}

function nowIsTimeToSwallow(match, real, life, bobool) {
}

Do not focus too much on the Promise.resolve(). It is just a quick way to create a resolved promise. What I try to achieve by this is to have all the code I am running in a single location - just underneath the thens. All the others functions with a more descriptive name are reusable.

The drawback with this technique is that it is defining a lot of functions. But it is a necessary pain I am afraid in order to avoid having anonymous functions all over the place. And what is the risk anyway: a stack overflow? (joke!)

Using arrays or objects as defined in other answers would work too. This one in a way is the answer proposed by Kevin Reid.

You can also use bind() or Promise.all(). Note that they will still require you to split your code.

using bind

If you want to keep your functions reusable but do not really need to keep what is inside the then very short, you can use bind().

function tata( amazingData ) {
    return afterSomething( amazingData )
        .then( afterSomethingElse.bind(null, amazingData) );
}

function afterSomething( amazingData ) {
    return processAsync( amazingData );
}
function afterSomethingElse( amazingData, processedData ) {
}

To keep it simple, bind() will prepend the list of args (except the first one) to the function when it is called.

using Promise.all

In your post you mentionned the use of spread(). I never used the framework you are using, but here is how you should be able to use it.

Some believe Promise.all() is the solution to all problems, so it deserves to be mentioned I guess.

function tata( amazingData ) {
    return Promise.all( [ amazingData, afterSomething( amazingData ) ] )
        .then( afterSomethingElse );
}

function afterSomething( amazingData ) {
    return processAsync( amazingData );
}
function afterSomethingElse( args ) {
    var amazingData = args[0];
    var processedData = args[1];
}

You can pass data to Promise.all() - note the presence of the array - as long as promises, but make sure none of the promises fail otherwise it will stop processing.

And instead of defining new variables from the args argument, you should be able to use spread() instead of then() for all sort of awesome work.

How do I add FTP support to Eclipse?

SFTP Plug-in: http://www.jcraft.com/eclipse-sftp/ :)

How do I link a JavaScript file to a HTML file?

To include an external Javascript file you use the <script> tag. The src attribute points to the location of your Javascript file within your web project.

<script src="some.js" type="text/javascript"></script>

JQuery is simply a Javascript file, so if you download a copy of the file you can include it within your page using a script tag. You can also include Jquery from a content distribution network such as the one hosted by Google.

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>

Is it better practice to use String.format over string Concatenation in Java?

Which one is more readable depends on how your head works.

You got your answer right there.

It's a matter of personal taste.

String concatenation is marginally faster, I suppose, but that should be negligible.

How do you find the current user in a Windows environment?

Via powershell (file.ps1) I use the following

$username = [System.Security.Principal.WindowsIdentity]::GetCurrent().Name

It returns the name of the user in the "Domain\Username" format. If you just want the username just write

$username = [System.Security.Principal.WindowsIdentity]::GetCurrent().Name.Split("\")[1]

The advantage is that It works with windows 10 windows 8 server 2016. As far as I remember with also other OS like Win7 etc. (not older) . And yeah via batch you can simply use

 $username = &whoami

Count the number of commits on a Git branch

You can use this command which uses awk on git bash/unix to get the number of commits.

    git shortlog -s -n | awk '/Author/ { print $1 }'

How can I get Git to follow symlinks?

What I did to add to get the files within a symlink into Git (I didn't use a symlink but):

sudo mount --bind SOURCEDIRECTORY TARGETDIRECTORY

Do this command in the Git-managed directory. TARGETDIRECTORY has to be created before the SOURCEDIRECTORY is mounted into it.

It works fine on Linux, but not on OS X! That trick helped me with Subversion too. I use it to include files from an Dropbox account, where a webdesigner does his/her stuff.

How do you check whether a number is divisible by another number (Python)?

The simplest way is to test whether a number is an integer is int(x) == x. Otherwise, what David Heffernan said.

How to get an absolute file path in Python

Install a third-party path module (found on PyPI), it wraps all the os.path functions and other related functions into methods on an object that can be used wherever strings are used:

>>> from path import path
>>> path('mydir/myfile.txt').abspath()
'C:\\example\\cwd\\mydir\\myfile.txt'

Checking Maven Version

You need to add path to svn.exe file to system environment, variable PATH, after that you can run command mvn from any folder. You can do it from command line(cmd.exe) like this, for example:

set PATH=%PATH%;C:\maven\bin

Or you can got to the folder where mvn.exe is, and run your command there.

And you need not mvn -version, but mvn --version parameter.

Strange out of memory issue while loading an image to a Bitmap object

I had this same issue and solved it by avoiding the BitmapFactory.decodeStream or decodeFile functions and instead used BitmapFactory.decodeFileDescriptor

decodeFileDescriptor looks like it calls different native methods than the decodeStream/decodeFile.

Anyways, what worked was this (note that I added some options as some had above, but that's not what made the difference. What is critical is the call to BitmapFactory.decodeFileDescriptor instead of decodeStream or decodeFile):

private void showImage(String path)   {

    Log.i("showImage","loading:"+path);
    BitmapFactory.Options bfOptions=new BitmapFactory.Options();
    bfOptions.inDither=false;                     //Disable Dithering mode
    bfOptions.inPurgeable=true;                   //Tell to gc that whether it needs free memory, the Bitmap can be cleared
    bfOptions.inInputShareable=true;              //Which kind of reference will be used to recover the Bitmap data after being clear, when it will be used in the future
    bfOptions.inTempStorage=new byte[32 * 1024]; 

    File file=new File(path);
    FileInputStream fs=null;
    try {
        fs = new FileInputStream(file);
    } catch (FileNotFoundException e) {
        //TODO do something intelligent
        e.printStackTrace();
    }

    try {
        if(fs!=null) bm=BitmapFactory.decodeFileDescriptor(fs.getFD(), null, bfOptions);
    } catch (IOException e) {
        //TODO do something intelligent
        e.printStackTrace();
    } finally{ 
        if(fs!=null) {
            try {
                fs.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
    //bm=BitmapFactory.decodeFile(path, bfOptions); This one causes error: java.lang.OutOfMemoryError: bitmap size exceeds VM budget

    im.setImageBitmap(bm);
    //bm.recycle();
    bm=null;                        
}

I think there is a problem with the native function used in decodeStream/decodeFile. I have confirmed that a different native method is called when using decodeFileDescriptor. Also what I've read is "that Images (Bitmaps) are not allocated in a standard Java way but via native calls; the allocations are done outside of the virtual heap, but are counted against it!"

send Content-Type: application/json post with node.js

Simple Example

var request = require('request');

//Custom Header pass
var headersOpt = {  
    "content-type": "application/json",
};
request(
        {
        method:'post',
        url:'https://www.googleapis.com/urlshortener/v1/url', 
        form: {name:'hello',age:25}, 
        headers: headersOpt,
        json: true,
    }, function (error, response, body) {  
        //Print the Response
        console.log(body);  
});

How to select a single column with Entity Framework?

If you're fetching a single item only then, you need use select before your FirstOrDefault()/SingleOrDefault(). And you can use anonymous object of the required properties.

var name = dbContext.MyTable.Select(x => new { x.UserId, x.Name }).FirstOrDefault(x => x.UserId == 1)?.Name;

Above query will be converted to this:

Select Top (1) UserId, Name from MyTable where UserId = 1;

For multiple items you can simply chain Select after Where:

var names = dbContext.MyTable.Where(x => x.UserId > 10).Select(x => x.Name);

Use anonymous object inside Select if you need more than one properties.

How to bring a window to the front?

I had the same problem with bringing a JFrame to the front under Ubuntu (Java 1.6.0_10). And the only way I could resolve it is by providing a WindowListener. Specifically, I had to set my JFrame to always stay on top whenever toFront() is invoked, and provide windowDeactivated event handler to setAlwaysOnTop(false).

So, here is the code that could be placed into a base JFrame, which is used to derive all application frames.

@Override
public void setVisible(final boolean visible) {
  // make sure that frame is marked as not disposed if it is asked to be visible
  if (visible) {
      setDisposed(false);
  }
  // let's handle visibility...
  if (!visible || !isVisible()) { // have to check this condition simply because super.setVisible(true) invokes toFront if frame was already visible
      super.setVisible(visible);
  }
  // ...and bring frame to the front.. in a strange and weird way
  if (visible) {
      toFront();
  }
}

@Override
public void toFront() {
  super.setVisible(true);
  int state = super.getExtendedState();
  state &= ~JFrame.ICONIFIED;
  super.setExtendedState(state);
  super.setAlwaysOnTop(true);
  super.toFront();
  super.requestFocus();
  super.setAlwaysOnTop(false);
}

Whenever your frame should be displayed or brought to front call frame.setVisible(true).

Since I moved to Ubuntu 9.04 there seems to be no need in having a WindowListener for invoking super.setAlwaysOnTop(false) -- as can be observed; this code was moved to the methods toFront() and setVisible().

Please note that method setVisible() should always be invoked on EDT.

Use a loop to plot n charts Python

Ok, so the easiest method to create several plots is this:

import matplotlib.pyplot as plt
x=[[1,2,3,4],[1,2,3,4],[1,2,3,4],[1,2,3,4]]
y=[[1,2,3,4],[1,2,3,4],[1,2,3,4],[1,2,3,4]]
for i in range(len(x)):
    plt.figure()
    plt.plot(x[i],y[i])
    # Show/save figure as desired.
    plt.show()
# Can show all four figures at once by calling plt.show() here, outside the loop.
#plt.show()

Note that you need to create a figure every time or pyplot will plot in the first one created.

If you want to create several data series all you need to do is:

import matplotlib.pyplot as plt
plt.figure()
x=[[1,2,3,4],[1,2,3,4],[1,2,3,4],[1,2,3,4]]
y=[[1,2,3,4],[2,3,4,5],[3,4,5,6],[7,8,9,10]]
plt.plot(x[0],y[0],'r',x[1],y[1],'g',x[2],y[2],'b',x[3],y[3],'k')

You could automate it by having a list of colours like ['r','g','b','k'] and then just calling both entries in this list and corresponding data to be plotted in a loop if you wanted to. If you just want to programmatically add data series to one plot something like this will do it (no new figure is created each time so everything is plotted in the same figure):

import matplotlib.pyplot as plt
x=[[1,2,3,4],[1,2,3,4],[1,2,3,4],[1,2,3,4]]
y=[[1,2,3,4],[2,3,4,5],[3,4,5,6],[7,8,9,10]]
colours=['r','g','b','k']
plt.figure() # In this example, all the plots will be in one figure.    
for i in range(len(x)):
    plt.plot(x[i],y[i],colours[i])
plt.show()

Hope this helps. If anything matplotlib has a very good documentation page with plenty of examples.

17 Dec 2019: added plt.show() and plt.figure() calls to clarify this part of the story.

What are .tpl files? PHP, web design

.tpl shows there is a smarty! Smarty is a template language to split out PHP code from HTML code. Which gives us to the ability to do design stuff on a page which has not included PHP code.

'JSON' is undefined error in JavaScript in Internet Explorer

Maybe it is not what you are looking for, but I had a similar problem and i solved it including JSON 2 to my application:

https://github.com/douglascrockford/JSON-js

Other browsers natively implements JSON but IE < 8 (also IE 8 compatibility mode) does not, that's why you need to include it.

Here is a related question: JSON on IE6 (IE7)

UPDATE

the JSON parser has been updated so you should use the new one: http://bestiejs.github.io/json3/

How do I add a Maven dependency in Eclipse?

Open the pom.xml file.

under the project tag add <dependencies> as another tag, and google for the Maven dependencies. I used this to search.

So after getting the dependency create another tag dependency inside <dependencies> tag.

So ultimately it will look something like this.

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>doc-examples</groupId>
  <artifactId>lambda-java-example</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>lambda-java-example</name>
  <dependencies>
      <!-- https://mvnrepository.com/artifact/com.amazonaws/aws-lambda-java-core -->
    <dependency>
        <groupId>com.amazonaws</groupId>
        <artifactId>aws-lambda-java-core</artifactId>
        <version>1.0.0</version>
    </dependency>
  </dependencies>
</project>

Hope it helps.

Why can't I define a static method in a Java interface?

Well, without generics, static interfaces are useless because all static method calls are resolved at compile time. So, there's no real use for them.

With generics, they have use -- with or without a default implementation. Obviously there would need to be overriding and so on. However, my guess is that such usage wasn't very OO (as the other answers point out obtusely) and hence wasn't considered worth the effort they'd require to implement usefully.

Is an empty href valid?

While it may be completely valid HTML to not include an href, especially with an onclick handler, there are some things to consider: it will not be keyboard-focusable without having a tabindex value set. Furthermore, this will be inaccessible to screenreader software using Internet Explorer, as IE will report through the accessibility interfaces that any anchor element without an href attribute as not-focusable, regardless of whether the tabindex has been set.

So while the following may be completely valid:

<a class="arrow">Link content</a>

It's far better to explicitly add a null-effect href attribute

<a href="javascript:void(0);" class="arrow">Link content</a>

For full support of all users, if you're using the class with CSS to render an image, you should also include some text content, such as the title attribute to provide a textual description of what's going on.

<a href="javascript:void(0);" class="arrow" title="Go to linked content">Link content</a>

Setting up an MS-Access DB for multi-user access

The first thing to do (if not already done) is to split your database into a front end (with all the forms/reports etc) and a back end(with all the data). The second thing is to setup version control on the front end.

The way I have done that in a lot of my databases is to have the users run a small “jumper” database to open the main database. This jumper does the following things

• Checks to see if the user has the database on their C drive

• If they do not then install and run

• If they do then check what version they have

• If the version numbers do not match then copy down the latest version

• Open the database

This whole checking process normally takes under half a second. Using this model you can do all your development on a separate database then when you are ready to “release” you just put the new mde up onto the network share and the next time the user opens the jumper the latest version is copied down.

There are also other things to think about in multiuser database and it might be worth checking for the common mistakes such as binding a form to a whole table etc

How do I pass a URL with multiple parameters into a URL?

You are missing the ? in the second URL (Also, it should be URL-encoded to be %3F).

Also, I believe that the remaining & need to be URL, not HTML-encoded. Change &second=12&third=5 to %26second=12%26third=5 and everything should just work.

This:

&u=http://www.foobar.com/first=12&amp;sec=25&amp;position=2

should be:

&u=http://www.foobar.com/%3Ffirst=12%26sec=25%26position=2

determine DB2 text string length

This will grab records with strings (in the fieldName column) that are 10 characters long:

 select * from table where length(fieldName)=10

HTML5 <video> element on Android

I've just done some experimentation with this, and from what I can tell you need three things:

You must not use the type attribute when calling the video.
You must manually call video.play()
The video must be encoded to some quite strict parameters; using the iPhone setting on Handbrake with the 'Web Optimized' button checked usually does the trick.

Have a look at the demo on this page: http://broken-links.com/tests/video/

This works, AFAIK, in all video-enabled desktop browsers, iPhone and Android.

Here's the markup:

<video id="video" autobuffer height="240" width="360">
<source src="BigBuck.m4v">
<source src="BigBuck.webm" type="video/webm">
<source src="BigBuck.theora.ogv" type="video/ogg">
</video>

And I have this in the JS:

var video = document.getElementById('video');
video.addEventListener('click',function(){
  video.play();
},false);

I tested this on a Samsung Galaxy S and it works fine.

unix sort descending order

The presence of the n option attached to the -k5 causes the global -r option to be ignored for that field. You have to specify both n and r at the same level (globally or locally).

sort -t $'\t' -k5,5rn

sort -rn -t $'\t' -k5,5

regular expression to match exactly 5 digits

I am reading a text file and want to use regex below to pull out numbers with exactly 5 digit, ignoring alphabets.

Try this...

var str = 'f 34 545 323 12345 54321 123456',
    matches = str.match(/\b\d{5}\b/g);

console.log(matches); // ["12345", "54321"]

jsFiddle.

The word boundary \b is your friend here.

Update

My regex will get a number like this 12345, but not like a12345. The other answers provide great regexes if you require the latter.

How do I validate a date in rails?

A bit late here, but thanks to "How do I validate a date in rails?" I managed to write this validator, hope is useful to somebody:

Inside your model.rb

validate :date_field_must_be_a_date_or_blank

# If your field is called :date_field, use :date_field_before_type_cast
def date_field_must_be_a_date_or_blank
  date_field_before_type_cast.to_date
rescue ArgumentError
  errors.add(:birthday, :invalid)
end

When to use malloc for char pointers

malloc for single chars or integers and calloc for dynamic arrays. ie pointer = ((int *)malloc(sizeof(int)) == NULL), you can do arithmetic within the brackets of malloc but you shouldnt because you should use calloc which has the definition of void calloc(count, size)which means how many items you want to store ie count and size of data ie int , char etc.

Property [title] does not exist on this collection instance

A person might get this while working with factory functions, so I can confirm this is valid syntax:

$user = factory(User::class, 1)->create()->first();

You might see the collection instance error if you do something like:

$user = factory(User::class, 1)->create()->id;

so change it to:

$user = factory(User::class, 1)->create()->first()->id;

Visual Studio Code cannot detect installed git

I found that i had git: false in settings.json. Changed it to true and works now.

Give column name when read csv file pandas

I'd do it like this:

colnames=['TIME', 'X', 'Y', 'Z'] 
user1 = pd.read_csv('dataset/1.csv', names=colnames, header=None)

How to create a link to another PHP page

echo "<a href='index.php'>Index Page</a>";

if you wanna use html tag like anchor tag you have to put in echo

How to install grunt and how to build script with it

To setup GruntJS build here is the steps:

Make sure you have setup your package.json or setup new one:
```
npm init
```
Install Grunt CLI as global:
```
npm install -g grunt-cli
```
Install Grunt in your local project:
```
npm install grunt --save-dev
```
Install any Grunt Module you may need in your build process. Just for sake of this sample I will add Concat module for combining files together:
```
npm install grunt-contrib-concat --save-dev
```

Now you need to setup your Gruntfile.js which will describe your build process. For this sample I just combine two JS files file1.js and file2.js in the js folder and generate app.js:

module.exports = function(grunt) {

    // Project configuration.
    grunt.initConfig({
        concat: {
            "options": { "separator": ";" },
            "build": {
                "src": ["js/file1.js", "js/file2.js"],
                "dest": "js/app.js"
            }
        }
    });

    // Load required modules
    grunt.loadNpmTasks('grunt-contrib-concat');

    // Task definitions
    grunt.registerTask('default', ['concat']);
};

Now you'll be ready to run your build process by following command:
```
grunt
```

I hope this give you an idea how to work with GruntJS build.

NOTE:

You can use grunt-init for creating Gruntfile.js if you want wizard-based creation instead of raw coding for step 5.

To do so, please follow these steps:

npm install -g grunt-init
git clone https://github.com/gruntjs/grunt-init-gruntfile.git ~/.grunt-init/gruntfile
grunt-init gruntfile

For Windows users: If you are using cmd.exe you need to change ~/.grunt-init/gruntfile to %USERPROFILE%\.grunt-init\. PowerShell will recognize the ~ correctly.

Can Json.NET serialize / deserialize to / from a stream?

UPDATE: This no longer works in the current version, see below for correct answer (no need to vote down, this is correct on older versions).

Use the JsonTextReader class with a StreamReader or use the JsonSerializer overload that takes a StreamReader directly:

var serializer = new JsonSerializer();
serializer.Deserialize(streamReader);

Create a new txt file using VB.NET

You could just use this

FileOpen(1, "C:\my files\2010\SomeFileName.txt", OpenMode.Output)
FileClose(1)

This opens the file replaces whatever is in it and closes the file.

MetadataException when using Entity Framework Entity Connection

Found the problem.

The standard metadata string looks like this:

metadata=res://*/Model.csdl|res://*/Model.ssdl|res://*/Model.msl

And this works fine in most cases. However, in some (including mine) Entity Framework get confused and does not know which dll to look in. Therefore, change the metadata string to:

metadata=res://nameOfDll/Model.csdl|res://nameOfDll/Model.ssdl|res://nameOfDll/Model.msl

And it will work. It was this link that got me on the right track:

http://itstu.blogspot.com/2008/07/to-load-specified-metadata-resource.html

Although I had the oposite problem, did not work in unit test, but worked in service.

Log exception with traceback

Heres a simple example taken from the python 2.6 documentation:

import logging
LOG_FILENAME = '/tmp/logging_example.out'
logging.basicConfig(filename=LOG_FILENAME,level=logging.DEBUG,)

logging.debug('This message should go to the log file')

Display back button on action bar

In updated version getActionBar() does not work!

Instead, you can do this by this way

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ActionBar actionBar = getSupportActionBar();
        actionBar.setDisplayHomeAsUpEnabled(true);
    }

add back button in android title bar this helps you in 2020

How to get two or more commands together into a batch file

You can use the following command. The SET will set the input from the user console to the variable comment and then you can use that variable using %comment%

SET /P comment=Comment: 
echo %comment%
pause

Parse json string to find and element (key / value)

Use a JSON parser, like JSON.NET

string json = "{ \"Atlantic/Canary\": \"GMT Standard Time\", \"Europe/Lisbon\": \"GMT Standard Time\", \"Antarctica/Mawson\": \"West Asia Standard Time\", \"Etc/GMT+3\": \"SA Eastern Standard Time\", \"Etc/GMT+2\": \"UTC-02\", \"Etc/GMT+1\": \"Cape Verde Standard Time\", \"Etc/GMT+7\": \"US Mountain Standard Time\", \"Etc/GMT+6\": \"Central America Standard Time\", \"Etc/GMT+5\": \"SA Pacific Standard Time\", \"Etc/GMT+4\": \"SA Western Standard Time\", \"Pacific/Wallis\": \"UTC+12\", \"Europe/Skopje\": \"Central European Standard Time\", \"America/Coral_Harbour\": \"SA Pacific Standard Time\", \"Asia/Dhaka\": \"Bangladesh Standard Time\", \"America/St_Lucia\": \"SA Western Standard Time\", \"Asia/Kashgar\": \"China Standard Time\", \"America/Phoenix\": \"US Mountain Standard Time\", \"Asia/Kuwait\": \"Arab Standard Time\" }";
var data = (JObject)JsonConvert.DeserializeObject(json);
string timeZone = data["Atlantic/Canary"].Value<string>();

Dynamically display a CSV file as an HTML table on a web page

Just improved phihag's code because it runs into a infinite loop if file not exists.

<?php

$filename = "so-csv.csv";

echo "<html><body><table>\n\n";

if (file_exists($filename)) {
$f = fopen($filename, "r");
while (($line = fgetcsv($f)) !== false) {
        echo "<tr>";
        foreach ($line as $cell) {
                echo "<td>" . htmlspecialchars($cell) . "</td>";
        }
        echo "</tr>\n";
}
fclose($f);
}

else{ echo "<tr><td>No file exists ! </td></tr>" ;}
echo "\n</table></body></html>";
?>

Filter an array using a formula (without VBA)

Today, in Office 365, Excel has so called 'array functions'. The filter function does exactly what you want. No need to use CTRL+SHIFT+ENTER anymore, a simple enter will suffice.

In Office 365, your problem would be simply solved by using:

=VLOOKUP(A3, FILTER(A2:C6, B2:B6="B"), 3, FALSE)

Facebook OAuth "The domain of this URL isn't included in the app's domain"

Make sure your app is public. Click on + Add product Now go to products => Facebook Login Now do the following:

Valid OAuth redirect URIs : example.com/

Deauthorize Callback URL : https://example.com/facebookapp

How to use the command update-alternatives --config java

Have a look at https://wiki.debian.org/JavaPackage At the bottom of this page an other method is descibed using a command from the java-common package

How to kill an Android activity when leaving it so that it cannot be accessed from the back button?

Add this attribute to you activity in manifest file. android:noHistory="true"

How do I read / convert an InputStream into a String in Java?

String inputStreamToString(InputStream inputStream, Charset charset) throws IOException {
    try (
            final StringWriter writer = new StringWriter();
            final InputStreamReader reader = new InputStreamReader(inputStream, charset)
        ) {
        reader.transferTo(writer);
        return writer.toString();
    }
}

pure Java standard library solution - no libs
since Java 10 - Reader#transferTo(java.io.Writer)
loopless solution
no new line character handling

There is no ViewData item of type 'IEnumerable<SelectListItem>' that has the key 'xxx'

I had same error, I think the problem is that the error text is confusing, because its giving a false key name.

In your case It should say "There is no ViewData item of type 'IEnumerable' that has the key "Submarkets"".

My error was a misspelling in the view code (your "Submarkets"), but the error text made me go crazy.

I post this answer because I want to say people looking for this error, like I was, that the problem is that its not finding the IENumerable, but in the var that its supposed to look for it ("Submarkets" in this case), not in the one showed in error ("submarket_0").

Accepted answer is very interesting, but as you said the convention is applied if you dont specify the 2nd parameter, in this case it was specified, but the var was not found (in your case because the viewdata had not it, in my case because I misspelled the var name)

Hope this helps!

How do I get console input in javascript?

In plain JavaScript, simply use response = readline() after printing a prompt.

In Node.js, you'll need to use the readline module: const readline = require('readline')

Can't concatenate 2 arrays in PHP

Use array_merge()
See the documentation here:
http://php.net/manual/en/function.array-merge.php

Merges the elements of one or more arrays together so that the values of one are appended to the end of the previous one. It returns the resulting array.

What does "zend_mm_heap corrupted" mean

In my case, the cause for this error was one of the arrays was becoming very big. I've set my script to reset the array on every iteration and that sorted the problem.

How to check if an array value exists?

<?php
if (in_array('your_variable', $Your_array)) {
    $redImg = 'true code here';
} else {
    $redImg = 'false code here';
} 
?>

Security of REST authentication schemes

A previous answer only mentioned SSL in the context of data transfer and didn't actually cover authentication.

You're really asking about securely authenticating REST API clients. Unless you're using TLS client authentication, SSL alone is NOT a viable authentication mechanism for a REST API. SSL without client authc only authenticates the server, which is irrelevant for most REST APIs because you really want to authenticate the client.

If you don't use TLS client authentication, you'll need to use something like a digest-based authentication scheme (like Amazon Web Service's custom scheme) or OAuth 1.0a or even HTTP Basic authentication (but over SSL only).

These schemes authenticate that the request was sent by someone expected. TLS (SSL) (without client authentication) ensures that the data sent over the wire remains untampered. They are separate - but complementary - concerns.

For those interested, I've expanded on an SO question about HTTP Authentication Schemes and how they work.

Onclick CSS button effect

This is a press down button example I've made:

<div>
    <form id="forminput" action="action" method="POST">
       ...
    </form>
    <div style="right: 0px;bottom: 0px;position: fixed;" class="thumbnail">
        <div class="image">
            <a onclick="document.getElementById('forminput').submit();">
                <img src="images/button.png" alt="Some awesome text">
            </a>
        </div>
    </div>
</div>

the CSS file:

.thumbnail {
    width: 128px;
    height: 128px;
}

.image {
    width: 100%;
    height: 100%;    
}

.image img {
    -webkit-transition: all .25s ease; /* Safari and Chrome */
    -moz-transition: all .25s ease; /* Firefox */
    -ms-transition: all .25s ease; /* IE 9 */
    -o-transition: all .25s ease; /* Opera */
    transition: all .25s ease;
    max-width: 100%;
    max-height: 100%;
}

.image:hover img {
    -webkit-transform:scale(1.05); /* Safari and Chrome */
    -moz-transform:scale(1.05); /* Firefox */
    -ms-transform:scale(1.05); /* IE 9 */
    -o-transform:scale(1.05); /* Opera */
     transform:scale(1.05);
}

.image:active img {
    -webkit-transform:scale(.95); /* Safari and Chrome */
    -moz-transform:scale(.95); /* Firefox */
    -ms-transform:scale(.95); /* IE 9 */
    -o-transform:scale(.95); /* Opera */
     transform:scale(.95);
}

Enjoy it!

How does true/false work in PHP?

PHP uses weak typing (which it calls 'type juggling'), which is a bad idea (though that's a conversation for another time). When you try to use a variable in a context that requires a boolean, it will convert whatever your variable is into a boolean, according to some mostly arbitrary rules available here: http://www.php.net/manual/en/language.types.boolean.php#language.types.boolean.casting

auto run a bat script in windows 7 at login

To run the batch file when the VM user logs in:

Drag the shortcut--the one that's currently on your desktop--(or the batch file itself) to Start - All Programs - Startup. Now when you login as that user, it will launch the batch file.

Another way to do the same thing is to save the shortcut or the batch file in %AppData%\Microsoft\Windows\Start Menu\Programs\Startup\.

As far as getting it to run full screen, it depends a bit what you mean. You can have it launch maximized by editing your batch file like this:

start "" /max "C:\Program Files\Oracle\VirtualBox\VirtualBox.exe" --comment "VM" --startvm "12dada4d-9cfd-4aa7-8353-20b4e455b3fa"

But if VirtualBox has a truly full-screen mode (where it hides even the taskbar), you'll have to look for a command-line parameter on VirtualBox.exe. I'm not familiar with that product.

Getting current directory in VBScript

simple:

scriptdir = replace(WScript.ScriptFullName,WScript.ScriptName,"")

java.lang.OutOfMemoryError: GC overhead limit exceeded

If you have java8, and you can use the G1 Garbage Collector, then run your application with:

 -XX:+UseG1GC -XX:+UseStringDeduplication

This tells the G1 to find similar Strings and keep only one of them in memory, and the others are only a pointer to that String in memory.

This is useful when you have a lot of repeated strings. This solution may or not work and depends on each application.

More info on:
https://blog.codecentric.de/en/2014/08/string-deduplication-new-feature-java-8-update-20-2/ http://java-performance.info/java-string-deduplication/

How to merge many PDF files into a single one?

There are lots of free tools that can do this.

I use PDFTK (a open source cross-platform command-line tool) for things like that.

Node.js: for each … in not working

Unfortunately node does not support for each ... in, even though it is specified in JavaScript 1.6. Chrome uses the same JavaScript engine and is reported as having a similar shortcoming.

You'll have to settle for array.forEach(function(item) { /* etc etc */ }).

EDIT: From Google's official V8 website:

V8 implements ECMAScript as specified in ECMA-262.

On the same MDN website where it says that for each ...in is in JavaScript 1.6, it says that it is not in any ECMA version - hence, presumably, its absence from Node.

How to find out which JavaScript events fired?

Looks like Firebug (Firefox add-on) has the answer:

open Firebug
right click the element in HTML tab
click Log Events
enable Console tab
click Persist in Console tab (otherwise Console tab will clear after the page is reloaded)
select Closed (manually)

there will be something like this in Console tab:

...
mousemove clientX=1097, clientY=292
popupshowing
mousedown clientX=1097, clientY=292
focus
mouseup clientX=1097, clientY=292
click clientX=1097, clientY=292
mousemove clientX=1096, clientY=293
...

Source: Firebug Tip: Log Events

CMake link to external library

arrowdodger's answer is correct and preferred on many occasions. I would simply like to add an alternative to his answer:

You could add an "imported" library target, instead of a link-directory. Something like:

# Your-external "mylib", add GLOBAL if the imported library is located in directories above the current.
add_library( mylib SHARED IMPORTED )
# You can define two import-locations: one for debug and one for release.
set_target_properties( mylib PROPERTIES IMPORTED_LOCATION ${CMAKE_BINARY_DIR}/res/mylib.so )

And then link as if this library was built by your project:

TARGET_LINK_LIBRARIES(GLBall mylib)

Such an approach would give you a little more flexibility: Take a look at the add_library( ) command and the many target-properties related to imported libraries.

I do not know if this will solve your problem with "updated versions of libs".

Get the first element of each tuple in a list in Python

res_list = [x[0] for x in rows]

c.f. http://docs.python.org/3/tutorial/datastructures.html#list-comprehensions

For a discussion on why to prefer comprehensions over higher-order functions such as map, go to http://www.artima.com/weblogs/viewpost.jsp?thread=98196.

Bootstrap 3 unable to display glyphicon properly

This is the official documentation supporting the above answers.

Changing the icon font location Bootstrap assumes icon font files will be located in the ../fonts/ directory, relative to the compiled CSS files. Moving or renaming those font files means updating the CSS in one of three ways: Change the @icon-font-path and/or @icon-font-name variables in the source Less files. Utilize the relative URLs option provided by the Less compiler. Change the url() paths in the compiled CSS. Use whatever option best suits your specific development setup.

Other than this one mistake the new users would do is, after downloading the bootstrap zip from the official website. They would tend to skip the fonts folder for copying in their dev setup. So missing fonts folder can also lead to this problem

Get year, month or day from numpy datetime64

There should be an easier way to do this, but, depending on what you're trying to do, the best route might be to convert to a regular Python datetime object:

datetime64Obj = np.datetime64('2002-07-04T02:55:41-0700')
print datetime64Obj.astype(object).year
# 2002
print datetime64Obj.astype(object).day
# 4

Based on comments below, this seems to only work in Python 2.7.x and Python 3.6+

How to margin the body of the page (html)?

You need to use css. It's how modern web design gets things done.

This is a basic css walk through.

Your html file would be like:

(really simple html)

    <html>
    <head>
    <link rel="stylesheet" type="text/css" href="mystyle.css" />
    </head>
    <body>
    </body>
    <html>

Your css file (mystyle.css) would look like:

body 
{
 margin-top:0px;
 margin-left:0px;
 margin-right:0px;

}

The type arguments for method cannot be inferred from the usage

For those who are wondering why this works in Java but not C#, consider what happens if some doof wrote this class:

public class Trololol : ISignatur<bool>, ISignatur<int>{
    Type ISignatur<bool>.Type => typeof(bool);
    Type ISignatur<int>.Type => typeof(int);
}

How is the compiler supposed to resolve var access = service.Get(new Trololol())? Both int and bool are valid.

The reason this implicit resolution works in Java likely has to do with Erasure and how Java will throw a fit if you try to implement an interface with two or more different type arguments. Such a class is simply not allowed in Java, but is just fine in C#.

How to make IPython notebook matplotlib plot inline

I used %matplotlib inline in the first cell of the notebook and it works. I think you should try:

%matplotlib inline

import matplotlib
import numpy as np
import matplotlib.pyplot as plt

You can also always start all your IPython kernels in inline mode by default by setting the following config options in your config files:

c.IPKernelApp.matplotlib=<CaselessStrEnum>
  Default: None
  Choices: ['auto', 'gtk', 'gtk3', 'inline', 'nbagg', 'notebook', 'osx', 'qt', 'qt4', 'qt5', 'tk', 'wx']
  Configure matplotlib for interactive use with the default matplotlib backend.

Text that shows an underline on hover

You just need to specify text-decoration: underline; with pseudo-class :hover.

HTML

<span class="underline-on-hover">Hello world</span>

CSS

.underline-on-hover:hover {
    text-decoration: underline;
}

I have whipped up a working Code Pen Demo.

How do you convert a C++ string to an int?

in "stdapi.h"

StrToInt

This function tells you the result, and how many characters participated in the conversion.

How to convert CSV to JSON in Node.js

Using ES6

const toJSON = csv => {
    const lines = csv.split('\n')
    const result = []
    const headers = lines[0].split(',')

    lines.map(l => {
        const obj = {}
        const line = l.split(',')

        headers.map((h, i) => {
            obj[h] = line[i]
        })

        result.push(obj)
    })

    return JSON.stringify(result)
}

const csv = `name,email,age
francis,[email protected],33
matty,[email protected],29`

const data = toJSON(csv)

console.log(data)

Output

// [{"name":"name","email":"email","age":"age"},{"name":"francis","email":"[email protected]","age":"33"},{"name":"matty","email":"[email protected]","age":"29"}]

How to pass arguments to Shell Script through docker run

Another option...

To make this works

docker run -d --rm $IMG_NAME "bash:command1&&command2&&command3"

in dockerfile

ENTRYPOINT ["/entrypoint.sh"]

in entrypoint.sh

#!/bin/sh

entrypoint_params=$1
printf "==>[entrypoint.sh] %s\n" "entry_point_param is $entrypoint_params"

PARAM1=$(echo $entrypoint_params | cut -d':' -f1) # output is 1 must be 'bash' it     will be tested    
PARAM2=$(echo $entrypoint_params | cut -d':' -f2) # the real command separated by     &&

printf "==>[entrypoint.sh] %s\n" "PARAM1=$PARAM1"
printf "==>[entrypoint.sh] %s\n" "PARAM2=$PARAM2"

if [ "$PARAM1" = "bash" ];
then
    printf "==>[entrypoint.sh] %s\n" "about to running $PARAM2 command"
    echo $PARAM2 | tr '&&' '\n' | while read cmd; do
        $cmd
    done    
fi

Android Fatal signal 11 (SIGSEGV) at 0x636f7d89 (code=1). How can it be tracked down?

I've encountered this error when I tried to access the 'canvas' outside of onDraw()

    private Canvas canvas;

    @Override
    protected void onDraw(Canvas canvas) {
        this.canvas = canvas;
        ....... }

    private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
        @Override
        public boolean onScale(ScaleGestureDetector detector) { 
            canvas.save(); // here

A very bad practice :/

How can I get the console logs from the iOS Simulator?

If you are using Swift, remember that println will only print to the debug log (which appears in xCode's debug area). If you want to print to system.log, you have to use NSLog as in the old days.

Then you can view the simulator log via its menu, Debug > Open System Log... (cmd + /)

querySelector, wildcard element match?

I just wrote this short script; seems to work.

/**
 * Find all the elements with a tagName that matches.
 * @param {RegExp} regEx  regular expression to match against tagName
 * @returns {Array}       elements in the DOM that match
 */
function getAllTagMatches(regEx) {
  return Array.prototype.slice.call(document.querySelectorAll('*')).filter(function (el) { 
    return el.tagName.match(regEx);
  });
}
getAllTagMatches(/^di/i); // Returns an array of all elements that begin with "di", eg "div"

Read and Write CSV files including unicode with Python 2.7

Make sure you encode and decode as appropriate.

This example will roundtrip some example text in utf-8 to a csv file and back out to demonstrate:

# -*- coding: utf-8 -*-
import csv

tests={'German': [u'Straße',u'auslösen',u'zerstören'], 
       'French': [u'français',u'américaine',u'épais'], 
       'Chinese': [u'???',u'??',u'???']}

with open('/tmp/utf.csv','w') as fout:
    writer=csv.writer(fout)    
    writer.writerows([tests.keys()])
    for row in zip(*tests.values()):
        row=[s.encode('utf-8') for s in row]
        writer.writerows([row])

with open('/tmp/utf.csv','r') as fin:
    reader=csv.reader(fin)
    for row in reader:
        temp=list(row)
        fmt=u'{:<15}'*len(temp)
        print fmt.format(*[s.decode('utf-8') for s in temp])

Prints:

German         Chinese        French         
Straße         ???            français       
auslösen       ??             américaine     
zerstören      ???            épais

What is N-Tier architecture?

from https://docs.microsoft.com/en-us/azure/architecture/guide/architecture-styles/n-tier

An N-tier architecture divides an application tires into logical tiresand physical tiers mainly and their are divide to sub parts.

Layers are a way to separate responsibilities and manage dependencies. Each layer has a specific responsibility. A higher layer can use services in a lower layer, but not the other way around.

Tiers are physically separated, running on separate machines. A tier can call to another tier directly, or use asynchronous messaging (message queue). Although each layer might be hosted in its own tier, that's not required. Several layers might be hosted on the same tier. Physically separating the tiers improves scalability and resiliency, but also adds latency from the additional network communication.

A traditional three-tier application has a presentation tier, a middle tier, and a database tier. The middle tier is optional. More complex applications can have more than three tiers. The diagram above shows an application with two middle tiers, encapsulating different areas of functionality.

An N-tier application can have a closed layer architecture or an open layer architecture:

In a closed layer architecture, a layer can only call the next layer immediately down.
In an open layer architecture, a layer can call any of the layers below it.

A closed layer architecture limits the dependencies between layers. However, it might create unnecessary network traffic, if one layer simply passes requests along to the next layer.

OSError: [Errno 8] Exec format error

Have you tried this?

Out = subprocess.Popen('/usr/local/bin/script hostname = actual_server_name -p LONGLIST'.split(), shell=False,stdout=subprocess.PIPE,stderr=subprocess.PIPE)

Edited per the apt comment from @J.F.Sebastian

':app:lintVitalRelease' error when generating signed apk

if you want to find out the exact error go to the following path in your project: /app/build/reports/lint-results-release-fatal.html(or .xml). The easiest way is if you go to the xml file, it will show you exactly what the error is including its position of the error in your either java class or xml file. Turning off the lint checks is not a good idea, they're there for a reason. Instead, go to:

    /app/build/reports/lint-results-release-fatal.html or 
    /app/build/reports/lint-results-release-fatal.xml

and fix it.

Adding and reading from a Config file

Right click on the project file -> Add -> New Item -> Application Configuration File. This will add an app.config (or web.config) file to your project.
The ConfigurationManager class would be a good start. You can use it to read different configuration values from the configuration file.

I suggest you start reading the MSDN document about Configuration Files.

Cannot make a static reference to the non-static method

This question is not new and existing answers give some good theoretical background. I just want to add a more pragmatic answer.

getText is a method of the Context abstract class and in order to call it, one needs an instance of it's subclass (Activity, Service, Application or other). The problem is, that the public static final variables are initialized before any instance of Context is created.

There are several ways to solve this:

Make the variable a member variable (field) of the Activity or other subclass of Context by removing the static modifier and placing it within the class body;
Keep it static and delay the initialization to a later point (e.g. in the onCreate method);
Make it a local variable in the place of actual usage.

How does ifstream's eof() work?

-1 is get's way of saying you've reached the end of file. Compare it using the std::char_traits<char>::eof() (or std::istream::traits_type::eof()) - avoid -1, it's a magic number. (Although the other one is a bit verbose - you can always just call istream::eof)

The EOF flag is only set once a read tries to read past the end of the file. If I have a 3 byte file, and I only read 3 bytes, EOF is false, because I've not tried to read past the end of the file yet. While this seems confusing for files, which typically know their size, EOF is not known until a read is attempted on some devices, such as pipes and network sockets.

The second example works as inf >> foo will always return inf, with the side effect of attempt to read something and store it in foo. inf, in an if or while, will evaluate to true if the file is "good": no errors, no EOF. Thus, when a read fails, inf evaulates to false, and your loop properly aborts. However, take this common error:

while(!inf.eof())  // EOF is false here
{
    inf >> x;      // read fails, EOF becomes true, x is not set
    // use x       // we use x, despite our read failing.
}

However, this:

while(inf >> x)  // Attempt read into x, return false if it fails
{
    // will only be entered if read succeeded.
}

Which is what we want.

how to display a javascript var in html body

You can do the same on document ready event like below

<script>
$(document).ready(function(){
 var number = 112;
    $("yourClass/Element/id...").html(number);
// $("yourClass/Element/id...").text(number);
});
</script>

or you can simply do it using document.write(number);.

MySQL FULL JOIN?

Try This:

(SELECT p.LastName, p.FirstName, o.OrderNo
 FROM   Persons p
   LEFT JOIN Orders o
   ON o.OrderNo = p.P_id
)
UNION
(SELECT p.LastName, p.FirstName, o.OrderNo
 FROM   Persons p
   RIGHT JOIN Orders o
   ON o.OrderNo = p.P_id
);

+----------+-----------+---------+
| LastName | FirstName | OrderNo |
+----------+-----------+---------+
| Singh    | Shashi    |       1 |
| Yadav    | Sunil     |    NULL |
| Singh    | Satya     |    NULL |
| Jain     | Ankit     |    NULL |
| NULL     | NULL      |      11 |
| NULL     | NULL      |      12 |
| NULL     | NULL      |      13 |
+----------+-----------+---------+

JavaScript Uncaught ReferenceError: jQuery is not defined; Uncaught ReferenceError: $ is not defined

You did not include jquery library. In jsfiddle its already there. Just include this line in your head section.

 <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js">

Python read in string from file and split it into values

I would do something like:

filename = "mynumbers.txt"
mynumbers = []
with open(filename) as f:
    for line in f:
        mynumbers.append([int(n) for n in line.strip().split(',')])
for pair in mynumbers:
    try:
        x,y = pair[0],pair[1]
        # Do Something with x and y
    except IndexError:
        print "A line in the file doesn't have enough entries."

The with open is recommended in http://docs.python.org/tutorial/inputoutput.html since it makes sure files are closed correctly even if an exception is raised during the processing.

Eclipse: Java was started but returned error code=13

This error occurs because your Eclipse version is 64-bit. You should download and install 64-bit JRE and add the path to it in eclipse.ini. For example:

...
--launcher.appendVmargs
-vm
C:\Program Files\Java\jre1.8.0_45\bin\javaw.exe
-vmargs
...

Note: The -vm parameter should be just before -vmargs and the path should be on a separate line. It should be the full path to the javaw.exe file. Do not enclose the path in double quotes (").

If your Eclipse is 32-bit, install a 32-bit JRE and use the path to its javaw.exe file.

Is it possible to CONTINUE a loop from an exception?

How about the ole goto statement (i know, i know, but it works just fine here ;)

DECLARE
   v_attr char(88);
CURSOR  SELECT_USERS IS
SELECT id FROM USER_TABLE
WHERE USERTYPE = 'X';
BEGIN
    FOR user_rec IN SELECT_USERS LOOP    
        BEGIN
            SELECT attr INTO v_attr 
            FROM ATTRIBUTE_TABLE
            WHERE user_id = user_rec.id;            
         EXCEPTION
            WHEN NO_DATA_FOUND THEN
               -- user does not have attribute, continue loop to next record.
               goto end_loop;
         END;

        <<end_loop>>
        null;         
    END LOOP;
END;

Just put end_loop at very end of loop of course. The null can be substituted with a commit maybe or a counter increment maybe, up to you.

how to use php DateTime() function in Laravel 5

I didn't mean to copy the same answer, that is why I didn't accept my own answer.

Actually when I add use DateTime in top of the controller solves this problem.

Remove Android App Title Bar

In your res/values/styles.xml of modern Android Studio projects (2019/2020) you should be able to change the default parent theme

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">

I went one step further and had it look like this

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="colorAccent">@color/colorAccent</item>
    <item name="android:windowFullscreen">true</item>
</style>

This is based on the code generated from the Microsoft PWA builder https://www.pwabuilder.com/

How can I retrieve Id of inserted entity using Entity framework?

You have to set the property of StoreGeneratedPattern to identity and then try your own code.

Or else you can also use this.

using (var context = new MyContext())
{
  context.MyEntities.AddObject(myNewObject);
  context.SaveChanges();

  int id = myNewObject.Id; // Your Identity column ID
}

Getting the source HTML of the current page from chrome extension

Here is my solution:

chrome.runtime.onMessage.addListener(function(request, sender) {
        if (request.action == "getSource") {
            this.pageSource = request.source;
            var title = this.pageSource.match(/<title[^>]*>([^<]+)<\/title>/)[1];
            alert(title)
        }
    });

    chrome.tabs.query({ active: true, currentWindow: true }, tabs => {
        chrome.tabs.executeScript(
            tabs[0].id,
            { code: 'var s = document.documentElement.outerHTML; chrome.runtime.sendMessage({action: "getSource", source: s});' }
        );
    });

Pip install - Python 2.7 - Windows 7

It is possible that in python 2.7 pip is installed by default. if it is not then you can execute

python -m ensurepip --default-pip

This worked for me.

Source: https://docs.python.org/2/installing/

How to install a Notepad++ plugin offline?

as an aside, i Couldnt import the .dll if it was already in the plugins folder. I put it in a temp folder on the C drive, and it worked perfectly.

Regex pattern including all special characters

You have a dash in the middle of the character class, which will mean a character range. Put the dash at the end of the class like so:

[$&+,:;=?@#|'<>.^*()%!-]

Changing the space between each item in Bootstrap navbar

You can change this in your CSS with the property padding:

.navbar-nav > li{
  padding-left:30px;
  padding-right:30px;
}

Also you can set margin

.navbar-nav > li{
  margin-left:30px;
  margin-right:30px;
}

Curl to return http status code along with the response

Append a line "http_code:200" at the end, and then grep for the keyword "http_code:" and extract the response code.

result=$(curl -w "\nhttp_code:%{http_code}" http://localhost)

echo "result: ${result}"   #the curl result with "http_code:" at the end

http_code=$(echo "${result}" | grep 'http_code:' | sed 's/http_code://g') 

echo "HTTP_CODE: ${http_code}"  #the http response code

In this case, you can still use the non-silent mode / verbose mode to get more information about the request such as the curl response body.

Is it possible to get all arguments of a function as single object inside that function?

Similar answer to Gunnar, with more complete example: You can even transparently return the whole thing:

function dumpArguments(...args) {
  for (var i = 0; i < args.length; i++)
    console.log(args[i]);
  return args;
}

dumpArguments("foo", "bar", true, 42, ["yes", "no"], { 'banana': true });

Output:

foo
bar
true
42
["yes","no"]
{"banana":true}

Programs & Examples On #Web application project