Programs & Examples On #Build dependencies

Xcode : Adding a project as a build dependency

Tough one for a newbie like me - here is a screenshot that describes it.
Xcode 10.2.1

enter image description here

Bootstrap modal z-index

I found this question as I had a similar problem. While data-backdrop does "solve" the issue; I found another problem in my markup.

I had the button which launched this modal and the modal dialog itself was in the footer. The problem is that the footer was defined as navbar_fixed_bottom, and that contained position:fixed.

After I moved the dialog outside of the fixed section, everything worked as expected.

Using "margin: 0 auto;" in Internet Explorer 8

One more time: we all hate IE!

<div style="width:100%;background-color:blue;">
    <div style="margin:0 auto;width:300px;background-color:red;">
        Not Working
    </div>
</div>

<div style="width:100%;background-color:green;text-align:center;">
    <div style="margin:0 auto;width:300px;background-color:orange;text-align:left;">
        Working, but dumb that you have to use text-align
    </div>
</div>

React-router urls don't work when refreshing or writing manually

I found the solution for my SPA with react router (Apache). Just add in .htaccess

<IfModule mod_rewrite.c>

  RewriteEngine On
  RewriteBase /
  RewriteRule ^index\.html$ - [L]
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteCond %{REQUEST_FILENAME} !-l
  RewriteRule . /index.html [L]

</IfModule>

source: https://gist.github.com/alexsasharegan/173878f9d67055bfef63449fa7136042

How can I get a value from a map?

map.at("key") throws exception if missing key

If k does not match the key of any element in the container, the function throws an out_of_range exception.

http://www.cplusplus.com/reference/map/map/at/

Unable to add window -- token android.os.BinderProxy is not valid; is your activity running?

Unable to add window -- token is not valid; is your activity running?

This crash is usually caused by your app trying to display a dialog using a previously-finished Activity as a context. For example, this can happen if an Activity triggers an AsyncTask that tries to display a dialog when it is finished, but the user navigates back from the Activity before the task is completed.

External resources

Android – Displaying Dialogs From Background Threads

Error : BinderProxy@45d459c0 is not valid; is your activity running?

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

Not the answer for this question

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

Example:

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

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

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

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

Explanation from dhke

Execute a command line binary with Node.js

If you don't mind a dependency and want to use promises, child-process-promise works:

installation

npm install child-process-promise --save

exec Usage

var exec = require('child-process-promise').exec;

exec('echo hello')
    .then(function (result) {
        var stdout = result.stdout;
        var stderr = result.stderr;
        console.log('stdout: ', stdout);
        console.log('stderr: ', stderr);
    })
    .catch(function (err) {
        console.error('ERROR: ', err);
    });

spawn usage

var spawn = require('child-process-promise').spawn;

var promise = spawn('echo', ['hello']);

var childProcess = promise.childProcess;

console.log('[spawn] childProcess.pid: ', childProcess.pid);
childProcess.stdout.on('data', function (data) {
    console.log('[spawn] stdout: ', data.toString());
});
childProcess.stderr.on('data', function (data) {
    console.log('[spawn] stderr: ', data.toString());
});

promise.then(function () {
        console.log('[spawn] done!');
    })
    .catch(function (err) {
        console.error('[spawn] ERROR: ', err);
    });

How to sort a Pandas DataFrame by index?

Dataframes have a sort_index method which returns a copy by default. Pass inplace=True to operate in place.

import pandas as pd
df = pd.DataFrame([1, 2, 3, 4, 5], index=[100, 29, 234, 1, 150], columns=['A'])
df.sort_index(inplace=True)
print(df.to_string())

Gives me:

     A
1    4
29   2
100  1
150  5
234  3

Are there inline functions in java?

Java9 has an "Ahead of time" compiler that does several optimizations at compile-time, rather than runtime, which can be seen as inlining.

Filter array to have unique values

A slight variation on the indexOf method, if you need to filter multiple arrays:

function unique(item, index, array) {
    return array.indexOf(item) == index;
}

Use as such:

arr.filter(unique);

Truncate/round whole number in JavaScript?

Math.trunc() function removes all the fractional digits.

For positive number it behaves exactly the same as Math.floor():

console.log(Math.trunc(89.13349)); // output is 89

For negative numbers it behaves same as Math.ceil():

console.log(Math.trunc(-89.13349)); //output is -89

Priority queue in .Net

You may find useful this implementation: http://www.codeproject.com/Articles/126751/Priority-queue-in-Csharp-with-help-of-heap-data-st.aspx

it is generic and based on heap data structure

Select2 doesn't work when embedded in a bootstrap modal

change select2.css file

z-index: 9998;
...
z-index: 9999;
...
z-index: 10000;

to

z-index: 10000;
...
z-index: 10001;
...
z-index: 10002;

How to lookup JNDI resources on WebLogic?

I just had to update legacy Weblogic 8 app to use a data-source instead of hard-coded JDBC string. Datasource JNDI name on the configuration tab in the Weblogic admin showed: "weblogic.jdbc.ESdatasource", below are two ways that worked:

      Context ctx = new InitialContext();
      DataSource dataSource;

      try {
        dataSource = (DataSource) ctx.lookup("weblogic.jdbc.ESdatasource");
        response.getWriter().println("A " +dataSource);
      }catch(Exception e) {
        response.getWriter().println("A " + e.getMessage() + e.getCause());
      }

      //or

      try {
        dataSource = (DataSource) ctx.lookup("weblogic/jdbc/ESdatasource");
        response.getWriter().println("F "+dataSource);
      }catch(Exception e) {
        response.getWriter().println("F " + e.getMessage() + e.getCause());
      }

      //use your datasource
      conn = datasource.getConnection();

That's all folks. No passwords and initial context factory needed from the inside of Weblogic app.

"Prevent saving changes that require the table to be re-created" negative effects

Yes, there are negative effects from this:

If you script out a change blocked by this flag you get something like the script below (all i am turning the ID column in Contact into an autonumbered IDENTITY column, but the table has dependencies). Note potential errors that can occur while the following is running:

  1. Even microsoft warns that this may cause data loss (that comment is auto-generated)!
  2. for a period of time, foreign keys are not enforced.
  3. if you manually run this in ssms and the ' EXEC('INSERT INTO ' fails, and you let the following statements run (which they do by default, as they are split by 'go') then you will insert 0 rows, then drop the old table.
  4. if this is a big table, the runtime of the insert can be large, and the transaction is holding a schema modification lock, so blocks many things.

--

/* To prevent any potential data loss issues, you should review this script in detail before running it outside the context of the database designer.*/

BEGIN TRANSACTION
GO
ALTER TABLE raw.Contact
    DROP CONSTRAINT fk_Contact_AddressType
GO
ALTER TABLE ref.ContactpointType SET (LOCK_ESCALATION = TABLE)
GO
COMMIT
BEGIN TRANSACTION
GO
ALTER TABLE raw.Contact
    DROP CONSTRAINT fk_contact_profile
GO
ALTER TABLE raw.Profile SET (LOCK_ESCALATION = TABLE)
GO
COMMIT
BEGIN TRANSACTION
GO
CREATE TABLE raw.Tmp_Contact
    (
    ContactID int NOT NULL IDENTITY (1, 1),
    ProfileID int NOT NULL,
    AddressType char(2) NOT NULL,
    ContactText varchar(250) NULL
    )  ON [PRIMARY]
GO
ALTER TABLE raw.Tmp_Contact SET (LOCK_ESCALATION = TABLE)
GO
SET IDENTITY_INSERT raw.Tmp_Contact ON
GO
IF EXISTS(SELECT * FROM raw.Contact)
     EXEC('INSERT INTO raw.Tmp_Contact (ContactID, ProfileID, AddressType, ContactText)
        SELECT ContactID, ProfileID, AddressType, ContactText FROM raw.Contact WITH (HOLDLOCK TABLOCKX)')
GO
SET IDENTITY_INSERT raw.Tmp_Contact OFF
GO
ALTER TABLE raw.PostalAddress
    DROP CONSTRAINT fk_AddressProfile
GO
ALTER TABLE raw.MarketingFlag
    DROP CONSTRAINT fk_marketingflag_contact
GO
ALTER TABLE raw.Phones
    DROP CONSTRAINT fk_phones_contact
GO
DROP TABLE raw.Contact
GO
EXECUTE sp_rename N'raw.Tmp_Contact', N'Contact', 'OBJECT' 
GO
ALTER TABLE raw.Contact ADD CONSTRAINT
    Idx_Contact_1 PRIMARY KEY CLUSTERED 
    (
    ProfileID,
    ContactID
    ) 

GO
ALTER TABLE raw.Contact ADD CONSTRAINT
    Idx_Contact UNIQUE NONCLUSTERED 
    (
    ProfileID,
    ContactID
    ) 

GO
CREATE NONCLUSTERED INDEX idx_Contact_0 ON raw.Contact
    (
    AddressType
    ) 
GO
ALTER TABLE raw.Contact ADD CONSTRAINT
    fk_contact_profile FOREIGN KEY
    (
    ProfileID
    ) REFERENCES raw.Profile
    (
    ProfileID
    ) ON UPDATE  NO ACTION 
     ON DELETE  NO ACTION 

GO
ALTER TABLE raw.Contact ADD CONSTRAINT
    fk_Contact_AddressType FOREIGN KEY
    (
    AddressType
    ) REFERENCES ref.ContactpointType
    (
    ContactPointTypeCode
    ) ON UPDATE  NO ACTION 
     ON DELETE  NO ACTION 

GO
COMMIT
BEGIN TRANSACTION
GO
ALTER TABLE raw.Phones ADD CONSTRAINT
    fk_phones_contact FOREIGN KEY
    (
    ProfileID,
    PhoneID
    ) REFERENCES raw.Contact
    (
    ProfileID,
    ContactID
    ) ON UPDATE  NO ACTION 
     ON DELETE  NO ACTION 

GO
ALTER TABLE raw.Phones SET (LOCK_ESCALATION = TABLE)
GO
COMMIT
BEGIN TRANSACTION
GO
ALTER TABLE raw.MarketingFlag ADD CONSTRAINT
    fk_marketingflag_contact FOREIGN KEY
    (
    ProfileID,
    ContactID
    ) REFERENCES raw.Contact
    (
    ProfileID,
    ContactID
    ) ON UPDATE  NO ACTION 
     ON DELETE  NO ACTION 

GO
ALTER TABLE raw.MarketingFlag SET (LOCK_ESCALATION = TABLE)
GO
COMMIT
BEGIN TRANSACTION
GO
ALTER TABLE raw.PostalAddress ADD CONSTRAINT
    fk_AddressProfile FOREIGN KEY
    (
    ProfileID,
    AddressID
    ) REFERENCES raw.Contact
    (
    ProfileID,
    ContactID
    ) ON UPDATE  NO ACTION 
     ON DELETE  NO ACTION 

GO
ALTER TABLE raw.PostalAddress SET (LOCK_ESCALATION = TABLE)
GO
COMMIT

Homebrew: Could not symlink, /usr/local/bin is not writable

This is because the current user is not permitted to write in that path. So, to change r/w (read/write) permissions you can either use 1. terminal, or 2. Graphical "Get Info" window.

1. Using Terminal

Google how to use chmod/chown (change mode/change owner) commands from terminal

2. Using graphical 'Get Info'

You can right click on the folder/file you want to change permissions of, then open Get Info which will show you a window like below at the bottom of which you can easily change r/w permissions: enter image description here

Remember to change the permission back to "read only" after your temporary work, if possible

Creating a "logical exclusive or" operator in Java

Java does have a logical XOR operator, it is ^ (as in a ^ b).

Apart from that, you can't define new operators in Java.

Edit: Here's an example:

public static void main(String[] args) {
    boolean[] all = { false, true };
    for (boolean a : all) {
        for (boolean b: all) {
            boolean c = a ^ b;
            System.out.println(a + " ^ " + b + " = " + c);
        }
    }
}

Output:

false ^ false = false
false ^ true = true
true ^ false = true
true ^ true = false

How to make cross domain request

Do a cross-domain AJAX call

Your web-service must support method injection in order to do JSONP.

Your code seems fine and it should work if your web services and your web application hosted in the same domain.

When you do a $.ajax with dataType: 'jsonp' meaning that jQuery is actually adding a new parameter to the query URL.

For instance, if your URL is http://10.211.2.219:8080/SampleWebService/sample.do then jQuery will add ?callback={some_random_dynamically_generated_method}.

This method is more kind of a proxy actually attached in window object. This is nothing specific but does look something like this:

window.some_random_dynamically_generated_method = function(actualJsonpData) {
    //here actually has reference to the success function mentioned with $.ajax
    //so it just calls the success method like this: 
    successCallback(actualJsonData);
}

Check the following for more information

Make cross-domain ajax JSONP request with jQuery

Path.Combine absolute with relative path strings

For windows universal apps Path.GetFullPath() is not available, you can use the System.Uri class instead:

 Uri uri = new Uri(Path.Combine(@"C:\blah\",@"..\bling"));
 Console.WriteLine(uri.LocalPath);

Oracle: not a valid month

1.

To_Date(To_Char(MaxDate, 'DD/MM/YYYY')) = REP_DATE

is causing the issue. when you use to_date without the time format, oracle will use the current sessions NLS format to convert, which in your case might not be "DD/MM/YYYY". Check this...

SQL> select sysdate from dual;

SYSDATE
---------
26-SEP-12

Which means my session's setting is DD-Mon-YY

SQL> select to_char(sysdate,'MM/DD/YYYY') from dual;

TO_CHAR(SY
----------
09/26/2012


SQL> select to_date(to_char(sysdate,'MM/DD/YYYY')) from dual;
select to_date(to_char(sysdate,'MM/DD/YYYY')) from dual
               *
ERROR at line 1:
ORA-01843: not a valid month

SQL> select to_date(to_char(sysdate,'MM/DD/YYYY'),'MM/DD/YYYY') from dual;

TO_DATE(T
---------
26-SEP-12

2.

More importantly, Why are you converting to char and then to date, instead of directly comparing

MaxDate = REP_DATE

If you want to ignore the time component in MaxDate before comparision, you should use..

trunc(MaxDate ) = rep_date

instead.

==Update : based on updated question.

Rep_Date = 01/04/2009 Rep_Time = 01/01/1753 13:00:00

I think the problem is more complex. if rep_time is intended to be only time, then you cannot store it in the database as a date. It would have to be a string or date to time interval or numerically as seconds (thanks to Alex, see this) . If possible, I would suggest using one column rep_date that has both the date and time and compare it to the max date column directly.

If it is a running system and you have no control over repdate, you could try this.

trunc(rep_date) = trunc(maxdate) and 
to_char(rep_date,'HH24:MI:SS') = to_char(maxdate,'HH24:MI:SS')

Either way, the time is being stored incorrectly (as you can tell from the year 1753) and there could be other issues going forward.

Download image from the site in .NET/C#

Also possible to use DownloadData method

    private byte[] GetImage(string iconPath)
    {
        using (WebClient client = new WebClient())
        {
            byte[] pic = client.DownloadData(iconPath);
            //string checkPath = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments) +@"\1.png";
            //File.WriteAllBytes(checkPath, pic);
            return pic;
        }
    }

Transpose/Unzip Function (inverse of zip)?

>>> original = [('a', 1), ('b', 2), ('c', 3), ('d', 4)]
>>> tuple([list(tup) for tup in zip(*original)])
(['a', 'b', 'c', 'd'], [1, 2, 3, 4])

Gives a tuple of lists as in the question.

list1, list2 = [list(tup) for tup in zip(*original)]

Unpacks the two lists.

SELECT INTO a table variable in T-SQL

You can also use common table expressions to store temporary datasets. They are more elegant and adhoc friendly:

WITH userData (name, oldlocation)
AS
(
  SELECT name, location 
  FROM   myTable    INNER JOIN 
         otherTable ON ...
  WHERE  age>30
)
SELECT * 
FROM   userData -- you can also reuse the recordset in subqueries and joins

Prepare for Segue in Swift

I think the problem is you have to use the ! to unbundle identifier

I have

override func prepareForSegue(segue: UIStoryboardSegue?, sender: AnyObject?) {
        if segue!.identifier == "Details" {
            let viewController:ViewController = segue!.destinationViewController as ViewController
            let indexPath = self.tableView.indexPathForSelectedRow()
            viewController.pinCode = self.exams[indexPath.row]

        }

    }

My understanding is that without the ! you just get a true or false value

css h1 - only as wide as the text

align-self-start, align-self-center... in flexbox

.centercol h1{
    background: #F2EFE9;
    border-left: 3px solid #C6C1B8;
    color: #006BB6;
    display: block;
    align-self: center;
    font-weight: normal;
    font-size: 18px;
    padding: 3px 3px 3px 6px;
}

How to convert from int to string in objective c: example code

Dot grammar maybe more swift!

@(intValueDemo).stringValue 

for example

int intValueDemo  = 1;
//or
NSInteger intValueDemo = 1;

//So you can use dot grammar 
NSLog(@"%@",@(intValueDemo).stringValue);

How can I create an observable with a delay

import * as Rx from 'rxjs/Rx';

We should add the above import to make the blow code to work

Let obs = Rx.Observable
    .interval(1000).take(3);

obs.subscribe(value => console.log('Subscriber: ' + value));

How to display an activity indicator with text on iOS 8 with Swift?

While Esq's answer works, I've added my own implementation which is more in line with good component architecture by separating the view into it's own class. It also uses dynamic blurring introduced in iOS 8.

Here is how mine looks with an image background:

enter image description here

The code for this is encapsulated in it's own UIView class which means you can reuse it whenever you desire.

Updated for Swift 3

Usage

func viewDidLoad() {
  super.viewDidLoad()

  // Create and add the view to the screen.
  let progressHUD = ProgressHUD(text: "Saving Photo")
  self.view.addSubview(progressHUD)
  // All done!

  self.view.backgroundColor = UIColor.black
}

UIView Code

import UIKit

class ProgressHUD: UIVisualEffectView {

  var text: String? {
    didSet {
      label.text = text
    }
  }

  let activityIndictor: UIActivityIndicatorView = UIActivityIndicatorView(activityIndicatorStyle: UIActivityIndicatorViewStyle.gray)
  let label: UILabel = UILabel()
  let blurEffect = UIBlurEffect(style: .light)
  let vibrancyView: UIVisualEffectView

  init(text: String) {
    self.text = text
    self.vibrancyView = UIVisualEffectView(effect: UIVibrancyEffect(blurEffect: blurEffect))
    super.init(effect: blurEffect)
    self.setup()
  }

  required init?(coder aDecoder: NSCoder) {
    self.text = ""
    self.vibrancyView = UIVisualEffectView(effect: UIVibrancyEffect(blurEffect: blurEffect))
    super.init(coder: aDecoder)
    self.setup()
  }

  func setup() {
    contentView.addSubview(vibrancyView)
    contentView.addSubview(activityIndictor)
    contentView.addSubview(label)
    activityIndictor.startAnimating()
  }

  override func didMoveToSuperview() {
    super.didMoveToSuperview()

    if let superview = self.superview {

      let width = superview.frame.size.width / 2.3
      let height: CGFloat = 50.0
      self.frame = CGRect(x: superview.frame.size.width / 2 - width / 2,
                      y: superview.frame.height / 2 - height / 2,
                      width: width,
                      height: height)
      vibrancyView.frame = self.bounds

      let activityIndicatorSize: CGFloat = 40
      activityIndictor.frame = CGRect(x: 5,
                                      y: height / 2 - activityIndicatorSize / 2,
                                      width: activityIndicatorSize,
                                      height: activityIndicatorSize)

      layer.cornerRadius = 8.0
      layer.masksToBounds = true
      label.text = text
      label.textAlignment = NSTextAlignment.center
      label.frame = CGRect(x: activityIndicatorSize + 5,
                           y: 0,
                           width: width - activityIndicatorSize - 15,
                           height: height)
      label.textColor = UIColor.gray
      label.font = UIFont.boldSystemFont(ofSize: 16)
    }
  }

  func show() {
    self.isHidden = false
  }

  func hide() {
    self.isHidden = true
  }
}

Swift 2

An example on how to use it is like this:

override func viewDidLoad() {
    super.viewDidLoad()

    // Create and add the view to the screen.
    let progressHUD = ProgressHUD(text: "Saving Photo")
    self.view.addSubview(progressHUD)
    // All done!

    self.view.backgroundColor = UIColor.blackColor()
}

Here is the UIView code:

import UIKit

class ProgressHUD: UIVisualEffectView {

    var text: String? {
        didSet {
            label.text = text
        }
    }
    let activityIndictor: UIActivityIndicatorView = UIActivityIndicatorView(activityIndicatorStyle: UIActivityIndicatorViewStyle.White)
    let label: UILabel = UILabel()
    let blurEffect = UIBlurEffect(style: .Light)
    let vibrancyView: UIVisualEffectView

    init(text: String) {
        self.text = text
        self.vibrancyView = UIVisualEffectView(effect: UIVibrancyEffect(forBlurEffect: blurEffect))
        super.init(effect: blurEffect)
        self.setup()
    }

    required init(coder aDecoder: NSCoder) {
        self.text = ""
        self.vibrancyView = UIVisualEffectView(effect: UIVibrancyEffect(forBlurEffect: blurEffect))
        super.init(coder: aDecoder)
        self.setup()

    }

    func setup() {
        contentView.addSubview(vibrancyView)
        vibrancyView.contentView.addSubview(activityIndictor)
        vibrancyView.contentView.addSubview(label)
        activityIndictor.startAnimating()
    }

    override func didMoveToSuperview() {
        super.didMoveToSuperview()

        if let superview = self.superview {

            let width = superview.frame.size.width / 2.3
            let height: CGFloat = 50.0
            self.frame = CGRectMake(superview.frame.size.width / 2 - width / 2,
                superview.frame.height / 2 - height / 2,
                width,
                height)
            vibrancyView.frame = self.bounds

            let activityIndicatorSize: CGFloat = 40
            activityIndictor.frame = CGRectMake(5, height / 2 - activityIndicatorSize / 2,
                activityIndicatorSize,
                activityIndicatorSize)

            layer.cornerRadius = 8.0
            layer.masksToBounds = true
            label.text = text
            label.textAlignment = NSTextAlignment.Center
            label.frame = CGRectMake(activityIndicatorSize + 5, 0, width - activityIndicatorSize - 15, height)
            label.textColor = UIColor.grayColor()
            label.font = UIFont.boldSystemFontOfSize(16)
        }
    }

    func show() {
        self.hidden = false
    }

    func hide() {
        self.hidden = true
    }
}

I hope this helps, please feel free to use this code wherever you need.

Warning: #1265 Data truncated for column 'pdd' at row 1

As the message error says, you need to Increase the length of your column to fit the length of the data you are trying to insert (0000-00-00)

EDIT 1:

Following your comment, I run a test table:

mysql> create table testDate(id int(2) not null auto_increment, pdd date default null, primary key(id));
Query OK, 0 rows affected (0.20 sec)

Insertion:

mysql> insert into testDate values(1,'0000-00-00');
Query OK, 1 row affected (0.06 sec)

EDIT 2:

So, aparently you want to insert a NULL value to pdd field as your comment states ? You can do that in 2 ways like this:

Method 1:

mysql> insert into testDate values(2,'');
Query OK, 1 row affected, 1 warning (0.06 sec)

Method 2:

mysql> insert into testDate values(3,NULL);
Query OK, 1 row affected (0.07 sec)

EDIT 3:

You failed to change the default value of pdd field. Here is the syntax how to do it (in my case, I set it to NULL in the start, now I will change it to NOT NULL)

mysql> alter table testDate modify pdd date not null;
Query OK, 3 rows affected, 1 warning (0.60 sec)
Records: 3  Duplicates: 0  Warnings: 1

Android emulator: How to monitor network traffic?

You can start the emulator with the command -avd Adfmf -http-proxy http://SYSTEM_IP:PORT. I used HTTP Analyzer, but it should work for anything else. More details can be found here: http://stick2code.blogspot.in/2014/04/intercept-http-requests-sent-from-app.html

jQuery/JavaScript: accessing contents of an iframe

You can use window.postMessage to call a function between page and his iframe (cross domain or not).

Documentation

page.html

<!DOCTYPE html>
<html>
<head>
    <title>Page with an iframe</title>
    <meta charset="UTF-8" />
    <script src="http://code.jquery.com/jquery-1.10.2.min.js"></script>
    <script>
    var Page = {
        id:'page',
        variable:'This is the page.'
    };

    $(window).on('message', function(e) {
        var event = e.originalEvent;
        if(window.console) {
            console.log(event);
        }
        alert(event.origin + '\n' + event.data);
    });
    function iframeReady(iframe) {
        if(iframe.contentWindow.postMessage) {
            iframe.contentWindow.postMessage('Hello ' + Page.id, '*');
        }
    }
    </script>
</head>
<body>
    <h1>Page with an iframe</h1>
    <iframe src="iframe.html" onload="iframeReady(this);"></iframe>
</body>
</html>

iframe.html

<!DOCTYPE html>
<html>
<head>
    <title>iframe</title>
    <meta charset="UTF-8" />
    <script src="http://code.jquery.com/jquery-1.10.2.min.js"></script>
    <script>
    var Page = {
        id:'iframe',
        variable:'The iframe.'
    };

    $(window).on('message', function(e) {
        var event = e.originalEvent;
        if(window.console) {
            console.log(event);
        }
        alert(event.origin + '\n' + event.data);
    });
    $(window).on('load', function() {
        if(window.parent.postMessage) {
            window.parent.postMessage('Hello ' + Page.id, '*');
        }
    });
    </script>
</head>
<body>
    <h1>iframe</h1>
    <p>It's the iframe.</p>
</body>
</html>

How to make the web page height to fit screen height

Try:

#content{ background-color:#F3F3F3; margin:auto;width:70%;height:77%;}
#footer{width:100%;background-color:#666666;height:22%;}

(77% and 22% roughly preserves the proportions of content and footer and should not cause scrolling)

Importing PNG files into Numpy?

Using a (very) commonly used package is prefered:

import matplotlib.pyplot as plt
im = plt.imread('image.png')

How to install a python library manually

You need to install it in a directory in your home folder, and somehow manipulate the PYTHONPATH so that directory is included.

The best and easiest is to use virtualenv. But that requires installation, causing a catch 22. :) But check if virtualenv is installed. If it is installed you can do this:

$ cd /tmp
$ virtualenv foo
$ cd foo
$ ./bin/python

Then you can just run the installation as usual, with /tmp/foo/python setup.py install. (Obviously you need to make the virtual environment in your a folder in your home directory, not in /tmp/foo. ;) )

If there is no virtualenv, you can install your own local Python. But that may not be allowed either. Then you can install the package in a local directory for packages:

$ wget http://pypi.python.org/packages/source/s/six/six-1.0b1.tar.gz#md5=cbfcc64af1f27162a6a6b5510e262c9d
$ tar xvf six-1.0b1.tar.gz 
$ cd six-1.0b1/
$ pythonX.X setup.py   install --install-dir=/tmp/frotz

Now you need to add /tmp/frotz/pythonX.X/site-packages to your PYTHONPATH, and you should be up and running!

How to display data from database into textbox, and update it

The answer is .IsPostBack as suggested by @Kundan Singh Chouhan. Just to add to it, move your code into a separate method from Page_Load

private void PopulateFields()
{
  using(SqlConnection con1 = new SqlConnection("Data Source=USER-PC;Initial Catalog=webservice_database;Integrated Security=True"))
  {
    DataTable dt = new DataTable();
    con1.Open();
    SqlDataReader myReader = null;  
    SqlCommand myCommand = new SqlCommand("select * from customer_registration where username='" + Session["username"] + "'", con1);

    myReader = myCommand.ExecuteReader();

    while (myReader.Read())
    {
        TextBoxPassword.Text = (myReader["password"].ToString());
        TextBoxRPassword.Text = (myReader["retypepassword"].ToString());
        DropDownListGender.SelectedItem.Text = (myReader["gender"].ToString());
        DropDownListMonth.Text = (myReader["birth"].ToString());
        DropDownListYear.Text = (myReader["birth"].ToString());
        TextBoxAddress.Text = (myReader["address"].ToString());
        TextBoxCity.Text = (myReader["city"].ToString());
        DropDownListCountry.SelectedItem.Text = (myReader["country"].ToString());
        TextBoxPostcode.Text = (myReader["postcode"].ToString());
        TextBoxEmail.Text = (myReader["email"].ToString());
        TextBoxCarno.Text = (myReader["carno"].ToString());
    }
    con1.Close();
  }//end using
}

Then call it in your Page_Load

protected void Page_Load(object sender, EventArgs e)
{

    if(!Page.IsPostBack)
    {
       PopulateFields();
    }
}

Cannot run Eclipse; JVM terminated. Exit code=13

This error occurred to me on ubuntu, having installed 32bit and 64bit java. Use

sudo update-alternatives --config java

to set the right version to use as default.

Android Google Maps API V2 Zoom to Current Location

After you instansiated the map object (from the fragment) add this -

private void centerMapOnMyLocation() {

    map.setMyLocationEnabled(true);

    location = map.getMyLocation();

    if (location != null) {
        myLocation = new LatLng(location.getLatitude(),
                location.getLongitude());
    }
    map.animateCamera(CameraUpdateFactory.newLatLngZoom(myLocation,
            Constants.MAP_ZOOM));
}

if you need any guidance just ask but it should be self explantory - just instansiate the myLocation object for a default one...

How do I prevent a parent's onclick event from firing when a child anchor is clicked?

If you do not intend to interact with the inner element/s in any case, then a CSS solution might be useful for you.

Just set the inner element/s to pointer-events: none

in your case:

.clickable > a {
    pointer-events: none;
}

or to target all inner elements generally:

.clickable * {
    pointer-events: none;
}

This easy hack saved me a lot of time while developing with ReactJS

Browser support could be found here: http://caniuse.com/#feat=pointer-events

Laravel assets url

Besides put all your assets in the public folder, you can use the HTML::image() Method, and only needs an argument which is the path to the image, relative on the public folder, as well:

{{ HTML::image('imgs/picture.jpg') }}

Which generates the follow HTML code:

<img src="http://localhost:8000/imgs/picture.jpg">

The link to other elements of HTML::image() Method: http://laravel-recipes.com/recipes/185/generating-an-html-image-element

Div not expanding even with content inside

div will not expand if it has other floating divs inside, so remove the float from the internal divs and it will expand.

Open a workbook using FileDialog and manipulate it in Excel VBA

Thankyou Frank.i got the idea. Here is the working code.

Option Explicit
Private Sub CommandButton1_Click()

  Dim directory As String, fileName As String, sheet As Worksheet, total As Integer
  Dim fd As Office.FileDialog

  Set fd = Application.FileDialog(msoFileDialogFilePicker)

  With fd
    .AllowMultiSelect = False
    .Title = "Please select the file."
    .Filters.Clear
    .Filters.Add "Excel 2003", "*.xls?"

    If .Show = True Then
      fileName = Dir(.SelectedItems(1))

    End If
  End With

  Application.ScreenUpdating = False
  Application.DisplayAlerts = False

  Workbooks.Open (fileName)

  For Each sheet In Workbooks(fileName).Worksheets
    total = Workbooks("import-sheets.xlsm").Worksheets.Count
    Workbooks(fileName).Worksheets(sheet.Name).Copy _
        after:=Workbooks("import-sheets.xlsm").Worksheets(total)
  Next sheet

  Workbooks(fileName).Close

  Application.ScreenUpdating = True
  Application.DisplayAlerts = True

End Sub

jQuery AJAX cross domain

You can control this via HTTP header by adding Access-Control-Allow-Origin. Setting it to * will accept cross-domain AJAX requests from any domain.

Using PHP it's really simple, just add the following line into the script that you want to have access outside from your domain:

header("Access-Control-Allow-Origin: *");

Don't forget to enable mod_headers module in httpd.conf.

Graphical user interface Tutorial in C

The two most usual choices are GTK+, which has documentation links here, and is mostly used with C; or Qt which has documentation here and is more used with C++.

I posted these two as you do not specify an operating system and these two are pretty cross-platform.

Groovy String to Date

Googling around for Groovy ways to "cast" a String to a Date, I came across this article: http://www.goodercode.com/wp/intercept-method-calls-groovy-type-conversion/

The author uses Groovy metaMethods to allow dynamically extending the behavior of any class' asType method. Here is the code from the website.

class Convert {
    private from
    private to

    private Convert(clazz) { from = clazz }
    static def from(clazz) {
        new Convert(clazz)
    }

    def to(clazz) {
        to = clazz
        return this
    }

    def using(closure) {
        def originalAsType = from.metaClass.getMetaMethod('asType', [] as Class[])
        from.metaClass.asType = { Class clazz ->
            if( clazz == to ) {
                closure.setProperty('value', delegate)
                closure(delegate)
            } else {
                originalAsType.doMethodInvoke(delegate, clazz)
            }
        }
    }
}

They provide a Convert class that wraps the Groovy complexity, making it trivial to add custom as-based type conversion from any type to any other:

Convert.from( String ).to( Date ).using { new java.text.SimpleDateFormat('MM-dd-yyyy').parse(value) }

def christmas = '12-25-2010' as Date

It's a convenient and powerful solution, but I wouldn't recommend it to someone who isn't familiar with the tradeoffs and pitfalls of tinkering with metaClasses.

bootstrap 4 responsive utilities visible / hidden xs sm lg not working

Screen Size Class

-

  1. Hidden on all .d-none

  2. Hidden only on xs .d-none .d-sm-block

  3. Hidden only on sm .d-sm-none .d-md-block

  4. Hidden only on md .d-md-none .d-lg-block

  5. Hidden only on lg .d-lg-none .d-xl-block

  6. Hidden only on xl .d-xl-none

  7. Visible on all .d-block

  8. Visible only on xs .d-block .d-sm-none

  9. Visible only on sm .d-none .d-sm-block .d-md-none

  10. Visible only on md .d-none .d-md-block .d-lg-none

  11. Visible only on lg .d-none .d-lg-block .d-xl-none

  12. Visible only on xl .d-none .d-xl-block

Refer this link http://getbootstrap.com/docs/4.0/utilities/display/#hiding-elements

4.5 link: https://getbootstrap.com/docs/4.5/utilities/display/#hiding-elements

Why is String immutable in Java?

I read this post Why String is Immutable or Final in Java and suppose that following may be the most important reason:

String is Immutable in Java because String objects are cached in String pool. Since cached String literals are shared between multiple clients there is always a risk, where one client's action would affect all another client.

What is the "proper" way to cast Hibernate Query.list() to List<Type>?

Just just using Transformers It did not work for me I was getting type cast exception.

sqlQuery.setResultTransformer(Transformers.aliasToBean(MYEngityName.class)) did notwork because I was getting Array of Object in the return list element not the fixed MYEngityName type of list element.

It worked for me when I make following changes When I have added sqlQuery.addScalar(-) each selected column and its type and for specific String type column we dont have to map its type. like addScalar("langCode");

And I have join MYEngityName with NextEnity we cant just select * in the Query it will give array of Object in the return list.

Below code sample :

session = ht.getSessionFactory().openSession();
                String sql = new StringBuffer("Select txnId,nft.mId,count,retryReason,langCode FROM  MYEngityName nft INNER JOIN NextEntity m on nft.mId  =  m.id where nft.txnId < ").append(lastTxnId)
                       .append(StringUtils.isNotBlank(regionalCountryOfService)? " And  m.countryOfService in ( "+ regionalCountryOfService +" )" :"")
                       .append(" order by nft.txnId desc").toString();
                SQLQuery sqlQuery = session.createSQLQuery(sql);
                sqlQuery.setResultTransformer(Transformers.aliasToBean(MYEngityName.class));
                sqlQuery.addScalar("txnId",Hibernate.LONG)
                        .addScalar("merchantId",Hibernate.INTEGER)
                        .addScalar("count",Hibernate.BYTE)
                        .addScalar("retryReason")
                        .addScalar("langCode");
                sqlQuery.setMaxResults(maxLimit);
                return sqlQuery.list();

It might help some one. in this way work for me.

JS: Failed to execute 'getComputedStyle' on 'Window': parameter is not of type 'Element'

In my case I was using ClassName.

getComputedStyle( document.getElementsByClassName(this_id)) //error

It will also work without 2nd argument " ".

Here is my complete running code :

function changeFontSize(target) {

  var minmax = document.getElementById("minmax");

  var computedStyle = window.getComputedStyle
        ? getComputedStyle(minmax) // Standards
        : minmax.currentStyle;     // Old IE

  var fontSize;

  if (computedStyle) { // This will be true on nearly all browsers
      fontSize = parseFloat(computedStyle && computedStyle.fontSize);

      if (target == "sizePlus") {
        if(fontSize<20){
        fontSize += 5;
        }

      } else if (target == "sizeMinus") {
        if(fontSize>15){
        fontSize -= 5;
        }
      }
      minmax.style.fontSize = fontSize + "px";
  }
}


onclick= "changeFontSize(this.id)"

How to maximize a plt.show() window using Python

My best effort so far, supporting different backends:

from platform import system
def plt_maximize():
    # See discussion: https://stackoverflow.com/questions/12439588/how-to-maximize-a-plt-show-window-using-python
    backend = plt.get_backend()
    cfm = plt.get_current_fig_manager()
    if backend == "wxAgg":
        cfm.frame.Maximize(True)
    elif backend == "TkAgg":
        if system() == "win32":
            cfm.window.state('zoomed')  # This is windows only
        else:
            cfm.resize(*cfm.window.maxsize())
    elif backend == 'QT4Agg':
        cfm.window.showMaximized()
    elif callable(getattr(cfm, "full_screen_toggle", None)):
        if not getattr(cfm, "flag_is_max", None):
            cfm.full_screen_toggle()
            cfm.flag_is_max = True
    else:
        raise RuntimeError("plt_maximize() is not implemented for current backend:", backend)

NGinx Default public www location?

On Mac OS X installing nginx with brew makes the default directory:

/usr/local/var/www

So:

root html

means

root /usr/local/var/www/html

There is no html directory so it would have to be created manually.

Undefined reference to `pow' and `floor'

Add -lm to your link options, since pow() and floor() are part of the math library:

gcc fib.c -o fibo -lm

How do implement a breadth first traversal?

This code which you have written, is not producing correct BFS traversal: (This is the code you claimed is BFS, but in fact this is DFS!)

//  search traversal
  public void breadth(TreeNode root){
      if (root == null)
          return;

      System.out.print(root.element + " ");
      breadth(root.left);
      breadth(root.right);
 }

asynchronous vs non-blocking

Synchronous is defined as happening at the same time.

Asynchronous is defined as not happening at the same time.

This is what causes the first confusion. Synchronous is actually what is known as parallel. While asynchronous is sequential, do this, then do that.

Now the whole problem is about modeling an asynchronous behaviour, because you've got some operation that needs the response of another before it can begin. Thus it's a coordination problem, how will you know that you can now start that operation?

The simplest solution is known as blocking.

Blocking is when you simply choose to wait for the other thing to be done and return you a response before moving on to the operation that needed it.

So if you need to put butter on toast, and thus you first need to toast the bred. The way you'd coordinate them is that you'd first toast the bred, then stare endlessly at the toaster until it pops the toast, and then you'd proceed to put butter on them.

It's the simplest solution, and works very well. There's no real reason not to use it, unless you happen to also have other things you need to be doing which don't require coordination with the operations. For example, doing some dishes. Why wait idle staring at the toaster constantly for the toast to pop, when you know it'll take a bit of time, and you could wash a whole dish while it finishes?

That's where two other solutions known respectively as non-blocking and asynchronous come into play.

Non-blocking is when you choose to do other unrelated things while you wait for the operation to be done. Checking back on the availability of the response as you see fit.

So instead of looking at the toaster for it to pop. You go and wash a whole dish. And then you peek at the toaster to see if the toasts have popped. If they havn't, you go wash another dish, checking back at the toaster between each dish. When you see the toasts have popped, you stop washing the dishes, and instead you take the toast and move on to putting butter on them.

Having to constantly check on the toasts can be annoying though, imagine the toaster is in another room. In between dishes you waste your time going to that other room to check on the toast.

Here comes asynchronous.

Asynchronous is when you choose to do other unrelated things while you wait for the operation to be done. Instead of checking on it though, you delegate the work of checking to something else, could be the operation itself or a watcher, and you have that thing notify and possibly interupt you when the response is availaible so you can proceed to the other operation that needed it.

Its a weird terminology. Doesn't make a whole lot of sense, since all these solutions are ways to create asynchronous coordination of dependent tasks. That's why I prefer to call it evented.

So for this one, you decide to upgrade your toaster so it beeps when the toasts are done. You happen to be constantly listening, even while you are doing dishes. On hearing the beep, you queue up in your memory that as soon as you are done washing your current dish, you'll stop and go put the butter on the toast. Or you could choose to interupt the washing of the current dish, and deal with the toast right away.

If you have trouble hearing the beep, you can have your partner watch the toaster for you, and come tell you when the toast is ready. Your partner can itself choose any of the above three strategies to coordinate its task of watching the toaster and telling you when they are ready.

On a final note, it's good to understand that while non-blocking and async (or what I prefer to call evented) do allow you to do other things while you wait, you don't have too. You can choose to constantly loop on checking the status of a non-blocking call, doing nothing else. That's often worse than blocking though (like looking at the toaster, then away, then back at it until its done), so a lot of non-blocking APIs allow you to transition into a blocking mode from it. For evented, you can just wait idle until you are notified. The downside in that case is that adding the notification was complex and potentially costly to begin with. You had to buy a new toaster with beep functionality, or convince your partner to watch it for you.

And one more thing, you need to realize the trade offs all three provide. One is not obviously better than the others. Think of my example. If your toaster is so fast, you won't have time to wash a dish, not even begin washing it, that's how fast your toaster is. Getting started on something else in that case is just a waste of time and effort. Blocking will do. Similarly, if washing a dish will take 10 times longer then the toasting. You have to ask yourself what's more important to get done? The toast might get cold and hard by that time, not worth it, blocking will also do. Or you should pick faster things to do while you wait. There's more obviously, but my answer is already pretty long, my point is you need to think about all that, and the complexities of implementing each to decide if its worth it, and if it'll actually improve your throughput or performance.

Edit:

Even though this is already long, I also want it to be complete, so I'll add two more points.

  1. There also commonly exists a fourth model known as multiplexed. This is when while you wait for one task, you start another, and while you wait for both, you start one more, and so on, until you've got many tasks all started and then, you wait idle, but on all of them. So as soon as any is done, you can proceed with handling its response, and then go back to waiting for the others. It's known as multiplexed, because while you wait, you need to check each task one after the other to see if they are done, ad vitam, until one is. It's a bit of an extension on top of normal non-blocking.

In our example it would be like starting the toaster, then the dishwasher, then the microwave, etc. And then waiting on any of them. Where you'd check the toaster to see if it's done, if not, you'd check the dishwasher, if not, the microwave, and around again.

  1. Even though I believe it to be a big mistake, synchronous is often used to mean one thing at a time. And asynchronous many things at a time. Thus you'll see synchronous blocking and non-blocking used to refer to blocking and non-blocking. And asynchronous blocking and non-blocking used to refer to multiplexed and evented.

I don't really understand how we got there. But when it comes to IO and Computation, synchronous and asynchronous often refer to what is better known as non-overlapped and overlapped. That is, asynchronous means that IO and Computation are overlapped, aka, happening concurrently. While synchronous means they are not, thus happening sequentially. For synchronous non-blocking, that would mean you don't start other IO or Computation, you just busy wait and simulate a blocking call. I wish people stopped misusing syncronous and asynchronous like that. So I'm not encouraging it.

How to include Javascript file in Asp.Net page

ScriptManager control can also be used to reference javascript files. One catch is that the ScriptManager control needs to be place inside the form tag. I myself prefer ScriptManager control and generally place it just above the closing form tag.

<asp:ScriptManager ID="sm" runat="server">
    <Scripts>
        <asp:ScriptReference Path="~/Scripts/yourscript.min.js" />
    </Scripts>
</asp:ScriptManager>

Upgrade to python 3.8 using conda

Now that the new anaconda individual edition 2020 distribution is out, the procedure that follows is working:

Update conda in your base env:

conda update conda

Create a new environment for Python 3.8, specifying anaconda for the full distribution specification, not just the minimal environment:

conda create -n py38 python=3.8 anaconda

Activate the new environment:

conda activate py38

python --version
Python 3.8.1

Number of packages installed: 303

Or you can do:

conda create -n py38 anaconda=2020.02 python=3.8

--> UPDATE: Finally, Anaconda3-2020.07 is out with core Python 3.8.3

You can download Anaconda with Python 3.8 from https://www.anaconda.com/products/individual

Free easy way to draw graphs and charts in C++?

Honestly, I was in the same boat as you. I've got a C++ Library that I wanted to connect to a graphing utility. I ended up using Boost Python and matplotlib. It was the best one that I could find.

As a side note: I was also wary of licensing. matplotlib and the boost libraries can be integrated into proprietary applications.

Here's an example of the code that I used:

#include <boost/python.hpp>
#include <pygtk/pygtk.h>
#include <gtkmm.h>

using namespace boost::python;
using namespace std;

// This is called in the idle loop.
bool update(object *axes, object *canvas) {
    static object random_integers = object(handle<>(PyImport_ImportModule("numpy.random"))).attr("random_integers");
    axes->attr("scatter")(random_integers(0,1000,1000), random_integers(0,1000,1000));
    axes->attr("set_xlim")(0,1000);
    axes->attr("set_ylim")(0,1000);
    canvas->attr("draw")();
    return true;
}

int main() {
    try {
        // Python startup code
        Py_Initialize();
        PyRun_SimpleString("import signal");
        PyRun_SimpleString("signal.signal(signal.SIGINT, signal.SIG_DFL)");

        // Normal Gtk startup code
        Gtk::Main kit(0,0);

        // Get the python Figure and FigureCanvas types.
        object Figure = object(handle<>(PyImport_ImportModule("matplotlib.figure"))).attr("Figure");
        object FigureCanvas = object(handle<>(PyImport_ImportModule("matplotlib.backends.backend_gtkagg"))).attr("FigureCanvasGTKAgg");

        // Instantiate a canvas
        object figure = Figure();
        object canvas = FigureCanvas(figure);
        object axes = figure.attr("add_subplot")(111);
        axes.attr("hold")(false);

        // Create our window.
        Gtk::Window window;
        window.set_title("Engineering Sample");
        window.set_default_size(1000, 600);

        // Grab the Gtk::DrawingArea from the canvas.
        Gtk::DrawingArea *plot = Glib::wrap(GTK_DRAWING_AREA(pygobject_get(canvas.ptr())));

        // Add the plot to the window.
        window.add(*plot);
        window.show_all();

        // On the idle loop, we'll call update(axes, canvas).
        Glib::signal_idle().connect(sigc::bind(&update, &axes, &canvas));

        // And start the Gtk event loop.
        Gtk::Main::run(window);

    } catch( error_already_set ) {
        PyErr_Print();
    }
}

Visual Studio: ContextSwitchDeadlock

I was getting this error and switched the queries to async (await (...).ToListAsync()). All good now.

How to maintain state after a page refresh in React.js?

I consider state to be for view only information and data that should persist beyond the view state is better stored as props. URL params are useful when you want to be able to link to a page or share the URL deep in to the app but otherwise clutter the address bar.

Take a look at Redux-Persist (if you're using redux) https://github.com/rt2zz/redux-persist

How to pass a value from Vue data to href?

Or you can do that with ES6 template literal:

<a :href="`/job/${r.id}`"

Always show vertical scrollbar in <select>

It will work in IE7. But here you need to fixed the size less than the number of option and not use overflow-y:scroll. In your example you have 2 option but you set size=10, which will not work.

Suppose your select has 10 option, then fixed size=9.

Here, in your code reference you used height:100px with size:2. I remove the height css, because its not necessary and change the size:5 and it works fine.

Here is your modified code from jsfiddle:

<select size="5" style="width:100px;">
 <option>1</option>
 <option>2</option>
 <option>3</option>
 <option>4</option>
 <option>5</option>
 <option>6</option>
</select>

this will generate a larger select box than size:2 create.In case of small size the select box will not display the scrollbar,you have to check with appropriate size quantity.Without scrollbar it will work if click on the upper and lower icons of scrollbar.I show both example in your fiddle with size:2 and size greater than 2(e.g: 3,5).

Here is your desired result. I think this will help you:

CSS

  .wrapper{
    border: 1px dashed red;
    height: 150px;
    overflow-x: hidden;
    overflow-y: scroll;
    width: 150px;
 }
 .wrapper .selection{
   width:150px;
   border:1px solid #ccc
 }

HTML

<div class="wrapper">
<select size="15" class="selection">
    <option>Item 1</option>
    <option>Item 2</option>
    <option>Item 3</option>
</select>
</div>

Semaphore vs. Monitors - what's the difference?

Semaphore :

Using a counter or flag to control access some shared resources in a concurrent system, implies use of Semaphore.

Example:

  1. A counter to allow only 50 Passengers to acquire the 50 seats (Shared resource) of any Theatre/Bus/Train/Fun ride/Classroom. And to allow a new Passenger only if someone vacates a seat.
  2. A binary flag indicating the free/occupied status of any Bathroom.
  3. Traffic lights are good example of flags. They control flow by regulating passage of vehicles on Roads (Shared resource)

Flags only reveal the current state of Resource, no count or any other information on the waiting or running objects on the resource.

Monitor :

A Monitor synchronizes access to an Object by communicating with threads interested in the object, asking them to acquire access or wait for some condition to become true.

Example:

  1. A Father may acts as a monitor for her daughter, allowing her to date only one guy at a time.
  2. A school teacher using baton to allow only one child to speak in the class.
  3. Lastly a technical one, transactions (via threads) on an Account object synchronized to maintain integrity.

Custom HTTP headers : naming conventions

Modifying, or more correctly, adding additional HTTP headers is a great code debugging tool if nothing else.

When a URL request returns a redirect or an image there is no html "page" to temporarily write the results of debug code to - at least not one that is visible in a browser.

One approach is to write the data to a local log file and view that file later. Another is to temporarily add HTTP headers reflecting the data and variables being debugged.

I regularly add extra HTTP headers like X-fubar-somevar: or X-testing-someresult: to test things out - and have found a lot of bugs that would have otherwise been very difficult to trace.

Querying Datatable with where condition

something like this ? :

DataTable dt = ...
DataView dv = new DataView(dt);
dv.RowFilter = "(EmpName != 'abc' or EmpName != 'xyz') and (EmpID = 5)"

Is it what you are searching for?

Remove a HTML tag but keep the innerHtml

The simplest way to remove inner html elements and return only text would the JQuery .text() function.

Example:

var text = $('<p>A nice house was found in <b>Toronto</b></p>');

alert( text.html() );
//Outputs A nice house was found in <b>Toronto</b>

alert( text.text() );
////Outputs A nice house was found in Toronto

jsFiddle Demo

HTML if image is not found

I added a parent div around the image and used the following onerror event handler to hide the original image because in IE there was still an ugly image-not-found image shown after using the alt attribute:

<div style=" width:300px; height:150px; float:left; margin-left:5px; margin-top:50px;">
        <img src='@Url.Content("~/Images/Logo-Left.png")' onerror="this.parentElement.innerHTML = '';" />
</div>

Setting the default value of a DateTime Property to DateTime.Now inside the System.ComponentModel Default Value Attrbute

Add below to the DateTime property

[DatabaseGenerated(DatabaseGeneratedOption.Computed)]

How to find the files that are created in the last hour in unix

Check out this link for more details.

To find files which are created in last one hour in current directory, you can use -amin

find . -amin -60 -type f

This will find files which are created with in last 1 hour.

Create Git branch with current changes

Follow these steps:

  1. Create a new branch:

    git branch newfeature
    
  2. Checkout new branch: (this will not reset your work.)

    git checkout newfeature
    
  3. Now commit your work on this new branch:

    git commit -s
    

Using above steps will keep your original branch clean and you dont have to do any 'git reset --hard'.

Converting string to tuple without splitting characters

See:

'Quattro TT'

is a string.

Since string is a list of characters, this is the same as

['Q', 'u', 'a', 't', 't', 'r', 'o', ' ', 'T', 'T']

Now...

['Quattro TT']

is a list with a string in the first position.

Also...

a = 'Quattro TT'

list(a)

is a string converted into a list.

Again, since string is a list of characters, there is not much change.

Another information...

tuple(something)

This convert something into tuple.

Understanding all of this, I think you can conclude that nothing fails.

How do I spool to a CSV formatted file using SQLPLUS?

Use vi or vim to write the sql, use colsep with a control-A (in vi and vim precede the ctrl-A with a ctrl-v). Be sure to set the linesize and pagesize to something rational and turn on trimspool and trimout.

spool it off to a file. Then...

sed -e 's/,/;/g' -e 's/ *{ctrl-a} */,/g'  {spooled file}  > output.csv

That sed thing can be turned into a script. The " *" before and after the ctrl-A squeezes out all the useless spaces. Isn't it great that they bothered to enable html output from sqlplus but NOT native csv?????

I do it this way because it handles commas in the data. I turns them to semi-colons.

What does the star operator mean, in a function call?

I find this particularly useful for when you want to 'store' a function call.

For example, suppose I have some unit tests for a function 'add':

def add(a, b): return a + b
tests = { (1,4):5, (0, 0):0, (-1, 3):3 }
for test, result in tests.items():
    print 'test: adding', test, '==', result, '---', add(*test) == result

There is no other way to call add, other than manually doing something like add(test[0], test[1]), which is ugly. Also, if there are a variable number of variables, the code could get pretty ugly with all the if-statements you would need.

Another place this is useful is for defining Factory objects (objects that create objects for you). Suppose you have some class Factory, that makes Car objects and returns them. You could make it so that myFactory.make_car('red', 'bmw', '335ix') creates Car('red', 'bmw', '335ix'), then returns it.

def make_car(*args):
    return Car(*args)

This is also useful when you want to call a superclass' constructor.

Minimum 6 characters regex expression

If I understand correctly, you need a regex statement that checks for at least 6 characters (letters & numbers)?

/[0-9a-zA-Z]{6,}/

Recommendations of Python REST (web services) framework?

I am not an expert on the python world but I have been using django which is an excellent web framework and can be used to create a restful framework.

How to print bytes in hexadecimal using System.out.println?

for (int j=0; j<test.length; j++) {
   System.out.format("%02X ", test[j]);
}
System.out.println();

Linux Process States

Yes, tasks waiting for IO are blocked, and other tasks get executed. Selecting the next task is done by the Linux scheduler.

Play multiple CSS animations at the same time

You cannot play two animations since the attribute can be defined only once. Rather why don't you include the second animation in the first and adjust the keyframes to get the timing right?

_x000D_
_x000D_
.image {_x000D_
    position: absolute;_x000D_
    top: 50%;_x000D_
    left: 50%;_x000D_
    width: 120px;_x000D_
    height: 120px;_x000D_
    margin:-60px 0 0 -60px;_x000D_
    -webkit-animation:spin-scale 4s linear infinite;_x000D_
}_x000D_
_x000D_
@-webkit-keyframes spin-scale { _x000D_
    50%{_x000D_
        transform: rotate(360deg) scale(2);_x000D_
    }_x000D_
    100% { _x000D_
        transform: rotate(720deg) scale(1);_x000D_
    } _x000D_
}
_x000D_
<img class="image" src="http://makeameme.org/media/templates/120/grumpy_cat.jpg" alt="" width="120" height="120">
_x000D_
_x000D_
_x000D_

How to generate an openSSL key using a passphrase from the command line?

If you don't use a passphrase, then the private key is not encrypted with any symmetric cipher - it is output completely unprotected.

You can generate a keypair, supplying the password on the command-line using an invocation like (in this case, the password is foobar):

openssl genrsa -aes128 -passout pass:foobar 3072

However, note that this passphrase could be grabbed by any other process running on the machine at the time, since command-line arguments are generally visible to all processes.

A better alternative is to write the passphrase into a temporary file that is protected with file permissions, and specify that:

openssl genrsa -aes128 -passout file:passphrase.txt 3072

Or supply the passphrase on standard input:

openssl genrsa -aes128 -passout stdin 3072

You can also used a named pipe with the file: option, or a file descriptor.


To then obtain the matching public key, you need to use openssl rsa, supplying the same passphrase with the -passin parameter as was used to encrypt the private key:

openssl rsa -passin file:passphrase.txt -pubout

(This expects the encrypted private key on standard input - you can instead read it from a file using -in <file>).


Example of creating a 3072-bit private and public key pair in files, with the private key pair encrypted with password foobar:

openssl genrsa -aes128 -passout pass:foobar -out privkey.pem 3072
openssl rsa -in privkey.pem -passin pass:foobar -pubout -out privkey.pub

How to ignore a particular directory or file for tslint?

Currently using Visual Studio Code and the command to disable tslint is

/* tslint:disable */

Something to note. The disable above disables ALL tslint rules on that page. If you want to disable a specific rule you can specify one/multiple rules.

/* tslint:disable comment-format */
/* tslint:disable:rule1 rule2 rule3 etc.. */

Or enable a rule

/* tslint:enable comment-format */

More in depth on TSLint rule flags

How do I force a favicon refresh?

This answer has not been given yet so I thought I'd post it. I looked all around the web, and didn't find a good answer for testing favicons in local development.

In current version of chrome (on OSX) if you do the following you will get an instant favicon refresh:

  1. Hover over tab
  2. Right Click
  3. Select reload
  4. Your favicon should now be refreshed

This is the easiest way I've found to refresh the favicon locally.

Why shouldn't I use PyPy over CPython if PyPy is 6.3 times faster?

Supported Python Versions

To cite the Zen of Python:

Readability counts.

For example, Python 3.7 introduced dataclasses and Python 3.8 introduced fstring =.

There might be other features in Python 3.7 and Python 3.8 which are more important to you. The point is that PyPy does not support Python 3.7 or Python 3.8 at the moment.

Shameless self-advertisement: Killer Features by Python version - if you want to know more things you miss by using older Python versions

How do you run CMD.exe under the Local System Account?

  1. Download psexec.exe from Sysinternals.
  2. Place it in your C:\ drive.
  3. Logon as a standard or admin user and use the following command: cd \. This places you in the root directory of your drive, where psexec is located.
  4. Use the following command: psexec -i -s cmd.exe where -i is for interactive and -s is for system account.
  5. When the command completes, a cmd shell will be launched. Type whoami; it will say 'system"
  6. Open taskmanager. Kill explorer.exe.
  7. From an elevated command shell type start explorer.exe.
  8. When explorer is launched notice the name "system" in start menu bar. Now you can delete some files in system32 directory which as admin you can't delete or as admin you would have to try hard to change permissions to delete those files.

Users who try to rename or deleate System files in any protected directory of windows should know that all windows files are protected by DACLS while renaming a file you have to change the owner and replace TrustedInstaller which owns the file and make any user like a user who belongs to administrator group as owner of file then try to rename it after changing the permission, it will work and while you are running windows explorer with kernel privilages you are somewhat limited in terms of Network access for security reasons and it is still a research topic for me to get access back

How to get a unique computer identifier in Java (like disk ID or motherboard ID)?

Not Knowing all of your requirements. For example, are you trying to uniquely identify a computer from all of the computers in the world, or are you just trying to uniquely identify a computer from a set of users of your application. Also, can you create files on the system?

If you are able to create a file. You could create a file and use the creation time of the file as your unique id. If you create it in user space then it would uniquely identify a user of your application on a particular machine. If you created it somewhere global then it could uniquely identify the machine.

Again, as most things, How fast is fast enough.. or in this case, how unique is unique enough.

simple Jquery hover enlarge

If you have more than 1 image on the page that you like to enlarge, name the id's for instance "content1", "content2", "content3", etc. Then extend the script with this, like so:

$(document).ready(function() {
    $("[id^=content]").hover(function() {
        $(this).addClass('transition');
    }, function() {
        $(this).removeClass('transition');
    });
});

Edit: Change the "#content" CSS to: img[id^=content] to remain having the transition effects.

type object 'datetime.datetime' has no attribute 'datetime'

If you have used:

from datetime import datetime

Then simply write the code as:

date = datetime(int(year), int(month), 1)

But if you have used:

import datetime

then only you can write:

date = datetime.datetime(int(2005), int(5), 1)

Converting int to string in C

itoa() function is not defined in ANSI-C, so not implemented by default for some platforms (Reference Link).

s(n)printf() functions are easiest replacement of itoa(). However itoa (integer to ascii) function can be used as a better overall solution of integer to ascii conversion problem.

itoa() is also better than s(n)printf() as performance depending on the implementation. A reduced itoa (support only 10 radix) implementation as an example: Reference Link

Another complete itoa() implementation is below (Reference Link):

#include <stdbool.h> 
#include <string.h>

// A utility function to reverse a string 
char *reverse(char *str)
{
  char *p1, *p2;

  if (! str || ! *str)
        return str;
  for (p1 = str, p2 = str + strlen(str) - 1; p2 > p1; ++p1, --p2)
  {
        *p1 ^= *p2;
        *p2 ^= *p1;
        *p1 ^= *p2;
  }
  return str;
}
// Implementation of itoa() 
char* itoa(int num, char* str, int base) 
{ 
    int i = 0; 
    bool isNegative = false; 
  
    /* Handle 0 explicitely, otherwise empty string is printed for 0 */
    if (num == 0) 
    { 
        str[i++] = '0'; 
        str[i] = '\0'; 
        return str; 
    } 
  
    // In standard itoa(), negative numbers are handled only with  
    // base 10. Otherwise numbers are considered unsigned. 
    if (num < 0 && base == 10) 
    { 
        isNegative = true; 
        num = -num; 
    } 
  
    // Process individual digits 
    while (num != 0) 
    { 
        int rem = num % base; 
        str[i++] = (rem > 9)? (rem-10) + 'a' : rem + '0'; 
        num = num/base; 
    } 
  
    // If number is negative, append '-' 
    if (isNegative) 
        str[i++] = '-'; 
  
    str[i] = '\0'; // Append string terminator 
  
    // Reverse the string 
    reverse(str); 
  
    return str; 
} 

Another complete itoa() implementatiton: Reference Link

An itoa() usage example below (Reference Link):

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
int main()
{
    int a=54325;
    char buffer[20];
    itoa(a,buffer,2);   // here 2 means binary
    printf("Binary value = %s\n", buffer);
 
    itoa(a,buffer,10);   // here 10 means decimal
    printf("Decimal value = %s\n", buffer);
 
    itoa(a,buffer,16);   // here 16 means Hexadecimal
    printf("Hexadecimal value = %s\n", buffer);
    return 0;
}

Responsive Google Map?

in the iframe tag, you can easily add width='100%' instead of the preset value giving to you by the map

like this:

 <iframe src="https://www.google.com/maps/embed?anyLocation" width="100%" height="400" frameborder="0" style="border:0;" allowfullscreen=""></iframe>

what is the difference between json and xml

They're two different ways of representing data, but they're pretty dissimilar. The wikipedia pages for JSON and XML give some examples of each, and there's a comparison paragraph

How do I read a response from Python Requests?

Requests doesn't have an equivalent to Urlib2's read().

>>> import requests
>>> response = requests.get("http://www.google.com")
>>> print response.content
'<!doctype html><html itemscope="" itemtype="http://schema.org/WebPage"><head>....'
>>> print response.content == response.text
True

It looks like the POST request you are making is returning no content. Which is often the case with a POST request. Perhaps it set a cookie? The status code is telling you that the POST succeeded after all.

Edit for Python 3:

Python now handles data types differently. response.content returns a sequence of bytes (integers that represent ASCII) while response.text is a string (sequence of chars).

Thus,

>>> print response.content == response.text
False

>>> print str(response.content) == response.text
True

Convert a matrix to a 1 dimensional array

If you instead had a data.frame (df) that had multiple columns and you want to vectorize you can do

as.matrix(df, ncol=1)

How to pass all arguments passed to my bash script to a function of mine?

abc "$@" is generally the correct answer. But I was trying to pass a parameter through to an su command, and no amount of quoting could stop the error su: unrecognized option '--myoption'. What actually worked for me was passing all the arguments as a single string :

abc "$*"

My exact case (I'm sure someone else needs this) was in my .bashrc

# run all aws commands as Jenkins user
aws ()
{
    sudo su jenkins -c "aws $*"
}

MetadataException when using Entity Framework Entity Connection

I moved my Database First DataModel to a different project midway through development. Poor planning (or lack there of) on my part.

Initially I had a solution with one project. Then I added another project to the solution and recreated my Database First DataModel from the Sql Server Dataase.

To fix the problem - MetadataException when using Entity Framework Entity Connection. I copied my the ConnectionString from the new Project Web.Config to the original project Web.Config. However, this occurred after I updated my all the references in the original project to new DataModel project.

Wordpress - Images not showing up in the Media Library

Well, Seems like there was a bug when creating custom post types in the function.php file of the theme... which bugged that.

How do I get some variable from another class in Java?

Your example is perfect: the field is private and it has a getter. This is the normal way to access a field. If you need a direct access to an object field, use reflection. Using reflection to get a field's value is a hack and should be used in extreme cases such as using a library whose code you cannot change.

Cannot execute RUN mkdir in a Dockerfile

The problem is that /var/www doesn't exist either, and mkdir isn't recursive by default -- it expects the immediate parent directory to exist.

Use:

mkdir -p /var/www/app

...or install a package that creates a /var/www prior to reaching this point in your Dockerfile.

Using Auto Layout in UITableView for dynamic cell layouts & variable row heights

In my case, the padding was because of the sectionHeader and sectionFooter heights, where storyboard allowed me to change it to minimum 1. So in viewDidLoad method:

tableView.sectionHeaderHeight = 0
tableView.sectionFooterHeight = 0

Difference between clustered and nonclustered index

faster to read than non cluster as data is physically storted in index order we can create only one per table.(cluster index)

quicker for insert and update operation than a cluster index. we can create n number of non cluster index.

Mocking HttpClient in unit tests

To add my 2 cents. To mock specific http request methods either Get or Post. This worked for me.

mockHttpMessageHandler.Protected().Setup<Task<HttpResponseMessage>>("SendAsync", ItExpr.Is<HttpRequestMessage>(a => a.Method == HttpMethod.Get), ItExpr.IsAny<CancellationToken>())
                                                .Returns(Task.FromResult(new HttpResponseMessage()
                                                {
                                                    StatusCode = HttpStatusCode.OK,
                                                    Content = new StringContent(""),
                                                })).Verifiable();

What does `set -x` do?

set -x enables a mode of the shell where all executed commands are printed to the terminal. In your case it's clearly used for debugging, which is a typical use case for set -x: printing every command as it is executed may help you to visualize the control flow of the script if it is not functioning as expected.

set +x disables it.

Setting initial values on load with Select2 with Ajax

I`ve added

initSelection: function (element, callback) {

      callback({ id: 1, text: 'Text' });
}

BUT also

.select2('val', []);

at the end.

This solved my issue.

Is there Unicode glyph Symbol to represent "Search"

Use the ? symbol (encoded as &#9906; or &#x26B2;), and rotate it to achieve the desired effect:

<div style="-webkit-transform: rotate(45deg); 
               -moz-transform: rotate(45deg); 
                 -o-transform: rotate(45deg);
                    transform: rotate(45deg);">
    &#9906;
</div>

It rotates a symbol :)

What is the facade design pattern?

A design pattern is a general reusable solution to a commonly occurring problem within a given context in software design.

The Facade design pattern is a structural pattern as it defines a manner for creating relationships between classes or entities. The facade design pattern is used to define a simplified interface to a more complex subsystem.

The facade pattern is ideal when working with a large number of interdependent classes, or with classes that require the use of multiple methods, particularly when they are complicated to use or difficult to understand. The facade class is a "wrapper" that contains a set of members that are easily understood and simple to use. These members access the subsystem on behalf of the facade user, hiding the implementation details.

The facade design pattern is particularly useful when wrapping subsystems that are poorly designed but cannot be refactored because the source code is unavailable or the existing interface is widely used. Sometimes you may decide to implement more than one facade to provide subsets of functionality for different purposes.

One example use of the facade pattern is for integrating a web site with a business application. The existing software may include large amounts of business logic that must be accessed in a particular manner. The web site may require only limited access to this business logic. For example, the web site may need to show whether an item for sale has reached a limited level of stock. The IsLowStock method of the facade class could return a Boolean value to indicate this. Behind the scenes, this method could be hiding the complexities of processing the current physical stock, incoming stock, allocated items and the low stock level for each item.

How to set HTTP headers (for cache-control)?

OWASP recommends the following,

Whenever possible ensure the cache-control HTTP header is set with no-cache, no-store, must-revalidate, private; and that the pragma HTTP header is set with no-cache.

<IfModule mod_headers.c>
    Header set Cache-Control "private, no-cache, no-store, proxy-revalidate, no-transform"
    Header set Pragma "no-cache"
</IfModule>

Difference between break and continue in PHP?

break used to get out from the loop statement, but continue just stop script on specific condition and then continue looping statement until reach the end..

for($i=0; $i<10; $i++){
    if($i == 5){
        echo "It reach five<br>";
        continue;
    }
    echo $i . "<br>";
}

echo "<hr>";

for($i=0; $i<10; $i++){
    if($i == 5){
         echo "It reach end<br>";
         break;
    }
    echo $i . "<br>";
}

Hope it can help u;

SQL update fields of one table from fields of another one

Try Following

Update A a, B b, SET a.column1=b.column1 where b.id=1

EDITED:- Update more than one column

Update A a, B b, SET a.column1=b.column1, a.column2=b.column2 where b.id=1

run program in Python shell

Use execfile for Python 2:

>>> execfile('C:\\test.py')

Use exec for Python 3

>>> exec(open("C:\\test.py").read())

What is the use of rt.jar file in java?

rt.jar contains all of the compiled class files for the base Java Runtime environment. You should not be messing with this jar file.

For MacOS it is called classes.jar and located under /System/Library/Frameworks/<java_version>/Classes . Same not messing with it rule applies there as well :).

http://javahowto.blogspot.com/2006/05/what-does-rtjar-stand-for-in.html

Programmatically close aspx page from code behind

UPDATE: I have taken all of your input and came up with the following solution:

In code behind:

protected void Page_Load(object sender, EventArgs e)    
{
    Page.ClientScript.RegisterOnSubmitStatement(typeof(Page), "closePage", "window.onunload = CloseWindow();");
}

In aspx page:

function CloseWindow() {
    window.close();
}

How to move (and overwrite) all files from one directory to another?

If you simply need to answer "y" to all the overwrite prompts, try this:

y | mv srcdir/* targetdir/

What is the difference between compileSdkVersion and targetSdkVersion?

I see a lot of differences about compiledSdkVersion in previous answers, so I'll try to clarify a bit here, following android's web page.

A - What Android says

According https://developer.android.com/guide/topics/manifest/uses-sdk-element.html:

Selecting a platform version and API Level When you are developing your application, you will need to choose the platform version against which you will compile the application. In general, you should compile your application against the lowest possible version of the platform that your application can support.

So, this would be the right order according to Android:

compiledSdkVersion = minSdkVersion <= targetSdkVersion

B - What others also say

Some people prefer to always use the highest compiledSkdVersion available. It is because they will rely on code hints to check if they are using newer API features than minSdkVersion, thus either changing the code to not use them or checking the user API version at runtime to conditionally use them with fallbacks for older API versions.

Hints about deprecated uses would also appear in code, letting you know that something is deprecated in newer API levels, so you can react accordingly if you wish.

So, this would be the right order according to others:

minSdkVersion <= targetSdkVersion <= compiledSdkVersion (highest possible)

What to do?

It depends on you and your app.

If you plan to offer different API features according to the API level of the user at runtime, use option B. You'll get hints about the features you use while coding. Just make sure you never use newer API features than minSdkVersion without checking user API level at runtime, otherwise your app will crash. This approach also has the benefit of learning what's new and what's old while coding.

If you already know what's new or old and you are developing a one time app that for sure will never be updated, or you are sure you are not going to offer new API features conditionally, then use option A. You won't get bothered with deprecated hints and you will never be able to use newer API features even if you're tempted to do it.

How to make a gap between two DIV within the same column

You can make use of the first-child selector

<div class="sidebar">
    <div class="box">
        <p> 
            Text is here
         </p>
     </div>
    <div class="box">
        <p> 
            Text is here
         </p>
     </div>
</div>

and in CSS

.box {
    padding: 10px;
    text-align: justify;
    margin-top: 20px;
}
.box:first-child {
    margin-top: none;
}

Example: http://jsbin.com/ozarot/edit#javascript,html,live

How can I see what I am about to push with git?

If you are using Mac OS X, I would recommend you get Tower, it's a wonderful program that has made dealing with Git a pleasure for me. I now longer have to remember terminal commands and it offers a great GUI to view, track and solve differences in files.

And no, I'm not affiliated with them, I just use their software and really like it.

http://www.git-tower.com/

Artisan, creating tables in database

in laravel 5 first we need to create migration and then run the migration

Step 1.

php artisan make:migration create_users_table --create=users

Step 2.

php artisan migrate

Google Play Services GCM 9.2.0 asks to "update" back to 9.0.0

Add this line at the bottom of the gradle.

apply plugin: 'com.google.gms.google-services'

because it the top it does not work.I was facing similar problem.

Is there an easy way to add a border to the top and bottom of an Android View?

So I wanted to do something slightly different: a border on the bottom ONLY, to simulate a ListView divider. I modified Piet Delport's answer and got this:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
   <item>
      <shape 
        android:shape="rectangle">
            <solid android:color="@color/background_trans_light" />    

        </shape>
   </item>

    <!-- this mess is what we have to do to get a bottom border only. -->
   <item android:top="-2dp"
         android:left="-2dp"
         android:right="-2dp"
         android:bottom="1px"> 
      <shape 
        android:shape="rectangle">    
            <stroke android:width="1dp" android:color="@color/background_trans_mid" />
            <solid android:color="@null" />
        </shape>
   </item>

</layer-list>

Note using px instead of dp to get exactly 1 pixel divider (some phone DPIs will make a 1dp line disappear).

Is it a bad practice to use break in a for loop?

I did some analysis on the codebase I'm currently working on (40,000 lines of JavaScript).

I found only 22 break statements, of those:

  • 19 were used inside switch statements (we only have 3 switch statements in total!).
  • 2 were used inside for loops - a code that I immediately classified as to be refactored into separate functions and replaced with return statement.
  • As for the final break inside while loop... I ran git blame to see who wrote this crap!

So according to my statistics: If break is used outside of switch, it is a code smell.

I also searched for continue statements. Found none.

Printing prime numbers from 1 through 100

To find whether no. is prime or not C++:

#include<iostream>
#include<cmath>

using namespace std;
int main(){

int n, counter=0;

cout <<"Enter a number to check whether it is prime or not \n";
cin>>n;

  for(int i=2; i<=n-1;i++) {
    if (n%i==0) {
      cout<<n<<" is NOT a prime number \n";
      break;
    }
    counter++;
                }
    //cout<<"Value n is "<<n<<endl;
    //cout << "number of times counter run is "<<counter << endl;
    if (counter == n-2)
      cout << n<< " is prime \n";
   return 0;
}

XPath OR operator for different nodes

All title nodes with zipcode or book node as parent:

Version 1:

//title[parent::zipcode|parent::book]

Version 2:

//bookstore/book/title|//bookstore/city/zipcode/title

Version 3: (results are sorted based on source data rather than the order of book then zipcode)

//title[../../../*[book or magazine] or ../../../../*[city/zipcode]]

or - used within true/false - a Boolean operator in xpath

| - a Union operator in xpath that appends the query to the right of the operator to the result set from the left query.

How do servlets work? Instantiation, sessions, shared variables and multithreading

No. Servlets are not Thread safe

This is allows accessing more than one threads at a time

if u want to make it Servlet as Thread safe ., U can go for

Implement SingleThreadInterface(i) which is a blank Interface there is no

methods

or we can go for synchronize methods

we can make whole service method as synchronized by using synchronized

keyword in front of method

Example::

public Synchronized class service(ServletRequest request,ServletResponse response)throws ServletException,IOException

or we can the put block of the code in the Synchronized block

Example::

Synchronized(Object)

{

----Instructions-----

}

I feel that Synchronized block is better than making the whole method

Synchronized

An internal error occurred during: "Updating Maven Project". Unsupported IClasspathEntry kind=4

I had to do it slightly different to work for me:

  1. rightclick project, remove maven nature (or in newer eclipse, "Maven->Disable Maven Nature")
  2. mvn eclipse:clean (with project open in eclipse/STS)
  3. delete the project in eclipse (but do not delete the sources)
  4. Import existing Maven project

Creating temporary files in bash

Is there any advantage in creating a temporary file in a more careful way

The temporary files are usually created in the temporary directory (such as /tmp) where all other users and processes has read and write access (any other script can create the new files there). Therefore the script should be careful about creating the files such as using with the right permissions (e.g. read only for the owner, see: help umask) and filename should be be not easily guessed (ideally random). Otherwise if the filenames aren't unique, it can create conflict with the same script ran multiple times (e.g. race condition) or some attacker could either hijack some sensitive information (e.g. when permissions are too open and filename is easy to guess) or create/replacing the file with their own version of the code (like replacing the commands or SQL queries depending on what is being stored).


You could use the following approach to create the temporary directory:

TMPDIR=".${0##*/}-$$" && mkdir -v "$TMPDIR"

or temporary file:

TMPFILE=".${0##*/}-$$" && touch "$TMPFILE"

However it is still predictable and not considered safe.

As per man mktemp, we can read:

Traditionally, many shell scripts take the name of the program with the pid as a suffix and use that as a temporary file name. This kind of naming scheme is predictable and the race condition it creates is easy for an attacker to win.

So to be safe, it is recommended to use mktemp command to create unique temporary file or directory (-d).

What is the HTML5 equivalent to the align attribute in table cells?

you can use this code as replacement for table align

table 
{
    margin:auto;
}

TempData keep() vs peek()

don't they both keep a value for another request?

Yes they do, but when the first one is void, the second one returns and object:

public void Keep(string key)
{
    _retainedKeys.Add(key); // just adds the key to the collection for retention
}

public object Peek(string key)
{
    object value;
    _data.TryGetValue(key, out value);
    return value; // returns an object without marking it for deletion
}

How do I check if a variable exists?

Using try/except is the best way to test for a variable's existence. But there's almost certainly a better way of doing whatever it is you're doing than setting/testing global variables.

For example, if you want to initialize a module-level variable the first time you call some function, you're better off with code something like this:

my_variable = None

def InitMyVariable():
  global my_variable
  if my_variable is None:
    my_variable = ...

Merge, update, and pull Git branches without using checkouts

I wrote a shell function for a similar use case I encounter daily on projects. This is basically a shortcut for keeping local branches up to date with a common branch like develop before opening a PR, etc.

Posting this even though you don't want to use checkout, in case others don't mind that constraint.

glmh ("git pull and merge here") will automatically checkout branchB, pull the latest, re-checkout branchA, and merge branchB.

Doesn't address the need to keep a local copy of branchA, but could easily be modified to do so by adding a step before checking out branchB. Something like...

git branch ${branchA}-no-branchB ${branchA}

For simple fast-forward merges, this skips to the commit message prompt.

For non fast-forward merges, this places your branch in the conflict resolution state (you likely need to intervene).

To setup, add to .bashrc or .zshrc, etc:

glmh() {
    branchB=$1
    [ $# -eq 0 ] && { branchB="develop" }
    branchA="$(git branch | grep '*' | sed 's/* //g')"
    git checkout ${branchB} && git pull
    git checkout ${branchA} && git merge ${branchB} 
}

Usage:

# No argument given, will assume "develop"
> glmh

# Pass an argument to pull and merge a specific branch
> glmh your-other-branch

Note: This is not robust enough to hand-off of args beyond branch name to git merge

how to check if List<T> element contains an item with a Particular Property Value

This is pretty easy to do using LINQ:

var match = pricePublicList.FirstOrDefault(p => p.Size == 200);
if (match == null)
{
    // Element doesn't exist
}

Rails where condition using NOT NIL

With Rails 4 it's easy:

 Foo.includes(:bar).where.not(bars: {id: nil})

See also: http://guides.rubyonrails.org/active_record_querying.html#not-conditions

vue.js 2 how to watch store values from vuex

I think the asker wants to use watch with Vuex.

this.$store.watch(
      (state)=>{
        return this.$store.getters.your_getter
      },
      (val)=>{
       //something changed do something

      },
      {
        deep:true
      }
      );

List of tables, db schema, dump etc using the Python sqlite3 API

The FASTEST way of doing this in python is using Pandas (version 0.16 and up).

Dump one table:

db = sqlite3.connect('database.db')
table = pd.read_sql_query("SELECT * from table_name", db)
table.to_csv(table_name + '.csv', index_label='index')

Dump all tables:

import sqlite3
import pandas as pd


def to_csv():
    db = sqlite3.connect('database.db')
    cursor = db.cursor()
    cursor.execute("SELECT name FROM sqlite_master WHERE type='table';")
    tables = cursor.fetchall()
    for table_name in tables:
        table_name = table_name[0]
        table = pd.read_sql_query("SELECT * from %s" % table_name, db)
        table.to_csv(table_name + '.csv', index_label='index')
    cursor.close()
    db.close()

In MS DOS copying several files to one file

copy /b file1 + file2 + file3 newfile

Each source file must be added to the copy command with a +, and the last filename listed will be where the concatenated data is copied to.

How to append contents of multiple files into one file

If all your files are in single directory you can simply do

cat * > 0.txt

Files 1.txt,2.txt, .. will go into 0.txt

Authenticate with GitHub using a token

For those coming from GitLab what's worked for me:

Step 1.

add remote

git remote add origin https://<access-token-name>:<access-token>@gitlab.com/path/to/project.git

Step 2.

pull once

https://<access-token-name>:<access-token>@gitlab.com/path/to/project.git

now you are able to read/write to/from repository

Is there any difference between a GUID and a UUID?

Not really. GUID is more Microsoft-centric whereas UUID is used more widely (e.g., as in the urn:uuid: URN scheme, and in CORBA).

CSS selector (id contains part of text)

The only selector I see is a[id$="name"] (all links with id finishing by "name") but it's not as restrictive as it should.

How to get number of video views with YouTube API?

Here an example that I used in my TubeCount app.

I also use the fields parameter to filter the JSON result, so only the fields that I need are returned.

var fields = "fields=openSearch:totalResults,entry(title,media:group(yt:videoid),media:group(yt:duration),media:group(media:description),media:group(media:thumbnail[@yt:name='default'](@url)),yt:statistics,yt:rating,published,gd:comments(gd:feedLink(@countHint)))";

var channel = "wiibart";

$.ajax({
    url: "http://gdata.youtube.com/feeds/api/users/"+channel+"/uploads?"+fields+"&v=2&alt=json",
    success: function(data){

        var len = data.feed.entry.length;

        for(var k =0; k<len; k++){
            var yt = data.feed.entry[k];
            v.count = Number(yt.yt$statistics != undefined && yt.yt$statistics.viewCount != undefined ? yt.yt$statistics.viewCount : 0);
        }
    }
});

Syntax for async arrow function

My async function

const getAllRedis = async (key) => {
  let obj = [];

  await client.hgetall(key, (err, object) => {
    console.log(object);
    _.map(object, (ob)=>{
      obj.push(JSON.parse(ob));
    })
    return obj;
    // res.send(obj);
});
}

How to print variables in Perl

print "Number of lines: $nids\n";
print "Content: $ids\n";

How did Perl complain? print $ids should work, though you probably want a newline at the end, either explicitly with print as above or implicitly by using say or -l/$\.

If you want to interpolate a variable in a string and have something immediately after it that would looks like part of the variable but isn't, enclose the variable name in {}:

print "foo${ids}bar";

Which equals operator (== vs ===) should be used in JavaScript comparisons?

Yes! It does matter.

=== operator in javascript checks value as well as type where as == operator just checks the value (does type conversion if required).

enter image description here

You can easily test it. Paste following code in an HTML file and open it in browser

<script>

function onPageLoad()
{
    var x = "5";
    var y = 5;
    alert(x === 5);
};

</script>

</head>

<body onload='onPageLoad();'>

You will get 'false' in alert. Now modify the onPageLoad() method to alert(x == 5); you will get true.

How can I use an ES6 import in Node.js?

Back to Jonathan002's original question about

"... what version supports the new ES6 import statements?"

based on the article by Dr. Axel Rauschmayer, there is a plan to have it supported by default (without the experimental command line flag) in Node.js 10.x LTS. According to node.js's release plan as it is on 3/29, 2018, it's likely to become available after Apr 2018, while LTS of it will begin on October 2018.

Uninstall Node.JS using Linux command line?

If you installed node using curl + yum:

sudo curl --silent --location https://rpm.nodesource.com/setup_4.x | bash -
sudo yum -y install nodejs

Then you can remove it using yum:

sudo yum remove nodejs

Note that using the curl script causes the wrong version of node to be installed. There is a bug that causes node v6.7 to be installed instead of v4.x intended by the path (../setup_4.x) used in the curl script.

Select distinct values from a table field

By example:

# select distinct code from Platform where id in ( select platform__id from Build where product=p)
pl_ids = Build.objects.values('platform__id').filter(product=p)
platforms = Platform.objects.values_list('code', flat=True).filter(id__in=pl_ids).distinct('code')
platforms = list(platforms) if platforms else []

How can I run a PHP script in the background after a form is submitted?

Doing some experimentation with exec and shell_exec I have uncovered a solution that worked perfectly! I choose to use shell_exec so I can log every notification process that happens (or doesn't). (shell_exec returns as a string and this was easier than using exec, assigning the output to a variable and then opening a file to write to.)

I'm using the following line to invoke the email script:

shell_exec("/path/to/php /path/to/send_notifications.php '".$post_id."' 'alert' >> /path/to/alert_log/paging.log &");

It is important to notice the & at the end of the command (as pointed out by @netcoder). This UNIX command runs a process in the background.

The extra variables surrounded in single quotes after the path to the script are set as $_SERVER['argv'] variables that I can call within my script.

The email script then outputs to my log file using the >> and will output something like this:

[2011-01-07 11:01:26] Alert Notifications Sent for http://alerts.illinoisstate.edu/2049 (SCRIPT: 38.71 seconds)
[2011-01-07 11:01:34] CRITICAL ERROR: Alert Notifications NOT sent for http://alerts.illinoisstate.edu/2049 (SCRIPT: 23.12 seconds)

Change font-weight of FontAwesome icons?

Another solution I've used to create lighter fontawesome icons, similar to the webkit-text-stroke approach but more portable, is to set the color of the icon to the same as the background (or transparent) and use text-shadow to create an outline:

.fa-outline-dark-gray {
    color: #fff;
    text-shadow: -1px -1px 0 #999,
            1px -1px 0 #999,
           -1px 1px 0 #999,
            1px 1px 0 #999;
}

It doesn't work in ie <10, but at least it's not restricted to webkit browsers.

Position Absolute + Scrolling

You need to wrap the text in a div element and include the absolutely positioned element inside of it.

<div class="container">
    <div class="inner">
        <div class="full-height"></div>
        [Your text here]
    </div>
</div>

Css:

.inner: { position: relative; height: auto; }
.full-height: { height: 100%; }

Setting the inner div's position to relative makes the absolutely position elements inside of it base their position and height on it rather than on the .container div, which has a fixed height. Without the inner, relatively positioned div, the .full-height div will always calculate its dimensions and position based on .container.

_x000D_
_x000D_
* {_x000D_
  box-sizing: border-box;_x000D_
}_x000D_
_x000D_
.container {_x000D_
  position: relative;_x000D_
  border: solid 1px red;_x000D_
  height: 256px;_x000D_
  width: 256px;_x000D_
  overflow: auto;_x000D_
  float: left;_x000D_
  margin-right: 16px;_x000D_
}_x000D_
_x000D_
.inner {_x000D_
  position: relative;_x000D_
  height: auto;_x000D_
}_x000D_
_x000D_
.full-height {_x000D_
  position: absolute;_x000D_
  top: 0;_x000D_
  left: 0;_x000D_
  right: 128px;_x000D_
  bottom: 0;_x000D_
  height: 100%;_x000D_
  background: blue;_x000D_
}
_x000D_
<div class="container">_x000D_
  <div class="full-height">_x000D_
  </div>_x000D_
</div>_x000D_
_x000D_
<div class="container">_x000D_
  <div class="inner">_x000D_
    <div class="full-height">_x000D_
    </div>_x000D_
_x000D_
    Lorem ipsum dolor sit amet, consectetur adipisicing elit. Aspernatur mollitia maxime facere quae cumque perferendis cum atque quia repellendus rerum eaque quod quibusdam incidunt blanditiis possimus temporibus reiciendis deserunt sequi eveniet necessitatibus_x000D_
    maiores quas assumenda voluptate qui odio laboriosam totam repudiandae? Doloremque dignissimos voluptatibus eveniet rem quasi minus ex cumque esse culpa cupiditate cum architecto! Facilis deleniti unde suscipit minima obcaecati vero ea soluta odio_x000D_
    cupiditate placeat vitae nesciunt quis alias dolorum nemo sint facere. Deleniti itaque incidunt eligendi qui nemo corporis ducimus beatae consequatur est iusto dolorum consequuntur vero debitis saepe voluptatem impedit sint ea numquam quia voluptate_x000D_
    quidem._x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

http://jsfiddle.net/M5cTN/

How do you wait for input on the same Console.WriteLine() line?

Use Console.Write instead, so there's no newline written:

Console.Write("What is your name? ");
var name = Console.ReadLine();

WindowsError: [Error 126] The specified module could not be found

In Windows, it's possible. You will need to install: Visual C++ Redistributable for Visual Studio 2015. I had the same problem and I installed both version (Windows x86 and Windows x64). Apparently both are necessary to make it work.

How to get all selected values from <select multiple=multiple>?

$('#application_student_groups option:selected').toArray().map(item => item.value)

How to select specified node within Xpath node sets by index with Selenium?

(//*[@attribute='value'])[index] to find target of element while your finding multiple matches in it

How do I install cygwin components from the command line?

I wanted a solution for this similar to apt-get --print-uris, but unfortunately apt-cyg doesn't do this. The following is a solution that allowed me to download only the packages I needed, with their dependencies, and copy them to the target for installation. Here is a bash script that parses the output of apt-cyg into a list of URIs:

#!/usr/bin/bash

package=$1
depends=$( \
    apt-cyg depends $package \
    | perl -ne 'while ($x = /> ([^>\s]+)/g) { print "$1\n"; }' \
    | sort \
    | uniq)
depends=$(echo -e "$depends\n$package")
for curpkg in $depends; do
    if ! grep -q "^$curpkg " /etc/setup/installed.db; then
    apt-cyg show $curpkg \
        | perl -ne '
            if ($x = /install: ([^\s]+)/) { 
                print "$1\n"; 
            }
            if (/\[prev\]/) { 
                exit; 
            }'
    fi
done

The above will print out the paths of the packages that need downloading, relative to the cygwin mirror root, omitting any packages that are already installed. To download them, I wrote the output to a file cygwin-packages-list and then used wget:

mirror=http://cygwin.mirror.constant.com/
uris=$(for line in $(cat cygwin-packages-list); do echo "$mirror$line"; done)
wget -x $uris

The installer can then be used to install from a local cache directory. Note that for this to work I needed to copy setup.ini from a previous cygwin package cache to the directory with the downloaded files (otherwise the installer doesn't know what's what).

How do I disable the security certificate check in Python requests

If you want to send exactly post request with verify=False option, fastest way is to use this code:

import requests

requests.api.request('post', url, data={'bar':'baz'}, json=None, verify=False)

How do I convert a org.w3c.dom.Document object to a String?

A Scala version based on Zaz's answer.

  case class DocumentEx(document: Document) {
    def toXmlString(pretty: Boolean = false):Try[String] = {
      getStringFromDocument(document, pretty)
    }
  }

  implicit def documentToDocumentEx(document: Document):DocumentEx = {
    DocumentEx(document)
  }

  def getStringFromDocument(doc: Document, pretty:Boolean): Try[String] = {
    try
    {
      val domSource= new DOMSource(doc)
      val writer = new StringWriter()
      val result = new StreamResult(writer)
      val tf = TransformerFactory.newInstance()
      val transformer = tf.newTransformer()
      if (pretty)
        transformer.setOutputProperty(OutputKeys.INDENT, "yes")
      transformer.transform(domSource, result)
      Success(writer.toString);
    }
    catch {
      case ex: TransformerException =>
        Failure(ex)
    }
  }

With that, you can do either doc.toXmlString() or call the getStringFromDocument(doc) function.

How to wait until WebBrowser is completely loaded in VB.NET?

Another option is to check if it's busy with a timer:

Set the timer as disabled by default. Then whenever navigating, enable it. i.e.:

WebBrowser1.Navigate("https://www.somesite.com")
tmrBusy.Enabled = True

And the timer:

    Private Sub tmrBusy_Tick(sender As Object, e As EventArgs) Handles tmrBusy.Tick

        If WebBrowser1.IsBusy = True Then

            Debug.WriteLine("WB Busy ...")

        Else

            Debug.WriteLine("WB Done.")
            tmrBusy.Enabled = False

        End If

    End Sub

Add row to query result using select

You use it like this:

SELECT  age, name
FROM    users
UNION
SELECT  25 AS age, 'Betty' AS name

Use UNION ALL to allow duplicates: if there is a 25-years old Betty among your users, the second query will not select her again with mere UNION.

When should an Excel VBA variable be killed or set to Nothing?

VBA uses a garbage collector which is implemented by reference counting.

There can be multiple references to a given object (for example, Dim aw = ActiveWorkbook creates a new reference to Active Workbook), so the garbage collector only cleans up an object when it is clear that there are no other references. Setting to Nothing is an explicit way of decrementing the reference count. The count is implicitly decremented when you exit scope.

Strictly speaking, in modern Excel versions (2010+) setting to Nothing isn't necessary, but there were issues with older versions of Excel (for which the workaround was to explicitly set)

Setting up SSL on a local xampp/apache server

I have been through all the answers and tutorials over the internet but here are the basic steps to enable SSL (https) on localhost with XAMPP:

Required:

  1. Run -> "C:\xampp\apache\makecert.bat" (double-click on windows) Fill passowords of your choice, hit Enter for everything BUT define "localhost"!!! Be careful when asked here:

    Common Name (e.g. server FQDN or YOUR name) []:localhost

    (Certificates are issued per domain name zone only!)

  2. Restart apache
  3. Chrome -> Settings -> Search "Certificate" -> Manage Certificates -> Trusted Root Certification Authorities -> Import -> "C:\xampp\apache\conf\ssl.crt\server.crt" -> Must Ask "YES" for confirmation!
  4. https://localhost/testssl.php -> [OK, Now Green!] (any html test file)

Optional: (if above doesn't work, do more of these steps)

  1. Run XAMPP As admin (Start -> XAMPP -> right-click -> Run As Administrator)
  2. XAMPP -> Apache -> Config -> httpd.conf ("C:\xampp\apache\conf\httpd.conf")

    LoadModule ssl_module modules/mod_ssl.so (remove # form the start of line)

  3. XAMPP -> Apache -> Config -> php.ini ("C:\xampp\php\php.ini")

    extension=php_openssl.dll (remove ; from the start of line)

  4. Restart apache and chrome!

Check any problems or the status of your certificate:

Chrome -> F12 -> Security -> View Certificate

How can I show a combobox in Android?

The questions is perfectly valid and clear since Spinner and ComboBox (read it: Spinner where you can provide a custom value as well) are two different things.

I was looking for the same thing myself and I wasn't satisfied with the given answers. So I created my own thing. Perhaps some will find the following hints useful. I am not providing the full source code as I am using some legacy calls in my own project. It should be pretty clear anyway.

Here is the screenshot of the final thing:

ComboBox on Android

The first thing was to create a view that will look the same as the spinner that hasn't been expanded yet. In the screenshot, on the top of the screen (out of focus) you can see the spinner and the custom view right bellow it. For that purpose I used LinearLayout (actually, I inherited from Linear Layout) with style="?android:attr/spinnerStyle". LinearLayout contains TextView with style="?android:attr/spinnerItemStyle". Complete XML snippet would be:

<com.example.comboboxtest.ComboBox 
    style="?android:attr/spinnerStyle"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    >

    <TextView
        android:id="@+id/textView"
        style="?android:attr/spinnerItemStyle"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:ellipsize="marquee"
        android:singleLine="true"
        android:text="January"
        android:textAlignment="inherit" 
    />

</com.example.comboboxtest.ComboBox>

As, I mentioned earlier ComboBox inherits from LinearLayout. It also implements OnClickListener which creates a dialog with a custom view inflated from the XML file. Here is the inflated view:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical" 
    >
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" 
        >
        <EditText
            android:id="@+id/editText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:ems="10"
            android:hint="Enter custom value ..." >

            <requestFocus />
        </EditText>

        <Button
            android:id="@+id/button"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="OK" 
        />
    </LinearLayout>

    <ListView
        android:id="@+id/listView1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" 
    />

</LinearLayout>

There are two more listeners that you need to implement: onItemClick for the list and onClick for the button. Both of these set the selected value and dismiss the dialog.

For the list, you want it to look the same as expanded Spinner, you can do that providing the list adapter with the appropriate (Spinner) style like this:

ArrayAdapter<String> adapter = 
    new ArrayAdapter<String>(
        activity,
        android.R.layout.simple_spinner_dropdown_item, 
        states
    );

More or less, that should be it.

Bootstrap css hides portion of container below navbar navbar-fixed-top

I guess the problem you have is related to the dynamic height that the fixed navbar at the top has. For example, when a user logs in, you need to display some kind of "Hello [User Name]" and when the name is too wide, the navbar needs to use more height so this text doesn't overlap with the navbar menu. As the navbar has the style "position: fixed", the body stays underneath it and a taller part of it becomes hidden so you need to "dynamically" change the padding at the top every time the navbar height changes which would happen in the following case scenarios:

  1. The page is loaded / reloaded.
  2. The browser window is resized as this could hit a different responsive breakpoint.
  3. The navbar content is modified directly or indirectly as this could provoke a height change.

This dynamicity is not covered by regular CSS so I can only think of one way to solve this problem if the user has JavaScript enabled. Please try the following jQuery code snippet to resolve case scenarios 1 and 2; for case scenario 3 please remember to call the function onResize() after any change in the navbar content:

_x000D_
_x000D_
var onResize = function() {_x000D_
  // apply dynamic padding at the top of the body according to the fixed navbar height_x000D_
  $("body").css("padding-top", $(".navbar-fixed-top").height());_x000D_
};_x000D_
_x000D_
// attach the function to the window resize event_x000D_
$(window).resize(onResize);_x000D_
_x000D_
// call it also when the page is ready after load or reload_x000D_
$(function() {_x000D_
  onResize();_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
_x000D_
_x000D_
_x000D_

Sending credentials with cross-domain posts?

Functionality is supposed to be broken in jQuery 1.5.

Since jQuery 1.5.1 you should use xhrFields param.

$.ajaxSetup({
    type: "POST",
    data: {},
    dataType: 'json',
    xhrFields: {
       withCredentials: true
    },
    crossDomain: true
});

Docs: http://api.jquery.com/jQuery.ajax/

Reported bug: http://bugs.jquery.com/ticket/8146

Change directory in Node.js command prompt

To switch to the another directory process.chdir("../");

Find the nth occurrence of substring in a string

For the special case where you search for the n'th occurence of a character (i.e. substring of length 1), the following function works by building a list of all positions of occurences of the given character:

def find_char_nth(string, char, n):
    """Find the n'th occurence of a character within a string."""
    return [i for i, c in enumerate(string) if c == char][n-1]

If there are fewer than n occurences of the given character, it will give IndexError: list index out of range.

This is derived from @Zv_oDD's answer and simplified for the case of a single character.

How can I add raw data body to an axios request?

The key is to use "Content-Type": "text/plain" as mentioned by @MadhuBhat.

axios.post(path, code, { headers: { "Content-Type": "text/plain" } }).then(response => {
    console.log(response);
});

A thing to note if you use .NET is that a raw string to a controller will return 415 Unsupported Media Type. To get around this you need to encapsulate the raw string in hyphens like this and send it as "Content-Type": "application/json":

axios.post(path, "\"" + code + "\"", { headers: { "Content-Type": "application/json" } }).then(response => {
    console.log(response);
});

C# Controller:

[HttpPost]
public async Task<ActionResult<string>> Post([FromBody] string code)
{
    return Ok(code);
}

https://weblog.west-wind.com/posts/2017/sep/14/accepting-raw-request-body-content-in-aspnet-core-api-controllers

You can also make a POST with query params if that helps:

.post(`/mails/users/sendVerificationMail`, null, { params: {
  mail,
  firstname
}})
.then(response => response.status)
.catch(err => console.warn(err));

This will POST an empty body with the two query params:

POST http://localhost:8000/api/mails/users/sendVerificationMail?mail=lol%40lol.com&firstname=myFirstName

Source: https://stackoverflow.com/a/53501339/3850405

Get a json via Http Request in NodeJS

http sends/receives data as strings... this is just the way things are. You are looking to parse the string as json.

var jsonObject = JSON.parse(data);

How to parse JSON using Node.js?

What is the `zero` value for time.Time in Go?

You should use the Time.IsZero() function instead:

func (Time) IsZero

func (t Time) IsZero() bool
IsZero reports whether t represents the zero time instant, January 1, year 1, 00:00:00 UTC.

Overwriting my local branch with remote branch

Your local branch likely has modifications to it you want to discard. To do this, you'll need to use git reset to reset the branch head to the last spot that you diverged from the upstream repo's branch. Use git branch -v to find the sha1 id of the upstream branch, and reset your branch it it using git reset SHA1ID. Then you should be able to do a git checkout to discard the changes it left in your directory.

Note: always do this on a backed-up repo. That way you can assure you're self it worked right. Or if it didn't, you have a backup to revert to.

Close a MessageBox after several seconds

There is an codeproject project avaliable HERE that provides this functuanility.

Following many threads here on SO and other boards this cant be done with the normal MessageBox.

Edit:

I have an idea that is a bit ehmmm yeah..

Use a timer and start in when the MessageBox appears. If your MessageBox only listens to the OK Button (only 1 possibility) then use the OnTick-Event to emulate an ESC-Press with SendKeys.Send("{ESC}"); and then stop the timer.

AngularJS: ng-model not binding to ng-checked for checkboxes

You don't need ng-checked when you use ng-model. If you're performing CRUD on your HTML Form, just create a model for CREATE mode that is consistent with your EDIT mode during the data-binding:

CREATE Mode: Model with default values only

$scope.dataModel = {
   isItemSelected: true,
   isApproved: true,
   somethingElse: "Your default value"
}

EDIT Mode: Model from database

$scope.dataModel = getFromDatabaseWithSameStructure()

Then whether EDIT or CREATE mode, you can consistently make use of your ng-model to sync with your database.

How do I "un-revert" a reverted Git commit?

Reverting the revert will do the trick

For example,

If abcdef is your commit and ghijkl is the commit you have when you reverted the commit abcdef, then run:

git revert ghijkl

This will revert the revert

MySQL limit from descending order

Let's say we have a table with a column time and you want the last 5 entries, but you want them returned to you in asc order, not desc, this is how you do it:

select * from ( select * from `table` order by `time` desc limit 5 ) t order by `time` asc

axios post request to send form data

https://www.npmjs.com/package/axios

Its Working

// "content-type": "application/x-www-form-urlencoded", // commit this

import axios from 'axios';

let requestData = {
      username : "[email protected]",
      password: "123456
    };
   
    const url = "Your Url Paste Here";

    let options = {
      method: "POST",
      headers: { 
        'Content-type': 'application/json; charset=UTF-8',

        Authorization: 'Bearer ' + "your token Paste Here",
      },
      data: JSON.stringify(requestData),
      url
    };
    axios(options)
      .then(response => {
        console.log("K_____ res :- ", response);
        console.log("K_____ res status:- ", response.status);
      })
      .catch(error => {
        console.log("K_____ error :- ", error);
      });

fetch request

fetch(url, {
    method: 'POST',
    body: JSON.stringify(requestPayload),           
    headers: {
        'Content-type': 'application/json; charset=UTF-8',
        Authorization: 'Bearer ' + token,
    },
})
    // .then((response) => response.json()) .  // commit out this part if response body is empty
    .then((json) => {
        console.log("response :- ", json);
    }).catch((error)=>{
        console.log("Api call error ", error.message);
        alert(error.message);
});

how to show alternate image if source image is not found? (onerror working in IE but not in mozilla)

If you're open to a PHP solution:

<td><img src='<?PHP
  $path1 = "path/to/your/image.jpg";
  $path2 = "alternate/path/to/another/image.jpg";

  echo file_exists($path1) ? $path1 : $path2; 
  ?>' alt='' />
</td>

////EDIT OK, here's a JS version:

<table><tr>
<td><img src='' id='myImage' /></td>
</tr></table>

<script type='text/javascript'>
  document.getElementById('myImage').src = "newImage.png";

  document.getElementById('myImage').onload = function() { 
    alert("done"); 
  }

  document.getElementById('myImage').onerror = function() { 
    alert("Inserting alternate");
    document.getElementById('myImage').src = "alternate.png"; 
  }
</script>

How to find my php-fpm.sock?

I faced this same issue on CentOS 7 years later

Posting hoping that it may help others...

Steps:

FIRST, configure the php-fpm settings:

-> systemctl stop php-fpm.service

-> cd /etc/php-fpm.d

-> ls -hal (should see a www.conf file)

-> cp www.conf www.conf.backup (back file up just in case)

-> vi www.conf

-> :/listen = (to get to the line we need to change)

-> i (to enter VI's text insertion mode)

-> change from listen = 127.0.0.1:9000 TO listen = /var/run/php-fpm/php-fpm.sock

-> Esc then :/listen.owner (to find it) then i (to change)

-> UNCOMMENT the listen.owner = nobody AND listen.group = nobody lines

-> Hit Esc then type :/user = then i

-> change user = apache TO user = nginx

-> AND change group = apache TO group = nginx

-> Hit Esc then :wq (to save and quit)

-> systemctl start php-fpm.service (now you will have a php-fpm.sock file)

SECOND, you configure your server {} block in your /etc/nginx/nginx.conf file. Then run:systemctl restart nginx.service

FINALLY, create a new .php file in your /usr/share/nginx/html directory for your Nginx server to serve up via the internet browser as a test.

-> vi /usr/share/nginx/html/mytest.php

-> type o

-> <?php echo date("Y/m/d-l"); ?> (PHP page will print date and day in browser)

-> Hit Esc

-> type :wq (to save and quite VI editor)

-> open up a browser and go to: http://yourDomainOrIPAddress/mytest.php (you should see the date and day printed)

font-family is inherit. How to find out the font-family in chrome developer pane?

I think op wants to know what the font that is used on a webpage is, and hoped that info might be findable in the 'inspect' pane.

Try adding the Whatfont Chrome extension.

How do I get the serial key for Visual Studio Express?

I believe that if you download the offline ISO image file, and use that to install Visual Studio Express, you won't have to register.

Go here and find the link that says "All - Offline Install ISO image file". Click on it to expand it, select your language, and then click "Download".

Otherwise, it's possible that online registration is simply down for a while, as the error message indicates. You have 30 days before it expires, so give it a few days before starting to panic.

How Do I Replace/Change The Heading Text Inside <h3></h3>, Using jquery?

Give an id to h3 like this:

<h3 id="headertag">Featured Offers</h3>

and in the javascript function do this :

document.getElementById("headertag").innerHTML = "Public Offers";

Unzipping files

I found jszip quite useful. I've used so far only for reading, but they have create/edit capabilities as well.

Code wise it looks something like this

var new_zip = new JSZip();
new_zip.load(file);
new_zip.files["doc.xml"].asText() // this give you the text in the file

One thing I noticed is that it seems the file has to be in binary stream format (read using the .readAsArrayBuffer of FileReader(), otherwise I was getting errors saying I might have a corrupt zip file

Edit: Note from the 2.x to 3.0.0 upgrade guide:

The load() method and the constructor with data (new JSZip(data)) have been replaced by loadAsync().

Thanks user2677034

How to extract code of .apk file which is not working?

Any .apk file from market or unsigned

  1. If you apk is downloaded from market and hence signed Install Astro File Manager from market. Open Astro > Tools > Application Manager/Backup and select the application to backup on to the SD card . Mount phone as USB drive and access 'backupsapps' folder to find the apk of target app (lets call it app.apk) . Copy it to your local drive same is the case of unsigned .apk.

  2. Download Dex2Jar zip from this link: SourceForge

  3. Unzip the downloaded zip file.

  4. Open command prompt & write the following command on reaching to directory where dex2jar exe is there and also copy the apk in same directory.

    dex2jar targetapp.apk file(./dex2jar app.apk on terminal)

  5. http://jd.benow.ca/ download decompiler from this link.

  6. Open ‘targetapp.apk.dex2jar.jar’ with jd-gui File > Save All Sources to sava the class files in jar to java files.

Crystal Reports - Adding a parameter to a 'Command' query

The solution I came up with was as follows:

  1. Create the SQL query in your favorite query dev tool
  2. In Crystal Reports, within the main report, create parameter to pass to the subreport
  3. Create sub report, using the 'Add Command' option in the 'Data' portion of the 'Report Creation Wizard' and the SQL query from #1.
  4. Once the subreport is added to the main report, right click on the subreport, choose 'Change Subreport Links...', select the link field, and uncheck 'Select data in subreport based on field:'

    NOTE: You may have to initially add the parameter with the 'Select data in subreport based on field:' checked, then go back to 'Change Subreport Links ' and uncheck it after the subreport has been created.

  5. In the subreport, click the 'Report' menu, 'Select Expert', use the 'Formula Editor', set the SQL column from #1 either equal to or like the parameter(s) selected in #4.

                    (Subreport SQL Column)  (Parameter from Main Report)
            Example:  {Command.Project} like {?Pm-?Proj_Name}
    

Html5 Full screen video

You can do it with jQuery.

I have my video and controls in their own <div> like this:

<div id="videoPlayer" style="width:520px; -webkit-border-radius:10px; height:420px; background-color:white; position:relative; float:left; left:25px; top:55px;" align="center">

    <video controls width="500" height="400" style="background-color:black; margin-top:10px; -webkit-border-radius:10px;">
         <source src="videos/gin.mp4" type="video/mp4" />
    </video>

    <script>  
        video.removeAttribute('controls');  
    </script> 

    <div id="vidControls" style="position:relative; width:100%; height:50px; background-color:white; -webkit-border-bottom-left-radius:10px; -webkit-border-bottom-right-radius:10px; padding-top:10px; padding-bottom:10px;">

         <table width="100%" height="100%" border="0">

             <tr>
                 <td width="100%" align="center" valign="middle" colspan="4"><input class="vidPos" type="range" value="0" step="0.1" style="width:500px;" /></td>
             </tr>

             <tr>
                 <td width="100%" align="center" valign="middle"><a href="javascript:;" class="playVid">Play</a></td>
                 <td width="100%" align="center" valign="middle"><a href="javascript:;" class="vol">Vol</a></td>
                 <td width="100%" align="left" valign="middle"><p class="timer"><strong>0:00</strong> / 0:00</p></td>
                 <td width="100%" align="center" valign="middle"><a href="javascript:;" class="fullScreen">Full</a></td>
              </tr>

            </table>

         </div>

      </div>

And then my jQuery for the .fullscreen class is:

var fullscreen = 0;

$(".fullscreen").click(function(){
  if(fullscreen == 0){
    fullscreen = 1;
    $("video").appendTo('body');
    $("#vidControls").appendTo('body');
    $("video").css('position', 'absolute').css('width', '100%').css('height', '90%').css('margin', 0).css('margin-top', '5%').css('top', '0').css('left', '0').css('float', 'left').css('z-index', 600);
    $("#vidControls").css('position', 'absolute').css('bottom', '5%').css('width', '90%').css('backgroundColor', 'rgba(150, 150, 150, 0.5)').css('float', 'none').css('left', '5%').css('z-index', 700).css('-webkit-border-radius', '10px');

}
else
    {

        fullscreen = 0;

        $("video").appendTo('#videoPlayer');
        $("#vidControls").appendTo('#videoPlayer');

        //change <video> css back to normal

        //change "#vidControls" css back to normal

    }

});

It needs a little cleaning up as I'm still working on it but that should work for most browsers as far as I can see.

Hope it helps!

Find the files existing in one directory but not in the other

GNU grep can inverse the search with the option -v. This makes grep reporting the lines, which do not match. By this you can remove the files in dir2 from the list of files in dir1.

grep -v -F -x -f <(find dir2 -type f -printf '%P\n') <(find dir1 -type f -printf '%P\n')

The options -F -x tell grep to perform a string search on the whole line.

Does a valid XML file require an XML declaration?

It is only required if you aren't using the default values for version and encoding (which you are in that example).

Repair all tables in one go

You may need user name and password:

mysqlcheck -A --auto-repair -uroot -p

You will be prompted for password.

mysqlcheck -A --auto-repair -uroot -p{{password here}}

If you want to put in cron, BUT your password will be visible in plain text!

What are NDF Files?

From Files and Filegroups Architecture

Secondary data files

Secondary data files make up all the data files, other than the primary data file. Some databases may not have any secondary data files, while others have several secondary data files. The recommended file name extension for secondary data files is .ndf.

Also from file extension NDF - Microsoft SQL Server secondary data file

See Understanding Files and Filegroups

Secondary data files are optional, are user-defined, and store user data. Secondary files can be used to spread data across multiple disks by putting each file on a different disk drive. Additionally, if a database exceeds the maximum size for a single Windows file, you can use secondary data files so the database can continue to grow.

The recommended file name extension for secondary data files is .ndf.

/

For example, three files, Data1.ndf, Data2.ndf, and Data3.ndf, can be created on three disk drives, respectively, and assigned to the filegroup fgroup1. A table can then be created specifically on the filegroup fgroup1. Queries for data from the table will be spread across the three disks; this will improve performance. The same performance improvement can be accomplished by using a single file created on a RAID (redundant array of independent disks) stripe set. However, files and filegroups let you easily add new files to new disks.

How can I wrap text in a label using WPF?

We need to put some kind of control that can wrap text like textblock/textbox

 <Label Width="120" Height="100" >
        <TextBlock TextWrapping="Wrap">
            this is a very long text inside a textblock and this needs to be on multiline.
        </TextBlock>
    </Label>

Best way to implement keyboard shortcuts in a Windows Forms application?

You probably forgot to set the form's KeyPreview property to True. Overriding the ProcessCmdKey() method is the generic solution:

protected override bool ProcessCmdKey(ref Message msg, Keys keyData) {
  if (keyData == (Keys.Control | Keys.F)) {
    MessageBox.Show("What the Ctrl+F?");
    return true;
  }
  return base.ProcessCmdKey(ref msg, keyData);
}

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

Change your code to:

System.out.println("AM or PM?"); 
Scanner TimeOfDayQ = new Scanner(System.in);
TimeOfDayStringQ = TimeOfDayQ.next();

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

...

if(Hours == 13){
    if (TimeOfDayStringQ.equals("AM")) {
        TimeOfDayStringQ = "PM"; // <--
    } else {
        TimeOfDayStringQ = "AM"; // <--
    }
            Hours = 1;
    }
 }

How to align td elements in center

Give a style inside the td element or in your scss file, like this:

vertical-align: 
    middle;

What's the difference between @Component, @Repository & @Service annotations in Spring?

Good enough answers are here to explain the whats-the-difference-between-component-repository-service-annotations. I would like to share the difference between @Controller & @RestController

@Controller vs RestController

@RestController:

enter image description here

  • This annotation is a specialized version of @Controller which adds @Controller and @ResponseBody annotation automatically. so we do not have to add @ResponseBody to our mapping methods. That means @ResponseBody is default active.
  • If you use @RestController you cannot return a view (By using Viewresolver in Spring/Spring-Boot)
  • @RestController also converts the response to JSON/XML automatically as @ResponseBody makes the returned objects to something that could be in the body, e.g. JSON or XML

@Controller

enter image description here

  • @Controller is used to mark classes as Spring MVC Controller. This annotation is just a specialized version of @Component and it allows the controller classes to be auto-detected based on classpath scanning.
  • @Controller you can return a view in Spring web MVC.

More Detailed View

sh: react-scripts: command not found after running npm start

If anyone still have this problem after trying these solutions: check your project path as node has some issues working with spaced dir names. I changed all directories names that had spaces in their names and it worked perfectly.

solution idea taken from: https://npm.community/t/react-scripts-not-found/8574

i am using yarn BTW

Entity Framework - Linq query with order by and group by

Try moving the order by after group by:

var groupByReference = (from m in context.Measurements
                        group m by new { m.Reference } into g
                        order by g.Avg(i => i.CreationTime)
                        select g).Take(numOfEntries).ToList();

Display a RecyclerView in Fragment

I faced same problem. And got the solution when I use this code to call context. I use Grid Layout. If you use another one you can change.

   recyclerView.setLayoutManager(new GridLayoutManager(getActivity(),1));

if you have adapter to set. So you can follow this. Just call the getContext

  adapter = new Adapter(getContext(), myModelList);

If you have Toast to show, use same thing above

   Toast.makeText(getContext(), "Error in "+e, Toast.LENGTH_SHORT).show();

Hope this will work.

HappyCoding

Adding css class through aspx code behind

controlName.CssClass="CSS Class Name";

working example follows below

txtBank.CssClass = "csError";

DateTime.Today.ToString("dd/mm/yyyy") returns invalid DateTime Value

There are only minor error.Use MM instead of mm ,so it will be effective write as below:

 @DateTime.Now.ToString("dd/MM/yyy")

List of Timezone IDs for use with FindTimeZoneById() in C#?

You will find complete list of time zone with its GMToffsets here and you can use "Name of Time Zone" column value to find time zone by ID

e.g

TimeZoneInfo objTimeZoneInfo = TimeZoneInfo.FindTimeZoneById("Dateline Standard Time");

You will get time zone info class that contains dateline standard time time zone which is used for GMT-12:00.

View not attached to window manager crash

Override onConfigurationChanged and dismiss progress dialog. If progress dialog is created in portrait and dismisses in landscape then it will throw View not attached to window manager error.

Also stop the progress bar and stop the async task in onPause(), onBackPressed and onDestroy method.

if(asyncTaskObj !=null && asyncTaskObj.getStatus().equals(AsyncTask.Status.RUNNING)){

    asyncTaskObj.cancel(true);

}

Failed to find target with hash string 'android-25'

Make sure your computer is connected to the internet, then click on the link that comes with the error message i.e "install missing platform(s) and sync project". Give it a few seconds especially if your computer has low specs, it will bring up a window called SDK Quickfix Installation and everything is straightforward from there.