Programs & Examples On #Smalldatetime

How to select data from 30 days?

Try this : Using this you can select date by last 30 days,

SELECT DATEADD(DAY,-30,GETDATE())

check for null date in CASE statement, where have I gone wrong?

Try:

select
     id,
     StartDate,
CASE WHEN StartDate IS NULL
    THEN 'Awaiting'
    ELSE 'Approved' END AS StartDateStatus
FROM myTable

You code would have been doing a When StartDate = NULL, I think.


NULL is never equal to NULL (as NULL is the absence of a value). NULL is also never not equal to NULL. The syntax noted above is ANSI SQL standard and the converse would be StartDate IS NOT NULL.

You can run the following:

SELECT CASE WHEN (NULL = NULL) THEN 1 ELSE 0 END AS EqualityCheck,
CASE WHEN (NULL <> NULL) THEN 1 ELSE 0 END AS InEqualityCheck,
CASE WHEN (NULL IS NULL) THEN 1 ELSE 0 END AS NullComparison

And this returns:

EqualityCheck = 0
InEqualityCheck = 0
NullComparison = 1

For completeness, in SQL Server you can:

SET ANSI_NULLS OFF;

Which would result in your equals comparisons working differently:

SET ANSI_NULLS OFF

SELECT CASE WHEN (NULL = NULL) THEN 1 ELSE 0 END AS EqualityCheck,
CASE WHEN (NULL <> NULL) THEN 1 ELSE 0 END AS InEqualityCheck,
CASE WHEN (NULL IS NULL) THEN 1 ELSE 0 END AS NullComparison

Which returns:

EqualityCheck = 1
InEqualityCheck = 0
NullComparison = 1

But I would highly recommend against doing this. People subsequently maintaining your code might be compelled to hunt you down and hurt you...

Also, it will no longer work in upcoming versions of SQL server:

https://msdn.microsoft.com/en-GB/library/ms188048.aspx

Convert Text to Date?

Blast from the past but I think I found an easy answer to this. The following worked for me. I think it's the equivalent of selecting the cell hitting F2 and then hitting enter, which makes Excel recognize the text as a date.

Columns("A").Select
Selection.Value = Selection.Value

Uncompress tar.gz file

gunzip <filename>

then

tar -xvf <tar-file-name>

RecyclerView - How to smooth scroll to top of item on a certain position?

RecyclerView is designed to be extensible, so there is no need to subclass the LayoutManager (as droidev suggested) just to perform the scrolling.

Instead, just create a SmoothScroller with the preference SNAP_TO_START:

RecyclerView.SmoothScroller smoothScroller = new LinearSmoothScroller(context) {
  @Override protected int getVerticalSnapPreference() {
    return LinearSmoothScroller.SNAP_TO_START;
  }
};

Now you set the position where you want to scroll to:

smoothScroller.setTargetPosition(position);

and pass that SmoothScroller to the LayoutManager:

layoutManager.startSmoothScroll(smoothScroller);

Laravel 4 Eloquent Query Using WHERE with OR AND OR?

$a, $b, $c, $d can be dynamic values by the query

 ->where(function($query) use ($a, $b)
        {
            $query->where('a', $a)
                  ->orWhere('b',$b);
        })
 ->where(function($query) use ($c, $d)
        {
            $query->where('c', $c)
                  ->orWhere('d',$d);
        })

Prevent Sequelize from outputting SQL to the console on execution of query?

I solved a lot of issues by using the following code. Issues were : -

  1. Not connecting with database
  2. Database connection Rejection issues
  3. Getting rid of logs in console (specific for this).
const sequelize = new Sequelize("test", "root", "root", {
  host: "127.0.0.1",
  dialect: "mysql",
  port: "8889",
  connectionLimit: 10,
  socketPath: "/Applications/MAMP/tmp/mysql/mysql.sock",
  // It will disable logging
  logging: false
});

Event for Handling the Focus of the EditText

For those of us who this above valid solution didnt work, there's another workaround here

 searchView.setOnQueryTextFocusChangeListener(new View.OnFocusChangeListener() {
        @Override
        public void onFocusChange(View view, boolean isFocused) {
            if(!isFocused)
            {
                Toast.makeText(MainActivity.this,"not focused",Toast.LENGTH_SHORT).show();

            }
        }
    });

React Native: JAVA_HOME is not set and no 'java' command could be found in your PATH

I fixed this issue by installing jre, I have jdk already installed but jre was not installed.

Creating a Plot Window of a Particular Size

As the accepted solution of @Shane is not supported in RStudio (see here) as of now (Sep 2015), I would like to add an advice to @James Thompson answer regarding workflow:

If you use SumatraPDF as viewer you do not need to close the PDF file before making changes to it. Sumatra does not put a opened file in read-only and thus does not prevent it from being overwritten. Therefore, once you opened your PDF file with Sumatra, changes out of RStudio (or any other R IDE) are immediately displayed in Sumatra.

Jquery sortable 'change' event element position

UPDATED: 26/08/2016 to use the latest jquery and jquery ui version plus bootstrap to style it.

$(function() {
    $('#sortable').sortable({
        start: function(event, ui) {
            var start_pos = ui.item.index();
            ui.item.data('start_pos', start_pos);
        },
        change: function(event, ui) {
            var start_pos = ui.item.data('start_pos');
            var index = ui.placeholder.index();
            if (start_pos < index) {
                $('#sortable li:nth-child(' + index + ')').addClass('highlights');
            } else {
                $('#sortable li:eq(' + (index + 1) + ')').addClass('highlights');
            }
        },
        update: function(event, ui) {
            $('#sortable li').removeClass('highlights');
        }
    });
});

.htaccess: where is located when not in www base dir

The .htaccess is either in the root-directory of your webpage or in the directory you want to protect.

Make sure to make them visible in your filesystem, because AFAIK (I'm no unix expert either) files starting with a period are invisible by default on unix-systems.

Angular 2 - Using 'this' inside setTimeout

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

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

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

Key value pairs using JSON

var object = {
    key1 : {
        name : 'xxxxxx',
        value : '100.0'
    },
    key2 : {
        name : 'yyyyyyy',
        value : '200.0'
    },
    key3 : {
        name : 'zzzzzz',
        value : '500.0'
    },
}

If thats how your object looks and you want to loop each name and value then I would try and do something like.

$.each(object,function(key,innerjson){
    /*
        key would be key1,key2,key3
        innerjson would be the name and value **
    */

    //Alerts and logging of the variable.
    console.log(innerjson); //should show you the value    
    alert(innerjson.name); //Should say xxxxxx,yyyyyy,zzzzzzz
});

How to create a localhost server to run an AngularJS project

Assuming you already have node.js installed, you can use browser sync for synchronized browser testing.

Android Studio Gradle project "Unable to start the daemon process /initialization of VM"

Open your project and press Ctrl + Alt + Shift + S to open Project Structure. There under JDK location check Use embedded JDK (recommended).

How to query data out of the box using Spring data JPA by both Sort and Pageable?

In my case, to use Pageable and Sorting at the same time I used like below. In this case I took all elements using pagination and sorting by id by descending order:

modelRepository.findAll(PageRequest.of(page, 10, Sort.by("id").descending()))

Like above based on your requirements you can sort data with 2 columns as well.

How to get Url Hash (#) from server side

That's because the browser doesn't transmit that part to the server, sorry.

how to show progress bar(circle) in an activity having a listview before loading the listview with data

I used this one for list view loading may helpful.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:paddingLeft="5dp"
android:paddingRight="5dp" >

<LinearLayout
    android:id="@+id/progressbar_view"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:gravity="center_horizontal"
    android:orientation="vertical" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:orientation="horizontal" >

        <ProgressBar
            style="?android:attr/progressBarStyle"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical|center_horizontal" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical|center_horizontal"
            android:text="Loading data..." />
    </LinearLayout>

    <View
        android:layout_width="fill_parent"
        android:layout_height="1dp"
        android:background="#C0C0C0" />
</LinearLayout>

<ListView
    android:id="@+id/listView"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_marginTop="1dip"
    android:visibility="gone" />

</RelativeLayout>

and my MainActivity class is,

public class MainActivity extends Activity {
ListView listView;
LinearLayout layout;
List<String> stringValues;
ArrayAdapter<String> adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    listView = (ListView) findViewById(R.id.listView);
    layout = (LinearLayout) findViewById(R.id.progressbar_view);

    stringValues = new ArrayList<String>();

    adapter = new ArrayAdapter<String>(this,
            android.R.layout.simple_list_item_1, stringValues);

    listView.setAdapter(adapter);
    new Task().execute();
}

class Task extends AsyncTask<String, Integer, Boolean> {
    @Override
    protected void onPreExecute() {
        layout.setVisibility(View.VISIBLE);
        listView.setVisibility(View.GONE);
        super.onPreExecute();
    }

    @Override
    protected void onPostExecute(Boolean result) {
        layout.setVisibility(View.GONE);
        listView.setVisibility(View.VISIBLE);
        adapter.notifyDataSetChanged();
        super.onPostExecute(result);
    }

    @Override
    protected Boolean doInBackground(String... params) {
        stringValues.add("String 1");
        stringValues.add("String 2");
        stringValues.add("String 3");
        stringValues.add("String 4");
        stringValues.add("String 5");

        try {
            Thread.sleep(3000);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}
}

this activity display progress for 3sec then it will display listview, instead of adding data statically to stringValues list you can get data from server in doInBackground() and display it.

How to update Android Studio automatically?

Yes you are right. There is no built in mechanism for automatically updation of Android Studio. You have to manually download it and configure it.

What is .htaccess file?

What

  • A settings file for the server
  • Cannot be accessed by end-user
  • There is no need to reboot the server, changes work immediately
  • It might serve as a bridge between your code and server

We can do

  • URL rewriting
  • Custom error pages
  • Caching
  • Redirections
  • Blocking ip's

Immutable array in Java

If you need (for performance reason or to save memory) native 'int' instead of 'java.lang.Integer', then you would probably need to write your own wrapper class. There are various IntArray implementations on the net, but none (I found) was immutable: Koders IntArray, Lucene IntArray. There are probably others.

Convert alphabet letters to number in Python

This is a function I used to use for this purpose. Works for both uppercase and lowercase.

def convert_char(old):
    if len(old) != 1:
        return 0
    new = ord(old)
    if 65 <= new <= 90:
        # Upper case letter
        return new - 64
    elif 97 <= new <= 122:
        # Lower case letter
        return new - 96
    # Unrecognized character
    return 0

Use stored procedure to insert some data into a table

If you are trying to return back the ID within the scope, using the SCOPE_IDENTITY() would be a better approach. I would not advice to use @@IDENTITY, as this can return any ID.

CREATE PROC [dbo].[sp_Test] (
  @myID int output,
  @myFirstName nvarchar(50),
  @myLastName nvarchar(50),
  @myAddress nvarchar(50),
  @myPort int
) AS
BEGIN
    INSERT INTO Dvds (myFirstName, myLastName, myAddress, myPort)
    VALUES (@myFirstName, @myLastName, @myAddress, @myPort);

    SET @myID = SCOPE_IDENTITY();
END
GO

Why is C so fast, and why aren't other languages as fast or faster?

It's not so much about the language as the tools and libraries. The available libraries and compilers for C are much older than for newer languages. You might think this would make them slower, but au contraire.

These libraries were written at a time when processing power and memory were at a premium. They had to be written very efficiently in order to work at all. Developers of C compilers have also had a long time to work in all sorts of clever optimizations for different processors. C's maturity and wide adoption makes for a signficant advantage over other languages of the same age. It also gives C a speed advantage over newer tools that don't emphasize raw performance as much as C had to.

UITableView example for Swift

Here is the Swift 4 version.

import Foundation
import UIKit

class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource
{ 
    var tableView: UITableView = UITableView()
    let animals = ["Horse", "Cow", "Camel", "Sheep", "Goat"]
    let cellReuseIdentifier = "cell"

    override func viewDidLoad()
    {
        super.viewDidLoad()

        tableView.frame = CGRect(x: 0, y: 50, width: UIScreen.main.bounds.size.width, height: UIScreen.main.bounds.size.height)
        tableView.delegate = self
        tableView.dataSource = self
        tableView.register(UITableViewCell.self, forCellReuseIdentifier: cellReuseIdentifier)

        self.view.addSubview(tableView)
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
    {
        return animals.count
    }

    internal func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
    {
        let cell:UITableViewCell = tableView.dequeueReusableCell(withIdentifier: cellReuseIdentifier) as UITableViewCell!

        cell.textLabel?.text = animals[indexPath.row]

        return cell
    }

    private func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: IndexPath)
    {
        print("You tapped cell number \(indexPath.row).")
    }

}

How to merge two json string in Python?

What do you mean by merging? JSON objects are key-value data structure. What would be a key and a value in this case? I think you need to create new directory and populate it with old data:

d = {}
d["new_key"] = jsonStringA[<key_that_you_did_not_mention_here>] + \ 
               jsonStringB["timestamp_in_ms"]

Merging method is obviously up to you.

java SSL and cert keystore

SSL properties are set at the JVM level via system properties. Meaning you can either set them when you run the program (java -D....) Or you can set them in code by doing System.setProperty.

The specific keys you have to set are below:

javax.net.ssl.keyStore- Location of the Java keystore file containing an application process's own certificate and private key. On Windows, the specified pathname must use forward slashes, /, in place of backslashes.

javax.net.ssl.keyStorePassword - Password to access the private key from the keystore file specified by javax.net.ssl.keyStore. This password is used twice: To unlock the keystore file (store password), and To decrypt the private key stored in the keystore (key password).

javax.net.ssl.trustStore - Location of the Java keystore file containing the collection of CA certificates trusted by this application process (trust store). On Windows, the specified pathname must use forward slashes, /, in place of backslashes, \.

If a trust store location is not specified using this property, the SunJSSE implementation searches for and uses a keystore file in the following locations (in order):

  1. $JAVA_HOME/lib/security/jssecacerts
  2. $JAVA_HOME/lib/security/cacerts

javax.net.ssl.trustStorePassword - Password to unlock the keystore file (store password) specified by javax.net.ssl.trustStore.

javax.net.ssl.trustStoreType - (Optional) For Java keystore file format, this property has the value jks (or JKS). You do not normally specify this property, because its default value is already jks.

javax.net.debug - To switch on logging for the SSL/TLS layer, set this property to ssl.

Sort arrays of primitive types in descending order

I think it would be best not to re-invent the wheel and use Arrays.sort().

Yes, I saw the "descending" part. The sorting is the hard part, and you want to benefit from the simplicity and speed of Java's library code. Once that's done, you simply reverse the array, which is a relatively cheap O(n) operation. Here's some code I found to do this in as little as 4 lines:

for (int left=0, right=b.length-1; left<right; left++, right--) {
    // exchange the first and last
    int temp = b[left]; b[left]  = b[right]; b[right] = temp;
}

Adding Google Play services version to your app's manifest?

For my case, I just restart my Eclipse and it works.

I have been working for 2 weeks without shutting it down, I think it goes haywire.

Thanks for the suggestion though Ewoks!

How do I add multiple conditions to "ng-disabled"?

Wanny is correct. The && operator doesn't work in HTML. With Angular, you must use the double pipes (||)for multiple conditions.

How to SUM and SUBTRACT using SQL?

ah homework...

So wait, you need to deduct the balance of items in stock from the total number of those items that have been ordered? I have to tell you that sounds a bit backwards. Generally I think people do it the other way round. Deduct the total number of items ordered from the balance.

If you really need to do that though... Assuming that ITEM is unique in stock_bal...

SELECT s.ITEM, SUM(m.QTY) - s.QTY AS result
FROM stock_bal s
INNER JOIN master_table m ON m.ITEM = s.ITEM
GROUP BY s.ITEM, s.QTY

How to capture the screenshot of a specific element rather than entire page using Selenium Webdriver?

We can get the element screenshot by cropping entire page screenshot as below:

driver.get("http://www.google.com");
WebElement ele = driver.findElement(By.id("hplogo"));

// Get entire page screenshot
File screenshot = ((TakesScreenshot)driver).getScreenshotAs(OutputType.FILE);
BufferedImage  fullImg = ImageIO.read(screenshot);

// Get the location of element on the page
Point point = ele.getLocation();

// Get width and height of the element
int eleWidth = ele.getSize().getWidth();
int eleHeight = ele.getSize().getHeight();

// Crop the entire page screenshot to get only element screenshot
BufferedImage eleScreenshot= fullImg.getSubimage(point.getX(), point.getY(),
    eleWidth, eleHeight);
ImageIO.write(eleScreenshot, "png", screenshot);

// Copy the element screenshot to disk
File screenshotLocation = new File("C:\\images\\GoogleLogo_screenshot.png");
FileUtils.copyFile(screenshot, screenshotLocation);

Generate pdf from HTML in div using Javascript

  • No depenencies, pure JS
  • To add CSS or images - do not use relative URLs, use full URLs http://...domain.../path.css or so. It creates separate HTML document and it has no context of main thing.
  • you can also embed images as base64

This served me for years now:

export default function printDiv({divId, title}) {
  let mywindow = window.open('', 'PRINT', 'height=650,width=900,top=100,left=150');

  mywindow.document.write(`<html><head><title>${title}</title>`);
  mywindow.document.write('</head><body >');
  mywindow.document.write(document.getElementById(divId).innerHTML);
  mywindow.document.write('</body></html>');

  mywindow.document.close(); // necessary for IE >= 10
  mywindow.focus(); // necessary for IE >= 10*/

  mywindow.print();
  mywindow.close();

  return true;
}

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

Go to /var/log/ and run cat postgres.log Here you will find the reason for the failure of postgres. If it is a smart shut down then probably your icu4c version (C++ library for Unicode) is not proper which is linked with postgres. So run the following commands.

brew upgrade brew cleanup This should work ;)

EF Migrations: Rollback last applied migration?

I want to add some clarification to this thread:

Update-Database -TargetMigration:"name_of_migration"

What you are doing above is saying that you want to rollback all migrations UNTIL you're left with the migration specified. Thus, if you use GET-MIGRATIONS and you find that you have A, B, C, D, and E, then using this command will rollback E and D to get you to C:

Update-Database -TargetMigration:"C"

Also, unless anyone can comment to the contrary, I noticed that you can use an ordinal value and the short -Target switch (thus, -Target is the same as -TargetMigration). If you want to rollback all migrations and start over, you can use:

Update-Database -Target:0

0, above, would rollback even the FIRST migration (this is a destructive command--be sure you know what you're doing before you use it!)--something you cannot do if you use the syntax above that requires the name of the target migration (the name of the 0th migration doesn't exist before a migration is applied!). So in that case, you have to use the 0 (ordinal) value. Likewise, if you have applied migrations A, B, C, D, and E (in that order), then the ordinal 1 should refer to A, ordinal 2 should refer to B, and so on. So to rollback to B you could use either:

Update-Database -TargetMigration:"B"

or

Update-Database -TargetMigration:2

Edit October 2019:

According to this related answer on a similar question, correct command is -Target for EF Core 1.1 while it is -Migration for EF Core 2.0.

Converting Epoch time into the datetime

Try this:

>>> import time
>>> time.strftime("%Y-%m-%d %H:%M:%S", time.gmtime(1347517119))
'2012-09-12 23:18:39'

Also in MySQL, you can FROM_UNIXTIME like:

INSERT INTO tblname VALUES (FROM_UNIXTIME(1347517119))

For your 2nd question, it is probably because getbbb_class.end_time is a string. You can convert it to numeric like: float(getbbb_class.end_time)

Iterating through a JSON object

If you can store the json string in a variable jsn_string

import json

jsn_list = json.loads(json.dumps(jsn_string)) 
   for lis in jsn_list:
       for key,val in lis.items():
           print(key, val)

Output :

title Baby (Feat. Ludacris) - Justin Bieber
description Baby (Feat. Ludacris) by Justin Bieber on Grooveshark
link http://listen.grooveshark.com/s/Baby+Feat+Ludacris+/2Bqvdq
pubDate Wed, 28 Apr 2010 02:37:53 -0400
pubTime 1272436673
TinyLink http://tinysong.com/d3wI
SongID 24447862
SongName Baby (Feat. Ludacris)
ArtistID 1118876
ArtistName Justin Bieber
AlbumID 4104002
AlbumName My World (Part II);
http://tinysong.com/gQsw
LongLink 11578982
GroovesharkLink 11578982
Link http://tinysong.com/d3wI
title Feel Good Inc - Gorillaz
description Feel Good Inc by Gorillaz on Grooveshark
link http://listen.grooveshark.com/s/Feel+Good+Inc/1UksmI
pubDate Wed, 28 Apr 2010 02:25:30 -0400
pubTime 1272435930

How to generate .env file for laravel?

Just tried both ways and in both ways I got generated .env file:

enter image description here

Composer should automatically create .env file. In the post-create-project-cmd section of the composer.json you can find:

"post-create-project-cmd": [
  "php -r \"copy('.env.example', '.env');\"",
  "php artisan key:generate"
]

Both ways use the same composer.json file, so there shoudn't be any difference.

I suggest you to update laravel/installer to the last version: 1.2 and try again:

composer global require "laravel/installer=~1.2"

You can always generate .env file manually by running:

cp .env.example .env
php artisan key:generate

Adding calculated column(s) to a dataframe in pandas

You could have is_hammer in terms of row["Open"] etc. as follows

def is_hammer(rOpen,rLow,rClose,rHigh):
    return lower_wick_at_least_twice_real_body(rOpen,rLow,rClose) \
       and closed_in_top_half_of_range(rHigh,rLow,rClose)

Then you can use map:

df["isHammer"] = map(is_hammer, df["Open"], df["Low"], df["Close"], df["High"])

How to display a readable array - Laravel

as suggested, you can use 'die and dump' such as

dd($var)

or only 'dump', without dying,

dump($var)

List all virtualenv

Run workon with no argument to list available environments.

Converting an int into a 4 byte char array (C)

The problem is arising as unsigned char is a 4 byte number not a 1 byte number as many think, so change it to

union {
unsigned int integer;
char byte[4];
} temp32bitint;

and cast while printing, to prevent promoting to 'int' (which C does by default)

printf("%u, %u \n", (unsigned char)Buffer[0], (unsigned char)Buffer[1]);

"The system cannot find the file specified"

Considering that a LocalDb instance only intended for use in development. LocalDb is not available for production servers When you deploy the final result.

I think your connection string is pointing to a LocalDb instance and you need to take certain steps to turn it into the SQL Server database. It's not just a matter of copying an mdf file either. It will possibly differ from one hosting company to another, but typically, you need to create a backup of your existing database (a .bak file) and then restore that to the hosting company's SQL Server. You should ask them where you can find instructions on deploying your database into production.

How do I add a newline using printf?

To write a newline use \n not /n the latter is just a slash and a n

Importing lodash into angular2 + typescript application

I successfully imported lodash in my project with the following commands:

npm install lodash --save
typings install lodash --save

Then i imported it in the following way:

import * as _ from 'lodash';

and in systemjs.config.js i defined this:

map: { 'lodash' : 'node_modules/lodash/lodash.js' }

How to call a method daily, at specific time, in C#?

The best method that I know of and probably the simplest is to use the Windows Task Scheduler to execute your code at a specific time of day or have you application run permanently and check for a particular time of day or write a windows service that does the same.

A Simple AJAX with JSP example

I have used jQuery AJAX to make AJAX requests.

Check the following code:

<html>
<head>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js"></script>
    <script type="text/javascript">
        $(document).ready(function() {
            $('#call').click(function ()
            {
                $.ajax({
                    type: "post",
                    url: "testme", //this is my servlet
                    data: "input=" +$('#ip').val()+"&output="+$('#op').val(),
                    success: function(msg){      
                            $('#output').append(msg);
                    }
                });
            });

        });
    </script>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>JSP Page</title>
</head>
<body>
    input:<input id="ip" type="text" name="" value="" /><br></br>
    output:<input id="op" type="text" name="" value="" /><br></br>
    <input type="button" value="Call Servlet" name="Call Servlet" id="call"/>
    <div id="output"></div>
</body>

Can a table have two foreign keys?

Yes, MySQL allows this. You can have multiple foreign keys on the same table.

Get more details here FOREIGN KEY Constraints

jQuery attr() change img src

  1. Function imageMorph will create a new img element therefore the id is removed. Changed to

    $("#wrapper > img")

  2. You should use live() function for click event if you want you rocket lanch again.

Updated demo: http://jsfiddle.net/ynhat/QQRsW/4/

Finding square root without using sqrt function?

Why not try to use the Babylonian method for finding a square root.

Here is my code for it:

double sqrt(double number)
{
    double error = 0.00001; //define the precision of your result
    double s = number;

    while ((s - number / s) > error) //loop until precision satisfied 
    {
        s = (s + number / s) / 2;
    }
    return s;
}

Good luck!

How can I convert a date into an integer?

Using the builtin Date.parse function which accepts input in ISO8601 format and directly returns the desired integer return value:

var dates_as_int = dates.map(Date.parse);

C++ - Assigning null to a std::string

The else case is unncecessary, when you create a string object it is empty by default.

vertical align middle in <div>

It's simple: give the parent div this:

display: table;

and give the child div(s) this:

display: table-cell;
vertical-align: middle;

That's it!

_x000D_
_x000D_
.parent{_x000D_
    display: table;_x000D_
}_x000D_
.child{_x000D_
    display: table-cell;_x000D_
    vertical-align: middle;_x000D_
    padding-left: 20px;_x000D_
}
_x000D_
<div class="parent">_x000D_
    <div class="child">_x000D_
        Test_x000D_
    </div>_x000D_
    <div class="child">_x000D_
        Test Test Test <br/> Test Test Test_x000D_
    </div>_x000D_
    <div class="child">_x000D_
        Test Test Test <br/> Test Test Test <br/> Test Test Test_x000D_
    </div>_x000D_
<div>
_x000D_
_x000D_
_x000D_

Correct way to use Modernizr to detect IE?

Detecting CSS 3D transforms

Modernizr can detect CSS 3D transforms, yeah. The truthiness of Modernizr.csstransforms3d will tell you if the browser supports them.

The above link lets you select which tests to include in a Modernizr build, and the option you're looking for is available there.


Detecting IE specifically

Alternatively, as user356990 answered, you can use conditional comments if you're searching for IE and IE alone. Rather than creating a global variable, you can use HTML5 Boilerplate's <html> conditional comments trick to assign a class:

<!--[if lt IE 7]>      <html class="no-js lt-ie9 lt-ie8 lt-ie7"> <![endif]-->
<!--[if IE 7]>         <html class="no-js lt-ie9 lt-ie8"> <![endif]-->
<!--[if IE 8]>         <html class="no-js lt-ie9"> <![endif]-->
<!--[if gt IE 8]><!--> <html class="no-js"> <!--<![endif]-->

If you already have jQuery initialised, you can just check with $('html').hasClass('lt-ie9'). If you need to check which IE version you're in so you can conditionally load either jQuery 1.x or 2.x, you can do something like this:

myChecks.ltIE9 = (function(){
    var htmlElemClasses = document.querySelector('html').className.split(' ');
    if (!htmlElemClasses){return false;}
    for (var i = 0; i < htmlElemClasses.length; i += 1 ){
      var klass = htmlElemClasses[i];
      if (klass === 'lt-ie9'){
        return true;
      }
    }
    return false;
}());

N.B. IE conditional comments are only supported up to IE9 inclusive. From IE10 onwards, Microsoft encourages using feature detection rather than browser detection.


Whichever method you choose, you'd then test with

if ( myChecks.ltIE9 || Modernizr.csstransforms3d ){
    // iframe or flash fallback
} 

Don't take that || literally, of course.

Insert using LEFT JOIN and INNER JOIN

You have to be specific about the columns you are selecting. If your user table had four columns id, name, username, opted_in you must select exactly those four columns from the query. The syntax looks like:

INSERT INTO user (id, name, username, opted_in)
  SELECT id, name, username, opted_in 
  FROM user LEFT JOIN user_permission AS userPerm ON user.id = userPerm.user_id

However, there does not appear to be any reason to join against user_permission here, since none of the columns from that table would be inserted into user. In fact, this INSERT seems bound to fail with primary key uniqueness violations.

MySQL does not support inserts into multiple tables at the same time. You either need to perform two INSERT statements in your code, using the last insert id from the first query, or create an AFTER INSERT trigger on the primary table.

INSERT INTO user (name, username, email, opted_in) VALUES ('a','b','c',0);
/* Gets the id of the new row and inserts into the other table */
INSERT INTO user_permission (user_id, permission_id) VALUES (LAST_INSERT_ID(), 4)

Or using a trigger:

CREATE TRIGGER creat_perms AFTER INSERT ON `user`
FOR EACH ROW
BEGIN
  INSERT INTO user_permission (user_id, permission_id) VALUES (NEW.id, 4)
END

Call a child class method from a parent class object

I had the same situation and I found a way around with a bit of engineering as follows - -

  1. You have to have your method in parent class without any parameter and use - -

    Class<? extends Person> cl = this.getClass(); // inside parent class
    
  2. Now, with 'cl' you can access all child class fields with their name and initialized values by using - -

    cl.getDeclaredFields(); cl.getField("myfield"); // and many more
    
  3. In this situation your 'this' pointer will reference your child class object if you are calling parent method through your child class object.

  4. Another thing you might need to use is Object obj = cl.newInstance();

Let me know if still you got stucked somewhere.

Display Back Arrow on Toolbar

If you are using an ActionBarActivity then you can tell Android to use the Toolbar as the ActionBar like so:

Toolbar toolbar = (Toolbar) findViewById(R.id.my_awesome_toolbar);
setSupportActionBar(toolbar);

And then calls to

getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(true);

will work. You can also use that in Fragments that are attached to ActionBarActivities you can use it like this:

((ActionBarActivity) getActivity()).getSupportActionBar().setDisplayHomeAsUpEnabled(true);
((ActionBarActivity) getActivity()).getSupportActionBar().setDisplayShowHomeEnabled(true);

If you are not using ActionBarActivities or if you want to get the back arrow on a Toolbar that's not set as your SupportActionBar then you can use the following:

mActionBar.setNavigationIcon(getResources().getDrawable(R.drawable.ic_action_back));
mActionBar.setNavigationOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View v) {
       //What to do on back clicked
   }
});

If you are using android.support.v7.widget.Toolbar, then you should add the following code to your AppCompatActivity:

@Override
public boolean onSupportNavigateUp() {
    onBackPressed();
    return true;
}

Sql connection-string for localhost server

Do You have Internal Connection or External Connection. If you did Internal Connection then try this:

"Data Source=.\SQLEXPRESS;AttachDbFilename="Your PAth .mdf";Integrated Security=True;User Instance=True";

How to redirect the output of the time command to a file in Linux?

Since the output of 'time' command is error output, redirect it as standard output would be more intuitive to do further processing.

{ time sleep 1; } 2>&1 |  cat > time.txt

How to unmount, unrender or remove a component, from itself in a React/Redux/Typescript notification message

I've been to this post about 10 times now and I just wanted to leave my two cents here. You can just unmount it conditionally.

if (renderMyComponent) {
  <MyComponent props={...} />
}

All you have to do is remove it from the DOM in order to unmount it.

As long as renderMyComponent = true, the component will render. If you set renderMyComponent = false, it will unmount from the DOM.

Correct way to convert size in bytes to KB, MB, GB in JavaScript

Try this simple workaround.

var files = $("#file").get(0).files;               
                var size = files[0].size;
                if (size >= 5000000) {
alert("File size is greater than or equal to 5 MB");
}

Difference between Parameters.Add(string, object) and Parameters.AddWithValue

Without explicitly providing the type as in command.Parameters.Add("@ID", SqlDbType.Int);, it will try to implicitly convert the input to what it is expecting.

The downside of this, is that the implicit conversion may not be the most optimal of conversions and may cause a performance hit.

There is a discussion about this very topic here: http://forums.asp.net/t/1200255.aspx/1

How to search all loaded scripts in Chrome Developer Tools?

In Widows it is working for me. Control Shift F and then it opens a search window at the bottom. Make sure you expand the bottom area to see the new search window.

enter image description here

%matplotlib line magic causes SyntaxError in Python script

If you include the following code at the top of your script, matplotlib will run inline when in an IPython environment (like jupyter, hydrogen atom plugin...), and it will still work if you launch the script directly via command line (matplotlib won't run inline, and the charts will open in a pop-ups as usual).

from IPython import get_ipython
ipy = get_ipython()
if ipy is not None:
    ipy.run_line_magic('matplotlib', 'inline')

Error "The connection to adb is down, and a severe error has occurred."

Close Eclipse

Use this in the terminal:

sudo killall -9 adb

Run Eclipse.

ViewPager PagerAdapter not updating the View

All these answers are not working for me.

The only one worked for me is that I have to set the adapter to viewpager again, then it will refresh the content.

removeView(int pos) in my PagerAdaper

public void removeView(int index) {
       imageFileNames.remove(index);
       notifyDataSetChanged();
}

wherever I am removing the file I have to do like this

imagePagerAdapter.removeView(currentPosition);
viewPager.setAdapter(imagePagerAdapter);

EDIT:

This below method is effective, you can apply the below one.

public void updateView(int pos){
      viewPager.setAdapter(null);
      imagePagerAdapter =new ImagePagerAdapter(YOUR_CONTEXT,YOUR_CONTENT);
      viewPager.setAdapter(imagePagerAdapter);
      viewPager.setCurrentItem(pos);
}

replace YOUR_CONTEXT with your context and your content with your content name i.e. updated list or something.

Filezilla FTP Server Fails to Retrieve Directory Listing

Ok this helped a lot, I couldn't find a fix.

Simply, I already port forwarded the FTP port to my server. (The default is 14147, I'll use this as example)

Go to Edit > General settings, Listening port should be the one your using, in this case 14147.

Then go to Passive Mode Settings, I checked "Use Custom Port", and entered in the Range 50000 - 50100.

Then on your router, port forward 50000 - 50100 to the server IP locally.

IPv4 specific settings I left at default, reconnected my client, and bam now the file listing appears.

Ensure your servers firewall has an inbound rule set to accept 14147, and 50000-50100.

Basically what Evan stated. I can't attest to the security of opening these ports, but this is what finally got my Filezilla client and server to communicate and view files. Hope this helps someone.

SQL Server: Error converting data type nvarchar to numeric

I was running into this error while converting from nvarchar to float.
What I had to do was to use the LEFT function on the nvarchar field.

Example: Left(Field,4)

Basically, the query will look like:

Select convert(float,left(Field,4)) from TABLE

Just ridiculous that SQL would complicate it to this extent, while with C# it's a breeze!
Hope it helps someone out there.

Common sources of unterminated string literal

Scan the code that comes before the line# mentioned by error message. Whatever is unterminated has resulted in something downstream, (the blamed line#), to be flagged.

How to send a HTTP OPTIONS request from the command line?

The curl installed by default in Debian supports HTTPS since a great while back. (a long time ago there were two separate packages, one with and one without SSL but that's not the case anymore)

OPTIONS /path

You can send an OPTIONS request with curl like this:

curl -i -X OPTIONS http://example.org/path

You may also use -v instead of -i to see more output.

OPTIONS *

To send a plain * (instead of the path, see RFC 7231) with the OPTIONS method, you need curl 7.55.0 or later as then you can run a command line like:

curl -i --request-target "*" -X OPTIONS http://example.org

Plotting images side by side using matplotlib

One thing that I found quite helpful to use to print all images :

_, axs = plt.subplots(n_row, n_col, figsize=(12, 12))
axs = axs.flatten()
for img, ax in zip(imgs, axs):
    ax.imshow(img)
plt.show()

Storing Images in DB - Yea or Nay?

I'm the lead developer on an enterprise document management system in which some customers store hundreds of gigabytes of documents. Terabytes in the not too distant future. We use the file system approach for many of the reasons mentioned on this page plus another: archiving.

Many of our customers must conform to industry specific archival rules, such as storage to optical disk or storage in a non-proprietary format. Plus, you have the flexibility of simply adding more disks to a NAS device. If you have your files stored in your database, even with SQL Server 2008's file stream data type, your archival options just became a whole lot narrower.

should use size_t or ssize_t

ssize_t is used for functions whose return value could either be a valid size, or a negative value to indicate an error. It is guaranteed to be able to store values at least in the range [-1, SSIZE_MAX] (SSIZE_MAX is system-dependent).

So you should use size_t whenever you mean to return a size in bytes, and ssize_t whenever you would return either a size in bytes or a (negative) error value.

See: http://pubs.opengroup.org/onlinepubs/007908775/xsh/systypes.h.html

What is the different between RESTful and RESTless

Any model which don't identify resource and the action associated with is restless. restless is not any term but a slang term to represent all other services that doesn't abide with the above definition. In restful model resource is identified by URL (NOUN) and the actions(VERBS) by the predefined methods in HTTP protocols i.e. GET, POST, PUT, DELETE etc.

ExecutorService that interrupts tasks after a timeout

How about using the ExecutorService.shutDownNow() method as described in http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ExecutorService.html? It seems to be the simplest solution.

Calling Java from Python

I'm just beginning to use JPype 0.5.4.2 (july 2011) and it looks like it's working nicely...
I'm on Xubuntu 10.04

must appear in the GROUP BY clause or be used in an aggregate function

For me, it is not about a "common aggregation problem", but just about an incorrect SQL query. The single correct answer for "select the maximum avg for each cname..." is

SELECT cname, MAX(avg) FROM makerar GROUP BY cname;

The result will be:

 cname  |      MAX(avg)
--------+---------------------
 canada | 2.0000000000000000
 spain  | 5.0000000000000000

This result in general answers the question "What is the best result for each group?". We see that the best result for spain is 5 and for canada the best result is 2. It is true, and there is no error. If we need to display wmname also, we have to answer the question: "What is the RULE to choose wmname from resulting set?" Let's change the input data a bit to clarify the mistake:

  cname | wmname |        avg           
--------+--------+-----------------------
 spain  | zoro   |  1.0000000000000000
 spain  | luffy  |  5.0000000000000000
 spain  | usopp  |  5.0000000000000000

Which result do you expect on runnig this query: SELECT cname, wmname, MAX(avg) FROM makerar GROUP BY cname;? Should it be spain+luffy or spain+usopp? Why? It is not determined in the query how to choose "better" wmname if several are suitable, so the result is also not determined. That's why SQL interpreter returns an error - the query is not correct.

In the other word, there is no correct answer to the question "Who is the best in spain group?". Luffy is not better than usopp, because usopp has the same "score".

How to disable scientific notation?

You can effectively remove scientific notation in printing with this code:

options(scipen=999)

Oracle SQL Query for listing all Schemas in a DB

Most likely, you want

SELECT username
  FROM dba_users

That will show you all the users in the system (and thus all the potential schemas). If your definition of "schema" allows for a schema to be empty, that's what you want. However, there can be a semantic distinction where people only want to call something a schema if it actually owns at least one object so that the hundreds of user accounts that will never own any objects are excluded. In that case

SELECT username
  FROM dba_users u
 WHERE EXISTS (
    SELECT 1
      FROM dba_objects o
     WHERE o.owner = u.username )

Assuming that whoever created the schemas was sensible about assigning default tablespaces and assuming that you are not interested in schemas that Oracle has delivered, you can filter out those schemas by adding predicates on the default_tablespace, i.e.

SELECT username
  FROM dba_users
 WHERE default_tablespace not in ('SYSTEM','SYSAUX')

or

SELECT username
  FROM dba_users u
 WHERE EXISTS (
    SELECT 1
      FROM dba_objects o
     WHERE o.owner = u.username )
   AND default_tablespace not in ('SYSTEM','SYSAUX')

It is not terribly uncommon to come across a system where someone has incorrectly given a non-system user a default_tablespace of SYSTEM, though, so be certain that the assumptions hold before trying to filter out the Oracle-delivered schemas this way.

jQuery move to anchor location on page load

Description

You can do this using jQuery's .scrollTop() and .offset() method

Check out my sample and this jsFiddle Demonstration

Sample

$(function() {
    $(document).scrollTop( $("#header").offset().top );  
});

More Information

Android Studio Rendering Problems : The following classes could not be found

I had to change my values/styles.xml to

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">

Before that change, it was without 'Base'.

(IntelliJ IDEA 2017.2.4)

In TensorFlow, what is the difference between Session.run() and Tensor.eval()?

eval() can not handle the list object

tf.reset_default_graph()

a = tf.Variable(0.2, name="a")
b = tf.Variable(0.3, name="b")
z = tf.constant(0.0, name="z0")
for i in range(100):
    z = a * tf.cos(z + i) + z * tf.sin(b - i)
grad = tf.gradients(z, [a, b])

init = tf.global_variables_initializer()

with tf.Session() as sess:
    init.run()
    print("z:", z.eval())
    print("grad", grad.eval())

but Session.run() can

print("grad", sess.run(grad))

correct me if I am wrong

How can I show line numbers in Eclipse?

As simple as that. Ctrl+F10, then N, to Show or hide line numbers.

Reference : http://www.shortcutworld.com/en/win/Eclipse.html

Add a Progress Bar in WebView

You can try this code into your activity

    private void startWebView(WebView webView,String url) {
 webView.setWebViewClient(new WebViewClient() {
            ProgressDialog progressDialog;

            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                view.loadUrl(url);
                return false;
            }

            @Override
            public void onPageStarted(WebView view, String url, Bitmap favicon) {
                super.onPageStarted(view, url, favicon);
            }

            public void onLoadResource (WebView view, String url) {

                    if (progressDialog == null) {
                        progressDialog = new ProgressDialog(SponceredDetailsActivity.this);
                        progressDialog.setMessage("Loading...");
                        progressDialog.show();
                    }

            }
            public void onPageFinished(WebView view, String url) {
                try{
                    if (progressDialog.isShowing()) {
                        progressDialog.dismiss();
                        progressDialog = null;
                    }

                }catch(Exception exception){
                    exception.printStackTrace();
                }
            }

        });

        webView.getSettings().setJavaScriptEnabled(true);
        webView.loadUrl(url);
    }

Call this method using this way:

startWebView(web_view,"Your Url");

Sometimes if URL is dead it will redirected and it will come to onLoadResource() before onPageFinished method. For this reason progress bar will not dismis. To solve this issue see my this Answer.

Thanks :)

Styling HTML email for Gmail

I agree with everyone who supports classes AND inline styles. You might have learned this by now, but if there is a single mistake in your style sheet, Gmail will disregard it.

You might think that your CSS is perfect, because you've done it so often, why would I have mistakes in my CSS? Run it through the CSS Validator (for example http://www.css-validator.org/) and see what happens. I did that after encountering some Gmail display issues, and to my surprise, several Microsoft Outlook specific style declarations showed up as mistakes.

Which made sense to me, so I removed them from the style sheet and put them into a only for Microsoft code block, like so:

<!--[if mso]>
<style type="text/css">
body, table, td, .mobile-text {
font-family: Arial, sans-serif !important;
}
</style>
<xml>
  <o:OfficeDocumentSettings>
    <o:AllowPNG/>
    <o:PixelsPerInch>96</o:PixelsPerInch>
  </o:OfficeDocumentSettings>
</xml>
<![endif]-->

This is just a simple example, but, who know, it might come in handy some time.

How to SELECT in Oracle using a DBLINK located in a different schema?

I had the same problem I used the solution offered above - I dropped the SYNONYM, created a VIEW with the same name as the synonym. it had a select using the dblink , and gave GRANT SELECT to the other schema It worked great.

Oracle 'Partition By' and 'Row_Number' keyword

I know this is an old thread but PARTITION is the equiv of GROUP BY not ORDER BY. ORDER BY in this function is . . . ORDER BY. It's just a way to create uniqueness out of redundancy by adding a sequence number. Or you may eliminate the other redundant records by the WHERE clause when referencing the aliased column for the function. However, DISTINCT in the SELECT statement would probably accomplish the same thing in that regard.

how to access master page control from content page

I have a helper method for this in my System.Web.UI.Page class

protected T FindControlFromMaster<T>(string name) where T : Control
{
     MasterPage master = this.Master;
     while (master != null)
     {
         T control = master.FindControl(name) as T;
         if (control != null)
             return control;

         master = master.Master;
     }
     return null;
}

then you can access using below code.

Label lblStatus = FindControlFromMaster<Label>("lblStatus");
if(lblStatus!=null) 
    lblStatus.Text = "something";

How to call javascript function from asp.net button click event

If you don't need to initiate a post back when you press this button, then making the overhead of a server control isn't necesary.

<input id="addButton" type="button" value="Add" />

<script type="text/javascript" language="javascript">
     $(document).ready(function()
     {
         $('#addButton').click(function() 
         { 
             showDialog('#addPerson'); 
         });
     });
</script>

If you still need to be able to do a post back, you can conditionally stop the rest of the button actions with a little different code:

<asp:Button ID="buttonAdd" runat="server" Text="Add" />

<script type="text/javascript" language="javascript">
     $(document).ready(function()
     {
         $('#<%= buttonAdd.ClientID %>').click(function(e) 
         { 
             showDialog('#addPerson');

             if(/*Some Condition Is Not Met*/) 
                return false;
         });
     });
</script>

Define a global variable in a JavaScript function

If you are making a startup function, you can define global functions and variables this way:

function(globalScope)
{
    // Define something
    globalScope.something()
    {
        alert("It works");
    };
}(window)

Because the function is invoked globally with this argument, this is global scope here. So, the something should be a global thing.

C# delete a folder and all files and folders within that folder

You should use:

dir.Delete(true);

for recursively deleting the contents of that folder too. See MSDN DirectoryInfo.Delete() overloads.

Preventing form resubmission

There are two parts to the answer:

  1. Ensure duplicate posts don't mess with your data on the server side. To do this, embed a unique identifier in the post so that you can reject subsequent requests server side. This pattern is called Idempotent Receiver in messaging terms.

  2. Ensure the user isn't bothered by the possibility of duplicate submits by both

    • redirecting to a GET after the POST (POST redirect GET pattern)
    • disabling the button using javascript

Nothing you do under 2. will totally prevent duplicate submits. People can click very fast and hackers can post anyway. You always need 1. if you want to be absolutely sure there are no duplicates.

Fill remaining vertical space with CSS using display:flex

Use the flex-grow property to the main content div and give the dispaly: flex; to its parent;

_x000D_
_x000D_
body {_x000D_
    height: 100%;_x000D_
    position: absolute;_x000D_
    margin: 0;_x000D_
}_x000D_
section {_x000D_
  height: 100%;_x000D_
  display: flex;_x000D_
  flex-direction : column;_x000D_
}_x000D_
header {_x000D_
  background: tomato;_x000D_
}_x000D_
div {_x000D_
  flex: 1; /* or flex-grow: 1  */;_x000D_
  overflow-x: auto;_x000D_
  background: gold;_x000D_
}_x000D_
footer {_x000D_
  background: lightgreen;_x000D_
  min-height: 60px;_x000D_
}
_x000D_
<section>_x000D_
  <header>_x000D_
    header: sized to content_x000D_
    <br>(but is it really?)_x000D_
  </header>_x000D_
  <div>_x000D_
    main content: fills remaining space<br>_x000D_
    x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>_x000D_
    x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>_x000D_
    x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>_x000D_
    x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>_x000D_
    x<br>x<br>x<br>x<br>x<br>x<br>x<br>x<br>_x000D_
  </div>_x000D_
  <footer>_x000D_
    footer: fixed height in px_x000D_
  </footer>_x000D_
</section>
_x000D_
_x000D_
_x000D_

How to assign a heredoc value to a variable in Bash?

this is variation of Dennis method, looks more elegant in the scripts.

function definition:

define(){ IFS='\n' read -r -d '' ${1} || true; }

usage:

define VAR <<'EOF'
abc'asdf"
$(dont-execute-this)
foo"bar"''
EOF

echo "$VAR"

enjoy

p.s. made a 'read loop' version for shells that do not support read -d. should work with set -eu and unpaired backticks, but not tested very well:

define(){ o=; while IFS="\n" read -r a; do o="$o$a"'
'; done; eval "$1=\$o"; }

event.preventDefault() function not working in IE

To disable a keyboard key after IE9, use : e.preventDefault();

To disable a regular keyboard key under IE7/8, use : e.returnValue = false; or return false;

If you try to disable a keyboard shortcut (with Ctrl, like Ctrl+F) you need to add those lines :

try {
    e.keyCode = 0;
}catch (e) {}

Here is a full example for IE7/8 only :

document.attachEvent("onkeydown", function () {
    var e = window.event;

    //Ctrl+F or F3
    if (e.keyCode === 114 || (e.ctrlKey && e.keyCode === 70)) {
        //Prevent for Ctrl+...
        try {
            e.keyCode = 0;
        }catch (e) {}

        //prevent default (could also use e.returnValue = false;)
        return false;
    }
});

Reference : How to disable keyboard shortcuts in IE7 / IE8

TimeStamp on file name using PowerShell

Here's some PowerShell code that should work. You can combine most of this into fewer lines, but I wanted to keep it clear and readable.

[string]$filePath = "C:\tempFile.zip";

[string]$directory = [System.IO.Path]::GetDirectoryName($filePath);
[string]$strippedFileName = [System.IO.Path]::GetFileNameWithoutExtension($filePath);
[string]$extension = [System.IO.Path]::GetExtension($filePath);
[string]$newFileName = $strippedFileName + [DateTime]::Now.ToString("yyyyMMdd-HHmmss") + $extension;
[string]$newFilePath = [System.IO.Path]::Combine($directory, $newFileName);

Move-Item -LiteralPath $filePath -Destination $newFilePath;

Proper way of checking if row exists in table in PL/SQL block

Select 'YOU WILL SEE ME' as ANSWER from dual
where exists (select 1 from dual where 1 = 1);

Select 'YOU CAN NOT SEE ME' as ANSWER from dual
where exists (select 1 from dual where 1 = 0);

Select 'YOU WILL SEE ME, TOO' as ANSWER from dual
where not exists (select 1 from dual where 1 = 0);

How do I import an existing Java keystore (.jks) file into a Java installation?

You can bulk import all aliases from one keystore to another:

keytool -importkeystore -srckeystore source.jks -destkeystore dest.jks

jQuery: How to get the HTTP status code from within the $.ajax.error method?

You should create a map of actions using the statusCode setting:

$.ajax({
  statusCode: {
    400: function() {
      alert('400 status code! user error');
    },
    500: function() {
      alert('500 status code! server error');
    }
  }
});

Reference (Scroll to: 'statusCode')

EDIT (In response to comments)

If you need to take action based on the data returned in the response body (which seems odd to me), you will need to use error: instead of statusCode:

error:function (xhr, ajaxOptions, thrownError){
    switch (xhr.status) {
        case 404:
             // Take action, referencing xhr.responseText as needed.
    }
} 

Stop all active ajax requests in jQuery

Here's what I'm currently using to accomplish that.

$.xhrPool = [];
$.xhrPool.abortAll = function() {
  _.each(this, function(jqXHR) {
    jqXHR.abort();
  });
};
$.ajaxSetup({
  beforeSend: function(jqXHR) {
    $.xhrPool.push(jqXHR);
  }
});

Note: _.each of underscore.js is present, but obviously not necessary. I'm just lazy and I don't want to change it to $.each(). 8P

Link error "undefined reference to `__gxx_personality_v0'" and g++

It sounds like you're trying to link with your resulting object file with gcc instead of g++:

Note that programs using C++ object files must always be linked with g++, in order to supply the appropriate C++ libraries. Attempting to link a C++ object file with the C compiler gcc will cause "undefined reference" errors for C++ standard library functions:

$ g++ -Wall -c hello.cc
$ gcc hello.o       (should use g++)
hello.o: In function `main':
hello.o(.text+0x1b): undefined reference to `std::cout'
.....
hello.o(.eh_frame+0x11):
  undefined reference to `__gxx_personality_v0'

Source: An Introduction to GCC - for the GNU compilers gcc and g++

Browse files and subfolders in Python

You can use os.walk() to recursively iterate through a directory and all its subdirectories:

for root, dirs, files in os.walk(path):
    for name in files:
        if name.endswith((".html", ".htm")):
            # whatever

To build a list of these names, you can use a list comprehension:

htmlfiles = [os.path.join(root, name)
             for root, dirs, files in os.walk(path)
             for name in files
             if name.endswith((".html", ".htm"))]

Find column whose name contains a specific string

Getting name and subsetting based on Start, Contains, and Ends:

# from: https://stackoverflow.com/questions/21285380/find-column-whose-name-contains-a-specific-string
# from: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.Series.str.contains.html
# from: https://cmdlinetips.com/2019/04/how-to-select-columns-using-prefix-suffix-of-column-names-in-pandas/
# from: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.filter.html




import pandas as pd



data = {'spike_starts': [1,2,3], 'ends_spike_starts': [4,5,6], 'ends_spike': [7,8,9], 'not': [10,11,12]}
df = pd.DataFrame(data)



print("\n")
print("----------------------------------------")
colNames_contains = df.columns[df.columns.str.contains(pat = 'spike')].tolist() 
print("Contains")
print(colNames_contains)



print("\n")
print("----------------------------------------")
colNames_starts = df.columns[df.columns.str.contains(pat = '^spike')].tolist() 
print("Starts")
print(colNames_starts)



print("\n")
print("----------------------------------------")
colNames_ends = df.columns[df.columns.str.contains(pat = 'spike$')].tolist() 
print("Ends")
print(colNames_ends)



print("\n")
print("----------------------------------------")
df_subset_start = df.filter(regex='^spike',axis=1)
print("Starts")
print(df_subset_start)



print("\n")
print("----------------------------------------")
df_subset_contains = df.filter(regex='spike',axis=1)
print("Contains")
print(df_subset_contains)



print("\n")
print("----------------------------------------")
df_subset_ends = df.filter(regex='spike$',axis=1)
print("Ends")
print(df_subset_ends)

How to click or tap on a TextView text

OK I have answered my own question (but is it the best way?)

This is how to run a method when you click or tap on some text in a TextView:

package com.textviewy;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TextView;

public class TextyView extends Activity implements OnClickListener {

TextView t ;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    t = (TextView)findViewById(R.id.TextView01);
    t.setOnClickListener(this);
}

public void onClick(View arg0) {
    t.setText("My text on click");  
    }
}

and my main.xml is:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:orientation="vertical"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 >
<LinearLayout android:id="@+id/LinearLayout01" android:layout_width="wrap_content"             android:layout_height="wrap_content"></LinearLayout>
<ListView android:id="@+id/ListView01" android:layout_width="wrap_content"   android:layout_height="wrap_content"></ListView>
<LinearLayout android:id="@+id/LinearLayout02" android:layout_width="wrap_content"   android:layout_height="wrap_content"></LinearLayout>

<TextView android:text="This is my first text"
 android:id="@+id/TextView01" 
 android:layout_width="wrap_content" 
 android:textStyle="bold"
 android:textSize="28dip"
 android:editable = "true"
 android:clickable="true"
 android:layout_height="wrap_content">
 </TextView>
 </LinearLayout>

Removing u in list

u'AB' is just a text representation of the corresponding Unicode string. Here're several methods that create exactly the same Unicode string:

L = [u'AB', u'\x41\x42', u'\u0041\u0042', unichr(65) + unichr(66)]
print u", ".join(L)

Output

AB, AB, AB, AB

There is no u'' in memory. It is just the way to represent the unicode object in Python 2 (how you would write the Unicode string literal in a Python source code). By default print L is equivalent to print "[%s]" % ", ".join(map(repr, L)) i.e., repr() function is called for each list item:

print L
print "[%s]" % ", ".join(map(repr, L))

Output

[u'AB', u'AB', u'AB', u'AB']
[u'AB', u'AB', u'AB', u'AB']

If you are working in a REPL then a customizable sys.displayhook is used that calls repr() on each object by default:

>>> L = [u'AB', u'\x41\x42', u'\u0041\u0042', unichr(65) + unichr(66)]
>>> L
[u'AB', u'AB', u'AB', u'AB']
>>> ", ".join(L)
u'AB, AB, AB, AB'
>>> print ", ".join(L)
AB, AB, AB, AB

Don't encode to bytes. Print unicode directly.


In your specific case, I would create a Python list and use json.dumps() to serialize it instead of using string formatting to create JSON text:

#!/usr/bin/env python2
import json
# ...
test = [dict(email=player.email, gem=player.gem)
        for player in players]
print test
print json.dumps(test)

Output

[{'email': u'[email protected]', 'gem': 0}, {'email': u'test', 'gem': 0}, {'email': u'test', 'gem': 0}, {'email': u'test', 'gem': 0}, {'email': u'test', 'gem': 0}, {'email': u'test1', 'gem': 0}]
[{"email": "[email protected]", "gem": 0}, {"email": "test", "gem": 0}, {"email": "test", "gem": 0}, {"email": "test", "gem": 0}, {"email": "test", "gem": 0}, {"email": "test1", "gem": 0}]

How to determine the content size of a UIWebView?

I'm using a UIWebView that isn't a subview (and thus isn't part of the window hierarchy) to determine the sizes of HTML content for UITableViewCells. I found that the disconnected UIWebView doesn't report its size properly with -[UIWebView sizeThatFits:]. Additionally, as mentioned in https://stackoverflow.com/a/3937599/9636, you must set the UIWebView's frame height to 1 in order to get the proper height at all.

If the UIWebView's height is too big (i.e. you have it set to 1000, but the HTML content size is only 500):

UIWebView.scrollView.contentSize.height
-[UIWebView stringByEvaluatingJavaScriptFromString:@"document.height"]
-[UIWebView sizeThatFits:]

All return a height of 1000.

To solve my problem in this case, I used https://stackoverflow.com/a/11770883/9636, which I dutifully voted up. However, I only use this solution when my UIWebView.frame.width is the same as the -[UIWebView sizeThatFits:] width.

Escaping quotation marks in PHP

Either escape the quote:

$text1= "From time to \"time\"";

or use single quotes to denote your string:

$text1= 'From time to "time"';

In Matplotlib, what does the argument mean in fig.add_subplot(111)?

I think this would be best explained by the following picture:

enter image description here

To initialize the above, one would type:

import matplotlib.pyplot as plt
fig = plt.figure()
fig.add_subplot(221)   #top left
fig.add_subplot(222)   #top right
fig.add_subplot(223)   #bottom left
fig.add_subplot(224)   #bottom right 
plt.show()

How do I auto-hide placeholder text upon focus using css or jquery?

Demo is here: jsfiddle

Try this :

//auto-hide-placeholder-text-upon-focus
if(!$.browser.webkit){
$("input").each(
        function(){
            $(this).data('holder',$(this).attr('placeholder'));
            $(this).focusin(function(){
                $(this).attr('placeholder','');
            });
            $(this).focusout(function(){
                $(this).attr('placeholder',$(this).data('holder'));
            });

        });

}

How to set a string's color

Strings don't encapsulate color information. Are you thinking of setting the color in a console or in the GUI?

How to pass parameters using ui-sref in ui-router to controller

You simply misspelled $stateParam, it should be $stateParams (with an s). That's why you get undefined ;)

How to call a method in another class in Java?

You should capitalize names of your classes. After doing that do this in your school class,

Classroom cls = new Classroom();
cls.setTeacherName(newTeacherName);

Also I'd recommend you use some kind of IDE such as eclipse, which can help you with your code for instance generate getters and setters for you. Ex: right click Source -> Generate getters and setters

Print time in a batch file (milliseconds)

To time task in CMD is as simple as

echo %TIME% && your_command && cmd /v:on /c echo !TIME!

Random state (Pseudo-random number) in Scikit learn

If there is no randomstate provided the system will use a randomstate that is generated internally. So, when you run the program multiple times you might see different train/test data points and the behavior will be unpredictable. In case, you have an issue with your model you will not be able to recreate it as you do not know the random number that was generated when you ran the program.

If you see the Tree Classifiers - either DT or RF, they try to build a try using an optimal plan. Though most of the times this plan might be the same there could be instances where the tree might be different and so the predictions. When you try to debug your model you may not be able to recreate the same instance for which a Tree was built. So, to avoid all this hassle we use a random_state while building a DecisionTreeClassifier or RandomForestClassifier.

PS: You can go a bit in depth on how the Tree is built in DecisionTree to understand this better.

randomstate is basically used for reproducing your problem the same every time it is run. If you do not use a randomstate in traintestsplit, every time you make the split you might get a different set of train and test data points and will not help you in debugging in case you get an issue.

From Doc:

If int, randomstate is the seed used by the random number generator; If RandomState instance, randomstate is the random number generator; If None, the random number generator is the RandomState instance used by np.random.

Html.fromHtml deprecated in Android N

I had a lot of these warnings and I always use FROM_HTML_MODE_LEGACY so I made a helper class called HtmlCompat containing the following:

   @SuppressWarnings("deprecation")
   public static Spanned fromHtml(String source) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            return Html.fromHtml(source, Html.FROM_HTML_MODE_LEGACY);
        } else {
            return Html.fromHtml(source);
        }
    }

Removing header column from pandas dataframe

I think you cant remove column names, only reset them by range with shape:

print df.shape[1]
2

print range(df.shape[1])
[0, 1]

df.columns = range(df.shape[1])
print df
    0   1
0  23  12
1  21  44
2  98  21

This is same as using to_csv and read_csv:

print df.to_csv(header=None,index=False)
23,12
21,44
98,21

print pd.read_csv(io.StringIO(u""+df.to_csv(header=None,index=False)), header=None)
    0   1
0  23  12
1  21  44
2  98  21

Next solution with skiprows:

print df.to_csv(index=False)
A,B
23,12
21,44
98,21

print pd.read_csv(io.StringIO(u""+df.to_csv(index=False)), header=None, skiprows=1)
    0   1
0  23  12
1  21  44
2  98  21

Difference between <input type='button' /> and <input type='submit' />

<input type="button"> can be used anywhere, not just within form and they do not submit form if they are in one. Much better suited with Javascript.

<input type="submit"> should be used in forms only and they will send a request (either GET or POST) to specified URL. They should not be put in any HTML place.

Is there a way to make a DIV unselectable?

Not sure of your use case, but you could make it draggable.

If table exists drop table then create it, if it does not exist just create it

I needed to drop a table and re-create with a data from a view. I was creating a table out of a view and this is what I did:

DROP TABLE <table_name>;
CREATE TABLE <table_name> AS SELECT * FROM <view>;

The above worked for me using MySQL MariaDb.

Javascript: How to check if a string is empty?

If you want to know if it's an empty string use === instead of ==.

if(variable === "") {
}

This is because === will only return true if the values on both sides are of the same type, in this case a string.

for example: (false == "") will return true, and (false === "") will return false.

How to check if an integer is in a given range?

Use this code :

if (lowerBound <= val && val < upperBound)
or
if (lowerBound <= val && val <= upperBound)

Getting PEAR to work on XAMPP (Apache/MySQL stack on Windows)

I tried all of the other answers first but none of them seemed to work so I set the pear path statically in the pear config file

C:\xampp\php\pear\Config.php

find this code:

if (!defined('PEAR_INSTALL_DIR') || !PEAR_INSTALL_DIR) {
    $PEAR_INSTALL_DIR = PHP_LIBDIR . DIRECTORY_SEPARATOR . 'pear';
} 
else {
    $PEAR_INSTALL_DIR = PEAR_INSTALL_DIR;
}

and just replace it with this:

$PEAR_INSTALL_DIR = "C:\\xampp\\php\\pear";

I restarted apache and used the command:

pear config-all 

make sure the all of the paths no longer start with C:\php\pear

Inserting data to table (mysqli insert)

Okay, of course the question has been answered, but no-one seems to notice the third line of your code. It continuosly bugged me.

    <?php
    mysqli_connect("localhost","root","","web_table");
    mysql_select_db("web_table") or die(mysql_error());

for some reason, you made a mysqli connection to server, but you are trying to make a mysql connection to database.To get going, rather use

       $link = mysqli_connect("localhost","root","","web_table");
       mysqli_select_db ($link , "web_table" ) or die.....

or for where i began

     <?php $connection = mysqli_connect("localhost","root","","web_table");       
      global $connection; // global connection to databases - kill it once you're done

or just query with a $connection parameter as the other argument like above. Get rid of that third line.

Logarithmic returns in pandas dataframe

The results might seem similar, but that is just because of the Taylor expansion for the logarithm. Since log(1 + x) ~ x, the results can be similar.

However,

I am using the following code to get logarithmic returns, but it gives the exact same values as the pct.change() function.

is not quite correct.

import pandas as pd

df = pd.DataFrame({'p': range(10)})

df['pct_change'] = df.pct_change()
df['log_stuff'] = \
    np.log(df['p'].astype('float64')/df['p'].astype('float64').shift(1))
df[['pct_change', 'log_stuff']].plot();

enter image description here

is it possible to get the MAC address for machine using nmap

Not using nmap... but this is an alternative...

arp -n|grep -i B0:D3:93|awk '{print $1}'

C++11 thread-safe queue

Adding to the accepted answer, I would say that implementing a correct multi producers / multi consumers queue is difficult (easier since C++11, though)

I would suggest you to try the (very good) lock free boost library, the "queue" structure will do what you want, with wait-free/lock-free guarantees and without the need for a C++11 compiler.

I am adding this answer now because the lock-free library is quite new to boost (since 1.53 I believe)

What is the difference between a port and a socket?

A socket is a data I/O mechanism. A port is a contractual concept of a communication protocol. A socket can exist without a port. A port can exist witout a specific socket (e.g. if several sockets are active on the same port, which may be allowed for some protocols).

A port is used to determine which socket the receiver should route the packet to, with many protocols, but it is not always required and the receiving socket selection can be done by other means - a port is entirely a tool used by the protocol handler in the network subsystem. e.g. if a protocol does not use a port, packets can go to all listening sockets or any socket.

keycode and charcode

It is a conditional statement.

If browser supprts e.keyCode then take e.keyCode else e.charCode.

It is similar to

var code = event.keyCode || event.charCode

event.keyCode: Returns the Unicode value of a non-character key in a keypress event or any key in any other type of keyboard event.

event.charCode: Returns the Unicode value of a character key pressed during a keypress event.

TypeError: string indices must be integers, not str // working with dict

Actually I think that more general approach to loop through dictionary is to use iteritems():

# get tuples of term, courses
for term, term_courses in courses.iteritems():
    # get tuples of course number, info
    for course, info in term_courses.iteritems():
        # loop through info
        for k, v in info.iteritems():
            print k, v

output:

assistant Peter C.
prereq cs101
...
name Programming a Robotic Car
teacher Sebastian

Or, as Matthias mentioned in comments, if you don't need keys, you can just use itervalues():

for term_courses in courses.itervalues():
    for info in term_courses.itervalues():
        for k, v in info.iteritems():
            print k, v

Code to loop through all records in MS Access

You should be able to do this with a pretty standard DAO recordset loop. You can see some examples at the following links:
http://msdn.microsoft.com/en-us/library/bb243789%28v=office.12%29.aspx
http://www.granite.ab.ca/access/email/recordsetloop.htm

My own standard loop looks something like this:

Dim rs As DAO.Recordset
Set rs = CurrentDb.OpenRecordset("SELECT * FROM Contacts")

'Check to see if the recordset actually contains rows
If Not (rs.EOF And rs.BOF) Then
    rs.MoveFirst 'Unnecessary in this case, but still a good habit
    Do Until rs.EOF = True
        'Perform an edit
        rs.Edit
        rs!VendorYN = True
        rs("VendorYN") = True 'The other way to refer to a field
        rs.Update

        'Save contact name into a variable
        sContactName = rs!FirstName & " " & rs!LastName

        'Move to the next record. Don't ever forget to do this.
        rs.MoveNext
    Loop
Else
    MsgBox "There are no records in the recordset."
End If

MsgBox "Finished looping through records."

rs.Close 'Close the recordset
Set rs = Nothing 'Clean up

CSS float right not working correctly

You have not used float:left command for your text.

getting JRE system library unbound error in build path

oh boy, this got resolved, I just had to name my Installed JRE appropriately. I had only the jdk installed and eclipse had taken the default jdk name, i renamed it to JavaSE-1.6 and voila it worked, though i had to redo everthing from the scratch.

Access denied for user 'root'@'localhost' (using password: YES) after new installation on Ubuntu

The new command to flush the privileges is:

FLUSH PRIVILEGES

The old command FLUSH ALL PRIVILEGES does not work any more.

You will get an error that looks like that:

MariaDB [(none)]> FLUSH ALL PRIVILEGES; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'ALL PRIVILEGES' at line 1

Hope this helps :)

T-SQL Subquery Max(Date) and Joins

Something like this

SELECT * 
FROM MyParts 
LEFT JOIN 
(
SELECT MAX(PriceDate), PartID FROM MyPrice group by PartID
) myprice
 ON MyParts.Partid = MyPrice.Partid 

If you know your partid or can restrict it put it inside the join.

   SELECT myprice.partid, myprice.partdate, myprice2.Price, * 
    FROM MyParts 
    LEFT JOIN 
    (
    SELECT MAX(PriceDate), PartID FROM MyPrice group by PartID
    ) myprice
     ON MyParts.Partid = MyPrice.Partid 
    Inner Join MyPrice myprice2
    on myprice2.pricedate = myprice.pricedate
    and myprice2.partid = myprice.partid

How to get date and time from server

Try this -

<?php
date_default_timezone_set('Asia/Kolkata');

$timestamp = time();
$date_time = date("d-m-Y (D) H:i:s", $timestamp);
echo "Current date and local time on this server is $date_time";
?>

How do you convert a byte array to a hexadecimal string, and vice versa?

    // a safe version of the lookup solution:       

    public static string ByteArrayToHexViaLookup32Safe(byte[] bytes, bool withZeroX)
    {
        if (bytes.Length == 0)
        {
            return withZeroX ? "0x" : "";
        }

        int length = bytes.Length * 2 + (withZeroX ? 2 : 0);
        StateSmall stateToPass = new StateSmall(bytes, withZeroX);
        return string.Create(length, stateToPass, (chars, state) =>
        {
            int offset0x = 0;
            if (state.WithZeroX)
            {
                chars[0] = '0';
                chars[1] = 'x';
                offset0x += 2;
            }

            Span<uint> charsAsInts = MemoryMarshal.Cast<char, uint>(chars.Slice(offset0x));
            int targetLength = state.Bytes.Length;
            for (int i = 0; i < targetLength; i += 1)
            {
                uint val = Lookup32[state.Bytes[i]];
                charsAsInts[i] = val;
            }
        });
    }

    private struct StateSmall
    {
        public StateSmall(byte[] bytes, bool withZeroX)
        {
            Bytes = bytes;
            WithZeroX = withZeroX;
        }

        public byte[] Bytes;
        public bool WithZeroX;
    }

How to get IntPtr from byte[] in C#

In some cases you can use an Int32 type (or Int64) in case of the IntPtr. If you can, another useful class is BitConverter. For what you want you could use BitConverter.ToInt32 for example.

Learning Regular Expressions

The most important part is the concepts. Once you understand how the building blocks work, differences in syntax amount to little more than mild dialects. A layer on top of your regular expression engine's syntax is the syntax of the programming language you're using. Languages such as Perl remove most of this complication, but you'll have to keep in mind other considerations if you're using regular expressions in a C program.

If you think of regular expressions as building blocks that you can mix and match as you please, it helps you learn how to write and debug your own patterns but also how to understand patterns written by others.

Start simple

Conceptually, the simplest regular expressions are literal characters. The pattern N matches the character 'N'.

Regular expressions next to each other match sequences. For example, the pattern Nick matches the sequence 'N' followed by 'i' followed by 'c' followed by 'k'.

If you've ever used grep on Unix—even if only to search for ordinary looking strings—you've already been using regular expressions! (The re in grep refers to regular expressions.)

Order from the menu

Adding just a little complexity, you can match either 'Nick' or 'nick' with the pattern [Nn]ick. The part in square brackets is a character class, which means it matches exactly one of the enclosed characters. You can also use ranges in character classes, so [a-c] matches either 'a' or 'b' or 'c'.

The pattern . is special: rather than matching a literal dot only, it matches any character. It's the same conceptually as the really big character class [-.?+%$A-Za-z0-9...].

Think of character classes as menus: pick just one.

Helpful shortcuts

Using . can save you lots of typing, and there are other shortcuts for common patterns. Say you want to match a digit: one way to write that is [0-9]. Digits are a frequent match target, so you could instead use the shortcut \d. Others are \s (whitespace) and \w (word characters: alphanumerics or underscore).

The uppercased variants are their complements, so \S matches any non-whitespace character, for example.

Once is not enough

From there, you can repeat parts of your pattern with quantifiers. For example, the pattern ab?c matches 'abc' or 'ac' because the ? quantifier makes the subpattern it modifies optional. Other quantifiers are

  • * (zero or more times)
  • + (one or more times)
  • {n} (exactly n times)
  • {n,} (at least n times)
  • {n,m} (at least n times but no more than m times)

Putting some of these blocks together, the pattern [Nn]*ick matches all of

  • ick
  • Nick
  • nick
  • Nnick
  • nNick
  • nnick
  • (and so on)

The first match demonstrates an important lesson: * always succeeds! Any pattern can match zero times.

A few other useful examples:

  • [0-9]+ (and its equivalent \d+) matches any non-negative integer
  • \d{4}-\d{2}-\d{2} matches dates formatted like 2019-01-01

Grouping

A quantifier modifies the pattern to its immediate left. You might expect 0abc+0 to match '0abc0', '0abcabc0', and so forth, but the pattern immediately to the left of the plus quantifier is c. This means 0abc+0 matches '0abc0', '0abcc0', '0abccc0', and so on.

To match one or more sequences of 'abc' with zeros on the ends, use 0(abc)+0. The parentheses denote a subpattern that can be quantified as a unit. It's also common for regular expression engines to save or "capture" the portion of the input text that matches a parenthesized group. Extracting bits this way is much more flexible and less error-prone than counting indices and substr.

Alternation

Earlier, we saw one way to match either 'Nick' or 'nick'. Another is with alternation as in Nick|nick. Remember that alternation includes everything to its left and everything to its right. Use grouping parentheses to limit the scope of |, e.g., (Nick|nick).

For another example, you could equivalently write [a-c] as a|b|c, but this is likely to be suboptimal because many implementations assume alternatives will have lengths greater than 1.

Escaping

Although some characters match themselves, others have special meanings. The pattern \d+ doesn't match backslash followed by lowercase D followed by a plus sign: to get that, we'd use \\d\+. A backslash removes the special meaning from the following character.

Greediness

Regular expression quantifiers are greedy. This means they match as much text as they possibly can while allowing the entire pattern to match successfully.

For example, say the input is

"Hello," she said, "How are you?"

You might expect ".+" to match only 'Hello,' and will then be surprised when you see that it matched from 'Hello' all the way through 'you?'.

To switch from greedy to what you might think of as cautious, add an extra ? to the quantifier. Now you understand how \((.+?)\), the example from your question works. It matches the sequence of a literal left-parenthesis, followed by one or more characters, and terminated by a right-parenthesis.

If your input is '(123) (456)', then the first capture will be '123'. Non-greedy quantifiers want to allow the rest of the pattern to start matching as soon as possible.

(As to your confusion, I don't know of any regular-expression dialect where ((.+?)) would do the same thing. I suspect something got lost in transmission somewhere along the way.)

Anchors

Use the special pattern ^ to match only at the beginning of your input and $ to match only at the end. Making "bookends" with your patterns where you say, "I know what's at the front and back, but give me everything between" is a useful technique.

Say you want to match comments of the form

-- This is a comment --

you'd write ^--\s+(.+)\s+--$.

Build your own

Regular expressions are recursive, so now that you understand these basic rules, you can combine them however you like.

Tools for writing and debugging regexes:

Books

Free resources

Footnote

†: The statement above that . matches any character is a simplification for pedagogical purposes that is not strictly true. Dot matches any character except newline, "\n", but in practice you rarely expect a pattern such as .+ to cross a newline boundary. Perl regexes have a /s switch and Java Pattern.DOTALL, for example, to make . match any character at all. For languages that don't have such a feature, you can use something like [\s\S] to match "any whitespace or any non-whitespace", in other words anything.

iPhone get SSID without private library

If you are running iOS 12 you will need to do an extra step. I've been struggling to make this code work and finally found this on Apple's site: "Important To use this function in iOS 12 and later, enable the Access WiFi Information capability for your app in Xcode. When you enable this capability, Xcode automatically adds the Access WiFi Information entitlement to your entitlements file and App ID." https://developer.apple.com/documentation/systemconfiguration/1614126-cncopycurrentnetworkinfo

How do I make a placeholder for a 'select' box?

The solution below works in Firefox also, without any JavaScript:

_x000D_
_x000D_
option[default] {_x000D_
  display: none;_x000D_
}
_x000D_
<select>_x000D_
  <option value="" default selected>Select Your Age</option>_x000D_
  <option value="1">1</option>_x000D_
  <option value="2">2</option>_x000D_
  <option value="3">3</option>_x000D_
  <option value="4">4</option>_x000D_
</select>
_x000D_
_x000D_
_x000D_

Convert time fields to strings in Excel

If you want to show those number values as a time then change the format of the cell to Time.

And if you want to transform it to a text in another cell:

=TEXT(A1,"hh:mm:ss")

How to change options of <select> with jQuery?

Does this help?

$("#SelectName option[value='theValueOfOption']")[0].selected = true;

Spark DataFrame groupBy and sort in the descending order (pyspark)

In PySpark 1.3 sort method doesn't take ascending parameter. You can use desc method instead:

from pyspark.sql.functions import col

(group_by_dataframe
    .count()
    .filter("`count` >= 10")
    .sort(col("count").desc()))

or desc function:

from pyspark.sql.functions import desc

(group_by_dataframe
    .count()
    .filter("`count` >= 10")
    .sort(desc("count"))

Both methods can be used with with Spark >= 1.3 (including Spark 2.x).

How to disable text selection highlighting

This will be useful if color selection is also not needed:

::-moz-selection { background:none; color:none; }
::selection { background:none; color:none; }

...all other browser fixes. It will work in Internet Explorer 9 or later.

In an array of objects, fastest way to find the index of an object whose attributes match a search

array.forEach(function (elem, i) {  // iterate over all elements of array
    indexes[elem.id] = i;           // take the found id as index for the
});                                 // indexes array and assign i

the result is a look up list for the id. with the given id we get the index of the record.

Get the current URL with JavaScript?

Use window.location for read and write access to the location object associated with the current frame. If you just want to get the address as a read-only string, you may use document.URL, which should contain the same value as window.location.href.

Is it possible to animate scrollTop with jQuery?

If you want to move down at the end of the page (so you don't need to scroll down to bottom) , you can use:

$('body').animate({ scrollTop: $(document).height() });

sed edit file in place

Like Moneypenny said in Skyfall: "Sometimes the old ways are best." Kincade said something similar later on.

$ printf ',s/false/true/g\nw\n' | ed {YourFileHere}

Happy editing in place. Added '\nw\n' to write the file. Apologies for delay answering request.

How to retrieve all keys (or values) from a std::map and put them into a vector?

Here's a nice function template using C++11 magic, working for both std::map, std::unordered_map:

template<template <typename...> class MAP, class KEY, class VALUE>
std::vector<KEY>
keys(const MAP<KEY, VALUE>& map)
{
    std::vector<KEY> result;
    result.reserve(map.size());
    for(const auto& it : map){
        result.emplace_back(it.first);
    }
    return result;
}

Check it out here: http://ideone.com/lYBzpL

Passing multiple parameters with $.ajax url

why not just pass an data an object with your key/value pairs then you don't have to worry about encoding

$.ajax({
    type: "Post",
    url: "getdata.php",
    data:{
       timestamp: timestamp,
       uid: id,
       uname: name
    },
    async: true,
    cache: false,
    success: function(data) {


    };
}?);?

HQL Hibernate INNER JOIN

Joins can only be used when there is an association between entities. Your Employee entity should not have a field named id_team, of type int, mapped to a column. It should have a ManyToOne association with the Team entity, mapped as a JoinColumn:

@ManyToOne
@JoinColumn(name="ID_TEAM")
private Team team;

Then, the following query will work flawlessly:

select e from Employee e inner join e.team

Which will load all the employees, except those that aren't associated to any team.

The same goes for all the other fields which are a foreign key to some other table mapped as an entity, of course (id_boss, id_profession).

It's time for you to read the Hibernate documentation, because you missed an extremely important part of what it is and how it works.

Pycharm does not show plot

I'm using Ubuntu and I tried as @Arie said above but with this line only in terminal:

sudo apt-get install tcl-dev tk-dev python-tk python3-tk

And it worked!

Parsing PDF files (especially with tables) with PDFBox

How about printing to image and doing OCR on that?

Sounds terribly ineffective, but it's practically the very purpose of PDF to make text inaccessible, you gotta do what you gotta do.

How can I convert this one line of ActionScript to C#?

There is collection of Func<...> classes - Func that is probably what you are looking for:

 void MyMethod(Func<int> param1 = null) 

This defines method that have parameter param1 with default value null (similar to AS), and a function that returns int. Unlike AS in C# you need to specify type of the function's arguments.

So if you AS usage was

MyMethod(function(intArg, stringArg) { return true; }) 

Than in C# it would require param1 to be of type Func<int, siring, bool> and usage like

MyMethod( (intArg, stringArg) => { return true;} ); 

Custom Cell Row Height setting in storyboard is not responding

I've built the code the various answers/comments hint at so that this works for storyboards that use prototype cells.

This code:

  • Does not require the cell height to be set anywhere other than the obvious place in the storyboard
  • Caches the height for performance reasons
  • Uses a common function to get the cell identifier for an index path to avoid duplicated logic

Thanks to Answerbot, Brennan and lensovet.

- (NSString *)cellIdentifierForIndexPath:(NSIndexPath *)indexPath
{
    NSString *cellIdentifier = nil;

    switch (indexPath.section)
    {
        case 0:
            cellIdentifier = @"ArtworkCell";
            break;
         <... and so on ...>
    }

    return cellIdentifier;
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSString *cellIdentifier = [self cellIdentifierForIndexPath:indexPath];
    static NSMutableDictionary *heightCache;
    if (!heightCache)
        heightCache = [[NSMutableDictionary alloc] init];
    NSNumber *cachedHeight = heightCache[cellIdentifier];
    if (cachedHeight)
        return cachedHeight.floatValue;

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
    CGFloat height = cell.bounds.size.height;
    heightCache[cellIdentifier] = @(height);
    return height;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSString *cellIdentifier = [self cellIdentifierForIndexPath:indexPath];

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier forIndexPath:indexPath];

    <... configure cell as usual...>

How to set a default entity property value with Hibernate

If you want to set default value in terms of database, just set @Column( columnDefinition = "int default 1")

But if what you intend is to set a default value in your java app you can set it on your class attribute like this: private Integer attribute = 1;

Creating a data frame from two vectors using cbind

Using data.frame instead of cbind should be helpful

x <- data.frame(col1=c(10, 20), col2=c("[]", "[]"), col3=c("[[1,2]]","[[1,3]]"))
x
  col1 col2    col3
1   10   [] [[1,2]]
2   20   [] [[1,3]]

sapply(x, class) # looking into x to see the class of each element
     col1      col2      col3 
"numeric"  "factor"  "factor" 

As you can see elements from col1 are numeric as you wish.

data.frame can have variables of different class: numeric, factor and character but matrix doesn't, once you put a character element into a matrix all the other will become into this class no matter what clase they were before.

How do you redirect to a page using the POST verb?

If you want to pass data between two actions during a redirect without include any data in the query string, put the model in the TempData object.

ACTION

TempData["datacontainer"] = modelData;

VIEW

var modelData= TempData["datacontainer"] as ModelDataType; 

TempData is meant to be a very short-lived instance, and you should only use it during the current and the subsequent requests only! Since TempData works this way, you need to know for sure what the next request will be, and redirecting to another view is the only time you can guarantee this.

Therefore, the only scenario where using TempData will reliably work is when you are redirecting.

oracle sql: update if exists else insert

The way I always do it (assuming the data is never to be deleted, only inserted) is to

  • Firstly do an insert, if this fails with a unique constraint violation then you know the row is there,
  • Then do an update

Unfortunately many frameworks such as Hibernate treat all database errors (e.g. unique constraint violation) as unrecoverable conditions, so it isn't always easy. (In Hibernate the solution is to open a new session/transaction just to execute this one insert command.)

You can't just do a select count(*) .. where .. as even if that returns zero, and therefore you choose to do an insert, between the time you do the select and the insert someone else might have inserted the row and therefore your insert will fail.

The FastCGI process exited unexpectedly

if you have two application like (your app, phpmyadmin) just disable APC extension Hope that fix that issue it's worked with me

How to get the file ID so I can perform a download of a file from Google Drive API on Android?

Stan0 intial idea is not a good idea. There can be multiple files with the same name. Very error prone implementation. Stan0's second idea is the correct way.

When you first upload the file to google drive store its id (in SharedPreferences is probably easiest) for later use

ie.

file= mDrive.files().insert(body).execute();      //initial insert of file to google drive

whereverYouWantToStoreIt= file.getId(); //now you have the guaranteed unique id 
                                        //of the file just inserted. Store it and use it 
                                        //whenever you need to fetch this file

How to add additional fields to form before submit?

$('#form').append('<input type="text" value="'+yourValue+'" />');

Javascript checkbox onChange

Reference the checkbox by it's id and not with the # Assign the function to the onclick attribute rather than using the change attribute

var checkbox = $("save_" + fieldName);
checkbox.onclick = function(event) {
    var checkbox = event.target;

    if (checkbox.checked) {
        //Checkbox has been checked
    } else {
        //Checkbox has been unchecked
    }
};

How do I include a file over 2 directories back?

if you are using php7 you can use dirname function with level parameter of 2, for example :

dirname("/usr/local/lib", 2);

the second parameter "2" indicate how many level up

dirname referance

center aligning a fixed position div

<div class="container-div">
  <div class="center-div">

  </div>
</div>

.container-div {position:fixed; left: 0; bottom: 0; width: 100%; margin: 0;}
.center-div {width: 200px; margin: 0 auto;}

This should do the same.

Filter rows which contain a certain string

Solution

It is possible to use str_detect of the stringr package included in the tidyverse package. str_detect returns True or False as to whether the specified vector contains some specific string. It is possible to filter using this boolean value. See Introduction to stringr for details about stringr package.

library(tidyverse)
# - Attaching packages -------------------- tidyverse 1.2.1 -
# ? ggplot2 2.2.1     ? purrr   0.2.4
# ? tibble  1.4.2     ? dplyr   0.7.4
# ? tidyr   0.7.2     ? stringr 1.2.0
# ? readr   1.1.1     ? forcats 0.3.0
# - Conflicts --------------------- tidyverse_conflicts() -
# ? dplyr::filter() masks stats::filter()
# ? dplyr::lag()    masks stats::lag()

mtcars$type <- rownames(mtcars)
mtcars %>%
  filter(str_detect(type, 'Toyota|Mazda'))
# mpg cyl  disp  hp drat    wt  qsec vs am gear carb           type
# 1 21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4      Mazda RX4
# 2 21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4  Mazda RX4 Wag
# 3 33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1 Toyota Corolla
# 4 21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1  Toyota Corona

The good things about Stringr

We should use rather stringr::str_detect() than base::grepl(). This is because there are the following reasons.

  • The functions provided by the stringr package start with the prefix str_, which makes the code easier to read.
  • The first argument of the functions of stringr package is always the data.frame (or value), then comes the parameters.(Thank you Paolo)
object <- "stringr"
# The functions with the same prefix `str_`.
# The first argument is an object.
stringr::str_count(object) # -> 7
stringr::str_sub(object, 1, 3) # -> "str"
stringr::str_detect(object, "str") # -> TRUE
stringr::str_replace(object, "str", "") # -> "ingr"
# The function names without common points.
# The position of the argument of the object also does not match.
base::nchar(object) # -> 7
base::substr(object, 1, 3) # -> "str"
base::grepl("str", object) # -> TRUE
base::sub("str", "", object) # -> "ingr"

Benchmark

The results of the benchmark test are as follows. For large dataframe, str_detect is faster.

library(rbenchmark)
library(tidyverse)

# The data. Data expo 09. ASA Statistics Computing and Graphics 
# http://stat-computing.org/dataexpo/2009/the-data.html
df <- read_csv("Downloads/2008.csv")
print(dim(df))
# [1] 7009728      29

benchmark(
  "str_detect" = {df %>% filter(str_detect(Dest, 'MCO|BWI'))},
  "grepl" = {df %>% filter(grepl('MCO|BWI', Dest))},
  replications = 10,
  columns = c("test", "replications", "elapsed", "relative", "user.self", "sys.self"))
# test replications elapsed relative user.self sys.self
# 2      grepl           10  16.480    1.513    16.195    0.248
# 1 str_detect           10  10.891    1.000     9.594    1.281

Validating file types by regular expression

^.+\.(?:(?:[dD][oO][cC][xX]?)|(?:[pP][dD][fF]))$

Will accept .doc, .docx, .pdf files having a filename of at least one character:

^           = beginning of string
.+          = at least one character (any character)
\.          = dot ('.')
(?:pattern) = match the pattern without storing the match)
[dD]        = any character in the set ('d' or 'D')
[xX]?       = any character in the set or none 
              ('x' may be missing so 'doc' or 'docx' are both accepted)
|           = either the previous or the next pattern
$           = end of matched string

Warning! Without enclosing the whole chain of extensions in (?:), an extension like .docpdf would pass.

You can test regular expressions at http://www.regextester.com/

Retrieve Button value with jQuery

if you want to get the value attribute (buttonValue) then I'd use:

<script type="text/javascript">
    $(document).ready(function() {
        $('.my_button').click(function() {
            alert($(this).attr('value'));
        });
    });
</script>

Can I mask an input text in a bat file?

I used Blorgbeard's above solution which is actually great in my opinion. Then I enhanced it as follows:

  1. Google for ansicon
  2. Download zip file and sample text file.
  3. Install (that means copy 2 files into system32)

Use it like this:

@echo off
ansicon -p
set /p pwd=Password:ESC[0;37;47m
echo ESC[0m

This switches the console to gray on gray for your password entry and switches back when you are done. The ESC should actually be an unprintable character, which you can copy over from the downloaded sample text file (appears like a left-arrow in Notepad) into your batch file. You can use the sample text file to find the codes for all color combinations.

If you are not admin of the machine, you will probably be able to install the files in a non-system directory, then you have to append the directory to the PATH in your script before calling the program and using the escape sequences. This could even be the current directory probably, if you need a non-admin distributable package of just a few files.

Setting and getting localStorage with jQuery

The localStorage can only store string content and you are trying to store a jQuery object since html(htmlString) returns a jQuery object.

You need to set the string content instead of an object. And use the setItem method to add data and getItem to get data.

window.localStorage.setItem('content', 'Test');
$('#test').html(window.localStorage.getItem('content'));

How to set a Postgresql default value datestamp like 'YYYYMM'?

Thanks for everyone who answered, and thanks for those who gave me the function-format idea, i'll really study it for future using.

But for this explicit case, the 'special yyyymm field' is not to be considered as a date field, but just as a tag, o whatever would be used for matching the exactly year-month researched value; there is already another date field, with the full timestamp, but if i need all the rows of january 2008, i think that is faster a select like

SELECT  [columns] FROM table WHERE yearmonth = '200801'

instead of

SELECT  [columns] FROM table WHERE date BETWEEN DATE('2008-01-01') AND DATE('2008-01-31')

Download TS files from video stream

I needed to download HLS video and audio streams from a e-learning portal with session-protected content with application/mp2t MIME content type.

Manually copying all authentication headers into the downloading scripts would be too cumbersome.

But the task got much easier with help of Video DownloadHelper Firefox extension and it's Companion App. It allowed to download both m3u8 playlists with TS chunks lists and actual video and audio streams into mp4 files via a click of button while correctly preserving authentication headers.

The resulting separate video and audio files can be merged with ffmpeg:

ffmpeg -i video.mp4 -i audio.mp4 -acodec copy -vcodec copy video-and-audio.mp4 

or with mp4box:

mp4box -add audio.mp4#audio video.mp4 -out video-and-audio.mp4

Tried Video DownloadHelper Chrome extension too, but it didn't work for me.

SSIS Convert Between Unicode and Non-Unicode Error

Below Steps worked for me:

1). right click on source task.

2). click on "Show Advanced editor". advanced edit option for source task in ssis

3). Go to "Input and Output Properties" tab.

4). select the output column for which you are getting the error.

5). Its data type will be "String[DT_STR]".

6). Change that data type to "Unicode String[DT_WSTR]". Changing the data type to unicode string

7). save and close. Hope this helps!

How to read a text file into a list or an array with Python

This question is asking how to read the comma-separated value contents from a file into an iterable list:

0,0,200,0,53,1,0,255,...,0.

The easiest way to do this is with the csv module as follows:

import csv
with open('filename.dat', newline='') as csvfile:
    spamreader = csv.reader(csvfile, delimiter=',')

Now, you can easily iterate over spamreader like this:

for row in spamreader:
    print(', '.join(row))

See documentation for more examples.

Uncaught ReferenceError: angular is not defined - AngularJS not working

Just to complement m59's correct answer, here is a working jsfiddle:

<body ng-app='myApp'>
    <div>
        <button my-directive>Click Me!</button>
    </div>
     <h1>{{2+3}}</h1>

</body>

Difference between map, applymap and apply methods in Pandas

Adding to the other answers, in a Series there are also map and apply.

Apply can make a DataFrame out of a series; however, map will just put a series in every cell of another series, which is probably not what you want.

In [40]: p=pd.Series([1,2,3])
In [41]: p
Out[31]:
0    1
1    2
2    3
dtype: int64

In [42]: p.apply(lambda x: pd.Series([x, x]))
Out[42]: 
   0  1
0  1  1
1  2  2
2  3  3

In [43]: p.map(lambda x: pd.Series([x, x]))
Out[43]: 
0    0    1
1    1
dtype: int64
1    0    2
1    2
dtype: int64
2    0    3
1    3
dtype: int64
dtype: object

Also if I had a function with side effects, such as "connect to a web server", I'd probably use apply just for the sake of clarity.

series.apply(download_file_for_every_element) 

Map can use not only a function, but also a dictionary or another series. Let's say you want to manipulate permutations.

Take

1 2 3 4 5
2 1 4 5 3

The square of this permutation is

1 2 3 4 5
1 2 5 3 4

You can compute it using map. Not sure if self-application is documented, but it works in 0.15.1.

In [39]: p=pd.Series([1,0,3,4,2])

In [40]: p.map(p)
Out[40]: 
0    0
1    1
2    4
3    2
4    3
dtype: int64

SQL Server Management Studio alternatives to browse/edit tables and run queries

If you are already spending time in Visual Studio, then you can always use the Server Explorer to connect to any .Net compliant database server.

Provided you're using Professional or greater, you can create and edit tables and databases, run queries, etc.

MySQL - how to front pad zip code with "0"?

Store your zipcodes as CHAR(5) instead of a numeric type, or have your application pad it with zeroes when you load it from the DB. A way to do it with PHP using sprintf():

echo sprintf("%05d", 205); // prints 00205
echo sprintf("%05d", 1492); // prints 01492

Or you could have MySQL pad it for you with LPAD():

SELECT LPAD(zip, 5, '0') as zipcode FROM table;

Here's a way to update and pad all rows:

ALTER TABLE `table` CHANGE `zip` `zip` CHAR(5); #changes type
UPDATE table SET `zip`=LPAD(`zip`, 5, '0'); #pads everything

Save file Javascript with file name

function saveAs(uri, filename) {
    var link = document.createElement('a');
    if (typeof link.download === 'string') {
        document.body.appendChild(link); // Firefox requires the link to be in the body
        link.download = filename;
        link.href = uri;
        link.click();
        document.body.removeChild(link); // remove the link when done
    } else {
        location.replace(uri);
    }
}

How to get all Errors from ASP.Net MVC modelState?

For just in case someone need it i made and use the following static class in my projects

Usage example:

if (!ModelState.IsValid)
{
    var errors = ModelState.GetModelErrors();
    return Json(new { errors });
}

Usings:

using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web.Mvc;
using WebGrease.Css.Extensions;

Class:

public static class ModelStateErrorHandler
{
    /// <summary>
    /// Returns a Key/Value pair with all the errors in the model
    /// according to the data annotation properties.
    /// </summary>
    /// <param name="errDictionary"></param>
    /// <returns>
    /// Key: Name of the property
    /// Value: The error message returned from data annotation
    /// </returns>
    public static Dictionary<string, string> GetModelErrors(this ModelStateDictionary errDictionary)
    {
        var errors = new Dictionary<string, string>();
        errDictionary.Where(k => k.Value.Errors.Count > 0).ForEach(i =>
        {
            var er = string.Join(", ", i.Value.Errors.Select(e => e.ErrorMessage).ToArray());
            errors.Add(i.Key, er);
        });
        return errors;
    }

    public static string StringifyModelErrors(this ModelStateDictionary errDictionary)
    {
        var errorsBuilder = new StringBuilder();
        var errors = errDictionary.GetModelErrors();
        errors.ForEach(key => errorsBuilder.AppendFormat("{0}: {1} -", key.Key,key.Value));
        return errorsBuilder.ToString();
    }
}

Batch file. Delete all files and folders in a directory

IF EXIST "C:\Users\tbrollo\j2mewtk\2.5.2\appdb\RMS" (
    rmdir "C:\Users\tbrollo\j2mewtk\2.5.2\appdb\RMS" /s /q
)

This will delete everything from the folder (and the folder itself).

How to turn off page breaks in Google Docs?

The solution I came up with was to use the publishing feature.

File > Publish to the web...

Then in the URL you can just replace the .../edit path with .../pub

This solves the problem described in the question of breaking up a table with footnotes.

Disable validation of HTML5 form elements

I just wanted to add that using the novalidate attribute in your form will only prevent the browser from sending the form. The browser still evaluates the data and adds the :valid and :invalid pseudo classes.

I found this out because the valid and invalid pseudo classes are part of the HTML5 boilerplate stylesheet which I have been using. I just removed the entries in the CSS file that related to the pseudo classes. If anyone finds another solution please let me know.

Difference between <context:annotation-config> and <context:component-scan>

<context:component-scan base-package="package name" />:

This is used to tell the container that there are bean classes in my package scan those bean classes. In order to scan bean classes by container on top of the bean we have to write one of the stereo type annotation like following.

@Component, @Service, @Repository, @Controller

<context:annotation-config />:

If we don't want to write bean tag explicitly in XML then how the container knows if there is a auto wiring in the bean. This is possible by using @Autowired annotation. we have to inform to the container that there is auto wiring in my bean by context:annotation-config.

Could not load file or assembly 'Microsoft.ReportViewer.WebForms'

I ran into the same error. My web app was pointed towards report viewer version 10.0 however if 11.0 is installed it adds a redirect in the 10.0 .dll to 11.0. This became an issue when 11.0 was uninstalled as this does not correct the redirect in the 10.0 .dll. The fix in my case was to simply uninstall and reinstall 10.0.

Which header file do you include to use bool type in c in linux?

#include <stdbool.h>

For someone like me here to copy and paste.

Symfony 2 EntityManager injection in service

Since 2017 and Symfony 3.3 you can register Repository as service, with all its advantages it has.

Check my post How to use Repository with Doctrine as Service in Symfony for more general description.


To your specific case, original code with tuning would look like this:

1. Use in your services or Controller

<?php

namespace Test\CommonBundle\Services;

use Doctrine\ORM\EntityManagerInterface;

class UserService
{
    private $userRepository;

    // use custom repository over direct use of EntityManager
    // see step 2
    public function __constructor(UserRepository $userRepository)
    {
        $this->userRepository = $userRepository;
    }

    public function getUser($userId)
    {
        return $this->userRepository->find($userId);
    }
}

2. Create new custom repository

<?php

namespace Test\CommonBundle\Repository;

use Doctrine\ORM\EntityManagerInterface;

class UserRepository
{
    private $repository;

    public function __construct(EntityManagerInterface $entityManager)
    {
        $this->repository = $entityManager->getRepository(UserEntity::class);
    }

    public function find($userId)
    {
        return  $this->repository->find($userId);
    }
}

3. Register services

# app/config/services.yml
services:
    _defaults:
        autowire: true

    Test\CommonBundle\:
       resource: ../../Test/CommonBundle

Undo a Git merge that hasn't been pushed yet

If you committed the merge:

git reset HEAD~1
# Make sure what you are reverting is in fact the merge files
git add .
git reset --hard

Mac OS X and multiple Java versions

In the same spirit than @Vegard (lightweight):

  • Install the wanted JDKs with Homebrew
  • Put this jdk bash function and a default in your .profile

    jdk() {
        version=$1
        export JAVA_HOME=$(/usr/libexec/java_home -v"$version");
        java -version
     }
    
    export JAVA_HOME=$(/usr/libexec/java_home -v11); # Your default version
    
  • and then, to switch your jdk, you can do

     jdk 9
     jdk 11
     jdk 13
    

Based on https://github.com/AdoptOpenJDK/homebrew-openjdk.

How can I have grep not print out 'No such file or directory' errors?

I have seen that happening several times, with broken links (symlinks that point to files that do not exist), grep tries to search on the target file, which does not exist (hence the correct and accurate error message).

I normally don't bother while doing sysadmin tasks over the console, but from within scripts I do look for text files with "find", and then grep each one:

find /etc -type f -exec grep -nHi -e "widehat" {} \;

Instead of:

grep -nRHi -e "widehat" /etc

Left join only selected columns in R with the merge() function

Nothing elegant but this could be another satisfactory answer.

merge(x = DF1, y = DF2, by = "Client", all.x=TRUE)[,c("Client","LO","CON")]

This will be useful especially when you don't need the keys that were used to join the tables in your results.

Does java have a int.tryparse that doesn't throw an exception for bad data?

No. You have to make your own like this:

boolean tryParseInt(String value) {  
     try {  
         Integer.parseInt(value);  
         return true;  
      } catch (NumberFormatException e) {  
         return false;  
      }  
}

...and you can use it like this:

if (tryParseInt(input)) {  
   Integer.parseInt(input);  // We now know that it's safe to parse
}

EDIT (Based on the comment by @Erk)

Something like follows should be better

public int tryParse(String value, int defaultVal) {
    try {
        return Integer.parseInt(value);
    } catch (NumberFormatException e) {
        return defaultVal;
    }
}

When you overload this with a single string parameter method, it would be even better, which will enable using with the default value being optional.

public int tryParse(String value) {
    return tryParse(value, 0)
}

Difference between "enqueue" and "dequeue"

These are terms usually used when describing a "FIFO" queue, that is "first in, first out". This works like a line. You decide to go to the movies. There is a long line to buy tickets, you decide to get into the queue to buy tickets, that is "Enqueue". at some point you are at the front of the line, and you get to buy a ticket, at which point you leave the line, that is "Dequeue".

Integration Testing POSTing an entire object to Spring MVC controller

One of the main purposes of integration testing with MockMvc is to verify that model objects are correclty populated with form data.

In order to do it you have to pass form data as they're passed from actual form (using .param()). If you use some automatic conversion from NewObject to from data, your test won't cover particular class of possible problems (modifications of NewObject incompatible with actual form).

Is there an opposite to display:none?

Like Paul explains there is no literal opposite of display: none in HTML as each element has a different default display and you can also change the display with a class or inline style etc.

However if you use something like jQuery, their show and hide functions behave as if there was an opposite of display none. When you hide, and then show an element again, it will display in exactly the same manner it did before it was hidden. They do this by storing the old value of the display property on hiding of the element so that when you show it again it will display in the same way it did before you hid it. https://github.com/jquery/jquery/blob/740e190223d19a114d5373758127285d14d6b71e/src/css.js#L180

This means that if you set a div for example to display inline, or inline-block and you hide it and then show it again, it will once again show as display inline or inline-block same as it was before

<div style="display:inline" >hello</div>
<div style="display:inline-block">hello2</div>
<div style="display:table-cell" >hello3</div>

script:

  $('a').click(function(){
        $('div').toggle();
    });

Notice that the display property of the div will remain constant even after it was hidden (display:none) and shown again.

Is Java's assertEquals method reliable?

You should always use .equals() when comparing Strings in Java.

JUnit calls the .equals() method to determine equality in the method assertEquals(Object o1, Object o2).

So, you are definitely safe using assertEquals(string1, string2). (Because Strings are Objects)

Here is a link to a great Stackoverflow question regarding some of the differences between == and .equals().

How do you auto format code in Visual Studio?

In VS 2017 and 2019

Format Document is CTRL E + D.

But...if you want to add the Format Document button to a tool bar do this.
Right click on tool bar.
Select "Customize.."
Select the "Commands" Tab.
Select the "Toolbar" radio button.
Select "Text Editor" from the pull down next to the radio button (or what ever tool bar you want the botton on)

Now...

Click the Add Command button.
Categories: Edit
Commands: Document Format
Click OK

How can I get an HTTP response body as a string?

How about just this?

org.apache.commons.io.IOUtils.toString(new URL("http://www.someurl.com/"));