Programs & Examples On #Jsonreader

Error reading JObject from JsonReader. Current JsonReader item is not an object: StartArray. Path

In this case that you know that you have all items in the first place on array you can parse the string to JArray and then parse the first item using JObject.Parse

var  jsonArrayString = @"
[
  {
    ""country"": ""India"",
    ""city"": ""Mall Road, Gurgaon"",
  },
  {
    ""country"": ""India"",
    ""city"": ""Mall Road, Kanpur"",
  }
]";
JArray jsonArray = JArray.Parse(jsonArrayString);
dynamic data = JObject.Parse(jsonArray[0].ToString());

how to parse JSON file with GSON

just parse as an array:

Review[] reviews = new Gson().fromJson(jsonString, Review[].class);

then if you need you can also create a list in this way:

List<Review> asList = Arrays.asList(reviews);

P.S. your json string should be look like this:

[
    {
        "reviewerID": "A2SUAM1J3GNN3B1",
        "asin": "0000013714",
        "reviewerName": "J. McDonald",
        "helpful": [2, 3],
        "reviewText": "I bought this for my husband who plays the piano.",
        "overall": 5.0,
        "summary": "Heavenly Highway Hymns",
        "unixReviewTime": 1252800000,
        "reviewTime": "09 13, 2009"
    },
    {
        "reviewerID": "A2SUAM1J3GNN3B2",
        "asin": "0000013714",
        "reviewerName": "J. McDonald",
        "helpful": [2, 3],
        "reviewText": "I bought this for my husband who plays the piano.",
        "overall": 5.0,
        "summary": "Heavenly Highway Hymns",
        "unixReviewTime": 1252800000,
        "reviewTime": "09 13, 2009"
    },

    [...]
]

NewtonSoft.Json Serialize and Deserialize class with property of type IEnumerable<ISomeInterface>

I solved that problem by using a special setting for JsonSerializerSettings which is called TypeNameHandling.All

TypeNameHandling setting includes type information when serializing JSON and read type information so that the create types are created when deserializing JSON

Serialization:

var settings = new JsonSerializerSettings { TypeNameHandling = TypeNameHandling.All };
var text = JsonConvert.SerializeObject(configuration, settings);

Deserialization:

var settings = new JsonSerializerSettings { TypeNameHandling = TypeNameHandling.All };
var configuration = JsonConvert.DeserializeObject<YourClass>(json, settings);

The class YourClass might have any kind of base type fields and it will be serialized properly.

Aren't promises just callbacks?

Yes, Promises are asynchronous callbacks. They can't do anything that callbacks can't do, and you face the same problems with asynchrony as with plain callbacks.

However, Promises are more than just callbacks. They are a very mighty abstraction, allow cleaner and better, functional code with less error-prone boilerplate.

So what's the main idea?

Promises are objects representing the result of a single (asynchronous) computation. They resolve to that result only once. There's a few things what this means:

Promises implement an observer pattern:

  • You don't need to know the callbacks that will use the value before the task completes.
  • Instead of expecting callbacks as arguments to your functions, you can easily return a Promise object
  • The promise will store the value, and you can transparently add a callback whenever you want. It will be called when the result is available. "Transparency" implies that when you have a promise and add a callback to it, it doesn't make a difference to your code whether the result has arrived yet - the API and contracts are the same, simplifying caching/memoisation a lot.
  • You can add multiple callbacks easily

Promises are chainable (monadic, if you want):

  • If you need to transform the value that a promise represents, you map a transform function over the promise and get back a new promise that represents the transformed result. You cannot synchronously get the value to use it somehow, but you can easily lift the transformation in the promise context. No boilerplate callbacks.
  • If you want to chain two asynchronous tasks, you can use the .then() method. It will take a callback to be called with the first result, and returns a promise for the result of the promise that the callback returns.

Sounds complicated? Time for a code example.

var p1 = api1(); // returning a promise
var p3 = p1.then(function(api1Result) {
    var p2 = api2(); // returning a promise
    return p2; // The result of p2 …
}); // … becomes the result of p3

// So it does not make a difference whether you write
api1().then(function(api1Result) {
    return api2().then(console.log)
})
// or the flattened version
api1().then(function(api1Result) {
    return api2();
}).then(console.log)

Flattening does not come magically, but you can easily do it. For your heavily nested example, the (near) equivalent would be

api1().then(api2).then(api3).then(/* do-work-callback */);

If seeing the code of these methods helps understanding, here's a most basic promise lib in a few lines.

What's the big fuss about promises?

The Promise abstraction allows much better composability of functions. For example, next to then for chaining, the all function creates a promise for the combined result of multiple parallel-waiting promises.

Last but not least Promises come with integrated error handling. The result of the computation might be that either the promise is fulfilled with a value, or it is rejected with a reason. All the composition functions handle this automatically and propagate errors in promise chains, so that you don't need to care about it explicitly everywhere - in contrast to a plain-callback implementation. In the end, you can add a dedicated error callback for all occurred exceptions.

Not to mention having to convert things to promises.

That's quite trivial actually with good promise libraries, see How do I convert an existing callback API to promises?

Changing java platform on which netbeans runs

For anyone on Mac OS X, you can find netbeans.conf here:

/Applications/NetBeans/NetBeans <version>.app/Contents/Resources/NetBeans/etc/netbeans.conf

In case anyone needs to know :)

Regular expressions in C: examples?

It's probably not what you want, but a tool like re2c can compile POSIX(-ish) regular expressions to ANSI C. It's written as a replacement for lex, but this approach allows you to sacrifice flexibility and legibility for the last bit of speed, if you really need it.

removing bold styling from part of a header

You could wrap the not-bold text into a span and give the span the following properties:

.notbold{
    font-weight:normal
}?

and

<h1>**This text should be bold**, <span class='notbold'>but this text should not</span></h1>

See: http://jsfiddle.net/MRcpa/1/

Use <span> when you want to change the style of elements without placing them in a new block-level element in the document.

Remove HTML tags from a String

Another way is to use javax.swing.text.html.HTMLEditorKit to extract the text.

import java.io.*;
import javax.swing.text.html.*;
import javax.swing.text.html.parser.*;

public class Html2Text extends HTMLEditorKit.ParserCallback {
    StringBuffer s;

    public Html2Text() {
    }

    public void parse(Reader in) throws IOException {
        s = new StringBuffer();
        ParserDelegator delegator = new ParserDelegator();
        // the third parameter is TRUE to ignore charset directive
        delegator.parse(in, this, Boolean.TRUE);
    }

    public void handleText(char[] text, int pos) {
        s.append(text);
    }

    public String getText() {
        return s.toString();
    }

    public static void main(String[] args) {
        try {
            // the HTML to convert
            FileReader in = new FileReader("java-new.html");
            Html2Text parser = new Html2Text();
            parser.parse(in);
            in.close();
            System.out.println(parser.getText());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

ref : Remove HTML tags from a file to extract only the TEXT

add new element in laravel collection object

If you want to add item to the beginning of the collection you can use prepend:

$item->prepend($product, 'key');

SELECT CASE WHEN THEN (SELECT)

For a start the first select has 6 columns and the second has 4 columns. Perhaps make both have the same number of columns (adding nulls?).

Replace only some groups with Regex

Here is another nice clean option that does not require changing your pattern.

        var text = "example-123-example";
        var pattern = @"-(\d+)-";

        var replaced = Regex.Replace(text, pattern, (_match) =>
        {
            Group group = _match.Groups[1];
            string replace = "AA";
            return String.Format("{0}{1}{2}", _match.Value.Substring(0, group.Index - _match.Index), replace, _match.Value.Substring(group.Index - _match.Index + group.Length));
        });

What is the difference between cache and persist?

Spark gives 5 types of Storage level

  • MEMORY_ONLY
  • MEMORY_ONLY_SER
  • MEMORY_AND_DISK
  • MEMORY_AND_DISK_SER
  • DISK_ONLY

cache() will use MEMORY_ONLY. If you want to use something else, use persist(StorageLevel.<*type*>).

By default persist() will store the data in the JVM heap as unserialized objects.

Concatenate chars to form String in java

Use the Character.toString(char) method.

Arguments to main in C

Imagine it this way

*main() is also a function which is called by something else (like another FunctioN)

*the arguments to it is decided by the FunctioN

*the second argument is an array of strings

*the first argument is a number representing the number of strings

*do something with the strings

Maybe a example program woluld help.

int main(int argc,char *argv[])
{

    printf("you entered in reverse order:\n");

    while(argc--)
    {
        printf("%s\n",argv[argc]);
    }

return 0;
}

it just prints everything you enter as args in reverse order but YOU should make new programs that do something more useful.

compile it (as say hello) run it from the terminal with the arguments like

./hello am i here

then try to modify it so that it tries to check if two strings are reverses of each other or not then you will need to check if argc parameter is exactly three if anything else print an error

if(argc!=3)/*3 because even the executables name string is on argc*/
{
    printf("unexpected number of arguments\n");
    return -1;
}

then check if argv[2] is the reverse of argv[1] and print the result

./hello asdf fdsa

should output

they are exact reverses of each other

the best example is a file copy program try it it's like cp

cp file1 file2

cp is the first argument (argv[0] not argv[1]) and mostly you should ignore the first argument unless you need to reference or something

if you made the cp program you understood the main args really...

Installing MySQL in Docker fails with error message "Can't connect to local MySQL server through socket"

Check out what's in your database.yml file. If you already have your plain Rails app and simply wrapping it with Docker, you should change (inside database.yml):

socket: /var/run/mysqld/mysqld.sock #just comment it out

to

host: db 

where db is the name of my db-service from docker-compose.yml. And here's my docker-compose.yml:

version: '3'
services:
  web:
    build: .
    command: bundle exec rails s -p 3000 -b '0.0.0.0'
    volumes:
      - .:/myapp
    ports:
      - "3000:3000"
    links:
      - db
  db:
    image: mysql:5.7
    environment:
      MYSQL_ROOT_PASSWORD: root

You start your app in console (in app folder) as docker-compose up. Then WAIT 1 MINUTE (let your mysql service to completely load) until some new logs stop appearing in console. Usually the last line should be like

db_1 | 2017-12-24T12:25:20.397174Z 0 [Note] End of list of non-natively partitioned tables

Then (in a new terminal window) apply:

docker-compose run web rake db:create

and then

docker-compose run web rake db:migrate

After you finish your work stop the loaded images with

docker-compose stop

Don't use docker-compose down here instead because if you do, you will erase your database content.

Next time when you want to resume your work apply:

docker-compose start

The rest of the things do exactly as explained here: https://docs.docker.com/compose/rails/

Replace first occurrence of string in Python

Use re.sub directly, this allows you to specify a count:

regex.sub('', url, 1)

(Note that the order of arguments is replacement, original not the opposite, as might be suspected.)

Getting "Cannot call a class as a function" in my React Project

This is a general issue, and doesn't appear in a single case. But, the common problem in all the cases is that you forget to import a specific component (doesn't matter if it's either from a library that you installed or a custom made component that you created):

import {SomeClass} from 'some-library'

When you use it later, without importing it, the compiler thinks it's a function. Therefore, it breaks. This is a common example:

imports

...code...

and then somewhere inside your code

<Image {..some props} />

If you forgot to import the component <Image /> then the compiler will not complain like it does for other imports, but will break when it reaches your code.

Optimum way to compare strings in JavaScript?

Well in JavaScript you can check two strings for values same as integers so yo can do this:

  • "A" < "B"
  • "A" == "B"
  • "A" > "B"

And therefore you can make your own function that checks strings the same way as the strcmp().

So this would be the function that does the same:

function strcmp(a, b)
{   
    return (a<b?-1:(a>b?1:0));  
}

Update my gradle dependencies in eclipse

I tried all above options but was still getting error, in my case issue was I have not setup gradle installation directory in eclipse, following worked:

eclipse -> Window -> Preferences -> Gradle -> "Select Local Installation Directory"

Click on Browse button and provide path.

Even though question is answered, thought to share in case somebody else is facing similar issue.

Cheers !

How to install beautiful soup 4 with python 2.7 on windows

You don't need pip for installing Beautiful Soup - you can just download it and run python setup.py install from the directory that you have unzipped BeautifulSoup in (assuming that you have added Python to your system PATH - if you haven't and you don't want to you can run C:\Path\To\Python27\python "C:\Path\To\BeautifulSoup\setup.py" install)

However, you really should install pip - see How to install pip on Windows for how to do that best (via @MartijnPieters comment)

How can I get the day of a specific date with PHP

$date = strtotime('2016-2-3');
$date = date('l', $date);
var_dump($date)

(i added format 'l' so it will return full name of day)

How to make rounded percentages add up to 100%

I wrote a C# version rounding helper, the algorithm is same as Varun Vohra's answer, hope it helps.

public static List<decimal> GetPerfectRounding(List<decimal> original,
    decimal forceSum, int decimals)
{
    var rounded = original.Select(x => Math.Round(x, decimals)).ToList();
    Debug.Assert(Math.Round(forceSum, decimals) == forceSum);
    var delta = forceSum - rounded.Sum();
    if (delta == 0) return rounded;
    var deltaUnit = Convert.ToDecimal(Math.Pow(0.1, decimals)) * Math.Sign(delta);

    List<int> applyDeltaSequence; 
    if (delta < 0)
    {
        applyDeltaSequence = original
            .Zip(Enumerable.Range(0, int.MaxValue), (x, index) => new { x, index })
            .OrderBy(a => original[a.index] - rounded[a.index])
            .ThenByDescending(a => a.index)
            .Select(a => a.index).ToList();
    }
    else
    {
        applyDeltaSequence = original
            .Zip(Enumerable.Range(0, int.MaxValue), (x, index) => new { x, index })
            .OrderByDescending(a => original[a.index] - rounded[a.index])
            .Select(a => a.index).ToList();
    }

    Enumerable.Repeat(applyDeltaSequence, int.MaxValue)
        .SelectMany(x => x)
        .Take(Convert.ToInt32(delta/deltaUnit))
        .ForEach(index => rounded[index] += deltaUnit);

    return rounded;
}

It pass the following Unit test:

[TestMethod]
public void TestPerfectRounding()
{
    CollectionAssert.AreEqual(Utils.GetPerfectRounding(
        new List<decimal> {3.333m, 3.334m, 3.333m}, 10, 2),
        new List<decimal> {3.33m, 3.34m, 3.33m});

    CollectionAssert.AreEqual(Utils.GetPerfectRounding(
        new List<decimal> {3.33m, 3.34m, 3.33m}, 10, 1),
        new List<decimal> {3.3m, 3.4m, 3.3m});

    CollectionAssert.AreEqual(Utils.GetPerfectRounding(
        new List<decimal> {3.333m, 3.334m, 3.333m}, 10, 1),
        new List<decimal> {3.3m, 3.4m, 3.3m});


    CollectionAssert.AreEqual(Utils.GetPerfectRounding(
        new List<decimal> { 13.626332m, 47.989636m, 9.596008m, 28.788024m }, 100, 0),
        new List<decimal> {14, 48, 9, 29});
    CollectionAssert.AreEqual(Utils.GetPerfectRounding(
        new List<decimal> { 16.666m, 16.666m, 16.666m, 16.666m, 16.666m, 16.666m }, 100, 0),
        new List<decimal> { 17, 17, 17, 17, 16, 16 });
    CollectionAssert.AreEqual(Utils.GetPerfectRounding(
        new List<decimal> { 33.333m, 33.333m, 33.333m }, 100, 0),
        new List<decimal> { 34, 33, 33 });
    CollectionAssert.AreEqual(Utils.GetPerfectRounding(
        new List<decimal> { 33.3m, 33.3m, 33.3m, 0.1m }, 100, 0),
        new List<decimal> { 34, 33, 33, 0 });
}

How do I load external fonts into an HTML document?

If you want to support more browsers than the CSS3 fancy, you can look at the open source library cufon javascript library

And here is the API, if you want to do more funky stuff.

Major Pro: Allows you to do what you want / need.

Major Con: Disallows text selection in some browsers, so use is appropiate on header texts (but you can use it in all your site if you want)

How to get 0-padded binary representation of an integer in java?

Starting with Java 11, you can use the repeat(...) method:

"0".repeat(Integer.numberOfLeadingZeros(i) - 16) + Integer.toBinaryString(i)

Or, if you need 32-bit representation of any integer:

"0".repeat(Integer.numberOfLeadingZeros(i != 0 ? i : 1)) + Integer.toBinaryString(i)

How to convert column with string type to int form in pyspark data frame?

from pyspark.sql.types import IntegerType
data_df = data_df.withColumn("Plays", data_df["Plays"].cast(IntegerType()))
data_df = data_df.withColumn("drafts", data_df["drafts"].cast(IntegerType()))

You can run loop for each column but this is the simplest way to convert string column into integer.

Creating a blocking Queue<T> in .NET?

"How can this be improved?"

Well, you need to look at every method in your class and consider what would happen if another thread was simultaneously calling that method or any other method. For example, you put a lock in the Remove method, but not in the Add method. What happens if one thread Adds at the same time as another thread Removes? Bad things.

Also consider that a method can return a second object that provides access to the first object's internal data - for example, GetEnumerator. Imagine one thread is going through that enumerator, another thread is modifying the list at the same time. Not good.

A good rule of thumb is to make this simpler to get right by cutting down the number of methods in the class to the absolute minimum.

In particular, don't inherit another container class, because you will expose all of that class's methods, providing a way for the caller to corrupt the internal data, or to see partially complete changes to the data (just as bad, because the data appears corrupted at that moment). Hide all the details and be completely ruthless about how you allow access to them.

I'd strongly advise you to use off-the-shelf solutions - get a book about threading or use 3rd party library. Otherwise, given what you're attempting, you're going to be debugging your code for a long time.

Also, wouldn't it make more sense for Remove to return an item (say, the one that was added first, as it's a queue), rather than the caller choosing a specific item? And when the queue is empty, perhaps Remove should also block.

Update: Marc's answer actually implements all these suggestions! :) But I'll leave this here as it may be helpful to understand why his version is such an improvement.

How to find what code is run by a button or element in Chrome using Developer Tools

Alexander Pavlov's answer gets the closest to what you want.

Due to the extensiveness of jQuery's abstraction and functionality, a lot of hoops have to be jumped in order to get to the meat of the event. I have set up this jsFiddle to demonstrate the work.


1. Setting up the Event Listener Breakpoint

You were close on this one.

  1. Open the Chrome Dev Tools (F12), and go to the Sources tab.
  2. Drill down to Mouse -> Click
    Chrome Dev Tools -> Sources tab -> Mouse -> Click
    (click to zoom)

2. Click the button!

Chrome Dev Tools will pause script execution, and present you with this beautiful entanglement of minified code:

Chrome Dev Tools paused script execution (click to zoom)


3. Find the glorious code!

Now, the trick here is to not get carried away pressing the key, and keep an eye out on the screen.

  1. Press the F11 key (Step In) until desired source code appears
  2. Source code finally reached
    • In the jsFiddle sample provided above, I had to press F11 108 times before reaching the desired event handler/function
    • Your mileage may vary, depending on the version of jQuery (or framework library) used to bind the events
    • With enough dedication and time, you can find any event handler/function

Desired event handler/function


4. Explanation

I don't have the exact answer, or explanation as to why jQuery goes through the many layers of abstractions it does - all I can suggest is that it is because of the job it does to abstract away its usage from the browser executing the code.

Here is a jsFiddle with a debug version of jQuery (i.e., not minified). When you look at the code on the first (non-minified) breakpoint, you can see that the code is handling many things:

    // ...snip...

    if ( !(eventHandle = elemData.handle) ) {
        eventHandle = elemData.handle = function( e ) {
            // Discard the second event of a jQuery.event.trigger() and
            // when an event is called after a page has unloaded
            return typeof jQuery !== strundefined && jQuery.event.triggered !== e.type ?
                jQuery.event.dispatch.apply( elem, arguments ) : undefined;
        };
    }

    // ...snip...

The reason I think you missed it on your attempt when the "execution pauses and I jump line by line", is because you may have used the "Step Over" function, instead of Step In. Here is a StackOverflow answer explaining the differences.

Finally, the reason why your function is not directly bound to the click event handler is because jQuery returns a function that gets bound. jQuery's function in turn goes through some abstraction layers and checks, and somewhere in there, it executes your function.

Using Python Requests: Sessions, Cookies, and POST

I don't know how stubhub's api works, but generally it should look like this:

s = requests.Session()
data = {"login":"my_login", "password":"my_password"}
url = "http://example.net/login"
r = s.post(url, data=data)

Now your session contains cookies provided by login form. To access cookies of this session simply use

s.cookies

Any further actions like another requests will have this cookie

Display all dataframe columns in a Jupyter Python Notebook

I know this question is a little old but the following worked for me in a Jupyter Notebook running pandas 0.22.0 and Python 3:

import pandas as pd
pd.set_option('display.max_columns', <number of columns>)

You can do the same for the rows too:

pd.set_option('display.max_rows', <number of rows>)

This saves importing IPython, and there are more options in the pandas.set_option documentation: https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.set_option.html

Installing RubyGems in Windows

Another way is to let chocolatey manage your ruby package (and any other package), that way you won't have to put ruby in your path manually:

Install chocolatey first by opening your favourite command prompt and executing:

@powershell -NoProfile -ExecutionPolicy unrestricted -Command "iex ((new-object net.webclient).DownloadString('https://chocolatey.org/install.ps1'))" && SET PATH=%PATH%;%systemdrive%\chocolatey\bin

then all you need to do is type

cinst ruby

In your command prompt and the package installs.

Using a package manager provides overall more control, I'd recommend this for every package that can be installed via chocolatey.

Fixing Segmentation faults in C++

Sometimes the crash itself isn't the real cause of the problem-- perhaps the memory got smashed at an earlier point but it took a while for the corruption to show itself. Check out valgrind, which has lots of checks for pointer problems (including array bounds checking). It'll tell you where the problem starts, not just the line where the crash occurs.

Increase Tomcat memory settings

try setting this

CATALINA_OPTS="-Djava.awt.headless=true -Dfile.encoding=UTF-8 
-server -Xms1536m -Xmx1536m
-XX:NewSize=256m -XX:MaxNewSize=256m -XX:PermSize=256m 
-XX:MaxPermSize=256m -XX:+DisableExplicitGC"

in {$tomcat-folder}\bin\setenv.sh (create it if necessary).

See http://www.mkyong.com/tomcat/tomcat-javalangoutofmemoryerror-permgen-space/ for more details.

How to convert a char array to a string?

Another solution might look like this,

char arr[] = "mom";
std::cout << "hi " << std::string(arr);

which avoids using an extra variable.

What is a loop invariant?

In simple words, it is a LOOP condition that is true in every loop iteration:

for(int i=0; i<10; i++)
{ }

In this we can say state of i is i<10 and i>=0

Any good, visual HTML5 Editor or IDE?

Radrails 3 is supposed to have it, Aptana Studio 3 will have it. Radrails is in beta, so thats kind of a downer, but none the less it is there to give'r a whirl.

It is multi-platform too, for those of us non-Windoze fellas.

Only Add Unique Item To List

If your requirements are to have no duplicates, you should be using a HashSet.

HashSet.Add will return false when the item already exists (if that even matters to you).

You can use the constructor that @pstrjds links to below (or here) to define the equality operator or you'll need to implement the equality methods in RemoteDevice (GetHashCode & Equals).

How open PowerShell as administrator from the run window

Yes, it is possible to run PowerShell through the run window. However, it would be burdensome and you will need to enter in the password for computer. This is similar to how you will need to set up when you run cmd:

runas /user:(ComputerName)\(local admin) powershell.exe

So a basic example would be:

runas /user:MyLaptop\[email protected]  powershell.exe

You can find more information on this subject in Runas.

However, you could also do one more thing :

  • 1: `Windows+R`
  • 2: type: `powershell`
  • 3: type: `Start-Process powershell -verb runAs`

then your system will execute the elevated powershell.

How do I set the default font size in Vim?

For the first one remove the spaces. Whitespace matters for the set command.

set guifont=Monaco:h20

For the second one it should be (the h specifies the height)

set guifont=Monospace:h20

My recommendation for setting the font is to do (if your version supports it)

set guifont=*

This will pop up a menu that allows you to select the font. After selecting the font, type

set guifont?

To show what the current guifont is set to. After that copy that line into your vimrc or gvimrc. If there are spaces in the font add a \ to escape the space.

set guifont=Monospace\ 20

How to quickly clear a JavaScript Object?

Assuming your object name is BASKET, simply set BASKET = "";

Angular 2 Show and Hide an element

There are two options depending what you want to achieve :

  1. You can use the hidden directive to show or hide an element

    <div [hidden]="!edited" class="alert alert-success box-msg" role="alert">
      <strong>List Saved!</strong> Your changes has been saved.
    </div>
    
  2. You can use the ngIf control directive to add or remove the element. This is different of the hidden directive because it does not show / hide the element, but it add / remove from the DOM. You can loose unsaved data of the element. It can be the better choice for an edit component that is cancelled.

    <div *ngIf="edited" class="alert alert-success box-msg" role="alert"> 
      <strong>List Saved!</strong> Your changes has been saved.
    </div>
    

For you problem of change after 3 seconds, it can be due to incompatibility with setTimeout. Did you include angular2-polyfills.js library in your page ?

SQL Connection Error: System.Data.SqlClient.SqlException (0x80131904)

See my post here

How are you? I had the same problem while i was trying connect to MSSQL Server remotely using jdbc (dbeaver on debian).

After a while, i found out that my firewall configuration was not correctly. So maybe it could help you!

Configure the firewall to allow network traffic that is related to SQL Server and to the SQL Server Browser service.

Four exceptions must be configured in Windows Firewall to allow access to SQL Server:

A port exception for TCP Port 1433. In the New Inbound Rule Wizard dialog, use the following information to create a port exception: Select Port Select TCP and specify port 1433 Allow the connection Choose all three profiles (Domain, Private & Public) Name the rule “SQL – TCP 1433" A port exception for UDP Port 1434. Click New Rule again and use the following information to create another port exception: Select Port Select UDP and specify port 1434 Allow the connection Choose all three profiles (Domain, Private & Public) Name the rule “SQL – UDP 1434 A program exception for sqlservr.exe. Click New Rule again and use the following information to create a program exception: Select Program Click Browse to select ‘sqlservr.exe’ at this location: [C:\Program Files\Microsoft SQL Server\MSSQL11.\MSSQL\Binn\sqlservr.exe] where is the name of your SQL instance. Allow the connection Choose all three profiles (Domain, Private & Public) Name the rule SQL – sqlservr.exe A program exception for sqlbrowser.exe Click New Rule again and use the following information to create another program exception: Select Program Click Browse to select sqlbrowser.exe at this location: [C:\Program Files\Microsoft SQL Server\90\Shared\sqlbrowser.exe]. Allow the connection Choose all three profiles (Domain, Private & Public) Name the rule SQL - sqlbrowser.exe

Source: http://blog.citrix24.com/configure-sql-express-to-accept-remote-connections/

How to import an existing X.509 certificate and private key in Java keystore to use in SSL?

And one more:

#!/bin/bash

# We have:
#
# 1) $KEY : Secret key in PEM format ("-----BEGIN RSA PRIVATE KEY-----") 
# 2) $LEAFCERT : Certificate for secret key obtained from some
#    certification outfit, also in PEM format ("-----BEGIN CERTIFICATE-----")   
# 3) $CHAINCERT : Intermediate certificate linking $LEAFCERT to a trusted
#    Self-Signed Root CA Certificate 
#
# We want to create a fresh Java "keystore" $TARGET_KEYSTORE with the
# password $TARGET_STOREPW, to be used by Tomcat for HTTPS Connector.
#
# The keystore must contain: $KEY, $LEAFCERT, $CHAINCERT
# The Self-Signed Root CA Certificate is obtained by Tomcat from the
# JDK's truststore in /etc/pki/java/cacerts

# The non-APR HTTPS connector (APR uses OpenSSL-like configuration, much
# easier than this) in server.xml looks like this 
# (See: https://tomcat.apache.org/tomcat-6.0-doc/ssl-howto.html):
#
#  <Connector port="8443" protocol="org.apache.coyote.http11.Http11Protocol"
#                SSLEnabled="true"
#                maxThreads="150" scheme="https" secure="true"
#                clientAuth="false" sslProtocol="TLS"
#                keystoreFile="/etc/tomcat6/etl-web.keystore.jks"
#                keystorePass="changeit" />
#

# Let's roll:    

TARGET_KEYSTORE=/etc/tomcat6/foo-server.keystore.jks
TARGET_STOREPW=changeit

TLS=/etc/pki/tls

KEY=$TLS/private/httpd/foo-server.example.com.key
LEAFCERT=$TLS/certs/httpd/foo-server.example.com.pem
CHAINCERT=$TLS/certs/httpd/chain.cert.pem

# ----
# Create PKCS#12 file to import using keytool later
# ----

# From https://www.sslshopper.com/ssl-converter.html:
# The PKCS#12 or PFX format is a binary format for storing the server certificate,
# any intermediate certificates, and the private key in one encryptable file. PFX
# files usually have extensions such as .pfx and .p12. PFX files are typically used 
# on Windows machines to import and export certificates and private keys.

TMPPW=$$ # Some random password

PKCS12FILE=`mktemp`

if [[ $? != 0 ]]; then
  echo "Creation of temporary PKCS12 file failed -- exiting" >&2; exit 1
fi

TRANSITFILE=`mktemp`

if [[ $? != 0 ]]; then
  echo "Creation of temporary transit file failed -- exiting" >&2; exit 1
fi

cat "$KEY" "$LEAFCERT" > "$TRANSITFILE"

openssl pkcs12 -export -passout "pass:$TMPPW" -in "$TRANSITFILE" -name etl-web > "$PKCS12FILE"

/bin/rm "$TRANSITFILE"

# Print out result for fun! Bug in doc (I think): "-pass " arg does not work, need "-passin"

openssl pkcs12 -passin "pass:$TMPPW" -passout "pass:$TMPPW" -in "$PKCS12FILE" -info

# ----
# Import contents of PKCS12FILE into a Java keystore. WTF, Sun, what were you thinking?
# ----

if [[ -f "$TARGET_KEYSTORE" ]]; then
  /bin/rm "$TARGET_KEYSTORE"
fi

keytool -importkeystore \
   -deststorepass  "$TARGET_STOREPW" \
   -destkeypass    "$TARGET_STOREPW" \
   -destkeystore   "$TARGET_KEYSTORE" \
   -srckeystore    "$PKCS12FILE" \
   -srcstoretype  PKCS12 \
   -srcstorepass  "$TMPPW" \
   -alias foo-the-server

/bin/rm "$PKCS12FILE"

# ----
# Import the chain certificate. This works empirically, it is not at all clear from the doc whether this is correct
# ----

echo "Importing chain"

TT=-trustcacerts

keytool -import $TT -storepass "$TARGET_STOREPW" -file "$CHAINCERT" -keystore "$TARGET_KEYSTORE" -alias chain

# ----
# Print contents
# ----

echo "Listing result"

keytool -list -storepass "$TARGET_STOREPW" -keystore "$TARGET_KEYSTORE"

Create <div> and append <div> dynamically

var iDiv = document.createElement('div');

iDiv.id = 'block';
iDiv.className = 'block';
document.getElementsByTagName('body')[0].appendChild(iDiv);

var div2 = document.createElement('div');

div2.className = 'block-2';
iDiv.appendChild(div2);

Can I grep only the first n lines of a file?

You can use the following line:

head -n 10 /path/to/file | grep [...]

I'm getting Key error in python

For dict, just use

if key in dict

and don't use searching in key list

if key in dict.keys()

The latter will be more time-consuming.

CMD: Export all the screen content to a text file

If you are looking for each command separately

To export all the output of the command prompt in text files. Simply follow the following syntax.

C:> [syntax] >file.txt

The above command will create result of syntax in file.txt. Where new file.txt will be created on the current folder that you are in.

For example,

C:Result> dir >file.txt

To copy the whole session, Try this:

Copy & Paste a command session as follows:

1.) At the end of your session, click the upper left corner to display the menu.
Then select.. Edit -> Select all

2.) Again, click the upper left corner to display the menu.
Then select.. Edit -> Copy

3.) Open your favorite text editor and use Ctrl+V or your normal
Paste operation to paste in the text.

Concept of void pointer in C programming

Because C is statically-typed, strongly-typed language, you must decide type of variable before compile. When you try to emulate generics in C, you'll end up attempt to rewrite C++ again, so it would be better to use C++ instead.

"TypeError: (Integer) is not JSON serializable" when serializing JSON in Python?

Use the below code to resolve the issue.

import json
from numpyencoder import NumpyEncoder
alerts = {'upper':[1425],'lower':[576],'level':[2],'datetime':['2012-08-08 
15:30']}
afile = open('test.json','w')
afile.write(json.dumps(alerts,encoding='UTF-8',cls=NumpyEncoder))
afile.close()

javascript: Disable Text Select

One might also use, works ok in all browsers, require javascript:

onselectstart = (e) => {e.preventDefault()}

Example:

_x000D_
_x000D_
onselectstart = (e) => {_x000D_
  e.preventDefault()_x000D_
  console.log("nope!")_x000D_
  }
_x000D_
Select me!
_x000D_
_x000D_
_x000D_


One other js alternative, by testing CSS supports, and disable userSelect, or MozUserSelect for Firefox.

_x000D_
_x000D_
let FF_x000D_
if (CSS.supports("( -moz-user-select: none )")){FF = 1} else {FF = 0}_x000D_
(FF===1) ? document.body.style.MozUserSelect="none" : document.body.style.userSelect="none"
_x000D_
Select me!
_x000D_
_x000D_
_x000D_


Pure css, same logic. Warning you will have to extend those rules to every browser, this can be verbose.

_x000D_
_x000D_
@supports (user-select:none) {_x000D_
  div {_x000D_
    user-select:none_x000D_
  }_x000D_
}_x000D_
_x000D_
@supports (-moz-user-select:none) {_x000D_
  div {_x000D_
    -moz-user-select:none_x000D_
  }_x000D_
}
_x000D_
<div>Select me!</div>
_x000D_
_x000D_
_x000D_

What is the format for the PostgreSQL connection string / URL?

the connection url for postgres syntax:

"Server=host ipaddress;Port=5432;Database=dbname;User Id=userid;Password=password;

example:

"Server=192.168.1.163;Port=5432;Database=postgres;User Id=postgres;Password=root;

Setting value of active workbook in Excel VBA

You're probably after Set wbOOR = ThisWorkbook

Just to clarify

ThisWorkbook will always refer to the workbook the code resides in

ActiveWorkbook will refer to the workbook that is active

Be careful how you use this when dealing with multiple workbooks. It really depends on what you want to achieve as to which is the best option.

Remove all special characters except space from a string using JavaScript

Try this:

const strippedString = htmlString.replace(/(<([^>]+)>)/gi, "");
console.log(strippedString);

Extract substring in Bash

Here's a prefix-suffix solution (similar to the solutions given by JB and Darron) that matches the first block of digits and does not depend on the surrounding underscores:

str='someletters_12345_morele34ters.ext'
s1="${str#"${str%%[[:digit:]]*}"}"   # strip off non-digit prefix from str
s2="${s1%%[^[:digit:]]*}"            # strip off non-digit suffix from s1
echo "$s2"                           # 12345

How different is Scrum practice from Agile Practice?

Comparision of Agile to Scrum is similar to comparision of organism to one organ.

Scrum suggests the way of management while it doesn't prescribe everything what is necessary to do to be able to react fast on changes. Only by adding other agile techniques like continuous integration, extreme programming, test driven development your teams will be able to deliver products not just fast, but also product that customer wants with great quality.

Relative imports for the billionth time

__name__ changes depending on whether the code in question is run in the global namespace or as part of an imported module.

If the code is not running in the global space, __name__ will be the name of the module. If it is running in global namespace -- for example, if you type it into a console, or run the module as a script using python.exe yourscriptnamehere.py then __name__ becomes "__main__".

You'll see a lot of python code with if __name__ == '__main__' is used to test whether the code is being run from the global namespace – that allows you to have a module that doubles as a script.

Did you try to do these imports from the console?

Remove URL parameters without refreshing page

//Joraid code is working but i altered as below. it will work if your URL contain "?" mark or not
//replace URL in browser
if(window.location.href.indexOf("?") > -1) {
    var newUrl = refineUrl();
    window.history.pushState("object or string", "Title", "/"+newUrl );
}

function refineUrl()
{
    //get full url
    var url = window.location.href;
    //get url after/  
    var value = url = url.slice( 0, url.indexOf('?') );
    //get the part after before ?
    value  = value.replace('@System.Web.Configuration.WebConfigurationManager.AppSettings["BaseURL"]','');  
    return value;     
}

GitLab remote: HTTP Basic: Access denied and fatal Authentication

It is certainly a bug, ssh works with one of my machines but not the other. I solved it, follow these.

  1. Generate an access token with never expire date, and select all the options available.
  2. Remove the existing SSH keys.
  3. Clone the repo with the https instead of ssh.
  4. Use the username but use the generated access token instead of password.

enter image description here

alternatively you can set remote to http by using this command in the existing repo, and use this command git remote set-url origin https://gitlab.com/[username]/[repo-name].git

How to save the output of a console.log(object) to a file?

Update: You can now just right click

Right click > Save as in the Console panel to save the logged messages to a file.

Original Answer:

You can use this devtools snippet shown below to create a console.save method. It creates a FileBlob from the input, and then automatically downloads it.

(function(console){

console.save = function(data, filename){

    if(!data) {
        console.error('Console.save: No data')
        return;
    }

    if(!filename) filename = 'console.json'

    if(typeof data === "object"){
        data = JSON.stringify(data, undefined, 4)
    }

    var blob = new Blob([data], {type: 'text/json'}),
        e    = document.createEvent('MouseEvents'),
        a    = document.createElement('a')

    a.download = filename
    a.href = window.URL.createObjectURL(blob)
    a.dataset.downloadurl =  ['text/json', a.download, a.href].join(':')
    e.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null)
    a.dispatchEvent(e)
 }
})(console)

Source: http://bgrins.github.io/devtools-snippets/#console-save

Server returned HTTP response code: 401 for URL: https

401 means "Unauthorized", so there must be something with your credentials.

I think that java URL does not support the syntax you are showing. You could use an Authenticator instead.

Authenticator.setDefault(new Authenticator() {

    @Override
    protected PasswordAuthentication getPasswordAuthentication() {          
        return new PasswordAuthentication(login, password.toCharArray());
    }
});

and then simply invoking the regular url, without the credentials.

The other option is to provide the credentials in a Header:

String loginPassword = login+ ":" + password;
String encoded = new sun.misc.BASE64Encoder().encode (loginPassword.getBytes());
URLConnection conn = url.openConnection();
conn.setRequestProperty ("Authorization", "Basic " + encoded);

PS: It is not recommended to use that Base64Encoder but this is only to show a quick solution. If you want to keep that solution, look for a library that does. There are plenty.

Efficiently updating database using SQLAlchemy ORM

Withough testing, I'd try:

for c in session.query(Stuff).all():
     c.foo = c.foo+1
session.commit()

(IIRC, commit() works without flush()).

I've found that at times doing a large query and then iterating in python can be up to 2 orders of magnitude faster than lots of queries. I assume that iterating over the query object is less efficient than iterating over a list generated by the all() method of the query object.

[Please note comment below - this did not speed things up at all].

How to make android listview scrollable?

Practically its not good to do. But if you want to do like this, just make listview's height fixed to wrap_content.

android:layout_height="wrap_content"

Create SQL identity as primary key?

If you're using T-SQL, the only thing wrong with your code is that you used braces {} instead of parentheses ().

PS: Both IDENTITY and PRIMARY KEY imply NOT NULL, so you can omit that if you wish.

IntelliJ Organize Imports

That plugin will automatically do the "organize import" action on file save: https://github.com/dubreuia/intellij-plugin-save-actions.

To install: "File > Settings > Plugins > Browse repositories... > Search 'Save Actions' > Category 'Code tools'". Then activate the "organize import" save action.

How to make Unicode charset in cmd.exe by default?

Reg file

Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\Console]
"CodePage"=dword:fde9

Command Prompt

REG ADD HKCU\Console /v CodePage /t REG_DWORD /d 0xfde9

PowerShell

sp -t d HKCU:\Console CodePage 0xfde9

Cygwin

regtool set /user/Console/CodePage 0xfde9

Replace CRLF using powershell

You have not specified the version, I'm assuming you are using Powershell v3.

Try this:

$path = "C:\Users\abc\Desktop\File\abc.txt"
(Get-Content $path -Raw).Replace("`r`n","`n") | Set-Content $path -Force

Editor's note: As mike z points out in the comments, Set-Content appends a trailing CRLF, which is undesired. Verify with: 'hi' > t.txt; (Get-Content -Raw t.txt).Replace("`r`n","`n") | Set-Content t.txt; (Get-Content -Raw t.txt).EndsWith("`r`n"), which yields $True.

Note this loads the whole file in memory, so you might want a different solution if you want to process huge files.

UPDATE

This might work for v2 (sorry nowhere to test):

$in = "C:\Users\abc\Desktop\File\abc.txt"
$out = "C:\Users\abc\Desktop\File\abc-out.txt"
(Get-Content $in) -join "`n" > $out

Editor's note: Note that this solution (now) writes to a different file and is therefore not equivalent to the (still flawed) v3 solution. (A different file is targeted to avoid the pitfall Ansgar Wiechers points out in the comments: using > truncates the target file before execution begins). More importantly, though: this solution too appends a trailing CRLF, which may be undesired. Verify with 'hi' > t.txt; (Get-Content t.txt) -join "`n" > t.NEW.txt; [io.file]::ReadAllText((Convert-Path t.NEW.txt)).endswith("`r`n"), which yields $True.

Same reservation about being loaded to memory though.

How to run a SQL query on an Excel table?

You can experiment with the native DB driver for Excel in language/platform of your choice. In Java world, you can try with http://code.google.com/p/sqlsheet/ which provides a JDBC driver for working with Excel sheets directly. Similarly, you can get drivers for the DB technology for other platforms.

However, I can guarantee that you will soon hit a wall with the number of features these wrapper libraries provide. Better way will be to use Apache HSSF/POI or similar level of library but it will need more coding effort.

Javascript format date / time

For the date part:(month is 0-indexed while days are 1-indexed)

var date = new Date('2014-8-20');
console.log((date.getMonth()+1) + '/' + date.getDate() + '/' +  date.getFullYear());

for the time you'll want to create a function to test different situations and convert.

Integrating MySQL with Python in Windows

If you are looking for Python 3.2 this seems the best solution I found so far

Source: http://wiki.python.org/moin/MySQL

Flask raises TemplateNotFound error even though template file exists

Another explanation I've figured out for myself When you create the Flask application, the folder where templates is looked for is the folder of the application according to name you've provided to Flask constructor:

app = Flask(__name__)

The __name__ here is the name of the module where application is running. So the appropriate folder will become the root one for folders search.

projects/
    yourproject/
        app/
            templates/

So if you provide instead some random name the root folder for the search will be current folder.

Get current NSDate in timestamp format

If you need time stamp as a string.

time_t result = time(NULL);                
NSString *timeStampString = [@(result) stringValue];

Android Studio: Application Installation Failed

If you do all of things above and still get stuck, just try reopening your Android Studio.

Could not resolve Spring property placeholder

the following property must be added in the gradle.build file

processResources {
    filesMatching("**/*.properties") {
        expand project.properties
    }
}

Additionally, if working with Intellij, the project must be re-imported.

getting the index of a row in a pandas apply function

To access the index in this case you access the name attribute:

In [182]:

df = pd.DataFrame([[1,2,3],[4,5,6]], columns=['a','b','c'])
def rowFunc(row):
    return row['a'] + row['b'] * row['c']

def rowIndex(row):
    return row.name
df['d'] = df.apply(rowFunc, axis=1)
df['rowIndex'] = df.apply(rowIndex, axis=1)
df
Out[182]:
   a  b  c   d  rowIndex
0  1  2  3   7         0
1  4  5  6  34         1

Note that if this is really what you are trying to do that the following works and is much faster:

In [198]:

df['d'] = df['a'] + df['b'] * df['c']
df
Out[198]:
   a  b  c   d
0  1  2  3   7
1  4  5  6  34

In [199]:

%timeit df['a'] + df['b'] * df['c']
%timeit df.apply(rowIndex, axis=1)
10000 loops, best of 3: 163 µs per loop
1000 loops, best of 3: 286 µs per loop

EDIT

Looking at this question 3+ years later, you could just do:

In[15]:
df['d'],df['rowIndex'] = df['a'] + df['b'] * df['c'], df.index
df

Out[15]: 
   a  b  c   d  rowIndex
0  1  2  3   7         0
1  4  5  6  34         1

but assuming it isn't as trivial as this, whatever your rowFunc is really doing, you should look to use the vectorised functions, and then use them against the df index:

In[16]:
df['newCol'] = df['a'] + df['b'] + df['c'] + df.index
df

Out[16]: 
   a  b  c   d  rowIndex  newCol
0  1  2  3   7         0       6
1  4  5  6  34         1      16

jQuery get specific option tag text

$("#list [value='2']").text();

leave a space after the id selector.

When should I use h:outputLink instead of h:commandLink?

The <h:outputLink> renders a fullworthy HTML <a> element with the proper URL in the href attribute which fires a bookmarkable GET request. It cannot directly invoke a managed bean action method.

<h:outputLink value="destination.xhtml">link text</h:outputLink>

The <h:commandLink> renders a HTML <a> element with an onclick script which submits a (hidden) POST form and can invoke a managed bean action method. It's also required to be placed inside a <h:form>.

<h:form>
    <h:commandLink value="link text" action="destination" />
</h:form>

The ?faces-redirect=true parameter on the <h:commandLink>, which triggers a redirect after the POST (as per the Post-Redirect-Get pattern), only improves bookmarkability of the target page when the link is actually clicked (the URL won't be "one behind" anymore), but it doesn't change the href of the <a> element to be a fullworthy URL. It still remains #.

<h:form>
    <h:commandLink value="link text" action="destination?faces-redirect=true" />
</h:form>

Since JSF 2.0, there's also the <h:link> which can take a view ID (a navigation case outcome) instead of an URL. It will generate a HTML <a> element as well with the proper URL in href.

<h:link value="link text" outcome="destination" />

So, if it's for pure and bookmarkable page-to-page navigation like the SO username link, then use <h:outputLink> or <h:link>. That's also better for SEO since bots usually doesn't cipher POST forms nor JS code. Also, UX will be improved as the pages are now bookmarkable and the URL is not "one behind" anymore.

When necessary, you can do the preprocessing job in the constructor or @PostConstruct of a @RequestScoped or @ViewScoped @ManagedBean which is attached to the destination page in question. You can make use of @ManagedProperty or <f:viewParam> to set GET parameters as bean properties.

See also:

MySQL INNER JOIN Alias

Use a seperate column to indicate the join condition

SELECT  t.importid, 
        case 
            when t.importid = g.home 
            then 'home' 
            else 'away' 
        end as join_condition, 
        g.network, 
        g.date_start 
FROM    game g
INNER JOIN team t ON (t.importid = g.home OR t.importid = g.away)
ORDER BY date_start DESC 
LIMIT 7

How to remove all ListBox items?

  • VB ListBox2.DataSource = Nothing
  • C# ListBox2.DataSource = null;

Undefined symbols for architecture i386

At the risk of sounding obvious, always check the spelling of your forward class files. Sometimes XCode (at least XCode 4.3.2) will turn a declaration green that's actually camel cased incorrectly. Like in this example:

"_OBJC_CLASS_$_RadioKit", referenced from:
  objc-class-ref in RadioPlayerViewController.o

If RadioKit was a class file and you make it a property of another file, in the interface declaration, you might see that

Radiokit *rk;

has "Radiokit" in green when the actual decalaration should be:

RadioKit *rk;

This error will also throw this type of error. Another example (in my case), is when you have _iPhone and _iphone extensions on your class names for universal apps. Once I changed the appropriate file from _iphone to the correct _iPhone, the errors went away.

Is it better to use "is" or "==" for number comparison in Python?

>>> 2 == 2.0
True
>>> 2 is 2.0
False

Use ==

Get exit code of a background process

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

Here is my example.

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

The launcher process is called launch.sh:

#!/bin/bash

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

set -o monitor
trap "handle_chld" CHLD

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

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

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

'Operation is not valid due to the current state of the object' error during postback

I didn't apply paging on my gridview and it extends to more than 600 records (with checkbox, buttons, etc.) and the value of 2001 didn't work. You may increase the value, say 10000 and test.

<appSettings>
<add key="aspnet:MaxHttpCollectionKeys" value="10000" />
</appSettings>

Regex allow digits and a single dot

If you want to allow 1 and 1.2:

(?<=^| )\d+(\.\d+)?(?=$| )

If you want to allow 1, 1.2 and .1:

(?<=^| )\d+(\.\d+)?(?=$| )|(?<=^| )\.\d+(?=$| )

If you want to only allow 1.2 (only floats):

(?<=^| )\d+\.\d+(?=$| )

\d allows digits (while \D allows anything but digits).

(?<=^| ) checks that the number is preceded by either a space or the beginning of the string. (?=$| ) makes sure the string is followed by a space or the end of the string. This makes sure the number isn't part of another number or in the middle of words or anything.

Edit: added more options, improved the regexes by adding lookahead- and behinds for making sure the numbers are standalone (i.e. aren't in the middle of words or other numbers.

XSLT string replace

You can use the following code when your processor runs on .NET or uses MSXML (as opposed to Java-based or other native processors). It uses msxsl:script.

Make sure to add the namespace xmlns:msxsl="urn:schemas-microsoft-com:xslt" to your root xsl:stylesheet or xsl:transform element.

In addition, bind outlet to any namespace you like, for instance xmlns:outlet = "http://my.functions".

<msxsl:script implements-prefix="outlet" language="javascript">
function replace_str(str_text,str_replace,str_by)
{
     return str_text.replace(str_replace,str_by);
}
</msxsl:script>


<xsl:variable name="newtext" select="outlet:replace_str(string(@oldstring),'me','you')" />

How to initialize an array in Java?

Maybe this will work:

public class Array {

    int data[] = new int[10]; 
    /* Creates a new instance of Array */
    public Array() {
        data= {10,20,30,40,50,60,71,80,90,91};
    }
}

Converting JSONarray to ArrayList

I have fast solution. Just create a file ArrayUtil.java

import java.util.ArrayList;
import java.util.Collection;
import org.json.JSONArray;
import org.json.JSONException;

public class ArrayUtil
{
    public static ArrayList<Object> convert(JSONArray jArr)
    {
        ArrayList<Object> list = new ArrayList<Object>();
        try {
            for (int i=0, l=jArr.length(); i<l; i++){
                 list.add(jArr.get(i));
            }
        } catch (JSONException e) {}

        return list;
    }

    public static JSONArray convert(Collection<Object> list)
    {
        return new JSONArray(list);
    }

}

Usage:

ArrayList<Object> list = ArrayUtil.convert(jArray);

or

JSONArray jArr = ArrayUtil.convert(list);

MySQL Results as comma separated list

Instead of using group concat() you can use just concat()

Select concat(Col1, ',', Col2) as Foo_Bar from Table1;

edit this only works in mySQL; Oracle concat only accepts two arguments. In oracle you can use something like select col1||','||col2||','||col3 as foobar from table1; in sql server you would use + instead of pipes.

Loop over html table and get checked checkboxes (JQuery)

use .filter(':has(:checkbox:checked)' ie:

$('#mytable tr').filter(':has(:checkbox:checked)').each(function() {
 $('#out').append(this.id);
});

Create a simple 10 second countdown

A solution using Promises, includes both progress bar & text countdown.

_x000D_
_x000D_
ProgressCountdown(10, 'pageBeginCountdown', 'pageBeginCountdownText').then(value => alert(`Page has started: ${value}.`));_x000D_
_x000D_
function ProgressCountdown(timeleft, bar, text) {_x000D_
  return new Promise((resolve, reject) => {_x000D_
    var countdownTimer = setInterval(() => {_x000D_
      timeleft--;_x000D_
_x000D_
      document.getElementById(bar).value = timeleft;_x000D_
      document.getElementById(text).textContent = timeleft;_x000D_
_x000D_
      if (timeleft <= 0) {_x000D_
        clearInterval(countdownTimer);_x000D_
        resolve(true);_x000D_
      }_x000D_
    }, 1000);_x000D_
  });_x000D_
}
_x000D_
<div class="row begin-countdown">_x000D_
  <div class="col-md-12 text-center">_x000D_
    <progress value="10" max="10" id="pageBeginCountdown"></progress>_x000D_
    <p> Begining in <span id="pageBeginCountdownText">10 </span> seconds</p>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Add a reference column migration in Rails 4

Rails 4.x

When you already have users and uploads tables and wish to add a new relationship between them.

All you need to do is: just generate a migration using the following command:

rails g migration AddUserToUploads user:references

Which will create a migration file as:

class AddUserToUploads < ActiveRecord::Migration
  def change
    add_reference :uploads, :user, index: true
  end
end

Then, run the migration using rake db:migrate. This migration will take care of adding a new column named user_id to uploads table (referencing id column in users table), PLUS it will also add an index on the new column.

UPDATE [For Rails 4.2]

Rails can’t be trusted to maintain referential integrity; relational databases come to our rescue here. What that means is that we can add foreign key constraints at the database level itself and ensure that database would reject any operation that violates this set referential integrity. As @infoget commented, Rails 4.2 ships with native support for foreign keys(referential integrity). It's not required but you might want to add foreign key(as it's very useful) to the reference that we created above.

To add foreign key to an existing reference, create a new migration to add a foreign key:

class AddForeignKeyToUploads < ActiveRecord::Migration
  def change
    add_foreign_key :uploads, :users
  end
end

To create a completely brand new reference with a foreign key(in Rails 4.2), generate a migration using the following command:

rails g migration AddUserToUploads user:references

which will create a migration file as:

class AddUserToUploads < ActiveRecord::Migration
  def change
    add_reference :uploads, :user, index: true
    add_foreign_key :uploads, :users
  end
end

This will add a new foreign key to the user_id column of the uploads table. The key references the id column in users table.

NOTE: This is in addition to adding a reference so you still need to create a reference first then foreign key (you can choose to create a foreign key in the same migration or a separate migration file). Active Record only supports single column foreign keys and currently only mysql, mysql2 and PostgreSQL adapters are supported. Don't try this with other adapters like sqlite3, etc. Refer to Rails Guides: Foreign Keys for your reference.

SQL Server 2012 Install or add Full-text search

You can add full text to an existing instance by changing the SQL Server program in Programs and Features. Follow the steps below. You might need the original disk or ISO for the installation to complete. (Per HotN's comment: If you have SQL Server Express, make sure it is SQL Server Express With Advanced Services.)

Directions:

  1. Open the Programs and Features control panel.
  2. Select Microsoft SQL Server 2012 and click Change.
  3. When prompted to Add/Repair/Remove, select Add.
  4. Advance through the wizard until the Feature Selection screen. Then select Full-Text Search.

Step 1 Step 2

enter image description here

  1. On the Installation Type screen, select the appropriate SQL Server instance.

  2. Advance through the rest of the wizard.

Source (with screenshots): http://www.techrepublic.com/blog/networking/adding-sql-full-text-search-to-an-existing-sql-server/5546

Which exception should I raise on bad/illegal argument combinations in Python?

I'm not sure I agree with inheritance from ValueError -- my interpretation of the documentation is that ValueError is only supposed to be raised by builtins... inheriting from it or raising it yourself seems incorrect.

Raised when a built-in operation or function receives an argument that has the right type but an inappropriate value, and the situation is not described by a more precise exception such as IndexError.

-- ValueError documentation

ISO time (ISO 8601) in Python

You'll need to use os.stat to get the file creation time and a combination of time.strftime and time.timezone for formatting:

>>> import time
>>> import os
>>> t = os.stat('C:/Path/To/File.txt').st_ctime
>>> t = time.localtime(t)
>>> formatted = time.strftime('%Y-%m-%d %H:%M:%S', t)
>>> tz = str.format('{0:+06.2f}', float(time.timezone) / 3600)
>>> final = formatted + tz
>>> 
>>> final
'2008-11-24 14:46:08-02.00'

How can I make this try_files directive work?

a very common try_files line which can be applied on your condition is

location / {
    try_files $uri $uri/ /test/index.html;
}

you probably understand the first part, location / matches all locations, unless it's matched by a more specific location, like location /test for example

The second part ( the try_files ) means when you receive a URI that's matched by this block try $uri first, for example http://example.com/images/image.jpg nginx will try to check if there's a file inside /images called image.jpg if found it will serve it first.

Second condition is $uri/ which means if you didn't find the first condition $uri try the URI as a directory, for example http://example.com/images/, ngixn will first check if a file called images exists then it wont find it, then goes to second check $uri/ and see if there's a directory called images exists then it will try serving it.

Side note: if you don't have autoindex on you'll probably get a 403 forbidden error, because directory listing is forbidden by default.

EDIT: I forgot to mention that if you have index defined, nginx will try to check if the index exists inside this folder before trying directory listing.

Third condition /test/index.html is considered a fall back option, (you need to use at least 2 options, one and a fall back), you can use as much as you can (never read of a constriction before), nginx will look for the file index.html inside the folder test and serve it if it exists.

If the third condition fails too, then nginx will serve the 404 error page.

Also there's something called named locations, like this

location @error {
}

You can call it with try_files like this

try_files $uri $uri/ @error;

TIP: If you only have 1 condition you want to serve, like for example inside folder images you only want to either serve the image or go to 404 error, you can write a line like this

location /images {
    try_files $uri =404;
}

which means either serve the file or serve a 404 error, you can't use only $uri by it self without =404 because you need to have a fallback option.
You can also choose which ever error code you want, like for example:

location /images {
    try_files $uri =403;
}

This will show a forbidden error if the image doesn't exist, or if you use 500 it will show server error, etc ..

WordPress - Check if user is logged in

Use the is_user_logged_in function:

if ( is_user_logged_in() ) {
   // your code for logged in user 
} else {
   // your code for logged out user 
}

You don't have permission to access / on this server

Check the apache User and Group setting in the httpd.conf. It should default to apache on AMI/RedHat or www-data on Debian.

grep '^Group\|^User' /etc/httpd/conf/httpd.conf

Then add the apache user to the group setting of your site's root directory.

sudo usermod -a -G <your-site-root-dir-group> apache

Vim for Windows - What do I type to save and exit from a file?

Instead of telling you how you could execute a certain command (Esc:wq), I can provide you two links that may help you with VIM:

However, the best way to learn Vim is not only using it for Git commits, but as a regular editor for your everyday work.

If you're not going to switch to Vim, it's nonsense to keep its commands in mind. In that case, go and set up your favourite editor to use with Git.

importing go files in same folder

I just wanted something really basic to move some files out of the main folder, like user2889485's reply, but his specific answer didnt work for me. I didnt care if they were in the same package or not.

My GOPATH workspace is c:\work\go and under that I have

/src/pg/main.go      (package main)
/src/pg/dbtypes.go   (pakage dbtypes)

in main.go I import "/pg/dbtypes"

Running JAR file on Windows

Making a start.bat was the only thing that worked for me.

open a text document and enter. java -jar whatever yours is called .jar

save as start.bat in the same folder as the .jar file you want to execute. and then run the. bat

Wireshark localhost traffic capture

If you're using Windows it's not possible - read below. You can use the local address of your machine instead and then you'll be able to capture stuff. See CaptureSetup/Loopback.

Summary: you can capture on the loopback interface on Linux, on various BSDs including Mac OS X, and on Digital/Tru64 UNIX, and you might be able to do it on Irix and AIX, but you definitely cannot do so on Solaris, HP-UX....

Although the page mentions that this is not possible on Windows using Wireshark alone, you can actually record it using a workaround as mentioned in a different answer.


EDIT: Some 3 years later, this answer is no longer completely correct. The linked page contains instructions for capturing on the loopback interface.

How can I show the table structure in SQL Server query?

To print a schema, I use jade and do an export to a file of the database then bring it into word to format and print

FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory in ionic 3

In my case it was a recursion that was causing react to use up all memory.

This happened when I was refactoring my code and didn't notice this.

const SumComponent = () => {
  return (
    <>
      <SumComponent />
    </>
  ) 
}

In other node apps this might look like:

const someFunction = () => {
  ...
  someFunction(); 
  ...
}

Merging two arrayLists into a new arrayList, with no duplicates and in order, in Java

Perhaps my nested for loops being used incorrectly?

Hint: nested loops won't work for this problem. A simple for loop won't work either.

You need to visualize the problem.

Write two ordered lists on a piece of paper, and using two fingers to point the elements of the respective lists, step through them as you do the merge in your head. Then translate your mental decision process into an algorithm and then code.

The optimal solution makes a single pass through the two lists.

Concat all strings inside a List<string> using LINQ

List<string> strings = new List<string>() { "ABC", "DEF", "GHI" };
string s = strings.Aggregate((a, b) => a + ',' + b);

rails + MySQL on OSX: Library not loaded: libmysqlclient.18.dylib

I confirm patch from Abhishek does work.

it work for Yosemite, too.

note: instead of linking to a particular version of mysql, use the fact mysql already built symlink:

sudo ln -s /usr/local/mysql/lib/libmysqlclient.18.dylib /usr/lib/libmysqlclient.18.dylib

this solution does work for Xcode and C API.

Jquery bind double click and single click separately

Same as the above answer but allows for triple click. (Delay 500) http://jsfiddle.net/luenwarneke/rV78Y/1/

    var DELAY = 500,
    clicks = 0,
    timer = null;

$(document).ready(function() {
    $("a")
    .on("click", function(e){
        clicks++;  //count clicks
        timer = setTimeout(function() {
        if(clicks === 1) {
           alert('Single Click'); //perform single-click action
        } else if(clicks === 2) {
           alert('Double Click'); //perform single-click action
        } else if(clicks >= 3) {
           alert('Triple Click'); //perform Triple-click action
        }
         clearTimeout(timer);
         clicks = 0;  //after action performed, reset counter
       }, DELAY);
    })
    .on("dblclick", function(e){
        e.preventDefault();  //cancel system double-click event
    });
});

Eclipse doesn't stop at breakpoints

Please un check this from the Eclipse Menu.

Run->Skip all breakpoints.

I think this will be enabled permanently once You select the Remove all Break points option in the Debug/Breakpoints window.

SQL Server Insert if not exists

The INSERT command doesn't have a WHERE clause - you'll have to write it like this:

ALTER PROCEDURE [dbo].[EmailsRecebidosInsert]
  (@_DE nvarchar(50),
   @_ASSUNTO nvarchar(50),
   @_DATA nvarchar(30) )
AS
BEGIN
   IF NOT EXISTS (SELECT * FROM EmailsRecebidos 
                   WHERE De = @_DE
                   AND Assunto = @_ASSUNTO
                   AND Data = @_DATA)
   BEGIN
       INSERT INTO EmailsRecebidos (De, Assunto, Data)
       VALUES (@_DE, @_ASSUNTO, @_DATA)
   END
END

How to write URLs in Latex?

You just need to escape characters that have special meaning: # $ % & ~ _ ^ \ { }

So

http://stack_overflow.com/~foo%20bar#link

would be

http://stack\_overflow.com/\~foo\%20bar\#link

What does %s and %d mean in printf in the C language?

%(letter) denotes the format type of the replacement text. %s specifies a string, %d an integer, and %c a char.

How to check if cursor exists (open status)

This happened to me when a stored procedure running in SSMS encountered an error during the loop, while the cursor was in use to iterate over records and before the it was closed. To fix it I added extra code in the CATCH block to close the cursor if it is still open (using CURSOR_STATUS as other answers here suggest).

Namespace for [DataContract]

[DataContract] and [DataMember] attribute are found in System.ServiceModel namespace which is in System.ServiceModel.dll .

System.ServiceModel uses the System and System.Runtime.Serialization namespaces to serialize the datamembers.

Way to *ngFor loop defined number of times instead of repeating over array?

Within your component, you can define an array of number (ES6) as described below:

export class SampleComponent {
  constructor() {
    this.numbers = Array(5).fill(0).map((x,i)=>i);
  }
}

See this link for the array creation: Tersest way to create an array of integers from 1..20 in JavaScript.

You can then iterate over this array with ngFor:

@View({
  template: `
    <ul>
      <li *ngFor="let number of numbers">{{number}}</li>
    </ul>
  `
})
export class SampleComponent {
  (...)
}

Or shortly:

@View({
  template: `
    <ul>
      <li *ngFor="let number of [0,1,2,3,4]">{{number}}</li>
    </ul>
  `
})
export class SampleComponent {
  (...)
}

Hope it helps you, Thierry

Edit: Fixed the fill statement and template syntax.

How can I count the occurrences of a list item?

if you want a number of occurrences for the particular element:

>>> from collections import Counter
>>> z = ['blue', 'red', 'blue', 'yellow', 'blue', 'red']
>>> single_occurrences = Counter(z)
>>> print(single_occurrences.get("blue"))
3
>>> print(single_occurrences.values())
dict_values([3, 2, 1])

Sending message through WhatsApp

Use direct URL of whatsapp

String url = "https://api.whatsapp.com/send?phone="+number;
Intent i = new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(url));
startActivity(i);

Fire event on enter key press for a textbox

<input type="text" id="txtCode" name="name" class="text_cs">

and js:

<script type="text/javascript">
$('.text_cs').on('change', function () {
var pid = $(this).val();
console.log("Value text: " + pid);
});
</script>

Get String in YYYYMMDD format from JS date object?

Here's a compact little function that's easy to read and avoids local variables, which can be time-sinks in JavaScript. I don't use prototypes to alter standard modules, because it pollutes the namespace and can lead to code that doesn't do what you think it should.

The main function has a stupid name, but it gets the idea across.

function dateToYYYYMMDDhhmmss(date) {
    function pad(num) {
        num = num + '';
        return num.length < 2 ? '0' + num : num;
    }
    return date.getFullYear() + '/' +
        pad(date.getMonth() + 1) + '/' +
        pad(date.getDate()) + ' ' +
        pad(date.getHours()) + ':' +
        pad(date.getMinutes()) + ':' +
        pad(date.getSeconds());
}

New Line Issue when copying data from SQL Server 2012 to Excel

you really could find out which rows / data has carriage returns and fix the source data.. instead of just put a bandaid on it.

UPDATE table Set Field = Replace(Replace(Field, CHAR(10), ' '), CHAR(13), ' ') WHERE Field like '%' + CHAR(10) + '%' or Field like '%' + CHAR(13) + '%'

MongoDB running but can't connect using shell

Delete /var/lib/mongodb/mongod.lock, then issue sudo service mongodb start, then mongo.

pip install from git repo branch

Instructions to install from private repo using ssh credentials:

$ pip install git+ssh://[email protected]/myuser/foo.git@my_version

how to convert string into time format and add two hours

You can use SimpleDateFormat to convert the String to Date. And after that you have two options,

  • Make a Calendar object and and then use that to add two hours, or
  • get the time in millisecond from that date object, and add two hours like, (2 * 60 * 60 * 1000)

    SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    
    // replace with your start date string
    Date d = df.parse("2008-04-16 00:05:05"); 
    Calendar gc = new GregorianCalendar();
    gc.setTime(d);
    gc.add(Calendar.HOUR, 2);
    Date d2 = gc.getTime();
    

    Or,

    SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    
    // replace with your start date string
    Date d = df.parse("2008-04-16 00:05:05");
    Long time = d.getTime();
    time +=(2*60*60*1000);
    Date d2 = new Date(time);
    

Have a look to these tutorials.

Eclipse will not start and I haven't changed anything

Definitely a network/proxy thing. I connect via wifi and a corporate gateway. Deleted workspace, reinstalled GGTS - still hangs. Turn off the network - launches fine.

Save plot to image file instead of displaying it using Matplotlib

import datetime
import numpy as np
from matplotlib.backends.backend_pdf import PdfPages
import matplotlib.pyplot as plt

# Create the PdfPages object to which we will save the pages:
# The with statement makes sure that the PdfPages object is closed properly at
# the end of the block, even if an Exception occurs.
with PdfPages('multipage_pdf.pdf') as pdf:
    plt.figure(figsize=(3, 3))
    plt.plot(range(7), [3, 1, 4, 1, 5, 9, 2], 'r-o')
    plt.title('Page One')
    pdf.savefig()  # saves the current figure into a pdf page
    plt.close()

    plt.rc('text', usetex=True)
    plt.figure(figsize=(8, 6))
    x = np.arange(0, 5, 0.1)
    plt.plot(x, np.sin(x), 'b-')
    plt.title('Page Two')
    pdf.savefig()
    plt.close()

    plt.rc('text', usetex=False)
    fig = plt.figure(figsize=(4, 5))
    plt.plot(x, x*x, 'ko')
    plt.title('Page Three')
    pdf.savefig(fig)  # or you can pass a Figure object to pdf.savefig
    plt.close()

    # We can also set the file's metadata via the PdfPages object:
    d = pdf.infodict()
    d['Title'] = 'Multipage PDF Example'
    d['Author'] = u'Jouni K. Sepp\xe4nen'
    d['Subject'] = 'How to create a multipage pdf file and set its metadata'
    d['Keywords'] = 'PdfPages multipage keywords author title subject'
    d['CreationDate'] = datetime.datetime(2009, 11, 13)
    d['ModDate'] = datetime.datetime.today()

Git on Mac OS X v10.7 (Lion)

You have to find where the Git executable is and then add the folder to the PATH environment variable in file .bash_profile.

Using terminal:

  1. Search for Git:

     sudo find / -name git
    
  2. Edit the .bash_profile file. Add:

     PATH="<Directory of Git>:$PATH"
    

Git is back :-)

Anyway, I suggest you to install Git using MacPorts. In this way you can easily upgrade your Git instance to the newest release.

Using Javascript can you get the value from a session attribute set by servlet in the HTML page

Below code may help you to achieve session attribution inside java script:

var name = '<%= session.getAttribute("username") %>';

Dynamic classname inside ngClass in angular 2

  <div *ngFor="let celeb of singers">
  <p [ngClass]="{
    'text-success':celeb.country === 'USA',
    'text-secondary':celeb.country === 'Canada',
    'text-danger':celeb.country === 'Puorto Rico',
    'text-info':celeb.country === 'India'
  }">{{ celeb.artist }} ({{ celeb.country }})
</p>
</div>

Git diff against a stash

FWIW This may be a bit redundant to all the other answers and is very similar to the accepted answer which is spot on; but maybe it will help someone out.

git stash show --help will give you all you should need; including stash show info.

show [<stash>]

Show the changes recorded in the stash as a diff between the stashed state and its original parent. When no is given, shows the latest one. By default, the command shows the diffstat, but it will accept any format known to git diff (e.g., git stash show -p stash@{1} to view the second most recent stash in patch form). You can use stash.showStat and/or stash.showPatch config variables to change the default behavior.

how to use javascript Object.defineProperty

defineProperty is a method on Object which allow you to configure the properties to meet some criterias. Here is a simple example with an employee object with two properties firstName & lastName and append the two properties by overriding the toString method on the object.

var employee = {
    firstName: "Jameel",
    lastName: "Moideen"
};
employee.toString=function () {
    return this.firstName + " " + this.lastName;
};
console.log(employee.toString());

You will get Output as : Jameel Moideen

I am going to change the same code by using defineProperty on the object

var employee = {
    firstName: "Jameel",
    lastName: "Moideen"
};
Object.defineProperty(employee, 'toString', {
    value: function () {
        return this.firstName + " " + this.lastName;
    },
    writable: true,
    enumerable: true,
    configurable: true
});
console.log(employee.toString());

The first parameter is the name of the object and then second parameter is name of the property we are adding , in our case it’s toString and then the last parameter is json object which have a value going to be a function and three parameters writable,enumerable and configurable.Right now I just declared everything as true.

If u run the example you will get Output as : Jameel Moideen

Let’s understand why we need the three properties such as writable,enumerable and configurable.

writable

One of the very annoying part of the javascript is , if you change the toString property to something else for example

enter image description here

if you run this again , everything gets breaks. Let’s change writable to false. If run the same again you will get the correct output as ‘Jameel Moideen’ . This property will prevent overwrite this property later.

enumerable

if you print all the keys inside the object , you can see all the properties including toString.

console.log(Object.keys(employee));

enter image description here

if you set enumerable to false , you can hide toString property from everybody else. If run this again you will get firstName,lastName

configurable

if someone later redefined the object on later for example enumerable to true and run it. You can see toString property came again.

var employee = {
    firstName: "Jameel",
    lastName: "Moideen"
};
Object.defineProperty(employee, 'toString', {
    value: function () {
        return this.firstName + " " + this.lastName;
    },
    writable: false,
    enumerable: false,
    configurable: true
});

//change enumerable to false
Object.defineProperty(employee, 'toString', {

    enumerable: true
});
employee.toString="changed";
console.log(Object.keys(employee));

enter image description here

you can restrict this behavior by set configurable to false.

Orginal reference of this information is from my personal Blog

What is `git push origin master`? Help with git's refs, heads and remotes

Git has two types of branches: local and remote. To use git pull and git push as you'd like, you have to tell your local branch (my_test) which remote branch it's tracking. In typical Git fashion this can be done in both the config file and with commands.

Commands

Make sure you're on your master branch with

1)git checkout master

then create the new branch with

2)git branch --track my_test origin/my_test

and check it out with

3)git checkout my_test.

You can then push and pull without specifying which local and remote.

However if you've already created the branch then you can use the -u switch to tell git's push and pull you'd like to use the specified local and remote branches from now on, like so:

git pull -u my_test origin/my_test
git push -u my_test origin/my_test

Config

The commands to setup remote branch tracking are fairly straight forward but I'm listing the config way as well as I find it easier if I'm setting up a bunch of tracking branches. Using your favourite editor open up your project's .git/config and add the following to the bottom.

[remote "origin"]
    url = [email protected]:username/repo.git
    fetch = +refs/heads/*:refs/remotes/origin/*
[branch "my_test"]
    remote = origin
    merge = refs/heads/my_test

This specifies a remote called origin, in this case a GitHub style one, and then tells the branch my_test to use it as it's remote.

You can find something very similar to this in the config after running the commands above.

Some useful resources:

Easiest way to rotate by 90 degrees an image using OpenCV?

As of OpenCV3.2, life just got a bit easier, you can now rotate an image in a single line of code:

cv::rotate(image, image, cv::ROTATE_90_CLOCKWISE);

For the direction you can choose any of the following:

ROTATE_90_CLOCKWISE
ROTATE_180
ROTATE_90_COUNTERCLOCKWISE

Parsing time string in Python

Here's a stdlib solution that supports a variable utc offset in the input time string:

>>> from email.utils import parsedate_tz, mktime_tz
>>> from datetime import datetime, timedelta
>>> timestamp = mktime_tz(parsedate_tz('Tue May 08 15:14:45 +0800 2012'))
>>> utc_time = datetime(1970, 1, 1) + timedelta(seconds=timestamp)
>>> utc_time
datetime.datetime(2012, 5, 8, 7, 14, 45)

Base64 encoding in SQL Server 2005 T-SQL

DECLARE @source varbinary(max),  
@encoded_base64 varchar(max),  
@decoded varbinary(max) 
SET @source = CONVERT(varbinary(max), 'welcome') 
-- Convert from varbinary to base64 string 
SET @encoded_base64 = CAST(N'' AS xml).value('xs:base64Binary(sql:variable       
("@source"))', 'varchar(max)') 
  -- Convert back from base64 to varbinary 
   SET @decoded = CAST(N'' AS xml).value('xs:base64Binary(sql:variable             
  ("@encoded_base64"))', 'varbinary(max)') 

 SELECT
  CONVERT(varchar(max), @source) AS [Source varchar], 
   @source AS [Source varbinary], 
     @encoded_base64 AS [Encoded base64], 
     @decoded AS [Decoded varbinary], 
     CONVERT(varchar(max), @decoded) AS [Decoded varchar]

This is usefull for encode and decode.

By Bharat J

How to restart ADB manually from Android Studio

open cmd and type the following command

netstat -aon|findstr 5037

and press enter.

you will get a reply like this :

  TCP    127.0.0.1:5037         0.0.0.0:0              LISTENING       3372
  TCP    127.0.0.1:5037         127.0.0.1:50126        TIME_WAIT       0
  TCP    127.0.0.1:5037         127.0.0.1:50127        TIME_WAIT       0
  TCP    127.0.0.1:50127        127.0.0.1:5037         TIME_WAIT       0

this shows the pid which is occupying the adb. in this 3372 is the value. it will not be same for anyone. so you need to do this every time you face this problem.

now type this :

taskkill /pid 3372(the pid you get in the previous step) /f

Voila! now adb runs perfectly.

popup form using html/javascript/css

Here is a resource you can edit and use Download Source Code or see live demo here http://purpledesign.in/blog/pop-out-a-form-using-jquery-and-javascript/

Add a Button or link to your page like this

<p><a href="#inline">click to open</a></p>

“#inline” here should be the “id” of the that will contain the form.

<div id="inline">
 <h2>Send us a Message</h2>
 <form id="contact" name="contact" action="#" method="post">
 <label for="email">Your E-mail</label>
 <input type="email" id="email" name="email" class="txt">
 <br>
 <label for="msg">Enter a Message</label>
 <textarea id="msg" name="msg" class="txtarea"></textarea>
<button id="send">Send E-mail</button>
 </form>
</div>

Include these script to listen of the event of click. If you have an action defined in your form you can use “preventDefault()” method

<script type="text/javascript">
 $(document).ready(function() {
$(".modalbox").fancybox();
$("#contact").submit(function() { return false; });
$("#send").on("click", function(){
var emailval = $("#email").val();
var msgval = $("#msg").val();
var msglen = msgval.length;
var mailvalid = validateEmail(emailval);
if(mailvalid == false) {
$("#email").addClass("error");
}
else if(mailvalid == true){
 $("#email").removeClass("error");
 }

 if(msglen < 4) {
 $("#msg").addClass("error");
 }
 else if(msglen >= 4){
 $("#msg").removeClass("error");
 }

 if(mailvalid == true && msglen >= 4) {
 // if both validate we attempt to send the e-mail
 // first we hide the submit btn so the user doesnt click twice
 $("#send").replaceWith("<em>sending...</em>");
 //This will post it to the php page
 $.ajax({
 type: 'POST',
 url: 'sendmessage.php',
 data: $("#contact").serialize(),
 success: function(data) {
 if(data == "true") {
 $("#contact").fadeOut("fast", function(){
//Display a message on successful posting for 1 sec
 $(this).before("<p><strong>Success! Your feedback has been sent, thanks :)</strong></p>");
 setTimeout("$.fancybox.close()", 1000);
 });
 }
 }
 });
 }
 });
 });
</script>

You can add anything you want to do in your PHP file.

Rock, Paper, Scissors Game Java

int w =0 , l =0, d=0, i=0;
    Scanner sc = new Scanner(System.in);

// try tentimes
    while (i<10) {


        System.out.println("scissor(1) ,Rock(2),Paper(3) ");
        int n = sc.nextInt();
        int m =(int)(Math.random()*3+1);


        if(n==m){

            System.out.println("Com:"+m +"so>>> " + "draw");
            d++;


        }else if ((n-1)%3==(m%3)){
            w++;
            System.out.println("Com:"+m +"so>>> " +"win");
        }
        else if(n >=4 )
        {
            System.out.println("pleas enter correct number)");


    }
        else {
            System.out.println("Com:"+m +"so>>> " +"lose");
            l++;

        }
        i++;

Powershell Log Off Remote Session

Adding plain DOS commands, if someone is so inclined. Yes, this still works for Win 8 and Server 2008 + Server 2012.

Query session /server:Server100

Will return:

SESSIONNAME       USERNAME                 ID  STATE   TYPE        DEVICE
rdp-tcp#0         Bob                       3  Active  rdpwd
rdp-tcp#5         Jim                       9  Active  rdpwd
rdp-tcp                                 65536  Listen

And to log off a session, use:

Reset session 3 /server:Server100

Error With Port 8080 already in use

Click on servers tab in eclipse and then double click on the server listed there. Select the port tab in the config page opened.Change the port to any other ports.Restart the server.

Reading a text file with SQL Server

What does your text file look like?? Each line a record?

You'll have to check out the BULK INSERT statement - that should look something like:

BULK INSERT dbo.YourTableName
FROM 'D:\directory\YourFileName.csv'
WITH
(
  CODEPAGE = '1252',
  FIELDTERMINATOR = ';',
  CHECK_CONSTRAINTS
) 

Here, in my case, I'm importing a CSV file - but you should be able to import a text file just as well.

From the MSDN docs - here's a sample that hopefully works for a text file with one field per row:

BULK INSERT dbo.temp 
   FROM 'c:\temp\file.txt'
   WITH 
      (
         ROWTERMINATOR ='\n'
      )

Seems to work just fine in my test environment :-)

PHP: Convert any string to UTF-8 without knowing the original character set, or at least try

You've probably tried this to but why not just use the mb_convert_encoding function? It will attempt to auto-detect char set of the text provided or you can pass it a list.

Also, I tried to run:

$text = "fiancée";
echo mb_convert_encoding($text, "UTF-8");
echo "<br/><br/>";
echo iconv(mb_detect_encoding($text), "UTF-8", $text);

and the results are the same for both. How do you see that your text is truncated to 'fianc'? is it in the DB or in a browser?

Determine on iPhone if user has enabled push notifications

iOS8+ (OBJECTIVE C)

#import <UserNotifications/UserNotifications.h>


[[UNUserNotificationCenter currentNotificationCenter]getNotificationSettingsWithCompletionHandler:^(UNNotificationSettings * _Nonnull settings) {

    switch (settings.authorizationStatus) {
          case UNAuthorizationStatusNotDetermined:{

            break;
        }
        case UNAuthorizationStatusDenied:{

            break;
        }
        case UNAuthorizationStatusAuthorized:{

            break;
        }
        default:
            break;
    }
}];

C# convert int to string with padding zeros?

int p = 3; // fixed length padding
int n = 55; // number to test

string t = n.ToString("D" + p); // magic     

Console.WriteLine("Hello, world! >> {0}", t);

// outputs: 
// Hello, world! >> 055

$_SERVER["REMOTE_ADDR"] gives server IP rather than visitor IP

PHP 7.0 $_SERVER varibales have changed. var_dump it and see how it fits your reqs.

some of them giving remote details are, REMOTE_ADDR HTTP_X_FORWARDED_FOR HTTP_CF_CONNECTING_IP HTTP_CF_IPCOUNTRY

GCD to perform task in main thread

No you don't need to check if you're in the main thread. Here is how you can do this in Swift:

runThisInMainThread { () -> Void in
    runThisInMainThread { () -> Void in
        // No problem
    }
}

func runThisInMainThread(block: dispatch_block_t) {
    dispatch_async(dispatch_get_main_queue(), block)
}

Its included as a standard function in my repo, check it out: https://github.com/goktugyil/EZSwiftExtensions

How to delete the last row of data of a pandas dataframe

Just use indexing

df.iloc[:-1,:]

That's why iloc exists. You can also use head or tail.

Git stash pop- needs merge, unable to refresh index

git reset if you don't want to commit these changes.

Chrome - ERR_CACHE_MISS

Yes, this is a current issue in Chrome. There is an issue report here.

The fix will appear in 40.x.y.z versions.

Until then? I don't think you can resolve the issue yourself. But you can ignore it. The shown error is only related to the dev tools and does not influence the behavior of your website. If you have any other problems they are not related to this error.

List of all special characters that need to be escaped in a regex

The Pattern.quote(String s) sort of does what you want. However it leaves a little left to be desired; it doesn't actually escape the individual characters, just wraps the string with \Q...\E.

There is not a method that does exactly what you are looking for, but the good news is that it is actually fairly simple to escape all of the special characters in a Java regular expression:

regex.replaceAll("[\\W]", "\\\\$0")

Why does this work? Well, the documentation for Pattern specifically says that its permissible to escape non-alphabetic characters that don't necessarily have to be escaped:

It is an error to use a backslash prior to any alphabetic character that does not denote an escaped construct; these are reserved for future extensions to the regular-expression language. A backslash may be used prior to a non-alphabetic character regardless of whether that character is part of an unescaped construct.

For example, ; is not a special character in a regular expression. However, if you escape it, Pattern will still interpret \; as ;. Here are a few more examples:

  • > becomes \> which is equivalent to >
  • [ becomes \[ which is the escaped form of [
  • 8 is still 8.
  • \) becomes \\\) which is the escaped forms of \ and ( concatenated.

Note: The key is is the definition of "non-alphabetic", which in the documentation really means "non-word" characters, or characters outside the character set [a-zA-Z_0-9].

Object of class stdClass could not be converted to string

Most likely, the userdata() function is returning an object, not a string. Look into the documentation (or var_dump the return value) to find out which value you need to use.

How to set textColor of UILabel in Swift

The easiest workaround is create dummy labels in IB, give them the text the color you like and set to hidden. You can then reference this color in your code to set your label to the desired color.

yourLabel.textColor = hiddenLabel.textColor

The only way I could change the text color programmatically was by using the standard colors, UIColor.white, UIColor.green...

Linux command line howto accept pairing for bluetooth device without pin

follow steps (CentOs):

  1. bluetoothctl
  2. devices
  3. scan on
  4. pair 34:88:5D:51:5A:95 (34:88:5D:51:5A:95 is my device code,replace it with yours)
  5. trust 34:88:5D:51:5A:95
  6. connect 34:88:5D:51:5A:95

If you want more details https://www.youtube.com/watch?v=CB1E4Ir3AV4

Print the data in ResultSet along with column names

1) Instead of PreparedStatement use Statement

2) After executing query in ResultSet, extract values with the help of rs.getString() as :

Statement st=cn.createStatement();
ResultSet rs=st.executeQuery(sql);
while(rs.next())
{
    rs.getString(1); //or rs.getString("column name");
}

How to find most common elements of a list?

In Python 2.7 and above there is a class called Counter which can help you:

from collections import Counter
words_to_count = (word for word in word_list if word[:1].isupper())
c = Counter(words_to_count)
print c.most_common(3)

Result:

[('Jellicle', 6), ('Cats', 5), ('And', 2)]

I am quite new to programming so please try and do it in the most barebones fashion.

You could instead do this using a dictionary with the key being a word and the value being the count for that word. First iterate over the words adding them to the dictionary if they are not present, or else increasing the count for the word if it is present. Then to find the top three you can either use a simple O(n*log(n)) sorting algorithm and take the first three elements from the result, or you can use a O(n) algorithm that scans the list once remembering only the top three elements.

An important observation for beginners is that by using builtin classes that are designed for the purpose you can save yourself a lot of work and/or get better performance. It is good to be familiar with the standard library and the features it offers.

How to get class object's name as a string in Javascript?

This is pretty old, but I ran across this question via Google, so perhaps this solution might be useful to others.

function GetObjectName(myObject){
    var objectName=JSON.stringify(myObject).match(/"(.*?)"/)[1];
    return objectName;
}

It just uses the browser's JSON parser and regex without cluttering up the DOM or your object too much.

Assigning default values to shell variables with a single command in bash

Even you can use like default value the value of another variable

having a file defvalue.sh

#!/bin/bash
variable1=$1
variable2=${2:-$variable1}

echo $variable1
echo $variable2

run ./defvalue.sh first-value second-value output

first-value
second-value

and run ./defvalue.sh first-value output

first-value
first-value

Is there a better way to run a command N times in bash?

All of the existing answers appear to require bash, and don't work with a standard BSD UNIX /bin/sh (e.g., ksh on OpenBSD).

The below code should work on any BSD:

$ echo {1..4}
{1..4}
$ seq 4
sh: seq: not found
$ for i in $(jot 4); do echo e$i; done
e1
e2
e3
e4
$

How to overlay one div over another div

By using a div with style z-index:1; and position: absolute; you can overlay your div on any other div.

z-index determines the order in which divs 'stack'. A div with a higher z-index will appear in front of a div with a lower z-index. Note that this property only works with positioned elements.

Is there a way to use PhantomJS in Python?

The answer by @Pykler is great but the Node requirement is outdated. The comments in that answer suggest the simpler answer, which I've put here to save others time:

  1. Install PhantomJS

    As @Vivin-Paliath points out, it's a standalone project, not part of Node.

    Mac:

    brew install phantomjs
    

    Ubuntu:

    sudo apt-get install phantomjs
    

    etc

  2. Set up a virtualenv (if you haven't already):

    virtualenv mypy  # doesn't have to be "mypy". Can be anything.
    . mypy/bin/activate
    

    If your machine has both Python 2 and 3 you may need run virtualenv-3.6 mypy or similar.

  3. Install selenium:

    pip install selenium
    
  4. Try a simple test, like this borrowed from the docs:

    from selenium import webdriver
    from selenium.webdriver.common.keys import Keys
    
    driver = webdriver.PhantomJS()
    driver.get("http://www.python.org")
    assert "Python" in driver.title
    elem = driver.find_element_by_name("q")
    elem.clear()
    elem.send_keys("pycon")
    elem.send_keys(Keys.RETURN)
    assert "No results found." not in driver.page_source
    driver.close()
    

Save and load MemoryStream to/from a file

The combined answer for writing to a file can be;

MemoryStream ms = new MemoryStream();    
FileStream file = new FileStream("file.bin", FileMode.Create, FileAccess.Write);
ms.WriteTo(file);
file.Close();
ms.Close();

How to capture a list of specific type with mockito

If you're not afraid of old java-style (non type safe generic) semantics, this also works and is simple'ish:

ArgumentCaptor<List> argument = ArgumentCaptor.forClass(List.class);
verify(subject.method(argument.capture()); // run your code
List<SomeType> list = argument.getValue(); // first captured List, etc.

Why do we usually use || over |? What is the difference?

1).(expression1 | expression2), | operator will evaluate expression2 irrespective of whether the result of expression1 is true or false.

Example:

class Or 
{
    public static void main(String[] args) 
    {
        boolean b=true;

        if (b | test());
    }

    static boolean test()
    {
        System.out.println("No short circuit!");
        return false;
    }
}

2).(expression1 || expression2), || operator will not evaluate expression2 if expression1 is true.

Example:

class Or 
{
    public static void main(String[] args) 
    {
        boolean b=true;

        if (b || test())
        {
            System.out.println("short circuit!");
        }
    }

    static boolean test()
    {
        System.out.println("No short circuit!");
        return false;
    }
}

Change a column type from Date to DateTime during ROR migration

First in your terminal:

rails g migration change_date_format_in_my_table

Then in your migration file:

For Rails >= 3.2:

class ChangeDateFormatInMyTable < ActiveRecord::Migration
  def up
    change_column :my_table, :my_column, :datetime
  end

  def down
    change_column :my_table, :my_column, :date
  end
end

I'm getting favicon.ico error

I have had this error for some time as well. It might be some kind of netbeans bug that has to do with netbeans connector. I can't find any mention of favicon.ico in my code or in the project settings.

I was able to fix it by putting the following line in the head section of my html file

<link rel="shortcut icon" href="#">

I am currently using this in my testing environment, but I would remove it for any production environment.

libpthread.so.0: error adding symbols: DSO missing from command line

I also encountered same problem. I do not know why, i just add -lpthread option to compiler and everything ok.

Old:

$ g++ -rdynamic -m64 -fPIE -pie  -o /tmp/node/out/Release/mksnapshot ...*.o *.a -ldl -lrt

got following error. If i append -lpthread option to above command then OK.

/usr/bin/ld: /tmp/node/out/Release/obj.host/v8_libbase/deps/v8/src/base/platform/condition-variable.o: undefined reference to symbol 'pthread_condattr_setclock@@GLIBC_2.3.3'
//lib/x86_64-linux-gnu/libpthread.so.0: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status

SQL Current month/ year question

This should work in MySql

SELECT * FROM 'my_table' WHERE 'month' = MONTH(CURRENT_TIMESTAMP) AND 'year' = YEAR(CURRENT_TIMESTAMP);

Populate dropdown select with array using jQuery

Try for loops:

var numbers = [1, 2, 3, 4, 5];

for (var i=0;i<numbers.length;i++){
   $('<option/>').val(numbers[i]).html(numbers[i]).appendTo('#items');
}

Much better approach:

var numbers = [1, 2, 3, 4, 5];
var option = '';
for (var i=0;i<numbers.length;i++){
   option += '<option value="'+ numbers[i] + '">' + numbers[i] + '</option>';
}
$('#items').append(option);

XPath: difference between dot and text()

There is a difference between . and text(), but this difference might not surface because of your input document.

If your input document looked like (the simplest document one can imagine given your XPath expressions)

Example 1

<html>
  <a>Ask Question</a>
</html>

Then //a[text()="Ask Question"] and //a[.="Ask Question"] indeed return exactly the same result. But consider a different input document that looks like

Example 2

<html>
  <a>Ask Question<other/>
  </a>
</html>

where the a element also has a child element other that follows immediately after "Ask Question". Given this second input document, //a[text()="Ask Question"] still returns the a element, while //a[.="Ask Question"] does not return anything!


This is because the meaning of the two predicates (everything between [ and ]) is different. [text()="Ask Question"] actually means: return true if any of the text nodes of an element contains exactly the text "Ask Question". On the other hand, [.="Ask Question"] means: return true if the string value of an element is identical to "Ask Question".

In the XPath model, text inside XML elements can be partitioned into a number of text nodes if other elements interfere with the text, as in Example 2 above. There, the other element is between "Ask Question" and a newline character that also counts as text content.

To make an even clearer example, consider as an input document:

Example 3

<a>Ask Question<other/>more text</a>

Here, the a element actually contains two text nodes, "Ask Question" and "more text", since both are direct children of a. You can test this by running //a/text() on this document, which will return (individual results separated by ----):

Ask Question
-----------------------
more text

So, in such a scenario, text() returns a set of individual nodes, while . in a predicate evaluates to the string concatenation of all text nodes. Again, you can test this claim with the path expression //a[.='Ask Questionmore text'] which will successfully return the a element.


Finally, keep in mind that some XPath functions can only take one single string as an input. As LarsH has pointed out in the comments, if such an XPath function (e.g. contains()) is given a sequence of nodes, it will only process the first node and silently ignore the rest.

What does `return` keyword mean inside `forEach` function?

The return exits the current function, but the iterations keeps on, so you get the "next" item that skips the if and alerts the 4...

If you need to stop the looping, you should just use a plain for loop like so:

$('button').click(function () {
   var arr = [1, 2, 3, 4, 5];
   for(var i = 0; i < arr.length; i++) {
     var n = arr[i]; 
     if (n == 3) {
         break;
      }
      alert(n);
   })
})

You can read more about js break & continue here: http://www.w3schools.com/js/js_break.asp

What's the difference between SortedList and SortedDictionary?

Enough is said already on the topic, however to keep it simple, here's my take.

Sorted dictionary should be used when-

  • More inserts and delete operations are required.
  • Data in un-ordered.
  • Key access is enough and index access is not required.
  • Memory is not a bottleneck.

On the other side, Sorted List should be used when-

  • More lookups and less inserts and delete operations are required.
  • Data is already sorted (if not all, most).
  • Index access is required.
  • Memory is an overhead.

Hope this helps!!

SQL query to find third highest salary in company

you can find the third most salary with this query:

SELECT min(salary) 
FROM tblEmployee 
WHERE salary IN (SELECT TOP(3) salary 
                 FROM tblEmployee 
                 ORDER BY salary DESC)

How to execute a java .class from the command line

If you have in your java source

package mypackage;

and your class is hello.java with

public class hello {

and in that hello.java you have

 public static void main(String[] args) {

Then (after compilation) changeDir (cd) to the directory where your hello.class is. Then

java -cp . mypackage.hello

Mind the current directory and the package name before the class name. It works for my on linux mint and i hope on the other os's also

Thanks Stack overflow for a wealth of info.

Understanding slice notation

This is just for some extra info... Consider the list below

>>> l=[12,23,345,456,67,7,945,467]

Few other tricks for reversing the list:

>>> l[len(l):-len(l)-1:-1]
[467, 945, 7, 67, 456, 345, 23, 12]

>>> l[:-len(l)-1:-1]
[467, 945, 7, 67, 456, 345, 23, 12]

>>> l[len(l)::-1]
[467, 945, 7, 67, 456, 345, 23, 12]

>>> l[::-1]
[467, 945, 7, 67, 456, 345, 23, 12]

>>> l[-1:-len(l)-1:-1]
[467, 945, 7, 67, 456, 345, 23, 12]

How can I stop the browser back button using JavaScript?

You can just put a small script and then check. It won't allow you to visit previous page.

This is done in JavaScript.

<script type="text/javascript">
    function preventbackbutton() { window.history.forward(); }
    setTimeout("preventbackbutton()", 0);
    window.onunload = function () { null };
</script>

The window.onunload function fires when you try to visit back or previous page through browser.

Bind event to right mouse click

Is contextmenu an event?

I would use onmousedown or onclick then grab the MouseEvent's button property to determine which button was pressed (0 = left, 1 = middle, 2 = right).

How to install Selenium WebDriver on Mac OS

Install

If you use homebrew (which I recommend), you can install selenium using:

brew install selenium-server-standalone

Running

updated -port port_number

To run selenium, do: selenium-server -port 4444

For more options: selenium-server -help

Batch Script to Run as Administrator

If all above answers is not to your liking you can use autoIT to run your file (or what ever file) as a specific user with their credentials.

Sample of a script that will run a program using that users privelages.

installAdmin()

Func installAdmin()
    ; Change the username and password to the appropriate values for your system.
    Local $sUserName = "xxxxx"
    Local $sPassword = "xxx"
    Local $sDirectory = "C:\ASD4VM\Download\"
    Local $sFiletoRun = "Inst_with_Privileges.bat"

    RunAsWait($sUserName, @ComputerName, $sPassword, 0, $sDirectory & $sFiletoRun)
EndFunc   ;==>Example

AutoIT can be found here. -> It uses a .ua3 format that is compiled to a .exe file that can be run.

Using custom std::set comparator

Yacoby's answer inspires me to write an adaptor for encapsulating the functor boilerplate.

template< class T, bool (*comp)( T const &, T const & ) >
class set_funcomp {
    struct ftor {
        bool operator()( T const &l, T const &r )
            { return comp( l, r ); }
    };
public:
    typedef std::set< T, ftor > t;
};

// usage

bool my_comparison( foo const &l, foo const &r );
set_funcomp< foo, my_comparison >::t boo; // just the way you want it!

Wow, I think that was worth the trouble!

How to make a round button?

  1. Use the Image Buttons and make the background as the image you want.
  2. Create the images from the android asset studio link -

" https://romannurik.github.io/AndroidAssetStudio/icons-launcher.html#foreground.type=image&foreground.space.trim=0&foreground.space.pad=0.25&foreColor=rgba(94%2C%20126%2C%20142%2C%200)&backColor=rgb(96%2C%20125%2C%20139)&crop=1&backgroundShape=circle&effects=none&name=ic_home "

and download it, extraxt it , inside that look for mipmap-hdpi folder.

  1. copy the image from the mipmap-hdpi folder and paste it in the drwable folder of your android project.

  2. Now set the background as that image.

Get size of an Iterable in Java

Why don't you simply use the size() method on your Collection to get the number of elements?

Iterator is just meant to iterate,nothing else.

How to get folder path for ClickOnce application

Assuming the question is about accessing files in the application folder after the ClickOnce (true == System.Deployment.ApplicationDeploy.IsNetworkDeployed) application is installed on the user's PC, their are three ways to get this folder by the application itself:

String path1 = System.AppDomain.CurrentDomain.BaseDirectory;
String path2 = System.IO.Directory.GetCurrentDirectory();    
String path3 = System.Reflection.Assembly.GetExecutingAssembly().CodeBase; //Remove the last path component, the executing assembly itself.

These work from VS IDE and from a deployed/installed ClickedOnce app, no "true == System.Deployment.ApplicationDeploy.IsNetworkDeployed" check required. ClickOnce picks up any files included in the Visual Studio 2017 project so really the application can access any and all deployed files using relative paths from within the application.

This is based on Windows 10 and Visual Studio 2017

How to get named excel sheets while exporting from SSRS

Put the tab name on the page header or group TableRow1 in your report so that it will appear in the "A1" position on each Excel sheet. Then run this macro in your Excel workbook.

Sub SelectSheet()
        For i = 1 To ThisWorkbook.Sheets.Count
        mysheet = "Sheet" & i
        On Error GoTo 10
        Sheets(mysheet).Select
        Set Target = Range("A1")
        If Target = "" Then Exit Sub
        On Error GoTo Badname
        ActiveSheet.Name = Left(Target, 31)
        GoTo 10
Badname:
        MsgBox "Please revise the entry in A1." & Chr(13) _
        & "It appears to contain one or more " & Chr(13) _
        & "illegal characters." & Chr(13)
        Range("A1").Activate
10
        Next i
End Sub

How to apply a CSS class on hover to dynamically generated submit buttons?

You have two options:

  1. Extend your .paging class definition:

    .paging:hover {
        border:1px solid #999;
        color:#000;
    }
    
  2. Use the DOM hierarchy to apply the CSS style:

    div.paginate input:hover {
        border:1px solid #999;
        color:#000;
    }
    

IOError: [Errno 13] Permission denied

IOError: [Errno 13] Permission denied: 'juliodantas2015.json'

tells you everything you need to know: though you successfully made your python program executable with your chmod, python can't open that juliodantas2015.json' file for writing. You probably don't have the rights to create new files in the folder you're currently in.

Calculate difference in keys contained in two Python dictionaries

here's a solution that can compare more than two dicts:

def diff_dict(dicts, default=None):
    diff_dict = {}
    # add 'list()' around 'd.keys()' for python 3 compatibility
    for k in set(sum([d.keys() for d in dicts], [])):
        # we can just use "values = [d.get(k, default) ..." below if 
        # we don't care that d1[k]=default and d2[k]=missing will
        # be treated as equal
        if any(k not in d for d in dicts):
            diff_dict[k] = [d.get(k, default) for d in dicts]
        else:
            values = [d[k] for d in dicts]
            if any(v != values[0] for v in values):
                diff_dict[k] = values
    return diff_dict

usage example:

import matplotlib.pyplot as plt
diff_dict([plt.rcParams, plt.rcParamsDefault, plt.matplotlib.rcParamsOrig])

Input from the keyboard in command line application

Another alternative is to link libedit for proper line editing (arrow keys, etc.) and optional history support. I wanted this for a project I'm starting and put together a basic example for how I set it up.

Usage from swift

let prompt: Prompt = Prompt(argv0: C_ARGV[0])

while (true) {
    if let line = prompt.gets() {
        print("You typed \(line)")
    }
}

ObjC wrapper to expose libedit

#import <histedit.h>

char* prompt(EditLine *e) {
    return "> ";
}

@implementation Prompt

EditLine* _el;
History* _hist;
HistEvent _ev;

- (instancetype) initWithArgv0:(const char*)argv0 {
    if (self = [super init]) {
        // Setup the editor
        _el = el_init(argv0, stdin, stdout, stderr);
        el_set(_el, EL_PROMPT, &prompt);
        el_set(_el, EL_EDITOR, "emacs");

        // With support for history
        _hist = history_init();
        history(_hist, &_ev, H_SETSIZE, 800);
        el_set(_el, EL_HIST, history, _hist);
    }

    return self;
}

- (void) dealloc {
    if (_hist != NULL) {
        history_end(_hist);
        _hist = NULL;
    }

    if (_el != NULL) {
        el_end(_el);
        _el = NULL;
    }
}

- (NSString*) gets {

    // line includes the trailing newline
    int count;
    const char* line = el_gets(_el, &count);

    if (count > 0) {
        history(_hist, &_ev, H_ENTER, line);

        return [NSString stringWithCString:line encoding:NSUTF8StringEncoding];
    }

    return nil;
}

@end

How to convert float to varchar in SQL Server

Based on molecular's answer:

DECLARE @F FLOAT = 1000000000.1234;
SELECT @F AS Original, CAST(FORMAT(@F, N'#.##############################') AS VARCHAR) AS Formatted;

SET @F = 823399066925.049
SELECT @F AS Original, CAST(@F AS VARCHAR) AS Formatted
UNION ALL SELECT @F AS Original, CONVERT(VARCHAR(128), @F, 128) AS Formatted
UNION ALL SELECT @F AS Original, CAST(FORMAT(@F, N'G') AS VARCHAR) AS Formatted;

SET @F = 0.502184537571209
SELECT @F AS Original, CAST(@F AS VARCHAR) AS Formatted
UNION ALL SELECT @F AS Original, CONVERT(VARCHAR(128), @F, 128) AS Formatted
UNION ALL SELECT @F AS Original, CAST(FORMAT(@F, N'G') AS VARCHAR) AS Formatted;

Git - how delete file from remote repository

  1. If you want to push a deleted file to remote

git add 'deleted file name'

git commit -m'message'

git push -u origin branch

  1. If you want to delete a file from remote and locally

git rm 'file name'

git commit -m'message'

git push -u origin branch

  1. If you want to delete a file from remote only

git rm --cached 'file name'

git commit -m'message'

git push -u origin branch

Using querySelectorAll to retrieve direct children

Good question. At the time it was asked, a universally-implemented way to do "combinator rooted queries" (as John Resig called them) did not exist.

Now the :scope pseudo-class has been introduced. It is not supported on [pre-Chrominum] versions of Edge or IE, but has been supported by Safari for a few years already. Using that, your code could become:

let myDiv = getElementById("myDiv");
myDiv.querySelectorAll(":scope > .foo");

Note that in some cases you can also skip .querySelectorAll and use other good old-fashioned DOM API features. For example, instead of myDiv.querySelectorAll(":scope > *") you could just write myDiv.children, for example.

Otherwise if you can't yet rely on :scope, I can't think of another way to handle your situation without adding more custom filter logic (e.g. find myDiv.getElementsByClassName("foo") whose .parentNode === myDiv), and obviously not ideal if you're trying to support one code path that really just wants to take an arbitrary selector string as input and a list of matches as output! But if like me you ended up asking this question simply because you got stuck thinking "all you had was a hammer" don't forget there are a variety of other tools the DOM offers too.

Split code over multiple lines in an R script

You are not breaking code over multiple lines, but rather a single identifier. There is a difference.

For your issue, try

R> setwd(paste("~/a/very/long/path/here",
               "/and/then/some/more",
               "/and/then/some/more",
               "/and/then/some/more", sep=""))

which also illustrates that it is perfectly fine to break code across multiple lines.

position fixed is not working

Double-check that you haven't enabled backface-visibility on any of the containing elements, as that will wreck position: fixed. For me, I was using a CSS3 animation library...

ORA-00972 identifier is too long alias column name

As others have referred, names in Oracle SQL must be less or equal to 30 characters. I would add that this rule applies not only to table names but to field names as well. So there you have it.

How to check the function's return value if true or false

you're comparing the result against a string ('false') not the built-in negative constant (false)

just use

if(ValidateForm() == false) {

or better yet

if(!ValidateForm()) {

also why are you calling validateForm twice?

how to configuring a xampp web server for different root directory

# Possible values for the Options directive are "None", "All",
# or any combination of:
#   Indexes Includes FollowSymLinks SymLinksifOwnerMatch ExecCGI MultiViews
#
# Note that "MultiViews" must be named *explicitly* --- "Options All"
# doesn't give it to you.
#
# The Options directive is both complicated and important.  Please see
# http://httpd.apache.org/docs/2.2/mod/core.html#options
# for more information.
#
Options Indexes FollowSymLinks Includes ExecCGI

#
# AllowOverride controls what directives may be placed in .htaccess files.
# It can be "All", "None", or any combination of the keywords:
#   Options FileInfo AuthConfig Limit
#
AllowOverride All

#
# Controls who can get stuff from this server.
#
Require all granted

Write above code inside following tags < Directory "c:\projects" > < / Directory > c:(you can add any directory d: e:) is drive where you have created your project folder.

Alias /projects "c:\projects"

Now you can access the pr0jects directory on your browser :

localhost/projects/

SQL Server convert string to datetime

For instance you can use

update tablename set datetimefield='19980223 14:23:05'
update tablename set datetimefield='02/23/1998 14:23:05'
update tablename set datetimefield='1998-12-23 14:23:05'
update tablename set datetimefield='23 February 1998 14:23:05'
update tablename set datetimefield='1998-02-23T14:23:05'

You need to be careful of day/month order since this will be language dependent when the year is not specified first. If you specify the year first then there is no problem; date order will always be year-month-day.

How to change mysql to mysqli?

The first thing to do would probably be to replace every mysql_* function call with its equivalent mysqli_*, at least if you are willing to use the procedural API -- which would be the easier way, considering you already have some code based on the MySQL API, which is a procedural one.

To help with that, the MySQLi Extension Function Summary is definitely something that will prove helpful.

For instance:

Note: For some functions, you may need to check the parameters carefully: Maybe there are some differences here and there -- but not that many, I'd say: both mysql and mysqli are based on the same library (libmysql ; at least for PHP <= 5.2)

For instance:

  • with mysql, you have to use the mysql_select_db once connected, to indicate on which database you want to do your queries
  • mysqli, on the other side, allows you to specify that database name as the fourth parameter to mysqli_connect.
  • Still, there is also a mysqli_select_db function that you can use, if you prefer.

Once you are done with that, try to execute the new version of your script... And check if everything works ; if not... Time for bug hunting ;-)

How to darken an image on mouseover?

How about this...

<style type="text/css">
    div.frame { background-color: #000; }
    img.pic:hover {
      opacity: .6;
      filter:alpha(opacity=60);
    }
</style>

<div class="frame">
    <img class="pic" src="path/to/image" />
</div>

How to get a list of installed android applications and pick one to run

I had a requirement to filter out the system apps which user do not really use(eg. "com.qualcomm.service", "update services", etc). Ultimately I added another condition to filter down the app list. I just checked whether the app has 'launcher intent'.

So, the resultant code looks like...

PackageManager pm = getPackageManager();
        List<ApplicationInfo> apps = pm.getInstalledApplications(PackageManager.GET_GIDS);

        for (ApplicationInfo app : apps) {
            if(pm.getLaunchIntentForPackage(app.packageName) != null) {
                // apps with launcher intent
                if((app.flags & ApplicationInfo.FLAG_UPDATED_SYSTEM_APP) != 0) {
                    // updated system apps

                } else if ((app.flags & ApplicationInfo.FLAG_SYSTEM) != 0) {
                    // system apps

                } else {
                    // user installed apps

                }
                appsList.add(app);
            }

        }

swift 3.0 Data to String?

let urlString = baseURL + currency

    if let url = URL(string: urlString){
        let session = URLSession(configuration: .default)        
        let task = session.dataTask(with: url){ (data, reponse, error) in
            if error != nil{
                print(error)
                return
            }


            let dataString = String(data: data!, encoding: .utf8)
            print(dataString)

        }

        task.resume()

    }

Enable remote connections for SQL Server Express 2012

One more thing to check is that you have spelled the named instance correctly!

This article is very helpful in troubleshooting connection problems: How to Troubleshoot Connecting to the SQL Server Database Engine

What is the instanceof operator in JavaScript?

On the question "When is it appropriate and when not?", my 2 cents:

instanceof is rarely useful in production code, but useful in tests where you want to assert that your code returns / creates objects of the correct types. By being explicit about the kinds of objects your code is returning / creating, your tests become more powerful as a tool for understanding and documenting your code.