Programs & Examples On #Webinvoke

WebInvoke - Indicates a service operation is logically an invoke operation and that it can be called by the REST programming model

Cannot set content-type to 'application/json' in jQuery.ajax

I recognized those screens, I'm using CodeFluentEntities, and I've got solution that worked for me as well.

I'm using that construction:

$.ajax({
   url: path,
   type: "POST",
   contentType: "text/plain",
   data: {"some":"some"}
}

as you can see, if I use

contentType: "",

or

contentType: "text/plain", //chrome

Everything works fine.

I'm not 100% sure that it's all that you need, cause I've also changed headers.

No connection could be made because the target machine actively refused it 127.0.0.1:3446

You don't have to restart the PC. Restart IIS instead.

Run -> 'cmd'(as admin) and type "iisreset"

How to comment and uncomment blocks of code in the Office VBA Editor

Have you checked MZTools?? It does a lot of cool stuff...

If I'm not wrong, one of the functionalities it offers is to set your own shortcuts.

java : convert float to String and String to float

This is a possible answer, this will also give the precise data, just need to change the decimal point in the required form.

public class TestStandAlone {

    /**
     * 

This method is to main

* @param args void */ public static void main(String[] args) { // TODO Auto-generated method stub try { Float f1=152.32f; BigDecimal roundfinalPrice = new BigDecimal(f1.floatValue()).setScale(2,BigDecimal.ROUND_HALF_UP); System.out.println("f1 --> "+f1); String s1=roundfinalPrice.toPlainString(); System.out.println("s1 "+s1); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } }

Output will be

f1 --> 152.32
s1 152.32

What is jQuery Unobtrusive Validation?

For clarification, here is a more detailed example demonstrating Form Validation using jQuery Validation Unobtrusive.

Both use the following JavaScript with jQuery:

  $("#commentForm").validate({
    submitHandler: function(form) {
      // some other code
      // maybe disabling submit button
      // then:
      alert("This is a valid form!");
//      form.submit();
    }
  });

The main differences between the two plugins are the attributes used for each approach.

jQuery Validation

Simply use the following attributes:

  • Set required if required
  • Set type for proper formatting (email, etc.)
  • Set other attributes such as size (min length, etc.)

Here's the form...

<form id="commentForm">
  <label for="form-name">Name (required, at least 2 characters)</label>
  <input id="form-name" type="text" name="form-name" class="form-control" minlength="2" required>
  <input type="submit" value="Submit">
</form>

jQuery Validation Unobtrusive

The following data attributes are needed:

  • data-msg-required="This is required."
  • data-rule-required="true/false"

Here's the form...

<form id="commentForm">
  <label for="form-x-name">Name (required, at least 2 characters)</label>
  <input id="form-x-name" type="text" name="name" minlength="2" class="form-control" data-msg-required="Name is required." data-rule-required="true">
  <input type="submit" value="Submit">
</form>

Based on either of these examples, if the form fields that are required have been filled, and they meet the additional attribute criteria, then a message will pop up notifying that all form fields are validated. Otherwise, there will be text near the offending form fields that indicates the error.

References: - jQuery Validation: https://jqueryvalidation.org/documentation/

Proxy Basic Authentication in C#: HTTP 407 error

You can use like this, it works!

        WebProxy proxy = new WebProxy
        {
            Address = new Uri(""),
            Credentials = new NetworkCredential("", "")
        };

        HttpClientHandler httpClientHandler = new HttpClientHandler
        {
            Proxy = proxy,
            UseProxy = true
        };

        HttpClient client = new HttpClient(httpClientHandler);

        HttpResponseMessage response = await client.PostAsync("...");

Round button with text and icon in flutter

Screenshot:

enter image description here

SizedBox.fromSize(
  size: Size(56, 56), // button width and height
  child: ClipOval(
    child: Material(
      color: Colors.orange, // button color
      child: InkWell(
        splashColor: Colors.green, // splash color
        onTap: () {}, // button pressed
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Icon(Icons.call), // icon
            Text("Call"), // text
          ],
        ),
      ),
    ),
  ),
)

How to parse XML to R data frame

You can try the code below:

# Load the packages required to read XML files.
library("XML")
library("methods")

# Convert the input xml file to a data frame.
xmldataframe <- xmlToDataFrame("input.xml")
print(xmldataframe)

Boto3 to download all files from a S3 Bucket

Amazon S3 does not have folders/directories. It is a flat file structure.

To maintain the appearance of directories, path names are stored as part of the object Key (filename). For example:

  • images/foo.jpg

In this case, the whole Key is images/foo.jpg, rather than just foo.jpg.

I suspect that your problem is that boto is returning a file called my_folder/.8Df54234 and is attempting to save it to the local filesystem. However, your local filesystem interprets the my_folder/ portion as a directory name, and that directory does not exist on your local filesystem.

You could either truncate the filename to only save the .8Df54234 portion, or you would have to create the necessary directories before writing files. Note that it could be multi-level nested directories.

An easier way would be to use the AWS Command-Line Interface (CLI), which will do all this work for you, eg:

aws s3 cp --recursive s3://my_bucket_name local_folder

There's also a sync option that will only copy new and modified files.

Why use String.Format?

Besides being a bit easier to read and adding a few more operators, it's also beneficial if your application is internationalized. A lot of times the variables are numbers or key words which will be in a different order for different languages. By using String.Format, your code can remain unchanged while different strings will go into resource files. So, the code would end up being

String.Format(resource.GetString("MyResourceString"), str1, str2, str3);

While your resource strings end up being

English: "blah blah {0} blah blah {1} blah {2}"

Russian: "{0} blet blet blet {2} blet {1}"

Where Russian may have different rules on how things get addressed so the order is different or sentence structure is different.

Open popup and refresh parent page on close popup

In my case I opened a pop up window on click on linkbutton in parent page. To refresh parent on closing child using

window.opener.location.reload();

in child window caused re open the child window (Might be because of View State I guess. Correct me If I m wrong). So I decided not to reload page in parent and load the the page again assigning same url to it.

To avoid popup opening again after closing pop up window this might help,

window.onunload = function(){
    window.opener.location = window.opener.location;};

How can I configure my makefile for debug and release builds?

If by configure release/build, you mean you only need one config per makefile, then it is simply a matter and decoupling CC and CFLAGS:

CFLAGS=-DDEBUG
#CFLAGS=-O2 -DNDEBUG
CC=g++ -g3 -gdwarf2 $(CFLAGS)

Depending on whether you can use gnu makefile, you can use conditional to make this a bit fancier, and control it from the command line:

DEBUG ?= 1
ifeq ($(DEBUG), 1)
    CFLAGS =-DDEBUG
else
    CFLAGS=-DNDEBUG
endif

.o: .c
    $(CC) -c $< -o $@ $(CFLAGS)

and then use:

make DEBUG=0
make DEBUG=1

If you need to control both configurations at the same time, I think it is better to have build directories, and one build directory / config.

Android: Tabs at the BOTTOM

I was having the same problem with android tabs when trying to place them on the bottom of the screen. My scenario was to not use a layout file and create the tabs in code, I was also looking to fire activities from each tab which seemed a bit too complex using other approaches so, here is the sample code to overcome the problem:

adding-tabs-in-android-and-placing-them

Npm Error - No matching version found for

try

npm install --force
npm install --legacy-peer-deps

notifyDataSetChanged example

You can use the runOnUiThread() method as follows. If you're not using a ListActivity, just adapt the code to get a reference to your ArrayAdapter.

final ArrayAdapter adapter = ((ArrayAdapter)getListAdapter());
runOnUiThread(new Runnable() {
    public void run() {
        adapter.notifyDataSetChanged();
    }
});

Can't connect to HTTPS site using cURL. Returns 0 length content instead. What can I do?

You should also try checking the error messages in curl_error(). You might need to do this once after each curl_* function.

http://www.php.net/curl_error

ALTER TABLE, set null in not null column, PostgreSQL 9.1

Execute the command in this format:

ALTER [ COLUMN ] column { SET | DROP } NOT NULL

Converting a generic list to a CSV string

I like a nice simple extension method

 public static string ToCsv(this List<string> itemList)
         {
             return string.Join(",", itemList);
         }

Then you can just call the method on the original list:

string CsvString = myList.ToCsv();

Cleaner and easier to read than some of the other suggestions.

how to detect search engine bots with php?

You can checkout if it's a search engine with this function :

<?php
function crawlerDetect($USER_AGENT)
{
$crawlers = array(
'Google' => 'Google',
'MSN' => 'msnbot',
      'Rambler' => 'Rambler',
      'Yahoo' => 'Yahoo',
      'AbachoBOT' => 'AbachoBOT',
      'accoona' => 'Accoona',
      'AcoiRobot' => 'AcoiRobot',
      'ASPSeek' => 'ASPSeek',
      'CrocCrawler' => 'CrocCrawler',
      'Dumbot' => 'Dumbot',
      'FAST-WebCrawler' => 'FAST-WebCrawler',
      'GeonaBot' => 'GeonaBot',
      'Gigabot' => 'Gigabot',
      'Lycos spider' => 'Lycos',
      'MSRBOT' => 'MSRBOT',
      'Altavista robot' => 'Scooter',
      'AltaVista robot' => 'Altavista',
      'ID-Search Bot' => 'IDBot',
      'eStyle Bot' => 'eStyle',
      'Scrubby robot' => 'Scrubby',
      'Facebook' => 'facebookexternalhit',
  );
  // to get crawlers string used in function uncomment it
  // it is better to save it in string than use implode every time
  // global $crawlers
   $crawlers_agents = implode('|',$crawlers);
  if (strpos($crawlers_agents, $USER_AGENT) === false)
      return false;
    else {
    return TRUE;
    }
}
?>

Then you can use it like :

<?php $USER_AGENT = $_SERVER['HTTP_USER_AGENT'];
  if(crawlerDetect($USER_AGENT)) return "no need to lang redirection";?>

Exception: Serialization of 'Closure' is not allowed

Apparently anonymous functions cannot be serialized.

Example

$function = function () {
    return "ABC";
};
serialize($function); // would throw error

From your code you are using Closure:

$callback = function () // <---------------------- Issue
{
    return 'ZendMail_' . microtime(true) . '.tmp';
};

Solution 1 : Replace with a normal function

Example

function emailCallback() {
    return 'ZendMail_' . microtime(true) . '.tmp';
}
$callback = "emailCallback" ;

Solution 2 : Indirect method call by array variable

If you look at http://docs.mnkras.com/libraries_23rdparty_2_zend_2_mail_2_transport_2file_8php_source.html

   public function __construct($options = null)
   63     {
   64         if ($options instanceof Zend_Config) {
   65             $options = $options->toArray();
   66         } elseif (!is_array($options)) {
   67             $options = array();
   68         }
   69 
   70         // Making sure we have some defaults to work with
   71         if (!isset($options['path'])) {
   72             $options['path'] = sys_get_temp_dir();
   73         }
   74         if (!isset($options['callback'])) {
   75             $options['callback'] = array($this, 'defaultCallback'); <- here
   76         }
   77 
   78         $this->setOptions($options);
   79     }

You can use the same approach to send the callback

$callback = array($this,"aMethodInYourClass");

Return empty cell from formula in Excel

Yes, it is possible.

It is possible to have a formula returning a trueblank if a condition is met. It passes the test of the ISBLANK formula. The only inconvenience is that when the condition is met, the formula will evaporate, and you will have to retype it. You can design a formula immune to self-destruction by making it return the result to the adjacent cell. Yes, it is also possible. I refer you to this solution at the end of my answer.

enter image description here

All you need is to set up a named range, say GetTrueBlank, and you will be able to use the following pattern just like in your question:

=IF(A1 = "Hello world", GetTrueBlank, A1)

Step 1. Put this code in Module of VBA.

Function Delete_UDF(rng)
    ThisWorkbook.Application.Volatile
    rng.Value = ""
End Function

Step 2. In Sheet1 in A1 cell add named range GetTrueBlank with the following formula:

=EVALUATE("Delete_UDF("&CELL("address",Sheet1!A1)&")")

enter image description here

That's it. There are no further steps. Just use self-annihilating formula. Put in the cell, say B2, the following formula:

=IF(A2=0,GetTrueBlank,A2)

The above formula in B2 will evaluate to trueblank, if you type 0 in A2.

You can download a demonstration file here.

In the example above, evaluating the formula to trueblank results in an empty cell. Checking the cell with ISBLANK formula results positively in TRUE. This is hara-kiri. The formula disappears from the cell when a condition is met. The goal is reached, although you probably might want the formula not to disappear.

You may modify the formula to return the result in the adjacent cell so that the formula will not kill itself. See how to get UDF result in the adjacent cell.

adjacent cell

I have come across the examples of getting a trueblank as a formula result revealed by The FrankensTeam here: https://sites.google.com/site/e90e50/excel-formula-to-change-the-value-of-another-cell

How to use the toString method in Java?

the toString() converts the specified object to a string value.

Passing an array to a query using a WHERE clause

Below is the method I have used, using PDO with named placeholders for other data. To overcome SQL injection I am filtering the array to accept only the values that are integers and rejecting all others.

$owner_id = 123;
$galleries = array(1,2,5,'abc');

$good_galleries = array_filter($chapter_arr, 'is_numeric');

$sql = "SELECT * FROM galleries WHERE owner=:OWNER_ID AND id IN ($good_galleries)";
$stmt = $dbh->prepare($sql);
$stmt->execute(array(
    "OWNER_ID" => $owner_id,
));

$data = $stmt->fetchAll(PDO::FETCH_ASSOC);

Choice between vector::resize() and vector::reserve()

reserve when you do not want the objects to be initialized when reserved. also, you may prefer to logically differentiate and track its count versus its use count when you resize. so there is a behavioral difference in the interface - the vector will represent the same number of elements when reserved, and will be 100 elements larger when resized in your scenario.

Is there any better choice in this kind of scenario?

it depends entirely on your aims when fighting the default behavior. some people will favor customized allocators -- but we really need a better idea of what it is you are attempting to solve in your program to advise you well.

fwiw, many vector implementations will simply double the allocated element count when they must grow - are you trying to minimize peak allocation sizes or are you trying to reserve enough space for some lock free program or something else?

What's the difference between & and && in MATLAB?

As already mentioned by others, & is a logical AND operator and && is a short-circuit AND operator. They differ in how the operands are evaluated as well as whether or not they operate on arrays or scalars:

  • & (AND operator) and | (OR operator) can operate on arrays in an element-wise fashion.
  • && and || are short-circuit versions for which the second operand is evaluated only when the result is not fully determined by the first operand. These can only operate on scalars, not arrays.

Forward declaration of a typedef in C++

To "fwd declare a typedef" you need to fwd declare a class or a struct and then you can typedef declared type. Multiple identical typedefs are acceptable by compiler.

long form:

class MyClass;
typedef MyClass myclass_t;

short form:

typedef class MyClass myclass_t;

Making the main scrollbar always visible

I was able to get this to work by adding it to the body tag. Was nicer for me because I don't have anything on the html element.

body {
    overflow-y: scroll;
}

Android + Pair devices via bluetooth programmatically

The Best way is do not use any pairing code. Instead of onClick go to other function or other class where You create the socket using UUID.
Android automatically pops up for pairing if already not paired.

or see this link for better understanding

Below is code for the same:

private OnItemClickListener mDeviceClickListener = new OnItemClickListener() {
    public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {
        // Cancel discovery because it's costly and we're about to connect
        mBtAdapter.cancelDiscovery();

        // Get the device MAC address, which is the last 17 chars in the View
        String info = ((TextView) v).getText().toString();
        String address = info.substring(info.length() - 17);

        // Create the result Intent and include the MAC address
        Intent intent = new Intent();
        intent.putExtra(EXTRA_DEVICE_ADDRESS, address);

        // Set result and finish this Activity
        setResult(Activity.RESULT_OK, intent);

      // **add this 2 line code** 
       Intent myIntent = new Intent(view.getContext(), Connect.class);
        startActivityForResult(myIntent, 0);

        finish();
    }
};

Connect.java file is :

public class Connect extends Activity {
private static final String TAG = "zeoconnect";
private ByteBuffer localByteBuffer;
 private InputStream in;
 byte[] arrayOfByte = new byte[4096];
 int bytes;


  public BluetoothDevice mDevice;



@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.connect);



              try {
                setup();
            } catch (ZeoMessageException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (ZeoMessageParseException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            }

 private void setup() throws ZeoMessageException, ZeoMessageParseException  {
    // TODO Auto-generated method stub

        getApplicationContext().registerReceiver(receiver,
                    new IntentFilter(BluetoothDevice.ACTION_ACL_CONNECTED));
        getApplicationContext().registerReceiver(receiver,
                    new IntentFilter(BluetoothDevice.ACTION_ACL_DISCONNECTED));

            BluetoothDevice zee = BluetoothAdapter.getDefaultAdapter().
                    getRemoteDevice("**:**:**:**:**:**");// add device mac adress

            try {
                sock = zee.createRfcommSocketToServiceRecord(
                         UUID.fromString("*******************")); // use unique UUID
            } catch (IOException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }

            Log.d(TAG, "++++ Connecting");
            try {
                sock.connect();
            } catch (IOException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }
            Log.d(TAG, "++++ Connected");


            try {
                in = sock.getInputStream();
            } catch (IOException e1) {
                // TODO Auto-generated catch block
                e1.printStackTrace();
            }

              Log.d(TAG, "++++ Listening...");

              while (true) {

                  try {
                      bytes = in.read(arrayOfByte);
                      Log.d(TAG, "++++ Read "+ bytes +" bytes");  
                    } catch (IOException e1) {
                        // TODO Auto-generated catch block
                        e1.printStackTrace();
                }
                        Log.d(TAG, "++++ Done: test()"); 

                        }} 




 private static final LogBroadcastReceiver receiver = new LogBroadcastReceiver();
    public static class LogBroadcastReceiver extends BroadcastReceiver {

        @Override
        public void onReceive(Context paramAnonymousContext, Intent paramAnonymousIntent) {
            Log.d("ZeoReceiver", paramAnonymousIntent.toString());
            Bundle extras = paramAnonymousIntent.getExtras();
            for (String k : extras.keySet()) {
                Log.d("ZeoReceiver", "    Extra: "+ extras.get(k).toString());
            }
        }


    };

    private BluetoothSocket sock;
    @Override
    public void onDestroy() {
        getApplicationContext().unregisterReceiver(receiver);
        if (sock != null) {
            try {
                sock.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        super.onDestroy();
    }
 }

Get an image extension from an uploaded file in Laravel

 //working code from laravel 5.2

 public function store(Request $request)
 {
          $file = $request->file('file');
            if($file)
            {
                    $extension =  $file->clientExtension();
            }
            echo $extension;
 }

Access-Control-Allow-Origin and Angular.js $http

Try with this:

          $.ajax({
              type: 'POST',
              url: URL,
              defaultHeaders: {
                  'Content-Type': 'application/json',
                  "Access-Control-Allow-Origin": "*",
                  'Accept': 'application/json'
               },

              data: obj,
              dataType: 'json',
              success: function (response) {
            //    BindTableData();
                console.log("success ");
                alert(response);
              },
              error: function (xhr) {
                console.log("error ");
                console.log(xhr);
              }
          });

How do I provide a username and password when running "git clone [email protected]"?

In the comments of @Bassetassen's answer, @plosco mentioned that you can use git clone https://<token>@github.com/username/repository.git to clone from GitHub at the very least. I thought I would expand on how to do that, in case anyone comes across this answer like I did while trying to automate some cloning.

GitHub has a very handy guide on how to do this, but it doesn't cover what to do if you want to include it all in one line for automation purposes. It warns that adding the token to the clone URL will store it in plaintext in .git/config. This is obviously a security risk for almost every use case, but since I plan on deleting the repo and revoking the token when I'm done, I don't care.

1. Create a Token

GitHub has a whole guide here on how to get a token, but here's the TL;DR.

  1. Go to Settings > Developer Settings > Personal Access Tokens (here's a direct link)
  2. Click "Generate a New Token" and enter your password again. (here's another direct link)
  3. Set a description/name for it, check the "repo" permission and hit the "Generate token" button at the bottom of the page.
  4. Copy your new token before you leave the page

2. Clone the Repo

Same as the command @plosco gave, git clone https://<token>@github.com/<username>/<repository>.git, just replace <token>, <username> and <repository> with whatever your info is.

If you want to clone it to a specific folder, just insert the folder address at the end like so: git clone https://<token>@github.com/<username>/<repository.git> <folder>, where <folder> is, you guessed it, the folder to clone it to! You can of course use ., .., ~, etc. here like you can elsewhere.

3. Leave No Trace

Not all of this may be necessary, depending on how sensitive what you're doing is.

  • You probably don't want to leave that token hanging around if you have no intentions of using it for some time, so go back to the tokens page and hit the delete button next to it.
  • If you don't need the repo again, delete it rm -rf <folder>.
  • If do need the repo again, but don't need to automate it again, you can remove the remote by doing git remote remove origin or just remove the token by running git remote set-url origin https://github.com/<username>/<repository.git>.
  • Clear your bash history to make sure the token doesn't stay logged there. There are many ways to do this, see this question and this question. However, it may be easier to just prepend all the above commands with a space in order to prevent them being stored to begin with.

Note that I'm no pro, so the above may not be secure in the sense that no trace would be left for any sort of forensic work.

char initial value in Java

Either you initialize the variable to something

char retChar = 'x';

or you leave it automatically initialized, which is

char retChar = '\0';

an ascii 0, the same as

char retChar = (char) 0;

What can one initialize char values to?

Sounds undecided between automatic initialisation, which means, you have no influence, or explicit initialisation. But you cannot change the default.

Append an empty row in dataframe using pandas

You can also use:

your_dataframe.insert(loc=0, value=np.nan, column="")

where loc is your empty row index.

How to hide Android soft keyboard on EditText

weekText = (EditText) layout.findViewById(R.id.weekEditText);
weekText.setInputType(InputType.TYPE_NULL);

Wait one second in running program

Is it pausing, but you don't see your red color appear in the cell? Try this:

dataGridView1.Rows[x1].Cells[y1].Style.BackColor = System.Drawing.Color.Red;
dataGridView1.Refresh();
System.Threading.Thread.Sleep(1000);

npm WARN ... requires a peer of ... but none is installed. You must install peer dependencies yourself

"A requires a peer of B but none was installed". Consider it as "A requires one of B's peers but that peer was not installed and we're not telling you which of B's peers you need."

The automatic installation of peer dependencies was explicitly removed with npm 3.

NPM Blog

Release notes of v3

So you cannot install peer dependencies automatically with npm 3 and upwards.

Updated Solution:

Use following for each peer dependency to install that and remove the error

npm install --save-dev xxxxx

Deprecated Solution:

  1. You can use npm-install-peers to find and install required peer dependencies.

    npm install -g npm-install-peers

    npm-install-peers

  2. If you are getting this error after updating any package's version then remove node_modules directory and reinstall packages by npm install or npm cache clean and npm install.

How to change the window title of a MATLAB plotting figure?

You need to set figure properties.

At the very beginning of the script, call

figure('name','something else')

Calling figure is a good thing, anyway, because without it, you always plot into the same window, and sometimes you may want to compare two windows side-by-side.

Alternatively, you can store the figure's handle by calling

figH = figure;

so that you can later change the figure properties to your liking (the 'numberTitle' property setting eliminates the "figure X" text)

set(figH,'Name','something else','NumberTitle','off')

Have a look at the figure properties in the MATLAB documentation to see what else you can change if you want.

What is the command to truncate a SQL Server log file?

Another option altogether is to detach the database via Management Studio. Then simply delete the log file, or rename it and delete later.

Back in Management Studio attach the database again. In the attach window remove the log file from list of files.

The DB attaches and creates a new empty log file. After you check everything is all right, you can delete the renamed log file.

You probably ought not use this for production databases.

What HTTP traffic monitor would you recommend for Windows?

Fiddler is great when you are only interested in the http(s) side of the communications. It is also very useful when you are trying to inspect inside a https stream.

Can't use SURF, SIFT in OpenCV

I think this is far from the "correct" way to do it (the "correct" way on Ubuntu seems to be to stick to a broken and/or outdated OpenCV), but for me building opencv-2.4.6.1 from source brings back cv2.SIFT and cv2.SURF.

Steps:

  1. Download opencv-2.4.6.1.tar.gz from opencv.org.
  2. Extract the source:

    tar -xf opencv-2.4.6.1.tar.gz -C /tmp
    
  3. Configure the source. This will tell OpenCV to install into .opencv-2.4.6.1 in your home directory:

    cmake -D CMAKE_BUILD_TYPE=RELEASE \
          -D BUILD_PYTHON_SUPPORT=ON \
          -D WITH_XINE=ON \
          -D WITH_OPENGL=ON \
          -D WITH_TBB=ON \
          -D BUILD_EXAMPLES=ON \
          -D BUILD_NEW_PYTHON_SUPPORT=ON \
          -D WITH_V4L=ON \
          -D CMAKE_INSTALL_PREFIX=~/.opencv-2.4.6.1 \
          /tmp/opencv-2.4.6.1
    
  4. Build and install:

    cd /tmp/opencv-2.4.6.1
    make -j4
    make install
    
  5. Set PYTHONPATH (this works in bash, I have no clue about other shells):

    export PYTHONPATH=~/.opencv-2.4.6.1/lib/python2.7/dist-packages
    

Now if I start python and import cv2 (for me, this produces a gnome-keyring warning), I have cv2.SIFT and cv2.SURF available.

Table cell widths - fixing width, wrapping/truncating long words

As long as you fix the width of the table itself and set the table-layout property, this is pretty simple :

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <style type="text/css">
        td { width: 30px; overflow: hidden; }
        table { width : 90px; table-layout: fixed; }
    </style>
</head>
<body>

    <table border="2">
        <tr>
            <td>word</td>
            <td>two words</td>
            <td>onereallylongword</td>

        </tr>
    </table>
</body>
</html>

I've tested this in IE6 and 7 and it seems to work fine.

java: HashMap<String, int> not working

int is a primitive type, you can read what does mean a primitive type in java here, and a Map is an interface that has to objects as input:

public interface Map<K extends Object, V extends Object>

object means a class, and it means also that you can create an other class that exends from it, but you can not create a class that exends from int. So you can not use int variable as an object. I have tow solutions for your problem:

Map<String, Integer> map = new HashMap<>();

or

Map<String, int[]> map = new HashMap<>();
int x = 1;

//put x in map
int[] x_ = new int[]{x};
map.put("x", x_);

//get the value of x
int y = map.get("x")[0];

git reset --hard HEAD leaves untracked files behind

You might have done a soft reset at some point, you can solve this problem by doing

git add .
git reset --hard HEAD~100
git pull

How to use curl to get a GET request exactly same as using Chrome?

Check the HTTP headers that chrome is sending with the request (Using browser extension or proxy) then try sending the same headers with CURL - Possibly one at a time till you figure out which header(s) makes the request work.

curl -A [user-agent] -H [headers] "http://something.com/api"

How to make a div 100% height of the browser window

This stuff will resize height of content automatically according to your browser. I hope this will work for you. Just try this example given below.

You have to set up only height:100%.

_x000D_
_x000D_
html,body {_x000D_
  height: 100%;_x000D_
  margin: 0;_x000D_
}_x000D_
.content {_x000D_
  height: 100%;_x000D_
  min-height: 100%;_x000D_
  position: relative;_x000D_
}_x000D_
.content-left {_x000D_
  height: auto;_x000D_
  min-height: 100%;_x000D_
  float: left;_x000D_
  background: #ddd;_x000D_
  width: 50%;_x000D_
  position: relative;_x000D_
}_x000D_
_x000D_
#one {_x000D_
  background: url(http://cloud.niklausgerber.com/1a2n2I3J1h0M/red.png) center center no-repeat scroll  #aaa;_x000D_
  width: 50%;_x000D_
  position: relative;_x000D_
  float: left;_x000D_
}_x000D_
_x000D_
#two {_x000D_
 background: url(http://cloud.niklausgerber.com/1b0r2D2Z1y0J/dark-red.png) center center no-repeat scroll #520E24;_x000D_
  width: 50%;_x000D_
  float: left;_x000D_
  position: relative;_x000D_
  overflow-y: scroll;_x000D_
}
_x000D_
<div class='content' id='one'></div>_x000D_
<div class='content-left' id='two'></div>
_x000D_
_x000D_
_x000D_

How to parse JSON and access results

Try:

$result = curl_exec($cURL);
$result = json_decode($result,true);

Now you can access MessageID from $result['MessageID'].

As for the database, it's simply using a query like so:

INSERT INTO `tableName`(`Cancelled`,`Queued`,`SMSError`,`SMSIncommingMessage`,`Sent`,`SentDateTime`) VALUES('?','?','?','?','?');

Prepared.

How to merge multiple dicts with same key or different key?

Python 3.x Update

From Eli Bendersky answer:

Python 3 removed dict.iteritems use dict.items instead. See Python wiki: https://wiki.python.org/moin/Python3.0

from collections import defaultdict

dd = defaultdict(list)

for d in (d1, d2):
    for key, value in d.items():
        dd[key].append(value)

Pipe to/from the clipboard in Bash script

From this thread, there is an option which does not require installing any gclip/xclip/xsel third-party software.

A perl script (since perl is usually always installed)

use Win32::Clipboard;
print Win32::Clipboard::GetText();

jQuery checkbox onChange

$('input[type=checkbox]').change(function () {
    alert('changed');
});

How to secure the ASP.NET_SessionId cookie?

Here is a code snippet taken from a blog article written by Anubhav Goyal:

// this code will mark the forms authentication cookie and the
// session cookie as Secure.
if (Response.Cookies.Count > 0)
{
    foreach (string s in Response.Cookies.AllKeys)
    {
        if (s == FormsAuthentication.FormsCookieName || "asp.net_sessionid".Equals(s, StringComparison.InvariantCultureIgnoreCase))
        {
             Response.Cookies[s].Secure = true;
        }
    }
}

Adding this to the EndRequest event handler in the global.asax should make this happen for all page calls.

Note: An edit was proposed to add a break; statement inside a successful "secure" assignment. I've rejected this edit based on the idea that it would only allow 1 of the cookies to be forced to secure and the second would be ignored. It is not inconceivable to add a counter or some other metric to determine that both have been secured and to break at that point.

how do I create an infinite loop in JavaScript

You can also use a while loop:

while (true) {
    //your code
}

What does <![CDATA[]]> in XML mean?

It's used to contain data which could otherwise be seen as xml because it contains certain characters.

This way the data inside will be displayed, but not interpreted.

Detect Browser Language in PHP

The existing answers are a little too verbose so I created this smaller, auto-matching version.

function prefered_language(array $available_languages, $http_accept_language) {

    $available_languages = array_flip($available_languages);

    $langs;
    preg_match_all('~([\w-]+)(?:[^,\d]+([\d.]+))?~', strtolower($http_accept_language), $matches, PREG_SET_ORDER);
    foreach($matches as $match) {

        list($a, $b) = explode('-', $match[1]) + array('', '');
        $value = isset($match[2]) ? (float) $match[2] : 1.0;

        if(isset($available_languages[$match[1]])) {
            $langs[$match[1]] = $value;
            continue;
        }

        if(isset($available_languages[$a])) {
            $langs[$a] = $value - 0.1;
        }

    }
    arsort($langs);

    return $langs;
}

And the sample usage:

//$_SERVER["HTTP_ACCEPT_LANGUAGE"] = 'en-us,en;q=0.8,es-cl;q=0.5,zh-cn;q=0.3';

// Languages we support
$available_languages = array("en", "zh-cn", "es");

$langs = prefered_language($available_languages, $_SERVER["HTTP_ACCEPT_LANGUAGE"]);

/* Result
Array
(
    [en] => 0.8
    [es] => 0.4
    [zh-cn] => 0.3
)*/

Full gist source here

How to return a custom object from a Spring Data JPA GROUP BY query

define a custom pojo class say sureveyQueryAnalytics and store the query returned value in your custom pojo class

@Query(value = "select new com.xxx.xxx.class.SureveyQueryAnalytics(s.answer, count(sv)) from Survey s group by s.answer")
List<SureveyQueryAnalytics> calculateSurveyCount();

PHP: How to get current time in hour:minute:second?

You can combine both in the same date function call

date("d-m-Y H:i:s");  

Printing an array in C++?

Most of the libraries commonly used in C++ can't print arrays, per se. You'll have to loop through it manually and print out each value.

Printing arrays and dumping many different kinds of objects is a feature of higher level languages.

Call php function from JavaScript

PHP is evaluated at the server; javascript is evaluated at the client/browser, thus you can't call a PHP function from javascript directly. But you can issue an HTTP request to the server that will activate a PHP function, with AJAX.

Flatten nested dictionaries, compressing keys

Davoud's solution is very nice but doesn't give satisfactory results when the nested dict also contains lists of dicts, but his code be adapted for that case:

def flatten_dict(d):
    items = []
    for k, v in d.items():
        try:
            if (type(v)==type([])): 
                for l in v: items.extend(flatten_dict(l).items())
            else: 
                items.extend(flatten_dict(v).items())
        except AttributeError:
            items.append((k, v))
    return dict(items)

How to kill a process running on particular port in Linux?

You can use the lsof command. Let port number like here is 8090

lsof -i:8090

This command returns a list of open processes on this port.

Something like…

COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
ssh 75782 eoin 5u IPv6 0x01c1c234 0t0 TCP localhost:8090 (LISTEN)

To free the port, kill the process using it(the process id is 75782)…

kill -9 75782

This one worked for me. here is the link from the original post: link

What is the difference between a Relational and Non-Relational Database?

Hmm, not quite sure what your question is.

In the title you ask about Databases (DB), whereas in the body of your text you ask about Database Management Systems (DBMS). The two are completely different and require different answers.

A DBMS is a tool that allows you to access a DB.

Other than the data itself, a DB is the concept of how that data is structured.

So just like you can program with Oriented Object methodology with a non-OO powered compiler, or vice-versa, so can you set-up a relational database without an RDBMS or use an RDBMS to store non-relational data.

I'll focus on what Relational Database (RDB) means and leave the discussion about what systems do to others.

A relational database (the concept) is a data structure that allows you to link information from different 'tables', or different types of data buckets. A data bucket must contain what is called a key or index (that allows to uniquely identify any atomic chunk of data within the bucket). Other data buckets may refer to that key so as to create a link between their data atoms and the atom pointed to by the key.

A non-relational database just stores data without explicit and structured mechanisms to link data from different buckets to one another.

As to implementing such a scheme, if you have a paper file with an index and in a different paper file you refer to the index to get at the relevant information, then you have implemented a relational database, albeit quite a simple one. So you see that you do not even need a computer (of course it can become tedious very quickly without one to help), similarly you do not need an RDBMS, though arguably an RDBMS is the right tool for the job. That said there are variations as to what the different tools out there can do so choosing the right tool for the job may not be all that straightforward.

I hope this is layman terms enough and is helpful to your understanding.

How to list all the roles existing in Oracle database?

all_roles.sql

SELECT SUBSTR(TRIM(rtp.role),1,12)          AS ROLE
     , SUBSTR(rp.grantee,1,16)              AS GRANTEE
     , SUBSTR(TRIM(rtp.privilege),1,12)     AS PRIVILEGE
     , SUBSTR(TRIM(rtp.owner),1,12)         AS OWNER
     , SUBSTR(TRIM(rtp.table_name),1,28)    AS TABLE_NAME
     , SUBSTR(TRIM(rtp.column_name),1,20)   AS COLUMN_NAME
     , SUBSTR(rtp.common,1,4)               AS COMMON
     , SUBSTR(rtp.grantable,1,4)            AS GRANTABLE
     , SUBSTR(rp.default_role,1,16)         AS DEFAULT_ROLE
     , SUBSTR(rp.admin_option,1,4)          AS ADMIN_OPTION
  FROM role_tab_privs rtp
  LEFT JOIN dba_role_privs rp
    ON (rtp.role = rp.granted_role)
 WHERE ('&1' IS NULL OR UPPER(rtp.role) LIKE UPPER('%&1%'))
   AND ('&2' IS NULL OR UPPER(rp.grantee) LIKE UPPER('%&2%'))
   AND ('&3' IS NULL OR UPPER(rtp.table_name) LIKE UPPER('%&3%'))
   AND ('&4' IS NULL OR UPPER(rtp.owner) LIKE UPPER('%&4%'))
 ORDER BY 1
        , 2
        , 3
        , 4
;

Usage

SQLPLUS> @all_roles '' '' '' '' '' ''
SQLPLUS> @all_roles 'somerol' '' '' '' '' ''
SQLPLUS> @all_roles 'roler' 'username' '' '' '' ''
SQLPLUS> @all_roles '' '' 'part-of-database-package-name' '' '' ''
etc.

Using Pandas to pd.read_excel() for multiple worksheets of the same workbook

There are a few options:

Read all sheets directly into an ordered dictionary.

import pandas as pd

# for pandas version >= 0.21.0
sheet_to_df_map = pd.read_excel(file_name, sheet_name=None)

# for pandas version < 0.21.0
sheet_to_df_map = pd.read_excel(file_name, sheetname=None)

Read the first sheet directly into dataframe

df = pd.read_excel('excel_file_path.xls')
# this will read the first sheet into df

Read the excel file and get a list of sheets. Then chose and load the sheets.

xls = pd.ExcelFile('excel_file_path.xls')

# Now you can list all sheets in the file
xls.sheet_names
# ['house', 'house_extra', ...]

# to read just one sheet to dataframe:
df = pd.read_excel(file_name, sheetname="house")

Read all sheets and store it in a dictionary. Same as first but more explicit.

# to read all sheets to a map
sheet_to_df_map = {}
for sheet_name in xls.sheet_names:
    sheet_to_df_map[sheet_name] = xls.parse(sheet_name)
    # you can also use sheet_index [0,1,2..] instead of sheet name.

Thanks @ihightower for pointing it out way to read all sheets and @toto_tico for pointing out the version issue.

sheetname : string, int, mixed list of strings/ints, or None, default 0 Deprecated since version 0.21.0: Use sheet_name instead Source Link

Best way to do a split pane in HTML

Here is my lightweight vanilla JavaScript approach, using Flexbox:

http://codepen.io/lingtalfi/pen/zoNeJp

It was tested successfully in Google Chrome 54, Firefox 50, Safari 10, don't know about other browsers.

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.rawgit.com/lingtalfi/simpledrag/master/simpledrag.js"></script>

    <style type="text/css">

        html, body {
            height: 100%;
        }

        .panes-container {
            display: flex;
            width: 100%;
            overflow: hidden;
        }

        .left-pane {
            width: 18%;
            background: #ccc;
        }

        .panes-separator {
            width: 2%;
            background: red;
            position: relative;
            cursor: col-resize;
        }

        .right-pane {
            flex: auto;
            background: #eee;
        }

        .panes-container,
        .panes-separator,
        .left-pane,
        .right-pane {
            margin: 0;
            padding: 0;
            height: 100%;
        }

    </style>

</head>

<body>

<div class="panes-container">
    <div class="left-pane" id="left-pane">
        <p>I'm the left pane</p>
        <ul>
            <li><a href="#">Item 1</a></li>
            <li><a href="#">Item 2</a></li>
            <li><a href="#">Item 3</a></li>
        </ul>
    </div>
    <div class="panes-separator" id="panes-separator"></div>
    <div class="right-pane" id="right-pane">
        <p>And I'm the right pane</p>
        <p>
            Lorem ipsum dolor sit amet, consectetur adipisicing elit. A accusantium at cum cupiditate dolorum, eius eum
            eveniet facilis illum maiores molestiae necessitatibus optio possimus sequi sunt, vel voluptate. Asperiores,
            voluptate!
        </p>
    </div>
</div>


<script>


    var leftPane = document.getElementById('left-pane');
    var rightPane = document.getElementById('right-pane');
    var paneSep = document.getElementById('panes-separator');

    // The script below constrains the target to move horizontally between a left and a right virtual boundaries.
    // - the left limit is positioned at 10% of the screen width
    // - the right limit is positioned at 90% of the screen width
    var leftLimit = 10;
    var rightLimit = 90;


    paneSep.sdrag(function (el, pageX, startX, pageY, startY, fix) {

        fix.skipX = true;

        if (pageX < window.innerWidth * leftLimit / 100) {
            pageX = window.innerWidth * leftLimit / 100;
            fix.pageX = pageX;
        }
        if (pageX > window.innerWidth * rightLimit / 100) {
            pageX = window.innerWidth * rightLimit / 100;
            fix.pageX = pageX;
        }

        var cur = pageX / window.innerWidth * 100;
        if (cur < 0) {
            cur = 0;
        }
        if (cur > window.innerWidth) {
            cur = window.innerWidth;
        }


        var right = (100-cur-2);
        leftPane.style.width = cur + '%';
        rightPane.style.width = right + '%';

    }, null, 'horizontal');


</script>

</body>
</html>

This HTML code depends on the simpledrag vanilla JavaScript lightweight library (less than 60 lines of code).

Scatter plot and Color mapping in Python

Subplot Colorbar

For subplots with scatter, you can trick a colorbar onto your axes by building the "mappable" with the help of a secondary figure and then adding it to your original plot.

As a continuation of the above example:

import numpy as np
import matplotlib.pyplot as plt

x = np.arange(10)
y = x
t = x
fig, (ax1, ax2) = plt.subplots(1, 2)
ax1.scatter(x, y, c=t, cmap='viridis')
ax2.scatter(x, y, c=t, cmap='viridis_r')


# Build your secondary mirror axes:
fig2, (ax3, ax4) = plt.subplots(1, 2)

# Build maps that parallel the color-coded data
# NOTE 1: imshow requires a 2-D array as input
# NOTE 2: You must use the same cmap tag as above for it match
map1 = ax3.imshow(np.stack([t, t]),cmap='viridis')
map2 = ax4.imshow(np.stack([t, t]),cmap='viridis_r')

# Add your maps onto your original figure/axes
fig.colorbar(map1, ax=ax1)
fig.colorbar(map2, ax=ax2)
plt.show()

Scatter subplots with COLORBAR

Note that you will also output a secondary figure that you can ignore.

Reading all files in a directory, store them in objects, and send the object

This is a modern Promise version of the previous one, using a Promise.all approach to resolve all promises when all files have been read:

/**
 * Promise all
 * @author Loreto Parisi (loretoparisi at gmail dot com)
 */
function promiseAllP(items, block) {
    var promises = [];
    items.forEach(function(item,index) {
        promises.push( function(item,i) {
            return new Promise(function(resolve, reject) {
                return block.apply(this,[item,index,resolve,reject]);
            });
        }(item,index))
    });
    return Promise.all(promises);
} //promiseAll

/**
 * read files
 * @param dirname string
 * @return Promise
 * @author Loreto Parisi (loretoparisi at gmail dot com)
 * @see http://stackoverflow.com/questions/10049557/reading-all-files-in-a-directory-store-them-in-objects-and-send-the-object
 */
function readFiles(dirname) {
    return new Promise((resolve, reject) => {
        fs.readdir(dirname, function(err, filenames) {
            if (err) return reject(err);
            promiseAllP(filenames,
            (filename,index,resolve,reject) =>  {
                fs.readFile(path.resolve(dirname, filename), 'utf-8', function(err, content) {
                    if (err) return reject(err);
                    return resolve({filename: filename, contents: content});
                });
            })
            .then(results => {
                return resolve(results);
            })
            .catch(error => {
                return reject(error);
            });
        });
  });
}

How to Use It:

Just as simple as doing:

readFiles( EMAIL_ROOT + '/' + folder)
.then(files => {
    console.log( "loaded ", files.length );
    files.forEach( (item, index) => {
        console.log( "item",index, "size ", item.contents.length);
    });
})
.catch( error => {
    console.log( error );
});

Supposed that you have another list of folders you can as well iterate over this list, since the internal promise.all will resolve each of then asynchronously:

var folders=['spam','ham'];
folders.forEach( folder => {
    readFiles( EMAIL_ROOT + '/' + folder)
    .then(files => {
        console.log( "loaded ", files.length );
        files.forEach( (item, index) => {
            console.log( "item",index, "size ", item.contents.length);
        });
    })
    .catch( error => {
        console.log( error );
    });
});

How it Works

The promiseAll does the magic. It takes a function block of signature function(item,index,resolve,reject), where item is the current item in the array, index its position in the array, and resolve and reject the Promise callback functions. Each promise will be pushed in a array at the current index and with the current item as arguments through a anonymous function call:

promises.push( function(item,i) {
        return new Promise(function(resolve, reject) {
            return block.apply(this,[item,index,resolve,reject]);
        });
    }(item,index))

Then all promises will be resolved:

return Promise.all(promises);

How to create a new figure in MATLAB?

The other thing to be careful about, is to use the clf (clear figure) command when you are starting a fresh plot. Otherwise you may be plotting on a pre-existing figure (not possible with the figure command by itself, but if you do figure(2) there may already be a figure #2), with more than one axis, or an axis that is placed kinda funny. Use clf to ensure that you're starting from scratch:

figure(N);
clf;
plot(something);
...

Generating a SHA-256 hash from the Linux command line

If you have installed openssl, you can use:

echo -n "foobar" | openssl dgst -sha256

For other algorithms you can replace -sha256 with -md4, -md5, -ripemd160, -sha, -sha1, -sha224, -sha384, -sha512 or -whirlpool.

How to get nth jQuery element

Why not browse the (short) selectors page first?

Here it is: the :eq() operator. It is used just like get(), but it returns the jQuery object.

Or you can use .eq() function too.

How to get the text node of an element?

ES6 version that return the first #text node content

const extract = (node) => {
  const text = [...node.childNodes].find(child => child.nodeType === Node.TEXT_NODE);
  return text && text.textContent.trim();
}

How Do I Insert a Byte[] Into an SQL Server VARBINARY Column

Try this:

"0x" + BitConverter.ToString(arraytoinsert).Replace("-", "")

Although you should really be using a parameterised query rather than string concatenation of course...

Why is there an unexplainable gap between these inline-block div elements?

You need to add

#container
{
    display:inline-block;
    position:relative;
    background:rgb(255,100,0);
    margin:0px;
    width:40%;
    height:100px;
    margin-right:-4px;
}

because whenever you write display:inline-block it takes an additional margin-right:4px. So, you need to remove it.

Oracle "SQL Error: Missing IN or OUT parameter at index:: 1"

I got the same error and found the cause to be a wrong or missing foreign key. (Using JDBC)

How to implement one-to-one, one-to-many and many-to-many relationships while designing tables?

One to one (1-1) relationship: This is relationship between primary & foreign key (primary key relating to foreign key only one record). this is one to one relationship.

One to Many (1-M) relationship: This is also relationship between primary & foreign keys relationships but here primary key relating to multiple records (i.e. Table A have book info and Table B have multiple publishers of one book).

Many to Many (M-M): Many to many includes two dimensions, explained fully as below with sample.

-- This table will hold our phone calls.
CREATE TABLE dbo.PhoneCalls
(
   ID INT IDENTITY(1, 1) NOT NULL,
   CallTime DATETIME NOT NULL DEFAULT GETDATE(),
   CallerPhoneNumber CHAR(10) NOT NULL
)
-- This table will hold our "tickets" (or cases).
CREATE TABLE dbo.Tickets
(
   ID INT IDENTITY(1, 1) NOT NULL,
   CreatedTime DATETIME NOT NULL DEFAULT GETDATE(),
   Subject VARCHAR(250) NOT NULL,
   Notes VARCHAR(8000) NOT NULL,
   Completed BIT NOT NULL DEFAULT 0
)
-- This table will link a phone call with a ticket.
CREATE TABLE dbo.PhoneCalls_Tickets
(
   PhoneCallID INT NOT NULL,
   TicketID INT NOT NULL
)

2 column div layout: right column with fixed width, left fluid

Hey, What you can do is apply a fixed width to both the containers and then use another div class where clear:both, like

div#left {

width: 600px;
float: left;
}

div#right {

width: 240px;
float: right;

}

div.clear {

clear:both;

}

place a the clear div under left and right container.

git clone error: RPC failed; curl 56 OpenSSL SSL_read: SSL_ERROR_SYSCALL, errno 10054

Uninstalling(version: 2.19.2) and installing(version: 2.21.0) git client fixed the issue for me.

How to auto import the necessary classes in Android Studio with shortcut?

On my Mac Auto import option was not showing it was initially hidden

Android studio ->Preferences->editor->General->Auto Import

and then typed in searched field auto then auto import option appeared. And now auto import option is now always shown as default in Editor->General. hopefully this option will also help others. See attached screenshot screenshot

error running apache after xampp install

I think killing the process which is uses that port is more easy to handle than changing the ports in config files. Here is how to do it in Windows. You can follow same procedure to Linux but different commands. Run command prompt as Administrator. Then type below command to find out all of processes using the port.

netstat -ano

There will be plenty of processes using various ports. So to get only port we need use findstr like below (here I use port 80)

netstat -ano | findstr 80

this will gave you result like this

TCP    0.0.0.0:80             0.0.0.0:0              LISTENING       7964

Last number is the process ID of the process. so what we have to do is kill the process using PID we can use taskkill command for that.

taskkill /PID 7964 /F

Run your server again. This time it will be able to run. This can uses for Mysql server too.

How to set downloading file name in ASP.NET Web API

Note: The last line is mandatory.

If we didn't specify Access-Control-Expose-Headers, we will not get File Name in UI.

FileInfo file = new FileInfo(FILEPATH);

HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);
response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
{
    FileName = file.Name
};
response.Content.Headers.Add("Access-Control-Expose-Headers", "Content-Disposition");

Read file from aws s3 bucket using node fs

You have a couple options. You can include a callback as a second argument, which will be invoked with any error message and the object. This example is straight from the AWS documentation:

s3.getObject(params, function(err, data) {
  if (err) console.log(err, err.stack); // an error occurred
  else     console.log(data);           // successful response
});

Alternatively, you can convert the output to a stream. There's also an example in the AWS documentation:

var s3 = new AWS.S3({apiVersion: '2006-03-01'});
var params = {Bucket: 'myBucket', Key: 'myImageFile.jpg'};
var file = require('fs').createWriteStream('/path/to/file.jpg');
s3.getObject(params).createReadStream().pipe(file);

How to filter for multiple criteria in Excel?

You can pass an array as the first AutoFilter argument and use the xlFilterValues operator.

This will display PDF, DOC and DOCX filetypes.

Criteria1:=Array(".pdf", ".doc", ".docx"), Operator:=xlFilterValues

set serveroutput on in oracle procedure

Actually, you need to call SET SERVEROUTPUT ON; before the BEGIN call.

Everyone suggested this but offers no advice where to actually place the line:

SET SERVEROUTPUT ON;

BEGIN
    FOR rec in (SELECT * FROM EMPLOYEES) LOOP
        DBMS_OUTPUT.PUT_LINE(rec.EmployeeName);
    ENDLOOP;
END;

Otherwise, you won't see any output.

Doing a join across two databases with different collations on SQL Server and getting an error

You can use the collate clause in a query (I can't find my example right now, so my syntax is probably wrong - I hope it points you in the right direction)

select sone_field collate SQL_Latin1_General_CP850_CI_AI
  from table_1
    inner join table_2
      on (table_1.field collate SQL_Latin1_General_CP850_CI_AI = table_2.field)
  where whatever

change image opacity using javascript

I'm not sure if you can do this in every browser but you can set the css property of the specified img.
Try to work with jQuery which allows you to make css changes much faster and efficiently.
in jQuery you will have the options of using .animate(),.fadeTo(),.fadeIn(),.hide("slow"),.show("slow") for example.
I mean this CSS snippet should do the work for you:

img
{
opacity:0.4;
filter:alpha(opacity=40); /* For IE8 and earlier */
}

Also check out this website where everything further is explained:
http://www.w3schools.com/css/css_image_transparency.asp

Pointer arithmetic for void pointer in C

Pointer arithmetic is not allowed on void* pointers.

Example of AES using Crypto++

Official document of Crypto++ AES is a good start. And from my archive, a basic implementation of AES is as follows:

Please refer here with more explanation, I recommend you first understand the algorithm and then try to understand each line step by step.

#include <iostream>
#include <iomanip>

#include "modes.h"
#include "aes.h"
#include "filters.h"

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

    //Key and IV setup
    //AES encryption uses a secret key of a variable length (128-bit, 196-bit or 256-   
    //bit). This key is secretly exchanged between two parties before communication   
    //begins. DEFAULT_KEYLENGTH= 16 bytes
    CryptoPP::byte key[ CryptoPP::AES::DEFAULT_KEYLENGTH ], iv[ CryptoPP::AES::BLOCKSIZE ];
    memset( key, 0x00, CryptoPP::AES::DEFAULT_KEYLENGTH );
    memset( iv, 0x00, CryptoPP::AES::BLOCKSIZE );

    //
    // String and Sink setup
    //
    std::string plaintext = "Now is the time for all good men to come to the aide...";
    std::string ciphertext;
    std::string decryptedtext;

    //
    // Dump Plain Text
    //
    std::cout << "Plain Text (" << plaintext.size() << " bytes)" << std::endl;
    std::cout << plaintext;
    std::cout << std::endl << std::endl;

    //
    // Create Cipher Text
    //
    CryptoPP::AES::Encryption aesEncryption(key, CryptoPP::AES::DEFAULT_KEYLENGTH);
    CryptoPP::CBC_Mode_ExternalCipher::Encryption cbcEncryption( aesEncryption, iv );

    CryptoPP::StreamTransformationFilter stfEncryptor(cbcEncryption, new CryptoPP::StringSink( ciphertext ) );
    stfEncryptor.Put( reinterpret_cast<const unsigned char*>( plaintext.c_str() ), plaintext.length() );
    stfEncryptor.MessageEnd();

    //
    // Dump Cipher Text
    //
    std::cout << "Cipher Text (" << ciphertext.size() << " bytes)" << std::endl;

    for( int i = 0; i < ciphertext.size(); i++ ) {

        std::cout << "0x" << std::hex << (0xFF & static_cast<CryptoPP::byte>(ciphertext[i])) << " ";
    }

    std::cout << std::endl << std::endl;

    //
    // Decrypt
    //
    CryptoPP::AES::Decryption aesDecryption(key, CryptoPP::AES::DEFAULT_KEYLENGTH);
    CryptoPP::CBC_Mode_ExternalCipher::Decryption cbcDecryption( aesDecryption, iv );

    CryptoPP::StreamTransformationFilter stfDecryptor(cbcDecryption, new CryptoPP::StringSink( decryptedtext ) );
    stfDecryptor.Put( reinterpret_cast<const unsigned char*>( ciphertext.c_str() ), ciphertext.size() );
    stfDecryptor.MessageEnd();

    //
    // Dump Decrypted Text
    //
    std::cout << "Decrypted Text: " << std::endl;
    std::cout << decryptedtext;
    std::cout << std::endl << std::endl;

    return 0;
}

For installation details :

sudo apt-get install libcrypto++-dev libcrypto++-doc libcrypto++-utils

android - how to convert int to string and place it in a EditText?

Use +, the string concatenation operator:

ed = (EditText) findViewById (R.id.box);
int x = 10;
ed.setText(""+x);

or use String.valueOf(int):

ed.setText(String.valueOf(x));

or use Integer.toString(int):

ed.setText(Integer.toString(x));

What do 1.#INF00, -1.#IND00 and -1.#IND mean?

For those of you in a .NET environment the following can be a handy way to filter non-numbers out (this example is in VB.NET, but it's probably similar in C#):

If Double.IsNaN(MyVariableName) Then
    MyVariableName = 0 ' Or whatever you want to do here to "correct" the situation
End If

If you try to use a variable that has a NaN value you will get the following error:

Value was either too large or too small for a Decimal.

How might I find the largest number contained in a JavaScript array?

You could sort the array in descending order and get the first item:

[267, 306, 108].sort(function(a,b){return b-a;})[0]

Parsing JSON using C

Json isn't a huge language to start with, so libraries for it are likely to be small(er than Xml libraries, at least).

There are a whole ton of C libraries linked at Json.org. Maybe one of them will work well for you.

What's the purpose of SQL keyword "AS"?

If you design query using the Query editor in SQL Server 2012 for example you would get this:

  SELECT        e.EmployeeID, s.CompanyName, o.ShipName
FROM            Employees AS e INNER JOIN
                         Orders AS o ON e.EmployeeID = o.EmployeeID INNER JOIN
                         Shippers AS s ON o.ShipVia = s.ShipperID
WHERE        (s.CompanyName = 'Federal Shipping')

However removing the AS does not make any difference as in the following:

 SELECT        e.EmployeeID, s.CompanyName, o.ShipName
FROM            Employees e INNER JOIN
                         Orders o ON e.EmployeeID = o.EmployeeID INNER JOIN
                         Shippers s ON o.ShipVia = s.ShipperID
WHERE        (s.CompanyName = 'Federal Shipping')

In this case use of AS is superfluous but in many other places it is needed.

how to bypass Access-Control-Allow-Origin?

I have fixed this problem when calling a MVC3 Controller. I added:

Response.AddHeader("Access-Control-Allow-Origin", "*"); 

before my

return Json(model, JsonRequestBehavior.AllowGet);

And also my $.ajax was complaining that it does not accept Content-type header in my ajax call, so I commented it out as I know its JSON being passed to the Action.

Hope that helps.

Cannot insert explicit value for identity column in table 'table' when IDENTITY_INSERT is set to OFF

If you're having this issue while using an sql-server with the sequelize-typescript npm make sure to add @AutoIncrement to ID column:

  @PrimaryKey
  @AutoIncrement
  @Column
  id!: number;

typedef struct vs struct definitions

Another difference not pointed out is that giving the struct a name (i.e. struct myStruct) also enables you to provide forward declarations of the struct. So in some other file, you could write:

struct myStruct;
void doit(struct myStruct *ptr);

without having to have access to the definition. What I recommend is you combine your two examples:

typedef struct myStruct{
    int one;
    int two;
} myStruct;

This gives you the convenience of the more concise typedef name but still allows you to use the full struct name if you need.

Edit existing excel workbooks and sheets with xlrd and xlwt

As I wrote in the edits of the op, to edit existing excel documents you must use the xlutils module (Thanks Oliver)

Here is the proper way to do it:

#xlrd, xlutils and xlwt modules need to be installed.  
#Can be done via pip install <module>
from xlrd import open_workbook
from xlutils.copy import copy

rb = open_workbook("names.xls")
wb = copy(rb)

s = wb.get_sheet(0)
s.write(0,0,'A1')
wb.save('names.xls')

This replaces the contents of the cell located at a1 in the first sheet of "names.xls" with the text "a1", and then saves the document.

How to create composite primary key in SQL Server 2008

To create a composite unique key on table

ALTER TABLE [TableName] ADD UNIQUE ([Column1], [Column2], [column3]);

How do I call a Django function on button click?

The following answer could be helpful for the first part of your question:

Django: How can I call a view function from template?

How do I update a GitHub forked repository?

Delete your remote dev from github page

then apply these commands:

1) git branch -D dev
2) git fetch upstream
3) git checkout master
4) git fetch upstream && git fetch upstream --prune && git rebase upstream/master && git push -f origin master
5) git checkout -b dev
6) git push origin dev
7) git fetch upstream && git fetch upstream --prune && git rebase upstream/dev && 8) git push -f origin dev

submit form on click event using jquery

If you have a form action and an input type="submit" inside form tags, it's going to submit the old fashioned way and basically refresh the page. When doing AJAX type transactions this isn't the desired effect you are after.

Remove the action. Or remove the form altogether, though in cases it does come in handy to serialize to cut your workload. If the form tags remain, move the button outside the form tags, or alternatively make it a link with an onclick or click handler as opposed to an input button. Jquery UI Buttons works great in this case because you can mimic an input button with an a tag element.

How to get query string parameter from MVC Razor markup?

It was suggested to post this as an answer, because some other answers are giving errors like 'The name Context does not exist in the current context'.

Just using the following works:

Request.Query["queryparm1"]

Sample usage:

<a href="@Url.Action("Query",new {parm1=Request.Query["queryparm1"]})">GO</a>

What is the correct way to check for string equality in JavaScript?

String Objects can be checked using JSON.stringify() trick.

_x000D_
_x000D_
var me = new String("me");
var you = new String("me");
var isEquel = JSON.stringify(me) === JSON.stringify(you);
console.log(isEquel);
_x000D_
_x000D_
_x000D_

How to insert tab character when expandtab option is on in Vim

From the documentation on expandtab:

To insert a real tab when expandtab is on, use CTRL-V<Tab>. See also :retab and ins-expandtab.
This option is reset when the paste option is set and restored when the paste option is reset.

So if you have a mapping for toggling the paste option, e.g.

set pastetoggle=<F2>

you could also do <F2>Tab<F2>.

ImportError: no module named win32api

After installing pywin32

Steps to correctly install your module (pywin32)

  1. First search where is your python pip is present

    1a. For Example in my case location of pip - C:\Users\username\AppData\Local\Programs\Python\Python36-32\Scripts

  2. Then open your command prompt and change directory to your pip folder location.

    cd C:\Users\username\AppData\Local\Programs\Python\Python36-32\Scripts
    
    C:\Users\username\AppData\Local\Programs\Python\Python36-32\Scripts>pip install 
    pypiwin32
    

Restart your IDE

All done now you can use the module .

Simple parse JSON from URL on Android and display in listview

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;

public class GetJsonFromUrl {
    String url = null;

    public GetJsonFromUrl(String url) {
        this.url = url;
    }

    public String GetJsonData() {
        try {
            URL Url = new URL(url);
            HttpURLConnection connection = (HttpURLConnection) Url.openConnection();
            InputStream is = connection.getInputStream();
            BufferedReader br = new BufferedReader(new InputStreamReader(is));
            StringBuilder sb = new StringBuilder();
            String line;
            while ((line = br.readLine()) != null) {
                sb.append(line);
            }
            line = sb.toString();
            connection.disconnect();
            is.close();
            sb.delete(0, sb.length());
            return line;
        } catch (Exception e) {
            return null;
        }
    }
} 

and this class use for post data

import android.util.Log;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;

import javax.net.ssl.HttpsURLConnection;

/**
 * Created by user on 11/2/16.
 */
public class sendDataToServer {
   public String postdata(String requestURL,HashMap<String,String> postDataParams){
        try {
            String response = "";
            URL url = new URL(requestURL);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setReadTimeout(15000);
            conn.setConnectTimeout(15000);
            conn.setRequestMethod("POST");
            conn.setDoInput(true);
            conn.setDoOutput(true);
            OutputStream os = conn.getOutputStream();
            BufferedWriter writer = new BufferedWriter(
                    new OutputStreamWriter(os, "UTF-8"));
            writer.write(getPostDataString(postDataParams));

            writer.flush();
            writer.close();
            os.close();
            String line;
            BufferedReader br=new BufferedReader(new InputStreamReader(conn.getInputStream()));
            while ((line=br.readLine()) != null) {
                response+=line;
            }
            Log.d("test", response);
            return response;
        }catch (Exception e){
            return e.toString();
        }
    }

    public String postjson(String url,String json){
        try {

            URL obj = new URL(url);
            HttpURLConnection con= (HttpURLConnection) obj.openConnection();

            //add reuqest header
            con.setRequestMethod("POST");
            con.setRequestProperty("Accept", "application/json");
            String urlParameters = ""+json;

            // Send post request
            con.setDoOutput(true);
            con.setDoInput(true);
            con.setRequestProperty("Content-Type", "application/json");
            OutputStreamWriter wr = new OutputStreamWriter(con.getOutputStream());
            wr.write(urlParameters);
            wr.flush();
            wr.close();

            int responseCode = con.getResponseCode();
            System.out.println("\nSending 'POST' request to URL : " + url);
            System.out.println("Post parameters : " + urlParameters);
            System.out.println("Response Code : " + responseCode);

            BufferedReader in = new BufferedReader(
                    new InputStreamReader(con.getInputStream()));
            String inputLine;
            StringBuffer response = new StringBuffer();

            while ((inputLine = in.readLine()) != null) {
                response.append(inputLine);
            }
            in.close();

            //print result
            System.out.println(response.toString());
            return response.toString();
        }catch(Exception e){

            return e.toString();
        }
    }

    private String getPostDataString(HashMap<String, String> params) throws UnsupportedEncodingException {
        StringBuilder result = new StringBuilder();
        boolean first = true;
        for(Map.Entry<String, String> entry : params.entrySet()){
            if (first)
                first = false;
            else
                result.append("&");

            result.append(URLEncoder.encode(entry.getKey(), "UTF-8"));
            result.append("=");
            result.append(URLEncoder.encode(entry.getValue(), "UTF-8"));
        }
        return result.toString();
    }

   /* public String postdata(String url) {
    }*/
}

Why not use tables for layout in HTML?

I still don't quite understand how divs / CSS make it easier to change a page design when you consider the amount of testing to ensure the changes work on all browsers, especially with all the hacks and so on. Its a hugely frustrating and tedious process which wastes large amounts of time and money. Thankfully the 508 legislation only applies to the USA (land of the free - yeah right) and so being as I am based in the UK, I can develop web sites in whatever style I choose. Contrary to popular (US) belief, legislation made in Washington doesn't apply to the rest of the world - thank goodness for that. It must have been a good day in the world of web design the day the legislation came into force. I think I'm becoming increasingly cynical as I get older with 25 years in the IT industry but I feel sure this kind of legislation is just to protect jobs. In reality anyone can knock together a reasonable web page with a couple of tables. It takes a lot more effort and knowledge to do this with DIVs / CSS. In my experience it can take hours and hours Googling to find solutions to quite simple problems and reading incomprehensible articles in forums full of idealistic zealots all argueing about the 'right' way to do things. You can't just dip your toe in the water and get things to work properly in every case. It also seems to me that the lack of a definitive guide to using DIVS / CSS "out of the box", that applies to all situations, working on browsers, and written using 'normal' language with no geek speak, also smells of a bit of protectionism.
I'm an application developer and I would say it takes almost twice as long to figure out layout problems and test against all browsers than it does to create the basic application, design and implement business objects, and create the database back end. My time = money, both for me and my customers alike so I am sorry if I don't reject all the pro DIV / CSS arguments in favour of cutting costs and providing value for money for my customers. Maybe its just the way that developers minds work, but it seems to me far easier to change a complex table structure than it is to modify DIVs / CSS. Thankfully it now appears that a solution to these issues is now available - its called WPF.

Is it possible to run a .NET 4.5 app on XP?

I hesitate to post this answer, it is actually technically possible but it doesn't work that well in practice. The version numbers of the CLR and the core framework assemblies were not changed in 4.5. You still target v4.0.30319 of the CLR and the framework assembly version numbers are still 4.0.0.0. The only thing that's distinctive about the assembly manifest when you look at it with a disassembler like ildasm.exe is the presence of a [TargetFramework] attribute that says that 4.5 is needed, that would have to be altered. Not actually that easy, it is emitted by the compiler.

The biggest difference is not that visible, Microsoft made a long-overdue change in the executable header of the assemblies. Which specifies what version of Windows the executable is compatible with. XP belongs to a previous generation of Windows, started with Windows 2000. Their major version number is 5. Vista was the start of the current generation, major version number 6.

.NET compilers have always specified the minimum version number to be 4.00, the version of Windows NT and Windows 9x. You can see this by running dumpbin.exe /headers on the assembly. Sample output looks like this:

OPTIONAL HEADER VALUES
             10B magic # (PE32)
            ...
            4.00 operating system version
            0.00 image version
            4.00 subsystem version              // <=== here!!
               0 Win32 version
            ...

What's new in .NET 4.5 is that the compilers change that subsystem version to 6.00. A change that was over-due in large part because Windows pays attention to that number, beyond just checking if it is small enough. It also turns on appcompat features since it assumes that the program was written to work on old versions of Windows. These features cause trouble, particularly the way Windows lies about the size of a window in Aero is troublesome. It stops lying about the fat borders of an Aero window when it can see that the program was designed to run on a Windows version that has Aero.

You can alter that version number and set it back to 4.00 by running Editbin.exe on your assemblies with the /subsystem option. This answer shows a sample postbuild event.

That's however about where the good news ends, a significant problem is that .NET 4.5 isn't very compatible with .NET 4.0. By far the biggest hang-up is that classes were moved from one assembly to another. Most notably, that happened for the [Extension] attribute. Previously in System.Core.dll, it got moved to Mscorlib.dll in .NET 4.5. That's a kaboom on XP if you declare your own extension methods, your program says to look in Mscorlib for the attribute, enabled by a [TypeForwardedTo] attribute in the .NET 4.5 version of the System.Core reference assembly. But it isn't there when you run your program on .NET 4.0

And of course there's nothing that helps you stop using classes and methods that are only available on .NET 4.5. When you do, your program will fail with a TypeLoadException or MissingMethodException when run on 4.0

Just target 4.0 and all of these problems disappear. Or break that logjam and stop supporting XP, a business decision that programmers cannot often make but can certainly encourage by pointing out the hassles that it is causing. There is of course a non-zero cost to having to support ancient operating systems, just the testing effort is substantial. A cost that isn't often recognized by management, Windows compatibility is legendary, unless it is pointed out to them. Forward that cost to the client and they tend to make the right decision a lot quicker :) But we can't help you with that.

Quick way to retrieve user information Active Directory

I'm not sure how much of your "slowness" will be due to the loop you're doing to find entries with particular attribute values, but you can remove this loop by being more specific with your filter. Try this page for some guidance ... Search Filter Syntax

Error in spring application context schema

If you don't have control those files, as those files can be part of other projects and you are not authorized to make any changes, then you can bypass those errors in eclipse by going, Preferences --> XML --> XML Files --> Validation --> Referenced file contains errors --> choose Ignore option.

And let project get's validated, the error message will disappear.

How much memory can a 32 bit process access on a 64 bit operating system?

A 32-bit process is still limited to the same constraints in a 64-bit OS. The issue is that memory pointers are only 32-bits wide, so the program can't assign/resolve any memory address larger than 32 bits.

Simple C example of doing an HTTP POST and consuming the response

After weeks of research. I came up with the following code. I believe this is the bare minimum needed to make a secure connection with SSL to a web server.

#include <stdio.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/bio.h>

#define APIKEY "YOUR_API_KEY"
#define HOST "YOUR_WEB_SERVER_URI"
#define PORT "443"

int main() {

    //
    //  Initialize the variables
    //
    BIO* bio;
    SSL* ssl;
    SSL_CTX* ctx;

    //
    //   Registers the SSL/TLS ciphers and digests.
    //
    //   Basically start the security layer.
    //
    SSL_library_init();

    //
    //  Creates a new SSL_CTX object as a framework to establish TLS/SSL
    //  or DTLS enabled connections
    //
    ctx = SSL_CTX_new(SSLv23_client_method());

    //
    //  -> Error check
    //
    if (ctx == NULL)
    {
        printf("Ctx is null\n");
    }

    //
    //   Creates a new BIO chain consisting of an SSL BIO
    //
    bio = BIO_new_ssl_connect(ctx);

    //
    //  Use the variable from the beginning of the file to create a 
    //  string that contains the URL to the site that you want to connect
    //  to while also specifying the port.
    //
    BIO_set_conn_hostname(bio, HOST ":" PORT);

    //
    //   Attempts to connect the supplied BIO
    //
    if(BIO_do_connect(bio) <= 0)
    {
        printf("Failed connection\n");
        return 1;
    }
    else
    {
        printf("Connected\n");
    }

    //
    //  The bare minimum to make a HTTP request.
    //
    char* write_buf = "POST / HTTP/1.1\r\n"
                      "Host: " HOST "\r\n"
                      "Authorization: Basic " APIKEY "\r\n"
                      "Connection: close\r\n"
                      "\r\n";

    //
    //   Attempts to write len bytes from buf to BIO
    //
    if(BIO_write(bio, write_buf, strlen(write_buf)) <= 0)
    {
        //
        //  Handle failed writes here
        //
        if(!BIO_should_retry(bio))
        {
            // Not worth implementing, but worth knowing.
        }

        //
        //  -> Let us know about the failed writes
        //
        printf("Failed write\n");
    }

    //
    //  Variables used to read the response from the server
    //
    int size;
    char buf[1024];

    //
    //  Read the response message
    //
    for(;;)
    {
        //
        //  Get chunks of the response 1023 at the time.
        //
        size = BIO_read(bio, buf, 1023);

        //
        //  If no more data, then exit the loop
        //
        if(size <= 0)
        {
            break;
        }

        //
        //  Terminate the string with a 0, to let know C when the string 
        //  ends.
        //
        buf[size] = 0;

        //
        //  ->  Print out the response
        //
        printf("%s", buf);
    }

    //
    //  Clean after ourselves
    //
    BIO_free_all(bio);
    SSL_CTX_free(ctx);

    return 0;
}

The code above will explain in details how to establish a TLS connection with a remote server.

Important note: this code doesn't check if the public key was signed by a valid authority. Meaning I don't use root certificates for validation. Don't forget to implement this check otherwise you won't know if you are connecting the right website

When it comes to the request itself. It is nothing more then writing the HTTP request by hand.

You can also find under this link an explanation how to instal openSSL in your system, and how to compile the code so it uses the secure library.

How can I get a side-by-side diff when I do "git diff"?

Open Intellij IDEA, select a single or multiple commits in the "Version Control" tool window, browse changed files, and double click them to inspect changes side by side for each file.

With the bundled command-line launcher you can bring IDEA up anywhere with a simple idea some/path

version control view diff view

Could not obtain information about Windows NT group user

In our case, the Windows service account that SQL Server and SQL Agent were running under were locked out in Active Directory.

Unable to create migrations after upgrading to ASP.NET Core 2.0

If you want to avoid those IDesignTimeDbContextFactory thing: Just make sure that you don't use any Seed method in your startup. I was using a static seed method in my startup and it was causing this error for me.

How do I determine height and scrolling position of window in jQuery?

From jQuery Docs:

const height = $(window).height();
const scrollTop = $(window).scrollTop();

http://api.jquery.com/scrollTop/
http://api.jquery.com/height/

How to Apply global font to whole HTML document

Set it in the body selector of your css. E.g.

body {
    font: 16px Arial, sans-serif;
}

How can I check if a Perl array contains a particular value?

This blog post discusses the best answers to this question.

As a short summary, if you can install CPAN modules then the most readable solutions are:

any(@ingredients) eq 'flour';

or

@ingredients->contains('flour');

However, a more common idiom is:

any { $_ eq 'flour' } @ingredients

But please don't use the first() function! It doesn't express the intent of your code at all. Don't use the ~~ "Smart match" operator: it is broken. And don't use grep() nor the solution with a hash: they iterate through the whole list.

any() will stop as soon as it finds your value.

Check out the blog post for more details.

Print the address or pointer for value in C

char c = 'A';
printf("ptr: %p,\tvalue: %c,\tand also address: %zu", &c, c, &c);

Result:

ptr: 0x7ffc48e5105f,    value: A,    and also address: 140721531457631

Add attribute 'checked' on click jquery

use this code

var sid = $(this);
sid.attr('checked','checked');

What are the main differences between JWT and OAuth authentication?

find the main differences between JWT & OAuth

  1. OAuth 2.0 defines a protocol & JWT defines a token format.

  2. OAuth can use either JWT as a token format or access token which is a bearer token.

  3. OpenID connect mostly use JWT as a token format.

how to output every line in a file python

You could try this. It doesn't read all of f into memory at once (using the file object's iterator) and it closes the file when the code leaves the with block.

if data.find('!masters') != -1:
    with open('masters.txt', 'r') as f:
        for line in f:
            print line
            sck.send('PRIVMSG ' + chan + " " + line + '\r\n')

If you're using an older version of python (pre 2.6) you'll have to have

from __future__ import with_statement

How do you setLayoutParams() for an ImageView?

Old thread but I had the same problem now. If anyone encounters this he'll probably find this answer:

LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(30, 30);
yourImageView.setLayoutParams(layoutParams);

This will work only if you add the ImageView as a subView to a LinearLayout. If you add it to a RelativeLayout you will need to call:

RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(30, 30);
yourImageView.setLayoutParams(layoutParams);

Does Hive have a String split function?

Another interesting usecase for split in Hive is when, for example, a column ipname in the table has a value "abc11.def.ghft.com" and you want to pull "abc11" out:

SELECT split(ipname,'[\.]')[0] FROM tablename;

Interface naming in Java

There may be several reasons Java does not generally use the IUser convention.

  1. Part of the Object-Oriented approach is that you should not have to know whether the client is using an interface or an implementation class. So, even List is an interface and String is an actual class, a method might be passed both of them - it doesn't make sense to visually distinguish the interfaces.

  2. In general, we will actually prefer the use of interfaces in client code (prefer List to ArrayList, for instance). So it doesn't make sense to make the interfaces stand out as exceptions.

  3. The Java naming convention prefers longer names with actual meanings to Hungarian-style prefixes. So that code will be as readable as possible: a List represents a list, and a User represents a user - not an IUser.

Java - Find shortest path between 2 points in a distance weighted map

Maintain a list of nodes you can travel to, sorted by the distance from your start node. In the beginning only your start node will be in the list.

While you haven't reached your destination: Visit the node closest to the start node, this will be the first node in your sorted list. When you visit a node, add all its neighboring nodes to your list except the ones you have already visited. Repeat!

java.lang.IllegalStateException: Error processing condition on org.springframework.boot.autoconfigure.jdbc.JndiDataSourceAutoConfiguration

This is caused by non-matching Spring Boot dependencies. Check your classpath to find the offending resources. You have explicitly included version 1.1.8.RELEASE, but you have also included 3 other projects. Those likely contain different Spring Boot versions, leading to this error.

In Eclipse, what can cause Package Explorer "red-x" error-icon when all Java sources compile without errors?

I had the same issue and below steps resolved the issue:

  1. Delete the JRE from PROJECT> properties>java build path> libraries.

  2. Restart the eclipse

  3. Add the JRE again

  4. Rebuild the project using Project>Clean and chose option to build automatically.

Please try.

How to get the date and time values in a C program?

I'm getting the following error when compiling Adam Rosenfield's code on Windows. It turns out few things are missing from the code.

Error (Before)

C:\C\Codes>gcc time.c -o time
time.c:3:12: error: initializer element is not constant
 time_t t = time(NULL);
            ^
time.c:4:16: error: initializer element is not constant
 struct tm tm = *localtime(&t);
                ^
time.c:6:8: error: expected declaration specifiers or '...' before string constant
 printf("now: %d-%d-%d %d:%d:%d\n", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
        ^
time.c:6:36: error: expected declaration specifiers or '...' before 'tm'
 printf("now: %d-%d-%d %d:%d:%d\n", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
                                    ^
time.c:6:55: error: expected declaration specifiers or '...' before 'tm'
 printf("now: %d-%d-%d %d:%d:%d\n", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
                                                       ^
time.c:6:70: error: expected declaration specifiers or '...' before 'tm'
 printf("now: %d-%d-%d %d:%d:%d\n", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
                                                                      ^
time.c:6:82: error: expected declaration specifiers or '...' before 'tm'
 printf("now: %d-%d-%d %d:%d:%d\n", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
                                                                                  ^
time.c:6:94: error: expected declaration specifiers or '...' before 'tm'
 printf("now: %d-%d-%d %d:%d:%d\n", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
                                                                                              ^
time.c:6:105: error: expected declaration specifiers or '...' before 'tm'
 printf("now: %d-%d-%d %d:%d:%d\n", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
                                                                                                         ^
C:\C\Codes>

Solution

C:\C\Codes>more time.c
#include <stdio.h>
#include <time.h>

int main()
{
        time_t t = time(NULL);
        struct tm tm = *localtime(&t);

        printf("now: %d-%d-%d %d:%d:%d\n", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
}

C:\C\Codes>

Compiling

C:\C\Codes>gcc time.c -o time

C:\C\Codes>    

Final Output

C:\C\Codes>time
now: 2018-3-11 15:46:36

C:\C\Codes>

I hope this will helps others too

Shortcut key for commenting out lines of Python code in Spyder

  • Single line comment

    Ctrl + 1

  • Multi-line comment select the lines to be commented

    Ctrl + 4

  • Unblock Multi-line comment

    Ctrl + 5

sh: 0: getcwd() failed: No such file or directory on cited drive

if some directory/folder does not exist but somehow you navigated to that directory in that case you can see this Error,

for example:

  • currently, you are in "mno" directory (path = abc/def/ghi/jkl/mno
  • run "sudo su" and delete mno
  • goto the "ghi" directory and delete "jkl" directory
  • now you are in "ghi" directory (path abc/def/ghi)
  • run "exit"
  • after running the "exit", you will get that Error
  • now you will be in "mno"(path = abc/def/ghi/jkl/mno) folder. that does not exist.

so, Generally this Error will show when Directory doesn't exist.

to fix this, simply run "cd;" or you can move to any other directory which exists.

WARNING: Can't verify CSRF token authenticity rails

If you are not using jQuery and using something like fetch API for requests you can use the following to get the csrf-token:

document.querySelector('meta[name="csrf-token"]').getAttribute('content')

fetch('/users', {
  method: 'POST',
  headers: {
    'Accept': 'application/json',
    'Content-Type': 'application/json',
    'X-CSRF-Token': document.querySelector('meta[name="csrf-token"]').getAttribute('content')},
    credentials: 'same-origin',
    body: JSON.stringify( { id: 1, name: 'some user' } )
    })
    .then(function(data) {
      console.log('request succeeded with JSON response', data)
    }).catch(function(error) {
      console.log('request failed', error)
    })

Why in C++ do we use DWORD rather than unsigned int?

DWORD is not a C++ type, it's defined in <windows.h>.

The reason is that DWORD has a specific range and format Windows functions rely on, so if you require that specific range use that type. (Or as they say "When in Rome, do as the Romans do.") For you, that happens to correspond to unsigned int, but that might not always be the case. To be safe, use DWORD when a DWORD is expected, regardless of what it may actually be.

For example, if they ever changed the range or format of unsigned int they could use a different type to underly DWORD to keep the same requirements, and all code using DWORD would be none-the-wiser. (Likewise, they could decide DWORD needs to be unsigned long long, change it, and all code using DWORD would be none-the-wiser.)


Also note unsigned int does not necessary have the range 0 to 4,294,967,295. See here.

MySQL command line client for Windows

mysql.exe can do just that....

To connect,

mysql -u root -p (press enter)

It should prompt you to enter root password (u = username, p = password)

Then you can use SQL database commands to do pretty much anything....

How can I verify if one list is a subset of another?

>>> a = [1, 3, 5]
>>> b = [1, 3, 5, 8]
>>> c = [3, 5, 9]
>>> set(a) <= set(b)
True
>>> set(c) <= set(b)
False

>>> a = ['yes', 'no', 'hmm']
>>> b = ['yes', 'no', 'hmm', 'well']
>>> c = ['sorry', 'no', 'hmm']
>>> 
>>> set(a) <= set(b)
True
>>> set(c) <= set(b)
False

Laravel 5.2 Missing required parameters for [Route: user.profile] [URI: user/{nickname}/profile]

My Solution in laravel 5.2

{{ Form::open(['route' => ['votes.submit', $video->id],  'method' => 'POST']) }}
    <button type="submit" class="btn btn-primary">
        <span class="glyphicon glyphicon-thumbs-up"></span> Votar
    </button>
{{ Form::close() }}

My Routes File (under middleware)

Route::post('votar/{id}', [
    'as' => 'votes.submit',
    'uses' => 'VotesController@submit'
]);

Route::delete('votar/{id}', [
    'as' => 'votes.destroy',
    'uses' => 'VotesController@destroy'
]);

Hibernate dialect for Oracle Database 11g?

use only org.hibernate.dialect.OracleDialect Remove 10g,9 etc.

Set line height in Html <p> to make the html looks like a office word when <p> has different font sizes

You can set the line-height in pixels instead of percentage. Is that what you mean?

How to use && in EL boolean expressions in Facelets?

In addition to the answer of BalusC, use the following Java RegExp to replace && with and:

Search:  (#\{[^\}]*)(&&)([^\}]*\})
Replace: $1and$3

You have run this regular expression replacement multiple times to find all occurences in case you are using >2 literals in your EL expressions. Mind to replace the leading # by $ if your EL expression syntax differs.

Bootstrap 3 panel header with buttons wrong position

I placed the button group inside the title, and then added a clearfix to the bottom.

<div class="panel-heading">
  <h4 class="panel-title">
    Panel header
    <div class="btn-group pull-right">
      <a href="#" class="btn btn-default btn-sm">## Lock</a>
      <a href="#" class="btn btn-default btn-sm">## Delete</a>
      <a href="#" class="btn btn-default btn-sm">## Move</a>
    </div>
  </h4>
  <div class="clearfix"></div>
</div>

How to pass 2D array (matrix) in a function in C?

I don't know what you mean by "data dont get lost". Here's how you pass a normal 2D array to a function:

void myfunc(int arr[M][N]) { // M is optional, but N is required
  ..
}

int main() {
  int somearr[M][N];
  ...
  myfunc(somearr);
  ...
}

How to generate a random string of a fixed length in Go?

You can just write code for it. This code can be a little simpler if you want to rely on the letters all being single bytes when encoded in UTF-8.

package main

import (
    "fmt"
    "time"
    "math/rand"
)

var letters = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")

func randSeq(n int) string {
    b := make([]rune, n)
    for i := range b {
        b[i] = letters[rand.Intn(len(letters))]
    }
    return string(b)
}

func main() {
    rand.Seed(time.Now().UnixNano())

    fmt.Println(randSeq(10))
}

Bootstrap: wider input field

I made a wider input field by using either span4 or span6 as class.

<input type="text" class="span6 input-large search-query">

This way you don't need the additional custom css, mentioned earlier.

Redirect to an external URL from controller action in Spring MVC

For external url you have to use "http://www.yahoo.com" as the redirect url.

This is explained in the redirect: prefix of Spring reference documentation.

redirect:/myapp/some/resource

will redirect relative to the current Servlet context, while a name such as

redirect:http://myhost.com/some/arbitrary/path

will redirect to an absolute URL

Cross-Origin Request Blocked

@Egidius, when creating an XMLHttpRequest, you should use

var xhr = new XMLHttpRequest({mozSystem: true});

What is mozSystem?

mozSystem Boolean: Setting this flag to true allows making cross-site connections without requiring the server to opt-in using CORS. Requires setting mozAnon: true, i.e. this can't be combined with sending cookies or other user credentials. This only works in privileged (reviewed) apps; it does not work on arbitrary webpages loaded in Firefox.

Changes to your Manifest

On your manifest, do not forget to include this line on your permissions:

"permissions": {
       "systemXHR" : {},
}

How to add scroll bar to the Relative Layout?

The following code should do the trick:

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/ScrollView01"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

<RelativeLayout
android:id="@+id/RelativeLayout01"
android:layout_width="fill_parent"
android:layout_height="638dp" >

<TextView
    android:id="@+id/textView1"
    style="@style/normalcode"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:layout_marginTop="64dp"
    android:text="Email" />

<TextView
    android:id="@+id/textView2"
    style="@style/normalcode"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/textView1"
    android:layout_marginTop="41dp"
    android:text="Password" />

<TextView
    android:id="@+id/textView3"
    style="@style/normalcode"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignRight="@+id/textView2"
    android:layout_below="@+id/textView2"
    android:layout_marginTop="47dp"
    android:text="Confirm Password" />

<EditText
    android:id="@+id/editText1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/textView1"
    android:layout_alignBottom="@+id/textView1"
    android:layout_alignParentRight="true"
    android:layout_toRightOf="@+id/textView4"
    android:inputType="textEmailAddress" >

    <requestFocus />
</EditText>

<EditText
    android:id="@+id/editText2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/textView2"
    android:layout_alignBottom="@+id/textView2"
    android:layout_alignLeft="@+id/editText1"
    android:layout_alignParentRight="true"
    android:inputType="textPassword" />

<EditText
    android:id="@+id/editText3"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/textView3"
    android:layout_alignBottom="@+id/textView3"
    android:layout_alignLeft="@+id/editText2"
    android:layout_alignParentRight="true"
    android:inputType="textPassword" />


<TextView
    android:id="@+id/textView4"
    style="@style/normalcode"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_below="@+id/textView3"
    android:layout_marginTop="42dp"
    android:text="Date of Birth" />

<DatePicker
    android:id="@+id/datePicker1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentRight="true"
    android:layout_below="@+id/textView4" />

<TextView
    android:id="@+id/textView5"
    style="@style/normalcode"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/datePicker1"
    android:layout_marginTop="60dp"
    android:layout_toLeftOf="@+id/datePicker1"
    android:text="Gender" />

<RadioButton
    android:id="@+id/radioButton1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/textView5"
    android:layout_alignBottom="@+id/textView5"
    android:layout_alignLeft="@+id/editText3"
    android:layout_marginLeft="24dp"
    android:text="Male" />

<RadioButton
    android:id="@+id/radioButton2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/radioButton1"
    android:layout_below="@+id/radioButton1"
    android:layout_marginTop="14dp"
    android:text="Female" />

<Button
    android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_marginBottom="23dp"
    android:layout_toLeftOf="@+id/radioButton2"
    android:background="@drawable/rectbutton"
    android:text="Sign Up" />

How to use su command over adb shell?

On my Linux I see an error with

adb shell "su -c '[your command goes here]'"

su: invalid uid/gid '-c'

The solution is on Linux

adb shell su 0 '[your command goes here]'

Android: How to stretch an image to the screen width while maintaining aspect ratio?

I've been struggling with this problem in one form or another for AGES, thank you, Thank You, THANK YOU.... :)

I just wanted to point out that you can get a generalizable solution from what Bob Lee's done by just extending View and overriding onMeasure. That way you can use this with any drawable you want, and it won't break if there's no image:

    public class CardImageView extends View {
        public CardImageView(Context context, AttributeSet attrs, int defStyle) {
            super(context, attrs, defStyle);
        }

        public CardImageView(Context context, AttributeSet attrs) {
            super(context, attrs);
        }

        public CardImageView(Context context) {
            super(context);
        }

        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            Drawable bg = getBackground();
            if (bg != null) {
                int width = MeasureSpec.getSize(widthMeasureSpec);
                int height = width * bg.getIntrinsicHeight() / bg.getIntrinsicWidth();
                setMeasuredDimension(width,height);
            }
            else {
                super.onMeasure(widthMeasureSpec, heightMeasureSpec);
            }
        }
    }

Progress Bar with HTML and CSS

Same as @RoToRa's answer, with a some slight adjustments (correct colors and dimensions):

_x000D_
_x000D_
body {_x000D_
  background-color: #636363;_x000D_
  padding: 1em;_x000D_
}_x000D_
_x000D_
#progressbar {_x000D_
  background-color: #20201F;_x000D_
  border-radius: 20px; /* (heightOfInnerDiv / 2) + padding */_x000D_
  padding: 4px;_x000D_
}_x000D_
_x000D_
#progressbar>div {_x000D_
  background-color: #F7901E;_x000D_
  width: 48%;_x000D_
  /* Adjust with JavaScript */_x000D_
  height: 16px;_x000D_
  border-radius: 10px;_x000D_
}
_x000D_
<div id="progressbar">_x000D_
  <div></div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Here's the fiddle: jsFiddle

And here's what it looks like: jsFiddle-screenshot

Can we open pdf file using UIWebView on iOS?

Swift version:

if let docPath = NSBundle.mainBundle().pathForResource("sample", ofType: "pdf") {
    let docURL = NSURL(fileURLWithPath: docPath)
    webView.loadRequest(NSURLRequest(URL: docURL))
}

How to stop flask application without using ctrl-c

As others have pointed out, you can only use werkzeug.server.shutdown from a request handler. The only way I've found to shut down the server at another time is to send a request to yourself. For example, the /kill handler in this snippet will kill the dev server unless another request comes in during the next second:

import requests
from threading import Timer
from flask import request
import time

LAST_REQUEST_MS = 0
@app.before_request
def update_last_request_ms():
    global LAST_REQUEST_MS
    LAST_REQUEST_MS = time.time() * 1000


@app.route('/seriouslykill', methods=['POST'])
def seriouslykill():
    func = request.environ.get('werkzeug.server.shutdown')
    if func is None:
        raise RuntimeError('Not running with the Werkzeug Server')
    func()
    return "Shutting down..."


@app.route('/kill', methods=['POST'])
def kill():
    last_ms = LAST_REQUEST_MS
    def shutdown():
        if LAST_REQUEST_MS <= last_ms:  # subsequent requests abort shutdown
            requests.post('http://localhost:5000/seriouslykill')
        else:
            pass

    Timer(1.0, shutdown).start()  # wait 1 second
    return "Shutting down..."

opening a window form from another form programmatically

You just need to use Dispatcher to perform graphical operation from a thread other then UI thread. I don't think that this will affect behavior of the main form. This may help you : Accessing UI Control from BackgroundWorker Thread

Parse Error: Adjacent JSX elements must be wrapped in an enclosing tag

React 16 gets your return as an array so it should be wrapped by one element like div.

Wrong Approach

render(){
    return(
    <input type="text" value="" onChange={this.handleChange} />

     <button className="btn btn-primary" onClick=   {()=>this.addTodo(this.state.value)}>Submit</button>

    );
}

Right Approach (All elements in one div or other element you are using)

render(){
    return(
        <div>
            <input type="text" value="" onChange={this.handleChange} />

            <button className="btn btn-primary" onClick={()=>this.addTodo(this.state.value)}>Submit</button>
        </div>
    );
}

Why do we need virtual functions in C++?

Here is complete example that illustrates why virtual method is used.

#include <iostream>

using namespace std;

class Basic
{
    public:
    virtual void Test1()
    {
        cout << "Test1 from Basic." << endl;
    }
    virtual ~Basic(){};
};
class VariantA : public Basic
{
    public:
    void Test1()
    {
        cout << "Test1 from VariantA." << endl;
    }
};
class VariantB : public Basic
{
    public:
    void Test1()
    {
        cout << "Test1 from VariantB." << endl;
    }
};

int main()
{
    Basic *object;
    VariantA *vobjectA = new VariantA();
    VariantB *vobjectB = new VariantB();

    object=(Basic *) vobjectA;
    object->Test1();

    object=(Basic *) vobjectB;
    object->Test1();

    delete vobjectA;
    delete vobjectB;
    return 0;
}

How to remove carriage returns and new lines in Postgresql?

OP asked specifically about regexes since it would appear there's concern for a number of other characters as well as newlines, but for those just wanting strip out newlines, you don't even need to go to a regex. You can simply do:

select replace(field,E'\n','');

I think this is an SQL-standard behavior, so it should extend back to all but perhaps the very earliest versions of Postgres. The above tested fine for me in 9.4 and 9.2

Alter SQL table - allow NULL column value

ALTER TABLE MyTable MODIFY Col3 varchar(20) NULL;

What are Unwind segues for and how do you use them?

Unwind segues are used to "go back" to some view controller from which, through a number of segues, you got to the "current" view controller.

Imagine you have something a MyNavController with A as its root view controller. Now you use a push segue to B. Now the navigation controller has A and B in its viewControllers array, and B is visible. Now you present C modally.

With unwind segues, you could now unwind "back" from C to B (i.e. dismissing the modally presented view controller), basically "undoing" the modal segue. You could even unwind all the way back to the root view controller A, undoing both the modal segue and the push segue.

Unwind segues make it easy to backtrack. For example, before iOS 6, the best practice for dismissing presented view controllers was to set the presenting view controller as the presented view controller’s delegate, then call your custom delegate method, which then dismisses the presentedViewController. Sound cumbersome and complicated? It was. That’s why unwind segues are nice.

Find and Replace text in the entire table using a MySQL query

If you are positive that none of the fields to be updated are serialized, the solutions above will work well.

However, if any of the fields that need updating contain serialized data, an SQL Query or a simple search/replace on a dump file, will break serialization (unless the replaced string has exactly the same number of characters as the searched string).

To be sure, a "serialized" field looks like this:

a:1:{s:13:"administrator";b:1;}  

The number of characters in the relevant data is encoded as part of the data.
Serialization is a way to convert "objects" into a format easily stored in a database, or to easily transport object data between different languages.
Here is an explanation of different methods used to serialize object data, and why you might want to do so, and here is a WordPress-centric post: Serialized Data, What Does That Mean And Why is it so Important? in plain language.

It would be amazing if MySQL had some built in tool to handle serialized data automatically, but it does not, and since there are different serialization formats, it would not even make sense for it to do so.

wp-cli
Some of the answers above seemed specific to WordPress databases, which serializes much of its data. WordPress offers a command line tool, wp search-replace, that does handle serialization.
A basic command would be:

    wp search-replace 'an-old-string' 'a-new-string' --dry-run

However, WordPress emphasizes that the guid should never be changed, so it recommends skipping that column.
It also suggests that often times you'll want to skip the wp_users table.
Here's what that would look like:

wp search-replace 'https://old-domain.com' 'https://shiney-new-domain.com' --skip-columns=guid --skip-tables=wp_users --dry-run

Note: I added the --dry-run flag so a copy-paste won't automatically ruin anyone's database. After you're sure the script does what you want, run it again without that flag.

Plugins
If you are using WordPress, there are also many free and commercial plugins available that offer a gui interface to do the same, packaged with many additional features.

Interconnect/it php script
Interconnect/it offers a php script to handle serialized data: Safe Search and Replace tool. It was created for use on WordPress sites, but it looks like it can be used on any database serialized by PHP.
Many companies, including WordPress itself, recommends this tool. Instructions here, about 3/4 down the page.

Programmatically change UITextField Keyboard type

Programmatically change UITextField Keyboard type swift 3.0

lazy var textFieldTF: UITextField = {

    let textField = UITextField()
    textField.placeholder = "Name"
    textField.frame = CGRect(x:38, y: 100, width: 244, height: 30)
    textField.textAlignment = .center
    textField.borderStyle = UITextBorderStyle.roundedRect
    textField.keyboardType = UIKeyboardType.default //keyboard type
    textField.delegate = self
    return textField 
}() 
override func viewDidLoad() {
    super.viewDidLoad()
    view.addSubview(textFieldTF)
}

Editing the date formatting of x-axis tick labels in matplotlib

From the package matplotlib.dates as shown in this example the date format can be applied to the axis label and ticks for plot.

Below I have given an example for labeling axis ticks for multiplots

import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import pandas as pd

df = pd.read_csv('US_temp.csv')
plt.plot(df['Date'],df_f['MINT'],label='Min Temp.')
plt.plot(df['Date'],df_f['MAXT'],label='Max Temp.')
plt.legend()
####### Use the below functions #######
dtFmt = mdates.DateFormatter('%b') # define the formatting
plt.gca().xaxis.set_major_formatter(dtFmt) # apply the format to the desired axis
plt.show()

As simple as that

Convert char* to string C++

std::string str(buffer, buffer + length);

Or, if the string already exists:

str.assign(buffer, buffer + length);

Edit: I'm still not completely sure I understand the question. But if it's something like what JoshG is suggesting, that you want up to length characters, or until a null terminator, whichever comes first, then you can use this:

std::string str(buffer, std::find(buffer, buffer + length, '\0'));

How to use Console.WriteLine in ASP.NET (C#) during debug?

Make sure you start your application in Debug mode (F5), not without debugging (Ctrl+F5) and then select "Show output from: Debug" in the Output panel in Visual Studio.

javascript node.js next()

It's basically like a callback that express.js use after a certain part of the code is executed and done, you can use it to make sure that part of code is done and what you wanna do next thing, but always be mindful you only can do one res.send in your each REST block...

So you can do something like this as a simple next() example:

app.get("/", (req, res, next) => {
  console.log("req:", req, "res:", res);
  res.send(["data": "whatever"]);
  next();
},(req, res) =>
  console.log("it's all done!");
);

It's also very useful when you'd like to have a middleware in your app...

To load the middleware function, call app.use(), specifying the middleware function. For example, the following code loads the myLogger middleware function before the route to the root path (/).

var express = require('express');
var app = express();

var myLogger = function (req, res, next) {
  console.log('LOGGED');
  next();
}

app.use(myLogger);

app.get('/', function (req, res) {
  res.send('Hello World!');
})

app.listen(3000);

AngularJS : How do I switch views from a controller function?

I've got an example working.

Here's how my doc looks:

<html>
<head>
    <link rel="stylesheet" href="css/main.css">
    <script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.0.3/angular.min.js"></script>
    <script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.0.3/angular-resource.min.js"></script>
    <script src="js/app.js"></script>
    <script src="controllers/ctrls.js"></script>
</head>
<body ng-app="app">
    <div id="contnr">
        <ng-view></ng-view>
    </div>
</body>
</html>

Here's what my partial looks like:

<div id="welcome" ng-controller="Index">
    <b>Welcome! Please Login!</b>
    <form ng-submit="auth()">
        <input class="input login username" type="text" placeholder="username" /><br>
        <input class="input login password" type="password" placeholder="password" /><br>
        <input class="input login submit" type="submit" placeholder="login!" />
    </form>
</div>

Here's what my Ctrl looks like:

app.controller('Index', function($scope, $routeParams, $location){
    $scope.auth = function(){
        $location.url('/map');
    };
});

app is my module:

var app = angular.module('app', ['ngResource']).config(function($routeProvider)...

Hope this is helpful!

Difference between string and StringBuilder in C#

Strings are immutable i.e if you change their value, the old value will be discarded and a new value is created on the heap, whereas in string builder we can modify the existing value without the new value being created.

So performance-wise String Builder is beneficial as we are needlessly not occupying more memory space.

Evaluate a string with a switch in C++

As said before, switch can be used only with integer values. So, you just need to convert your "case" values to integer. You can achieve it by using constexpr from c++11, thus some calls of constexpr functions can be calculated in compile time.

something like that...

switch (str2int(s))
{
  case str2int("Value1"):
    break;
  case str2int("Value2"):
    break;
}

where str2int is like (implementation from here):

constexpr unsigned int str2int(const char* str, int h = 0)
{
    return !str[h] ? 5381 : (str2int(str, h+1) * 33) ^ str[h];
}

Another example, the next function can be calculated in compile time:

constexpr int factorial(int n)
{
    return n <= 1 ? 1 : (n * factorial(n-1));
}  

int f5{factorial(5)};
// Compiler will run factorial(5) 
// and f5 will be initialized by this value. 
// so programm instead of wasting time for running function, 
// just will put the precalculated constant to f5 

What is .Net Framework 4 extended?

It's the part of the .NET Framework that isn't contained within the Client Profile. See MSDN for more info; specifically:

The .NET Framework is made up of the .NET Framework 4 Client Profile and .NET Framework 4 Extended components that exist separately in Programs and Features.

How can I nullify css property?

You need to provide a selector with higher specificity than the one in Main.css. With that selector, set the values of the properties you want to their default, e.g.

body .c1 {
    height: auto;
}

There is no "default" value that will work for all properties, you need to look up what the default is for each one and use that.

A column-vector y was passed when a 1d array was expected

Y = y.values[:,0]

Y - formated_train_y

y - train_y

The type or namespace name does not exist in the namespace 'System.Web.Mvc'

It's likely that setting your DLL to CopyLocal/true or any of the other major fixes for this will fix your issue, but here is another edge-case that caught me for 20 minutes of wasted time.

When you add your namespaces to your Views/Web.config, ensure they are cased correctly:

  <system.web.webPages.razor>
    <host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=5.2.3.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
    <pages pageBaseType="System.Web.Mvc.WebViewPage">
      <namespaces>
        <add namespace="THE.NameSpace" />
        <add namespace="THE.Namespace" />
      </namespaces>
    </pages>
  </system.web.webPages.razor>

Use PHP to convert PNG to JPG with compression?

This is a small example that will convert 'image.png' to 'image.jpg' at 70% image quality:

<?php
$image = imagecreatefrompng('image.png');
imagejpeg($image, 'image.jpg', 70);
imagedestroy($image);
?>

Hope that helps

how to get param in method post spring mvc?

When I want to get all the POST params I am using the code below,

@RequestMapping(value = "/", method = RequestMethod.POST)
public ViewForResponseClass update(@RequestBody AClass anObject) {
    // Source..
}

I am using the @RequestBody annotation for post/put/delete http requests instead of the @RequestParam which reads the GET parameters.

How to enable file upload on React's Material UI simple input?

Here an example:

return (
    <Box alignItems='center' display='flex' justifyContent='center' flexDirection='column'>
      <Box>
        <input accept="image/*" id="upload-company-logo" type='file' hidden />
        <label htmlFor="upload-company-logo">
          <Button component="span" >
            <Paper elevation={5}>
              <Avatar src={formik.values.logo} className={classes.avatar} variant='rounded' />
            </Paper>
          </Button>
        </label>
      </Box>
    </Box>
  )

Number of rows affected by an UPDATE in PL/SQL

For those who want the results from a plain command, the solution could be:

begin
  DBMS_OUTPUT.PUT_LINE(TO_Char(SQL%ROWCOUNT)||' rows affected.');
end;

The basic problem is that SQL%ROWCOUNT is a PL/SQL variable (or function), and cannot be directly accessed from an SQL command. By using a noname PL/SQL block, this can be achieved.

... If anyone has a solution to use it in a SELECT Command, I would be interested.

Select first 4 rows of a data.frame in R

Using the index:

df[1:4,]

Where the values in the parentheses can be interpreted as either logical, numeric, or character (matching the respective names):

df[row.index, column.index]

Read help(`[`) for more detail on this subject, and also read about index matrices in the Introduction to R.

How to draw a filled circle in Java?

/***Your Code***/
public void paintComponent(Graphics g){
/***Your Code***/
    g.setColor(Color.RED);
    g.fillOval(50,50,20,20);
}

g.fillOval(x-axis,y-axis,width,height);

Retrieving a random item from ArrayList

anyItem has never been declared as a variable, so it makes sense that it causes an error. But more importantly, you have code after a return statement and this will cause an unreachable code error.

Can't find bundle for base name

java.util.MissingResourceException: Can't find bundle for base name
    org.jfree.chart.LocalizationBundle, locale en_US

To the point, the exception message tells in detail that you need to have either of the following files in the classpath:

/org/jfree/chart/LocalizationBundle.properties

or

/org/jfree/chart/LocalizationBundle_en.properties

or

/org/jfree/chart/LocalizationBundle_en_US.properties

Also see the official Java tutorial about resourcebundles for more information.

But as this is actually a 3rd party managed properties file, you shouldn't create one yourself. It should be already available in the JFreeChart JAR file. So ensure that you have it available in the classpath during runtime. Also ensure that you're using the right version, the location of the propertiesfile inside the package tree might have changed per JFreeChart version.

When executing a JAR file, you can use the -cp argument to specify the classpath. E.g.:

java -jar -cp c:/path/to/jfreechart.jar yourfile.jar

Alternatively you can specify the classpath as class-path entry in the JAR's manifest file. You can use in there relative paths which are relative to the JAR file itself. Do not use the %CLASSPATH% environment variable, it's ignored by JAR's and everything else which aren't executed with java.exe without -cp, -classpath and -jar arguments.

Modulo operator in Python

When you have the expression:

a % b = c

It really means there exists an integer n that makes c as small as possible, but non-negative.

a - n*b = c

By hand, you can just subtract 2 (or add 2 if your number is negative) over and over until the end result is the smallest positive number possible:

  3.14 % 2
= 3.14 - 1 * 2
= 1.14

Also, 3.14 % 2 * pi is interpreted as (3.14 % 2) * pi. I'm not sure if you meant to write 3.14 % (2 * pi) (in either case, the algorithm is the same. Just subtract/add until the number is as small as possible).

Making PHP var_dump() values display one line per value

var_export will give you a nice output. Examples from the docs:

$a = array (1, 2, array ("a", "b", "c"));
echo '<pre>' . var_export($a, true) . '</pre>';

Will output:

array (
  0 => 1,
  1 => 2,
  2 => 
  array (
    0 => 'a',
    1 => 'b',
    2 => 'c',
  ),
)

How to style a div to be a responsive square?

It is as easy as specifying a padding bottom the same size as the width in percent. So if you have a width of 50%, just use this example below

id or class{
    width: 50%;
    padding-bottom: 50%;
}

Here is a jsfiddle http://jsfiddle.net/kJL3u/2/

Edited version with responsive text: http://jsfiddle.net/kJL3u/394

How do I fix MSB3073 error in my post-build event?

I faced this issue recently and surprisingly only i was having this problem and none of my team members were facing this issue when building the project code.

On debugging i found that my code directory had spacing issue , It was D:\GIT Workspace\abc\xyz.

As a quick fix i changed it to D:\GITWS\abc\xyz and it solved the problem.

Editing dictionary values in a foreach loop

Call the ToList() in the foreach loop. This way we dont need a temp variable copy. It depends on Linq which is available since .Net 3.5.

using System.Linq;

foreach(string key in colStates.Keys.ToList())
{
  double  Percent = colStates[key] / TotalCount;

    if (Percent < 0.05)
    {
        OtherCount += colStates[key];
        colStates[key] = 0;
    }
}

Why check both isset() and !empty()

isset($vars[1]) AND !empty($vars[1]) is equivalent to !empty($vars[1]).

I prepared simple code to show it empirically.

Last row is undefined variable.

+-----------+---------+---------+----------+---------------------+
| Var value | empty() | isset() | !empty() | isset() && !empty() |
+-----------+---------+---------+----------+---------------------+
| ''        | true    | true    | false    | false               |
| ' '       | false   | true    | true     | true                |
| false     | true    | true    | false    | false               |
| true      | false   | true    | true     | true                |
| array ()  | true    | true    | false    | false               |
| NULL      | true    | false   | false    | false               |
| '0'       | true    | true    | false    | false               |
| 0         | true    | true    | false    | false               |
| 0.0       | true    | true    | false    | false               |
| undefined | true    | false   | false    | false               |
+-----------+---------+---------+----------+---------------------+

And code

$var1 = "";
$var2 = " ";
$var3 = FALSE;
$var4 = TRUE;
$var5 = array();
$var6 = null;
$var7 = "0";
$var8 = 0;
$var9 = 0.0;

function compare($var)
{
    print(var_export($var, true) . "|" .
        var_export(empty($var), true) . "|" .
        var_export(isset($var), true) . "|" .
        var_export(!empty($var), true) . "|" .
        var_export(isset($var) && !empty($var), true) . "\n");
}

for ($i = 1; $i <= 9; $i++) {
    $var = 'var' . $i;
    compare($$var);
}

@print(var_export($var10, true) . "|" .
    var_export(empty($var10), true) . "|" .
    var_export(isset($var10), true) . "|" .
    var_export(!empty($var10), true) . "|" .
    var_export(isset($var10) && !empty($var10), true) . "\n");

Undefined variable must be evaluated outside function, because function itself create temporary variable in the scope itself.

Typescript: Type X is missing the following properties from type Y length, pop, push, concat, and 26 more. [2740]

For me the error was caused by wrong type hint of url string. I used:

export class TodoService {

  apiUrl: String = 'https://jsonplaceholder.typicode.com/todos' // wrong uppercase String

  constructor(private httpClient: HttpClient) { }

  getTodos(): Observable<Todo[]> {
    return this.httpClient.get<Todo[]>(this.apiUrl)
  }
}

where I should have used

export class TodoService {

  apiUrl: string = 'https://jsonplaceholder.typicode.com/todos' // lowercase string!

  constructor(private httpClient: HttpClient) { }

  getTodos(): Observable<Todo[]> {
    return this.httpClient.get<Todo[]>(this.apiUrl)
  }
}

PHP max_input_vars

Use of this directive mitigates the possibility of denial of service attacks which use hash collisions. If there are more input variables than specified by this directive, an E_WARNING is issued, and further input variables are truncated from the request.

I can suggest not to extend the default value which is 1000 and extend the application functionality by serialising the request or send the request by blocks. Otherwise, you can extend this to configuration needed.

It definitely needs to set up in the php.ini

How to import Angular Material in project?

You should consider using a SharedModule for the essential material components of your app, and then import every single module you need to use into your feature modules. I wrote an article on medium explaining how to import Angular material, check it out:

https://medium.com/@benmohamehdi/how-to-import-angular-material-angular-best-practices-80d3023118de

Clear text from textarea with selenium

for java

driver.findelement(By.id('foo').clear();

or

webElement.clear();

If this element is a text entry element, this will clear the value.

How to post data to specific URL using WebClient in C#

I just found the solution and yea it was easier than I thought :)

so here is the solution:

string URI = "http://www.myurl.com/post.php";
string myParameters = "param1=value1&param2=value2&param3=value3";

using (WebClient wc = new WebClient())
{
    wc.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";
    string HtmlResult = wc.UploadString(URI, myParameters);
}

it works like charm :)

How can I SELECT multiple columns within a CASE WHEN on SQL Server?

No, CASE is a function, and can only return a single value. I think you are going to have to duplicate your CASE logic.

The other option would be to wrap the whole query with an IF and have two separate queries to return results. Without seeing the rest of the query, it's hard to say if that would work for you.

MySQL - Meaning of "PRIMARY KEY", "UNIQUE KEY" and "KEY" when used together while creating a table

A key is just a normal index. A way over simplification is to think of it like a card catalog at a library. It points MySQL in the right direction.

A unique key is also used for improved searching speed, but it has the constraint that there can be no duplicated items (there are no two x and y where x is not y and x == y).

The manual explains it as follows:

A UNIQUE index creates a constraint such that all values in the index must be distinct. An error occurs if you try to add a new row with a key value that matches an existing row. This constraint does not apply to NULL values except for the BDB storage engine. For other engines, a UNIQUE index permits multiple NULL values for columns that can contain NULL. If you specify a prefix value for a column in a UNIQUE index, the column values must be unique within the prefix.

A primary key is a 'special' unique key. It basically is a unique key, except that it's used to identify something.

The manual explains how indexes are used in general: here.

In MSSQL, the concepts are similar. There are indexes, unique constraints and primary keys.

Untested, but I believe the MSSQL equivalent is:

CREATE TABLE tmp (
  id int NOT NULL PRIMARY KEY IDENTITY,
  uid varchar(255) NOT NULL CONSTRAINT uid_unique UNIQUE,
  name varchar(255) NOT NULL,
  tag int NOT NULL DEFAULT 0,
  description varchar(255),
);

CREATE INDEX idx_name ON tmp (name);
CREATE INDEX idx_tag ON tmp (tag);

Edit: the code above is tested to be correct; however, I suspect that there's a much better syntax for doing it. Been a while since I've used SQL server, and apparently I've forgotten quite a bit :).

Using $window or $location to Redirect in AngularJS

Not sure from what version, but I use 1.3.14 and you can just use:

window.location.href = '/employee/1';

No need to inject $location or $window in the controller and no need to get the current host address.

How to get the indices list of all NaN value in numpy array?

Since x!=x returns the same boolean array with np.isnan(x) (because np.nan!=np.nan would return True), you could also write:

np.argwhere(x!=x)

However, I still recommend writing np.argwhere(np.isnan(x)) since it is more readable. I just try to provide another way to write the code in this answer.

How to disable spring security for particular url

When using permitAll it means every authenticated user, however you disabled anonymous access so that won't work.

What you want is to ignore certain URLs for this override the configure method that takes WebSecurity object and ignore the pattern.

@Override
public void configure(WebSecurity web) throws Exception {
    web.ignoring().antMatchers("/api/v1/signup");
}

And remove that line from the HttpSecurity part. This will tell Spring Security to ignore this URL and don't apply any filters to them.

What is the logic behind the "using" keyword in C++?

In C++11, the using keyword when used for type alias is identical to typedef.

7.1.3.2

A typedef-name can also be introduced by an alias-declaration. The identifier following the using keyword becomes a typedef-name and the optional attribute-specifier-seq following the identifier appertains to that typedef-name. It has the same semantics as if it were introduced by the typedef specifier. In particular, it does not define a new type and it shall not appear in the type-id.

Bjarne Stroustrup provides a practical example:

typedef void (*PFD)(double);    // C style typedef to make `PFD` a pointer to a function returning void and accepting double
using PF = void (*)(double);    // `using`-based equivalent of the typedef above
using P = [](double)->void; // using plus suffix return type, syntax error
using P = auto(double)->void // Fixed thanks to DyP

Pre-C++11, the using keyword can bring member functions into scope. In C++11, you can now do this for constructors (another Bjarne Stroustrup example):

class Derived : public Base { 
public: 
    using Base::f;    // lift Base's f into Derived's scope -- works in C++98
    void f(char);     // provide a new f 
    void f(int);      // prefer this f to Base::f(int) 

    using Base::Base; // lift Base constructors Derived's scope -- C++11 only
    Derived(char);    // provide a new constructor 
    Derived(int);     // prefer this constructor to Base::Base(int) 
    // ...
}; 

Ben Voight provides a pretty good reason behind the rationale of not introducing a new keyword or new syntax. The standard wants to avoid breaking old code as much as possible. This is why in proposal documents you will see sections like Impact on the Standard, Design decisions, and how they might affect older code. There are situations when a proposal seems like a really good idea but might not have traction because it would be too difficult to implement, too confusing, or would contradict old code.


Here is an old paper from 2003 n1449. The rationale seems to be related to templates. Warning: there may be typos due to copying over from PDF.

First let’s consider a toy example:

template <typename T>
class MyAlloc {/*...*/};

template <typename T, class A>
class MyVector {/*...*/};

template <typename T>

struct Vec {
typedef MyVector<T, MyAlloc<T> > type;
};
Vec<int>::type p; // sample usage

The fundamental problem with this idiom, and the main motivating fact for this proposal, is that the idiom causes the template parameters to appear in non-deducible context. That is, it will not be possible to call the function foo below without explicitly specifying template arguments.

template <typename T> void foo (Vec<T>::type&);

So, the syntax is somewhat ugly. We would rather avoid the nested ::type We’d prefer something like the following:

template <typename T>
using Vec = MyVector<T, MyAlloc<T> >; //defined in section 2 below
Vec<int> p; // sample usage

Note that we specifically avoid the term “typedef template” and introduce the new syntax involving the pair “using” and “=” to help avoid confusion: we are not defining any types here, we are introducing a synonym (i.e. alias) for an abstraction of a type-id (i.e. type expression) involving template parameters. If the template parameters are used in deducible contexts in the type expression then whenever the template alias is used to form a template-id, the values of the corresponding template parameters can be deduced – more on this will follow. In any case, it is now possible to write generic functions which operate on Vec<T> in deducible context, and the syntax is improved as well. For example we could rewrite foo as:

template <typename T> void foo (Vec<T>&);

We underscore here that one of the primary reasons for proposing template aliases was so that argument deduction and the call to foo(p) will succeed.


The follow-up paper n1489 explains why using instead of using typedef:

It has been suggested to (re)use the keyword typedef — as done in the paper [4] — to introduce template aliases:

template<class T> 
    typedef std::vector<T, MyAllocator<T> > Vec;

That notation has the advantage of using a keyword already known to introduce a type alias. However, it also displays several disavantages among which the confusion of using a keyword known to introduce an alias for a type-name in a context where the alias does not designate a type, but a template; Vec is not an alias for a type, and should not be taken for a typedef-name. The name Vec is a name for the family std::vector< [bullet] , MyAllocator< [bullet] > > – where the bullet is a placeholder for a type-name. Consequently we do not propose the “typedef” syntax. On the other hand the sentence

template<class T>
    using Vec = std::vector<T, MyAllocator<T> >;

can be read/interpreted as: from now on, I’ll be using Vec<T> as a synonym for std::vector<T, MyAllocator<T> >. With that reading, the new syntax for aliasing seems reasonably logical.

I think the important distinction is made here, aliases instead of types. Another quote from the same document:

An alias-declaration is a declaration, and not a definition. An alias- declaration introduces a name into a declarative region as an alias for the type designated by the right-hand-side of the declaration. The core of this proposal concerns itself with type name aliases, but the notation can obviously be generalized to provide alternate spellings of namespace-aliasing or naming set of overloaded functions (see ? 2.3 for further discussion). [My note: That section discusses what that syntax can look like and reasons why it isn't part of the proposal.] It may be noted that the grammar production alias-declaration is acceptable anywhere a typedef declaration or a namespace-alias-definition is acceptable.

Summary, for the role of using:

  • template aliases (or template typedefs, the former is preferred namewise)
  • namespace aliases (i.e., namespace PO = boost::program_options and using PO = ... equivalent)
  • the document says A typedef declaration can be viewed as a special case of non-template alias-declaration. It's an aesthetic change, and is considered identical in this case.
  • bringing something into scope (for example, namespace std into the global scope), member functions, inheriting constructors

It cannot be used for:

int i;
using r = i; // compile-error

Instead do:

using r = decltype(i);

Naming a set of overloads.

// bring cos into scope
using std::cos;

// invalid syntax
using std::cos(double);

// not allowed, instead use Bjarne Stroustrup function pointer alias example
using test = std::cos(double);

Saving an Excel sheet in a current directory with VBA

I am not clear exactly what your situation requires but the following may get you started. The key here is using ThisWorkbook.Path to get a relative file path:

Sub SaveToRelativePath()
    Dim relativePath As String
    relativePath = ThisWorkbook.Path & Application.PathSeparator & ActiveWorkbook.Name
    ActiveWorkbook.SaveAs Filename:=relativePath
End Sub

Django template how to look up a dictionary value with a variable

Fetch both the key and the value from the dictionary in the loop:

{% for key, value in mydict.items %}
    {{ value }}
{% endfor %}

I find this easier to read and it avoids the need for special coding. I usually need the key and the value inside the loop anyway.

Linux Shell Script For Each File in a Directory Grab the filename and execute a program

for i in *.xls ; do 
  [[ -f "$i" ]] || continue
  xls2csv "$i" "${i%.xls}.csv"
done

The first line in the do checks if the "matching" file really exists, because in case nothing matches in your for, the do will be executed with "*.xls" as $i. This could be horrible for your xls2csv.

Java optional parameters

VarArgs and overloading have been mentioned. Another option is a Bloch Builder pattern, which would look something like this:

 MyObject my = new MyObjectBuilder().setParam1(value)
                                 .setParam3(otherValue)
                                 .setParam6(thirdValue)
                                 .build();

Although that pattern would be most appropriate for when you need optional parameters in a constructor.

How to redirect to another page using PHP

You could use a function similar to:

function redirect($url) {
    ob_start();
    header('Location: '.$url);
    ob_end_flush();
    die();
}

Worth noting, you should always use either ob_flush() or ob_start() at the beginning of your header('location: ...'); functions, and you should always follow them with a die() or exit() function to prevent further code execution.

Here's a more detailed guide than any of the other answers have mentioned: http://www.exchangecore.com/blog/how-redirect-using-php/

This guide includes reasons for using die() / exit() functions in your redirects, as well as when to use ob_flush() vs ob_start(), and some potential errors that the others answers have left out at this point.

How to programmatically set style attribute in a view

First of all, you don't need to use a layout inflater to create a simple Button. You can just use:

button = new Button(context);

If you want to style the button you have 2 choices: the simplest one is to just specify all the elements in code, like many of the other answers suggest:

button.setTextColor(Color.RED);
button.setTextSize(TypedValue.COMPLEX_UNIT_SP, 18);

The other option is to define the style in XML, and apply it to the button. In the general case, you can use a ContextThemeWrapper for this:

ContextThemeWrapper newContext = new ContextThemeWrapper(baseContext, R.style.MyStyle);
button = new Button(newContext);

To change the text-related attributes on a TextView (or its subclasses like Button) there is a special method:

button.setTextAppearance(R.style.MyTextStyle);

Or, if you need to support devices pre API-23 (Android 6.0)

button.setTextAppearance(context, R.style.MyTextStyle);

This method cannot be used to change all attributes; for example to change padding you need to use a ContextThemeWrapper. But for text color, size, etc. you can use setTextAppearance.

AngularJS - get element attributes values

_x000D_
_x000D_
function onContentLoad() {_x000D_
  var item = document.getElementById("id1");_x000D_
  var x = item.dataset.x;_x000D_
  var data = item.dataset.myData;_x000D_
_x000D_
  var resX = document.getElementById("resX");_x000D_
  var resData = document.getElementById("resData");_x000D_
_x000D_
  resX.innerText = x;_x000D_
  resData.innerText = data;_x000D_
_x000D_
  console.log(x);_x000D_
  console.log(data);_x000D_
}
_x000D_
<body onload="onContentLoad()">_x000D_
  <div id="id1" data-x="a" data-my-data="b"></div>_x000D_
_x000D_
  Read 'x':_x000D_
  <label id="resX"></label>_x000D_
  <br/>Read 'my-data':_x000D_
  <label id="resData"></label>_x000D_
</body>
_x000D_
_x000D_
_x000D_

ValidateRequest="false" doesn't work in Asp.Net 4

There is a way to turn the validation back to 2.0 for one page. Just add the below code to your web.config:

<configuration>
    <location path="XX/YY">
        <system.web>
            <httpRuntime requestValidationMode="2.0" />
        </system.web>
    </location>

    ...
    the rest of your configuration
    ...

</configuration>