Programs & Examples On #Maintenance mode

Is there an easy way to strike through text in an app widget?

You can use this:

remoteviews.setInt(R.id.YourTextView, "setPaintFlags", Paint.STRIKE_THRU_TEXT_FLAG | Paint.ANTI_ALIAS_FLAG);

Of course you can also add other flags from the android.graphics.Paint class.

Generate random numbers using C++11 random library

You've got two common situations. The first is that you want random numbers and aren't too fussed about the quality or execution speed. In that case, use the following macro

#define uniform() (rand()/(RAND_MAX + 1.0))

that gives you p in the range 0 to 1 - epsilon (unless RAND_MAX is bigger than the precision of a double, but worry about that when you come to it).

int x = (int) (uniform() * N);

Now gives a random integer on 0 to N -1.

If you need other distributions, you have to transform p. Or sometimes it's easier to call uniform() several times.

If you want repeatable behaviour, seed with a constant, otherwise seed with a call to time().

Now if you are bothered about quality or run time performance, rewrite uniform(). But otherwise don't touch the code. Always keep uniform() on 0 to 1 minus epsilon. Now you can wrap the C++ random number library to create a better uniform(), but that's a sort of medium-level option. If you are bothered about the characteristics of the RNG, then it's also worth investing a bit of time to understand how the underlying methods work, then provide one. So you've got complete control of the code, and you can guarantee that with the same seed, the sequence will always be exactly the same, regardless of platform or which version of C++ you are linking to.

What event handler to use for ComboBox Item Selected (Selected Item not necessarily changed)

private void OnDropDownClosed(object sender, EventArgs e)
{ 
     if (combobox.SelectedItem == null) return;
     // Do actions
}

Pass Additional ViewData to a Strongly-Typed Partial View

I think this should work no?

ViewData["currentIndex"] = index;

Firebase Storage How to store and Retrieve images

Using Base64 string in JSON will be very heavy. The parser has to do a lot of heavy lifting. Currently, Fresco only supports base supports Base64. Better you put something on Amazon Cloud or Firebase Cloud. And get an image as a URL. So that you can use Picasso or Glide for caching.

Append same text to every cell in a column in Excel

Select the range of cells, type in the value and press Ctrl + Enter.

This, of course, is true if you want to do it manually.

jQuery AJAX single file upload

A. Grab file data from the file field

The first thing to do is bind a function to the change event on your file field and a function for grabbing the file data:

// Variable to store your files
var files;

// Add events
$('input[type=file]').on('change', prepareUpload);

// Grab the files and set them to our variable
function prepareUpload(event)
{
  files = event.target.files;
}

This saves the file data to a file variable for later use.

B. Handle the file upload on submit

When the form is submitted you need to handle the file upload in its own AJAX request. Add the following binding and function:

$('form').on('submit', uploadFiles);

// Catch the form submit and upload the files
function uploadFiles(event)
{
  event.stopPropagation(); // Stop stuff happening
    event.preventDefault(); // Totally stop stuff happening

// START A LOADING SPINNER HERE

// Create a formdata object and add the files
var data = new FormData();
$.each(files, function(key, value)
{
    data.append(key, value);
});

$.ajax({
    url: 'submit.php?files',
    type: 'POST',
    data: data,
    cache: false,
    dataType: 'json',
    processData: false, // Don't process the files
    contentType: false, // Set content type to false as jQuery will tell the server its a query string request
    success: function(data, textStatus, jqXHR)
    {
        if(typeof data.error === 'undefined')
        {
            // Success so call function to process the form
            submitForm(event, data);
        }
        else
        {
            // Handle errors here
            console.log('ERRORS: ' + data.error);
        }
    },
    error: function(jqXHR, textStatus, errorThrown)
    {
        // Handle errors here
        console.log('ERRORS: ' + textStatus);
        // STOP LOADING SPINNER
    }
});
}

What this function does is create a new formData object and appends each file to it. It then passes that data as a request to the server. 2 attributes need to be set to false:

  • processData - Because jQuery will convert the files arrays into strings and the server can't pick it up.
  • contentType - Set this to false because jQuery defaults to application/x-www-form-urlencoded and doesn't send the files. Also setting it to multipart/form-data doesn't seem to work either.

C. Upload the files

Quick and dirty php script to upload the files and pass back some info:

<?php // You need to add server side validation and better error handling here

$data = array();

if(isset($_GET['files']))
{  
$error = false;
$files = array();

$uploaddir = './uploads/';
foreach($_FILES as $file)
{
    if(move_uploaded_file($file['tmp_name'], $uploaddir .basename($file['name'])))
    {
        $files[] = $uploaddir .$file['name'];
    }
    else
    {
        $error = true;
    }
}
$data = ($error) ? array('error' => 'There was an error uploading your files') : array('files' => $files);
}
else
{
    $data = array('success' => 'Form was submitted', 'formData' => $_POST);
}

echo json_encode($data);

?>

IMP: Don't use this, write your own.

D. Handle the form submit

The success method of the upload function passes the data sent back from the server to the submit function. You can then pass that to the server as part of your post:

function submitForm(event, data)
{
  // Create a jQuery object from the form
$form = $(event.target);

// Serialize the form data
var formData = $form.serialize();

// You should sterilise the file names
$.each(data.files, function(key, value)
{
    formData = formData + '&filenames[]=' + value;
});

$.ajax({
    url: 'submit.php',
    type: 'POST',
    data: formData,
    cache: false,
    dataType: 'json',
    success: function(data, textStatus, jqXHR)
    {
        if(typeof data.error === 'undefined')
        {
            // Success so call function to process the form
            console.log('SUCCESS: ' + data.success);
        }
        else
        {
            // Handle errors here
            console.log('ERRORS: ' + data.error);
        }
    },
    error: function(jqXHR, textStatus, errorThrown)
    {
        // Handle errors here
        console.log('ERRORS: ' + textStatus);
    },
    complete: function()
    {
        // STOP LOADING SPINNER
    }
});
}

Final note

This script is an example only, you'll need to handle both server and client side validation and some way to notify users that the file upload is happening. I made a project for it on Github if you want to see it working.

Referenced From

What is the best way to uninstall gems from a rails3 project?

I seemed to solve this by manually removing the unicorn gem via bundler ("sudo bundler exec gem uninstall unicorn"), then rebundling ("sudo bundle install").

Not sure why it happened though, although the above fix does seem to work.

Send email using java

The following code works very well with Google SMTP server. You need to supply your Google username and password.

import com.sun.mail.smtp.SMTPTransport;
import java.security.Security;
import java.util.Date;
import java.util.Properties;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

/**
 *
 * @author doraemon
 */
public class GoogleMail {
    private GoogleMail() {
    }

    /**
     * Send email using GMail SMTP server.
     *
     * @param username GMail username
     * @param password GMail password
     * @param recipientEmail TO recipient
     * @param title title of the message
     * @param message message to be sent
     * @throws AddressException if the email address parse failed
     * @throws MessagingException if the connection is dead or not in the connected state or if the message is not a MimeMessage
     */
    public static void Send(final String username, final String password, String recipientEmail, String title, String message) throws AddressException, MessagingException {
        GoogleMail.Send(username, password, recipientEmail, "", title, message);
    }

    /**
     * Send email using GMail SMTP server.
     *
     * @param username GMail username
     * @param password GMail password
     * @param recipientEmail TO recipient
     * @param ccEmail CC recipient. Can be empty if there is no CC recipient
     * @param title title of the message
     * @param message message to be sent
     * @throws AddressException if the email address parse failed
     * @throws MessagingException if the connection is dead or not in the connected state or if the message is not a MimeMessage
     */
    public static void Send(final String username, final String password, String recipientEmail, String ccEmail, String title, String message) throws AddressException, MessagingException {
        Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
        final String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";

        // Get a Properties object
        Properties props = System.getProperties();
        props.setProperty("mail.smtps.host", "smtp.gmail.com");
        props.setProperty("mail.smtp.socketFactory.class", SSL_FACTORY);
        props.setProperty("mail.smtp.socketFactory.fallback", "false");
        props.setProperty("mail.smtp.port", "465");
        props.setProperty("mail.smtp.socketFactory.port", "465");
        props.setProperty("mail.smtps.auth", "true");

        /*
        If set to false, the QUIT command is sent and the connection is immediately closed. If set 
        to true (the default), causes the transport to wait for the response to the QUIT command.

        ref :   http://java.sun.com/products/javamail/javadocs/com/sun/mail/smtp/package-summary.html
                http://forum.java.sun.com/thread.jspa?threadID=5205249
                smtpsend.java - demo program from javamail
        */
        props.put("mail.smtps.quitwait", "false");

        Session session = Session.getInstance(props, null);

        // -- Create a new message --
        final MimeMessage msg = new MimeMessage(session);

        // -- Set the FROM and TO fields --
        msg.setFrom(new InternetAddress(username + "@gmail.com"));
        msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse(recipientEmail, false));

        if (ccEmail.length() > 0) {
            msg.setRecipients(Message.RecipientType.CC, InternetAddress.parse(ccEmail, false));
        }

        msg.setSubject(title);
        msg.setText(message, "utf-8");
        msg.setSentDate(new Date());

        SMTPTransport t = (SMTPTransport)session.getTransport("smtps");

        t.connect("smtp.gmail.com", username, password);
        t.sendMessage(msg, msg.getAllRecipients());      
        t.close();
    }
}

Update on 11 December 2015

Username + password is no longer a recommended solution. This is due to

I tried this and Gmail sent the email used as username in this code an email saying that We recently blocked a sign-in attempt to your Google Account, and directed me to this support page: support.google.com/accounts/answer/6010255 so it looks for it to work, the email account being used to send needs to reduce their own security

Google had released Gmail API - https://developers.google.com/gmail/api/?hl=en. We should use oAuth2 method, instead of username + password.

Here's the code snippet to work with Gmail API.

GoogleMail.java

import com.google.api.client.util.Base64;
import com.google.api.services.gmail.Gmail;
import com.google.api.services.gmail.model.Message;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Properties;

import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

/**
 *
 * @author doraemon
 */
public class GoogleMail {
    private GoogleMail() {
    }

    private static MimeMessage createEmail(String to, String cc, String from, String subject, String bodyText) throws MessagingException {
        Properties props = new Properties();
        Session session = Session.getDefaultInstance(props, null);

        MimeMessage email = new MimeMessage(session);
        InternetAddress tAddress = new InternetAddress(to);
        InternetAddress cAddress = cc.isEmpty() ? null : new InternetAddress(cc);
        InternetAddress fAddress = new InternetAddress(from);

        email.setFrom(fAddress);
        if (cAddress != null) {
            email.addRecipient(javax.mail.Message.RecipientType.CC, cAddress);
        }
        email.addRecipient(javax.mail.Message.RecipientType.TO, tAddress);
        email.setSubject(subject);
        email.setText(bodyText);
        return email;
    }

    private static Message createMessageWithEmail(MimeMessage email) throws MessagingException, IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        email.writeTo(baos);
        String encodedEmail = Base64.encodeBase64URLSafeString(baos.toByteArray());
        Message message = new Message();
        message.setRaw(encodedEmail);
        return message;
    }

    public static void Send(Gmail service, String recipientEmail, String ccEmail, String fromEmail, String title, String message) throws IOException, MessagingException {
        Message m = createMessageWithEmail(createEmail(recipientEmail, ccEmail, fromEmail, title, message));
        service.users().messages().send("me", m).execute();
    }
}

To construct an authorized Gmail service through oAuth2, here's the code snippet.

Utils.java

import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.extensions.jetty.auth.oauth2.LocalServerReceiver;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.client.util.store.FileDataStoreFactory;
import com.google.api.services.gmail.Gmail;
import com.google.api.services.gmail.GmailScopes;
import com.google.api.services.oauth2.Oauth2;
import com.google.api.services.oauth2.model.Userinfoplus;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.security.GeneralSecurityException;
import java.util.HashSet;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.yccheok.jstock.engine.Pair;

/**
 *
 * @author yccheok
 */
public class Utils {
    /** Global instance of the JSON factory. */
    private static final GsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();

    /** Global instance of the HTTP transport. */
    private static HttpTransport httpTransport;

    private static final Log log = LogFactory.getLog(Utils.class);

    static {
        try {
            // initialize the transport
            httpTransport = GoogleNetHttpTransport.newTrustedTransport();

        } catch (IOException ex) {
            log.error(null, ex);
        } catch (GeneralSecurityException ex) {
            log.error(null, ex);
        }
    }

    private static File getGmailDataDirectory() {
        return new File(org.yccheok.jstock.gui.Utils.getUserDataDirectory() + "authentication" + File.separator + "gmail");
    }

    /**
     * Send a request to the UserInfo API to retrieve the user's information.
     *
     * @param credentials OAuth 2.0 credentials to authorize the request.
     * @return User's information.
     * @throws java.io.IOException
     */
    public static Userinfoplus getUserInfo(Credential credentials) throws IOException
    {
        Oauth2 userInfoService =
            new Oauth2.Builder(httpTransport, JSON_FACTORY, credentials).setApplicationName("JStock").build();
        Userinfoplus userInfo  = userInfoService.userinfo().get().execute();
        return userInfo;
    }

    public static String loadEmail(File dataStoreDirectory)  {
        File file = new File(dataStoreDirectory, "email");
        try {
            return new String(Files.readAllBytes(Paths.get(file.toURI())), "UTF-8");
        } catch (IOException ex) {
            log.error(null, ex);
            return null;
        }
    }

    public static boolean saveEmail(File dataStoreDirectory, String email) {
        File file = new File(dataStoreDirectory, "email");
        try {
            //If the constructor throws an exception, the finally block will NOT execute
            BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file), "UTF-8"));
            try {
                writer.write(email);
            } finally {
                writer.close();
            }
            return true;
        } catch (IOException ex){
            log.error(null, ex);
            return false;
        }
    }

    public static void logoutGmail() {
        File credential = new File(getGmailDataDirectory(), "StoredCredential");
        File email = new File(getGmailDataDirectory(), "email");
        credential.delete();
        email.delete();
    }

    public static Pair<Pair<Credential, String>, Boolean> authorizeGmail() throws Exception {
        // Ask for only the permissions you need. Asking for more permissions will
        // reduce the number of users who finish the process for giving you access
        // to their accounts. It will also increase the amount of effort you will
        // have to spend explaining to users what you are doing with their data.
        // Here we are listing all of the available scopes. You should remove scopes
        // that you are not actually using.
        Set<String> scopes = new HashSet<>();

        // We would like to display what email this credential associated to.
        scopes.add("email");

        scopes.add(GmailScopes.GMAIL_SEND);

        // load client secrets
        GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(Utils.JSON_FACTORY,
            new InputStreamReader(Utils.class.getResourceAsStream("/assets/authentication/gmail/client_secrets.json")));

        return authorize(clientSecrets, scopes, getGmailDataDirectory());
    }

    /** Authorizes the installed application to access user's protected data.
     * @return 
     * @throws java.lang.Exception */
    private static Pair<Pair<Credential, String>, Boolean> authorize(GoogleClientSecrets clientSecrets, Set<String> scopes, File dataStoreDirectory) throws Exception {
        // Set up authorization code flow.

        GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
            httpTransport, JSON_FACTORY, clientSecrets, scopes)
            .setDataStoreFactory(new FileDataStoreFactory(dataStoreDirectory))
            .build();
        // authorize
        return new MyAuthorizationCodeInstalledApp(flow, new LocalServerReceiver()).authorize("user");
    }

    public static Gmail getGmail(Credential credential) {
        Gmail service = new Gmail.Builder(httpTransport, JSON_FACTORY, credential).setApplicationName("JStock").build();
        return service;        
    }
}

To provide a user friendly way of oAuth2 authentication, I made use of JavaFX, to display the following input dialog

enter image description here

The key to display user friendly oAuth2 dialog can be found in MyAuthorizationCodeInstalledApp.java and SimpleSwingBrowser.java

How to rename a table in SQL Server?

If you try exec sp_rename and receieve a LockMatchID error then it might help to add a use [database] statement first:

I tried

 exec sp_rename '[database_name].[dbo].[table_name]', 'new_table_name';
 -- Invalid EXECUTE statement using object "Object", method "LockMatchID".

What I had to do to fix it was to rewrite it to:

use database_name
exec sp_rename '[dbo].[table_name]', 'new_table_name';

When should I write the keyword 'inline' for a function/method?

When one should inline :

1.When one want to avoid overhead of things happening when function is called like parameter passing , control transfer, control return etc.

2.The function should be small,frequently called and making inline is really advantageous since as per 80-20 rule,try to make those function inline which has major impact on program performance.

As we know that inline is just a request to compiler similar to register and it will cost you at Object code size.

SQL query return data from multiple tables

Part 3 - Tricks and Efficient Code

MySQL in() efficiency

I thought I would add some extra bits, for tips and tricks that have come up.

One question I see come up a fair bit, is How do I get non-matching rows from two tables and I see the answer most commonly accepted as something like the following (based on our cars and brands table - which has Holden listed as a brand, but does not appear in the cars table):

select
    a.ID,
    a.brand
from
    brands a
where
    a.ID not in(select brand from cars)

And yes it will work.

+----+--------+
| ID | brand  |
+----+--------+
|  6 | Holden |
+----+--------+
1 row in set (0.00 sec)

However it is not efficient in some database. Here is a link to a Stack Overflow question asking about it, and here is an excellent in depth article if you want to get into the nitty gritty.

The short answer is, if the optimiser doesn't handle it efficiently, it may be much better to use a query like the following to get non matched rows:

select
    a.brand
from
    brands a
        left join cars b
            on a.id=b.brand
where
    b.brand is null

+--------+
| brand  |
+--------+
| Holden |
+--------+
1 row in set (0.00 sec)

Update Table with same table in subquery

Ahhh, another oldie but goodie - the old You can't specify target table 'brands' for update in FROM clause.

MySQL will not allow you to run an update... query with a subselect on the same table. Now, you might be thinking, why not just slap it into the where clause right? But what if you want to update only the row with the max() date amoung a bunch of other rows? You can't exactly do that in a where clause.

update 
    brands 
set 
    brand='Holden' 
where 
    id=
        (select 
            id 
        from 
            brands 
        where 
            id=6);
ERROR 1093 (HY000): You can't specify target table 'brands' 
for update in FROM clause

So, we can't do that eh? Well, not exactly. There is a sneaky workaround that a surprisingly large number of users don't know about - though it does include some hackery that you will need to pay attention to.

You can stick the subquery within another subquery, which puts enough of a gap between the two queries so that it will work. However, note that it might be safest to stick the query within a transaction - this will prevent any other changes being made to the tables while the query is running.

update 
    brands 
set 
    brand='Holden' 
where id=
    (select 
        id 
    from 
        (select 
            id 
        from 
            brands 
        where 
            id=6
        ) 
    as updateTable);

Query OK, 0 rows affected (0.02 sec)
Rows matched: 1  Changed: 0  Warnings: 0

How to programmatically set the SSLContext of a JAX-WS client?

The above is fine (as I said in comment) unless your WSDL is accessible with https:// too.

Here is my workaround for this:

Set you SSLSocketFactory as default:

HttpsURLConnection.setDefaultSSLSocketFactory(...);

For Apache CXF which I use you need also add these lines to your config:

<http-conf:conduit name="*.http-conduit">
  <http-conf:tlsClientParameters useHttpsURLConnectionDefaultSslSocketFactory="true" />
<http-conf:conduit>

deleted object would be re-saved by cascade (remove deleted object from associations)

If you don't know, which collection holds your object

In my case it was really hard to apply TomAnderson's solution, since I didn't know what is the collection, which holds a link to an object, so here's the way to know, which objects holds the link to the deleted one: in the debugger you should enter the lowest execution stack level before the exception is thrown, there should be a variable called entityEntry, so you get a PersistenceContext object from this variable: entityEntry.persistenceContext.

For me persistenceContext was an instance of StatefulPersistenceContext and this implementation has private field parentsByChild, from which you can retrieve information about the collection, which contains the element.

I was using Eclipse debugger, so it was kinda hard to retrieve this private field in a straight way, so I used Detail Formatter (How can I watch private fields of other objects directly in the IDE when debugging?)

After getting this information, TomAnderson's solution can be applied.

How can I start PostgreSQL server on Mac OS X?

There are two primary components to PostgreSQL: the database server and a client.

There is an included client via the CLI, or like me, you might be used to tools like phpMyAdmin, so it requires a separate GUI client.

For example, on macOS: install Postgres.app which is ~65 MB from: https://postgresapp.com/

Then follow these instructions:

  • install and initialise the server with the button on the right.
  • update your $PATH using terminal: sudo mkdir -p /etc/paths.d && echo /Applications/Postgres.app/Contents/Versions/latest/bin | sudo tee /etc/paths.d/postgresapp
  • and finally, install the pgAdmin GUI which is about ~100 MB from: https://www.pgadmin.org/download/pgadmin-4-macos/

Deck of cards JAVA

There is something wrong with your design. Try to make your classes represent real world things. For example:

  • The class Card should represent one card, that is the nature of a "Card". The Card class does not need to know about Decks.
  • The Deck class should contain 52 Card objects (plus jokers?).

Can .NET load and parse a properties file equivalent to Java Properties class?

Yeah there's no built in classes to do this that I'm aware of.

But that shouldn't really be an issue should it? It looks easy enough to parse just by storing the result of Stream.ReadToEnd() in a string, splitting based on new lines and then splitting each record on the = character. What you'd be left with is a bunch of key value pairs which you can easily toss into a dictionary.

Here's an example that might work for you:

public static Dictionary<string, string> GetProperties(string path)
{
    string fileData = "";
    using (StreamReader sr = new StreamReader(path))
    {
        fileData = sr.ReadToEnd().Replace("\r", "");
    }
    Dictionary<string, string> Properties = new Dictionary<string, string>();
    string[] kvp;
    string[] records = fileData.Split("\n".ToCharArray());
    foreach (string record in records)
    {
        kvp = record.Split("=".ToCharArray());
        Properties.Add(kvp[0], kvp[1]);
    }
    return Properties;
}

Here's an example of how to use it:

Dictionary<string,string> Properties = GetProperties("data.txt");
Console.WriteLine("Hello: " + Properties["Hello"]);
Console.ReadKey();

How to create a template function within a class? (C++)

Your guess is the correct one. The only thing you have to remember is that the member function template definition (in addition to the declaration) should be in the header file, not the cpp, though it does not have to be in the body of the class declaration itself.

How to determine an object's class?

Any use of any of the methods suggested is considered a code smell which is based in a bad OO design.

If your design is good, you should not find yourself needing to use getClass() or instanceof.

Any of the suggested methods will do, but just something to keep in mind, design-wise.

XML Schema Validation : Cannot find the declaration of element

cvc-elt.1: Cannot find the declaration of element 'Root'. [7]

Your schemaLocation attribute on the root element should be xsi:schemaLocation, and you need to fix it to use the right namespace.

You should probably change the targetNamespace of the schema and the xmlns of the document to http://myNameSpace.com (since namespaces are supposed to be valid URIs, which Test.Namespace isn't, though urn:Test.Namespace would be ok). Once you do that it should find the schema. The point is that all three of the schema's target namespace, the document's namespace, and the namespace for which you're giving the schema location must be the same.

(though it still won't validate as your <element2> contains an <element3> in the document where the schema expects item)

'adb' is not recognized as an internal or external command, operable program or batch file

I did this on Windows 7, by going to:

Start > Control Panel > System > Advanced System Settings > Environment Variables...

In this Environment Variables window, in the User variables for (your-username) highlight Path and click Edit...

You then need to append a ; if there isn't already one at the end of the Variable value field, and then append C:\Users\<your-username>\AppData\Local\Android\sdk\platform-tools; to that same field.

Then click the three OK buttons to get out.

If you already have a Command Prompt window open, close it then re-open and the adb devices command should then work.

Apache is "Unable to initialize module" because of module's and PHP's API don't match after changing the PHP configuration

When you update the version of PHP (especially when going from version X.Y to version X.Z), you must update the PHP extensions as well.


This is because PHP extensions are developped in C, and are "close" to the internals of PHP -- which means that, if the APIs of those internals change, the extension must be re-compiled, to use the new versions.

And, between PHP 5.2 and PHP 5.3, for what I remember, there have been some modifications in the internal data-structures used by the PHP engine -- which means extensions must be re-compiled, in order to match that new version of those data-structures.


How to update your PHP extensions will depend on which system you are using.

If you are on windows, you can find the .dll for some extensions here : http://downloads.php.net/pierre/
For more informations about the different versions, you can take a look at what's said on the left-sidebar of windows.php.net.

If you are on Linux, you must either :

  • Check what your distribution provides
  • Or use the pecl command, to re-download the sources of the extensions in question, and re-compile them.

How to get user agent in PHP

You could also use the php native funcion get_browser()

IMPORTANT NOTE: You should have a browscap.ini file.

read file in classpath

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

public class readFile {
    /**
     * feel free to make any modification I have have been here so I feel you
     * 
     * @param args
     * @throws InterruptedException
     */
    public static void main(String[] args) throws InterruptedException {
        File dir = new File(".");// read file from same directory as source //
        if (dir.isDirectory()) {
            File[] files = dir.listFiles();
            for (File file : files) {
                // if you wanna read file name with txt files
                if (file.getName().contains("txt")) {
                    System.out.println(file.getName());
                }

                // if you want to open text file and read each line then
                if (file.getName().contains("txt")) {
                    try {
                        // FileReader reads text files in the default encoding.
                        FileReader fileReader = new FileReader(
                                file.getAbsolutePath());
                        // Always wrap FileReader in BufferedReader.
                        BufferedReader bufferedReader = new BufferedReader(
                                fileReader);
                        String line;
                        // get file details and get info you need.
                        while ((line = bufferedReader.readLine()) != null) {
                            System.out.println(line);
                            // here you can say...
                            // System.out.println(line.substring(0, 10)); this
                            // prints from 0 to 10 indext
                        }
                    } catch (FileNotFoundException ex) {
                        System.out.println("Unable to open file '"
                                + file.getName() + "'");
                    } catch (IOException ex) {
                        System.out.println("Error reading file '"
                                + file.getName() + "'");
                        // Or we could just do this:
                        ex.printStackTrace();
                    }
                }
            }
        }

    }`enter code here`

}

Windows.history.back() + location.reload() jquery

Try these ...

Option1

window.location=document.referrer;

Option2

window.location.reload(history.back());

Loading scripts after page load?

Focusing on one of the accepted answer's jQuery solutions, $.getScript() is an .ajax() request in disguise. It allows to execute other function on success by adding a second parameter:

$.getScript(url, function() {console.log('loaded script!')})

Or on the request's handlers themselves, i.e. success (.done() - script was loaded) or failure (.fail()):

_x000D_
_x000D_
$.getScript(_x000D_
    "https://code.jquery.com/color/jquery.color.js",_x000D_
    () => console.log('loaded script!')_x000D_
  ).done((script,textStatus ) => {_x000D_
    console.log( textStatus );_x000D_
    $(".block").animate({backgroundColor: "green"}, 1000);_x000D_
  }).fail(( jqxhr, settings, exception ) => {_x000D_
    console.log(exception + ': ' + jqxhr.status);_x000D_
  }_x000D_
);
_x000D_
.block {background-color: blue;width: 50vw;height: 50vh;margin: 1rem;}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<div class="block"></div>
_x000D_
_x000D_
_x000D_

Find the last time table was updated

Find last time of update on a table

SELECT
tbl.name
,ius.last_user_update
,ius.user_updates
,ius.last_user_seek
,ius.last_user_scan
,ius.last_user_lookup
,ius.user_seeks
,ius.user_scans
,ius.user_lookups
FROM
sys.dm_db_index_usage_stats ius INNER JOIN
sys.tables tbl ON (tbl.OBJECT_ID = ius.OBJECT_ID)
WHERE ius.database_id = DB_ID()

http://www.sqlserver-dba.com/2012/10/sql-server-find-last-time-of-update-on-a-table.html

How do I open workbook programmatically as read-only?

Check out the language reference:

http://msdn.microsoft.com/en-us/library/aa195811(office.11).aspx

expression.Open(FileName, UpdateLinks, ReadOnly, Format, Password, WriteResPassword, IgnoreReadOnlyRecommended, Origin, Delimiter, Editable, Notify, Converter, AddToMru, Local, CorruptLoad)

How to run test methods in specific order in JUnit4?

If the order is important, you should make the order yourself.

@Test public void test1() { ... }
@Test public void test2() { test1(); ... }

In particular, you should list some or all possible order permutations to test, if necessary.

For example,

void test1(); 
void test2(); 
void test3(); 


@Test
public void testOrder1() { test1(); test3(); }

@Test(expected = Exception.class)
public void testOrder2() { test2(); test3(); test1(); }

@Test(expected = NullPointerException.class)
public void testOrder3() { test3(); test1(); test2(); }

Or, a full test of all permutations:

@Test
public void testAllOrders() {
    for (Object[] sample: permute(1, 2, 3)) {
        for (Object index: sample) {
            switch (((Integer) index).intValue()) {
                case 1: test1(); break; 
                case 2: test2(); break; 
                case 3: test3(); break; 
            }
        }
    }
}

Here, permute() is a simple function which iterates all possible permuations into a Collection of array.

How to calculate UILabel width based on text length?

In swift

 yourLabel.intrinsicContentSize().width 

List Highest Correlation Pairs from a Large Correlation Matrix in Pandas?

I liked Addison Klinke's post the most, as being the simplest, but used Wojciech Moszczynsk’s suggestion for filtering and charting, but extended the filter to avoid absolute values, so given a large correlation matrix, filter it, chart it, and then flatten it:

Created, Filtered and Charted

dfCorr = df.corr()
filteredDf = dfCorr[((dfCorr >= .5) | (dfCorr <= -.5)) & (dfCorr !=1.000)]
plt.figure(figsize=(30,10))
sn.heatmap(filteredDf, annot=True, cmap="Reds")
plt.show()

filtered heat map

Function

In the end, I created a small function to create the correlation matrix, filter it, and then flatten it. As an idea, it could easily be extended, e.g., asymmetric upper and lower bounds, etc.

def corrFilter(x: pd.DataFrame, bound: float):
    xCorr = x.corr()
    xFiltered = xCorr[((xCorr >= bound) | (xCorr <= -bound)) & (xCorr !=1.000)]
    xFlattened = xFiltered.unstack().sort_values().drop_duplicates()
    return xFlattened

corrFilter(df, .7)

enter image description here

Save file/open file dialog box, using Swing & Netbeans GUI editor

I have created a sample UI which shows the save and open file dialog. Click on save button to open save dialog and click on open button to open file dialog.

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;

public class FileChooserEx {
    public static void main(String[] args) {
        Runnable r = new Runnable() {

            @Override
            public void run() {
                new FileChooserEx().createUI();
            }
        };

        EventQueue.invokeLater(r);
    }

    private void createUI() {
        JFrame frame = new JFrame();
        frame.setLayout(new BorderLayout());

        JButton saveBtn = new JButton("Save");
        JButton openBtn = new JButton("Open");

        saveBtn.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {
                JFileChooser saveFile = new JFileChooser();
                saveFile.showSaveDialog(null);
            }
        });

        openBtn.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {
                JFileChooser openFile = new JFileChooser();
                openFile.showOpenDialog(null);
            }
        });

        frame.add(new JLabel("File Chooser"), BorderLayout.NORTH);
        frame.add(saveBtn, BorderLayout.CENTER);
        frame.add(openBtn, BorderLayout.SOUTH);
        frame.setTitle("File Chooser");
        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
}

Plugin org.apache.maven.plugins:maven-clean-plugin:2.5 or one of its dependencies could not be resolved

I faced the same problem but it resolved with some changes in setting.xml(.*\apache-maven-3.3.3\apache-maven-3.3.3\conf).

  <proxies>
  <proxy>
    <id>proxy</id>
    <active>true</active>
    <protocol>http</protocol>
    <host>HOSTNAME</host>
    <port>PORT</port>
  </proxy>
</proxies>

Just check the hostname and port from the IE setting -> connections -> LAN Setting -> Proxy server

Hope this will resolve your problem also :)

React Router v4 - How to get current route?

In react router 4 the current route is in - this.props.location.pathname. Just get this.props and verify. If you still do not see location.pathname then you should use the decorator withRouter.

This might look something like this:

import {withRouter} from 'react-router-dom';

const SomeComponent = withRouter(props => <MyComponent {...props}/>);

class MyComponent extends React.Component {
  SomeMethod () {
    const {pathname} = this.props.location;
  }
}

Deleting an object in java?

Yea, java is Garbage collected, it will delete the memory for you.

How do I copy the contents of a String to the clipboard in C#?

WPF: System.Windows.Clipboard (PresentationCore.dll)

Winforms: System.Windows.Forms.Clipboard

Both have a static SetText method.

How to run a JAR file

Java

class Hello{
   public static void main(String [] args){
    System.out.println("Hello Shahid");
   }
}

manifest.mf

Manifest-version: 1.0
Main-Class: Hello

On command Line:

$ jar cfm HelloMss.jar  manifest.mf Hello.class 
$ java -jar HelloMss.jar

Output:

Hello Shahid

Could not autowire field in spring. why?

When you get this error some annotation is missing. I was missing @service annotation on service. When I added that annotation it worked fine for me.

How to check if a directory containing a file exist?

To check if a folder exists or not, you can simply use the exists() method:

// Create a File object representing the folder 'A/B'
def folder = new File( 'A/B' )

// If it doesn't exist
if( !folder.exists() ) {
  // Create all folders up-to and including B
  folder.mkdirs()
}

// Then, write to file.txt inside B
new File( folder, 'file.txt' ).withWriterAppend { w ->
  w << "Some text\n"
}

dyld: Library not loaded ... Reason: Image not found

I got this error when I tried to install ruby 2.3.1 using rvm. It first told me to run brew update, which I did, and then when I tried running rvm install ruby-2.3.1, I received the error in this SO question.

The fix was to first run brew upgrade, apparently according to this superuser.com question you need to do both brew update && brew upgrade. Once that was done, I could finally install ruby 2.3.1.

C# string replace

var str = "Text\",\"Text\",\"Text";
var newstr = str.Replace("\",\"", ";");

Event listener for when element becomes visible?

Going forward, the new HTML Intersection Observer API is the thing you're looking for. It allows you to configure a callback that is called whenever one element, called the target, intersects either the device viewport or a specified element. It's available in latest versions of Chrome, Firefox and Edge. See https://developer.mozilla.org/en-US/docs/Web/API/Intersection_Observer_API for more info.

Simple code example for observing display:none switching:

// Start observing visbility of element. On change, the
//   the callback is called with Boolean visibility as
//   argument:

function respondToVisibility(element, callback) {
  var options = {
    root: document.documentElement,
  };

  var observer = new IntersectionObserver((entries, observer) => {
    entries.forEach(entry => {
      callback(entry.intersectionRatio > 0);
    });
  }, options);

  observer.observe(element);
}

In action: https://jsfiddle.net/elmarj/u35tez5n/5/

Difference between the Apache HTTP Server and Apache Tomcat?

Apache Tomcat is used to deploy your Java Servlets and JSPs. So in your Java project you can build your WAR (short for Web ARchive) file, and just drop it in the deploy directory in Tomcat.

So basically Apache is an HTTP Server, serving HTTP. Tomcat is a Servlet and JSP Server serving Java technologies.

Tomcat includes Catalina, which is a servlet container. A servlet, at the end, is a Java class. JSP files (which are similar to PHP, and older ASP files) are generated into Java code (HttpServlet), which is then compiled to .class files by the server and executed by the Java virtual machine.

What is the fastest way to transpose a matrix in C++?

Some details about transposing 4x4 square float (I will discuss 32-bit integer later) matrices with x86 hardware. It's helpful to start here in order to transpose larger square matrices such as 8x8 or 16x16.

_MM_TRANSPOSE4_PS(r0, r1, r2, r3) is implemented differently by different compilers. GCC and ICC (I have not checked Clang) use unpcklps, unpckhps, unpcklpd, unpckhpd whereas MSVC uses only shufps. We can actually combine these two approaches together like this.

t0 = _mm_unpacklo_ps(r0, r1);
t1 = _mm_unpackhi_ps(r0, r1);
t2 = _mm_unpacklo_ps(r2, r3);
t3 = _mm_unpackhi_ps(r2, r3);

r0 = _mm_shuffle_ps(t0,t2, 0x44);
r1 = _mm_shuffle_ps(t0,t2, 0xEE);
r2 = _mm_shuffle_ps(t1,t3, 0x44);
r3 = _mm_shuffle_ps(t1,t3, 0xEE);

One interesting observation is that two shuffles can be converted to one shuffle and two blends (SSE4.1) like this.

t0 = _mm_unpacklo_ps(r0, r1);
t1 = _mm_unpackhi_ps(r0, r1);
t2 = _mm_unpacklo_ps(r2, r3);
t3 = _mm_unpackhi_ps(r2, r3);

v  = _mm_shuffle_ps(t0,t2, 0x4E);
r0 = _mm_blend_ps(t0,v, 0xC);
r1 = _mm_blend_ps(t2,v, 0x3);
v  = _mm_shuffle_ps(t1,t3, 0x4E);
r2 = _mm_blend_ps(t1,v, 0xC);
r3 = _mm_blend_ps(t3,v, 0x3);

This effectively converted 4 shuffles into 2 shuffles and 4 blends. This uses 2 more instructions than the implementation of GCC, ICC, and MSVC. The advantage is that it reduces port pressure which may have a benefit in some circumstances. Currently all the shuffles and unpacks can go only to one particular port whereas the blends can go to either of two different ports.

I tried using 8 shuffles like MSVC and converting that into 4 shuffles + 8 blends but it did not work. I still had to use 4 unpacks.

I used this same technique for a 8x8 float transpose (see towards the end of that answer). https://stackoverflow.com/a/25627536/2542702. In that answer I still had to use 8 unpacks but I manged to convert the 8 shuffles into 4 shuffles and 8 blends.

For 32-bit integers there is nothing like shufps (except for 128-bit shuffles with AVX512) so it can only be implemented with unpacks which I don't think can be convert to blends (efficiently). With AVX512 vshufi32x4 acts effectively like shufps except for 128-bit lanes of 4 integers instead of 32-bit floats so this same technique might be possibly with vshufi32x4 in some cases. With Knights Landing shuffles are four times slower (throughput) than blends.

How to force a line break on a Javascript concatenated string?

You need to use \n inside quotes.

document.getElementById("address_box").value = (title + "\n" + address + "\n" + address2 + "\n" + address3 + "\n" + address4)

\n is called a EOL or line-break, \n is a common EOL marker and is commonly refereed to as LF or line-feed, it is a special ASCII character

Loop through files in a directory using PowerShell

Give this a try:

Get-ChildItem "C:\Users\gerhardl\Documents\My Received Files" -Filter *.log | 
Foreach-Object {
    $content = Get-Content $_.FullName

    #filter and save content to the original file
    $content | Where-Object {$_ -match 'step[49]'} | Set-Content $_.FullName

    #filter and save content to a new file 
    $content | Where-Object {$_ -match 'step[49]'} | Set-Content ($_.BaseName + '_out.log')
}

How to create a bash script to check the SSH connection?

ssh -q -o "BatchMode=yes" -i /home/sicmapp/.ssh/id_rsa <ID>@<Servername>.<domain> "echo 2>&1" && echo $host SSH_OK || echo $host SSH_NOK

How to get the background color of an HTML element?

Simple solution

myDivObj = document.getElementById("myDivID")
let myDivObjBgColor = window.getComputedStyle(myDivObj).backgroundColor;

Now the background color is stored in the new variable.

https://jsfiddle.net/7q1dpeo9/1/

How to simulate a touch event in Android?

When using Monkey Script I noticed that DispatchPress(KEYCODE_BACK) is doing nothing which really suck. In many cases this is due to the fact that the Activity doesn't consume the Key event. The solution to this problem is to use a mix of monkey script and adb shell input command in a sequence.

1 Using monkey script gave some great timing control. Wait a certain amount of second for the activity and is a blocking adb call.
2 Finally sending adb shell input keyevent 4 will end the running APK.

EG

adb shell monkey -p com.my.application -v -v -v -f /sdcard/monkey_script.txt 1
adb shell input keyevent 4

Ruby: How to get the first character of a string

Any of these methods will work:

name = 'Smith'
puts name.[0..0] # => S
puts name.[0] # => S
puts name.[0,1] # => S
puts name.[0].chr # => S

REST API 404: Bad URI, or Missing Resource?

The Uniform Resource Identifier is a unique pointer to the resource. A poorly form URI doesn't point to the resource and therefore performing a GET on it will not return a resource. 404 means The server has not found anything matching the Request-URI. If you put in the wrong URI or bad URI that is your problem and the reason you didn't get to a resource whether a HTML page or IMG.

How to get parameters from a URL string?

To get parameters from URL string, I used following function.

var getUrlParameter = function getUrlParameter(sParam) {
    var sPageURL = decodeURIComponent(window.location.search.substring(1)),
        sURLVariables = sPageURL.split('&'),
        sParameterName,
        i;

    for (i = 0; i < sURLVariables.length; i++) {
        sParameterName = sURLVariables[i].split('=');

        if (sParameterName[0] === sParam) {
            return sParameterName[1] === undefined ? true : sParameterName[1];
        }
    }
};
var email = getUrlParameter('email');

If there are many URL strings, then you can use loop to get parameter 'email' from all those URL strings and store them in array.

Trying to make bootstrap modal wider

Always have handy the un-minified CSS for bootstrap so you can see what styles they have on their components, then create a CSS file AFTER it, if you don't use LESS and over-write their mixins or whatever

This is the default modal css for 768px and up:

@media (min-width: 768px) {
  .modal-dialog {
    width: 600px;
    margin: 30px auto;
  }
  ...
}

They have a class modal-lg for larger widths

@media (min-width: 992px) {
  .modal-lg {
    width: 900px;
  }
}

If you need something twice the 600px size, and something fluid, do something like this in your CSS after the Bootstrap css and assign that class to the modal-dialog.

@media (min-width: 768px) {
  .modal-xl {
    width: 90%;
   max-width:1200px;
  }
}

HTML

<div class="modal-dialog modal-xl">

Demo: http://jsbin.com/yefas/1

Minimum 6 characters regex expression

Something along the lines of this?

<asp:TextBox id="txtUsername" runat="server" />

<asp:RegularExpressionValidator
    id="RegularExpressionValidator1"
    runat="server"
    ErrorMessage="Field not valid!"
    ControlToValidate="txtUsername"
    ValidationExpression="[0-9a-zA-Z]{6,}" />

How to convert a const char * to std::string

std::string str(c_str, strnlen(c_str, max_length));

At Christian Rau's request:

strnlen is specified in POSIX.1-2008 and available in GNU's glibc and the Microsoft run-time library. It is not yet found in some other systems; you may fall back to Gnulib's substitute.

What is a good Hash Function?

This is an example of a good one and also an example of why you would never want to write one. It is a Fowler / Noll / Vo (FNV) Hash which is equal parts computer science genius and pure voodoo:

unsigned fnv_hash_1a_32 ( void *key, int len ) {
    unsigned char *p = key;
    unsigned h = 0x811c9dc5;
    int i;

    for ( i = 0; i < len; i++ )
      h = ( h ^ p[i] ) * 0x01000193;

   return h;
}

unsigned long long fnv_hash_1a_64 ( void *key, int len ) {
    unsigned char *p = key;
    unsigned long long h = 0xcbf29ce484222325ULL;
    int i;

    for ( i = 0; i < len; i++ )
      h = ( h ^ p[i] ) * 0x100000001b3ULL;

   return h;
}

Edit:

  • Landon Curt Noll recommends on his site the FVN-1A algorithm over the original FVN-1 algorithm: The improved algorithm better disperses the last byte in the hash. I adjusted the algorithm accordingly.

Testing Private method using mockito

Not possible through mockito. From their wiki

Why Mockito doesn't mock private methods?

Firstly, we are not dogmatic about mocking private methods. We just don't care about private methods because from the standpoint of testing private methods don't exist. Here are a couple of reasons Mockito doesn't mock private methods:

It requires hacking of classloaders that is never bullet proof and it changes the api (you must use custom test runner, annotate the class, etc.).

It is very easy to work around - just change the visibility of method from private to package-protected (or protected).

It requires me to spend time implementing & maintaining it. And it does not make sense given point #2 and a fact that it is already implemented in different tool (powermock).

Finally... Mocking private methods is a hint that there is something wrong with OO understanding. In OO you want objects (or roles) to collaborate, not methods. Forget about pascal & procedural code. Think in objects.

How to test if a string contains one of the substrings in a list, in pandas?

Here is a one line lambda that also works:

df["TrueFalse"] = df['col1'].apply(lambda x: 1 if any(i in x for i in searchfor) else 0)

Input:

searchfor = ['og', 'at']

df = pd.DataFrame([('cat', 1000.0), ('hat', 2000000.0), ('dog', 1000.0), ('fog', 330000.0),('pet', 330000.0)], columns=['col1', 'col2'])

   col1  col2
0   cat 1000.0
1   hat 2000000.0
2   dog 1000.0
3   fog 330000.0
4   pet 330000.0

Apply Lambda:

df["TrueFalse"] = df['col1'].apply(lambda x: 1 if any(i in x for i in searchfor) else 0)

Output:

    col1    col2        TrueFalse
0   cat     1000.0      1
1   hat     2000000.0   1
2   dog     1000.0      1
3   fog     330000.0    1
4   pet     330000.0    0

html5 <input type="file" accept="image/*" capture="camera"> display as image rather than "choose file" button

You can trigger a file input element by sending it a Javascript click event, e.g.

<input type="file" ... id="file-input">

$("#file-input").click();

You could put this in a click event handler for the image, for instance, then hide the file input with CSS. It'll still work even if it's invisible.

Once you've got that part working, you can set a change event handler on the input element to see when the user puts a file into it. This event handler can create a temporary "blob" URL for the image by using window.URL.createObjectURL, e.g.:

var file = document.getElementById("file-input").files[0];
var blob_url = window.URL.createObjectURL(file);

That URL can be set as the src for an image on the page. (It only works on that page, though. Don't try to save it anywhere.)

Note that not all browsers currently support camera capture. (In fact, most desktop browsers don't.) Make sure your interface still makes sense if the user gets asked to pick a file.

How to get current screen width in CSS?

this can be achieved with the css calc() operator

@media screen and (min-width: 480px) {
    body {
        background-color: lightgreen;
        zoom:calc(100% / 480);
    }
}

SimpleXML - I/O warning : failed to load external entity

$url = 'http://legis.senado.leg.br/dadosabertos/materia/tramitando';
$xml = file_get_contents("xml->{$url}");
$xml = simplexml_load_file($url);

How to make div appear in front of another?

Use the CSS z-index property. Elements with a greater z-index value are positioned in front of elements with smaller z-index values.

Note that for this to work, you also need to set a position style (position:absolute, position:relative, or position:fixed) on both/all of the elements you want to order.

Notepad++ Regular expression find and delete a line

Using the "Replace all" functionality, you can delete a line directly by ending your pattern with:

  • If your file have linux (LF) line ending : $\n?
  • If your file have windows (CRLF) line ending : $(\r\n)?

For instance, in your case :

.*#RedirectMatch Permanent.*$\n?

Spring: How to inject a value to static field?

First of all, public static non-final fields are evil. Spring does not allow injecting to such fields for a reason.

Your workaround is valid, you don't even need getter/setter, private field is enough. On the other hand try this:

@Value("${my.name}")
public void setPrivateName(String privateName) {
    Sample.name = privateName;
}  

(works with @Autowired/@Resource). But to give you some constructive advice: Create a second class with private field and getter instead of public static field.

Is it possible to decrypt SHA1

SHA1 is a one way hash. So you can not really revert it.

That's why applications use it to store the hash of the password and not the password itself.

Like every hash function SHA-1 maps a large input set (the keys) to a smaller target set (the hash values). Thus collisions can occur. This means that two values of the input set map to the same hash value.

Obviously the collision probability increases when the target set is getting smaller. But vice versa this also means that the collision probability decreases when the target set is getting larger and SHA-1's target set is 160 bit.

Jeff Preshing, wrote a very good blog about Hash Collision Probabilities that can help you to decide which hash algorithm to use. Thanks Jeff.

In his blog he shows a table that tells us the probability of collisions for a given input set.

Hash Collision Probabilities Table

As you can see the probability of a 32-bit hash is 1 in 2 if you have 77163 input values.

A simple java program will show us what his table shows:

public class Main {

    public static void main(String[] args) {
        char[] inputValue = new char[10];

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

        int collisionCount = 0;

        for (int i = 0; i < 77163; i++) {
            String asString = nextValue(inputValue);
            int hashCode = asString.hashCode();
            String collisionString = hashValues.put(hashCode, asString);
            if (collisionString != null) {
                collisionCount++;
                System.out.println("Collision: " + asString + " <-> " + collisionString);
            }
        }

        System.out.println("Collision count: " + collisionCount);
    }

    private static String nextValue(char[] inputValue) {
        nextValue(inputValue, 0);

        int endIndex = 0;
        for (int i = 0; i < inputValue.length; i++) {
            if (inputValue[i] == 0) {
                endIndex = i;
                break;
            }
        }

        return new String(inputValue, 0, endIndex);
    }

    private static void nextValue(char[] inputValue, int index) {
        boolean increaseNextIndex = inputValue[index] == 'z';

        if (inputValue[index] == 0 || increaseNextIndex) {
            inputValue[index] = 'A';
        } else {
            inputValue[index] += 1;
        }

        if (increaseNextIndex) {
            nextValue(inputValue, index + 1);
        }

    }

}

My output end with:

Collision: RvV <-> SWV
Collision: SvV <-> TWV
Collision: TvV <-> UWV
Collision: UvV <-> VWV
Collision: VvV <-> WWV
Collision: WvV <-> XWV
Collision count: 35135

It produced 35135 collsions and that's the nearly the half of 77163. And if I ran the program with 30084 input values the collision count is 13606. This is not exactly 1 in 10, but it is only a probability and the example program is not perfect, because it only uses the ascii chars between A and z.

Let's take the last reported collision and check

System.out.println("VvV".hashCode());
System.out.println("WWV".hashCode());

My output is

86390
86390

Conclusion:

If you have a SHA-1 value and you want to get the input value back you can try a brute force attack. This means that you have to generate all possible input values, hash them and compare them with the SHA-1 you have. But that will consume a lot of time and computing power. Some people created so called rainbow tables for some input sets. But these do only exist for some small input sets.

And remember that many input values map to a single target hash value. So even if you would know all mappings (which is impossible, because the input set is unbounded) you still can't say which input value it was.

Whitespaces in java

For a non-regular expression approach, you can check Character.isWhitespace for each character.

boolean containsWhitespace(String s) {
    for (int i = 0; i < s.length(); ++i) {
        if (Character.isWhitespace(s.charAt(i)) {
            return true;
        }
    }
    return false;
}

Which are the white spaces in Java?

The documentation specifies what Java considers to be whitespace:

public static boolean isWhitespace(char ch)

Determines if the specified character is white space according to Java. A character is a Java whitespace character if and only if it satisfies one of the following criteria:

  • It is a Unicode space character (SPACE_SEPARATOR, LINE_SEPARATOR, or PARAGRAPH_SEPARATOR) but is not also a non-breaking space ('\u00A0', '\u2007', '\u202F').
  • It is '\u0009', HORIZONTAL TABULATION.
  • It is '\u000A', LINE FEED.
  • It is '\u000B', VERTICAL TABULATION.
  • It is '\u000C', FORM FEED.
  • It is '\u000D', CARRIAGE RETURN.
  • It is '\u001C', FILE SEPARATOR.
  • It is '\u001D', GROUP SEPARATOR.
  • It is '\u001E', RECORD SEPARATOR.
  • It is '\u001F', UNIT SEPARATOR.

Server returned HTTP response code: 401 for URL: https

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

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

Authenticator.setDefault(new Authenticator() {

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

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

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

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

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

What should be the sizeof(int) on a 64-bit machine?

Doesn't have to be; "64-bit machine" can mean many things, but typically means that the CPU has registers that big. The sizeof a type is determined by the compiler, which doesn't have to have anything to do with the actual hardware (though it typically does); in fact, different compilers on the same machine can have different values for these.

What does template <unsigned int N> mean?

A template class is like a macro, only a whole lot less evil.

Think of a template as a macro. The parameters to the template get substituted into a class (or function) definition, when you define a class (or function) using a template.

The difference is that the parameters have "types" and values passed are checked during compilation, like parameters to functions. The types valid are your regular C++ types, like int and char. When you instantiate a template class, you pass a value of the type you specified, and in a new copy of the template class definition this value gets substituted in wherever the parameter name was in the original definition. Just like a macro.

You can also use the "class" or "typename" types for parameters (they're really the same). With a parameter of one of these types, you may pass a type name instead of a value. Just like before, everywhere the parameter name was in the template class definition, as soon as you create a new instance, becomes whatever type you pass. This is the most common use for a template class; Everybody that knows anything about C++ templates knows how to do this.

Consider this template class example code:

#include <cstdio>
template <int I>
class foo
{
  void print()
  {
    printf("%i", I);
  }
};

int main()
{
  foo<26> f;
  f.print();
  return 0;
}

It's functionally the same as this macro-using code:

#include <cstdio>
#define MAKE_A_FOO(I) class foo_##I \
{ \
  void print() \
  { \
    printf("%i", I); \
  } \
};

MAKE_A_FOO(26)

int main()
{
  foo_26 f;
  f.print();
  return 0;
}

Of course, the template version is a billion times safer and more flexible.

Extract code country from phone number [libphonenumber]

Use a try catch block like below:

try { 

const phoneNumber = this.phoneUtil.parseAndKeepRawInput(value, this.countryCode);

}catch(e){}

DateTime's representation in milliseconds?

There are ToUnixTime() and ToUnixTimeMs() methods in DateTimeExtensions class

DateTime.UtcNow.ToUnixTimeMs()

How to get input field value using PHP

function get_input_tags($html)
{
    $post_data = array();

    // a new dom object
    $dom = new DomDocument; 

    //load the html into the object
    $dom->loadHTML($html); 
    //discard white space
    $dom->preserveWhiteSpace = false; 

    //all input tags as a list
    $input_tags = $dom->getElementsByTagName('input'); 

    //get all rows from the table
    for ($i = 0; $i < $input_tags->length; $i++) 
    {
        if( is_object($input_tags->item($i)) )
        {
            $name = $value = '';
            $name_o = $input_tags->item($i)->attributes->getNamedItem('name');
            if(is_object($name_o))
            {
                $name = $name_o->value;

                $value_o = $input_tags->item($i)->attributes->getNamedItem('value');
                if(is_object($value_o))
                {
                    $value = $input_tags->item($i)->attributes->getNamedItem('value')->value;
                }

                $post_data[$name] = $value;
            }
        }
    }

    return $post_data; 
}

error_reporting(~E_WARNING);
$html = file_get_contents("https://accounts.google.com/ServiceLoginAuth");

print_r(get_input_tags($html));

How to align an image dead center with bootstrap

You could change the CSS of the previous solution as below:

.container, .row { text-align: center; }

This should center all the elements in the parent div as well.

Does C have a "foreach" loop construct?

C doesn't have a foreach, but macros are frequently used to emulate that:

#define for_each_item(item, list) \
    for(T * item = list->head; item != NULL; item = item->next)

And can be used like

for_each_item(i, processes) {
    i->wakeup();
}

Iteration over an array is also possible:

#define foreach(item, array) \
    for(int keep = 1, \
            count = 0,\
            size = sizeof (array) / sizeof *(array); \
        keep && count != size; \
        keep = !keep, count++) \
      for(item = (array) + count; keep; keep = !keep)

And can be used like

int values[] = { 1, 2, 3 };
foreach(int *v, values) {
    printf("value: %d\n", *v);
}

Edit: In case you are also interested in C++ solutions, C++ has a native for-each syntax called "range based for"

How using try catch for exception handling is best practice

My exception-handling strategy is:

  • To catch all unhandled exceptions by hooking to the Application.ThreadException event, then decide:

    • For a UI application: to pop it to the user with an apology message (WinForms)
    • For a Service or a Console application: log it to a file (service or console)

Then I always enclose every piece of code that is run externally in try/catch :

  • All events fired by the WinForms infrastructure (Load, Click, SelectedChanged...)
  • All events fired by third party components

Then I enclose in 'try/catch'

  • All the operations that I know might not work all the time (IO operations, calculations with a potential zero division...). In such a case, I throw a new ApplicationException("custom message", innerException) to keep track of what really happened

Additionally, I try my best to sort exceptions correctly. There are exceptions which:

  • need to be shown to the user immediately

  • require some extra processing to put things together when they happen to avoid cascading problems (ie: put .EndUpdate in the finally section during a TreeView fill)

  • the user does not care, but it is important to know what happened. So I always log them:

  • In the event log

  • or in a .log file on the disk

It is a good practice to design some static methods to handle exceptions in the application top level error handlers.

I also force myself to try to:

  • Remember ALL exceptions are bubbled up to the top level. It is not necessary to put exception handlers everywhere.
  • Reusable or deep called functions does not need to display or log exceptions : they are either bubbled up automatically or rethrown with some custom messages in my exception handlers.

So finally:

Bad:

// DON'T DO THIS; ITS BAD
try
{
    ...
}
catch 
{
   // only air...
}

Useless:

// DON'T DO THIS; IT'S USELESS
try
{
    ...
}
catch(Exception ex)
{
    throw ex;
}

Having a try finally without a catch is perfectly valid:

try
{
    listView1.BeginUpdate();

    // If an exception occurs in the following code, then the finally will be executed
    // and the exception will be thrown
    ...
}
finally
{
    // I WANT THIS CODE TO RUN EVENTUALLY REGARDLESS AN EXCEPTION OCCURRED OR NOT
    listView1.EndUpdate();
}

What I do at the top level:

// i.e When the user clicks on a button
try
{
    ...
}
catch(Exception ex)
{
    ex.Log(); // Log exception

    -- OR --
    
    ex.Log().Display(); // Log exception, then show it to the user with apologies...
}

What I do in some called functions:

// Calculation module
try
{
    ...
}
catch(Exception ex)
{
    // Add useful information to the exception
    throw new ApplicationException("Something wrong happened in the calculation module:", ex);
}

// IO module
try
{
    ...
}
catch(Exception ex)
{
    throw new ApplicationException(string.Format("I cannot write the file {0} to {1}", fileName, directoryName), ex);
}

There is a lot to do with exception handling (Custom Exceptions) but those rules that I try to keep in mind are enough for the simple applications I do.

Here is an example of extensions methods to handle caught exceptions a comfortable way. They are implemented in a way they can be chained together, and it is very easy to add your own caught exception processing.

// Usage:

try
{
    // boom
}
catch(Exception ex)
{
    // Only log exception
    ex.Log();

    -- OR --

    // Only display exception
    ex.Display();

    -- OR --

    // Log, then display exception
    ex.Log().Display();

    -- OR --

    // Add some user-friendly message to an exception
    new ApplicationException("Unable to calculate !", ex).Log().Display();
}

// Extension methods

internal static Exception Log(this Exception ex)
{
    File.AppendAllText("CaughtExceptions" + DateTime.Now.ToString("yyyy-MM-dd") + ".log", DateTime.Now.ToString("HH:mm:ss") + ": " + ex.Message + "\n" + ex.ToString() + "\n");
    return ex;
}

internal static Exception Display(this Exception ex, string msg = null, MessageBoxImage img = MessageBoxImage.Error)
{
    MessageBox.Show(msg ?? ex.Message, "", MessageBoxButton.OK, img);
    return ex;
}

How to indent a few lines in Markdown markup?

Okay, with a little HTML in your R code, I did the following code to generate pure text in R Markdown. The <h3 style="text-indent: 15em;"> indents the text 15 spaces. For the original question, change the 15 to 6.

## Option: Du Pont Ratio Concept - (ROE Decomposition)
### (Closed Quotes/Total Premium) = (Closed Quotes/Quotes Issued) X <br>
<h3 style="text-indent: 15em;">
 (Quotes Issued/Renewal Premium) X <br></h3>
<h3 style="text-indent: 15em;">
 (Renewal Premium/Total Premium)</h3>

So the resulting code gives my desired output format. I am using tabs for the Markdown document and was looking to line up the () text which worked.

r output

Double Iteration in List Comprehension

This flatten_nlevel function calls recursively the nested list1 to covert to one level. Try this out

def flatten_nlevel(list1, flat_list):
    for sublist in list1:
        if isinstance(sublist, type(list)):        
            flatten_nlevel(sublist, flat_list)
        else:
            flat_list.append(sublist)

list1 = [1,[1,[2,3,[4,6]],4],5]

items = []
flatten_nlevel(list1,items)
print(items)

output:

[1, 1, 2, 3, 4, 6, 4, 5]

JavaScript: Collision detection

bcm's answer, which has 0 votes at this time, is actually a great, under-appreciated answer. It uses good old Pythagoras to detect when objects are closer than their combined bounding circles. Simple collision detection often uses rectangular collision detection, which is fine if your sprites tend to be, well, rectangular. If they are circular (or otherwise less than rectangular), such as a ball, an asteroid, or any other shape where the extreme corners are usually transparent, you may find this efficient routine to be the most accurate.

But for clarity, here is a more fully realized version of the code:

function doCollide(x1, y1, w1, x2, y2, w2) {
    var xd = x1 - x2;
    var yd = y1 - y2;
    var wt = w2 + w1;
    return (xd * xd + yd * yd <= wt * wt);
}

Where the parameters to pass in are the x,y and width values of two different sprite objects.

Default value for field in Django model

Set editable to False and default to your default value.

http://docs.djangoproject.com/en/stable/ref/models/fields/#editable

b = models.CharField(max_length=7, default='0000000', editable=False)

Also, your id field is unnecessary. Django will add it automatically.

How to write a function that takes a positive integer N and returns a list of the first N natural numbers

Do I even need a for loop to create a list?

No, you can (and in general circumstances should) use the built-in function range():

>>> range(1,5)
[1, 2, 3, 4]

i.e.

def naturalNumbers(n):
    return range(1, n + 1)

Python 3's range() is slightly different in that it returns a range object and not a list, so if you're using 3.x wrap it all in list(): list(range(1, n + 1)).

Concatenate two NumPy arrays vertically

If the actual problem at hand is to concatenate two 1-D arrays vertically, and we are not fixated on using concatenate to perform this operation, I would suggest the use of np.column_stack:

In []: a = np.array([1,2,3])
In []: b = np.array([4,5,6])
In []: np.column_stack((a, b))
array([[1, 4],
       [2, 5],
       [3, 6]])

Passing Arrays to Function in C++

I just wanna add this, when you access the position of the array like

arg[n]

is the same as

*(arg + n) than means an offset of n starting from de arg address.

so arg[0] will be *arg

How can I debug my JavaScript code?

I use old good printf approach (an ancient technique which will work well in any time).

Look to magic %o:

console.log("this is %o, event is %o, host is %s", this, e, location.host);

%o dump clickable and deep-browsable, pretty-printed content of JS object. %s was shown just for a record.

And this:

console.log("%s", new Error().stack);

gives you Java-like stack trace to point of new Error() invocation (including path to file and line number!!).

Both %o and new Error().stack available in Chrome and Firefox.

With such powerful tools you make assumption whats going wrong in your JS, put debug output (don't forget wrap in if statement to reduce amount of data) and verify your assumption. Fix issue or make new assumption or put more debug output to bit problem.

Also for stack traces use:

console.trace();

as say Console

Happy hacking!

Combining Two Images with OpenCV

You can also use OpenCV's inbuilt functions cv2.hconcat and cv2.vconcat which like their names suggest are used to join images horizontally and vertically respectively.

import cv2

img1 = cv2.imread('opencv/lena.jpg')
img2 = cv2.imread('opencv/baboon.jpg')

v_img = cv2.vconcat([img1, img2])
h_img = cv2.hconcat([img1, img2])

cv2.imshow('Horizontal', h_img)
cv2.imshow('Vertical', v_img)
cv2.waitKey(0)
cv2.destroyAllWindows()

Horizontal Concatenation

Horizontal

Vertical Concatenation

Vertical

How to convert an iterator to a stream?

This is possible in Java 9.

Stream.generate(() -> null)
    .takeWhile(x -> iterator.hasNext())
    .map(n -> iterator.next())
    .forEach(System.out::println);

How to find files modified in last x minutes (find -mmin does not work as expected)

I can reproduce your problem if there are no files in the directory that were modified in the last hour. In that case, find . -mmin -60 returns nothing. The command find . -mmin -60 |xargs ls -l, however, returns every file in the directory which is consistent with what happens when ls -l is run without an argument.

To make sure that ls -l is only run when a file is found, try:

find . -mmin -60 -type f -exec ls -l {} +

Property 'json' does not exist on type 'Object'

For future visitors: In the new HttpClient (Angular 4.3+), the response object is JSON by default, so you don't need to do response.json().data anymore. Just use response directly.

Example (modified from the official documentation):

import { HttpClient } from '@angular/common/http';

@Component(...)
export class YourComponent implements OnInit {

  // Inject HttpClient into your component or service.
  constructor(private http: HttpClient) {}

  ngOnInit(): void {
    this.http.get('https://api.github.com/users')
        .subscribe(response => console.log(response));
  }
}

Don't forget to import it and include the module under imports in your project's app.module.ts:

...
import { HttpClientModule } from '@angular/common/http';

@NgModule({
  imports: [
    BrowserModule,
    // Include it under 'imports' in your application module after BrowserModule.
    HttpClientModule,
    ...
  ],
  ...

What's the difference between a Python module and a Python package?

A module is a single file (or files) that are imported under one import and used. e.g.

import my_module

A package is a collection of modules in directories that give a package hierarchy.

from my_package.timing.danger.internets import function_of_love

Documentation for modules

Introduction to packages

Set the table column width constant regardless of the amount of text in its cells?

If you don't want a fixed layout, specify a class for the column to be size appropriately.

CSS:

.special_column { width: 120px; }

HTML:

<td class="special_column">...</td>

NavigationBar bar, tint, and title text color in iOS 8

Setting text color of navigation bar title to white in Swift version 4.2:

navigationController?.navigationBar.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]

Should I add the Visual Studio .suo and .user files to source control?

On the MSDN website, it clearly states that

The solution user options (.suo) file contains per-user solution options. This file should not be checked in to source code control.

So I'd say it is pretty safe to ignore these files while checking in stuff to your source control.

Warning: mysqli_query() expects parameter 1 to be mysqli, resource given

You are mixing mysqli and mysql extensions, which will not work.

You need to use

$myConnection= mysqli_connect("$db_host","$db_username","$db_pass") or die ("could not connect to mysql"); 

mysqli_select_db($myConnection, "mrmagicadam") or die ("no database");   

mysqli has many improvements over the original mysql extension, so it is recommended that you use mysqli.

Installing SetupTools on 64-bit Windows

To allow Windows installers to find the installed Python directory in Windows 7, OR, change which Python installation to install an installer into, add the installed path into the InstallPath registry key's (Default) value:

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Python\PythonCore\2.X\InstallPath

Where "X" is the Python version (that is, 2.5, 2.6, or 2.7).

How to increase an array's length

Item[] newItemList = new  Item[itemList.length+1];
    //for loop to go thorough the list one by one
    for(int i=0; i< itemList.length;i++){
        //value is stored here in the new list from the old one
        newItemList[i]=itemList[i];
    }
    //all the values of the itemLists are stored in a bigger array named newItemList
    itemList=newItemList;

Can multiple different HTML elements have the same ID if they're different elements?

And for what it's worth, on Chrome 26.0.1410.65, Firefox 19.0.2, and Safari 6.0.3 at least, if you have multiple elements with the same ID, jquery selectors (at least) will return the first element with that ID.

e.g.

<div id="one">first text for one</div>
<div id="one">second text for one</div>

and

alert($('#one').size());

See http://jsfiddle.net/RuysX/ for a test.

inner join in linq to entities

Not 100% sure about the relationship between these two entities but here goes:

IList<Splitting> res = (from s in [data source]
                        where s.Customer.CompanyID == [companyID] &&
                              s.CustomerID == [customerID]
                        select s).ToList();

IList<Splitting> res = [data source].Splittings.Where(
                           x => x.Customer.CompanyID == [companyID] &&
                                x.CustomerID == [customerID]).ToList();

string sanitizer for filename

/ and .. in the user provided file name can be harmful. So you should get rid of these by something like:

$fname = str_replace('..', '', $fname);
$fname = str_replace('/',  '', $fname);

Creating and writing lines to a file

You'll need to deal with File System Object. See this OpenTextFile method sample.

Find maximum value of a column and return the corresponding row values using Pandas

Use the index attribute of DataFrame. Note that I don't type all the rows in the example.

In [14]: df = data.groupby(['Country','Place'])['Value'].max()

In [15]: df.index
Out[15]: 
MultiIndex
[Spain  Manchester, UK     London    , US     Mchigan   ,        NewYork   ]

In [16]: df.index[0]
Out[16]: ('Spain', 'Manchester')

In [17]: df.index[1]
Out[17]: ('UK', 'London')

You can also get the value by that index:

In [21]: for index in df.index:
    print index, df[index]
   ....:      
('Spain', 'Manchester') 512
('UK', 'London') 778
('US', 'Mchigan') 854
('US', 'NewYork') 562

Edit

Sorry for misunderstanding what you want, try followings:

In [52]: s=data.max()

In [53]: print '%s, %s, %s' % (s['Country'], s['Place'], s['Value'])
US, NewYork, 854

How to increment a datetime by one day?

Most Simplest solution

from datetime import timedelta, datetime
date = datetime(2003,8,1,12,4,5)
for i in range(5):
    date += timedelta(days=1)
    print(date)

Testing if a checkbox is checked with jQuery

I've came through a case recently where I've needed check value of checkbox when user clicked on button. The only proper way to do so is to use prop() attribute.

var ansValue = $("#ans").prop('checked') ? $("#ans").val() : 0;

this worked in my case maybe someone will need it.

When I've tried .attr(':checked') it returned checked but I wanted boolean value and .val() returned value of attribute value.

How to download Google Play Services in an Android emulator?

I got it working by

  • Installing the Google Play Services through the Android SDK Manager
  • Using a Galaxy Nexus Device (4.65", 720 x 1280: xhdpi)
  • Targeting the Android 4.2.2 Google API Level 17

Delegation: EventEmitter or Observable in Angular

You need to use the Navigation component in the template of ObservingComponent ( dont't forget to add a selector to Navigation component .. navigation-component for ex )

<navigation-component (navchange)='onNavGhange($event)'></navigation-component>

And implement onNavGhange() in ObservingComponent

onNavGhange(event) {
  console.log(event);
}

Last thing .. you don't need the events attribute in @Componennt

events : ['navchange'], 

Adding rows to dataset

To add rows to existing DataTable in Dataset:

DataRow drPartMtl = DSPartMtl.Tables[0].NewRow();
drPartMtl["Group"] = "Group";
drPartMtl["BOMPart"] = "BOMPart";
DSPartMtl.Tables[0].Rows.Add(drPartMtl);

How to read from a file or STDIN in Bash?

Perhaps the simplest solution is to redirect stdin with a merging redirect operator:

#!/bin/bash
less <&0

Stdin is file descriptor zero. The above sends the input piped to your bash script into less's stdin.

Read more about file descriptor redirection.

Bash integer comparison

This script works!

#/bin/bash
if [[ ( "$#" < 1 ) || ( !( "$1" == 1 ) && !( "$1" == 0 ) ) ]] ; then
    echo this script requires a 1 or 0 as first parameter.
else
    echo "first parameter is $1"
    xinput set-prop 12 "Device Enabled" $0
fi

But this also works, and in addition keeps the logic of the OP, since the question is about calculations. Here it is with only arithmetic expressions:

#/bin/bash
if (( $# )) && (( $1 == 0 || $1 == 1 )); then
    echo "first parameter is $1"
    xinput set-prop 12 "Device Enabled" $0
else
    echo this script requires a 1 or 0 as first parameter.
fi

The output is the same1:

$ ./tmp.sh 
this script requires a 1 or 0 as first parameter.

$ ./tmp.sh 0
first parameter is 0

$ ./tmp.sh 1
first parameter is 1

$ ./tmp.sh 2
this script requires a 1 or 0 as first parameter.

[1] the second fails if the first argument is a string

Getting the filenames of all files in a folder

Here's how to look in the documentation.

First, you're dealing with IO, so look in the java.io package.

There are two classes that look interesting: FileFilter and FileNameFilter. When I clicked on the first, it showed me that there was a a listFiles() method in the File class. And the documentation for that method says:

Returns an array of abstract pathnames denoting the files in the directory denoted by this abstract pathname.

Scrolling up in the File JavaDoc, I see the constructors. And that's really all I need to be able to create a File instance and call listFiles() on it. Scrolling still further, I can see some information about how files are named in different operating systems.

How can I install a CPAN module into a local directory?

I had a similar problem, where I couldn't even install local::lib

I created an installer that installed the module somewhere relative to the .pl files

The install goes like:

perl Makefile.PL PREFIX=./modulos
make
make install

Then, in the .pl file that requires the module, which is in ./

use lib qw(./modulos/share/perl/5.8.8/); # You may need to change this path
use module::name;

The rest of the files (makefile.pl, module.pm, etc) require no changes.

You can call the .pl file with just

perl file.pl

How to download Visual Studio Community Edition 2015 (not 2017)

The "official" way to get the vs2015 is to go to https://my.visualstudio.com/ ; join the " Visual Studio Dev Essentials" and then search the relevant file to download https://my.visualstudio.com/Downloads?q=Visual%20Studio%202015%20with%20Update%203

Can a shell script set environment variables of the calling shell?

It's "kind of" possible through using gdb and setenv(3), although I have a hard time recommending actually doing this. (Additionally, i.e. the most recent ubuntu won't actually let you do this without telling the kernel to be more permissive about ptrace, and the same may go for other distros as well).

$ cat setfoo
#! /bin/bash

gdb /proc/${PPID}/exe ${PPID} <<END >/dev/null
call setenv("foo", "bar", 0)
END
$ echo $foo

$ ./setfoo
$ echo $foo
bar

How do I convert Word files to PDF programmatically?

Seems to be some relevent info here:

Converting MS Word Documents to PDF in ASP.NET

Also, with Office 2007 having publish to PDF functionality, I guess you could use office automation to open the *.DOC file in Word 2007 and Save as PDF. I'm not too keen on office automation as it's slow and prone to hanging, but just throwing that out there...

Increment a Integer's int value?

Integer objects are immutable. You can't change the value of the integer held by the object itself, but you can just create a new Integer object to hold the result:

Integer start = new Integer(5);
Integer end = start + 5; // end == 10;

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

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

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

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

How do I run Python script using arguments in windows command line

I found this thread looking for information about dealing with parameters; this easy guide was so cool:

import argparse

parser = argparse.ArgumentParser(description='Script so useful.')
parser.add_argument("--opt1", type=int, default=1)
parser.add_argument("--opt2")

args = parser.parse_args()

opt1_value = args.opt1
opt2_value = args.opt2

run like:

python myScript.py --opt2 = 'hi'

Selecting and manipulating CSS pseudo-elements such as ::before and ::after using javascript (or jQuery)

one working but not very efficient way is to add a rule to the document with the new content and reference it with a class. depending on what is needed the class might need an unique id for each value in content.

$("<style type='text/css'>span.id-after:after{content:bar;}</style>").appendTo($("head"));
$('span').addClass('id-after');

Looping each row in datagridview

Best aproach for me was:

  private void grid_receptie_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
    {
        int X = 1;
        foreach(DataGridViewRow row in grid_receptie.Rows)
        {
            row.Cells["NR_CRT"].Value = X;
            X++;
        }
    }

phpMyAdmin mbstring error

just copy the php.ini file from C:\wamp\bin\apache\apache2.4.17\bin to C:\wamp\bin\apache\apache2.4.17\bin and then again restart apache server.. it will work fine.

Using JsonConvert.DeserializeObject to deserialize Json to a C# POCO class

That's not exactly what I had in mind. What do you do if you have a generic type to only be known at runtime?

public MyDTO toObject() {
  try {
    var methodInfo = MethodBase.GetCurrentMethod();
    if (methodInfo.DeclaringType != null) {
      var fullName = methodInfo.DeclaringType.FullName + "." + this.dtoName;
      Type type = Type.GetType(fullName);
      if (type != null) {
        var obj = JsonConvert.DeserializeObject(payload);
      //var obj = JsonConvert.DeserializeObject<type.MemberType.GetType()>(payload);  // <--- type ?????
          ...
      }
    }

    // Example for java..   Convert this to C#
    return JSONUtil.fromJSON(payload, Class.forName(dtoName, false, getClass().getClassLoader()));
  } catch (Exception ex) {
    throw new ReflectInsightException(MethodBase.GetCurrentMethod().Name, ex);
  }
}

'mat-form-field' is not a known element - Angular 5 & Material2

You're only exporting it in your NgModule, you need to import it too

@NgModule({
  imports: [
    MatButtonModule,
    MatFormFieldModule,
    MatInputModule,
    MatRippleModule,
 ]
  exports: [
    MatButtonModule,
    MatFormFieldModule,
    MatInputModule,
    MatRippleModule,
  ],
  declarations: [
    SearchComponent,
  ],
})export class MaterialModule {};

better yet

const modules = [
        MatButtonModule,
        MatFormFieldModule,
        MatInputModule,
        MatRippleModule
];

@NgModule({
  imports: [...modules],
  exports: [...modules]
  ,
})export class MaterialModule {};

update

You're declaring component (SearchComponent) depending on Angular Material before all Angular dependency are imported

Like BrowserAnimationsModule

Try moving it to MaterialModule, or before it

In Git, what is the difference between origin/master vs origin master?

I suggest merging develop and master with that command

git checkout master

git merge --commit --no-ff --no-edit develop

For more information, check https://git-scm.com/docs/git-merge

Convert String to SecureString

I'll throw this out there. Why?

You can't just change all your strings to secure strings and suddenly your application is "secure". Secure string is designed to keep the string encrypted for as long as possible, and only decrypted for a very short period of time, wiping the memory after an operation has been performed upon it.

I would hazard saying that you may have some design level issues to deal with before worrying about securing your application strings. Give us some more information on what your trying to do and we may be able to help better.

Can I mask an input text in a bat file?

1.Pure batch solution that (ab)uses XCOPY command and its /P /L switches found here (some improvements on this could be found here ):

:: Hidden.cmd
::Tom Lavedas, 02/05/2013, 02/20/2013
::Carlos, 02/22/2013
::https://groups.google.com/forum/#!topic/alt.msdos.batch.nt/f7mb_f99lYI


@Echo Off
:HInput
SetLocal EnableExtensions EnableDelayedExpansion
Set "FILE=%Temp%.\T"
Set "FILE=.\T"
Keys List >"%File%"
Set /P "=Hidden text ending with Ctrl-C?: " <Nul
Echo.
Set "HInput="
:HInput_
For /F "tokens=1* delims=?" %%A In (
 '"Xcopy /P /L "%FILE%" "%FILE%" 2>Nul"'
) Do (
  Set "Text=%%B"
  If Defined Text (
    Set "Char=!Text:~1,1!"
    Set "Intro=1"
    For /F delims^=^ eol^= %%Z in ("!Char!") Do Set "Intro=0"
    Rem If press Intro
    If 1 Equ !Intro! Goto :HInput#
    Set "HInput=!HInput!!Char!"
  )
)
Goto :HInput_
:HInput#
Echo(!HInput!
Goto :Eof 

1.2 Another way based on replace command

@Echo Off
SetLocal EnableExtensions EnableDelayedExpansion

Set /P "=Enter a Password:" < Nul
Call :PasswordInput
Echo(Your input was:!Line!

Goto :Eof

:PasswordInput
::Author: Carlos Montiers Aguilera
::Last updated: 20150401. Created: 20150401.
::Set in variable Line a input password
For /F skip^=1^ delims^=^ eol^= %%# in (
'"Echo(|Replace.exe "%~f0" . /U /W"') Do Set "CR=%%#"
For /F %%# In (
'"Prompt $H &For %%_ In (_) Do Rem"') Do Set "BS=%%#"
Set "Line="
:_PasswordInput_Kbd
Set "CHR=" & For /F skip^=1^ delims^=^ eol^= %%# in (
'Replace.exe "%~f0" . /U /W') Do Set "CHR=%%#"
If !CHR!==!CR! Echo(&Goto :Eof
If !CHR!==!BS! (If Defined Line (Set /P "=!BS! !BS!" <Nul
Set "Line=!Line:~0,-1!"
)
) Else (Set /P "=*" <Nul
If !CHR!==! (Set "Line=!Line!^!"
) Else Set "Line=!Line!!CHR!"
)
Goto :_PasswordInput_Kbd

2.Password submitter that uses a HTA pop-up . This is a hybrit .bat/jscript/mshta file and should be saved as a .bat:

<!-- :
:: PasswordSubmitter.bat
@echo off
for /f "tokens=* delims=" %%p in ('mshta.exe "%~f0"') do (
    set "pass=%%p"
)

echo your password is %pass%
exit /b
-->

<html>
<head><title>Password submitter</title></head>
<body>

    <script language='javascript' >
        window.resizeTo(300,150);
        function entperPressed(e){
                if (e.keyCode == 13) {
                    pipePass();
                }
        }
        function pipePass() {
            var pass=document.getElementById('pass').value;
            var fso= new ActiveXObject('Scripting.FileSystemObject').GetStandardStream(1);
            close(fso.Write(pass));

        }
    </script>

    <input type='password' name='pass' size='15' onkeypress="return entperPressed(event)" ></input>
    <hr>
    <button onclick='pipePass()'>Submit</button>

</body>
</html>

3.A self-compiled .net hybrid .Again should be saved as .bat .In difference with other solutions it will create/compile a small .exe file that will be called (if you wish you can delete it). Also requires installed .net framework but that's rather not a problem:

@if (@X)==(@Y) @end /* JScript comment
@echo off
setlocal enableDelayedExpansion

for /f "tokens=* delims=" %%v in ('dir /b /s /a:-d  /o:-n "%SystemRoot%\Microsoft.NET\Framework\*jsc.exe"') do (
   set "jsc=%%v"
)

if not exist "%~n0.exe" (
    "%jsc%" /nologo /out:"%~n0.exe" "%~dpsfnx0"
)

for /f "tokens=* delims=" %%p in ('"%~n0.exe"') do (
    set "pass=%%p"
)

echo your password is !pass!

endlocal & exit /b %errorlevel%

*/



import System;



var pwd = "";
var key;

Console.Error.Write("Enter password: ");

        do {
           key = Console.ReadKey(true);

           if ( (key.KeyChar.ToString().charCodeAt(0)) >= 20 && (key.KeyChar.ToString().charCodeAt(0) <= 126) ) {
              pwd=pwd+(key.KeyChar.ToString());
              Console.Error.Write("*");
           }

           if ( key.Key == ConsoleKey.Backspace && pwd.Length > 0 ) {
               pwd=pwd.Remove(pwd.Length-1);
               Console.Error.Write("\b \b");
           }


        } while (key.Key != ConsoleKey.Enter);
        Console.Error.WriteLine();
        Console.WriteLine(pwd);

Correct way to pass multiple values for same parameter name in GET request

there is no standard, but most frameworks support both, you can see for example for java spring that it accepts both here

@GetMapping("/api/foos")
@ResponseBody
public String getFoos(@RequestParam List<String> id) {
    return "IDs are " + id;
}

And Spring MVC will map a comma-delimited id parameter:

http://localhost:8080/api/foos?id=1,2,3
----
IDs are [1,2,3]

Or a list of separate id parameters:

http://localhost:8080/api/foos?id=1&id=2
----
IDs are [1,2]

How can I create a Java 8 LocalDate from a long Epoch time in Milliseconds?

If you have the milliseconds since the Epoch and want to convert them to a local date using the current local timezone, you can use

LocalDate date =
    Instant.ofEpochMilli(longValue).atZone(ZoneId.systemDefault()).toLocalDate();

but keep in mind that even the system’s default time zone may change, thus the same long value may produce different result in subsequent runs, even on the same machine.

Further, keep in mind that LocalDate, unlike java.util.Date, really represents a date, not a date and time.

Otherwise, you may use a LocalDateTime:

LocalDateTime date =
    LocalDateTime.ofInstant(Instant.ofEpochMilli(longValue), ZoneId.systemDefault());

CSS3 :unchecked pseudo-class

I think you are trying to over complicate things. A simple solution is to just style your checkbox by default with the unchecked styles and then add the checked state styles.

input[type="checkbox"] {
  // Unchecked Styles
}
input[type="checkbox"]:checked {
  // Checked Styles
}

I apologize for bringing up an old thread but felt like it could have used a better answer.

EDIT (3/3/2016):

W3C Specs state that :not(:checked) as their example for selecting the unchecked state. However, this is explicitly the unchecked state and will only apply those styles to the unchecked state. This is useful for adding styling that is only needed on the unchecked state and would need removed from the checked state if used on the input[type="checkbox"] selector. See example below for clarification.

input[type="checkbox"] {
  /* Base Styles aka unchecked */
  font-weight: 300; // Will be overwritten by :checked
  font-size: 16px; // Base styling
}
input[type="checkbox"]:not(:checked) {
  /* Explicit Unchecked Styles */
  border: 1px solid #FF0000; // Only apply border to unchecked state
}
input[type="checkbox"]:checked {
  /* Checked Styles */
  font-weight: 900; // Use a bold font when checked
}

Without using :not(:checked) in the example above the :checked selector would have needed to use a border: none; to achieve the same affect.

Use the input[type="checkbox"] for base styling to reduce duplication.

Use the input[type="checkbox"]:not(:checked) for explicit unchecked styles that you do not want to apply to the checked state.

Difference between INNER JOIN and LEFT SEMI JOIN

Trying to depict with venn diagrams for better understanding..

Left Semi join : A semi join returns values from the left side of the relation that has a match with the right. It is also referred to as a left semi join.

enter image description here

Note : There is another thing called left anti join : An anti join returns values from the left relation that has no match with the right. It is also referred to as a left anti join.

Inner join : It selects rows that have matching values in both relations.

enter image description here

How to import jquery using ES6 syntax?

Based on the solution of Édouard Lopez, but in two lines:

import jQuery from "jquery";
window.$ = window.jQuery = jQuery;

ERROR in ./node_modules/css-loader?

Laravel Mix 4 switches from node-sass to dart-sass (which may not compile as you would expect, OR you have to deal with the issues one by one)

OR

npm install node-sass


mix.sass('resources/sass/app.sass', 'public/css', {
implementation: require('node-sass')
});

https://laravel-mix.com/docs/4.0/upgrade

Simplest/cleanest way to implement a singleton in JavaScript

You can return the same instance in every new execution -

function Singleton() {
    // lazy 
    if (Singleton.prototype.myInstance == undefined) {
        Singleton.prototype.myInstance = { description: "I am the instance"};
    }
    return Singleton.prototype.myInstance;
}

a = new Singleton();
b = new Singleton();
console.log(a); // { description: "I am the instance"};
console.log(b); // { description: "I am the instance"};
console.log(a==b); // true

How do I navigate to another page when PHP script is done?

if ($done)
{
    header("Location: /url/to/the/other/page");
    exit;
}

Entity Framework. Delete all rows in table

This works Properly in EF 5:

YourEntityModel myEntities = new YourEntityModel();

var objCtx = ((IObjectContextAdapter)myEntities).ObjectContext;
objCtx.ExecuteStoreCommand("TRUNCATE TABLE [TableName]");

How to disable Google Chrome auto update?

We had a problem printing with v49something.

I blocked tools.google.com on localhost temporarily so that I could install previous version and prevent updating to the version that is breaking the label printing.

So, in /etc/hosts I added:

0.0.0.0 tools.google.com

Not a perfect solution, but was perfect for us.

Can't open file 'svn/repo/db/txn-current-lock': Permission denied

It's permission problem. It is not "classic" read/write permissions of apache user, but selinux one.

Apache cannot write to files labeled as httpd_sys_content_t they can be only read by apache.

You have 2 possibilities:

  1. label svn repository files as httpd_sys_content_rw_t:

    chcon -R -t httpd_sys_content_rw_t /path/to/your/svn/repo
    
  2. set selinux boolean httpd_unified --> on

    setsebool -P httpd_unified=1
    

I prefer 2nd possibility. You can play also with other selinux booleans connected with httpd:

getsebool -a | grep httpd

Decimal number regular expression, where digit after decimal is optional

^[+-]?(([1-9][0-9]*)?[0-9](\.[0-9]*)?|\.[0-9]+)$

should reflect what people usually think of as a well formed decimal number.

The digits before the decimal point can be either a single digit, in which case it can be from 0 to 9, or more than one digits, in which case it cannot start with a 0.

If there are any digits present before the decimal sign, then the decimal and the digits following it are optional. Otherwise, a decimal has to be present followed by at least one digit. Note that multiple trailing 0's are allowed after the decimal point.

grep -E '^[+-]?(([1-9][0-9]*)?[0-9](\.[0-9]*)?|\.[0-9]+)$'

correctly matches the following:

9
0
10
10.
0.
0.0
0.100
0.10
0.01
10.0
10.10
.0
.1
.00
.100
.001

as well as their signed equivalents, whereas it rejects the following:

.
00
01
00.0
01.3

and their signed equivalents, as well as the empty string.

LINQ: When to use SingleOrDefault vs. FirstOrDefault() with filtering criteria

Both are the element operators and they are used to select a single element from a sequence. But there is a minor difference between them. SingleOrDefault() operator would throw an exception if more than one elements are satisfied the condition where as FirstOrDefault() will not throw any exception for the same. Here is the example.

List<int> items = new List<int>() {9,10,9};
//Returns the first element of a sequence after satisfied the condition more than one elements
int result1 = items.Where(item => item == 9).FirstOrDefault();
//Throw the exception after satisfied the condition more than one elements
int result3 = items.Where(item => item == 9).SingleOrDefault();

Google Maps V3 - How to calculate the zoom level for a given bounds

Valerio is almost right with his solution, but there is some logical mistake.

you must firstly check wether angle2 is bigger than angle, before adding 360 at a negative.

otherwise you always have a bigger value than angle

So the correct solution is:

var west = calculateMin(data.longitudes);
var east = calculateMax(data.longitudes);
var angle = east - west;
var north = calculateMax(data.latitudes);
var south = calculateMin(data.latitudes);
var angle2 = north - south;
var zoomfactor;
var delta = 0;
var horizontal = false;

if(angle2 > angle) {
    angle = angle2;
    delta = 3;
}

if (angle < 0) {
    angle += 360;
}

zoomfactor = Math.floor(Math.log(960 * 360 / angle / GLOBE_WIDTH) / Math.LN2) - 2 - delta;

Delta is there, because i have a bigger width than height.

How to add files/folders to .gitignore in IntelliJ IDEA?

Intellij had .ignore plugin to support this. https://plugins.jetbrains.com/plugin/7495?pr=idea

After you install the plugin, you right click on the project and select new -> .ignore file -> .gitignore file (Git) enter image description here

Then, select the type of project you have to generate a template and click Generate. enter image description here

Using std::max_element on a vector<double>

As others have said, std::max_element() and std::min_element() return iterators, which need to be dereferenced to obtain the value.

The advantage of returning an iterator (rather than just the value) is that it allows you to determine the position of the (first) element in the container with the maximum (or minimum) value.

For example (using C++11 for brevity):

#include <vector>
#include <algorithm>
#include <iostream>

int main()
{
    std::vector<double> v {1.0, 2.0, 3.0, 4.0, 5.0, 1.0, 2.0, 3.0, 4.0, 5.0};

    auto biggest = std::max_element(std::begin(v), std::end(v));
    std::cout << "Max element is " << *biggest
        << " at position " << std::distance(std::begin(v), biggest) << std::endl;

    auto smallest = std::min_element(std::begin(v), std::end(v));
    std::cout << "min element is " << *smallest
        << " at position " << std::distance(std::begin(v), smallest) << std::endl;
}

This yields:

Max element is 5 at position 4
min element is 1 at position 0

Note:

Using std::minmax_element() as suggested in the comments above may be faster for large data sets, but may give slightly different results. The values for my example above would be the same, but the position of the "max" element would be 9 since...

If several elements are equivalent to the largest element, the iterator to the last such element is returned.

How do I parse a string to a float or int?

for number and char together :

string_for_int = "498 results should get"
string_for_float = "498.45645765 results should get"

first import re:

 import re

 #for get integer part:
 print(int(re.search(r'\d+', string_for_int).group())) #498

 #for get float part:
 print(float(re.search(r'\d+\.\d+', string_for_float).group())) #498.45645765

for easy model :

value1 = "10"
value2 = "10.2"
print(int(value1)) #10
print(float(value2)) #10.2

Set value of hidden field in a form using jQuery's ".val()" doesn't work

.val didnt work for me, because i'm grabbing the value attribute server side and the value wasn't always updated. so i used :

var counter = 0;
$('a.myClickableLink').click(function(event){
   event.preventDefault();
   counter++;

   ...
   $('#myInput').attr('value', counter);
}

Hope it helps someone.

Drop default constraint on a column in TSQL

I would suggest:

DECLARE @sqlStatement nvarchar(MAX),
        @tableName nvarchar(50) = 'TripEvent',
        @columnName nvarchar(50) = 'CreatedDate';

SELECT                  @sqlStatement = 'ALTER TABLE ' + @tableName + ' DROP CONSTRAINT ' + dc.name + ';'
        FROM            sys.default_constraints AS dc
            LEFT JOIN   sys.columns AS sc
                ON      (dc.parent_column_id = sc.column_id)
        WHERE           dc.parent_object_id = OBJECT_ID(@tableName)
        AND         type_desc = 'DEFAULT_CONSTRAINT'
        AND         sc.name = @columnName
PRINT'   ['+@tableName+']:'+@@SERVERNAME+'.'+DB_NAME()+'@'+CONVERT(VarChar, GETDATE(), 127)+';  '+@sqlStatement;
IF(LEN(@sqlStatement)>0)EXEC sp_executesql @sqlStatement

How to check if an object is a certain type

In VB.NET, you need to use the GetType method to retrieve the type of an instance of an object, and the GetType() operator to retrieve the type of another known type.

Once you have the two types, you can simply compare them using the Is operator.

So your code should actually be written like this:

Sub FillCategories(ByVal Obj As Object)
    Dim cmd As New SqlCommand("sp_Resources_Categories", Conn)
    cmd.CommandType = CommandType.StoredProcedure
    Obj.DataSource = cmd.ExecuteReader
    If Obj.GetType() Is GetType(System.Web.UI.WebControls.DropDownList) Then

    End If
    Obj.DataBind()
End Sub

You can also use the TypeOf operator instead of the GetType method. Note that this tests if your object is compatible with the given type, not that it is the same type. That would look like this:

If TypeOf Obj Is System.Web.UI.WebControls.DropDownList Then

End If

Totally trivial, irrelevant nitpick: Traditionally, the names of parameters are camelCased (which means they always start with a lower-case letter) when writing .NET code (either VB.NET or C#). This makes them easy to distinguish at a glance from classes, types, methods, etc.

iOS: how to perform a HTTP POST request?

I thought I would update this post a bit and say that alot of the iOS community has moved over to AFNetworking after ASIHTTPRequest was abandoned. I highly recommend it. It's a great wrapper around NSURLConnection and allows for asynchronous calls, and basically anything you might need.

Excel VBA Macro: User Defined Type Not Defined

Sub DeleteEmptyRows()  

    Worksheets("YourSheetName").Activate
    On Error Resume Next
    Columns("A").SpecialCells(xlCellTypeBlanks).EntireRow.Delete

End Sub

The following code will delete all rows on a sheet(YourSheetName) where the content of Column A is blank.

EDIT: User Defined Type Not Defined is caused by "oTable As Table" and "oRow As Row". Replace Table and Row with Object to resolve the error and make it compile.

What is 'Context' on Android?

Boss Assistant Analogy

Let's have a small analogy before diving deep in the technicality of Context

Every Boss has an assistant or someone( errand boy) who does less important and more time-consuming things for him. For example, if they need a file or coffee then an assistant will be on run. Boss will not know what is going on in the background but the file or the task will be delivered

So Here
Boss - Android Application
Assistant - Context
File or cup of coffee - Resource

What official Android Developer site says about Context

Context is your access point for application-related resources

Let's see some of such resources or tasks

  • Launching an activity.

  • Getting an absolute path to the application-specific cache directory on the filesystem.

  • Determining whether the given permission is allowed for a particular process and user ID running in the system.

  • Checking whether you have been granted a particular permission.

And so on.
So if an Android application wants to start an activity, it goes straight to Context (Access Point), and the Context class gives him back the resources(Intent in this case).

Like any other class Context class has fields and methods.
You can explore more about Context in official documentation, it covers pretty much everything, available methods, fields, and even how to use fields with methods.

How to encode a string in JavaScript for displaying in HTML?

The only character that needs escaping is <. (> is meaningless outside of a tag).

Therefore, your "magic" code is:

safestring = unsafestring.replace(/</g,'&lt;');

C# adding a character in a string

Here is my solution, without overdoing it.

    private static string AppendAtPosition(string baseString, int position, string character)
    {
        var sb = new StringBuilder(baseString);
        for (int i = position; i < sb.Length; i += (position + character.Length))
            sb.Insert(i, character);
        return sb.ToString();
    }


    Console.WriteLine(AppendAtPosition("abcdefghijklmnopqrstuvwxyz", 5, "-"));

Script for rebuilding and reindexing the fragmented index?

I have found the following script is very good at maintaining indexes, you can have this scheduled to run nightly or whatever other timeframe you wish.

http://sqlfool.com/2011/06/index-defrag-script-v4-1/

Matching strings with wildcard

C# Console application sample

Command line Sample:
C:/> App_Exe -Opy PythonFile.py 1 2 3
Console output:
Argument list: -Opy PythonFile.py 1 2 3
Found python filename: PythonFile.py

using System;
using System.Text.RegularExpressions;           //Regex

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            string cmdLine = String.Join(" ", args);

            bool bFileExtFlag = false;
            int argIndex = 0;
            Regex regex;
            foreach (string s in args)
            {
                //Search for the 1st occurrence of the "*.py" pattern
                regex = new Regex(@"(?s:.*)\056py", RegexOptions.IgnoreCase);
                bFileExtFlag = regex.IsMatch(s);
                if (bFileExtFlag == true)
                    break;
                argIndex++;
            };

            Console.WriteLine("Argument list: " + cmdLine);
            if (bFileExtFlag == true)
                Console.WriteLine("Found python filename: " + args[argIndex]);
            else
                Console.WriteLine("Python file with extension <.py> not found!");
        }


    }
}

How can I use MS Visual Studio for Android Development?

Microsoft Visual Studio 2015 now has options for Android development: C++, Cordova, and C# with Xamarin. When choosing one of those Android development options, Visual Studio will also install the brand new Visual Studio Emulator for Android to use as a target for debugging your app. You can also download the emulator without needing to install Visual Studio. For more details see

Visuals Studio 2015 https://www.visualstudio.com/en-us/downloads/visual-studio-2015-downloads-vs

Visual Studio Emulator https://www.visualstudio.com/en-us/features/msft-android-emulator-vs.aspx

Video of features https://channel9.msdn.com/Events/Visual-Studio/Visual-Studio-2015-Final-Release-Event/Visual-Studio-Emulator-for-Android

Java Extension for Visuals Studio 2012, 2013. 2015 https://visualstudiogallery.msdn.microsoft.com/bc561769-36ff-4a40-9504-e266e8706f93

C: scanf to array

The %d conversion specifier will only convert one decimal integer. It doesn't know that you're passing an array, it can't modify its behavior based on that. The conversion specifier specifies the conversion.

There is no specifier for arrays, you have to do it explicitly. Here's an example with four conversions:

if(scanf("%d %d %d %d", &array[0], &array[1], &array[2], &array[3]) == 4)
  printf("got four numbers\n");

Note that this requires whitespace between the input numbers.

If the id is a single 11-digit number, it's best to treat as a string:

char id[12];

if(scanf("%11s", id) == 1)
{
  /* inspect the *character* in id[0], compare with '1' or '2' for instance. */
}

PHP list of specific files in a directory

You should use glob.

glob('*.xml')

More about using glob and advanced filtering:

http://domexception.blogspot.fi/2013/08/php-using-functional-programming-for.html

Automatic confirmation of deletion in powershell

Try using the -Force parameter on Remove-Item.

How to check for palindrome using Python logic

Here is an example that takes a user's input and checks if the input is a palindrome:

name = input("Write your word here:  ")
input("Press <enter> to check if the word is a palindrome.")
if str(name) == str(name)[::-1]:
    print("True")
else:
    print("False")

However, there is no need to even set up the if/else statement. You can directly print the result of the logical comparison, as shown here:

name = input("Write your word here:  ")
input("Press <enter> to check if the word is a palindrome.")
print(str(name) == str(name)[::-1])

How to delete directory content in Java?

Use FileUtils with FileUtils.deleteDirectory();

Java using scanner enter key pressed

This works using java.util.Scanner and will take multiple "enter" keystrokes:

    Scanner scanner = new Scanner(System.in);
    String readString = scanner.nextLine();
    while(readString!=null) {
        System.out.println(readString);

        if (readString.isEmpty()) {
            System.out.println("Read Enter Key.");
        }

        if (scanner.hasNextLine()) {
            readString = scanner.nextLine();
        } else {
            readString = null;
        }
    }

To break it down:

Scanner scanner = new Scanner(System.in);
String readString = scanner.nextLine();

These lines initialize a new Scanner that is reading from the standard input stream (the keyboard) and reads a single line from it.

    while(readString!=null) {
        System.out.println(readString);

While the scanner is still returning non-null data, print each line to the screen.

        if (readString.isEmpty()) {
            System.out.println("Read Enter Key.");
        }

If the "enter" (or return, or whatever) key is supplied by the input, the nextLine() method will return an empty string; by checking to see if the string is empty, we can determine whether that key was pressed. Here the text Read Enter Key is printed, but you could perform whatever action you want here.

        if (scanner.hasNextLine()) {
            readString = scanner.nextLine();
        } else {
            readString = null;
        }

Finally, after printing the content and/or doing something when the "enter" key is pressed, we check to see if the scanner has another line; for the standard input stream, this method will "block" until either the stream is closed, the execution of the program ends, or further input is supplied.

Can't bind to 'dataSource' since it isn't a known property of 'table'

Thanx to @Jota.Toledo, I got the solution for my table creation. Please find the working code below:

component.html

<mat-table #table [dataSource]="dataSource" matSort>
  <ng-container matColumnDef="{{column.id}}" *ngFor="let column of columnNames">
    <mat-header-cell *matHeaderCellDef mat-sort-header> {{column.value}}</mat-header-cell>
    <mat-cell *matCellDef="let element"> {{element[column.id]}}</mat-cell>
  </ng-container>

  <mat-header-row *matHeaderRowDef="displayedColumns"></mat-header-row>
  <mat-row *matRowDef="let row; columns: displayedColumns;"></mat-row>
</mat-table>

component.ts

import { Component, OnInit, ViewChild } from '@angular/core';
import { MatTableDataSource, MatSort } from '@angular/material';
import { DataSource } from '@angular/cdk/table';

@Component({
  selector: 'app-m',
  templateUrl: './m.component.html',
  styleUrls: ['./m.component.css'],
})
export class MComponent implements OnInit {

  dataSource;
  displayedColumns = [];
  @ViewChild(MatSort) sort: MatSort;

  /**
   * Pre-defined columns list for user table
   */
  columnNames = [{
    id: 'position',
    value: 'No.',

  }, {
    id: 'name',
    value: 'Name',
  },
    {
      id: 'weight',
      value: 'Weight',
    },
    {
      id: 'symbol',
      value: 'Symbol',
    }];

  ngOnInit() {
    this.displayedColumns = this.columnNames.map(x => x.id);
    this.createTable();
  }

  createTable() {
    let tableArr: Element[] = [{ position: 1, name: 'Hydrogen', weight: 1.0079, symbol: 'H' },
      { position: 2, name: 'Helium', weight: 4.0026, symbol: 'He' },
      { position: 3, name: 'Lithium', weight: 6.941, symbol: 'Li' },
      { position: 4, name: 'Beryllium', weight: 9.0122, symbol: 'Be' },
      { position: 5, name: 'Boron', weight: 10.811, symbol: 'B' },
      { position: 6, name: 'Carbon', weight: 12.0107, symbol: 'C' },
    ];
    this.dataSource = new MatTableDataSource(tableArr);
    this.dataSource.sort = this.sort;
  }
}

export interface Element {
  position: number,
  name: string,
  weight: number,
  symbol: string
}

app.module.ts

imports: [
  MatSortModule,
  MatTableModule,
],

C: What is the difference between ++i and i++?

Here is the example to understand the difference

int i=10;
printf("%d %d",i++,++i);

output: 10 12/11 11 (depending on the order of evaluation of arguments to the printf function, which varies across compilers and architectures)

Explanation: i++->i is printed, and then increments. (Prints 10, but i will become 11) ++i->i value increments and prints the value. (Prints 12, and the value of i also 12)

"document.getElementByClass is not a function"

Before jumping into any further error checking please first check whether its

document.getElementsByClassName() itself.

double check its getElements and not getElement

How to cast from List<Double> to double[] in Java?

You can use the ArrayUtils class from commons-lang to obtain a double[] from a Double[].

Double[] ds = frameList.toArray(new Double[frameList.size()]);
...
double[] d = ArrayUtils.toPrimitive(ds);

Python Progress Bar

This is my simple solution:

import time

def progress(_cur, _max):
    p = round(100*_cur/_max)
    b = f"Progress: {p}% - ["+"."*int(p/5)+" "*(20-int(p/5))+"]"
    print(b, end="\r")

# USAGE:
for i in range(0,101):
    time.sleep(0.1) 
    progress(i,100)

print("..."*5, end="\r")
print("Done")

Grouped bar plot in ggplot

First you need to get the counts for each category, i.e. how many Bads and Goods and so on are there for each group (Food, Music, People). This would be done like so:

raw <- read.csv("http://pastebin.com/raw.php?i=L8cEKcxS",sep=",")
raw[,2]<-factor(raw[,2],levels=c("Very Bad","Bad","Good","Very Good"),ordered=FALSE)
raw[,3]<-factor(raw[,3],levels=c("Very Bad","Bad","Good","Very Good"),ordered=FALSE)
raw[,4]<-factor(raw[,4],levels=c("Very Bad","Bad","Good","Very Good"),ordered=FALSE)

raw=raw[,c(2,3,4)] # getting rid of the "people" variable as I see no use for it

freq=table(col(raw), as.matrix(raw)) # get the counts of each factor level

Then you need to create a data frame out of it, melt it and plot it:

Names=c("Food","Music","People")     # create list of names
data=data.frame(cbind(freq),Names)   # combine them into a data frame
data=data[,c(5,3,1,2,4)]             # sort columns

# melt the data frame for plotting
data.m <- melt(data, id.vars='Names')

# plot everything
ggplot(data.m, aes(Names, value)) +   
  geom_bar(aes(fill = variable), position = "dodge", stat="identity")

Is this what you're after?

enter image description here

To clarify a little bit, in ggplot multiple grouping bar you had a data frame that looked like this:

> head(df)
  ID Type Annee X1PCE X2PCE X3PCE X4PCE X5PCE X6PCE
1  1    A  1980   450   338   154    36    13     9
2  2    A  2000   288   407   212    54    16    23
3  3    A  2020   196   434   246    68    19    36
4  4    B  1980   111   326   441    90    21    11
5  5    B  2000    63   298   443   133    42    21
6  6    B  2020    36   257   462   162    55    30

Since you have numerical values in columns 4-9, which would later be plotted on the y axis, this can be easily transformed with reshape and plotted.

For our current data set, we needed something similar, so we used freq=table(col(raw), as.matrix(raw)) to get this:

> data
   Names Very.Bad Bad Good Very.Good
1   Food        7   6    5         2
2  Music        5   5    7         3
3 People        6   3    7         4

Just imagine you have Very.Bad, Bad, Good and so on instead of X1PCE, X2PCE, X3PCE. See the similarity? But we needed to create such structure first. Hence the freq=table(col(raw), as.matrix(raw)).

Remove gutter space for a specific div only

The total width is calculated with the width of the elements plus the width of the margin space. If you want to remove the margin space, that's fine, but to avoid that gap you mentioned, you also need to increase the width of the columns.

In this case, you need to increase the width of a single column by its removed margin space, which would be 30px.

So let's say your columns width is 50PX normally with 30PX margin space. Remove the margin space and make the width 80PX.

How to get row number from selected rows in Oracle

I think using

select rownum st.Branch 
  from student st 
 where st.name like '%ram%'

is a simple way; you should add single quotes in the LIKE statement. If you use row_number(), you should add over (order by 'sort column' 'asc/desc'), for instance:

select st.branch, row_number() over (order by 'sort column' 'asc/desc')  
  from student st 
 where st.name like '%ram%'

How to replace � in a string

Character issues like this are difficult to diagnose because information is easily lost through misinterpretation of characters via application bugs, misconfiguration, cut'n'paste, etc.

As I (and apparently others) see it, you've pasted three characters:

codepoint   glyph   escaped    windows-1252    info
=======================================================================
U+00ef      ï       \u00ef     ef,             LATIN_1_SUPPLEMENT, LOWERCASE_LETTER
U+00bf      ¿       \u00bf     bf,             LATIN_1_SUPPLEMENT, OTHER_PUNCTUATION
U+00bd      ½       \u00bd     bd,             LATIN_1_SUPPLEMENT, OTHER_NUMBER

To identify the character, download and run the program from this page. Paste your character into the text field and select the glyph mode; paste the report into your question. It'll help people identify the problematic character.

Is it possible to wait until all javascript files are loaded before executing javascript code?

You can use

$(window).on('load', function() {
    // your code here
});

Which will wait until the page is loaded. $(document).ready() waits until the DOM is loaded.

In plain JS:

window.addEventListener('load', function() {
    // your code here
})

Input text dialog Android

I found it cleaner and more reusable to extend AlertDialog.Builder to create a custom dialog class. This is for a dialog that asks the user to input a phone number. A preset phone number can also be supplied by calling setNumber() before calling show().

InputSenderDialog.java

public class InputSenderDialog extends AlertDialog.Builder {

    public interface InputSenderDialogListener{
        public abstract void onOK(String number);
        public abstract void onCancel(String number);
    }

    private EditText mNumberEdit;

    public InputSenderDialog(Activity activity, final InputSenderDialogListener listener) {
        super( new ContextThemeWrapper(activity, R.style.AppTheme) );

        @SuppressLint("InflateParams") // It's OK to use NULL in an AlertDialog it seems...
        View dialogLayout = LayoutInflater.from(activity).inflate(R.layout.dialog_input_sender_number, null);
        setView(dialogLayout);

        mNumberEdit = dialogLayout.findViewById(R.id.numberEdit);

        setPositiveButton("OK", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int id) {
                if( listener != null )
                    listener.onOK(String.valueOf(mNumberEdit.getText()));

            }
        });

        setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int id) {
                if( listener != null )
                    listener.onCancel(String.valueOf(mNumberEdit.getText()));
            }
        });
    }

    public InputSenderDialog setNumber(String number){
        mNumberEdit.setText( number );
        return this;
    }

    @Override
    public AlertDialog show() {
        AlertDialog dialog = super.show();
        Window window = dialog.getWindow();
        if( window != null )
            window.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE);
        return dialog;
    }
}

dialog_input_sender_number.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:padding="10dp">

    <TextView
        android:id="@+id/title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        android:paddingBottom="20dp"
        android:text="Input phone number"
        android:textAppearance="@style/TextAppearance.AppCompat.Large" />

    <TextView
        android:id="@+id/numberLabel"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toBottomOf="@+id/title"
        app:layout_constraintLeft_toLeftOf="parent"
        android:text="Phone number" />

    <EditText
        android:id="@+id/numberEdit"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toBottomOf="@+id/numberLabel"
        app:layout_constraintLeft_toLeftOf="parent"
        android:inputType="phone" >
        <requestFocus />
    </EditText>

</android.support.constraint.ConstraintLayout>

Usage:

new InputSenderDialog(getActivity(), new InputSenderDialog.InputSenderDialogListener() {
    @Override
    public void onOK(final String number) {
        Log.d(TAG, "The user tapped OK, number is "+number);
    }

    @Override
    public void onCancel(String number) {
        Log.d(TAG, "The user tapped Cancel, number is "+number);
    }
}).setNumber(someNumberVariable).show();

Warning: A non-numeric value encountered

If non-numeric value encountered in your code try below one. The below code is converted to float.

$PlannedAmount = ''; // empty string ''

if(!is_numeric($PlannedAmount)) {
           $PlannedAmount = floatval($PlannedAmount);
 }

 echo $PlannedAmount; //output = 0

Tips for debugging .htaccess rewrite rules

I'll leave this here, maybe obvious detail, but got me banging my head for hours: be careful using %{REQUEST_URI} because what @Krist van Besien say in his answer is totally right, but not for the REQUEST_URI string, because the out put of this TestString starts with a /. So take care:

RewriteCond %{REQUEST_URI} ^/assets/$  
                            ^
                            | check this pesky fella right here if missing

python: creating list from string

I know this is old but here's a one liner list comprehension:

data = ['word1, 23, 12','word2, 10, 19','word3, 11, 15']

[[int(item) if item.isdigit() else item for item in items.split(', ')] for items in data]

or

[int(item) if item.isdigit() else item for items in data for item in items.split(', ')]

JQuery Calculate Day Difference in 2 date textboxes

This is a simple way of getting the DAYS between two dates

var nites = dateDiff(arriveDate,departDate,"D");

jQuery get selected option value (not the text, but the attribute 'value')

Try this:

$(document).ready(function(){
    var data= $('select').find('option:selected').val();
});

or

var data= $('select').find('option:selected').text();

How to use MD5 in javascript to transmit a password

if you're using php jquery, this might help:

   $.ajax({
        url:'phpmd5file.php',
        data:{'mypassword',mypassword},
        dataType:"json",
        method:"POST",
        success:function(mymd5password){
            alert(mymd5password);
        }
    });

on your phpmd5.php file:

echo json_encode($_POST["mypassword"]);

no jsplugins needed. just use ajax and let php md5() do the job.

In c++ what does a tilde "~" before a function name signify?

It's a destructor. The function is guaranteed to be called when the object goes out of scope.

Get size of a View in React Native

Basically if you want to set size and make it change then set it to state on layout like this:

import React, { Component } from 'react';
import { AppRegistry, StyleSheet, View } from 'react-native';

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: 'yellow',
  },
  View1: {
    flex: 2,
    margin: 10,
    backgroundColor: 'red',
    elevation: 1,
  },
  View2: {
    position: 'absolute',
    backgroundColor: 'orange',
    zIndex: 3,
    elevation: 3,
  },
  View3: {
    flex: 3,
    backgroundColor: 'green',
    elevation: 2,
  },
  Text: {
    fontSize: 25,
    margin: 20,
    color: 'white',
  },
});

class Example extends Component {

  constructor(props) {
    super(props);

    this.state = {
      view2LayoutProps: {
        left: 0,
        top: 0,
        width: 50,
        height: 50,
      }
    };
  }

  onLayout(event) {
    const {x, y, height, width} = event.nativeEvent.layout;
    const newHeight = this.state.view2LayoutProps.height + 1;
    const newLayout = {
        height: newHeight ,
        width: width,
        left: x,
        top: y,
      };

    this.setState({ view2LayoutProps: newLayout });
  }

  render() {
    return (
      <View style={styles.container}>
        <View style={styles.View1}>
          <Text>{this.state.view2LayoutProps.height}</Text>
        </View>
        <View onLayout={(event) => this.onLayout(event)} 
              style={[styles.View2, this.state.view2LayoutProps]} />
        <View style={styles.View3} />
      </View>
    );
  }

}


AppRegistry.registerComponent(Example);

You can create many more variation of how it should be modified, by using this in another component which has Another view as wrapper and create an onResponderRelease callback, which could pass the touch event location into the state, which could be then passed to child component as property, which could override onLayout updated state, by placing {[styles.View2, this.state.view2LayoutProps, this.props.touchEventTopLeft]} and so on.

How to enable CORS in flask

If you want to enable CORS for all routes, then just install flask_cors extension (pip3 install -U flask_cors) and wrap app like this: CORS(app).

That is enough to do it (I tested this with a POST request to upload an image, and it worked for me):

from flask import Flask
from flask_cors import CORS
app = Flask(__name__)
CORS(app) # This will enable CORS for all routes

Important note: if there is an error in your route, let us say you try to print a variable that does not exist, you will get a CORS error related message which, in fact, has nothing to do with CORS.

C++ delete vector, objects, free memory

You can call clear, and that will destroy all the objects, but that will not free the memory. Looping through the individual elements will not help either (what action would you even propose to take on the objects?) What you can do is this:

vector<tempObject>().swap(tempVector);

That will create an empty vector with no memory allocated and swap it with tempVector, effectively deallocating the memory.

C++11 also has the function shrink_to_fit, which you could call after the call to clear(), and it would theoretically shrink the capacity to fit the size (which is now 0). This is however, a non-binding request, and your implementation is free to ignore it.

Force overwrite of local file with what's in origin repo?

If you want to overwrite only one file:

git fetch
git checkout origin/master <filepath>

If you want to overwrite all changed files:

git fetch
git reset --hard origin/master

(This assumes that you're working on master locally and you want the changes on the origin's master - if you're on a branch, substitute that in instead.)

Why should we typedef a struct so often in C?

Using a typedef avoids having to write struct every time you declare a variable of that type:

struct elem
{
 int i;
 char k;
};
elem user; // compile error!
struct elem user; // this is correct

Recursion or Iteration?

I found another differences between those approaches. It looks simple and unimportant, but it has a very important role while you prepare for interviews and this subject arises, so look closely.

In short: 1) iterative post-order traversal is not easy - that makes DFT more complex 2) cycles check easier with recursion

Details:

In the recursive case, it is easy to create pre and post traversals:

Imagine a pretty standard question: "print all tasks that should be executed to execute the task 5, when tasks depend on other tasks"

Example:

    //key-task, value-list of tasks the key task depends on
    //"adjacency map":
    Map<Integer, List<Integer>> tasksMap = new HashMap<>();
    tasksMap.put(0, new ArrayList<>());
    tasksMap.put(1, new ArrayList<>());

    List<Integer> t2 = new ArrayList<>();
    t2.add(0);
    t2.add(1);
    tasksMap.put(2, t2);

    List<Integer> t3 = new ArrayList<>();
    t3.add(2);
    t3.add(10);
    tasksMap.put(3, t3);

    List<Integer> t4 = new ArrayList<>();
    t4.add(3);
    tasksMap.put(4, t4);

    List<Integer> t5 = new ArrayList<>();
    t5.add(3);
    tasksMap.put(5, t5);

    tasksMap.put(6, new ArrayList<>());
    tasksMap.put(7, new ArrayList<>());

    List<Integer> t8 = new ArrayList<>();
    t8.add(5);
    tasksMap.put(8, t8);

    List<Integer> t9 = new ArrayList<>();
    t9.add(4);
    tasksMap.put(9, t9);

    tasksMap.put(10, new ArrayList<>());

    //task to analyze:
    int task = 5;


    List<Integer> res11 = getTasksInOrderDftReqPostOrder(tasksMap, task);
    System.out.println(res11);**//note, no reverse required**

    List<Integer> res12 = getTasksInOrderDftReqPreOrder(tasksMap, task);
    Collections.reverse(res12);//note reverse!
    System.out.println(res12);

    private static List<Integer> getTasksInOrderDftReqPreOrder(Map<Integer, List<Integer>> tasksMap, int task) {
         List<Integer> result = new ArrayList<>();
         Set<Integer> visited = new HashSet<>();
         reqPreOrder(tasksMap,task,result, visited);
         return result;
    }

private static void reqPreOrder(Map<Integer, List<Integer>> tasksMap, int task, List<Integer> result, Set<Integer> visited) {

    if(!visited.contains(task)) {
        visited.add(task);
        result.add(task);//pre order!
        List<Integer> children = tasksMap.get(task);
        if (children != null && children.size() > 0) {
            for (Integer child : children) {
                reqPreOrder(tasksMap,child,result, visited);
            }
        }
    }
}

private static List<Integer> getTasksInOrderDftReqPostOrder(Map<Integer, List<Integer>> tasksMap, int task) {
    List<Integer> result = new ArrayList<>();
    Set<Integer> visited = new HashSet<>();
    reqPostOrder(tasksMap,task,result, visited);
    return result;
}

private static void reqPostOrder(Map<Integer, List<Integer>> tasksMap, int task, List<Integer> result, Set<Integer> visited) {
    if(!visited.contains(task)) {
        visited.add(task);
        List<Integer> children = tasksMap.get(task);
        if (children != null && children.size() > 0) {
            for (Integer child : children) {
                reqPostOrder(tasksMap,child,result, visited);
            }
        }
        result.add(task);//post order!
    }
}

Note that the recursive post-order-traversal does not require a subsequent reversal of the result. Children printed first and your task in the question printed last. Everything is fine. You can do a recursive pre-order-traversal (also shown above) and that one will require a reversal of the result list.

Not that simple with iterative approach! In iterative (one stack) approach you can only do a pre-ordering-traversal, so you obliged to reverse the result array at the end:

    List<Integer> res1 = getTasksInOrderDftStack(tasksMap, task);
    Collections.reverse(res1);//note reverse!
    System.out.println(res1);

    private static List<Integer> getTasksInOrderDftStack(Map<Integer, List<Integer>> tasksMap, int task) {
    List<Integer> result = new ArrayList<>();
    Set<Integer> visited = new HashSet<>();
    Stack<Integer> st = new Stack<>();


    st.add(task);
    visited.add(task);

    while(!st.isEmpty()){
        Integer node = st.pop();
        List<Integer> children = tasksMap.get(node);
        result.add(node);
        if(children!=null && children.size() > 0){
            for(Integer child:children){
                if(!visited.contains(child)){
                    st.add(child);
                    visited.add(child);
                }
            }
        }
        //If you put it here - it does not matter - it is anyway a pre-order
        //result.add(node);
    }
    return result;
}

Looks simple, no?

But it is a trap in some interviews.

It means the following: with the recursive approach, you can implement Depth First Traversal and then select what order you need pre or post(simply by changing the location of the "print", in our case of the "adding to the result list"). With the iterative (one stack) approach you can easily do only pre-order traversal and so in the situation when children need be printed first(pretty much all situations when you need start print from the bottom nodes, going upwards) - you are in the trouble. If you have that trouble you can reverse later, but it will be an addition to your algorithm. And if an interviewer is looking at his watch it may be a problem for you. There are complex ways to do an iterative post-order traversal, they exist, but they are not simple. Example:https://www.geeksforgeeks.org/iterative-postorder-traversal-using-stack/

Thus, the bottom line: I would use recursion during interviews, it is simpler to manage and to explain. You have an easy way to go from pre to post-order traversal in any urgent case. With iterative you are not that flexible.

I would use recursion and then tell: "Ok, but iterative can provide me more direct control on used memory, I can easily measure the stack size and disallow some dangerous overflow.."

Another plus of recursion - it is simpler to avoid / notice cycles in a graph.

Example (preudocode):

dft(n){
    mark(n)
    for(child: n.children){
        if(marked(child)) 
            explode - cycle found!!!
        dft(child)
    }
    unmark(n)
}

How to access a dictionary key value present inside a list?

Index the list then the dict.

print L[1]['d']

Inverse dictionary lookup in Python

Since this is still very relevant, the first Google hit and I just spend some time figuring this out, I'll post my (working in Python 3) solution:

testdict = {'one'   : '1',
            'two'   : '2',
            'three' : '3',
            'four'  : '4'
            }

value = '2'

[key for key in testdict.items() if key[1] == value][0][0]

Out[1]: 'two'

It will give you the first value that matches.

MySQL INNER JOIN Alias

You'll need to join twice:

SELECT home.*, away.*, g.network, g.date_start 
FROM game AS g
INNER JOIN team AS home
  ON home.importid = g.home
INNER JOIN team AS away
  ON away.importid = g.away
ORDER BY g.date_start DESC 
LIMIT 7

When should I use git pull --rebase?

I don't think there's ever a reason not to use pull --rebase -- I added code to Git specifically to allow my git pull command to always rebase against upstream commits.

When looking through history, it is just never interesting to know when the guy/gal working on the feature stopped to synchronise up. It might be useful for the guy/gal while he/she is doing it, but that's what reflog is for. It's just adding noise for everyone else.

How to convert date to string and to date again?

try this function

public static Date StringToDate(String strDate) throws ModuleException {
    Date dtReturn = null;
    SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-mm-dd");
    try {
        dtReturn = simpleDateFormat.parse(strDate);
    } catch (ParseException e) {
        e.printStackTrace();
    }
    return dtReturn;
}

Check if number is prime number

This is basically an implementation of a brilliant suggestion made by Eric Lippert somewhere above.

    public static bool isPrime(int number)
    {
        if (number == 1) return false;
        if (number == 2 || number == 3 || number == 5) return true;
        if (number % 2 == 0 || number % 3 == 0 || number % 5 == 0) return false;

        var boundary = (int)Math.Floor(Math.Sqrt(number));

        // You can do less work by observing that at this point, all primes 
        // other than 2 and 3 leave a remainder of either 1 or 5 when divided by 6. 
        // The other possible remainders have been taken care of.
        int i = 6; // start from 6, since others below have been handled.
        while (i <= boundary)
        {
            if (number % (i + 1) == 0 || number % (i + 5) == 0)
                return false;

            i += 6;
        }

        return true;
    }

Remove part of string after "."

You just need to escape the period:

a <- c("NM_020506.1","NM_020519.1","NM_001030297.2","NM_010281.2","NM_011419.3", "NM_053155.2")

gsub("\\..*","",a)
[1] "NM_020506"    "NM_020519"    "NM_001030297" "NM_010281"    "NM_011419"    "NM_053155" 

Bower: ENOGIT Git is not installed or not in the PATH

npm install from git bash did work for me. After rebooting PC.

How to show alert message in mvc 4 controller?

TempData["msg"] = "<script>alert('Change succesfully');</script>";
@Html.Raw(TempData["msg"])

Convert nested Python dict to object?

>>> def dict2obj(d):
        if isinstance(d, list):
            d = [dict2obj(x) for x in d]
        if not isinstance(d, dict):
            return d
        class C(object):
            pass
        o = C()
        for k in d:
            o.__dict__[k] = dict2obj(d[k])
        return o


>>> d = {'a': 1, 'b': {'c': 2}, 'd': ["hi", {'foo': "bar"}]}
>>> x = dict2obj(d)
>>> x.a
1
>>> x.b.c
2
>>> x.d[1].foo
'bar'

PHP - include a php file and also send query parameters

I have ran into this when doing ajax forms where I include multiple field sets. Taking for example an employment application. I start out with one professional reference set and I have a button that says "Add More". This does an ajax call with a $count parameter to include the input set again (name, contact, phone.. etc) This works fine on first page call as I do something like:

<?php 
include('references.php');`
?>

User presses a button that makes an ajax call ajax('references.php?count=1'); Then inside the references.php file I have something like:

<?php
$count = isset($_GET['count']) ? $_GET['count'] : 0;
?>

I also have other dynamic includes like this throughout the site that pass parameters. The problem happens when the user presses submit and there is a form error. So now to not duplicate code to include those extra field sets that where dynamically included, i created a function that will setup the include with the appropriate GET params.

<?php

function include_get_params($file) {
  $parts = explode('?', $file);
  if (isset($parts[1])) {
    parse_str($parts[1], $output);
    foreach ($output as $key => $value) {
      $_GET[$key] = $value;
    }
  }
  include($parts[0]);
}
?>

The function checks for query params, and automatically adds them to the $_GET variable. This has worked pretty good for my use cases.

Here is an example on the form page when called:

<?php
// We check for a total of 12
for ($i=0; $i<12; $i++) {
  if (isset($_POST['references_name_'.$i]) && !empty($_POST['references_name_'.$i])) {
   include_get_params(DIR .'references.php?count='. $i);
 } else {
   break;
 }
}
?>

Just another example of including GET params dynamically to accommodate certain use cases. Hope this helps. Please note this code isn't in its complete state but this should be enough to get anyone started pretty good for their use case.

In MVC, how do I return a string result?

As of 2020, using ContentResult is still the right approach as proposed above, but the usage is as follows:

return new System.Web.Mvc.ContentResult
{
    Content = "Hi there! ?",
    ContentType = "text/plain; charset=utf-8"
}

What is the difference between ports 465 and 587?

SMTP protocol: smtps (port 465) v. msa (port 587)

Ports 465 and 587 are intended for email client to email server communication - sending out email using SMTP protocol.

Port 465 is for smtps
SSL encryption is started automatically before any SMTP level communication.

Port 587 is for msa
It is almost like standard SMTP port. MSA should accept email after authentication (e.g. after SMTP AUTH). It helps to stop outgoing spam when netmasters of DUL ranges can block outgoing connections to SMTP port (port 25).
SSL encryption may be started by STARTTLS command at SMTP level if server supports it and your ISP does not filter server's EHLO reply (reported 2014).


Port 25 is used by MTA to MTA communication (mail server to mail server). It may be used for client to server communication but it is not currently the most recommended. Standard SMTP port accepts email from other mail servers to its "internal" mailboxes without authentication.

Scale image to fit a bounding box

html:

    <div class="container">
      <img class="flowerImg" src="flower.jpg">
    </div>

css:

.container{
  width: 100px;
  height: 100px;
}


.flowerImg{
  width: 100px;
  height: 100px;
  object-fit: cover;
  /*object-fit: contain;
  object-fit: scale-down;
  object-position: -10% 0;
  object-fit: none;
  object-fit: fill;*/
}

Show loading image while $.ajax is performed

Before your call either insert the loading image in a div/span somewhere and then on the success function remove that image. Alternatively you can set up a css class like loading that might look like this

.loading
{
    width: 16px;
    height: 16px;
    background:transparent url('loading.gif') no-repeat 0 0;
    font-size: 0px;
    display: inline-block;
}

And then assign this class to a span/div and clear it in the success function

How do I make UITableViewCell's ImageView a fixed size even when the image is smaller

Here's how i did it. This technique takes care of moving the text and detail text labels appropriately to the left:

@interface SizableImageCell : UITableViewCell {}
@end
@implementation SizableImageCell
- (void)layoutSubviews {
    [super layoutSubviews];

    float desiredWidth = 80;
    float w=self.imageView.frame.size.width;
    if (w>desiredWidth) {
        float widthSub = w - desiredWidth;
        self.imageView.frame = CGRectMake(self.imageView.frame.origin.x,self.imageView.frame.origin.y,desiredWidth,self.imageView.frame.size.height);
        self.textLabel.frame = CGRectMake(self.textLabel.frame.origin.x-widthSub,self.textLabel.frame.origin.y,self.textLabel.frame.size.width+widthSub,self.textLabel.frame.size.height);
        self.detailTextLabel.frame = CGRectMake(self.detailTextLabel.frame.origin.x-widthSub,self.detailTextLabel.frame.origin.y,self.detailTextLabel.frame.size.width+widthSub,self.detailTextLabel.frame.size.height);
        self.imageView.contentMode = UIViewContentModeScaleAspectFit;
    }
}
@end

...

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[SizableImageCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier] autorelease];
        cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
    }

    cell.textLabel.text = ...
    cell.detailTextLabel.text = ...
    cell.imageView.image = ...
    return cell;
}