Programs & Examples On #Qfiledialog

QFileDialog is a class from the Qt toolkit which provides a dialog allowing users to select files or directories.

Android emulator shows nothing except black screen and adb devices shows "device offline"

Make sure that you've installed the latest HAXM revision. I had the same blank screen problem with version 1.0.1 while 1.0.8 was already available. The installer can be downloaded via the SDK tools, to actually install the module you would have to execute

android-sdk-directory\extras\intel\Hardware_Accelerated_Execution_Manager\intelhaxm.exe

How to convert a normal Git repository to a bare one?

Oneliner for doing all of the above operations:

for i in `ls -A .`; do if [ $i != ".git" ]; then rm -rf $i; fi; done; mv .git/* .; rm -rf .git; git config --bool core.bare true

(don't blame me if something blows up and you didn't have backups :P)

Is there a way to iterate over a dictionary?

The block approach avoids running the lookup algorithm for every key:

[dict enumerateKeysAndObjectsUsingBlock:^(id key, id value, BOOL* stop) {
  NSLog(@"%@ => %@", key, value);
}];

Even though NSDictionary is implemented as a hashtable (which means that the cost of looking up an element is O(1)), lookups still slow down your iteration by a constant factor.

My measurements show that for a dictionary d of numbers ...

NSMutableDictionary* dict = [NSMutableDictionary dictionary];
for (int i = 0; i < 5000000; ++i) {
  NSNumber* value = @(i);
  dict[value.stringValue] = value;
}

... summing up the numbers with the block approach ...

__block int sum = 0;
[dict enumerateKeysAndObjectsUsingBlock:^(NSString* key, NSNumber* value, BOOL* stop) {
  sum += value.intValue;
}];

... rather than the loop approach ...

int sum = 0;
for (NSString* key in dict)
  sum += [dict[key] intValue];

... is about 40% faster.

EDIT: The new SDK (6.1+) appears to optimise loop iteration, so the loop approach is now about 20% faster than the block approach, at least for the simple case above.

Running powershell script within python script, how to make python print the powershell output while it is running

I don't have Python 2.7 installed, but in Python 3.3 calling Popen with stdout set to sys.stdout worked just fine. Not before I had escaped the backslashes in the path, though.

>>> import subprocess
>>> import sys
>>> p = subprocess.Popen(['powershell.exe', 'C:\\Temp\\test.ps1'], stdout=sys.stdout)
>>> Hello World
_

Multipart File upload Spring Boot

@RequestMapping(value="/add/image", method=RequestMethod.POST)
public ResponseEntity upload(@RequestParam("id") Long id, HttpServletResponse response, HttpServletRequest request)
{   
    try {
        MultipartHttpServletRequest multipartRequest=(MultipartHttpServletRequest)request;
        Iterator<String> it=multipartRequest.getFileNames();
        MultipartFile multipart=multipartRequest.getFile(it.next());
        String fileName=id+".png";
        String imageName = fileName;

        byte[] bytes=multipart.getBytes();
        BufferedOutputStream stream= new BufferedOutputStream(new FileOutputStream("src/main/resources/static/image/book/"+fileName));;

        stream.write(bytes);
        stream.close();
        return new ResponseEntity("upload success", HttpStatus.OK);

    } catch (Exception e) {
        e.printStackTrace();
        return new ResponseEntity("Upload fialed", HttpStatus.BAD_REQUEST);
    }   
}

How to return data from PHP to a jQuery ajax call

I figured it out. Need to use echo in PHP instead of return.

<?php 
  $output = some_function();
  echo $output;
?> 

And the jQ:

success: function(data) {
  doSomething(data);
}

split string only on first instance of specified character

Here's one RegExp that does the trick.

'good_luck_buddy' . split(/^.*?_/)[1] 

First it forces the match to start from the start with the '^'. Then it matches any number of characters which are not '_', in other words all characters before the first '_'.

The '?' means a minimal number of chars that make the whole pattern match are matched by the '.*?' because it is followed by '_', which is then included in the match as its last character.

Therefore this split() uses such a matching part as its 'splitter' and removes it from the results. So it removes everything up till and including the first '_' and gives you the rest as the 2nd element of the result. The first element is "" representing the part before the matched part. It is "" because the match starts from the beginning.

There are other RegExps that work as well like /_(.*)/ given by Chandu in a previous answer.

The /^.*?_/ has the benefit that you can understand what it does without having to know about the special role capturing groups play with replace().

How to easily get network path to the file you are working on?

In Win7 (and Vista I think), you can Shift+Right Click the file in question and select Copy as path to get the full network path. Note: if the shared drive is mapped to a letter, you will get that path instead (ie: X:\someguy\somefile.xls)

Scanner only reads first word instead of line

input.next() takes in the first whitsepace-delimited word of the input string. So by design it does what you've described. Try input.nextLine().

Java Read Large Text File With 70million line of text

enter image description hereI actually did a research in this topic for months in my free time and came up with a benchmark and here is a code to benchmark all the different ways to read a File line by line.The individual performance may vary based on the underlying system. I ran on a windows 10 Java 8 Intel i5 HP laptop:Here is the code.

import java.io.*;
import java.nio.channels.Channels;
import java.nio.channels.FileChannel;
import java.nio.file.Files;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.regex.Pattern;
import java.util.stream.Stream;

public class ReadComplexDelimitedFile {
    private static long total = 0;
    private static final Pattern FIELD_DELIMITER_PATTERN = Pattern.compile("\\^\\|\\^");

    @SuppressWarnings("unused")
    private void readFileUsingScanner() {

        String s;
        try (Scanner stdin = new Scanner(new File(this.getClass().getResource("input.txt").getPath()))) {
            while (stdin.hasNextLine()) {
                s = stdin.nextLine();
                String[] fields = FIELD_DELIMITER_PATTERN.split(s, 0);
                total = total + fields.length;
            }
        } catch (Exception e) {
            System.err.println("Error");
        }

    }

    //Winner
    private void readFileUsingCustomBufferedReader() {

        try (CustomBufferedReader stdin = new CustomBufferedReader(new FileReader(new File(this.getClass().getResource("input.txt").getPath())))) {
            String s;
            while ((s = stdin.readLine()) != null) {
                String[] fields = FIELD_DELIMITER_PATTERN.split(s, 0);
                total += fields.length;
            }
        } catch (Exception e) {
            System.err.println("Error");
        }

    }


    private void readFileUsingBufferedReader() {

        try (BufferedReader stdin = new BufferedReader(new FileReader(new File(this.getClass().getResource("input.txt").getPath())))) {
            String s;
            while ((s = stdin.readLine()) != null) {
                String[] fields = FIELD_DELIMITER_PATTERN.split(s, 0);
                total += fields.length;
            }
        } catch (Exception e) {
            System.err.println("Error");
        }
    }

    private void readFileUsingLineReader() {

        try (LineNumberReader stdin = new LineNumberReader(new FileReader(new File(this.getClass().getResource("input.txt").getPath())))) {
            String s;
            while ((s = stdin.readLine()) != null) {
                String[] fields = FIELD_DELIMITER_PATTERN.split(s, 0);
                total += fields.length;
            }
        } catch (Exception e) {
            System.err.println("Error");
        }
    }

    private void readFileUsingStreams() {

        try (Stream<String> stream = Files.lines((new File(this.getClass().getResource("input.txt").getPath())).toPath())) {
            total += stream.mapToInt(s -> FIELD_DELIMITER_PATTERN.split(s, 0).length).sum();
        } catch (IOException e1) {
            e1.printStackTrace();
        }
    }


    private void readFileUsingBufferedReaderFileChannel() {
        try (FileInputStream fis = new FileInputStream(this.getClass().getResource("input.txt").getPath())) {
            try (FileChannel inputChannel = fis.getChannel()) {
                try (CustomBufferedReader stdin = new CustomBufferedReader(Channels.newReader(inputChannel, "UTF-8"))) {
                    String s;
                    while ((s = stdin.readLine()) != null) {
                        String[] fields = FIELD_DELIMITER_PATTERN.split(s, 0);
                        total = total + fields.length;
                    }
                }
            } catch (Exception e) {
                System.err.println("Error");
            }
        } catch (Exception e) {
            System.err.println("Error");
        }

    }


    public static void main(String args[]) {
        //JVM wamrup
        for (int i = 0; i < 100000; i++) {
            total += i;
        }
        // We know scanner is slow-Still warming up
        ReadComplexDelimitedFile readComplexDelimitedFile = new ReadComplexDelimitedFile();
        List<Long> longList = new ArrayList<>(50);
        for (int i = 0; i < 50; i++) {
            total = 0;
            long startTime = System.nanoTime();
            //readComplexDelimitedFile.readFileUsingScanner();
            long stopTime = System.nanoTime();
            long timeDifference = stopTime - startTime;
            longList.add(timeDifference);

        }
        System.out.println("Time taken for readFileUsingScanner");
        longList.forEach(System.out::println);
        // Actual performance test starts here

        longList = new ArrayList<>(10);
        for (int i = 0; i < 10; i++) {
            total = 0;
            long startTime = System.nanoTime();
            readComplexDelimitedFile.readFileUsingBufferedReaderFileChannel();
            long stopTime = System.nanoTime();
            long timeDifference = stopTime - startTime;
            longList.add(timeDifference);

        }
        System.out.println("Time taken for readFileUsingBufferedReaderFileChannel");
        longList.forEach(System.out::println);
        longList.clear();
        for (int i = 0; i < 10; i++) {
            total = 0;
            long startTime = System.nanoTime();
            readComplexDelimitedFile.readFileUsingBufferedReader();
            long stopTime = System.nanoTime();
            long timeDifference = stopTime - startTime;
            longList.add(timeDifference);

        }
        System.out.println("Time taken for readFileUsingBufferedReader");
        longList.forEach(System.out::println);
        longList.clear();
        for (int i = 0; i < 10; i++) {
            total = 0;
            long startTime = System.nanoTime();
            readComplexDelimitedFile.readFileUsingStreams();
            long stopTime = System.nanoTime();
            long timeDifference = stopTime - startTime;
            longList.add(timeDifference);

        }
        System.out.println("Time taken for readFileUsingStreams");
        longList.forEach(System.out::println);
        longList.clear();
        for (int i = 0; i < 10; i++) {
            total = 0;
            long startTime = System.nanoTime();
            readComplexDelimitedFile.readFileUsingCustomBufferedReader();
            long stopTime = System.nanoTime();
            long timeDifference = stopTime - startTime;
            longList.add(timeDifference);

        }
        System.out.println("Time taken for readFileUsingCustomBufferedReader");
        longList.forEach(System.out::println);
        longList.clear();
        for (int i = 0; i < 10; i++) {
            total = 0;
            long startTime = System.nanoTime();
            readComplexDelimitedFile.readFileUsingLineReader();
            long stopTime = System.nanoTime();
            long timeDifference = stopTime - startTime;
            longList.add(timeDifference);

        }
        System.out.println("Time taken for readFileUsingLineReader");
        longList.forEach(System.out::println);

    }
}

I had to rewrite BufferedReader to avoid synchronized and a couple of boundary conditions that is not needed.(Atleast that's what I felt.It is not unit tested so use it at your own risk.)

import com.sun.istack.internal.NotNull;

import java.io.*;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;

/**
 * Reads text from a character-input stream, buffering characters so as to
 * provide for the efficient reading of characters, arrays, and lines.
 * <p>
 * <p> The buffer size may be specified, or the default size may be used.  The
 * default is large enough for most purposes.
 * <p>
 * <p> In general, each read request made of a Reader causes a corresponding
 * read request to be made of the underlying character or byte stream.  It is
 * therefore advisable to wrap a CustomBufferedReader around any Reader whose read()
 * operations may be costly, such as FileReaders and InputStreamReaders.  For
 * example,
 * <p>
 * <pre>
 * CustomBufferedReader in
 *   = new CustomBufferedReader(new FileReader("foo.in"));
 * </pre>
 * <p>
 * will buffer the input from the specified file.  Without buffering, each
 * invocation of read() or readLine() could cause bytes to be read from the
 * file, converted into characters, and then returned, which can be very
 * inefficient.
 * <p>
 * <p> Programs that use DataInputStreams for textual input can be localized by
 * replacing each DataInputStream with an appropriate CustomBufferedReader.
 *
 * @author Mark Reinhold
 * @see FileReader
 * @see InputStreamReader
 * @see java.nio.file.Files#newBufferedReader
 * @since JDK1.1
 */

public class CustomBufferedReader extends Reader {

    private final Reader in;

    private char cb[];
    private int nChars, nextChar;

    private static final int INVALIDATED = -2;
    private static final int UNMARKED = -1;
    private int markedChar = UNMARKED;
    private int readAheadLimit = 0; /* Valid only when markedChar > 0 */

    /**
     * If the next character is a line feed, skip it
     */
    private boolean skipLF = false;

    /**
     * The skipLF flag when the mark was set
     */
    private boolean markedSkipLF = false;

    private static int defaultCharBufferSize = 8192;
    private static int defaultExpectedLineLength = 80;
    private ReadWriteLock rwlock;


    /**
     * Creates a buffering character-input stream that uses an input buffer of
     * the specified size.
     *
     * @param in A Reader
     * @param sz Input-buffer size
     * @throws IllegalArgumentException If {@code sz <= 0}
     */
    public CustomBufferedReader(@NotNull final Reader in, int sz) {
        super(in);
        if (sz <= 0)
            throw new IllegalArgumentException("Buffer size <= 0");
        this.in = in;
        cb = new char[sz];
        nextChar = nChars = 0;
        rwlock = new ReentrantReadWriteLock();
    }

    /**
     * Creates a buffering character-input stream that uses a default-sized
     * input buffer.
     *
     * @param in A Reader
     */
    public CustomBufferedReader(@NotNull final Reader in) {
        this(in, defaultCharBufferSize);
    }


    /**
     * Fills the input buffer, taking the mark into account if it is valid.
     */
    private void fill() throws IOException {
        int dst;
        if (markedChar <= UNMARKED) {
            /* No mark */
            dst = 0;
        } else {
            /* Marked */
            int delta = nextChar - markedChar;
            if (delta >= readAheadLimit) {
                /* Gone past read-ahead limit: Invalidate mark */
                markedChar = INVALIDATED;
                readAheadLimit = 0;
                dst = 0;
            } else {
                if (readAheadLimit <= cb.length) {
                    /* Shuffle in the current buffer */
                    System.arraycopy(cb, markedChar, cb, 0, delta);
                    markedChar = 0;
                    dst = delta;
                } else {
                    /* Reallocate buffer to accommodate read-ahead limit */
                    char ncb[] = new char[readAheadLimit];
                    System.arraycopy(cb, markedChar, ncb, 0, delta);
                    cb = ncb;
                    markedChar = 0;
                    dst = delta;
                }
                nextChar = nChars = delta;
            }
        }

        int n;
        do {
            n = in.read(cb, dst, cb.length - dst);
        } while (n == 0);
        if (n > 0) {
            nChars = dst + n;
            nextChar = dst;
        }
    }

    /**
     * Reads a single character.
     *
     * @return The character read, as an integer in the range
     * 0 to 65535 (<tt>0x00-0xffff</tt>), or -1 if the
     * end of the stream has been reached
     * @throws IOException If an I/O error occurs
     */
    public char readChar() throws IOException {
        for (; ; ) {
            if (nextChar >= nChars) {
                fill();
                if (nextChar >= nChars)
                    return (char) -1;
            }
            return cb[nextChar++];
        }
    }

    /**
     * Reads characters into a portion of an array, reading from the underlying
     * stream if necessary.
     */
    private int read1(char[] cbuf, int off, int len) throws IOException {
        if (nextChar >= nChars) {
            /* If the requested length is at least as large as the buffer, and
               if there is no mark/reset activity, and if line feeds are not
               being skipped, do not bother to copy the characters into the
               local buffer.  In this way buffered streams will cascade
               harmlessly. */
            if (len >= cb.length && markedChar <= UNMARKED && !skipLF) {
                return in.read(cbuf, off, len);
            }
            fill();
        }
        if (nextChar >= nChars) return -1;
        int n = Math.min(len, nChars - nextChar);
        System.arraycopy(cb, nextChar, cbuf, off, n);
        nextChar += n;
        return n;
    }

    /**
     * Reads characters into a portion of an array.
     * <p>
     * <p> This method implements the general contract of the corresponding
     * <code>{@link Reader#read(char[], int, int) read}</code> method of the
     * <code>{@link Reader}</code> class.  As an additional convenience, it
     * attempts to read as many characters as possible by repeatedly invoking
     * the <code>read</code> method of the underlying stream.  This iterated
     * <code>read</code> continues until one of the following conditions becomes
     * true: <ul>
     * <p>
     * <li> The specified number of characters have been read,
     * <p>
     * <li> The <code>read</code> method of the underlying stream returns
     * <code>-1</code>, indicating end-of-file, or
     * <p>
     * <li> The <code>ready</code> method of the underlying stream
     * returns <code>false</code>, indicating that further input requests
     * would block.
     * <p>
     * </ul> If the first <code>read</code> on the underlying stream returns
     * <code>-1</code> to indicate end-of-file then this method returns
     * <code>-1</code>.  Otherwise this method returns the number of characters
     * actually read.
     * <p>
     * <p> Subclasses of this class are encouraged, but not required, to
     * attempt to read as many characters as possible in the same fashion.
     * <p>
     * <p> Ordinarily this method takes characters from this stream's character
     * buffer, filling it from the underlying stream as necessary.  If,
     * however, the buffer is empty, the mark is not valid, and the requested
     * length is at least as large as the buffer, then this method will read
     * characters directly from the underlying stream into the given array.
     * Thus redundant <code>CustomBufferedReader</code>s will not copy data
     * unnecessarily.
     *
     * @param cbuf Destination buffer
     * @param off  Offset at which to start storing characters
     * @param len  Maximum number of characters to read
     * @return The number of characters read, or -1 if the end of the
     * stream has been reached
     * @throws IOException If an I/O error occurs
     */
    public int read(char cbuf[], int off, int len) throws IOException {
        int n = read1(cbuf, off, len);
        if (n <= 0) return n;
        while ((n < len) && in.ready()) {
            int n1 = read1(cbuf, off + n, len - n);
            if (n1 <= 0) break;
            n += n1;
        }
        return n;
    }

    /**
     * Reads a line of text.  A line is considered to be terminated by any one
     * of a line feed ('\n'), a carriage return ('\r'), or a carriage return
     * followed immediately by a linefeed.
     *
     * @param ignoreLF If true, the next '\n' will be skipped
     * @return A String containing the contents of the line, not including
     * any line-termination characters, or null if the end of the
     * stream has been reached
     * @throws IOException If an I/O error occurs
     * @see java.io.LineNumberReader#readLine()
     */
    String readLine(boolean ignoreLF) throws IOException {
        StringBuilder s = null;
        int startChar;



        bufferLoop:
        for (; ; ) {

            if (nextChar >= nChars)
                fill();
            if (nextChar >= nChars) { /* EOF */
                if (s != null && s.length() > 0)
                    return s.toString();
                else
                    return null;
            }
            boolean eol = false;
            char c = 0;
            int i;

            /* Skip a leftover '\n', if necessary */



            charLoop:
            for (i = nextChar; i < nChars; i++) {
                c = cb[i];
                if ((c == '\n')) {
                    eol = true;
                    break charLoop;
                }
            }

            startChar = nextChar;
            nextChar = i;

            if (eol) {
                String str;
                if (s == null) {
                    str = new String(cb, startChar, i - startChar);
                } else {
                    s.append(cb, startChar, i - startChar);
                    str = s.toString();
                }
                nextChar++;
                return str;
            }

            if (s == null)
                s = new StringBuilder(defaultExpectedLineLength);
            s.append(cb, startChar, i - startChar);
        }
    }

    /**
     * Reads a line of text.  A line is considered to be terminated by any one
     * of a line feed ('\n'), a carriage return ('\r'), or a carriage return
     * followed immediately by a linefeed.
     *
     * @return A String containing the contents of the line, not including
     * any line-termination characters, or null if the end of the
     * stream has been reached
     * @throws IOException If an I/O error occurs
     * @see java.nio.file.Files#readAllLines
     */
    public String readLine() throws IOException {
        return readLine(false);
    }

    /**
     * Skips characters.
     *
     * @param n The number of characters to skip
     * @return The number of characters actually skipped
     * @throws IllegalArgumentException If <code>n</code> is negative.
     * @throws IOException              If an I/O error occurs
     */
    public long skip(long n) throws IOException {
        if (n < 0L) {
            throw new IllegalArgumentException("skip value is negative");
        }
        rwlock.readLock().lock();
            long r = n;
            try{
            while (r > 0) {
                if (nextChar >= nChars)
                    fill();
                if (nextChar >= nChars) /* EOF */
                    break;
                if (skipLF) {
                    skipLF = false;
                    if (cb[nextChar] == '\n') {
                        nextChar++;
                    }
                }
                long d = nChars - nextChar;
                if (r <= d) {
                    nextChar += r;
                    r = 0;
                    break;
                } else {
                    r -= d;
                    nextChar = nChars;
                }
            }
        } finally {
            rwlock.readLock().unlock();
        }
        return n - r;
    }

    /**
     * Tells whether this stream is ready to be read.  A buffered character
     * stream is ready if the buffer is not empty, or if the underlying
     * character stream is ready.
     *
     * @throws IOException If an I/O error occurs
     */
    public boolean ready() throws IOException {
        rwlock.readLock().lock();
        try {
            /*
             * If newline needs to be skipped and the next char to be read
             * is a newline character, then just skip it right away.
             */
            if (skipLF) {
                /* Note that in.ready() will return true if and only if the next
                 * read on the stream will not block.
                 */
                if (nextChar >= nChars && in.ready()) {
                    fill();
                }
                if (nextChar < nChars) {
                    if (cb[nextChar] == '\n')
                        nextChar++;
                    skipLF = false;
                }
            }
        } finally {
            rwlock.readLock().unlock();
        }
        return (nextChar < nChars) || in.ready();

    }

    /**
     * Tells whether this stream supports the mark() operation, which it does.
     */
    public boolean markSupported() {
        return true;
    }

    /**
     * Marks the present position in the stream.  Subsequent calls to reset()
     * will attempt to reposition the stream to this point.
     *
     * @param readAheadLimit Limit on the number of characters that may be
     *                       read while still preserving the mark. An attempt
     *                       to reset the stream after reading characters
     *                       up to this limit or beyond may fail.
     *                       A limit value larger than the size of the input
     *                       buffer will cause a new buffer to be allocated
     *                       whose size is no smaller than limit.
     *                       Therefore large values should be used with care.
     * @throws IllegalArgumentException If {@code readAheadLimit < 0}
     * @throws IOException              If an I/O error occurs
     */
    public void mark(int readAheadLimit) throws IOException {
        if (readAheadLimit < 0) {
            throw new IllegalArgumentException("Read-ahead limit < 0");
        }
        rwlock.readLock().lock();
        try {
            this.readAheadLimit = readAheadLimit;
            markedChar = nextChar;
            markedSkipLF = skipLF;
        } finally {
            rwlock.readLock().unlock();
        }
    }

    /**
     * Resets the stream to the most recent mark.
     *
     * @throws IOException If the stream has never been marked,
     *                     or if the mark has been invalidated
     */
    public void reset() throws IOException {
        rwlock.readLock().lock();
        try {
            if (markedChar < 0)
                throw new IOException((markedChar == INVALIDATED)
                        ? "Mark invalid"
                        : "Stream not marked");
            nextChar = markedChar;
            skipLF = markedSkipLF;
        } finally {
            rwlock.readLock().unlock();
        }
    }

    public void close() throws IOException {
        rwlock.readLock().lock();
        try {
            in.close();
        } finally {
            cb = null;
            rwlock.readLock().unlock();
        }

    }

    public Stream<String> lines() {
        Iterator<String> iter = new Iterator<String>() {
            String nextLine = null;

            @Override
            public boolean hasNext() {
                if (nextLine != null) {
                    return true;
                } else {
                    try {
                        nextLine = readLine();
                        return (nextLine != null);
                    } catch (IOException e) {
                        throw new UncheckedIOException(e);
                    }
                }
            }

            @Override
            public String next() {
                if (nextLine != null || hasNext()) {
                    String line = nextLine;
                    nextLine = null;
                    return line;
                } else {
                    throw new NoSuchElementException();
                }
            }
        };
        return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
                iter, Spliterator.ORDERED | Spliterator.NONNULL), false);
    }
}

And now the results:

Time taken for readFileUsingBufferedReaderFileChannel 2902690903 1845190694 1894071377 1815161868 1861056735 1867693540 1857521371 1794176251 1768008762 1853089582

Time taken for readFileUsingBufferedReader 2022837353 1925901163 1802266711 1842689572 1899984555 1843101306 1998642345 1821242301 1820168806 1830375108

Time taken for readFileUsingStreams 1992855461 1930827034 1850876033 1843402533 1800378283 1863581324 1810857226 1798497108 1809531144 1796345853

Time taken for readFileUsingCustomBufferedReader 1759732702 1765987214 1776997357 1772999486 1768559162 1755248431 1744434555 1750349867 1740582606 1751390934

Time taken for readFileUsingLineReader 1845307174 1830950256 1829847321 1828125293 1827936280 1836947487 1832186310 1820276327 1830157935 1829171481

Process finished with exit code 0

Inference: The test was run on a 200 MB file. The test was repeated several times. The data looked like this

Start Date^|^Start Time^|^End Date^|^End Time^|^Event Title ^|^All Day Event^|^No End Time^|^Event Description^|^Contact ^|^Contact Email^|^Contact Phone^|^Location^|^Category^|^Mandatory^|^Registration^|^Maximum^|^Last Date To Register
9/5/2011^|^3:00:00 PM^|^9/5/2011^|^^|^Social Studies Dept. Meeting^|^N^|^Y^|^Department meeting^|^Chris Gallagher^|^[email protected]^|^814-555-5179^|^High School^|^2^|^N^|^N^|^25^|^9/2/2011

Bottomline not much difference between BufferedReader and my CustomReader and it is very miniscule and hence you can use this to read your file.

Trust me you don't have to break your head.use BufferedReader with readLine,it is properly tested.At worst if you feel you can improve it just override and change it to StringBuilder instead of StringBuffer just to shave off half a second

Return rows in random order

To be efficient, and random, it might be best to have two different queries.

Something like...

SELECT table_id FROM table

Then, in your chosen language, pick a random id, then pull that row's data.

SELECT * FROM table WHERE table_id = $rand_id

But that's not really a good idea if you're expecting to have lots of rows in the table. It would be better if you put some kind of limit on what you randomly select from. For publications, maybe randomly pick from only items posted within the last year.

How to set an image's width and height without stretching it?

#logo {
    width: 400px;
    height: 200px;

    /*Scale down will take the necessary specified space that is 400px x 200px without stretching the image*/
    object-fit:scale-down;
}

Nested routes with react router v4 / v5

You can try something like Routes.js

import React, { Component } from 'react'
import { BrowserRouter as Router, Route } from 'react-router-dom';
import FrontPage from './FrontPage';
import Dashboard from './Dashboard';
import AboutPage from './AboutPage';
import Backend from './Backend';
import Homepage from './Homepage';
import UserPage from './UserPage';
class Routes extends Component {
    render() {
        return (
            <div>
                <Route exact path="/" component={FrontPage} />
                <Route exact path="/home" component={Homepage} />
                <Route exact path="/about" component={AboutPage} />
                <Route exact path="/admin" component={Backend} />
                <Route exact path="/admin/home" component={Dashboard} />
                <Route exact path="/users" component={UserPage} />    
            </div>
        )
    }
}

export default Routes

App.js

import React, { Component } from 'react';
import logo from './logo.svg';
import './App.css';
import { BrowserRouter as Router, Route } from 'react-router-dom'
import Routes from './Routes';

class App extends Component {
  render() {
    return (
      <div className="App">
      <Router>
        <Routes/>
      </Router>
      </div>
    );
  }
}

export default App;

I think you can achieve the same from here also.

File Upload to HTTP server in iphone programming

Try this.. very easy to understand & implementation...

You can download sample code directly here https://github.com/Tech-Dev-Mobile/Json-Sample

- (void)simpleJsonParsingPostMetod
{

#warning set webservice url and parse POST method in JSON
    //-- Temp Initialized variables
    NSString *first_name;
    NSString *image_name;
    NSData *imageData;

    //-- Convert string into URL
    NSString *urlString = [NSString stringWithFormat:@"demo.com/your_server_db_name/service/link"];
    NSMutableURLRequest *request =[[NSMutableURLRequest alloc] init];
    [request setURL:[NSURL URLWithString:urlString]];
    [request setHTTPMethod:@"POST"];

    NSString *boundary = @"14737809831466499882746641449";
    NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",boundary];
    [request addValue:contentType forHTTPHeaderField: @"Content-Type"];

    //-- Append data into posr url using following method
    NSMutableData *body = [NSMutableData data];


    //-- For Sending text

        //-- "firstname" is keyword form service
        //-- "first_name" is the text which we have to send
    [body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n\r\n",@"firstname"] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[[NSString stringWithFormat:@"%@",first_name] dataUsingEncoding:NSUTF8StringEncoding]];


    //-- For sending image into service if needed (send image as imagedata)

        //-- "image_name" is file name of the image (we can set custom name)
    [body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];

    [body appendData:[[NSString stringWithFormat:@"Content-Disposition:form-data; name=\"file\"; filename=\"%@\"\r\n",image_name] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[@"Content-Type: application/octet-stream\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[NSData dataWithData:imageData]];
    [body appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];


    //-- Sending data into server through URL
    [request setHTTPBody:body];

    //-- Getting response form server
    NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];

    //-- JSON Parsing with response data
    NSDictionary *result = [NSJSONSerialization JSONObjectWithData:responseData options:NSJSONReadingMutableContainers error:nil];
    NSLog(@"Result = %@",result);
}

Subtract days from a DateTime

You can do:

DateTime.Today.AddDays(-1)

How to remove empty cells in UITableView?

Swift 3 syntax:

tableView.tableFooterView = UIView(frame: .zero)

Swift syntax: < 2.0

tableView.tableFooterView = UIView(frame: CGRect.zeroRect)

Swift 2.0 syntax:

tableView.tableFooterView = UIView(frame: CGRect.zero)

HTML/Javascript: how to access JSON data loaded in a script tag with src set

Check this answer: https://stackoverflow.com/a/7346598/1764509

$.getJSON("test.json", function(json) {
    console.log(json); // this will show the info it in firebug console
});

Change bundle identifier in Xcode when submitting my first app in IOS

If you are developing a cordova app, make sure to change the version and bundle identifier in the config.xml as well

use regular expression in if-condition in bash

When using a glob pattern, a question mark represents a single character and an asterisk represents a sequence of zero or more characters:

if [[ $gg == ????grid* ]] ; then echo $gg; fi

When using a regular expression, a dot represents a single character and an asterisk represents zero or more of the preceding character. So ".*" represents zero or more of any character, "a*" represents zero or more "a", "[0-9]*" represents zero or more digits. Another useful one (among many) is the plus sign which represents one or more of the preceding character. So "[a-z]+" represents one or more lowercase alpha character (in the C locale - and some others).

if [[ $gg =~ ^....grid.*$ ]] ; then echo $gg; fi

Removing html5 required attribute with jQuery

_x000D_
_x000D_
$('#id').removeAttr('required');?????
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
_x000D_
_x000D_
_x000D_

AttributeError: 'module' object has no attribute 'urlretrieve'

Suppose you have following lines of code

MyUrl = "www.google.com" #Your url goes here
urllib.urlretrieve(MyUrl)

If you are receiving following error message

AttributeError: module 'urllib' has no attribute 'urlretrieve'

Then you should try following code to fix the issue:

import urllib.request
MyUrl = "www.google.com" #Your url goes here
urllib.request.urlretrieve(MyUrl)

Using Postman to access OAuth 2.0 Google APIs

The current answer is outdated. Here's the up-to-date flow:

The approach outlined here still works (10.12.2020) as confirmed by alexwhan.

We will use the YouTube Data API for our example. Make changes accordingly.

Make sure you have enabled your desired API for your project.

Create the OAuth 2.0 Client

  1. Visit https://console.cloud.google.com/apis/credentials
  2. Click on CREATE CREDENTIALS
  3. Select OAuth client ID
  4. For Application Type choose Web Application
  5. Add a name
  6. Add following URI for Authorized redirect URIs
https://oauth.pstmn.io/v1/callback
  1. Click Save
  2. Click on the OAuth client you just generated
  3. In the Topbar click on DOWNLOAD JSON and save the file somewhere on your machine.

We will use the file later to authenticate Postman.

Authorize Postman via OAuth 2.0 Client

  1. In the Auth tab under TYPE choose OAuth 2.0
  2. For Access Token enter the Access Token found inside the client_secret_[YourClientID].json file we downloaded in step 9
  3. Click on Get New Access Token
  4. Make sure your settings are as follows:

Click here to see the settings

You can find everything else you need in your .json file.

  1. Click on Request Token
  2. A new browser tab/window will open
  3. Once the browser tab opens, login via the appropriate Google account
  4. Accept the consent screen
  5. Done

Ignore the browser message "Not safe" etc. This will be shown until your app has been screened by Google officials. In this case it will always be shown since Postman is the app.

Android adding simple animations while setvisibility(view.Gone)

Base on @ashakirov answer, here is my extension to show/hide view with fade animation

fun View.fadeVisibility(visibility: Int, duration: Long = 400) {
    val transition: Transition = Fade()
    transition.duration = duration
    transition.addTarget(this)
    TransitionManager.beginDelayedTransition(this.parent as ViewGroup, transition)
    this.visibility = visibility
}

Example using

view.fadeVisibility(View.VISIBLE)
view.fadeVisibility(View.GONE, 2000)

sqlite database default time value 'now'

i believe you can use

CREATE TABLE test (
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  t TIMESTAMP
  DEFAULT CURRENT_TIMESTAMP
);

as of version 3.1 (source)

Save and load weights in keras

Here is a YouTube video that explains exactly what you're wanting to do: Save and load a Keras model

There are three different saving methods that Keras makes available. These are described in the video link above (with examples), as well as below.

First, the reason you're receiving the error is because you're calling load_model incorrectly.

To save and load the weights of the model, you would first use

model.save_weights('my_model_weights.h5')

to save the weights, as you've displayed. To load the weights, you would first need to build your model, and then call load_weights on the model, as in

model.load_weights('my_model_weights.h5')

Another saving technique is model.save(filepath). This save function saves:

  • The architecture of the model, allowing to re-create the model.
  • The weights of the model.
  • The training configuration (loss, optimizer).
  • The state of the optimizer, allowing to resume training exactly where you left off.

To load this saved model, you would use the following:

from keras.models import load_model
new_model = load_model(filepath)'

Lastly, model.to_json(), saves only the architecture of the model. To load the architecture, you would use

from keras.models import model_from_json
model = model_from_json(json_string)

configuring project ':app' failed to find Build Tools revision

It happens because Build Tools revision 24.4.1 doesn't exist.

The latest version is 23.0.2.
These tools is included in the SDK package and installed in the <sdk>/build-tools/ directory.

Don't confuse the Android SDK Tools with SDK Build Tools.

Change in your build.gradle

android {
   buildToolsVersion "23.0.2"
   // ...

}

Connect Device to Mac localhost Server?

I suggest to use the name of the computer, e.g.http://mymac:1337/. Works for me perfect without any configuration required and I don't have to care about changing IP addresses due DHCP.

How can I set a UITableView to grouped style

For set grouped style in ui itself:-Select the TableView then change the "style"(in attribute inspector)) from plain to Grouped.

Get environment value in controller

You can use with this format (tested on Laravel 5.5). In my case I used it for gettting the data of database connections and use on Controller:

$User = env('DB_USERNAMEchild','');
$Pass = env('DB_PASSWORDchild','');

The second parameter can be null, or set any default in case of DB_USERNAMEchild is null.

Your .env file can be the same:

DB_HOST=localhost
DB_DATABASE=FATHERBD
DB_USERNAME=root
DB_PASSWORD=password

DB_DATABASEchild=ZTEST
DB_USERNAMEchild=root
DB_PASSWORDchild=passwordofchild

Cannot implicitly convert type 'int?' to 'int'.

You can change the last line to following (assuming you want to return 0 when there is nothing in db):

return OrdersPerHour == null ? 0 : OrdersPerHour.Value;

How to get my Android device Internal Download Folder path

if a device has an SD card, you use:

Environment.getExternalStorageState() 

if you don't have an SD card, you use:

Environment.getDataDirectory()

if there is no SD card, you can create your own directory on the device locally.

    //if there is no SD card, create new directory objects to make directory on device
        if (Environment.getExternalStorageState() == null) {
                        //create new file directory object
            directory = new File(Environment.getDataDirectory()
                    + "/RobotiumTestLog/");
            photoDirectory = new File(Environment.getDataDirectory()
                    + "/Robotium-Screenshots/");
            /*
             * this checks to see if there are any previous test photo files
             * if there are any photos, they are deleted for the sake of
             * memory
             */
            if (photoDirectory.exists()) {
                File[] dirFiles = photoDirectory.listFiles();
                if (dirFiles.length != 0) {
                    for (int ii = 0; ii <= dirFiles.length; ii++) {
                        dirFiles[ii].delete();
                    }
                }
            }
            // if no directory exists, create new directory
            if (!directory.exists()) {
                directory.mkdir();
            }

            // if phone DOES have sd card
        } else if (Environment.getExternalStorageState() != null) {
            // search for directory on SD card
            directory = new File(Environment.getExternalStorageDirectory()
                    + "/RobotiumTestLog/");
            photoDirectory = new File(
                    Environment.getExternalStorageDirectory()
                            + "/Robotium-Screenshots/");
            if (photoDirectory.exists()) {
                File[] dirFiles = photoDirectory.listFiles();
                if (dirFiles.length > 0) {
                    for (int ii = 0; ii < dirFiles.length; ii++) {
                        dirFiles[ii].delete();
                    }
                    dirFiles = null;
                }
            }
            // if no directory exists, create new directory to store test
            // results
            if (!directory.exists()) {
                directory.mkdir();
            }
        }// end of SD card checking

add permissions on your manifest.xml

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Happy coding..

SSIS Connection not found in package

I had same issue in my case, the cause was connection was not embedded and incompatibility of Oracle Client.

SOLUTION:

My Environment:SQL SERVER 2014 64bit Oracle Client 32 bit

  1. For include/embed Connection

    • open package
    • right click on connection
    • select "Convert to project" option
  2. for SQL SSIS Catalog/Job schedule set the configuration follow steps in picture

    • Right on 'SQL JOB->Step" or "SSIS Catalog-->Package-->Execute" and select "Properties"
    • Select Configuration-->Advanced tab
    • Checked 32-bit runtime

I tried to post detail step by step pictures, but Stack Overflow does not allow that due to reputation. Hope I later will update this post.

How to replace captured groups only?

A solution is to add captures for the preceding and following text:

str.replace(/(.*name="\w+)(\d+)(\w+".*)/, "$1!NEW_ID!$3")

How to render string with html tags in Angular 4+?

Use one way flow syntax property binding:

<div [innerHTML]="comment"></div>

From angular docs: "Angular recognizes the value as unsafe and automatically sanitizes it, which removes the <script> tag but keeps safe content such as the <b> element."

Update GCC on OSX

If you install macports you can install gcc select, and then choose your gcc version.

/opt/local/bin/port install gcc_select

To see your versions use

port select --list gcc

To select a version use

sudo port select --set gcc gcc40

Font is not available to the JVM with Jasper Reports

Hey Having trouble viewing documents produced on Windows?

You can try a fine solution easy:

yum install curl cabextract xorg-x11-font-utils fontconfig

rpm -i https://downloads.sourceforge.net/project/mscorefonts2/rpms/msttcore-fonts-installer-2.6-1.noarch.rpm

After this I need reboot my system CentOS6.

Source: http://mscorefonts2.sourceforge.net/

How to get the current date and time of your timezone in Java?

As Jon Skeet already said, java.util.Date does not have a time zone. A Date object represents a number of milliseconds since January 1, 1970, 12:00 AM, UTC. It does not contain time zone information.

When you format a Date object into a string, for example by using SimpleDateFormat, then you can set the time zone on the DateFormat object to let it know in which time zone you want to display the date and time:

Date date = new Date();
DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

// Use Madrid's time zone to format the date in
df.setTimeZone(TimeZone.getTimeZone("Europe/Madrid"));

System.out.println("Date and time in Madrid: " + df.format(date));

If you want the local time zone of the computer that your program is running on, use:

df.setTimeZone(TimeZone.getDefault());

Best way to detect when a user leaves a web page?

Mozilla Developer Network has a nice description and example of onbeforeunload.

If you want to warn the user before leaving the page if your page is dirty (i.e. if user has entered some data):

window.addEventListener('beforeunload', function(e) {
  var myPageIsDirty = ...; //you implement this logic...
  if(myPageIsDirty) {
    //following two lines will cause the browser to ask the user if they
    //want to leave. The text of this dialog is controlled by the browser.
    e.preventDefault(); //per the standard
    e.returnValue = ''; //required for Chrome
  }
  //else: user is allowed to leave without a warning dialog
});

How to keep console window open

Put a Console.Read() as the last line in your program. That will prevent it from closing until you press a key

static void Main(string[] args)
{
    StringAddString s = new StringAddString();
    Console.Read();            
}

Get Base64 encode file-data from Input Form

My solution was use readAsBinaryString() and btoa() on its result.

uploadFileToServer(event) {
    var file = event.srcElement.files[0];
    console.log(file);
    var reader = new FileReader();
    reader.readAsBinaryString(file);

    reader.onload = function() {
        console.log(btoa(reader.result));
    };
    reader.onerror = function() {
        console.log('there are some problems');
    };
}

How may I sort a list alphabetically using jQuery?

I was looking to do this myself, and I wasnt satisfied with any of the answers provided simply because, I believe, they are quadratic time, and I need to do this on lists hundreds of items long.

I ended up extending jquery, and my solution uses jquery, but could easily be modified to use straight javascript.

I only access each item twice, and perform one linearithmic sort, so this should, I think, work out to be a lot faster on large datasets, though I freely confess I could be mistaken there:

sortList: function() {
   if (!this.is("ul") || !this.length)
      return
   else {
      var getData = function(ul) {
         var lis     = ul.find('li'),
             liData  = {
               liTexts : []
            }; 

         for(var i = 0; i<lis.length; i++){
             var key              = $(lis[i]).text().trim().toLowerCase().replace(/\s/g, ""),
             attrs                = lis[i].attributes;
             liData[key]          = {},
             liData[key]['attrs'] = {},
             liData[key]['html']  = $(lis[i]).html();

             liData.liTexts.push(key);

             for (var j = 0; j < attrs.length; j++) {
                liData[key]['attrs'][attrs[j].nodeName] = attrs[j].nodeValue;
             }
          }

          return liData;
       },

       processData = function (obj){
          var sortedTexts = obj.liTexts.sort(),
              htmlStr     = '';

          for(var i = 0; i < sortedTexts.length; i++){
             var attrsStr   = '',
                 attributes = obj[sortedTexts[i]].attrs;

             for(attr in attributes){
                var str = attr + "=\'" + attributes[attr] + "\' ";
                attrsStr += str;
             }

             htmlStr += "<li "+ attrsStr + ">" + obj[sortedTexts[i]].html+"</li>";
          }

          return htmlStr;

       };

       this.html(processData(getData(this)));
    }
}

getActionBar() returns null

Just check the implementation of source code by command click:

    private void initWindowDecorActionBar() {
    Window window = getWindow();

    // Initializing the window decor can change window feature flags.
    // Make sure that we have the correct set before performing the test below.
    window.getDecorView();

    if (isChild() || !window.hasFeature(Window.FEATURE_ACTION_BAR) || mActionBar != null) {
        return;
    }

    mActionBar = new WindowDecorActionBar(this);
    mActionBar.setDefaultDisplayHomeAsUpEnabled(mEnableDefaultActionBarUp);

    mWindow.setDefaultIcon(mActivityInfo.getIconResource());
    mWindow.setDefaultLogo(mActivityInfo.getLogoResource());
}

requestWindowFeature(Window.FEATURE_ACTION_BAR); Fixed my issue as I saw requestWindowFeature(Window.FEATURE_ACTION_BAR) is failing; code is open source use it !!

Separating class code into a header and cpp file

Basically a modified syntax of function declaration/definitions:

a2dd.h

class A2DD
{
private:
  int gx;
  int gy;

public:
  A2DD(int x,int y);

  int getSum();
};

a2dd.cpp

A2DD::A2DD(int x,int y)
{
  gx = x;
  gy = y;
}

int A2DD::getSum()
{
  return gx + gy;
}

Can't create a docker image for COPY failed: stat /var/lib/docker/tmp/docker-builder error

In your case removing ./ should solve the issue. I had another case wherein I was using a directory from the parent directory and docker can only access files present below the directory where Dockerfile is present so if I have a directory structure /root/dir and Dockerfile /root/dir/Dockerfile

I cannot copy do the following

COPY root/src /opt/src

How to make jQuery UI nav menu horizontal?

I admire all these efforts to convert a menu to a menubar because I detest trying to hack CSS. It just feels like I'm meddling with powers I can't possibly ever understand! I think it's much easier to add the menubar files available at the menubar branch of jquery ui.

I downloaded the full jquery ui css bundled file from the jquery ui download site

In the head of my document I put the jquery ui css file that contains everything (I'm on version 1.9.x at the moment) followed by the specific CSS file for the menubar widget downloaded from the menubar branch of jquery ui

<link type="text/css" href="css/jquery-ui.css" rel="stylesheet" />
<link type="text/css" href="css/jquery.ui.menubar.css" rel="stylesheet" />

Don't forget the images folder with all the little icons used by jQuery UI needs to be in the same folder as the jquery-ui.css file.

Then at the end the body I have:

<script type="text/javascript" src="js/jquery-1.8.2.min.js"></script>
<script type="text/javascript" src="js/jquery-ui-1.9.0.custom.min.js"></script>
<script type="text/javascript" src="js/menubar/jquery.ui.menubar.js"></script>

That's a copy of an up-to-date version of jQuery, followed by a copy of the jQuery UI file, then the menubar module downloaded from the menubar branch of jquery ui

The menubar CSS file is refreshingly short:

.ui-menubar { list-style: none; margin: 0; padding-left: 0; }
.ui-menubar-item { float: left; }
.ui-menubar .ui-button { float: left; font-weight: normal; border-top-width: 0 !important; border-bottom-width: 0 !important; margin: 0; outline: none; }
.ui-menubar .ui-menubar-link { border-right: 1px dashed transparent; border-left: 1px dashed transparent; }
.ui-menubar .ui-menu { width: 200px; position: absolute; z-index: 9999; font-weight: normal; }

but the menubar JavaScript file is 328 lines - too long to quote here. With it, you can simply call menubar() like this example:

$("#menu").menubar({
    autoExpand: true,
    menuIcon: true,
    buttons: true,
    select: select
});

As I said, I admire all the attempts to hack the menu object to turn it into a horizontal bar, but I found all of them lacked some standard feature of a horizontal menu bar. I'm not sure why this widget is not bundled with jQuery UI yet, but presumably there are still some bugs to iron out. For instance, I tried it in IE 7 Quirks Mode and the positioning was strange, but it looks great in Firefox, Safari and IE 8+.

C# Linq Where Date Between 2 Dates

var QueryNew = _context.Appointments.Include(x => x.Employee).Include(x => x.city).Where(x => x.CreatedOn >= FromDate).Where(x => x.CreatedOn <= ToDate).Where(x => x.IsActive == true).ToList();

"You may need an appropriate loader to handle this file type" with Webpack and Babel

Due to updates and changes overtime, version compatibility start causing issues with configuration.

Your webpack.config.js should be like this you can also configure how ever you dim fit.

var path = require('path');
var webpack = require("webpack");

module.exports = {
  entry: './src/js/app.js',
  devtool: 'source-map',
    mode: 'development',
  module: {
    rules: [{
      test: /\.js$/,
      exclude: /node_modules/,
      use: ["babel-loader"]
    },{
      test: /\.css$/,
      use: ['style-loader', 'css-loader']
    }]
  },
  output: {
    path: path.resolve(__dirname, './src/vendor'),
    filename: 'bundle.min.js'
  }
};

Another Thing to notice it's the change of args, you should read babel documentation https://babeljs.io/docs/en/presets

.babelrc

{
    "presets": ["@babel/preset-env", "@babel/preset-react"]
}

NB: you have to make sure you have the above @babel/preset-env & @babel/preset-react installed in your package.json dependencies

ISO C++ forbids comparison between pointer and integer [-fpermissive]| [c++]

char a[2] defines an array of char's. a is a pointer to the memory at the beginning of the array and using == won't actually compare the contents of a with 'ab' because they aren't actually the same types, 'ab' is integer type. Also 'ab' should be "ab" otherwise you'll have problems here too. To compare arrays of char you'd want to use strcmp.

Something that might be illustrative is looking at the typeid of 'ab':

#include <iostream>
#include <typeinfo>
using namespace std;
int main(){
    int some_int =5;
    std::cout << typeid('ab').name() << std::endl;
    std::cout << typeid(some_int).name() << std::endl;
    return 0;
}

on my system this returns:

i
i

showing that 'ab' is actually evaluated as an int.

If you were to do the same thing with a std::string then you would be dealing with a class and std::string has operator == overloaded and will do a comparison check when called this way.

If you wish to compare the input with the string "ab" in an idiomatic c++ way I suggest you do it like so:

#include <iostream>
#include <string>
using namespace std;
int main(){
    string a;
    cout<<"enter ab ";
    cin>>a;
    if(a=="ab"){
         cout<<"correct";
    }
    return 0;
}

This one is due to:

if(a=='ab') , here, a is const char* type (ie : array of char)

'ab' is a constant value,which isn't evaluated as string (because of single quote) but will be evaluated as integer.

Since char is a primitive type inherited from C, no operator == is defined.

the good code should be:

if(strcmp(a,"ab")==0) , then you'll compare a const char* to another const char* using strcmp.

How can I tell what edition of SQL Server runs on the machine?

I use this query here to get all relevant info (relevant for me, at least :-)) from SQL Server:

SELECT  
    SERVERPROPERTY('productversion') as 'Product Version', 
    SERVERPROPERTY('productlevel') as 'Product Level',  
    SERVERPROPERTY('edition') as 'Product Edition',
    SERVERPROPERTY('buildclrversion') as 'CLR Version',
    SERVERPROPERTY('collation') as 'Default Collation',
    SERVERPROPERTY('instancename') as 'Instance',
    SERVERPROPERTY('lcid') as 'LCID',
    SERVERPROPERTY('servername') as 'Server Name'

That gives you an output something like this:

Product Version   Product Level   Product Edition             CLR Version   
10.0.2531.0       SP1             Developer Edition (64-bit)    v2.0.50727  

Default Collation     Instance   LCID   Server Name 
Latin1_General_CI_AS     NULL    1033   *********       

Android Center text on canvas

Align vertically is difficult because text descent and ascent happened, lots of guys used Paint.getTextBounds() to retrieve the TextWidth and TextHeight, but it doesn't make the text center very much. Here we can use Paint.measureText() to calculate the TextWidth, the TextHeight we simply do subtracting with descent and ascent, then we got the most approach TextSize, the following work is fairly easy for each other.

// the Paint instance(should be assign as a field of class).
Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mPaint.setTextSize(getResources().getDimension(R.dimen.btn_textsize));

// the display area.
Rect areaRect = new Rect(0, 0, 240, 60);

// draw the background style (pure color or image)
mPaint.setColor(Color.BLACK);
yourCanvas.drawRect(areaRect, mPaint);

String pageTitle = "????";

RectF bounds = new RectF(areaRect);
// measure text width
bounds.right = mPaint.measureText(pageTitle, 0, pageTitle.length());
// measure text height
bounds.bottom = mPaint.descent() - mPaint.ascent();

bounds.left += (areaRect.width() - bounds.right) / 2.0f;
bounds.top += (areaRect.height() - bounds.bottom) / 2.0f;

mPaint.setColor(Color.WHITE);
yourCanvas.drawText(pageTitle, bounds.left, bounds.top - mPaint.ascent(), mPaint);

screen shot by the code

By the way, we highly recommend use RectF rather than Rect because the positions need more accurate values, in my experience, RectF done the top&bottom deviation just one pixel on xhdpi device, Rect would be two more.

HashMap and int as key

Please use HashMap<Integer, myObject> myMap = new HashMap<Integer, myObject>();

How to run a cron job inside a docker container?

Unfortunately, none of the above answers worked for me, although all answers lead to the solution and eventually to my solution, here is the snippet if it helps someone. Thanks

This can be solved with the bash file, due to the layered architecture of the Docker, cron service doesn't get initiated with RUN/CMD/ENTRYPOINT commands.

Simply add a bash file which will initiate the cron and other services (if required)

DockerFile

FROM gradle:6.5.1-jdk11 AS build
# apt
RUN apt-get update
RUN apt-get -y install cron
# Setup cron to run every minute to print (you can add/update your cron here)
RUN touch /var/log/cron-1.log
RUN (crontab -l ; echo "* * * * * echo testing cron.... >> /var/log/cron-1.log 2>&1") | crontab
# entrypoint.sh
RUN chmod +x entrypoint.sh
CMD ["bash","entrypoint.sh"]

entrypoint.sh

#!/bin/sh
service cron start & tail -f /var/log/cron-2.log

If any other service is also required to run along with cron then add that service with & in the same command, for example: /opt/wildfly/bin/standalone.sh & service cron start & tail -f /var/log/cron-2.log

Once you will get into the docker container there you can see that testing cron.... will be getting printed every minute in file: /var/log/cron-1.log

Access Database opens as read only

The main reason for this is when the database is open somewhere else.

This could be as already said by many others:

  • not being closed properly somewhere
  • already open somewhere

When recently I had the same problem although different versions, I started to search for the reason.

In my case I had an excel file that queried data from the database.

In case the excel file is opened before the database, access would give this error.

Conclusion:

Check all files/connections related to the database. An open ODBC connection or query used in excel (my case) open the mdb file and will make it readonly.

Difference between "Complete binary tree", "strict binary tree","full binary Tree"?

Disclaimer- The main source of some definitions are wikipedia, any suggestion to improve my answer is welcome.

Although this post has an accepted answer and is a good one I was still in confusion and would like to add some more clarification regarding the difference between these terms.

(1)FULL BINARY TREE- A full binary tree is a binary tree in which every node other than the leaves has two children.This is also called strictly binary tree.

enter image description here enter image description here

The above two are the examples of full or strictly binary tree.

(2)COMPLETE BINARY TREE- Now, the definition of complete binary tree is quite ambiguous, it states :- A complete binary tree is a binary tree in which every level, except possibly the last, is completely filled, and all nodes are as far left as possible. It can have between 1 and 2h nodes, as far left as possible, at the last level h

Notice the lines in italic.

The ambiguity lies in the lines in italics , "except possibly the last" which means that the last level may also be completely filled , i.e this exception need not always be satisfied. If the exception doesn't hold then it is exactly like the second image I posted, which can also be called as perfect binary tree. So, a perfect binary tree is also full and complete but not vice-versa which will be clear by one more definition I need to state:

ALMOST COMPLETE BINARY TREE- When the exception in the definition of complete binary tree holds then it is called almost complete binary tree or nearly complete binary tree . It is just a type of complete binary tree itself , but a separate definition is necessary to make it more unambiguous.

So an almost complete binary tree will look like this, you can see in the image the nodes are as far left as possible so it is more like a subset of complete binary tree , to say more rigorously every almost complete binary tree is a complete binary tree but not vice versa . :

enter image description here

Bootstrap 4 File Input

Updated 2021

Bootstrap 5

Custom file input no longer exists so to change Choose file... you'd need to use JS or some CSS like this.

Bootstrap 4.4

Displaying the selected filename can also be done with plain JavaScript. Here's an example that assumes the standard custom-file-input with label that is the next sibling element to the input...

document.querySelector('.custom-file-input').addEventListener('change',function(e){
  var fileName = document.getElementById("myInput").files[0].name;
  var nextSibling = e.target.nextElementSibling
  nextSibling.innerText = fileName
})

https://codeply.com/p/LtpNZllird

Bootstrap 4.1+

Now in Bootstrap 4.1 the "Choose file..." placeholder text is set in the custom-file-label:

<div class="custom-file" id="customFile" lang="es">
        <input type="file" class="custom-file-input" id="exampleInputFile" aria-describedby="fileHelp">
        <label class="custom-file-label" for="exampleInputFile">
           Select file...
        </label>
</div>

Changing the "Browse" button text requires a little extra CSS or SASS. Also notice how language translation works using the lang="" attribute.

.custom-file-input ~ .custom-file-label::after {
    content: "Button Text";
}

https://codeply.com/go/gnVCj66Efp (CSS)
https://codeply.com/go/2Mo9OrokBQ (SASS)

Another Bootstrap 4.1 Option

Alternatively you can use this custom file input plugin

https://www.codeply.com/go/uGJOpHUd8L/file-input


Bootstrap 4 Alpha 6 (Original Answer)

I think there are 2 separate issues here..

<label class="custom-file" id="customFile">
        <input type="file" class="custom-file-input">
        <span class="custom-file-control form-control-file"></span>
</label>

1 - How the change the initial placeholder and button text

In Bootstrap 4, the initial placeholder value is set on the custom-file-control with a CSS pseudo ::after element based on the HTML language. The initial file button (which isn't really a button but looks like one) is set with a CSS pseudo ::before element. These values can be overridden with CSS..

#customFile .custom-file-control:lang(en)::after {
  content: "Select file...";
}

#customFile .custom-file-control:lang(en)::before {
  content: "Click me";
}

2 - How to get the selected filename value, and update the input to show the value.

Once a file is selected, the value can be obtained using JavaScript/jQuery.

$('.custom-file-input').on('change',function(){
    var fileName = $(this).val();
})

However, since the placeholder text for the input is a pseudo element, there's no easy way to manipulate this with Js/jQuery. You can however, have a another CSS class that hides the pseudo content once the file is selected...

.custom-file-control.selected:lang(en)::after {
  content: "" !important;
}

Use jQuery to toggle the .selected class on the .custom-file-control once the file is selected. This will hide the initial placeholder value. Then put the filename value in the .form-control-file span...

$('.custom-file-input').on('change',function(){
  var fileName = $(this).val();
  $(this).next('.form-control-file').addClass("selected").html(fileName);
})

You can then handle the file upload or re-selection as needed.

Demo on Codeply (alpha 6)

Resizing Images in VB.NET

Don't know much VB.NET syntax but here's and idea

Dim source As New Bitmap("C:\image.png") 
Dim target As New Bitmap(size.Width, size.Height, PixelFormat.Format24bppRgb)

Using graphics As Graphics = Graphics.FromImage(target)
    graphics.DrawImage(source, new Size(48, 48)) 
End Using

Warning "Do not Access Superglobal $_POST Array Directly" on Netbeans 7.4 for PHP

I agree with the other answerers that in most cases (almost always) it is necessary to sanitize Your input.

But consider such code (it is for a REST controller):

$method = $_SERVER['REQUEST_METHOD'];

switch ($method) {
            case 'GET':
                return $this->doGet($request, $object);
            case 'POST':
                return $this->doPost($request, $object);
            case 'PUT':
                return $this->doPut($request, $object);
            case 'DELETE':
                return $this->doDelete($request, $object);
            default:
                return $this->onBadRequest();
}

It would not be very useful to apply sanitizing here (although it would not break anything, either).

So, follow recommendations, but not blindly - rather understand why they are for :)

jQuery: Get the cursor position of text in input without browser specific code?

A warning about the Jquery Caret plugin.

It will conflict with the Masked Input plugin (or vice versa). Fortunately the Masked Input plugin includes a caret() function of its own, which you can use very similarly to the Caret plugin for your basic needs - $(element).caret().begin or .end

How can I connect to Android with ADB over TCP?

There are two ways to connect your Android device with ADB over TCP?

First way

Follow this steps

First use below command to get your device IP Address

adb shell ifconfig

OUTPUT of above command

wlan0     Link encap:UNSPEC    Driver icnss
          inet addr:XXX.XXX.X.XX  Bcast:XXX.XXX.X.XXX

With the help you above command you will find the IP Address of connected device

Now use below command

adb tcpip 5555

The above command will restart this TCP port: 5555

Now use below command to connect your device

adb connect XXX.XXX.X.XXX:5555
            ^^^ ^^^ ^ ^^^
        IP Address of device

Second way

You can use Android Studio Plugin Android device with ADB

Android WiFi ADB - IntelliJ/Android Studio Plugin

IntelliJ and Android Studio plugin created to quickly connect your Android device over WiFi to install, run and debug your applications without a USB connected. Press one button and forget about your USB cable

Please check this article for more information

Connect Android Device with Wifi within Android Studio

How to set default values in Rails?

First of all you can't overload initialize(*args) as it's not called in all cases.

Your best option is to put your defaults into your migration:

add_column :accounts, :max_users, :integer, :default => 10

Second best is to place defaults into your model but this will only work with attributes that are initially nil. You may have trouble as I did with boolean columns:

def after_initialize
  if new_record?
    max_users ||= 10
  end
end

You need the new_record? so the defaults don't override values loaded from the datbase.

You need ||= to stop Rails from overriding parameters passed into the initialize method.

Find distance between two points on map using Google Map API V2

In Google Map API V2 You have LatLng objects so you can't use distanceTo (yet).

You can then use the following code considering oldPosition and newPosition are LatLng objects :

// The computed distance is stored in results[0].
//If results has length 2 or greater, the initial bearing is stored in results[1].
//If results has length 3 or greater, the final bearing is stored in results[2].
float[] results = new float[1];
Location.distanceBetween(oldPosition.latitude, oldPosition.longitude,
                newPosition.latitude, newPosition.longitude, results);

For more informations about the Location class see this link

jQuery "blinking highlight" effect on div?

Check it out -

<input type="button" id="btnclick" value="click" />
var intervalA;
        var intervalB;

        $(document).ready(function () {

            $('#btnclick').click(function () {
                blinkFont();

                setTimeout(function () {
                    clearInterval(intervalA);
                    clearInterval(intervalB);
                }, 5000);
            });
        });

        function blinkFont() {
            document.getElementById("blink").style.color = "red"
            document.getElementById("blink").style.background = "black"
            intervalA = setTimeout("blinkFont()", 500);
        }

        function setblinkFont() {
            document.getElementById("blink").style.color = "black"
            document.getElementById("blink").style.background = "red"
            intervalB = setTimeout("blinkFont()", 500);
        }

    </script>

    <div id="blink" class="live-chat">
        <span>This is blinking text and background</span>
    </div>

How to throw std::exceptions with variable messages?

Use string literal operator if C++14 (operator ""s)

using namespace std::string_literals;

throw std::exception("Could not load config file '"s + configfile + "'"s);

or define your own if in C++11. For instance

std::string operator ""_s(const char * str, std::size_t len) {
    return std::string(str, str + len);
}

Your throw statement will then look like this

throw std::exception("Could not load config file '"_s + configfile + "'"_s);

which looks nice and clean.

Select From all tables - MySQL

As Suhel Meman said in the comments:

SELECT column1, column2, column3 FROM table 1
UNION
SELECT column1, column2, column3 FROM table 2
...

would work.

But all your SELECTS would have to consist of the same amount of columns. And because you are displaying it in one resulting table they should contain the same information.

What you might want to do, is a JOIN on Product ID or something like that. This way you would get more columns, which makes more sense most of the time.

Select specific row from mysql table

You can add an auto generated id field in the table and select by this id

SELECT * FROM CUSTOMER WHERE CUSTOMER_ID = 3;

Call a Vue.js component method from outside the component

I have used a very simple solution. I have included a HTML element, that calls the method, in my Vue Component that I select, using Vanilla JS, and I trigger click!

In the Vue Component, I have included something like the following:

<span data-id="btnReload" @click="fetchTaskList()"><i class="fa fa-refresh"></i></span>

That I use using Vanilla JS:

const btnReload = document.querySelector('[data-id="btnReload"]');
btnReload.click();                

Drop shadow on a div container?

.shadow {
    -moz-box-shadow:    3px 3px 5px 6px #ccc;
    -webkit-box-shadow: 3px 3px 5px 6px #ccc;
    box-shadow:         3px 3px 5px 6px #ccc;
}

How to use regex in file find

Use -regex:

From the man page:

-regex pattern
       File name matches regular expression pattern.  This is a match on the whole path, not a search.  For example, to match a file named './fubar3',  you  can  use  the
       regular expression '.*bar.' or '.*b.*3', but not 'b.*r3'.

Also, I don't believe find supports regex extensions such as \d. You need to use [0-9].

find . -regex '.*test\.log\.[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]\.zip'

How to make the overflow CSS property work with hidden as value

This worked for me

<div style="display: flex; position: absolute; width: 100%;">
  <div style="white-space: nowrap; overflow: hidden;text-overflow: ellipsis;">
    Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer nec odio. Praesent libero. Sed cursus ante dapibus diam. Sed nisi.
  </div>
</div>

Adding position:absolute to the parent container made it work.

PS: This is for anyone looking for a solution to dynamically truncating text.

EDIT: This was meant to be an answer for this question but since they are related and it could help someone on this question I shall also leave it here instead of deleting it.

How can I toggle word wrap in Visual Studio?

I use this feature often enough that I add a custom button to the command bar.

  1. Click on the Add or Remove Buttons -> Customize
  2. Click on the Commands tab
  3. Click Add Command...
  4. Select Edit (or Edit|Advanced for newer VS versions) from the list
  5. Find Toggle Word Wrap and drag it onto your bar

Working with $scope.$emit and $scope.$on

According to the angularjs event docs the receiving end should be containing arguments with a structure like

@params

-- {Object} event being the event object containing info on the event

-- {Object} args that are passed by the callee (Note that this can only be one so better to send in a dictionary object always)

$scope.$on('fooEvent', function (event, args) { console.log(args) }); From your code

Also if you are trying to get a shared piece of information to be available accross different controllers there is an another way to achieve that and that is angular services.Since the services are singletons information can be stored and fetched across controllers.Simply create getter and setter functions in that service, expose these functions, make global variables in the service and use them to store the info

casting int to char using C++ style casting

reinterpret_cast cannot be used for this conversion, the code will not compile. According to C++03 standard section 5.2.10-1:

Conversions that can be performed explicitly using reinterpret_cast are listed below. No other conversion can be performed explicitly using reinterpret_cast.

This conversion is not listed in that section. Even this is invalid:

long l = reinterpret_cast<long>(i)

static_cast is the one which has to be used here. See this and this SO questions.

How to add New Column with Value to the Existing DataTable?

//Data Table

 protected DataTable tblDynamic
        {
            get
            {
                return (DataTable)ViewState["tblDynamic"];
            }
            set
            {
                ViewState["tblDynamic"] = value;
            }
        }
//DynamicReport_GetUserType() function for getting data from DB


System.Data.DataSet ds = manage.DynamicReport_GetUserType();
                tblDynamic = ds.Tables[13];

//Add Column as "TypeName"

                tblDynamic.Columns.Add(new DataColumn("TypeName", typeof(string)));

//fill column data against ds.Tables[13]


                for (int i = 0; i < tblDynamic.Rows.Count; i++)
                {

                    if (tblDynamic.Rows[i]["Type"].ToString()=="A")
                    {
                        tblDynamic.Rows[i]["TypeName"] = "Apple";
                    }
                    if (tblDynamic.Rows[i]["Type"].ToString() == "B")
                    {
                        tblDynamic.Rows[i]["TypeName"] = "Ball";
                    }
                    if (tblDynamic.Rows[i]["Type"].ToString() == "C")
                    {
                        tblDynamic.Rows[i]["TypeName"] = "Cat";
                    }
                    if (tblDynamic.Rows[i]["Type"].ToString() == "D")
                    {
                        tblDynamic.Rows[i]["TypeName"] = "Dog;
                    }
                }

How to display a "busy" indicator with jQuery?

To extend Rodrigo's solution a little - for requests that are executed frequently, you may only want to display the loading image if the request takes more than a minimum time interval, otherwise the image will be continually popping up and quickly disappearing

var loading = false;

$.ajaxSetup({
    beforeSend: function () {
        // Display loading icon if AJAX call takes >1 second
        loading = true;
        setTimeout(function () {
            if (loading) {
                // show loading image
            }
        }, 1000);            
    },
    complete: function () {
        loading = false;
        // hide loading image
    }
});

error LNK2038: mismatch detected for '_MSC_VER': value '1600' doesn't match value '1700' in CppFile1.obj

I was importing also some projects from VS2010 to VS 2012. I had the same errors. The errors disappeared when I set back Properties > Config. Properties > General > Platform Toolset to v100 (VS2010). That might not be the correct approach, however.

How to stop event bubbling on checkbox click

replace

event.preventDefault();
return false;

with

event.stopPropagation();

event.stopPropagation()

Stops the bubbling of an event to parent elements, preventing any parent handlers from being notified of the event.

event.preventDefault()

Prevents the browser from executing the default action. Use the method isDefaultPrevented to know whether this method was ever called (on that event object).

Creating an XmlNode/XmlElement in C# without an XmlDocument?

You need Linq - System.Xml.Linq to be precise.

You can create XML using XElement from scratch - that should pretty much sort you out.

After installing SQL Server 2014 Express can't find local db

Most probably, you didn't install any SQL Server Engine service. If no SQL Server engine is installed, no service will appear in the SQL Server Configuration Manager tool. Consider that the packages SQLManagementStudio_Architecture_Language.exe and SQLEXPR_Architecture_Language.exe, available in the Microsoft site contain, respectively only the Management Studio GUI Tools and the SQL Server engine.

If you want to have a full featured SQL Server installation, with the database engine and Management Studio, download the installer file of SQL Server with Advanced Services. Moreover, to have a sample database in order to perform some local tests, use the Adventure Works database.

Considering the package of SQL Server with Advanced Services, at the beginning at the installation you should see something like this (the screenshot below is about SQL Server 2008 Express, but the feature selection is very similar). The checkbox next to "Database Engine Services" must be checked. In the next steps, you will be able to configure the instance settings and other options.

Execute again the installation process and select the database engine services in the feature selection step. At the end of the installation, you should be able to see the SQL Server services in the SQL Server Configuration Manager.

enter image description here

What is the difference between LATERAL and a subquery in PostgreSQL?

First, Lateral and Cross Apply is same thing. Therefore you may also read about Cross Apply. Since it was implemented in SQL Server for ages, you will find more information about it then Lateral.

Second, according to my understanding, there is nothing you can not do using subquery instead of using lateral. But:

Consider following query.

Select A.*
, (Select B.Column1 from B where B.Fk1 = A.PK and Limit 1)
, (Select B.Column2 from B where B.Fk1 = A.PK and Limit 1)
FROM A 

You can use lateral in this condition.

Select A.*
, x.Column1
, x.Column2
FROM A LEFT JOIN LATERAL (
  Select B.Column1,B.Column2,B.Fk1 from B  Limit 1
) x ON X.Fk1 = A.PK

In this query you can not use normal join, due to limit clause. Lateral or Cross Apply can be used when there is not simple join condition.

There are more usages for lateral or cross apply but this is most common one I found.

How to get form values in Symfony2 controller

If Symfony 4 or 5, juste use this code (Where name is the name of your field):

$request->request->get('name');

How to implement Rate It feature in Android App

Android’s new In-App Review system launched which lets developers ask for Play store reviews without leaving the app.

To check design guidelines and when to display a review card, refer to the official document

https://developer.android.com/guide/playcore/in-app-review

To implement:

  • Add play-core library as a dependency in your build.gradle file.
implementation 'com.google.android.play:core:1.8.0'
  • Create a ReviewManager instance and request ReviewInfo object. The ReviewInfo object to be pre-cached and then can trigger "launchReviewFlow" to present the Review card to the user.

     private var reviewInfo: ReviewInfo? = null
    
     val manager = ReviewManagerFactory.create(context)
    
     val request = manager.requestReviewFlow()
    
     requestFlow.addOnCompleteListener { request ->
         if (request.isSuccessful) {
             //Received ReviewInfo object
             reviewInfo = request.result
         } else {
             //Problem in receiving object
             reviewInfo = null
         }
    
     reviewInfo?.let {
         val flow = reviewManager.launchReviewFlow(this@MainActivity, it)
         flow.addOnCompleteListener {
             //Irrespective of the result, the app flow should continue
         }
     }
    

Note : It is suggested to show the review flow after the user has experienced enough of your app or game.

When to request an in-app review:

  • Trigger the in-app review flow after a user has experienced enough of your app or game to provide useful feedback.
  • Do not prompt the user excessively for a review. This approach helps minimize user frustration and limit API usage (see the section on quotas).
  • Your app should not ask the user any questions before or while presenting the rating button or card, including questions about their opinion (such as “Do you like the app?”) or predictive questions (such as “Would you rate this app 5 stars”).

Few points before testing this:

  • While testing new functionalities, mostly we create a new project that would have new ApplicationId, make sure you give an ApplicationId that is already released and available in the play store.

  • If you have given feedback in the past for your app, in-app review API’s launchReviewFlow will not present any Review card. It simply triggers a success event.

  • Due to quota limitations, calling a launchReviewFlow method might not always display a dialog. It should not be linked with any click event.

How to justify navbar-nav in Bootstrap 3

<div class="navbar navbar-default navbar-fixed-top" role="navigation">
 <div class="container">
<div class="navbar-header">
  <button type="button" class="navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
    <span class="sr-only">Toggle navigation</span>
    <span class="icon-bar"></span>
    <span class="icon-bar"></span>
    <span class="icon-bar"></span>
  </button>
</div>
<div class="collapse navbar-collapse">
  <ul class="nav navbar-nav">
    <li><a href="#">Home</a></li>
    <li><a href="#about">About</a></li>
    <li><a href="#contact">Contact</a></li>  
  </ul>
</div>

and for the css

@media ( min-width: 768px ) { 
    .navbar > .container {
        text-align: center;
    }
    .navbar-header,.navbar-brand,.navbar .navbar-nav,.navbar .navbar-nav > li {
        float: none;
        display: inline-block;
    }
    .collapse.navbar-collapse {
        width: auto;
        clear: none;
    }
}

see it live http://www.bootply.com/103172

Remote branch is not showing up in "git branch -r"

I had the same issue. It seems the easiest solution is to just remove the remote, readd it, and fetch.

Stacking DIVs on top of each other?

If you mean by literally putting one on the top of the other, one on the top (Same X, Y positions, but different Z position), try using the z-index CSS attribute. This should work (untested)

<div>
    <div style='z-index: 1'>1</div>
    <div style='z-index: 2'>2</div>
    <div style='z-index: 3'>3</div>
    <div style='z-index: 4'>4</div>
</div>

This should show 4 on the top of 3, 3 on the top of 2, and so on. The higher the z-index is, the higher the element is positioned on the z-axis. I hope this helped you :)

How to place Text and an Image next to each other in HTML?

You can use vertical-align and floating.

In most cases you want to vertical-align: middle, the image.

Here is a test: http://www.w3schools.com/cssref/tryit.asp?filename=trycss_vertical-align

vertical-align: baseline|length|sub|super|top|text-top|middle|bottom|text-bottom|initial|inherit;

For middle, the definition is: The element is placed in the middle of the parent element.

So you might want to apply that to all elements within the element.

SQL UPDATE with sub-query that references the same table in MySQL

Abstract example with clearer table and column names:

UPDATE tableName t1
INNER JOIN tableName t2 ON t2.ref_column = t1.ref_column
SET t1.column_to_update = t2.column_desired_value

As suggested by @Nico

Hope this help someone.

Remove an array element and shift the remaining ones

You can't achieve what you want with arrays. Use vectors instead, and read about the std::remove algorithm. Something like:

std::remove(array, array+5, 3)

will work on your array, but it will not shorten it (why -- because it's impossible). With vectors, it'd be something like

v.erase(std::remove(v.begin(), v.end(), 3), v.end())

How can I delete (not disable) ActiveX add-ons in Internet Explorer (7 and 8 Beta 2)?

Tools > Manage Add-ons, right click "Name" header and enable the "In Folder" section. go to the directory for the plugin you're interested in. Right click the plugin file, and click "remove".

How to convert JSON object to an Typescript array?

You have a JSON object that contains an Array. You need to access the array results. Change your code to:

this.data = res.json().results

Combine multiple JavaScript files into one JS file

This may be a bit of effort but you could download my open-source wiki project from codeplex:

http://shuttlewiki.codeplex.com

It contains a CompressJavascript project (and CompressCSS) that uses the http://yuicompressor.codeplex.com/ project.

The code should be self-explanatory but it makes combining and compressing the files a bit simnpler --- for me anyway :)

The ShuttleWiki project shows how to use it in the post-build event.

MySQL - force not to use cache for testing speed of query

One problem with the

SELECT SQL_NO_CACHE * FROM TABLE

method is that it seems to only prevent the result of your query from being cached. However, if you're querying a database that is actively being used with the query you want to test, then other clients may cache your query, affecting your results. I am continuing to research ways around this, will edit this post if I figure one out.

How do I use itertools.groupby()?

WARNING:

The syntax list(groupby(...)) won't work the way that you intend. It seems to destroy the internal iterator objects, so using

for x in list(groupby(range(10))):
    print(list(x[1]))

will produce:

[]
[]
[]
[]
[]
[]
[]
[]
[]
[9]

Instead, of list(groupby(...)), try [(k, list(g)) for k,g in groupby(...)], or if you use that syntax often,

def groupbylist(*args, **kwargs):
    return [(k, list(g)) for k, g in groupby(*args, **kwargs)]

and get access to the groupby functionality while avoiding those pesky (for small data) iterators all together.

Component is part of the declaration of 2 modules

Remove the declaration from AppModule, but update the AppModule configuration to import your AddEventModule.

.....
import { AddEventModule } from './add-event.module';  // <-- don't forget to import the AddEventModule class

@NgModule({
  declarations: [
    MyApp,
    HomePage,
    Login,
    Register,
    //AddEvent,  <--- remove this
    EventDetails

  ],
  imports: [
    BrowserModule,
    IonicModule.forRoot(MyApp),
    HttpModule,
    AngularFireModule.initializeApp(config),
    AddEventModule,  // <--- add this import here
  ],
  bootstrap: [IonicApp],
  entryComponents: [
    MyApp,
    HomePage,
    Login,
    Register,
    AddEvent,
    EventDetails
  ],
  providers: [
    StatusBar,
    SplashScreen,
    {provide: ErrorHandler, useClass: IonicErrorHandler}, Eventdata, AuthProvider
  ]
})
export class AppModule {}

Also,

Note that it's important that your AddEventModule exports the AddEvent component if you want to use it outside that module. Luckily, you already have that configured, but if it was omitted, you would've gotten an error if you tried to use the AddEvent component in another component of your AppModule

what is the use of Eval() in asp.net

While binding a databound control, you can evaluate a field of the row in your data source with eval() function.

For example you can add a column to your gridview like that :

<asp:BoundField DataField="YourFieldName" />

And alternatively, this is the way with eval :

<asp:TemplateField>
<ItemTemplate>
        <asp:Label ID="lbl" runat="server" Text='<%# Eval("YourFieldName") %>'>
        </asp:Label>
</ItemTemplate>
</asp:TemplateField>

It seems a little bit complex, but it's flexible, because you can set any property of the control with the eval() function :

<asp:TemplateField>
    <ItemTemplate>
        <asp:HyperLink ID="HyperLink1" runat="server" 
          NavigateUrl='<%# "ShowDetails.aspx?id="+Eval("Id") %>' 
          Text='<%# Eval("Text", "{0}") %>'></asp:HyperLink>
    </ItemTemplate>
</asp:TemplateField>

How can I stop Chrome from going into debug mode?

You've accidentally set "Pause on Exceptions" to all/uncaught exceptions.

Go to the "Sources" tab. At the bottom toolbar, toggle the button that looks like the pause symbol surrounded by a circle (4th button from the left) until the color of the circle turns black to turn it off.

C pass int array pointer as parameter into a function

main()
{
    int *arr[5];
    int i=31, j=5, k=19, l=71, m;

    arr[0]=&i;
    arr[1]=&j;
    arr[2]=&k;
    arr[3]=&l;
    arr[4]=&m;

    for(m=0; m<=4; m++)
    {
        printf("%d",*(arr[m]));
    }
    return 0;
}

.NET Out Of Memory Exception - Used 1.3GB but have 16GB installed

If you have 32-bit Windows, this method is not working without following settings.

  1. Run prompt cmd.exe (important : Run As Administrator)
  2. type bcdedit.exe and run
  3. Look at the "increaseuserva" params and there is no then write following statement
  4. bcdedit /set increaseuserva 3072
  5. and again step 2 and check params

We added this settings and this block started.

if exist "$(DevEnvDir)..\tools\vsvars32.bat" (
   call "$(DevEnvDir)..\tools\vsvars32.bat"
   editbin /largeaddressaware "$(TargetPath)"
)

More info - command increaseuserva: https://docs.microsoft.com/en-us/windows-hardware/drivers/devtest/bcdedit--set

Header set Access-Control-Allow-Origin in .htaccess doesn't work

I have a shared hosting on GoDaddy. I needed an answer to this question, too, and after searching around I found that it is possible.

I wrote an .htaccess file, put it in the same folder as my action page. Here are the contents of the .htaccess file:

Header add Access-Control-Allow-Origin "*"
Header add Access-Control-Allow-Headers "origin, x-requested-with, content-type"
Header add Access-Control-Allow-Methods "PUT, GET, POST, DELETE, OPTIONS"

Here is my ajax call:

    $.ajax({
        url: 'http://www.mydomain.com/myactionpagefolder/gbactionpage.php',  //server script to process data
        type: 'POST',
        xhr: function() {  // custom xhr
            myXhr = $.ajaxSettings.xhr();
            if(myXhr.upload){ // check if upload property exists
                myXhr.upload.addEventListener('progress',progressHandlingFunction, false); // for handling the progress of the upload
            }
            return myXhr;
        },
        //Ajax events
        beforeSend: beforeSendHandler,
        success: completeHandler,
        error: errorHandler,
        // Form data
        data: formData,
        //Options to tell JQuery not to process data or worry about content-type
        cache: false,
        contentType: false,
        processData: false
    });

See this article for reference:

Header set Access-Control-Allow-Origin in .htaccess doesn't work

Log4net does not write the log in the log file

Use this FAQ page: Apache log4net Frequently Asked Questions

About 3/4 of the way down it tells you how to enable log4net debugging by using application tracing. This will tell you where your issue is.

The basics are:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <appSettings>
        <add key="log4net.Internal.Debug" value="true"/>
    </appSettings>
</configuration>

And you see the trace in the standard output

How to set environment variable for everyone under my linux system?

As well as /etc/profile which others have mentioned, some Linux systems now use a directory /etc/profile.d/; any .sh files in there will be sourced by /etc/profile. It's slightly neater to keep your custom environment stuff in these files than to just edit /etc/profile.

Plot two histograms on single chart with matplotlib

Also an option which is quite similar to joaquin answer:

import random
from matplotlib import pyplot

#random data
x = [random.gauss(3,1) for _ in range(400)]
y = [random.gauss(4,2) for _ in range(400)]

#plot both histograms(range from -10 to 10), bins set to 100
pyplot.hist([x,y], bins= 100, range=[-10,10], alpha=0.5, label=['x', 'y'])
#plot legend
pyplot.legend(loc='upper right')
#show it
pyplot.show()

Gives the following output:

enter image description here

Rails: select unique values from a column

Model.select(:rating).distinct

Maven parent pom vs modules pom

In my opinion, to answer this question, you need to think in terms of project life cycle and version control. In other words, does the parent pom have its own life cycle i.e. can it be released separately of the other modules or not?

If the answer is yes (and this is the case of most projects that have been mentioned in the question or in comments), then the parent pom needs his own module from a VCS and from a Maven point of view and you'll end up with something like this at the VCS level:

root
|-- parent-pom
|   |-- branches
|   |-- tags
|   `-- trunk
|       `-- pom.xml
`-- projectA
    |-- branches
    |-- tags
    `-- trunk
        |-- module1
        |   `-- pom.xml
        |-- moduleN
        |   `-- pom.xml
        `-- pom.xml

This makes the checkout a bit painful and a common way to deal with that is to use svn:externals. For example, add a trunks directory:

root
|-- parent-pom
|   |-- branches
|   |-- tags
|   `-- trunk
|       `-- pom.xml
|-- projectA
|   |-- branches
|   |-- tags
|   `-- trunk
|       |-- module1
|       |   `-- pom.xml
|       |-- moduleN
|       |   `-- pom.xml
|       `-- pom.xml
`-- trunks

With the following externals definition:

parent-pom http://host/svn/parent-pom/trunk
projectA http://host/svn/projectA/trunk

A checkout of trunks would then result in the following local structure (pattern #2):

root/
  parent-pom/
    pom.xml
  projectA/

Optionally, you can even add a pom.xml in the trunks directory:

root
|-- parent-pom
|   |-- branches
|   |-- tags
|   `-- trunk
|       `-- pom.xml
|-- projectA
|   |-- branches
|   |-- tags
|   `-- trunk
|       |-- module1
|       |   `-- pom.xml
|       |-- moduleN
|       |   `-- pom.xml
|       `-- pom.xml
`-- trunks
    `-- pom.xml

This pom.xml is a kind of "fake" pom: it is never released, it doesn't contain a real version since this file is never released, it only contains a list of modules. With this file, a checkout would result in this structure (pattern #3):

root/
  parent-pom/
    pom.xml
  projectA/
  pom.xml

This "hack" allows to launch of a reactor build from the root after a checkout and make things even more handy. Actually, this is how I like to setup maven projects and a VCS repository for large builds: it just works, it scales well, it gives all the flexibility you may need.

If the answer is no (back to the initial question), then I think you can live with pattern #1 (do the simplest thing that could possibly work).

Now, about the bonus questions:

  • Where is the best place to define the various shared configuration as in source control, deployment directories, common plugins etc. (I'm assuming the parent but I've often been bitten by this and they've ended up in each project rather than a common one).

Honestly, I don't know how to not give a general answer here (like "use the level at which you think it makes sense to mutualize things"). And anyway, child poms can always override inherited settings.

  • How do the maven-release plugin, hudson and nexus deal with how you set up your multi-projects (possibly a giant question, it's more if anyone has been caught out when by how a multi-project build has been set up)?

The setup I use works well, nothing particular to mention.

Actually, I wonder how the maven-release-plugin deals with pattern #1 (especially with the <parent> section since you can't have SNAPSHOT dependencies at release time). This sounds like a chicken or egg problem but I just can't remember if it works and was too lazy to test it.

With CSS, how do I make an image span the full width of the page as a background image?

If you're hoping to use background-image: url(...);, I don't think you can. However, if you want to play with layering, you can do something like this:

<img class="bg" src="..." />

And then some CSS:

.bg
{
  width: 100%;
  z-index: 0;
}

You can now layer content above the stretched image by playing with z-indexes and such. One quick note, the image can't be contained in any other elements for the width: 100%; to apply to the whole page.

Here's a quick demo if you can't rely on background-size: http://jsfiddle.net/bB3Uc/

update listview dynamically with adapter

Use a ArrayAdapter backed by an ArrayList. To change the data, just update the data in the list and call adapter.notifyDataSetChanged().

How can I do an UPDATE statement with JOIN in SQL Server?

Try this one, I think this will works for you

update ud

set ud.assid = sale.assid

from ud 

Inner join sale on ud.id = sale.udid

where sale.udid is not null

Logcat not displaying my log calls

Probably it's not be correct, and a little bit longer, but I solved this problem (Android Studio) by using this:

System.out.println("Some text here");

Like this:

try {
       ...code here...
} catch(Exception e) {
  System.out.println("Error desc: " + e.getMessage());
}

Bootstrap 3 jquery event for active tab change

I use another approach.

Just try to find all a where id starts from some substring.

JS

$('a[id^=v-photos-tab]').click(function () {
     alert("Handler for .click() called.");
});

HTML

<a class="nav-item nav-link active show"  id="v-photos-tab-3a623245-7dc7-4a22-90d0-62705ad0c62b" data-toggle="pill" href="#v-photos-3a623245-7dc7-4a22-90d0-62705ad0c62b" role="tab" aria-controls="v-requestbase-photos" aria-selected="true"><span>Cool photos</span></a>

How to delete row in gridview using rowdeleting event?

protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
    GridViewRow row = (GridViewRow)GridView1.Rows[e.RowIndex];
    SqlCommand cmd = new SqlCommand("Delete From userTable (userName,age,birthPLace)");
    GridView1.DataBind();
}

Dynamic SQL results into temp table in SQL Stored procedure

create a global temp table with a GUID in the name dynamically. Then you can work with it in your code, via dyn sql, without worry that another process calling same sproc will use it. This is useful when you dont know what to expect from the underlying selected table each time it runs so you cannot created a temp table explicitly beforehand. ie - you need to use SELECT * INTO syntax

DECLARE @TmpGlobalTable varchar(255) = 'SomeText_' + convert(varchar(36),NEWID())

-- select @TmpGlobalTable 

-- build query
    SET @Sql = 
        'SELECT * INTO [##' + @TmpGlobalTable + '] FROM SomeTable'
EXEC (@Sql)
EXEC ('SELECT * FROM [##' + @TmpGlobalTable + '] ')
EXEC ('DROP TABLE [##' + @TmpGlobalTable + ']')
PRINT 'Dropped Table ' + @TmpGlobalTable 

How to delete a file from SD card?

Recursively delete all children of the file ...

public static void DeleteRecursive(File fileOrDirectory) {
    if (fileOrDirectory.isDirectory()) {
        for (File child : fileOrDirectory.listFiles()) {
            DeleteRecursive(child);
        }
    }

    fileOrDirectory.delete();
}

What is MVC and what are the advantages of it?

One con I can think of is if you need really fast access to your data in your view (for example, game animation data like bone positions.) It is very inefficient to keep a layer of separation in this case.

Otherwise, for most other applications which are more data driven than graphics driven, it seems like a logical way to drive a UI.

How can I change the text color with jQuery?

Nowadays, animating text color is included in the jQuery UI Effects Core. It's pretty small. You can make a custom download here: http://jqueryui.com/download - but you don't actually need anything but the effects core itself (not even the UI core), and it brings with it different easing functions as well.

jQuery add class .active on menu

Setting the active menu, they have the many ways to do that. Now, I share you a way to set active menu by CSS.

    <a href="index.php?id=home">Home</a>
    <a href="index.php?id=news">News</a>
    <a href="index.php?id=about">About</a>

Now, you only set $_request["id"] == "home" thì echo "class='active'" , then we can do same with others.

<a href="index.php?id=home" <?php if($_REQUEST["id"]=="home"){echo "class='active'";}?>>Home</a>
<a href="index.php?id=news" <?php if($_REQUEST["id"]=="news"){echo "class='active'";}?>>News</a>
<a href="index.php?id=about" <?php if($_REQUEST["id"]=="about"){echo "class='active'";}?>>About</a>

I think it is useful with you.

How can I use a batch file to write to a text file?

You can use echo, and redirect the output to a text file (see notes below):

rem Saved in D:\Temp\WriteText.bat
@echo off
echo This is a test> test.txt
echo 123>> test.txt
echo 245.67>> test.txt

Output:

D:\Temp>WriteText

D:\Temp>type test.txt
This is a test
123
245.67

D:\Temp>

Notes:

  • @echo off turns off printing of each command to the console
  • Unless you give it a specific path name, redirection with > or >> will write to the current directory (the directory the code is being run in).
  • The echo This is a test > test.txt uses one > to overwrite any file that already exists with new content.
  • The remaining echo statements use two >> characters to append to the text file (add to), instead of overwriting it.
  • The type test.txt simply types the file output to the command window.

how to parse json using groovy

        def jsonFile = new File('File Path');
        JsonSlurper jsonSlurper = new JsonSlurper();
        def parseJson = jsonSlurper.parse(jsonFile)
        String json = JsonOutput.toJson(parseJson)
        def prettyJson = JsonOutput.prettyPrint(json)
        println(prettyJson)

OR, AND Operator

if(A == "haha" && B == "hihi") {
//hahahihi?
}

if(A == "haha" || B != "hihi") {
//hahahihi!?
}

Angular-cli from css to scss

Open angular.json file

1.change from

"schematics": {}

to

"schematics": {
           "@schematics/angular:component": {
                   "styleext": "scss"       
             }  
  }
  1. change from (at two places)

"src/styles.css"

to

"src/styles.scss"

then check and rename all .css files and update component.ts files styleUrls from .css to .scss

Printing object properties in Powershell

Some general notes.


$obj | Select-Object ? $obj | Select-Object -Property *

The latter will show all non-intrinsic, non-compiler-generated properties. The former does not appear to (always) show all Property types (in my tests, it does appear to show the CodeProperty MemberType consistently though -- no guarantees here).


Some switches to be aware of for Get-Member

  • Get-Member does not get static members by default. You also cannot (directly) get them along with the non-static members. That is, using the switch causes only static members to be returned:

    PS Y:\Power> $obj | Get-Member -Static
    
       TypeName: System.IsFire.TurnUpProtocol
    
    Name        MemberType Definition
    ----        ---------- ----------
    Equals      Method     static bool Equals(System.Object objA, System.Object objB)
    ...
    
  • Use the -Force.

    The Get-Member command uses the Force parameter to add the intrinsic members and compiler-generated members of the objects to the display. Get-Member gets these members, but it hides them by default.

    PS Y:\Power> $obj | Get-Member -Static
    
       TypeName: System.IsFire.TurnUpProtocol
    
    Name          MemberType     Definition
    ----          ----------     ----------
    ...
    pstypenames   CodeProperty   System.Collections.ObjectModel.Collection...
    psadapted     MemberSet      psadapted {AccessRightType, AccessRuleType,...
    ...
    

Use ConvertTo-Json for depth and readable "serialization"

I do not necessary recommend saving objects using JSON (use Export-Clixml instead). However, you can get a more or less readable output from ConvertTo-Json, which also allows you to specify depth.

Note that not specifying Depth implies -Depth 2

PS Y:\Power> ConvertTo-Json $obj -Depth 1
{
    "AllowSystemOverload":  true,
    "AllowLifeToGetInTheWay":  false,
    "CantAnyMore": true,
    "LastResortOnly": true,
...

And if you aren't planning to read it you can -Compress it (i.e. strip whitespace)

PS Y:\Power> ConvertTo-Json $obj -Depth 420 -Compress

Use -InputObject if you can (and are willing)

99.9% of the time when using PowerShell: either the performance won't matter, or you don't care about the performance. However, it should be noted that avoiding the pipe when you don't need it can save some overhead and add some speed (piping, in general, is not super-efficient).

That is, if you all you have is a single $obj handy for printing (and aren't too lazy like me sometimes to type out -InputObject):

# select is aliased (hardcoded) to Select-Object
PS Y:\Power> select -Property * -InputObject $obj
# gm is aliased (hardcoded) to Get-Member
PS Y:\Power> gm -Force -InputObject $obj

Caveat for Get-Member -InputObject: If $obj is a collection (e.g. System.Object[]), You end up getting information about the collection object itself:

PS Y:\Power> gm -InputObject $obj,$obj2
   TypeName: System.Object[]

Name        MemberType            Definition
----        ----------            ----------
Count       AliasProperty         Count = Length
...

If you want to Get-Member for each TypeName in the collection (N.B. for each TypeName, not for each object--a collection of N objects with all the same TypeName will only print 1 table for that TypeName, not N tables for each object)......just stick with piping it in directly.

How can I run PowerShell with the .NET 4 runtime?

The other answers are from before 2012, and they focus on "hacking" PowerShell 1.0 or PowerShell 2.0 into targeting newer versions of the .NET Framework and Common Language Runtime (CLR).

However, as has been written in many comments, since 2012 (when PowerShell 3.0 came) a much better solution is to install the newest version of PowerShell. It will automatically target CLR v4.0.30319. This means .NET 4.0, 4.5, 4.5.1, 4.5.2, or 4.6 (expected in 2015) since all of these versions are in-place replacements of each other. Use $PSVersionTable or see the Determine installed PowerShell version thread if you are unsure of your PowerShell version.

At the time of writing, the newest version of PowerShell is 4.0, and it can be downloaded with the Windows Management Framework (Google search link).

SQL Server: Invalid Column Name

I had a similar problem.

Issue was there was a trigger on the table that would write changes to an audit log table. Columns were missing in audit log table.

string encoding and decoding?

Aside from getting decode and encode backwards, I think part of the answer here is actually don't use the ascii encoding. It's probably not what you want.

To begin with, think of str like you would a plain text file. It's just a bunch of bytes with no encoding actually attached to it. How it's interpreted is up to whatever piece of code is reading it. If you don't know what this paragraph is talking about, go read Joel's The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets right now before you go any further.

Naturally, we're all aware of the mess that created. The answer is to, at least within memory, have a standard encoding for all strings. That's where unicode comes in. I'm having trouble tracking down exactly what encoding Python uses internally for sure, but it doesn't really matter just for this. The point is that you know it's a sequence of bytes that are interpreted a certain way. So you only need to think about the characters themselves, and not the bytes.

The problem is that in practice, you run into both. Some libraries give you a str, and some expect a str. Certainly that makes sense whenever you're streaming a series of bytes (such as to or from disk or over a web request). So you need to be able to translate back and forth.

Enter codecs: it's the translation library between these two data types. You use encode to generate a sequence of bytes (str) from a text string (unicode), and you use decode to get a text string (unicode) from a sequence of bytes (str).

For example:

>>> s = "I look like a string, but I'm actually a sequence of bytes. \xe2\x9d\xa4"
>>> codecs.decode(s, 'utf-8')
u"I look like a string, but I'm actually a sequence of bytes. \u2764"

What happened here? I gave Python a sequence of bytes, and then I told it, "Give me the unicode version of this, given that this sequence of bytes is in 'utf-8'." It did as I asked, and those bytes (a heart character) are now treated as a whole, represented by their Unicode codepoint.

Let's go the other way around:

>>> u = u"I'm a string! Really! \u2764"
>>> codecs.encode(u, 'utf-8')
"I'm a string! Really! \xe2\x9d\xa4"

I gave Python a Unicode string, and I asked it to translate the string into a sequence of bytes using the 'utf-8' encoding. So it did, and now the heart is just a bunch of bytes it can't print as ASCII; so it shows me the hexadecimal instead.

We can work with other encodings, too, of course:

>>> s = "I have a section \xa7"
>>> codecs.decode(s, 'latin1')
u'I have a section \xa7'
>>> codecs.decode(s, 'latin1')[-1] == u'\u00A7'
True

>>> u = u"I have a section \u00a7"
>>> u
u'I have a section \xa7'
>>> codecs.encode(u, 'latin1')
'I have a section \xa7'

('\xa7' is the section character, in both Unicode and Latin-1.)

So for your question, you first need to figure out what encoding your str is in.

  • Did it come from a file? From a web request? From your database? Then the source determines the encoding. Find out the encoding of the source and use that to translate it into a unicode.

    s = [get from external source]
    u = codecs.decode(s, 'utf-8') # Replace utf-8 with the actual input encoding
    
  • Or maybe you're trying to write it out somewhere. What encoding does the destination expect? Use that to translate it into a str. UTF-8 is a good choice for plain text documents; most things can read it.

    u = u'My string'
    s = codecs.encode(u, 'utf-8') # Replace utf-8 with the actual output encoding
    [Write s out somewhere]
    
  • Are you just translating back and forth in memory for interoperability or something? Then just pick an encoding and stick with it; 'utf-8' is probably the best choice for that:

    u = u'My string'
    s = codecs.encode(u, 'utf-8')
    newu = codecs.decode(s, 'utf-8')
    

In modern programming, you probably never want to use the 'ascii' encoding for any of this. It's an extremely small subset of all possible characters, and no system I know of uses it by default or anything.

Python 3 does its best to make this immensely clearer simply by changing the names. In Python 3, str was replaced with bytes, and unicode was replaced with str.

How to break out of a loop from inside a switch?

A neatish way to do this would be to put this into a function:

int yourfunc() {

    while(true) {

        switch(msg->state) {
        case MSGTYPE: // ... 
            break;
        // ... more stuff ...
        case DONE:
            return; 
        }

    }
}

Optionally (but 'bad practices'): as already suggested you could use a goto, or throw an exception inside the switch.

Python Inverse of a Matrix

For those like me, who were looking for a pure Python solution without pandas or numpy involved, check out the following GitHub project: https://github.com/ThomIves/MatrixInverse.

It generously provides a very good explanation of how the process looks like "behind the scenes". The author has nicely described the step-by-step approach and presented some practical examples, all easy to follow.

This is just a little code snippet from there to illustrate the approach very briefly (AM is the source matrix, IM is the identity matrix of the same size):

def invert_matrix(AM, IM):
    for fd in range(len(AM)):
        fdScaler = 1.0 / AM[fd][fd]
        for j in range(len(AM)):
            AM[fd][j] *= fdScaler
            IM[fd][j] *= fdScaler
        for i in list(range(len(AM)))[0:fd] + list(range(len(AM)))[fd+1:]:
            crScaler = AM[i][fd]
            for j in range(len(AM)):
                AM[i][j] = AM[i][j] - crScaler * AM[fd][j]
                IM[i][j] = IM[i][j] - crScaler * IM[fd][j]
    return IM

But please do follow the entire thing, you'll learn a lot more than just copy-pasting this code! There's a Jupyter notebook as well, btw.

Hope that helps someone, I personally found it extremely useful for my very particular task (Absorbing Markov Chain) where I wasn't able to use any non-standard packages.

Vertical Align Center in Bootstrap 4

<div class="row">
  <div class="col-md-6">
     <img src="/assets/images/ebook2.png" alt="" class="img-fluid">
  </div>
  <div class="col-md-6 my-auto">
     <h3>Heading</h3>
     <p>Some text.</p>
   </div>
</div>

This line is where the magic happens <div class="col-md-6 my-auto">, the my-auto will center the content of the column. This works great with situations like the code sample above where you might have a variable sized image and need to have the text in the column to the right line up with it.

Sum of Numbers C++

You are just updating the value of i in the loop. The value of i should also be added each time.

It is never a good idea to update the value of i inside the for loop. The for loop index should only be used as a counter. In your case, changing the value of i inside the loop will cause all sorts of confusion.

Create variable total that holds the sum of the numbers up to i.

So

 for (int i = 0; i < positiveInteger; i++)
        total += i;

How do I separate an integer into separate digits in an array in JavaScript?

let input = 12345664
const output = []
while (input !== 0) {
  const roundedInput = Math.floor(input / 10)
  output.push(input - roundedInput * 10)
  input = roundedInput
}
console.log(output)

How to mark a build unstable in Jenkins when running shell scripts

It can be done without printing magic strings and using TextFinder. Here's some info on it.

Basically you need a .jar file from http://yourserver.com/cli available in shell scripts, then you can use the following command to mark a build unstable:

java -jar jenkins-cli.jar set-build-result unstable

To mark build unstable on error, you can use:

failing_cmd cmd_args || java -jar jenkins-cli.jar set-build-result unstable

The problem is that jenkins-cli.jar has to be available from shell script. You can either put it in easy-to-access path, or download in via job's shell script:

wget ${JENKINS_URL}jnlpJars/jenkins-cli.jar

Get Substring - everything before certain char

The LINQy way

String.Concat( "223232-1.jpg".TakeWhile(c => c != '-') )

(But, you do need to test for null ;)

How to compile .c file with OpenSSL includes?

Use the -I flag to gcc properly.

gcc -I/path/to/openssl/ -o Opentest -lcrypto Opentest.c

The -I should point to the directory containing the openssl folder.

making matplotlib scatter plots from dataframes in Python's pandas

Try passing columns of the DataFrame directly to matplotlib, as in the examples below, instead of extracting them as numpy arrays.

df = pd.DataFrame(np.random.randn(10,2), columns=['col1','col2'])
df['col3'] = np.arange(len(df))**2 * 100 + 100

In [5]: df
Out[5]: 
       col1      col2  col3
0 -1.000075 -0.759910   100
1  0.510382  0.972615   200
2  1.872067 -0.731010   500
3  0.131612  1.075142  1000
4  1.497820  0.237024  1700

Vary scatter point size based on another column

plt.scatter(df.col1, df.col2, s=df.col3)
# OR (with pandas 0.13 and up)
df.plot(kind='scatter', x='col1', y='col2', s=df.col3)

enter image description here

Vary scatter point color based on another column

colors = np.where(df.col3 > 300, 'r', 'k')
plt.scatter(df.col1, df.col2, s=120, c=colors)
# OR (with pandas 0.13 and up)
df.plot(kind='scatter', x='col1', y='col2', s=120, c=colors)

enter image description here

Scatter plot with legend

However, the easiest way I've found to create a scatter plot with legend is to call plt.scatter once for each point type.

cond = df.col3 > 300
subset_a = df[cond].dropna()
subset_b = df[~cond].dropna()
plt.scatter(subset_a.col1, subset_a.col2, s=120, c='b', label='col3 > 300')
plt.scatter(subset_b.col1, subset_b.col2, s=60, c='r', label='col3 <= 300') 
plt.legend()

enter image description here

Update

From what I can tell, matplotlib simply skips points with NA x/y coordinates or NA style settings (e.g., color/size). To find points skipped due to NA, try the isnull method: df[df.col3.isnull()]

To split a list of points into many types, take a look at numpy select, which is a vectorized if-then-else implementation and accepts an optional default value. For example:

df['subset'] = np.select([df.col3 < 150, df.col3 < 400, df.col3 < 600],
                         [0, 1, 2], -1)
for color, label in zip('bgrm', [0, 1, 2, -1]):
    subset = df[df.subset == label]
    plt.scatter(subset.col1, subset.col2, s=120, c=color, label=str(label))
plt.legend()

enter image description here

PowerShell equivalent to grep -f

I'm not familiar with grep but with Select-String you can do:

Get-ChildItem filename.txt | Select-String -Pattern <regexPattern>

You can also do that with Get-Content:

(Get-Content filename.txt) -match 'pattern'

Best practice when adding whitespace in JSX

You can use curly braces like expression with both double quotes and single quotes for space i.e.,

{" "} or {' '}

You can also use ES6 template literals i.e.,

`   <li></li>` or `  ${value}`

You can also use &nbsp like below (inside span)

<span>sample text &nbsp; </span>

You can also use &nbsp in dangerouslySetInnerHTML when printing html content

<div dangerouslySetInnerHTML={{__html: 'sample html text: &nbsp;'}} />

How to define a circle shape in an Android XML drawable file?

This is a simple circle as a drawable in Android.

<?xml version="1.0" encoding="utf-8"?>
<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">

   <solid 
       android:color="#666666"/>

   <size 
       android:width="120dp"
        android:height="120dp"/>
</shape>

How to update/modify an XML file in python?

You should read the XML file using specific XML modules. That way you can edit the XML document in memory and rewrite your changed XML document into the file.

Here is a quick start: http://docs.python.org/library/xml.dom.minidom.html

There are a lot of other XML utilities, which one is best depends on the nature of your XML file and in which way you want to edit it.

SSH to Vagrant box in Windows?

I use vagrant ssh command with git ssh on windows 7, 8.1 and Windows 10.

To install only download msysgit from msysgit project page.

And to run ssh.exe only include the bin folter to windows environment variables or install git from Git Download page and copy the msysgit bin folter to C:\Program Files\Git\bin.

How to check if function exists in JavaScript?

// just pass your tested function name instead of myFunctionName
if ( $.isFunction($.fn.myFunctionName) ) {
    console.log( 'write your code here.' );
}

POST Content-Length exceeds the limit

Try pasting this to .htaccess and it should work.

php_value post_max_size 2000M
php_value upload_max_filesize 2500M
php_value max_execution_time 6000000
php_value max_input_time 6000000
php_value memory_limit 2500M

Make Adobe fonts work with CSS3 @font-face in IE9

If you want to do this with a PHP script instead of having to run C code (or you're on a Mac like me and you can't be arsed compiling with Xcode only to wait a year for it to open), here's a PHP function that you can use to remove the embedding permissions from the font:

function convertRestrictedFont($filename) {
    $font = fopen($filename,'r+');
    if ($font === false) {
        throw new Exception('Could not open font file.');
    }

    fseek($font, 12, 0);

    while (!feof($font)) {
        $type = '';
        for ($i = 0; $i < 4; $i++) {
            $type .= fgetc($font);
            if (feof($font)) {
                fclose($font);
                throw new Exception('Could not read the table definitions of the font.');
            }
        }
        if ($type == 'OS/2') {
            // Save the location of the table definition
            // containing the checksum and pointer to the data
            $os2TableDefinition = ftell($font);
            $checksum = 0;

            for ($i = 0; $i < 4; $i++) {
                fgetc($font);
                if (feof($font)) {
                    fclose($font);
                    throw new Exception('Could not read the OS/2 table header of the font.');
                }
            }

            // Get the pointer to the OS/2 table data
            $os2TablePointer = ord(fgetc($font)) << 24;
            $os2TablePointer |= ord(fgetc($font)) << 16;
            $os2TablePointer |= ord(fgetc($font)) << 8;
            $os2TablePointer |= ord(fgetc($font));

            $length = ord(fgetc($font)) << 24;
            $length |= ord(fgetc($font)) << 16;
            $length |= ord(fgetc($font)) << 8;
            $length |= ord(fgetc($font));

            if (fseek($font, $os2TablePointer + 8, 0) !== 0) {
                fclose($font);
                throw new Exception('Could not read the embeddable type of the font.');
            }

            // Read the fsType before overriding it
            $fsType = ord(fgetc($font)) << 8;
            $fsType |= ord(fgetc($font));

            error_log('Installable Embedding: ' . ($fsType == 0));
            error_log('Reserved: ' . ($fsType & 1));
            error_log('Restricted License: ' . ($fsType & 2));
            error_log('Preview & Print: ' . ($fsType & 4));
            error_log('Editable Embedding: ' . ($fsType & 8));
            error_log('Reserved: ' . ($fsType & 16)); 
            error_log('Reserved: ' . ($fsType & 32));
            error_log('Reserved: ' . ($fsType & 64));
            error_log('Reserved: ' . ($fsType & 128));
            error_log('No subsetting: ' . ($fsType & 256));
            error_log('Bitmap embedding only: ' . ($fsType & 512));                         
            error_log('Reserved: ' . ($fsType & 1024));
            error_log('Reserved: ' . ($fsType & 2048));
            error_log('Reserved: ' . ($fsType & 4096));
            error_log('Reserved: ' . ($fsType & 8192));
            error_log('Reserved: ' . ($fsType & 16384));
            error_log('Reserved: ' . ($fsType & 32768));

            fseek($font, ftell($font) - 2);

            // Set the two bytes of fsType to 0
            fputs($font, chr(0), 1);
            fputs($font, chr(0), 1);

            // Go to the beginning of the OS/2 table data
            fseek($font, $os2TablePointer, 0);

            // Generate a new checksum based on the changed 
            for ($i = 0; $i < $length; $i++) {
                $checksum += ord(fgetc($font));
            }
            fseek($font, $os2TableDefinition, 0);
            fputs($font, chr($checksum >> 24), 1);
            fputs($font, chr(255 & ($checksum >> 16)), 1);
            fputs($font, chr(255 & ($checksum >> 8)), 1);
            fputs($font, chr(255 & $checksum), 1);

            fclose($font);

            return true;
        }
        for ($i = 0; $i < 12; $i++) {
            fgetc($font);
            if (feof($font)) {
                fclose($font);
                throw new Exception('Could not skip a table definition of the font.');
            }
        }
    }

    fclose($font);

    return false;
}

Make sure to backup your font file before running this code and don't blame me if it corrupts.

Original source in C can be found here.

How to detect simple geometric shapes using OpenCV

The answer depends on the presence of other shapes, level of noise if any and invariance you want to provide for (e.g. rotation, scaling, etc). These requirements will define not only the algorithm but also required pre-procesing stages to extract features.

Template matching that was suggested above works well when shapes aren't rotated or scaled and when there are no similar shapes around; in other words, it finds a best translation in the image where template is located:

double minVal, maxVal;
Point minLoc, maxLoc;
Mat image, template, result; // template is your shape
matchTemplate(image, template, result, CV_TM_CCOEFF_NORMED);
minMaxLoc(result, &minVal, &maxVal, &minLoc, &maxLoc); // maxLoc is answer

Geometric hashing is a good method to get invariance in terms of rotation and scaling; this method would require extraction of some contour points.

Generalized Hough transform can take care of invariance, noise and would have minimal pre-processing but it is a bit harder to implement than other methods. OpenCV has such transforms for lines and circles.

In the case when number of shapes is limited calculating moments or counting convex hull vertices may be the easiest solution: openCV structural analysis

Why can't I set text to an Android TextView?

Or you can do this way :

((TextView)findViewById(R.id.this_is_the_id_of_textview)).setText("Test");

How to do vlookup and fill down (like in Excel) in R?

You could use mapvalues() from the plyr package.

Initial data:

dat <- data.frame(HouseType = c("Semi", "Single", "Row", "Single", "Apartment", "Apartment", "Row"))

> dat
  HouseType
1      Semi
2    Single
3       Row
4    Single
5 Apartment
6 Apartment
7       Row

Lookup / crosswalk table:

lookup <- data.frame(type_text = c("Semi", "Single", "Row", "Apartment"), type_num = c(1, 2, 3, 4))
> lookup
  type_text type_num
1      Semi        1
2    Single        2
3       Row        3
4 Apartment        4

Create the new variable:

dat$house_type_num <- plyr::mapvalues(dat$HouseType, from = lookup$type_text, to = lookup$type_num)

Or for simple replacements you can skip creating a long lookup table and do this directly in one step:

dat$house_type_num <- plyr::mapvalues(dat$HouseType,
                                      from = c("Semi", "Single", "Row", "Apartment"),
                                      to = c(1, 2, 3, 4))

Result:

> dat
  HouseType house_type_num
1      Semi              1
2    Single              2
3       Row              3
4    Single              2
5 Apartment              4
6 Apartment              4
7       Row              3

Spring Could not Resolve placeholder

in my case, the war file generated didn't pick up the properties file so had to clean install again in IntelliJ editor.

Extract substring from a string

substring():

str.substring(startIndex, endIndex); 

Calculate the mean by group

aggregate(speed~dive,data=df,FUN=mean)
   dive     speed
1 dive1 0.7059729
2 dive2 0.5473777

Passing arguments forward to another javascript function

try this

function global_func(...args){
  for(let i of args){
    console.log(i)
  }
}


global_func('task_name', 'action', [{x: 'x'},{x: 'x'}], {x: 'x'}, ['x1','x2'], 1, null, undefined, false, true)




//task_name
//action
//(2) [{...},
//    {...}]
//    {
//        x:"x"
//    }
//(2) [
//        "x1",
//        "x2"
//    ]
//1
//null
//undefined
//false
//true
//func

How to stop a function

A simple return statement will 'stop' or return the function; in precise terms, it 'returns' function execution to the point at which the function was called - the function is terminated without further action.

That means you could have a number of places throughout your function where it might return. Like this:

def player():
    # do something here
    check_winner_variable = check_winner()  # check something 
    if check_winner_variable == '1': 
        return
    second_test_variable = second_test()
    if second_test_variable == '1': 
        return
       
    # let the computer do something
    computer()

How do you upload a file to a document library in sharepoint?

With SharePoint 2013 new library, I managed to do something like this:

private void UploadToSharePoint(string p, out string newUrl)  //p is path to file to load
{
    string siteUrl = "https://myCompany.sharepoint.com/site/";
    //Insert Credentials
    ClientContext context = new ClientContext(siteUrl);

    SecureString passWord = new SecureString();
    foreach (var c in "mypassword") passWord.AppendChar(c);
    context.Credentials = new SharePointOnlineCredentials("myUserName", passWord);
    Web site = context.Web;

    //Get the required RootFolder
    string barRootFolderRelativeUrl = "Shared Documents/foo/bar";
    Folder barFolder = site.GetFolderByServerRelativeUrl(barRootFolderRelativeUrl);

    //Create new subFolder to load files into
    string newFolderName = baseName + DateTime.Now.ToString("yyyyMMddHHmm");
    barFolder.Folders.Add(newFolderName);
    barFolder.Update();

    //Add file to new Folder
    Folder currentRunFolder = site.GetFolderByServerRelativeUrl(barRootFolderRelativeUrl + "/" + newFolderName);
    FileCreationInformation newFile = new FileCreationInformation { Content = System.IO.File.ReadAllBytes(@p), Url = Path.GetFileName(@p), Overwrite = true };
    currentRunFolder.Files.Add(newFile);
    currentRunFolder.Update();

    context.ExecuteQuery();

    //Return the URL of the new uploaded file
    newUrl = siteUrl + barRootFolderRelativeUrl + "/" + newFolderName + "/" + Path.GetFileName(@p);
}

Dynamically adding HTML form field using jQuery

This will insert a new element after the input field with id "password".

$(document).ready(function(){
  var newInput = $("<input name='new_field' type='text'>");
  $('input#password').after(newInput);
});

Not sure if this answers your question.

-XX:MaxPermSize with or without -XX:PermSize

If you're doing some performance tuning it's often recommended to set both -XX:PermSize and -XX:MaxPermSize to the same value to increase JVM efficiency.

Here is some information:

  1. Support for large page heap on x86 and amd64 platforms
  2. Java Support for Large Memory Pages
  3. Setting the Permanent Generation Size

You can also specify -XX:+CMSClassUnloadingEnabled to enable class unloading option if you are using CMS GC. It may help to decrease the probability of Java.lang.OutOfMemoryError: PermGen space

Executing periodic actions in Python

Simply sleeping for 10 seconds or using threading.Timer(10,foo) will result in start time drift. (You may not care about this, or it may be a significant source of problems depending on your exact situation.) There can be two causes for this - inaccuracies in the wake up time of your thread or execution time for your function.

You can see some results at the end of this post, but first an example of how to fix it. You need to track when your function should next be called as opposed to when it actually got called and account for the difference.

Here's a version that drifts slightly:

import datetime, threading

def foo():
    print datetime.datetime.now()
    threading.Timer(1, foo).start()

foo()

Its output looks like this:

2013-08-12 13:05:36.483580
2013-08-12 13:05:37.484931
2013-08-12 13:05:38.485505
2013-08-12 13:05:39.486945
2013-08-12 13:05:40.488386
2013-08-12 13:05:41.489819
2013-08-12 13:05:42.491202
2013-08-12 13:05:43.492486
2013-08-12 13:05:44.493865
2013-08-12 13:05:45.494987
2013-08-12 13:05:46.496479
2013-08-12 13:05:47.497824
2013-08-12 13:05:48.499286
2013-08-12 13:05:49.500232

You can see that the sub-second count is constantly increasing and thus, the start time is "drifting".

This is code that correctly accounts for drift:

import datetime, threading, time

next_call = time.time()

def foo():
  global next_call
  print datetime.datetime.now()
  next_call = next_call+1
  threading.Timer( next_call - time.time(), foo ).start()

foo()

Its output looks like this:

2013-08-12 13:21:45.292565
2013-08-12 13:21:47.293000
2013-08-12 13:21:48.293939
2013-08-12 13:21:49.293327
2013-08-12 13:21:50.293883
2013-08-12 13:21:51.293070
2013-08-12 13:21:52.293393

Here you can see that there is no longer any increase in the sub-second times.

If your events are occurring really frequently you may want to run the timer in a single thread, rather than starting a new thread for each event. While accounting for drift this would look like:

import datetime, threading, time

def foo():
    next_call = time.time()
    while True:
        print datetime.datetime.now()
        next_call = next_call+1;
        time.sleep(next_call - time.time())

timerThread = threading.Thread(target=foo)
timerThread.start()

However your application will not exit normally, you'll need to kill the timer thread. If you want to exit normally when your application is done, without manually killing the thread, you should use

timerThread = threading.Thread(target=foo)
timerThread.daemon = True
timerThread.start()

Maven error: Not authorized, ReasonPhrase:Unauthorized

I have recently encountered this problem. Here are the steps to resolve

  1. Check the servers section in the settings.xml file.Is username and password correct?

_x000D_
_x000D_
<servers>_x000D_
  <server>_x000D_
    <id>serverId</id>_x000D_
    <username>username</username>_x000D_
    <password>password</password>_x000D_
  </server>_x000D_
</servers>
_x000D_
_x000D_
_x000D_

  1. Check the repository section in the pom.xml file.The id of the server tag should be the same as the id of the repository tag.

_x000D_
_x000D_
<repositories>_x000D_
 <repository>_x000D_
   <id>serverId</id>  _x000D_
   <url>http://maven.aliyun.com/nexus/content/groups/public/</url>_x000D_
 </repository>_x000D_
</repositories>
_x000D_
_x000D_
_x000D_

  1. If the repository tag is not configured in the pom.xml file, look in the settings.xml file.

_x000D_
_x000D_
<profiles>_x000D_
 <profile>_x000D_
   <repositories>_x000D_
     <repository>_x000D_
      <id>serverId</id>_x000D_
      <name>aliyun</name>_x000D_
      <url>http://maven.aliyun.com/nexus/content/groups/public/</url>_x000D_
     </repository>_x000D_
   </repositories>_x000D_
 </profile>_x000D_
</profiles>
_x000D_
_x000D_
_x000D_

Note that you should ensure that the id of the server tag should be the same as the id of the repository tag.

Android Studio: Add jar as library?

With Android Studio 3+:

You should just be able to simply copy the jar file to the libs folder right under the app folder.

... myproject\app\libs\myfile.jar

Then select Project Files from the drop-down on the Projects window, right click on the project, select Synchronize to see the file in Project Files. It will automatically add the dependencies in the gradle file (Module:app).

dependencies {
...
    implementation files('libs/myfile.jar')

Here is another solution:

Go to the Project Files view (select Project Files from the dropdown).

enter image description here

Select New... Directory, create a folder named libs right under app.

enter image description here

Open up File Explorer, copy and paste your jar file into the libs folder.

In Android Studio, right click on the jar file, and select Add as a Library... from the popup menu.

enter image description here

You should see the file listed in the dependencies list in the gradle file:

dependencies {
...
    implementation files('libs/myfile.jar')
}

Open up your java file, and add the import statement there:

import com.xxx.xxx;

How to run or debug php on Visual Studio Code (VSCode)

XDebug changed some configuration settings.

Old settings:

xdebug.remote_enable = 1
xdebug.remote_autostart = 1
xdebug.remote_port = 9000

New settings:

xdebug.mode=debug
xdebug.start_with_request=yes
xdebug.client_port=9000

So you should paste the latter in php.ini file. More info: XDebug Changed Configuration Settings

Clear an input field with Reactjs?

I have a similar solution to @Satheesh using React hooks:

State initialization:

const [enteredText, setEnteredText] = useState(''); 

Input tag:

<input type="text" value={enteredText}  (event handler, classNames, etc.) />

Inside the event handler function, after updating the object with data from input form, call:

setEnteredText('');

Note: This is described as 'two-way binding'

What is Python Whitespace and how does it work?

It acts as curly bracket. We have to keep the number of white spaces consistent through out the program.

Example 1:

def main():
     print "we are in main function"
     print "print 2nd line"

main()

Result:

We are in main function
print 2nd line

Example 2:

def main():
    print "we are in main function"
print "print 2nd line"

main()

Result:

print 2nd line
We are in main function

Here, in the 1st program, both the statement comes under the main function since both have equal number of white spaces while in the 2nd program, the 1st line is printed later because the main function is called after the 2nd line Note - The 2nd line has no white space, so it is independent of the main function.

AngularJS - Any way for $http.post to send request parameters instead of JSON?

If using Angular >= 1.4, here's the cleanest solution I've found that doesn't rely on anything custom or external:

angular.module('yourModule')
  .config(function ($httpProvider, $httpParamSerializerJQLikeProvider){
    $httpProvider.defaults.transformRequest.unshift($httpParamSerializerJQLikeProvider.$get());
    $httpProvider.defaults.headers.post['Content-Type'] = 'application/x-www-form-urlencoded; charset=utf-8';
});

And then you can do this anywhere in your app:

$http({
  method: 'POST',
  url: '/requesturl',
  data: {
    param1: 'value1',
    param2: 'value2'
  }
});

And it will correctly serialize the data as param1=value1&param2=value2 and send it to /requesturl with the application/x-www-form-urlencoded; charset=utf-8 Content-Type header as it's normally expected with POST requests on endpoints.

How do I delete an entity from symfony2

From what I understand, you struggle with what to put into your template.

I'll show an example:

<ul>
    {% for guest in guests %}
    <li>{{ guest.name }} <a href="{{ path('your_delete_route_name',{'id': guest.id}) }}">[[DELETE]]</a></li>
    {% endfor %}
</ul>

Now what happens is it iterates over every object within guests (you'll have to rename this if your object collection is named otherwise!), shows the name and places the correct link. The route name might be different.

NLS_NUMERIC_CHARACTERS setting for decimal

You can see your current session settings by querying nls_session_parameters:

select value
from nls_session_parameters
where parameter = 'NLS_NUMERIC_CHARACTERS';

VALUE                                  
----------------------------------------
.,                                       

That may differ from the database defaults, which you can see in nls_database_parameters.

In this session your query errors:

select to_number('100,12') from dual;

Error report -
SQL Error: ORA-01722: invalid number
01722. 00000 -  "invalid number"

I could alter my session, either directly with alter session or by ensuring my client is configured in a way that leads to the setting the string needs (it may be inherited from a operating system or Java locale, for example):

alter session set NLS_NUMERIC_CHARACTERS = ',.';
select to_number('100,12') from dual;

TO_NUMBER('100,12')
-------------------
             100,12 

In SQL Developer you can set your preferred value in Tool->Preferences->Database->NLS.

But I can also override that session setting as part of the query, with the optional third nlsparam parameter to to_number(); though that makes the optional second fmt parameter necessary as well, so you'd need to be able pick a suitable format:

alter session set NLS_NUMERIC_CHARACTERS = '.,';
select to_number('100,12', '99999D99', 'NLS_NUMERIC_CHARACTERS='',.''')
from dual;

TO_NUMBER('100,12','99999D99','NLS_NUMERIC_CHARACTERS='',.''')
--------------------------------------------------------------
                                                        100.12 

By default the result is still displayed with my session settings, so the decimal separator is still a period.

How to change menu item text dynamically in Android

It seems to me that you want to change the contents of menu inside a local method, and this method is called at any time, whenever an event is occurred, or in the activity UI thread.

Why don't you take the instance of Menu in the global variable in onPrepareOptionsMenu when this is overridden and use in this method of yours. Be sure that this method is called whenever an event is occurred (like button click), or in the activity UI thread, handler or async-task post-execute.

You should know in advance the index of this menu item you want to change. After clearing the menu, you need to inflate the menu XML and update your item's name or icon.

How to create a HashMap with two keys (Key-Pair, Value)?

You can also use guava Table implementation for this.

Table represents a special map where two keys can be specified in combined fashion to refer to a single value. It is similar to creating a map of maps.

//create a table
  Table<String, String, String> employeeTable = HashBasedTable.create();

  //initialize the table with employee details
  employeeTable.put("IBM", "101","Mahesh");
  employeeTable.put("IBM", "102","Ramesh");
  employeeTable.put("IBM", "103","Suresh");

  employeeTable.put("Microsoft", "111","Sohan");
  employeeTable.put("Microsoft", "112","Mohan");
  employeeTable.put("Microsoft", "113","Rohan");

  employeeTable.put("TCS", "121","Ram");
  employeeTable.put("TCS", "122","Shyam");
  employeeTable.put("TCS", "123","Sunil");

  //get Map corresponding to IBM
  Map<String,String> ibmEmployees =  employeeTable.row("IBM");

How to use enums in C++

Rather than using a bunch of if-statements, enums lend themselves well to switch statements

I use some enum/switch combinations in the level builder I am building for my game.

EDIT: Another thing, I see you want syntax similar to;

if(day == Days.Saturday)
etc

You can do this in C++:

if(day == Days::Saturday)
etc

Here is a very simple example:

EnumAppState.h

#ifndef ENUMAPPSTATE_H
#define ENUMAPPSTATE_H
enum eAppState
{
    STARTUP,
    EDIT,
    ZONECREATION,
    SHUTDOWN,
    NOCHANGE
};
#endif

Somefile.cpp

#include "EnumAppState.h"
eAppState state = eAppState::STARTUP;
switch(state)
{
case STARTUP:
    //Do stuff
    break;
case EDIT:
    //Do stuff
    break;
case ZONECREATION:
    //Do stuff
    break;
case SHUTDOWN:
    //Do stuff
    break;
case NOCHANGE:
    //Do stuff
    break;
}

Resize on div element

Only window is supported yes but you could use a plugin for it: http://benalman.com/projects/jquery-resize-plugin/

Setting Environment Variables for Node to retrieve

Make your life easier with dotenv-webpack. Simply install it npm install dotenv-webpack --save-dev, then create an .env file in your application's root (remember to add this to .gitignore before you git push). Open this file, and set some environmental variables there, like for example:

ENV_VAR_1=1234
ENV_VAR_2=abcd
ENV_VAR_3=1234abcd

Now, in your webpack config add:

const Dotenv = require('dotenv-webpack');
const webpackConfig = {
  node: { global: true, fs: 'empty' }, // Fix: "Uncaught ReferenceError: global is not defined", and "Can't resolve 'fs'".
  output: {
    libraryTarget: 'umd' // Fix: "Uncaught ReferenceError: exports is not defined".
  },
  plugins: [new Dotenv()]
};
module.exports = webpackConfig; // Export all custom Webpack configs.

Only const Dotenv = require('dotenv-webpack');, plugins: [new Dotenv()], and of course module.exports = webpackConfig; // Export all custom Webpack configs. are required. However, in some scenarios you might get some errors. For these you have the solution as well implying how you can fix certain error.

Now, wherever you want you can simply use process.env.ENV_VAR_1, process.env.ENV_VAR_2, process.env.ENV_VAR_3 in your application.

Retrieving Property name from lambda expression

I've found that some of the suggested answers which drill down into the MemberExpression/UnaryExpression don't capture nested/subproperties.

ex) o => o.Thing1.Thing2 returns Thing1 rather than Thing1.Thing2.

This distinction is important if you're trying to work with EntityFramework DbSet.Include(...).

I've found that just parsing the Expression.ToString() seems to work fine, and comparatively quickly. I compared it against the UnaryExpression version, and even getting ToString off of the Member/UnaryExpression to see if that was faster, but the difference was negligible. Please correct me if this is a terrible idea.

The Extension Method

/// <summary>
/// Given an expression, extract the listed property name; similar to reflection but with familiar LINQ+lambdas.  Technique @via https://stackoverflow.com/a/16647343/1037948
/// </summary>
/// <remarks>Cheats and uses the tostring output -- Should consult performance differences</remarks>
/// <typeparam name="TModel">the model type to extract property names</typeparam>
/// <typeparam name="TValue">the value type of the expected property</typeparam>
/// <param name="propertySelector">expression that just selects a model property to be turned into a string</param>
/// <param name="delimiter">Expression toString delimiter to split from lambda param</param>
/// <param name="endTrim">Sometimes the Expression toString contains a method call, something like "Convert(x)", so we need to strip the closing part from the end</param>
/// <returns>indicated property name</returns>
public static string GetPropertyName<TModel, TValue>(this Expression<Func<TModel, TValue>> propertySelector, char delimiter = '.', char endTrim = ')') {

    var asString = propertySelector.ToString(); // gives you: "o => o.Whatever"
    var firstDelim = asString.IndexOf(delimiter); // make sure there is a beginning property indicator; the "." in "o.Whatever" -- this may not be necessary?

    return firstDelim < 0
        ? asString
        : asString.Substring(firstDelim+1).TrimEnd(endTrim);
}//--   fn  GetPropertyNameExtended

(Checking for the delimiter might even be overkill)

Demo (LinqPad)

Demonstration + Comparison code -- https://gist.github.com/zaus/6992590

How can I change the app display name build with Flutter?

First Rename your AndroidManifest.xml file

android:label="Your App Name"

Second Rename Your Application Name in Pubspec.yaml file name: Your Application Name

Third Change Your Application logo

flutter_icons:
   android: "launcher_icon"
   ios: true
   image_path: "assets/path/your Application logo.formate"

Fourth Run

flutter pub pub run flutter_launcher_icons:main

How can I send a file document to the printer and have it print?

    public static void PrintFileToDefaultPrinter(string FilePath)
    {
        try
        {
            var file = File.ReadAllBytes(FilePath);
            var printQueue = LocalPrintServer.GetDefaultPrintQueue();

            using (var job = printQueue.AddJob())
            using (var stream = job.JobStream)
            {
                stream.Write(file, 0, file.Length);
            }
        }
        catch (Exception)
        {

            throw;
        }
    }

How should I do integer division in Perl?

The lexically scoped integer pragma forces Perl to use integer arithmetic in its scope:

print 3.0/2.1 . "\n";    # => 1.42857142857143
{
  use integer;
  print 3.0/2.1 . "\n";  # => 1
}
print 3.0/2.1 . "\n";    # => 1.42857142857143

The application was unable to start correctly (0xc000007b)

You can have this if you are trying to manifest your application that it has a dependancy on the Microsoft.Windows.Common-Controls assembly. You do this when you want to load Version 6 of the common controls library - so that visual styles are applied to common controls.

You probably followed Microsoft's original documentation way back from Windows XP days, and added the following to your application's manifest:

<!-- Dependancy on Common Controls version 6 -->
<dependency>
    <dependentAssembly>
        <assemblyIdentity
                type="win32"
                name="Microsoft.Windows.Common-Controls"
                version="6.0.0.0"
                processorArchitecture="X86"
                publicKeyToken="6595b64144ccf1df"
                language="*"/>
    </dependentAssembly>
</dependency>

Windows XP is no longer the OS, and you're no longer a 32-bit application. In the intervening 17 years Microsoft updated their documentation; now it's time for you to update your manifest:

<!-- Dependancy on Common Controls version 6 -->
<dependency>
    <dependentAssembly>
        <assemblyIdentity
                type="win32"
                name="Microsoft.Windows.Common-Controls"
                version="6.0.0.0"
                processorArchitecture="*"
                publicKeyToken="6595b64144ccf1df"
                language="*"/>
    </dependentAssembly>
</dependency>

Raymond Chen has a lovely history of the Common Controls:

java.net.ConnectException :connection timed out: connect?

If you're pointing the config at a domain (eg fabrikam.com), do an NSLOOKUP to ensure all the responding IPs are valid, and can be connected to on port 389:

NSLOOKUP fabrikam.com

Test-NetConnection <IP returned from NSLOOKUP> -port 389

How to crop(cut) text files based on starting and ending line-numbers in cygwin?

How about this:

$ seq 1 100000 | tail -n +10000 | head -n 10
10000
10001
10002
10003
10004
10005
10006
10007
10008
10009

It uses tail to output from the 10,000th line and onwards and then head to only keep 10 lines.

The same (almost) result with sed:

$ seq 1 100000 | sed -n '10000,10010p'
10000
10001
10002
10003
10004
10005
10006
10007
10008
10009
10010

This one has the advantage of allowing you to input the line range directly.

android edittext onchange listener

In Kotlin Android EditText listener is set using,

   val searchTo : EditText = findViewById(R.id.searchTo)
   searchTo.addTextChangedListener(object : TextWatcher {
    override fun afterTextChanged(s: Editable) {

        // you can call or do what you want with your EditText here

        // yourEditText...
    }

    override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {}
    override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {}
})

Angular ngClass and click event for toggling class

So normally you would create a backing variable in the class and toggle it on click and tie a class binding to the variable. Something like:

@Component(
    selector:'foo',
    template:`<a (click)="onClick()"
                         [class.selected]="wasClicked">Link</a>
    `)
export class MyComponent {
    wasClicked = false;

    onClick() {
        this.wasClicked= !this.wasClicked;
    }
}

Bootstrap 3 offset on right not left

Here is the same solution than Rukshan but in sass (in order to keep your grid configuration) for special case that don't work with Ross Allen solution (when you can't have a parent div.row)

@mixin make-grid-offset-right($class) {
    @for $index from 0 through $grid-columns {
        .col-#{$class}-offset-right-#{$index} {
            margin-right: percentage(($index / $grid-columns));
        }
    }
}

@include make-grid-offset-right(xs);

@media (min-width: $screen-sm-min) {
  @include make-grid-offset-right(sm);
}

@media (min-width: $screen-md-min) {
  @include make-grid-offset-right(md);
}

@media (min-width: $screen-lg-min) {
  @include make-grid-offset-right(lg);
}

The Completest Cocos2d-x Tutorial & Guide List

Good list. The Angry Ninjas Starter Kit will have a Cocos2d-X update soon.

Difference between wait and sleep

wait releases the lock and sleep doesn't. A thread in waiting state is eligible for waking up as soon as notify or notifyAll is called. But in case of sleep the thread keeps the lock and it'll only be eligible once the sleep time is over.

Most efficient way to append arrays in C#?

using this we can add two array with out any loop.

I believe if you have 2 arrays of the same type that you want to combine into one of array, there's a very simple way to do that.

Here's the code:

String[] TextFils = Directory.GetFiles(basePath, "*.txt");
String[] ExcelFils = Directory.GetFiles(basePath, "*.xls");
String[] finalArray = TextFils.Concat(ExcelFils).ToArray();

or

String[] Fils = Directory.GetFiles(basePath, "*.txt");
String[] ExcelFils = Directory.GetFiles(basePath, "*.xls");
Fils = Fils.Concat(ExcelFils).ToArray();

How to generate UML diagrams (especially sequence diagrams) from Java code?

I would recommend EclipseUML from Omondo for general usage, although I did experience some problems a few months back, with my web projects. They had a free edition at one point in time, but that is supposedly no longer promoted.

If you are really keen on reverse engineering sequence diagrams from source code, I would recommend jTracert.

As far as Eclipse projects themselves are concerned, the Eclipse UML2 Tools project might support reverse engineering, although I've have never seen its use in practice.

The MoDisco (Model Discovery) project Eclipse GMT project seems to be clearer in achieving your objective. The list of technology specific tools would be a good place to start with.

How to find count of Null and Nan values for each column in a PySpark dataframe efficiently?

An alternative to the already provided ways is to simply filter on the column like so

df = df.where(F.col('columnNameHere').isNull())

This has the added benefit that you don't have to add another column to do the filtering and it's quick on larger data sets.

Redirect pages in JSP?

Extending @oopbase's answer with return; statement.

Let's consider a use case of traditional authentication system where we store login information into the session. On each page we check for active session like,

/* Some Import Statements here. */

if(null == session || !session.getAttribute("is_login").equals("1")) {
    response.sendRedirect("http://domain.com/login");
}

// ....

session.getAttribute("user_id");

// ....
/* Some More JSP+Java+HTML code here */

It looks fine at first glance however; It has one issue. If your server has expired session due to time limit and user is trying to access the page he might get error if you have not written your code in try..catch block or handled if(null != session.getAttribute("attr_name")) everytime.

So by putting a return; statement I stopped further execution and forced to redirect page to certain location.

if(null == session || !session.getAttribute("is_login").equals("1")) {
    response.sendRedirect("http://domain.com/login");
    return;
}

Note that Use of redirection may vary based on the requirements. Nowadays people don't use such authentication system. (Modern approach - Token Based Authentication) It's just an simple example to understand where and how to place redirection(s).

How to check if an element does NOT have a specific class?

sdleihssirhc's answer is of course the correct one for the case in the question, but just as a reference if you need to select elements that don't have a certain class, you can use the not selector:

// select all divs that don't have class test
$( 'div' ).not( ".test" );
$( 'div:not(.test)' );  // <-- alternative 

.autocomplete is not a function Error

My issue ended up being visual studio catching an unhandled exception and preventing the script from running any further. Because I was running in the IDE, it looked like there was an issue when there wasn't. Autocomplete was working just fine. I added a try/catch block and that made the IDE happy.

 $.ajax({
            url: "/MyController/MyAction",
            type: "POST",
            dataType: "json",
            data: { prefix: request.term },
            success: function (data) {
                try {
                    response($.map(data, function (item) {
                        return { label: item.Name, value: item.Name };
                    }))
                } catch (err) { }

            }
        })

Check if an object exists

Since filter returns a QuerySet, you can use count to check how many results were returned. This is assuming you don't actually need the results.

num_results = User.objects.filter(email = cleaned_info['username']).count()

After looking at the documentation though, it's better to just call len on your filter if you are planning on using the results later, as you'll only be making one sql query:

A count() call performs a SELECT COUNT(*) behind the scenes, so you should always use count() rather than loading all of the record into Python objects and calling len() on the result (unless you need to load the objects into memory anyway, in which case len() will be faster).

num_results = len(user_object)

How to get a cross-origin resource sharing (CORS) post request working

REQUEST:

 $.ajax({
            url: "http://localhost:8079/students/add/",
            type: "POST",
            crossDomain: true,
            data: JSON.stringify(somejson),
            dataType: "json",
            success: function (response) {
                var resp = JSON.parse(response)
                alert(resp.status);
            },
            error: function (xhr, status) {
                alert("error");
            }
        });

RESPONSE:

response = HttpResponse(json.dumps('{"status" : "success"}'))
response.__setitem__("Content-type", "application/json")
response.__setitem__("Access-Control-Allow-Origin", "*")

return response

jQuery .each() with input elements

You can use:

$(formId).serializeArray();

pandas convert some columns into rows

I guess I found a simpler solution

temp1 = pd.melt(df1, id_vars=["location"], var_name='Date', value_name='Value')
temp2 = pd.melt(df1, id_vars=["name"], var_name='Date', value_name='Value')

Concat whole temp1 with temp2's column name

temp1['new_column'] = temp2['name']

You now have what you asked for.

What is the difference between signed and unsigned variables?

Unsigned variables are variables which are internally represented without a mathematical sign (plus or minus) can store 'zero' or positive values only. Let us say the unsigned variable is n bits in size, then it can represent 2^n (2 power n) values - 0 through (2^n -1). A signed variable on the other hand, 'loses' one bit for representing the sign, so it can store values from -(2^(n-1) -1) through (2^(n-1)) including zero. Thus, a signed variable can store positive values, negative values and zero.

P.S.:
Internally, the mathematical sign may be represented in one's complement form, two's complement form or with a sign bit (eg: 0 -> +, 1-> -)
All these methods effectively divide the range of representable values in n bits (2^n) into three parts, positive, negative and zero.

This is just my two cents worth.

I hope this helps.

Example: Communication between Activity and Service using Messaging

Note: You don't need to check if your service is running, CheckIfServiceIsRunning(), because bindService() will start it if it isn't running.

Also: if you rotate the phone you don't want it to bindService() again, because onCreate() will be called again. Be sure to define onConfigurationChanged() to prevent this.

How to reset or change the passphrase for a GitHub SSH key?

You can change the passphrase for your private key by doing:

ssh-keygen -f ~/.ssh/id_rsa -p

Abort a Git Merge

as long as you did not commit you can type

git merge --abort

just as the command line suggested.

How to initialize var?

var just tells the compiler to infer the type you wanted at compile time...it cannot infer from null (though there are cases it could).

So, no you are not allowed to do this.

When you say "some empty value"...if you mean:

var s = string.Empty;
//
var s = "";

Then yes, you may do that, but not null.

Using ls to list directories and their total sizes

du -S

du have another useful option: -S, --separate-dirs telling du not include size of subdirectories - handy on some occasions.

Example 1 - shows only the file sizes in a directory:

du -Sh  * 
3,1G    10/CR2
280M    10

Example 2 - shows the file sizes and subdirectories in directory:

du -h  * 
3,1G    10/CR2 
3,4G    10

How can I get the client's IP address in ASP.NET MVC?

I had trouble using the above, and I needed the IP address from a controller. I used the following in the end:

System.Web.HttpContext.Current.Request.UserHostAddress

openCV program compile error "libopencv_core.so.2.4: cannot open shared object file: No such file or directory" in ubuntu 12.04

Add this link:

/usr/local/lib/*.so.*

The total is:

g++ -o main.out main.cpp -I /usr/local/include -I /usr/local/include/opencv -I /usr/local/include/opencv2 -L /usr/local/lib /usr/local/lib/*.so /usr/local/lib/*.so.*

How to change an Eclipse default project into a Java project

You can do it directly from eclipse using the Navigator view (Window -> Show View -> Navigator). In the Navigator view select the project and open it so that you can see the file .project. Right click -> Open. You will get a XML editor view. Edit the content of the node natures and insert a new child nature with org.eclipse.jdt.core.javanature as content. Save.

Now create a file .classpath, it will open in the XML editor. Add a node named classpath, add a child named classpathentry with the attributes kind with content con and another one named path and content org.eclipse.jdt.launching.JRE_CONTAINER. Save-

Much easier: copy the files .project and .classpath from an existing Java project and edit the node result name to the name of this project. Maybe you have to refresh the project (F5).

You'll get the same result as with the solution of Chris Marasti-Georg.

Edit

enter image description here

DataGridView AutoFit and Fill

public void setHeight(DataGridView src)
{
    src.Height= src.ColumnHeadersVisible ? src.ColumnHeadersHeight : 0 +   src.Rows.OfType<DataGridViewRow>().Where(row => row.Visible).Sum(row => row.Height);
}

Angularjs checkbox checked by default on load and disables Select list when checked

Do it in the controller

_x000D_
_x000D_
$timeout(function(){
$scope.checked = true;
}, 1);
_x000D_
_x000D_
_x000D_

then remove ng-checked.

Java Scanner String input

use this to clear the previous keyboard buffer before scanning the string it will solve your problem scanner.nextLine();//this is to clear the keyboard buffer