Programs & Examples On #Dyalog

How to get am pm from the date time string using moment js

You are using the wrong format tokens when parsing your input. You should use ddd for an abbreviation of the name of day of the week, DD for day of the month, MMM for an abbreviation of the month's name, YYYY for the year, hh for the 1-12 hour, mm for minutes and A for AM/PM. See moment(String, String) docs.

Here is a working live sample:

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console.log( moment('Mon 03-Jul-2017, 11:00 AM', 'ddd DD-MMM-YYYY, hh:mm A').format('hh:mm A') );_x000D_
console.log( moment('Mon 03-Jul-2017, 11:00 PM', 'ddd DD-MMM-YYYY, hh:mm A').format('hh:mm A') );
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.18.1/moment.min.js"></script>
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_x000D_
_x000D_

Several ports (8005, 8080, 8009) required by Tomcat Server at localhost are already in use

If Eclipse says

Several ports (8005, 8080, 8009) required by Tomcat v6.0 Server at localhost are already in use

This error comes because tomcat may be running in background so first stop that server..follow the below details.

Solution is:

  1. Open the "console" view (window->show view->Console)
  2. Then stop the tomcat server.
  3. Then open the "server" view and start the server it will work.

Thanks!

Force IE9 to emulate IE8. Possible?

Yes. Recent versions of IE (IE8 or above) let you adjust that. Here's how:

  • Fire up Internet Explorer.
  • Click the 'Tools' menu, then click 'Developer Tools'. Alternatively, just press F12.

That should open the Developer Tools window. That window has two menu items that are of interest:

  • Browser Mode. This setting determines the value of the user-agent header sent for every request.
  • Document Mode. This setting determines how the rendering engine renders the page.

More at http://blogs.msdn.com/b/ie/archive/2010/06/16/ie-s-compatibility-features-for-site-developers.aspx

How to use Comparator in Java to sort

Here's an example of a Comparator that will work for any zero arg method that returns a Comparable. Does something like this exist in a jdk or library?

import java.lang.reflect.Method;
import java.util.Comparator;

public class NamedMethodComparator implements Comparator<Object> {

    //
    // instance variables
    //

    private String methodName;

    private boolean isAsc;

    //
    // constructor
    //

    public NamedMethodComparator(String methodName, boolean isAsc) {
        this.methodName = methodName;
        this.isAsc = isAsc;
    }

    /**
     * Method to compare two objects using the method named in the constructor.
     */
    @Override
    public int compare(Object obj1, Object obj2) {
        Comparable comp1 = getValue(obj1, methodName);
        Comparable comp2 = getValue(obj2, methodName);
        if (isAsc) {
            return comp1.compareTo(comp2);
        } else {
            return comp2.compareTo(comp1);
        }
    }

    //
    // implementation
    //

    private Comparable getValue(Object obj, String methodName) {
        Method method = getMethod(obj, methodName);
        Comparable comp = getValue(obj, method);
        return comp;
    }

    private Method getMethod(Object obj, String methodName) {
        try {
            Class[] signature = {};
            Method method = obj.getClass().getMethod(methodName, signature);
            return method;
        } catch (Exception exp) {
            throw new RuntimeException(exp);
        }
    }

    private Comparable getValue(Object obj, Method method) {
        Object[] args = {};
        try {
            Object rtn = method.invoke(obj, args);
            Comparable comp = (Comparable) rtn;
            return comp;
        } catch (Exception exp) {
            throw new RuntimeException(exp);
        }
    }

}

WCF ServiceHost access rights

I am working on Windows Vista. Even i faced the same problem but when i tried to run VS 2008 with administrative privileges, the issue resolved and my service was up and running. :)

Read file from aws s3 bucket using node fs

This will do it:

new AWS.S3().getObject({ Bucket: this.awsBucketName, Key: keyName }, function(err, data)
{
    if (!err)
        console.log(data.Body.toString());
});

Button Listener for button in fragment in android

Your fragment class should implement OnClickListener

public class SmartTvControllerFragment extends Fragment implements View.OnClickListener

Then get view, link button and set onClickListener like in example below

 View view;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    view = inflater.inflate(R.layout.smart_tv_controller_fragment, container, false);
    upButton = (Button) view.findViewById(R.id.smart_tv_controller_framgment_up_button);
    upButton.setOnClickListener(this);
    return view;
 }

And then add onClickListener method and do what you want.

@Override
public void onClick(View v) {
 //do what you want to do when button is clicked
    switch (v.getId()) {
        case R.id.textView_help:
            switchFragment(HelpFragment.TAG);
            break;
        case R.id.textView_settings:
            switchFragment(SettingsFragment.TAG);
            break;
    }
}

This is my example of code, but I hope you understood

Swing JLabel text change on the running application

import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
import java.awt.event.*;
public class Test extends JFrame implements ActionListener
{
    private JLabel label;
    private JTextField field;
    public Test()
    {
        super("The title");
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setPreferredSize(new Dimension(400, 90));
        ((JPanel) getContentPane()).setBorder(new EmptyBorder(13, 13, 13, 13) );
        setLayout(new FlowLayout());
        JButton btn = new JButton("Change");
        btn.setActionCommand("myButton");
        btn.addActionListener(this);
        label = new JLabel("flag");
        field = new JTextField(5);
        add(field);
        add(btn);
        add(label);
        pack();
        setLocationRelativeTo(null);
        setVisible(true);
        setResizable(false);
    }
    public void actionPerformed(ActionEvent e)
    {
        if(e.getActionCommand().equals("myButton"))
        {
            label.setText(field.getText());
        }
    }
    public static void main(String[] args)
    {
        new Test();
    }
}

How do I bind a WPF DataGrid to a variable number of columns?

Made a version of the accepted answer that handles unsubscription.

public class DataGridColumnsBehavior
{
    public static readonly DependencyProperty BindableColumnsProperty =
        DependencyProperty.RegisterAttached("BindableColumns",
                                            typeof(ObservableCollection<DataGridColumn>),
                                            typeof(DataGridColumnsBehavior),
                                            new UIPropertyMetadata(null, BindableColumnsPropertyChanged));

    /// <summary>Collection to store collection change handlers - to be able to unsubscribe later.</summary>
    private static readonly Dictionary<DataGrid, NotifyCollectionChangedEventHandler> _handlers;

    static DataGridColumnsBehavior()
    {
        _handlers = new Dictionary<DataGrid, NotifyCollectionChangedEventHandler>();
    }

    private static void BindableColumnsPropertyChanged(DependencyObject source, DependencyPropertyChangedEventArgs e)
    {
        DataGrid dataGrid = source as DataGrid;

        ObservableCollection<DataGridColumn> oldColumns = e.OldValue as ObservableCollection<DataGridColumn>;
        if (oldColumns != null)
        {
            // Remove all columns.
            dataGrid.Columns.Clear();

            // Unsubscribe from old collection.
            NotifyCollectionChangedEventHandler h;
            if (_handlers.TryGetValue(dataGrid, out h))
            {
                oldColumns.CollectionChanged -= h;
                _handlers.Remove(dataGrid);
            }
        }

        ObservableCollection<DataGridColumn> newColumns = e.NewValue as ObservableCollection<DataGridColumn>;
        dataGrid.Columns.Clear();
        if (newColumns != null)
        {
            // Add columns from this source.
            foreach (DataGridColumn column in newColumns)
                dataGrid.Columns.Add(column);

            // Subscribe to future changes.
            NotifyCollectionChangedEventHandler h = (_, ne) => OnCollectionChanged(ne, dataGrid);
            _handlers[dataGrid] = h;
            newColumns.CollectionChanged += h;
        }
    }

    static void OnCollectionChanged(NotifyCollectionChangedEventArgs ne, DataGrid dataGrid)
    {
        switch (ne.Action)
        {
            case NotifyCollectionChangedAction.Reset:
                dataGrid.Columns.Clear();
                foreach (DataGridColumn column in ne.NewItems)
                    dataGrid.Columns.Add(column);
                break;
            case NotifyCollectionChangedAction.Add:
                foreach (DataGridColumn column in ne.NewItems)
                    dataGrid.Columns.Add(column);
                break;
            case NotifyCollectionChangedAction.Move:
                dataGrid.Columns.Move(ne.OldStartingIndex, ne.NewStartingIndex);
                break;
            case NotifyCollectionChangedAction.Remove:
                foreach (DataGridColumn column in ne.OldItems)
                    dataGrid.Columns.Remove(column);
                break;
            case NotifyCollectionChangedAction.Replace:
                dataGrid.Columns[ne.NewStartingIndex] = ne.NewItems[0] as DataGridColumn;
                break;
        }
    }

    public static void SetBindableColumns(DependencyObject element, ObservableCollection<DataGridColumn> value)
    {
        element.SetValue(BindableColumnsProperty, value);
    }

    public static ObservableCollection<DataGridColumn> GetBindableColumns(DependencyObject element)
    {
        return (ObservableCollection<DataGridColumn>)element.GetValue(BindableColumnsProperty);
    }
}

Efficiently finding the last line in a text file

The inefficiency here is not really due to Python, but to the nature of how files are read. The only way to find the last line is to read the file in and find the line endings. However, the seek operation may be used to skip to any byte offset in the file. You can, therefore begin very close to the end of the file, and grab larger and larger chunks as needed until the last line ending is found:

from os import SEEK_END

def get_last_line(file):
  CHUNK_SIZE = 1024 # Would be good to make this the chunk size of the filesystem

  last_line = ""

  while True:
    # We grab chunks from the end of the file towards the beginning until we 
    # get a new line
    file.seek(-len(last_line) - CHUNK_SIZE, SEEK_END)
    chunk = file.read(CHUNK_SIZE)

    if not chunk:
      # The whole file is one big line
      return last_line

    if not last_line and chunk.endswith('\n'):
      # Ignore the trailing newline at the end of the file (but include it 
      # in the output).
      last_line = '\n'
      chunk = chunk[:-1]

    nl_pos = chunk.rfind('\n')
    # What's being searched for will have to be modified if you are searching
    # files with non-unix line endings.

    last_line = chunk[nl_pos + 1:] + last_line

    if nl_pos == -1:
      # The whole chunk is part of the last line.
      continue

    return last_line

JavaScript TypeError: Cannot read property 'style' of null

I met the same problem, the situation is I need to download flash game by embed tag and H5 game by iframe, I need a loading box there, when the flash or H5 download done, let the loading box display none. well, the flash one work well but when things go to iframe, I cannot find the property 'style' of null , so I add a clock to it , and it works

let clock = setInterval(() => {
        clearInterval(clock)
        clock = null
        document.getElementById('loading-box').style.display = 'none'
    }, 200)

How to pass value from <option><select> to form action

with jQuery :
html :

<form method="POST" name="myform" action="index.php?action=contact_agent&agent_id="  onsubmit="SetData()">
  <select name="agent" id="agent">
    <option value="1">Agent Homer</option>
    <option value="2">Agent Lenny</option>
    <option value="3">Agent Carl</option>
  </select>
</form>

jQuery :

$('form').submit(function(){
   $(this).attr('action',$(this).attr('action')+$('#agent').val());
   $(this).submit();
});

javascript :

function SetData(){
   var select = document.getElementById('agent');
   var agent_id = select.options[select.selectedIndex].value;
   document.myform.action = "index.php?action=contact_agent&agent_id="+agent_id ; # or .getAttribute('action')
   myform.submit();
}

Change User Agent in UIWebView

Very simple in Swift. Just place the following into your App Delegate.

UserDefaults.standard.register(defaults: ["UserAgent" : "Custom Agent"])

If you want to append to the existing agent string then:

let userAgent = UIWebView().stringByEvaluatingJavaScript(from: "navigator.userAgent")! + " Custom Agent"
UserDefaults.standard.register(defaults: ["UserAgent" : userAgent])

Note: You may will need to uninstall and reinstall the App to avoid appending to the existing agent string.

How to make a query with group_concat in sql server

Please run the below query, it doesn't requires STUFF and GROUP BY in your case:

Select
      A.maskid
    , A.maskname
    , A.schoolid
    , B.schoolname
    , CAST((
          SELECT  T.maskdetail+','
          FROM dbo.maskdetails T
          WHERE A.maskid = T.maskid
          FOR XML PATH(''))as varchar(max)) as maskdetail 
FROM dbo.tblmask A
JOIN dbo.school B ON B.ID = A.schoolid

Prevent any form of page refresh using jQuery/Javascript

Back in the ole days of CGI we had many forms that would trigger various backend actions. Such as text notifications to groups, print jobs, farming of data, etc.

If the user was on a page that was saying "Please wait... Performing some HUGE job that could take some time.". They were more likely to hit REFRESH and this would be BAD!

WHY? Because it would trigger more slow jobs and eventually bog down the whole thing.

The solution? Allow them to do their form. When they submit their form... Start your job and then direct them to another page that tells them to wait.

Where the page in the middle actually held the form data that was needed to start the job. The WAIT page however contains a javascript history destroy. So they can RELOAD that wait page all they want and it will never trigger the original job to start in the background as that WAIT page only contains the form data needed for the WAIT itself.

Hope that makes sense.

The history destroy function also prevented them from clicking BACK and then refreshing as well.

It was very seamless and worked great for MANY MANY years until the non-profit was wound down.

Example: FORM ENTRY - Collect all their info and when submitted, this triggers your backend job.

RESPONSE from form entry - Returns HTML that performs a redirect to your static wait page and/or POST/GET to another form (the WAIT page).

WAIT PAGE - Only contains FORM data related to wait page as well as javascript to destroy the most recent history. Like (-1 OR -2) to only destroy the most recent pages, but still allows them to go back to their original FORM entry page.

Once they are at your WAIT page, they can click REFRESH as much as they want and it will never spawn the original FORM job on the backend. Instead, your WAIT page should embrace a META timed refresh itself so it can always check on the status of their job. When their job is completed, they are redirected away from the wait page to whereever you wish.

If they do manually REFRESH... They are simply adding one more check of their job status in there.

Hope that helps. Good luck.

TCPDF Save file to folder?

For who is having difficulties storing the file, the path has to be all the way through root. For example, mine was:

$pdf->Output('/home/username/public_html/app/admin/pdfs/filename.pdf', 'F');

How to correct TypeError: Unicode-objects must be encoded before hashing?

The error already says what you have to do. MD5 operates on bytes, so you have to encode Unicode string into bytes, e.g. with line.encode('utf-8').

The program can't start because api-ms-win-crt-runtime-l1-1-0.dll is missing while starting Apache server on my computer

I was facing the same issue. After many tries below solution worked for me.

Before installing VC++ install your windows updates. 1. Go to Start - Control Panel - Windows Update 2. Check for the updates. 3. Install all updates. 4. Restart your system.

After that you can follow the below steps.

@ABHI KUMAR

Download the Visual C++ Redistributable 2015

Visual C++ Redistributable for Visual Studio 2015 (64-bit)

Visual C++ Redistributable for Visual Studio 2015 (32-bit)

(Reinstal if already installed) then restart your computer or use windows updates for download auto.

For link download https://www.microsoft.com/de-de/download/details.aspx?id=48145.

How to send HTTP request in java?

Google java http client has nice API for http requests. You can easily add JSON support etc. Although for simple request it might be overkill.

import com.google.api.client.http.GenericUrl;
import com.google.api.client.http.HttpRequest;
import com.google.api.client.http.HttpResponse;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.http.javanet.NetHttpTransport;
import java.io.IOException;
import java.io.InputStream;

public class Network {

    static final HttpTransport HTTP_TRANSPORT = new NetHttpTransport();

    public void getRequest(String reqUrl) throws IOException {
        GenericUrl url = new GenericUrl(reqUrl);
        HttpRequest request = HTTP_TRANSPORT.createRequestFactory().buildGetRequest(url);
        HttpResponse response = request.execute();
        System.out.println(response.getStatusCode());

        InputStream is = response.getContent();
        int ch;
        while ((ch = is.read()) != -1) {
            System.out.print((char) ch);
        }
        response.disconnect();
    }
}

Why do you have to link the math library in C?

I think it's kind of arbitrary. You have to draw a line somewhere (which libraries are default and which need to be specified).

It gives you the opportunity to replace it with a different one that has the same functions, but I don't think it's very common to do so.

EDIT: (from my own comments): I think gcc does this to maintain backwards compatibility with the original cc. My guess for why cc does this is because of build time -- cc was written for machines with far less power than we have now. A lot of programs have no floating-point math and they probably took every library that wasn't commonly used out of the default. I'm guessing that the build time of the UNIX OS and the tools that go along with it were the driving force.

In ASP.NET, when should I use Session.Clear() rather than Session.Abandon()?

Only using Session.Clear() when a user logs out can pose a security hole. As the session is still valid as far as the Web Server is concerned. It is then a reasonably trivial matter to sniff, and grab the session Id, and hijack that session.

For this reason, when logging a user out it would be safer and more sensible to use Session.Abandon() so that the session is destroyed, and a new session created (even though the logout UI page would be part of the new session, the new session would not have any of the users details in it and hijacking the new session would be equivalent to having a fresh session, hence it would be mute).

Bitbucket fails to authenticate on git pull

First, edit your .git/config and remove your username from 'url'.

I had this:

url = https://[email protected]/pathto/myrepo.git

And after modification:

url = https://bitbucket.org/pathto/myrepo.git

Then try to pull (or push) and use your email and password credentials to login.

conditional Updating a list using LINQ

Try this:

li.ForEach(x => x.age = (x.name == "di") ?
                10 : (x.name == "marks") ?
                20 : (x.name == "grade") ?
                30 : 0 );

All values are updated in one line of code and you browse the List only ONE time. You have also a way to set a default value.

How can I get the number of days between 2 dates in Oracle 11g?

  • Full days between end of month and start of today, including the last day of the month:

    SELECT LAST_DAY (TRUNC(SysDate)) - TRUNC(SysDate) + 1 FROM dual
    
  • Days between using exact time:

    SELECT SysDate - TO_DATE('2018-01-01','YYYY-MM-DD') FROM dual
    

How to use android emulator for testing bluetooth application?

You can't. The emulator does not support Bluetooth, as mentioned in the SDK's docs and several other places. Android emulator does not have bluetooth capabilities".

You can only use real devices.

Emulator Limitations

The functional limitations of the emulator include:

  • No support for placing or receiving actual phone calls. However, You can simulate phone calls (placed and received) through the emulator console
  • No support for USB
  • No support for device-attached headphones
  • No support for determining SD card insert/eject
  • No support for WiFi, Bluetooth, NFC

Refer to the documentation

How to compile Go program consisting of multiple files?

New Way (Recommended):

Please take a look at this answer.

Old Way:

Supposing you're writing a program called myprog :

Put all your files in a directory like this

myproject/go/src/myprog/xxx.go

Then add myproject/go to GOPATH

And run

go install myprog

This way you'll be able to add other packages and programs in myproject/go/src if you want.

Reference : http://golang.org/doc/code.html

(this doc is always missed by newcomers, and often ill-understood at first. It should receive the greatest attention of the Go team IMO)

Stripping non printable characters from a string in python

In Python 3,

def filter_nonprintable(text):
    import itertools
    # Use characters of control category
    nonprintable = itertools.chain(range(0x00,0x20),range(0x7f,0xa0))
    # Use translate to remove all non-printable characters
    return text.translate({character:None for character in nonprintable})

See this StackOverflow post on removing punctuation for how .translate() compares to regex & .replace()

The ranges can be generated via nonprintable = (ord(c) for c in (chr(i) for i in range(sys.maxunicode)) if unicodedata.category(c)=='Cc') using the Unicode character database categories as shown by @Ants Aasma.

Dilemma: when to use Fragments vs Activities:

Almost always use fragments. If you know that the app you are building will remain very small, the extra effort of using fragments may not be worth it, so they can be left out. For larger apps, the complexity introduced is offset by the flexibility fragments provide, making it easier to justify having them in the project. Some people are very opposed to the additional complexity involved with fragments and their lifecycles, so they never use them in their projects. An issue with this approach is that there are several APIs in Android that rely on fragments, such as ViewPager and the Jetpack Navigation library. If you need to use these options in your app, then you must use fragments to get their benefits.

Excerpt From: Kristin Marsicano. “Android Programming: The Big Nerd Ranch Guide, 4th Edition.” Apple Books.

read subprocess stdout line by line

It's been a long time since I last worked with Python, but I think the problem is with the statement for line in proc.stdout, which reads the entire input before iterating over it. The solution is to use readline() instead:

#filters output
import subprocess
proc = subprocess.Popen(['python','fake_utility.py'],stdout=subprocess.PIPE)
while True:
  line = proc.stdout.readline()
  if not line:
    break
  #the real code does filtering here
  print "test:", line.rstrip()

Of course you still have to deal with the subprocess' buffering.

Note: according to the documentation the solution with an iterator should be equivalent to using readline(), except for the read-ahead buffer, but (or exactly because of this) the proposed change did produce different results for me (Python 2.5 on Windows XP).

Pyspark: Exception: Java gateway process exited before sending the driver its port number

Worked hours on this. My problem was with Java 10 installation. I uninstalled it and installed Java 8, and now Pyspark works.

Swift: declare an empty dictionary

var parking = [Dictionary < String, Double >()]

^ this adds a dictionary for a [string:double] input

Incrementing a date in JavaScript

Three options for you:

1. Using just JavaScript's Date object (no libraries):

My previous answer for #1 was wrong (it added 24 hours, failing to account for transitions to and from daylight saving time; Clever Human pointed out that it would fail with November 7, 2010 in the Eastern timezone). Instead, Jigar's answer is the correct way to do this without a library:

var tomorrow = new Date();
tomorrow.setDate(tomorrow.getDate() + 1);

This works even for the last day of a month (or year), because the JavaScript date object is smart about rollover:

_x000D_
_x000D_
var lastDayOf2015 = new Date(2015, 11, 31);_x000D_
snippet.log("Last day of 2015: " + lastDayOf2015.toISOString());_x000D_
var nextDay = new Date(+lastDayOf2015);_x000D_
var dateValue = nextDay.getDate() + 1;_x000D_
snippet.log("Setting the 'date' part to " + dateValue);_x000D_
nextDay.setDate(dateValue);_x000D_
snippet.log("Resulting date: " + nextDay.toISOString());
_x000D_
<!-- Script provides the `snippet` object, see http://meta.stackexchange.com/a/242144/134069 -->_x000D_
<script src="//tjcrowder.github.io/simple-snippets-console/snippet.js"></script>
_x000D_
_x000D_
_x000D_

(This answer is currently accepted, so I can't delete it. Before it was accepted I suggested to the OP they accept Jigar's, but perhaps they accepted this one for items #2 or #3 on the list.)

2. Using MomentJS:

var today = moment();
var tomorrow = moment(today).add(1, 'days');

(Beware that add modifies the instance you call it on, rather than returning a new instance, so today.add(1, 'days') would modify today. That's why we start with a cloning op on var tomorrow = ....)

3. Using DateJS, but it hasn't been updated in a long time:

var today = new Date(); // Or Date.today()
var tomorrow = today.add(1).day();

How to call a Python function from Node.js

I'm on node 10 and child process 1.0.2. The data from python is a byte array and has to be converted. Just another quick example of making a http request in python.

node

const process = spawn("python", ["services/request.py", "https://www.google.com"])

return new Promise((resolve, reject) =>{
    process.stdout.on("data", data =>{
        resolve(data.toString()); // <------------ by default converts to utf-8
    })
    process.stderr.on("data", reject)
})

request.py

import urllib.request
import sys

def karl_morrison_is_a_pedant():   
    response = urllib.request.urlopen(sys.argv[1])
    html = response.read()
    print(html)
    sys.stdout.flush()

karl_morrison_is_a_pedant()

p.s. not a contrived example since node's http module doesn't load a few requests I need to make

Get Date Object In UTC format in Java

You can subtract the time zone difference from now.

final Calendar calendar  = Calendar.getInstance();
final int      utcOffset = calendar.get(Calendar.ZONE_OFFSET) + calendar.get(Calendar.DST_OFFSET);
final long     tempDate  = new Date().getTime();

return new Date(tempDate - utcOffset);

Writing sqlplus output to a file

Make sure you have the access to the directory you are trying to spool. I tried to spool to root and it did not created the file (e.g c:\test.txt). You can check where you are spooling by issuing spool command.

How to use XPath in Python?

Sounds like an lxml advertisement in here. ;) ElementTree is included in the std library. Under 2.6 and below its xpath is pretty weak, but in 2.7+ much improved:

import xml.etree.ElementTree as ET
root = ET.parse(filename)
result = ''

for elem in root.findall('.//child/grandchild'):
    # How to make decisions based on attributes even in 2.6:
    if elem.attrib.get('name') == 'foo':
        result = elem.text
        break

OpenCV - Apply mask to a color image

Well, here is a solution if you want the background to be other than a solid black color. We only need to invert the mask and apply it in a background image of the same size and then combine both background and foreground. A pro of this solution is that the background could be anything (even other image).

This example is modified from Hough Circle Transform. First image is the OpenCV logo, second the original mask, third the background + foreground combined.

apply mask and get a customized background

# http://opencv-python-tutroals.readthedocs.io/en/latest/py_tutorials/py_imgproc/py_houghcircles/py_houghcircles.html
import cv2
import numpy as np

# load the image
img = cv2.imread('E:\\FOTOS\\opencv\\opencv_logo.png')
img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)

# detect circles
gray = cv2.medianBlur(cv2.cvtColor(img, cv2.COLOR_RGB2GRAY), 5)
circles = cv2.HoughCircles(gray, cv2.HOUGH_GRADIENT, 1, 20, param1=50, param2=50, minRadius=0, maxRadius=0)
circles = np.uint16(np.around(circles))

# draw mask
mask = np.full((img.shape[0], img.shape[1]), 0, dtype=np.uint8)  # mask is only 
for i in circles[0, :]:
    cv2.circle(mask, (i[0], i[1]), i[2], (255, 255, 255), -1)

# get first masked value (foreground)
fg = cv2.bitwise_or(img, img, mask=mask)

# get second masked value (background) mask must be inverted
mask = cv2.bitwise_not(mask)
background = np.full(img.shape, 255, dtype=np.uint8)
bk = cv2.bitwise_or(background, background, mask=mask)

# combine foreground+background
final = cv2.bitwise_or(fg, bk)

Note: It is better to use the opencv methods because they are optimized.

C# Telnet Library

I ended up finding MinimalistTelnet and adapted it to my uses. I ended up needing to be able to heavily modify the code due to the unique** device that I am attempting to attach to.

** Unique in this instance can be validly interpreted as brain-dead.

How to create table using select query in SQL Server?

An example statement that uses a sub-select :

select * into MyNewTable
from
(
select 
  * 
from 
[SomeOtherTablename]
where 
  EventStartDatetime >= '01/JAN/2018' 
)
) mysourcedata
;

note that the sub query must be given a name .. any name .. e.g. above example gives the subquery a name of mysourcedata. Without this a syntax error is issued in SQL*server 2012.

The database should reply with a message like: (9999 row(s) affected)

How to grab substring before a specified character jQuery or JavaScript

You could use regex as this will give you the string if it matches the requirements. The code would be something like:

const address = "1345 albany street, Bellevue WA 42344";
const regex = /[1-9][0-9]* [a-zA-Z]+ [a-zA-Z]+/;
const matchedResult = address.match(regex);

console.log(matchedResult[0]); // This will give you 1345 albany street.

So to break the code down. [1-9][0-9]* basically means the first number cannot be a zero and has to be a number between 1-9 and the next number can be any number from 0-9 and can occur zero or more times as sometimes the number is just one digit and then it matches a space. [a-zA-Z] basically matches all capital letters to small letters and has to occur one or more times and this is repeated.

Rounding a number to the nearest 5 or 10 or X

'Example: Round 499 to nearest 5. You would use the ROUND() FUNCTION.

a = inputbox("number to be rounded")
 b = inputbox("Round to nearest _______ ")


  strc = Round(A/B)
  strd = strc*B


 msgbox( a & ",  Rounded to the nearest " & b & ", is" & vbnewline & strd)

Installing OpenCV 2.4.3 in Visual C++ 2010 Express

1. Installing OpenCV 2.4.3

First, get OpenCV 2.4.3 from sourceforge.net. Its a self-extracting so just double click to start the installation. Install it in a directory, say C:\.

OpenCV self-extractor

Wait until all files get extracted. It will create a new directory C:\opencv which contains OpenCV header files, libraries, code samples, etc.

Now you need to add the directory C:\opencv\build\x86\vc10\bin to your system PATH. This directory contains OpenCV DLLs required for running your code.

Open Control PanelSystemAdvanced system settingsAdvanced Tab → Environment variables...

enter image description here

On the System Variables section, select Path (1), Edit (2), and type C:\opencv\build\x86\vc10\bin; (3), then click Ok.

On some computers, you may need to restart your computer for the system to recognize the environment path variables.

This will completes the OpenCV 2.4.3 installation on your computer.


2. Create a new project and set up Visual C++

Open Visual C++ and select FileNewProject...Visual C++Empty Project. Give a name for your project (e.g: cvtest) and set the project location (e.g: c:\projects).

New project dialog

Click Ok. Visual C++ will create an empty project.

VC++ empty project

Make sure that "Debug" is selected in the solution configuration combobox. Right-click cvtest and select PropertiesVC++ Directories.

Project property dialog

Select Include Directories to add a new entry and type C:\opencv\build\include.

Include directories dialog

Click Ok to close the dialog.

Back to the Property dialog, select Library Directories to add a new entry and type C:\opencv\build\x86\vc10\lib.

Library directories dialog

Click Ok to close the dialog.

Back to the property dialog, select LinkerInputAdditional Dependencies to add new entries. On the popup dialog, type the files below:

opencv_calib3d243d.lib
opencv_contrib243d.lib
opencv_core243d.lib
opencv_features2d243d.lib
opencv_flann243d.lib
opencv_gpu243d.lib
opencv_haartraining_engined.lib
opencv_highgui243d.lib
opencv_imgproc243d.lib
opencv_legacy243d.lib
opencv_ml243d.lib
opencv_nonfree243d.lib
opencv_objdetect243d.lib
opencv_photo243d.lib
opencv_stitching243d.lib
opencv_ts243d.lib
opencv_video243d.lib
opencv_videostab243d.lib

Note that the filenames end with "d" (for "debug"). Also note that if you have installed another version of OpenCV (say 2.4.9) these filenames will end with 249d instead of 243d (opencv_core249d.lib..etc).

enter image description here

Click Ok to close the dialog. Click Ok on the project properties dialog to save all settings.

NOTE:

These steps will configure Visual C++ for the "Debug" solution. For "Release" solution (optional), you need to repeat adding the OpenCV directories and in Additional Dependencies section, use:

opencv_core243.lib
opencv_imgproc243.lib
...

instead of:

opencv_core243d.lib
opencv_imgproc243d.lib
...

You've done setting up Visual C++, now is the time to write the real code. Right click your project and select AddNew Item...Visual C++C++ File.

Add new source file

Name your file (e.g: loadimg.cpp) and click Ok. Type the code below in the editor:

#include <opencv2/highgui/highgui.hpp>
#include <iostream>

using namespace cv;
using namespace std;

int main()
{
    Mat im = imread("c:/full/path/to/lena.jpg");
    if (im.empty()) 
    {
        cout << "Cannot load image!" << endl;
        return -1;
    }
    imshow("Image", im);
    waitKey(0);
}

The code above will load c:\full\path\to\lena.jpg and display the image. You can use any image you like, just make sure the path to the image is correct.

Type F5 to compile the code, and it will display the image in a nice window.

First OpenCV program

And that is your first OpenCV program!


3. Where to go from here?

Now that your OpenCV environment is ready, what's next?

  1. Go to the samples dir → c:\opencv\samples\cpp.
  2. Read and compile some code.
  3. Write your own code.

Running a simple shell script as a cronjob

What directory is file.txt in? cron runs jobs in your home directory, so unless your script cds somewhere else, that's where it's going to look for/create file.txt.

EDIT: When you refer to a file without specifying its full path (e.g. file.txt, as opposed to the full path /home/myUser/scripts/file.txt) in shell, it's taken that you're referring to a file in your current working directory. When you run a script (whether interactively or via crontab), the script's working directory has nothing at all to do with the location of the script itself; instead, it's inherited from whatever ran the script.

Thus, if you cd (change working directory) to the directory the script's in and then run it, file.txt will refer to a file in the same directory as the script. But if you don't cd there first, file.txt will refer to a file in whatever directory you happen to be in when you ran the script. For instance, if your home directory is /home/myUser, and you open a new shell and immediately run the script (as scripts/test.sh or /home/myUser/scripts/test.sh; ./test.sh won't work), it'll touch the file /home/myUser/file.txt because /home/myUser is your current working directory (and therefore the script's).

When you run a script from cron, it does essentially the same thing: it runs it with the working directory set to your home directory. Thus all file references in the script are taken relative to your home directory, unless the script cds somewhere else or specifies an absolute path to the file.

anaconda - graphviz - can't import after installation

I am using anaconda for the same.

I installed graphviz using conda install graphviz in anaconda prompt. and then installed pip install graphviz in the same command prompt. It worked for me.

Replace non-ASCII characters with a single space

When we use the ascii() it escapes the non-ascii characters and it doesn't change ascii characters correctly. So my main thought is, it doesn't change the ASCII characters, so I am iterating through the string and checking if the character is changed. If it changed then replacing it with the replacer, what you give.
For example: ' '(a single space) or '?' (with a question mark).

def remove(x, replacer):

     for i in x:
        if f"'{i}'" == ascii(i):
            pass
        else:
            x=x.replace(i,replacer)
     return x
remove('hái',' ')

Result: "h i" (with single space between).

Syntax : remove(str,non_ascii_replacer)
str = Here you will give the string you want to work with.
non_ascii_replacer = Here you will give the replacer which you want to replace all the non ASCII characters with.

Why doesn't JUnit provide assertNotEquals methods?

I'm coming to this party pretty late but I have found that the form:

static void assertTrue(java.lang.String message, boolean condition) 

can be made to work for most 'not equals' cases.

int status = doSomething() ; // expected to return 123
assertTrue("doSomething() returned unexpected status", status != 123 ) ;

Google Map API v3 ~ Simply Close an infowindow?

We can use infowindow.close(map); to close all info windows if you already initialize the info window using infowindow = new google.maps.InfoWindow();

Mercurial: how to amend the last commit?

Assuming that you have not yet propagated your changes, here is what you can do.

  • Add to your .hgrc:

    [extensions]
    mq =
    
  • In your repository:

    hg qimport -r0:tip
    hg qpop -a
    

    Of course you need not start with revision zero or pop all patches, for the last just one pop (hg qpop) suffices (see below).

  • remove the last entry in the .hg/patches/series file, or the patches you do not like. Reordering is possible too.

  • hg qpush -a; hg qfinish -a
  • remove the .diff files (unapplied patches) still in .hg/patches (should be one in your case).

If you don't want to take back all of your patch, you can edit it by using hg qimport -r0:tip (or similar), then edit stuff and use hg qrefresh to merge the changes into the topmost patch on your stack. Read hg help qrefresh.

By editing .hg/patches/series, you can even remove several patches, or reorder some. If your last revision is 99, you may just use hg qimport -r98:tip; hg qpop; [edit series file]; hg qpush -a; hg qfinish -a.

Of course, this procedure is highly discouraged and risky. Make a backup of everything before you do this!

As a sidenote, I've done it zillions of times on private-only repositories.

Is there a JavaScript / jQuery DOM change listener?

Another approach depending on how you are changing the div. If you are using JQuery to change a div's contents with its html() method, you can extend that method and call a registration function each time you put html into a div.

(function( $, oldHtmlMethod ){
    // Override the core html method in the jQuery object.
    $.fn.html = function(){
        // Execute the original HTML method using the
        // augmented arguments collection.

        var results = oldHtmlMethod.apply( this, arguments );
        com.invisibility.elements.findAndRegisterElements(this);
        return results;

    };
})( jQuery, jQuery.fn.html );

We just intercept the calls to html(), call a registration function with this, which in the context refers to the target element getting new content, then we pass on the call to the original jquery.html() function. Remember to return the results of the original html() method, because JQuery expects it for method chaining.

For more info on method overriding and extension, check out http://www.bennadel.com/blog/2009-Using-Self-Executing-Function-Arguments-To-Override-Core-jQuery-Methods.htm, which is where I cribbed the closure function. Also check out the plugins tutorial at JQuery's site.

Is there a way to comment out markup in an .ASPX page?

I believe you're looking for:

<%-- your markup here --%>

That is a serverside comment and will not be delivered to the client ... but it's not optional. If you need this to be programmable, then you'll want this answer :-)

Stored Procedure parameter default value - is this a constant or a variable

It has to be a constant - the value has to be computable at the time that the procedure is created, and that one computation has to provide the value that will always be used.

Look at the definition of sys.all_parameters:

default_value sql_variant If has_default_value is 1, the value of this column is the value of the default for the parameter; otherwise, NULL.

That is, whatever the default for a parameter is, it has to fit in that column.


As Alex K pointed out in the comments, you can just do:

CREATE PROCEDURE [dbo].[problemParam] 
    @StartDate INT = NULL,
    @EndDate INT = NULL
AS  
BEGIN
   SET @StartDate = COALESCE(@StartDate,CONVERT(INT,(CONVERT(CHAR(8),GETDATE()-130,112))))

provided that NULL isn't intended to be a valid value for @StartDate.


As to the blog post you linked to in the comments - that's talking about a very specific context - that, the result of evaluating GETDATE() within the context of a single query is often considered to be constant. I don't know of many people (unlike the blog author) who would consider a separate expression inside a UDF to be part of the same query as the query that calls the UDF.

How to catch curl errors in PHP

If CURLOPT_FAILONERROR is false, http errors will not trigger curl errors.

<?php
if (@$_GET['curl']=="yes") {
  header('HTTP/1.1 503 Service Temporarily Unavailable');
} else {
  $ch=curl_init($url = "http://".$_SERVER['SERVER_NAME'].$_SERVER['PHP_SELF']."?curl=yes");
  curl_setopt($ch, CURLOPT_FAILONERROR, true);
  $response=curl_exec($ch);
  $http_status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
  $curl_errno= curl_errno($ch);
  if ($http_status==503)
    echo "HTTP Status == 503 <br/>";
  echo "Curl Errno returned $curl_errno <br/>";
}

Include PHP file into HTML file

In order to get the PHP output into the HTML file you need to either

  • Change the extension of the HTML to file to PHP and include the PHP from there (simple)
  • Load your HTML file into your PHP as a kind of template (a lot of work)
  • Change your environment so it deals with HTML as if it was PHP (bad idea)

Change placeholder text

Using jquery you can do this by following code:

<input type="text" id="tbxEmail" name="Email" placeholder="Some Text"/>

$('#tbxEmail').attr('placeholder','Some New Text');

Python dict how to create key or append an element to key?

dictionary['key'] = dictionary.get('key', []) + list_to_append

align divs to the bottom of their container

The way I solved this was using flexbox. By using flexbox to layout the contents of your container div, you can have flexbox automatically distribute free space to an item above the one you want to have "stick to the bottom".

For example, say this is your container div with some other block elements inside it, and that the blue box (third one down) is a paragraph and the purple box (last one) is the one you want to have "stick to the bottom".

enter image description here

By setting this layout up with flexbox, you can set flex-grow: 1; on just the paragraph (blue box) and, if it is the only thing with flex-grow: 1;, it will be allocated ALL of the remaining space, pushing the element(s) after it to the bottom of the container like this:

enter image description here

(apologies for the terrible, quick-and-dirty graphics)

How to check if my string is equal to null?

Try,

myString!=null && myString.length()>0

Do Git tags only apply to the current branch?

We can create a tag for some past commit:

git tag [tag_name] [reference_of_commit]

eg:

git tag v1.0 5fcdb03

Need to find a max of three numbers in java

You should know more about java.lang.Math.max:

  1. java.lang.Math.max(arg1,arg2) only accepts 2 arguments but you are writing 3 arguments in your code.
  2. The 2 arguments should be double,int,long and float but your are writing String arguments in Math.max function. You need to parse them in the required type.

You code will produce compile time error because of above mismatches.

Try following updated code, that will solve your purpose:

import java.lang.Math;
import java.util.Scanner;
public class max {
    public static void main(String[] args) {
        Scanner keyboard = new Scanner(System.in);
        System.out.println("Please input 3 integers: ");
        int x = Integer.parseInt(keyboard.nextLine());
        int y = Integer.parseInt(keyboard.nextLine());
        int z = Integer.parseInt(keyboard.nextLine());
        int max = Math.max(x,y);
        if(max>y){ //suppose x is max then compare x with z to find max number
            max = Math.max(x,z);    
        }
        else{ //if y is max then compare y with z to find max number
            max = Math.max(y,z);    
        }
        System.out.println("The max of three is: " + max);
    }
} 

How do I write JSON data to a file?

You forgot the actual JSON part - data is a dictionary and not yet JSON-encoded. Write it like this for maximum compatibility (Python 2 and 3):

import json
with open('data.json', 'w') as f:
    json.dump(data, f)

On a modern system (i.e. Python 3 and UTF-8 support), you can write a nicer file with

import json
with open('data.json', 'w', encoding='utf-8') as f:
    json.dump(data, f, ensure_ascii=False, indent=4)

C++ Fatal Error LNK1120: 1 unresolved externals

I incurred this error once.

It turns out I had named my program ProgramMame.ccp instead of ProgramName.cpp

easy to do ...

Hope this may help

Visual Studio Code PHP Intelephense Keep Showing Not Necessary Error

This is really a set of configurations for your editor to understand Laravel.

If you want to configure it all manually, here is the repo. This is for both VS code and PhpStorm.

Or if you want you can download this package.(I created) recommended to install it globally.

And then just run andylaravel setupIDE. this will configure everything for you according to the fist repo.

Python Matplotlib figure title overlaps axes label when using twiny

You can use pad for this case:

ax.set_title("whatever", pad=20)

SSL: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch

SL_CTX_use_PrivateKey("/etc/nginx/ssl/file") failed (SSL: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch)

This error can happen, when the certificate private key (ssl_certificate_key, e.g. .key or .pem file) does not match the public certificate file (ssl_certificate) in your Nginx configuration (check nginx.conf or in sites-enabled/). Make sure both files are matching.

Check Nginx error logs for further details (e.g. /var/log/nginx/error.log).

Checking session if empty or not

You need to check that Session["emp_num"] is not null before trying to convert it to a string otherwise you will get a null reference exception.

I'd go with your first example - but you could make it slightly more "elegant".

There are a couple of ways, but the ones that springs to mind are:

if (Session["emp_num"] is string)
{
}

or

if (!string.IsNullOrEmpty(Session["emp_num"] as string))
{
}

This will return null if the variable doesn't exist or isn't a string.

How to get past the login page with Wget?

I use this chrome extension. It'll give you the wget command for any download link you open.

Using Mockito to mock classes with generic parameters

You could always create an intermediate class/interface that would satisfy the generic type that you are wanting to specify. For example, if Foo was an interface, you could create the following interface in your test class.

private interface FooBar extends Foo<Bar>
{
}

In situations where Foo is a non-final class, you could just extend the class with the following code and do the same thing:

public class FooBar extends Foo<Bar>
{
}

Then you could consume either of the above examples with the following code:

Foo<Bar> mockFoo = mock(FooBar.class);
when(mockFoo.getValue()).thenReturn(new Bar());

How to find a string inside a entire database?

Here are couple more free tools that can be used for this. Both work as SSMS addins.

ApexSQL Search – 100% free - searches both schema and data in tables. Has couple more useful options such as dependency tracking…

SSMS Tools pack – free for all versions except SQL 2012 – doesn’t look as advanced as previous one but has a lot of other cool features.

Change icons of checked and unchecked for Checkbox for Android

I realize this is an old question, and the OP is talking about using custom gx that aren't necessary 'checkbox'-looking, but there is a fantastic resource for generating custom colored assets here: http://kobroor.pl/

Just give it the relevant details and it spits out graphics, complete with xml resources, that you can just drop right in.

Remove Item from ArrayList

As mentioned before

iterator.remove()

is maybe the only safe way to remove list items during the loop.

For deeper understanding of items removal using the iterator, try to look at this thread

Remote origin already exists on 'git push' to a new repository

  1. git remote rm origin

  2. git remote -v It will not display any repository name

  3. git remote add origin [email protected]:username/myapp.git

  4. git push origin master It will start the process and creating the new branch. You can see your work is pushed to github.

How do I set the classpath in NetBeans?

Maven

The Answer by Bhesh Gurung is correct… unless your NetBeans project is Maven based.

Dependency

Under Maven, you add a "dependency". A dependency is a description of a library (its name & version number) you want to use from your code.

Or a dependency could be a description of a library which another library needs ("depends on"). Maven automatically handles this chain, libraries that need other libraries that then need other libraries and so on. For the mathematical-minded, perhaps the phrase "Maven resolves the transitive dependencies" makes sense.

Repository

Maven gets this related-ness information, and the libraries themselves from a Maven repository. A repository is basically an online database and collection of download files (the dependency library).

Easy to Use

Adding a dependency to a Maven-based project is really quite easy. That is the whole point to Maven, to make managing dependent libraries easy and to make building them into your project easy. To get started with adding a dependency, see this Question, Adding dependencies in Maven Netbeans and my Answer with screenshot.

enter image description here

How do you synchronise projects to GitHub with Android Studio?

In the version of Android Studio I have (0.3.2), it was as easy as using the menu.

VCS Menu > Git > Share on GitHub.

It will then ask you for your credentials, and then a name for your new repo, and that's it!

CSS flexbox not working in IE10

As Ennui mentioned, IE 10 supports the -ms prefixed version of Flexbox (IE 11 supports it unprefixed). The errors I can see in your code are:

  • You should have display: -ms-flexbox instead of display: -ms-flex
  • I think you should specify all 3 flex values, like flex: 0 1 auto to avoid ambiguity

So the final updated code is...

.flexbox form {
    display: -webkit-flex;
    display: -moz-flex;
    display: -ms-flexbox;
    display: -o-flex;
    display: flex;

    /* Direction defaults to 'row', so not really necessary to specify */
    -webkit-flex-direction: row;
    -moz-flex-direction: row;
    -ms-flex-direction: row;
    -o-flex-direction: row;
    flex-direction: row;
}

.flexbox form input[type=submit] {
    width: 31px;
}

.flexbox form input[type=text] {
    width: auto;

    /* Flex should have 3 values which is shorthand for 
       <flex-grow> <flex-shrink> <flex-basis> */
    -webkit-flex: 1 1 auto;
    -moz-flex: 1 1 auto;
    -ms-flex: 1 1 auto;
    -o-flex: 1 1 auto;
    flex: 1 1 auto;

    /* I don't think you need 'display: flex' on child elements * /
    display: -webkit-flex;
    display: -moz-flex;
    display: -ms-flex;
    display: -o-flex;
    display: flex;
    /**/
}

JPA 2.0, Criteria API, Subqueries, In Expressions

Below is the pseudo-code for using sub-query using Criteria API.

CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaQuery<Object> criteriaQuery = criteriaBuilder.createQuery();
Root<EMPLOYEE> from = criteriaQuery.from(EMPLOYEE.class);
Path<Object> path = from.get("compare_field"); // field to map with sub-query
from.fetch("name");
from.fetch("id");
CriteriaQuery<Object> select = criteriaQuery.select(from);

Subquery<PROJECT> subquery = criteriaQuery.subquery(PROJECT.class);
Root fromProject = subquery.from(PROJECT.class);
subquery.select(fromProject.get("requiredColumnName")); // field to map with main-query
subquery.where(criteriaBuilder.and(criteriaBuilder.equal("name",name_value),criteriaBuilder.equal("id",id_value)));

select.where(criteriaBuilder.in(path).value(subquery));

TypedQuery<Object> typedQuery = entityManager.createQuery(select);
List<Object> resultList = typedQuery.getResultList();

Also it definitely needs some modification as I have tried to map it according to your query. Here is a link http://www.ibm.com/developerworks/java/library/j-typesafejpa/ which explains concept nicely.

Passing struct to function

Instead of:

void addStudent(person)
{
    return;
}

try this:

void addStudent(student person)
{
    return;
}

Since you have already declared a structure called 'student' you don't necessarily have to specify so in the function implementation as in:

void addStudent(struct student person)
{
    return;
}

jQuery UI " $("#datepicker").datepicker is not a function"

If there is another library that is using the $ variable, you can do this:

var $j = jQuery.noConflict();
$j("#datepicker").datepicker();

Also make sure your javascript includes are in the correct order so the jquery core library is defined before the jquery.ui. I've had that cause issues.

How to initialize a JavaScript Date to a particular time zone

This should solve your problem, please feel free to offer fixes. This method will account also for daylight saving time for the given date.

dateWithTimeZone = (timeZone, year, month, day, hour, minute, second) => {
  let date = new Date(Date.UTC(year, month, day, hour, minute, second));

  let utcDate = new Date(date.toLocaleString('en-US', { timeZone: "UTC" }));
  let tzDate = new Date(date.toLocaleString('en-US', { timeZone: timeZone }));
  let offset = utcDate.getTime() - tzDate.getTime();

  date.setTime( date.getTime() + offset );

  return date;
};

How to use with timezone and local time:

dateWithTimeZone("America/Los_Angeles",2019,8,8,0,0,0)

Daemon Threads Explanation

Let's say you're making some kind of dashboard widget. As part of this, you want it to display the unread message count in your email box. So you make a little thread that will:

  1. Connect to the mail server and ask how many unread messages you have.
  2. Signal the GUI with the updated count.
  3. Sleep for a little while.

When your widget starts up, it would create this thread, designate it a daemon, and start it. Because it's a daemon, you don't have to think about it; when your widget exits, the thread will stop automatically.

Is it possible to format an HTML tooltip (title attribute)?

In bootstrap tooltip just use data-html="true"

Convert a number to 2 decimal places in Java

DecimalFormat df=new DecimalFormat("0.00");

Use this code to get exact two decimal points. Even if the value is 0.0 it will give u 0.00 as output.

Instead if you use:

DecimalFormat df=new DecimalFormat("#.00");  

It wont convert 0.2659 into 0.27. You will get an answer like .27.

jquery beforeunload when closing (not leaving) the page?

You can do this by using JQuery.

For example ,

<a href="your URL" id="navigate"> click here </a>

Your JQuery will be,

$(document).ready(function(){

    $('a').on('mousedown', stopNavigate);

    $('a').on('mouseleave', function () {
           $(window).on('beforeunload', function(){
                  return 'Are you sure you want to leave?';
           });
    });
});

function stopNavigate(){    
    $(window).off('beforeunload');
}

And to get the Leave message alert will be,

$(window).on('beforeunload', function(){
      return 'Are you sure you want to leave?';
});

$(window).on('unload', function(){

         logout();

});

This solution works in all browsers and I have tested it.

How to execute command stored in a variable?

$cmd would just replace the variable with it's value to be executed on command line. eval "$cmd" does variable expansion & command substitution before executing the resulting value on command line

The 2nd method is helpful when you wanna run commands that aren't flexible eg.
for i in {$a..$b}
format loop won't work because it doesn't allow variables.
In this case, a pipe to bash or eval is a workaround.

Tested on Mac OSX 10.6.8, Bash 3.2.48

Web Service vs WCF Service

Web Service is based on SOAP and return data in XML form. It support only HTTP protocol. It is not open source but can be consumed by any client that understands xml. It can be hosted only on IIS.

WCF is also based on SOAP and return data in XML form. It is the evolution of the web service(ASMX) and support various protocols like TCP, HTTP, HTTPS, Named Pipes, MSMQ. The main issue with WCF is, its tedious and extensive configuration. It is not open source but can be consumed by any client that understands xml. It can be hosted with in the applicaion or on IIS or using window service.

How to check if an object is defined?

You check if it's null in C# like this:

if(MyObject != null) {
  //do something
}

If you want to check against default (tough to understand the question on the info given) check:

if(MyObject != default(MyObject)) {
 //do something
}

Python: "Indentation Error: unindent does not match any outer indentation level"

Sorry I can't add comments as my reputation is not high enough :-/, so this will have to be an answer.

As several have commented, the code you have posted contains several (5) syntax errors (twice = instead of == and three ':' missing).

Once the syntax errors corrected I do not have any issue, be it indentation or else; of course it's impossible to see if you have mixed tabs and spaces as somebody else has suggested, which is likely your problem.

But the real point I wanted to underline is that: tabnanny IS NOT REALIABLE: you might be getting an 'indentation' error when it's actually just a syntax error.

Eg. I got it when I had added one closed parenthesis more than necessary ;-)

i += [func(a, b, [c] if True else None))]

would provoke a warning from tabnanny for the next line.

Hope this helps!

c++ compile error: ISO C++ forbids comparison between pointer and integer

A string literal is delimited by quotation marks and is of type char* not char.

Example: "hello"

So when you compare a char to a char* you will get that same compiling error.

char c = 'c';
char *p = "hello";

if(c==p)//compiling error
{
} 

To fix use a char literal which is delimited by single quotes.

Example: 'c'

How to use Servlets and Ajax?

Ajax (also AJAX) an acronym for Asynchronous JavaScript and XML) is a group of interrelated web development techniques used on the client-side to create asynchronous web applications. With Ajax, web applications can send data to, and retrieve data from, a server asynchronously Below is example code:

Jsp page java script function to submit data to servlet with two variable firstName and lastName:

function onChangeSubmitCallWebServiceAJAX()
    {
      createXmlHttpRequest();
      var firstName=document.getElementById("firstName").value;
      var lastName=document.getElementById("lastName").value;
      xmlHttp.open("GET","/AJAXServletCallSample/AjaxServlet?firstName="
      +firstName+"&lastName="+lastName,true)
      xmlHttp.onreadystatechange=handleStateChange;
      xmlHttp.send(null);

    }

Servlet to read data send back to jsp in xml format ( You could use text as well. Just you need to change response content to text and render data on javascript function.)

/**
 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
 */
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    String firstName = request.getParameter("firstName");
    String lastName = request.getParameter("lastName");

    response.setContentType("text/xml");
    response.setHeader("Cache-Control", "no-cache");
    response.getWriter().write("<details>");
    response.getWriter().write("<firstName>"+firstName+"</firstName>");
    response.getWriter().write("<lastName>"+lastName+"</lastName>");
    response.getWriter().write("</details>");
}

Jquery Chosen plugin - dynamically populate list by Ajax

The Chosen plugin does not automatically update its list of options when the OPTION elements in the DOM change. You have to send it an event to trigger the update:

Pre Chosen 1.0: $('.chzn-select').trigger("liszt:updated");

Chosen 1.0 $('.chosen-select').trigger("chosen:updated");

If you are dynamically managing the OPTION elements, then you'll have to do this whenever the OPTIONs change. The way you do this will vary - in AngularJS, try something like this:

$scope.$watch(
  function() {
    return element.find('option').map(function() { return this.value }).get().join();
  }, 
  function() {
    element.trigger('liszt:updated');
  }
 }

Keras, How to get the output of each layer?

Following looks very simple to me:

model.layers[idx].output

Above is a tensor object, so you can modify it using operations that can be applied to a tensor object.

For example, to get the shape model.layers[idx].output.get_shape()

idx is the index of the layer and you can find it from model.summary()

How to change a PG column to NULLABLE TRUE?

From the fine manual:

ALTER TABLE mytable ALTER COLUMN mycolumn DROP NOT NULL;

There's no need to specify the type when you're just changing the nullability.

Git: which is the default configured remote for branch?

You can do it more simply, guaranteeing that your .gitconfig is left in a meaningful state:

Using Git version v1.8.0 and above

git push -u hub master when pushing, or:
git branch -u hub/master

OR

(This will set the remote for the currently checked-out branch to hub/master)
git branch --set-upstream-to hub/master

OR

(This will set the remote for the branch named branch_name to hub/master)
git branch branch_name --set-upstream-to hub/master

If you're using v1.7.x or earlier

you must use --set-upstream:
git branch --set-upstream master hub/master

What is the Java equivalent of PHP var_dump?

It is not quite as baked-in in Java, so you don't get this for free. It is done with convention rather than language constructs. In all data transfer classes (and maybe even in all classes you write...), you should implement a sensible toString method. So here you need to override toString() in your Person class and return the desired state.

There are utilities available that help with writing a good toString method, or most IDEs have an automatic toString() writing shortcut.

How can I dynamically set the position of view in Android?

You can try to use the following methods, if you're using HoneyComb Sdk(API Level 11).

view.setX(float x);

Parameter x is the visual x position of this view.

view.setY(float y);

Parameter y is the visual y position of this view.

I hope it will be helpful to you. :)

Resolving MSB3247 - Found conflicts between different versions of the same dependent assembly

Mike Hadlow has posted a little console app called AsmSpy that rather nicely lists each assembly's references:

Reference: System.Net.Http.Formatting
        4.0.0.0 by Shared.MessageStack
        4.0.0.0 by System.Web.Http

Reference: System.Net.Http
        2.0.0.0 by Shared.MessageStack
        2.0.0.0 by System.Net.Http.Formatting
        4.0.0.0 by System.Net.Http.WebRequest
        2.0.0.0 by System.Web.Http.Common
        2.0.0.0 by System.Web.Http
        2.0.0.0 by System.Web.Http.WebHost

This is a much quicker way to get to the bottom of the warning MSB3247, than to depend on the MSBuild output.

'str' object does not support item assignment in Python

Hi you should try the string split method:

i = "Hello world"
output = i.split()

j = 'is not enough'

print 'The', output[1], j

Default value for field in Django model

You can also use a callable in the default field, such as:

b = models.CharField(max_length=7, default=foo)

And then define the callable:

def foo():
    return 'bar'

CSS - Make divs align horizontally

Float: left, display: inline-block will both fail to align the elements horizontally if they exceed the width of the container.

It's important to note that the container should not wrap if the elements MUST display horizontally: white-space: nowrap

Address in mailbox given [] does not comply with RFC 2822, 3.6.2. when email is in a variable

(I'm using SwiftMailer in PHP)

I was getting an error like that when I was accidentally sending a string for $email

$email = "[email protected] <Some One>";

When what I meant to be sending was

$email = Array("[email protected]"=>"Some One");

I was accidentally running it through a stringify function that I was using for logging, so once I started sending the array again, the error went away.

How do you round UP a number in Python?

I'm basically a beginner at Python, but if you're just trying to round up instead of down why not do:

round(integer) + 1

Is true == 1 and false == 0 in JavaScript?

Use === to equate the variables instead of ==.

== checks if the value of the variables is similar

=== checks if the value of the variables and the type of the variables are similar

Notice how

if(0===false) {
    document.write("oh!!! that's true");
}?

and

if(0==false) {
    document.write("oh!!! that's true");
}?

give different results

How to watch for form changes in Angular

To complete a bit more previous great answers, you need to be aware that forms leverage observables to detect and handle value changes. It's something really important and powerful. Both Mark and dfsq described this aspect in their answers.

Observables allow not only to use the subscribe method (something similar to the then method of promises in Angular 1). You can go further if needed to implement some processing chains for updated data in forms.

I mean you can specify at this level the debounce time with the debounceTime method. This allows you to wait for an amount of time before handling the change and correctly handle several inputs:

this.form.valueChanges
    .debounceTime(500)
    .subscribe(data => console.log('form changes', data));

You can also directly plug the processing you want to trigger (some asynchronous one for example) when values are updated. For example, if you want to handle a text value to filter a list based on an AJAX request, you can leverage the switchMap method:

this.textValue.valueChanges
    .debounceTime(500)
    .switchMap(data => this.httpService.getListValues(data))
    .subscribe(data => console.log('new list values', data));

You even go further by linking the returned observable directly to a property of your component:

this.list = this.textValue.valueChanges
    .debounceTime(500)
    .switchMap(data => this.httpService.getListValues(data))
    .subscribe(data => console.log('new list values', data));

and display it using the async pipe:

<ul>
  <li *ngFor="#elt of (list | async)">{{elt.name}}</li>
</ul>

Just to say that you need to think the way to handle forms differently in Angular2 (a much more powerful way ;-)).

Hope it helps you, Thierry

Redirecting unauthorized controller in ASP.NET MVC

Would have left this as a comment but I need more rep, anyways I just wanted to mention to Nicholas Peterson that perhaps passing the second argument to the Redirect call to tell it to end the response would have worked. Not the most graceful way to handle this but it does in fact work.

So

filterContext.RequestContext.HttpContext.Response.Redirect("/Login", true);

instead of

filterContext.RequestContext.HttpContext.Response.Redirect("/Login);

So you'd have this in your controller:

 protected override void OnAuthorization(AuthorizationContext filterContext)
 {
      if(!User.IsInRole("Admin")
      {
          base.OnAuthorization(filterContext);
          filterContext.RequestContext.HttpContext.Response.Redirect("/Login", true);
      }
 }

Counting the number of elements in array

Just use the length filter on the whole array. It works on more than just strings:

{{ notcount|length }}

How to prevent rm from reporting that a file was not found?

Yes, -f is the most suitable option for this.

How to get access to job parameters from ItemReader, in Spring Batch?

Complement with an additional example, you can access all job parameters in JavaConfig class:

@Bean
@StepScope
public ItemStreamReader<GenericMessage> reader(@Value("#{jobParameters}") Map<String,Object> jobParameters){
          ....
}

Java BigDecimal: Round to the nearest whole value

You want

round(new MathContext(0));  // or perhaps another math context with rounding mode HALF_UP

How to check if a String contains only ASCII?

You can do it with java.nio.charset.Charset.

import java.nio.charset.Charset;

public class StringUtils {

  public static boolean isPureAscii(String v) {
    return Charset.forName("US-ASCII").newEncoder().canEncode(v);
    // or "ISO-8859-1" for ISO Latin 1
    // or StandardCharsets.US_ASCII with JDK1.7+
  }

  public static void main (String args[])
    throws Exception {

     String test = "Réal";
     System.out.println(test + " isPureAscii() : " + StringUtils.isPureAscii(test));
     test = "Real";
     System.out.println(test + " isPureAscii() : " + StringUtils.isPureAscii(test));

     /*
      * output :
      *   Réal isPureAscii() : false
      *   Real isPureAscii() : true
      */
  }
}

Detect non-ASCII character in a String

Extract Data from PDF and Add to Worksheet

This doesn't seem to work with the Adobe Type library. As soon as it gets to Open, I get a 429 error. Acrobat works fine though...

Java string to date conversion

That's the hard way, and those java.util.Date setter methods have been deprecated since Java 1.1 (1997). Simply format the date using SimpleDateFormat using a format pattern matching the input string.

In your specific case of "January 2, 2010" as the input string:

  1. "January" is the full text month, so use the MMMM pattern for it
  2. "2" is the short day-of-month, so use the d pattern for it.
  3. "2010" is the 4-digit year, so use the yyyy pattern for it.
String string = "January 2, 2010";
DateFormat format = new SimpleDateFormat("MMMM d, yyyy", Locale.ENGLISH);
Date date = format.parse(string);
System.out.println(date); // Sat Jan 02 00:00:00 GMT 2010

Note the importance of the explicit Locale argument. If you omit it, then it will use the default locale which is not necessarily English as used in the month name of the input string. If the locale doesn't match with the input string, then you would confusingly get a java.text.ParseException even though when the format pattern seems valid.

Here's an extract of relevance from the javadoc, listing all available format patterns:

Letter Date or Time Component Presentation Examples
G Era designator Text AD
y Year Year 1996; 96
Y Week year Year 2009; 09
M/L Month in year Month July; Jul; 07
w Week in year Number 27
W Week in month Number 2
D Day in year Number 189
d Day in month Number 10
F Day of week in month Number 2
E Day in week Text Tuesday; Tue
u Day number of week Number 1
a Am/pm marker Text PM
H Hour in day (0-23) Number 0
k Hour in day (1-24) Number 24
K Hour in am/pm (0-11) Number 0
h Hour in am/pm (1-12) Number 12
m Minute in hour Number 30
s Second in minute Number 55
S Millisecond Number 978
z Time zone General time zone Pacific Standard Time; PST; GMT-08:00
Z Time zone RFC 822 time zone -0800
X Time zone ISO 8601 time zone -08; -0800; -08:00

Note that the patterns are case sensitive and that text based patterns of four characters or more represent the full form; otherwise a short or abbreviated form is used if available. So e.g. MMMMM or more is unnecessary.

Here are some examples of valid SimpleDateFormat patterns to parse a given string to date:

Input string Pattern
2001.07.04 AD at 12:08:56 PDT yyyy.MM.dd G 'at' HH:mm:ss z
Wed, Jul 4, '01 EEE, MMM d, ''yy
12:08 PM h:mm a
12 o'clock PM, Pacific Daylight Time hh 'o''clock' a, zzzz
0:08 PM, PDT K:mm a, z
02001.July.04 AD 12:08 PM yyyyy.MMMM.dd GGG hh:mm aaa
Wed, 4 Jul 2001 12:08:56 -0700 EEE, d MMM yyyy HH:mm:ss Z
010704120856-0700 yyMMddHHmmssZ
2001-07-04T12:08:56.235-0700 yyyy-MM-dd'T'HH:mm:ss.SSSZ
2001-07-04T12:08:56.235-07:00 yyyy-MM-dd'T'HH:mm:ss.SSSXXX
2001-W27-3 YYYY-'W'ww-u

An important note is that SimpleDateFormat is not thread safe. In other words, you should never declare and assign it as a static or instance variable and then reuse it from different methods/threads. You should always create it brand new within the method local scope.


Java 8 update

If you happen to be on Java 8 or newer, then use DateTimeFormatter (also here, click the link to see all predefined formatters and available format patterns; the tutorial is available here). This new API is inspired by JodaTime.

String string = "January 2, 2010";
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("MMMM d, yyyy", Locale.ENGLISH);
LocalDate date = LocalDate.parse(string, formatter);
System.out.println(date); // 2010-01-02

Note: if your format pattern happens to contain the time part as well, then use LocalDateTime#parse(text, formatter) instead of LocalDate#parse(text, formatter). And, if your format pattern happens to contain the time zone as well, then use ZonedDateTime#parse(text, formatter) instead.

Here's an extract of relevance from the javadoc, listing all available format patterns:

Symbol Meaning Presentation Examples
G era text AD; Anno Domini; A
u year year 2004; 04
y year-of-era year 2004; 04
D day-of-year number 189
M/L month-of-year number/text 7; 07; Jul; July; J
d day-of-month number 10
Q/q quarter-of-year number/text 3; 03; Q3; 3rd quarter
Y week-based-year year 1996; 96
w week-of-week-based-year number 27
W week-of-month number 4
E day-of-week text Tue; Tuesday; T
e/c localized day-of-week number/text 2; 02; Tue; Tuesday; T
F week-of-month number 3
a am-pm-of-day text PM
h clock-hour-of-am-pm (1-12) number 12
K hour-of-am-pm (0-11) number 0
k clock-hour-of-am-pm (1-24) number 0
H hour-of-day (0-23) number 0
m minute-of-hour number 30
s second-of-minute number 55
S fraction-of-second fraction 978
A milli-of-day number 1234
n nano-of-second number 987654321
N nano-of-day number 1234000000
V time-zone ID zone-id America/Los_Angeles; Z; -08:30
z time-zone name zone-name Pacific Standard Time; PST
O localized zone-offset offset-O GMT+8; GMT+08:00; UTC-08:00;
X zone-offset 'Z' for zero offset-X Z; -08; -0830; -08:30; -083015; -08:30:15;
x zone-offset offset-x +0000; -08; -0830; -08:30; -083015; -08:30:15;
Z zone-offset offset-Z +0000; -0800; -08:00;

Do note that it has several predefined formatters for the more popular patterns. So instead of e.g. DateTimeFormatter.ofPattern("EEE, d MMM yyyy HH:mm:ss Z", Locale.ENGLISH);, you could use DateTimeFormatter.RFC_1123_DATE_TIME. This is possible because they are, on the contrary to SimpleDateFormat, thread safe. You could thus also define your own, if necessary.

For a particular input string format, you don't need to use an explicit DateTimeFormatter: a standard ISO 8601 date, like 2016-09-26T17:44:57Z, can be parsed directly with LocalDateTime#parse(text) as it already uses the ISO_LOCAL_DATE_TIME formatter. Similarly, LocalDate#parse(text) parses an ISO date without the time component (see ISO_LOCAL_DATE), and ZonedDateTime#parse(text) parses an ISO date with an offset and time zone added (see ISO_ZONED_DATE_TIME).

How to call a asp:Button OnClick event using JavaScript?

If you're open to using jQuery:

<script type="text/javascript">
 function fncsave()
 {
    $('#<%= savebtn.ClientID %>').click();
 }
</script>

Also, if you are using .NET 4 or better you can make the ClientIDMode == static and simplify the code:

<script type="text/javascript">
 function fncsave()
 {
    $("#savebtn").click();
 }
</script>

Reference: MSDN Article for Control.ClientIDMode

Troubleshooting BadImageFormatException

Background

We started getting this today when we switched our WCF service from AnyCPU to x64 on a Windows 2012 R2 server running IIS 6.2.

First we checked the only referenced assembly 10 times, to ensure it was not actually an x86 dll. Next we checked the application pool many times to ensure it was not enabling 32 bit applications.

On a whim I tried toggling the setting. It turns out the application pools in IIS were defaulting to an Enable 32-Bit Applications value of False, but IIS was ignoring it on our server for some reason and always ran our service in x86 mode.

Solution

  • Select the app pool.
  • Choose Set Application Pool Defaults... or Advanced Settings....
  • Change Enable 32-Bit Applications to True.
  • Click OK.
  • Choose Set Application Pool Defaults... or Advanced Settings... again.
  • Change Enable 32-Bit Applications back to False.
  • Click OK.

How to get changes from another branch

git fetch origin our-team

or

git pull origin our-team

but first you should make sure that you already on the branch you want to update to (featurex).

Filtering a pyspark dataframe using isin by exclusion

Also could be like this

df.filter(col('bar').isin(['a','b']) == False).show()

How to create and write to a txt file using VBA

Open ThisWorkbook.Path & "\template.txt" For Output As #1
Print #1, strContent
Close #1

More Information:

How to keep a VMWare VM's clock in sync?

When installing VMware Tools on a Windows Guest, “Time Synchronisation” is not enabled by default. However – “best practise” is to enable time synch on Windows Guests.

There a several ways to do this from outside the VM, but I wanted to find a way to enable time sync from within the guest itself either on or after tools install.

Surprisingly, this wasn’t quite as straightforward as I expected. (I assumed it would be posible to set this as a parameter / config option during tools install)

After a bit of searching I found a way to do this in a VMware article called “Using the VMware Tools Command-Line Interface“.

So, if time sync is disabled, you can enable it by running the following command line in the guest:

      VMwareService.exe –cmd “vmx.set_option synctime 0 1"

Additional Notes

For some (IMHO stupid) reason, this utility requires you to specify the current as well as the new value

0 = disabled 1 = enabled

So – if you run this command on a machine which has this already set, you will get an error saying – “Invalid old value“. Obviously you can “ignore” this error when run (so not a huge deal) but the current design seems a bit dumb. IMHO it would be much more sensible if you could simply specify the value you want to set and not require the current value to be specified.

i.e. VMwareService.exe –cmd “vmx.set_option synctime <0|1>”

How to fetch data from local JSON file on react native?

maybe you could use AsyncStorage setItem and getItem...and store the data as string, then use the json parser for convert it again to json...

jQuery: Change button text on click

$('.SeeMore2').click(function(){
    var $this = $(this);
    $this.toggleClass('SeeMore2');
    if($this.hasClass('SeeMore2')){
        $this.text('See More');         
    } else {
        $this.text('See Less');
    }
});

This should do it. You have to make sure you toggle the correct class and take out the "." from the hasClass

http://jsfiddle.net/V4u5X/2/

How exactly does __attribute__((constructor)) work?

.init/.fini isn't deprecated. It's still part of the the ELF standard and I'd dare say it will be forever. Code in .init/.fini is run by the loader/runtime-linker when code is loaded/unloaded. I.e. on each ELF load (for example a shared library) code in .init will be run. It's still possible to use that mechanism to achieve about the same thing as with __attribute__((constructor))/((destructor)). It's old-school but it has some benefits.

.ctors/.dtors mechanism for example require support by system-rtl/loader/linker-script. This is far from certain to be available on all systems, for example deeply embedded systems where code executes on bare metal. I.e. even if __attribute__((constructor))/((destructor)) is supported by GCC, it's not certain it will run as it's up to the linker to organize it and to the loader (or in some cases, boot-code) to run it. To use .init/.fini instead, the easiest way is to use linker flags: -init & -fini (i.e. from GCC command line, syntax would be -Wl -init my_init -fini my_fini).

On system supporting both methods, one possible benefit is that code in .init is run before .ctors and code in .fini after .dtors. If order is relevant that's at least one crude but easy way to distinguish between init/exit functions.

A major drawback is that you can't easily have more than one _init and one _fini function per each loadable module and would probably have to fragment code in more .so than motivated. Another is that when using the linker method described above, one replaces the original _init and _fini default functions (provided by crti.o). This is where all sorts of initialization usually occur (on Linux this is where global variable assignment is initialized). A way around that is described here

Notice in the link above that a cascading to the original _init() is not needed as it's still in place. The call in the inline assembly however is x86-mnemonic and calling a function from assembly would look completely different for many other architectures (like ARM for example). I.e. code is not transparent.

.init/.fini and .ctors/.detors mechanisms are similar, but not quite. Code in .init/.fini runs "as is". I.e. you can have several functions in .init/.fini, but it is AFAIK syntactically difficult to put them there fully transparently in pure C without breaking up code in many small .so files.

.ctors/.dtors are differently organized than .init/.fini. .ctors/.dtors sections are both just tables with pointers to functions, and the "caller" is a system-provided loop that calls each function indirectly. I.e. the loop-caller can be architecture specific, but as it's part of the system (if it exists at all i.e.) it doesn't matter.

The following snippet adds new function pointers to the .ctors function array, principally the same way as __attribute__((constructor)) does (method can coexist with __attribute__((constructor))).

#define SECTION( S ) __attribute__ ((section ( S )))
void test(void) {
   printf("Hello\n");
}
void (*funcptr)(void) SECTION(".ctors") =test;
void (*funcptr2)(void) SECTION(".ctors") =test;
void (*funcptr3)(void) SECTION(".dtors") =test;

One can also add the function pointers to a completely different self-invented section. A modified linker script and an additional function mimicking the loader .ctors/.dtors loop is needed in such case. But with it one can achieve better control over execution order, add in-argument and return code handling e.t.a. (In a C++ project for example, it would be useful if in need of something running before or after global constructors).

I'd prefer __attribute__((constructor))/((destructor)) where possible, it's a simple and elegant solution even it feels like cheating. For bare-metal coders like myself, this is just not always an option.

Some good reference in the book Linkers & loaders.

Enabling error display in PHP via htaccess only

This works for me (reference):

# PHP error handling for production servers
# Disable display of startup errors
php_flag display_startup_errors off

# Disable display of all other errors
php_flag display_errors off

# Disable HTML markup of errors
php_flag html_errors off

# Enable logging of errors
php_flag log_errors on

# Disable ignoring of repeat errors
php_flag ignore_repeated_errors off

# Disable ignoring of unique source errors
php_flag ignore_repeated_source off

# Enable logging of PHP memory leaks
php_flag report_memleaks on

# Preserve most recent error via php_errormsg
php_flag track_errors on

# Disable formatting of error reference links
php_value docref_root 0

# Disable formatting of error reference links
php_value docref_ext 0

# Specify path to PHP error log
php_value error_log /home/path/public_html/domain/PHP_errors.log

# Specify recording of all PHP errors
# [see footnote 3] # php_value error_reporting 999999999
php_value error_reporting -1

# Disable max error string length
php_value log_errors_max_len 0

# Protect error log by preventing public access
<Files PHP_errors.log>
 Order allow,deny
 Deny from all
 Satisfy All
</Files>

Are members of a C++ struct initialized to 0 by default?

They are not null if you don't initialize the struct.

Snapshot s; // receives no initialization
Snapshot s = {}; // value initializes all members

The second will make all members zero, the first leaves them at unspecified values. Note that it is recursive:

struct Parent { Snapshot s; };
Parent p; // receives no initialization
Parent p = {}; // value initializes all members

The second will make p.s.{x,y} zero. You cannot use these aggregate initializer lists if you've got constructors in your struct. If that is the case, you will have to add proper initalization to those constructors

struct Snapshot {
    int x;
    double y;
    Snapshot():x(0),y(0) { }
    // other ctors / functions...
};

Will initialize both x and y to 0. Note that you can use x(), y() to initialize them disregarding of their type: That's then value initialization, and usually yields a proper initial value (0 for int, 0.0 for double, calling the default constructor for user defined types that have user declared constructors, ...). This is important especially if your struct is a template.

jQuery.each - Getting li elements inside an ul

Given an answer as high voted and views. I did find the answer with mixed of here and other links.

I have a scenario where all patient-related menu is disabled if a patient is not selected. (Refer link - how to disable a li tag using JavaScript)

//css
.disabled{
    pointer-events:none;
    opacity:0.4;
}
// jqvery
$("li a").addClass('disabled');
// remove .disabled when you are done

So rather than write long code, I found an interesting solution via CSS.

_x000D_
_x000D_
$(document).ready(function () {_x000D_
 var PatientId ; _x000D_
 //var PatientId =1;  //remove to test enable i.e. patient selected_x000D_
 if (typeof PatientId == "undefined" || PatientId == "" || PatientId == 0 || PatientId == null) {_x000D_
  console.log(PatientId);_x000D_
  $("#dvHeaderSubMenu a").each(function () {   _x000D_
   $(this).addClass('disabled');_x000D_
  });  _x000D_
  return;_x000D_
 }_x000D_
})
_x000D_
.disabled{_x000D_
    pointer-events:none;_x000D_
    opacity:0.4;_x000D_
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
_x000D_
<div id="dvHeaderSubMenu">_x000D_
     <ul class="m-nav m-nav--inline pull-right nav-sub">_x000D_
      <li class="m-nav__item">_x000D_
       <a href="#" onclick="console.log('PatientMenu Clicked')" >_x000D_
        <i class="m-nav__link-icon fa fa-tachometer"></i>_x000D_
        Overview_x000D_
       </a>_x000D_
      </li>_x000D_
_x000D_
      <li class="m-nav__item active">_x000D_
       <a href="#" onclick="console.log('PatientMenu Clicked')" >_x000D_
        <i class="m-nav__link-icon fa fa-user"></i>_x000D_
        Personal_x000D_
       </a>_x000D_
      </li>_x000D_
            <li class="m-nav__item m-dropdown m-dropdown--inline m-dropdown--arrow" data-dropdown-toggle="hover">_x000D_
       <a href="#" class="m-dropdown__toggle dropdown-toggle" onclick="console.log('PatientMenu Clicked')">_x000D_
        <i class="m-nav__link-icon flaticon-medical-8"></i>_x000D_
        Insurance Claim_x000D_
       </a>_x000D_
       <div class="m-dropdown__wrapper">_x000D_
        <span class="m-dropdown__arrow m-dropdown__arrow--left"></span>_x000D_
        _x000D_
           <ul class="m-nav">_x000D_
            <li class="m-nav__item">_x000D_
             <a href="#" class="m-nav__link" onclick="console.log('PatientMenu Clicked')" >_x000D_
              <i class="m-nav__link-icon flaticon-toothbrush-1"></i>_x000D_
              <span class="m-nav__link-text">_x000D_
               Primary_x000D_
              </span>_x000D_
             </a>_x000D_
            </li>_x000D_
            <li class="m-nav__item">_x000D_
             <a href="#" class="m-nav__link" onclick="console.log('PatientMenu Clicked')">_x000D_
              <i class="m-nav__link-icon flaticon-interface"></i>_x000D_
              <span class="m-nav__link-text">_x000D_
               Secondary_x000D_
              </span>_x000D_
             </a>_x000D_
            </li>_x000D_
            <li class="m-nav__item">_x000D_
             <a href="#" class="m-nav__link" onclick="console.log('PatientMenu Clicked')">_x000D_
              <i class="m-nav__link-icon flaticon-healthy"></i>_x000D_
              <span class="m-nav__link-text">_x000D_
               Medical_x000D_
              </span>_x000D_
             </a>_x000D_
            </li>_x000D_
           </ul>_x000D_
          _x000D_
       _x000D_
      </li>_x000D_
     </ul>            _x000D_
</div>
_x000D_
_x000D_
_x000D_

Gradient of n colors ranging from color 1 and color 2

colorRampPalette could be your friend here:

colfunc <- colorRampPalette(c("black", "white"))
colfunc(10)
# [1] "#000000" "#1C1C1C" "#383838" "#555555" "#717171" "#8D8D8D" "#AAAAAA"
# [8] "#C6C6C6" "#E2E2E2" "#FFFFFF"

And just to show it works:

plot(rep(1,10),col=colfunc(10),pch=19,cex=3)

enter image description here

MVC 3 file upload and model binding

If you won't always have images posting to your action, you can do something like this:

[HttpPost]
public ActionResult Uploadfile(Container container, HttpPostedFileBase file) 
{
    //do container stuff

    if (Request.Files != null)
    {
        foreach (string requestFile in Request.Files)
        {
            HttpPostedFileBase file = Request.Files[requestFile]; 
            if (file.ContentLength > 0)
            {
                string fileName = Path.GetFileName(file.FileName);
                string directory = Server.MapPath("~/App_Data/uploads/");
                if (!Directory.Exists(directory))
                {
                    Directory.CreateDirectory(directory);
                }
                string path = Path.Combine(directory, fileName);
                file.SaveAs(path);
            }
        }
    }

} 

Unable to install packages in latest version of RStudio and R Version.3.1.1

Most of the time @cer solution works but if in case its not working then try installing it in base R (NOT in R studio). As R studio runs base R executable in background so new package will be available in R studio as well. [my experience in macOS]

Fixed size div?

This is a fairly trivial effect to accomplish. One way to achieve this is to simply place floated div elements within a common parent container, and set their width and height. In order to clear the floated elements, we set the overflow property of the parent.

<div class="container">
    <div class="cube">do</div>
    <div class="cube">ray</div>
    <div class="cube">me</div>
    <div class="cube">fa</div>
    <div class="cube">so</div>
    <div class="cube">la</div>
    <div class="cube">te</div>
    <div class="cube">do</div>
</div>

The CSS resembles the strategy outlined in the first paragraph above:

.container {
    width: 450px;
    overflow: auto;
}

.cube {
    float: left;
    width: 150px; 
    height: 150px;
}

You can see the end result here: http://jsfiddle.net/Qjum2/2/

Browsers that support pseudo elements provide an alternative way to clear:

.container::after {
    content: "";
    clear: both;
    display: block;
}

You can see the results here: http://jsfiddle.net/Qjum2/3/

I hope this helps.

use "netsh wlan set hostednetwork ..." to create a wifi hotspot and the authentication can't work correctly

It's a bit of a guess but could the quotes around happy be the problem? There have been some problems in the past where Android would either add or not recognize quotes around an SSID. Try setting up the hosted network connection again, but without the quotes that we see in the output for netsh wlan show hostednetwork.

Could not find module FindOpenCV.cmake ( Error in configuration process)

I had the same error, I use windows. I add "C:\opencv\build" (opencv folder) to path at the control pannel. So, That's Ok!!

Downloading MySQL dump from command line

Just type mysqldump or mysqldump --help in your cmd will show how to use

Here is my cmd result

C:\Program Files\MySQL\MySQL Server 5.0\bin>mysqldump
Usage: mysqldump [OPTIONS] database [tables]
OR     mysqldump [OPTIONS] --databases [OPTIONS] DB1 [DB2 DB3...]
OR     mysqldump [OPTIONS] --all-databases [OPTIONS]
For more options, use mysqldump --help

Ruby Arrays: select(), collect(), and map()

It looks like details is an array of hashes. So item inside of your block will be the whole hash. Therefore, to check the :qty key, you'd do something like the following:

details.select{ |item| item[:qty] != "" }

That will give you all items where the :qty key isn't an empty string.

official select documentation

Increment a database field by 1

You didn't say what you're trying to do, but you hinted at it well enough in the comments to the other answer. I think you're probably looking for an auto increment column

create table logins (userid int auto_increment primary key, 
  username varchar(30), password varchar(30));

then no special code is needed on insert. Just

insert into logins (username, password) values ('user','pass');

The MySQL API has functions to tell you what userid was created when you execute this statement in client code.

How do you turn a Mongoose document into a plain object?

The lean option tells Mongoose to skip hydrating the result documents. This makes queries faster and less memory intensive, but the result documents are plain old JavaScript objects (POJOs), not Mongoose documents.

const leanDoc = await MyModel.findOne().lean();

not necessary to use JSON.parse() method

How can I sort a dictionary by key?

Simply:

d = {2:3, 1:89, 4:5, 3:0}
sd = sorted(d.items())

for k,v in sd:
    print k, v

Output:

1 89
2 3
3 0
4 5

How to convert unix timestamp to calendar date moment.js

Might be a little late but for new issues like this I use this code:

moment(timestamp, 'X').format('lll');

You can change the format to match your needs and also add timezone like this:

moment(timestamp, 'X').tz(timezone).format('lll');

Python naming conventions for modules

I know my solution is not very popular from the pythonic point of view, but I prefer to use the Java approach of one module->one class, with the module named as the class. I do understand the reason behind the python style, but I am not too fond of having a very large file containing a lot of classes. I find it difficult to browse, despite folding.

Another reason is version control: having a large file means that your commits tend to concentrate on that file. This can potentially lead to a higher quantity of conflicts to be resolved. You also loose the additional log information that your commit modifies specific files (therefore involving specific classes). Instead you see a modification to the module file, with only the commit comment to understand what modification has been done.

Summing up, if you prefer the python philosophy, go for the suggestions of the other posts. If you instead prefer the java-like philosophy, create a Nib.py containing class Nib.

.NET / C# - Convert char[] to string

One other way:

char[] chars = {'a', ' ', 's', 't', 'r', 'i', 'n', 'g'};
string s = string.Join("", chars);
//we get "a string"
// or for fun:
string s = string.Join("_", chars);
//we get "a_ _s_t_r_i_n_g"

How do I convert struct System.Byte byte[] to a System.IO.Stream object in C#?

If you are getting an error with the other MemoryStream examples here, then you need to set the Position to 0.

public static Stream ToStream(this bytes[] bytes) 
{
    return new MemoryStream(bytes) 
    {
        Position = 0
    };
}

Tomcat 8 is not able to handle get request with '|' in query parameters?

Adding "relaxedQueryChars" attribute to the server.xml worked for me :

<Connector connectionTimeout="20000" port="8080" protocol="HTTP/1.1" redirectPort="443" URIEncoding="UTF-8" relaxedQueryChars="[]|{}^&#x5c;&#x60;&quot;&lt;&gt;"/>

Android ListView Selector Color

The list selector drawable is a StateListDrawable — it contains reference to multiple drawables for each state the list can be, like selected, focused, pressed, disabled...

While you can retrieve the drawable using getSelector(), I don't believe you can retrieve a specific Drawable from a StateListDrawable, nor does it seem possible to programmatically retrieve the colour directly from a ColorDrawable anyway.

As for setting the colour, you need a StateListDrawable as described above. You can set this on your list using the android:listSelector attribute, defining the drawable in XML like this:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:state_enabled="false" android:state_focused="true"
        android:drawable="@drawable/item_disabled" />
  <item android:state_pressed="true"
        android:drawable="@drawable/item_pressed" />
  <item android:state_focused="true"
        android:drawable="@drawable/item_focused" />
</selector>

Adding to an ArrayList Java

Array list can be implemented by the following code:

Arraylist<String> list = new ArrayList<String>();
list.add(value1);
list.add(value2);
list.add(value3);
list.add(value4);

What is %0|%0 and how does it work?

This is the Windows version of a fork bomb.

%0 is the name of the currently executing batch file. A batch file that contains just this line:

%0|%0

Is going to recursively execute itself forever, quickly creating many processes and slowing the system down.

This is not a bug in windows, it is just a very stupid thing to do in a batch file.

Is it possible to import modules from all files in a directory, using a wildcard?

If you are using webpack. This imports files automatically and exports as api namespace.

So no need to update on every file addition.

import camelCase from "lodash-es";
const requireModule = require.context("./", false, /\.js$/); // 
const api = {};

requireModule.keys().forEach(fileName => {
  if (fileName === "./index.js") return;
  const moduleName = camelCase(fileName.replace(/(\.\/|\.js)/g, ""));
  api[moduleName] = {
    ...requireModule(fileName).default
  };
});

export default api;

For Typescript users;

import { camelCase } from "lodash-es"
const requireModule = require.context("./folderName", false, /\.ts$/)

interface LooseObject {
  [key: string]: any
}

const api: LooseObject = {}

requireModule.keys().forEach(fileName => {
  if (fileName === "./index.ts") return
  const moduleName = camelCase(fileName.replace(/(\.\/|\.ts)/g, ""))
  api[moduleName] = {
    ...requireModule(fileName).default,
  }
})

export default api

Getting value of select (dropdown) before change

Combine the focus event with the change event to achieve what you want:

(function () {
    var previous;

    $("select").on('focus', function () {
        // Store the current value on focus and on change
        previous = this.value;
    }).change(function() {
        // Do something with the previous value after the change
        alert(previous);

        // Make sure the previous value is updated
        previous = this.value;
    });
})();

Working example: http://jsfiddle.net/x5PKf/766

The server response was: 5.7.0 Must issue a STARTTLS command first. i16sm1806350pag.18 - gsmtp

If you are passing (like me) all the parameters like port, username, password through a system and you are not allow to modify the code, then you can do that easy change on the web.config:

<system.net>
  <mailSettings>
    <smtp>
      <network enableSsl="true"/>
    </smtp>
  </mailSettings>
</system.net>

How to create strings containing double quotes in Excel formulas?

Returning an empty or zero-length string (e.g. "") to make a cell appear blank is a common practise in a worksheet formula but recreating that option when inserting the formula through the Range.Formula or Range.FormulaR1C1 property in VBA is unwieldy due to the necessity of having to double-up the double-quote characters within a quoted string.

The worksheet's native TEXT function can produce the same result without using quotes.

'formula to insert into C1 - =IF(A1<>"", B1, "")
range("C1").formula = "=IF(A1<>"""", B1, """")"         '<~quote chars doubled up
range("C1").formula = "=IF(A1<>TEXT(,), B1, TEXT(,))"   '<~with TEXT(,) instead

To my eye, using TEXT(,) in place of "" cleans up even a simple formula like the one above. The benefits become increasingly significant when used in more complicated formulas like the practise of appending an empty string to a VLOOKUP to avoid returning a zero to the cell when a lookup results in a blank or returning an empty string on no-match with IFERROR.

'formula to insert into D1 - =IFERROR(VLOOKUP(A1, B:C, 2, FALSE)&"", "")
range("D1").formula = "=IFERROR(VLOOKUP(A1, B:C, 2, FALSE)&"""", """")"
range("D1").formula = "=IFERROR(VLOOKUP(A1, B:C, 2, FALSE)&TEXT(,), TEXT(,))"

With TEXT(,) replacing the old "" method of delivering an empty string, you might get to stop using an abacus to determine whether you have the right number of quote characters in a formula string.

Read line with Scanner

Try to use r.hasNext() instead of r.hasNextLine():

while(r.hasNext()) {
        scan = r.next();

Notice: Array to string conversion in

Even simpler:

$get = @mysql_query("SELECT money FROM players WHERE username = '" . $_SESSION['username'] . "'");

note the quotes around username in the $_SESSION reference.

How to configure custom PYTHONPATH with VM and PyCharm?

To me the solution was to go to

Run > Edit Configuration > Defaults > Python

then manage the

  • "Add content roots to PYTHONPATH" and
  • "Add source root to PYTHONPATH"

checkboxes, as well as setting the "Working directory" field.

If you have set up your own Run/Debug Configurations then you might want to go to

Run > Edit Configuration > Python > [Whatever you called your config]

and edit it there.

My problem was that I wanted to have my whole repository included in my PyCharm 2016.2 project, but only a subfolder was the actual python source code root. I added it as "Source Root" by right clicking the folder then

Mark directory as > Source Root

Then unchecking "Add content roots to PYTHONPATH" and checking "Add source root to PYTHONPATH" in the Run/Debug config menu. I then checked the folder pathing by doing:

import sys
logger.info(sys.path)

This outputed:

[
    '/usr/local/my_project_root/my_sources_root', 
    '/usr/local/my_project_root/my_sources_root', 
    '/usr/lib/python3.4', '/usr/lib/python3.4/plat-x86_64-linux-gnu', 
    '/usr/lib/python3.4/lib-dynload', 
    '/usr/local/lib/python3.4/dist-packages', 
    '/usr/lib/python3/dist-packages'
]

However, without the fix it said:

[
    '/usr/local/my_project_root/my_sources_root', 
    '/usr/local/my_project_root',                   <-- NOT WANTED
    '/usr/lib/python3.4', 
    '/usr/lib/python3.4/plat-x86_64-linux-gnu', 
    '/usr/lib/python3.4/lib-dynload', 
    '/usr/local/lib/python3.4/dist-packages', 
    '/usr/lib/python3/dist-packages'
]

Which meant I got the project root folder included. This messed up the pathing for me.

Using sudo with Python script

To pass the password to sudo's stdin:

#!/usr/bin/env python
from subprocess import Popen, PIPE

sudo_password = 'mypass'
command = 'mount -t vboxsf myfolder /home/myuser/myfolder'.split()

p = Popen(['sudo', '-S'] + command, stdin=PIPE, stderr=PIPE,
          universal_newlines=True)
sudo_prompt = p.communicate(sudo_password + '\n')[1]

Note: you could probably configure passwordless sudo or SUDO_ASKPASS command instead of hardcoding your password in the source code.

c# open file with default application and parameters

If you want the file to be opened with the default application, I mean without specifying Acrobat or Reader, you can't open the file in the specified page.

On the other hand, if you are Ok with specifying Acrobat or Reader, keep reading:


You can do it without telling the full Acrobat path, like this:

Process myProcess = new Process();    
myProcess.StartInfo.FileName = "acroRd32.exe"; //not the full application path
myProcess.StartInfo.Arguments = "/A \"page=2=OpenActions\" C:\\example.pdf";
myProcess.Start();

If you don't want the pdf to open with Reader but with Acrobat, chage the second line like this:

myProcess.StartInfo.FileName = "Acrobat.exe";

You can query the registry to identify the default application to open pdf files and then define FileName on your process's StartInfo accordingly.

Follow this question for details on doing that: Finding the default application for opening a particular file type on Windows

How to include a class in PHP

Your code should be something like

require_once('class.twitter.php');

$t = new twitter;
$t->username = 'user';
$t->password = 'password';

$data = $t->publicTimeline();

Passing data between different controller action methods

Have you tried using ASP.NET MVC TempData ?

ASP.NET MVC TempData dictionary is used to share data between controller actions. The value of TempData persists until it is read or until the current user’s session times out. Persisting data in TempData is useful in scenarios such as redirection, when values are needed beyond a single request.

The code would be something like this:

[HttpPost]
public ActionResult ApplicationPoolsUpdate(ServiceViewModel viewModel)
{
    XDocument updatedResultsDocument = myService.UpdateApplicationPools();
    TempData["doc"] = updatedResultsDocument;
    return RedirectToAction("UpdateConfirmation");
}

And in the ApplicationPoolController:

public ActionResult UpdateConfirmation()
{
    if (TempData["doc"] != null)
    {
        XDocument updatedResultsDocument = (XDocument) TempData["doc"];
            ...
        return View();
    }
}

How to remove specific element from an array using python

Using filter() and lambda would provide a neat and terse method of removing unwanted values:

newEmails = list(filter(lambda x : x != '[email protected]', emails))

This does not modify emails. It creates the new list newEmails containing only elements for which the anonymous function returned True.

How to convert a multipart file to File?

MultipartFile.transferTo(File) is nice, but don't forget to clean the temp file after all.

// ask JVM to ask operating system to create temp file
File tempFile = File.createTempFile(TEMP_FILE_PREFIX, TEMP_FILE_POSTFIX);

// ask JVM to delete it upon JVM exit if you forgot / can't delete due exception
tempFile.deleteOnExit();

// transfer MultipartFile to File
multipartFile.transferTo(tempFile);

// do business logic here
result = businessLogic(tempFile);

// tidy up
tempFile.delete();

Check out Razzlero's comment about File.deleteOnExit() executed upon JVM exit (which may be extremely rare) details below.

Determine the data types of a data frame's columns

Another option is using the map function of the purrr package.

library(purrr)
map(df,class)

How do I disable fail_on_empty_beans in Jackson?

In my case I didnt need to disable it , rather I had to put this code on top of my class : (and this solved my issue)

    @JsonNaming(PropertyNamingStrategy.SnakeCaseStrategy.class)//this is what was added
    @Value //this was there already
    @Builder//this was there already

public class NameOfClass {
     //some code in here.
}

How do I set the background color of my main screen in Flutter?

On the basic example of Flutter you can set with backgroundColor: Colors.X of Scaffold

  @override
 Widget build(BuildContext context) {
   // This method is rerun every time setState is called, for instance as done
  // by the _incrementCounter method above.
   //
  // The Flutter framework has been optimized to make rerunning build methods
   // fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
  backgroundColor: Colors.blue,
  body: Center(
    // Center is a layout widget. It takes a single child and positions it
    // in the middle of the parent.
    child: Column(
      // Column is also layout widget. It takes a list of children and
      // arranges them vertically. By default, it sizes itself to fit its
      // children horizontally, and tries to be as tall as its parent.
      //
      // Invoke "debug painting" (press "p" in the console, choose the
      // "Toggle Debug Paint" action from the Flutter Inspector in Android
      // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
      // to see the wireframe for each widget.
      //
      // Column has various properties to control how it sizes itself and
      // how it positions its children. Here we use mainAxisAlignment to
      // center the children vertically; the main axis here is the vertical
      // axis because Columns are vertical (the cross axis would be
      // horizontal).
      mainAxisAlignment: MainAxisAlignment.center,
      children: <Widget>[
        Text(
          'You have pushed the button this many times:',
        ),
        Text(
          '$_counter',
          style: Theme.of(context).textTheme.display1,
        ),
      ],
    ),
  ),
  floatingActionButton: FloatingActionButton(
    onPressed: _incrementCounter,
    tooltip: 'Increment',
    child: Icon(Icons.add_circle),
  ), // This trailing comma makes auto-formatting nicer for build methods.
);
}

Difference between File.separator and slash in paths

You use File.separator because someday your program might run on a platform developed in a far-off land, a land of strange things and stranger people, where horses cry and cows operate all the elevators. In this land, people have traditionally used the ":" character as a file separator, and so dutifully the JVM obeys their wishes.

Disable Logback in SpringBoot

I do like this to solve my problem

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-log4j</artifactId>
    <exclusions>
        <exclusion>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
        </exclusion>
    </exclusions>
</dependency>

Save and load weights in keras

For loading weights, you need to have a model first. It must be:

existingModel.save_weights('weightsfile.h5')
existingModel.load_weights('weightsfile.h5')     

If you want to save and load the entire model (this includes the model's configuration, it's weights and the optimizer states for further training):

model.save_model('filename')
model = load_model('filename')

Questions every good PHP Developer should be able to answer

Why you should never output user input directly!

Printing things like data from GET directly can lead to Cross-site scripting (XSS) vulnerabilities. Thats why you should always send input from the client through htmlspecialchars() first.

JPA CascadeType.ALL does not delete orphans

If you are using JPA 2.0, you can now use the orphanRemoval=true attribute of the @xxxToMany annotation to remove orphans.

Actually, CascadeType.DELETE_ORPHAN has been deprecated in 3.5.2-Final.

Read values into a shell variable from a pipe

Piping something into an expression involving an assignment doesn't behave like that.

Instead, try:

test=$(echo "hello world"); echo test=$test

How to delete projects in Intellij IDEA 14?

Deleting and Recreating a project with same name is tricky. If you try to follow above suggested steps and try to create a project with same name as the one you just deleted, you will run into error like

'C:/xxxxxx/pom.xml' already exists in VFS

Here is what I found would work.

  1. Remove module
  2. File -> Invalidate Cache (at this point the Intelli IDEA wants to restart)
  3. Close project
  4. Delete the folder form system explorer.
  5. Now you can create a project with same name as before.

How to disable the ability to select in a DataGridView?

Enabled property to false

or

this.dataGridView1.DefaultCellStyle.SelectionBackColor = this.dataGridView1.DefaultCellStyle.BackColor;
this.dataGridView1.DefaultCellStyle.SelectionForeColor = this.dataGridView1.DefaultCellStyle.ForeColor;

Calling Non-Static Method In Static Method In Java

The only way to call a non-static method from a static method is to have an instance of the class containing the non-static method. By definition, a non-static method is one that is called ON an instance of some class, whereas a static method belongs to the class itself.

iPhone App Development on Ubuntu

Perhaps the best way would be to implement your app as a web app. I think you can also make web apps that run direct on the phone, without internet access or a remote server.

Web app, sounds lame? But a lot can be done with DHTML / HTML5 / JavaScript. It's a rare app that requires more power and couldn't be done as a web app. And you get pretty good cross platform with Web / JavaScript - the browsers vary a bit but a good web dev can write one web app that works pretty much everywhere.

Of course if you're writing a high-performance 3D game, the browser might not deliver what you need! maybe in a few years... Apparently some Google hackers ported Quake 2 to HTML5 already!

http://web.appstorm.net/roundups/browsers/10-html5-games-paving-the-way/

find difference between two text files with one item per line

I successfully used

diff "${file1}" "${file2}" | grep "<" | sed 's/^<//g' > "${diff_file}"

Outputting the difference to a file.

CSS values using HTML5 data attribute

As of today, you can read some values from HTML5 data attributes in CSS3 declarations. In CaioToOn's fiddle the CSS code can use the data properties for setting the content.

Unfortunately it is not working for the width and height (tested in Google Chrome 35, Mozilla Firefox 30 & Internet Explorer 11).

But there is a CSS3 attr() Polyfill from Fabrice Weinberg which provides support for data-width and data-height. You can find the GitHub repo to it here: cssattr.js.

Normalizing a list of numbers in Python

There isn't any function in the standard library (to my knowledge) that will do it, but there are absolutely modules out there which have such functions. However, its easy enough that you can just write your own function:

def normalize(lst):
    s = sum(lst)
    return map(lambda x: float(x)/s, lst)

Sample output:

>>> normed = normalize(raw)
>>> normed
[0.25, 0.5, 0.25]

How to swap String characters in Java?

import java.io.*;
class swaping
{
     public static void main(String args[]) 
     {
         String name="premkumarg";
         int len=name.length();
         char[] c = name.toCharArray();
         for(int i=0;i<len-1;i=i+2)
         {
             char temp= c[i];
             c[i]=c[i+1];
             c[i+1]=temp;
         }

         System.out.println("Swapping string is: ");
         System.out.println(c);

    }
}

Use PHP composer to clone git repo

If you want to use a composer.json from GitHub you would look at this example (under the VCS section).

The package section is for packages that do not have the composer.json. However, you didn't follow that example as well or it would also have worked. Do read what it says about package repositories:

Basically, you define the same information that is included in the composer repository's packages.json, but only for a single package. Again, the minimum required fields are name, version, and either of dist or source.

How to tell if a string is not defined in a Bash shell script

call set without any arguments.. it outputs all the vars defined..
the last ones on the list would be the ones defined in your script..
so you could pipe its output to something that could figure out what things are defined and whats not

Databinding an enum property to a ComboBox in WPF

If you are using a MVVM, based on @rudigrobler answer you can do the following:

Add the following property to the ViewModel class

public Array ExampleEnumValues => Enum.GetValues(typeof(ExampleEnum));

Then in the XAML do the following:

<ComboBox ItemsSource="{Binding ExampleEnumValues}" ... />

yii2 hidden input value

You can use this code line in view(form)

 <?= $form->field($model, 'hidden1')->hiddenInput(['value'=>'your_value'])->label(false) ?>

Please refere this as example

If your need to pass currant date and time as hidden input : Model attribute is 'created_on' and its value is retrieve from date('Y-m-d H:i:s') , just like:"2020-03-10 09:00:00"

  <?= $form->field($model, 'created_on')->hiddenInput(['value'=>date('Y-m-d H:i:s')])->label(false) ?>

Upload a file to Amazon S3 with NodeJS

Thanks to David as his solution helped me come up with my solution for uploading multi-part files from my Heroku hosted site to S3 bucket. I did it using formidable to handle incoming form and fs to get the file content. Hopefully, it may help you.

api.service.ts

public upload(files): Observable<any> {  
    const formData: FormData = new FormData(); 
    files.forEach(file => {
      // create a new multipart-form for every file 
      formData.append('file', file, file.name);           
    });   
    return this.http.post(uploadUrl, formData).pipe(
      map(this.extractData),
      catchError(this.handleError)); 
  }
}

server.js

app.post('/api/upload', upload);
app.use('/api/upload', router);

upload.js

const IncomingForm = require('formidable').IncomingForm;
const fs = require('fs');
const AWS = require('aws-sdk');

module.exports = function upload(req, res) {
    var form = new IncomingForm();

    const bucket = new AWS.S3(
      {
        signatureVersion: 'v4',
        accessKeyId: process.env.AWS_ACCESS_KEY_ID,
        secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
        region: 'us-east-1'       
      }
    ); 

    form.on('file', (field, file) => {

        const fileContent = fs.readFileSync(file.path);

        const s3Params = {
            Bucket: process.env.AWS_S3_BUCKET,
            Key: 'folder/' + file.name,
            Expires: 60,             
            Body: fileContent,
            ACL: 'public-read'
        };

        bucket.upload(s3Params, function(err, data) {
            if (err) {
                throw err;
            }            
            console.log('File uploaded to: ' + data.Location);
            fs.unlink(file.path, function (err) {
              if (err) {
                  console.error(err);
              }
              console.log('Temp File Delete');
          });
        });
    });              

    // The second callback is called when the form is completely parsed. 
    // In this case, we want to send back a success status code.
    form.on('end', () => {        
      res.status(200).json('upload ok');
    });

    form.parse(req);
}

upload-image.component.ts

import { Component, OnInit, ViewChild, Output, EventEmitter, Input } from '@angular/core';
import { ApiService } from '../api.service';
import { MatSnackBar } from '@angular/material/snack-bar';

@Component({
  selector: 'app-upload-image',
  templateUrl: './upload-image.component.html',
  styleUrls: ['./upload-image.component.css']
})

export class UploadImageComponent implements OnInit {
  public files: Set<File> = new Set();
  @ViewChild('file', { static: false }) file;
  public uploadedFiles: Array<string> = new Array<string>();
  public uploadedFileNames: Array<string> = new Array<string>();
  @Output() filesOutput = new EventEmitter<Array<string>>();
  @Input() CurrentImage: string;
  @Input() IsPublic: boolean;
  @Output() valueUpdate = new EventEmitter();
  strUploadedFiles:string = '';
  filesUploaded: boolean = false;     

  constructor(private api: ApiService, public snackBar: MatSnackBar,) { }

  ngOnInit() {    
  }

  updateValue(val) {  
    this.valueUpdate.emit(val);  
  }  

  reset()
  {
    this.files = new Set();
    this.uploadedFiles = new Array<string>();
    this.uploadedFileNames = new Array<string>();
    this.filesUploaded = false;
  }

  upload() { 

    this.api.upload(this.files).subscribe(res => {   
      this.filesOutput.emit(this.uploadedFiles); 
      if (res == 'upload ok')
      {
        this.reset(); 
      }     
    }, err => {
      console.log(err);
    });
  }

  onFilesAdded() {
    var txt = '';
    const files: { [key: string]: File } = this.file.nativeElement.files;

    for (let key in files) {
      if (!isNaN(parseInt(key))) {

        var currentFile = files[key];
        var sFileExtension = currentFile.name.split('.')[currentFile.name.split('.').length - 1].toLowerCase();
        var iFileSize = currentFile.size;

        if (!(sFileExtension === "jpg" 
              || sFileExtension === "png") 
              || iFileSize > 671329) {
            txt = "File type : " + sFileExtension + "\n\n";
            txt += "Size: " + iFileSize + "\n\n";
            txt += "Please make sure your file is in jpg or png format and less than 655 KB.\n\n";
            alert(txt);
            return false;
        }

        this.files.add(files[key]);
        this.uploadedFiles.push('https://gourmet-philatelist-assets.s3.amazonaws.com/folder/' + files[key].name);
        this.uploadedFileNames.push(files[key].name);
        if (this.IsPublic && this.uploadedFileNames.length == 1)
        {
          this.filesUploaded = true;
          this.updateValue(files[key].name);
          break;
        } 
        else if (!this.IsPublic && this.uploadedFileNames.length == 3)
        {
          this.strUploadedFiles += files[key].name;          
          this.updateValue(this.strUploadedFiles); 
          this.filesUploaded = true;
          break;
        }
        else
        {
          this.strUploadedFiles += files[key].name + ",";          
          this.updateValue(this.strUploadedFiles); 
        }      
      }
    }    
  }

  addFiles() {
    this.file.nativeElement.click();  
  }

  openSnackBar(message: string, action: string) {
    this.snackBar.open(message, action, {
      duration: 2000,
      verticalPosition: 'top'
    });
  }   

}

upload-image.component.html

<input type="file" #file style="display: none" (change)="onFilesAdded()" multiple />
&nbsp;<button mat-raised-button color="primary" 
         [disabled]="filesUploaded" (click)="$event.preventDefault(); addFiles()">
  Add Files
</button>
&nbsp;<button class="btn btn-success" [disabled]="uploadedFileNames.length == 0" (click)="$event.preventDefault(); upload()">
  Upload
</button>

How to sort a HashSet?

You can use Java 8 collectors and TreeSet

list.stream().collect(Collectors.toCollection(TreeSet::new))

javascript variable reference/alias

Expanding on user187291's post, you could also use getters/setters to get around having to use functions.

var x = 1;
var ref = {
    get x()  { return x; },
    set x(v) { x = v; }
};
(ref.x)++;
console.log(x); // prints '2'
x--;
console.log(ref.x); // prints '1'

Android Percentage Layout Height

android:layout_weight=".YOURVALUE" is best way to implement in percentage

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/logTextBox"
        android:layout_width="fill_parent"
        android:layout_height="0dp"
        android:layout_weight=".20"
        android:maxLines="500"
        android:scrollbars="vertical"
        android:singleLine="false"
        android:text="@string/logText" >
    </TextView>

</LinearLayout>

Want to move a particular div to right

For me, I used margin-left: auto; which is more responsive with horizontal resizing.

How to output MySQL query results in CSV format?

Using the solution posted by Tim, I created this bash script to facilitate the process (root password is requested, but you can modify the script easily to ask for any other user):

#!/bin/bash

if [ "$1" == "" ];then
    echo "Usage: $0 DATABASE TABLE [MYSQL EXTRA COMMANDS]"
    exit
fi

DBNAME=$1
TABLE=$2
FNAME=$1.$2.csv
MCOMM=$3

echo "MySQL password:"
stty -echo
read PASS
stty echo

mysql -uroot -p$PASS $MCOMM $DBNAME -B -e "SELECT * FROM $TABLE;" | sed "s/'/\'/;s/\t/\",\"/g;s/^/\"/;s/$/\"/;s/\n//g" > $FNAME

It will create a file named: database.table.csv

How to set a dropdownlist item as selected in ASP.NET?

dropdownlist.ClearSelection(); //making sure the previous selection has been cleared
dropdownlist.Items.FindByValue(value).Selected = true;

Using the GET parameter of a URL in JavaScript

You can get the "search" part of the location object - and then parse it out.

var matches = /param1=([^&#=]*)/.exec(window.location.search);
var param1 = matches[1];

Iterate through a C array

If the size of the array is known at compile time, you can use the structure size to determine the number of elements.

struct foo fooarr[10];

for(i = 0; i < sizeof(fooarr) / sizeof(struct foo); i++)
{
  do_something(fooarr[i].data);
}

If it is not known at compile time, you will need to store a size somewhere or create a special terminator value at the end of the array.

ggplot2 legend to bottom and horizontal

If you want to move the position of the legend please use the following code:

library(reshape2) # for melt
df <- melt(outer(1:4, 1:4), varnames = c("X1", "X2"))
p1 <- ggplot(df, aes(X1, X2)) + geom_tile(aes(fill = value))
p1 + scale_fill_continuous(guide = guide_legend()) +
    theme(legend.position="bottom")

This should give you the desired result. Legend at bottom

How to check if an element is in an array

Just in case anybody is trying to find if an indexPath is among the selected ones (like in a UICollectionView or UITableView cellForItemAtIndexPath functions):

    var isSelectedItem = false
    if let selectedIndexPaths = collectionView.indexPathsForSelectedItems() as? [NSIndexPath]{
        if contains(selectedIndexPaths, indexPath) {
            isSelectedItem = true
        }
    }

Set Colorbar Range in matplotlib

Not sure if this is the most elegant solution (this is what I used), but you could scale your data to the range between 0 to 1 and then modify the colorbar:

import matplotlib as mpl
...
ax, _ = mpl.colorbar.make_axes(plt.gca(), shrink=0.5)
cbar = mpl.colorbar.ColorbarBase(ax, cmap=cm,
                       norm=mpl.colors.Normalize(vmin=-0.5, vmax=1.5))
cbar.set_clim(-2.0, 2.0)

With the two different limits you can control the range and legend of the colorbar. In this example only the range between -0.5 to 1.5 is show in the bar, while the colormap covers -2 to 2 (so this could be your data range, which you record before the scaling).

So instead of scaling the colormap you scale your data and fit the colorbar to that.

How to execute a JavaScript function when I have its name as a string

BE CAREFUL!!!

One should try to avoid calling a function by string in JavaScript for two reasons:

Reason 1: Some code obfuscators will wreck your code as they will change the function names, making the string invalid.

Reason 2: It is much harder to maintain code that uses this methodology as it is much harder to locate usages of the methods called by a string.

Fixed footer in Bootstrap

Add this:

<div class="footer fixed-bottom">

How to iterate through table in Lua?

For those wondering why ipairs doesn't print all the values of the table all the time, here's why (I would comment this, but I don't have enough good boy points).

The function ipairs only works on tables which have an element with the key 1. If there is an element with the key 1, ipairs will try to go as far as it can in a sequential order, 1 -> 2 -> 3 -> 4 etc until it cant find an element with a key that is the next in the sequence. The order of the elements does not matter.

Tables that do not meet those requirements will not work with ipairs, use pairs instead.

Examples:

ipairsCompatable = {"AAA", "BBB", "CCC"}
ipairsCompatable2 = {[1] = "DDD", [2] = "EEE", [3] = "FFF"}
ipairsCompatable3 = {[3] = "work", [2] = "does", [1] = "this"}

notIpairsCompatable = {[2] = "this", [3] = "does", [4] = "not"}
notIpairsCompatable2 = {[2] = "this", [5] = "doesn't", [24] = "either"}

ipairs will go as far as it can with it's iterations but won't iterate over any other element in the table.

kindofIpairsCompatable = {[2] = 2, ["cool"] = "bro", [1] = 1, [3] = 3, [5] = 5 }

When printing these tables, these are the outputs. I've also included pairs outputs for comparison.

ipairs + ipairsCompatable
1       AAA
2       BBB
3       CCC

ipairs + ipairsCompatable2
1       DDD
2       EEE
3       FFF

ipairs + ipairsCompatable3
1       this
2       does
3       work

ipairs + notIpairsCompatable

pairs + notIpairsCompatable
2       this
3       does
4       not

ipairs + notIpairsCompatable2

pairs + notIpairsCompatable2
2       this
5       doesnt
24      either

ipairs + kindofIpairsCompatable
1       1
2       2
3       3

pairs + kindofIpairsCompatable
1       1
2       2
3       3
5       5
cool    bro

Dynamic height for DIV

You should be okay to just take the height property out of the CSS.

How can I use String substring in Swift 4? 'substring(to:)' is deprecated: Please use String slicing subscript with a 'partial range from' operator

The conversion of your code to Swift 4 can also be done this way:

let str = "Hello, playground"
let index = str.index(of: ",")!
let substr = str.prefix(upTo: index)

You can use the code below to have a new string:

let newString = String(str.prefix(upTo: index))

Calling a javascript function recursively

Using Named Function Expressions:

You can give a function expression a name that is actually private and is only visible from inside of the function ifself:

var factorial = function myself (n) {
    if (n <= 1) {
        return 1;
    }
    return n * myself(n-1);
}
typeof myself === 'undefined'

Here myself is visible only inside of the function itself.

You can use this private name to call the function recursively.

See 13. Function Definition of the ECMAScript 5 spec:

The Identifier in a FunctionExpression can be referenced from inside the FunctionExpression's FunctionBody to allow the function to call itself recursively. However, unlike in a FunctionDeclaration, the Identifier in a FunctionExpression cannot be referenced from and does not affect the scope enclosing the FunctionExpression.

Please note that Internet Explorer up to version 8 doesn't behave correctly as the name is actually visible in the enclosing variable environment, and it references a duplicate of the actual function (see patrick dw's comment below).

Using arguments.callee:

Alternatively you could use arguments.callee to refer to the current function:

var factorial = function (n) {
    if (n <= 1) {
        return 1;
    }
    return n * arguments.callee(n-1);
}

The 5th edition of ECMAScript forbids use of arguments.callee() in strict mode, however:

(From MDN): In normal code arguments.callee refers to the enclosing function. This use case is weak: simply name the enclosing function! Moreover, arguments.callee substantially hinders optimizations like inlining functions, because it must be made possible to provide a reference to the un-inlined function if arguments.callee is accessed. arguments.callee for strict mode functions is a non-deletable property which throws when set or retrieved.

How to fluently build JSON in Java?

The reference implementation includes a fluent interface. Check out JSONWriter and its toString-implementing subclass JSONStringer

Read/write files within a Linux kernel module

Since version 4.14 of Linux kernel, vfs_read and vfs_write functions are no longer exported for use in modules. Instead, functions exclusively for kernel's file access are provided:

# Read the file from the kernel space.
ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos);

# Write the file from the kernel space.
ssize_t kernel_write(struct file *file, const void *buf, size_t count,
            loff_t *pos);

Also, filp_open no longer accepts user-space string, so it can be used for kernel access directly (without dance with set_fs).

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver in Eclipse

For Gradle-based projects you need a dependency on MySQL Java Connector:

dependencies {
    compile 'mysql:mysql-connector-java:6.0.+'
}

Cannot overwrite model once compiled Mongoose

ther are so many good answer but for checking we can do easier job. i mean in most popular answer there is check.js ,our guy made it so much complicated ,i suggest:

function connectToDB() {
  if (mongoose.connection.readyState === 1) {
    console.log("already connected");
    return;
  }
  mongoose.connect(
    process.env.MONGODB_URL,
    {
      useCreateIndex: true,
      useFindAndModify: false,
      useNewUrlParser: true,
      useUnifiedTopology: true,
    },
    (err) => {
      if (err) throw err;
      console.log("DB connected");
    },
  );
}

readyState== 1 means connected
so does not try to connect again
so you won't get the error
i think it because of connecting while it is connected
it is another way of connecting to db