Programs & Examples On #Session replication

sorting and paging with gridview asp.net

<asp:GridView 
    ID="GridView1" runat="server" AutoGenerateColumns="false" AllowSorting="True" onsorting="GridView1_Sorting" EnableViewState="true"> 
    <Columns>
        <asp:BoundField DataField="bookid" HeaderText="BOOK ID"SortExpression="bookid"  />
        <asp:BoundField DataField="bookname" HeaderText="BOOK NAME" />
        <asp:BoundField DataField="writer" HeaderText="WRITER" />
        <asp:BoundField DataField="totalbook" HeaderText="TOTALBOOK" SortExpression="totalbook"  />
        <asp:BoundField DataField="availablebook" HeaderText="AVAILABLE BOOK" />
    </Columns>
</asp:GridView>

Code behind:

protected void Page_Load(object sender, EventArgs e) {
        if (!IsPostBack) {
            string query = "SELECT * FROM book";
            DataTable DT = new DataTable();
            SqlDataAdapter DA = new SqlDataAdapter(query, sqlCon);
            DA.Fill(DT);

            GridView1.DataSource = DT;
            GridView1.DataBind();
        }
    }

    protected void GridView1_Sorting(object sender, GridViewSortEventArgs e) {

        string query = "SELECT * FROM book";
        DataTable DT = new DataTable();
        SqlDataAdapter DA = new SqlDataAdapter(query, sqlCon);
        DA.Fill(DT);

        GridView1.DataSource = DT;
        GridView1.DataBind();

        if (DT != null) {
            DataView dataView = new DataView(DT);
            dataView.Sort = e.SortExpression + " " + ConvertSortDirectionToSql(e.SortDirection);

            GridView1.DataSource = dataView;
            GridView1.DataBind();
        }
    }

    private string GridViewSortDirection {
        get { return ViewState["SortDirection"] as string ?? "DESC"; }
        set { ViewState["SortDirection"] = value; }
    }

    private string ConvertSortDirectionToSql(SortDirection sortDirection) {
        switch (GridViewSortDirection) {
            case "ASC":
                GridViewSortDirection = "DESC";
                break;

            case "DESC":
                GridViewSortDirection = "ASC";
                break;
        }

        return GridViewSortDirection;
    }
}

How to fix "Incorrect string value" errors?

First check if your default_character_set_name is utf8.

SELECT default_character_set_name FROM information_schema.SCHEMATA S WHERE schema_name = "DBNAME";

If the result is not utf8 you must convert your database. At first you must save a dump.

To change the character set encoding to UTF-8 for all of the tables in the specified database, type the following command at the command line. Replace DBNAME with the database name:

mysql --database=DBNAME -B -N -e "SHOW TABLES" | awk '{print "SET foreign_key_checks = 0; ALTER TABLE", $1, "CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci; SET foreign_key_checks = 1; "}' | mysql --database=DBNAME

To change the character set encoding to UTF-8 for the database itself, type the following command at the mysql> prompt. Replace DBNAME with the database name:

ALTER DATABASE DBNAME CHARACTER SET utf8 COLLATE utf8_general_ci;

You can now retry to to write utf8 character into your database. This solution help me when i try to upload 200000 row of csv file into my database.

How to re import an updated package while in Python Interpreter?

See here for a good explanation of how your dependent modules won't be reloaded and the effects that can have:

http://pyunit.sourceforge.net/notes/reloading.html

The way pyunit solved it was to track dependent modules by overriding __import__ then to delete each of them from sys.modules and re-import. They probably could've just reload'ed them, though.

java.lang.UnsupportedClassVersionError: Bad version number in .class file?

Another scenario where this could happen is when you are launching an instance of eclipse (for debug etc.) from a host eclipse - in which case, altering the project's level or JRE library on the project's classpath alone doesn't help. What matters is the JRE used to launch the target eclipse environment.

Android: I am unable to have ViewPager WRAP_CONTENT

This ViewPager only resizes to the current visible children (not the biggest of its actual children)

The idea from https://stackoverflow.com/a/56325869/4718406

public class DynamicHeightViewPager extends ViewPager {

public DynamicHeightViewPager (Context context) {
    super(context);
    initPageChangeListener();
}

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



private void initPageChangeListener() {
    addOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
        @Override
        public void onPageSelected(int position) {
            requestLayout();
        }
    });
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    //View child = getChildAt(getCurrentItem());
    View child = getCurrentView(this);
    if (child != null) {
        child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, 
         MeasureSpec.UNSPECIFIED));
        int h = child.getMeasuredHeight();

        heightMeasureSpec = MeasureSpec.makeMeasureSpec(h, MeasureSpec.EXACTLY);
    }
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}


View getCurrentView(ViewPager viewPager) {
    try {
        final int currentItem = viewPager.getCurrentItem();
        for (int i = 0; i < viewPager.getChildCount(); i++) {
            final View child = viewPager.getChildAt(i);
            final ViewPager.LayoutParams layoutParams = (ViewPager.LayoutParams) 
             child.getLayoutParams();

            Field f = layoutParams.getClass().getDeclaredField("position"); 
            //NoSuchFieldException
            f.setAccessible(true);
            int position = (Integer) f.get(layoutParams); //IllegalAccessException

            if (!layoutParams.isDecor && currentItem == position) {
                return child;
            }
        }
    } catch (NoSuchFieldException e) {
        e.fillInStackTrace();
    } catch (IllegalArgumentException e) {
        e.fillInStackTrace();
    } catch (IllegalAccessException e) {
        e.fillInStackTrace();
    }
    return null;
}

}

Java: How to get input from System.console()

Using Console to read input (usable only outside of an IDE):

System.out.print("Enter something:");
String input = System.console().readLine();

Another way (works everywhere):

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Test {
    public static void main(String[] args) throws IOException { 
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        System.out.print("Enter String");
        String s = br.readLine();
        System.out.print("Enter Integer:");
        try {
            int i = Integer.parseInt(br.readLine());
        } catch(NumberFormatException nfe) {
            System.err.println("Invalid Format!");
        }
    }
}

System.console() returns null in an IDE.
So if you really need to use System.console(), read this solution from McDowell.

Is the server running on host "localhost" (::1) and accepting TCP/IP connections on port 5432?

It also gives the same error if you just stop your PostgreSQL app. You just need to start it again. (PostgreSQL 11)

Get random boolean in Java

The easiest way to initialize a random number generator is to use the parameterless constructor, for example

Random generator = new Random();

However, in using this constructor you should recognize that algorithmic random number generators are not truly random, they are really algorithms that generate a fixed but random-looking sequence of numbers.

You can make it appear more 'random' by giving the Random constructor the 'seed' parameter, which you can dynamically built by for example using system time in milliseconds (which will always be different)

What is a callback?

Definition

A callback is executable code that is passed as an argument to other code.

Implementation

// Parent can Read
public class Parent
{
    public string Read(){ /*reads here*/ };
}

// Child need Info
public class Child
{
    private string information;
    // declare a Delegate
    delegate string GetInfo();
    // use an instance of the declared Delegate
    public GetInfo GetMeInformation;

    public void ObtainInfo()
    {
        // Child will use the Parent capabilities via the Delegate
        information = GetMeInformation();
    }
}

Usage

Parent Peter = new Parent();
Child Johny = new Child();

// Tell Johny from where to obtain info
Johny.GetMeInformation = Peter.Read;

Johny.ObtainInfo(); // here Johny 'asks' Peter to read

Links

CSS:Defining Styles for input elements inside a div

Like this.

.divContainer input[type="text"] {
  width:150px;
}
.divContainer input[type="radio"] {
  width:20px;
}

Conflict with dependency 'com.android.support:support-annotations' in project ':app'. Resolved versions for app (26.1.0) and test app (27.1.1) differ.

Based on your screenshot i found two working solutions:

First solution: add to dependencies of your gradle module this line

compile 'com.android.support:support-annotations:27.1.1'

and sync your project

Note: if you are using Android studio 3+ change compile to implementation

Second solution: Configure project-wide properties found in the documentation https://developer.android.com/studio/build/gradle-tips.html#configure-project-wide-properties

in project gradle add this line:

// This block encapsulates custom properties and makes them available to all
// modules in the project.
ext {
    // The following are only a few examples of the types of properties you can define.
    compileSdkVersion = 26
    // You can also use this to specify versions for dependencies. Having consistent
    // versions between modules can avoid behavior conflicts.
    supportLibVersion = "27.1.1"
}

Then to access this section change compileSdkVersionline to be

compileSdkVersion rootProject.ext.compileSdkVersion

and at dependencies section change the imported library to be like this:

compile "com.android.support:appcompat-v7:${rootProject.ext.supportLibVersion}"

and sync your project

Note: if you are using Android studio 3+ change compile to implementation

For the difference between compile and implementation look at this What's the difference between implementation and compile in gradle

How can I restart a Java application?

System.err.println("Someone is Restarting me...");
setVisible(false);
try {
    Thread.sleep(600);
} catch (InterruptedException e1) {
    e1.printStackTrace();
}
setVisible(true);

I guess you don't really want to stop the application, but to "Restart" it. For that, you could use this and add your "Reset" before the sleep and after the invisible window.

PHP Warning: PHP Startup: Unable to load dynamic library

phpStom with XAMPP

TL;DR Except from verifying that the files exist, you might need to add the drive letter to some records in your php.ini file

I suddenly started having a problem using phpStorm 7 for debugging php with xampp and xdebug. When trying to set intellij interperter to be xampps php I got a lot of the warnings like the one in the question, for example:

Unable to load dynamic library '/xampp/php/ext/php_bz2.dll'

For some reason I had to add my drive letter to the records of extension_dir and browscap in the php.ini file:

extension_dir = "\xampp\php\ext"
browscap = "\xampp\php\extras\browscap.ini"

to

extension_dir = "e:\xampp\php\ext"
browscap = "e:\xampp\php\extras\browscap.ini"

Python idiom to return first item or None

isn't the idiomatic python equivalent to C-style ternary operators

cond and true_expr or false_expr

ie.

list = get_list()
return list and list[0] or None

Get List of connected USB Devices

To see the devices I was interested in, I had replace Win32_USBHub by Win32_PnPEntity in Adel Hazzah's code, based on this post. This works for me:

namespace ConsoleApplication1
{
  using System;
  using System.Collections.Generic;
  using System.Management; // need to add System.Management to your project references.

  class Program
  {
    static void Main(string[] args)
    {
      var usbDevices = GetUSBDevices();

      foreach (var usbDevice in usbDevices)
      {
        Console.WriteLine("Device ID: {0}, PNP Device ID: {1}, Description: {2}",
            usbDevice.DeviceID, usbDevice.PnpDeviceID, usbDevice.Description);
      }

      Console.Read();
    }

    static List<USBDeviceInfo> GetUSBDevices()
    {
      List<USBDeviceInfo> devices = new List<USBDeviceInfo>();

      ManagementObjectCollection collection;
      using (var searcher = new ManagementObjectSearcher(@"Select * From Win32_PnPEntity"))
        collection = searcher.Get();      

      foreach (var device in collection)
      {
        devices.Add(new USBDeviceInfo(
        (string)device.GetPropertyValue("DeviceID"),
        (string)device.GetPropertyValue("PNPDeviceID"),
        (string)device.GetPropertyValue("Description")
        ));
      }

      collection.Dispose();
      return devices;
    }
  }

  class USBDeviceInfo
  {
    public USBDeviceInfo(string deviceID, string pnpDeviceID, string description)
    {
      this.DeviceID = deviceID;
      this.PnpDeviceID = pnpDeviceID;
      this.Description = description;
    }
    public string DeviceID { get; private set; }
    public string PnpDeviceID { get; private set; }
    public string Description { get; private set; }
  }
}

The view didn't return an HttpResponse object. It returned None instead

Because the view must return render, not just call it. Change the last line to

return render(request, 'auth_lifecycle/user_profile.html',
           context_instance=RequestContext(request))

Using lodash to compare jagged arrays (items existence without order)

You can use lodashs xor for this

doArraysContainSameElements = _.xor(arr1, arr2).length === 0

If you consider array [1, 1] to be different than array [1] then you may improve performance a bit like so:

doArraysContainSameElements = arr1.length === arr2.length === 0 && _.xor(arr1, arr2).length === 0

Node.js Web Application examples/tutorials

Update

Dav Glass from Yahoo has given a talk at YuiConf2010 in November which is now available in Video from.

He shows to great extend how one can use YUI3 to render out widgets on the server side an make them work with GET requests when JS is disabled, or just make them work normally when it's active.

He also shows examples of how to use server side DOM to apply style sheets before rendering and other cool stuff.

The demos can be found on his GitHub Account.

The part that's missing IMO to make this really awesome, is some kind of underlying storage of the widget state. So that one can visit the page without JavaScript and everything works as expected, then they turn JS on and now the widget have the same state as before but work without page reloading, then throw in some saving to the server + WebSockets to sync between multiple open browser.... and the next generation of unobtrusive and gracefully degrading ARIA's is born.

Original Answer

Well go ahead and built it yourself then.

Seriously, 90% of all WebApps out there work fine with a REST approach, of course you could do magical things like superior user tracking, tracking of downloads in real time, checking which parts of videos are being watched etc.

One problem is scalability, as soon as you have more then 1 Node process, many (but not all) of the benefits of having the data stored between requests go away, so you have to make sure that clients always hit the same process. And even then, bigger things will yet again need a database layer.

Node.js isn't the solution to everything, I'm sure people will build really great stuff in the future, but that needs some time, right now many are just porting stuff over to Node to get things going.

What (IMHO) makes Node.js so great, is the fact that it streamlines the Development process, you have to write less code, it works perfectly with JSON, you loose all that context switching.

I mainly did gaming experiments so far, but I can for sure say that there will be many cool multi player (or even MMO) things in the future, that use both HTML5 and Node.js.

Node.js is still gaining traction, it's not even near to the RoR Hype some years ago (just take a look at the Node.js tag here on SO, hardly 4-5 questions a day).

Rome (or RoR) wasn't built over night, and neither will Node.js be.

Node.js has all the potential it needs, but people are still trying things out, so I'd suggest you to join them :)

prevent refresh of page when button inside form clicked

<form method="POST">
    <button name="data" onclick="getData()">Click</button>
</form>

instead of using button tag, use input tag. Like this,

<form method="POST">
    <input type = "button" name="data" onclick="getData()" value="Click">
</form>

How to unpublish an app in Google Play Developer Console

To unpublish your app on the Google Play store:

  1. Go to https://market.android.com/publish/Home, and log in to your Google Play account.
  2. Click on the application you want to delete.
  3. Click on the Store Presence menu, and click the “Pricing and Distribution” item.
  4. Click Unpublish

How to "crop" a rectangular image into a square with CSS?

Assuming they do not have to be in IMG tags...

HTML:

<div class="thumb1">
</div>

CSS:

.thumb1 { 
  background: url(blah.jpg) 50% 50% no-repeat; /* 50% 50% centers image in div */
  width: 250px;
  height: 250px;
}

.thumb1:hover { YOUR HOVER STYLES HERE }

EDIT: If the div needs to link somewhere just adjust HTML and Styles like so:

HTML:

<div class="thumb1">
<a href="#">Link</a>
</div>

CSS:

.thumb1 { 
  background: url(blah.jpg) 50% 50% no-repeat; /* 50% 50% centers image in div */
  width: 250px;
  height: 250px;
}

.thumb1 a {
  display: block;
  width: 250px;
  height: 250px;
}

.thumb1 a:hover { YOUR HOVER STYLES HERE }

Note this could also be modified to be responsive, for example % widths and heights etc.

How to get df linux command output always in GB

If you also want it to be a command you can reference without remembering the arguments, you could simply alias it:

alias df-gb='df -BG'

So if you type:

df-gb

into a terminal, you'll get your intended output of the disk usage in GB.

EDIT: or even use just df -h to get it in a standard, human readable format.

http://www.thegeekstuff.com/2012/05/df-examples/

JPA and Hibernate - Criteria vs. JPQL or HQL

I usually use Criteria when I don't know what the inputs will be used on which pieces of data. Like on a search form where the user can enter any of 1 to 50 items and I don't know what they will be searching for. It is very easy to just append more to the criteria as I go through checking for what the user is searching for. I think it would be a little more troublesome to put an HQL query in that circumstance. HQL is great though when I know exactly what I want.

PermissionError: [Errno 13] Permission denied

I faced a similar problem. I am using Anaconda on windows and I resolved it as follows: 1) search for "Anaconda prompt" from the start menu 2) Right click and select "Run as administrator" 3) The follow the installation steps...

This takes care of the permission issues

Defining a `required` field in Bootstrap

If wont work in case you have something like : novalidate="novalidate" attached to your form.

How to use aria-expanded="true" to change a css property

You could use querySelector() with attribute selector '[attribute="value"]', then affect css rule using .style, as you can see in the example below:

_x000D_
_x000D_
document.querySelector('a[aria-expanded="true"]').style.backgroundColor = "#42DCA3";
_x000D_
<ul><li class="active">_x000D_
  <a href="#3a" class="btn btn-default btn-lg" data-toggle="tab" aria-expanded="true"> <span class="network-name">Google+ with aria expanded true</span></a>_x000D_
  </li>_x000D_
  <li>_x000D_
    <a href="#3a" class="btn btn-default btn-lg" data-toggle="tab" aria-expanded="false"> <span class="network-name">Google+ with aria expanded false</span></a>_x000D_
  </li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

jQuery solution :

If you want to use a jQuery solution you could simply use css() method :

$('a[aria-expanded="true"]').css('background-color','#42DCA3');

Hope this helps.

UIButton action in table view cell

We can create a closure for the button and use that in cellForRowAtIndexPath

class ClosureSleeve {
  let closure: () -> ()

  init(attachTo: AnyObject, closure: @escaping () -> ()) {
    self.closure = closure
    objc_setAssociatedObject(attachTo, "[\(arc4random())]", self,.OBJC_ASSOCIATION_RETAIN)
}

@objc func invoke() {
   closure()
 }
}

extension UIControl {
func addAction(for controlEvents: UIControlEvents = .primaryActionTriggered, action: @escaping () -> ()) {
  let sleeve = ClosureSleeve(attachTo: self, closure: action)
 addTarget(sleeve, action: #selector(ClosureSleeve.invoke), for: controlEvents)
 }
}

And then in cellForRowAtIndexPath

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
    let cell = youtableview.dequeueReusableCellWithIdentifier(identifier) as? youCell
    cell?.selectionStyle = UITableViewCell.SelectionStyle.none//swift 4 style

      button.addAction {
       //Do whatever you want to do when the button is tapped here
        print("button pressed")
      }

    return cell
 }

Getting vertical gridlines to appear in line plot in matplotlib

According to matplotlib documentation, The signature of the Axes class grid() method is as follows:

Axes.grid(b=None, which='major', axis='both', **kwargs)
Turn the axes grids on or off.

which can be ‘major’ (default), ‘minor’, or ‘both’ to control whether major tick grids, minor tick grids, or both are affected.

axis can be ‘both’ (default), ‘x’, or ‘y’ to control which set of gridlines are drawn.

So in order to show grid lines for both the x axis and y axis, we can use the the following code:

ax = plt.gca()
ax.grid(which='major', axis='both', linestyle='--')

This method gives us finer control over what to show for grid lines.

Regular expression to match DNS hostname or IP Address?

def isValidHostname(hostname):

    if len(hostname) > 255:
        return False
    if hostname[-1:] == ".":
        hostname = hostname[:-1]   # strip exactly one dot from the right,
                                   #  if present
    allowed = re.compile("(?!-)[A-Z\d-]{1,63}(?<!-)$", re.IGNORECASE)
    return all(allowed.match(x) for x in hostname.split("."))

My kubernetes pods keep crashing with "CrashLoopBackOff" but I can't find any log

kubectl -n <namespace-name> describe pod <pod name>

kubectl -n <namespace-name> logs -p  <pod name> 

Using JavaMail with TLS

We actually have some notification code in our product that uses TLS to send mail if it is available.

You will need to set the Java Mail properties. You only need the TLS one but you might need SSL if your SMTP server uses SSL.

Properties props = new Properties();
props.put("mail.smtp.starttls.enable","true");
props.put("mail.smtp.auth", "true");  // If you need to authenticate
// Use the following if you need SSL
props.put("mail.smtp.socketFactory.port", d_port);
props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
props.put("mail.smtp.socketFactory.fallback", "false");

You can then either pass this to a JavaMail Session or any other session instantiator like Session.getDefaultInstance(props).

Executing "SELECT ... WHERE ... IN ..." using MySQLdb

Maybe we can create a function to do what João proposed? Something like:

def cursor_exec(cursor, query, params):
    expansion_params= []
    real_params = []
    for p in params:
       if isinstance(p, (tuple, list)):
         real_params.extend(p)
         expansion_params.append( ("%s,"*len(p))[:-1] )
       else:
         real_params.append(p)
         expansion_params.append("%s")
    real_query = query % expansion_params
    cursor.execute(real_query, real_params)

Change the mouse pointer using JavaScript

Javascript is pretty good at manipulating css.

 document.body.style.cursor = *cursor-url*;
 //OR
 var elementToChange = document.getElementsByTagName("body")[0];
 elementToChange.style.cursor = "url('cursor url with protocol'), auto";

or with jquery:

$("html").css("cursor: url('cursor url with protocol'), auto");

Firefox will not work unless you specify a default cursor after the imaged one!

other cursor keywords

Also remember that IE6 only supports .cur and .ani cursors.

If cursor doesn't change: In case you are moving the element under the cursor relative to the cursor position (e.g. element dragging) you have to force a redraw on the element:

// in plain js
document.getElementById('parentOfElementToBeRedrawn').style.display = 'none';
document.getElementById('parentOfElementToBeRedrawn').style.display = 'block';
// in jquery
$('#parentOfElementToBeRedrawn').hide().show(0);

working sample:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>First jQuery-Enabled Page</title>
<style type="text/css">

div {
    height: 100px;
    width: 1000px;
    background-color: red;
}

</style>
<script type="text/javascript" src="jquery-1.3.2.js"></script></head>
<body>
<div>
hello with a fancy cursor!
</div>
</body>
<script type="text/javascript">
document.getElementsByTagName("body")[0].style.cursor = "url('http://wiki-devel.sugarlabs.org/images/e/e2/Arrow.cur'), auto";


</script>
</html>

Numpy converting array from float to strings

If you have an array of numbers and you want an array of strings, you can write:

strings = ["%.2f" % number for number in numbers]

If your numbers are floats, the array would be an array with the same numbers as strings with two decimals.

>>> a = [1,2,3,4,5]
>>> min_a, max_a = min(a), max(a)
>>> a_normalized = [float(x-min_a)/(max_a-min_a) for x in a]
>>> a_normalized
[0.0, 0.25, 0.5, 0.75, 1.0]
>>> a_strings = ["%.2f" % x for x in a_normalized]
>>> a_strings
['0.00', '0.25', '0.50', '0.75', '1.00']

Notice that it also works with numpy arrays:

>>> a = numpy.array([0.0, 0.25, 0.75, 1.0])
>>> print ["%.2f" % x for x in a]
['0.00', '0.25', '0.50', '0.75', '1.00']

A similar methodology can be used if you have a multi-dimensional array:

new_array = numpy.array(["%.2f" % x for x in old_array.reshape(old_array.size)])
new_array = new_array.reshape(old_array.shape)

Example:

>>> x = numpy.array([[0,0.1,0.2],[0.3,0.4,0.5],[0.6, 0.7, 0.8]])
>>> y = numpy.array(["%.2f" % w for w in x.reshape(x.size)])
>>> y = y.reshape(x.shape)
>>> print y
[['0.00' '0.10' '0.20']
 ['0.30' '0.40' '0.50']
 ['0.60' '0.70' '0.80']]

If you check the Matplotlib example for the function you are using, you will notice they use a similar methodology: build empty matrix and fill it with strings built with the interpolation method. The relevant part of the referenced code is:

colortuple = ('y', 'b')
colors = np.empty(X.shape, dtype=str)
for y in range(ylen):
    for x in range(xlen):
        colors[x, y] = colortuple[(x + y) % len(colortuple)]

surf = ax.plot_surface(X, Y, Z, rstride=1, cstride=1, facecolors=colors,
        linewidth=0, antialiased=False)

Programmatically go back to previous ViewController in Swift

This one works for me (Swift UI)

struct DetailView: View {
@Environment(\.presentationMode) var presentationMode: Binding<PresentationMode>

  var body: some View {
      VStack {
        Text("This is the detail view")
        Button(action: {
          self.presentationMode.wrappedValue.dismiss()
        }) {
          Text("Back")
        }
      }
    }
}

How to read XML response from a URL in java?

Ok I think I have solves the problem below is a working code

//
package xmlhttp;

import org.jdesktop.http.Response;

import org.jdesktop.http.Session;

import org.jdesktop.http.State;



public class GetXmlHttp{


    public static void main(String[] args) {

        getResponse();

    }

    public static void getResponse()
    {

        final Session session = new Session();

        try {
            String url="http://192.172.2.23:8080/geoserver/wfs?request=GetFeature&version=1.1.0&outputFormat=GML2&typeName=topp:networkcoverage,topp:tehsil&bbox=73.07846689124875,33.67929015631999,73.07946689124876,33.68029015632,EPSG:4326";
            final Response res=session.get(url);
            boolean notDone=true;
            do
            {
                System.out.print(session.getState().toString());

                if(session.getState()==State.DONE)
                {
                    String xml=res.toString();
                    System.out.println(xml);
                    notDone=false;


                }

            }while(notDone);

        } catch (Exception e1) {

            e1.printStackTrace();
        }


    }

}

How to repeat a char using printf?

There is no such thing. You'll have to either write a loop using printf or puts, or write a function that copies the string count times into a new string.

Android failed to load JS bundle

### Here is my solution

None of the above solutions can solve my problem but only follow the below steps working for me. Add in network-security-config.xml file

    <domain-config cleartextTrafficPermitted="true">
          <domain includeSubdomains="true">10.0.2.2</domain>
    </domain-config>
    ...

Then update AndroidManifest.xml file with

<application
+   android:networkSecurityConfig="@xml/network_security_config"
    ...

How do you create a REST client for Java?

Try looking at http-rest-client

https://github.com/g00dnatur3/http-rest-client

Here is a simple example:

RestClient client = RestClient.builder().build();
String geocoderUrl = "http://maps.googleapis.com/maps/api/geocode/json"
Map<String, String> params = Maps.newHashMap();
params.put("address", "beverly hills 90210");
params.put("sensor", "false");
JsonNode node = client.get(geocoderUrl, params, JsonNode.class);

The library takes care of json serialization and binding for you.

Here is another example,

RestClient client = RestClient.builder().build();
String url = ...
Person person = ...
Header header = client.create(url, person);
if (header != null) System.out.println("Location header is:" + header.value());

And one last example,

RestClient client = RestClient.builder().build();
String url = ...
Person person = client.get(url, null, Person.class); //no queryParams

Cheers!

HTML/JavaScript: Simple form validation on submit

HTML Form Element Validation

Run Function

<script>
    $("#validationForm").validation({
         button: "#btnGonder",
         onSubmit: function () {
             alert("Submit Process");
         },
         onCompleted: function () {
             alert("onCompleted");
         },
         onError: function () {
             alert("Error Process");
         }
    });
</script>

Go to example and download https://github.com/naimserin/Validation.

'Field required a bean of type that could not be found.' error spring restful API using mongodb

I had the same issue. My mistake was that I used @Service annotation on the Service Interface. The @Service annotation should be applied to the ServiceImpl class.

Sending Email in Android using JavaMail API without using the default/built-in app

Here are a lot solutions. However I think we must change the configuration of the GMail to allow accessing from less secure devices. Go to the link below and enable it. It works for me

https://myaccount.google.com/lesssecureapps?pli=1

jquery simple image slideshow tutorial

Here is my adaptation of Michael Soriano's tutorial. See below or in JSBin.

_x000D_
_x000D_
$(function() {_x000D_
  var theImage = $('ul#ss li img');_x000D_
  var theWidth = theImage.width();_x000D_
  //wrap into mother div_x000D_
  $('ul#ss').wrap('<div id="mother" />');_x000D_
  //assign height width and overflow hidden to mother_x000D_
  $('#mother').css({_x000D_
    width: function() {_x000D_
      return theWidth;_x000D_
    },_x000D_
    height: function() {_x000D_
      return theImage.height();_x000D_
    },_x000D_
    position: 'relative',_x000D_
    overflow: 'hidden'_x000D_
  });_x000D_
  //get total of image sizes and set as width for ul _x000D_
  var totalWidth = theImage.length * theWidth;_x000D_
  $('ul').css({_x000D_
    width: function() {_x000D_
      return totalWidth;_x000D_
    }_x000D_
  });_x000D_
_x000D_
  var ss_timer = setInterval(function() {_x000D_
    ss_next();_x000D_
  }, 3000);_x000D_
_x000D_
  function ss_next() {_x000D_
    var a = $(".active");_x000D_
    a.removeClass('active');_x000D_
_x000D_
    if (a.hasClass('last')) {_x000D_
      //last element -- loop_x000D_
      a.parent('ul').animate({_x000D_
        "margin-left": (0)_x000D_
      }, 1000);_x000D_
      a.siblings(":first").addClass('active');_x000D_
    } else {_x000D_
      a.parent('ul').animate({_x000D_
        "margin-left": (-(a.index() + 1) * theWidth)_x000D_
      }, 1000);_x000D_
      a.next().addClass('active');_x000D_
    }_x000D_
  }_x000D_
_x000D_
  // Cancel slideshow and move next manually on click_x000D_
  $('ul#ss li img').on('click', function() {_x000D_
    clearInterval(ss_timer);_x000D_
    ss_next();_x000D_
  });_x000D_
_x000D_
});
_x000D_
* {_x000D_
  margin: 0;_x000D_
  padding: 0;_x000D_
}_x000D_
#ss {_x000D_
  list-style: none;_x000D_
}_x000D_
#ss li {_x000D_
  float: left;_x000D_
}_x000D_
#ss img {_x000D_
  width: 200px;_x000D_
  height: 100px;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>_x000D_
<ul id="ss">_x000D_
  <li class="active">_x000D_
    <img src="http://leemark.github.io/better-simple-slideshow/demo/img/colorado-colors.jpg">_x000D_
  </li>_x000D_
  <li>_x000D_
    <img src="http://leemark.github.io/better-simple-slideshow/demo/img/monte-vista.jpg">_x000D_
  </li>_x000D_
  <li class="last">_x000D_
    <img src="http://leemark.github.io/better-simple-slideshow/demo/img/colorado.jpg">_x000D_
  </li>_x000D_
</ul>
_x000D_
_x000D_
_x000D_

Vue js error: Component template should contain exactly one root element

instead of using this

Vue.component('tabs', {
    template: `
        <div class="tabs">
          <ul>
            <li class="is-active"><a>Pictures</a></li>
            <li><a>Music</a></li>
            <li><a>Videos</a></li>
            <li><a>Documents</a></li>
          </ul>
        </div>

        <div class="tabs-content">
          <slot></slot>
        </div>
    `,
});

you should use


Vue.component('tabs', {
    template: `
      <div>
        <div class="tabs">
          <ul>
            <li class="is-active"><a>Pictures</a></li>
            <li><a>Music</a></li>
            <li><a>Videos</a></li>
            <li><a>Documents</a></li>
          </ul>
        </div>

        <div class="tabs-content">
          <slot></slot>
        </div>
      </div>
    `,
});

Cannot execute RUN mkdir in a Dockerfile

You can also simply use

WORKDIR /var/www/app

It will automatically create the folders if they don't exist.

Then switch back to the directory you need to be in.

Angular 2 - Using 'this' inside setTimeout

You need to use Arrow function ()=> ES6 feature to preserve this context within setTimeout.

// var that = this;                             // no need of this line
this.messageSuccess = true;

setTimeout(()=>{                           //<<<---using ()=> syntax
      this.messageSuccess = false;
 }, 3000);

jQuery DataTables: control table width

Be sure that all others parameters before bAutoWidth & aoColumns are correctly entered.Any wrong parameter before will break this functionality.

Convert string in base64 to image and save on filesystem in Python

You can use Pillow.

pip install Pillow



image = base64.b64decode(str(base64String))       
fileName = 'test.jpeg'

imagePath = FILE_UPLOAD_DIR + fileName

img = Image.open(io.BytesIO(image))
img.save(imagePath, 'jpeg')
return fileName

reference for complete source code: https://abhisheksharma.online/convert-base64-blob-to-image-file-in-python/

SqlException from Entity Framework - New transaction is not allowed because there are other threads running in the session

FYI: from a book and some lines adjusted because its stil valid:

Invoking SaveChanges() method begins a transaction which automatically rolls back all changes persisted to the database if an exception occurs before iteration completes; otherwise the transaction commits. You might be tempted to apply the method after each entity update or deletion rather than after iteration completes, especially when you're updating or deleting massive numbers of entities.

If you try to invoke SaveChanges() before all data has been processed, you incur a "New transaction is not allowed because there are other threads running in the session" exception. The exception occurs because SQL Server doesn't permit starting a new transaction on a connection that has a SqlDataReader open, even with Multiple Active Record Sets (MARS) enabled by the connection string (EF's default connection string enables MARS)

Sometimes its better to understand why things are happening ;-)

Flutter - Wrap text on overflow, like insert ellipsis or fade

Wrapping whose child elements are in a row or column, please wrap your column or row is new Flexible();

https://github.com/flutter/flutter/issues/4128

How to remove outliers from a dataset

I looked up for packages related to removing outliers, and found this package (surprisingly called "outliers"!): https://cran.r-project.org/web/packages/outliers/outliers.pdf
if you go through it you see different ways of removing outliers and among them I found rm.outlier most convenient one to use and as it says in the link above: "If the outlier is detected and confirmed by statistical tests, this function can remove it or replace by sample mean or median" and also here is the usage part from the same source:
"Usage

rm.outlier(x, fill = FALSE, median = FALSE, opposite = FALSE)

Arguments
x a dataset, most frequently a vector. If argument is a dataframe, then outlier is removed from each column by sapply. The same behavior is applied by apply when the matrix is given.
fill If set to TRUE, the median or mean is placed instead of outlier. Otherwise, the outlier(s) is/are simply removed.
median If set to TRUE, median is used instead of mean in outlier replacement. opposite if set to TRUE, gives opposite value (if largest value has maximum difference from the mean, it gives smallest and vice versa) "

Get value of div content using jquery

You can simply use the method text() of jQuery to get all the content of the text contained in the element. The text() method also returns the textual content of the child elements.

HTML Code:

<div id="box">
  <p>Lorem ipsum elit sit ut, consectetur adipiscing dolor.</p> 
</div>

JQuery Code:

  $(document).ready(function(){
    $("button").click(function(){
      var divContent = $('#box').text();
      alert(divContent);
    });
  });

You can see an example here: How to get the text content of an element with jQuery

Where to put the gradle.properties file

Actually there are 3 places where gradle.properties can be placed:

  1. Under gradle user home directory defined by the GRADLE_USER_HOME environment variable, which if not set defaults to USER_HOME/.gradle
  2. The sub-project directory (myProject2 in your case)
  3. The root project directory (under myProject)

Gradle looks for gradle.properties in all these places while giving precedence to properties definition based on the order above. So for example, for a property defined in gradle user home directory (#1) and the sub-project (#2) its value will be taken from gradle user home directory (#1).

You can find more details about it in gradle documentation here.

How to POST URL in data of a curl request

Perhaps you don't have to include the single quotes:

curl --request POST 'http://localhost/Service' --data "path=/xyz/pqr/test/&fileName=1.doc"

Update: Reading curl's manual, you could actually separate both fields with two --data:

curl --request POST 'http://localhost/Service' --data "path=/xyz/pqr/test/" --data "fileName=1.doc"

You could also try --data-binary:

curl --request POST 'http://localhost/Service' --data-binary "path=/xyz/pqr/test/" --data-binary "fileName=1.doc"

And --data-urlencode:

curl --request POST 'http://localhost/Service' --data-urlencode "path=/xyz/pqr/test/" --data-urlencode "fileName=1.doc"

Convert String to double in Java

Use new BigDecimal(string). This will guarantee proper calculation later.

As a rule of thumb - always use BigDecimal for sensitive calculations like money.

Example:

String doubleAsString = "23.23";
BigDecimal price = new BigDecimal(doubleAsString);
BigDecimal total = price.plus(anotherPrice);

android - setting LayoutParams programmatically

Just replace from bottom and add this

tv.setLayoutParams(new ViewGroup.LayoutParams(
    ViewGroup.LayoutParams.WRAP_CONTENT,
    ViewGroup.LayoutParams.WRAP_CONTENT));

before

llview.addView(tv);

Access denied for root user in MySQL command-line

Are you logging into MySQL as root? You have to explicitly grant privileges to your "regular" MySQL user account while logged in as MySQL root.

First set up a root account for your MySQL database.

In the terminal type:

mysqladmin -u root password 'password'

To log into MySQL, use this:

mysql -u root -p

To set the privileges manually start the server with the skip-grant-tables option, open mysql client and manually update the mysql.user table and/or the mysql.db tables. This can be a tedious task though so if what you need is an account with all privs I would do the following.

Start the server with the skip-grant-tables option

Start mysql client (without a username/password)

Issue the command

flush privileges;

which forces the grant tables to be loaded.

Create a new account with the GRANT command something like this (but replacing username and password with whatever you want to use.

GRANT ALL on *.* to 'username'@'localhost' identified by 'password';

Restart the server in normal mode (without skip-grant-tables) and log in with your newly created account.

Refer this MySQL docs.

Creating a left-arrow button (like UINavigationBar's "back" style) on a UIToolbar

I found that using the following, simple code did the trick (requires custom image in bundle):

// Creates a back button instead of default behaviour (displaying title of previous screen)
    UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"back_arrow.png"]
                                                                   style:UIBarButtonItemStyleBordered
                                                                  target:self
                                                                  action:@selector(backAction)];

    tipsDetailViewController.navigationItem.leftBarButtonItem = backButton;
    [backButton release];

Error: Node Sass does not yet support your current environment: Windows 64-bit with false

The link from the stack trace below helped me in resolving this issue.

Module build failed: Error: Node Sass does not yet support your current environment: Windows 64-bit with Unsupported runtime (64)
For more information on which environments are supported please see:
https://github.com/sass/node-sass/releases/tag/v4.7.2

This link(https://github.com/sass/node-sass/releases/tag/v4.7.2) clearly shows node versions which are supported.

    OS      Architecture    Node
    Windows x86 & x64       0.10, 0.12, 1, 2, 3, 4, 5, 6, 7, 8, 9
    ...     ...             ...    

After downgrading the node version to 8.11.1, executed npm install again. Got the following message.

Node Sass could not find a binding for your current environment: Windows 64-bit with Node.js 8.x

Found bindings for the following environments:
  - Windows 64-bit with Unsupported runtime (64)

This usually happens because your environment has changed since running `npm install`.
Run `npm rebuild node-sass --force` to build the binding for your current environment.

Finally,ran npm rebuild node-sass --force as instructed and all started working

Assert that a method was called in a Python unit test

You can mock out aw.Clear, either manually or using a testing framework like pymox. Manually, you'd do it using something like this:

class MyTest(TestCase):
  def testClear():
    old_clear = aw.Clear
    clear_calls = 0
    aw.Clear = lambda: clear_calls += 1
    aps.Request('nv2', aw)
    assert clear_calls == 1
    aw.Clear = old_clear

Using pymox, you'd do it like this:

class MyTest(mox.MoxTestBase):
  def testClear():
    aw = self.m.CreateMock(aps.Request)
    aw.Clear()
    self.mox.ReplayAll()
    aps.Request('nv2', aw)

Getting a UnhandledPromiseRejectionWarning when testing using mocha/chai

The assertion libraries in Mocha work by throwing an error if the assertion was not correct. Throwing an error results in a rejected promise, even when thrown in the executor function provided to the catch method.

.catch((error) => {
  assert.isNotOk(error,'Promise error');
  done();
});

In the above code the error objected evaluates to true so the assertion library throws an error... which is never caught. As a result of the error the done method is never called. Mocha's done callback accepts these errors, so you can simply end all promise chains in Mocha with .then(done,done). This ensures that the done method is always called and the error would be reported the same way as when Mocha catches the assertion's error in synchronous code.

it('should transition with the correct event', (done) => {
  const cFSM = new CharacterFSM({}, emitter, transitions);
  let timeout = null;
  let resolved = false;
  new Promise((resolve, reject) => {
    emitter.once('action', resolve);
    emitter.emit('done', {});
    timeout = setTimeout(() => {
      if (!resolved) {
        reject('Timedout!');
      }
      clearTimeout(timeout);
    }, 100);
  }).then(((state) => {
    resolved = true;
    assert(state.action === 'DONE', 'should change state');
  })).then(done,done);
});

I give credit to this article for the idea of using .then(done,done) when testing promises in Mocha.

How do I use JDK 7 on Mac OSX?

An easy way to install Java 7 on a Mac is by using Homebrew, thanks to the Homebrew Cask plugin (which is now installed by default).

Run this command to install Java 7:

brew cask install caskroom/versions/java7

Is there a splice method for strings?

I would like to offer a simpler alternative to both the Kumar/Cody and the Louis methods. On all the tests I ran, it performs as fast as the Louis method (see fiddle tests for benchmarks).

String.prototype.splice = function(startIndex,length,insertString){
    return this.substring(0,startIndex) + insertString + this.substring(startIndex + length);
};

You can use it like this:

var creditCardNumber = "5500000000000004";
var cardSuffix = creditCardNumber.splice(0,12,'****');
console.log(cardSuffix);  // output: ****0004

See Test Results: https://jsfiddle.net/0quz9q9m/5/

How to replace a char in string with an Empty character in C#.NET

If you are in a loop, let's say that you loop through a list of punctuation characters that you want to remove, you can do something like this:

      private const string PunctuationChars = ".,!?$";
          foreach (var word in words)
                {
                    var word_modified = word;

                    var modified = false;

                    foreach (var punctuationChar in PunctuationChars)
                    {
                        if (word.IndexOf(punctuationChar) > 0)
                        {
                            modified = true;
                            word_modified = word_modified.Replace("" + punctuationChar, "");


                        }
                    }
               //////////MORE CODE
               }

The trick being the following:

word_modified.Replace("" + punctuationChar, "");

How to override application.properties during production in Spring-Boot?

The spring configuration precedence is as follows.

  1. ServletConfig init Parameter
  2. ServletContext init parameter
  3. JNDI attributes
  4. System.getProperties()

So your configuration will be overridden at the command-line if you wish to do that. But the recommendation is to avoid overriding, though you can use multiple profiles.

Limiting the number of characters in a string, and chopping off the rest

For readability, I prefer this:

if (inputString.length() > maxLength) {
    inputString = inputString.substring(0, maxLength);
}

over the accepted answer.

int maxLength = (inputString.length() < MAX_CHAR)?inputString.length():MAX_CHAR;
inputString = inputString.substring(0, maxLength);

In Java, can you modify a List while iterating through it?

Use CopyOnWriteArrayList
and if you want to remove it, do the following:

for (Iterator<String> it = userList.iterator(); it.hasNext() ;)
{
    if (wordsToRemove.contains(word))
    {
        it.remove();
    }
}

how to stop Javascript forEach?

Breaking out of Array#forEach is not possible. (You can inspect the source code that implements it in Firefox on the linked page, to confirm this.)

Instead you should use a normal for loop:

function recurs(comment) {
    for (var i = 0; i < comment.comments.length; ++i) {
        var subComment = comment.comments[i];
        recurs(subComment);
        if (...) {
            break;
        }
    }
}

(or, if you want to be a little more clever about it and comment.comments[i] is always an object:)

function recurs(comment) {
    for (var i = 0, subComment; subComment = comment.comments[i]; ++i) {
        recurs(subComment);
        if (...) {
            break;
        }
    }
}

Redirecting output to $null in PowerShell, but ensuring the variable remains set

I'd prefer this way to redirect standard output (native PowerShell)...

($foo = someFunction) | out-null

But this works too:

($foo = someFunction) > $null

To redirect just standard error after defining $foo with result of "someFunction", do

($foo = someFunction) 2> $null

This is effectively the same as mentioned above.

Or to redirect any standard error messages from "someFunction" and then defining $foo with the result:

$foo = (someFunction 2> $null)

To redirect both you have a few options:

2>&1>$null
2>&1 | out-null

C++: variable 'std::ifstream ifs' has initializer but incomplete type

This seems to be answered - #include <fstream>.

The message means :-

incomplete type - the class has not been defined with a full class. The compiler has seen statements such as class ifstream; which allow it to understand that a class exists, but does not know how much memory the class takes up.

The forward declaration allows the compiler to make more sense of :-

void BindInput( ifstream & inputChannel ); 

It understands the class exists, and can send pointers and references through code without being able to create the class, see any data within the class, or call any methods of the class.

The has initializer seems a bit extraneous, but is saying that the incomplete object is being created.

Easy way to test an LDAP User's Credentials

Use ldapsearch to authenticate. The opends version might be used as follows:

ldapsearch --hostname hostname --port port \
    --bindDN userdn --bindPassword password \
    --baseDN '' --searchScope base 'objectClass=*' 1.1

Installing Google Protocol Buffers on mac

For some reason I need to use protobuf 2.4.1 in my project on OS X El Capitan. However homebrew has removed protobuf241 from its formula. I install it according @kksensei's answer manually and have to fix some error during the process.

During the make process, I get 3 error like following:

_x000D_
_x000D_
google/protobuf/message.cc:130:60: error: implicit instantiation of undefined template 'std::__1::basic_istream<char, std::__1::char_traits<char> >'_x000D_
_x000D_
  return ParseFromZeroCopyStream(&zero_copy_input) && input->eof();_x000D_
_x000D_
                                                           ^_x000D_
_x000D_
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/iosfwd:108:28: note: template is declared here_x000D_
_x000D_
    class _LIBCPP_TYPE_VIS basic_istream;_x000D_
_x000D_
                           ^_x000D_
_x000D_
google/protobuf/message.cc:135:67: error: implicit instantiation of undefined template 'std::__1::basic_istream<char, std::__1::char_traits<char> >'_x000D_
_x000D_
  return ParsePartialFromZeroCopyStream(&zero_copy_input) && input->eof();_x000D_
_x000D_
                                                                  ^_x000D_
_x000D_
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/iosfwd:108:28: note: template is declared here_x000D_
_x000D_
    class _LIBCPP_TYPE_VIS basic_istream;_x000D_
_x000D_
                           ^_x000D_
_x000D_
google/protobuf/message.cc:175:16: error: implicit instantiation of undefined template 'std::__1::basic_ostream<char, std::__1::char_traits<char> >'_x000D_
_x000D_
  return output->good();_x000D_
_x000D_
               ^_x000D_
_x000D_
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/c++/v1/iosfwd:110:28: note: template is declared here_x000D_
_x000D_
    class _LIBCPP_TYPE_VIS basic_ostream;_x000D_
_x000D_
                           ^
_x000D_
_x000D_
_x000D_

(Sorry, I dont know how to attach code when the code contains '`' )

If you get the same error, please edit src/google/protobuf/message.cc, add #include <istream> at the top of the file and do $ make again and should get no errors. After that do $ sudo make install. When install finished $protoc --version should display the correct result.

How to pass a JSON array as a parameter in URL

You can pass your json Input as a POST request along with authorization header in this way

public static JSONObject getHttpConn(String json){
        JSONObject jsonObject=null;
        try {
            HttpPost httpPost=new HttpPost("http://google.com/");
            org.apache.http.client.HttpClient client = HttpClientBuilder.create().build();
            StringEntity stringEntity=new StringEntity("d="+json);

            httpPost.addHeader("content-type", "application/x-www-form-urlencoded");
            String authorization="test:test@123";
            String encodedAuth = "Basic " + Base64.encode(authorization.getBytes());        
            httpPost.addHeader("Authorization", security.get("Authorization"));
            httpPost.setEntity(stringEntity);
            HttpResponse reponse=client.execute(httpPost);
            InputStream inputStream=reponse.getEntity().getContent();
            String jsonResponse=IOUtils.toString(inputStream);
            jsonObject=JSONObject.fromObject(jsonResponse);
            } catch (UnsupportedEncodingException e) {

            e.printStackTrace();
        } catch (ClientProtocolException e) {

            e.printStackTrace();
        } catch (IOException e) {

            e.printStackTrace();
        }
        return jsonObject;


    }

This Method will return a json response.In same way you can use GET method

ExecutorService, how to wait for all tasks to finish

You can use ExecutorService.invokeAll method, It will execute all task and wait till all threads finished their task.

Here is complete javadoc

You can also user overloaded version of this method to specify the timeout.

Here is sample code with ExecutorService.invokeAll

public class Test {
    public static void main(String[] args) throws InterruptedException, ExecutionException {
        ExecutorService service = Executors.newFixedThreadPool(3);
        List<Callable<String>> taskList = new ArrayList<>();
        taskList.add(new Task1());
        taskList.add(new Task2());
        List<Future<String>> results = service.invokeAll(taskList);
        for (Future<String> f : results) {
            System.out.println(f.get());
        }
    }

}

class Task1 implements Callable<String> {
    @Override
    public String call() throws Exception {
        try {
            Thread.sleep(2000);
            return "Task 1 done";
        } catch (Exception e) {
            e.printStackTrace();
            return " error in task1";
        }
    }
}

class Task2 implements Callable<String> {
    @Override
    public String call() throws Exception {
        try {
            Thread.sleep(3000);
            return "Task 2 done";
        } catch (Exception e) {
            e.printStackTrace();
            return " error in task2";
        }
    }
}

Python 2.7.10 error "from urllib.request import urlopen" no module named request

Try using urllib2:

https://docs.python.org/2/library/urllib2.html

This line should work to replace urlopen:

from urllib2 import urlopen

Tested in Python 2.7 on Macbook Pro

Try posting a link to the git in question.

Java: how to initialize String[]?

String Declaration:

String str;

String Initialization

String[] str=new String[3];//if we give string[2] will get Exception insted
str[0]="Tej";
str[1]="Good";
str[2]="Girl";

String str="SSN"; 

We can get individual character in String:

char chr=str.charAt(0);`//output will be S`

If I want to to get individual character Ascii value like this:

System.out.println((int)chr); //output:83

Now i want to convert Ascii value into Charecter/Symbol.

int n=(int)chr;
System.out.println((char)n);//output:S

Make a simple fade in animation in Swift?

Swift 5

Other answers are correct, but in my case I need to handle other properties also (alpha, animate, completion). Because of this, I modified a bit to expose these parameters as below:

extension UIView {
    /// Helper function to update view's alpha with animation
    /// - Parameter alpha: View's alpha
    /// - Parameter animate: Indicate alpha changing with animation or not
    /// - Parameter duration: Indicate time for animation
    /// - Parameter completion: Completion block after alpha changing is finished
    func set(alpha: CGFloat, animate: Bool, duration: TimeInterval = 0.3, completion: ((Bool) -> Void)? = nil) {
        let animation = { (view: UIView) in
            view.alpha = alpha
        }
    
        if animate {
            UIView.animate(withDuration: duration, animations: {
                animation(self)
            }, completion: { finished in
                completion?(finished)
            })
        } else {
            layer.removeAllAnimations()
            animation(self)
            completion?(true)
        }
    }
}

Difference between rake db:migrate db:reset and db:schema:load

As far as I understand, it is going to drop your database and re-create it based on your db/schema.rb file. That is why you need to make sure that your schema.rb file is always up to date and under version control.

WiX tricks and tips

Add a checkbox to the exit dialog to launch the app, or the helpfile.

...

<!-- CA to launch the exe after install -->
<CustomAction Id          ="CA.StartAppOnExit"
              FileKey     ="YourAppExeId"
              ExeCommand  =""
              Execute     ="immediate"
              Impersonate ="yes"
              Return      ="asyncNoWait" />

<!-- CA to launch the help file -->
<CustomAction Id         ="CA.LaunchHelp"
              Directory  ="INSTALLDIR"
              ExeCommand ='[WindowsFolder]hh.exe IirfGuide.chm'
              Execute    ="immediate"
              Return     ="asyncNoWait" />

<Property Id="WIXUI_EXITDIALOGOPTIONALCHECKBOXTEXT"
          Value="Launch MyApp when setup exits." />

<UI>
  <Publish Dialog  ="ExitDialog"
           Control ="Finish"
           Order   ="1"
           Event   ="DoAction"
           Value   ="CA.StartAppOnExit">WIXUI_EXITDIALOGOPTIONALCHECKBOXTEXT</Publish>
</UI>

If you do it this way, the "standard" appearance isn't quite right. The checkbox is always a gray background, while the dialog is white:

alt text http://www.dizzymonkeydesign.com/blog/misc/adding-and-customizing-dlgs-in-wix-3/images/exit_dlg_1.gif

One way around this is to specify your own custom ExitDialog, with a differently-located checkbox. This works, but seems like a lot of work just to change the color of one control. Another way to solve the same thing is to post-process the generated MSI to change the X,Y fields in the Control table for that particular CheckBox control. The javascript code looks like this:

var msiOpenDatabaseModeTransact = 1;
var filespec = WScript.Arguments(0);
var installer = new ActiveXObject("WindowsInstaller.Installer");
var database = installer.OpenDatabase(filespec, msiOpenDatabaseModeTransact);
var sql = "UPDATE `Control` SET `Control`.`Height` = '18', `Control`.`Width` = '170'," +
          " `Control`.`Y`='243', `Control`.`X`='10' " +
          "WHERE `Control`.`Dialog_`='ExitDialog' AND " + 
          "  `Control`.`Control`='OptionalCheckBox'";
var view = database.OpenView(sql);
view.Execute();
view.Close();
database.Commit();

Running this code as a command-line script (using cscript.exe) after the MSI is generated (from light.exe) will produce an ExitDialog that looks more professional:

alt text http://www.dizzymonkeydesign.com/blog/misc/adding-and-customizing-dlgs-in-wix-3/images/exit_dlg_2.gif

How to show validation message below each textbox using jquery?

Here you go:

JS:

$('form').on('submit', function (e) {
    e.preventDefault();

    if (!$('#email').val()) 
        $('#email').parent().append('<span class="error">Please enter your email address.</span>');


    if(!$('#password').val())
         $('#password').parent().append('<span class="error">Please enter your password.</span>');
});

CSS:

@charset "utf-8";
/* CSS Document */

/* ---------- FONTAWESOME ---------- */
/* ---------- http://fortawesome.github.com/Font-Awesome/ ---------- */
/* ---------- http://weloveiconfonts.com/ ---------- */

@import url(http://weloveiconfonts.com/api/?family=fontawesome);

/* ---------- ERIC MEYER'S RESET CSS ---------- */
/* ---------- http://meyerweb.com/eric/tools/css/reset/ ---------- */

@import url(http://meyerweb.com/eric/tools/css/reset/reset.css);

/* ---------- FONTAWESOME ---------- */

[class*="fontawesome-"]:before {
  font-family: 'FontAwesome', sans-serif;
}

/* ---------- GENERAL ---------- */

body {
    background-color: #C0C0C0;
    color: #000;
    font-family: "Varela Round", Arial, Helvetica, sans-serif;
    font-size: 16px;
    line-height: 1.5em;
}

input {
    border: none;
    font-family: inherit;
    font-size: inherit;
    font-weight: inherit;
    line-height: inherit;
    -webkit-appearance: none;
}

/* ---------- LOGIN ---------- */

#login {
    margin: 50px auto;
    width: 400px;
}

#login h2 {
    background-color: #f95252;
    -webkit-border-radius: 20px 20px 0 0;
    -moz-border-radius: 20px 20px 0 0;
    border-radius: 20px 20px 0 0;
    color: #fff;
    font-size: 28px;
    padding: 20px 26px;
}

#login h2 span[class*="fontawesome-"] {
    margin-right: 14px;
}

#login fieldset {
    background-color: #fff;
    -webkit-border-radius: 0 0 20px 20px;
    -moz-border-radius: 0 0 20px 20px;
    border-radius: 0 0 20px 20px;
    padding: 20px 26px;
}

#login fieldset div {
    color: #777;
    margin-bottom: 14px;
}

#login fieldset p:last-child {
    margin-bottom: 0;
}

#login fieldset input {
    -webkit-border-radius: 3px;
    -moz-border-radius: 3px;
    border-radius: 3px;
}

#login fieldset .error {
    display: block;
     color: #FF1000;
    font-size: 12px;
}
}

#login fieldset input[type="email"], #login fieldset input[type="password"] {
    background-color: #eee;
    color: #777;
    padding: 4px 10px;
    width: 328px;
}

#login fieldset input[type="submit"] {
    background-color: #33cc77;
    color: #fff;
    display: block;
    margin: 0 auto;
    padding: 4px 0;
    width: 100px;
}

#login fieldset input[type="submit"]:hover {
    background-color: #28ad63;
}

HTML:

<div id="login">

<h2><span class="fontawesome-lock"></span>Sign In</h2>

<form action="javascript:void(0);" method="POST">

    <fieldset>

        <div><label for="email">E-mail address</label></div>
        <div><input type="email" id="email" /></div>

        <div><label for="password">Password</label></div>
        <div><input type="password" id="password" /></div> <!-- JS because of IE support; better: placeholder="Email" -->

        <div><input type="submit" value="Sign In"></div>

    </fieldset>

</form>

And the fiddle: jsfiddle

How to select all records from one table that do not exist in another table?

Watch out for pitfalls. If the field Name in Table1 contain Nulls you are in for surprises. Better is:

SELECT name
FROM table2
WHERE name NOT IN
    (SELECT ISNULL(name ,'')
     FROM table1)

Read file line by line using ifstream in C++

Use ifstream to read data from a file:

std::ifstream input( "filename.ext" );

If you really need to read line by line, then do this:

for( std::string line; getline( input, line ); )
{
    ...for each line in input...
}

But you probably just need to extract coordinate pairs:

int x, y;
input >> x >> y;

Update:

In your code you use ofstream myfile;, however the o in ofstream stands for output. If you want to read from the file (input) use ifstream. If you want to both read and write use fstream.

"This project is incompatible with the current version of Visual Studio"

In case you came here looking for the issue with ".smproj" file, it is because you are missing SQL Server Analysis Services(SSAS). To over come this, install SQL Server Data Tools(SSDT) in your system, restart your Visual Studio and it will work.

Thanks.

How do I export a project in the Android studio?

From the menu:

Build|Generate Signed APK

or

Build|Build APK

(the latter if you don't need a signed one to publish to the Play Store)

Base64 Decoding in iOS 7+

Swift 3+

let plainString = "foo"

Encoding

let plainData = plainString.data(using: .utf8)
let base64String = plainData?.base64EncodedString()
print(base64String!) // Zm9v

Decoding

if let decodedData = Data(base64Encoded: base64String!),
   let decodedString = String(data: decodedData, encoding: .utf8) {
  print(decodedString) // foo
}

Swift < 3

let plainString = "foo"

Encoding

let plainData = plainString.dataUsingEncoding(NSUTF8StringEncoding)
let base64String = plainData?.base64EncodedStringWithOptions(NSDataBase64EncodingOptions(rawValue: 0))
print(base64String!) // Zm9v

Decoding

let decodedData = NSData(base64EncodedString: base64String!, options: NSDataBase64DecodingOptions(rawValue: 0))
let decodedString = NSString(data: decodedData, encoding: NSUTF8StringEncoding)
print(decodedString) // foo

Objective-C

NSString *plainString = @"foo";

Encoding

NSData *plainData = [plainString dataUsingEncoding:NSUTF8StringEncoding];
NSString *base64String = [plainData base64EncodedStringWithOptions:0];
NSLog(@"%@", base64String); // Zm9v

Decoding

NSData *decodedData = [[NSData alloc] initWithBase64EncodedString:base64String options:0];
NSString *decodedString = [[NSString alloc] initWithData:decodedData encoding:NSUTF8StringEncoding];
NSLog(@"%@", decodedString); // foo 

formatFloat : convert float number to string

Try this

package main

import "fmt"
import "strconv"

func FloatToString(input_num float64) string {
    // to convert a float number to a string
    return strconv.FormatFloat(input_num, 'f', 6, 64)
}

func main() {
    fmt.Println(FloatToString(21312421.213123))
}

If you just want as many digits precision as possible, then the special precision -1 uses the smallest number of digits necessary such that ParseFloat will return f exactly. Eg

strconv.FormatFloat(input_num, 'f', -1, 64)

Personally I find fmt easier to use. (Playground link)

fmt.Printf("x = %.6f\n", 21312421.213123)

Or if you just want to convert the string

fmt.Sprintf("%.6f", 21312421.213123)

Syntax for a for loop in ruby

limit = array.length;
for counter in 0..limit
 --- make some actions ---
end

the other way to do that is the following

3.times do |n|
  puts n;
end

thats will print 0, 1, 2, so could be used like array iterator also

Think that variant better fit to the author's needs

Reading int values from SqlDataReader

based on Sam Holder's answer, you could make an extension method for that

namespace adonet.extensions
{
  public static class AdonetExt
  {
    public static int GetInt32(this SqlDataReader reader, string columnName)
    {
      return reader.GetInt32(reader.GetOrdinal(columnName));
    }
  }
}

and use it like this

using adonet.extensions;

//...

int farmsize = reader.GetInt32("farmsize");

assuming there is no GetInt32(string) already in SqlDataReader - if there is any, just use some other method name instead

How can I add C++11 support to Code::Blocks compiler?

Use g++ -std=c++11 -o <output_file_name> <file_to_be_compiled>

JavaScript getElementByID() not working

You need to put the JavaScript at the end of the body tag.

It doesn't find it because it's not in the DOM yet!

You can also wrap it in the onload event handler like this:

window.onload = function() {
var refButton = document.getElementById( 'btnButton' );
refButton.onclick = function() {
   alert( 'I am clicked!' );
}
}

Simple mediaplayer play mp3 from file path?

Here is the code to set up a MediaPlayer to play off of the SD card:

String PATH_TO_FILE = "/sdcard/music.mp3";    
mediaPlayer = new  MediaPlayer();
mediaPlayer.setDataSource(PATH_TO_FILE);
mediaPlayer.prepare();   
mediaPlayer.start()

You can see the full example here. Let me know if you have any problems.

How to lowercase a pandas dataframe string column if it has missing values?

Pandas >= 0.25: Remove Case Distinctions with str.casefold

Starting from v0.25, I recommend using the "vectorized" string method str.casefold if you're dealing with unicode data (it works regardless of string or unicodes):

s = pd.Series(['lower', 'CAPITALS', np.nan, 'SwApCaSe'])
s.str.casefold()

0       lower
1    capitals
2         NaN
3    swapcase
dtype: object

Also see related GitHub issue GH25405.

casefold lends itself to more aggressive case-folding comparison. It also handles NaNs gracefully (just as str.lower does).

But why is this better?

The difference is seen with unicodes. Taking the example in the python str.casefold docs,

Casefolding is similar to lowercasing but more aggressive because it is intended to remove all case distinctions in a string. For example, the German lowercase letter 'ß' is equivalent to "ss". Since it is already lowercase, lower() would do nothing to 'ß'; casefold() converts it to "ss".

Compare the output of lower for,

s = pd.Series(["der Fluß"])
s.str.lower()

0    der fluß
dtype: object

Versus casefold,

s.str.casefold()

0    der fluss
dtype: object

Also see Python: lower() vs. casefold() in string matching and converting to lowercase.

How to create <input type=“text”/> dynamically

Maybe the method document.createElement(); is what you're looking for.

How to split and modify a string in NodeJS?

If you're using lodash and in the mood for a too-cute-for-its-own-good one-liner:

_.map(_.words('123, 124, 234,252'), _.add.bind(1, 1));

It's surprisingly robust thanks to lodash's powerful parsing capabilities.

If you want one that will also clean non-digit characters out of the string (and is easier to follow...and not quite so cutesy):

_.chain('123, 124, 234,252, n301')
   .replace(/[^\d,]/g, '')
   .words()
   .map(_.partial(_.add, 1))
   .value();

2017 edit:

I no longer recommend my previous solution. Besides being overkill and already easy to do without a third-party library, it makes use of _.chain, which has a variety of issues. Here's the solution I would now recommend:

const str = '123, 124, 234,252';
const arr = str.split(',').map(n => parseInt(n, 10) + 1);

My old answer is still correct, so I'll leave it for the record, but there's no need to use it nowadays.

Where does error CS0433 "Type 'X' already exists in both A.dll and B.dll " come from?

I'm converting an old asp.net (v 1 or 2) web site to run under .net 4.5 as a web application.

My solution was to move the user control event handler delegates that were causing the problem to a separate physical file:

//move this line to a new physical file:
public delegate void LocationSearchedEventHandler( object sender );

public partial class controls_Drives_LocationAddPanel : UserControl
{
    public event LocationAddedEventHandler LocationAdded;
    protected virtual void OnLocationAdded(LocationAddEventArg e)
    {

How can I capture packets in Android?

Option 1 - Android PCAP

Limitation

Android PCAP should work so long as:

Your device runs Android 4.0 or higher (or, in theory, the few devices which run Android 3.2). Earlier versions of Android do not have a USB Host API

Option 2 - TcpDump

Limitation

Phone should be rooted

Option 3 - bitshark (I would prefer this)

Limitation

Phone should be rooted

Reason - the generated PCAP files can be analyzed in WireShark which helps us in doing the analysis.

Other Options without rooting your phone

  1. tPacketCapture

https://play.google.com/store/apps/details?id=jp.co.taosoftware.android.packetcapture&hl=en

Advantages

Using tPacketCapture is very easy, captured packet save into a PCAP file that can be easily analyzed by using a network protocol analyzer application such as Wireshark.

  1. You can route your android mobile traffic to PC and capture the traffic in the desktop using any network sniffing tool.

http://lifehacker.com/5369381/turn-your-windows-7-pc-into-a-wireless-hotspot

How to scroll to top of long ScrollView layout?

I faced Same Problem When i am using Scrollview inside View Flipper or Dialog that case scrollViewObject.fullScroll(ScrollView.FOCUS_UP) returns false so that case scrollViewObject.smoothScrollTo(0, 0) is Worked for me

Scroll Focus Top

Giving multiple URL patterns to Servlet Filter

If an URL pattern starts with /, then it's relative to the context root. The /Admin/* URL pattern would only match pages on http://localhost:8080/EMS2/Admin/* (assuming that /EMS2 is the context path), but you have them actually on http://localhost:8080/EMS2/faces/Html/Admin/*, so your URL pattern never matches.

You need to prefix your URL patterns with /faces/Html as well like so:

<url-pattern>/faces/Html/Admin/*</url-pattern>

You can alternatively also just reconfigure your web project structure/configuration so that you can get rid of the /faces/Html path in the URLs so that you can just open the page by for example http://localhost:8080/EMS2/Admin/Upload.xhtml.

Your filter mapping syntax is all fine. However, a simpler way to specify multiple URL patterns is to just use only one <filter-mapping> with multiple <url-pattern> entries:

<filter-mapping>
    <filter-name>LoginFilter</filter-name>
    <url-pattern>/faces/Html/Employee/*</url-pattern>
    <url-pattern>/faces/Html/Admin/*</url-pattern>
    <url-pattern>/faces/Html/Supervisor/*</url-pattern>
</filter-mapping>

Equal sized table cells to fill the entire width of the containing table

Using table-layout: fixed as a property for table and width: calc(100%/3); for td (assuming there are 3 td's). With these two properties set, the table cells will be equal in size.

Refer to the demo.

How can I loop through a C++ map of maps?

for(std::map<std::string, std::map<std::string, std::string> >::iterator outer_iter=map.begin(); outer_iter!=map.end(); ++outer_iter) {
    for(std::map<std::string, std::string>::iterator inner_iter=outer_iter->second.begin(); inner_iter!=outer_iter->second.end(); ++inner_iter) {
        std::cout << inner_iter->second << std::endl;
    }
}

or nicer in C++0x:

for(auto outer_iter=map.begin(); outer_iter!=map.end(); ++outer_iter) {
    for(auto inner_iter=outer_iter->second.begin(); inner_iter!=outer_iter->second.end(); ++inner_iter) {
        std::cout << inner_iter->second << std::endl;
    }
}

What is the difference between square brackets and parentheses in a regex?

Your team's advice is almost right, except for the mistake that was made. Once you find out why, you will never forget it. Take a look at this mistake.

/^(7|8|9)\d{9}$/

What this does:

  • ^ and $ denotes anchored matches, which asserts that the subpattern in between these anchors are the entire match. The string will only match if the subpattern matches the entirety of it, not just a section.
  • () denotes a capturing group.
  • 7|8|9 denotes matching either of 7, 8, or 9. It does this with alternations, which is what the pipe operator | does — alternating between alternations. This backtracks between alternations: If the first alternation is not matched, the engine has to return before the pointer location moved during the match of the alternation, to continue matching the next alternation; Whereas the character class can advance sequentially. See this match on a regex engine with optimizations disabled:
Pattern: (r|f)at
Match string: carat

alternations

Pattern: [rf]at
Match string: carat

class

  • \d{9} matches nine digits. \d is a shorthanded metacharacter, which matches any digits.
/^[7|8|9][\d]{9}$/

Look at what it does:

  • ^ and $ denotes anchored matches as well.
  • [7|8|9] is a character class. Any characters from the list 7, |, 8, |, or 9 can be matched, thus the | was added in incorrectly. This matches without backtracking.
  • [\d] is a character class that inhabits the metacharacter \d. The combination of the use of a character class and a single metacharacter is a bad idea, by the way, since the layer of abstraction can slow down the match, but this is only an implementation detail and only applies to a few of regex implementations. JavaScript is not one, but it does make the subpattern slightly longer.
  • {9} indicates the previous single construct is repeated nine times in total.

The optimal regex is /^[789]\d{9}$/, because /^(7|8|9)\d{9}$/ captures unnecessarily which imposes a performance decrease on most regex implementations ( happens to be one, considering the question uses keyword var in code, this probably is JavaScript). The use of which runs on PCRE for preg matching will optimize away the lack of backtracking, however we're not in PHP either, so using classes [] instead of alternations | gives performance bonus as the match does not backtrack, and therefore both matches and fails faster than using your previous regular expression.

Replace a string in shell script using a variable

Single quotes are very strong. Once inside, there's nothing you can do to invoke variable substitution, until you leave. Use double quotes instead:

echo $LINE | sed -e "s/12345678/$replace/g"

How do I run a Java program from the command line on Windows?

Assuming the file is called "CopyFile.java", do the following:

javac CopyFile.java
java -cp . CopyFile

The first line compiles the source code into executable byte code. The second line executes it, first adding the current directory to the class path (just in case).

How to clear the logs properly for a Docker container?

You can set up logrotate to clear the logs periodically.

Example file in /etc/logrotate.d/docker-logs

/var/lib/docker/containers/*/*.log {
 rotate 7
 daily
 compress
 size=50M
 missingok
 delaycompress
 copytruncate
}

Regex match entire words only

Get all "words" in a string

/([^\s]+)/g

Basically ^/s means break on spaces (or match groups of non-spaces)
Don't forget the g for Greedy

jQuery autohide element after 5 seconds

$(function() {
    // setTimeout() function will be fired after page is loaded
    // it will wait for 5 sec. and then will fire
    // $("#successMessage").hide() function
    setTimeout(function() {
        $("#successMessage").hide('blind', {}, 500)
    }, 5000);
});

Note: In order to make you jQuery function work inside setTimeout you should wrap it inside

function() { ... }

ASP.NET Identity - HttpContext has no extension method for GetOwinContext

ARGH!

I found it... I didn't have an extra package, called Microsoft.Owin.Host.SystemWeb

Once i searched and installed this, it worked.

Now - i am not sure if i just missed everything, though found NO reference to such a library or package when going through various tutorials. It also didn't get installed when i installed all this Identity framework... Not sure if it were just me..

EDIT Although it's in the Microsoft.Owin.Host.SystemWeb assembly it is an extension method in the System.Web namespace, so you need to have the reference to the former, and be using the latter.

time delayed redirect?

 <script type="text/JavaScript">
      setTimeout("location.href = 'http://www.your_site.com';",1500);
 </script>

How to count number of files in each directory?

THis could be another way to browse through the directory structures and provide depth results.

find . -type d  | awk '{print "echo -n \""$0"  \";ls -l "$0" | grep -v total | wc -l" }' | sh 

Android SDK Setup under Windows 7 Pro 64 bit

I initially had this problem and I believe it was because I did not have the 64 bit version of Eclipse.

Get content of a cell given the row and column numbers

Try =index(ARRAY, ROW, COLUMN)

where: Array: select the whole sheet Row, Column: Your row and column references

That should be easier to understand to those looking at the formula.

How npm start runs a server on port 8000

You can change the port in the console by running the following on Windows:

SET PORT=8000

For Mac, Linux or Windows WSL use the following:

export PORT=8000

The export sets the environment variable for the current shell and all child processes like npm that might use it.

If you want the environment variable to be set just for the npm process, precede the command with the environment variable like this (on Mac and Linux and Windows WSL):

PORT=8000 npm run start

Comparing Arrays of Objects in JavaScript

I tried JSON.stringify() and worked for me.

let array1 = [1,2,{value:'alpha'}] , array2 = [{value:'alpha'},'music',3,4];

JSON.stringify(array1) // "[1,2,{"value":"alpha"}]"

JSON.stringify(array2) // "[{"value":"alpha"},"music",3,4]"

JSON.stringify(array1) === JSON.stringify(array2); // false

How do I obtain the frequencies of each value in an FFT?

The first bin in the FFT is DC (0 Hz), the second bin is Fs / N, where Fs is the sample rate and N is the size of the FFT. The next bin is 2 * Fs / N. To express this in general terms, the nth bin is n * Fs / N.

So if your sample rate, Fs is say 44.1 kHz and your FFT size, N is 1024, then the FFT output bins are at:

  0:   0 * 44100 / 1024 =     0.0 Hz
  1:   1 * 44100 / 1024 =    43.1 Hz
  2:   2 * 44100 / 1024 =    86.1 Hz
  3:   3 * 44100 / 1024 =   129.2 Hz
  4: ...
  5: ...
     ...
511: 511 * 44100 / 1024 = 22006.9 Hz

Note that for a real input signal (imaginary parts all zero) the second half of the FFT (bins from N / 2 + 1 to N - 1) contain no useful additional information (they have complex conjugate symmetry with the first N / 2 - 1 bins). The last useful bin (for practical aplications) is at N / 2 - 1, which corresponds to 22006.9 Hz in the above example. The bin at N / 2 represents energy at the Nyquist frequency, i.e. Fs / 2 ( = 22050 Hz in this example), but this is in general not of any practical use, since anti-aliasing filters will typically attenuate any signals at and above Fs / 2.

Tomcat won't stop or restart

It seems Tomcat was actually stopped. I started it and it started fine. Thanks all.

Form Submit jQuery does not work

Some time you have to give all the form element into a same div.

example:-

If you are using ajax submit with modal.

So all the elements are in modal body.

Some time we put submit button in modal footer.

How can I get the intersection, union, and subset of arrays in Ruby?

If Multiset extends from the Array class

x = [1, 1, 2, 4, 7]
y = [1, 2, 2, 2]
z = [1, 1, 3, 7]

UNION

x.union(y)           # => [1, 2, 4, 7]      (ONLY IN RUBY 2.6)
x.union(y, z)        # => [1, 2, 4, 7, 3]   (ONLY IN RUBY 2.6)
x | y                # => [1, 2, 4, 7]

DIFFERENCE

x.difference(y)      # => [4, 7] (ONLY IN RUBY 2.6)
x.difference(y, z)   # => [4] (ONLY IN RUBY 2.6)
x - y                # => [4, 7]

INTERSECTION

x & y                # => [1, 2]

For more info about the new methods in Ruby 2.6, you can check this blog post about its new features

Hexadecimal string to byte array in C

No. But it's relatively trivial to achieve using sscanf in a loop.

Meaning of numbers in "col-md-4"," col-xs-1", "col-lg-2" in Bootstrap

The Bootstrap grid system has four classes:
xs (for phones)
sm (for tablets)
md (for desktops)
lg (for larger desktops)

The classes above can be combined to create more dynamic and flexible layouts.

Tip: Each class scales up, so if you wish to set the same widths for xs and sm, you only need to specify xs.

OK, the answer is easy, but read on:

col-lg- stands for column large = 1200px
col-md- stands for column medium = 992px
col-xs- stands for column extra small = 768px

The pixel numbers are the breakpoints, so for example col-xs is targeting the element when the window is smaller than 768px(likely mobile devices)...

I also created the image below to show how the grid system works, in this examples I use them with 3, like col-lg-6 to show you how the grid system work in the page, look at how lg, md and xs are responsive to the window size:

Bootstrap grid system, col-*-6

Set value of hidden input with jquery

To make it with jquery, make this way:

var test = $("input[name=testing]:hidden");
test.val('work!');

Or

var test = $("input[name=testing]:hidden").val('work!');

See working in this fiddle.

Iterate through 2 dimensional array

Just change the indexes. i and j....in the loop, plus if you're dealing with Strings you have to use concat and initialize the variable to an empty Strong otherwise you'll get an exception.

String string="";
for (int i = 0; i<array.length; i++){
    for (int j = 0; j<array[i].length; j++){
        string = string.concat(array[j][i]);
    } 
}
System.out.println(string)

detect key press in python?

More things can be done with keyboard module. You can install this module using pip install keyboard Here are some of the methods:


Method #1:

Using the function read_key():

import keyboard

while True:
    if keyboard.read_key() == "p":
        print("You pressed p")
        break

This is gonna break the loop as the key p is pressed.


Method #2:

Using function wait:

import keyboard

keyboard.wait("p")
print("You pressed p")

It will wait for you to press p and continue the code as it is pressed.


Method #3:

Using the function on_press_key:

import keyboard

keyboard.on_press_key("p", lambda _:print("You pressed p"))

It needs a callback function. I used _ because the keyboard function returns the keyboard event to that function.

Once executed, it will run the function when the key is pressed. You can stop all hooks by running this line:

keyboard.unhook_all()

Method #4:

This method is sort of already answered by user8167727 but I disagree with the code they made. It will be using the function is_pressed but in an other way:

import keyboard

while True:
    if keyboard.is_pressed("p"):
        print("You pressed p")
        break

It will break the loop as p is pressed.


Notes:

  • keyboard will read keypresses from the whole OS.
  • keyboard requires root on linux

Number of regex matches

#An example for counting matched groups
import re

pattern = re.compile(r'(\w+).(\d+).(\w+).(\w+)', re.IGNORECASE)
search_str = "My 11 Char String"

res = re.match(pattern, search_str)
print(len(res.groups())) # len = 4  
print (res.group(1) ) #My
print (res.group(2) ) #11
print (res.group(3) ) #Char
print (res.group(4) ) #String

How to solve could not create the virtual machine error of Java Virtual Machine Launcher?

May be this can help you- Add the system variable _JAVA_OPTIONS and in the "new variable value" add "-Xmx1024M" Xmx sets the maximum heap memory size

Lambda function in list comprehensions

The big difference is that the first example actually invokes the lambda f(x), while the second example doesn't.

Your first example is equivalent to [(lambda x: x*x)(x) for x in range(10)] while your second example is equivalent to [f for x in range(10)].

PHP: Call to undefined function: simplexml_load_string()

Make sure that you have php-xml module installed and enabled in php.ini.

You can also change response format to json which is easier to handle. In that case you have to only add &format=json to url query string.

$rest_url = "http://api.facebook.com/restserver.php?method=links.getStats&format=json&urls=".urlencode($source_url);

And then use json_decode() to retrieve data in your script:

$result = json_decode($content, true);
$fb_like_count = $result['like_count'];

Get total number of items on Json object?

Is that your actual code? A javascript object (which is what you've given us) does not have a length property, so in this case exampleArray.length returns undefined rather than 5.

This stackoverflow explains the length differences between an object and an array, and this stackoverflow shows how to get the 'size' of an object.

How to make the main content div fill height of screen with css

There is a CSS unit called viewport height / viewport width.

Example

.mainbody{height: 100vh;} similarly html,body{width: 100vw;}

or 90vh = 90% of the viewport height.

**IE9+ and most modern browsers.

Query to list all users of a certain group

memberOf (in AD) is stored as a list of distinguishedNames. Your filter needs to be something like:

(&(objectCategory=user)(memberOf=cn=MyCustomGroup,ou=ouOfGroup,dc=subdomain,dc=domain,dc=com))

If you don't yet have the distinguished name, you can search for it with:

(&(objectCategory=group)(cn=myCustomGroup))

and return the attribute distinguishedName. Case may matter.

Extracting specific columns from a data frame

There are two obvious choices: Joshua Ulrich's df[,c("A","B","E")] or

df[,c(1,2,5)]

as in

> df <- data.frame(A=c(1,2),B=c(3,4),C=c(5,6),D=c(7,7),E=c(8,8),F=c(9,9)) 
> df
  A B C D E F
1 1 3 5 7 8 9
2 2 4 6 7 8 9
> df[,c(1,2,5)]
  A B E
1 1 3 8
2 2 4 8
> df[,c("A","B","E")]
  A B E
1 1 3 8
2 2 4 8

Where value in column containing comma delimited values

Just came to know about this when I was searching for a solution to a similar problem. SQL has a new keyword called CONTAINS you can use that. For more details see http://msdn.microsoft.com/en-us/library/ms187787.aspx

Python: convert string to byte array

An alternative to get a byte array is to encode the string in ascii: b=s.encode('ascii').

How can I get column names from a table in SQL Server?

select *
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME='tableName'

This is better than getting from sys.columns because it shows DATA_TYPE directly.

Spring Boot - How to log all requests and responses with exceptions in single place?

Currently Spring Boot has the Actuator feature to get the logs of requests and responses.

But you can also get the logs using Aspect(AOP).

Aspect provides you with annotations like: @Before, @AfterReturning, @AfterThrowing etc.

@Before logs the request, @AfterReturning logs the response and @AfterThrowing logs the error message, You may not need all endpoints' log, so you can apply some filters on the packages.

Here are some examples:

For Request:

@Before("within(your.package.where.endpoints.are..*)")
    public void endpointBefore(JoinPoint p) {
        if (log.isTraceEnabled()) {
            log.trace(p.getTarget().getClass().getSimpleName() + " " + p.getSignature().getName() + " START");
            Object[] signatureArgs = p.getArgs();


            ObjectMapper mapper = new ObjectMapper();
            mapper.enable(SerializationFeature.INDENT_OUTPUT);
            try {

                if (signatureArgs[0] != null) {
                    log.trace("\nRequest object: \n" + mapper.writeValueAsString(signatureArgs[0]));
                }
            } catch (JsonProcessingException e) {
            }
        }
    }

Here @Before("within(your.package.where.endpoints.are..*)") has the package path. All endpoints within this package will generate the log.

For Response:

@AfterReturning(value = ("within(your.package.where.endpoints.are..*)"),
            returning = "returnValue")
    public void endpointAfterReturning(JoinPoint p, Object returnValue) {
        if (log.isTraceEnabled()) {
            ObjectMapper mapper = new ObjectMapper();
            mapper.enable(SerializationFeature.INDENT_OUTPUT);
            try {
                log.trace("\nResponse object: \n" + mapper.writeValueAsString(returnValue));
            } catch (JsonProcessingException e) {
                System.out.println(e.getMessage());
            }
            log.trace(p.getTarget().getClass().getSimpleName() + " " + p.getSignature().getName() + " END");
        }
    }

Here @AfterReturning("within(your.package.where.endpoints.are..*)") has the package path. All endpoints within this package will generate the log. Also Object returnValue contains the response.

For Exception:

@AfterThrowing(pointcut = ("within(your.package.where.endpoints.are..*)"), throwing = "e")
public void endpointAfterThrowing(JoinPoint p, Exception e) throws DmoneyException {
    if (log.isTraceEnabled()) {
        System.out.println(e.getMessage());

        e.printStackTrace();


        log.error(p.getTarget().getClass().getSimpleName() + " " + p.getSignature().getName() + " " + e.getMessage());
    }
}

Here @AfterThrowing(pointcut = ("within(your.package.where.endpoints.are..*)"), throwing = "e") has the package path. All endpoints within this package will generate the log. Also Exception e contains the error response.

Here is the full code:

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import org.apache.log4j.Logger;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

@Aspect
@Order(1)
@Component
@ConditionalOnExpression("${endpoint.aspect.enabled:true}")
public class EndpointAspect {
    static Logger log = Logger.getLogger(EndpointAspect.class);

    @Before("within(your.package.where.is.endpoint..*)")
    public void endpointBefore(JoinPoint p) {
        if (log.isTraceEnabled()) {
            log.trace(p.getTarget().getClass().getSimpleName() + " " + p.getSignature().getName() + " START");
            Object[] signatureArgs = p.getArgs();


            ObjectMapper mapper = new ObjectMapper();
            mapper.enable(SerializationFeature.INDENT_OUTPUT);
            try {

                if (signatureArgs[0] != null) {
                    log.trace("\nRequest object: \n" + mapper.writeValueAsString(signatureArgs[0]));
                }
            } catch (JsonProcessingException e) {
            }
        }
    }

    @AfterReturning(value = ("within(your.package.where.is.endpoint..*)"),
            returning = "returnValue")
    public void endpointAfterReturning(JoinPoint p, Object returnValue) {
        if (log.isTraceEnabled()) {
            ObjectMapper mapper = new ObjectMapper();
            mapper.enable(SerializationFeature.INDENT_OUTPUT);
            try {
                log.trace("\nResponse object: \n" + mapper.writeValueAsString(returnValue));
            } catch (JsonProcessingException e) {
                System.out.println(e.getMessage());
            }
            log.trace(p.getTarget().getClass().getSimpleName() + " " + p.getSignature().getName() + " END");
        }
    }


    @AfterThrowing(pointcut = ("within(your.package.where.is.endpoint..*)"), throwing = "e")
    public void endpointAfterThrowing(JoinPoint p, Exception e) throws Exception {
        if (log.isTraceEnabled()) {
            System.out.println(e.getMessage());

            e.printStackTrace();


            log.error(p.getTarget().getClass().getSimpleName() + " " + p.getSignature().getName() + " " + e.getMessage());
        }
    }
}

Here, using @ConditionalOnExpression("${endpoint.aspect.enabled:true}") you can enable/disable the log. just add endpoint.aspect.enabled:true into the application.property and control the log

More info about AOP visit here:

Spring docs about AOP

Sample article about AOP

How many values can be represented with n bits?

The thing you are missing is which encoding scheme is being used. There are different ways to encode binary numbers. Look into signed number representations. For 9 bits, the ranges and the amount of numbers that can be represented will differ depending on the system used.

Difference between git pull and git pull --rebase

Suppose you have two commits in local branch:

      D---E master
     /
A---B---C---F origin/master

After "git pull", will be:

      D--------E  
     /          \
A---B---C---F----G   master, origin/master

After "git pull --rebase", there will be no merge point G. Note that D and E become different commits:

A---B---C---F---D'---E'   master, origin/master

How can I list the contents of a directory in Python?

The os module handles all that stuff.

os.listdir(path)

Return a list containing the names of the entries in the directory given by path. The list is in arbitrary order. It does not include the special entries '.' and '..' even if they are present in the directory.

Availability: Unix, Windows.

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

This should do:

Response.AddHeader("Content-Disposition", "attachment;filename="+ YourFilename)

Storing Images in DB - Yea or Nay?

I would go with the file system approach. No need to create or maintain a DB with images, it will save you some major headaches in the long run.

Turning off auto indent when pasting text into vim

From vim: ]p

From outside: "*]p or "+]p

batch file Copy files with certain extensions from multiple directories into one directory

Just use the XCOPY command with recursive option

xcopy c:\*.doc k:\mybackup /sy

/s will make it "recursive"

How to prevent a file from direct URL Access?

Based on your comments looks like this is what you need:

RewriteCond %{HTTP_REFERER} !^http://(www\.)?localhost/ [NC] 
RewriteRule \.(jpe?g|gif|bmp|png)$ - [F,NC]

I have tested it on my localhost and it seems to be working fine.

Shell equality operators (=, ==, -eq)

It depends on the Test Construct around the operator. Your options are double parentheses, double brackets, single brackets, or test.

If you use (()), you are testing arithmetic equality with == as in C:

$ (( 1==1 )); echo $?
0
$ (( 1==2 )); echo $?
1

(Note: 0 means true in the Unix sense and a failed test results in a non-zero number.)

Using -eq inside of double parentheses is a syntax error.

If you are using [] (or single brackets) or [[]] (or double brackets), or test you can use one of -eq, -ne, -lt, -le, -gt, or -ge as an arithmetic comparison.

$ [ 1 -eq 1 ]; echo $?
0
$ [ 1 -eq 2 ]; echo $?
1
$ test 1 -eq 1; echo $?
0

The == inside of single or double brackets (or the test command) is one of the string comparison operators:

$ [[ "abc" == "abc" ]]; echo $?
0
$ [[ "abc" == "ABC" ]]; echo $?
1

As a string operator, = is equivalent to ==. Also, note the whitespace around = or ==: it’s required.

While you can do [[ 1 == 1 ]] or [[ $(( 1+1 )) == 2 ]] it is testing the string equality — not the arithmetic equality.

So -eq produces the result probably expected that the integer value of 1+1 is equal to 2 even though the right-hand side is a string and has a trailing space:

$ [[ $(( 1+1 )) -eq  "2 " ]]; echo $?
0

While a string comparison of the same picks up the trailing space and therefore the string comparison fails:

$ [[ $(( 1+1 )) == "2 " ]]; echo $?
1

And a mistaken string comparison can produce a completely wrong answer. 10 is lexicographically less than 2, so a string comparison returns true or 0. So many are bitten by this bug:

$ [[ 10 < 2 ]]; echo $?
0

The correct test for 10 being arithmetically less than 2 is this:

$ [[ 10 -lt 2 ]]; echo $?
1

In comments, there is a question about the technical reason why using the integer -eq on strings returns true for strings that are not the same:

$ [[ "yes" -eq "no" ]]; echo $?
0

The reason is that Bash is untyped. The -eq causes the strings to be interpreted as integers if possible including base conversion:

$ [[ "0x10" -eq 16 ]]; echo $?
0
$ [[ "010" -eq 8 ]]; echo $?
0
$ [[ "100" -eq 100 ]]; echo $?
0

And 0 if Bash thinks it is just a string:

$ [[ "yes" -eq 0 ]]; echo $?
0
$ [[ "yes" -eq 1 ]]; echo $?
1

So [[ "yes" -eq "no" ]] is equivalent to [[ 0 -eq 0 ]]


Last note: Many of the Bash specific extensions to the Test Constructs are not POSIX and therefore may fail in other shells. Other shells generally do not support [[...]] and ((...)) or ==.

changing textbox border colour using javascript

I'm agree with Vicente Plata you should try using jQuery IMHO is the best javascript library. You can create a class in your CSS file and just do the following with jquery:

$('#fName').addClass('name_of_the_class'); 

and that's all, and of course you won't be worried about incompatibility of the browsers, that's jquery's team problem :D LOL

Using HeapDumpOnOutOfMemoryError parameter for heap dump for JBoss

I found it hard to decipher what is meant by "working directory of the VM". In my example, I was using the Java Service Wrapper program to execute a jar - the dump files were created in the directory where I had placed the wrapper program, e.g. c:\myapp\bin. The reason I discovered this is because the files can be quite large and they filled up the hard drive before I discovered their location.

Apache Name Virtual Host with SSL

First you need NameVirtualHost ip:443 in you config file! You probably have one with 80 at the end, but you will also need one with 443.

Second you need a *.domain certificate (wildcard) (it is possible to make one)

Third you can make only something.domain webs in one ip (because of the certificate)

How can I view the Git history in Visual Studio Code?

Git Graph seems like a decent extension. After installing, you can open the graph view from the bottom status bar.

Read a file line by line with VB.NET

Replaced the reader declaration with this one and now it works!

Dim reader As New StreamReader(filetoimport.Text, Encoding.Default)

Encoding.Default represents the ANSI code page that is set under Windows Control Panel.

Timeout a command in bash without unnecessary delay

See also the http://www.pixelbeat.org/scripts/timeout script the functionality of which has been integrated into newer coreutils

How to interactively (visually) resolve conflicts in SourceTree / git

From SourceTree, click on Tools->Options. Then on the "General" tab, make sure to check the box to allow SourceTree to modify your Git config files.

Then switch to the "Diff" tab. On the lower half, use the drop down to select the external program you want to use to do the diffs and merging. I've installed KDiff3 and like it well enough. When you're done, click OK.

Now when there is a merge, you can go under Actions->Resolve Conflicts->Launch External Merge Tool.

How can I display a JavaScript object?

I needed a way to recursively print the object, which pagewil's answer provided (Thanks!). I updated it a little bit to include a way to print up to a certain level, and to add spacing so that it is properly indented based on the current level that we are in so that it is more readable.

// Recursive print of object
var print = function( o, maxLevel, level ) {
    if ( typeof level == "undefined" ) {
        level = 0;
    }
    if ( typeof level == "undefined" ) {
        maxLevel = 0;
    }

    var str = '';
    // Remove this if you don't want the pre tag, but make sure to remove
    // the close pre tag on the bottom as well
    if ( level == 0 ) {
        str = '<pre>';
    }

    var levelStr = '';
    for ( var x = 0; x < level; x++ ) {
        levelStr += '    ';
    }

    if ( maxLevel != 0 && level >= maxLevel ) {
        str += levelStr + '...</br>';
        return str;
    }

    for ( var p in o ) {
        if ( typeof o[p] == 'string' ) {
            str += levelStr +
                p + ': ' + o[p] + ' </br>';
        } else {
            str += levelStr +
                p + ': { </br>' + print( o[p], maxLevel, level + 1 ) + levelStr + '}</br>';
        }
    }

    // Remove this if you don't want the pre tag, but make sure to remove
    // the open pre tag on the top as well
    if ( level == 0 ) {
        str += '</pre>';
    }
    return str;
};

Usage:

var pagewilsObject = {
    name: 'Wilson Page',
    contact: {
        email: '[email protected]',
        tel: '123456789'
    }  
}

// Recursive of whole object
$('body').append( print(pagewilsObject) ); 

// Recursive of myObject up to 1 level, will only show name 
// and that there is a contact object
$('body').append( print(pagewilsObject, 1) ); 

Script @php artisan package:discover handling the post-autoload-dump event returned with error code 1

This happened to me because I had a ddd() or dd();die; in my routes/web.php file I forgot about.

How to my "exe" from PyCharm project

You cannot directly save a Python file as an exe and expect it to work -- the computer cannot automatically understand whatever code you happened to type in a text file. Instead, you need to use another program to transform your Python code into an exe.

I recommend using a program like Pyinstaller. It essentially takes the Python interpreter and bundles it with your script to turn it into a standalone exe that can be run on arbitrary computers that don't have Python installed (typically Windows computers, since Linux tends to come pre-installed with Python).

To install it, you can either download it from the linked website or use the command:

pip install pyinstaller

...from the command line. Then, for the most part, you simply navigate to the folder containing your source code via the command line and run:

pyinstaller myscript.py

You can find more information about how to use Pyinstaller and customize the build process via the documentation.


You don't necessarily have to use Pyinstaller, though. Here's a comparison of different programs that can be used to turn your Python code into an executable.

dynamic_cast and static_cast in C++

No, not easily. The compiler assigns a unique identity to every class, that information is referenced by every object instance, and that is what gets inspected at runtime to determine if a dynamic cast is legal. You could create a standard base class with this information and operators to do the runtime inspection on that base class, then any derived class would inform the base class of its place in the class hierarchy and any instances of those classes would be runtime-castable via your operations.

edit

Here's an implementation that demonstrates one technique. I'm not claiming the compiler uses anything like this, but I think it demonstrates the concepts:

class SafeCastableBase
{
public:
    typedef long TypeID;
    static TypeID s_nextTypeID;
    static TypeID GetNextTypeID()
    {
        return s_nextTypeID++;
    }
    static TypeID GetTypeID()
    {
        return 0;
    }
    virtual bool CanCastTo(TypeID id)
    {
        if (GetTypeID() != id) { return false; }
        return true;
    }
    template <class Target>
    static Target *SafeCast(SafeCastableBase *pSource)
    {
        if (pSource->CanCastTo(Target::GetTypeID()))
        {
            return (Target*)pSource;
        }
        return NULL;
    }
};
SafeCastableBase::TypeID SafeCastableBase::s_nextTypeID = 1;

class TypeIDInitializer
{
public:
    TypeIDInitializer(SafeCastableBase::TypeID *pTypeID)
    {
        *pTypeID = SafeCastableBase::GetNextTypeID();
    }
};

class ChildCastable : public SafeCastableBase
{
public:
    static TypeID s_typeID;
    static TypeID GetTypeID()
    {
        return s_typeID;
    }
    virtual bool CanCastTo(TypeID id)
    {
        if (GetTypeID() != id) { return SafeCastableBase::CanCastTo(id); }
        return true;
    }
};
SafeCastableBase::TypeID ChildCastable::s_typeID;

TypeIDInitializer ChildCastableInitializer(&ChildCastable::s_typeID);

class PeerChildCastable : public SafeCastableBase
{
public:
    static TypeID s_typeID;
    static TypeID GetTypeID()
    {
        return s_typeID;
    }
    virtual bool CanCastTo(TypeID id)
    {
        if (GetTypeID() != id) { return SafeCastableBase::CanCastTo(id); }
        return true;
    }
};
SafeCastableBase::TypeID PeerChildCastable::s_typeID;

TypeIDInitializer PeerChildCastableInitializer(&PeerChildCastable::s_typeID);

int _tmain(int argc, _TCHAR* argv[])
{
    ChildCastable *pChild = new ChildCastable();
    SafeCastableBase *pBase = new SafeCastableBase();
    PeerChildCastable *pPeerChild = new PeerChildCastable();
    ChildCastable *pSameChild = SafeCastableBase::SafeCast<ChildCastable>(pChild);
    SafeCastableBase *pBaseToChild = SafeCastableBase::SafeCast<SafeCastableBase>(pChild);
    ChildCastable *pNullDownCast = SafeCastableBase::SafeCast<ChildCastable>(pBase);
    SafeCastableBase *pBaseToPeerChild = SafeCastableBase::SafeCast<SafeCastableBase>(pPeerChild);
    ChildCastable *pNullCrossCast = SafeCastableBase::SafeCast<ChildCastable>(pPeerChild);
    return 0;
}

Float a div right, without impacting on design

Try setting its position to absolute. That takes it out of the flow of the document.

Adding Multiple Values in ArrayList at a single index

import java.util.*;
public class HelloWorld{

 public static void main(String []args){
  List<String> threadSafeList = new ArrayList<String>();
    threadSafeList.add("A");
    threadSafeList.add("D");
    threadSafeList.add("F");

Set<String> threadSafeList1 = new TreeSet<String>();
    threadSafeList1.add("B");
    threadSafeList1.add("C");
    threadSafeList1.add("E");
    threadSafeList1.addAll(threadSafeList);


 List mainList = new ArrayList();   
 mainList.addAll(Arrays.asList(threadSafeList1));
 Iterator<String> mainList1 = mainList.iterator();
 while(mainList1.hasNext()){
 System.out.printf("total : %s %n", mainList1.next());
 }
}
}

Error LNK2019 unresolved external symbol _main referenced in function "int __cdecl invoke_main(void)" (?invoke_main@@YAHXZ)

If you use CMake you have to set WIN32 flag in add_executable

add_executable(${name} WIN32 ${source_files})

See CMake Doc for more information.

How to find out if an installed Eclipse is 32 or 64 bit version?

Help -> About Eclipse -> Installation Details -> tab Configuration

Look for -arch, and below it you'll see either x86_64 (meaning 64bit) or x86 (meaning 32bit).

Run script with rc.local: script works, but not at boot

I am using CentOS 7.

$ cd  /etc/profile.d

$ vim yourstuffs.sh

Type the following into the yourstuffs.sh script.

type whatever you want here to execute

export LD_LIBRARY_PATH=/usr/local/cuda-7.0/lib64:$LD_LIBRARY_PATH

Save and reboot the OS.

MySQL: Can't create table (errno: 150)

If the PK table is created in one CHARSET and then you create FK table in another CHARSET..then also you might get this error...I too got this error but after changing the charset to PK charset then it got executed without errors

create table users
(
------------
-------------
)DEFAULT CHARSET=latin1;


create table Emp
(
---------
---------
---------
FOREIGN KEY (userid) REFERENCES users(id) on update cascade on delete cascade)ENGINE=InnoDB, DEFAULT CHARSET=latin1;

Best C++ IDE or Editor for Windows

Visual studio is the most up to date and probably "best" free ide. Dev C++ is a little dated, and mingw doesn't compile most of boost, (except regex). Most of the other compilers are dated and fading, like mars and borland. But you can use whatever you like!

ES6 map an array of objects, to return an array of objects with new keys

You just need to wrap object in ()

_x000D_
_x000D_
var arr = [{_x000D_
  id: 1,_x000D_
  name: 'bill'_x000D_
}, {_x000D_
  id: 2,_x000D_
  name: 'ted'_x000D_
}]_x000D_
_x000D_
var result = arr.map(person => ({ value: person.id, text: person.name }));_x000D_
console.log(result)
_x000D_
_x000D_
_x000D_

Anyway to prevent the Blue highlighting of elements in Chrome when clicking quickly?

I had similar issue with <input type="range" /> and I solved it with

-webkit-tap-highlight-color: transparent;

_x000D_
_x000D_
input[type="range"]{
  -webkit-tap-highlight-color: transparent;
}
_x000D_
 <input type="range" id="volume" name="demo"
         min="0" max="11">
  <label for="volume">Demo</label>
_x000D_
_x000D_
_x000D_

How do I make a checkbox required on an ASP.NET form?

I typically perform the validation on the client side:

<asp:checkbox id="chkTerms" text=" I agree to the terms" ValidationGroup="vg" runat="Server"  />
<asp:CustomValidator id="vTerms"
                ClientValidationFunction="validateTerms" 
                ErrorMessage="<br/>Terms and Conditions are required." 
                ForeColor="Red"
                Display="Static"
                EnableClientScript="true"
                ValidationGroup="vg"
                runat="server"/>

<asp:Button ID="btnSubmit" OnClick="btnSubmit_Click" CausesValidation="true" Text="Submit" ValidationGroup="vg" runat="server" />

<script>
    function validateTerms(source, arguments) {
        var $c = $('#<%= chkTerms.ClientID %>');
        if($c.prop("checked")){
            arguments.IsValid = true;
        } else {
            arguments.IsValid = false;
        }
    }
</script>       

When to use which design pattern?

Learn them and slowly you'll be able to reconize and figure out when to use them. Start with something simple as the singleton pattern :)

if you want to create one instance of an object and just ONE. You use the singleton pattern. Let's say you're making a program with an options object. You don't want several of those, that would be silly. Singleton makes sure that there will never be more than one. Singleton pattern is simple, used a lot, and really effective.

What's the difference between console.dir and console.log?

Following Felix Klings advice I tried it out in my chrome browser.

console.dir([1,2]) gives the following output:

Array[2]
 0: 1
 1: 2
 length: 2
 __proto__: Array[0]

While console.log([1,2]) gives the following output:

[1, 2]

So I believe console.dir() should be used to get more information like prototype etc in arrays and objects.

What are the recommendations for html <base> tag?

It makes pages easier for offline viewing; you can put the fully qualified URL in the base tag and then your remote resources will load properly.

How to adjust gutter in Bootstrap 3 grid system?

You could create a CSS class for this and apply it to your columns. Since the gutter (spacing between columns) is controlled by padding in Bootstrap 3, adjust the padding accordingly:

.col {
  padding-right:7px;
  padding-left:7px;
}

Demo: http://bootply.com/93473

EDIT If you only want the spacing between columns you can select all cols except first and last like this..

.col:not(:first-child,:last-child) {
  padding-right:7px;
  padding-left:7px;
}

Updated Bootply

For Bootstrap 4 see: Remove gutter space for a specific div only

Why does comparing strings using either '==' or 'is' sometimes produce a different result?

is is identity testing and == is equality testing. This means is is a way to check whether two things are the same things, or just equivalent.

Say you've got a simple person object. If it is named 'Jack' and is '23' years old, it's equivalent to another 23-year-old Jack, but it's not the same person.

class Person(object):
   def __init__(self, name, age):
       self.name = name
       self.age = age

   def __eq__(self, other):
       return self.name == other.name and self.age == other.age

jack1 = Person('Jack', 23)
jack2 = Person('Jack', 23)

jack1 == jack2 # True
jack1 is jack2 # False

They're the same age, but they're not the same instance of person. A string might be equivalent to another, but it's not the same object.

Error Microsoft.Web.Infrastructure, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35

It appears that Microsoft.Web.Infrastructure.dll is not being installed in the GAC, even if .net (4.0 or 4.5 or other) are installed successfully on Windows Server. On localhost (typically Windows client), it seems like it is being in the GAC when the tools/platform (Visual Studio etc.) are installed.

As one possible fix, please try the following:

  1. Run the following command in the Package Manager Console. (If you are using Visual Studio, this can be reached via menu options "Tools --> Library Package Manager --> Package Manager Console:)

    PM> Install-Package Microsoft.Web.Infrastructure
    

    You will see the following messages if it is successfully installed.

    Successfully installed 'Microsoft.Web.Infrastructure 1.0.0.0'.
    Successfully added 'Microsoft.Web.Infrastructure 1.0.0.0' to Web.
    
  2. You will notice that Microsoft.Web.Infrastructure.dll has now been added as a Reference (can be seen in the references folder of your project in in Solution Explorer)

  3. If you look at the properties of this reference you will notice that "Copy Local" has been set to "True" by default.

  4. Now when you "Publish " your project, Microsoft.Web.Infrastructure.dll will be deployed.

Can someone explain mappedBy in JPA and Hibernate?

By specifying the @JoinColumn on both models you don't have a two way relationship. You have two one way relationships, and a very confusing mapping of it at that. You're telling both models that they "own" the IDAIRLINE column. Really only one of them actually should! The 'normal' thing is to take the @JoinColumn off of the @OneToMany side entirely, and instead add mappedBy to the @OneToMany.

@OneToMany(cascade = CascadeType.ALL, mappedBy="airline")
public Set<AirlineFlight> getAirlineFlights() {
    return airlineFlights;
}

That tells Hibernate "Go look over on the bean property named 'airline' on the thing I have a collection of to find the configuration."

bash assign default value

Use a colon:

: ${A:=hello}

The colon is a null command that does nothing and ignores its arguments. It is built into bash so a new process is not created.

Execute SQL script to create tables and rows

If you have password for your dB then

mysql -u <username> -p <DBName> < yourfile.sql

How do you convert a JavaScript date to UTC?

Browsers may differ, and you should also remember to not trust any info generated by the client, that being said, the below statement works for me (Google Chrome v24 on Mac OS X 10.8.2)

var utcDate = new Date(new Date().getTime());


edit: "How is this different than just new Date()?" see here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date

  • If no arguments are provided, the constructor creates a JavaScript Date object for the current date and time according to system settings.
  • Note: Where Date is called as a constructor with more than one argument, the specifed arguments represent local time. If UTC is desired, use new Date(Date.UTC(...)) with the same arguments. (note: Date.UTC() returns the number of millisecond since 1970-01-01 00:00:00 UTC)

Adding the 60000 * Date.getTimezoneOffset() as previous answers have stated is incorrect. First, you must think of all Dates/Times as already being UTC with a timezone modifier for display purposes.

Again, browsers may differ, however, Date.getTime() returns the number of milliseconds since 1970-01-01 UTC/GMT. If you create a new Date using this number as I do above, it will be UTC/GMT. However, if you display it by calling .toString() it will appear to be in your local timezone because .toString() uses your local timezone, not the timezone of the Date object it is called on.

I have also found that if you call .getTimezoneOffset() on a date, it will return your local timezone, not the timezone of the date object you called it on (I can't verify this to be standard however).

In my browser, adding 60000 * Date.getTimezoneOffset() creates a DateTime that is not UTC. However when displayed within my browser (ex: .toString() ), it displays a DateTime in my local timezone that would be correct UTC time if timezone info is ignored.

ld cannot find -l<library>

you can add the Path to coinhsl lib to LD_LIBRARY_PATH variable. May be that will help.

export LD_LIBRARY_PATH=/xx/yy/zz:$LD_LIBRARY_PATH

where /xx/yy/zz represent the path to coinhsl lib.

Converting Swagger specification JSON to HTML documentation

See the swagger-api/swagger-codegen project on GitHub ; the project README shows how to use it to generate static HTML. See Generating static html api documentation.

If you want to view the swagger.json you can install the Swagger UI and run it. You just deploy it on a web server (the dist folder after you clone the repo from GitHub) and view the Swagger UI in your browser. It's a JavaScript app.

How to replace all special character into a string using C#

Yes, you can use regular expressions in C#.

Using regular expressions with C#:

using System.Text.RegularExpressions;

string your_String = "Hello@Hello&Hello(Hello)";
string my_String =  Regex.Replace(your_String, @"[^0-9a-zA-Z]+", ",");

Excel - Sum column if condition is met by checking other column in same table

This should work, but there is a little trick. After you enter the formula, you need to hold down Ctrl+Shift while you press Enter. When you do, you'll see that the formula bar has curly-braces around your formula. This is called an array formula.

For example, if the Months are in cells A2:A100 and the amounts are in cells B2:B100, your formula would look like {=SUM(If(A2:A100="January",B2:B100))}. You don't actually type the curly-braces though.

You could also do something like =SUM((A2:A100="January")*B2:B100). You'd still need to use the trick to get it to work correctly.

How to write file in UTF-8 format?

<?php
function writeUTF8File($filename,$content) { 
        $f=fopen($filename,"w"); 
        # Now UTF-8 - Add byte order mark 
        fwrite($f, pack("CCC",0xef,0xbb,0xbf)); 
        fwrite($f,$content); 
        fclose($f); 
} 
?>

JQuery Parsing JSON array

getJSON() will also parse the JSON for you after fetching, so from then on, you are working with a simple Javascript array ([] marks an array in JSON). The documentation also has examples on how to handle the fetched data.

You can get all the values in an array using a for loop:

$.getJSON("url_with_json_here", function(data){
    for (var i = 0, len = data.length; i < len; i++) {
        console.log(data[i]);
    }
});

Check your console to see the output (Chrome, Firefox/Firebug, IE).

jQuery also provides $.each() for iterations, so you could also do this:

$.getJSON("url_with_json_here", function(data){
    $.each(data, function (index, value) {
        console.log(value);
    });
});

Why Is Subtracting These Two Times (in 1927) Giving A Strange Result?

It's a time zone change on December 31st in Shanghai.

See this page for details of 1927 in Shanghai. Basically at midnight at the end of 1927, the clocks went back 5 minutes and 52 seconds. So "1927-12-31 23:54:08" actually happened twice, and it looks like Java is parsing it as the later possible instant for that local date/time - hence the difference.

Just another episode in the often weird and wonderful world of time zones.

EDIT: Stop press! History changes...

The original question would no longer demonstrate quite the same behaviour, if rebuilt with version 2013a of TZDB. In 2013a, the result would be 358 seconds, with a transition time of 23:54:03 instead of 23:54:08.

I only noticed this because I'm collecting questions like this in Noda Time, in the form of unit tests... The test has now been changed, but it just goes to show - not even historical data is safe.

EDIT: History has changed again...

In TZDB 2014f, the time of the change has moved to 1900-12-31, and it's now a mere 343 second change (so the time between t and t+1 is 344 seconds, if you see what I mean).

EDIT: To answer a question around a transition at 1900... it looks like the Java timezone implementation treats all time zones as simply being in their standard time for any instant before the start of 1900 UTC:

import java.util.TimeZone;

public class Test {
    public static void main(String[] args) throws Exception {
        long startOf1900Utc = -2208988800000L;
        for (String id : TimeZone.getAvailableIDs()) {
            TimeZone zone = TimeZone.getTimeZone(id);
            if (zone.getRawOffset() != zone.getOffset(startOf1900Utc - 1)) {
                System.out.println(id);
            }
        }
    }
}

The code above produces no output on my Windows machine. So any time zone which has any offset other than its standard one at the start of 1900 will count that as a transition. TZDB itself has some data going back earlier than that, and doesn't rely on any idea of a "fixed" standard time (which is what getRawOffset assumes to be a valid concept) so other libraries needn't introduce this artificial transition.

How to list all the files in android phone by using adb shell?

This command will show also if the file is hidden adb shell ls -laR | grep filename

HTML Input - already filled in text

<input type="text" value="Your value">

Use the value attribute for the pre filled in values.

javax.naming.NoInitialContextException - Java

If working on EJB client library:

You need to mention the argument for getting the initial context.

InitialContext ctx = new InitialContext();

If you do not, it will look in the project folder for properties file. Also you can include the properties credentials or values in your class file itself as follows:

Properties props = new Properties();
props.put(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
props.put(Context.URL_PKG_PREFIXES, "org.jboss.ejb.client.naming");
props.put(Context.PROVIDER_URL, "jnp://localhost:1099");

InitialContext ctx = new InitialContext(props);

URL_PKG_PREFIXES: Constant that holds the name of the environment property for specifying the list of package prefixes to use when loading in URL context factories.

The EJB client library is the primary library to invoke remote EJB components.
This library can be used through the InitialContext. To invoke EJB components the library creates an EJB client context via a URL context factory. The only necessary configuration is to parse the value org.jboss.ejb.client.naming for the java.naming.factory.url.pkgs property to instantiate an InitialContext.

Get a json via Http Request in NodeJS

Just setting json option to true, the body will contain the parsed json:

request({
  url: 'http://...',
  json: true
}, function(error, response, body) {
  console.log(body);
});

What is an application binary interface (ABI)?

An application binary interface (ABI) is similar to an API, but the function is not accessible to the caller at source code level. Only a binary representation is accessible/available.

ABIs may be defined at the processor-architecture level or at the OS level. The ABIs are standards to be followed by the code-generator phase of the compiler. The standard is fixed either by the OS or by the processor.

Functionality: Define the mechanism/standard to make function calls independent of the implementation language or a specific compiler/linker/toolchain. Provide the mechanism which allows JNI, or a Python-C interface, etc.

Existing entities: Functions in machine code form.

Consumer: Another function (including one in another language, compiled by another compiler, or linked by another linker).

Where to put a textfile I want to use in eclipse?

If this is a simple project, you should be able to drag the txt file right into the project folder. Specifically, the "project folder" would be the highest level folder. I tried to do this (for a homework project that I'm doing) by putting the txt file in the src folder, but that didn't work. But finally I figured out to put it in the project file.

A good tutorial for this is http://www.vogella.com/articles/JavaIO/article.html. I used this as an intro to i/o and it helped.

Using reCAPTCHA on localhost

To your domains list of google recaptcha website add - https://www.google.com/recaptcha/admin/site/{siteid}/settings

LOCALHOST
if above doesn't work try adding 127.0.0.1 too

How to use BufferedReader in Java

Try this to read a file:

BufferedReader reader = null;

try {
    File file = new File("sample-file.dat");
    reader = new BufferedReader(new FileReader(file));

    String line;
    while ((line = reader.readLine()) != null) {
        System.out.println(line);
    }

} catch (IOException e) {
    e.printStackTrace();
} finally {
    try {
        reader.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

How to get a div to resize its height to fit container?

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
<style type="text/css">
#top, #bottom {
    height: 100px;
    width: 100%;
    position: relative;
}
#container {
    overflow: hidden;
    position: relative;
    width: 100%;
}
#container .left {
    height: 550px;
    width: 55%;
    position: relative;
    float: left;
    background-color: #3399FF;
}
#container .right {
    height: 100%;
    position: absolute;
    right: 0;
    left: 55%;
    bottom: 0px;
    top: 0px;
    background-color: #3366CC;
}
</style>
</head>

<body>
<div id="top"></div>
<div id="container">
  <div class="left"></div>
  <div class="right"></div>
</div>
<div id="bottom"></div>
</body>
</html>

Make XmlHttpRequest POST using JSON

If you use JSON properly, you can have nested object without any issue :

var xmlhttp = new XMLHttpRequest();   // new HttpRequest instance 
var theUrl = "/json-handler";
xmlhttp.open("POST", theUrl);
xmlhttp.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
xmlhttp.send(JSON.stringify({ "email": "[email protected]", "response": { "name": "Tester" } }));

Setting an environment variable before a command in Bash is not working for the second command in a pipe

How about exporting the variable, but only inside the subshell?:

(export FOO=bar && somecommand someargs | somecommand2)

Keith has a point, to unconditionally execute the commands, do this:

(export FOO=bar; somecommand someargs | somecommand2)

Setting up maven dependency for SQL Server

Download the driver JAR from the link provided by Olaf and add it to your local Maven repository with;

mvn install:install-file -Dfile=sqljdbc4.jar -DgroupId=com.microsoft.sqlserver -DartifactId=sqljdbc4 -Dversion=4.0 -Dpackaging=jar

Then add it to your project with;

<dependency>
  <groupId>com.microsoft.sqlserver</groupId>
  <artifactId>sqljdbc4</artifactId>
  <version>4.0</version>
</dependency>

Fastest way to determine if an integer's square root is an integer

Calculating square roots by Newton's method is horrendously fast ... provided that the starting value is reasonable. However there is no reasonable starting value, and in practice we end with bisection and log(2^64) behaviour.
To be really fast we need a fast way to get at a reasonable starting value, and that means we need to descend into machine language. If a processor provides an instruction like POPCNT in the Pentium, that counts the leading zeroes we can use that to have a starting value with half the significant bits. With care we can find a a fixed number of Newton steps that will always suffice. (Thus foregoing the need to loop and have very fast execution.)

A second solution is going via the floating point facility, which may have a fast sqrt calculation (like the i87 coprocessor.) Even an excursion via exp() and log() may be faster than Newton degenerated into a binary search. There is a tricky aspect to this, a processor dependant analysis of what and if refinement afterwards is necessary.

A third solution solves a slightly different problem, but is well worth mentionning because the situation is described in the question. If you want to calculate a great many square roots for numbers that differ slightly, you can use Newton iteration, if you never reinitialise the starting value, but just leave it where the previous calculation left off. I've used this with success in at least one Euler problem.

How should I multiple insert multiple records?

You should execute the command on every loop instead of building a huge command Text(btw,StringBuilder is made for this) The underlying Connection will not close and re-open for each loop, let the connection pool manager handle this. Have a look at this link for further informations: Tuning Up ADO.NET Connection Pooling in ASP.NET Applications

If you want to ensure that every command is executed successfully you can use a Transaction and Rollback if needed,