#Hiddenfield | Programs & Examples on Hiddenfield

Only on Firefox "Loading failed for the <script> with source"

If the src is https and the certificate has expired -- and even if you've made an exception -- firefox will still display this error message, and you can see the exact reason why if you look at the request under the network tab.

How to call javascript function on page load in asp.net

Place this line before the closing script tag,writing from memory:

window.onload  = GetTimeZoneOffset;

i think the question is how to call the javascript function on pageload

ASP.NET set hiddenfield a value in Javascript

First you need to create the Hidden Field properly

<asp:HiddenField ID="hdntxtbxTaksit" runat="server"></asp:HiddenField>
Then you need to set value to the hidden field

If you aren't using Jquery you should use it:

document.getElementById("<%= hdntxtbxTaksit.ClientID %>").value = "test";

If you are using Jquery, this is how it should be:

$("#<%= hdntxtbxTaksit.ClientID %>").val("test");

posting hidden value

You have to use $_POST['date'] instead of $date if it's coming from a POST request ($_GET if it's a GET request).

What causing this "Invalid length for a Base-64 char array"

This isn't an answer, sadly. After running into the intermittent error for some time and finally being annoyed enough to try to fix it, I have yet to find a fix. I have, however, determined a recipe for reproducing my problem, which might help others.

In my case it is SOLELY a localhost problem, on my dev machine that also has the app's DB. It's a .NET 2.0 app I'm editing with VS2005. The Win7 64 bit machine also has VS2008 and .NET 3.5 installed.

Here's what will generate the error, from a variety of forms:

Load a fresh copy of the form.
Enter some data, and/or postback with any of the form's controls. As long as there is no significant delay, repeat all you like, and no errors occur.
Wait a little while (1 or 2 minutes maybe, not more than 5), and try another postback.

A minute or two delay "waiting for localhost" and then "Connection was reset" by the browser, and global.asax's application error trap logs:

Application_Error event: Invalid length for a Base-64 char array.
Stack Trace:
     at System.Convert.FromBase64String(String s)
     at System.Web.UI.ObjectStateFormatter.Deserialize(String inputString)
     at System.Web.UI.Util.DeserializeWithAssert(IStateFormatter formatter, String serializedState)
     at System.Web.UI.HiddenFieldPageStatePersister.Load()

In this case, it is not the SIZE of the viewstate, but something to do with page and/or viewstate caching that seems to be biting me. Setting <pages> parameters enableEventValidation="false", and viewStateEncryption="Never" in the Web.config did not change the behavior. Neither did setting the maxPageStateFieldLength to something modest.

After submitting a POST form open a new window showing the result

Simplest working solution for flow window (tested at Chrome):

<form action='...' method=post target="result" onsubmit="window.open('','result','width=800,height=400');">
    <input name="..">
    ....
</form>

How to pass a form input value into a JavaScript function

Well ya you can do that in this way.

    <input type="text" name="address" id="address">
        <div id="map_canvas" style="width: 500px; height: 300px"></div>
    <input type="button" onclick="showAddress(address.value)" value="ShowMap"/>

Java Script

function showAddress(address){

    alert("This is address :"+address)

}

That is one example for the same. and that will run.

How can I populate a select dropdown list from a JSON feed with AngularJS?

The proper way to do it is using the ng-options directive. The HTML would look like this.

<select ng-model="selectedTestAccount" 
        ng-options="item.Id as item.Name for item in testAccounts">
    <option value="">Select Account</option>
</select>

JavaScript:

angular.module('test', []).controller('DemoCtrl', function ($scope, $http) {
    $scope.selectedTestAccount = null;
    $scope.testAccounts = [];

    $http({
            method: 'GET',
            url: '/Admin/GetTestAccounts',
            data: { applicationId: 3 }
        }).success(function (result) {
        $scope.testAccounts = result;
    });
});

You'll also need to ensure angular is run on your html and that your module is loaded.

<html ng-app="test">
    <body ng-controller="DemoCtrl">
    ....
    </body>
</html>

error: ORA-65096: invalid common user or role name in oracle

Create user dependency upon the database connect tools

sql plus
SQL> connect as sysdba;
Enter user-name: sysdba
Enter password:
Connected.
SQL> ALTER USER hr account unlock identified by hr;
User altered
 then create user on sql plus and sql developer

Remove elements from collection while iterating

Let me give a few examples with some alternatives to avoid a ConcurrentModificationException.

Suppose we have the following collection of books

List<Book> books = new ArrayList<Book>();
books.add(new Book(new ISBN("0-201-63361-2")));
books.add(new Book(new ISBN("0-201-63361-3")));
books.add(new Book(new ISBN("0-201-63361-4")));

Collect and Remove

The first technique consists in collecting all the objects that we want to delete (e.g. using an enhanced for loop) and after we finish iterating, we remove all found objects.

ISBN isbn = new ISBN("0-201-63361-2");
List<Book> found = new ArrayList<Book>();
for(Book book : books){
    if(book.getIsbn().equals(isbn)){
        found.add(book);
    }
}
books.removeAll(found);

This is supposing that the operation you want to do is "delete".

If you want to "add" this approach would also work, but I would assume you would iterate over a different collection to determine what elements you want to add to a second collection and then issue an addAll method at the end.

Using ListIterator

If you are working with lists, another technique consists in using a ListIterator which has support for removal and addition of items during the iteration itself.

ListIterator<Book> iter = books.listIterator();
while(iter.hasNext()){
    if(iter.next().getIsbn().equals(isbn)){
        iter.remove();
    }
}

Again, I used the "remove" method in the example above which is what your question seemed to imply, but you may also use its add method to add new elements during iteration.

Using JDK >= 8

For those working with Java 8 or superior versions, there are a couple of other techniques you could use to take advantage of it.

You could use the new removeIf method in the Collection base class:

ISBN other = new ISBN("0-201-63361-2");
books.removeIf(b -> b.getIsbn().equals(other));

Or use the new stream API:

ISBN other = new ISBN("0-201-63361-2");
List<Book> filtered = books.stream()
                           .filter(b -> b.getIsbn().equals(other))
                           .collect(Collectors.toList());

In this last case, to filter elements out of a collection, you reassign the original reference to the filtered collection (i.e. books = filtered) or used the filtered collection to removeAll the found elements from the original collection (i.e. books.removeAll(filtered)).

Use Sublist or Subset

There are other alternatives as well. If the list is sorted, and you want to remove consecutive elements you can create a sublist and then clear it:

books.subList(0,5).clear();

Since the sublist is backed by the original list this would be an efficient way of removing this subcollection of elements.

Something similar could be achieved with sorted sets using NavigableSet.subSet method, or any of the slicing methods offered there.

Considerations:

What method you use might depend on what you are intending to do

The collect and removeAl technique works with any Collection (Collection, List, Set, etc).
The ListIterator technique obviously only works with lists, provided that their given ListIterator implementation offers support for add and remove operations.
The Iterator approach would work with any type of collection, but it only supports remove operations.
With the ListIterator/Iterator approach the obvious advantage is not having to copy anything since we remove as we iterate. So, this is very efficient.
The JDK 8 streams example don't actually removed anything, but looked for the desired elements, and then we replaced the original collection reference with the new one, and let the old one be garbage collected. So, we iterate only once over the collection and that would be efficient.
In the collect and removeAll approach the disadvantage is that we have to iterate twice. First we iterate in the foor-loop looking for an object that matches our removal criteria, and once we have found it, we ask to remove it from the original collection, which would imply a second iteration work to look for this item in order to remove it.
I think it is worth mentioning that the remove method of the Iterator interface is marked as "optional" in Javadocs, which means that there could be Iterator implementations that throw UnsupportedOperationException if we invoke the remove method. As such, I'd say this approach is less safe than others if we cannot guarantee the iterator support for removal of elements.

Mac install and open mysql using terminal

open terminal and type

sudo sh -c 'echo /usr/local/mysql/bin > /etc/paths.d/mysql'

then close terminal and open a new terminal and type

mysql -u root -p

hit enter, and it will ask you for password

I have found this solution on https://teamtreehouse.com/community/says-mysql-command-not-found

now to set new password type

ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass';

Responsive dropdown navbar with angular-ui bootstrap (done in the correct angular kind of way)

Update 2015-06

Based on antoinepairet's comment/example:

Using uib-collapse attribute provides animations: http://plnkr.co/edit/omyoOxYnCdWJP8ANmTc6?p=preview

<nav class="navbar navbar-default" role="navigation">
    <div class="navbar-header">

        <!-- note the ng-init and ng-click here: -->
        <button type="button" class="navbar-toggle" ng-init="navCollapsed = true" ng-click="navCollapsed = !navCollapsed">
            <span class="sr-only">Toggle navigation</span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
        </button>
        <a class="navbar-brand" href="#">Brand</a>
    </div>

    <div class="collapse navbar-collapse" uib-collapse="navCollapsed">
        <ul class="nav navbar-nav">
        ...
        </ul>
    </div>
</nav>

Ancient..

I see that the question is framed around BS2, but I thought I'd pitch in with a solution for Bootstrap 3 using ng-class solution based on suggestions in ui.bootstrap issue 394:

The only variation from the official bootstrap example is the addition of ng- attributes noted by comments, below:

<nav class="navbar navbar-default" role="navigation">
  <div class="navbar-header">

    <!-- note the ng-init and ng-click here: -->
    <button type="button" class="navbar-toggle" ng-init="navCollapsed = true" ng-click="navCollapsed = !navCollapsed">
      <span class="sr-only">Toggle navigation</span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
      <span class="icon-bar"></span>
    </button>
    <a class="navbar-brand" href="#">Brand</a>
  </div>

  <!-- note the ng-class here -->
  <div class="collapse navbar-collapse" ng-class="{'in':!navCollapsed}">

    <ul class="nav navbar-nav">
    ...

Here is an updated working example: http://plnkr.co/edit/OlCCnbGlYWeO7Nxwfj5G?p=preview (hat tip Lars)

This seems to works for me in simple use cases, but you'll note in the example that the second dropdown is cut off… good luck!

Making heatmap from pandas DataFrame

If you want an interactive heatmap from a Pandas DataFrame and you are running a Jupyter notebook, you can try the interactive Widget Clustergrammer-Widget, see interactive notebook on NBViewer here, documentation here

And for larger datasets you can try the in-development Clustergrammer2 WebGL widget (example notebook here)

undefined reference to 'std::cout'

Yes, using g++ command worked for me:

g++ my_source_code.cpp

How to rsync only a specific list of files?

This answer is not the direct answer for the question. But it should help you figure out which solution fits best for your problem.

When analysing the problem you should activate the debug option -vv

Then rsync will output which files are included or excluded by which pattern:

building file list ... 
[sender] hiding file FILE1 because of pattern FILE1*
[sender] showing file FILE2 because of pattern *

How to add action listener that listens to multiple buttons

Using my approach, you can write the button click event handler in the 'classical way', just like how you did it in VB or MFC ;)

Suppose we have a class for a frame window which contains 2 buttons:

class MainWindow {
    Jbutton searchButton;
    Jbutton filterButton;
}

You can use my 'router' class to route the event back to your MainWindow class:

class MainWindow {
    JButton searchButton;
    Jbutton filterButton;
    ButtonClickRouter buttonRouter = new ButtonClickRouter(this);
    
    void initWindowContent() {
        // create your components here...
        
        // setup button listeners
        searchButton.addActionListener(buttonRouter);
        filterButton.addActionListener(buttonRouter);
    }

    void on_searchButton() {
        // TODO your handler goes here...
    }
    
    void on_filterButton() {
        // TODO your handler goes here...
    }
}

Do you like it? :)

If you like this way and hate the Java's anonymous subclass way, then you are as old as I am. The problem of 'addActionListener(new ActionListener {...})' is that it squeezes all button handlers into one outer method which makes the programme look wired. (in case you have a number of buttons in one window)

Finally, the router class is at below. You can copy it into your programme without the need for any update.

Just one thing to mention: the button fields and the event handler methods must be accessible to this router class! To simply put, if you copy this router class in the same package of your programme, your button fields and methods must be package-accessible. Otherwise, they must be public.

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class ButtonClickRouter implements ActionListener {
    private Object target;

    ButtonClickRouter(Object target) {
        this.target = target;
    }

    @Override
    public void actionPerformed(ActionEvent actionEvent) {
        // get source button
        Object sourceButton = actionEvent.getSource();

        // find the corresponding field of the button in the host class
        Field fieldOfSourceButton = null;
        for (Field field : target.getClass().getDeclaredFields()) {
            try {
                if (field.get(target).equals(sourceButton)) {
                    fieldOfSourceButton = field;
                    break;
                }
            } catch (IllegalAccessException e) {
            }
        }

        if (fieldOfSourceButton == null)
            return;

        // make the expected method name for the source button
        // rule: suppose the button field is 'searchButton', then the method
        // is expected to be 'void on_searchButton()'
        String methodName = "on_" + fieldOfSourceButton.getName();

        // find such a method
        Method expectedHanderMethod = null;
        for (Method method : target.getClass().getDeclaredMethods()) {
            if (method.getName().equals(methodName)) {
                expectedHanderMethod = method;
                break;
            }
        }

        if (expectedHanderMethod == null)
            return;

        // fire
        try {
            expectedHanderMethod.invoke(target);
        } catch (IllegalAccessException | InvocationTargetException e) { }
    }
}

I'm a beginner in Java (not in programming), so maybe there are anything inappropriate in the above code. Review it before using it, please.

Android background music service

@Synxmax's answer is correct when using a Service and the MediaPlayer class, however you also need to declare the Service in the Manifest for this to work, like so:

<service
    android:enabled="true"
    android:name="com.package.name.BackgroundSoundService" />

error: function returns address of local variable

Neither malloc or call by reference are needed. You can declare a pointer within the function and set it to the string/array you'd like to return.

Using @Gewure's code as the basis:

char *getStringNoMalloc(void){
    char string[100] = {};
    char *s_ptr = string;

    strcat(string, "bla");
    strcat(string, "/");
    strcat(string, "blub");
    //INSIDE this function "string" is OK
    printf("string : '%s'\n", string);

    return s_ptr; 
}

works perfectly.

With a non-loop version of the code in the original question:

char *foo(int x){    
    char a[1000];
    char *a_ptr = a;
    char *b = "blah";       

    strcpy(a, b);

    return a_ptr;
}

Using union and count(*) together in SQL query

select T1.name, count (*)
from (select name from Results 
      union 
      select name from Archive_Results) as T1
group by T1.name order by T1.name

Cookies vs. sessions

I will select Session, first of all session is more secure then cookies, cookies is client site data and session is server site data. Cookies is used to identify a user, because it is small pieces of code that is embedded my server with user computer browser. On the other hand Session help you to secure you identity because web server don’t know who you are because HTTP address changes the state 192.168.0.1 to 765487cf34ert8ded…..or something else numbers with the help of GET and POST methods. Session stores data of user in unique ID session that even user ID can’t match with each other. Session stores single user information in all pages of one application. Cookies expire is set with the help of setcookies() whereas session expire is not set it is expire when user turn off browsers.

import android packages cannot be resolved

May be you are using this checking :

if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
}

To resolve this you need to import android.provider.DocumentsContract class.

To resolve this issue you'll need to set the build SDK version to 19 (4.4) or higher to have API level 19 symbols available while compiling.

First, use the SDK Manager to download API 19 if you don't have it yet. Then, configure your project to use API 19:

In Android Studio: File -> Project Structure -> General Settings -> Project SDK.
In Eclipse ADT: Project Properties -> Android -> Project Build Target

I found this answer from here

Thanks .

Reset AutoIncrement in SQL Server after Delete

Several answers recommend using a statement something like this:

DBCC CHECKIDENT (mytable, RESEED, 0)

But the OP said "deleted some records", which may not be all of them, so a value of 0 is not always the right one. Another answer suggested automatically finding the maximum current value and reseeding to that one, but that runs into trouble if there are no records in the table, and thus max() will return NULL. A comment suggested using simply

DBCC CHECKIDENT (mytable)

to reset the value, but another comment correctly stated that this only increases the value to the maximum already in the table; this will not reduce the value if it is already higher than the maximum in the table, which is what the OP wanted to do.

A better solution combines these ideas. The first CHECKIDENT resets the value to 0, and the second resets it to the highest value currently in the table, in case there are records in the table:

DBCC CHECKIDENT (mytable, RESEED, 0)
DBCC CHECKIDENT (mytable)

As multiple comments have indicated, make sure there are no foreign keys in other tables pointing to the deleted records. Otherwise those foreign keys will point at records you create after reseeding the table, which is almost certainly not what you had in mind.

Removing MySQL 5.7 Completely

You need to remove the /var/lib/mysql folder. Also, purge when you remove the packages (I'm told this helps).

sudo apt-get remove --purge mysql-server mysql-client mysql-common

sudo rm -rf /var/lib/mysql

I was encountering similar issues. The second line got rid of my issues and allowed me to set up MySql from scratch. Hopefully it helps you too!

How to put img inline with text

Please make use of the code below to display images inline:

<img style='vertical-align:middle;' src='somefolder/icon.gif'>
<div style='vertical-align:middle; display:inline;'>
Your text here
</div>

How to check whether a Storage item is set?

You can use hasOwnProperty method to check this

> localStorage.setItem('foo', 123)
undefined
> localStorage.hasOwnProperty('foo')
true
> localStorage.hasOwnProperty('bar')
false

Works in current versions of Chrome(Mac), Firefox(Mac) and Safari.

Reference member variables as class members

C++ provides a good mechanism to manage the life time of an object though class/struct constructs. This is one of the best features of C++ over other languages.

When you have member variables exposed through ref or pointer it violates the encapsulation in principle. This idiom enables the consumer of the class to change the state of an object of A without it(A) having any knowledge or control of it. It also enables the consumer to hold on to a ref/pointer to A's internal state, beyond the life time of the object of A. This is bad design. Instead the class could be refactored to hold a ref/pointer to the shared object (not own it) and these could be set using the constructor (Mandate the life time rules). The shared object's class may be designed to support multithreading/concurrency as the case may apply.

Create a CSV File for a user in PHP

To have it send it as a CSV and have it give the file name, use header():

http://us2.php.net/header

header('Content-type: text/csv');
header('Content-disposition: attachment; filename="myfile.csv"');

As far as making the CSV itself, you would just loop through the result set, formatting the output and sending it, just like you would any other content.

Why am I getting error for apple-touch-icon-precomposed.png

If a user from Safari Web browser (Apple devices) visit your site. The browser tries to fetch the site icon if it is not defined in <head> in the following order:

apple-touch-icon-57x57-precomposed.png
apple-touch-icon-57x57.png
apple-touch-icon-precomposed.png
apple-touch-icon.png

To resolve this issue either define an icon for safari web browsers or apple devices. Add something like this to head section of your site:

<link rel="apple-touch-icon" href="/custom_icon.png"/>

If you want to keep <head> clean then upload the icon to root dir of your site with proper name.

The default icon size is 57px.

You can find more details on iOS developer library.

Android - android.os.NetworkOnMainThreadException

Why do 64-bit DLLs go to System32 and 32-bit DLLs to SysWoW64 on 64-bit Windows?

Ran into the same issue and researched this for a few minutes.

I was taught to use Windows 3.1 and DOS, remember those days? Shortly after I worked with Macintosh computers strictly for some time, then began to sway back to Windows after buying a x64-bit machine.

There are actual reasons behind these changes (some would say historical significance), that are necessary for programmers to continue their work.

Most of the changes are mentioned above:

Program Files vs Program Files (x86)

In the beginning the 16/86bit files were written on, '86' Intel processors.
System32 really means System64 (on 64-bit Windows)

When developers first started working with Windows7, there were several compatibility issues where other applications where stored.
SysWOW64 really means SysWOW32

Essentially, in plain english, it means 'Windows on Windows within a 64-bit machine'. Each folder is indicating where the DLLs are located for applications it they wish to use them.

Here are two links with all the basic info you need:

Hope this clears things up!

How to get the first element of an array?

Using ES6.

let arr = [22,1,4,55,7,8,9,3,2,4];

let {0 : first ,[arr.length - 1] : last} = arr;
console.log(first, last);

let {0 : first ,length : l, [l - 1] : last} = [22,1,4,55,7,8,9,3,2,4];
console.log(first, last);

Making HTML page zoom by default

A better solution is not to make your page dependable on zoom settings. If you set limits like the one you are proposing, you are limiting accessibility. If someone cannot read your text well, they just won't be able to change that. I would use proper CSS to make it look nice in any zoom.

If your really insist, take a look at this question on how to detect zoom level using JavaScript (nightmare!): How to detect page zoom level in all modern browsers?

What is a .pid file and what does it contain?

The pid files contains the process id (a number) of a given program. For example, Apache HTTPD may write its main process number to a pid file - which is a regular text file, nothing more than that - and later use the information there contained to stop itself. You can also use that information to kill the process yourself, using cat filename.pid | xargs kill

What is PAGEIOLATCH_SH wait type in SQL Server?

From Microsoft documentation:

PAGEIOLATCH_SH

Occurs when a task is waiting on a latch for a buffer that is in an I/O request. The latch request is in Shared mode. Long waits may indicate problems with the disk subsystem.

In practice, this almost always happens due to large scans over big tables. It almost never happens in queries that use indexes efficiently.

If your query is like this:

Select * from <table> where <col1> = <value> order by <PrimaryKey>

, check that you have a composite index on (col1, col_primary_key).

If you don't have one, then you'll need either a full INDEX SCAN if the PRIMARY KEY is chosen, or a SORT if an index on col1 is chosen.

Both of them are very disk I/O consuming operations on large tables.

Rails and PostgreSQL: Role postgres does not exist

This message pops up, when the database user does not exist. Compare the manual here.
Multiple local databases cannot be the explanation. Roles are valid cluster-wide. The manual again:

Note that roles are defined at the database cluster level, and so are valid in all databases in the cluster.

You must be ending up in another database-cluster. That would be another server running on the same machine, listening to a different port. Or, more likely, on a different machine.

Could it be that the message comes, in fact, from the remote server?

How to perform update operations on columns of type JSONB in Postgres 9.4

Matheus de Oliveira created handy functions for JSON CRUD operations in postgresql. They can be imported using the \i directive. Notice the jsonb fork of the functions if jsonb if your data type.

9.3 json https://gist.github.com/matheusoliveira/9488951

9.4 jsonb https://gist.github.com/inindev/2219dff96851928c2282

HTML Button : Navigate to Other Page - Different Approaches

I make a link. A link is a link. A link navigates to another page. That is what links are for and everybody understands that. So Method 3 is the only correct method in my book.

I wouldn't want my link to look like a button at all, and when I do, I still think functionality is more important than looks.

Buttons are less accessible, not only due to the need of Javascript, but also because tools for the visually impaired may not understand this Javascript enhanced button well.

Method 4 would work as well, but it is more a trick than a real functionality. You abuse a form to post 'nothing' to this other page. It's not clean.

Using if elif fi in shell scripts

sh is interpreting the && as a shell operator. Change it to -a, that’s [’s conjunction operator:

[ "$arg1" = "$arg2" -a "$arg1" != "$arg3" ]

Also, you should always quote the variables, because [ gets confused when you leave off arguments.

How do I align a number like this in C?

#include<stdio.h>
int main()
{
 int i,j,n,b;
 printf("Enter no of rows ");
 scanf("%d",&n);
 b=n;
 for(i=1;i<=n;++i)
 {
    for(j=1;j<=i;j++)
    {
        printf("%*d",b,j);
        b=1;
    }
        b=n;
    b=b-i;
    printf("\n");


 }
 return 0;
}

What is the best way to initialize a JavaScript Date to midnight?

A one-liner for object configs:

new Date(new Date().setHours(0,0,0,0));

When creating an element:

dateFieldConfig = {
      name: "mydate",
      value: new Date(new Date().setHours(0, 0, 0, 0)),
}

How to programmatically clear application data

This solution has really helped me :

By using below two methods we can clear data programatically

    public void clearApplicationData() {
    File cacheDirectory = getCacheDir();
    File applicationDirectory = new File(cacheDirectory.getParent());
    if (applicationDirectory.exists()) {
    String[] fileNames = applicationDirectory.list();
        for (String fileName : fileNames) {
            if (!fileName.equals("lib")) {
                deleteFile(new File(applicationDirectory, fileName));
            }
        }
    }
}
    public static boolean deleteFile(File file) {
    boolean deletedAll = true;
    if (file != null) {
        if (file.isDirectory()) {
            String[] children = file.list();
            for (int i = 0; i < children.length; i++) {
                deletedAll = deleteFile(new File(file, children[i])) && deletedAll;
            }
        } else {
            deletedAll = file.delete();
        }
    }

    return deletedAll;
}

How to concatenate strings in windows batch file for loop?

In batch you could do it like this:

@echo off

setlocal EnableDelayedExpansion

set "string_list=str1 str2 str3 ... str10"

for %%s in (%string_list%) do (
  set "var=%%sxyz"
  svn co "!var!"
)

If you don't need the variable !var! elsewhere in the loop, you could simplify that to

@echo off

setlocal

set "string_list=str1 str2 str3 ... str10"

for %%s in (%string_list%) do svn co "%%sxyz"

However, like C.B. I'd prefer PowerShell if at all possible:

$string_list = 'str1', 'str2', 'str3', ... 'str10'

$string_list | ForEach-Object {
  $var = "${_}xyz"   # alternatively: $var = $_ + 'xyz'
  svn co $var
}

Again, this could be simplified if you don't need $var elsewhere in the loop:

$string_list = 'str1', 'str2', 'str3', ... 'str10'
$string_list | ForEach-Object { svn co "${_}xyz" }

Declaration of Methods should be Compatible with Parent Methods in PHP

I faced this problem while trying to extend an existing class from GitHub. I'm gonna try to explain myself, first writing the class as I though it should be, and then the class as it is now.

What I though

namespace mycompany\CutreApi;

use mycompany\CutreApi\ClassOfVendor;

class CutreApi extends \vendor\AwesomeApi\AwesomeApi
{
   public function whatever(): ClassOfVendor
   {
        return new ClassOfVendor();
   }
}

What I've finally done

namespace mycompany\CutreApi;

use \vendor\AwesomeApi\ClassOfVendor;

class CutreApi extends \vendor\AwesomeApi\AwesomeApi
{
   public function whatever(): ClassOfVendor
   {
        return new \mycompany\CutreApi\ClassOfVendor();
   }
}

So seems that this errror raises also when you're using a method that return a namespaced class, and you try to return the same class but with other namespace. Fortunately I have found this solution, but I do not fully understand the benefit of this feature in php 7.2, for me it is normal to rewrite existing class methods as you need them, including the redefinition of input parameters and / or even behavior of the method.

One downside of the previous aproach, is that IDE's could not recognise the new methods implemented in \mycompany\CutreApi\ClassOfVendor(). So, for now, I will go with this implementation.

Currently done

namespace mycompany\CutreApi;

use mycompany\CutreApi\ClassOfVendor;

class CutreApi extends \vendor\AwesomeApi\AwesomeApi
{
   public function getWhatever(): ClassOfVendor
   {
        return new ClassOfVendor();
   }
}

So, instead of trying to use "whatever" method, I wrote a new one called "getWhatever". In fact both of them are doing the same, just returning a class, but with diferents namespaces as I've described before.

Hope this can help someone.

How to calculate the sentence similarity using word2vec model of gensim with python

This is actually a pretty challenging problem that you are asking. Computing sentence similarity requires building a grammatical model of the sentence, understanding equivalent structures (e.g. "he walked to the store yesterday" and "yesterday, he walked to the store"), finding similarity not just in the pronouns and verbs but also in the proper nouns, finding statistical co-occurences / relationships in lots of real textual examples, etc.

The simplest thing you could try -- though I don't know how well this would perform and it would certainly not give you the optimal results -- would be to first remove all "stop" words (words like "the", "an", etc. that don't add much meaning to the sentence) and then run word2vec on the words in both sentences, sum up the vectors in the one sentence, sum up the vectors in the other sentence, and then find the difference between the sums. By summing them up instead of doing a word-wise difference, you'll at least not be subject to word order. That being said, this will fail in lots of ways and isn't a good solution by any means (though good solutions to this problem almost always involve some amount of NLP, machine learning, and other cleverness).

So, short answer is, no, there's no easy way to do this (at least not to do it well).

How to add RSA key to authorized_keys file?

mkdir -p ~/.ssh/

To overwrite authorized_keys

cat your_key > ~/.ssh/authorized_keys

To append to the end of authorized_keys

cat your_key >> ~/.ssh/authorized_keys

301 or 302 Redirection With PHP

Best way to copy a database (SQL Server 2008)

The detach/copy/attach method will take down the database. That's not something you'd want in production.

The backup/restore will only work if you have write permissions to the production server. I work with Amazon RDS and I don't.

The import/export method doesn't really work because of foreign keys - unless you do tables one by one in the order they reference one another. You can do an import/export to a new database. That will copy all the tables and data, but not the foreign keys.

This sounds like a common operation one needs to do with database. Why isn't SQL Server handling this properly? Every time I had to do this it was frustrating.

That being said, the only painless solution I've encountered was Sql Azure Migration Tool which is maintained by the community. It works with SQL Server too.

BeanFactory not initialized or already closed - call 'refresh' before

In my case, the error "BeanFactory not initialized or already closed - call 'refresh' before" was a consequence of a previous error that I didn't noticed in the server startup. I think that it is not always the real cause of the problem.

Str_replace for multiple items

You could use preg_replace(). The following example can be run using command line php:

<?php
$s1 = "the string \\/:*?\"<>|";
$s2 = preg_replace("^[\\\\/:\*\?\"<>\|]^", " ", $s1) ;
echo "\n\$s2: \"" . $s2 . "\"\n";
?>

Output:

$s2: "the string "

Convert array of indices to 1-hot encoded numpy array

Here's a dimensionality-independent standalone solution.

This will convert any N-dimensional array arr of nonnegative integers to a one-hot N+1-dimensional array one_hot, where one_hot[i_1,...,i_N,c] = 1 means arr[i_1,...,i_N] = c. You can recover the input via np.argmax(one_hot, -1)

def expand_integer_grid(arr, n_classes):
    """

    :param arr: N dim array of size i_1, ..., i_N
    :param n_classes: C
    :returns: one-hot N+1 dim array of size i_1, ..., i_N, C
    :rtype: ndarray

    """
    one_hot = np.zeros(arr.shape + (n_classes,))
    axes_ranges = [range(arr.shape[i]) for i in range(arr.ndim)]
    flat_grids = [_.ravel() for _ in np.meshgrid(*axes_ranges, indexing='ij')]
    one_hot[flat_grids + [arr.ravel()]] = 1
    assert((one_hot.sum(-1) == 1).all())
    assert(np.allclose(np.argmax(one_hot, -1), arr))
    return one_hot

What is the best alternative IDE to Visual Studio

The other great thing about SharpDevelop is the ability to translate solutions between the two big managed .NET languages VB.NET and C#. I believe it doesn't work for "websites" but it does for web application projects.

Histogram with Logarithmic Scale and custom breaks

A histogram is a poor-man's density estimate. Note that in your call to hist() using default arguments, you get frequencies not probabilities -- add ,prob=TRUE to the call if you want probabilities.

As for the log axis problem, don't use 'x' if you do not want the x-axis transformed:

plot(mydata_hist$count, log="y", type='h', lwd=10, lend=2)

gets you bars on a log-y scale -- the look-and-feel is still a little different but can probably be tweaked.

Lastly, you can also do hist(log(x), ...) to get a histogram of the log of your data.

ASP.Net MVC – Resource Cannot be found error

How to create Select List for Country and States/province in MVC

I too liked Jordan's answer and implemented it myself. I only needed to abbreviations so in case someone else needs the same:

    public static IEnumerable<SelectListItem> GetStatesList()
    {
        IList<SelectListItem> states = new List<SelectListItem>
        {
            new SelectListItem() {Text="AL", Value="AL"},
            new SelectListItem() { Text="AK", Value="AK"},
            new SelectListItem() { Text="AZ", Value="AZ"},
            new SelectListItem() { Text="AR", Value="AR"},
            new SelectListItem() { Text="CA", Value="CA"},
            new SelectListItem() { Text="CO", Value="CO"},
            new SelectListItem() { Text="CT", Value="CT"},
            new SelectListItem() { Text="DC", Value="DC"},
            new SelectListItem() { Text="DE", Value="DE"},
            new SelectListItem() { Text="FL", Value="FL"},
            new SelectListItem() { Text="GA", Value="GA"},
            new SelectListItem() { Text="HI", Value="HI"},
            new SelectListItem() { Text="ID", Value="ID"},
            new SelectListItem() { Text="IL", Value="IL"},
            new SelectListItem() { Text="IN", Value="IN"},
            new SelectListItem() { Text="IA", Value="IA"},
            new SelectListItem() { Text="KS", Value="KS"},
            new SelectListItem() { Text="KY", Value="KY"},
            new SelectListItem() { Text="LA", Value="LA"},
            new SelectListItem() { Text="ME", Value="ME"},
            new SelectListItem() { Text="MD", Value="MD"},
            new SelectListItem() { Text="MA", Value="MA"},
            new SelectListItem() { Text="MI", Value="MI"},
            new SelectListItem() { Text="MN", Value="MN"},
            new SelectListItem() { Text="MS", Value="MS"},
            new SelectListItem() { Text="MO", Value="MO"},
            new SelectListItem() { Text="MT", Value="MT"},
            new SelectListItem() { Text="NE", Value="NE"},
            new SelectListItem() { Text="NV", Value="NV"},
            new SelectListItem() { Text="NH", Value="NH"},
            new SelectListItem() { Text="NJ", Value="NJ"},
            new SelectListItem() { Text="NM", Value="NM"},
            new SelectListItem() { Text="NY", Value="NY"},
            new SelectListItem() { Text="NC", Value="NC"},
            new SelectListItem() { Text="ND", Value="ND"},
            new SelectListItem() { Text="OH", Value="OH"},
            new SelectListItem() { Text="OK", Value="OK"},
            new SelectListItem() { Text="OR", Value="OR"},
            new SelectListItem() { Text="PA", Value="PA"},
            new SelectListItem() { Text="PR", Value="PR"},
            new SelectListItem() { Text="RI", Value="RI"},
            new SelectListItem() { Text="SC", Value="SC"},
            new SelectListItem() { Text="SD", Value="SD"},
            new SelectListItem() { Text="TN", Value="TN"},
            new SelectListItem() { Text="TX", Value="TX"},
            new SelectListItem() { Text="UT", Value="UT"},
            new SelectListItem() { Text="VT", Value="VT"},
            new SelectListItem() { Text="VA", Value="VA"},
            new SelectListItem() { Text="WA", Value="WA"},
            new SelectListItem() { Text="WV", Value="WV"},
            new SelectListItem() { Text="WI", Value="WI"},
            new SelectListItem() { Text="WY", Value="WY"}
        };
        return states;
    }

Return string Input with parse.string

As you see in an error UseCalls.java:27: error: cannot find symbol return String.parseString(input); there is no method parseString in String class. There is no need to parse it as long as JOptionPane.showInputDialog(prompt); already returns a string.

Get month name from Date

You can use one of several available Date formatters. Since this falls within the JavaScript specification, it will be available in both browser and server-side modes.

objDate.toString().split(" ")[1]; // gives short name, unsure about locale 
objDate.toLocaleDateString.split(" ")[0]; // gives long name

e.g.

js> objDate = new Date(new Date() - 9876543210)
Mon Feb 04 2013 12:37:09 GMT-0800 (PST)
js> objDate.toString().split(" ")[1]
Feb
js> objDate.toLocaleString().split(" ")[0]
February

There are more at https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date

Android Fastboot devices not returning device

For Windows:

Open device manager
Find Unknown "Android" device (likely listed under Other devices with an exclamation mark)
Update driver
Browse my computer for driver software
Let me pick from a list of devices, select List All Devices
Under "Android device" or "Google Inc", you will find "Android Bootloader Interface"
Choose "Android Bootloader Interface"
Click "yes" when it says that driver might not be compatible

What is sr-only in Bootstrap 3?

.sr-only is a class name specifically used for screen readers. You can use any class name, but .sr-only is pretty commonly used. If you don't care about developing with compliance in mind, then it can be removed. It will not affect UI in any way if removed because the CSS for this class is not visible to desktop and mobile device browsers.

There seems to be some information missing here about the use of .sr-only to explain its purpose and being for screen readers. First and foremost, it is very important to always keep impaired users in mind. Impairment is the purpose of 508 compliance: https://www.section508.gov/, and it is great that bootstrap takes this into consideration. However, the use of .sr-only is not all that needs to be taken into consideration for 508 compliance. You have the use of color, size of fonts, accessibility via navigation, descriptors, use of aria and so much more.

But as for .sr-only - what does the CSS actually do? There are several slightly different variants of the CSS used for .sr-only. One of the few I use is below:

.sr-only {
    position: absolute;
    margin: -1px 0 0 -1px;
    padding: 0;
    display: block;
    width: 1px;
    height: 1px;
    font-size: 1px;
    line-height: 1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    border: 0;
    outline: 0;
    }

The above CSS hides content in desktop and mobile browsers wrapped with this class, but is seen by a screen reader like JAWS: http://www.freedomscientific.com/Products/Blindness/JAWS. Example markup is as follows:

<a href="#" target="_blank">
    Click to Open Site
    <span class="sr-only">This is an external link</span>
</a>

Additionally, if a DOM element has a width and height of 0, the element is not seen by the DOM. This is why the above CSS uses width: 1px; height: 1px;. By using display: none and setting your CSS to height: 0 and width: 0, the element is not seen by the DOM and is thus problematic. The above CSS using width: 1px; height: 1px; is not all you do to make the content invisible to desktop and mobile browsers (without overflow: hidden, your content would still show on the screen), and visible to screen readers. Hiding the content from desktop and mobile browsers is done by adding an offset from width: 1px and height: 1px previously mentioned by using:

position: absolute;
margin: -1px 0 0 -1px; 
overflow: hidden;

Lastly, to have a very good idea of what a screen reader sees and relays to its impaired user, turn off page styling for your browser. For Firefox, you can do this by going to:

View > Page Style > No Style

I hope the information I provided here is of further use to someone in addition to the other responses.

OpenSSL: unable to verify the first certificate for Experian URL

If you are using MacOS use:

sudo cp /usr/local/etc/openssl/cert.pem /etc/ssl/certs

after this Trust anchor not found error disappears

TypeScript add Object to array with push

class PushObjects {
    testMethod(): Array<number> { 
        //declaration and initialisation of array onject
        var objs: number[] = [1,2,3,4,5,7];
        //push the elements into the array object
        objs.push(100);
        //pop the elements from the array
        objs.pop();
        return objs;
    }   
}

let pushObj = new PushObjects();
//create the button element from the dom object 
let btn = document.createElement('button');
//set the text value of the button
btn.textContent = "Click here";
//button click event
btn.onclick = function () { 

    alert(pushObj.testMethod());

} 

document.body.appendChild(btn);

Update query using Subquery in Sql Server

Here is a nice explanation of update operation with some examples. Although it is Postgres site, but the SQL queries are valid for the other DBs, too. The following examples are intuitive to understand.

-- Update contact names in an accounts table to match the currently assigned salesmen:

UPDATE accounts SET (contact_first_name, contact_last_name) =
    (SELECT first_name, last_name FROM salesmen
     WHERE salesmen.id = accounts.sales_id);

-- A similar result could be accomplished with a join:

UPDATE accounts SET contact_first_name = first_name,
                    contact_last_name = last_name
  FROM salesmen WHERE salesmen.id = accounts.sales_id;

However, the second query may give unexpected results if salesmen.id is not a unique key, whereas the first query is guaranteed to raise an error if there are multiple id matches. Also, if there is no match for a particular accounts.sales_id entry, the first query will set the corresponding name fields to NULL, whereas the second query will not update that row at all.

Hence for the given example, the most reliable query is like the following.

UPDATE tempDataView SET (marks) =
    (SELECT marks FROM tempData
     WHERE tempDataView.Name = tempData.Name);

How do I display the current value of an Android Preference in the Preference summary?

Since in androidx Preference class has the SummaryProvider interface, it can be done without OnSharedPreferenceChangeListener. Simple implementations are provided for EditTextPreference and ListPreference. Building on EddieB's answer it can look like this. Tested on androidx.preference:preference:1.1.0-alpha03.

package com.example.util.timereminder.ui.prefs;

import android.os.Bundle;

import com.example.util.timereminder.R;

import androidx.preference.EditTextPreference;
import androidx.preference.ListPreference;
import androidx.preference.Preference;
import androidx.preference.PreferenceFragmentCompat;
import androidx.preference.PreferenceGroup;

/**
 * Displays different preferences.
 */
public class PrefsFragmentExample extends PreferenceFragmentCompat {

    @Override
    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
        addPreferencesFromResource(R.xml.preferences);

        initSummary(getPreferenceScreen());
    }

    /**
     * Walks through all preferences.
     *
     * @param p The starting preference to search from.
     */
    private void initSummary(Preference p) {
        if (p instanceof PreferenceGroup) {
            PreferenceGroup pGrp = (PreferenceGroup) p;
            for (int i = 0; i < pGrp.getPreferenceCount(); i++) {
                initSummary(pGrp.getPreference(i));
            }
        } else {
            setPreferenceSummary(p);
        }
    }

    /**
     * Sets up summary providers for the preferences.
     *
     * @param p The preference to set up summary provider.
     */
    private void setPreferenceSummary(Preference p) {
        // No need to set up preference summaries for checkbox preferences because
        // they can be set up in xml using summaryOff and summary On
        if (p instanceof ListPreference) {
            p.setSummaryProvider(ListPreference.SimpleSummaryProvider.getInstance());
        } else if (p instanceof EditTextPreference) {
            p.setSummaryProvider(EditTextPreference.SimpleSummaryProvider.getInstance());
        }
    }
}

What is the use of a private static variable in Java?

What is the use of a private static class variable?

Let's say you have a library book Class. Each time you create a new Book, you want to assign it a unique id. One way is to simply start at 0 and increment the id number. But, how do all the other books know the last created id number? Simple, save it as a static variable. Do patrons need to know that the actual internal id number is for each book? No. That information is private.

public class Book {
    private static int numBooks = 0;
    private int id;
    public String name;

    Book(String name) {
        id = numBooks++;
        this.name = name;
    }
}

This is a contrived example, but I'm sure you can easily think of cases where you'd want all class instances to have access to common information that should be kept private from everyone else. Or even if you can't, it is good programming practice to make things as private as possible. What if you accidentally made that numBooks field public, even though Book users were not supposed to do anything with it. Then someone could change the number of Books without creating a new Book.

Very sneaky!

Python: download a file from an FTP server

Try using the wget library for python. You can find the documentation for it here.

import wget
link = 'ftp://example.com/foo.txt'
wget.download(link)

How to validate white spaces/empty spaces? [Angular 2]

Maybe this article can help you http://blog.angular-university.io/introduction-to-angular-2-forms-template-driven-vs-model-driven/

In this approach, you have to use FormControl then watch for value changes and then apply your mask to the value. An example should be:

...
form: FormGroup;
...


ngOnInit(){
    this.form.valueChanges
            .map((value) => {
                // Here you can manipulate your value
                value.firstName = value.firstName.trim();
                return value;
            })
            .filter((value) => this.form.valid)
            .subscribe((value) => {
               console.log("Model Driven Form valid value: vm = ",JSON.stringify(value));
            });

}

How do I convert NSMutableArray to NSArray?

you try this code---

NSMutableArray *myMutableArray = [myArray mutableCopy];

and

NSArray *myArray = [myMutableArray copy];

Change Input to Upper Case

Here we use onkeyup event in input field which triggered when the user releases a Key. And here we change our value to uppercase by toUpperCase() function.

Note that, text-transform="Uppercase" will only change the text in style. but not it's value. So,In order to change value, Use this inline code that will show as well as change the value

<input id="test-input" type="" name="" onkeyup="this.value = this.value.toUpperCase();">

Here is the code snippet that proved the value is change

_x000D_

<!DOCTYPE html>_x000D_
<html>_x000D_
<head>_x000D_
 <title></title>_x000D_
</head>_x000D_
<body>_x000D_
 <form method="get" action="">_x000D_
  <input id="test-input" type="" name="" onkeyup="this.value = this.value.toUpperCase();">_x000D_
  <input type="button" name="" value="Submit" onclick="checking()">_x000D_
 </form>_x000D_
 <script type="text/javascript">_x000D_
  function checking(argument) {_x000D_
   // body..._x000D_
   var x = document.getElementById("test-input").value_x000D_
   alert(x);_x000D_
  }_x000D_
  _x000D_
  _x000D_
 </script>_x000D_
</body>_x000D_
</html>

_x000D_

JOptionPane Input to int

Simply use:

int ans = Integer.parseInt( JOptionPane.showInputDialog(frame,
        "Text",
        JOptionPane.INFORMATION_MESSAGE,
        null,
        null,
        "[sample text to help input]"));

You cannot cast a String to an int, but you can convert it using Integer.parseInt(string).

create a text file using javascript

From a web page this cannot work since IE restricts the use of that object.

Non-static method requires a target

Normally it happens when the target is null. So better check the invoke target first then do the linq query.

Getting raw SQL query string from PDO prepared statements

You can extend PDOStatement class to capture the bounded variables and store them for later use. Then 2 methods may be added, one for variable sanitizing ( debugBindedVariables ) and another to print the query with those variables ( debugQuery ):

class DebugPDOStatement extends \PDOStatement{
  private $bound_variables=array();
  protected $pdo;

  protected function __construct($pdo) {
    $this->pdo = $pdo;
  }

  public function bindValue($parameter, $value, $data_type=\PDO::PARAM_STR){
    $this->bound_variables[$parameter] = (object) array('type'=>$data_type, 'value'=>$value);
    return parent::bindValue($parameter, $value, $data_type);
  }

  public function bindParam($parameter, &$variable, $data_type=\PDO::PARAM_STR, $length=NULL , $driver_options=NULL){
    $this->bound_variables[$parameter] = (object) array('type'=>$data_type, 'value'=>&$variable);
    return parent::bindParam($parameter, $variable, $data_type, $length, $driver_options);
  }

  public function debugBindedVariables(){
    $vars=array();

    foreach($this->bound_variables as $key=>$val){
      $vars[$key] = $val->value;

      if($vars[$key]===NULL)
        continue;

      switch($val->type){
        case \PDO::PARAM_STR: $type = 'string'; break;
        case \PDO::PARAM_BOOL: $type = 'boolean'; break;
        case \PDO::PARAM_INT: $type = 'integer'; break;
        case \PDO::PARAM_NULL: $type = 'null'; break;
        default: $type = FALSE;
      }

      if($type !== FALSE)
        settype($vars[$key], $type);
    }

    if(is_numeric(key($vars)))
      ksort($vars);

    return $vars;
  }

  public function debugQuery(){
    $queryString = $this->queryString;

    $vars=$this->debugBindedVariables();
    $params_are_numeric=is_numeric(key($vars));

    foreach($vars as $key=>&$var){
      switch(gettype($var)){
        case 'string': $var = "'{$var}'"; break;
        case 'integer': $var = "{$var}"; break;
        case 'boolean': $var = $var ? 'TRUE' : 'FALSE'; break;
        case 'NULL': $var = 'NULL';
        default:
      }
    }

    if($params_are_numeric){
      $queryString = preg_replace_callback( '/\?/', function($match) use( &$vars) { return array_shift($vars); }, $queryString);
    }else{
      $queryString = strtr($queryString, $vars);
    }

    echo $queryString.PHP_EOL;
  }
}


class DebugPDO extends \PDO{
  public function __construct($dsn, $username="", $password="", $driver_options=array()) {
    $driver_options[\PDO::ATTR_STATEMENT_CLASS] = array('DebugPDOStatement', array($this));
    $driver_options[\PDO::ATTR_PERSISTENT] = FALSE;
    parent::__construct($dsn,$username,$password, $driver_options);
  }
}

And then you can use this inherited class for debugging purpouses.

$dbh = new DebugPDO('mysql:host=localhost;dbname=test;','user','pass');

$var='user_test';
$sql=$dbh->prepare("SELECT user FROM users WHERE user = :test");
$sql->bindValue(':test', $var, PDO::PARAM_STR);
$sql->execute();

$sql->debugQuery();
print_r($sql->debugBindedVariables());

Resulting in

SELECT user FROM users WHERE user = 'user_test'

Array ( [:test] => user_test )

How to group dataframe rows into list in pandas groupby

It is time to use agg instead of apply .

When

df = pd.DataFrame( {'a':['A','A','B','B','B','C'], 'b':[1,2,5,5,4,6], 'c': [1,2,5,5,4,6]})

If you want multiple columns stack into list , result in pd.DataFrame

df.groupby('a')[['b', 'c']].agg(list)
# or 
df.groupby('a').agg(list)

If you want single column in list, result in ps.Series

df.groupby('a')['b'].agg(list)
#or
df.groupby('a')['b'].apply(list)

Note, result in pd.DataFrame is about 10x slower than result in ps.Series when you only aggregate single column, use it in multicolumns case .

$_SERVER["REMOTE_ADDR"] gives server IP rather than visitor IP

If you are using Cloudflare then this is always the Cloudflare IP address from the node which is serving you.

In this case you get the real IP address from the $_SERVER['HTTP_FORWARDED_FOR'] entry as described in the the other answers.

PowerShell script to check the status of a URL

I recently set up a script that does this.

As David Brabant pointed out, you can use the System.Net.WebRequest class to do an HTTP request.

To check whether it is operational, you should use the following example code:

# First we create the request.
$HTTP_Request = [System.Net.WebRequest]::Create('http://google.com')

# We then get a response from the site.
$HTTP_Response = $HTTP_Request.GetResponse()

# We then get the HTTP code as an integer.
$HTTP_Status = [int]$HTTP_Response.StatusCode

If ($HTTP_Status -eq 200) {
    Write-Host "Site is OK!"
}
Else {
    Write-Host "The Site may be down, please check!"
}

# Finally, we clean up the http request by closing it.
If ($HTTP_Response -eq $null) { } 
Else { $HTTP_Response.Close() }

Adding Google Play services version to your app's manifest?

This error can also happen when you've downloaded a new version of Google Play Services and not installed the latest SDK. Thats what happened to me. So, as the others mentioned, if you try to import Google Play Services and then open the console, you'll see a compile error. Try installing all the recent Android SDKs and try again, if this is the case.

Sending HTML mail using a shell script

You can use the option -o in sendEmail to send a html email.

-o message-content-type=html to specify the content type of the email.

-o message-file to add the html file to the email content.

I have tried this option in a shell scripts, and it works.

Here is the full command:

/usr/local/bin/sendEmail -f [email protected] -t "[email protected]" -s \
 smtp.test.com -u "Title" -xu [email protected] -xp password \
 -o message-charset=UTF-8  \
 -o message-content-type=html \
 -o message-file=test.html

Why are elementwise additions much faster in separate loops than in a combined loop?

I cannot replicate the results discussed here.

I don't know if poor benchmark code is to blame, or what, but the two methods are within 10% of each other on my machine using the following code, and one loop is usually just slightly faster than two - as you'd expect.

Array sizes ranged from 2^16 to 2^24, using eight loops. I was careful to initialize the source arrays so the += assignment wasn't asking the FPU to add memory garbage interpreted as a double.

I played around with various schemes, such as putting the assignment of b[j], d[j] to InitToZero[j] inside the loops, and also with using += b[j] = 1 and += d[j] = 1, and I got fairly consistent results.

As you might expect, initializing b and d inside the loop using InitToZero[j] gave the combined approach an advantage, as they were done back-to-back before the assignments to a and c, but still within 10%. Go figure.

Hardware is Dell XPS 8500 with generation 3 Core i7 @ 3.4 GHz and 8 GB memory. For 2^16 to 2^24, using eight loops, the cumulative time was 44.987 and 40.965 respectively. Visual C++ 2010, fully optimized.

PS: I changed the loops to count down to zero, and the combined method was marginally faster. Scratching my head. Note the new array sizing and loop counts.

// MemBufferMystery.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <iostream>
#include <cmath>
#include <string>
#include <time.h>

#define  dbl    double
#define  MAX_ARRAY_SZ    262145    //16777216    // AKA (2^24)
#define  STEP_SZ           1024    //   65536    // AKA (2^16)

int _tmain(int argc, _TCHAR* argv[]) {
    long i, j, ArraySz = 0,  LoopKnt = 1024;
    time_t start, Cumulative_Combined = 0, Cumulative_Separate = 0;
    dbl *a = NULL, *b = NULL, *c = NULL, *d = NULL, *InitToOnes = NULL;

    a = (dbl *)calloc( MAX_ARRAY_SZ, sizeof(dbl));
    b = (dbl *)calloc( MAX_ARRAY_SZ, sizeof(dbl));
    c = (dbl *)calloc( MAX_ARRAY_SZ, sizeof(dbl));
    d = (dbl *)calloc( MAX_ARRAY_SZ, sizeof(dbl));
    InitToOnes = (dbl *)calloc( MAX_ARRAY_SZ, sizeof(dbl));
    // Initialize array to 1.0 second.
    for(j = 0; j< MAX_ARRAY_SZ; j++) {
        InitToOnes[j] = 1.0;
    }

    // Increase size of arrays and time
    for(ArraySz = STEP_SZ; ArraySz<MAX_ARRAY_SZ; ArraySz += STEP_SZ) {
        a = (dbl *)realloc(a, ArraySz * sizeof(dbl));
        b = (dbl *)realloc(b, ArraySz * sizeof(dbl));
        c = (dbl *)realloc(c, ArraySz * sizeof(dbl));
        d = (dbl *)realloc(d, ArraySz * sizeof(dbl));
        // Outside the timing loop, initialize
        // b and d arrays to 1.0 sec for consistent += performance.
        memcpy((void *)b, (void *)InitToOnes, ArraySz * sizeof(dbl));
        memcpy((void *)d, (void *)InitToOnes, ArraySz * sizeof(dbl));

        start = clock();
        for(i = LoopKnt; i; i--) {
            for(j = ArraySz; j; j--) {
                a[j] += b[j];
                c[j] += d[j];
            }
        }
        Cumulative_Combined += (clock()-start);
        printf("\n %6i miliseconds for combined array sizes %i and %i loops",
                (int)(clock()-start), ArraySz, LoopKnt);
        start = clock();
        for(i = LoopKnt; i; i--) {
            for(j = ArraySz; j; j--) {
                a[j] += b[j];
            }
            for(j = ArraySz; j; j--) {
                c[j] += d[j];
            }
        }
        Cumulative_Separate += (clock()-start);
        printf("\n %6i miliseconds for separate array sizes %i and %i loops \n",
                (int)(clock()-start), ArraySz, LoopKnt);
    }
    printf("\n Cumulative combined array processing took %10.3f seconds",
            (dbl)(Cumulative_Combined/(dbl)CLOCKS_PER_SEC));
    printf("\n Cumulative seperate array processing took %10.3f seconds",
        (dbl)(Cumulative_Separate/(dbl)CLOCKS_PER_SEC));
    getchar();

    free(a); free(b); free(c); free(d); free(InitToOnes);
    return 0;
}

I'm not sure why it was decided that MFLOPS was a relevant metric. I though the idea was to focus on memory accesses, so I tried to minimize the amount of floating point computation time. I left in the +=, but I am not sure why.

A straight assignment with no computation would be a cleaner test of memory access time and would create a test that is uniform irrespective of the loop count. Maybe I missed something in the conversation, but it is worth thinking twice about. If the plus is left out of the assignment, the cumulative time is almost identical at 31 seconds each.

How to use hex() without 0x in Python?

Old style string formatting:

In [3]: "%02x" % 127
Out[3]: '7f'

New style

In [7]: '{:x}'.format(127)
Out[7]: '7f'

Using capital letters as format characters yields uppercase hexadecimal

In [8]: '{:X}'.format(127)
Out[8]: '7F'

Docs are here.

Creating a byte array from a stream

In case anyone likes it, here is a .NET 4+ only solution formed as an extension method without the needless Dispose call on the MemoryStream. This is a hopelessly trivial optimization, but it is worth noting that failing to Dispose a MemoryStream is not a real failure.

public static class StreamHelpers
{
    public static byte[] ReadFully(this Stream input)
    {
        var ms = new MemoryStream();
        input.CopyTo(ms);
        return ms.ToArray();
    }
}

How to delete/truncate tables from Hadoop-Hive?

You can use drop command to delete meta data and actual data from HDFS.

And just to delete data and keep the table structure, use truncate command.

For further help regarding hive ql, check language manual of hive.

Javamail Could not convert socket to TLS GMail

The first answer from @carlos worked for me:

session.getProperties().put("mail.smtp.ssl.trust", "smtp.gmail.com");

I have tested the property below and worked perfectly for me too:

session.getProperties().put("mail.smtp.starttls.enable", "true");

The two properties alone solved this type of problem, but by guarantee I used both.

How do I schedule jobs in Jenkins?

The steps for schedule jobs in Jenkins:

click on "Configure" of the job requirement
scroll down to "Build Triggers" - subtitle
Click on the checkBox of Build periodically
Add time schedule in the Schedule field, for example, @midnight

Note: under the schedule field, can see the last and the next date-time run.

Jenkins also supports predefined aliases to schedule build:

@hourly, @daily, @weekly, @monthly, @midnight

@hourly --> Build every hour at the beginning of the hour --> 0 * * * *

@daily, @midnight --> Build every day at midnight --> 0 0 * * *

@weekly --> Build every week at midnight on Sunday morning --> 0 0 * * 0

@monthly --> Build every month at midnight of the first day of the month --> 0 0 1 * *

How SID is different from Service name in Oracle tnsnames.ora

what is a SID and Service name

please look into oracle's documentation at https://docs.oracle.com/cd/B19306_01/network.102/b14212/concepts.htm

In case if the above link is not accessable in future, At the time time of writing this answer, the above link will direct you to, "Database Service and Database Instance Identification" topic in Connectivity Concepts chapter of "Database Net Services Administrator's Guide". This guide is published by oracle as part of "Oracle Database Online Documentation, 10g Release 2 (10.2)"

When I have to use one or another? Why do I need two of them?

Consider below mapping in a RAC Environment,

SID SERVICE_NAME
bob1 bob
bob2 bob
bob3 bob
bob4 bob

if load balancing is configured, the listener will 'balance' the workload across all four SIDs. Even if load balancing is configured, you can connect to bob1 all the time if you want to by using the SID instead of SERVICE_NAME.

Please refer, https://community.oracle.com/thread/4049517

Update multiple tables in SQL Server using INNER JOIN

You can't update more that one table in a single statement, however the error message you get is because of the aliases, you could try this :

BEGIN TRANSACTION

update A
set A.ORG_NAME =  @ORG_NAME
from table1 A inner join table2 B
on B.ORG_ID = A.ORG_ID
and A.ORG_ID = @ORG_ID

update B
set B.REF_NAME = @REF_NAME
from table2 B inner join table1 A
    on B.ORG_ID = A.ORG_ID
    and A.ORG_ID = @ORG_ID

COMMIT

Get the name of an object's type

Is there a JavaScript equivalent of Java's class.getName()?

No.

ES2015 Update: the name of class Foo {} is Foo.name. The name of thing's class, regardless of thing's type, is thing.constructor.name. Builtin constructors in an ES2015 environment have the correct name property; for instance (2).constructor.name is "Number".

But here are various hacks that all fall down in one way or another:

Here is a hack that will do what you need - be aware that it modifies the Object's prototype, something people frown upon (usually for good reason)

Object.prototype.getName = function() { 
   var funcNameRegex = /function (.{1,})\(/;
   var results = (funcNameRegex).exec((this).constructor.toString());
   return (results && results.length > 1) ? results[1] : "";
};

Now, all of your objects will have the function, getName(), that will return the name of the constructor as a string. I have tested this in FF3 and IE7, I can't speak for other implementations.

If you don't want to do that, here is a discussion on the various ways of determining types in JavaScript...

I recently updated this to be a bit more exhaustive, though it is hardly that. Corrections welcome...

Using the `constructor` property...

Every object has a value for its constructor property, but depending on how that object was constructed as well as what you want to do with that value, it may or may not be useful.

Generally speaking, you can use the constructor property to test the type of the object like so:

var myArray = [1,2,3];
(myArray.constructor == Array); // true

So, that works well enough for most needs. That said...

Caveats

Will not work AT ALL in many cases

This pattern, though broken, is quite common:

function Thingy() {
}
Thingy.prototype = {
    method1: function() {
    },
    method2: function() {
    }
};

Objects constructed via new Thingy will have a constructor property that points to Object, not Thingy. So we fall right at the outset; you simply cannot trust constructor in a codebase that you don't control.

Multiple Inheritance

An example where it isn't as obvious is using multiple inheritance:

function a() { this.foo = 1;}
function b() { this.bar = 2; }
b.prototype = new a(); // b inherits from a

Things now don't work as you might expect them to:

var f = new b(); // instantiate a new object with the b constructor
(f.constructor == b); // false
(f.constructor == a); // true

So, you might get unexpected results if the object your testing has a different object set as its prototype. There are ways around this outside the scope of this discussion.

There are other uses for the constructor property, some of them interesting, others not so much; for now we will not delve into those uses since it isn't relevant to this discussion.

Will not work cross-frame and cross-window

Using .constructor for type checking will break when you want to check the type of objects coming from different window objects, say that of an iframe or a popup window. This is because there's a different version of each core type constructor in each `window', i.e.

iframe.contentWindow.Array === Array // false

Using the `instanceof` operator...

The instanceof operator is a clean way of testing object type as well, but has its own potential issues, just like the constructor property.

var myArray = [1,2,3];
(myArray instanceof Array); // true
(myArray instanceof Object); // true

But instanceof fails to work for literal values (because literals are not Objects)

3 instanceof Number // false
'abc' instanceof String // false
true instanceof Boolean // false

The literals need to be wrapped in an Object in order for instanceof to work, for example

new Number(3) instanceof Number // true

The .constructor check works fine for literals because the . method invocation implicitly wraps the literals in their respective object type

3..constructor === Number // true
'abc'.constructor === String // true
true.constructor === Boolean // true

Why two dots for the 3? Because Javascript interprets the first dot as a decimal point ;)

Will not work cross-frame and cross-window

instanceof also will not work across different windows, for the same reason as the constructor property check.

Using the `name` property of the `constructor` property...

Does not work AT ALL in many cases

Again, see above; it's quite common for constructor to be utterly and completely wrong and useless.

Does NOT work in <IE9

Using myObjectInstance.constructor.name will give you a string containing the name of the constructor function used, but is subject to the caveats about the constructor property that were mentioned earlier.

For IE9 and above, you can monkey-patch in support:

if (Function.prototype.name === undefined && Object.defineProperty !== undefined) {
    Object.defineProperty(Function.prototype, 'name', {
        get: function() {
            var funcNameRegex = /function\s+([^\s(]+)\s*\(/;
            var results = (funcNameRegex).exec((this).toString());
            return (results && results.length > 1) ? results[1] : "";
        },
        set: function(value) {}
    });
}

Updated version from the article in question. This was added 3 months after the article was published, this is the recommended version to use by the article's author Matthew Scharley. This change was inspired by comments pointing out potential pitfalls in the previous code.

if (Function.prototype.name === undefined && Object.defineProperty !== undefined) {
    Object.defineProperty(Function.prototype, 'name', {
        get: function() {
            var funcNameRegex = /function\s([^(]{1,})\(/;
            var results = (funcNameRegex).exec((this).toString());
            return (results && results.length > 1) ? results[1].trim() : "";
        },
        set: function(value) {}
    });
}

Using Object.prototype.toString

It turns out, as this post details, you can use Object.prototype.toString - the low level and generic implementation of toString - to get the type for all built-in types

Object.prototype.toString.call('abc') // [object String]
Object.prototype.toString.call(/abc/) // [object RegExp]
Object.prototype.toString.call([1,2,3]) // [object Array]

One could write a short helper function such as

function type(obj){
    return Object.prototype.toString.call(obj).slice(8, -1);
}

to remove the cruft and get at just the type name

type('abc') // String

However, it will return Object for all user-defined types.

Caveats for all...

All of these are subject to one potential problem, and that is the question of how the object in question was constructed. Here are various ways of building objects and the values that the different methods of type checking will return:

// using a named function:
function Foo() { this.a = 1; }
var obj = new Foo();
(obj instanceof Object);          // true
(obj instanceof Foo);             // true
(obj.constructor == Foo);         // true
(obj.constructor.name == "Foo");  // true

// let's add some prototypical inheritance
function Bar() { this.b = 2; }
Foo.prototype = new Bar();
obj = new Foo();
(obj instanceof Object);          // true
(obj instanceof Foo);             // true
(obj.constructor == Foo);         // false
(obj.constructor.name == "Foo");  // false


// using an anonymous function:
obj = new (function() { this.a = 1; })();
(obj instanceof Object);              // true
(obj.constructor == obj.constructor); // true
(obj.constructor.name == "");         // true


// using an anonymous function assigned to a variable
var Foo = function() { this.a = 1; };
obj = new Foo();
(obj instanceof Object);      // true
(obj instanceof Foo);         // true
(obj.constructor == Foo);     // true
(obj.constructor.name == ""); // true


// using object literal syntax
obj = { foo : 1 };
(obj instanceof Object);            // true
(obj.constructor == Object);        // true
(obj.constructor.name == "Object"); // true

While not all permutations are present in this set of examples, hopefully there are enough to provide you with an idea about how messy things might get depending on your needs. Don't assume anything, if you don't understand exactly what you are after, you may end up with code breaking where you don't expect it to because of a lack of grokking the subtleties.

NOTE:

Discussion of the typeof operator may appear to be a glaring omission, but it really isn't useful in helping to identify whether an object is a given type, since it is very simplistic. Understanding where typeof is useful is important, but I don't currently feel that it is terribly relevant to this discussion. My mind is open to change though. :)

Free FTP Library

You may consider FluentFTP, previously known as System.Net.FtpClient.

It is released under The MIT License and available on NuGet (FluentFTP).

How to add a new line in textarea element?

My .replace()function using the patterns described on the other answers did not work. The pattern that worked for my case was:

var str = "Test\n\n\Test\n\Test";
str.replace(/\r\n|\r|\n/g,'&#13;&#10;');

// str: "Test&#13;&#10;&#13;&#10;Test&#13;&#10;Test"

Gradle project refresh failed after Android Studio update

Close your project, and then import project. That work for me. It's a simply way.

good luck.

Reset the graphical parameters back to default values without use of dev.off()

Could not locate Gemfile

I had the same problem and got it solved by using a different directory.

bash-4.2$ bundle install
Could not locate Gemfile
bash-4.2$ pwd
/home/amit/redmine/redmine-2.2.2-0/apps/redmine
bash-4.2$ cd htdocs/
bash-4.2$ ls
app  config db   extra  Gemfile   lib  plugins  Rakefile     script  tmp
bin  config.ru  doc  files  Gemfile.lock  log  public   README.rdoc  test    vendor
bash-4.2$ cd plugins/
bash-4.2$ bundle install
Using rake (0.9.2.2) 
Using i18n (0.6.0) 
Using multi_json (1.3.6) 
Using activesupport (3.2.11) 
Using builder (3.0.0) 
Using activemodel (3.2.11) 
Using erubis (2.7.0) 
Using journey (1.0.4) 
Using rack (1.4.1) 
Using rack-cache (1.2) 
Using rack-test (0.6.1) 
Using hike (1.2.1) 
Using tilt (1.3.3) 
Using sprockets (2.2.1) 
Using actionpack (3.2.11) 
Using mime-types (1.19) 
Using polyglot (0.3.3) 
Using treetop (1.4.10) 
Using mail (2.4.4) 
Using actionmailer (3.2.11) 
Using arel (3.0.2) 
Using tzinfo (0.3.33) 
Using activerecord (3.2.11) 
Using activeresource (3.2.11) 
Using coderay (1.0.6) 
Using rack-ssl (1.3.2) 
Using json (1.7.5) 
Using rdoc (3.12) 
Using thor (0.15.4) 
Using railties (3.2.11) 
Using jquery-rails (2.0.3) 
Using mysql2 (0.3.11) 
Using net-ldap (0.3.1) 
Using ruby-openid (2.1.8) 
Using rack-openid (1.3.1) 
Using bundler (1.2.3) 
Using rails (3.2.11) 
Using rmagick (2.13.1) 
Your bundle i

Composer Warning: openssl extension is missing. How to enable in WAMP

WAMP uses different php.ini files in the CLI and for Apache. when you enable php_openssl through the WAMP UI, you enable it for Apache, not for the CLI. You need to modify C:\wamp\bin\php\php-5.4.3\php.ini to enable it for the CLI.

Fluid or fixed grid system, in responsive design, based on Twitter Bootstrap

Fluid layout in Bootstrap 3.

Unlike Boostrap 2, Bootstrap 3 doesn't have a .container-fluid mixin to make a fluid container. The .container is a fixed width responsive grid layout. In a large screen, there are excessive white spaces in both sides of one's Web page content.

container-fluid is added back in Bootstrap 3.1

A fluid grid layout uses all screen width and works better in large screen. It turns out that it is easy to create a fluid grid layout using Bootstrap 3 mixins. The following line makes a fluid responsive grid layout:

.container-fixed;

The .container-fixed mixin sets the content to the center of the screen and add paddings. It doesn't specifies a fixed page width.

Another approach is to use Eric Flowers' CSS style

.my-fluid-container {
    padding-left: 15px;
    padding-right: 15px;
    margin-left: auto;
    margin-right: auto;
}

Remove a modified file from pull request

Removing a file from pull request but not from your local repository.

Go to your branch from where you created the request use the following commands

git checkout -- c:\temp..... next git checkout origin/master -- c:\temp... u replace origin/master with any other branch. Next git commit -m c:\temp..... Next git push origin

Note : no single quote or double quotes for the filepath

How to connect to Oracle 11g database remotely

Its quite easy on computer a you don't need to do anything just make sure both system are on same network if its not internet access(for this you need static ip). Okay now on computer b go to start menu find configuration under oracle folder click Net Configuration Assistant under that folder when window pop up click Local net configuration option it must be third option.

Now click add and click next in next screen it will ask service name here you need to add oracle global database name of computer A(Normally I use oracle86 for my installation) now click next next screen choose protocol normally its tcp click next in host name enter computer A's name you can found that in my computer properties. Click next don't change port untill you have changed that in Computer A click next and choose test connection now here you can check your connection working or not if the error is username and password not correct then click login credential button and fill correct username and password. If its saying unable to reach computer ot target not found than you must add exception in firewall for 1521 port or just disable firewall on computer A.

Zsh: Conda/Pip installs command not found

Simply copy your Anaconda bin directory and paste it at the bottom of ~/.zshrc.

For me the path is /home/theorangeguy/miniconda3/bin, so I ran:

echo ". /home/theorangeguy/miniconda3/bin" >> ~/.zshrc

This edited the ~/.zshrc. Now do:

source ~/.zshrc

It worked like a charm.

Illegal mix of collations error in MySql

You need to set 'utf8' for all parameters in each Function. It's my case:

enter image description here

Running Facebook application on localhost

Ok I'm not sure what's up with these answers but I'll let you know what worked for me as advised by a senior dev at my work. I'm working in Ruby on Rails and using Facebook's JavaScript code to get access tokens.

Problem: To do authentication, Facebook is taking the url from your address bar and comparing that with what they have on file. They don't allow you to use localhost:3000 for whatever reason. However, you can use a completely made-up domain name like yoursite.dev by running a local server and pointing yoursite.dev to 127.0.0.1:3000 or wherever your localhost was pointing to.

Step 1: Install or update Nginx

$ brew install nginx (install) or $ brew upgrade nginx (update)

Step 2: Open up your nginx config file

/usr/local/etc/nginx/nginx.conf (usually here)

/opt/boxen/config/nginx/nginx.conf(if you use Boxen)

Step 3 Add this bit of code into your http {} block

Replace proxy_pass with wherever you want to point yoursite.dev to. In my case it was replacing localhost:3000 or the equivalent 127.0.0.1:3000

server {
  listen       yoursite.dev:80;
  server_name  yoursite.dev;
  location / {
    proxy_pass http://127.0.0.1:3000;
  }
}

Step 4: Edit your hosts file, in /etc/hosts on Mac to include

127.0.0.1   yoursite.dev

This file directs domains to localhost. Nginx listens in on localhost and redirects if it matches a rule.

Step 5: Every time you use your dev environment going forward, you use the yoursite.dev in the address bar instead of localhost:3000 so Facebook logs you in correctly.

How should I escape strings in JSON?

Apache commons lang now supports this. Just make sure you have a recent enough version of Apache commons lang on your classpath. You'll need version 3.2+

Release Notes for version 3.2

LANG-797: Added escape/unescapeJson to StringEscapeUtils.

Using Eloquent ORM in Laravel to perform search of database using LIKE

You're able to do database finds using LIKE with this syntax:

Model::where('column', 'LIKE', '%value%')->get();

Get device information (such as product, model) from adb command

The correct way to do it would be:

adb -s 123abc12 shell getprop

Which will give you a list of all available properties and their values. Once you know which property you want, you can give the name as an argument to getprop to access its value directly, like this:

adb -s 123abc12 shell getprop ro.product.model

The details in adb devices -l consist of the following three properties: ro.product.name, ro.product.model and ro.product.device.

Note that ADB shell ends lines with \r\n, which depending on your platform might or might not make it more difficult to access the exact value (e.g. instead of Nexus 7 you might get Nexus 7\r).

Why is my xlabel cut off in my matplotlib plot?

for some reason sharex was set to True so I turned it back to False and it worked fine.

df.plot(........,sharex=False)

Can a foreign key be NULL and/or duplicate?

Here's an example using Oracle syntax:
First let's create a table COUNTRY

CREATE TABLE TBL_COUNTRY ( COUNTRY_ID VARCHAR2 (50) NOT NULL ) ;
ALTER TABLE TBL_COUNTRY ADD CONSTRAINT COUNTRY_PK PRIMARY KEY ( COUNTRY_ID ) ;

Create the table PROVINCE

CREATE TABLE TBL_PROVINCE(
PROVINCE_ID VARCHAR2 (50) NOT NULL ,
COUNTRY_ID  VARCHAR2 (50)
);
ALTER TABLE TBL_PROVINCE ADD CONSTRAINT PROVINCE_PK PRIMARY KEY ( PROVINCE_ID ) ;
ALTER TABLE TBL_PROVINCE ADD CONSTRAINT PROVINCE_COUNTRY_FK FOREIGN KEY ( COUNTRY_ID ) REFERENCES TBL_COUNTRY ( COUNTRY_ID ) ;

This runs perfectly fine in Oracle. Notice the COUNTRY_ID foreign key in the second table doesn't have "NOT NULL".

Now to insert a row into the PROVINCE table, it's sufficient to only specify the PROVINCE_ID. However, if you chose to specify a COUNTRY_ID as well, it must exist already in the COUNTRY table.

Creating object with dynamic keys

You can't define an object literal with a dynamic key. Do this :

var o = {};
o[key] = value;
return o;

There's no shortcut (edit: there's one now, with ES6, see the other answer).

Powershell command to hide user from exchange address lists

"WARNING: The command completed successfully but no settings of '[user id here]' have been modified."

This warning means the setting was already set like what you want it to be. So it didn't change anything for that object.

How do I make the first letter of a string uppercase in JavaScript?

This is the 2018 ECMAScript 6+ Solution:

_x000D_

const str = 'the Eiffel Tower';_x000D_
const newStr = `${str[0].toUpperCase()}${str.slice(1)}`;_x000D_
console.log('Original String:', str); // the Eiffel Tower_x000D_
console.log('New String:', newStr); // The Eiffel Tower

_x000D_

How to hide a div after some time period?

Here's a complete working example based on your testing. Compare it to what you have currently to figure out where you are going wrong.

<html> 
  <head> 
    <title>Untitled Document</title> 
    <script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script>
    <script type="text/javascript"> 
      $(document).ready( function() {
        $('#deletesuccess').delay(1000).fadeOut();
      });
    </script>
  </head> 
  <body> 
    <div id=deletesuccess > hiiiiiiiiiii </div> 
  </body> 
</html>

Visual studio - getting error "Metadata file 'XYZ' could not be found" after edit continue

Generally this kind of error comes with human mistakes like if we change the namespace in some improper way, or changing folder names from explorer for current project etc, where compiler is unable to detect sometimes.

I came across the same error, to resolve which I tried few steps. Please follow all the steps :

Clean whole Solution
Right Click on every Project in your solution , Go to Properties and make your Default namespace as well as Default assembly name same as in your code (i.e namespace before class name)
Check Folder names for each project by going through the explorer(Where your project solution is). If not matching with your project names, make it similar (Like step 2) to them.
Remove all your references from each project relevant to another of same solution, and add it again.
In Your Project Solution folder, you will find Visual c# Project file. Right click and open with Notepad. In your initial lines you would find for lines for every project like below:

Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "**Client**", "**Client** \ **Client**.csproj", "{4503E259-0E3B-414A-9074-F251684322A5}" EndProject

Check again Foldernames (I have highlighted in BOLD) and make it similar to what you did in step 2.

Clean the whole solution again
Build The Solution (If doesn't work try building individual after cleaning again)

Symfony2 : How to get form validation errors after binding the request to the form

Translated Form Error Messages (Symfony2.3)

My version of solving the problem:

/src/Acme/MyBundle/Resources/config/services.yml

services:
    form_errors:
        class: Acme\MyBundle\Form\FormErrors

/src/Acme/MyBundle/Form/FormErrors.php

<?php
namespace Acme\MyBundle\Form;

class FormErrors
{
    public function getArray(\Symfony\Component\Form\Form $form)
    {
        return $this->getErrors($form);
    }

    private function getErrors($form)
    {
        $errors = array();

        if ($form instanceof \Symfony\Component\Form\Form) {

            // ??????? ?????? ????????
            foreach ($form->getErrors() as $error) {

                $errors[] = $error->getMessage();
            }

            // ?????????? ??? ???????? ?????????
            foreach ($form->all() as $key => $child) {
                /** @var $child \Symfony\Component\Form\Form */
                if ($err = $this->getErrors($child)) {
                    $errors[$key] = $err;
                }
            }
        }

        return $errors;
    }
}

/src/Acme/MyBundle/Controller/DefaultController.php

$form = $this->createFormBuilder($entity)->getForm();
$form_errors = $this->get('form_errors')->getArray($form);
return new JsonResponse($form_errors);

In Symfony 2.5 you can get all fields errors very easy:

    $errors = array();
    foreach ($form as $fieldName => $formField) {
        foreach ($formField->getErrors(true) as $error) {
            $errors[$fieldName] = $error->getMessage();
        }
    }

How to set selected value of jquery select2?

You can use this code:

    $('#country').select2("val", "Your_value").trigger('change');

Put your desired value instead of Your_value

Hope It will work :)

How to check whether a Button is clicked by using JavaScript

if(button.clicked==true) {
    console.log("Button Clicked");
} ==> // This Code Doesn't Work Properly So Please Use Below One // 


function check() { 
    console.log("Button Clicked");
}; // This Code Works Fine // 

var button= document.querySelector("button"); // Accessing The Button // 
button.addEventListener("click", check); // Adding event to call function when clicked //

Getting the client's time zone (and offset) in JavaScript

With momentjs, you can find current timezone as

_x000D_

console.log(moment().utcOffset()); // (-240, -120, -60, 0, 60, 120, 240, etc.)

_x000D_

<script src="https://cdn.jsdelivr.net/momentjs/2.13.0/moment.min.js"></script>

_x000D_

With dayjs, you can find current timezone as

_x000D_

console.log(dayjs().utcOffset()); // (-240, -120, -60, 0, 60, 120, 240, etc.)

_x000D_

<script src="https://unpkg.com/[email protected]/dayjs.min.js"></script>

_x000D_

Both API returns utc offset in minutes.

How to change Android version and code version number?

You can manage your application versioning wisely by using the Advanced Build Version Plugin for Gradle.

You just need to include the plugin in yout build.gradle:

buildscript {
  repositories {
      jcenter()
  }

  dependencies {
      classpath 'org.moallemi.gradle.advanced-build-version:gradle-plugin:1.5.0'
  }
}

apply plugin: 'org.moallemi.advanced-build-version'

And then you can use the versioning functions (and, obviously, customize them):

advancedVersioning {
    nameOptions { }
    codeOptions { }
    outputOptions { }
}

def appVersionName = advancedVersioning.versionName
def appVersionCode = advancedVersioning.versionCode

For more information, take a look at the official documentation.

Loading PictureBox Image from resource file with path (Part 3)

The path should be something like: "Images\a.bmp". (Note the lack of a leading slash, and the slashes being back slashes.)

And then:

pictureBox1.Image = Image.FromFile(@"Images\a.bmp");

I just tried it to make sure, and it works. This is besides the other answer that you got - to "copy always".

Why has it failed to load main-class manifest attribute from a JAR file?

set the classpath and compile

javac -classpath "C:\Program Files\Java\jdk1.6.0_updateVersion\tools.jar" yourApp.java
create manifest.txt

Main-Class: yourApp newline
create yourApp.jar

jar cvf0m yourApp.jar manifest.txt yourApp.class
run yourApp.jar

java -jar yourApp.jar

What's the valid way to include an image with no src?

Use a truly blank, valid and highly compatible SVG, based on this article:

src="data:image/svg+xml;charset=utf8,%3Csvg%20xmlns='http://www.w3.org/2000/svg'%3E%3C/svg%3E"

It will default in size to 300x150px as any SVG does, but you can work with that in your img element default styles, as you would possibly need in any case in the practical implementation.

What is the difference between atomic / volatile / synchronized?

I know that two threads can not enter in Synchronize block at the same time

Two thread cannot enter a synchronized block on the same object twice. This means that two threads can enter the same block on different objects. This confusion can lead to code like this.

private Integer i = 0;

synchronized(i) {
   i++;
}

This will not behave as expected as it could be locking on a different object each time.

if this is true than How this atomic.incrementAndGet() works without Synchronize ?? and is thread safe ??

yes. It doesn't use locking to achieve thread safety.

If you want to know how they work in more detail, you can read the code for them.

And what is difference between internal reading and writing to Volatile Variable / Atomic Variable ??

Atomic class uses volatile fields. There is no difference in the field. The difference is the operations performed. The Atomic classes use CompareAndSwap or CAS operations.

i read in some article that thread has local copy of variables what is that ??

I can only assume that it referring to the fact that each CPU has its own cached view of memory which can be different from every other CPU. To ensure that your CPU has a consistent view of data, you need to use thread safety techniques.

This is only an issue when memory is shared at least one thread updates it.

Calculating Page Load Time In JavaScript

Why so complicated? When you can do:

var loadTime = window.performance.timing.domContentLoadedEventEnd- window.performance.timing.navigationStart;

If you need more times check out the window.performance object:

console.log(window.performance);

Will show you the timing object:

connectEnd                 Time when server connection is finished.
connectStart               Time just before server connection begins.
domComplete                Time just before document readiness completes.
domContentLoadedEventEnd   Time after DOMContentLoaded event completes.
domContentLoadedEventStart Time just before DOMContentLoaded starts.
domInteractive             Time just before readiness set to interactive.
domLoading                 Time just before readiness set to loading.
domainLookupEnd            Time after domain name lookup.
domainLookupStart          Time just before domain name lookup.
fetchStart                 Time when the resource starts being fetched.
loadEventEnd               Time when the load event is complete.
loadEventStart             Time just before the load event is fired.
navigationStart            Time after the previous document begins unload.
redirectCount              Number of redirects since the last non-redirect.
redirectEnd                Time after last redirect response ends.
redirectStart              Time of fetch that initiated a redirect.
requestStart               Time just before a server request.
responseEnd                Time after the end of a response or connection.
responseStart              Time just before the start of a response.
timing                     Reference to a performance timing object.
navigation                 Reference to performance navigation object.
performance                Reference to performance object for a window.
type                       Type of the last non-redirect navigation event.
unloadEventEnd             Time after the previous document is unloaded.
unloadEventStart           Time just before the unload event is fired.

Browser Support

More Info

Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]

I had this error with MySQL as my database and the only solution was reinstall all components of MySQL, because before I installed just the server.

So try to download other versions of PostgreSQL and get all the components

Rails 4: how to use $(document).ready() with turbo-links

Either use the

$(document).on "page:load", attachRatingHandler

or use jQuery's .on function to achieve the same effect

$(document).on 'click', 'span.star', attachRatingHandler

see here for more details: http://srbiv.github.io/2013/04/06/rails-4-my-first-run-in-with-turbolinks.html

How to compare if two structs, slices or maps are equal?

Here's how you'd roll your own function http://play.golang.org/p/Qgw7XuLNhb

func compare(a, b T) bool {
  if &a == &b {
    return true
  }
  if a.X != b.X || a.Y != b.Y {
    return false
  }
  if len(a.Z) != len(b.Z) || len(a.M) != len(b.M) {
    return false
  }
  for i, v := range a.Z {
    if b.Z[i] != v {
      return false
    }
  }
  for k, v := range a.M {
    if b.M[k] != v {
      return false
    }
  }
  return true
}

Cut Java String at a number of character

Use substring

String strOut = "abcdefghijklmnopqrtuvwxyz"
String result = strOut.substring(0, 8) + "...";// count start in 0 and 8 is excluded
System.out.pritnln(result);

Note: substring(int first, int second) takes two parameters. The first is inclusive and the second is exclusive.

How to use JavaScript to change div backgroundColor

<script type="text/javascript">
 function enter(elem){
     elem.style.backgroundColor = '#FF0000';
 }

 function leave(elem){
     elem.style.backgroundColor = '#FFFFFF';
 }
</script>
 <div onmouseover="enter(this)" onmouseout="leave(this)">
       Some Text
 </div>

Creating a file name as a timestamp in a batch job

I put together a little C program to print out the current timestamp (locale-safe, no bad characters...). Then, I use the FOR command to save the result in an environment variable:

:: Get the timestamp
for /f %%x in ('@timestamp') do set TIMESTAMP=%%x

:: Use it to generate a filename
for /r %%x in (.\processed\*) do move "%%~x" ".\archived\%%~nx-%TIMESTAMP%%%~xx"

Here's a link:

https://github.com/HarryPehkonen/dos-timestamp

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

for visual studio 2019 need change MSBuild path

npm config set msvs_version 2017

npm config set msbuild_path "C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\MSBuild\Current\Bin\MSBuild.exe"

npm rebuild node-sass

Javascript: Extend a Function

This is very simple and straight forward. Look at the code. Try to grasp the basic concept behind javascript extension.

First let us extend javascript function.

function Base(props) {
    const _props = props
    this.getProps = () => _props

    // We can make method private by not binding it to this object. 
    // Hence it is not exposed when we return this.
    const privateMethod = () => "do internal stuff" 

    return this
}

You can extend this function by creating child function in following way

function Child(props) {
    const parent = Base(props)
    this.getMessage = () => `Message is ${parent.getProps()}`;

    // You can remove the line below to extend as in private inheritance, 
    // not exposing parent function properties and method.
    this.prototype = parent
    return this
}

Now you can use Child function as follows,

let childObject = Child("Secret Message")
console.log(childObject.getMessage())     // logs "Message is Secret Message"
console.log(childObject.getProps())       // logs "Secret Message"

We can also create Javascript Function by extending Javascript classes, like this.

class BaseClass {
    constructor(props) {
        this.props = props
        // You can remove the line below to make getProps method private. 
        // As it will not be binded to this, but let it be
        this.getProps = this.getProps.bind(this)
    }

    getProps() {
        return this.props
    }
}

Let us extend this class with Child function like this,

function Child(props) {
    let parent = new BaseClass(props)
    const getMessage = () => `Message is ${parent.getProps()}`;
    return { ...parent, getMessage} // I have used spread operator. 
}

Again you can use Child function as follows to get similar result,

let childObject = Child("Secret Message")
console.log(childObject.getMessage())     // logs "Message is Secret Message"
console.log(childObject.getProps())       // logs "Secret Message"

Javascript is very easy language. We can do almost anything. Happy JavaScripting... Hope I was able to give you an idea to use in your case.

Free tool to Create/Edit PNG Images?

The GIMP (GNU Image Manipulation Program). It's free, open source and runs on Windows and Linux (and maybe Mac?).

Start ssh-agent on login

I solved it by adding this to the /etc/profile - system wide (or to user local .profile, or _.bash_profile_):

# SSH-AGENT 
#!/usr/bin/env bash
SERVICE='ssh-agent'
WHOAMI=`who am i |awk '{print $1}'`

if pgrep -u $WHOAMI $SERVICE >/dev/null
then
    echo $SERVICE running.
else
    echo $SERVICE not running.
    echo starting
    ssh-agent > ~/.ssh/agent_env
fi
. ~/.ssh/agent_env

This starts a new ssh-agent if not running for the current user, or re-sets the ssh-agent env parameter if running.

Scatter plot and Color mapping in Python

To add to wflynny's answer above, you can find the available colormaps here

Example:

import matplotlib.cm as cm
plt.scatter(x, y, c=t, cmap=cm.jet)

or alternatively,

plt.scatter(x, y, c=t, cmap='jet')

How do you remove a Cookie in a Java Servlet

The proper way to remove a cookie is to set the max age to 0 and add the cookie back to the HttpServletResponse object.

Most people don't realize or forget to add the cookie back onto the response object. By doing that it will expire and remove the cookie immediately.

...retrieve cookie from HttpServletRequest
cookie.setMaxAge(0);
response.addCookie(cookie);

Graph visualization library in JavaScript

JsVIS was pretty nice, but slow with larger graphs, and has been abandoned since 2007.

prefuse is a set of software tools for creating rich interactive data visualizations in Java. flare is an ActionScript library for creating visualizations that run in the Adobe Flash Player, abandoned since 2012.

Python in Xcode 4+?

This Technical Note TN2328 from Apple Developer Library helped me a lot about Changes To Embedding Python Using Xcode 5.0.

Define global variable with webpack

You can use define window.myvar = {}. When you want to use it, you can use like window.myvar = 1

How to type a new line character in SQL Server Management Studio

Either char(13) or char(10) would work. But it is recommended to use char(13) + char(10)

char(10) = \n - new line
char(13) = \r - go to the beginning of the line

How to make a new List in Java

One example:

List somelist = new ArrayList();

You can look at the javadoc for List and find all known implementing classes of the List interface that are included with the java api.

How can I see what I am about to push with git?

One way to compare your local version before pushing it on the remote repo (kind of push in dry-run):

Use TortoiseGit:
Right click on the root folder project > TortoiseGit > Diff with previous version >
for Version 2 choose refs/remotes/origin/master

How to determine if a number is odd in JavaScript

Do I have to make an array really large that has a lot of even numbers

No. Use modulus (%). It gives you the remainder of the two numbers you are dividing.

Ex. 2 % 2 = 0 because 2/2 = 1 with 0 remainder.

Ex2. 3 % 2 = 1 because 3/2 = 1 with 1 remainder.

Ex3. -7 % 2 = -1 because -7/2 = -3 with -1 remainder.

This means if you mod any number x by 2, you get either 0 or 1 or -1. 0 would mean it's even. Anything else would mean it's odd.

Import file size limit in PHPMyAdmin

How to import huge amount of Data in Xampp

It’s the best solution to open new, clean database, and import the file in phpMyAdmin. Choose file from local folder and leave all settings as is. That should be it.

But if your file exceeded file size of 2MB (that is default value in xampp installation) than you need to tweak some out. Basically we will just increase the maximum upload file size.

Open your xampp install folder and go to php folder. With some text editor file (notepad++) open the file called php.ini (by type windows describe it as configuration settings) and edit the line (cca. 770, or press ctrl+f in notepad++ to find it):

post_max_size = 2M

instead 2M, put wanted maximum file size (16MB for example but not higher than 128M),

after that go to this line: max_execution_time = 30 instead 30, increase execution time that’s in seconds (90 for example), also you need to change this line:

max_input_time = 60

instead 60, increase input time in seconds (120 for example) and top of all you have to change this line:

upload_max_filesize = 2M

instead of 2M, increase to 16M for example. Save the file, restart apache and mysql in xampp and try to upload again, if you follow correctly you should be able to import files through 16MB (example)

TypeError: 'type' object is not subscriptable when indexing in to a dictionary

Normally Python throws NameError if the variable is not defined:

>>> d[0]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'd' is not defined

However, you've managed to stumble upon a name that already exists in Python.

Because dict is the name of a built-in type in Python you are seeing what appears to be a strange error message, but in reality it is not.

The type of dict is a type. All types are objects in Python. Thus you are actually trying to index into the type object. This is why the error message says that the "'type' object is not subscriptable."

>>> type(dict)
<type 'type'>
>>> dict[0]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'type' object is not subscriptable

Note that you can blindly assign to the dict name, but you really don't want to do that. It's just going to cause you problems later.

>>> dict = {1:'a'}
>>> type(dict)
<class 'dict'>
>>> dict[1]
'a'

The true source of the problem is that you must assign variables prior to trying to use them. If you simply reorder the statements of your question, it will almost certainly work:

d = {1: "walk1.png", 2: "walk2.png", 3: "walk3.png"}
m1 = pygame.image.load(d[1])
m2 = pygame.image.load(d[2])
m3 = pygame.image.load(d[3])
playerxy = (375,130)
window.blit(m1, (playerxy))

Any way to write a Windows .bat file to kill processes?

taskkill /f /im "devenv.exe"

this will forcibly kill the pid with the exe name "devenv.exe"

equivalent to -9 on the nix'y kill command

Trying to embed newline in a variable in bash

sed solution:

echo "a b c" | sed 's/ \+/\n/g'

Result:

a
b
c

Javascript/jQuery: Set Values (Selection) in a multiple Select

Basically do a values.split(',') and then loop through the resulting array and set the Select.

Is there a sleep function in JavaScript?

function sleep(delay) {
    var start = new Date().getTime();
    while (new Date().getTime() < start + delay);
}

This code blocks for the specified duration. This is CPU hogging code. This is different from a thread blocking itself and releasing CPU cycles to be utilized by another thread. No such thing is going on here. Do not use this code, it's a very bad idea.

Are parameters in strings.xml possible?

If you need two variables in the XML, you can use:

%1$d text... %2$d or %1$s text... %2$s for string variables.

Example :

strings.xml

<string name="notyet">Website %1$s isn\'t yet available, I\'m working on it, please wait %2$s more days</string>

activity.java

String site = "site.tld";
String days = "11";

//Toast example
String notyet = getString(R.string.notyet, site, days);
Toast.makeText(getApplicationContext(), notyet, Toast.LENGTH_LONG).show();

Using colors with printf

This works for me:

printf "%b" "\e[1;34mThis is a blue text.\e[0m"

From printf(1):

%b     ARGUMENT as a string with '\' escapes interpreted, except that octal
       escapes are of the form \0 or \0NNN

Convert timestamp long to normal date format

java.time

    ZoneId usersTimeZone = ZoneId.of("Asia/Tashkent");
    Locale usersLocale = Locale.forLanguageTag("ga-IE");
    DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM)
            .withLocale(usersLocale);

    long microsSince1970 = 1_512_345_678_901_234L;
    long secondsSince1970 = TimeUnit.MICROSECONDS.toSeconds(microsSince1970);
    long remainingMicros = microsSince1970 - TimeUnit.SECONDS.toMicros(secondsSince1970);
    ZonedDateTime dateTime = Instant.ofEpochSecond(secondsSince1970, 
                    TimeUnit.MICROSECONDS.toNanos(remainingMicros))
            .atZone(usersTimeZone);
    String dateTimeInUsersFormat = dateTime.format(formatter);
    System.out.println(dateTimeInUsersFormat);

The above snippet prints:

4 Noll 2017 05:01:18

“Noll” is Gaelic for December, so this should make your user happy. Except there may be very few Gaelic speaking people living in Tashkent, so please specify the user’s correct time zone and locale yourself.

I am taking seriously that you got microseconds from your database. If second precision is fine, you can do without remainingMicros and just use the one-arg Instant.ofEpochSecond(), which will make the code a couple of lines shorter. Since Instant and ZonedDateTime do support nanosecond precision, I found it most correct to keep the full precision of your timestamp. If your timestamp was in milliseconds rather than microseconds (which they often are), you may just use Instant.ofEpochMilli().

The answers using Date, Calendar and/or SimpleDateFormat were fine when this question was asked 7 years ago. Today those classes are all long outdated, and we have so much better in java.time, the modern Java date and time API.

For most uses I recommend you use the built-in localized formats as I do in the code. You may experiment with passing SHORT, LONG or FULL for format style. Yo may even specify format style for the date and for the time of day separately using an overloaded ofLocalizedDateTime method. If a specific format is required (this was asked in a duplicate question), you can have that:

    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss, dd/MM/uuuu");

Using this formatter instead we get

05:01:18, 04/12/2017

Link: Oracle tutorial: Date Time explaining how to use java.time.

Swift GET request with parameters

Swift 3:

extension URL {
    func getQueryItemValueForKey(key: String) -> String? {
        guard let components = NSURLComponents(url: self, resolvingAgainstBaseURL: false) else {
              return nil
        }

        guard let queryItems = components.queryItems else { return nil }
     return queryItems.filter {
                 $0.name.lowercased() == key.lowercased()
                 }.first?.value
    }
}

I used it to get the image name for UIImagePickerController in func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]):

var originalFilename = ""
if let url = info[UIImagePickerControllerReferenceURL] as? URL, let imageIdentifier = url.getQueryItemValueForKey(key: "id") {
    originalFilename = imageIdentifier + ".png"
    print("file name : \(originalFilename)")
}

Return a "NULL" object if search result not found

As you have figured out that you cannot do it the way you have done in Java (or C#). Here is another suggestion, you could pass in the reference of the object as an argument and return bool value. If the result is found in your collection, you could assign it to the reference being passed and return ‘true’, otherwise return ‘false’. Please consider this code.

typedef std::map<string, Operator> OPERATORS_MAP;

bool OperatorList::tryGetOperator(string token, Operator& op)
{
    bool val = false;

    OPERATORS_MAP::iterator it = m_operators.find(token);
    if (it != m_operators.end())
    {
        op = it->second;
        val = true;
    }
    return val;
}

The function above has to find the Operator against the key 'token', if it finds the one it returns true and assign the value to parameter Operator& op.

The caller code for this routine looks like this

Operator opr;
if (OperatorList::tryGetOperator(strOperator, opr))
{
    //Do something here if true is returned.
}

The server encountered an internal error or misconfiguration and was unable to complete your request

You should look for the error in the file error_log in the log directory. Maybe there are differences between your local and server configuration (db user/password etc.etc.)

usually the log file is in

/var/log/apache2/error.log

/var/log/httpd/error.log

How to get user agent in PHP

You could also use the php native funcion get_browser()

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

What's the Linq to SQL equivalent to TOP or LIMIT/OFFSET?

@Janei: my first comment here is about your sample ;)

I think if you do like this, you want to take 4, then applying the sort on these 4.

var dados =  from d in dc.tbl_News.Take(4) 
                orderby d.idNews descending
                select new 
                {
                    d.idNews,
                    d.titleNews,
                    d.textNews,
                    d.dateNews,
                    d.imgNewsThumb
                };

Different than sorting whole tbl_News by idNews descending and then taking 4

var dados =  (from d in dc.tbl_News
                orderby d.idNews descending
                select new 
                {
                    d.idNews,
                    d.titleNews,
                    d.textNews,
                    d.dateNews,
                    d.imgNewsThumb
                }).Take(4);

no ? results may be different.

android: how to use getApplication and getApplicationContext from non activity / service class

The getApplication() method is located in the Activity class, that's why you can't access it from your helper class.

If you really need to access your application context from your helper, you should hold a reference to the activity's context and pass it on invocation to the helper.

Volatile Vs Atomic

Volatile and Atomic are two different concepts. Volatile ensures, that a certain, expected (memory) state is true across different threads, while Atomics ensure that operation on variables are performed atomically.

Take the following example of two threads in Java:

Thread A:

value = 1;
done = true;

Thread B:

if (done)
  System.out.println(value);

Starting with value = 0 and done = false the rule of threading tells us, that it is undefined whether or not Thread B will print value. Furthermore value is undefined at that point as well! To explain this you need to know a bit about Java memory management (which can be complex), in short: Threads may create local copies of variables, and the JVM can reorder code to optimize it, therefore there is no guarantee that the above code is run in exactly that order. Setting done to true and then setting value to 1 could be a possible outcome of the JIT optimizations.

volatile only ensures, that at the moment of access of such a variable, the new value will be immediately visible to all other threads and the order of execution ensures, that the code is at the state you would expect it to be. So in case of the code above, defining done as volatile will ensure that whenever Thread B checks the variable, it is either false, or true, and if it is true, then value has been set to 1 as well.

As a side-effect of volatile, the value of such a variable is set thread-wide atomically (at a very minor cost of execution speed). This is however only important on 32-bit systems that i.E. use long (64-bit) variables (or similar), in most other cases setting/reading a variable is atomic anyways. But there is an important difference between an atomic access and an atomic operation. Volatile only ensures that the access is atomically, while Atomics ensure that the operation is atomically.

Take the following example:

i = i + 1;

No matter how you define i, a different Thread reading the value just when the above line is executed might get i, or i + 1, because the operation is not atomically. If the other thread sets i to a different value, in worst case i could be set back to whatever it was before by thread A, because it was just in the middle of calculating i + 1 based on the old value, and then set i again to that old value + 1. Explanation:

Assume i = 0
Thread A reads i, calculates i+1, which is 1
Thread B sets i to 1000 and returns
Thread A now sets i to the result of the operation, which is i = 1

Atomics like AtomicInteger ensure, that such operations happen atomically. So the above issue cannot happen, i would either be 1000 or 1001 once both threads are finished.

How to compare strings in an "if" statement?

You can't compare array of characters using == operator. You have to use string compare functions. Take a look at Strings (c-faq).

The standard library's strcmp function compares two strings, and returns 0 if they are identical, or a negative number if the first string is alphabetically "less than" the second string, or a positive number if the first string is "greater."

How do I connect to a MySQL Database in Python?

Oracle (MySQL) now supports a pure Python connector. That means no binaries to install: it's just a Python library. It's called "Connector/Python".

http://dev.mysql.com/downloads/connector/python/

Difference between `constexpr` and `const`

const applies for variables, and prevents them from being modified in your code.

constexpr tells the compiler that this expression results in a compile time constant value, so it can be used in places like array lengths, assigning to const variables, etc. The link given by Oli has a lot of excellent examples.

Basically they are 2 different concepts altogether, and can (and should) be used together.

How to install a specific version of Node on Ubuntu?

yes, its a duplicate answer but I insist using n module to install a specific version(following commands installs node version 6.9.5).

npm install -g  n
n 6.9.5

How to run the Python program forever?

sleep is a good way to avoid overload on the cpu

not sure if it's really clever, but I usually use

while(not sleep(5)):
    #code to execute

sleep method always returns None.

How to get the anchor from the URL using jQuery?

Use

window.location.hash

to retrieve everything beyond and including the #

I do not want to inherit the child opacity from the parent in CSS

If you have to use an image as the transparent background, you might be able to work around it using a pseudo element:

html

<div class="wrap"> 
   <p>I have 100% opacity</p>  
</div>

css

.wrap, .wrap > * {
  position: relative;
}
.wrap:before {
  content: " ";
  opacity: 0.2;
  background: url("http://placehold.it/100x100/FF0000") repeat;     
  position: absolute;
  width: 100%;
  height: 100%;
}

How to escape special characters in building a JSON string?

Everyone is talking about how to escape ' in a '-quoted string literal. There's a much bigger issue here: single-quoted string literals aren't valid JSON. JSON is based on JavaScript, but it's not the same thing. If you're writing an object literal inside JavaScript code, fine; if you actually need JSON, you need to use ".

With double-quoted strings, you won't need to escape the '. (And if you did want a literal " in the string, you'd use \".)

Aligning rotated xticklabels with their respective xticks

An easy, loop-free alternative is to use the horizontalalignment Text property as a keyword argument to xticks[1]. In the below, at the commented line, I've forced the xticks alignment to be "right".

n=5
x = np.arange(n)
y = np.sin(np.linspace(-3,3,n))
xlabels = ['Long ticklabel %i' % i for i in range(n)]
fig, ax = plt.subplots()
ax.plot(x,y, 'o-')

plt.xticks(
        [0,1,2,3,4],
        ["this label extends way past the figure's left boundary",
        "bad motorfinger", "green", "in the age of octopus diplomacy", "x"], 
        rotation=45,
        horizontalalignment="right")    # here
plt.show()

(yticks already aligns the right edge with the tick by default, but for xticks the default appears to be "center".)

[1] You find that described in the xticks documentation if you search for the phrase "Text properties".

window.onunload is not working properly in Chrome browser. Can any one help me?

Please try window.onbeforeunload instead for window.onunload for chrome. You can also try calling onbeforeunload from the body> tag which might work in chrome.

However, we do have a problem with unload function in chrome browser. please check

location.href does not work in chrome when called through the body/window unload event

Write output to a text file in PowerShell

Use the Out-File cmdlet

 Compare-Object ... | Out-File C:\filename.txt

Optionally, add -Encoding utf8 to Out-File as the default encoding is not really ideal for many uses.

Excel telling me my blank cells aren't blank

'Select non blank cells
Selection.SpecialCells(xlCellTypeConstants, 23).Select
' REplace tehse blank look like cells to something uniqu
Selection.Replace What:="", Replacement:="TOBEDELETED", LookAt:=xlWhole, _
    SearchOrder:=xlByRows, MatchCase:=False, SearchFormat:=False, _
    ReplaceFormat:=False
'now replace this uique text to nothing and voila all will disappear
Selection.Replace What:="TOBEDELETED", Replacement:="", LookAt:=xlWhole, _
    SearchOrder:=xlByRows, MatchCase:=False, SearchFormat:=False, _
    ReplaceFormat:=False

Calling C/C++ from Python?

You should have a look at Boost.Python. Here is the short introduction taken from their website:

The Boost Python Library is a framework for interfacing Python and C++. It allows you to quickly and seamlessly expose C++ classes functions and objects to Python, and vice-versa, using no special tools -- just your C++ compiler. It is designed to wrap C++ interfaces non-intrusively, so that you should not have to change the C++ code at all in order to wrap it, making Boost.Python ideal for exposing 3rd-party libraries to Python. The library's use of advanced metaprogramming techniques simplifies its syntax for users, so that wrapping code takes on the look of a kind of declarative interface definition language (IDL).

How do I create a new Git branch from an old commit?

git checkout -b NEW_BRANCH_NAME COMMIT_ID

This will create a new branch called 'NEW_BRANCH_NAME' and check it out.

("check out" means "to switch to the branch")

git branch NEW_BRANCH_NAME COMMIT_ID

This just creates the new branch without checking it out.

in the comments many people seem to prefer doing this in two steps. here's how to do so in two steps:

git checkout COMMIT_ID
# you are now in the "detached head" state
git checkout -b NEW_BRANCH_NAME

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

C does not really have multi-dimensional arrays, but there are several ways to simulate them. The way to pass such arrays to a function depends on the way used to simulate the multiple dimensions:

1) Use an array of arrays. This can only be used if your array bounds are fully determined at compile time, or if your compiler supports VLA's:

#define ROWS 4
#define COLS 5

void func(int array[ROWS][COLS])
{
  int i, j;

  for (i=0; i<ROWS; i++)
  {
    for (j=0; j<COLS; j++)
    {
      array[i][j] = i*j;
    }
  }
}

void func_vla(int rows, int cols, int array[rows][cols])
{
  int i, j;

  for (i=0; i<rows; i++)
  {
    for (j=0; j<cols; j++)
    {
      array[i][j] = i*j;
    }
  }
}

int main()
{
  int x[ROWS][COLS];

  func(x);
  func_vla(ROWS, COLS, x);
}

2) Use a (dynamically allocated) array of pointers to (dynamically allocated) arrays. This is used mostly when the array bounds are not known until runtime.

void func(int** array, int rows, int cols)
{
  int i, j;

  for (i=0; i<rows; i++)
  {
    for (j=0; j<cols; j++)
    {
      array[i][j] = i*j;
    }
  }
}

int main()
{
  int rows, cols, i;
  int **x;

  /* obtain values for rows & cols */

  /* allocate the array */
  x = malloc(rows * sizeof *x);
  for (i=0; i<rows; i++)
  {
    x[i] = malloc(cols * sizeof *x[i]);
  }

  /* use the array */
  func(x, rows, cols);

  /* deallocate the array */
  for (i=0; i<rows; i++)
  {
    free(x[i]);
  }
  free(x);
}

3) Use a 1-dimensional array and fixup the indices. This can be used with both statically allocated (fixed-size) and dynamically allocated arrays:

void func(int* array, int rows, int cols)
{
  int i, j;

  for (i=0; i<rows; i++)
  {
    for (j=0; j<cols; j++)
    {
      array[i*cols+j]=i*j;
    }
  }
}

int main()
{
  int rows, cols;
  int *x;

  /* obtain values for rows & cols */

  /* allocate the array */
  x = malloc(rows * cols * sizeof *x);

  /* use the array */
  func(x, rows, cols);

  /* deallocate the array */
  free(x);
}

4) Use a dynamically allocated VLA. One advantage of this over option 2 is that there is a single memory allocation; another is that less memory is needed because the array of pointers is not required.

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

extern void func_vla(int rows, int cols, int array[rows][cols]);
extern void get_rows_cols(int *rows, int *cols);
extern void dump_array(const char *tag, int rows, int cols, int array[rows][cols]);

void func_vla(int rows, int cols, int array[rows][cols])
{
    for (int i = 0; i < rows; i++)
    {
        for (int j = 0; j < cols; j++)
        {
            array[i][j] = (i + 1) * (j + 1);
        }
    }
}

int main(void)
{
    int rows, cols;

    get_rows_cols(&rows, &cols);

    int (*array)[cols] = malloc(rows * cols * sizeof(array[0][0]));
    /* error check omitted */

    func_vla(rows, cols, array);
    dump_array("After initialization", rows, cols, array);

    free(array);
    return 0;
}

void dump_array(const char *tag, int rows, int cols, int array[rows][cols])
{
    printf("%s (%dx%d):\n", tag, rows, cols);
    for (int i = 0; i < rows; i++)
    {
        for (int j = 0; j < cols; j++)
            printf("%4d", array[i][j]);
        putchar('\n');
    }
}

void get_rows_cols(int *rows, int *cols)
{
    srand(time(0));           // Only acceptable because it is called once
    *rows = 5 + rand() % 10;
    *cols = 3 + rand() % 12;
}

(See srand() — why call it only once?.)

How is CountDownLatch used in Java Multithreading?

From oracle documentation about CountDownLatch:

A synchronization aid that allows one or more threads to wait until a set of operations being performed in other threads completes.

A CountDownLatch is initialized with a given count. The await methods block until the current count reaches zero due to invocations of the countDown() method, after which all waiting threads are released and any subsequent invocations of await return immediately. This is a one-shot phenomenon -- the count cannot be reset.

A CountDownLatch is a versatile synchronization tool and can be used for a number of purposes.

A CountDownLatch initialized with a count of one serves as a simple on/off latch, or gate: all threads invoking await wait at the gate until it is opened by a thread invoking countDown().

A CountDownLatch initialized to N can be used to make one thread wait until N threads have completed some action, or some action has been completed N times.

public void await()
           throws InterruptedException

Causes the current thread to wait until the latch has counted down to zero, unless the thread is interrupted.

If the current count is zero then this method returns immediately.

public void countDown()

Decrements the count of the latch, releasing all waiting threads if the count reaches zero.

If the current count is greater than zero then it is decremented. If the new count is zero then all waiting threads are re-enabled for thread scheduling purposes.

Explanation of your example.

You have set count as 3 for latch variable

CountDownLatch latch = new CountDownLatch(3);

You have passed this shared latch to Worker thread : Processor
Three Runnable instances of Processor have been submitted to ExecutorService executor
Main thread ( App ) is waiting for count to become zero with below statement
```
 latch.await();  
```
Processor thread sleeps for 3 seconds and then it decrements count value with latch.countDown()
First Process instance will change latch count as 2 after it's completion due to latch.countDown().
Second Process instance will change latch count as 1 after it's completion due to latch.countDown().
Third Process instance will change latch count as 0 after it's completion due to latch.countDown().
Zero count on latch causes main thread App to come out from await
App program prints this output now : Completed

PHP how to get the base domain/url?

Use SERVER_NAME.

echo $_SERVER['SERVER_NAME']; //Outputs www.example.com

How to add to an NSDictionary

You want to ask is "what is the difference between a mutable and a non-mutable array or dictionary." Many times there different terms are used to describe things that you already know about. In this case, you can replace the term "mutable" with "dynamic." So, a mutuable dictionary or array is one that is "dynamic" and can change at runtime, whereas a non-mutable dictionary or array is one that is "static" and defined in your code and does not change at runtime (in other words, you will not be adding, deleting or possibly sorting the elements.)

As to how it is done, you are asking us to repeat the documentation here. All you need to do is to search in sample code and the Xcode documentation to see exactly how it is done. But the mutable thing threw me too when I was first learning, so I'll give you that one!

How to Identify Microsoft Edge browser via CSS?

/* Microsoft Edge Browser 12-18 (All versions before Chromium) */

This one should work:

@supports (-ms-ime-align:auto) {
    .selector {
        property: value;
    }
}

For more see: Browser Strangeness

Prevent browser caching of AJAX call result

If you are using .net ASP MVC, disable the caching on the controller action by adding the following attribute on the end point function:

[OutputCacheAttribute(VaryByParam = "*", Duration = 0, NoStore = true)]

Is it possible to run CUDA on AMD GPUs?

Nope, you can't use CUDA for that. CUDA is limited to NVIDIA hardware. OpenCL would be the best alternative.

Khronos itself has a list of resources. As does the StreamComputing.eu website. For your AMD specific resources, you might want to have a look at AMD's APP SDK page.

Note that at this time there are several initiatives to translate/cross-compile CUDA to different languages and APIs. One such an example is HIP. Note however that this still does not mean that CUDA runs on AMD GPUs.

How to get all the values of input array element jquery

By Using map

var values = $("input[name='pname[]']")
              .map(function(){return $(this).val();}).get();

Adding an onclick function to go to url in JavaScript?

function URL() {
    location.href = 'http://your.url.here';
}

SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax — PHP — PDO

Same pdo error in sql query while trying to insert into database value from multidimential array:

$sql = "UPDATE test SET field=arr[$s][a] WHERE id = $id";
$sth = $db->prepare($sql);    
$sth->execute();

Extracting array arr[$s][a] from sql query, using instead variable containing it fixes the problem.

How to save picture to iPhone photo library?

You can use this

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
   UIImageWriteToSavedPhotosAlbum(img.image, nil, nil, nil);
});

What is the iPad user agent?

From Simulator 3.2 final:

Mozilla/5.0 (iPad; U; CPU OS 3_2 like Mac OS X; en-us) AppleWebKit/531.21.10 (KHTML, like Gecko) Version/4.0.4 Mobile/7B367 Safari/531.21.10

What's NSLocalizedString equivalent in Swift?

When you are developing an SDK. You need some extra operation.

1) create Localizable.strings as usual in YourLocalizeDemoSDK.

2) create the same Localizable.strings in YourLocalizeDemo.

3) find your Bundle Path of YourLocalizeDemoSDK.

Swift4:

// if you use NSLocalizeString in NSObject, you can use it like this
let value = NSLocalizedString("key", tableName: nil, bundle: Bundle(for: type(of: self)), value: "", comment: "")

Bundle(for: type(of: self)) helps you to find the bundle in YourLocalizeDemoSDK. If you use Bundle.main instead, you will get a wrong value(in fact it will be the same string with the key).

But if you want to use the String extension mentioned by dr OX. You need to do some more. The origin extension looks like this.

extension String {
    var localized: String {
        return NSLocalizedString(self, tableName: nil, bundle: Bundle.main, value: "", comment: "")
    }
}

As we know, we are developing an SDK, Bundle.main will get the bundle of YourLocalizeDemo's bundle. That's not what we want. We need the bundle in YourLocalizeDemoSDK. This is a trick to find it quickly.

Run the code below in a NSObject instance in YourLocalizeDemoSDK. And you will get the URL of YourLocalizeDemoSDK.

let bundleURLOfSDK = Bundle(for: type(of: self)).bundleURL
let mainBundleURL = Bundle.main.bundleURL

Print both of the two url, you will find that we can build bundleURLofSDK base on mainBundleURL. In this case, it will be:

let bundle = Bundle(url: Bundle.main.bundleURL.appendingPathComponent("Frameworks").appendingPathComponent("YourLocalizeDemoSDK.framework")) ?? Bundle.main

And the String extension will be:

extension String {
    var localized: String {
        let bundle = Bundle(url: Bundle.main.bundleURL.appendingPathComponent("Frameworks").appendingPathComponent("YourLocalizeDemoSDK.framework")) ?? Bundle.main
        return NSLocalizedString(self, tableName: nil, bundle: bundle, value: "", comment: "")
    }
}

Hope it helps.

Change the mouse pointer using JavaScript

document.body.style.cursor = 'cursorurl';

How to save the contents of a div as a image?

There are several of this same question (1, 2). One way of doing it is using canvas. Here's a working solution. Here you can see some working examples of using this library.

Position a CSS background image x pixels from the right?

Image workaround with transparent pixels on the right to serve as right margin.

The image workaround for the same is to create a PNG or GIF image (image file formats that support transparency) which has a transparent portion on the right of the image exactly equal to the number of pixels that you want to give a right margin of (eg: 5px, 10px, etc.)

This works well consistently across fixed widths as well as widths in percentages. Practically a good solution for accordion headers having a plus/minus or up/down arrow image on the header's right!

Downside: Unfortunately, you cannot use JPG unless the background portion of the container and the background color of the CSS background image are of the same flat color (with out a gradient/vignette), mostly white/black etc.

Changing file extension in Python

As AnaPana mentioned pathlib is more new and easier in python 3.4 and there is new with_suffix method that can handle this problem easily:

from pathlib import Path
new_filename = Path(mysequence.fasta).with_suffix('.aln')

Use a URL to link to a Google map with a marker on it

This URL format worked like a charm:

http://maps.google.com/maps?&z={INSERT_MAP_ZOOM}&mrt={INSERT_TYPE_OF_SEARCH}&t={INSERT_MAP_TYPE}&q={INSERT_MAP_LAT_COORDINATES}+{INSERT_MAP_LONG_COORDINATES}

Example for Mount Everest:

http://maps.google.com/maps?&z=15&mrt=yp&t=k&q=27.9879012+86.9253141

Preview

Full reference here:

https://moz.com/ugc/everything-you-never-wanted-to-know-about-google-maps-parameters

-- EDIT --

Apparently the zoom parameter stopped working, here's the updated format.

Format

https://www.google.com/maps/@?api=1&map_action=map&basemap=satellite&center={LAT},{LONG}&zoom={ZOOM}

Example

https://www.google.com/maps/@?api=1&map_action=map&basemap=satellite&center=27.9879012,86.9253141&zoom=14

Angularjs Template Default Value if Binding Null / Undefined (With Filter)

I made the following filter:

angular.module('app').filter('ifEmpty', function() {
    return function(input, defaultValue) {
        if (angular.isUndefined(input) || input === null || input === '') {
            return defaultValue;
        }

        return input;
    }
});

To be used like this:

<span>{{aPrice | currency | ifEmpty:'N/A'}}</span>
<span>{{aNum | number:3 | ifEmpty:0}}</span>

java.security.AccessControlException: Access denied (java.io.FilePermission

Although it is not recommended, but if you really want to let your web application access a folder outside its deployment directory. You need to add following permission in java.policy file (path is as in the reply of Petey B)

permission java.io.FilePermission "your folder path", "write"

In your case it would be

permission java.io.FilePermission "S:/PDSPopulatingProgram/-", "write"

Here /- means any files or sub-folders inside this folder.

Warning: But by doing this, you are inviting some security risk.

Is Ruby pass by reference or by value?

In traditional terminology, Ruby is strictly pass-by-value. But that's not really what you're asking here.

Ruby doesn't have any concept of a pure, non-reference value, so you certainly can't pass one to a method. Variables are always references to objects. In order to get an object that won't change out from under you, you need to dup or clone the object you're passed, thus giving an object that nobody else has a reference to. (Even this isn't bulletproof, though — both of the standard cloning methods do a shallow copy, so the instance variables of the clone still point to the same objects that the originals did. If the objects referenced by the ivars mutate, that will still show up in the copy, since it's referencing the same objects.)

Base64 Encoding Image

As far as I remember there is an xml element for the image data. You can use this website to encode a file (use the upload field). Then just copy and paste the data to the XML element.

You could also use PHP to do this like so:

 <?php
        $im = file_get_contents('filename.gif');
        $imdata = base64_encode($im);      
?>

Use Mozilla's guide for help on creating OpenSearch plugins. For example, the icon element is used like this:

<img width="16" height="16">data:image/x-icon;base64,imageData</>

Where imageData is your base64 data.

The model item passed into the dictionary is of type .. but this dictionary requires a model item of type

The error means that you're navigating to a view whose model is declared as typeof Foo (by using @model Foo), but you actually passed it a model which is typeof Bar (note the term dictionary is used because a model is passed to the view via a ViewDataDictionary).

The error can be caused by

Passing the wrong model from a controller method to a view (or partial view)

Common examples include using a query that creates an anonymous object (or collection of anonymous objects) and passing it to the view

var model = db.Foos.Select(x => new
{
    ID = x.ID,
    Name = x.Name
};
return View(model); // passes an anonymous object to a view declared with @model Foo

or passing a collection of objects to a view that expect a single object

var model = db.Foos.Where(x => x.ID == id);
return View(model); // passes IEnumerable<Foo> to a view declared with @model Foo

The error can be easily identified at compile time by explicitly declaring the model type in the controller to match the model in the view rather than using var.

Passing the wrong model from a view to a partial view

Given the following model

public class Foo
{
    public Bar MyBar { get; set; }
}

and a main view declared with @model Foo and a partial view declared with @model Bar, then

Foo model = db.Foos.Where(x => x.ID == id).Include(x => x.Bar).FirstOrDefault();
return View(model);

will return the correct model to the main view. However the exception will be thrown if the view includes

@Html.Partial("_Bar") // or @{ Html.RenderPartial("_Bar"); }

By default, the model passed to the partial view is the model declared in the main view and you need to use

@Html.Partial("_Bar", Model.MyBar) // or @{ Html.RenderPartial("_Bar", Model.MyBar); }

to pass the instance of Bar to the partial view. Note also that if the value of MyBar is null (has not been initialized), then by default Foo will be passed to the partial, in which case, it needs to be

@Html.Partial("_Bar", new Bar())

Declaring a model in a layout

If a layout file includes a model declaration, then all views that use that layout must declare the same model, or a model that derives from that model.

If you want to include the html for a separate model in a Layout, then in the Layout, use @Html.Action(...) to call a [ChildActionOnly] method initializes that model and returns a partial view for it.

Add key value pair to all objects in array

Simply use map function:

var arrOfObj = arrOfObj.map(function(element){
   element.active = true;
   return element;
}

Map is pretty decent on compatibility: you can be reasonably safe from IE <= 9.

However, if you are 100% sure your users will use ES6 Compatible browser, you can shorten that function with arrow functions, as @Sergey Panfilov has suggested.

error: Libtool library used but 'LIBTOOL' is undefined

A good answer for me was to install libtool:

sudo apt-get install libtool

Use sed to replace all backslashes with forward slashes

$ echo "C:\Windows\Folder\File.txt" | sed -e 's/\\/\//g'
C:/Windows/Folder/File.txt

The sed command in this case is 's/OLD_TEXT/NEW_TEXT/g'.

The leading 's' just tells it to search for OLD_TEXT and replace it with NEW_TEXT.

The trailing 'g' just says to replace all occurrences on a given line, not just the first.

And of course you need to separate the 's', the 'g', the old, and the new from each other. This is where you must use forward slashes as separators.

For your case OLD_TEXT == '\' and NEW_TEXT == '/'. But you can't just go around typing slashes and expecting things to ~~work as expected~~ be taken literally while using them as separators at the same time. In general slashes are quite special and must be handled as such. They must be 'escaped' (i.e. preceded) by a backslash.

So for you, OLD_TEXT == '\\' and NEW_TEXT == '\/'. Putting these inside the 's/OLD_TEXT/NEW_TEXT/g' paradigm you get
's/\\/\//g'. That reads as
's / \\ / \/ / g' and after escapes is
's / \ / / / g' which will replace all backslashes with forward slashes.

How do I keep jQuery UI Accordion collapsed by default?

Add the active: false option (documentation)..

$("#accordion").accordion({ header: "h3", collapsible: true, active: false });

Calculate distance in meters when you know longitude and latitude in java

Based on another question on stackoverflow, I got this code.. This calculates the result in meters, not in miles :)

 public static float distFrom(float lat1, float lng1, float lat2, float lng2) {
    double earthRadius = 6371000; //meters
    double dLat = Math.toRadians(lat2-lat1);
    double dLng = Math.toRadians(lng2-lng1);
    double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
               Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) *
               Math.sin(dLng/2) * Math.sin(dLng/2);
    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
    float dist = (float) (earthRadius * c);

    return dist;
    }

Changing case in Vim

See the following methods:

 ~    : Changes the case of current character

 guu  : Change current line from upper to lower.

 gUU  : Change current LINE from lower to upper.

 guw  : Change to end of current WORD from upper to lower.

 guaw : Change all of current WORD to lower.

 gUw  : Change to end of current WORD from lower to upper.

 gUaw : Change all of current WORD to upper.

 g~~  : Invert case to entire line

 g~w  : Invert case to current WORD

 guG : Change to lowercase until the end of document.

How to get class object's name as a string in Javascript?

You can do it converting by the constructor to a string using .toString() :

function getObjectClass(obj){
   if (typeof obj != "object" || obj === null) return false;
   else return /(\w+)\(/.exec(obj.constructor.toString())[1];}

How to avoid page refresh after button click event in asp.net

Set MaintainScrollPositionOnPostBack="true" in the page declaration:

<%@ Page Language="C#" MaintainScrollPositionOnPostBack="true" Title="Home" %>

Get column index from label in a data frame

Here is an answer that will generalize Henrik's answer.

df=data.frame(A=rnorm(100), B=rnorm(100), C=rnorm(100))
numeric_columns<-c('A', 'B', 'C')
numeric_index<-sapply(1:length(numeric_columns), function(i)
grep(numeric_columns[i], colnames(df)))

dyld: Library not loaded: @rpath/libswiftCore.dylib

Xcode 7.2, iOS 9.2 on one device, 9.0 on other. Both had the error. No idea what changed that caused it, but the solutions above for the WWDR were correct for me. Install that cert and problem solved.

https://forums.developer.apple.com/message/43547 https://forums.developer.apple.com/message/84846

The type or namespace name 'System' could not be found

i had to upgrade from visual studio 2017 to 2019. no other proposed solution here helped me, i installed and configured, rebooted every one here plus many other options from ms site.

my root cause was probably due to the fact the git repository developer used 2019 and i tried to clone the original git repo into ma 2017.

Dynamically Changing log4j log level

If you would want to change the logging level of all the loggers use the below method. This will enumerate over all the loggers and change the logging level to given level. Please make sure that you DO NOT have log4j.appender.loggerName.Threshold=DEBUG property set in your log4j.properties file.

public static void changeLogLevel(Level level) {
    Enumeration<?> loggers = LogManager.getCurrentLoggers();
    while(loggers.hasMoreElements()) {
        Logger logger = (Logger) loggers.nextElement();
        logger.setLevel(level);
    }
}

Normalize columns of pandas data frame

Simple is Beautiful:

df["A"] = df["A"] / df["A"].max()
df["B"] = df["B"] / df["B"].max()
df["C"] = df["C"] / df["C"].max()

Spring Boot Adding Http Request Interceptors

WebMvcConfigurerAdapter will be deprecated with Spring 5. From its Javadoc:

@deprecated as of 5.0 {@link WebMvcConfigurer} has default methods (made possible by a Java 8 baseline) and can be implemented directly without the need for this adapter

As stated above, what you should do is implementing WebMvcConfigurer and overriding addInterceptors method.

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new MyCustomInterceptor());
    }
}

Backup/Restore a dockerized PostgreSQL database

Okay, I've figured this out. Postgresql does not detect changes to the folder /var/lib/postgresql once it's launched, at least not the kind of changes I want it do detect.

The first solution is to start a container with bash instead of starting the postgres server directly, restore the data, and then start the server manually.

The second solution is to use a data container. I didn't get the point of it before, now I do. This data container allows to restore the data before starting the postgres container. Thus, when the postgres server starts, the data are already there.

jQuery: print_r() display equivalent?

Top comment has a broken link to the console.log documentation for Firebug, so here is a link to the wiki article about Console. I started using it and am quite satisfied with it as an alternative to PHP's print_r().

Also of note is that Firebug gives you access to returned JSON objects even without you manually logging them:

In the console you can see the url of the AJAX response.
Click the triangle to expand the response and see details.
Click the JSON tab in the details.
You will see the response data organized with expansion triangles.

This method take a couple more clicks to get at the data but doesn't require any additions in your actual javascript and doesn't shift your focus in Firebug out of the console (using console.log creates a link to the DOM section of firebug, forcing you to click back to console after).

For my money I'd rather click a couple more times when I want to inspect rather than mess around with the log, especially since keeps the console neat by not adding any additional cruft.

Specifying maxlength for multiline textbox

use custom attribute maxsize="100"

<asp:TextBox ID="txtAddress" runat="server"  maxsize="100"
      Columns="17" Rows="4" TextMode="MultiLine"></asp:TextBox>
   <script>
       $("textarea[maxsize]").each(function () {
         $(this).attr('maxlength', $(this).attr('maxsize'));
         $(this).removeAttr('maxsize'); 
       });
   </script>

this will render like this

<textarea name="ctl00$BodyContentPlac
eHolder$txtAddress" rows="4" cols="17" id="txtAddress" maxlength="100"></textarea>

Programs & Examples On #Hiddenfield

Only on Firefox "Loading failed for the <script> with source"

How to call javascript function on page load in asp.net

ASP.NET set hiddenfield a value in Javascript

posting hidden value

What causing this "Invalid length for a Base-64 char array"

After submitting a POST form open a new window showing the result

How to pass a form input value into a JavaScript function

How can I populate a select dropdown list from a JSON feed with AngularJS?

error: ORA-65096: invalid common user or role name in oracle

Remove elements from collection while iterating

Mac install and open mysql using terminal

Responsive dropdown navbar with angular-ui bootstrap (done in the correct angular kind of way)

Update 2015-06

Ancient..

Making heatmap from pandas DataFrame

undefined reference to 'std::cout'

How to rsync only a specific list of files?

How to add action listener that listens to multiple buttons

Android background music service

error: function returns address of local variable

Using union and count(*) together in SQL query

Cookies vs. sessions

import android packages cannot be resolved

Reset AutoIncrement in SQL Server after Delete

Removing MySQL 5.7 Completely

How to put img inline with text

How to check whether a Storage item is set?

Reference member variables as class members

Create a CSV File for a user in PHP

Why am I getting error for apple-touch-icon-precomposed.png

Android - android.os.NetworkOnMainThreadException

Why do 64-bit DLLs go to System32 and 32-bit DLLs to SysWoW64 on 64-bit Windows?

How to get the first element of an array?

Making HTML page zoom by default

What is a .pid file and what does it contain?

What is PAGEIOLATCH_SH wait type in SQL Server?

Rails and PostgreSQL: Role postgres does not exist

How to perform update operations on columns of type JSONB in Postgres 9.4

HTML Button : Navigate to Other Page - Different Approaches

Using if elif fi in shell scripts

How do I align a number like this in C?

What is the best way to initialize a JavaScript Date to midnight?

How to programmatically clear application data

How to concatenate strings in windows batch file for loop?

Declaration of Methods should be Compatible with Parent Methods in PHP

How to calculate the sentence similarity using word2vec model of gensim with python

How to add RSA key to authorized_keys file?

To overwrite authorized_keys

To append to the end of authorized_keys

301 or 302 Redirection With PHP

Best way to copy a database (SQL Server 2008)

BeanFactory not initialized or already closed - call 'refresh' before

Str_replace for multiple items

Convert array of indices to 1-hot encoded numpy array

What is the best alternative IDE to Visual Studio

Histogram with Logarithmic Scale and custom breaks

ASP.Net MVC – Resource Cannot be found error

How to create Select List for Country and States/province in MVC

Return string Input with parse.string

Get month name from Date

Android Fastboot devices not returning device

What is sr-only in Bootstrap 3?

OpenSSL: unable to verify the first certificate for Experian URL

TypeScript add Object to array with push

Update query using Subquery in Sql Server

How do I display the current value of an Android Preference in the Preference summary?

What is the use of a private static variable in Java?

Python: download a file from an FTP server

How to validate white spaces/empty spaces? [Angular 2]

How do I convert NSMutableArray to NSArray?

Change Input to Upper Case

JOptionPane Input to int

create a text file using javascript

Non-static method requires a target

Getting raw SQL query string from PDO prepared statements

How to group dataframe rows into list in pandas groupby

$_SERVER["REMOTE_ADDR"] gives server IP rather than visitor IP

PowerShell script to check the status of a URL

Adding Google Play services version to your app's manifest?

Using the `constructor` property...

Using the `instanceof` operator...

Using the `name` property of the `constructor` property...