Programs & Examples On #Split button

A button on a user interface that when clicked displays a list of options of which one must be selected.

How to best display in Terminal a MySQL SELECT returning too many fields?

I wrote pspg - https://github.com/okbob/pspg

This pager is designed for tabular data - and MySQL is supported too.

MariaDB [sakila]> pager pspg -s 14 -X --force-uniborder --quit-if-one-screen
PAGER set to 'pspg -s 14 -X --force-uniborder --quit-if-one-screen'
MariaDB [sakila]> select now();
MariaDB [sakila]> select * from nicer_but_slower_film_list limit 100;

Bash or KornShell (ksh)?

Bash is the standard for Linux.
My experience is that it is easier to find help for bash than for ksh or csh.

Already defined in .obj - no double inclusions

I do recomend doing it in 2 filles (.h .cpp) But if u lazy just add inline before the function So it will look something like this

inline void functionX() 
{ }

more about inline functions:

The inline functions are a C++ enhancement feature to increase the execution time of a program. Functions can be instructed to compiler to make them inline so that compiler can replace those function definition wherever those are being called. Compiler replaces the definition of inline functions at compile time instead of referring function definition at runtime. NOTE- This is just a suggestion to compiler to make the function inline, if function is big (in term of executable instruction etc) then, compiler can ignore the “inline” request and treat the function as normal function.

more info here

Java Garbage Collection Log messages

  1. PSYoungGen refers to the garbage collector in use for the minor collection. PS stands for Parallel Scavenge.
  2. The first set of numbers are the before/after sizes of the young generation and the second set are for the entire heap. (Diagnosing a Garbage Collection problem details the format)
  3. The name indicates the generation and collector in question, the second set are for the entire heap.

An example of an associated full GC also shows the collectors used for the old and permanent generations:

3.757: [Full GC [PSYoungGen: 2672K->0K(35584K)] 
            [ParOldGen: 3225K->5735K(43712K)] 5898K->5735K(79296K) 
            [PSPermGen: 13533K->13516K(27584K)], 0.0860402 secs]

Finally, breaking down one line of your example log output:

8109.128: [GC [PSYoungGen: 109884K->14201K(139904K)] 691015K->595332K(1119040K), 0.0454530 secs]
  • 107Mb used before GC, 14Mb used after GC, max young generation size 137Mb
  • 675Mb heap used before GC, 581Mb heap used after GC, 1Gb max heap size
  • minor GC occurred 8109.128 seconds since the start of the JVM and took 0.04 seconds

Concatenate two slices in Go

I would like to emphasize @icza answer and simplify it a bit since it is a crucial concept. I assume that reader is familiar with slices.

c := append(a, b...)

This is a valid answer to the question. BUT if you need to use slices 'a' and 'c' later in code in different context, this is not the safe way to concatenate slices.

To explain, lets read the expression not in terms of slices, but in terms of underlying arrays:

"Take (underlying) array of 'a' and append elements from array 'b' to it. If array 'a' has enough capacity to include all elements from 'b' - underlying array of 'c' will not be a new array, it will actually be array 'a'. Basically, slice 'a' will show len(a) elements of underlying array 'a', and slice 'c' will show len(c) of array 'a'."

append() does not necessarily create a new array! This can lead to unexpected results. See Go Playground example.

Always use make() function if you want to make sure that new array is allocated for the slice. For example here are few ugly but efficient enough options for the task.

la := len(a)
c := make([]int, la, la + len(b))
_ = copy(c, a)
c = append(c, b...)

la := len(a)
c := make([]int, la + len(b))
_ = copy(c, a)
_ = copy(c[la:], b)

How to deploy correctly when using Composer's develop / production switch?

Now require-dev is enabled by default, for local development you can do composer install and composer update without the --dev option.

When you want to deploy to production, you'll need to make sure composer.lock doesn't have any packages that came from require-dev.

You can do this with

composer update --no-dev

Once you've tested locally with --no-dev you can deploy everything to production and install based on the composer.lock. You need the --no-dev option again here, otherwise composer will say "The lock file does not contain require-dev information".

composer install --no-dev

Note: Be careful with anything that has the potential to introduce differences between dev and production! I generally try to avoid require-dev wherever possible, as including dev tools isn't a big overhead.

Python - IOError: [Errno 13] Permission denied:

It looks like you're trying to replace the extension with the following code:

if (myFile[-4:] == ".asm"):
    newFile = myFile[:4]+".hack"

However, you appear to have the array indexes mixed up. Try the following:

if (myFile[-4:] == ".asm"):
    newFile = myFile[:-4]+".hack"

Note the use of -4 instead of just 4 in the second line of code. This explains why your program is trying to create /Use.hack, which is the first four characters of your file name (/Use), with .hack appended to it.

Return row of Data Frame based on value in a column - R

Use which.min:

df <- data.frame(Name=c('A','B','C','D'), Amount=c(150,120,175,160))
df[which.min(df$Amount),]

> df[which.min(df$Amount),]
  Name Amount
2    B    120

From the help docs:

Determines the location, i.e., index of the (first) minimum or maximum of a numeric (or logical) vector.

How to layout multiple panels on a jFrame? (java)

The JPanel is actually only a container where you can put different elements in it (even other JPanels). So in your case I would suggest one big JPanel as some sort of main container for your window. That main panel you assign a Layout that suits your needs ( here is an introduction to the layouts).

After you set the layout to your main panel you can add the paint panel and the other JPanels you want (like those with the text in it..).

  JPanel mainPanel = new JPanel();
  mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.Y_AXIS));

  JPanel paintPanel = new JPanel();
  JPanel textPanel = new JPanel();

  mainPanel.add(paintPanel);
  mainPanel.add(textPanel);

This is just an example that sorts all sub panels vertically (Y-Axis). So if you want some other stuff at the bottom of your mainPanel (maybe some icons or buttons) that should be organized with another layout (like a horizontal layout), just create again a new JPanel as a container for all the other stuff and set setLayout(new BoxLayout(mainPanel, BoxLayout.X_AXIS).

As you will find out, the layouts are quite rigid and it may be difficult to find the best layout for your panels. So don't give up, read the introduction (the link above) and look at the pictures – this is how I do it :)

Or you can just use NetBeans to write your program. There you have a pretty easy visual editor (drag and drop) to create all sorts of Windows and Frames. (only understanding the code afterwards is ... tricky sometimes.)

EDIT

Since there are some many people interested in this question, I wanted to provide a complete example of how to layout a JFrame to make it look like OP wants it to.

The class is called MyFrame and extends swings JFrame

public class MyFrame extends javax.swing.JFrame{

    // these are the components we need.
    private final JSplitPane splitPane;  // split the window in top and bottom
    private final JPanel topPanel;       // container panel for the top
    private final JPanel bottomPanel;    // container panel for the bottom
    private final JScrollPane scrollPane; // makes the text scrollable
    private final JTextArea textArea;     // the text
    private final JPanel inputPanel;      // under the text a container for all the input elements
    private final JTextField textField;   // a textField for the text the user inputs
    private final JButton button;         // and a "send" button

    public MyFrame(){

        // first, lets create the containers:
        // the splitPane devides the window in two components (here: top and bottom)
        // users can then move the devider and decide how much of the top component
        // and how much of the bottom component they want to see.
        splitPane = new JSplitPane();

        topPanel = new JPanel();         // our top component
        bottomPanel = new JPanel();      // our bottom component

        // in our bottom panel we want the text area and the input components
        scrollPane = new JScrollPane();  // this scrollPane is used to make the text area scrollable
        textArea = new JTextArea();      // this text area will be put inside the scrollPane

        // the input components will be put in a separate panel
        inputPanel = new JPanel();
        textField = new JTextField();    // first the input field where the user can type his text
        button = new JButton("send");    // and a button at the right, to send the text

        // now lets define the default size of our window and its layout:
        setPreferredSize(new Dimension(400, 400));     // let's open the window with a default size of 400x400 pixels
        // the contentPane is the container that holds all our components
        getContentPane().setLayout(new GridLayout());  // the default GridLayout is like a grid with 1 column and 1 row,
        // we only add one element to the window itself
        getContentPane().add(splitPane);               // due to the GridLayout, our splitPane will now fill the whole window

        // let's configure our splitPane:
        splitPane.setOrientation(JSplitPane.VERTICAL_SPLIT);  // we want it to split the window verticaly
        splitPane.setDividerLocation(200);                    // the initial position of the divider is 200 (our window is 400 pixels high)
        splitPane.setTopComponent(topPanel);                  // at the top we want our "topPanel"
        splitPane.setBottomComponent(bottomPanel);            // and at the bottom we want our "bottomPanel"

        // our topPanel doesn't need anymore for this example. Whatever you want it to contain, you can add it here
        bottomPanel.setLayout(new BoxLayout(bottomPanel, BoxLayout.Y_AXIS)); // BoxLayout.Y_AXIS will arrange the content vertically

        bottomPanel.add(scrollPane);                // first we add the scrollPane to the bottomPanel, so it is at the top
        scrollPane.setViewportView(textArea);       // the scrollPane should make the textArea scrollable, so we define the viewport
        bottomPanel.add(inputPanel);                // then we add the inputPanel to the bottomPanel, so it under the scrollPane / textArea

        // let's set the maximum size of the inputPanel, so it doesn't get too big when the user resizes the window
        inputPanel.setMaximumSize(new Dimension(Integer.MAX_VALUE, 75));     // we set the max height to 75 and the max width to (almost) unlimited
        inputPanel.setLayout(new BoxLayout(inputPanel, BoxLayout.X_AXIS));   // X_Axis will arrange the content horizontally

        inputPanel.add(textField);        // left will be the textField
        inputPanel.add(button);           // and right the "send" button

        pack();   // calling pack() at the end, will ensure that every layout and size we just defined gets applied before the stuff becomes visible
    }

    public static void main(String args[]){
        EventQueue.invokeLater(new Runnable(){
            @Override
            public void run(){
                new MyFrame().setVisible(true);
            }
        });
    }
}

Please be aware that this is only an example and there are multiple approaches to layout a window. It all depends on your needs and if you want the content to be resizable / responsive. Another really good approach would be the GridBagLayout which can handle quite complex layouting, but which is also quite complex to learn.

What is the maximum characters for the NVARCHAR(MAX)?

I think actually nvarchar(MAX) can store approximately 1070000000 chars.

How can I use jQuery to make an input readonly?

The setReadOnly(state) is very useful for forms, we can set any field to setReadOnly(state) directly or from various condition.But I prefer to use readOnly for setting opacity to the selector otherwise the attr='disabled' also worked like the same way.

readOnly examples:

$('input').setReadOnly(true);

or through the various codition like

var same = this.checked;
$('input').setReadOnly(same);

here we are using the state boolean value to set and remove readonly attribute from the input depending on a checkbox click.

Experimental decorators warning in TypeScript compilation

I had this problem recently under Visual Studio 2017 - turned out it was caused by a "feature" of VS - ignoring tsconfig.json when Build action is not set to Content.

So changing the Build action to Content and reloading the solution solved the problem.

What is the difference between declarations, providers, and import in NgModule?

Angular Concepts

  • imports makes the exported declarations of other modules available in the current module
  • declarations are to make directives (including components and pipes) from the current module available to other directives in the current module. Selectors of directives, components or pipes are only matched against the HTML if they are declared or imported.
  • providers are to make services and values known to DI (dependency injection). They are added to the root scope and they are injected to other services or directives that have them as dependency.

A special case for providers are lazy loaded modules that get their own child injector. providers of a lazy loaded module are only provided to this lazy loaded module by default (not the whole application as it is with other modules).

For more details about modules see also https://angular.io/docs/ts/latest/guide/ngmodule.html

  • exports makes the components, directives, and pipes available in modules that add this module to imports. exports can also be used to re-export modules such as CommonModule and FormsModule, which is often done in shared modules.

  • entryComponents registers components for offline compilation so that they can be used with ViewContainerRef.createComponent(). Components used in router configurations are added implicitly.

TypeScript (ES2015) imports

import ... from 'foo/bar' (which may resolve to an index.ts) are for TypeScript imports. You need these whenever you use an identifier in a typescript file that is declared in another typescript file.

Angular's @NgModule() imports and TypeScript import are entirely different concepts.

See also jDriven - TypeScript and ES6 import syntax

Most of them are actually plain ECMAScript 2015 (ES6) module syntax that TypeScript uses as well.

Is it possible to declare a public variable in vba and assign a default value?

Sure you know, but if its a constant then const MyVariable as Integer = 123 otherwise your out of luck; the variable must be assigned an initial value elsewhere.

You could:

public property get myIntegerThing() as integer
    myIntegerThing= 123
end property

In a Class module then globally create it;

public cMyStuff as new MyStuffClass

So cMyStuff.myIntegerThing is available immediately.

How to copy java.util.list Collection

You may create a new list with an input of a previous list like so:

List one = new ArrayList()
//... add data, sort, etc
List two = new ArrayList(one);

This will allow you to modify the order or what elemtents are contained independent of the first list.

Keep in mind that the two lists will contain the same objects though, so if you modify an object in List two, the same object will be modified in list one.

example:

MyObject value1 = one.get(0);
MyObject value2 = two.get(0);
value1 == value2 //true
value1.setName("hello");
value2.getName(); //returns "hello"

Edit

To avoid this you need a deep copy of each element in the list like so:

List<Torero> one = new ArrayList<Torero>();
//add elements

List<Torero> two = new Arraylist<Torero>();
for(Torero t : one){
    Torero copy = deepCopy(t);
    two.add(copy);
}

with copy like the following:

public Torero deepCopy(Torero input){
    Torero copy = new Torero();
    copy.setValue(input.getValue());//.. copy primitives, deep copy objects again

    return copy;
}

Why do I get AttributeError: 'NoneType' object has no attribute 'something'?

NoneType means that instead of an instance of whatever Class or Object you think you're working with, you've actually got None. That usually means that an assignment or function call up above failed or returned an unexpected result.

How do I read a date in Excel format in Python?

xlrd.xldate_as_tuple is nice, but there's xlrd.xldate.xldate_as_datetime that converts to datetime as well.

import xlrd
wb = xlrd.open_workbook(filename)
xlrd.xldate.xldate_as_datetime(41889, wb.datemode)
=> datetime.datetime(2014, 9, 7, 0, 0)

get all the images from a folder in php

This answer is specific for WordPress:

$base_dir = trailingslashit( get_stylesheet_directory() );
$base_url = trailingslashit( get_stylesheet_directory_uri() );

$media_dir = $base_dir . 'yourfolder/images/';
$media_url = $hase_url . 'yourfolder/images/';

$image_paths = glob( $media_dir . '*.jpg' );
$image_names = array();
$image_urls = array();

foreach ( $image_paths as $image ) {
    $image_names[] = str_replace( $media_dir, '', $image );
    $image_urls[] = str_replace( $media_dir, $media_url, $image );
}

// --- You now have:

// $image_paths ... list of absolute file paths 
// e.g. /path/to/wordpress/wp-content/uploads/yourfolder/images/sample.jpg

// $image_urls ... list of absolute file URLs 
// e.g. http://example.com/wp-content/uploads/yourfolder/images/sample.jpg

// $image_names ... list of filenames only
// e.g. sample.jpg

Here are some other settings that will give you images from other places than the child theme. Just replace the first 2 lines in above code with the version you need:

From Uploads directory:

// e.g. /path/to/wordpress/wp-content/uploads/yourfolder/images/sample.jpg
$upload_path = wp_upload_dir();
$base_dir = trailingslashit( $upload_path['basedir'] );
$base_url = trailingslashit( $upload_path['baseurl'] );

From Parent-Theme

// e.g. /path/to/wordpress/wp-content/themes/parent-theme/yourfolder/images/sample.jpg
$base_dir = trailingslashit( get_template_directory() );
$base_url = trailingslashit( get_template_directory_uri() );

From Child-Theme

// e.g. /path/to/wordpress/wp-content/themes/child-theme/yourfolder/images/sample.jpg
$base_dir = trailingslashit( get_stylesheet_directory() );
$base_url = trailingslashit( get_stylesheet_directory_uri() );

how to get text from textview

Try Like this.

tv1.setText("  " + Integer.toString(X[i]) + "\n" + "+" + " " + Integer.toString(Y[i]));

Reading data from XML

Alternatively, you can use XPathNavigator:

XmlDocument doc = new XmlDocument();
doc.LoadXml(xml);
XPathNavigator navigator = doc.CreateNavigator();

string books = GetStringValues("Books: ", navigator, "//Book/Title");
string authors = GetStringValues("Authors: ", navigator, "//Book/Author");

..

/// <summary>
/// Gets the string values.
/// </summary>
/// <param name="description">The description.</param>
/// <param name="navigator">The navigator.</param>
/// <param name="xpath">The xpath.</param>
/// <returns></returns>
private static string GetStringValues(string description,
                                      XPathNavigator navigator, string xpath) {
    StringBuilder sb = new StringBuilder();
    sb.Append(description);
    XPathNodeIterator bookNodesIterator = navigator.Select(xpath);
    while (bookNodesIterator.MoveNext())
       sb.Append(string.Format("{0} ", bookNodesIterator.Current.Value));
    return sb.ToString();
}

(Deep) copying an array using jQuery

Everything in JavaScript is pass by reference, so if you want a true deep copy of the objects in the array, the best method I can think of is to serialize the entire array to JSON and then de-serialize it back.

Test iOS app on device without apple developer program or jailbreak

It's worth the buck to apply for the Apple developer program. You will be able to use ad-hoc provisioning to distribute your app to testers and test devices. You're allowed to add 100 ad-hoc provisioning devices to your developer program.

Error Code: 2013. Lost connection to MySQL server during query

This happened to me because my innodb_buffer_pool_size was set to be larger than the RAM size available on the server. Things were getting interrupted because of this and it issues this error. The fix is to update my.cnf with the correct setting for innodb_buffer_pool_size.

Tab key == 4 spaces and auto-indent after curly braces in Vim

Related, if you open a file that uses both tabs and spaces, assuming you've got

set expandtab ts=4 sw=4 ai

You can replace all the tabs with spaces in the entire file with

:%retab

How can I programmatically freeze the top row of an Excel worksheet in Excel 2007 VBA?

Rows("2:2").Select
ActiveWindow.FreezePanes = True

This is the easiest way to freeze the top row. The rule for FreezePanes is it will freeze the upper left corner from the cell you selected. For example, if you highlight C10, it will freeze between columns B and C, rows 9 and 10. So when you highlight Row 2, it actually freeze between Rows 1 and 2 which is the top row.

Also, the .SplitColumn or .SplitRow will split your window once you unfreeze it which is not the way I like.

Can we have multiple <tbody> in same <table>?

Yes. From the DTD

<!ELEMENT table
     (caption?, (col*|colgroup*), thead?, tfoot?, (tbody+|tr+))>

So it expects one or more. It then goes on to say

Use multiple tbody sections when rules are needed between groups of table rows.

How to add/update child entities when updating a parent entity in EF

Because the model that gets posted to the WebApi controller is detached from any entity-framework (EF) context, the only option is to load the object graph (parent including its children) from the database and compare which children have been added, deleted or updated. (Unless you would track the changes with your own tracking mechanism during the detached state (in the browser or wherever) which in my opinion is more complex than the following.) It could look like this:

public void Update(UpdateParentModel model)
{
    var existingParent = _dbContext.Parents
        .Where(p => p.Id == model.Id)
        .Include(p => p.Children)
        .SingleOrDefault();

    if (existingParent != null)
    {
        // Update parent
        _dbContext.Entry(existingParent).CurrentValues.SetValues(model);

        // Delete children
        foreach (var existingChild in existingParent.Children.ToList())
        {
            if (!model.Children.Any(c => c.Id == existingChild.Id))
                _dbContext.Children.Remove(existingChild);
        }

        // Update and Insert children
        foreach (var childModel in model.Children)
        {
            var existingChild = existingParent.Children
                .Where(c => c.Id == childModel.Id && c.Id != default(int))
                .SingleOrDefault();

            if (existingChild != null)
                // Update child
                _dbContext.Entry(existingChild).CurrentValues.SetValues(childModel);
            else
            {
                // Insert child
                var newChild = new Child
                {
                    Data = childModel.Data,
                    //...
                };
                existingParent.Children.Add(newChild);
            }
        }

        _dbContext.SaveChanges();
    }
}

...CurrentValues.SetValues can take any object and maps property values to the attached entity based on the property name. If the property names in your model are different from the names in the entity you can't use this method and must assign the values one by one.

Is there a cross-domain iframe height auto-resizer that works?

You have three alternatives:

1. Use iFrame-resizer

This is a simple library for keeping iFrames sized to their content. It uses the PostMessage and MutationObserver APIs, with fall backs for IE8-10. It also has options for the content page to request the containing iFrame is a certain size and can also close the iFrame when your done with it.

https://github.com/davidjbradshaw/iframe-resizer

2. Use Easy XDM (PostMessage + Flash combo)

Easy XDM uses a collection of tricks for enabling cross-domain communication between different windows in a number of browsers, and there are examples for using it for iframe resizing:

http://easyxdm.net/wp/2010/03/17/resize-iframe-based-on-content/

http://kinsey.no/blog/index.php/2010/02/19/resizing-iframes-using-easyxdm/

Easy XDM works by using PostMessage on modern browsers and a Flash based solution as fallback for older browsers.

See also this thread on Stackoverflow (there are also others, this is a commonly asked question). Also, Facebook would seem to use a similar approach.

3. Communicate via a server

Another option would be to send the iframe height to your server and then poll from that server from the parent web page with JSONP (or use a long poll if possible).

How to PUT a json object with an array using curl

Your command line should have a -d/--data inserted before the string you want to send in the PUT, and you want to set the Content-Type and not Accept.

curl -H 'Content-Type: application/json' -X PUT -d '[JSON]' \
     http://example.com/service

Using the exact JSON data from the question, the full command line would become:

curl -H 'Content-Type: application/json' -X PUT \
    -d '{"tags":["tag1","tag2"],
         "question":"Which band?",
         "answers":[{"id":"a0","answer":"Answer1"},
                    {"id":"a1","answer":"answer2"}]}' \
    http://example.com/service

Note: JSON data wrapped only for readability, not valid for curl request.

Set Canvas size using javascript

You can also use this script , just change the height and width

<canvas id="Canvas01" width="500" height="400" style="border:2px solid #FF9933; margin-left:10px; margin-top:10px;"></canvas>

   <script>
      var canvas = document.getElementById("Canvas01");
      var ctx = canvas.getContext("2d");

Validate decimal numbers in JavaScript - IsNumeric()

A simple and clean solution by leveraging language's dynamic type checking:

function IsNumeric (string) {
   if(string === ' '.repeat(string.length)){
     return false
   }
   return string - 0 === string * 1
}

if you don't care about white-spaces you can remove that " if "

see test cases below

_x000D_
_x000D_
function IsNumeric (string) {_x000D_
   if(string === ' '.repeat(string.length)){_x000D_
      return false_x000D_
   }_x000D_
   return string - 0 === string * 1_x000D_
}_x000D_
_x000D_
_x000D_
console.log('-1' + ' ? ' + IsNumeric('-1'))    _x000D_
console.log('-1.5' + ' ? ' + IsNumeric('-1.5')) _x000D_
console.log('0' + ' ? ' + IsNumeric('0'))     _x000D_
console.log('0.42' + ' ? ' + IsNumeric('0.42'))   _x000D_
console.log('.42' + ' ? ' + IsNumeric('.42'))    _x000D_
console.log('99,999' + ' ? ' + IsNumeric('99,999'))_x000D_
console.log('0x89f' + ' ? ' + IsNumeric('0x89f'))  _x000D_
console.log('#abcdef' + ' ? ' + IsNumeric('#abcdef'))_x000D_
console.log('1.2.3' + ' ? ' + IsNumeric('1.2.3')) _x000D_
console.log('' + ' ? ' + IsNumeric(''))    _x000D_
console.log('33 ' + ' ? ' + IsNumeric('33 '))
_x000D_
_x000D_
_x000D_

how to align img inside the div to the right?

<p>
  <img style="float: right; margin: 0px 15px 15px 0px;" src="files/styles/large_hero_desktop_1x/public/headers/Kids%20on%20iPad%20 %202400x880.jpg?itok=PFa-MXyQ" width="100" />
  Nunc pulvinar lacus id purus ultrices id sagittis neque convallis. Nunc vel libero orci. 
  <br style="clear: both;" />
</p>

How to Use Content-disposition for force a file to download to the hard drive?

On the HTTP Response where you are returning the PDF file, ensure the content disposition header looks like:

Content-Disposition: attachment; filename=quot.pdf;

See content-disposition on the wikipedia MIME page.

MySql: is it possible to 'SUM IF' or to 'COUNT IF'?

It is worth noting that you can build upon Gavin Toweys answer by using multiple fields from across your query such as

SUM(table.field = 1 AND table2.field = 2)

You can also use this syntax for COUNT and I am sure other functions as well.

jQuery - Check if DOM element already exists

No to compare anything, you can simply check that by this...,.

if(document.getElementById("url")){ alert('exit');}
if($("#url")){alert('exist');}

you can also use the html() function as well like

if($("#url).html()){alert('exist');}

ImportError: No module named 'encodings'

Look at /lib/python3.5 and you will see broken links to python libraries. Recreate it to working directory.

Next error -

./script/bin/pip3
Failed to import the site module
Traceback (most recent call last):
  File "/home/script/script/lib/python3.5/site.py", line 703, in <module>
    main()
  File "/home/script/script/lib/python3.5/site.py", line 683, in main
    paths_in_sys = addsitepackages(paths_in_sys)
  File "/home/script/script/lib/python3.5/site.py", line 282, in addsitepackages
    addsitedir(sitedir, known_paths)
  File "/home/script/script/lib/python3.5/site.py", line 204, in addsitedir
    addpackage(sitedir, name, known_paths)
  File "/home/script/script/lib/python3.5/site.py", line 173, in addpackage
    exec(line)
  File "<string>", line 1, in <module>
  File "/home/script/script/lib/python3.5/types.py", line 166, in <module>
    import functools as _functools
  File "/home/script/script/lib/python3.5/functools.py", line 23, in <module>
    from weakref import WeakKeyDictionary
  File "/home/script/script/lib/python3.5/weakref.py", line 12, in <module>
    from _weakref import (
ImportError: cannot import name '_remove_dead_weakref'

fixed like this - https://askubuntu.com/questions/907035/importerror-cannot-import-name-remove-dead-weakref

cd my-virtualenv-directory
virtualenv . --system-site-packages

How to run Java program in terminal with external library JAR

For compiling the java file having dependency on a jar

javac -cp path_of_the_jar/jarName.jar className.java

For executing the class file

java -cp .;path_of_the_jar/jarName.jar className

How are POST and GET variables handled in Python?

I know this is an old question. Yet it's surprising that no good answer was given.

First of all the question is completely valid without mentioning the framework. The CONTEXT is a PHP language equivalence. Although there are many ways to get the query string parameters in Python, the framework variables are just conveniently populated. In PHP, $_GET and $_POST are also convenience variables. They are parsed from QUERY_URI and php://input respectively.

In Python, these functions would be os.getenv('QUERY_STRING') and sys.stdin.read(). Remember to import os and sys modules.

We have to be careful with the word "CGI" here, especially when talking about two languages and their commonalities when interfacing with a web server. 1. CGI, as a protocol, defines the data transport mechanism in the HTTP protocol. 2. Python can be configured to run as a CGI-script in Apache. 3. The CGI module in Python offers some convenience functions.

Since the HTTP protocol is language-independent, and that Apache's CGI extension is also language-independent, getting the GET and POST parameters should bear only syntax differences across languages.

Here's the Python routine to populate a GET dictionary:

GET={}
args=os.getenv("QUERY_STRING").split('&')

for arg in args: 
    t=arg.split('=')
    if len(t)>1: k,v=arg.split('='); GET[k]=v

and for POST:

POST={}
args=sys.stdin.read().split('&')

for arg in args: 
    t=arg.split('=')
    if len(t)>1: k, v=arg.split('='); POST[k]=v

You can now access the fields as following:

print GET.get('user_id')
print POST.get('user_name')

I must also point out that the CGI module doesn't work well. Consider this HTTP request:

POST / test.py?user_id=6

user_name=Bob&age=30

Using CGI.FieldStorage().getvalue('user_id') will cause a null pointer exception because the module blindly checks the POST data, ignoring the fact that a POST request can carry GET parameters too.

Paging with LINQ for objects

Here is my performant approach to paging when using LINQ to objects:

public static IEnumerable<IEnumerable<T>> Page<T>(this IEnumerable<T> source, int pageSize)
{
    Contract.Requires(source != null);
    Contract.Requires(pageSize > 0);
    Contract.Ensures(Contract.Result<IEnumerable<IEnumerable<T>>>() != null);

    using (var enumerator = source.GetEnumerator())
    {
        while (enumerator.MoveNext())
        {
            var currentPage = new List<T>(pageSize)
            {
                enumerator.Current
            };

            while (currentPage.Count < pageSize && enumerator.MoveNext())
            {
                currentPage.Add(enumerator.Current);
            }
            yield return new ReadOnlyCollection<T>(currentPage);
        }
    }
}

This can then be used like so:

var items = Enumerable.Range(0, 12);

foreach(var page in items.Page(3))
{
    // Do something with each page
    foreach(var item in page)
    {
        // Do something with the item in the current page       
    }
}

None of this rubbish Skip and Take which will be highly inefficient if you are interested in multiple pages.

What does 'const static' mean in C and C++?

According to C99/GNU99 specification:

  • static

    • is storage-class specifier

    • objects of file level scope by default has external linkage

    • objects of file level scope with static specifier has internal linkage
  • const

    • is type-qualifier (is a part of type)

    • keyword applied to immediate left instance - i.e.

      • MyObj const * myVar; - unqualified pointer to const qualified object type

      • MyObj * const myVar; - const qualified pointer to unqualified object type

    • Leftmost usage - applied to the object type, not variable

      • const MyObj * myVar; - unqualified pointer to const qualified object type

THUS:

static NSString * const myVar; - constant pointer to immutable string with internal linkage.

Absence of the static keyword will make variable name global and might lead to name conflicts within the application.

post checkbox value

In your form tag, rather than

name="booking.php"

use

action="booking.php"

And then, in booking.php use

$checkValue = $_POST['booking-check'];

Also, you'll need a submit button in there

<input type='submit'>

Response.Redirect with POST instead of Get?

@Matt,

You can still use the HttpWebRequest, then direct the response you receive to the actual outputstream response, this would serve the response back to the user. The only issue is that any relative urls would be broken.

Still, that may work.

Simple Digit Recognition OCR in OpenCV-Python

OCR which stands for Optical Character Recognition is a computer vision technique used to identify the different types of handwritten digits that are used in common mathematics. To perform OCR in OpenCV we will use the KNN algorithm which detects the nearest k neighbors of a particular data point and then classifies that data point based on the class type detected for n neighbors.

Data Used


This data contains 5000 handwritten digits where there are 500 digits for every type of digit. Each digit is of 20×20 pixel dimensions. We will split the data such that 250 digits are for training and 250 digits are for testing for every class.

Below is the implementation.




import numpy as np
import cv2
   
      
# Read the image
image = cv2.imread('digits.png')
  
# gray scale conversion
gray_img = cv2.cvtColor(image,
                        cv2.COLOR_BGR2GRAY)
  
# We will divide the image
# into 5000 small dimensions 
# of size 20x20
divisions = list(np.hsplit(i,100) for i in np.vsplit(gray_img,50))
  
# Convert into Numpy array
# of size (50,100,20,20)
NP_array = np.array(divisions)
   
# Preparing train_data
# and test_data.
# Size will be (2500,20x20)
train_data = NP_array[:,:50].reshape(-1,400).astype(np.float32)
  
# Size will be (2500,20x20)
test_data = NP_array[:,50:100].reshape(-1,400).astype(np.float32)
  
# Create 10 different labels 
# for each type of digit
k = np.arange(10)
train_labels = np.repeat(k,250)[:,np.newaxis]
test_labels = np.repeat(k,250)[:,np.newaxis]
   
# Initiate kNN classifier
knn = cv2.ml.KNearest_create()
  
# perform training of data
knn.train(train_data,
          cv2.ml.ROW_SAMPLE, 
          train_labels)
   
# obtain the output from the
# classifier by specifying the
# number of neighbors.
ret, output ,neighbours,
distance = knn.findNearest(test_data, k = 3)
   
# Check the performance and
# accuracy of the classifier.
# Compare the output with test_labels
# to find out how many are wrong.
matched = output==test_labels
correct_OP = np.count_nonzero(matched)
   
#Calculate the accuracy.
accuracy = (correct_OP*100.0)/(output.size)
   
# Display accuracy.
print(accuracy)


Output

91.64


Well, I decided to workout myself on my question to solve the above problem. What I wanted is to implement a simple OCR using KNearest or SVM features in OpenCV. And below is what I did and how. (it is just for learning how to use KNearest for simple OCR purposes).

1) My first question was about letter_recognition.data file that comes with OpenCV samples. I wanted to know what is inside that file.

It contains a letter, along with 16 features of that letter.

And this SOF helped me to find it. These 16 features are explained in the paper Letter Recognition Using Holland-Style Adaptive Classifiers. (Although I didn't understand some of the features at the end)

2) Since I knew, without understanding all those features, it is difficult to do that method. I tried some other papers, but all were a little difficult for a beginner.

So I just decided to take all the pixel values as my features. (I was not worried about accuracy or performance, I just wanted it to work, at least with the least accuracy)

I took the below image for my training data:

enter image description here

(I know the amount of training data is less. But, since all letters are of the same font and size, I decided to try on this).

To prepare the data for training, I made a small code in OpenCV. It does the following things:

  1. It loads the image.
  2. Selects the digits (obviously by contour finding and applying constraints on area and height of letters to avoid false detections).
  3. Draws the bounding rectangle around one letter and wait for key press manually. This time we press the digit key ourselves corresponding to the letter in the box.
  4. Once the corresponding digit key is pressed, it resizes this box to 10x10 and saves all 100 pixel values in an array (here, samples) and corresponding manually entered digit in another array(here, responses).
  5. Then save both the arrays in separate .txt files.

At the end of the manual classification of digits, all the digits in the training data (train.png) are labeled manually by ourselves, image will look like below:

enter image description here

Below is the code I used for the above purpose (of course, not so clean):

import sys

import numpy as np
import cv2

im = cv2.imread('pitrain.png')
im3 = im.copy()

gray = cv2.cvtColor(im,cv2.COLOR_BGR2GRAY)
blur = cv2.GaussianBlur(gray,(5,5),0)
thresh = cv2.adaptiveThreshold(blur,255,1,1,11,2)

#################      Now finding Contours         ###################

contours,hierarchy = cv2.findContours(thresh,cv2.RETR_LIST,cv2.CHAIN_APPROX_SIMPLE)

samples =  np.empty((0,100))
responses = []
keys = [i for i in range(48,58)]

for cnt in contours:
    if cv2.contourArea(cnt)>50:
        [x,y,w,h] = cv2.boundingRect(cnt)
        
        if  h>28:
            cv2.rectangle(im,(x,y),(x+w,y+h),(0,0,255),2)
            roi = thresh[y:y+h,x:x+w]
            roismall = cv2.resize(roi,(10,10))
            cv2.imshow('norm',im)
            key = cv2.waitKey(0)

            if key == 27:  # (escape to quit)
                sys.exit()
            elif key in keys:
                responses.append(int(chr(key)))
                sample = roismall.reshape((1,100))
                samples = np.append(samples,sample,0)

responses = np.array(responses,np.float32)
responses = responses.reshape((responses.size,1))
print "training complete"

np.savetxt('generalsamples.data',samples)
np.savetxt('generalresponses.data',responses)

Now we enter in to training and testing part.

For the testing part, I used the below image, which has the same type of letters I used for the training phase.

enter image description here

For training we do as follows:

  1. Load the .txt files we already saved earlier
  2. create an instance of the classifier we are using (it is KNearest in this case)
  3. Then we use KNearest.train function to train the data

For testing purposes, we do as follows:

  1. We load the image used for testing
  2. process the image as earlier and extract each digit using contour methods
  3. Draw a bounding box for it, then resize it to 10x10, and store its pixel values in an array as done earlier.
  4. Then we use KNearest.find_nearest() function to find the nearest item to the one we gave. ( If lucky, it recognizes the correct digit.)

I included last two steps (training and testing) in single code below:

import cv2
import numpy as np

#######   training part    ############### 
samples = np.loadtxt('generalsamples.data',np.float32)
responses = np.loadtxt('generalresponses.data',np.float32)
responses = responses.reshape((responses.size,1))

model = cv2.KNearest()
model.train(samples,responses)

############################# testing part  #########################

im = cv2.imread('pi.png')
out = np.zeros(im.shape,np.uint8)
gray = cv2.cvtColor(im,cv2.COLOR_BGR2GRAY)
thresh = cv2.adaptiveThreshold(gray,255,1,1,11,2)

contours,hierarchy = cv2.findContours(thresh,cv2.RETR_LIST,cv2.CHAIN_APPROX_SIMPLE)

for cnt in contours:
    if cv2.contourArea(cnt)>50:
        [x,y,w,h] = cv2.boundingRect(cnt)
        if  h>28:
            cv2.rectangle(im,(x,y),(x+w,y+h),(0,255,0),2)
            roi = thresh[y:y+h,x:x+w]
            roismall = cv2.resize(roi,(10,10))
            roismall = roismall.reshape((1,100))
            roismall = np.float32(roismall)
            retval, results, neigh_resp, dists = model.find_nearest(roismall, k = 1)
            string = str(int((results[0][0])))
            cv2.putText(out,string,(x,y+h),0,1,(0,255,0))

cv2.imshow('im',im)
cv2.imshow('out',out)
cv2.waitKey(0)

And it worked, below is the result I got:

enter image description here


Here it worked with 100% accuracy. I assume this is because all the digits are of the same kind and the same size.

But anyway, this is a good start to go for beginners (I hope so).

Best way to test exceptions with Assert to ensure they will be thrown

Suggest using NUnit's clean delegate syntax.

Example for testing ArgumentNullExeption:

[Test]
[TestCase(null)]
public void FooCalculation_InvalidInput_ShouldThrowArgumentNullExeption(string text)
{
    var foo = new Foo();
    Assert.That(() => foo.Calculate(text), Throws.ArgumentNullExeption);

    //Or:
    Assert.That(() => foo.Calculate(text), Throws.Exception.TypeOf<ArgumentNullExeption>);
}

Selenium WebDriver: Wait for complex page with JavaScript to load

I had a same issue. This solution works for me from WebDriverDoku:

WebDriverWait wait = new WebDriverWait(driver, 10);
WebElement element = wait.until(ExpectedConditions.elementToBeClickable(By.id("someid")));

http://www.seleniumhq.org/docs/04_webdriver_advanced.jsp

laravel collection to array

Use all() method - it's designed to return items of Collection:

/**
 * Get all of the items in the collection.
 *
 * @return array
 */
public function all()
{
    return $this->items;
}

Disabling browser print options (headers, footers, margins) from page?

Any recent version of Chrome and Opera, as well as Firefox 48 alpha 1 and greater

You can set the page margin to a size that's too small to contain the text in order to disable this (borrowing from awe's answer):

_x000D_
_x000D_
@page {
  size: auto;  /* auto is the initial value */
  margin: 0mm; /* this affects the margin in the printer settings */
}
html {
  background-color: #FFFFFF;
  margin: 0px; /* this affects the margin on the HTML before sending to printer */
}
body {
  border: solid 1px blue;
  margin: 10mm 15mm 10mm 15mm; /* margin you want for the content */
}
_x000D_
<ol>
  <li>
    <a href="data:,No Javascript :-(" target="_blank">Middle-click to open in new tab</a>
  </li>
  <li>
    <a href="javascript:print()">Print</a>
  </li>
</ol><!-- Hack to work around stack snippet restrictions --><script type=application/javascript>document.links[0].href="data:text/html;charset=utf-8,"+encodeURIComponent('<!doctype html>'+document.documentElement.outerHTML)</script>
_x000D_
_x000D_
_x000D_

For versions of Firefox up to 48 alpha 1

You can add a mozNoMarginBoxes attribute to the <html> tag to prevent the URL, page numbers and other things Firefox adds to the page margin from being printed.

It is working in Firefox 29 and onwards. You can see a screen shot of the difference here, or see here for a live example.

Note that the mozDisallowSelectionPrint attribute in the example is not required to remove the text from the margins; see What does the mozdisallowselectionprint attribute in PDF.js do?.

Other browsers

Unfortunately, there seems to be no way to resolve this problem in Internet Explorer, so you'll have to resort to PDF or ask users to disable margin texts.

The same goes for Safari; according to a comment by @Luiz Perez, the most recent versions of Safari (8, 9.1 and 10) still do not support @page for suppressing margin texts.

I can't find anything on Edge and I don't have a Windows 10 installation available to test.

What is for Python what 'explode' is for PHP?

Choose one you need:

>>> s = "Rajasekar SP  def"
>>> s.split(' ')
['Rajasekar', 'SP', '', 'def']
>>> s.split()
['Rajasekar', 'SP', 'def']
>>> s.partition(' ')
('Rajasekar', ' ', 'SP  def')

str.split and str.partition

How to display custom view in ActionBar?

There is a trick for this. All you have to do is to use RelativeLayout instead of LinearLayout as the main container. It's important to have android:layout_gravity="fill_horizontal" set for it. That should do it.

Checking if an object is a given type in Swift

In Swift 2.2 - 5 you can now do:

if object is String
{
}

Then to filter your array:

let filteredArray = originalArray.filter({ $0 is Array })

If you have multiple types to check:

    switch object
    {
    case is String:
        ...

    case is OtherClass:
        ...

    default:
        ...
    }

Django CSRF check failing with an Ajax POST request

Add this line to your jQuery code:

$.ajaxSetup({
  data: {csrfmiddlewaretoken: '{{ csrf_token }}' },
});

and done.

Slide right to left Android Animations

Right to left new page animation

<set xmlns:android="http://schemas.android.com/apk/res/android"
 android:shareInterpolator="false">
 <translate
    android:fromXDelta="0%" android:toXDelta="800%"
    android:fromYDelta="0%" android:toYDelta="0%"
    android:duration="600" />

What is the use of the %n format specifier in C?

%n is C99, works not with VC++.

How to access route, post, get etc. parameters in Zend Framework 2

The easisest way to get a posted json string, for example, is to read the contents of 'php://input' and then decode it. For example i had a simple Zend route:

'save-json' => array(
'type' => 'Zend\Mvc\Router\Http\Segment',
            'options' => array(
                'route'    => '/save-json/',
                'defaults' => array(
                    'controller' => 'CDB\Controller\Index',
                    'action'     => 'save-json',
                ),
            ),
        ),

and i wanted to post data to it using Angular's $http.post. The post was fine but the retrive method in Zend

$this->params()->fromPost('paramname'); 

didn't get anything in this case. So my solution was, after trying all kinds of methods like $_POST and the other methods stated above, to read from 'php://':

$content = file_get_contents('php://input');
print_r(json_decode($content));

I got my json array in the end. Hope this helps.

JavaScript Loading Screen while page loads

At the beginning of your loading script, just make your

visible through css [display:block;] and make the rest of the page invisible through css[display:none;].

Once the loading is done, just make the loading invisible and the page visible again with the same technique. You can use the document.getElementById() to select the divs you want to change the display.

Edit: Here's what it would sort of look like. When the body finishes loading, it will call the javascript function that will change the display values of the different elements. By default, your style would be to have the page not visible the loading visible.

<head>
    <style>
        #page{
            display: none;
        }
        #loading{
            display: block;
        }
    </style>
    <script>
        function myFunction()
        {
            document.getElementById("page").style.display = "block";
            document.getElementById("loading").style.display = "none";
        }
    </script>
</head>

<body onload="myFunction()">
    <div id="page">

    </div>
    <div id="loading">

    </div>
</body>

Remove row lines in twitter bootstrap

The other way around, if you have problems ADDING the lines to your panel dont forget to add the to your TABLE. By default (http://getbootstrap.com/components/#panels), it is suppose to add the line but It helped me to add the tag so now the row lines are shown.

The following example "probably" wont display the lines between rows:

<div class="panel panel-default">
    <!-- Default panel contents -->
    <div class="panel-heading">Panel heading</div>
    <!-- Table -->
    <table class="table">
        <tr><td> Hi 1! </td></tr>
        <tr><td> Hi 2! </td></tr>
    </table>
</div>

The following example WILL display the lines between rows:

<div class="panel panel-default">
    <!-- Default panel contents -->
    <div class="panel-heading">Panel heading</div>
    <!-- Table -->
    <table class="table">
        <thead></thead>
        <tr><td> Hi 1! </td></tr>
        <tr><td> Hi 2! </td></tr>
    </table>
</div>

UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 23: ordinal not in range(128)

I was getting this error when executing in python3,I got the same program working by simply executing in python2

Any way to limit border length?

The ::after pseudo-element rocks :)

If you play a bit you can even set your resized border element to appear centered or to appear only if there is another element next to it (like in menus). Here is an example with a menu:

#menu > ul > li {
    position: relative;
    float: left;
    padding: 0 10px;
}

#menu > ul > li + li::after {
    content:"";
    background: #ccc;
    position: absolute;
    bottom: 25%;
    left: 0;
    height: 50%;
    width: 1px;
}

_x000D_
_x000D_
#menu > ul > li {
  position: relative;
  float: left;
  padding: 0 10px;
  list-style: none;
}
#menu > ul > li + li::after {
  content: "";
  background: #ccc;
  position: absolute;
  bottom: 25%;
  left: 0;
  height: 50%;
  width: 1px;
}
_x000D_
<div id="menu">
  <ul>
    <li>Foo</li>
    <li>Bar</li>
    <li>Baz</li>
  </ul>
</div>
_x000D_
_x000D_
_x000D_

How to recursively download a folder via FTP on Linux

toggle the prompt by PROMPT command.

Usage:

ftp>cd /to/directory    
ftp>prompt    
ftp>mget  *

Whether a variable is undefined

jQuery.val() and .text() will never return 'undefined' for an empty selection. It always returns an empty string (i.e. ""). .html() will return null if the element doesn't exist though.You need to do:

if(page_name != '')

For other variables that don't come from something like jQuery.val() you would do this though:

if(typeof page_name != 'undefined')

You just have to use the typeof operator.

Calling @Html.Partial to display a partial view belonging to a different controller

As GvS said, but I also find it useful to use strongly typed views so that I can write something like

@Html.Partial(MVC.Student.Index(), model)

without magic strings.

Sizing elements to percentage of screen width/height

if you are using GridView you can use something like Ian Hickson's solution.

crossAxisCount: MediaQuery.of(context).size.width <= 400.0 ? 3 : MediaQuery.of(context).size.width >= 1000.0 ? 5 : 4

Adding custom radio buttons in android

Add a background drawable that references to an image, or a selector (like below), and make the button transparent:

<RadioButton
    android:id="@+id/radio0"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="@null"
    android:button="@drawable/yourbuttonbackground"
    android:checked="true"
    android:text="RadioButton1" />

If you would like your radio buttons to have a different resource when checked, create a selector background drawable:

res/drawable/yourbuttonbackground.xml

<selector xmlns:android="http://schemas.android.com/apk/res/android" >
    <item
        android:drawable="@drawable/b"
        android:state_checked="true"
        android:state_pressed="true" />
    <item
        android:drawable="@drawable/a"
        android:state_pressed="true" />
    <item
        android:drawable="@drawable/a"
        android:state_checked="true" />
    <item
        android:drawable="@drawable/b" />
</selector>

In the selector above, we reference two drawables, a and b, here's how we create them:

res/drawable/a.xml - Selected State

<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >
    <corners
        android:radius="5dp" />
    <solid
        android:color="#fff" />
    <stroke
        android:width="2dp"
        android:color="#53aade" />
</shape>

res/drawable/b.xml - Regular State

<shape
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle" >
    <corners
        android:radius="5dp" />
    <solid
        android:color="#fff" />
    <stroke
        android:width="2dp"
        android:color="#555555" />
</shape>

More on drawables here: http://developer.android.com/guide/topics/resources/drawable-resource.html

Difference between null and empty ("") Java String

What your statements are telling you is just that "" isn't the same as null - which is true. "" is an empty string; null means that no value has been assigned.

It might be more enlightening to try:

System.out.println(a.length()); // 0
System.out.println(b.length()); // error; b is not an object

"" is still a string, meaning you can call its methods and get meaningful information. null is an empty variable - there's literally nothing there.

How do I use System.getProperty("line.separator").toString()?

Try BufferedReader.readLine() instead of all this complication. It will recognize all possible line terminators.

TypeError: 'bool' object is not callable

Actually you can fix it with following steps -

  1. Do cls.__dict__
  2. This will give you dictionary format output which will contain {'isFilled':True} or {'isFilled':False} depending upon what you have set.
  3. Delete this entry - del cls.__dict__['isFilled']
  4. You will be able to call the method now.

In this case, we delete the entry which overrides the method as mentioned by BrenBarn.

SOAP-UI - How to pass xml inside parameter

To send CDATA in a request object use the SoapObject.setInnerText("..."); method.

How to post raw body data with curl?

curl's --data will by default send Content-Type: application/x-www-form-urlencoded in the request header. However, when using Postman's raw body mode, Postman sends Content-Type: text/plain in the request header.

So to achieve the same thing as Postman, specify -H "Content-Type: text/plain" for curl:

curl -X POST -H "Content-Type: text/plain" --data "this is raw data" http://78.41.xx.xx:7778/

Note that if you want to watch the full request sent by Postman, you can enable debugging for packed app. Check this link for all instructions. Then you can inspect the app (right-click in Postman) and view all requests sent from Postman in the network tab :

enter image description here

When does Git refresh the list of remote branches?

Use git fetch to fetch all latest created branches.

Omitting one Setter/Getter in Lombok

If you have setter and getter as private it will come up in PMD checks.

mssql convert varchar to float

DECLARE @INPUT VARCHAR(5) = '0.12',@INPUT_1 VARCHAR(5)='0.12x';
select CONVERT(float, @INPUT) YOUR_QUERY ,
case when isnumeric(@INPUT_1)=1 THEN CONVERT(float, @INPUT_1) ELSE 0 END AS YOUR_QUERY_ANSWERED

above will return values

however below query wont work

DECLARE @INPUT VARCHAR(5) = '0.12',@INPUT_1 VARCHAR(5)='0.12x';
select CONVERT(float, @INPUT) YOUR_QUERY ,
case when isnumeric(@INPUT_1)=1 THEN CONVERT(float, @INPUT_1) ELSE **@INPUT_1** END AS YOUR_QUERY_ANSWERED

as @INPUT_1 actually has varchar in it.

So your output column must have a varchar in it.

pop/remove items out of a python tuple

say you have a dict with tuples as keys, e.g: labels = {(1,2,0): 'label_1'} you can modify the elements of the tuple keys as follows:

formatted_labels = {(elem[0],elem[1]):labels[elem] for elem in labels}

Here, we ignore the last elements.

XSD - how to allow elements in any order any number of times?

In the schema you have in your question, child1 or child2 can appear in any order, any number of times. So this sounds like what you are looking for.

Edit: if you wanted only one of them to appear an unlimited number of times, the unbounded would have to go on the elements instead:

Edit: Fixed type in XML.

Edit: Capitalised O in maxOccurs

<xs:element name="foo">
   <xs:complexType>
     <xs:choice maxOccurs="unbounded">
       <xs:element name="child1" type="xs:int" maxOccurs="unbounded"/>
       <xs:element name="child2" type="xs:string" maxOccurs="unbounded"/>
     </xs:choice>
   </xs:complexType>
</xs:element>

If conditions in a Makefile, inside a target

You can simply use shell commands. If you want to suppress echoing the output, use the "@" sign. For example:

clean:
    @if [ "test" = "test" ]; then\
        echo "Hello world";\
    fi

Note that the closing ";" and "\" are necessary.

Get remote registry value

another option ... needs remoting ...

(invoke-command -ComputerName mymachine -ScriptBlock {Get-ItemProperty HKLM:\SOFTWARE\VanDyke\VShell\License -Name Version }).version

Ajax using https on an http page

Add the Access-Control-Allow-Origin header from the server

Access-Control-Allow-Origin: https://www.mysite.com

http://en.wikipedia.org/wiki/Cross-Origin_Resource_Sharing

What is mutex and semaphore in Java ? What is the main difference?

Semaphore can be counted, while mutex can only count to 1.

Suppose you have a thread running which accepts client connections. This thread can handle 10 clients simultaneously. Then each new client sets the semaphore until it reaches 10. When the Semaphore has 10 flags, then your thread won't accept new connections

Mutex are usually used for guarding stuff. Suppose your 10 clients can access multiple parts of the system. Then you can protect a part of the system with a mutex so when 1 client is connected to that sub-system, no one else should have access. You can use a Semaphore for this purpose too. A mutex is a "Mutual Exclusion Semaphore".

Add attribute 'checked' on click jquery

$( this ).attr( 'checked', 'checked' )

just attr( 'checked' ) will return the value of $( this )'s checked attribute. To set it, you need that second argument. Based on <input type="checkbox" checked="checked" />

Edit:

Based on comments, a more appropriate manipulation would be:

$( this ).attr( 'checked', true )

And a straight javascript method, more appropriate and efficient:

this.checked = true;

Thanks @Andy E for that.

JSON and escaping characters

This is SUPER late and probably not relevant anymore, but if anyone stumbles upon this answer, I believe I know the cause.

So the JSON encoded string is perfectly valid with the degree symbol in it, as the other answer mentions. The problem is most likely in the character encoding that you are reading/writing with. Depending on how you are using Gson, you are probably passing it a java.io.Reader instance. Any time you are creating a Reader from an InputStream, you need to specify the character encoding, or java.nio.charset.Charset instance (it's usually best to use java.nio.charset.StandardCharsets.UTF_8). If you don't specify a Charset, Java will use your platform default encoding, which on Windows is usually CP-1252.

How to send an HTTP request using Telnet

To somewhat expand on earlier answers, there are a few complications.

telnet is not particularly scriptable; you might prefer to use nc (aka netcat) instead, which handles non-terminal input and signals better.

Also, unlike telnet, nc actually allows SSL (and so https instead of http traffic -- you need port 443 instead of port 80 then).

There is a difference between HTTP 1.0 and 1.1. The recent version of the protocol requires the Host: header to be included in the request on a separate line after the POST or GET line, and to be followed by an empty line to mark the end of the request headers.

The HTTP protocol requires carriage return / line feed line endings. Many servers are lenient about this, but some are not. You might want to use

printf "%\r\n" \
    "GET /questions HTTP/1.1" \
    "Host: stackoverflow.com" \
    "" |
nc --ssl stackoverflow.com 443

If you fall back to HTTP/1.0 you don't always need the Host: header, but many modern servers require the header anyway; if multiple sites are hosted on the same IP address, the server doesn't know from GET /foo HTTP/1.0 whether you mean http://site1.example.com/foo or http://site2.example.net/foo if those two sites are both hosted on the same server (in the absence of a Host: header, a HTTP 1.0 server might just default to a different site than the one you want, so you don't get the contents you wanted).

The HTTPS protocol is identical to HTTP in these details; the only real difference is in how the session is set up initially.

gem install: Failed to build gem native extension (can't find header files)

For those that are still experiencing problems, like I have(I am using Ubuntu 16.04), I had to put in the following commands in order to get some gems like bcrypt, pg, and others installed. They are all similar to the ones above except for one.

sudo apt-get install ruby-dev -y
sudo apt-get install libpq-dev -y
sudo apt-get install libmysqlclient-dev
sudo apt-get install build-essential patch -y

This allowed me to install gems like, PG, bcrypt, and recaptcha.

How do I install a NuGet package .nupkg file locally?

For .nupkg files I like to use:

Install-Package C:\Path\To\Some\File.nupkg

Angular - Set headers for every request

After some investigation, I found the final and the most easy way is to extend BaseRequestOptions which I prefer.
The following are the ways I tried and give up for some reason:
1. extend BaseRequestOptions, and add dynamic headers in constructor(). It can not work if I login. It will be created once. So it is not dynamic.
2. extend Http. Same reason as above, I can not add dynamic headers in constructor(). And if I rewrite request(..) method, and set headers, like this:

request(url: string|Request, options?: RequestOptionsArgs): Observable<Response> {
 let token = localStorage.getItem(AppConstants.tokenName);
 if (typeof url === 'string') { // meaning we have to add the token to the options, not in url
  if (!options) {
    options = new RequestOptions({});
  }
  options.headers.set('Authorization', 'token_value');
 } else {
  url.headers.set('Authorization', 'token_value');
 }
 return super.request(url, options).catch(this.catchAuthError(this));
}

You just need to overwrite this method, but not every get/post/put methods.

3.And my preferred solution is extend BaseRequestOptions and overwrite merge() :

@Injectable()
export class AuthRequestOptions extends BaseRequestOptions {

 merge(options?: RequestOptionsArgs): RequestOptions {
  var newOptions = super.merge(options);
  let token = localStorage.getItem(AppConstants.tokenName);
  newOptions.headers.set(AppConstants.authHeaderName, token);
  return newOptions;
 }
}

this merge() function will be called for every request.

How to get all checked checkboxes

In IE9+, Chrome or Firefox you can do:

var checkedBoxes = document.querySelectorAll('input[name=mycheckboxes]:checked');

How do I get the last character of a string using an Excel function?

Just another way to do this:

=MID(A1, LEN(A1), 1)

How to create a horizontal loading progress bar?

Just add a STYLE line and your progress becomes horizontal:

<ProgressBar
        style="?android:attr/progressBarStyleHorizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/progress"
        android:layout_centerHorizontal="true"      
        android:layout_centerVertical="true"      
        android:max="100" 
        android:progress="45"/>

Bootstrap 3 2-column form layout

You can use the bootstrap grid system. as Yoann said


 <div class="container">
    <div class="row">
        <form role="form">
           <div class="form-group col-xs-10 col-sm-4 col-md-4 col-lg-4">
                        <label for="exampleInputEmail1">Email address</label>
                        <input type="email" class="form-control" id="exampleInputEmail1" placeholder="Enter email">
                    </div>
                    <div class="form-group col-xs-10 col-sm-4 col-md-4 col-lg-4">
                        <label for="exampleInputEmail1">Name</label>
                        <input type="text" class="form-control" id="exampleInputEmail1" placeholder="Enter Name">
                    </div>
                    <div class="clearfix"></div>
                    <div class="form-group col-xs-10 col-sm-4 col-md-4 col-lg-4">
                        <label for="exampleInputPassword1">Password</label>
                        <input type="password" class="form-control" id="exampleInputPassword1" placeholder="Password">
                    </div>
                    <div class="form-group col-xs-10 col-sm-4 col-md-4 col-lg-4">
                        <label for="exampleInputPassword1">Confirm Password</label>
                        <input type="password" class="form-control" id="exampleInputPassword1" placeholder="Confirm Password">
                    </div>
          </form>
         <div class="clearfix">
      </div>
    </div>
</div>

SQL LEFT-JOIN on 2 fields for MySQL

Let's try this way:

select 
    a.ip, 
    a.os, 
    a.hostname, 
    a.port, 
    a.protocol, 
    b.state
from a
left join b 
    on a.ip = b.ip 
        and a.port = b.port /*if you has to filter by columns from right table , then add this condition in ON clause*/
where a.somecolumn = somevalue /*if you have to filter by some column from left table, then add it to where condition*/

So, in where clause you can filter result set by column from right table only on this way:

...
where b.somecolumn <> (=) null

Detect changes in the DOM

or you can simply Create your own event, that run everywhere

 $("body").on("domChanged", function () {
                //dom is changed 
            });


 $(".button").click(function () {

          //do some change
          $("button").append("<span>i am the new change</span>");

          //fire event
          $("body").trigger("domChanged");

        });

Full example http://jsfiddle.net/hbmaam/Mq7NX/

Spring Security redirect to previous page after successful login

I've custom OAuth2 authorization and request.getHeader("Referer") is not available at poit of decision. But security request already saved in ExceptionTranslationFilter.sendStartAuthentication:

protected void sendStartAuthentication(HttpServletRequest request,...
    ...
    requestCache.saveRequest(request, response);

So, all what we need is share requestCache as Spring bean:

@Bean
public RequestCache requestCache() {
   return new HttpSessionRequestCache();
}

@Override
protected void configure(HttpSecurity http) throws Exception {
   http.authorizeRequests()
   ... 
   .requestCache().requestCache(requestCache()).and()
   ...
}     

and use it wheen authorization is finished:

@Autowired
private RequestCache requestCache;

public void authenticate(HttpServletRequest req, HttpServletResponse resp){
    ....
    SavedRequest savedRequest = requestCache.getRequest(req, resp);
    resp.sendRedirect(savedRequest != null && "GET".equals(savedRequest.getMethod()) ?  
    savedRequest.getRedirectUrl() : "defaultURL");
}

Escape Character in SQL Server

You need to just replace ' with '' inside your string

SELECT colA, colB, colC
FROM tableD
WHERE colA = 'John''s Mobile'

You can also use REPLACE(@name, '''', '''''') if generating the SQL dynamically

If you want to escape inside a like statement then you need to use the ESCAPE syntax

It's also worth mentioning that you're leaving yourself open to SQL injection attacks if you don't consider it. More info at Google or: http://it.toolbox.com/wiki/index.php/How_do_I_escape_single_quotes_in_SQL_queries%3F

The difference in months between dates in MySQL

The Query will be like:

select period_diff(date_format(now(),"%Y%m"),date_format(created,"%Y%m")) from customers where..

Gives a number of calendar months since the created datestamp on a customer record, letting MySQL do the month selection internally.

What's the safest way to iterate through the keys of a Perl hash?

I always use method 2 as well. The only benefit of using each is if you're just reading (rather than re-assigning) the value of the hash entry, you're not constantly de-referencing the hash.

What does the construct x = x || y mean?

And I have to add one more thing: This bit of shorthand is an abomination. It misuses an accidental interpreter optimization (not bothering with the second operation if the first is truthy) to control an assignment. That use has nothing to do with the purpose of the operator. I do not believe it should ever be used.

I prefer the ternary operator for initialization, eg,

var title = title?title:'Error';

This uses a one-line conditional operation for its correct purpose. It still plays unsightly games with truthiness but, that's Javascript for you.

How to move an element into another element?

If the div where you want to put your element has content inside, and you want the element to show after the main content:

  $("#destination").append($("#source"));

If the div where you want to put your element has content inside, and you want to show the element before the main content:

$("#destination").prepend($("#source"));

If the div where you want to put your element is empty, or you want to replace it entirely:

$("#element").html('<div id="source">...</div>');

If you want to duplicate an element before any of the above:

$("#destination").append($("#source").clone());
// etc.

What's the difference between an Angular component and module

enter image description here

Simplest Explanation:

Module is like a big container containing one or many small containers called Component, Service, Pipe

A Component contains :

  • HTML template or HTML code

  • Code(TypeScript)

  • Service: It is a reusable code that is shared by the Components so that rewriting of code is not required

  • Pipe: It takes in data as input and transforms it to the desired output

Reference: https://scrimba.com/

Running a shell script through Cygwin on Windows

If you don't mind always including .sh on the script file name, then you can keep the same script for Cygwin and Unix (Macbook).

To illustrate:
1. Always include .sh to your script file name, e.g., test1.sh
2. test1.sh looks like the following as an example:
#!/bin/bash echo '$0 = ' $0 echo '$1 = ' $1 filepath=$1 3. On Windows with Cygwin, you type "test1.sh" to run
4. On a Unix, you also type "test1.sh" to run


Note: On Windows, you need to use the file explorer to do following once:
1. Open the file explorer
2. Right-click on a file with .sh extension, like test1.sh
3. Open with... -> Select sh.exe
After this, your Windows 10 remembers to execute all .sh files with sh.exe.

Note: Using this method, you do not need to prepend your script file name with bash to run

MySQL Multiple Left Joins

To display the all details for each news post title ie. "news.id" which is the primary key, you need to use GROUP BY clause for "news.id"

SELECT news.id, users.username, news.title, news.date,
       news.body, COUNT(comments.id)
FROM news
LEFT JOIN users
ON news.user_id = users.id
LEFT JOIN comments
ON comments.news_id = news.id
GROUP BY news.id

What is an example of the Liskov Substitution Principle?

The LSP is a rule about the contract of the clases: if a base class satisfies a contract, then by the LSP derived classes must also satisfy that contract.

In Pseudo-python

class Base:
   def Foo(self, arg): 
       # *... do stuff*

class Derived(Base):
   def Foo(self, arg):
       # *... do stuff*

satisfies LSP if every time you call Foo on a Derived object, it gives exactly the same results as calling Foo on a Base object, as long as arg is the same.

NoClassDefFoundError while trying to run my jar with java.exe -jar...what's wrong?

The -jar option is mutually exclusive of -classpath. See an old description here

-jar

Execute a program encapsulated in a JAR file. The first argument is the name of a JAR file instead of a startup class name. In order for this option to work, the manifest of the JAR file must contain a line of the form Main-Class: classname. Here, classname identifies the class having the public static void main(String[] args) method that serves as your application's starting point.

See the Jar tool reference page and the Jar trail of the Java Tutorial for information about working with Jar files and Jar-file manifests.

When you use this option, the JAR file is the source of all user classes, and other user class path settings are ignored.

A quick and dirty hack is to append your classpath to the bootstrap classpath:

-Xbootclasspath/a:path

Specify a colon-separated path of directires, JAR archives, and ZIP archives to append to the default bootstrap class path.

However, as @Dan rightly says, the correct solution is to ensure your JARs Manifest contains the classpath for all JARs it will need.

jQuery if statement to check visibility

 $('#column-left form').hide();
 $('.show-search').click(function() {
    $('#column-left form').stop(true, true).slideToggle(300); //this will slide but not hide that's why
    $('#column-left form').hide(); 
    if(!($('#column-left form').is(":visible"))) {
        $("#offers").show();
    } else {
        $('#offers').hide();
    }
  });

How is Docker different from a virtual machine?

There are three different setups that providing a stack to run an application on (This will help us to recognize what a container is and what makes it so much powerful than other solutions):

1) Traditional Servers(bare metal)
2) Virtual machines (VMs)
3) Containers

1) Traditional server stack consist of a physical server that runs an operating system and your application.

Advantages:

  • Utilization of raw resources

  • Isolation

Disadvantages:

  • Very slow deployment time
  • Expensive
  • Wasted resources
  • Difficult to scale
  • Difficult to migrate
  • Complex configuration

2) The VM stack consist of a physical server which runs an operating system and a hypervisor that manages your virtual machine, shared resources, and networking interface. Each Vm runs a Guest Operating System, an application or set of applications.

Advantages:

  • Good use of resources
  • Easy to scale
  • Easy to backup and migrate
  • Cost efficiency
  • Flexibility

Disadvantages:

  • Resource allocation is problematic
  • Vendor lockin
  • Complex configuration

3) The Container Setup, the key difference with other stack is container-based virtualization uses the kernel of the host OS to rum multiple isolated guest instances. These guest instances are called as containers. The host can be either a physical server or VM.

Advantages:

  • Isolation
  • Lightweight
  • Resource effective
  • Easy to migrate
  • Security
  • Low overhead
  • Mirror production and development environment

Disadvantages:

  • Same Architecture
  • Resource heavy apps
  • Networking and security issues.

By comparing the container setup with its predecessors, we can conclude that containerization is the fastest, most resource effective, and most secure setup we know to date. Containers are isolated instances that run your application. Docker spin up the container in a way, layers get run time memory with default storage drivers(Overlay drivers) those run within seconds and copy-on-write layer created on top of it once we commit into the container, that powers the execution of containers. In case of VM's that will take around a minute to load everything into the virtualize environment. These lightweight instances can be replaced, rebuild, and moved around easily. This allows us to mirror the production and development environment and is tremendous help in CI/CD processes. The advantages containers can provide are so compelling that they're definitely here to stay.

How do I specify new lines on Python, when writing on files?

In Python you can just use the new-line character, i.e. \n

Android Endless List

Best solution so far that I have seen is in FastAdapter library for recycler views. It has a EndlessRecyclerOnScrollListener.

Here is an example usage: EndlessScrollListActivity

Once I used it for endless scrolling list I have realised that the setup is a very robust. I'd definitely recommend it.

What is a Windows Handle?

A handle is a unique identifier for an object managed by Windows. It's like a pointer, but not a pointer in the sence that it's not an address that could be dereferenced by user code to gain access to some data. Instead a handle is to be passed to a set of functions that can perform actions on the object the handle identifies.

Fill SVG path element with a background-image

You can do it by making the background into a pattern:

<defs>
  <pattern id="img1" patternUnits="userSpaceOnUse" width="100" height="100">
    <image href="wall.jpg" x="0" y="0" width="100" height="100" />
  </pattern>
</defs>

Adjust the width and height according to your image, then reference it from the path like this:

<path d="M5,50
         l0,100 l100,0 l0,-100 l-100,0
         M215,100
         a50,50 0 1 1 -100,0 50,50 0 1 1 100,0
         M265,50
         l50,100 l-100,0 l50,-100
         z"
  fill="url(#img1)" />

Working example

How to make an empty div take space

If they need to be floated, you could always just set the min-height to 1px so they don't collapse.

How do I use StringUtils in Java?

StringUtils is in org.apache.commons.lang.* not in java.lang.*. Most importantly learn to read javadoc file. All java programmers after learning basic java learn to read javadoc, execute tests from public projects, use those jars in their projects.

If you are working on eclipse or netbeans you can make a directory (folder) called lib in your project (from within the IDE) and copy the downloaded jar from hard disk and paste it in that directory from eclipse or netbeans. Next you have to add it to your project.

E.g in case of eclipse from Project->Properties select Java Build Path -> Add Jars, point to the jar you copied earlier. In your case it might be commons-lang-version.jar.

After this step whenever you add above import in a java file, those libraries will be available on your project (in case of eclipse or netbeans).

From where do you get the jar for commons-lang? Root directory of any apache commons is http://commons.apache.org/ And for commons-lang it is http://commons.apache.org/lang/

Some of these libraries contain User Guide and other help to get you started, but javadoc is the ultimate guide for any java programmer.

It is right time you asked about this library, because you should never re-invent the wheel. Use apache commons and other well tested libraries whenever possible. By using those libraries you omit some common human errors and even test those libraries (using is testing). Sometimes in future when using this library, you may even write some modifications or addition to this library. If you contribute back, the world benefits.

Most common use of StringUtils is in web projects (when you want to check for blank or null strings, checking if a string is number, splitting strings with some token). StringUtils helps to get rid of those nasty NumberFormat and Null exceptions. But StringUtils can be used anywhere String is used.

how to calculate percentage in python

You're performing an integer division. Append a .0 to the number literals:

per=float(tota)*(100.0/500.0)

In Python 2.7 the division 100/500==0.

As pointed out by @unwind, the float() call is superfluous since a multiplication/division by a float returns a float:

per= tota*100.0 / 500

Converting a datetime string to timestamp in Javascript

For those of us using non-ISO standard date formats, like civilian vernacular 01/01/2001 (mm/dd/YYYY), including time in a 12hour date format with am/pm marks, the following function will return a valid Date object:

function convertDate(date) {

    // # valid js Date and time object format (YYYY-MM-DDTHH:MM:SS)
    var dateTimeParts = date.split(' ');

    // # this assumes time format has NO SPACE between time and am/pm marks.
    if (dateTimeParts[1].indexOf(' ') == -1 && dateTimeParts[2] === undefined) {

        var theTime = dateTimeParts[1];

        // # strip out all except numbers and colon
        var ampm = theTime.replace(/[0-9:]/g, '');

        // # strip out all except letters (for AM/PM)
        var time = theTime.replace(/[[^a-zA-Z]/g, '');

        if (ampm == 'pm') {

            time = time.split(':');

            // # if time is 12:00, don't add 12
            if (time[0] == 12) {
                time = parseInt(time[0]) + ':' + time[1] + ':00';
            } else {
                time = parseInt(time[0]) + 12 + ':' + time[1] + ':00';
            }

        } else { // if AM

            time = time.split(':');

            // # if AM is less than 10 o'clock, add leading zero
            if (time[0] < 10) {
                time = '0' + time[0] + ':' + time[1] + ':00';
            } else {
                time = time[0] + ':' + time[1] + ':00';
            }
        }
    }
    // # create a new date object from only the date part
    var dateObj = new Date(dateTimeParts[0]);

    // # add leading zero to date of the month if less than 10
    var dayOfMonth = (dateObj.getDate() < 10 ? ("0" + dateObj.getDate()) : dateObj.getDate());

    // # parse each date object part and put all parts together
    var yearMoDay = dateObj.getFullYear() + '-' + (dateObj.getMonth() + 1) + '-' + dayOfMonth;

    // # finally combine re-formatted date and re-formatted time!
    var date = new Date(yearMoDay + 'T' + time);

    return date;
}

Usage:

date = convertDate('11/15/2016 2:00pm');

How to fix the error; 'Error: Bootstrap tooltips require Tether (http://github.hubspot.com/tether/)'

An additional note. If you check uncompressed javascript file, you will find the condition:

if(window.Tether === undefined) {
     throw new Error('Bootstrap tooltips require Tether (http://github.hubspot.com/tether)')
}

So the error message contains the required information.

You can download the archive from that link.

Uncompressed version:

https://rawgit.com/HubSpot/tether/master/src/js/tether.js https://rawgit.com/HubSpot/tether/master/dist/css/tether.css

Calling Objective-C method from C++ member function?

Also, you can call into Objective-C runtime to call the method.

Automatically get loop index in foreach loop in Perl

Please consider:

print "Element at index $_ is $x[$_]\n" for keys @x;

How to check if input file is empty in jQuery

  $("#customFile").change(function() { 
    var fileName = $("#customFile").val();  

    if(fileName) { // returns true if the string is not empty   
        $('.picture-selected').addClass('disable-inputs'); 
        $('#btn').removeClass('disabled');   
    } else { // no file was selected 
      $('.picture-selected').removeClass('disable-inputs'); 
      $('#btn').addClass('disabled');
    }  
  });

How do I put a border around an Android textview?

You can set the border by two methods. One is by drawable and the second is programmatic.

Using Drawable

<shape>
    <solid android:color="@color/txt_white"/>
    <stroke android:width="1dip" android:color="@color/border_gray"/>
    <corners android:bottomLeftRadius="10dp"
             android:bottomRightRadius="0dp"
             android:topLeftRadius="10dp"
             android:topRightRadius="0dp"/>
    <padding android:bottom="0dip"
             android:left="0dip"
             android:right="0dip"
             android:top="0dip"/>
</shape>

Programmatic


public static GradientDrawable backgroundWithoutBorder(int color) {

    GradientDrawable gdDefault = new GradientDrawable();
    gdDefault.setColor(color);
    gdDefault.setCornerRadii(new float[] { radius, radius, 0, 0, 0, 0,
                                           radius, radius });
    return gdDefault;
}

Why are unnamed namespaces used and what are their benefits?

Having something in an anonymous namespace means it's local to this translation unit (.cpp file and all its includes) this means that if another symbol with the same name is defined elsewhere there will not be a violation of the One Definition Rule (ODR).

This is the same as the C way of having a static global variable or static function but it can be used for class definitions as well (and should be used rather than static in C++).

All anonymous namespaces in the same file are treated as the same namespace and all anonymous namespaces in different files are distinct. An anonymous namespace is the equivalent of:

namespace __unique_compiler_generated_identifer0x42 {
    ...
}
using namespace __unique_compiler_generated_identifer0x42;

Get today date in google appScript

function myFunction() {
  var sheetname = "DateEntry";//Sheet where you want to put the date
  var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName(sheetname);
    // You could use now Date(); on its own but it will not look nice.
  var date = Utilities.formatDate(new Date(), "GMT+5:30", "yyyy-MM-dd");
    //var endDate = date;
    sheet.getRange(sheet.getLastRow() + 1,1).setValue(date); //Gets the last row which had value, and goes to the next empty row to put new values.
}

Insert variable into Header Location PHP

You can add it like this

header('Location: http://linkhere.com/'.$url_endpoint);

smtpclient " failure sending mail"

Five years later (I hope this developer isn't still waiting for a fix to this..)

I had the same issue, caused by the same error: I was declaring the SmtpClient inside the loop.

The fix is simple - declare it once, outside the loop...

MailAddress mail = null;
SmtpClient client = new SmtpClient();
client.Port = 25;
client.EnableSsl = false;
client.DeliveryMethod = SmtpDeliveryMethod.Network;
client.UseDefaultCredentials = true;
client.Host = smtpAddress;       //  Enter your company's email server here!

for(int i = 0; i < number ; i++)
{
    mail = new MailMessage(iMail.from, iMail.to);
    mail.Subject = iMail.sub;
    mail.Body = iMail.body;
    mail.IsBodyHtml = true;
    mail.Priority = MailPriority.Normal;
    mail.Sender = from;
    client.Send(mail);
}
mail.Dispose();
client.Dispose();

RegEx: How can I match all numbers greater than 49?

Next matches all greater or equal to 11100:

^([1-9][1-9][1-9]\d{2}\d*|[1-9][2-9]\d{3}\d*|[2-9]\d{4}\d*|\d{6}\d*)$

For greater or equal 50:

^([5-9]\d{1}\d*|\d{3}\d*)$

See pattern and modify to any number. Also it would be great to find some recursive forward/backward operators for large numbers.

git - Your branch is ahead of 'origin/master' by 1 commit

I resolved this by just running a simple:

git pull

Nothing more. Now it's showing:

# On branch master
nothing to commit, working directory clean

Error in MySQL when setting default value for DATE or DATETIME

set global sql_mode = 'STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION';

FileSystemWatcher Changed event is raised twice

I approached the double create issue like this, which ignores the first event:

Private WithEvents fsw As New System.IO.FileSystemWatcher
Private complete As New List(Of String)

Private Sub fsw_Created(ByVal sender As Object, _
    ByVal e As System.IO.FileSystemEventArgs) Handles fsw.Created

    If Not complete.Contains(e.FullPath) Then
        complete.Add(e.FullPath)

    Else
        complete.Remove(e.FullPath)
        Dim th As New Threading.Thread(AddressOf hprocess)
        th.Start(e)

    End If

End Sub

Bootstrap collapse animation not smooth

For others like me who had a different but similar issue where the animation was not occurring at all:

From what I could find it may be something in my browser setting which preferred less motion for accessibility purposes. I could not find any setting in my browser, but I was able to get the animation working by downloading a local copy of bootstrap and commenting out this section of the CSS file:

@media (prefers-reduced-motion: reduce) {
  .collapsing {
    -webkit-transition: none;
    transition: none;
  }
}

Is it possible to get only the first character of a String?

Java strings are simply an array of char. So, char c = s[0] where s is string.

How does a hash table work?

This turns out to be a pretty deep area of theory, but the basic outline is simple.

Essentially, a hash function is just a function that takes things from one space (say strings of arbitrary length) and maps them to a space useful for indexing (unsigned integers, say).

If you only have a small space of things to hash, you might get away with just interpreting those things as integers, and you're done (e.g. 4 byte strings)

Usually, though, you've got a much larger space. If the space of things you allow as keys is bigger than the space of things you are using to index (your uint32's or whatever) then you can't possibly have a unique value for each one. When two or more things hash to the same result, you'll have to handle the redundancy in an appropriate way (this is usually referred to as a collision, and how you handle it or don't will depend a bit on what you are using the hash for).

This implies you want it to be unlikely to have the same result, and you probably also would really like the hash function to be fast.

Balancing these two properties (and a few others) has kept many people busy!

In practice you usually should be able to find a function that is known to work well for your application and use that.

Now to make this work as a hashtable: Imagine you didn't care about memory usage. Then you can create an array as long as your indexing set (all uint32's, for example). As you add something to the table, you hash it's key and look at the array at that index. If there is nothing there, you put your value there. If there is already something there, you add this new entry to a list of things at that address, along with enough information (your original key, or something clever) to find which entry actually belongs to which key.

So as you go a long, every entry in your hashtable (the array) is either empty, or contains one entry, or a list of entries. Retrieving is a simple as indexing into the array, and either returning the value, or walking the list of values and returning the right one.

Of course in practice you typically can't do this, it wastes too much memory. So you do everything based on a sparse array (where the only entries are the ones you actually use, everything else is implicitly null).

There are lots of schemes and tricks to make this work better, but that's the basics.

Hexadecimal value 0x00 is a invalid character

I'm using IronPython here (same as .NET API) and reading the file as UTF-8 in order to properly handle the BOM fixed the problem for me:

xmlFile = Path.Combine(directory_str, 'file.xml')
doc = XPathDocument(XmlTextReader(StreamReader(xmlFile.ToString(), Encoding.UTF8)))

It would work as well with the XmlDocument:

doc = XmlDocument()
doc.Load(XmlTextReader(StreamReader(xmlFile.ToString(), Encoding.UTF8)))

"Could not find acceptable representation" using spring-boot-starter-web

I had to explicitly call out the dependency for my json library in my POM.

Once I added the below dependency, it all worked.

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
</dependency>

Why does make think the target is up to date?

my mistake was making the target name "filename.c:" instead of just "filename:"

how to open an URL in Swift3

Above answer is correct but if you want to check you canOpenUrl or not try like this.

let url = URL(string: "http://www.facebook.com")!
if UIApplication.shared.canOpenURL(url) {
    UIApplication.shared.open(url, options: [:], completionHandler: nil)
    //If you want handle the completion block than 
    UIApplication.shared.open(url, options: [:], completionHandler: { (success) in
         print("Open url : \(success)")
    })
}

Note: If you do not want to handle completion you can also write like this.

UIApplication.shared.open(url, options: [:])

No need to write completionHandler as it contains default value nil, check apple documentation for more detail.

MVC 4 Razor adding input type date

You will get it by tag type="date"...then it will render beautiful calendar and all...

@Html.TextBoxFor(model => model.EndTime, new { type = "date" })

What is the fastest way to send 100,000 HTTP requests in Python?

This twisted async web client goes pretty fast.

#!/usr/bin/python2.7

from twisted.internet import reactor
from twisted.internet.defer import Deferred, DeferredList, DeferredLock
from twisted.internet.defer import inlineCallbacks
from twisted.web.client import Agent, HTTPConnectionPool
from twisted.web.http_headers import Headers
from pprint import pprint
from collections import defaultdict
from urlparse import urlparse
from random import randrange
import fileinput

pool = HTTPConnectionPool(reactor)
pool.maxPersistentPerHost = 16
agent = Agent(reactor, pool)
locks = defaultdict(DeferredLock)
codes = {}

def getLock(url, simultaneous = 1):
    return locks[urlparse(url).netloc, randrange(simultaneous)]

@inlineCallbacks
def getMapping(url):
    # Limit ourselves to 4 simultaneous connections per host
    # Tweak this number, but it should be no larger than pool.maxPersistentPerHost 
    lock = getLock(url,4)
    yield lock.acquire()
    try:
        resp = yield agent.request('HEAD', url)
        codes[url] = resp.code
    except Exception as e:
        codes[url] = str(e)
    finally:
        lock.release()


dl = DeferredList(getMapping(url.strip()) for url in fileinput.input())
dl.addCallback(lambda _: reactor.stop())

reactor.run()
pprint(codes)

How to hide html source & disable right click and text copy?

You potentially can not prevent user from viewing the HTML source content. The site that you have listed prevents user from right click. but fact is you can still do CTRL + U in Firefox to view source!

How to generate a git patch for a specific commit?

Say you have commit id 2 after commit 1 you would be able to run:

git diff 2 1 > mypatch.diff

where 2 and 1 are SHA hashes.

How do I redirect to another webpage?

Use:

function redirect(a) {
    location = a
}

And call it with: redirect([url]);

There's no need for the href after location, as it is implied.

How to get the fields in an Object via reflection?

I've an object (basically a VO) in Java and I don't know its type. I need to get values which are not null in that object.

Maybe you don't necessary need reflection for that -- here is a plain OO design that might solve your problem:

  1. Add an interface Validation which expose a method validate which checks the fields and return whatever is appropriate.
  2. Implement the interface and the method for all VO.
  3. When you get a VO, even if it's concrete type is unknown, you can typecast it to Validation and check that easily.

I guess that you need the field that are null to display an error message in a generic way, so that should be enough. Let me know if this doesn't work for you for some reason.

setting an environment variable in virtualenv

Locally within an virtualenv there are two methods you could use to test this. The first is a tool which is installed via the Heroku toolbelt (https://toolbelt.heroku.com/). The tool is foreman. It will export all of your environment variables that are stored in a .env file locally and then run app processes within your Procfile.

The second way if you're looking for a lighter approach is to have a .env file locally then run:

export $(cat .env)

Bootstrap 3 with remote Modal

For Bootstrap 3

The workflow I had to deal with was loading content with a url context that could change. So by default setup your modal with javascript or the href for the default context you want to show :

$('#myModal').modal({
        show: false,
        remote: 'some/context'
});

Destroying the modal wouldn't work for me because I wasn't loading from the same remote, thus I had to :

$(".some-action-class").on('click', function () {
        $('#myModal').removeData('bs.modal');
        $('#myModal').modal({remote: 'some/new/context?p=' + $(this).attr('buttonAttr') });
        $('#myModal').modal('show');
});

This of course was easily refactored into a js library and gives you a lot of flexibility with loading modals

I hope this saves someone 15 minutes of tinkering.

What is @ModelAttribute in Spring MVC?

I know I am late to the party, but I'll quote like they say, "better be late than never". So let us get going, Everybody has their own ways to explain things, let me try to sum it up and simple it up for you in a few steps with an example; Suppose you have a simple form, form.jsp

<form:form action="processForm" modelAttribute="student">
First Name : <form:input path="firstName" /> 
<br><br>
Last Name : <form:input path="lastName" />
<br><br>
<input type="submit" value="submit"/>
</form:form>

path="firstName" path="lastName" These are the fields/properties in the StudentClass when the form is called their getters are called but once submitted their setters are called and their values are set in the bean that was indicated in the modelAttribute="student" in the form tag.

We have StudentController that includes the following methods;

@RequestMapping("/showForm")
public String showForm(Model theModel){ //Model is used to pass data between 
//controllers and views
    theModel.addAttribute("student", new Student()); //attribute name, value
return "form";
}

@RequestMapping("/processForm")
public String processForm(@ModelAttribute("student") Student theStudent){
    System.out.println("theStudent :"+ theStudent.getLastName());
return "form-details";
}

//@ModelAttribute("student") Student theStudent
//Spring automatically populates the object data with form data all behind the 
//scenes 

now finally we have a form-details.jsp

<b>Student Information</b>
${student.firstName}
${student.lastName}

So back to the question What is @ModelAttribute in Spring MVC? A sample definition from the source for you, http://www.baeldung.com/spring-mvc-and-the-modelattribute-annotation The @ModelAttribute is an annotation that binds a method parameter or method return value to a named model attribute and then exposes it to a web view.

What actually happens is it gets all the values of your form those were submitted by it and then holds them for you to bind or assign them to the object. It works same like the @RequestParameter where we only get a parameter and assign the value to some field. Only difference is @ModelAttribute holds all form data rather than a single parameter. It creates a bean for you that holds form submitted data to be used by the developer later on.

To recap the whole thing. Step 1 : A request is sent and our method showForm runs and a model, a temporary bean is set with the name student is forwarded to the form. theModel.addAttribute("student", new Student());

Step 2 : modelAttribute="student" on form submission model changes the student and now it holds all parameters of the form

Step 3 : @ModelAttribute("student") Student theStudent We fetch the values being hold by @ModelAttribute and assign the whole bean/object to Student.

Step 4 : And then we use it as we bid, just like showing it on the page etc like I did

I hope it helps you to understand the concept. Thanks

How to convert an integer to a string in any base?

def baseConverter(x, b):
    s = ""
    d = string.printable.upper()
    while x > 0:
        s += d[x%b]
        x = x / b
    return s[::-1]

How to add a button dynamically using jquery

the $("body").append(r) statement should be within the test function, also there was misplaced " in the test method

function test() {
    var r=$('<input/>').attr({
        type: "button",
        id: "field",
        value: 'new'
    });
    $("body").append(r);    
}

Demo: Fiddle

Update
In that case try a more jQuery-ish solution

<!DOCTYPE html>
<html>
    <head>
        <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
        <script type="text/javascript">
          jQuery(function($){
              $('#mybutton').one('click', function(){
                  var r=$('<input/>').attr({
                      type: "button",
                      id: "field",
                      value: 'new'
                  });
                  $("body").append(r);   
              })
          })
        </script>
    </head>
    <body>
        <button id="mybutton">Insert after</button> 
    </body>
</html>

Demo: Plunker

Duplicate / Copy records in the same MySQL table

Your approach is good but the problem is that you use "*" instead enlisting fields names. If you put all the columns names excep primary key your script will work like charm on one or many records.

INSERT INTO invoices (iv.field_name, iv.field_name,iv.field_name
) SELECT iv.field_name, iv.field_name,iv.field_name FROM invoices AS iv     
WHERE iv.ID=XXXXX

Relative path to absolute path in C#?

Assuming you know the real directory the XML file lives in use Path.Combine, e.g.

var absolute_path = Path.Combine(directoryXmlLivesIn, "..\images\image.jpg");

If you want to get back the full path with any ..'s collapsed then you can use:

Path.GetFullPath((new Uri(absolute_path)).LocalPath);

How to change the height of a <br>?

And remember that (mis)using the <hr> tag as suggested somewhere, will end the <p> tag, so forget about that solution.
If f.ex. something is styled on the surrounding <p>, that style is gone for the rest of the content after the <hr> is inserted.

With CSS, use "..." for overflowed block of multi-lines

The link below provides a pure HTML / CSS solution to this problem.

Browser support - as stated in the article:

So far we have tested on Safari 5.0, IE 9 (must be in standards mode), Opera 12 and Firefox 15.

Older browsers will still work quite well, as the meat of the layout is in normal positioning, margin and padding properties. if your platform is older (e.g. Firefox 3.6, IE 8), you can use the method but redo the gradient as a standalone PNG image or DirectX filter.

http://www.mobify.com/dev/multiline-ellipsis-in-pure-css

the css:

p { margin: 0; padding: 0; font-family: sans-serif;}

.ellipsis {
    overflow: hidden;
    height: 200px;
    line-height: 25px;
    margin: 20px;
    border: 5px solid #AAA; }

.ellipsis:before {
    content:"";
    float: left;
    width: 5px; height: 200px; }

.ellipsis > *:first-child {
    float: right;
    width: 100%;
    margin-left: -5px; }        

.ellipsis:after {
    content: "\02026";  

    box-sizing: content-box;
    -webkit-box-sizing: content-box;
    -moz-box-sizing: content-box;

    float: right; position: relative;
    top: -25px; left: 100%; 
    width: 3em; margin-left: -3em;
    padding-right: 5px;

    text-align: right;

    background: -webkit-gradient(linear, left top, right top,
        from(rgba(255, 255, 255, 0)), to(white), color-stop(50%, white));
    background: -moz-linear-gradient(to right, rgba(255, 255, 255, 0), white 50%, white);           
    background: -o-linear-gradient(to right, rgba(255, 255, 255, 0), white 50%, white);
    background: -ms-linear-gradient(to right, rgba(255, 255, 255, 0), white 50%, white);
    background: linear-gradient(to right, rgba(255, 255, 255, 0), white 50%, white); }

the html:

<div class="ellipsis">
    <div>
        <p>Call me Ishmael.  Some years ago &ndash; never mind how long precisely &ndash; having little or no money in my purse, and nothing particular to interest me on shore, I thought I would sail about a little and see the watery part of the world.  It is a way I have of driving off the spleen, and regulating the circulation.  Whenever I find myself growing grim about the mouth; whenever it is a damp, drizzly November in my soul; whenever I find myself involuntarily pausing before coffin warehouses, and bringing up the rear of every funeral I meet; and especially whenever my hypos get such an upper hand of me, that it requires a strong moral principle to prevent me from deliberately stepping into the street, and methodically knocking people's hats off &ndash; then, I account it high time to get to sea as soon as I can.</p>  
    </div>
</div>

the fiddle

(resize browser's window for testing)

git: fatal unable to auto-detect email address

Had similar problem, I'm fairly new so take this with a grain of salt but I needed to go up a directory first, set the username, then go back down to git repository.

cd ..    
git config --global user.email "[email protected]"
git config --global user.name "your_name"
cd <your repository folder>

Hope this helps anyone else that gets stuck

Why do we use Base64?

Your first mistake is thinking that ASCII encoding and Base64 encoding are interchangeable. They are not. They are used for different purposes.

  • When you encode text in ASCII, you start with a text string and convert it to a sequence of bytes.
  • When you encode data in Base64, you start with a sequence of bytes and convert it to a text string.

To understand why Base64 was necessary in the first place we need a little history of computing.


Computers communicate in binary - 0s and 1s - but people typically want to communicate with more rich forms data such as text or images. In order to transfer this data between computers it first has to be encoded into 0s and 1s, sent, then decoded again. To take text as an example - there are many different ways to perform this encoding. It would be much simpler if we could all agree on a single encoding, but sadly this is not the case.

Originally a lot of different encodings were created (e.g. Baudot code) which used a different number of bits per character until eventually ASCII became a standard with 7 bits per character. However most computers store binary data in bytes consisting of 8 bits each so ASCII is unsuitable for tranferring this type of data. Some systems would even wipe the most significant bit. Furthermore the difference in line ending encodings across systems mean that the ASCII character 10 and 13 were also sometimes modified.

To solve these problems Base64 encoding was introduced. This allows you to encode arbitrary bytes to bytes which are known to be safe to send without getting corrupted (ASCII alphanumeric characters and a couple of symbols). The disadvantage is that encoding the message using Base64 increases its length - every 3 bytes of data is encoded to 4 ASCII characters.

To send text reliably you can first encode to bytes using a text encoding of your choice (for example UTF-8) and then afterwards Base64 encode the resulting binary data into a text string that is safe to send encoded as ASCII. The receiver will have to reverse this process to recover the original message. This of course requires that the receiver knows which encodings were used, and this information often needs to be sent separately.

Historically it has been used to encode binary data in email messages where the email server might modify line-endings. A more modern example is the use of Base64 encoding to embed image data directly in HTML source code. Here it is necessary to encode the data to avoid characters like '<' and '>' being interpreted as tags.


Here is a working example:

I wish to send a text message with two lines:

Hello
world!

If I send it as ASCII (or UTF-8) it will look like this:

72 101 108 108 111 10 119 111 114 108 100 33

The byte 10 is corrupted in some systems so we can base 64 encode these bytes as a Base64 string:

SGVsbG8Kd29ybGQh

Which when encoded using ASCII looks like this:

83 71 86 115 98 71 56 75 100 50 57 121 98 71 81 104

All the bytes here are known safe bytes, so there is very little chance that any system will corrupt this message. I can send this instead of my original message and let the receiver reverse the process to recover the original message.

How can I set the form action through JavaScript?

Change the action URL of a form:

 <form id="myForm" action="">

     <button onclick="changeAction()">Try it</button>

 </form>

 <script>
     function changeAction() {

         document.getElementById("myForm").action = "url/action_page.php";
     }
 </script>

Swift 3: Display Image from URL

let url = ("https://firebasestorage.googleapis.com/v0/b/qualityaudit-678a4.appspot.com/o/profile_images%2FBFA28EDD-9E15-4CC3-9AF8-496B91E74A11.png?alt=media&token=b4518b07-2147-48e5-93fb-3de2b768412d")


self.myactivityindecator.startAnimating()

let urlString = url
    guard let url = URL(string: urlString) else { return }
    URLSession.shared.dataTask(with: url)


{
(data, response, error) in
        if error != nil {
            print("Failed fetching image:", error!)
            return
        }

        guard let response = response as? HTTPURLResponse, response.statusCode == 200 else {
            print("error")
            return
        }

        DispatchQueue.main.async {
            let image = UIImage(data: data!)
        let myimageview = UIImageView(image: image)
            print(myimageview)
            self.imgdata.image = myimageview.image
self.myactivityindecator.stopanimating()

     }
  }.resume()

How to dynamic filter options of <select > with jQuery?

You can use select2 plugin for creating such a filter. With this lot's of coding work can be avoided. You can grab the plugin from https://select2.github.io/

This plugin is much simple to apply and even advanced work can be easily done with it. :)

The specified child already has a parent. You must call removeView() on the child's parent first

if you are adding the same view repeatedly in a for loop .. if this is the case then try creating the View object of the layout inside the for loop . and add the view in side the for loop

To avoid such issues

How to render a DateTime object in a Twig template

You can use date filter:

{{ game.gameDate|date("m/d/Y") }}

What techniques can be used to speed up C++ compilation times?

Use

#pragma once

at the top of header files, so if they're included more than once in a translation unit, the text of the header will only get included and parsed once.

Extract the filename from a path

$file = Get-Item -Path "c:/foo/foobar.txt"
$file.Name

Works with both relative an absolute paths

How to make a button redirect to another page using jQuery or just Javascript

You can use window.location

window.location="/newpage.php";

Or you can just make the form that the search button is in have a action of the page you want.

How to send POST request?

You can't achieve POST requests using urllib (only for GET), instead try using requests module, e.g.:

Example 1.0:

import requests

base_url="www.server.com"
final_url="/{0}/friendly/{1}/url".format(base_url,any_value_here)

payload = {'number': 2, 'value': 1}
response = requests.post(final_url, data=payload)

print(response.text) #TEXT/HTML
print(response.status_code, response.reason) #HTTP

Example 1.2:

>>> import requests

>>> payload = {'key1': 'value1', 'key2': 'value2'}

>>> r = requests.post("http://httpbin.org/post", data=payload)
>>> print(r.text)
{
  ...
  "form": {
    "key2": "value2",
    "key1": "value1"
  },
  ...
}

Example 1.3:

>>> import json

>>> url = 'https://api.github.com/some/endpoint'
>>> payload = {'some': 'data'}

>>> r = requests.post(url, data=json.dumps(payload))

xls to csv converter

I've tested all anwers, but they were all too slow for me. If you have Excel installed you can use the COM.

I thought initially it would be slower since it will load everything for the actual Excel application, but it isn't for huge files. Maybe because the algorithm for opening and saving files runs a heavily optimized compiled code, Microsoft guys make a lot of money for it after all.

import sys
import os
import glob
from win32com.client import Dispatch

def main(path):
    excel = Dispatch("Excel.Application")
    if is_full_path(path):
        process_file(excel, path)
    else:
        files = glob.glob(path)
        for file_path in files:
            process_file(excel, file_path)
    excel.Quit()

def process_file(excel, path):
    fullpath = os.path.abspath(path)
    full_csv_path = os.path.splitext(fullpath)[0] + '.csv'
    workbook = excel.Workbooks.Open(fullpath)
    workbook.Worksheets(1).SaveAs(full_csv_path, 6)
    workbook.Saved = 1
    workbook.Close()


def is_full_path(path):
    return path.find(":") > -1

if __name__ == '__main__':
    main(sys.argv[1])

This is very raw code and won't check for errors, print help or anything, it will just create a csv file for each file that matches the pattern you entered in the function so you can batch process a lot of files only launching excel application once.

How to define optional methods in Swift protocol?

Here's a very simple example for swift Classes ONLY, and not for structures or enumerations. Note that the protocol method being optional, has two levels of optional chaining at play. Also the class adopting the protocol needs the @objc attribute in its declaration.

@objc protocol CollectionOfDataDelegate{
   optional func indexDidChange(index: Int)
}


@objc class RootView: CollectionOfDataDelegate{

    var data = CollectionOfData()

   init(){
      data.delegate = self
      data.indexIsNow()
   }

  func indexDidChange(index: Int) {
      println("The index is currently: \(index)")
  }

}

class CollectionOfData{
    var index : Int?
    weak var delegate : CollectionOfDataDelegate?

   func indexIsNow(){
      index = 23
      delegate?.indexDidChange?(index!)
    }

 }

How to drop all stored procedures at once in SQL Server database?

I think this is the simplest way:

DECLARE @sql VARCHAR(MAX)='';

SELECT @sql=@sql+'drop procedure ['+name +'];' FROM sys.objects 
WHERE type = 'p' AND  is_ms_shipped = 0

exec(@sql);

Is there a NumPy function to return the first index of something in an array?

There are lots of operations in NumPy that could perhaps be put together to accomplish this. This will return indices of elements equal to item:

numpy.nonzero(array - item)

You could then take the first elements of the lists to get a single element.

Convert String To date in PHP

Use the strtotime function:

Example:

 $date = "25 december 2009";
 $my_date = date('m/d/y', strtotime($date));
 echo $my_date;

Regex for string not ending with given suffix

.*[^a]$

the regex above will match strings which is not ending with a.

Can't install Scipy through pip

The easy way to install scipy on Windows 10 100% is this: Just pip this ====> pip install scipy==1.0.0rc2

Thank me later :)

Plot logarithmic axes with matplotlib in python

First of all, it's not very tidy to mix pylab and pyplot code. What's more, pyplot style is preferred over using pylab.

Here is a slightly cleaned up code, using only pyplot functions:

from matplotlib import pyplot

a = [ pow(10,i) for i in range(10) ]

pyplot.subplot(2,1,1)
pyplot.plot(a, color='blue', lw=2)
pyplot.yscale('log')
pyplot.show()

The relevant function is pyplot.yscale(). If you use the object-oriented version, replace it by the method Axes.set_yscale(). Remember that you can also change the scale of X axis, using pyplot.xscale() (or Axes.set_xscale()).

Check my question What is the difference between ‘log’ and ‘symlog’? to see a few examples of the graph scales that matplotlib offers.

Writing file to web server - ASP.NET

protected void TestSubmit_ServerClick(object sender, EventArgs e)
{
  using (StreamWriter _testData = new StreamWriter(Server.MapPath("~/data.txt"), true))
 {
  _testData.WriteLine(TextBox1.Text); // Write the file.
 }         
}

Server.MapPath takes a virtual path and returns an absolute one. "~" is used to resolve to the application root.

How to get the url parameters using AngularJS

If you're using ngRoute, you can inject $routeParams into your controller

http://docs.angularjs.org/api/ngRoute/service/$routeParams

If you're using angular-ui-router, you can inject $stateParams

https://github.com/angular-ui/ui-router/wiki/URL-Routing

jQuery add image inside of div tag

Have you tried the following:

$('#theDiv').prepend('<img id="theImg" src="theImg.png" />')

SQL-Server: The backup set holds a backup of a database other than the existing

I was trying to restore a production database to a staging database on the same server.

The only thing that worked in my case was restore to a new blank database. This worked great, did not try to overwrite production files (which it would if you just restore production backup file to existing staging database). Then delete old database and rename - the files will keep the new temp name but in my case that is fine.

(Or otherwise delete the staging database first and then you can restore to new database with same name as staging database)

Difference between filter and filter_by in SQLAlchemy

filter_by is used for simple queries on the column names using regular kwargs, like

db.users.filter_by(name='Joe')

The same can be accomplished with filter, not using kwargs, but instead using the '==' equality operator, which has been overloaded on the db.users.name object:

db.users.filter(db.users.name=='Joe')

You can also write more powerful queries using filter, such as expressions like:

db.users.filter(or_(db.users.name=='Ryan', db.users.country=='England'))

SVN Repository on Google Drive or DropBox

I made my own subversion repository on my Ubuntu One folder. Then, I imported the files to the repository using svn+ssh and my user account password.

When I want to do a checkout, I just checkout from my Ubuntu One folder. The commit process its analogue.

You must setup Ubutnu One on the devices that you want to grant access, then checkout the project from this folder to a temporary folder to edit it.

In my case, I use a folder in the Ubuntu One file-system, so I have the repository and my develop-folder in Ubuntu One.

How to switch back to 'master' with git?

I'm trying to sort of get my head around what's going on over there. Is there anything IN your "example" folder? Git doesn't track empty folders.

If you branched and switched to your new branch then made a new folder and left it empty, and then did "git commit -a", you wouldn't get that new folder in the commit.

Which means it's untracked, which means checking out a different branch wouldn't remove it.

Is there a way to specify which pytest tests to run from a file?

Method 1: Randomly selected tests. Long and ugly.

python -m pytest test/stress/test_performance.py::TestPerformance::test_continuous_trigger test/integration/test_config.py::TestConfig::test_valid_config

Method 2: Use Keyword Expressions.

Note: I am searching by testcase names. Same is applicable to TestClass names.

Case 1: The below will run whichever is found. Since we have used 'OR' .

python -m pytest -k 'test_password_valid or test_no_configuration'

Lets say the two above are actually correct, 2 tests will be run.

Case 2: Now an incorrect name and another correct name.

python -m pytest -k 'test_password_validzzzzzz or test_no_configuration' 

Only one is found and run.

Case 3: If you want all tests to run or no one, then use AND

python -m pytest -k 'test_password_valid and test_no_configuration'

Both will be run if correct or none.

Case 4: Run test only in one folder:

python -m pytest test/project1/integration -k 'test_password_valid or test_no_configuration'

Case 5: Run test from only one file.

python -m pytest test/integration/test_authentication.py -k 'test_password_expiry or test_incorrect_password'

Case 6: Run all tests except the match.

python -m pytest test/integration/test_authentication.py -k 'not  test_incorrect_password'

How can I capitalize the first letter of each word in a string?

As Mark pointed out, you should use .title():

"MyAwesomeString".title()

However, if would like to make the first letter uppercase inside a Django template, you could use this:

{{ "MyAwesomeString"|title }}

Or using a variable:

{{ myvar|title }}

Data binding for TextBox

You need a bindingsource object to act as an intermediary and assist in the binding. Then instead of updating the user interface, update the underlining model.

var model = (Fruit) bindingSource1.DataSource;

model.FruitType = "oranges";

bindingSource.ResetBindings();

Read up on BindingSource and simple data binding for Windows Forms.

How to add data into ManyToMany field?

In case someone else ends up here struggling to customize admin form Many2Many saving behaviour, you can't call self.instance.my_m2m.add(obj) in your ModelForm.save override, as ModelForm.save later populates your m2m from self.cleaned_data['my_m2m'] which overwrites your changes. Instead call:

my_m2ms = list(self.cleaned_data['my_m2ms'])
my_m2ms.extend(my_custom_new_m2ms)
self.cleaned_data['my_m2ms'] = my_m2ms

(It is fine to convert the incoming QuerySet to a list - the ManyToManyField does that anyway.)

Error "Metadata file '...\Release\project.dll' could not be found in Visual Studio"

I find that this usually occurs to me when i still have a method declaration in an interface, which a class implements, but that i had later removed and had forgotten to remove it from the interface as well. I usually just save the entire solution every 30mins n then just revert back to an earlier version if i cant find the error.

TCPDF ERROR: Some data has already been output, can't send PDF file

I had the same error but finally I solved it by suppressing PHP errors Just put this code error_reporting(0); at the top of your print page

    <?php 
    error_reporting(0); //hide php errors
    if( ! defined('BASEPATH')) exit('No direct script access allowed');
    require_once dirname(__FILE__) . '/tohtml/tcpdf/tcpdf.php';
    .... //continue

Convert an integer to a float number

There is no float type. Looks like you want float64. You could also use float32 if you only need a single-precision floating point value.

package main

import "fmt"

func main() {
    i := 5
    f := float64(i)
    fmt.Printf("f is %f\n", f)
}

Can't fix Unsupported major.minor version 52.0 even after fixing compatibility

Hi I found this link that helped me understand the issue. Hope it is useful. Version released so far are

  • Java SE 8 = 52,
  • Java SE 7 = 51,
  • Java SE 6.0 = 50,
  • Java SE 5.0 = 49,
  • JDK 1.4 = 48,
  • JDK 1.3 = 47,
  • JDK 1.2 = 46,
  • JDK 1.1 = 45

and from thata data it simply means

Many people think why do you get a version mismatch error if Java is backward compatible. Well, its true that Java is backward compatible, which means you can run a Java class file or Java binary (JAR file) compiled in lower version (java 6) into higher version e.g. Java 8, but it doesn't mean that you can run a class compiled using Java 7 into Java 5, Why? because higher version usually have features which are not supported by lower version.

Sometimes you may have more than one version of Java installed in you machine. Make sure the application you are running is pointing to the right or highest version available.

iOS: How to store username/password within an app?

try this one:

 KeychainItemWrapper *keychainItem = [[KeychainItemWrapper alloc] initWithIdentifier:@"YourAppLogin" accessGroup:nil];
[keychainItem setObject:@"password you are saving" forKey:kSecValueData]; 
[keychainItem setObject:@"username you are saving" forKey:kSecAttrAccount];

may it will help.

JavaScript function in href vs. onclick

the best way to do this is with:

<a href="#" onclick="someFunction(e)"></a>

The problem is that this WILL add a hash (#) to the end of the page's URL in the browser, thus requiring the user to click the back button twice to go to the page before yours. Considering this, you need to add some code to stop event propagation. Most javascript toolkits will already have a function for this. For example, the dojo toolkit uses

dojo.stopEvent(event);

to do so.

How to check if a value exists in an object using JavaScript

Try:

_x000D_
_x000D_
var obj = {
   "a": "test1",
   "b": "test2"
};

Object.keys(obj).forEach(function(key) {
  if (obj[key] == 'test1') {
    alert('exists');
  }
});
_x000D_
_x000D_
_x000D_

Or

_x000D_
_x000D_
var obj = {
   "a": "test1",
   "b": "test2"
};

var found = Object.keys(obj).filter(function(key) {
  return obj[key] === 'test1';
});

if (found.length) {
   alert('exists');
}
_x000D_
_x000D_
_x000D_

This will not work for NaN and -0 for those values. You can use (instead of ===) what is new in ECMAScript 6:

 Object.is(obj[key], value);

With modern browsers you can also use:

_x000D_
_x000D_
var obj = {
   "a": "test1",
   "b": "test2"
};

if (Object.values(obj).includes('test1')) {
  alert('exists');
}
_x000D_
_x000D_
_x000D_

Use :hover to modify the css of another class?

There are two approaches you can take, to have a hovered element affect (E) another element (F):

  1. F is a child-element of E, or
  2. F is a later-sibling (or sibling's descendant) element of E (in that E appears in the mark-up/DOM before F):

To illustrate the first of these options (F as a descendant/child of E):

.item:hover .wrapper {
    color: #fff;
    background-color: #000;
}?

To demonstrate the second option, F being a sibling element of E:

.item:hover ~ .wrapper {
    color: #fff;
    background-color: #000;
}?

In this example, if .wrapper was an immediate sibling of .item (with no other elements between the two) you could also use .item:hover + .wrapper.

JS Fiddle demonstration.

References:

How to jump to top of browser page

Pure Javascript solution

theId.onclick = () => window.scrollTo({top: 0})

If you want smooth scrolling

theId.onclick = () => window.scrollTo({ top: 0, behavior: `smooth` })

How do I use SELECT GROUP BY in DataTable.Select(Expression)?

dt = dt.AsEnumerable().GroupBy(r => r.Field<int>("ID")).Select(g => g.First()).CopyToDataTable();

Strange PostgreSQL "value too long for type character varying(500)"

By specifying the column as VARCHAR(500) you've set an explicit 500 character limit. You might not have done this yourself explicitly, but Django has done it for you somewhere. Telling you where is hard when you haven't shown your model, the full error text, or the query that produced the error.

If you don't want one, use an unqualified VARCHAR, or use the TEXT type.

varchar and text are limited in length only by the system limits on column size - about 1GB - and by your memory. However, adding a length-qualifier to varchar sets a smaller limit manually. All of the following are largely equivalent:

column_name VARCHAR(500)

column_name VARCHAR CHECK (length(column_name) <= 500) 

column_name TEXT CHECK (length(column_name) <= 500) 

The only differences are in how database metadata is reported and which SQLSTATE is raised when the constraint is violated.

The length constraint is not generally obeyed in prepared statement parameters, function calls, etc, as shown:

regress=> \x
Expanded display is on.
regress=> PREPARE t2(varchar(500)) AS SELECT $1;
PREPARE
regress=> EXECUTE t2( repeat('x',601) );
-[ RECORD 1 ]-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
?column? | xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

and in explicit casts it result in truncation:

regress=> SELECT repeat('x',501)::varchar(1);
-[ RECORD 1 ]
repeat | x

so I think you are using a VARCHAR(500) column, and you're looking at the wrong table or wrong instance of the database.

How to trigger jQuery change event in code

Use That :

$(selector).trigger("change");

OR

$('#id').trigger("click");

OR

$('.class').trigger(event);

Trigger can be any event that javascript support.. Hope it's easy to understandable to all of You.

How do I vertically center an H1 in a div?

This is the jQuery method. Looks like overkill but it calculates the offset.

<html>
<head>
<title></title>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
    <script type="text/javascript" src="https://raw.github.com/dreamerslab/jquery.center/master/jquery.center.js"></script>
    <script type="text/javascript">
        $(function(){

            $('#jquery-center').center();

        });
    </script>

</head>
<body>
    <div id="jquery-center" style="position:absolute;">
       <h1>foo</h1>
    </div>
</body>
</html>

Twitter bootstrap remote modal shows same content every time

This one works for me:

modal

<div class="modal fade" id="searchKaryawan" tabindex="-1" role="dialog" aria-labelledby="SearchKaryawanLabel" aria-hidden="true"> <div class="modal-dialog">
<div class="modal-content">
  <div class="modal-header">
    <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
    <h4 class="modal-title" id="SearchKaryawanLabel">Cari Karyawan</h4>
  </div>
  <div class="modal-body">
    <input type="hidden" name="location">
    <input name="cariNama" type="text" class="form-control" onkeyup="if (this.value.length > 3) cariNikNama();" />
    <div class="links-area" id="links-area"></div>
  </div>
  <div class="modal-footer">
  </div>
</div> </div></div>

script

<script type="text/javascript">$('body').on('hidden.bs.modal', '.modal', function () {  $(".links-area").empty() }); </script>

links-area is area where i put the data and need to clear

How to stop a JavaScript for loop?

To stop a for loop early in JavaScript, you use break:

var remSize = [], 
    szString,
    remData,
    remIndex,
    i;

/* ...I assume there's code here putting entries in `remSize` and assigning something to `remData`... */

remIndex = -1; // Set a default if we don't find it
for (i = 0; i < remSize.length; i++) {      
     // I'm looking for the index i, when the condition is true
     if (remSize[i].size === remData.size) {
          remIndex = i;
          break;       // <=== breaks out of the loop early
     }
}

If you're in an ES2015 (aka ES6) environment, for this specific use case, you can use Array#findIndex (to find the entry's index) or Array#find (to find the entry itself), both of which can be shimmed/polyfilled:

var remSize = [], 
    szString,
    remData,
    remIndex;

/* ...I assume there's code here putting entries in `remSize` and assigning something to `remData`... */

remIndex = remSize.findIndex(function(entry) {
     return entry.size === remData.size;
});

Array#find:

var remSize = [], 
    szString,
    remData,
    remEntry;

/* ...I assume there's code here putting entries in `remSize` and assigning something to `remData`... */

remEntry = remSize.find(function(entry) {
     return entry.size === remData.size;
});

Array#findIndex stops the first time the callback returns a truthy value, returning the index for that call to the callback; it returns -1 if the callback never returns a truthy value. Array#find also stops when it finds what you're looking for, but it returns the entry, not its index (or undefined if the callback never returns a truthy value).

If you're using an ES5-compatible environment (or an ES5 shim), you can use the new some function on arrays, which calls a callback until the callback returns a truthy value:

var remSize = [], 
    szString,
    remData,
    remIndex;

/* ...I assume there's code here putting entries in `remSize` and assigning something to `remData`... */

remIndex = -1; // <== Set a default if we don't find it
remSize.some(function(entry, index) {
    if (entry.size === remData.size) {
        remIndex = index;
        return true; // <== Equivalent of break for `Array#some`
    }
});

If you're using jQuery, you can use jQuery.each to loop through an array; that would look like this:

var remSize = [], 
    szString,
    remData,
    remIndex;

/* ...I assume there's code here putting entries in `remSize` and assigning something to `remData`... */

remIndex = -1; // <== Set a default if we don't find it
jQuery.each(remSize, function(index, entry) {
    if (entry.size === remData.size) {
        remIndex = index;
        return false; // <== Equivalent of break for jQuery.each
    }
});

Non-Static method cannot be referenced from a static context with methods and variables

You need to make both your method - printMenu() and getUserChoice() static, as you are directly invoking them from your static main method, without creating an instance of the class, those methods are defined in. And you cannot invoke a non-static method without any reference to an instance of the class they are defined in.

Alternatively you can change the method invocation part to:

BookStoreApp2 bookStoreApp = new BookStoreApp2();
bookStoreApp.printMenu();
bookStoreApp.getUserChoice();

Docker: How to delete all local Docker images

To delete all images:

docker rmi -f $(docker images -a | awk {'print $3'})

Explanation:

docker images -a | awk {'print $3'}

This command will return all image id's and then used to delete image using its id.

How can I make an svg scale with its parent container?

Messing around & found this CSS seems to contain the SVG in Chrome browser up to the point where the container is larger than the image:

div.inserted-svg-logo svg { max-width:100%; }

Also seems to be working in FF + IE 11.

How to redirect to another page using AngularJS?

I faced issues in redirecting to a different page in an angular app as well

You can add the $window as Ewald has suggested in his answer, or if you don't want to add the $window, just add an timeout and it will work!

setTimeout(function () {
        window.location.href = "http://whereeveryouwant.com";
    }, 500);

How do I define and use an ENUM in Objective-C?

In the .h:

typedef enum {
    PlayerStateOff,
    PlayerStatePlaying,
    PlayerStatePaused
} PlayerState;

MySQL error - #1062 - Duplicate entry ' ' for key 2

As it was said you have a unique index.

However, when I added most of the list yesterday I didn't get this error once even though a lot of the entries I added yesterday have a blank cell in column 2 as well. Whats going on?

That means that all these entries contain value NULL, not empty string ''. Mysql lets you have multiple NULL values in unique fields.