Programs & Examples On #Unit of work

One of the common design patterns in enterprise software development which allows one to maintain a list of objects affected by a business transaction and coordinates the writing out of changes and the resolution of concurrency problems.

CSS /JS to prevent dragging of ghost image?

This work for me, i use some lightbox scripts

_x000D_
_x000D_
.nodragglement {_x000D_
    transform: translate(0px, 0px)!important;_x000D_
}
_x000D_
_x000D_
_x000D_

Google Maps API v3: Can I setZoom after fitBounds?

I don't like to suggest it, but if you must try - first call

gmap.fitBounds(bounds);

Then create a new Thread/AsyncTask, have it sleep for 20-50ms or so and then call

gmap.setZoom( Math.max(6, gmap.getZoom()) );

from the UI thread (use a handler or the onPostExecute method for AsyncTask).

I don't know if it works, just a suggestion. Other than that you'd have to somehow calculate the zoom level from your points yourself, check if it's too low, correct it and then just call gmap.setZoom(correctedZoom)

jQuery Validation plugin: disable validation for specified submit buttons

This question is old, but I found another way around it is to use $('#formId')[0].submit(), which gets the dom element instead of the jQuery object, thus bypassing any validation hooks. This button submits the parent form that contains the input.

<input type='button' value='SubmitWithoutValidation' onclick='$(this).closest('form')[0].submit()'/>

Also, make sure you don't have any input's named "submit", or it overrides the function named submit.

move_uploaded_file gives "failed to open stream: Permission denied" error

I wanted to add this to the previous suggestions. If you are using a version of Linux that has SELinux enabled then you should also execute this in a shell:

chcon -R --type httpd_sys_rw_content_t /path/to/your/directory

Along with giving your web server user permissions either through group or changing of the owner of the directory.

Which is the correct C# infinite loop, for (;;) or while (true)?

The C# compiler will transform both

for(;;)
{
    // ...
}

and

while (true)
{
    // ...
}

into

{
    :label
    // ...
    goto label;
}

The CIL for both is the same. Most people find while(true) to be easier to read and understand. for(;;) is rather cryptic.

Source:

I messed a little more with .NET Reflector, and I compiled both loops with the "Optimize Code" on in Visual Studio.

Both loops compile into (with .NET Reflector):

Label_0000:
    goto Label_0000;

Raptors should attack soon.

Can I invoke an instance method on a Ruby module without including it?

Another way to do it if you "own" the module is to use module_function.

module UsefulThings
  def a
    puts "aaay"
  end
  module_function :a

  def b
    puts "beee"
  end
end

def test
  UsefulThings.a
  UsefulThings.b # Fails!  Not a module method
end

test

UILabel with text of two different colors

In my case I'm using Xcode 10.1. There is a option of switching between plain text and Attributed text in Label text in Interface Builder

enter image description here

Hope this may help someone else..!

gdb fails with "Unable to find Mach task port for process-id" error

In Snow Leopard and later Mac OS versions, it isn't enough to codesign the gdb executable.

You have to follow this guide to make it work: http://www.opensource.apple.com/source/lldb/lldb-69/docs/code-signing.txt

The guide explains how to do it for lldb, but the process is exactly the same for gdb.

Loading cross-domain endpoint with AJAX

Figured it out. Used this instead.

$('.div_class').load('http://en.wikipedia.org/wiki/Cross-origin_resource_sharing #toctitle');

Recursive Fibonacci

By definition, the first two numbers in the Fibonacci sequence are 1 and 1, or 0 and 1. Therefore, you should handle it.

#include <iostream>
using namespace std;

int Fibonacci(int);

int main(void) {
    int number;

    cout << "Please enter a positive integer: ";
    cin >> number;
    if (number < 0)
        cout << "That is not a positive integer.\n";
    else
        cout << number << " Fibonacci is: " << Fibonacci(number) << endl;
}

int Fibonacci(int x) 
{
    if (x < 2){
     return x;
    }     
    return (Fibonacci (x - 1) + Fibonacci (x - 2));
}

Pure CSS checkbox image replacement

If you are still looking for further more customization,

Check out the following library: https://lokesh-coder.github.io/pretty-checkbox/

Thanks

To show error message without alert box in Java Script

Try like this:

function validate(el, status){
     var targetVal = document.getElementById(el).value;
     var statusEl = document.getElementById(status);
     if(targetVal.length > 0){
        statusEl.innerHTML = '';
  }
     else{
        statusEL.innerHTML = "Invalid Name";
   }
}

Now HTML:

<!doctype html>
<html lang='en'>
<head>
<title>Derp...</title>
</head>
<body>
<form name="myform">
  First_Name
  <input type="text" id="fname" name="fname" onblur="validate('fname','fnameStatus')">
  <br />
  <span id="fnameStatus"></span>
  <br />
  Last_Name
  <input type="text" id="lname" name="lname" onblur="validate('lname','lnameStatus')"> 
  <br />
  <span id="lnameStatus"></span>
  <br />
  <input type=button value=check> 
</form>
</body>
</html>

How to make clang compile to llvm IR

If you have multiple source files, you probably actually want to use link-time-optimization to output one bitcode file for the entire program. The other answers given will cause you to end up with a bitcode file for every source file.

Instead, you want to compile with link-time-optimization

clang -flto -c program1.c -o program1.o
clang -flto -c program2.c -o program2.o

and for the final linking step, add the argument -Wl,-plugin-opt=also-emit-llvm

clang -flto -Wl,-plugin-opt=also-emit-llvm program1.o program2.o -o program

This gives you both a compiled program and the bitcode corresponding to it (program.bc). You can then modify program.bc in any way you like, and recompile the modified program at any time by doing

clang program.bc -o program

although be aware that you need to include any necessary linker flags (for external libraries, etc) at this step again.

Note that you need to be using the gold linker for this to work. If you want to force clang to use a specific linker, create a symlink to that linker named "ld" in a special directory called "fakebin" somewhere on your computer, and add the option

-B/home/jeremy/fakebin

to any linking steps above.

What is the advantage of using heredoc in PHP?

Heredoc's are a great alternative to quoted strings because of increased readability and maintainability. You don't have to escape quotes and (good) IDEs or text editors will use the proper syntax highlighting.

A very common example: echoing out HTML from within PHP:

$html = <<<HTML
  <div class='something'>
    <ul class='mylist'>
      <li>$something</li>
      <li>$whatever</li>
      <li>$testing123</li>
    </ul>
  </div>
HTML;

// Sometime later
echo $html;

It is easy to read and easy to maintain.

The alternative is echoing quoted strings, which end up containing escaped quotes and IDEs aren't going to highlight the syntax for that language, which leads to poor readability and more difficulty in maintenance.

Updated answer for Your Common Sense

Of course you wouldn't want to see an SQL query highlighted as HTML. To use other languages, simply change the language in the syntax:

$sql = <<<SQL
       SELECT * FROM table
SQL;

Convert date field into text in Excel

You don't need to convert the original entry - you can use TEXT function in the concatenation formula, e.g. with date in A1 use a formula like this

="Today is "&TEXT(A1,"dd-mm-yyyy")

You can change the "dd-mm-yyyy" part as required

How do I get the file extension of a file in Java?

String extension = com.google.common.io.Files.getFileExtension("fileName.jpg");

Full Screen DialogFragment in Android

This below answer works for me in fragment dialog.  


  Dialog dialog = getDialog();
        if (dialog != null)
        {
            int width = ViewGroup.LayoutParams.MATCH_PARENT;
            int height = ViewGroup.LayoutParams.MATCH_PARENT;
            dialog.getWindow().setLayout(width, height);
        }

Resolving LNK4098: defaultlib 'MSVCRT' conflicts with

I get this every time I want to create an application in VC++.

Right-click the project, select Properties then under 'Configuration properties | C/C++ | Code Generation', select "Multi-threaded Debug (/MTd)" for Debug configuration.

Note that this does not change the setting for your Release configuration - you'll need to go to the same location and select "Multi-threaded (/MT)" for Release.

How to calculate the number of occurrence of a given character in each row of a column of strings?

s <- "aababacababaaathhhhhslsls jsjsjjsaa ghhaalll"
p <- "a"
s2 <- gsub(p,"",s)
numOcc <- nchar(s) - nchar(s2)

May not be the efficient one but solve my purpose.

Creating a chart in Excel that ignores #N/A or blank cells

One solution is that the chart/graph doesn't show the hidden rows.

You can test this features doing: 1)right click on row number 2)click on hide.

For doing it automatically, this is the simple code:

For Each r In worksheet.Range("A1:A200")
   If r.Value = "" Then 
      r.EntireRow.Hidden = True 
   Else: 
      r.EntireRow.Hidden = False
Next

Call Javascript onchange event by programmatically changing textbox value

You can fire the event simply with

document.getElementById("elementID").onchange();

I dont know if this doesnt work on some browsers, but it should work on FF 3 and IE 7+

make arrayList.toArray() return more specific types

It doesn't really need to return Object[], for example:-

    List<Custom> list = new ArrayList<Custom>();
    list.add(new Custom(1));
    list.add(new Custom(2));

    Custom[] customs = new Custom[list.size()];
    list.toArray(customs);

    for (Custom custom : customs) {
        System.out.println(custom);
    }

Here's my Custom class:-

public class Custom {
    private int i;

    public Custom(int i) {
        this.i = i;
    }

    @Override
    public String toString() {
        return String.valueOf(i);
    }
}

What's a .sh file?

I know this is an old question and I probably won't help, but many Linux distributions(e.g., ubuntu) have a "Live cd/usb" function, so if you really need to run this script, you could try booting your computer into Linux. Just burn a .iso to a flash drive (here's how http://goo.gl/U1wLYA), start your computer with the drive plugged in, and press the F key for boot menu. If you choose "...USB...", you will boot into the OS you just put on the drive.

How to fix div on scroll

On jQuery for designers there's a well written post about this, this is the jQuery snippet that does the magic. just replace #comment with the selector of the div that you want to float.

Note: To see the whole article go here: http://jqueryfordesigners.com/fixed-floating-elements/

$(document).ready(function () {
  var $obj = $('#comment');
  var top = $obj.offset().top - parseFloat($obj.css('marginTop').replace(/auto/, 0));

  $(window).scroll(function (event) {
    // what the y position of the scroll is
    var y = $(this).scrollTop();

    // whether that's below the form
    if (y >= top) {
      // if so, ad the fixed class
      $obj.addClass('fixed');
    } else {
      // otherwise remove it
      $obj.removeClass('fixed');
    }
  });
});

ImageView in android XML layout with layout_height="wrap_content" has padding top & bottom

I had a simular issue and resolved it using android:adjustViewBounds="true" on the ImageView.

<ImageView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:adjustViewBounds="true"
    android:contentDescription="@string/banner_alt"
    android:src="@drawable/banner_portrait" />

How to pass a datetime parameter?

It used to be a painful task, but now we can use toUTCString():

Example:

[HttpPost]
public ActionResult Query(DateTime Start, DateTime End)

Put the below into Ajax post request

data: {
    Start: new Date().toUTCString(),
    End: new Date().toUTCString()
},

how to remove untracked files in Git?

User interactive approach:

git clean -i -fd

Remove .classpath [y/N]? N
Remove .gitignore [y/N]? N
Remove .project [y/N]? N
Remove .settings/ [y/N]? N
Remove src/com/amazon/arsdumpgenerator/inspector/ [y/N]? y
Remove src/com/amazon/arsdumpgenerator/manifest/ [y/N]? y
Remove src/com/amazon/arsdumpgenerator/s3/ [y/N]? y
Remove tst/com/amazon/arsdumpgenerator/manifest/ [y/N]? y
Remove tst/com/amazon/arsdumpgenerator/s3/ [y/N]? y

-i for interactive
-f for force
-d for directory
-x for ignored files(add if required)

Note: Add -n or --dry-run to just check what it will do.

JPA or JDBC, how are they different?

Main difference between JPA and JDBC is level of abstraction.

JDBC is a low level standard for interaction with databases. JPA is higher level standard for the same purpose. JPA allows you to use an object model in your application which can make your life much easier. JDBC allows you to do more things with the Database directly, but it requires more attention. Some tasks can not be solved efficiently using JPA, but may be solved more efficiently with JDBC.

How to concatenate strings in windows batch file for loop?

A very simple example:

SET a=Hello
SET b=World
SET c=%a% %b%!
echo %c%

The result should be:

Hello World!

MVC ajax json post to controller action method

Below is how I got this working.

The Key point was: I needed to use the ViewModel associated with the view in order for the runtime to be able to resolve the object in the request.

[I know that that there is a way to bind an object other than the default ViewModel object but ended up simply populating the necessary properties for my needs as I could not get it to work]

[HttpPost]  
  public ActionResult GetDataForInvoiceNumber(MyViewModel myViewModel)  
  {            
     var invoiceNumberQueryResult = _viewModelBuilder.HydrateMyViewModelGivenInvoiceDetail(myViewModel.InvoiceNumber, myViewModel.SelectedCompanyCode);
     return Json(invoiceNumberQueryResult, JsonRequestBehavior.DenyGet);
  }

The JQuery script used to call this action method:

var requestData = {
         InvoiceNumber: $.trim(this.value),
         SelectedCompanyCode: $.trim($('#SelectedCompanyCode').val())
      };


      $.ajax({
         url: '/en/myController/GetDataForInvoiceNumber',
         type: 'POST',
         data: JSON.stringify(requestData),
         dataType: 'json',
         contentType: 'application/json; charset=utf-8',
         error: function (xhr) {
            alert('Error: ' + xhr.statusText);
         },
         success: function (result) {
            CheckIfInvoiceFound(result);
         },
         async: true,
         processData: false
      });

Builder Pattern in Effective Java

I personally prefer to use the other approach, when you have 2 different classes. So you don't need any static class. This is basically to avoid write Class.Builder when you has to create a new instance.

public class Person {
    private String attr1;
    private String attr2;
    private String attr3;

    // package access
    Person(PersonBuilder builder) {
        this.attr1 = builder.getAttr1();
        // ...
    }

    // ...
    // getters and setters 
}

public class PersonBuilder (
    private String attr1;
    private String attr2;
    private String attr3;

    // constructor with required attribute
    public PersonBuilder(String attr1) {
        this.attr1 = attr1;
    }

    public PersonBuilder setAttr2(String attr2) {
        this.attr2 = attr2;
        return this;
    }

    public PersonBuilder setAttr3(String attr3) {
        this.attr3 = attr3;
        return this;
    }

    public Person build() {
        return new Person(this);
    }
    // ....
}

So, you can use your builder like this:

Person person = new PersonBuilder("attr1")
                            .setAttr2("attr2")
                            .build();

Remove old Fragment from fragment manager

Probably you instance old fragment it is keeping a reference. See this interesting article Memory leaks in Android — identify, treat and avoid

If you use addToBackStack, this keeps a reference to instance fragment avoiding to Garbage Collector erase the instance. The instance remains in fragments list in fragment manager. You can see the list by

ArrayList<Fragment> fragmentList = fragmentManager.getFragments();

The next code is not the best solution (because don´t remove the old fragment instance in order to avoid memory leaks) but removes the old fragment from fragmentManger fragment list

int index = fragmentManager.getFragments().indexOf(oldFragment);
fragmentManager.getFragments().set(index, null);

You cannot remove the entry in the arrayList because apparenly FragmentManager works with index ArrayList to get fragment.

I usually use this code for working with fragmentManager

public void replaceFragment(Fragment fragment, Bundle bundle) {

    if (bundle != null)
        fragment.setArguments(bundle);

    FragmentManager fragmentManager = getSupportFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
    Fragment oldFragment = fragmentManager.findFragmentByTag(fragment.getClass().getName());

    //if oldFragment already exits in fragmentManager use it
    if (oldFragment != null) {
        fragment = oldFragment;
    }

    fragmentTransaction.replace(R.id.frame_content_main, fragment, fragment.getClass().getName());

    fragmentTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);

    fragmentTransaction.commit();
}

What is private bytes, virtual bytes, working set?

You should not try to use perfmon, task manager or any tool like that to determine memory leaks. They are good for identifying trends, but not much else. The numbers they report in absolute terms are too vague and aggregated to be useful for a specific task such as memory leak detection.

A previous reply to this question has given a great explanation of what the various types are.

You ask about a tool recommendation: I recommend Memory Validator. Capable of monitoring applications that make billions of memory allocations.

http://www.softwareverify.com/cpp/memory/index.html

Disclaimer: I designed Memory Validator.

Time complexity of accessing a Python dict

It would be easier to make suggestions if you provided example code and data.

Accessing the dictionary is unlikely to be a problem as that operation is O(1) on average, and O(N) amortized worst case. It's possible that the built-in hashing functions are experiencing collisions for your data. If you're having problems with has the built-in hashing function, you can provide your own.

Python's dictionary implementation reduces the average complexity of dictionary lookups to O(1) by requiring that key objects provide a "hash" function. Such a hash function takes the information in a key object and uses it to produce an integer, called a hash value. This hash value is then used to determine which "bucket" this (key, value) pair should be placed into.

You can overwrite the __hash__ method in your class to implement a custom hash function like this:

def __hash__(self):    
    return hash(str(self))

Depending on what your data actually looks like, you might be able to come up with a faster hash function that has fewer collisions than the standard function. However, this is unlikely. See the Python Wiki page on Dictionary Keys for more information.

How can I render inline JavaScript with Jade / Pug?

No use script tag only.

Solution with |:

script
  | if (10 == 10) {
  |   alert("working")
  | }

Or with a .:

script.
  if (10 == 10) {
    alert("working")
  }

How to parse XML and count instances of a particular node attribute?

Python has an interface to the expat XML parser.

xml.parsers.expat

It's a non-validating parser, so bad XML will not be caught. But if you know your file is correct, then this is pretty good, and you'll probably get the exact info you want and you can discard the rest on the fly.

stringofxml = """<foo>
    <bar>
        <type arg="value" />
        <type arg="value" />
        <type arg="value" />
    </bar>
    <bar>
        <type arg="value" />
    </bar>
</foo>"""
count = 0
def start(name, attr):
    global count
    if name == 'type':
        count += 1

p = expat.ParserCreate()
p.StartElementHandler = start
p.Parse(stringofxml)

print count # prints 4

Is there a way to programmatically scroll a scroll view to a specific edit text?

I think I have found more elegant and less error prone solution using

ScrollView.requestChildRectangleOnScreen

There is no math involved, and contrary to other proposed solutions, it will handle correctly scrolling both up and down.

/**
 * Will scroll the {@code scrollView} to make {@code viewToScroll} visible
 * 
 * @param scrollView parent of {@code scrollableContent}
 * @param scrollableContent a child of {@code scrollView} whitch holds the scrollable content (fills the viewport).
 * @param viewToScroll a child of {@code scrollableContent} to whitch will scroll the the {@code scrollView}
 */
void scrollToView(ScrollView scrollView, ViewGroup scrollableContent, View viewToScroll) {
    Rect viewToScrollRect = new Rect(); //coordinates to scroll to
    viewToScroll.getHitRect(viewToScrollRect); //fills viewToScrollRect with coordinates of viewToScroll relative to its parent (LinearLayout) 
    scrollView.requestChildRectangleOnScreen(scrollableContent, viewToScrollRect, false); //ScrollView will make sure, the given viewToScrollRect is visible
}

It is a good idea to wrap it into postDelayed to make it more reliable, in case the ScrollView is being changed at the moment

/**
 * Will scroll the {@code scrollView} to make {@code viewToScroll} visible
 * 
 * @param scrollView parent of {@code scrollableContent}
 * @param scrollableContent a child of {@code scrollView} whitch holds the scrollable content (fills the viewport).
 * @param viewToScroll a child of {@code scrollableContent} to whitch will scroll the the {@code scrollView}
 */
private void scrollToView(final ScrollView scrollView, final ViewGroup scrollableContent, final View viewToScroll) {
    long delay = 100; //delay to let finish with possible modifications to ScrollView
    scrollView.postDelayed(new Runnable() {
        public void run() {
            Rect viewToScrollRect = new Rect(); //coordinates to scroll to
            viewToScroll.getHitRect(viewToScrollRect); //fills viewToScrollRect with coordinates of viewToScroll relative to its parent (LinearLayout) 
            scrollView.requestChildRectangleOnScreen(scrollableContent, viewToScrollRect, false); //ScrollView will make sure, the given viewToScrollRect is visible
        }
    }, delay);
}

Understanding Spring @Autowired usage

Nothing in the example says that the "classes implementing the same interface". MovieCatalog is a type and CustomerPreferenceDao is another type. Spring can easily tell them apart.

In Spring 2.x, wiring of beans mostly happened via bean IDs or names. This is still supported by Spring 3.x but often, you will have one instance of a bean with a certain type - most services are singletons. Creating names for those is tedious. So Spring started to support "autowire by type".

What the examples show is various ways that you can use to inject beans into fields, methods and constructors.

The XML already contains all the information that Spring needs since you have to specify the fully qualified class name in each bean. You need to be a bit careful with interfaces, though:

This autowiring will fail:

 @Autowired
 public void prepare( Interface1 bean1, Interface1 bean2 ) { ... }

Since Java doesn't keep the parameter names in the byte code, Spring can't distinguish between the two beans anymore. The fix is to use @Qualifier:

 @Autowired
 public void prepare( @Qualifier("bean1") Interface1 bean1,
     @Qualifier("bean2")  Interface1 bean2 ) { ... }

What are Transient and Volatile Modifiers?

Transient :

First need to know where it needed how it bridge the gap.

1) An Access modifier transient is only applicable to variable component only. It will not used with method or class.

2) Transient keyword cannot be used along with static keyword.

3) What is serialization and where it is used? Serialization is the process of making the object's state persistent. That means the state of the object is converted into a stream of bytes to be used for persisting (e.g. storing bytes in a file) or transferring (e.g. sending bytes across a network). In the same way, we can use the deserialization to bring back the object's state from bytes. This is one of the important concepts in Java programming because serialization is mostly used in networking programming. The objects that need to be transmitted through the network have to be converted into bytes. Before understanding the transient keyword, one has to understand the concept of serialization. If the reader knows about serialization, please skip the first point.

Note 1) Transient is mainly use for serialzation process. For that the class must implement the java.io.Serializable interface. All of the fields in the class must be serializable. If a field is not serializable, it must be marked transient.

Note 2) When deserialized process taken place they get set to the default value - zero, false, or null as per type constraint.

Note 3) Transient keyword and its purpose? A field which is declare with transient modifier it will not take part in serialized process. When an object is serialized(saved in any state), the values of its transient fields are ignored in the serial representation, while the field other than transient fields will take part in serialization process. That is the main purpose of the transient keyword.

How can I get client information such as OS and browser

You cannot reliably get this information. The basis of several answers provided here is to examine the User-Agent header of the HTTP request. However, there is no way to know if the information in the User-Agent header is truthful. The client sending the request can write anything in that header. So its content can be spoofed, or not sent at all.

PHP convert string to hex and hex to string

PHP :

string to hex:

implode(unpack("H*", $string));

hex to string:

pack("H*", $hex);

Why maven settings.xml file is not there?

By Installing Maven you can not expect the settings.xml in your .m2 folder(If may be hidden folder, to unhide just press Ctrl+h). You need to place the file explicitly at that location. After placing the file maven plugin for eclipse will start using that file too.

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

I had the same problem. When I tried the accepted answer (rockyb), I got the message that the package was already installed and assigned to my project. When I checked the references list, it was NOT referenced, however.

The Microsoft.Web.Infrastructure was installed in my solution's packages folder. Instead of using NuGet to add the package, I just used the Add Reference option. On the left side of the pop-up window, I chose Browse, and then pressed the Browse button on the bottom of the window. I navigated to the packages folder under the folder that my solution was in, then drilled down to the ...\mysolution\packages\Microsoft.Web.Infrastructure.1.0.0.0\lib\net40 and clicked on the Microsoft.Web.Infrastructure.dll. After clicking OK, the package showed up in my References list. I used the Web Deploy Package option to deploy my website and everything worked.

window.onload vs <body onload=""/>

It is a accepted standard to have content, layout and behavior separate. So window.onload() will be more suitable to use than <body onload=""> though both do the same work.

Unable to load DLL (Module could not be found HRESULT: 0x8007007E)

I have come across the same problem, In my case I had two 32 bit pcs. One with .NET4.5 installed and other one was fresh PC.

my 32-bit cpp dll(Release mode build) was working fine with .NET installed PC but Not with fresh PC where I got the below error

Unable to load DLL 'PrinterSettings.dll': The specified module could not be found. (Exception from HRESULT: 0x8007007E)

finally,

I just built my project in Debug mode configuration and this time my cpp dll was working fine.

How to connect a Windows Mobile PDA to Windows 10

Had the same problem. Came across an article from Zebra with the fix that worked for me:

  1. Open services.msc
  2. Go to Windows Mobile-2003-based device connectivity
  3. Right click Windows Mobile-2003-based device connectivity and click Properties
  4. Go to Log On Tab
  5. Choose Local System Account

image description

  1. Click Apply
  2. Go to General Tab
  3. Press Stop and wait
  4. Once stopped, press Start
  5. Press OK
  6. Restart your PC
  7. Retry the Windows Mobile Device Center

Original article can be found here

Update values from one column in same table to another in SQL Server

This works for me

select * from stuff

update stuff
set TYPE1 = TYPE2
where TYPE1 is null;

update stuff
set TYPE1 = TYPE2
where TYPE1 ='Blank';

select * from stuff

iPhone system font

Swift

Specific font

Setting a specific font in Swift is done like this:

let myFont = UIFont(name: "Helvetica", size: 17)

If you don't know the name, you can get a list of the available font names like this:

print(UIFont.familyNames())

Or an even more detailed list like this:

for familyName in UIFont.familyNames() {
    print(UIFont.fontNamesForFamilyName(familyName))
}

But the system font changes from version to version of iOS. So it would be better to get the system font dynamically.

System font

let myFont = UIFont.systemFontOfSize(17)

But we have the size hard-coded in. What if the user's eyes are bad and they want to make the font larger? Of course, you could make a setting in your app for the user to change the font size, but this would be annoying if the user had to do this separately for every single app on their phone. It would be easier to just make one change in the general settings...

Dynamic font

let myFont = UIFont.preferredFont(forTextStyle: .body)

Ah, now we have the system font at the user's chosen size for the Text Style we are working with. This is the recommended way of setting the font. See Supporting Dynamic Type for more info on this.

Related

How to retrieve Request Payload

If I understand the situation correctly, you are just passing json data through the http body, instead of application/x-www-form-urlencoded data.

You can fetch this data with this snippet:

$request_body = file_get_contents('php://input');

If you are passing json, then you can do:

$data = json_decode($request_body);

$data then contains the json data is php array.

php://input is a so called wrapper.

php://input is a read-only stream that allows you to read raw data from the request body. In the case of POST requests, it is preferable to use php://input instead of $HTTP_RAW_POST_DATA as it does not depend on special php.ini directives. Moreover, for those cases where $HTTP_RAW_POST_DATA is not populated by default, it is a potentially less memory intensive alternative to activating always_populate_raw_post_data. php://input is not available with enctype="multipart/form-data".

Getting the closest string match

I contest that choice B is closer to the test string, as it's only 4 characters(and 2 deletes) from being the original string. Whereas you see C as closer because it includes both brown and red. It would, however, have a greater edit distance.

There is an algorithm called Levenshtein Distance which measures the edit distance between two inputs.

Here is a tool for that algorithm.

  1. Rates choice A as a distance of 15.
  2. Rates choice B as a distance of 6.
  3. Rates choice C as a distance of 9.

EDIT: Sorry, I keep mixing strings in the levenshtein tool. Updated to correct answers.

Uncaught TypeError: Cannot read property 'appendChild' of null

Use querySelector insted of getElementById();

var c = document.querySelector('#mainContent');
    c.appendChild(document.createElement('div'));

Generate Controller and Model

Use:

make:model {{SingularName}}

e.g

make:model Video

Java stack overflow error - how to increase the stack size in Eclipse?

It may be curable by increasing the stack size - but a better solution would be to work out how to avoid recursing so much. A recursive solution can always be converted to an iterative solution - which will make your code scale to larger inputs much more cleanly. Otherwise you'll really be guessing at how much stack to provide, which may not even be obvious from the input.

Are you absolutely sure it's failing due to the size of the input rather than a bug in the code, by the way? Just how deep is this recursion?

EDIT: Okay, having seen the update, I would personally try to rewrite it to avoid using recursion. Generally having a Stack<T> of "things still do to" is a good starting point to remove recursion.

SimpleDateFormat parse loses timezone

tl;dr

what is the way to retrieve a Date object so that its always in GMT?

Instant.now() 

Details

You are using troublesome confusing old date-time classes that are now supplanted by the java.time classes.

Instant = UTC

The Instant class represents a moment on the timeline in UTC with a resolution of nanoseconds (up to nine (9) digits of a decimal fraction).

Instant instant = Instant.now() ; // Current moment in UTC.

ISO 8601

To exchange this data as text, use the standard ISO 8601 formats exclusively. These formats are sensibly designed to be unambiguous, easy to process by machine, and easy to read across many cultures by people.

The java.time classes use the standard formats by default when parsing and generating strings.

String output = instant.toString() ;  

2017-01-23T12:34:56.123456789Z

Time zone

If you want to see that same moment as presented in the wall-clock time of a particular region, apply a ZoneId to get a ZonedDateTime.

Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 3-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).

ZoneId z = ZoneId.of( "Asia/Singapore" ) ;
ZonedDateTime zdt = instant.atZone( z ) ;  // Same simultaneous moment, same point on the timeline.

See this code live at IdeOne.com.

Notice the eight hour difference, as the time zone of Asia/Singapore currently has an offset-from-UTC of +08:00. Same moment, different wall-clock time.

instant.toString(): 2017-01-23T12:34:56.123456789Z

zdt.toString(): 2017-01-23T20:34:56.123456789+08:00[Asia/Singapore]

Convert

Avoid the legacy java.util.Date class. But if you must, you can convert. Look to new methods added to the old classes.

java.util.Date date = Date.from( instant ) ;

…going the other way…

Instant instant = myJavaUtilDate.toInstant() ;

Date-only

For date-only, use LocalDate.

LocalDate ld = zdt.toLocalDate() ;

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

Where to obtain the java.time classes?

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

how to update the multiple rows at a time using linq to sql?

To update one column here are some syntax options:

Option 1

var ls=new int[]{2,3,4};
using (var db=new SomeDatabaseContext())
{
    var some= db.SomeTable.Where(x=>ls.Contains(x.friendid)).ToList();
    some.ForEach(a=>a.status=true);
    db.SubmitChanges();
}

Option 2

using (var db=new SomeDatabaseContext())
{
     db.SomeTable
       .Where(x=>ls.Contains(x.friendid))
       .ToList()
       .ForEach(a=>a.status=true);

     db.SubmitChanges();
}

Option 3

using (var db=new SomeDatabaseContext())
{
    foreach (var some in db.SomeTable.Where(x=>ls.Contains(x.friendid)).ToList())
    {
        some.status=true;
    }
    db.SubmitChanges();
}

Update

As requested in the comment it might make sense to show how to update multiple columns. So let's say for the purpose of this exercise that we want not just to update the status at ones. We want to update name and status where the friendid is matching. Here are some syntax options for that:

Option 1

var ls=new int[]{2,3,4};
var name="Foo";
using (var db=new SomeDatabaseContext())
{
    var some= db.SomeTable.Where(x=>ls.Contains(x.friendid)).ToList();
    some.ForEach(a=>
                    {
                        a.status=true;
                        a.name=name;
                    }
                );
    db.SubmitChanges();
}

Option 2

using (var db=new SomeDatabaseContext())
{
    db.SomeTable
        .Where(x=>ls.Contains(x.friendid))
        .ToList()
        .ForEach(a=>
                    {
                        a.status=true;
                        a.name=name;
                    }
                );
    db.SubmitChanges();
}

Option 3

using (var db=new SomeDatabaseContext())
{
    foreach (var some in db.SomeTable.Where(x=>ls.Contains(x.friendid)).ToList())
    {
        some.status=true;
        some.name=name;
    }
    db.SubmitChanges();
}

Update 2

In the answer I was using LINQ to SQL and in that case to commit to the database the usage is:

db.SubmitChanges();

But for Entity Framework to commit the changes it is:

db.SaveChanges()

Difference between mkdir() and mkdirs() in java for java.io.File

mkdirs() will create the specified directory path in its entirety where mkdir() will only create the bottom most directory, failing if it can't find the parent directory of the directory it is trying to create.

In other words mkdir() is like mkdir and mkdirs() is like mkdir -p.

For example, imagine we have an empty /tmp directory. The following code

new File("/tmp/one/two/three").mkdirs();

would create the following directories:

  • /tmp/one
  • /tmp/one/two
  • /tmp/one/two/three

Where this code:

new File("/tmp/one/two/three").mkdir();

would not create any directories - as it wouldn't find /tmp/one/two - and would return false.

Chrome says "Resource interpreted as script but transferred with MIME type text/plain.", what gives?

If its IIS make sure That Under your common HTTP Features you have Static Content turned on

How to catch a specific SqlException error?

Sort of, kind of. See Cause and Resolution of Database Engine Errors

class SqllErrorNumbers
{ 
   public const int BadObject = 208;
   public const int DupKey = 2627;
}

try
{
   ...
}
catch(SqlException sex)
{
   foreach(SqlErrorCode err in sex.Errors)
   {
      switch (err.Number)
      {
      case SqlErrorNumber.BadObject:...
      case SqllErrorNumbers.DupKey: ...
      }
   }
}

The problem though is that a good DAL layer would us TRY/CATCH inside the T-SQL (stored procedures), with a pattern like Exception handling and nested transactions. Alas a T-SQL TRY/CATCH block cannot raise the original error code, will have to raise a new error, with code above 50000. This makes client side handling a problem. In the next version of SQL Server there is a new THROW construct that allow to re-raise the original exception from T-SQL catch blocks.

How do SETLOCAL and ENABLEDELAYEDEXPANSION work?

ENABLEDELAYEDEXPANSION is a parameter passed to the SETLOCAL command (look at setlocal /?)

Its effect lives for the duration of the script, or an ENDLOCAL:

When the end of a batch script is reached, an implied ENDLOCAL is executed for any outstanding SETLOCAL commands issued by that batch script.

In particular, this means that if you use SETLOCAL ENABLEDELAYEDEXPANSION in a script, any environment variable changes are lost at the end of it unless you take special measures.

CSS display:table-row does not expand when width is set to 100%

You can nest table-cell directly within table. You muslt have a table. Starting eith table-row does not work. Try it with this HTML:

<html>
  <head>
    <style type="text/css">
.table {
  display: table;
  width: 100%;
}
.tr {
  display: table-row;
  width: 100%;
}
.td {
  display: table-cell;
}
    </style>
  </head>
  <body>

    <div class="table">
      <div class="tr">
        <div class="td">
          X
        </div>
        <div class="td">
          X
        </div>
        <div class="td">
          X
        </div>
      </div>
    </div>

      <div class="tr">
        <div class="td">
          X
        </div>
        <div class="td">
          X
        </div>
        <div class="td">
          X
        </div>
      </div>

    <div class="table">
        <div class="td">
          X
        </div>
        <div class="td">
          X
        </div>
        <div class="td">
          X
        </div>
    </div>

  </body>
</html>

The Definitive C Book Guide and List

Beginner

Introductory, no previous programming experience

  • C++ Primer * (Stanley Lippman, Josée Lajoie, and Barbara E. Moo) (updated for C++11) Coming at 1k pages, this is a very thorough introduction into C++ that covers just about everything in the language in a very accessible format and in great detail. The fifth edition (released August 16, 2012) covers C++11. [Review]

    * Not to be confused with C++ Primer Plus (Stephen Prata), with a significantly less favorable review.

  • Programming: Principles and Practice Using C++ (Bjarne Stroustrup, 2nd Edition - May 25, 2014) (updated for C++11/C++14) An introduction to programming using C++ by the creator of the language. A good read, that assumes no previous programming experience, but is not only for beginners.

Introductory, with previous programming experience

  • A Tour of C++ (Bjarne Stroustrup) (2nd edition for C++17) The “tour” is a quick (about 180 pages and 14 chapters) tutorial overview of all of standard C++ (language and standard library, and using C++11) at a moderately high level for people who already know C++ or at least are experienced programmers. This book is an extended version of the material that constitutes Chapters 2-5 of The C++ Programming Language, 4th edition.

  • Accelerated C++ (Andrew Koenig and Barbara Moo, 1st Edition - August 24, 2000) This basically covers the same ground as the C++ Primer, but does so on a fourth of its space. This is largely because it does not attempt to be an introduction to programming, but an introduction to C++ for people who've previously programmed in some other language. It has a steeper learning curve, but, for those who can cope with this, it is a very compact introduction to the language. (Historically, it broke new ground by being the first beginner's book to use a modern approach to teaching the language.) Despite this, the C++ it teaches is purely C++98. [Review]

Best practices

  • Effective C++ (Scott Meyers, 3rd Edition - May 22, 2005) This was written with the aim of being the best second book C++ programmers should read, and it succeeded. Earlier editions were aimed at programmers coming from C, the third edition changes this and targets programmers coming from languages like Java. It presents ~50 easy-to-remember rules of thumb along with their rationale in a very accessible (and enjoyable) style. For C++11 and C++14 the examples and a few issues are outdated and Effective Modern C++ should be preferred. [Review]

  • Effective Modern C++ (Scott Meyers) This is basically the new version of Effective C++, aimed at C++ programmers making the transition from C++03 to C++11 and C++14.

  • Effective STL (Scott Meyers) This aims to do the same to the part of the standard library coming from the STL what Effective C++ did to the language as a whole: It presents rules of thumb along with their rationale. [Review]


Intermediate

  • More Effective C++ (Scott Meyers) Even more rules of thumb than Effective C++. Not as important as the ones in the first book, but still good to know.

  • Exceptional C++ (Herb Sutter) Presented as a set of puzzles, this has one of the best and thorough discussions of the proper resource management and exception safety in C++ through Resource Acquisition is Initialization (RAII) in addition to in-depth coverage of a variety of other topics including the pimpl idiom, name lookup, good class design, and the C++ memory model. [Review]

  • More Exceptional C++ (Herb Sutter) Covers additional exception safety topics not covered in Exceptional C++, in addition to discussion of effective object-oriented programming in C++ and correct use of the STL. [Review]

  • Exceptional C++ Style (Herb Sutter) Discusses generic programming, optimization, and resource management; this book also has an excellent exposition of how to write modular code in C++ by using non-member functions and the single responsibility principle. [Review]

  • C++ Coding Standards (Herb Sutter and Andrei Alexandrescu) “Coding standards” here doesn't mean “how many spaces should I indent my code?” This book contains 101 best practices, idioms, and common pitfalls that can help you to write correct, understandable, and efficient C++ code. [Review]

  • C++ Templates: The Complete Guide (David Vandevoorde and Nicolai M. Josuttis) This is the book about templates as they existed before C++11. It covers everything from the very basics to some of the most advanced template metaprogramming and explains every detail of how templates work (both conceptually and at how they are implemented) and discusses many common pitfalls. Has excellent summaries of the One Definition Rule (ODR) and overload resolution in the appendices. A second edition covering C++11, C++14 and C++17 has been already published. [Review]

  • C++ 17 - The Complete Guide (Nicolai M. Josuttis) This book describes all the new features introduced in the C++17 Standard covering everything from the simple ones like 'Inline Variables', 'constexpr if' all the way up to 'Polymorphic Memory Resources' and 'New and Delete with overaligned Data'. [Review]

  • C++ in Action (Bartosz Milewski). This book explains C++ and its features by building an application from ground up. [Review]

  • Functional Programming in C++ (Ivan Cukic). This book introduces functional programming techniques to modern C++ (C++11 and later). A very nice read for those who want to apply functional programming paradigms to C++.

  • Professional C++ (Marc Gregoire, 5th Edition - Feb 2021) Provides a comprehensive and detailed tour of the C++ language implementation replete with professional tips and concise but informative in-text examples, emphasizing C++20 features. Uses C++20 features, such as modules and std::format throughout all examples.


Advanced

  • Modern C++ Design (Andrei Alexandrescu) A groundbreaking book on advanced generic programming techniques. Introduces policy-based design, type lists, and fundamental generic programming idioms then explains how many useful design patterns (including small object allocators, functors, factories, visitors, and multi-methods) can be implemented efficiently, modularly, and cleanly using generic programming. [Review]

  • C++ Template Metaprogramming (David Abrahams and Aleksey Gurtovoy)

  • C++ Concurrency In Action (Anthony Williams) A book covering C++11 concurrency support including the thread library, the atomics library, the C++ memory model, locks and mutexes, as well as issues of designing and debugging multithreaded applications. A second edition covering C++14 and C++17 has been already published. [Review]

  • Advanced C++ Metaprogramming (Davide Di Gennaro) A pre-C++11 manual of TMP techniques, focused more on practice than theory. There are a ton of snippets in this book, some of which are made obsolete by type traits, but the techniques, are nonetheless useful to know. If you can put up with the quirky formatting/editing, it is easier to read than Alexandrescu, and arguably, more rewarding. For more experienced developers, there is a good chance that you may pick up something about a dark corner of C++ (a quirk) that usually only comes about through extensive experience.


Reference Style - All Levels

  • The C++ Programming Language (Bjarne Stroustrup) (updated for C++11) The classic introduction to C++ by its creator. Written to parallel the classic K&R, this indeed reads very much like it and covers just about everything from the core language to the standard library, to programming paradigms to the language's philosophy. [Review] Note: All releases of the C++ standard are tracked in the question "Where do I find the current C or C++ standard documents?".

  • C++ Standard Library Tutorial and Reference (Nicolai Josuttis) (updated for C++11) The introduction and reference for the C++ Standard Library. The second edition (released on April 9, 2012) covers C++11. [Review]

  • The C++ IO Streams and Locales (Angelika Langer and Klaus Kreft) There's very little to say about this book except that, if you want to know anything about streams and locales, then this is the one place to find definitive answers. [Review]

C++11/14/17/… References:

  • The C++11/14/17 Standard (INCITS/ISO/IEC 14882:2011/2014/2017) This, of course, is the final arbiter of all that is or isn't C++. Be aware, however, that it is intended purely as a reference for experienced users willing to devote considerable time and effort to its understanding. The C++17 standard is released in electronic form for 198 Swiss Francs.

  • The C++17 standard is available, but seemingly not in an economical form – directly from the ISO it costs 198 Swiss Francs (about $200 US). For most people, the final draft before standardization is more than adequate (and free). Many will prefer an even newer draft, documenting new features that are likely to be included in C++20.

  • Overview of the New C++ (C++11/14) (PDF only) (Scott Meyers) (updated for C++14) These are the presentation materials (slides and some lecture notes) of a three-day training course offered by Scott Meyers, who's a highly respected author on C++. Even though the list of items is short, the quality is high.

  • The C++ Core Guidelines (C++11/14/17/…) (edited by Bjarne Stroustrup and Herb Sutter) is an evolving online document consisting of a set of guidelines for using modern C++ well. The guidelines are focused on relatively higher-level issues, such as interfaces, resource management, memory management and concurrency affecting application architecture and library design. The project was announced at CppCon'15 by Bjarne Stroustrup and others and welcomes contributions from the community. Most guidelines are supplemented with a rationale and examples as well as discussions of possible tool support. Many rules are designed specifically to be automatically checkable by static analysis tools.

  • The C++ Super-FAQ (Marshall Cline, Bjarne Stroustrup and others) is an effort by the Standard C++ Foundation to unify the C++ FAQs previously maintained individually by Marshall Cline and Bjarne Stroustrup and also incorporating new contributions. The items mostly address issues at an intermediate level and are often written with a humorous tone. Not all items might be fully up to date with the latest edition of the C++ standard yet.

  • cppreference.com (C++03/11/14/17/…) (initiated by Nate Kohl) is a wiki that summarizes the basic core-language features and has extensive documentation of the C++ standard library. The documentation is very precise but is easier to read than the official standard document and provides better navigation due to its wiki nature. The project documents all versions of the C++ standard and the site allows filtering the display for a specific version. The project was presented by Nate Kohl at CppCon'14.


Classics / Older

Note: Some information contained within these books may not be up-to-date or no longer considered best practice.

  • The Design and Evolution of C++ (Bjarne Stroustrup) If you want to know why the language is the way it is, this book is where you find answers. This covers everything before the standardization of C++.

  • Ruminations on C++ - (Andrew Koenig and Barbara Moo) [Review]

  • Advanced C++ Programming Styles and Idioms (James Coplien) A predecessor of the pattern movement, it describes many C++-specific “idioms”. It's certainly a very good book and might still be worth a read if you can spare the time, but quite old and not up-to-date with current C++.

  • Large Scale C++ Software Design (John Lakos) Lakos explains techniques to manage very big C++ software projects. Certainly, a good read, if it only was up to date. It was written long before C++ 98 and misses on many features (e.g. namespaces) important for large-scale projects. If you need to work in a big C++ software project, you might want to read it, although you need to take more than a grain of salt with it. The first volume of a new edition is released in 2019.

  • Inside the C++ Object Model (Stanley Lippman) If you want to know how virtual member functions are commonly implemented and how base objects are commonly laid out in memory in a multi-inheritance scenario, and how all this affects performance, this is where you will find thorough discussions of such topics.

  • The Annotated C++ Reference Manual (Bjarne Stroustrup, Margaret A. Ellis) This book is quite outdated in the fact that it explores the 1989 C++ 2.0 version - Templates, exceptions, namespaces and new casts were not yet introduced. Saying that however, this book goes through the entire C++ standard of the time explaining the rationale, the possible implementations, and features of the language. This is not a book to learn programming principles and patterns on C++, but to understand every aspect of the C++ language.

  • Thinking in C++ (Bruce Eckel, 2nd Edition, 2000). Two volumes; is a tutorial style free set of intro level books. Downloads: vol 1, vol 2. Unfortunately they're marred by a number of trivial errors (e.g. maintaining that temporaries are automatically const), with no official errata list. A partial 3rd party errata list is available at http://www.computersciencelab.com/Eckel.htm, but it is apparently not maintained.

  • Scientific and Engineering C++: An Introduction to Advanced Techniques and Examples (John Barton and Lee Nackman) It is a comprehensive and very detailed book that tried to explain and make use of all the features available in C++, in the context of numerical methods. It introduced at the time several new techniques, such as the Curiously Recurring Template Pattern (CRTP, also called Barton-Nackman trick). It pioneered several techniques such as dimensional analysis and automatic differentiation. It came with a lot of compilable and useful code, ranging from an expression parser to a Lapack wrapper. The code is still available online. Unfortunately, the books have become somewhat outdated in the style and C++ features, however, it was an incredible tour-de-force at the time (1994, pre-STL). The chapters on dynamics inheritance are a bit complicated to understand and not very useful. An updated version of this classic book that includes move semantics and the lessons learned from the STL would be very nice.

JPA: How to get entity based on field value other than ID?

All the answers require you to write some sort of SQL/HQL/whatever. Why? You don't have to - just use CriteriaBuilder:

Person.java:

@Entity
class Person  {
  @Id @GeneratedValue
  private int id;

  @Column(name = "name")
  private String name;
  @Column(name = "age")
  private int age;
  ...
}

Dao.java:

public class Dao  {
  public static Person getPersonByName(String name)  {
        SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
        Session session = sessionFactory.openSession();
        session.beginTransaction();

        CriteriaBuilder cb = session.getCriteriaBuilder();

        CriteriaQuery<Person> cr = cb.createQuery(Person.class);
        Root<Person> root = cr.from(Person.class);
        cr.select(root).where(cb.equal(root.get("name"), name));  //here you pass a class field, not a table column (in this example they are called the same)

        Query<Person> query = session.createQuery(cr);
        query.setMaxResults(1);
        List<Person> result = query.getResultList();
        session.close();

        return result.get(0);
  }
}

example of use:

public static void main(String[] args)  {
  Person person = Dao.getPersonByName("John");
  System.out.println(person.getAge());  //John's age
}

Hibernate - A collection with cascade=”all-delete-orphan” was no longer referenced by the owning entity instance

I had the same issue, but it was when the set was null. Only in the Set collection, in List work fine. You can try to the hibernate annotation @LazyCollection(LazyCollectionOption.FALSE) instead of JPA annotation fetch = FetchType.EAGER.

My solution: This is my configuration and work fine

@OneToMany(mappedBy = "format", cascade = CascadeType.ALL, orphanRemoval = true)
@LazyCollection(LazyCollectionOption.FALSE)
private Set<Barcode> barcodes;

@OneToMany(mappedBy = "format", cascade = CascadeType.ALL, orphanRemoval = true)
@LazyCollection(LazyCollectionOption.FALSE)
private List<FormatAdditional> additionals;

How to query nested objects?

Since there is a lot of confusion about queries MongoDB collection with sub-documents, I thought its worth to explain the above answers with examples:

First I have inserted only two objects in the collection namely: message as:

> db.messages.find().pretty()
{
    "_id" : ObjectId("5cce8e417d2e7b3fe9c93c32"),
    "headers" : {
        "From" : "[email protected]"
    }
}
{
    "_id" : ObjectId("5cce8eb97d2e7b3fe9c93c33"),
    "headers" : {
        "From" : "[email protected]",
        "To" : "[email protected]"
    }
}
>

So what is the result of query: db.messages.find({headers: {From: "[email protected]"} }).count()

It should be one because these queries for documents where headers equal to the object {From: "[email protected]"}, only i.e. contains no other fields or we should specify the entire sub-document as the value of a field.

So as per the answer from @Edmondo1984

Equality matches within sub-documents select documents if the subdocument matches exactly the specified sub-document, including the field order.

From the above statements, what is the below query result should be?

> db.messages.find({headers: {To: "[email protected]", From: "[email protected]"}  }).count()
0

And what if we will change the order of From and To i.e same as sub-documents of second documents?

> db.messages.find({headers: {From: "[email protected]", To: "[email protected]"}  }).count()
1

so, it matches exactly the specified sub-document, including the field order.

For using dot operator, I think it is very clear for every one. Let's see the result of below query:

> db.messages.find( { 'headers.From': "[email protected]" }  ).count()
2

I hope these explanations with the above example will make someone more clarity on find query with sub-documents.

iOS start Background Thread

Enable NSZombieEnabled to know which object is being released and then accessed. Then check if the getResultSetFromDB: has anything to do with that. Also check if docids has anything inside and if it is being retained.

This way you can be sure there is nothing wrong.

How to initialize a List<T> to a given size (as opposed to capacity)?

A bit late but first solution you proposed seems far cleaner to me : you dont allocate memory twice. Even List constrcutor needs to loop through array in order to copy it; it doesn't even know by advance there is only null elements inside.

1. - allocate N - loop N Cost: 1 * allocate(N) + N * loop_iteration

2. - allocate N - allocate N + loop () Cost : 2 * allocate(N) + N * loop_iteration

However List's allocation an loops might be faster since List is a built-in class, but C# is jit-compiled sooo...

Does C# have extension properties?

Update (thanks to @chaost for pointing this update out):

Mads Torgersen: "Extension everything didn’t make it into C# 8.0. It got “caught up”, if you will, in a very exciting debate about the further future of the language, and now we want to make sure we don’t add it in a way that inhibits those future possibilities. Sometimes language design is a very long game!"

Source: comments section in https://blogs.msdn.microsoft.com/dotnet/2018/11/12/building-c-8-0/


I stopped counting how many times over the years I opened this question with hopes to have seen this implemented.

Well, finally we can all rejoice! Microsoft is going to introduce this in their upcoming C# 8 release.

So instead of doing this...

public static class IntExtensions
{
   public static bool Even(this int value)
   {
        return value % 2 == 0;
   }
}

We'll be finally able to do it like so...

public extension IntExtension extends int
{
    public bool Even => this % 2 == 0;
}

Source: https://blog.ndepend.com/c-8-0-features-glimpse-future/

Run Button is Disabled in Android Studio

Build->Clean Project

make the run button enable again in my case

Angular 2 / 4 / 5 not working in IE11

The latest version of core-js lib provides the polyfills from a different path. so use the following in the polyfills.js. And also change the target value to es5 in the tsconfig.base.json

/** IE9, IE10 and IE11 requires all of the following polyfills. **/
import 'core-js/es/symbol';
import 'core-js/es/object';
import 'core-js/es/function';
import 'core-js/es/parse-int';
import 'core-js/es/parse-float';
import 'core-js/es/number';
import 'core-js/es/math';
import 'core-js/es/string';
import 'core-js/es/date';
import 'core-js/es/array';
import 'core-js/es/regexp';
import 'core-js/es/map';

Searching multiple files for multiple words

If you are using Notepad++ editor Goto ctrl + F choose tab 3 find in files and enter:

  1. Find What = text1*.*text2
  2. Filters : .
  3. Search mode = Regular Expression
  4. Directory = enter the path of the directory you want to search in. You can check Follow current doc. to have the path of the current file to be filled.

XSLT counting elements with a given value

This XPath:

count(//Property[long = '11007'])

returns the same value as:

count(//Property/long[text() = '11007'])

...except that the first counts Property nodes that match the criterion and the second counts long child nodes that match the criterion.

As per your comment and reading your question a couple of times, I believe that you want to find uniqueness based on a combination of criteria. Therefore, in actuality, I think you are actually checking multiple conditions. The following would work as well:

count(//Property[@Name = 'Alive'][long = '11007'])

because it means the same thing as:

count(//Property[@Name = 'Alive' and long = '11007'])

Of course, you would substitute the values for parameters in your template. The above code only illustrates the point.

EDIT (after question edit)


You were quite right about the XML being horrible. In fact, this is a downright CodingHorror candidate! I had to keep recounting to keep track of the "Property" node I was on presently. I feel your pain!

Here you go:

count(/root/ac/Properties/Property[Properties/Property/Properties/Property/long = $parPropId])

Note that I have removed all the other checks (for ID and Value). They appear not to be required since you are able to arrive at the relevant node using the hierarchy in the XML. Also, you already mentioned that the check for uniqueness is based only on the contents of the long element.

How do I get the picture size with PIL?

You can use Pillow (Website, Documentation, GitHub, PyPI). Pillow has the same interface as PIL, but works with Python 3.

Installation

$ pip install Pillow

If you don't have administrator rights (sudo on Debian), you can use

$ pip install --user Pillow

Other notes regarding the installation are here.

Code

from PIL import Image
with Image.open(filepath) as img:
    width, height = img.size

Speed

This needed 3.21 seconds for 30336 images (JPGs from 31x21 to 424x428, training data from National Data Science Bowl on Kaggle)

This is probably the most important reason to use Pillow instead of something self-written. And you should use Pillow instead of PIL (python-imaging), because it works with Python 3.

Alternative #1: Numpy (deprecated)

I keep scipy.ndimage.imread as the information is still out there, but keep in mind:

imread is deprecated! imread is deprecated in SciPy 1.0.0, and [was] removed in 1.2.0.

import scipy.ndimage
height, width, channels = scipy.ndimage.imread(filepath).shape

Alternative #2: Pygame

import pygame
img = pygame.image.load(filepath)
width = img.get_width()
height = img.get_height()

Run Jquery function on window events: load, resize, and scroll?

just call your function inside the events.

load:

$(document).ready(function(){  // or  $(window).load(function(){
    topInViewport($(mydivname));
});

resize:

$(window).resize(function () {
    topInViewport($(mydivname));
});

scroll:

$(window).scroll(function () {
    topInViewport($(mydivname));
});

or bind all event in one function

$(window).on("load scroll resize",function(e){

Android overlay a view ontop of everything?

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/root_view"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<LinearLayout
    android:id = "@+id/Everything"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <!-- other actual layout stuff here EVERYTHING HERE -->

   </LinearLayout>

<LinearLayout
    android:id="@+id/overlay"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="right" >
</LinearLayout>

Now any view you add under LinearLayout with android:id = "@+id/overlay" will appear as overlay with gravity = right on Linear Layout with android:id="@+id/Everything"

Cannot push to Git repository on Bitbucket

This is probably caused by having multiple SSH keys in SSH agent (and/or BitBucket). Check Atlassian documentation for the workaround for this

Getting the current date in visual Basic 2008

Try this:

Dim regDate as Date = Date.Now()
Dim strDate as String = regDate.ToString("ddMMMyyyy")

strDate will look like so: 07Feb2012

What is process.env.PORT in Node.js?

In many environments (e.g. Heroku), and as a convention, you can set the environment variable PORT to tell your web server what port to listen on.

So process.env.PORT || 3000 means: whatever is in the environment variable PORT, or 3000 if there's nothing there.

So you pass that to app.listen, or to app.set('port', ...), and that makes your server able to accept a "what port to listen on" parameter from the environment.

If you pass 3000 hard-coded to app.listen(), you're always listening on port 3000, which might be just for you, or not, depending on your requirements and the requirements of the environment in which you're running your server.

How to set zoom level in google map

These methods worked for me, it maybe useful for anyone: MapOptions interface

set min zoom: mMap.setMinZoomPreference(N);

set max zoom: mMap.setMaxZoomPreference(N);

where N can equal to:

20 : 1128.497220

19 : 2256.994440

18 : 4513.988880

17 : 9027.977761

16 : 18055.955520

15 : 36111.911040

14 : 72223.822090

13 : 144447.644200

12 : 288895.288400

11 : 577790.576700

10 : 1155581.153000

9 : 2311162.307000

8 : 4622324.614000

7 : 9244649.227000

6 : 18489298.450000

5 : 36978596.910000

4 : 73957193.820000

3 : 147914387.600000

2 : 295828775.300000

1 : 591657550.500000

What is the difference between OFFLINE and ONLINE index rebuild in SQL Server?

In ONLINE mode the new index is built while the old index is accessible to reads and writes. any update on the old index will also get applied to the new index. An antimatter column is used to track possible conflicts between the updates and the rebuild (ie. delete of a row which was not yet copied). See Online Index Operations. When the process is completed the table is locked for a brief period and the new index replaces the old index. If the index contains LOB columns, ONLINE operations are not supported in SQL Server 2005/2008/R2.

In OFFLINE mode the table is locked upfront for any read or write, and then the new index gets built from the old index, while holding a lock on the table. No read or write operation is permitted on the table while the index is being rebuilt. Only when the operation is done is the lock on the table released and reads and writes are allowed again.

Note that in SQL Server 2012 the restriction on LOBs was lifted, see Online Index Operations for indexes containing LOB columns.

Where is virtualenvwrapper.sh after pip install?

Using

find / -name virtualenvwrapper.sh

I got a TON of "permissions denied"s, and exactly one printout of the file location. I missed it until I found that file location when I uninstall/installed it again with pip.

In case you were curious, it was in

/usr/local/share/python/virtualenvwrapper.sh

Launch programs whose path contains spaces

Try:-

Dim objShell
Set objShell = WScript.CreateObject( "WScript.Shell" )
objShell.Run("""c:\Program Files\Mozilla Firefox\firefox.exe""")
Set objShell = Nothing

Note the extra ""s in the string. Since the path to the exe contains spaces it needs to be contained with in quotes. (In this case simply using "firefox.exe" would work).

Also bear in mind that many programs exist in the c:\Program Files (x86) folder on 64 bit versions of Windows.

How to know if a Fragment is Visible?

You should be able to do the following:

MyFragmentClass test = (MyFragmentClass) getSupportFragmentManager().findFragmentByTag("testID");
if (test != null && test.isVisible()) {
     //DO STUFF
}
else {
    //Whatever
}

How to clear PermGen space Error in tomcat

I tried the same on Intellij Ideav11.

It was not picking up the settings after checking the process using grep. In case it does not, give the mem settings for JAVA_OPTS in catalina.sh instead.

How do you create a yes/no boolean field in SQL server?

Sample usage while creating a table:

[ColumnName]     BIT   NULL   DEFAULT 0

Where to place the 'assets' folder in Android Studio?

In android studio you can specify where the source, res, assets folders are located. for each module/app in the build.gradle file you can add something like:

android {
    compileSdkVersion 21
    buildToolsVersion "21.1.1"

    sourceSets {
        main {
            java.srcDirs = ['src']
            assets.srcDirs = ['assets']
            res.srcDirs = ['res']
            manifest.srcFile 'AndroidManifest.xml'
        }
    }
}

how to toggle (hide/show) a table onClick of <a> tag in java script

Try

<script>
  function toggleTable()
    {

    var status = document.getElementById("loginTable").style.display;

    if (status == 'block') {
      document.getElementById("loginTable").style.display="none";
    } else {
      document.getElementById("loginTable").style.display="block";
    }
  }
</script>

Find and replace with sed in directory and sub directories

This worked for me:

find ./ -type f -exec sed -i '' 's#NEEDLE#REPLACEMENT#' *.php {} \;

CSS hide scroll bar, but have element scrollable

work on all major browsers

html {
    overflow: scroll;
    overflow-x: hidden;
}
::-webkit-scrollbar {
    width: 0px;  /* Remove scrollbar space */
    background: transparent;  /* Optional: just make scrollbar invisible */
}

Overcoming "Display forbidden by X-Frame-Options"

Try this thing, i dont think anyone suggested this in the Topic, this will resolve like 70% of your issue, for some other pages, you have to scrap, i have the full solution but not for public,

ADD below to your iframe

sandbox="allow-same-origin allow-scripts allow-popups allow-forms"

How to convert date format to DD-MM-YYYY in C#

The problem is that you're trying to convert a string, so first you should cast your variable to date and after that apply something like
string date = variableConvertedToDate.ToString("dd-MM-yyyy")
or
string date = variableConvertedToDate.ToShortDateString() in this case result is dd/MM/yyyy.

Is it valid to define functions in JSON results?

Leave the quotes off...

var a = {"b":function(){alert('hello world');} };

a.b();

Split string using a newline delimiter with Python

data = """a,b,c
d,e,f
g,h,i
j,k,l"""

print(data.split())       # ['a,b,c', 'd,e,f', 'g,h,i', 'j,k,l']

str.split, by default, splits by all the whitespace characters. If the actual string has any other whitespace characters, you might want to use

print(data.split("\n"))   # ['a,b,c', 'd,e,f', 'g,h,i', 'j,k,l']

Or as @Ashwini Chaudhary suggested in the comments, you can use

print(data.splitlines())

How to open a page in a new window or tab from code-behind

This code works for me:

Dim script As String = "<script type=""text/javascript"">window.open('" & URL.ToString & "');</script>"
ClientScript.RegisterStartupScript(Me.GetType, "openWindow", script)

CSS text-overflow: ellipsis; not working?

text-overflow:ellipsis; only works when the following are true:

  • The element's width must be constrained in px (pixels). Width in % (percentage) won't work.
  • The element must have overflow:hidden and white-space:nowrap set.

The reason you're having problems here is because the width of your a element isn't constrained. You do have a width setting, but because the element is set to display:inline (i.e. the default) it is ignoring it, and nothing else is constraining its width either.

You can fix this by doing one of the following:

  • Set the element to display:inline-block or display:block (probably the former, but depends on your layout needs).
  • Set one of its container elements to display:block and give that element a fixed width or max-width.
  • Set the element to float:left or float:right (probably the former, but again, either should have the same effect as far as the ellipsis is concerned).

I'd suggest display:inline-block, since this will have the minimum collateral impact on your layout; it works very much like the display:inline that it's using currently as far as the layout is concerned, but feel free to experiment with the other points as well; I've tried to give as much info as possible to help you understand how these things interact together; a large part of understanding CSS is about understanding how various styles work together.

Here's a snippet with your code, with a display:inline-block added, to show how close you were.

_x000D_
_x000D_
.app a {_x000D_
  height: 18px;_x000D_
  width: 140px;_x000D_
  padding: 0;_x000D_
  overflow: hidden;_x000D_
  position: relative;_x000D_
  display: inline-block;_x000D_
  margin: 0 5px 0 5px;_x000D_
  text-align: center;_x000D_
  text-decoration: none;_x000D_
  text-overflow: ellipsis;_x000D_
  white-space: nowrap;_x000D_
  color: #000;_x000D_
}
_x000D_
<div class="app">_x000D_
  <a href="">Test Test Test Test Test Test</a>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Useful references:

Swift 3 - Comparing Date objects

As of the time of this writing, Swift natively supports comparing Dates with all comparison operators (i.e. <, <=, ==, >=, and >). You can also compare optional Dates but are limited to <, ==, and >. If you need to compare two optional dates using <= or >=, i.e.

let date1: Date? = ...
let date2: Date? = ...
if date1 >= date2 { ... }

You can overload the <= and >=operators to support optionals:

func <= <T: Comparable>(lhs: T?, rhs: T?) -> Bool {
    return lhs == rhs || lhs < rhs
}

func >= <T: Comparable>(lhs: T?, rhs: T?) -> Bool {
    return lhs == rhs || lhs > rhs
}

Difference between DOM parentNode and parentElement

Use .parentElement and you can't go wrong as long as you aren't using document fragments.

If you use document fragments, then you need .parentNode:

let div = document.createDocumentFragment().appendChild(document.createElement('div'));
div.parentElement // null
div.parentNode // document fragment

Also:

_x000D_
_x000D_
let div = document.getElementById('t').content.firstChild_x000D_
div.parentElement // null_x000D_
div.parentNode // document fragment
_x000D_
<template id="t"><div></div></template>
_x000D_
_x000D_
_x000D_


Apparently the <html>'s .parentNode links to the Document. This should be considered a decision phail as documents aren't nodes since nodes are defined to be containable by documents and documents can't be contained by documents.

Laravel: getting a a single value from a MySQL query

yet another edit: As of version 5.2 pluck is not deprecated anymore, it just got new behaviour (same as lists previously - see side-note below):

edit: As of version 5.1 pluck is deprecated, so start using value instead:

DB::table('users')->where('username', $username)->value('groupName');    

// valid for L4 / L5.0 only
DB::table('users')->where('username', $username)->pluck('groupName');

this will return single value of groupName field of the first row found.


SIDE NOTE reg. @TomasButeler comment: As Laravel doesn't follow sensible versioning, there are sometimes cases like this. At the time of writing this answer we had pluck method to get SINGLE value from the query (Laravel 4.* & 5.0).

Then, with L5.1 pluck got deprecated and, instead, we got value method to replace it.

But to make it funny, pluck in fact was never gone. Instead it just got completely new behaviour and... deprecated lists method.. (L5.2) - that was caused by the inconsistency between Query Builder and Collection methods (in 5.1 pluck worked differently on the collection and query, that's the reason).

invalid conversion from 'const char*' to 'char*'

Well, data.str().c_str() yields a char const* but your function Printfunc() wants to have char*s. Based on the name, it doesn't change the arguments but merely prints them and/or uses them to name a file, in which case you should probably fix your declaration to be

void Printfunc(int a, char const* loc, char const* stream)

The alternative might be to turn the char const* into a char* but fixing the declaration is preferable:

Printfunc(num, addr, const_cast<char*>(data.str().c_str()));

Getting all names in an enum as a String[]

If you can use Java 8, this works nicely (alternative to Yura's suggestion, more efficient):

public static String[] names() {
    return Stream.of(State.values()).map(State::name).toArray(String[]::new);
}

HEAD and ORIG_HEAD in Git

From man 7 gitrevisions:

HEAD names the commit on which you based the changes in the working tree. FETCH_HEAD records the branch which you fetched from a remote repository with your last git fetch invocation. ORIG_HEAD is created by commands that move your HEAD in a drastic way, to record the position of the HEAD before their operation, so that you can easily change the tip of the branch back to the state before you ran them. MERGE_HEAD records the commit(s) which you are merging into your branch when you run git merge. CHERRY_PICK_HEAD records the commit which you are cherry-picking when you run git cherry-pick.

Using pickle.dump - TypeError: must be str, not bytes

The output file needs to be opened in binary mode:

f = open('varstor.txt','w')

needs to be:

f = open('varstor.txt','wb')

Why .NET String is immutable?

string management is an expensive process. keeping strings immutable allows repeated strings to be reused, rather than re-created.

Get push notification while App in foreground iOS

Here is the code to receive Push Notification when app in active state (foreground or open). UNUserNotificationCenter documentation

@available(iOS 10.0, *)
func userNotificationCenter(center: UNUserNotificationCenter, willPresentNotification notification: UNNotification, withCompletionHandler completionHandler: (UNNotificationPresentationOptions) -> Void)
{
     completionHandler([UNNotificationPresentationOptions.Alert,UNNotificationPresentationOptions.Sound,UNNotificationPresentationOptions.Badge])
}

If you need to access userInfo of notification use code: notification.request.content.userInfo

How do you enable mod_rewrite on any OS?

In order to use mod_rewrite you can type the following command in the terminal:

 $ su

 $ passwd **********

 # a2enmod rewrite

Restart apache2 after

 # service apache2 restart

 # /etc/init.d/apache2 restart

or

 # service apache2 restart

How to properly ignore exceptions

For completeness:

>>> def divide(x, y):
...     try:
...         result = x / y
...     except ZeroDivisionError:
...         print("division by zero!")
...     else:
...         print("result is", result)
...     finally:
...         print("executing finally clause")

Also note that you can capture the exception like this:

>>> try:
...     this_fails()
... except ZeroDivisionError as err:
...     print("Handling run-time error:", err)

...and re-raise the exception like this:

>>> try:
...     raise NameError('HiThere')
... except NameError:
...     print('An exception flew by!')
...     raise

...examples from the python tutorial.

XAMPP Apache Webserver localhost not working on MAC OS

try

sudo /Applications/XAMPP/xamppfiles/bin/apachectl start

in terminal

Regex to match 2 digits, optional decimal, two digits

To build on Lee's answer, you need to anchor the expression to satisfy the requirement of not having more than 2 numbers before the decimal.

If each number is a separate string, you can use the string anchors:

^\d{0,2}(\.\d{1,2})?$

If each number is within a string, you can use the word anchors:

\b\d{0,2}(\.\d{1,2})?\b

Convert generic List/Enumerable to DataTable?

If you are using VB.NET then this class does the job.

Imports System.Reflection
''' <summary>
''' Convert any List(Of T) to a DataTable with correct column types and converts Nullable Type values to DBNull
''' </summary>

Public Class ConvertListToDataset

    Public Function ListToDataset(Of T)(ByVal list As IList(Of T)) As DataTable

        Dim dt As New DataTable()
        '/* Create the DataTable columns */
        For Each pi As PropertyInfo In GetType(T).GetProperties()
            If pi.PropertyType.IsValueType Then
                Debug.Print(pi.Name)
            End If
            If IsNothing(Nullable.GetUnderlyingType(pi.PropertyType)) Then
                dt.Columns.Add(pi.Name, pi.PropertyType)
            Else
                dt.Columns.Add(pi.Name, Nullable.GetUnderlyingType(pi.PropertyType))
            End If
        Next

        '/* Populate the DataTable with the values in the Items in List */
        For Each item As T In list
            Dim dr As DataRow = dt.NewRow()
            For Each pi As PropertyInfo In GetType(T).GetProperties()
                dr(pi.Name) = IIf(IsNothing(pi.GetValue(item)), DBNull.Value, pi.GetValue(item))
            Next
            dt.Rows.Add(dr)
        Next
        Return dt

    End Function

End Class

How to remove underline from a link in HTML?

This will remove all underlines from all links:

a {text-decoration: none; }

If you have specific links that you want to apply this to, give them a class name, like nounderline and do this:

a.nounderline {text-decoration: none; }

That will apply only to those links and leave all others unaffected.

This code belongs in the <head> of your document or in a stylesheet:

<head>
    <style type="text/css">
        a.nounderline {text-decoration: none; }
    </style>
</head>

And in the body:

<a href="#" class="nounderline">Link</a>

Array formula on Excel for Mac

Found a solution to Excel Mac2016 as having to paste the code into the relevant cell, enter, then go to the end of the formula within the header bar and enter the following:

Enter a formula as an array formula Image + SHIFT + RETURN or CONTROL + SHIFT + RETURN

Calculate execution time of a SQL query?

You can use

SET STATISTICS TIME { ON | OFF }

Displays the number of milliseconds required to parse, compile, and execute each statement

When SET STATISTICS TIME is ON, the time statistics for a statement are displayed. When OFF, the time statistics are not displayed

USE AdventureWorks2012;  
GO         
SET STATISTICS TIME ON;  
GO  
SELECT ProductID, StartDate, EndDate, StandardCost   
FROM Production.ProductCostHistory  
WHERE StandardCost < 500.00;  
GO  
SET STATISTICS TIME OFF;  
GO  

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at

The use-case for CORS is simple. Imagine the site alice.com has some data that the site bob.com wants to access. This type of request traditionally wouldn’t be allowed under the browser’s same origin policy. However, by supporting CORS requests, alice.com can add a few special response headers that allows bob.com to access the data. In order to understand it well, please visit this nice tutorial.. How to solve the issue of CORS

Remove the legend on a matplotlib figure

you have to add the following lines of code:

ax = gca()
ax.legend_ = None
draw()

gca() returns the current axes handle, and has that property legend_

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

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

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

How do I return JSON without using a template in Django?

In the case of the JSON response there is no template to be rendered. Templates are for generating HTML responses. The JSON is the HTTP response.

However, you can have HTML that is rendered from a template withing your JSON response.

html = render_to_string("some.html", some_dictionary)
serialized_data = simplejson.dumps({"html": html})
return HttpResponse(serialized_data, mimetype="application/json")

System.web.mvc missing

In my case I had all of the proper references in my project. I found that by building the solution the nuget packages were automatically restored.

Java JSON serialization - best practice

Have your tried json-io (https://github.com/jdereg/json-io)?

This library allows you to serialize / deserialize any Java object graph, including object graphs with cycles in them (e.g., A->B, B->A). It does not require your classes to implement any particular interface or inherit from any particular Java class.

In addition to serialization of Java to JSON (and JSON to Java), you can use it to format (pretty print) JSON:

String niceFormattedJson = JsonWriter.formatJson(jsonString)

How do I remove an array item in TypeScript?

Just wanted to add extension method for an array.

interface Array<T> {
      remove(element: T): Array<T>;
    }

    Array.prototype.remove = function (element) {
      const index = this.indexOf(element, 0);
      if (index > -1) {
        return this.splice(index, 1);
      }
      return this;
    };

Can a shell script set environment variables of the calling shell?

Other than writings conditionals depending on what $SHELL/$TERM is set to, no. What's wrong with using Perl? It's pretty ubiquitous (I can't think of a single UNIX variant that doesn't have it), and it'll spare you the trouble.

Why does SSL handshake give 'Could not generate DH keypair' exception?

The "Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files" answer did not work for me but The BouncyCastle's JCE provider suggestion did.

Here are the steps I took using Java 1.6.0_65-b14-462 on Mac OSC 10.7.5

1) Download these jars:

2) move these jars to $JAVA_HOME/lib/ext

3) edit $JAVA_HOME/lib/security/java.security as follows: security.provider.1=org.bouncycastle.jce.provider.BouncyCastleProvider

restart app using JRE and give it a try

How to get last 7 days data from current datetime to last 7 days in sql server

DATEADD and GETDATE functions might not work in MySQL database. so if you are working with MySQL database, then the following command may help you.

select id, NewsHeadline as news_headline,    
NewsText as news_text,    
state, CreatedDate as created_on    
from News    
WHERE CreatedDate>= DATE_ADD(CURDATE(), INTERVAL -3 DAY);

I hope it will help you

Format Instant to String

The Instant class doesn't contain Zone information, it only stores timestamp in milliseconds from UNIX epoch, i.e. 1 Jan 1070 from UTC. So, formatter can't print a date because date always printed for concrete time zone. You should set time zone to formatter and all will be fine, like this :

Instant instant = Instant.ofEpochMilli(92554380000L);
DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.SHORT).withLocale(Locale.UK).withZone(ZoneOffset.UTC);
assert formatter.format(instant).equals("07/12/72 05:33");
assert instant.toString().equals("1972-12-07T05:33:00Z");

javax.validation.ValidationException: HV000183: Unable to load 'javax.el.ExpressionFactory'

Regarding the Hibernate validator documentation page, you have to define a dependency to a JSR-341 implementation:

<dependency>
   <groupId>org.glassfish</groupId>
   <artifactId>javax.el</artifactId>
   <version>3.0.1-b11</version>
</dependency>

Failed to install *.apk on device 'emulator-5554': EOF

you could try this:

   1. Open the "Android Virtual device Manager"
   2. Select from one the listed devices there and run it.
   3. Right click your Android App -> Run As -> Android Application

It worked for me. I tried this on an emulator in eclipse. It takes a while before the app is run. For me it took 33 seconds. Wait until the message in the console says "Success!"

POST request with a simple string in body with Alamofire

If you want to post string as raw body in request

return Alamofire.request(.POST, "http://mywebsite.com/post-request" , parameters: [:], encoding: .Custom({
            (convertible, params) in
            let mutableRequest = convertible.URLRequest.copy() as! NSMutableURLRequest

            let data = ("myBodyString" as NSString).dataUsingEncoding(NSUTF8StringEncoding)
            mutableRequest.HTTPBody = data
            return (mutableRequest, nil)
        }))

jQuery AJAX form using mail() PHP script sends email, but POST data from HTML form is undefined

You are using the wrong parameters name, try:

if($_POST){
    $name = $_POST['name'];
    $email = $_POST['email'];
    $message = $_POST['text'];

//send email
    mail("[email protected]", "51 Deep comment from" .$email, $message);
}

Convert string to decimal number with 2 decimal places in Java

I just want to be sure that the float number will also have 2 decimal places after converting that string.

You can't, because floating point numbers don't have decimal places. They have binary places, which aren't commensurate with decimal places.

If you want decimal places, use a decimal radix.

How to set text color in submit button?

.btn{
    font-size: 20px;
    color:black;
}

Excel Reference To Current Cell

=ADDRESS(ROW(),COLUMN(),4) will give us the relative address of the current cell. =INDIRECT(ADDRESS(ROW(),COLUMN()-1,4)) will give us the contents of the cell left of the current cell =INDIRECT(ADDRESS(ROW()-1,COLUMN(),4)) will give us the contents of the cell above the current cell (great for calculating running totals)

Using CELL() function returns information about the last cell that was changed. So, if we enter a new row or column the CELL() reference will be affected and will not be the current cell's any longer.

Simulate low network connectivity for Android

I know it's an old question but...

Some phones nowadays have a setting to utilize 2G only. It's perfect for simulating slow internet on a real device.

enter image description here

How to pass object from one component to another in Angular 2?

you could also store your data in an service with an setter and get it over a getter

import { Injectable } from '@angular/core';

@Injectable()
export class StorageService {

    public scope: Array<any> | boolean = false;

    constructor() {
    }

    public getScope(): Array<any> | boolean {
        return this.scope;
    }

    public setScope(scope: any): void {
        this.scope = scope;
    }
}

Gson library in Android Studio

Use gradle dependencies to get the Gson in your project. Your application build.gradle should look like this-

dependencies {
  implementation 'com.google.code.gson:gson:2.8.2'
}

Why is this program erroneously rejected by three C++ compilers?

You could try different colors for brackets, maybe some green or red would help ? I think your compiler can't rcognize black ink :P

How to launch an EXE from Web page (asp.net)

How about something like:

<a href="\\DangerServer\Downloads\MyVirusArchive.exe" 
  type="application/octet-stream">Don't download this file!</a>

How to add a single item to a Pandas Series

Adding to joquin's answer the following form might be a bit cleaner (at least nicer to read):

x = p.Series()
N = 4
for i in xrange(N):
   x[i] = i**2

which would produce the same output

also, a bit less orthodox but if you wanted to simply add a single element to the end:

x=p.Series()
value_to_append=5
x[len(x)]=value_to_append

Get integer value of the current year in Java

Use the following code for java 8 :

LocalDate localDate = LocalDate.now();
int year = localDate.getYear();
int month = localDate.getMonthValue();
int date = localDate.getDayOfMonth();

How do you create a Distinct query in HQL

Suppose you have a Customer Entity mapped to CUSTOMER_INFORMATION table and you want to get list of distinct firstName of customer. You can use below snippet to get the same.

Query distinctFirstName = session.createQuery("select ci.firstName from Customer ci group by ci.firstName");
Object [] firstNamesRows = distinctFirstName.list();

I hope it helps. So here we are using group by instead of using distinct keyword.

Also previously I found it difficult to use distinct keyword when I want to apply it to multiple columns. For example I want of get list of distinct firstName, lastName then group by would simply work. I had difficulty in using distinct in this case.

Using SVG as background image

You have set a fixed width and height in your svg tag. This is probably the root of your problem. Try not removing those and set the width and height (if needed) using CSS instead.

Determine the line of code that causes a segmentation fault?

GCC can't do that but GDB (a debugger) sure can. Compile you program using the -g switch, like this:

gcc program.c -g

Then use gdb:

$ gdb ./a.out
(gdb) run
<segfault happens here>
(gdb) backtrace
<offending code is shown here>

Here is a nice tutorial to get you started with GDB.

Where the segfault occurs is generally only a clue as to where "the mistake which causes" it is in the code. The given location is not necessarily where the problem resides.

using lodash .groupBy. how to add your own keys for grouped output?

Here is an updated version using lodash 4 and ES6

const result = _.chain(data)
    .groupBy("color")
    .toPairs()
    .map(pair => _.zipObject(['color', 'users'], pair))
    .value();

Java: Insert multiple rows into MySQL with PreparedStatement

You can create a batch by PreparedStatement#addBatch() and execute it by PreparedStatement#executeBatch().

Here's a kickoff example:

public void save(List<Entity> entities) throws SQLException {
    try (
        Connection connection = database.getConnection();
        PreparedStatement statement = connection.prepareStatement(SQL_INSERT);
    ) {
        int i = 0;

        for (Entity entity : entities) {
            statement.setString(1, entity.getSomeProperty());
            // ...

            statement.addBatch();
            i++;

            if (i % 1000 == 0 || i == entities.size()) {
                statement.executeBatch(); // Execute every 1000 items.
            }
        }
    }
}

It's executed every 1000 items because some JDBC drivers and/or DBs may have a limitation on batch length.

See also:

How to use SharedPreferences in Android to store, fetch and edit values

editor.putString("text", mSaved.getText().toString());

Here, mSaved can be any TextView or EditText from where we can extract a string. you can simply specify a string. Here text will be the key which hold the value obtained from the mSaved (TextView or EditText).

SharedPreferences prefs = this.getSharedPreferences("com.example.app", Context.MODE_PRIVATE);

Also there is no need to save the preference file using the package name i.e., "com.example.app". You can mention your own preferred name. Hope this helps !

Convert pandas DataFrame into list of lists

There is a built in method which would be the fastest method also, calling tolist on the .values np array:

df.values.tolist()

[[0.0, 3.61, 380.0, 3.0],
 [1.0, 3.67, 660.0, 3.0],
 [1.0, 3.19, 640.0, 4.0],
 [0.0, 2.93, 520.0, 4.0]]

How to print colored text to the terminal?

There is also the Python termcolor module. Usage is pretty simple:

from termcolor import colored

print colored('hello', 'red'), colored('world', 'green')

Or in Python 3:

print(colored('hello', 'red'), colored('world', 'green'))

It may not be sophisticated enough, however, for game programming and the "colored blocks" that you want to do...

Check if key exists and iterate the JSON array using Python

If all you want is to check if key exists or not

h = {'a': 1}
'b' in h # returns False

If you want to check if there is a value for key

h.get('b') # returns None

Return a default value if actual value is missing

h.get('b', 'Default value')

Draw path between two points using Google Maps Android API v2

Dont know whether I should put this as answer or not...

I used @Zeeshan0026's solution to draw the path...and the problem was that if I draw path once, and then I do try to draw path once again, both two paths show and this continues...paths showing even when markers were deleted... while, ideally, old paths' shouldn't be there once new path is drawn / markers are deleted..

going through some other question over SO, I had the following solution

I add the following function in Zeeshan's class

 public void clearRoute(){

         for(Polyline line1 : polylines)
         {
             line1.remove();
         }

         polylines.clear();

     }

in my map activity, before drawing the path, I called this function.. example usage as per my app is

private Route rt;

rt.clearRoute();

            if (src == null) {
                Toast.makeText(getApplicationContext(), "Please select your Source", Toast.LENGTH_LONG).show();
            }else if (Destination == null) {
                Toast.makeText(getApplicationContext(), "Please select your Destination", Toast.LENGTH_LONG).show();
            }else if (src.equals(Destination)) {
                Toast.makeText(getApplicationContext(), "Source and Destinatin can not be the same..", Toast.LENGTH_LONG).show();
            }else{

                rt.drawRoute(mMap, MapsMainActivity.this, src,
                        Destination, false, "en");
            }

you can use rt.clearRoute(); as per your requirements.. Hoping that it will save a few minutes of someone else and will help some beginner in solving this issue..

Complete Class Code

see on github

Edit: here is part of code from mainactivity..

case R.id.mkrbtn_set_dest:
                    Destination = selmarker.getPosition();
                    destmarker = selmarker;
                    desShape = createRouteCircle(Destination, false);

                    if (src == null) {
                        Toast.makeText(getApplicationContext(),
                                "Please select your Source first...",
                                Toast.LENGTH_LONG).show();
                    } else if (src.equals(Destination)) {
                        Toast.makeText(getApplicationContext(),
                                "Source and Destinatin can not be the same..",
                                Toast.LENGTH_LONG).show();
                    } else {

                        if (isNetworkAvailable()) {
                            rt.drawRoute(mMap, MapsMainActivity.this, src,
                                    Destination, false, "en");
                            src = null;
                            Destination = null;

                        } else {
                            Toast.makeText(
                                    getApplicationContext(),
                                    "Internet Connection seems to be OFFLINE...!",
                                    Toast.LENGTH_LONG).show();

                        }

                    }

                    break;

Edit 2 as per comments

usage :

//variables as data members
GoogleMap mMap;
private Route rt;
static LatLng src;
static LatLng Destination;
//MapsMainActivity is my activity
//false for interim stops for traffic, google
// en language for html description returned

rt.drawRoute(mMap, MapsMainActivity.this, src,
                            Destination, false, "en");

Decompile Python 2.7 .pyc

UPDATE (2019-04-22) - It sounds like you want to use uncompyle6 nowadays rather than the answers I had mentioned originally.

This sounds like it works: http://code.google.com/p/unpyc/

Issue 8 says it supports 2.7: http://code.google.com/p/unpyc/updates/list

UPDATE (2013-09-03) - As noted in the comments and in other answers, you should look at https://github.com/wibiti/uncompyle2 or https://github.com/gstarnberger/uncompyle instead of unpyc.

Disable Transaction Log

If this is only for dev machines in order to save space then just go with simple recovery mode and you’ll be doing fine.

On production machines though I’d strongly recommend that you keep the databases in full recovery mode. This will ensure you can do point in time recovery if needed.

Also – having databases in full recovery mode can help you to undo accidental updates and deletes by reading transaction log. See below or more details.

How can I rollback an UPDATE query in SQL server 2005?

Read the log file (*.LDF) in sql server 2008

If space is an issue on production machines then just create frequent transaction log backups.

What is the significance of #pragma marks? Why do we need #pragma marks?

#pragma mark - NSSecureCoding

The main purpose of "pragma" is for developer reference.enter image description here

You can easily find a method/Function in a vast thousands of coding lines.

Xcode 11+:

Marker Line in Top

// MARK: - Properties

Marker Line in Top and Bottom

// MARK: - Properties - 

Marker Line only in bottom

// MARK: Properties -

SQL Server add auto increment primary key to existing table

If your table has relationship with other tables using its primary or foriegen key, may be it is impossible to alter your table. so you need to drop and create the table again.
To solve these problems you need to Generate Scripts by right click on the database and in advanced option set type of data to script to scheme and data. after that, using this script with the changing your column to identify and regenerate the table using run its query.
your query will be like here:

USE [Db_YourDbName]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
Drop TABLE [dbo].[Tbl_TourTable]

CREATE TABLE [dbo].[Tbl_TourTable](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [Name] [nvarchar](50) NULL,
    [Family] [nvarchar](150) NULL)  

GO

SET IDENTITY_INSERT [dbo].[Tbl_TourTable] ON 

INSERT [dbo].[Tbl_TourTable] ([ID], [Name], [Family]) VALUES (1,'name 1', 'family 1')
INSERT [dbo].[Tbl_TourTable] ([ID], [Name], [Family]) VALUES (1,'name 1', 'family 1')
INSERT [dbo].[Tbl_TourTable] ([ID], [Name], [Family]) VALUES (1,'name 1', 'family 1')
INSERT [dbo].[Tbl_TourTable] ([ID], [Name], [Family]) VALUES (1,'name 1', 'family 1')
INSERT [dbo].[Tbl_TourTable] ([ID], [Name], [Family]) VALUES (1,'name 1', 'family 1')
INSERT [dbo].[Tbl_TourTable] ([ID], [Name], [Family]) VALUES (1,'name 1', 'family 1')
INSERT [dbo].[Tbl_TourTable] ([ID], [Name], [Family]) VALUES (1,'name 1', 'family 1')

SET IDENTITY_INSERT [dbo].[Tbl_TourTable] off 

Multi value Dictionary

I know this is an old thread, but - since it's not been mentioned this works

  Dictionary<string, object> LookUp = new Dictionary<string, object>();
  LookUp.Add("bob", new { age = "23", height = "2.1m", weight = "110kg"});
  LookUp.Add("jasper", new { age = "33", height = "1.75m", weight = "90kg"});
  foreach(KeyValuePair<string, object> entry in LookUp )
  {
      object person = entry.Value;
      Console.WriteLine("Person name:" + entry.Key + " Age: "  + person.age);          
  }

In c# is there a method to find the max of 3 numbers?

You could try this code:

private float GetBrightestColor(float r, float g, float b) { 
    if (r > g && r > b) {
        return r;
    } else if (g > r && g > b) { 
        return g;
    } else if (b > r && b > g) { 
        return b;
    }
}

JPA Native Query select and cast object

When your native query is based on joins, in that case you can get the result as list of objects and process it.

one simple example.

@Autowired
EntityManager em;

    String nativeQuery = "select name,age from users where id=?";   
    Query query = em.createNativeQuery(nativeQuery);
    query.setParameter(1,id);

    List<Object[]> list = query.getResultList();

    for(Object[] q1 : list){

        String name = q1[0].toString();
        //..
        //do something more on 
     }

Android WebView not loading URL

Just as an alternative solution:

For me webView.getSettings().setUserAgentString("Android WebView") did the trick.

I already had implemented INTERNET permission and WebViewClient as well as WebChromeClient

How to control border height?

I want to control the height of the border. How could I do this?

You can't. CSS borders will always span across the full height / width of the element.

One workaround idea would be to use absolute positioning (which can accept percent values) to place the border-carrying element inside one of the two divs. For that, you would have to make the element position: relative.

HTML for the Pause symbol in audio and video control

▐▐  is HTML and is made with this code: &#9616;&#9616;.

Here's an example JSFiddle.

Convert date from String to Date format in Dataframes

I have personally found some errors in when using unix_timestamp based date converstions from dd-MMM-yyyy format to yyyy-mm-dd, using spark 1.6, but this may extend into recent versions. Below I explain a way to solve the problem using java.time that should work in all versions of spark:

I've seen errors when doing:

from_unixtime(unix_timestamp(StockMarketClosingDate, 'dd-MMM-yyyy'), 'yyyy-MM-dd') as FormattedDate

Below is code to illustrate the error, and my solution to fix it. First I read in stock market data, in a common standard file format:

    import sys.process._
    import org.apache.spark.sql.SQLContext
    import org.apache.spark.sql.functions.udf
    import org.apache.spark.sql.types.{StructType, StructField, StringType, IntegerType, DateType}
    import sqlContext.implicits._

    val EODSchema = StructType(Array(
        StructField("Symbol"                , StringType, true),     //$1       
        StructField("Date"                  , StringType, true),     //$2       
        StructField("Open"                  , StringType, true),     //$3       
        StructField("High"                  , StringType, true),     //$4
        StructField("Low"                   , StringType, true),     //$5
        StructField("Close"                 , StringType, true),     //$6
        StructField("Volume"                , StringType, true)      //$7
        ))

    val textFileName = "/user/feeds/eoddata/INDEX/INDEX_19*.csv"

    // below is code to read using later versions of spark
    //val eoddata = spark.read.format("csv").option("sep", ",").schema(EODSchema).option("header", "true").load(textFileName)


    // here is code to read using 1.6, via, "com.databricks:spark-csv_2.10:1.2.0"

    val eoddata = sqlContext.read
                               .format("com.databricks.spark.csv")
                               .option("header", "true")                               // Use first line of all files as header
                               .option("delimiter", ",")                               //.option("dateFormat", "dd-MMM-yyyy") failed to work
                               .schema(EODSchema)
                               .load(textFileName)

    eoddata.registerTempTable("eoddata")

And here is the date conversions having issues:

%sql 
-- notice there are errors around the turn of the year
Select 
    e.Date as StringDate
,   cast(from_unixtime(unix_timestamp(e.Date, "dd-MMM-yyyy"), 'YYYY-MM-dd') as Date)  as ProperDate
,   e.Close
from eoddata e
where e.Symbol = 'SPX.IDX'
order by cast(from_unixtime(unix_timestamp(e.Date, "dd-MMM-yyyy"), 'YYYY-MM-dd') as Date)
limit 1000

A chart made in zeppelin shows spikes, which are errors.

Errors in date conversion seen as spikes

and here is the check that shows the date conversion errors:

// shows the unix_timestamp conversion approach can create errors
val result =  sqlContext.sql("""
Select errors.* from
(
    Select 
    t.*
    , substring(t.OriginalStringDate, 8, 11) as String_Year_yyyy 
    , substring(t.ConvertedCloseDate, 0, 4)  as Converted_Date_Year_yyyy
    from
    (        Select
                Symbol
            ,   cast(from_unixtime(unix_timestamp(e.Date, "dd-MMM-yyyy"), 'YYYY-MM-dd') as Date)  as ConvertedCloseDate
            ,   e.Date as OriginalStringDate
            ,   Close
            from eoddata e
            where e.Symbol = 'SPX.IDX'
    ) t 
) errors
where String_Year_yyyy <> Converted_Date_Year_yyyy
""")


//df.withColumn("tx_date", to_date(unix_timestamp($"date", "M/dd/yyyy").cast("timestamp")))


result.registerTempTable("SPX")
result.cache()
result.show(100)
result: org.apache.spark.sql.DataFrame = [Symbol: string, ConvertedCloseDate: date, OriginalStringDate: string, Close: string, String_Year_yyyy: string, Converted_Date_Year_yyyy: string]
res53: result.type = [Symbol: string, ConvertedCloseDate: date, OriginalStringDate: string, Close: string, String_Year_yyyy: string, Converted_Date_Year_yyyy: string]
+-------+------------------+------------------+-------+----------------+------------------------+
| Symbol|ConvertedCloseDate|OriginalStringDate|  Close|String_Year_yyyy|Converted_Date_Year_yyyy|
+-------+------------------+------------------+-------+----------------+------------------------+
|SPX.IDX|        1997-12-30|       30-Dec-1996| 753.85|            1996|                    1997|
|SPX.IDX|        1997-12-31|       31-Dec-1996| 740.74|            1996|                    1997|
|SPX.IDX|        1998-12-29|       29-Dec-1997| 953.36|            1997|                    1998|
|SPX.IDX|        1998-12-30|       30-Dec-1997| 970.84|            1997|                    1998|
|SPX.IDX|        1998-12-31|       31-Dec-1997| 970.43|            1997|                    1998|
|SPX.IDX|        1998-01-01|       01-Jan-1999|1229.23|            1999|                    1998|
+-------+------------------+------------------+-------+----------------+------------------------+
FINISHED   

After this result, I switched to java.time conversions with a UDF like this, which worked for me:

// now we will create a UDF that uses the very nice java.time library to properly convert the silly stockmarket dates
// start by importing the specific java.time libraries that superceded the joda.time ones
import java.time.LocalDate
import java.time.format.DateTimeFormatter

// now define a specific data conversion function we want

def fromEODDate (YourStringDate: String): String = {

    val formatter = DateTimeFormatter.ofPattern("dd-MMM-yyyy")
    var   retDate = LocalDate.parse(YourStringDate, formatter)

    // this should return a proper yyyy-MM-dd date from the silly dd-MMM-yyyy formats
    // now we format this true local date with a formatter to the desired yyyy-MM-dd format

    val retStringDate = retDate.format(DateTimeFormatter.ISO_LOCAL_DATE)
    return(retStringDate)
}

Now I register it as a function for use in sql:

sqlContext.udf.register("fromEODDate", fromEODDate(_:String))

and check the results, and rerun test:

val results = sqlContext.sql("""
    Select
        e.Symbol    as Symbol
    ,   e.Date      as OrigStringDate
    ,   Cast(fromEODDate(e.Date) as Date) as ConvertedDate
    ,   e.Open
    ,   e.High
    ,   e.Low
    ,   e.Close
    from eoddata e
    order by Cast(fromEODDate(e.Date) as Date)
""")

results.printSchema()
results.cache()
results.registerTempTable("results")
results.show(10)
results: org.apache.spark.sql.DataFrame = [Symbol: string, OrigStringDate: string, ConvertedDate: date, Open: string, High: string, Low: string, Close: string]
root
 |-- Symbol: string (nullable = true)
 |-- OrigStringDate: string (nullable = true)
 |-- ConvertedDate: date (nullable = true)
 |-- Open: string (nullable = true)
 |-- High: string (nullable = true)
 |-- Low: string (nullable = true)
 |-- Close: string (nullable = true)
res79: results.type = [Symbol: string, OrigStringDate: string, ConvertedDate: date, Open: string, High: string, Low: string, Close: string]
+--------+--------------+-------------+-------+-------+-------+-------+
|  Symbol|OrigStringDate|ConvertedDate|   Open|   High|    Low|  Close|
+--------+--------------+-------------+-------+-------+-------+-------+
|ADVA.IDX|   01-Jan-1996|   1996-01-01|    364|    364|    364|    364|
|ADVN.IDX|   01-Jan-1996|   1996-01-01|   1527|   1527|   1527|   1527|
|ADVQ.IDX|   01-Jan-1996|   1996-01-01|   1283|   1283|   1283|   1283|
|BANK.IDX|   01-Jan-1996|   1996-01-01|1009.41|1009.41|1009.41|1009.41|
| BKX.IDX|   01-Jan-1996|   1996-01-01|  39.39|  39.39|  39.39|  39.39|
|COMP.IDX|   01-Jan-1996|   1996-01-01|1052.13|1052.13|1052.13|1052.13|
| CPR.IDX|   01-Jan-1996|   1996-01-01|  1.261|  1.261|  1.261|  1.261|
|DECA.IDX|   01-Jan-1996|   1996-01-01|    205|    205|    205|    205|
|DECN.IDX|   01-Jan-1996|   1996-01-01|    825|    825|    825|    825|
|DECQ.IDX|   01-Jan-1996|   1996-01-01|    754|    754|    754|    754|
+--------+--------------+-------------+-------+-------+-------+-------+
only showing top 10 rows

which looks ok, and I rerun my chart, to see if there are errors/spikes:

enter image description here

As you can see, no more spikes or errors. I now use a UDF as I've shown to apply my date format transformations to a standard yyyy-MM-dd format, and have not had spurious errors since. :-)

Creating a data frame from two vectors using cbind

Vectors and matrices can only be of a single type and cbind and rbind on vectors will give matrices. In these cases, the numeric values will be promoted to character values since that type will hold all the values.

(Note that in your rbind example, the promotion happens within the c call:

> c(10, "[]", "[[1,2]]")
[1] "10"      "[]"      "[[1,2]]"

If you want a rectangular structure where the columns can be different types, you want a data.frame. Any of the following should get you what you want:

> x = data.frame(v1=c(10, 20), v2=c("[]", "[]"), v3=c("[[1,2]]","[[1,3]]"))
> x
  v1 v2      v3
1 10 [] [[1,2]]
2 20 [] [[1,3]]
> str(x)
'data.frame':   2 obs. of  3 variables:
 $ v1: num  10 20
 $ v2: Factor w/ 1 level "[]": 1 1
 $ v3: Factor w/ 2 levels "[[1,2]]","[[1,3]]": 1 2

or (using specifically the data.frame version of cbind)

> x = cbind.data.frame(c(10, 20), c("[]", "[]"), c("[[1,2]]","[[1,3]]"))
> x
  c(10, 20) c("[]", "[]") c("[[1,2]]", "[[1,3]]")
1        10            []                 [[1,2]]
2        20            []                 [[1,3]]
> str(x)
'data.frame':   2 obs. of  3 variables:
 $ c(10, 20)              : num  10 20
 $ c("[]", "[]")          : Factor w/ 1 level "[]": 1 1
 $ c("[[1,2]]", "[[1,3]]"): Factor w/ 2 levels "[[1,2]]","[[1,3]]": 1 2

or (using cbind, but making the first a data.frame so that it combines as data.frames do):

> x = cbind(data.frame(c(10, 20)), c("[]", "[]"), c("[[1,2]]","[[1,3]]"))
> x
  c.10..20. c("[]", "[]") c("[[1,2]]", "[[1,3]]")
1        10            []                 [[1,2]]
2        20            []                 [[1,3]]
> str(x)
'data.frame':   2 obs. of  3 variables:
 $ c.10..20.              : num  10 20
 $ c("[]", "[]")          : Factor w/ 1 level "[]": 1 1
 $ c("[[1,2]]", "[[1,3]]"): Factor w/ 2 levels "[[1,2]]","[[1,3]]": 1 2

How do I show running processes in Oracle DB?

Keep in mind that there are processes on the database which may not currently support a session.

If you're interested in all processes you'll want to look to v$process (or gv$process on RAC)

Spring Data JPA and Exists query

You can use .exists (return boolean) in jpaRepository.

if(commercialRuleMsisdnRepo.exists(commercialRuleMsisdn.getRuleId())!=true){

        jsRespon.setStatusDescription("SUCCESS ADD TO DB");
    }else{
        jsRespon.setStatusCode("ID already exists is database");
    }

fatal: Not a valid object name: 'master'

copying Superfly Jon's comment into an answer:

To create a new branch without committing on master, you can use:

git checkout -b <branchname>

Getting android.content.res.Resources$NotFoundException: exception even when the resource is present in android

This can happen due to a different language in the phone for which your code doesn't have the asset for. For example your preference.xml is placed in xml-en and you are trying to run your app in a phone which has French selected, the app will crash.

Space between border and content? / Border distance from content?

Add padding. Padding the element will increase the space between its content and its border. However, note that a box-shadow will begin outside the border, not the content, meaning you can't put space between the shadow and the box. Alternatively you could use :before or :after pseudo selectors on the element to create a slightly bigger box that you place the shadow on, like so: http://jsbin.com/aqemew/edit#source

Boolean Field in Oracle

Either 1/0 or Y/N with a check constraint on it. ether way is fine. I personally prefer 1/0 as I do alot of work in perl, and it makes it really easy to do perl Boolean operations on database fields.

If you want a really in depth discussion of this question with one of Oracles head honchos, check out what Tom Kyte has to say about this Here

What is the "__v" field in Mongoose

We can use versionKey: false in Schema definition

'use strict';

const mongoose = require('mongoose');

export class Account extends mongoose.Schema {

    constructor(manager) {

        var trans = {
            tran_date: Date,
            particulars: String,
            debit: Number,
            credit: Number,
            balance: Number
        }

        super({
            account_number: Number,
            account_name: String,
            ifsc_code: String,
            password: String,
            currency: String,
            balance: Number,
            beneficiaries: Array,
            transaction: [trans]
        }, {
            versionKey: false // set to false then it wont create in mongodb
        });

        this.pre('remove', function(next) {
            manager
                .getModel(BENEFICIARY_MODEL)
                .remove({
                    _id: {
                        $in: this.beneficiaries
                    }
                })
                .exec();
            next();
        });
    }

}

How to change value for innodb_buffer_pool_size in MySQL on Mac OS?

I had to put the statement under the [mysqld] block to make it work. Otherwise the change was not reflected. I have a REL distribution.

What causes imported Maven project in Eclipse to use Java 1.5 instead of Java 1.6 by default and how can I ensure it doesn't?

One more possible reason if you are using Tycho and Maven to build bundles, that you have wrong execution environment (Bundle-RequiredExecutionEnvironment) in the manifest file (manifest.mf) defined. For example:

Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: Engine Plug-in
Bundle-SymbolicName: com.foo.bar
Bundle-Version: 4.6.5.qualifier
Bundle-Activator: com.foo.bar.Activator
Bundle-Vendor: Foobar Technologies Ltd.
Require-Bundle: org.eclipse.core.runtime,
 org.jdom;bundle-version="1.0.0",
 org.apache.commons.codec;bundle-version="1.3.0",
 bcprov-ext;bundle-version="1.47.0"
Bundle-RequiredExecutionEnvironment: JavaSE-1.5
Export-Package: ...
...
Import-Package: ...
...

In my case everything else was ok. The compiler plugins (normal maven and tycho as well) were set correctly, still m2 generated old compliance level because of the manifest. I thought I share the experience.

How do you cache an image in Javascript

I always prefer to use the example mentioned in Konva JS: Image Events to load images.

  1. You need to have a list of image URLs as object or array, for example:

    var sources = { lion: '/assets/lion.png', monkey: '/assets/monkey.png' };

  2. Define the Function definition, where it receives list of image URLs and a callback function in its arguments list, so when it finishes loading image you can start excution on your web page:

_x000D_
_x000D_
    function loadImages(sources, callback) {_x000D_
                var images = {};_x000D_
                var loadedImages = 0;_x000D_
                var numImages = 0;_x000D_
                for (var src in sources) {_x000D_
                    numImages++;_x000D_
                }_x000D_
                for (var src in sources) {_x000D_
                    images[src] = new Image();_x000D_
                    images[src].onload = function () {_x000D_
                        if (++loadedImages >= numImages) {_x000D_
                            callback(images);_x000D_
                        }_x000D_
                    };_x000D_
                    images[src].src = sources[src];_x000D_
                }_x000D_
            }
_x000D_
_x000D_
_x000D_

  1. Lastly, you need to call the function. You can call it for example from jQuery's Document Ready

$(document).ready(function (){ loadImages(sources, buildStage); });

enum Values to NSString (iOS)

Suppose requirement is to enumerate list of languages.

Add this to .h file

typedef NS_ENUM(NSInteger, AvailableLanguage) {
  ENGLISH,
  GERMAN,
  CHINENSE
};

Now, in .m file simply create an array like,

// Try to use the same naming convention throughout. 
// That is, adding ToString after NS_ENUM name;

NSString* const AvailableLanguageToString[] = {
  [ENGLISH] = @"English",
  [GERMAN]  = @"German",
  [CHINESE] = @"Chinese"
};

Thats it. Now you can use enum with easy and get string for enums using array. For example,

- (void) setPreferredLanguage:(AvailableLanguage)language {
  // this will get the NSString* for the language.
  self.preferredLanguage = AvailableLanguageToString[language];
}

Thus, this pattern depends on accepted naming convention of NS_ENUM and companion ToString array. Try to follow this convention through out and it will become natural.

How to var_dump variables in twig templates?

So I got it working, partly a bit hackish:

  1. Set twig: debug: 1 in app/config/config.yml
  2. Add this to config_dev.yml

    services:
        debug.twig.extension:
            class: Twig_Extensions_Extension_Debug
            tags: [{ name: 'twig.extension' }]
    
  3. sudo rm -fr app/cache/dev

  4. To use my own debug function instead of print_r(), I opened vendor/twig-extensions/lib/Twig/Extensions/Node/Debug.php and changed print_r( to d(

PS. I would still like to know how/where to grab the $twig environment to add filters and extensions.

How to replace all spaces in a string

VERY EASY:

just use this to replace all white spaces with -:

myString.replace(/ /g,"-")

How to measure time in milliseconds using ANSI C?

Implementing a portable solution

As it was already mentioned here that there is no proper ANSI solution with sufficient precision for the time measurement problem, I want to write about the ways how to get a portable and, if possible, a high-resolution time measurement solution.

Monotonic clock vs. time stamps

Generally speaking there are two ways of time measurement:

  • monotonic clock;
  • current (date)time stamp.

The first one uses a monotonic clock counter (sometimes it is called a tick counter) which counts ticks with a predefined frequency, so if you have a ticks value and the frequency is known, you can easily convert ticks to elapsed time. It is actually not guaranteed that a monotonic clock reflects the current system time in any way, it may also count ticks since a system startup. But it guarantees that a clock is always run up in an increasing fashion regardless of the system state. Usually the frequency is bound to a hardware high-resolution source, that's why it provides a high accuracy (depends on hardware, but most of the modern hardware has no problems with high-resolution clock sources).

The second way provides a (date)time value based on the current system clock value. It may also have a high resolution, but it has one major drawback: this kind of time value can be affected by different system time adjustments, i.e. time zone change, daylight saving time (DST) change, NTP server update, system hibernation and so on. In some circumstances you can get a negative elapsed time value which can lead to an undefined behavior. Actually this kind of time source is less reliable than the first one.

So the first rule in time interval measuring is to use a monotonic clock if possible. It usually has a high precision, and it is reliable by design.

Fallback strategy

When implementing a portable solution it is worth to consider a fallback strategy: use a monotonic clock if available and fallback to time stamps approach if there is no monotonic clock in the system.

Windows

There is a great article called Acquiring high-resolution time stamps on MSDN about time measurement on Windows which describes all the details you may need to know about software and hardware support. To acquire a high precision time stamp on Windows you should:

  • query a timer frequency (ticks per second) with QueryPerformanceFrequency:

    LARGE_INTEGER tcounter;
    LARGE_INTEGER freq;    
    
    if (QueryPerformanceFrequency (&tcounter) != 0)
        freq = tcounter.QuadPart;
    

    The timer frequency is fixed on the system boot so you need to get it only once.

  • query the current ticks value with QueryPerformanceCounter:

    LARGE_INTEGER tcounter;
    LARGE_INTEGER tick_value;
    
    if (QueryPerformanceCounter (&tcounter) != 0)
        tick_value = tcounter.QuadPart;
    
  • scale the ticks to elapsed time, i.e. to microseconds:

    LARGE_INTEGER usecs = (tick_value - prev_tick_value) / (freq / 1000000);
    

According to Microsoft you should not have any problems with this approach on Windows XP and later versions in most cases. But you can also use two fallback solutions on Windows:

  • GetTickCount provides the number of milliseconds that have elapsed since the system was started. It wraps every 49.7 days, so be careful in measuring longer intervals.
  • GetTickCount64 is a 64-bit version of GetTickCount, but it is available starting from Windows Vista and above.

OS X (macOS)

OS X (macOS) has its own Mach absolute time units which represent a monotonic clock. The best way to start is the Apple's article Technical Q&A QA1398: Mach Absolute Time Units which describes (with the code examples) how to use Mach-specific API to get monotonic ticks. There is also a local question about it called clock_gettime alternative in Mac OS X which at the end may leave you a bit confused what to do with the possible value overflow because the counter frequency is used in the form of numerator and denominator. So, a short example how to get elapsed time:

  • get the clock frequency numerator and denominator:

    #include <mach/mach_time.h>
    #include <stdint.h>
    
    static uint64_t freq_num   = 0;
    static uint64_t freq_denom = 0;
    
    void init_clock_frequency ()
    {
        mach_timebase_info_data_t tb;
    
        if (mach_timebase_info (&tb) == KERN_SUCCESS && tb.denom != 0) {
            freq_num   = (uint64_t) tb.numer;
            freq_denom = (uint64_t) tb.denom;
        }
    }
    

    You need to do that only once.

  • query the current tick value with mach_absolute_time:

    uint64_t tick_value = mach_absolute_time ();
    
  • scale the ticks to elapsed time, i.e. to microseconds, using previously queried numerator and denominator:

    uint64_t value_diff = tick_value - prev_tick_value;
    
    /* To prevent overflow */
    value_diff /= 1000;
    
    value_diff *= freq_num;
    value_diff /= freq_denom;
    

    The main idea to prevent an overflow is to scale down the ticks to desired accuracy before using the numerator and denominator. As the initial timer resolution is in nanoseconds, we divide it by 1000 to get microseconds. You can find the same approach used in Chromium's time_mac.c. If you really need a nanosecond accuracy consider reading the How can I use mach_absolute_time without overflowing?.

Linux and UNIX

The clock_gettime call is your best way on any POSIX-friendly system. It can query time from different clock sources, and the one we need is CLOCK_MONOTONIC. Not all systems which have clock_gettime support CLOCK_MONOTONIC, so the first thing you need to do is to check its availability:

  • if _POSIX_MONOTONIC_CLOCK is defined to a value >= 0 it means that CLOCK_MONOTONIC is avaiable;
  • if _POSIX_MONOTONIC_CLOCK is defined to 0 it means that you should additionally check if it works at runtime, I suggest to use sysconf:

    #include <unistd.h>
    
    #ifdef _SC_MONOTONIC_CLOCK
    if (sysconf (_SC_MONOTONIC_CLOCK) > 0) {
        /* A monotonic clock presents */
    }
    #endif
    
  • otherwise a monotonic clock is not supported and you should use a fallback strategy (see below).

Usage of clock_gettime is pretty straight forward:

  • get the time value:

    #include <time.h>
    #include <sys/time.h>
    #include <stdint.h>
    
    uint64_t get_posix_clock_time ()
    {
        struct timespec ts;
    
        if (clock_gettime (CLOCK_MONOTONIC, &ts) == 0)
            return (uint64_t) (ts.tv_sec * 1000000 + ts.tv_nsec / 1000);
        else
            return 0;
    }
    

    I've scaled down the time to microseconds here.

  • calculate the difference with the previous time value received the same way:

    uint64_t prev_time_value, time_value;
    uint64_t time_diff;
    
    /* Initial time */
    prev_time_value = get_posix_clock_time ();
    
    /* Do some work here */
    
    /* Final time */
    time_value = get_posix_clock_time ();
    
    /* Time difference */
    time_diff = time_value - prev_time_value;
    

The best fallback strategy is to use the gettimeofday call: it is not a monotonic, but it provides quite a good resolution. The idea is the same as with clock_gettime, but to get a time value you should:

#include <time.h>
#include <sys/time.h>
#include <stdint.h>

uint64_t get_gtod_clock_time ()
{
    struct timeval tv;

    if (gettimeofday (&tv, NULL) == 0)
        return (uint64_t) (tv.tv_sec * 1000000 + tv.tv_usec);
    else
        return 0;
}

Again, the time value is scaled down to microseconds.

SGI IRIX

IRIX has the clock_gettime call, but it lacks CLOCK_MONOTONIC. Instead it has its own monotonic clock source defined as CLOCK_SGI_CYCLE which you should use instead of CLOCK_MONOTONIC with clock_gettime.

Solaris and HP-UX

Solaris has its own high-resolution timer interface gethrtime which returns the current timer value in nanoseconds. Though the newer versions of Solaris may have clock_gettime, you can stick to gethrtime if you need to support old Solaris versions.

Usage is simple:

#include <sys/time.h>

void time_measure_example ()
{
    hrtime_t prev_time_value, time_value;
    hrtime_t time_diff;

    /* Initial time */
    prev_time_value = gethrtime ();

    /* Do some work here */

    /* Final time */
    time_value = gethrtime ();

    /* Time difference */
    time_diff = time_value - prev_time_value;
}

HP-UX lacks clock_gettime, but it supports gethrtime which you should use in the same way as on Solaris.

BeOS

BeOS also has its own high-resolution timer interface system_time which returns the number of microseconds have elapsed since the computer was booted.

Example usage:

#include <kernel/OS.h>

void time_measure_example ()
{
    bigtime_t prev_time_value, time_value;
    bigtime_t time_diff;

    /* Initial time */
    prev_time_value = system_time ();

    /* Do some work here */

    /* Final time */
    time_value = system_time ();

    /* Time difference */
    time_diff = time_value - prev_time_value;
}

OS/2

OS/2 has its own API to retrieve high-precision time stamps:

  • query a timer frequency (ticks per unit) with DosTmrQueryFreq (for GCC compiler):

    #define INCL_DOSPROFILE
    #define INCL_DOSERRORS
    #include <os2.h>
    #include <stdint.h>
    
    ULONG freq;
    
    DosTmrQueryFreq (&freq);
    
  • query the current ticks value with DosTmrQueryTime:

    QWORD    tcounter;
    unit64_t time_low;
    unit64_t time_high;
    unit64_t timestamp;
    
    if (DosTmrQueryTime (&tcounter) == NO_ERROR) {
        time_low  = (unit64_t) tcounter.ulLo;
        time_high = (unit64_t) tcounter.ulHi;
    
        timestamp = (time_high << 32) | time_low;
    }
    
  • scale the ticks to elapsed time, i.e. to microseconds:

    uint64_t usecs = (prev_timestamp - timestamp) / (freq / 1000000);
    

Example implementation

You can take a look at the plibsys library which implements all the described above strategies (see ptimeprofiler*.c for details).

The SQL OVER() clause - when and why is it useful?

If you only wanted to GROUP BY the SalesOrderID then you wouldn't be able to include the ProductID and OrderQty columns in the SELECT clause.

The PARTITION BY clause let's you break up your aggregate functions. One obvious and useful example would be if you wanted to generate line numbers for order lines on an order:

SELECT
    O.order_id,
    O.order_date,
    ROW_NUMBER() OVER(PARTITION BY O.order_id) AS line_item_no,
    OL.product_id
FROM
    Orders O
INNER JOIN Order_Lines OL ON OL.order_id = O.order_id

(My syntax might be off slightly)

You would then get back something like:

order_id    order_date    line_item_no    product_id
--------    ----------    ------------    ----------
    1       2011-05-02         1              5
    1       2011-05-02         2              4
    1       2011-05-02         3              7
    2       2011-05-12         1              8
    2       2011-05-12         2              1

Bootstrap button - remove outline on Chrome OS X

.btn:focus, .btn:active:focus, .btn.active:focus{
    outline:none;
    box-shadow:none;
}

This should remove outline and box shadow

Java Strings: "String s = new String("silly");"

CaseInsensitiveString is not a String although it contains a String. A String literal e.g "example" can be only assigned to a String.

java.util.Date format conversion yyyy-mm-dd to mm-dd-yyyy

'M' (Capital) represent month & 'm' (Simple) represent minutes

Some example for months

'M' -> 7  (without prefix 0 if it is single digit)
'M' -> 12

'MM' -> 07 (with prefix 0 if it is single digit)
'MM' -> 12

'MMM' -> Jul (display with 3 character)

'MMMM' -> December (display with full name)

Some example for minutes

'm' -> 3  (without prefix 0 if it is single digit)
'm' -> 19
'mm' -> 03 (with prefix 0 if it is single digit)
'mm' -> 19

How to use Fiddler to monitor WCF service

Consolidating the caveats mentioned in comments/answers for several use cases.

Mostly, see http://docs.telerik.com/fiddler/Configure-Fiddler/Tasks/ConfigureDotNETApp

  • Start Fiddler before your app
  • In a console app, you might not need to specify the proxyaddress:

    <proxy bypassonlocal="False" usesystemdefault="True" />
    
  • In a web application / something hosted in IIS, you need to add the proxyaddress:

    <proxy bypassonlocal="False" usesystemdefault="True" proxyaddress="http://127.0.0.1:8888" />
    
  • When .NET makes a request (through a service client or HttpWebRequest, etc) it will always bypass the Fiddler proxy for URLs containing localhost, so you must use an alias like the machine name or make up something in your 'hosts' file (which is why something like localhost.fiddler or http://HOSTNAME works)
  • If you specify the proxyaddress, you must remove it from your config if Fiddler isn't on, or any requests your app makes will throw an exception like:

    No connection could be made because the target machine actively refused it 127.0.0.1:8888

  • Don't forget to use config transformations to remove the proxy section in production

How do I upload a file to an SFTP server in C# (.NET)?

Unfortunately, it's not in the .NET Framework itself. My wish is that you could integrate with FileZilla, but I don't think it exposes an interface. They do have scripting I think, but it won't be as clean obviously.

I've used CuteFTP in a project which does SFTP. It exposes a COM component which I created a .NET wrapper around. The catch, you'll find, is permissions. It runs beautifully under the Windows credentials which installed CuteFTP, but running under other credentials requires permissions to be set in DCOM.

How to use andWhere and orWhere in Doctrine?

$q->where("a = 1")
  ->andWhere("b = 1 OR b = 2")
  ->andWhere("c = 2 OR c = 2")
  ;

jQuery select2 get value of select tag?

$(".element").select2(/*Your code*/)
.on('change', function (e) {
     var getID = $(this).select2('data');
     alert(getID[0]['id']); // That's the selected ID :)
});

What is the function of the push / pop instructions used on registers in x86 assembly?

pushing a value (not necessarily stored in a register) means writing it to the stack.

popping means restoring whatever is on top of the stack into a register. Those are basic instructions:

push 0xdeadbeef      ; push a value to the stack
pop eax              ; eax is now 0xdeadbeef

; swap contents of registers
push eax
mov eax, ebx
pop ebx

unknown type name 'uint8_t', MinGW

To use uint8_t type alias, you have to include stdint.h standard header.

Pandas read_sql with parameters

The read_sql docs say this params argument can be a list, tuple or dict (see docs).

To pass the values in the sql query, there are different syntaxes possible: ?, :1, :name, %s, %(name)s (see PEP249).
But not all of these possibilities are supported by all database drivers, which syntax is supported depends on the driver you are using (psycopg2 in your case I suppose).

In your second case, when using a dict, you are using 'named arguments', and according to the psycopg2 documentation, they support the %(name)s style (and so not the :name I suppose), see http://initd.org/psycopg/docs/usage.html#query-parameters.
So using that style should work:

df = psql.read_sql(('select "Timestamp","Value" from "MyTable" '
                     'where "Timestamp" BETWEEN %(dstart)s AND %(dfinish)s'),
                   db,params={"dstart":datetime(2014,6,24,16,0),"dfinish":datetime(2014,6,24,17,0)},
                   index_col=['Timestamp'])

How to filter by string in JSONPath?

Drop the quotes:

List<Object> bugs = JsonPath.read(githubIssues, "$..labels[?(@.name==bug)]");

See also this Json Path Example page

How to store Configuration file and read it using React

With webpack you can put env-specific config into the externals field in webpack.config.js

externals: {
  'Config': JSON.stringify(process.env.NODE_ENV === 'production' ? {
    serverUrl: "https://myserver.com"
  } : {
    serverUrl: "http://localhost:8090"
  })
}

If you want to store the configs in a separate JSON file, that's possible too, you can require that file and assign to Config:

externals: {
  'Config': JSON.stringify(process.env.NODE_ENV === 'production' ? require('./config.prod.json') : require('./config.dev.json'))
}

Then in your modules, you can use the config:

var Config = require('Config')
fetchData(Config.serverUrl + '/Enterprises/...')

For React:

import Config from 'Config';
axios.get(this.app_url, {
        'headers': Config.headers
        }).then(...);

Not sure if it covers your use case but it's been working pretty well for us.

How do I split a string into an array of characters?

It's as simple as:

s.split("");

The delimiter is an empty string, hence it will break up between each single character.

How to bind to a PasswordBox in MVVM

To me, both of these things feel wrong:

  • Implementing clear text password properties
  • Sending the PasswordBox as a command parameter to the ViewModel

Transferring the SecurePassword (SecureString instance) as described by Steve in CO seems acceptable. I prefer Behaviors to code behind, and I also had the additional requirement of being able to reset the password from the viewmodel.

Xaml (Password is the ViewModel property):

<PasswordBox>
    <i:Interaction.Behaviors>
        <behaviors:PasswordBinding BoundPassword="{Binding Password, Mode=TwoWay}" />
    </i:Interaction.Behaviors>
</PasswordBox>

Behavior:

using System.Security;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Interactivity;

namespace Evidence.OutlookIntegration.AddinLogic.Behaviors
{
    /// <summary>
    /// Intermediate class that handles password box binding (which is not possible directly).
    /// </summary>
    public class PasswordBoxBindingBehavior : Behavior<PasswordBox>
    {
        // BoundPassword
        public SecureString BoundPassword { get { return (SecureString)GetValue(BoundPasswordProperty); } set { SetValue(BoundPasswordProperty, value); } }
        public static readonly DependencyProperty BoundPasswordProperty = DependencyProperty.Register("BoundPassword", typeof(SecureString), typeof(PasswordBoxBindingBehavior), new FrameworkPropertyMetadata(OnBoundPasswordChanged));

        protected override void OnAttached()
        {
            this.AssociatedObject.PasswordChanged += AssociatedObjectOnPasswordChanged;
            base.OnAttached();
        }

        /// <summary>
        /// Link up the intermediate SecureString (BoundPassword) to the UI instance
        /// </summary>
        private void AssociatedObjectOnPasswordChanged(object s, RoutedEventArgs e)
        {
            this.BoundPassword = this.AssociatedObject.SecurePassword;
        }

        /// <summary>
        /// Reacts to password reset on viewmodel (ViewModel.Password = new SecureString())
        /// </summary>
        private static void OnBoundPasswordChanged(object s, DependencyPropertyChangedEventArgs e)
        {
            var box = ((PasswordBoxBindingBehavior)s).AssociatedObject;
            if (box != null)
            {
                if (((SecureString)e.NewValue).Length == 0)
                    box.Password = string.Empty;
            }
        }

    }
}

Initialize static variables in C++ class?

Since C++11 it can be done inside a class with constexpr.

class stat {
    public:
        // init inside class
        static constexpr double inlineStaticVar = 22;
};

The variable can now be accessed with:

stat::inlineStaticVar

How to establish ssh key pair when "Host key verification failed"

Its means your remote host key was changed (May be host password change),

Your terminal suggested to execute this command as root user

$ ssh-keygen -f "/root/.ssh/known_hosts" -R [www.website.net]:4231

You have to remove that host name from hosts list on your pc/server. Copy that suggested command and execute as a root user.

$ sudo su                                                            // Login as a root user

$ ssh-keygen -f "/root/.ssh/known_hosts" -R [www.website.net]:4231   // Terminal suggested command execute here
Host [www.website.net]:4231 found: line 16 type ECDSA
/root/.ssh/known_hosts updated.
Original contents retained as /root/.ssh/known_hosts.old

$ exit                                                               // Exist from root user

$ sudo ssh [email protected] -p 4231                              // Try again

I Hope this works.

Username and password in command for git push

Git will not store the password when you use URLs like that. Instead, it will just store the username, so it only needs to prompt you for the password the next time. As explained in the manual, to store the password, you should use an external credential helper. For Windows, you can use the Windows Credential Store for Git. This helper is also included by default in GitHub for Windows.

When using it, your password will automatically be remembered, so you only need to enter it once. So when you clone, you will be asked for your password, and then every further communication with the remote will not prompt you for your password again. Instead, the credential helper will provide Git with the authentication.

This of course only works for authentication via https; for ssh access ([email protected]/repository.git) you use SSH keys and those you can remember using ssh-agent (or PuTTY’s pageant if you’re using plink).

Decimal number regular expression, where digit after decimal is optional

^\d+(()|(\.\d+)?)$

Came up with this. Allows both integer and decimal, but forces a complete decimal (leading and trailing numbers) if you decide to enter a decimal.

How can I add a custom HTTP header to ajax request with js or jQuery?

You can also do this without using jQuery. Override XMLHttpRequest's send method and add the header there:

XMLHttpRequest.prototype.realSend = XMLHttpRequest.prototype.send;
var newSend = function(vData) {
    this.setRequestHeader('x-my-custom-header', 'some value');
    this.realSend(vData);
};
XMLHttpRequest.prototype.send = newSend;

PHP cURL GET request and request's body

For those coming to this with similar problems, this request library allows you to make external http requests seemlessly within your php application. Simplified GET, POST, PATCH, DELETE and PUT requests.

A sample request would be as below

use Libraries\Request;

$data = [
  'samplekey' => 'value',
  'otherkey' => 'othervalue'
];

$headers = [
  'Content-Type' => 'application/json',
  'Content-Length' => sizeof($data)
];

$response = Request::post('https://example.com', $data, $headers);
// the $response variable contains response from the request

Documentation for the same can be found in the project's README.md

The order of keys in dictionaries

Python 3.7+

In Python 3.7.0 the insertion-order preservation nature of dict objects has been declared to be an official part of the Python language spec. Therefore, you can depend on it.

Python 3.6 (CPython)

As of Python 3.6, for the CPython implementation of Python, dictionaries maintain insertion order by default. This is considered an implementation detail though; you should still use collections.OrderedDict if you want insertion ordering that's guaranteed across other implementations of Python.

Python >=2.7 and <3.6

Use the collections.OrderedDict class when you need a dict that remembers the order of items inserted.

Turn off warnings and errors on PHP and MySQL

If you can't get to your php.ini file for some reason, disable errors to stdout (display_errors) in a .htaccess file in any directory by adding the following line:

php_flag display_errors off

additionally, you can add error logging to a file:

php_flag log_errors on

Forcing a postback

A postback is triggered after a form submission, so it's related to a client action... take a look here for an explanation: ASP.NET - Is it possible to trigger a postback from server code?

and here for a solution: http://forums.asp.net/t/928411.aspx/1

How to automatically reload a page after a given period of inactivity

Based on the accepted answer of arturnt. This is a slightly optimized version, but does essentially the same thing:

var time = new Date().getTime();
$(document.body).bind("mousemove keypress", function () {
    time = new Date().getTime();
});

setInterval(function() {
    if (new Date().getTime() - time >= 60000) {
        window.location.reload(true);
    }
}, 1000);

Only difference is that this version uses setInterval instead of setTimeout, which makes the code more compact.

How to get multiline input from user

Use the input() built-in function to get a input line from the user.

You can read the help here.

You can use the following code to get several line at once (finishing by an empty one):

while input() != '':
    do_thing