Programs & Examples On #Magnification

Animate the transition between fragments

Here's a slide in/out animation between fragments:

FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.setCustomAnimations(R.animator.enter_anim, R.animator.exit_anim);
transaction.replace(R.id.listFragment, new YourFragment());
transaction.commit();

We are using an objectAnimator.

Here are the two xml files in the animator subfolder.

enter_anim.xml

<?xml version="1.0" encoding="utf-8"?>
<set>
     <objectAnimator
         xmlns:android="http://schemas.android.com/apk/res/android"
         android:duration="1000"
         android:propertyName="x"
         android:valueFrom="2000"
         android:valueTo="0"
         android:valueType="floatType" />
</set>

exit_anim.xml

<?xml version="1.0" encoding="utf-8"?>
<set>
    <objectAnimator
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:duration="1000"
        android:propertyName="x"
        android:valueFrom="0"
        android:valueTo="-2000"
        android:valueType="floatType" />
</set>

I hope that would help someone.

How do I run two commands in one line in Windows CMD?

I try to have two pings in the same window, and it is a serial command on the same line. After finishing the first, run the second command.

The solution was to combine with start /b on a Windows 7 command prompt.

Start as usual, without /b, and launch in a separate window.

The command used to launch in the same line is:

start /b command1 parameters & command2 parameters

Any way, if you wish to parse the output, I don't recommend to use this. I noticed the output is scrambled between the output of the commands.

When should I use a struct rather than a class in C#?

.NET supports value types and reference types (in Java, you can define only reference types). Instances of reference types get allocated in the managed heap and are garbage collected when there are no outstanding references to them. Instances of value types, on the other hand, are allocated in the stack, and hence allocated memory is reclaimed as soon as their scope ends. And of course, value types get passed by value, and reference types by reference. All C# primitive data types, except for System.String, are value types.

When to use struct over class,

In C#, structs are value types, classes are reference types. You can create value types, in C#, using the enum keyword and the struct keyword. Using a value type instead of a reference type will result in fewer objects on the managed heap, which results in lesser load on the garbage collector (GC), less frequent GC cycles, and consequently better performance. However, value types have their downsides too. Passing around a big struct is definitely costlier than passing a reference, that's one obvious problem. The other problem is the overhead associated with boxing/unboxing. In case you're wondering what boxing/unboxing mean, follow these links for a good explanation on boxing and unboxing. Apart from performance, there are times when you simply need types to have value semantics, which would be very difficult (or ugly) to implement if reference types are all you have. You should use value types only, When you need copy semantics or need automatic initialization, normally in arrays of these types.

Multiple Indexes vs Multi-Column Indexes

The multi-column index can be used for queries referencing all the columns:

SELECT *
FROM TableName
WHERE Column1=1 AND Column2=2 AND Column3=3

This can be looked up directly using the multi-column index. On the other hand, at most one of the single-column index can be used (it would have to look up all records having Column1=1, and then check Column2 and Column3 in each of those).

How to export the Html Tables data into PDF using Jspdf

Here is an example I think that will help you

<!DOCTYPE html>
<html>
<head>
<script src="js/min.js"></script>
<script src="js/pdf.js"></script>
<script>
    $(function(){
         var doc = new jsPDF();
    var specialElementHandlers = {
        '#editor': function (element, renderer) {
            return true;
        }
    };

   $('#cmd').click(function () {

        var table = tableToJson($('#StudentInfoListTable').get(0))
        var doc = new jsPDF('p','pt', 'a4', true);
        doc.cellInitialize();
        $.each(table, function (i, row){
            console.debug(row);
            $.each(row, function (j, cell){
                doc.cell(10, 50,120, 50, cell, i);  // 2nd parameter=top margin,1st=left margin 3rd=row cell width 4th=Row height
            })
        })


        doc.save('sample-file.pdf');
    });
    function tableToJson(table) {
    var data = [];

    // first row needs to be headers
    var headers = [];
    for (var i=0; i<table.rows[0].cells.length; i++) {
        headers[i] = table.rows[0].cells[i].innerHTML.toLowerCase().replace(/ /gi,'');
    }


    // go through cells
    for (var i=0; i<table.rows.length; i++) {

        var tableRow = table.rows[i];
        var rowData = {};

        for (var j=0; j<tableRow.cells.length; j++) {

            rowData[ headers[j] ] = tableRow.cells[j].innerHTML;

        }

        data.push(rowData);
    }       

    return data;
}
});
</script>
</head>
<body>
<div id="table">
<table id="StudentInfoListTable">
                <thead>
                    <tr>    
                        <th>Name</th>
                        <th>Email</th>
                        <th>Track</th>
                        <th>S.S.C Roll</th>
                        <th>S.S.C Division</th>
                        <th>H.S.C Roll</th>
                        <th>H.S.C Division</th>
                        <th>District</th>

                    </tr>
                </thead>
                <tbody>

                        <tr>
                            <td>alimon  </td>
                            <td>Email</td>
                            <td>1</td>
                            <td>2222</td>
                            <td>as</td>
                            <td>3333</td>
                            <td>dd</td>
                            <td>33</td>
                        </tr>               
                </tbody>
            </table>
<button id="cmd">Submit</button>
</body>
</html>

Here the output

enter image description here

MS Access VBA: Sending an email through Outlook

Add a reference to the Outlook object model in the Visual Basic editor. Then you can use the code below to send an email using outlook.

Sub sendOutlookEmail()
Dim oApp As Outlook.Application
Dim oMail As MailItem
Set oApp = CreateObject("Outlook.application")

Set oMail = oApp.CreateItem(olMailItem)
oMail.Body = "Body of the email"
oMail.Subject = "Test Subject"
oMail.To = "[email protected]"
oMail.Send
Set oMail = Nothing
Set oApp = Nothing


End Sub

What is the purpose of class methods?

When a user logs in on my website, a User() object is instantiated from the username and password.

If I need a user object without the user being there to log in (e.g. an admin user might want to delete another users account, so i need to instantiate that user and call its delete method):

I have class methods to grab the user object.

class User():
    #lots of code
    #...
    # more code

    @classmethod
    def get_by_username(cls, username):
        return cls.query(cls.username == username).get()

    @classmethod
    def get_by_auth_id(cls, auth_id):
        return cls.query(cls.auth_id == auth_id).get()

how to change class name of an element by jquery

$('.IsBestAnswer').removeClass('IsBestAnswer').addClass('bestanswer');

Your code has two problems:

  1. The selector .IsBestAnswe does not match what you thought
  2. It's addClass(), not addclass().

Also, I'm not sure whether you want to replace the class or add it. The above will replace, but remove the .removeClass('IsBestAnswer') part to add only:

$('.IsBestAnswer').addClass('bestanswer');

You should decide whether to use camelCase or all-lowercase in your CSS classes too (e.g. bestAnswer vs. bestanswer).

Android DialogFragment vs Dialog

I would recommend using DialogFragment.

Sure, creating a "Yes/No" dialog with it is pretty complex considering that it should be rather simple task, but creating a similar dialog box with Dialog is surprisingly complicated as well.

(Activity lifecycle makes it complicated - you must let Activity manage the lifecycle of the dialog box - and there is no way to pass custom parameters e.g. the custom message to Activity.showDialog if using API levels under 8)

The nice thing is that you can usually build your own abstraction on top of DialogFragment pretty easily.

How to disable text selection highlighting

Add a class to your CSS that defines you cannot select or highlight an element. I have an example:

<style> 
    .no_highlighting{
        user-select: none;
    }

    .anchor_without_decoration:hover{
        text-decoration-style: none;
    }
</style>

<a href="#" class="anchor_without_decoration no_highlighting">Anchor text</a>

run program in Python shell

For newer version of python:

exec(open(filename).read())

How to solve Object reference not set to an instance of an object.?

You need to initialize the list first:

protected List<string> list = new List<string>();

How to code a very simple login system with java

One way you could do it is have a file with the username and pass directly under it. Then uses the Scanner class and when you create it, make the file the parameter for the Scanner. Then use the methods hasNext(); and nextLine to verify the username and password;

String user;
String pass;

Scanner scan = new Scanner(new File("File.txt"));

while(scan.hasNext){ //While the file still has more lines remaining
     if(scan.nextLine() == user){
          if(scan.nextLine == pass){
                   lblDisplay.setText("Credentials Accepted.");
          }
          else{
               lblDisplay.setText("Please try again.");
          }
     }
}

Java Runtime.getRuntime(): getting output from executing a command line program

If you write on Kotlin, you can use:

val firstProcess = ProcessBuilder("echo","hello world").start()
val firstError = firstProcess.errorStream.readBytes().decodeToString()
val firstResult = firstProcess.inputStream.readBytes().decodeToString()

DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss") is returning AM time instead of PM time?

Use HH for 24 hour hours format:

DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")

Or the tt format specifier for the AM/PM part:

DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss tt")

Take a look at the custom Date and Time format strings documentation.

Call a Javascript function every 5 seconds continuously

For repeating an action in the future, there is the built in setInterval function that you can use instead of setTimeout.
It has a similar signature, so the transition from one to another is simple:

setInterval(function() {
    // do stuff
}, duration);

Use dynamic variable names in JavaScript

This will do exactly what you done in php:

var a = 1;
var b = 2;
var ccc = 3;
var name = 'a';
console.log( window[name] ); // 1

C++ deprecated conversion from string constant to 'char*'

Maybe you can try this:

void foo(const char* str) 
{
    // Do something
}

foo("Hello")

It works for me

How to create a vector of user defined size but with no predefined values?

With the constructor:

// create a vector with 20 integer elements
std::vector<int> arr(20);

for(int x = 0; x < 20; ++x)
   arr[x] = x;

Generate C# class from XML

If you are working on .NET 4.5 project in VS 2012 (or newer), you can just Special Paste your XML file as classes.

  1. Copy your XML file's content to clipboard
  2. In editor, select place where you want your classes to be pasted
  3. From the menu, select EDIT > Paste Special > Paste XML As Classes

Html attributes for EditorFor() in ASP.NET MVC

You can still use EditorFor. Just pass the style/whichever html attribute as ViewData.

@Html.EditorFor(model => model.YourProperty, new { style = "Width:50px" })

Because EditorFor uses templates to render, you could override the default template for your property and simply pass the style attribute as ViewData.

So your EditorTemplate would like the following:

@inherits System.Web.Mvc.WebViewPage<object>

@Html.TextBoxFor(m => m, new { @class = "text ui-widget-content", style=ViewData["style"] })

How can I expand and collapse a <div> using javascript?

So, first of all, your Javascript isn't even using jQuery. There are a couple ways to do this. For example:

First way, using the jQuery toggle method:

<div class="expandContent">
        <a href="#">Click Here to Display More Content</a>
 </div>
<div class="showMe" style="display:none">
        This content was hidden, but now shows up
</div>

<script>  
    $('.expandContent').click(function(){
        $('.showMe').toggle();
    });
</script>

jsFiddle: http://jsfiddle.net/pM3DF/

Another way is simply to use the jQuery show method:

<div class="expandContent">
        <a href="#">Click Here to Display More Content</a>
 </div>
<div class="showMe" style="display:none">
        This content was hidden, but now shows up
</div>

<script>
    $('.expandContent').click(function(){
        $('.showMe').show();
    });
</script>

jsFiddle: http://jsfiddle.net/Q2wfM/

Yet a third way is to use the slideToggle method of jQuery which allows for some effects. Such as $('#showMe').slideToggle('slow'); which will slowly display the hidden div.

What's the best way to center your HTML email content in the browser window (or email client preview pane)?

Here's your bulletproof solution:

<table width="100%" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td width="33%" align="center" valign="top" style="font-family:Arial, Helvetica, sans-serif; font-size:2px; color:#ffffff;">.</td>
    <td width="35%" align="center" valign="top">
      CONTENT GOES HERE
    </td>
    <td width="33%" align="center" valign="top" style="font-family:Arial, Helvetica, sans-serif; font-size:2px; color:#ffffff;">.</td>
  </tr>
</table>

Just Try it out, Looks a bit messy, but It works Even with the new Firefox Update for Yahoo mail. (doesn't center the email because replace the main table by a div)

querySelectorAll with multiple conditions

With pure JavaScript you can do this (such as SQL) and anything you need, basically:

_x000D_
_x000D_
<html>_x000D_
_x000D_
<body>_x000D_
_x000D_
<input type='button' value='F3' class="c2" id="btn_1">_x000D_
<input type='button' value='F3' class="c3" id="btn_2">_x000D_
<input type='button' value='F1' class="c2" id="btn_3">_x000D_
_x000D_
<input type='submit' value='F2' class="c1" id="btn_4">_x000D_
<input type='submit' value='F1' class="c3" id="btn_5">_x000D_
<input type='submit' value='F2' class="c1" id="btn_6">_x000D_
_x000D_
<br/>_x000D_
<br/>_x000D_
_x000D_
<button onclick="myFunction()">Try it</button>_x000D_
_x000D_
<script>_x000D_
    function myFunction() _x000D_
    {_x000D_
        var arrFiltered = document.querySelectorAll('input[value=F2][type=submit][class=c1]');_x000D_
_x000D_
            arrFiltered.forEach(function (el)_x000D_
            {                _x000D_
                var node = document.createElement("p");_x000D_
                _x000D_
                node.innerHTML = el.getAttribute('id');_x000D_
_x000D_
                window.document.body.appendChild(node);_x000D_
            });_x000D_
        }_x000D_
    </script>_x000D_
_x000D_
</body>_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_

Change the selected value of a drop-down list with jQuery

So I changed it so that now it executes after a 300 miliseconds using setTimeout. Seems to be working now.

I have run into this many times when loading data from an Ajax call. I too use .NET, and it takes time to get adjusted to the clientId when using the jQuery selector. To correct the problem that you're having and to avoid having to add a setTimeout property, you can simply put "async: false" in the Ajax call, and it will give the DOM enough time to have the objects back that you are adding to the select. A small sample below:

$.ajax({
    type: "POST",
    url: document.URL + '/PageList',
    data: "{}",
    async: false,
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: function (response) {
        var pages = (typeof response.d) == 'string' ? eval('(' + response.d + ')') : response.d;

        $('#locPage' + locId).find('option').remove();

        $.each(pages, function () {
            $('#locPage' + locId).append(
                $('<option></option>').val(this.PageId).html(this.Name)
            );
        });
    }
});

C++ [Error] no matching function for call to

You are trying to call DeckOfCards::shuffle with a deckOfCards parameter:

deckOfCards cardDeck; // create DeckOfCards object
cardDeck.shuffle(cardDeck); // shuffle the cards in the deck

But the method takes a vector<Card>&:

void deckOfCards::shuffle(vector<Card>& deck)

The compiler error messages are quite clear on this. I'll paraphrase the compiler as it talks to you.

Error:

[Error] no matching function for call to 'deckOfCards::shuffle(deckOfCards&)'

Paraphrased:

Hey, pal. You're trying to call a function called shuffle which apparently takes a single parameter of type reference-to-deckOfCards, but there is no such function.

Error:

[Note] candidate is:

In file included from main.cpp

[Note] void deckOfCards::shuffle(std::vector&)

Paraphrased:

I mean, maybe you meant this other function called shuffle, but that one takes a reference-tovector<something>.

Error:

[Note] no known conversion for argument 1 from 'deckOfCards' to 'std::vector&'

Which I'd be happy to call if I knew how to convert from a deckOfCards to a vector; but I don't. So I won't.

why numpy.ndarray is object is not callable in my simple for python loop

The error TypeError: 'numpy.ndarray' object is not callable means that you tried to call a numpy array as a function.

Use

Z=XY[0]+XY[1]

Instead of

Z=XY(i,0)+XY(i,1)

How to change DatePicker dialog color for Android 5.0

I had the problem that time picker buttons have not been seen in the screen for API 24 in android. (API 21+) it is solved by

<style name="MyDatePickerDialogTheme" parent="android:Theme.Material.Light.Dialog">
            <item name="android:colorAccent">@color/colorPrimary2</item></style>

<style name="Theme" parent="BBaseTheme">
         <item name="android:datePickerDialogTheme">@style/MyDatePickerDialogTheme</item>
</style>

How to convert DATE to UNIX TIMESTAMP in shell script on MacOS

I used the following on Mac OSX.

currDate=`date +%Y%m%d`
epochDate=$(date -j -f "%Y%m%d" "${currDate}" "+%s")

Concatenate columns in Apache Spark DataFrame

In my case, I wanted a Tab delimited row.

from pyspark.sql import functions as F
df.select(F.concat_ws('|','_c1','_c2','_c3','_c4')).show()

This worked well like a hot knife over butter.

Comment shortcut Android Studio

On PC it's by default set to Ctrl + /. This will toggle commenting a selection or current line.

Paging UICollectionView by cells, not screen

modify Romulo BM answer for velocity listening

func scrollViewWillEndDragging(
    _ scrollView: UIScrollView,
    withVelocity velocity: CGPoint,
    targetContentOffset: UnsafeMutablePointer<CGPoint>
) {
    targetContentOffset.pointee = scrollView.contentOffset
    var indexes = collection.indexPathsForVisibleItems
    indexes.sort()
    var index = indexes.first!
    if velocity.x > 0 {
       index.row += 1
    } else if velocity.x == 0 {
        let cell = self.collection.cellForItem(at: index)!
        let position = self.collection.contentOffset.x - cell.frame.origin.x
        if position > cell.frame.size.width / 2 {
           index.row += 1
        }
    }

    self.collection.scrollToItem(at: index, at: .centeredHorizontally, animated: true )
}

How to cast the size_t to double or int C++

Assuming that the program cannot be redesigned to avoid the cast (ref. Keith Thomson's answer):

To cast from size_t to int you need to ensure that the size_t does not exceed the maximum value of the int. This can be done using std::numeric_limits:

int SizeTToInt(size_t data)
{
    if (data > std::numeric_limits<int>::max())
        throw std::exception("Invalid cast.");
    return std::static_cast<int>(data);
}

If you need to cast from size_t to double, and you need to ensure that you don't lose precision, I think you can use a narrow cast (ref. Stroustrup: The C++ Programming Language, Fourth Edition):

template<class Target, class Source>
Target NarrowCast(Source v)
{
    auto r = static_cast<Target>(v);
    if (static_cast<Source>(r) != v)
        throw RuntimeError("Narrow cast failed.");
    return r;
}

I tested using the narrow cast for size_t-to-double conversions by inspecting the limits of the maximum integers floating-point-representable integers (code uses googletest):

EXPECT_EQ(static_cast<size_t>(NarrowCast<double>(size_t{ IntegerRepresentableBoundary() - 2 })), size_t{ IntegerRepresentableBoundary() - 2 });
EXPECT_EQ(static_cast<size_t>(NarrowCast<double>(size_t{ IntegerRepresentableBoundary() - 1 })), size_t{ IntegerRepresentableBoundary() - 1 });
EXPECT_EQ(static_cast<size_t>(NarrowCast<double>(size_t{ IntegerRepresentableBoundary() })), size_t{ IntegerRepresentableBoundary() });
EXPECT_THROW(NarrowCast<double>(size_t{ IntegerRepresentableBoundary() + 1 }), std::exception);
EXPECT_EQ(static_cast<size_t>(NarrowCast<double>(size_t{ IntegerRepresentableBoundary() + 2 })), size_t{ IntegerRepresentableBoundary() + 2 });
EXPECT_THROW(NarrowCast<double>(size_t{ IntegerRepresentableBoundary() + 3 }), std::exception);
EXPECT_EQ(static_cast<size_t>(NarrowCast<double>(size_t{ IntegerRepresentableBoundary() + 4 })), size_t{ IntegerRepresentableBoundary() + 4 });
EXPECT_THROW(NarrowCast<double>(size_t{ IntegerRepresentableBoundary() + 5 }), std::exception);

where

constexpr size_t IntegerRepresentableBoundary()
{
    static_assert(std::numeric_limits<double>::radix == 2, "Method only valid for binary floating point format.");
    return size_t{2} << (std::numeric_limits<double>::digits - 1);
}

That is, if N is the number of digits in the mantissa, for doubles smaller than or equal to 2^N, integers can be exactly represented. For doubles between 2^N and 2^(N+1), every other integer can be exactly represented. For doubles between 2^(N+1) and 2^(N+2) every fourth integer can be exactly represented, and so on.

What is the OR operator in an IF statement

See C# Operators for C# operators including OR which is ||

Use and meaning of "in" in an if statement?

the reserved word "in" is used to look inside an object that can be iterated over.

list_obj = ['a', 'b', 'c']
tuple_obj = ('a', 1, 2.0)
dict_obj = {'a': 1, 'b': 2.0}
obj_to_find = 'c'
if obj_to_find in list_obj:
    print('Object {0} is in {1}'.format(obj_to_find, list_obj))
obj_to_find = 2.0
if obj_to_find in tuple_obj:
    print('Object {0} is in {1}'.format(obj_to_find, tuple_obj))
obj_to_find = 'b'
if obj_to_find in dict_obj:
    print('Object {0} is in {1}'.format(obj_to_find, dict_obj))

Output:

Object c is in ['a', 'b', 'c']
Object 2.0 is in ('a', 1, 2.0)
Object b is in {'a': 1, 'b': 2.0}

However

cannot_iterate_over = 5.5
obj_to_find = 5.5
if obj_to_find in cannot_iterate_over:
    print('Object {0} is in {1}'.format(obj_to_find, cannot_iterate_over))

will throw

Traceback (most recent call last):
File "/home/jgranger/workspace/sandbox/src/csv_file_creator.py", line 43, in <module>
if obj_to_find in cannot_iterate_over:
TypeError: argument of type 'float' is not iterable

In your case, raw_input("> ") returns iterable object or it will throw TypeError

Undefined symbols for architecture armv7

If you have the flag -ObjC under your Target > Build Settings > Other Linker Flags and you're getting this issue, consider removing it. If you intentionally added it because you need to load some Obj-C code from a static library that wouldn't normally be loaded otherwise, IE, an Obj-C category, then you should use -force_load <path> instead of -ObjC.

<path> should be relative to your Xcode project directory. IE, if your directory structure looks like this:

iOSProject
  + iOSAPI.framework
      + iOSAPI
  + iOSAPI.xcodeproj

Then you should have this flag set for Other Linker Flags:

-force_load iOSAPI.framework/iOSAPI

If you want to include multiple libraries like that, then you should include a separate -force_load line for each of them.

-force_load iOSAPI.framework/iOSAPI
-force_load another.framework/another

How can I switch my signed in user in Visual Studio 2013?

I have Visual Studio 2013 Express. I had to delete the registry key under:

hkey_current_user\software\Microsoft\VSCommon\12.\clientservices\tokenstorge\VWDExpress\ideuser

Append TimeStamp to a File Name

I prefer to use:

string result = "myFile_" + DateTime.Now.ToFileTime() + ".txt";

What does ToFileTime() do?

Converts the value of the current DateTime object to a Windows file time.

public long ToFileTime()

A Windows file time is a 64-bit value that represents the number of 100-nanosecond intervals that have elapsed since 12:00 midnight, January 1, 1601 A.D. (C.E.) Coordinated Universal Time (UTC). Windows uses a file time to record when an application creates, accesses, or writes to a file.

Source: MSDN documentation - DateTime.ToFileTime Method

Configuration System Failed to Initialize

Try to save the .config file as utf-8 if you have some "special" characters in there. That was the issue in my case of a console application.

PHP Sort a multidimensional array by element containing date

Use usort() and a custom comparison function:

function date_compare($a, $b)
{
    $t1 = strtotime($a['datetime']);
    $t2 = strtotime($b['datetime']);
    return $t1 - $t2;
}    
usort($array, 'date_compare');

EDIT: Your data is organized in an array of arrays. To better distinguish those, let's call the inner arrays (data) records, so that your data really is an array of records.

usort will pass two of these records to the given comparison function date_compare() at a a time. date_compare then extracts the "datetime" field of each record as a UNIX timestamp (an integer), and returns the difference, so that the result will be 0 if both dates are equal, a positive number if the first one ($a) is larger or a negative value if the second argument ($b) is larger. usort() uses this information to sort the array.

not None test in Python

Either of the latter two, since val could potentially be of a type that defines __eq__() to return true when passed None.

get user timezone

Just as Oded has answered. You need to have this sort of detection functionality in javascript.

I've struggled with this myself and realized that the offset is not enough. It does not give you any information about daylight saving for example. I ended up writing some code to map to zoneinfo database keys.

By checking several dates around a year you can more accurately determine a timezone.

Try the script here: http://jsfiddle.net/pellepim/CsNcf/

Simply change your system timezone and click run to test it. If you are running chrome you need to do each test in a new tab though (and safar needs to be restarted to pick up timezone changes).

If you want more details of the code check out: https://bitbucket.org/pellepim/jstimezonedetect/

Create Git branch with current changes

Since you haven't made any commits yet, you can save all your changes to the stash, create and switch to a new branch, then pop those changes back into your working tree:

git stash  # save local modifications to new stash
git checkout -b topic/newbranch
git stash pop  # apply stash and remove it from the stash list

Downloading an entire S3 bucket?

It's always better to use awscli for downloading / uploading files to s3. Sync will help you to resume without any hassle.

aws s3 sync s3://bucketname/ .

how to write javascript code inside php

Just echo the javascript out inside the if function

 <form name="testForm" id="testForm"  method="POST"  >
     <input type="submit" name="btn" value="submit" autofocus  onclick="return true;"/>
 </form>
 <?php
    if(isset($_POST['btn'])){
        echo "
            <script type=\"text/javascript\">
            var e = document.getElementById('testForm'); e.action='test.php'; e.submit();
            </script>
        ";
     }
  ?>

How to use matplotlib tight layout with Figure?

Just call fig.tight_layout() as you normally would. (pyplot is just a convenience wrapper. In most cases, you only use it to quickly generate figure and axes objects and then call their methods directly.)

There shouldn't be a difference between the QtAgg backend and the default backend (or if there is, it's a bug).

E.g.

import matplotlib.pyplot as plt

#-- In your case, you'd do something more like:
# from matplotlib.figure import Figure
# fig = Figure()
#-- ...but we want to use it interactive for a quick example, so 
#--    we'll do it this way
fig, axes = plt.subplots(nrows=4, ncols=4)

for i, ax in enumerate(axes.flat, start=1):
    ax.set_title('Test Axes {}'.format(i))
    ax.set_xlabel('X axis')
    ax.set_ylabel('Y axis')

plt.show()

Before Tight Layout

enter image description here

After Tight Layout

import matplotlib.pyplot as plt

fig, axes = plt.subplots(nrows=4, ncols=4)

for i, ax in enumerate(axes.flat, start=1):
    ax.set_title('Test Axes {}'.format(i))
    ax.set_xlabel('X axis')
    ax.set_ylabel('Y axis')

fig.tight_layout()

plt.show()

enter image description here

How do I convert seconds to hours, minutes and seconds?

The following set worked for me.

def sec_to_hours(seconds):
    a=str(seconds//3600)
    b=str((seconds%3600)//60)
    c=str((seconds%3600)%60)
    d=["{} hours {} mins {} seconds".format(a, b, c)]
    return d


print(sec_to_hours(10000))
# ['2 hours 46 mins 40 seconds']

print(sec_to_hours(60*60*24+105))
# ['24 hours 1 mins 45 seconds']

How do I make CMake output into a 'bin' dir?

cat CMakeLists.txt
project (hello)
set(CMAKE_BINARY_DIR "/bin")
set(EXECUTABLE_OUTPUT_PATH ${CMAKE_BINARY_DIR})
add_executable (hello hello.c)

How to Write text file Java

It's not creating a file because you never actually created the file. You made an object for it. Creating an instance doesn't create the file.

File newFile = new File("directory", "fileName.txt");

You can do this to make a file:

newFile.createNewFile();

You can do this to make a folder:

newFile.mkdir();

Disable-web-security in Chrome 48+

In a terminal put these:

cd C:\Program Files (x86)\Google\Chrome\Application

chrome.exe --disable-web-security --user-data-dir="c:/chromedev"

Variable number of arguments in C++?

In C++11 you have two new options, as the Variadic functions reference page in the Alternatives section states:

  • Variadic templates can also be used to create functions that take variable number of arguments. They are often the better choice because they do not impose restrictions on the types of the arguments, do not perform integral and floating-point promotions, and are type safe. (since C++11)
  • If all variable arguments share a common type, a std::initializer_list provides a convenient mechanism (albeit with a different syntax) for accessing variable arguments.

Below is an example showing both alternatives (see it live):

#include <iostream>
#include <string>
#include <initializer_list>

template <typename T>
void func(T t) 
{
    std::cout << t << std::endl ;
}

template<typename T, typename... Args>
void func(T t, Args... args) // recursive variadic function
{
    std::cout << t <<std::endl ;

    func(args...) ;
}

template <class T>
void func2( std::initializer_list<T> list )
{
    for( auto elem : list )
    {
        std::cout << elem << std::endl ;
    }
}

int main()
{
    std::string
        str1( "Hello" ),
        str2( "world" );

    func(1,2.5,'a',str1);

    func2( {10, 20, 30, 40 }) ;
    func2( {str1, str2 } ) ;
} 

If you are using gcc or clang we can use the PRETTY_FUNCTION magic variable to display the type signature of the function which can be helpful in understanding what is going on. For example using:

std::cout << __PRETTY_FUNCTION__ << ": " << t <<std::endl ;

would results int following for variadic functions in the example (see it live):

void func(T, Args...) [T = int, Args = <double, char, std::basic_string<char>>]: 1
void func(T, Args...) [T = double, Args = <char, std::basic_string<char>>]: 2.5
void func(T, Args...) [T = char, Args = <std::basic_string<char>>]: a
void func(T) [T = std::basic_string<char>]: Hello

In Visual Studio you can use FUNCSIG.

Update Pre C++11

Pre C++11 the alternative for std::initializer_list would be std::vector or one of the other standard containers:

#include <iostream>
#include <string>
#include <vector>

template <class T>
void func1( std::vector<T> vec )
{
    for( typename std::vector<T>::iterator iter = vec.begin();  iter != vec.end(); ++iter )
    {
        std::cout << *iter << std::endl ;
    }
}

int main()
{
    int arr1[] = {10, 20, 30, 40} ;
    std::string arr2[] = { "hello", "world" } ; 
    std::vector<int> v1( arr1, arr1+4 ) ;
    std::vector<std::string> v2( arr2, arr2+2 ) ;

    func1( v1 ) ;
    func1( v2 ) ;
}

and the alternative for variadic templates would be variadic functions although they are not type-safe and in general error prone and can be unsafe to use but the only other potential alternative would be to use default arguments, although that has limited use. The example below is a modified version of the sample code in the linked reference:

#include <iostream>
#include <string>
#include <cstdarg>

void simple_printf(const char *fmt, ...)
{
    va_list args;
    va_start(args, fmt);

    while (*fmt != '\0') {
        if (*fmt == 'd') {
            int i = va_arg(args, int);
            std::cout << i << '\n';
        } else if (*fmt == 's') {
            char * s = va_arg(args, char*);
            std::cout << s << '\n';
        }
        ++fmt;
    }

    va_end(args);
}


int main()
{
    std::string
        str1( "Hello" ),
        str2( "world" );

    simple_printf("dddd", 10, 20, 30, 40 );
    simple_printf("ss", str1.c_str(), str2.c_str() ); 

    return 0 ;
} 

Using variadic functions also comes with restrictions in the arguments you can pass which is detailed in the draft C++ standard in section 5.2.2 Function call paragraph 7:

When there is no parameter for a given argument, the argument is passed in such a way that the receiving function can obtain the value of the argument by invoking va_arg (18.7). The lvalue-to-rvalue (4.1), array-to-pointer (4.2), and function-to-pointer (4.3) standard conversions are performed on the argument expression. After these conversions, if the argument does not have arithmetic, enumeration, pointer, pointer to member, or class type, the program is ill-formed. If the argument has a non-POD class type (clause 9), the behavior is undefined. [...]

Printing Mongo query output to a file while in the mongo shell

If you invoke the shell with script-file, db address, and --quiet arguments, you can redirect the output (made with print() for example) to a file:

mongo localhost/mydatabase --quiet myScriptFile.js > output 

Pass a reference to DOM object with ng-click

While you do the following, technically speaking:

<button ng-click="doSomething($event)"></button>
// In controller:
$scope.doSomething = function($event) {
  //reference to the button that triggered the function:
  $event.target
};

This is probably something you don't want to do as AngularJS philosophy is to focus on model manipulation and let AngularJS do the rendering (based on hints from the declarative UI). Manipulating DOM elements and attributes from a controller is a big no-no in AngularJS world.

You might check this answer for more info: https://stackoverflow.com/a/12431211/1418796

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

Character varying is different than text. Try running

ALTER TABLE product_product ALTER COLUMN code TYPE text;

That will change the column type to text, which is limited to some very large amount of data (you would probably never actually hit it.)

Python 3 Building an array of bytes

frame = b'\xa2\x01\x02\x03\x04'

wasn't mentionned till now...

Kill python interpeter in linux from the terminal

There's a rather crude way of doing this, but be careful because first, this relies on python interpreter process identifying themselves as python, and second, it has the concomitant effect of also killing any other processes identified by that name.

In short, you can kill all python interpreters by typing this into your shell (make sure you read the caveats above!):

ps aux | grep python | grep -v "grep python" | awk '{print $2}' | xargs kill -9

To break this down, this is how it works. The first bit, ps aux | grep python | grep -v "grep python", gets the list of all processes calling themselves python, with the grep -v making sure that the grep command you just ran isn't also included in the output. Next, we use awk to get the second column of the output, which has the process ID's. Finally, these processes are all (rather unceremoniously) killed by supplying each of them with kill -9.

Difference between "@id/" and "@+id/" in Android

In Short

android:id="@+id/my_button"

+id Plus sign tells android to add or create a new id in Resources.

while

android:layout_below="@id/my_button"

it just help to refer the already generated id..

Parsing a CSV file using NodeJS

My current solution uses the async module to execute in series:

var fs = require('fs');
var parse = require('csv-parse');
var async = require('async');

var inputFile='myfile.csv';

var parser = parse({delimiter: ','}, function (err, data) {
  async.eachSeries(data, function (line, callback) {
    // do something with the line
    doSomething(line).then(function() {
      // when processing finishes invoke the callback to move to the next one
      callback();
    });
  })
});
fs.createReadStream(inputFile).pipe(parser);

How to implement a ConfigurationSection with a ConfigurationElementCollection

An easier alternative for those who would prefer not to write all that configuration boilerplate manually...

1) Install Nerdle.AutoConfig from NuGet

2) Define your ServiceConfig type (either a concrete class or just an interface, either will do)

public interface IServiceConfiguration
{
    int Port { get; }
    ReportType ReportType { get; }
}

3) You'll need a type to hold the collection, e.g.

public interface IServiceCollectionConfiguration
{
    IEnumerable<IServiceConfiguration> Services { get; } 
}

4) Add the config section like so (note camelCase naming)

<configSections>
  <section name="serviceCollection" type="Nerdle.AutoConfig.Section, Nerdle.AutoConfig"/>
</configSections>

<serviceCollection>
  <services>
    <service port="6996" reportType="File" />
    <service port="7001" reportType="Other" />
  </services>
</serviceCollection>

5) Map with AutoConfig

var services = AutoConfig.Map<IServiceCollectionConfiguration>();

Convert int to a bit array in .NET

    public static bool[] Convert(int[] input, int length)
    {
        var ret = new bool[length];
        var siz = sizeof(int) * 8;
        var pow = 0;
        var cur = 0;

        for (var a = 0; a < input.Length && cur < length; ++a)
        {
            var inp = input[a];

            pow = 1;

            if (inp > 0)
            {
                for (var i = 0; i < siz && cur < length; ++i)
                {
                    ret[cur++] = (inp & pow) == pow;

                    pow *= 2;
                }
            }
            else
            {
                for (var i = 0; i < siz && cur < length; ++i)
                {
                    ret[cur++] = (inp & pow) != pow;

                    pow *= 2;
                }
            }
        }

        return ret;
    }

C# - Create SQL Server table programmatically

using System;
using System.Data;
using System.Data.SqlClient;

namespace SqlCommend
{
    class sqlcreateapp
    {
        static void Main(string[] args)
        {
            try
            {
                SqlConnection conn = new SqlConnection("Data source=USER-PC; Database=Emp123;User Id=sa;Password=sa123");
                SqlCommand cmd = new SqlCommand("create table <Table Name>(empno int,empname varchar(50),salary money);", conn);
                conn.Open();
                cmd.ExecuteNonQuery();
                Console.WriteLine("Table Created Successfully...");
                conn.Close();
            }
            catch(Exception e)
            {
                Console.WriteLine("exception occured while creating table:" + e.Message + "\t" + e.GetType());
            }
            Console.ReadKey();
        }
    }
}

How does DateTime.Now.Ticks exactly work?

The resolution of DateTime.Now depends on your system timer (~10ms on a current Windows OS)...so it's giving the same ending value there (it doesn't count any more finite than that).

Align a div to center

This has always worked for me.

Provided you set a fixed width for your DIV, and the proper DOCTYPE, try this

div {        
  margin-left:auto;
  margin-right:auto;
}

Hope this helps.

base 64 encode and decode a string in angular (2+)

Use btoa("yourstring")

more info: https://developer.mozilla.org/en/docs/Web/API/WindowBase64/Base64_encoding_and_decoding

TypeScript is a superset of Javascript, it can use existing Javascript libraries and web APIs

How to declare and initialize a static const array as a class member?

// in foo.h
class Foo {
    static const unsigned char* Msg;
};

// in foo.cpp
static const unsigned char Foo_Msg_data[] = {0x00,0x01};
const unsigned char* Foo::Msg = Foo_Msg_data;

The role of #ifdef and #ifndef

"#if one" means that if "#define one" has been written "#if one" is executed otherwise "#ifndef one" is executed.

This is just the C Pre-Processor (CPP) Directive equivalent of the if, then, else branch statements in the C language.

i.e. if {#define one} then printf("one evaluates to a truth "); else printf("one is not defined "); so if there was no #define one statement then the else branch of the statement would be executed.

How to check that an element is in a std::set?

I was able to write a general contains function for std::list and std::vector,

template<typename T>
bool contains( const list<T>& container, const T& elt )
{
  return find( container.begin(), container.end(), elt ) != container.end() ;
}

template<typename T>
bool contains( const vector<T>& container, const T& elt )
{
  return find( container.begin(), container.end(), elt ) != container.end() ;
}

// use:
if( contains( yourList, itemInList ) ) // then do something

This cleans up the syntax a bit.

But I could not use template template parameter magic to make this work arbitrary stl containers.

// NOT WORKING:
template<template<class> class STLContainer, class T>
bool contains( STLContainer<T> container, T elt )
{
  return find( container.begin(), container.end(), elt ) != container.end() ;
}

Any comments about improving the last answer would be nice.

Recommended method for escaping HTML in Java

StringEscapeUtils from Apache Commons Lang:

import static org.apache.commons.lang.StringEscapeUtils.escapeHtml;
// ...
String source = "The less than sign (<) and ampersand (&) must be escaped before using them in HTML";
String escaped = escapeHtml(source);

For version 3:

import static org.apache.commons.lang3.StringEscapeUtils.escapeHtml4;
// ...
String escaped = escapeHtml4(source);

What is the difference between a schema and a table and a database?

schema : database : table :: floor plan : house : room

List all devices, partitions and volumes in Powershell

To get all of the file system drives, you can use the following command:

gdr -PSProvider 'FileSystem'

gdr is an alias for Get-PSDrive, which includes all of the "virtual drives" for the registry, etc.

Mac SQLite editor

You may like SQLPro for SQLite (previously SQLite Professional - App Store).

The app has a few neat features such as:

  • Auto-completion and syntax highlighting.
  • Versions Integration (rollback to previous versions).
  • Inline data filtering.
  • The ability to load sqlite extensions.
  • SQLite 2 Compatibility.
  • Exporting options to CSV, JSON, XML and MySQL.
  • Importing from CSV, JSON or XML.
  • Column reordering.
  • Full screen support.

SQLPro for SQLite overview screenshot

There is a seven day trial available via the website. If you purchase via our website, use the promo code STACK25 to save 25%.

Disclaimer: I'm the developer.

PHP Function Comments

You can get the comments of a particular method by using the ReflectionMethod class and calling ->getDocComment().

http://www.php.net/manual/en/reflectionclass.getdoccomment.php

Powershell import-module doesn't find modules

Some plugins require one to run as an Administrator and will not load unless one has those credentials active in the shell.

Split string on the first white space occurrence

I'm not sure why all other answers are so complicated, when you can do it all in one line, handling the lack of space as well.

As an example, let's get the first and "rest" components of a name:

_x000D_
_x000D_
const [first, rest] = 'John Von Doe'.split(/\s+(.*)/);
console.log({ first, rest });

// As array
const components = 'Surma'.split(/\s+(.*)/);
console.log(components);
_x000D_
_x000D_
_x000D_

Asynchronous shell exec in PHP

the right way(!) to do it is to

  1. fork()
  2. setsid()
  3. execve()

fork forks, setsid tell the current process to become a master one (no parent), execve tell the calling process to be replaced by the called one. so that the parent can quit without affecting the child.

 $pid=pcntl_fork();
 if($pid==0)
 {
   posix_setsid();
   pcntl_exec($cmd,$args,$_ENV);
   // child becomes the standalone detached process
 }

 // parent's stuff
 exit();

How to use border with Bootstrap

There's a property in CSS called box-sizing. It determines the total width of an element on your page. The default value is content-box, which doesn't include the padding, margin, or border of the element.

Hence, if you set a div to have width: 500px and 20px padding all around, it will take up 540px on your website (500 + 20 + 20).

This is what is causing your problem. Bootstrap calculates set widths for things just like the above example, and these things don't have borders. Since Bootstrap fits together like a puzzle, adding a border to one of the sides would yield a total width of 501px (continuing the above example) and break your layout.

The easiest way to fix this is to adjust your box-sizing. The value you would use is box-sizing: border-box. This includes the padding and border in your box elements. You can read more about box-sizing here.

A problem with this solution is that it only works on IE8+. Consequently, if you need deeper IE support you'll need to override the Bootstrap widths to account for your border.

To give an example of how to calculate a new width, begin by checking the width that Bootstrap sets on your element. Let's say it's a span6 and has a width of 320px (this is purely hypothetical, the actual width of your span6 will depend on your specific configuration of Bootstrap). If you wanted to add a single border on the right hand side with a 20px padding over there, you'd write this CSS in your stylesheet

.span6 {
  padding-right: 20px;
  border-right: 1px solid #ddd;
  width: 299px;
 }

where the new width is calculated by:

old width - padding - border

Multiple try codes in one block

You could try a for loop


for func,args,kwargs in zip([a,b,c,d], 
                            [args_a,args_b,args_c,args_d],
                            [kw_a,kw_b,kw_c,kw_d]):
    try:
       func(*args, **kwargs)
       break
    except:
       pass

This way you can loop as many functions as you want without making the code look ugly

Git merge develop into feature branch outputs "Already up-to-date" while it's not

You should first pull the changes from the develop branch and only then merge them to your branch:

git checkout develop 
git pull 
git checkout branch-x
git rebase develop

Or, when on branch-x:

git fetch && git rebase origin/develop

I have an alias that saves me a lot of time. Add to your ~/.gitconfig:

[alias]
    fr = "!f() { git fetch && git rebase origin/"$1"; }; f"

Now, all that you have to do is:

git fr develop

Using :: in C++

You're pretty much right about cout and cin. They are objects (not functions) defined inside the std namespace. Here are their declarations as defined by the C++ standard:

Header <iostream> synopsis

#include <ios>
#include <streambuf>
#include <istream>
#include <ostream>

namespace std {
  extern istream cin;
  extern ostream cout;
  extern ostream cerr;
  extern ostream clog;

  extern wistream wcin;
  extern wostream wcout;
  extern wostream wcerr;
  extern wostream wclog;
}

:: is known as the scope resolution operator. The names cout and cin are defined within std, so we have to qualify their names with std::.

Classes behave a little like namespaces in that the names declared inside the class belong to the class. For example:

class foo
{
  public:
    foo();
    void bar();
};

The constructor named foo is a member of the class named foo. They have the same name because its the constructor. The function bar is also a member of foo.

Because they are members of foo, when referring to them from outside the class, we have to qualify their names. After all, they belong to that class. So if you're going to define the constructor and bar outside the class, you need to do it like so:

foo::foo()
{
  // Implement the constructor
}

void foo::bar()
{
  // Implement bar
}

This is because they are being defined outside the class. If you had not put the foo:: qualification on the names, you would be defining some new functions in the global scope, rather than as members of foo. For example, this is entirely different bar:

void bar()
{
  // Implement different bar
}

It's allowed to have the same name as the function in the foo class because it's in a different scope. This bar is in the global scope, whereas the other bar belonged to the foo class.

MVVM: Tutorial from start to finish?

I have written an application using WPF, Prism and MVVM to simulate hiring a cab, you can read about it on my blog, download the source here and play with it.

Threads vs Processes in Linux

Threads -- > Threads shares a memory space,it is an abstraction of the CPU,it is lightweight. Processes --> Processes have their own memory space,it is an abstraction of a computer. To parallelise task you need to abstract a CPU. However the advantages of using a process over a thread is security,stability while a thread uses lesser memory than process and offers lesser latency. An example in terms of web would be chrome and firefox. In case of Chrome each tab is a new process hence memory usage of chrome is higher than firefox ,while the security and stability provided is better than firefox. The security here provided by chrome is better,since each tab is a new process different tab cannot snoop into the memory space of a given process.

Eclipse Bug: Unhandled event loop exception No more handles

Wow, what a variety of causes of these error messages! I'll throw one more out:

In my case, Eclipse 4.17 on Ubuntu 16.04LTS was showing these messages for multiple operations. It turns out that 16.04LTS has GTK 3.18, but Eclipse 4.17 requires GTK 3.20. Updating GTK (https://askubuntu.com/questions/933010/how-to-upgrade-gtk-3-18-to-3-20-on-ubuntu-16-04) made the error messages go away.

Get current URL from IFRAME

Hope this will help some how in your case, I suffered with the exact same problem, and just used localstorage to share the data between parent window and iframe. So in parent window you can:

localStorage.setItem("url", myUrl);

And in code where iframe source is just get this data from localstorage:

localStorage.getItem('url');

Saved me a lot of time. As far as i can see the only condition is access to the parent page code. Hope this will help someone.

Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on

Along the same lines as previous answers, but a very short addition that Allows to use all Control properties without having cross thread invokation exception.

Helper Method

/// <summary>
/// Helper method to determin if invoke required, if so will rerun method on correct thread.
/// if not do nothing.
/// </summary>
/// <param name="c">Control that might require invoking</param>
/// <param name="a">action to preform on control thread if so.</param>
/// <returns>true if invoke required</returns>
public bool ControlInvokeRequired(Control c, Action a)
{
    if (c.InvokeRequired) c.Invoke(new MethodInvoker(delegate
    {
        a();
    }));
    else return false;

    return true;
}

Sample Usage

// usage on textbox
public void UpdateTextBox1(String text)
{
    //Check if invoke requied if so return - as i will be recalled in correct thread
    if (ControlInvokeRequired(textBox1, () => UpdateTextBox1(text))) return;
    textBox1.Text = ellapsed;
}

//Or any control
public void UpdateControl(Color c, String s)
{
    //Check if invoke requied if so return - as i will be recalled in correct thread
    if (ControlInvokeRequired(myControl, () => UpdateControl(c, s))) return;
    myControl.Text = s;
    myControl.BackColor = c;
}

How to extract a single value from JSON response?

Only suggestion is to access your resp_dict via .get() for a more graceful approach that will degrade well if the data isn't as expected.

resp_dict = json.loads(resp_str)
resp_dict.get('name') # will return None if 'name' doesn't exist

You could also add some logic to test for the key if you want as well.

if 'name' in resp_dict:
    resp_dict['name']
else:
    # do something else here.

Wrap text in <td> tag

I believe you've encountered the catch 22 of tables. Tables are great for wrapping up content in a tabular structure and they do a wonderful job of "stretching" to meet the needs of the content they contain.

By default the table cells will stretch to fit content... thus your text just makes it wider.

There's a few solutions.

1.) You can try setting a max-width on the TD.

<td style="max-width:150px;">

2.) You can try putting your text in a wrapping element (e.g. a span) and set constraints on it.

<td><span style="max-width:150px;">Hello World...</span></td>

Be aware though that older versions of IE don't support min/max-width.

Since IE doesn't support max-width natively you'll need to add a hack if you want to force it to. There's several ways to add a hack, this is just one.

On page load, for IE6 only, get the rendered width of the table (in pixels) then get 15% of that and apply that as the width to the first TD in that column (or TH if you have headers) again, in pixels.

How to enable CORS in AngularJs

Apache/HTTPD tends to be around in most enterprises or if you're using Centos/etc at home. So, if you have that around, you can do a proxy very easily to add the necessary CORS headers.

I have a blog post on this here as I suffered with it quite a few times recently. But the important bit is just adding this to your /etc/httpd/conf/httpd.conf file and ensuring you are already doing "Listen 80":

<VirtualHost *:80>
    <LocationMatch "/SomePath">
       ProxyPass http://target-ip:8080/SomePath
       Header add "Access-Control-Allow-Origin" "*"
    </LocationMatch>
</VirtualHost>

This ensures that all requests to URLs under your-server-ip:80/SomePath route to http://target-ip:8080/SomePath (the API without CORS support) and that they return with the correct Access-Control-Allow-Origin header to allow them to work with your web-app.

Of course you can change the ports and target the whole server rather than SomePath if you like.

How to compile without warnings being treated as errors?

Sure, find where -Werror is set and remove that flag. Then warnings will be only warnings.

Android, Java: HTTP POST Request

to @BalusC answer I would add how to convert the response in a String:

HttpResponse response = client.execute(request);
HttpEntity entity = response.getEntity();
if (entity != null) {
    InputStream instream = entity.getContent();

    String result = RestClient.convertStreamToString(instream);
    Log.i("Read from server", result);
}

Here is an example of convertStramToString.

Length of a JavaScript object

_x000D_
_x000D_
   let myobject= {}
    let isempty =  !!Object.values(myobject);
    console.log(isempty);
_x000D_
_x000D_
_x000D_

How To: Best way to draw table in console app (C#)

It's easier in VisualBasic.net!

If you want the user to be able to manually enter data into a table:

Console.Write("Enter Data For Column 1: ")
    Dim Data1 As String = Console.ReadLine
    Console.Write("Enter Data For Column 2: ")
    Dim Data2 As String = Console.ReadLine

    Console.WriteLine("{0,-20} {1,-10} {2,-10}", "{Data Type}", "{Column 1}", "{Column 2}")
    Console.WriteLine("{0,-20} {1,-10} {2,-10}", "Data Entered:", Data1, Data2)

    Console.WriteLine("ENTER To Exit: ")
    Console.ReadLine()

It should look like this:

It should look like this (Click Me).

CSS grid wrapping

You may be looking for auto-fill:

grid-template-columns: repeat(auto-fill, 186px);

Demo: http://codepen.io/alanbuchanan/pen/wJRMox

To use up the available space more efficiently, you could use minmax, and pass in auto as the second argument:

grid-template-columns: repeat(auto-fill, minmax(186px, auto));

Demo: http://codepen.io/alanbuchanan/pen/jBXWLR

If you don't want the empty columns, you could use auto-fit instead of auto-fill.

How to make inactive content inside a div?

div[disabled]
{
  pointer-events: none;
  opacity: 0.7;
}

The above code makes the contents of the div disabled. You can make div disabled by adding disabled attribute.

<div disabled>
  /* Contents */
</div>

Changing java platform on which netbeans runs

Fix this by moving my jdk folder to other disk

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

Note that according to the CSS3 spec, you do NOT have to wrap your layout in a table-style element. The browser will infer the existence of containing elements if they do not exist.

How to make a node.js application run permanently?

Another way is creating a system unit for your app. create a "XXX.service" file in "/etc/systemd/system" folder, similar to this:

[Unit]
Description=swagger
After=network.target

[Service]
ExecStart=/usr/bin/http-server /home/swagger/swagger-editor &
WorkingDirectory=/home/swagger
Restart=always
RestartSec=30

[Install]
WantedBy=multi-user.target

A benefit is the app will run as a service, it automatically restarts if it crashed.

You can also use sytemctl to manage it:

systemctl start XXX to start the service, systemctl stop XXX to stop it and systemctl enable XXX to automatically start the app when system boots.

Git Symlinks in Windows

I just tried with Git 2.30.0 (released 2020-12-28).

This is NOT a full answer but a few useful tidbits nonetheless. (Feel free to cannibalize for your own answer.)

There's a documentation link when installing Git for Windows

enter image description here

This link takes you here: https://github.com/git-for-windows/git/wiki/Symbolic-Links

And this is quite a longish discussion.

Also symbolic links keep popping up in the release notes. As of 2.30.0 this here is still listed as a "Known issue":

On Windows 10 before 1703, or when Developer Mode is turned off, special permissions are required when cloning repositories with symbolic links, therefore support for symbolic links is disabled by default. Use git clone -c core.symlinks=true <URL> to enable it, see details here.

inserting characters at the start and end of a string

Strings are immutable so you can't insert characters into an existing string. You have to create a new string. You can use string concatenation to do what you want:

yourstring = "L" + yourstring + "LL"

Note that you can also create a string with n Ls by using multiplication:

m = 1
n = 2
yourstring = ("L" * m) + yourstring + ("L" * n)

How to pattern match using regular expression in Scala?

To expand a little on Andrew's answer: The fact that regular expressions define extractors can be used to decompose the substrings matched by the regex very nicely using Scala's pattern matching, e.g.:

val Process = """([a-cA-C])([^\s]+)""".r // define first, rest is non-space
for (p <- Process findAllIn "aha bah Cah dah") p match {
  case Process("b", _) => println("first: 'a', some rest")
  case Process(_, rest) => println("some first, rest: " + rest)
  // etc.
}

java.util.regex - importance of Pattern.compile()?

The compile() method is always called at some point; it's the only way to create a Pattern object. So the question is really, why should you call it explicitly? One reason is that you need a reference to the Matcher object so you can use its methods, like group(int) to retrieve the contents of capturing groups. The only way to get ahold of the Matcher object is through the Pattern object's matcher() method, and the only way to get ahold of the Pattern object is through the compile() method. Then there's the find() method which, unlike matches(), is not duplicated in the String or Pattern classes.

The other reason is to avoid creating the same Pattern object over and over. Every time you use one of the regex-powered methods in String (or the static matches() method in Pattern), it creates a new Pattern and a new Matcher. So this code snippet:

for (String s : myStringList) {
    if ( s.matches("\\d+") ) {
        doSomething();
    }
}

...is exactly equivalent to this:

for (String s : myStringList) {
    if ( Pattern.compile("\\d+").matcher(s).matches() ) {
        doSomething();
    }
}

Obviously, that's doing a lot of unnecessary work. In fact, it can easily take longer to compile the regex and instantiate the Pattern object, than it does to perform an actual match. So it usually makes sense to pull that step out of the loop. You can create the Matcher ahead of time as well, though they're not nearly so expensive:

Pattern p = Pattern.compile("\\d+");
Matcher m = p.matcher("");
for (String s : myStringList) {
    if ( m.reset(s).matches() ) {
        doSomething();
    }
}

If you're familiar with .NET regexes, you may be wondering if Java's compile() method is related to .NET's RegexOptions.Compiled modifier; the answer is no. Java's Pattern.compile() method is merely equivalent to .NET's Regex constructor. When you specify the Compiled option:

Regex r = new Regex(@"\d+", RegexOptions.Compiled); 

...it compiles the regex directly to CIL byte code, allowing it to perform much faster, but at a significant cost in up-front processing and memory use--think of it as steroids for regexes. Java has no equivalent; there's no difference between a Pattern that's created behind the scenes by String#matches(String) and one you create explicitly with Pattern#compile(String).

(EDIT: I originally said that all .NET Regex objects are cached, which is incorrect. Since .NET 2.0, automatic caching occurs only with static methods like Regex.Matches(), not when you call a Regex constructor directly. ref)

Why does a base64 encoded string have an = sign at the end

http://www.hcidata.info/base64.htm

Encoding "Mary had" to Base 64

In this example we are using a simple text string ("Mary had") but the principle holds no matter what the data is (e.g. graphics file). To convert each 24 bits of input data to 32 bits of output, Base 64 encoding splits the 24 bits into 4 chunks of 6 bits. The first problem we notice is that "Mary had" is not a multiple of 3 bytes - it is 8 bytes long. Because of this, the last group of bits is only 4 bits long. To remedy this we add two extra bits of '0' and remember this fact by putting a '=' at the end. If the text string to be converted to Base 64 was 7 bytes long, the last group would have had 2 bits. In this case we would have added four extra bits of '0' and remember this fact by putting '==' at the end.

How do I add 24 hours to a unix timestamp in php?

$time = date("H:i", strtotime($today . " +5 hours +30 minutes"));
//+5 hours +30 minutes     Time Zone +5:30 (Asia/Kolkata)

Python, Matplotlib, subplot: How to set the axis range?

Using axes objects is a great approach for this. It helps if you want to interact with multiple figures and sub-plots. To add and manipulate the axes objects directly:

import matplotlib.pyplot as plt
fig = plt.figure(figsize=(12,9))

signal_axes = fig.add_subplot(211)
signal_axes.plot(xs,rawsignal)

fft_axes = fig.add_subplot(212)
fft_axes.set_title("FFT")
fft_axes.set_autoscaley_on(False)
fft_axes.set_ylim([0,1000])
fft = scipy.fft(rawsignal)
fft_axes.plot(abs(fft))

plt.show()

node.js execute system command synchronously

There's an excellent module for flow control in node.js called asyncblock. If wrapping the code in a function is OK for your case, the following sample may be considered:

var asyncblock = require('asyncblock');
var exec = require('child_process').exec;

asyncblock(function (flow) {
    exec('node -v', flow.add());
    result = flow.wait();
    console.log(result);    // There'll be trailing \n in the output

    // Some other jobs
    console.log('More results like if it were sync...');
});

<hr> tag in Twitter Bootstrap not functioning correctly?

By default, the hr element in Twitter Bootstrap CSS file has a top and bottom margin of 18px. That's what creates a gap. If you want the gap to be smaller you'll need to adjust margin property of the hr element.

In your example, do something like this:

.container hr {
margin: 2px 0;
}

textarea's rows, and cols attribute in CSS

I just wanted to post a demo using calc() for setting rows/height, since no one did.

_x000D_
_x000D_
body {_x000D_
  /* page default */_x000D_
  font-size: 15px;_x000D_
  line-height: 1.5;_x000D_
}_x000D_
_x000D_
textarea {_x000D_
  /* demo related */_x000D_
  width: 300px;_x000D_
  margin-bottom: 1em;_x000D_
  display: block;_x000D_
  _x000D_
  /* rows related */_x000D_
  font-size: inherit;_x000D_
  line-height: inherit;_x000D_
  padding: 3px;_x000D_
}_x000D_
_x000D_
textarea.border-box {_x000D_
  box-sizing: border-box;_x000D_
}_x000D_
_x000D_
textarea.rows-5 {_x000D_
  /* height: calc(font-size * line-height * rows); */_x000D_
  height: calc(1em * 1.5 * 5);_x000D_
}_x000D_
_x000D_
textarea.border-box.rows-5 {_x000D_
  /* height: calc(font-size * line-height * rows + padding-top + padding-bottom + border-top-width + border-bottom-width); */_x000D_
  height: calc(1em * 1.5 * 5 + 3px + 3px + 1px + 1px);_x000D_
}
_x000D_
<p>height is 2 rows by default</p>_x000D_
_x000D_
<textarea>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</textarea>_x000D_
_x000D_
<p>height is 5 now</p>_x000D_
_x000D_
<textarea class="rows-5">Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</textarea>_x000D_
_x000D_
<p>border-box height is 5 now</p>_x000D_
_x000D_
<textarea class="border-box rows-5">Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</textarea>
_x000D_
_x000D_
_x000D_

If you use large values for the paddings (e.g. greater than 0.5em), you'll start to see the text that overflows the content(-box) area, and that might lead you to think that the height is not exactly x rows (that you set), but it is. To understand what's going on, you might want to check out The box model and box-sizing pages.

How can I hide select options with JavaScript? (Cross browser)

Three years late, but my Googling brought me here so hopefully my answer will be useful for someone else.

I just created a second option (which I hid with CSS) and used Javascript to move the s backwards and forwards between them.

<select multiple id="sel1">
  <option class="set1">Blah</option>
</select>
<select multiple id="sel2" style="display:none">
  <option class="set2">Bleh</option>
</select>

Something like that, and then something like this will move an item onto the list (i.e., make it visible). Obviously adapt the code as needed for your purpose.

$('#sel2 .set2').appendTo($('#sel1'))

notifyDataSetChange not working from custom adapter

If by any chance you landed on this thread and wondering why adapter.invaidate() or adapter.clear() methods are not present in your case then maybe because you might be using RecyclerView.Adapter instead of BaseAdapter which is used by the asker of this question. If clearing the list or arraylist not resolving your problem then it may happen that you are making two or more instances of the adapter for ex.:

MainActivity

...

adapter = new CustomAdapter(list);
adapter.notifyDataSetChanged();
recyclerView.setAdapter(adapter);

...

and
SomeFragment

...

adapter = new CustomAdapter(newList);
adapter.notifyDataSetChanged();

...

If in the second case you are expecting a change in the list of inflated views in recycler view then it is not gonna happen as in the second time a new instance of the adapter is created which is not attached to the recycler view. Setting notifyDataSetChanged in the second adapter is not gonna change the content of recycer view. For that make a new instance of the recycler view in SomeFragment and attach it to the new instance of the adapter.

SomeFragment

...

recyclerView = new RecyclerView();
adapter = new CustomAdapter();
recyclerView.setAdapter(adapter);

...

Although, I don't recommend making multiple instances of the same adapter and recycler view.

Twitter Bootstrap carousel different height images cause bouncing arrows

You can also use this code to adjust to all carousel images.

.carousel-item{
    width: 100%; /*width you want*/
    height: 500px; /*height you want*/
    overflow: hidden;
}
.carousel-item img{
    width: 100%;
    height: 100%;
    object-fit: cover;
}

VB.net: Date without time

FormatDateTime(Now, DateFormat.ShortDate)

How to apply a function to two columns of Pandas dataframe

Returning a list from apply is a dangerous operation as the resulting object is not guaranteed to be either a Series or a DataFrame. And exceptions might be raised in certain cases. Let's walk through a simple example:

df = pd.DataFrame(data=np.random.randint(0, 5, (5,3)),
                  columns=['a', 'b', 'c'])
df
   a  b  c
0  4  0  0
1  2  0  1
2  2  2  2
3  1  2  2
4  3  0  0

There are three possible outcomes with returning a list from apply

1) If the length of the returned list is not equal to the number of columns, then a Series of lists is returned.

df.apply(lambda x: list(range(2)), axis=1)  # returns a Series
0    [0, 1]
1    [0, 1]
2    [0, 1]
3    [0, 1]
4    [0, 1]
dtype: object

2) When the length of the returned list is equal to the number of columns then a DataFrame is returned and each column gets the corresponding value in the list.

df.apply(lambda x: list(range(3)), axis=1) # returns a DataFrame
   a  b  c
0  0  1  2
1  0  1  2
2  0  1  2
3  0  1  2
4  0  1  2

3) If the length of the returned list equals the number of columns for the first row but has at least one row where the list has a different number of elements than number of columns a ValueError is raised.

i = 0
def f(x):
    global i
    if i == 0:
        i += 1
        return list(range(3))
    return list(range(4))

df.apply(f, axis=1) 
ValueError: Shape of passed values is (5, 4), indices imply (5, 3)

Answering the problem without apply

Using apply with axis=1 is very slow. It is possible to get much better performance (especially on larger datasets) with basic iterative methods.

Create larger dataframe

df1 = df.sample(100000, replace=True).reset_index(drop=True)

Timings

# apply is slow with axis=1
%timeit df1.apply(lambda x: mylist[x['col_1']: x['col_2']+1], axis=1)
2.59 s ± 76.8 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)

# zip - similar to @Thomas
%timeit [mylist[v1:v2+1] for v1, v2 in zip(df1.col_1, df1.col_2)]  
29.5 ms ± 534 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)

@Thomas answer

%timeit list(map(get_sublist, df1['col_1'],df1['col_2']))
34 ms ± 459 µs per loop (mean ± std. dev. of 7 runs, 10 loops each)

$(document).on("click"... not working?

Try this:

$("#test-element").on("click" ,function() {
    alert("click");
});

The document way of doing it is weird too. That would make sense to me if used for a class selector, but in the case of an id you probably just have useless DOM traversing there. In the case of the id selector, you get that element instantly.

Python - Dimension of Data Frame

df.shape, where df is your DataFrame.

ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired

There is a very easy work around for this problem.

If you run a 10046 trace on your session (google this... too much to explain). You will see that before any DDL operation Oracle does the following:

LOCK TABLE 'TABLE_NAME' NO WAIT

So if another session has an open transaction you get an error. So the fix is... drum roll please. Issue your own lock before the DDL and leave out the 'NO WAIT'.

Special Note:

if you are doing splitting/dropping partitions oracle just locks the partition. -- so yo can just lock the partition subpartition.

So... The following steps fix the problem.

  1. LOCK TABLE 'TABLE NAME'; -- you will 'wait' (developers call this hanging). until the session with the open transaction, commits. This is a queue. so there may be several sessions ahead of you. but you will NOT error out.
  2. Execute DDL. Your DDL will then run a lock with the NO WAIT. However, your session has aquired the lock. So you are good.
  3. DDL auto-commits. This frees the locks.

DML statements will 'wait' or as developers call it 'hang' while the table is locked.

I use this in code that runs from a job to drop partitions. It works fine. It is in a database that is constantly inserting at a rate of several hundred inserts/second. No errors.

if you are wondering. Doing this in 11g. I have done this in 10g before as well in the past.

GCC fatal error: stdio.h: No such file or directory

Mac OS X

I had this problem too (encountered through Macports compilers). Previous versions of Xcode would let you install command line tools through xcode/Preferences, but xcode5 doesn't give a command line tools option in the GUI, that so I assumed it was automatically included now. Try running this command:

xcode-select --install

Ubuntu

(as per this answer)

sudo apt-get install libc6-dev

Alpine Linux

(as per this comment)

apk add libc-dev

How to check if a registry value exists using C#?

For Registry Key you can check if it is null after getting it. It will be, if it doesn't exist.

For Registry Value you can get names of Values for the current key and check if this array contains the needed Value name.

Example:

public static bool checkMachineType()
{    
    RegistryKey winLogonKey = Registry.LocalMachine.OpenSubKey(@"System\CurrentControlSet\services\pcmcia", true);
    return (winLogonKey.GetValueNames().Contains("Start"));
}

R : how to simply repeat a command?

It's not clear whether you're asking this because you are new to programming, but if that's the case then you should probably read this article on loops and indeed read some basic materials on programming.

If you already know about control structures and you want the R-specific implementation details then there are dozens of tutorials around, such as this one. The other answer uses replicate and colMeans, which is idiomatic when writing in R and probably blazing fast as well, which is important if you want 10,000 iterations.

However, one more general and (for beginners) straightforward way to approach problems of this sort would be to use a for loop.

> for (ii in 1:5) { + print(ii) + } [1] 1 [1] 2 [1] 3 [1] 4 [1] 5 > 

So in your case, if you just wanted to print the mean of your Tandem object 5 times:

for (ii in 1:5) {     Tandem <- sample(OUT, size = 815, replace = TRUE, prob = NULL)     TandemMean <- mean(Tandem)     print(TandemMean) } 

As mentioned above, replicate is a more natural way to deal with this specific problem using R. Either way, if you want to store the results - which is surely the case - you'll need to start thinking about data structures like vectors and lists. Once you store something you'll need to be able to access it to use it in future, so a little knowledge is vital.

set.seed(1234) OUT <- runif(100000, 1, 2) tandem <- list() for (ii in 1:10000) {     tandem[[ii]] <- mean(sample(OUT, size = 815, replace = TRUE, prob = NULL)) }  tandem[1] tandem[100] tandem[20:25] 

...creates this output:

> set.seed(1234) > OUT <- runif(100000, 1, 2) > tandem <- list() > for (ii in 1:10000) { +     tandem[[ii]] <- mean(sample(OUT, size = 815, replace = TRUE, prob = NULL)) + } >  > tandem[1] [[1]] [1] 1.511923  > tandem[100] [[1]] [1] 1.496777  > tandem[20:25] [[1]] [1] 1.500669  [[2]] [1] 1.487552  [[3]] [1] 1.503409  [[4]] [1] 1.501362  [[5]] [1] 1.499728  [[6]] [1] 1.492798  >  

How do I reference to another (open or closed) workbook, and pull values back, in VBA? - Excel 2007

You will have to open the file in one way or another if you want to access the data within it. Obviously, one way is to open it in your Excel application instance, e.g.:-

(untested code)

Dim wbk As Workbook
Set wbk = Workbooks.Open("C:\myworkbook.xls")

' now you can manipulate the data in the workbook anyway you want, e.g. '

Dim x As Variant
x = wbk.Worksheets("Sheet1").Range("A6").Value

Call wbk.Worksheets("Sheet2").Range("A1:G100").Copy
Call ThisWorbook.Worksheets("Target").Range("A1").PasteSpecial(xlPasteValues)
Application.CutCopyMode = False

' etc '

Call wbk.Close(False)

Another way to do it would be to use the Excel ADODB provider to open a connection to the file and then use SQL to select data from the sheet you want, but since you are anyway working from within Excel I don't believe there is any reason to do this rather than just open the workbook. Note that there are optional parameters for the Workbooks.Open() method to open the workbook as read-only, etc.

Measure execution time for a Java method

You can take timestamp snapshots before and after, then repeat the experiments several times to average to results. There are also profilers that can do this for you.


From "Java Platform Performance: Strategies and Tactics" book:

With System.currentTimeMillis()

class TimeTest1 {
   public static void main(String[] args) {

      long startTime = System.currentTimeMillis();

      long total = 0;
      for (int i = 0; i < 10000000; i++) {
         total += i;
      }

      long stopTime = System.currentTimeMillis();
      long elapsedTime = stopTime - startTime;
      System.out.println(elapsedTime);
   }
}

With a StopWatch class

You can use this StopWatch class, and call start() and stop before and after the method.

class TimeTest2 {
   public static void main(String[] args) {

      Stopwatch timer = new Stopwatch().start();

      long total = 0;
      for (int i = 0; i < 10000000; i++) {
         total += i;
      }

      timer.stop();
      System.out.println(timer.getElapsedTime());
   }
}

See here (archived).


NetBeans Profiler:

Application Performance Application

Performance profiles method-level CPU performance (execution time). You can choose to profile the entire application or a part of the application.

See here.

Use async await with Array.map

I had a task on BE side to find all entities from a repo, and to add a new property url and to return to controller layer. This is how I achieved it (thanks to Ajedi32's response):

async findAll(): Promise<ImageResponse[]> {
    const images = await this.imageRepository.find(); // This is an array of type Image (DB entity)
    const host = this.request.get('host');
    const mappedImages = await Promise.all(images.map(image => ({...image, url: `http://${host}/images/${image.id}`}))); // This is an array of type Object
    return plainToClass(ImageResponse, mappedImages); // Result is an array of type ImageResponse
  }

Note: Image (entity) doesn't have property url, but ImageResponse - has

How to set ChartJS Y axis title?

For Chart.js 2.x refer to andyhasit's answer - https://stackoverflow.com/a/36954319/360067

For Chart.js 1.x, you can tweak the options and extend the chart type to do this, like so

Chart.types.Line.extend({
    name: "LineAlt",
    draw: function () {
        Chart.types.Line.prototype.draw.apply(this, arguments);

        var ctx = this.chart.ctx;
        ctx.save();
        // text alignment and color
        ctx.textAlign = "center";
        ctx.textBaseline = "bottom";
        ctx.fillStyle = this.options.scaleFontColor;
        // position
        var x = this.scale.xScalePaddingLeft * 0.4;
        var y = this.chart.height / 2;
        // change origin
        ctx.translate(x, y);
        // rotate text
        ctx.rotate(-90 * Math.PI / 180);
        ctx.fillText(this.datasets[0].label, 0, 0);
        ctx.restore();
    }
});

calling it like this

var ctx = document.getElementById("myChart").getContext("2d");
var myLineChart = new Chart(ctx).LineAlt(data, {
    // make enough space on the right side of the graph
    scaleLabel: "          <%=value%>"
});

Notice the space preceding the label value, this gives us space to write the y axis label without messing around with too much of Chart.js internals


Fiddle - http://jsfiddle.net/wyox23ga/


enter image description here

Swift Error: Editor placeholder in source file

After Command + Shift + B, the project works fine.

How to use XPath in Python?

You can use the simple soupparser from lxml

Example:

from lxml.html.soupparser import fromstring

tree = fromstring("<a>Find me!</a>")
print tree.xpath("//a/text()")

random number generator between 0 - 1000 in c#

Use this:

static int RandomNumber(int min, int max)
{
    Random random = new Random(); return random.Next(min, max);

}

This is example for you to modify and use in your application.

Change image source with JavaScript

Try this!

function changeimage() {
    var image = document.getElementById('imagem');
    if (image.src.match("img")) {
        for(i = 1; i <= 3; i++) {
            image.src = "img/image2"+i+".png";
        }
    } else {
        image.src = "img/image1.png";
    }
}

How to check if a string in Python is in ASCII?

Your question is incorrect; the error you see is not a result of how you built python, but of a confusion between byte strings and unicode strings.

Byte strings (e.g. "foo", or 'bar', in python syntax) are sequences of octets; numbers from 0-255. Unicode strings (e.g. u"foo" or u'bar') are sequences of unicode code points; numbers from 0-1112064. But you appear to be interested in the character é, which (in your terminal) is a multi-byte sequence that represents a single character.

Instead of ord(u'é'), try this:

>>> [ord(x) for x in u'é']

That tells you which sequence of code points "é" represents. It may give you [233], or it may give you [101, 770].

Instead of chr() to reverse this, there is unichr():

>>> unichr(233)
u'\xe9'

This character may actually be represented either a single or multiple unicode "code points", which themselves represent either graphemes or characters. It's either "e with an acute accent (i.e., code point 233)", or "e" (code point 101), followed by "an acute accent on the previous character" (code point 770). So this exact same character may be presented as the Python data structure u'e\u0301' or u'\u00e9'.

Most of the time you shouldn't have to care about this, but it can become an issue if you are iterating over a unicode string, as iteration works by code point, not by decomposable character. In other words, len(u'e\u0301') == 2 and len(u'\u00e9') == 1. If this matters to you, you can convert between composed and decomposed forms by using unicodedata.normalize.

The Unicode Glossary can be a helpful guide to understanding some of these issues, by pointing how how each specific term refers to a different part of the representation of text, which is far more complicated than many programmers realize.

Should I use the datetime or timestamp data type in MySQL?

timestamp is a current time of an event recorded by a computer through Network Time Protocol (NTP).

datetime is a current timezone that is set in your PHP configuration.

Android Error Building Signed APK: keystore.jks not found for signing config 'externalOverride'

This is a problem that can arise from writing down a "filename" instead of a path, while generating the .jks file. Generate a new one, put it on the Desktop (or any other real path) and re-generate APK.

How set background drawable programmatically in Android

if (android.os.Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN)
     layout.setBackgroundDrawable(getResources().getDrawable(R.drawable.ready));
else if(android.os.Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP_MR1)
     layout.setBackground(getResources().getDrawable(R.drawable.ready));
else
     layout.setBackground(ContextCompat.getDrawable(this, R.drawable.ready));

HttpContext.Current.Request.Url.Host what it returns?

Yes, as long as the url you type into the browser www.someshopping.com and you aren't using url rewriting then

string currentURL = HttpContext.Current.Request.Url.Host;

will return www.someshopping.com

Note the difference between a local debugging environment and a production environment

Login to website, via C#

Sometimes, it may help switching off AllowAutoRedirect and setting both login POST and page GET requests the same user agent.

request.UserAgent = userAgent;
request.AllowAutoRedirect = false;

jQuery or Javascript - how to disable window scroll without overflow:hidden;

You can use jquery-disablescroll to solve the problem:

  • Disable scrolling: $window.disablescroll();
  • Enable scrolling again: $window.disablescroll("undo");

Supports handleWheel, handleScrollbar, handleKeys and scrollEventKeys.

Working with INTERVAL and CURDATE in MySQL

As suggested by A Star, I always use something along the lines of:

DATE(NOW()) - INTERVAL 1 MONTH

Similarly you can do:

NOW() + INTERVAL 5 MINUTE
"2013-01-01 00:00:00" + INTERVAL 10 DAY

and so on. Much easier than typing DATE_ADD or DATE_SUB all the time :)!

VBA Check if variable is empty

I had a similar issue with an integer that could be legitimately assigned 0 in Access VBA. None of the above solutions worked for me.

At first I just used a boolean var and IF statement:

Dim i as integer, bol as boolean
   If bol = false then
      i = ValueIWantToAssign
      bol = True
   End If

In my case, my integer variable assignment was within a for loop and another IF statement, so I ended up using "Exit For" instead as it was more concise.

Like so:

Dim i as integer
ForLoopStart
   If ConditionIsMet Then
      i = ValueIWantToAssign
   Exit For
   End If
ForLoopEnd

JOptionPane Input to int

Simply use:

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

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

Can't connect to MySQL server on '127.0.0.1' (10061) (2003)

If you have already created a localhost connection and its still showing can not connect then goto taskbar and find the MySQL notifier icon. Click on that and check whether your connection name is running or stopped. If its stopped then start or restart. I was facing the same issue but it fixed my problem.

Generate SQL Create Scripts for existing tables with Query

we can let the SQL to generate create table script by navigating as

Script Table as > CREATE To > New Query Editor Window

enter image description here

Ansible: How to delete files and folders inside a directory?

try the below command, it should work

- shell: ls -1 /some/dir
  register: contents

- file: path=/some/dir/{{ item }} state=absent
  with_items: {{ contents.stdout_lines }}

Windows Batch Files: if else

you have to do like this...

if not "A%1" == "A"

if the input argument %1 is null, your code will have problem.

Convert an image (selected by path) to base64 string

That way it's simpler, where you pass the image and then pass the format.

private static string ImageToBase64(Image image)
{
    var imageStream = new MemoryStream();
    try
    {           
        image.Save(imageStream, System.Drawing.Imaging.ImageFormat.Bmp);
        imageStream.Position = 0;
        var imageBytes = imageStream.ToArray();
        var ImageBase64 = Convert.ToBase64String(imageBytes);
        return ImageBase64;
    }
    catch (Exception ex)
    {
        return "Error converting image to base64!";
    }
    finally
    {
      imageStream.Dispose;
    }
}

Android Studio Stuck at Gradle Download on create new project

Invalidate Caches and Restart

It worked for me.

Render HTML in React Native

Edit Jan 2021: The React Native docs currently recommend React Native WebView:

<WebView
    originWhitelist={['*']}
    source={{ html: '<p>Here I am</p>' }}
/>

https://github.com/react-native-webview/react-native-webview


Edit March 2017: the html prop has been deprecated. Use source instead:

<WebView source={{html: '<p>Here I am</p>'}} />

https://facebook.github.io/react-native/docs/webview.html#html

Thanks to Justin for pointing this out.


Edit Feb 2017: the PR was accepted a while back, so to render HTML in React Native, simply:

<WebView html={'<p>Here I am</p>'} />

Original Answer:

I don't think this is currently possible. The behavior you're seeing is expected, since the Text component only outputs... well, text. You need another component that outputs HTML - and that's the WebView.

Unfortunately right now there's no way of just directly setting the HTML on this component:

https://github.com/facebook/react-native/issues/506

However I've just created this PR which implements a basic version of this feature so hopefully it'll land in some form soonish.

Git push hangs when pushing to Github?

Try GIT_CURL_VERBOSE=1 git push

...Your problem may occur due to proxy settings, for instance if git is trying to reach github.com via a proxy server and the proxy is not responding.

With GIT_CURL_VERBOSE=1 it will show the target IP address and some information. You can compare this IP address with the output of the command: host www.github.com. If these IPs are different then you can set https_proxy="" and try again.

How to use Sublime over SSH

Another mac solution similar to osxfuse is to just use Transmit FTP client from Panic Software, which allows you to mount a remote folder as a local disk. It supports SFTP, which is very secure.

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

You can turn the values of an Object into an array and test that a string is present. It assumes that the Object is not nested and the string is an exact match:

var obj = { a: 'test1', b: 'test2' };
if (Object.values(obj).indexOf('test1') > -1) {
   console.log('has test1');
}

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/values

How to do joins in LINQ on multiple fields in single join

you could do something like (below)

var query = from p in context.T1

        join q in context.T2

        on

        new { p.Col1, p.Col2 }

        equals

         new { q.Col1, q.Col2 }

        select new {p...., q......};

Using a different font with twitter bootstrap

Hi you can create a customized build on bootstrap, just change the font name in the following pages

Bootstrap 2.3.2 http://getbootstrap.com/2.3.2/customize.html#variables

Bootstrap 3 http://getbootstrap.com/customize/#less-variables

After that, make sure to use proper @font-face in a css file and link that to your page. Or you could use font kit generators.

Validating an XML against referenced XSD in C#

personally I favor validating without a callback:

public bool ValidateSchema(string xmlPath, string xsdPath)
{
    XmlDocument xml = new XmlDocument();
    xml.Load(xmlPath);

    xml.Schemas.Add(null, xsdPath);

    try
    {
        xml.Validate(null);
    }
    catch (XmlSchemaValidationException)
    {
        return false;
    }
    return true;
}

(see Timiz0r's post in Synchronous XML Schema Validation? .NET 3.5)

Unable to copy file - access to the path is denied

This has reared it's head again in Visual Studio 2017, in this case the cause is the Application Insights process ServiceHub.DataWarehouseHost.exe.

There is a workaround discussed in the thread warning MSB3026: Could not copy "obj\Debug\netcoreapp1.1\src.pdb" to "bin\Debug\netcoreapp1.1\src.pdb", which is to add a pre-build event to the project to kill the process every time the project is built. Quoting from that link:

  • Right click properties on project
  • Choose properties
  • Build Events
  • Pre-build event command line
taskkill /IM ServiceHub.DataWarehouseHost.exe /F 2>nul 1>nul
Exit 0
  • Save and build

Error: Failed to lookup view in Express

This error really just has to do with the file Path,thats all you have to check,for me my parent folder was "Layouts" but my actual file was layout.html,my path had layouts on both,once i corrected that error was gone.

What is the proper declaration of main in C++?

The two valid mains are int main() and int main(int, char*[]). Any thing else may or may not compile. If main doesn't explicitly return a value, 0 is implicitly returned.

How to change value of object which is inside an array using JavaScript or jQuery?

You can use $.each() to iterate over the array and locate the object you're interested in:

$.each(projects, function() {
    if (this.value == "jquery-ui") {
        this.desc = "Your new description";
    }
});

How to change the version of the 'default gradle wrapper' in IntelliJ IDEA?

I was facing same issue for changing default gradle version from 5.0 to 4.7, Below are the steps to change default gradle version in intellij enter image description here
1) Change gradle version in gradle/wrapper/gradle-wrapper.properties in this property distributionUrl

2) Hit refresh button in gradle projects menu so that it will start downloading new gradle zip version

jQuery if Element has an ID?

Number of .parent a elements that have an id attribute:

$('.parent a[id]').length

Flexbox: how to get divs to fill up 100% of the container width without wrapping?

In my case, just using flex-shrink: 0 didn't work. But adding flex-grow: 1 to it worked.

.item {
    flex-shrink: 0;
    flex-grow: 1;
}

How to Increase Import Size Limit in phpMyAdmin

On newer version of cpanel: search ini

Select the Home Directory

Scrool down to 'upload_max_filesize' and edit it...then save[enter enter image description here

SCP Permission denied (publickey). on EC2 only when using -r flag on directories

The -i flag specifies the private key (.pem file) to use. If you don't specify that flag (as in your first command) it will use your default ssh key (usually under ~/.ssh/).

So in your first command, you are actually asking scp to upload the .pem file itself using your default ssh key. I don't think that is what you want.

Try instead with:

scp -r -i /Applications/XAMPP/htdocs/keypairfile.pem uploads/* ec2-user@publicdns:/var/www/html/uploads

How to iterate through a list of dictionaries in Jinja template?

{% for i in yourlist %}
  {% for k,v in i.items() %}
    {# do what you want here #}
  {% endfor %}
{% endfor %}

What is this spring.jpa.open-in-view=true property in Spring Boot?

The OSIV Anti-Pattern

Instead of letting the business layer decide how it’s best to fetch all the associations that are needed by the View layer, OSIV (Open Session in View) forces the Persistence Context to stay open so that the View layer can trigger the Proxy initialization, as illustrated by the following diagram.

enter image description here

  • The OpenSessionInViewFilter calls the openSession method of the underlying SessionFactory and obtains a new Session.
  • The Session is bound to the TransactionSynchronizationManager.
  • The OpenSessionInViewFilter calls the doFilter of the javax.servlet.FilterChain object reference and the request is further processed
  • The DispatcherServlet is called, and it routes the HTTP request to the underlying PostController.
  • The PostController calls the PostService to get a list of Post entities.
  • The PostService opens a new transaction, and the HibernateTransactionManager reuses the same Session that was opened by the OpenSessionInViewFilter.
  • The PostDAO fetches the list of Post entities without initializing any lazy association.
  • The PostService commits the underlying transaction, but the Session is not closed because it was opened externally.
  • The DispatcherServlet starts rendering the UI, which, in turn, navigates the lazy associations and triggers their initialization.
  • The OpenSessionInViewFilter can close the Session, and the underlying database connection is released as well.

At first glance, this might not look like a terrible thing to do, but, once you view it from a database perspective, a series of flaws start to become more obvious.

The service layer opens and closes a database transaction, but afterward, there is no explicit transaction going on. For this reason, every additional statement issued from the UI rendering phase is executed in auto-commit mode. Auto-commit puts pressure on the database server because each transaction issues a commit at end, which can trigger a transaction log flush to disk. One optimization would be to mark the Connection as read-only which would allow the database server to avoid writing to the transaction log.

There is no separation of concerns anymore because statements are generated both by the service layer and by the UI rendering process. Writing integration tests that assert the number of statements being generated requires going through all layers (web, service, DAO) while having the application deployed on a web container. Even when using an in-memory database (e.g. HSQLDB) and a lightweight webserver (e.g. Jetty), these integration tests are going to be slower to execute than if layers were separated and the back-end integration tests used the database, while the front-end integration tests were mocking the service layer altogether.

The UI layer is limited to navigating associations which can, in turn, trigger N+1 query problems. Although Hibernate offers @BatchSize for fetching associations in batches, and FetchMode.SUBSELECT to cope with this scenario, the annotations are affecting the default fetch plan, so they get applied to every business use case. For this reason, a data access layer query is much more suitable because it can be tailored to the current use case data fetch requirements.

Last but not least, the database connection is held throughout the UI rendering phase which increases connection lease time and limits the overall transaction throughput due to congestion on the database connection pool. The more the connection is held, the more other concurrent requests are going to wait to get a connection from the pool.

Spring Boot and OSIV

Unfortunately, OSIV (Open Session in View) is enabled by default in Spring Boot, and OSIV is really a bad idea from a performance and scalability perspective.

So, make sure that in the application.properties configuration file, you have the following entry:

spring.jpa.open-in-view=false

This will disable OSIV so that you can handle the LazyInitializationException the right way.

Starting with version 2.0, Spring Boot issues a warning when OSIV is enabled by default, so you can discover this problem long before it affects a production system.

How can I delete derived data in Xcode 8?

It may differ between versions of xcodes. Best approach is to go xcode preference page and from tab "Locations", directly open "Derived Data" directory.

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

I had the same problem. I tried installing Visual Studio 2010 SP1 but it didn't worked.

Finally I get Microsoft.Web.Infrastructure.dll from the colleague. You can find the dll into your friends PC where the project is perfectly working. Try to search dll into Temp/Temporary ASP.NET Files. Go to Temp using %temp% into run window.

After getting dll into your pc, just add reference to your project and it will work.

What does '&' do in a C++ declaration?

Here, & is not used as an operator. As part of function or variable declarations, & denotes a reference. The C++ FAQ Lite has a pretty nifty chapter on references.

Best way of invoking getter by reflection

You can use Reflections framework for this

import static org.reflections.ReflectionUtils.*;
Set<Method> getters = ReflectionUtils.getAllMethods(someClass,
      withModifier(Modifier.PUBLIC), withPrefix("get"), withAnnotation(annotation));

How to make a flat list out of list of lists?

The accepted answer did not work for me when dealing with text-based lists of variable lengths. Here is an alternate approach that did work for me.

l = ['aaa', 'bb', 'cccccc', ['xx', 'yyyyyyy']]

Accepted answer that did not work:

flat_list = [item for sublist in l for item in sublist]
print(flat_list)
['a', 'a', 'a', 'b', 'b', 'c', 'c', 'c', 'c', 'c', 'c', 'xx', 'yyyyyyy']

New proposed solution that did work for me:

flat_list = []
_ = [flat_list.extend(item) if isinstance(item, list) else flat_list.append(item) for item in l if item]
print(flat_list)
['aaa', 'bb', 'cccccc', 'xx', 'yyyyyyy']

How to handle Uncaught (in promise) DOMException: The play() request was interrupted by a call to pause()

In my case I had to wait for a user interaction, so I set a click or touchend listener.

const isMobile = navigator.maxTouchPoints || "ontouchstart" in document.documentElement;

function play(){
    audioEl.play()
}


document.body.addEventListener(isMobile ? "touchend" : "click", play, { once: true });

Intellij idea cannot resolve anything in maven

Unfortunately I ran into the same issue and I was head scratching why this is happening. I almost tried everything on this page and but none worked for me.

So , I tried to go the root of this problem; and the problem was (Atleast for me) that I was trying to open a maven project but pom file was not identified. So right clicking on the pom file and choosing "add as maven project" and then right clicking on the project -> Maven -> Reimport did all the magic for me :)

Hopefully this can be helpful for someone.

Where can I read the Console output in Visual Studio 2015

What may be happening is that your console is closing before you get a chance to see the output. I would add Console.ReadLine(); after your Console.WriteLine("Hello World"); so your code would look something like this:

static void Main(string[] args)
    {
        Console.WriteLine("Hello World");
        Console.ReadLine();

    }

This way, the console will display "Hello World" and a blinking cursor underneath. The Console.ReadLine(); is the key here, the program waits for the users input before closing the console window.

how to query LIST using linq

Well, the code you've given is invalid to start with - List is a generic type, and it has an Add method instead of add etc.

But you could do something like:

List<Person> list = new List<Person>
{
    new person{ID=1,Name="jhon",salary=2500},
    new person{ID=2,Name="Sena",salary=1500},
    new person{ID=3,Name="Max",salary=5500}.
    new person{ID=4,Name="Gen",salary=3500}
};

// The "Where" LINQ operator filters a sequence
var highEarners = list.Where(p => p.salary > 3000);

foreach (var person in highEarners)
{
    Console.WriteLine(person.Name);
}

If you want to learn details of what all the LINQ operators do, and how they can be implemented in LINQ to Objects, you might be interested in my Edulinq blog series.

Open terminal here in Mac OS finder

Check out Open Terminal Here. It may be the most similar to "Open Command Window Here." I used >cdto and this is very similar but this seems to be a little better at dealing with Spaces... but not perfect.

What it has that is very nice is the ability to "detect key-down events at the start of the application and used them to modify the behavior of the script" allowing the script to open a new tab in the front most terminal window when invoked by holding down ? key. Neat trick.

Also note PCheese's answer; it is probably more useful for heavy terminal users!

Can not deserialize instance of java.lang.String out of START_ARRAY token

The error is:

Can not deserialize instance of java.lang.String out of START_ARRAY token at [Source: line: 1, column: 1095] (through reference chain: JsonGen["platforms"])

In JSON, platforms look like this:

"platforms": [
    {
        "platform": "iphone"
    },
    {
        "platform": "ipad"
    },
    {
        "platform": "android_phone"
    },
    {
        "platform": "android_tablet"
    }
]

So try change your pojo to something like this:

private List platforms;

public List getPlatforms(){
    return this.platforms;
}

public void setPlatforms(List platforms){
    this.platforms = platforms;
}

EDIT: you will need change mobile_networks too. Will look like this:

private List mobile_networks;

public List getMobile_networks() {
    return mobile_networks;
}

public void setMobile_networks(List mobile_networks) {
    this.mobile_networks = mobile_networks;
}

How to use <DllImport> in VB.NET?

You have to add Imports System.Runtime.InteropServices to the top of your source file.

Alternatively, you can fully qualify attribute name:

<System.Runtime.InteropService.DllImport("user32.dll", _
    SetLastError:=True, CharSet:=CharSet.Auto)> _

In Ruby, how do I skip a loop in a .each loop, similar to 'continue'

next - it's like return, but for blocks! (So you can use this in any proc/lambda too.)

That means you can also say next n to "return" n from the block. For instance:

puts [1, 2, 3].map do |e|
  next 42 if e == 2
  e
end.inject(&:+)

This will yield 46.

Note that return always returns from the closest def, and never a block; if there's no surrounding def, returning is an error.

Using return from within a block intentionally can be confusing. For instance:

def my_fun
  [1, 2, 3].map do |e|
    return "Hello." if e == 2
    e
  end
end

my_fun will result in "Hello.", not [1, "Hello.", 2], because the return keyword pertains to the outer def, not the inner block.

What is LDAP used for?

To take the definitions the other mentioned earlier a bit further, how about this perspective...

LDAP is Lightweight Directory Access Protocol. DAP, is an X.500 notion, and in X.500 is VERY heavy weight! (It sort of requires a full 7 layer ISO network stack, which basically only IBM's SNA protocol ever realistically implemented).

There are many other approaches to DAP. Novell has one called NDAP (NCP Novell Core Protocols are the transport, and NDAP is how it reads the directory).

LDAP is just a very lightweight DAP, as the name suggests.

What is the default root pasword for MySQL 5.7

MySQL server 5.7 was already installed by default on my new Linux Mint 19.

But, what's the MySQL root password? It turns out that:

The default installation uses auth_socket for authentication, in lieu of passwords!

It allows a password-free login, provided that one is logged into the Linux system with the same user name. To login as the MySQL root user, one can use sudo:

sudo mysql --user=root

But how to then change the root password? To illustrate what's going on, I created a new user "me", with full privileges, with:

mysql> CREATE USER 'me'@'localhost' IDENTIFIED BY 'my_new_password';
mysql> GRANT ALL PRIVILEGES ON *.* TO 'me'@'localhost' WITH GRANT OPTION;
mysql> FLUSH PRIVILEGES;

Comparing "me" with "root":

mysql> SELECT user, plugin, HEX(authentication_string)  FROM mysql.user WHERE user = 'me' or user = 'root';
+------+-----------------------+----------------------------------------------------------------------------+
| user | plugin                | HEX(authentication_string)                                                 |
+------+-----------------------+----------------------------------------------------------------------------+
| root | auth_socket           |                                                                            |
| me   | mysql_native_password | 2A393846353030304545453239394634323734333139354241344642413245373537313... |
+------+-----------------------+----------------------------------------------------------------------------+

Because it's using auth_socket, the root password cannot be changed: the SET PASSWORD command fails, and mysql_secure_installation desn't attain anything...

==> To zap this alternate authentication mode and return the MySQL root user to using passwords:

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'SOME_NEW_ROOT_PASSWORD';

A good explanation.

More details from the MySQL manual.

Add hover text without javascript like we hover on a user's reputation

Often i reach for the abbreviation html tag in this situation.

<abbr title="Hover">Text</abbr>

https://www.w3schools.com/tags/tag_abbr.asp

How to display Oracle schema size with SQL query?

select T.TABLE_NAME, T.TABLESPACE_NAME, t.avg_row_len*t.num_rows from dba_tables t
order by T.TABLE_NAME asc

See e.g. http://www.dba-oracle.com/t_script_oracle_table_size.htm for more options

Build query string for System.Net.HttpClient get

I couldn't find a better solution than creating a extension method to convert a Dictionary to QueryStringFormat. The solution proposed by Waleed A.K. is good as well.

Follow my solution:

Create the extension method:

public static class DictionaryExt
{
    public static string ToQueryString<TKey, TValue>(this Dictionary<TKey, TValue> dictionary)
    {
        return ToQueryString<TKey, TValue>(dictionary, "?");
    }

    public static string ToQueryString<TKey, TValue>(this Dictionary<TKey, TValue> dictionary, string startupDelimiter)
    {
        string result = string.Empty;
        foreach (var item in dictionary)
        {
            if (string.IsNullOrEmpty(result))
                result += startupDelimiter; // "?";
            else
                result += "&";

            result += string.Format("{0}={1}", item.Key, item.Value);
        }
        return result;
    }
}

And them:

var param = new Dictionary<string, string>
          {
            { "param1", "value1" },
            { "param2", "value2" },
          };
param.ToQueryString(); //By default will add (?) question mark at begining
//"?param1=value1&param2=value2"
param.ToQueryString("&"); //Will add (&)
//"&param1=value1&param2=value2"
param.ToQueryString(""); //Won't add anything
//"param1=value1&param2=value2"

How to use shell commands in Makefile

With:

FILES = $(shell ls)

indented underneath all like that, it's a build command. So this expands $(shell ls), then tries to run the command FILES ....

If FILES is supposed to be a make variable, these variables need to be assigned outside the recipe portion, e.g.:

FILES = $(shell ls)
all:
        echo $(FILES)

Of course, that means that FILES will be set to "output from ls" before running any of the commands that create the .tgz files. (Though as Kaz notes the variable is re-expanded each time, so eventually it will include the .tgz files; some make variants have FILES := ... to avoid this, for efficiency and/or correctness.1)

If FILES is supposed to be a shell variable, you can set it but you need to do it in shell-ese, with no spaces, and quoted:

all:
        FILES="$(shell ls)"

However, each line is run by a separate shell, so this variable will not survive to the next line, so you must then use it immediately:

        FILES="$(shell ls)"; echo $$FILES

This is all a bit silly since the shell will expand * (and other shell glob expressions) for you in the first place, so you can just:

        echo *

as your shell command.

Finally, as a general rule (not really applicable to this example): as esperanto notes in comments, using the output from ls is not completely reliable (some details depend on file names and sometimes even the version of ls; some versions of ls attempt to sanitize output in some cases). Thus, as l0b0 and idelic note, if you're using GNU make you can use $(wildcard) and $(subst ...) to accomplish everything inside make itself (avoiding any "weird characters in file name" issues). (In sh scripts, including the recipe portion of makefiles, another method is to use find ... -print0 | xargs -0 to avoid tripping over blanks, newlines, control characters, and so on.)


1The GNU Make documentation notes further that POSIX make added ::= assignment in 2012. I have not found a quick reference link to a POSIX document for this, nor do I know off-hand which make variants support ::= assignment, although GNU make does today, with the same meaning as :=, i.e., do the assignment right now with expansion.

Note that VAR := $(shell command args...) can also be spelled VAR != command args... in several make variants, including all modern GNU and BSD variants as far as I know. These other variants do not have $(shell) so using VAR != command args... is superior in both being shorter and working in more variants.

Promise Error: Objects are not valid as a React child

You can't just return an array of objects because there's nothing telling React how to render that. You'll need to return an array of components or elements like:

render: function() {
  return (
    <span>
      // This will go through all the elements in arrayFromJson and
      // render each one as a <SomeComponent /> with data from the object
      {this.state.arrayFromJson.map(function(object) {
        return (
          <SomeComponent key={object.id} data={object} />
        );
      })}
    </span>
  );
}

Incorrect syntax near ''

Panagiotis Kanavos is right, sometimes copy and paste T-SQL can make appear unwanted characters...

I finally found a simple and fast way (only Notepad++ needed) to detect which character is wrong, without having to manually rewrite the whole statement: there is no need to save any file to disk.

It's pretty quick, in Notepad++:

  • Click "New file"
  • Check under the menu "Encoding": the value should be "Encode in UTF-8"; set it if it's not
  • Paste your text enter image description here
  • From Encoding menu, now click "Encode in ANSI" and check again your text enter image description here

You should easily find the wrong character(s)

How to make the tab character 4 spaces instead of 8 spaces in nano?

Command-line flag

From man nano:

-T cols (--tabsize=cols)
    Set the size (width) of a tab to cols columns.
    The value of cols must be greater than 0. The default value is 8.
-E (--tabstospaces)
    Convert typed tabs to spaces.

For example, to set the tab size to 4, replace tabs with spaces, and edit the file "foo.txt", you would run the command:

nano -ET4 foo.txt

Config file

From man nanorc:

set tabsize n
    Use a tab size of n columns. The value of n must be greater than 0.
    The default value is 8.
set/unset tabstospaces
    Convert typed tabs to spaces.

Edit your ~/.nanorc file (create it if it does not exist), and add those commands to it. For example:

set tabsize 4
set tabstospaces

Nano will use these settings by default whenever it is launched, but command-line flags will override them.

Egit rejected non-fast-forward

Open git view :

1- select your project and choose merge 2- Select remote tracking 3- click ok

Git will merge the remote branch with local repository

4- then push

CAST to DECIMAL in MySQL

If you need a lot of decimal numbers, in this example 17, I share with you MySql code:

This is the calculate:

=(9/1147)*100

SELECT TRUNCATE(((CAST(9 AS DECIMAL(30,20))/1147)*100),17);

Insert line at middle of file with Python?

You can just read the data into a list and insert the new record where you want.

names = []
with open('names.txt', 'r+') as fd:
    for line in fd:
        names.append(line.split(' ')[-1].strip())

    names.insert(2, "Charlie") # element 2 will be 3. in your list
    fd.seek(0)
    fd.truncate()

    for i in xrange(len(names)):
        fd.write("%d. %s\n" %(i + 1, names[i]))

How to compile and run a C/C++ program on the Android system

if you have installed NDK succesfully then start with it sample application

http://developer.android.com/sdk/ndk/overview.html#samples

if you are interested another ways of this then may this will help

http://shareprogrammingtips.blogspot.com/2018/07/cross-compile-cc-based-programs-and-run.html

I also want to know is it possible to push the compiled binary into android device or AVD and run using the terminal of the android device or AVD?

here you can see NestedVM

NestedVM provides binary translation for Java Bytecode. This is done by having GCC compile to a MIPS binary which is then translated to a Java class file. Hence any application written in C, C++, Fortran, or any other language supported by GCC can be run in 100% pure Java with no source changes.


Example: Cross compile Hello world C program and run it on android

How to disable SSL certificate checking with Spring RestTemplate?

@Bean(name = "restTemplateByPassSSL")
public RestTemplate restTemplateByPassSSL()
        throws KeyStoreException, NoSuchAlgorithmException, KeyManagementException {
    TrustStrategy acceptingTrustStrategy = (X509Certificate[] chain, String authType) -> true;
    HostnameVerifier hostnameVerifier = (s, sslSession) -> true;
    SSLContext sslContext = SSLContexts.custom().loadTrustMaterial(null, acceptingTrustStrategy).build();
    SSLConnectionSocketFactory csf = new SSLConnectionSocketFactory(sslContext, hostnameVerifier);
    CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(csf).build();
    HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory();
    requestFactory.setHttpClient(httpClient);

    return new RestTemplate(requestFactory);
}

Copy entire directory contents to another directory?

public static void copyFolder(File source, File destination)
{
    if (source.isDirectory())
    {
        if (!destination.exists())
        {
            destination.mkdirs();
        }

        String files[] = source.list();

        for (String file : files)
        {
            File srcFile = new File(source, file);
            File destFile = new File(destination, file);

            copyFolder(srcFile, destFile);
        }
    }
    else
    {
        InputStream in = null;
        OutputStream out = null;

        try
        {
            in = new FileInputStream(source);
            out = new FileOutputStream(destination);

            byte[] buffer = new byte[1024];

            int length;
            while ((length = in.read(buffer)) > 0)
            {
                out.write(buffer, 0, length);
            }
        }
        catch (Exception e)
        {
            try
            {
                in.close();
            }
            catch (IOException e1)
            {
                e1.printStackTrace();
            }

            try
            {
                out.close();
            }
            catch (IOException e1)
            {
                e1.printStackTrace();
            }
        }
    }
}

How can I print the contents of a hash in Perl?

Data::Dumper is your friend.

use Data::Dumper;
my %hash = ('abc' => 123, 'def' => [4,5,6]);
print Dumper(\%hash);

will output

$VAR1 = {
          'def' => [
                     4,
                     5,
                     6
                   ],
          'abc' => 123
        };

Android Location Manager, Get GPS location ,if no GPS then get to Network Provider location

The recommended way to do this is to use LocationClient:

First, define location update interval values. Adjust this to your needs.

private static final int MILLISECONDS_PER_SECOND = 1000;
private static final long UPDATE_INTERVAL = MILLISECONDS_PER_SECOND * UPDATE_INTERVAL_IN_SECONDS;
private static final int FASTEST_INTERVAL_IN_SECONDS = 1;
private static final long FASTEST_INTERVAL = MILLISECONDS_PER_SECOND * FASTEST_INTERVAL_IN_SECONDS;

Have your Activity implement GooglePlayServicesClient.ConnectionCallbacks, GooglePlayServicesClient.OnConnectionFailedListener, and LocationListener.

public class LocationActivity extends Activity implements 
GooglePlayServicesClient.ConnectionCallbacks, GooglePlayServicesClient.OnConnectionFailedListener, LocationListener {}

Then, set up a LocationClientin the onCreate() method of your Activity:

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    mLocationClient = new LocationClient(this, this, this);

    mLocationRequest = LocationRequest.create();
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    mLocationRequest.setInterval(UPDATE_INTERVAL);
    mLocationRequest.setFastestInterval(FASTEST_INTERVAL);
}

Add the required methods to your Activity; onConnected() is the method that is called when the LocationClientconnects. onLocationChanged() is where you'll retrieve the most up-to-date location.

@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
    Log.w(TAG, "Location client connection failed");
}

@Override
public void onConnected(Bundle dataBundle) {
    Log.d(TAG, "Location client connected");
    mLocationClient.requestLocationUpdates(mLocationRequest, this); 
}

@Override
public void onDisconnected() {
    Log.d(TAG, "Location client disconnected");
}

@Override
public void onLocationChanged(Location location) {
    if (location != null) {
        Log.d(TAG, "Updated Location: " + Double.toString(location.getLatitude()) + "," + Double.toString(location.getLongitude()));
    } else {
        Log.d(TAG, "Updated location NULL");
    } 
}     

Be sure to connect/disconnect the LocationClient so it's only using extra battery when absolutely necessary and so the GPS doesn't run indefinitely. The LocationClient must be connected in order to get data from it.

public void onResume() {
    super.onResume();
    mLocationClient.connect();
}

public void onStop() {
    if (mLocationClient.isConnected()) {
        mLocationClient.removeLocationUpdates(this);
    }
    mLocationClient.disconnect();
    super.onStop();
}

Get the user's location. First try using the LocationClient; if that fails, fall back to the LocationManager.

public Location getLocation() {
    if (mLocationClient != null && mLocationClient.isConnected()) {
        return mLocationClient.getLastLocation();
    } else {
        LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
        if (locationManager != null) {
            Location lastKnownLocationGPS = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
            if (lastKnownLocationGPS != null) {
                return lastKnownLocationGPS;
            } else {
                return locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
            }
        } else {
            return null;
        }
    }
}

Rails has_many with alias name

Give this a shot:

has_many :jobs, foreign_key: "user_id", class_name: "Task"

Note, that :as is used for polymorphic associations.

How to display JavaScript variables in a HTML page without document.write

hi here is a simple example: <div id="test">content</div> and

var test = 5;
document.getElementById('test').innerHTML = test;

and you can test it here : http://jsfiddle.net/SLbKX/

Non-resolvable parent POM using Maven 3.0.3 and relativePath notation

Please check in logs if you have http.HttpWagon$__sisu1:Cannot find 'basicAuthScope' this error or warning also, if so you need to use maven 3.2.5 version, which will resolve error.

TabLayout tab selection

Kotlin fix

viewPager.currentItem = 0

tabs.setupWithViewPager(viewPager)

Is there a built-in function to print all the current properties and values of an object?

dir has been mentioned, but that'll only give you the attributes' names. If you want their values as well try __dict__.

class O:
   def __init__ (self):
      self.value = 3

o = O()

Here is the output:

>>> o.__dict__

{'value': 3}

Get cookie by name

reference: https://developer.mozilla.org/en-US/docs/Web/API/Document/cookie

document.cookie = "test1=Hello";
document.cookie = "test2=World";

var cookieValue = document.cookie.replace(/(?:(?:^|.*;\s*)test2\s*\=\s*([^;]*).*$)|^.*$/, "$1");

  alert(cookieValue);

Column calculated from another column?

MySQL 5.7 supports computed columns. They call it "Generated Columns" and the syntax is a little weird, but it supports the same options I see in other databases.

https://dev.mysql.com/doc/refman/5.7/en/create-table.html#create-table-generated-columns