Programs & Examples On #Seekbar

Seek bar is a UI control analogous to a slider. In Android, it is an extension of ProgressBar with a draggable thumb.

Implementing a slider (SeekBar) in Android

How to implement a SeekBar

enter image description here

Add the SeekBar to your layout

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/textView"
        android:layout_margin="20dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <SeekBar
        android:id="@+id/seekBar"
        android:max="100"
        android:progress="50"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

Notes

  • max is the highest value that the seek bar can go to. The default is 100. The minimum is 0. The xml min value is only available from API 26, but you can just programmatically convert the 0-100 range to whatever you need for earlier versions.
  • progress is the initial position of the slider dot (called a "thumb").
  • For a vertical SeekBar use android:rotation="270".

Listen for changes in code

public class MainActivity extends AppCompatActivity {

    TextView tvProgressLabel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // set a change listener on the SeekBar
        SeekBar seekBar = findViewById(R.id.seekBar);
        seekBar.setOnSeekBarChangeListener(seekBarChangeListener);

        int progress = seekBar.getProgress();
        tvProgressLabel = findViewById(R.id.textView);
        tvProgressLabel.setText("Progress: " + progress);
    }

    SeekBar.OnSeekBarChangeListener seekBarChangeListener = new SeekBar.OnSeekBarChangeListener() {

        @Override
        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
            // updated continuously as the user slides the thumb
            tvProgressLabel.setText("Progress: " + progress);
        }

        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {
            // called when the user first touches the SeekBar
        }

        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {
            // called after the user finishes moving the SeekBar
        }
    };
}

Notes

  • If you don't need to do any updates while the user is moving the seekbar, then you can just update the UI in onStopTrackingTouch.

See also

Custom seekbar (thumb size, color and background)

For future readers!

Starting from material-components-android 1.2.0-alpha01, you can use new slider component

ex:

Modify thumbSize, thumbColor, trackColor accordingly.

<com.google.android.material.slider.Slider
        android:id="@+id/slider"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:valueFrom="20f"
        android:valueTo="70f"
        android:stepSize="10"
        app:thumbRadius="20dp"
        app:thumbColor="@color/colorAccent"
        app:trackColor="@android:color/darker_gray"
        />

Note: Track corners are not round.

Android SeekBar setOnSeekBarChangeListener

Seekbar called onProgressChanged method when we initialize first time. We can skip by using below code We need to check boolean it return false when initialize automatically

volumeManager.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
                if(b){
                    mAudioManager.setStreamVolume(AudioManager.STREAM_MUSIC, i, 0);
                }
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {

            }
        });

How to make a vertical SeekBar in Android?

Note, it appears to me that if you change the width the thumb width does not change correctly. I didn't take the time to fix it right, i just fixed it for my case. Here is what i did. Couldn't figure out how to contact the original creator.

public void setThumb(Drawable thumb) {
    if (thumb != null) {
        thumb.setCallback(this);

        // Assuming the thumb drawable is symmetric, set the thumb offset
        // such that the thumb will hang halfway off either edge of the
        // progress bar.
        //This was orginally divided by 2, seems you have to adjust here when you adjust width.
        mThumbOffset = (int)thumb.getIntrinsicHeight();
    }

How to set seekbar min and max value

There is no option to set a min or max value in seekbar , so you can use a formula here to scale your value.

Desired_value = ( progress * ( Max_value - Min_value) / 100 ) + Min_value

I have tested this formula in many examples. In your example, if the progressBar is the middle(i.e. progress = 50 ) and your Min_val and Max_val are 60 and 180 respectively, then this formula will give you the Desired_value '120'.

How to round a number to significant figures in Python

To directly answer the question, here's my version using naming from the R function:

import math

def signif(x, digits=6):
    if x == 0 or not math.isfinite(x):
        return x
    digits -= math.ceil(math.log10(abs(x)))
    return round(x, digits)

My main reason for posting this answer are the comments complaining that "0.075" rounds to 0.07 rather than 0.08. This is due, as pointed out by "Novice C", to a combination of floating point arithmetic having both finite precision and a base-2 representation. The nearest number to 0.075 that can actually be represented is slightly smaller, hence rounding comes out differently than you might naively expect.

Also note that this applies to any use of non-decimal floating point arithmetic, e.g. C and Java both have the same issue.

To show in more detail, we ask Python to format the number in "hex" format:

0.075.hex()

which gives us: 0x1.3333333333333p-4. The reason for doing this is that the normal decimal representation often involves rounding and hence is not how the computer actually "sees" the number. If you're not used to this format, a couple of useful references are the Python docs and the C standard.

To show how these numbers work a bit, we can get back to our starting point by doing:

0x13333333333333 / 16**13 * 2**-4

which should should print out 0.075. 16**13 is because there are 13 hexadecimal digits after the decimal point, and 2**-4 is because hex exponents are base-2.

Now we have some idea of how floats are represented we can use the decimal module to give us some more precision, showing us what's going on:

from decimal import Decimal

Decimal(0x13333333333333) / 16**13 / 2**4

giving: 0.07499999999999999722444243844 and hopefully explaining why round(0.075, 2) evaluates to 0.07

Java: splitting the filename into a base and extension

I know others have mentioned String.split, but here is a variant that only yields two tokens (the base and the extension):

String[] tokens = fileName.split("\\.(?=[^\\.]+$)");

For example:

"test.cool.awesome.txt".split("\\.(?=[^\\.]+$)");

Yields:

["test.cool.awesome", "txt"]

The regular expression tells Java to split on any period that is followed by any number of non-periods, followed by the end of input. There is only one period that matches this definition (namely, the last period).

Technically Regexically speaking, this technique is called zero-width positive lookahead.


BTW, if you want to split a path and get the full filename including but not limited to the dot extension, using a path with forward slashes,

    String[] tokens = dir.split(".+?/(?=[^/]+$)");

For example:

    String dir = "/foo/bar/bam/boozled"; 
    String[] tokens = dir.split(".+?/(?=[^/]+$)");
    // [ "/foo/bar/bam/" "boozled" ] 

How to stop an animation (cancel() does not work)

If you are using the animation listener, set v.setAnimationListener(null). Use the following code with all options.

v.getAnimation().cancel();
v.clearAnimation();
animation.setAnimationListener(null);

List of all unique characters in a string?

Store Unique characters in list

Method 1:

uniue_char = list(set('aaabcabccd'))
#['a', 'b', 'c', 'd']

Method 2: By Loop ( Complex )

uniue_char = []
for c in 'aaabcabccd':
    if not c in uniue_char:
        uniue_char.append(c)
print(uniue_char)
#['a', 'b', 'c', 'd']

React Hook "useState" is called in function "app" which is neither a React function component or a custom React Hook function

May be you have added the useEffect that depends on the condition before the one with no condition

EX:

useEffect(() => {
  _anyFunction();
}, []);
    
useEffect(()=> {
  anyCode....
}, [response]);

ReDim Preserve to a Multi-Dimensional Array in Visual Basic 6

You can use a user defined type containing an array of strings which will be the inner array. Then you can use an array of this user defined type as your outer array.

Have a look at the following test project:

'1 form with:
'  command button: name=Command1
'  command button: name=Command2
Option Explicit

Private Type MyArray
  strInner() As String
End Type

Private mudtOuter() As MyArray

Private Sub Command1_Click()
  'change the dimensens of the outer array, and fill the extra elements with "1"
  Dim intOuter As Integer
  Dim intInner As Integer
  Dim intOldOuter As Integer
  intOldOuter = UBound(mudtOuter)
  ReDim Preserve mudtOuter(intOldOuter + 2) As MyArray
  For intOuter = intOldOuter + 1 To UBound(mudtOuter)
    ReDim mudtOuter(intOuter).strInner(intOuter) As String
    For intInner = 0 To UBound(mudtOuter(intOuter).strInner)
      mudtOuter(intOuter).strInner(intInner) = "1"
    Next intInner
  Next intOuter
End Sub

Private Sub Command2_Click()
  'change the dimensions of the middle inner array, and fill the extra elements with "2"
  Dim intOuter As Integer
  Dim intInner As Integer
  Dim intOldInner As Integer
  intOuter = UBound(mudtOuter) / 2
  intOldInner = UBound(mudtOuter(intOuter).strInner)
  ReDim Preserve mudtOuter(intOuter).strInner(intOldInner + 5) As String
  For intInner = intOldInner + 1 To UBound(mudtOuter(intOuter).strInner)
    mudtOuter(intOuter).strInner(intInner) = "2"
  Next intInner
End Sub

Private Sub Form_Click()
  'clear the form and print the outer,inner arrays
  Dim intOuter As Integer
  Dim intInner As Integer
  Cls
  For intOuter = 0 To UBound(mudtOuter)
    For intInner = 0 To UBound(mudtOuter(intOuter).strInner)
      Print CStr(intOuter) & "," & CStr(intInner) & " = " & mudtOuter(intOuter).strInner(intInner)
    Next intInner
    Print "" 'add an empty line between the outer array elements
  Next intOuter
End Sub

Private Sub Form_Load()
  'init the arrays
  Dim intOuter As Integer
  Dim intInner As Integer
  ReDim mudtOuter(5) As MyArray
  For intOuter = 0 To UBound(mudtOuter)
    ReDim mudtOuter(intOuter).strInner(intOuter) As String
    For intInner = 0 To UBound(mudtOuter(intOuter).strInner)
      mudtOuter(intOuter).strInner(intInner) = CStr((intOuter + 1) * (intInner + 1))
    Next intInner
  Next intOuter
  WindowState = vbMaximized
End Sub

Run the project, and click on the form to display the contents of the arrays.

Click on Command1 to enlarge the outer array, and click on the form again to show the results.

Click on Command2 to enlarge an inner array, and click on the form again to show the results.

Be careful though: when you redim the outer array, you also have to redim the inner arrays for all the new elements of the outer array

Reading the selected value from asp:RadioButtonList using jQuery

I found a simple solution, try this:

var Ocasiao = "";    
$('#ctl00_rdlOcasioesMarcas input').each(function() { if (this.checked) { Ocasiao = this.value } });

PHP, getting variable from another php-file

You could also use file_get_contents

 $url_a="http://127.0.0.1/get_value.php?line=a&shift=1&tgl=2017-01-01";
 $data_a=file_get_contents($url_a);

 echo $data_a;

Python conversion between coordinates

The existing answers can be simplified:

from numpy import exp, abs, angle

def polar2z(r,theta):
    return r * exp( 1j * theta )

def z2polar(z):
    return ( abs(z), angle(z) )

Or even:

polar2z = lambda r,?: r * exp( 1j * ? )
z2polar = lambda z: ( abs(z), angle(z) )

Note these also work on arrays!

rS, thetaS = z2polar( [z1,z2,z3] )
zS = polar2z( rS, thetaS )

SQL Error: ORA-00933: SQL command not properly ended

Your query should look like

UPDATE table_name
SET column1=value, column2=value2,...
WHERE some_column=some_value

You can check the below question for help

Implementing INotifyPropertyChanged - does a better way exist?

I use the following extension method (using C# 6.0) to make the INPC implemenation as easy as possible:

public static bool ChangeProperty<T>(this PropertyChangedEventHandler propertyChanged, ref T field, T value, object sender,
    IEqualityComparer<T> comparer = null, [CallerMemberName] string propertyName = null)
{
    if (comparer == null)
        comparer = EqualityComparer<T>.Default;

    if (comparer.Equals(field, value))
    {
        return false;
    }
    else
    {
        field = value;
        propertyChanged?.Invoke(sender, new PropertyChangedEventArgs(propertyName));
        return true;
    }
}

The INPC implementation boils down to (you can either implement this every time or create a base class):

public class INPCBaseClass: INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected bool changeProperty<T>(ref T field, T value,
        IEqualityComparer<T> comparer = null, [CallerMemberName] string propertyName = null)
    {
        return PropertyChanged.ChangeProperty(ref field, value, this, comparer, propertyName);
    }
}

Then write your properties like this:

private string testProperty;
public string TestProperty
{
    get { return testProperty; }
    set { changeProperty(ref testProperty, value); }
}

NOTE: You can omit the [CallerMemberName] declaration in the extension method, if you want, but I wanted to keep it flexible.

If you have properties without a backing field you can overload changeProperty:

protected bool changeProperty<T>(T property, Action<T> set, T value,
    IEqualityComparer<T> comparer = null, [CallerMemberName] string propertyName = null)
{
    bool ret = changeProperty(ref property, value, comparer, propertyName);
    if (ret)
        set(property);
    return ret;
}

An example use would be:

public string MyTestProperty
{
    get { return base.TestProperty; }
    set { changeProperty(base.TestProperty, (x) => { base.TestProperty = x; }, value); }
}

Converting characters to integers in Java

As the documentation clearly states, Character.getNumericValue() returns the character's value as a digit.
It returns -1 if the character is not a digit.

If you want to get the numeric Unicode code point of a boxed Character object, you'll need to unbox it first:

int value = (int)c.charValue();

UnicodeEncodeError: 'ascii' codec can't encode character u'\xe9' in position 7: ordinal not in range(128)

You need to encode Unicode explicitly before writing to a file, otherwise Python does it for you with the default ASCII codec.

Pick an encoding and stick with it:

f.write(printinfo.encode('utf8') + '\n')

or use io.open() to create a file object that'll encode for you as you write to the file:

import io

f = io.open(filename, 'w', encoding='utf8')

You may want to read:

before continuing.

Generating HTML email body in C#

I use dotLiquid for exactly this task.

It takes a template, and fills special identifiers with the content of an anonymous object.

//define template
String templateSource = "<h1>{{Heading}}</h1>Dear {{UserName}},<br/><p>First part of the email body goes here");
Template bodyTemplate = Template.Parse(templateSource); // Parses and compiles the template source

//Create DTO for the renderer
var bodyDto = new {
    Heading = "Heading Here",
    UserName = userName
};
String bodyText = bodyTemplate.Render(Hash.FromAnonymousObject(bodyDto));

It also works with collections, see some online examples.

Adding an assets folder in Android Studio

An image of how to in Android Studio 1.5.1.

Within the "Android" project (see the drop-down in the topleft of my image), Right-click on the app...

enter image description here

Thymeleaf using path variables to th:href

A cleaner and easier way to do this

<a href="somepage.html" th:href="@{|/my/url/${variable}|}">A Link</a>

I found this solution in Thymeleaf Documentation on "4.8 Literal substitutions".

Why does .NET foreach loop throw NullRefException when collection is null?

Another extension method to work around this:

public static void ForEach<T>(this IEnumerable<T> items, Action<T> action)
{
    if(items == null) return;
    foreach (var item in items) action(item);
}

Consume in several ways:

(1) with a method that accepts T:

returnArray.ForEach(Console.WriteLine);

(2) with an expression:

returnArray.ForEach(i => UpdateStatus(string.Format("{0}% complete", i)));

(3) with a multiline anonymous method

int toCompare = 10;
returnArray.ForEach(i =>
{
    var thisInt = i;
    var next = i++;
    if(next > 10) Console.WriteLine("Match: {0}", i);
});

How to make an HTML back link?

history.go(-1) doesn't work if you click around in the 2nd domain or if the referrer is empty.

So we have to store the historyCount on arriving to this domain and go back the number of navigations in this side minus 1.


// if referrer is different from this site
if (!document.referrer.includes(window.location.host)) {
  // store current history length
  localStorage.setItem('historyLength', `${history.length}`);
}

// Return to stored referrer on logo click
document.querySelector('header .logo').addEventListener('click', 
  () =>
   history.go(Number(localStorage.getItem('historyLength')) - history.length -1)
);

Creating .pem file for APNS?

Launch the Terminal application and enter the following command after the prompt

  openssl pkcs12 -in CertificateName.p12 -out CertificateName.pem -nodes

Run bash script from Windows PowerShell

If you add the extension .SH to the environment variable PATHEXT, you will be able to run shell scripts from PowerShell by only using the script name with arguments:

PS> .\script.sh args

If you store your scripts in a directory that is included in your PATH environment variable, you can run it from anywhere, and omit the extension and path:

PS> script args

Note: sh.exe or another *nix shell must be associated with the .sh extension.

How to declare a static const char* in your header file?

If you're using Visual C++, you can non-portably do this using hints to the linker...

// In foo.h...

class Foo
{
public:
   static const char *Bar;
};

// Still in foo.h; doesn't need to be in a .cpp file...

__declspec(selectany)
const char *Foo::Bar = "Blah";

__declspec(selectany) means that even though Foo::Bar will get declared in multiple object files, the linker will only pick up one.

Keep in mind this will only work with the Microsoft toolchain. Don't expect this to be portable.

How to close a web page on a button click, a hyperlink or a link button click?

Assuming you're using WinForms, as it was the first thing I did when I was starting C# you need to create an event to close this form.

Lets say you've got a button called myNewButton. If you double click it on WinForms designer you will create an event. After that you just have to use this.Close

    private void myNewButton_Click(object sender, EventArgs e) {
        this.Close();
    }

And that should be it.

The only reason for this not working is that your Event is detached from button. But it should create new event if old one is no longer attached when you double click on the button in WinForms designer.

Properties private set;

Perhaps, you can have them marked as internal, and in this case only classes in your DAL or BL (assuming they are separate dlls) would be able to set it.

You could also supply a constructor that takes the fields and then only exposes them as properties.

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

I was getting A collection with cascade=”all-delete-orphan” was no longer referenced by the owning entity instance when I was setting parent.setChildren(new ArrayList<>()). When I changed to parent.getChildren().clear(), it solved the problem.

Check for more details: HibernateException - A collection with cascade="all-delete-orphan" was no longer referenced by the owning entity instance.

Call child method from parent

I wasn't satisfied with any of the solutions presented here. There is actually a very simple solution that can be done using pure Javascript without relying upon some React functionality other than the basic props object - and it gives you the benefit of communicating in either direction (parent -> child, child -> parent). You need to pass an object from the parent component to the child component. This object is what I refer to as a "bi-directional reference" or biRef for short. Basically, the object contains a reference to methods in the parent that the parent wants to expose. And the child component attaches methods to the object that the parent can call. Something like this:

// Parent component.
function MyParentComponent(props) {

   function someParentFunction() {
      // The child component can call this function.
   }

   function onButtonClick() {
       // Call the function inside the child component.
       biRef.someChildFunction();
   }

   // Add all the functions here that the child can call.
   var biRef = {
      someParentFunction: someParentFunction
   }

   return <div>
       <MyChildComponent biRef={biRef} />
       <Button onClick={onButtonClick} />
   </div>;
}


// Child component
function MyChildComponent(props) {

   function someChildFunction() {
      // The parent component can call this function.
   }


   function onButtonClick() {
      // Call the parent function.
      props.biRef.someParentFunction();
   }

   // Add all the child functions to props.biRef that you want the parent
   // to be able to call.
   props.biRef.someChildFunction = someChildFunction;

   return <div>
       <Button onClick={onButtonClick} />
   </div>;
}

The other advantage to this solution is that you can add a lot more functions in the parent and child while passing them from the parent to the child using only a single property.

An improvement over the code above is to not add the parent and child functions directly to the biRef object but rather to sub members. Parent functions should be added to a member called "parent" while the child functions should be added to a member called "child".

// Parent component.
function MyParentComponent(props) {

   function someParentFunction() {
      // The child component can call this function.
   }

   function onButtonClick() {
       // Call the function inside the child component.
       biRef.child.someChildFunction();
   }

   // Add all the functions here that the child can call.
   var biRef = {
      parent: {
          someParentFunction: someParentFunction
      }
   }

   return <div>
       <MyChildComponent biRef={biRef} />
       <Button onClick={onButtonClick} />
   </div>;
}


// Child component
function MyChildComponent(props) {

   function someChildFunction() {
      // The parent component can call this function.
   }


   function onButtonClick() {
      // Call the parent function.
      props.biRef.parent.someParentFunction();
   }

   // Add all the child functions to props.biRef that you want the parent
   // to be able to call.
   props.biRef {
       child: {
            someChildFunction: someChildFunction
       }
   }

   return <div>
       <Button onClick={onButtonClick} />
   </div>;
}

By placing parent and child functions into separate members of the biRef object, you 'll have a clean separation between the two and easily see which ones belong to parent or child. It also helps to prevent a child component from accidentally overwriting a parent function if the same function appears in both.

One last thing is that if you note, the parent component creates the biRef object with var whereas the child component accesses it through the props object. It might be tempting to not define the biRef object in the parent and access it from its parent through its own props parameter (which might be the case in a hierarchy of UI elements). This is risky because the child may think a function it is calling on the parent belongs to the parent when it might actually belong to a grandparent. There's nothing wrong with this as long as you are aware of it. Unless you have a reason for supporting some hierarchy beyond a parent/child relationship, it's best to create the biRef in your parent component.

What does the 'static' keyword do in a class?

I have developed a liking for static methods (only, if possible) in "helper" classes.

The calling class need not create another member (instance) variable of the helper class. You just call the methods of the helper class. Also the helper class is improved because you no longer need a constructor, and you need no member (instance) variables.

There are probably other advantages.

How to get the fields in an Object via reflection?

You can use Class#getDeclaredFields() to get all declared fields of the class. You can use Field#get() to get the value.

In short:

Object someObject = getItSomehow();
for (Field field : someObject.getClass().getDeclaredFields()) {
    field.setAccessible(true); // You might want to set modifier to public first.
    Object value = field.get(someObject); 
    if (value != null) {
        System.out.println(field.getName() + "=" + value);
    }
}

To learn more about reflection, check the Sun tutorial on the subject.


That said, the fields does not necessarily all represent properties of a VO. You would rather like to determine the public methods starting with get or is and then invoke it to grab the real property values.

for (Method method : someObject.getClass().getDeclaredMethods()) {
    if (Modifier.isPublic(method.getModifiers())
        && method.getParameterTypes().length == 0
        && method.getReturnType() != void.class
        && (method.getName().startsWith("get") || method.getName().startsWith("is"))
    ) {
        Object value = method.invoke(someObject);
        if (value != null) {
            System.out.println(method.getName() + "=" + value);
        }
    }
}

That in turn said, there may be more elegant ways to solve your actual problem. If you elaborate a bit more about the functional requirement for which you think that this is the right solution, then we may be able to suggest the right solution. There are many, many tools available to massage javabeans.

How do you automatically set text box to Uppercase?

<script type="text/javascript">
    function upperCaseF(a){
    setTimeout(function(){
        a.value = a.value.toUpperCase();
    }, 1);
}
</script>

<input type="text" required="" name="partno" class="form-control" placeholder="Enter a Part No*" onkeydown="upperCaseF(this)">

Deserialize JSON with C#

Very easily we can parse JSON content with the help of dictionary and JavaScriptSerializer. Here is the sample code by which I parse JSON content from an ashx file.

var jss = new JavaScriptSerializer();
string json = new StreamReader(context.Request.InputStream).ReadToEnd();
Dictionary<string, string> sData = jss.Deserialize<Dictionary<string, string>>(json);
string _Name = sData["Name"].ToString();
string _Subject = sData["Subject"].ToString();
string _Email = sData["Email"].ToString();
string _Details = sData["Details"].ToString();

Animation fade in and out

FOR FADE add this first line with your animation's object.

.animate().alpha(1).setDuration(2000);

FOR EXAMPLEI USED LottieAnimation

How to change a <select> value from JavaScript

I found that doing document.getElementById("select").value = "defaultValue" wont work.

You must be experiencing a separate bug, as this works fine in this live demo.

And here's the full working code in case you are interested:

<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="content-type" content="text/html; charset=UTF-8">
    <title>Demo</title>
    <script type="text/javascript">
        var selectFunction = function() {
            document.getElementById("select").value = "defaultValue";
        };
    </script>
</head>
<body>
    <select id="select">
        <option value="defaultValue">Default</option>
        <option value="Option1">Option1</option>
        <option value="Option2">Option2</option>    
    </select>
    <input type="button" value="CHANGE" onclick="selectFunction()" />
</body>
</html>

How to assign string to bytes array

Ended up creating array specific methods to do this. Much like the encoding/binary package with specific methods for each int type. For example binary.BigEndian.PutUint16([]byte, uint16).

func byte16PutString(s string) [16]byte {
    var a [16]byte
    if len(s) > 16 {
        copy(a[:], s)
    } else {
        copy(a[16-len(s):], s)
    }
    return a
}

var b [16]byte
b = byte16PutString("abc")
fmt.Printf("%v\n", b)

Output:

[0 0 0 0 0 0 0 0 0 0 0 0 0 97 98 99]

Notice how I wanted padding on the left, not the right.

http://play.golang.org/p/7tNumnJaiN

Mounting multiple volumes on a docker container?

You can use -v option multiple times in docker run command to mount multiple directory in container:

docker run -t -i \
  -v '/on/my/host/test1:/on/the/container/test1' \
  -v '/on/my/host/test2:/on/the/container/test2' \
  ubuntu /bin/bash

Setting focus to a textbox control

create a textbox:

 <TextBox Name="tb">
 ..hello..
</TextBox>

focus() ---> it is used to set input focus to the textbox control

tb.focus()

How to use JavaScript source maps (.map files)?

  • How can a developer use it?

I didn't find answer for this in the comments, here is how can be used:

  1. Don't link your js.map file in your index.html file (no need for that)
  2. Minifiacation tools (good ones) add a comment to your .min.js file:

    //# sourceMappingURL=yourFileName.min.js.map

which will connect your .map file.

When the min.js and js.map files are ready...

  1. Chrome: Open dev-tools, navigate to Sources tab, You will see sources folder, where un-minified applications files are kept.

`export const` vs. `export default` in ES6

It's a named export vs a default export. export const is a named export that exports a const declaration or declarations.

To emphasize: what matters here is the export keyword as const is used to declare a const declaration or declarations. export may also be applied to other declarations such as class or function declarations.

Default Export (export default)

You can have one default export per file. When you import you have to specify a name and import like so:

import MyDefaultExport from "./MyFileWithADefaultExport";

You can give this any name you like.

Named Export (export)

With named exports, you can have multiple named exports per file. Then import the specific exports you want surrounded in braces:

// ex. importing multiple exports:
import { MyClass, MyOtherClass } from "./MyClass";
// ex. giving a named import a different name by using "as":
import { MyClass2 as MyClass2Alias } from "./MyClass2";

// use MyClass, MyOtherClass, and MyClass2Alias here

Or it's possible to use a default along with named imports in the same statement:

import MyDefaultExport, { MyClass, MyOtherClass} from "./MyClass";

Namespace Import

It's also possible to import everything from the file on an object:

import * as MyClasses from "./MyClass";
// use MyClasses.MyClass, MyClasses.MyOtherClass and MyClasses.default here

Notes

  • The syntax favours default exports as slightly more concise because their use case is more common (See the discussion here).
  • A default export is actually a named export with the name default so you are able to import it with a named import:

    import { default as MyDefaultExport } from "./MyFileWithADefaultExport";
    

CSS Printing: Avoiding cut-in-half DIVs between pages?

Only a partial solution: The only way I could get this to work for IE was to wrap each div in it's own table and set the page-break-inside on the table to avoid.

Key value pairs using JSON

I see what you are trying to ask and I think this is the simplest answer to what you are looking for, given you might not know how many key pairs your are being sent.

Simple Key Pair JSON structure

var data = {
    'XXXXXX' : '100.0',
    'YYYYYYY' : '200.0',
    'ZZZZZZZ' : '500.0',
}

Usage JavaScript code to access the key pairs

for (var key in data) 
  { if (!data.hasOwnProperty(key))
    { continue; } 
    console.log(key + ' -> ' +  data[key]);
  };

Console output should look like this

XXXXXX -> 100.0 
YYYYYYY -> 200.0 
ZZZZZZZ -> 500.0

Here is a JSFiddle to show how it works.

Android requires compiler compliance level 5.0 or 6.0. Found '1.7' instead. Please use Android Tools > Fix Project Properties

Following worked for me

Enable project-specific settings and set the compliance level to 1.6

How can you do that?

In your Eclipse Package Explorer 3rd click on your project and select properties. Properties Window will open. Select Java Compiler on the left panel of the window. Now Enable project specific settings and set the Complier compliance level to 1.6. Select Apply and then OK.

curl Failed to connect to localhost port 80

I also had problem with refused connection on port 80. I didn't use localhost.

curl --data-binary "@/textfile.txt" "http://www.myserver.com/123.php"

Problem was that I had umlauts äåö in my textfile.txt.

Get value of a specific object property in C# without knowing the class behind

Use reflection

System.Reflection.PropertyInfo pi = item.GetType().GetProperty("name");
String name = (String)(pi.GetValue(item, null));

JavaScript sleep/wait before continuing

JS does not have a sleep function, it has setTimeout() or setInterval() functions.

If you can move the code that you need to run after the pause into the setTimeout() callback, you can do something like this:

//code before the pause
setTimeout(function(){
    //do what you need here
}, 2000);

see example here : http://jsfiddle.net/9LZQp/

This won't halt the execution of your script, but due to the fact that setTimeout() is an asynchronous function, this code

console.log("HELLO");
setTimeout(function(){
    console.log("THIS IS");
}, 2000);
console.log("DOG");

will print this in the console:

HELLO
DOG
THIS IS

(note that DOG is printed before THIS IS)


You can use the following code to simulate a sleep for short periods of time:

function sleep(milliseconds) {
  var start = new Date().getTime();
  for (var i = 0; i < 1e7; i++) {
    if ((new Date().getTime() - start) > milliseconds){
      break;
    }
  }
}

now, if you want to sleep for 1 second, just use:

sleep(1000);

example: http://jsfiddle.net/HrJku/1/

please note that this code will keep your script busy for n milliseconds. This will not only stop execution of Javascript on your page, but depending on the browser implementation, may possibly make the page completely unresponsive, and possibly make the entire browser unresponsive. In other words this is almost always the wrong thing to do.

Monitor network activity in Android Phones

TCPDUMP is one of my favourite tools for analyzing network, but if you find difficult to cross-compile tcpdump for android, I'd recomend you to use some applications from the market.

These are the applications I was talking about:

  • Shark: Is small version of wireshark for Android phones). This program will create a *.pcap and you can read the file on PC with wireshark.
  • Shark Reader : This program allows you to read the *.pcap directly in your Android phone.

Shark app works with rooted devices, so if you want to install it, be sure that you have your device already rooted.

Good luck ;)

Sort ObservableCollection<string> through C#

This extension method eliminates the need to sort the entire list.

Instead, it inserts each new item in place. So the list is always remains sorted.

It turns out that this method just works when a lot of the other methods fail due to missing notifications when the collection changes. And it is rather fast.

The code below should be bulletproof; it has been extensively tested in a large-scale production environment.

To use:

// Call on dispatcher.
ObservableCollection<MyClass> collectionView = new ObservableCollection<MyClass>();
var p1 = new MyClass() { Key = "A" }
var p2 = new MyClass() { Key = "Z" }
var p3 = new MyClass() { Key = "D" }
collectionView.InsertInPlace(p1, o => o.Key);
collectionView.InsertInPlace(p2, o => o.Key);
collectionView.InsertInPlace(p3, o => o.Key);
// The list will always remain ordered on the screen, e.g. "A, D, Z" .
// Insertion speed is Log(N) as it uses a binary search.

And the extension method:

/// <summary>
/// Inserts an item into a list in the correct place, based on the provided key and key comparer. Use like OrderBy(o => o.PropertyWithKey).
/// </summary>
public static void InsertInPlace<TItem, TKey>(this ObservableCollection<TItem> collection, TItem itemToAdd, Func<TItem, TKey> keyGetter)
{
    int index = collection.ToList().BinarySearch(keyGetter(itemToAdd), Comparer<TKey>.Default, keyGetter);
    collection.Insert(index, itemToAdd);
}

And the binary search extension method:

/// <summary>
/// Binary search.
/// </summary>
/// <returns>Index of item in collection.</returns> 
/// <notes>This version tops out at approximately 25% faster than the equivalent recursive version. This 25% speedup is for list
/// lengths more of than 1000 items, with less performance advantage for smaller lists.</notes>
public static int BinarySearch<TItem, TKey>(this IList<TItem> collection, TKey keyToFind, IComparer<TKey> comparer, Func<TItem, TKey> keyGetter)
{
    if (collection == null)
    {
        throw new ArgumentNullException(nameof(collection));
    }

    int lower = 0;
    int upper = collection.Count - 1;

    while (lower <= upper)
    {
        int middle = lower + (upper - lower) / 2;
        int comparisonResult = comparer.Compare(keyToFind, keyGetter.Invoke(collection[middle]));
        if (comparisonResult == 0)
        {
            return middle;
        }
        else if (comparisonResult < 0)
        {
            upper = middle - 1;
        }
        else
        {
            lower = middle + 1;
        }
    }

    // If we cannot find the item, return the item below it, so the new item will be inserted next.
    return lower;
}

What's the best way to generate a UML diagram from Python source code?

Sparx's Enterprise Architect performs round-tripping of Python source. They have a free time-limited trial edition.

Code for a simple JavaScript countdown timer?

You can do as follows with pure JS. You just need to provide the function with the number of seconds and it will do the rest.

_x000D_
_x000D_
var insertZero = n => n < 10 ? "0"+n : ""+n,_x000D_
   displayTime = n => n ? time.textContent = insertZero(~~(n/3600)%3600) + ":" +_x000D_
                                             insertZero(~~(n/60)%60) + ":" +_x000D_
                                             insertZero(n%60)_x000D_
                        : time.textContent = "IGNITION..!",_x000D_
 countDownFrom = n => (displayTime(n), setTimeout(_ => n ? sid = countDownFrom(--n)_x000D_
                                                         : displayTime(n), 1000)),_x000D_
           sid;_x000D_
countDownFrom(3610);_x000D_
setTimeout(_ => clearTimeout(sid),20005);
_x000D_
<div id="time"></div>
_x000D_
_x000D_
_x000D_

Submit HTML form, perform javascript function (alert then redirect)

You need to prevent the default behaviour. You can either use e.preventDefault() or return false; In this case, the best thing is, you can use return false; here:

<form onsubmit="completeAndRedirect(); return false;">

C# Reflection: How to get class reference from string?

We can use

Type.GetType()

to get class name and can also create object of it using Activator.CreateInstance(type);

using System;
using System.Reflection;

namespace MyApplication
{
    class Application
    {
        static void Main()
        {
            Type type = Type.GetType("MyApplication.Action");
            if (type == null)
            {
                throw new Exception("Type not found.");
            }
            var instance = Activator.CreateInstance(type);
            //or
            var newClass = System.Reflection.Assembly.GetAssembly(type).CreateInstance("MyApplication.Action");
        }
    }

    public class Action
    {
        public string key { get; set; }
        public string Value { get; set; }
    }
}

Move_uploaded_file() function is not working

This answer is late but it might help someone like it helped me

Just ensure you have given the user permission for the destination file

sudo chown -R www-data:www-data /Users/George/Desktop/uploads/

How to capture the android device screen content?

Framebuffer seems the way to go, it will not always contain 2+ frames like mentioned by Ryan Conrad. In my case it contained only one. I guess it depends on the frame/display size.

I tried to read the framebuffer continuously but it seems to return for a fixed amount of bytes read. In my case that is (3 410 432) bytes, which is enough to store a display frame of 854*480 RGBA (3 279 360 bytes). Yes, the frame in binary outputed from fb0 is RGBA in my device. This will most likely depend from device to device. This will be important for you to decode it =)

In my device /dev/graphics/fb0 permissions are so that only root and users from group graphics can read the fb0. graphics is a restricted group so you will probably only access fb0 with a rooted phone using su command.

Android apps have the user id (uid) app_## and group id (guid) app_## .

adb shell has uid shell and guid shell, which has much more permissions than an app. You can actually check those permissions at /system/permissions/platform.xml

This means you will be able to read fb0 in the adb shell without root but you will not read it within the app without root.

Also, giving READ_FRAME_BUFFER and/or ACCESS_SURFACE_FLINGER permissions on AndroidManifest.xml will do nothing for a regular app because these will only work for 'signature' apps.

Adding a new line/break tag in XML

You don't need anything fancy: the following contains a new line (two, actually):

<summary>Tootsie roll tiramisu macaroon wafer carrot cake.       
         Danish topping sugar plum tart bonbon caramels cake.
</summary>

The question is, why isn't this newline having the desired effect: and that's a question about what the recipient of the XML is actually doing with it. For example, if the recipient is translating it to HTML and the HTML is being displayed in the browser, then the newline will be converted to a space by the browser. You need to tell us something about the processing pipeline.

Convert line endings

Some options:

Using tr

tr -d '\15\32' < windows.txt > unix.txt

OR

tr -d '\r' < windows.txt > unix.txt 

Using perl

perl -p -e 's/\r$//' < windows.txt > unix.txt

Using sed

sed 's/^M$//' windows.txt > unix.txt

OR

sed 's/\r$//' windows.txt > unix.txt

To obtain ^M, you have to type CTRL-V and then CTRL-M.

How to set seekbar min and max value

Seek Bar has methods for setting max values but not for setting min value here i write a code for setting minimum seek bar value when we add this code then your seek bar values not less then mim value try this its work fine for me

/* This methods call after seek bar value change */

            public void onProgressChanged(SeekBar seekBar, int progress,
                boolean fromUser) {
            /* Check the current seekbar value is greather than min value*/
            if (progress < MIN_VALUE) {
                /* if seek bar value is lesser than min value then set min value to seek bar */
                seekBar.setProgress(MIN_VALUE);
            }

        }

Bootstrap button - remove outline on Chrome OS X

If someone is using bootstrap sass note the code is on the _reboot.scss file like this:

button:focus {
  outline: 1px dotted;
  outline: 5px auto -webkit-focus-ring-color;
}

So if you want to keep the _reboot file I guess feel free to override with plain css instead of trying to look for a variable to change.

Reading file using fscanf() in C

In your code:

while(fscanf(fp,"%s %c",item,&status) == 1)  

why 1 and not 2? The scanf functions return the number of objects read.

python: get directory two levels up

More cross-platform implementation will be:

import pathlib
two_up = (pathlib.Path(__file__) / ".." / "..").resolve()

Using parent is not supported on Windows. Also need to add .resolve(), to:

Make the path absolute, resolving all symlinks on the way and also normalizing it (for example turning slashes into backslashes under Windows)

How to mount a single file in a volume

I had the same issue, docker-compose was creating a directory instead of a file, then crashing mid-way.

what i did :

  1. run the container without mapping the file

  2. copy the config file to the host location :

    docker cp containername:/var/www/html/config.php ./config.php

  3. remove the container (docker-compose down)

  4. put the mapping back and remount up the container

docker compose will find the config file, and will map that instead of trying to create a directory.

Using an array as needles in strpos

The question, is the provided example just an "example" or exact what you looking for? There are many mixed answers here, and I dont understand the complexibility of the accepted one.

To find out if ANY content of the array of needles exists in the string, and quickly return true or false:

$string = 'abcdefg';

if(str_replace(array('a', 'c', 'd'), '', $string) != $string){
    echo 'at least one of the needles where found';
};

If, so, please give @Leon credit for that.

To find out if ALL values of the array of needles exists in the string, as in this case, all three 'a', 'b' and 'c' MUST be present, like you mention as your "for example"

echo 'All the letters are found in the string!';

Many answers here is out of that context, but I doubt that the intension of the question as you marked as resolved. E.g. The accepted answer is a needle of

$array  = array('burger', 'melon', 'cheese', 'milk');

What if all those words MUST be found in the string?

Then you try out some "not accepted answers" on this page.

WebAPI to Return XML

Here's another way to be compatible with an IHttpActionResult return type. In this case I am asking it to use the XML Serializer(optional) instead of Data Contract serializer, I'm using return ResponseMessage( so that I get a return compatible with IHttpActionResult:

return ResponseMessage(new HttpResponseMessage(HttpStatusCode.OK)
       {
           Content = new ObjectContent<SomeType>(objectToSerialize, 
              new System.Net.Http.Formatting.XmlMediaTypeFormatter { 
                  UseXmlSerializer = true 
              })
       });

Best way to remove an event handler in jQuery?

Best way to remove inline onclick event is $(element).prop('onclick', null);

Clear variable in python

var = None "clears the value", setting the value of the variable to "null" like value of "None", however the pointer to the variable remains.

del var removes the definition for the variable totally.

In case you want to use the variable later, e.g. set a new value for it, i.e. retain the variable, None would be better.

What is the standard Python docstring format?

PEP-8 is the official python coding standard. It contains a section on docstrings, which refers to PEP-257 -- a complete specification for docstrings.

SQL Query to find missing rows between two related tables

SELECT A.ABC_ID, A.VAL FROM A WHERE NOT EXISTS 
   (SELECT * FROM B WHERE B.ABC_ID = A.ABC_ID AND B.VAL = A.VAL)

or

SELECT A.ABC_ID, A.VAL FROM A WHERE VAL NOT IN 
    (SELECT VAL FROM B WHERE B.ABC_ID = A.ABC_ID)

or

SELECT A.ABC_ID, A.VAL LEFT OUTER JOIN B 
    ON A.ABC_ID = B.ABC_ID AND A.VAL = B.VAL FROM A WHERE B.VAL IS NULL

Please note that these queries do not require that ABC_ID be in table B at all. I think that does what you want.

utf-8 special characters not displaying

The problem is because your file are not with the same encoding. First run the following command in all your files:

file -i filename.* 

In order to fix the problem you have to change all your files to uft-8. You can do it with the command iconv:

iconv -f fromcode -t tocode filename > newfilename

Example:

iconv -f iso-8859-1 -t utf-8 index.html > fixed/index.html

After this you can run file -i fixedx/index.html and you will see that your file is now in uft-8

How to show all of columns name on pandas dataframe?

Not a conventional answer, but I guess you could transpose the dataframe to look at the rows instead of the columns. I use this because I find looking at rows more 'intuitional' than looking at columns:

data_all2.T

This should let you view all the rows. This action is not permanent, it just lets you view the transposed version of the dataframe.

If the rows are still truncated, just use print(data_all2.T) to view everything.

get the selected index value of <select> tag in php

As you said..

$Gender  = isset($_POST["gender"]); ' it returns a empty string 

because, you haven't mention method type either use POST or GET, by default it will use GET method. On the other side, you are trying to retrieve your value by using POST method, but in the form you haven't mentioned POST method. Which means miss-match method will result for empty.

Try this code..

<form name="signup_form"  action="./signup.php" onsubmit="return validateForm()"   method="post">
<table> 
  <tr> <td> First Name    </td><td> <input type="text" name="fname" size=10/></td></tr>
  <tr> <td> Last Name     </td><td> <input type="text" name="lname" size=10/></td></tr>
  <tr> <td> Your Email    </td><td> <input type="text" name="email" size=10/></td></tr>
  <tr> <td> Re-type Email </td><td> <input type="text" name="remail"size=10/></td></tr>
  <tr> <td> Password      </td><td> <input type="password" name="paswod" size=10/> </td></tr>
  <tr> <td> Gender        </td><td> <select name="gender">
  <option value="select">                Select </option>    
  <option value="male">   Male   </option>
  <option value="female"> Female </option></select></td></tr> 
  <tr> <td> <input type="submit" value="Sign up" id="signup"/> </td> </tr>
 </table>
 </form>

and on signup page

$Gender  = $_POST["gender"];

i'm sure.. now, you will get the value..

Set focus to field in dynamically loaded DIV

$("#header").attr('tabindex', -1).focus();

Web API optional parameters

Sku is an int, can't be defaulted to string "sku". Please check Optional URI Parameters and Default Values

Storing and displaying unicode string (??????) using PHP and MySQL

For those who are looking for PHP ( >5.3.5 ) PDO statement, we can set charset as per below:

$dbh = new PDO('mysql:host=localhost;dbname=testdb;charset=utf8', 'username', 'password');

Binding Combobox Using Dictionary as the Datasource

I know this is a pretty old topic, but I also had a same problem.

My solution:

how we fill the combobox:

foreach (KeyValuePair<int, string> item in listRegion)
{
    combo.Items.Add(item.Value);
    combo.ValueMember = item.Value.ToString();
    combo.DisplayMember = item.Key.ToString();
    combo.SelectedIndex = 0;
}

and that's how we get inside:

 MessageBox.Show(combo_region.DisplayMember.ToString());

I hope it help someone

Capturing multiple line output into a Bash variable

Actually, RESULT contains what you want — to demonstrate:

echo "$RESULT"

What you show is what you get from:

echo $RESULT

As noted in the comments, the difference is that (1) the double-quoted version of the variable (echo "$RESULT") preserves internal spacing of the value exactly as it is represented in the variable — newlines, tabs, multiple blanks and all — whereas (2) the unquoted version (echo $RESULT) replaces each sequence of one or more blanks, tabs and newlines with a single space. Thus (1) preserves the shape of the input variable, whereas (2) creates a potentially very long single line of output with 'words' separated by single spaces (where a 'word' is a sequence of non-whitespace characters; there needn't be any alphanumerics in any of the words).

Deserializing JSON to .NET object using Newtonsoft (or LINQ to JSON maybe?)

Fairly late to this party, but I came across this issue myself today at work. Here is how I solved the issue.

I was accessing a 3rd party API to retrieve a list of books. The object returned a massive JSON object containing roughly 20+ fields, of which I only needed the ID as a List string object. I used linq on the dynamic object to retrieve the specific field I needed and then inserted it into my List string object.

dynamic content = JsonConvert.DeserializeObject(requestContent);
var contentCodes = ((IEnumerable<dynamic>)content).Where(p => p._id != null).Select(p=>p._id).ToList();

List<string> codes = new List<string>();

foreach (var code in contentCodes)
{
    codes.Add(code?.ToString());
}

Seconds CountDown Timer

enter image description here .

Usage:

CountDownTimer timer = new CountDownTimer();


//set to 30 mins
timer.SetTime(30,0);     

timer.Start();

//update label text
timer.TimeChanged += () => Label1.Text = timer.TimeLeftMsStr; 

// show messageBox on timer = 00:00.000
timer.CountDownFinished += () => MessageBox.Show("Timer finished the work!"); 

//timer step. By default is 1 second
timer.StepMs = 77; // for nice milliseconds time switch

and don't forget to Dispose(); when timer is useless for you;

Source code:

using System;
using System.Diagnostics;
using System.Windows.Forms;

public class CountDownTimer : IDisposable
{
    public Stopwatch _stpWatch = new Stopwatch();

    public Action TimeChanged;
    public Action CountDownFinished;

    public bool IsRunnign => timer.Enabled;

    public int StepMs
    {
        get => timer.Interval;
        set => timer.Interval = value;
    }

    private Timer timer = new Timer();

    private TimeSpan _max = TimeSpan.FromMilliseconds(30000);

    public TimeSpan TimeLeft => (_max.TotalMilliseconds - _stpWatch.ElapsedMilliseconds) > 0 ? TimeSpan.FromMilliseconds(_max.TotalMilliseconds - _stpWatch.ElapsedMilliseconds) : TimeSpan.FromMilliseconds(0);

    private bool _mustStop => (_max.TotalMilliseconds - _stpWatch.ElapsedMilliseconds) < 0;

    public string TimeLeftStr => TimeLeft.ToString(@"\mm\:ss");

    public string TimeLeftMsStr => TimeLeft.ToString(@"mm\:ss\.fff");

    private void TimerTick(object sender, EventArgs e)
    {
        TimeChanged?.Invoke();

        if (_mustStop)
        {
            CountDownFinished?.Invoke();
            _stpWatch.Stop();
            timer.Enabled = false;
        }
    }

    public CountDownTimer(int min, int sec)
    {
        SetTime(min, sec);
        Init();
    }

    public CountDownTimer(TimeSpan ts)
    {
        SetTime(ts);
        Init();
    }

    public CountDownTimer()
    {
        Init();
    }

    private void Init()
    {
        StepMs = 1000;
        timer.Tick += new EventHandler(TimerTick);
    }

    public void SetTime(TimeSpan ts)
    {
        _max = ts;
        TimeChanged?.Invoke();
    }

    public void SetTime(int min, int sec = 0) => SetTime(TimeSpan.FromSeconds(min * 60 + sec));

    public void Start() {
        timer.Start();
        _stpWatch.Start();
    }

    public void Pause()
    {
        timer.Stop();
        _stpWatch.Stop();
    }

    public void Stop()
    {
        Reset();
        Pause();
    }

    public void Reset()
    {
        _stpWatch.Reset();
    }

    public void Restart()
    {
        _stpWatch.Reset();
        timer.Start();
    }

    public void Dispose() => timer.Dispose();
}

(updated 6.6.2020, because of problems with time calculation)

How to process a file in PowerShell line-by-line as a stream

System.IO.File.ReadLines() is perfect for this scenario. It returns all the lines of a file, but lets you begin iterating over the lines immediately which means it does not have to store the entire contents in memory.

Requires .NET 4.0 or higher.

foreach ($line in [System.IO.File]::ReadLines($filename)) {
    # do something with $line
}

http://msdn.microsoft.com/en-us/library/dd383503.aspx

git add remote branch

You can check if you got your remote setup right and have the proper permissions with

git ls-remote origin

if you called your remote "origin". If you get an error you probably don't have your security set up correctly such as uploading your public key to github for example. If things are setup correctly, you will get a list of the remote references. Now

git fetch origin

will work barring any other issues like an unplugged network cable.

Once you have that done, you can get any branch you want that the above command listed with

git checkout some-branch

this will create a local branch of the same name as the remote branch and check it out.

SQLAlchemy: how to filter date field?

if you want to get the whole period:

    from sqlalchemy import and_, func

    query = DBSession.query(User).filter(and_(func.date(User.birthday) >= '1985-01-17'),\
                                              func.date(User.birthday) <= '1988-01-17'))

That means range: 1985-01-17 00:00 - 1988-01-17 23:59

How to get the directory of the currently running file?

EDIT: As of Go 1.8 (Released February 2017) the recommended way of doing this is with os.Executable:

func Executable() (string, error)

Executable returns the path name for the executable that started the current process. There is no guarantee that the path is still pointing to the correct executable. If a symlink was used to start the process, depending on the operating system, the result might be the symlink or the path it pointed to. If a stable result is needed, path/filepath.EvalSymlinks might help.

To get just the directory of the executable you can use path/filepath.Dir.

Example:

package main

import (
    "fmt"
    "os"
    "path/filepath"
)

func main() {
    ex, err := os.Executable()
    if err != nil {
        panic(err)
    }
    exPath := filepath.Dir(ex)
    fmt.Println(exPath)
}

OLD ANSWER:

You should be able to use os.Getwd

func Getwd() (pwd string, err error)

Getwd returns a rooted path name corresponding to the current directory. If the current directory can be reached via multiple paths (due to symbolic links), Getwd may return any one of them.

For example:

package main

import (
    "fmt"
    "os"
)

func main() {
    pwd, err := os.Getwd()
    if err != nil {
        fmt.Println(err)
        os.Exit(1)
    }
    fmt.Println(pwd)
}

Prevent content from expanding grid items

The previous answer is pretty good, but I also wanted to mention that there is a fixed layout equivalent for grids, you just need to write minmax(0, 1fr) instead of 1fr as your track size.

How to get visitor's location (i.e. country) using geolocation?

You can use my service, http://ipinfo.io, for this. It will give you the client IP, hostname, geolocation information (city, region, country, area code, zip code etc) and network owner. Here's a simple example that logs the city and country:

$.get("https://ipinfo.io", function(response) {
    console.log(response.city, response.country);
}, "jsonp");

Here's a more detailed JSFiddle example that also prints out the full response information, so you can see all of the available details: http://jsfiddle.net/zK5FN/2/

The location will generally be less accurate than the native geolocation details, but it doesn't require any user permission.

Differences between key, superkey, minimal superkey, candidate key and primary key

Super Key : Super key is a set of one or more attributes whose values identify tuple in the relation uniquely.

Candidate Key : Candidate key can be defined as a minimal subset of super key. In some cases , candidate key can not alone since there is alone one attribute is the minimal subset. Example,

Employee(id, ssn, name, addrress)

Here Candidate key is (id, ssn) because we can easily identify the tuple using either id or ssn . Althrough, minimal subset of super key is either id or ssn. but both of them can be considered as candidate key.

Primary Key : Primary key is a one of the candidate key.

Example : Student(Id, Name, Dept, Result)

Here

Super Key : {Id, Id+Name, Id+Name+Dept} because super key is set of attributes .

Candidate Key : Id because Id alone is the minimal subset of super key.

Primary Key : Id because Id is one of the candidate key

Is there a way to make text unselectable on an HTML page?

Try this:

<div onselectstart="return false">some stuff</div>

Simple, but effective... works in current versions of all major browsers.

Stop on first error

Maybe you want set -e:

www.davidpashley.com/articles/writing-robust-shell-scripts.html#id2382181:

This tells bash that it should exit the script if any statement returns a non-true return value. The benefit of using -e is that it prevents errors snowballing into serious issues when they could have been caught earlier. Again, for readability you may want to use set -o errexit.

How to round each item in a list of floats to 2 decimal places?

"%.2f" does not return a clean float. It returns a string representing this float with two decimals.

my_list = [0.30000000000000004, 0.5, 0.20000000000000001]
my_formatted_list = [ '%.2f' % elem for elem in my_list ]

returns:

['0.30', '0.50', '0.20']

Also, don't call your variable list. This is a reserved word for list creation. Use some other name, for example my_list.

If you want to obtain [0.30, 0.5, 0.20] (or at least the floats that are the closest possible), you can try this:

my_rounded_list = [ round(elem, 2) for elem in my_list ]

returns:

[0.29999999999999999, 0.5, 0.20000000000000001]

Truncate with condition

You can simply export the table with a query clause using datapump and import it back with table_exists_action=replace clause. Its will drop and recreate your table and take very less time. Please read about it before implementing.

Eclipse - Failed to create the java virtual machine

It works for me after removing -XX:+UseParallelOldGC option from file.

How do I run a program with a different working directory from current, from Linux shell?

Just change the last "&&" into ";" and it will cd back no matter if the command fails or succeeds:

cd SOME_PATH && run_some_command ; cd -

Windows Batch Files: if else

Surround your %1 with something.

Eg:

if not "%1" == ""

Another one I've seen fairly often:

if not {%1} == {}

And so on...

The problem, as you can likely guess, is that the %1 is literally replaced with emptiness. It is not 'an empty string' it is actually a blank spot in your source file at that point.

Then after the replacement, the interpreter tries to parse the if statement and gets confused.

Laravel - Eloquent "Has", "With", "WhereHas" - What do they mean?

Document has already explain the usage. So I am using SQL to explain these methods

Example:


Assuming there is an Order (orders) has many OrderItem (order_items).

And you have already build the relationship between them.

// App\Models\Order:
public function orderItems() {
    return $this->hasMany('App\Models\OrderItem', 'order_id', 'id');
}

These three methods are all based on a relationship.

With


Result: with() return the model object and its related results.

Advantage: It is eager-loading which can prevent the N+1 problem.

When you are using the following Eloquent Builder:

Order::with('orderItems')->get();

Laravel change this code to only two SQL:

// get all orders:
SELECT * FROM orders; 

// get the order_items based on the orders' id above
SELECT * FROM order_items WHERE order_items.order_id IN (1,2,3,4...);

And then laravel merge the results of the second SQL as different from the results of the first SQL by foreign key. At last return the collection results.

So if you selected columns without the foreign_key in closure, the relationship result will be empty:

Order::with(['orderItems' => function($query) { 
           // $query->sum('quantity');
           $query->select('quantity'); // without `order_id`
       }
])->get();

#=> result:
[{  id: 1,
    code: '00001',
    orderItems: [],    // <== is empty
  },{
    id: 2,
    code: '00002',
    orderItems: [],    // <== is empty
  }...
}]

Has


Has will return the model's object that its relationship is not empty.

Order::has('orderItems')->get();

Laravel change this code to one SQL:

select * from `orders` where exists (
    select * from `order_items` where `order`.`id` = `order_item`.`order_id`
)

whereHas


whereHas and orWhereHas methods to put where conditions on your has queries. These methods allow you to add customized constraints to a relationship constraint.

Order::whereHas('orderItems', function($query) {
   $query->where('status', 1);
})->get();

Laravel change this code to one SQL:

select * from `orders` where exists (
    select * 
    from `order_items` 
    where `orders`.`id` = `order_items`.`order_id` and `status` = 1
)

Save child objects automatically using JPA Hibernate

Here are the ways to assign parent object in child object of Bi-directional relations ?

Suppose you have a relation say One-To-Many,then for each parent object,a set of child object exists. In bi-directional relations,each child object will have reference to its parent.

eg : Each Department will have list of Employees and each Employee is part of some department.This is called Bi directional relations.

To achieve this, one way is to assign parent in child object while persisting parent object

Parent parent = new Parent();
...
Child c1 = new Child();
...
c1.setParent(parent);

List<Child> children = new ArrayList<Child>();
children.add(c1);
parent.setChilds(children);

session.save(parent);

Other way is, you can do using hibernate Intercepter,this way helps you not to write above code for all models.

Hibernate interceptor provide apis to do your own work before perform any DB operation.Likewise onSave of object, we can assign parent object in child objects using reflection.

public class CustomEntityInterceptor extends EmptyInterceptor {

    @Override
    public boolean onSave(
            final Object entity, final Serializable id, final Object[] state, final String[] propertyNames,
            final Type[] types) {
        if (types != null) {
            for (int i = 0; i < types.length; i++) {
                if (types[i].isCollectionType()) {
                    String propertyName = propertyNames[i];
                    propertyName = propertyName.substring(0, 1).toUpperCase() + propertyName.substring(1);
                    try {
                        Method method = entity.getClass().getMethod("get" + propertyName);
                        List<Object> objectList = (List<Object>) method.invoke(entity);

                        if (objectList != null) {
                            for (Object object : objectList) {
                                String entityName = entity.getClass().getSimpleName();
                                Method eachMethod = object.getClass().getMethod("set" + entityName, entity.getClass());
                                eachMethod.invoke(object, entity);
                            }
                        }

                    } catch (NoSuchMethodException | InvocationTargetException | IllegalAccessException e) {
                        throw new RuntimeException(e);
                    }
                }
            }
        }
        return true;
    }

}

And you can register Intercepter to configuration as

new Configuration().setInterceptor( new CustomEntityInterceptor() );

React component not re-rendering on state change

That's because the response from chrome.runtime.sendMessage is asynchronous; here's the order of operations:

var newDeals = [];

// (1) first chrome.runtime.sendMessage is called, and *registers a callback*
// so that when the data comes back *in the future*
// the function will be called
chrome.runtime.sendMessage({...}, function(deals) {
  // (3) sometime in the future, this function runs,
  // but it's too late
  newDeals = deals;
});

// (2) this is called immediately, `newDeals` is an empty array
this.setState({ deals: newDeals });

When you pause the script with the debugger, you're giving the extension time to call the callback; by the time you continue, the data has arrived and it appears to work.

To fix, you want to do the setState call after the data comes back from the Chrome extension:

var newDeals = [];

// (1) first chrome.runtime.sendMessage is called, and *registers a callback*
// so that when the data comes back *in the future*
// the function will be called
chrome.runtime.sendMessage({...}, function(deals) {
  // (2) sometime in the future, this function runs
  newDeals = deals;

  // (3) now you can call `setState` with the data
  this.setState({ deals: newDeals });
}.bind(this)); // Don't forget to bind(this) (or use an arrow function)

[Edit]

If this doesn't work for you, check out the other answers on this question, which explain other reasons your component might not be updating.

Communication between multiple docker-compose projects

Another option is just running up the first module with the 'docker-compose' check the ip related with the module, and connect the second module with the previous net like external, and pointing the internal ip

example app1 - new-network created in the service lines, mark as external: true at the bottom app2 - indicate the "new-network" created by app1 when goes up, mark as external: true at the bottom, and set in the config to connect, the ip that app1 have in this net.

With this, you should be able to talk with each other

*this way is just for local-test focus, in order to don't do an over complex configuration ** I know is very 'patch way' but works for me and I think is so simple some other can take advantage of this

Create a directory if it does not exist and then create the files in that directory as well

Using java.nio.Path it would be quite simple -

public static Path createFileWithDir(String directory, String filename) {
        File dir = new File(directory);
        if (!dir.exists()) dir.mkdirs();
        return Paths.get(directory + File.separatorChar + filename);
    }

java.net.UnknownHostException: Invalid hostname for server: local

What the exception is really saying is that there is no known server with the name "local". My guess is that you're trying to connect to your local computer. Try with the hostname "localhost" instead, or perhaps 127.0.0.1 or ::1 (the last one is IPv6).

From the javadocs:

Thrown to indicate that the IP address of a host could not be determined.

127.0.0.1or ::1 or "localhost" should always be the loopback interface, so if that doesn't work I'd be really surprised.

If there really is a server called "local" on your network - examine your DNS settings or add it to your hosts file.

Working with time DURATION, not time of day

I don't know how to make the chart label the axis in the format "X1 min : X2 sec", but here's another way to get durations, in the format of minutes with decimals representing seconds (.5 = 30 sec, .25 = 15 sec, etc.)

Suppose in column A you have your time data, for example in cell A1 you have 12:03:06, which your 3min 6sec data misinterpreted as 3:06 past midnight, and column B is free.

In cell B1 enter this formula: =MINUTE(A1) + SECOND(A1)/60 and hit enter/return. Grab the lower right corner of cell B2 and drag as far down as the A column goes to apply the formula to all data in col A.

Last step, be sure to highlight all of column B and set it to Number format (the application of the formula may have automatically set format to Time).

.htaccess or .htpasswd equivalent on IIS?

I've never used it but Trilead, a free ISAPI filter which enables .htaccess based control, looks like what you want.

Javascript loading CSV file into an array

You can't use AJAX to fetch files from the user machine. This is absolutely the wrong way to go about it.

Use the FileReader API:

<input type="file" id="file input">

js:

console.log(document.getElementById("file input").files); // list of File objects

var file = document.getElementById("file input").files[0];
var reader = new FileReader();
content = reader.readAsText(file);
console.log(content);

Then parse content as CSV. Keep in mind that your parser currently does not deal with escaped values in CSV like: value1,value2,"value 3","value ""4"""

How can I store JavaScript variable output into a PHP variable?

in your view:

  <?php $value = '<p id="course_id"></p>';?>

javascript code:

  var course = document.getElementById("courses").value;
  
 document.getElementById("course_id").innerHTML = course;

React - How to get parameter value from query string?

this.props.params.your_param_name will work.

This is the way to get the params from your query string.
Please do console.log(this.props); to explore all the possibilities.

Combining Two Images with OpenCV

You can also use OpenCV's inbuilt functions cv2.hconcat and cv2.vconcat which like their names suggest are used to join images horizontally and vertically respectively.

import cv2

img1 = cv2.imread('opencv/lena.jpg')
img2 = cv2.imread('opencv/baboon.jpg')

v_img = cv2.vconcat([img1, img2])
h_img = cv2.hconcat([img1, img2])

cv2.imshow('Horizontal', h_img)
cv2.imshow('Vertical', v_img)
cv2.waitKey(0)
cv2.destroyAllWindows()

Horizontal Concatenation

Horizontal

Vertical Concatenation

Vertical

Styling a input type=number

Crazy idea...

You could play around with some pseudo elements, and create up/down arrows of css content hex codes. The only challange will be to precise the positioning of the arrow, but it may work:

_x000D_
_x000D_
input[type="number"] {_x000D_
    height: 100px;_x000D_
}_x000D_
_x000D_
.number-wrapper {_x000D_
    position: relative;_x000D_
}_x000D_
_x000D_
.number-wrapper:hover:after {_x000D_
    content: "\25B2";_x000D_
    position: absolute;_x000D_
    color: blue;_x000D_
    left: 100%;_x000D_
    margin-left: -17px;_x000D_
    margin-top: 12%;_x000D_
    font-size: 11px;_x000D_
}_x000D_
_x000D_
.number-wrapper:hover:before {_x000D_
    content: "\25BC";_x000D_
    position: absolute;_x000D_
    color: blue;_x000D_
    left: 100%;_x000D_
    bottom: 0;_x000D_
    margin-left: -17px;_x000D_
    margin-bottom: -14%;_x000D_
    font-size: 11px;_x000D_
}
_x000D_
<span class='number-wrapper'>_x000D_
    <input type="number" />_x000D_
</span>
_x000D_
_x000D_
_x000D_

find difference between two text files with one item per line

grep -Fxvf file1 file2

What the flags mean:

-F, --fixed-strings
              Interpret PATTERN as a list of fixed strings, separated by newlines, any of which is to be matched.    
-x, --line-regexp
              Select only those matches that exactly match the whole line.
-v, --invert-match
              Invert the sense of matching, to select non-matching lines.
-f FILE, --file=FILE
              Obtain patterns from FILE, one per line.  The empty file contains zero patterns, and therefore matches nothing.

How do you run CMD.exe under the Local System Account?

Using task scheduler, schedule a run of CMDKEY running under SYSTEM with the appropriate arguments of /add: /user: and /pass:

No need to install anything.

Getting all request parameters in Symfony 2

Since you are in a controller, the action method is given a Request parameter.

You can access all POST data with $request->request->all();. This returns a key-value pair array.

When using GET requests you access data using $request->query->all();

Basic CSS - how to overlay a DIV with semi-transparent DIV on top

For a div-Element you could just set the opacity via a class to enable or disable the effect.

.mute-all {
   opacity: 0.4;
}

How to update the constant height constraint of a UIView programmatically?

If you have a view with multiple constrains, a much easier way without having to create multiple outlets would be:

In interface builder, give each constraint you wish to modify an identifier:

enter image description here

Then in code you can modify multiple constraints like so:

for constraint in self.view.constraints {
    if constraint.identifier == "myConstraint" {
       constraint.constant = 50
    }
}
myView.layoutIfNeeded()

You can give multiple constrains the same identifier thus allowing you to group together constrains and modify all at once.

MySQL order by before group by

First, don't use * in select, affects their performance and hinder the use of the group by and order by. Try this query:

SELECT wp_posts.post_author, wp_posts.post_date as pdate FROM wp_posts
WHERE wp_posts.post_status='publish'
AND wp_posts.post_type='post'
GROUP BY wp_posts.post_author           
ORDER BY pdate DESC

When you don't specifies the table in ORDER BY, just the alias, they will order the result of the select.

What's the u prefix in a Python string?

It's Unicode.

Just put the variable between str(), and it will work fine.

But in case you have two lists like the following:

a = ['co32','co36']
b = [u'co32',u'co36']

If you check set(a)==set(b), it will come as False, but if you do as follows:

b = str(b)
set(a)==set(b)

Now, the result will be True.

Parse json string to find and element (key / value)

Use a JSON parser, like JSON.NET

string json = "{ \"Atlantic/Canary\": \"GMT Standard Time\", \"Europe/Lisbon\": \"GMT Standard Time\", \"Antarctica/Mawson\": \"West Asia Standard Time\", \"Etc/GMT+3\": \"SA Eastern Standard Time\", \"Etc/GMT+2\": \"UTC-02\", \"Etc/GMT+1\": \"Cape Verde Standard Time\", \"Etc/GMT+7\": \"US Mountain Standard Time\", \"Etc/GMT+6\": \"Central America Standard Time\", \"Etc/GMT+5\": \"SA Pacific Standard Time\", \"Etc/GMT+4\": \"SA Western Standard Time\", \"Pacific/Wallis\": \"UTC+12\", \"Europe/Skopje\": \"Central European Standard Time\", \"America/Coral_Harbour\": \"SA Pacific Standard Time\", \"Asia/Dhaka\": \"Bangladesh Standard Time\", \"America/St_Lucia\": \"SA Western Standard Time\", \"Asia/Kashgar\": \"China Standard Time\", \"America/Phoenix\": \"US Mountain Standard Time\", \"Asia/Kuwait\": \"Arab Standard Time\" }";
var data = (JObject)JsonConvert.DeserializeObject(json);
string timeZone = data["Atlantic/Canary"].Value<string>();

List all employee's names and their managers by manager name using an inner join

select e.ename as Employee, m.ename as Manager
from emp e, emp m
where e.mgr = m.empno

If you want to get the result for all the records (irrespective of whether they report to anyone or not), append (+) on the second table's name

select e.ename as Employee, m.ename as Manager
from emp e, emp m
where e.mgr = m.empno(+)

ld.exe: cannot open output file ... : Permission denied

i experienced a similar issue. Bitdefender automatically quarantined each exe-file i created by MinGW g++. Instead of the full exe-file i found a file with a weird extension 'qzquar' testAutoPtr1.exe.48352.gzquar

When i opened quarantined items in Bitdefender i found my exe-file quarantined there.

pycharm running way slow

Regarding the freezing issue, we found this occurred when processing CSV files with at least one extremely long line.

To reproduce:

[print(x) for x in (['A' * 54790] + (['a' * 1421] * 10))]

However, it appears to have been fixed in PyCharm 4.5.4, so if you experience this, try updating your PyCharm.

Centering the pagination in bootstrap

To centered the pagination in BS4, should add justify-content-center in ul:

_x000D_
_x000D_
 <nav aria-label="Page navigation example">
    <ul class="pagination justify-content-center">
      <li class="page-item disabled">
        <a class="page-link" href="#" tabindex="-1">Previous</a>
      </li>
      <li class="page-item"><a class="page-link" href="#">1</a></li>
      <li class="page-item"><a class="page-link" href="#">2</a></li>
      <li class="page-item"><a class="page-link" href="#">3</a></li>
      <li class="page-item">
        <a class="page-link" href="#">Next</a>
      </li>
    </ul>
  </nav>

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" integrity="sha384-JcKb8q3iqJ61gNV9KGb8thSsNjpSL0n8PARn9HuZOnIxN0hoP+VmmDGMN5t9UJ0Z" crossorigin="anonymous">
_x000D_
_x000D_
_x000D_

See Pagination Bootstrap 4 for further information.

Javascript change color of text and background to input value

document.getElementById("fname").style.borderTopColor = 'red';
document.getElementById("fname").style.borderBottomColor = 'red';

Adding n hours to a date in Java?

by using Java 8 classes. we can manipulate date and time very easily as below.

LocalDateTime today = LocalDateTime.now();
LocalDateTime minusHours = today.minusHours(24);
LocalDateTime minusMinutes = minusHours.minusMinutes(30);
LocalDate localDate = LocalDate.from(minusMinutes);

Java resource as file

I had the same problem and was able to use the following:

// Load the directory as a resource
URL dir_url = ClassLoader.getSystemResource(dir_path);
// Turn the resource into a File object
File dir = new File(dir_url.toURI());
// List the directory
String files = dir.list()

SQL Server: Difference between PARTITION BY and GROUP BY

PARTITION BY Divides the result set into partitions. The window function is applied to each partition separately and computation restarts for each partition.

Found at this link: OVER Clause

When does Git refresh the list of remote branches?

I believe that if you run git branch --all from Bash that the list of remote and local branches you see will reflect what your local Git "knows" about at the time you run the command. Because your Git is always up to date with regard to the local branches in your system, the list of local branches will always be accurate.

However, for remote branches this need not be the case. Your local Git only knows about remote branches which it has seen in the last fetch (or pull). So it is possible that you might run git branch --all and not see a new remote branch which appeared after the last time you fetched or pulled.

To ensure that your local and remote branch list be up to date you can do a git fetch before running git branch --all.

For further information, the "remote" branches which appear when you run git branch --all are not really remote at all; they are actually local. For example, suppose there be a branch on the remote called feature which you have pulled at least once into your local Git. You will see origin/feature listed as a branch when you run git branch --all. But this branch is actually a local Git branch. When you do git fetch origin, this tracking branch gets updated with any new changes from the remote. This is why your local state can get stale, because there may be new remote branches, or your tracking branches can become stale.

Pandas timeseries plot setting x-axis major and minor ticks and labels

Both pandas and matplotlib.dates use matplotlib.units for locating the ticks.

But while matplotlib.dates has convenient ways to set the ticks manually, pandas seems to have the focus on auto formatting so far (you can have a look at the code for date conversion and formatting in pandas).

So for the moment it seems more reasonable to use matplotlib.dates (as mentioned by @BrenBarn in his comment).

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt 
import matplotlib.dates as dates

idx = pd.date_range('2011-05-01', '2011-07-01')
s = pd.Series(np.random.randn(len(idx)), index=idx)

fig, ax = plt.subplots()
ax.plot_date(idx.to_pydatetime(), s, 'v-')
ax.xaxis.set_minor_locator(dates.WeekdayLocator(byweekday=(1),
                                                interval=1))
ax.xaxis.set_minor_formatter(dates.DateFormatter('%d\n%a'))
ax.xaxis.grid(True, which="minor")
ax.yaxis.grid()
ax.xaxis.set_major_locator(dates.MonthLocator())
ax.xaxis.set_major_formatter(dates.DateFormatter('\n\n\n%b\n%Y'))
plt.tight_layout()
plt.show()

pandas_like_date_fomatting

(my locale is German, so that Tuesday [Tue] becomes Dienstag [Di])

How to deserialize a list using GSON or another JSON library in Java?

Be careful using the answer provide by @DevNG. Arrays.asList() returns internal implementation of ArrayList that doesn't implement some useful methods like add(), delete(), etc. If you call them an UnsupportedOperationException will be thrown. In order to get real ArrayList instance you need to write something like this:

List<Video> = new ArrayList<>(Arrays.asList(videoArray));

How do I turn off PHP Notices?

I prefer to not set the error_reporting inside my code. But in one case, a legacy product, there are so many notices, that they must be hidden.

So I used following snippet to set the serverside configured value for error_reporting but subtract the E_NOTICEs.

error_reporting(error_reporting() & ~E_NOTICE);

Now the error reporting setting can further be configured in php.ini or .htaccess. Only notices will always be disabled.

Base64 encoding and decoding in oracle

I've implemented this to send Cyrillic e-mails through my MS Exchange server.

function to_base64(t in varchar2) return varchar2 is
 begin
    return utl_raw.cast_to_varchar2(utl_encode.base64_encode(utl_raw.cast_to_raw(t)));
end to_base64;

Try it.

upd: after a minor adjustment I came up with this, so it works both ways now:

function from_base64(t in varchar2) return varchar2 is
begin
  return utl_raw.cast_to_varchar2(utl_encode.base64_decode(utl_raw.cast_to_raw(t)));
end from_base64;

You can check it:

SQL> set serveroutput on
SQL> 
SQL> declare
  2    function to_base64(t in varchar2) return varchar2 is
  3    begin
  4      return utl_raw.cast_to_varchar2(utl_encode.base64_encode(utl_raw.cast_to_raw(t)));
  5    end to_base64;
  6  
  7    function from_base64(t in varchar2) return varchar2 is
  8    begin
  9      return utl_raw.cast_to_varchar2(utl_encode.base64_decode(utl_raw.cast_to_raw    (t)));
 10    end from_base64;
 11  
 12  begin
 13    dbms_output.put_line(from_base64(to_base64('asdf')));
 14  end;
 15  /

asdf

PL/SQL procedure successfully completed

upd2: Ok, here's a sample conversion that works for CLOB I just came up with. Try to work it out for your blobs. :)

declare

  clobOriginal     clob;
  clobInBase64     clob;
  substring        varchar2(2000);
  n                pls_integer := 0;
  substring_length pls_integer := 2000;

  function to_base64(t in varchar2) return varchar2 is
  begin
    return utl_raw.cast_to_varchar2(utl_encode.base64_encode(utl_raw.cast_to_raw(t)));
  end to_base64;

  function from_base64(t in varchar2) return varchar2 is
  begin
    return utl_raw.cast_to_varchar2(utl_encode.base64_decode(utl_raw.cast_to_raw(t)));
  end from_base64;

begin

  select clobField into clobOriginal from clobTable where id = 1;

  while true loop

    /*we substract pieces of substring_length*/
    substring := dbms_lob.substr(clobOriginal,
                                 least(substring_length, substring_length * n + 1 - length(clobOriginal)),
                                 substring_length * n + 1);  
    /*if no substring is found  - then we've reached the end of blob*/

    if substring is null then
      exit;
    end if;  

    /*convert them to base64 encoding and stack it in new clob vadriable*/
    clobInBase64 := clobInBase64 || to_base64(substring);          
    n := n + 1;  

  end loop;

  n := 0;
  clobOriginal := null;

  /*then we do the very same thing backwards - decode base64*/
  while true loop 

    substring := dbms_lob.substr(clobInBase64,
                                 least(substring_length, substring_length * n + 1 - length(clobInBase64)),
                                 substring_length * n + 1);  
    if substring is null then
      exit;
    end if;  
    clobOriginal := clobOriginal || from_base64(substring);  
    n := n + 1;  
  end loop; 

      /*and insert the data in our sample table - to ensure it's the same*/
  insert into clobTable (id, anotherClobField) values (1, clobOriginal);

end;

Open files in 'rt' and 'wt' modes

t indicates for text mode

https://docs.python.org/release/3.1.5/library/functions.html#open

on linux, there's no difference between text mode and binary mode, however, in windows, they converts \n to \r\n when text mode.

http://www.cygwin.com/cygwin-ug-net/using-textbinary.html

Write to Windows Application Event Log

This is the logger class that I use. The private Log() method has EventLog.WriteEntry() in it, which is how you actually write to the event log. I'm including all of this code here because it's handy. In addition to logging, this class will also make sure the message isn't too long to write to the event log (it will truncate the message). If the message was too long, you'd get an exception. The caller can also specify the source. If the caller doesn't, this class will get the source. Hope it helps.

By the way, you can get an ObjectDumper from the web. I didn't want to post all that here. I got mine from here: C:\Program Files (x86)\Microsoft Visual Studio 10.0\Samples\1033\CSharpSamples.zip\LinqSamples\ObjectDumper

using System;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.Linq;
using System.Reflection;
using Xanico.Core.Utilities;

namespace Xanico.Core
{
    /// <summary>
    /// Logging operations
    /// </summary>
    public static class Logger
    {
        // Note: The actual limit is higher than this, but different Microsoft operating systems actually have
        //       different limits. So just use 30,000 to be safe.
        private const int MaxEventLogEntryLength = 30000;

        /// <summary>
        /// Gets or sets the source/caller. When logging, this logger class will attempt to get the
        /// name of the executing/entry assembly and use that as the source when writing to a log.
        /// In some cases, this class can't get the name of the executing assembly. This only seems
        /// to happen though when the caller is in a separate domain created by its caller. So,
        /// unless you're in that situation, there is no reason to set this. However, if there is
        /// any reason that the source isn't being correctly logged, just set it here when your
        /// process starts.
        /// </summary>
        public static string Source { get; set; }

        /// <summary>
        /// Logs the message, but only if debug logging is true.
        /// </summary>
        /// <param name="message">The message.</param>
        /// <param name="debugLoggingEnabled">if set to <c>true</c> [debug logging enabled].</param>
        /// <param name="source">The name of the app/process calling the logging method. If not provided,
        /// an attempt will be made to get the name of the calling process.</param>
        public static void LogDebug(string message, bool debugLoggingEnabled, string source = "")
        {
            if (debugLoggingEnabled == false) { return; }

            Log(message, EventLogEntryType.Information, source);
        }

        /// <summary>
        /// Logs the information.
        /// </summary>
        /// <param name="message">The message.</param>
        /// <param name="source">The name of the app/process calling the logging method. If not provided,
        /// an attempt will be made to get the name of the calling process.</param>
        public static void LogInformation(string message, string source = "")
        {
            Log(message, EventLogEntryType.Information, source);
        }

        /// <summary>
        /// Logs the warning.
        /// </summary>
        /// <param name="message">The message.</param>
        /// <param name="source">The name of the app/process calling the logging method. If not provided,
        /// an attempt will be made to get the name of the calling process.</param>
        public static void LogWarning(string message, string source = "")
        {
            Log(message, EventLogEntryType.Warning, source);
        }

        /// <summary>
        /// Logs the exception.
        /// </summary>
        /// <param name="ex">The ex.</param>
        /// <param name="source">The name of the app/process calling the logging method. If not provided,
        /// an attempt will be made to get the name of the calling process.</param>
        public static void LogException(Exception ex, string source = "")
        {
            if (ex == null) { throw new ArgumentNullException("ex"); }

            if (Environment.UserInteractive)
            {
                Console.WriteLine(ex.ToString());
            }

            Log(ex.ToString(), EventLogEntryType.Error, source);
        }

        /// <summary>
        /// Recursively gets the properties and values of an object and dumps that to the log.
        /// </summary>
        /// <param name="theObject">The object to log</param>
        [SuppressMessage("Microsoft.Globalization", "CA1303:Do not pass literals as localized parameters", MessageId = "Xanico.Core.Logger.Log(System.String,System.Diagnostics.EventLogEntryType,System.String)")]
        [SuppressMessage("Microsoft.Naming", "CA1720:IdentifiersShouldNotContainTypeNames", MessageId = "object")]
        public static void LogObjectDump(object theObject, string objectName, string source = "")
        {
            const int objectDepth = 5;
            string objectDump = ObjectDumper.GetObjectDump(theObject, objectDepth);

            string prefix = string.Format(CultureInfo.CurrentCulture,
                                          "{0} object dump:{1}",
                                          objectName,
                                          Environment.NewLine);

            Log(prefix + objectDump, EventLogEntryType.Warning, source);
        }

        private static void Log(string message, EventLogEntryType entryType, string source)
        {
            // Note: I got an error that the security log was inaccessible. To get around it, I ran the app as administrator
            //       just once, then I could run it from within VS.

            if (string.IsNullOrWhiteSpace(source))
            {
                source = GetSource();
            }

            string possiblyTruncatedMessage = EnsureLogMessageLimit(message);
            EventLog.WriteEntry(source, possiblyTruncatedMessage, entryType);

            // If we're running a console app, also write the message to the console window.
            if (Environment.UserInteractive)
            {
                Console.WriteLine(message);
            }
        }

        private static string GetSource()
        {
            // If the caller has explicitly set a source value, just use it.
            if (!string.IsNullOrWhiteSpace(Source)) { return Source; }

            try
            {
                var assembly = Assembly.GetEntryAssembly();

                // GetEntryAssembly() can return null when called in the context of a unit test project.
                // That can also happen when called from an app hosted in IIS, or even a windows service.

                if (assembly == null)
                {
                    assembly = Assembly.GetExecutingAssembly();
                }


                if (assembly == null)
                {
                    // From http://stackoverflow.com/a/14165787/279516:
                    assembly = new StackTrace().GetFrames().Last().GetMethod().Module.Assembly;
                }

                if (assembly == null) { return "Unknown"; }

                return assembly.GetName().Name;
            }
            catch
            {
                return "Unknown";
            }
        }

        // Ensures that the log message entry text length does not exceed the event log viewer maximum length of 32766 characters.
        private static string EnsureLogMessageLimit(string logMessage)
        {
            if (logMessage.Length > MaxEventLogEntryLength)
            {
                string truncateWarningText = string.Format(CultureInfo.CurrentCulture, "... | Log Message Truncated [ Limit: {0} ]", MaxEventLogEntryLength);

                // Set the message to the max minus enough room to add the truncate warning.
                logMessage = logMessage.Substring(0, MaxEventLogEntryLength - truncateWarningText.Length);

                logMessage = string.Format(CultureInfo.CurrentCulture, "{0}{1}", logMessage, truncateWarningText);
            }

            return logMessage;
        }
    }
}

CSS performance relative to translateZ(0)

I can attest to the fact that -webkit-transform: translate3d(0, 0, 0); will mess with the new position: -webkit-sticky; property. With a left drawer navigation pattern that I was working on, the hardware acceleration I wanted with the transform property was messing with the fixed positioning of my top nav bar. I turned off the transform and the positioning worked fine.

Luckily, I seem to have had hardware acceleration on already, because I had -webkit-font-smoothing: antialiased on the html element. I was testing this behavior in iOS7 and Android.

git diff between cloned and original remote repository

This example might help someone:

Note "origin" is my alias for remote "What is on Github"
Note "mybranch" is my alias for my branch "what is local" that I'm syncing with github
--your branch name is 'master' if you didn't create one. However, I'm using the different name mybranch to show where the branch name parameter is used.


What exactly are my remote repos on github?

$ git remote -v
origin  https://github.com/flipmcf/Playground.git (fetch)
origin  https://github.com/flipmcf/Playground.git (push)

Add the "other github repository of the same code" - we call this a fork:

$ git remote add someOtherRepo https://github.com/otherUser/Playground.git

$git remote -v
origin  https://github.com/flipmcf/Playground.git (fetch)
origin  https://github.com/flipmcf/Playground.git (push)
someOtherRepo https://github.com/otherUser/Playground.git (push)
someOtherRepo https://github.com/otherUser/Playground.git (fetch)

make sure our local repo is up to date:

$ git fetch

Change some stuff locally. let's say file ./foo/bar.py

$ git status
# On branch mybranch
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#   modified:   foo/bar.py

Review my uncommitted changes

$ git diff mybranch
diff --git a/playground/foo/bar.py b/playground/foo/bar.py
index b4fb1be..516323b 100655
--- a/playground/foo/bar.py
+++ b/playground/foo/bar.py
@@ -1,27 +1,29 @@
- This line is wrong
+ This line is fixed now - yea!
+ And I added this line too.

Commit locally.

$ git commit foo/bar.py -m"I changed stuff"
[myfork 9f31ff7] I changed stuff
1 files changed, 2 insertions(+), 1 deletions(-)

Now, I'm different than my remote (on github)

$ git status
# On branch mybranch
# Your branch is ahead of 'origin/mybranch' by 1 commit.
#
nothing to commit (working directory clean)

Diff this with remote - your fork: (this is frequently done with git diff master origin)

$ git diff mybranch origin
diff --git a/playground/foo/bar.py b/playground/foo/bar.py
index 516323b..b4fb1be 100655
--- a/playground/foo/bar.py
+++ b/playground/foo/bar.py
@@ -1,27 +1,29 @@
- This line is wrong
+ This line is fixed now - yea!
+ And I added this line too.

(git push to apply these to remote)

How does my remote branch differ from the remote master branch?

$ git diff origin/mybranch origin/master

How does my local stuff differ from the remote master branch?

$ git diff origin/master

How does my stuff differ from someone else's fork, master branch of the same repo?

$git diff mybranch someOtherRepo/master

Iterating through a Collection, avoiding ConcurrentModificationException when removing objects in a loop

People are asserting one can't remove from a Collection being iterated by a foreach loop. I just wanted to point out that is technically incorrect and describe exactly (I know the OP's question is so advanced as to obviate knowing this) the code behind that assumption:

for (TouchableObj obj : untouchedSet) {  // <--- This is where ConcurrentModificationException strikes
    if (obj.isTouched()) {
        untouchedSet.remove(obj);
        touchedSt.add(obj);
        break;  // this is key to avoiding returning to the foreach
    }
}

It isn't that you can't remove from the iterated Colletion rather that you can't then continue iteration once you do. Hence the break in the code above.

Apologies if this answer is a somewhat specialist use-case and more suited to the original thread I arrived here from, that one is marked as a duplicate (despite this thread appearing more nuanced) of this and locked.

How do I disable form fields using CSS?

This can be done for a non-critical purpose by putting an overlay on top of your input element. Here's my example in pure HTML and CSS.

https://jsfiddle.net/1tL40L99/

    <div id="container">
        <input name="name" type="text" value="Text input here" />
        <span id="overlay"></span>
    </div>

    <style>
        #container {
            width: 300px;
            height: 50px;
            position: relative;
        }
        #container input[type="text"] {
            position: relative;
            top: 15px;
            z-index: 1;
            width: 200px;
            display: block;
            margin: 0 auto;
        }
        #container #overlay {
            width: 300px;
            height: 50px;
            position: absolute;
            top: 0px;
            left: 0px;
            z-index: 2;
            background: rgba(255,0,0, .5);
        }
    </style>

Adding a Time to a DateTime in C#

If you are using two DateTime objects, one to store the date the other the time, you could do the following:

var date = new DateTime(2016,6,28);

var time = new DateTime(1,1,1,13,13,13);

var combinedDateTime = date.AddTicks(time.TimeOfDay.Ticks);

An example of this can be found here

java.lang.VerifyError: Expecting a stackmap frame at branch target JDK 1.7

I ran into this problem and try using the flag -noverify which really works. It is because of the new bytecode verifier. So the flag should really work. I am using JDK 1.7.

Note: This would not work if you are using JDK 1.8

How do I replace multiple spaces with a single space in C#?

I like to use:

myString = Regex.Replace(myString, @"\s+", " ");

Since it will catch runs of any kind of whitespace (e.g. tabs, newlines, etc.) and replace them with a single space.

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

You can use a different overload of Replace() that takes string.

val = val.Replace("-", string.Empty)

Pandas join issue: columns overlap but no suffix specified

This error indicates that the two tables have the 1 or more column names that have the same column name. The error message translates to: "I can see the same column in both tables but you haven't told me to rename either before bringing one of them in"

You either want to delete one of the columns before bringing it in from the other on using del df['column name'], or use lsuffix to re-write the original column, or rsuffix to rename the one that is being brought it.

df_a.join(df_b, on='mukey', how='left', lsuffix='_left', rsuffix='_right')

Getting the Username from the HKEY_USERS values

If you look at either of the following keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\hivelist

You can find a list of the SIDs there with various values, including where their "home paths" which includes their usernames.

I'm not sure how dependable this is and I wouldn't recommend messing about with this unless you're really sure what you're doing.

Replace all particular values in a data frame

Here are a couple dplyr options:

library(dplyr)

# all columns:
df %>% 
  mutate_all(~na_if(., ''))

# specific column types:
df %>% 
  mutate_if(is.factor, ~na_if(., ''))

# specific columns:  
df %>% 
  mutate_at(vars(A, B), ~na_if(., ''))

# or:
df %>% 
  mutate(A = replace(A, A == '', NA))

# replace can be used if you want something other than NA:
df %>% 
  mutate(A = as.character(A)) %>% 
  mutate(A = replace(A, A == '', 'used to be empty'))

Xamarin.Forms ListView: Set the highlight color of a tapped item

Here is the purely cross platform and neat way:

1) Define a trigger action

namespace CustomTriggers {
   public class DeselectListViewItemAction:TriggerAction<ListView> {
       protected override void Invoke(ListView sender) {
                sender.SelectedItem = null;
       }
   }
}

2) Apply the above class instance as an EventTrigger action in XAML as below

 <ListView x:Name="YourListView" ItemsSource="{Binding ViewModelItems}">
    <ListView.Triggers>
        <EventTrigger Event="ItemSelected">
            <customTriggers:DeselectListViewItemAction></customTriggers:DeselectListViewItemAction>
        </EventTrigger>
    </ListView.Triggers>
</ListView>

Don't forget to add xmlns:customTriggers="clr-namespace:CustomTriggers;assembly=ProjectAssembly"

Note: Because none of your items are in selected mode, selection styling will not get applied on either of the platforms.

mongoError: Topology was destroyed

You need to restart mongo to solve the topology error, then just change some options of mongoose or mongoclient to overcome this problem:

var mongoOptions = {
    useMongoClient: true,
    keepAlive: 1,
    connectTimeoutMS: 30000,
    reconnectTries: Number.MAX_VALUE,
    reconnectInterval: 5000,
    useNewUrlParser: true
}

mongoose.connect(mongoDevString,mongoOptions);

Java Long primitive type maximum limit

It will overflow and wrap around to Long.MIN_VALUE.

Its not too likely though. Even if you increment 1,000,000 times per second it will take about 300,000 years to overflow.

CSS: transition opacity on mouse-out?

$(window).scroll(function() {    
    $('.logo_container, .slogan').css({
        "opacity" : ".1",
        "transition" : "opacity .8s ease-in-out"
    });
});

Check the fiddle: http://jsfiddle.net/2k3hfwo0/2/

Array.sort() doesn't sort numbers correctly

I've tried different numbers, and it always acts as if the 0s aren't there and sorts the numbers correctly otherwise. Anyone know why?

You're getting a lexicographical sort (e.g. convert objects to strings, and sort them in dictionary order), which is the default sort behavior in Javascript:

https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/sort

array.sort([compareFunction])

Parameters

compareFunction

Specifies a function that defines the sort order. If omitted, the array is sorted lexicographically (in dictionary order) according to the string conversion of each element.

In the ECMAscript specification (the normative reference for the generic Javascript), ECMA-262, 3rd ed., section 15.4.4.11, the default sort order is lexicographical, although they don't come out and say it, instead giving the steps for a conceptual sort function that calls the given compare function if necessary, otherwise comparing the arguments when converted to strings:

13. If the argument comparefn is undefined, go to step 16.
14. Call comparefn with arguments x and y.
15. Return Result(14).
16. Call ToString(x).
17. Call ToString(y).
18. If Result(16) < Result(17), return -1.
19. If Result(16) > Result(17), return 1.
20. Return +0.

Doing a join across two databases with different collations on SQL Server and getting an error

A general purpose way is to coerce the collation to DATABASE_DEFAULT. This removes hardcoding the collation name which could change.

It's also useful for temp table and table variables, and where you may not know the server collation (eg you are a vendor placing your system on the customer's server)

select
    sone_field collate DATABASE_DEFAULT
from
    table_1
    inner join
    table_2 on table_1.field collate DATABASE_DEFAULT = table_2.field
where whatever

"Failed to load platform plugin "xcb" " while launching qt5 app on linux without qt installed

As was posted earlier, you need to make sure you install the platform plugins when you deploy your application. Depending on how you want to deploy things, there are two methods to tell your application where the platform plugins (e.g. platforms/plugins/libqxcb.so) are at runtime which may work for you.

The first is to export the path to the directory through the QT_QPA_PLATFORM_PLUGIN_PATH variable.

QT_QPA_PLATFORM_PLUGIN_PATH=path/to/plugins ./my_qt_app

or

export QT_QPA_PLATFORM_PLUGIN_PATH=path/to/plugins
./my_qt_app

The other option, which I prefer is to create a qt.conf file in the same directory as your executable. The contents of which would be:

[Paths]
Plugins=/path/to/plugins

More information regarding this can be found here and at using qt.conf

Excel - Combine multiple columns into one column

Try this. Click anywhere in your range of data and then use this macro:

Sub CombineColumns()
Dim rng As Range
Dim iCol As Integer
Dim lastCell As Integer

Set rng = ActiveCell.CurrentRegion
lastCell = rng.Columns(1).Rows.Count + 1

For iCol = 2 To rng.Columns.Count
    Range(Cells(1, iCol), Cells(rng.Columns(iCol).Rows.Count, iCol)).Cut
    ActiveSheet.Paste Destination:=Cells(lastCell, 1)
    lastCell = lastCell + rng.Columns(iCol).Rows.Count
Next iCol
End Sub

Could not load file or assembly 'log4net, Version=1.2.10.0, Culture=neutral, PublicKeyToken=692fbea5521e1304'

If you don't see log4net.dll in %systemdrive%\windows\assembly\ on the machine you are attempting to deploy it on, it is likely you haven't successfully installed the redistributable for Crystal Reports for .Net Framework 4.0

Install (or reinstall) the latest service pack from http://scn.sap.com/docs/DOC-7824 (SAP Crystal Reports, developer version for Microsoft Visual Studio Updates & Runtime Downloads)

That runtime distribution should add log4net to the GAC along with a bunch of CrystalDecisions dll's

MySQL, Check if a column exists in a table with SQL

Select just column_name from information schema and put the result of this query into variable. Then test the variable to decide if table needs alteration or not.

P.S. Don't foget to specify TABLE_SCHEMA for COLUMNS table as well.

Real escape string and PDO

Use prepared statements. Those keep the data and syntax apart, which removes the need for escaping MySQL data. See e.g. this tutorial.

Allow multi-line in EditText view in Android?

if some one is using AppCompatEditText then you need to set inputType="textMultiLine" here is the code you can copy


   <androidx.appcompat.widget.AppCompatEditText
        android:padding="@dimen/_8sdp"
        android:id="@+id/etNote"
        android:minLines="6"
        android:singleLine="false"
        android:lines="8"
        android:scrollbars="vertical"
        android:background="@drawable/rounded_border"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="@dimen/_25sdp"
        android:layout_marginTop="32dp"
        android:layout_marginEnd="@dimen/_25sdp"
        android:autofillHints=""

        android:gravity="start|top"
        android:inputType="textMultiLine"
         />

for background

   <?xml version="1.0" encoding="utf-8"?>
   <shape android:shape="rectangle" 
    xmlns:android="http://schemas.android.com/apk/res/android">
   <corners android:radius="@dimen/_5sdp"/>
   <stroke android:width="1dp" android:color="#C8C8C8"/>
   </shape>

Close pre-existing figures in matplotlib when running from eclipse

Nothing works in my case using the scripts above but I was able to close these figures from eclipse console bar by clicking on Terminate ALL (two red nested squares icon).

The representation of if-elseif-else in EL using JSF

You can use "ELSE IF" using conditional operator in expression language as below:

 <p:outputLabel value="#{transaction.status.equals('PNDNG')?'Pending':
                                     transaction.status.equals('RJCTD')?'Rejected':
                                     transaction.status.equals('CNFRMD')?'Confirmed':
                                     transaction.status.equals('PSTD')?'Posted':''}"/>

how concatenate two variables in batch script?

You can do it without setlocal, because of the setlocal command the variable won't survive an endlocal because it was created in setlocal. In this way the variable will be defined the right way.

To do that use this code:

set var1=A

set var2=B

set AB=hi

call set newvar=%%%var1%%var2%%%

echo %newvar% 

Note: You MUST use call before you set the variable or it won't work.

No converter found capable of converting from type to type

Turns out, when the table name is different than the model name, you have to change the annotations to:

@Entity
@Table(name = "table_name")
class WhateverNameYouWant {
    ...

Instead of simply using the @Entity annotation.

What was weird for me, is that the class it was trying to convert to didn't exist. This worked for me.

Way to go from recursion to iteration

Even using stack will not convert a recursive algorithm into iterative. Normal recursion is function based recursion and if we use stack then it becomes stack based recursion. But its still recursion.

For recursive algorithms, space complexity is O(N) and time complexity is O(N). For iterative algorithms, space complexity is O(1) and time complexity is O(N).

But if we use stack things in terms of complexity remains same. I think only tail recursion can be converted into iteration.

Python - List of unique dictionaries

There are a lot of answers here, so let me add another:

import json
from typing import List

def dedup_dicts(items: List[dict]):
    dedupped = [ json.loads(i) for i in set(json.dumps(item, sort_keys=True) for item in items)]
    return dedupped

items = [
    {'id': 1, 'name': 'john', 'age': 34},
    {'id': 1, 'name': 'john', 'age': 34},
    {'id': 2, 'name': 'hanna', 'age': 30},
]
dedup_dicts(items)

jQuery click not working for dynamically created items

Try something like

$("#container").on('click', 'someLinkSelector', function(){ $("#container").html( <new html with new spans> ) });

You basically need to attach your events from a non-dynamic part of the DOM so it can watch for dynamically-created elements.

Ajax post request in laravel 5 return error 500 (Internal Server Error)

In App\Http\Middleware\VerifyCsrfToken.php you could try updating the file to something like:

class VerifyCsrfToken extends BaseVerifier {

    private $openRoutes =
    [
        ...excluded routes
    ];

    public function handle($request, Closure $next)
    {
        foreach($this->openRoutes as $route)
        {
            if ($request->is($route))
            {
                return $next($request);
            }
        }

        return parent::handle($request, $next);
    }
};

This allows you to explicitly bypass specific routes that you do not want verified without disabling csrf validation globally.

MySQL - Meaning of "PRIMARY KEY", "UNIQUE KEY" and "KEY" when used together while creating a table

A key is just a normal index. A way over simplification is to think of it like a card catalog at a library. It points MySQL in the right direction.

A unique key is also used for improved searching speed, but it has the constraint that there can be no duplicated items (there are no two x and y where x is not y and x == y).

The manual explains it as follows:

A UNIQUE index creates a constraint such that all values in the index must be distinct. An error occurs if you try to add a new row with a key value that matches an existing row. This constraint does not apply to NULL values except for the BDB storage engine. For other engines, a UNIQUE index permits multiple NULL values for columns that can contain NULL. If you specify a prefix value for a column in a UNIQUE index, the column values must be unique within the prefix.

A primary key is a 'special' unique key. It basically is a unique key, except that it's used to identify something.

The manual explains how indexes are used in general: here.

In MSSQL, the concepts are similar. There are indexes, unique constraints and primary keys.

Untested, but I believe the MSSQL equivalent is:

CREATE TABLE tmp (
  id int NOT NULL PRIMARY KEY IDENTITY,
  uid varchar(255) NOT NULL CONSTRAINT uid_unique UNIQUE,
  name varchar(255) NOT NULL,
  tag int NOT NULL DEFAULT 0,
  description varchar(255),
);

CREATE INDEX idx_name ON tmp (name);
CREATE INDEX idx_tag ON tmp (tag);

Edit: the code above is tested to be correct; however, I suspect that there's a much better syntax for doing it. Been a while since I've used SQL server, and apparently I've forgotten quite a bit :).

How to upload a project to Github

How to upload a project to Github from scratch

Follow these steps to project to Github

1) git init

2) git add .

3) git commit -m "Add all my files"

4) git remote add origin https://github.com/yourusername/your-repo-name.git

Upload of project from scratch require git pull origin master.

5) git pull origin master

6) git push origin master

Convert object string to JSON

Your best and safest bet would be JSON5 – JSON for Humans. It is created specifically for that use case.

_x000D_
_x000D_
const result = JSON5.parse("{ hello: 'world', places: ['Africa', 'America', 'Asia', 'Australia'] }");_x000D_
_x000D_
console.log(JSON.stringify(result));
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/json5/0.5.1/json5.min.js"></script>
_x000D_
_x000D_
_x000D_

List of <p:ajax> events

I've got the list in debug mode; first I saw the point at which the error was thrown

javax.faces.view.facelets.TagException: /showcase/partial_submit.xhtml @26,36 Event:changed is not supported. org.primefaces.component.behavior.ajax.AjaxBehaviorHandler.applyAttachedObject(AjaxBehaviorHandler.java:179) org.primefaces.component.behavior.ajax.AjaxBehaviorHandler.apply(AjaxBehaviorHandler.java:157)

and then I debugged AjaxBehaviorHandler

enter image description here

so if you want discover the right list of supported event, you can generate an error (using an event name that is wrong), and follow this way

Using SQL LOADER in Oracle to import CSV file

If your text is: Joe said, "Fred was here with his "Wife"".
This is saved in a CSV as:
"Joe said, ""Fred was here with his ""Wife""""."
(Rule is double quotes go around the whole field, and double quotes are converted to two double quotes). So a simple Optionally Enclosed By clause is needed but not sufficient. CSVs are tough due to this rule. You can sometimes use a Replace clause in the loader for that field but depending on your data this may not be enough. Often pre-processing of a CSV is needed to load in Oracle. Or save it as an XLS and use Oracle SQL Developer app to import to the table - great for one-time work, not so good for scripting.

C# HttpClient 4.5 multipart/form-data upload

my result looks like this:

public static async Task<string> Upload(byte[] image)
{
     using (var client = new HttpClient())
     {
         using (var content =
             new MultipartFormDataContent("Upload----" + DateTime.Now.ToString(CultureInfo.InvariantCulture)))
         {
             content.Add(new StreamContent(new MemoryStream(image)), "bilddatei", "upload.jpg");

              using (
                 var message =
                     await client.PostAsync("http://www.directupload.net/index.php?mode=upload", content))
              {
                  var input = await message.Content.ReadAsStringAsync();

                  return !string.IsNullOrWhiteSpace(input) ? Regex.Match(input, @"http://\w*\.directupload\.net/images/\d*/\w*\.[a-z]{3}").Value : null;
              }
          }
     }
}

Detect whether Office is 32bit or 64bit via the registry

I don't have a key called bitness in either of these folders. I do have a key called "default" in both of these folders and the value is "unset" My computer came with office 2010 starter (I assume 64 bit). I removed it and tried to do a full install of 32 bit office. I keep getting the following message. the file is incompatible, check to see whether you need x86 or x64 version of the program.

any advice for me?

Fatal error: Maximum execution time of 30 seconds exceeded in C:\xampp\htdocs\wordpress\wp-includes\class-http.php on line 1610

Please

  1. locate the file [XAMPP Installation Directory]\php\php.ini (e.g. C:\xampp\php\php.ini)
  2. open php.ini in Notepad or any Text editor
  3. locate the line containing max_execution_time and
  4. increase the value from 30 to some larger number (e.g. set: max_execution_time = 90)
  5. then restart Apache web server from the XAMPP control panel

If there will still be the same error after that, try to increase the value for the max_execution_time further more.

Naming Classes - How to avoid calling everything a "<WhatEver>Manager"?

You can take a look at source-code-wordle.de, I have analyzed there the most frequently used suffixes of class names of the .NET framework and some other libraries.

The top 20 are:

  • attribute
  • type
  • helper
  • collection
  • converter
  • handler
  • info
  • provider
  • exception
  • service
  • element
  • manager
  • node
  • option
  • factory
  • context
  • item
  • designer
  • base
  • editor

Show a message box from a class in c#?

using System.Windows.Forms;

public class message
{
    static void Main()
    {  
        MessageBox.Show("Hello World!"); 
    }
}

Create a branch in Git from another branch

Do simultaneous work on the dev branch. What happens is that in your scenario the feature branch moves forward from the tip of the dev branch, but the dev branch does not change. It's easier to draw as a straight line, because it can be thought of as forward motion. You made it to point A on dev, and from there you simply continued on a parallel path. The two branches have not really diverged.

Now, if you make a commit on dev, before merging, you will again begin at the same commit, A, but now features will go to C and dev to B. This will show the split you are trying to visualize, as the branches have now diverged.

*-----*Dev-------*Feature

Versus

       /----*DevB
*-----*DevA
       \----*FeatureC

C++ Object Instantiation

On the contrary, you should always prefer stack allocations, to the extent that as a rule of thumb, you should never have new/delete in your user code.

As you say, when the variable is declared on the stack, its destructor is automatically called when it goes out of scope, which is your main tool for tracking resource lifetime and avoiding leaks.

So in general, every time you need to allocate a resource, whether it's memory (by calling new), file handles, sockets or anything else, wrap it in a class where the constructor acquires the resource, and the destructor releases it. Then you can create an object of that type on the stack, and you're guaranteed that your resource gets freed when it goes out of scope. That way you don't have to track your new/delete pairs everywhere to ensure you avoid memory leaks.

The most common name for this idiom is RAII

Also look into smart pointer classes which are used to wrap the resulting pointers on the rare cases when you do have to allocate something with new outside a dedicated RAII object. You instead pass the pointer to a smart pointer, which then tracks its lifetime, for example by reference counting, and calls the destructor when the last reference goes out of scope. The standard library has std::unique_ptr for simple scope-based management, and std::shared_ptr which does reference counting to implement shared ownership.

Many tutorials demonstrate object instantiation using a snippet such as ...

So what you've discovered is that most tutorials suck. ;) Most tutorials teach you lousy C++ practices, including calling new/delete to create variables when it's not necessary, and giving you a hard time tracking lifetime of your allocations.

Fast way to concatenate strings in nodeJS/JavaScript

There is not really any other way in JavaScript to concatenate strings.
You could theoretically use .concat(), but that's way slower than just +

Libraries are more often than not slower than native JavaScript, especially on basic operations like string concatenation, or numerical operations.

Simply put: + is the fastest.

Python - AttributeError: 'numpy.ndarray' object has no attribute 'append'

for root, dirs, files in os.walk(directory):
    for file in files:
        floc = file
        im = Image.open(str(directory) + '\\' + floc)
        pix = np.array(im.getdata())
        pixels.append(pix)
        labels.append(1)   # append(i)???

So far ok. But you want to leave pixels as a list until you are done with the iteration.

pixels = np.array(pixels)
labels = np.array(labels)

You had this indention right in your other question. What happened? previous

Iterating, collecting values in a list, and then at the end joining things into a bigger array is the right way. To make things clear I often prefer to use notation like:

alist = []
for ..
    alist.append(...)
arr = np.array(alist)

If names indicate something about the nature of the object I'm less likely to get errors like yours.

I don't understand what you are trying to do with traindata. I doubt if you need to build it during the loop. pixels and labels have the basic information.

That

traindata = np.array([traindata[i][i],traindata[1]], dtype=object)

comes from the previous question. I'm not sure you understand that answer.

traindata = []
traindata.append(pixels)
traindata.append(labels)

if done outside the loop is just

traindata = [pixels, labels]

labels is a 1d array, a bunch of 1s (or [0,1,2,3...] if my guess is right). pixels is a higher dimension array. What is its shape?

Stop right there. There's no point in turning that list into an array. You can save the list with pickle.

You are copying code from an earlier question, and getting the formatting wrong. cPickle very large amount of data

List append() in for loop

No need to re-assign.

a=[]
for i in range(5):    
    a.append(i)
a

What causes javac to issue the "uses unchecked or unsafe operations" warning

I just want to add one example of the kind of unchecked warning I see quite often. If you use classes that implement an interface like Serializable, often you will call methods that return objects of the interface, and not the actual class. If the class being returned must be cast to a type based on generics, you can get this warning.

Here is a brief (and somewhat silly) example to demonstrate:

import java.io.Serializable;

public class SimpleGenericClass<T> implements Serializable {

    public Serializable getInstance() {
        return this;
    }

    // @SuppressWarnings("unchecked")
    public static void main() {

        SimpleGenericClass<String> original = new SimpleGenericClass<String>();

        //  java: unchecked cast
        //    required: SimpleGenericClass<java.lang.String>
        //    found:    java.io.Serializable
        SimpleGenericClass<String> returned =
                (SimpleGenericClass<String>) original.getInstance();
    }
}

getInstance() returns an object that implements Serializable. This must be cast to the actual type, but this is an unchecked cast.

counting number of directories in a specific directory

Count all files and subfolders, windows style:

dir=/YOUR/PATH;f=$(find $dir -type f | wc -l); d=$(find $dir -mindepth 1 -type d | wc -l); echo "$f Files, $d Folders"

linq query to return distinct field values from a list of objects

Sure, use Enumerable.Distinct.

Given a collection of obj (e.g. foo), you'd do something like this:

var distinctTypeIDs = foo.Select(x => x.typeID).Distinct();

JavaScript replace/regex

You need to double escape any RegExp characters (once for the slash in the string and once for the regexp):

  "$TESTONE $TESTONE".replace( new RegExp("\\$TESTONE","gm"),"foo")

Otherwise, it looks for the end of the line and 'TESTONE' (which it never finds).

Personally, I'm not a big fan of building regexp's using strings for this reason. The level of escaping that's needed could lead you to drink. I'm sure others feel differently though and like drinking when writing regexes.

How to get the real and total length of char * (char array)?

Legit question. I personally think people confuse pointers with arrays as a result of character pointers (char*), which serve almost the same purpose as character arrays (char __[X]). This means that pointers and arrays are not the same, so pointers of course don't contain a specific size, only an address if I could say so. But nonetheless you can try something similar to strlen.

int ssize(const char* s)
{
    for (int i = 0; ; i++)
        if (s[i] == 0)
            return i;

    return 0;
}

QLabel: set color of text and background

The best and recommended way is to use Qt Style Sheet.

To change the text color and background color of a QLabel, here is what I would do :

QLabel* pLabel = new QLabel;
pLabel->setStyleSheet("QLabel { background-color : red; color : blue; }");

You could also avoid using Qt Style Sheets and change the QPalette colors of your QLabel, but you might get different results on different platforms and/or styles.

As Qt documentation states :

Using a QPalette isn't guaranteed to work for all styles, because style authors are restricted by the different platforms' guidelines and by the native theme engine.

But you could do something like this :

 QPalette palette = ui->pLabel->palette();
 palette.setColor(ui->pLabel->backgroundRole(), Qt::yellow);
 palette.setColor(ui->pLabel->foregroundRole(), Qt::yellow);
 ui->pLabel->setPalette(palette);

But as I said, I strongly suggest not to use the palette and go for Qt Style Sheet.

Default settings Raspberry Pi /etc/network/interfaces

These are the default settings I have for /etc/network/interfaces (including WiFi settings) for my Raspberry Pi 1:

auto lo

iface lo inet loopback
iface eth0 inet dhcp

allow-hotplug wlan0
iface wlan0 inet manual
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp

VBA Print to PDF and Save with Automatic File Name

Hopefully this is self explanatory enough. Use the comments in the code to help understand what is happening. Pass a single cell to this function. The value of that cell will be the base file name. If the cell contains "AwesomeData" then we will try and create a file in the current users desktop called AwesomeData.pdf. If that already exists then try AwesomeData2.pdf and so on. In your code you could just replace the lines filename = Application..... with filename = GetFileName(Range("A1"))

Function GetFileName(rngNamedCell As Range) As String
    Dim strSaveDirectory As String: strSaveDirectory = ""
    Dim strFileName As String: strFileName = ""
    Dim strTestPath As String: strTestPath = ""
    Dim strFileBaseName As String: strFileBaseName = ""
    Dim strFilePath As String: strFilePath = ""
    Dim intFileCounterIndex As Integer: intFileCounterIndex = 1

    ' Get the users desktop directory.
    strSaveDirectory = Environ("USERPROFILE") & "\Desktop\"
    Debug.Print "Saving to: " & strSaveDirectory

    ' Base file name
    strFileBaseName = Trim(rngNamedCell.Value)
    Debug.Print "File Name will contain: " & strFileBaseName

    ' Loop until we find a free file number
    Do
        If intFileCounterIndex > 1 Then
            ' Build test path base on current counter exists.
            strTestPath = strSaveDirectory & strFileBaseName & Trim(Str(intFileCounterIndex)) & ".pdf"
        Else
            ' Build test path base just on base name to see if it exists.
            strTestPath = strSaveDirectory & strFileBaseName & ".pdf"
        End If

        If (Dir(strTestPath) = "") Then
            ' This file path does not currently exist. Use that.
            strFileName = strTestPath
        Else
            ' Increase the counter as we have not found a free file yet.
            intFileCounterIndex = intFileCounterIndex + 1
        End If

    Loop Until strFileName <> ""

    ' Found useable filename
    Debug.Print "Free file name: " & strFileName
    GetFileName = strFileName

End Function

The debug lines will help you figure out what is happening if you need to step through the code. Remove them as you see fit. I went a little crazy with the variables but it was to make this as clear as possible.

In Action

My cell O1 contained the string "FileName" without the quotes. Used this sub to call my function and it saved a file.

Sub Testing()
    Dim filename As String: filename = GetFileName(Range("o1"))

    ActiveWorkbook.Worksheets("Sheet1").Range("A1:N24").ExportAsFixedFormat Type:=xlTypePDF, _
                                              filename:=filename, _
                                              Quality:=xlQualityStandard, _
                                              IncludeDocProperties:=True, _
                                              IgnorePrintAreas:=False, _
                                              OpenAfterPublish:=False
End Sub

Where is your code located in reference to everything else? Perhaps you need to make a module if you have not already and move your existing code into there.

Using jQuery Fancybox or Lightbox to display a contact form

Greybox cannot handle forms inside it on its own. It requires a forms plugin. No iframes or external html files needed. Don't forget to download the greybox.css file too as the page misses that bit out.

Kiss Jquery UI goodbye and a lightbox hello. You can get it here.

How to position absolute inside a div?

The problem is described (among other) in this article.

#box is relatively positioned, which makes it part of the "flow" of the page. Your other divs are absolutely positioned, so they are removed from the page's "flow".

Page flow means that the positioning of an element effects other elements in the flow.

In other words, as #box now sees the dom, .a and .b are no longer "inside" #box.

To fix this, you would want to make everything relative, or everything absolute.

One way would be:

.a {
   position:relative;
   margin-top:10px;
   margin-left:10px;
   background-color:red;
   width:210px;
   padding: 5px;
}

Deleting multiple elements from a list

technically, the answer is NO it is not possible to delete two objects AT THE SAME TIME. However, it IS possible to delete two objects in one line of beautiful python.

del (foo['bar'],foo['baz'])

will recusrively delete foo['bar'], then foo['baz']

event Action<> vs event EventHandler<>

On the most part, I'd say follow the pattern. I have deviated from it, but very rarely, and for specific reasons. In the case in point, the biggest issue I'd have is that I'd probably still use an Action<SomeObjectType>, allowing me to add extra properties later, and to use the occasional 2-way property (think Handled, or other feedback-events where the subscriber needs to to set a property on the event object). And once you've started down that line, you might as well use EventHandler<T> for some T.

Default Xmxsize in Java 8 (max heap size)

On my Ubuntu VM, with 1048 MB total RAM, java -XX:+PrintFlagsFinal -version | grep HeapSize printed : uintx MaxHeapSize := 266338304, which is approx 266MB and is 1/4th of my total RAM.

Access: Move to next record until EOF

If you want cmd buttons that loop through the form's records, try adding this code to your cmdNext_Click and cmdPrevious_Click VBA. I have found it works well and copes with BOF / EOF issues:

On Error Resume Next

DoCmd.GoToRecord , , acNext

On Error Goto 0


On Error Resume Next

DoCmd.GoToRecord , , acPrevious

On Error Goto 0

Good luck! PT

How do you copy a record in a SQL table but swap out the unique id of the new row?

Ok, I know that it's an old issue but I post my answer anyway.

I like this solution. I only have to specify the identity column(s).

SELECT * INTO TempTable FROM MyTable_T WHERE id = 1;
ALTER TABLE TempTable DROP COLUMN id;
INSERT INTO MyTable_T SELECT * FROM TempTable;
DROP TABLE TempTable;

The "id"-column is the identity column and that's the only column I have to specify. It's better than the other way around anyway. :-)

I use SQL Server. You may want to use "CREATE TABLE" and "UPDATE TABLE" at row 1 and 2. Hmm, I saw that I did not really give the answer that he wanted. He wanted to copy the id to another column also. But this solution is nice for making a copy with a new auto-id.

I edit my solution with the idéas from Michael Dibbets.

use MyDatabase; 
SELECT * INTO #TempTable FROM [MyTable] WHERE [IndexField] = :id;
ALTER TABLE #TempTable DROP COLUMN [IndexField]; 
INSERT INTO [MyTable] SELECT * FROM #TempTable; 
DROP TABLE #TempTable;

You can drop more than one column by separating them with a ",". The :id should be replaced with the id of the row you want to copy. MyDatabase, MyTable and IndexField should be replaced with your names (of course).

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

There is no difference ...

So principially you could use both (one at a time !-)

But for the sake of readability and for the cleanliness of the html-code I always prefer the window.onload !o]

How to delete columns in pyspark dataframe

Maybe a little bit off topic, but here is the solution using Scala. Make an Array of column names from your oldDataFrame and delete the columns that you want to drop ("colExclude"). Then pass the Array[Column] to select and unpack it.

val columnsToKeep: Array[Column] = oldDataFrame.columns.diff(Array("colExclude"))
                                               .map(x => oldDataFrame.col(x))
val newDataFrame: DataFrame = oldDataFrame.select(columnsToKeep: _*)

Python: Total sum of a list of numbers with the for loop

x=[1,2,3,4,5]
sum=0
for s in range(0,len(x)):
   sum=sum+x[s]
print sum   

Why I can't change directories using "cd"?

You can do following:

#!/bin/bash
cd /your/project/directory
# start another shell and replacing the current
exec /bin/bash

EDIT: This could be 'dotted' as well, to prevent creation of subsequent shells.

Example:

. ./previous_script  (with or without the first line)

Getting the parent div of element

You're looking for parentNode, which Element inherits from Node:

parentDiv = pDoc.parentNode;

Handy References:

  • DOM2 Core specification - well-supported by all major browsers
  • DOM2 HTML specification - bindings between the DOM and HTML
  • DOM3 Core specification - some updates, not all supported by all major browsers
  • HTML5 specification - which now has the DOM/HTML bindings in it

Finding local IP addresses using Python's stdlib

I had to solve the problem "Figure out if an IP address is local or not", and my first thought was to build a list of IPs that were local and then match against it. This is what led me to this question. However, I later realized there is a more straightfoward way to do it: Try to bind on that IP and see if it works.

_local_ip_cache = []
_nonlocal_ip_cache = []
def ip_islocal(ip):
    if ip in _local_ip_cache:
        return True
    if ip in _nonlocal_ip_cache:
        return False
    s = socket.socket()
    try:
        try:
            s.bind((ip, 0))
        except socket.error, e:
            if e.args[0] == errno.EADDRNOTAVAIL:
                _nonlocal_ip_cache.append(ip)
                return False
            else:
                raise
    finally:
        s.close()
    _local_ip_cache.append(ip)
    return True

I know this doesn't answer the question directly, but this should be helpful to anyone trying to solve the related question and who was following the same train of thought. This has the advantage of being a cross-platform solution (I think).

UIView Hide/Show with animation

To fade out:

Objective-C

[UIView animateWithDuration:0.3 animations:^{
    button.alpha = 0;
} completion: ^(BOOL finished) {//creates a variable (BOOL) called "finished" that is set to *YES* when animation IS completed.
    button.hidden = finished;//if animation is finished ("finished" == *YES*), then hidden = "finished" ... (aka hidden = *YES*)
}];

Swift 2

UIView.animateWithDuration(0.3, animations: {
    button.alpha = 0
}) { (finished) in
    button.hidden = finished
}

Swift 3, 4, 5

UIView.animate(withDuration: 0.3, animations: {
    button.alpha = 0
}) { (finished) in
    button.isHidden = finished
}

To fade in:

Objective-C

button.alpha = 0;
button.hidden = NO;
[UIView animateWithDuration:0.3 animations:^{
    button.alpha = 1;
}];

Swift 2

button.alpha = 0
button.hidden = false
UIView.animateWithDuration(0.3) {
    button.alpha = 1
}

Swift 3, 4, 5

button.alpha = 0
button.isHidden = false
UIView.animate(withDuration: 0.3) {
    button.alpha = 1
}

The application may be doing too much work on its main thread

First read the warning. It says more load on main thread. So what you have to do is just run functions with more work in a thread.

How can I make setInterval also work when a tab is inactive in Chrome?

It is quite old question but I encountered the same issue.
If you run your web on chrome, you could read through this post Background Tabs in Chrome 57 .

Basically the interval timer could run if it haven't run out of the timer budget.
The consumption of budget is based on CPU time usage of the task inside timer.
Based on my scenario, I draw video to canvas and transport to WebRTC.
The webrtc video connection would keep updating even the tab is inactive.

However you have to use setInterval instead of requestAnimationFrame.
it is not recommended for UI rendering though.

It would be better to listen visibilityChange event and change render mechenism accordingly.

Besides, you could try @kaan-soral and it should works based on the documentation.

How to redirect user's browser URL to a different page in Nodejs?

For those who (unlike OP) are using the express lib:

http.get('*',function(req,res){  
    res.redirect('http://exmple.com'+req.url)
})

Git diff against a stash

To see the most recent stash:

git stash show -p

To see an arbitrary stash:

git stash show -p stash@{1}

Also, I use git diff to compare the stash with any branch.

You can use:

git diff stash@{0} master

To see all changes compared to branch master.


Or You can use:

git diff --name-only stash@{0} master

To easy find only changed file names.

Writing to a TextBox from another thread?

On your MainForm make a function to set the textbox the checks the InvokeRequired

public void AppendTextBox(string value)
{
    if (InvokeRequired)
    {
        this.Invoke(new Action<string>(AppendTextBox), new object[] {value});
        return;
    }
    ActiveForm.Text += value;
}

although in your static method you can't just call.

WindowsFormsApplication1.Form1.AppendTextBox("hi. ");

you have to have a static reference to the Form1 somewhere, but this isn't really recommended or necessary, can you just make your SampleFunction not static if so then you can just call

AppendTextBox("hi. ");

It will append on a differnt thread and get marshalled to the UI using the Invoke call if required.

Full Sample

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
        new Thread(SampleFunction).Start();
    }

    public void AppendTextBox(string value)
    {
        if (InvokeRequired)
        {
            this.Invoke(new Action<string>(AppendTextBox), new object[] {value});
            return;
        }
        textBox1.Text += value;
    }

    void SampleFunction()
    {
        // Gets executed on a seperate thread and 
        // doesn't block the UI while sleeping
        for(int i = 0; i<5; i++)
        {
            AppendTextBox("hi.  ");
            Thread.Sleep(1000);
        }
    }
}

Add an object to a python list

while you should show how your code looks like that gives the problem, i think this scenario is very common. See copy/deepcopy