Programs & Examples On #Msbuildextensionpack

The MSBuild Extension Pack is an open source collection of tasks that can be plugged into the Microsoft build automation system.

Why is quicksort better than mergesort?

"and yet most people use Quicksort instead of Mergesort. Why is that?"

One psychological reason that has not been given is simply that Quicksort is more cleverly named. ie good marketing.

Yes, Quicksort with triple partioning is probably one of the best general purpose sort algorithms, but theres no getting over the fact that "Quick" sort sounds much more powerful than "Merge" sort.

Can I add background color only for padding?

This would be a proper CSS solution which works for IE8/9 as well (IE8 with html5shiv ofcourse): codepen

nav {
  margin:0px auto;
  height:50px;
  background-color:gray;
  padding:10px;
  border:2px solid red;
  position: relative;
  color: white;
  z-index: 1;
}

nav:after {
  content: '';
  background: black;
  display: block;
  position: absolute;
  margin: 10px;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: -1;
}

How to style a checkbox using CSS

Simple to implement and easily customizable solution

After a lot of search and testing I got this solution which is simple to implement and easier to customize. In this solution:

  1. You don't need external libraries and files
  2. You don't need to add extra HTML in your page
  3. You don't need to change checkbox names and id

Simple put the flowing CSS at the top of your page and all checkboxes style will change like this:

Enter image description here

_x000D_
_x000D_
input[type=checkbox] {
  transform: scale(1.5);
}

input[type=checkbox] {
  width: 30px;
  height: 30px;
  margin-right: 8px;
  cursor: pointer;
  font-size: 17px;
  visibility: hidden;
}

input[type=checkbox]:after {
  content: " ";
  background-color: #fff;
  display: inline-block;
  margin-left: 10px;
  padding-bottom: 5px;
  color: #00BFF0;
  width: 22px;
  height: 25px;
  visibility: visible;
  border: 1px solid #00BFF0;
  padding-left: 3px;
  border-radius: 5px;
}

input[type=checkbox]:checked:after {
  content: "\2714";
  padding: -5px;
  font-weight: bold;
}
_x000D_
<input type="checkbox" id="checkbox1" />
<label for="checkbox1">Checkbox</label>
_x000D_
_x000D_
_x000D_

How to construct a set out of list items in python?

One general way to construct set in iterative way like this:

aset = {e for e in alist}

SQL: How to properly check if a record exists

I would prefer not use Count function at all:

IF [NOT] EXISTS ( SELECT 1 FROM MyTable WHERE ... )
     <do smth>

For example if you want to check if user exists before inserting it into the database the query can look like this:

IF NOT EXISTS ( SELECT 1 FROM Users WHERE FirstName = 'John' AND LastName = 'Smith' )
BEGIN
    INSERT INTO Users (FirstName, LastName) VALUES ('John', 'Smith')
END

Get form data in ReactJS

If all your inputs / textarea have a name, then you can filter all from event.target:

onSubmit(event){
  const fields = Array.prototype.slice.call(event.target)
      .filter(el => el.name)
      .reduce((form, el) => ({
        ...form,
        [el.name]: el.value,
      }), {})
}

Totally uncontrolled form without onChange methods, value, defaultValue...

How can I print out all possible letter combinations a given phone number can represent?

I rewrote the latest answer to this (referred above) , from C to Java. I also included the support for 0 and 1 (as 0 and 1) because numbers such as 555-5055 weren't working at all with the above code.

Here it is. Some comments are preserved.

public static void printPhoneWords(int[] number) {
    char[] output = new char[number.length];
    printWordsUtil(number,0,output);
}

static String[] phoneKeys= new String[]{"0", "1", "ABC", "DEF", "GHI", "JKL",
               "MNO", "PQRS", "TUV", "WXYZ"};
private static void printWordsUtil(int[] number, int curDigIndex, char[] output) {
    // Base case, if current output word is done
    if (curDigIndex == output.length) {
        System.out.print(String.valueOf(output) + " "); 
        return;
    }

      // Try all 3-4 possible characters for the current digit in number[]
      // and recurse for the remaining digits

    char curPhoneKey[] = phoneKeys[number[curDigIndex]].toCharArray();
    for (int i = 0; i< curPhoneKey.length ; i++) {
        output[curDigIndex] = curPhoneKey[i];
        printWordsUtil(number, curDigIndex+1, output);
        if (number[curDigIndex] <= 1) // for 0 or 1
            return;
    }
}

public static void main(String[] args) {
    int number[] = {2, 3, 4};
    printPhoneWords(number);
    System.out.println();
}

Java - ignore exception and continue

You could catch the NullPointerException explicitly and ignore it - though its generally not recommended. You should not, however, ignore all exceptions as you're currently doing.

UserInfo ui = new UserInfo();
try {
    DirectoryUser du = LDAPService.findUser(username);
    if (du!=null) {
       ui.setUserInfo(du.getUserInfo());
    }
} catch (NullPointerException npe) {
    // Lulz @ your NPE
    Logger.log("No user info for " +username+ ", will find some way to cope");
}

How to check if element exists using a lambda expression?

Try to use anyMatch of Lambda Expression. It is much better approach.

 boolean idExists = tabPane.getTabs().stream()
            .anyMatch(t -> t.getId().equals(idToCheck));

Using "If cell contains" in VBA excel

Requirement:
Find a cell containing the word TOTAL then to enter a dash in the cell below it.

Solution: This solution uses the Find method of the Range object, as it seems appropriate to use it rather than brute force (For…Next loop). For explanation and details about the method see Range.Find method (Excel)

Implementation:
In order to provide flexibility the Find method is wrapped in this function:

Function Range_ƒFind_Action(sWhat As String, rTrg As Range) As Boolean

Where:
sWhat: contains the string to search for
rTrg: is the range to be searched

The function returns True if any match is found, otherwise it returns False

Additionally, every time the function finds a match it passes the resulting range to the procedure Range_Find_Action to execute the required action, (i.e. "enter a dash in the cell below it"). The "required action" is in a separated procedure to allow for customization and flexibility.

This is how the function is called:

This test is searching for "total" to show the effect of the MatchCase:=False. The match can be made case sensitive by changing it to MatchCase:=True

Sub Range_Find_Action_TEST()
Dim sWhat As String, rTrg As Range
Dim sMsgbdy As String
    sWhat = "total"                                             'String to search for (update as required)
    Rem Set rTrg = ThisWorkbook.Worksheets("Sht(0)").UsedRange  'Range to Search (use this to search all used cells)
    Set rTrg = ThisWorkbook.Worksheets("Sht(0)").Rows(6)        'Range to Search (update as required)
    sMsgbdy = IIf(Range_ƒFind_Action(sWhat, rTrg), _
        "Cells found were updated successfully", _
        "No cells were found.")
    MsgBox sMsgbdy, vbInformation, "Range_ƒFind_Action"
    End Sub

This is the Find function

Function Range_ƒFind_Action(sWhat As String, rTrg As Range) As Boolean
Dim rCll As Range, s1st As String
    With rTrg

        Rem Set First Cell Found
        Set rCll = .Find(What:=sWhat, After:=.Cells(1), _
            LookIn:=xlFormulas, LookAt:=xlPart, _
            SearchOrder:=xlByRows, SearchDirection:=xlNext, _
            MatchCase:=False, SearchFormat:=False)

        Rem Validate First Cell
        If rCll Is Nothing Then Exit Function
        s1st = rCll.Address

        Rem Perform Action
        Call Range_Find_Action(rCll)

        Do
            Rem Find Other Cells
            Set rCll = .FindNext(After:=rCll)
            Rem Validate Cell vs 1st Cell
            If rCll.Address <> s1st Then Call Range_Find_Action(rCll)

        Loop Until rCll.Address = s1st

    End With

    Rem Set Results
    Range_ƒFind_Action = True

    End Function

This is the Action procedure

Sub Range_Find_Action(rCll)
    rCll.Offset(1).Value2 = Chr(167)    'Update as required - Using `§` instead of "-" for visibilty purposes
    End Sub

enter image description here

Remove tracking branches no longer on remote

This Below Commands Solved My problem.

// To Delete Branch Locally
git branch -d localBranchName


// To Delete Branch Remotely
git push origin --delete remoteBranchName

How do I install g++ on MacOS X?

Installing XCode requires:

  • Enrolling on the Apple website (not fun)
  • Downloading a 4.7G installer

To install g++ *WITHOUT* having to download the MASSIVE 4.7G xCode install, try this package:

https://github.com/kennethreitz/osx-gcc-installer

The DMG files linked on that page are ~270M and much quicker to install. This was perfect for me, getting homebrew up and running with a minimum of hassle.

The github project itself is basically a script that repackages just the critical chunks of xCode for distribution. In order to run that script and build the DMG files, you'd need to already have an XCode install, which would kind of defeat the point, so the pre-built DMG files are hosted on the project page.

installing JDK8 on Windows XP - advapi32.dll error

This happens because Oracle dropped support for Windows XP (which doesn't have RegDeleteKeyExA used by the installer in its ADVAPI32.DLL by the way) as described in http://mail.openjdk.java.net/pipermail/openjfx-dev/2013-July/009005.html. Yet while the official support for XP has ended, the Java binaries are still (as of Java 8u20 EA b05 at least) XP-compatible - only the installer isn't...

Because of that, the solution is actually quite easy:

  1. get 7-Zip (or any other good unpacker), unpack the distribution .exe manually, it has one .zip file inside of it (tools.zip), extract it too,

  2. use unpack200 from JDK8 to unpack all .pack files to .jar files (older unpacks won't work properly); JAVA_HOME environment variable should be set to your Java unpack root, e.g. "C:\Program Files\Java\jdk8" - you can specify it implicitly by e.g.

    SET JAVA_HOME=C:\Program Files\Java\jdk8
    
    • Unpack all files with a single command (in batch file):

      FOR /R %%f IN (*.pack) DO "%JAVA_HOME%\bin\unpack200.exe" -r -v "%%f" "%%~pf%%~nf.jar"
      
    • Unpack all files with a single command (command line from JRE root):

      FOR /R %f IN (*.pack) DO "bin\unpack200.exe" -r -v "%f" "%~pf%~nf.jar"
      
    • Unpack by manually locating the files and unpacking them one-by-one:

      %JAVA_HOME%\bin\unpack200 -r packname.pack packname.jar
      

    where packname is for example rt

  3. point the tool you want to use (e.g. Netbeans) to the %JAVA_HOME% and you're good to go.

Note: you probably shouldn't do this just to use Java 8 in your web browser or for any similar reason (installing JRE 8 comes to mind); security flaws in early updates of major Java version releases are (mind me) legendary, and adding to that no real support for neither XP nor Java 8 on XP only makes matters much worse. Not to mention you usually don't need Java in your browser (see e.g. http://nakedsecurity.sophos.com/2013/01/15/disable-java-browsers-homeland-security/ - the topic is already covered on many pages, just Google it if you require further info). In any case, AFAIK the only thing required to apply this procedure to JRE is to change some of the paths specified above from \bin\ to \lib\ (the file placement in installer directory tree is a bit different) - yet I strongly advise against doing it.

See also: How can I get the latest JRE / JDK as a zip file rather than EXE or MSI installer?, JRE 1.7 - java version - returns: java/lang/NoClassDefFoundError: java/lang/Object

Paging with Oracle

In the interest of completeness, for people looking for a more modern solution, in Oracle 12c there are some new features including better paging and top handling.

Paging

The paging looks like this:

SELECT *
FROM user
ORDER BY first_name
OFFSET 5 ROWS FETCH NEXT 10 ROWS ONLY;

Top N Records

Getting the top records looks like this:

SELECT *
FROM user
ORDER BY first_name
FETCH FIRST 5 ROWS ONLY

Notice how both the above query examples have ORDER BY clauses. The new commands respect these and are run on the sorted data.

I couldn't find a good Oracle reference page for FETCH or OFFSET but this page has a great overview of these new features.

Performance

As @wweicker points out in the comments below, performance is an issue with the new syntax in 12c. I didn't have a copy of 18c to test if Oracle has since improved it.

Interestingly enough, my actual results were returned slightly quicker the first time I ran the queries on my table (113 million+ rows) for the new method:

  • New method: 0.013 seconds.
  • Old method: 0.107 seconds.

However, as @wweicker mentioned, the explain plan looks much worse for the new method:

  • New method cost: 300,110
  • Old method cost: 30

The new syntax caused a full scan of the index on my column, which was the entire cost. Chances are, things get much worse when limiting on unindexed data.

Let's have a look when including a single unindexed column on the previous dataset:

  • New method time/cost: 189.55 seconds/998,908
  • Old method time/cost: 1.973 seconds/256

Summary: use with caution until Oracle improves this handling. If you have an index to work with, perhaps you can get away with using the new method.

Hopefully I'll have a copy of 18c to play with soon and can update

Why use def main()?

Without the main sentinel, the code would be executed even if the script were imported as a module.

Check date between two other dates spring data jpa

You should take a look the reference documentation. It's well explained.

In your case, I think you cannot use between because you need to pass two parameters

Between - findByStartDateBetween … where x.startDate between ?1 and ?2

In your case take a look to use a combination of LessThan or LessThanEqual with GreaterThan or GreaterThanEqual

  • LessThan/LessThanEqual

LessThan - findByEndLessThan … where x.start< ?1

LessThanEqual findByEndLessThanEqual … where x.start <= ?1

  • GreaterThan/GreaterThanEqual

GreaterThan - findByStartGreaterThan … where x.end> ?1

GreaterThanEqual - findByStartGreaterThanEqual … where x.end>= ?1

You can use the operator And and Or to combine both.

@Resource vs @Autowired

Both @Autowired (or @Inject) and @Resource work equally well. But there is a conceptual difference or a difference in the meaning

  • @Resource means get me a known resource by name. The name is extracted from the name of the annotated setter or field, or it is taken from the name-Parameter.
  • @Inject or @Autowired try to wire in a suitable other component by type.

So, basically these are two quite distinct concepts. Unfortunately the Spring-Implementation of @Resource has a built-in fallback, which kicks in when resolution by-name fails. In this case, it falls back to the @Autowired-kind resolution by-type. While this fallback is convenient, IMHO it causes a lot of confusion, because people are unaware of the conceptual difference and tend to use @Resource for type-based autowiring.

Head and tail in one line

Building on the Python 2 solution from @GarethLatty, the following is a way to get a single line equivalent without intermediate variables in Python 2.

t=iter([1, 1, 2, 3, 5, 8, 13, 21, 34, 55]);h,t = [(h,list(t)) for h in t][0]

If you need it to be exception-proof (i.e. supporting empty list), then add:

t=iter([]);h,t = ([(h,list(t)) for h in t]+[(None,[])])[0]

If you want to do it without the semicolon, use:

h,t = ([(h,list(t)) for t in [iter([1,2,3,4])] for h in t]+[(None,[])])[0]

Detect encoding and make everything UTF-8

You need to test the character set on input since responses can come coded with different encodings.

I force all content been sent into UTF-8 by doing detection and translation using the following function:

function fixRequestCharset()
{
  $ref = array(&$_GET, &$_POST, &$_REQUEST);
  foreach ($ref as &$var)
  {
    foreach ($var as $key => $val)
    {
      $encoding = mb_detect_encoding($var[$key], mb_detect_order(), true);
      if (!$encoding)
        continue;
      if (strcasecmp($encoding, 'UTF-8') != 0)
      {
        $encoding = iconv($encoding, 'UTF-8', $var[$key]);
        if ($encoding === false)
          continue;
        $var[$key] = $encoding;
      }
    }
  }
}

That routine will turn all PHP variables that come from the remote host into UTF-8.

Or ignore the value if the encoding could not be detected or converted.

You can customize it to your needs.

Just invoke it before using the variables.

Android How to adjust layout in Full Screen Mode when softkeyboard is visible

I tried many solutions include Joseph Johnson's and Johan Stuyts's. But as a result I got a white space between content and keyboard on some devices (like Lenovo s820) in all cases. So I made some changes to their codes and finally got working solution.

My idea based on adding margin to top of content when keyboard is showing.

contentContainer.getWindowVisibleDisplayFrame(contentAreaOfWindowBounds);
    int usableHeightNow = contentAreaOfWindowBounds.height();

    if (usableHeightNow != usableHeightPrevious) {

        int difference = usableHeightNow - usableHeightPrevious;

        if (difference < 0 && difference < -150) {
            keyboardShowed = true;
            rootViewLayout.topMargin -= difference + 30;
            rootViewLayout.bottomMargin += 30;
        }
        else if (difference < 0 && difference > -150){
            rootViewLayout.topMargin -= difference + 30;
        }
        else if (difference > 0 && difference > 150) {
            keyboardShowed = false;
            rootViewLayout.topMargin = 0;
            rootViewLayout.bottomMargin = 0;
        }

        rootView.requestLayout();

        Log.e("Bug Workaround", "Difference: " + difference);

        usableHeightPrevious = usableHeightNow;
}

As you can see, I add 30 px to difference because there is a small white space between top of the screen and content zone with margin. And I dont know whence it appears so I decided just make margins smaller and now it works exactly how I needed.

Python No JSON object could be decoded

It seems that you have invalid JSON. In that case, that's totally dependent on the data the server sends you which you have not shown. I would suggest running the response through a JSON validator.

How to set selected index JComboBox by value

for example

enter image description here

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.SwingUtilities;

public class ComboboxExample {

    private JFrame frame = new JFrame("Test");
    private JComboBox comboBox = new JComboBox();

    public ComboboxExample() {
        createGui();
    }

    private void createGui() {
        comboBox.addItem("One");
        comboBox.addItem("Two");
        comboBox.addItem("Three");
        JButton button = new JButton("Show Selected");
        button.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                JOptionPane.showMessageDialog(frame, "Selected item: " + comboBox.getSelectedItem());
                javax.swing.SwingUtilities.invokeLater(new Runnable() {

                    @Override
                    public void run() {
                        comboBox.requestFocus();
                        comboBox.requestFocusInWindow();
                    }
                });
            }
        });
        JButton button1 = new JButton("Append Items");
        button1.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                appendCbItem();
            }
        });
        JButton button2 = new JButton("Reduce Items");
        button2.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                reduceCbItem();
            }
        });
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLayout(new GridLayout(4, 1));
        frame.add(comboBox);
        frame.add(button);
        frame.add(button1);
        frame.add(button2);
        frame.setLocation(200, 200);
        frame.pack();
        frame.setVisible(true);
        selectFirstItem();
    }

    public void appendCbItem() {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                comboBox.addItem("Four");
                comboBox.addItem("Five");
                comboBox.addItem("Six");
                comboBox.setSelectedItem("Six");
                requestCbFocus();
            }
        });
    }

    public void reduceCbItem() {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                comboBox.removeItem("Four");
                comboBox.removeItem("Five");
                comboBox.removeItem("Six");
                selectFirstItem();
            }
        });
    }

    public void selectFirstItem() {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                comboBox.setSelectedIndex(0);
                requestCbFocus();
            }
        });
    }

    public void requestCbFocus() {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                comboBox.requestFocus();
                comboBox.requestFocusInWindow();
            }
        });
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                ComboboxExample comboboxExample = new ComboboxExample();
            }
        });
    }
}

Get the current date and time

DateTimePicker1.value = Format(Date.Now)

Sum up a column from a specific row down

If you don't mind using OFFSET(), which is a volatile function that recalculates everytime a cell is changed, then this is a good solution that is both dynamic and reusable:

=OFFSET($COL:$COL, ROW(), 1, 1048576 - ROW(), 1)

where $COL is the letter of the column you are going to operate upon, and ROW() is the row function that dynamically selects the same row as the cell containing this formula. You could also replace the ROW() function with a static number ($ROW).

=OFFSET($COL:$COL, $ROW, 1, 1048576 - $ROW, 1)

You could further clean up the formula by defining a named constant for the 1048576 as 'maxRows'. This can be done in the 'Define Name' menu of the Formulas tab.

=OFFSET($COL:$COL, $ROW, 1, maxRows - $ROW, 1)

A quick example: to Sum from C6 to the end of column C, you could do:

=SUM(OFFSET(C:C, 6, 1, maxRows - 6, 1))

or =SUM(OFFSET(C:C, ROW(), 1, maxRows - ROW(),1))

how to delete the content of text file without deleting itself

One liner to make truncate operation:

FileChannel.open(Paths.get("/home/user/file/to/truncate"), StandardOpenOption.WRITE).truncate(0).close();

More information available at Java Documentation: https://docs.oracle.com/javase/7/docs/api/java/nio/channels/FileChannel.html

How to use confirm using sweet alert?

I have been having this issue with SweetAlert2 as well. SA2 differs from 1 and puts everything inside the result object. The following above can be accomplished with the following code.

Swal.fire({
    title: 'A cool title',
    icon: 'info',
    confirmButtonText: 'Log in'
  }).then((result) => {
    if (result['isConfirmed']){
      // Put your function here
    }
  })

Everything placed inside the then result will run. Result holds a couple of parameters which can be used to do the trick. Pretty simple technique. Not sure if it works the same on SweetAlert1 but I really wouldn't know why you would choose that one above the newer version.

Why can't Visual Studio find my DLL?

I've experienced same problem with same lib, found a solution here on SO:

Search MSDN for "How to: Set Environment Variables for Projects". (It's Project>Properties>Configuration Properties>Debugging "Environment" and "Merge Environment" properties for those who are in a rush.)

The syntax is NAME=VALUE and macros can be used (for example, $(OutDir)).

For example, to prepend C:\Windows\Temp to the PATH:

PATH=C:\WINDOWS\Temp;%PATH%

Similarly, to append $(TargetDir)\DLLS to the PATH:

PATH=%PATH%;$(TargetDir)\DLLS

(answered by Multicollinearity here: How do I set a path in visual studio?

Getting IPV4 address from a sockaddr structure

Just cast the entire sockaddr structure to a sockaddr_in. Then you can use:

char *ip = inet_ntoa(their_addr.sin_addr)

To retrieve the standard ip representation.

How to read a file in other directory in python

You can't "open" a directory using the open function. This function is meant to be used to open files.

Here, what you want to do is open the file that's in the directory. The first thing you must do is compute this file's path. The os.path.join function will let you do that by joining parts of the path (the directory and the file name):

fpath = os.path.join(direct, "5_1.txt")

You can then open the file:

f = open(fpath)

And read its content:

content = f.read()

Additionally, I believe that on Windows, using open on a directory does return a PermissionDenied exception, although that's not really the case.

Padding or margin value in pixels as integer using jQuery

Parse int

parseInt(canvas.css("margin-left")); 

returns 0 for 0px

How do you follow an HTTP Redirect in Node.js?

Is there a wrapper module on top of the http to more easily handle processing http responses from a node application?

request

Redirection logic in request

Java String declaration

There is a small difference between both.

Second declaration assignates the reference associated to the constant SOMEto the variable str

First declaration creates a new String having for value the value of the constant SOME and assignates its reference to the variable str.

In the first case, a second String has been created having the same value that SOME which implies more inititialization time. As a consequence, you should avoid it. Furthermore, at compile time, all constants SOMEare transformed into the same instance, which uses far less memory.

As a consequence, always prefer second syntax.

How to parse a JSON string to an array using Jackson

I sorted this problem by verifying the json on JSONLint.com and then using Jackson. Below is the code for the same.

 Main Class:-

String jsonStr = "[{\r\n" + "       \"name\": \"John\",\r\n" + "        \"city\": \"Berlin\",\r\n"
                + "         \"cars\": [\r\n" + "            \"FIAT\",\r\n" + "          \"Toyata\"\r\n"
                + "     ],\r\n" + "     \"job\": \"Teacher\"\r\n" + "   },\r\n" + " {\r\n"
                + "     \"name\": \"Mark\",\r\n" + "        \"city\": \"Oslo\",\r\n" + "        \"cars\": [\r\n"
                + "         \"VW\",\r\n" + "            \"Toyata\"\r\n" + "     ],\r\n"
                + "     \"job\": \"Doctor\"\r\n" + "    }\r\n" + "]";

        ObjectMapper mapper = new ObjectMapper();

        MyPojo jsonObj[] = mapper.readValue(jsonStr, MyPojo[].class);

        for (MyPojo itr : jsonObj) {

            System.out.println("Val of getName is: " + itr.getName());
            System.out.println("Val of getCity is: " + itr.getCity());
            System.out.println("Val of getJob is: " + itr.getJob());
            System.out.println("Val of getCars is: " + itr.getCars() + "\n");

        }

POJO:

public class MyPojo {

private List<String> cars = new ArrayList<String>();

private String name;

private String job;

private String city;

public List<String> getCars() {
    return cars;
}

public void setCars(List<String> cars) {
    this.cars = cars;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getJob() {
    return job;
}

public void setJob(String job) {
    this.job = job;
}

public String getCity() {
    return city;
}

public void setCity(String city) {
    this.city = city;
} }

  RESULT:-
         Val of getName is: John
         Val of getCity is: Berlin
         Val of getJob is: Teacher
         Val of getCars is: [FIAT, Toyata]

          Val of getName is: Mark
          Val of getCity is: Oslo
          Val of getJob is: Doctor
          Val of getCars is: [VW, Toyata]

UnsatisfiedDependencyException: Error creating bean with name 'entityManagerFactory'

The MySQL dependency should be like the following syntax in the pom.xml file.

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.21</version>
    </dependency>

Make sure the syntax, groupId, artifactId, Version has included in the dependancy.

How to Maximize window in chrome using webDriver (python)

For MAC or Linux:

ChromeOptions chromeOptions = new ChromeOptions();
chromeOptions.addArguments("--kiosk");
driver = new ChromeDriver(chromeOptions);

For Windows:

ChromeOptions chromeOptions = new ChromeOptions();
chromeOptions.addArguments("--start-maximized");
driver = new ChromeDriver(chromeOptions);

Does Spring Data JPA have any way to count entites using method name resolving?

@Autowired
private UserRepository userRepository;

@RequestMapping("/user/count")
private Long getNumberOfUsers(){
    return userRepository.count();
}

Scroll to the top of the page using JavaScript?

This will work:

window.scrollTo(0, 0);

Create PDF from a list of images

I had the same problem, so I created a python function to unite multiple pictures in one pdf. The code (available from my github page, uses reportlab, and is based on answers from the following links:

Here is example of how to unite images into pdf:

We have folder "D:\pictures" with pictures of types png and jpg, and we want to create file pdf_with_pictures.pdf out of them and save it in the same folder.

outputPdfName = "pdf_with_pictures"
pathToSavePdfTo = "D:\\pictures"
pathToPictures = "D:\\pictures"
splitType = "none"
numberOfEntitiesInOnePdf = 1
listWithImagesExtensions = ["png", "jpg"]
picturesAreInRootFolder = True
nameOfPart = "volume"

unite_pictures_into_pdf(outputPdfName, pathToSavePdfTo, pathToPictures, splitType, numberOfEntitiesInOnePdf, listWithImagesExtensions, picturesAreInRootFolder, nameOfPart)

Importing csv file into R - numeric values read as characters

Whatever algebra you are doing in Excel to create the new column could probably be done more effectively in R.

Please try the following: Read the raw file (before any excel manipulation) into R using read.csv(... stringsAsFactors=FALSE). [If that does not work, please take a look at ?read.table (which read.csv wraps), however there may be some other underlying issue].

For example:

   delim = ","  # or is it "\t" ?
   dec = "."    # or is it "," ?
   myDataFrame <- read.csv("path/to/file.csv", header=TRUE, sep=delim, dec=dec, stringsAsFactors=FALSE)

Then, let's say your numeric columns is column 4

   myDataFrame[, 4]  <- as.numeric(myDataFrame[, 4])  # you can also refer to the column by "itsName"


Lastly, if you need any help with accomplishing in R the same tasks that you've done in Excel, there are plenty of folks here who would be happy to help you out

Resize UIImage and change the size of UIImageView

This is the Swift equivalent for Rajneesh071's answer, using extensions

UIImage {
  func scaleToSize(aSize :CGSize) -> UIImage {
    if (CGSizeEqualToSize(self.size, aSize)) {
      return self
    }

    UIGraphicsBeginImageContextWithOptions(aSize, false, 0.0)
    self.drawInRect(CGRectMake(0.0, 0.0, aSize.width, aSize.height))
    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return image
  }
}

Usage:

let image = UIImage(named: "Icon")
item.icon = image?.scaleToSize(CGSize(width: 30.0, height: 30.0))

Disable vertical sync for glxgears

I found a solution that works in the intel card and in the nvidia card using Bumblebee.

> export vblank_mode=0
glxgears
...
optirun glxgears
...
export vblank_mode=1

Base64 Java encode and decode a string

For Spring Users , Spring Security has a Base64 class in the org.springframework.security.crypto.codec package that can also be used for encoding and decoding of Base64. Ex.

 public static String base64Encode(String token) {
    byte[] encodedBytes = Base64.encode(token.getBytes());
    return new String(encodedBytes, Charset.forName("UTF-8"));
}


public static String base64Decode(String token) {
    byte[] decodedBytes = Base64.decode(token.getBytes());
    return new String(decodedBytes, Charset.forName("UTF-8"));
}

iOS (iPhone, iPad, iPodTouch) view real-time console log terminal

You have three options:

  • Xcode Organizer
  • Jailbroken device with syslogd + openSSH
  • Use dup2 to redirect all STDERR and STDOUT to a file and then "tail -f" that file (this last one is more a simulator thing, since you are stuck with the same problem of tailing a file on the device).

So, to get the 2º one you just need to install syslogd and OpenSSH from Cydia, restart required after to get syslogd going; now just open a ssh session to your device (via terminal or putty on windows), and type "tail -f /var/log/syslog". And there you go, wireless real time system log.

If you would like to try the 3º just search for "dup2" online, it's a system call.

Why does Google prepend while(1); to their JSON responses?

This is to ensure some other site can't do nasty tricks to try to steal your data. For example, by replacing the array constructor, then including this JSON URL via a <script> tag, a malicious third-party site could steal the data from the JSON response. By putting a while(1); at the start, the script will hang instead.

A same-site request using XHR and a separate JSON parser, on the other hand, can easily ignore the while(1); prefix.

How to change color of Android ListView separator line?

Use below code in your xml file

<ListView 
    android:id="@+id/listView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:divider="#000000" 
    android:dividerHeight="1dp">
</ListView> 

Adding the "Clear" Button to an iPhone UITextField

This button is a built-in overlay that is provided by the UITextField class, but as of the iOS 2.2 SDK, there isn't any way to set it via Interface Builder. You have to enable it programmatically.

Add this line of code somewhere (viewDidLoad, for example):

Objective-C

myUITextField.clearButtonMode = UITextFieldViewModeWhileEditing;

Swift 5.0

myUITextField.clearButtonMode = .whileEditing

Purpose of installing Twitter Bootstrap through npm?

If you NPM those modules you can serve them using static redirect.

First install the packages:

npm install jquery
npm install bootstrap

Then on the server.js:

var express = require('express');
var app = express();

// prepare server
app.use('/api', api); // redirect API calls
app.use('/', express.static(__dirname + '/www')); // redirect root
app.use('/js', express.static(__dirname + '/node_modules/bootstrap/dist/js')); // redirect bootstrap JS
app.use('/js', express.static(__dirname + '/node_modules/jquery/dist')); // redirect JS jQuery
app.use('/css', express.static(__dirname + '/node_modules/bootstrap/dist/css')); // redirect CSS bootstrap

Then, finally, at the .html:

<link rel="stylesheet" href="/css/bootstrap.min.css">
<script src="/js/jquery.min.js"></script>
<script src="/js/bootstrap.min.js"></script>

I would not serve pages directly from the folder where your server.js file is (which is usually the same as node_modules) as proposed by timetowonder, that way people can access your server.js file.

Of course you can simply download and copy & paste on your folder, but with NPM you can simply update when needed... easier, I think.

Http Get using Android HttpURLConnection

Here is a complete AsyncTask class

public class GetMethodDemo extends AsyncTask<String , Void ,String> {
    String server_response;

    @Override
    protected String doInBackground(String... strings) {

        URL url;
        HttpURLConnection urlConnection = null;

        try {
            url = new URL(strings[0]);
            urlConnection = (HttpURLConnection) url.openConnection();

            int responseCode = urlConnection.getResponseCode();

            if(responseCode == HttpURLConnection.HTTP_OK){
                server_response = readStream(urlConnection.getInputStream());
                Log.v("CatalogClient", server_response);
            }

        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return null;
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);

        Log.e("Response", "" + server_response);


    }
}

// Converting InputStream to String

private String readStream(InputStream in) {
        BufferedReader reader = null;
        StringBuffer response = new StringBuffer();
        try {
            reader = new BufferedReader(new InputStreamReader(in));
            String line = "";
            while ((line = reader.readLine()) != null) {
                response.append(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return response.toString();
    }

To Call this AsyncTask class

new GetMethodDemo().execute("your web-service url");

You need to use a Theme.AppCompat theme (or descendant) with this activity

You have many solutions to that error.

  1. You should use Activity or FragmentActivity instead of ActionbarActivity or AppCompatActivity

  2. If you want use ActionbarActivity or AppCompatActivity, you should change in styles.xml Theme.Holo.xxxx to Theme.AppCompat.Light (if necessary add to DarkActionbar)

If you don't need advanced attributes about action bar or AppCompat you don't need to use Actionbar or AppCompat.

Best way to check if column returns a null value (from database to .net application)

Just use DataRow.IsNull. It has overrides accepting a column index, a column name, or a DataColumn object as parameters.

Example using the column index:

if (table.rows[0].IsNull(0))
{
    //Whatever I want to do
}

And although the function is called IsNull it really compares with DbNull (which is exactly what you need).


What if I want to check for DbNull but I don't have a DataRow? Use Convert.IsDBNull.

How can I make a div stick to the top of the screen once it's been scrolled to?

I used some of the work above to create this tech. I improved it a bit and thought I would share my work. Hope this helps.

jsfiddle Code

function scrollErrorMessageToTop() {
    var flash_error = jQuery('#flash_error');
    var flash_position = flash_error.position();

    function lockErrorMessageToTop() {
        var place_holder = jQuery("#place_holder");
        if (jQuery(this).scrollTop() > flash_position.top && flash_error.attr("position") != "fixed") {
            flash_error.css({
                'position': 'fixed',
                'top': "0px",
                "width": flash_error.width(),
                "z-index": "1"
            });
            place_holder.css("display", "");
        } else {
            flash_error.css('position', '');
            place_holder.css("display", "none");
        }

    }
    if (flash_error.length > 0) {
        lockErrorMessageToTop();

        jQuery("#flash_error").after(jQuery("<div id='place_holder'>"));
        var place_holder = jQuery("#place_holder");
        place_holder.css({
            "height": flash_error.height(),
            "display": "none"
        });
        jQuery(window).scroll(function(e) {
            lockErrorMessageToTop();
        });
    }
}
scrollErrorMessageToTop();?

This is a little bit more dynamic of a way to do the scroll. It does need some work and I will at some point turn this into a pluging but but this is what I came up with after hour of work.

Extract a subset of a dataframe based on a condition involving a field

Just to extend the answer above you can also index your columns rather than specifying the column names which can also be useful depending on what you're doing. Given that your location is the first field it would look like this:

    bar <- foo[foo[ ,1] == "there", ]

This is useful because you can perform operations on your column value, like looping over specific columns (and you can do the same by indexing row numbers too).

This is also useful if you need to perform some operation on more than one column because you can then specify a range of columns:

    foo[foo[ ,c(1:N)], ]

Or specific columns, as you would expect.

    foo[foo[ ,c(1,5,9)], ]

Force an Android activity to always use landscape mode

For Android 4.0 (Ice Cream Sandwich) and later, I needed to add these, besides the landscape value.

android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"

Using only keyboardHidden|orientation would still result in memory leaks and recreation of my activities when pressing the power button.

centos: Another MySQL daemon already running with the same unix socket

TL;DR:

Run this as root and you'll be all set:

rm $(grep socket /etc/my.cnf | cut -d= -f2)  && service mysqld start

Longer version:

You can find the location of MySQL's socket file by manually poking around in /etc/my.conf, or just by using

grep socket /etc/my.cnf | cut -d= -f2

It is likely to be /var/lib/mysql/mysql.sock. Then (as root, of course, or with sudo prepended) remove that file:

rm /var/lib/mysql/mysql.sock

Then start the MySQL daemon:

service mysqld start

Removing mysqld will not address the problem at all. The problem is that CentOS & RedHat do not clean up the sock file after a crash, so you have to do it yourself. Avoiding powering off your system is (of course) also advised, but sometimes you can't avoid it, so this procedure will solve the problem.

Delete with Join in MySQL

One solution is to use subquery

DELETE FROM posts WHERE post_id in (SELECT post_id FROM posts p
INNER JOIN projects prj ON p.project_id = prj.project_id 
INNER JOIN clients c on prj.client_id = c.client_id WHERE c.client_id = :client_id 
);

The subquery returns the ID that need to be deleted; all three tables are connected using joins and only those records are deleted that meets the filter condition (in yours case i.e. client_id in the where clause).

How to check if a string is a number?

rewrite the whole function as below:

bool IsValidNumber(char * string)
{
   for(int i = 0; i < strlen( string ); i ++)
   {
      //ASCII value of 0 = 48, 9 = 57. So if value is outside of numeric range then fail
      //Checking for negative sign "-" could be added: ASCII value 45.
      if (string[i] < 48 || string[i] > 57)
         return FALSE;
   }

   return TRUE;
}

Bash: Strip trailing linebreak from output

printf already crops the trailing newline for you:

$ printf '%s' $(wc -l < log.txt)

Detail:

  • printf will print your content in place of the %s string place holder.
  • If you do not tell it to print a newline (%s\n), it won't.

React / JSX Dynamic Component Name

Suspose we wish to access various views with dynamic component loading.The following code gives a working example of how to accomplish this by using a string parsed from the search string of a url.

Lets assume we want to access a page 'snozberrys' with two unique views using these url paths:

'http://localhost:3000/snozberrys?aComponent'

and

'http://localhost:3000/snozberrys?bComponent'

we define our view's controller like this:

import React, { Component } from 'react';
import ReactDOM from 'react-dom'
import {
  BrowserRouter as Router,
  Route
} from 'react-router-dom'
import AComponent from './AComponent.js';
import CoBComponent sole from './BComponent.js';

const views = {
  aComponent: <AComponent />,
  console: <BComponent />
}

const View = (props) => {
  let name = props.location.search.substr(1);
  let view = views[name];
  if(view == null) throw "View '" + name + "' is undefined";
  return view;
}

class ViewManager extends Component {
  render() {
    return (
      <Router>
        <div>
          <Route path='/' component={View}/>
        </div>
      </Router>
    );
  }
}

export default ViewManager

ReactDOM.render(<ViewManager />, document.getElementById('root'));

AngularJS not detecting Access-Control-Allow-Origin header?

CROS needs to be resolved from server side.

Create Filters as per requirement to allow access and add filters in web.xml

Example using spring:

Filter Class:

@Component
public class SimpleFilter implements Filter {

@Override
public void init(FilterConfig arg0) throws ServletException {}

@Override
public void doFilter(ServletRequest req, ServletResponse resp,
                     FilterChain chain) throws IOException, ServletException {

    HttpServletResponse response=(HttpServletResponse) resp;

    response.setHeader("Access-Control-Allow-Origin", "*");
    response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
    response.setHeader("Access-Control-Max-Age", "3600");
    response.setHeader("Access-Control-Allow-Headers", "x-requested-with");

    chain.doFilter(req, resp);
}

@Override
public void destroy() {}

}

Web.xml:

<filter>
    <filter-name>simpleCORSFilter</filter-name>
    <filter-class>
        com.abc.web.controller.general.SimpleFilter
    </filter-class>
</filter>
<filter-mapping>
    <filter-name>simpleCORSFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

Android dependency has different version for the compile and runtime

The answer for me was to also add this to my build.gradle file:

configurations.all {
  resolutionStrategy.eachDependency { details ->
      if (details.requested.group == 'com.android.support'
              && !details.requested.name.contains('multidex') ) {
          details.useVersion "26.1.0"
      }
  }
}

In my case, it was nessisary to enclose the resolution strategy in a configurations.all { .. } block. I placed the configurations.all block directly into my app/build.gradle file (ie configurations.all was not nested in anything else)

jQuery - How to dynamically add a validation rule

In case you want jquery validate to auto pick validations on dynamically added items, you can simply remove and add validation on the whole form like below

//remove validations on entire form
$("#yourFormId")
    .removeData("validator")
    .removeData("unobtrusiveValidation");

//Simply add it again
$.validator
    .unobtrusive
    .parse("#yourFormId");

Why use argparse rather than optparse?

As of python 2.7, optparse is deprecated, and will hopefully go away in the future.

argparse is better for all the reasons listed on its original page (https://code.google.com/archive/p/argparse/):

  • handling positional arguments
  • supporting sub-commands
  • allowing alternative option prefixes like + and /
  • handling zero-or-more and one-or-more style arguments
  • producing more informative usage messages
  • providing a much simpler interface for custom types and actions

More information is also in PEP 389, which is the vehicle by which argparse made it into the standard library.

How can I generate a tsconfig.json file?

this worked for me:

tsc --init

How to run a PowerShell script from a batch file

Small sample test.cmd

<# :
  @echo off
    powershell /nologo /noprofile /command ^
         "&{[ScriptBlock]::Create((cat """%~f0""") -join [Char[]]10).Invoke(@(&{$args}%*))}"
  exit /b
#>
Write-Host Hello, $args[0] -fo Green
#You programm...

Postgres: How to convert a json string to text?

In 9.4.4 using the #>> operator works for me:

select to_json('test'::text) #>> '{}';

To use with a table column:

select jsoncol #>> '{}' from mytable;

SQLAlchemy default DateTime

As per PostgreSQL documentation, https://www.postgresql.org/docs/9.6/static/functions-datetime.html

now, CURRENT_TIMESTAMP, LOCALTIMESTAMP return the time of transaction.

This is considered a feature: the intent is to allow a single transaction to have a consistent notion of the "current" time, so that multiple modifications within the same transaction bear the same time stamp.

You might want to use statement_timestamp or clock_timestamp if you don't want transaction timestamp.

statement_timestamp()

returns the start time of the current statement (more specifically, the time of receipt of the latest command message from the client). statement_timestamp

clock_timestamp()

returns the actual current time, and therefore its value changes even within a single SQL command.

Why does corrcoef return a matrix?

corrcoef returns the normalised covariance matrix.

The covariance matrix is the matrix

Cov( X, X )    Cov( X, Y )

Cov( Y, X )    Cov( Y, Y )

Normalised, this will yield the matrix:

Corr( X, X )    Corr( X, Y )

Corr( Y, X )    Corr( Y, Y )

correlation1[0, 0 ] is the correlation between Strategy1Returns and itself, which must be 1. You just want correlation1[ 0, 1 ].

How do I solve the INSTALL_FAILED_DEXOPT error?

I needed to disable Instant Run to fix the issue. To disable Instant Run on OS X, go to Android Studio > Preferences > Build, Execution, Deployment > Instant Run then remove the tick from Enable Instant Run to hot swap code/resource changes on deploy (default enabled).

Run a PHP file in a cron job using CPanel

>/dev/null stops cron from sending mails.

actually to my mind it's better to make php script itself to care about it's logging rather than just outputting something to cron

Local Storage vs Cookies

With localStorage, web applications can store data locally within the user's browser. Before HTML5, application data had to be stored in cookies, included in every server request. Large amounts of data can be stored locally, without affecting website performance. Although localStorage is more modern, there are some pros and cons to both techniques.

Cookies

Pros

  • Legacy support (it's been around forever)
  • Persistent data
  • Expiration dates

Cons

  • Each domain stores all its cookies in a single string, which can make parsing data difficult
  • Data is unencrypted, which becomes an issue because... ... though small in size, cookies are sent with every HTTP request Limited size (4KB)
  • SQL injection can be performed from a cookie

Local storage

Pros

  • Support by most modern browsers
  • Persistent data that is stored directly in the browser
  • Same-origin rules apply to local storage data
  • Is not sent with every HTTP request
  • ~5MB storage per domain (that's 5120KB)

Cons

  • Not supported by anything before: IE 8, Firefox 3.5, Safari 4, Chrome 4, Opera 10.5, iOS 2.0, Android 2.0
  • If the server needs stored client information you purposely have to send it.

localStorage usage is almost identical with the session one. They have pretty much exact methods, so switching from session to localStorage is really child's play. However, if stored data is really crucial for your application, you will probably use cookies as a backup in case localStorage is not available. If you want to check browser support for localStorage, all you have to do is run this simple script:

/* 
* function body that test if storage is available
* returns true if localStorage is available and false if it's not
*/
function lsTest(){
    var test = 'test';
    try {
        localStorage.setItem(test, test);
        localStorage.removeItem(test);
        return true;
    } catch(e) {
        return false;
    }
}

/* 
* execute Test and run our custom script 
*/
if(lsTest()) {
    // window.sessionStorage.setItem(name, 1); // session and storage methods are very similar
    window.localStorage.setItem(name, 1);
    console.log('localStorage where used'); // log
} else {
    document.cookie="name=1; expires=Mon, 28 Mar 2016 12:00:00 UTC";
    console.log('Cookie where used'); // log
}

"localStorage values on Secure (SSL) pages are isolated" as someone noticed keep in mind that localStorage will not be available if you switch from 'http' to 'https' secured protocol, where the cookie will still be accesible. This is kind of important to be aware of if you work with secure protocols.

Failed: Error in connection establishment: net::ERR_CONNECTION_REFUSED

In my case the answer is pretty simple. Please check carefully the hardcoded url port: it is 8080. For some reason the value has changed to: for example 3030.

Just refresh the port in your ajax url string to the appropriate one.

conn = new WebSocket('ws://localhost:3030'); //should solve the issue

How can I get the current page name in WordPress?

This seems to be the easiest to use:

<?php single_post_title(); ?>

Conditional formatting using AND() function

You can use a much simpler formula. I just created a new workbook to test it.

Column A = Date1 | Column B = Date2 | Column C = Date3

Highlight Column A and enter the conditional formatting formula:

=AND(A1>B1,A1<C1)

Javascript (+) sign concatenates instead of giving sum of variables

Another alternative could be using:

divID = "question-" + (i - -1);

Subtracting a negative is the same as adding, and a minus cannot be used for concatenation

Edit: Forgot that brackets are still necessary since code is read from left to right.

How to hide navigation bar permanently in android activity?

I think the blow code will help you, and add those code before setContentView()

getWindow().setFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS, WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);

Add those code behind setContentView() getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE);

Byte[] to ASCII

You can use:

System.Text.Encoding.ASCII.GetString(buf);

But sometimes you will get a weird number instead of the string you want. In that case, your original string may have some hexadecimal character when you see it. If it's the case, you may want to try this:

System.Text.Encoding.UTF8.GetString(buf);

Or as a last resort:

System.Text.Encoding.Default.GetString(bytearray);

html button to send email

You can not directly send an email with a HTML form. You can however send the form to your web server and then generate the email with a server side program written in e.g. PHP.

The other solution is to create a link as you did with the "mailto:". This will open the local email program from the user. And he/she can then send the pre-populated email.

When you decided how you wanted to do it you can ask another (more specific) question on this site. (Or you can search for a solution somewhere on the internet.)

Retrieve column names from java.sql.ResultSet

I know, this question is already answered but probably somebody like me needs to access a column name from DatabaseMetaData by label instead of index:

ResultSet resultSet = null;
DatabaseMetaData metaData = null;

    try {
        metaData  = connection.getMetaData();
        resultSet = metaData.getColumns(null, null, tableName, null);

        while (resultSet.next()){
            String name = resultSet.getString("COLUMN_NAME");
        }
    }

How do I put an image into my picturebox using ImageLocation?

if you provide a bad path or a broken link, if the compiler cannot find the image, the picture box would display an X icon on its body.

PictureBox picture = new PictureBox
        {
            Name = "pictureBox",
            Size = new Size(100, 50),
            Location = new Point(14, 17),
            Image = Image.FromFile(@"c:\Images\test.jpg"),
            SizeMode = PictureBoxSizeMode.CenterImage
        };
p.Controls.Add(picture);

OR

PictureBox picture = new PictureBox
        {
            Name = "pictureBox",
            Size = new Size(100, 50),
            Location = new Point(14, 17),
            ImageLocation = @"c:\Images\test.jpg",
            SizeMode = PictureBoxSizeMode.CenterImage
        };
p.Controls.Add(picture);

i'm not sure where you put images in your folder structure but you can find the path as bellow

 picture.ImageLocation = Path.Combine(System.Windows.Forms.Application.StartupPath, "Resources\Images\1.jpg");

How to remove ASP.Net MVC Default HTTP Headers?

You can also remove them by adding code to your global.asax file:

 protected void Application_PreSendRequestHeaders(object sender, EventArgs e)
 {
   HttpContext.Current.Response.Headers.Remove("X-Powered-By");
   HttpContext.Current.Response.Headers.Remove("X-AspNet-Version");
   HttpContext.Current.Response.Headers.Remove("X-AspNetMvc-Version");
   HttpContext.Current.Response.Headers.Remove("Server");
 }

How do I copy directories recursively with gulp?

Turns out that to copy a complete directory structure gulp needs to be provided with a base for your gulp.src() method.

So gulp.src( [ files ], { "base" : "." }) can be used in the structure above to copy all the directories recursively.

If, like me, you may forget this then try:

gulp.copy=function(src,dest){
    return gulp.src(src, {base:"."})
        .pipe(gulp.dest(dest));
};

What is the difference between the GNU Makefile variable assignments =, ?=, := and +=?

I suggest you do some experiments using "make". Here is a simple demo, showing the difference between = and :=.

/* Filename: Makefile*/
x := foo
y := $(x) bar
x := later

a = foo
b = $(a) bar
a = later

test:
    @echo x - $(x)
    @echo y - $(y)
    @echo a - $(a)
    @echo b - $(b)

make test prints:

x - later
y - foo bar
a - later
b - later bar

Check more elaborate explanation here

How can I properly use a PDO object for a parameterized SELECT query

A litle bit complete answer is here with all ready for use:

    $sql = "SELECT `username` FROM `users` WHERE `id` = :id";
    $q = $dbh->prepare($sql);
    $q->execute(array(':id' => "4"));
    $done= $q->fetch();

 echo $done[0];

Here $dbh is PDO db connecter, and based on id from table users we've get the username using fetch();

I hope this help someone, Enjoy!

Evaluate if list is empty JSTL

empty is an operator:

The empty operator is a prefix operation that can be used to determine whether a value is null or empty.

<c:if test="${empty myObject.featuresList}">

Sanitizing user input before adding it to the DOM in Javascript

You could use a simple regular expression to assert that the id only contains allowed characters, like so:

if(id.match(/^[0-9a-zA-Z]{1,16}$/)){
    //The id is fine
}
else{
    //The id is illegal
}

My example allows only alphanumerical characters, and strings of length 1 to 16, you should change it to match the type of ids that you use.

By the way, at line 6, the value property is missing a pair of quotes, an easy mistake to make when you quote on two levels.

I can't see your actual data flow, depending on context this check may not at all be needed, or it may not be enough. In order to make a proper security review we would need more information.

In general, about built in escape or sanitize functions, don't trust them blindly. You need to know exactly what they do, and you need to establish that that is actually what you need. If it is not what you need, the code your own, most of the time a simple whitelisting regex like the one I gave you works just fine.

Extract names of objects from list

Making a small tweak to the inside function and using lapply on an index instead of the actual list itself gets this doing what you want

x <- c("yes", "no", "maybe", "no", "no", "yes")
y <- c("red", "blue", "green", "green", "orange")
list.xy <- list(x=x, y=y)

WORD.C <- function(WORDS){
  require(wordcloud)

  L2 <- lapply(WORDS, function(x) as.data.frame(table(x), stringsAsFactors = FALSE))

  # Takes a dataframe and the text you want to display
  FUN <- function(X, text){
    windows() 
    wordcloud(X[, 1], X[, 2], min.freq=1)
    mtext(text, 3, padj=-4.5, col="red")  #what I'm trying that isn't working
  }

  # Now creates the sequence 1,...,length(L2)
  # Loops over that and then create an anonymous function
  # to send in the information you want to use.
  lapply(seq_along(L2), function(i){FUN(L2[[i]], names(L2)[i])})

  # Since you asked about loops
  # you could use i in seq_along(L2) 
  # instead of 1:length(L2) if you wanted to
  #for(i in 1:length(L2)){
  #  FUN(L2[[i]], names(L2)[i])
  #}
}

WORD.C(list.xy)

How to count total lines changed by a specific author in a Git repository?

git-fame

https://github.com/oleander/git-fame-rb

This is a nice tool to get the count for all authors at once, including commit and modified files count:

sudo apt-get install ruby-dev
sudo gem install git_fame
cd /path/to/gitdir && git fame

There is also Python version at https://github.com/casperdcl/git-fame (mentioned by @fracz):

sudo apt-get install python-pip python-dev build-essential 
pip install --user git-fame
cd /path/to/gitdir && git fame

Sample output:

Total number of files: 2,053
Total number of lines: 63,132
Total number of commits: 4,330

+------------------------+--------+---------+-------+--------------------+
| name                   | loc    | commits | files | percent            |
+------------------------+--------+---------+-------+--------------------+
| Johan Sørensen         | 22,272 | 1,814   | 414   | 35.3 / 41.9 / 20.2 |
| Marius Mathiesen       | 10,387 | 502     | 229   | 16.5 / 11.6 / 11.2 |
| Jesper Josefsson       | 9,689  | 519     | 191   | 15.3 / 12.0 / 9.3  |
| Ole Martin Kristiansen | 6,632  | 24      | 60    | 10.5 / 0.6 / 2.9   |
| Linus Oleander         | 5,769  | 705     | 277   | 9.1 / 16.3 / 13.5  |
| Fabio Akita            | 2,122  | 24      | 60    | 3.4 / 0.6 / 2.9    |
| August Lilleaas        | 1,572  | 123     | 63    | 2.5 / 2.8 / 3.1    |
| David A. Cuadrado      | 731    | 111     | 35    | 1.2 / 2.6 / 1.7    |
| Jonas Ängeslevä        | 705    | 148     | 51    | 1.1 / 3.4 / 2.5    |
| Diego Algorta          | 650    | 6       | 5     | 1.0 / 0.1 / 0.2    |
| Arash Rouhani          | 629    | 95      | 31    | 1.0 / 2.2 / 1.5    |
| Sofia Larsson          | 595    | 70      | 77    | 0.9 / 1.6 / 3.8    |
| Tor Arne Vestbø        | 527    | 51      | 97    | 0.8 / 1.2 / 4.7    |
| spontus                | 339    | 18      | 42    | 0.5 / 0.4 / 2.0    |
| Pontus                 | 225    | 49      | 34    | 0.4 / 1.1 / 1.7    |
+------------------------+--------+---------+-------+--------------------+

But be warned: as mentioned by Jared in the comment, doing it on a very large repository will take hours. Not sure if that could be improved though, considering that it must process so much Git data.

How do you remove an invalid remote branch reference from Git?

I had a similar problem. None of the answers helped. In my case, I had two removed remote repositories showing up permanently.

My last idea was to remove all references to it by hand.

Let's say the repository is called “Repo”. I did:

find .git -name Repo 

So, I deleted the corresponding files and directories from the .git folder (this folder could be found in your Rails app or on your computer https://stackoverflow.com/a/19538763/6638513).

Then I did:

grep Repo -r .git

This found some text files in which I removed the corresponding lines. Now, everything seems to be fine.

Usually, you should leave this job to git.

Keep-alive header clarification

Where is this info kept ("this connection is between computer A and server F")?

A TCP connection is recognized by source IP and port and destination IP and port. Your OS, all intermediate session-aware devices and the server's OS will recognize the connection by this.

HTTP works with request-response: client connects to server, performs a request and gets a response. Without keep-alive, the connection to an HTTP server is closed after each response. With HTTP keep-alive you keep the underlying TCP connection open until certain criteria are met.

This allows for multiple request-response pairs over a single TCP connection, eliminating some of TCP's relatively slow connection startup.

When The IIS (F) sends keep alive header (or user sends keep-alive) , does it mean that (E,C,B) save a connection

No. Routers don't need to remember sessions. In fact, multiple TCP packets belonging to same TCP session need not all go through same routers - that is for TCP to manage. Routers just choose the best IP path and forward packets. Keep-alive is only for client, server and any other intermediate session-aware devices.

which is only for my session ?

Does it mean that no one else can use that connection

That is the intention of TCP connections: it is an end-to-end connection intended for only those two parties.

If so - does it mean that keep alive-header - reduce the number of overlapped connection users ?

Define "overlapped connections". See HTTP persistent connection for some advantages and disadvantages, such as:

  • Lower CPU and memory usage (because fewer connections are open simultaneously).
  • Enables HTTP pipelining of requests and responses.
  • Reduced network congestion (fewer TCP connections).
  • Reduced latency in subsequent requests (no handshaking).

if so , for how long does the connection is saved to me ? (in other words , if I set keep alive- "keep" till when?)

An typical keep-alive response looks like this:

Keep-Alive: timeout=15, max=100

See Hypertext Transfer Protocol (HTTP) Keep-Alive Header for example (a draft for HTTP/2 where the keep-alive header is explained in greater detail than both 2616 and 2086):

  • A host sets the value of the timeout parameter to the time that the host will allows an idle connection to remain open before it is closed. A connection is idle if no data is sent or received by a host.

  • The max parameter indicates the maximum number of requests that a client will make, or that a server will allow to be made on the persistent connection. Once the specified number of requests and responses have been sent, the host that included the parameter could close the connection.

However, the server is free to close the connection after an arbitrary time or number of requests (just as long as it returns the response to the current request). How this is implemented depends on your HTTP server.

Why is the apt-get function not working in the terminal on Mac OS X v10.9 (Mavericks)?

Alternatively You can use the brew or curl command for installing things, wherever apt-get is mentioned with a URL...

For example,

curl -O http://www.magentocommerce.com/downloads/assets/1.8.1.0/magento-1.8.1.0.tar.gz

Autonumber value of last inserted row - MS Access / VBA

If DAO use

RS.Move 0, RS.LastModified
lngID = RS!AutoNumberFieldName

If ADO use

cn.Execute "INSERT INTO TheTable.....", , adCmdText + adExecuteNoRecords
Set rs = cn.Execute("SELECT @@Identity", , adCmdText)
Debug.Print rs.Fields(0).Value

cn being a valid ADO connection, @@Identity will return the last Identity (Autonumber) inserted on this connection.

Note that @@Identity might be troublesome because the last generated value may not be the one you are interested in. For the Access database engine, consider a VIEW that joins two tables, both of which have the IDENTITY property, and you INSERT INTO the VIEW. For SQL Server, consider if there are triggers that in turn insert records into another table that also has the IDENTITY property.

BTW DMax would not work as if someone else inserts a record just after you've inserted one but before your Dmax function finishes excecuting, then you would get their record.

Get year, month or day from numpy datetime64

Another possibility is:

np.datetime64(dates,'Y') - returns - numpy.datetime64('2010')

or

np.datetime64(dates,'Y').astype(int)+1970 - returns - 2010

but works only on scalar values, won't take array

WPF MVVM: How to close a window

The solution to close a window in wpf that that worked for me is not answered here so i thought i would add my solution too.

        private static Window GetWindow(DependencyObject sender)
        {
            Window window = null;
            if (sender is Window)
                window = (Window)sender;
            if (window == null)
                window = Window.GetWindow(sender);
            return window;
        }
        private void CloseWindow(object sender, RoutedEventArgs e)
        {
            var button = (Button)sender as DependencyObject;

            Window window = GetWindow(button);
                if (window != null)
                    window.Close();
                   // window.Visibility = Visibility.Hidden; 
           // choose between window.close or set window.visibility to close or hide the window.

            //            }
        }

Add CloseWindow event to the button in you window as following.

<Button Content="Cancel" Click="CloseWindow" >

Linking static libraries to other static libraries

On Linux or MingW, with GNU toolchain:

ar -M <<EOM
    CREATE libab.a
    ADDLIB liba.a
    ADDLIB libb.a
    SAVE
    END
EOM
ranlib libab.a

Of if you do not delete liba.a and libb.a, you can make a "thin archive":

ar crsT libab.a liba.a libb.a

On Windows, with MSVC toolchain:

lib.exe /OUT:libab.lib liba.lib libb.lib

horizontal line and right way to code it in html, css

I wanted a long dash like line, so I used this.

_x000D_
_x000D_
.dash{_x000D_
        border: 1px solid red;_x000D_
        width: 120px;_x000D_
        height: 0px;_x000D_
_x000D_
}
_x000D_
<div class="dash"></div>
_x000D_
_x000D_
_x000D_

Find out where MySQL is installed on Mac OS X

To check MySQL version of MAMP , use the following command in Terminal:

/Applications/MAMP/Library/bin/mysql --version

Assume you have started MAMP .

Example output:

./mysql  Ver 14.14 Distrib 5.1.44, for apple-darwin8.11.1 (i386) using  EditLine wrapper

UPDATE: Moreover, if you want to find where does mysql installed in system, use the following command:

type -a mysql

type -a is an equivalent of tclsh built-in command where in OS X bash shell. If MySQL is found, it will show :

mysql is /usr/bin/mysql

If not found, it will show:

-bash: type: mysql: not found

By default , MySQL is not installed in Mac OS X.

Sidenote: For XAMPP, the command should be:

/Applications/XAMPP/xamppfiles/bin/mysql --version

Decode Hex String in Python 3

Something like:

>>> bytes.fromhex('4a4b4c').decode('utf-8')
'JKL'

Just put the actual encoding you are using.

Get size of all tables in database

The currently accepted answer has over 2600 up-votes but gives incorrect results when working with multiple partitions and/or filtered indexes. It also doesn't distinguish between the size of the data and indexes, which is often very relevant. Several suggested fixes don't address the core problem or are simply wrong as well.

The following query addresses all of those issues.

SELECT 
     [object_id]        = t.[object_id]
    ,[schema_name]      = s.[name]
    ,[table_name]       = t.[name]
    ,[index_name]       = CASE WHEN i.[type] in (0,1,5) THEN null    ELSE i.[name] END -- 0=Heap; 1=Clustered; 5=Clustered Columnstore
    ,[object_type]      = CASE WHEN i.[type] in (0,1,5) THEN 'TABLE' ELSE 'INDEX'  END
    ,[index_type]       = i.[type_desc]
    ,[partition_count]  = p.partition_count
    ,[row_count]        = p.[rows]
    ,[data_compression] = CASE WHEN p.data_compression_cnt > 1 THEN 'Mixed'
                               ELSE (  SELECT DISTINCT p.data_compression_desc
                                       FROM sys.partitions p
                                       WHERE i.[object_id] = p.[object_id] AND i.index_id = p.index_id
                                    )
                          END
    ,[total_space_MB]   = cast(round(( au.total_pages                  * (8/1024.00)), 2) AS DECIMAL(36,2))
    ,[used_space_MB]    = cast(round(( au.used_pages                   * (8/1024.00)), 2) AS DECIMAL(36,2))
    ,[unused_space_MB]  = cast(round(((au.total_pages - au.used_pages) * (8/1024.00)), 2) AS DECIMAL(36,2))
FROM sys.schemas s
JOIN sys.tables  t ON s.schema_id = t.schema_id
JOIN sys.indexes i ON t.object_id = i.object_id
JOIN (
    SELECT [object_id], index_id, partition_count=count(*), [rows]=sum([rows]), data_compression_cnt=count(distinct [data_compression])
    FROM sys.partitions
    GROUP BY [object_id], [index_id]
) p ON i.[object_id] = p.[object_id] AND i.[index_id] = p.[index_id]
JOIN (
    SELECT p.[object_id], p.[index_id], total_pages = sum(a.total_pages), used_pages = sum(a.used_pages), data_pages=sum(a.data_pages)
    FROM sys.partitions p
    JOIN sys.allocation_units a ON p.[partition_id] = a.[container_id]
    GROUP BY p.[object_id], p.[index_id]
) au ON i.[object_id] = au.[object_id] AND i.[index_id] = au.[index_id]
WHERE t.is_ms_shipped = 0 -- Not a system table

In log4j, does checking isDebugEnabled before logging improve performance?

As of 2.x, Apache Log4j has this check built in, so having isDebugEnabled() isn't necessary anymore. Just do a debug() and the messages will be suppressed if not enabled.

Create a text file for download on-the-fly

<?php

    header('Content-type: text/plain');
    header('Content-Disposition: attachment;
            filename="<name for the created file>"');
    /*
    assign file content to a PHP Variable $content
    */
    echo $content;
?>

SQL LEFT JOIN Subquery Alias

I recognize that the answer works and has been accepted but there is a much cleaner way to write that query. Tested on mysql and postgres.

SELECT wpoi.order_id As No_Commande
FROM  wp_woocommerce_order_items AS wpoi
LEFT JOIN wp_postmeta AS wpp ON wpoi.order_id = wpp.post_id 
                            AND wpp.meta_key = '_shipping_first_name'
WHERE  wpoi.order_id =2198 

When should I use GC.SuppressFinalize()?

If a class, or anything derived from it, might hold the last live reference to an object with a finalizer, then either GC.SuppressFinalize(this) or GC.KeepAlive(this) should be called on the object after any operation that might be adversely affected by that finalizer, thus ensuring that the finalizer won't run until after that operation is complete.

The cost of GC.KeepAlive() and GC.SuppressFinalize(this) are essentially the same in any class that doesn't have a finalizer, and classes that do have finalizers should generally call GC.SuppressFinalize(this), so using the latter function as the last step of Dispose() may not always be necessary, but it won't be wrong.

VBA Public Array : how to?

Declare array as global across subs in a application:

Public GlobalArray(10) as String
GlobalArray = Array('A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L')

Sub DisplayArray()
    Dim i As Integer

    For i = 0 to UBound(GlobalArray, 1)
        MsgBox GlobalArray(i)

    Next i
End Sub

Method 2: Pass an array to sub. Use ParamArray.

Sub DisplayArray(Name As String, ParamArray Arr() As Variant)
    Dim i As Integer

    For i = 0 To UBound(Arr())
        MsgBox Name & ": " & Arr(i)
    Next i
End Sub

ParamArray must be the last parameter.

JavaScript error (Uncaught SyntaxError: Unexpected end of input)

I think it could be almost any javascript error/typing error in your application. I tried to delete one file content after another and finally found the typing error.

Cannot find either column "dbo" or the user-defined function or aggregate "dbo.Splitfn", or the name is ambiguous

You need to treat a table valued udf like a table, eg JOIN it

select Emp_Id 
from Employee E JOIN dbo.Splitfn(@Id,',') CSV ON E.Emp_Id = CSV.items 

Gradient of n colors ranging from color 1 and color 2

The above answer is useful but in graphs, it is difficult to distinguish between darker gradients of black. One alternative I found is to use gradients of gray colors as follows

palette(gray.colors(10, 0.9, 0.4))
plot(rep(1,10),col=1:10,pch=19,cex=3))

More info on gray scale here.

Added

When I used the code above for different colours like blue and black, the gradients were not that clear. heat.colors() seems more useful.

This document has more detailed information and options. pdf

How to set the Default Page in ASP.NET?

Tip #84: Did you know… How to set a Start page for your Web Site in Visual Web Developer?

Simply right click on the page you want to be the start page and say "set as start page".

As noted in the comment below by Adam Tuliper - MSFT, this only works for debugging, not deployment.

DataGridView checkbox column - value and functionality

Here's a one liner answer for this question

List<DataGridViewRow> list = DataGridView1.Rows.Cast<DataGridViewRow>().Where(k => Convert.ToBoolean(k.Cells[CheckBoxColumn1.Name].Value) == true).ToList();

Replace comma with newline in sed on MacOS?

FWIW, the following line works in windows and replaces semicolons in my path variables with a newline. I'm using the tools installed under my git bin directory.

echo %path% | sed -e $'s/;/\\n/g' | less

Delete multiple objects in django

You can delete any QuerySet you'd like. For example, to delete all blog posts with some Post model

Post.objects.all().delete()

and to delete any Post with a future publication date

Post.objects.filter(pub_date__gt=datetime.now()).delete()

You do, however, need to come up with a way to narrow down your QuerySet. If you just want a view to delete a particular object, look into the delete generic view.

EDIT:

Sorry for the misunderstanding. I think the answer is somewhere between. To implement your own, combine ModelForms and generic views. Otherwise, look into 3rd party apps that provide similar functionality. In a related question, the recommendation was django-filter.

How to set max and min value for Y axis

There's so many conflicting answers to this, most of which had no effect for me.

I was finally able to set (or retrieve current) X-axis minimum & maximum displayed values with chart.options.scales.xAxes[0].ticks.min (even if min & max are only a subset of the data assigned to the chart.)

Using a time scale in my case, I used:

chart.options.scales.xAxes[0].ticks.min = 1590969600000;  //Jun 1, 2020
chart.options.scales.xAxes[0].ticks.max = 1593561600000;  //Jul 1, 2020
chart.update();

(I found no need to set the step values or beginAtZero, etc.)

How can I build for release/distribution on the Xcode 4?

They've bundled all the target/build configuration/debugging options stuff into "schemes". The transition guide has a good explanation.

Android screen size HDPI, LDPI, MDPI

You should read Supporting multiple screens. You must define dpi on your emulator. 240 is hdpi, 160 is mdpi and below that are usually ldpi.

Extract from Android Developer Guide link above:

320dp: a typical phone screen (240x320 ldpi, 320x480 mdpi, 480x800 hdpi, etc).  
480dp: a tweener tablet like the Streak (480x800 mdpi).  
600dp: a 7” tablet (600x1024 mdpi).  
720dp: a 10” tablet (720x1280 mdpi, 800x1280 mdpi, etc).

Jackson and generic type reference

I modified rushidesai1's answer to include a working example.

JsonMarshaller.java

import java.io.*;
import java.util.*;

public class JsonMarshaller<T> {
    private static ClassLoader loader = JsonMarshaller.class.getClassLoader();

    public static void main(String[] args) {
        try {
            JsonMarshallerUnmarshaller<Station> marshaller = new JsonMarshallerUnmarshaller<>(Station.class);
            String jsonString = read(loader.getResourceAsStream("data.json"));
            List<Station> stations = marshaller.unmarshal(jsonString);
            stations.forEach(System.out::println);
            System.out.println(marshaller.marshal(stations));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @SuppressWarnings("resource")
    public static String read(InputStream ios) {
        return new Scanner(ios).useDelimiter("\\A").next(); // Read the entire file
    }
}

Output

Station [id=123, title=my title, name=my name]
Station [id=456, title=my title 2, name=my name 2]
[{"id":123,"title":"my title","name":"my name"},{"id":456,"title":"my title 2","name":"my name 2"}]

JsonMarshallerUnmarshaller.java

import java.io.*;
import java.util.List;

import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.introspect.JacksonAnnotationIntrospector;

public class JsonMarshallerUnmarshaller<T> {
    private ObjectMapper mapper;
    private Class<T> targetClass;

    public JsonMarshallerUnmarshaller(Class<T> targetClass) {
        AnnotationIntrospector introspector = new JacksonAnnotationIntrospector();

        mapper = new ObjectMapper();
        mapper.getDeserializationConfig().with(introspector);
        mapper.getSerializationConfig().with(introspector);

        this.targetClass = targetClass;
    }

    public List<T> unmarshal(String jsonString) throws JsonParseException, JsonMappingException, IOException {
        return parseList(jsonString, mapper, targetClass);
    }

    public String marshal(List<T> list) throws JsonProcessingException {
        return mapper.writeValueAsString(list);
    }

    public static <E> List<E> parseList(String str, ObjectMapper mapper, Class<E> clazz)
            throws JsonParseException, JsonMappingException, IOException {
        return mapper.readValue(str, listType(mapper, clazz));
    }

    public static <E> List<E> parseList(InputStream is, ObjectMapper mapper, Class<E> clazz)
            throws JsonParseException, JsonMappingException, IOException {
        return mapper.readValue(is, listType(mapper, clazz));
    }

    public static <E> JavaType listType(ObjectMapper mapper, Class<E> clazz) {
        return mapper.getTypeFactory().constructCollectionType(List.class, clazz);
    }
}

Station.java

public class Station {
    private long id;
    private String title;
    private String name;

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return String.format("Station [id=%s, title=%s, name=%s]", id, title, name);
    }
}

data.json

[{
  "id": 123,
  "title": "my title",
  "name": "my name"
}, {
  "id": 456,
  "title": "my title 2",
  "name": "my name 2"
}]

How to keep :active css style after click a button

CSS

:active denotes the interaction state (so for a button will be applied during press), :focus may be a better choice here. However, the styling will be lost once another element gains focus.

The final potential alternative using CSS would be to use :target, assuming the items being clicked are setting routes (e.g. anchors) within the page- however this can be interrupted if you are using routing (e.g. Angular), however this doesnt seem the case here.

_x000D_
_x000D_
.active:active {_x000D_
  color: red;_x000D_
}_x000D_
.focus:focus {_x000D_
  color: red;_x000D_
}_x000D_
:target {_x000D_
  color: red;_x000D_
}
_x000D_
<button class='active'>Active</button>_x000D_
<button class='focus'>Focus</button>_x000D_
<a href='#target1' id='target1' class='target'>Target 1</a>_x000D_
<a href='#target2' id='target2' class='target'>Target 2</a>_x000D_
<a href='#target3' id='target3' class='target'>Target 3</a>
_x000D_
_x000D_
_x000D_

Javascript / jQuery

As such, there is no way in CSS to absolutely toggle a styled state- if none of the above work for you, you will either need to combine with a change in your HTML (e.g. based on a checkbox) or programatically apply/remove a class using e.g. jQuery

_x000D_
_x000D_
$('button').on('click', function(){_x000D_
    $('button').removeClass('selected');_x000D_
    $(this).addClass('selected');_x000D_
});
_x000D_
button.selected{_x000D_
  color:red;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
_x000D_
<button>Item</button><button>Item</button><button>Item</button>_x000D_
  
_x000D_
_x000D_
_x000D_

Loop through files in a folder using VBA?

The Dir function is the way to go, but the problem is that you cannot use the Dir function recursively, as stated here, towards the bottom.

The way that I've handled this is to use the Dir function to get all of the sub-folders for the target folder and load them into an array, then pass the array into a function that recurses.

Here's a class that I wrote that accomplishes this, it includes the ability to search for filters. (You'll have to forgive the Hungarian Notation, this was written when it was all the rage.)

Private m_asFilters() As String
Private m_asFiles As Variant
Private m_lNext As Long
Private m_lMax As Long

Public Function GetFileList(ByVal ParentDir As String, Optional ByVal sSearch As String, Optional ByVal Deep As Boolean = True) As Variant
    m_lNext = 0
    m_lMax = 0

    ReDim m_asFiles(0)
    If Len(sSearch) Then
        m_asFilters() = Split(sSearch, "|")
    Else
        ReDim m_asFilters(0)
    End If

    If Deep Then
        Call RecursiveAddFiles(ParentDir)
    Else
        Call AddFiles(ParentDir)
    End If

    If m_lNext Then
        ReDim Preserve m_asFiles(m_lNext - 1)
        GetFileList = m_asFiles
    End If

End Function

Private Sub RecursiveAddFiles(ByVal ParentDir As String)
    Dim asDirs() As String
    Dim l As Long
    On Error GoTo ErrRecursiveAddFiles
    'Add the files in 'this' directory!


    Call AddFiles(ParentDir)

    ReDim asDirs(-1 To -1)
    asDirs = GetDirList(ParentDir)
    For l = 0 To UBound(asDirs)
        Call RecursiveAddFiles(asDirs(l))
    Next l
    On Error GoTo 0
Exit Sub
ErrRecursiveAddFiles:
End Sub
Private Function GetDirList(ByVal ParentDir As String) As String()
    Dim sDir As String
    Dim asRet() As String
    Dim l As Long
    Dim lMax As Long

    If Right(ParentDir, 1) <> "\" Then
        ParentDir = ParentDir & "\"
    End If
    sDir = Dir(ParentDir, vbDirectory Or vbHidden Or vbSystem)
    Do While Len(sDir)
        If GetAttr(ParentDir & sDir) And vbDirectory Then
            If Not (sDir = "." Or sDir = "..") Then
                If l >= lMax Then
                    lMax = lMax + 10
                    ReDim Preserve asRet(lMax)
                End If
                asRet(l) = ParentDir & sDir
                l = l + 1
            End If
        End If
        sDir = Dir
    Loop
    If l Then
        ReDim Preserve asRet(l - 1)
        GetDirList = asRet()
    End If
End Function
Private Sub AddFiles(ByVal ParentDir As String)
    Dim sFile As String
    Dim l As Long

    If Right(ParentDir, 1) <> "\" Then
        ParentDir = ParentDir & "\"
    End If

    For l = 0 To UBound(m_asFilters)
        sFile = Dir(ParentDir & "\" & m_asFilters(l), vbArchive Or vbHidden Or vbNormal Or vbReadOnly Or vbSystem)
        Do While Len(sFile)
            If Not (sFile = "." Or sFile = "..") Then
                If m_lNext >= m_lMax Then
                    m_lMax = m_lMax + 100
                    ReDim Preserve m_asFiles(m_lMax)
                End If
                m_asFiles(m_lNext) = ParentDir & sFile
                m_lNext = m_lNext + 1
            End If
            sFile = Dir
        Loop
    Next l
End Sub

Strip last two characters of a column in MySQL

To select all characters except the last n from a string (or put another way, remove last n characters from a string); use the SUBSTRING and CHAR_LENGTH functions together:

SELECT col
     , /* ANSI Syntax  */ SUBSTRING(col FROM 1 FOR CHAR_LENGTH(col) - 2) AS col_trimmed
     , /* MySQL Syntax */ SUBSTRING(col,     1,    CHAR_LENGTH(col) - 2) AS col_trimmed
FROM tbl

To remove a specific substring from the end of string, use the TRIM function:

SELECT col
     , TRIM(TRAILING '.php' FROM col)
-- index.php becomes index
-- index.txt remains index.txt

Displaying the Indian currency symbol on a website

You can do it with Intl.NumberFormat native API.

_x000D_
_x000D_
var number = 123456.78;_x000D_
_x000D_
// India uses thousands/lakh/crore separators_x000D_
console.log(new Intl.NumberFormat('en-IN', {_x000D_
  style: 'currency',_x000D_
  currency: 'INR'_x000D_
}).format(number));
_x000D_
_x000D_
_x000D_

How do I initialize Kotlin's MutableList to empty MutableList?

I do like below to :

var book: MutableList<Books> = mutableListOf()

/** Returns a new [MutableList] with the given elements. */

public fun <T> mutableListOf(vararg elements: T): MutableList<T>
    = if (elements.size == 0) ArrayList() else ArrayList(ArrayAsCollection(elements, isVarargs = true))

Replace all occurrences of a string in a data frame

I had the problem, I had to replace "Not Available" with NA and my solution goes like this

data <- sapply(data,function(x) {x <- gsub("Not Available",NA,x)})

repository element was not specified in the POM inside distributionManagement element or in -DaltDep loymentRepository=id::layout::url parameter

In your pom.xml you should add distributionManagement configuration to where to deploy.

In the following example I have used file system as the locations.

<distributionManagement>
       <repository>
         <id>internal.repo</id>
         <name>Internal repo</name>
         <url>file:///home/thara/testesb/in</url>
       </repository>
   </distributionManagement>

you can add another location while deployment by using the following command (but to avoid above error you should have at least 1 repository configured) :

mvn deploy -DaltDeploymentRepository=internal.repo::default::file:///home/thara/testesb/in

Why I can't access remote Jupyter Notebook server?

In RedHat 7, we need to allow the specific port before running the Jupiter command. Say the port is 8080.

iptables -I INPUT 1 -p tcp --dport 8080 -j ACCEPT

Then we can run it normally. For instance, using:

jupyter notebook --ip 0.0.0.0 --no-browser --port=8080 --allow-root

or whatever you like.

Making the iPhone vibrate

Important Note: Alert of Future Deprecation.

As of iOS 9.0, the API functions description for:

AudioServicesPlaySystemSound(inSystemSoundID: SystemSoundID)
AudioServicesPlayAlertSound(inSystemSoundID: SystemSoundID)

includes the following note:

This function will be deprecated in a future release.
Use AudioServicesPlayAlertSoundWithCompletion or  
AudioServicesPlaySystemSoundWithCompletion instead.

The right way to go will be using any of these two:

AudioServicesPlayAlertSoundWithCompletion(kSystemSoundID_Vibrate, nil)

or

AudioServicesPlayAlertSoundWithCompletion(kSystemSoundID_Vibrate) {
 //your callback code when the vibration is done (it may not vibrate in iPod, but this callback will be always called)
}

remember to import AVFoundation

Chrome ignores autocomplete="off"

After the chrome v. 34, setting autocomplete="off" at <form> tag doesn`t work

I made the changes to avoid this annoying behavior:

  1. Remove the name and the id of the password input
  2. Put a class in the input (ex.: passwordInput )

(So far, Chrome wont put the saved password on the input, but the form is now broken)

Finally, to make the form work, put this code to run when the user click the submit button, or whenever you want to trigger the form submittion:

var sI = $(".passwordInput")[0];
$(sI).attr("id", "password");
$(sI).attr("name", "password");

In my case, I used to hav id="password" name="password" in the password input, so I put them back before trigger the submition.

Code signing is required for product type 'Application' in SDK 'iOS5.1'

One possible solution which works for me:

  1. Search "code sign" in Build settings
  2. Change everything in code signing identity to "iOS developer", which are "Don't code sign" originally.

Bravo!

Bloomberg Open API

This API has been available for a long time and enables to get access to market data (including live) if you are running a Bloomberg Terminal or have access to a Bloomberg Server, which is chargeable.

The only difference is that the API (not its code) has been open sourced, so it can now be used as a dependency in an open source project for example, without any copyrights issues, which was not the case before.

Reference requirements.txt for the install_requires kwarg in setuptools setup.py file

Most of the other answers above don't work with the current version of pip's API. Here is the correct* way to do it with the current version of pip (6.0.8 at the time of writing, also worked in 7.1.2. You can check your version with pip -V).

from pip.req import parse_requirements
from pip.download import PipSession

install_reqs = parse_requirements(<requirements_path>, session=PipSession())

reqs = [str(ir.req) for ir in install_reqs]

setup(
    ...
    install_requires=reqs
    ....
)

* Correct, in that it is the way to use parse_requirements with the current pip. It still probably isn't the best way to do it, since, as posters above said, pip doesn't really maintain an API.

How can I manually set an Angular form field as invalid?

I was trying to call setErrors() inside a ngModelChange handler in a template form. It did not work until I waited one tick with setTimeout():

template:

<input type="password" [(ngModel)]="user.password" class="form-control" 
 id="password" name="password" required (ngModelChange)="checkPasswords()">

<input type="password" [(ngModel)]="pwConfirm" class="form-control"
 id="pwConfirm" name="pwConfirm" required (ngModelChange)="checkPasswords()"
 #pwConfirmModel="ngModel">

<div [hidden]="pwConfirmModel.valid || pwConfirmModel.pristine" class="alert-danger">
   Passwords do not match
</div>

component:

@ViewChild('pwConfirmModel') pwConfirmModel: NgModel;

checkPasswords() {
  if (this.pwConfirm.length >= this.user.password.length &&
      this.pwConfirm !== this.user.password) {
    console.log('passwords do not match');
    // setErrors() must be called after change detection runs
    setTimeout(() => this.pwConfirmModel.control.setErrors({'nomatch': true}) );
  } else {
    // to clear the error, we don't have to wait
    this.pwConfirmModel.control.setErrors(null);
  }
}

Gotchas like this are making me prefer reactive forms.

Python: TypeError: cannot concatenate 'str' and 'int' objects

c = a + b 
str(c)

Actually, in this last line you are not changing the type of the variable c. If you do

c_str=str(c)
print "a + b as integers: " + c_str

it should work.

Constructor of an abstract class in C#

You can instantiate it after you implemented all the methods. Then the constructor will be called.

How can I add a new column and data to a datatable that already contains data?

Try this

> dt.columns.Add("ColumnName", typeof(Give the type you want));
> dt.Rows[give the row no like  or  or any no]["Column name in which you want to add data"] = Value;

How to add a .dll reference to a project in Visual Studio

Copy the downloaded DLL file in a custom folder on your dev drive, then add the reference to your project using the Browse button in the Add Reference dialog.
Be sure that the new reference has the Copy Local = True.
The Add Reference dialog could be opened right-clicking on the References item in your project in Solution Explorer

UPDATE AFTER SOME YEARS
At the present time the best way to resolve all those problems is through the
Manage NuGet packages menu command of Visual Studio 2017/2019.
You can right click on the References node of your project and select that command. From the Browse tab search for the library you want to use in the NuGet repository, click on the item if found and then Install it. (Of course you need to have a package for that DLL and this is not guaranteed to exist)

Read about NuGet here

How do you create different variable names while in a loop?

One way you can do this is with exec(). For example:

for k in range(5):
    exec(f'cat_{k} = k*2')
>>> print(cat_0)
0
>>> print(cat_1)
2
>>> print(cat_2)
4
>>> print(cat_3)
6
>>> print(cat_4)
8

Here I am taking advantage of the handy f string formatting in Python 3.6+

@Autowired - No qualifying bean of type found for dependency

This may help you:

I have the same exception in my project. After searching while I found that I am missing the @Service annotation to the class where I am implementing the interface which I want to @Autowired.

In your code you can add the @Service annotation to MailManager class.

@Transactional
@Service
public class MailManager extends AbstractManager implements IMailManager {

MongoDB or CouchDB - fit for production?

We are using MongoDB in production in our mobile backend service namely Netmera. We are using it to store all user and content data.

How can I get current date in Android?

CharSequence s  = DateFormat.getDateInstance().format("MMMM d, yyyy ");

You need an instance first

Selenium Webdriver: Entering text into text field

I had a case where I was entering text into a field after which the text would be removed automatically. Turned out it was due to some site functionality where you had to press the enter key after entering the text into the field. So, after sending your barcode text with sendKeys method, send 'enter' directly after it. Note that you will have to import the selenium Keys class. See my code below.

import org.openqa.selenium.Keys;

String barcode="0000000047166";
WebElement element_enter = driver.findElement(By.xpath("//*[@id='div-barcode']"));
element_enter.findElement(By.xpath("your xpath")).sendKeys(barcode);

element_enter.sendKeys(Keys.RETURN); // this will result in the return key being pressed upon the text field

I hope it helps..

The import com.google.android.gms cannot be resolved

Another way is to let Eclipse do the import work for you. Hover your mouse over the com.google.android.gms import that can not be resolved and towards the bottom of the popup menu, select the Fix project setup... option as below. Then it'll prompt to import the google play services library. Select that and you should be good to go.

enter image description here

c# search string in txt file

You have to use while since foreach does not know about index. Below is an example code.

int counter = 0;
string line;

Console.Write("Input your search text: ");
var text = Console.ReadLine();

System.IO.StreamReader file =
    new System.IO.StreamReader("SampleInput1.txt");

while ((line = file.ReadLine()) != null)
{
    if (line.Contains(text))
    {
        break;
    }

    counter++;
}

Console.WriteLine("Line number: {0}", counter);

file.Close();

Console.ReadLine();

How to fix: Error device not found with ADB.exe

If you installed Eclipse have Android SDK, go to DDMS. If the list device display "?????????"

you do adb kill-server and then adb start-server.

Please make sure you install USB driver and enable debug mode.

GCC -fPIC option

The link to a function in a dynamic library is resolved when the library is loaded or at run time. Therefore, both the executable file and dynamic library are loaded into memory when the program is run. The memory address at which a dynamic library is loaded cannot be determined in advance, because a fixed address might clash with another dynamic library requiring the same address.


There are two commonly used methods for dealing with this problem:

1.Relocation. All pointers and addresses in the code are modified, if necessary, to fit the actual load address. Relocation is done by the linker and the loader.

2.Position-independent code. All addresses in the code are relative to the current position. Shared objects in Unix-like systems use position-independent code by default. This is less efficient than relocation if program run for a long time, especially in 32-bit mode.


The name "position-independent code" actually implies following:

  • The code section contains no absolute addresses that need relocation, but only self relative addresses. Therefore, the code section can be loaded at an arbitrary memory address and shared between multiple processes.

  • The data section is not shared between multiple processes because it often contains writeable data. Therefore, the data section may contain pointers or addresses that need relocation.

  • All public functions and public data can be overridden in Linux. If a function in the main executable has the same name as a function in a shared object, then the version in main will take precedence, not only when called from main, but also when called from the shared object. Likewise, when a global variable in main has the same name as a global variable in the shared object, then the instance in main will be used, even when accessed from the shared object.


This so-called symbol interposition is intended to mimic the behavior of static libraries.

A shared object has a table of pointers to its functions, called procedure linkage table (PLT) and a table of pointers to its variables called global offset table (GOT) in order to implement this "override" feature. All accesses to functions and public variables go through this tables.

p.s. Where dynamic linking cannot be avoided, there are various ways to avoid the timeconsuming features of the position-independent code.

You can read more from this article: http://www.agner.org/optimize/optimizing_cpp.pdf

How do I parse a string into a number with Dart?

As per dart 2.6

The optional onError parameter of int.parse is deprecated. Therefore, you should use int.tryParse instead.

Note: The same applies to double.parse. Therefore, use double.tryParse instead.

  /**
   * ...
   *
   * The [onError] parameter is deprecated and will be removed.
   * Instead of `int.parse(string, onError: (string) => ...)`,
   * you should use `int.tryParse(string) ?? (...)`.
   *
   * ...
   */
  external static int parse(String source, {int radix, @deprecated int onError(String source)});

The difference is that int.tryParse returns null if the source string is invalid.

  /**
   * Parse [source] as a, possibly signed, integer literal and return its value.
   *
   * Like [parse] except that this function returns `null` where a
   * similar call to [parse] would throw a [FormatException],
   * and the [source] must still not be `null`.
   */
  external static int tryParse(String source, {int radix});

So, in your case it should look like:

// Valid source value
int parsedValue1 = int.tryParse('12345');
print(parsedValue1); // 12345

// Error handling
int parsedValue2 = int.tryParse('');
if (parsedValue2 == null) {
  print(parsedValue2); // null
  //
  // handle the error here ...
  //
}

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

Instead of using opacity, set a background-color with rgba, where 'a' is the level of transparency.

So instead of:

background-color: rgb(0,0,255); opacity: 0.5;

use

background-color: rgba(0,0,255,0.5);

How is a CRC32 checksum calculated?

Then there is always Rosetta Code, which shows crc32 implemented in dozens of computer languages. https://rosettacode.org/wiki/CRC-32 and has links to many explanations and implementations.

How to handle ListView click in Android

You need to set the inflated view "Clickable" and "able to listen to click events" in your adapter class getView() method.

convertView = mInflater.inflate(R.layout.list_item_text, null);
convertView.setClickable(true);
convertView.setOnClickListener(myClickListener);

and declare the click listener in your ListActivity as follows,

public OnClickListener myClickListener = new OnClickListener() {
public void onClick(View v) {
                 //code to be written to handle the click event
    }
};

This holds true only when you are customizing the Adapter by extending BaseAdapter.

Refer the ANDROID_SDK/samples/ApiDemos/src/com/example/android/apis/view/List14.java for more details

How to display table data more clearly in oracle sqlplus

You can set the line size as per the width of the window and set wrap off using the following command.

set linesize 160;
set wrap off;

I have used 160 as per my preference you can set it to somewhere between 100 - 200 and setting wrap will not your data and it will display the data properly.

CSS: Fix row height

_x000D_
_x000D_
    _x000D_
    table tbody_x000D_
    {_x000D_
        border:1px solid red;_x000D_
    }_x000D_
    table td_x000D_
    {_x000D_
        background:yellow;_x000D_
        _x000D_
        border-bottom:1px solid green;_x000D_
        _x000D_
        _x000D_
    }_x000D_
    .tr0{_x000D_
        line-height:0;_x000D_
     }_x000D_
     .tr0 td{_x000D_
        background:red;_x000D_
     }
_x000D_
<table>_x000D_
<tbody>_x000D_
    <tr><td>test</td></tr>_x000D_
    <tr><td>test</td></tr>    _x000D_
    <tr class="tr0"><td></td></tr>_x000D_
</tbody>_x000D_
</table>
_x000D_
_x000D_
_x000D_

How to include a quote in a raw Python string

Use:

dqote='"'
sqote="'"

Use the '+' operator and dqote and squote variables to get what you need.

If I want sed -e s/",u'"/",'"/g -e s/^"u'"/"'"/, you can try the following:

dqote='"'
sqote="'"
cmd1="sed -e s/" + dqote + ",u'" + dqote + "/" + dqote + ",'" + dqote + '/g -e s/^"u' + sqote + dqote + '/' + dqote + sqote + dqote + '/'

android adb turn on wifi via adb

I was in the same situation on a Samsung Mini II. I got around it eventually by holding down the power button until the "power off" menu appeared. From this menu it was possible to enable the network data connection.

Then signing in to my google account using @googlemail.com (rather than @gmail.com) seemed to do the trick. Though the change of address may just have given the phone time to warm up the 3g connection rather than making any real difference.

how to get the value of a textarea in jquery?

in javascript :

document.getElementById("message").value

Fatal error: Uncaught Error: Call to undefined function mysql_connect()

mysql_ functions have been removed from PHP 7. You can now use MySQLi or PDO.

MySQLi example:

mysqli_connect($mysql_hostname, $mysql_username, $mysql_password, $mysql_dbname);

mysqli_connect reference link

What is the meaning of the word logits in TensorFlow?

logits

The vector of raw (non-normalized) predictions that a classification model generates, which is ordinarily then passed to a normalization function. If the model is solving a multi-class classification problem, logits typically become an input to the softmax function. The softmax function then generates a vector of (normalized) probabilities with one value for each possible class.

In addition, logits sometimes refer to the element-wise inverse of the sigmoid function. For more information, see tf.nn.sigmoid_cross_entropy_with_logits.

official tensorflow documentation

Add and remove multiple classes in jQuery

Add multiple classes:

$("p").addClass("class1 class2 class3");

or in cascade:

$("p").addClass("class1").addClass("class2").addClass("class3");

Very similar also to remove more classes:

$("p").removeClass("class1 class2 class3");

or in cascade:

$("p").removeClass("class1").removeClass("class2").removeClass("class3");

Printing newlines with print() in R

An alternative to cat() is writeLines():

> writeLines("File not supplied.\nUsage: ./program F=filename")
File not supplied.
Usage: ./program F=filename
>

An advantage is that you don't have to remember to append a "\n" to the string passed to cat() to get a newline after your message. E.g. compare the above to the same cat() output:

> cat("File not supplied.\nUsage: ./program F=filename")
File not supplied.
Usage: ./program F=filename>

and

> cat("File not supplied.\nUsage: ./program F=filename","\n")
File not supplied.
Usage: ./program F=filename
>

The reason print() doesn't do what you want is that print() shows you a version of the object from the R level - in this case it is a character string. You need to use other functions like cat() and writeLines() to display the string. I say "a version" because precision may be reduced in printed numerics, and the printed object may be augmented with extra information, for example.

Regex to extract URLs from href attribute in HTML with Python

import re

url = '<p>Hello World</p><a href="http://example.com">More Examples</a><a href="http://example2.com">Even More Examples</a>'

urls = re.findall('https?://(?:[-\w.]|(?:%[\da-fA-F]{2}))+', url)

>>> print urls
['http://example.com', 'http://example2.com']

How do I pick 2 random items from a Python set?

Use the random module: http://docs.python.org/library/random.html

import random
random.sample(set([1, 2, 3, 4, 5, 6]), 2)

This samples the two values without replacement (so the two values are different).

How can I decrypt a password hash in PHP?

Bcrypt is a one-way hashing algorithm, you can't decrypt hashes. Use password_verify to check whether a password matches the stored hash:

<?php
// See the password_hash() example to see where this came from.
$hash = '$2y$07$BCryptRequires22Chrcte/VlQH0piJtjXl.0t1XkA8pw9dMXTpOq';

if (password_verify('rasmuslerdorf', $hash)) {
    echo 'Password is valid!';
} else {
    echo 'Invalid password.';
}

In your case, run the SQL query using only the username:

$sql_script = 'SELECT * FROM USERS WHERE username=?';

And do the password validation in PHP using a code that is similar to the example above.

The way you are constructing the query is very dangerous. If you don't parameterize the input properly, the code will be vulnerable to SQL injection attacks. See this Stack Overflow answer on how to prevent SQL injection.

ERROR Error: Uncaught (in promise), Cannot match any routes. URL Segment

As the error says your router link should match the existing routes configured

It should be just routerLink="/about"

What port is a given program using?

"netstat -natp" is what I always use.

Swift Set to Array

I created a simple extension that gives you an unsorted Array as a property of Set in Swift 4.0.

extension Set {
    var array: [Element] {
        return Array(self)
    }
}

If you want a sorted array, you can either add an additional computed property, or modify the existing one to suit your needs.

To use this, just call

let array = set.array

How to build an APK file in Eclipse?

The simplest way to create signed/unsigned APKs using Eclipse and ADT is as follows:

  1. Right click your project in the "Project Explorer"
  2. Hover over "Android Tools"
  3. Select either "Export Signed Application Package" or "Export Unsigned Application Package"
  4. Select the location for the new APK file and click "Save".

    • NOTE: If you're trying to build a APK for beta distribution, you'll probably need to create a signed package, which requires a keystore. If you follow the "Signed Application" process in Eclipse ADT it will guide you through the process of creating a new keystore.

Hope this helps.

How to add and get Header values in WebApi

For .NET Core:

string Token = Request.Headers["Custom"];

Or

var re = Request;
var headers = re.Headers;
string token = string.Empty;
StringValues x = default(StringValues);
if (headers.ContainsKey("Custom"))
{
   var m = headers.TryGetValue("Custom", out x);
}

Difference between exit() and sys.exit() in Python

exit is a helper for the interactive shell - sys.exit is intended for use in programs.

The site module (which is imported automatically during startup, except if the -S command-line option is given) adds several constants to the built-in namespace (e.g. exit). They are useful for the interactive interpreter shell and should not be used in programs.


Technically, they do mostly the same: raising SystemExit. sys.exit does so in sysmodule.c:

static PyObject *
sys_exit(PyObject *self, PyObject *args)
{
    PyObject *exit_code = 0;
    if (!PyArg_UnpackTuple(args, "exit", 0, 1, &exit_code))
        return NULL;
    /* Raise SystemExit so callers may catch it or clean up. */
    PyErr_SetObject(PyExc_SystemExit, exit_code);
   return NULL;
}

While exit is defined in site.py and _sitebuiltins.py, respectively.

class Quitter(object):
    def __init__(self, name):
        self.name = name
    def __repr__(self):
        return 'Use %s() or %s to exit' % (self.name, eof)
    def __call__(self, code=None):
        # Shells like IDLE catch the SystemExit, but listen when their
        # stdin wrapper is closed.
        try:
            sys.stdin.close()
        except:
            pass
        raise SystemExit(code)
__builtin__.quit = Quitter('quit')
__builtin__.exit = Quitter('exit')

Note that there is a third exit option, namely os._exit, which exits without calling cleanup handlers, flushing stdio buffers, etc. (and which should normally only be used in the child process after a fork()).

Left join only selected columns in R with the merge() function

You can do this by subsetting the data you pass into your merge:

merge(x = DF1, y = DF2[ , c("Client", "LO")], by = "Client", all.x=TRUE)

Or you can simply delete the column after your current merge :)

WCF gives an unsecured or incorrectly secured fault error

In my case the server time was not correct. So I changed the server Datetime settings to Set time automatically and it resolved the issue.

The correct way to read a data file into an array

It depends on the size of the file! The solutions above tend to use convenient shorthands to copy the entire file into memory, which will work in many cases.

For very large files you may need to use a streaming design where read the file by line or in chucks, process the chunks, then discard them from memory.

See the answer on reading line by line with perl if that's what you need.

How do I find the absolute position of an element using jQuery?

Note that $(element).offset() tells you the position of an element relative to the document. This works great in most circumstances, but in the case of position:fixed you can get unexpected results.

If your document is longer than the viewport and you have scrolled vertically toward the bottom of the document, then your position:fixed element's offset() value will be greater than the expected value by the amount you have scrolled.

If you are looking for a value relative to the viewport (window), rather than the document on a position:fixed element, you can subtract the document's scrollTop() value from the fixed element's offset().top value. Example: $("#el").offset().top - $(document).scrollTop()

If the position:fixed element's offset parent is the document, you want to read parseInt($.css('top')) instead.

Convert String value format of YYYYMMDDHHMMSS to C# DateTime

You have to use a custom parsing string. I also suggest to include the invariant culture to identify that this format does not relate to any culture. Plus, it will prevent a warning in some code analysis tools.

var date = DateTime.ParseExact(value, "yyyyMMddHHmmss", CultureInfo.InvariantCulture);

PHP Echo a large block of text

Heredoc syntax can be very useful:

// start the string with 3 <'s and then a word
// it doesn't have to be any particular string or length
// but it's common to make it in all caps.
echo <<< EOT
    in here is your string
    it has the same variable substitution rules
    as a double quoted string.
    when you end it, put the indicator word at the
    start of the line (no spaces before it)
    and put a semicolon after it
EOT;

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

create below stored procedure in your db(from which db u want to delete sp's)

then right click on that procedure - click on Execute Stored Procedure..

then click ok.

create Procedure [dbo].[DeleteAllProcedures]
As 
declare @schemaName varchar(500)    
declare @procName varchar(500)
declare cur cursor
for select s.Name, p.Name from sys.procedures p
INNER JOIN sys.schemas s ON p.schema_id = s.schema_id
WHERE p.type = 'P' and is_ms_shipped = 0 and p.name not like 'sp[_]%diagram%'
ORDER BY s.Name, p.Name
open cur

fetch next from cur into @schemaName,@procName
while @@fetch_status = 0
begin
if @procName <> 'DeleteAllProcedures'
exec('drop procedure ' + @schemaName + '.' + @procName)
fetch next from cur into @schemaName,@procName
end
close cur
deallocate cur

Why use #ifndef CLASS_H and #define CLASS_H in .h file but not in .cpp?

That's the distinction between declaration and definition. Header files typically include just the declaration, and the source file contains the definition.

In order to use something you only need to know it's declaration not it's definition. Only the linker needs to know the definition.

So this is why you will include a header file inside one or more source files but you won't include a source file inside another.

Also you mean #include and not import.

How to add checkboxes to JTABLE swing

1) JTable knows JCheckbox with built-in Boolean TableCellRenderers and TableCellEditor by default, then there is contraproductive declare something about that,

2) AbstractTableModel should be useful, where is in the JTable required to reduce/restrict/change nested and inherits methods by default implemented in the DefaultTableModel,

3) consider using DefaultTableModel, (if you are not sure about how to works) instead of AbstractTableModel,

table_with_BooleanType_column

could be generated from simple code:

import javax.swing.*;
import javax.swing.table.*;

public class TableCheckBox extends JFrame {

    private static final long serialVersionUID = 1L;
    private JTable table;

    public TableCheckBox() {
        Object[] columnNames = {"Type", "Company", "Shares", "Price", "Boolean"};
        Object[][] data = {
            {"Buy", "IBM", new Integer(1000), new Double(80.50), false},
            {"Sell", "MicroSoft", new Integer(2000), new Double(6.25), true},
            {"Sell", "Apple", new Integer(3000), new Double(7.35), true},
            {"Buy", "Nortel", new Integer(4000), new Double(20.00), false}
        };
        DefaultTableModel model = new DefaultTableModel(data, columnNames);
        table = new JTable(model) {

            private static final long serialVersionUID = 1L;

            /*@Override
            public Class getColumnClass(int column) {
            return getValueAt(0, column).getClass();
            }*/
            @Override
            public Class getColumnClass(int column) {
                switch (column) {
                    case 0:
                        return String.class;
                    case 1:
                        return String.class;
                    case 2:
                        return Integer.class;
                    case 3:
                        return Double.class;
                    default:
                        return Boolean.class;
                }
            }
        };
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        JScrollPane scrollPane = new JScrollPane(table);
        getContentPane().add(scrollPane);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                TableCheckBox frame = new TableCheckBox();
                frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
                frame.pack();
                frame.setLocation(150, 150);
                frame.setVisible(true);
            }
        });
    }
}

How to correctly get image from 'Resources' folder in NetBeans

I have a slightly different approach that might be useful/more beneficial to some.

Under your main project folder, create a resource folder. Your folder structure should look something like this.

  • Project Folder
    • build
    • dist
    • lib
    • nbproject
    • resources
    • src

Go to the properties of your project. You can do this by right clicking on your project in the Projects tab window and selecting Properties in the drop down menu.

Under categories on the left side, select Sources.

In Source Package Folders on the right side, add your resource folder using the Add Folder button. Once you click OK, you should see a Resources folder under your project.

enter image description here

You should now be able to pull resources using this line or similar approach:

MyClass.class.getResource("/main.jpg");

If you were to create a package called Images under the resources folder, you can retrieve the resource like this:

MyClass.class.getResource("/Images/main.jpg");

Getting value from JQUERY datepicker

$('div#someID').datepicker({
   onSelect: function(dateText, inst) { alert(dateText); }
});

you must bind it to input element only

FutureWarning: elementwise comparison failed; returning scalar, but in the future will perform elementwise comparison

I've compared a few of the methods possible for doing this, including pandas, several numpy methods, and a list comprehension method.

First, let's start with a baseline:

>>> import numpy as np
>>> import operator
>>> import pandas as pd

>>> x = [1, 2, 1, 2]
>>> %time count = np.sum(np.equal(1, x))
>>> print("Count {} using numpy equal with ints".format(count))
CPU times: user 52 µs, sys: 0 ns, total: 52 µs
Wall time: 56 µs
Count 2 using numpy equal with ints

So, our baseline is that the count should be correct 2, and we should take about 50 us.

Now, we try the naive method:

>>> x = ['s', 'b', 's', 'b']
>>> %time count = np.sum(np.equal('s', x))
>>> print("Count {} using numpy equal".format(count))
CPU times: user 145 µs, sys: 24 µs, total: 169 µs
Wall time: 158 µs
Count NotImplemented using numpy equal
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/ipykernel_launcher.py:1: FutureWarning: elementwise comparison failed; returning scalar instead, but in the future will perform elementwise comparison
  """Entry point for launching an IPython kernel.

And here, we get the wrong answer (NotImplemented != 2), it takes us a long time, and it throws the warning.

So we'll try another naive method:

>>> %time count = np.sum(x == 's')
>>> print("Count {} using ==".format(count))
CPU times: user 46 µs, sys: 1 µs, total: 47 µs
Wall time: 50.1 µs
Count 0 using ==

Again, the wrong answer (0 != 2). This is even more insidious because there's no subsequent warnings (0 can be passed around just like 2).

Now, let's try a list comprehension:

>>> %time count = np.sum([operator.eq(_x, 's') for _x in x])
>>> print("Count {} using list comprehension".format(count))
CPU times: user 55 µs, sys: 1 µs, total: 56 µs
Wall time: 60.3 µs
Count 2 using list comprehension

We get the right answer here, and it's pretty fast!

Another possibility, pandas:

>>> y = pd.Series(x)
>>> %time count = np.sum(y == 's')
>>> print("Count {} using pandas ==".format(count))
CPU times: user 453 µs, sys: 31 µs, total: 484 µs
Wall time: 463 µs
Count 2 using pandas ==

Slow, but correct!

And finally, the option I'm going to use: casting the numpy array to the object type:

>>> x = np.array(['s', 'b', 's', 'b']).astype(object)
>>> %time count = np.sum(np.equal('s', x))
>>> print("Count {} using numpy equal".format(count))
CPU times: user 50 µs, sys: 1 µs, total: 51 µs
Wall time: 55.1 µs
Count 2 using numpy equal

Fast and correct!

ASP.NET Core 1.0 on IIS error 502.5

For me it was that the connectionString in Startup.cs was null in:

services.AddDbContext<ApplicationDbContext>(options => options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));

and it was null because the application was not looking into appsettings.json for the connection string.

Had to change Program.cs to:

public static void Main(string[] args)
{
    BuildWebHost(args).Run();
}

public static IWebHost BuildWebHost(string[] args) =>
     WebHost.CreateDefaultBuilder(args)
     .ConfigureAppConfiguration((context, builder) => builder.SetBasePath(context.HostingEnvironment.ContentRootPath)
     .AddJsonFile("appsettings.json").Build())
     .UseStartup<Startup>().Build();

Regular Expression for any number greater than 0?

You can use the below expression:

(^\d*\.?\d*[1-9]+\d*$)|(^[1-9]+\.?\d*$)                  

Valid entries: 1 1. 1.1 1.0 all positive real numbers

Invalid entries: all negative real numbers and 0 and 0.0

Connecting to MySQL from Android with JDBC

try changing in the gradle file the targetSdkVersion to 8

targetSdkVersion 8

How to execute my SQL query in CodeIgniter

http://www.bsourcecode.com/codeigniter/codeigniter-select-query/

$query = $this->db->query("select * from tbl_user");

OR

$query = $this->db->select("*");
            $this->db->from('table_name');
            $query=$this->db->get();

Bug? #1146 - Table 'xxx.xxxxx' doesn't exist

Recently I had same problem, but on Linux Server. Database was crashed, and I recovered it from backup, based on simply copying /var/lib/mysql/* (analog mysql DATA folder in wamp). After recovery I had to create new table and got mysql error #1146. I tried to restart mysql, and it said it could not start. I checked mysql logs, and found that mysql simply had no access rigths to its DB files. I checked owner info of /var/lib/mysql/*, and got 'myuser:myuser' (myuser is me). But it should be 'mysql:adm' (so is own developer machine), so I changed owner to 'mysql:adm'. And after this mysql started normally, and I could create tables, or do any other operations.

So after moving database files or restoring from backups check access rigths for mysql.

Hope this helps...

Bootstrap 3 scrollable div for table

A scrolling comes from a box with class pre-scrollable

<div class="pre-scrollable"></div>

There's more examples: http://getbootstrap.com/css/#code-block
Wish it helps.

How can I change the color of AlertDialog title and the color of the line under it

Divider color:

It is a hack a bit, but it works great for me and it works without any external library (at least on Android 4.4).

AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setTitle(R.string.dialog)
       .setIcon(R.drawable.ic)
       .setMessage(R.string.dialog_msg);
//The tricky part
Dialog d = builder.show();
int dividerId = d.getContext().getResources().getIdentifier("android:id/titleDivider", null, null);
View divider = d.findViewById(dividerId);
divider.setBackgroundColor(getResources().getColor(R.color.my_color));

You can find more dialog's ids in alert_dialog.xml file. Eg. android:id/alertTitle for changing title color...

UPDATE: Title color

Hack for changing title color:

int textViewId = d.getContext().getResources().getIdentifier("android:id/alertTitle", null, null);
TextView tv = (TextView) d.findViewById(textViewId);
tv.setTextColor(getResources().getColor(R.color.my_color));

How to find the Number of CPU Cores via .NET/C#?

One option would be to read the data from the registry. MSDN Article On The Topic: http://msdn.microsoft.com/en-us/library/microsoft.win32.registry.localmachine(v=vs.71).aspx)

The processors, I believe can be located here, HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor

    private void determineNumberOfProcessCores()
    {
        RegistryKey rk = Registry.LocalMachine;
        String[] subKeys = rk.OpenSubKey("HARDWARE").OpenSubKey("DESCRIPTION").OpenSubKey("System").OpenSubKey("CentralProcessor").GetSubKeyNames();

        textBox1.Text = "Total number of cores:" + subKeys.Length.ToString();
    }

I am reasonably sure the registry entry will be there on most systems.

Though I would throw my $0.02 in.

Where does PHP's error log reside in XAMPP?

For mac users XAMPP Version 1.7.3

/Applications/XAMPP/xamppfiles/logs/error_log

VBA code to show Message Box popup if the formula in the target cell exceeds a certain value

I don't think a message box is the best way to go with this as you would need the VB code running in a loop to check the cell contents, or unless you plan to run the macro manually. In this case I think it would be better to add conditional formatting to the cell to change the background to red (for example) if the value exceeds the upper limit.

Deleting a local branch with Git

Switch to some other branch and delete Test_Branch, as follows:

$ git checkout master
$ git branch -d Test_Branch

If above command gives you error - The branch 'Test_Branch' is not fully merged. If you are sure you want to delete it and still you want to delete it, then you can force delete it using -D instead of -d, as:

$ git branch -D Test_Branch

To delete Test_Branch from remote as well, execute:

git push origin --delete Test_Branch

jquery multiple checkboxes array

A global function that can be reused:

function getCheckedGroupBoxes(groupName) {

    var checkedAry= [];
    $.each($("input[name='" + groupName + "']:checked"), function () {
        checkedAry.push($(this).attr("id"));
    });

     return checkedAry;

}

where the groupName is the name of the group of the checkboxes, in you example :'options[]'

How to use activity indicator view on iPhone?

in regards to:

Take a look at the open source WordPress application. They have a very re-usable window they have created for displaying an "activity in progress" type display over top of whatever view your application is currently displaying.

note that if you do utilise this code you MUST provide ALL the sourcecode to your own application to any user that requests it. You need to be aware that they may decide to repackage your code and sell it on the store themselves. This is all provided for under the terms of the GNU General Public License (GPL).

If you don't want to be forced into opening your sourcecode then you cannot use anything from the wordpress iphone application including the, referenced activity progress window, without forcing the GPL to apply to your own.

How to change the default charset of a MySQL table?

The ALTER TABLE MySQL command should do the trick. The following command will change the default character set of your table and the character set of all its columns to UTF8.

ALTER TABLE etape_prospection CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;

This command will convert all text-like columns in the table to the new character set. Character sets use different amounts of data per character, so MySQL will convert the type of some columns to ensure there's enough room to fit the same number of characters as the old column type.

I recommend you read the ALTER TABLE MySQL documentation before modifying any live data.

How to clear File Input

This works to

 $("#yourINPUTfile").val("");

Remove Item in Dictionary based on Value

Are you trying to remove a single value or all matching values?

If you are trying to remove a single value, how do you define the value you wish to remove?

The reason you don't get a key back when querying on values is because the dictionary could contain multiple keys paired with the specified value.

If you wish to remove all matching instances of the same value, you can do this:

foreach(var item in dic.Where(kvp => kvp.Value == value).ToList())
{
    dic.Remove(item.Key);
}

And if you wish to remove the first matching instance, you can query to find the first item and just remove that:

var item = dic.First(kvp => kvp.Value == value);

dic.Remove(item.Key);

Note: The ToList() call is necessary to copy the values to a new collection. If the call is not made, the loop will be modifying the collection it is iterating over, causing an exception to be thrown on the next attempt to iterate after the first value is removed.

Xcode iOS 8 Keyboard types not supported

iOS Simulator -> I/O -> Keyboard -> Connect Hardware Keyboard

I was facing similar issues but above flow chart is the fix for your issue.

Entity Framework: One Database, Multiple DbContexts. Is this a bad idea?

Reminder: If you do combine multiple contexts make sure you cut n paste all the functionality in your various RealContexts.OnModelCreating() into your single CombinedContext.OnModelCreating().

I just wasted time hunting down why my cascade delete relationships weren't being preserved only to discover that I hadn't ported the modelBuilder.Entity<T>()....WillCascadeOnDelete(); code from my real context into my combined context.

error C2039: 'string' : is not a member of 'std', header file problem

Your FMAT.h requires a definition of std::string in order to complete the definition of class FMAT. In FMAT.cpp, you've done this by #include <string> before #include "FMAT.h". You haven't done that in your main file.

Your attempt to forward declare string was incorrect on two levels. First you need a fully qualified name, std::string. Second this works only for pointers and references, not for variables of the declared type; a forward declaration doesn't give the compiler enough information about what to embed in the class you're defining.

How do I make a Windows batch script completely silent?

If you want that all normal output of your Batch script be silent (like in your example), the easiest way to do that is to run the Batch file with a redirection:

C:\Temp> test.bat >nul

This method does not require to modify a single line in the script and it still show error messages in the screen. To supress all the output, including error messages:

C:\Temp> test.bat >nul 2>&1

If your script have lines that produce output you want to appear in screen, perhaps will be simpler to add redirection to those lineas instead of all the lines you want to keep silent:

@ECHO OFF
SET scriptDirectory=%~dp0
COPY %scriptDirectory%test.bat %scriptDirectory%test2.bat
FOR /F %%f IN ('dir /B "%scriptDirectory%*.noext"') DO (
del "%scriptDirectory%%%f"
)
ECHO
REM Next line DO appear in the screen
ECHO Script completed >con

Antonio

Jquery .on('scroll') not firing the event while scrolling

I know that this is quite old thing, but I solved issue like that: I had parent and child element was scrollable.

   if ($('#parent > *').length == 0 ){
        var wait = setInterval(function() {
            if($('#parent > *').length != 0 ) {
                $('#parent .child').bind('scroll',function() {
                  //do staff
                });
                clearInterval(wait);
            },1000);
        }

The issue I had is that I didn't know when the child is loaded to DOM, but I kept checking for it every second.

NOTE:this is useful if it happens soon but not right after document load, otherwise it will use clients computing power for no reason.