Programs & Examples On #Txf

TxF is an abbreviation for “transactional NTFS”.

Why does C++ code for testing the Collatz conjecture run faster than hand-written assembly?

On a rather unrelated note: more performance hacks!

  • [the first «conjecture» has been finally debunked by @ShreevatsaR; removed]

  • When traversing the sequence, we can only get 3 possible cases in the 2-neighborhood of the current element N (shown first):

    1. [even] [odd]
    2. [odd] [even]
    3. [even] [even]

    To leap past these 2 elements means to compute (N >> 1) + N + 1, ((N << 1) + N + 1) >> 1 and N >> 2, respectively.

    Let`s prove that for both cases (1) and (2) it is possible to use the first formula, (N >> 1) + N + 1.

    Case (1) is obvious. Case (2) implies (N & 1) == 1, so if we assume (without loss of generality) that N is 2-bit long and its bits are ba from most- to least-significant, then a = 1, and the following holds:

    (N << 1) + N + 1:     (N >> 1) + N + 1:
    
            b10                    b1
             b1                     b
           +  1                   + 1
           ----                   ---
           bBb0                   bBb
    

    where B = !b. Right-shifting the first result gives us exactly what we want.

    Q.E.D.: (N & 1) == 1 ? (N >> 1) + N + 1 == ((N << 1) + N + 1) >> 1.

    As proven, we can traverse the sequence 2 elements at a time, using a single ternary operation. Another 2× time reduction.

The resulting algorithm looks like this:

uint64_t sequence(uint64_t size, uint64_t *path) {
    uint64_t n, i, c, maxi = 0, maxc = 0;

    for (n = i = (size - 1) | 1; i > 2; n = i -= 2) {
        c = 2;
        while ((n = ((n & 3)? (n >> 1) + n + 1 : (n >> 2))) > 2)
            c += 2;
        if (n == 2)
            c++;
        if (c > maxc) {
            maxi = i;
            maxc = c;
        }
    }
    *path = maxc;
    return maxi;
}

int main() {
    uint64_t maxi, maxc;

    maxi = sequence(1000000, &maxc);
    printf("%llu, %llu\n", maxi, maxc);
    return 0;
}

Here we compare n > 2 because the process may stop at 2 instead of 1 if the total length of the sequence is odd.

[EDIT:]

Let`s translate this into assembly!

MOV RCX, 1000000;



DEC RCX;
AND RCX, -2;
XOR RAX, RAX;
MOV RBX, RAX;

@main:
  XOR RSI, RSI;
  LEA RDI, [RCX + 1];

  @loop:
    ADD RSI, 2;
    LEA RDX, [RDI + RDI*2 + 2];
    SHR RDX, 1;
    SHRD RDI, RDI, 2;    ror rdi,2   would do the same thing
    CMOVL RDI, RDX;      Note that SHRD leaves OF = undefined with count>1, and this doesn't work on all CPUs.
    CMOVS RDI, RDX;
    CMP RDI, 2;
  JA @loop;

  LEA RDX, [RSI + 1];
  CMOVE RSI, RDX;

  CMP RAX, RSI;
  CMOVB RAX, RSI;
  CMOVB RBX, RCX;

  SUB RCX, 2;
JA @main;



MOV RDI, RCX;
ADD RCX, 10;
PUSH RDI;
PUSH RCX;

@itoa:
  XOR RDX, RDX;
  DIV RCX;
  ADD RDX, '0';
  PUSH RDX;
  TEST RAX, RAX;
JNE @itoa;

  PUSH RCX;
  LEA RAX, [RBX + 1];
  TEST RBX, RBX;
  MOV RBX, RDI;
JNE @itoa;

POP RCX;
INC RDI;
MOV RDX, RDI;

@outp:
  MOV RSI, RSP;
  MOV RAX, RDI;
  SYSCALL;
  POP RAX;
  TEST RAX, RAX;
JNE @outp;

LEA RAX, [RDI + 59];
DEC RDI;
SYSCALL;

Use these commands to compile:

nasm -f elf64 file.asm
ld -o file file.o

See the C and an improved/bugfixed version of the asm by Peter Cordes on Godbolt. (editor's note: Sorry for putting my stuff in your answer, but my answer hit the 30k char limit from Godbolt links + text!)

LDAP: error code 49 - 80090308: LdapErr: DSID-0C0903A9, comment: AcceptSecurityContext error, data 52e, v1db1

Using domain Name may solve the problem (get domain name using powershell: $env:userdomain):

    Hashtable<String, Object> env = new Hashtable<String, Object>();
    String principalName = "domainName\\userName";
    env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
    env.put(Context.PROVIDER_URL, "ldap://URL:389/OU=ou-xx,DC=fr,DC=XXXXXX,DC=com");
    env.put(Context.SECURITY_AUTHENTICATION, "simple");
    env.put(Context.SECURITY_PRINCIPAL, principalName);
    env.put(Context.SECURITY_CREDENTIALS, "Your Password");

    try {
        DirContext authContext = new InitialDirContext(env);
        // user is authenticated
        System.out.println("USER IS AUTHETICATED");
    } catch (AuthenticationException ex) {
        // Authentication failed
        System.out.println("AUTH FAILED : " + ex);

    } catch (NamingException ex) {
        ex.printStackTrace();
    }

LDAP Authentication using Java

Following Code authenticates from LDAP using pure Java JNDI. The Principle is:-

  1. First Lookup the user using a admin or DN user.
  2. The user object needs to be passed to LDAP again with the user credential
  3. No Exception means - Authenticated Successfully. Else Authentication Failed.

Code Snippet

public static boolean authenticateJndi(String username, String password) throws Exception{
    Properties props = new Properties();
    props.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
    props.put(Context.PROVIDER_URL, "ldap://LDAPSERVER:PORT");
    props.put(Context.SECURITY_PRINCIPAL, "uid=adminuser,ou=special users,o=xx.com");//adminuser - User with special priviledge, dn user
    props.put(Context.SECURITY_CREDENTIALS, "adminpassword");//dn user password


    InitialDirContext context = new InitialDirContext(props);

    SearchControls ctrls = new SearchControls();
    ctrls.setReturningAttributes(new String[] { "givenName", "sn","memberOf" });
    ctrls.setSearchScope(SearchControls.SUBTREE_SCOPE);

    NamingEnumeration<javax.naming.directory.SearchResult> answers = context.search("o=xx.com", "(uid=" + username + ")", ctrls);
    javax.naming.directory.SearchResult result = answers.nextElement();

    String user = result.getNameInNamespace();

    try {
        props = new Properties();
        props.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
        props.put(Context.PROVIDER_URL, "ldap://LDAPSERVER:PORT");
        props.put(Context.SECURITY_PRINCIPAL, user);
        props.put(Context.SECURITY_CREDENTIALS, password);

   context = new InitialDirContext(props);
    } catch (Exception e) {
        return false;
    }
    return true;
}

how to save canvas as png image?

try this:

var c=document.getElementById("alpha");
var d=c.toDataURL("image/png");
var w=window.open('about:blank','image from canvas');
w.document.write("<img src='"+d+"' alt='from canvas'/>");

This shows image from canvas on new page, but if you have open popup in new tab setting it shows about:blank in address bar.

EDIT:- though window.open("<img src='"+ c.toDataURL('image/png') +"'/>") does not work in FF or Chrome, following works though rendering is somewhat different from what is shown on canvas, I think transparency is the issue:

window.open(c.toDataURL('image/png'));

what does this mean ? image/png;base64?

It's an inlined image (png), encoded in base64. It can make a page faster: the browser doesn't have to query the server for the image data separately, saving a round trip.

(It can also make it slower if abused: these resources are not cached, so the bytes are included in each page load.)

How do a LDAP search/authenticate against this LDAP in Java

try {
    LdapContext ctx = new InitialLdapContext(env, null);
    ctx.setRequestControls(null);
    NamingEnumeration<?> namingEnum = ctx.search("ou=people,dc=example,dc=com", "(objectclass=user)", getSimpleSearchControls());
    while (namingEnum.hasMore ()) {
        SearchResult result = (SearchResult) namingEnum.next ();    
        Attributes attrs = result.getAttributes ();
        System.out.println(attrs.get("cn"));

    } 
    namingEnum.close();
} catch (Exception e) {
    e.printStackTrace();
}

private SearchControls getSimpleSearchControls() {
    SearchControls searchControls = new SearchControls();
    searchControls.setSearchScope(SearchControls.SUBTREE_SCOPE);
    searchControls.setTimeLimit(30000);
    //String[] attrIDs = {"objectGUID"};
    //searchControls.setReturningAttributes(attrIDs);
    return searchControls;
}

How to run .jar file by double click on Windows 7 64-bit?

change the default application for JAR files from java.exe to javaw.exe from your JAVA_HOME/bin folder.

This is because, java.exe is console application only, but JAR file needs a window rendered execution. Since javaw.exe is a window application, it is preferred for the execution of JAR files.

An alternative to this is that to some extent you can use command prompt to run your JAR files by simply using java keyword with -jar attrib.

SQL Server SELECT into existing table

There are two different ways to implement inserting data from one table to another table.

For Existing Table - INSERT INTO SELECT

This method is used when the table is already created in the database earlier and the data is to be inserted into this table from another table. If columns listed in insert clause and select clause are same, they are not required to list them. It is good practice to always list them for readability and scalability purpose.

----Create testable
CREATE TABLE TestTable (FirstName VARCHAR(100), LastName VARCHAR(100))
----INSERT INTO TestTable using SELECT
INSERT INTO TestTable (FirstName, LastName)
SELECT FirstName, LastName
FROM Person.Contact
WHERE EmailPromotion = 2
----Verify that Data in TestTable
SELECT FirstName, LastName
FROM TestTable
----Clean Up Database
DROP TABLE TestTable

For Non-Existing Table - SELECT INTO

This method is used when the table is not created earlier and needs to be created when data from one table is to be inserted into the newly created table from another table. The new table is created with the same data types as selected columns.

----Create a new table and insert into table using SELECT INSERT
SELECT FirstName, LastName
INTO TestTable
FROM Person.Contact
WHERE EmailPromotion = 2
----Verify that Data in TestTable
SELECT FirstName, LastName
FROM TestTable
----Clean Up Database
DROP TABLE TestTable

Ref 1 2

Jquery change background color

This is how it should be:

Code:

$(function(){
  $("button").mouseover(function(){
    var $p = $("#P44");
    $p.stop()
      .css("background-color","yellow")
      .hide(1500, function() {
          $p.css("background-color","red")
            .show(1500);
      });
  });
});

Demo: http://jsfiddle.net/p7w9W/2/

Explanation:

You have to wait for the callback on the animating functions before you switch background color. You should also not use only numeric ID:s, and if you have an ID of your <p> there you shouldn't include a class in your selector.

I also enhanced your code (caching of the jQuery object, chaining, etc.)

Update: As suggested by VKolev the color is now changing when the item is hidden.

How does Facebook Sharer select Images and other metadata when sharing my URL?

This is what worked for me: I placed the desired thumbnail image on the page right after the tag and making it too small to see..

<img src="imagename.jpg" width="1" height="1" />

I have not tested it with height 0 and width 0 but it probably will still work.. This does not guarantee the user will select this image..

ALSO it seems like Facebook caches the thumbnails on your page and doesnt always check it for new ones.. try adding this to another page on your site and you'll see that it works.

What is JavaScript's highest integer value that a number can go to without losing precision?

>= ES6:

Number.MIN_SAFE_INTEGER;
Number.MAX_SAFE_INTEGER;

<= ES5

From the reference:

Number.MAX_VALUE;
Number.MIN_VALUE;

_x000D_
_x000D_
console.log('MIN_VALUE', Number.MIN_VALUE);
console.log('MAX_VALUE', Number.MAX_VALUE);

console.log('MIN_SAFE_INTEGER', Number.MIN_SAFE_INTEGER); //ES6
console.log('MAX_SAFE_INTEGER', Number.MAX_SAFE_INTEGER); //ES6
_x000D_
_x000D_
_x000D_

git push says "everything up-to-date" even though I have local changes

Another very simple yet noobish mistake of mine: I simply forgot to add a message -m modifier in my commit. So I wrote:

git commit 'My message'

Instead of correct:

git commit -m 'My message'

NOTE: It does NOT throw any errors! But you will not be able to push your commits and always get Everything up to date instead

Example using Hyperlink in WPF

I used the answer in this question and I got an issue with it.

It return exception: {"The system cannot find the file specified."}

After a bit of investigation. It turns out that if your WPF application is CORE, you need to change UseShellExecute to true.

This is mentioned in Microsoft docs:

true if the shell should be used when starting the process; false if the process should be created directly from the executable file. The default is true on .NET Framework apps and false on .NET Core apps.

So to make this work you need to added UseShellExecute and set it to true:

Process.Start(new ProcessStartInfo(e.Uri.AbsoluteUri){ UseShellExecute = true });

JavaScript: location.href to open in new window/tab?

Pure js alternative to window.open

let a= document.createElement('a');
a.target= '_blank';
a.href= 'https://support.wwf.org.uk/';
a.click();

here is working example (stackoverflow snippets not allow to opening)

Finding the second highest number in array

Problem: The problem is to get the second largest array element.

Observation: Second largest number is defined as the number that has the minimum difference when subtracted from the maximum element in the array.

Solution: This is a two pass solution. First pass is to find the maximum number. Second pass is to find the element that has minimum difference with the maximum element as compared to other array elements. Example: In the array [2, 3, 6, 6, 5] maximum = 6 and second maximum = 5 , since it has the minimum difference to the maximum element 6 - 5 = 1 the solution for second largest = 5

function printSecondMax(myArray) {
  var x, max = myArray[0];
  // Find maximum element 
  for(x in myArray){
     if(max < myArray[x]){
        max = myArray[x];
     }
  }
  var secondMax = myArray[0], diff = max - secondMax;
  // Find second max, an element that has min diff with the max
  for(x in myArray){
    if(diff != 0 && (max - myArray[x]) != 0 && diff > (max - myArray[x])){
        secondMax = myArray[x];
        diff = max - secondMax;
    }
  }
  console.log(secondMax);
}

Complexity : O(n), This is the simplest way to do this.

For finding maximum element even more efficiently one can look into max heap, a call to max-heapify will take O(log n) time to find the max and then pop-ing the top element gives maximum. To get the second maximum, max-heapify after pop-ing the top and keep pop-ing till you get a number that is less than maximum. That will be the second maximum. This solution has O(n log n) complexity.

Difference between Divide and Conquer Algo and Dynamic Programming

  • Divide and Conquer
    • They broke into non-overlapping sub-problems
    • Example: factorial numbers i.e. fact(n) = n*fact(n-1)
fact(5) = 5* fact(4) = 5 * (4 * fact(3))= 5 * 4 * (3 *fact(2))= 5 * 4 * 3 * 2 * (fact(1))

As we can see above, no fact(x) is repeated so factorial has non overlapping problems.

  • Dynamic Programming
    • They Broke into overlapping sub-problems
    • Example: Fibonacci numbers i.e. fib(n) = fib(n-1) + fib(n-2)
fib(5) = fib(4) + fib(3) = (fib(3)+fib(2)) + (fib(2)+fib(1))

As we can see above, fib(4) and fib(3) both use fib(2). similarly so many fib(x) gets repeated. that's why Fibonacci has overlapping sub-problems.

  • As a result of the repetition of sub-problem in DP, we can keep such results in a table and save computation effort. this is called as memoization

Program does not contain a static 'Main' method suitable for an entry point

You can also run into this if you're working on a WPF project that was started in VS 2010 (Beta 1), then moved into VS 2008.

Under the project properties, the .NET framework version gets unset (since .NET 4.0 isn't valid in VS 2008), and for some reason that causes this error.

If you set the .NET framework (e.g. to .NET 3.5), the error goes away.

Angular File Upload

This way I implement upload file to web API in project.

I share for whom concern.

const formData: FormData = new FormData();
formData.append('Image', image, image.name);
formData.append('ComponentId', componentId);
return this.http.post('/api/dashboard/UploadImage', formData);

Step by step

ASP.NET Web API

[HttpPost]
[Route("api/dashboard/UploadImage")]
public HttpResponseMessage UploadImage() 
{
    string imageName = null;
    var httpRequest = HttpContext.Current.Request;
    //Upload Image
    var postedFile = httpRequest.Files["Image"];
    //Create custom filename
    if (postedFile != null)
    {
        imageName = new String(Path.GetFileNameWithoutExtension(postedFile.FileName).Take(10).ToArray()).Replace(" ", "-");
        imageName = imageName + DateTime.Now.ToString("yymmssfff") + Path.GetExtension(postedFile.FileName);
        var filePath = HttpContext.Current.Server.MapPath("~/Images/" + imageName);
        postedFile.SaveAs(filePath);
    }
}

HTML form

<form #imageForm=ngForm (ngSubmit)="OnSubmit(Image)">

    <img [src]="imageUrl" class="imgArea">
    <div class="image-upload">
        <label for="file-input">
            <img src="upload.jpg" />
        </label>

        <input id="file-input" #Image type="file" (change)="handleFileInput($event.target.files)" />
        <button type="submit" class="btn-large btn-submit" [disabled]="Image.value=='' || !imageForm.valid"><i
                class="material-icons">save</i></button>
    </div>
</form>

TS file to use API

OnSubmit(Image) {
    this.dashboardService.uploadImage(this.componentId, this.fileToUpload).subscribe(
      data => {
        console.log('done');
        Image.value = null;
        this.imageUrl = "/assets/img/logo.png";
      }
    );
  }

Service TS

uploadImage(componentId, image) {
        const formData: FormData = new FormData();
        formData.append('Image', image, image.name);
        formData.append('ComponentId', componentId);
        return this.http.post('/api/dashboard/UploadImage', formData);
    }

Java output formatting for Strings

If you want a minimum of 4 characters, for instance,

System.out.println(String.format("%4d", 5));
// Results in "   5", minimum of 4 characters

flutter corner radius with transparent background

showModalBottomSheet(
   context: context,
   builder: (context) => Container(
            color: Color(0xff757575), //background color 
            child:  new Container(
                decoration: new BoxDecoration(
                    color: Colors.blue,
                    borderRadius: new BorderRadius.only(
                        topLeft:  const  Radius.circular(40.0),
                        topRight: const  Radius.circular(40.0))
                ),
              child: new Center(
                child: new Text("Hi modal sheet"),
              )

     

 ),

)

This is will make your container color the same as the background color. And there will be a child container of the same height-width with blue color. This will make the corner with the same color as the background color.

Change the Textbox height?

I know this is a kind of old post, but I found myself in this same issue, and by investigating a bit I found out that the Height of a WinForms TextBox is actually calculated depending on the size of the font it contains, it's just not quite equal to it.

This guy explains how the calculation is done, and how you can set it on your TextBox to get the desired Height.

Cheers!

Open window in JavaScript with HTML inserted

I would not recomend you to use document.write as others suggest, because if you will open such window twice your HTML will be duplicated 2 times (or more).

Use innerHTML instead

var win = window.open("", "Title", "toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes,width=780,height=200,top="+(screen.height-400)+",left="+(screen.width-840));
win.document.body.innerHTML = "HTML";

How do I create a shortcut via command-line in Windows?

I present a small hybrid script [BAT/VBS] to create a desktop shortcut. And you can of course modifie it to your purpose.

@echo off
mode con cols=87 lines=5 & color 9B
Title Shortcut Creator for your batch and applications files by Hackoo 2015
Set MyFile=%~f0
Set ShorcutName=HackooTest
(
echo Call Shortcut("%MyFile%","%ShorcutName%"^)
echo ^'**********************************************************************************************^)
echo Sub Shortcut(ApplicationPath,Nom^)
echo    Dim objShell,DesktopPath,objShortCut,MyTab
echo    Set objShell = CreateObject("WScript.Shell"^)
echo    MyTab = Split(ApplicationPath,"\"^)
echo    If Nom = "" Then
echo    Nom = MyTab(UBound(MyTab^)^)
echo    End if
echo    DesktopPath = objShell.SpecialFolders("Desktop"^)
echo    Set objShortCut = objShell.CreateShortcut(DesktopPath ^& "\" ^& Nom ^& ".lnk"^)
echo    objShortCut.TargetPath = Dblquote(ApplicationPath^)
echo    ObjShortCut.IconLocation = "Winver.exe,0"
echo    objShortCut.Save
echo End Sub
echo ^'**********************************************************************************************
echo ^'Fonction pour ajouter les doubles quotes dans une variable
echo Function DblQuote(Str^)
echo    DblQuote = Chr(34^) ^& Str ^& Chr(34^)
echo End Function
echo ^'**********************************************************************************************
) > Shortcutme.vbs
Start /Wait Shortcutme.vbs
Del Shortcutme.vbs
::***************************************Main Batch*******************************************
cls
echo Done and your main batch goes here !
echo i am a test 
Pause > Nul
::********************************************************************************************

How can I compare a date and a datetime in Python?

Here is another take, "stolen" from a comment at can't compare datetime.datetime to datetime.date ... convert the date to a datetime using this construct:

datetime.datetime(d.year, d.month, d.day)

Suggestion:

from datetime import datetime

def ensure_datetime(d):
    """
    Takes a date or a datetime as input, outputs a datetime
    """
    if isinstance(d, datetime):
        return d
    return datetime.datetime(d.year, d.month, d.day)

def datetime_cmp(d1, d2):
    """
    Compares two timestamps.  Tolerates dates.
    """
    return cmp(ensure_datetime(d1), ensure_datetime(d2))

How do I add 1 day to an NSDate?

Use the below function and use days paramater to get the date daysAhead/daysBehind just pass parameter as positive for future date or negative for previous dates:

+ (NSDate *) getDate:(NSDate *)fromDate daysAhead:(NSUInteger)days
{
    NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
    dateComponents.day = days;
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDate *previousDate = [calendar dateByAddingComponents:dateComponents
                                                     toDate:fromDate
                                                    options:0];
    [dateComponents release];
    return previousDate;
}

Secure random token in Node.js

Look at real_ates ES2016 way, it's more correct.

ECMAScript 2016 (ES7) way

import crypto from 'crypto';

function spawnTokenBuf() {
    return function(callback) {
        crypto.randomBytes(48, callback);
    };
}

async function() {
    console.log((await spawnTokenBuf()).toString('base64'));
};

Generator/Yield Way

var crypto = require('crypto');
var co = require('co');

function spawnTokenBuf() {
    return function(callback) {
        crypto.randomBytes(48, callback);
    };
}

co(function* () {
    console.log((yield spawnTokenBuf()).toString('base64'));
});

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

A combination of peoples post gave me the date and the time for excel conversion. I did return it as a string

def xldate_to_datetime(xldate):
  tempDate = datetime.datetime(1900, 1, 1)
  deltaDays = datetime.timedelta(days=int(xldate))
  secs = (int((xldate%1)*86400)-60)
  detlaSeconds = datetime.timedelta(seconds=secs)
  TheTime = (tempDate + deltaDays + detlaSeconds )
  return TheTime.strftime("%Y-%m-%d %H:%M:%S")

Use Excel VBA to click on a button in Internet Explorer, when the button has no "name" associated

With the kind help from Tim Williams, I finally figured out the last détails that were missing. Here's the final code below.

Private Sub Open_multiple_sub_pages_from_main_page()


Dim i As Long
Dim IE As Object
Dim Doc As Object
Dim objElement As Object
Dim objCollection As Object
Dim buttonCollection As Object
Dim valeur_heure As Object


' Create InternetExplorer Object
Set IE = CreateObject("InternetExplorer.Application")
' You can uncoment Next line To see form results
IE.Visible = True

' Send the form data To URL As POST binary request
IE.navigate "http://webpage.com/"

' Wait while IE loading...
While IE.Busy
        DoEvents
Wend


Set objCollection = IE.Document.getElementsByTagName("input")

i = 0
While i < objCollection.Length
    If objCollection(i).Name = "txtUserName" Then
        ' Set text for search
        objCollection(i).Value = "1234"
    End If
    If objCollection(i).Name = "txtPwd" Then
        ' Set text for search
        objCollection(i).Value = "password"
    End If

    If objCollection(i).Type = "submit" And objCollection(i).Name = "btnSubmit" Then ' submit button if found and set
        Set objElement = objCollection(i)
    End If
    i = i + 1
Wend
objElement.Click    ' click button to load page

' Wait while IE re-loading...
While IE.Busy
        DoEvents
Wend

' Show IE
IE.Visible = True
Set Doc = IE.Document

Dim links, link

Dim j As Integer                                                                    'variable to count items
j = 0
Set links = IE.Document.getElementById("dgTime").getElementsByTagName("a")
n = links.Length
While j <= n                                    'loop to go thru all "a" item so it loads next page
    links(j).Click
    While IE.Busy
        DoEvents
    Wend
    '-------------Do stuff here:  copy field value and paste in excel sheet.  Will post another question for this------------------------
    IE.Document.getElementById("DetailToolbar1_lnkBtnSave").Click              'save
    Do While IE.Busy
        Application.Wait DateAdd("s", 1, Now)                                   'wait
    Loop
    IE.Document.getElementById("DetailToolbar1_lnkBtnCancel").Click            'close
    Do While IE.Busy
        Application.Wait DateAdd("s", 1, Now)                                   'wait
    Loop
    Set links = IE.Document.getElementById("dgTime").getElementsByTagName("a")
    j = j + 2
Wend    
End Sub

Open another application from your own (intent)

If you're attempting to start a SERVICE rather than activity, this worked for me:

Intent intent = new Intent();
intent.setClassName("com.example.otherapplication", "com.example.otherapplication.ServiceName");
context.startService(intent);

If you use the intent.setComponent(...) method as mentioned in other answers, you may get an "Implicit intents with startService are not safe" warning.

SQL query for a carriage return in a string and ultimately removing carriage return

this works: select * from table where column like '%(hit enter)%'

Ignore the brackets and hit enter to introduce new line.

Split a large pandas dataframe

You can use groupby, assuming you have an integer enumerated index:

import math
df = pd.DataFrame(dict(sample=np.arange(99)))
rows_per_subframe = math.ceil(len(df) / 4.)

subframes = [i[1] for i in df.groupby(np.arange(len(df))//rows_per_subframe)]

Note: groupby returns a tuple in which the 2nd element is the dataframe, thus the slightly complicated extraction.

>>> len(subframes), [len(i) for i in subframes]
(4, [25, 25, 25, 24])

How to disable the resize grabber of <textarea>?

example of textarea for disable the resize option

<textarea CLASS="foo"></textarea>

<style>
textarea.foo
{
resize:none;
}

</style>

How to clear all data in a listBox?

Use this:

listBox1.Items.Clear();

Wireshark localhost traffic capture

For Windows,

You cannot capture packets for Local Loopback in Wireshark however, you can use a very tiny but useful program called RawCap;

RawCap

Run RawCap on command prompt and select the Loopback Pseudo-Interface (127.0.0.1) then just write the name of the packet capture file (.pcap)

A simple demo is as below;

C:\Users\Levent\Desktop\rawcap>rawcap
Interfaces:
 0.     169.254.125.51  Local Area Connection* 12       Wireless80211
 1.     192.168.2.254   Wi-Fi   Wireless80211
 2.     169.254.214.165 Ethernet        Ethernet
 3.     192.168.56.1    VirtualBox Host-Only Network    Ethernet
 4.     127.0.0.1       Loopback Pseudo-Interface 1     Loopback
Select interface to sniff [default '0']: 4
Output path or filename [default 'dumpfile.pcap']: test.pcap
Sniffing IP : 127.0.0.1
File        : test.pcap
Packets     : 48^C

CUDA incompatible with my gcc version

For CUDA7.5 these lines work:

sudo ln -s /usr/bin/gcc-4.9 /usr/local/cuda/bin/gcc 
sudo ln -s /usr/bin/g++-4.9 /usr/local/cuda/bin/g++

Multi-character constant warnings

If you're happy you know what you're doing and can accept the portability problems, on GCC for example you can disable the warning on the command line:

-Wno-multichar

I use this for my own apps to work with AVI and MP4 file headers for similar reasons to you.

How to launch another aspx web page upon button click?

If you'd like to use Code Behind, may I suggest the following solution for an asp:button -

ASPX Page

<asp:Button ID="btnRecover" runat="server" Text="Recover" OnClick="btnRecover_Click" />

Code Behind

    protected void btnRecover_Click(object sender, EventArgs e)
    {
        var recoveryId = Guid.Parse(lbRecovery.SelectedValue);
        var url = string.Format("{0}?RecoveryId={1}", @"../Recovery.aspx", vehicleId);

        // Response.Redirect(url); // Old way

        Response.Write("<script> window.open( '" + url + "','_blank' ); </script>");
        Response.End();
    }

Get path to execution directory of Windows Forms application

Private Sub Main_Shown(sender As Object, e As EventArgs) Handles Me.Shown
    Dim args() As String = Environment.GetCommandLineArgs()
    If args.Length > 0 Then
        TextBox1.Text = Path.GetFullPath(Application.ExecutablePath)
        Process.Start(TextBox1.Text)   
    End If
End Sub

Returning boolean if set is empty

When you say:

c is not None

You are actually checking if c and None reference the same object. That is what the "is" operator does. In python None is a special null value conventionally meaning you don't have a value available. Sorta like null in c or java. Since python internally only assigns one None value using the "is" operator to check if something is None (think null) works, and it has become the popular style. However this does not have to do with the truth value of the set c, it is checking that c actually is a set rather than a null value.

If you want to check if a set is empty in a conditional statement, it is cast as a boolean in context so you can just say:

c = set()
if c:
   print "it has stuff in it"
else:
   print "it is empty"

But if you want it converted to a boolean to be stored away you can simply say:

c = set()
c_has_stuff_in_it = bool(c)

What does 'synchronized' mean?

volatile[About] => synchronized

synchronized block in Java is a monitor in multithreading. synchronized block with the same object/class can be executed by only single thread, all others are waiting. It can help with race condition situation when several threads try to update the same variable.

Java 5 extended synchronized by supporting happens-before[About]

An unlock (synchronized block or method exit) of a monitor happens-before every subsequent lock (synchronized block or method entry) of that same monitor.

The next step is java.util.concurrent

Creating a node class in Java

Welcome to Java! This Nodes are like a blocks, they must be assembled to do amazing things! In this particular case, your nodes can represent a list, a linked list, You can see an example here:

public class ItemLinkedList {
    private ItemInfoNode head;
    private ItemInfoNode tail;
    private int size = 0;

    public int getSize() {
        return size;
    }

    public void addBack(ItemInfo info) {
        size++;
        if (head == null) {
            head = new ItemInfoNode(info, null, null);
            tail = head;
        } else {
            ItemInfoNode node = new ItemInfoNode(info, null, tail);
            this.tail.next =node;
            this.tail = node;
        }
    }

    public void addFront(ItemInfo info) {
        size++;
        if (head == null) {
            head = new ItemInfoNode(info, null, null);
            tail = head;
        } else {
            ItemInfoNode node = new ItemInfoNode(info, head, null);
            this.head.prev = node;
            this.head = node;
        }
    }

    public ItemInfo removeBack() {
        ItemInfo result = null;
        if (head != null) {
            size--;
            result = tail.info;
            if (tail.prev != null) {
                tail.prev.next = null;
                tail = tail.prev;
            } else {
                head = null;
                tail = null;
            }
        }
        return result;
    }

    public ItemInfo removeFront() {
        ItemInfo result = null;
        if (head != null) {
            size--;
            result = head.info;
            if (head.next != null) {
                head.next.prev = null;
                head = head.next;
            } else {
                head = null;
                tail = null;
            }
        }
        return result;
    }

    public class ItemInfoNode {

        private ItemInfoNode next;
        private ItemInfoNode prev;
        private ItemInfo info;

        public ItemInfoNode(ItemInfo info, ItemInfoNode next, ItemInfoNode prev) {
            this.info = info;
            this.next = next;
            this.prev = prev;
        }

        public void setInfo(ItemInfo info) {
            this.info = info;
        }

        public void setNext(ItemInfoNode node) {
            next = node;
        }

        public void setPrev(ItemInfoNode node) {
            prev = node;
        }

        public ItemInfo getInfo() {
            return info;
        }

        public ItemInfoNode getNext() {
            return next;
        }

        public ItemInfoNode getPrev() {
            return prev;
        }
    }
}

EDIT:

Declare ItemInfo as this:

public class ItemInfo {
    private String name;
    private String rfdNumber;
    private double price;
    private String originalPosition;

    public ItemInfo(){
    }

    public ItemInfo(String name, String rfdNumber, double price, String originalPosition) {
        this.name = name;
        this.rfdNumber = rfdNumber;
        this.price = price;
        this.originalPosition = originalPosition;
    }

    public String getName() {
        return name;
    }

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

    public String getRfdNumber() {
        return rfdNumber;
    }

    public void setRfdNumber(String rfdNumber) {
        this.rfdNumber = rfdNumber;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public String getOriginalPosition() {
        return originalPosition;
    }

    public void setOriginalPosition(String originalPosition) {
        this.originalPosition = originalPosition;
    }
}

Then, You can use your nodes inside the linked list like this:

public static void main(String[] args) {
    ItemLinkedList list = new ItemLinkedList();
    for (int i = 1; i <= 10; i++) {
        list.addBack(new ItemInfo("name-"+i, "rfd"+i, i, String.valueOf(i)));

    }
    while (list.size() > 0){
        System.out.println(list.removeFront().getName());
    }
}

What's the main difference between int.Parse() and Convert.ToInt32

Convert.ToInt32

has 19 overloads or 19 different ways that you can call it. Maybe more in 2010 versions.

It will attempt to convert from the following TYPES;

Object, Boolean, Char, SByte, Byte, Int16, UInt16, Int32, UInt32, Int64, UInt64, Single, Double, Decimal, String, Date

and it also has a number of other methods; one to do with a number base and 2 methods involve a System.IFormatProvider

Parse on the other hand only has 4 overloads or 4 different ways you can call the method.

Integer.Parse( s As String)

Integer.Parse( s As String,  style As System.Globalization.NumberStyles )

Integer.Parse( s As String, provider As System.IFormatProvider )

Integer.Parse( s As String,  style As System.Globalization.NumberStyles, provider As System.IFormatProvider )

What is the most effective way to get the index of an iterator of an std::vector?

As UncleBens and Naveen have shown, there are good reasons for both. Which one is "better" depends on what behavior you want: Do you want to guarantee constant-time behavior, or do you want it to fall back to linear time when necessary?

it - vec.begin() takes constant time, but the operator - is only defined on random access iterators, so the code won't compile at all with list iterators, for example.

std::distance(vec.begin(), it) works for all iterator types, but will only be a constant-time operation if used on random access iterators.

Neither one is "better". Use the one that does what you need.

When should you use 'friend' in C++?

When implementing tree algorithms for class, the framework code the prof gave us had the tree class as a friend of the node class.

It doesn't really do any good, other than let you access a member variable without using a setting function.

Powershell script to check if service is started, if not then start it

[Array] $servers = "Server1","server2";
$service='YOUR SERVICE'

foreach($server in $servers)

{
    $srvc = Get-WmiObject -query "SELECT * FROM win32_service  WHERE   name LIKE '$service' " -computername $server  ;
    $res=Write-Output $srvc | Format-Table -AutoSize $server, $fmtMode, $fmtState, $fmtStatus ;  
   $srvc.startservice() 
   $res
}

Where are shared preferences stored?

Just to save some of you time...

On my Galaxy S v.2.3.3 Shared Preferences are not stored in:/data/data/YOUR_PACKAGE_NAME/shared_prefs/YOUR_PREFS_NAME.xml

but are now located in: /dbdata/databases/YOUR_PACKAGE_NAME/shared_prefs/YOUR_PREFS_NAME.xml

I believe they changed this in 2.3

Why can't Python import Image from PIL?

I had the same issue, and did this to fix it:

  1. In command prompt

    pip install Pillow ##
    
  2. Ensure that you use

    from PIL import Image
    

I in Image has to be capital. That was the issue in my case.

Unknown lifecycle phase "mvn". You must specify a valid lifecycle phase or a goal in the format <plugin-prefix>:<goal> or <plugin-group-id>

You have to specify any one of the above phase to resolve the above error. In most of the situations, this would have occurred due to running the build from the eclipse environment.

instead of mvn clean package or mvn package you can try only package its work fine for me

C++ callback using class member

Here's a concise version that works with class method callbacks and with regular function callbacks. In this example, to show how parameters are handled, the callback function takes two parameters: bool and int.

class Caller {
  template<class T> void addCallback(T* const object, void(T::* const mf)(bool,int))
  {
    using namespace std::placeholders; 
    callbacks_.emplace_back(std::bind(mf, object, _1, _2));
  }
  void addCallback(void(* const fun)(bool,int)) 
  {
    callbacks_.emplace_back(fun);
  }
  void callCallbacks(bool firstval, int secondval) 
  {
    for (const auto& cb : callbacks_)
      cb(firstval, secondval);
  }
private:
  std::vector<std::function<void(bool,int)>> callbacks_;
}

class Callee {
  void MyFunction(bool,int);
}

//then, somewhere in Callee, to add the callback, given a pointer to Caller `ptr`

ptr->addCallback(this, &Callee::MyFunction);

//or to add a call back to a regular function
ptr->addCallback(&MyRegularFunction);

This restricts the C++11-specific code to the addCallback method and private data in class Caller. To me, at least, this minimizes the chance of making mistakes when implementing it.

mkdir's "-p" option

PATH: Answered long ago, however, it maybe more helpful to think of -p as "Path" (easier to remember), as in this causes mkdir to create every part of the path that isn't already there.

mkdir -p /usr/bin/comm/diff/er/fence

if /usr/bin/comm already exists, it acts like: mkdir /usr/bin/comm/diff mkdir /usr/bin/comm/diff/er mkdir /usr/bin/comm/diff/er/fence

As you can see, it saves you a bit of typing, and thinking, since you don't have to figure out what's already there and what isn't.

ENOENT, no such file or directory

Another possibility is that you are missing an .npmrc file if you are pulling any packages that are not publicly available.

You will need to add an .npmrc file at the root directory and add the private/internal registry inside of the .npmrc file like this:

registry=http://private.package.source/secret/npm-packages/

Python: How to check if keys exists and retrieve value from Dictionary in descending priority

You can use myDict.has_key(keyname) as well to validate if the key exists.

Edit based on the comments -

This would work only on versions lower than 3.1. has_key has been removed from Python 3.1. You should use the in operator if you are using Python 3.1

How do I get ASP.NET Web API to return JSON instead of XML using Chrome?

Just add those two line of code on your WebApiConfig class

public static class WebApiConfig
{
     public static void Register(HttpConfiguration config)
     {
          //add this two line 
          config.Formatters.Clear();
          config.Formatters.Add(new JsonMediaTypeFormatter());


          ............................
      }
}

Two dimensional array in python

There aren't multidimensional arrays as such in Python, what you have is a list containing other lists.

>>> arr = [[]]
>>> len(arr)
1

What you have done is declare a list containing a single list. So arr[0] contains a list but arr[1] is not defined.

You can define a list containing two lists as follows:

arr = [[],[]]

Or to define a longer list you could use:

>>> arr = [[] for _ in range(5)]
>>> arr
[[], [], [], [], []]

What you shouldn't do is this:

arr = [[]] * 3

As this puts the same list in all three places in the container list:

>>> arr[0].append('test')
>>> arr
[['test'], ['test'], ['test']]

What's the difference between HTML 'hidden' and 'aria-hidden' attributes?

Semantic Difference

According to HTML 5.2:

When specified on an element, [the hidden attribute] indicates that the element is not yet, or is no longer, directly relevant to the page’s current state, or that it is being used to declare content to be reused by other parts of the page as opposed to being directly accessed by the user.

Examples include a tab list where some panels are not exposed, or a log-in screen that goes away after a user logs in. I like to call these things “temporally relevant” i.e. they are relevant based on timing.

On the other hand, ARIA 1.1 says:

[The aria-hidden state] indicates whether an element is exposed to the accessibility API.

In other words, elements with aria-hidden="true" are removed from the accessibility tree, which most assistive technology honors, and elements with aria-hidden="false" will definitely be exposed to the tree. Elements without the aria-hidden attribute are in the "undefined (default)" state, which means user agents should expose it to the tree based on its rendering. E.g. a user agent may decide to remove it if its text color matches its background color.

Now let’s compare semantics. It’s appropriate to use hidden, but not aria-hidden, for an element that is not yet “temporally relevant”, but that might become relevant in the future (in which case you would use dynamic scripts to remove the hidden attribute). Conversely, it’s appropriate to use aria-hidden, but not hidden, on an element that is always relevant, but with which you don’t want to clutter the accessibility API; such elements might include “visual flair”, like icons and/or imagery that are not essential for the user to consume.

Effective Difference

The semantics have predictable effects in browsers/user agents. The reason I make a distinction is that user agent behavior is recommended, but not required by the specifications.

The hidden attribute should hide an element from all presentations, including printers and screen readers (assuming these devices honor the HTML specs). If you want to remove an element from the accessibility tree as well as visual media, hidden would do the trick. However, do not use hidden just because you want this effect. Ask yourself if hidden is semantically correct first (see above). If hidden is not semantically correct, but you still want to visually hide the element, you can use other techniques such as CSS.

Elements with aria-hidden="true" are not exposed to the accessibility tree, so for example, screen readers won’t announce them. This technique should be used carefully, as it will provide different experiences to different users: accessible user agents won’t announce/render them, but they are still rendered on visual agents. This can be a good thing when done correctly, but it has the potential to be abused.

Syntactic Difference

Lastly, there is a difference in syntax between the two attributes.

hidden is a boolean attribute, meaning if the attribute is present it is true—regardless of whatever value it might have—and if the attribute is absent it is false. For the true case, the best practice is to either use no value at all (<div hidden>...</div>), or the empty string value (<div hidden="">...</div>). I would not recommend hidden="true" because someone reading/updating your code might infer that hidden="false" would have the opposite effect, which is simply incorrect.

aria-hidden, by contrast, is an enumerated attribute, allowing one of a finite list of values. If the aria-hidden attribute is present, its value must be either "true" or "false". If you want the "undefined (default)" state, remove the attribute altogether.


Further reading: https://github.com/chharvey/chharvey.github.io/wiki/Hidden-Content

IntelliJ: Working on multiple projects

For who uses Gradle can also avail the same:

enter image description here

enter image description here

Go to: 1. View --> Tool Windows --> Gradle 2. Click on the + button and add your build.gradle file

Difference between multitasking, multithreading and multiprocessing?

MultiProgramming - In a multiprogramming system, there are more than one programs loaded in main memory which are ready to execute. Only one program at a time is able to get the CPU for executing its instructions while all others are waiting their turn. The main idea of multiprogramming is to maximize the use of CPU time. Suppose currently running process is performing an I/O task, then OS may interrupt that process and give the control to one of the other in - main memory programs that are ready to execute (i.e. process context switching). In this way, no CPU time is wasted by system waiting for the I/O task to be completed.

MultiProcessing - Multiprocessing is the ability of an operating system to execute more than one process simultaneously on a multi processor machine. In multiprocessing system, a computer uses more than one CPU at a tme.

Multitasking - Multitasking is the ability of an operating system to execute more than one task simultaneously on single processor machine, these multiple tasks share common resources such as CPU and memory. In multitasking system, CPU switches from one task to next task so quickly that appears as all tasks are executing at the same time.

There are differences between multitasking and multiprogramming. A task in a multitasking system is not whole application program but it can refres to a "thread of execution" when one process is divided into sub-tasks. Each smaller task does not hijack the CPU until it finishes, they share a small amount of the CPU time called Quantum. Multiprogramming and multitasking operating systems are time sharing systems.

Multithreading - Multithreading is the extension of multitasking. Multithreading is the ability of an operating system to subdivide the specific operation within a single application into individual threads. Each of these threads can run in parallel. The OS divides processing time not only among different applications but also among each thread within an application.

Common xlabel/ylabel for matplotlib subplots

It will look better if you reserve space for the common labels by making invisible labels for the subplot in the bottom left corner. It is also good to pass in the fontsize from rcParams. This way, the common labels will change size with your rc setup, and the axes will also be adjusted to leave space for the common labels.

fig_size = [8, 6]
fig, ax = plt.subplots(5, 2, sharex=True, sharey=True, figsize=fig_size)
# Reserve space for axis labels
ax[-1, 0].set_xlabel('.', color=(0, 0, 0, 0))
ax[-1, 0].set_ylabel('.', color=(0, 0, 0, 0))
# Make common axis labels
fig.text(0.5, 0.04, 'common X', va='center', ha='center', fontsize=rcParams['axes.labelsize'])
fig.text(0.04, 0.5, 'common Y', va='center', ha='center', rotation='vertical', fontsize=rcParams['axes.labelsize'])

enter image description here enter image description here

C# get and set properties for a List Collection

Or

public class Section
{
  public String Head { get; set; }
  private readonly List<string> _subHead = new List<string>();
  private readonly List<string> _content = new List<string>();

  public IEnumerable<string> SubHead { get { return _subHead; } }
  public IEnumerable<string> Content { get { return _content; } }

  public void AddContent(String argValue)
  {
    _content.Add(argValue);
  }

  public void AddSubHeader(String argValue)
  {
    _subHead.Add(argValue);
  }
}

All depends on how much of the implementaton of content and subhead you want to hide.

Where to find free public Web Services?

https://www.programmableweb.com/ -- Great collection of all category API's across web. It not only show cases the API's , but also Developers who use those API's in their applications and code samples, rating of the API and much more. They have more than apis they also have sdk and libraries too.

How to Check if value exists in a MySQL database

I tried to d this for a while and $sqlcommand = 'SELECT * FROM database WHERE search="'.$searchString.'";';
$sth = $db->prepare($sqlcommand); $sth->execute(); $record = $sth->fetch(); if ($sth->fetchColumn() > 0){}
just works if there are TWO identical entries, but, if you replace if ($sth->fetchColumn() > 0){} with if ($result){} it works with only one matching record, hope this helps.

Shorter syntax for casting from a List<X> to a List<Y>?

You can use List<Y>.ConvertAll<T>([Converter from Y to T]);

How to get all keys with their values in redis

I had the same problem, and I felt on your post.

I think the easiest way to solve this issue is by using redis Hashtable.

It allows you to save a Hash, with different fields and values associated with every field.

To get all the fiels and values client.HGETALLL does the trick. It returns an array of

all the fields followed by their values.

More informations here https://redis.io/commands/hgetall

How to rollback everything to previous commit

I searched for multiple options to get my git reset to specific commit, but most of them aren't so satisfactory.

I generally use this to reset the git to the specific commit in source tree.

  1. select commit to reset on sourcetree.

  2. In dropdowns select the active branch , first Parent Only

  3. And right click on "Reset branch to this commit" and select hard reset option (soft, mixed and hard)

  4. and then go to terminal git push -f

You should be all set!

Close Bootstrap Modal

$('#modal').modal('toggle'); 

or

$('#modal').modal().hide();

should work.

But if nothing else works you can call the modal close button directly:

$("#modal .close").click()

Hash string in c#

I think what you're looking for is not hashing but encryption. With hashing, you will not be able to retrieve the original filename from the "hash" variable. With encryption you can, and it is secure.

See AES in ASP.NET with VB.NET for more information about encryption in .NET.

An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode

I ran into this problem and inspired by @Jeremy Cook's answer, I bit the bullet to find out what the heck caused IIS 7 Integrated mode to not like my web.config. Here's my scenario:

  1. Web API (version 4.0.030506.0 aka the old one)
  2. .NET 4.0
  3. Attribute Routing 3.5.6 for Web API [spoiler alert: it was this guy!]

I wanted to use attribute routing in a project that (unfortunately) had to use .NET 4 and hence could not use Web API 2.2 (which needs .NET 4.5). The well meaning NuGet package added this section under the <system.web> section:

<system.web>
<httpHandlers>
      <add verb="*" path="routes.axd" type="AttributeRouting.Web.Logging.LogRoutesHandler, AttributeRouting.Web" />
    </httpHandlers>
</system.web>

[I say well meaning, because this part is required on older versions of IIS]

Removing this section got me past the HTTP 500.23!!

Summary: I second Jeremy's words that it is important to understand why things don't work rather than just "masking the symptom". Even if you have to mask the symptom, you know what you are doing (and why) :-)

How do I add a foreign key to an existing SQLite table?

Please check https://www.sqlite.org/lang_altertable.html#otheralter

The only schema altering commands directly supported by SQLite are the "rename table" and "add column" commands shown above. However, applications can make other arbitrary changes to the format of a table using a simple sequence of operations. The steps to make arbitrary changes to the schema design of some table X are as follows:

  1. If foreign key constraints are enabled, disable them using PRAGMA foreign_keys=OFF.
  2. Start a transaction.
  3. Remember the format of all indexes and triggers associated with table X. This information will be needed in step 8 below. One way to do this is to run a query like the following: SELECT type, sql FROM sqlite_master WHERE tbl_name='X'.
  4. Use CREATE TABLE to construct a new table "new_X" that is in the desired revised format of table X. Make sure that the name "new_X" does not collide with any existing table name, of course.
  5. Transfer content from X into new_X using a statement like: INSERT INTO new_X SELECT ... FROM X.
  6. Drop the old table X: DROP TABLE X.
  7. Change the name of new_X to X using: ALTER TABLE new_X RENAME TO X.
  8. Use CREATE INDEX and CREATE TRIGGER to reconstruct indexes and triggers associated with table X. Perhaps use the old format of the triggers and indexes saved from step 3 above as a guide, making changes as appropriate for the alteration.
  9. If any views refer to table X in a way that is affected by the schema change, then drop those views using DROP VIEW and recreate them with whatever changes are necessary to accommodate the schema change using CREATE VIEW.
  10. If foreign key constraints were originally enabled then run PRAGMA foreign_key_check to verify that the schema change did not break any foreign key constraints.
  11. Commit the transaction started in step 2.
  12. If foreign keys constraints were originally enabled, reenable them now.

The procedure above is completely general and will work even if the schema change causes the information stored in the table to change. So the full procedure above is appropriate for dropping a column, changing the order of columns, adding or removing a UNIQUE constraint or PRIMARY KEY, adding CHECK or FOREIGN KEY or NOT NULL constraints, or changing the datatype for a column, for example.

Uri not Absolute exception getting while calling Restful Webservice

An absolute URI specifies a scheme; a URI that is not absolute is said to be relative.

http://docs.oracle.com/javase/8/docs/api/java/net/URI.html

So, perhaps your URLEncoder isn't working as you're expecting (the https bit)?

    URLEncoder.encode(uri) 

How to permanently set $PATH on Linux/Unix?

You can also set permanently, editing one of these files:

/etc/profile (for all users)

~/.bash_profile (for current user)

~/.bash_login (for current user)

~/.profile (for current user)

You can also use /etc/environment to set a permanent PATH environment variable, but it does not support variable expansion.

Extracted from: http://www.sysadmit.com/2016/06/linux-anadir-ruta-al-path.html

Ordering by the order of values in a SQL IN() clause

Ans to get sorted data.

SELECT ...
FROM ...
ORDER  BY FIELD(user_id,5,3,2,...,50)  LIMIT 10

"Uncaught TypeError: a.indexOf is not a function" error when opening new foundation project

I'm using jQuery 3.3.1 and I received the same error, in my case, the URL was an Object vs a string.

What happened was, that I took URL = window.location - which returned an object. Once I've changed it into window.location.href - it worked w/o the e.indexOf error.

Convert IEnumerable to DataTable

So, 10 years later this is still a thing :)

I've tried every answer on this page (ATOW)
and also some ILGenerator powered solutions (FastMember and Fast.Reflection).
But a compiled Lambda Expression seems to be the fastest.
At least for my use cases (on .Net Core 2.2).

This is what I am using for now:

public static class EnumerableExtensions {

    internal static Func<TClass, object> CompileGetter<TClass>(string propertyName) {
        var param = Expression.Parameter(typeof(TClass));
        var body = Expression.Convert(Expression.Property(param, propertyName), typeof(object));
        return Expression.Lambda<Func<TClass, object>>(body,param).Compile();
    }     

    public static DataTable ToDataTable<T>(this IEnumerable<T> collection) {
        var dataTable = new DataTable();
        var properties = typeof(T)
                        .GetProperties(BindingFlags.Public | BindingFlags.Instance)
                        .Where(p => p.CanRead)
                        .ToArray();

        if (properties.Length < 1) return null;
        var getters = new Func<T, object>[properties.Length];

        for (var i = 0; i < properties.Length; i++) {
            var columnType = Nullable.GetUnderlyingType(properties[i].PropertyType) ?? properties[i].PropertyType;
            dataTable.Columns.Add(properties[i].Name, columnType);
            getters[i] = CompileGetter<T>(properties[i].Name);
        }

        foreach (var row in collection) {
            var dtRow = new object[properties.Length];
            for (var i = 0; i < properties.Length; i++) {
                dtRow[i] = getters[i].Invoke(row) ?? DBNull.Value;
            }
            dataTable.Rows.Add(dtRow);
        }

        return dataTable;
    }
}

Only works with properties (not fields) but it works on Anonymous Types.

How to add the JDBC mysql driver to an Eclipse project?

  1. copy mysql-connector-java-5.1.24-bin.jar

  2. Paste it into \Apache Software Foundation\Tomcat 6.0\lib\<--here-->

  3. Restart Your Server from Eclipes.

  4. Done

PostgreSQL database service

(start -> run -> services.msc) and look for the postgresql-[version] service then right click and enable it

How to implement oauth2 server in ASP.NET MVC 5 and WEB API 2

I also struggled finding articles on how to just generate the token part. I never found one and wrote my own. So if it helps:

The things to do are:

  • Create a new web application
  • Install the following NuGet packages:
    • Microsoft.Owin
    • Microsoft.Owin.Host.SystemWeb
    • Microsoft.Owin.Security.OAuth
    • Microsoft.AspNet.Identity.Owin
  • Add a OWIN startup class

Then create a HTML and a JavaScript (index.js) file with these contents:

var loginData = 'grant_type=password&[email protected]&password=test123';

var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function () {
    if (xmlhttp.readyState === 4 && xmlhttp.status === 200) {
        alert(xmlhttp.responseText);
    }
}
xmlhttp.open("POST", "/token", true);
xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlhttp.send(loginData);
<!DOCTYPE html>
<html>
<head>
    <title></title>
</head>
<body>
    <script type="text/javascript" src="index.js"></script>
</body>
</html>

The OWIN startup class should have this content:

using System;
using System.Security.Claims;
using Microsoft.Owin;
using Microsoft.Owin.Security.OAuth;
using OAuth20;
using Owin;

[assembly: OwinStartup(typeof(Startup))]

namespace OAuth20
{
    public class Startup
    {
        public static OAuthAuthorizationServerOptions OAuthOptions { get; private set; }

        public void Configuration(IAppBuilder app)
        {
            OAuthOptions = new OAuthAuthorizationServerOptions()
            {
                TokenEndpointPath = new PathString("/token"),
                Provider = new OAuthAuthorizationServerProvider()
                {
                    OnValidateClientAuthentication = async (context) =>
                    {
                        context.Validated();
                    },
                    OnGrantResourceOwnerCredentials = async (context) =>
                    {
                        if (context.UserName == "[email protected]" && context.Password == "test123")
                        {
                            ClaimsIdentity oAuthIdentity = new ClaimsIdentity(context.Options.AuthenticationType);
                            context.Validated(oAuthIdentity);
                        }
                    }
                },
                AllowInsecureHttp = true,
                AccessTokenExpireTimeSpan = TimeSpan.FromDays(1)
            };

            app.UseOAuthBearerTokens(OAuthOptions);
        }
    }
}

Run your project. The token should be displayed in the pop-up.

Batch script to delete files

in batch code your path should not contain any Space so pls change your folder name from "TEST 100%" to "TEST_100%" and your new code will be del "D:\TEST\TEST_100%\Archive*.TXT"

hope this will resolve your problem

How to Get enum item name from its value

You can define an operator that performs the output.

std::ostream& operator<<(std::ostream& lhs, WeekEnum e) {
    switch(e) {
    case Monday: lhs << "Monday"; break;
    .. etc
    }
    return lhs;
}

How to bind WPF button to a command in ViewModelBase?

 <Grid >
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*"/>
    </Grid.ColumnDefinitions>
    <Button Command="{Binding ClickCommand}" Width="100" Height="100" Content="wefwfwef"/>
</Grid>

the code behind for the window:

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        DataContext = new ViewModelBase();
    }
}

The ViewModel:

public class ViewModelBase
{
    private ICommand _clickCommand;
    public ICommand ClickCommand
    {
        get
        {
            return _clickCommand ?? (_clickCommand = new CommandHandler(() => MyAction(), ()=> CanExecute));
        }
    }
     public bool CanExecute
     {
        get
        {
            // check if executing is allowed, i.e., validate, check if a process is running, etc. 
            return true/false;
        }
     }

    public void MyAction()
    {

    }
}

Command Handler:

 public class CommandHandler : ICommand
{
    private Action _action;
    private Func<bool> _canExecute;

    /// <summary>
    /// Creates instance of the command handler
    /// </summary>
    /// <param name="action">Action to be executed by the command</param>
    /// <param name="canExecute">A bolean property to containing current permissions to execute the command</param>
    public CommandHandler(Action action, Func<bool> canExecute)
    {
        _action = action;
        _canExecute = canExecute;
    }

    /// <summary>
    /// Wires CanExecuteChanged event 
    /// </summary>
    public event EventHandler CanExecuteChanged
    {
        add { CommandManager.RequerySuggested += value; }
        remove { CommandManager.RequerySuggested -= value; }
    }

    /// <summary>
    /// Forcess checking if execute is allowed
    /// </summary>
    /// <param name="parameter"></param>
    /// <returns></returns>
    public bool CanExecute(object parameter)
    {
        return _canExecute.Invoke();
    }

    public void Execute(object parameter)
    {
        _action();
    }
}

I hope this will give you the idea.

How do I check the difference, in seconds, between two dates?

import time  
current = time.time()

...job...
end = time.time()
diff = end - current

would that work for you?

How to implement a queue using two stacks?

here is my solution in java using linkedlist.

class queue<T>{
static class Node<T>{
    private T data;
    private Node<T> next;
    Node(T data){
        this.data = data;
        next = null;
    }
}
Node firstTop;
Node secondTop;

void push(T data){
    Node temp = new Node(data);
    temp.next = firstTop;
    firstTop = temp;
}

void pop(){
    if(firstTop == null){
        return;
    }
    Node temp = firstTop;
    while(temp != null){
        Node temp1 = new Node(temp.data);
        temp1.next = secondTop;
        secondTop = temp1;
        temp = temp.next;
    }
    secondTop = secondTop.next;
    firstTop = null;
    while(secondTop != null){
        Node temp3 = new Node(secondTop.data);
        temp3.next = firstTop;
        firstTop = temp3;
        secondTop = secondTop.next;
    }
}

}

Note : In this case, pop operation is very time consuming. So i won't suggest to create a queue using two stack.

How to get HttpRequestMessage data

  System.IO.StreamReader reader = new System.IO.StreamReader(HttpContext.Current.Request.InputStream);
  reader.BaseStream.Position = 0;
  string requestFromPost = reader.ReadToEnd();

Spring Boot - Loading Initial Data

If you want to insert only few rows and u have JPA Setup. You can use below

    @SpringBootApplication
        @Slf4j
        public class HospitalManagementApplication {

            public static void main(String[] args) {
                SpringApplication.run(HospitalManagementApplication.class, args);
            }            

            @Bean
            ApplicationRunner init(PatientRepository repository) {
                return (ApplicationArguments args) ->  dataSetup(repository);
            } 

            public void dataSetup(PatientRepository repository){
            //inserts

     }

$('body').on('click', '.anything', function(){})

If you want to capture click on everything then do

$("*").click(function(){
//code here
}

I use this for selector: http://api.jquery.com/all-selector/

This is used for handling clicks: http://api.jquery.com/click/

And then use http://api.jquery.com/event.preventDefault/

To stop normal clicking actions.

How can I find script's directory?

import os
script_dir = os.path.dirname(os.path.realpath(__file__)) + os.sep

How to find the serial port number on Mac OS X?

Found the port esp32 was connected to by -

ls /dev/*

You would get a long list and you can find the port you need

Refresh page after form submitting

LOL, I'm just wondering why no one had idea about the PHP header function:

header("Refresh: 0"); // here 0 is in seconds

I use this, so user is not prompt to resubmit data if he refresh the page.

See Refresh a page using PHP for more details

Measuring Query Performance : "Execution Plan Query Cost" vs "Time Taken"

Use SET STATISTICS TIME ON

above your query.

Below near result tab you can see a message tab. There you can see the time.

Transposing a 2D-array in JavaScript

array[0].map((_, colIndex) => array.map(row => row[colIndex]));

map calls a provided callback function once for each element in an array, in order, and constructs a new array from the results. callback is invoked only for indexes of the array which have assigned values; it is not invoked for indexes which have been deleted or which have never been assigned values.

callback is invoked with three arguments: the value of the element, the index of the element, and the Array object being traversed. [source]

Insert an item into sorted list in Python

This is the best way to append the list and insert values to sorted list:

 a = [] num = int(input('How many numbers: ')) for n in range(num):
     numbers = int(input('Enter values:'))
     a.append(numbers)

 b = sorted(a) print(b) c = int(input("enter value:")) for i in
 range(len(b)):
     if b[i] > c:
         index = i
         break d = b[:i] + [c] + b[i:] print(d)`

Best way to remove an event handler in jQuery?

This wasn't available when this question was answered, but you can also use the live() method to enable/disable events.

$('#myimage:not(.disabled)').live('click', myclickevent);

$('#mydisablebutton').click( function () { $('#myimage').addClass('disabled'); });

What will happen with this code is that when you click #mydisablebutton, it will add the class disabled to the #myimage element. This will make it so that the selector no longer matches the element and the event will not be fired until the 'disabled' class is removed making the .live() selector valid again.

This has other benefits by adding styling based on that class as well.

Why can't a text column have a default value in MySQL?

For Ubuntu 16.04:

How to disable strict mode in MySQL 5.7:

Edit file /etc/mysql/mysql.conf.d/mysqld.cnf

If below line exists in mysql.cnf

sql-mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"

Then Replace it with

sql_mode='MYSQL40'

Otherwise

Just add below line in mysqld.cnf

sql_mode='MYSQL40'

This resolved problem.

libz.so.1: cannot open shared object file

Check below link: Specially "Install 32 bit libraries (if you're on 64 bit)"

 https://github.com/meteor/meteor/wiki/Mobile-Dev-Install:-Android-on-Linux

Add an object to a python list

while you should show how your code looks like that gives the problem, i think this scenario is very common. See copy/deepcopy

How to use hex color values

RGBA Version Swift 3/4

I like @Luca's answer as i think it's the most elegant.

However I don't want my colours specified in ARGB. I'd rather RGBA + also i needed to hack in the case of dealing with strings that specify 1 character for each of the channels "#FFFA".

This version also adds error throwing + strips the '#' character if it's included in the string. Here is my modified form for Swift.

public enum ColourParsingError: Error
{
    
    case invalidInput(String)
}
extension UIColor {
    public convenience init(hexString: String) throws
    {
        let hexString = hexString.replacingOccurrences(of: "#", with: "")
        let hex = hexString.trimmingCharacters(in:NSCharacterSet.alphanumerics.inverted)
        var int = UInt32()
        Scanner(string: hex).scanHexInt32(&int)
        let a, r, g, b: UInt32
        switch hex.count 
        {
        case 3: // RGB (12-bit)
            (r, g, b,a) = ((int >> 8) * 17, (int >> 4 & 0xF) * 17, (int & 0xF) * 17,255)
        //iCSS specification in the form of #F0FA
        case 4: // RGB (24-bit)
            (r, g, b,a) = ((int >> 12) * 17, (int >> 8 & 0xF) * 17, (int >> 4 & 0xF) * 17, (int & 0xF) * 17)
        case 6: // RGB (24-bit)
            (r, g, b, a) = (int >> 16, int >> 8 & 0xFF, int & 0xFF,255)
        case 8: // ARGB (32-bit)
            (r, g, b, a) = (int >> 24, int >> 16 & 0xFF, int >> 8 & 0xFF, int & 0xFF)
        default:
            throw ColourParsingError.invalidInput("String is not a valid hex colour string: \(hexString)")
        }
        self.init(red: CGFloat(r) / 255, green: CGFloat(g) / 255, blue: CGFloat(b) / 255, alpha: CGFloat(a) / 255)
    }
}

How can I find out a file's MIME type (Content-Type)?

one of the other tool (besides file) you can use is xdg-mime

eg xdg-mime query filetype <file>

if you have yum,

yum install xdg-utils.noarch

An example comparison of xdg-mime and file on a Subrip(subtitles) file

$ xdg-mime query filetype subtitles.srt
application/x-subrip

$ file --mime-type subtitles.srt
subtitles.srt: text/plain

in the above file only show it as plain text.

Rails: Address already in use - bind(2) (Errno::EADDRINUSE)

You can find and kill the running processes: ps aux | grep puma Then you can kill it with kill PID

How to format strings in Java

This solution worked for me. I needed to create urls for a REST client dynamically so I created this method, so you just have to pass the restURL like this

/customer/{0}/user/{1}/order

and add as many params as you need:

public String createURL (String restURL, Object ... params) {       
    return new MessageFormat(restURL).format(params);
}

You just have to call this method like this:

createURL("/customer/{0}/user/{1}/order", 123, 321);

The output

"/customer/123/user/321/order"

MySQL INNER JOIN select only one row from second table

@John Woo's answer helped me solve a similar problem. I've improved upon his answer by setting the correct ordering as well. This has worked for me:

SELECT  a.*, c.*
FROM users a 
    INNER JOIN payments c
        ON a.id = c.user_ID
    INNER JOIN (
        SELECT user_ID, MAX(date) as maxDate FROM
        (
            SELECT user_ID, date
            FROM payments
            ORDER BY date DESC
        ) d
        GROUP BY user_ID
    ) b ON c.user_ID = b.user_ID AND
           c.date = b.maxDate
WHERE a.package = 1

I'm not sure how efficient this is, though.

How to create a string with format?

I think this could help you:

let timeNow = time(nil)
let aStr = String(format: "%@%x", "timeNow in hex: ", timeNow)
print(aStr)

Example result:

timeNow in hex: 5cdc9c8d

Pointer vs. Reference

A reference is an implicit pointer. Basically you can change the value the reference points to but you can't change the reference to point to something else. So my 2 cents is that if you only want to change the value of a parameter pass it as a reference but if you need to change the parameter to point to a different object pass it using a pointer.

How can I convert a long to int in Java?

I Also Faced This Problem. To Solve This I have first converted my long to String then to int.

int i = Integer.parseInt(String.valueOf(long));

How to create a user in Django?

If you creat user normally, you will not be able to login as password creation method may b different You can use default signup form for that

from django.contrib.auth.forms import UserCreationForm

You can extend that also

from django.contrib.auth.forms import UserCreationForm

class UserForm(UserCreationForm):
    mobile = forms.CharField(max_length=15, min_length=10)
    email = forms.EmailField(required=True)
    class Meta:
        model = User
        fields = ['username', 'password', 'first_name', 'last_name', 'email', 'mobile' ]

Then in view use this class

class UserCreate(CreateView):
    form_class = UserForm
    template_name = 'registration/signup.html'
    success_url = reverse_lazy('list')

    def form_valid(self, form):
        user = form.save()

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

Here's one more version to try for those having issues with the others. It pulls together the techniques discussed in this duplicate question, and generates the required helper DIVs dynamically so no extra HTML is required.

CSS:

.sticky { position:fixed; top:0; }

JQuery:

function make_sticky(id) {
    var e = $(id);
    var w = $(window);
    $('<div/>').insertBefore(id);
    $('<div/>').hide().css('height',e.outerHeight()).insertAfter(id);
    var n = e.next();
    var p = e.prev();
    function sticky_relocate() {
      var window_top = w.scrollTop();
      var div_top = p.offset().top;
      if (window_top > div_top) {
        e.addClass('sticky');
        n.show();
      } else {
        e.removeClass('sticky');
        n.hide();
      }
    }
    w.scroll(sticky_relocate);
    sticky_relocate();
}

To make an element sticky, do:

make_sticky('#sticky-elem-id');

When the element becomes sticky, the code manages the position of the remaining content to keep it from jumping into the gap left by the sticky element. It also returns the sticky element to its original non-sticky position when scrolling back above it.

Python style - line continuation with strings?

Another possibility is to use the textwrap module. This also avoids the problem of "string just sitting in the middle of nowhere" as mentioned in the question.

import textwrap
mystr = """\
        Why, hello there
        wonderful stackoverfow people"""
print (textwrap.fill(textwrap.dedent(mystr)))

Can I use git diff on untracked files?

Assuming you do not have local commits,

git diff origin/master

Difference in System. exit(0) , System.exit(-1), System.exit(1 ) in Java

Here is the answer.

System.exit(0);// normal termination - Successful - zero
System.exit(-1);//Exit with some Error
System.exit(1);//one or any positive integer // exit with some Information message

Set language for syntax highlighting in Visual Studio Code

Note that for "Untitled" editor ("Untitled-1", "Untitled-2"), you now can set the language in the settings.

The previous setting was:

"files.associations": {
        "untitled-*": "javascript"
 }

This will not always work anymore, because with VSCode 1.42 (Q1 2020) will change the title of those untitled editors.
The title will now be the first line of the document for the editor title, along the generic name as part of the description.
It won't start anymore with "untitled-"

See "Untitled editor improvements"

Regarding the associated language for those "Untitled" editors:

By default, untitled files do not have a specific language mode configured.

VS Code has a setting, files.defaultLanguage, to configure a default language for untitled files.

With this release, the setting can take a new value {activeEditorLanguage} that will dynamically use the language mode of the currently active editor instead of a fixed default.

In addition, when you copy and paste text into an untitled editor, VS Code will now automatically change the language mode of the untitled editor if the text was copied from a VS Code editor:

https://media.githubusercontent.com/media/microsoft/vscode-docs/vnext/release-notes/images/1_42/untitled-copy2.gif

And see workbench.editor.untitled.labelFormat in VSCode 1.43.

How do I convert a Django QuerySet into list of dicts?

Use the .values() method:

>>> Blog.objects.values()
[{'id': 1, 'name': 'Beatles Blog', 'tagline': 'All the latest Beatles news.'}],
>>> Blog.objects.values('id', 'name')
[{'id': 1, 'name': 'Beatles Blog'}]

Note: the result is a QuerySet which mostly behaves like a list, but isn't actually an instance of list. Use list(Blog.objects.values(…)) if you really need an instance of list.

Why is Dictionary preferred over Hashtable in C#?

Collections & Generics are useful for handling group of objects. In .NET, all the collections objects comes under the interface IEnumerable, which in turn has ArrayList(Index-Value)) & HashTable(Key-Value). After .NET framework 2.0, ArrayList & HashTable were replaced with List & Dictionary. Now, the Arraylist & HashTable are no more used in nowadays projects.

Coming to the difference between HashTable & Dictionary, Dictionary is generic where as Hastable is not Generic. We can add any type of object to HashTable, but while retrieving we need to cast it to the required type. So, it is not type safe. But to dictionary, while declaring itself we can specify the type of key and value, so there is no need to cast while retrieving.

Let's look at an example:

HashTable

class HashTableProgram
{
    static void Main(string[] args)
    {
        Hashtable ht = new Hashtable();
        ht.Add(1, "One");
        ht.Add(2, "Two");
        ht.Add(3, "Three");
        foreach (DictionaryEntry de in ht)
        {
            int Key = (int)de.Key; //Casting
            string value = de.Value.ToString(); //Casting
            Console.WriteLine(Key + " " + value);
        }

    }
}

Dictionary,

class DictionaryProgram
{
    static void Main(string[] args)
    {
        Dictionary<int, string> dt = new Dictionary<int, string>();
        dt.Add(1, "One");
        dt.Add(2, "Two");
        dt.Add(3, "Three");
        foreach (KeyValuePair<int, String> kv in dt)
        {
            Console.WriteLine(kv.Key + " " + kv.Value);
        }
    }
}

What's the easiest way to escape HTML in Python?

If you wish to escape HTML in a URL:

This is probably NOT what the OP wanted (the question doesn't clearly indicate in which context the escaping is meant to be used), but Python's native library urllib has a method to escape HTML entities that need to be included in a URL safely.

The following is an example:

#!/usr/bin/python
from urllib import quote

x = '+<>^&'
print quote(x) # prints '%2B%3C%3E%5E%26'

Find docs here

How do you check in python whether a string contains only numbers?

There are 2 methods that I can think of to check whether a string has all digits of not

Method 1(Using the built-in isdigit() function in python):-

>>>st = '12345'
>>>st.isdigit()
True
>>>st = '1abcd'
>>>st.isdigit()
False

Method 2(Performing Exception Handling on top of the string):-

st="1abcd"
try:
    number=int(st)
    print("String has all digits in it")
except:
    print("String does not have all digits in it")

The output of the above code will be:

String does not have all digits in it

Default interface methods are only supported starting with Android N

This also happened to me but using Dynamic Features. I already had Java 8 compatibility enabled in the app module but I had to add this compatibility lines to the Dynamic Feature module and then it worked.

Error C1083: Cannot open include file: 'stdafx.h'

You can fix this problem by adding "$(ProjectDir)" (or wherever the stdafx.h is) to list of directories under Project->Properties->Configuration Properties->C/C++->General->Additional Include Directories.

Send email using the GMail SMTP server from a PHP page

To install PEAR's Mail.php in Ubuntu, run following set of commands:

    sudo apt-get install php-pear
    sudo pear install mail
    sudo pear install Net_SMTP
    sudo pear install Auth_SASL
    sudo pear install mail_mime

Querying DynamoDB by date

You can have multiple identical hash keys; but only if you have a range key that varies. Think of it like file formats; you can have 2 files with the same name in the same folder as long as their format is different. If their format is the same, their name must be different. The same concept applies to DynamoDB's hash/range keys; just think of the hash as the name and the range as the format.

Also, I don't recall if they had these at the time of the OP (I don't believe they did), but they now offer Local Secondary Indexes.

My understanding of these is that it should now allow you to perform the desired queries without having to do a full scan. The downside is that these indexes have to be specified at table creation, and also (I believe) cannot be blank when creating an item. In addition, they require additional throughput (though typically not as much as a scan) and storage, so it's not a perfect solution, but a viable alternative, for some.

I do still recommend Mike Brant's answer as the preferred method of using DynamoDB, though; and use that method myself. In my case, I just have a central table with only a hash key as my ID, then secondary tables that have a hash and range that can be queried, then the item points the code to the central table's "item of interest", directly.

Additional data regarding the secondary indexes can be found in Amazon's DynamoDB documentation here for those interested.

Anyway, hopefully this will help anyone else that happens upon this thread.

Pandas: create two new columns in a dataframe with values calculated from a pre-existing column

I'd just use zip:

In [1]: from pandas import *

In [2]: def calculate(x):
   ...:     return x*2, x*3
   ...: 

In [3]: df = DataFrame({'a': [1,2,3], 'b': [2,3,4]})

In [4]: df
Out[4]: 
   a  b
0  1  2
1  2  3
2  3  4

In [5]: df["A1"], df["A2"] = zip(*df["a"].map(calculate))

In [6]: df
Out[6]: 
   a  b  A1  A2
0  1  2   2   3
1  2  3   4   6
2  3  4   6   9

Html.DropDownList - Disabled/Readonly

Put this in style

 select[readonly] option, select[readonly] optgroup {
        display: none;
    }

What does servletcontext.getRealPath("/") mean and when should I use it

My Method:

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {

    try {
        String path = request.getRealPath("/WEB-INF/conf.properties");
        Properties p = new Properties();
        p.load(new FileInputStream(path));

        String StringConexion=p.getProperty("StringConexion");
        String User=p.getProperty("User");
        String Password=p.getProperty("Password");
    }
    catch(Exception e){
        String msg = "Excepcion " + e;
    }
}

Can not run Java Applets in Internet Explorer 11 using JRE 7u51

Finally resolved my java install issue on Win 7 64-bit running IE11.

Even though I installed the latest Java (65) via a java auto-update prompt, tried a verify java version and java failed to run, shut down all IE instances, failed to run verify again, shut down all running programs, failed to run verify again, rebooted, failed to run verify again, re-installed 65 again (shutting down the browser manually as it downloaded), and finally verify ran. What a pain.

The message I kept receiving was "The page you are viewing uses Java ..."; e.g. https://www.java.com/en/download/help/ie_tips.xml. I do use sleep mode on my desktop and I believe that this is probably the major issue with install and IE with its "clever" integration into the OS and explorer/desktop. I thought the government told them to not do that. I've had issues with CD-ROM drive disappearing and other unexplained periodic issues; all cured after a full reboot. They are infrequent, so I live with them for the convenience of faster startup times.

Hope this helps someone!

Convert javascript array to string

Use join() and the separator.

Working example

_x000D_
_x000D_
var arr = ['a', 'b', 'c', 1, 2, '3'];_x000D_
_x000D_
// using toString method_x000D_
var rslt = arr.toString(); _x000D_
console.log(rslt);_x000D_
_x000D_
// using join method. With a separator '-'_x000D_
rslt = arr.join('-');_x000D_
console.log(rslt);_x000D_
_x000D_
// using join method. without a separator _x000D_
rslt = arr.join('');_x000D_
console.log(rslt);
_x000D_
_x000D_
_x000D_

CSS media query to target iPad and iPad only?

These days you can use a Media Queries Level 4 feature to check if the device has the ability to 'hover' over elements.

@media (hover: hover) { ... }

Since the ipad has no 'hover' state you can effectively target touch devices like the ipad.

Split string with multiple delimiters in Python

Do a str.replace('; ', ', ') and then a str.split(', ')

Fixed point vs Floating point number

The term ‘fixed point’ refers to the corresponding manner in which numbers are represented, with a fixed number of digits after, and sometimes before, the decimal point. With floating-point representation, the placement of the decimal point can ‘float’ relative to the significant digits of the number. For example, a fixed-point representation with a uniform decimal point placement convention can represent the numbers 123.45, 1234.56, 12345.67, etc, whereas a floating-point representation could in addition represent 1.234567, 123456.7, 0.00001234567, 1234567000000000, etc.

Php - testing if a radio button is selected and get the value

Just simply use isset($_POST['radio']) so that whenever i click any of the radio button, the one that is clicked is set to the post.

 <form method="post" action="sample.php">
 select sex: 
 <input type="radio" name="radio" value="male">
 <input type="radio" name="radio" value="female">

 <input type="submit" value="submit">
 </form>

<?php

if (isset($_POST['radio'])){

    $Sex = $_POST['radio'];
 }
  ?>

C#: Printing all properties of an object

The ObjectDumper class has been known to do that. I've never confirmed, but I've always suspected that the immediate window uses that.

EDIT: I just realized, that the code for ObjectDumper is actually on your machine. Go to:

C:/Program Files/Microsoft Visual Studio 9.0/Samples/1033/CSharpSamples.zip

This will unzip to a folder called LinqSamples. In there, there's a project called ObjectDumper. Use that.

How can I delay a method call for 1 second?

NOTE: this will pause your whole thread, not just the one method.
Make a call to sleep/wait/halt for 1000 ms just before calling your method?

Sleep(1000); // does nothing the next 1000 mSek

Methodcall(params); // now do the real thing

Edit: The above answer applies to the general question "How can I delay a method call for 1 second?", which was the question asked at the time of the answer (infact the answer was given within 7 minutes of the original question :-)). No Info was given about the language at that time, so kindly stop bitching about the proper way of using sleep i XCode og the lack of classes...

With jQuery, how do I capitalize the first letter of a text field while the user is still editing that field?

Slight update to cumul's solution.

The function upperFirstAll doesn't work properly if there is more than one space between words. Replace the regular expression for this one to solve it:

$(this).val(txt.toLowerCase().replace(/^(.)|(\s|\-)+(.)/g,

How to know the size of the string in bytes?

From MSDN:

A String object is a sequential collection of System.Char objects that represent a string.

So you can use this:

var howManyBytes = yourString.Length * sizeof(Char);

Return empty cell from formula in Excel

Maybe this is cheating, but it works!

I also needed a table that is the source for a graph, and I didn't want any blank or zero cells to produce a point on the graph. It is true that you need to set the graph property, select data, hidden and empty cells to "show empty cells as Gaps" (click the radio button). That's the first step.

Then in the cells that may end up with a result that you don't want plotted, put the formula in an IF statement with an NA() results such as =IF($A8>TODAY(),NA(), *formula to be plotted*)

This does give the required graph with no points when an invalid cell value occurs. Of course this leaves all cells with that invalid value to read #N/A, and that's messy.

To clean this up, select the cell that may contain the invalid value, then select conditional formatting - new rule. Select 'format only cells that contain' and under the rule description select 'errors' from the drop down box. Then under format select font - colour - white (or whatever your background colour happens to be). Click the various buttons to get out and you should see that cells with invalid data look blank (they actually contain #N/A but white text on a white background looks blank.) Then the linked graph also does not display the invalid value points.

How to concatenate strings with padding in sqlite

Just one more line for @tofutim answer ... if you want custom field name for concatenated row ...

SELECT 
  (
    col1 || '-' || SUBSTR('00' || col2, -2, 2) | '-' || SUBSTR('0000' || col3, -4, 4)
  ) AS my_column 
FROM
  mytable;

Tested on SQLite 3.8.8.3, Thanks!

Jenkins Slave port number for firewall

We had a similar situation, but in our case Infosec agreed to allow any to 1, so we didnt had to fix the slave port, rather fixing the master to high level JNLP port 49187 worked ("Configure Global Security" -> "TCP port for JNLP slave agents").

TCP
49187 - Fixed jnlp port
8080 - jenkins http port

Other ports needed to launch slave as a windows service

TCP
135 
139 
445

UDP
137
138

Round integers to the nearest 10

round() can take ints and negative numbers for places, which round to the left of the decimal. The return value is still a float, but a simple cast fixes that:

>>> int(round(5678,-1))
5680
>>> int(round(5678,-2))
5700
>>> int(round(5678,-3))
6000

How can I get city name from a latitude and longitude point?

BigDataCloud also has a nice API for this, also for nodejs users.

they have API for client - free. But also for backend, using API_KEY (free according to quota).

Their GitHub page.

the code looks like:

const client = require('@bigdatacloudapi/client')(API_KEY);

async foo() {
    ...
    const location: string = await client.getReverseGeocode({
          latitude:'32.101786566878445', 
          longitude: '34.858965073072056'
    });
}

Is there a C# String.Format() equivalent in JavaScript?

Try sprintf() for javascript.

Or

// First, checks if it isn't implemented yet.
if (!String.prototype.format) {
  String.prototype.format = function() {
    var args = arguments;
    return this.replace(/{(\d+)}/g, function(match, number) { 
      return typeof args[number] != 'undefined'
        ? args[number]
        : match
      ;
    });
  };
}

"{0} is dead, but {1} is alive! {0} {2}".format("ASP", "ASP.NET")

Both answers pulled from JavaScript equivalent to printf/string.format

How can I select checkboxes using the Selenium Java WebDriver?

It appears that the Internet Explorer driver does not interact with everything in the same way the other drivers do and checkboxes is one of those cases.

The trick with checkboxes is to send the Space key instead of using a click (only needed on Internet Explorer), like so in C#:

if (driver.Capabilities.BrowserName.Equals(“internet explorer"))
    driver.findElement(By.id("idOfTheElement").SendKeys(Keys.Space);
else
    driver.findElement(By.id("idOfTheElement").Click();

"relocation R_X86_64_32S against " linking Error

I also had similar problems when trying to link static compiled fontconfig and expat into a linux shared object:

/opt/rh/devtoolset-7/root/usr/libexec/gcc/x86_64-redhat-linux/7/ld: /3rdparty/fontconfig/lib/linux-x86_64/libfontconfig.a(fccfg.o): relocation R_X86_64_32 against `.rodata.str1.1' can not be used when making a shared object; recompile with -fPIC
/opt/rh/devtoolset-7/root/usr/libexec/gcc/x86_64-redhat-linux/7/ld: /3rdparty/expat/lib/linux-x86_64/libexpat.a(xmlparse.o): relocation R_X86_64_PC32 against symbol `stderr@@GLIBC_2.2.5' can not be used when making a shared object; recompile with -fPIC
[...]

This contrary to the fact that I was already passing -fPIC flags though CFLAGS variable, and other compilers/linkers variants (clang/lld) were perfectly working with the same build configuration. It ended up that these dependencies control position-independent code settings through despicable autoconf scripts and need --with-pic switch during build configuration on linux gcc/ld combination, and its lack probably overrides same the setting in CFLAGS. Pass the switch to configure script and the dependencies will be correctly compiled with -fPIC.

Creating JSON on the fly with JObject

There are some environment where you cannot use dynamic (e.g. Xamarin.iOS) or cases in where you just look for an alternative to the previous valid answers.

In these cases you can do:

using Newtonsoft.Json.Linq;

JObject jsonObject =
     new JObject(
             new JProperty("Date", DateTime.Now),
             new JProperty("Album", "Me Against The World"),
             new JProperty("Year", "James 2Pac-King's blog."),
             new JProperty("Artist", "2Pac")
         )

More documentation here: http://www.newtonsoft.com/json/help/html/CreatingLINQtoJSON.htm

How to parse a CSV file in Bash?

If you want to read CSV file with some lines, so this the solution.

while IFS=, read -ra line
do 
    test $i -eq 1 && ((i=i+1)) && continue
    for col_val in ${line[@]}
    do
        echo -n "$col_val|"                 
    done
    echo        
done < "$csvFile"

How to get an Instagram Access Token

The Instagram API is meant for not only you, but for any Instagram user to potentially authenticate with your app. I followed the instructions on the Instagram Dev website. Using the first (Explicit) method, I was able to do this quite easily on the server.

Step 1) Add a link or button to your webpage which a user could click to initiate the authentication process:

<a href="https://api.instagram.com/oauth/authorize/?client_id=YOUR_CLIENT_ID&redirect_uri=YOUR_REDIRECT_URI&response_type=code">Get Started</a>

YOUR_CLIENT_ID and YOUR_REDIRECT_URI will be given to you after you successfully register your app in the Instagram backend, along with YOUR_CLIENT_SECRET used below.

Step 2) At the URI that you defined for your app, which is the same as YOUR_REDIRECT_URI, you need to accept the response from the Instagram server. The Instagram server will feed you back a code variable in the request. Then you need to use this code and other information about your app to make another request directly from your server to obtain the access_token. I did this in python using Django framework, as follows:

direct django to the response function in urls.py:

from django.conf.urls import url

from . import views

app_name = 'main'
urlpatterns = [
        url(r'^$', views.index, name='index'),
        url(r'^response/', views.response, name='response'),
]

Here is the response function, handling the request, views.py:

from django.shortcuts import render
import urllib
import urllib2
import json

def response(request):
    if 'code' in request.GET:
        url = 'https://api.instagram.com/oauth/access_token'
        values = {
            'client_id':'YOUR_CLIENT_ID',
            'client_secret':'YOUR_CLIENT_SECRET',
            'redirect_uri':'YOUR_REDIRECT_URI',
            'code':request.GET.get('code'),
            'grant_type':'authorization_code'
        }
        data = urllib.urlencode(values)
        req = urllib2.Request(url, data)
        response = urllib2.urlopen(req)
        response_string = response.read()
        insta_data = json.loads(response_string)
        if 'access_token' in insta_data and 'user' in insta_data:
            #authentication success
            return render(request, 'main/response.html')
        else:
            #authentication failure after step 2
            return render(request, 'main/auth_error.html')
    elif 'error' in req.GET:
        #authentication failure after step 1
        return render(request, 'main/auth_error.html')

This is just one way, but the process should be almost identical in PHP or any other server-side language.

How can I pause setInterval() functions?

The following code, provides a precision way to pause resume a timer.

How it works:

When the timer is resumed after a pause, it generates a correction cycle using a single timeout, that will consider the pause offset (exact time when the timer was paused between cycles). After the correction cycle finishes, it schedules the following cycles with a regular setInteval, and continues normally the cycle execution.

This allows to pause/resume the timer, without losing the sync.

Code :

_x000D_
_x000D_
function Timer(_fn_callback_ , _timer_freq_){_x000D_
    let RESUME_CORRECTION_RATE = 2;_x000D_
_x000D_
    let _timer_statusCode_;_x000D_
    let _timer_clockRef_;_x000D_
_x000D_
    let _time_ellapsed_;        // will store the total time ellapsed_x000D_
    let _time_pause_;           // stores the time when timer is paused_x000D_
    let _time_lastCycle_;       // stores the time of the last cycle_x000D_
_x000D_
    let _isCorrectionCycle_;_x000D_
 _x000D_
    /**_x000D_
     * execute in each clock cycle_x000D_
     */_x000D_
    const nextCycle = function(){_x000D_
        // calculate deltaTime_x000D_
        let _time_delta_        = new Date() - _time_lastCycle_;_x000D_
        _time_lastCycle_    = new Date();_x000D_
        _time_ellapsed_   += _time_delta_;_x000D_
_x000D_
        // if its a correction cicle (caused by a pause,_x000D_
        // destroy the temporary timeout and generate a definitive interval_x000D_
        if( _isCorrectionCycle_ ){_x000D_
            clearTimeout( _timer_clockRef_ );_x000D_
            clearInterval( _timer_clockRef_ );_x000D_
            _timer_clockRef_    = setInterval(  nextCycle , _timer_freq_  );_x000D_
            _isCorrectionCycle_ = false;_x000D_
        }_x000D_
        // execute callback_x000D_
        _fn_callback_.apply( timer, [ timer ] );_x000D_
    };_x000D_
_x000D_
    // initialize timer_x000D_
    _time_ellapsed_     = 0;_x000D_
    _time_lastCycle_     = new Date();_x000D_
    _timer_statusCode_   = 1;_x000D_
    _timer_clockRef_     = setInterval(  nextCycle , _timer_freq_  );_x000D_
_x000D_
_x000D_
    // timer public API_x000D_
    const timer = {_x000D_
        get statusCode(){ return _timer_statusCode_ },_x000D_
        get timestamp(){_x000D_
            let abstime;_x000D_
            if( _timer_statusCode_=== 1 ) abstime = _time_ellapsed_ + ( new Date() - _time_lastCycle_ );_x000D_
            else if( _timer_statusCode_=== 2 ) abstime = _time_ellapsed_ + ( _time_pause_ - _time_lastCycle_ );_x000D_
            return abstime || 0;_x000D_
        },_x000D_
_x000D_
        pause : function(){_x000D_
            if( _timer_statusCode_ !== 1 ) return this;_x000D_
            // stop timers_x000D_
            clearTimeout( _timer_clockRef_ );_x000D_
            clearInterval( _timer_clockRef_ );_x000D_
            // set new status and store current time, it will be used on_x000D_
            // resume to calculate how much time is left for next cycle_x000D_
            // to be triggered_x000D_
            _timer_statusCode_ = 2;_x000D_
            _time_pause_       = new Date();_x000D_
            return this;_x000D_
        },_x000D_
_x000D_
        resume: function(){_x000D_
            if( _timer_statusCode_ !== 2 ) return this;_x000D_
            _timer_statusCode_  = 1;_x000D_
            _isCorrectionCycle_ = true;_x000D_
            const delayEllapsedTime = _time_pause_ - _time_lastCycle_;_x000D_
            _time_lastCycle_    = new Date( new Date() - (_time_pause_ - _time_lastCycle_) );_x000D_
_x000D_
            _timer_clockRef_ = setTimeout(  nextCycle , _timer_freq_ - delayEllapsedTime - RESUME_CORRECTION_RATE);_x000D_
_x000D_
            return this;_x000D_
        } _x000D_
    };_x000D_
    return timer;_x000D_
};_x000D_
_x000D_
_x000D_
let myTimer = Timer( x=> console.log(x.timestamp), 1000);
_x000D_
<input type="button" onclick="myTimer.pause()" value="pause">_x000D_
<input type="button" onclick="myTimer.resume()" value="resume">
_x000D_
_x000D_
_x000D_

Code source :

This Timer is a modified and simplified version of advanced-timer, a js library created by myself, with many more functionalities.

The full library and documentation is available in NPM and GITHUB

Real-world examples of recursion

Anything program with tree or graph data structures will likely have some recursion.

Changing the action of a form with JavaScript/jQuery

You can actually just use

$("#form").attr("target", "NewAction");

As far as I know, this will NOT fail silently.

If the page is opening in a new target, you may need to make sure the URL is unique each time because Webkit (chrome/safari) will cache the fact you have visited that URL and won't perform the post.

For example

$("form").attr("action", "/Pages/GeneratePreview?" + new Date().getMilliseconds());

Import XXX cannot be resolved for Java SE standard classes

This is an issue relating JRE.In my case (eclipse Luna with Maven plugin, JDK 7) I solved this by making following change in pom.xml and then Maven Update Project.

from:

 <configuration>
        <source>1.8</source>
        <target>1.8</target>
</configuration>

to:

 <configuration>
        <source>1.7</source>
        <target>1.7</target>
</configuration>

Screenshot showing problem in JRE: enter image description here

How to reset index in a pandas dataframe?

data1.reset_index(inplace=True)

What is the Ruby <=> (spaceship) operator?

Since this operator reduces comparisons to an integer expression, it provides the most general purpose way to sort ascending or descending based on multiple columns/attributes.

For example, if I have an array of objects I can do things like this:

# `sort!` modifies array in place, avoids duplicating if it's large...

# Sort by zip code, ascending
my_objects.sort! { |a, b| a.zip <=> b.zip }

# Sort by zip code, descending
my_objects.sort! { |a, b| b.zip <=> a.zip }
# ...same as...
my_objects.sort! { |a, b| -1 * (a.zip <=> b.zip) }

# Sort by last name, then first
my_objects.sort! { |a, b| 2 * (a.last <=> b.last) + (a.first <=> b.first) }

# Sort by zip, then age descending, then last name, then first
# [Notice powers of 2 make it work for > 2 columns.]
my_objects.sort! do |a, b|
      8 * (a.zip   <=> b.zip) +
     -4 * (a.age   <=> b.age) +
      2 * (a.last  <=> b.last) +
          (a.first <=> b.first)
end

This basic pattern can be generalized to sort by any number of columns, in any permutation of ascending/descending on each.

Showing empty view when ListView is empty

Just to add that you don't really need to create new IDs, something like the following will work.

In the layout:

<ListView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@android:id/list"/>

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@android:id/empty"
    android:text="Empty"/>

Then in the activity:

    ListView listView = (ListView) findViewById(android.R.id.list);
    listView.setEmptyView(findViewById(android.R.id.empty));

Passing arguments to AsyncTask, and returning results

I sort of agree with leander on this one.

call:

new calc_stanica().execute(stringList.toArray(new String[stringList.size()]));

task:

public class calc_stanica extends AsyncTask<String, Void, ArrayList<String>> {
        @Override
        protected ArrayList<String> doInBackground(String... args) {
           ...
        }

        @Override
        protected void onPostExecute(ArrayList<String> result) {
           ... //do something with the result list here
        }
}

Or you could just make the result list a class parameter and replace the ArrayList with a boolean (success/failure);

public class calc_stanica extends AsyncTask<String, Void, Boolean> {
        private List<String> resultList;

        @Override
        protected boolean doInBackground(String... args) {
           ...
        }

        @Override
        protected void onPostExecute(boolean success) {
           ... //if successfull, do something with the result list here
        }
}

How does the vim "write with sudo" trick work?

:w - Write a file.

!sudo - Call shell sudo command.

tee - The output of write (vim :w) command redirected using tee. The % is nothing but current file name i.e. /etc/apache2/conf.d/mediawiki.conf. In other words tee command is run as root and it takes standard input and write it to a file represented by %. However, this will prompt to reload file again (hit L to load changes in vim itself):

tutorial link

Remove ListView items in Android

At first you should remove the item from your list. Later you may empty your adapter and refill it with new list.

private void add(final List<Track> trackList) {
    MyAdapter bindingData = new MyAdapter(MyActivity.this, trackList);

    list = (ListView) findViewById(R.id.my_list); // TODO

    list.setAdapter(bindingData);


    // Click event for single list row
    list.setOnItemClickListener(new OnItemClickListener() {

        public void onItemClick(AdapterView<?> parent, View view,
                final int position, long id) {
            // ShowPlacePref(places, position);
            AlertDialog.Builder showPlace = new AlertDialog.Builder(
                    Favoriler.this);
            showPlace.setMessage("Remove from list?");
            showPlace.setPositiveButton("DELETE", new OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {    

                    trackList.remove(position); //FIRST OF ALL REMOVE ITEM FROM LIST
                    list.setAdapter(null); // THEN EMPTY YOUR ADAPTER

                    add(trackList); // AT LAST REFILL YOUR LISTVIEW (Recursively)

                }

            });
            showPlace.setNegativeButton("CANCEL", new OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {

                }
            });
            showPlace.show();
        }

    });

}

What's the most elegant way to cap a number to a segment?

If you don’t want to define any function, writing it like Math.min(Math.max(x, a), b) isn’t that bad.

Do C# Timers elapse on a separate thread?

If the elapsed event takes longer then the interval, it will create another thread to raise the elapsed event. But there is a workaround for this

static void timer_Elapsed(object sender, ElapsedEventArgs e)    
{     
   try
   {
      timer.Stop(); 
      Thread.Sleep(2000);        
      Debug.WriteLine(Thread.CurrentThread.ManagedThreadId);    
   }
   finally
   {
     timer.Start();
   }
}

How to wrap text using CSS?

If you type "AAAAAAAAAAAAAAAAAAAAAARRRRRRRRRRRRRRRRRRRRRRGGGGGGGGGGGGGGGGGGGGG" this will produce:

AARRRRRRRRRRRRRRRRRRRR
RRGGGGGGGGGGGGGGGGGGGG
G

I have taken my example from a couple different websites on google. I have tested this on ff 5.0, IE 8.0, and Chrome 10. It works on all of them.

.wrapword {
    white-space: -moz-pre-wrap !important;  /* Mozilla, since 1999 */
    white-space: -pre-wrap;      /* Opera 4-6 */
    white-space: -o-pre-wrap;    /* Opera 7 */
    white-space: pre-wrap;       /* css-3 */
    word-wrap: break-word;       /* Internet Explorer 5.5+ */
    white-space: -webkit-pre-wrap; /* Newer versions of Chrome/Safari*/
    word-break: break-all;
    white-space: normal;
}

<table style="table-layout:fixed; width:400px">
    <tr>
        <td class="wrapword"></td>
    </tr>
</table>

connecting to MySQL from the command line

Use the following command to get connected to your MySQL database

mysql -u USERNAME -h HOSTNAME -p

Spring Boot and how to configure connection details to MongoDB?

It's also important to note that MongoDB has the concept of "authentication database", which can be different than the database you are connecting to. For example, if you use the official Docker image for Mongo and specify the environment variables MONGO_INITDB_ROOT_USERNAME and MONGO_INITDB_ROOT_PASSWORD, a user will be created on 'admin' database, which is probably not the database you want to use. In this case, you should specify parameters accordingly on your application.properties file using:

spring.data.mongodb.host=127.0.0.1
spring.data.mongodb.port=27017
spring.data.mongodb.authentication-database=admin
spring.data.mongodb.username=<username specified on MONGO_INITDB_ROOT_USERNAME>
spring.data.mongodb.password=<password specified on MONGO_INITDB_ROOT_PASSWORD>
spring.data.mongodb.database=<the db you want to use>

CSS background-size: cover replacement for Mobile Safari

That its the correct code of background size :

<div class="html-mobile-background">
</div>
<style type="text/css">
html {
    /* Whatever you want */
}
.html-mobile-background {
    position: fixed;
    z-index: -1;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%; /* To compensate for mobile browser address bar space */
    background: url(YOUR BACKGROUND URL HERE) no-repeat; 
 center center fixed; 
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;
 background-size: 100% 100%
}
</style>

Jquery to change form action

Please, see this answer: https://stackoverflow.com/a/3863869/2096619

Quoting Tamlyn:

jQuery (1.4.2) gets confused if you have any form elements named "action". You can get around this by using the DOM attribute methods or simply avoid having form elements named "action".

<form action="foo">
  <button name="action" value="bar">Go</button>
</form>

<script type="text/javascript">
  $('form').attr('action', 'baz'); //this fails silently
  $('form').get(0).setAttribute('action', 'baz'); //this works
</script>

Spring Security with roles and permissions

The basic steps are:

  1. Use a custom authentication provider

    <bean id="myAuthenticationProvider" class="myProviderImplementation" scope="singleton">
    ...
    </bean>
    

  2. Make your custom provider return a custom UserDetails implementation. This UserDetailsImpl will have a getAuthorities() like this:

    public Collection<GrantedAuthority> getAuthorities() {
        List<GrantedAuthority> permissions = new ArrayList<GrantedAuthority>();
        for (GrantedAuthority role: roles) {
            permissions.addAll(getPermissionsIncludedInRole(role));
        }
        return permissions;
    }
    

Of course from here you could apply a lot of optimizations/customizations for your specific requirements.

how to properly display an iFrame in mobile safari

I have put @Sharon's code together into the following, which works for me on the iPad with two-finger scrolling. The only thing you should have to change to get it working is the src attribute on the iframe (I used a PDF document).

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>Pdf Scrolling in mobile Safari</title>
</head>
<body>
<div id="scroller" style="height: 400px; width: 100%; overflow: auto;">
<iframe height="100%" id="iframe" scrolling="no" width="100%" id="iframe" src="data/testdocument.pdf" />
</div>
<script type="text/javascript">
    setTimeout(function () {
        var startY = 0;
        var startX = 0;
        var b = document.body;
        b.addEventListener('touchstart', function (event) {
            parent.window.scrollTo(0, 1);
            startY = event.targetTouches[0].pageY;
            startX = event.targetTouches[0].pageX;
        });
        b.addEventListener('touchmove', function (event) {
            event.preventDefault();
            var posy = event.targetTouches[0].pageY;
            var h = parent.document.getElementById("scroller");
            var sty = h.scrollTop;

            var posx = event.targetTouches[0].pageX;
            var stx = h.scrollLeft;
            h.scrollTop = sty - (posy - startY);
            h.scrollLeft = stx - (posx - startX);
            startY = posy;
            startX = posx;
        });
    }, 1000);
    </script>
</body>
</html>

How can I get the actual video URL of a YouTube live stream?

You need to get the HLS m3u8 playlist files from the video's manifest. There are ways to do this by hand, but for simplicity I'll be using the youtube-dl tool to get this information. I'll be using this live stream as an example: https://www.youtube.com/watch?v=_Gtc-GtLlTk

First, get the formats of the video:

?  ~ youtube-dl --list-formats https://www.youtube.com/watch\?v\=_Gtc-GtLlTk
[youtube] _Gtc-GtLlTk: Downloading webpage
[youtube] _Gtc-GtLlTk: Downloading video info webpage
[youtube] Downloading multifeed video (_Gtc-GtLlTk, aflWCT1tYL0) - add --no-playlist to just download video _Gtc-GtLlTk
[download] Downloading playlist: Southwest Florida Eagle Cam
[youtube] playlist Southwest Florida Eagle Cam: Collected 2 video ids (downloading 2 of them)
[download] Downloading video 1 of 2
[youtube] _Gtc-GtLlTk: Downloading webpage
[youtube] _Gtc-GtLlTk: Downloading video info webpage
[youtube] _Gtc-GtLlTk: Extracting video information
[youtube] _Gtc-GtLlTk: Downloading formats manifest
[youtube] _Gtc-GtLlTk: Downloading DASH manifest
[info] Available formats for _Gtc-GtLlTk:
format code  extension  resolution note
140          m4a        audio only DASH audio  144k , m4a_dash container, mp4a.40.2@128k (48000Hz)
160          mp4        256x144    DASH video  124k , avc1.42c00b, 30fps, video only
133          mp4        426x240    DASH video  258k , avc1.4d4015, 30fps, video only
134          mp4        640x360    DASH video  646k , avc1.4d401e, 30fps, video only
135          mp4        854x480    DASH video 1171k , avc1.4d401f, 30fps, video only
136          mp4        1280x720   DASH video 2326k , avc1.4d401f, 30fps, video only
137          mp4        1920x1080  DASH video 4347k , avc1.640028, 30fps, video only
151          mp4        72p        HLS , h264, aac  @ 24k
132          mp4        240p       HLS , h264, aac  @ 48k
92           mp4        240p       HLS , h264, aac  @ 48k
93           mp4        360p       HLS , h264, aac  @128k
94           mp4        480p       HLS , h264, aac  @128k
95           mp4        720p       HLS , h264, aac  @256k
96           mp4        1080p      HLS , h264, aac  @256k (best)
[download] Downloading video 2 of 2
[youtube] aflWCT1tYL0: Downloading webpage
[youtube] aflWCT1tYL0: Downloading video info webpage
[youtube] aflWCT1tYL0: Extracting video information
[youtube] aflWCT1tYL0: Downloading formats manifest
[youtube] aflWCT1tYL0: Downloading DASH manifest
[info] Available formats for aflWCT1tYL0:
format code  extension  resolution note
140          m4a        audio only DASH audio  144k , m4a_dash container, mp4a.40.2@128k (48000Hz)
160          mp4        256x144    DASH video  124k , avc1.42c00b, 30fps, video only
133          mp4        426x240    DASH video  258k , avc1.4d4015, 30fps, video only
134          mp4        640x360    DASH video  646k , avc1.4d401e, 30fps, video only
135          mp4        854x480    DASH video 1171k , avc1.4d401f, 30fps, video only
136          mp4        1280x720   DASH video 2326k , avc1.4d401f, 30fps, video only
151          mp4        72p        HLS , h264, aac  @ 24k
132          mp4        240p       HLS , h264, aac  @ 48k
92           mp4        240p       HLS , h264, aac  @ 48k
93           mp4        360p       HLS , h264, aac  @128k
94           mp4        480p       HLS , h264, aac  @128k
95           mp4        720p       HLS , h264, aac  @256k (best)
[download] Finished downloading playlist: Southwest Florida Eagle Cam

In this case, there are two videos because the live stream contains two cameras. From here, we need to get the HLS URL for a specific stream. Use -f to pass in the format you would like to watch, and -g to get that stream's URL:

?  ~ youtube-dl -f 95 -g https://www.youtube.com/watch\?v\=_Gtc-GtLlTk
https://manifest.googlevideo.com/api/manifest/hls_playlist/id/_Gtc-GtLlTk.2/itag/95/source/yt_live_broadcast/requiressl/yes/ratebypass/yes/live/1/cmbypass/yes/gir/yes/dg_shard/X0d0Yy1HdExsVGsuMg.95/hls_chunk_host/r1---sn-ab5l6ne6.googlevideo.com/playlist_type/LIVE/gcr/us/pmbypass/yes/mm/32/mn/sn-ab5l6ne6/ms/lv/mv/m/pl/20/dover/3/sver/3/fexp/9408495,9410706,9416126,9418581,9420452,9422596,9422780,9423059,9423661,9423662,9425349,9425959,9426661,9426720,9427325,9428422,9429306/upn/xmL7zNht848/mt/1456412649/ip/64.125.177.124/ipbits/0/expire/1456434315/sparams/ip,ipbits,expire,id,itag,source,requiressl,ratebypass,live,cmbypass,gir,dg_shard,hls_chunk_host,playlist_type,gcr,pmbypass,mm,mn,ms,mv,pl/signature/7E48A727654105FF82E158154FCBA7569D52521B.1FA117183C664F00B7508DDB81274644F520C27F/key/dg_yt0/playlist/index.m3u8
https://manifest.googlevideo.com/api/manifest/hls_playlist/id/aflWCT1tYL0.2/itag/95/source/yt_live_broadcast/requiressl/yes/ratebypass/yes/live/1/cmbypass/yes/gir/yes/dg_shard/YWZsV0NUMXRZTDAuMg.95/hls_chunk_host/r13---sn-ab5l6n7y.googlevideo.com/pmbypass/yes/playlist_type/LIVE/gcr/us/mm/32/mn/sn-ab5l6n7y/ms/lv/mv/m/pl/20/dover/3/sver/3/upn/vdBkD9lrq8Q/fexp/9408495,9410706,9416126,9418581,9420452,9422596,9422780,9423059,9423661,9423662,9425349,9425959,9426661,9426720,9427325,9428422,9429306/mt/1456412649/ip/64.125.177.124/ipbits/0/expire/1456434316/sparams/ip,ipbits,expire,id,itag,source,requiressl,ratebypass,live,cmbypass,gir,dg_shard,hls_chunk_host,pmbypass,playlist_type,gcr,mm,mn,ms,mv,pl/signature/4E83CD2DB23C2331CE349CE9AFE806C8293A01ED.880FD2E253FAC8FA56FAA304C78BD1D62F9D22B4/key/dg_yt0/playlist/index.m3u8

These are your HLS m3u8 playlists, one for each camera associated with the live stream.

Without youtube-dl, your flow might look like this:

Take your video id and make a GET request to the get_video_info endpoint:

HTTP GET: https://www.youtube.com/get_video_info?&video_id=_Gtc-GtLlTk&el=info&ps=default&eurl=&gl=US&hl=en

In the response, the hlsvp value will be the link to the m3u8 HLS playlist:

https://manifest.googlevideo.com/api/manifest/hls_variant/maudio/1/ipbits/0/key/yt6/ip/64.125.177.124/gcr/us/source/yt_live_broadcast/upn/BYS1YGuQtYI/id/_Gtc-GtLlTk.2/fexp/9416126%2C9416984%2C9417367%2C9420452%2C9422596%2C9423039%2C9423661%2C9423662%2C9423923%2C9425346%2C9427672%2C9428946%2C9429162/sparams/gcr%2Cid%2Cip%2Cipbits%2Citag%2Cmaudio%2Cplaylist_type%2Cpmbypass%2Csource%2Cexpire/sver/3/expire/1456449859/pmbypass/yes/playlist_type/LIVE/itag/0/signature/1E6874232CCAC397B601051699A03DC5A32F66D9.1CABCD9BFC87A2A886A29B86CF877077DD1AEEAA/file/index.m3u8

Convert a character digit to the corresponding integer in C

Subtract '0' like this:

int i = c - '0';

The C Standard guarantees each digit in the range '0'..'9' is one greater than its previous digit (in section 5.2.1/3 of the C99 draft). The same counts for C++.

Add a new item to recyclerview programmatically?

First add your item to mItems and then use:

mAdapter.notifyItemInserted(mItems.size() - 1);

this method is better than using:

mAdapter.notifyDataSetChanged();

in performance.

Disabling contextual LOB creation as createClob() method threw error

If you set:

hibernate.temp.use_jdbc_metadata_defaults: false

it can cause you troubles with PostgreSQL when your table name contains reserved word like user. After insert it will try to find id sequence with:

select currval('"user"_id_seq');

which will obviously fail. This at least with Hibernate 5.2.13 and Spring Boot 2.0.0.RC1. Haven't found other way to prevent this message so now just ignoring it.

Rounding a variable to two decimal places C#

Console.WriteLine(decimal.Round(pay,2));

Handling exceptions from Java ExecutorService tasks

If your ExecutorService comes from an external source (i. e. it's not possible to subclass ThreadPoolExecutor and override afterExecute()), you can use a dynamic proxy to achieve the desired behavior:

public static ExecutorService errorAware(final ExecutorService executor) {
    return (ExecutorService) Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(),
            new Class[] {ExecutorService.class},
            (proxy, method, args) -> {
                if (method.getName().equals("submit")) {
                    final Object arg0 = args[0];
                    if (arg0 instanceof Runnable) {
                        args[0] = new Runnable() {
                            @Override
                            public void run() {
                                final Runnable task = (Runnable) arg0;
                                try {
                                    task.run();
                                    if (task instanceof Future<?>) {
                                        final Future<?> future = (Future<?>) task;

                                        if (future.isDone()) {
                                            try {
                                                future.get();
                                            } catch (final CancellationException ce) {
                                                // Your error-handling code here
                                                ce.printStackTrace();
                                            } catch (final ExecutionException ee) {
                                                // Your error-handling code here
                                                ee.getCause().printStackTrace();
                                            } catch (final InterruptedException ie) {
                                                Thread.currentThread().interrupt();
                                            }
                                        }
                                    }
                                } catch (final RuntimeException re) {
                                    // Your error-handling code here
                                    re.printStackTrace();
                                    throw re;
                                } catch (final Error e) {
                                    // Your error-handling code here
                                    e.printStackTrace();
                                    throw e;
                                }
                            }
                        };
                    } else if (arg0 instanceof Callable<?>) {
                        args[0] = new Callable<Object>() {
                            @Override
                            public Object call() throws Exception {
                                final Callable<?> task = (Callable<?>) arg0;
                                try {
                                    return task.call();
                                } catch (final Exception e) {
                                    // Your error-handling code here
                                    e.printStackTrace();
                                    throw e;
                                } catch (final Error e) {
                                    // Your error-handling code here
                                    e.printStackTrace();
                                    throw e;
                                }
                            }
                        };
                    }
                }
                return method.invoke(executor, args);
            });
}

OpenCV with Network Cameras

I just do it like this:

CvCapture *capture = cvCreateFileCapture("rtsp://camera-address");

Also make sure this dll is available at runtime else cvCreateFileCapture will return NULL

opencv_ffmpeg200d.dll

The camera needs to allow unauthenticated access too, usually set via its web interface. MJPEG format worked via rtsp but MPEG4 didn't.

hth

Si

How to get the integer value of day of week

day1= (int)ClockInfoFromSystem.DayOfWeek;

How can I write maven build to add resources to classpath?

A cleaner alternative of putting your config file into a subfolder of src/main/resources would be to enhance your classpath locations. This is extremely easy to do with Maven.

For instance, place your property file in a new folder src/main/config, and add the following to your pom:

 <build>
    <resources>
        <resource>
            <directory>src/main/config</directory>
        </resource>
    </resources>
 </build>

From now, every files files under src/main/config is considered as part of your classpath (note that you can exclude some of them from the final jar if needed: just add in the build section:

    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <configuration>
                <excludes>
                    <exclude>my-config.properties</exclude>
                </excludes>
            </configuration>
        </plugin>
    </plugins>

so that my-config.properties can be found in your classpath when you run your app from your IDE, but will remain external from your jar in your final distribution).

onMeasure custom view explanation

onMeasure() is your opportunity to tell Android how big you want your custom view to be dependent the layout constraints provided by the parent; it is also your custom view's opportunity to learn what those layout constraints are (in case you want to behave differently in a match_parent situation than a wrap_content situation). These constraints are packaged up into the MeasureSpec values that are passed into the method. Here is a rough correlation of the mode values:

  • EXACTLY means the layout_width or layout_height value was set to a specific value. You should probably make your view this size. This can also get triggered when match_parent is used, to set the size exactly to the parent view (this is layout dependent in the framework).
  • AT_MOST typically means the layout_width or layout_height value was set to match_parent or wrap_content where a maximum size is needed (this is layout dependent in the framework), and the size of the parent dimension is the value. You should not be any larger than this size.
  • UNSPECIFIED typically means the layout_width or layout_height value was set to wrap_content with no restrictions. You can be whatever size you would like. Some layouts also use this callback to figure out your desired size before determine what specs to actually pass you again in a second measure request.

The contract that exists with onMeasure() is that setMeasuredDimension() MUST be called at the end with the size you would like the view to be. This method is called by all the framework implementations, including the default implementation found in View, which is why it is safe to call super instead if that fits your use case.

Granted, because the framework does apply a default implementation, it may not be necessary for you to override this method, but you may see clipping in cases where the view space is smaller than your content if you do not, and if you lay out your custom view with wrap_content in both directions, your view may not show up at all because the framework doesn't know how large it is!

Generally, if you are overriding View and not another existing widget, it is probably a good idea to provide an implementation, even if it is as simple as something like this:

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

    int desiredWidth = 100;
    int desiredHeight = 100;

    int widthMode = MeasureSpec.getMode(widthMeasureSpec);
    int widthSize = MeasureSpec.getSize(widthMeasureSpec);
    int heightMode = MeasureSpec.getMode(heightMeasureSpec);
    int heightSize = MeasureSpec.getSize(heightMeasureSpec);

    int width;
    int height;

    //Measure Width
    if (widthMode == MeasureSpec.EXACTLY) {
        //Must be this size
        width = widthSize;
    } else if (widthMode == MeasureSpec.AT_MOST) {
        //Can't be bigger than...
        width = Math.min(desiredWidth, widthSize);
    } else {
        //Be whatever you want
        width = desiredWidth;
    }

    //Measure Height
    if (heightMode == MeasureSpec.EXACTLY) {
        //Must be this size
        height = heightSize;
    } else if (heightMode == MeasureSpec.AT_MOST) {
        //Can't be bigger than...
        height = Math.min(desiredHeight, heightSize);
    } else {
        //Be whatever you want
        height = desiredHeight;
    }

    //MUST CALL THIS
    setMeasuredDimension(width, height);
}

Hope that Helps.

java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1888, result=0, data=null} to activity

this is my case

startActivityForResult(intent, PICK_IMAGE_REQUEST);

I defined two request code PICK_IMAGE_REQUESTand SCAN_BARCODE_REQUEST with the same value, eg.

static final int BARCODE_SCAN_REQUEST = 1;

static final int PICK_IMAGE_REQUEST = 1;

this could also causes the problem

How do I specify different Layouts in the ASP.NET MVC 3 razor ViewStart file?

You could put a _ViewStart.cshtml file inside the /Views/Public folder which would override the default one in the /Views folder and specify the desired layout:

@{
    Layout = "~/Views/Shared/_PublicLayout.cshtml";
}

By analogy you could put another _ViewStart.cshtml file inside the /Views/Staff folder with:

@{
    Layout = "~/Views/Shared/_StaffLayout.cshtml";
}

You could also specify which layout should be used when returning a view inside a controller action but that's per action:

return View("Index", "~/Views/Shared/_StaffLayout.cshtml", someViewModel);

Yet another possibility is a custom action filter which would override the layout. As you can see many possibilities to achieve this. Up to you to choose which one fits best in your scenario.


UPDATE:

As requested in the comments section here's an example of an action filter which would choose a master page:

public class LayoutInjecterAttribute : ActionFilterAttribute
{
    private readonly string _masterName;
    public LayoutInjecterAttribute(string masterName)
    {
        _masterName = masterName;
    }

    public override void OnActionExecuted(ActionExecutedContext filterContext)
    {
        base.OnActionExecuted(filterContext);
        var result = filterContext.Result as ViewResult;
        if (result != null)
        {
            result.MasterName = _masterName;
        }
    }
}

and then decorate a controller or an action with this custom attribute specifying the layout you want:

[LayoutInjecter("_PublicLayout")]
public ActionResult Index()
{
    return View();
}

Padding a table row

The trick is to give padding on the td elements, but make an exception for the first (yes, it's hacky, but sometimes you have to play by the browser's rules):

td {
  padding-top:20px;
  padding-bottom:20px;
  padding-right:20px;   
}

td:first-child {
  padding-left:20px;
  padding-right:0;
}

First-child is relatively well supported: https://developer.mozilla.org/en-US/docs/CSS/:first-child

You can use the same reasoning for the horizontal padding by using tr:first-child td.

Alternatively, exclude the first column by using the not operator. Support for this is not as good right now, though.

td:not(:first-child) {
  padding-top:20px;
  padding-bottom:20px;
  padding-right:20px;       
}

Convert a video to MP4 (H.264/AAC) with ffmpeg

You're trying to convert a (rather rare) .flv file that (already) contains H.264 video and AAC audio.

Formatting your console's output as FFmpeg brings out these details.

 Input #0, flv, from 'video.flv':
   Duration: 00:05:01.20, start: 0.000000, bitrate: 66 kb/s
    Stream #0.0: Video: h264, yuv420p, 320x240 [PAR 1:1 DAR 4:3], 66 kb/s, 29.92 tbr, 1k tbn, 2k tbc 
    Stream #0.1: Audio: aac, 22050 Hz, stereo, s16

The original flv is converted to an .mp4 file with H.264 video and AAC audio (just like the original .flv):

Output #0, mp4, to 'video.mp4': 
    Stream #0.0: Video: mpeg4, yuv420p, 320x240 [PAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 90k tbn, 29.92 tbc 
    Stream #0.1: Audio: 0x0000, 22050 Hz, stereo, s16, 64 kb/s

Because the audio and video data in the .flv are already in the format/codecs you need for the .mp4, you can just copy everything to the new .mp4 container. This process will be massively faster than decoding and reencoding everything:

ffmpeg -i video.flv -vcodec copy -acodec copy video.mp4

or more simply:

ffmpeg -i video.flv -codec copy video.mp4

The real error you're getting is:

Unsupported codec for output stream #0.1

Which means FFmpeg can't convert audio (stream #0.1) to AAC.

You can skip the error by:

  • copying the audio data since it's already AAC encoded (use the copy command above)

or you can solve the error by:

For more details you should also read Converting FLV to MP4 With FFmpeg The Ultimate Guide

Android checkbox style

Maybe this will satisfy you -

something.xml

<CheckBox
    android:text="Custom CheckBox"
    android:button="@drawable/checkbox_selector"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"/>

Selector

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_checked="true" android:drawable="@drawable/star_down" />
    <item android:state_checked="false" android:drawable="@drawable/star" />
</selector>

For, the reference just refer here

How to return a value from a Form in C#?

If you want to pass data to form2 from form1 without passing like new form(sting "data");

Do like that in form 1

using (Form2 form2= new Form2())
{
   form2.ReturnValue1 = "lalala";
   form2.ShowDialog();
}

in form 2 add

public string ReturnValue1 { get; set; }

private void form2_Load(object sender, EventArgs e)
{
   MessageBox.Show(ReturnValue1);
}

Also you can use value in form1 like this if you want to swap something in form1

just in form1

textbox.Text =form2.ReturnValue1

Getting Textarea Value with jQuery

change id="#message" to id="message" on your textarea element.

and by the way, just use this:

$('#send-thoughts')

remember that you should only use ID's once and you can use classes over and over.

https://css-tricks.com/the-difference-between-id-and-class/

MongoDB vs. Cassandra

Why choose between a traditional database and a NoSQL data store? Use both! The problem with NoSQL solutions (beyond the initial learning curve) is the lack of transactions -- you do all updates to MySQL and have MySQL populate a NoSQL data store for reads -- you then benefit from each technology's strengths. This does add more complexity, but you already have the MySQL side -- just add MongoDB, Cassandra, etc to the mix.

NoSQL datastores generally scale way better than a traditional DB for the same otherwise specs -- there is a reason why Facebook, Twitter, Google, and most start-ups are using NoSQL solutions. It's not just geeks getting high on new tech.

MySQL: @variable vs. variable. What's the difference?

MSSQL requires that variables within procedures be DECLAREd and folks use the @Variable syntax (DECLARE @TEXT VARCHAR(25) = 'text'). Also, MS allows for declares within any block in the procedure, unlike mySQL which requires all the DECLAREs at the top.

While good on the command line, I feel using the "set = @variable" within stored procedures in mySQL is risky. There is no scope and variables live across scope boundaries. This is similar to variables in JavaScript being declared without the "var" prefix, which are then the global namespace and create unexpected collisions and overwrites.

I am hoping that the good folks at mySQL will allow DECLARE @Variable at various block levels within a stored procedure. Notice the @ (at sign). The @ sign prefix helps to separate variable names from table column names - as they are often the same. Of course, one can always add an "v" or "l_" prefix, but the @ sign is a handy and succinct way to have the variable name match the column you might be extracting the data from without clobbering it.

MySQL is new to stored procedures and they have done a good job for their first version. It will be a pleaure to see where they take it form here and to watch the server side aspects of the language mature.

How to see full query from SHOW PROCESSLIST

If one want to keep getting updated processes (on the example, 2 seconds) on a shell session without having to manually interact with it use:

watch -n 2 'mysql -h 127.0.0.1 -P 3306 -u some_user -psome_pass some_database -e "show full processlist;"'

The only bad thing about the show [full] processlist is that you can't filter the output result. On the other hand, issuing the SELECT * FROM INFORMATION_SCHEMA.PROCESSLIST open possibilities to remove from the output anything you don't want to see:

SELECT * from INFORMATION_SCHEMA.PROCESSLIST
WHERE DB = 'somedatabase'
AND COMMAND <> 'Sleep'
AND HOST NOT LIKE '10.164.25.133%' \G

Java: Reading a file into an array

Here is some example code to help you get started:

package com.acme;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class FileArrayProvider {

    public String[] readLines(String filename) throws IOException {
        FileReader fileReader = new FileReader(filename);
        BufferedReader bufferedReader = new BufferedReader(fileReader);
        List<String> lines = new ArrayList<String>();
        String line = null;
        while ((line = bufferedReader.readLine()) != null) {
            lines.add(line);
        }
        bufferedReader.close();
        return lines.toArray(new String[lines.size()]);
    }
}

And an example unit test:

package com.acme;

import java.io.IOException;

import org.junit.Test;

public class FileArrayProviderTest {

    @Test
    public void testFileArrayProvider() throws IOException {
        FileArrayProvider fap = new FileArrayProvider();
        String[] lines = fap
                .readLines("src/main/java/com/acme/FileArrayProvider.java");
        for (String line : lines) {
            System.out.println(line);
        }
    }
}

Hope this helps.

How to detect if multiple keys are pressed at once using JavaScript?

You should use the keydown event to keep track of the keys pressed, and you should use the keyup event to keep track of when the keys are released.

See this example: http://jsfiddle.net/vor0nwe/mkHsU/

(Update: I’m reproducing the code here, in case jsfiddle.net bails:) The HTML:

<ul id="log">
    <li>List of keys:</li>
</ul>

...and the Javascript (using jQuery):

var log = $('#log')[0],
    pressedKeys = [];

$(document.body).keydown(function (evt) {
    var li = pressedKeys[evt.keyCode];
    if (!li) {
        li = log.appendChild(document.createElement('li'));
        pressedKeys[evt.keyCode] = li;
    }
    $(li).text('Down: ' + evt.keyCode);
    $(li).removeClass('key-up');
});

$(document.body).keyup(function (evt) {
    var li = pressedKeys[evt.keyCode];
    if (!li) {
       li = log.appendChild(document.createElement('li'));
    }
    $(li).text('Up: ' + evt.keyCode);
    $(li).addClass('key-up');
});

In that example, I’m using an array to keep track of which keys are being pressed. In a real application, you might want to delete each element once their associated key has been released.

Note that while I've used jQuery to make things easy for myself in this example, the concept works just as well when working in 'raw' Javascript.

Difference between char* and const char*?

The question is what's the difference between

char *name

which points to a constant string literal, and

const char *cname

I.e. given

char *name = "foo";

and

const char *cname = "foo";

There is not much difference between the 2 and both can be seen as correct. Due to the long legacy of C code, the string literals have had a type of char[], not const char[], and there are lots of older code that likewise accept char * instead of const char *, even when they do not modify the arguments.

The principal difference of the 2 in general is that *cname or cname[n] will evaluate to lvalues of type const char, whereas *name or name[n] will evaluate to lvalues of type char, which are modifiable lvalues. A conforming compiler is required to produce a diagnostics message if target of the assignment is not a modifiable lvalue; it need not produce any warning on assignment to lvalues of type char:

name[0] = 'x'; // no diagnostics *needed*
cname[0] = 'x'; // a conforming compiler *must* produce a diagnostic message

The compiler is not required to stop the compilation in either case; it is enough that it produces a warning for the assignment to cname[0]. The resulting program is not a correct program. The behaviour of the construct is undefined. It may crash, or even worse, it might not crash, and might change the string literal in memory.

Creating a segue programmatically

I've been using this code to instantiate my custom segue subclass and run it programmatically. It seems to work. Anything wrong with this? I'm puzzled, reading all the other answers saying it cannot be done.

UIViewController *toViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"OtherViewControllerId"];
MyCustomSegue *segue = [[MyCustomSegue alloc] initWithIdentifier:@"" source:self destination:toViewController];
[self prepareForSegue:segue sender:sender];
[segue perform];

argparse module How to add option without any argument?

As @Felix Kling suggested use action='store_true':

>>> from argparse import ArgumentParser
>>> p = ArgumentParser()
>>> _ = p.add_argument('-f', '--foo', action='store_true')
>>> args = p.parse_args()
>>> args.foo
False
>>> args = p.parse_args(['-f'])
>>> args.foo
True

How can I check if an element exists in the visible DOM?

I simply do:

if(document.getElementById("myElementId")){
    alert("Element exists");
} else {
    alert("Element does not exist");
}

It works for me and had no issues with it yet...

How to query DATETIME field using only date in Microsoft SQL Server?

Test this query.

SELECT *,DATE(chat_reg_date) AS is_date,TIME(chat_reg_time) AS is_time FROM chat WHERE chat_inbox_key='$chat_key' 
                         ORDER BY is_date DESC, is_time DESC

How to get the path of the batch script in Windows?

You can use following script to get the path without trailing "\"

for %%i in ("%~dp0.") do SET "mypath=%%~fi"

What is the "Illegal Instruction: 4" error and why does "-mmacosx-version-min=10.x" fix it?

I found my issue was an improper
if (leaf = NULL) {...}
where it should have been
if (leaf == NULL){...}

Check those compiler warnings!

How do I pretty-print existing JSON data with Java?

int spacesToIndentEachLevel = 2;
new JSONObject(jsonString).toString(spacesToIndentEachLevel);

Using org.json.JSONObject (built in to JavaEE and Android)

IIS7: Setup Integrated Windows Authentication like in IIS6

So do you want them to get the IE password-challenge box, or should they be directed to your login page and enter their information there? If it's the second option, then you should at least enable Anonymous access to your login page, since the site won't know who they are yet.

If you want the first option, then the login page they're getting forwarded to will need to read the currently logged-in user and act based on that, since they would have had to correctly authenticate to get this far.

Get user profile picture by Id

Here, this api allows you to get fb, google and twitter profile pics easily

https://www.avatars.io/

It's an API that returns the profile image when given a username for a variety of social networks including Twitter, Facebook, Instagram, and gravatar. It has libraries for iOS, Android, Ruby, Node, PHP, Python, and JavaScript.

Get properties of a class

I am currently working on a Linq-like library for Typescript and wanted to implement something like GetProperties of C# in Typescript / Javascript. The more I work with Typescript and generics, the clearer picture I get of that you usually have to have an instantiated object with intialized properties to get any useful information out at runtime about properties of a class. But it would be nice to retrieve information anyways just from the constructor function object, or an array of objects and be flexible about this.

Here is what I ended up with for now.

First off, I define Array prototype method ('extension method' for you C# developers).

export { } //creating a module of below code
declare global {
  interface Array<T> {
    GetProperties<T>(TClass: Function, sortProps: boolean): string[];
} }

The GetProperties method then looks like this, inspired by madreason's answer.

if (!Array.prototype.GetProperties) {
  Array.prototype.GetProperties = function <T>(TClass: any = null, sortProps: boolean = false): string[] {
    if (TClass === null || TClass === undefined) {
      if (this === null || this === undefined || this.length === 0) {
        return []; //not possible to find out more information - return empty array
      }
    }
    // debugger
    if (TClass !== null && TClass !== undefined) {
      if (this !== null && this !== undefined) {
        if (this.length > 0) {
          let knownProps: string[] = Describer.describe(this[0]).Where(x => x !== null && x !== undefined);
          if (sortProps && knownProps !== null && knownProps !== undefined) {
            knownProps = knownProps.OrderBy(p => p);
          }
          return knownProps;
        }
        if (TClass !== null && TClass !== undefined) {
          let knownProps: string[] = Describer.describe(TClass).Where(x => x !== null && x !== undefined);
          if (sortProps && knownProps !== null && knownProps !== undefined) {
            knownProps = knownProps.OrderBy(p => p);
          }
          return knownProps;
        }
      }
    }
    return []; //give up..
  }
}

The describer method is about the same as madreason's answer. It can handle both class Function and if you get an object instead. It will then use Object.getOwnPropertyNames if no class Function is given (i.e. the class 'type' for C# developers).

class Describer {
  private static FRegEx = new RegExp(/(?:this\.)(.+?(?= ))/g);
  static describe(val: any, parent = false): string[] {
    let isFunction = Object.prototype.toString.call(val) == '[object Function]';
    if (isFunction) {
      let result = [];
      if (parent) {
        var proto = Object.getPrototypeOf(val.prototype);
        if (proto) {
          result = result.concat(this.describe(proto.constructor, parent));
        }
      }
      result = result.concat(val.toString().match(this.FRegEx));
      result = result.Where(r => r !== null && r !== undefined);
      return result;
    }
    else {
      if (typeof val == "object") {
        let knownProps: string[] = Object.getOwnPropertyNames(val);
        return knownProps;
      }
    }
    return val !== null ? [val.tostring()] : [];
  }
}

Here you see two specs for testing this out with Jasmine.

class Hero {
  name: string;
  gender: string;
  age: number;
  constructor(name: string = "", gender: string = "", age: number = 0) {
    this.name = name;
    this.gender = gender;
    this.age = age;
  }
}

class HeroWithAbility extends Hero {
  ability: string;
  constructor(ability: string = "") {
    super();
    this.ability = ability;
  }
}

describe('Array Extensions tests for TsExtensions Linq esque library', () => {

  it('can retrieve props for a class items of an array', () => {
    let heroes: Hero[] = [<Hero>{ name: "Han Solo", age: 44, gender: "M" }, <Hero>{ name: "Leia", age: 29, gender: "F" }, <Hero>{ name: "Luke", age: 24, gender: "M" }, <Hero>{ name: "Lando", age: 47, gender: "M" }];
    let foundProps = heroes.GetProperties(Hero, false);
    //debugger
    let expectedArrayOfProps = ["name", "age", "gender"];
    expect(foundProps).toEqual(expectedArrayOfProps);
    expect(heroes.GetProperties(Hero, true)).toEqual(["age", "gender", "name"]);
  });

  it('can retrieve props for a class only knowing its function', () => {
    let heroes: Hero[] = [];
    let foundProps = heroes.GetProperties(Hero, false);
    let expectedArrayOfProps = ["this.name", "this.gender", "this.age"];
    expect(foundProps).toEqual(expectedArrayOfProps);
    let foundPropsThroughClassFunction = heroes.GetProperties(Hero, true);
    //debugger
    expect(foundPropsThroughClassFunction.SequenceEqual(["this.age", "this.gender", "this.name"])).toBe(true);
  });

And as madreason mentioned, you have to initialize the props to get any information out from just the class Function itself, or else it is stripped away when Typescript code is turned into Javascript code.

Typescript 3.7 is very good with Generics, but coming from a C# and Reflection background, some fundamental parts of Typescript and generics still feels somewhat loose and unfinished business. Like my code here, but at least I got out the information I wanted - a list of property names for a given class or instance of objects.

SequenceEqual is this method btw:

    if (!Array.prototype.SequenceEqual) {
  Array.prototype.SequenceEqual = function <T>(compareArray: T): boolean {
    if (!Array.isArray(this) || !Array.isArray(compareArray) || this.length !== compareArray.length)
      return false;
    var arr1 = this.concat().sort();
    var arr2 = compareArray.concat().sort();
    for (var i = 0; i < arr1.length; i++) {
      if (arr1[i] !== arr2[i])
        return false;
    }
    return true;
  }
}

Restoring database from .mdf and .ldf files of SQL Server 2008

this is what i did

first execute create database x. x is the name of your old database eg the name of the mdf.

Then open sql sever configration and stop the sql sever.

There after browse to the location of your new created database it should be under program file, in my case is

C:\Program Files\Microsoft SQL Server\MSSQL14.MSSQL\MSSQL\DATA

and repleace the new created mdf and Idf with the old files/database.

then simply restart the sql server and walla :)

Using XAMPP, how do I swap out PHP 5.3 for PHP 5.2?

You'll have to uninstall XAMPP 1.7.2 and install XAMPP 1.7.0, which contains PHP 5.2.8.

D:\Documents and Settings\box>php -v

PHP 5.2.8 (cli) (built: Dec  8 2008 19:31:23)
Copyright (c) 1997-2008 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2008 Zend Technologies
    with Zend Extension Manager v1.2.0, Copyright (c) 2003-2007, by Zend Technol
ogies
    with Zend Optimizer v3.3.3, Copyright (c) 1998-2007, by Zend Technologies

XAMPP 1.6.8 contains PHP 5.2.6.

D:\Documents and Settings\box>php -v
PHP 5.2.6 (cli) (built: May  2 2008 18:02:07)
Copyright (c) 1997-2008 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2008 Zend Technologies
    with Zend Extension Manager v1.2.0, Copyright (c) 2003-2007, by Zend Technol
ogies
    with Zend Optimizer v3.3.3, Copyright (c) 1998-2007, by Zend Technologies

How do I create a MongoDB dump of my database?

Use mongodump:

$ ./mongodump --host prod.example.com
connected to: prod.example.com
all dbs
DATABASE: log    to   dump/log
        log.errors to dump/log/errors.bson
                713 objects
        log.analytics to dump/log/analytics.bson
                234810 objects
DATABASE: blog    to    dump/blog
        blog.posts to dump/log/blog.posts.bson
                59 objects
DATABASE: admin    to    dump/admin

Source: http://www.mongodb.org/display/DOCS/Import+Export+Tools

How to use EditText onTextChanged event when I press the number?

Here, I wrote something similar to what u need:

    inputBoxNumberEt.setText(".     ");
    inputBoxNumberEt.setSelection(inputBoxNumberEt.getText().length());
    inputBoxNumberEt.addTextChangedListener(new TextWatcher() {

        boolean ignoreChange = false;

        @Override
        public void afterTextChanged(Editable s) {
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start,
                                      int count, int after) {
        }

        @Override
        public void onTextChanged(CharSequence s, int start,
                                  int before, int count) {
            if (!ignoreChange) {
                String string = s.toString();
                string = string.replace(".", "");
                string = string.replace(" ", "");
                if (string.length() == 0)
                    string = ".     ";
                else if (string.length() == 1)
                    string = ".  " + string;
                else if (string.length() == 2)
                    string = "." + string;
                else if (string.length() > 2)
                    string = string.substring(0, string.length() - 2) + "." + string.substring(string.length() - 2, string.length());
                ignoreChange = true;
                inputBoxNumberEt.setText(string);
                inputBoxNumberEt.setSelection(inputBoxNumberEt.getText().length());
                ignoreChange = false;
            }
        }
    });

How to turn on WCF tracing?

The following configuration taken from MSDN can be applied to enable tracing on your WCF service.

<configuration>
  <system.diagnostics>
    <sources>
      <source name="System.ServiceModel"
              switchValue="Information, ActivityTracing"
              propagateActivity="true" >
        <listeners>
             <add name="xml"/>
        </listeners>
      </source>
      <source name="System.ServiceModel.MessageLogging">
        <listeners>
            <add name="xml"/>
        </listeners>
      </source>
      <source name="myUserTraceSource"
              switchValue="Information, ActivityTracing">
        <listeners>
            <add name="xml"/>
        </listeners>
      </source>
    </sources>
    <sharedListeners>
        <add name="xml"
             type="System.Diagnostics.XmlWriterTraceListener"
             initializeData="Error.svclog" />
    </sharedListeners>
  </system.diagnostics>
</configuration>

To view the log file, you can use "C:\Program Files\Microsoft SDKs\Windows\v7.0A\bin\SvcTraceViewer.exe".

If "SvcTraceViewer.exe" is not on your system, you can download it from the "Microsoft Windows SDK for Windows 7 and .NET Framework 4" package here:

Windows SDK Download

You don't have to install the entire thing, just the ".NET Development / Tools" part.

When/if it bombs out during installation with a non-sensical error, Petopas' answer to Windows 7 SDK Installation Failure solved my issue.

Java - get the current class name?

Try using this this.getClass().getCanonicalName() or this.getClass().getSimpleName(). If it's an anonymous class, use this.getClass().getSuperclass().getName()

"break;" out of "if" statement?

This is actually the conventional use of the break statement. If the break statement wasn't nested in an if block the for loop could only ever execute one time.

MSDN lists this as their example for the break statement.

Using Jasmine to spy on a function without an object

TypeScript users:

I know the OP asked about javascript, but for any TypeScript users who come across this who want to spy on an imported function, here's what you can do.

In the test file, convert the import of the function from this:

import {foo} from '../foo_functions';

x = foo(y);

To this:

import * as FooFunctions from '../foo_functions';

x = FooFunctions.foo(y);

Then you can spy on FooFunctions.foo :)

spyOn(FooFunctions, 'foo').and.callFake(...);
// ...
expect(FooFunctions.foo).toHaveBeenCalled();

Is it possible to apply CSS to half of a character?

If you are interested in this, then Lucas Bebber's Glitch is a very similar and super cool effect:

enter image description here

Created using a simple SASS Mixin such as

.example-one {
  font-size: 100px;
  @include textGlitch("example-one", 17, white, black, red, blue, 450, 115);
}

More details at Chris Coyer's CSS Tricks and Lucas Bebber's Codepen page

How to get the last element of an array in Ruby?

One other way, using the splat operator:

*a, last = [1, 3, 4, 5]

STDOUT:
a: [1, 3, 4]
last: 5

Why does Date.parse give incorrect results?

There is some method to the madness. As a general rule, if a browser can interpret a date as an ISO-8601, it will. "2005-07-08" falls into this camp, and so it is parsed as UTC. "Jul 8, 2005" cannot, and so it is parsed in the local time.

See JavaScript and Dates, What a Mess! for more.