Programs & Examples On #Teechart

TeeChart is a commercial set of powerful charting components originally written for Delphi. A basic component called TChart is included in every Delphi IDE supporting VCL and FireMonkey frameworks. TeeChart is also available for major languages: .NET Framework, Xamarin (including Android, iOS and Forms) Java (including Swing, SWT and Android), ActiveX, Javascript/HTML5 and PHP.

Use jQuery to scroll to the bottom of a div with lots of text

No need to calculate the actual height of the contents; you can just scroll down a lot:

$(function () {
  $('.messageScrollArea').scrollTop(1E10);
});

What is thread Safe in java?

Thread safe simply means that it may be used from multiple threads at the same time without causing problems. This can mean that access to any resources are synchronized, or whatever.

Prevent row names to be written to file when using write.csv

write.csv(t, "t.csv", row.names=FALSE)

From ?write.csv:

row.names: either a logical value indicating whether the row names of
          ‘x’ are to be written along with ‘x’, or a character vector
          of row names to be written.

Excel: macro to export worksheet as CSV file without leaving my current Excel sheet

Almost what I wanted @Ralph, but here is the best answer. It'll solve your code problems:

  1. it exports just the hardcoded sheet named "Sheet1";
  2. it always exports to the same temp file, overwriting it;
  3. it ignores the locale separation char.

To solve these problems, and meet all my requirements, I've adapted the code from here. I've cleaned it a little to make it more readable.

Option Explicit
Sub ExportAsCSV()
 
    Dim MyFileName As String
    Dim CurrentWB As Workbook, TempWB As Workbook
     
    Set CurrentWB = ActiveWorkbook
    ActiveWorkbook.ActiveSheet.UsedRange.Copy
 
    Set TempWB = Application.Workbooks.Add(1)
    With TempWB.Sheets(1).Range("A1")
      .PasteSpecial xlPasteValues
      .PasteSpecial xlPasteFormats
    End With        

    Dim Change below to "- 4"  to become compatible with .xls files
    MyFileName = CurrentWB.Path & "\" & Left(CurrentWB.Name, Len(CurrentWB.Name) - 5) & ".csv"
     
    Application.DisplayAlerts = False
    TempWB.SaveAs Filename:=MyFileName, FileFormat:=xlCSV, CreateBackup:=False, Local:=True
    TempWB.Close SaveChanges:=False
    Application.DisplayAlerts = True
End Sub

There are still some small thing with the code above that you should notice:

  1. .Close and DisplayAlerts=True should be in a finally clause, but I don't know how to do it in VBA
  2. It works just if the current filename has 4 letters, like .xlsm. Wouldn't work in .xls excel old files. For file extensions of 3 chars, you must change the - 5 to - 4 when setting MyFileName.
  3. As a collateral effect, your clipboard will be substituted with current sheet contents.

Edit: put Local:=True to save with my locale CSV delimiter.

versionCode vs versionName in Android Manifest

Version Code - It's a positive integer that's used for comparison with other version codes. It's not shown to the user, it's just for record-keeping in a way. You can set it to any integer you like but it's suggested that you linearly increment it for successive versions.

Version Name - This is the version string seen by the user. It isn't used for internal comparisons or anything, it's just for users to see.

For example: Say you release an app, its initial versionCode could be 1 and versionName could also be 1. Once you make some small changes to the app and want to publish an update, you would set versionName to "1.1" (since the changes aren't major) while logically your versionCode should be 2 (regardless of size of changes).

Say in another condition you release a completely revamped version of your app, you could set versionCode and versionName to "2".

Hope that helps.

You can read more about it here

$.browser is undefined error

The .browser call has been removed in jquery 1.9 have a look at http://jquery.com/upgrade-guide/1.9/ for more details.

I can’t find the Android keytool

No need to use the command line.

If you FILE-> "Export Android Application" in the ADK then it will allow you to create a key and then produce your .apk file.

What is the difference between tinyint, smallint, mediumint, bigint and int in MySQL?

Data type Range Storage

bigint  -2^63 (-9,223,372,036,854,775,808) to 2^63-1 (9,223,372,036,854,775,807)    8 Bytes
int -2^31 (-2,147,483,648) to 2^31-1 (2,147,483,647)    4 Bytes
smallint    -2^15 (-32,768) to 2^15-1 (32,767)  2 Bytes
tinyint 0 to 255    1 Byte

Example

The following example creates a table using the bigint, int, smallint, and tinyint data types. Values are inserted into each column and returned in the SELECT statement.

CREATE TABLE dbo.MyTable
(
  MyBigIntColumn bigint
 ,MyIntColumn  int
 ,MySmallIntColumn smallint
 ,MyTinyIntColumn tinyint
);

GO

INSERT INTO dbo.MyTable VALUES (9223372036854775807, 214483647,32767,255);
 GO
SELECT MyBigIntColumn, MyIntColumn, MySmallIntColumn, MyTinyIntColumn
FROM dbo.MyTable;

ng if with angular for string contains

ng-if="select.name.indexOf('?') !== -1" 

UIView background color in Swift

I see that this question is solved, but, I want to add some information than can help someone.

if you want use hex to set background color, I found this function and work:

func UIColorFromHex(rgbValue:UInt32, alpha:Double=1.0)->UIColor {
    let red = CGFloat((rgbValue & 0xFF0000) >> 16)/256.0
    let green = CGFloat((rgbValue & 0xFF00) >> 8)/256.0
    let blue = CGFloat(rgbValue & 0xFF)/256.0

    return UIColor(red:red, green:green, blue:blue, alpha:CGFloat(alpha))
}

I use this function as follows:

view.backgroundColor = UIColorFromHex(0x323232,alpha: 1)

some times you must use self:

self.view.backgroundColor = UIColorFromHex(0x323232,alpha: 1)

Well that was it, I hope it helps someone .

sorry for my bad english.

this work on iOS 7.1+

How do I work with a git repository within another repository?

If I understand your problem well you want the following things:

  1. Have your media files stored in one single git repository, which is used by many projects
  2. If you modify a media file in any of the projects in your local machine, it should immediately appear in every other project (so you don't want to commit+push+pull all the time)

Unfortunately there is no ultimate solution for what you want, but there are some things by which you can make your life easier.

First you should decide one important thing: do you want to store for every version in your project repository a reference to the version of the media files? So for example if you have a project called example.com, do you need know which style.css it used 2 weeks ago, or the latest is always (or mostly) the best?

If you don't need to know that, the solution is easy:

  1. create a repository for the media files and one for each project
  2. create a symbolic link in your projects which point to the locally cloned media repository. You can either create a relative symbolic link (e.g. ../media) and assume that everybody will checkout the project so that the media directory is in the same place, or write the name of the symbolic link into .gitignore, and everybody can decide where he/she puts the media files.

In most of the cases, however, you want to know this versioning information. In this case you have two choices:

  1. Store every project in one big repository. The advantage of this solution is that you will have only 1 copy of the media repository. The big disadvantage is that it is much harder to switch between project versions (if you checkout to a different version you will always modify ALL projects)

  2. Use submodules (as explained in answer 1). This way you will store the media files in one repository, and the projects will contain only a reference to a specific media repo version. But this way you will normally have many local copies of the media repository, and you cannot easily modify a media file in all projects.

If I were you I would probably choose the first or third solution (symbolic links or submodules). If you choose to use submodules you can still do a lot of things to make your life easier:

  1. Before committing you can rename the submodule directory and put a symlink to a common media directory. When you're ready to commit, you can remove the symlink and remove the submodule back, and then commit.

  2. You can add one of your copy of the media repository as a remote repository to all of your projects.

You can add local directories as a remote this way:

cd /my/project2/media
git remote add project1 /my/project1/media

If you modify a file in /my/project1/media, you can commit it and pull it from /my/project2/media without pushing it to a remote server:

cd /my/project1/media
git commit -a -m "message"
cd /my/project2/media
git pull project1 master

You are free to remove these commits later (with git reset) because you haven't shared them with other users.

How do I restrict an input to only accept numbers?

Basic HTML

<input type="number" />

Basic bootstrap

<input class="form-control" type="number" value="42" id="my-id">

AngularJS: Insert HTML from a string

you can also use $sce.trustAsHtml('"<h1>" + str + "</h1>"'),if you want to know more detail, please refer to $sce

How to remove time portion of date in C# in DateTime object only?

Try this, if you use a DateTimeOffset, it will also take care of the timezone

date1 = date1.LocalDateTime.Date;

If you need to add hours, use this:

date1 = date1.LocalDateTime.Date;
date1 = date1.AddHours(23).AddMinutes(59).AddSeconds(59);

UIBarButtonItem in navigation bar programmatically?

func viewDidLoad(){
let homeBtn: UIButton = UIButton(type: UIButtonType.custom)

        homeBtn.setImage(UIImage(named: "Home.png"), for: [])

        homeBtn.addTarget(self, action: #selector(homeAction), for: UIControlEvents.touchUpInside)

        homeBtn.frame = CGRect(x: 0, y: 0, width: 30, height: 30)

        let homeButton = UIBarButtonItem(customView: homeBtn)


        let backBtn: UIButton = UIButton(type: UIButtonType.custom)

        backBtn.setImage(UIImage(named: "back.png"), for: [])

        backBtn.addTarget(self, action: #selector(backAction), for: UIControlEvents.touchUpInside)

        backBtn.frame = CGRect(x: -10, y: 0, width: 30, height: 30)

        let backButton = UIBarButtonItem(customView: backBtn)
        self.navigationItem.setLeftBarButtonItems([backButton,homeButton], animated: true)
}

}

Android saving file to external storage

Use this function to save your bitmap in SD card

private void SaveImage(Bitmap finalBitmap) {

    String root = Environment.getExternalStorageDirectory().toString();
    File myDir = new File(root + "/saved_images");    
     if (!myDir.exists()) {
                    myDir.mkdirs();
                }
    Random generator = new Random();
    int n = 10000;
    n = generator.nextInt(n);
    String fname = "Image-"+ n +".jpg";
    File file = new File (myDir, fname);
    if (file.exists ())
      file.delete (); 
    try {
        FileOutputStream out = new FileOutputStream(file);
        finalBitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
        out.flush();
        out.close();

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

and add this in manifest

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 

EDIT: By using this line you will be able to see saved images in the gallery view.

sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED,
                         Uri.parse("file://" + Environment.getExternalStorageDirectory())));

look at this link also http://rajareddypolam.wordpress.com/?p=3&preview=true

Facebook Post Link Image

The easiest way is just a link tag:

<link rel="image_src" href="http://stackoverflow.com/images/logo.gif" />

But there are some other things you can add to your site to make it more Social media friendly:

Open Graph Tags

Open Graph tags are tags that you add to the <head> of your website to describe the entity your page represents, whether it is a band, restaurant, blog, or something else.

An Open Graph tag looks like this:

<meta property="og:tag name" content="tag value"/> 

If you use Open Graph tags, the following six are required:

  • og:title - The title of the entity.
  • og:type - The type of entity. You must select a type from the list of Open Graph types.
  • og:image - The URL to an image that represents the entity. Images must be at least 50 pixels by 50 pixels. Square images work best, but you are allowed to use images up to three times as wide as they are tall.
  • og:url - The canonical, permanent URL of the page representing the entity. When you use Open Graph tags, the Like button posts a link to the og:url instead of the URL in the Like button code.
  • og:site_name - A human-readable name for your site, e.g., "IMDb".
  • fb:admins or fb:app_id - A comma-separated list of either the Facebook IDs of page administrators or a Facebook Platform application ID. At a minimum, include only your own Facebook ID.

More information on Open Graph tags and details on Administering your page can be found on the Open Graph protocol documentation.

http://developers.facebook.com/docs/reference/plugins/like

Is it possible to use JavaScript to change the meta-tags of the page?

You can use more simpler and lighter solution:

document.head.querySelector('meta[name="description"]').content = _desc

ValueError: setting an array element with a sequence

The Python ValueError:

ValueError: setting an array element with a sequence.

Means exactly what it says, you're trying to cram a sequence of numbers into a single number slot. It can be thrown under various circumstances.

1. When you pass a python tuple or list to be interpreted as a numpy array element:

import numpy

numpy.array([1,2,3])               #good

numpy.array([1, (2,3)])            #Fail, can't convert a tuple into a numpy 
                                   #array element


numpy.mean([5,(6+7)])              #good

numpy.mean([5,tuple(range(2))])    #Fail, can't convert a tuple into a numpy 
                                   #array element


def foo():
    return 3
numpy.array([2, foo()])            #good


def foo():
    return [3,4]
numpy.array([2, foo()])            #Fail, can't convert a list into a numpy 
                                   #array element

2. By trying to cram a numpy array length > 1 into a numpy array element:

x = np.array([1,2,3])
x[0] = np.array([4])         #good



x = np.array([1,2,3])
x[0] = np.array([4,5])       #Fail, can't convert the numpy array to fit 
                             #into a numpy array element

A numpy array is being created, and numpy doesn't know how to cram multivalued tuples or arrays into single element slots. It expects whatever you give it to evaluate to a single number, if it doesn't, Numpy responds that it doesn't know how to set an array element with a sequence.

Border around specific rows in a table?

Thank you to all that have responded! I've tried all of the solutions presented here and I've done more searching on the internet for other possible solutions, and I think I've found one that's promising:

_x000D_
_x000D_
tr.top td {_x000D_
  border-top: thin solid black;_x000D_
}_x000D_
_x000D_
tr.bottom td {_x000D_
  border-bottom: thin solid black;_x000D_
}_x000D_
_x000D_
tr.row td:first-child {_x000D_
  border-left: thin solid black;_x000D_
}_x000D_
_x000D_
tr.row td:last-child {_x000D_
  border-right: thin solid black;_x000D_
}
_x000D_
<html>_x000D_
_x000D_
<head>_x000D_
</head>_x000D_
_x000D_
<body>_x000D_
_x000D_
  <table cellspacing="0">_x000D_
    <tr>_x000D_
      <td>no border</td>_x000D_
      <td>no border here either</td>_x000D_
    </tr>_x000D_
    <tr class="top row">_x000D_
      <td>one</td>_x000D_
      <td>two</td>_x000D_
    </tr>_x000D_
    <tr class="bottom row">_x000D_
      <td>three</td>_x000D_
      <td>four</td>_x000D_
    </tr>_x000D_
    <tr>_x000D_
      <td colspan="2">once again no borders</td>_x000D_
    </tr>_x000D_
    <tr class="top bottom row">_x000D_
      <td colspan="2">hello</td>_x000D_
    </tr>_x000D_
    <tr>_x000D_
      <td colspan="2">world</td>_x000D_
    </tr>_x000D_
  </table>_x000D_
_x000D_
</body>_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_

Output:

enter image description here

Instead of having to add the top, bottom, left, and right classes to every <td>, all I have to do is add top row to the top <tr>, bottom row to the bottom <tr>, and row to every <tr> in between. Is there anything wrong with this solution? Are there any cross-platform issues I should be aware of?

Find Facebook user (url to profile page) by known email address

The definitive answer to this is from Facebook themselves. In post today at https://developers.facebook.com/bugs/335452696581712 a Facebook dev says

The ability to pass in an e-mail address into the "user" search type was
removed on July 10, 2013. This search type only returns results that match
a user's name (including alternate name).

So, alas, the simple answer is you can no longer search for users by their email address. This sucks, but that's Facebook's new rules.

How to undo "git commit --amend" done instead of "git commit"

You can always split a commit, From the manual

  • Start an interactive rebase with git rebase -i commit^, where commit is the commit you want to split. In fact, any commit range will do, as long as it contains that commit.
  • Mark the commit you want to split with the action "edit".
  • When it comes to editing that commit, execute git reset HEAD^. The effect is that the HEAD is rewound by one, and the index follows suit. However, the working tree stays the same.
  • Now add the changes to the index that you want to have in the first commit. You can use git add (possibly interactively) or git-gui (or both) to do that.
  • Commit the now-current index with whatever commit message is appropriate now.
  • Repeat the last two steps until your working tree is clean.
  • Continue the rebase with git rebase --continue.

How do I remove time part from JavaScript date?

This is probably the easiest way:

new Date(<your-date-object>.toDateString());

Example: To get the Current Date without time component:

new Date(new Date().toDateString());

gives: Thu Jul 11 2019 00:00:00 GMT-0400 (Eastern Daylight Time)

Note this works universally, because toDateString() produces date string with your browser's localization (without the time component), and the new Date() uses the same localization to parse that date string.

Elegant way to report missing values in a data.frame

Another graphical and interactive way is to use is.na10 function from heatmaply library:

library(heatmaply)

heatmaply(is.na10(airquality), grid_gap = 1, 
          showticklabels = c(T,F),
            k_col =3, k_row = 3,
            margins = c(55, 30), 
            colors = c("grey80", "grey20"))

enter image description here

Probably won't work well with large datasets..

Why not use tables for layout in HTML?

  • 508 Compliance - the ability for a screenreader to make sense of your markup.
  • Waiting for render - tables don't render in the browser until it gets to the end of the </table> element.

Create an ArrayList with multiple object types?

It depends on the use case. Can you, please, describe it more?

  • If you want to be able to add both at one time, than you can do the which is nicely described by @Sanket Parikh. Put Integer and String into a new class and use that.

  • If you want to add the list either a String or an int, but only one of these at a time, then sure it is the List<Object>

    which looks good but only for first sight! This is not a good pattern. You'll have to check what type of object you have each time you get an object from your list. Also This type of list can contain any other types as well.. So no, not a nice solution. Although maybe for a beginner it can be used. If you choose this, i would recommend to check what is "instanceof" in Java.

  • I would strongly advise to reconsider your needs and think about maybe your real nead is to encapsulate Integers to a List<Integer> and Strings to a separate List<String>

Can i tell you a metaphor for what you want to do now? I would say you want to make a List wich can contain coffee beans and coffee shops. These to type of objects are totally different! Why are these put onto the same shelf? :)

Or do you have maybe data which can be a word or a number? Yepp! This would make sense, both of them is data! Then try to use one object for that which contains the data as String and if needed, can be translated to integer value.

public class MyDataObj {
String info;
boolean isNumeric;

public MyDataObj(String info){
    setInfo(info);
}

public MyDataObj(Integer info){
    setInfo(info);
}

public String getInfo() {
    return info;
}

public void setInfo(String info) {
    this.info = info;
    this.isNumeric = false;
}

public void setInfo(Integer info) {
    this.info = Integer.toString(info);
    this.isNumeric = true;
}

public boolean isNumeric() {
    return isNumeric;
}
}

This way you can use List<MyDataObj> for your needs. Again, this depends on your needs! :)

Some edition: What about using inharitance? This is better then then List<Object> solution, because you can not have other types in the list then Strings or Integers: Interface:

public interface IMyDataObj {
public String getInfo();
}

For String:

public class MyStringDataObj implements IMyDataObj {

final String info;

public MyStringDataObj(String info){
    this.info = info;
}

@Override
public String getInfo() {
    return info;
}
}

For Integer:

public class MyIntegerDataObj implements IMyDataObj {

final Integer info;

public MyIntegerDataObj(Integer info) {
    this.info = info;
}

@Override
public String getInfo() {
    return Integer.toString(info);
}
}

Finally the list will be: List<IMyDataObj>

Align labels in form next to input

You can do something like this:

HTML:

<div class='div'>
<label>Something</label>
<input type='text' class='input'/>
<div>

CSS:

.div{
      margin-bottom: 10px;
      display: grid;
      grid-template-columns: 1fr 4fr;
}

.input{
       width: 50%;
}

Hope this helps ! :)

Using Case/Switch and GetType to determine the object

You can do this:

if (node is CasusNodeDTO)
{
    ...
}
else if (node is BucketNodeDTO)
{
    ...
}
...

While that would be more elegant, it's possibly not as efficient as some of the other answers here.

Display loading image while post with ajax

This is very simple and easily manage.

jQuery(document).ready(function(){
jQuery("#search").click(function(){
    jQuery("#loader").show("slow");
    jQuery("#response_result").hide("slow");
    jQuery.post(siteurl+"/ajax.php?q="passyourdata, function(response){
        setTimeout("finishAjax('response_result', '"+escape(response)+"')", 850);
            });
});

})
function finishAjax(id,response){ 
      jQuery("#loader").hide("slow");   
      jQuery('#response_result').html(unescape(response));
      jQuery("#"+id).show("slow");      
      return true;
}

How to get the date and time values in a C program?

I was using command line C-compiler to compile these and it completely drove me bonkers as it refused to compile.

For some reason my compiler hated that I was declaring and using the function all in one line.

struct tm tm = *localtime(&t);

test.c
test.c(494) : error C2143: syntax error : missing ';' before 'type'
Compiler Status: 512

First declare your variable and then call the function. This is how I did it.

char   todayDateStr[100];
time_t rawtime;
struct tm *timeinfo;

time ( &rawtime );
timeinfo = localtime ( &rawtime );
strftime(todayDateStr, strlen("DD-MMM-YYYY HH:MM")+1,"%d-%b-%Y %H:%M",timeinfo);
printf("todayDateStr = %s ... \n", todayDateStr );

Iterate through <select> options

You can try like this too.

Your HTML Code

<select id="mySelectionBox">
    <option value="hello">Foo</option>
    <option value="hello1">Foo1</option>
    <option value="hello2">Foo2</option>
    <option value="hello3">Foo3</option>
</select>

You JQuery Code

$("#mySelectionBox option").each(function() {
    alert(this.text + ' ' + this.value);
});

OR

var select =  $('#mySelectionBox')[0];

  for (var i = 0; i < select.length; i++){
    var option = select.options[i];
    alert (option.text + ' ' + option.value);
  }

How to break out of multiple loops?

An easy way to turn multiple loops into a single, breakable loop is to use numpy.ndindex

for i in range(n):
  for j in range(n):
    val = x[i, j]
    break # still inside the outer loop!

for i, j in np.ndindex(n, n):
  val = x[i, j]
  break # you left the only loop there was!

You do have to index into your objects, as opposed to being able to iterate through the values explicitly, but at least in simple cases it seems to be approximately 2-20 times simpler than most of the answers suggested.

How link to any local file with markdown syntax?

This is a old question, but to me it still doesn't seem to have a complete answer to the OP's question. The chosen answer about security being the possible issue is actually often not the problem when using the Firefox 'Markdown Viewer' plug-in in my experience. Also, the OP seems to be using MS-Windows, so there is the added issue of specifying different drives.

So, here is a little more complete yet simple answer for the 'Markdown Viewer' plug-in on Windows (and other Markdown renderers I've seen): just enter the local path as you would normally, and if it is an absolute path make sure to start it with a slash. So:

[a relative link](../../some/dir/filename.md)
[Link to file in another dir on same drive](/another/dir/filename.md)
[Link to file in another dir on a different drive](/D:/dir/filename.md)

That last one was probably what the OP was looking for given their example. Note this can also be used to display directories rather than files.

Though late, I hope this helps!

EnterKey to press button in VBA Userform

Use the TextBox's Exit event handler:

Private Sub TextBox1_Exit(ByVal Cancel As MSForms.ReturnBoolean)
    Logincode_Click  
End Sub

Ruby: How to iterate over a range, but in set increments?

Here's another, perhaps more familiar-looking way to do it:

for i in (0..10).step(2) do
    puts i
end

Node Express sending image files as API response

a proper solution with streams and error handling is below:

const fs = require('fs')
const stream = require('stream')

app.get('/report/:chart_id/:user_id',(req, res) => {
  const r = fs.createReadStream('path to file') // or any other way to get a readable stream
  const ps = new stream.PassThrough() // <---- this makes a trick with stream error handling
  stream.pipeline(
   r,
   ps, // <---- this makes a trick with stream error handling
   (err) => {
    if (err) {
      console.log(err) // No such file or any other kind of error
      return res.sendStatus(400); 
    }
  })
  ps.pipe(res) // <---- this makes a trick with stream error handling
})

with Node older then 10 you will need to use pump instead of pipeline.

This API project is not authorized to use this API. Please ensure that this API is activated in the APIs Console

Sending a get request with axios from a webpage, I needed (finally) to enable also Geocoding API.

I also have Places API, Maps Javascript API, and Geolocation API.

Thanks to these guys

How to access the php.ini file in godaddy shared hosting linux

I found a guide to reload the php5.ini file or load a new one right away. You will need to access your Godaddy hosting panel where you will find the option "system process" do a restart there and it will load the php5.ini or php.ini file right away.

2 external guides to assist you:

http://support.godaddy.com/help/article/5980/managing-system-processes-on-linux-hosting-accounts

http://www.studio-owens.com/blog/GoDaddy-and-Your-php-ini-File.htm

How to make space between LinearLayout children?

Since API Level 14 you can just add a (transparent) divider drawable:

android:divider="@drawable/divider"
android:showDividers="middle"

and it will handle the rest for you!

BasicHttpBinding vs WsHttpBinding vs WebHttpBinding

You're comparing apples to oranges here:

  • webHttpBinding is the REST-style binding, where you basically just hit a URL and get back a truckload of XML or JSON from the web service

  • basicHttpBinding and wsHttpBinding are two SOAP-based bindings which is quite different from REST. SOAP has the advantage of having WSDL and XSD to describe the service, its methods, and the data being passed around in great detail (REST doesn't have anything like that - yet). On the other hand, you can't just browse to a wsHttpBinding endpoint with your browser and look at XML - you have to use a SOAP client, e.g. the WcfTestClient or your own app.

So your first decision must be: REST vs. SOAP (or you can expose both types of endpoints from your service - that's possible, too).

Then, between basicHttpBinding and wsHttpBinding, there differences are as follows:

  • basicHttpBinding is the very basic binding - SOAP 1.1, not much in terms of security, not much else in terms of features - but compatible to just about any SOAP client out there --> great for interoperability, weak on features and security

  • wsHttpBinding is the full-blown binding, which supports a ton of WS-* features and standards - it has lots more security features, you can use sessionful connections, you can use reliable messaging, you can use transactional control - just a lot more stuff, but wsHttpBinding is also a lot *heavier" and adds a lot of overhead to your messages as they travel across the network

For an in-depth comparison (including a table and code examples) between the two check out this codeproject article: Differences between BasicHttpBinding and WsHttpBinding

What does the "@" symbol do in SQL?

Its a parameter the you need to define. to prevent SQL Injection you should pass all your variables in as parameters.

How can I read command line parameters from an R script?

I just put together a nice data structure and chain of processing to generate this switching behaviour, no libraries needed. I'm sure it will have been implemented numerous times over, and came across this thread looking for examples - thought I'd chip in.

I didn't even particularly need flags (the only flag here is a debug mode, creating a variable which I check for as a condition of starting a downstream function if (!exists(debug.mode)) {...} else {print(variables)}). The flag checking lapply statements below produce the same as:

if ("--debug" %in% args) debug.mode <- T
if ("-h" %in% args || "--help" %in% args) 

where args is the variable read in from command line arguments (a character vector, equivalent to c('--debug','--help') when you supply these on for instance)

It's reusable for any other flag and you avoid all the repetition, and no libraries so no dependencies:

args <- commandArgs(TRUE)

flag.details <- list(
"debug" = list(
  def = "Print variables rather than executing function XYZ...",
  flag = "--debug",
  output = "debug.mode <- T"),
"help" = list(
  def = "Display flag definitions",
  flag = c("-h","--help"),
  output = "cat(help.prompt)") )

flag.conditions <- lapply(flag.details, function(x) {
  paste0(paste0('"',x$flag,'"'), sep = " %in% args", collapse = " || ")
})
flag.truth.table <- unlist(lapply(flag.conditions, function(x) {
  if (eval(parse(text = x))) {
    return(T)
  } else return(F)
}))

help.prompts <- lapply(names(flag.truth.table), function(x){
# joins 2-space-separatated flags with a tab-space to the flag description
  paste0(c(paste0(flag.details[x][[1]][['flag']], collapse="  "),
  flag.details[x][[1]][['def']]), collapse="\t")
} )

help.prompt <- paste(c(unlist(help.prompts),''),collapse="\n\n")

# The following lines handle the flags, running the corresponding 'output' entry in flag.details for any supplied
flag.output <- unlist(lapply(names(flag.truth.table), function(x){
  if (flag.truth.table[x]) return(flag.details[x][[1]][['output']])
}))
eval(parse(text = flag.output))

Note that in flag.details here the commands are stored as strings, then evaluated with eval(parse(text = '...')). Optparse is obviously desirable for any serious script, but minimal-functionality code is good too sometimes.

Sample output:

$ Rscript check_mail.Rscript --help
--debug Print  variables rather than executing function XYZ...

-h  --help  Display flag definitions

Bootstrap: How to center align content inside column?

You can do this by adding a div i.e. centerBlock. And give this property in CSS to center the image or any content. Here is the code:

<div class="container">
    <div class="row">
        <div class="col-sm-4 col-md-4 col-lg-4">
            <div class="centerBlock">
                <img class="img-responsive" src="img/some-image.png" title="This image needs to be centered">
            </div>
        </div>
        <div class="col-sm-8 col-md-8 col-lg-8">
            Some content not important at this moment
        </div>
    </div>
</div>


// CSS

.centerBlock {
  display: table;
  margin: auto;
}

How to generate auto increment field in select query

If it is MySql you can try

SELECT @n := @n + 1 n,
       first_name, 
       last_name
  FROM table1, (SELECT @n := 0) m
 ORDER BY first_name, last_name

SQLFiddle

And for SQLServer

SELECT row_number() OVER (ORDER BY first_name, last_name) n,
       first_name, 
       last_name 
  FROM table1 

SQLFiddle

node.js http 'get' request with query string parameters

If you ever need to send GET request to an IP as well as a Domain (Other answers did not mention you can specify a port variable), you can make use of this function:

function getCode(host, port, path, queryString) {
    console.log("(" + host + ":" + port + path + ")" + "Running httpHelper.getCode()")

    // Construct url and query string
    const requestUrl = url.parse(url.format({
        protocol: 'http',
        hostname: host,
        pathname: path,
        port: port,
        query: queryString
    }));

    console.log("(" + host + path + ")" + "Sending GET request")
    // Send request
    console.log(url.format(requestUrl))
    http.get(url.format(requestUrl), (resp) => {
        let data = '';

        // A chunk of data has been received.
        resp.on('data', (chunk) => {
            console.log("GET chunk: " + chunk);
            data += chunk;
        });

        // The whole response has been received. Print out the result.
        resp.on('end', () => {
            console.log("GET end of response: " + data);
        });

    }).on("error", (err) => {
        console.log("GET Error: " + err);
    });
}

Don't miss requiring modules at the top of your file:

http = require("http");
url = require('url')

Also bare in mind that you may use https module for communicating over secured network.

Disable single warning error

If you want to disable unreferenced local variable write in some header

template<class T>
void ignore (const T & ) {}

and use

catch(const Except & excpt) {
    ignore(excpt); // No warning
    // ...  
} 

Difference between map and collect in Ruby?

Ruby aliases the method Array#map to Array#collect; they can be used interchangeably. (Ruby Monk)

In other words, same source code :

               static VALUE
rb_ary_collect(VALUE ary)
{
long i;
VALUE collect;

RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
collect = rb_ary_new2(RARRAY_LEN(ary));
for (i = 0; i < RARRAY_LEN(ary); i++) {
    rb_ary_push(collect, rb_yield(RARRAY_AREF(ary, i)));
}
return collect;
}

http://ruby-doc.org/core-2.2.0/Array.html#method-i-map

Can you get a Windows (AD) username in PHP?

get_user_name works the same way as getenv('USERNAME');

I had encoding(with cyrillic) problems using getenv('USERNAME')

Cygwin Make bash command not found

when selecting packages at installation or update search for 'make' in searchbox and select the boxes showing 'make' and also 'gcc' mostly found in devel package.

What is the most compatible way to install python modules on a Mac?

I use easy_install with Apple's Python, and it works like a charm.

JQuery .each() backwards

I think u need

.parentsUntill()

Angular 2 'component' is not a known element

These are the 5 steps I perform when I got such an error.

  • Are you sure the name is correct? (also check the selector defined in the component)
  • Declare the component in a module?
  • If it is in another module, export the component?
  • If it is in another module, import that module?
  • Restart the cli?

When the error eccors during unit testing, make sure your declared the component or imported the module in TestBed.configureTestingModule

I also tried putting ContactBoxComponent in CustomersAddComponent and then in another one (from different module) but I got an error saying there are multiple declarations.

You can't declare a component twice. You should declare and export your component in a new separate module. Next you should import this new module in every module you want to use your component.

It is hard to tell when you should create new module and when you shouldn't. I usually create a new module for every component I reuse. When I have some components that I use almost everywhere I put them in a single module. When I have a component that I don't reuse I won't create a separate module until I need it somewhere else.

Though it might be tempting to put all you components in a single module, this is bad for the performance. While developing, a module has to recompile every time changes are made. The bigger the module (more components) the more time it takes. Making a small change to big module takes more time than making a small change in a small module.

Python logging not outputting anything

Many years later there seems to still be a usability problem with the Python logger. Here's some explanations with examples:

import logging
# This sets the root logger to write to stdout (your console).
# Your script/app needs to call this somewhere at least once.
logging.basicConfig()

# By default the root logger is set to WARNING and all loggers you define
# inherit that value. Here we set the root logger to NOTSET. This logging
# level is automatically inherited by all existing and new sub-loggers
# that do not set a less verbose level.
logging.root.setLevel(logging.NOTSET)

# The following line sets the root logger level as well.
# It's equivalent to both previous statements combined:
logging.basicConfig(level=logging.NOTSET)


# You can either share the `logger` object between all your files or the
# name handle (here `my-app`) and call `logging.getLogger` with it.
# The result is the same.
handle = "my-app"
logger1 = logging.getLogger(handle)
logger2 = logging.getLogger(handle)
# logger1 and logger2 point to the same object:
# (logger1 is logger2) == True


# Convenient methods in order of verbosity from highest to lowest
logger.debug("this will get printed")
logger.info("this will get printed")
logger.warning("this will get printed")
logger.error("this will get printed")
logger.critical("this will get printed")


# In large applications where you would like more control over the logging,
# create sub-loggers from your main application logger.
component_logger = logger.getChild("component-a")
component_logger.info("this will get printed with the prefix `my-app.component-a`")

# If you wish to control the logging levels, you can set the level anywhere 
# in the hierarchy:
#
# - root
#   - my-app
#     - component-a
#

# Example for development:
logger.setLevel(logging.DEBUG)

# If that prints too much, enable debug printing only for your component:
component_logger.setLevel(logging.DEBUG)


# For production you rather want:
logger.setLevel(logging.WARNING)

A common source of confusion comes from a badly initialised root logger. Consider this:

import logging
log = logging.getLogger("myapp")
log.warning("woot")
logging.basicConfig()
log.warning("woot")

Output:

woot
WARNING:myapp:woot

Depending on your runtime environment and logging levels, the first log line (before basic config) might not show up anywhere.

How npm start runs a server on port 8000

We have a react application and our development machines are both mac and pc. The start command doesn't work for PC so here is how we got around it:

"start": "PORT=3001 react-scripts start",
"start-pc": "set PORT=3001&& react-scripts start",

On my mac:

npm start

On my pc:

 npm run start-pc

how to copy only the columns in a DataTable to another DataTable?

If only the columns are required then DataTable.Clone() can be used. With Clone function only the schema will be copied. But DataTable.Copy() copies both the structure and data

E.g.

DataTable dt = new DataTable();
dt.Columns.Add("Column Name");
dt.Rows.Add("Column Data");
DataTable dt1 = dt.Clone();
DataTable dt2 = dt.Copy();

dt1 will have only the one column but dt2 will have one column with one row.

php codeigniter count rows

This is what is did that solved the same problem. I solved it by creating a function that returns the query result thus:

function getUsers(){
$query = $this->db->get('users');
return $query->result();
}

//The above code can go in the user_model or whatever your model is.

This allows me to use one function for the result and number of returned rows.

Use this code below in your contoller where you need the count as well as the result array().

//This gives you the user count using the count function which returns and integer of the exact rows returned from the query.
$this->data['user_count'] = count($this->user_model->getUsers());

//This gives you the returned result array.
$this->data['users'] = $this->user_model->getUsers();

I hope this helps.

System.Net.WebException HTTP status code

By using the null-conditional operator (?.) you can get the HTTP status code with a single line of code:

 HttpStatusCode? status = (ex.Response as HttpWebResponse)?.StatusCode;

The variable status will contain the HttpStatusCode. When the there is a more general failure like a network error where no HTTP status code is ever sent then status will be null. In that case you can inspect ex.Status to get the WebExceptionStatus.

If you just want a descriptive string to log in case of a failure you can use the null-coalescing operator (??) to get the relevant error:

string status = (ex.Response as HttpWebResponse)?.StatusCode.ToString()
    ?? ex.Status.ToString();

If the exception is thrown as a result of a 404 HTTP status code the string will contain "NotFound". On the other hand, if the server is offline the string will contain "ConnectFailure" and so on.

(And for anybody that wants to know how to get the HTTP substatus code. That is not possible. It is a Microsoft IIS concept that is only logged on the server and never sent to the client.)

How do I tell what type of value is in a Perl variable?

At some point I read a reasonably convincing argument on Perlmonks that testing the type of a scalar with ref or reftype is a bad idea. I don't recall who put the idea forward, or the link. Sorry.

The point was that in Perl there are many mechanisms that make it possible to make a given scalar act like just about anything you want. If you tie a filehandle so that it acts like a hash, the testing with reftype will tell you that you have a filehanle. It won't tell you that you need to use it like a hash.

So, the argument went, it is better to use duck typing to find out what a variable is.

Instead of:

sub foo {
    my $var = shift;
    my $type = reftype $var;

    my $result;
    if( $type eq 'HASH' ) {
        $result = $var->{foo};
    }
    elsif( $type eq 'ARRAY' ) {
        $result = $var->[3];
    }
    else {
        $result = 'foo';
    }

    return $result;
}

You should do something like this:

sub foo {
    my $var = shift;
    my $type = reftype $var;

    my $result;

    eval {
        $result = $var->{foo};
        1; # guarantee a true result if code works.
    }
    or eval { 
        $result = $var->[3];
        1;
    }
    or do {
        $result = 'foo';
    }

    return $result;
}

For the most part I don't actually do this, but in some cases I have. I'm still making my mind up as to when this approach is appropriate. I thought I'd throw the concept out for further discussion. I'd love to see comments.

Update

I realized I should put forward my thoughts on this approach.

This method has the advantage of handling anything you throw at it.

It has the disadvantage of being cumbersome, and somewhat strange. Stumbling upon this in some code would make me issue a big fat 'WTF'.

I like the idea of testing whether a scalar acts like a hash-ref, rather that whether it is a hash ref.

I don't like this implementation.

Difference between Static methods and Instance methods

The static modifier when placed in front of a function implies that only one copy of that function exists. If the static modifier is not placed in front of the function then with every object or instance of that class a new copy of that function is made. :) Same is the case with variables.

Convert float to std::string in C++

You can use std::to_string in C++11

float val = 2.5;
std::string my_val = std::to_string(val);

SVN remains in conflict?

I use the following command in order to remove conflict using command line

svn revert "location of conflict folder" -R
svn cleanup
svn update

for reverting current directory

svn revert . -R

How do I call a non-static method from a static method in C#?

Apologized to post answer for very old thread but i believe my answer may help other.

With the help of delegate the same thing can be achieved.

public class MyClass
{
    private static Action NonStaticDelegate;

    public void NonStaticMethod()
    {
        Console.WriteLine("Non-Static!");
    }

    public static void CaptureDelegate()
    {
        MyClass temp = new MyClass();
        MyClass.NonStaticDelegate = new Action(temp.NonStaticMethod);
    }

    public static void RunNonStaticMethod()
    {
        if (MyClass.NonStaticDelegate != null)
        {
            // This will run the non-static method.
            //  Note that you still needed to create an instance beforehand
            MyClass.NonStaticDelegate();
        }
    }
}

How do I use regular expressions in bash scripts?

It was changed between 3.1 and 3.2:

This is a terse description of the new features added to bash-3.2 since the release of bash-3.1.

Quoting the string argument to the [[ command's =~ operator now forces string matching, as with the other pattern-matching operators.

So use it without the quotes thus:

i="test"
if [[ $i =~ 200[78] ]] ; then
    echo "OK"
else
    echo "not OK"
fi

How to convert an Object {} to an Array [] of key-value pairs in JavaScript

If you are using lodash, it could be as simple as this:

var arr = _.values(obj);

How to add "Maven Managed Dependencies" library in build path eclipse?

If you imported an existing maven project and Maven dependencies are not showing in the build path in eclipse then right click on project--> Maven--> 'update Project' will resolve the issue.

SVN (Subversion) Problem "File is scheduled for addition, but is missing" - Using Versions

This solved my similar problem. I used it to revert the changes, then I added everything and commited changes in the terminal with

svn add folder_path/*
svn commit -m "message"

Access-Control-Allow-Origin error sending a jQuery Post to Google API's

If you have this error trying to consume a service that you can't add the header Access-Control-Allow-Origin * in that application, but you can put in front of the server a reverse proxy, the error can avoided with a header rewrite.

Assuming the application is running on the port 8080 (public domain at www.mydomain.com), and you put the reverse proxy in the same host at port 80, this is the configuration for Nginx reverse proxy:

server {
    listen      80;
    server_name www.mydomain.com;
    access_log  /var/log/nginx/www.mydomain.com.access.log;
    error_log   /var/log/nginx/www.mydomain.com.error.log;

    location / {
        proxy_pass   http://127.0.0.1:8080;
        add_header   Access-Control-Allow-Origin *;
    }   
}

how to run mysql in ubuntu through terminal

If you want to run your scripts, then

mysql -u root -p < yourscript.sql

Setting a global PowerShell variable from a function where the global variable name is a variable passed to the function

You'll have to pass your arguments as reference types.

#First create the variables (note you have to set them to something)
$global:var1 = $null
$global:var2 = $null
$global:var3 = $null

#The type of the reference argument should be of type [REF]
function foo ($a, $b, [REF]$c)
{
    # add $a and $b and set the requested global variable to equal to it
    # Note how you modify the value.
    $c.Value = $a + $b
}

#You can then call it like this:
foo 1 2 [REF]$global:var3

Cannot create Maven Project in eclipse

I had the same error show up while creating the project but I wasn't behind a proxy and hence the above solutions did not work for me.

I found this forum. It suggested to:

  1. Delete or Rename .m2 directory from your HOME directory

In Windows - C:\Users\<username>\Windows

OR

In Linux - /home/<username>
  1. restart the Eclipse / STS spring tool suite (which am using)

It worked!

ffmpeg - Converting MOV files to MP4

The command to just stream it to a new container (mp4) needed by some applications like Adobe Premiere Pro without encoding (fast) is:

ffmpeg -i input.mov -qscale 0 output.mp4

Alternative as mentioned in the comments, which re-encodes with best quaility (-qscale 0):

ffmpeg -i input.mov -q:v 0 output.mp4

How to add SHA-1 to android application

when I generate sha1 key using android studio

Gradle -> Tasks -> android-> signingReport and double click

That sha1 key is worked in debug mode but not worked when i build singed APK

so I generated sha 1 key using cmd it work

  • go to java\jdk version\ bin folder

example

C:\>cd C:\Program Files\Java\jdk1.8.0_121\bin

and type

keytool -exportcert  -keystore {path of sign jks key } -list -v

example

keytool -exportcert  -keystore F:\testkey\damithk.jks -list -v

What does the "@" symbol do in Powershell?

The Splatting Operator

To create an array, we create a variable and assign the array. Arrays are noted by the "@" symbol. Let's take the discussion above and use an array to connect to multiple remote computers:

$strComputers = @("Server1", "Server2", "Server3")<enter>

They are used for arrays and hashes.

PowerShell Tutorial 7: Accumulate, Recall, and Modify Data

Array Literals In PowerShell

JPA: unidirectional many-to-one and cascading delete

Create a bi-directional relationship, like this:

@Entity
public class Parent implements Serializable {

    @Id
    @GeneratedValue
    private long id;

    @OneToMany(mappedBy = "parent", cascade = CascadeType.REMOVE)
    private Set<Child> children;
}

How to print multiple variable lines in Java

You can do it with 1 printf:

System.out.printf("First Name: %s\nLast Name: %s",firstname, lastname);

Access multiple elements of list knowing their index

Another solution could be via pandas Series:

import pandas as pd

a = pd.Series([-2, 1, 5, 3, 8, 5, 6])
b = [1, 2, 5]
c = a[b]

You can then convert c back to a list if you want:

c = list(c)

Python: TypeError: object of type 'NoneType' has no len()

What is the purpose of this

 names = list;

? Also, no ; required in Python.

Do you want

 names = []

or

 names = list()

at the start of your program instead? Though given your particular code, there's no need for this statement to create this names variable since you do so later when you read data into it from your file.

@JBernardo has already pointed out the other (and more major) problem with the code.

Using Javascript can you get the value from a session attribute set by servlet in the HTML page

<%
String session_val = (String)session.getAttribute("sessionval"); 
System.out.println("session_val"+session_val);
%>
<html>
<head>
<script type="text/javascript">
var session_obj= '<%=session_val%>';
alert("session_obj"+session_obj);
</script>
</head>
</html>

How to upload file using Selenium WebDriver in Java

First make sure that the input element is visible

As stated by Mark Collin in the discussion here:

Don't click on the browse button, it will trigger an OS level dialogue box and effectively stop your test dead.

Instead you can use:

driver.findElement(By.id("myUploadElement")).sendKeys("<absolutePathToMyFile>");

myUploadElement is the id of that element (button in this case) and in sendKeys you have to specify the absolute path of the content you want to upload (Image,video etc). Selenium will do the rest for you.

Keep in mind that the upload will work only If the element you send a file should be in the form <input type="file">

Increase max execution time for php

well, there are two way to change max_execution_time.
1. You can directly set it in php.ini file.
2. Secondly, you can add following line in your code.

ini_set('max_execution_time', '100')

Undefined symbols for architecture arm64

In my case using dlib in IOS, I need to delete "inherited" from build settings/preprocessor macros.

Storyboard - refer to ViewController in AppDelegate

    UIStoryboard * storyboard = [UIStoryboard storyboardWithName:@"Tutorial" bundle:nil];
    self.window.rootViewController = [storyboard instantiateInitialViewController];

SVG rounded corner

Here are some paths for tabs:

https://codepen.io/mochime/pen/VxxzMW

_x000D_
_x000D_
<!-- left tab -->_x000D_
<div>_x000D_
  <svg width="60" height="60">_x000D_
    <path d="M10,10 _x000D_
             a10 10 0 0 1 10 -10_x000D_
             h 50   _x000D_
             v 47_x000D_
             h -50_x000D_
             a10 10 0 0 1 -10 -10_x000D_
             z"_x000D_
      fill="#ff3600"></path>_x000D_
  </svg>_x000D_
</div>_x000D_
_x000D_
<!-- right tab -->_x000D_
<div>_x000D_
  <svg width="60" height="60">_x000D_
    <path d="M10 0   _x000D_
             h 40_x000D_
             a10 10 0 0 1 10 10_x000D_
             v 27_x000D_
             a10 10 0 0 1 -10 10_x000D_
             h -40_x000D_
             z"_x000D_
      fill="#ff3600"></path>_x000D_
  </svg>_x000D_
</div>_x000D_
_x000D_
<!-- tab tab :) -->_x000D_
<div>_x000D_
  <svg width="60" height="60">_x000D_
    <path d="M10,40 _x000D_
             v -30_x000D_
             a10 10 0 0 1 10 -10_x000D_
             h 30_x000D_
             a10 10 0 0 1 10 10_x000D_
             v 30_x000D_
             z"_x000D_
      fill="#ff3600"></path>_x000D_
  </svg>_x000D_
</div>
_x000D_
_x000D_
_x000D_

The other answers explained the mechanics. I especially liked hossein-maktoobian's answer.

The paths in the pen do the brunt of the work, the values can be modified to suite whatever desired dimensions.

Which mime type should I use for mp3

The standard way is to use audio/mpeg which is something like this in your PHP header function ...

header('Content-Type: audio/mpeg');

How do I use the built in password reset/change views with my own templates

You just need to wrap the existing functions and pass in the template you want. For example:

from django.contrib.auth.views import password_reset

def my_password_reset(request, template_name='path/to/my/template'):
    return password_reset(request, template_name)

To see this just have a look at the function declartion of the built in views:

http://code.djangoproject.com/browser/django/trunk/django/contrib/auth/views.py#L74

How do I get the coordinates of a mouse click on a canvas element?

I was creating an application having a canvas over a pdf, that involved a lot of resizes of canvas like Zooming the pdf-in and out, and in turn on every zoom-in/out of PDF I had to resize the canvas to adapt the size of the pdf, I went through lot of answers in stackOverflow, and didn't found a perfect solution that will eventually solve the problem.

I was using rxjs and angular 6, and didn't found any answer specific to the newest version.

Here is the entire code snippet that would be helpful, to anyone leveraging rxjs to draw on top of canvas.

  private captureEvents(canvasEl: HTMLCanvasElement) {

    this.drawingSubscription = fromEvent(canvasEl, 'mousedown')
      .pipe(
        switchMap((e: any) => {

          return fromEvent(canvasEl, 'mousemove')
            .pipe(
              takeUntil(fromEvent(canvasEl, 'mouseup').do((event: WheelEvent) => {
                const prevPos = {
                  x: null,
                  y: null
                };
              })),

              takeUntil(fromEvent(canvasEl, 'mouseleave')),
              pairwise()
            )
        })
      )
      .subscribe((res: [MouseEvent, MouseEvent]) => {
        const rect = this.cx.canvas.getBoundingClientRect();
        const prevPos = {
          x: Math.floor( ( res[0].clientX - rect.left ) / ( rect.right - rect.left ) * this.cx.canvas.width ),
          y:  Math.floor( ( res[0].clientY - rect.top ) / ( rect.bottom - rect.top ) * this.cx.canvas.height )
        };
        const currentPos = {
          x: Math.floor( ( res[1].clientX - rect.left ) / ( rect.right - rect.left ) * this.cx.canvas.width ),
          y: Math.floor( ( res[1].clientY - rect.top ) / ( rect.bottom - rect.top ) * this.cx.canvas.height )
        };

        this.coordinatesArray[this.file.current_slide - 1].push(prevPos);
        this.drawOnCanvas(prevPos, currentPos);
      });
  }

And here is the snippet that fixes, mouse coordinates relative to size of the canvas, irrespective of how you zoom-in/out the canvas.

const prevPos = {
  x: Math.floor( ( res[0].clientX - rect.left ) / ( rect.right - rect.left ) * this.cx.canvas.width ),
  y:  Math.floor( ( res[0].clientY - rect.top ) / ( rect.bottom - rect.top ) * this.cx.canvas.height )
};
const currentPos = {
  x: Math.floor( ( res[1].clientX - rect.left ) / ( rect.right - rect.left ) * this.cx.canvas.width ),
  y: Math.floor( ( res[1].clientY - rect.top ) / ( rect.bottom - rect.top ) * this.cx.canvas.height )
};

Refused to display 'url' in a frame because it set 'X-Frame-Options' to 'SAMEORIGIN'

I faced the same error when displaying YouTube links. For example: https://www.youtube.com/watch?v=8WkuChVeL0s

I replaced watch?v= with embed/ so the valid link will be: https://www.youtube.com/embed/8WkuChVeL0s

It works well.

Try to apply the same rule on your case.

Strtotime() doesn't work with dd/mm/YYYY format

I haven't found a better solution. You can use explode(), preg_match_all(), etc.

I have a static helper function like this

class Date {

    public static function ausStrToTime($str) {
        $dateTokens = explode('/', $str);
        return strtotime($dateTokens[1] . '/' . $dateTokens[0] . '/' . $dateTokens[2]); 

    }

}

There is probably a better name for that, but I use ausStrToTime() because it works with Australian dates (which I often deal with, being an Australian). A better name would probably be the standardised name, but I'm not sure what that is.

Can I assume (bool)true == (int)1 for any C++ compiler?

Charles Bailey's answer is correct. The exact wording from the C++ standard is (§4.7/4): "If the source type is bool, the value false is converted to zero and the value true is converted to one."

Edit: I see he's added the reference as well -- I'll delete this shortly, if I don't get distracted and forget...

Edit2: Then again, it is probably worth noting that while the Boolean values themselves always convert to zero or one, a number of functions (especially from the C standard library) return values that are "basically Boolean", but represented as ints that are normally only required to be zero to indicate false or non-zero to indicate true. For example, the is* functions in <ctype.h> only require zero or non-zero, not necessarily zero or one.

If you cast that to bool, zero will convert to false, and non-zero to true (as you'd expect).

possibly undefined macro: AC_MSG_ERROR

Are you setting up a local 'm4' directory? e.g.,

> aclocal -I m4 --install

Some packages come with an autogen.sh or initgen.sh shell script to run glibtoolize, autoheader, autoconf, automake. Here's an autogen.sh script I use:

#! /bin/sh

case `uname` in Darwin*) glibtoolize --copy ;;
  *) libtoolize --copy ;; esac

autoheader
aclocal -I m4 --install
autoconf

automake --foreign --add-missing --force-missing --copy

EDIT

You may need to add ACLOCAL_AMFLAGS = -I m4 to the top-level Makefile.am.

Proper use of 'yield return'

I know this is an old question, but I'd like to offer one example of how the yield keyword can be creatively used. I have really benefited from this technique. Hopefully this will be of assistance to anyone else who stumbles upon this question.

Note: Don't think about the yield keyword as merely being another way to build a collection. A big part of the power of yield comes in the fact that execution is paused in your method or property until the calling code iterates over the next value. Here's my example:

Using the yield keyword (alongside Rob Eisenburg's Caliburn.Micro coroutines implementation) allows me to express an asynchronous call to a web service like this:

public IEnumerable<IResult> HandleButtonClick() {
    yield return Show.Busy();

    var loginCall = new LoginResult(wsClient, Username, Password);
    yield return loginCall;
    this.IsLoggedIn = loginCall.Success;

    yield return Show.NotBusy();
}

What this will do is turn my BusyIndicator on, call the Login method on my web service, set my IsLoggedIn flag to the return value, and then turn the BusyIndicator back off.

Here's how this works: IResult has an Execute method and a Completed event. Caliburn.Micro grabs the IEnumerator from the call to HandleButtonClick() and passes it into a Coroutine.BeginExecute method. The BeginExecute method starts iterating through the IResults. When the first IResult is returned, execution is paused inside HandleButtonClick(), and BeginExecute() attaches an event handler to the Completed event and calls Execute(). IResult.Execute() can perform either a synchronous or an asynchronous task and fires the Completed event when it's done.

LoginResult looks something like this:

public LoginResult : IResult {
    // Constructor to set private members...

    public void Execute(ActionExecutionContext context) {
        wsClient.LoginCompleted += (sender, e) => {
            this.Success = e.Result;
            Completed(this, new ResultCompletionEventArgs());
        };
        wsClient.Login(username, password);
    }

    public event EventHandler<ResultCompletionEventArgs> Completed = delegate { };
    public bool Success { get; private set; }
}

It may help to set up something like this and step through the execution to watch what's going on.

Hope this helps someone out! I've really enjoyed exploring the different ways yield can be used.

How to include a font .ttf using CSS?

Did you try format?

@font-face {
  font-family: 'The name of the Font Family Here';
  src: URL('font.ttf') format('truetype');
}

Read this article: http://css-tricks.com/snippets/css/using-font-face/

Also, might depend on browser as well.

the getSource() and getActionCommand()

I use getActionCommand() to hear buttons. I apply the setActionCommand() to each button so that I can hear whenever an event is execute with event.getActionCommand("The setActionCommand() value of the button").

I use getSource() for JRadioButtons for example. I write methods that returns each JRadioButton so in my Listener Class I can specify an action each time a new JRadioButton is pressed. So for example:

public class SeleccionListener implements ActionListener, FocusListener {}

So with this I can hear button events and radioButtons events. The following are examples of how I listen each one:

public void actionPerformed(ActionEvent event) {
    if (event.getActionCommand().equals(GUISeleccion.BOTON_ACEPTAR)) {
        System.out.println("Aceptar pressed");
    }

In this case GUISeleccion.BOTON_ACEPTAR is a "public static final String" which is used in JButtonAceptar.setActionCommand(BOTON_ACEPTAR).

public void focusGained(FocusEvent focusEvent) {
    if (focusEvent.getSource().equals(guiSeleccion.getJrbDat())){
        System.out.println("Data radio button");
    }

In this one, I get the source of any JRadioButton that is focused when the user hits it. guiSeleccion.getJrbDat() returns the reference to the JRadioButton that is in the class GUISeleccion (this is a Frame)

C# - Fill a combo box with a DataTable

A few points:

1) "DataBind()" is only for web apps (not windows apps).

2) Your code looks very 'JAVAish' (not a bad thing, just an observation).

Try this:

mnuActionLanguage.ComboBox.DataSource = languages;

If that doesn't work... then I'm assuming that your datasource is being stepped on somewhere else in the code.

How to use stringstream to separate comma separated strings

#include <iostream>
#include <string>
#include <sstream>
using namespace std;
int main()
{
    std::string input = "abc,def,   ghi";
    std::istringstream ss(input);
    std::string token;
    size_t pos=-1;
    while(ss>>token) {
      while ((pos=token.rfind(',')) != std::string::npos) {
        token.erase(pos, 1);
      }
      std::cout << token << '\n';
    }
}

dropping rows from dataframe based on a "not in" condition

You can use Series.isin:

df = df[~df.datecolumn.isin(a)]

While the error message suggests that all() or any() can be used, they are useful only when you want to reduce the result into a single Boolean value. That is however not what you are trying to do now, which is to test the membership of every values in the Series against the external list, and keep the results intact (i.e., a Boolean Series which will then be used to slice the original DataFrame).

You can read more about this in the Gotchas.

How can I use a reportviewer control in an asp.net mvc 3 razor view?

the documentations refers to an ASP.NET application.
You can try and have a look at my answer here.
I have an example attached to my reply.
Another example for ASP.NET MVC3 can be found here.

SQL Server : export query as a .txt file

This is quite simple to do and the answer is available in other queries. For those of you who are viewing this:

select entries from my_entries where id='42' INTO OUTFILE 'bishwas.txt';

Check if any type of files exist in a directory using BATCH script

You can use this

@echo off
for /F %%i in ('dir /b "c:\test directory\*.*"') do (
   echo Folder is NON empty
   goto :EOF
)
echo Folder is empty or does not exist

Taken from here.

That should do what you need.

MySQLDump one INSERT statement for each data row

Use:

mysqldump --extended-insert=FALSE 

Be aware that multiple inserts will be slower than one big insert.

json_decode to array

This will also change it into an array:

<?php
    print_r((array) json_decode($object));
?>

REST API 404: Bad URI, or Missing Resource?

Use 404 if the resource does not exist. Don't return 200 with an empty body.

This is akin to undefined vs empty string (e.g. "") in programming. While very similar, there is definitely a difference.

404 means that nothing exists at that URI (like an undefined variable in programming). Returning 200 with an empty body means that something does exist there and that something is just empty right now (like an empty string in programming).

404 doesn't mean it was a "bad URI". There are special HTTP codes that are intended for URI errors (e.g. 414 Request-URI Too Long).

Basic calculator in Java

public class SwitchExample {

    public static void main(String[] args) throws Exception {
        System.out.println(":::::::::::::::::::::Start:::::::::::::::::::");
        System.out.println("\n\n");

        System.out.println("1. Addition");
        System.out.println("2. Multiplication");
        System.out.println("3. Substraction");
        System.out.println("4. Division");
        System.out.println("0. Exit");
        System.out.println("\n");

        System.out.println("Enter Your Choice :::::::  ");
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String str = br.readLine();

        int usrChoice = Integer.parseInt(str);

        switch (usrChoice) {
            case 1:
                doAddition();
                break;
            case 2:
                doMultiplication();
                break;
            case 3:
                doSubstraction();
                break;
            case 4:
                doDivision();
                break;

            case 0:
                System.out.println("Thank you.....");
                break;

            default:
                System.out.println("Invalid Value");
        }

        System.out.println(":::::::::::::::::::::End:::::::::::::::::::");
}

public static void doAddition() throws Exception {
    System.out.println("******* Enter in Addition Process ********");

    String strNo1, strNo2;

    System.out.println("Enter Number 1 For Addition : ");
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    strNo1 = br.readLine();

    System.out.println("Enter Number 2 For Addition : ");
    BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in));
    strNo2 = br1.readLine();

    int no1 = Integer.parseInt(strNo1);
    int no2 = Integer.parseInt(strNo2);

    int result = no1 + no2;

    System.out.println("Addition of " + no1 + " and " + no2 + " is ::::::: " + result);
}

public static void doSubstraction() throws Exception {
    System.out.println("******* Enter in Substraction Process ********");

    String strNo1, strNo2;

    System.out.println("Enter Number 1 For Substraction : ");
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    strNo1 = br.readLine();

    System.out.println("Enter Number 2 For Substraction : ");
    BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in));
    strNo2 = br1.readLine();

    int no1 = Integer.parseInt(strNo1);
    int no2 = Integer.parseInt(strNo2);

    int result = no1 - no2;

    System.out.println("Substraction of " + no1 + " and " + no2 + " is ::::::: " + result);
}

public static void doMultiplication() throws Exception {
    System.out.println("******* Enter in Multiplication Process ********");

    String strNo1, strNo2;

    System.out.println("Enter Number 1 For Multiplication : ");
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    strNo1 = br.readLine();

    System.out.println("Enter Number 2 For Multiplication : ");
    BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in));
    strNo2 = br1.readLine();

    int no1 = Integer.parseInt(strNo1);
    int no2 = Integer.parseInt(strNo2);

    int result = no1 * no2;

    System.out.println("Multiplication of " + no1 + " and " + no2 + " is ::::::: " + result);
}

public static void doDivision() throws Exception {
    System.out.println("******* Enter in Dividion Process ********");

    String strNo1, strNo2;

    System.out.println("Enter Number 1 For Dividion : ");
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    strNo1 = br.readLine();

    System.out.println("Enter Number 2 For Dividion : ");
    BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in));
    strNo2 = br1.readLine();

    int no1 = Integer.parseInt(strNo1);
    int no2 = Integer.parseInt(strNo2);

    float result = no1 / no2;

    System.out.println("Division of " + no1 + " and " + no2 + " is ::::::: " + result);
}

}

Authenticated HTTP proxy with Java

Most of the answer is in existing replies, but for me not quite. This is what works for me with java.net.HttpURLConnection (I have tested all the cases with JDK 7 and JDK 8). Note that you do not have to use the Authenticator class.

Case 1 : Proxy without user authentication, access HTTP resources

-Dhttp.proxyHost=myproxy -Dhttp.proxyPort=myport

Case 2 : Proxy with user authentication, access HTTP resources

-Dhttp.proxyHost=myproxy -Dhttp.proxyPort=myport -Dhttps.proxyUser=myuser -Dhttps.proxyPassword=mypass

Case 3 : Proxy without user authentication, access HTTPS resources (SSL)

-Dhttps.proxyHost=myproxy -Dhttps.proxyPort=myport 

Case 4 : Proxy with user authentication, access HTTPS resources (SSL)

-Dhttps.proxyHost=myproxy -Dhttps.proxyPort=myport -Dhttps.proxyUser=myuser -Dhttps.proxyPassword=mypass

Case 5 : Proxy without user authentication, access both HTTP and HTTPS resources (SSL)

-Dhttp.proxyHost=myproxy -Dhttp.proxyPort=myport -Dhttps.proxyHost=myproxy -Dhttps.proxyPort=myport 

Case 6 : Proxy with user authentication, access both HTTP and HTTPS resources (SSL)

-Dhttp.proxyHost=myproxy -Dhttp.proxyPort=myport -Dhttp.proxyUser=myuser -Dhttp.proxyPassword=mypass -Dhttps.proxyHost=myproxy -Dhttps.proxyPort=myport -Dhttps.proxyUser=myuser -Dhttps.proxyPassword=mypass

You can set the properties in the with System.setProperty("key", "value) too.

To access HTTPS resource you may have to trust the resource by downloading the server certificate and saving it in a trust store and then using that trust store. ie

 System.setProperty("javax.net.ssl.trustStore", "c:/temp/cert-factory/my-cacerts");
 System.setProperty("javax.net.ssl.trustStorePassword", "changeit");

How to list only top level directories in Python?

scanDir = "abc"
directories = [d for d in os.listdir(scanDir) if os.path.isdir(os.path.join(os.path.abspath(scanDir), d))]

Is log(n!) = T(n·log(n))?

This might help:

eln(x) = x

and

(lm)n = lm*n

String variable interpolation Java

Note that there is no variable interpolation in Java. Variable interpolation is variable substitution with its value inside a string. An example in Ruby:

#!/usr/bin/ruby

age = 34
name = "William"

puts "#{name} is #{age} years old"

The Ruby interpreter automatically replaces variables with its values inside a string. The fact, that we are going to do interpolation is hinted by sigil characters. In Ruby, it is #{}. In Perl, it could be $, % or @. Java would only print such characters, it would not expand them.

Variable interpolation is not supported in Java. Instead of this, we have string formatting.

package com.zetcode;

public class StringFormatting 
{
    public static void main(String[] args) 
    {
        int age = 34;
        String name = "William";

        String output = String.format("%s is %d years old.", name, age);
    
        System.out.println(output);
    }
}

In Java, we build a new string using the String.format() method. The outcome is the same, but the methods are different.

See http://en.wikipedia.org/wiki/Variable_interpolation

Edit As of 2019, JEP 326 (Raw String Literals) was withdrawn and superseded by multiple JEPs eventually leading to JEP 378: Text Blocks delivered in Java 15.

A text block is a multi-line string literal that avoids the need for most escape sequences, automatically formats the string in a predictable way, and gives the developer control over the format when desired.

However, still no string interpolation:

Non-Goals: … Text blocks do not directly support string interpolation. Interpolation may be considered in a future JEP. In the meantime, the new instance method String::formatted aids in situations where interpolation might be desired.

Fastest way to flatten / un-flatten nested JSON objects

ES6 version:

const flatten = (obj, path = '') => {        
    if (!(obj instanceof Object)) return {[path.replace(/\.$/g, '')]:obj};

    return Object.keys(obj).reduce((output, key) => {
        return obj instanceof Array ? 
             {...output, ...flatten(obj[key], path +  '[' + key + '].')}:
             {...output, ...flatten(obj[key], path + key + '.')};
    }, {});
}

Example:

console.log(flatten({a:[{b:["c","d"]}]}));
console.log(flatten([1,[2,[3,4],5],6]));

Cast Int to enum in Java

A good option is to avoid conversion from int to enum: for example, if you need the maximal value, you may compare x.ordinal() to y.ordinal() and return x or y correspondingly. (You may need to re-order you values to make such comparison meaningful.)

If that is not possible, I would store MyEnum.values() into a static array.

Open URL in same window and in same tab

Open another url like a click in link

window.location.href = "http://example.com";

Difference between return and exit in Bash functions

Remember, functions are internal to a script and normally return from whence they were called by using the return statement. Calling an external script is another matter entirely, and scripts usually terminate with an exit statement.

The difference "between the return and exit statement in Bash functions with respect to exit codes" is very small. Both return a status, not values per se. A status of zero indicates success, while any other status (1 to 255) indicates a failure. The return statement will return to the script from where it was called, while the exit statement will end the entire script from wherever it is encountered.

return 0  # Returns to where the function was called.  $? contains 0 (success).

return 1  # Returns to where the function was called.  $? contains 1 (failure).

exit 0  # Exits the script completely.  $? contains 0 (success).

exit 1  # Exits the script completely.  $? contains 1 (failure).

If your function simply ends without a return statement, the status of the last command executed is returned as the status code (and will be placed in $?).

Remember, return and exit give back a status code from 0 to 255, available in $?. You cannot stuff anything else into a status code (e.g., return "cat"); it will not work. But, a script can pass back 255 different reasons for failure by using status codes.

You can set variables contained in the calling script, or echo results in the function and use command substitution in the calling script; but the purpose of return and exit are to pass status codes, not values or computation results as one might expect in a programming language like C.

How to convert all text to lowercase in Vim

  1. If you really mean small caps, then no, that is not possible – just as it isn’t possible to convert text to bold or italic in any text editor (as opposed to word processor). If you want to convert text to lowercase, create a visual block and press u (or U to convert to uppercase). Tilde (~) in command mode reverses case of the character under the cursor.

  2. If you want to see all text in Vim in small caps, you might want to look at the guifont option, or type :set guifont=* if your Vim flavour supports GUI font chooser.

DateTime "null" value

I'd consider using a nullable types.

DateTime? myDate instead of DateTime myDate.

Pandas sum by groupby, but exclude certain columns

You can select the columns of a groupby:

In [11]: df.groupby(['Country', 'Item_Code'])[["Y1961", "Y1962", "Y1963"]].sum()
Out[11]:
                       Y1961  Y1962  Y1963
Country     Item_Code
Afghanistan 15            10     20     30
            25            10     20     30
Angola      15            30     40     50
            25            30     40     50

Note that the list passed must be a subset of the columns otherwise you'll see a KeyError.

What is a word boundary in regex, does \b match hyphen '-'?

Check out the documentation on boundary conditions:

http://java.sun.com/docs/books/tutorial/essential/regex/bounds.html

Check out this sample:

public static void main(final String[] args)
    {
        String x = "I found the value -12 in my string.";
        System.err.println(Arrays.toString(x.split("\\b-?\\d+\\b")));
    }

When you print it out, notice that the output is this:

[I found the value -, in my string.]

This means that the "-" character is not being picked up as being on the boundary of a word because it's not considered a word character. Looks like @brianary kinda beat me to the punch, so he gets an up-vote.

Responsive dropdown navbar with angular-ui bootstrap (done in the correct angular kind of way)

My solotion for responsive/dropdown navbar with angular-ui bootstrap (when update to angular 1.5 and, ui-bootrap 1.2.1)
index.html

     ...    
    <link rel="stylesheet" href="/css/app.css">
</head>
<body>


<nav class="navbar navbar-inverse navbar-fixed-top">
        <div class="container">
            <input type="checkbox" id="navbar-toggle-cbox">
            <div class="navbar-header">
                <label for="navbar-toggle-cbox" class="navbar-toggle" 
                       ng-init="navCollapsed = true" 
                       ng-click="navCollapsed = !navCollapsed"  
                       aria-controls="navbar">
                    <span class="sr-only">Toggle navigation</span>
                    <span class="icon-bar"></span>
                    <span class="icon-bar"></span>
                    <span class="icon-bar"></span>
                </label>
                <a class="navbar-brand" href="#">Project name</a>
                 <div id="navbar" class="collapse navbar-collapse"  ng-class="{'in':!navCollapsed}">
                    <ul class="nav navbar-nav">
                        <li class="active"><a href="/view1">Home</a></li>
                        <li><a href="/view2">About</a></li>
                        <li><a href="#">Contact</a></li>
                        <li uib-dropdown>
                            <a href="#" uib-dropdown-toggle>Dropdown <b class="caret"></b></a>
                            <ul uib-dropdown-menu role="menu" aria-labelledby="split-button">
                                <li role="menuitem"><a href="#">Action</a></li>
                                <li role="menuitem"><a href="#">Another action</a></li>                                   
                            </ul>
                        </li>

                    </ul>
                 </div>
            </div>
        </div>
    </nav>

app.css

/* show the collapse when navbar toggle is checked */
#navbar-toggle-cbox:checked ~ .collapse {
    display: block;
}

/* the checkbox used only internally; don't display it */
#navbar-toggle-cbox {
  display:none
}

Delete empty lines using sed

You can say:

sed -n '/ / p' filename    #there is a space between '//'

JBoss vs Tomcat again

I have also read that for some servers one for example needs only annotate persistence contexts, but in some servers, the injection should be done manually.

How to expand a list to function arguments in Python

Try the following:

foo(*values)

This can be found in the Python docs as Unpacking Argument Lists.

What's the difference between a single precision and double precision floating point operation?

I read a lot of answers but none seems to correctly explain where the word double comes from. I remember a very good explanation given by a University professor I had some years ago.

Recalling the style of VonC's answer, a single precision floating point representation uses a word of 32 bit.

  • 1 bit for the sign, S
  • 8 bits for the exponent, 'E'
  • 24 bits for the fraction, also called mantissa, or coefficient (even though just 23 are represented). Let's call it 'M' (for mantissa, I prefer this name as "fraction" can be misunderstood).

Representation:

          S  EEEEEEEE   MMMMMMMMMMMMMMMMMMMMMMM
bits:    31 30      23 22                     0

(Just to point out, the sign bit is the last, not the first.)

A double precision floating point representation uses a word of 64 bit.

  • 1 bit for the sign, S
  • 11 bits for the exponent, 'E'
  • 53 bits for the fraction / mantissa / coefficient (even though only 52 are represented), 'M'

Representation:

           S  EEEEEEEEEEE   MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
bits:     63 62         52 51                                                  0

As you may notice, I wrote that the mantissa has, in both types, one bit more of information compared to its representation. In fact, the mantissa is a number represented without all its non-significative 0. For example,

  • 0.000124 becomes 0.124 × 10-3
  • 237.141 becomes 0.237141 × 103

This means that the mantissa will always be in the form

0.a1a2...at × ßp

where ß is the base of representation. But since the fraction is a binary number, a1 will always be equal to 1, thus the fraction can be rewritten as 1.a2a3...at+1 × 2p and the initial 1 can be implicitly assumed, making room for an extra bit (at+1).

Now, it's obviously true that the double of 32 is 64, but that's not where the word comes from.

The precision indicates the number of decimal digits that are correct, i.e. without any kind of representation error or approximation. In other words, it indicates how many decimal digits one can safely use.

With that said, it's easy to estimate the number of decimal digits which can be safely used:

  • single precision: log10(224), which is about 7~8 decimal digits
  • double precision: log10(253), which is about 15~16 decimal digits

How to restart a windows service using Task Scheduler

Instead of using a bat file, you can simply create a Scheduled Task. Most of the time you define just one action. In this case, create two actions with the NET command. The first one to stop the service, the second one to start the service. Give them a STOP and START argument, followed by the service name.

In this example we restart the Printer Spooler service.

NET STOP "Print Spooler" 
NET START "Print Spooler"

enter image description here

enter image description here

Note: unfortunately NET RESTART <service name> does not exist.

Which terminal command to get just IP address and nothing else?

If you don't want to use ifconfig nor regex...

ip addr | grep eth0 | grep inet | awk '{print $2}' | cut -d"/" -f1

Wampserver icon not going green fully, mysql services not starting up?

Basically this happens when you have not installed pre required software installed on your machine while installing Wampserver you might have got error bellow error at the time of installation.

program can't start because msvcr120.dll is missing OR

program can't start because msvcr120.dll is missing

If you fixed those issue after the installation of wampserver then you might get stuck at this problem.

Then You can simply uninstall and install wamp server again

And If you have not install pre required dependency then first of all uninstall wampserver . And then install pre requirement first and then finally you can install Wampserver and it should work now.

you can download Pre-required applications from following link

For x64 Machines

microsoft visual c++ 2010 redistributable package (x64) https://www.microsoft.com/en-in/download/details.aspx?id=14632

Visual C++ Redistributable for Visual Studio 2012 Update 4 https://www.microsoft.com/en-in/download/details.aspx?id=30679

Visual C++ Redistributable Packages for Visual Studio 2013 https://www.microsoft.com/en-in/download/details.aspx?id=40784

Visual C++ Redistributable for Visual Studio 2015 https://www.microsoft.com/en-in/download/details.aspx?id=48145

For x86 Machines

Microsoft Visual C++ 2010 Redistributable Package (x86) https://www.microsoft.com/en-in/download/details.aspx?id=14632

Visual C++ Redistributable for Visual Studio 2012 Update 4 https://www.microsoft.com/en-in/download/details.aspx?id=30679

Visual C++ Redistributable Packages for Visual Studio 2013 https://www.microsoft.com/en-in/download/details.aspx?id=40784

Visual C++ Redistributable for Visual Studio 2015 https://www.microsoft.com/en-in/download/details.aspx?id=48145

Note:- Take backup of your project files before uninstall

How to convert index of a pandas dataframe into a column?

For MultiIndex you can extract its subindex using

df['si_name'] = R.index.get_level_values('si_name') 

where si_name is the name of the subindex.

Laravel 5.2 Missing required parameters for [Route: user.profile] [URI: user/{nickname}/profile]

My Solution in laravel 5.2

{{ Form::open(['route' => ['votes.submit', $video->id],  'method' => 'POST']) }}
    <button type="submit" class="btn btn-primary">
        <span class="glyphicon glyphicon-thumbs-up"></span> Votar
    </button>
{{ Form::close() }}

My Routes File (under middleware)

Route::post('votar/{id}', [
    'as' => 'votes.submit',
    'uses' => 'VotesController@submit'
]);

Route::delete('votar/{id}', [
    'as' => 'votes.destroy',
    'uses' => 'VotesController@destroy'
]);

ExecuteReader: Connection property has not been initialized

You can also write this:

SqlCommand cmd=new SqlCommand ("insert into time(project,iteration) values (@project, @iteration)", conn);
cmd.Parameters.AddWithValue("@project",name1.SelectedValue);
cmd.Parameters.AddWithValue("@iteration",iteration.SelectedValue);

How do I reverse a C++ vector?

You can use std::reverse like this

std::reverse(str.begin(), str.end());

combining results of two select statements

While it is possible to combine the results, I would advise against doing so.

You have two fundamentally different types of queries that return a different number of rows, a different number of columns and different types of data. It would be best to leave it as it is - two separate queries.

What is the difference between SQL and MySQL?

SQL is Structured Query Language

MySQL is a relational database management system. You can submit SQL queries to the MySQL database to store, retrieve, modify or delete data.

How to convert a multipart file to File?

You can get the content of a MultipartFile by using the getBytes method and you can write to the file using Files.newOutputStream():

public void write(MultipartFile file, Path dir) {
    Path filepath = Paths.get(dir.toString(), file.getOriginalFilename());

    try (OutputStream os = Files.newOutputStream(filepath)) {
        os.write(file.getBytes());
    }
}

You can also use the transferTo method:

public void multipartFileToFile(
    MultipartFile multipart, 
    Path dir
) throws IOException {
    Path filepath = Paths.get(dir.toString(), multipart.getOriginalFilename());
    multipart.transferTo(filepath);
}

fs: how do I locate a parent folder?

This works fine

path.join(__dirname + '/../client/index.html')
const path = require('path')
const fs = require('fs')
    fs.readFile(path.join(__dirname + '/../client/index.html'))

Angular 2: How to style host element of the component?

In your Component you can add .class to your host element if you would have some general styles that you want to apply.

export class MyComponent{
     @HostBinding('class') classes = 'classA classB';

How to make Java honor the DNS Caching Timeout?

So I decided to look at the java source code because I found official docs a bit confusing. And what I found (for OpenJDK 11) mostly aligns with what others have written. What is important is the order of evaluation of properties.

InetAddressCachePolicy.java (I'm omitting some boilerplate for readability):


String tmpString = Security.getProperty("networkaddress.cache.ttl");
if (tmpString != null) {
   tmp = Integer.valueOf(tmpString);
   return;
}
...
String tmpString = System.getProperty("sun.net.inetaddr.ttl");
if (tmpString != null) {
   tmp = Integer.valueOf(tmpString);
   return;
}
...
if (tmp != null) {
  cachePolicy = tmp < 0 ? FOREVER : tmp;
  propertySet = true;
} else {
  /* No properties defined for positive caching. If there is no
  * security manager then use the default positive cache value.
  */
  if (System.getSecurityManager() == null) {
    cachePolicy = 30;
  }
}

You can clearly see that the security property is evaluated first, system property second and if any of them is set cachePolicy value is set to that number or -1 (FOREVER) if they hold a value that is bellow -1. If nothing is set it defaults to 30 seconds. As it turns out for OpenJDK that is almost always the case because by default java.security does not set that value, only a negative one.

#networkaddress.cache.ttl=-1 <- this line is commented out
networkaddress.cache.negative.ttl=10

BTW if the networkaddress.cache.negative.ttl is not set (removed from the file) the default inside the java class is 0. Documentation is wrong in this regard. This is what tripped me over.

Subclipse svn:ignore

I was able to do this using TortoiseSVN directly from Windows explorer:

Right click on file to ignore->TortiseSVN->Delete and add to ignore list

I had to close then re-open the project in Eclipse, job done :)

What is the difference between square brackets and parentheses in a regex?

The first 2 examples act very differently if you are REPLACING them by something. If you match on this:

str = str.replace(/^(7|8|9)/ig,''); 

you would replace 7 or 8 or 9 by the empty string.

If you match on this

str = str.replace(/^[7|8|9]/ig,''); 

you will replace 7 or 8 or 9 OR THE VERTICAL BAR!!!! by the empty string.

I just found this out the hard way.

Alternative to itoa() for converting integer to string C++?

boost::lexical_cast works pretty well.

#include <boost/lexical_cast.hpp>
int main(int argc, char** argv) {
    std::string foo = boost::lexical_cast<std::string>(argc);
}

Get array elements from index to end

The [:-1] removes the last element. Instead of

a[3:-1]

write

a[3:]

You can read up on Python slicing notation here: Explain Python's slice notation

NumPy slicing is an extension of that. The NumPy tutorial has some coverage: Indexing, Slicing and Iterating.

Why does viewWillAppear not get called when an app comes back from the background?

It's even easier with SwiftUI:

var body: some View {     
    Text("Hello World")
    .onReceive(NotificationCenter.default.publisher(for: UIApplication.willResignActiveNotification)) { _ in
        print("Moving to background!")
    }
    .onReceive(NotificationCenter.default.publisher(for: UIApplication.willEnterForegroundNotification)) { _ in
        print("Moving back to foreground!")
    }   
}

How to get request URL in Spring Boot RestController

Add a parameter of type UriComponentsBuilder to your controller method. Spring will give you an instance that's preconfigured with the URI for the current request, and you can then customize it (such as by using MvcUriComponentsBuilder.relativeTo to point at a different controller using the same prefix).

Nth word in a string variable

echo $STRING | cut -d " " -f $N

How to update Ruby with Homebrew?

To upgrade Ruby with rbenv: Per the rbenv README

  • Update first: brew upgrade rbenv ruby-build
  • See list of Ruby versions: versions available: rbenv install -l
  • Install: rbenv install <selected version>

How can I multiply all items in a list together with Python?

It is very simple do not import anything. This is my code. This will define a function that multiplies all the items in a list and returns their product.

def myfunc(lst):
    multi=1
    for product in lst:
        multi*=product
    return product

How do I directly modify a Google Chrome Extension File? (.CRX)

Installed Chrome extension directories are listed below:

  1. Copy the folder of the extension you wish to modify. ( Named according to the extension ID, to find the ID of the extension, go to chrome://extensions/). Once copied, you have to remove the _metadata folder.

  2. From chrome://extensions in Developer mode select Load unpacked extension... and select your copied extension folder, if it contains a subfolder this is named by the version, select this version folder where there is a manifest file, this file is necessary for Chrome.

  3. Make your changes, then select reload and refresh the page for your extension to see your changes.


Chrome extension directories

Mac:

/Users/username/Library/Application Support/Google/Chrome/Default/Extensions

Windows 7:

C:\Users\username\AppData\Local\Google\Chrome\User Data\Default\Extensions

Windows XP:

C:\Documents and Settings\YourUserName\Local Settings\Application Data\Google\Chrome\User Data\Default

Ubuntu 14.04:

~/.config/google-chrome/Default/Extensions/

What's alternative to angular.copy in Angular

I have created a service to use with Angular 5 or higher, it uses the angular.copy() the base of angularjs, it works well for me. Additionally, there are other functions like isUndefined, etc. I hope it helps. Like any optimization, it would be nice to know. regards

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

@Injectable({providedIn: 'root'})
export class AngularService {

  private TYPED_ARRAY_REGEXP = /^\[object (?:Uint8|Uint8Clamped|Uint16|Uint32|Int8|Int16|Int32|Float32|Float64)Array\]$/;
  private stackSource = [];
  private stackDest = [];

  constructor() { }

  public isNumber(value: any): boolean {
    if ( typeof value === 'number' ) { return true; }
    else { return false; }
  }

  public isTypedArray(value: any) {
    return value && this.isNumber(value.length) && this.TYPED_ARRAY_REGEXP.test(toString.call(value));
  }

  public isArrayBuffer(obj: any) {
    return toString.call(obj) === '[object ArrayBuffer]';
  }

  public isUndefined(value: any) {return typeof value === 'undefined'; }

  public isObject(value: any) {  return value !== null && typeof value === 'object'; }

  public isBlankObject(value: any) {
    return value !== null && typeof value === 'object' && !Object.getPrototypeOf(value);
  }

  public isFunction(value: any) { return typeof value === 'function'; }

  public setHashKey(obj: any, h: any) {
    if (h) { obj.$$hashKey = h; }
    else { delete obj.$$hashKey; }
  }

  private isWindow(obj: any) { return obj && obj.window === obj; }

  private isScope(obj: any) { return obj && obj.$evalAsync && obj.$watch; }


  private copyRecurse(source: any, destination: any) {

    const h = destination.$$hashKey;

    if (Array.isArray(source)) {
      for (let i = 0, ii = source.length; i < ii; i++) {
        destination.push(this.copyElement(source[i]));
      }
    } else if (this.isBlankObject(source)) {
      for (const key of Object.keys(source)) {
        destination[key] = this.copyElement(source[key]);
      }
    } else if (source && typeof source.hasOwnProperty === 'function') {
      for (const key of Object.keys(source)) {
        destination[key] = this.copyElement(source[key]);
      }
    } else {
      for (const key of Object.keys(source)) {
        destination[key] = this.copyElement(source[key]);
      }
    }
    this.setHashKey(destination, h);
    return destination;
  }

  private copyElement(source: any) {

    if (!this.isObject(source)) {
      return source;
    }

    const index = this.stackSource.indexOf(source);

    if (index !== -1) {
      return this.stackDest[index];
    }

    if (this.isWindow(source) || this.isScope(source)) {
      throw console.log('Cant copy! Making copies of Window or Scope instances is not supported.');
    }

    let needsRecurse = false;
    let destination = this.copyType(source);

    if (destination === undefined) {
      destination = Array.isArray(source) ? [] : Object.create(Object.getPrototypeOf(source));
      needsRecurse = true;
    }

    this.stackSource.push(source);
    this.stackDest.push(destination);

    return needsRecurse
      ? this.copyRecurse(source, destination)
      : destination;
  }

  private copyType = (source: any) => {

    switch (toString.call(source)) {
      case '[object Int8Array]':
      case '[object Int16Array]':
      case '[object Int32Array]':
      case '[object Float32Array]':
      case '[object Float64Array]':
      case '[object Uint8Array]':
      case '[object Uint8ClampedArray]':
      case '[object Uint16Array]':
      case '[object Uint32Array]':
        return new source.constructor(this.copyElement(source.buffer), source.byteOffset, source.length);

      case '[object ArrayBuffer]':
        if (!source.slice) {
          const copied = new ArrayBuffer(source.byteLength);
          new Uint8Array(copied).set(new Uint8Array(source));
          return copied;
        }
        return source.slice(0);

      case '[object Boolean]':
      case '[object Number]':
      case '[object String]':
      case '[object Date]':
        return new source.constructor(source.valueOf());

      case '[object RegExp]':
        const re = new RegExp(source.source, source.toString().match(/[^\/]*$/)[0]);
        re.lastIndex = source.lastIndex;
        return re;

      case '[object Blob]':
        return new source.constructor([source], {type: source.type});
    }

    if (this.isFunction(source.cloneNode)) {
      return source.cloneNode(true);
    }
  }

  public copy(source: any, destination?: any) {

    if (destination) {
      if (this.isTypedArray(destination) || this.isArrayBuffer(destination)) {
        throw console.log('Cant copy! TypedArray destination cannot be mutated.');
      }
      if (source === destination) {
        throw console.log('Cant copy! Source and destination are identical.');
      }

      if (Array.isArray(destination)) {
        destination.length = 0;
      } else {
        destination.forEach((value: any, key: any) => {
          if (key !== '$$hashKey') {
            delete destination[key];
          }
        });
      }

      this.stackSource.push(source);
      this.stackDest.push(destination);
      return this.copyRecurse(source, destination);
    }

    return this.copyElement(source);
  }
}
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How do AX, AH, AL map onto EAX?

AX is the 16 lower bits of EAX. AH is the 8 high bits of AX (i.e. the bits 8-15 of EAX) and AL is the least significant byte (bits 0-7) of EAX as well as AX.

Example (Hexadecimal digits):

EAX: 12 34 56 78
AX: 56 78
AH: 56
AL: 78

.NET / C# - Convert char[] to string

Another alternative

char[] c = { 'R', 'o', 'c', 'k', '-', '&', '-', 'R', 'o', 'l', 'l' };
string s = String.Concat( c );

Debug.Assert( s.Equals( "Rock-&-Roll" ) );

Java Code for calculating Leap Year

import javax.swing.*;
public class LeapYear {
    public static void main(String[] args) {
    int year;
String yearStr = JOptionPane.showInputDialog(null, "Enter radius: " );

year = Integer.parseInt( yearStr );

boolean isLeapYear;
isLeapYear = (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0);  

 if(isLeapYear){ 
JOptionPane.showMessageDialog(null, "Leap Year!"); 
 }  
 else{
JOptionPane.showMessageDialog(null, "Not a Leap Year!"); 
    }
    }
    }

What and where are the stack and heap?

Stack:

  • Stored in computer RAM just like the heap.
  • Variables created on the stack will go out of scope and are automatically deallocated.
  • Much faster to allocate in comparison to variables on the heap.
  • Implemented with an actual stack data structure.
  • Stores local data, return addresses, used for parameter passing.
  • Can have a stack overflow when too much of the stack is used (mostly from infinite or too deep recursion, very large allocations).
  • Data created on the stack can be used without pointers.
  • You would use the stack if you know exactly how much data you need to allocate before compile time and it is not too big.
  • Usually has a maximum size already determined when your program starts.

Heap:

  • Stored in computer RAM just like the stack.
  • In C++, variables on the heap must be destroyed manually and never fall out of scope. The data is freed with delete, delete[], or free.
  • Slower to allocate in comparison to variables on the stack.
  • Used on demand to allocate a block of data for use by the program.
  • Can have fragmentation when there are a lot of allocations and deallocations.
  • In C++ or C, data created on the heap will be pointed to by pointers and allocated with new or malloc respectively.
  • Can have allocation failures if too big of a buffer is requested to be allocated.
  • You would use the heap if you don't know exactly how much data you will need at run time or if you need to allocate a lot of data.
  • Responsible for memory leaks.

Example:

int foo()
{
  char *pBuffer; //<--nothing allocated yet (excluding the pointer itself, which is allocated here on the stack).
  bool b = true; // Allocated on the stack.
  if(b)
  {
    //Create 500 bytes on the stack
    char buffer[500];

    //Create 500 bytes on the heap
    pBuffer = new char[500];

   }//<-- buffer is deallocated here, pBuffer is not
}//<--- oops there's a memory leak, I should have called delete[] pBuffer;

Regex allow a string to only contain numbers 0 - 9 and limit length to 45

Use this regular expression if you don't want to start with zero:

^[1-9]([0-9]{1,45}$)

If you don't mind starting with zero, use:

^[0-9]{1,45}$

Intro to GPU programming

Take a look at the ATI Stream Computing SDK. It is based on BrookGPU developed at Stanford.

In the future all GPU work will be standardized using OpenCL. It's an Apple-sponsored initiative that will be graphics card vendor neutral.

How to set array length in c# dynamically

You can create an array dynamically in this way:

 static void Main()
    {
        // Create a string array 2 elements in length:
        int arrayLength = 2;
        Array dynamicArray = Array.CreateInstance(typeof(int), arrayLength);
        dynamicArray.SetValue(234, 0);                              //  ? a[0] = 234;
        dynamicArray.SetValue(444, 1);                              //  ? a[1] = 444;
        int number = (int)dynamicArray.GetValue(0);                      //  ? number = a[0];


        int[] cSharpArray = (int[])dynamicArray;
        int s2 = cSharpArray[0];

    }

How to check encoding of a CSV file

You can also use python chardet library

# install the chardet library
!pip install chardet

# import the chardet library
import chardet 

# use the detect method to find the encoding
# 'rb' means read in the file as binary
with open("test.csv", 'rb') as file:
    print(chardet.detect(file.read()))

Run a mySQL query as a cron job?

Try creating a shell script like the one below:

#!/bin/bash

mysql --user=[username] --password=[password] --database=[db name] --execute="DELETE FROM tbl_message WHERE DATEDIFF( NOW( ) ,  timestamp ) >=7"

You can then add this to the cron

How can I get current date in Android?

This is the code i used:

             Date date = new Date();  // to get the date
             SimpleDateFormat df = new SimpleDateFormat("dd-MM-yyyy"); // getting date in this format
             String formattedDate = df.format(date.getTime());
             text.setText(formattedDate);

Html.Textbox VS Html.TextboxFor

The TextBoxFor is a newer MVC input extension introduced in MVC2.

The main benefit of the newer strongly typed extensions is to show any errors / warnings at compile-time rather than runtime.

See this page.

http://weblogs.asp.net/scottgu/archive/2010/01/10/asp-net-mvc-2-strongly-typed-html-helpers.aspx

What is going wrong when Visual Studio tells me "xcopy exited with code 4"

As other answers explain, exit code 4 may have many causes.

I noticed a case, where resulting path names exceeded the maximum allowed length (just like here).

I have replaced xcopy by robocopy for the affected post build event; robocopy seems to handle paths slightly different and was able to complete the copy task that xcopy was unable to handle.

Java code for getting current time

try this:

final String currentTime    = String.valueOf(System.currentTimeMillis());

Aren't promises just callbacks?

No promises are just wrapper on callbacks

example You can use javascript native promises with node js

my cloud 9 code link : https://ide.c9.io/adx2803/native-promises-in-node

/**
* Created by dixit-lab on 20/6/16.
*/

var express = require('express');
var request = require('request');   //Simplified HTTP request client.


var app = express();

function promisify(url) {
    return new Promise(function (resolve, reject) {
    request.get(url, function (error, response, body) {
    if (!error && response.statusCode == 200) {
        resolve(body);
    }
    else {
        reject(error);
    }
    })
    });
}

//get all the albums of a user who have posted post 100
app.get('/listAlbums', function (req, res) {
//get the post with post id 100
promisify('http://jsonplaceholder.typicode.com/posts/100').then(function (result) {
var obj = JSON.parse(result);
return promisify('http://jsonplaceholder.typicode.com/users/' + obj.userId + '/albums')
})
.catch(function (e) {
    console.log(e);
})
.then(function (result) {
    res.end(result);
}
)

})


var server = app.listen(8081, function () {

var host = server.address().address
var port = server.address().port

console.log("Example app listening at http://%s:%s", host, port)

})


//run webservice on browser : http://localhost:8081/listAlbums

PostgreSQL naming conventions

There isn't really a formal manual, because there's no single style or standard.

So long as you understand the rules of identifier naming you can use whatever you like.

In practice, I find it easier to use lower_case_underscore_separated_identifiers because it isn't necessary to "Double Quote" them everywhere to preserve case, spaces, etc.

If you wanted to name your tables and functions "@MyA??! ""betty"" Shard$42" you'd be free to do that, though it'd be pain to type everywhere.

The main things to understand are:

  • Unless double-quoted, identifiers are case-folded to lower-case, so MyTable, MYTABLE and mytable are all the same thing, but "MYTABLE" and "MyTable" are different;

  • Unless double-quoted:

    SQL identifiers and key words must begin with a letter (a-z, but also letters with diacritical marks and non-Latin letters) or an underscore (_). Subsequent characters in an identifier or key word can be letters, underscores, digits (0-9), or dollar signs ($).

  • You must double-quote keywords if you wish to use them as identifiers.

In practice I strongly recommend that you do not use keywords as identifiers. At least avoid reserved words. Just because you can name a table "with" doesn't mean you should.

Calling a rest api with username and password - how to

If the API says to use HTTP Basic authentication, then you need to add an Authorization header to your request. I'd alter your code to look like this:

    WebRequest req = WebRequest.Create(@"https://sub.domain.com/api/operations?param=value&param2=value");
    req.Method = "GET";
    req.Headers["Authorization"] = "Basic " + Convert.ToBase64String(Encoding.Default.GetBytes("username:password"));
    //req.Credentials = new NetworkCredential("username", "password");
    HttpWebResponse resp = req.GetResponse() as HttpWebResponse;

Replacing "username" and "password" with the correct values, of course.

Joining two lists together

List<string> list1 = new List<string>();
list1.Add("dot");
list1.Add("net");

List<string> list2 = new List<string>();
list2.Add("pearls");
list2.Add("!");

var result = list1.Concat(list2);

Where to install Android SDK on Mac OS X?

You can install android-sdk in different ways

  1. homebrew
    Install brew using command from brew.sh

    /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"  
    

    Install android-sdk using

    brew install android-sdk
    

    Now android-sdk will be installed in /usr/local/opt/android-sdk

    export ANDROID_HOME=/usr/local/opt/android-sdk
    
  2. If you installed android studio following the website,
    android-sdk will be installed in ~/Library/Android/sdk

    export ANDROID_HOME=~/Library/Android/sdk
    

I think these defaults make sense and its better to stick to it

How to use the gecko executable with Selenium

Recently Selenium has launched Selenium 3 and if you are trying to use Firefox latest version then you have to use GeckoDriver:

System.setProperty("webdriver.gecko.driver","G:\\Selenium\\Firefox driver\\geckodriver.exe");
WebDriver driver = new FirefoxDriver();

You can check full documentation from here

How exactly to use Notification.Builder

This is in API 11, so if you are developing for anything earlier than 3.0 you should continue to use the old API.

Update: the NotificationCompat.Builder class has been added to the Support Package so we can use this to support API level v4 and up:

http://developer.android.com/reference/android/support/v4/app/NotificationCompat.Builder.html

How to write a simple Html.DropDownListFor()?

<%: 
     Html.DropDownListFor(
           model => model.Color, 
           new SelectList(
                  new List<Object>{ 
                       new { value = 0 , text = "Red"  },
                       new { value = 1 , text = "Blue" },
                       new { value = 2 , text = "Green"}
                    },
                  "value",
                  "text",
                   Model.Color
           )
        )
%>

or you can write no classes, put something like this directly to the view.

How can I convert a comma-separated string to an array?

Watch out if you are aiming at integers, like 1,2,3,4,5. If you intend to use the elements of your array as integers and not as strings after splitting the string, consider converting them into such.

var str = "1,2,3,4,5,6";
var temp = new Array();
// This will return an array with strings "1", "2", etc.
temp = str.split(",");

Adding a loop like this,

for (a in temp ) {
    temp[a] = parseInt(temp[a], 10); // Explicitly include base as per Álvaro's comment
}

will return an array containing integers, and not strings.

How to refresh page on back button click?

did you try something like this? not tested...

$(document).ready(function(){
    $('.ajaxAnchor').on('click', function (event){ 
        event.preventDefault(); 
        var url = $(this).attr('href');
        $.get(url, function(data) {
            $('section.center').html(data);
            var shortened = url.substring(0,url.length - 5);
            window.location.hash = shortened;
        });
    });
});

How to read a configuration file in Java

Create a configuration file and put your entries there.

SERVER_PORT=10000     
THREAD_POOL_COUNT=3     
ROOT_DIR=/home/   

You can load this file using Properties.load(fileName) and retrieved values you get(key);

How can I show and hide elements based on selected option with jQuery?

You're running the code before the DOM is loaded.

Try this:

Live example:

http://jsfiddle.net/FvMYz/

$(function() {    // Makes sure the code contained doesn't run until
                  //     all the DOM elements have loaded

    $('#colorselector').change(function(){
        $('.colors').hide();
        $('#' + $(this).val()).show();
    });

});

How can I programmatically freeze the top row of an Excel worksheet in Excel 2007 VBA?

Rows("2:2").Select
ActiveWindow.FreezePanes = True

Select a different range for a different effect, much the same way you would do manually. The "Freeze Top Row" really just is a shortcut new in Excel 2007 (and up), it contains no added functionality compared to earlier versions of Excel.

Creating temporary files in bash

Yes, use mktemp.

It will create a temporary file inside a folder that is designed for storing temporary files, and it will guarantee you a unique name. It outputs the name of that file:

> mktemp
/tmp/tmp.xx4mM3ePQY
>

Turn off textarea resizing

CSS3 can solve this problem. Unfortunately it's only supported on 60% of used browsers nowadays.

For IE and iOS you can't turn off resizing but you can limit the textarea dimension by setting its width and height.

/* One can also turn on/off specific axis. Defaults to both on. */
textarea { resize:vertical; } /* none|horizontal|vertical|both */

See Demo

How to do the Recursive SELECT query in MySQL?

The accepted answer by @Meherzad only works if the data is in a particular order. It happens to work with the data from the OP question. In my case, I had to modify it to work with my data.

Note This only works when every record's "id" (col1 in the question) has a value GREATER THAN that record's "parent id" (col3 in the question). This is often the case, because normally the parent will need to be created first. However if your application allows changes to the hierarchy, where an item may be re-parented somewhere else, then you cannot rely on this.

This is my query in case it helps someone; note it does not work with the given question because the data does not follow the required structure described above.

select t.col1, t.col2, @pv := t.col3 col3
from (select * from table1 order by col1 desc) t
join (select @pv := 1) tmp
where t.col1 = @pv

The difference is that table1 is being ordered by col1 so that the parent will be after it (since the parent's col1 value is lower than the child's).

How do I save a String to a text file using Java?

In Java 11 the java.nio.file.Files class was extended by two new utility methods to write a string into a file. The first method (see JavaDoc here) uses the charset UTF-8 as default:

Files.writeString(Path.of("my", "path"), "My String");

And the second method (see JavaDoc here) allows to specify an individual charset:

Files.writeString(Path.of("my", "path"), "My String", StandardCharset.ISO_8859_1);

Both methods have an optional Varargs parameter for setting file handling options (see JavaDoc here). The following example would create a non-existing file or append the string to an existing one:

Files.writeString(Path.of("my", "path"), "String to append", StandardOpenOption.CREATE, StandardOpenOption.APPEND);

How to improve performance of ngRepeat over a huge dataset (angular.js)?

If all your rows have equal height, you should definitely take a look at the virtualizing ng-repeat: http://kamilkp.github.io/angular-vs-repeat/

This demo looks very promising (and it supports inertial scrolling)

What is the difference between Python's list methods append and extend?

Append adds the entire data at once. The whole data will be added to the newly created index. On the other hand, extend, as it name suggests, extends the current array.

For example

list1 = [123, 456, 678]
list2 = [111, 222]

With append we get:

result = [123, 456, 678, [111, 222]]

While on extend we get:

result = [123, 456, 678, 111, 222]

PHP: Count a stdClass object

Just use this

$i=0;
foreach ($object as $key =>$value)
{
$i++;
}

the variable $i is number of keys.

JavaScript for...in vs for

The choice should be based on the which idiom is best understood.

An array is iterated using:

for (var i = 0; i < a.length; i++)
   //do stuff with a[i]

An object being used as an associative array is iterated using:

for (var key in o)
  //do stuff with o[key]

Unless you have earth shattering reasons, stick to the established pattern of usage.

How do I create dynamic properties in C#?

Create a Hashtable called "Properties" and add your properties to it.

How to get a pixel's x,y coordinate color from an image?

With : i << 2

const data = context.getImageData(x, y, width, height).data;
const pixels = [];

for (let i = 0, dx = 0; dx < data.length; i++, dx = i << 2) {
    if (data[dx+3] <= 8)
        console.log("transparent x= " + i);
}

How to use cURL to get jSON data and decode the data?

You can Use this for Curl:

function fakeip()  
{  
    return long2ip( mt_rand(0, 65537) * mt_rand(0, 65535) );   
}  

function getdata($url,$args=false) 
{ 
    global $session; 
    $ch = curl_init(); 
    curl_setopt($ch, CURLOPT_URL,$url); 
    curl_setopt($ch, CURLOPT_HTTPHEADER, array("REMOTE_ADDR: ".fakeip(),"X-Client-IP: ".fakeip(),"Client-IP: ".fakeip(),"HTTP_X_FORWARDED_FOR: ".fakeip(),"X-Forwarded-For: ".fakeip())); 
    if($args) 
    { 
        curl_setopt($ch, CURLOPT_POST, 1); 
        curl_setopt($ch, CURLOPT_POSTFIELDS,$args); 
    } 
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); 
    //curl_setopt($ch, CURLOPT_PROXY, "127.0.0.1:8888"); 
    $result = curl_exec ($ch); 
    curl_close ($ch); 
    return $result; 
} 

Then To Read Json:

$result=getdata("https://example.com");

Then :

///Deocde Json
$data = json_decode($result,true);
///Count
             $total=count($data);
             $Str='<h1>Total : '.$total.'';
             echo $Str;
//You Can Also Make In Table:
             foreach ($data as $key => $value)
              {
          echo '  <td><font  face="calibri"color="red">'.$value[type].'   </font></td><td><font  face="calibri"color="blue">'.$value[category].'   </font></td><td><font  face="calibri"color="green">'.$value[amount].'   </font></tr><tr>';

           }
           echo "</tr></table>";
           }

You Can Also Use This:

echo '<p>Name : '.$data['result']['name'].'</p>
      <img src="'.$data['result']['pic'].'"><br>';

Hope this helped.

How to get primary key column in Oracle?

Try This Code Here I created a table for get primary key column in oracle which is called test and then query

create table test
(
id int,
name varchar2(20),
city varchar2(20),
phone int,
constraint pk_id_name_city primary key (id,name,city)
);

SELECT cols.table_name, cols.column_name, cols.position, cons.status, cons.owner FROM all_constraints cons, all_cons_columns cols WHERE cols.table_name = 'TEST' AND cons.constraint_type = 'P' AND cons.constraint_name = cols.constraint_name AND cons.owner = cols.owner  ORDER BY cols.table_name, cols.position;

How to change the default docker registry from docker.io to my private registry?

UPDATE: Following your comment, it is not currently possible to change the default registry, see this issue for more info.

You should be able to do this, substituting the host and port to your own:

docker pull localhost:5000/registry-demo

If the server is remote/has auth you may need to log into the server with:

docker login https://<YOUR-DOMAIN>:8080

Then running:

docker pull <YOUR-DOMAIN>:8080/test-image

angular2: how to copy object into another object

let copy = Object.assign({}, myObject).  as mentioned above

but this wont work for nested objects. SO an alternative would be

let copy =JSON.parse(JSON.stringify(myObject))

Get Selected value of a Combobox

A simpler way to get the selected value from a ComboBox control is:

Private Sub myComboBox_Change()
  msgbox "You selected: " + myComboBox.SelText
End Sub

React proptype array with shape

If I am to define the same proptypes for a particular shape multiple times, I like abstract it out to a proptypes file so that if the shape of the object changes, I only have to change the code in one place. It helps dry up the codebase a bit.

Example:

// Inside my proptypes.js file
import PT from 'prop-types';

export const product = {
  id: PT.number.isRequired,
  title: PT.string.isRequired,
  sku: PT.string.isRequired,
  description: PT.string.isRequired,
};


// Inside my component file
import PT from 'prop-types';
import { product } from './proptypes;


List.propTypes = {
  productList: PT.arrayOf(product)
}

DropdownList DataSource

It depends on how you set the defaults for the dropdown. Use selected value, but you have to set the selected value. For instance, I populate the datasource with the name and id field for the table/list. I set the selected value to the id field and the display to the name. When I select, I get the id field. I use this to search a relational table and find an entity/record.

Sending string via socket (python)

This piece of code is incorrect.

while 1:
    (clientsocket, address) = serversocket.accept()
    print ("connection found!")
    data = clientsocket.recv(1024).decode()
    print (data)
    r='REceieve'
    clientsocket.send(r.encode())

The call on accept() on the serversocket blocks until there's a client connection. When you first connect to the server from the client, it accepts the connection and receives data. However, when it enters the loop again, it is waiting for another connection and thus blocks as there are no other clients that are trying to connect.

That's the reason the recv works correct only the first time. What you should do is find out how you can handle the communication with a client that has been accepted - maybe by creating a new Thread to handle communication with that client and continue accepting new clients in the loop, handling them in the same way.

Tip: If you want to work on creating your own chat application, you should look at a networking engine like Twisted. It will help you understand the whole concept better too.

Changing specific text's color using NSMutableAttributedString in Swift

Swift 4.1

I have changed from this In Swift 3

let str = "Welcome "
let welcomeAttribute = [ NSForegroundColorAttributeName: UIColor.blue()]
let welcomeAttrString = NSMutableAttributedString(string: str, attributes: welcomeAttribute)

And this in Swift 4.0

let str = "Welcome "
let welcomeAttribute = [ NSAttributedStringKey.foregroundColor: UIColor.blue()]
let welcomeAttrString = NSMutableAttributedString(string: str, attributes: welcomeAttribute)

to Swift 4.1

let str = "Welcome "
let welcomeAttribute = [ NSAttributedStringKey(rawValue: NSForegroundColorAttributeName): UIColor.blue()]
let welcomeAttrString = NSMutableAttributedString(string: str, attributes: welcomeAttribute)

Works fine

Change a Django form field to a hidden field

Firstly, if you don't want the user to modify the data, then it seems cleaner to simply exclude the field. Including it as a hidden field just adds more data to send over the wire and invites a malicious user to modify it when you don't want them to. If you do have a good reason to include the field but hide it, you can pass a keyword arg to the modelform's constructor. Something like this perhaps:

class MyModelForm(forms.ModelForm):
    class Meta:
        model = MyModel
    def __init__(self, *args, **kwargs):
        from django.forms.widgets import HiddenInput
        hide_condition = kwargs.pop('hide_condition',None)
        super(MyModelForm, self).__init__(*args, **kwargs)
        if hide_condition:
            self.fields['fieldname'].widget = HiddenInput()
            # or alternately:  del self.fields['fieldname']  to remove it from the form altogether.

Then in your view:

form = MyModelForm(hide_condition=True)

I prefer this approach to modifying the modelform's internals in the view, but it's a matter of taste.

jQuery UI dialog box not positioned center screen

Are you adding jquery.ui.position.js to your page? I had the same problem, checked the source code here and realized I didn't add that js to my page, after that.. dialog magically centered.

using javascript to detect whether the url exists before display in iframe

You could test the url via AJAX and read the status code - that is if the URL is in the same domain.

If it's a remote domain, you could have a server script on your own domain check out a remote URL.

ASP.NET Core - Swashbuckle not creating swagger.json file

Answer:

If using directories or application  with IIS or a reverse proxy,<br/> set the Swagger endpoint to a relative path using the ./ prefix. For example,<br/> ./swagger/v1/swagger.json. Using /swagger/v1/swagger.json instructs the app to<br/>look for the JSON file at the true root of the URL (plus the route prefix, if used). For example, use http://localhost:<br/><br/><port>/<route_prefix>/swagger/v1/swagger.json instead of http://localhost:<br/><port>/<virtual_directory>/<route_prefix>/swagger/v1/swagger.json.<br/>
if (env.IsDevelopment())
{
    app.UseDeveloperExceptionPage();

    // Enable middleware to serve generated Swagger as a JSON endpoint.
    app.UseSwagger();
    app.UseSwaggerUI(c =>
    {
//c.SwaggerEndpoint("/swagger/v1/swagger.json", "MyAPI V1");
//Add dot in front of swagger path so that it takes relative path in server
c.SwaggerEndpoint("./swagger/v1/swagger.json", "MyAPI V1");
    });
}

[Detail description of the swagger integration to web api core 3.0][1]


  [1]: https://docs.microsoft.com/en-us/aspnet/core/tutorials/getting-started-with-swashbuckle?view=aspnetcore-3.1&tabs=visual-studio

Select multiple records based on list of Id's with linq

That should be simple. Try this:

var idList = new int[1, 2, 3, 4, 5];
var userProfiles = _dataContext.UserProfile.Where(e => idList.Contains(e));

Get string character by index - Java

CharAt function not working

Edittext.setText(YourString.toCharArray(),0,1);

This code working fine

Jquery Value match Regex

Change it to this:

var email = /^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i;

This is a regular expression literal that is passed the i flag which means to be case insensitive.

Keep in mind that email address validation is hard (there is a 4 or 5 page regular expression at the end of Mastering Regular Expressions demonstrating this) and your expression certainly will not capture all valid e-mail addresses.