Programs & Examples On #Tablerowsorter

TableRowSorter is An implementation of RowSorter that provides sorting and filtering using a TableModel.

What is the difference between display: inline and display: inline-block?

A visual answer

Imagine a <span> element inside a <div>. If you give the <span> element a height of 100px and a red border for example, it will look like this with

display: inline

display: inline

display: inline-block

display: inline-block

display: block

enter image description here

Code: http://jsfiddle.net/Mta2b/

Elements with display:inline-block are like display:inline elements, but they can have a width and a height. That means that you can use an inline-block element as a block while flowing it within text or other elements.

Difference of supported styles as summary:

  • inline: only margin-left, margin-right, padding-left, padding-right
  • inline-block: margin, padding, height, width

How to change href of <a> tag on button click through javascript

To have a link dynamically change on clicking it:

<input type="text" id="emailOfBookCustomer" style="direction:RTL;"></input>
        <a 
         onclick="this.href='<%= request.getContextPath() %>/Jahanpay/forwardTo.jsp?handle=<%= handle %>&Email=' + document.getElementById('emailOfBookCustomer').value;" href=''>
    A dynamic link 
            </a>

PHP create key => value pairs within a foreach

function createOfferUrlArray($Offer) {
    $offerArray = array();
    foreach ($Offer as $key => $value) { 
        $offerArray[$key] = $value[4];
    }
    return $offerArray;
}

or

function createOfferUrlArray($offer) {
    foreach ( $offer as &$value ) {
        $value = $value[4];
    }
    unset($value);
    return $offer;
}

git replace local version with remote version

I understand the question as this: you want to completely replace the contents of one file (or a selection) from upstream. You don't want to affect the index directly (so you would go through add + commit as usual).

Simply do

git checkout remote/branch -- a/file b/another/file

If you want to do this for extensive subtrees and instead wish to affect the index directly use

git read-tree remote/branch:subdir/

You can then (optionally) update your working copy by doing

git checkout-index -u --force

how to convert string into time format and add two hours

Being a fan of the Joda Time library, here's how you can do it that way using a Joda DateTime:

import org.joda.time.format.*;
import org.joda.time.*;

...    

String dateString = "2009-04-17 10:41:33";

// parse the string
DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MM-dd HH:mm:ss");
DateTime dateTime = formatter.parseDateTime(dateString);

// add two hours
dateTime = dateTime.plusHours(2); // easier than mucking about with Calendar and constants

System.out.println(dateTime);

If you still need to use java.util.Date objects before/after this conversion, the Joda DateTime API provides some easy toDate() and toCalendar() methods for easy translation.

The Joda API provides so much more in the way of convenience over the Java Date/Calendar API.

How can I control the width of a label tag?

You can definitely try this way

.col-form-label{
  display: inline-block;
  width:200px;}

Make an HTTP request with android

unless you have an explicit reason to choose the Apache HttpClient, you should prefer java.net.URLConnection. you can find plenty of examples of how to use it on the web.

we've also improved the Android documentation since your original post: http://developer.android.com/reference/java/net/HttpURLConnection.html

and we've talked about the trade-offs on the official blog: http://android-developers.blogspot.com/2011/09/androids-http-clients.html

LINQ: Select an object and change some properties without creating a new object

If you want to update items with a Where clause, using a .Where(...) will truncate your results if you do:

mylist = mylist.Where(n => n.Id == ID).Select(n => { n.Property = ""; return n; }).ToList();

You can do updates to specific item(s) in the list like so:

mylist = mylist.Select(n => { if (n.Id == ID) { n.Property = ""; } return n; }).ToList();

Always return item even if you don't make any changes. This way it will be kept in the list.

In a Git repository, how to properly rename a directory?

I solved it in two steps. To rename folder using mv command you need rights to do so, if you don't have right you can follow these steps. Suppose you want to rename casesensitive to Casesensitive.

Step 1: Rename the folder (casesensitive) to something else from explorer. eg Rename casesensitive to folder1 commit this change.

Step 2: Rename this newly named folder(folder1) to the expected case sensitive name (Casesensitive ) eg. Rename folder1 to Casesensitive. Commit this change.

JCheckbox - ActionListener and ItemListener?

Both ItemListener as well as ActionListener, in case of JCheckBox have the same behaviour. However, major difference is ItemListener can be triggered by calling the setSelected(true) on the checkbox. As a coding practice do not register both ItemListener as well as ActionListener with the JCheckBox, in order to avoid inconsistency.

Closing Excel Application using VBA

Sub button2_click()
'
' Button2_Click Macro
'
' Keyboard Shortcut: Ctrl+Shift+Q
'
    ActiveSheet.Shapes("Button 2").Select
    Selection.Characters.Text = "Logout"
    ActiveSheet.Shapes("Button 2").Select
    Selection.OnAction = "Button2_Click"
    ActiveWorkbook.Saved = True
    ActiveWorkbook.Save
    Application.Quit
End Sub

How to enumerate a range of numbers starting at 1

Just to put this here for posterity sake, in 2.6 the "start" parameter was added to enumerate like so:

enumerate(sequence, start=1)

How do I specify the exit code of a console application in .NET?

The enumeration option is excellent however can be improved upon by multiplying the numbers as in:

enum ExitCodes : int
{
  Success = 0,
  SignToolNotInPath = 1,
  AssemblyDirectoryBad = 2,
  PFXFilePathBad = 4,
  PasswordMissing = 8,
  SignFailed = 16,
  UnknownError = 32
}

In the case of multiple errors, adding the specific error numbers together will give you a unique number that will represent the combination of detected errors.

For example, an errorlevel of 6 can only consist of errors 4 and 2, 12 can only consist of errors 4 and 8, 14 can only consist of 2, 4 and 8 etc.

What is PAGEIOLATCH_SH wait type in SQL Server?

From Microsoft documentation:

PAGEIOLATCH_SH

Occurs when a task is waiting on a latch for a buffer that is in an I/O request. The latch request is in Shared mode. Long waits may indicate problems with the disk subsystem.

In practice, this almost always happens due to large scans over big tables. It almost never happens in queries that use indexes efficiently.

If your query is like this:

Select * from <table> where <col1> = <value> order by <PrimaryKey>

, check that you have a composite index on (col1, col_primary_key).

If you don't have one, then you'll need either a full INDEX SCAN if the PRIMARY KEY is chosen, or a SORT if an index on col1 is chosen.

Both of them are very disk I/O consuming operations on large tables.

Multiple INSERT statements vs. single INSERT with multiple VALUES

The issue probably has to do with the time it takes to compile the query.

If you want to speed up the inserts, what you really need to do is wrap them in a transaction:

BEGIN TRAN;
INSERT INTO T_TESTS (TestId, FirstName, LastName, Age) 
   VALUES ('6f3f7257-a3d8-4a78-b2e1-c9b767cfe1c1', 'First 0', 'Last 0', 0);
INSERT INTO T_TESTS (TestId, FirstName, LastName, Age) 
   VALUES ('32023304-2e55-4768-8e52-1ba589b82c8b', 'First 1', 'Last 1', 1);
...
INSERT INTO T_TESTS (TestId, FirstName, LastName, Age) 
   VALUES ('f34d95a7-90b1-4558-be10-6ceacd53e4c4', 'First 999', 'Last 999', 999);
COMMIT TRAN;

From C#, you might also consider using a table valued parameter. Issuing multiple commands in a single batch, by separating them with semicolons, is another approach that will also help.

What is the standard naming convention for html/css ids and classes?

There isn't one.

I use underscores all the time, due to hyphens messing up the syntax highlighting of my text editor (Gedit), but that's personal preference.

I've seen all these conventions used all over the place. Use the one that you think is best - the one that looks nicest/easiest to read for you, as well as easiest to type because you'll be using it a lot. For example, if you've got your underscore key on the underside of the keyboard (unlikely, but entirely possible), then stick to hyphens. Just go with what is best for yourself. Additionally, all 3 of these conventions are easily readable. If you're working in a team, remember to keep with the team-specified convention (if any).

Update 2012

I've changed how I program over time. I now use camel case (thisIsASelector) instead of hyphens now; I find the latter rather ugly. Use whatever you prefer, which may easily change over time.

Update 2013

It looks like I like to mix things up yearly... After switching to Sublime Text and using Bootstrap for a while, I've gone back to dashes. To me now they look a lot cleaner than un_der_scores or camelCase. My original point still stands though: there isn't a standard.

Update 2015

An interesting corner case with conventions here is Rust. I really like the language, but the compiler will warn you if you define stuff using anything other than underscore_case. You can turn the warning off, but it's interesting the compiler strongly suggests a convention by default. I imagine in larger projects it leads to cleaner code which is no bad thing.

Update 2016 (you asked for it)

I've adopted the BEM standard for my projects going forward. The class names end up being quite verbose, but I think it gives good structure and reusability to the classes and CSS that goes with them. I suppose BEM is actually a standard (so my no becomes a yes perhaps) but it's still up to you what you decide to use in a project. Most importantly: be consistent with what you choose.

Update 2019 (you asked for it)

After writing no CSS for quite a while, I started working at a place that uses OOCSS in one of their products. I personally find it pretty unpleasant to litter classes everywhere, but not having to jump between HTML and CSS all the time feels quite productive.

I'm still settled on BEM, though. It's verbose, but the namespacing makes working with it in React components very natural. It's also great for selecting specific elements when browser testing.

OOCSS and BEM are just some of the CSS standards out there. Pick one that works for you - they're all full of compromises because CSS just isn't that good.

Update 2020

A boring update this year. I'm still using BEM. My position hasn't really changed from the 2019 update for the reasons listed above. Use what works for you that scales with your team size and hides as much or as little of CSS' poor featureset as you like.

Kubernetes service external ip pending

If you are using minikube then run commands below from terminal,

$ minikube ip
$ 172.17.0.2 // then 
$ curl http://172.17.0.2:31245
or simply
$ curl http://$(minikube ip):31245

Convert all data frame character columns to factors

I used to do a simple for loop. As @A5C1D2H2I1M1N2O1R2T1 answer, lapply is a nice solution. But if you convert all the columns, you will need a data.frame before, otherwise you will end up with a list. Little execution time differences.

 mm2N=mm2New[,10:18]
 str(mm2N)
'data.frame':   35487 obs. of  9 variables:
 $ bb    : int  4 6 2 3 3 2 5 2 1 2 ...
 $ vabb  : int  -3 -3 -2 -2 -3 -1 0 0 3 3 ...
 $ bb55  : int  7 6 3 4 4 4 9 2 5 4 ...
 $ vabb55: int  -3 -1 0 -1 -2 -2 -3 0 -1 3 ...
 $ zr    : num  0 -2 -1 1 -1 -1 -1 1 1 0 ...
 $ z55r  : num  -2 -2 0 1 -2 -2 -2 1 -1 1 ...
 $ fechar: num  0 -1 1 0 1 1 0 0 1 0 ...
 $ varr  : num  3 3 1 1 1 1 4 1 1 3 ...
 $ minmax: int  3 0 4 6 6 6 0 6 6 1 ...

 # For solution
 t1=Sys.time()
 for(i in 1:ncol(mm2N)) mm2N[,i]=as.factor(mm2N[,i])
 Sys.time()-t1
Time difference of 0.2020121 secs
 str(mm2N)
'data.frame':   35487 obs. of  9 variables:
 $ bb    : Factor w/ 6 levels "1","2","3","4",..: 4 6 2 3 3 2 5 2 1 2 ...
 $ vabb  : Factor w/ 7 levels "-3","-2","-1",..: 1 1 2 2 1 3 4 4 7 7 ...
 $ bb55  : Factor w/ 8 levels "2","3","4","5",..: 6 5 2 3 3 3 8 1 4 3 ...
 $ vabb55: Factor w/ 7 levels "-3","-2","-1",..: 1 3 4 3 2 2 1 4 3 7 ...
 $ zr    : Factor w/ 5 levels "-2","-1","0",..: 3 1 2 4 2 2 2 4 4 3 ...
 $ z55r  : Factor w/ 5 levels "-2","-1","0",..: 1 1 3 4 1 1 1 4 2 4 ...
 $ fechar: Factor w/ 3 levels "-1","0","1": 2 1 3 2 3 3 2 2 3 2 ...
 $ varr  : Factor w/ 5 levels "1","2","3","4",..: 3 3 1 1 1 1 4 1 1 3 ...
 $ minmax: Factor w/ 7 levels "0","1","2","3",..: 4 1 5 7 7 7 1 7 7 2 ...

 #lapply solution
 mm2N=mm2New[,10:18]
 t1=Sys.time()
 mm2N <- lapply(mm2N, as.factor)
 Sys.time()-t1
Time difference of 0.209012 secs
 str(mm2N)
List of 9
 $ bb    : Factor w/ 6 levels "1","2","3","4",..: 4 6 2 3 3 2 5 2 1 2 ...
 $ vabb  : Factor w/ 7 levels "-3","-2","-1",..: 1 1 2 2 1 3 4 4 7 7 ...
 $ bb55  : Factor w/ 8 levels "2","3","4","5",..: 6 5 2 3 3 3 8 1 4 3 ...
 $ vabb55: Factor w/ 7 levels "-3","-2","-1",..: 1 3 4 3 2 2 1 4 3 7 ...
 $ zr    : Factor w/ 5 levels "-2","-1","0",..: 3 1 2 4 2 2 2 4 4 3 ...
 $ z55r  : Factor w/ 5 levels "-2","-1","0",..: 1 1 3 4 1 1 1 4 2 4 ...
 $ fechar: Factor w/ 3 levels "-1","0","1": 2 1 3 2 3 3 2 2 3 2 ...
 $ varr  : Factor w/ 5 levels "1","2","3","4",..: 3 3 1 1 1 1 4 1 1 3 ...
 $ minmax: Factor w/ 7 levels "0","1","2","3",..: 4 1 5 7 7 7 1 7 7 2 ...

 #data.frame lapply solution
 mm2N=mm2New[,10:18]
 t1=Sys.time()
 mm2N <- data.frame(lapply(mm2N, as.factor))
 Sys.time()-t1
Time difference of 0.2010119 secs
 str(mm2N)
'data.frame':   35487 obs. of  9 variables:
 $ bb    : Factor w/ 6 levels "1","2","3","4",..: 4 6 2 3 3 2 5 2 1 2 ...
 $ vabb  : Factor w/ 7 levels "-3","-2","-1",..: 1 1 2 2 1 3 4 4 7 7 ...
 $ bb55  : Factor w/ 8 levels "2","3","4","5",..: 6 5 2 3 3 3 8 1 4 3 ...
 $ vabb55: Factor w/ 7 levels "-3","-2","-1",..: 1 3 4 3 2 2 1 4 3 7 ...
 $ zr    : Factor w/ 5 levels "-2","-1","0",..: 3 1 2 4 2 2 2 4 4 3 ...
 $ z55r  : Factor w/ 5 levels "-2","-1","0",..: 1 1 3 4 1 1 1 4 2 4 ...
 $ fechar: Factor w/ 3 levels "-1","0","1": 2 1 3 2 3 3 2 2 3 2 ...
 $ varr  : Factor w/ 5 levels "1","2","3","4",..: 3 3 1 1 1 1 4 1 1 3 ...
 $ minmax: Factor w/ 7 levels "0","1","2","3",..: 4 1 5 7 7 7 1 7 7 2 ...

Using IF ELSE statement based on Count to execute different Insert statements

If this is in SQL Server, your syntax is correct; however, you need to reference the COUNT(*) as the Total Count from your nested query. This should give you what you need:

SELECT CASE WHEN TotalCount >0 THEN 'TRUE' ELSE 'FALSE' END FROM
(
  SELECT [Some Column], COUNT(*) TotalCount
  FROM INCIDENTS
  WHERE [Some Column] = 'Target Data'
  GROUP BY [Some Column]
) DerivedTable

Using this, you could assign TotalCount to a variable and then use an IF ELSE statement to execute your INSERT statements:

DECLARE @TotalCount int
SELECT @TotalCount = TotalCount FROM
(
  SELECT [Some Column], COUNT(*) TotalCount
  FROM INCIDENTS
  WHERE [Some Column] = 'Target Data'
  GROUP BY [Some Column]
) DerivedTable
IF @TotalCount > 0
    -- INSERT STATEMENT 1 GOES HERE
ELSE
    -- INSERT STATEMENT 2 GOES HERE

Excel how to find values in 1 column exist in the range of values in another

Use the formula by tigeravatar:

=COUNTIF($B$2:$B$5,A2)>0 – tigeravatar Aug 28 '13 at 14:50

as conditional formatting. Highlight column A. Choose conditional formatting by forumula. Enter the formula (above) - this finds values in col B that are also in A. Choose a format (I like to use FILL and a bold color).

To find all of those values, highlight col A. Data > Filter and choose Filter by color.

How to find out if an item is present in a std::vector?

With boost you can use any_of_equal:

#include <boost/algorithm/cxx11/any_of.hpp>

bool item_present = boost::algorithm::any_of_equal(vector, element);

Calculate the number of business days between two dates?

Works and without loops

This method doesn't use any loops and is actually quite simple. It expands the date range to full weeks since we know that each week has 5 business days. It then uses a lookup table to find the number of business days to subtract from the start and end to get the right result. I've expanded out the calculation to help show what's going on, but the whole thing could be condensed into a single line if needed.

Anyway, this works for me and so I thought I'd post it here in case it might help others. Happy coding.

Calculation

  • t : Total number of days between dates (1 if min = max)
  • a + b : Extra days needed to expand total to full weeks
  • k : 1.4 is number of weekdays per week, i.e., (t / 7) * 5
  • c : Number of weekdays to subtract from the total
  • m : A lookup table used to find the value of "c" for each day of the week

Culture

Code assumes a Monday to Friday work week. For other cultures, such as Sunday to Thursday, you'll need to offset the dates prior to calculation.

Method

public int Weekdays(DateTime min, DateTime max) 
{       
        if (min.Date > max.Date) throw new Exception("Invalid date span");
        var t = (max.AddDays(1).Date - min.Date).TotalDays;
        var a = (int) min.DayOfWeek;
        var b = 6 - (int) max.DayOfWeek;
        var k = 1.4;
        var m = new int[]{0, 0, 1, 2, 3, 4, 5}; 
        var c = m[a] + m[b];
        return (int)((t + a + b) / k) - c;
}

How to create an HTTPS server in Node.js?

Found this question while googling "node https" but the example in the accepted answer is very old - taken from the docs of the current (v0.10) version of node, it should look like this:

var https = require('https');
var fs = require('fs');

var options = {
  key: fs.readFileSync('test/fixtures/keys/agent2-key.pem'),
  cert: fs.readFileSync('test/fixtures/keys/agent2-cert.pem')
};

https.createServer(options, function (req, res) {
  res.writeHead(200);
  res.end("hello world\n");
}).listen(8000);

SPAN vs DIV (inline-block)

I think it will help you to understand the basic differences between Inline-Elements (e.g. span) and Block-Elements (e.g. div), in order to understand why "display: inline-block" is so useful.

Problem: inline elements (e.g. span, a, button, input etc.) take "margin" only horizontally (margin-left and margin-right) on, not vertically. Vertical spacing works only on block elements (or if "display:block" is set)

Solution: Only through "display: inline-block" will also take the vertical distance (top and bottom). Reason: Inline element Span, behaves now like a block element to the outside, but like an inline element inside

Here Code Examples:

_x000D_
_x000D_
 /* Inlineelement */

        div,
        span {
            margin: 30px;
        }

        span {
            outline: firebrick dotted medium;
            background-color: antiquewhite;
        }

        span.mitDisplayBlock {
            background: #a2a2a2;
            display: block;
            width: 200px;
            height: 200px;
        }

        span.beispielMargin {
            margin: 20px;
        }

        span.beispielMarginDisplayInlineBlock {
            display: inline-block;
        }

        span.beispielMarginDisplayInline {
            display: inline;
        }

        span.beispielMarginDisplayBlock {
            display: block;
        }

        /* Blockelement */

        div {
            outline: orange dotted medium;
            background-color: deepskyblue;
        }

        .paddingDiv {
            padding: 20px;
            background-color: blanchedalmond;
        }

        .marginDivWrapper {
            background-color: aliceblue;

        }

        .marginDiv {
            margin: 20px;
            background-color: blanchedalmond;
        }
    </style>
    <style>
        /* Nur für das w3school Bild */

        #w3_DIV_1 {
            bottom: 0px;
            box-sizing: border-box;
            height: 391px;
            left: 0px;
            position: relative;
            right: 0px;
            text-size-adjust: 100%;
            top: 0px;
            width: 913.984px;
            perspective-origin: 456.984px 195.5px;
            transform-origin: 456.984px 195.5px;
            background: rgb(241, 241, 241) none repeat scroll 0% 0% / auto padding-box border-box;
            border: 2px dashed rgb(187, 187, 187);
            font: normal normal 400 normal 15px / 22.5px Lato, sans-serif;
            padding: 45px;
            transition: all 0.25s ease-in-out 0s;
        }

        /*#w3_DIV_1*/

        #w3_DIV_1:before {
            bottom: 349.047px;
            box-sizing: border-box;
            content: '"Margin"';
            display: block;
            height: 31px;
            left: 0px;
            position: absolute;
            right: 0px;
            text-align: center;
            text-size-adjust: 100%;
            top: 6.95312px;
            width: 909.984px;
            perspective-origin: 454.984px 15.5px;
            transform-origin: 454.984px 15.5px;
            font: normal normal 400 normal 21px / 31.5px Lato, sans-serif;
        }

        /*#w3_DIV_1:before*/

        #w3_DIV_2 {
            bottom: 0px;
            box-sizing: border-box;
            color: black;
            height: 297px;
            left: 0px;
            position: relative;
            right: 0px;
            text-decoration: none solid rgb(255, 255, 255);
            text-size-adjust: 100%;
            top: 0px;
            width: 819.984px;
            column-rule-color: rgb(255, 255, 255);
            perspective-origin: 409.984px 148.5px;
            transform-origin: 409.984px 148.5px;
            caret-color: rgb(255, 255, 255);
            background: rgb(76, 175, 80) none repeat scroll 0% 0% / auto padding-box border-box;
            border: 0px none rgb(255, 255, 255);
            font: normal normal 400 normal 15px / 22.5px Lato, sans-serif;
            outline: rgb(255, 255, 255) none 0px;
            padding: 45px;
        }

        /*#w3_DIV_2*/

        #w3_DIV_2:before {
            bottom: 258.578px;
            box-sizing: border-box;
            content: '"Border"';
            display: block;
            height: 31px;
            left: 0px;
            position: absolute;
            right: 0px;
            text-align: center;
            text-size-adjust: 100%;
            top: 7.42188px;
            width: 819.984px;
            perspective-origin: 409.984px 15.5px;
            transform-origin: 409.984px 15.5px;
            font: normal normal 400 normal 21px / 31.5px Lato, sans-serif;
        }

        /*#w3_DIV_2:before*/

        #w3_DIV_3 {
            bottom: 0px;
            box-sizing: border-box;
            height: 207px;
            left: 0px;
            position: relative;
            right: 0px;
            text-size-adjust: 100%;
            top: 0px;
            width: 729.984px;
            perspective-origin: 364.984px 103.5px;
            transform-origin: 364.984px 103.5px;
            background: rgb(241, 241, 241) none repeat scroll 0% 0% / auto padding-box border-box;
            font: normal normal 400 normal 15px / 22.5px Lato, sans-serif;
            padding: 45px;
        }

        /*#w3_DIV_3*/

        #w3_DIV_3:before {
            bottom: 168.344px;
            box-sizing: border-box;
            content: '"Padding"';
            display: block;
            height: 31px;
            left: 3.64062px;
            position: absolute;
            right: -3.64062px;
            text-align: center;
            text-size-adjust: 100%;
            top: 7.65625px;
            width: 729.984px;
            perspective-origin: 364.984px 15.5px;
            transform-origin: 364.984px 15.5px;
            font: normal normal 400 normal 21px / 31.5px Lato, sans-serif;
        }

        /*#w3_DIV_3:before*/

        #w3_DIV_4 {
            bottom: 0px;
            box-sizing: border-box;
            height: 117px;
            left: 0px;
            position: relative;
            right: 0px;
            text-size-adjust: 100%;
            top: 0px;
            width: 639.984px;
            perspective-origin: 319.984px 58.5px;
            transform-origin: 319.984px 58.5px;
            background: rgb(191, 201, 101) none repeat scroll 0% 0% / auto padding-box border-box;
            border: 2px dashed rgb(187, 187, 187);
            font: normal normal 400 normal 15px / 22.5px Lato, sans-serif;
            padding: 20px;
        }

        /*#w3_DIV_4*/

        #w3_DIV_4:before {
            box-sizing: border-box;
            content: '"Content"';
            display: block;
            height: 73px;
            text-align: center;
            text-size-adjust: 100%;
            width: 595.984px;
            perspective-origin: 297.984px 36.5px;
            transform-origin: 297.984px 36.5px;
            font: normal normal 400 normal 21px / 73.5px Lato, sans-serif;
        }

        /*#w3_DIV_4:before*/
_x000D_
   <h1> The Box model - content, padding, border, margin</h1>
    <h2> Inline element - span</h2>
    <span>Info: A span element can not have height and width (not without "display: block"), which means it takes the fixed inline size </span>

    <span class="beispielMargin">
        <b>Problem:</b> inline elements (eg span, a, button, input etc.) take "margin" only vertically (margin-left and margin-right)
        on, not horizontal. Vertical spacing works only on block elements (or if display: block is set) </span>

    <span class="beispielMarginDisplayInlineBlock">
        <b>Solution</b> Only through
        <b> "display: inline-block" </ b> will also take the vertical distance (top and bottom). Reason: Inline element Span,
        behaves now like a block element to the outside, but like an inline element inside</span>

    <span class="beispielMarginDisplayInline">Example: here "display: inline". See the margin with Inspector!</span>

    <span class="beispielMarginDisplayBlock">Example: here "display: block". See the margin with Inspector!</span>

    <span class="beispielMarginDisplayInlineBlock">Example: here "display: inline-block". See the margin with Inspector! </span>

    <span class="mitDisplayBlock">Only with the "Display" -property and "block" -Value in addition, a width and height can be assigned. "span" is then like
        a "div" block element.  </span>

    <h2>Inline-Element - Div</h2>
    <div> A div automatically takes "display: block." </ div>
    <div class = "paddingDiv"> Padding is for padding </ div>

    <div class="marginDivWrapper">
Wrapper encapsulates the example "marginDiv" to clarify the "margin" (distance from inner element "marginDiv" to the text)
        of the outer element "marginDivWrapper". Here 20px;)
        
    <div class = "marginDiv"> margin is for the margins </ div>
        And there, too, 20px;
    </div>

    <h2>w3school sample image </h2>
    source:
    <a href="https://www.w3schools.com/css/css_boxmodel.asp">CSS Box Model</a>
    <div id="w3_DIV_1">
        <div id="w3_DIV_2">
            <div id="w3_DIV_3">
                <div id="w3_DIV_4">
                </div>
            </div>
        </div>
    </div>
_x000D_
_x000D_
_x000D_

Angular and debounce

Solution with initialization subscriber directly in event function:

import {Subject} from 'rxjs';
import {debounceTime, distinctUntilChanged} from 'rxjs/operators';

class MyAppComponent {
    searchTermChanged: Subject<string> = new Subject<string>();

    constructor() {
    }

    onFind(event: any) {
        if (this.searchTermChanged.observers.length === 0) {
            this.searchTermChanged.pipe(debounceTime(1000), distinctUntilChanged())
                .subscribe(term => {
                    // your code here
                    console.log(term);
                });
        }
        this.searchTermChanged.next(event);
    }
}

And html:

<input type="text" (input)="onFind($event.target.value)">

Preloading @font-face fonts?

Recently I was working on a game compatible with CocoonJS with DOM limited to the canvas element - here is my approach:

Using fillText with a font that has not been loaded yet will execute properly but with no visual feedback - so the canvas plane will stay intact - all you have to do is periodically check the canvas for any changes (for example looping through getImageData searching for any non transparent pixel) that will happen when the font loads properly.

I have explained this technique a little bit more in my recent article http://rezoner.net/preloading-font-face-using-canvas,686

Using HTML5/Canvas/JavaScript to take in-browser screenshots

Get screenshot as Canvas or Jpeg Blob / ArrayBuffer using getDisplayMedia API:

FIX 1: Use the getUserMedia with chromeMediaSource only for Electron.js
FIX 2: Throw error instead return null object
FIX 3: Fix demo to prevent the error: getDisplayMedia must be called from a user gesture handler

// docs: https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getDisplayMedia
// see: https://www.webrtc-experiment.com/Pluginfree-Screen-Sharing/#20893521368186473
// see: https://github.com/muaz-khan/WebRTC-Experiment/blob/master/Pluginfree-Screen-Sharing/conference.js

function getDisplayMedia(options) {
    if (navigator.mediaDevices && navigator.mediaDevices.getDisplayMedia) {
        return navigator.mediaDevices.getDisplayMedia(options)
    }
    if (navigator.getDisplayMedia) {
        return navigator.getDisplayMedia(options)
    }
    if (navigator.webkitGetDisplayMedia) {
        return navigator.webkitGetDisplayMedia(options)
    }
    if (navigator.mozGetDisplayMedia) {
        return navigator.mozGetDisplayMedia(options)
    }
    throw new Error('getDisplayMedia is not defined')
}

function getUserMedia(options) {
    if (navigator.mediaDevices && navigator.mediaDevices.getUserMedia) {
        return navigator.mediaDevices.getUserMedia(options)
    }
    if (navigator.getUserMedia) {
        return navigator.getUserMedia(options)
    }
    if (navigator.webkitGetUserMedia) {
        return navigator.webkitGetUserMedia(options)
    }
    if (navigator.mozGetUserMedia) {
        return navigator.mozGetUserMedia(options)
    }
    throw new Error('getUserMedia is not defined')
}

async function takeScreenshotStream() {
    // see: https://developer.mozilla.org/en-US/docs/Web/API/Window/screen
    const width = screen.width * (window.devicePixelRatio || 1)
    const height = screen.height * (window.devicePixelRatio || 1)

    const errors = []
    let stream
    try {
        stream = await getDisplayMedia({
            audio: false,
            // see: https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamConstraints/video
            video: {
                width,
                height,
                frameRate: 1,
            },
        })
    } catch (ex) {
        errors.push(ex)
    }

    // for electron js
    if (navigator.userAgent.indexOf('Electron') >= 0) {
        try {
            stream = await getUserMedia({
                audio: false,
                video: {
                    mandatory: {
                        chromeMediaSource: 'desktop',
                        // chromeMediaSourceId: source.id,
                        minWidth         : width,
                        maxWidth         : width,
                        minHeight        : height,
                        maxHeight        : height,
                    },
                },
            })
        } catch (ex) {
            errors.push(ex)
        }
    }

    if (errors.length) {
        console.debug(...errors)
        if (!stream) {
            throw errors[errors.length - 1]
        }
    }

    return stream
}

async function takeScreenshotCanvas() {
    const stream = await takeScreenshotStream()

    // from: https://stackoverflow.com/a/57665309/5221762
    const video = document.createElement('video')
    const result = await new Promise((resolve, reject) => {
        video.onloadedmetadata = () => {
            video.play()
            video.pause()

            // from: https://github.com/kasprownik/electron-screencapture/blob/master/index.js
            const canvas = document.createElement('canvas')
            canvas.width = video.videoWidth
            canvas.height = video.videoHeight
            const context = canvas.getContext('2d')
            // see: https://developer.mozilla.org/en-US/docs/Web/API/HTMLVideoElement
            context.drawImage(video, 0, 0, video.videoWidth, video.videoHeight)
            resolve(canvas)
        }
        video.srcObject = stream
    })

    stream.getTracks().forEach(function (track) {
        track.stop()
    })
    
    if (result == null) {
        throw new Error('Cannot take canvas screenshot')
    }

    return result
}

// from: https://stackoverflow.com/a/46182044/5221762
function getJpegBlob(canvas) {
    return new Promise((resolve, reject) => {
        // docs: https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement/toBlob
        canvas.toBlob(blob => resolve(blob), 'image/jpeg', 0.95)
    })
}

async function getJpegBytes(canvas) {
    const blob = await getJpegBlob(canvas)
    return new Promise((resolve, reject) => {
        const fileReader = new FileReader()

        fileReader.addEventListener('loadend', function () {
            if (this.error) {
                reject(this.error)
                return
            }
            resolve(this.result)
        })

        fileReader.readAsArrayBuffer(blob)
    })
}

async function takeScreenshotJpegBlob() {
    const canvas = await takeScreenshotCanvas()
    return getJpegBlob(canvas)
}

async function takeScreenshotJpegBytes() {
    const canvas = await takeScreenshotCanvas()
    return getJpegBytes(canvas)
}

function blobToCanvas(blob, maxWidth, maxHeight) {
    return new Promise((resolve, reject) => {
        const img = new Image()
        img.onload = function () {
            const canvas = document.createElement('canvas')
            const scale = Math.min(
                1,
                maxWidth ? maxWidth / img.width : 1,
                maxHeight ? maxHeight / img.height : 1,
            )
            canvas.width = img.width * scale
            canvas.height = img.height * scale
            const ctx = canvas.getContext('2d')
            ctx.drawImage(img, 0, 0, img.width, img.height, 0, 0, canvas.width, canvas.height)
            resolve(canvas)
        }
        img.onerror = () => {
            reject(new Error('Error load blob to Image'))
        }
        img.src = URL.createObjectURL(blob)
    })
}

DEMO:

document.body.onclick = async () => {
    // take the screenshot
    var screenshotJpegBlob = await takeScreenshotJpegBlob()

    // show preview with max size 300 x 300 px
    var previewCanvas = await blobToCanvas(screenshotJpegBlob, 300, 300)
    previewCanvas.style.position = 'fixed'
    document.body.appendChild(previewCanvas)

    // send it to the server
    var formdata = new FormData()
    formdata.append("screenshot", screenshotJpegBlob)
    await fetch('https://your-web-site.com/', {
        method: 'POST',
        body: formdata,
        'Content-Type' : "multipart/form-data",
    })
}

// and click on the page

Where and why do I have to put the "template" and "typename" keywords?

C++11

Problem

While the rules in C++03 about when you need typename and template are largely reasonable, there is one annoying disadvantage of its formulation

template<typename T>
struct A {
  typedef int result_type;

  void f() {
    // error, "this" is dependent, "template" keyword needed
    this->g<float>();

    // OK
    g<float>();

    // error, "A<T>" is dependent, "typename" keyword needed
    A<T>::result_type n1;

    // OK
    result_type n2; 
  }

  template<typename U>
  void g();
};

As can be seen, we need the disambiguation keyword even if the compiler could perfectly figure out itself that A::result_type can only be int (and is hence a type), and this->g can only be the member template g declared later (even if A is explicitly specialized somewhere, that would not affect the code within that template, so its meaning cannot be affected by a later specialization of A!).

Current instantiation

To improve the situation, in C++11 the language tracks when a type refers to the enclosing template. To know that, the type must have been formed by using a certain form of name, which is its own name (in the above, A, A<T>, ::A<T>). A type referenced by such a name is known to be the current instantiation. There may be multiple types that are all the current instantiation if the type from which the name is formed is a member/nested class (then, A::NestedClass and A are both current instantiations).

Based on this notion, the language says that CurrentInstantiation::Foo, Foo and CurrentInstantiationTyped->Foo (such as A *a = this; a->Foo) are all member of the current instantiation if they are found to be members of a class that is the current instantiation or one of its non-dependent base classes (by just doing the name lookup immediately).

The keywords typename and template are now not required anymore if the qualifier is a member of the current instantiation. A keypoint here to remember is that A<T> is still a type-dependent name (after all T is also type dependent). But A<T>::result_type is known to be a type - the compiler will "magically" look into this kind of dependent types to figure this out.

struct B {
  typedef int result_type;
};

template<typename T>
struct C { }; // could be specialized!

template<typename T>
struct D : B, C<T> {
  void f() {
    // OK, member of current instantiation!
    // A::result_type is not dependent: int
    D::result_type r1;

    // error, not a member of the current instantiation
    D::questionable_type r2;

    // OK for now - relying on C<T> to provide it
    // But not a member of the current instantiation
    typename D::questionable_type r3;        
  }
};

That's impressive, but can we do better? The language even goes further and requires that an implementation again looks up D::result_type when instantiating D::f (even if it found its meaning already at definition time). When now the lookup result differs or results in ambiguity, the program is ill-formed and a diagnostic must be given. Imagine what happens if we defined C like this

template<>
struct C<int> {
  typedef bool result_type;
  typedef int questionable_type;
};

A compiler is required to catch the error when instantiating D<int>::f. So you get the best of the two worlds: "Delayed" lookup protecting you if you could get in trouble with dependent base classes, and also "Immediate" lookup that frees you from typename and template.

Unknown specializations

In the code of D, the name typename D::questionable_type is not a member of the current instantiation. Instead the language marks it as a member of an unknown specialization. In particular, this is always the case when you are doing DependentTypeName::Foo or DependentTypedName->Foo and either the dependent type is not the current instantiation (in which case the compiler can give up and say "we will look later what Foo is) or it is the current instantiation and the name was not found in it or its non-dependent base classes and there are also dependent base classes.

Imagine what happens if we had a member function h within the above defined A class template

void h() {
  typename A<T>::questionable_type x;
}

In C++03, the language allowed to catch this error because there could never be a valid way to instantiate A<T>::h (whatever argument you give to T). In C++11, the language now has a further check to give more reason for compilers to implement this rule. Since A has no dependent base classes, and A declares no member questionable_type, the name A<T>::questionable_type is neither a member of the current instantiation nor a member of an unknown specialization. In that case, there should be no way that that code could validly compile at instantiation time, so the language forbids a name where the qualifier is the current instantiation to be neither a member of an unknown specialization nor a member of the current instantiation (however, this violation is still not required to be diagnosed).

Examples and trivia

You can try this knowledge on this answer and see whether the above definitions make sense for you on a real-world example (they are repeated slightly less detailed in that answer).

The C++11 rules make the following valid C++03 code ill-formed (which was not intended by the C++ committee, but will probably not be fixed)

struct B { void f(); };
struct A : virtual B { void f(); };

template<typename T>
struct C : virtual B, T {
  void g() { this->f(); }
};

int main() { 
  C<A> c; c.g(); 
}

This valid C++03 code would bind this->f to A::f at instantiation time and everything is fine. C++11 however immediately binds it to B::f and requires a double-check when instantiating, checking whether the lookup still matches. However when instantiating C<A>::g, the Dominance Rule applies and lookup will find A::f instead.

apache server reached MaxClients setting, consider raising the MaxClients setting

When you use Apache with mod_php apache is enforced in prefork mode, and not worker. As, even if php5 is known to support multi-thread, it is also known that some php5 libraries are not behaving very well in multithreaded environments (so you would have a locale call on one thread altering locale on other php threads, for example).

So, if php is not running in cgi way like with php-fpm you have mod_php inside apache and apache in prefork mode. On your tests you have simply commented the prefork settings and increased the worker settings, what you now have is default values for prefork settings and some altered values for the shared ones :

StartServers       20
MinSpareServers    5
MaxSpareServers    10
MaxClients         1024
MaxRequestsPerChild  0

This means you ask apache to start with 20 process, but you tell it that, if there is more than 10 process doing nothing it should reduce this number of children, to stay between 5 and 10 process available. The increase/decrease speed of apache is 1 per minute. So soon you will fall back to the classical situation where you have a fairly low number of free available apache processes (average 2). The average is low because usually you have something like 5 available process, but as soon as the traffic grows they're all used, so there's no process available as apache is very slow in creating new forks. This is certainly increased by the fact your PHP requests seems to be quite long, they do not finish early and the apache forks are not released soon enough to treat another request.

See on the last graphic the small amount of green before the red peak? If you could graph this on a 1 minute basis instead of 5 minutes you would see that this green amount was not big enough to take the incoming traffic without any error message.

Now you set 1024 MaxClients. I guess the cacti graph are not taken after this configuration modification, because with such modification, when no more process are available, apache would continue to fork new children, with a limit of 1024 busy children. Take something like 20MB of RAM per child (or maybe you have a big memory_limit in PHP and allows something like 64MB or 256MB and theses PHP requests are really using more RAM), maybe a DB server... your server is now slowing down because you have only 768MB of RAM. Maybe when apache is trying to initiate the first 20 children you already reach the available RAM limit.

So. a classical way of handling that is to check the amount of memory used by an apache fork (make some top commands while it is running), then find how many parallel request you can handle with this amount of RAM (that mean parallel apache children in prefork mode). Let's say it's 12, for example. Put this number in apache mpm settings this way:

<IfModule prefork.c>
  StartServers       12
  MinSpareServers    12
  MaxSpareServers    12
  MaxClients         12
  MaxRequestsPerChild  300
</IfModule>

That means you do not move the number of fork while traffic increase or decrease, because you always want to use all the RAM and be ready for traffic peaks. The 300 means you recyclate each fork after 300 requests, it's better than 0, it means you will not have potential memory leaks issues. MaxClients is set to 12 25 or 50 which is more than 12 to handle the ListenBacklog queue, which can enqueue some requests, you may take a bigger queue, but you would get some timeouts maybe (removed this strange sentende, I can't remember why I said that, if more than 12 requests are incoming the next one will be pushed in the Backlog queue, but you should set MaxClient to your targeted number of processes).

And yes, that means you cannot handle more than 12 parallel requests.

If you want to handle more requests:

  • buy some more RAM
  • try to use apache in worker mode, but remove mod_php and use php as a parallel daemon with his own pooler settings (this is called php-fpm), connect it with fastcgi. Note that you will certainly need to buy some RAM to allow a big number of parallel php-fpm process, but maybe less than with mod_php
  • Reduce the time spent in your php process. From your cacti graphs you have to potential problems: a real traffic peak around 11:25-11:30 or some php code getting very slow. Fast requests will reduce the number of parallel requests.

If your problem is really traffic peaks, solutions could be available with caches, like a proxy-cache server. If the problem is a random slowness in PHP then... it's an application problem, do you do some HTTP query to another site from PHP, for example?

And finally, as stated by @Jan Vlcinsky you could try nginx, where php will only be available as php-fpm. If you cannot buy RAM and must handle a big traffic that's definitively desserve a test.

Update: About internal dummy connections (if it's your problem, but maybe not).

Check this link and this previous answer. This is 'normal', but if you do not have a simple virtualhost theses requests are maybe hitting your main heavy application, generating slow http queries and preventing regular users to acces your apache processes. They are generated on graceful reload or children managment.

If you do not have a simple basic "It works" default Virtualhost prevent theses requests on your application by some rewrites:

  RewriteCond %{HTTP_USER_AGENT} ^.*internal\ dummy\ connection.*$ [NC]
  RewriteRule .* - [F,L]

Update:

Having only one Virtualhost does not protect you from internal dummy connections, it is worst, you are sure now that theses connections are made on your unique Virtualhost. So you should really avoid side effects on your application by using the rewrite rules.

Reading your cacti graphics, it seems your apache is not in prefork mode bug in worker mode. Run httpd -l or apache2 -l on debian, and check if you have worker.c or prefork.c. If you are in worker mode you may encounter some PHP problems in your application, but you should check the worker settings, here is an example:

<IfModule worker.c>
  StartServers           3
  MaxClients           500
  MinSpareThreads       75
  MaxSpareThreads      250 
  ThreadsPerChild       25
  MaxRequestsPerChild  300
</IfModule>

You start 3 processes, each containing 25 threads (so 3*25=75 parallel requests available by default), you allow 75 threads doing nothing, as soon as one thread is used a new process is forked, adding 25 more threads. And when you have more than 250 threads doing nothing (10 processes) some process are killed. You must adjust theses settings with your memory. Here you allow 500 parallel process (that's 20 process of 25 threads). Your usage is maybe more:

<IfModule worker.c>
  StartServers           2
  MaxClients           250
  MinSpareThreads       50
  MaxSpareThreads      150 
  ThreadsPerChild       25
  MaxRequestsPerChild  300
</IfModule>

IN-clause in HQL or Java Persistence Query Language

Are you using Hibernate's Query object, or JPA? For JPA, it should work fine:

String jpql = "from A where name in (:names)";
Query q = em.createQuery(jpql);
q.setParameter("names", l);

For Hibernate's, you'll need to use the setParameterList:

String hql = "from A where name in (:names)";
Query q = s.createQuery(hql);
q.setParameterList("names", l);

Sending Windows key using SendKeys

OK turns out what you really want is this: http://inputsimulator.codeplex.com/

Which has done all the hard work of exposing the Win32 SendInput methods to C#. This allows you to directly send the windows key. This is tested and works:

InputSimulator.SimulateModifiedKeyStroke(VirtualKeyCode.LWIN, VirtualKeyCode.VK_E);

Note however that in some cases you want to specifically send the key to the application (such as ALT+F4), in which case use the Form library method. In others, you want to send it to the OS in general, use the above.


Old

Keeping this here for reference, it will not work in all operating systems, and will not always behave how you want. Note that you're trying to send these key strokes to the app, and the OS usually intercepts them early. In the case of Windows 7 and Vista, too early (before the E is sent).

SendWait("^({ESC}E)") or Send("^({ESC}E)")

Note from here: http://msdn.microsoft.com/en-us/library/system.windows.forms.sendkeys.aspx

To specify that any combination of SHIFT, CTRL, and ALT should be held down while several other keys are pressed, enclose the code for those keys in parentheses. For example, to specify to hold down SHIFT while E and C are pressed, use "+(EC)". To specify to hold down SHIFT while E is pressed, followed by C without SHIFT, use "+EC".

Note that since you want ESC and (say) E pressed at the same time, you need to enclose them in brackets.

How to use HTTP.GET in AngularJS correctly? In specific, for an external API call?

So you need to use what we call promise. Read how angular handles it here, https://docs.angularjs.org/api/ng/service/$q. Turns our $http support promises inherently so in your case we'll do something like this,

(function() {
  "use strict";
  var serviceCallJson = function($http) {

      this.getCustomers = function() {
        // http method anyways returns promise so you can catch it in calling function
        return $http({
            method : 'get',
            url : '../viewersData/userPwdPair.json'
          });
      }

  }

  var validateIn = function (serviceCallJson, $q) {

      this.called = function(username, password) {
          var deferred = $q.defer(); 
          serviceCallJson.getCustomers().then( 
            function( returnedData ) {
              console.log(returnedData); // you should get output here this is a success handler
              var i = 0;
              angular.forEach(returnedData, function(value, key){
                while (i < 10) {
                  if(value[i].username == username) {
                    if(value[i].password == password) {
                     alert("Logged In");
                    }
                  }
                  i = i + 1;
                }
              });
            }, 
            function() {

              // this is error handler
            } 
          );
          return deferred.promise;  
      }

  }

  angular.module('assignment1App')
    .service ('serviceCallJson', serviceCallJson)

  angular.module('assignment1App')
  .service ('validateIn', ['serviceCallJson', validateIn])

}())

collapse cell in jupyter notebook

JupyterLab supports cell collapsing. Clicking on the blue cell bar on the left will fold the cell. enter image description here

How do I concatenate two arrays in C#?

Try the following:

T[] r1 = new T[size1];
T[] r2 = new T[size2];

List<T> targetList = new List<T>(r1);
targetList.Concat(r2);
T[] targetArray = targetList.ToArray();

How to make Visual Studio copy a DLL file to the output directory?

The details in the comments section above did not work for me (VS 2013) when trying to copy the output dll from one C++ project to the release and debug folder of another C# project within the same solution.

I had to add the following post build-action (right click on the project that has a .dll output) then properties -> configuration properties -> build events -> post-build event -> command line

now I added these two lines to copy the output dll into the two folders:

xcopy /y $(TargetPath) $(SolutionDir)aeiscontroller\bin\Release
xcopy /y $(TargetPath) $(SolutionDir)aeiscontroller\bin\Debug

Python os.path.join on Windows

answering to your comment : "the others '//' 'c:', 'c:\\' did not work (C:\\ created two backslashes, C:\ didn't work at all)"

On windows using os.path.join('c:', 'sourcedir') will automatically add two backslashes \\ in front of sourcedir.

To resolve the path, as python works on windows also with forward slashes -> '/', simply add .replace('\\','/') with os.path.join as below:-

os.path.join('c:\\', 'sourcedir').replace('\\','/')

e.g: os.path.join('c:\\', 'temp').replace('\\','/')

output : 'C:/temp'

Close Bootstrap Modal

I closed modal Programmatically with this trick

Add a button in modal with data-dismiss="modal" and hide the button with display: none. Here is how it will look like

<div class="modal fade" id="addNewPaymentMethod" role="dialog">
  <div class="modal-dialog">
   .
   .
   .
   <button type="button" id="close-modal" data-dismiss="modal" style="display: none">Close</button>
  </div>
</div>

Now when you want to close modal Programmatically just trigger a click event on that button, which is not visible to user

In Javascript you can trigger click on that button like this:

document.getElementById('close-modal').click();

Javascript to check whether a checkbox is being checked or unchecked

The value attribute of a checkbox is what you set by:

<input type='checkbox' name='test' value='1'>

So when someone checks that box, the server receives a variable named test with a value of 1 - what you want to check for is not the value of it (which will never change, whether it is checked or not) but the checked status of the checkbox.

So, if you replace this code:

if (arrChecks[i].value == "on") 
{
    arrChecks[i].checked = 1;
} else {
    arrChecks[i].checked = 0;
}

With this:

arrChecks[i].checked = !arrChecks[i].checked;

It should work. You should use true and false instead of 0 and 1 for this.

remove first element from array and return the array minus the first element

Why not use ES6?

_x000D_
_x000D_
 var myarray = ["item 1", "item 2", "item 3", "item 4"];_x000D_
 const [, ...rest] = myarray;_x000D_
 console.log(rest)
_x000D_
_x000D_
_x000D_

Drop a temporary table if it exists

From SQL Server 2016 you can just use

 DROP TABLE IF EXISTS ##CLIENTS_KEYWORD

On previous versions you can use

IF OBJECT_ID('tempdb..##CLIENTS_KEYWORD', 'U') IS NOT NULL
/*Then it exists*/
DROP TABLE ##CLIENTS_KEYWORD
CREATE TABLE ##CLIENTS_KEYWORD
(
   client_id INT
)

You could also consider truncating the table instead rather than dropping and recreating.

IF OBJECT_ID('tempdb..##CLIENTS_KEYWORD', 'U') IS NOT NULL
  TRUNCATE TABLE ##CLIENTS_KEYWORD
ELSE
  CREATE TABLE ##CLIENTS_KEYWORD
  (
     client_id INT
  ) 

How can I write a byte array to a file in Java?

To write a byte array to a file use the method

public void write(byte[] b) throws IOException

from BufferedOutputStream class.

java.io.BufferedOutputStream implements a buffered output stream. By setting up such an output stream, an application can write bytes to the underlying output stream without necessarily causing a call to the underlying system for each byte written.

For your example you need something like:

String filename= "C:/SO/SOBufferedOutputStreamAnswer";
BufferedOutputStream bos = null;
try {
//create an object of FileOutputStream
FileOutputStream fos = new FileOutputStream(new File(filename));

//create an object of BufferedOutputStream
bos = new BufferedOutputStream(fos);

KeyGenerator kgen = KeyGenerator.getInstance("AES"); 
kgen.init(128); 
SecretKey key = kgen.generateKey(); 
byte[] encoded = key.getEncoded();

bos.write(encoded);

} 
// catch and handle exceptions...

How to auto adjust the <div> height according to content in it?

I've used the following in the DIV that needs to be resized:

overflow: hidden;
height: 1%;

Check if a div exists with jquery

The first is the most concise, I would go with that. The first two are the same, but the first is just that little bit shorter, so you'll save on bytes. The third is plain wrong, because that condition will always evaluate true because the object will never be null or falsy for that matter.

How to insert values in two dimensional array programmatically?

Try to code below,

String[][] shades = new String[4][3];
for(int i = 0; i < 4; i++)
{
  for(int y = 0; y < 3; y++)
  {
    shades[i][y] = value;
  }
}

Filter dict to contain only certain keys?

We can do simply with lambda function like this:

>>> dict_filter = lambda x, y: dict([ (i,x[i]) for i in x if i in set(y) ])
>>> large_dict = {"a":1,"b":2,"c":3,"d":4}
>>> new_dict_keys = ("c","d")
>>> small_dict=dict_filter(large_dict, new_dict_keys)
>>> print(small_dict)
{'c': 3, 'd': 4}
>>> 

VB.NET Empty String Array

Something like:

Dim myArray(9) as String

Would give you an array of 10 String references (each pointing to Nothing).

If you're not sure of the size at declaration time, you can declare a String array like this:

Dim myArray() as String

And then you can point it at a properly-sized array of Strings later:

ReDim myArray(9) as String

ZombieSheep is right about using a List if you don't know the total size and you need to dynamically populate it. In VB.NET that would be:

Dim myList as New List(Of String)
myList.Add("foo")
myList.Add("bar")

And then to get an array from that List:

myList.ToArray()

@Mark

Thanks for the correction.

What causes and what are the differences between NoClassDefFoundError and ClassNotFoundException?

ClassNotFoundException and NoClassDefFoundError occur when a particular class is not found at runtime.However, they occur at different scenarios.

ClassNotFoundException is an exception that occurs when you try to load a class at run time using Class.forName() or loadClass() methods and mentioned classes are not found in the classpath.

    public class MainClass
    {
        public static void main(String[] args)
        {
            try
            {
                Class.forName("oracle.jdbc.driver.OracleDriver");
            }catch (ClassNotFoundException e)
            {
                e.printStackTrace();
            }
        }
    }



    java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Unknown Source)
    at pack1.MainClass.main(MainClass.java:17)

NoClassDefFoundError is an error that occurs when a particular class is present at compile time, but was missing at run time.

    class A
    {
      // some code
    }
    public class B
    {
        public static void main(String[] args)
        {
            A a = new A();
        }
    }

When you compile the above program, two .class files will be generated. One is A.class and another one is B.class. If you remove the A.class file and run the B.class file, Java Runtime System will throw NoClassDefFoundError like below:

    Exception in thread "main" java.lang.NoClassDefFoundError: A
    at MainClass.main(MainClass.java:10)
    Caused by: java.lang.ClassNotFoundException: A
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

How to display a content in two-column layout in LaTeX?

You can import a csv file to this website(https://www.tablesgenerator.com/latex_tables) and click copy to clipboard.

In Typescript, How to check if a string is Numeric

My simple solution here is:

const isNumeric = (val: string) : boolean => {
   return !isNaN(Number(val));
}

// isNumberic("2") => true
// isNumeric("hi") => false;

Entity Framework - Linq query with order by and group by

Try moving the order by after group by:

var groupByReference = (from m in context.Measurements
                        group m by new { m.Reference } into g
                        order by g.Avg(i => i.CreationTime)
                        select g).Take(numOfEntries).ToList();

How do I read image data from a URL in Python?

Python 3

from urllib.request import urlopen
from PIL import Image

img = Image.open(urlopen(url))
img

Jupyter Notebook and IPython

import IPython
url = 'https://newevolutiondesigns.com/images/freebies/colorful-background-14.jpg'
IPython.display.Image(url, width = 250)

Unlike other methods, this method also works in a for loop!

How do I ignore a directory with SVN?

After losing a lot of time looking for how to do this simple activity, I decided to post it was not hard to find a decent explanation.

First let the sample structure

$ svn st ? project/trunk/target ? project/trunk/myfile.x

1 – first configure the editor,in mycase vim export SVN_EDITOR=vim

2 – “svn propedit svn:ignore project/trunk/” will open a new file and you can add your files and subdirectory in us case type “target” save and close file and works

$ svn st ? project/trunk/myfile.x

thanks.

How to use SVG markers in Google Maps API v3

I know this post is a bit old, but I have seen so much bad information on this at SO that I could scream. So I just gotta throw my two cents in with a whole different approach that I know works, as I use it reliably on many maps. Besides that, I believe the OP wanted the ability to rotate the arrow marker around the map point as well, which is different than rotating the icon around it's own x,y axis which will change where the arrow marker points to on the map.

First, remember we are playing with Google maps and SVG, so we must accomodate the way in which Google deploys it's implementation of SVG for markers (or actually symbols). Google sets its anchor for the SVG marker image at 0,0 which IS NOT the upper left corner of the SVG viewBox. In order to get around this, you must draw your SVG image a bit differently to give Google what it wants... yes the answer is in the way you actually create the SVG path in your SVG editor (Illustrator, Inkscape, etc...).

The first step, is to get rid of the viewBox. This can be done by setting the viewBox in your XML to 0... that's right, just one zero instead of the usual four arguments for the viewBox. This turns the view box off (and yes, this is semantically correct). You will probably notice the size of your image jump immeadiately when you do this, and that is because the svg no longer has a base (the viewBox) to scale the image. So we create that reference directly, by setting the width and height to the actual number of pixels you wish your image to be in the XML editor of your SVG editor.

By setting the width and height of the svg image in the XML editor you create a baseline for scaling of the image, and this size becomes a value of 1 for the marker scale properties by default. You can see the advantage this has for dynamic scaling of the marker.

Now that you have your image sized, move the image until the part of the image you wish to have as the anchor is over the 0,0 coordinates of the svg editor. Once you have done this copy the value of the d attribute of the svg path. You will notice about half of the numbers are negative, which is the result of aligning your anchor point for the 0,0 of the image instead of the viewBox.

Using this technique will then let you rotate the marker correctly, around the lat and lng point on the map. This is the only reliable way to bind the point on the svg marker you want to the lat and long of the marker location.

I tried to make a JSFiddle for this, but there is some bug in there implementation, one of the reasons I am not so fond of reinterpreted code. So instead, I have included a fully self-contained example below that you can try out, adapt, and use as a reference. This is the same code I tried at JSFiddle that failed, yet it sails through Firebug without a whimper.

    <!DOCTYPE html>
    <html>
    <head>
    <meta charset="utf-8" />
    <meta name="viewport"  content="width=device-width, initial-scale=1" />
    <meta name="author"    content="Drew G. Stimson, Sr. ( Epiphany )" />
    <title>Create Draggable and Rotatable SVG Marker</title>
    <script src="http://maps.googleapis.com/maps/api/js?sensor=false"> </script>
    <style type="text/css">
      #document_body {
        margin:0;
        border: 0;
        padding: 10px;
        font-family: Arial,sans-serif;
        font-size: 14px;
        font-weight: bold;
        color: #f0f9f9;
        text-align: center;
        text-shadow: 1px 1px 1px #000;
        background:#1f1f1f;
      }
      #map_canvas, #rotation_control {
        margin: 1px;
        border:1px solid #000;
        background:#444;
        -webkit-border-radius: 4px;
           -moz-border-radius: 4px;
                border-radius: 4px;
      }
      #map_canvas { 
        width: 100%;
        height: 360px;
      }
      #rotation_control { 
        width: auto;
        padding:5px;
      }
      #rotation_value { 
        margin: 1px;
        border:1px solid #999;
        width: 60px;
        padding:2px;
        font-weight: bold;
        color: #00cc00;
        text-align: center;
        background:#111;
        border-radius: 4px;
      }
</style>

<script type="text/javascript">
  var map, arrow_marker, arrow_options;
  var map_center = {lat:41.0, lng:-103.0};
  var arrow_icon = {
    path: 'M -1.1500216e-4,0 C 0.281648,0 0.547084,-0.13447 0.718801,-0.36481 l 17.093151,-22.89064 c 0.125766,-0.16746 0.188044,-0.36854 0.188044,-0.56899 0,-0.19797 -0.06107,-0.39532 -0.182601,-0.56215 -0.245484,-0.33555 -0.678404,-0.46068 -1.057513,-0.30629 l -11.318243,4.60303 0,-26.97635 C 5.441639,-47.58228 5.035926,-48 4.534681,-48 l -9.06959,0 c -0.501246,0 -0.906959,0.41772 -0.906959,0.9338 l 0,26.97635 -11.317637,-4.60303 c -0.379109,-0.15439 -0.812031,-0.0286 -1.057515,0.30629 -0.245483,0.33492 -0.244275,0.79809 0.0055,1.13114 L -0.718973,-0.36481 C -0.547255,-0.13509 -0.281818,0 -5.7002158e-5,0 Z',
    strokeColor: 'black',
    strokeOpacity: 1,
    strokeWeight: 1,
    fillColor: '#fefe99',
    fillOpacity: 1,
    rotation: 0,
    scale: 1.0
  };

function init(){
  map = new google.maps.Map(document.getElementById('map_canvas'), {
    center: map_center,
    zoom: 4,
    mapTypeId: google.maps.MapTypeId.HYBRID
  });
  arrow_options = {
    position: map_center,
    icon: arrow_icon,
    clickable: false,
    draggable: true,
    crossOnDrag: true,
    visible: true,
    animation: 0,
    title: 'I am a Draggable-Rotatable Marker!' 
  };
  arrow_marker = new google.maps.Marker(arrow_options);
  arrow_marker.setMap(map);
}
function setRotation(){
  var heading = parseInt(document.getElementById('rotation_value').value);
  if (isNaN(heading)) heading = 0;
  if (heading < 0) heading = 359;
  if (heading > 359) heading = 0;
  arrow_icon.rotation = heading;
  arrow_marker.setOptions({icon:arrow_icon});
  document.getElementById('rotation_value').value = heading;
}
</script>
</head>
<body id="document_body" onload="init();">
  <div id="rotation_control">
    <small>Enter heading to rotate marker&nbsp;&nbsp;&nbsp;&nbsp;</small>
    Heading&deg;<input id="rotation_value" type="number" size="3" value="0" onchange="setRotation();" />
    <small>&nbsp;&nbsp;&nbsp;&nbsp;Drag marker to place marker</small>
    </div>
    <div id="map_canvas"></div>
</body>
</html>

This is exactly what Google does for it's own few symbols available in the SYMBOL class of the Maps API, so if that doesn't convince you... Anyway, I hope this will help you to correctly make and set up a SVG marker for your Google maps endevours.

How to test if string exists in file with Bash?

My version using fgrep

  FOUND=`fgrep -c "FOUND" $VALIDATION_FILE`
  if [ $FOUND -eq 0 ]; then
    echo "Not able to find"
  else
    echo "able to find"     
  fi  

How to install a specific version of a ruby gem?

As others have noted, in general use the -v flag for the gem install command.

If you're developing a gem locally, after cutting a gem from your gemspec:

$ gem install gemname-version.gem

Assuming version 0.8, it would look like this:

$ gem install gemname-0.8.gem

How to check if a double is null?

A double primitive in Java can never be null. It will be initialized to 0.0 if no value has been given for it (except when declaring a local double variable and not assigning a value, but this will produce a compile-time error).

More info on default primitive values here.

Create two blank lines in Markdown

If your Markdown compiler supports HTML, you can add <br/><br/> in the Markdown source.

How do pointer-to-pointer's work in C? (and when might you use them?)

I like this "real world" code example of pointer to pointer usage, in Git 2.0, commit 7b1004b:

Linus once said:

I actually wish more people understood the really core low-level kind of coding. Not big, complex stuff like the lockless name lookup, but simply good use of pointers-to-pointers etc.
For example, I've seen too many people who delete a singly-linked list entry by keeping track of the "prev" entry, and then to delete the entry, doing something like:


   if (prev)
     prev->next = entry->next;
   else
     list_head = entry->next;

and whenever I see code like that, I just go "This person doesn't understand pointers". And it's sadly quite common.

People who understand pointers just use a "pointer to the entry pointer", and initialize that with the address of the list_head. And then as they traverse the list, they can remove the entry without using any conditionals, by just doing a

*pp =  entry->next

pointers

Applying that simplification lets us lose 7 lines from this function even while adding 2 lines of comment.

- struct combine_diff_path *p, *pprev, *ptmp;
+ struct combine_diff_path *p, **tail = &curr;

Chris points out in the comments to the 2016 video "Linus Torvalds's Double Pointer Problem".


kumar points out in the comments the blog post "Linus on Understanding Pointers", where Grisha Trubetskoy explains:

Imagine you have a linked list defined as:

   typedef struct list_entry {
       int val;
       struct list_entry *next;
   } list_entry;

You need to iterate over it from the beginning to end and remove a specific element whose value equals the value of to_remove.
The more obvious way to do this would be:

   list_entry *entry = head; /* assuming head exists and is the first entry of the list */
   list_entry *prev = NULL;
   
   while (entry) { /* line 4 */
       if (entry->val == to_remove)     /* this is the one to remove ; line 5 */
           if (prev)
              prev->next = entry->next; /* remove the entry ; line 7 */
           else
               head = entry->next;      /* special case - first entry ; line 9 */
   
       /* move on to the next entry */
       prev = entry;
       entry = entry->next;
   }

What we are doing above is:

  • iterating over the list until entry is NULL, which means we’ve reached the end of the list (line 4).
  • When we come across an entry we want removed (line 5),
  • we assign the value of current next pointer to the previous one,
  • thus eliminating the current element (line 7).

There is a special case above - at the beginning of the iteration there is no previous entry (prev is NULL), and so to remove the first entry in the list you have to modify head itself (line 9).

What Linus was saying is that the above code could be simplified by making the previous element a pointer to a pointer rather than just a pointer.
The code then looks like this:

   list_entry **pp = &head; /* pointer to a pointer */
   list_entry *entry = head;

   while (entry) {
       if (entry->val == to_remove)
           *pp = entry->next;
       else
            pp = &entry->next;
       entry = entry->next;
   }

The above code is very similar to the previous variant, but notice how we no longer need to watch for the special case of the first element of the list, since pp is not NULL at the beginning. Simple and clever.

Also, someone in that thread commented that the reason this is better is because *pp = entry->next is atomic. It is most certainly NOT atomic.
The above expression contains two dereference operators (* and ->) and one assignment, and neither of those three things is atomic.
This is a common misconception, but alas pretty much nothing in C should ever be assumed to be atomic (including the ++ and -- operators)!

The located assembly's manifest definition does not match the assembly reference

This same error was surfacing for me in my Unit Tests project and resulting in some failing tests. I double-checked which version of the assembly I was using in assembly explorer and checked the contents of the runtime/dependentassembly tags and realized a different version of the assembly I had been using was still being referenced there. Because this was the only directive in my tests project app.config I just tried deleting the entire app.config file, rebuilding the solution, and that did the trick! No more reference errors for me :)

Difference between Static methods and Instance methods

The behavior of an object depends on the variables and the methods of that class. When we create a class we create an object for it. For static methods, we don't require them as static methods means all the objects will have the same copy so there is no need of an object. e.g:

Myclass.get();

In instance method each object will have different behaviour so they have to call the method using the object instance. e.g:

Myclass x = new Myclass();
x.get();

Select all where [first letter starts with B]

SELECT author FROM lyrics WHERE author LIKE 'B%';

Make sure you have an index on author, though!

Combine two OR-queries with AND in Mongoose

It's probably easiest to create your query object directly as:

  Test.find({
      $and: [
          { $or: [{a: 1}, {b: 1}] },
          { $or: [{c: 1}, {d: 1}] }
      ]
  }, function (err, results) {
      ...
  }

But you can also use the Query#and helper that's available in recent 3.x Mongoose releases:

  Test.find()
      .and([
          { $or: [{a: 1}, {b: 1}] },
          { $or: [{c: 1}, {d: 1}] }
      ])
      .exec(function (err, results) {
          ...
      });

What happens to a declared, uninitialized variable in C? Does it have a value?

It depends on the storage duration of the variable. A variable with static storage duration is always implicitly initialized with zero.

As for automatic (local) variables, an uninitialized variable has indeterminate value. Indeterminate value, among other things, mean that whatever "value" you might "see" in that variable is not only unpredictable, it is not even guaranteed to be stable. For example, in practice (i.e. ignoring the UB for a second) this code

int num;
int a = num;
int b = num;

does not guarantee that variables a and b will receive identical values. Interestingly, this is not some pedantic theoretical concept, this readily happens in practice as consequence of optimization.

So in general, the popular answer that "it is initialized with whatever garbage was in memory" is not even remotely correct. Uninitialized variable's behavior is different from that of a variable initialized with garbage.

Delete all data in SQL Server database

It is usually much faster to script out all the objects in the database, and create an empty one, that to delete from or truncate tables.

Image vs Bitmap class

This is a clarification because I have seen things done in code which are honestly confusing - I think the following example might assist others.

As others have said before - Bitmap inherits from the Abstract Image class

Abstract effectively means you cannot create a New() instance of it.

    Image imgBad1 = new Image();        // Bad - won't compile
    Image imgBad2 = new Image(200,200); // Bad - won't compile

But you can do the following:

    Image imgGood;  // Not instantiated object!
    // Now you can do this
    imgGood = new Bitmap(200, 200);

You can now use imgGood as you would the same bitmap object if you had done the following:

    Bitmap bmpGood = new Bitmap(200,200);

The nice thing here is you can draw the imgGood object using a Graphics object

    Graphics gr = default(Graphics);
    gr = Graphics.FromImage(new Bitmap(1000, 1000));
    Rectangle rect = new Rectangle(50, 50, imgGood.Width, imgGood.Height); // where to draw
    gr.DrawImage(imgGood, rect);

Here imgGood can be any Image object - Bitmap, Metafile, or anything else that inherits from Image!

Get source jar files attached to Eclipse for Maven-managed dependencies

in my version of Eclipse helios with m2Eclipse there is no

window --> maven --> Download Artifact Sources (select check)

Under window is only "new window", "new editor" "open perspective" etc.

If you right click on your project, then chose maven--> download sources

Nothing happens. no sources get downloaded, no pom files get updated, no window pops up asking which sources.

Doing mvn xxx outside of eclipse is dangerous - some commands dont work with m2ecilpse - I did that once and lost the entire project, had to reinstall eclipse and start from scratch.

Im still looking for a way to get ecilpse and maven to find and use the source of external jars like servlet-api.

Process all arguments except the first one (in a bash script)

Working in bash 4 or higher version:

#!/bin/bash
echo "$0";         #"bash"
bash --version;    #"GNU bash, version 5.0.3(1)-release (x86_64-pc-linux-gnu)"

In function:

echo $@;              #"p1" "p2" "p3" "p4" "p5"
echo ${@: 0};  #"bash" "p1" "p2" "p3" "p4" "p5"
echo ${@: 1};         #"p1" "p2" "p3" "p4" "p5"
echo ${@: 2};              #"p2" "p3" "p4" "p5"
echo ${@: 2:1};            #"p2"
echo ${@: 2:2};            #"p2" "p3"
echo ${@: -2};                       #"p4" "p5"
echo ${@: -2:1};                     #"p4"

Notice the space between ':' and '-', otherwise it means different:

${var:-word} If var is null or unset,
word is substituted for var. The value of var does not change.

${var:+word} If var is set,
word is substituted for var. The value of var does not change.

Which is described in:Unix / Linux - Shell Substitution

rm: cannot remove: Permission denied

The code says everything:

max@serv$ chmod 777 .

Okay, it doesn't say everything.

In UNIX and Linux, the ability to remove a file is not determined by the access bits of that file. It is determined by the access bits of the directory which contains the file.

Think of it this way -- deleting a file doesn't modify that file. You aren't writing to the file, so why should "w" on the file matter? Deleting a file requires editing the directory that points to the file, so you need "w" on the that directory.

onclick event pass <li> id or value

I prefer to use the HTML5 data API, check this documentation:

A example

_x000D_
_x000D_
$('#some-list li').click(function() {_x000D_
  var textLoaded = 'Loading element with id='_x000D_
         + $(this).data('id');_x000D_
   $('#loading-content').text(textLoaded);_x000D_
});
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>_x000D_
<ul id='some-list'>_x000D_
  <li data-id='1'>One </li>_x000D_
  <li data-id='2'>Two </li>_x000D_
  <!-- ... more li -->_x000D_
  <li data-id='n'>Other</li>_x000D_
</ul>_x000D_
_x000D_
<h1 id='loading-content'></h1>
_x000D_
_x000D_
_x000D_

What's the best way to cancel event propagation between nested ng-click calls?

Sometimes, it may make most sense just to do this:

<widget ng-click="myClickHandler(); $event.stopPropagation()"/>

I chose to do it this way because I didn't want myClickHandler() to stop the event propagation in the many other places it was used.

Sure, I could've added a boolean parameter to the handler function, but stopPropagation() is much more meaningful than just true.

Rails find_or_create_by more than one attribute?

For anyone else who stumbles across this thread but needs to find or create an object with attributes that might change depending on the circumstances, add the following method to your model:

# Return the first object which matches the attributes hash
# - or -
# Create new object with the given attributes
#
def self.find_or_create(attributes)
  Model.where(attributes).first || Model.create(attributes)
end

Optimization tip: regardless of which solution you choose, consider adding indexes for the attributes you are querying most frequently.

How can I enable auto complete support in Notepad++?

Don't forget to add your libraries & check your versions. Good information is in Using Notepad Plus Plus as a script editor.

How can I implement the Iterable interface?

Iterable is a generic interface. A problem you might be having (you haven't actually said what problem you're having, if any) is that if you use a generic interface/class without specifying the type argument(s) you can erase the types of unrelated generic types within the class. An example of this is in Non-generic reference to generic class results in non-generic return types.

So I would at least change it to:

public class ProfileCollection implements Iterable<Profile> { 
    private ArrayList<Profile> m_Profiles;

    public Iterator<Profile> iterator() {        
        Iterator<Profile> iprof = m_Profiles.iterator();
        return iprof; 
    }

    ...

    public Profile GetActiveProfile() {
        return (Profile)m_Profiles.get(m_ActiveProfile);
    }
}

and this should work:

for (Profile profile : m_PC) {
    // do stuff
}

Without the type argument on Iterable, the iterator may be reduced to being type Object so only this will work:

for (Object profile : m_PC) {
    // do stuff
}

This is a pretty obscure corner case of Java generics.

If not, please provide some more info about what's going on.

Import Excel to Datagridview

I used the following code, it's working!

using System.Data.OleDb;
using System.IO;
using System.Text.RegularExpressions;

private void btopen_Click(object sender, EventArgs e)
{
   try
   {
     OpenFileDialog openFileDialog1 = new OpenFileDialog();  //create openfileDialog Object
     openFileDialog1.Filter = "XML Files (*.xml; *.xls; *.xlsx; *.xlsm; *.xlsb) |*.xml; *.xls; *.xlsx; *.xlsm; *.xlsb";//open file format define Excel Files(.xls)|*.xls| Excel Files(.xlsx)|*.xlsx| 
     openFileDialog1.FilterIndex = 3;

     openFileDialog1.Multiselect = false;        //not allow multiline selection at the file selection level
     openFileDialog1.Title = "Open Text File-R13";   //define the name of openfileDialog
     openFileDialog1.InitialDirectory = @"Desktop"; //define the initial directory

     if (openFileDialog1.ShowDialog() == DialogResult.OK)        //executing when file open
     {
       string pathName = openFileDialog1.FileName;
       fileName = System.IO.Path.GetFileNameWithoutExtension(openFileDialog1.FileName);
       DataTable tbContainer = new DataTable();
       string strConn = string.Empty;
       string sheetName = fileName;

       FileInfo file = new FileInfo(pathName);
       if (!file.Exists) { throw new Exception("Error, file doesn't exists!"); }
       string extension = file.Extension;
       switch (extension)
       {
          case ".xls":
                   strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + pathName + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'";
                   break;
          case ".xlsx":
                   strConn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + pathName + ";Extended Properties='Excel 12.0;HDR=Yes;IMEX=1;'";
                   break;
          default:
                   strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + pathName + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'";
                   break;
         }
         OleDbConnection cnnxls = new OleDbConnection(strConn);
         OleDbDataAdapter oda = new OleDbDataAdapter(string.Format("select * from [{0}$]", sheetName), cnnxls);
         oda.Fill(tbContainer);

         dtGrid.DataSource = tbContainer;
       }

     }
     catch (Exception)
     {
        MessageBox.Show("Error!");
     }
  }

target="_blank" vs. target="_new"

target="_blank" opens a new tab in most browsers.

UIView Hide/Show with animation

swift 4.2

with extension :

extension UIView {
func hideWithAnimation(hidden: Bool) {
        UIView.transition(with: self, duration: 0.5, options: .transitionCrossDissolve, animations: {
            self.isHidden = hidden
        })
    }
}

simple method:

func setView(view: UIView, hidden: Bool) {
    UIView.transition(with: view, duration: 0.5, options: .transitionCrossDissolve, animations: {
        view.isHidden = hidden
    })
}

Shift elements in a numpy array

Benchmarks & introducing Numba

1. Summary

  • The accepted answer (scipy.ndimage.interpolation.shift) is the slowest solution listed in this page.
  • Numba (@numba.njit) gives some performance boost when array size smaller than ~25.000
  • "Any method" equally good when array size large (>250.000).
  • The fastest option really depends on
        (1)  Length of your arrays
        (2)  Amount of shift you need to do.
  • Below is the picture of the timings of all different methods listed on this page (2020-07-11), using constant shift = 10. As one can see, with small array sizes some methods are use more than +2000% time than the best method.

Relative timings, constant shift (10), all methods

2. Detailed benchmarks with the best options

  • Choose shift4_numba (defined below) if you want good all-arounder

Relative timings, best methods (Benchmarks)

3. Code

3.1 shift4_numba

  • Good all-arounder; max 20% wrt. to the best method with any array size
  • Best method with medium array sizes: ~ 500 < N < 20.000.
  • Caveat: Numba jit (just in time compiler) will give performance boost only if you are calling the decorated function more than once. The first call takes usually 3-4 times longer than the subsequent calls.
import numba

@numba.njit
def shift4_numba(arr, num, fill_value=np.nan):
    if num >= 0:
        return np.concatenate((np.full(num, fill_value), arr[:-num]))
    else:
        return np.concatenate((arr[-num:], np.full(-num, fill_value)))

3.2. shift5_numba

  • Best option with small (N <= 300.. 1500) array sizes. Treshold depends on needed amount of shift.
  • Good performance on any array size; max + 50% compared to the fastest solution.
  • Caveat: Numba jit (just in time compiler) will give performance boost only if you are calling the decorated function more than once. The first call takes usually 3-4 times longer than the subsequent calls.
import numba

@numba.njit
def shift5_numba(arr, num, fill_value=np.nan):
    result = np.empty_like(arr)
    if num > 0:
        result[:num] = fill_value
        result[num:] = arr[:-num]
    elif num < 0:
        result[num:] = fill_value
        result[:num] = arr[-num:]
    else:
        result[:] = arr
    return result

3.3. shift5

  • Best method with array sizes ~ 20.000 < N < 250.000
  • Same as shift5_numba, just remove the @numba.njit decorator.

4 Appendix

4.1 Details about used methods

  • shift_scipy: scipy.ndimage.interpolation.shift (scipy 1.4.1) - The option from accepted answer, which is clearly the slowest alternative.
  • shift1: np.roll and out[:num] xnp.nan by IronManMark20 & gzc
  • shift2: np.roll and np.put by IronManMark20
  • shift3: np.pad and slice by gzc
  • shift4: np.concatenate and np.full by chrisaycock
  • shift5: using two times result[slice] = x by chrisaycock
  • shift#_numba: @numba.njit decorated versions of the previous.

The shift2 and shift3 contained functions that were not supported by the current numba (0.50.1).

4.2 Other test results

4.2.1 Relative timings, all methods

4.2.2 Raw timings, all methods

4.2.3 Raw timings, few best methods

Establish a VPN connection in cmd

Is Powershell an option?

Start Powershell:

powershell

Create the VPN Connection: Add-VpnConnection

Add-VpnConnection [-Name] <string> [-ServerAddress] <string> [-TunnelType <string> {Pptp | L2tp | Sstp | Ikev2 | Automatic}] [-EncryptionLevel <string> {NoEncryption | Optional | Required | Maximum}] [-AuthenticationMethod <string[]> {Pap | Chap | MSChapv2 | Eap}] [-SplitTunneling] [-AllUserConnection] [-L2tpPsk <string>] [-RememberCredential] [-UseWinlogonCredential] [-EapConfigXmlStream <xml>] [-Force] [-PassThru] [-WhatIf] [-Confirm] 

Edit VPN connections: Set-VpnConnection

Set-VpnConnection [-Name] <string> [[-ServerAddress] <string>] [-TunnelType <string> {Pptp | L2tp | Sstp | Ikev2 | Automatic}] [-EncryptionLevel <string> {NoEncryption | Optional | Required | Maximum}] [-AuthenticationMethod <string[]> {Pap | Chap | MSChapv2 | Eap}] [-SplitTunneling <bool>] [-AllUserConnection] [-L2tpPsk <string>] [-RememberCredential <bool>] [-UseWinlogonCredential <bool>] [-EapConfigXmlStream <xml>] [-PassThru] [-Force] [-WhatIf] [-Confirm]

Lookup VPN Connections: Get-VpnConnection

Get-VpnConnection [[-Name] <string[]>] [-AllUserConnection]

Connect: rasdial [connectionName]

rasdial connectionname [username [password | \]] [/domain:domain*] [/phone:phonenumber] [/callback:callbacknumber] [/phonebook:phonebookpath] [/prefixsuffix**]

You can manage your VPN connections with the powershell commands above, and simply use the connection name to connect via rasdial.

The results of Get-VpnConnection can be a little verbose. This can be simplified with a simple Select-Object filter:

Get-VpnConnection | Select-Object -Property Name

More information can be found here:

FFMPEG mp4 from http live streaming m3u8 file?

Your command is completely incorrect. The output format is not rawvideo and you don't need the bitstream filter h264_mp4toannexb which is used when you want to convert the h264 contained in an mp4 to the Annex B format used by MPEG-TS for example. What you want to use instead is the aac_adtstoasc for the AAC streams.

ffmpeg -i http://.../playlist.m3u8 -c copy -bsf:a aac_adtstoasc output.mp4

How to initialize a nested struct?

package main

type    Proxy struct {
        Address string
        Port    string
    }

type Configuration struct {
    Proxy
    Val   string

}

func main() {

    c := &Configuration{
        Val: "test",
        Proxy: Proxy {
            Address: "addr",
            Port:    "80",
        },
    }

}

How to open a workbook specifying its path

Workbooks.open("E:\sarath\PTMetrics\20131004\D8 L538-L550 16MY\D8 L538-L550_16MY_Powertrain Metrics_20131002.xlsm")

Or, in a more structured way...

Sub openwb()
    Dim sPath As String, sFile As String
    Dim wb As Workbook

    sPath = "E:\sarath\PTMetrics\20131004\D8 L538-L550 16MY\"
    sFile = sPath & "D8 L538-L550_16MY_Powertrain Metrics_20131002.xlsm"

    Set wb = Workbooks.Open(sFile)
End Sub

How do you run a SQL Server query from PowerShell?

Invoke-Sqlcmd -Query "sp_who" -ServerInstance . -QueryTimeout 3

Declaring & Setting Variables in a Select Statement

The SET command is TSQL specific - here's the PLSQL equivalent to what you posted:

v_date1 DATE := TO_DATE('03-AUG-2010', 'DD-MON-YYYY');

SELECT u.visualid
  FROM USAGE u 
 WHERE u.usetime > v_date1;

There's also no need for prefixing variables with "@"; I tend to prefix variables with "v_" to distinguish between variables & columns/etc.

See this thread about the Oracle equivalent of NOLOCK...

What's the environment variable for the path to the desktop?

If you wish to use the

[Environment]::GetFolderPath("Desktop")

from within a cmd.exe, you may do so (thanks to MS User Marian Pascalau on this thread)

set dkey=Desktop
set dump=powershell.exe -NoLogo -NonInteractive "Write-Host $([System.Environment]::GetFolderPath([System.Environment+SpecialFolder]::%dkey%))"
for /F %%i in ('%dump%') do set dir=%%i

echo Desktop directory is %dir%

How to cache data in a MVC application

I will say implementing Singleton on this persisting data issue can be a solution for this matter in case you find previous solutions much complicated

 public class GPDataDictionary
{
    private Dictionary<string, object> configDictionary = new Dictionary<string, object>();

    /// <summary>
    /// Configuration values dictionary
    /// </summary>
    public Dictionary<string, object> ConfigDictionary
    {
        get { return configDictionary; }
    }

    private static GPDataDictionary instance;
    public static GPDataDictionary Instance
    {
        get
        {
            if (instance == null)
            {
                instance = new GPDataDictionary();
            }
            return instance;
        }
    }

    // private constructor
    private GPDataDictionary() { }

}  // singleton

How to test for $null array in PowerShell

The other answers address the main thrust of the question, but just to comment on this part...

PS C:\> [array]$foo = @("bar")
PS C:\> $foo -eq $null
PS C:\>

How can "-eq $null" give no results? It's either $null or it's not.

It's confusing at first, but that is giving you the result of $foo -eq $null, it's just that the result has no displayable representation.

Since $foo holds an array, $foo -eq $null means "return an array containing the elements of $foo that are equal to $null". Are there any elements of $foo that are equal to $null? No, so $foo -eq $null should return an empty array. That's exactly what it does, the problem is that when an empty array is displayed at the console you see...nothing...

PS> @()
PS> 

The array is still there, even if you can't see its elements...

PS> @().GetType()

IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
True     True     Object[]                                 System.Array


PS> @().Length
0

We can use similar commands to confirm that $foo -eq $null is returning an array that we're not able to "see"...

PS> $foo -eq $null
PS> ($foo -eq $null).GetType()

IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
True     True     Object[]                                 System.Array


PS> ($foo -eq $null).Length
0
PS> ($foo -eq $null).GetValue(0)
Exception calling "GetValue" with "1" argument(s): "Index was outside the bounds of the array."
At line:1 char:1
+ ($foo -eq $null).GetValue(0)
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : IndexOutOfRangeException

Note that I am calling the Array.GetValue method instead of using the indexer (i.e. ($foo -eq $null)[0]) because the latter returns $null for invalid indices and there's no way to distinguish them from a valid index that happens to contain $null.

We see similar behavior if we test for $null in/against an array that contains $null elements...

PS> $bar = @($null)
PS> $bar -eq $null
PS> ($bar -eq $null).GetType()

IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
True     True     Object[]                                 System.Array


PS> ($bar -eq $null).Length
1
PS> ($bar -eq $null).GetValue(0)
PS> $null -eq ($bar -eq $null).GetValue(0)
True
PS> ($bar -eq $null).GetValue(0) -eq $null
True
PS> ($bar -eq $null).GetValue(1)
Exception calling "GetValue" with "1" argument(s): "Index was outside the bounds of the array."
At line:1 char:1
+ ($bar -eq $null).GetValue(1)
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : IndexOutOfRangeException

In this case, $bar -eq $null returns an array containing one element, $null, which has no visual representation at the console...

PS> @($null)
PS> @($null).GetType()

IsPublic IsSerial Name                                     BaseType
-------- -------- ----                                     --------
True     True     Object[]                                 System.Array


PS> @($null).Length
1

Why Does OAuth v2 Have Both Access and Refresh Tokens?

Why not just make the access_token last as long as the refresh_token and not have a refresh_token?

In addition to great answers other people have provided, there is another reason why we would use refresh tokens and it's to do with claims.

Each token contains claims which can include anything from the user's name, their roles, or the provider which created the claim. As a token is refreshed, these claims are updated.

If we refresh the tokens more often, we are obviously putting more strain on our identity services; however, we are getting more accurate and up-to-date claims.

Confirm password validation in Angular 6

It's not necessary to use nested form groups and a custom ErrorStateMatcher for confirm password validation. These steps were added to facilitate coordination between the password fields, but you can do that without all the overhead.

Here is an example:

this.registrationForm = this.fb.group({
  username: ['', Validators.required],
  email: ['', [Validators.required, Validators.email]],
  password1: ['', [Validators.required, (control) => this.validatePasswords(control, 'password1') ] ],
  password2: ['', [Validators.required, (control) => this.validatePasswords(control, 'password2') ] ]
});

Note that we are passing additional context to the validatePasswords method (whether the source is password1 or password2).

  validatePasswords(control: AbstractControl, name: string) {
    if (this.registrationForm === undefined || this.password1.value === '' || this.password2.value === '') {
      return null;
    } else if (this.password1.value === this.password2.value) {
      if (name === 'password1' && this.password2.hasError('passwordMismatch')) {
        this.password1.setErrors(null);
        this.password2.updateValueAndValidity();
      } else if (name === 'password2' && this.password1.hasError('passwordMismatch')) {
        this.password2.setErrors(null);
        this.password1.updateValueAndValidity();
      }
      return null;
    } else {
      return {'passwordMismatch': { value: 'The provided passwords do not match'}};
    }  

Note here that when the passwords match, we coordinate with the other password field to have its validation updated. This will clear any stale password mismatch errors.

And for completeness sake, here are the getters that define this.password1 and this.password2.

  get password1(): AbstractControl {
    return this.registrationForm.get('password1');
  }

  get password2(): AbstractControl {
    return this.registrationForm.get('password2');
  }

How to convert ISO8859-15 to UTF8?

I found this to work for me:

iconv -f ISO-8859-14 Agreement.txt -t UTF-8 -o agreement.txt

Set background image according to screen resolution

Delete your "body background image code" then paste this code:

html { 
    background: url(../img/background.jpg) no-repeat center center fixed #000; 
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
}

How can I store HashMap<String, ArrayList<String>> inside a list?

First, let me fix a little bit your declaration:

List<Map<String, List<String>>> listOfMapOfList = 
    new HashList<Map<String, List<String>>>();

Please pay attention that I used concrete class (HashMap) only once. It is important to use interface where you can to be able to change the implementation later.

Now you want to add element to the list, don't you? But the element is a map, so you have to create it:

Map<String, List<String>> mapOfList = new HashMap<String, List<String>>();

Now you want to populate the map. Fortunately you can use utility that creates lists for you, otherwise you have to create list separately:

mapOfList.put("mykey", Arrays.asList("one", "two", "three"));

OK, now we are ready to add the map into the list:

listOfMapOfList.add(mapOfList);

BUT:

Stop creating complicated collections right now! Think about the future: you will probably have to change the internal map to something else or list to set etc. This will probably cause you to re-write significant parts of your code. Instead define class that contains you data and then add it to one-dimentional collection:

Let's call your class Student (just as example):

public Student {
    private String firstName;
    private String lastName;
    private int studentId;

    private Colectiuon<String> courseworks = Collections.emtpyList();

    //constructors, getters, setters etc
}

Now you can define simple collection:

Collection<Student> students = new ArrayList<Student>();

If in future you want to put your students into map where key is the studentId, do it:

Map<Integer, Student> students = new HashMap<Integer, Student>();

Java Hashmap: How to get key from value?

My 2 cents. You can get the keys in an array and then loop through the array. This will affect performance of this code block if the map is pretty big , where in you are getting the keys in an array first which might consume some time and then you are looping. Otherwise for smaller maps it should be ok.

String[] keys =  yourMap.keySet().toArray(new String[0]);

for(int i = 0 ; i < keys.length ; i++){
    //This is your key    
    String key = keys[i];

    //This is your value
    yourMap.get(key)            
}

How to get to Model or Viewbag Variables in a Script Tag

try this method

<script type="text/javascript">

    function set(value) {
        return value;
    }

    alert(set(@Html.Raw(Json.Encode(Model.Message)))); // Message set from controller
    alert(set(@Html.Raw(Json.Encode(ViewBag.UrMessage))));

</script>

Thanks

C# Linq Where Date Between 2 Dates

_x000D_
_x000D_
 public List<tbltask> gettaskssdata(int? c, int? userid, string a, string StartDate, string EndDate, int? ProjectID, int? statusid)_x000D_
        {_x000D_
            List<tbltask> tbtask = new List<tbltask>();_x000D_
            DateTime sdate = (StartDate != "") ? Convert.ToDateTime(StartDate).Date : new DateTime();_x000D_
            DateTime edate = (EndDate != "") ? Convert.ToDateTime(EndDate).Date : new DateTime();_x000D_
            tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser)._x000D_
                Where(x => x.tblproject.company_id == c_x000D_
                    && (ProjectID == 0 || ProjectID == x.tblproject.ProjectId)_x000D_
                    && (statusid == 0 || statusid == x.tblstatu.StatusId)_x000D_
                    && (a == "" || (x.TaskName.Contains(a) || x.tbUser.User_name.Contains(a)))_x000D_
                    && ((StartDate == "" && EndDate == "") || ((x.StartDate >= sdate && x.EndDate <= edate)))).ToList();_x000D_
_x000D_
_x000D_
_x000D_
            return tbtask;_x000D_
_x000D_
_x000D_
        }
_x000D_
_x000D_
_x000D_

this my query for search records based on searchdata and between start to end date

Parse usable Street Address, City, State, Zip from a string

This type of problem is hard to solve because of underlying ambiguities in the data.

Here is a Perl based solution that defines a recursive descent grammar tree based on regular expressions to parse many valid combination of street addresses: http://search.cpan.org/~kimryan/Lingua-EN-AddressParse-1.20/lib/Lingua/EN/AddressParse.pm . This includes sub properties within an address such as: 12 1st Avenue N Suite # 2 Somewhere CA 12345 USA

It is similar to http://search.cpan.org/~timb/Geo-StreetAddress-US-1.03/US.pm mentioned above, but also works for addresses that are not from the USA, such as the UK, Australia and Canada.

Here is the output for one of your sample addresses. Note that the name section would need to be removed first from "A. P. Croll & Son 2299 Lewes-Georgetown Hwy, Georgetown, DE 19947" to reduce it to "2299 Lewes-Georgetown Hwy, Georgetown, DE 19947". This is easily achieved by removing all data up to the first number found in the string.

Non matching part       ''
Error                   '0'
Error descriptions      ''
Case all                '2299 Lewes-Georgetown Hwy Georgetown DE 19947'
COMPONENTS              ''
country                 ''
po_box_type             ''
post_box                ''
post_code               '19947'
pre_cursor              ''
property_identifier     '2299'
property_name           ''
road_box                ''
street                  'Lewes-Georgetown'
street_direction        ''
street_type             'Hwy'
sub_property_identifier ''
subcountry              'DE'
suburb                  'Georgetown'

Where Sticky Notes are saved in Windows 10 1607

If at all you can't find .snt folder and above mentioned answers don't work for you. you can simply take plum.sqlite file and read it online or sqlite editor.

for online you can refer to http://inloop.github.io/sqlite-viewer/ link and browse the url as C:\Users\YOURUSERNAME\AppData\Local\Packages\Microsoft.MicrosoftStickyNotes_8wekyb3d8bbwe\LocalState

and pick sql lite file and execute it. Post executing select Note and you will find all rows corresponding to each sticky notes you have lost. Select the Text column and copy content, you will find all your data there.

ENJOY !!!! enter image description here

Return HTTP status code 201 in flask

You can do

result = {'a': 'b'}
return jsonify(result), 201

if you want to return a JSON data in the response along with the error code You can read about responses here and here for make_response API details

How to use timeit module

# ????????? ????? ?????

def gen_prime(x):
    multiples = []
    results = []
    for i in range(2, x+1):
        if i not in multiples:
            results.append(i)
            for j in range(i*i, x+1, i):
                multiples.append(j)

    return results


import timeit

# ???????? ?????

start_time = timeit.default_timer()
gen_prime(3000)
print(timeit.default_timer() - start_time)

# start_time = timeit.default_timer()
# gen_prime(1001)
# print(timeit.default_timer() - start_time)

Combine multiple Collections into a single logical Collection?

You could create a new List and addAll() of your other Lists to it. Then return an unmodifiable list with Collections.unmodifiableList().

Calculating Page Table Size

Since we have a virtual address space of 2^32 and each page size is 2^12, we can store (2^32/2^12) = 2^20 pages. Since each entry into this page table has an address of size 4 bytes, then we have 2^20*4 = 4MB. So the page table takes up 4MB in memory.

Remove #N/A in vlookup result

To avoid errors in any excel function, use the Error Handling functions that start with IS* in Excel. Embed your function with these error handing functions and avoid the undesirable text in your results. More info in OfficeTricks Page

Powershell Get-ChildItem most recent file in directory

You could try to sort descending "sort LastWriteTime -Descending" and then "select -first 1." Not sure which one is faster

Linq to Entities join vs groupjoin

According to eduLINQ:

The best way to get to grips with what GroupJoin does is to think of Join. There, the overall idea was that we looked through the "outer" input sequence, found all the matching items from the "inner" sequence (based on a key projection on each sequence) and then yielded pairs of matching elements. GroupJoin is similar, except that instead of yielding pairs of elements, it yields a single result for each "outer" item based on that item and the sequence of matching "inner" items.

The only difference is in return statement:

Join:

var lookup = inner.ToLookup(innerKeySelector, comparer); 
foreach (var outerElement in outer) 
{ 
    var key = outerKeySelector(outerElement); 
    foreach (var innerElement in lookup[key]) 
    { 
        yield return resultSelector(outerElement, innerElement); 
    } 
} 

GroupJoin:

var lookup = inner.ToLookup(innerKeySelector, comparer); 
foreach (var outerElement in outer) 
{ 
    var key = outerKeySelector(outerElement); 
    yield return resultSelector(outerElement, lookup[key]); 
} 

Read more here:

How to use ? : if statements with Razor and inline code blocks

The key is to encapsulate the expression in parentheses after the @ delimiter. You can make any compound expression work this way.

docker-compose up for only certain containers

You can start containers by using:

$ docker-compose up -d client

This will run containers in the background and output will be avaiable from

$ docker-compose logs

and it will consist of all your started containers

Can Selenium interact with an existing browser session?

Javascript solution:

I have successfully attached to existing browser session using this function

webdriver.WebDriver.attachToSession(executor, session_id);

Documentation can be found here.

Powershell Invoke-WebRequest Fails with SSL/TLS Secure Channel

I haven't figure out the reason but reinstalling the .pfx certificate(both in current user and local machine) works for me.

Colouring plot by factor in R

data<-iris
plot(data$Sepal.Length, data$Sepal.Width, col=data$Species)
legend(7,4.3,unique(data$Species),col=1:length(data$Species),pch=1)

should do it for you. But I prefer ggplot2 and would suggest that for better graphics in R.

Ansible Ignore errors in tasks and fail at end of the playbook if any tasks had errors

Use Fail module.

  1. Use ignore_errors with every task that you need to ignore in case of errors.
  2. Set a flag (say, result = false) whenever there is a failure in any task execution
  3. At the end of the playbook, check if flag is set, and depending on that, fail the execution
- fail: msg="The execution has failed because of errors."
  when: flag == "failed"

Update:

Use register to store the result of a task like you have shown in your example. Then, use a task like this:

- name: Set flag
  set_fact: flag = failed
  when: "'FAILED' in command_result.stderr"

super() in Java

I would like to share with codes whatever I understood.

The super keyword in java is a reference variable that is used to refer parent class objects. It is majorly used in the following contexts:-

1. Use of super with variables:

class Vehicle 
{ 
    int maxSpeed = 120; 
} 

/* sub class Car extending vehicle */
class Car extends Vehicle 
{ 
    int maxSpeed = 180; 

    void display() 
    { 
        /* print maxSpeed of base class (vehicle) */
        System.out.println("Maximum Speed: " + super.maxSpeed); 
    } 
} 

/* Driver program to test */
class Test 
{ 
    public static void main(String[] args) 
    { 
        Car small = new Car(); 
        small.display(); 
    } 
} 

Output:-

Maximum Speed: 120
  1. Use of super with methods:
/* Base class Person */
class Person 
{ 
    void message() 
    { 
        System.out.println("This is person class"); 
    } 
} 

/* Subclass Student */
class Student extends Person 
{ 
    void message() 
    { 
        System.out.println("This is student class"); 
    } 

    // Note that display() is only in Student class 
    void display() 
    { 
        // will invoke or call current class message() method 
        message(); 

        // will invoke or call parent class message() method 
        super.message(); 
    } 
} 

/* Driver program to test */
class Test 
{ 
    public static void main(String args[]) 
    { 
        Student s = new Student(); 

        // calling display() of Student 
        s.display(); 
    } 
}

Output:-

This is student class
This is person class

3. Use of super with constructors:

class Person 
{ 
    Person() 
    { 
        System.out.println("Person class Constructor"); 
    } 
} 

/* subclass Student extending the Person class */
class Student extends Person 
{ 
    Student() 
    { 
        // invoke or call parent class constructor 
        super(); 

        System.out.println("Student class Constructor"); 
    } 
} 

/* Driver program to test*/
class Test 
{ 
    public static void main(String[] args) 
    { 
        Student s = new Student(); 
    } 
} 

Output:-

Person class Constructor
Student class Constructor

Choosing a file in Python with simple Dialog

I obtained much better results with wxPython than tkinter, as suggested in this answer to a later duplicate question:

https://stackoverflow.com/a/9319832

The wxPython version produced the file dialog that looked the same as the open file dialog from just about any other application on my OpenSUSE Tumbleweed installation with the xfce desktop, whereas tkinter produced something cramped and hard to read with an unfamiliar side-scrolling interface.

How to uninstall Apache with command line

If Apache was installed using NSIS installer it should have left an uninstaller. You should search inside Apache installation directory for executable named unistaller.exe or something like that. NSIS uninstallers support /S flag by default for silent uninstall. So you can run something like "C:\Program Files\<Apache installation dir here>\uninstaller.exe" /S

From NSIS documentation:

3.2.1 Common Options

/NCRC disables the CRC check, unless CRCCheck force was used in the script. /S runs the installer or uninstaller silently. See section 4.12 for more information. /D sets the default installation directory ($INSTDIR), overriding InstallDir and InstallDirRegKey. It must be the last parameter used in the command line and must not contain any quotes, even if the path contains spaces. Only absolute paths are supported.

Difference between HashMap and Map in Java..?

Map is an interface in Java. And HashMap is an implementation of that interface (i.e. provides all of the methods specified in the interface).

jQuery click events not working in iOS

You should bind the tap event, the click does not exist on mobile safari or in the UIWbview. You can also use this polyfill ,to avoid the 300ms delay when a link is touched.

Failed to load ApplicationContext (with annotation)

In my case, I had to do the following while running with Junit5

@SpringBootTest(classes = {abc.class}) @ExtendWith(SpringExtension.class

Here abc.class was the class that was being tested

How to fix "Headers already sent" error in PHP

I got this error many times before, and I am certain all PHP programmer got this error at least once before.

Possible Solution 1

This error may have been caused by the blank spaces before the start of the file or after the end of the file.These blank spaces should not be here.

ex) THERE SHOULD BE NO BLANK SPACES HERE

   echo "your code here";

?>
THERE SHOULD BE NO BLANK SPACES HERE

Check all files associated with file that causes this error.

Note: Sometimes EDITOR(IDE) like gedit (a default linux editor) add one blank line on save file. This should not happen. If you are using Linux. you can use VI editor to remove space/lines after ?> at the end of the page.

Possible Solution 2: If this is not your case, then use ob_start to output buffering:

<?php
  ob_start();

  // code 

 ob_end_flush();
?> 

This will turn output buffering on and your headers will be created after the page is buffered.

printing a two dimensional array in python

A combination of list comprehensions and str joins can do the job:

inf = float('inf')
A = [[0,1,4,inf,3],
     [1,0,2,inf,4],
     [4,2,0,1,5],
     [inf,inf,1,0,3],
     [3,4,5,3,0]]

print('\n'.join([''.join(['{:4}'.format(item) for item in row]) 
      for row in A]))

yields

   0   1   4 inf   3
   1   0   2 inf   4
   4   2   0   1   5
 inf inf   1   0   3
   3   4   5   3   0

Using for-loops with indices is usually avoidable in Python, and is not considered "Pythonic" because it is less readable than its Pythonic cousin (see below). However, you could do this:

for i in range(n):
    for j in range(n):
        print '{:4}'.format(A[i][j]),
    print

The more Pythonic cousin would be:

for row in A:
    for val in row:
        print '{:4}'.format(val),
    print

However, this uses 30 print statements, whereas my original answer uses just one.

docker unauthorized: authentication required - upon push with successful login

I was running into a similar issue with a similarly unhelpful error message, but it turned out to be because I was trying to push an image that I had built against a docker-machine managed instance.

When I logged into the instance itself, did docker login and docker push everything worked fine.

How can I convince IE to simply display application/json rather than offer to download it?

I had a similar problem. I was using the "$. GetJSON" jQuery and everything worked perfectly in Firefox and Chrome.

But it did not work in IE. So I tried to directly access the URL of json, but in IE it asked if I wanted to download the file.

After much searching I saw that there must be a header in the result with a content-type, in my case, the content-type was:

header("Content-type: text/html; charset=iso-8859-1");

But when the page that made the request receives this json, in IE, you have to be specified SAME CONTENT-TYPE, in my case was:

$.getJSON (
"<? site_url php echo (" ajax / tipoMenu ")?>"
{contentType: 'text / html; charset = utf-8'},
function (result) {

hugs

How do you convert Html to plain text?

HTTPUtility.HTMLEncode() is meant to handle encoding HTML tags as strings. It takes care of all the heavy lifting for you. From the MSDN Documentation:

If characters such as blanks and punctuation are passed in an HTTP stream, they might be misinterpreted at the receiving end. HTML encoding converts characters that are not allowed in HTML into character-entity equivalents; HTML decoding reverses the encoding. For example, when embedded in a block of text, the characters < and >, are encoded as &lt; and &gt; for HTTP transmission.

HTTPUtility.HTMLEncode() method, detailed here:

public static void HtmlEncode(
  string s,
  TextWriter output
)

Usage:

String TestString = "This is a <Test String>.";
StringWriter writer = new StringWriter();
Server.HtmlEncode(TestString, writer);
String EncodedString = writer.ToString();

Laravel: Using try...catch with DB::transaction()

I've decided to give an answer to this question because I think it can be solved using a simpler syntax than the convoluted try-catch block. The Laravel documentation is pretty brief on this subject.

Instead of using try-catch, you can just use the DB::transaction(){...} wrapper like this:

// MyController.php
public function store(Request $request) {
    return DB::transaction(function() use ($request) {
        $user = User::create([
            'username' => $request->post('username')
        ]);

        // Add some sort of "log" record for the sake of transaction:
        $log = Log::create([
            'message' => 'User Foobar created'
        ]);

        // Lets add some custom validation that will prohibit the transaction:
        if($user->id > 1) {
            throw AnyException('Please rollback this transaction');
        }

        return response()->json(['message' => 'User saved!']);
    });
};

You should then see that the User and the Log record cannot exist without eachother.

Some notes on the implementation above:

  • Make sure to return the transaction, so that you can use the response() you return within its callback.
  • Make sure to throw an exception if you want the transaction to be rollbacked (or have a nested function that throws the exception for you automatically, like an SQL exception from within Eloquent).
  • The id, updated_at, created_at and any other fields are AVAILABLE AFTER CREATION for the $user object (for the duration of this transaction). The transaction will run through any of the creation logic you have. HOWEVER, the whole record is discarded when the AnyException is thrown. This means that for instance an auto-increment column for id does get incremented on failed transactions.

Tested on Laravel 5.8

Importing a Maven project into Eclipse from Git

I would prefer to import projects into Eclipse as maven projects rather than git project. Doing this will still allow the project contents to be recognized as git contents. You can continue to perform git operations from Eclipse. As you have mentioned the reverse is not true.

The nature of a project in Eclipse is not based on the SCM which holds the project, but on the type of project - whether war or jar, etc. - which is automagically determined when the project is imported as maven project.

I would be hesitant to check-in to SCM IDE-specific metadata. Doing so assumes a lot of things - all developers are using the same IDE or version of the IDE, perhaps same version of JDK/JRE, that they continue to use the same version throughout the project lifecycle and so on.

What is the "hasClass" function with plain JavaScript?

I use a simple/minimal solution, one line, cross browser, and works with legacy browsers as well:

/\bmyClass/.test(document.body.className) // notice the \b command for whole word 'myClass'

This method is great because does not require polyfills and if you use them for classList it's much better in terms of performance. At least for me.

Update: I made a tiny polyfill that's an all round solution I use now:

function hasClass(element,testClass){
  if ('classList' in element) { return element.classList.contains(testClass);
} else { return new Regexp(testClass).exec(element.className); } // this is better

//} else { return el.className.indexOf(testClass) != -1; } // this is faster but requires indexOf() polyfill
  return false;
}

For the other class manipulation, see the complete file here.

How to JSON decode array elements in JavaScript?

var obj = jQuery.parseJSON('{"name":"John"}');
alert( obj.name === "John" );

See the jQuery API.

Ruby on Rails generates model field:type - what are the options for field:type?

$ rails g model Item name:string description:text product:references

I too found the guides difficult to use. Easy to understand, but hard to find what I am looking for.

Also, I have temp projects that I run the rails generate commands on. Then once I get them working I run it on my real project.

Reference for the above code: http://guides.rubyonrails.org/getting_started.html#associating-models

A child container failed during start java.util.concurrent.ExecutionException

Added AWS dependency and had this error. When I remove it from pom the error is gone. Probably you might have the same situation.

Make code in LaTeX look *nice*

The listings package is quite nice and very flexible (e.g. different sizes for comments and code).

_DEBUG vs NDEBUG

I rely on NDEBUG, because it's the only one whose behavior is standardized across compilers and implementations (see documentation for the standard assert macro). The negative logic is a small readability speedbump, but it's a common idiom you can quickly adapt to.

To rely on something like _DEBUG would be to rely on an implementation detail of a particular compiler and library implementation. Other compilers may or may not choose the same convention.

The third option is to define your own macro for your project, which is quite reasonable. Having your own macro gives you portability across implementations and it allows you to enable or disable your debugging code independently of the assertions. Though, in general, I advise against having different classes of debugging information that are enabled at compile time, as it causes an increase in the number of configurations you have to build (and test) for arguably small benefit.

With any of these options, if you use third party code as part of your project, you'll have to be aware of which convention it uses.

how to get the current working directory's absolute path from irb

This will give you the working directory of the current file.

File.dirname(__FILE__)

Example:

current_file: "/Users/nemrow/SITM/folder1/folder2/amazon.rb"

result: "/Users/nemrow/SITM/folder1/folder2"

Multiple WHERE Clauses with LINQ extension methods

You can continue chaining them like you've done.

results = results.Where (o => o.OrderStatus == OrderStatus.Open);
results = results.Where (o => o.InvoicePaid);

This represents an AND.

Cosine Similarity between 2 Number Lists

I did a benchmark based on several answers in the question and the following snippet is believed to be the best choice:

def dot_product2(v1, v2):
    return sum(map(operator.mul, v1, v2))


def vector_cos5(v1, v2):
    prod = dot_product2(v1, v2)
    len1 = math.sqrt(dot_product2(v1, v1))
    len2 = math.sqrt(dot_product2(v2, v2))
    return prod / (len1 * len2)

The result makes me surprised that the implementation based on scipy is not the fastest one. I profiled and find that cosine in scipy takes a lot of time to cast a vector from python list to numpy array.

enter image description here

Reloading .env variables without restarting server (Laravel 5, shared hosting)

A short solution:

use Dotenv;

with(new Dotenv(app()->environmentPath(), app()->environmentFile()))->overload();
with(new LoadConfiguration())->bootstrap(app());

In my case I needed to re-establish database connection after altering .env programmatically, but it didn't work , If you get into this trouble try this

app('db')->purge($connection->getName()); 

after reloading .env , that's because Laravel App could have accessed the default connection before and the \Illuminate\Database\DatabaseManager needs to re-read config parameters.

How do you rename a MongoDB database?

The above process is slow,you can use below method but you need to move collection by collection to another db.

use admin
db.runCommand({renameCollection: "[db_old_name].[collection_name]", to: "[db_new_name].[collection_name]"})

Can scrapy be used to scrape dynamic content from websites that are using AJAX?

yes, Scrapy can scrap dynamic websites, website that are rendered through javaScript.

There are Two approaches to scrapy these kind of websites.

First,

you can use splash to render Javascript code and then parse the rendered HTML. you can find the doc and project here Scrapy splash, git

Second,

As everyone is stating, by monitoring the network calls, yes, you can find the api call that fetch the data and mock that call in your scrapy spider might help you to get desired data.

What does "exited with code 9009" mean during this build?

It happens when you are missing some environment settings for using Microsoft Visual Studio x86 tools.
Therefore, try adding as a first command in your post-build steps:

For Visual Studio 2010 use:

call "$(DevEnvDir)..\Tools\vsvars32.bat"

As @FlorianKoch mentioned in comments, for VS 2017 use:

call "$(DevEnvDir)..\Tools\VsDevCmd.bat"

It should be placed before any other command.
It will set environment for using Microsoft Visual Studio x86 tools.

What is the simplest jQuery way to have a 'position:fixed' (always at top) div?

HTML/CSS Approach

If you are looking for an option that does not require much JavaScript (and and all the problems that come with it, such as rapid scroll event calls), it is possible to gain the same behavior by adding a wrapper <div> and a couple of styles. I noticed much smoother scrolling (no elements lagging behind) when I used the following approach:

JS Fiddle

HTML

<div id="wrapper">
  <div id="fixed">
    [Fixed Content]
  </div><!-- /fixed -->
  <div id="scroller">
    [Scrolling Content]
  </div><!-- /scroller -->
</div><!-- /wrapper -->

CSS

#wrapper { position: relative; }
#fixed { position: fixed; top: 0; right: 0; }
#scroller { height: 100px; overflow: auto; }

JS

//Compensate for the scrollbar (otherwise #fixed will be positioned over it).
$(function() {
  //Determine the difference in widths between
  //the wrapper and the scroller. This value is
  //the width of the scroll bar (if any).
  var offset = $('#wrapper').width() - $('#scroller').get(0).clientWidth;

  //Set the right offset
  $('#fixed').css('right', offset + 'px');?
});

Of course, this approach could be modified for scrolling regions that gain/lose content during runtime (which would result in addition/removal of scrollbars).

JavaScript ternary operator example with functions

The ternary style is generally used to save space. Semantically, they are identical. I prefer to go with the full if/then/else syntax because I don't like to sacrifice readability - I'm old-school and I prefer my braces.

The full if/then/else format is used for pretty much everything. It's especially popular if you get into larger blocks of code in each branch, you have a muti-branched if/else tree, or multiple else/ifs in a long string.

The ternary operator is common when you're assigning a value to a variable based on a simple condition or you are making multiple decisions with very brief outcomes. The example you cite actually doesn't make sense, because the expression will evaluate to one of the two values without any extra logic.

Good ideas:

this > that ? alert(this) : alert(that);  //nice and short, little loss of meaning

if(expression)  //longer blocks but organized and can be grasped by humans
{
    //35 lines of code here
}
else if (something_else)
{
    //40 more lines here
}
else if (another_one)  /etc, etc
{
    ...

Less good:

this > that ? testFucntion() ? thirdFunction() ? imlost() : whathappuh() : lostinsyntax() : thisisprobablybrokennow() ? //I'm lost in my own (awful) example by now.
//Not complete... or for average humans to read.

if(this != that)  //Ternary would be done by now
{
    x = this;
}
else
}
    x = this + 2;
}

A really basic rule of thumb - can you understand the whole thing as well or better on one line? Ternary is OK. Otherwise expand it.

Find when a file was deleted in Git

I've just added a solution here (is there a way in git to list all deleted files in the repository?) for finding the commits of deleted files by using a regexp:

git log --diff-filter=D --summary | sed -n '/^commit/h;/\/some_dir\//{G;s/\ncommit \(.*\)/ \1/gp}'

This returns everything deleted within a directory named some_dir (cascading). Any sed regexp there where \/some_dir\/ is will do.

OSX (thanks to @triplee and @keif)

git log --diff-filter=D --summary | sed -n -e '/^commit/h' -e '\:/:{' -e G -e 's/\ncommit \(.*\)/ \1/gp' -e }

What Does 'zoom' do in CSS?

As Joshua M pointed out, the zoom function isn't supported only in Firefox, but you can simply fix this as shown:

div.zoom {
  zoom: 2; /* all browsers */
 -moz-transform: scale(2);  /* Firefox */
}

How do I authenticate a WebClient request?

This helped me to call API that was using cookie authentication. I have passed authorization in header like this:

request.Headers.Set("Authorization", Utility.Helper.ReadCookie("AuthCookie"));

complete code:

// utility method to read the cookie value:
        public static string ReadCookie(string cookieName)
        {
            var cookies = HttpContext.Current.Request.Cookies;
            var cookie = cookies.Get(cookieName);
            if (cookie != null)
                return cookie.Value;
            return null;
        }

// using statements where you are creating your webclient
using System.Web.Script.Serialization;
using System.Net;
using System.IO;

// WebClient:

var requestUrl = "<API_url>";
var postRequest = new ClassRoom { name = "kushal seth" };

using (var webClient = new WebClient()) {
      JavaScriptSerializer serializer = new JavaScriptSerializer();
      byte[] requestData = Encoding.ASCII.GetBytes(serializer.Serialize(postRequest));
      HttpWebRequest request = WebRequest.Create(requestUrl) as HttpWebRequest;
      request.Method = "POST";
      request.ContentType = "application/json";                        
      request.ContentLength = requestData.Length;
      request.ContentType = "application/json";
      request.Expect = "application/json";
      request.Headers.Set("Authorization", Utility.Helper.ReadCookie("AuthCookie"));
      request.GetRequestStream().Write(requestData, 0, requestData.Length);

      using (var response = (HttpWebResponse)request.GetResponse()) {
         var reader = new StreamReader(response.GetResponseStream());
         var objText = reader.ReadToEnd(); // objText will have the value
      }
}


Java method to sum any number of ints

import java.util.Scanner;

public class SumAll {
    public static void sumAll(int arr[]) {//initialize method return sum
        int sum = 0;
        for (int i = 0; i < arr.length; i++) {
            sum += arr[i];
        }
        System.out.println("Sum is : " + sum);
    }

    public static void main(String[] args) {
        int num;
        Scanner input = new Scanner(System.in);//create scanner object 
        System.out.print("How many # you want to add : ");
        num = input.nextInt();//return num from keyboard
        int[] arr2 = new int[num];
        for (int i = 0; i < arr2.length; i++) {
            System.out.print("Enter Num" + (i + 1) + ": ");
            arr2[i] = input.nextInt();
        }
        sumAll(arr2);
    }

}

Adding Git-Bash to the new Windows Terminal

If you want to display an icon and are using a dark theme. Which means the icon provided above doesn't look that great. Then you can find the icon here

C:\Program Files\Git\mingw64\share\git\git-for-windows I copied it into.

%LOCALAPPDATA%\packages\Microsoft.WindowsTerminal_8wekyb3d8bbwe\RoamingState

and named it git-bash_32px as suggested above.

Control the opacity with CTRL + SHIFT + scrolling.

        {
            "acrylicOpacity" : 0.75,
            "closeOnExit" : true,
            "colorScheme" : "Campbell",
            "commandline" : "\"%PROGRAMFILES%\\git\\usr\\bin\\bash.exe\" -i -l",
            "cursorColor" : "#FFFFFF",
            "cursorShape" : "bar",
            "fontFace" : "Consolas",
            "fontSize" : 10,
            "guid" : "{73225108-7633-47ae-80c1-5d00111ef646}",
            "historySize" : 9001,
            "icon" : "ms-appdata:///roaming/git-bash_32px.ico",
            "name" : "Bash",
            "padding" : "0, 0, 0, 0",
            "snapOnInput" : true,
            "startingDirectory" : "%USERPROFILE%",
            "useAcrylic" : true
        },

How to implode array with key and value without foreach in PHP

There is also var_export and print_r more commonly known for printing debug output but both functions can take an optional argument to return a string instead.

Using the example from the question as data.

$array = ["item1"=>"object1", "item2"=>"object2","item-n"=>"object-n"];

Using print_r to turn the array into a string

This will output a human readable representation of the variable.

$string = print_r($array, true);
echo $string;

Will output:

Array
(
    [item1] => object1
    [item2] => object2
    [item-n] => object-n
)

Using var_export to turn the array into a string

Which will output a php string representation of the variable.

$string = var_export($array, true);
echo $string;

Will output:

array (
  'item1' => 'object1',
  'item2' => 'object2',
  'item-n' => 'object-n',
)

Because it is valid php we can evaluate it.

eval('$array2 = ' . var_export($array, true) . ';');
var_dump($array2 === $array);

Outputs:

bool(true)

How can I get the list of files in a directory using C or C++?

System call it!

system( "dir /b /s /a-d * > file_names.txt" );

Then just read the file.

EDIT: This answer should be considered a hack, but it really does work (albeit in a platform specific way) if you don't have access to more elegant solutions.

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

Essentially you want to add code to the Calculate event of the relevant Worksheet.

In the Project window of the VBA editor, double-click the sheet you want to add code to and from the drop-downs at the top of the editor window, choose 'Worksheet' and 'Calculate' on the left and right respectively.

Alternatively, copy the code below into the editor of the sheet you want to use:

Private Sub Worksheet_Calculate()

If Sheets("MySheet").Range("A1").Value > 0.5 Then
    MsgBox "Over 50%!", vbOKOnly
End If

End Sub

This way, every time the worksheet recalculates it will check to see if the value is > 0.5 or 50%.

How can I join multiple SQL tables using the IDs?

Simple INNER JOIN VIEW code....

CREATE VIEW room_view
AS SELECT a.*,b.*
FROM j4_booking a INNER JOIN j4_scheduling b
on a.room_id = b.room_id;

How can I override inline styles with external CSS?

<div style="background: red;">
    The inline styles for this div should make it red.
</div>

div[style] {
   background: yellow !important;
}

Below is the link for more details: http://css-tricks.com/override-inline-styles-with-css/

How do I rotate text in css?

I guess this is what you are looking for?

Added an example:

The html:

<div class="example-date">
  <span class="day">31</span> 
  <span class="month">July</span> 
  <span class="year">2009</span>
</div>

The css:

.year
{
    display:block;
    -webkit-transform: rotate(-90deg); 
    -moz-transform: rotate(-90deg); 
    filter: progid:DXImageTransform.Microsoft.BasicImage(rotation=3); //For IE support
}

Alle examples are from the mentioned site.

Image UriSource and Data Binding

you may use

ImageSourceConverter class

to get what you want

    img1.Source = (ImageSource)new ImageSourceConverter().ConvertFromString("/Assets/check.png");

sendUserActionEvent() is null

Same issue on a Galaxy Tab and on a Xperia S, after uninstall and install again it seems that disappear.

The code that suddenly appear to raise this problem is this:

public void unlockMainActivity() {
    SharedPreferences prefs = getSharedPreferences("CALCULATOR_PREFS", 0);
    boolean hasCode = prefs.getBoolean("HAS_CODE", false);
    Context context = this.getApplicationContext();
    Intent intent = null;

    if (!hasCode) {
        intent = new Intent(context, WellcomeActivity.class);
    } else {
        intent = new Intent(context, CalculatingActivity.class);
    }
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    (context).startActivity(intent);
}

jQuery - Illegal invocation

Also this is a cause too: If you built a jQuery collection (via .map() or something similar) then you shouldn't use this collection in .ajax()'s data. Because it's still a jQuery object, not plain JavaScript Array. You should use .get() at the and to get plain js array and should use it on the data setting on .ajax().

How do I embed PHP code in JavaScript?

Here is an example:

html_code +="<td>" +
            "<select name='[row"+count+"]' data-placeholder='Choose One...' class='chosen-select form-control' tabindex='2'>"+
                "<option selected='selected' disabled='disabled' value=''>Select Exam Name</option>"+
                "<?php foreach($NM_EXAM as $ky=>$row) {
                echo '<option value='."$row->EXAM_ID". '>' . $row->EXAM_NAME . '</option>';
               } ?>"+
            "</select>"+
        "</td>";

Or

echo '<option value=\"'.$row->EXAM_ID. '\">' . $row->EXAM_NAME . '</option>';

JavaScript or jQuery browser back button click detector

In my case I am using jQuery .load() to update DIVs in a SPA (single page [web] app) .

Being new to working with $(window).on('hashchange', ..) event listener , this one proved challenging and took a bit to hack on. Thanks to reading a lot of answers and trying different variations, finally figured out how to make it work in the following manner. Far as I can tell, it is looking stable so far.

In summary - there is the variable globalCurrentHash that should be set each time you load a view.

Then when $(window).on('hashchange', ..) event listener runs, it checks the following:

  • If location.hash has the same value, it means Going Forward
  • If location.hash has different value, it means Going Back

I realize using global vars isn't the most elegant solution, but doing things OO in JS seems tricky to me so far. Suggestions for improvement/refinement certainly appreciated


Set Up:

  1. Define a global var :
    var globalCurrentHash = null;
  1. When calling .load() to update the DIV, update the global var as well :

    function loadMenuSelection(hrefVal) {
      $('#layout_main').load(nextView);
      globalCurrentHash = hrefVal;
    }
    
  2. On page ready, set up the listener to check the global var to see if Back Button is being pressed:

    $(document).ready(function(){
      $(window).on('hashchange', function(){
          console.log( 'location.hash: ' + location.hash );
          console.log( 'globalCurrentHash: ' + globalCurrentHash );
    
          if (location.hash == globalCurrentHash) {
              console.log( 'Going fwd' );
          }
          else {
    
              console.log( 'Going Back' );
              loadMenuSelection(location.hash);
          }
        });
    
    });
    

What are the lesser known but useful data structures?

Splash Tables are great. They're like a normal hash table, except they guarantee constant-time lookup and can handle 90% utilization without losing performance. They're a generalization of the Cuckoo Hash (also a great data structure). They do appear to be patented, but as with most pure software patents I wouldn't worry too much.

How do I implement JQuery.noConflict() ?

If you look at the examples on the api page there is this: Example: Creates a different alias instead of jQuery to use in the rest of the script.

var j = jQuery.noConflict();
// Do something with jQuery
j("div p").hide();
// Do something with another library's $()
$("content").style.display = 'none';

Put the var j = jQuery.noConflict() after you bring in jquery and then bring in the conflicting scripts. You can then use the j in place of $ for all your jquery needs and use the $ for the other script.

Convert .class to .java

This is for Mac users:

first of all you have to clarify where the class file is... so for example, in 'Terminal' (A Mac Application) you would type:

cd

then wherever you file is e.g:

cd /Users/CollarBlast/Desktop/JavaFiles/

then you would hit enter. After that you would do the command. e.g:

cd /Users/CollarBlast/Desktop/JavaFiles/ (then i would press enter...)

Then i would type the command:

javap -c JavaTestClassFile.class (then i would press enter again...)

and hopefully it should work!

How do I set a textbox's value using an anchor with jQuery?

I wrote this code snippet and it works fine:

<a href="#" class="clickable">Blah</a>
<input id="textbox">
<script type="text/javascript">
    $(document).ready(function(){
        $("a.clickable").click(function(event){
            event.preventDefault();
            $("input#textbox").val($(this).html());
        });  
    });
</script>

Maybe you forgot to give a class name "clickable" to your links?

Web Application Problems (web.config errors) HTTP 500.19 with IIS7.5 and ASP.NET v2

This lovely detailed error is still present in 2019! I just want to add that if your web.config is valid and accessible it most likely is a dependency issue.

As mentioned by the OP it was a AJAX module, and as by others commonly the Rewrite module. Just keep your eyes open in your web.config what modules and libraries your tags are referencing to since the error code 0x8007000d can be about ANY dependency.

In my case I didn't realize the AspNetCore bundle was missing and had to be installed! So happy I found this post!!

Fatal error: Call to a member function query() on null

put this line in parent construct : $this->load->database();

function  __construct() {
    parent::__construct();
    $this->load->library('lib_name');
    $model=array('model_name');
    $this->load->model($model);
    $this->load->database();
}

this way.. it should work..

How do I use properly CASE..WHEN in MySQL

CASE case_value
    WHEN when_value THEN statements
    [WHEN when_value THEN statements]
    ELSE statements
END 

Or:

CASE
WHEN <search_condition> THEN statements
[WHEN <search_condition> THEN statements] 
ELSE statements
END 

here CASE is an expression in 2nd scenario search_condition will evaluate and if no search_condition is equal then execute else

SELECT
   CASE course_enrollment_settings.base_price
    WHEN course_enrollment_settings.base_price = 0      THEN 1

should be

SELECT
   CASE 
    WHEN course_enrollment_settings.base_price = 0      THEN 1

How to pass multiple parameters in json format to a web service using jquery?

This is a stab in the dark, but maybe do you need to wrap your JSON arguments; like say something like this:

data: "{'Ids':[{'Id1':'2'},{'Id2':'2'}]}"

Make sure your JSON is properly formed?

Position a CSS background image x pixels from the right?

Better for all background: url('../images/bg-menu-dropdown-top.png') left 20px top no-repeat !important;

Setting mime type for excel document

I was setting MIME type from .NET code as below -

File(generatedFileName, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")

My application generates excel using OpenXML SDK. This MIME type worked -

vnd.openxmlformats-officedocument.spreadsheetml.sheet

How to maintain aspect ratio using HTML IMG tag

With css:

.img {
    display:table-cell;
    max-width:...px;
    max-height:...px;
    width:100%;
}

Python datetime strptime() and strftime(): how to preserve the timezone information

Unfortunately, strptime() can only handle the timezone configured by your OS, and then only as a time offset, really. From the documentation:

Support for the %Z directive is based on the values contained in tzname and whether daylight is true. Because of this, it is platform-specific except for recognizing UTC and GMT which are always known (and are considered to be non-daylight savings timezones).

strftime() doesn't officially support %z.

You are stuck with python-dateutil to support timezone parsing, I am afraid.

forEach loop Java 8 for Map entry set

String ss = "Pawan kavita kiyansh Patidar Patidar";
    StringBuilder ress = new StringBuilder();
    
    Map<Character, Integer> fre = ss.chars().boxed()
            .collect(Collectors.toMap(k->Character.valueOf((char) k.intValue()),k->1,Integer::sum));
    
      //fre.forEach((k, v) -> System.out.println((k + ":" + v)));
    
    fre.entrySet().forEach(e ->{
            //System.out.println(e.getKey() + ":" + e.getValue());
            //ress.append(String.valueOf(e.getKey())+e.getValue());
        }); 

    fre.forEach((k,v)->{
        //System.out.println("Item : " + k + " Count : " + v);
        ress.append(String.valueOf(k)+String.valueOf(v));
    });
    
    System.out.println(ress.toString());

C++ queue - simple example

std::queue<myclass*> my_queue; will do the job.

See here for more information on this container.

Rounding to two decimal places in Python 2.7?

print "financial return of outcome 1 = $%.2f" % (out1)

SQL Server, How to set auto increment after creating a table without data loss?

Changing the IDENTITY property is really a metadata only change. But to update the metadata directly requires starting the instance in single user mode and messing around with some columns in sys.syscolpars and is undocumented/unsupported and not something I would recommend or will give any additional details about.

For people coming across this answer on SQL Server 2012+ by far the easiest way of achieving this result of an auto incrementing column would be to create a SEQUENCE object and set the next value for seq as the column default.

Alternatively, or for previous versions (from 2005 onwards), the workaround posted on this connect item shows a completely supported way of doing this without any need for size of data operations using ALTER TABLE...SWITCH. Also blogged about on MSDN here. Though the code to achieve this is not very simple and there are restrictions - such as the table being changed can't be the target of a foreign key constraint.

Example code.

Set up test table with no identity column.

CREATE TABLE dbo.tblFoo 
(
bar INT PRIMARY KEY,
filler CHAR(8000),
filler2 CHAR(49)
)


INSERT INTO dbo.tblFoo (bar)
SELECT TOP (10000) ROW_NUMBER() OVER (ORDER BY (SELECT 0))
FROM master..spt_values v1, master..spt_values v2

Alter it to have an identity column (more or less instant).

BEGIN TRY;
    BEGIN TRANSACTION;

    /*Using DBCC CHECKIDENT('dbo.tblFoo') is slow so use dynamic SQL to
      set the correct seed in the table definition instead*/
    DECLARE @TableScript nvarchar(max)
    SELECT @TableScript = 
    '
    CREATE TABLE dbo.Destination(
        bar INT IDENTITY(' + 
                     CAST(ISNULL(MAX(bar),0)+1 AS VARCHAR) + ',1)  PRIMARY KEY,
        filler CHAR(8000),
        filler2 CHAR(49)
        )

        ALTER TABLE dbo.tblFoo SWITCH TO dbo.Destination;
    '       
    FROM dbo.tblFoo
    WITH (TABLOCKX,HOLDLOCK)

    EXEC(@TableScript)


    DROP TABLE dbo.tblFoo;

    EXECUTE sp_rename N'dbo.Destination', N'tblFoo', 'OBJECT';


    COMMIT TRANSACTION;
END TRY
BEGIN CATCH
    IF XACT_STATE() <> 0 ROLLBACK TRANSACTION;
    PRINT ERROR_MESSAGE();
END CATCH;

Test the result.

INSERT INTO dbo.tblFoo (filler,filler2) 
OUTPUT inserted.*
VALUES ('foo','bar')

Gives

bar         filler    filler2
----------- --------- ---------
10001       foo       bar      

Clean up

DROP TABLE dbo.tblFoo

Using if(isset($_POST['submit'])) to not display echo when script is open is not working

Whats wrong in this?

<form class="navbar-form navbar-right" method="post" action="login.php">
  <div class="form-group">
    <input type="email" name="email" class="form-control" placeholder="email">
    <input type="password" name="password" class="form-control" placeholder="password">
  </div>
  <input type="submit" name="submit" value="submit" class="btn btn-success">
</form>

login.php

if(isset($_POST['submit']) && !empty($_POST['submit'])) {
  // if (!logged_in()) 
  echo 'asodj';
}

SQL Server IIF vs CASE

IIF is a non-standard T-SQL function. It was added to SQL SERVER 2012, so that Access could migrate to SQL Server without refactoring the IIF's to CASE before hand. Once the Access db is fully migrated into SQL Server, you can refactor.

Strip off URL parameter with PHP

This should do it:

public function removeQueryParam(string $url, string $param): string
{
    $parsedUrl = parse_url($url);

    if (isset($parsedUrl[$param])) {
        $baseUrl = strtok($url, '?');
        parse_str(parse_url($url)['query'], $query);
        unset($query[$param]);
        return sprintf('%s?%s',
            $baseUrl,
            http_build_query($query)
        );
    }

    return $url;
}

Injecting @Autowired private field during testing

I believe in order to have auto-wiring work on your MyLauncher class (for myService), you will need to let Spring initialize it instead of calling the constructor, by auto-wiring myLauncher. Once that is being auto-wired (and myService is also getting auto-wired), Spring (1.4.0 and up) provides a @MockBean annotation you can put in your test. This will replace a matching single beans in context with a mock of that type. You can then further define what mocking you want, in a @Before method.

public class MyLauncherTest
    @MockBean
    private MyService myService;

    @Autowired
    private MyLauncher myLauncher;

    @Before
    private void setupMockBean() {
        doNothing().when(myService).someVoidMethod();
        doReturn("Some Value").when(myService).someStringMethod();
    }

    @Test
    public void someTest() {
        myLauncher.doSomething();
    }
}

Your MyLauncher class can then remain unmodified, and your MyService bean will be a mock whose methods return values as you defined:

@Component
public class MyLauncher {
    @Autowired
    MyService myService;

    public void doSomething() {
        myService.someVoidMethod();
        myService.someMethodThatCallsSomeStringMethod();
    }

    //other methods
}

A couple advantages of this over other methods mentioned is that:

  1. You don't need to manually inject myService.
  2. You don't need use the Mockito runner or rules.

find filenames NOT ending in specific extensions on Unix?

find . ! \( -name "*.exe" -o -name "*.dll" \)

How to change the remote repository for a git submodule?

Just edit your .git/config file. For example; if you have a "common" submodule you can do this in the super-module:

git config submodule.common.url /data/my_local_common

Batch file to copy directories recursively

After reading the accepted answer's comments, I tried the robocopy command, which worked for me (using the standard command prompt from Windows 7 64 bits SP 1):

robocopy source_dir dest_dir /s /e

Selecting element by data attribute with jQuery

For people Googling and want more general rules about selecting with data-attributes:

$("[data-test]") will select any element that merely has the data attribute (no matter the value of the attribute). Including:

<div data-test=value>attributes with values</div>
<div data-test>attributes without values</div>

$('[data-test~="foo"]') will select any element where the data attribute contains foo but doesn't have to be exact, such as:

<div data-test="foo">Exact Matches</div>
<div data-test="this has the word foo">Where the Attribute merely contains "foo"</div>

$('[data-test="the_exact_value"]') will select any element where the data attribute exact value is the_exact_value, for example:

<div data-test="the_exact_value">Exact Matches</div>

but not

<div data-test="the_exact_value foo">This won't match</div>

Which is the preferred way to concatenate a string in Python?

As @jdi mentions Python documentation suggests to use str.join or io.StringIO for string concatenation. And says that a developer should expect quadratic time from += in a loop, even though there's an optimisation since Python 2.4. As this answer says:

If Python detects that the left argument has no other references, it calls realloc to attempt to avoid a copy by resizing the string in place. This is not something you should ever rely on, because it's an implementation detail and because if realloc ends up needing to move the string frequently, performance degrades to O(n^2) anyway.

I will show an example of real-world code that naively relied on += this optimisation, but it didn't apply. The code below converts an iterable of short strings into bigger chunks to be used in a bulk API.

def test_concat_chunk(seq, split_by):
    result = ['']
    for item in seq:
        if len(result[-1]) + len(item) > split_by: 
            result.append('')
        result[-1] += item
    return result

This code can literary run for hours because of quadratic time complexity. Below are alternatives with suggested data structures:

import io

def test_stringio_chunk(seq, split_by):
    def chunk():
        buf = io.StringIO()
        size = 0
        for item in seq:
            if size + len(item) <= split_by:
                size += buf.write(item)
            else:
                yield buf.getvalue()
                buf = io.StringIO()
                size = buf.write(item)
        if size:
            yield buf.getvalue()

    return list(chunk())

def test_join_chunk(seq, split_by):
    def chunk():
        buf = []
        size = 0
        for item in seq:
            if size + len(item) <= split_by:
                buf.append(item)
                size += len(item)
            else:
                yield ''.join(buf)                
                buf.clear()
                buf.append(item)
                size = len(item)
        if size:
            yield ''.join(buf)

    return list(chunk())

And a micro-benchmark:

import timeit
import random
import string
import matplotlib.pyplot as plt

line = ''.join(random.choices(
    string.ascii_uppercase + string.digits, k=512)) + '\n'
x = []
y_concat = []
y_stringio = []
y_join = []
n = 5
for i in range(1, 11):
    x.append(i)
    seq = [line] * (20 * 2 ** 20 // len(line))
    chunk_size = i * 2 ** 20
    y_concat.append(
        timeit.timeit(lambda: test_concat_chunk(seq, chunk_size), number=n) / n)
    y_stringio.append(
        timeit.timeit(lambda: test_stringio_chunk(seq, chunk_size), number=n) / n)
    y_join.append(
        timeit.timeit(lambda: test_join_chunk(seq, chunk_size), number=n) / n)
plt.plot(x, y_concat)
plt.plot(x, y_stringio)
plt.plot(x, y_join)
plt.legend(['concat', 'stringio', 'join'], loc='upper left')
plt.show()

micro-benchmark

How do I update the element at a certain position in an ArrayList?

 arrList.set(5,newValue);

and if u want to update it then add this line also

 youradapater.NotifyDataSetChanged();

How to get xdebug var_dump to show full object/array

I know this is late but it might be of some use:

echo "<pre>";
print_r($array);
echo "</pre>";

How to "Open" and "Save" using java

You may also want to consider the possibility of using SWT (another Java GUI library). Pros and cons of each are listed at:

Java Desktop application: SWT vs. Swing

Steps to upload an iPhone application to the AppStore

Check that your singing identity IN YOUR TARGET properties is correct. This one over-rides what you have in your project properties.

Also: I dunno if this is true - but I wasn't getting emails detailing my binary rejections when I did the "ready for binary upload" from a PC - but I DID get an email when I did this on the MAC

"could not find stored procedure"

If the error message only occurs locally, try opening the sql file and press the play button.

CSS align one item right with flexbox

For a terse, pure flexbox option, group the left-aligned items and the right-aligned items:

<div class="wrap">
  <div>
    <span>One</span>
    <span>Two</span>
  </div>
  <div>Three</div>
</div>

and use space-between:

.wrap {
  display: flex;
  background: #ccc;
  justify-content: space-between;
}

This way you can group multiple items to the right(or just one).

https://jsfiddle.net/c9mkewwv/3/

Can't find keyplane that supports type 4 for keyboard iPhone-Portrait-NumberPad; using 3876877096_Portrait_iPhone-Simple-Pad_Default

In your iOS App can't find a Numeric Keypad attached to your OS X. So you just need to Uncheck connect Hardware Keyboard option in your Simulator, in the following path just for testing purpose:

Simulator -> Hardware -> Keyboard -> Connect Hardware Keyboard

This will resolve the above issue.

I think you should see the below link too. It says it's a bug in the XCode at the end of that Forum post thread!

Reference

How to check a radio button with jQuery?

I used jquery-1.11.3.js

Basic Enable & disable

Tips 1: (Radio button type common Disable & Enable)

$("input[type=radio]").attr('disabled', false);
$("input[type=radio]").attr('disabled', true); 

Tips 2: ( ID selector Using prop() or attr())

$("#paytmradio").prop("checked", true);
$("#sbiradio").prop("checked", false);

jQuery("#paytmradio").attr('checked', 'checked'); // or true this won't work
jQuery("#sbiradio").attr('checked', false);

Tips 3: ( Class selector Using prop() or arrt())

$(".paytm").prop("checked", true);
$(".sbi").prop("checked", false);

jQuery(".paytm").attr('checked', 'checked'); // or true
jQuery(".sbi").attr('checked', false);

OTHER TIPS

$("#paytmradio").is(":checked")   // Checking is checked or not
$(':radio:not(:checked)').attr('disabled', true); // All not check radio button disabled

$('input[name=payment_type][value=1]').attr('checked', 'checked'); //input type via checked
 $("input:checked", "#paytmradio").val() // get the checked value

index.html

<div class="col-md-6">      
    <label class="control-label" for="paymenttype">Payment Type <span style="color:red">*</span></label>
    <div id="paymenttype" class="form-group" style="padding-top: inherit;">
        <label class="radio-inline" class="form-control"><input  type="radio" id="paytmradio"  class="paytm" name="paymenttype" value="1" onclick="document.getElementById('paymentFrm').action='paytmTest.php';">PayTM</label>
        <label class="radio-inline" class="form-control"><input  type="radio" id="sbiradio" class="sbi" name="paymenttype" value="2" onclick="document.getElementById('paymentFrm').action='sbiTest.php';">SBI ePAY</label>
    </div>
</div>

How to set max width of an image in CSS

Your css is almost correct. You are just missing display: block; in image css. Also one typo in your id. It should be <div id="ImageContainer">

_x000D_
_x000D_
img.Image { max-width: 100%; display: block; }_x000D_
div#ImageContainer { width: 600px; }
_x000D_
<div id="ImageContainer">_x000D_
    <img src="http://placehold.it/1000x600" class="Image">_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to send email attachments?

from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
import smtplib
import mimetypes
import email.mime.application

smtp_ssl_host = 'smtp.gmail.com'  # smtp.mail.yahoo.com
smtp_ssl_port = 465
s = smtplib.SMTP_SSL(smtp_ssl_host, smtp_ssl_port)
s.login(email_user, email_pass)


msg = MIMEMultipart()
msg['Subject'] = 'I have a picture'
msg['From'] = email_user
msg['To'] = email_user

txt = MIMEText('I just bought a new camera.')
msg.attach(txt)

filename = 'introduction-to-algorithms-3rd-edition-sep-2010.pdf' #path to file
fo=open(filename,'rb')
attach = email.mime.application.MIMEApplication(fo.read(),_subtype="pdf")
fo.close()
attach.add_header('Content-Disposition','attachment',filename=filename)
msg.attach(attach)
s.send_message(msg)
s.quit()

For explanation, you can use this link it explains properly https://medium.com/@sdoshi579/to-send-an-email-along-with-attachment-using-smtp-7852e77623

How to get text box value in JavaScript

<!DOCTYPE html>
<html>
<body>
<label>Enter your Name here: </label><br>
<input type= text id="namehere" onchange="displayname()"><br>


<script>
function displayname() {
    document.getElementById("demo").innerHTML = 
document.getElementById("namehere").value;
}

</script>


<p id="demo"></p>

</body>
</html> 

Vagrant ssh authentication failure

Run the following commands in guest machine/VM:

wget https://raw.githubusercontent.com/mitchellh/vagrant/master/keys/vagrant.pub -O ~/.ssh/authorized_keys
chmod 700 ~/.ssh
chmod 600 ~/.ssh/authorized_keys
chown -R vagrant:vagrant ~/.ssh

Then do vagrant halt. This will remove and regenerate your private keys.

(These steps assume you have already created or already have the ~/.ssh/ and ~/.ssh/authorized_keys directories under your home folder.)

CSS3 transform: rotate; in IE9

Standard CSS3 rotate should work in IE9, but I believe you need to give it a vendor prefix, like so:

  -ms-transform: rotate(10deg);

It is possible that it may not work in the beta version; if not, try downloading the current preview version (preview 7), which is a later revision that the beta. I don't have the beta version to test against, so I can't confirm whether it was in that version or not. The final release version is definitely slated to support it.

I can also confirm that the IE-specific filter property has been dropped in IE9.

[Edit]
People have asked for some further documentation. As they say, this is quite limited, but I did find this page: http://css3please.com/ which is useful for testing various CSS3 features in all browsers.

But testing the rotate feature on this page in IE9 preview caused it to crash fairly spectacularly.

However I have done some independant tests using -ms-transform:rotate() in IE9 in my own test pages, and it is working fine. So my conclusion is that the feature is implemented, but has got some bugs, possibly related to setting it dynamically.

Another useful reference point for which features are implemented in which browsers is www.canIuse.com -- see http://caniuse.com/#search=rotation

[EDIT]
Reviving this old answer because I recently found out about a hack called CSS Sandpaper which is relevant to the question and may make things easier.

The hack implements support for the standard CSS transform for for old versions of IE. So now you can add the following to your CSS:

-sand-transform: rotate(10deg);

...and have it work in IE 6/7/8, without having to use the filter syntax. (of course it still uses the filter syntax behind the scenes, but this makes it a lot easier to manage because it's using similar syntax to other browsers)

PHP: Convert any string to UTF-8 without knowing the original character set, or at least try

If you're willing to "take this to the console", I'd recommend enca. Unlike the rather simplistic mb_detect_encoding, it uses "a mixture of parsing, statistical analysis, guessing and black magic to determine their encodings" (lol - see man page). However, you usually have to pass the language of the input file if you want to detect such country-specific encodings. (However, mb_detect_encoding essentially has the same requirement, as the encoding would have to appear "in the right place" in the list of passed encodings for it to be detectable at all.)

enca also came up here: How to find encoding of a file in Unix via script(s)

Whats the CSS to make something go to the next line in the page?

Have the element display as a block:

display: block;

In android how to set navigation drawer header image and name programmatically in class file?

Here is the method you can use to get header view and set data accourdingly

val headerView: View? = navigationView.getHeaderView(0) // Index of the added headerView  

// Now you can access child views of the header view
val titleTextView: TextView? = headerView?.findViewById(R.id.titleTextView)

Creating a dictionary from a CSV file

I'd suggest adding if rows in case there is an empty line at the end of the file

import csv
with open('coors.csv', mode='r') as infile:
    reader = csv.reader(infile)
    with open('coors_new.csv', mode='w') as outfile:
        writer = csv.writer(outfile)
        mydict = dict(row[:2] for row in reader if row)

How do I completely remove root password

Did you try passwd -d root? Most likely, this will do what you want.


You can also manually edit /etc/shadow: (Create a backup copy. Be sure that you can log even if you mess up, for example from a rescue system.) Search for "root". Typically, the root entry looks similar to

root:$X$SK5xfLB1ZW:0:0...

There, delete the second field (everything between the first and second colon):

root::0:0...

Some systems will make you put an asterisk (*) in the password field instead of blank, where a blank field would allow no password (CentOS 8 for example)

root:*:0:0...

Save the file, and try logging in as root. It should skip the password prompt. (Like passwd -d, this is a "no password" solution. If you are really looking for a "blank password", that is "ask for a password, but accept if the user just presses Enter", look at the manpage of mkpasswd, and use mkpasswd to create the second field for the /etc/shadow.)

Automatic date update in a cell when another cell's value changes (as calculated by a formula)

You could fill the dependend cell (D2) by a User Defined Function (VBA Macro Function) that takes the value of the C2-Cell as input parameter, returning the current date as ouput.

Having C2 as input parameter for the UDF in D2 tells Excel that it needs to reevaluate D2 everytime C2 changes (that is if auto-calculation of formulas is turned on for the workbook).

EDIT:

Here is some code:

For the UDF:

    Public Function UDF_Date(ByVal data) As Date

        UDF_Date = Now()

    End Function

As Formula in D2:

=UDF_Date(C2)

You will have to give the D2-Cell a Date-Time Format, or it will show a numeric representation of the date-value.

And you can expand the formula over the desired range by draging it if you keep the C2 reference in the D2-formula relative.

Note: This still might not be the ideal solution because every time Excel recalculates the workbook the date in D2 will be reset to the current value. To make D2 only reflect the last time C2 was changed there would have to be some kind of tracking of the past value(s) of C2. This could for example be implemented in the UDF by providing also the address alonside the value of the input parameter, storing the input parameters in a hidden sheet, and comparing them with the previous values everytime the UDF gets called.

Addendum:

Here is a sample implementation of an UDF that tracks the changes of the cell values and returns the date-time when the last changes was detected. When using it, please be aware that:

  • The usage of the UDF is the same as described above.

  • The UDF works only for single cell input ranges.

  • The cell values are tracked by storing the last value of cell and the date-time when the change was detected in the document properties of the workbook. If the formula is used over large datasets the size of the file might increase considerably as for every cell that is tracked by the formula the storage requirements increase (last value of cell + date of last change.) Also, maybe Excel is not capable of handling very large amounts of document properties and the code might brake at a certain point.

  • If the name of a worksheet is changed all the tracking information of the therein contained cells is lost.

  • The code might brake for cell-values for which conversion to string is non-deterministic.

  • The code below is not tested and should be regarded only as proof of concept. Use it at your own risk.

    Public Function UDF_Date(ByVal inData As Range) As Date
    
        Dim wb As Workbook
        Dim dProps As DocumentProperties
        Dim pValue As DocumentProperty
        Dim pDate As DocumentProperty
        Dim sName As String
        Dim sNameDate As String
    
        Dim bDate As Boolean
        Dim bValue As Boolean
        Dim bChanged As Boolean
    
        bDate = True
        bValue = True
    
        bChanged = False
    
    
        Dim sVal As String
        Dim dDate As Date
    
        sName = inData.Address & "_" & inData.Worksheet.Name
        sNameDate = sName & "_dat"
    
        sVal = CStr(inData.Value)
        dDate = Now()
    
        Set wb = inData.Worksheet.Parent
    
        Set dProps = wb.CustomDocumentProperties
    
    On Error Resume Next
    
        Set pValue = dProps.Item(sName)
    
        If Err.Number <> 0 Then
            bValue = False
            Err.Clear
        End If
    
    On Error GoTo 0
    
        If Not bValue Then
            bChanged = True
            Set pValue = dProps.Add(sName, False, msoPropertyTypeString, sVal)
        Else
            bChanged = pValue.Value <> sVal
            If bChanged Then
                pValue.Value = sVal
            End If
        End If
    
    On Error Resume Next
    
        Set pDate = dProps.Item(sNameDate)
    
        If Err.Number <> 0 Then
            bDate = False
            Err.Clear
        End If
    
    On Error GoTo 0
    
        If Not bDate Then
            Set pDate = dProps.Add(sNameDate, False, msoPropertyTypeDate, dDate)
        End If
    
        If bChanged Then
            pDate.Value = dDate
        Else
            dDate = pDate.Value
        End If
    
    
        UDF_Date = dDate
     End Function
    

Make the insertion of the date conditional upon the range.

This has an advantage of not changing the dates unless the content of the cell is changed, and it is in the range C2:C2, even if the sheet is closed and saved, it doesn't recalculate unless the adjacent cell changes.

Adapted from this tip and @Paul S answer

Private Sub Worksheet_Change(ByVal Target As Range)
 Dim R1 As Range
 Dim R2 As Range
 Dim InRange As Boolean
    Set R1 = Range(Target.Address)
    Set R2 = Range("C2:C20")
    Set InterSectRange = Application.Intersect(R1, R2)

  InRange = Not InterSectRange Is Nothing
     Set InterSectRange = Nothing
   If InRange = True Then
     R1.Offset(0, 1).Value = Now()
   End If
     Set R1 = Nothing
     Set R2 = Nothing
 End Sub

The project type is not supported by this installation

Open up the .csproj file for your solution in wordpad or some text editor. Look for the ProjectTypeGuids. They indicate the required supported types for your solutions. Search the internet these GUIDs to find out what they require. For example E53F8FEA-EAE0-44A6-8774-FFD645390401 means it requires "MVC 3.0"