Programs & Examples On #File encodings

In communications and Information processing, file-encoding is the process by which information from a source is converted into symbols to be communicated.The tag file-encoding refers to programming related questions belongs to various encoding schemes for file formats.

NameError: name 'self' is not defined

If you have arrived here via google, please make sure to check that you have given self as the first parameter to a class function. Especially if you try to reference values for that object instance inside the class function.

def foo():
    print(self.bar)

>NameError: name 'self' is not defined

def foo(self):
    print(self.bar)

Iterating through all nodes in XML file

To iterate through all elements

XDocument xdoc = XDocument.Load("input.xml");
foreach (XElement element in xdoc.Descendants())
{
    Console.WriteLine(element.Name);
}

Apache POI Excel - how to configure columns to be expanded?

Its very simple, use this one line code dataSheet.autoSizeColumn(0)

or give the number of column in bracket dataSheet.autoSizeColumn(cell number )

Convert JSON array to an HTML table in jQuery

Modified a bit code of @Dr.sai 's code. Hope this will be useful.

(function ($) {
    /**
     * data - array of record
     * hidecolumns, array of fields to hide
     * usage : $("selector").generateTable(json, ['field1', 'field5']);
     */
    'use strict';
    $.fn.generateTable = function (data, hidecolumns) {
        if ($.isArray(data) === false) {
            console.log('Invalid Data');
            return;
        }
        var container = $(this),
            table = $('<table>'),
            tableHead = $('<thead>'),       
            tableBody = $('<tbody>'),       
            tblHeaderRow = $('<tr>');       

        $.each(data, function (index, value) {
            var tableRow = $('<tr>').addClass(index%2 === 0 ? 'even' : 'odd');      
            $.each(value, function (key, val) {
                if (index == 0 && $.inArray(key, hidecolumns) <= -1 ) { 
                    var theaddata = $('<th>').text(key);
                    tblHeaderRow.append(theaddata); 
                }
                if ($.inArray(key, hidecolumns) <= -1 ) { 
                    var tbodydata = $('<td>').text(val);
                    tableRow.append(tbodydata);     
                }
            });
            $(tableBody).append(tableRow);  
        });
        $(tblHeaderRow).appendTo(tableHead);
        tableHead.appendTo(table);      
        tableBody.appendTo(table);
        $(this).append(table);    
        return this;
    };
})(jQuery);

Hoping this will be helpful to hide some columns too. Link to file

How do I check to see if my array includes an object?

This ...

horse = Horse.find(:first,:offset=>rand(Horse.count))
unless @suggested_horses.exists?(horse.id)
   @suggested_horses<< horse
end

Should probably be this ...

horse = Horse.find(:first,:offset=>rand(Horse.count))
unless @suggested_horses.include?(horse)
   @suggested_horses<< horse
end

How to make a GridLayout fit screen size

Giving match_parent to inflated items will do the trick. GridLayout will automatically divide max parent length based on given column number and inflate those items fitting the whole screen.give match_parent to the item

How can I create a small color box using html and css?

You can create these easily using the floating ability of CSS, for example. I have created a small example on Jsfiddle over here, all the related css and html is also provided there.

_x000D_
_x000D_
.foo {_x000D_
  float: left;_x000D_
  width: 20px;_x000D_
  height: 20px;_x000D_
  margin: 5px;_x000D_
  border: 1px solid rgba(0, 0, 0, .2);_x000D_
}_x000D_
_x000D_
.blue {_x000D_
  background: #13b4ff;_x000D_
}_x000D_
_x000D_
.purple {_x000D_
  background: #ab3fdd;_x000D_
}_x000D_
_x000D_
.wine {_x000D_
  background: #ae163e;_x000D_
}
_x000D_
<div class="foo blue"></div>_x000D_
<div class="foo purple"></div>_x000D_
<div class="foo wine"></div>
_x000D_
_x000D_
_x000D_

Multithreading in Bash

Sure, just add & after the command:

read_cfg cfgA &
read_cfg cfgB &
read_cfg cfgC &
wait

all those jobs will then run in the background simultaneously. The optional wait command will then wait for all the jobs to finish.

Each command will run in a separate process, so it's technically not "multithreading", but I believe it solves your problem.

Finding smallest value in an array most efficiently

If they are unsorted, you can't do much but look at each one, which is O(N), and when you're done you'll know the minimum.


Pseudo-code:

small = <biggest value> // such as std::numerical_limits<int>::max
for each element in array:
    if (element < small)
        small = element

A better way reminded by Ben to me was to just initialize small with the first element:

small = element[0]
for each element in array, starting from 1 (not 0):
    if (element < small)
        small = element

The above is wrapped in the algorithm header as std::min_element.


If you can keep your array sorted as items are added, then finding it will be O(1), since you can keep the smallest at front.

That's as good as it gets with arrays.

How to kill an Android activity when leaving it so that it cannot be accessed from the back button?

Finally, I got a solution!

My Context is:- I want disconnect socket connection when activity destroyed, I tried to finish() activity but it didn't work me, its keep connection live somewhere.

so I use android.os.Process.killProcess(android.os.Process.myPid()); its kill my activity and i used android:excludeFromRecents="true" for remove from recent activity .

How to have a transparent ImageButton: Android

This is programatically set background color as transparent

 ImageButton btn=(ImageButton)findViewById(R.id.ImageButton01);
 btn.setBackgroundColor(Color.TRANSPARENT);

c++ array - expression must have a constant value

The standard requires the array length to be a value that is computable at compile time so that the compiler is able to allocate enough space on the stack. In your case, you are trying to set the array length to a value that is unknown at compile time. Yes, i know that it seems obvious that it should be known to the compiler, but this is not the case here. The compiler cannot make any assumptions about the contents of non-constant variables. So go with:

const int row = 8;
const int col= 8;
int a[row][col];

UPD: some compilers will actually allow you to pull this off. IIRC, g++ has this feature. However, never use it because your code will become un-portable across compilers.

How can I discard remote changes and mark a file as "resolved"?

Make sure of the conflict origin: if it is the result of a git merge, see Brian Campbell's answer.

But if is the result of a git rebase, in order to discard remote (their) changes and use local changes, you would have to do a:

git checkout --theirs -- .

See "Why is the meaning of “ours” and “theirs” reversed"" to see how ours and theirs are swapped during a rebase (because the upstream branch is checked out).

How can I make sticky headers in RecyclerView? (Without external lib)

Yo,

This is how you do it if you want just one type of holder stick when it starts getting out of the screen (we are not caring about any sections). There is only one way without breaking the internal RecyclerView logic of recycling items and that is to inflate additional view on top of the recyclerView's header item and pass data into it. I'll let the code speak.

import android.graphics.Canvas
import android.graphics.Rect
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.annotation.LayoutRes
import androidx.recyclerview.widget.RecyclerView

class StickyHeaderItemDecoration(@LayoutRes private val headerId: Int, private val HEADER_TYPE: Int) : RecyclerView.ItemDecoration() {

private lateinit var stickyHeaderView: View
private lateinit var headerView: View

private var sticked = false

// executes on each bind and sets the stickyHeaderView
override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {
    super.getItemOffsets(outRect, view, parent, state)

    val position = parent.getChildAdapterPosition(view)

    val adapter = parent.adapter ?: return
    val viewType = adapter.getItemViewType(position)

    if (viewType == HEADER_TYPE) {
        headerView = view
    }
}

override fun onDrawOver(c: Canvas, parent: RecyclerView, state: RecyclerView.State) {
    super.onDrawOver(c, parent, state)
    if (::headerView.isInitialized) {

        if (headerView.y <= 0 && !sticked) {
            stickyHeaderView = createHeaderView(parent)
            fixLayoutSize(parent, stickyHeaderView)
            sticked = true
        }

        if (headerView.y > 0 && sticked) {
            sticked = false
        }

        if (sticked) {
            drawStickedHeader(c)
        }
    }
}

private fun createHeaderView(parent: RecyclerView) = LayoutInflater.from(parent.context).inflate(headerId, parent, false)

private fun drawStickedHeader(c: Canvas) {
    c.save()
    c.translate(0f, Math.max(0f, stickyHeaderView.top.toFloat() - stickyHeaderView.height.toFloat()))
    headerView.draw(c)
    c.restore()
}

private fun fixLayoutSize(parent: ViewGroup, view: View) {

    // Specs for parent (RecyclerView)
    val widthSpec = View.MeasureSpec.makeMeasureSpec(parent.width, View.MeasureSpec.EXACTLY)
    val heightSpec = View.MeasureSpec.makeMeasureSpec(parent.height, View.MeasureSpec.UNSPECIFIED)

    // Specs for children (headers)
    val childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, parent.paddingLeft + parent.paddingRight, view.getLayoutParams().width)
    val childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, parent.paddingTop + parent.paddingBottom, view.getLayoutParams().height)

    view.measure(childWidthSpec, childHeightSpec)

    view.layout(0, 0, view.measuredWidth, view.measuredHeight)
}

}

And then you just do this in your adapter:

override fun onAttachedToRecyclerView(recyclerView: RecyclerView) {
    super.onAttachedToRecyclerView(recyclerView)
    recyclerView.addItemDecoration(StickyHeaderItemDecoration(R.layout.item_time_filter, YOUR_STICKY_VIEW_HOLDER_TYPE))
}

Where YOUR_STICKY_VIEW_HOLDER_TYPE is viewType of your what is supposed to be sticky holder.

How to Import .bson file format on mongodb

You have to run this mongorestore command via cmd and not on Mongo Shell... Have a look at below command on...

Run this command on cmd (not on Mongo shell)

>path\to\mongorestore.exe -d dbname -c collection_name path\to\same\collection.bson

Here path\to\mongorestore.exe is path of mongorestore.exe inside bin folder of mongodb. dbname is name of databse. collection_name is name of collection.bson. path\to\same\collection.bson is the path up to that collection.

Now from mongo shell you can verify that database is created or not (If it does not exist, database with same name will be created with collection).

How to resolve "could not execute statement; SQL [n/a]; constraint [numbering];"?

In my case, I had a OneToOne relation which I was using with @Column by mistake. I changed it to @JoinColumn and added @OneToOne annotation and it fixed the exception.

How to exit a 'git status' list in a terminal?

My preferred combo is Gq, which prints all diffs and then exits.

You can type h to show the help commands for interacting with less, which prints this to console:

                   SUMMARY OF LESS COMMANDS

      Commands marked with * may be preceded by a number, N.
      Notes in parentheses indicate the behavior if N is given.

  h  H                 Display this help.
  q  :q  Q  :Q  ZZ     Exit.
 ---------------------------------------------------------------------------

                           MOVING

  e  ^E  j  ^N  CR  *  Forward  one line   (or N lines).
  y  ^Y  k  ^K  ^P  *  Backward one line   (or N lines).
  f  ^F  ^V  SPACE  *  Forward  one window (or N lines).
  b  ^B  ESC-v      *  Backward one window (or N lines).
  z                 *  Forward  one window (and set window to N).
  w                 *  Backward one window (and set window to N).
  ESC-SPACE         *  Forward  one window, but don't stop at end-of-file.
  d  ^D             *  Forward  one half-window (and set half-window to N).
  u  ^U             *  Backward one half-window (and set half-window to N).
  ESC-)  RightArrow *  Left  one half screen width (or N positions).
  ESC-(  LeftArrow  *  Right one half screen width (or N positions).
  F                    Forward forever; like "tail -f".
  r  ^R  ^L            Repaint screen.
  R                    Repaint screen, discarding buffered input.
        ---------------------------------------------------
        Default "window" is the screen height.
        Default "half-window" is half of the screen height.
 ---------------------------------------------------------------------------

                          SEARCHING

  /pattern          *  Search forward for (N-th) matching line.
  ?pattern          *  Search backward for (N-th) matching line.
  n                 *  Repeat previous search (for N-th occurrence).
  N                 *  Repeat previous search in reverse direction.
  ESC-n             *  Repeat previous search, spanning files.
  ESC-N             *  Repeat previous search, reverse dir. & spanning files.
  ESC-u                Undo (toggle) search highlighting.
        ---------------------------------------------------
        Search patterns may be modified by one or more of:
        ^N or !  Search for NON-matching lines.
        ^E or *  Search multiple files (pass thru END OF FILE).
        ^F or @  Start search at FIRST file (for /) or last file (for ?).
        ^K       Highlight matches, but don't move (KEEP position).
        ^R       Don't use REGULAR EXPRESSIONS.
 ---------------------------------------------------------------------------

                           JUMPING

  g  <  ESC-<       *  Go to first line in file (or line N).
  G  >  ESC->       *  Go to last line in file (or line N).
  p  %              *  Go to beginning of file (or N percent into file).
  t                 *  Go to the (N-th) next tag.
  T                 *  Go to the (N-th) previous tag.
  {  (  [           *  Find close bracket } ) ].
  }  )  ]           *  Find open bracket { ( [.
  ESC-^F <c1> <c2>  *  Find close bracket <c2>.
  ESC-^B <c1> <c2>  *  Find open bracket <c1> 
        ---------------------------------------------------

How to embed YouTube videos in PHP?

You can simply create a php input form for Varchar date,give it a varchar length of lets say 300. Then ask the users to copy and paste the Embed code.When you view the records, you will view the streamed video.

How can I convert uppercase letters to lowercase in Notepad++

I had to transfer texts from an Excel file to an xliff file. We had some texts that were originally in uppercase but those translators didn't use uppercase so I used notepad++ as intermediate to do the conversion.

Since I had the mouse in one hand (to mark in Excel and activate the different windows) I disliked the predefined shortcut (Ctrl+Shift+U) as "U" is too far away for my left hand. I first switched it to Ctrl+Shift+X which worked.

Then I realized, that you can create macros easily, so I recorded one doing:

  • mark all
  • paste from clipboard
  • convert to upppercase
  • copy to clipboard

That macro got assigned that very shortcut (Ctrl+Shift+X) and made my life easy :)

Move top 1000 lines from text file to a new file using Unix shell commands

This is a one-liner but uses four atomic commands:

head -1000 file.txt > newfile.txt; tail +1000 file.txt > file.txt.tmp; cp file.txt.tmp file.txt; rm file.txt.tmp

MySQL vs MySQLi when using PHP

There is a manual page dedicated to help choosing between mysql, mysqli and PDO at

The PHP team recommends mysqli or PDO_MySQL for new development:

It is recommended to use either the mysqli or PDO_MySQL extensions. It is not recommended to use the old mysql extension for new development. A detailed feature comparison matrix is provided below. The overall performance of all three extensions is considered to be about the same. Although the performance of the extension contributes only a fraction of the total run time of a PHP web request. Often, the impact is as low as 0.1%.

The page also has a feature matrix comparing the extension APIs. The main differences between mysqli and mysql API are as follows:

                               mysqli     mysql
Development Status             Active     Maintenance only
Lifecycle                      Active     Long Term Deprecation Announced*
Recommended                    Yes        No
OOP API                        Yes        No
Asynchronous Queries           Yes        No
Server-Side Prep. Statements   Yes        No
Stored Procedures              Yes        No
Multiple Statements            Yes        No
Transactions                   Yes        No
MySQL 5.1+ functionality       Yes        No

* http://news.php.net/php.internals/53799

There is an additional feature matrix comparing the libraries (new mysqlnd versus libmysql) at

and a very thorough blog article at

How to use switch statement inside a React component?

This is another approach.

render() {
   return {this[`renderStep${this.state.step}`]()}

renderStep0() { return 'step 0' }
renderStep1() { return 'step 1' }

How can I find the last element in a List<>?

Use the Count property. The last index will be Count - 1.

for (int cnt3 = 0 ; cnt3 < integerList.Count; cnt3++)

Unable to convert MySQL date/time value to System.DateTime

i added both Convert Zero Datetime=True & Allow Zero Datetime=True and it works fine

How does Trello access the user's clipboard?

I actually built a Chrome extension that does exactly this, and for all web pages. The source code is on GitHub.

I find three bugs with Trello's approach, which I know because I've faced them myself :)

The copy doesn't work in these scenarios:

  1. If you already have Ctrl pressed and then hover a link and hit C, the copy doesn't work.
  2. If your cursor is in some other text field in the page, the copy doesn't work.
  3. If your cursor is in the address bar, the copy doesn't work.

I solved #1 by always having a hidden span, rather than creating one when user hits Ctrl/Cmd.

I solved #2 by temporarily clearing the zero-length selection, saving the caret position, doing the copy and restoring the caret position.

I haven't found a fix for #3 yet :) (For information, check the open issue in my GitHub project).

Switch statement equivalent in Windows batch file

Hariprasad didupe suggested a solution provided by Batchography, but it could be improved a bit. Unlike with other cases getting into default case will set ERRORLEVEL to 1 and, if that is not desired, you should manually set ERRORLEVEL to 0:

goto :switch-case-N-%N% 2>nul || (
    rem Default case
    rem Manually set ERRORLEVEL to 0 
    type nul>nul
    echo Something else
)
...

The readability could be improved for the price of a call overhead:

call:Switch SwitchLabel %N% || (
:SwitchLabel-1
    echo One
    goto:EOF     
:SwitchLabel-2
    echo Two
    goto:EOF
:SwitchLabel-3
    echo Three
    goto:EOF
:SwitchLabel-
    echo Default case
)

:Switch
goto:%1-%2 2>nul || (
    type nul>nul
    goto:%1-
)
exit /b

Few things to note:

  1. As stated before, this has a call overhead;
  2. Default case is required. If no action is needed put rem inside to avoid parenthesis error;
  3. All cases except the default one are executed in the sub-context. If you want to exit parent context (usually script) you may use this;
  4. Default case is executed in a parent context, so it cannot be combined with other cases (as reaching goto:EOF will exit parent context). This could be circumvented by replacing goto:%1- in subroutine with call:%1- for the price of additional call overhead;
  5. Subroutine takes label prefix (sans hyphen) and control variable. Without label prefix switch will look for labels with :- prefix (which are valid) and not passing a control variable will lead to default case.

How do I return JSON without using a template in Django?

I think the issue has gotten confused regarding what you want. I imagine you're not actually trying to put the HTML in the JSON response, but rather want to alternatively return either HTML or JSON.

First, you need to understand the core difference between the two. HTML is a presentational format. It deals more with how to display data than the data itself. JSON is the opposite. It's pure data -- basically a JavaScript representation of some Python (in this case) dataset you have. It serves as merely an interchange layer, allowing you to move data from one area of your app (the view) to another area of your app (your JavaScript) which normally don't have access to each other.

With that in mind, you don't "render" JSON, and there's no templates involved. You merely convert whatever data is in play (most likely pretty much what you're passing as the context to your template) to JSON. Which can be done via either Django's JSON library (simplejson), if it's freeform data, or its serialization framework, if it's a queryset.

simplejson

from django.utils import simplejson

some_data_to_dump = {
   'some_var_1': 'foo',
   'some_var_2': 'bar',
}

data = simplejson.dumps(some_data_to_dump)

Serialization

from django.core import serializers

foos = Foo.objects.all()

data = serializers.serialize('json', foos)

Either way, you then pass that data into the response:

return HttpResponse(data, content_type='application/json')

[Edit] In Django 1.6 and earlier, the code to return response was

return HttpResponse(data, mimetype='application/json')

[EDIT]: simplejson was remove from django, you can use:

import json

json.dumps({"foo": "bar"})

Or you can use the django.core.serializers as described above.

Display only date and no time

This works if you want to display in a TextBox:

@Html.TextBoxFor(m => m.Employee.DOB, "{0:dd-MM-yyyy}")

What does "Error: object '<myvariable>' not found" mean?

Let's discuss why an "object not found" error can be thrown in R in addition to explaining what it means. What it means (to many) is obvious: the variable in question, at least according to the R interpreter, has not yet been defined, but if you see your object in your code there can be multiple reasons for why this is happening:

  1. check syntax of your declarations. If you mis-typed even one letter or used upper case instead of lower case in a later calling statement, then it won't match your original declaration and this error will occur.

  2. Are you getting this error in a notebook or markdown document? You may simply need to re-run an earlier cell that has your declarations before running the current cell where you are calling the variable.

  3. Are you trying to knit your R document and the variable works find when you run the cells but not when you knit the cells? If so - then you want to examine the snippet I am providing below for a possible side effect that triggers this error:

    {r sourceDataProb1, echo=F, eval=F} # some code here

The above snippet is from the beginning of an R markdown cell. If eval and echo are both set to False this can trigger an error when you try to knit the document. To clarify. I had a use case where I had left these flags as False because I thought i did not want my code echoed or its results to show in the markdown HTML I was generating. But since the variable was then used in later cells, this caused an error during knitting. Simple trial and error with T/F TRUE/FALSE flags can establish if this is the source of your error when it occurs in knitting an R markdown document from RStudio.

Lastly: did you remove the variable or clear it from memory after declaring it?

  • rm() removes the variable
  • hitting the broom icon in the evironment window of RStudio clearls everything in the current working environment
  • ls() can help you see what is active right now to look for a missing declaration.
  • exists("x") - as mentioned by another poster, can help you test a specific value in an environment with a very lengthy list of active variables

Wait until an HTML5 video loads

You don't really need jQuery for this as there is a Media API that provides you with all you need.

var video = document.getElementById('myVideo');
video.src = 'my_video_' + value + '.ogg';
video.load();

The Media API also contains a load() method which: "Causes the element to reset and start selecting and loading a new media resource from scratch."

(Ogg isn't the best format to use, as it's only supported by a limited number of browsers. I'd suggest using WebM and MP4 to cover all major browsers - you can use the canPlayType() function to decide on which one to play).

You can then wait for either the loadedmetadata or loadeddata (depending on what you want) events to fire:

video.addEventListener('loadeddata', function() {
   // Video is loaded and can be played
}, false);

How to get text from each cell of an HTML table?

Another C# example. I just made an extension method for it.

public static string GetCellFromTable(this IWebElement table, int rowIndex, int columnIndex)
    {
        return table.FindElements(By.XPath("./tbody/tr"))[rowIndex].FindElements(By.XPath("./td"))[columnIndex].Text;
    }

Git pull command from different user

This command will help to pull from the repository as the different user:

git pull https://[email protected]/projectfolder/projectname.git master

It is a workaround, when you are using same machine that someone else used before you, and had saved credentials

Reading a cell value in Excel vba and write in another Cell

surely you can do this with worksheet formulas, avoiding VBA entirely:

so for this value in say, column AV S:1 P:0 K:1 Q:1

you put this formula in column BC:

=MID(AV:AV,FIND("S",AV:AV)+2,1)

then these formulas in columns BD, BE...

=MID(AV:AV,FIND("P",AV:AV)+2,1)
=MID(AV:AV,FIND("K",AV:AV)+2,1)
=MID(AV:AV,FIND("Q",AV:AV)+2,1)

so these formulas look for the values S:1, P:1 etc in column AV. If the FIND function returns an error, then 0 is returned by the formula, else 1 (like an IF, THEN, ELSE

Then you would just copy down the formulas for all the rows in column AV.

HTH Philip

How to find the difference in days between two dates?

Assume we rsync Oracle DB backups to a tertiary disk manually. Then we want to delete old backups on that disk. So here is a small bash script:

#!/bin/sh

for backup_dir in {'/backup/cmsprd/local/backupset','/backup/cmsprd/local/autobackup','/backup/cfprd/backupset','/backup/cfprd/autobackup'}
do

    for f in `find $backup_dir -type d -regex '.*_.*_.*' -printf "%f\n"`
    do

        f2=`echo $f | sed -e 's/_//g'`
        days=$(((`date "+%s"` - `date -d "${f2}" "+%s"`)/86400))

        if [ $days -gt 30 ]; then
            rm -rf $backup_dir/$f
        fi

    done

done

Modify the dirs and retention period ("30 days") to suit your needs.

Custom circle button

Unfortunately using an XML drawable and overriding the background means you have to explicitly set the colour instead of being able to use the app style colours.

Rather than hardcode the button colours for every behaviour I opted to hardcode the corner radius, which feels marginally less hacky and retains all the default button behaviour (changing colour when it's pressed and other visual effects) and uses the app style colours by default:

  1. Set android:layout_height and android:layout_width to the same value

  2. Set app:cornerRadius to half of the height/width

    (It actually appears that anything greater than or equal to half of the height/width works, so to avoid having to change the radius every time you update the height/width, you could instead set it to a very high value such as 1000dp, the risk being it could break if this behaviour ever changes.)

  3. Set android:insetBottom and android:insetTop to 0dp to get a perfect circle

For example:

<Button
    android:insetBottom="0dp"
    android:insetTop="0dp"
    android:layout_height="150dp"
    android:layout_width="150dp"
    app:cornerRadius="75dp"
    />

How to download and save a file from Internet using Java?

It's an old question but here is a concise, readable, JDK-only solution with properly closed resources:

static long download(String sourceUrl, String targetFileName) throws Exception {
    try (InputStream in = URI.create(sourceUrl).toURL().openStream()) {
        return Files.copy(in, Paths.get(targetFileName));
    }
}

Two lines of code and no dependencies.

Here's a complete file downloader example program with output, error checking, and command line argument checks:

package so.downloader;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URI;
import java.nio.file.Files;
import java.nio.file.Paths;

public class Application {
    public static void main(String[] args) throws MalformedURLException, IOException {
        if (2 != args.length) {
            System.out.println(String.format("USAGE: java -jar so-downloader.jar <source-URL> <target-filename>"));
            System.exit(1);
        }

        String sourceUrl = args[0];
        String targetFilename = args[1];

        long bytesDownloaded = download(sourceUrl, targetFilename);

        System.out.println(String.format("Downloaded %d bytes from %s to %s.", bytesDownloaded, sourceUrl, targetFilename));
    }

    static long download(String sourceUrl, String targetFileName) throws MalformedURLException, IOException {
        try (InputStream in = URI.create(sourceUrl).toURL().openStream()) {
            return Files.copy(in, Paths.get(targetFileName));
        }
    }

}

As noted in the so-downloader repository README:

To run file download program:

java -jar so-downloader.jar <source-URL> <target-filename>

for example:

java -jar so-downloader.jar https://github.com/JanStureNielsen/so-downloader/archive/main.zip so-downloader-source.zip

Hidden Columns in jqGrid

You can use the following code to hide a table column..

JQuery("tableName").hideCol("colName");

And you can use the following code to show it again.

JQuery("tableName").showCol("colName");

For your question, you can call the hideCol() code on the document.ready(), and you can bind the showCol() code on the dialog's edit/click event.

reStructuredText tool support

Salvaging (and extending) the list from an old version of the Wikipedia page:

Documentation

Implementations

Although the reference implementation of reStructuredText is written in Python, there are reStructuredText parsers in other languages too.

Python - Docutils

The main distribution of reStructuredText is the Python Docutils package. It contains several conversion tools:

  • rst2html - from reStructuredText to HTML
  • rst2xml - from reStructuredText to XML
  • rst2latex - from reStructuredText to LaTeX
  • rst2odt - from reStructuredText to ODF Text (word processor) document.
  • rst2s5 - from reStructuredText to S5, a Simple Standards-based Slide Show System
  • rst2man - from reStructuredText to Man page

Haskell - Pandoc

Pandoc is a Haskell library for converting from one markup format to another, and a command-line tool that uses this library. It can read Markdown and (subsets of) reStructuredText, HTML, and LaTeX, and it can write Markdown, reStructuredText, HTML, LaTeX, ConTeXt, PDF, RTF, DocBook XML, OpenDocument XML, ODT, GNU Texinfo, MediaWiki markup, groff man pages, and S5 HTML slide shows.

There is an Pandoc online tool (POT) to try this library. Unfortunately, compared to the reStructuredText online renderer (ROR),

  • POT truncates input rather more shortly. The POT user must render input in chunks that could be rendered whole by the ROR.
  • POT output lacks the helpful error messages displayed by the ROR (and generated by docutils)

Java - JRst

JRst is a Java reStructuredText parser. It can currently output HTML, XHTML, DocBook xdoc and PDF, BUT seems to have serious problems: neither PDF or (X)HTML generation works using the current full download, result pages in (X)HTML are empty and PDF generation fails on IO problems with XSL files (not bundled??). Note that the original JRst has been removed from the website; a fork is found on GitHub.

Scala - Laika

Laika is a new library for transforming markup languages to other output formats. Currently it supports input from Markdown and reStructuredText and produce HTML output. The library is written in Scala but should be also usable from Java.

Perl

PHP

C#/.NET

Nim/C

The Nim compiler features the commands rst2htmland rst2tex which transform reStructuredText files to HTML and TeX files. The standard library provides the following modules (used by the compiler) to handle reStructuredText files programmatically:

  • rst - implements a reStructuredText parser
  • rstast - implements an AST for the reStructuredText parser
  • rstgen - implements a generator of HTML/Latex from reStructuredText

Other 3rd party converters

Most (but not all) of these tools are based on Docutils (see above) and provide conversion to or from formats that might not be supported by the main distribution.

From reStructuredText

  • restview - This pip-installable python package requires docutils, which does the actual rendering. restview's major ease-of-use feature is that, when you save changes to your document(s), it automagically re-renders and re-displays them. restview
    1. starts a small web server
    2. calls docutils to render your document(s) to HTML
    3. calls your device's browser to display the output HTML.
  • rst2pdf - from reStructuredText to PDF
  • rst2odp - from reStructuredText to ODF Presentation
  • rst2beamer - from reStructuredText to LaTeX beamer Presentation class
  • Wikir - from reStructuredText to a Google (and possibly other) Wiki formats
  • rst2qhc - Convert a collection of reStructuredText files into a Qt (toolkit) Help file and (optional) a Qt Help Project file

To reStructuredText

  • xml2rst is an XSLT script to convert Docutils internal XML representation (back) to reStructuredText
  • Pandoc (see above) can also convert from Markdown, HTML and LaTeX to reStructuredText
  • db2rst is a simple and limited DocBook to reStructuredText translator
  • pod2rst - convert .pod files to reStructuredText files

Extensions

Some projects use reStructuredText as a baseline to build on, or provide extra functionality extending the utility of the reStructuredText tools.

Sphinx

The Sphinx documentation generator translates a set of reStructuredText source files into various output formats, automatically producing cross-references, indices etc.

rest2web

rest2web is a simple tool that lets you build your website from a single template (or as many as you want), and keep the contents in reStructuredText.

Pygments

Pygments is a generic syntax highlighter for general use in all kinds of software such as forum systems, Wikis or other applications that need to prettify source code. See Using Pygments in reStructuredText documents.

Free Editors

While any plain text editor is suitable to write reStructuredText documents, some editors have better support than others.

Emacs

The Emacs support via rst-mode comes as part of the Docutils package under /docutils/tools/editors/emacs/rst.el

Vim

The vim-common package for that comes with most GNU/Linux distributions has reStructuredText syntax highlight and indentation support of reStructuredText out of the box:

Jed

There is a rst mode for the Jed programmers editor.

gedit

gedit, the official text editor of the GNOME desktop environment. There is a gedit reStructuredText plugin.

Geany

Geany, a small and lightweight Integrated Development Environment include support for reStructuredText from version 0.12 (October 10, 2007).

Leo

Leo, an outlining editor for programmers, supports reStructuredText via rst-plugin or via "@auto-rst" nodes (it's not well-documented, but @auto-rst nodes allow editing rst files directly, parsing the structure into the Leo outline).

It also provides a way to preview the resulting HTML, in a "viewrendered" pane.

FTE

The FTE Folding Text Editor - a free (licensed under the GNU GPL) text editor for developers. FTE has a mode for reStructuredText support. It provides color highlighting of basic RSTX elements and special menu that provide easy way to insert most popular RSTX elements to a document.

PyK

PyK is a successor of PyEdit and reStInPeace, written in Python with the help of the Qt4 toolkit.

Eclipse

The Eclipse IDE with the ReST Editor plug-in provides support for editing reStructuredText files.

NoTex

NoTex is a browser based (general purpose) text editor, with integrated project management and syntax highlighting. Plus it enables to write books, reports, articles etc. using rST and convert them to LaTex, PDF or HTML. The PDF files are of high publication quality and are produced via Sphinx with the Texlive LaTex suite.

Notepad++

Notepad++ is a general purpose text editor for Windows. It has syntax highlighting for many languages built-in and support for reStructuredText via a user defined language for reStructuredText.

Visual Studio Code

Visual Studio Code is a general purpose text editor for Windows/macOS/Linux. It has syntax highlighting for many languages built-in and supports reStructuredText via an extension from LeXtudio.

Dedicated reStructuredText Editors

Proprietary editors

Sublime Text

Sublime Text is a completely customizable and extensible source code editor available for Windows, OS X, and Linux. Registration is required for long-term use, but all functions are available in the unregistered version, with occasional reminders to purchase a license. Versions 2 and 3 (currently in beta) support reStructuredText syntax highlighting by default, and several plugins are available through the package manager Package Control to provide snippets and code completion, additional syntax highlighting, conversion to/from RST and other formats, and HTML preview in the browser.

BBEdit / TextWrangler

BBEdit (and its free variant TextWrangler) for Mac can syntax-highlight reStructuredText using this codeless language module.

TextMate

TextMate, a proprietary general-purpose GUI text editor for Mac OS X, has a bundle for reStructuredText.

Intype

Intype is a proprietary text editor for Windows, that support reStructuredText out of the box.

E Text Editor

E is a proprietary Text Editor licensed under the "Open Company License". It supports TextMate's bundles, so it should support reStructuredText the same way TextMate does.

PyCharm

PyCharm (and other IntelliJ platform IDEs?) has ReST/Sphinx support (syntax highlighting, autocomplete and preview).instant preview)

Wiki

here are some Wiki programs that support the reStructuredText markup as the native markup syntax, or as an add-on:

MediaWiki

MediaWiki reStructuredText extension allows for reStructuredText markup in MediaWiki surrounded by <rst> and </rst>.

MoinMoin

MoinMoin is an advanced, easy to use and extensible WikiEngine with a large community of users. Said in a few words, it is about collaboration on easily editable web pages.

There is a reStructuredText Parser for MoinMoin.

Trac

Trac is an enhanced wiki and issue tracking system for software development projects. There is a reStructuredText Support in Trac.

This Wiki

This Wiki is a Webware for Python Wiki written by Ian Bicking. This wiki uses ReStructuredText for its markup.

rstiki

rstiki is a minimalist single-file personal wiki using reStructuredText syntax (via docutils) inspired by pwyky. It does not support authorship indication, versioning, hierarchy, chrome/framing/templating or styling. It leverages docutils/reStructuredText as the wiki syntax. As such, it's under 200 lines of code, and in a single file. You put it in a directory and it runs.

ikiwiki

Ikiwiki is a wiki compiler. It converts wiki pages into HTML pages suitable for publishing on a website. Ikiwiki stores pages and history in a revision control system such as Subversion or Git. There are many other features, including support for blogging, as well as a large array of plugins. It's reStructuredText plugin, however is somewhat limited and is not recommended as its' main markup language at this time.

Web Services

Sandbox

An Online reStructuredText editor can be used to play with the markup and see the results immediately.

Blogging frameworks

WordPress

WordPreSt reStructuredText plugin for WordPress. (PHP)

Zine

reStructuredText parser plugin for Zine (will become obsolete in version 0.2 when Zine is scheduled to get a native reStructuredText support). Zine is discontinued. (Python)

pelican

Pelican is a static blog generator that supports writing articles in ReST. (Python)

hyde

Hyde is a static website generator that supports ReST. (Python)

Acrylamid

Acrylamid is a static blog generator that supports writing articles in ReST. (Python)

Nikola

Nikola is a Static Site and Blog Generator that supports ReST. (Python)

ipsum genera

Ipsum genera is a static blog generator written in Nim.

Yozuch

Yozuch is a static blog generator written in Python.

More

TypeError: 'dict_keys' object does not support indexing

In Python 2 dict.keys() return a list, whereas in Python 3 it returns a generator.

You could only iterate over it's values else you may have to explicitly convert it to a list i.e. pass it to a list function.

Creating a list of pairs in java

Sounds like you need to create your own pair class (see discussion here). Then make a List of that pair class you created

Top 5 time-consuming SQL queries in Oracle

It depends which version of oracle you have, for 9i and below Statspack is what you are after, 10g and above, you want awr , both these tools will give you the top sql's and lots of other stuff.

How do I correctly clone a JavaScript object?

The problem with copying an object that, eventually, may point at itself, can be solved with a simple check. Add this check, every time there is a copy action. It may be slow, but it should work.

I use a toType() function to return the object type, explicitly. I also have my own copyObj() function, which is rather similar in logic, which answers all three Object(), Array(), and Date() cases.

I run it in NodeJS.

NOT TESTED, YET.

// Returns true, if one of the parent's children is the target.
// This is useful, for avoiding copyObj() through an infinite loop!
function isChild(target, parent) {
  if (toType(parent) == '[object Object]') {
    for (var name in parent) {
      var curProperty = parent[name];

      // Direct child.
      if (curProperty = target) return true;

      // Check if target is a child of this property, and so on, recursively.
      if (toType(curProperty) == '[object Object]' || toType(curProperty) == '[object Array]') {
        if (isChild(target, curProperty)) return true;
      }
    }
  } else if (toType(parent) == '[object Array]') {
    for (var i=0; i < parent.length; i++) {
      var curItem = parent[i];

      // Direct child.
      if (curItem = target) return true;

      // Check if target is a child of this property, and so on, recursively.
      if (toType(curItem) == '[object Object]' || toType(curItem) == '[object Array]') {
        if (isChild(target, curItem)) return true;
      }
    }
  }

  return false;     // Not the target.
}

'float' vs. 'double' precision

Floating point numbers in C use IEEE 754 encoding.

This type of encoding uses a sign, a significand, and an exponent.

Because of this encoding, many numbers will have small changes to allow them to be stored.

Also, the number of significant digits can change slightly since it is a binary representation, not a decimal one.

Single precision (float) gives you 23 bits of significand, 8 bits of exponent, and 1 sign bit.

Double precision (double) gives you 52 bits of significand, 11 bits of exponent, and 1 sign bit.

Looping each row in datagridview

You could loop through DataGridView using Rows property, like:

foreach (DataGridViewRow row in datagridviews.Rows)
{
   currQty += row.Cells["qty"].Value;
   //More code here
}

Java int to String - Integer.toString(i) vs new Integer(i).toString()

I also highly recommend using

int integer = 42;
String string = integer + "";

Simple and effective.

How to select ALL children (in any level) from a parent in jQuery?

I think you could do:

$('#google_translate_element').find('*').each(function(){
    $(this).unbind('click');
});

but it would cause a lot of overhead

What difference does .AsNoTracking() make?

Disabling tracking will also cause your result sets to be streamed into memory. This is more efficient when you're working with large sets of data and don't need the entire set of data all at once.

References:

Difference between numpy.array shape (R, 1) and (R,)

The difference between (R,) and (1,R) is literally the number of indices that you need to use. ones((1,R)) is a 2-D array that happens to have only one row. ones(R) is a vector. Generally if it doesn't make sense for the variable to have more than one row/column, you should be using a vector, not a matrix with a singleton dimension.

For your specific case, there are a couple of options:

1) Just make the second argument a vector. The following works fine:

    np.dot(M[:,0], np.ones(R))

2) If you want matlab like matrix operations, use the class matrix instead of ndarray. All matricies are forced into being 2-D arrays, and operator * does matrix multiplication instead of element-wise (so you don't need dot). In my experience, this is more trouble that it is worth, but it may be nice if you are used to matlab.

BigDecimal setScale and round

One important point that is alluded to but not directly addressed is the difference between "precision" and "scale" and how they are used in the two statements. "precision" is the total number of significant digits in a number. "scale" is the number of digits to the right of the decimal point.

The MathContext constructor only accepts precision and RoundingMode as arguments, and therefore scale is never specified in the first statement.

setScale() obviously accepts scale as an argument, as well as RoundingMode, however precision is never specified in the second statement.

If you move the decimal point one place to the right, the difference will become clear:

// 1.
new BigDecimal("35.3456").round(new MathContext(4, RoundingMode.HALF_UP));
//result = 35.35
// 2.
new BigDecimal("35.3456").setScale(4, RoundingMode.HALF_UP);
// result = 35.3456

What size do you use for varchar(MAX) in your parameter declaration?

For those of us who did not see -1 by Michal Chaniewski, the complete line of code:

cmd.Parameters.Add("@blah",SqlDbType.VarChar,-1).Value = "some large text";

SQL Server 2008: TOP 10 and distinct together

Few ideas:

  1. You have quite a few fields in your select statement. Any value being different from another will make that row distinct.
  2. TOP clauses are usually paired with WHERE clauses. Otherwise TOP doesn't mean much. Top of what? The way you specify "top of what" is to sort by using WHERE
  3. It's entirely possible to get the same results even though you use TOP and DISTINCT and WHERE. Check to make sure that the data you're querying is indeed capable of being filtered and ordered in the manner you expect.

Try something like this:

SELECT DISTINCT TOP 10 p.id, pl.nm -- , pl.val, pl.txt_val
FROM dm.labs pl
JOIN mas_data.patients p    
on pl.id = p.id
where pl.nm like '%LDL%'
and val is not null
ORDER BY pl.nm

Note that i commented out some of the SELECT to limit your result set and DISTINCT logic.

When to use the !important property in CSS

This is the real life scenario

Imagine this scenario

  1. You have a global CSS file that sets visual aspects of your site globally.
  2. You (or others) use inline styles on elements themselves which is usually very bad practice.

In this case you could set certain styles in your global CSS file as important, thus overriding inline styles set directly on elements.

Actual real world example?

This kind of scenario usually happens when you don't have total control over your HTML. Think of solutions in SharePoint for instance. You'd like your part to be globally defined (styled), but some inline styles you can't control are present. !important makes such situations easier to deal with.

Other real life scenarios would also include some badly written jQuery plugins that also use inline styles...

I suppose you got the idea by now and can come up with some others as well.

When do you decide to use !important?

I suggest you don't use !important unless you can't do it any other way. Whenever it's possible to avoid it, avoid it. Using lots of !important styles will make maintenance a bit harder, because you break the natural cascading in your stylesheets.

SQL Query - SUM(CASE WHEN x THEN 1 ELSE 0) for multiple columns

I think you should make a subquery to do grouping. In this case inner subquery returns few rows and you don't need a CASE statement. So I think this is going to be faster:

select Detail.ReceiptDate AS 'DATE',
       SUM(TotalMailed),
       SUM(TotalReturnMail),
       SUM(TraceReturnedMail)

from
(

select SentDate AS 'ReceiptDate', 
       count('TotalMailed') AS TotalMailed, 
       0 as TotalReturnMail, 
       0 as TraceReturnedMail
from MailDataExtract
where sentdate is not null
GROUP BY SentDate

UNION ALL
select MDE.ReturnMailDate AS 'ReceiptDate', 
       0 AS TotalMailed, 
       count(TotalReturnMail) as TotalReturnMail, 
       0 as TraceReturnedMail
from MailDataExtract MDE
where MDE.ReturnMailDate is not null
GROUP BY  MDE.ReturnMailDate

UNION ALL

select MDE.ReturnMailDate AS 'ReceiptDate', 
       0 AS TotalMailed, 
       0 as TotalReturnMail, 
       count(TraceReturnedMail) as TraceReturnedMail

from MailDataExtract MDE
    inner join DTSharedData.dbo.ScanData SD 
        ON SD.ScanDataID = MDE.ReturnScanDataID
   where MDE.ReturnMailDate is not null AND SD.ReturnMailTypeID = 1
GROUP BY MDE.ReturnMailDate

) as Detail
GROUP BY Detail.ReceiptDate
ORDER BY 1

Regex match one of two words

There are different regex engines but I think most of them will work with this:

apple|banana

Reverse a string in Python

The existing answers are only correct if Unicode Modifiers / grapheme clusters are ignored. I'll deal with that later, but first have a look at the speed of some reversal algorithms:

enter image description here

list_comprehension  : min:   0.6µs, mean:   0.6µs, max:    2.2µs
reverse_func        : min:   1.9µs, mean:   2.0µs, max:    7.9µs
reverse_reduce      : min:   5.7µs, mean:   5.9µs, max:   10.2µs
reverse_loop        : min:   3.0µs, mean:   3.1µs, max:    6.8µs

enter image description here

list_comprehension  : min:   4.2µs, mean:   4.5µs, max:   31.7µs
reverse_func        : min:  75.4µs, mean:  76.6µs, max:  109.5µs
reverse_reduce      : min: 749.2µs, mean: 882.4µs, max: 2310.4µs
reverse_loop        : min: 469.7µs, mean: 577.2µs, max: 1227.6µs

You can see that the time for the list comprehension (reversed = string[::-1]) is in all cases by far the lowest (even after fixing my typo).

String Reversal

If you really want to reverse a string in the common sense, it is WAY more complicated. For example, take the following string (brown finger pointing left, yellow finger pointing up). Those are two graphemes, but 3 unicode code points. The additional one is a skin modifier.

example = ""

But if you reverse it with any of the given methods, you get brown finger pointing up, yellow finger pointing left. The reason for this is that the "brown" color modifier is still in the middle and gets applied to whatever is before it. So we have

  • U: finger pointing up
  • M: brown modifier
  • L: finger pointing left

and

original: LMU
reversed: UML (above solutions)
reversed: ULM (correct reversal)

Unicode Grapheme Clusters are a bit more complicated than just modifier code points. Luckily, there is a library for handling graphemes:

>>> import grapheme
>>> g = grapheme.graphemes("")
>>> list(g)
['', '']

and hence the correct answer would be

def reverse_graphemes(string):
    g = list(grapheme.graphemes(string))
    return ''.join(g[::-1])

which also is by far the slowest:

list_comprehension  : min:    0.5µs, mean:    0.5µs, max:    2.1µs
reverse_func        : min:   68.9µs, mean:   70.3µs, max:  111.4µs
reverse_reduce      : min:  742.7µs, mean:  810.1µs, max: 1821.9µs
reverse_loop        : min:  513.7µs, mean:  552.6µs, max: 1125.8µs
reverse_graphemes   : min: 3882.4µs, mean: 4130.9µs, max: 6416.2µs

The Code

#!/usr/bin/env python

import numpy as np
import random
import timeit
from functools import reduce
random.seed(0)


def main():
    longstring = ''.join(random.choices("ABCDEFGHIJKLM", k=2000))
    functions = [(list_comprehension, 'list_comprehension', longstring),
                 (reverse_func, 'reverse_func', longstring),
                 (reverse_reduce, 'reverse_reduce', longstring),
                 (reverse_loop, 'reverse_loop', longstring)
                 ]
    duration_list = {}
    for func, name, params in functions:
        durations = timeit.repeat(lambda: func(params), repeat=100, number=3)
        duration_list[name] = list(np.array(durations) * 1000)
        print('{func:<20}: '
              'min: {min:5.1f}µs, mean: {mean:5.1f}µs, max: {max:6.1f}µs'
              .format(func=name,
                      min=min(durations) * 10**6,
                      mean=np.mean(durations) * 10**6,
                      max=max(durations) * 10**6,
                      ))
        create_boxplot('Reversing a string of length {}'.format(len(longstring)),
                       duration_list)


def list_comprehension(string):
    return string[::-1]


def reverse_func(string):
    return ''.join(reversed(string))


def reverse_reduce(string):
    return reduce(lambda x, y: y + x, string)


def reverse_loop(string):
    reversed_str = ""
    for i in string:
        reversed_str = i + reversed_str
    return reversed_str


def create_boxplot(title, duration_list, showfliers=False):
    import seaborn as sns
    import matplotlib.pyplot as plt
    import operator
    plt.figure(num=None, figsize=(8, 4), dpi=300,
               facecolor='w', edgecolor='k')
    sns.set(style="whitegrid")
    sorted_keys, sorted_vals = zip(*sorted(duration_list.items(),
                                           key=operator.itemgetter(1)))
    flierprops = dict(markerfacecolor='0.75', markersize=1,
                      linestyle='none')
    ax = sns.boxplot(data=sorted_vals, width=.3, orient='h',
                     flierprops=flierprops,
                     showfliers=showfliers)
    ax.set(xlabel="Time in ms", ylabel="")
    plt.yticks(plt.yticks()[0], sorted_keys)
    ax.set_title(title)
    plt.tight_layout()
    plt.savefig("output-string.png")


if __name__ == '__main__':
    main()

How to open warning/information/error dialog in Swing?

Just complementing: It's kind of obvious, but you can use static imports to give you a hand, like this:

import static javax.swing.JOptionPane.*;

public class SimpleDialog(){
    public static void main(String argv[]) {
        showMessageDialog(null, "Message", "Title", ERROR_MESSAGE);
    }
}

Handling identity columns in an "Insert Into TABLE Values()" statement?

set identity_insert customer on
insert into Customer(id,Name,city,Salary) values(8,'bcd','Amritsar',1234)

where 'customer' is table name

How to open every file in a folder

import pyautogui
import keyboard
import time
import os
import pyperclip

os.chdir("target directory")

# get the current directory
cwd=os.getcwd()

files=[]

for i in os.walk(cwd):
    for j in i[2]:
        files.append(os.path.abspath(j))

os.startfile("C:\Program Files (x86)\Adobe\Acrobat 11.0\Acrobat\Acrobat.exe")
time.sleep(1)


for i in files:
    print(i)
    pyperclip.copy(i)
    keyboard.press('ctrl')
    keyboard.press_and_release('o')
    keyboard.release('ctrl')
    time.sleep(1)

    keyboard.press('ctrl')
    keyboard.press_and_release('v')
    keyboard.release('ctrl')
    time.sleep(1)
    keyboard.press_and_release('enter')
    keyboard.press('ctrl')
    keyboard.press_and_release('p')
    keyboard.release('ctrl')
    keyboard.press_and_release('enter')
    time.sleep(3)
    keyboard.press('ctrl')
    keyboard.press_and_release('w')
    keyboard.release('ctrl')
    pyperclip.copy('')

Removing page title and date when printing web page (with CSS?)

There's a facility to have a separate style sheet for print, using

 <link type="text/css" rel="stylesheet" media="print" href="print.css">

I don't know if it does what you want though.

Javascript : array.length returns undefined

Objects don't have a .length property.

A simple solution if you know you don't have to worry about hasOwnProperty checks, would be to do this:

Object.keys(data).length;

If you have to support IE 8 or lower, you'll have to use a loop, instead:

var length= 0;
for(var key in data) {
    if(data.hasOwnProperty(key)){
        length++;
    }
}

Using Postman to access OAuth 2.0 Google APIs

This is an old question, but it has no chosen answer, and I just solved this problem myself. Here's my solution:

  1. Make sure you are set up to work with your Google API in the first place. See Google's list of prerequisites. I was working with Google My Business, so I also went through it's Get Started process.

  2. In the OAuth 2.0 playground, Step 1 requires you to select which API you want to authenticate. Select or input as applicable for your case (in my case for Google My Business, I had to input https://www.googleapis.com/auth/plus.business.manage into the "Input your own scopes" input field). Note: this is the same as what's described in step 6 of the "Make a simple HTTP request" section of the Get Started guide.

  3. Assuming successful authentication, you should get an "Access token" returned in the "Step 1's result" step in the OAuth playground. Copy this token to your clipboard.

  4. Open Postman and open whichever collection you want as necessary.

  5. In Postman, make sure "GET" is selected as the request type, and click on the "Authorization" tab below the request type drop-down.

  6. In the Authorization "TYPE" dropdown menu, select "Bearer Token"

  7. Paste your previously copied "Access Token" which you copied from the OAuth playground into the "Token" field which displays in Postman.

  8. Almost there! To test if things work, put https://mybusiness.googleapis.com/v4/accounts/ into the main URL input bar in Postman and click the send button. You should get a JSON list of accounts back in the response that looks something like the following:

    
    {
        "accounts": [
            {
                "name": "accounts/REDACTED",
                "accountName": "REDACTED",
                "type": "PERSONAL",
                "state": {
                    "status": "UNVERIFIED"
                }
            },
            {
                "name": "accounts/REDACTED",
                "accountName": "REDACTED",
                "type": "LOCATION_GROUP",
                "role": "OWNER",
                "state": {
                    "status": "UNVERIFIED"
                },
                "permissionLevel": "OWNER_LEVEL"
            }
        ]
    }
    

What is limiting the # of simultaneous connections my ASP.NET application can make to a web service?

If it is not defined in the web service or application or server (apache or IIS) that is hosting the web service consumable then you could create infinite connections until failure

setup.py examples?

Here you will find the simplest possible example of using distutils and setup.py:

https://docs.python.org/2/distutils/introduction.html#distutils-simple-example

This assumes that all your code is in a single file and tells how to package a project containing a single module.

Render HTML string as real HTML in a React component

I use 'react-html-parser'

yarn add react-html-parser
import ReactHtmlParser from 'react-html-parser'; 

<div> { ReactHtmlParser (html_string) } </div>

Source on npmjs.com

Lifting up @okram's comment for more visibility:

from its github description: Converts HTML strings directly into React components avoiding the need to use dangerouslySetInnerHTML from npmjs.com A utility for converting HTML strings into React components. Avoids the use of dangerouslySetInnerHTML and converts standard HTML elements, attributes and inline styles into their React equivalents.

How to save and load numpy.array() data properly?

For a short answer you should use np.save and np.load. The advantages of these is that they are made by developers of the numpy library and they already work (plus are likely already optimized nicely) e.g.

import numpy as np
from pathlib import Path

path = Path('~/data/tmp/').expanduser()
path.mkdir(parents=True, exist_ok=True)

lb,ub = -1,1
num_samples = 5
x = np.random.uniform(low=lb,high=ub,size=(1,num_samples))
y = x**2 + x + 2

np.save(path/'x', x)
np.save(path/'y', y)

x_loaded = np.load(path/'x.npy')
y_load = np.load(path/'y.npy')

print(x is x_loaded) # False
print(x == x_loaded) # [[ True  True  True  True  True]]

Expanded answer:

In the end it really depends in your needs because you can also save it human readable format (see this Dump a NumPy array into a csv file) or even with other libraries if your files are extremely large (see this best way to preserve numpy arrays on disk for an expanded discussion).

However, (making an expansion since you use the word "properly" in your question) I still think using the numpy function out of the box (and most code!) most likely satisfy most user needs. The most important reason is that it already works. Trying to use something else for any other reason might take you on an unexpectedly LONG rabbit hole to figure out why it doesn't work and force it work.

Take for example trying to save it with pickle. I tried that just for fun and it took me at least 30 minutes to realize that pickle wouldn't save my stuff unless I opened & read the file in bytes mode with wb. Took time to google, try thing, understand the error message etc... Small detail but the fact that it already required me to open a file complicated things in unexpected ways. To add that it required me to re-read this (which btw is sort of confusing) Difference between modes a, a+, w, w+, and r+ in built-in open function?.

So if there is an interface that meets your needs use it unless you have a (very) good reason (e.g. compatibility with matlab or for some reason your really want to read the file and printing in python really doesn't meet your needs, which might be questionable). Furthermore, most likely if you need to optimize it you'll find out later down the line (rather than spend ages debugging useless stuff like opening a simple numpy file).

So use the interface/numpy provide. It might not be perfect it's most likely fine, especially for a library that's been around as long as numpy.

I already spent the saving and loading data with numpy in a bunch of way so have fun with it, hope it helps!

import numpy as np
import pickle
from pathlib import Path

path = Path('~/data/tmp/').expanduser()
path.mkdir(parents=True, exist_ok=True)

lb,ub = -1,1
num_samples = 5
x = np.random.uniform(low=lb,high=ub,size=(1,num_samples))
y = x**2 + x + 2

# using save (to npy), savez (to npz)
np.save(path/'x', x)
np.save(path/'y', y)
np.savez(path/'db', x=x, y=y)
with open(path/'db.pkl', 'wb') as db_file:
    pickle.dump(obj={'x':x, 'y':y}, file=db_file)

## using loading npy, npz files
x_loaded = np.load(path/'x.npy')
y_load = np.load(path/'y.npy')
db = np.load(path/'db.npz')
with open(path/'db.pkl', 'rb') as db_file:
    db_pkl = pickle.load(db_file)

print(x is x_loaded)
print(x == x_loaded)
print(x == db['x'])
print(x == db_pkl['x'])
print('done')

Some comments on what I learned:

  • np.save as expected, this already compresses it well (see https://stackoverflow.com/a/55750128/1601580), works out of the box without any file opening. Clean. Easy. Efficient. Use it.
  • np.savez uses a uncompressed format (see docs) Save several arrays into a single file in uncompressed .npz format. If you decide to use this (you were warned to go away from the standard solution so expect bugs!) you might discover that you need to use argument names to save it, unless you want to use the default names. So don't use this if the first already works (or any works use that!)
  • Pickle also allows for arbitrary code execution. Some people might not want to use this for security reasons.
  • human readable files are expensive to make etc. Probably not worth it.
  • there is something called hdf5 for large files. Cool! https://stackoverflow.com/a/9619713/1601580

Note this is not an exhaustive answer. But for other resources check this:

java.lang.IllegalArgumentException: No converter found for return value of type

I had the very same problem, and unfortunately it could not be solved by adding getter methods, or adding jackson dependencies.

I then looked at Official Spring Guide, and followed their example as given here - https://spring.io/guides/gs/actuator-service/ - where the example also shows the conversion of returned object to JSON format.

I then again made my own project, with the difference that this time I also added the dependencies and build plugins that's present in the pom.xml file of the Official Spring Guide example I mentioned above.

The modified dependencies and build part of XML file looks like this!

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

You can see the same in the mentioned link above.

And magically, atleast for me, it works. So, if you have already exhausted your other options, you might want to try this out, as was the case with me.

Just a side note, it didn't work for me when I added the dependencies in my previous project and did Maven install and update project stuff. So, I had to again make my project from scratch. I didn't bother much about it as mine is an example project, but you might want to look for that too!

PHP PDO returning single row

Did you try:

$DBH = new PDO( "connection string goes here" );
$row = $DBH->query( "select figure from table1" )->fetch();
echo $row["figure"];
$DBH = null;

Focus Input Box On Load

This is what works fine for me:

<form name="f" action="/search">
    <input name="q" onfocus="fff=1" />
</form>

fff will be a global variable which name is absolutely irrelevant and which aim will be to stop the generic onload event to force focus in that input.

<body onload="if(!this.fff)document.f.q.focus();">
    <!-- ... the rest of the page ... -->
</body>

From: http://webreflection.blogspot.com.br/2009/06/inputfocus-something-really-annoying.html

How to reset AUTO_INCREMENT in MySQL?

The auto increment counter for a table can be (re)set in two ways:

  1. By executing a query, like others already explained:

    ALTER TABLE <table_name> AUTO_INCREMENT=<table_id>;

  2. Using Workbench or other visual database design tool. I am gonna show in Workbench how it is done - but it shouldn't be much different in other tool as well. By right click over the desired table and choosing Alter table from the context menu. On the bottom you can see all the available options for altering a table. Choose Options and you will get this form: enter image description here

    Then just set the desired value in the field Auto increment as shown in the image. This will basically execute the query shown in the first option.

How does Tomcat locate the webapps directory?

It can be changed in the $CATALINA_BASE/conf/server.xml in the <Host />. See the Tomcat documentation, specifically the section in regards to the Host container:

Tomcat 6 Configuration

Tomcat 7 Configuration

The default is webapps relative to the $CATALINA_BASE. An absolute pathname can be used.

Hope that helps.

How to compare two maps by their values

To see if two maps have the same values, you can do the following:

  • Get their Collection<V> values() views
  • Wrap into List<V>
  • Collections.sort those lists
  • Test if the two lists are equals

Something like this works (though its type bounds can be improved on):

static <V extends Comparable<V>>
boolean valuesEquals(Map<?,V> map1, Map<?,V> map2) {
    List<V> values1 = new ArrayList<V>(map1.values());
    List<V> values2 = new ArrayList<V>(map2.values());
    Collections.sort(values1);
    Collections.sort(values2);
    return values1.equals(values2);
}

Test harness:

Map<String, String> map1 = new HashMap<String,String>();
map1.put("A", "B");
map1.put("C", "D");

Map<String, String> map2 = new HashMap<String,String>();
map2.put("A", "D");
map2.put("C", "B");

System.out.println(valuesEquals(map1, map2)); // prints "true"

This is O(N log N) due to Collections.sort.

See also:


To test if the keys are equals is easier, because they're Set<K>:

map1.keySet().equals(map2.keySet())

See also:

Conversion of a datetime2 data type to a datetime data type results out-of-range value

If we dont pass a date time to date time field the default date {1/1/0001 12:00:00 AM} will be passed.

But this date is not compatible with entity frame work so it will throw conversion of a datetime2 data type to a datetime data type resulted in an out-of-range value

Just default DateTime.now to the date field if you are not passing any date .

movie.DateAdded = System.DateTime.Now

Adb Devices can't find my phone

I have a ZTE Crescent phone (Orange San Francisco II).

When I connect the phone to the USB a disk shows up in OS X named 'ZTE_USB_Driver'.

Running adb devices displays no connected devices. But after I eject the 'ZTE_USB_Driver' disk from OS X, and run adb devices again the phone shows up as connected.

HttpClient 4.0.1 - how to release connection?

This seems to work great :

      if( response.getEntity() != null ) {
         response.getEntity().consumeContent();
      }//if

And don't forget to consume the entity even if you didn't open its content. For instance, you expect a HTTP_OK status from the response and don't get it, you still have to consume the entity !

Python: finding lowest integer

You have to start somewhere the correct code should be:

The code to return the minimum value

l = [ '0.0', '1','-1.2'] x = l[0] for i in l: if i < x: x = i print x

But again it's good to use directly integers instead of using quotations ''

This way!

l = [ 0.0, 1,-1.2] x = l[0] for i in l: if i < x: x = i print x

What is the regular expression to allow uppercase/lowercase (alphabetical characters), periods, spaces and dashes only?

The regex you're looking for is ^[A-Za-z.\s_-]+$

  • ^ asserts that the regular expression must match at the beginning of the subject
  • [] is a character class - any character that matches inside this expression is allowed
  • A-Z allows a range of uppercase characters
  • a-z allows a range of lowercase characters
  • . matches a period rather than a range of characters
  • \s matches whitespace (spaces and tabs)
  • _ matches an underscore
  • - matches a dash (hyphen); we have it as the last character in the character class so it doesn't get interpreted as being part of a character range. We could also escape it (\-) instead and put it anywhere in the character class, but that's less clear
  • + asserts that the preceding expression (in our case, the character class) must match one or more times
  • $ Finally, this asserts that we're now at the end of the subject

When you're testing regular expressions, you'll likely find a tool like regexpal helpful. This allows you to see your regular expression match (or fail to match) your sample data in real time as you write it.

How to calculate a mod b in Python?

I don't think you're fully grasping modulo. a % b and a mod b are just two different ways to express modulo. In this case, python uses %. No, 15 mod 4 is not 1, 15 % 4 == 15 mod 4 == 3.

Access to the path 'c:\inetpub\wwwroot\myapp\App_Data' is denied

I created copy of my inet folder, to make a duplicate of the site. It showed 'access denied .../App_Data/viewstate/1/6/6/0 ... '. On checking it showed that app_data folder is having IIS_IUSER addes but does not have modify or write acess checked. Just check those boxes and the instance begin to run.

What is the reason behind "non-static method cannot be referenced from a static context"?

A non-static method is dependent on the object. It is recognized by the program once the object is created.

Static methods can be called even before the creation of an object. Static methods are great for doing comparisons or operations that aren't dependent on the actual objects you plan to work with.

Ping a site in Python?

You may find Noah Gift's presentation Creating Agile Commandline Tools With Python. In it he combines subprocess, Queue and threading to develop solution that is capable of pinging hosts concurrently and speeding up the process. Below is a basic version before he adds command line parsing and some other features. The code to this version and others can be found here

#!/usr/bin/env python2.5
from threading import Thread
import subprocess
from Queue import Queue

num_threads = 4
queue = Queue()
ips = ["10.0.1.1", "10.0.1.3", "10.0.1.11", "10.0.1.51"]
#wraps system ping command
def pinger(i, q):
    """Pings subnet"""
    while True:
        ip = q.get()
        print "Thread %s: Pinging %s" % (i, ip)
        ret = subprocess.call("ping -c 1 %s" % ip,
            shell=True,
            stdout=open('/dev/null', 'w'),
            stderr=subprocess.STDOUT)
        if ret == 0:
            print "%s: is alive" % ip
        else:
            print "%s: did not respond" % ip
        q.task_done()
#Spawn thread pool
for i in range(num_threads):

    worker = Thread(target=pinger, args=(i, queue))
    worker.setDaemon(True)
    worker.start()
#Place work in queue
for ip in ips:
    queue.put(ip)
#Wait until worker threads are done to exit    
queue.join()

He is also author of: Python for Unix and Linux System Administration

http://ecx.images-amazon.com/images/I/515qmR%2B4sjL._SL500_AA240_.jpg

How do you wait for input on the same Console.WriteLine() line?

Use Console.Write instead, so there's no newline written:

Console.Write("What is your name? ");
var name = Console.ReadLine();

Spring Boot - Handle to Hibernate SessionFactory

Great work Andreas. I created a bean version so the SessionFactory could be autowired.

import javax.persistence.EntityManagerFactory;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;

....

@Autowired
private EntityManagerFactory entityManagerFactory;

@Bean
public SessionFactory getSessionFactory() {
    if (entityManagerFactory.unwrap(SessionFactory.class) == null) {
        throw new NullPointerException("factory is not a hibernate factory");
    }
    return entityManagerFactory.unwrap(SessionFactory.class);
}

How to keep :active css style after clicking an element

The :target-pseudo selector is made for these type of situations: http://reference.sitepoint.com/css/pseudoclass-target

It is supported by all modern browsers. To get some IE versions to understand it you can use something like Selectivizr

Here is a tab example with :target-pseudo selector.

How do I make the scrollbar on a div only visible when necessary?

try this:

<div style='overflow:auto; width:400px;height:400px;'>here is some text</div>

How to upper case every first letter of word in a string?

i dont know if there is a function but this would do the job in case there is no exsiting one:

String s = "here are a bunch of words";

final StringBuilder result = new StringBuilder(s.length());
String[] words = s.split("\\s");
for(int i=0,l=words.length;i<l;++i) {
  if(i>0) result.append(" ");      
  result.append(Character.toUpperCase(words[i].charAt(0)))
        .append(words[i].substring(1));

}

Two onClick actions one button

Give your button an id something like this:


<input id="mybutton" type="button" value="Dont show this again! " />

Then use jquery (to make this unobtrusive) and attach click action like so:


$(document).ready(function (){
    $('#mybutton').click(function (){
       fbLikeDump();
       WriteCookie();
    });
});

(this part should be in your .js file too)

I should have mentioned that you will need the jquery libraries on your page, so right before your closing body tag add these:


<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<script type="text/javascript" src="http://PATHTOYOURJSFILE"></script>

The reason to add just before body closing tag is for performance of perceived page loading times

length and length() in Java

Let me first highlight three different ways for similar purpose.

length -- arrays (int[], double[], String[]) -- to know the length of the arrays

length() -- String related Object (String, StringBuilder, etc) -- to know the length of the String

size() -- Collection Object (ArrayList, Set, etc) -- to know the size of the Collection

Now forget about length() consider just length and size().

length is not a method, so it completely makes sense that it will not work on objects. It only works on arrays.
size() its name describes it better and as it is a method, it will be used in the case of those objects who work with collection (collection frameworks) as I said up there.

Now come to length():
String is not a primitive array (so we can't use .length) and also not a Collection (so we cant use .size()) that's why we also need a different one which is length() (keep the differences and serve the purpose).

As answer to Why?
I find it useful, easy to remember and use and friendly.

How can I set the aspect ratio in matplotlib?

This answer is based on Yann's answer. It will set the aspect ratio for linear or log-log plots. I've used additional information from https://stackoverflow.com/a/16290035/2966723 to test if the axes are log-scale.

def forceAspect(ax,aspect=1):
    #aspect is width/height
    scale_str = ax.get_yaxis().get_scale()
    xmin,xmax = ax.get_xlim()
    ymin,ymax = ax.get_ylim()
    if scale_str=='linear':
        asp = abs((xmax-xmin)/(ymax-ymin))/aspect
    elif scale_str=='log':
        asp = abs((scipy.log(xmax)-scipy.log(xmin))/(scipy.log(ymax)-scipy.log(ymin)))/aspect
    ax.set_aspect(asp)

Obviously you can use any version of log you want, I've used scipy, but numpy or math should be fine.

How can I String.Format a TimeSpan object with a custom format in .NET?

If you want the duration format similar to youtube, given the number of seconds

int[] duration = { 0, 4, 40, 59, 60, 61, 400, 4000, 40000, 400000 };
foreach (int d in duration)
{
    Console.WriteLine("{0, 6} -> {1, 10}", d, d > 59 ? TimeSpan.FromSeconds(d).ToString().TrimStart("00:".ToCharArray()) : string.Format("0:{0:00}", d));
}

Output:

     0 ->       0:00
     4 ->       0:04
    40 ->       0:40
    59 ->       0:59
    60 ->       1:00
    61 ->       1:01
   400 ->       6:40
  4000 ->    1:06:40
 40000 ->   11:06:40
400000 -> 4.15:06:40

Nginx 403 error: directory index of [folder] is forbidden

location ~* \.php$ {
    ...
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;    
}

Change default

fastcgi_param  SCRIPT_FILENAME  /scripts$fastcgi_script_name;

to

fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;

solved my problem.

the easiest way to convert matrix to one row vector

You can use the function RESHAPE:

B = reshape(A.',1,[]);

! [rejected] master -> master (fetch first)

You can use the following command: First clone a fresh copy of your repo, using the --mirror flag:

$ git clone --mirror git://example.com/some-big-repo.git

Then follow the codes accordingly:

Adding an existing project to GitHub using the command line

Even if that doesn't work, you can simply code:

$ git push origin master --force 

or

$ git push origin master -f

How can I generate a 6 digit unique number?

<?php echo rand(100000,999999); ?>

you can generate random number

How to show row number in Access query like ROW_NUMBER in SQL

You can try this query:

Select A.*, (select count(*) from Table1 where A.ID>=ID) as RowNo
from Table1 as A
order by A.ID

MySQL - DATE_ADD month interval

BETWEEN ... AND

If expr is greater than or equal to min and expr is less than or equal to max, BETWEEN returns 1, otherwise it returns 0.

The important part here is EQUAL to max., which 1st of July is.

Most efficient way to convert an HTMLCollection to an Array

To convert array-like to array in efficient way we can make use of the jQuery makeArray :

makeArray: Convert an array-like object into a true JavaScript array.

Usage:

var domArray = jQuery.makeArray(htmlCollection);

A little extra:

If you do not want to keep reference to the array object (most of the time HTMLCollections are dynamically changes so its better to copy them into another array, This example pay close attention to performance:

var domDataLength = domData.length //Better performance, no need to calculate every iteration the domArray length
var resultArray = new Array(domDataLength) // Since we know the length its improves the performance to declare the result array from the beginning.

for (var i = 0 ; i < domDataLength ; i++) {
    resultArray[i] = domArray[i]; //Since we already declared the resultArray we can not make use of the more expensive push method.
}

What is array-like?

HTMLCollection is an "array-like" object, the array-like objects are similar to array's object but missing a lot of its functionally definition:

Array-like objects look like arrays. They have various numbered elements and a length property. But that’s where the similarity stops. Array-like objects do not have any of Array’s functions, and for-in loops don’t even work!

Sort a two dimensional array based on one column

Arrays.sort(yourarray, new Comparator() {
    public int compare(Object o1, Object o2) {
        String[] elt1 = (String[])o1;
        String[] elt2 = (String[])o2;
        return elt1[0].compareTo(elt2[0]);
    }
});

How to embed fonts in CSS?

Following lines are used to define a font in css

@font-face {
    font-family: 'EntezareZohoor2';
    src: url('fonts/EntezareZohoor2.eot'), url('fonts/EntezareZohoor2.ttf') format('truetype'), url('fonts/EntezareZohoor2.svg') format('svg');
    font-weight: normal;
    font-style: normal;
}

Following lines to define/use the font in css

#newfont{
    font-family:'EntezareZohoor2';
}

How do I find the version of Apache running without access to the command line?

The level of version information given out by an Apache server can be configured by the ServerTokens setting in its configuration.

I believe there is also a setting that controls whether the version appears in server error pages, although I can't remember what it is off the top of my head. If you don't have direct access to the server, and the server administrator is competent and doesn't want you to know the version they're running... I think you may be SOL.

RESTful web service - how to authenticate requests from other services?

Besides authentication, I suggest you think about the big picture. Consider make your backend RESTful service without any authentication; then put some very simple authentication required middle layer service between the end user and the backend service.

jQuery Ajax error handling, show custom exception messages

First we need to set <serviceDebug includeExceptionDetailInFaults="True" /> in web.config:

<serviceBehaviors> 
 <behavior name=""> 
  <serviceMetadata httpGetEnabled="true" /> 
    **<serviceDebug includeExceptionDetailInFaults="true" />** 
 </behavior> 
</serviceBehaviors>

In addition to that at jquery level in error part you need to parse error response that contains exception like:

.error(function (response, q, t) { 
  var r = jQuery.parseJSON(response.responseText); 
}); 

Then using r.Message you can actully show exception text.

Check complete code: http://www.codegateway.com/2012/04/jquery-ajax-handle-exception-thrown-by.html

upstream sent too big header while reading response header from upstream

upstream sent too big header while reading response header from upstream is nginx's generic way of saying "I don't like what I'm seeing"

  1. Your upstream server thread crashed
  2. The upstream server sent an invalid header back
  3. The Notice/Warnings sent back from STDERR overflowed their buffer and both it and STDOUT were closed

3: Look at the error logs above the message, is it streaming with logged lines preceding the message? PHP message: PHP Notice: Undefined index: Example snippet from a loop my log file:

2015/11/23 10:30:02 [error] 32451#0: *580927 FastCGI sent in stderr: "PHP message: PHP Notice:  Undefined index: Firstname in /srv/www/classes/data_convert.php on line 1090
PHP message: PHP Notice:  Undefined index: Lastname in /srv/www/classes/data_convert.php on line 1090
... // 20 lines of same
PHP message: PHP Notice:  Undefined index: Firstname in /srv/www/classes/data_convert.php on line 1090
PHP message: PHP Notice:  Undefined index: Lastname in /srv/www/classes/data_convert.php on line 1090
PHP message: PHP Notice:  Undef
2015/11/23 10:30:02 [error] 32451#0: *580927 FastCGI sent in stderr: "ta_convert.php on line 1090
PHP message: PHP Notice:  Undefined index: Firstname

you can see in the 3rd line from the bottom that the buffer limit was hit, broke, and the next thread wrote in over it. Nginx then closed the connection and returned 502 to the client.

2: log all the headers sent per request, review them and make sure they conform to standards (nginx does not permit anything older than 24 hours to delete/expire a cookie, sending invalid content length because error messages were buffered before the content counted...). getallheaders function call can usually help out in abstracted code situations php get all headers

examples include:

<?php
//expire cookie
setcookie ( 'bookmark', '', strtotime('2012-01-01 00:00:00') );
// nginx will refuse this header response, too far past to accept
....
?>

and this:

<?php
header('Content-type: image/jpg');
?>

<?php   //a space was injected into the output above this line
header('Content-length: ' . filesize('image.jpg') );
echo file_get_contents('image.jpg');
// error! the response is now 1-byte longer than header!!
?>

1: verify, or make a script log, to ensure your thread is reaching the correct end point and not exiting before completion.

Create a menu Bar in WPF?

Yes, a menu gives you the bar but it doesn't give you any items to put in the bar. You need something like (from one of my own projects):

<!-- Menu. -->
<Menu Width="Auto" Height="20" Background="#FFA9D1F4" DockPanel.Dock="Top">
    <MenuItem Header="_Emulator">
    <MenuItem Header="Load..." Click="MenuItem_Click" />
    <MenuItem Header="Load again" Click="menuEmulLoadLast" />
    <Separator />
    <MenuItem Click="MenuItem_Click">
        <MenuItem.Header>
            <DockPanel>
                <TextBlock>Step</TextBlock>
                <TextBlock Width="10"></TextBlock>
                <TextBlock HorizontalAlignment="Right">F2</TextBlock>
            </DockPanel>
        </MenuItem.Header>
    </MenuItem>
    :

How to deal with certificates using Selenium?

Creating a profile and then a driver helps us get around the certificate issue in Firefox:

var profile = new FirefoxProfile();
profile.SetPreference("network.automatic-ntlm-auth.trusted-uris","DESIREDURL");
driver = new FirefoxDriver(profile);

Why is the Java main method static?

If the main method would not be static, you would need to create an object of your main class from outside the program. How would you want to do that?

error: use of deleted function

The error message clearly says that the default constructor has been deleted implicitly. It even says why: the class contains a non-static, const variable, which would not be initialized by the default ctor.

class X {
    const int x;
};

Since X::x is const, it must be initialized -- but a default ctor wouldn't normally initialize it (because it's a POD type). Therefore, to get a default ctor, you need to define one yourself (and it must initialize x). You can get the same kind of situation with a member that's a reference:

class X { 
    whatever &x;
};

It's probably worth noting that both of these will also disable implicit creation of an assignment operator as well, for essentially the same reason. The implicit assignment operator normally does members-wise assignment, but with a const member or reference member, it can't do that because the member can't be assigned. To make assignment work, you need to write your own assignment operator.

This is why a const member should typically be static -- when you do an assignment, you can't assign the const member anyway. In a typical case all your instances are going to have the same value so they might as well share access to a single variable instead of having lots of copies of a variable that will all have the same value.

It is possible, of course, to create instances with different values though -- you (for example) pass a value when you create the object, so two different objects can have two different values. If, however, you try to do something like swapping them, the const member will retain its original value instead of being swapped.

Difference between HttpModule and HttpClientModule

Use the HttpClient class from HttpClientModule if you're using Angular 4.3.x and above:

import { HttpClientModule } from '@angular/common/http';

@NgModule({
 imports: [
   BrowserModule,
   HttpClientModule
 ],
 ...

 class MyService() {
    constructor(http: HttpClient) {...}

It's an upgraded version of http from @angular/http module with the following improvements:

  • Interceptors allow middleware logic to be inserted into the pipeline
  • Immutable request/response objects
  • Progress events for both request upload and response download

You can read about how it works in Insider’s guide into interceptors and HttpClient mechanics in Angular.

  • Typed, synchronous response body access, including support for JSON body types
  • JSON is an assumed default and no longer needs to be explicitly parsed
  • Post-request verification & flush based testing framework

Going forward the old http client will be deprecated. Here are the links to the commit message and the official docs.

Also pay attention that old http was injected using Http class token instead of the new HttpClient:

import { HttpModule } from '@angular/http';

@NgModule({
 imports: [
   BrowserModule,
   HttpModule
 ],
 ...

 class MyService() {
    constructor(http: Http) {...}

Also, new HttpClient seem to require tslib in runtime, so you have to install it npm i tslib and update system.config.js if you're using SystemJS:

map: {
     ...
    'tslib': 'npm:tslib/tslib.js',

And you need to add another mapping if you use SystemJS:

'@angular/common/http': 'npm:@angular/common/bundles/common-http.umd.js',

How to stop creating .DS_Store on Mac?

Please install http://asepsis.binaryage.com/ and then reboot your mac.

ASEPSIS redirect all .DS_Store on your mac to /usr/local/.dscage

After that, You could delete recursively all .DS_Store from your mac.

find ~ -name ".DS_Store" -delete
or
find <your path> -name ".DS_Store" -delete

You should repeat procedure after each Mac major update.

Replace or delete certain characters from filenames of all files in a folder

A one-liner command in Windows PowerShell to delete or rename certain characters will be as below. (here the whitespace is being replaced with underscore)

Dir | Rename-Item –NewName { $_.name –replace " ","_" }

Difference between dangling pointer and memory leak

A dangling pointer is one that has a value (not NULL) which refers to some memory which is not valid for the type of object you expect. For example if you set a pointer to an object then overwrote that memory with something else unrelated or freed the memory if it was dynamically allocated.

A memory leak is when you dynamically allocate memory from the heap but never free it, possibly because you lost all references to it.

They are related in that they are both situations relating to mismanaged pointers, especially regarding dynamically allocated memory. In one situation (dangling pointer) you have likely freed the memory but tried to reference it afterwards; in the other (memory leak), you have forgotten to free the memory entirely!

angular2 manually firing click event on particular element

To get the native reference to something like an ion-input, ry using this

@ViewChild('fileInput', { read: ElementRef }) fileInput: ElementRef;

and then

this.fileInput.nativeElement.querySelector('input').click()

Changing default startup directory for command prompt in Windows 7

regedit worked great. HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\Command Processor, all you have to do is change the AutoRun key value, which is already set to wherever you are currently getting dumped into to a new value in the format of:

cd /d <drive:path>

for c:\, that would be cd /d c:\
for junk, that would be cd d/ c:\junk

its very simple, even a novice thats never used regedit should be able to figure it out. if not, go to the c:\prompt and just type in regedit, then follow the path to the key.

How to print the array?

If you want to print the array like you print a 2D list in Python:

#include <stdio.h>

int main()
{
  int i, j;
  int my_array[3][3] = {{10, 23, 42}, {1, 654, 0}, {40652, 22, 0}};
  for(i = 0; i < 3; i++)
  {
      if (i == 0) {
          printf("[");
      }
      printf("[");
      for(j = 0; j < 3; j++)
      {
         printf("%d", my_array[i][j]);
         if (j < 2) {
             printf(", ");
         }
      }
    printf("]");
    if (i == 2) {
        printf("]");
    }

    if (i < 2) {
        printf(", ");
    }
  }
  return 0;
}

Output will be:

[[10, 23, 42], [1, 654, 0], [40652, 22, 0]]

How to create a JSON object

Usually, you would do something like this:

$post_data = json_encode(array('item' => $post_data));

But, as it seems you want the output to be with "{}", you better make sure to force json_encode() to encode as object, by passing the JSON_FORCE_OBJECT constant.

$post_data = json_encode(array('item' => $post_data), JSON_FORCE_OBJECT);

"{}" brackets specify an object and "[]" are used for arrays according to JSON specification.

Create a new file in git bash

This is a very simple to create file in git bash at first write touch then file name with extension

for example

touch filename.extension

Set background color of WPF Textbox in C# code

textBox1.Background = Brushes.Blue;
textBox1.Foreground = Brushes.Yellow;

WPF Foreground and Background is of type System.Windows.Media.Brush. You can set another color like this:

using System.Windows.Media;

textBox1.Background = Brushes.White;
textBox1.Background = new SolidColorBrush(Colors.White);
textBox1.Background = new SolidColorBrush(Color.FromArgb(0xFF, 0xFF, 0, 0));
textBox1.Background = System.Windows.SystemColors.MenuHighlightBrush;

how to get html content from a webview?

In KitKat and above, you could use evaluateJavascript method on webview

wvbrowser.evaluateJavascript(
        "(function() { return ('<html>'+document.getElementsByTagName('html')[0].innerHTML+'</html>'); })();",
         new ValueCallback<String>() {
            @Override
            public void onReceiveValue(String html) {
                Log.d("HTML", html); 
                // code here
            }
    });

See this answer for more examples

JPA: difference between @JoinColumn and @PrimaryKeyJoinColumn?

What happens if I promote the column to be a/the PK, too (a.k.a. identifying relationship)? As the column is now the PK, I must tag it with @Id (...).

This enhanced support of derived identifiers is actually part of the new stuff in JPA 2.0 (see the section 2.4.1 Primary Keys Corresponding to Derived Identities in the JPA 2.0 specification), JPA 1.0 doesn't allow Id on a OneToOne or ManyToOne. With JPA 1.0, you'd have to use PrimaryKeyJoinColumn and also define a Basic Id mapping for the foreign key column.

Now the question is: are @Id + @JoinColumn the same as just @PrimaryKeyJoinColumn?

You can obtain a similar result but using an Id on OneToOne or ManyToOne is much simpler and is the preferred way to map derived identifiers with JPA 2.0. PrimaryKeyJoinColumn might still be used in a JOINED inheritance strategy. Below the relevant section from the JPA 2.0 specification:

11.1.40 PrimaryKeyJoinColumn Annotation

The PrimaryKeyJoinColumn annotation specifies a primary key column that is used as a foreign key to join to another table.

The PrimaryKeyJoinColumn annotation is used to join the primary table of an entity subclass in the JOINED mapping strategy to the primary table of its superclass; it is used within a SecondaryTable annotation to join a secondary table to a primary table; and it may be used in a OneToOne mapping in which the primary key of the referencing entity is used as a foreign key to the referenced entity[108].

...

If no PrimaryKeyJoinColumn annotation is specified for a subclass in the JOINED mapping strategy, the foreign key columns are assumed to have the same names as the primary key columns of the primary table of the superclass.

...

Example: Customer and ValuedCustomer subclass

@Entity
@Table(name="CUST")
@Inheritance(strategy=JOINED)
@DiscriminatorValue("CUST")
public class Customer { ... }

@Entity
@Table(name="VCUST")
@DiscriminatorValue("VCUST")
@PrimaryKeyJoinColumn(name="CUST_ID")
public class ValuedCustomer extends Customer { ... }

[108] The derived id mechanisms described in section 2.4.1.1 are now to be preferred over PrimaryKeyJoinColumn for the OneToOne mapping case.

See also


This source http://weblogs.java.net/blog/felipegaucho/archive/2009/10/24/jpa-join-table-additional-state states that using @ManyToOne and @Id works with JPA 1.x. Who's correct now?

The author is using a pre release JPA 2.0 compliant version of EclipseLink (version 2.0.0-M7 at the time of the article) to write an article about JPA 1.0(!). This article is misleading, the author is using something that is NOT part of JPA 1.0.

For the record, support of Id on OneToOne and ManyToOne has been added in EclipseLink 1.1 (see this message from James Sutherland, EclipseLink comitter and main contributor of the Java Persistence wiki book). But let me insist, this is NOT part of JPA 1.0.

how to increase java heap memory permanently?

if you need to increase reserved memory, there are VM parameters -Xms and -Xmx, usage e.g. -Xms512m -Xmx512m . There is also parameter -XX:MaxPermSize=256m which changes memory reserved for permanent generation

If your application runs as windows service, in Control panels -> Administration tools -> Services you can add some run parameters to your service

React-Native: Module AppRegistry is not a registered callable module

I had this issue - across iOS & Android, developing on Mac - after I had been fiddling with a dependency's code in the node_modules dir.

I solved it with:

rm -rf node_modules
npm i
npx pod-install ios

Which basically just re-installs your dependencies fresh.

Oracle insert from select into table with more columns

just select '0' as the value for the desired column

Json.net serialize/deserialize derived types?

Use this JsonKnownTypes, it's very similar way to use, it just add discriminator to json:

[JsonConverter(typeof(JsonKnownTypeConverter<BaseClass>))]
[JsonKnownType(typeof(Base), "base")]
[JsonKnownType(typeof(Derived), "derived")]
public class Base
{
    public string Name;
}
public class Derived : Base
{
    public string Something;
}

Now when you serialize object in json will be add "$type" with "base" and "derived" value and it will be use for deserialize

Serialized list example:

[
    {"Name":"some name", "$type":"base"},
    {"Name":"some name", "Something":"something", "$type":"derived"}
]

Android get image path from drawable as string

I think you cannot get it as String but you can get it as int by get resource id:

int resId = this.getResources().getIdentifier("imageNameHere", "drawable", this.getPackageName());

SQL Server: how to create a stored procedure

Create this way.

Create procedure dept_count(dept_name varchar(20),d_count integer)
   begin
     select count(*) into d_count
     from instructor
     where instructor.dept_name=dept_count.dept_name
   end

Tensorflow installation error: not a supported wheel on this platform

I was trying to install CPU TF on Ubuntu 18.04, and the best way (for me...) I found for it was using it on top of Conda, for that:

  1. To create Conda ‘tensorflow’ env. Follow https://linuxize.com/post/how-to-install-anaconda-on-ubuntu-18-04/

  2. After all installed see https://conda.io/projects/conda/en/latest/user-guide/getting-started.html And use it according to https://docs.conda.io/projects/conda/en/latest/user-guide/tasks/manage-environments.html#managing-environments

  3. conda create --name tensorflow

  4. source activate tensorflow

  5. pip install --upgrade pip

  6. pip uninstall tensorflow

  7. For CPU: pip install tensorflow-cpu, for GPU: pip install tensorflow

  8. pip install --ignore-installed --upgrade tensorflow

  9. Test TF E.g. on 'Where' with:

python

import tensorflow as tf

tf.where([[True, False], [False, True]])

expected result:

<tf.Tensor: shape=(2, 2), dtype=int64, numpy=
array([[0, 0],
       [1, 1]])>
  • After Conda upgrade I got: DeprecationWarning: 'source deactivate' is deprecated. Use 'conda deactivate'.

So you should use:

‘conda activate tensorflow’ / ‘conda deactivate’

How to get Django and ReactJS to work together?

The first approach is building separate Django and React apps. Django will be responsible for serving the API built using Django REST framework and React will consume these APIs using the Axios client or the browser's fetch API. You'll need to have two servers, both in development and production, one for Django(REST API) and the other for React (to serve static files).

The second approach is different the frontend and backend apps will be coupled. Basically you'll use Django to both serve the React frontend and to expose the REST API. So you'll need to integrate React and Webpack with Django, these are the steps that you can follow to do that

First generate your Django project then inside this project directory generate your React application using the React CLI

For Django project install django-webpack-loader with pip:

pip install django-webpack-loader

Next add the app to installed apps and configure it in settings.py by adding the following object

WEBPACK_LOADER = {
    'DEFAULT': {
            'BUNDLE_DIR_NAME': '',
            'STATS_FILE': os.path.join(BASE_DIR, 'webpack-stats.json'),
        }
}

Then add a Django template that will be used to mount the React application and will be served by Django

{ % load render_bundle from webpack_loader % }

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width" />
    <title>Django + React </title>
  </head>
  <body>
    <div id="root">
     This is where React will be mounted
    </div>
    { % render_bundle 'main' % }
  </body>
</html>

Then add an URL in urls.py to serve this template

from django.conf.urls import url
from django.contrib import admin
from django.views.generic import TemplateView

urlpatterns = [

    url(r'^', TemplateView.as_view(template_name="main.html")),

]

If you start both the Django and React servers at this point you'll get a Django error saying the webpack-stats.json doesn't exist. So next you need to make your React application able to generate the stats file.

Go ahead and navigate inside your React app then install webpack-bundle-tracker

npm install webpack-bundle-tracker --save

Then eject your Webpack configuration and go to config/webpack.config.dev.js then add

var BundleTracker  = require('webpack-bundle-tracker');
//...

module.exports = {

    plugins: [
          new BundleTracker({path: "../", filename: 'webpack-stats.json'}),
    ]
}

This add BundleTracker plugin to Webpack and instruct it to generate webpack-stats.json in the parent folder.

Make sure also to do the same in config/webpack.config.prod.js for production.

Now if you re-run your React server the webpack-stats.json will be generated and Django will be able to consume it to find information about the Webpack bundles generated by React dev server.

There are some other things to. You can find more information from this tutorial.

How to load html string in a webview?

I had the same requirement and I have done this in following way.You also can try out this..

Use loadData method

web.loadData("<p style='text-align:center'><img class='aligncenter size-full wp-image-1607' title='' src="+movImage+" alt='' width='240px' height='180px' /></p><p><center><U><H2>"+movName+"("+movYear+")</H2></U></center></p><p><strong>Director : </strong>"+movDirector+"</p><p><strong>Producer : </strong>"+movProducer+"</p><p><strong>Character : </strong>"+movActedAs+"</p><p><strong>Summary : </strong>"+movAnecdotes+"</p><p><strong>Synopsis : </strong>"+movSynopsis+"</p>\n","text/html", "UTF-8");

movDirector movProducer like all are my string variable.

In short i retain custom styling for my url.

Concatenate two JSON objects

The actual way is using JS Object.assign.

Object.assign(target, ...sources)

MDN Link

There is another object spread operator which is proposed for ES7 and can be used with Babel plugins.

 Obj = {...sourceObj1, ...sourceObj2}

ng serve not detecting file changes automatically

I had the same problem, using sudo ng serve seemed to "solve" the problem unsatisfactorily. Using sudo is not satisfactory IMO.

I checked my INotify count versus my default limit (8192) using: lsof | grep inotify | wc -l The value returned by the above command was way less than the limit. So the INotify solution didn't seem to apply to my problem.

I also checked permissions and ownership, both seemed ok, comparable to another project that worked.

Out of frustration I restarted VS Code. Basically I closed all instances, I had two running and re-opened both following which the problem went away.

I am leaning towards a possible bug somewhere. This is something to consider before turning your system inside out. Fortunately/Unfortunately this problem hasn't occurred again, I'll dig deeper if it does.

send Content-Type: application/json post with node.js

Simple Example

var request = require('request');

//Custom Header pass
var headersOpt = {  
    "content-type": "application/json",
};
request(
        {
        method:'post',
        url:'https://www.googleapis.com/urlshortener/v1/url', 
        form: {name:'hello',age:25}, 
        headers: headersOpt,
        json: true,
    }, function (error, response, body) {  
        //Print the Response
        console.log(body);  
}); 

How to add spacing between columns?

Create a class and use:

margin: 1.5em .5em; max-width: calc(50% - 1em)!important;

Where 1em on the max-width is equal to the left/right margin added together.

Click to call html

tl;dr What to do in modern (2018) times? Assume tel: is supported, use it and forget about anything else.


The tel: URI scheme RFC5431 (as well as sms: but also feed:, maps:, youtube: and others) is handled by protocol handlers (as mailto: and http: are).

They're unrelated to HTML5 specification (it has been out there from 90s and documented first time back in 2k with RFC2806) then you can't check for their support using tools as modernizr. A protocol handler may be installed by an application (for example Skype installs a callto: protocol handler with same meaning and behaviour of tel: but it's not a standard), natively supported by browser or installed (with some limitations) by website itself.

What HTML5 added is support for installing custom web based protocol handlers (with registerProtocolHandler() and related functions) simplifying also the check for their support through isProtocolHandlerRegistered() function.

There is some easy ways to determine if there is an handler or not:" How to detect browser's protocol handlers?).

In general what I suggest is:

  1. If you're running on a mobile device then you can safely assume tel: is supported (yes, it's not true for very old devices but IMO you can ignore them).
  2. If JS isn't active then do nothing.
  3. If you're running on desktop browsers then you can use one of the techniques in the linked post to determine if it's supported.
  4. If tel: isn't supported then change links to use callto: and repeat check desctibed in 3.
  5. If tel: and callto: aren't supported (or - in a desktop browser - you can't detect their support) then simply remove that link replacing URL in href with javascript:void(0) and (if number isn't repeated in text span) putting, telephone number in title. Here HTML5 microdata won't help users (just search engines). Note that newer versions of Skype handle both callto: and tel:.

Please note that (at least on latest Windows versions) there is always a - fake - registered protocol handler called App Picker (that annoying window that let you choose with which application you want to open an unknown file). This may vanish your tests so if you don't want to handle Windows environment as a special case you can simplify this process as:

  1. If you're running on a mobile device then assume tel: is supported.
  2. If you're running on desktop then replace tel: with callto:. then drop tel: or leave it as is (assuming there are good chances Skype is installed).

Get and Set a Single Cookie with Node.js HTTP Server

Using Some ES5/6 Sorcery & RegEx Magic

Here is an option to read the cookies and turn them into an object of Key, Value pairs for client side, could also use it server side.

Note: If there is a = in the value, no worries. If there is an = in the key, trouble in paradise.

More Notes: Some may argue readability so break it down as you like.

I Like Notes: Adding an error handler (try catch) wouldn't hurt.

const iLikeCookies = () => {
    return Object.fromEntries(document.cookie.split('; ').map(v => v.split(/=(.+)/))); 
}

const main = () => {
    // Add Test Cookies
    document.cookie = `name=Cookie Monster;expires=false;domain=localhost`
    document.cookie = `likesCookies=yes=withARandomEquals;expires=false;domain=localhost`;

    // Show the Objects
    console.log(document.cookie)
    console.log('The Object:', iLikeCookies())

    // Get a value from key
    console.log(`Username: ${iLikeCookies().name}`)
    console.log(`Enjoys Cookies: ${iLikeCookies().likesCookies}`)
}

enter image description here

What is going on?

iLikeCookies() will split the cookies by ; (space after ;):

["name=Cookie Monster", "likesCookies=yes=withARandomEquals"]

Then we map that array and split by first occurrence of = using regex capturing parens:

[["name", "Cookie Monster"], ["likesCookies", "yes=withARandomEquals"]]

Then use our friend `Object.fromEntries to make this an object of key, val pairs.

Nooice.

Run a PHP file in a cron job using CPanel

In crontab system :

  • /usr/bin/php is php binary path (different in some systems ex: freebsd /usr/local/bin/php, linux: /usr/bin/php)
  • /home/username/public_html/cron/cron.php should be your php script path
  • /dev/null should be cron output , ex: /home/username/stdoutx.txt

So you can monitor your cron by viewing cron output /home/username/stdoutx.txt

Get current URL from IFRAME

I had an issue with blob url hrefs. So, with a reference to the iframe, I just produced an url from the iframe's src attribute:

    const iframeReference = document.getElementById("iframe_id");
    const iframeUrl = iframeReference ? new URL(iframeReference.src) : undefined;
    if (iframeUrl) {
        console.log("Voila: " + iframeUrl);
    } else {
        console.warn("iframe with id iframe_id not found");
    }

fill an array in C#

public static void Fill<T>(this IList<T> col, T value, int fromIndex, int toIndex)
{
    if (fromIndex > toIndex)
        throw new ArgumentOutOfRangeException("fromIndex");

    for (var i = fromIndex; i <= toIndex; i++)
        col[i] = value;
}

Something that works for all IList<T>s.

How to retrieve a user environment variable in CMake (Windows)

Getting variables into your CMake script

You can pass a variable on the line with the cmake invocation:

FOO=1 cmake

or by exporting a variable in BASH:

export FOO=1

Then you can pick it up in a cmake script using:

$ENV{FOO}

How to allow access outside localhost

Open cmd and navigate to project location i.e. where you run npm install or ng serve for the project.

and then run the command - ng serve --host 10.202.32.45 where 10.202.32.45 is your IP address.

You will be able to access your page at 10.202.32.45:4200 where 4200 is your port number.

Note: If you serve your app using this command then you won't be able to access localhost:4200

How to compare numbers in bash?

I solved this by using a small function to convert version strings to plain integer values that can be compared:

function versionToInt() {
  local IFS=.
  parts=($1)
  let val=1000000*parts[0]+1000*parts[1]+parts[2]
  echo $val
}

This makes two important assumptions:

  1. Input is a "normal SemVer string"
  2. Each part is between 0-999

For example

versionToInt 12.34.56  # --> 12034056
versionToInt 1.2.3     # -->  1002003

Example testing whether npm command meets minimum requirement ...

NPM_ACTUAL=$(versionToInt $(npm --version))  # Capture npm version
NPM_REQUIRED=$(versionToInt 4.3.0)           # Desired version
if [ $NPM_ACTUAL \< $NPM_REQUIRED ]; then
  echo "Please update to npm@latest"
  exit 1
fi

What does "hard coded" mean?

The antonym of Hard-Coding is Soft-Coding. For a better understanding of Hard Coding, I will introduce both terms.

  • Hard-coding: feature is coded to the system not allowing for configuration;
  • Parametric: feature is configurable via table driven, or properties files with limited parametric values ;
  • Soft-coding: feature uses “engines” that derive results based on any number of parametric values (e.g. business rules in BRE); rules are coded but exist as parameters in system, written in script form

Examples:

// firstName has a hard-coded value of "hello world"
string firstName = "hello world";

// firstName has a non-hard-coded provided as input
Console.WriteLine("first name :");
string firstName = Console.ReadLine();

A hard-coded constant[1]:

float areaOfCircle(int radius)
{
    float area = 0;
    area = 3.14*radius*radius;  //  3.14 is a hard-coded value
    return area;
}

Additionally, hard-coding and soft-coding could be considered to be anti-patterns[2]. Thus, one should strive for balance between hard and soft-coding.

  1. Hard CodingHard coding” is a well-known antipattern against which most web development books warns us right in the preface. Hard coding is the unfortunate practice in which we store configuration or input data, such as a file path or a remote host name, in the source code rather than obtaining it from a configuration file, a database, a user input, or another external source.

    The main problem with hard code is that it only works properly in a certain environment, and at any time the conditions change, we need to modify the source code, usually in multiple separate places.

  2. Soft Coding
    If we try very hard to avoid the pitfall of hard coding, we can easily run into another antipattern called “soft coding”, which is its exact opposite.

    In soft coding, we put things that should be in the source code into external sources, for example we store business logic in the database. The most common reason why we do so, is the fear that business rules will change in the future, therefore we will need to rewrite the code.

    In extreme cases, a soft coded program can become so abstract and convoluted that it is almost impossible to comprehend it (especially for new team members), and extremely hard to maintain and debug.

Sources and Citations:

1: Quora: What does hard-coded something mean in computer programming context?
2: Hongkiat: The 10 Coding Antipatterns You Must Avoid

Further Reading:

Software Engineering SE: Is it ever a good idea to hardcode values into our applications?
Wikipedia: Hardcoding
Wikipedia: Soft-coding

How to copy a folder via cmd?

xcopy  "C:\Documents and Settings\user\Desktop\?????????" "D:\Backup" /s /e /y /i

Probably the problem is the space.Try with quotes.

Python: Convert timedelta to int in a dataframe

The Series class has a pandas.Series.dt accessor object with several useful datetime attributes, including dt.days. Access this attribute via:

timedelta_series.dt.days

You can also get the seconds and microseconds attributes in the same way.

How to remove the URL from the printing page?

I have a trick to remove it from the print page in Firefox. Use this:

<html moznomarginboxes mozdisallowselectionprint>

In the html tag you have to use moznomarginboxes mozdisallowselectionprint. I am sure it will help you a lot.

"android.view.WindowManager$BadTokenException: Unable to add window" on buider.show()

I am creating Dialog in onCreate and using it with show and hide. For me the root cause was not dismissing onBackPressed, which was finishing the Home activity.

@Override
public void onBackPressed() {
new AlertDialog.Builder(this)
                .setTitle("Really Exit?")
                .setMessage("Are you sure you want to exit?")
                .setNegativeButton(android.R.string.no, null)
                .setPositiveButton(android.R.string.yes,
                        new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog,
                                    int which) {
                                Home.this.finish();
                                return;
                            }
                        }).create().show();

I was finishing the Home Activity onBackPressed without closing / dismissing my dialogs.

When I dismissed my dialogs the crash disappeared.

new AlertDialog.Builder(this)
                .setTitle("Really Exit?")
                .setMessage("Are you sure you want to exit?")
                .setNegativeButton(android.R.string.no, null)
                .setPositiveButton(android.R.string.yes,
                        new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog,
                                    int which) {
                                networkErrorDialog.dismiss() ;
                                homeLocationErrorDialog.dismiss() ;
                                currentLocationErrorDialog.dismiss() ;
                                Home.this.finish();
                                return;
                            }
                        }).create().show();

pip broke. how to fix DistributionNotFound error?

I replaced 0.8.1 in 0.8.2 in /usr/local/bin/pip and everything worked again.

__requires__ = 'pip==0.8.2'
import sys
from pkg_resources import load_entry_point

if __name__ == '__main__':
    sys.exit(
        load_entry_point('pip==0.8.2', 'console_scripts', 'pip')()
    )

I installed pip through easy_install which probably caused me this headache. I think this is how you should do it nowadays..

$ sudo apt-get install python-pip python-dev build-essential 
$ sudo pip install --upgrade pip 
$ sudo pip install --upgrade virtualenv

How can I make this try_files directive work?

a very common try_files line which can be applied on your condition is

location / {
    try_files $uri $uri/ /test/index.html;
}

you probably understand the first part, location / matches all locations, unless it's matched by a more specific location, like location /test for example

The second part ( the try_files ) means when you receive a URI that's matched by this block try $uri first, for example http://example.com/images/image.jpg nginx will try to check if there's a file inside /images called image.jpg if found it will serve it first.

Second condition is $uri/ which means if you didn't find the first condition $uri try the URI as a directory, for example http://example.com/images/, ngixn will first check if a file called images exists then it wont find it, then goes to second check $uri/ and see if there's a directory called images exists then it will try serving it.

Side note: if you don't have autoindex on you'll probably get a 403 forbidden error, because directory listing is forbidden by default.

EDIT: I forgot to mention that if you have index defined, nginx will try to check if the index exists inside this folder before trying directory listing.

Third condition /test/index.html is considered a fall back option, (you need to use at least 2 options, one and a fall back), you can use as much as you can (never read of a constriction before), nginx will look for the file index.html inside the folder test and serve it if it exists.

If the third condition fails too, then nginx will serve the 404 error page.

Also there's something called named locations, like this

location @error {
}

You can call it with try_files like this

try_files $uri $uri/ @error;

TIP: If you only have 1 condition you want to serve, like for example inside folder images you only want to either serve the image or go to 404 error, you can write a line like this

location /images {
    try_files $uri =404;
}

which means either serve the file or serve a 404 error, you can't use only $uri by it self without =404 because you need to have a fallback option.
You can also choose which ever error code you want, like for example:

location /images {
    try_files $uri =403;
}

This will show a forbidden error if the image doesn't exist, or if you use 500 it will show server error, etc ..

jQuery - Add ID instead of Class

Try this:

$('element').attr('id', 'value');

So it becomes;

$(function() {
    $('span .breadcrumb').each(function(){
        $('#nav').attr('id', $(this).text());
        $('#container').attr('id', $(this).text());
        $('.stretch_footer').attr('id', $(this).text())
        $('#footer').attr('id', $(this).text());
    });
});

So you are changing/overwriting the id of three elements and adding an id to one element. You can modify as per you needs...

How to update record using Entity Framework Core?

It's super simple

using (var dbContext = new DbContextBuilder().BuildDbContext())
{
    dbContext.Update(entity);
    await dbContext.SaveChangesAsync();
}

How do you update a DateTime field in T-SQL?

When in doubt, be explicit about the data type conversion using CAST/CONVERT:

UPDATE TABLE
   SET EndDate = CAST('2009-05-25' AS DATETIME)
 WHERE Id = 1

How can I change the width and height of slides on Slick Carousel?

I found good solution myself. Since slick slider is still used nowadays i'll post my approach.

@RuivBoas answer is partly correct. - It can change the width of the slide but it can break the slider. Why?

Slick slider may exceed browser width. Actual container width is set to value that can accomodate all it's slides.

The best solution for setting slide width is to use width of the actual browser window. It works best with responsive design.

For example 2 slides with absorbed width

CSS

.slick-slide {
    width: 50vw;
    // for absorbing width from @Ken Wheeler answer
    box-sizing: border-box;
}

JS

$(document).on('ready', function () {
            $("#container").slick({
                variableWidth: true,
                slidesToShow: 2,
                slidesToScroll: 2
            });
        });

HTML markup

<div id="container">
    <div><img/></div>
    <div><img/></div>
    <div><img/></div>
</div>

How can I select and upload multiple files with HTML and PHP, using HTTP POST?

Full solution in Firefox 5:

<html>
<head>
</head>
<body>
 <form name="uploader" id="uploader" action="multifile.php" method="POST" enctype="multipart/form-data" >
  <input id="infile" name="infile[]" type="file" onBlur="submit();" multiple="true" ></input> 
 </form>

<?php
echo "No. files uploaded : ".count($_FILES['infile']['name'])."<br>"; 


$uploadDir = "images/";
for ($i = 0; $i < count($_FILES['infile']['name']); $i++) {

 echo "File names : ".$_FILES['infile']['name'][$i]."<br>";
 $ext = substr(strrchr($_FILES['infile']['name'][$i], "."), 1); 

 // generate a random new file name to avoid name conflict
 $fPath = md5(rand() * time()) . ".$ext";

 echo "File paths : ".$_FILES['infile']['tmp_name'][$i]."<br>";
 $result = move_uploaded_file($_FILES['infile']['tmp_name'][$i], $uploadDir . $fPath);

 if (strlen($ext) > 0){
  echo "Uploaded ". $fPath ." succefully. <br>";
 }
}
echo "Upload complete.<br>";
?>

</body>
</html>

UnicodeEncodeError: 'ascii' codec can't encode character u'\u2013' in position 3 2: ordinal not in range(128)

As here str(u'\u2013') is causing error so use isinstance(foo,basestring) to check for unicode/string, if not of type base string convert it into Unicode and then apply encode

if isinstance(foo,basestring):
    foo.encode('utf8')
else:
    unicode(foo).encode('utf8')

further read

Change :hover CSS properties with JavaScript

I'd recommend to replace all :hover properties to :active when you detect that device supports touch. Just call this function when you do so as touch()

   function touch() {
      if ('ontouchstart' in document.documentElement) {
        for (var sheetI = document.styleSheets.length - 1; sheetI >= 0; sheetI--) {
          var sheet = document.styleSheets[sheetI];
          if (sheet.cssRules) {
            for (var ruleI = sheet.cssRules.length - 1; ruleI >= 0; ruleI--) {
              var rule = sheet.cssRules[ruleI];

              if (rule.selectorText) {
                rule.selectorText = rule.selectorText.replace(':hover', ':active');
              }
            }
          }
        }
      }
    }

Difference between Mutable objects and Immutable objects

They are not different from the point of view of JVM. Immutable objects don't have methods that can change the instance variables. And the instance variables are private; therefore you can't change it after you create it. A famous example would be String. You don't have methods like setString, or setCharAt. And s1 = s1 + "w" will create a new string, with the original one abandoned. That's my understanding.

How to install MinGW-w64 and MSYS2?

MSYS has not been updated a long time, MSYS2 is more active, you can download from MSYS2, it has both mingw and cygwin fork package.

To install the MinGW-w64 toolchain (Reference):

  1. Open MSYS2 shell from start menu
  2. Run pacman -Sy pacman to update the package database
  3. Re-open the shell, run pacman -Syu to update the package database and core system packages
  4. Re-open the shell, run pacman -Su to update the rest
  5. Install compiler:
    • For 32-bit target, run pacman -S mingw-w64-i686-toolchain
    • For 64-bit target, run pacman -S mingw-w64-x86_64-toolchain
  6. Select which package to install, default is all
  7. You may also need make, run pacman -S make

Reading e-mails from Outlook with Python through MAPI

I have created my own iterator to iterate over Outlook objects via python. The issue is that python tries to iterates starting with Index[0], but outlook expects for first item Index[1]... To make it more Ruby simple, there is below a helper class Oli with following methods:

.items() - yields a tuple(index, Item)...

.prop() - helping to introspect outlook object exposing available properties (methods and attributes)

from win32com.client import constants
from win32com.client.gencache import EnsureDispatch as Dispatch

outlook = Dispatch("Outlook.Application")
mapi = outlook.GetNamespace("MAPI")

class Oli():
    def __init__(self, outlook_object):
        self._obj = outlook_object

    def items(self):
        array_size = self._obj.Count
        for item_index in xrange(1,array_size+1):
            yield (item_index, self._obj[item_index])

    def prop(self):
        return sorted( self._obj._prop_map_get_.keys() )

for inx, folder in Oli(mapi.Folders).items():
    # iterate all Outlook folders (top level)
    print "-"*70
    print folder.Name

    for inx,subfolder in Oli(folder.Folders).items():
        print "(%i)" % inx, subfolder.Name,"=> ", subfolder

How to convert a List<String> into a comma separated string without iterating List explicitly

With Java 8:

String csv = String.join(",", ids);

With Java 7-, there is a dirty way (note: it works only if you don't insert strings which contain ", " in your list) - obviously, List#toString will perform a loop to create idList but it does not appear in your code:

List<String> ids = new ArrayList<String>();
ids.add("1");
ids.add("2");
ids.add("3");
ids.add("4");
String idList = ids.toString();
String csv = idList.substring(1, idList.length() - 1).replace(", ", ",");

Tomcat Servlet: Error 404 - The requested resource is not available

this is may be due to the thing that you have created your .jsp or the .html file in the WEB-INF instead of the WebContent folder.

Solution: Just replace the files that are there in the WEB-INF folder to the Webcontent folder and try executing the same - You will get the appropriate output

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

Consider using subtree instead of submodules, it will make your repo users life much easier. You may find more detailed guide in Pro Git book.

Is it possible to get a history of queries made in postgres

If you want to identify slow queries, than the method is to use log_min_duration_statement setting (in postgresql.conf or set per-database with ALTER DATABASE SET).

When you logged the data, you can then use grep or some specialized tools - like pgFouine or my own analyzer - which lacks proper docs, but despite this - runs quite well.

Determine which MySQL configuration file is being used

Using MySQL Workbench it will be shown under "Server Status": enter image description here

Should you use .htm or .html file extension? What is the difference, and which file is correct?

I guess it's a little too late now however the only time it does make a difference is when you set up HTML signatures on MS Outlook (even 2010). It's just not able to handle .html extensions, only .htm

Simulate low network connectivity for Android

Very old post but I'll add my two cents. I have been VERY happy with this hardware product ( https://apposite-tech.com/products/linktropy-mini/ ) which has enabled us to simulate a lot of real-world conditions. For a long time we had challenges troubleshooting various things that would work in emulator or with airplane mode.

We have several different profiles setup from zero-connectivity to various stages of marginal connectivity, with different degrees of latency, packet loss, and bit-errors. The great thing about it is we can change these on the fly without having to relaunch the app in an emulator. The price has been entirely worth it for our shop, and it's dead simple to use.

XAMPP - MySQL shutdown unexpectedly

For this, you need to click on the x option under Modules Services and make MYSQL services installed. Then start the services. Here you go.

How to compare dates in c#

If you have your dates in DateTime variables, they don't have a format.

You can use the Date property to return a DateTime value with the time portion set to midnight. So, if you have:

DateTime dt1 = DateTime.Parse("07/12/2011");
DateTime dt2 = DateTime.Now;

if(dt1.Date > dt2.Date)
{
     //It's a later date
}
else
{
     //It's an earlier or equal date
}

Remove padding or margins from Google Charts

It's missing in the docs (I'm using version 43), but you can actually use the right and bottom property of the chart area:

var options = {
  chartArea:{
    left:10,
    right:10, // !!! works !!!
    bottom:20,  // !!! works !!!
    top:20,
    width:"100%",
    height:"100%"
  }
};

So it's possible to use full responsive width & height and prevent any axis labels or legends from being cropped.

Div not expanding even with content inside

Putting a <br clear="all" /> after the last floated div worked the best for me. Thanks to Brent Fiare & Paul Waite for the info that floated divs will not expand the height of the parent div! This has been driving me nuts! ;-}

How to add a Browse To File dialog to a VB.NET application

You're looking for the OpenFileDialog class.

For example:

Sub SomeButton_Click(sender As Object, e As EventArgs) Handles SomeButton.Click
    Using dialog As New OpenFileDialog
        If dialog.ShowDialog() <> DialogResult.OK Then Return
        File.Copy(dialog.FileName, newPath)
    End Using
End Sub

TypeError: 'NoneType' object has no attribute '__getitem__'

The function move.CompleteMove(events) that you use within your class probably doesn't contain a return statement. So nothing is returned to self.values (==> None). Use return in move.CompleteMove(events) to return whatever you want to store in self.values and it should work. Hope this helps.

SASS :not selector

I tried re-creating this, and .someclass.notip was being generated for me but .someclass:not(.notip) was not, for as long as I did not have the @mixin tip() defined. Once I had that, it all worked.

http://sassmeister.com/gist/9775949

$dropdown-width: 100px;
$comp-tip: true;

@mixin tip($pos:right) {

}

@mixin dropdown-pos($pos:right) {
  &:not(.notip) {
    @if $comp-tip == true{
      @if $pos == right {
        top:$dropdown-width * -0.6;
        background-color: #f00;
        @include tip($pos:$pos);
      }
    }
  }
  &.notip {
    @if $pos == right {
      top: 0;
      left:$dropdown-width * 0.8;
      background-color: #00f;
    }
  }
}

.someclass { @include dropdown-pos(); }

EDIT: http://sassmeister.com/ is a good place to debug your SASS because it gives you error messages. Undefined mixin 'tip'. it what I get when I remove @mixin tip($pos:right) { }

MVC 4 @Scripts "does not exist"

One more for the pot - spent ages trying to work out the same problem - even though it was defined in the web.config for root and the root of Views. Turns out I'd mistakenly added it to the <system.web><pages><namespaces>, and not <system.web**.webPages.razor**><pages><namespaces> element.

Really easy to miss that!

ExecuteNonQuery: Connection property has not been initialized.

A couple of things wrong here.

  1. Do you really want to open and close the connection for every single log entry?

  2. Shouldn't you be using SqlCommand instead of SqlDataAdapter?

  3. The data adapter (or SqlCommand) needs exactly what the error message tells you it's missing: an active connection. Just because you created a connection object does not magically tell C# that it is the one you want to use (especially if you haven't opened the connection).

I highly recommend a C# / SQL Server tutorial.

ASP.NET Bundles how to disable minification

If you set the following property to false then it will disable both bundling and minification.

In Global.asax.cs file, add the line as mentioned below

protected void Application_Start()
{
    System.Web.Optimization.BundleTable.EnableOptimizations = false;
}

What is the difference between a token and a lexeme?

a) Tokens are symbolic names for the entities that make up the text of the program; e.g. if for the keyword if, and id for any identifier. These make up the output of the lexical analyser. 5

(b) A pattern is a rule that specifies when a sequence of characters from the input constitutes a token; e.g the sequence i, f for the token if , and any sequence of alphanumerics starting with a letter for the token id.

(c) A lexeme is a sequence of characters from the input that match a pattern (and hence constitute an instance of a token); for example if matches the pattern for if , and foo123bar matches the pattern for id.

How to change button color with tkinter

When you do self.button = Button(...).grid(...), what gets assigned to self.button is the result of the grid() command, not a reference to the Button object created.

You need to assign your self.button variable before packing/griding it. It should look something like this:

self.button = Button(self,text="Click Me",command=self.color_change,bg="blue")
self.button.grid(row = 2, column = 2, sticky = W)

How does the @property decorator work in Python?

The property() function returns a special descriptor object:

>>> property()
<property object at 0x10ff07940>

It is this object that has extra methods:

>>> property().getter
<built-in method getter of property object at 0x10ff07998>
>>> property().setter
<built-in method setter of property object at 0x10ff07940>
>>> property().deleter
<built-in method deleter of property object at 0x10ff07998>

These act as decorators too. They return a new property object:

>>> property().getter(None)
<property object at 0x10ff079f0>

that is a copy of the old object, but with one of the functions replaced.

Remember, that the @decorator syntax is just syntactic sugar; the syntax:

@property
def foo(self): return self._foo

really means the same thing as

def foo(self): return self._foo
foo = property(foo)

so foo the function is replaced by property(foo), which we saw above is a special object. Then when you use @foo.setter(), what you are doing is call that property().setter method I showed you above, which returns a new copy of the property, but this time with the setter function replaced with the decorated method.

The following sequence also creates a full-on property, by using those decorator methods.

First we create some functions and a property object with just a getter:

>>> def getter(self): print('Get!')
... 
>>> def setter(self, value): print('Set to {!r}!'.format(value))
... 
>>> def deleter(self): print('Delete!')
... 
>>> prop = property(getter)
>>> prop.fget is getter
True
>>> prop.fset is None
True
>>> prop.fdel is None
True

Next we use the .setter() method to add a setter:

>>> prop = prop.setter(setter)
>>> prop.fget is getter
True
>>> prop.fset is setter
True
>>> prop.fdel is None
True

Last we add a deleter with the .deleter() method:

>>> prop = prop.deleter(deleter)
>>> prop.fget is getter
True
>>> prop.fset is setter
True
>>> prop.fdel is deleter
True

Last but not least, the property object acts as a descriptor object, so it has .__get__(), .__set__() and .__delete__() methods to hook into instance attribute getting, setting and deleting:

>>> class Foo: pass
... 
>>> prop.__get__(Foo(), Foo)
Get!
>>> prop.__set__(Foo(), 'bar')
Set to 'bar'!
>>> prop.__delete__(Foo())
Delete!

The Descriptor Howto includes a pure Python sample implementation of the property() type:

class Property:
    "Emulate PyProperty_Type() in Objects/descrobject.c"

    def __init__(self, fget=None, fset=None, fdel=None, doc=None):
        self.fget = fget
        self.fset = fset
        self.fdel = fdel
        if doc is None and fget is not None:
            doc = fget.__doc__
        self.__doc__ = doc

    def __get__(self, obj, objtype=None):
        if obj is None:
            return self
        if self.fget is None:
            raise AttributeError("unreadable attribute")
        return self.fget(obj)

    def __set__(self, obj, value):
        if self.fset is None:
            raise AttributeError("can't set attribute")
        self.fset(obj, value)

    def __delete__(self, obj):
        if self.fdel is None:
            raise AttributeError("can't delete attribute")
        self.fdel(obj)

    def getter(self, fget):
        return type(self)(fget, self.fset, self.fdel, self.__doc__)

    def setter(self, fset):
        return type(self)(self.fget, fset, self.fdel, self.__doc__)

    def deleter(self, fdel):
        return type(self)(self.fget, self.fset, fdel, self.__doc__)

What's the difference between Unicode and UTF-8?

It's not that simple.

UTF-16 is a 16-bit, variable-width encoding. Simply calling something "Unicode" is ambiguous, since "Unicode" refers to an entire set of standards for character encoding. Unicode is not an encoding!

http://en.wikipedia.org/wiki/Unicode#Unicode_Transformation_Format_and_Universal_Character_Set

and of course, the obligatory Joel On Software - The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!) link.

How to reset sequence in postgres and fill id column with new data?

FYI: If you need to specify a new startvalue between a range of IDs (256 - 10000000 for example):

SELECT setval('"Sequence_Name"', 
       (SELECT coalesce(MAX("ID"),255) 
           FROM "Table_Name" 
           WHERE "ID" < 10000000 and "ID" >= 256)+1
       ); 

How many times a substring occurs

j = 0
    while i < len(string):
        sub_string_out = string[i:len(sub_string)+j]
        if sub_string == sub_string_out:
            count += 1
        i += 1
        j += 1
    return count

Batch command to move files to a new directory

this will also work, if you like

 xcopy  C:\Test\Log "c:\Test\Backup-%date:~4,2%-%date:~7,2%-%date:~10,4%_%time:~0,2%%time:~3,2%" /s /i
 del C:\Test\Log

How to list the size of each file and directory and sort by descending size in Bash?

you can use the below to list files by size du -h | sort -hr | more or du -h --max-depth=0 * | sort -hr | more

How to get the current time in milliseconds in C Programming

If you're on a Unix-like system, use gettimeofday and convert the result from microseconds to milliseconds.

Border in shape xml

If you want make a border in a shape xml. You need to use:

For the external border,you need to use:

<stroke/>

For the internal background,you need to use:

<solid/>

If you want to set corners,you need to use:

<corners/>

If you want a padding betwen border and the internal elements,you need to use:

<padding/>

Here is a shape xml example using the above items. It works for me

<shape xmlns:android="http://schemas.android.com/apk/res/android"> 
  <stroke android:width="2dp" android:color="#D0CFCC" /> 
  <solid android:color="#F8F7F5" /> 
  <corners android:radius="10dp" />
  <padding android:left="2dp" android:top="2dp" android:right="2dp" android:bottom="2dp" />
</shape>

What is the "assert" function?

The assert() function can diagnose program bugs. In C, it is defined in <assert.h>, and in C++ it is defined in <cassert>. Its prototype is

void assert(int expression);

The argument expression can be anything you want to test--a variable or any C expression. If expression evaluates to TRUE, assert() does nothing. If expression evaluates to FALSE, assert() displays an error message on stderr and aborts program execution.

How do you use assert()? It is most frequently used to track down program bugs (which are distinct from compilation errors). A bug doesn't prevent a program from compiling, but it causes it to give incorrect results or to run improperly (locking up, for example). For instance, a financial-analysis program you're writing might occasionally give incorrect answers. You suspect that the problem is caused by the variable interest_rate taking on a negative value, which should never happen. To check this, place the statement

assert(interest_rate >= 0); at locations in the program where interest_rate is used. If the variable ever does become negative, the assert() macro alerts you. You can then examine the relevant code to locate the cause of the problem.

To see how assert() works, run the sample program below. If you enter a nonzero value, the program displays the value and terminates normally. If you enter zero, the assert() macro forces abnormal program termination. The exact error message you see will depend on your compiler, but here's a typical example:

Assertion failed: x, file list19_3.c, line 13 Note that, in order for assert() to work, your program must be compiled in debug mode. Refer to your compiler documentation for information on enabling debug mode (as explained in a moment). When you later compile the final version in release mode, the assert() macros are disabled.

 int x;

 printf("\nEnter an integer value: ");
 scanf("%d", &x);

 assert(x >= 0);

 printf("You entered %d.\n", x);
 return(0);

Enter an integer value: 10

You entered 10.

Enter an integer value: -1

Error Message: Abnormal program termination

Your error message might differ, depending on your system and compiler, but the general idea is the same.

Max or Default?

litt late, but I had the same concern...

Rephrasing your code from the original post, you want the max of the set S defined by

(From y In context.MyTable _
 Where y.MyField = value _
 Select y.MyCounter)

Taking in account your last comment

Suffice to say that I know I want 0 when there are no records to select from, which definitely has an impact on the eventual solution

I can rephrase your problem as: You want the max of {0 + S}. And it looks like the proposed solution with concat is semantically the right one :-)

var max = new[]{0}
          .Concat((From y In context.MyTable _
                   Where y.MyField = value _
                   Select y.MyCounter))
          .Max();

How to manipulate arrays. Find the average. Beginner Java

Try this way

public void average(int[] data) {  
    int sum = 0;
    double average;

    for(int i=0; i < data.length; i++){
        sum = sum + data[i];
    }
    average = (double)sum/data.length;
    System.out.println("Average value of array element is " + average);    
}

if you need to return average value you need to use double key word Instead of the void key word and need to return value return average.

public double average(int[] data) {  
    int sum = 0;
    double average;

    for(int i=0; i < data.length; i++){
        sum = sum + data[i];
    }
    average = (double)sum/data.length;
    return average;    
}

plot data from CSV file with matplotlib

According to the docs numpy.loadtxt is

a fast reader for simply formatted files. The genfromtxt function provides more sophisticated handling of, e.g., lines with missing values.

so there are only a few options to handle more complicated files. As mentioned numpy.genfromtxt has more options. So as an example you could use

import numpy as np
data = np.genfromtxt('e:\dir1\datafile.csv', delimiter=',', skip_header=10,
                     skip_footer=10, names=['x', 'y', 'z'])

to read the data and assign names to the columns (or read a header line from the file with names=True) and than plot it with

ax1.plot(data['x'], data['y'], color='r', label='the data')

I think numpy is quite well documented now. You can easily inspect the docstrings from within ipython or by using an IDE like spider if you prefer to read them rendered as HTML.

Show two digits after decimal point in c++

The easiest way to do this, is using cstdio's printf. Actually, i'm surprised that anyone mentioned printf! anyway, you need to include the library, like this...

#include<cstdio>

int main() {
    double total;
    cin>>total;
    printf("%.2f\n", total);
}

This will print the value of "total" (that's what %, and then ,total does) with 2 floating points (that's what .2f does). And the \n at the end, is just the end of line, and this works with UVa's judge online compiler options, that is:

g++ -lm -lcrypt -O2 -pipe -DONLINE_JUDGE filename.cpp

the code you are trying to run will not run with this compiler options...

Replace and overwrite instead of appending

See from How to Replace String in File works in a simple way and is an answer that works with replace

fin = open("data.txt", "rt")
fout = open("out.txt", "wt")

for line in fin:
    fout.write(line.replace('pyton', 'python'))

fin.close()
fout.close()

Is it possible to save HTML page as PDF using JavaScript or jquery?

Here is how I would do it, its an idea not bulletproof design, you need to modify it

  • The user clicks the save as PDF button
  • The server is sent a call using ajax
  • The server responds with a URL for PDF generated using HTML, I have used Apache FOP very succssfully
  • The js handling the ajax response does a location.href to point the URL send by JS and as soon as that URL loads, it sends the file using content disposition header as attachment forcing user to download the file.

Max size of an iOS application

With the release of iOS 7 (September 18th, 2013) apple increased the over-the-air cellular download limit to 100MBs.

Maximum app size remains 2GBs.

Source

How to insert tab character when expandtab option is on in Vim

You can use <CTRL-V><Tab> in "insert mode". In insert mode, <CTRL-V> inserts a literal copy of your next character.

If you need to do this often, @Dee`Kej suggested (in the comments) setting Shift+Tab to insert a real tab with this mapping:

:inoremap <S-Tab> <C-V><Tab>

Also, as noted by @feedbackloop, on Windows you may need to press <CTRL-Q> rather than <CTRL-V>.

Multiple conditions in WHILE loop

If your code, if the user enters 'X' (for instance), when you reach the while condition evaluation it will determine that 'X' is differente from 'n' (nChar != 'n') which will make your loop condition true and execute the code inside of your loop. The second condition is not even evaluated.

Spring MVC Controller redirect using URL parameters instead of in response

I had the same problem. solved it like this:

return new ModelAndView("redirect:/user/list?success=true");

And then my controller method look like this:

public ModelMap list(@RequestParam(required=false) boolean success) {
    ModelMap mm = new ModelMap();
    mm.put(SEARCH_MODEL_KEY, campaignService.listAllCampaigns());
    if(success)
        mm.put("successMessageKey", "campaign.form.msg.success");
    return mm;
}

Works perfectly unless you want to send simple data, not collections let's say. Then you'd have to use session I guess.