Programs & Examples On #Pulse

Use a.empty, a.bool(), a.item(), a.any() or a.all()

solution is easy:

replace

 mask = (50  < df['heart rate'] < 101 &
            140 < df['systolic blood pressure'] < 160 &
            90  < df['dyastolic blood pressure'] < 100 &
            35  < df['temperature'] < 39 &
            11  < df['respiratory rate'] < 19 &
            95  < df['pulse oximetry'] < 100
            , "excellent", "critical")

by

mask = ((50  < df['heart rate'] < 101) &
        (140 < df['systolic blood pressure'] < 160) &
        (90  < df['dyastolic blood pressure'] < 100) &
        (35  < df['temperature'] < 39) &
        (11  < df['respiratory rate'] < 19) &
        (95  < df['pulse oximetry'] < 100)
        , "excellent", "critical")

jQuery - Uncaught RangeError: Maximum call stack size exceeded

Your calls are made recursively which pushes functions on to the stack infinitely that causes max call stack exceeded error due to recursive behavior. Instead try using setTimeout which is a callback.

Also based on your markup your selector is wrong. it should be #advisersDiv

Demo

function fadeIn() {
    $('#pulseDiv').find('div#advisersDiv').delay(400).addClass("pulse");
    setTimeout(fadeOut,1); //<-- Provide any delay here
};

function fadeOut() {
    $('#pulseDiv').find('div#advisersDiv').delay(400).removeClass("pulse");
    setTimeout(fadeIn,1);//<-- Provide any delay here
};
fadeIn();

How do I convert certain columns of a data frame to become factors?

Here's an example:

#Create a data frame
> d<- data.frame(a=1:3, b=2:4)
> d
  a b
1 1 2
2 2 3
3 3 4

#currently, there are no levels in the `a` column, since it's numeric as you point out.
> levels(d$a)
NULL

#Convert that column to a factor
> d$a <- factor(d$a)
> d
  a b
1 1 2
2 2 3
3 3 4

#Now it has levels.
> levels(d$a)
[1] "1" "2" "3"

You can also handle this when reading in your data. See the colClasses and stringsAsFactors parameters in e.g. readCSV().

Note that, computationally, factoring such columns won't help you much, and may actually slow down your program (albeit negligibly). Using a factor will require that all values are mapped to IDs behind the scenes, so any print of your data.frame requires a lookup on those levels -- an extra step which takes time.

Factors are great when storing strings which you don't want to store repeatedly, but would rather reference by their ID. Consider storing a more friendly name in such columns to fully benefit from factors.

How to create a pulse effect using -webkit-animation - outward rings

You have a lot of unnecessary keyframes. Don't think of keyframes as individual frames, think of them as "steps" in your animation and the computer fills in the frames between the keyframes.

Here is a solution that cleans up a lot of code and makes the animation start from the center:

.gps_ring {
    border: 3px solid #999;
    -webkit-border-radius: 30px;
    height: 18px;
    width: 18px;
    position: absolute;
    left:20px;
    top:214px;
    -webkit-animation: pulsate 1s ease-out;
    -webkit-animation-iteration-count: infinite; 
    opacity: 0.0
}
@-webkit-keyframes pulsate {
    0% {-webkit-transform: scale(0.1, 0.1); opacity: 0.0;}
    50% {opacity: 1.0;}
    100% {-webkit-transform: scale(1.2, 1.2); opacity: 0.0;}
}

You can see it in action here: http://jsfiddle.net/Fy8vD/

How do I move an existing Git submodule within a Git repository?

The string in quotes after "[submodule" doesn't matter. You can change it to "foobar" if you want. It's used to find the matching entry in ".git/config".

Therefore, if you make the change before you run "git submodule init", it'll work fine. If you make the change (or pick up the change through a merge), you'll need to either manually edit .git/config or run "git submodule init" again. If you do the latter, you'll be left with a harmless "stranded" entry with the old name in .git/config.

Ball to Ball Collision - Detection and Handling

I implemented this code in JavaScript using the HTML Canvas element, and it produced wonderful simulations at 60 frames per second. I started the simulation off with a collection of a dozen balls at random positions and velocities. I found that at higher velocities, a glancing collision between a small ball and a much larger one caused the small ball to appear to STICK to the edge of the larger ball, and moved up to around 90 degrees around the larger ball before separating. (I wonder if anyone else observed this behavior.)

Some logging of the calculations showed that the Minimum Translation Distance in these cases was not large enough to prevent the same balls from colliding in the very next time step. I did some experimenting and found that I could solve this problem by scaling up the MTD based on the relative velocities:

dot_velocity = ball_1.velocity.dot(ball_2.velocity);
mtd_factor = 1. + 0.5 * Math.abs(dot_velocity * Math.sin(collision_angle));
mtd.multplyScalar(mtd_factor);

I verified that before and after this fix, the total kinetic energy was conserved for every collision. The 0.5 value in the mtd_factor was the approximately the minumum value found to always cause the balls to separate after a collision.

Although this fix introduces a small amount of error in the exact physics of the system, the tradeoff is that now very fast balls can be simulated in a browser without decreasing the time step size.

Calling a function from a string in C#

Yes. You can use reflection. Something like this:

Type thisType = this.GetType();
MethodInfo theMethod = thisType.GetMethod(TheCommandString);
theMethod.Invoke(this, userParameters);

How to get a table cell value using jQuery?

$('#mytable tr').each(function() {
    var customerId = $(this).find("td:first").html();    
});

What you are doing is iterating through all the trs in the table, finding the first td in the current tr in the loop, and extracting its inner html.

To select a particular cell, you can reference them with an index:

$('#mytable tr').each(function() {
    var customerId = $(this).find("td").eq(2).html();    
});

In the above code, I will be retrieving the value of the third row (the index is zero-based, so the first cell index would be 0)


Here's how you can do it without jQuery:

var table = document.getElementById('mytable'), 
    rows = table.getElementsByTagName('tr'),
    i, j, cells, customerId;

for (i = 0, j = rows.length; i < j; ++i) {
    cells = rows[i].getElementsByTagName('td');
    if (!cells.length) {
        continue;
    }
    customerId = cells[0].innerHTML;
}

?

Scheduling Python Script to run every hour accurately

   #For scheduling task execution
import schedule
import time

def job():
    print("I'm working...")

schedule.every(1).minutes.do(job)
#schedule.every().hour.do(job)
#schedule.every().day.at("10:30").do(job)
#schedule.every(5).to(10).minutes.do(job)
#schedule.every().monday.do(job)
#schedule.every().wednesday.at("13:15").do(job)
#schedule.every().minute.at(":17").do(job)

while True:
    schedule.run_pending()
    time.sleep(1)

Runnable with a parameter?

Since Java 8, the best answer is to use Consumer<T>:

https://docs.oracle.com/javase/8/docs/api/java/util/function/Consumer.html

It's one of the functional interfaces, which means you can call it as a lambda expression:

void doSomething(Consumer<String> something) {
    something.accept("hello!");
}

...

doSomething( (something) -> System.out.println(something) )

...

How do I return a string from a regex match in python?

Considering there might be several img tags I would recommend re.findall:

import re

with open("sample.txt", 'r') as f_in, open('writetest.txt', 'w') as f_out:
    for line in f_in:
        for img in re.findall('<img[^>]+>', line):
            print >> f_out, "yo it's a {}".format(img)

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

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

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

It works well.

Try to apply the same rule on your case.

How to place div side by side

There are many ways to do what you're asking for:

  1. Using CSS float property:

_x000D_
_x000D_
 <div style="width: 100%; overflow: hidden;">
     <div style="width: 600px; float: left;"> Left </div>
     <div style="margin-left: 620px;"> Right </div>
</div>
_x000D_
_x000D_
_x000D_

  1. Using CSS display property - which can be used to make divs act like a table:

_x000D_
_x000D_
<div style="width: 100%; display: table;">
    <div style="display: table-row">
        <div style="width: 600px; display: table-cell;"> Left </div>
        <div style="display: table-cell;"> Right </div>
    </div>
</div>
_x000D_
_x000D_
_x000D_

There are more methods, but those two are the most popular.

UTF-8, UTF-16, and UTF-32

Depending on your development environment you may not even have the choice what encoding your string data type will use internally.

But for storing and exchanging data I would always use UTF-8, if you have the choice. If you have mostly ASCII data this will give you the smallest amount of data to transfer, while still being able to encode everything. Optimizing for the least I/O is the way to go on modern machines.

get the data of uploaded file in javascript

The example below is based on the html5rocks solution. It uses the browser's FileReader() function. Newer browsers only.

See http://www.html5rocks.com/en/tutorials/file/dndfiles/#toc-reading-files

In this example, the user selects an HTML file. It uploaded into the <textarea>.

<form enctype="multipart/form-data">
<input id="upload" type=file   accept="text/html" name="files[]" size=30>
</form>

<textarea class="form-control" rows=35 cols=120 id="ms_word_filtered_html"></textarea>

<script>
function handleFileSelect(evt) {
    var files = evt.target.files; // FileList object

    // use the 1st file from the list
    f = files[0];

    var reader = new FileReader();

    // Closure to capture the file information.
    reader.onload = (function(theFile) {
        return function(e) {

          jQuery( '#ms_word_filtered_html' ).val( e.target.result );
        };
      })(f);

      // Read in the image file as a data URL.
      reader.readAsText(f);
  }

  document.getElementById('upload').addEventListener('change', handleFileSelect, false);
</script>

"Non-static method cannot be referenced from a static context" error

Instance methods need to be called from an instance. Your setLoanItem method is an instance method (it doesn't have the modifier static), which it needs to be in order to function (because it is setting a value on the instance that it's called on (this)).

You need to create an instance of the class before you can call the method on it:

Media media = new Media();
media.setLoanItem("Yes");

(Btw it would be better to use a boolean instead of a string containing "Yes".)

Applying CSS styles to all elements inside a DIV

#applyCSS > * {
  /* Your style */
}

Check this JSfiddle

It will style all children and grandchildren, but will exclude loosely flying text in the div itself and only target wrapped (by tags) content.

How do you create vectors with specific intervals in R?

In R the equivalent function is seq and you can use it with the option by:

seq(from = 5, to = 100, by = 5)
# [1]   5  10  15  20  25  30  35  40  45  50  55  60  65  70  75  80  85  90  95 100

In addition to by you can also have other options such as length.out and along.with.

length.out: If you want to get a total of 10 numbers between 0 and 1, for example:

seq(0, 1, length.out = 10)
# gives 10 equally spaced numbers from 0 to 1

along.with: It takes the length of the vector you supply as input and provides a vector from 1:length(input).

seq(along.with=c(10,20,30))
# [1] 1 2 3

Although, instead of using the along.with option, it is recommended to use seq_along in this case. From the documentation for ?seq

seq is generic, and only the default method is described here. Note that it dispatches on the class of the first argument irrespective of argument names. This can have unintended consequences if it is called with just one argument intending this to be taken as along.with: it is much better to use seq_along in that case.

seq_along: Instead of seq(along.with(.))

seq_along(c(10,20,30))
# [1] 1 2 3

Hope this helps.

What is difference between MVC, MVP & MVVM design pattern in terms of coding c#

Some basic differences can be written in short:

MVC:

Traditional MVC is where there is a

  1. Model: Acts as the model for data
  2. View : Deals with the view to the user which can be the UI
  3. Controller: Controls the interaction between Model and View, where view calls the controller to update model. View can call multiple controllers if needed.

MVP:

Similar to traditional MVC but Controller is replaced by Presenter. But the Presenter, unlike Controller is responsible for changing the view as well. The view usually does not call the presenter.

MVVM

The difference here is the presence of View Model. It is kind of an implementation of Observer Design Pattern, where changes in the model are represented in the view as well, by the VM. Eg: If a slider is changed, not only the model is updated but the data which may be a text, that is displayed in the view is updated as well. So there is a two-way data binding.

What's the equivalent of Java's Thread.sleep() in JavaScript?

For Best solution, Use async/await statement for ecma script 2017

await can use only inside of async function

function sleep(time) {
    return new Promise((resolve) => {
        setTimeout(resolve, time || 1000);
    });
}

await sleep(10000); //this method wait for 10 sec.

Note : async / await not actualy stoped thread like Thread.sleep but simulate it

Negative list index?

List indexes of -x mean the xth item from the end of the list, so n[-1] means the last item in the list n. Any good Python tutorial should have told you this.

It's an unusual convention that only a few other languages besides Python have adopted, but it is extraordinarily useful; in any other language you'll spend a lot of time writing n[n.length-1] to access the last item of a list.

When restoring a backup, how do I disconnect all active connections?

None of these were working for me, couldn't delete or disconnect current users. Also couldn't see any active connections to the DB. Restarting SQL Server (Right click and select Restart) allowed me to do it.

Owl Carousel Won't Autoplay

Yes, its a typing error.

Write

autoPlay

not

autoplay

The autoplay-plugin code defines the variable as "autoPlay".

How to Add Incremental Numbers to a New Column Using Pandas

import numpy as np

df['New_ID']=np.arange(880,880+len(df.Fruit))
df=df.reindex(columns=['New_ID','ID','Fruit'])

What is the difference between PUT, POST and PATCH?

Quite logical the difference between PUT & PATCH w.r.t sending full & partial data for replacing/updating respectively. However, just couple of points as below

  1. Sometimes POST is considered as for updates w.r.t PUT for create
  2. Does HTTP mandates/checks for sending full vs partial data in PATCH? Otherwise, PATCH may be quite same as update as in PUT/POST

Passing A List Of Objects Into An MVC Controller Method Using jQuery Ajax

Modification from @veeresh i

 var data=[

                        { id: 1, color: 'yellow' },
                        { id: 2, color: 'blue' },
                        { id: 3, color: 'red' }
                        ]; //parameter
        var para={};
        para.datav=data;   //datav from View


        $.ajax({
                    traditional: true,
                    url: "/Conroller/MethodTest",
                    type: "POST",
                    contentType: "application/json; charset=utf-8",
                    data:para,
                    success: function (data) {
                        $scope.DisplayError(data.requestStatus);
                    }
                });

In MVC



public class Thing
    {
        public int id { get; set; }
        public string color { get; set; }
    }

    public JsonResult MethodTest(IEnumerable<Thing> datav)
        {
       //now  datav is having all your values
      }

How do you detect Credit card type based on number?

Try this.For swift.

func checkCardValidation(number : String) -> Bool
{
    let reversedInts = number.characters.reversed().map { Int(String($0)) }
        return reversedInts.enumerated().reduce(0, {(sum, val) in
            let odd = val.offset % 2 == 1
            return sum + (odd ? (val.element! == 9 ? 9 : (val.element! * 2) % 9) : val.element!)
        }) % 10 == 0
}

Use.

if (self.checkCardValidation(number: "yourNumber") == true) {
     print("Card Number valid")
}else{
     print("Card Number not valid")
}

How to force two figures to stay on the same page in LaTeX?

If you want them both on the same page and they'll both take up basically the whole page, then the best idea is to tell LaTeX to put them both on a page of their own!

\begin{figure}[p]

It would probably be against sound typographic principles (e.g., ugly) to have two figures on a page with only a few lines of text above or below them.


By the way, the reason that [!h] works is because it's telling LaTeX to override its usual restrictions on how much space should be devoted to floats on a page with text. As implied above, there's a reason the restrictions are there. Which isn't to say they can be loosened somewhat; see the FAQ on doing that.

Getting the URL of the current page using Selenium WebDriver

Put sleep. It will work. I have tried. The reason is that the page wasn't loaded yet. Check this question to know how to wait for load - Wait for page load in Selenium

How is a CSS "display: table-column" supposed to work?

The CSS table model is based on the HTML table model http://www.w3.org/TR/CSS21/tables.html

A table is divided into ROWS, and each row contains one or more cells. Cells are children of ROWS, they are NEVER children of columns.

"display: table-column" does NOT provide a mechanism for making columnar layouts (e.g. newspaper pages with multiple columns, where content can flow from one column to the next).

Rather, "table-column" ONLY sets attributes that apply to corresponding cells within the rows of a table. E.g. "The background color of the first cell in each row is green" can be described.

The table itself is always structured the same way it is in HTML.

In HTML (observe that "td"s are inside "tr"s, NOT inside "col"s):

<table ..>
  <col .. />
  <col .. />
  <tr ..>
    <td ..></td>
    <td ..></td>
  </tr>
  <tr ..>
    <td ..></td>
    <td ..></td>
  </tr>
</table>

Corresponding HTML using CSS table properties (Note that the "column" divs do not contain any contents -- the standard does not allow for contents directly in columns):

_x000D_
_x000D_
.mytable {_x000D_
  display: table;_x000D_
}_x000D_
.myrow {_x000D_
  display: table-row;_x000D_
}_x000D_
.mycell {_x000D_
  display: table-cell;_x000D_
}_x000D_
.column1 {_x000D_
  display: table-column;_x000D_
  background-color: green;_x000D_
}_x000D_
.column2 {_x000D_
  display: table-column;_x000D_
}
_x000D_
<div class="mytable">_x000D_
  <div class="column1"></div>_x000D_
  <div class="column2"></div>_x000D_
  <div class="myrow">_x000D_
    <div class="mycell">contents of first cell in row 1</div>_x000D_
    <div class="mycell">contents of second cell in row 1</div>_x000D_
  </div>_x000D_
  <div class="myrow">_x000D_
    <div class="mycell">contents of first cell in row 2</div>_x000D_
    <div class="mycell">contents of second cell in row 2</div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_



OPTIONAL: both "rows" and "columns" can be styled by assigning multiple classes to each row and cell as follows. This approach gives maximum flexibility in specifying various sets of cells, or individual cells, to be styled:

_x000D_
_x000D_
//Useful css declarations, depending on what you want to affect, include:_x000D_
_x000D_
/* all cells (that have "class=mycell") */_x000D_
.mycell {_x000D_
}_x000D_
_x000D_
/* class row1, wherever it is used */_x000D_
.row1 {_x000D_
}_x000D_
_x000D_
/* all the cells of row1 (if you've put "class=mycell" on each cell) */_x000D_
.row1 .mycell {_x000D_
}_x000D_
_x000D_
/* cell1 of row1 */_x000D_
.row1 .cell1 {_x000D_
}_x000D_
_x000D_
/* cell1 of all rows */_x000D_
.cell1 {_x000D_
}_x000D_
_x000D_
/* row1 inside class mytable (so can have different tables with different styles) */_x000D_
.mytable .row1 {_x000D_
}_x000D_
_x000D_
/* all the cells of row1 of a mytable */_x000D_
.mytable .row1 .mycell {_x000D_
}_x000D_
_x000D_
/* cell1 of row1 of a mytable */_x000D_
.mytable .row1 .cell1 {_x000D_
}_x000D_
_x000D_
/* cell1 of all rows of a mytable */_x000D_
.mytable .cell1 {_x000D_
}
_x000D_
<div class="mytable">_x000D_
  <div class="column1"></div>_x000D_
  <div class="column2"></div>_x000D_
  <div class="myrow row1">_x000D_
    <div class="mycell cell1">contents of first cell in row 1</div>_x000D_
    <div class="mycell cell2">contents of second cell in row 1</div>_x000D_
  </div>_x000D_
  <div class="myrow row2">_x000D_
    <div class="mycell cell1">contents of first cell in row 2</div>_x000D_
    <div class="mycell cell2">contents of second cell in row 2</div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

In today's flexible designs, which use <div> for multiple purposes, it is wise to put some class on each div, to help refer to it. Here, what used to be <tr> in HTML became class myrow, and <td> became class mycell. This convention is what makes the above CSS selectors useful.

PERFORMANCE NOTE: putting class names on each cell, and using the above multi-class selectors, is better performance than using selectors ending with *, such as .row1 * or even .row1 > *. The reason is that selectors are matched last first, so when matching elements are being sought, .row1 * first does *, which matches all elements, and then checks all the ancestors of each element, to find if any ancestor has class row1. This might be slow in a complex document on a slow device. .row1 > * is better, because only the immediate parent is examined. But it is much better still to immediately eliminate most elements, via .row1 .cell1. (.row1 > .cell1 is an even tighter spec, but it is the first step of the search that makes the biggest difference, so it usually isn't worth the clutter, and the extra thought process as to whether it will always be a direct child, of adding the child selector >.)

The key point to take away re performance is that the last item in a selector should be as specific as possible, and should never be *.

Eclipse count lines of code

Another way would by to use another loc utility, like LocMetrics for instance.
It also lists many other loc tools. The integration with Eclipse wouldn't be always there (as it would be with Metrics2, which you can check out because it is a more recent version than Metrics), but at least those tools can reason in term of logical lines (computed by summing the terminal semicolons and terminal curly braces).
You can also check with eclipse-metrics is more adapted to what you expect.

getting the X/Y coordinates of a mouse click on an image with jQuery

Here is a better script:

$('#mainimage').click(function(e)
{   
    var offset_t = $(this).offset().top - $(window).scrollTop();
    var offset_l = $(this).offset().left - $(window).scrollLeft();

    var left = Math.round( (e.clientX - offset_l) );
    var top = Math.round( (e.clientY - offset_t) );

    alert("Left: " + left + " Top: " + top);

});

Interfaces with static fields in java for sharing 'constants'

It's generally considered bad practice. The problem is that the constants are part of the public "interface" (for want of a better word) of the implementing class. This means that the implementing class is publishing all of these values to external classes even when they are only required internally. The constants proliferate throughout the code. An example is the SwingConstants interface in Swing, which is implemented by dozens of classes that all "re-export" all of its constants (even the ones that they don't use) as their own.

But don't just take my word for it, Josh Bloch also says it's bad:

The constant interface pattern is a poor use of interfaces. That a class uses some constants internally is an implementation detail. Implementing a constant interface causes this implementation detail to leak into the class's exported API. It is of no consequence to the users of a class that the class implements a constant interface. In fact, it may even confuse them. Worse, it represents a commitment: if in a future release the class is modified so that it no longer needs to use the constants, it still must implement the interface to ensure binary compatibility. If a nonfinal class implements a constant interface, all of its subclasses will have their namespaces polluted by the constants in the interface.

An enum may be a better approach. Or you could simply put the constants as public static fields in a class that cannot be instantiated. This allows another class to access them without polluting its own API.

when exactly are we supposed to use "public static final String"?

This is related to the semantics of the code. By naming the value assigning it to a variable that has a meaningful name (even if it is used only at one place) you give it a meaning. When somebody is reading the code that person will know what that value means.

In general is not a good practice to use constant values across the code. Imagine a code full of string, integer, etc. values. After a time nobody will know what those constants are. Also a typo in a value can be a problem when the value is used on more than one place.

Javascript: How to check if a string is empty?

if (value == "") {
  // it is empty
}

MySQL: how to get the difference between two timestamps in seconds

How about "TIMESTAMPDIFF":

SELECT TIMESTAMPDIFF(SECOND,'2009-05-18','2009-07-29') from `post_statistics`

https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_timestampdiff

Why declare unicode by string in python?

I made the following module called unicoder to be able to do the transformation on variables:

import sys
import os

def ustr(string):

    string = 'u"%s"'%string

    with open('_unicoder.py', 'w') as script:

        script.write('# -*- coding: utf-8 -*-\n')
        script.write('_ustr = %s'%string)

    import _unicoder
    value = _unicoder._ustr

    del _unicoder
    del sys.modules['_unicoder']

    os.system('del _unicoder.py')
    os.system('del _unicoder.pyc')

    return value

Then in your program you could do the following:

# -*- coding: utf-8 -*-

from unicoder import ustr

txt = 'Hello, Unicode World'
txt = ustr(txt)

print type(txt) # <type 'unicode'>

How to pass query parameters with a routerLink

queryParams

queryParams is another input of routerLink where they can be passed like

<a [routerLink]="['../']" [queryParams]="{prop: 'xxx'}">Somewhere</a>

fragment

<a [routerLink]="['../']" [queryParams]="{prop: 'xxx'}" [fragment]="yyy">Somewhere</a>

routerLinkActiveOptions

To also get routes active class set on parent routes:

[routerLinkActiveOptions]="{ exact: false }"

To pass query parameters to this.router.navigate(...) use

let navigationExtras: NavigationExtras = {
  queryParams: { 'session_id': sessionId },
  fragment: 'anchor'
};

// Navigate to the login page with extras
this.router.navigate(['/login'], navigationExtras);

See also https://angular.io/guide/router#query-parameters-and-fragments

How to get maximum value from the Collection (for example ArrayList)?

Java 8

As integers are comparable we can use the following one liner in:

List<Integer> ints = Stream.of(22,44,11,66,33,55).collect(Collectors.toList());
Integer max = ints.stream().mapToInt(i->i).max().orElseThrow(NoSuchElementException::new); //66
Integer min = ints.stream().mapToInt(i->i).min().orElseThrow(NoSuchElementException::new); //11

Another point to note is we cannot use Funtion.identity() in place of i->i as mapToInt expects ToIntFunction which is a completely different interface and is not related to Function. Moreover this interface has only one method applyAsInt and no identity() method.

Which is the best Linux C/C++ debugger (or front-end to gdb) to help teaching programming?

You may want to check out Eclipse CDT. It provides a C/C++ IDE that runs on multiple platforms (e.g. Windows, Linux, Mac OS X, etc.). Debugging with Eclipse CDT is comparable to using other tools such as Visual Studio.

You can check out the Eclipse CDT Debug tutorial that also includes a number of screenshots.

Copy or rsync command

Especially if you use a copy-on-write filesystem like BTRFS or ZFS, rsync is much better.

I use BTRFS, and I have this in my ~/.bashrc:

alias cp="rsync -ah --inplace --no-whole-file --info=progress2"

The important flag here for CoW FSs like BTRFS is --inplace because it only copies the changed part of the files, doesn't create new for small changes between files inodes, etc. See this.

In SQL Server, how to create while loop in select

INSERT INTO Table2 SELECT DISTINCT ID,Data = STUFF((SELECT ', ' + AA.Data FROM Table1 AS AA WHERE AA.ID = BB.ID FOR XML PATH(''), TYPE).value('.','nvarchar(max)'), 1, 2, '') FROM Table1 AS BB 
GROUP BY ID,Data
ORDER BY ID;

How can I make Bootstrap 4 columns all the same height?

You can use the new Bootstrap cards:

_x000D_
_x000D_
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" integrity="sha384-rwoIResjU2yc3z8GV/NPeZWAv56rSmLldC3R/AZzGRnGxQQKnKkoFVhFQhNUwEyJ" crossorigin="anonymous">_x000D_
<script src="https://code.jquery.com/jquery-3.1.1.slim.min.js" integrity="sha384-A7FZj7v+d/sdmMqp/nOQwliLvUsJfDHW+k9Omg/a/EheAdgtzNs3hpfag6Ed950n" crossorigin="anonymous"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js" integrity="sha384-DztdAPBWPRXSA/3eYEEUWrWCy7G5KFbe8fFjk5JAIxUYHKkDx6Qin1DkWx51bBrb" crossorigin="anonymous"></script>_x000D_
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js" integrity="sha384-vBWWzlZJ8ea9aCX4pEW3rVHjgjt7zpkNpZk+02D9phzyeVkE+jo0ieGizqPLForn" crossorigin="anonymous"></script>_x000D_
_x000D_
<div class="card-group">_x000D_
  <div class="card">_x000D_
    <img class="card-img-top" src="..." alt="Card image cap">_x000D_
    <div class="card-block">_x000D_
      <h4 class="card-title">Card title</h4>_x000D_
      <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer.</p>_x000D_
    </div>_x000D_
    <div class="card-footer">_x000D_
      <small class="text-muted">Last updated 3 mins ago</small>_x000D_
    </div>_x000D_
  </div>_x000D_
  <div class="card">_x000D_
    <img class="card-img-top" src="..." alt="Card image cap">_x000D_
    <div class="card-block">_x000D_
      <h4 class="card-title">Card title</h4>_x000D_
      <p class="card-text">This card has supporting text below as a natural lead-in to additional content.</p>_x000D_
    </div>_x000D_
    <div class="card-footer">_x000D_
      <small class="text-muted">Last updated 3 mins ago</small>_x000D_
    </div>_x000D_
  </div>_x000D_
  <div class="card">_x000D_
    <img class="card-img-top" src="..." alt="Card image cap">_x000D_
    <div class="card-block">_x000D_
      <h4 class="card-title">Card title</h4>_x000D_
      <p class="card-text">This is a wider card with supporting text below as a natural lead-in to additional content. This card has even longer content than the first to show that equal height action.</p>_x000D_
    </div>_x000D_
    <div class="card-footer">_x000D_
      <small class="text-muted">Last updated 3 mins ago</small>_x000D_
    </div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Link: Click here

regards,

Twitter Bootstrap Form File Element Upload Button

No fancy shiz required:

HTML:

<form method="post" action="/api/admin/image" enctype="multipart/form-data">
    <input type="hidden" name="url" value="<%= boxes[i].url %>" />
    <input class="image-file-chosen" type="text" />
    <br />
    <input class="btn image-file-button" value="Choose Image" />
    <input class="image-file hide" type="file" name="image"/> <!-- Hidden -->
    <br />
    <br />
    <input class="btn" type="submit" name="image" value="Upload" />
    <br />
</form>

JS:

$('.image-file-button').each(function() {
      $(this).off('click').on('click', function() {
           $(this).siblings('.image-file').trigger('click');
      });
});
$('.image-file').each(function() {
      $(this).change(function () {
           $(this).siblings('.image-file-chosen').val(this.files[0].name);
      });
});

CAUTION: The three form elements in question MUST be siblings of each other (.image-file-chosen, .image-file-button, .image-file)

Warning: mysqli_query() expects parameter 1 to be mysqli, null given in

As mentioned in comments, this is a scoping issue. Specifically, $con is not in scope within your getPosts function.

You should pass your connection object in as a dependency, eg

function getPosts(mysqli $con) {
    // etc

I would also highly recommend halting execution if your connection fails or if errors occur. Something like this should suffice

mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT); // throw exceptions
$con=mysqli_connect("localhost","xxxx","xxxx","xxxxx");

getPosts($con);

Android: Storing username and password?

You should use the Android AccountManager. It's purpose-built for this scenario. It's a little bit cumbersome but one of the things it does is invalidate the local credentials if the SIM card changes, so if somebody swipes your phone and throws a new SIM in it, your credentials won't be compromised.

This also gives the user a quick and easy way to access (and potentially delete) the stored credentials for any account they have on the device, all from one place.

SampleSyncAdapter (like @Miguel mentioned) is an example that makes use of stored account credentials.

How to run .APK file on emulator

Start an Android Emulator (make sure that all supported APIs are included when you created the emulator, we needed to have the Google APIs for instance).

Then simply email yourself a link to the .apk file, and download it directly in the emulator, and click the downloaded file to install it.

VBA Date as integer

Date is not an Integer in VB(A), it is a Double.

You can get a Date's value by passing it to CDbl().

CDbl(Now())      ' 40877.8052662037 

From the documentation:

The 1900 Date System

In the 1900 date system, the first day that is supported is January 1, 1900. When you enter a date, the date is converted into a serial number that represents the number of elapsed days starting with 1 for January 1, 1900. For example, if you enter July 5, 1998, Excel converts the date to the serial number 35981.

So in the 1900 system, 40877.805... represents 40,876 days after January 1, 1900 (29 November 2011), and ~80.5% of one day (~19:19h). There is a setting for 1904-based system in Excel, numbers will be off when this is in use (that's a per-workbook setting).

To get the integer part, use

Int(CDbl(Now())) ' 40877

which would return a LongDouble with no decimal places (i.e. what Floor() would do in other languages).

Using CLng() or Round() would result in rounding, which will return a "day in the future" when called after 12:00 noon, so don't do that.

How do I get the last four characters from a string in C#?

I threw together some code modified from various sources that will get the results you want, and do a lot more besides. I've allowed for negative int values, int values that exceed the length of the string, and for end index being less than the start index. In that last case, the method returns a reverse-order substring. There are plenty of comments, but let me know if anything is unclear or just crazy. I was playing around with this to see what all I might use it for.

    /// <summary>
    /// Returns characters slices from string between two indexes.
    /// 
    /// If start or end are negative, their indexes will be calculated counting 
    /// back from the end of the source string. 
    /// If the end param is less than the start param, the Slice will return a 
    /// substring in reverse order.
    /// 
    /// <param name="source">String the extension method will operate upon.</param>
    /// <param name="startIndex">Starting index, may be negative.</param>
    /// <param name="endIndex">Ending index, may be negative).</param>
    /// </summary>
    public static string Slice(this string source, int startIndex, int endIndex = int.MaxValue)
    {
        // If startIndex or endIndex exceeds the length of the string they will be set 
        // to zero if negative, or source.Length if positive.
        if (source.ExceedsLength(startIndex)) startIndex = startIndex < 0 ? 0 : source.Length;
        if (source.ExceedsLength(endIndex)) endIndex = endIndex < 0 ? 0 : source.Length;

        // Negative values count back from the end of the source string.
        if (startIndex < 0) startIndex = source.Length + startIndex;
        if (endIndex < 0) endIndex = source.Length + endIndex;         

        // Calculate length of characters to slice from string.
        int length = Math.Abs(endIndex - startIndex);
        // If the endIndex is less than the startIndex, return a reversed substring.
        if (endIndex < startIndex) return source.Substring(endIndex, length).Reverse();

        return source.Substring(startIndex, length);
    }

    /// <summary>
    /// Reverses character order in a string.
    /// </summary>
    /// <param name="source"></param>
    /// <returns>string</returns>
    public static string Reverse(this string source)
    {
        char[] charArray = source.ToCharArray();
        Array.Reverse(charArray);
        return new string(charArray);
    }

    /// <summary>
    /// Verifies that the index is within the range of the string source.
    /// </summary>
    /// <param name="source"></param>
    /// <param name="index"></param>
    /// <returns>bool</returns>
    public static bool ExceedsLength(this string source, int index)
    {
        return Math.Abs(index) > source.Length ? true : false;
    }

So if you have a string like "This is an extension method", here are some examples and results to expect.

var s = "This is an extension method";
// If you want to slice off end characters, just supply a negative startIndex value
// but no endIndex value (or an endIndex value >= to the source string length).
Console.WriteLine(s.Slice(-5));
// Returns "ethod".
Console.WriteLine(s.Slice(-5, 10));
// Results in a startIndex of 22 (counting 5 back from the end).
// Since that is greater than the endIndex of 10, the result is reversed.
// Returns "m noisnetxe"
Console.WriteLine(s.Slice(2, 15));
// Returns "is is an exte"

Hopefully this version is helpful to someone. It operates just like normal if you don't use any negative numbers, and provides defaults for out of range params.

What is a plain English explanation of "Big O" notation?

It represents the speed of an algorithm in the long run.

To take a literal analogy, you don't care how fast a runner can sprint a 100m dash, or even a 5k run. You care more about marathoners, and preferably ultra marathoners (beyond which the analogy to running breaks down and you have to revert to the metaphorical meaning of "the long run").

You can safely stop reading here.

I'm adding this answer because I'm surprised how mathematical and technical the rest of the answers are. The notion of the "long run" in first sentence is related to the arbitrarily time-consuming computational tasks. Unlike running, which is limited by human capacity, computational tasks can take even more than millions of years for certain algorithms to complete.

What about all those mathematical logarithms and polynomials? It turns out that algorithms are intrinsically related to these mathematical terms. If you are measuring the heights of all the kids on the block, it will take you as much time as there are kids. This is intrinsically related to the notion of n^1 or just n where n is nothing more than the number of kids on the block. In the ultra-marathon case, you are measuring the heights of all the kids in your city, but you then have to ignore travel times and assume they are all available to you in a line (otherwise we jump ahead of the current explanation).

Suppose then you are trying to arrange the list that you made of of kids heights in order of shortest height to longest height. If it is just the kids in your neighborhood you might just eyeball it and come up with the ordered list. This is the "sprint" analogy, and we truly don't care about sprints in computer science because why use a computer when you can eyeball something?

But if you were arranging the list of the heights of all kids in your city, or better yet, your country, then you will find that how you do it is intrinsically tied to the mathematical log and n^2. Going through your list to find the shortest kid, writing his name in a separate notebook, and crossing it out from the original notebook is intrinsically tied to the mathematical n^2. If you think of arranging half your notebook, then the other half, and then combining the results, you will arrive at a method that is intrinsically tied to the logarithm.

Finally, suppose you first had to go to the store to buy a measuring tape. This is an example of an effort that is of consequence in short sprints, such as measuring the kids on the block, but when you are measuring all the kids in the city you can safely ignore this cost. This is the intrinsic connection to the mathematical dropping of say lower order polynomial terms.

I hope I have explained that the big-O notation is merely about the long run, that the mathematics is inherently connected to ways of computation, and that the dropping of mathematical terms and other simplifications are connected to the long run in a rather common sense way.

Once you realize this, you'll find the big-O is really super-easy because all the hard high school math just drops out easily. The only difficult part is analyzing an algorithm to identify the mathematical terms, but with some practice you can start dropping terms during the analysis itself and safely ignore chunks of the algorithm to focus only on the part that is relevant to the big-O. I. e. you should be able to eyeball most situations.

Happy big-O-ing, it was my favorite thing about Computer Science -- finding that something was way easier than I thought, and then being able to show off at Google interviews when the uninitiated would be intimidated, lol.

plot different color for different categorical levels using matplotlib

Here's a succinct and generic solution to use a seaborn color palette.

First find a color palette you like and optionally visualize it:

sns.palplot(sns.color_palette("Set2", 8))

Then you can use it with matplotlib doing this:

# Unique category labels: 'D', 'F', 'G', ...
color_labels = df['color'].unique()

# List of RGB triplets
rgb_values = sns.color_palette("Set2", 8)

# Map label to RGB
color_map = dict(zip(color_labels, rgb_values))

# Finally use the mapped values
plt.scatter(df['carat'], df['price'], c=df['color'].map(color_map))

Pure Javascript listen to input value change

Another approach in 2020 could be using document.querySelector():

const myInput = document.querySelector('input[name="exampleInput"]');

myInput.addEventListener("change", (e) => {
  // here we do something
});

how to change text box value with jQuery?

Simple and easy :

 $('#email').val(YourNewValue);

TypeError: Invalid dimensions for image data when plotting array with imshow()

There is a (somewhat) related question on StackOverflow:

Here the problem was that an array of shape (nx,ny,1) is still considered a 3D array, and must be squeezed or sliced into a 2D array.

More generally, the reason for the Exception

TypeError: Invalid dimensions for image data

is shown here: matplotlib.pyplot.imshow() needs a 2D array, or a 3D array with the third dimension being of shape 3 or 4!

You can easily check this with (these checks are done by imshow, this function is only meant to give a more specific message in case it's not a valid input):

from __future__ import print_function
import numpy as np

def valid_imshow_data(data):
    data = np.asarray(data)
    if data.ndim == 2:
        return True
    elif data.ndim == 3:
        if 3 <= data.shape[2] <= 4:
            return True
        else:
            print('The "data" has 3 dimensions but the last dimension '
                  'must have a length of 3 (RGB) or 4 (RGBA), not "{}".'
                  ''.format(data.shape[2]))
            return False
    else:
        print('To visualize an image the data must be 2 dimensional or '
              '3 dimensional, not "{}".'
              ''.format(data.ndim))
        return False

In your case:

>>> new_SN_map = np.array([1,2,3])
>>> valid_imshow_data(new_SN_map)
To visualize an image the data must be 2 dimensional or 3 dimensional, not "1".
False

The np.asarray is what is done internally by matplotlib.pyplot.imshow so it's generally best you do it too. If you have a numpy array it's obsolete but if not (for example a list) it's necessary.


In your specific case you got a 1D array, so you need to add a dimension with np.expand_dims()

import matplotlib.pyplot as plt
a = np.array([1,2,3,4,5])
a = np.expand_dims(a, axis=0)  # or axis=1
plt.imshow(a)
plt.show()

enter image description here

or just use something that accepts 1D arrays like plot:

a = np.array([1,2,3,4,5])
plt.plot(a)
plt.show()

enter image description here

Can I append an array to 'formdata' in javascript?

Simply you can do like this:

var formData = new FormData();
formData.append('array[key1]', this.array.key1);
formData.append('array[key2]', this.array.key2);

What is the difference between find(), findOrFail(), first(), firstOrFail(), get(), list(), toArray()

  1. find($id) takes an id and returns a single model. If no matching model exist, it returns null.

  2. findOrFail($id) takes an id and returns a single model. If no matching model exist, it throws an error1.

  3. first() returns the first record found in the database. If no matching model exist, it returns null.

  4. firstOrFail() returns the first record found in the database. If no matching model exist, it throws an error1.

  5. get() returns a collection of models matching the query.

  6. pluck($column) returns a collection of just the values in the given column. In previous versions of Laravel this method was called lists.

  7. toArray() converts the model/collection into a simple PHP array.


Note: a collection is a beefed up array. It functions similarly to an array, but has a lot of added functionality, as you can see in the docs.

Unfortunately, PHP doesn't let you use a collection object everywhere you can use an array. For example, using a collection in a foreach loop is ok, put passing it to array_map is not. Similarly, if you type-hint an argument as array, PHP won't let you pass it a collection. Starting in PHP 7.1, there is the iterable typehint, which can be used to accept both arrays and collections.

If you ever want to get a plain array from a collection, call its all() method.


1 The error thrown by the findOrFail and firstOrFail methods is a ModelNotFoundException. If you don't catch this exception yourself, Laravel will respond with a 404, which is what you want most of the time.

Check time difference in Javascript

var moment = require("moment");
var momentDurationFormatSetup = require("moment-duration-format")

var now  = "2015-07-16T16:33:39.113Z";
var then = "2015-06-16T22:33:39.113Z";

var ms = moment(now,"YYYY-MM-DD'T'HH:mm:ss:SSSZ").diff(moment(then,"YYYY-MM-DD'T'HH:mm:ss:SSSZ"));
var d = moment.duration(ms);
var s = d.format("dd:hh:mm:ss");
console.log(s);

Python 'list indices must be integers, not tuple"

To create list of lists, you need to separate them with commas, like this

coin_args = [
    ["pennies", '2.5', '50.0', '.01'],
    ["nickles", '5.0', '40.0', '.05'],
    ["dimes", '2.268', '50.0', '.1'],
    ["quarters", '5.67', '40.0', '.25']
]

Laravel Carbon subtract days from current date

From Laravel 5.6 you can use whereDate:

$users = Users::where('status_id', 'active')
       ->whereDate( 'created_at', '>', now()->subDays(30))
       ->get();

You also have whereMonth / whereDay / whereYear / whereTime

Increase max execution time for php

This is old question, but if somebody finds it today chances are php will be run via php-fpm and mod_fastcgi. In that case nothing here will help with extending execution time because Apache will terminate connection to a process which does not output anything for 30 seconds. Only way to extend it is to change -idle-timeout in apache (module/site/vhost) config.

FastCgiExternalServer /usr/lib/cgi-bin/php7-fcgi -socket /run/php/php7.0-fpm.sock -idle-timeout 900 -pass-header Authorization

More details - Increase PHP-FPM idle timeout setting

CORS - How do 'preflight' an httprequest?

During the preflight request, you should see the following two headers: Access-Control-Request-Method and Access-Control-Request-Headers. These request headers are asking the server for permissions to make the actual request. Your preflight response needs to acknowledge these headers in order for the actual request to work.

For example, suppose the browser makes a request with the following headers:

Origin: http://yourdomain.com
Access-Control-Request-Method: POST
Access-Control-Request-Headers: X-Custom-Header

Your server should then respond with the following headers:

Access-Control-Allow-Origin: http://yourdomain.com
Access-Control-Allow-Methods: GET, POST
Access-Control-Allow-Headers: X-Custom-Header

Pay special attention to the Access-Control-Allow-Headers response header. The value of this header should be the same headers in the Access-Control-Request-Headers request header, and it can not be '*'.

Once you send this response to the preflight request, the browser will make the actual request. You can learn more about CORS here: http://www.html5rocks.com/en/tutorials/cors/

Eclipse Workspaces: What for and why?

Basically the scope of workspace(s) is divided in two points.

First point (and primary) is the eclipse it self and is related with the settings and metadata configurations (plugin ctr). Each time you create a project, eclipse collects all the configurations and stores them on that workspace and if somehow in the same workspace a conflicting project is present you might loose some functionality or even stability of eclipse it self.

And second (secondary) the point of development strategy one can adopt. Once the primary scope is met (and mastered) and there's need for further adjustments regarding project relations (as libraries, perspectives ctr) then initiate separate workspace(s) could be appropriate based on development habits or possible language/frameworks "behaviors". DLTK for examples is a beast that should be contained in a separate cage. Lots of complains at forums for it stopped working (properly or not at all) and suggested solution was to clean the settings of the equivalent plugin from the current workspace.

Personally, I found myself lean more to language distinction when it comes to separate workspaces which is relevant to known issues that comes with the current state of the plugins are used. Preferably I keep them in the minimum numbers as this is leads to less frustration when the projects are become... plenty and version control is not the only version you keep your projects. Finally, loading speed and performance is an issue that might come up if lots of (unnecessary) plugins are loaded due to presents of irrelevant projects. Bottom line; there is no one solution to every one, no master blue print that solves the issue. It's something that grows with experience, Less is more though!

What are the alternatives now that the Google web search API has been deprecated?

Google Custom Search (as advocated in the top rated answers) works well, but is very expensive, compared to its competitors (below) or compared to other Google API's. It has a small free tier (100 queries/day) and a very high price of $5 per 1000 query.

They offer the option to upgrade to Site Search, which has slightly better prices, but that is meant for searching one site (your own), so it is really something quite different - not an upgrade.

The main alternatives seem to be:

Bing Search API
https://datamarket.azure.com/dataset/5BA839F1-12CE-4CCE-BF57-A49D98D29A44
Which has a free tier of 5000q/month, and prices starting at 5 query per penny, and no hard limit.

UPDATE: At the end of 2016 this API was shutdown in favour of its Azure counterpart "Cognitive Services Bing Search API":
https://azure.microsoft.com/en-us/services/cognitive-services/search/

See here for a pricing chart, which starts at US$3/m for 1,000 transactions. Unless I'm missing something it is quite expensive.

Yahoo BOSS Search API
UPDATE: Was discontinued on March 31, 2016. http://developer.yahoo.com/boss/search/
With prices starting at about 12 queries/penny for whole web searches.

And some I haven't heard of before:

http://www.gigablast.com/searchfeed.html

http://www.faroo.com/hp/api/api.html

http://www.commoncrawl.org/

http://www.entireweb.com/search_api/implementation/
[discontinued - as pointed out below]

There is a bit of discussion of some of these on this SO post.
[got closed for being off-topic and is now gone]

How to encrypt and decrypt file in Android?

Use a CipherOutputStream or CipherInputStream with a Cipher and your FileInputStream / FileOutputStream.

I would suggest something like Cipher.getInstance("AES/CBC/PKCS5Padding") for creating the Cipher class. CBC mode is secure and does not have the vulnerabilities of ECB mode for non-random plaintexts. It should be present in any generic cryptographic library, ensuring high compatibility.

Don't forget to use a Initialization Vector (IV) generated by a secure random generator if you want to encrypt multiple files with the same key. You can prefix the plain IV at the start of the ciphertext. It is always exactly one block (16 bytes) in size.

If you want to use a password, please make sure you do use a good key derivation mechanism (look up password based encryption or password based key derivation). PBKDF2 is the most commonly used Password Based Key Derivation scheme and it is present in most Java runtimes, including Android. Note that SHA-1 is a bit outdated hash function, but it should be fine in PBKDF2, and does currently present the most compatible option.

Always specify the character encoding when encoding/decoding strings, or you'll be in trouble when the platform encoding differs from the previous one. In other words, don't use String.getBytes() but use String.getBytes(StandardCharsets.UTF_8).

To make it more secure, please add cryptographic integrity and authenticity by adding a secure checksum (MAC or HMAC) over the ciphertext and IV, preferably using a different key. Without an authentication tag the ciphertext may be changed in such a way that the change cannot be detected.

Be warned that CipherInputStream may not report BadPaddingException, this includes BadPaddingException generated for authenticated ciphers such as GCM. This would make the streams incompatible and insecure for these kind of authenticated ciphers.

Android: resizing imageview in XML

Please try this one works for me:

<ImageView android:id="@+id/image_view"     
  android:layout_width="wrap_content"  
  android:layout_height="wrap_content"  
  android:adjustViewBounds="true"  
  android:maxWidth="60dp" 
  android:layout_gravity="center" 
  android:maxHeight="60dp"  
  android:scaleType="fitCenter"  
  android:src="@drawable/icon"  
  /> 

Difference between Visibility.Collapsed and Visibility.Hidden

Even though a bit old thread, for those who still looking for the differences:

Aside from layout (space) taken in Hidden and not taken in Collapsed, there is another difference.

If we have custom controls inside this 'Collapsed' main control, the next time we set it to Visible, it will "load" all custom controls. It will not pre-load when window is started.

As for 'Hidden', it will load all custom controls + main control which we set as hidden when the "window" is started.

100% width table overflowing div container

update your CSS to the following: this should fix

.page {
    width: 280px;
    border:solid 1px blue;
    overflow-x: auto;
}

Looping through all the properties of object php

For testing purposes I use the following:

//return assoc array when called from outside the class it will only contain public properties and values 
var_dump(get_object_vars($obj)); 

Make a Bash alias that takes a parameter?

Here's are three examples of functions I have in my ~/.bashrc, that are essentially aliases that accept a parameter:

#Utility required by all below functions.
#https://stackoverflow.com/questions/369758/how-to-trim-whitespace-from-bash-variable#comment21953456_3232433
alias trim="sed -e 's/^[[:space:]]*//g' -e 's/[[:space:]]*\$//g'"

.

:<<COMMENT
    Alias function for recursive deletion, with are-you-sure prompt.

    Example:
        srf /home/myusername/django_files/rest_tutorial/rest_venv/

    Parameter is required, and must be at least one non-whitespace character.

    Short description: Stored in SRF_DESC

    With the following setting, this is *not* added to the history:
        export HISTIGNORE="*rm -r*:srf *"
    - https://superuser.com/questions/232885/can-you-share-wisdom-on-using-histignore-in-bash

    See:
    - y/n prompt: https://stackoverflow.com/a/3232082/2736496
    - Alias w/param: https://stackoverflow.com/a/7131683/2736496
COMMENT
#SRF_DESC: For "aliaf" command (with an 'f'). Must end with a newline.
SRF_DESC="srf [path]: Recursive deletion, with y/n prompt\n"
srf()  {
    #Exit if no parameter is provided (if it's the empty string)
        param=$(echo "$1" | trim)
        echo "$param"
        if [ -z "$param" ]  #http://tldp.org/LDP/abs/html/comparison-ops.html
        then
          echo "Required parameter missing. Cancelled"; return
        fi

    #Actual line-breaks required in order to expand the variable.
    #- https://stackoverflow.com/a/4296147/2736496
    read -r -p "About to
    sudo rm -rf \"$param\"
Are you sure? [y/N] " response
    response=${response,,}    # tolower
    if [[ $response =~ ^(yes|y)$ ]]
    then
        sudo rm -rf "$param"
    else
        echo "Cancelled."
    fi
}

.

:<<COMMENT
    Delete item from history based on its line number. No prompt.

    Short description: Stored in HX_DESC

    Examples
        hx 112
        hx 3

    See:
    - https://unix.stackexchange.com/questions/57924/how-to-delete-commands-in-history-matching-a-given-string
COMMENT
#HX_DESC: For "aliaf" command (with an 'f'). Must end with a newline.
HX_DESC="hx [linenum]: Delete history item at line number\n"
hx()  {
    history -d "$1"
}

.

:<<COMMENT
    Deletes all lines from the history that match a search string, with a
    prompt. The history file is then reloaded into memory.

    Short description: Stored in HXF_DESC

    Examples
        hxf "rm -rf"
        hxf ^source

    Parameter is required, and must be at least one non-whitespace character.

    With the following setting, this is *not* added to the history:
        export HISTIGNORE="*hxf *"
    - https://superuser.com/questions/232885/can-you-share-wisdom-on-using-histignore-in-bash

    See:
    - https://unix.stackexchange.com/questions/57924/how-to-delete-commands-in-history-matching-a-given-string
COMMENT
#HXF_DESC: For "aliaf" command (with an 'f'). Must end with a newline.
HXF_DESC="hxf [searchterm]: Delete all history items matching search term, with y/n prompt\n"
hxf()  {
    #Exit if no parameter is provided (if it's the empty string)
        param=$(echo "$1" | trim)
        echo "$param"
        if [ -z "$param" ]  #http://tldp.org/LDP/abs/html/comparison-ops.html
        then
          echo "Required parameter missing. Cancelled"; return
        fi

    read -r -p "About to delete all items from history that match \"$param\". Are you sure? [y/N] " response
    response=${response,,}    # tolower
    if [[ $response =~ ^(yes|y)$ ]]
    then
        #Delete all matched items from the file, and duplicate it to a temp
        #location.
        grep -v "$param" "$HISTFILE" > /tmp/history

        #Clear all items in the current sessions history (in memory). This
        #empties out $HISTFILE.
        history -c

        #Overwrite the actual history file with the temp one.
        mv /tmp/history "$HISTFILE"

        #Now reload it.
        history -r "$HISTFILE"     #Alternative: exec bash
    else
        echo "Cancelled."
    fi
}

References:

How can I ask the Selenium-WebDriver to wait for few seconds in Java?

Implicit Wait: During Implicit wait if the Web Driver cannot find it immediately because of its availability, the WebDriver will wait for mentioned time and it will not try to find the element again during the specified time period. Once the specified time is over, it will try to search the element once again the last time before throwing exception. The default setting is zero. Once we set a time, the Web Driver waits for the period of the WebDriver object instance.

Explicit Wait: There can be instance when a particular element takes more than a minute to load. In that case you definitely not like to set a huge time to Implicit wait, as if you do this your browser will going to wait for the same time for every element. To avoid that situation you can simply put a separate time on the required element only. By following this your browser implicit wait time would be short for every element and it would be large for specific element.

Android: Scale a Drawable or background image?

Kotlin:

If you needed to draw a bitmap in a View, scaled to FIT.

You can do the proper calculations to set bm the height equal to the container and adjust width, in the case bm width to height ratio is less than container width to height ratio, or the inverse in the opposite scenario.

Images:

Example Image 1

Example Image 2

// binding.fragPhotoEditDrawCont is the RelativeLayout where is your view
// bm is the Bitmap
val ch = binding.fragPhotoEditDrawCont.height
val cw = binding.fragPhotoEditDrawCont.width
val bh = bm.height
val bw = bm.width
val rc = cw.toFloat() / ch.toFloat()
val rb = bw.toFloat() / bh.toFloat()

if (rb < rc) {
    // Bitmap Width to Height ratio is less than Container ratio
    // Means, bitmap should pin top and bottom, and have some space on sides.
    //              _____          ___
    // container = |_____|   bm = |___| 
    val bmHeight = ch - 4 //4 for container border
    val bmWidth = rb * bmHeight //new width is bm_ratio * bm_height
    binding.fragPhotoEditDraw.layoutParams = RelativeLayout.LayoutParams(bmWidth.toInt(), bmHeight)
}
else {
    val bmWidth = cw - 4 //4 for container border
    val bmHeight = 1f/rb * cw
    binding.fragPhotoEditDraw.layoutParams = RelativeLayout.LayoutParams(bmWidth, bmHeight.toInt())
}

.htaccess redirect http to https

This makes sure that redirects work for all combinations of intransparent proxies.

This includes the case client <http> proxy <https> webserver.

# behind proxy
RewriteCond %{HTTP:X-FORWARDED-PROTO} ^http$
RewriteRule (.*) https://%{HTTP_HOST}/$1 [R=301,L]

# plain
RewriteCond %{HTTP:X-FORWARDED-PROTO} ^$
RewriteCond %{REQUEST_SCHEME} ^http$ [NC,OR]
RewriteCond %{HTTPS} off
RewriteRule (.*) https://%{HTTP_HOST}/$1 [R=301,L]

Remove special symbols and extra spaces and replace with underscore using the replace method

It was not asked precisely to remove accent (only special characters), but I needed to.

The solutions givens here works but they don’t remove accent: é, è, etc.

So, before doing epascarello’s solution, you can also do:

_x000D_
_x000D_
var newString = "développeur & intégrateur";_x000D_
_x000D_
newString = replaceAccents(newString);_x000D_
newString = newString.replace(/[^A-Z0-9]+/ig, "_");_x000D_
alert(newString);_x000D_
_x000D_
/**_x000D_
 * Replaces all accented chars with regular ones_x000D_
 */_x000D_
function replaceAccents(str) {_x000D_
  // Verifies if the String has accents and replace them_x000D_
  if (str.search(/[\xC0-\xFF]/g) > -1) {_x000D_
    str = str_x000D_
      .replace(/[\xC0-\xC5]/g, "A")_x000D_
      .replace(/[\xC6]/g, "AE")_x000D_
      .replace(/[\xC7]/g, "C")_x000D_
      .replace(/[\xC8-\xCB]/g, "E")_x000D_
      .replace(/[\xCC-\xCF]/g, "I")_x000D_
      .replace(/[\xD0]/g, "D")_x000D_
      .replace(/[\xD1]/g, "N")_x000D_
      .replace(/[\xD2-\xD6\xD8]/g, "O")_x000D_
      .replace(/[\xD9-\xDC]/g, "U")_x000D_
      .replace(/[\xDD]/g, "Y")_x000D_
      .replace(/[\xDE]/g, "P")_x000D_
      .replace(/[\xE0-\xE5]/g, "a")_x000D_
      .replace(/[\xE6]/g, "ae")_x000D_
      .replace(/[\xE7]/g, "c")_x000D_
      .replace(/[\xE8-\xEB]/g, "e")_x000D_
      .replace(/[\xEC-\xEF]/g, "i")_x000D_
      .replace(/[\xF1]/g, "n")_x000D_
      .replace(/[\xF2-\xF6\xF8]/g, "o")_x000D_
      .replace(/[\xF9-\xFC]/g, "u")_x000D_
      .replace(/[\xFE]/g, "p")_x000D_
      .replace(/[\xFD\xFF]/g, "y");_x000D_
  }_x000D_
_x000D_
  return str;_x000D_
}
_x000D_
_x000D_
_x000D_

Source: https://gist.github.com/jonlabelle/5375315

sqlite3.OperationalError: unable to open database file

I faced exactly same issue. Here is my setting which worked.

'ENGINE': 'django.db.backends.sqlite3', 
'NAME': '/home/path/to/your/db/data.sqlite3'

Other setting in case of sqlite3 will be same/default.
And you need to create data.sqlite3.

Creating a JSON Array in node js

You don't have JSON. You have a JavaScript data structure consisting of objects, an array, some strings and some numbers.

Use JSON.stringify(object) to turn it into (a string of) JSON text.

How to create tar.gz archive file in Windows?

tar.gz file is just a tar file that's been gzipped. Both tar and gzip are available for windows.

If you like GUIs (Graphical user interface), 7zip can pack with both tar and gzip.

How to set URL query params in Vue with Vue-Router

For adding multiple query params, this is what worked for me (from here https://forum.vuejs.org/t/vue-router-programmatically-append-to-querystring/3655/5).

an answer above was close … though with Object.assign it will mutate this.$route.query which is not what you want to do … make sure the first argument is {} when doing Object.assign

this.$router.push({ query: Object.assign({}, this.$route.query, { newKey: 'newValue' }) });

HTML 5 Favicon - Support?

No, not all browsers support the sizes attribute:

Note that some platforms define specific sizes:

Emulate/Simulate iOS in Linux

You might want to try screenfly. It worked great for me.

$lookup on ObjectId's in an array

You can also use the pipeline stage to perform checks on a sub-docunment array

Here's the example using python (sorry I'm snake people).

db.products.aggregate([
  { '$lookup': {
      'from': 'products',
      'let': { 'pid': '$products' },
      'pipeline': [
        { '$match': { '$expr': { '$in': ['$_id', '$$pid'] } } }
        // Add additional stages here 
      ],
      'as':'productObjects'
  }
])

The catch here is to match all objects in the ObjectId array (foreign _id that is in local field/prop products).

You can also clean up or project the foreign records with additional stages, as indicated by the comment above.

Clip/Crop background-image with CSS

may be you can write like this:

#graphic { 
 background-image: url(image.jpg); 
 background-position: 0 -50px; 
 width: 200px; 
 height: 100px;
}

Should I use "camel case" or underscores in python?

for everything related to Python's style guide: i'd recommend you read PEP8.

To answer your question:

Function names should be lowercase, with words separated by underscores as necessary to improve readability.

Get content uri from file path in android

The accepted solution is probably the best bet for your purposes, but to actually answer the question in the subject line:

In my app, I have to get the path from URIs and get the URI from paths. The former:

/**
 * Gets the corresponding path to a file from the given content:// URI
 * @param selectedVideoUri The content:// URI to find the file path from
 * @param contentResolver The content resolver to use to perform the query.
 * @return the file path as a string
 */
private String getFilePathFromContentUri(Uri selectedVideoUri,
        ContentResolver contentResolver) {
    String filePath;
    String[] filePathColumn = {MediaColumns.DATA};

    Cursor cursor = contentResolver.query(selectedVideoUri, filePathColumn, null, null, null);
    cursor.moveToFirst();

    int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
    filePath = cursor.getString(columnIndex);
    cursor.close();
    return filePath;
}

The latter (which I do for videos, but can also be used for Audio or Files or other types of stored content by substituting MediaStore.Audio (etc) for MediaStore.Video):

/**
 * Gets the MediaStore video ID of a given file on external storage
 * @param filePath The path (on external storage) of the file to resolve the ID of
 * @param contentResolver The content resolver to use to perform the query.
 * @return the video ID as a long
 */
private long getVideoIdFromFilePath(String filePath,
        ContentResolver contentResolver) {


    long videoId;
    Log.d(TAG,"Loading file " + filePath);

            // This returns us content://media/external/videos/media (or something like that)
            // I pass in "external" because that's the MediaStore's name for the external
            // storage on my device (the other possibility is "internal")
    Uri videosUri = MediaStore.Video.Media.getContentUri("external");

    Log.d(TAG,"videosUri = " + videosUri.toString());

    String[] projection = {MediaStore.Video.VideoColumns._ID};

    // TODO This will break if we have no matching item in the MediaStore.
    Cursor cursor = contentResolver.query(videosUri, projection, MediaStore.Video.VideoColumns.DATA + " LIKE ?", new String[] { filePath }, null);
    cursor.moveToFirst();

    int columnIndex = cursor.getColumnIndex(projection[0]);
    videoId = cursor.getLong(columnIndex);

    Log.d(TAG,"Video ID is " + videoId);
    cursor.close();
    return videoId;
}

Basically, the DATA column of MediaStore (or whichever sub-section of it you're querying) stores the file path, so you use that info to look it up.

IntelliJ can't recognize JavaFX 11 with OpenJDK 11

Quick summary, you can do either:

  1. Include the JavaFX modules via --module-path and --add-modules like in José's answer.

    OR

  2. Once you have JavaFX libraries added to your project (either manually or via maven/gradle import), add the module-info.java file similar to the one specified in this answer. (Note that this solution makes your app modular, so if you use other libraries, you will also need to add statements to require their modules inside the module-info.java file).


This answer is a supplement to Jose's answer.

The situation is this:

  1. You are using a recent Java version, e.g. 13.
  2. You have a JavaFX application as a Maven project.
  3. In your Maven project you have the JavaFX plugin configured and JavaFX dependencies setup as per Jose's answer.
  4. You go to the source code of your main class which extends Application, you right-click on it and try to run it.
  5. You get an IllegalAccessError involving an "unnamed module" when trying to launch the app.

Excerpt for a stack trace generating an IllegalAccessError when trying to run a JavaFX app from Intellij Idea:

Exception in Application start method
java.lang.reflect.InvocationTargetException
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:567)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:464)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:363)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:567)
    at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1051)
Caused by: java.lang.RuntimeException: Exception in Application start method
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:900)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:195)
    at java.base/java.lang.Thread.run(Thread.java:830)
Caused by: java.lang.IllegalAccessError: class com.sun.javafx.fxml.FXMLLoaderHelper (in unnamed module @0x45069d0e) cannot access class com.sun.javafx.util.Utils (in module javafx.graphics) because module javafx.graphics does not export com.sun.javafx.util to unnamed module @0x45069d0e
    at com.sun.javafx.fxml.FXMLLoaderHelper.<clinit>(FXMLLoaderHelper.java:38)
    at javafx.fxml.FXMLLoader.<clinit>(FXMLLoader.java:2056)
    at org.jewelsea.demo.javafx.springboot.Main.start(Main.java:13)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:846)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:455)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:428)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:427)
    at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
Exception running application org.jewelsea.demo.javafx.springboot.Main

OK, now you are kind of stuck and have no clue what is going on.

What has actually happened is this:

  1. Maven has successfully downloaded the JavaFX dependencies for your application, so you don't need to separately download the dependencies or install a JavaFX SDK or module distribution or anything like that.
  2. Idea has successfully imported the modules as dependencies to your project, so everything compiles OK and all of the code completion and everything works fine.

So it seems everything should be OK. BUT, when you run your application, the code in the JavaFX modules is failing when trying to use reflection to instantiate instances of your application class (when you invoke launch) and your FXML controller classes (when you load FXML). Without some help, this use of reflection can fail in some cases, generating the obscure IllegalAccessError. This is due to a Java module system security feature which does not allow code from other modules to use reflection on your classes unless you explicitly allow it (and the JavaFX application launcher and FXMLLoader both require reflection in their current implementation in order for them to function correctly).

This is where some of the other answers to this question, which reference module-info.java, come into the picture.

So let's take a crash course in Java modules:

The key part is this:

4.9. Opens

If we need to allow reflection of private types, but we don't want all of our code exposed, we can use the opens directive to expose specific packages.

But remember, this will open the package up to the entire world, so make sure that is what you want:

module my.module { opens com.my.package; }

So, perhaps you don't want to open your package to the entire world, then you can do:

4.10. Opens … To

Okay, so reflection is great sometimes, but we still want as much security as we can get from encapsulation. We can selectively open our packages to a pre-approved list of modules, in this case, using the opens…to directive:

module my.module { opens com.my.package to moduleOne, moduleTwo, etc.; }

So, you end up creating a src/main/java/module-info.java class which looks like this:

module org.jewelsea.demo.javafx.springboot {
    requires javafx.fxml;
    requires javafx.controls;
    requires javafx.graphics;
    opens org.jewelsea.demo.javafx.springboot to javafx.graphics,javafx.fxml;
}

Where, org.jewelsea.demo.javafx.springboot is the name of the package which contains the JavaFX Application class and JavaFX Controller classes (replace this with the appropriate package name for your application). This tells the Java runtime that it is OK for classes in the javafx.graphics and javafx.fxml to invoke reflection on the classes in your org.jewelsea.demo.javafx.springboot package. Once this is done, and the application is compiled and re-run things will work fine and the IllegalAccessError generated by JavaFX's use of reflection will no longer occur.

But what if you don't want to create a module-info.java file

If instead of using the the Run button in the top toolbar of IDE to run your application class directly, you instead:

  1. Went to the Maven window in the side of the IDE.
  2. Chose the javafx maven plugin target javafx.run.
  3. Right-clicked on that and chose either Run Maven Build or Debug....

Then the app will run without the module-info.java file. I guess this is because the maven plugin is smart enough to dynamically include some kind of settings which allows the app to be reflected on by the JavaFX classes even without a module-info.java file, though I don't know how this is accomplished.

To get that setting transferred to the Run button in the top toolbar, right-click on the javafx.run Maven target and choose the option to Create Run/Debug Configuration for the target. Then you can just choose Run from the top toolbar to execute the Maven target.

fork() and wait() with two child processes

It looks to me as though the basic problem is that you have one wait() call rather than a loop that waits until there are no more children. You also only wait if the last fork() is successful rather than if at least one fork() is successful.

You should only use _exit() if you don't want normal cleanup operations - such as flushing open file streams including stdout. There are occasions to use _exit(); this is not one of them. (In this example, you could also, of course, simply have the children return instead of calling exit() directly because returning from main() is equivalent to exiting with the returned status. However, most often you would be doing the forking and so on in a function other than main(), and then exit() is often appropriate.)


Hacked, simplified version of your code that gives the diagnostics I'd want. Note that your for loop skipped the first element of the array (mine doesn't).

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>

int main(void)
{
    pid_t child_pid, wpid;
    int status = 0;
    int i;
    int a[3] = {1, 2, 1};

    printf("parent_pid = %d\n", getpid());
    for (i = 0; i < 3; i++)
    {
        printf("i = %d\n", i);
        if ((child_pid = fork()) == 0)
        {
            printf("In child process (pid = %d)\n", getpid());
            if (a[i] < 2)
            {
                printf("Should be accept\n");
                exit(1);
            }
            else
            {
                printf("Should be reject\n");
                exit(0);
            }
            /*NOTREACHED*/
        }
    }

    while ((wpid = wait(&status)) > 0)
    {
        printf("Exit status of %d was %d (%s)\n", (int)wpid, status,
               (status > 0) ? "accept" : "reject");
    }
    return 0;
}

Example output (MacOS X 10.6.3):

parent_pid = 15820
i = 0
i = 1
In child process (pid = 15821)
Should be accept
i = 2
In child process (pid = 15822)
Should be reject
In child process (pid = 15823)
Should be accept
Exit status of 15823 was 256 (accept)
Exit status of 15822 was 0 (reject)
Exit status of 15821 was 256 (accept)

Is it possible to cast a Stream in Java 8?

This looks a little ugly. Is it possible to cast an entire stream to a different type? Like cast Stream<Object> to a Stream<Client>?

No that wouldn't be possible. This is not new in Java 8. This is specific to generics. A List<Object> is not a super type of List<String>, so you can't just cast a List<Object> to a List<String>.

Similar is the issue here. You can't cast Stream<Object> to Stream<Client>. Of course you can cast it indirectly like this:

Stream<Client> intStream = (Stream<Client>) (Stream<?>)stream;

but that is not safe, and might fail at runtime. The underlying reason for this is, generics in Java are implemented using erasure. So, there is no type information available about which type of Stream it is at runtime. Everything is just Stream.

BTW, what's wrong with your approach? Looks fine to me.

Specified cast is not valid?

Try this:

public void LoadData()
        {
            SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=Stocks;Integrated Security=True;Pooling=False");
            SqlDataAdapter sda = new SqlDataAdapter("Select * From [Stocks].[dbo].[product]", con);
            DataTable dt = new DataTable();
            sda.Fill(dt);
            DataGridView1.Rows.Clear();

        foreach (DataRow item in dt.Rows)
        {
            int n = DataGridView1.Rows.Add();
            DataGridView1.Rows[n].Cells[0].Value = item["ProductCode"].ToString();
            DataGridView1.Rows[n].Cells[1].Value = item["Productname"].ToString();
            DataGridView1.Rows[n].Cells[2].Value = item["qty"].ToString();                
            if ((bool)item["productstatus"])
            {
                DataGridView1.Rows[n].Cells[3].Value = "Active";
            }
            else
            {
                DataGridView1.Rows[n].Cells[3].Value = "Deactive";
            }

SQL update fields of one table from fields of another one

I have been working with IBM DB2 database for more then decade and now trying to learn PostgreSQL.

It works on PostgreSQL 9.3.4, but does not work on DB2 10.5:

UPDATE B SET
     COLUMN1 = A.COLUMN1,
     COLUMN2 = A.COLUMN2,
     COLUMN3 = A.COLUMN3
FROM A
WHERE A.ID = B.ID

Note: Main problem is FROM cause that is not supported in DB2 and also not in ANSI SQL.

It works on DB2 10.5, but does NOT work on PostgreSQL 9.3.4:

UPDATE B SET
    (COLUMN1, COLUMN2, COLUMN3) =
               (SELECT COLUMN1, COLUMN2, COLUMN3 FROM A WHERE ID = B.ID)

FINALLY! It works on both PostgreSQL 9.3.4 and DB2 10.5:

UPDATE B SET
     COLUMN1 = (SELECT COLUMN1 FROM A WHERE ID = B.ID),
     COLUMN2 = (SELECT COLUMN2 FROM A WHERE ID = B.ID),
     COLUMN3 = (SELECT COLUMN3 FROM A WHERE ID = B.ID)

How to turn on front flash light programmatically in Android?

For this problem you should:

  1. Check whether the flashlight is available or not?

  2. If so then Turn Off/On

  3. If not then you can do whatever, according to your app needs.

For Checking availability of flash in the device:

You can use the following:

 context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);

which will return true if a flash is available, false if not.

See:
http://developer.android.com/reference/android/content/pm/PackageManager.html for more information.

For turning on/off flashlight:

I googled out and got this about android.permission.FLASHLIGHT. Android manifests' permission looks promising:

 <!-- Allows access to the flashlight -->
 <permission android:name="android.permission.FLASHLIGHT"
             android:permissionGroup="android.permission-group.HARDWARE_CONTROLS"
             android:protectionLevel="normal"
             android:label="@string/permlab_flashlight"
             android:description="@string/permdesc_flashlight" />

Then make use of Camera and set Camera.Parameters. The main parameter used here is FLASH_MODE_TORCH.

eg.

Code Snippet to turn on camera flashlight.

Camera cam = Camera.open();     
Parameters p = cam.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_TORCH);
cam.setParameters(p);
cam.startPreview();

Code snippet to turn off camera led light.

  cam.stopPreview();
  cam.release();

I just found a project that uses this permission. Check quick-settings' src code. here http://code.google.com/p/quick-settings/ (Note: This link is now broken)

For Flashlight directly look http://code.google.com/p/quick-settings/source/browse/trunk/quick-settings/#quick-settings/src/com/bwx/bequick/flashlight (Note: This link is now broken)

Update6 You could also try to add a SurfaceView as described in this answer LED flashlight on Galaxy Nexus controllable by what API? This seems to be a solution that works on many phones.

Update 5 Major Update

I have found an alternative Link (for the broken links above): http://www.java2s.com/Open-Source/Android/Tools/quick-settings/com.bwx.bequick.flashlight.htm You can now use this link. [Update: 14/9/2012 This link is now broken]

Update 1

Another OpenSource Code : http://code.google.com/p/torch/source/browse/

Update 2

Example showing how to enable the LED on a Motorola Droid: http://code.google.com/p/droidled/

Another Open Source Code :

http://code.google.com/p/covedesigndev/
http://code.google.com/p/search-light/

Update 3 (Widget for turning on/off camera led)

If you want to develop a widget that turns on/off your camera led, then you must refer my answer Widget for turning on/off camera flashlight in android..

Update 4

If you want to set the intensity of light emerging from camera LED you can refer Can I change the LED intensity of an Android device? full post. Note that only rooted HTC devices support this feature.

** Issues:**

There are also some problems while turning On/Off flashlight. eg. for the devices not having FLASH_MODE_TORCH or even if it has, then flashlight does not turn ON etc.

Typically Samsung creates a lot of problems.

You can refer to problems in the given below list:

Use camera flashlight in Android

Turn ON/OFF Camera LED/flash light in Samsung Galaxy Ace 2.2.1 & Galaxy Tab

How to create an on/off switch with Javascript/CSS?

Outline: Create two elements: a slider/switch and a trough as a parent of the slider. To toggle the state, switch the slider element between an "on" and an "off" class. In the style for one class, set "left" to 0 and leave "right" the default; for the other class, do the opposite:

<style type="text/css">
.toggleSwitch {
    width: ...;
    height: ...;
    /* add other styling as appropriate to position element */
    position: relative;
}
.slider {
    background-image: url(...);
    position: absolute;
    width: ...;
    height: ...;
}
.slider.on {
    right: 0;
}
.slider.off {
    left: 0;
}
</style>
<script type="text/javascript">
function replaceClass(elt, oldClass, newClass) {
    var oldRE = RegExp('\\b'+oldClass+'\\b');
    elt.className = elt.className.replace(oldRE, newClass);
}
function toggle(elt, on, off) {
    var onRE = RegExp('\\b'+on+'\\b');
    if (onRE.test(elt.className)) {
        elt.className = elt.className.replace(onRE, off);
    } else {
        replaceClass(elt, off, on);
    }
}
</script>
...
<div class="toggleSwitch" onclick="toggle(this.firstChild, 'on', 'off');"><div class="slider off" /></div>

Alternatively, just set the background image for the "on" and "off" states, which is a much easier approach than mucking about with positioning.

How can I create my own comparator for a map?

Yes, the 3rd template parameter on map specifies the comparator, which is a binary predicate. Example:

struct ByLength : public std::binary_function<string, string, bool>
{
    bool operator()(const string& lhs, const string& rhs) const
    {
        return lhs.length() < rhs.length();
    }
};

int main()
{
    typedef map<string, string, ByLength> lenmap;
    lenmap mymap;

    mymap["one"] = "one";
    mymap["a"] = "a";
    mymap["fewbahr"] = "foobar";

    for( lenmap::const_iterator it = mymap.begin(), end = mymap.end(); it != end; ++it )
        cout << it->first << "\n";
}

Start an external application from a Google Chrome Extension?

I go for hypothesys since I can't verify now.

With Apache, if you make a php script on your local machine calling your executable, and then call this script via POST or GET via html/javascript?

would it function?

let me know.

Remove file from SVN repository without deleting local copy

Deleting files and folders

If you want to delete an item from the repository, but keep it locally as an unversioned file/folder, use Extended Context Menu ? Delete (keep local). You have to hold the Shift key while right clicking on the item in the explorer list pane (right pane) in order to see this in the extended context menu.

Delete completely:
right mouse click ? Menu ? Delete

Delete & Keep local:
Shift + right mouse click ? Menu ? Delete

Center a column using Twitter Bootstrap 3

Don't forget to add !important. Then you can be sure that element really will be in the center:

.col-centered{
  float: none !important;
  margin: 0 auto !important;
}

Append a single character to a string or char array in java?

1. String otherString = "helen" + character;

2. otherString +=  character;

In vb.net, how to get the column names from a datatable

This is how to retrieve a Column Name from a DataColumn:

MyDataTable.Columns(1).ColumnName 

To get the name of all DataColumns within your DataTable:

Dim name(DT.Columns.Count) As String
Dim i As Integer = 0
For Each column As DataColumn In DT.Columns
  name(i) = column.ColumnName
  i += 1
Next

References

What is the effect of extern "C" in C++?

Not any C-header can be made compatible with C++ by merely wrapping in extern "C". When identifiers in a C-header conflict with C++ keywords the C++ compiler will complain about this.

For example, I have seen the following code fail in a g++ :

extern "C" {
struct method {
    int virtual;
};
}

Kinda makes sense, but is something to keep in mind when porting C-code to C++.

Creating a .p12 file

The openssl documentation says that file supplied as the -in argument must be in PEM format.

Turns out that, contrary to the CA's manual, the certificate returned by the CA which I stored in myCert.cer is not PEM format rather it is PKCS7.

In order to create my .p12, I had to first convert the certificate to PEM:

openssl pkcs7 -in myCert.cer -print_certs -out certs.pem

and then execute

openssl pkcs12 -export -out keyStore.p12 -inkey myKey.pem -in certs.pem

How to select data from 30 days?

Try this : Using this you can select date by last 30 days,

SELECT DATEADD(DAY,-30,GETDATE())

How to add time to DateTime in SQL

DECLARE @DDate      date        -- To store the current date
DECLARE @DTime      time        -- To store the current time
DECLARE @DateTime   datetime    -- To store the result of the concatenation
;
SET @DDate      =   GETDATE()   -- Getting the current date
SET @DTime      =   GETDATE()   -- Getting the current time



SET @DateTime   =   CONVERT(datetime, CONVERT(varchar(19), LTRIM(@DDate) + ' ' + LTRIM(@DTime) ));
;
/*
    1. LTRIM the date and time do an automatic conversion of both types to string.
    2. The inside CONVERT to varchar(19) is needed, because you cannot do a direct conversion to datetime
    3. Once the inside conversion is done, the second do the final conversion to datetime.
*/  

-- The following select shows the initial variables and the result of the concatenation
SELECT @DDate, @DTime, @DateTime

How to set editable true/false EditText in Android programmatically?

How to do it programatically :

To enable EditText use:

et.setEnabled(true);

To disable EditText use:

et.setEnabled(false);

Mockito test a void method throws an exception

The parentheses are poorly placed.

You need to use:

doThrow(new Exception()).when(mockedObject).methodReturningVoid(...);
                                          ^

and NOT use:

doThrow(new Exception()).when(mockedObject.methodReturningVoid(...));
                                                                   ^

This is explained in the documentation

How to convert PDF files to images

https://www.codeproject.com/articles/317700/convert-a-pdf-into-a-series-of-images-using-csharp

I found this GhostScript wrapper to be working like a charm for converting the PDFs to PNGs, page by page.

Usage:

string pdf_filename = @"C:\TEMP\test.pdf";            
var pdf2Image = new Cyotek.GhostScript.PdfConversion.Pdf2Image(pdf_filename);
for (var page = 1; page < pdf2Image.PageCount; page++)
{
    string png_filename = @"C:\TEMP\test" + page + ".png";
    pdf2Image.ConvertPdfPageToImage(png_filename, page);
}

Being built on GhostScript, obviously for commercial application the licensing question remains.

How to combine two vectors into a data frame

Here's a simple function. It generates a data frame and automatically uses the names of the vectors as values for the first column.

myfunc <- function(a, b, names = NULL) {
  setNames(data.frame(c(rep(deparse(substitute(a)), length(a)), 
                        rep(deparse(substitute(b)), length(b))), c(a, b)), names)
}

An example:

x <-c(1,2,3)
y <-c(100,200,300)
x_name <- "cond"
y_name <- "rating"

myfunc(x, y, c(x_name, y_name))

  cond rating
1    x      1
2    x      2
3    x      3
4    y    100
5    y    200
6    y    300

store return value of a Python script in a bash script

sys.exit(myString) doesn't mean "return this string". If you pass a string to sys.exit, sys.exit will consider that string to be an error message, and it will write that string to stderr. The closest concept to a return value for an entire program is its exit status, which must be an integer.

If you want to capture output written to stderr, you can do something like

python yourscript 2> return_file

You could do something like that in your bash script

output=$((your command here) 2> &1)

This is not guaranteed to capture only the value passed to sys.exit, though. Anything else written to stderr will also be captured, which might include logging output or stack traces.

example:

test.py

print "something"
exit('ohoh') 

t.sh

va=$(python test.py 2>&1)                                                                                                                    
mkdir $va

bash t.sh

edit

Not sure why but in that case, I would write a main script and two other scripts... Mixing python and bash is pointless unless you really need to.

import script1
import script2

if __name__ == '__main__':
    filename = script1.run(sys.args)
    script2.run(filename)

How do I "un-revert" a reverted Git commit?

I had an issue somebody made a revert to master to my branch, but I was needed to be able to merge it again but the problem is that the revert included all my commit. Lets look at that case we created our feature branch from M1 we merge our feature branch in M3 and revert on it in RM3

M1 -> M2 -> M3 -> M4- > RM3 -> M5
 \.         /
  F1->F2 -

How to make the F2 able to merge to M5?

git checkout master
git checkout -b brach-before-revert
git reset --hard M4
git checkout master
git checkout -b new-feature-branch
git reset --hard M1 
git merge --squash brach-before-revert

How to create a file with a given size in Linux?

Please, modern is easier, and faster. On Linux, (pick one)

truncate -s 10G foo
fallocate -l 5G bar

It needs to be stated that truncate on a file system supporting sparse files will create a sparse file and fallocate will not. A sparse file is one where the allocation units that make up the file are not actually allocated until used. The meta-data for the file will however take up some considerable space but likely no where near the actual size of the file. You should consult resources about sparse files for more information as there are advantages and disadvantages to this type of file. A non-sparse file has its blocks (allocation units) allocated ahead of time which means the space is reserved as far as the file system sees it. Also fallocate nor truncate will not set the contents of the file to a specified value like dd, instead the contents of a file allocated with fallocate or truncate may be any trash value that existed in the allocated units during creation and this behavior may or may not be desired. The dd is the slowest because it actually writes the value or chunk of data to the entire file stream as specified with it's command line options.

This behavior could potentially be different - depending on file system used and conformance of that file system to any standard or specification. Therefore it is advised that proper research is done to ensure that the appropriate method is used.

How to fix Array indexOf() in JavaScript for Internet Explorer browsers

The full code then would be this:

if (!Array.prototype.indexOf) {
    Array.prototype.indexOf = function(obj, start) {
         for (var i = (start || 0), j = this.length; i < j; i++) {
             if (this[i] === obj) { return i; }
         }
         return -1;
    }
}

For a really thorough answer and code to this as well as other array functions check out Stack Overflow question Fixing JavaScript Array functions in Internet Explorer (indexOf, forEach, etc.).

Finding the second highest number in array

public class secondLargestElement 
{
    public static void main(String[] args) 
    {
        int []a1={1,0};
        secondHigh(a1);
    }

    public static void secondHigh(int[] arr)
    {
        try
        {
            int highest,sec_high;
            highest=arr[0];
            sec_high=arr[1];

                for(int i=1;i<arr.length;i++)
                {
                    if(arr[i]>highest)
                    {           
                        sec_high=highest;
                        highest=arr[i]; 
                    }
                    else 
                    // The first condition before the || is to make sure that second highest is not actually same as the highest , think 
                        // about {5,4,5}, you don't want the last  5 to be reported as the sec_high
                        // The other half after || says if the first two elements are same then also replace the sec_high with incoming integer
                        // Think about {5,5,4}
                    if(arr[i]>sec_high && arr[i]<highest || highest==sec_high)
                        sec_high=arr[i];
                }
            //System.out.println("high="+highest +"sec"+sec_high);
            if(highest==sec_high)
                System.out.println("All the elements in the input array are same");
             else
                 System.out.println("The second highest element in the array is:"+ sec_high);

         }

        catch(ArrayIndexOutOfBoundsException e)
        {
        System.out.println("Not enough elements in the array");
        //e.printStackTrace();
        }
    }
}

How to work with progress indicator in flutter?

Create a bool isLoading and set it to false. With the help of ternary operator, When user clicks on login button set state of isLoading to true. You will get circular loading indicator in place of login button

 isLoading ? new PrimaryButton(
                      key: new Key('login'),
                      text: 'Login',
                      height: 44.0,
                      onPressed: setState((){isLoading = true;}))
                  : Center(
                      child: CircularProgressIndicator(),
                    ),

You can see Screenshots how it looks while before login is clicked enter image description here

After login is clicked enter image description here

In mean time you can run login process and login user. If user credentials are wrong then again you will setState of isLoading to false, such that loading indicator will become invisible and login button visible to user. By the way, primaryButton used in code is my custom button. You can do same with OnPressed in button.

What is the difference between 'my' and 'our' in Perl?

The PerlMonks and PerlDoc links from cartman and Olafur are a great reference - below is my crack at a summary:

my variables are lexically scoped within a single block defined by {} or within the same file if not in {}s. They are not accessible from packages/subroutines defined outside of the same lexical scope / block.

our variables are scoped within a package/file and accessible from any code that use or require that package/file - name conflicts are resolved between packages by prepending the appropriate namespace.

Just to round it out, local variables are "dynamically" scoped, differing from my variables in that they are also accessible from subroutines called within the same block.

how to make negative numbers into positive

this is the only way i can think of doing it.

//positive to minus
int a = 5; // starting with 5 to become -5
int b = int a * 2; // b = 10
int c = a - b; // c = - 5;
std::cout << c << endl;
//outputs - 5


 //minus to positive
int a = -5; starting with -5 to become 5
int b = a * 2; 
// b = -10
int c = a + b 
// c = 5
std::cout << c << endl;
//outputs 5

Function examples

int b = 0;
int c = 0;


int positiveToNegative (int a) {
    int b = a * 2;
    int c = a - b;
    return c;
}

int negativeToPositive (int a) { 
    int b = a * 2;
    int c = a + b;
    return c; 
}

Restrict varchar() column to specific values?

Personally, I'd code it as tinyint and:

  • Either: change it to text on the client, check constraint between 1 and 4
  • Or: use a lookup table with a foreign key

Reasons:

  • It will take on average 8 bytes to store text, 1 byte for tinyint. Over millions of rows, this will make a difference.

  • What about collation? Is "Daily" the same as "DAILY"? It takes resources to do this kind of comparison.

  • Finally, what if you want to add "Biweekly" or "Hourly"? This requires a schema change when you could just add new rows to a lookup table.

How to center a Window in Java?

This should work in all versions of Java

public static void centreWindow(Window frame) {
    Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();
    int x = (int) ((dimension.getWidth() - frame.getWidth()) / 2);
    int y = (int) ((dimension.getHeight() - frame.getHeight()) / 2);
    frame.setLocation(x, y);
}

Programmatically add custom event in the iPhone Calendar

Update for swift 4 for Dashrath answer

import UIKit
import EventKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let eventStore = EKEventStore()

        eventStore.requestAccess( to: EKEntityType.event, completion:{(granted, error) in

            if (granted) && (error == nil) {


                let event = EKEvent(eventStore: eventStore)

                event.title = "My Event"
                event.startDate = Date(timeIntervalSinceNow: TimeInterval())
                event.endDate = Date(timeIntervalSinceNow: TimeInterval())
                event.notes = "Yeah!!!"
                event.calendar = eventStore.defaultCalendarForNewEvents

                var event_id = ""
                do{
                    try eventStore.save(event, span: .thisEvent)
                    event_id = event.eventIdentifier
                }
                catch let error as NSError {
                    print("json error: \(error.localizedDescription)")
                }

                if(event_id != ""){
                    print("event added !")
                }
            }
        })
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

also don't forget to add permission for calendar usage image for privary setting

Check if value exists in the array (AngularJS)

You can use indexOf(). Like:

var Color = ["blue", "black", "brown", "gold"];
var a = Color.indexOf("brown");
alert(a);

The indexOf() method searches the array for the specified item, and returns its position. And return -1 if the item is not found.


If you want to search from end to start, use the lastIndexOf() method:

    var Color = ["blue", "black", "brown", "gold"];
    var a = Color.lastIndexOf("brown");
    alert(a);

The search will start at the specified position, or at the end if no start position is specified, and end the search at the beginning of the array.

Returns -1 if the item is not found.

MySQL Trigger - Storing a SELECT in a variable

CREATE TRIGGER clearcamcdr AFTER INSERT ON `asteriskcdrdb`.`cdr` 
FOR EACH ROW
BEGIN
  SET @INC = (SELECT sip_inc FROM trunks LIMIT 1);
  IF NEW.billsec >1 AND NEW.channel LIKE @INC 
    AND NEW.dstchannel NOT LIKE "" 
  THEN
    insert into `asteriskcdrdb`.`filtre` (id_appel,date_appel,source,destinataire,duree,sens,commentaire,suivi) 
      values (NEW.id,NEW.calldate,NEW.src,NEW.dstchannel,NEW.billsec,"entrant","",""); 
  END IF;
END$$

Dont try this @ home

Date difference in minutes in Python

In case someone doesn't realize it, one way to do this would be to combine Christophe and RSabet's answers:

from datetime import datetime
import time

fmt = '%Y-%m-%d %H:%M:%S'
d1 = datetime.strptime('2010-01-01 17:31:22', fmt)
d2 = datetime.strptime('2010-01-03 20:15:14', fmt)

diff = d2 -d1
diff_minutes = (diff.days * 24 * 60) + (diff.seconds/60)

print(diff_minutes)
> 3043

Prevent textbox autofill with previously entered values

For firefox

Either:

<asp:TextBox id="Textbox1" runat="server" autocomplete="off"></asp:TextBox>

Or from the CodeBehind:

Textbox1.Attributes.Add("autocomplete", "off");

What is SuppressWarnings ("unchecked") in Java?

The SuppressWarning annotation is used to suppress compiler warnings for the annotated element. Specifically, the unchecked category allows suppression of compiler warnings generated as a result of unchecked type casts.

How do I format date value as yyyy-mm-dd using SSIS expression builder?

Looks like you created a separate question. I was answering your other question How to change flat file source using foreach loop container in an SSIS package? with the same answer. Anyway, here it is again.

Create two string data type variables namely DirPath and FilePath. Set the value C:\backup\ to the variable DirPath. Do not set any value to the variable FilePath.

Variables

Select the variable FilePath and select F4 to view the properties. Set the EvaluateAsExpression property to True and set the Expression property as @[User::DirPath] + "Source" + (DT_STR, 4, 1252) DATEPART("yy" , GETDATE()) + "-" + RIGHT("0" + (DT_STR, 2, 1252) DATEPART("mm" , GETDATE()), 2) + "-" + RIGHT("0" + (DT_STR, 2, 1252) DATEPART("dd" , GETDATE()), 2)

Expression

Setting onClickListener for the Drawable right of an EditText

Please use below trick:

  • Create an image button with your icon and set its background color to be transparent.
  • Put the image button on the EditText
  • Implement the 'onclic'k listener of the button to execute your function

What can cause intermittent ORA-12519 (TNS: no appropriate handler found) errors

Another solution I have found to a similar error but the same error message is to increase the number of service handlers found. (My instance of this error was caused by too many connections in the Weblogic Portal Connection pools.)

  • Run SQL*Plus and login as SYSTEM. You should know what password you’ve used during the installation of Oracle DB XE.
  • Run the command alter system set processes=150 scope=spfile; in SQL*Plus
  • VERY IMPORTANT: Restart the database.

From here:

http://www.atpeaz.com/index.php/2010/fixing-the-ora-12519-tnsno-appropriate-service-handler-found-error/

How to see which flags -march=native will activate?

To see command-line flags, use:

gcc -march=native -E -v - </dev/null 2>&1 | grep cc1

If you want to see the compiler/precompiler defines set by certain parameters, do this:

echo | gcc -dM -E - -march=native

How to get "GET" request parameters in JavaScript?

All data is available under

window.location.search

you have to parse the string, eg.

function get(name){
   if(name=(new RegExp('[?&]'+encodeURIComponent(name)+'=([^&]*)')).exec(location.search))
      return decodeURIComponent(name[1]);
}

just call the function with GET variable name as parameter, eg.

get('foo');

this function will return the variables value or undefined if variable has no value or doesn't exist

How to generate an openSSL key using a passphrase from the command line?

If you don't use a passphrase, then the private key is not encrypted with any symmetric cipher - it is output completely unprotected.

You can generate a keypair, supplying the password on the command-line using an invocation like (in this case, the password is foobar):

openssl genrsa -aes128 -passout pass:foobar 3072

However, note that this passphrase could be grabbed by any other process running on the machine at the time, since command-line arguments are generally visible to all processes.

A better alternative is to write the passphrase into a temporary file that is protected with file permissions, and specify that:

openssl genrsa -aes128 -passout file:passphrase.txt 3072

Or supply the passphrase on standard input:

openssl genrsa -aes128 -passout stdin 3072

You can also used a named pipe with the file: option, or a file descriptor.


To then obtain the matching public key, you need to use openssl rsa, supplying the same passphrase with the -passin parameter as was used to encrypt the private key:

openssl rsa -passin file:passphrase.txt -pubout

(This expects the encrypted private key on standard input - you can instead read it from a file using -in <file>).


Example of creating a 3072-bit private and public key pair in files, with the private key pair encrypted with password foobar:

openssl genrsa -aes128 -passout pass:foobar -out privkey.pem 3072
openssl rsa -in privkey.pem -passin pass:foobar -pubout -out privkey.pub

Granting DBA privileges to user in Oracle

You need only to write:

GRANT DBA TO NewDBA;

Because this already makes the user a DB Administrator

"google is not defined" when using Google Maps V3 in Firefox remotely

Changed the

<script type="text/javascript" src="https://maps.googleapis.com/maps/api/js?key=API"> 
      function(){
            myMap()
                }
</script>

and made it

<script type="text/javascript">
      function(){
            myMap()
                }
</script>
<script type="text/javascript" src="https://maps.googleapis.com/maps/api/js?key=API"></script>

It worked :)

When should use Readonly and Get only properties

readonly properties are used to create a fail-safe code. i really like the Encapsulation posts series of Mark Seemann about properties and backing fields:

http://blog.ploeh.dk/2011/05/24/PokayokeDesignFromSmellToFragrance.aspx

taken from Mark's example:

public class Fragrance : IFragrance
{
    private readonly string name;

    public Fragrance(string name)
    {
        if (name == null)
        {
            throw new ArgumentNullException("name");
        }

        this.name = name;
    }

    public string Spread()
    {
        return this.name;
    }
}

in this example you use the readonly name field to make sure the class invariant is always valid. in this case the class composer wanted to make sure the name field is set only once (immutable) and is always present.

Visibility of global variables in imported modules

This post is just an observation for Python behaviour I encountered. Maybe the advices you read above don't work for you if you made the same thing I did below.

Namely, I have a module which contains global/shared variables (as suggested above):

#sharedstuff.py

globaltimes_randomnode=[]
globalist_randomnode=[]

Then I had the main module which imports the shared stuff with:

import sharedstuff as shared

and some other modules that actually populated these arrays. These are called by the main module. When exiting these other modules I can clearly see that the arrays are populated. But when reading them back in the main module, they were empty. This was rather strange for me (well, I am new to Python). However, when I change the way I import the sharedstuff.py in the main module to:

from globals import *

it worked (the arrays were populated).

Just sayin'

C/C++ check if one bit is set in, i.e. int variable

There is, namely the _bittest intrinsic instruction.

java.lang.Exception: No runnable methods exception in running JUnits

In my case I had wrong package imported:

import org.testng.annotations.Test;

instead of

import org.junit.Test;

Beware of your ide autocomplete.

Python copy files to a new directory and rename if file name already exists

I always use the time-stamp - so its not possible, that the file exists already:

import os
import shutil
import datetime

now = str(datetime.datetime.now())[:19]
now = now.replace(":","_")

src_dir="C:\\Users\\Asus\\Desktop\\Versand Verwaltung\\Versand.xlsx"
dst_dir="C:\\Users\\Asus\\Desktop\\Versand Verwaltung\\Versand_"+str(now)+".xlsx"
shutil.copy(src_dir,dst_dir)

What is an .axd file?

An AXD file is a file used by ASP.NET applications for handling embedded resource requests. It contains instructions for retrieving embedded resources, such as images, JavaScript (.JS) files, and.CSS files. AXD files are used for injecting resources into the client-side webpage and access them on the server in a standard way.

Is there a vr (vertical rule) in html?

You could create a custom tag as such:

<html>
<head>
<style>
vr {
display: inline-block;
// This is where you'd set the ruler color
background-color: black;
// This is where you'd set the ruler width
width: 2px;
//this is where you'd set the spacing between the ruler and surrounding text
margin: 0px 5px 0px 5px;
height: 100%;
vertical-align: top;
}
</style>
</head>
<body>
this is text <vr></vr> more text
</body>
</html>

(If anyone knows a way that I could turn this into an "open-ended" tag, like <hr> let me know and I will edit it in)

Use of for_each on map elements

Here is an example of how you can use for_each for a map.

std::map<int, int> map;

map.insert(std::pair<int, int>(1, 2));
map.insert(std::pair<int, int>(2, 4));
map.insert(std::pair<int, int>(3, 6));

auto f = [](std::pair<int,int> it) {std::cout << it.first + it.second << std::endl; };
std::for_each(map.begin(), map.end(), f);

How to trigger the onclick event of a marker on a Google Maps V3?

I've found out the solution! Thanks to Firebug ;)

//"markers" is an array that I declared which contains all the marker of the map
//"i" is the index of the marker in the array that I want to trigger the OnClick event

//V2 version is:
GEvent.trigger(markers[i], 'click');

//V3 version is:
google.maps.event.trigger(markers[i], 'click');

How do I disable the security certificate check in Python requests

Also can be done from the environment variable:

export CURL_CA_BUNDLE=""

D3 transform scale and translate

Scott Murray wrote a great explanation of this[1]. For instance, for the code snippet:

svg.append("g")
    .attr("class", "axis")
    .attr("transform", "translate(0," + h + ")")
    .call(xAxis);

He explains using the following:

Note that we use attr() to apply transform as an attribute of g. SVG transforms are quite powerful, and can accept several different kinds of transform definitions, including scales and rotations. But we are keeping it simple here with only a translation transform, which simply pushes the whole g group over and down by some amount.

Translation transforms are specified with the easy syntax of translate(x,y), where x and y are, obviously, the number of horizontal and vertical pixels by which to translate the element.

[1]: From Chapter 8, "Cleaning it up" of Interactive Data Visualization for the Web, which used to be freely available and is now behind a paywall.

How to convert a boolean array to an int array

Most of the time you don't need conversion:

>>>array([True,True,False,False]) + array([1,2,3,4])
array([2, 3, 3, 4])

The right way to do it is:

yourArray.astype(int)

or

yourArray.astype(float)

How do I pass a command line argument while starting up GDB in Linux?

I'm using GDB7.1.1, as --help shows:

gdb [options] --args executable-file [inferior-arguments ...]

IMHO, the order is a bit unintuitive at first.

How to import a new font into a project - Angular 5

You can try creating a css for your font with font-face (like explained here)

Step #1

Create a css file with font face and place it somewhere, like in assets/fonts

customfont.css

@font-face {
    font-family: YourFontFamily;
    src: url("/assets/font/yourFont.otf") format("truetype");
}

Step #2

Add the css to your .angular-cli.json in the styles config

"styles":[
 //...your other styles
 "assets/fonts/customFonts.css"
 ]

Do not forget to restart ng serve after doing this

Step #3

Use the font in your code

component.css

span {font-family: YourFontFamily; }

How to format html table with inline styles to look like a rendered Excel table?

This is quick-and-dirty (and not formally valid HTML5), but it seems to work -- and it is inline as per the question:

<table border='1' style='border-collapse:collapse'>

No further styling of <tr>/<td> tags is required (for a basic table grid).

BehaviorSubject vs Observable?

An observable allows you to subscribe only whereas a subject allows you to both publish and subscribe.

So a subject allows your services to be used as both a publisher and a subscriber.

As of now, I'm not so good at Observable so I'll share only an example of Subject.

Let's understand better with an Angular CLI example. Run the below commands:

npm install -g @angular/cli

ng new angular2-subject

cd angular2-subject

ng serve

Replace the content of app.component.html with:

<div *ngIf="message">
  {{message}}
</div>

<app-home>
</app-home>

Run the command ng g c components/home to generate the home component. Replace the content of home.component.html with:

<input type="text" placeholder="Enter message" #message>
<button type="button" (click)="setMessage(message)" >Send message</button>

#message is the local variable here. Add a property message: string; to the app.component.ts's class.

Run this command ng g s service/message. This will generate a service at src\app\service\message.service.ts. Provide this service to the app.

Import Subject into MessageService. Add a subject too. The final code shall look like this:

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

@Injectable()
export class MessageService {

  public message = new Subject<string>();

  setMessage(value: string) {
    this.message.next(value); //it is publishing this value to all the subscribers that have already subscribed to this message
  }
}

Now, inject this service in home.component.ts and pass an instance of it to the constructor. Do this for app.component.ts too. Use this service instance for passing the value of #message to the service function setMessage:

import { Component } from '@angular/core';
import { MessageService } from '../../service/message.service';

@Component({
  selector: 'app-home',
  templateUrl: './home.component.html',
  styleUrls: ['./home.component.css']
})
export class HomeComponent {

  constructor(public messageService:MessageService) { }

  setMessage(event) {
    console.log(event.value);
    this.messageService.setMessage(event.value);
  }
}

Inside app.component.ts, subscribe and unsubscribe (to prevent memory leaks) to the Subject:

import { Component, OnDestroy } from '@angular/core';
import { MessageService } from './service/message.service';
import { Subscription } from 'rxjs/Subscription';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html'
})
export class AppComponent {

  message: string;
  subscription: Subscription;

  constructor(public messageService: MessageService) { }

  ngOnInit() {
    this.subscription = this.messageService.message.subscribe(
      (message) => {
        this.message = message;
      }
    );
  }

  ngOnDestroy() {
    this.subscription.unsubscribe();
  }
}

That's it.

Now, any value entered inside #message of home.component.html shall be printed to {{message}} inside app.component.html

How to parse JSON array in jQuery?

Careful with the eval, the JSON specs http://json.org/js.html recommend something like

var myObject = eval('(' + myJSONtext + ')');

And there may be some more gotchas. There is a plugin for jQuery that will take care of it, i guess:

http://code.google.com/p/jquery-json/

string.IsNullOrEmpty(string) vs. string.IsNullOrWhiteSpace(string)

The differences in practice :

string testString = "";
Console.WriteLine(string.Format("IsNullOrEmpty : {0}", string.IsNullOrEmpty(testString)));
Console.WriteLine(string.Format("IsNullOrWhiteSpace : {0}", string.IsNullOrWhiteSpace(testString)));
Console.ReadKey();

Result :
IsNullOrEmpty : True
IsNullOrWhiteSpace : True

**************************************************************
string testString = " MDS   ";

IsNullOrEmpty : False
IsNullOrWhiteSpace : False

**************************************************************
string testString = "   ";

IsNullOrEmpty : False
IsNullOrWhiteSpace : True

**************************************************************
string testString = string.Empty;

IsNullOrEmpty : True
IsNullOrWhiteSpace : True

**************************************************************
string testString = null;

IsNullOrEmpty : True
IsNullOrWhiteSpace : True

Common CSS Media Queries Break Points

Instead of using pixels should use em or percentage as it is more adaptive and fluid, better not target devices target your content:

HTML5 rockrs read, mobile first

How to print a percentage value in python?

format supports a percentage floating point precision type:

>>> print "{0:.0%}".format(1./3)
33%

If you don't want integer division, you can import Python3's division from __future__:

>>> from __future__ import division
>>> 1 / 3
0.3333333333333333

# The above 33% example would could now be written without the explicit
# float conversion:
>>> print "{0:.0f}%".format(1/3 * 100)
33%

# Or even shorter using the format mini language:
>>> print "{:.0%}".format(1/3)
33%

Run a controller function whenever a view is opened/shown

Following up on the answer and link from AlexMart, something like this works:

.controller('MyCtrl', function($scope) {
  $scope.$on('$ionicView.enter', function() {
     // Code you want executed every time view is opened
     console.log('Opened!')
  })
})

How can I create a keystore?

To answer the question in the title, you create a keystore with the Java Keytool utility that comes with any standard JDK distribution and can be located at %JAVA_HOME%\bin. On Windows this would usually be C:\Program Files\Java\jre7\bin.

So on Windows, open a command window and switch to that directory and enter a command like this

keytool -genkey -v -keystore my-release-key.keystore -alias alias_name -keyalg RSA -keysize 2048 -validity 10000

Keytool prompts you to provide passwords for the keystore, provide the Distinguished Name fields and then the password for your key. It then generates the keystore as a file called my-release-key.keystore in the directory you're in. The keystore and key are protected by the passwords you entered. The keystore contains a single key, valid for 10000 days. The alias_name is a name that you — will use later, to refer to this keystore when signing your application.

For more information about Keytool, see the documentation at: http://docs.oracle.com/javase/6/docs/technotes/tools/windows/keytool.html

and for more information on signing Android apps go here: http://developer.android.com/tools/publishing/app-signing.html

How to Use UTF-8 Collation in SQL Server database?

UTF-8 is not a character set, it's an encoding. The character set for UTF-8 is Unicode. If you want to store Unicode text you use the nvarchar data type.

If the database would use UTF-8 to store text, you would still not get the text out as encoded UTF-8 data, you would get it out as decoded text.

You can easily store UTF-8 encoded text in the database, but then you don't store it as text, you store it as binary data (varbinary).

Proper way to return JSON using node or Express

Older version of Express use app.use(express.json()) or bodyParser.json() read more about bodyParser middleware

On latest version of express we could simply use res.json()

const express = require('express'),
    port = process.env.port || 3000,
    app = express()

app.get('/', (req, res) => res.json({key: "value"}))

app.listen(port, () => console.log(`Server start at ${port}`))

Setting user agent of a java URLConnection

HTTP Servers tend to reject old browsers and systems.

The page Tech Blog (wh): Most Common User Agents reflects the user-agent property of your current browser in section "Your user agent is:", which can be applied to set the request property "User-Agent" of a java.net.URLConnection or the system property "http.agent".

Test if executable exists in Python?

For python 3.3 and later:

import shutil

command = 'ls'
shutil.which(command) is not None

As a one-liner of Jan-Philip Gehrcke Answer:

cmd_exists = lambda x: shutil.which(x) is not None

As a def:

def cmd_exists(cmd):
    return shutil.which(cmd) is not None

For python 3.2 and earlier:

my_command = 'ls'
any(
    (
        os.access(os.path.join(path, my_command), os.X_OK) 
        and os.path.isfile(os.path.join(path, my_command)
    )
    for path in os.environ["PATH"].split(os.pathsep)
)

This is a one-liner of Jay's Answer, Also here as a lambda func:

cmd_exists = lambda x: any((os.access(os.path.join(path, x), os.X_OK) and os.path.isfile(os.path.join(path, x))) for path in os.environ["PATH"].split(os.pathsep))
cmd_exists('ls')

Or lastly, indented as a function:

def cmd_exists(cmd, path=None):
    """ test if path contains an executable file with name
    """
    if path is None:
        path = os.environ["PATH"].split(os.pathsep)

    for prefix in path:
        filename = os.path.join(prefix, cmd)
        executable = os.access(filename, os.X_OK)
        is_not_directory = os.path.isfile(filename)
        if executable and is_not_directory:
            return True
    return False

Iterating through a JSON object

for iterating through JSON you can use this:

json_object = json.loads(json_file)
for element in json_object: 
    for value in json_object['Name_OF_YOUR_KEY/ELEMENT']:
        print(json_object['Name_OF_YOUR_KEY/ELEMENT']['INDEX_OF_VALUE']['VALUE'])

ORA-00054: resource busy and acquire with NOWAIT specified

Step 1:

select object_name, s.sid, s.serial#, p.spid 
from v$locked_object l, dba_objects o, v$session s, v$process p
where l.object_id = o.object_id and l.session_id = s.sid and s.paddr = p.addr;

Step 2:

alter system kill session 'sid,serial#'; --`sid` and `serial#` get from step 1

More info: http://www.oracle-base.com/articles/misc/killing-oracle-sessions.php

Extracting specific columns in numpy array

I assume you wanted columns 1 and 9?

To select multiple columns at once, use

X = data[:, [1, 9]]

To select one at a time, use

x, y = data[:, 1], data[:, 9]

With names:

data[:, ['Column Name1','Column Name2']]

You can get the names from data.dtype.names

How to specify Memory & CPU limit in docker compose version 3

I know the topic is a bit old and seems stale, but anyway I was able to use these options:

    deploy:
      resources:
        limits:
          cpus: '0.001'
          memory: 50M

when using 3.7 version of docker-compose

What helped in my case, was using this command:

docker-compose --compatibility up

--compatibility flag stands for (taken from the documentation):

If set, Compose will attempt to convert deploy keys in v3 files to their non-Swarm equivalent

Think it's great, that I don't have to revert my docker-compose file back to v2.

Incorrect syntax near ''

I was using ADO.NET and was using SQL Command as:

 string query =
"SELECT * " +
"FROM table_name" +
"Where id=@id";

the thing was i missed a whitespace at the end of "FROM table_name"+ So basically it said

string query = "SELECT * FROM table_nameWHERE id=@id";

and this was causing the error.

Hope it helps

Remove gutter space for a specific div only

Since no one has mentioned this, to add to the no-gutter answer above which works, if you want custom spaced gutters, all you have to do is specify the value in px for the margin left and right properties, and padding left and right properties like so;

.row.no-gutter {
margin-left: 4px;
margin-right: 4px;
}

.row.no-gutter [class*='col-']:not(:first-child),
.row.no-gutter [class*='col-']:not(:last-child) {
padding-right: 4px;
padding-left: 4px;
}

Why are you not able to declare a class as static in Java?

One can look at PlatformUI in Eclipse for a class with static methods and private constructor with itself being final.

public final class <class name>
{
   //static constants
   //static memebers
}

Update UI from Thread in Android

Use the AsyncTask class (instead of Runnable). It has a method called onProgressUpdate which can affect the UI (it's invoked in the UI thread).

Numpy: Creating a complex array from 2 real ones?

That worked for me:

input:

[complex(a,b) for a,b in zip([1,2,3],[1,2,3])]

output:

[(1+4j), (2+5j), (3+6j)]

Java: Identifier expected

Try it like this instead, move your myclass items inside a main method:

    class UserInput {
      public void name() {
        System.out.println("This is a test.");
      }
    }

    public class MyClass {

        public static void main( String args[] )
        {
            UserInput input = new UserInput();
            input.name();
        }

    }

Include CSS and Javascript in my django template

First, create staticfiles folder. Inside that folder create css, js, and img folder.

settings.py

import os

PROJECT_DIR = os.path.dirname(__file__)

DATABASES = {
    'default': {
         'ENGINE': 'django.db.backends.sqlite3', 
         'NAME': os.path.join(PROJECT_DIR, 'myweblabdev.sqlite'),                        
         'USER': '',
         'PASSWORD': '',
         'HOST': '',                      
         'PORT': '',                     
    }
}

MEDIA_ROOT = os.path.join(PROJECT_DIR, 'media')

MEDIA_URL = '/media/'

STATIC_ROOT = os.path.join(PROJECT_DIR, 'static')

STATIC_URL = '/static/'

STATICFILES_DIRS = (
    os.path.join(PROJECT_DIR, 'staticfiles'),
)

main urls.py

from django.conf.urls import patterns, include, url
from django.conf.urls.static import static
from django.contrib import admin
from django.contrib.staticfiles.urls import staticfiles_urlpatterns
from myweblab import settings

admin.autodiscover()

urlpatterns = patterns('',
    .......
) + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

urlpatterns += staticfiles_urlpatterns()

template

{% load static %}

<link rel="stylesheet" href="{% static 'css/style.css' %}">

join on multiple columns

Below is the structure of SQL that you may write. You can do multiple joins by using "AND" or "OR".

Select TableA.Col1, TableA.Col2, TableB.Val
FROM TableA, 
INNER JOIN TableB
 ON TableA.Col1 = TableB.Col1 OR TableA.Col2 = TableB.Col2

How do I open a Visual Studio project in design view?

From the Solution Explorer window select your form, right-click, click on View Designer. Voila! The form should display.

I tried posting a couple screenshots, but this is my first post; therefore, I could not post any images.

adding noise to a signal in python

In real life you wish to simulate a signal with white noise. You should add to your signal random points that have Normal Gaussian distribution. If we speak about a device that have sensitivity given in unit/SQRT(Hz) then you need to devise standard deviation of your points from it. Here I give function "white_noise" that does this for you, an the rest of a code is demonstration and check if it does what it should.

%matplotlib inline
import numpy as np
import matplotlib.pyplot as plt
from scipy import signal

"""
parameters: 
rhp - spectral noise density unit/SQRT(Hz)
sr  - sample rate
n   - no of points
mu  - mean value, optional

returns:
n points of noise signal with spectral noise density of rho
"""
def white_noise(rho, sr, n, mu=0):
    sigma = rho * np.sqrt(sr/2)
    noise = np.random.normal(mu, sigma, n)
    return noise

rho = 1 
sr = 1000
n = 1000
period = n/sr
time = np.linspace(0, period, n)
signal_pure = 100*np.sin(2*np.pi*13*time)
noise = white_noise(rho, sr, n)
signal_with_noise = signal_pure + noise

f, psd = signal.periodogram(signal_with_noise, sr)

print("Mean spectral noise density = ",np.sqrt(np.mean(psd[50:])), "arb.u/SQRT(Hz)")

plt.plot(time, signal_with_noise)
plt.plot(time, signal_pure)
plt.xlabel("time (s)")
plt.ylabel("signal (arb.u.)")
plt.show()

plt.semilogy(f[1:], np.sqrt(psd[1:]))
plt.xlabel("frequency (Hz)")
plt.ylabel("psd (arb.u./SQRT(Hz))")
#plt.axvline(13, ls="dashed", color="g")
plt.axhline(rho, ls="dashed", color="r")
plt.show()

Signal with noise

PSD

Best practice for Django project working directory structure

Here is what I follow on My system.

  1. All Projects: There is a projects directory in my home folder i.e. ~/projects. All the projects rest inside it.

  2. Individual Project: I follow a standardized structure template used by many developers called django-skel for individual projects. It basically takes care of all your static file and media files and all.

  3. Virtual environment: I have a virtualenvs folder inside my home to store all virtual environments in the system i.e. ~/virtualenvs . This gives me flexibility that I know what all virtual environments I have and can look use easily

The above 3 are the main partitions of My working environment.

All the other parts you mentioned are mostly dependent on project to project basis (i.e. you might use different databases for different projects). So they should reside in their individual projects.

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

 void main(){
  var x = "4";
  int number = int.parse(x);//STRING to INT

  var y = "4.6";
  double doubleNum = double.parse(y);//STRING to DOUBLE

  var z = 55;
  String myStr = z.toString();//INT to STRING
}

int.parse() and double.parse() can throw an error when it couldn't parse the String

Get value from SimpleXMLElement Object

try current($xml->code[0]->lat)

it returns element under current pointer of array, which is 0, so you will get value

The program can't start because libgcc_s_dw2-1.dll is missing

If you are wondering where you can download the shared library (although this will not work on your client's devices unless you include the dll) here is the link: https://de.osdn.net/projects/mingw/downloads/72215/libgcc-9.2.0-1-mingw32-dll-1.tar.xz/

TypeError("'bool' object is not iterable",) when trying to return a Boolean

Look at the traceback:

Traceback (most recent call last):
  File "C:\Python33\lib\site-packages\bottle.py", line 821, in _cast
    out = iter(out)
TypeError: 'bool' object is not iterable

Your code isn't iterating the value, but the code receiving it is.

The solution is: return an iterable. I suggest that you either convert the bool to a string (str(False)) or enclose it in a tuple ((False,)).

Always read the traceback: it's correct, and it's helpful.

Fatal error in launcher: Unable to create process using ""C:\Program Files (x86)\Python33\python.exe" "C:\Program Files (x86)\Python33\pip.exe""

I had a simpler solution. Using @apple way but rename main.py to pip.py then put it in your python version scripts folder and add scripts folder to your path access it globally. if you don't want to add it to path you have to cd to scripts and then run pip command.

How to decode jwt token in javascript without using a library?

I use this function to get payload , header , exp(Expiration Time), iat (Issued At) based on this answer

function parseJwt(token) {
  try {
    // Get Token Header
    const base64HeaderUrl = token.split('.')[0];
    const base64Header = base64HeaderUrl.replace('-', '+').replace('_', '/');
    const headerData = JSON.parse(window.atob(base64Header));

    // Get Token payload and date's
    const base64Url = token.split('.')[1];
    const base64 = base64Url.replace('-', '+').replace('_', '/');
    const dataJWT = JSON.parse(window.atob(base64));
    dataJWT.header = headerData;

// TODO: add expiration at check ...


    return dataJWT;
  } catch (err) {
    return false;
  }
}

const jwtDecoded = parseJwt('YOUR_TOKEN') ;
if(jwtDecoded)
{
    console.log(jwtDecoded)
}

How to redirect to logon page when session State time out is completed in asp.net mvc

One way is that In case of Session Expire, in every action you have to check its session and if it is null then redirect to Login page.

But this is very hectic method To over come this you need to create your own ActionFilterAttribute which will do this, you just need to add this attribute in every action method.

Here is the Class which overrides ActionFilterAttribute.

public class SessionExpireFilterAttribute : ActionFilterAttribute
    {
        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            HttpContext ctx = HttpContext.Current;

            // check if session is supported
            CurrentCustomer objCurrentCustomer = new CurrentCustomer();
            objCurrentCustomer = ((CurrentCustomer)SessionStore.GetSessionValue(SessionStore.Customer));
            if (objCurrentCustomer == null)
            {
                // check if a new session id was generated
                filterContext.Result = new RedirectResult("~/Users/Login");
                return;
            }

            base.OnActionExecuting(filterContext);
        }
    }

Then in action just add this attribute like so:

[SessionExpire]
public ActionResult Index()
{
     return Index();
}

This will do you work.

How to trigger jQuery change event in code

$(selector).change()

.change()


.trigger("change")

Longer slower alternative, better for abstraction.

.trigger("change")

$(selector).trigger("change")

How to extend a class in python?

class MyParent:

    def sayHi():
        print('Mamma says hi')
from path.to.MyParent import MyParent

class ChildClass(MyParent):
    pass

An instance of ChildClass will then inherit the sayHi() method.

Android: Unable to add window. Permission denied for this window type

Firstly you make sure you have add permission in manifest file.

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

Check if the application has draw over other apps permission or not? This permission is by default available for API<23. But for API > 23 you have to ask for the permission in runtime.

 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && !Settings.canDrawOverlays(this)) {

    Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION,
            Uri.parse("package:" + getPackageName()));
    startActivityForResult(intent, 1);
} 

Use This code:

public class ChatHeadService extends Service {

private WindowManager mWindowManager;
private View mChatHeadView;

WindowManager.LayoutParams params;

public ChatHeadService() {
}

@Override
public IBinder onBind(Intent intent) {
    return null;
}

@Override
public void onCreate() {
    super.onCreate();

    Language language = new Language();
    //Inflate the chat head layout we created
    mChatHeadView = LayoutInflater.from(this).inflate(R.layout.dialog_incoming_call, null);


    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
        params = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.TYPE_PHONE,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
                        | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
                        | WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH
                        | WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS,
                PixelFormat.TRANSLUCENT);

        params.gravity = Gravity.CENTER_HORIZONTAL | Gravity.TOP;
        params.x = 0;
        params.y = 100;
        mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
        mWindowManager.addView(mChatHeadView, params);

    } else {
        params = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.WRAP_CONTENT,
                WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY,
                WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
                        | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
                        | WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH
                        | WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS,
                PixelFormat.TRANSLUCENT);


        params.gravity = Gravity.CENTER_HORIZONTAL | Gravity.TOP;
        params.x = 0;
        params.y = 100;
        mWindowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
        mWindowManager.addView(mChatHeadView, params);
    }

    TextView tvTitle=mChatHeadView.findViewById(R.id.tvTitle);
    tvTitle.setText("Incoming Call");

    //Set the close button.
    Button btnReject = (Button) mChatHeadView.findViewById(R.id.btnReject);
    btnReject.setText(language.getText(R.string.reject));
    btnReject.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //close the service and remove the chat head from the window
            stopSelf();
        }
    });

    //Drag and move chat head using user's touch action.
    final Button btnAccept = (Button) mChatHeadView.findViewById(R.id.btnAccept);
    btnAccept.setText(language.getText(R.string.accept));


    LinearLayout linearLayoutMain=mChatHeadView.findViewById(R.id.linearLayoutMain);



    linearLayoutMain.setOnTouchListener(new View.OnTouchListener() {
        private int lastAction;
        private int initialX;
        private int initialY;
        private float initialTouchX;
        private float initialTouchY;

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:

                    //remember the initial position.
                    initialX = params.x;
                    initialY = params.y;

                    //get the touch location
                    initialTouchX = event.getRawX();
                    initialTouchY = event.getRawY();

                    lastAction = event.getAction();
                    return true;
                case MotionEvent.ACTION_UP:
                    //As we implemented on touch listener with ACTION_MOVE,
                    //we have to check if the previous action was ACTION_DOWN
                    //to identify if the user clicked the view or not.
                    if (lastAction == MotionEvent.ACTION_DOWN) {
                        //Open the chat conversation click.
                        Intent intent = new Intent(ChatHeadService.this, HomeActivity.class);
                        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                        startActivity(intent);

                        //close the service and remove the chat heads
                        stopSelf();
                    }
                    lastAction = event.getAction();
                    return true;
                case MotionEvent.ACTION_MOVE:
                    //Calculate the X and Y coordinates of the view.
                    params.x = initialX + (int) (event.getRawX() - initialTouchX);
                    params.y = initialY + (int) (event.getRawY() - initialTouchY);

                    //Update the layout with new X & Y coordinate
                    mWindowManager.updateViewLayout(mChatHeadView, params);
                    lastAction = event.getAction();
                    return true;
            }
            return false;
        }
    });
}

@Override
public void onDestroy() {
    super.onDestroy();
    if (mChatHeadView != null) mWindowManager.removeView(mChatHeadView);
}

}

How to refresh Gridview after pressed a button in asp.net

I was totally lost on why my Gridview.Databind() would not refresh.

My issue, I discovered, was my gridview was inside a UpdatePanel. To get my GridView to FINALLY refresh was this:

gvServerConfiguration.Databind()
uppServerConfiguration.Update()

uppServerConfiguration is the id associated with my UpdatePanel in my asp.net code.

Hope this helps someone.

How do you get the current text contents of a QComboBox?

You can convert the QString type to python string by just using the str function. Assuming you are not using any Unicode characters you can get a python string as below:

text = str(combobox1.currentText())

If you are using any unicode characters, you can do:

text = unicode(combobox1.currentText())

In C#, how to check whether a string contains an integer?

You can check if string contains numbers only:

Regex.IsMatch(myStringVariable, @"^-?\d+$")

But number can be bigger than Int32.MaxValue or less than Int32.MinValue - you should keep that in mind.

Another option - create extension method and move ugly code there:

public static bool IsInteger(this string s)
{
   if (String.IsNullOrEmpty(s))
       return false;

   int i;
   return Int32.TryParse(s, out i);
}

That will make your code more clean:

if (myStringVariable.IsInteger())
    // ...

This version of the application is not configured for billing through Google Play

SOLUTION

Just hold on a while after uploading your app on play store because google takes some time to update app versions.It will work !

What is the @Html.DisplayFor syntax for?

I think the main benefit would be when you define your own Display Templates, or use Data annotations.

So for example if your title was a date, you could define

[DisplayFormat(DataFormatString = "{0:d}")]

and then on every page it would display the value in a consistent manner. Otherwise you may have to customise the display on multiple pages. So it does not help much for plain strings, but it does help for currencies, dates, emails, urls, etc.

For example instead of an email address being a plain string it could show up as a link:

<a href="mailto:@ViewData.Model">@ViewData.TemplateInfo.FormattedModelValue</a>

Pandas index column title or name

If you do not want to create a new row but simply put it in the empty cell then use:

df.columns.name = 'foo'

Otherwise use:

df.index.name = 'foo'

Total size of the contents of all the files in a directory

There are at least three ways to get the "sum total of all the data in files and subdirectories" in bytes that work in both Linux/Unix and Git Bash for Windows, listed below in order from fastest to slowest on average. For your reference, they were executed at the root of a fairly deep file system (docroot in a Magento 2 Enterprise installation comprising 71,158 files in 30,027 directories).

1.

$ time find -type f -printf '%s\n' | awk '{ total += $1 }; END { print total" bytes" }'
748660546 bytes

real    0m0.221s
user    0m0.068s
sys     0m0.160s

2.

$ time echo `find -type f -print0 | xargs -0 stat --format=%s | awk '{total+=$1} END {print total}'` bytes
748660546 bytes

real    0m0.256s
user    0m0.164s
sys     0m0.196s

3.

$ time echo `find -type f -exec du -bc {} + | grep -P "\ttotal$" | cut -f1 | awk '{ total += $1 }; END { print total }'` bytes
748660546 bytes

real    0m0.553s
user    0m0.308s
sys     0m0.416s


These two also work, but they rely on commands that don't exist on Git Bash for Windows:

1.

$ time echo `find -type f -printf "%s + " | dc -e0 -f- -ep` bytes
748660546 bytes

real    0m0.233s
user    0m0.116s
sys     0m0.176s

2.

$ time echo `find -type f -printf '%s\n' | paste -sd+ | bc` bytes
748660546 bytes

real    0m0.242s
user    0m0.104s
sys     0m0.152s


If you only want the total for the current directory, then add -maxdepth 1 to find.


Note that some of the suggested solutions don't return accurate results, so I would stick with the solutions above instead.

$ du -sbh
832M    .

$ ls -lR | grep -v '^d' | awk '{total += $5} END {print "Total:", total}'
Total: 583772525

$ find . -type f | xargs stat --format=%s | awk '{s+=$1} END {print s}'
xargs: unmatched single quote; by default quotes are special to xargs unless you use the -0 option
4390471

$ ls -l| grep -v '^d'| awk '{total = total + $5} END {print "Total" , total}'
Total 968133

Pyspark: Filter dataframe based on multiple conditions

Your logic condition is wrong. IIUC, what you want is:

import pyspark.sql.functions as f

df.filter((f.col('d')<5))\
    .filter(
        ((f.col('col1') != f.col('col3')) | 
         (f.col('col2') != f.col('col4')) & (f.col('col1') == f.col('col3')))
    )\
    .show()

I broke the filter() step into 2 calls for readability, but you could equivalently do it in one line.

Output:

+----+----+----+----+---+
|col1|col2|col3|col4|  d|
+----+----+----+----+---+
|   A|  xx|   D|  vv|  4|
|   A|   x|   A|  xx|  3|
|   E| xxx|   B|  vv|  3|
|   F|xxxx|   F| vvv|  4|
|   G| xxx|   G|  xx|  4|
+----+----+----+----+---+

Are HTTP headers case-sensitive?

They are not case sensitive. In fact NodeJS web server explicitly converts them to lower-case, before making them available in the request object.

It's important to note here that all headers are represented in lower-case only, regardless of how the client actually sent them. This simplifies the task of parsing headers for whatever purpose.

Security of REST authentication schemes

Remember that your suggestions makes it difficult for clients to communicate with the server. They need to understand your innovative solution and encrypt the data accordingly, this model is not so good for public API (unless you are amazon\yahoo\google..).

Anyways, if you must encrypt the body content I would suggest you to check out existing standards and solutions like:

XML encryption (W3C standard)

XML Security

HTML img align="middle" doesn't align an image

remove float: left from image css and add text-align: center property in parent element body

_x000D_
_x000D_
        <!DOCTYPE html>_x000D_
<html>_x000D_
<body style="text-align: center;">_x000D_
_x000D_
    <img_x000D_
        src="http://icons.iconarchive.com/icons/rokey/popo-emotions/128/big-smile-icon.png"_x000D_
        width="42" height="42"_x000D_
        align="middle"_x000D_
        style="_x000D_
          _x000D_
          display: block;_x000D_
          margin-left: auto;_x000D_
          margin-right: auto;_x000D_
          z-index: 1;"_x000D_
        >_x000D_
_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

How to disable all div content

This is for the searchers,

The best I did is,

$('#myDiv *').attr("disabled", true);                   
$('#myDiv *').fadeTo('slow', .6);

Deleting all pending tasks in celery / rabbitmq

1. To properly purge the queue of waiting tasks you have to stop all the workers (http://celery.readthedocs.io/en/latest/faq.html#i-ve-purged-messages-but-there-are-still-messages-left-in-the-queue):

$ sudo rabbitmqctl stop

or (in case RabbitMQ/message broker is managed by Supervisor):

$ sudo supervisorctl stop all

2. ...and then purge the tasks from a specific queue:

$ cd <source_dir>
$ celery amqp queue.purge <queue name>

3. Start RabbitMQ:

$ sudo rabbitmqctl start

or (in case RabbitMQ is managed by Supervisor):

$ sudo supervisorctl start all

JavaScript: Difference between .forEach() and .map()

Diffrence between Foreach & map :

Map() : If you use map then map can return new array by iterating main array.

Foreach() : If you use Foreach then it can not return anything for each can iterating main array.

useFul link : use this link for understanding diffrence

https://codeburst.io/javascript-map-vs-foreach-f38111822c0f

"Eliminate render-blocking CSS in above-the-fold content"

Hi For jQuery You can only use like this

Use async and type="text/javascript" only

How can I store and retrieve images from a MySQL database using PHP?

Instead of storing images in database store them in a folder in your disk and store their location in your data base.

How do you run a command as an administrator from the Windows command line?

I would set up a shortcut, either to CMD or to the thing you want to run, then set the properties of the shortcut to require admin, and then run the shortcut from your batch file. I haven't tested to confirm it will respect the properties, but I think it's more elegant and doesn't require activating the Administrator account.

Also if you do it as a scheduled task (which can be set up from code) there is an option to run it elevated there.

How to Force New Google Spreadsheets to refresh and recalculate?

When the problem is in the recalculation of an IF condition, I add AND(ISDATE(NOW());condition) so that the cell is forced to recalculate according to what is set in the Calculation tab in Spreadsheet Settings as explained before.

This works because NOW is one of the functions that is affected by the Calculation setting and ISDATE(NOW()) always returns TRUE.

For example, in one of my sheets I had the following condition which I use to check whether a sheet with name stored in C1 is already created:

=IF(ISREF(INDIRECT(C$1&"!A1")); TRUE; FALSE)

In this case C1="February", so I expected the condition to become TRUE when a sheet with this name was created, which didn't happen. To force it to update, I changed the Calculation setting and used:

=IF(AND( ISDATE(NOW()) ; ISREF(INDIRECT(C$1&"!A1")) ); TRUE; FALSE)

How to make a edittext box in a dialog

Setting margin in layout params will not work in Alertdialog. you have to set padding in parent layout and then add edittext in that layout.

This is my working kotlin code...

val alert =  AlertDialog.Builder(context!!)

val edittext = EditText(context!!)
edittext.hint = "Enter Name"
edittext.maxLines = 1

val layout = FrameLayout(context!!)

//set padding in parent layout
layout.setPaddingRelative(45,15,45,0)

alert.setTitle(title)

layout.addView(edittext)

alert.setView(layout)

alert.setPositiveButton(getString(R.string.label_save), DialogInterface.OnClickListener {

    dialog, which ->
    run {

        val qName = edittext.text.toString()

        Utility.hideKeyboard(context!!, dialogView!!)

    }

})
alert.setNegativeButton(getString(R.string.label_cancel), DialogInterface.OnClickListener {

            dialog, which ->
            run {
                dismiss()
            }

})

alert.show()

Passing an array by reference

It is a syntax. In the function arguments int (&myArray)[100] parenthesis that enclose the &myArray are necessary. if you don't use them, you will be passing an array of references and that is because the subscript operator [] has higher precedence over the & operator.

E.g. int &myArray[100] // array of references

So, by using type construction () you tell the compiler that you want a reference to an array of 100 integers.

E.g int (&myArray)[100] // reference of an array of 100 ints