What is the use of static variable in C#? When to use it? Why can't I declare the static variable inside method?

You don't need to instantiate an object, because yau are going to use a static variable: Console.WriteLine(Book.myInt);

how to convert object into string in php

In your case, you should simply use

$firstapiOutput->document_number

as the input for the second api.

How to format DateTime to 24 hours time?

Use upper-case HH for 24h format:

String s = curr.ToString("HH:mm");

See DateTime.ToString Method.

Awk if else issues

Try the code

awk '{s=($3==0)?"-":$3/$4; print s}'

Get paragraph text inside an element

If you use eg. "id" you can do it this way:

_x000D_

   (function() {_x000D_
    let x = document.getElementById("idName");_x000D_
    let y = document.getElementById("liName");_x000D_
    _x000D_
    y.addEventListener('click', function(e) {_x000D_
        y.appendChild(x);_x000D_
    });_x000D_
_x000D_
  _x000D_
})();

_x000D_

<html lang="en">_x000D_
_x000D_
<head>_x000D_
    <title></title>_x000D_
    <meta charset="UTF-8">_x000D_
    <meta name="viewport" content="width=device-width, initial-scale=1.0">_x000D_
</head>_x000D_
_x000D_
<body>_x000D_
    <p id="idName">TEXT</p>_x000D_
    <ul>_x000D_
        <li id="liName">_x000D_
_x000D_
        </li>_x000D_
    </ul>_x000D_
</body>_x000D_
<script src="js/scripts/script.js"></script>_x000D_
_x000D_
</html>

_x000D_

File upload along with other object in Jersey restful web service

I used file upload example from,

http://www.mkyong.com/webservices/jax-rs/file-upload-example-in-jersey/

in my resource class i have below method

@POST
    @Path("/upload")
    @Consumes(MediaType.MULTIPART_FORM_DATA)
    public Response  attachupload(@FormDataParam("file") byte[] is,
@FormDataParam("file") FormDataContentDisposition fileDetail,
@FormDataParam("fileName") String flename){
attachService.saveAttachment(flename,is);
}

in my attachService.java i have below method

 public void saveAttachment(String flename,  byte[] is) {
            // TODO Auto-generated method stub
         attachmentDao.saveAttachment(flename,is);

        }

in Dao i have

attach.setData(is);
attach.setFileName(flename);

in my HBM mapping is like

<property name="data" type="binary" >
            <column name="data" />
</property>

This working for all type of files like .PDF,.TXT, .PNG etc.,

Converting file size in bytes to human-readable string

Here is a prototype to convert a number to a readable string respecting the new international standards.

There are two ways to represent big numbers: You could either display them in multiples of 1000 = 10 3 (base 10) or 1024 = 2 10 (base 2). If you divide by 1000, you probably use the SI prefix names, if you divide by 1024, you probably use the IEC prefix names. The problem starts with dividing by 1024. Many applications use the SI prefix names for it and some use the IEC prefix names. The current situation is a mess. If you see SI prefix names you do not know whether the number is divided by 1000 or 1024

https://wiki.ubuntu.com/UnitsPolicy

http://en.wikipedia.org/wiki/Template:Quantities_of_bytes

Object.defineProperty(Number.prototype,'fileSize',{value:function(a,b,c,d){
 return (a=a?[1e3,'k','B']:[1024,'K','iB'],b=Math,c=b.log,
 d=c(this)/c(a[0])|0,this/b.pow(a[0],d)).toFixed(2)
 +' '+(d?(a[1]+'MGTPEZY')[--d]+a[2]:'Bytes');
},writable:false,enumerable:false});

This function contains no loop, and so it's probably faster than some other functions.

Usage:

IEC prefix

console.log((186457865).fileSize()); // default IEC (power 1024)
//177.82 MiB
//KiB,MiB,GiB,TiB,PiB,EiB,ZiB,YiB

SI prefix

console.log((186457865).fileSize(1)); //1,true for SI (power 1000)
//186.46 MB 
//kB,MB,GB,TB,PB,EB,ZB,YB

i set the IEC as default because i always used binary mode to calculate the size of a file... using the power of 1024

If you just want one of them in a short oneliner function:

function fileSizeSI(a,b,c,d,e){
 return (b=Math,c=b.log,d=1e3,e=c(a)/c(d)|0,a/b.pow(d,e)).toFixed(2)
 +' '+(e?'kMGTPEZY'[--e]+'B':'Bytes')
}
//kB,MB,GB,TB,PB,EB,ZB,YB

IEC

function fileSizeIEC(a,b,c,d,e){
 return (b=Math,c=b.log,d=1024,e=c(a)/c(d)|0,a/b.pow(d,e)).toFixed(2)
 +' '+(e?'KMGTPEZY'[--e]+'iB':'Bytes')
}
//KiB,MiB,GiB,TiB,PiB,EiB,ZiB,YiB

Usage:

console.log(fileSizeIEC(7412834521));

if you have some questions about the functions just ask

bootstrap 4 responsive utilities visible / hidden xs sm lg not working

Bootstrap 4 (^beta) has changed the classes for responsive hiding/showing elements. See this link for correct classes to use: http://getbootstrap.com/docs/4.0/utilities/display/#hiding-elements

Force decimal point instead of comma in HTML5 number input (client-side)

use the pattern

<input 
       type="number" 
       name="price"
       pattern="[0-9]+([\.,][0-9]+)?" 
       step="0.01"
       title="This should be a number with up to 2 decimal places."
>

good luck

Handling onchange event in HTML.DropDownList Razor MVC

The way of dknaack does not work for me, I found this solution as well:

@Html.DropDownList("Chapters", ViewBag.Chapters as SelectList, 
                    "Select chapter", new { @onchange = "location = this.value;" })

where

@Html.DropDownList(controlName, ViewBag.property + cast, "Default value", @onchange event)

In the controller you can add:

DbModel db = new DbModel();    //entity model of Entity Framework

ViewBag.Chapters = new SelectList(db.T_Chapter, "Id", "Name");

Spring boot Security Disable security

As previously multiple solutions mentioned to disable security through commenting of

@EnableWebSecurity

annotation and other is through properties in application.properties or yml. But those properties are showing as deprecated in latest spring boot version.

So, I would like to share another approach to configure default username and password in your application-dev.properties or application-dev.yml and use them to login into swagger and etc in development environment.

spring.security.user.name=admin
spring.security.user.password=admin

So, this approach will also provides you some kind of security as well and you can share this information with your development team. You can also configure user roles as well, but its not required in development level.

Insert using LEFT JOIN and INNER JOIN

INSERT INTO Test([col1],[col2]) (
    SELECT 
        a.Name AS [col1],
        b.sub AS [col2] 
    FROM IdTable b 
    INNER JOIN Nametable a ON b.no = a.no
)

How to make an Android Spinner with initial text "Select One"?

Seems a banal solution but I usually put simply a TextView in the front of the spinner. The whole Xml looks like this. (hey guys, don't shoot me, I know that some of you don't like this kind of marriage):

<FrameLayout
    android:id="@+id/selectTypesLinear"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >

    <Spinner
        android:id="@+id/spinnerExercises"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:entries="@array/exercise_spinner_entries"
        android:prompt="@string/exercise_spinner_prompt"
     />                         
    <TextView
        android:id="@+id/spinnerSelectText"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:text="Hey! Select this guy!"
        android:gravity="center"
        android:background="#FF000000" />


</FrameLayout>

Then I hide the TextView when an Item was selected. Obviously the background color of the TextView should be the same as the Spinner. Works on Android 4.0. Don't know on older versions.

Yes. Because the Spinner calls setOnItemSelectedListener at the beginning, the hiding of the textview could be a little bit tricky, but can be done this way:

    Boolean controlTouched;

    exerciseSpinner.setOnTouchListener(new OnTouchListener() {


        @Override
        public boolean onTouch(View v, MotionEvent event) {
            controlTouched = true; // I touched it but but not yet selected an Item.
            return false;
        }

    });
    exerciseSpinner.setOnItemSelectedListener(new OnItemSelectedListener() {

        @Override
        public void onItemSelected(AdapterView<?> arg0, View arg1,
                int arg2, long arg3) {
            if (controlTouched) { // Are you sure that I touched it with my fingers and not someone else  ?
                spinnerSelText.setVisibility(View.GONE);
            }
        }

        @Override
        public void onNothingSelected(AdapterView<?> arg0) {
        }

    });

Populate one dropdown based on selection in another

Setup mine within a closure and with straight JavaScript, explanation provided in comments

_x000D_

(function() {_x000D_
_x000D_
  //setup an object fully of arrays_x000D_
  //alternativly it could be something like_x000D_
  //{"yes":[{value:sweet, text:Sweet}.....]}_x000D_
  //so you could set the label of the option tag something different than the name_x000D_
  var bOptions = {_x000D_
    "yes": ["sweet", "wohoo", "yay"],_x000D_
    "no": ["you suck!", "common son"]_x000D_
  };_x000D_
_x000D_
  var A = document.getElementById('A');_x000D_
  var B = document.getElementById('B');_x000D_
_x000D_
  //on change is a good event for this because you are guarenteed the value is different_x000D_
  A.onchange = function() {_x000D_
    //clear out B_x000D_
    B.length = 0;_x000D_
    //get the selected value from A_x000D_
    var _val = this.options[this.selectedIndex].value;_x000D_
    //loop through bOption at the selected value_x000D_
    for (var i in bOptions[_val]) {_x000D_
      //create option tag_x000D_
      var op = document.createElement('option');_x000D_
      //set its value_x000D_
      op.value = bOptions[_val][i];_x000D_
      //set the display label_x000D_
      op.text = bOptions[_val][i];_x000D_
      //append it to B_x000D_
      B.appendChild(op);_x000D_
    }_x000D_
  };_x000D_
  //fire this to update B on load_x000D_
  A.onchange();_x000D_
_x000D_
})();

_x000D_

<select id='A' name='A'>_x000D_
  <option value='yes' selected='selected'>yes_x000D_
  <option value='no'> no_x000D_
</select>_x000D_
<select id='B' name='B'>_x000D_
</select>

_x000D_

Does Google Chrome work with Selenium IDE (as Firefox does)?

Just fyi . This is available as nuget package in visual studio environment. Please let me know if you need more information as I have used it. URL can be found Link to nuget

You can also find some information here. Blog with more details

Hot to get all form elements values using jQuery?

I needed to get the form data as some sort of object. I used this:

$('#preview_form').serializeArray().reduce((function(acc, val) {
  acc[val.name.replace('[', '_').replace(']', '')] = val.value;
  return acc;
}), {});

C pointers and arrays: [Warning] assignment makes pointer from integer without a cast

int[] and int* are represented the same way, except int[] allocates (IIRC).

ap is a pointer, therefore giving it the value of an integer is dangerous, as you have no idea what's at address 45.

when you try to access it (x = *ap), you try to access address 45, which causes the crash, as it probably is not a part of the memory you can access.

In where shall I use isset() and !empty()

Please consider behavior may change on different PHP versions

From documentation

isset() Returns TRUE if var exists and has any value other than NULL. FALSE otherwise https://www.php.net/manual/en/function.isset.php

empty() does not exist or if its value equals FALSE https://www.php.net/manual/en/function.empty.php

(empty($x) == (!isset($x) || !$x)) // returns true;

(!empty($x) == (isset($x) && $x)) // returns true;

"register" keyword in C?

During the seventies, at the very beginning of the C language, the register keyword has been introduced in order to allow the programmer to give hints to the compiler, telling it that the variable would be used very often, and that it should be wise to keep it’s value in one of the processor’s internal register.

Nowadays, optimizers are much more efficient than programmers to determine variables that are more likely to be kept into registers, and the optimizer does not always take the programmer’s hint into account.

So many people wrongly recommend not to use the register keyword.

Let’s see why!

The register keyword has an associated side effect: you can not reference (get the address of) a register type variable.

People advising others not to use registers takes wrongly this as an additional argument.

However, the simple fact of knowing that you can not take the address of a register variable, allows the compiler (and its optimizer) to know that the value of this variable can not be modified indirectly through a pointer.

When at a certain point of the instruction stream, a register variable has its value assigned in a processor’s register, and the register has not been used since to get the value of another variable, the compiler knows that it does not need to re-load the value of the variable in that register. This allows to avoid expensive useless memory access.

Do your own tests and you will get significant performance improvements in your most inner loops.

c_register_side_effect_performance_boost

Select last N rows from MySQL

SELECT * FROM table ORDER BY id DESC LIMIT 50

save resources make one query, there is no need to make nested queries

Installed Ruby 1.9.3 with RVM but command line doesn't show ruby -v

Open Terminal.
Go to Edit -> Profile Preferences.
Select the Title & command Tab in the window opened.
Mark the checkbox Run command as login shell.
close the window and restart the Terminal.

Check this Official Link enter image description here

How to refer to relative paths of resources when working with a code repository

If you are using setup tools or distribute (a setup.py install) then the "right" way to access these packaged resources seem to be using package_resources.

In your case the example would be

import pkg_resources
my_data = pkg_resources.resource_string(__name__, "foo.dat")

Which of course reads the resource and the read binary data would be the value of my_data

If you just need the filename you could also use

resource_filename(package_or_requirement, resource_name)

Example:

resource_filename("MyPackage","foo.dat")

The advantage is that its guaranteed to work even if it is an archive distribution like an egg.

See http://packages.python.org/distribute/pkg_resources.html#resourcemanager-api

How to post a file from a form with Axios

How to post file using an object in memory (like a JSON object):

import axios from 'axios';
import * as FormData  from 'form-data'

async function sendData(jsonData){
    // const payload = JSON.stringify({ hello: 'world'});
    const payload = JSON.stringify(jsonData);
    const bufferObject = Buffer.from(payload, 'utf-8');
    const file = new FormData();

    file.append('upload_file', bufferObject, "b.json");

    const response = await axios.post(
        lovelyURL,
        file,
        headers: file.getHeaders()
    ).toPromise();


    console.log(response?.data);
}

Check if property has attribute

There's no fast way to retrieve attributes. But code ought to look like this (credit to Aaronaught):

var t = typeof(YourClass);
var pi = t.GetProperty("Id");
var hasIsIdentity = Attribute.IsDefined(pi, typeof(IsIdentity));

If you need to retrieve attribute properties then

var t = typeof(YourClass);
var pi = t.GetProperty("Id");
var attr = (IsIdentity[])pi.GetCustomAttributes(typeof(IsIdentity), false);
if (attr.Length > 0) {
    // Use attr[0], you'll need foreach on attr if MultiUse is true
}

$ is not a function - jQuery error

<script type="text/javascript">
    $("ol li:nth-child(1)").addClass('olli1');
    $("ol li:nth-child(2)").addClass("olli2");
    $("ol li:nth-child(3)").addClass("olli3");
    $("ol li:nth-child(4)").addClass("olli4");
    $("ol li:nth-child(5)").addClass("olli5");
    $("ol li:nth-child(6)").addClass("olli6");
    $("ol li:nth-child(7)").addClass("olli7");
    $("ol li:nth-child(8)").addClass("olli8");
    $("ol li:nth-child(9)").addClass("olli9");
    $("ol li:nth-child(10)").addClass("olli10");
    $("ol li:nth-child(11)").addClass("olli11");
    $("ol li:nth-child(12)").addClass("olli12");
    $("ol li:nth-child(13)").addClass("olli13");
    $("ol li:nth-child(14)").addClass("olli14");
    $("ol li:nth-child(15)").addClass("olli15");
    $("ol li:nth-child(16)").addClass("olli16");
    $("ol li:nth-child(17)").addClass("olli17");
    $("ol li:nth-child(18)").addClass("olli18");
    $("ol li:nth-child(19)").addClass("olli19");
    $("ol li:nth-child(20)").addClass("olli20"); 
</script>

change this to

    <script type="text/javascript">
        jQuery(document).ready(function ($) {
        $("ol li:nth-child(1)").addClass('olli1');
        $("ol li:nth-child(2)").addClass("olli2");
        $("ol li:nth-child(3)").addClass("olli3");
        $("ol li:nth-child(4)").addClass("olli4");
        $("ol li:nth-child(5)").addClass("olli5");
        $("ol li:nth-child(6)").addClass("olli6");
        $("ol li:nth-child(7)").addClass("olli7");
        $("ol li:nth-child(8)").addClass("olli8");
        $("ol li:nth-child(9)").addClass("olli9");
        $("ol li:nth-child(10)").addClass("olli10");
        $("ol li:nth-child(11)").addClass("olli11");
        $("ol li:nth-child(12)").addClass("olli12");
        $("ol li:nth-child(13)").addClass("olli13");
        $("ol li:nth-child(14)").addClass("olli14");
        $("ol li:nth-child(15)").addClass("olli15");
        $("ol li:nth-child(16)").addClass("olli16");
        $("ol li:nth-child(17)").addClass("olli17");
        $("ol li:nth-child(18)").addClass("olli18");
        $("ol li:nth-child(19)").addClass("olli19");
        $("ol li:nth-child(20)").addClass("olli20"); 
     });
    </script>

How to completely DISABLE any MOUSE CLICK

You can overlay a big, semi-transparent <div> that takes all the clicks. Just append a new <div> to <body> with this style:

.overlay {
    background-color: rgba(1, 1, 1, 0.7);
    bottom: 0;
    left: 0;
    position: fixed;
    right: 0;
    top: 0;
}

Import local function from a module housed in another directory with relative imports in Jupyter Notebook using Python 3

I had almost the same example as you in this notebook where I wanted to illustrate the usage of an adjacent module's function in a DRY manner.

My solution was to tell Python of that additional module import path by adding a snippet like this one to the notebook:

import os
import sys
module_path = os.path.abspath(os.path.join('..'))
if module_path not in sys.path:
    sys.path.append(module_path)

This allows you to import the desired function from the module hierarchy:

from project1.lib.module import function
# use the function normally
function(...)

Note that it is necessary to add empty __init__.py files to project1/ and lib/ folders if you don't have them already.

How to put multiple statements in one line?

maybe with "and" or "or"

after false need to write "or"

after true need to write "and"

n=0
def returnsfalse():
    global n
    n=n+1
    print ("false %d" % (n))
    return False
def returnstrue():
    global n
    n=n+1
    print ("true %d" % (n))
    return True
n=0
returnsfalse() or  returnsfalse() or returnsfalse() or returnstrue() and returnsfalse()

result:

false 1
false 2
false 3
true 4
false 5

or maybe like

(returnsfalse() or true) and (returnstrue() or true) and ...

got here by searching google "how to put multiple statments in one line python", not answers question directly, maybe somebody else needs this.

Return array in a function

As above mentioned paths are correct. But i think if we just return a local array variable of a function sometimes it returns garbage values as its elements.

in-order to avoid that i had to create the array dynamically and proceed. Which is something like this.

int* func()
{
  int* Arr = new int[100];
  return Arr;
}

int main()
{
  int* ArrResult = func();
  cout << ArrResult[0] << " " << ArrResult[1] << endl;
  return 0;
}

Logo image and H1 heading on the same line

Try this:

Put both elements in a container DIV.
Give that container the property overflow:auto
Float both elements to the left using float:left
Give the H1 a width so that it doesn't take up the full width of it's parent container.

iPhone App Icons - Exact Radius?

You can make four icons (as of today) for your app and they can all have a different look - not necessarily based on the 512x512 image.

corner radius for the 512x512 icon = 80 (iTunesArtwork)
corner radius for the 1024x1024 icon = 180 (iTunesArtwork Retina)
corner radius for the 57x57 icon = 9 (iPhone/iPod Touch)
corner radius for the 114x114 icon = 18 (iPhone/iPod Touch Retina)
corner radius for the 72x72 icon = 11 (iPad)
corner radius for the 144x144 icon = 23 (iPad Retina)

If you do create a set of custom icons, you can set the UIPrerenderedIcon option to true in your info.plist file and it will not add the gloss effect but it will place a black background under it and still round the image corners with these corner radii so if the corner radius on any of the icons is greater then it will show black around the edges/corners.

Edit: See comment from @devin-g-rhode and you can see that any future icon sizes should have a 1:6.4 ratio of corner radius to icon size. There is also a very good answer from https://stackoverflow.com/a/29550364/396005 which has the location of image mask files used in the SDK for rounding icon corners

To add a retina-compatible file, use the same file name and add '@2x'. So if I had a file for my 72x72 icon named icon.png, I would also add a 114x114 PNG file named [email protected] to the project/target and Xcode would automatically use that as the icon on a retina display. You can see this in action on the Summary page of the application target if you've done it right. The same works for your launch images. Use launch.png at 320x480 and [email protected] at 640x960.

What exactly does the "u" do? "git push -u origin master" vs "git push origin master"

In more simple terms:

Technically, the -u flag adds a tracking reference to the upstream server you are pushing to.

What is important here is that this lets you do a git pull without supplying any more arguments. For example, once you do a git push -u origin master, you can later call git pull and git will know that you actually meant git pull origin master.

Otherwise, you'd have to type in the whole command.

What is the difference between Cloud, Grid and Cluster?

my two cents worth ~

Cloud refers to an (imaginary/easily scalable) unlimited space and processing power. The term shields the underlying technologies and highlights solely its unlimited storage-space and power.

Grid is a group of physically close-by machines setup. Term usually imply the processing power (ie:MFLOPS/GFLOPS), referred by engineers

Cluster is a set of logically connected machines/device (like a clusters of harddisk, cluster of database). Term highlights how devices are able to connect together and operate as a unit, referred by engineers

Javascript - removing undefined fields from an object

var obj = { a: 1, b: undefined, c: 3 }

To remove undefined props in an object we use like this

JSON.parse(JSON.stringify(obj));

Output: {a: 1, c: 3}

How to vertically center a "div" element for all browsers using CSS?

Unfortunately — but not surprisingly — the solution is more complicated than one would wish it to be. Also unfortunately, you'll need to use additional divs around the div you want vertically centered.

For standards-compliant browsers like Mozilla, Opera, Safari, etc. you need to set the outer div to be displayed as a table and the inner div to be displayed as a table-cell — which can then be vertically centered. For Internet Explorer, you need to position the inner div absolutely within the outer div and then specify the top as 50%. The following pages explain this technique well and provide some code samples too:

Vertical Centering in CSS
~~Vertical Centering in CSS with Unknown Height (Internet Explorer 7 compatible)~~ (no longer live)
Vertical Centering in CSS with Unknown Height (Internet Explorer 7 compatible) (Archived article courtesy of the Wayback Machine)

There is also a technique to do the vertical centering using JavaScript. Vertical alignment of content with JavaScript & CSS demonstrates it.

How to make Java work with SQL Server?

If you are use sqljdbc4.jar, use the following code

ResultSet objResultSet = objPreparedStatement.getResultSet();
if (objResultSet == null) {
  boolean bResult = false;
  while (!bResult){
    if (objPreparedStatement.getMoreResults()){
      objResultSet = objPreparedStatement.getResultSet();
      bResult = true;
    }
  } 
}
objCachedRowSet = new CachedRowSetImpl();
objCachedRowSet.populate(objResultSet);
if (CommonUtility.isValidObject(objResultSet)) objResultSet.close();
objResultSet = null;

Avoid line break between html elements

nobr is too unreliable, use tables

<table>
      <tr>
          <td> something </td>
          <td> something </td>
      </tr>
</table>

It all goes on the same line, everything is level with eachother, and you have much more freedom if you want to change something later.

ADB Android Device Unauthorized

It's likely that the device is no longer authorized on ADB for whatever reason.

1. Check if authorized:

<ANDROID_SDK_HOME>\platform-tools>adb devices
List of devices attached
4df798d76f98cf6d        unauthorized

2. Revoke USB Debugging on phone

If the device is shown as unauthorized, go to the developer options on the phone and click "Revoke USB debugging authorization" (tested with JellyBean & Samsung GalaxyIII).

3. Restart ADB Server:

Then restarted adb server

adb kill-server
adb start-server

4. Reconnect the device

The device will ask if you are agree to connect the computer id. You need to confirm it.

5. Now Check the device

It is now authorized!

adb devices
<ANDROID_SDK_HOME>\platform-tools>adb devices
List of devices attached
4df798d76f98cf6d        device

How to make a 3-level collapsing menu in Bootstrap?

Bootstrap 3 dropped native support for nested collapsing menus, but there's a way to re-enable it with a 3rd party script. It's called SmartMenus. It means adding three new resources to your page, but it seamlessly supports Bootstrap 3.x with multiple levels of menus for nested <ul>/<li> elements with class="dropdown-menu". It automatically displays the proper caret indicator as well.

<head>
   ...
   <script src=".../jquery.smartmenus.min.js"></script>
   <script src=".../jquery.smartmenus.bootstrap.min.js"></script>
   ...
   <link rel="stylesheet" href=".../jquery.smartmenus.bootstrap.min.css"/>
   ...
</head>

Here's a demo page: http://vadikom.github.io/smartmenus/src/demo/bootstrap-navbar-fixed-top.html

What is the LD_PRELOAD trick?

LD_PRELOAD lists shared libraries with functions that override the standard set, just as /etc/ld.so.preload does. These are implemented by the loader /lib/ld-linux.so. If you want to override just a few selected functions, you can do this by creating an overriding object file and setting LD_PRELOAD; the functions in this object file will override just those functions leaving others as they were.

For more information on shared libraries visit http://tldp.org/HOWTO/Program-Library-HOWTO/shared-libraries.html

What is Hash and Range Primary Key?

As the whole thing is mixing up let's look at it function and code to simulate what it means consicely

The only way to get a row is via primary key

getRow(pk: PrimaryKey): Row

Primary key data structure can be this:

// If you decide your primary key is just the partition key.
class PrimaryKey(partitionKey: String)

// and in thids case
getRow(somePartitionKey): Row

However you can decide your primary key is partition key + sort key in this case:

// if you decide your primary key is partition key + sort key
class PrimaryKey(partitionKey: String, sortKey: String)

getRow(partitionKey, sortKey): Row
getMultipleRows(partitionKey): Row[]

So the bottom line:

Decided that your primary key is partition key only? get single row by partition key.

Decided that your primary key is partition key + sort key? 2.1 Get single row by (partition key, sort key) or get range of rows by (partition key)

In either way you get a single row by primary key the only question is if you defined that primary key to be partition key only or partition key + sort key

Building blocks are:

Table
Item
KV Attribute.

Think of Item as a row and of KV Attribute as cells in that row.

You can get an item (a row) by primary key.
You can get multiple items (multiple rows) by specifying (HashKey, RangeKeyQuery)

You can do (2) only if you decided that your PK is composed of (HashKey, SortKey).

More visually as its complex, the way I see it:

+----------------------------------------------------------------------------------+
|Table                                                                             |
|+------------------------------------------------------------------------------+  |
||Item                                                                          |  |
||+-----------+ +-----------+ +-----------+ +-----------+                       |  |
|||primaryKey | |kv attr    | |kv attr ...| |kv attr ...|                       |  |
||+-----------+ +-----------+ +-----------+ +-----------+                       |  |
|+------------------------------------------------------------------------------+  |
|+------------------------------------------------------------------------------+  |
||Item                                                                          |  |
||+-----------+ +-----------+ +-----------+ +-----------+ +-----------+         |  |
|||primaryKey | |kv attr    | |kv attr ...| |kv attr ...| |kv attr ...|         |  |
||+-----------+ +-----------+ +-----------+ +-----------+ +-----------+         |  |
|+------------------------------------------------------------------------------+  |
|                                                                                  |
+----------------------------------------------------------------------------------+

+----------------------------------------------------------------------------------+
|1. Always get item by PrimaryKey                                                  |
|2. PK is (Hash,RangeKey), great get MULTIPLE Items by Hash, filter/sort by range     |
|3. PK is HashKey: just get a SINGLE ITEM by hashKey                               |
|                                                      +--------------------------+|
|                                 +---------------+    |getByPK => getBy(1        ||
|                 +-----------+ +>|(HashKey,Range)|--->|hashKey, > < or startWith ||
|              +->|Composite  |-+ +---------------+    |of rangeKeys)             ||
|              |  +-----------+                        +--------------------------+|
|+-----------+ |                                                                   |
||PrimaryKey |-+                                                                   |
|+-----------+ |                                       +--------------------------+|
|              |  +-----------+   +---------------+    |getByPK => get by specific||
|              +->|HashType   |-->|get one item   |--->|hashKey                   ||
|                 +-----------+   +---------------+    |                          ||
|                                                      +--------------------------+|
+----------------------------------------------------------------------------------+

So what is happening above. Notice the following observations. As we said our data belongs to (Table, Item, KVAttribute). Then Every Item has a primary key. Now the way you compose that primary key is meaningful into how you can access the data.

If you decide that your PrimaryKey is simply a hash key then great you can get a single item out of it. If you decide however that your primary key is hashKey + SortKey then you could also do a range query on your primary key because you will get your items by (HashKey + SomeRangeFunction(on range key)). So you can get multiple items with your primary key query.

Note: I did not refer to secondary indexes.

Moving Git repository content to another repository preserving history

Perfectly described here https://www.smashingmagazine.com/2014/05/moving-git-repository-new-server/

First, we have to fetch all of the remote branches and tags from the existing repository to our local index:

git fetch origin

We can check for any missing branches that we need to create a local copy of:

git branch -a

Let’s use the SSH-cloned URL of our new repository to create a new remote in our existing local repository:

git remote add new-origin [email protected]:manakor/manascope.git

Now we are ready to push all local branches and tags to the new remote named new-origin:

git push --all new-origin 
git push --tags new-origin

Let’s make new-origin the default remote:

git remote rm origin

Rename new-origin to just origin, so that it becomes the default remote:

git remote rename new-origin origin

How to change Status Bar text color in iOS

This works in Golden Master iOS 7 and Xcode 5 GM seed and iOS7 SDK released on September 18th, 2013 (at least with navigation controller hidden):

Set the UIViewControllerBasedStatusBarAppearance to NO in the Info.plist.
In ViewDidLoad method or anywhere, where do you want to change status bar style: [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];

span with onclick event inside a tag

You could use jQuery

http://jsfiddle.net/Bdqv7/

Why does integer division in C# return an integer and not a float?

While it is common for new programmer to make this mistake of performing integer division when they actually meant to use floating point division, in actual practice integer division is a very common operation. If you are assuming that people rarely use it, and that every time you do division you'll always need to remember to cast to floating points, you are mistaken.

First off, integer division is quite a bit faster, so if you only need a whole number result, one would want to use the more efficient algorithm.

Secondly, there are a number of algorithms that use integer division, and if the result of division was always a floating point number you would be forced to round the result every time. One example off of the top of my head is changing the base of a number. Calculating each digit involves the integer division of a number along with the remainder, rather than the floating point division of the number.

Because of these (and other related) reasons, integer division results in an integer. If you want to get the floating point division of two integers you'll just need to remember to cast one to a double/float/decimal.

Ordering issue with date values when creating pivot tables

Try creating a new pivot table, and not just refreshing.

I had a case where I forgot to add in a few dates. After adding them in I updated the pivot table range and hit refresh. They appeared at the end of the pivot table, out of order. I then tried to simply create a new pivot table and the dates where all in order.

conflicting types error when compiling c program using gcc

If you don't declare a function and it only appears after being called, it is automatically assumed to be int, so in your case, you didn't declare

void my_print (char *);
void my_print2 (char *);

before you call it in main, so the compiler assume there are functions which their prototypes are int my_print2 (char *); and int my_print2 (char *); and you can't have two functions with the same prototype except of the return type, so you get the error of conflicting types.

As Brian suggested, declare those two methods before main.

How to turn off caching on Firefox?

If you're working with server side code you could generate a random number and append it to the end of the src in the following manner....

src="yourJavascriptFile.js?randomNumber=434534"

with the randomNumber being randomly generated each time.

Jquery open popup on button click for bootstrap

Below mentioned link gives the clear explanation with example.

http://www.aspsnippets.com/Articles/Open-Show-jQuery-UI-Dialog-Modal-Popup-on-Button-Click.aspx

Code from the same link

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<script src="http://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.9/jquery-ui.js" type="text/javascript"></script>
<link href="http://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.9/themes/blitzer/jquery-ui.css"
    rel="stylesheet" type="text/css" />
<script type="text/javascript">
    $(function () {
        $("#dialog").dialog({
            modal: true,
            autoOpen: false,
            title: "jQuery Dialog",
            width: 300,
            height: 150
        });
        $("#btnShow").click(function () {
            $('#dialog').dialog('open');
        });
    });
</script>
<input type="button" id="btnShow" value="Show Popup" />
<div id="dialog" style="display: none" align = "center">
    This is a jQuery Dialog.
</div>

Serializing PHP object to JSON

Try using this, this worked fine for me.

json_encode(unserialize(serialize($array)));

How to pass a PHP variable using the URL

All the above answers are correct, but I noticed something very important. Leaving a space between the variable and the equal sign might result in a problem. For example, (?variablename =value)

Loop inside React JSX

You might want to checkout React Templates, which does let you use JSX-style templates in React, with a few directives (such as rt-repeat).

Your example, if you used react-templates, would be:

<tbody>
     <ObjectRow rt-repeat="obj in objects"/>
</tbody>

Remove warning messages in PHP

If you don't want to show warnings as well as errors use

// Turn off all error reporting
error_reporting(0);

Error Reporting - PHP Manual

Java JDBC - How to connect to Oracle using Service Name instead of SID

So there are two easy ways to make this work. The solution posted by Bert F works fine if you don't need to supply any other special Oracle-specific connection properties. The format for that is:

jdbc:oracle:thin:@//HOSTNAME:PORT/SERVICENAME

However, if you need to supply other Oracle-specific connection properties then you need to use the long TNSNAMES style. I had to do this recently to enable Oracle shared connections (where the server does its own connection pooling). The TNS format is:

jdbc:oracle:thin:@(description=(address=(host=HOSTNAME)(protocol=tcp)(port=PORT))(connect_data=(service_name=SERVICENAME)(server=SHARED)))

If you're familiar with the Oracle TNSNAMES file format, then this should look familiar to you. If not then just Google it for the details.

Unable to send email using Gmail SMTP server through PHPMailer, getting error: SMTP AUTH is required for message submission on port 587. How to fix?

 $mail->SMTPOptions = array(
                'ssl' => array(
                    'verify_peer' => false,
                    'verify_peer_name' => false,
                    'allow_self_signed' => true
                )
            );

Difference between StringBuilder and StringBuffer

StringBuffer is synchronized, StringBuilder is not.

jQuery getTime function

Annoyingly Javascript's date.getSeconds() et al will not pad the result with zeros 11:0:0 instead of 11:00:00.

So I like to use

date.toLocaleTimestring()

Which renders 11:00:00 AM. Just beware when using the extra options, some browsers don't support them (Safari)

Documentation

IE6/IE7 css border on select element

To do a border along one side of a select in IE use IE's filters:

select.required { border-left:2px solid red; filter: progid:DXImageTransform.Microsoft.dropshadow(OffX=-2, OffY=0,color=#FF0000) }

I put a border on one side only of all my inputs for required status.

There is probably an effects that do a better job for an all-round border ...

http://msdn.microsoft.com/en-us/library/ms532853(v=VS.85).aspx

Clicking URLs opens default browser

Official documentation says, click on a link in a WebView will launch application that handles URLs. You need to override this default behavior

    myWebView.setWebViewClient(new WebViewClient() {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            return false;
        }
    });

or if there is no conditional logic in the method simply do this

myWebView.setWebViewClient(new WebViewClient());

How to calculate the IP range when the IP address and the netmask is given?

I would recommend the use of IPNetwork Library https://github.com/lduchosal/ipnetwork. As of version 2, it supports IPv4 and IPv6 as well.

IPv4

  IPNetwork ipnetwork = IPNetwork.Parse("192.168.0.1/25");

  Console.WriteLine("Network : {0}", ipnetwork.Network);
  Console.WriteLine("Netmask : {0}", ipnetwork.Netmask);
  Console.WriteLine("Broadcast : {0}", ipnetwork.Broadcast);
  Console.WriteLine("FirstUsable : {0}", ipnetwork.FirstUsable);
  Console.WriteLine("LastUsable : {0}", ipnetwork.LastUsable);
  Console.WriteLine("Usable : {0}", ipnetwork.Usable);
  Console.WriteLine("Cidr : {0}", ipnetwork.Cidr);

Output

  Network : 192.168.0.0
  Netmask : 255.255.255.128
  Broadcast : 192.168.0.127
  FirstUsable : 192.168.0.1
  LastUsable : 192.168.0.126
  Usable : 126
  Cidr : 25

Have fun !

C++ Compare char array with string

your thinking about this program below

#include <stdio.h>
#include <string.h>

int main ()
{
char str[][5] = { "R2D2" , "C3PO" , "R2A6" };
int n;
puts ("Looking for R2 astromech droids...");
for (n=0 ; n<3 ; n++)
if (strncmp (str[n],"R2xx",2) == 0)
{
  printf ("found %s\n",str[n]);
}
return 0;
}
//outputs:
//
//Looking for R2 astromech droids...
//found R2D2
//found R2A6

when you should be thinking about inputting something into an array & then use strcmp functions like the program above ... check out a modified program below

#include <iostream>
#include<cctype>
#include <string.h>
#include <string>
using namespace std;

int main()
{
int Students=2;
int Projects=3, Avg2=0, Sum2=0, SumT2=0, AvgT2=0, i=0, j=0;
int Grades[Students][Projects];

for(int j=0; j<=Projects-1; j++){
  for(int i=0; i<=Students; i++) {
 cout <<"Please give grade of student "<< j <<"in project "<< i  <<  ":";
  cin >> Grades[j][i];

  }
  Sum2 = Sum2 + Grades[i][j];
     Avg2 = Sum2/Students;
}
SumT2 = SumT2 + Avg2;
AvgT2 = SumT2/Projects;
cout << "avg is  : " << AvgT2 << " and sum : " << SumT2 << ":";
return 0;
}

change to string except it only reads 1 input and throws the rest out maybe need two for loops and two pointers

#include <cstring>
#include <iostream>
#include <string>
#include <stdio.h>
using namespace std;
int main()
{
char name[100];
//string userInput[26];
int i=0, n=0, m=0;
cout<<"your name? ";
cin>>name;
cout<<"Hello "<<name<< endl;

char *ptr=name;
for (i = 0; i < 20; i++)
{
cout<<i<<" "<<ptr[i]<<" "<<(int)ptr[i]<<endl;
}   
int length = 0;
while(name[length] != '\0')
{
length++;
}
                    for(n=0; n<4; n++)
                {
                            if (strncmp(ptr, "snit", 4) == 0)
                            {
            cout << "you found the snitch "    <<        ptr[i];
                            }
                }
cout<<name <<"is"<<length<<"chars long";
}

Group array items using object

One option is:

var res = myArray.reduce(function(groups, currentValue) {
    if ( groups.indexOf(currentValue.group) === -1 ) {
      groups.push(currentValue.group);
    }
    return groups;
}, []).map(function(group) {
    return {
        group: group,
        color: myArray.filter(function(_el) {
          return _el.group === group;
        }).map(function(_el) { return _el.color; })
    }
});

http://jsfiddle.net/dvgwodxq/

ImportError: No module named BeautifulSoup

First install beautiful soup version 4. write command in the terminal window:

pip install beautifulsoup4

then import the BeutifulSoup library

How to select all records from one table that do not exist in another table?

You can either do

SELECT name
FROM table2
WHERE name NOT IN
    (SELECT name 
     FROM table1)

SELECT name 
FROM table2 
WHERE NOT EXISTS 
    (SELECT * 
     FROM table1 
     WHERE table1.name = table2.name)

See this question for 3 techniques to accomplish this

What does a bitwise shift (left or right) do and what is it used for?

Here is an applet where you can exercise some bit-operations, including shifting.

You have a collection of bits, and you move some of them beyond their bounds:

1111 1110 << 2
1111 1000

It is filled from the right with fresh zeros. :)

0001 1111 >> 3
0000 0011

Filled from the left. A special case is the leading 1. It often indicates a negative value - depending on the language and datatype. So often it is wanted, that if you shift right, the first bit stays as it is.

1100 1100 >> 1
1110 0110

And it is conserved over multiple shifts:

1100 1100 >> 2
1111 0011

If you don't want the first bit to be preserved, you use (in Java, Scala, C++, C as far as I know, and maybe more) a triple-sign-operator:

1100 1100 >>> 1
0110 0110

There isn't any equivalent in the other direction, because it doesn't make any sense - maybe in your very special context, but not in general.

Mathematically, a left-shift is a *=2, 2 left-shifts is a *=4 and so on. A right-shift is a /= 2 and so on.

jquery json to string?

The best way I have found is to use jQuery JSON

How do I style appcompat-v7 Toolbar like Theme.AppCompat.Light.DarkActionBar?

Ok after having sunk way to much time into this problem this is the way I managed to get the appearance I was hoping for. I'm making it a separate answer so I can get everything in one place.

It's a combination of factors.

Firstly, don't try to get the toolbars to play nice through just themes. It seems to be impossible.

So apply themes explicitly to your Toolbars like in oRRs answer

layout/toolbar.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_alignParentTop="true"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    app:theme="@style/Dark.Overlay"
    app:popupTheme="@style/Dark.Overlay.LightPopup" />

However this is the magic sauce. In order to actually get the background colors I was hoping for you have to override the background attribute in your Toolbar themes

values/styles.xml:

<!-- 
    I expected android:colorBackground to be what I was looking for but
    it seems you have to override android:background
-->
<style name="Dark.Overlay" parent="@style/ThemeOverlay.AppCompat.Dark.ActionBar">
    <item name="android:background">?attr/colorPrimary</item>
</style>

<style name="Dark.Overlay.LightPopup" parent="ThemeOverlay.AppCompat.Light">
    <item name="android:background">@color/material_grey_200</item>
</style>

then just include your toolbar layout in your other layouts

<include android:id="@+id/mytoolbar" layout="@layout/toolbar" />

and you're good to go.

Hope this helps someone else so you don't have to spend as much time on this as I have.

(if anyone can figure out how to make this work using just themes, ie not having to apply the themes explicitly in the layout files I'll gladly support their answer instead)

EDIT:

So apparently posting a more complete answer was a downvote magnet so I'll just accept the imcomplete answer above but leave this answer here in case someone actually needs it. Feel free to keep downvoting if it makes you happy though.

How to sort a NSArray alphabetically?

This already has good answers for most purposes, but I'll add mine which is more specific.

In English, normally when we alphabetise, we ignore the word "the" at the beginning of a phrase. So "The United States" would be ordered under "U" and not "T".

This does that for you.

It would probably be best to put these in categories.

// Sort an array of NSStrings alphabetically, ignoring the word "the" at the beginning of a string.

-(NSArray*) sortArrayAlphabeticallyIgnoringThes:(NSArray*) unsortedArray {

    NSArray * sortedArray = [unsortedArray sortedArrayUsingComparator:^NSComparisonResult(NSString* a, NSString* b) {

        //find the strings that will actually be compared for alphabetical ordering
        NSString* firstStringToCompare = [self stringByRemovingPrecedingThe:a];
        NSString* secondStringToCompare = [self stringByRemovingPrecedingThe:b];

        return [firstStringToCompare compare:secondStringToCompare];
    }];
    return sortedArray;
}

// Remove "the"s, also removes preceding white spaces that are left as a result. Assumes no preceding whitespaces to start with. nb: Trailing white spaces will be deleted too.

-(NSString*) stringByRemovingPrecedingThe:(NSString*) originalString {
    NSString* result;
    if ([[originalString substringToIndex:3].lowercaseString isEqualToString:@"the"]) {
        result = [[originalString substringFromIndex:3] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
    }
    else {
        result = originalString;
    }
    return result;
}

Multiline for WPF TextBox

The only property corresponding in WPF to the

Winforms property: TextBox.Multiline = true

is the WPF property: TextBox.AcceptsReturn = true.

<TextBox AcceptsReturn="True" ...... />

All other settings, such as VerticalAlignement, WordWrap etc., only control how the TextBox interacts in the UI but do not affect the Multiline behaviour.

jQuery: Count number of list elements?

and of course the following:

var count = $("#myList").children().length;

can be condensed down to: (by removing the 'var' which is not necessary to set a variable)

count = $("#myList").children().length;

however this is cleaner:

count = $("#mylist li").size();

How to build and use Google TensorFlow C++ api

To get started, you should download the source code from Github, by following the instructions here (you'll need Bazel and a recent version of GCC).

The C++ API (and the backend of the system) is in tensorflow/core. Right now, only the C++ Session interface, and the C API are being supported. You can use either of these to execute TensorFlow graphs that have been built using the Python API and serialized to a GraphDef protocol buffer. There is also an experimental feature for building graphs in C++, but this is currently not quite as full-featured as the Python API (e.g. no support for auto-differentiation at present). You can see an example program that builds a small graph in C++ here.

The second part of the C++ API is the API for adding a new OpKernel, which is the class containing implementations of numerical kernels for CPU and GPU. There are numerous examples of how to build these in tensorflow/core/kernels, as well as a tutorial for adding a new op in C++.

SVN upgrade working copy

If you're getting this error from Netbeans (7.2+) then it means that your separately installed version of Subversion is higher than the version in netbeans. In my case Netbeans (v7.3.1) had SVN v1.7 and I'd just upgraded my SVN to v1.8.

If you look in Tools > Options > Miscellaneous (tab) > Versioning (tab) > Subversion (pane), set the Preferred Client = CLI, then you can set the path the the installed SVN which for me was C:\Program Files\TortoiseSVN\bin.

More can be found on the Netbeans Subversion Clients FAQ.

How to calculate distance between two locations using their longitude and latitude value

Try this code.

startPoint.distanceTo(endPoint) function returns the distance between those places in meters.

Location startPoint=new Location("locationA");
startPoint.setLatitude(17.372102);
startPoint.setLongitude(78.484196);

Location endPoint=new Location("locationA");
endPoint.setLatitude(17.375775);
endPoint.setLongitude(78.469218);

double distance=startPoint.distanceTo(endPoint);

here "distance" is our required result in Meters. I hope it will work for android.

What are advantages of Artificial Neural Networks over Support Vector Machines?

One thing to note is that the two are actually very related. Linear SVMs are equivalent to single-layer NN's (i.e., perceptrons), and multi-layer NNs can be expressed in terms of SVMs. See here for some details.

GRANT EXECUTE to all stored procedures

REST API Token-based Authentication

Let me seperate up everything and solve approach each problem in isolation:

Authentication

For authentication, baseauth has the advantage that it is a mature solution on the protocol level. This means a lot of "might crop up later" problems are already solved for you. For example, with BaseAuth, user agents know the password is a password so they don't cache it.

Auth server load

If you dispense a token to the user instead of caching the authentication on your server, you are still doing the same thing: Caching authentication information. The only difference is that you are turning the responsibility for the caching to the user. This seems like unnecessary labor for the user with no gains, so I recommend to handle this transparently on your server as you suggested.

Transmission Security

If can use an SSL connection, that's all there is to it, the connection is secure*. To prevent accidental multiple execution, you can filter multiple urls or ask users to include a random component ("nonce") in the URL.

url = username:[email protected]/api/call/nonce

If that is not possible, and the transmitted information is not secret, I recommend securing the request with a hash, as you suggested in the token approach. Since the hash provides the security, you could instruct your users to provide the hash as the baseauth password. For improved robustness, I recommend using a random string instead of the timestamp as a "nonce" to prevent replay attacks (two legit requests could be made during the same second). Instead of providing seperate "shared secret" and "api key" fields, you can simply use the api key as shared secret, and then use a salt that doesn't change to prevent rainbow table attacks. The username field seems like a good place to put the nonce too, since it is part of the auth. So now you have a clean call like this:

nonce = generate_secure_password(length: 16);
one_time_key = nonce + '-' + sha1(nonce+salt+shared_key);
url = username:[email protected]/api/call

It is true that this is a bit laborious. This is because you aren't using a protocol level solution (like SSL). So it might be a good idea to provide some kind of SDK to users so at least they don't have to go through it themselves. If you need to do it this way, I find the security level appropriate (just-right-kill).

Secure secret storage

It depends who you are trying to thwart. If you are preventing people with access to the user's phone from using your REST service in the user's name, then it would be a good idea to find some kind of keyring API on the target OS and have the SDK (or the implementor) store the key there. If that's not possible, you can at least make it a bit harder to get the secret by encrypting it, and storing the encrypted data and the encryption key in seperate places.

If you are trying to keep other software vendors from getting your API key to prevent the development of alternate clients, only the encrypt-and-store-seperately approach almost works. This is whitebox crypto, and to date, no one has come up with a truly secure solution to problems of this class. The least you can do is still issue a single key for each user so you can ban abused keys.

(*) EDIT: SSL connections should no longer be considered secure without taking additional steps to verify them.

how to send a post request with a web browser

with a form, just set method to "post"

<form action="blah.php" method="post">
  <input type="text" name="data" value="mydata" />
  <input type="submit" />
</form>

How to set time to a date object in java

Can you show code which you use for setting date object? Anyway< you can use this code for intialisation of date:

new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").parse("2011-01-01 00:00:00")

Maven error "Failure to transfer..."

for mac

I removed all the old failed downloads of maven there were several versions of maven also on my mac

find ~/.m2 -name "*.lastUpdated" -exec grep -q "Could not transfer" {} ; -print -exec rm {} ;

after that, I simply updated my eclipse by

help -> check for updates

and the problem resolved for me

the main reason for this problem is the failed old updates does not allow you to download archetype so if you try to build project in any archetype of maven it gets failed

CSS: create white glow around image

Use simple CSS3 (not supported in IE<9)

img
{
    box-shadow: 0px 0px 5px #fff;
}

This will put a white glow around every image in your document, use more specific selectors to choose which images you'd like the glow around. You can change the color of course :)

If you're worried about the users that don't have the latest versions of their browsers, use this:

img
{
-moz-box-shadow: 0 0 5px #fff;
-webkit-box-shadow: 0 0 5px #fff;
box-shadow: 0px 0px 5px #fff;
}

For IE you can use a glow filter (not sure which browsers support it)

img
{
    filter:progid:DXImageTransform.Microsoft.Glow(Color=white,Strength=5);
}

Play with the settings to see what suits you :)

How to convert a timezone aware string to datetime in Python without dateutil?

As of Python 3.7, datetime.datetime.fromisoformat() can handle your format:

>>> import datetime
>>> datetime.datetime.fromisoformat('2012-11-01T04:16:13-04:00')
datetime.datetime(2012, 11, 1, 4, 16, 13, tzinfo=datetime.timezone(datetime.timedelta(days=-1, seconds=72000)))

In older Python versions you can't, not without a whole lot of painstaking manual timezone defining.

Python does not include a timezone database, because it would be outdated too quickly. Instead, Python relies on external libraries, which can have a far faster release cycle, to provide properly configured timezones for you.

As a side-effect, this means that timezone parsing also needs to be an external library. If dateutil is too heavy-weight for you, use iso8601 instead, it'll parse your specific format just fine:

>>> import iso8601
>>> iso8601.parse_date('2012-11-01T04:16:13-04:00')
datetime.datetime(2012, 11, 1, 4, 16, 13, tzinfo=<FixedOffset '-04:00'>)

iso8601 is a whopping 4KB small. Compare that tot python-dateutil's 148KB.

As of Python 3.2 Python can handle simple offset-based timezones, and %z will parse -hhmm and +hhmm timezone offsets in a timestamp. That means that for a ISO 8601 timestamp you'd have to remove the : in the timezone:

>>> from datetime import datetime
>>> iso_ts = '2012-11-01T04:16:13-04:00'
>>> datetime.strptime(''.join(iso_ts.rsplit(':', 1)), '%Y-%m-%dT%H:%M:%S%z')
datetime.datetime(2012, 11, 1, 4, 16, 13, tzinfo=datetime.timezone(datetime.timedelta(-1, 72000)))

The lack of proper ISO 8601 parsing is being tracked in Python issue 15873.

What's the difference between Git Revert, Checkout and Reset?

git revert is used to undo a previous commit. In git, you can't alter or erase an earlier commit. (Actually you can, but it can cause problems.) So instead of editing the earlier commit, revert introduces a new commit that reverses an earlier one.
git reset is used to undo changes in your working directory that haven't been comitted yet.
git checkout is used to copy a file from some other commit to your current working tree. It doesn't automatically commit the file.

Update index after sorting data-frame

df.sort() is deprecated, use df.sort_values(...): https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.sort_values.html

Then follow joris' answer by doing df.reset_index(drop=True)

How to change date format (MM/DD/YY) to (YYYY-MM-DD) in date picker

Use the dateFormat option

 $(function(){
        $("#to").datepicker({ dateFormat: 'yy-mm-dd' });
        $("#from").datepicker({ dateFormat: 'yy-mm-dd' }).bind("change",function(){
            var minValue = $(this).val();
            minValue = $.datepicker.parseDate("yy-mm-dd", minValue);
            minValue.setDate(minValue.getDate()+1);
            $("#to").datepicker( "option", "minDate", minValue );
        })
    });

Demo at http://jsfiddle.net/gaby/WArtA/

How can I trigger another job from a jenkins pipeline (jenkinsfile) with GitHub Org Plugin?

You can use the build job step from Jenkins Pipeline (Minimum Jenkins requirement: 2.130).

Here's the full API for the build step: https://jenkins.io/doc/pipeline/steps/pipeline-build-step/

How to use build:

job: Name of a downstream job to build. May be another Pipeline job, but more commonly a freestyle or other project.
- Use a simple name if the job is in the same folder as this upstream Pipeline job;
- You can instead use relative paths like ../sister-folder/downstream
- Or you can use absolute paths like /top-level-folder/nested-folder/downstream

Trigger another job using a branch as a param

At my company many of our branches include "/". You must replace any instances of "/" with "%2F" (as it appears in the URL of the job).

In this example we're using relative paths

    stage('Trigger Branch Build') {
        steps {
            script {
                    echo "Triggering job for branch ${env.BRANCH_NAME}"
                    BRANCH_TO_TAG=env.BRANCH_NAME.replace("/","%2F")
                    build job: "../my-relative-job/${BRANCH_TO_TAG}", wait: false
            }
        }
    }

Trigger another job using build number as a param

build job: 'your-job-name', 
    parameters: [
        string(name: 'passed_build_number_param', value: String.valueOf(BUILD_NUMBER)),
        string(name: 'complex_param', value: 'prefix-' + String.valueOf(BUILD_NUMBER))
    ]

Trigger many jobs in parallel

Source: https://jenkins.io/blog/2017/01/19/converting-conditional-to-pipeline/

More info on Parallel here: https://jenkins.io/doc/book/pipeline/syntax/#parallel

    stage ('Trigger Builds In Parallel') {
        steps {
            // Freestyle build trigger calls a list of jobs
            // Pipeline build() step only calls one job
            // To run all three jobs in parallel, we use "parallel" step
            // https://jenkins.io/doc/pipeline/examples/#jobs-in-parallel
            parallel (
                linux: {
                    build job: 'full-build-linux', parameters: [string(name: 'GIT_BRANCH_NAME', value: env.BRANCH_NAME)]
                },
                mac: {
                    build job: 'full-build-mac', parameters: [string(name: 'GIT_BRANCH_NAME', value: env.BRANCH_NAME)]
                },
                windows: {
                    build job: 'full-build-windows', parameters: [string(name: 'GIT_BRANCH_NAME', value: env.BRANCH_NAME)]
                },
                failFast: false)
        }
    }

Or alternatively:

    stage('Build A and B') {
            failFast true
            parallel {
                stage('Build A') {
                    steps {
                            build job: "/project/A/${env.BRANCH}", wait: true
                    }
                }
                stage('Build B') {
                    steps {
                            build job: "/project/B/${env.BRANCH}", wait: true
                    }
                }
            }
    }

Equivalent of Math.Min & Math.Max for Dates?

Now that we have LINQ, you can create an array with your two values (DateTimes, TimeSpans, whatever) and then use the .Max() extension method.

var values = new[] { Date1, Date2 }; 
var max = values.Max();

It reads nice, it's as efficient as Max can be, and it's reusable for more than 2 values of comparison.

The whole problem below worrying about .Kind is a big deal... but I avoid that by never working in local times, ever. If I have something important regarding times, I always work in UTC, even if it means more work to get there.

What is the difference between attribute and property?

<property attribute="attributeValue">proopertyValue</property>

would be one way to look at it.

In C#

[Attribute]
public class Entity
{
    private int Property{get; set;};

How to get the server path to the web directory in Symfony2 from inside the controller?

There's actually no direct way to get path to webdir in Symfony2 as the framework is completely independent of the webdir.

You can use getRootDir() on instance of kernel class, just as you write. If you consider renaming /web dir in future, you should make it configurable. For example AsseticBundle has such an option in its DI configuration (see here and here).

How can I remove item from querystring in asp.net using c#?

If it's the HttpRequest.QueryString then you can copy the collection into a writable collection and have your way with it.

NameValueCollection filtered = new NameValueCollection(request.QueryString);
filtered.Remove("Language");

Access denied for user 'root'@'localhost' with PHPMyAdmin

Edit your phpmyadmin config.inc.php file and if you have Password, insert that in front of Password in following code:

$cfg['Servers'][$i]['verbose'] = 'localhost';
$cfg['Servers'][$i]['host'] = 'localhost';
$cfg['Servers'][$i]['port'] = '3306';
$cfg['Servers'][$i]['socket'] = '';
$cfg['Servers'][$i]['connect_type'] = 'tcp';
$cfg['Servers'][$i]['extension'] = 'mysqli';
$cfg['Servers'][$i]['auth_type'] = 'config';
$cfg['Servers'][$i]['user'] = '**your-root-username**';
$cfg['Servers'][$i]['password'] = '**root-password**';
$cfg['Servers'][$i]['AllowNoPassword'] = true;

How do I lock the orientation to portrait mode in a iPhone Web Application?

I came up with this CSS only method of rotating the screen using media queries. The queries are based on screen sizes that I found here. 480px seemed to be a good as no/few devices had more than 480px width or less than 480px height.

@media (max-height: 480px) and (min-width: 480px) and (max-width: 600px) { 
    html{
        -webkit-transform: rotate(-90deg);
           -moz-transform: rotate(-90deg);
            -ms-transform: rotate(-90deg);
             -o-transform: rotate(-90deg);
                transform: rotate(-90deg);
        -webkit-transform-origin: left top;
           -moz-transform-origin: left top;
            -ms-transform-origin: left top;
             -o-transform-origin: left top;
                transform-origin: left top;
        width: 320px; /*this is the iPhone screen width.*/
        position: absolute;
        top: 100%;
            left: 0
    }
}

How to Retrieve value from JTextField in Java Swing?

What I found helpful is this condition that is below.

String tempEmail = "";
JTextField tf1 = new JTextField();

tf1.addKeyListener(new KeyAdapter(){
    public void keyTyped(KeyEvent evt){
         tempEmail = ((JTextField)evt.getSource()).getText() + String.valueOf(evt.getKeyChar());
    }
});

Typescript export vs. default export

Named export

In TS you can export with the export keyword. It then can be imported via import {name} from "./mydir";. This is called a named export. A file can export multiple named exports. Also the names of the imports have to match the exports. For example:

// foo.js file
export class foo{}
export class bar{}

// main.js file in same dir
import {foo, bar} from "./foo";

The following alternative syntax is also valid:

// foo.js file
function foo() {};
function bar() {};
export {foo, bar};

// main.js file in same dir
import {foo, bar} from './foo'

Default export

We can also use a default export. There can only be one default export per file. When importing a default export we omit the square brackets in the import statement. We can also choose our own name for our import.

// foo.js file
export default class foo{}

// main.js file in same directory
import abc from "./foo";

It's just JavaScript

Modules and their associated keyword like import, export, and export default are JavaScript constructs, not typescript. However typescript added the exporting and importing of interfaces and type aliases to it.

Instance member cannot be used on type

I kept getting the same error inspite of making the variable static. Solution: Clean Build, Clean Derived Data, Restart Xcode. Or shortcut Cmd + Shift+Alt+K

UserNotificationCenterWrapper.delegate = self

public static var delegate: UNUserNotificationCenterDelegate? {
        get {
            return UNUserNotificationCenter.current().delegate
        }
        set {
            UNUserNotificationCenter.current().delegate = newValue
        }
    }

ElasticSearch - Return Unique Values

You can use the terms aggregation.

{
"size": 0,
"aggs" : {
    "langs" : {
        "terms" : { "field" : "language",  "size" : 500 }
    }
}}

The size parameter within the aggregation specifies the maximum number of terms to include in the aggregation result. If you need all results, set this to a value that is larger than the number of unique terms in your data.

A search will return something like:

{
"took" : 16,
"timed_out" : false,
"_shards" : {
  "total" : 2,
  "successful" : 2,
  "failed" : 0
},
"hits" : {
"total" : 1000000,
"max_score" : 0.0,
"hits" : [ ]
},
"aggregations" : {
  "langs" : {
    "buckets" : [ {
      "key" : "10",
      "doc_count" : 244812
    }, {
      "key" : "11",
      "doc_count" : 136794
 
    }, {
      "key" : "12",
      "doc_count" : 32312
       } ]
    }
  }
}

Razor Views not seeing System.Web.Mvc.HtmlHelper

I had the same issue when updating to MVC 5 and it was solved by updating the web.config inside the Views folder.

<system.web.webPages.razor>
<host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
<pages pageBaseType="System.Web.Mvc.WebViewPage">
  <namespaces>
    <add namespace="System.Web.Mvc" />
    <add namespace="System.Web.Mvc.Ajax" />
    <add namespace="System.Web.Mvc.Html" />
    <add namespace="System.Web.Optimization"/>
    <add namespace="System.Web.Routing" />
  </namespaces>
</pages>

The host -> factoryType was set to version:4.0.0.0 hope this helps anyone.

How can I decode HTML characters in C#?

For strings containing   I've had to double-decode the string. First decode would turn it into the second pass would correctly decode it to the expected character.

Find index of a value in an array

Just posted my implementation of IndexWhere() extension method (with unit tests):

http://snipplr.com/view/53625/linq-index-of-item--indexwhere/

Example usage:

int index = myList.IndexWhere(item => item.Something == someOtherThing);

How to hash a string into 8 digits?

Yes, you can use the built-in hashlib module or the built-in hash function. Then, chop-off the last eight digits using modulo operations or string slicing operations on the integer form of the hash:

>>> s = 'she sells sea shells by the sea shore'

>>> # Use hashlib
>>> import hashlib
>>> int(hashlib.sha1(s.encode("utf-8")).hexdigest(), 16) % (10 ** 8)
58097614L

>>> # Use hash()
>>> abs(hash(s)) % (10 ** 8)
82148974

Create a <ul> and fill it based on a passed array

What are disadvantages of the following solution? Seems to be faster and shorter.

var options = {
    set0: ['Option 1','Option 2'],
    set1: ['First Option','Second Option','Third Option']
};

var list = "<li>" + options.set0.join("</li><li>") + "</li>";
document.getElementById("list").innerHTML = list;

Difference between volatile and synchronized in Java

It's important to understand that there are two aspects to thread safety.

execution control, and
memory visibility

The first has to do with controlling when code executes (including the order in which instructions are executed) and whether it can execute concurrently, and the second to do with when the effects in memory of what has been done are visible to other threads. Because each CPU has several levels of cache between it and main memory, threads running on different CPUs or cores can see "memory" differently at any given moment in time because threads are permitted to obtain and work on private copies of main memory.

Using synchronized prevents any other thread from obtaining the monitor (or lock) for the same object, thereby preventing all code blocks protected by synchronization on the same object from executing concurrently. Synchronization also creates a "happens-before" memory barrier, causing a memory visibility constraint such that anything done up to the point some thread releases a lock appears to another thread subsequently acquiring the same lock to have happened before it acquired the lock. In practical terms, on current hardware, this typically causes flushing of the CPU caches when a monitor is acquired and writes to main memory when it is released, both of which are (relatively) expensive.

Using volatile, on the other hand, forces all accesses (read or write) to the volatile variable to occur to main memory, effectively keeping the volatile variable out of CPU caches. This can be useful for some actions where it is simply required that visibility of the variable be correct and order of accesses is not important. Using volatile also changes treatment of long and double to require accesses to them to be atomic; on some (older) hardware this might require locks, though not on modern 64 bit hardware. Under the new (JSR-133) memory model for Java 5+, the semantics of volatile have been strengthened to be almost as strong as synchronized with respect to memory visibility and instruction ordering (see http://www.cs.umd.edu/users/pugh/java/memoryModel/jsr-133-faq.html#volatile). For the purposes of visibility, each access to a volatile field acts like half a synchronization.

Under the new memory model, it is still true that volatile variables cannot be reordered with each other. The difference is that it is now no longer so easy to reorder normal field accesses around them. Writing to a volatile field has the same memory effect as a monitor release, and reading from a volatile field has the same memory effect as a monitor acquire. In effect, because the new memory model places stricter constraints on reordering of volatile field accesses with other field accesses, volatile or not, anything that was visible to thread A when it writes to volatile field f becomes visible to thread B when it reads f.

-- JSR 133 (Java Memory Model) FAQ

So, now both forms of memory barrier (under the current JMM) cause an instruction re-ordering barrier which prevents the compiler or run-time from re-ordering instructions across the barrier. In the old JMM, volatile did not prevent re-ordering. This can be important, because apart from memory barriers the only limitation imposed is that, for any particular thread, the net effect of the code is the same as it would be if the instructions were executed in precisely the order in which they appear in the source.

One use of volatile is for a shared but immutable object is recreated on the fly, with many other threads taking a reference to the object at a particular point in their execution cycle. One needs the other threads to begin using the recreated object once it is published, but does not need the additional overhead of full synchronization and it's attendant contention and cache flushing.

// Declaration
public class SharedLocation {
    static public SomeObject someObject=new SomeObject(); // default object
    }

// Publishing code
// Note: do not simply use SharedLocation.someObject.xxx(), since although
//       someObject will be internally consistent for xxx(), a subsequent 
//       call to yyy() might be inconsistent with xxx() if the object was 
//       replaced in between calls.
SharedLocation.someObject=new SomeObject(...); // new object is published

// Using code
private String getError() {
    SomeObject myCopy=SharedLocation.someObject; // gets current copy
    ...
    int cod=myCopy.getErrorCode();
    String txt=myCopy.getErrorText();
    return (cod+" - "+txt);
    }
// And so on, with myCopy always in a consistent state within and across calls
// Eventually we will return to the code that gets the current SomeObject.

Speaking to your read-update-write question, specifically. Consider the following unsafe code:

public void updateCounter() {
    if(counter==1000) { counter=0; }
    else              { counter++; }
    }

Now, with the updateCounter() method unsynchronized, two threads may enter it at the same time. Among the many permutations of what could happen, one is that thread-1 does the test for counter==1000 and finds it true and is then suspended. Then thread-2 does the same test and also sees it true and is suspended. Then thread-1 resumes and sets counter to 0. Then thread-2 resumes and again sets counter to 0 because it missed the update from thread-1. This can also happen even if thread switching does not occur as I have described, but simply because two different cached copies of counter were present in two different CPU cores and the threads each ran on a separate core. For that matter, one thread could have counter at one value and the other could have counter at some entirely different value just because of caching.

What's important in this example is that the variable counter was read from main memory into cache, updated in cache and only written back to main memory at some indeterminate point later when a memory barrier occurred or when the cache memory was needed for something else. Making the counter volatile is insufficient for thread-safety of this code, because the test for the maximum and the assignments are discrete operations, including the increment which is a set of non-atomic read+increment+write machine instructions, something like:

MOV EAX,counter
INC EAX
MOV counter,EAX

Volatile variables are useful only when all operations performed on them are "atomic", such as my example where a reference to a fully formed object is only read or written (and, indeed, typically it's only written from a single point). Another example would be a volatile array reference backing a copy-on-write list, provided the array was only read by first taking a local copy of the reference to it.

jQuery / Javascript code check, if not undefined

I like this:

if (wlocation !== undefined)

But if you prefer the second way wouldn't be as you posted. It would be:

if (typeof wlocation  !== "undefined")

Avoiding NullPointerException in Java

I follow below guidelines to avoid null checks.

Avoid lazy initialization of member variables as much as possible. Initialize the variables in declaration itself. This will handle NullPointerExceptions.
Decide on mutability of member variables early in the cycle. Use language constructs like final keyword effectively.
If you know that augments for method won't be changed, declare them as final.
Limit the mutation of data as much as possible. Some variables can be created in a constructor and can never be changed. Remove public setter methods unless they are really required.

E.g. Assume that one class in your application (A.java) is maintaining a collection like HashMap. Don't provide public getter method in A.java and allow B.java to directly add an element in Map. Instead provide an API in A.java, which adds an element into collection.
```
// Avoid
a.getMap().put(key,value)

//recommended

public void addElement(Object key, Object value){
       // Have null checks for both key and value here : single place
       map.put(key,value);
}
```
And finally, use try{} catch{} finally{} blocks at right places effectively.

Docker container not starting (docker start)

What I need is to use Docker with MariaDb on different port /3301/ on my Ubuntu machine because I already had MySql installed and running on 3306.

To do this after half day searching did it using:

docker run -it -d -p 3301:3306 -v ~/mdbdata/mariaDb:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=root --name mariaDb mariadb

This pulls the image with latest MariaDb, creates container called mariaDb, and run mysql on port 3301. All data of which is located in home directory in /mdbdata/mariaDb.

To login in mysql after that can use:

mysql -u root -proot -h 127.0.0.1 -P3301

Used sources are:

The answer of Iarks in this article /using -it -d was the key :) /

how-to-install-and-use-docker-on-ubuntu-16-04

installing-and-using-mariadb-via-docker

mariadb-and-docker-use-cases-part-1

Good luck all!

how to inherit Constructor from super class to sub class

Read about the super keyword (Scroll down the Subclass Constructors). If I understand your question, you probably want to call a superclass constructor?

It is worth noting that the Java compiler will automatically put in a no-arg constructor call to the superclass if you do not explicitly invoke a superclass constructor.

How to convert date format to DD-MM-YYYY in C#

I ran into the same issue. What I needed to do was add a reference at the top of the class and change the CultureInfo of the thread that is currently executing.

using System.Threading;

string cultureName = "fr-CA";
Thread.CurrentThread.CurrentCulture = new CultureInfo(cultureName);

DateTime theDate = new DateTime(2015, 11, 06);
theDate.ToString("g");
Console.WriteLine(theDate);

All you have to do is change the culture name, for example: "en-US" = United States "fr-FR" = French-speaking France "fr-CA" = French-speaking Canada etc...

How much should a function trust another function

The addEdge is trusting more than the correction of the addNode method. It's also trusting that the addNode method has been invoked by other method. I'd recommend to include check if m is not null.

How to change the playing speed of videos in HTML5?

According to this site, this is supported in the playbackRate and defaultPlaybackRate attributes, accessible via the DOM. Example:

/* play video twice as fast */
document.querySelector('video').defaultPlaybackRate = 2.0;
document.querySelector('video').play();

/* now play three times as fast just for the heck of it */
document.querySelector('video').playbackRate = 3.0;

The above works on Chrome 43+, Firefox 20+, IE 9+, Edge 12+.

Passing array in GET for a REST call

/appointments?users=1d1,1d2..

is fine. It's pretty much your only sensible option since you can't pass in a body with a GET.

Android: How to add R.raw to project?

(With reference to Android Studio)

Create a new directory in res folder. Make sure to create new "Android Resource Directory" and not new "Directory".

Then ensure that there is at least one valid file in it. It should show up now.

How to place a JButton at a desired location in a JFrame using Java

You should set layout first by syntax pnlButton.setLayout(), and then choose the most suitable layout which u want. Ex: pnlButton.setLayout(new FlowLayout(FlowLayout.LEADING, 5, 5));. And then, take that JButton into JPanel.

How should I multiple insert multiple records?

static void InsertSettings(IEnumerable<Entry> settings) {
    using (SqlConnection oConnection = new SqlConnection("Data Source=(local);Initial Catalog=Wip;Integrated Security=True")) {
        oConnection.Open();
        using (SqlTransaction oTransaction = oConnection.BeginTransaction()) {
            using (SqlCommand oCommand = oConnection.CreateCommand()) {
                oCommand.Transaction = oTransaction;
                oCommand.CommandType = CommandType.Text;
                oCommand.CommandText = "INSERT INTO [Setting] ([Key], [Value]) VALUES (@key, @value);";
                oCommand.Parameters.Add(new SqlParameter("@key", SqlDbType.NChar));
                oCommand.Parameters.Add(new SqlParameter("@value", SqlDbType.NChar));
                try {
                    foreach (var oSetting in settings) {
                        oCommand.Parameters[0].Value = oSetting.Key;
                        oCommand.Parameters[1].Value = oSetting.Value;
                        if (oCommand.ExecuteNonQuery() != 1) {
                            //'handled as needed, 
                            //' but this snippet will throw an exception to force a rollback
                            throw new InvalidProgramException();
                        }
                    }
                    oTransaction.Commit();
                } catch (Exception) {
                    oTransaction.Rollback();
                    throw;
                }
            }
        }
    }
}

What's a good IDE for Python on Mac OS X?

macvim + pyflakes.vim

How do I list one filename per output line in Linux?

You can also use ls -w1

This allows to set number of columns. From manpage of ls:

   -w, --width=COLS
          set output width to COLS.  0 means no limit

How can I check if a View exists in a Database?

if it's Oracle you would use the "all_views" table.

It really depends on your dbms.

FATAL ERROR in native method: JDWP No transports initialized, jvmtiError=AGENT_ERROR_TRANSPORT_INIT(197)

if your JVM Cli is: -agentlib:jdwp=transport=dt_socket,address=60000,server=n,suspend=n and JDK version is 7, change "server=n" to "server=y" will be OK.

Query to list all stored procedures

This will returned all sp name

Select * 
FROM sys.procedures where [type] = 'P' 
     AND is_ms_shipped = 0 
     AND [name] not like 'sp[_]%diagram%'

Compile error: package javax.servlet does not exist

Copy the file "servlet-api.jar" from location YOUR_INSTILLATION_PATH\tomcat\lib\servlet-api.jar and Paste the file into your Java Directory YOUR_INSTILLATION_PATH\Java\jdk1.8.0_121\jre\lib\ext

this will work (tested).

SCRIPT7002: XMLHttpRequest: Network Error 0x2ef3, Could not complete the operation due to error 00002ef3

With the Apache 2 change KeepAliveTimeout set it to 60 or above

How To Check If A Key in **kwargs Exists?

DSM's and Tadeck's answers answer your question directly.

In my scripts I often use the convenient dict.pop() to deal with optional, and additional arguments. Here's an example of a simple print() wrapper:

def my_print(*args, **kwargs):
    prefix = kwargs.pop('prefix', '')
    print(prefix, *args, **kwargs)

Then:

>>> my_print('eggs')
 eggs
>>> my_print('eggs', prefix='spam')
spam eggs

As you can see, if prefix is not contained in kwargs, then the default '' (empty string) is being stored in the local prefix variable. If it is given, then its value is being used.

This is generally a compact and readable recipe for writing wrappers for any kind of function: Always just pass-through arguments you don't understand, and don't even know if they exist. If you always pass through *args and **kwargs you make your code slower, and requires a bit more typing, but if interfaces of the called function (in this case print) changes, you don't need to change your code. This approach reduces development time while supporting all interface changes.

How to parse the AndroidManifest.xml file inside an .apk package

With the latest SDK-Tools, you can now use a tool called the apkanalyzer to print out the AndroidManifest.xml of an APK (as well as other parts, such as resources).

[android sdk]/tools/bin/apkanalyzer manifest print [app.apk]

apkanalyzer

How to add a line to a multiline TextBox?

You have to use the AppendText method of the textbox directly. If you try to use the Text property, the textbox will not scroll down as new line are appended.

textBox1.AppendText("Hello" + Environment.NewLine);

Custom HTTP headers : naming conventions

Modifying, or more correctly, adding additional HTTP headers is a great code debugging tool if nothing else.

When a URL request returns a redirect or an image there is no html "page" to temporarily write the results of debug code to - at least not one that is visible in a browser.

One approach is to write the data to a local log file and view that file later. Another is to temporarily add HTTP headers reflecting the data and variables being debugged.

I regularly add extra HTTP headers like X-fubar-somevar: or X-testing-someresult: to test things out - and have found a lot of bugs that would have otherwise been very difficult to trace.

Random String Generator Returning Same String

This is my solution:

private string RandomString(int length)
{
    char[] symbols = { 
                            '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                            'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
                            'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'                             
                        };

    Stack<byte> bytes = new Stack<byte>();
    string output = string.Empty;

    for (int i = 0; i < length; i++)
    {
        if (bytes.Count == 0)
        {
            bytes = new Stack<byte>(Guid.NewGuid().ToByteArray());
        }
        byte pop = bytes.Pop();
        output += symbols[(int)pop % symbols.Length];
    }
    return output;
}

// get 1st random string 
string Rand1 = RandomString(4);

// get 2nd random string 
string Rand2 = RandomString(4);

// create full rand string
string docNum = Rand1 + "-" + Rand2;

how to parse JSONArray in android

getJSONArray(attrname) will get you an array from the object of that given attribute name in your case what is happening is that for

{"abridged_cast":["name": blah...]}
^ its trying to search for a value "characters"

but you need to get into the array and then do a search for "characters"

try this

String json="{'abridged_cast':[{'name':'JeffBridges','id':'162655890','characters':['JackPrescott']},{'name':'CharlesGrodin','id':'162662571','characters':['FredWilson']},{'name':'JessicaLange','id':'162653068','characters':['Dwan']},{'name':'JohnRandolph','id':'162691889','characters':['Capt.Ross']},{'name':'ReneAuberjonois','id':'162718328','characters':['Bagley']}]}";

    JSONObject jsonResponse;
    try {
        ArrayList<String> temp = new ArrayList<String>();
        jsonResponse = new JSONObject(json);
        JSONArray movies = jsonResponse.getJSONArray("abridged_cast");
        for(int i=0;i<movies.length();i++){
            JSONObject movie = movies.getJSONObject(i);
            JSONArray characters = movie.getJSONArray("characters");
            for(int j=0;j<characters.length();j++){
                temp.add(characters.getString(j));
            }
        }
        Toast.makeText(this, "Json: "+temp, Toast.LENGTH_LONG).show();
    } catch (JSONException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

checked it :)

This could be due to the service endpoint binding not using the HTTP protocol

Also had this issue and it was due to forgetting to decorate my model with DataContract and DataMember attributes

How do I convert a TimeSpan to a formatted string?

Thanks to Peter for the extension method. I modified it to work with longer time spans better:

namespace ExtensionMethods
{
    public static class TimeSpanExtensionMethods
    {
        public static string ToReadableString(this TimeSpan span)
        {
            string formatted = string.Format("{0}{1}{2}",
                (span.Days / 7) > 0 ? string.Format("{0:0} weeks, ", span.Days / 7) : string.Empty,
                span.Days % 7 > 0 ? string.Format("{0:0} days, ", span.Days % 7) : string.Empty,
                span.Hours > 0 ? string.Format("{0:0} hours, ", span.Hours) : string.Empty);

            if (formatted.EndsWith(", ")) formatted = formatted.Substring(0, formatted.Length - 2);

            return formatted;
        }
    }
}

ESLint not working in VS Code?

General issues

Open the terminal Ctrl+`

Under output ESLint dropdown, you find useful debugging data (Errors, warnings, info).

For example, missing .eslintrc-.json throw this error:

Error: ENOENT: no such file or directory, realpath

Next, check if the plugin enabled:

Last, Since v 2.0.4 - eslint.validate in normal cases not necessary anymore (old legacy setting):

eslint.probe = an array for language identifiers for which the ESLint extension should be activated and should try to validate the file. If validation fails for probed languages the extension says silent. Defaults to [javascript, javascriptreact, typescript, typescriptreact, html, vue, markdown].

Specific Issue - First-time plugin instalation

My issue was related to the ESLint plugin "currently block" status bar on New/First instalation (v2.1.14).

Since ESLint plugin Version 2.1.10 (08/10/2020)

no modal dialog is shown when the ESLint extension tries to load an ESLint library for the first time and an approval is necessary. Instead the ESLint status bar item changes to ESLint status icon indicating that the execution is currently block.

Click on the status-bar (Right-Bottom corner):

Opens this popup:

Approve ==> Allows Everywhere

-or- by commands:

ctrl + Shift + p -- ESLint: Manage Library Execution

Read more here under "Release Notes":

https://marketplace.visualstudio.com/items?itemName=dbaeumer.vscode-eslint

How to make a GUI for bash scripts?

there is a command called dialog which uses the ncurses library. "Dialog is a program that will let you to present a variety of questions or display messages using dialog boxes from a shell script. These types of dialog boxes are implemented (though not all are necessarily compiled into dialog)"

see http://pwet.fr/man/linux/commandes/dialog

Convert UTC datetime string to local datetime

If using Django, you can use the timezone.localtime method:

from django.utils import timezone
date 
# datetime.datetime(2014, 8, 1, 20, 15, 0, 513000, tzinfo=<UTC>)

timezone.localtime(date)
# datetime.datetime(2014, 8, 1, 16, 15, 0, 513000, tzinfo=<DstTzInfo 'America/New_York' EDT-1 day, 20:00:00 DST>)

Which @NotNull Java annotation should I use?

According to the Java 7 features list JSR-308 type annotations are deferred to Java 8. JSR-305 annotations are not even mentioned.

There is a bit of info on the state of JSR-305 in an appendix of the latest JSR-308 draft. This includes the observation that JSR-305 annotations seem to be abandoned. The JSR-305 page also shows it as "inactive".

In the mean time, the pragmatic answer is to use the annotation types that are supported by the most widely used tools ... and be prepared to change them if the situation changes.

In fact, JSR-308 does not define any annotation types/classes, and it looks like they think it is out of scope. (And they are right, given the existence of JSR-305).

However, if JSR-308 really looks like making it into Java 8, it wouldn't surprise me if interest in JSR-305 revived. AFAIK, the JSR-305 team hasn't formally abandoned their work. They have just been quiet for 2+ years.

It is interesting that Bill Pugh (the tech lead for JSR-305) is one of the guy behind FindBugs.

How to create and write to a txt file using VBA

Open ThisWorkbook.Path & "\template.txt" For Output As #1
Print #1, strContent
Close #1

More Information:

Microsoft Docs : Open statement
Microsoft Docs : Print # statement
Microsoft Docs : Close statement
wellsr.com : VBA write to text file with Print Statement
Office Support : Workbook.Path property

how to check if input field is empty

Why don't u use:

<script>
$('input').keyup(function(){
if(($('#eng').val().length > 0) && ($('#spa').val().length > 0))
    $("#submit").prop('disabled', false);
else
    $("#submit").prop('disabled', true);
});
</script>

Then delete the onkeyup function on the input.

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

In Jenkins, how to checkout a project into a specific directory (using GIT)

Find repoName from the url, and then checkout to the specified directory.

String url = 'https://github.com/foo/bar.git';
String[] res = url.split('/');
String repoName = res[res.length-1];
if (repoName.endsWith('.git')) repoName=repoName.substring(0, repoName.length()-4);

checkout([
  $class: 'GitSCM', 
  branches: [[name: 'refs/heads/'+env.BRANCH_NAME]],
  doGenerateSubmoduleConfigurations: false,
  extensions: [
    [$class: 'RelativeTargetDirectory', relativeTargetDir: repoName],
    [$class: 'GitLFSPull'],
    [$class: 'CheckoutOption', timeout: 20],
    [$class: 'CloneOption',
        depth: 3,
        noTags: false,
        reference: '/other/optional/local/reference/clone',
        shallow: true,
        timeout: 120],
    [$class: 'SubmoduleOption', depth: 5, disableSubmodules: false, parentCredentials: true, recursiveSubmodules: true, reference: '', shallow: true, trackingSubmodules: true]
  ],
  submoduleCfg: [],
  userRemoteConfigs: [
    [credentialsId: 'foobar',
    url: url]
  ]
])

Amazon S3 and Cloudfront cache, how to clear cache or synchronize their cache

Use Invalidations to clear the cache, you can put the path to the files you want to clear, or simply use wild cards to clear everything.

http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/Invalidation.html#invalidating-objects-api

This can also be done using the API! http://docs.aws.amazon.com/cloudfront/latest/APIReference/API_CreateInvalidation.html

The AWS PHP SDK now has the methods but if you want to use something lighter check out this library: http://www.subchild.com/2010/09/17/amazon-cloudfront-php-invalidator/

user3305600's solution doesn't work as setting it to zero is the equivalent of Using the Origin Cache Headers.

Save file/open file dialog box, using Swing & Netbeans GUI editor

I have created a sample UI which shows the save and open file dialog. Click on save button to open save dialog and click on open button to open file dialog.

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;

public class FileChooserEx {
    public static void main(String[] args) {
        Runnable r = new Runnable() {

            @Override
            public void run() {
                new FileChooserEx().createUI();
            }
        };

        EventQueue.invokeLater(r);
    }

    private void createUI() {
        JFrame frame = new JFrame();
        frame.setLayout(new BorderLayout());

        JButton saveBtn = new JButton("Save");
        JButton openBtn = new JButton("Open");

        saveBtn.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {
                JFileChooser saveFile = new JFileChooser();
                saveFile.showSaveDialog(null);
            }
        });

        openBtn.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {
                JFileChooser openFile = new JFileChooser();
                openFile.showOpenDialog(null);
            }
        });

        frame.add(new JLabel("File Chooser"), BorderLayout.NORTH);
        frame.add(saveBtn, BorderLayout.CENTER);
        frame.add(openBtn, BorderLayout.SOUTH);
        frame.setTitle("File Chooser");
        frame.pack();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
}

Setting background colour of Android layout element

4 possible ways, use one you need.

1. Kotlin

val ll = findViewById<LinearLayout>(R.id.your_layout_id)
ll.setBackgroundColor(ContextCompat.getColor(this, R.color.white))

2. Data Binding

<LinearLayout
    android:background="@{@color/white}"

OR more useful statement-

<LinearLayout
    android:background="@{model.colorResId}"

3. XML

<LinearLayout
    android:background="#FFFFFF"

<LinearLayout
    android:background="@color/white"

4. Java

LinearLayout ll = (LinearLayout) findViewById(R.id.your_layout_id);
ll.setBackgroundColor(ContextCompat.getColor(this, R.color.white));

PHP $_FILES['file']['tmp_name']: How to preserve filename and extension?

Like @Gabi Purcaru mentions above, the proper way to rename and move the file is to use move_uploaded_file(). It performs some safety checks to prevent security vulnerabilities and other exploits. You'll need to sanitize the value of $_FILES['file']['name'] if you want to use it or an extension derived from it. Use pathinfo($_FILES['file']['name'], PATHINFO_EXTENSION) to safely get the extension.

How to split one string into multiple variables in bash shell?

Using bash regex capabilities:

re="^([^-]+)-(.*)$"
[[ "ABCDE-123456" =~ $re ]] && var1="${BASH_REMATCH[1]}" && var2="${BASH_REMATCH[2]}"
echo $var1
echo $var2

OUTPUT

ABCDE
123456

Where are static methods and static variables stored in Java?

Prior to Java 8:

The static variables were stored in the permgen space(also called the method area).

PermGen Space is also known as Method Area

PermGen Space used to store 3 things

Class level data (meta-data)
interned strings
static variables

From Java 8 onwards

The static variables are stored in the Heap itself.From Java 8 onwards the PermGen Space have been removed and new space named as MetaSpace is introduced which is not the part of Heap any more unlike the previous Permgen Space. Meta-Space is present on the native memory (memory provided by the OS to a particular Application for its own usage) and it now only stores the class meta-data.

The interned strings and static variables are moved into the heap itself.

For official information refer : JEP 122:Remove the Permanent Gen Space

Postman: sending nested JSON object

Select the body tab and select application/json in the Content-Type drop-down and add a body like this:

{
  "Username":"ABC",
  "Password":"ABC"
}

How do you create a dropdownlist from an enum in ASP.NET MVC?

Well I'm really late to the party, but for what it is worth, I have blogged about this very subject whereby I create a EnumHelper class that enables very easy transformation.

http://jnye.co/Posts/4/creating-a-dropdown-list-from-an-enum-in-mvc-and-c%23

In your controller:

//If you don't have an enum value use the type
ViewBag.DropDownList = EnumHelper.SelectListFor<MyEnum>();

//If you do have an enum value use the value (the value will be marked as selected)    
ViewBag.DropDownList = EnumHelper.SelectListFor(MyEnum.MyEnumValue);

In your View:

@Html.DropDownList("DropDownList")
@* OR *@
@Html.DropDownListFor(m => m.Property, ViewBag.DropDownList as SelectList, null)

The helper class:

public static class EnumHelper
{
    // Get the value of the description attribute if the   
    // enum has one, otherwise use the value.  
    public static string GetDescription<TEnum>(this TEnum value)
    {
        var fi = value.GetType().GetField(value.ToString());

        if (fi != null)
        {
            var attributes = (DescriptionAttribute[])fi.GetCustomAttributes(typeof(DescriptionAttribute), false);

            if (attributes.Length > 0)
            {
                return attributes[0].Description;
            }
        }

        return value.ToString();
    }

    /// <summary>
    /// Build a select list for an enum
    /// </summary>
    public static SelectList SelectListFor<T>() where T : struct
    {
        Type t = typeof(T);
        return !t.IsEnum ? null
                         : new SelectList(BuildSelectListItems(t), "Value", "Text");
    }

    /// <summary>
    /// Build a select list for an enum with a particular value selected 
    /// </summary>
    public static SelectList SelectListFor<T>(T selected) where T : struct
    {
        Type t = typeof(T);
        return !t.IsEnum ? null
                         : new SelectList(BuildSelectListItems(t), "Text", "Value", selected.ToString());
    }

    private static IEnumerable<SelectListItem> BuildSelectListItems(Type t)
    {
        return Enum.GetValues(t)
                   .Cast<Enum>()
                   .Select(e => new SelectListItem { Value = e.ToString(), Text = e.GetDescription() });
    }
}

Watermark / hint text / placeholder TextBox

@Veton - I really like the simplicity of your solution but my reputation isn't high enough to bump you yet.

@Tim Murphy - That "Two-way binding requires Path or XPath" error was an easy fix... updated code including some other little tweaks (only WPF tested):

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Media;

public class TextBoxWatermarked : TextBox
{
  public string Watermark
  {
    get { return (string)GetValue(WaterMarkProperty); }
    set { SetValue(WaterMarkProperty, value); }
  }
  public static readonly DependencyProperty WaterMarkProperty =
      DependencyProperty.Register("Watermark", typeof(string), typeof(TextBoxWatermarked), new PropertyMetadata(new PropertyChangedCallback(OnWatermarkChanged)));

  private bool _isWatermarked = false;
  private Binding _textBinding = null;

  public TextBoxWatermarked()
  {
    Loaded += (s, ea) => ShowWatermark();
  }

  protected override void OnGotFocus(RoutedEventArgs e)
  {
    base.OnGotFocus(e);
    HideWatermark();
  }

  protected override void OnLostFocus(RoutedEventArgs e)
  {
    base.OnLostFocus(e);
    ShowWatermark();
  }

  private static void OnWatermarkChanged(DependencyObject sender, DependencyPropertyChangedEventArgs ea)
  {
    var tbw = sender as TextBoxWatermarked;
    if (tbw == null || !tbw.IsLoaded) return; //needed to check IsLoaded so that we didn't dive into the ShowWatermark() routine before initial Bindings had been made
    tbw.ShowWatermark();
  }

  private void ShowWatermark()
  {
    if (String.IsNullOrEmpty(Text) && !String.IsNullOrEmpty(Watermark))
    {
      _isWatermarked = true;

      //save the existing binding so it can be restored
      _textBinding = BindingOperations.GetBinding(this, TextProperty);

      //blank out the existing binding so we can throw in our Watermark
      BindingOperations.ClearBinding(this, TextProperty);

      //set the signature watermark gray
      Foreground = new SolidColorBrush(Colors.Gray);

      //display our watermark text
      Text = Watermark;
    }
  }

  private void HideWatermark()
  {
    if (_isWatermarked)
    {
      _isWatermarked = false;
      ClearValue(ForegroundProperty);
      Text = "";
      if (_textBinding != null) SetBinding(TextProperty, _textBinding);
    }
  }

}

Need a good hex editor for Linux

Personally, I use Emacs with hexl-mod.

Emacs is able to work with really huge files. You can use search/replace value easily. Finally, you can use 'ediff' to do some diffs.

How do I remove an array item in TypeScript?

Just wanted to add extension method for an array.

interface Array<T> {
      remove(element: T): Array<T>;
    }

    Array.prototype.remove = function (element) {
      const index = this.indexOf(element, 0);
      if (index > -1) {
        return this.splice(index, 1);
      }
      return this;
    };

Python: finding an element in a list

assuming you want to find a value in a numpy array, I guess something like this might work:

Numpy.where(arr=="value")[0]

Take n rows from a spark dataframe and pass to toPandas()

You could get first rows of Spark DataFrame with head and then create Pandas DataFrame:

l = [('Alice', 1),('Jim',2),('Sandra',3)]
df = sqlContext.createDataFrame(l, ['name', 'age'])

df_pandas = pd.DataFrame(df.head(3), columns=df.columns)

In [4]: df_pandas
Out[4]: 
     name  age
0   Alice    1
1     Jim    2
2  Sandra    3

Difference between IISRESET and IIS Stop-Start command

Take IISReset as a suite of commands that helps you manage IIS start / stop etc.

Which means you need to specify option (/switch) what you want to do to carry any operation.

Default behavior OR default switch is /restart with iisreset so you do not need to run command twice with /start and /stop.

Hope this clarifies your question. For reference the output of iisreset /? is:

IISRESET.EXE (c) Microsoft Corp. 1998-2005

Usage:
iisreset [computername]

    /RESTART            Stop and then restart all Internet services.
    /START              Start all Internet services.
    /STOP               Stop all Internet services.
    /REBOOT             Reboot the computer.
    /REBOOTONERROR      Reboot the computer if an error occurs when starting,
                        stopping, or restarting Internet services.
    /NOFORCE            Do not forcefully terminate Internet services if
                        attempting to stop them gracefully fails.
    /TIMEOUT:val        Specify the timeout value ( in seconds ) to wait for
                        a successful stop of Internet services. On expiration
                        of this timeout the computer can be rebooted if
                        the /REBOOTONERROR parameter is specified.
                        The default value is 20s for restart, 60s for stop,
                        and 0s for reboot.
    /STATUS             Display the status of all Internet services.
    /ENABLE             Enable restarting of Internet Services
                        on the local system.
    /DISABLE            Disable restarting of Internet Services
                        on the local system.

Check if a variable is of function type

you should use typeOf operator in js.

var a=function(){
    alert("fun a");
}
alert(typeof a);// alerts "function"

Apache 2.4 - Request exceeded the limit of 10 internal redirects due to probable configuration error

Solved this by adding following

RewriteCond %{ENV:REDIRECT_STATUS} 200 [OR]
 RewriteCond %{REQUEST_FILENAME} -f [OR]
 RewriteCond %{REQUEST_FILENAME} -d
 RewriteRule ^ - [L]

RecyclerView expand/collapse items

I know it has been a long time since the original question was posted. But i think for slow ones like me a bit of explanation of @Heisenberg's answer would help.

Declare two variable in the adapter class as

private int mExpandedPosition= -1;
private RecyclerView recyclerView = null;

Then in onBindViewHolder following as given in the original answer.

      // This line checks if the item displayed on screen 
      // was expanded or not (Remembering the fact that Recycler View )
      // reuses views so onBindViewHolder will be called for all
      // items visible on screen.
    final boolean isExpanded = position==mExpandedPosition;

        //This line hides or shows the layout in question
        holder.details.setVisibility(isExpanded?View.VISIBLE:View.GONE);

        // I do not know what the heck this is :)
        holder.itemView.setActivated(isExpanded);

        // Click event for each item (itemView is an in-built variable of holder class)
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

 // if the clicked item is already expaned then return -1 
//else return the position (this works with notifyDatasetchanged )
                mExpandedPosition = isExpanded ? -1:position;
    // fancy animations can skip if like
                TransitionManager.beginDelayedTransition(recyclerView);
    //This will call the onBindViewHolder for all the itemViews on Screen
                notifyDataSetChanged();
            }
        });

And lastly to get the recyclerView object in the adapter override

@Override
public void onAttachedToRecyclerView(@NonNull RecyclerView recyclerView) {
    super.onAttachedToRecyclerView(recyclerView);

    this.recyclerView = recyclerView;
}

Hope this Helps.

How to redirect to previous page in Ruby On Rails?

In rails 5, as per the instructions in Rails Guides, you can use:

redirect_back(fallback_location: root_path)

The 'back' location is pulled from the HTTP_REFERER header which is not guaranteed to be set by the browser. Thats why you should provide a 'fallback_location'.

Share data between html pages

why don't you store your values in HTML5 storage objects such as sessionStorage or localStorage, visit HTML5 Storage Doc to get more details. Using this you can store intermediate values temporarily/permanently locally and then access your values later.

To store values for a session:

sessionStorage.getItem('label')
sessionStorage.setItem('label', 'value')

or more permanently:

localStorage.getItem('label')
localStorage.setItem('label', 'value')

So you can store (temporarily) form data between multiple pages using HTML5 storage objects which you can even retain after reload..

The ternary (conditional) operator in C

like dwn said, Performance was one of its benefits during the rise of complex processors, MSDN blog Non-classical processor behavior: How doing something can be faster than not doing it gives an example which clearly says the difference between ternary (conditional) operator and if/else statement.

give the following code:

#include <windows.h>
#include <stdlib.h>
#include <stdlib.h>
#include <stdio.h>

int array[10000];

int countthem(int boundary)
{
 int count = 0;
 for (int i = 0; i < 10000; i++) {
  if (array[i] < boundary) count++;
 }
 return count;
}

int __cdecl wmain(int, wchar_t **)
{
 for (int i = 0; i < 10000; i++) array[i] = rand() % 10;

 for (int boundary = 0; boundary <= 10; boundary++) {
  LARGE_INTEGER liStart, liEnd;
  QueryPerformanceCounter(&liStart);

  int count = 0;
  for (int iterations = 0; iterations < 100; iterations++) {
   count += countthem(boundary);
  }

  QueryPerformanceCounter(&liEnd);
  printf("count=%7d, time = %I64d\n",
         count, liEnd.QuadPart - liStart.QuadPart);
 }
 return 0;
}

the cost for different boundary are much different and wierd (see the original material). while if change:

 if (array[i] < boundary) count++;

 count += (array[i] < boundary) ? 1 : 0;

The execution time is now independent of the boundary value, since:

the optimizer was able to remove the branch from the ternary expression.

but on my desktop intel i5 cpu/windows 10/vs2015, my test result is quite different with msdn blog.

when using debug mode, if/else cost:

count=      0, time = 6434
count= 100000, time = 7652
count= 200800, time = 10124
count= 300200, time = 12820
count= 403100, time = 15566
count= 497400, time = 16911
count= 602900, time = 15999
count= 700700, time = 12997
count= 797500, time = 11465
count= 902500, time = 7619
count=1000000, time = 6429

and ternary operator cost:

count=      0, time = 7045
count= 100000, time = 10194
count= 200800, time = 12080
count= 300200, time = 15007
count= 403100, time = 18519
count= 497400, time = 20957
count= 602900, time = 17851
count= 700700, time = 14593
count= 797500, time = 12390
count= 902500, time = 9283
count=1000000, time = 7020

when using release mode, if/else cost:

count=      0, time = 7
count= 100000, time = 9
count= 200800, time = 9
count= 300200, time = 9
count= 403100, time = 9
count= 497400, time = 8
count= 602900, time = 7
count= 700700, time = 7
count= 797500, time = 10
count= 902500, time = 7
count=1000000, time = 7

and ternary operator cost:

count=      0, time = 16
count= 100000, time = 17
count= 200800, time = 18
count= 300200, time = 16
count= 403100, time = 22
count= 497400, time = 16
count= 602900, time = 16
count= 700700, time = 15
count= 797500, time = 15
count= 902500, time = 16
count=1000000, time = 16

the ternary operator is slower than if/else statement on my machine!

so according to different compiler optimization techniques, ternal operator and if/else may behaves much different.

What does <> mean?

Yes in SQl <> is the same as != which is not equal.....excepts for NULLS of course, in that case you need to use IS NULL or IS NOT NULL

In c# what does 'where T : class' mean?

T represents an object type of, it implies that you can give any type of. IList : if IList s=new IList; Now s.add("Always accept string.").

Getting value from table cell in JavaScript...not jQuery

If you are looking for the contents of the TD (cell), then it would simply be: col.innerHTML

I.e: alert(col.innerHTML);

You'll then need to parse that for any values you're looking for.

Powershell: A positional parameter cannot be found that accepts argument "xxx"

In my case I had tried to make code more readable by putting:

"LONGTEXTSTRING " +
"LONGTEXTSTRING" +
"LONGTEXTSTRING"

Once I changed it to

LONGTEXTSTRING LONGTEXTSTRING LONGTEXTSTRING

Then it worked

Build project into a JAR automatically in Eclipse

Using Thomas Bratt's answer above, just make sure your build.xml is configured properly :

<?xml version="1.0" ?>
<!-- Configuration of the Ant build system to generate a Jar file --> 
<project name="TestMain" default="CreateJar">
  <target name="CreateJar" description="Create Jar file">
        <jar jarfile="Test.jar" basedir="bin/" includes="**/*.class" />
  </target>
</project>

(Notice the double asterisk - it will tell build to look for .class files in all sub-directories.)

How do I use MySQL through XAMPP?

Changing XAMPP Default Port: If you want to get XAMPP up and running, you should consider changing the port from the default 80 to say 7777.

In the XAMPP Control Panel, click on the Apache – Config button which is located next to the ‘Logs’ button.
Select ‘Apache (httpd.conf)’ from the drop down. (Notepad should open)
Do Ctrl+F to find ’80’ and change line Listen 80 to Listen 7777
Find again and change line ServerName localhost:80 to ServerName localhost:7777
Save and re-start Apache. It should be running by now.

The only demerit to this technique is, you have to explicitly include the port number in the localhost url. Rather than http://localhost it becomes http://localhost:7777.

Counting repeated elements in an integer array

public class ArrayDuplicate {
private static Scanner sc;
static int totalCount = 0;

    public static void main(String[] args) {
        int n, num;
        sc = new Scanner(System.in);
        System.out.print("Enter the size of array: ");
        n =sc.nextInt();
        int[] a = new int[n];
        for(int i=0;i<n;i++){
            System.out.print("Enter the element at position "+i+": ");
            num = sc.nextInt();
            a[enter image description here][1][i]=num;
        }
        System.out.print("Elements in array are: ");
        for(int i=0;i<a.length;i++)
            System.out.print(a[i]+" ");
        System.out.println();
        duplicate(a);
        System.out.println("There are "+totalCount+" repeated numbers:");
    }

    public static void duplicate(int[] a){
        int j = 0,count, recount, temp;
        for(int i=0; i<a.length;i++){
            count = 0;
            recount = 0;
            j=i+1;
            while(j<a.length){
                if(a[i]==a[j])
                    count++;
                j++;
            }
            if(count>0){
                temp = a[i];
                for(int x=0;x<i;x++){
                    if(a[x]==temp)
                        recount++;
                }
                if(recount==0){                 
                    totalCount++;
                    System.out.println(+a[i]+" : "+count+" times");
                }   
            }

        }
    }

}

PHP AES encrypt / decrypt

This is a working solution of AES encryption - implemented using openssl. It uses the Cipher Block Chaining Mode (CBC-Mode). Thus, alongside data and key, you can specify iv and block size

 <?php
      class AESEncryption {

            protected $key;
            protected $data;
            protected $method;
            protected $iv;

            /**
             * Available OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING
             *
             * @var type $options
             */
            protected $options = 0;

            /**
             * 
             * @param type $data
             * @param type $key
             * @param type $iv
             * @param type $blockSize
             * @param type $mode
             */
            public function __construct($data = null, $key = null, $iv = null, $blockSize = null, $mode = 'CBC') {
                $this->setData($data);
                $this->setKey($key);
                $this->setInitializationVector($iv);
                $this->setMethod($blockSize, $mode);
            }

            /**
             * 
             * @param type $data
             */
            public function setData($data) {
                $this->data = $data;
            }

            /**
             * 
             * @param type $key
             */
            public function setKey($key) {
                $this->key = $key;
            }

            /**
             * CBC 128 192 256 
              CBC-HMAC-SHA1 128 256
              CBC-HMAC-SHA256 128 256
              CFB 128 192 256
              CFB1 128 192 256
              CFB8 128 192 256
              CTR 128 192 256
              ECB 128 192 256
              OFB 128 192 256
              XTS 128 256
             * @param type $blockSize
             * @param type $mode
             */
            public function setMethod($blockSize, $mode = 'CBC') {
                if($blockSize==192 && in_array('', array('CBC-HMAC-SHA1','CBC-HMAC-SHA256','XTS'))){
                    $this->method=null;
                    throw new Exception('Invalid block size and mode combination!');
                }
                $this->method = 'AES-' . $blockSize . '-' . $mode;
            }

            /**
             * 
             * @param type $data
             */
            public function setInitializationVector($iv) {
                $this->iv = $iv;
            }

            /**
             * 
             * @return boolean
             */
            public function validateParams() {
                if ($this->data != null &&
                        $this->method != null ) {
                    return true;
                } else {
                    return FALSE;
                }
            }

            //it must be the same when you encrypt and decrypt
            protected function getIV() { 
                return $this->iv;
            }

             /**
             * @return type
             * @throws Exception
             */
            public function encrypt() {
                if ($this->validateParams()) { 
                    return trim(openssl_encrypt($this->data, $this->method, $this->key, $this->options,$this->getIV()));
                } else {
                    throw new Exception('Invalid params!');
                }
            }

            /**
             * 
             * @return type
             * @throws Exception
             */
            public function decrypt() {
                if ($this->validateParams()) {
                   $ret=openssl_decrypt($this->data, $this->method, $this->key, $this->options,$this->getIV());

                   return   trim($ret); 
                } else {
                    throw new Exception('Invalid params!');
                }
            }

        }

Sample usage:

<?php
        $data = json_encode(['first_name'=>'Dunsin','last_name'=>'Olubobokun','country'=>'Nigeria']);
        $inputKey = "W92ZB837943A711B98D35E799DFE3Z18";
        $iv = "tuqZQhKP48e8Piuc";
        $blockSize = 256;
        $aes = new AESEncryption($data, $inputKey, $iv, $blockSize);
        $enc = $aes->encrypt();
        $aes->setData($enc);
        $dec=$aes->decrypt();
        echo "After encryption: ".$enc."<br/>";
        echo "After decryption: ".$dec."<br/>";

Python: Remove division decimal

>>> int(2.0)

You will get the answer as 2

Best font for coding

Funny, I was just researching this yesterday!

I personally use Monaco 10 or 11 for the Mac, but a good cross platform font would have to be Droid Sans Mono: http://damieng.com/blog/2007/11/14/droid-sans-mono-great-coding-font Or DejaVu sans mono is another great one (goes under a lot of different names, will be Menlo on SNow leopard and is really just a repackaged Prima/Vera) check it out here: Prima/Vera... Check it out here: http://dejavu-fonts.org/wiki/index.php?title=Download

How to access my localhost from another PC in LAN?

Actualy you don't need an internet connection to use ip address. Each computer in LAN has an internal IP address you can discover by runing

ipconfig /all

in cmd.

You can use the ip address of the server (probabily something like 192.168.0.x or 10.0.0.x) to access the website remotely.

If you found the ip and still cannot access the website, it means WAMP is not configured to respond to that name ( what did you call me? 192.168.0.3? That's not my name. I'm Localhost ) and you have to modify ....../apache/config/httpd.conf

Listen *:80

How to create a stacked bar chart for my DataFrame using seaborn?

You could use pandas plot as @Bharath suggest:

import seaborn as sns
sns.set()
df.set_index('App').T.plot(kind='bar', stacked=True)

Output:

Updated:

from matplotlib.colors import ListedColormap df.set_index('App')\ .reindex_axis(df.set_index('App').sum().sort_values().index, axis=1)\ .T.plot(kind='bar', stacked=True, colormap=ListedColormap(sns.color_palette("GnBu", 10)), figsize=(12,6))

Updated Pandas 0.21.0+ reindex_axis is deprecated, use reindex

from matplotlib.colors import ListedColormap

df.set_index('App')\
  .reindex(df.set_index('App').sum().sort_values().index, axis=1)\
  .T.plot(kind='bar', stacked=True,
          colormap=ListedColormap(sns.color_palette("GnBu", 10)), 
          figsize=(12,6))

Output:

Example use of "continue" statement in Python?

Usually the situation where continue is necessary/useful, is when you want to skip the remaining code in the loop and continue iteration.

I don't really believe it's necessary, since you can always use if statements to provide the same logic, but it might be useful to increase readability of code.

Opening A Specific File With A Batch File?

If you are trying to open a file in the same directory it would be:

./PROGRAM TRYING TO OPEN
./FILE NAME/PROGRAM TRYING TO OPEN (or this)

Or, if trying to backtrack from the same directory it would be:

../PROGRAM TRYING TO OPEN
../FILE NAME/PROGRAM TRYING TO OPEN (or this)

Else, if you need a straight one from start, it would be:

(DIRECTORY TYPE)\Users\%username%\(FILE DIRECTORY)
(ex) C:\Users\ajste\Desktop\Henlo.cmd

Disable button after click in JQuery

You can do this in jquery by setting the attribute disabled to 'disabled'.

$(this).prop('disabled', true);

I have made a simple example http://jsfiddle.net/4gnXL/2/

Select box arrow style

Browsers and OS's determine the style of the select boxes in most cases, and it's next to impossible to alter them with CSS alone. You'll have to look into replacement methods. The main trick is to apply appearance: none which lets you override some of the styling.

My favourite method is this one:

http://cssdeck.com/item/265/styling-select-box-with-css3

It doesn't replace the OS select menu UI element so all the problems related to doing that are non-existant (not being able to break out of the browser window with a long list being the main one).

Good luck :)

How to accept Date params in a GET request to Spring MVC Controller?

This is what I did to get formatted date from front end

  @RequestMapping(value = "/{dateString}", method = RequestMethod.GET)
  @ResponseBody
  public HttpStatus getSomething(@PathVariable @DateTimeFormat(iso = DateTimeFormat.ISO.DATE) String dateString) {
   return OK;
  }

You can use it to get what you want.

How can one develop iPhone apps in Java?

Perhaps you should consider Android applications instead of iPhone applications if you really want to develop in Java for smartphones. Android natively uses Java for it's applications; so perhaps this might be a better option?

As for iPhone, I would recommend you to look into Obj-C or C/C++ depending on the type of applications you want to make. Should be fun to dabble into a new language! :)

How to simulate key presses or a click with JavaScript?

Simulating a mouse click

My guess is that the webpage is listening to mousedown rather than click (which is bad for accessibility because when a user uses the keyboard, only focus and click are fired, not mousedown). So you should simulate mousedown, click, and mouseup (which, by the way, is what the iPhone, iPod Touch, and iPad do on tap events).

To simulate the mouse events, you can use this snippet for browsers that support DOM 2 Events. For a more foolproof simulation, fill in the mouse position using initMouseEvent instead.

// DOM 2 Events
var dispatchMouseEvent = function(target, var_args) {
  var e = document.createEvent("MouseEvents");
  // If you need clientX, clientY, etc., you can call
  // initMouseEvent instead of initEvent
  e.initEvent.apply(e, Array.prototype.slice.call(arguments, 1));
  target.dispatchEvent(e);
};
dispatchMouseEvent(element, 'mouseover', true, true);
dispatchMouseEvent(element, 'mousedown', true, true);
dispatchMouseEvent(element, 'click', true, true);
dispatchMouseEvent(element, 'mouseup', true, true);

When you fire a simulated click event, the browser will actually fire the default action (e.g. navigate to the link's href, or submit a form).

In IE, the equivalent snippet is this (unverified since I don't have IE). I don't think you can give the event handler mouse positions.

// IE 5.5+
element.fireEvent("onmouseover");
element.fireEvent("onmousedown");
element.fireEvent("onclick");  // or element.click()
element.fireEvent("onmouseup");

Simulating keydown and keypress

You can simulate keydown and keypress events, but unfortunately in Chrome they only fire the event handlers and don't perform any of the default actions. I think this is because the DOM 3 Events working draft describes this funky order of key events:

keydown (often has default action such as fire click, submit, or textInput events)
keypress (if the key isn't just a modifier key like Shift or Ctrl)
(keydown, keypress) with repeat=true if the user holds down the button
default actions of keydown!!
keyup

This means that you have to (while combing the HTML5 and DOM 3 Events drafts) simulate a large amount of what the browser would otherwise do. I hate it when I have to do that. For example, this is roughly how to simulate a key press on an input or textarea.

// DOM 3 Events
var dispatchKeyboardEvent = function(target, initKeyboradEvent_args) {
  var e = document.createEvent("KeyboardEvents");
  e.initKeyboardEvent.apply(e, Array.prototype.slice.call(arguments, 1));
  target.dispatchEvent(e);
};
var dispatchTextEvent = function(target, initTextEvent_args) {
  var e = document.createEvent("TextEvent");
  e.initTextEvent.apply(e, Array.prototype.slice.call(arguments, 1));
  target.dispatchEvent(e);
};
var dispatchSimpleEvent = function(target, type, canBubble, cancelable) {
  var e = document.createEvent("Event");
  e.initEvent.apply(e, Array.prototype.slice.call(arguments, 1));
  target.dispatchEvent(e);
};

var canceled = !dispatchKeyboardEvent(element,
    'keydown', true, true,  // type, bubbles, cancelable
    null,  // window
    'h',  // key
    0, // location: 0=standard, 1=left, 2=right, 3=numpad, 4=mobile, 5=joystick
    '');  // space-sparated Shift, Control, Alt, etc.
dispatchKeyboardEvent(
    element, 'keypress', true, true, null, 'h', 0, '');
if (!canceled) {
  if (dispatchTextEvent(element, 'textInput', true, true, null, 'h', 0)) {
    element.value += 'h';
    dispatchSimpleEvent(element, 'input', false, false);
    // not supported in Chrome yet
    // if (element.form) element.form.dispatchFormInput();
    dispatchSimpleEvent(element, 'change', false, false);
    // not supported in Chrome yet
    // if (element.form) element.form.dispatchFormChange();
  }
}
dispatchKeyboardEvent(
    element, 'keyup', true, true, null, 'h', 0, '');

I don't think it is possible to simulate key events in IE.

HTML 5 video recording and storing a stream

RecordRTC: WebRTC audio/video recording

https://github.com/muaz-khan/WebRTC-Experiment/tree/master/RecordRTC

Audio recording both for Chrome and Firefox
Video/Gif recording for Chrome; (Firefox has a little bit issues, will be recovered soon)

Demo : https://www.webrtc-experiment.com/RecordRTC/

Creating .webm video from getUserMedia()

http://ericbidelman.tumblr.com/post/31486670538/creating-webm-video-from-getusermedia

Demo : http://html5-demos.appspot.com/static/getusermedia/record-user-webm.html

Capturing Audio & Video in HTML5

http://www.html5rocks.com/en/tutorials/getusermedia/intro/

How do I execute cmd commands through a batch file?

@echo off
title Command Executer
color 1b

echo Command Executer by: YourNameHere
echo #################################
: execute
echo Please Type A Command Here:
set /p cmd=Command:
%cmd%
goto execute

How to access to the parent object in c#

Why not change the constructor on Production to let you pass in a reference at construction time:

public class Meter
{
   private int _powerRating = 0; 
   private Production _production;

   public Meter()
   {
      _production = new Production(this);
   }
}

In the Production constructor you can assign this to a private field or a property. Then Production will always have access to is parent.

ASP.NET Web API session or something?

Well, REST by design is stateless. By adding session (or anything else of that kind) you are making it stateful and defeating any purpose of having a RESTful API.

The whole idea of RESTful service is that every resource is uniquely addressable using a universal syntax for use in hypermedia links and each HTTP request should carry enough information by itself for its recipient to process it to be in complete harmony with the stateless nature of HTTP".

So whatever you are trying to do with Web API here, should most likely be re-architectured if you wish to have a RESTful API.

With that said, if you are still willing to go down that route, there is a hacky way of adding session to Web API, and it's been posted by Imran here http://forums.asp.net/t/1780385.aspx/1

Code (though I wouldn't really recommend that):

public class MyHttpControllerHandler
  : HttpControllerHandler, IRequiresSessionState
{
    public MyHttpControllerHandler(RouteData routeData): base(routeData)
    { }
}

public class MyHttpControllerRouteHandler : HttpControllerRouteHandler
{
    protected override IHttpHandler GetHttpHandler(RequestContext requestContext)
    {
        return new MyHttpControllerHandler(requestContext.RouteData);
    }
}

public class ValuesController : ApiController
{
   public string GET(string input)
   {
       var session = HttpContext.Current.Session;
       if (session != null)
       {
           if (session["Time"] == null)
           {
               session["Time"] = DateTime.Now;
           }
           return "Session Time: " + session["Time"] + input;
       }
       return "Session is not availabe" + input;
    }
}

and then add the HttpControllerHandler to your API route:

route.RouteHandler = new MyHttpControllerRouteHandler();

For files in directory, only echo filename (no path)

You can either use what SiegeX said above or if you aren't interested in learning/using parameter expansion, you can use:

for filename in $(ls /home/user/);
do
    echo $filename
done;

Environment variable to control java.io.tmpdir?

we can change the default tomcat file upload location, as

we have to set the environment variable like : CATALINA_TEMPDIR = YOUR FILE UPLOAD LOCATION. this location will change the path here: java -Djava.io.tmpdir=/path/to/tmpdir

Send string to stdin

aliases can and can't process piped stdin...

Here we create 3 lines of output

$ echo -e "line 1\nline 2\nline 3"
line 1
line 2
line 3

We then pipe the output to stdin of the sed command to put them all on one line

$ echo -e "line 1\nline 2\nline 3" |  sed -e ":a;N;\$!ba ;s?\n? ?g"
line 1 line 2 line 3

If we define an alias of the same sed command

$ alias oline='sed -e ":a;N;\$!ba ;s?\n? ?g"'

We can pipe the output to the stdin of the alias and it behaves exactly the same

$ echo -e "line 1\nline 2\nline 3" |  oline
line 1 line 2 line 3

The problem arises when we try to define the alias as a function

$ alias oline='function _oline(){ sed -e ":a;N;\$!ba ;s?\n? ?g";}_oline'

Defining the alias as a funstion breaks the pipe

$ echo -e "line 1\nline 2\nline 3" |  oline
>

Disable form auto submit on button click

Buttons like <button>Click to do something</button> are submit buttons.

Set type="button" to change that. type="submit" is the default (as specified by the HTML recommendation).

Assigning strings to arrays of characters

There is no such thing as a "string" in C. In C, strings are one-dimensional array of char, terminated by a null character \0. Since you can't assign arrays in C, you can't assign strings either. The literal "hello" is syntactic sugar for const char x[] = {'h','e','l','l','o','\0'};

The correct way would be:

char s[100];
strncpy(s, "hello", 100);

or better yet:

#define STRMAX 100
char    s[STRMAX];
size_t  len;
len = strncpy(s, "hello", STRMAX);

How to provide a file download from a JSF backing bean?

Introduction

You can get everything through ExternalContext. In JSF 1.x, you can get the raw HttpServletResponse object by ExternalContext#getResponse(). In JSF 2.x, you can use the bunch of new delegate methods like ExternalContext#getResponseOutputStream() without the need to grab the HttpServletResponse from under the JSF hoods.

On the response, you should set the Content-Type header so that the client knows which application to associate with the provided file. And, you should set the Content-Length header so that the client can calculate the download progress, otherwise it will be unknown. And, you should set the Content-Disposition header to attachment if you want a Save As dialog, otherwise the client will attempt to display it inline. Finally just write the file content to the response output stream.

Most important part is to call FacesContext#responseComplete() to inform JSF that it should not perform navigation and rendering after you've written the file to the response, otherwise the end of the response will be polluted with the HTML content of the page, or in older JSF versions, you will get an IllegalStateException with a message like getoutputstream() has already been called for this response when the JSF implementation calls getWriter() to render HTML.

Turn off ajax / don't use remote command!

You only need to make sure that the action method is not called by an ajax request, but that it is called by a normal request as you fire with <h:commandLink> and <h:commandButton>. Ajax requests and remote commands are handled by JavaScript which in turn has, due to security reasons, no facilities to force a Save As dialogue with the content of the ajax response.

In case you're using e.g. PrimeFaces <p:commandXxx>, then you need to make sure that you explicitly turn off ajax via ajax="false" attribute. In case you're using ICEfaces, then you need to nest a <f:ajax disabled="true" /> in the command component.

Generic JSF 2.x example

public void download() throws IOException {
    FacesContext fc = FacesContext.getCurrentInstance();
    ExternalContext ec = fc.getExternalContext();

    ec.responseReset(); // Some JSF component library or some Filter might have set some headers in the buffer beforehand. We want to get rid of them, else it may collide.
    ec.setResponseContentType(contentType); // Check http://www.iana.org/assignments/media-types for all types. Use if necessary ExternalContext#getMimeType() for auto-detection based on filename.
    ec.setResponseContentLength(contentLength); // Set it with the file size. This header is optional. It will work if it's omitted, but the download progress will be unknown.
    ec.setResponseHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\""); // The Save As popup magic is done here. You can give it any file name you want, this only won't work in MSIE, it will use current request URL as file name instead.

    OutputStream output = ec.getResponseOutputStream();
    // Now you can write the InputStream of the file to the above OutputStream the usual way.
    // ...

    fc.responseComplete(); // Important! Otherwise JSF will attempt to render the response which obviously will fail since it's already written with a file and closed.
}

Generic JSF 1.x example

public void download() throws IOException {
    FacesContext fc = FacesContext.getCurrentInstance();
    HttpServletResponse response = (HttpServletResponse) fc.getExternalContext().getResponse();

    response.reset(); // Some JSF component library or some Filter might have set some headers in the buffer beforehand. We want to get rid of them, else it may collide.
    response.setContentType(contentType); // Check http://www.iana.org/assignments/media-types for all types. Use if necessary ServletContext#getMimeType() for auto-detection based on filename.
    response.setContentLength(contentLength); // Set it with the file size. This header is optional. It will work if it's omitted, but the download progress will be unknown.
    response.setHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\""); // The Save As popup magic is done here. You can give it any file name you want, this only won't work in MSIE, it will use current request URL as file name instead.

    OutputStream output = response.getOutputStream();
    // Now you can write the InputStream of the file to the above OutputStream the usual way.
    // ...

    fc.responseComplete(); // Important! Otherwise JSF will attempt to render the response which obviously will fail since it's already written with a file and closed.
}

Common static file example

In case you need to stream a static file from the local disk file system, substitute the code as below:

File file = new File("/path/to/file.ext");
String fileName = file.getName();
String contentType = ec.getMimeType(fileName); // JSF 1.x: ((ServletContext) ec.getContext()).getMimeType(fileName);
int contentLength = (int) file.length();

// ...

Files.copy(file.toPath(), output);

Common dynamic file example

In case you need to stream a dynamically generated file, such as PDF or XLS, then simply provide output there where the API being used expects an OutputStream.

E.g. iText PDF:

String fileName = "dynamic.pdf";
String contentType = "application/pdf";

// ...

Document document = new Document();
PdfWriter writer = PdfWriter.getInstance(document, output);
document.open();
// Build PDF content here.
document.close();

E.g. Apache POI HSSF:

String fileName = "dynamic.xls";
String contentType = "application/vnd.ms-excel";

// ...

HSSFWorkbook workbook = new HSSFWorkbook();
// Build XLS content here.
workbook.write(output);
workbook.close();

Note that you cannot set the content length here. So you need to remove the line to set response content length. This is technically no problem, the only disadvantage is that the enduser will be presented an unknown download progress. In case this is important, then you really need to write to a local (temporary) file first and then provide it as shown in previous chapter.

Utility method

If you're using JSF utility library OmniFaces, then you can use one of the three convenient Faces#sendFile() methods taking either a File, or an InputStream, or a byte[], and specifying whether the file should be downloaded as an attachment (true) or inline (false).

public void download() throws IOException {
    Faces.sendFile(file, true);
}

Yes, this code is complete as-is. You don't need to invoke responseComplete() and so on yourself. This method also properly deals with IE-specific headers and UTF-8 filenames. You can find source code here.

'git status' shows changed files, but 'git diff' doesn't

I used git svn, and had this problem for one file. Using ls-tree for each ancestor of the file, I noticed that one had 2 subfolders - Submit and submit. Since I was on Windows, they couldn't both be checked out, causing this issue.

The solution was to delete one of them directly from TortoiseSVN Repo-browser, then to run git svn fetch followed by git reset --hard origin/trunk.

How to find substring from string?

If you are utilizing arrays too much then you should include cstring.h because it has too many functions including finding substrings.

Regex any ASCII character

Depending on what you mean with "ASCII character" you could simply try:

xxx.+xxx

How to create a DateTime equal to 15 minutes ago?

This is simply what to do:

datetime.datetime.now() - datetime.timedelta(minutes = 15)

timedeltas are specifically designed to allow you to subtract or add deltas (differences) to datetimes.

System not declared in scope?

You need to add:

 #include <cstdlib>

in order for the compiler to see the prototype for system().

Determine if Android app is being used for the first time

I suggest to not only store a boolean flag, but the complete version code. This way you can also query at the beginning if it is the first start in a new version. You can use this information to display a "Whats new" dialog, for example.

The following code should work from any android class that "is a context" (activities, services, ...). If you prefer to have it in a separate (POJO) class, you could consider using a "static context", as described here for example.

/**
 * Distinguishes different kinds of app starts: <li>
 * <ul>
 * First start ever ({@link #FIRST_TIME})
 * </ul>
 * <ul>
 * First start in this version ({@link #FIRST_TIME_VERSION})
 * </ul>
 * <ul>
 * Normal app start ({@link #NORMAL})
 * </ul>
 * 
 * @author schnatterer
 * 
 */
public enum AppStart {
    FIRST_TIME, FIRST_TIME_VERSION, NORMAL;
}

/**
 * The app version code (not the version name!) that was used on the last
 * start of the app.
 */
private static final String LAST_APP_VERSION = "last_app_version";

/**
 * Finds out started for the first time (ever or in the current version).<br/>
 * <br/>
 * Note: This method is <b>not idempotent</b> only the first call will
 * determine the proper result. Any subsequent calls will only return
 * {@link AppStart#NORMAL} until the app is started again. So you might want
 * to consider caching the result!
 * 
 * @return the type of app start
 */
public AppStart checkAppStart() {
    PackageInfo pInfo;
    SharedPreferences sharedPreferences = PreferenceManager
            .getDefaultSharedPreferences(this);
    AppStart appStart = AppStart.NORMAL;
    try {
        pInfo = getPackageManager().getPackageInfo(getPackageName(), 0);
        int lastVersionCode = sharedPreferences
                .getInt(LAST_APP_VERSION, -1);
        int currentVersionCode = pInfo.versionCode;
        appStart = checkAppStart(currentVersionCode, lastVersionCode);
        // Update version in preferences
        sharedPreferences.edit()
                .putInt(LAST_APP_VERSION, currentVersionCode).commit();
    } catch (NameNotFoundException e) {
        Log.w(Constants.LOG,
                "Unable to determine current app version from pacakge manager. Defenisvely assuming normal app start.");
    }
    return appStart;
}

public AppStart checkAppStart(int currentVersionCode, int lastVersionCode) {
    if (lastVersionCode == -1) {
        return AppStart.FIRST_TIME;
    } else if (lastVersionCode < currentVersionCode) {
        return AppStart.FIRST_TIME_VERSION;
    } else if (lastVersionCode > currentVersionCode) {
        Log.w(Constants.LOG, "Current version code (" + currentVersionCode
                + ") is less then the one recognized on last startup ("
                + lastVersionCode
                + "). Defenisvely assuming normal app start.");
        return AppStart.NORMAL;
    } else {
        return AppStart.NORMAL;
    }
}

It could be used from an activity like this:

public class MainActivity extends Activity {        
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        switch (checkAppStart()) {
        case NORMAL:
            // We don't want to get on the user's nerves
            break;
        case FIRST_TIME_VERSION:
            // TODO show what's new
            break;
        case FIRST_TIME:
            // TODO show a tutorial
            break;
        default:
            break;
        }

        // ...
    }
    // ...
}

The basic logic can be verified using this JUnit test:

public void testCheckAppStart() {
    // First start
    int oldVersion = -1;
    int newVersion = 1;
    assertEquals("Unexpected result", AppStart.FIRST_TIME,
            service.checkAppStart(newVersion, oldVersion));

    // First start this version
    oldVersion = 1;
    newVersion = 2;
    assertEquals("Unexpected result", AppStart.FIRST_TIME_VERSION,
            service.checkAppStart(newVersion, oldVersion));

    // Normal start
    oldVersion = 2;
    newVersion = 2;
    assertEquals("Unexpected result", AppStart.NORMAL,
            service.checkAppStart(newVersion, oldVersion));
}

With a bit more effort you could probably test the android related stuff (PackageManager and SharedPreferences) as well. Anyone interested in writing the test? :)

Note that the above code will only work properly if you don't mess around with your android:versionCode in AndroidManifest.xml!

Using NotNull Annotation in method argument

@Nullable and @NotNull do nothing on their own. They are supposed to act as Documentation tools.

The @Nullable Annotation reminds you about the necessity to introduce an NPE check when:

Calling methods that can return null.
Dereferencing variables (fields, local variables, parameters) that can be null.

The @NotNull Annotation is, actually, an explicit contract declaring the following:

A method should not return null.
A variable (like fields, local variables, and parameters) ~~cannot~~ should not hold null value.

For example, instead of writing:

/**
 * @param aX should not be null
 */
public void setX(final Object aX ) {
    // some code
}

You can use:

public void setX(@NotNull final Object aX ) {
    // some code
}

Additionally, @NotNull is often checked by ConstraintValidators (eg. in spring and hibernate).

The @NotNull annotation doesn't do any validation on its own because the annotation definition does not provide any ConstraintValidator type reference.

For more info see:

The SELECT permission was denied on the object 'Users', database 'XXX', schema 'dbo'

May be your Plesk panel or other panel subscription has been expired....please check subscription End.

Xcode warning: "Multiple build commands for output file"

Open the Frameworks folder in your project and make sure there are only frameworks inside. I added by mistake the whole Developer folder!

error: Unable to find vcvarsall.bat

I spent almost 2 days figuring out how to fix this problem in my python 3.4 64 bit version: Python 3.4.3 (v3.4.3:9b73f1c3e601, Feb 24 2015, 22:44:40) [MSC v.1600 64 bit (AMD64)] on win32

Solution 1, hard: (before reading this, read first Solution 2 below) Finally, this is what helped me:

install Visual C++ 2010 Express
install Microsoft Windows SDK v7.1 for Windows 7
create manually file vcvars64.bat in C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\bin\amd64 which contains CALL "C:\Program Files\Microsoft SDKs\Windows\v7.1\Bin\SetEnv.cmd" /x64 or other path depending on where you have yours installed
(this seems to be optional) install Microsoft Visual Studio 2010 Service Pack 1 together with Microsoft Visual C++ 2010 Service Pack 1 Compiler Update for the Windows SDK 7.1

after that I tried to pip install numpy but received the following error:

File "numpy\core\setup.py", line 686, in get_mathlib_info
raise RuntimeError("Broken toolchain: cannot link a simple C program")
RuntimeError: Broken toolchain: cannot link a simple C program

I changed mfinfo to None in C:\Python34\Lib\distutils\msvc9compiler.py per this https://stackoverflow.com/a/23099820/4383472

finally after pip install numpy command my avast antivirus tried to interfere into the installation process, but i quickly disabled it

It took very long - several minutes for numpy to compile, I even thought that there was an error, but finally everything was ok.

Solution 2, easy: (I know this approach has already been mentioned in a highly voted answer, but let me repeat since it really is easier) After going through all of this work I understood that the best way for me is just to use already precompiled binaries from http://www.lfd.uci.edu/~gohlke/pythonlibs/ in future. There is very small chance that I will ever need some package (or a version of a package) which this site doesn't contain. The installation process is also much quicker this way. For example, to install numpy:

donwload numpy-1.9.2+mkl-cp34-none-win_amd64.whl (if you have Python 3.4 64-bit) from that site
in command prompt or powershell install it with pip pip install numpy-1.9.2+mkl-cp34-none-win_amd64.whl (or full path to the file depending how command prompt is opened)

Get nodes where child node contains an attribute

Try to use this xPath expression:

//book/title[@lang='it']/..

That should give you all book nodes in "it" lang

Get value from input (AngularJS)

If you want to get values in Javascript on frontend, you can use the native way to do it by using :

document.getElementsByName("movie")[0].value;

Where "movie" is the name of your input <input type="text" name="movie">

If you want to get it on angular.js controller, you can use;

$scope.movie

ValidateRequest="false" doesn't work in Asp.Net 4

There is a way to turn the validation back to 2.0 for one page. Just add the below code to your web.config:

<configuration>
    <location path="XX/YY">
        <system.web>
            <httpRuntime requestValidationMode="2.0" />
        </system.web>
    </location>

    ...
    the rest of your configuration
    ...

</configuration>

How to remove a package in sublime text 2

Sublime Text 3

Procedure

Run Sublime Text.

Select Preferences ? Package Control.

Use ctrl+shift+p shortcut for (Win, Linux) or cmd+shift+p for (OS X).

Select Remove Package. Package Control: Remove Package

Start typing name of the package you want to remove and select it from the list of installed packages.

Wait for the uninstallation to complete.

Is it possible to write to the console in colour in .NET?

Yes, it is possible as follows. These colours can be used in a console application to view some errors in red, etc.

Console.BackgroundColor = ConsoleColor.Blue;
Console.ForegroundColor = ConsoleColor.White;//after this line every text will be white on blue background
Console.WriteLine("White on blue.");
Console.WriteLine("Another line.");
Console.ResetColor();//reset to the defoult colour

PHP Fatal error: Class 'PDO' not found

If you have upgraded your PHP version, make sure that the old PHP version configuration in your .htaccess has been deleted. For more info, check this https://www.hostgator.com/help/article/php-configuration-plugin

Programs & Examples On #Delphi prism

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