Programs & Examples On #Away3d

Away3D is an open-source real-time 3D engine for the Adobe Flash Platform.

What exactly should be set in PYTHONPATH?

For most installations, you should not set these variables since they are not needed for Python to run. Python knows where to find its standard library.

The only reason to set PYTHONPATH is to maintain directories of custom Python libraries that you do not want to install in the global default location (i.e., the site-packages directory).

Make sure to read: http://docs.python.org/using/cmdline.html#environment-variables

SVN commit command

To add a file/folder to the project, a good way is:

First of all add your files to /path/to/your/project/my/added/files, and then run following commands:

svn cleanup  /path/to/your/project

svn add --force /path/to/your/project/*

svn cleanup  /path/to/your/project

svn commit /path/to/your/project  -m 'Adding a file'

I used cleanup to prevent any segmentation fault (core dumped), and now the SVN project is updated.

How do I create a datetime in Python from milliseconds?

Bit heavy because of using pandas but works:

import pandas as pd
pd.to_datetime(msec_from_java, unit='ms').to_pydatetime()

Swift - How to detect orientation changes

??Device Orientation != Interface Orientation??

Swift 5.* iOS14 and below

You should really make a difference between:

  • Device Orientation => Indicates the orientation of the physical device
  • Interface Orientation => Indicates the orientation of the interface displayed on the screen

There are many scenarios where those 2 values are mismatching such as:

  • When you lock your screen orientation
  • When you have your device flat

In most cases you would want to use the interface orientation and you can get it via the window:

private var windowInterfaceOrientation: UIInterfaceOrientation? {
    return UIApplication.shared.windows.first?.windowScene?.interfaceOrientation
}

In case you also want to support < iOS 13 (such as iOS 12) you would do the following:

private var windowInterfaceOrientation: UIInterfaceOrientation? {
    if #available(iOS 13.0, *) {
        return UIApplication.shared.windows.first?.windowScene?.interfaceOrientation
    } else {
        return UIApplication.shared.statusBarOrientation
    }
}

Now you need to define where to react to the window interface orientation change. There are multiple ways to do that but the optimal solution is to do it within willTransition(to newCollection: UITraitCollection.

This inherited UIViewController method which can be overridden will be trigger every time the interface orientation will be change. Consequently you can do all your modifications in the latter.

Here is a solution example:

class ViewController: UIViewController {
    override func willTransition(to newCollection: UITraitCollection, with coordinator: UIViewControllerTransitionCoordinator) {
        super.willTransition(to: newCollection, with: coordinator)
        
        coordinator.animate(alongsideTransition: { (context) in
            guard let windowInterfaceOrientation = self.windowInterfaceOrientation else { return }
            
            if windowInterfaceOrientation.isLandscape {
                // activate landscape changes
            } else {
                // activate portrait changes
            }
        })
    }
    
    private var windowInterfaceOrientation: UIInterfaceOrientation? {
        return UIApplication.shared.windows.first?.windowScene?.interfaceOrientation
    }
}

By implementing this method you'll then be able to react to any change of orientation to your interface. But keep in mind that it won't be triggered at the opening of the app so you will also have to manually update your interface in viewWillAppear().

I've created a sample project which underlines the difference between device orientation and interface orientation. Additionally it will help you to understand the different behavior depending on which lifecycle step you decide to update your UI.

Feel free to clone and run the following repository: https://github.com/wjosset/ReactToOrientation

Show all current locks from get_lock

I found following way which can be used if you KNOW name of lock

select IS_USED_LOCK('lockname');

however i not found any info about how to list all names.

How to HTML encode/escape a string? Is there a built-in?

Checkout the Ruby CGI class. There are methods to encode and decode HTML as well as URLs.

CGI::escapeHTML('Usage: foo "bar" <baz>')
# => "Usage: foo &quot;bar&quot; &lt;baz&gt;"

How to clear all inputs, selects and also hidden fields in a form using jQuery?

If you want to apply clear value to a specific number of fields, then assign id or class to them and apply empty value to them. like this:

$('.all_fields').val('');

where all_fields is class applied to desired input fields for applying empty values. It will protect other fields to be empty, that you don't want to change.

How can I update npm on Windows?

For NodeJS

Download required node version msi from here and install

for Npm

Run PowerShell as Administrator

Set-ExecutionPolicy Unrestricted -Scope CurrentUser -Force
npm install -g npm-windows-upgrade
npm-windows-upgrade

Adb Devices can't find my phone

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

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

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

Remove blank attributes from an Object in Javascript

Recursively remove null, undefined, empty objects and empty arrays, returning a copy (ES6 version)

export function skipEmpties(dirty) {
    let item;
    if (Array.isArray(dirty)) {
        item = dirty.map(x => skipEmpties(x)).filter(value => value !== undefined);
        return item.length ? item : undefined;
    } else if (dirty && typeof dirty === 'object') {
        item = {};
        Object.keys(dirty).forEach(key => {
            const value = skipEmpties(dirty[key]);
            if (value !== undefined) {
                item[key] = value;
            }
        });
        return Object.keys(item).length ? item : undefined;
    } else {
        return dirty === null ? undefined : dirty;
    }
}

LINQ to SQL: Multiple joins ON multiple Columns. Is this possible?

You can write your query like this.

var query = from t1 in myTABLE1List // List<TABLE_1>
            join t2 in myTABLE1List
               on t1.ColumnA equals t2.ColumnA
               and t1.ColumnB equals t2.ColumnA

If you want to compare your column with multiple columns.

How to suspend/resume a process in Windows?

#pragma comment(lib,"ntdll.lib")
EXTERN_C NTSTATUS NTAPI NtSuspendProcess(IN HANDLE ProcessHandle);

void SuspendSelf(){
    NtSuspendProcess(GetCurrentProcess());
}

ntdll contains the exported function NtSuspendProcess, pass the handle to a process to do the trick.

Hibernate Query By Example and Projections

Can I see your User class? This is just using restrictions below. I don't see why Restrictions would be really any different than Examples (I think null fields get ignored by default in examples though).

getCurrentSession().createCriteria(User.class)
.setProjection( Projections.distinct( Projections.projectionList()
.add( Projections.property("name"), "name")
.add( Projections.property("city"), "city")))
.add( Restrictions.eq("city", "TEST")))
.setResultTransformer(Transformers.aliasToBean(User.class))
.list();

I've never used the alaistToBean, but I just read about it. You could also just loop over the results..

List<Object> rows = criteria.list();
for(Object r: rows){
  Object[] row = (Object[]) r;
  Type t = ((<Type>) row[0]);
}

If you have to you can manually populate User yourself that way.

Its sort of hard to look into the issue without some more information to diagnose the issue.

Xcode Project vs. Xcode Workspace - Differences

I think there are three key items you need to understand regarding project structure: Targets, projects, and workspaces. Targets specify in detail how a product/binary (i.e., an application or library) is built. They include build settings, such as compiler and linker flags, and they define which files (source code and resources) actually belong to a product. When you build/run, you always select one specific target.

It is likely that you have a few targets that share code and resources. These different targets can be slightly different versions of an app (iPad/iPhone, different brandings,…) or test cases that naturally need to access the same source files as the app. All these related targets can be grouped in a project. While the project contains the files from all its targets, each target picks its own subset of relevant files. The same goes for build settings: You can define default project-wide settings in the project, but if one of your targets needs different settings, you can always override them there:

Shared project settings that all targets inherit, unless they overwrite it

Shared project settings that all targets inherit, unless they override it

Concrete target settings: PSE iPhone overwrites the project’s Base SDK setting

Concrete target settings: PSE iPhone overrides the project’s Base SDK setting

In Xcode, you always open projects (or workspaces, but not targets), and all the targets it contains can be built/run, but there’s no way/definition of building a project, so every project needs at least one target in order to be more than just a collection of files and settings.

Select one of the project’s targets to run

Select one of the project’s targets to run

In a lot of cases, projects are all you need. If you have a dependency that you build from source, you can embed it as a subproject. Subprojects can be opened separately or within their super project.

demoLib is a subprojec

demoLib is a subproject

If you add one of the subproject’s targets to the super project’s dependencies, the subproject will be automatically built unless it has remained unchanged. The advantage here is that you can edit files from both your project and your dependencies in the same Xcode window, and when you build/run, you can select from the project’s and its subprojects’ targets:

Running targets from a subproject

If, however, your library (the subproject) is used by a variety of other projects (or their targets, to be precise), it makes sense to put it on the same hierarchy level – that’s what workspaces are for. Workspaces contain and manage projects, and all the projects it includes directly (i.e., not their subprojects) are on the same level and their targets can depend on each other (projects’ targets can depend on subprojects’ targets, but not vice versa).

Workspace structure

Workspace structure

In this example, both apps (AnotherApplication / ProjectStructureExample) can reference the demoLib project’s targets. This would also be possible by including the demoLib project in both other projects as a subproject (which is a reference only, so no duplication necessary), but if you have lots of cross-dependencies, workspaces make more sense. If you open a workspace, you can choose from all projects’ targets when building/running.

Running targets from a workspace

You can still open your project files separately, but it is likely their targets won’t build because Xcode cannot resolve the dependencies unless you open the workspace file. Workspaces give you the same benefit as subprojects: Once a dependency changes, Xcode will rebuild it to make sure it’s up-to-date (although I have had some issues with that, it doesn’t seem to work reliably).

Your questions in a nutshell:

1) Projects contain files (code/resouces), settings, and targets that build products from those files and settings. Workspaces contain projects which can reference each other.

2) Both are responsible for structuring your overall project, but on different levels.

3) I think projects are sufficient in most cases. Don’t use workspaces unless there’s a specific reason. Plus, you can always embed your project in a workspace later.

4) I think that’s what the above text is for…

There’s one remark for 3): CocoaPods, which automatically handles 3rd party libraries for you, uses workspaces. Therefore, you have to use them, too, when you use CocoaPods (which a lot of people do).

Timeout jQuery effects

This can be done with only a few lines of jQuery:

$(function(){
    // make sure img is hidden - fade in
    $('img').hide().fadeIn(2000);

    // after 5 second timeout - fade out
    setTimeout(function(){$('img').fadeOut(2000);}, 5000);
});?

see the fiddle below for a working example...

http://jsfiddle.net/eNxuJ/78/

Copy Files from Windows to the Ubuntu Subsystem

You should be able to access your windows system under the /mnt directory. For example inside of bash, use this to get to your pictures directory:

cd /mnt/c/Users/<ubuntu.username>/Pictures

Hope this helps!

Convert object to JSON string in C#

I have used Newtonsoft JSON.NET (Documentation) It allows you to create a class / object, populate the fields, and serialize as JSON.

public class ReturnData 
{
    public int totalCount { get; set; }
    public List<ExceptionReport> reports { get; set; }  
}

public class ExceptionReport
{
    public int reportId { get; set; }
    public string message { get; set; }  
}


string json = JsonConvert.SerializeObject(myReturnData);

What is the difference between "Form Controls" and "ActiveX Control" in Excel 2010?

One major difference that is important to know is that ActiveX controls show up as objects that you can use in your code- try inserting an ActiveX control into a worksheet, bring up the VBA editor (ALT + F11) and you will be able to access the control programatically. You can't do this with form controls (macros must instead be explicitly assigned to each control), but form controls are a little easier to use. If you are just doing something simple, it doesn't matter which you use but for more advanced scripts ActiveX has better possibilities.

ActiveX is also more customizable.

How to add a scrollbar to an HTML5 table?

You can use a division class with the overflow attribute using the value scroll. Or you can enclose the table inside an iframe. The iframe works well with old and new IE browsers, but it may not work with other browsers and probably not with the latest IE.

 #myid { overflow-x: scroll; overflow-y: hide; width:200px; /* Or whatever the amount of pixels */ }
.myid { overflow-x: scroll; overflow-y: hide; width:200px; /* Or whatever the amount of pixels */ }

<div class="myid">
     <div class="row">Content1</div>
     <div class="row2">Content2</div>
</div>

<table id="myid"><tr><td>Content</td></tr></table>

C# Get a control's position on a form

You could walk up through the parents, noting their position within their parent, until you arrive at the Form.

Edit: Something like (untested):

public Point GetPositionInForm(Control ctrl)
{
   Point p = ctrl.Location;
   Control parent = ctrl.Parent;
   while (! (parent is Form))
   {
      p.Offset(parent.Location.X, parent.Location.Y);
      parent = parent.Parent;
   }
   return p;
}

Backporting Python 3 open(encoding="utf-8") to Python 2

1. To get an encoding parameter in Python 2:

If you only need to support Python 2.6 and 2.7 you can use io.open instead of open. io is the new io subsystem for Python 3, and it exists in Python 2,6 ans 2.7 as well. Please be aware that in Python 2.6 (as well as 3.0) it's implemented purely in python and very slow, so if you need speed in reading files, it's not a good option.

If you need speed, and you need to support Python 2.6 or earlier, you can use codecs.open instead. It also has an encoding parameter, and is quite similar to io.open except it handles line-endings differently.

2. To get a Python 3 open() style file handler which streams bytestrings:

open(filename, 'rb')

Note the 'b', meaning 'binary'.

Access IP Camera in Python OpenCV

Getting the correct URL for your camera seems to be the actual challenge! I'm putting my working URL here, it might help someone. The camera is EZVIZ C1C with exact model cs-c1c-d0-1d2wf. The working URL is

rtsp://admin:[email protected]/h264_stream

where SZGBZT is the verification code found at the bottom of the camera. admin is always admin regardless of any settings or users you have.

The final code will be

video_capture = cv2.VideoCapture('rtsp://admin:[email protected]/h264_stream')

Could not load file or assembly System.Net.Http, Version=4.0.0.0 with ASP.NET (MVC 4) Web API OData Prerelease

Visual Studio 2013 has a new feature to take care of this. When you build the app, you should see warnings about different versions of an assembly being referenced. Double click the warning to add assembly binding redirects to the web.config.

See http://msdn.microsoft.com/en-us/library/2fc472t2.aspx for more details.

jeff.eynon notes below that you need to have the web.config checked out (if using TFS source control) to get VS to edit the file automatically. Thanks for the tip!

Javascript date.getYear() returns 111 in 2011?

https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Date/getYear

getYear is no longer used and has been replaced by the getFullYear method.

The getYear method returns the year minus 1900; thus:

  • For years greater than or equal to 2000, the value returned by getYear is 100 or greater. For example, if the year is 2026, getYear returns 126.
  • For years between and including 1900 and 1999, the value returned by getYear is between 0 and 99. For example, if the year is 1976, getYear returns 76.
  • For years less than 1900, the value returned by getYear is less than 0. For example, if the year is 1800, getYear returns -100.
  • To take into account years before and after 2000, you should use getFullYear instead of getYear so that the year is specified in full.

javascript: Disable Text Select

I'm writing slider ui control to provide drag feature, this is my way to prevent content from selecting when user is dragging:

function disableSelect(event) {
    event.preventDefault();
}

function startDrag(event) {
    window.addEventListener('mouseup', onDragEnd);
    window.addEventListener('selectstart', disableSelect);
    // ... my other code
}

function onDragEnd() {
    window.removeEventListener('mouseup', onDragEnd);
    window.removeEventListener('selectstart', disableSelect);
    // ... my other code
}

bind startDrag on your dom:

<button onmousedown="startDrag">...</button>

If you want to statically disable text select on all element, execute the code when elements are loaded:

window.addEventListener('selectstart', function(e){ e.preventDefault(); });

      

How to see what privileges are granted to schema of another user

Use example with from the post of Szilágyi Donát.

I use two querys, one to know what roles I have, excluding connect grant:

SELECT * FROM USER_ROLE_PRIVS WHERE GRANTED_ROLE != 'CONNECT'; -- Roles of the actual Oracle Schema

Know I like to find what privileges/roles my schema/user have; examples of my roles ROLE_VIEW_PAYMENTS & ROLE_OPS_CUSTOMERS. But to find the tables/objecst of an specific role I used:

SELECT * FROM ALL_TAB_PRIVS WHERE GRANTEE='ROLE_OPS_CUSTOMERS'; -- Objects granted at role.

The owner schema for this example could be PRD_CUSTOMERS_OWNER (or the role/schema inself).

Regards.

How to execute function in SQL Server 2008

It looks like there's something else called Afisho_rankimin in your DB so the function is not being created. Try calling your function something else. E.g.

CREATE FUNCTION dbo.Afisho_rankimin1(@emri_rest int)
RETURNS int
AS
   BEGIN
       Declare @rankimi int
       Select @rankimi=dbo.RESTORANTET.Rankimi
       From RESTORANTET
       Where  dbo.RESTORANTET.ID_Rest=@emri_rest
       RETURN @rankimi
  END
  GO

Note that you need to call this only once, not every time you call the function. After that try calling

SELECT dbo.Afisho_rankimin1(5) AS Rankimi 

How to run function of parent window when child window closes?

You probably want to use the 'onbeforeunload' event. It will allow you call a function in the parent window from the child immediately before the child window closes.

So probably something like this:

window.onbeforeunload = function (e) {
    window.parent.functonToCallBeforeThisWindowCloses();
};

How to convert 'binary string' to normal string in Python3?

If the answer from falsetru didn't work you could also try:

>>> b'a string'.decode('utf-8')
'a string'

How can I execute a PHP function in a form action?

It's better something like this...post the data to the self page and maybe do a check on user input.

   <?php
    require_once ( 'username.php' );

    if(isset($_POST)) {
      echo "form post"; // ex $_POST['textfield']
    }


    echo '
    <form name="form1" method="post" action="' . $_SERVER['PHP_SELF'] . '">
      <p>
        <label>
          <input type="text" name="textfield" id="textfield">
        </label>
      </p>
      <p>
        <label>
          <input type="submit" name="button" id="button" value="Submit">
        </label>
      </p>
    </form>';
    ?>

react-router scroll to top on every transition

In your router.js, just add this function in the router object. This will do the job.

scrollBehavior() {
        document.getElementById('app').scrollIntoView();
    },

Like this,

**Routes.js**

import vue from 'blah!'
import Router from 'blah!'

let router = new Router({
    mode: 'history',
    base: process.env.BASE_URL,
    scrollBehavior() {
        document.getElementById('app').scrollIntoView();
    },
    routes: [
            { url: "Solar System" },
            { url: "Milky Way" },
            { url: "Galaxy" },
    ]
});

How do I include a Perl module that's in a different directory?

I'm surprised nobody has mentioned it before, but FindBin::libs will always find your libs as it searches in all reasonable places relative to the location of your script.

#!/usr/bin/perl
use FindBin::libs;
use <your lib>;

Anaconda Installed but Cannot Launch Navigator

100% Solved. While Installing make sure you are connected to Internet. If already installed anaconda, open the anaconda command prompt and type following command:

conda install -c anaconda anaconda-navigator
(internet connection is required)

Note: In some cases restarting may solve the issue of navigator.

How to drop rows from pandas data frame that contains a particular string in a particular column?

If your string constraint is not just one string you can drop those corresponding rows with:

df = df[~df['your column'].isin(['list of strings'])]

The above will drop all rows containing elements of your list

jQuery DatePicker with today as maxDate

For those who dont want to use datepicker method

var alldatepicker=  $("[class$=hasDatepicker]");

alldatepicker.each(function(){

var value=$(this).val();

var today = new Date();

var dd = today.getDate();

var mm = today.getMonth()+1; //January is 0!

var yyyy = today.getFullYear();

if(dd<10) {

    dd='0'+dd

} 
if(mm<10) {

    mm='0'+mm

} 
today = mm+'/'+dd+'/'+yyyy;
if(value!=''){
if(value>today){
alert("Date cannot be greater than current date");
}
}
}); 

ASP MVC href to a controller/view

Try the following:

<a asp-controller="Users" asp-action="Index"></a>

(Valid for ASP.NET 5 and MVC 6)

How to load Spring Application Context

I am using in the way and it is working for me.

public static void main(String[] args) {
    new CarpoolDBAppTest();

}

public CarpoolDBAppTest(){
    ApplicationContext context = new ClassPathXmlApplicationContext("application-context.xml");
    Student stud = (Student) context.getBean("yourBeanId");
}

Here Student is my classm you will get the class matching yourBeanId.

Now work on that object with whatever operation you want to do.

Javascript Get Element by Id and set the value

If myFunc(variable) is executed before textarea is rendered to page, you will get the null exception error.

<html>
    <head>
    <title>index</title>
    <script type="text/javascript">
        function myFunc(variable){
            var s = document.getElementById(variable);
            s.value = "new value";
        }   
        myFunc("id1");
    </script>
    </head>
    <body>
        <textarea id="id1"></textarea>
    </body>
</html>
//Error message: Cannot set property 'value' of null 

So, make sure your textarea does exist in the page, and then call myFunc, you can use window.onload or $(document).ready function. Hope it's helpful.

Android SDK is missing, out of date, or is missing templates. Please ensure you are using SDK version 22 or later

If Android Studio directly opening your project instead of setup window, then just close the windows of all projects. Now you will able to see the startup window. If SDK is missing then it will provide option to download SDK and other required tools.

It works for me.

fopen deprecated warning

I also got the same problem. When I try to add the opencv library

#include <opencv\cv.h>

I got not a warning but an error.

error C4996: 'fopen': This function or variable may be unsafe. Consider using fopen_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.    c:\program files (x86)\opencv\build\include\opencv2\flann\logger.h  

I also used the preprocessor directives as mentioned. But that didn't solve the problem.

I solved it by doing as follows:

  • Go to Properties -> C/C++ -> Precompiled Headers -> Choose Not Using Precompiled Headers in Precompiled Header.

Writing unit tests in Python: How do I start?

The free Python book Dive Into Python has a chapter on unit testing that you might find useful.

If you follow modern practices you should probably write the tests while you are writing your project, and not wait until your project is nearly finished.

Bit late now, but now you know for next time. :)

How can I suppress column header output for a single SQL statement?

Invoke mysql with the -N (the alias for -N is --skip-column-names) option:

mysql -N ...
use testdb;
select * from names;

+------+-------+
|    1 | pete  |
|    2 | john  |
|    3 | mike  |
+------+-------+
3 rows in set (0.00 sec)

Credit to ErichBSchulz for pointing out the -N alias.

To remove the grid (the vertical and horizontal lines) around the results use -s (--silent). Columns are separated with a TAB character.

mysql -s ...
use testdb;
select * from names;

id  name
1   pete
2   john
3   mike

To output the data with no headers and no grid just use both -s and -N.

mysql -sN ...

"error: assignment to expression with array type error" when I assign a struct field (C)

typedef struct{
     char name[30];
     char surname[30];
     int age;
} data;

defines that data should be a block of memory that fits 60 chars plus 4 for the int (see note)

[----------------------------,------------------------------,----]
 ^ this is name              ^ this is surname              ^ this is age

This allocates the memory on the stack.

data s1;

Assignments just copies numbers, sometimes pointers.

This fails

s1.name = "Paulo";

because the compiler knows that s1.name is the start of a struct 64 bytes long, and "Paulo" is a char[] 6 bytes long (6 because of the trailing \0 in C strings)
Thus, trying to assign a pointer to a string into a string.

To copy "Paulo" into the struct at the point name and "Rossi" into the struct at point surname.

memcpy(s1.name,    "Paulo", 6);
memcpy(s1.surname, "Rossi", 6);
s1.age = 1;

You end up with

[Paulo0----------------------,Rossi0-------------------------,0001]

strcpy does the same thing but it knows about \0 termination so does not need the length hardcoded.

Alternatively you can define a struct which points to char arrays of any length.

typedef struct {
  char *name;
  char *surname;
  int age;
} data;

This will create

[----,----,----]

This will now work because you are filling the struct with pointers.

s1.name = "Paulo";
s1.surname = "Rossi";
s1.age = 1;

Something like this

[---4,--10,---1]

Where 4 and 10 are pointers.

Note: the ints and pointers can be different sizes, the sizes 4 above are 32bit as an example.

Equivalent of Super Keyword in C#

C# equivalent of your code is

  class Imagedata : PDFStreamEngine
  {
     // C# uses "base" keyword whenever Java uses "super" 
     // so instead of super(...) in Java we should call its C# equivalent (base):
     public Imagedata()
       : base(ResourceLoader.loadProperties("org/apache/pdfbox/resources/PDFTextStripper.properties", true)) 
     { }

     // Java methods are virtual by default, when C# methods aren't.
     // So we should be sure that processOperator method in base class 
     // (that is PDFStreamEngine)
     // declared as "virtual"
     protected override void processOperator(PDFOperator operations, List arguments)
     {
        base.processOperator(operations, arguments);
     }
  }

What does OpenCV's cvWaitKey( ) function do?

Plain simply, cvWaitKey() sleeps for X miliseconds, waiting for any key to be pressed.

int cvWaitKey(int X);

If a key is pressed, this function returns the ASCII code of key. Or returns -1 if no keys were pressed during that time.

Convert UTF-8 with BOM to UTF-8 with no BOM in Python

I found this question because having trouble with configparser.ConfigParser().read(fp) when opening files with UTF8 BOM header.

For those who are looking for a solution to remove the header so that ConfigPhaser could open the config file instead of reporting an error of: File contains no section headers, please open the file like the following:

configparser.ConfigParser().read(config_file_path, encoding="utf-8-sig")

This could save you tons of effort by making the remove of the BOM header of the file unnecessary.

(I know this sounds unrelated, but hopefully this could help people struggling like me.)

Setting a spinner onClickListener() in Android

The Spinner class implements DialogInterface.OnClickListener, thereby effectively hijacking the standard View.OnClickListener.

If you are not using a sub-classed Spinner or don't intend to, choose another answer.

Otherwise just add the following code to your custom Spinner:

@Override
/** Override triggered on 'tap' of closed Spinner */
public boolean performClick() {
    // [ Do anything you like here ]
    return super.performClick();
}

Example: Display a pre-supplied hint via Snackbar whenever the Spinner is opened:

private String sbMsg=null;      // Message seen by user when Spinner is opened.
public void setSnackbarMessage(String msg) { sbMsg=msg; }
@Override
/** Override triggered on 'tap' of closed Spinner */
public boolean performClick() {
    if (sbMsg!=null && !sbMsg.isEmpty()) { /* issue Snackbar */ }
    return super.performClick();
}

Trapping 'click' of closed Spinner

A custom Spinner is a terrific starting point for programmatically standardising Spinner appearance throughout your project.

If interested, looky here

What reference do I need to use Microsoft.Office.Interop.Excel in .NET?

Make sure your project is 32 bit.

I had this problem, as soon as I ticked "Prefer 32 bit and rebuilt" all the Office Interop assemblies where available in Reference->Assemblies->Search "Office".

Django DB Settings 'Improperly Configured' Error

For people using IntelliJ, with these settings I was able to query from the shell (on windows).

enter image description here

Simple if else onclick then do?

you call function on page load time but not call on button event, you will need to call function onclick event, you may add event inline element style or event bining

_x000D_
_x000D_
 function Choice(elem) {_x000D_
   var box = document.getElementById("box");_x000D_
   if (elem.id == "no") {_x000D_
     box.style.backgroundColor = "red";_x000D_
   } else if (elem.id == "yes") {_x000D_
     box.style.backgroundColor = "green";_x000D_
   } else {_x000D_
     box.style.backgroundColor = "purple";_x000D_
   };_x000D_
 };
_x000D_
<div id="box">dd</div>_x000D_
<button id="yes" onclick="Choice(this);">yes</button>_x000D_
<button id="no" onclick="Choice(this);">no</button>_x000D_
<button id="other" onclick="Choice(this);">other</button>
_x000D_
_x000D_
_x000D_

or event binding,

_x000D_
_x000D_
window.onload = function() {_x000D_
  var box = document.getElementById("box");_x000D_
  document.getElementById("yes").onclick = function() {_x000D_
    box.style.backgroundColor = "red";_x000D_
  }_x000D_
  document.getElementById("no").onclick = function() {_x000D_
    box.style.backgroundColor = "green";_x000D_
  }_x000D_
}
_x000D_
<div id="box">dd</div>_x000D_
<button id="yes">yes</button>_x000D_
<button id="no">no</button>
_x000D_
_x000D_
_x000D_

Android Completely transparent Status Bar?

Simple and crisp and works with almost all use cases (for API level 16 and above):

  1. Use the following tag in your app theme to make the status bar transparent:

    <item name="android:statusBarColor">@android:color/transparent</item>

  2. And then use this code in your activity's onCreate method.

    View decorView = getWindow().getDecorView();
    decorView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE
            | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
    

That's all you need to do ;)

You can learn more from the developer documentation. I'd also recommend reading this blog post.

KOTLIN CODE:

    val decorView = window.decorView
    decorView.systemUiVisibility = (View.SYSTEM_UI_FLAG_LAYOUT_STABLE
            or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN)

Check my another answer here

JQuery: detect change in input field

Same functionality i recently achieved using below function.

I wanted to enable SAVE button on edit.

  1. Change event is NOT advisable as it will ONLY be fired if after editing, mouse is clicked somewhere else on the page before clicking SAVE button.
  2. Key Press doesnt handle Backspace, Delete and Paste options.
  3. Key Up handles everything including tab, Shift key.

Hence i wrote below function combining keypress, keyup (for backspace, delete) and paste event for text fields.

Hope it helps you.

function checkAnyFormFieldEdited() {
    /*
     * If any field is edited,then only it will enable Save button
     */
    $(':text').keypress(function(e) { // text written
        enableSaveBtn();
    });

    $(':text').keyup(function(e) {
        if (e.keyCode == 8 || e.keyCode == 46) { //backspace and delete key
            enableSaveBtn();
        } else { // rest ignore
            e.preventDefault();
        }
    });
    $(':text').bind('paste', function(e) { // text pasted
        enableSaveBtn();
    });

    $('select').change(function(e) { // select element changed
        enableSaveBtn();
    });

    $(':radio').change(function(e) { // radio changed
        enableSaveBtn();
    });

    $(':password').keypress(function(e) { // password written
        enableSaveBtn();
    });
    $(':password').bind('paste', function(e) { // password pasted
        enableSaveBtn();
    });


}

Getting a "This application is modifying the autolayout engine from a background thread" error?

When you try to update a text field value or adding a subview inside a background thread, you can get this problem. For that reason, you should put this kind of code in the main thread.

You need to wrap methods that call UI updates with dispatch_asynch to get the main queue. For example:

dispatch_async(dispatch_get_main_queue(), { () -> Void in
   self.friendLabel.text = "You are following \(friendCount) accounts"
})

EDITED - SWIFT 3:

Now, we can do that following the next code:

// Move to a background thread to do some long running work
DispatchQueue.global(qos: .userInitiated).async {
   // Do long running task here
   // Bounce back to the main thread to update the UI
   DispatchQueue.main.async {
      self.friendLabel.text = "You are following \(friendCount) accounts"
   }
}

The proxy server received an invalid response from an upstream server

This is not mentioned in you post but I suspect you are initiating an SSL connection from the browser to Apache, where VirtualHosts are configured, and Apache does a revese proxy to your Tomcat.

There is a serious bug in (some versions ?) of IE that sends the 'wrong' host information in an SSL connection (see EDIT below) and confuses the Apache VirtualHosts. In short the server name presented is the one of the reverse DNS resolution of the IP, not the one in the URL.

The workaround is to have one IP address per SSL virtual hosts/server name. Is short, you must end up with something like

1 server name == 1 IP address == 1 certificate == 1 Apache Virtual Host

EDIT

Though the conclusion is correct, the identification of the problem is better described here http://en.wikipedia.org/wiki/Server_Name_Indication

Display animated GIF in iOS

FLAnimatedImage is a performant open source animated GIF engine for iOS:

  • Plays multiple GIFs simultaneously with a playback speed comparable to desktop browsers
  • Honors variable frame delays
  • Behaves gracefully under memory pressure
  • Eliminates delays or blocking during the first playback loop
  • Interprets the frame delays of fast GIFs the same way modern browsers do

It's a well-tested component that I wrote to power all GIFs in Flipboard.

Java: Getting a substring from a string starting after a particular character

I think that would be better if we use directly the split function

String toSplit = "/abc/def/ghfj.doc";

String result[] = toSplit.split("/");

String returnValue = result[result.length - 1]; //equals "ghfj.doc"

Git: Find the most recent common ancestor of two branches

git diff master...feature

shows all the new commits of your current (possibly multi-commit) feature branch.

man git-diff documents that:

git diff A...B

is the same as:

git diff $(git merge-base A B) B

but the ... is easier to type and remember.

As mentioned by Dave, the special case of HEAD can be omitted. So:

git diff master...HEAD

is the same as:

git diff master...

which is enough if the current branch is feature.

Finally, remember that order matters! Doing git diff feature...master will show changes that are on master not on feature.

I wish more git commands would support that syntax, but I don't think they do. And some even have different semantics for ...: What are the differences between double-dot ".." and triple-dot "..." in Git commit ranges?

Merging 2 branches together in GIT

Case: If you need to ignore the merge commit created by default, follow these steps.

Say, a new feature branch is checked out from master having 2 commits already,

  • "Added A" , "Added B"

Checkout a new feature_branch

  • "Added C" , "Added D"

Feature branch then adds two commits-->

  • "Added E", "Added F"

enter image description here

Now if you want to merge feature_branch changes to master, Do git merge feature_branch sitting on the master.

This will add all commits into master branch (4 in master + 2 in feature_branch = total 6) + an extra merge commit something like 'Merge branch 'feature_branch'' as the master is diverged.

If you really need to ignore these commits (those made in FB) and add the whole changes made in feature_branch as a single commit like 'Integrated feature branch changes into master', Run git merge feature_merge --no-commit.

With --no-commit, it perform the merge and stop just before creating a merge commit, We will have all the added changes in feature branch now in master and get a chance to create a new commit as our own.

Read here for more : https://git-scm.com/docs/git-merge

How to check for an empty struct?

Just a quick addition, because I tackled the same issue today:

With Go 1.13 it is possible to use the new isZero() method:

if reflect.ValueOf(session).IsZero() {
     // do stuff...
}

I didn't test this regarding performance, but I guess that this should be faster, than comparing via reflect.DeepEqual().

How to unlock a file from someone else in Team Foundation Server

Use the unlock command that comes with TFS

  1. Click Start, click All Programs, click Microsoft Visual Studio 2008, click Visual Studio Tools, and then click Visual Studio Command Prompt.
  2. Type the following command and replace the arguments with the appropriate parameter information for your needs: tf lock /lock:none $/MyTeamProject/web.config

    tf lock itemspec /lock:(none|checkout|checkin) [/workspace:workspacename] [/recursive] [/login:username,[password]] [/collection:TeamProjectCollectionUrl]

From MSDN.

gcloud command not found - while installing Google Cloud SDK

Post installation instructions are not clear:

==> Source [/.../google-cloud-sdk/completion.bash.inc] in your profile to enable shell command completion for gcloud.
==> Source [/.../google-cloud-sdk/path.bash.inc] in your profile to add the Google Cloud SDK command line tools to your $PATH.

I had to actually add the following lines of code in my .bash_profile for gcloud to work:

source '/.../google-cloud-sdk/completion.bash.inc'
source '/.../google-cloud-sdk/path.bash.inc'

How to float 3 divs side by side using CSS?

I didn't see the bootstrap answer, so for what's it's worth:

<div class="col-xs-4">Left Div</div>
<div class="col-xs-4">Middle Div</div>
<div class="col-xs-4">Right Div</div>
<br style="clear: both;" />

let Bootstrap figure out the percentages. I like to clear both, just in case.

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

$content = '';
    for($rowth=0; $rowth<=100; $rowth++){
        $content .= $selenium->getTable("tblReports.{$rowth}.0") . "\n";
        //$content .= $selenium->getTable("tblReports.{$rowth}.1") . "\n";
        $content .= $selenium->getTable("tblReports.{$rowth}.2") . " ";
        $content .= $selenium->getTable("tblReports.{$rowth}.3") . " ";
        $content .= $selenium->getTable("tblReports.{$rowth}.4") . " ";
        $content .= $selenium->getTable("tblReports.{$rowth}.5") . " ";
        $content .= $selenium->getTable("tblReports.{$rowth}.6") . "\n";

    }

Laravel Eloquent groupBy() AND also return count of each group

Try with this

->groupBy('state_id','locality')
  ->havingRaw('count > 1 ')
  ->having('items.name','LIKE',"%$keyword%")
  ->orHavingRaw('brand LIKE ?',array("%$keyword%"))

how to set the background color of the whole page in css

I already wrote up the answer to this but it seems to have been deleted. The issue was that YUI added background-color:white to the HTML element. I overwrote that and everything was easy to handle from there.

Dependent DLL is not getting copied to the build output folder in Visual Studio

I would do add it to Postbuild events to copy necessary libraries to the output directories. Something like XCopy pathtolibraries targetdirectory

You can find them on project properties -> Build Events.

Error handling with PHPMailer

$mail = new PHPMailer();

$mail->AddAddress($email); 
$mail->From     = $from;
$mail->Subject  = $subject; 
$mail->Body     = $body;

if($mail->Send()){
    echo 'Email Successfully Sent!';
}else{
    echo 'Email Sending Failed!';
}

the simplest way to handle email sending successful or failed...

What's the correct way to convert bytes to a hex string in Python 3?

New in python 3.8, you can pass a delimiter argument to the hex function, as in this example

>>> value = b'\xf0\xf1\xf2'
>>> value.hex('-')
'f0-f1-f2'
>>> value.hex('_', 2)
'f0_f1f2'
>>> b'UUDDLRLRAB'.hex(' ', -4)
'55554444 4c524c52 4142'

https://docs.python.org/3/library/stdtypes.html#bytes.hex

Multi-character constant warnings

If you're happy you know what you're doing and can accept the portability problems, on GCC for example you can disable the warning on the command line:

-Wno-multichar

I use this for my own apps to work with AVI and MP4 file headers for similar reasons to you.

Start script missing error when running npm start

I got this error because I wasn't in the right directory in terminal.

App with the scripts was in folder B. Folder B was in folder A. I open folder A in vscode and enter "npm run start" into the built in terminal and got the error. try "cd folder B", opening folder B in the ide, or organizing your stuff better than I did in the first place.

HTTP Content-Type Header and JSON

The below code helps me to return a JSON object for JavaScript on the front end

My template code

template_file.json

{
    "name": "{{name}}"
}

Python backed code

def download_json(request):
    print("Downloading JSON")
    # Response render a template as JSON object
    return HttpResponse(render_to_response("template_file.json",dict(name="Alex Vera")),content_type="application/json")    

File url.py

url(r'^download_as_json/$', views.download_json, name='download_json-url')

jQuery code for the front end

  $.ajax({
        url:'{% url 'download_json-url' %}'        
    }).done(function(data){
        console.log('json ', data);
        console.log('Name', data.name);
        alert('hello ' + data.name);
    });

How to fix Invalid AES key length?

You can verify the key length limit:

int maxKeyLen = Cipher.getMaxAllowedKeyLength("AES");
System.out.println("MaxAllowedKeyLength=[" + maxKeyLen + "].");

Difference between webdriver.Dispose(), .Close() and .Quit()

quit(): Quits this driver, closing every associated window that was open.

close() : Close the current window, quitting the browser if it's the last window currently open.

How can I make my layout scroll both horizontally and vertically?

I was able to find a simple way to achieve both scrolling behaviors.

Here is the xml for it:

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent" android:layout_height="fill_parent"
    android:scrollbars="vertical">

    <HorizontalScrollView 
        android:layout_width="320px" android:layout_height="fill_parent">

        <TableLayout
            android:id="@+id/linlay" android:layout_width="320px"
            android:layout_height="fill_parent" android:stretchColumns="1"
            android:background="#000000"/>

    </HorizontalScrollView>

</ScrollView>

PHP expects T_PAAMAYIM_NEKUDOTAYIM?

This is also coming when you apply a constant in PHP to the empty() function:

if (!empty(SOME_CONSTANT)) {

}

That was my case. I solved it by using this:

$string = SOME_CONSTANT;
if (!empty($string)) {

}

' << ' operator in verilog

<< is a binary shift, shifting 1 to the left 8 places.

4'b0001 << 1 => 4'b0010

>> is a binary right shift adding 0's to the MSB.
>>> is a signed shift which maintains the value of the MSB if the left input is signed.

4'sb1011 >>  1 => 0101
4'sb1011 >>> 1 => 1101

Three ways to indicate left operand is signed:

module shift;
  logic        [3:0] test1 = 4'b1000;
  logic signed [3:0] test2 = 4'b1000;

  initial begin
    $display("%b", $signed(test1) >>> 1 ); //Explicitly set as signed
    $display("%b", test2          >>> 1 ); //Declared as signed type
    $display("%b", 4'sb1000       >>> 1 ); //Signed constant
    $finish;
  end
endmodule

CakePHP find method with JOIN

        $services = $this->Service->find('all', array(
            'limit' =>4,
            'fields' => array('Service.*','ServiceImage.*'),
            'joins' => array(
                array(
                        'table' => 'services_images',
                        'alias' => 'ServiceImage',
                        'type' => 'INNER',
                        'conditions' => array(
                        'ServiceImage.service_id' =>'Service.id'
                        )
                    ),
                ),
            )
        );

It goges to array is null.

How do you test a public/private DSA keypair?

The check can be made easier with diff:

diff <(ssh-keygen -y -f $private_key_file) $public_key_file

The only odd thing is that diff says nothing if the files are the same, so you'll only be told if the public and private don't match.

Create, read, and erase cookies with jQuery

As I know, there is no direct support, but you can use plain-ol' javascript for that:

// Cookies
function createCookie(name, value, days) {
    if (days) {
        var date = new Date();
        date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
        var expires = "; expires=" + date.toGMTString();
    }
    else var expires = "";               

    document.cookie = name + "=" + value + expires + "; path=/";
}

function readCookie(name) {
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for (var i = 0; i < ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0) == ' ') c = c.substring(1, c.length);
        if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);
    }
    return null;
}

function eraseCookie(name) {
    createCookie(name, "", -1);
}

How to right-align and justify-align in Markdown?

If you want to use this answer, I found out that when you are using MacDown on MacOs, you can <div style="text-align: justify"> at the beginning of the document to justify all text and keep all code formating. Maybe it works on other editors too, for you to try ;)

Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. The statement has been terminated

TLDR:

  1. Rebooting both application and DB servers is the quickest fix where data volume, network settings and code haven't changed. We always do so as a rule
  2. May be indicator of failing hard-drive that needs replacement - check system notifications

I have often encountered this error for various reasons and have had various solutions, including:

  1. refactoring my code to use SqlBulkCopy
  2. increasing Timeout values, as stated in various answers or checking for underlying causes (may not be data related)
  3. Connection Timeout (Default 15s) - How long it takes to wait for a connection to be established with the SQL server before terminating - TCP/PORT related - can go through a troubleshooting checklist (very handy MSDN article)
  4. Command Timeout (Default 30s) - How long it takes to wait for the execution of a query - Query execution/network traffic related - also has a troubleshooting process (another very handy MSDN article)
  5. Rebooting of the server(s) - both application & DB Server (if separate) - where code and data haven't changed, environment must have changed - First thing you must do. Typically caused by patches (operating system, .Net Framework or SQL Server patches or updates). Particularly if timeout exception appears as below (even if we do not use Azure):
    • System.Data.Entity.Core.EntityException: An exception has been raised that is likely due to a transient failure. If you are connecting to a SQL Azure database consider using SqlAzureExecutionStrategy. ---> System.Data.Entity.Core.EntityCommandExecutionException: An error occurred while executing the command definition. See the inner exception for details. ---> System.Data.SqlClient.SqlException: A transport-level error has occurred when receiving results from the server. (provider: TCP Provider, error: 0 - The semaphore timeout period has expired.) ---> System.ComponentModel.Win32Exception: The semaphore timeout period has expired

Does Hibernate create tables in the database automatically

add following property in your hibernate.cfg.xml file

<property name="hibernate.hbm2ddl.auto">update</property>

BTW, in your Entity class, you must define your @Id filed like this:

@Id
@GeneratedValue(generator = "increment")
@GenericGenerator(name = "increment", strategy = "increment")
@Column(name = "id")
private long id;

if you use the following definition, it maybe not work:

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private long id;

Why did I get the compile error "Use of unassigned local variable"?

The following categories of variables are classified as initially unassigned:

  • Instance variables of initially unassigned struct variables.
  • Output parameters, including the this variable of struct instance constructors.
  • Local variables , except those declared in a catch clause or a foreach statement.

The following categories of variables are classified as initially assigned:

  • Static variables.
  • Instance variables of class instances.
  • Instance variables of initially assigned struct variables.
  • Array elements.
  • Value parameters.
  • Reference parameters.
  • Variables declared in a catch clause or a foreach statement.

How to get the first five character of a String

If we want only first 5 characters from any field, then this can be achieved by Left Attribute

Vessel = f.Vessel !=null ? f.Vessel.Left(5) : ""

Creating a Pandas DataFrame from a Numpy array: How do I specify the index column and column headers?

I think this is a simple and intuitive method:

data = np.array([[0, 0], [0, 1] , [1, 0] , [1, 1]])
reward = np.array([1,0,1,0])

dataset = pd.DataFrame()
dataset['StateAttributes'] = data.tolist()
dataset['reward'] = reward.tolist()

dataset

returns:

enter image description here

But there are performance implications detailed here:

How to set the value of a pandas column as list

List all the files and folders in a Directory with PHP recursive function

This will print the full path of all files in the given directory, you can also pass other callback functions to recursiveDir.

function printFunc($path){
    echo $path."<br>";
}

function recursiveDir($path, $fileFunc, $dirFunc){
    $openDir = opendir($path);
    while (($file = readdir($openDir)) !== false) {
        $fullFilePath = realpath("$path/$file");
        if ($file[0] != ".") {
            if (is_file($fullFilePath)){
                if (is_callable($fileFunc)){
                    $fileFunc($fullFilePath);
                }
            } else {
                if (is_callable($dirFunc)){
                    $dirFunc($fullFilePath);
                }
                recursiveDir($fullFilePath, $fileFunc, $dirFunc);
            }
        }
    }
}

recursiveDir($dirToScan, 'printFunc', 'printFunc');

Execute multiple command lines with the same process using .NET

You can redirect standard input and use a StreamWriter to write to it:

        Process p = new Process();
        ProcessStartInfo info = new ProcessStartInfo();
        info.FileName = "cmd.exe";
        info.RedirectStandardInput = true;
        info.UseShellExecute = false;

        p.StartInfo = info;
        p.Start();

        using (StreamWriter sw = p.StandardInput)
        {
            if (sw.BaseStream.CanWrite)
            {
                sw.WriteLine("mysql -u root -p");
                sw.WriteLine("mypassword");
                sw.WriteLine("use mydb;");
            }
        }

Getting today's date in YYYY-MM-DD in Python?

You can use,

>>> from datetime import date
>>> date.today().__str__()
'2019-10-05'

How to display Base64 images in HTML?

This will show image of base 64 data:

<style>
.logo {
      width: 290px;
      height: 63px;
      background: url(data:image/png;base64,copy-paste-base64-data-here) no-repeat;
}
</style>

<div class="logo"></div>

Reading an image file into bitmap from sdcard, why am I getting a NullPointerException?

Try this code:

Bitmap bitmap = null;
File f = new File(_path);
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
try {
    bitmap = BitmapFactory.decodeStream(new FileInputStream(f), null, options);
} catch (FileNotFoundException e) {
    e.printStackTrace();
}         
image.setImageBitmap(bitmap);

How To Inject AuthenticationManager using Java Configuration in a Custom Filter

In addition to what Angular University said above you may want to use @Import to aggregate @Configuration classes to the other class (AuthenticationController in my case) :

@Import(SecurityConfig.class)
@RestController
public class AuthenticationController {
@Autowired
private AuthenticationManager authenticationManager;
//some logic
}

Spring doc about Aggregating @Configuration classes with @Import: link

Can I use library that used android support with Androidx projects.

If your project is not AndroidX (mean Appcompat) and got this error, try to downgrade dependencies versions that triggers this error, in my case play-services-location ("implementation 'com.google.android.gms:play-services-location:17.0.0'") , I solved the problem by downgrading to com.google.android.gms:play-services-location:16.0.0'

Getting datarow values into a string?

I've done this a lot myself. If you just need a comma separated list for all of row values you can do this:

StringBuilder sb = new StringBuilder();
foreach (DataRow row in results.Tables[0].Rows)     
{
    sb.AppendLine(string.Join(",", row.ItemArray));
}

A StringBuilder is the preferred method as string concatenation is significantly slower for large amounts of data.

Overlapping elements in CSS

I think you could get away with using relative positioning and then set the top/left positioning of the second DIV until you have it in the position desired.

How to detect a textbox's content has changed

I'd like to ask why you are trying to detect when the content of the textbox changed in real time?

An alternative would be to set a timer (via setIntval?) and compare last saved value to the current one and then reset a timer. This would guarantee catching ANY change, whether caused by keys, mouse, some other input device you didn't consider, or even JavaScript changing the value (another possiblity nobody mentioned) from a different part of the app.

Django Rest Framework File Upload

From my experience, you don't need to do anything particular about file fields, you just tell it to make use of the file field:

from rest_framework import routers, serializers, viewsets

class Photo(django.db.models.Model):
    file = django.db.models.ImageField()

    def __str__(self):
        return self.file.name

class PhotoSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Photo
        fields = ('id', 'file')   # <-- HERE

class PhotoViewSet(viewsets.ModelViewSet):
    queryset = models.Photo.objects.all()
    serializer_class = PhotoSerializer

router = routers.DefaultRouter()
router.register(r'photos', PhotoViewSet)

api_urlpatterns = ([
    url('', include(router.urls)),
], 'api')
urlpatterns += [
    url(r'^api/', include(api_urlpatterns)),
]

and you're ready to upload files:

curl -sS http://example.com/api/photos/ -F 'file=@/path/to/file'

Add -F field=value for each extra field your model has. And don't forget to add authentication.

CURL Command Line URL Parameters

Felipsmartins is correct.

It is worth mentioning that it is because you cannot really use the -d/--data option if this is not a POST request. But this is still possible if you use the -G option.

Which means you can do this:

curl -X DELETE -G 'http://localhost:5000/locations' -d 'id=3'

Here it is a bit silly but when you are on the command line and you have a lot of parameters, it is a lot tidier.

I am saying this because cURL commands are usually quite long, so it is worth making it on more than one line escaping the line breaks.

curl -X DELETE -G \
'http://localhost:5000/locations' \
-d id=3 \
-d name=Mario \
-d surname=Bros

This is obviously a lot more comfortable if you use zsh. I mean when you need to re-edit the previous command because zsh lets you go line by line. (just saying)

Hope it helps.

How is the java memory pool divided?

The new keyword allocates memory on the Java heap. The heap is the main pool of memory, accessible to the whole of the application. If there is not enough memory available to allocate for that object, the JVM attempts to reclaim some memory from the heap with a garbage collection. If it still cannot obtain enough memory, an OutOfMemoryError is thrown, and the JVM exits.

The heap is split into several different sections, called generations. As objects survive more garbage collections, they are promoted into different generations. The older generations are not garbage collected as often. Because these objects have already proven to be longer lived, they are less likely to be garbage collected.

When objects are first constructed, they are allocated in the Eden Space. If they survive a garbage collection, they are promoted to Survivor Space, and should they live long enough there, they are allocated to the Tenured Generation. This generation is garbage collected much less frequently.

There is also a fourth generation, called the Permanent Generation, or PermGen. The objects that reside here are not eligible to be garbage collected, and usually contain an immutable state necessary for the JVM to run, such as class definitions and the String constant pool. Note that the PermGen space is planned to be removed from Java 8, and will be replaced with a new space called Metaspace, which will be held in native memory. reference:http://www.programcreek.com/2013/04/jvm-run-time-data-areas/

Diagram of Java memory for several threads Diagram of Java memory distribution

Stretch Image to Fit 100% of Div Height and Width

Or you can put in the CSS,

<style>
div#img {
  background-image: url(“file.png");
  color:yellow (this part doesn't matter;
  height:100%;
  width:100%;
}
</style>

How to get box-shadow on left & right sides only

For horizontal only, you can trick the box-shadow using overflow on its parent div:

<div class="parent">
  <div class="box-shadow">content</div>
</div>

.parent{
  overflow:hidden;
}
.box-shadow{
  box-shadow: box-shadow: 0 5px 5px 0 #000;
}

Reverse for '*' with arguments '()' and keyword arguments '{}' not found

You need single quotes around the view name

{% url 'viewname' %}

instead of

{% url viewname %}

jQuery UI Dialog individual CSS styling

According to the UI dialog documentation, the dialog plugin generates something like this:

<div class="ui-dialog ui-widget ui-widget-content ui-corner-all ui-draggable ui-resizable">
   <div class="ui-dialog-titlebar ui-widget-header ui-corner-all ui-helper-clearfix">
      <span id="ui-dialog-title-dialog" class="ui-dialog-title">Dialog title</span>
      <a class="ui-dialog-titlebar-close ui-corner-all" href="#"><span class="ui-icon ui-icon-closethick">close</span></a>
   </div>
   <div class="ui-dialog-content ui-widget-content" id="dialog_style1">
      <p>One content</p>
   </div>
</div>

That means what you can add to any class to exactly to first or second dialog using jQuery's closest() method. For example:

$('#dialog_style1').closest('.ui-dialog').addClass('dialog_style1');

$('#dialog_style2').closest('.ui-dialog').addClass('dialog_style2');

and then CSS it.

MongoDB what are the default user and password?

In addition to previously provided answers, one option is to follow the 'localhost exception' approach to create the first user if your db is already started with access control (--auth switch). In order to do that, you need to have localhost access to the server and then run:

mongo
use admin
db.createUser(
 {
     user: "user_name",
     pwd: "user_pass",
     roles: [
           { role: "userAdminAnyDatabase", db: "admin" },
           { role: "readWriteAnyDatabase", db: "admin" },
           { role: "dbAdminAnyDatabase", db: "admin" }
        ]
 })

As stated in MongoDB documentation:

The localhost exception allows you to enable access control and then create the first user in the system. With the localhost exception, after you enable access control, connect to the localhost interface and create the first user in the admin database. The first user must have privileges to create other users, such as a user with the userAdmin or userAdminAnyDatabase role. Connections using the localhost exception only have access to create the first user on the admin database.

Here is the link to that section of the docs.

How best to determine if an argument is not sent to the JavaScript function

In ES6 (ES2015) you can use Default parameters

_x000D_
_x000D_
function Test(arg1 = 'Hello', arg2 = 'World!'){_x000D_
  alert(arg1 + ' ' +arg2);_x000D_
}_x000D_
_x000D_
Test('Hello', 'World!'); // Hello World!_x000D_
Test('Hello'); // Hello World!_x000D_
Test(); // Hello World!
_x000D_
_x000D_
_x000D_

How ViewBag in ASP.NET MVC works

ViewBag is a dynamic type that allow you to dynamically set or get values and allow you to add any number of additional fields without a strongly-typed class They allow you to pass data from controller to view. In controller......

public ActionResult Index()
{
    ViewBag.victor = "My name is Victor";
    return View();
}

In view

@foreach(string a in ViewBag.victor)
{
     .........
}

What I have learnt is that both should have the save dynamic name property ie ViewBag.victor

svn : how to create a branch from certain revision of trunk

append the revision using an "@" character:

svn copy http://src@REV http://dev

Or, use the -r [--revision] command line argument.

Why I get 411 Length required error?

I had the same error when I imported web requests from fiddler captured sessions to Visual Studio webtests. Some POST requests did not have a StringHttpBody tag. I added an empty one to them and the error was gone. Add this after the Headers tag:

    <StringHttpBody ContentType="" InsertByteOrderMark="False">
  </StringHttpBody>

How to Apply global font to whole HTML document

You should be able to utilize the asterisk and !important elements within CSS.

html *
{
   font-size: 1em !important;
   color: #000 !important;
   font-family: Arial !important;
}

The asterisk matches everything (you could probably get away without the html too).

The !important ensures that nothing can override what you've set in this style (unless it is also important). (this is to help with your requirement that it should "ignore inner formatting of text" - which I took to mean that other styles could not overwrite these)

The rest of the style within the braces is just like any other styling and you can do whatever you'd like to in there. I chose to change the font size, color and family as an example.

Get parent of current directory from Python script

from os.path import dirname
from os.path import abspath

def get_file_parent_dir_path():
    """return the path of the parent directory of current file's directory """
    current_dir_path = dirname(abspath(__file__))
    path_sep = os.path.sep
    components = current_dir_path.split(path_sep)
    return path_sep.join(components[:-1])

"document.getElementByClass is not a function"

    enter code here
var stopMusicExt = document.getElementByClass("stopButton").value;
    stopButton.onclick = function() {
        var ta = document.getElementByClass("stopButton");
        document['player'].stopMusicExt(ta.value);
        ta.value = "";
    };


// .value will hold all data from class stopButton

Java: get greatest common divisor

Those GCD functions provided by Commons-Math and Guava have some differences.

  • Commons-Math throws an ArithematicException.class only for Integer.MIN_VALUE or Long.MIN_VALUE.
    • Otherwise, handles the value as an absolute value.
  • Guava throws an IllegalArgumentException.class for any negative values.

delete all record from table in mysql

truncate tableName

That is what you are looking for.

Truncate will delete all records in the table, emptying it.

In Node.js, how do I "include" functions from my other files?

create two files e.g standard_funcs.js and main.js

1.) standard_funcs.js

// Declaration --------------------------------------

 module.exports =
   {
     add,
     subtract
     // ...
   }


// Implementation ----------------------------------

 function add(x, y)
 {
   return x + y;
 }

 function subtract(x, y)
 {
   return x - y;
 }
    

// ...

2.) main.js

// include ---------------------------------------

const sf= require("./standard_funcs.js")

// use -------------------------------------------

var x = sf.add(4,2);
console.log(x);

var y = sf.subtract(4,2);
console.log(y);

    

output

6
2

HashMaps and Null values?

It seems that you are trying to call a method with a Map parameter. So, to call with an empty person name the right approach should be

HashMap<String, String> options = new HashMap<String, String>();
options.put("name", null);  
Person person = sample.searchPerson(options);

Or you can do it like this

HashMap<String, String> options = new HashMap<String, String>();
Person person = sample.searchPerson(options);

Using

Person person = sample.searchPerson(null);

Could get you a null pointer exception. It all depends on the implementation of searchPerson() method.

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

While using Spring Boot 2.2 I run into a similiar error message and while googling my error message

No converter for [class java.util.ArrayList] with preset Content-Type 'null'

this question here is on top, but all answers here did not work for me, so I think it's a good idea to add the answer I found myself:

I had to add the following dependencies to the pom.xml:

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-oxm</artifactId>
</dependency>

<dependency>
  <groupId>com.thoughtworks.xstream</groupId>
  <artifactId>xstream</artifactId>
  <version>1.4.11.1</version>
</dependency>

After this I need to add the following to the WebApplication class:

@SpringBootApplication
public class WebApplication
 {
  // ...

  @Bean
  public HttpMessageConverter<Object> createXmlHttpMessageConverter()
   {
    final MarshallingHttpMessageConverter xmlConverter = new MarshallingHttpMessageConverter();
    final XStreamMarshaller xstreamMarshaller = new XStreamMarshaller();
    xstreamMarshaller.setAutodetectAnnotations(true);
    xmlConverter.setMarshaller(xstreamMarshaller);
    xmlConverter.setUnmarshaller(xstreamMarshaller);
    return xmlConverter;
   }

}

Last but not least within my @Controller I used:

@GetMapping(produces = {MediaType.APPLICATION_XML_VALUE, MediaType. APPLICATION_JSON_VALUE})
@ResponseBody
public List<MeterTypeEntity> listXmlJson(final Model model)
 {
  return this.service.list();
 }

So now I got JSON and XML return values depending on the requests Accept header.

To make the XML output more readable (remove the complete package name from tag names) you could also add @XStreamAlias the following to your entity class:

@Table("ExampleTypes")
@XStreamAlias("ExampleType")
public class ExampleTypeEntity
 {
  // ...
 }

Hopefully this will help others with the same problem.

Failed to load c++ bson extension

I fixed this problem on CentOS by

  • sudo yum groupinstall "Development Tools"
  • sudo npm install -g node-gyp
  • rm -r node_modules
  • npm cache clean
  • npm install

How to plot a function curve in R

Here is a lattice version:

library(lattice)
eq<-function(x) {x*x}
X<-1:1000
xyplot(eq(X)~X,type="l")

Lattice output

Violation of PRIMARY KEY constraint. Cannot insert duplicate key in object

I was getting the same error on a restored database when I tried to insert a new record using the EntityFramework. It turned out that the Indentity/Seed was screwing things up.

Using a reseed command fixed it.

DBCC CHECKIDENT ('[Prices]', RESEED, 4747030);GO

X-UA-Compatible is set to IE=edge, but it still doesn't stop Compatibility Mode

Even if you have unchecked the "Display intranet sites in Compatibility View" option, and have the X-UA-Compatible in your response headers, there is another reason why your browser might default to "Compatibility View" anyways - your Group Policy. Look at your console for the following message:

HTML1203: xxx.xxx has been configured to run in Compatibility View through Group Policy.

Where xxx.xxx is the domain for your site (i.e. test.com). If you see this then the group policy for your domain is set so that any site ending in test.com will automatically render in Compatibility mode regardless of doctype, headers, etc.

For more information, please see the following link (explains the html codes): http://msdn.microsoft.com/en-us/library/ie/hh180764(v=vs.85).aspx

Windows Application has stopped working :: Event Name CLR20r3

Download and install SAP Crystal Reports Runtime engine for .net (32 bit or 64 bit) depending on your os version. Should work there after

Clean out Eclipse workspace metadata

In my case eclipse is not showing parent class function on $this, so I perform below mention points and it starts works:-

I go to my /var/www/ folder and check for .metadata folder (Here check the .log file and it shows) Resource is out of sync with the file system: 1. Go to Eclipse --> Project --> Clean 2. Windows -- preferences --> General --> Workspace --> And set it to "Refresh Automatically"

After that boom - things gets start working :)

If you want to load variables from other files too then ado this :- Eclipse-->Windows-->Preferences-->Php-->Editor-->Content Assist --> and check "show variable from other files"

Then it will show element , variables and other functions also.

Unit Testing C Code

API Sanity Checker — test framework for C/C++ libraries:

An automatic generator of basic unit tests for a shared C/C++ library. It is able to generate reasonable (in most, but unfortunately not all, cases) input data for parameters and compose simple ("sanity" or "shallow"-quality) test cases for every function in the API through the analysis of declarations in header files.

The quality of generated tests allows to check absence of critical errors in simple use cases. The tool is able to build and execute generated tests and detect crashes (segfaults), aborts, all kinds of emitted signals, non-zero program return code and program hanging.

Examples:

How best to read a File into List<string>

You can simple read this way .

List<string> lines = System.IO.File.ReadLines(completePath).ToList();

How to write a multiline Jinja statement

According to the documentation: https://jinja.palletsprojects.com/en/2.10.x/templates/#line-statements you may use multi-line statements as long as the code has parens/brackets around it. Example:

{% if ( (foo == 'foo' or bar == 'bar') and 
        (fooo == 'fooo' or baar == 'baar') ) %}
    <li>some text</li>
{% endif %}

Edit: Using line_statement_prefix = '#'* the code would look like this:

# if ( (foo == 'foo' or bar == 'bar') and 
       (fooo == 'fooo' or baar == 'baar') )
    <li>some text</li>
# endif

*Here's an example of how you'd specify the line_statement_prefix in the Environment:

from jinja2 import Environment, PackageLoader, select_autoescape
env = Environment(
    loader=PackageLoader('yourapplication', 'templates'),
    autoescape=select_autoescape(['html', 'xml']),
    line_statement_prefix='#'
)

Or using Flask:

from flask import Flask
app = Flask(__name__, instance_relative_config=True, static_folder='static')
app.jinja_env.filters['zip'] = zip
app.jinja_env.line_statement_prefix = '#'

PostgreSQL: How to make "case-insensitive" query

You can use ILIKE. i.e.

SELECT id FROM groups where name ILIKE 'administrator'

Viewing contents of a .jar file

If I understand correctly, you want to see not only classes but also methods, properties and so on. The only tool I know that can do it is Eclipse - if you add a jar to project classpath, you would be able to browse its classes with methods and properties using usual package explorer.

Anyway, this is a good idea for a good standalone Java tool

Split files using tar, gz, zip, or bzip2

Tested code, initially creates a single archive file, then splits it:

 gzip -c file.orig > file.gz
 CHUNKSIZE=1073741824
 PARTCNT=$[$(stat -c%s file.gz) / $CHUNKSIZE]

 # the remainder is taken care of, for example for
 # 1 GiB + 1 bytes PARTCNT is 1 and seq 0 $PARTCNT covers
 # all of file
 for n in `seq 0 $PARTCNT`
 do
       dd if=file.gz of=part.$n bs=$CHUNKSIZE skip=$n count=1
 done

This variant omits creating a single archive file and goes straight to creating parts:

gzip -c file.orig |
    ( CHUNKSIZE=1073741824;
        i=0;
        while true; do
            i=$[i+1];
            head -c "$CHUNKSIZE" > "part.$i";
            [ "$CHUNKSIZE" -eq $(stat -c%s "part.$i") ] || break;
        done; )

In this variant, if the archive's file size is divisible by $CHUNKSIZE, then the last partial file will have file size 0 bytes.

How can I get the key value in a JSON object?

Try out this

var str ="{ "name" : "user"}";
var jsonData = JSON.parse(str);     
console.log(jsonData.name)

//Array Object

str ="[{ "name" : "user"},{ "name" : "user2"}]";
jsonData = JSON.parse(str);     
console.log(jsonData[0].name)

Markdown and including multiple files

I'm actually surprised that no one in this page has offered any HTML solutions. As far I have understood MarkDown files can include wide portion (if not all) of HTML tags. So follow these steps:

  1. From here: put your MarkDown files in <span style="display:block"> ... </span> tags to be sure they will be rendered as markdown. You have a whole lot of other style properties you can add. The one I like is the text-align:justify.

  2. From here: Include the files in your main file using the <iframe src="/path/to/file.md" seamless></iframe>

P.S.1. this solution does not work on all MarkDown engines / renders. For example Typora did render the files correctly but Visual Studio Code didn't. It would be great if others could share their experience with other platforms. Specially I would like to hear about GitHub and GitLab ...

P.S.2. On further investigation there seems to be major incompatibility issues leading to this not being properly rendered on many platforms, including Typora, GitHub and Visual Studio code. Please do not use this till I resolve them. I will not delete the answer just for the sake of discussion and if maybe you can share your opinions.

P.S.3. To further investigate this issue I have asked this questions here on StackOverflow and here on Reddit.

P.S.4. After some through study, I came to the conclusion that for the moment AsciiDoc is a better option for documentation. It comes with built-in include functionality, it is rendered by GitHub, and major code editors like Atom and vscode have extensions for live preview. One can use Pandoc or other tools to automatically convert existing MarkDown Code to AsciiDoc with minor changes.

P.S.5. Another lightweight markup language with built-in include functionality is reStructuredText. It comes with .. include:: inclusion.txt syntax by standard. There is ReText editor with live preview as well.

How to fix JSP compiler warning: one JAR was scanned for TLDs yet contained no TLDs?

The warning comes up because Tomcat scans all Jars for TLDs (Tagging Library Definitions).

Step1: To see which JARs are throwing up this warning, insert he following line to tomcat/conf/logging.properties

org.apache.jasper.servlet.TldScanner.level = FINE

Now you should be able to see warnings with a detail of which JARs are causing the intial warning

Step2 Since skipping unneeded JARs during scanning can improve startup time and JSP compilation time, we will skip un-needed JARS in the catalina.properties file. You have two options here -

  1. List all the JARs under the tomcat.util.scan.StandardJarScanFilter.jarsToSkip. But this can get cumbersome if you have a lot jars or if the jars keep changing.
  2. Alternatively, Insert tomcat.util.scan.StandardJarScanFilter.jarsToSkip=* to skip all the jars

You should now not see the above warnings and if you have a considerably large application, it should save you significant time in deploying an application.

Note: Tested in Tomcat8

performSelector may cause a leak because its selector is unknown

Matt Galloway's answer on this thread explains the why:

Consider the following:

id anotherObject1 = [someObject performSelector:@selector(copy)];
id anotherObject2 = [someObject performSelector:@selector(giveMeAnotherNonRetainedObject)];

Now, how can ARC know that the first returns an object with a retain count of 1 but the second returns an object which is autoreleased?

It seems that it is generally safe to suppress the warning if you are ignoring the return value. I'm not sure what the best practice is if you really need to get a retained object from performSelector -- other than "don't do that".

MSOnline can't be imported on PowerShell (Connect-MsolService error)

After hours of searching and trying I found out that on a x64 server the MSOnline modules must be installed for x64, and some programs that need to run them are using the x86 PS version, so they will never find it.

[SOLUTION] What I did to solve the issue was:

Copy the folders called MSOnline and MSOnline Extended from the source

C:\Windows\System32\WindowsPowerShell\v1.0\Modules\

to the folder

C:\Windows\SysWOW64\WindowsPowerShell\v1.0\Modules\

And then in PS run the Import-Module MSOnline, and it will automatically get the module :D

Objective-C Static Class Level variables

Issue Description:

  1. You want your ClassA to have a ClassB class variable.
  2. You are using Objective-C as programming language.
  3. Objective-C does not support class variables as C++ does.

One Alternative:

Simulate a class variable behavior using Objective-C features

  1. Declare/Define an static variable within the classA.m so it will be only accessible for the classA methods (and everything you put inside classA.m).

  2. Overwrite the NSObject initialize class method to initialize just once the static variable with an instance of ClassB.

  3. You will be wondering, why should I overwrite the NSObject initialize method. Apple documentation about this method has the answer: "The runtime sends initialize to each class in a program exactly one time just before the class, or any class that inherits from it, is sent its first message from within the program. (Thus the method may never be invoked if the class is not used.)".

  4. Feel free to use the static variable within any ClassA class/instance method.

Code sample:

file: classA.m

static ClassB *classVariableName = nil;

@implementation ClassA

...
 
+(void) initialize
{
    if (! classVariableName)
        classVariableName = [[ClassB alloc] init];
}

+(void) classMethodName
{
    [classVariableName doSomething]; 
}

-(void) instanceMethodName
{
    [classVariableName doSomething]; 
}

...

@end

References:

  1. Class variables explained comparing Objective-C and C++ approaches

What is the keyguard in Android?

In a nutshell, it is your lockscreen.

PIN, pattern, face, password locks or the default lock (slide to unlock), but it is your lock screen.

Insert data through ajax into mysql database

The ajax is going to be a javascript snippet that passes information to a small php file that does what you want. So in your page, instead of all that php, you want a little javascript, preferable jquery:

function fun()
{
    $.get('\addEmail.php', {email : $(this).val()}, function(data) {
        //here you would write the "you ve been successfully subscribed" div
    });
}

also you input would have to be:

<input type="button" value="subscribe" class="submit" onclick="fun();" />

last the file addEmail.php should look something like:

mysql_connect("localhost","root","");
mysql_select_db("eciticket_db");

error_reporting(E_ALL && ~E_NOTICE);

$email=mysql_real_escape_string($_GET['email']);
$sql="INSERT INTO newsletter_email(email) VALUES ('$email')";
$result=mysql_query($sql);
if($result){
echo "You have been successfully subscribed.";
}
 if(!$sql)
die(mysql_error());

mysql_close();

Also sergey is right, you should use mysqli. That's not everything, but enough to get you started.

How to display a confirmation dialog when clicking an <a> link?

USING PHP, HTML AND JAVASCRIPT for prompting

Just if someone looking for using php, html and javascript in a single file, the answer below is working for me.. i attached with the used of bootstrap icon "trash" for the link.

<a class="btn btn-danger" href="<?php echo "delete.php?&var=$var"; ?>" onclick="return confirm('Are you sure want to delete this?');"><span class="glyphicon glyphicon-trash"></span></a>

the reason i used php code in the middle is because i cant use it from the beginning..

the code below doesnt work for me:-

echo "<a class='btn btn-danger' href='delete.php?&var=$var' onclick='return confirm('Are you sure want to delete this?');'><span class='glyphicon glyphicon-trash'></span></a>";

and i modified it as in the 1st code then i run as just what i need.. I hope that can i can help someone inneed of my case.

How can I get the username of the logged-in user in Django?

request.user.get_username() will return a string of the users email.

request.user.username will return a method.

How to get first and last element in an array in java?

If you have a double array named numbers, you can use:

firstNum = numbers[0];
lastNum = numbers[numbers.length-1];

or with ArrayList

firstNum = numbers.get(0);
lastNum = numbers.get(numbers.size() - 1); 

How to plot a very simple bar chart (Python, Matplotlib) using input *.txt file?

You're talking about histograms, but this doesn't quite make sense. Histograms and bar charts are different things. An histogram would be a bar chart representing the sum of values per year, for example. Here, you just seem to be after bars.

Here is a complete example from your data that shows a bar of for each required value at each date:

import pylab as pl
import datetime

data = """0 14-11-2003
1 15-03-1999
12 04-12-2012
33 09-05-2007
44 16-08-1998
55 25-07-2001
76 31-12-2011
87 25-06-1993
118 16-02-1995
119 10-02-1981
145 03-05-2014"""

values = []
dates = []

for line in data.split("\n"):
    x, y = line.split()
    values.append(int(x))
    dates.append(datetime.datetime.strptime(y, "%d-%m-%Y").date())

fig = pl.figure()
ax = pl.subplot(111)
ax.bar(dates, values, width=100)
ax.xaxis_date()

You need to parse the date with strptime and set the x-axis to use dates (as described in this answer).

If you're not interested in having the x-axis show a linear time scale, but just want bars with labels, you can do this instead:

fig = pl.figure()
ax = pl.subplot(111)
ax.bar(range(len(dates)), values)

EDIT: Following comments, for all the ticks, and for them to be centred, pass the range to set_ticks (and move them by half the bar width):

fig = pl.figure()
ax = pl.subplot(111)
width=0.8
ax.bar(range(len(dates)), values, width=width)
ax.set_xticks(np.arange(len(dates)) + width/2)
ax.set_xticklabels(dates, rotation=90)

How to restart a rails server on Heroku?

Just type the following commands from console.

cd /your_project
heroku restart

npm install from Git in a specific version

I describe here a problem that I faced when run npm install - the package does not appear in node_modules.

The issue was that the name value in package.json of installed package was different than the name of imported package (key in package.json of my project).

So if your installed project name is some-package (name value in its package.json) then in package.json of your project write: "some-package": "owner/some-repo#tag".

error code 1292 incorrect date value mysql

I happened to be working in localhost , in windows 10, using WAMP, as it turns out, Wamp has a really accessible configuration interface to change the MySQL configuration. You just need to go to the Wamp panel, then to MySQL, then to settings and change the mode to sql-mode: none.(essentially disabling the strict mode) The following picture illustrates this.

enter image description here

How to add new activity to existing project in Android Studio?

I think natually do it is straightforward, whether Intellij IDEA or Android Studio, I always click new Java class menu, and then typing the class name, press Enter to create. after that, I manually typing "extends Activity" in the class file, and then import the class by shortcut key. finally, I also manually override the onCreate() method and invoke the setContentView() method.

Truncate (not round) decimal places in SQL Server

Try like this:

SELECT cast(round(123.456,2,1) as decimal(18,2)) 

Can Selenium WebDriver open browser windows silently in the background?

If you are using Selenium web driver with Python, you can use PyVirtualDisplay, a Python wrapper for Xvfb and Xephyr.

PyVirtualDisplay needs Xvfb as a dependency. On Ubuntu, first install Xvfb:

sudo apt-get install xvfb

Then install PyVirtualDisplay from PyPI:

pip install pyvirtualdisplay

Sample Selenium script in Python in a headless mode with PyVirtualDisplay:

    #!/usr/bin/env python

    from pyvirtualdisplay import Display
    from selenium import webdriver

    display = Display(visible=0, size=(800, 600))
    display.start()

    # Now Firefox will run in a virtual display.
    # You will not see the browser.
    browser = webdriver.Firefox()
    browser.get('http://www.google.com')
    print browser.title
    browser.quit()

    display.stop()

EDIT

The initial answer was posted in 2014 and now we are at the cusp of 2018. Like everything else, browsers have also advanced. Chrome has a completely headless version now which eliminates the need to use any third-party libraries to hide the UI window. Sample code is as follows:

    from selenium import webdriver
    from selenium.webdriver.chrome.options import Options

    CHROME_PATH = '/usr/bin/google-chrome'
    CHROMEDRIVER_PATH = '/usr/bin/chromedriver'
    WINDOW_SIZE = "1920,1080"

    chrome_options = Options()
    chrome_options.add_argument("--headless")
    chrome_options.add_argument("--window-size=%s" % WINDOW_SIZE)
    chrome_options.binary_location = CHROME_PATH

    driver = webdriver.Chrome(executable_path=CHROMEDRIVER_PATH,
                              chrome_options=chrome_options
                             )
    driver.get("https://www.google.com")
    driver.get_screenshot_as_file("capture.png")
    driver.close()

Converting int to bytes in Python 3

int (including Python2's long) can be converted to bytes using following function:

import codecs

def int2bytes(i):
    hex_value = '{0:x}'.format(i)
    # make length of hex_value a multiple of two
    hex_value = '0' * (len(hex_value) % 2) + hex_value
    return codecs.decode(hex_value, 'hex_codec')

The reverse conversion can be done by another one:

import codecs
import six  # should be installed via 'pip install six'

long = six.integer_types[-1]

def bytes2int(b):
    return long(codecs.encode(b, 'hex_codec'), 16)

Both functions work on both Python2 and Python3.

Strip first and last character from C string

The most efficient way:

//Note destroys the original string by removing it's last char
// Do not pass in a string literal.
char * getAllButFirstAndLast(char *input)
{
  int len = strlen(input); 
  if(len > 0)
    input++;//Go past the first char
  if(len > 1)
    input[len - 2] = '\0';//Replace the last char with a null termination
  return input;
}


//...
//Call it like so
char str[512];
strcpy(str, "hello world");
char *pMod = getAllButFirstAndLast(str);

The safest way:

void getAllButFirstAndLast(const char *input, char *output)
{
  int len = strlen(input);
  if(len > 0)
    strcpy(output, ++input);
  if(len > 1)
    output[len - 2] = '\0';
}


//...
//Call it like so
char mod[512];
getAllButFirstAndLast("hello world", mod);

The second way is less efficient but it is safer because you can pass in string literals into input. You could also use strdup for the second way if you didn't want to implement it yourself.

How can I clear the input text after clicking

If you need placeholder like behavior. you can use this.

$("selector").data("DefaultText", SetYourDefaultTextHere);
// You can also define the DefaultText as attribute and access that using attr() function

$("selector").focus(function(){
if($(this).val() == $(this).data("DefaultText"))
   $(this).val('');
});

SELECT INTO a table variable in T-SQL

The purpose of SELECT INTO is (per the docs, my emphasis)

To create a new table from values in another table

But you already have a target table! So what you want is

The INSERT statement adds one or more new rows to a table

You can specify the data values in the following ways:

...

By using a SELECT subquery to specify the data values for one or more rows, such as:

  INSERT INTO MyTable 
 (PriKey, Description)
        SELECT ForeignKey, Description
        FROM SomeView

And in this syntax, it's allowed for MyTable to be a table variable.

How to Update/Drop a Hive Partition?

You can either copy files into the folder where external partition is located or use

INSERT OVERWRITE TABLE tablename1 PARTITION (partcol1=val1, partcol2=val2...)...

statement.

SQL Server Pivot Table with multiple column aggregates

The least complicated, most straight-forward way of doing this is by simply wrapping your main query with the pivot in a common table expression, then grouping/aggregating.

WITH PivotCTE AS
(
    select * from  mytransactions
    pivot (sum (totalcount) for country in ([Australia], [Austria])) as pvt
)
SELECT
    numericmonth,
    chardate,
    SUM(totalamount) AS totalamount,
    SUM(ISNULL(Australia, 0)) AS Australia,
    SUM(ISNULL(Austria, 0)) Austria
FROM PivotCTE
GROUP BY numericmonth, chardate

The ISNULL is to stop a NULL value from nullifying the sum (because NULL + any value = NULL)

Pandas concat: ValueError: Shape of passed values is blah, indices imply blah2

Try sorting index after concatenating them

result=pd.concat([df1,df2]).sort_index()

OpenCV TypeError: Expected cv::UMat for argument 'src' - What is this?

Not your code is the problem this is perfectly fine:

gray = cv2.cvtColor(imgUMat, cv2.COLOR_RGB2GRAY)

The problem is that imgUMat is None so you probably made a mistake when loading your image:

imgUMat = cv2.imread("your_image.jpg")

I suspect you just entered the wrong image path.

How to set time to midnight for current day?

You can use the Date property of the DateTime object - eg

DateTime midnight = DateTime.Now.Date;

So your code example becomes

private DateTime _Begin = DateTime.Now.Date;
public DateTime Begin { get { return _Begin; } set { _Begin = value; } }

PS. going back to your original code setting the hours to 12 will give you time of noon for the current day, so instead you could have used 0...

var now = DateTime.Now;
new DateTime(now.Year, now.Month, now.Day, 0, 0, 0);

How to copy folders to docker image from Dockerfile?

FROM openjdk:8-jdk-alpine RUN apk update && apk add wget openssl lsof procps curl RUN apk update RUN mkdir -p /apps/agent RUN mkdir -p /apps/lib ADD ./app/agent /apps/agent ADD ./app/lib /apps/lib ADD ./app/* /apps/app/ RUN ls -lrt /apps/app/ CMD sh /apps/app/launch.sh

by using DockerFile, I'm copying agent and lib directories to /apps/agent,/apps/lib directories and bunch of files to target.

Wordpress 403/404 Errors: You don't have permission to access /wp-admin/themes.php on this server

Hopefully people will find this answer as there are many, many posts about this on the web. Many people suggested it was an .htaccess problem, and for me it was. However, I had been looking in the .htaccess in the root, not in the .htaccess in the wp-admin folder. Normally, I work on this site in particular through terminal services, so when it booted me and I couldn't log back in, I was trying to access it from my home computer (and it's IP).

Silly me forgot the IP restriction I had placed in the wp-admin .htaccess file.

AuthName "Protected"
AuthType Basic
<Limit GET POST>
order deny,allow
deny from all
allow from 11.11.11.11
</Limit> 

If you have something like this in your wp-admin .htaccess files, that would easily explain why all the sites you work on ceased to function at the same time. Internet providers occasionally rotate IPs so that nobody is running a server from home without paying for it.

Regular expression to remove HTML tags from a string

You should not attempt to parse HTML with regex. HTML is not a regular language, so any regex you come up with will likely fail on some esoteric edge case. Please refer to the seminal answer to this question for specifics. While mostly formatted as a joke, it makes a very good point.


The following examples are Java, but the regex will be similar -- if not identical -- for other languages.


String target = someString.replaceAll("<[^>]*>", "");

Assuming your non-html does not contain any < or > and that your input string is correctly structured.

If you know they're a specific tag -- for example you know the text contains only <td> tags, you could do something like this:

String target = someString.replaceAll("(?i)<td[^>]*>", "");

Edit: Omega brought up a good point in a comment on another post that this would result in multiple results all being squished together if there were multiple tags.

For example, if the input string were <td>Something</td><td>Another Thing</td>, then the above would result in SomethingAnother Thing.

In a situation where multiple tags are expected, we could do something like:

String target = someString.replaceAll("(?i)<td[^>]*>", " ").replaceAll("\\s+", " ").trim();

This replaces the HTML with a single space, then collapses whitespace, and then trims any on the ends.

Use cases for the 'setdefault' dict method

One drawback of defaultdict over dict (dict.setdefault) is that a defaultdict object creates a new item EVERYTIME non existing key is given (eg with ==, print). Also the defaultdict class is generally way less common then the dict class, its more difficult to serialize it IME.

P.S. IMO functions|methods not meant to mutate an object, should not mutate an object.

Format datetime in asp.net mvc 4

Ahhhh, now it is clear. You seem to have problems binding back the value. Not with displaying it on the view. Indeed, that's the fault of the default model binder. You could write and use a custom one that will take into consideration the [DisplayFormat] attribute on your model. I have illustrated such a custom model binder here: https://stackoverflow.com/a/7836093/29407


Apparently some problems still persist. Here's my full setup working perfectly fine on both ASP.NET MVC 3 & 4 RC.

Model:

public class MyViewModel
{
    [DisplayName("date of birth")]
    [DataType(DataType.Date)]
    [DisplayFormat(DataFormatString = "{0:dd/MM/yyyy}", ApplyFormatInEditMode = true)]
    public DateTime? Birth { get; set; }
}

Controller:

public class HomeController : Controller
{
    public ActionResult Index()
    {
        return View(new MyViewModel
        {
            Birth = DateTime.Now
        });
    }

    [HttpPost]
    public ActionResult Index(MyViewModel model)
    {
        return View(model);
    }
}

View:

@model MyViewModel

@using (Html.BeginForm())
{
    @Html.LabelFor(x => x.Birth)
    @Html.EditorFor(x => x.Birth)
    @Html.ValidationMessageFor(x => x.Birth)
    <button type="submit">OK</button>
}

Registration of the custom model binder in Application_Start:

ModelBinders.Binders.Add(typeof(DateTime?), new MyDateTimeModelBinder());

And the custom model binder itself:

public class MyDateTimeModelBinder : DefaultModelBinder
{
    public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        var displayFormat = bindingContext.ModelMetadata.DisplayFormatString;
        var value = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);

        if (!string.IsNullOrEmpty(displayFormat) && value != null)
        {
            DateTime date;
            displayFormat = displayFormat.Replace("{0:", string.Empty).Replace("}", string.Empty);
            // use the format specified in the DisplayFormat attribute to parse the date
            if (DateTime.TryParseExact(value.AttemptedValue, displayFormat, CultureInfo.InvariantCulture, DateTimeStyles.None, out date))
            {
                return date;
            }
            else
            {
                bindingContext.ModelState.AddModelError(
                    bindingContext.ModelName,
                    string.Format("{0} is an invalid date format", value.AttemptedValue)
                );
            }
        }

        return base.BindModel(controllerContext, bindingContext);
    }
}

Now, no matter what culture you have setup in your web.config (<globalization> element) or the current thread culture, the custom model binder will use the DisplayFormat attribute's date format when parsing nullable dates.

flutter run: No connected devices

If you have already installed and set-up your emulator, but facing the issue during running your app, You can try these steps to fix this issue.

Steps:

  1. Open Android Studio
  2. Tools -> AVD Manager
  3. Virtual Device -> Actions (Refer Image)
  4. Click On Stop
  5. Now Start Emulator

Note - If it's still not working, Try again the 4th step By Wiping your data.

Hope this works 4 you ;)

IntelliJ IDEA "The selected directory is not a valid home for JDK"

I had the same issue. But I figured it out by choosing this path:

First at all, you need to select the C:\ folder. Then, you select Program Files. After it, you select java, and finally the jdk you downloaded. In my case, I downloaded the JDK1.8.0_60 version.

To resume the path:

C:\Program Files\java\jdk1.8.0_60

After you are done with it, you can click on the button next. Then you select the create project from templates. This will create a java application with a main() method. After it, you click next to create the name of you project.

I hope this helps you.

How to compare two dates to find time difference in SQL Server 2005, date manipulation

You can use the DATEDIFF function to get the difference in minutes, seconds, days etc.

SELECT DATEDIFF(MINUTE,job_start,job_end)

MINUTE obviously returns the difference in minutes, you can also use DAY, HOUR, SECOND, YEAR (see the books online link for the full list).

If you want to get fancy you can show this differently for example 75 minutes could be displayed like this: 01:15:00:0

Here is the code to do that for both SQL Server 2005 and 2008

-- SQL Server 2005
SELECT CONVERT(VARCHAR(10),DATEADD(MINUTE,DATEDIFF(MINUTE,job_start,job_end),'2011-01-01 00:00:00.000'),114)

-- SQL Server 2008
SELECT CAST(DATEADD(MINUTE,DATEDIFF(MINUTE,job_start,job_end),'2011-01-01 00:00:00.000') AS TIME)

Build the full path filename in Python

Just use os.path.join to join your path with the filename and extension. Use sys.argv to access arguments passed to the script when executing it:

#!/usr/bin/env python3
# coding: utf-8

# import netCDF4 as nc
import numpy as np
import numpy.ma as ma
import csv as csv

import os.path
import sys

basedir = '/data/reu_data/soil_moisture/'
suffix = 'nc'


def read_fid(filename):
    fid = nc.MFDataset(filename,'r')
    fid.close()
    return fid

def read_var(file, varname):
    fid = nc.Dataset(file, 'r')
    out = fid.variables[varname][:]
    fid.close()
    return out


if __name__ == '__main__':
    if len(sys.argv) < 2:
        print('Please specify a year')

    else:
        filename = os.path.join(basedir, '.'.join((sys.argv[1], suffix)))
        time = read_var(ncf, 'time')
        lat = read_var(ncf, 'lat')
        lon = read_var(ncf, 'lon')
        soil = read_var(ncf, 'soilw')

Simply run the script like:

   # on windows-based systems
   python script.py year

   # on unix-based systems
   ./script.py year

Get file size, image width and height before upload

Here is a pure JavaScript example of picking an image file, displaying it, looping through the image properties, and then re-sizing the image from the canvas into an IMG tag and explicitly setting the re-sized image type to jpeg.

If you right click the top image, in the canvas tag, and choose Save File As, it will default to a PNG format. If you right click, and Save File as the lower image, it will default to a JPEG format. Any file over 400px in width is reduced to 400px in width, and a height proportional to the original file.

HTML

<form class='frmUpload'>
  <input name="picOneUpload" type="file" accept="image/*" onchange="picUpload(this.files[0])" >
</form>

<canvas id="cnvsForFormat" width="400" height="266" style="border:1px solid #c3c3c3"></canvas>
<div id='allImgProperties' style="display:inline"></div>

<div id='imgTwoForJPG'></div>

SCRIPT

<script>

window.picUpload = function(frmData) {
  console.log("picUpload ran: " + frmData);

var allObjtProperties = '';
for (objProprty in frmData) {
    console.log(objProprty + " : " + frmData[objProprty]);
    allObjtProperties = allObjtProperties + "<span>" + objProprty + ": " + frmData[objProprty] + ", </span>";
};

document.getElementById('allImgProperties').innerHTML = allObjtProperties;

var cnvs=document.getElementById("cnvsForFormat");
console.log("cnvs: " + cnvs);
var ctx=cnvs.getContext("2d");

var img = new Image;
img.src = URL.createObjectURL(frmData);

console.log('img: ' + img);

img.onload = function() {
  var picWidth = this.width;
  var picHeight = this.height;

  var wdthHghtRatio = picHeight/picWidth;
  console.log('wdthHghtRatio: ' + wdthHghtRatio);

  if (Number(picWidth) > 400) {
    var newHeight = Math.round(Number(400) * wdthHghtRatio);
  } else {
    return false;
  };

    document.getElementById('cnvsForFormat').height = newHeight;
    console.log('width: 400  h: ' + newHeight);
    //You must change the width and height settings in order to decrease the image size, but
    //it needs to be proportional to the original dimensions.
    console.log('This is BEFORE the DRAW IMAGE');
    ctx.drawImage(img,0,0, 400, newHeight);

    console.log('THIS IS AFTER THE DRAW IMAGE!');

    //Even if original image is jpeg, getting data out of the canvas will default to png if not specified
    var canvasToDtaUrl = cnvs.toDataURL("image/jpeg");
    //The type and size of the image in this new IMG tag will be JPEG, and possibly much smaller in size
    document.getElementById('imgTwoForJPG').innerHTML = "<img src='" + canvasToDtaUrl + "'>";
};
};

</script>

Here is a jsFiddle:

jsFiddle Pick, display, get properties, and Re-size an image file

In jsFiddle, right clicking the top image, which is a canvas, won't give you the same save options as right clicking the bottom image in an IMG tag.

"installation of package 'FILE_PATH' had non-zero exit status" in R

I had the same problem, but the answer from @little_chemist helped me sorting it out. When installing packages from a file in a unix OS (Ubuntu 18.04 for me), the file can not be zipped. You are using:

install.packages("/home/p/Research/14_bivpois-Rcode.zip", repos = NULL, type="source")

I noticed the solution was as simple as unzipping the package. Additionally, unzip all (installation related?) packages inside, as @little_chemist points out. Then use install.packages:

install.packages("/home/p/Research/14_bivpois-Rcode", repos = NULL, type="source")

Hope it helps!

grep from tar.gz without extracting [faster one]

If you have zgrep you can use

zgrep -a string file.tar.gz

<code> vs <pre> vs <samp> for inline and block code snippets

Something I completely missed: the non-wrapping behaviour of <pre> can be controlled with CSS. So this gives the exact result I was looking for:

_x000D_
_x000D_
code { _x000D_
    background: hsl(220, 80%, 90%); _x000D_
}_x000D_
_x000D_
pre {_x000D_
    white-space: pre-wrap;_x000D_
    background: hsl(30,80%,90%);_x000D_
}
_x000D_
Here's an example demonstrating the <code>&lt;code&gt;</code> tag._x000D_
_x000D_
<pre>_x000D_
Here's a very long pre-formatted formatted using the &lt;pre&gt; tag. Notice how it wraps?  It goes on and on and on and on and on and on and on and on and on and on..._x000D_
</pre>
_x000D_
_x000D_
_x000D_

http://jsfiddle.net/9mCN7/

C++11 rvalues and move semantics confusion (return statement)

As already mentioned in comments to the first answer, the return std::move(...); construct can make a difference in cases other than returning of local variables. Here's a runnable example that documents what happens when you return a member object with and without std::move():

#include <iostream>
#include <utility>

struct A {
  A() = default;
  A(const A&) { std::cout << "A copied\n"; }
  A(A&&) { std::cout << "A moved\n"; }
};

class B {
  A a;
 public:
  operator A() const & { std::cout << "B C-value: "; return a; }
  operator A() & { std::cout << "B L-value: "; return a; }
  operator A() && { std::cout << "B R-value: "; return a; }
};

class C {
  A a;
 public:
  operator A() const & { std::cout << "C C-value: "; return std::move(a); }
  operator A() & { std::cout << "C L-value: "; return std::move(a); }
  operator A() && { std::cout << "C R-value: "; return std::move(a); }
};

int main() {
  // Non-constant L-values
  B b;
  C c;
  A{b};    // B L-value: A copied
  A{c};    // C L-value: A moved

  // R-values
  A{B{}};  // B R-value: A copied
  A{C{}};  // C R-value: A moved

  // Constant L-values
  const B bc;
  const C cc;
  A{bc};   // B C-value: A copied
  A{cc};   // C C-value: A copied

  return 0;
}

Presumably, return std::move(some_member); only makes sense if you actually want to move the particular class member, e.g. in a case where class C represents short-lived adapter objects with the sole purpose of creating instances of struct A.

Notice how struct A always gets copied out of class B, even when the class B object is an R-value. This is because the compiler has no way to tell that class B's instance of struct A won't be used any more. In class C, the compiler does have this information from std::move(), which is why struct A gets moved, unless the instance of class C is constant.

Reading the selected value from asp:RadioButtonList using jQuery

A Radio Button List instead of a Radio button creates unique id tags name_0, name_1 etc. An easy way to test which is selected is by assigning a css class like

var deliveryService;
$('.deliveryservice input').each(function () {
    if (this.checked) {
        deliveryService = this.value
    }

IsNull function in DB2 SQL?

COALESCE function same ISNULL function Note. you must use COALESCE function with same data type of column that you check is null.

How to filter a dictionary according to an arbitrary condition function?

Nowadays, in Python 2.7 and up, you can use a dict comprehension:

{k: v for k, v in points.iteritems() if v[0] < 5 and v[1] < 5}

And in Python 3:

{k: v for k, v in points.items() if v[0] < 5 and v[1] < 5}

Check if an array is empty or exists

Using undescore or lodash:

_.isArray(image_array) && !_.isEmpty(image_array)

length and length() in Java

.length is a one-off property of Java. It's used to find the size of a single dimensional array.

.length() is a method. It's used to find the length of a String. It avoids duplicating the value.

javax.net.ssl.SSLException: Received fatal alert: protocol_version

This seems like a protocol version mismatch, this exception normally happens when there is a mismatch between SSL protocol version used by the client and the server. your clients should use a proctocol version supported by the server.

How to remove Firefox's dotted outline on BUTTONS as well as links?

You can try button::-moz-focus-inner {border: 0px solid transparent;} in your CSS.

Example of Named Pipes

You can actually write to a named pipe using its name, btw.

Open a command shell as Administrator to get around the default "Access is denied" error:

echo Hello > \\.\pipe\PipeName

Converting pixels to dp

Preferably put in a Util.java class

public static float dpFromPx(final Context context, final float px) {
    return px / context.getResources().getDisplayMetrics().density;
}

public static float pxFromDp(final Context context, final float dp) {
    return dp * context.getResources().getDisplayMetrics().density;
}

Java: Reading a file into an array

You should be able to use forward slashes in Java to refer to file locations.

The BufferedReader class is used for wrapping other file readers whos read method may not be very efficient. A more detailed description can be found in the Java APIs.

Toolkit's use of BufferedReader is probably what you need.

Why can't I have "public static const string S = "stuff"; in my Class?

From the C# language specification (PDF page 287 - or 300th page of the PDF):

Even though constants are considered static members, a constant declaration neither requires nor allows a static modifier.

Get local IP address in Node.js

The correct one-liner for both Underscore.js and Lodash is:

var ip = require('underscore')
    .chain(require('os').networkInterfaces())
    .values()
    .flatten()
    .find({family: 'IPv4', internal: false})
    .value()
    .address;

SQLite - getting number of rows in a database

If you want to use the MAX(id) instead of the count, after reading the comments from Pax then the following SQL will give you what you want

SELECT COALESCE(MAX(id)+1, 0) FROM words

How does the ARM architecture differ from x86?

The ARM architecture was originally designed for Acorn personal computers (See Acorn Archimedes, circa 1987, and RiscPC), which were just as much keyboard-based personal computers as were x86 based IBM PC models. Only later ARM implementations were primarily targeted at the mobile and embedded market segment.

Originally, simple RISC CPUs of roughly equivalent performance could be designed by much smaller engineering teams (see Berkeley RISC) than those working on the x86 development at Intel.

But, nowadays, the fastest ARM chips have very complex multi-issue out-of-order instruction dispatch units designed by large engineering teams, and x86 cores may have something like a RISC core fed by an instruction translation unit.

So, any current differences between the two architectures are more related to the specific market needs of the product niches that the development teams are targeting. (Random opinion: ARM probably makes more in license fees from embedded applications that tend to be far more power and cost constrained. And Intel needs to maintain a performance edge in PCs and servers for their profit margins. Thus you see differing implementation optimizations.)

Strange out of memory issue while loading an image to a Bitmap object

To fix the OutOfMemory error, you should do something like this:

BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 8;
Bitmap preview_bitmap = BitmapFactory.decodeStream(is, null, options);

This inSampleSize option reduces memory consumption.

Here's a complete method. First it reads image size without decoding the content itself. Then it finds the best inSampleSize value, it should be a power of 2, and finally the image is decoded.

// Decodes image and scales it to reduce memory consumption
private Bitmap decodeFile(File f) {
    try {
        // Decode image size
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(new FileInputStream(f), null, o);

        // The new size we want to scale to
        final int REQUIRED_SIZE=70;

        // Find the correct scale value. It should be the power of 2.
        int scale = 1;
        while(o.outWidth / scale / 2 >= REQUIRED_SIZE && 
              o.outHeight / scale / 2 >= REQUIRED_SIZE) {
            scale *= 2;
        }

        // Decode with inSampleSize
        BitmapFactory.Options o2 = new BitmapFactory.Options();
        o2.inSampleSize = scale;
        return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
    } catch (FileNotFoundException e) {}
    return null;
}

How should I make my VBA code compatible with 64-bit Windows?

i found this code (note that some Long are changed to LongPtr):

Declare PtrSafe Function ShellExecute Lib "shell32.dll" _
Alias "ShellExecuteA" (ByVal hwnd As LongPtr, ByVal lpOperation As String, _
ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As _
String, ByVal nShowCmd As Long) As LongPtr

source: http://www.cadsharp.com/docs/Win32API_PtrSafe.txt

SyntaxError: import declarations may only appear at top level of a module

I got this on Firefox (FF58). I fixed this with:

  1. It is still experimental on Firefox (from v54): You have to set to true the variable dom.moduleScripts.enabled in about:config

Source: Import page on mozilla (See Browser compatibility)

  1. Add type="module" to your script tag where you import the js file

<script type="module" src="appthatimports.js"></script>

  1. Import files have to be prefixed (./, /, ../ or http:// before)

import * from "./mylib.js"

For more examples, this blog post is good.

differences in application/json and application/x-www-form-urlencoded

webRequest.ContentType = "application/x-www-form-urlencoded";

  1. Where does application/x-www-form-urlencoded's name come from?

    If you send HTTP GET request, you can use query parameters as follows:

    http://example.com/path/to/page?name=ferret&color=purple

    The content of the fields is encoded as a query string. The application/x-www-form- urlencoded's name come from the previous url query parameter but the query parameters is in where the body of request instead of url.

    The whole form data is sent as a long query string.The query string contains name- value pairs separated by & character

    e.g. field1=value1&field2=value2

  2. It can be simple request called simple - don't trigger a preflight check

    Simple request must have some properties. You can look here for more info. One of them is that there are only three values allowed for Content-Type header for simple requests

    • application/x-www-form-urlencoded
    • multipart/form-data
    • text/plain

3.For mostly flat param trees, application/x-www-form-urlencoded is tried and tested.

request.ContentType = "application/json; charset=utf-8";

  1. The data will be json format.

axios and superagent, two of the more popular npm HTTP libraries, work with JSON bodies by default.

{
  "id": 1,
  "name": "Foo",
  "price": 123,
  "tags": [
    "Bar",
    "Eek"
  ],
  "stock": {
    "warehouse": 300,
    "retail": 20
  }
}
  1. "application/json" Content-Type is one of the Preflighted requests.

Now, if the request isn't simple request, the browser automatically sends a HTTP request before the original one by OPTIONS method to check whether it is safe to send the original request. If itis ok, Then send actual request. You can look here for more info.

  1. application/json is beginner-friendly. URL encoded arrays can be a nightmare!

How to install all required PHP extensions for Laravel?

Laravel Server Requirements mention that BCMath, Ctype, JSON, Mbstring, OpenSSL, PDO, Tokenizer, and XML extensions are required. Most of the extensions are installed and enabled by default.

You can run the following command in Ubuntu to make sure the extensions are installed.

sudo apt install openssl php-common php-curl php-json php-mbstring php-mysql php-xml php-zip

PHP version specific installation (if PHP 7.4 installed)

sudo apt install php7.4-common php7.4-bcmath openssl php7.4-json php7.4-mbstring

You may need other PHP extensions for your composer packages. Find from links below.

PHP extensions for Ubuntu 20.04 LTS (Focal Fossa)

PHP extensions for Ubuntu 18.04 LTS (Bionic)

PHP extensions for Ubuntu 16.04 LTS (Xenial)

Select Top and Last rows in a table (SQL server)

You must sort your data according your needs (es. in reverse order) and use select top query

Function is not defined - uncaught referenceerror

The problem is that codeAddress() doesn't have enough scope to be callable from the button. You must declare it outside the callback to ready():

function codeAddress() {
    var address = document.getElementById("formatedAddress").value;
    geocoder.geocode( { 'address': address}, function(results, status) {
        if (status == google.maps.GeocoderStatus.OK) {
            map.setCenter(results[0].geometry.location);
        }
    });
}


$(document).ready(function(){
    // Do stuff here, including _calling_ codeAddress(), but not _defining_ it!
});

Git conflict markers

The line (or lines) between the lines beginning <<<<<<< and ====== here:

<<<<<<< HEAD:file.txt
Hello world
=======

... is what you already had locally - you can tell because HEAD points to your current branch or commit. The line (or lines) between the lines beginning ======= and >>>>>>>:

=======
Goodbye
>>>>>>> 77976da35a11db4580b80ae27e8d65caf5208086:file.txt

... is what was introduced by the other (pulled) commit, in this case 77976da35a11. That is the object name (or "hash", "SHA1sum", etc.) of the commit that was merged into HEAD. All objects in git, whether they're commits (version), blobs (files), trees (directories) or tags have such an object name, which identifies them uniquely based on their content.

insert vertical divider line between two nested divs, not full height

Use a div for your divider. It will always be centered vertically regardless to whether left and right divs are equal in height. You can reuse it anywhere on your site.

.divider{
    position:absolute;
    left:50%;
    top:10%;
    bottom:10%;
    border-left:1px solid white;
}

Check working example at http://jsfiddle.net/gtKBs/

Apply style ONLY on IE

As well as a conditional comment could also use CSS Browser Selector http://rafael.adm.br/css_browser_selector/ as this will allow you to target specific browsers. You can then set your CSS as

.ie .actual-form table {
    width: 100%
    }

This will also allow you to target specific browsers within your main stylesheet without the need for conditional comments.

How to use Select2 with JSON via Ajax request?

for select2 v4.0.0 slightly different

$(".itemSearch").select2({
    tags: true,
    multiple: true,
    tokenSeparators: [',', ' '],
    minimumInputLength: 2,
    minimumResultsForSearch: 10,
    ajax: {
        url: URL,
        dataType: "json",
        type: "GET",
        data: function (params) {

            var queryParameters = {
                term: params.term
            }
            return queryParameters;
        },
        processResults: function (data) {
            return {
                results: $.map(data, function (item) {
                    return {
                        text: item.tag_value,
                        id: item.tag_id
                    }
                })
            };
        }
    }
});

Collections sort(List<T>,Comparator<? super T>) method example

Building upon your existing Student class, this is how I usually do it, especially if I need more than one comparator.

public class Student implements Comparable<Student> {

    String name;
    int age;

    public Student(String name, int age) {
       this.name = name;
       this.age = age;
    }

    @Override
    public String toString() {
        return name + ":" + age;
    }

    @Override
    public int compareTo(Student o) {
        return Comparators.NAME.compare(this, o);
    }


    public static class Comparators {

        public static Comparator<Student> NAME = new Comparator<Student>() {
            @Override
            public int compare(Student o1, Student o2) {
                return o1.name.compareTo(o2.name);
            }
        };
        public static Comparator<Student> AGE = new Comparator<Student>() {
            @Override
            public int compare(Student o1, Student o2) {
                return o1.age - o2.age;
            }
        };
        public static Comparator<Student> NAMEANDAGE = new Comparator<Student>() {
            @Override
            public int compare(Student o1, Student o2) {
                int i = o1.name.compareTo(o2.name);
                if (i == 0) {
                    i = o1.age - o2.age;
                }
                return i;
            }
        };
    }
}

Usage:

List<Student> studentList = new LinkedList<>();
Collections.sort(studentList, Student.Comparators.AGE);

EDIT

Since the release of Java 8 the inner class Comparators may be greatly simplified using lambdas. Java 8 also introduces a new method for the Comparator object thenComparing, which removes the need for doing manual checking of each comparator when nesting them. Below is the Java 8 implementation of the Student.Comparators class with these changes taken into account.

public static class Comparators {
    public static final Comparator<Student> NAME = (Student o1, Student o2) -> o1.name.compareTo(o2.name);
    public static final Comparator<Student> AGE = (Student o1, Student o2) -> Integer.compare(o1.age, o2.age);
    public static final Comparator<Student> NAMEANDAGE = (Student o1, Student o2) -> NAME.thenComparing(AGE).compare(o1, o2);
}

Do I need <class> elements in persistence.xml?

It's not a solution but a hint for those using Spring:

I tried to use org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean with setting persistenceXmlLocation but with this I had to provide the <class> elements (even if the persistenceXmlLocation just pointed to META-INF/persistence.xml).

When not using persistenceXmlLocation I could omit these <class> elements.

Does IE9 support console.log, and is it a real function?

In Internet Explorer 9 (and 8), the console object is only exposed when the developer tools are opened for a particular tab. If you hide the developer tools window for that tab, the console object remains exposed for each page you navigate to. If you open a new tab, you must also open the developer tools for that tab in order for the console object to be exposed.

The console object is not part of any standard and is an extension to the Document Object Model. Like other DOM objects, it is considered a host object and is not required to inherit from Object, nor its methods from Function, like native ECMAScript functions and objects do. This is the reason apply and call are undefined on those methods. In IE 9, most DOM objects were improved to inherit from native ECMAScript types. As the developer tools are considered an extension to IE (albeit, a built-in extension), they clearly didn't receive the same improvements as the rest of the DOM.

For what it's worth, you can still use some Function.prototype methods on console methods with a little bind() magic:

var log = Function.prototype.bind.call(console.log, console);
log.apply(console, ["this", "is", "a", "test"]);
//-> "thisisatest"