Can Rails Routing Helpers (i.e. mymodel_path(model)) be Used in Models?

In Rails 3, 4, and 5 you can use:

Rails.application.routes.url_helpers

e.g.

Rails.application.routes.url_helpers.posts_path
Rails.application.routes.url_helpers.posts_url(:host => "example.com")

What is the difference between window, screen, and document in Javascript?

Briefly, with more detail below,

window is the execution context and global object for that context's JavaScript
document contains the DOM, initialized by parsing HTML
screen describes the physical display's full screen

See W3C and Mozilla references for details about these objects. The most basic relationship among the three is that each browser tab has its own window, and a window has window.document and window.screen properties. The browser tab's window is the global context, so document and screen refer to window.document and window.screen. More details about the three objects are below, following Flanagan's JavaScript: Definitive Guide.

`window`

Each browser tab has its own top-level window object. Each <iframe> (and deprecated <frame>) element has its own window object too, nested within a parent window. Each of these windows gets its own separate global object. window.window always refers to window, but window.parent and window.top might refer to enclosing windows, giving access to other execution contexts. In addition to document and screen described below, window properties include

setTimeout() and setInterval() binding event handlers to a timer
location giving the current URL
history with methods back() and forward() giving the tab's mutable history
navigator describing the browser software

`document`

Each window object has a document object to be rendered. These objects get confused in part because HTML elements are added to the global object when assigned a unique id. E.g., in the HTML snippet

<body>
  <p id="holyCow"> This is the first paragraph.</p>
</body>

the paragraph element can be referenced by any of the following:

window.holyCow or window["holyCow"]
document.getElementById("holyCow")
document.querySelector("#holyCow")
document.body.firstChild
document.body.children[0]

`screen`

The window object also has a screen object with properties describing the physical display:

screen properties width and height are the full screen
screen properties availWidth and availHeight omit the toolbar

The portion of a screen displaying the rendered document is the viewport in JavaScript, which is potentially confusing because we call an application's portion of the screen a window when talking about interactions with the operating system. The getBoundingClientRect() method of any document element will return an object with top, left, bottom, and right properties describing the location of the element in the viewport.

C++ getters/setters coding style

Collected ideas from multiple C++ sources and put it into a nice, still quite simple example for getters/setters in C++:

class Canvas { public:
    void resize() {
        cout << "resize to " << width << " " << height << endl;
    }

    Canvas(int w, int h) : width(*this), height(*this) {
        cout << "new canvas " << w << " " << h << endl;
        width.value = w;
        height.value = h;
    }

    class Width { public:
        Canvas& canvas;
        int value;
        Width(Canvas& canvas): canvas(canvas) {}
        int & operator = (const int &i) {
            value = i;
            canvas.resize();
            return value;
        }
        operator int () const {
            return value;
        }
    } width;

    class Height { public:
        Canvas& canvas;
        int value;
        Height(Canvas& canvas): canvas(canvas) {}
        int & operator = (const int &i) {
            value = i;
            canvas.resize();
            return value;
        }
        operator int () const {
            return value;
        }
    } height;
};

int main() {
    Canvas canvas(256, 256);
    canvas.width = 128;
    canvas.height = 64;
}

Output:

new canvas 256 256
resize to 128 256
resize to 128 64

You can test it online here: http://codepad.org/zosxqjTX

PS: FO Yvette <3

Can't connect to docker from docker-compose

Try restarting your docker environment using:

systemctl restart docker

Deleting a pointer in C++

I believe you're not fully understanding how pointers work.
When you have a pointer pointing to some memory there are three different things you must understand:
- there is "what is pointed" by the pointer (the memory)
- this memory address
- not all pointers need to have their memory deleted: you only need to delete memory that was dynamically allocated (used new operator).

Imagine:

int *ptr = new int; 
// ptr has the address of the memory.
// at this point, the actual memory doesn't have anything.
*ptr = 8;
// you're assigning the integer 8 into that memory.
delete ptr;
// you are only deleting the memory.
// at this point the pointer still has the same memory address (as you could
//   notice from your 2nd test) but what inside that memory is gone!

When you did

ptr = NULL;
// you didn't delete the memory
// you're only saying that this pointer is now pointing to "nowhere".
// the memory that was pointed by this pointer is now lost.

C++ allows that you try to delete a pointer that points to null but it doesn't actually do anything, just doesn't give any error.

What is your most productive shortcut with Vim?

Inserting text to some bit in code:

ctrl + v, (selecting text on multiple lines), I, (type something I want), ESC

Recording a macro to edit text and running it N times:

q, a (or some other letter), (do the things I want to record), q, ESC,
(type N, as in the number of times I want to run the macro), @, a

How to change app default theme to a different app theme?

Actually you should define your styles in res/values/styles.xml. I guess now you've got the following configuration:

<style name="AppBaseTheme" parent="android:Theme.Holo.Light"/>
<style name="AppTheme" parent="AppBaseTheme"/>

so if you want to use Theme.Black then change AppBaseTheme parent to android:Theme.Black or you could change app style directly in manifest file like this - android:theme="@android:style/Theme.Black". You must be lacking android namespace before style tag.

You can read more about styles and themes here.

Regular expression to search multiple strings (Textpad)

To get the lines that contain the texts 8768, 9875 or 2353, use:

^.*(8768|9875|2353).*$

What it means:

^                      from the beginning of the line
.*                     get any character except \n (0 or more times)
(8768|9875|2353)       if the line contains the string '8768' OR '9875' OR '2353'
.*                     and get any character except \n (0 or more times)
$                      until the end of the line

If you do want the literal * char, you'd have to escape it:

^.*(\*8768|\*9875|\*2353).*$

How do we download a blob url video

I just came up with a general solution, which should work on most websites. I tried this on Chrome only, but this method should work with any other browser, though, as Dev Tools are pretty much the same in them all.

Steps:

Open the browser's Dev Tools (usually F12, or Ctrl-Shift-I, or right-click and then Inspect in the popup menu) on the page with the video you are interested in.
Go to Network tab and then reload the page. The tab will get populated with a list of requests (may be up to a hundred of them or even more).
Search through the names of requests and find the request with .m3u8 extension. There may be many of them, but most likely the first you find is the one you are looking for. It may have any name, e.g. playlist.m3u8.
Open the request and under Headers subsection you will see request's full URL in Request URL field. Copy it.
Extract the video from m3u8. There are many ways to do it, I'll give you those I tried, but you can google more by "download video from m3u8".
- Option 1. If you have VLC player installed, feed the URL to VLC using "Open Network Stream..." menu option. I'm not going to go into details on this part here, there are a number of comprehensive guides in many places, for example, here. If the page doesn't work, you can always google another one by "vlc download online video".
- Option 2. If you are more into command line, use FFMPEG or your own script, as directed in this SuperUser question.

SyntaxError: Use of const in strict mode?

I had a similar issue recently and ended up in this Q&A. This is not the solution the OP was looking for but may help others with a similar issue.

I'm using PM2 to run a project and in a given staging server I had a really old version of Node, NPM and PM2. I updated everything, however, I kept keeping the same error:

SyntaxError: Use of const in strict mode.

I tried to stop and start the application several times. Also tried to update everything again. Nothing worked. Until I noticed a warning when I ran pm2 start:

>>>> In-memory PM2 is out-of-date, do:
>>>> $ pm2 update
In memory PM2 version: 0.15.10
Local PM2 version: 3.2.9

Gotcha! After running pm2 update, I finally was able to get the application running as expected. No "const in strict mode" errors anymore.

DNS problem, nslookup works, ping doesn't

I had the same issue. As pointed out by other answers ping and nslookup use different mechanisms to lookup an ip.

Chances are you are trying to ping a machine not on the same domain. When you ping the fully qualified name of the server this should then work.

nslookup works:

PS C:\Users\Administrator> nslookup nuget
Server:  ad-01.docs.com
Address:  192.168.10.20

Name:    nuget.docs.com
Address:  192.168.10.17

Ping fails:

PS C:\Users\Administrator> ping nuget
Ping request could not find host nuget. Please check the name and try again.

Ping works, using FQDN:

PS C:\Users\Administrator> ping nuget.docs.com

Pinging nuget.docs.com [192.168.70.17] with 32 bytes of data:
Reply from 192.168.10.17: bytes=32 time=1ms TTL=127
Reply from 192.168.10.17: bytes=32 time=2ms TTL=127
Reply from 192.168.10.17: bytes=32 time=2ms TTL=127
Reply from 192.168.10.17: bytes=32 time=2ms TTL=127

Ping statistics for 192.168.10.17:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 1ms, Maximum = 2ms, Average = 1ms

To fix this you will need to alter the DNS setting for the machine and add the DNS suffix to lookup.

Control Panel\Network and Internet\Network Connections
Network adapter -> properties
IPV4 -> Properties
General tab -> Advanced
DNS Tab
Select "Append these DNS suffixes (in order)"
Add the required domain names
Disable, then enable your network adapter (don't do this on a VM, you'll loose your connection, instead try 'ipconfig /renew')

Advanced TCP/IP Settings

How to convert string to date to string in Swift iOS?

//String to Date Convert

var dateString = "2014-01-12"
var dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
let s = dateFormatter.dateFromString(dateString)
println(s)


//CONVERT FROM NSDate to String  

let date = NSDate()
var dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd" 
var dateString = dateFormatter.stringFromDate(date)
println(dateString)

How to sparsely checkout only one single file from a git repository?

If you have edited a local version of a file and wish to revert to the original version maintained on the central server, this can be easily achieved using Git Extensions.

Initially the file will be marked for commit, since it has been modified
Select (double click) the file in the file tree menu
The revision tree for the single file is listed.
Select the top/HEAD of the tree and right click save as
Save the file to overwrite the modified local version of the file
The file now has the correct version and will no longer be marked for commit!

Easy!

How do I authenticate a WebClient request?

You need to give the WebClient object the credentials. Something like this...

 WebClient client = new WebClient();
 client.Credentials = new NetworkCredential("username", "password");

How do I launch a program from command line without opening a new cmd window?

I got it working from qkzhu but instead of using MAX change it to MIN and window will close super fast.

@echo off
cd "C:\Program Files (x86)\MySQL\MySQL Server 5.6\bin"
:: Title not needed:
start /MIN  mysqld.exe
exit

MySQL error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near

You have to change delimiter before using triggers, stored procedures and so on.

delimiter //
create procedure ProG() 
begin 
SELECT * FROM hs_hr_employee_leave_quota;
end;//
delimiter ;

Disable dragging an image from an HTML page

CSS only solution: use pointer-events: none

https://developer.mozilla.org/en-US/docs/CSS/pointer-events

Update Fragment from ViewPager

Maybe your method for adding items into fragment should be public (placed in desired Fragment) and should have parameter the same type as selectedItems ..

That will make it visible from activity, which will have selectedItems array and voila..

p.s. better name it addItemsFromArray(typeOfSelectedItems[] pSelectedItems) cause name addItem() is quite undescriptive

Edit: stackoverflow just suggested similar topic :) Check here for detailed idea implementation.. :)

raw vs. html_safe vs. h to unescape html

Considering Rails 3:

html_safe actually "sets the string" as HTML Safe (it's a little more complicated than that, but it's basically it). This way, you can return HTML Safe strings from helpers or models at will.

h can only be used from within a controller or view, since it's from a helper. It will force the output to be escaped. It's not really deprecated, but you most likely won't use it anymore: the only usage is to "revert" an html_safe declaration, pretty unusual.

Prepending your expression with raw is actually equivalent to calling to_s chained with html_safe on it, but is declared on a helper, just like h, so it can only be used on controllers and views.

"SafeBuffers and Rails 3.0" is a nice explanation on how the SafeBuffers (the class that does the html_safe magic) work.

How to import a JSON file in ECMAScript 6?

I'm using

vuejs, version: 2.6.12
vuex, version: 3.6.0
vuex-i18n, version: 1.13.1.

My solution is:

messages.js:

import Vue from 'vue'
import Vuex from 'vuex';
import vuexI18n from 'vuex-i18n';
import translationsPl from './messages_pl'
import translationsEn from './messages_en'

Vue.use(Vuex);

export const messages = new Vuex.Store();

Vue.use(vuexI18n.plugin, messages);

Vue.i18n.add('en', translationsEn);
Vue.i18n.add('pl', translationsPl);

Vue.i18n.set('pl');

messages_pl.json:

{
    "loadingSpinner.text:"Ladowanie..."
}

messages_en.json:

{
    "loadingSpinner.default.text":"Loading..."
}

majn.js

import {messages} from './i18n/messages'
Vue.use(messages);

How to set proxy for wget?

In Debian Linux wget can be configured to use a proxy both via environment variables and via wgetrc. In both cases the variable names to be used for HTTP and HTTPS connections are

http_proxy=hostname_or_IP:portNumber
https_proxy=hostname_or_IP:portNumber

Note that the file /etc/wgetrc takes precedence over the environment variables, hence if your system has a proxy configured there and you try to use the environment variables, they would seem to have no effect!

How to make a Qt Widget grow with the window size?

The accepted answer (its image) is wrong, at least now in QT5. Instead you should assign a layout to the root object/widget (pointing to the aforementioned image, it should be the MainWindow instead of centralWidget). Also note that you must have at least one QObject created beneath it for this to work. Do this and your ui will become responsive to window resizing.

Android Studio : How to uninstall APK (or execute adb command) automatically before Run or Debug?

This command with --user 0 do the job:

adb uninstall --user 0 <package_name>

Difference between "managed" and "unmanaged"

This is more general than .NET and Windows. Managed is an environment where you have automatic memory management, garbage collection, type safety, ... unmanaged is everything else. So for example .NET is a managed environment and C/C++ is unmanaged.

Creating SVG elements dynamically with javascript inside HTML

Add this to html:

<svg id="mySVG" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"/>

Try this function and adapt for you program:

var svgNS = "http://www.w3.org/2000/svg";  

function createCircle()
{
    var myCircle = document.createElementNS(svgNS,"circle"); //to create a circle. for rectangle use "rectangle"
    myCircle.setAttributeNS(null,"id","mycircle");
    myCircle.setAttributeNS(null,"cx",100);
    myCircle.setAttributeNS(null,"cy",100);
    myCircle.setAttributeNS(null,"r",50);
    myCircle.setAttributeNS(null,"fill","black");
    myCircle.setAttributeNS(null,"stroke","none");

    document.getElementById("mySVG").appendChild(myCircle);
}

Pass accepts header parameter to jquery ajax

Try this:

$.ajax({
        beforeSend: function (xhr){ 
        xhr.setRequestHeader("Content-Type","application/json");
        xhr.setRequestHeader("Accept","text/json");
    }, 
    type: "POST",
    //........
});

Recommended SQL database design for tags or tagging

I've always kept the tags in a separate table and then had a mapping table. Of course I've never done anything on a really large scale either.

Having a "tags" table and a map table makes it pretty trivial to generate tag clouds & such since you can easily put together SQL to get a list of tags with counts of how often each tag is used.

Programmatically generate video or animated GIF in Python?

Well, now I'm using ImageMagick. I save my frames as PNG files and then invoke ImageMagick's convert.exe from Python to create an animated GIF. The nice thing about this approach is I can specify a frame duration for each frame individually. Unfortunately this depends on ImageMagick being installed on the machine. They have a Python wrapper but it looks pretty crappy and unsupported. Still open to other suggestions.

Selecting specific rows and columns from NumPy array

As Toan suggests, a simple hack would be to just select the rows first, and then select the columns over that.

>>> a[[0,1,3], :]            # Returns the rows you want
array([[ 0,  1,  2,  3],
       [ 4,  5,  6,  7],
       [12, 13, 14, 15]])
>>> a[[0,1,3], :][:, [0,2]]  # Selects the columns you want as well
array([[ 0,  2],
       [ 4,  6],
       [12, 14]])

[Edit] The built-in method: `np.ix_`

I recently discovered that numpy gives you an in-built one-liner to doing exactly what @Jaime suggested, but without having to use broadcasting syntax (which suffers from lack of readability). From the docs:

Using ix_ one can quickly construct index arrays that will index the cross product. a[np.ix_([1,3],[2,5])] returns the array [[a[1,2] a[1,5]], [a[3,2] a[3,5]]].

So you use it like this:

>>> a = np.arange(20).reshape((5,4))
>>> a[np.ix_([0,1,3], [0,2])]
array([[ 0,  2],
       [ 4,  6],
       [12, 14]])

And the way it works is that it takes care of aligning arrays the way Jaime suggested, so that broadcasting happens properly:

>>> np.ix_([0,1,3], [0,2])
(array([[0],
        [1],
        [3]]), array([[0, 2]]))

Also, as MikeC says in a comment, np.ix_ has the advantage of returning a view, which my first (pre-edit) answer did not. This means you can now assign to the indexed array:

>>> a[np.ix_([0,1,3], [0,2])] = -1
>>> a    
array([[-1,  1, -1,  3],
       [-1,  5, -1,  7],
       [ 8,  9, 10, 11],
       [-1, 13, -1, 15],
       [16, 17, 18, 19]])

Is there a way to view past mysql queries with phpmyadmin?

There is a tool called Adminer which is capable of doing all phpmyadmin job packed in single tiny php file. http://www.techinfobit.com/how-to-import-export-database-without-any-extra-installation/

How to append strings using sprintf?

I find the following method works nicely.

sprintf(Buffer,"Hello World");
sprintf(&Buffer[strlen[Buffer]],"Good Morning");
sprintf(&Buffer[strlen[Buffer]],"Good Afternoon");

Format date to MM/dd/yyyy in JavaScript

ISO compliant dateString

If your dateString is RFC282 and ISO8601 compliant:
pass your string into the Date Constructor:

const dateString = "2020-10-30T12:52:27+05:30"; // ISO8601 compliant dateString
const D = new Date(dateString);                 // {object Date}

from here you can extract the desired values by using Date Getters:

D.getMonth() + 1  // 10 (PS: +1 since Month is 0-based)
D.getDate()       // 30
D.getFullYear()   // 2020

Non-standard date string

If you use a non standard date string:
destructure the string into known parts, and than pass the variables to the Date Constructor:

new Date(year, monthIndex [, day [, hours [, minutes [, seconds [, milliseconds]]]]])

const dateString = "30/10/2020 12:52:27";
const [d, M, y, h, m, s] = dateString.match(/\d+/g);

// PS: M-1 since Month is 0-based
const D = new Date(y, M-1, d, h, m, s);  // {object Date}


D.getMonth() + 1  // 10 (PS: +1 since Month is 0-based)
D.getDate()       // 30
D.getFullYear()   // 2020

How to change text color and console color in code::blocks?

You can also use rlutil:

cross platform,
header only (rlutil.h),
works for C and C++,
implements setColor(), cls(), getch(), gotoxy(), etc.
License: WTFPL

Your code would become something like this:

#include <stdio.h>

#include "rlutil.h"

int main(int argc, char* argv[])
{
    setColor(BLUE);
    printf("\n \n \t This is dummy program for text color ");
    getch();

    return 0;
}

Have a look at example.c and test.cpp for C and C++ examples.

How do I get first element rather than using [0] in jQuery?

You can use the first method:

$('li').first()

http://api.jquery.com/first/

btw I agree with Nick Craver -- use document.getElementById()...

Gson - convert from Json to a typed ArrayList<T>

You may use TypeToken to load the json string into a custom object.

logs = gson.fromJson(br, new TypeToken<List<JsonLog>>(){}.getType());

Documentation:

Represents a generic type T.

Java doesn't yet provide a way to represent generic types, so this class does. Forces clients to create a subclass of this class which enables retrieval the type information even at runtime.

For example, to create a type literal for List<String>, you can create an empty anonymous inner class:

TypeToken<List<String>> list = new TypeToken<List<String>>() {};

This syntax cannot be used to create type literals that have wildcard parameters, such as Class<?> or List<? extends CharSequence>.

Kotlin:

If you need to do it in Kotlin you can do it like this:

val myType = object : TypeToken<List<JsonLong>>() {}.type
val logs = gson.fromJson<List<JsonLong>>(br, myType)

Or you can see this answer for various alternatives.

string.Replace in AngularJs

The easiest way is:

var oldstr="Angular isn't easy";
var newstr=oldstr.toString().replace("isn't","is");

Which Radio button in the group is checked?

The OP wanted to get the checked RadioButton BY GROUP. While @SLaks' answer is excellent, it doesn't really answer the OP's main question. To improve on @SLaks' answer, just take the LINQ one step further.

Here's an example from my own working code. Per normal WPF, my RadioButtons are contained in a Grid (named "myGrid") with a bunch of other types of controls. I have two different RadioButton groups in the Grid.

To get the checked RadioButton from a particular group:

List<RadioButton> radioButtons = myGrid.Children.OfType<RadioButton>().ToList();
RadioButton rbTarget = radioButtons
      .Where(r => r.GroupName == "GroupName" && r.IsChecked)
      .Single();

If your code has the possibility of no RadioButtons being checked, then use SingleOrDefault() (If I'm not using tri-state buttons, then I always set one button "IsChecked" as a default selection.)

Updating an object with setState in React

Simple and dynamic way.

This will do the job, but you need to set all the ids to the parent so the parent will point to the name of the object, being id = "jasper" and name the name of the input element = property inside of the object jasper.

handleChangeObj = ({target: { id , name , value}}) => this.setState({ [id]: { ...this.state[id] , [name]: value } });

How do I get whole and fractional parts from double in JSP/Java?

Since this 1-year old question was kicked up by someone who corrected the question subject, and this question is been tagged with jsp, and nobody here was able to give a JSP targeted answer, here is my JSP-targeted contribution.

Use JSTL (just drop jstl-1.2.jar in /WEB-INF/lib) fmt taglib. There's a <fmt:formatNumber> tag which does exactly what you want and in a quite easy manner with help of maxFractionDigits and maxIntegerDigits attributes.

Here's an SSCCE, just copy'n'paste'n'run it.

<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>

<%
    // Just for quick prototyping. Don't do this in real! Use servlet/javabean.
    double d = 3.25;
    request.setAttribute("d", d);
%>

<!doctype html>
<html lang="en">
    <head>
        <title>SO question 343584</title>
    </head>
    <body>
        <p>Whole: <fmt:formatNumber value="${d}" maxFractionDigits="0" />
        <p>Fraction: <fmt:formatNumber value="${d}" maxIntegerDigits="0" />
    </body>
</html>

Output:

Whole: 3

Fraction: .25

That's it. No need to massage it with help of raw Java code.

Difference between links and depends_on in docker_compose.yml

[Update Sep 2016]: This answer was intended for docker compose file v1 (as shown by the sample compose file below). For v2, see the other answer by @Windsooon.

[Original answer]:

It is pretty clear in the documentation. depends_on decides the dependency and the order of container creation and links not only does these, but also

Containers for the linked service will be reachable at a hostname identical to the alias, or the service name if no alias was specified.

For example, assuming the following docker-compose.yml file:

web:
  image: example/my_web_app:latest
  links:
    - db
    - cache

db:
  image: postgres:latest

cache:
  image: redis:latest

With links, code inside web will be able to access the database using db:5432, assuming port 5432 is exposed in the db image. If depends_on were used, this wouldn't be possible, but the startup order of the containers would be correct.

Add new column with foreign key constraint in one command

ALTER TABLE TableName ADD NewColumnName INTEGER, FOREIGN KEY(NewColumnName) REFERENCES [ForeignKey_TableName](Foreign_Key_Column)

Flexbox not working in Internet Explorer 11

See "Can I Use" for the full list of IE11 Flexbox bugs and more

There are numerous Flexbox bugs in IE11 and other browsers - see flexbox on Can I Use -> Known Issues, where the following are listed under IE11:

IE 11 requires a unit to be added to the third argument, the flex-basis property
In IE10 and IE11, containers with display: flex and flex-direction: column will not properly calculate their flexed childrens' sizes if the container has min-height but no explicit height property
IE 11 does not vertically align items correctly when min-height is used

Also see Philip Walton's Flexbugs list of issues and workarounds.

Are table names in MySQL case sensitive?

It depends upon lower_case_table_names system variable:

show variables where Variable_name='lower_case_table_names'

There are three possible values for this:

0 - lettercase specified in the CREATE TABLE or CREATE DATABASE statement. Name comparisons are case sensitive.
1 - Table names are stored in lowercase on disk and name comparisons are not case sensitive.
2 - lettercase specified in the CREATE TABLE or CREATE DATABASE statement, but MySQL converts them to lowercase on lookup. Name comparisons are not case sensitive.

Documentation

How do I tell if .NET 3.5 SP1 is installed?

Use Add/Remove programs from the Control Panel.

How to define a variable in a Dockerfile?

You can use ARG - see https://docs.docker.com/engine/reference/builder/#arg

The ARG instruction defines a variable that users can pass at build-time to the builder with the docker build command using the --build-arg <varname>=<value> flag. If a user specifies a build argument that was not defined in the Dockerfile, the build outputs an error.

java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)

If you are connecting a remote mysql server from your local machine using java see the below steps. Error : "java.sql.SQLException: Access denied for user 'xxxxx'@'101.123.163.141' (using password: YES) "

for remote access may be cpanel or others grant the remote access for your local ip address.

In the above error message: "101.123.163.141" is my local machine ip. So First we have to give remote access in the Cpanel-> Remote MySQL®. Then run your application to connect.

Class.forName("com.mysql.jdbc.Driver");  
Connection con=DriverManager.getConnection(  
    "jdbc:mysql://www.xyz.com/abc","def","ghi");  
//here abc is database name, def is username and ghi        
Statement stmt=con.createStatement();  
ResultSet rs=stmt.executeQuery("select * from employee");  
    while(rs.next())  
        System.out.println(rs.getInt(1)+" "+rs.getString(2)+"  
                          "+rs.getString(3));  
con.close();

Hope it will resolve your issue.

Thanks

Delete entire row if cell contains the string X

I'd like to add to @MBK's answer. Although I found @MBK's answer to be very helpful in solving a similar problem, it'd be better if @MBK included a screenshot of how to filter a particular column.

Error in Python IOError: [Errno 2] No such file or directory: 'data.csv'

Try to give the full path to your csv file

open('/users/gcameron/Desktop/map/data.csv')

The python process is looking for file in the directory it is running from.

Fastest way to check if a string is JSON in PHP?

The fastest way is to "maybe decode" the possible JSON string

Is this really the fastest method?

If you want to decode complex objects or larger arrays, this is the fastest way, by far!

If your json string contains short values (like scalars or objects with only 1-2 attributes) then all solutions in this SO questions come to a similar performance.

Here is a performance comparison that I've done with some dummy and real-live JSON values:

PHP version: 7.4.12
1 | Duration: 1.5828 sec | 60,000 calls | json_last_error() == JSON_ERROR_NONE
2 | Duration: 1.5202 sec | 60,000 calls | is_object( json_decode() )
3 | Duration: 1.5400 sec | 60,000 calls | json_decode() && $res != $string
4 | Duration: 1.3536 sec | 60,000 calls | preg_match()
5 | Duration: 0.2261 sec | 60,000 calls | "maybe decode" approach

The last line is the code from this answer, which is the "maybe decode" approach.

Here is the performance comparison script, there you can see the test-data I used for the comparison: https://gist.github.com/stracker-phil/6a80e6faedea8dab090b4bf6668ee461

The "maybe decode" logic/code

We first perform some type checks and string comparisons before attempting to decode the JSON string. This gives us the best performance because json_decode() can be slow.

/**
 * Returns true, when the given parameter is a valid JSON string.
 */
function is_json( $value ) {
    // A non-string value can never be a JSON string.
    if ( ! is_string( $value ) ) { return false; }

    // Numeric strings are always valid JSON.
    if ( is_numeric( $value ) ) { return true; }

    // Any non-numeric JSON string must be longer than 2 characters.
    if ( strlen( $value ) < 2 ) { return false; }

    // "null" is valid JSON string.
    if ( 'null' === $value ) { return true; }

    // "true" and "false" are valid JSON strings.
    if ( 'true' === $value ) { return true; }
    if ( 'false' === $value ) { return false; }

    // Any other JSON string has to be wrapped in {}, [] or "".
    if ( '{' != $value[0] && '[' != $value[0] && '"' != $value[0] ) { return false; }

    // Note the last param (1), this limits the depth to the first level.
    $json_data = json_decode( $value, null, 1 );

    // When json_decode fails, it returns NULL.
    if ( is_null( $json_data ) ) { return false; }
    return true;
}

Extra: Use this logic to safely double-decode JSON

This function uses the same logic but either returns the decoded JSON object or the original value.

I use this function in a parser that recursively decodes a complex object. Some attributes might be decoded already by an earlier iteration. That function recognizes this and does not attempt to double decode the value again.

/**
 * Tests, if the given $value parameter is a JSON string.
 * When it is a valid JSON value, the decoded value is returned.
 * When the value is no JSON value (i.e. it was decoded already), then 
 * the original value is returned.
 */
function get_data( $value, $as_object = false ) {
    if ( ! is_string( $value ) ) { return $value; }
    if ( is_numeric( $value ) ) { return 0 + $value; }
    if ( strlen( $value ) < 2 ) { return $value; }
    if ( 'null' === $value ) { return null; }
    if ( 'true' === $value ) { return true; }
    if ( 'false' === $value ) { return false; }
    if ( '{' != $value[0] && '[' != $value[0] && '"' != $value[0] ) { return $value; }

    $json_data = json_decode( $value, $as_object );
    if ( is_null( $json_data ) ) { return $value; }
    return $json_data;
}

Note: When passing a non-string to any other solution in this SO question, you will get dramatically degraded performance + wrong return values (or even fatal errors). This code is bulletproof and highly performant.

How to remove backslash on json_encode() function?

I just figured out that json_encode does only escape \n if it's used within single quotes.

echo json_encode("Hello World\n");
// results in "Hello World\n"

And

echo json_encode('Hello World\n');
// results in "Hello World\\\n"

Argument Exception "Item with Same Key has already been added"

To illustrate the problem you are having, let's look at some code...

Dictionary<string, string> test = new Dictionary<string, string>();

test.Add("Key1", "Value1");  // Works fine
test.Add("Key2", "Value2");  // Works fine
test.Add("Key1", "Value3");  // Fails because of duplicate key

The reason that a dictionary has a key/value pair is a feature so you can do this...

var myString = test["Key2"];  // myString is now Value2.

If Dictionary had 2 Key2's, it wouldn't know which one to return, so it limits you to a unique key.

In MS DOS copying several files to one file

copy *.csv new.csv

No need for /b as csv isn't a binary file type.

How to change the pop-up position of the jQuery DatePicker control

I took it from ((How to control positioning of jQueryUI datepicker))

$.extend($.datepicker, { 
    _checkOffset: function(inst, offset, isFixed) { 
        return offset 
    } 
});

it works !!!

JavaScript console.log causes error: "Synchronous XMLHttpRequest on the main thread is deprecated..."

Like @Nycen I also got this error because of a link to Cloudfare. Mine was for the Select2 plugin.

to fix it I just removed

 src="//cdnjs.cloudflare.com/ajax/libs/select2/4.0.0/js/select2.min.js"

and the error went away.

How to add an empty column to a dataframe?

The reason I was looking for such a solution is simply to add spaces between multiple DFs which have been joined column-wise using the pd.concat function and then written to excel using xlsxwriter.

df[' ']=df.apply(lambda _: '', axis=1)
df_2 = pd.concat([df,df1],axis=1)                #worked but only once. 
# Note: df & df1 have the same rows which is my index. 
#
df_2[' ']=df_2.apply(lambda _: '', axis=1)       #didn't work this time !!?     
df_4 = pd.concat([df_2,df_3],axis=1)

I then replaced the second lambda call with

df_2['']=''                                 #which appears to add a blank column
df_4 = pd.concat([df_2,df_3],axis=1)

The output I tested it on was using xlsxwriter to excel. Jupyter blank columns look the same as in excel although doesnt have xlsx formatting. Not sure why the second Lambda call didnt work.

How to negate code in "if" statement block in JavaScript -JQuery like 'if not then..'

You can use the Logical NOT ! operator:

if (!$(this).parent().next().is('ul')){

Or equivalently (see comments below):

if (! ($(this).parent().next().is('ul'))){

For more information, see the Logical Operators section of the MDN docs.

Select all occurrences of selected word in VSCode

Ctrl + F2 works for me in Windows 10.

Ctrl + Shift + L starts performance logging

How to add to the PYTHONPATH in Windows, so it finds my modules/packages?

import sys
sys.path.append("path/to/Modules")
print sys.path

This won't persist over reboots or get translated to other files. It is however great if you don't want to make a permanent modification to your system.

Which is the best IDE for Python For Windows

Python is dynamic language so the IDE can do only so much in terms of code intelligence and syntax checking but I personally recommend Komode IDE, it's pretty slick on OS/X and Windows. I've experienced high cpu use with Linux but not sure if it's caused by my VirtualBox environment.

You can also try Eclipse with PyDev plugin. It's heavier so performance might become a problem though.

How should I do integer division in Perl?

you can:

use integer;

it is explained by Michael Ratanapintha or else use manually:

$a=3.7;
$b=2.1;

$c=int(int($a)/int($b));

notice, 'int' is not casting. this is function for converting number to integer form. this is because Perl 5 does not have separate integer division. exception is when you 'use integer'. Then you will lose real division.

Parsing a pcap file in python

I would use python-dpkt. Here is the documentation: http://www.commercialventvac.com/dpkt.html

This is all I know how to do though sorry.

#!/usr/local/bin/python2.7

import dpkt

counter=0
ipcounter=0
tcpcounter=0
udpcounter=0

filename='sampledata.pcap'

for ts, pkt in dpkt.pcap.Reader(open(filename,'r')):

    counter+=1
    eth=dpkt.ethernet.Ethernet(pkt) 
    if eth.type!=dpkt.ethernet.ETH_TYPE_IP:
       continue

    ip=eth.data
    ipcounter+=1

    if ip.p==dpkt.ip.IP_PROTO_TCP: 
       tcpcounter+=1

    if ip.p==dpkt.ip.IP_PROTO_UDP:
       udpcounter+=1

print "Total number of packets in the pcap file: ", counter
print "Total number of ip packets: ", ipcounter
print "Total number of tcp packets: ", tcpcounter
print "Total number of udp packets: ", udpcounter

Update:

Project on GitHub, documentation here

Finding version of Microsoft C++ compiler from command-line (for makefiles)

Create a .c file containing just the line:

_MSC_VER

CompilerVersion=_MSC_VER

then pre-process with

cl /nologo /EP <filename>.c

It is easy to parse the output.

Can't bind to 'formGroup' since it isn't a known property of 'form'

RC5 FIX

You need to import { REACTIVE_FORM_DIRECTIVES } from '@angular/forms' in your controller and add it to directives in @Component. That will fix the problem.

After you fix that, you will probably get another error because you didn't add formControlName="name" to your input in form.

RC6/RC7/Final release FIX

To fix this error, you just need to import ReactiveFormsModule from @angular/forms in your module. Here's the example of a basic module with ReactiveFormsModule import:

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { AppComponent }  from './app.component';

@NgModule({
    imports: [
        BrowserModule,
        FormsModule,
        ReactiveFormsModule
    ],
    declarations: [
        AppComponent
    ],
    bootstrap: [AppComponent]
})

export class AppModule { }

To explain further, formGroup is a selector for directive named FormGroupDirective that is a part of ReactiveFormsModule, hence the need to import it. It is used to bind an existing FormGroup to a DOM element. You can read more about it on Angular's official docs page.

WaitAll vs WhenAll

Task.WaitAll blocks the current thread until everything has completed.

Task.WhenAll returns a task which represents the action of waiting until everything has completed.

That means that from an async method, you can use:

await Task.WhenAll(tasks);

... which means your method will continue when everything's completed, but you won't tie up a thread to just hang around until that time.

get unique machine id

The following site uses System.Management to accomplish the same is a very sleek way in a console application

make: Nothing to be done for `all'

Remove the hello file from your folder and try again.

The all target depends on the hello target. The hello target first tries to find the corresponding file in the filesystem. If it finds it and it is up to date with the dependent files—there is nothing to do.

Stopping an Android app from console

Edit: Long after I wrote this post and it was accepted as the answer, the am force-stop command was implemented by the Android team, as mentioned in this answer.

Alternatively: Rather than just stopping the app, since you mention wanting a "clean slate" for each test run, you can use adb shell pm clear com.my.app.package, which will stop the app process and clear out all the stored data for that app.

If you're on Linux:
adb shell ps | grep com.myapp | awk '{print $2}' | xargs adb shell kill

That will only work for devices/emulators where you have root immediately upon running a shell. That can probably be refined slightly to call su beforehand.

Otherwise, you can do (manually, or I suppose scripted):
pc $ adb -d shell
android $ su
android # ps
android # kill <process id from ps output>

Why is it important to override GetHashCode when Equals method is overridden?

Please don´t forget to check the obj parameter against null when overriding Equals(). And also compare the type.

public override bool Equals(object obj)
{
    Foo fooItem = obj as Foo;

    if (fooItem == null)
    {
       return false;
    }

    return fooItem.FooId == this.FooId;
}

The reason for this is: Equals must return false on comparison to null. See also http://msdn.microsoft.com/en-us/library/bsc2ak47.aspx

How to select Multiple images from UIImagePickerController

You can't use UIImagePickerController, but you can use a custom image picker. I think ELCImagePickerController is the best option, but here are some other libraries you could use:

Objective-C
1. ELCImagePickerController
2. WSAssetPickerController
3. QBImagePickerController
4. ZCImagePickerController
5. CTAssetsPickerController
6. AGImagePickerController
7. UzysAssetsPickerController
8. MWPhotoBrowser
9. TSAssetsPickerController
10. CustomImagePicker
11. InstagramPhotoPicker
12. GMImagePicker
13. DLFPhotosPicker
14. CombinationPickerController
15. AssetPicker
16. BSImagePicker
17. SNImagePicker
18. DoImagePickerController
19. grabKit
20. IQMediaPickerController
21. HySideScrollingImagePicker
22. MultiImageSelector
23. TTImagePicker
24. SelectImages
25. ImageSelectAndSave
26. imagepicker-multi-select
27. MultiSelectImagePickerController
28. YangMingShan(Yahoo like image selector)
29. DBAttachmentPickerController
30. BRImagePicker
31. GLAssetGridViewController
32. CreolePhotoSelection

Swift
1. LimPicker (Similar to WhatsApp's image picker)
2. RMImagePicker
3. DKImagePickerController
4. BSImagePicker
5. Fusuma(Instagram like image selector)
6. YangMingShan(Yahoo like image selector)
7. NohanaImagePicker
8. ImagePicker
9. OpalImagePicker
10. TLPhotoPicker
11. AssetsPickerViewController
12. Alerts-and-pickers/Telegram Picker

Thanx to @androidbloke,
I have added some library that I know for multiple image picker in swift.
Will update list as I find new ones.
Thank You.

Error: Cannot find module '../lib/utils/unsupported.js' while using Ionic

Tried all above/older brew installation answers, none is working for my laptop.

Only below method could fix my issue.

1) Run following commands:

sudo rm -rf /usr/local/lib/node_modules/npm
brew uninstall --force node

2) Then, proceed to Node.js Official Website https://nodejs.org/en/download/current/ to download latest package for new installation.

3) Run your npm command again, which should longer have any errors.

This method is working on macOS Mojave Version 10.14.4.

Multiple bluetooth connection

Not exactly true -- take a look at the specs summary

Logical link control and adaptation protocol (L2CAP)

L2CAP is used within the Bluetooth protocol stack. It passes packets to either the Host Controller Interface (HCI) or on a hostless system, directly to the Link Manager/ACL link. L2CAP's functions include:

Multiplexing data between different higher layer protocols.
Segmentation and reassembly of packets.
Providing one-way transmission management of multicast data to a group of other Bluetooth devices.
Quality of service (QoS) management for higher layer protocols.

L2CAP is used to communicate over the host ACL link. Its connection is established after the ACL link has been set up.

Understanding repr( ) function in Python

When you say

foo = 'bar'
baz(foo)

you are not passing foo to the baz function. foo is just a name used to represent a value, in this case 'bar', and that value is passed to the baz function.

C pointer to array/array of pointers disambiguation

I don't know if it has an official name, but I call it the Right-Left Thingy(TM).

Start at the variable, then go right, and left, and right...and so on.

int* arr1[8];

arr1 is an array of 8 pointers to integers.

int (*arr2)[8];

arr2 is a pointer (the parenthesis block the right-left) to an array of 8 integers.

int *(arr3[8]);

arr3 is an array of 8 pointers to integers.

This should help you out with complex declarations.

Difference between adjustResize and adjustPan in android?

From the Android Developer Site link

"adjustResize"

The activity's main window is always resized to make room for the soft keyboard on screen.

"adjustPan"

The activity's main window is not resized to make room for the soft keyboard. Rather, the contents of the window are automatically panned so that the current focus is never obscured by the keyboard and users can always see what they are typing. This is generally less desirable than resizing, because the user may need to close the soft keyboard to get at and interact with obscured parts of the window.

according to your comment, use following in your activity manifest

<activity android:windowSoftInputMode="adjustResize"> </activity>

When using SASS how can I import a file from a different directory?

The best way is to user sass-loader. It is available as npm package. It resolves all path related issues and make it super easy.

How to print a specific row of a pandas DataFrame?

To print a specific row we have couple of pandas method

loc - It only get label i.e column name or Features
iloc - Here i stands for integer, actually row number
ix - It is a mix of label as well as integer

How to use for specific row

loc

df.loc[row,column]

For first row and all column

df.loc[0,:]

For first row and some specific column

df.loc[0,'column_name']

iloc

For first row and all column

df.iloc[0,:]

For first row and some specific column i.e first three cols

df.iloc[0,0:3]

How to convert an ArrayList containing Integers to primitive int array?

It bewilders me that we encourage one-off custom methods whenever a perfectly good, well used library like Apache Commons has solved the problem already. Though the solution is trivial if not absurd, it is irresponsible to encourage such a behavior due to long term maintenance and accessibility.

Just go with Apache Commons

How to embed small icon in UILabel

Swift 3 UILabel extention

Tip: If you need some space between the image and the text just use a space or two before the labelText.

extension UILabel {
    func addIconToLabel(imageName: String, labelText: String, bounds_x: Double, bounds_y: Double, boundsWidth: Double, boundsHeight: Double) {
        let attachment = NSTextAttachment()
        attachment.image = UIImage(named: imageName)
        attachment.bounds = CGRect(x: bounds_x, y: bounds_y, width: boundsWidth, height: boundsHeight)
        let attachmentStr = NSAttributedString(attachment: attachment)
        let string = NSMutableAttributedString(string: "")
        string.append(attachmentStr)
        let string2 = NSMutableAttributedString(string: labelText)
        string.append(string2)
        self.attributedText = string
    }
}

"Notice: Undefined variable", "Notice: Undefined index", and "Notice: Undefined offset" using PHP

I use all time own useful function exst() which automatically declare variables.

Your code will be -

$greeting = "Hello, ".exst($user_name, 'Visitor')." from ".exst($user_location);


/** 
 * Function exst() - Checks if the variable has been set 
 * (copy/paste it in any place of your code)
 * 
 * If the variable is set and not empty returns the variable (no transformation)
 * If the variable is not set or empty, returns the $default value
 *
 * @param  mixed $var
 * @param  mixed $default
 * 
 * @return mixed 
 */

function exst( & $var, $default = "")
{
    $t = "";
    if ( !isset($var)  || !$var ) {
        if (isset($default) && $default != "") $t = $default;
    }
    else  {  
        $t = $var;
    }
    if (is_string($t)) $t = trim($t);
    return $t;
}

Twitter Bootstrap Multilevel Dropdown Menu

I just added class="span2" to the <li> for the dropdown items and that worked.

Return array in a function

to return an array from a function , let us define that array in a structure; So it looks something like this

struct Marks{
   int list[5];
}

Now let us create variables of the type structure.

typedef struct Marks marks;
marks marks_list;

We can pass array to a function in the following way and assign value to it:

void setMarks(int marks_array[]){
   for(int i=0;i<sizeof(marks_array)/sizeof(int);i++)
       marks_list.list[i]=marks_array[i];
}

We can also return the array. To return the array , the return type of the function should be of structure type ie marks. This is because in reality we are passing the structure that contains the array. So the final code may look like this.

marks getMarks(){
 return marks_list;
}

How can I play sound in Java?

I didn't want to have so many lines of code just to play a simple damn sound. This can work if you have the JavaFX package (already included in my jdk 8).

private static void playSound(String sound){
    // cl is the ClassLoader for the current class, ie. CurrentClass.class.getClassLoader();
    URL file = cl.getResource(sound);
    final Media media = new Media(file.toString());
    final MediaPlayer mediaPlayer = new MediaPlayer(media);
    mediaPlayer.play();
}

Notice : You need to initialize JavaFX. A quick way to do that, is to call the constructor of JFXPanel() once in your app :

static{
    JFXPanel fxPanel = new JFXPanel();
}

Changing default startup directory for command prompt in Windows 7

On Windows Start Menu, right click on Command Prompt.

Click on "Properties".

"Command Prompt Properties" dialog box opens.

Edit the field "Start in " to a location where you want to start the command prompt.

Example: Chand %HOMEDRIVE%%HOMEPATH% to D:\PersonalPrograms.

Next time when you start command prompt the start up directory will be D:\PersonalPrograms

How can I filter a Django query with a list of values?

jQuery - Detecting if a file has been selected in the file input

I'd suggest try the change event? test to see if it has a value if it does then you can continue with your code. jQuery has

.bind("change", function(){ ... });

.change(function(){ ... });

which are equivalents.

http://api.jquery.com/change/

for a unique selector change your name attribute to id and then jQuery("#imafile") or a general jQuery('input[type="file"]') for all the file inputs

How can I remove or replace SVG content?

Setting the id attribute when appending the svg element can also let d3 select so remove() later on this element by id :

var svg = d3.select("theParentElement").append("svg")
.attr("id","the_SVG_ID")
.attr("width",...

...

d3.select("#the_SVG_ID").remove();

Java how to replace 2 or more spaces with single space in string and delete leading and trailing spaces

String blogName = "how to   do    in  java   .         com"; 
 
String nameWithProperSpacing = blogName.replaceAll("\\\s+", " ");

MD5 hashing in Android

The androidsnippets.com code does not work reliably because 0's seem to be cut out of the resulting hash.

A better implementation is here.

public static String MD5_Hash(String s) {
    MessageDigest m = null;

    try {
            m = MessageDigest.getInstance("MD5");
    } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
    }

    m.update(s.getBytes(),0,s.length());
    String hash = new BigInteger(1, m.digest()).toString(16);
    return hash;
}

Transposing a 2D-array in JavaScript

Edit: This answer would not transpose the matrix, but rotate it. I didn't read the question carefully in the first place :D

clockwise and counterclockwise rotation:

    function rotateCounterClockwise(a){
        var n=a.length;
        for (var i=0; i<n/2; i++) {
            for (var j=i; j<n-i-1; j++) {
                var tmp=a[i][j];
                a[i][j]=a[j][n-i-1];
                a[j][n-i-1]=a[n-i-1][n-j-1];
                a[n-i-1][n-j-1]=a[n-j-1][i];
                a[n-j-1][i]=tmp;
            }
        }
        return a;
    }

    function rotateClockwise(a) {
        var n=a.length;
        for (var i=0; i<n/2; i++) {
            for (var j=i; j<n-i-1; j++) {
                var tmp=a[i][j];
                a[i][j]=a[n-j-1][i];
                a[n-j-1][i]=a[n-i-1][n-j-1];
                a[n-i-1][n-j-1]=a[j][n-i-1];
                a[j][n-i-1]=tmp;
            }
        }
        return a;
    }

How to convert DateTime to a number with a precision greater than days in T-SQL?

If the purpose of this is to create a unique value from the date, here is what I would do

DECLARE @ts TIMESTAMP 
SET @ts = CAST(getdate() AS TIMESTAMP)
SELECT @ts

This gets the date and declares it as a simple timestamp

Ball to Ball Collision - Detection and Handling

I found an excellent page with information on collision detection and response in 2D.

http://www.metanetsoftware.com/technique.html (web.archive.org)

They try to explain how it's done from an academic point of view. They start with the simple object-to-object collision detection, and move on to collision response and how to scale it up.

Edit: Updated link

How to empty the content of a div

In jQuery it would be as simple as $('#yourDivID').empty()

See the documentation.

Resize HTML5 canvas to fit window

A pure CSS approach adding to solution of @jerseyboy above.
Works in Firefox (tested in v29), Chrome (tested in v34) and Internet Explorer (tested in v11).

<!DOCTYPE html>
<html>
    <head>
    <style>
        html,
        body {
            width: 100%;
            height: 100%;
            margin: 0;
        }
        canvas {
            background-color: #ccc;
            display: block;
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            width: 100%;
            height: 100%;
        }
    </style>
</head>
<body>
    <canvas id="canvas" width="500" height="500"></canvas>
    <script>
        var canvas = document.getElementById('canvas');
        if (canvas.getContext) {
            var ctx = canvas.getContext('2d');
            ctx.fillRect(25,25,100,100);
            ctx.clearRect(45,45,60,60);
            ctx.strokeRect(50,50,50,50);
        }
    </script>
</body>
</html>

Link to the example: http://temporaer.net/open/so/140502_canvas-fit-to-window.html

But take care, as @jerseyboy states in his comment:

Rescaling canvas with CSS is troublesome. At least on Chrome and Safari, mouse/touch event positions will not correspond 1:1 with canvas pixel positions, and you'll have to transform the coordinate systems.

insert echo into the specific html element like div which has an id or class

You can write the php code in another file and include it in the proper place where you want it.

AJAX is also used to display HTML content that is formed by PHP into a specified HTML tag.

Using jQuery:

$.ajax({url: "test.php"}).done(function( html ) {
    $("#results").append(html);
});

Above code will execute test.php and result will be displayed in the element with id results.

Cannot connect to Database server (mysql workbench)

Did you try to determine if this is a problem with Workbench or a general connection problem? Try this:

Open a terminal
Type mysql -u root -p -h 127.0.0.1 -P 3306
If you can connect successfully you will see a mysql prompt after you type your password (type quit and Enter there to exit).

Report back how this worked.

How to use curl in a shell script?

Firstly, your example is looking quite correct and works well on my machine. You may go another way.

curl $CURLARGS $RVMHTTP > ./install.sh

All output now storing in ./install.sh file, which you can edit and execute.

Makefile to compile multiple C programs?

A simple program's compilation workflow is simple, I can draw it as a small graph: source -> [compilation] -> object [linking] -> executable. There are files (source, object, executable) in this graph, and rules (make's terminology). That graph is definied in the Makefile.

When you launch make, it reads Makefile, and checks for changed files. If there's any, it triggers the rule, which depends on it. The rule may produce/update further files, which may trigger other rules and so on. If you create a good makefile, only the necessary rules (compiler/link commands) will run, which stands "to next" from the modified file in the dependency path.

Pick an example Makefile, read the manual for syntax (anyway, it's clear for first sight, w/o manual), and draw the graph. You have to understand compiler options in order to find out the names of the result files.

The make graph should be as complex just as you want. You can even do infinite loops (don't do)! You can tell make, which rule is your target, so only the left-standing files will be used as triggers.

Again: draw the graph!.

What is the difference between .NET Core and .NET Standard Class Library project types?

When should we use one over the other?

The decision is a trade-off between compatibility and API access.

Use a .NET Standard library when you want to increase the number of applications that will be compatible with your library, and you are okay with a decrease in the .NET API surface area your library can access.

Use a .NET Core library when you want to increase the .NET API surface area your library can access, and you are okay with allowing only .NET Core applications to be compatible with your library.

For example, a library that targets .NET Standard 1.3 will be compatible with applications that target .NET Framework 4.6, .NET Core 1.0, Universal Windows Platform 10.0, and any other platform that supports .NET Standard 1.3. The library will not have access to some parts of the .NET API, though. For instance, the Microsoft.NETCore.CoreCLR package is compatible with .NET Core, but not with .NET Standard.

What is the difference between Class Library (.NET Standard) and Class Library (.NET Core)?

Compatibility: Libraries that target .NET Standard will run on any .NET Standard compliant runtime, such as .NET Core, .NET Framework, Mono/Xamarin. On the other hand, libraries that target .NET Core can only run on the .NET Core runtime.

API Surface Area: .NET Standard libraries come with everything in NETStandard.Library, whereas .NET Core libraries come with everything in Microsoft.NETCore.App. The latter includes approximately 20 additional libraries, some of which we can add manually to our .NET Standard library (such as System.Threading.Thread) and some of which are not compatible with the .NET Standard (such as Microsoft.NETCore.CoreCLR).

Also, .NET Core libraries specify a runtime and come with an application model. That's important, for instance, to make unit test class libraries runnable.

Why do both exist?

Ignoring libraries for a moment, the reason that .NET Standard exists is for portability; it defines a set of APIs that .NET platforms agree to implement. Any platform that implements a .NET Standard is compatible with libraries that target that .NET Standard. One of those compatible platforms is .NET Core.

Coming back to libraries, the .NET Standard library templates exist to run on multiple runtimes (at the expense of API surface area). Conversely, the .NET Core library templates exist to access more API surface area (at the expense of compatibility) and to specify a platform against which to build an executable.

Here is an interactive matrix that shows which .NET Standard supports which .NET implementation(s) and how much API surface area is available.

CSS float right not working correctly

Verry Easy, change order of element:

Origin

<div style="">

    My Text

    <button type="button" style="float: right; margin:5px;">
       My Button
    </button>

</div>

Change to:

<div style=""> 

    <button type="button" style="float: right; margin:5px;">
       My Button
     </button>

   My Text

</div>

line breaks in a textarea

Ahh, it is really simple

just add

white-space:pre-wrap;

to your displaying element css

I mean if you are showing result using <p> then your css should be

p{
   white-space:pre-wrap;
}

Converting a String to DateTime

Different cultures in the world write date strings in different ways. For example, in the US 01/20/2008 is January 20th, 2008. In France this will throw an InvalidFormatException. This is because France reads date-times as Day/Month/Year, and in the US it is Month/Day/Year.

Consequently, a string like 20/01/2008 will parse to January 20th, 2008 in France, and then throw an InvalidFormatException in the US.

To determine your current culture settings, you can use System.Globalization.CultureInfo.CurrentCulture.

string dateTime = "01/08/2008 14:50:50.42";  
        DateTime dt = Convert.ToDateTime(dateTime);  
        Console.WriteLine("Year: {0}, Month: {1}, Day: {2}, Hour: {3}, Minute: {4}, Second: {5}, Millisecond: {6}",  
                          dt.Year, dt.Month, dt.Day, dt.Hour, dt.Minute, dt.Second, dt.Millisecond);

Submit form and stay on same page?

99% of the time I would use XMLHttpRequest or fetch for something like this. However, there's an alternative solution which doesn't require javascript...

You could include a hidden iframe on your page and set the target attribute of your form to point to that iframe.

<style>
  .hide { position:absolute; top:-1px; left:-1px; width:1px; height:1px; }
</style>

<iframe name="hiddenFrame" class="hide"></iframe>

<form action="receiver.pl" method="post" target="hiddenFrame">
  <input name="signed" type="checkbox">
  <input value="Save" type="submit">
</form>

There are very few scenarios where I would choose this route. Generally handling it with javascript is better because, with javascript you can...

gracefully handle errors (e.g. retry)
provide UI indicators (e.g. loading, processing, success, failure)
run logic before the request is sent, or run logic after the response is received.

When to use React setState callback

Yes there is, since setState works in an asynchronous way. That means after calling setState the this.state variable is not immediately changed. so if you want to perform an action immediately after setting state on a state variable and then return a result, a callback will be useful

Consider the example below

....
changeTitle: function changeTitle (event) {
  this.setState({ title: event.target.value });
  this.validateTitle();
},
validateTitle: function validateTitle () {
  if (this.state.title.length === 0) {
    this.setState({ titleError: "Title can't be blank" });
  }
},
....

The above code may not work as expected since the title variable may not have mutated before validation is performed on it. Now you may wonder that we can perform the validation in the render() function itself but it would be better and a cleaner way if we can handle this in the changeTitle function itself since that would make your code more organised and understandable

In this case callback is useful

....
changeTitle: function changeTitle (event) {
  this.setState({ title: event.target.value }, function() {
    this.validateTitle();
  });

},
validateTitle: function validateTitle () {
  if (this.state.title.length === 0) {
    this.setState({ titleError: "Title can't be blank" });
  }
},
....

Another example will be when you want to dispatch and action when the state changed. you will want to do it in a callback and not the render() as it will be called everytime rerendering occurs and hence many such scenarios are possible where you will need callback.

Another case is a API Call

A case may arise when you need to make an API call based on a particular state change, if you do that in the render method, it will be called on every render onState change or because some Prop passed down to the Child Component changed.

In this case you would want to use a setState callback to pass the updated state value to the API call

....
changeTitle: function (event) {
  this.setState({ title: event.target.value }, () => this.APICallFunction());
},
APICallFunction: function () {
  // Call API with the updated value
}
....

How to set a Postgresql default value datestamp like 'YYYYMM'?

Thanks for everyone who answered, and thanks for those who gave me the function-format idea, i'll really study it for future using.

But for this explicit case, the 'special yyyymm field' is not to be considered as a date field, but just as a tag, o whatever would be used for matching the exactly year-month researched value; there is already another date field, with the full timestamp, but if i need all the rows of january 2008, i think that is faster a select like

SELECT  [columns] FROM table WHERE yearmonth = '200801'

instead of

SELECT  [columns] FROM table WHERE date BETWEEN DATE('2008-01-01') AND DATE('2008-01-31')

How can I make a list of lists in R?

Using your example::

list1 <- list()
list1[1] = 1
list1[2] = 2
list2 <- list()
list2[1] = 'a'
list2[2] = 'b'
list_all <- list(list1, list2)

Use '[[' to retrieve an element of a list:

b = list_all[[1]]
 b
[[1]]
[1] 1

[[2]]
[1] 2

class(b)
[1] "list"

Linux configure/make, --prefix?

In my situation, --prefix= failed to update the path correctly under some warnings or failures. please see the below link for the answer. https://stackoverflow.com/a/50208379/1283198

How to respond to clicks on a checkbox in an AngularJS directive?

I prefer to use the ngModel and ngChange directives when dealing with checkboxes. ngModel allows you to bind the checked/unchecked state of the checkbox to a property on the entity:

<input type="checkbox" ng-model="entity.isChecked">

Whenever the user checks or unchecks the checkbox the entity.isChecked value will change too.

If this is all you need then you don't even need the ngClick or ngChange directives. Since you have the "Check All" checkbox, you obviously need to do more than just set the value of the property when someone checks a checkbox.

When using ngModel with a checkbox, it's best to use ngChange rather than ngClick for handling checked and unchecked events. ngChange is made for just this kind of scenario. It makes use of the ngModelController for data-binding (it adds a listener to the ngModelController's $viewChangeListeners array. The listeners in this array get called after the model value has been set, avoiding this problem).

<input type="checkbox" ng-model="entity.isChecked" ng-change="selectEntity()">

... and in the controller ...

var model = {};
$scope.model = model;

// This property is bound to the checkbox in the table header
model.allItemsSelected = false;

// Fired when an entity in the table is checked
$scope.selectEntity = function () {
    // If any entity is not checked, then uncheck the "allItemsSelected" checkbox
    for (var i = 0; i < model.entities.length; i++) {
        if (!model.entities[i].isChecked) {
            model.allItemsSelected = false;
            return;
        }
    }

    // ... otherwise ensure that the "allItemsSelected" checkbox is checked
    model.allItemsSelected = true;
};

Similarly, the "Check All" checkbox in the header:

<th>
    <input type="checkbox" ng-model="model.allItemsSelected" ng-change="selectAll()">
</th>

... and ...

// Fired when the checkbox in the table header is checked
$scope.selectAll = function () {
    // Loop through all the entities and set their isChecked property
    for (var i = 0; i < model.entities.length; i++) {
        model.entities[i].isChecked = model.allItemsSelected;
    }
};

CSS

What is the best way to... add a CSS class to the <tr> containing the entity to reflect its selected state?

If you use the ngModel approach for the data-binding, all you need to do is add the ngClass directive to the <tr> element to dynamically add or remove the class whenever the entity property changes:

<tr ng-repeat="entity in model.entities" ng-class="{selected: entity.isChecked}">

See the full Plunker here.

Split a string by another string in C#

The previous answers are all correct. I go one step further and make C# work for me by defining an extension method on String:

public static class Extensions
{
    public static string[] Split(this string toSplit, string splitOn) {
        return toSplit.Split(new string[] { splitOn }, StringSplitOptions.None);
    }
}

That way I can call it on any string in the simple way I naively expected the first time I tried to accomplish this:

"a big long string with stuff to split on".Split("g str");

append multiple values for one key in a dictionary

d = {} 

# import list of year,value pairs

for year,value in mylist:
    try:
        d[year].append(value)
    except KeyError:
        d[year] = [value]

The Python way - it is easier to receive forgiveness than ask permission!

Show image using file_get_contents

Do i need to modify the headers and just echo it or something?

exactly.

Send a header("content-type: image/your_image_type"); and the data afterwards.

Show all current locks from get_lock

Another easy way is to use:

mysqladmin debug

This dumps a lot of information (including locks) to the error log.

Python, HTTPS GET with basic authentication

Update: OP uses Python 3. So adding an example using httplib2

import httplib2

h = httplib2.Http(".cache")

h.add_credentials('name', 'password') # Basic authentication

resp, content = h.request("https://host/path/to/resource", "POST", body="foobar")

The below works for python 2.6:

I use pycurl a lot in production for a process which does upwards of 10 million requests per day.

You'll need to import the following first.

import pycurl
import cStringIO
import base64

Part of the basic authentication header consists of the username and password encoded as Base64.

headers = { 'Authorization' : 'Basic %s' % base64.b64encode("username:password") }

In the HTTP header you will see this line Authorization: Basic dXNlcm5hbWU6cGFzc3dvcmQ=. The encoded string changes depending on your username and password.

We now need a place to write our HTTP response to and a curl connection handle.

response = cStringIO.StringIO()
conn = pycurl.Curl()

We can set various curl options. For a complete list of options, see this. The linked documentation is for the libcurl API, but the options does not change for other language bindings.

conn.setopt(pycurl.VERBOSE, 1)
conn.setopt(pycurlHTTPHEADER, ["%s: %s" % t for t in headers.items()])

conn.setopt(pycurl.URL, "https://host/path/to/resource")
conn.setopt(pycurl.POST, 1)

If you do not need to verify certificate. Warning: This is insecure. Similar to running curl -k or curl --insecure.

conn.setopt(pycurl.SSL_VERIFYPEER, False)
conn.setopt(pycurl.SSL_VERIFYHOST, False)

Call cStringIO.write for storing the HTTP response.

conn.setopt(pycurl.WRITEFUNCTION, response.write)

When you're making a POST request.

post_body = "foobar"
conn.setopt(pycurl.POSTFIELDS, post_body)

Make the actual request now.

conn.perform()

Do something based on the HTTP response code.

http_code = conn.getinfo(pycurl.HTTP_CODE)
if http_code is 200:
   print response.getvalue()

CS0120: An object reference is required for the nonstatic field, method, or property 'foo'

It looks like you are calling a non static member (a property or method, specifically setTextboxText) from a static method (specifically SumData). You will need to either:

Make the called member static also:

static void setTextboxText(int result)
{
    // Write static logic for setTextboxText.  
    // This may require a static singleton instance of Form1.
}

Create an instance of Form1 within the calling method:

private static void SumData(object state)
{
    int result = 0;
    //int[] icount = (int[])state;
    int icount = (int)state;

    for (int i = icount; i > 0; i--)
    {
        result += i;
        System.Threading.Thread.Sleep(1000);
    }
    Form1 frm1 = new Form1();
    frm1.setTextboxText(result);
}

Passing in an instance of Form1 would be an option also.

Make the calling method a non-static instance method (of Form1):

private void SumData(object state)
{
    int result = 0;
    //int[] icount = (int[])state;
    int icount = (int)state;

    for (int i = icount; i > 0; i--)
    {
        result += i;
        System.Threading.Thread.Sleep(1000);
    }
    setTextboxText(result);
}

More info about this error can be found on MSDN.

Looping over elements in jQuery

I have used the following before:

var my_form = $('#form-id');
var data = {};

$('input:not([type=checkbox]), input[type=checkbox]:selected, select, textarea', my_form).each(
    function() {
        var name = $(this).attr('name');
        var val = $(this).val();

        if (!data.hasOwnProperty(name)) {
            data[name] = new Array;
        }

        data[name].push(val);
    }
);

This is just written from memory, so might contain mistakes, but this should make an object called data that contains the values for all your inputs.

Note that you have to deal with checkboxes in a special way, to avoid getting the values of unchecked checkboxes. The same is probably true of radio inputs.

Also note using arrays for storing the values, as for one input name, you might have values from several inputs (checkboxes in particular).

XPath: Get parent node from child node

Just as an alternative, you can use ancestor.

//*[title="50"]/ancestor::store

It's more powerful than parent since it can get even the grandparent or great great grandparent

How do I view the Explain Plan in Oracle Sql developer?

EXPLAIN PLAN FOR

In SQL Developer, you don't have to use EXPLAIN PLAN FOR statement. Press F10 or click the Explain Plan icon.

enter image description here

It will be then displayed in the Explain Plan window.

If you are using SQL*Plus then use DBMS_XPLAN.

For example,

SQL> EXPLAIN PLAN FOR
  2  SELECT * FROM DUAL;

Explained.

SQL> SELECT * FROM TABLE(DBMS_XPLAN.DISPLAY);

PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------
Plan hash value: 272002086

--------------------------------------------------------------------------
| Id  | Operation         | Name | Rows  | Bytes | Cost (%CPU)| Time     |
--------------------------------------------------------------------------
|   0 | SELECT STATEMENT  |      |     1 |     2 |     2   (0)| 00:00:01 |
|   1 |  TABLE ACCESS FULL| DUAL |     1 |     2 |     2   (0)| 00:00:01 |
--------------------------------------------------------------------------

8 rows selected.

SQL>

See How to create and display Explain Plan

Why does DEBUG=False setting make my django Static Files Access fail?

I did the following changes to my project/urls.py and it worked for me

Add this line : from django.conf.urls import url

and add : url(r'^media/(?P.*)$', serve, {'document_root': settings.MEDIA_ROOT, }), in urlpatterns.

MVC3 DropDownListFor - a simple example?

I think this will help : In Controller get the list items and selected value

public ActionResult Edit(int id)
{
    ItemsStore item = itemStoreRepository.FindById(id);
    ViewBag.CategoryId = new SelectList(categoryRepository.Query().Get(), 
                                        "Id", "Name",item.CategoryId);

    // ViewBag to pass values to View and SelectList
    //(get list of items,valuefield,textfield,selectedValue)

    return View(item);
}

and in View

@Html.DropDownList("CategoryId",String.Empty)

Upgrade python in a virtualenv

I moved my home directory from one mac to another (Mountain Lion to Yosemite) and didn't realize about the broken virtualenv until I lost hold of the old laptop. I had the virtualenv point to Python 2.7 installed by brew and since Yosemite came with Python 2.7, I wanted to update my virtualenv to the system python. When I ran virtualenv on top of the existing directory, I was getting OSError: [Errno 17] File exists: '/Users/hdara/bin/python2.7/lib/python2.7/config' error. By trial and error, I worked around this issue by removing a few links and fixing up a few more manually. This is what I finally did (similar to what @Rockalite did, but simpler):

cd <virtualenv-root>
rm lib/python2.7/config
rm lib/python2.7/lib-dynload
rm include/python2.7
rm .Python
cd lib/python2.7
gfind . -type l -xtype l | while read f; do ln -s -f /System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/${f#./} $f; done

After this, I was able to just run virtualenv on top of the existing directory.

How to create a new schema/new user in Oracle Database 11g?

It's a working example:

CREATE USER auto_exchange IDENTIFIED BY 123456;
GRANT RESOURCE TO auto_exchange;
GRANT CONNECT TO auto_exchange;
GRANT CREATE VIEW TO auto_exchange;
GRANT CREATE SESSION TO auto_exchange;
GRANT UNLIMITED TABLESPACE TO auto_exchange;

input type="submit" Vs button tag are they interchangeable?

http://www.w3.org/TR/html4/interact/forms.html#h-17.5

Buttons created with the BUTTON element function just like buttons created with the INPUT element, but they offer richer rendering possibilities: the BUTTON element may have content. For example, a BUTTON element that contains an image functions like and may resemble an INPUT element whose type is set to "image", but the BUTTON element type allows content.

So for functionality only they're interchangeable!

(Don't forget, type="submit" is the default with button, so leave it off!)

Java String split removed empty values

String[] split = data.split("\\|",-1);

This is not the actual requirement in all the time. The Drawback of above is show below:

Scenerio 1:
When all data are present:
    String data = "5|6|7||8|9|10|";
    String[] split = data.split("\\|");
    String[] splt = data.split("\\|",-1);
    System.out.println(split.length); //output: 7
    System.out.println(splt.length); //output: 8

When data is missing:

Scenerio 2: Data Missing
    String data = "5|6|7||8|||";
    String[] split = data.split("\\|");
    String[] splt = data.split("\\|",-1);
    System.out.println(split.length); //output: 5
    System.out.println(splt.length); //output: 8

Real requirement is length should be 7 although there is data missing. Because there are cases such as when I need to insert in database or something else. We can achieve this by using below approach.

    String data = "5|6|7||8|||";
    String[] split = data.split("\\|");
    String[] splt = data.replaceAll("\\|$","").split("\\|",-1);
    System.out.println(split.length); //output: 5
    System.out.println(splt.length); //output:7

What I've done here is, I'm removing "|" pipe at the end and then splitting the String. If you have "," as a seperator then you need to add ",$" inside replaceAll.

Found 'OR 1=1/* sql injection in my newsletter database

The specific value in your database isn't what you should be focusing on. This is likely the result of an attacker fuzzing your system to see if it is vulnerable to a set of standard attacks, instead of a targeted attack exploiting a known vulnerability.

You should instead focus on ensuring that your application is secure against these types of attacks; OWASP is a good resource for this.

If you're using parameterized queries to access the database, then you're secure against Sql injection, unless you're using dynamic Sql in the backend as well.

If you're not doing this, you're vulnerable and you should resolve this immediately.

Also, you should consider performing some sort of validation of e-mail addresses.

How can I be notified when an element is added to the page?

Check out this plugin that does exacly that - jquery.initialize

It works exacly like .each function, the difference is it takes selector you've entered and watch for new items added in future matching this selector and initialize them

Initialize looks like this

$(".some-element").initialize( function(){
    $(this).css("color", "blue");
});

But now if new element matching .some-element selector will appear on page, it will be instanty initialized.

The way new item is added is not important, you dont need to care about any callbacks etc.

So if you'd add new element like:

$("<div/>").addClass('some-element').appendTo("body"); //new element will have blue color!

it will be instantly initialized.

Plugin is based on MutationObserver

map vs. hash_map in C++

I don't know what gives, but, hash_map takes more than 20 seconds to clear() 150K unsigned integer keys and float values. I am just running and reading someone else's code.

This is how it includes hash_map.

#include "StdAfx.h"
#include <hash_map>

I read this here https://bytes.com/topic/c/answers/570079-perfomance-clear-vs-swap

saying that clear() is order of O(N). That to me, is very strange, but, that's the way it is.

Should I use Python 32bit or Python 64bit

64 bit version will allow a single process to use more RAM than 32 bit, however you may find that the memory footprint doubles depending on what you are storing in RAM (Integers in particular).

For example if your app requires > 2GB of RAM, so you switch from 32bit to 64bit you may find that your app is now requiring > 4GB of RAM.

Check whether all of your 3rd party modules are available in 64 bit, otherwise it may be easier to stick to 32bit in the meantime

SQL Server: Query fast, but slow from procedure

This is probably unlikely, but given that your observed behaviour is unusual it needs to be checked and no-one else has mentioned it.

Are you absolutely sure that all objects are owned by dbo and you don't have a rogue copies owned by yourself or a different user present as well?

Just occasionally when I've seen odd behaviour it's because there was actually two copies of an object and which one you get depends on what is specified and who you are logged on as. For example it is perfectly possible to have two copies of a view or procedure with the same name but owned by different owners - a situation that can arise where you are not logged onto the database as a dbo and forget to specify dbo as object owner when you create the object.

In note that in the text you are running some things without specifying owner, eg

sp_recompile ViewOpener

if for example there where two copies of viewOpener present owned by dbo and [some other user] then which one you actually recompile if you don't specify is dependent upon circumstances. Ditto with the Report_Opener view - if there where two copies (and they could differ in specification or execution plan) then what is used depends upon circumstances - and as you do not specify owner it is perfectly possible that your adhoc query might use one and the compiled procedure might use use the other.

As I say, it's probably unlikely but it is possible and should be checked because your issues could be that you're simply looking for the bug in the wrong place.

How to add shortcut keys for java code in eclipse

Type syso and ctrl + space for System.out.println()

how to get the first and last days of a given month

I know this question has a good answer with 't', but thought I would add another solution.

$first = date("Y-m-d", strtotime("first day of this month"));
$last = date("Y-m-d", strtotime("last day of this month"));

Spring JUnit: How to Mock autowired component in autowired component

You can override bean definitions with mocks with spring-reinject https://github.com/sgri/spring-reinject/

how to clear localstorage,sessionStorage and cookies in javascript? and then retrieve?

how to completely clear localstorage

localStorage.clear();

how to completely clear sessionstorage

sessionStorage.clear();

[...] Cookies ?

var cookies = document.cookie;

for (var i = 0; i < cookies.split(";").length; ++i)
{
    var myCookie = cookies[i];
    var pos = myCookie.indexOf("=");
    var name = pos > -1 ? myCookie.substr(0, pos) : myCookie;
    document.cookie = name + "=;expires=Thu, 01 Jan 1970 00:00:00 GMT";
}

is there any way to get the value back after clear these ?

No, there isn't. But you shouldn't rely on this if this is related to a security question.

Docker error : no space left on device

I had the same error and solve it this way:

1 . Delete the orphaned volumes in Docker, you can use the built-in docker volume command. The built-in command also deletes any directory in /var/lib/docker/volumes that is not a volume so make sure you didn't put anything in there you want to save.

Warning be very careful with this if you have some data you want to keep

Cleanup:

$ docker volume rm $(docker volume ls -qf dangling=true)

Additional commands:

List dangling volumes:

$ docker volume ls -qf dangling=true

List all volumes:

$ docker volume ls

2 . Also consider removing all the unused Images.

First get rid of the <none> images (those are sometimes generated while building an image and if for any reason the image building was interrupted, they stay there).

here's a nice script I use to remove them

docker rmi $(docker images | grep '^<none>' | awk '{print $3}')

Then if you are using Docker Compose to build Images locally for every project. You will end up with a lot of images usually named like your folder (example if your project folder named Hello, you will find images name Hello_blablabla). so also consider removing all these images

you can edit the above script to remove them or remove them manually with

docker rmi {image-name}

C#: List All Classes in Assembly

Use Assembly.GetTypes. For example:

Assembly mscorlib = typeof(string).Assembly;
foreach (Type type in mscorlib.GetTypes())
{
    Console.WriteLine(type.FullName);
}

Cannot find reference 'xxx' in init.py - Python / Pycharm

You should first take a look at this. This explains what happens when you import a package. For convenience:

The import statement uses the following convention: if a package’s __init__.py code defines a list named __all__, it is taken to be the list of module names that should be imported when from package import * is encountered. It is up to the package author to keep this list up-to-date when a new version of the package is released. Package authors may also decide not to support it, if they don’t see a use for importing * from their package.

So PyCharm respects this by showing a warning message, so that the author can decide which of the modules get imported when * from the package is imported. Thus this seems to be useful feature of PyCharm (and in no way can it be called a bug, I presume). You can easily remove this warning by adding the names of the modules to be imported when your package is imported in the __all__ variable which is list, like this

__init__.py

from . import MyModule1, MyModule2, MyModule3
__all__ = [MyModule1, MyModule2, MyModule3]

After you add this, you can ctrl+click on these module names used in any other part of your project to directly jump to the declaration, which I often find very useful.

Is there a developers api for craigslist.org

The closest I have been able to find is called 3taps. 3taps was sued by Craigslist with the result that "access to public data on a public website can be selectively censored by blacklisting certain viewers (i.e. competitors)", and thus states that "3taps will therefore access the very same data exclusively from public sources that retain open and equal access rights to public data".

C# - Winforms - Global Variables

They have already answered how to use a global variable.

I will tell you why the use of global variables is a bad idea as a result of this question carried out in stackoverflow in Spanish.

Explicit translation of the text in Spanish:

Impact of the change

The problem with global variables is that they create hidden dependencies. When it comes to large applications, you yourself do not know / remember / you are clear about the objects you have and their relationships.

So, you can not have a clear notion of how many objects your global variable is using. And if you want to change something of the global variable, for example, the meaning of each of its possible values, or its type? How many classes or compilation units will that change affect? If the amount is small, it may be worth making the change. If the impact will be great, it may be worth looking for another solution.

But what is the impact? Because a global variable can be used anywhere in the code, it can be very difficult to measure it.

In addition, always try to have a variable with the shortest possible life time, so that the amount of code that makes use of that variable is the minimum possible, and thus better understand its purpose, and who modifies it.

A global variable lasts for the duration of the program, and therefore, anyone can use the variable, either to read it, or even worse, to change its value, making it more difficult to know what value the variable will have at any given program point. .

Order of destruction

Another problem is the order of destruction. Variables are always destroyed in reverse order of their creation, whether they are local or global / static variables (an exception is the primitive types, int,enums, etc., which are never destroyed if they are global / static until they end the program).

The problem is that it is difficult to know the order of construction of the global (or static) variables. In principle, it is indeterminate.

If all your global / static variables are in a single compilation unit (that is, you only have a .cpp), then the order of construction is the same as the writing one (that is, variables defined before, are built before).

But if you have more than one .cpp each with its own global / static variables, the global construction order is indeterminate. Of course, the order in each compilation unit (each .cpp) in particular, is respected: if the global variableA is defined before B,A will be built before B, but It is possible that between A andB variables of other .cpp are initialized. For example, if you have three units with the following global / static variables:

Image1

In the executable it could be created in this order (or in any other order as long as the relative order is respected within each .cpp):

Image2

Why is this important? Because if there are relations between different static global objects, for example, that some use others in their destructors, perhaps, in the destructor of a global variable, you use another global object from another compilation unit that turns out to be already destroyed ( have been built later).

Hidden dependencies and * test cases *

I tried to find the source that I will use in this example, but I can not find it (anyway, it was to exemplify the use of singletons, although the example is applicable to global and static variables). Hidden dependencies also create new problems related to controlling the behavior of an object, if it depends on the state of a global variable.

Imagine you have a payment system, and you want to test it to see how it works, since you need to make changes, and the code is from another person (or yours, but from a few years ago). You open a new main, and you call the corresponding function of your global object that provides a bank payment service with a card, and it turns out that you enter your data and they charge you. How, in a simple test, have I used a production version? How can I do a simple payment test?

After asking other co-workers, it turns out that you have to "mark true", a global bool that indicates whether we are in test mode or not, before beginning the collection process. Your object that provides the payment service depends on another object that provides the mode of payment, and that dependency occurs in an invisible way for the programmer.

In other words, the global variables (or singletones), make it impossible to pass to "test mode", since global variables can not be replaced by "testing" instances (unless you modify the code where said code is created or defined). global variable, but we assume that the tests are done without modifying the mother code).

Solution

This is solved by means of what is called * dependency injection *, which consists in passing as a parameter all the dependencies that an object needs in its constructor or in the corresponding method. In this way, the programmer ** sees ** what has to happen to him, since he has to write it in code, making the developers gain a lot of time.

If there are too many global objects, and there are too many parameters in the functions that need them, you can always group your "global objects" into a class, style * factory *, that builds and returns the instance of the "global object" (simulated) that you want , passing the factory as a parameter to the objects that need the global object as dependence.

If you pass to test mode, you can always create a testing factory (which returns different versions of the same objects), and pass it as a parameter without having to modify the target class.

But is it always bad?

Not necessarily, there may be good uses for global variables. For example, constant values ??(the PI value). Being a constant value, there is no risk of not knowing its value at a given point in the program by any type of modification from another module. In addition, constant values ??tend to be primitive and are unlikely to change their definition.

It is more convenient, in this case, to use global variables to avoid having to pass the variables as parameters, simplifying the signatures of the functions.

Another can be non-intrusive "global" services, such as a logging class (saving what happens in a file, which is usually optional and configurable in a program, and therefore does not affect the application's nuclear behavior), or std :: cout,std :: cin or std :: cerr, which are also global objects.

Any other thing, even if its life time coincides almost with that of the program, always pass it as a parameter. Even the variable could be global in a module, only in it without any other having access, but that, in any case, the dependencies are always present as parameters.

Answer by: Peregring-lk

Building and running app via Gradle and Android Studio is slower than via Eclipse

Solved mine with

File -> Settings -> Build, Execution, Deployment -> Build Tools -> Gradle -> Offline work

Gradle builds went from 8 minutes to 3 seconds.

How to automatically generate getters and setters in Android Studio

Android Studio & Windows :

fn + alt + insert

How do I set up access control in SVN?

You can use svn+ssh:, and then it's based on access control to the repository at the given location.

This is how I host a project group repository at my uni, where I can't set up anything else. Just having a directory that the group owns, and running svn-admin (or whatever it was) in there means that I didn't need to do any configuration.

Data truncated for column?

I had the same problem, with a database field with type "SET" which is an enum type.

I tried to add a value which was not in that list.

The value I tried to add had the decimal value 256, but the enum list only had 8 values.

1: 1   -> A
2: 2   -> B
3: 4   -> C
4: 8   -> D
5: 16  -> E
6: 32  -> F
7: 64  -> G
8: 128 -> H

So I just had to add the additional value to the field.

Reading this documentation entry helped me to understand the problem.

MySQL stores SET values numerically, with the low-order bit of the stored value corresponding to the first set member. If you retrieve a SET value in a numeric context, the value retrieved has bits set corresponding to the set members that make up the column value. For example, you can retrieve numeric values from a SET column like this:
mysql> SELECT set_col+0 FROM tbl_name; If a number is stored into a
If a number is stored into a SET column, the bits that are set in the binary representation of the number determine the set members in the column value. For a column specified as SET('a','b','c','d'), the members have the following decimal and binary values.

SET Member  Decimal Value   Binary Value
    'a'                1          0001
    'b'                2          0010
    'c'                4          0100
    'd'                8          1000

If you assign a value of 9 to this column, that is 1001 in binary, so the first and fourth SET value members 'a' and 'd' are selected and the resulting value is 'a,d'.

MySql with JAVA error. The last packet sent successfully to the server was 0 milliseconds ago

THis issue has been fixed with new mysql connectors, please use http://mvnrepository.com/artifact/mysql/mysql-connector-java/5.1.38

I used to get this error after updating the connector jar, issue resolved.

How to merge two PDF files into one in Java?

package article14;

import java.io.File;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.util.PDFMergerUtility;

public class Pdf
{
    public static void main(String args[])
    {
        new Pdf().createNew();
        new Pdf().combine();
        }

    public void combine()
    {
        try
        {
        PDFMergerUtility mergePdf = new PDFMergerUtility();
        String folder ="pdf";
        File _folder = new File(folder);
        File[] filesInFolder;
        filesInFolder = _folder.listFiles();
        for (File string : filesInFolder)
        {
            mergePdf.addSource(string);    
        }
    mergePdf.setDestinationFileName("Combined.pdf");
    mergePdf.mergeDocuments();
        }
        catch(Exception e)
        {

        }  
    }

public void createNew()
{
    PDDocument document = null;
    try
    {
        String filename="test.pdf";
        document=new PDDocument();
        PDPage blankPage = new PDPage();
        document.addPage( blankPage );
        document.save( filename );
    }
    catch(Exception e)
    {

    }
}

}

Regular Expression Match to test for a valid year

/^\d{4}$/ This will check if a string consists of only 4 numbers. In this scenario, to input a year 989, you can give 0989 instead.

Cannot redeclare function php

You (or Joomla) is likely including this file multiple times. Enclose your function in a conditional block:

if (!function_exists('parseDate')) {
    // ... proceed to declare your function
}

Remove first 4 characters of a string with PHP

If you’re using a multi-byte character encoding and do not just want to remove the first four bytes like substr does, use the multi-byte counterpart mb_substr. This does of course will also work with single-byte strings.

How to put Google Maps V2 on a Fragment using ViewPager

You can use this line if you want to use GoogleMap in a fragment:

<fragment
            android:id="@+id/map"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            class="com.google.android.gms.maps.SupportMapFragment" />

GoogleMap mGoogleMap = ((SupportMapFragment) getChildFragmentManager().findFragmentById(R.id.map)).getMap();

port 8080 is already in use and no process using 8080 has been listed

In windows " wmic process where processid="pid of the process running" get commandline " worked for me. The culprit was wrapper.exe process of webhuddle jboss soft.

How to get Activity's content view?

You can also override onContentChanged() which is among others fired when setContentView() has been called.

How do I find the parent directory in C#?

Directory.GetParent is probably a better answer, but for completeness there's a different method that takes string and returns string: Path.GetDirectoryName.

string parent = System.IO.Path.GetDirectoryName(str_directory);

Changing java platform on which netbeans runs

In my Windows 7 box I found netbeans.conf in <Drive>:\<Program Files folder>\<NetBeans installation folder>\etc . Thanks all.

Bitwise operation and usage

the following bitwise operators: &, |, ^, and ~ return values (based on their input) in the same way logic gates affect signals. You could use them to emulate circuits.

Kendo grid date column not formatting

As far as I'm aware in order to format a date value you have to handle it in parameterMap,

$('#listDiv').kendoGrid({
            dataSource: {
                type: 'json',
                serverPaging: true,
                pageSize: 10,
                transport: {
                    read: {
                        url: '@Url.Action("_ListMy", "Placement")',
                        data: refreshGridParams,
                        type: 'POST'
                    },
                    parameterMap: function (options, operation) {
                        if (operation != "read") {
                            var d = new Date(options.StartDate);
                            options.StartDate = kendo.toString(new Date(d), "dd/MM/yyyy");
                            return options;
                        }
                        else { return options; }

                    }
                },
                schema: {
                    model: {
                        id: 'Id',
                        fields: {
                            Id: { type: 'number' },
                            StartDate: { type: 'date', format: 'dd/MM/yyyy' },
                            Area: { type: 'string' },
                            Length: { type: 'string' },
                            Display: { type: 'string' },
                            Status: { type: 'string' },
                            Edit: { type: 'string' }
                        }
                    },
                    data: "Data",
                    total: "Count"
                }
            },
            scrollable: false,
            columns:
                [
                    {
                        field: 'StartDate',
                        title: 'Start Date',
                        format: '{0:dd/MM/yyyy}',
                        width: 100
                    },

If you follow the above example and just renames objects like 'StartDate' then it should work (ignore 'data: refreshGridParams,')

For further details check out below link or just search for kendo grid parameterMap ans see what others have done.

http://docs.kendoui.com/api/framework/datasource#configuration-transport.parameterMap

Get random integer in range (x, y]?

How about:

Random generator = new Random();
int i = 10 - generator.nextInt(10);

SQL Developer with JDK (64 bit) cannot find JVM

Create directory bin in

D:\sqldeveloper\jdk\

Copy

msvcr100.dll

from

D:\sqldeveloper\jdk\jre\bin

D:\sqldeveloper\jdk\bin

How to destroy a JavaScript object?

While the existing answers have given solutions to solve the issue and the second half of the question, they do not provide an answer to the self discovery aspect of the first half of the question that is in bold:

"How can I see which variable causes memory overhead...?"

It may not have been as robust 3 years ago, but the Chrome Developer Tools "Profiles" section is now quite powerful and feature rich. The Chrome team has an insightful article on using it and thus also how garbage collection (GC) works in javascript, which is at the core of this question.

Since delete is basically the root of the currently accepted answer by Yochai Akoka, it's important to remember what delete does. It's irrelevant if not combined with the concepts of how GC works in the next two answers: if there's an existing reference to an object it's not cleaned up. The answers are more correct, but probably not as appreciated because they require more thought than just writing 'delete'. Yes, one possible solution may be to use delete, but it won't matter if there's another reference to the memory leak.

Another answer appropriately mentions circular references and the Chrome team documentation can provide much more clarity as well as the tools to verify the cause.

Since delete was mentioned here, it also may be useful to provide the resource Understanding Delete. Although it does not get into any of the actual solution which is really related to javascript's garbage collector.

How to format DateTime in Flutter , How to get current time in flutter?

You can use DateFormat from intl package.

import 'package:intl/intl.dart';

DateTime now = DateTime.now();
String formattedDate = DateFormat('yyyy-MM-dd – kk:mm').format(now);

Iterating over and deleting from Hashtable in Java

So you know the key, value pair that you want to delete in advance? It's just much clearer to do this, then:

 table.delete(key);
 for (K key: table.keySet()) {
    // do whatever you need to do with the rest of the keys
 }

Forward slash in Java Regex

The problem is actually that you need to double-escape backslashes in the replacement string. You see, "\\/" (as I'm sure you know) means the replacement string is \/, and (as you probably don't know) the replacement string \/ actually just inserts /, because Java is weird, and gives \ a special meaning in the replacement string. (It's supposedly so that \$ will be a literal dollar sign, but I think the real reason is that they wanted to mess with people. Other languages don't do it this way.) So you have to write either:

"Hello/You/There".replaceAll("/", "\\\\/");

or:

"Hello/You/There".replaceAll("/", Matcher.quoteReplacement("\\/"));

(Using java.util.regex.Matcher.quoteReplacement(String).)

Is it possible to install iOS 6 SDK on Xcode 5?

Yes, I just solved the problem today.

Find the SDK file, like iPhoneOS6.1.sdk, in your or your friend's older Xcode directory.
Copy & put it into the Xcode 5 directory : /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs.

enter image description here

Then you can choose the SDK like below :

enter image description here

Hope this helps you.

Spring mvc @PathVariable

Have a look at the below code snippet.

@RequestMapping(value="/Add/{type}")
public ModelAndView addForm(@PathVariable String type ){
    ModelAndView modelAndView = new ModelAndView();
    modelAndView.setViewName("addContent");
    modelAndView.addObject("typelist",contentPropertyDAO.getType() );
    modelAndView.addObject("property",contentPropertyDAO.get(type,0) );
    return modelAndView;
}

Hope it helps in constructing your code.

Check last modified date of file in C#

Be aware that the function File.GetLastWriteTime does not always work as expected, the values are sometimes not instantaneously updated by the OS. You may get an old Timestamp, even if the file has been modified right before.

The behaviour may vary between OS versions. For example, this unit test worked well every time on my developer machine, but it always fails on our build server.

  [TestMethod]
  public void TestLastModifiedTimeStamps()
  {
     var tempFile = Path.GetTempFileName();
     var lastModified = File.GetLastWriteTime(tempFile);
     using (new FileStream(tempFile, FileMode.Create, FileAccess.Write, FileShare.None))
     {

     }
     Assert.AreNotEqual(lastModified, File.GetLastWriteTime(tempFile));
  }

See File.GetLastWriteTime seems to be returning 'out of date' value

Your options:

a) live with the occasional omissions.

b) Build up an active component realising the observer pattern (eg. a tcp server client structure), communicating the changes directly instead of writing / reading files. Fast and flexible, but another dependency and a possible point of failure (and some work, of course).

c) Ensure the signalling process by replacing the content of a dedicated signal file that other processes regularly read. It´s not that smart as it´s a polling procedure and has a greater overhead than calling File.GetLastWriteTime, but if not checking the content from too many places too often, it will do the work.

/// <summary>
/// type to set signals or check for them using a central file 
/// </summary>
public class FileSignal
{
    /// <summary>
    /// path to the central file for signal control
    /// </summary>
    public string FilePath { get; private set; }

    /// <summary>
    /// numbers of retries when not able to retrieve (exclusive) file access
    /// </summary>
    public int MaxCollisions { get; private set; }

    /// <summary>
    /// timespan to wait until next try
    /// </summary>
    public TimeSpan SleepOnCollisionInterval { get; private set; }

    /// <summary>
    /// Timestamp of the last signal
    /// </summary>
    public DateTime LastSignal { get; private set; }

    /// <summary>
    /// constructor
    /// </summary>
    /// <param name="filePath">path to the central file for signal control</param>
    /// <param name="maxCollisions">numbers of retries when not able to retrieve (exclusive) file access</param>
    /// <param name="sleepOnCollisionInterval">timespan to wait until next try </param>
    public FileSignal(string filePath, int maxCollisions, TimeSpan sleepOnCollisionInterval)
    {
        FilePath = filePath;
        MaxCollisions = maxCollisions;
        SleepOnCollisionInterval = sleepOnCollisionInterval;
        LastSignal = GetSignalTimeStamp();
    }

    /// <summary>
    /// constructor using a default value of 50 ms for sleepOnCollisionInterval
    /// </summary>
    /// <param name="filePath">path to the central file for signal control</param>
    /// <param name="maxCollisions">numbers of retries when not able to retrieve (exclusive) file access</param>        
    public FileSignal(string filePath, int maxCollisions): this (filePath, maxCollisions, TimeSpan.FromMilliseconds(50))
    {
    }

    /// <summary>
    /// constructor using a default value of 50 ms for sleepOnCollisionInterval and a default value of 10 for maxCollisions
    /// </summary>
    /// <param name="filePath">path to the central file for signal control</param>        
    public FileSignal(string filePath) : this(filePath, 10)
    {
    }

    private Stream GetFileStream(FileAccess fileAccess)
    {
        var i = 0;
        while (true)
        {
            try
            {
                return new FileStream(FilePath, FileMode.Create, fileAccess, FileShare.None);
            }
            catch (Exception e)
            {
                i++;
                if (i >= MaxCollisions)
                {
                    throw e;
                }
                Thread.Sleep(SleepOnCollisionInterval);
            };
        };
    }

    private DateTime GetSignalTimeStamp()
    {
        if (!File.Exists(FilePath))
        {
            return DateTime.MinValue;
        }
        using (var stream = new FileStream(FilePath, FileMode.Open, FileAccess.Read, FileShare.None))
        {
            if(stream.Length == 0)
            {
                return DateTime.MinValue;
            }
            using (var reader = new BinaryReader(stream))
            {
                return DateTime.FromBinary(reader.ReadInt64());
            };                
        }
    }

    /// <summary>
    /// overwrites the existing central file and writes the current time into it.
    /// </summary>
    public void Signal()
    {
        LastSignal = DateTime.Now;
        using (var stream = new FileStream(FilePath, FileMode.Create, FileAccess.Write, FileShare.None))
        {
            using (var writer = new BinaryWriter(stream))
            {
                writer.Write(LastSignal.ToBinary());
            }
        }
    }

    /// <summary>
    /// returns true if the file signal has changed, otherwise false.
    /// </summary>        
    public bool CheckIfSignalled()
    {
        var signal = GetSignalTimeStamp();
        var signalTimestampChanged = LastSignal != signal;
        LastSignal = signal;
        return signalTimestampChanged;
    }
}

Some tests for it:

    [TestMethod]
    public void TestSignal()
    {
        var fileSignal = new FileSignal(Path.GetTempFileName());
        var fileSignal2 = new FileSignal(fileSignal.FilePath);
        Assert.IsFalse(fileSignal.CheckIfSignalled());
        Assert.IsFalse(fileSignal2.CheckIfSignalled());
        Assert.AreEqual(fileSignal.LastSignal, fileSignal2.LastSignal);
        fileSignal.Signal();
        Assert.IsFalse(fileSignal.CheckIfSignalled());
        Assert.AreNotEqual(fileSignal.LastSignal, fileSignal2.LastSignal);
        Assert.IsTrue(fileSignal2.CheckIfSignalled());
        Assert.AreEqual(fileSignal.LastSignal, fileSignal2.LastSignal);
        Assert.IsFalse(fileSignal2.CheckIfSignalled());
    }

HTML/Javascript: how to access JSON data loaded in a script tag with src set

I agree with Ben. You cannot load/import the simple JSON file.

But if you absolutely want to do that and have flexibility to update json file, you can

my-json.js

   var myJSON = {
      id: "12ws",
      name: "smith"
    }

index.html

<head>
  <script src="my-json.js"></script>
</head>
<body onload="document.getElementById('json-holder').innerHTML = JSON.stringify(myJSON);">
  <div id="json-holder"></div>
</body>

How to import XML file into MySQL database table using XML_LOAD(); function

Since ID is auto increment, you can also specify ID=NULL as,

LOAD XML LOCAL INFILE '/pathtofile/file.xml' INTO TABLE my_tablename SET ID=NULL;

How to get a unique computer identifier in Java (like disk ID or motherboard ID)?

In the java programs I have written for release I used the motherboard serial number (which is what I beleive windows use); however, this only works on windows as my function creates a temporary VB script which uses the WMI to retrieve the value.

public static String getMotherboardSerial() {
      String result = "";
        try {
          File file = File.createTempFile("GetMBSerial",".vbs");
          file.deleteOnExit();
          FileWriter fw = new FileWriter(file);

          String vbs =
             "Set objWMIService = GetObject(\"winmgmts:\\\\.\\root\\cimv2\")\n"
            + "Set colItems = objWMIService.ExecQuery _ \n"
            + "   (\"Select * from Win32_ComputerSystemProduct\") \n"
            + "For Each objItem in colItems \n"
            + "    Wscript.Echo objItem.IdentifyingNumber \n"
            + "Next \n";

          fw.write(vbs);
          fw.close();
          Process gWMI = Runtime.getRuntime().exec("cscript //NoLogo " + file.getPath());
          BufferedReader input = new BufferedReader(new InputStreamReader(gWMI.getInputStream()));
          String line;
          while ((line = input.readLine()) != null) {
             result += line;
             System.out.println(line);
          }
          input.close();
        }
        catch(Exception e){
            e.printStackTrace();
        }
        result = result.trim();
        return result;
      }

Bootstrap 4 File Input

I just solved it this way

Html:

<div class="custom-file">
   <input id="logo" type="file" class="custom-file-input">
   <label for="logo" class="custom-file-label text-truncate">Choose file...</label>
</div>

JS:

$('.custom-file-input').on('change', function() { 
   let fileName = $(this).val().split('\\').pop(); 
   $(this).next('.custom-file-label').addClass("selected").html(fileName); 
});

Note: Thanks to ajax333221 for mentioning the .text-truncate class that will hide the overflow within label if the selected file name is too long.

Create XML file using java

You might want to give XStream a shot, it is not complicated. It basically does the heavy lifting.

Where is the Java SDK folder in my computer? Ubuntu 12.04

In generally, java gets installed at /usr/lib/jvm . That is where my sun jdk is installed. check if it is same for open jdk also.

Checking if my Windows application is running

you need a way to say that "i am running" from the app,

1) open a WCF ping service 2) write to registry/file on startup and delete on shutdown 3) create a Mutex

... i prefer the WCF part because you may not clean up file/registry correctly and Mutex seems to have its own issues

How to replace a whole line with sed?

This might work for you:

cat <<! | sed '/aaa=\(bbb\|ccc\|ddd\)/!s/\(aaa=\).*/\1xxx/'
> aaa=bbb
> aaa=ccc
> aaa=ddd
> aaa=[something else]
!
aaa=bbb
aaa=ccc
aaa=ddd
aaa=xxx

fitting data with numpy

Unfortunately, np.polynomial.polynomial.polyfit returns the coefficients in the opposite order of that for np.polyfit and np.polyval (or, as you used np.poly1d). To illustrate:

In [40]: np.polynomial.polynomial.polyfit(x, y, 4)
Out[40]: 
array([  84.29340848, -100.53595376,   44.83281408,   -8.85931101,
          0.65459882])

In [41]: np.polyfit(x, y, 4)
Out[41]: 
array([   0.65459882,   -8.859311  ,   44.83281407, -100.53595375,
         84.29340846])

In general: np.polynomial.polynomial.polyfit returns coefficients [A, B, C] to A + Bx + Cx^2 + ..., while np.polyfit returns: ... + Ax^2 + Bx + C.

So if you want to use this combination of functions, you must reverse the order of coefficients, as in:

ffit = np.polyval(coefs[::-1], x_new)

However, the documentation states clearly to avoid np.polyfit, np.polyval, and np.poly1d, and instead to use only the new(er) package.

You're safest to use only the polynomial package:

import numpy.polynomial.polynomial as poly

coefs = poly.polyfit(x, y, 4)
ffit = poly.polyval(x_new, coefs)
plt.plot(x_new, ffit)

Or, to create the polynomial function:

ffit = poly.Polynomial(coefs)    # instead of np.poly1d
plt.plot(x_new, ffit(x_new))

fit and data plot

Detect whether Excel workbook is already open

Is there a short cut for going back to the beginning of a file by vi editor?

using :<line number> you can navigate to any line, thus :1 takes you to the first line.

How do I revert all local changes in Git managed project to previous state?

DANGER AHEAD: (please read the comments. Executing the command proposed in my answer might delete more than you want)

to completely remove all files including directories I had to run

git clean -f -d

XSL xsl:template match="/"

The match attribute indicates on which parts the template transformation is going to be applied. In that particular case the "/" means the root of the xml document. The value you have to provide into the match attribute should be XPath expression. XPath is the language you have to use to refer specific parts of the target xml file.

To gain a meaningful understanding of what else you can put into match attribute you need to understand what xpath is and how to use it. I suggest yo look at links I've provided for youat the bottom of the answer.

Could I write "table" or any other html tag instead of "/" ?

Yes you can. But this depends what exactly you are trying to do. if your target xml file contains HMTL elements and you are triyng to apply this xsl:template on them it makes sense to use table, div or anithing else.

Here a few links:

XSL templates
XPath
A good book about XML - Beginning XML

Calling a Function defined inside another function in Javascript

Again, not a direct answer to the question, but was led here by a web search. Ended up exposing the inner function without using return, etc. by simply assigning it to a global variable.

var fname;

function outer() {
    function inner() {
        console.log("hi");
    }
    fname = inner;
}

Now just

fname();

MSSQL Error 'The underlying provider failed on Open'

I had the same issue few days ago, using "Integrated Security=True;" in the connection string you need to run the application pool identity under "localsystem" Sure this is not recommended but for testing it does the job.

This is how you can change the identity in IIS 7: http://www.iis.net/learn/manage/configuring-security/application-pool-identities

Kubernetes Pod fails with CrashLoopBackOff

The issue caused by the docker container which exits as soon as the "start" process finishes. i added a command that runs forever and it worked. This issue mentioned here

Programmatically get height of navigation bar

With iPhone-X, height of top bar (navigation bar + status bar) is changed (increased).

Try this if you want exact height of top bar (both navigation bar + status bar):

UPDATE

iOS 13

As the statusBarFrame was deprecated in iOS13 you can use this:

extension UIViewController {

    /**
     *  Height of status bar + navigation bar (if navigation bar exist)
     */

    var topbarHeight: CGFloat {
        return (view.window?.windowScene?.statusBarManager?.statusBarFrame.height ?? 0.0) +
            (self.navigationController?.navigationBar.frame.height ?? 0.0)
    }
}

Objective-C

CGFloat topbarHeight = ([UIApplication sharedApplication].statusBarFrame.size.height +
       (self.navigationController.navigationBar.frame.size.height ?: 0.0));

Swift 4

let topBarHeight = UIApplication.shared.statusBarFrame.size.height +
        (self.navigationController?.navigationBar.frame.height ?? 0.0)

For ease, try this UIViewController extension

extension UIViewController {

    /**
     *  Height of status bar + navigation bar (if navigation bar exist)
     */

    var topbarHeight: CGFloat {
        return UIApplication.shared.statusBarFrame.size.height +
            (self.navigationController?.navigationBar.frame.height ?? 0.0)
    }
}

Swift 3

let topBarHeight = UIApplication.sharedApplication().statusBarFrame.size.height +
(self.navigationController?.navigationBar.frame.height ?? 0.0)

Get CPU Usage from Windows Command Prompt

For anyone that stumbles upon this page, none of the solutions here worked for me. I found this is the way to do it (in a batch file):

@for /f "skip=1" %%p in ('wmic cpu get loadpercentage /VALUE') do (
   for /F "tokens=2 delims==" %%J in ("%%p") do echo %%J
)

How to add to an existing hash in Ruby

hash {}
hash[:a] = 'a'
hash[:b] = 'b'
hash = {:a => 'a' , :b = > b}

You might get your key and value from user input, so you can use Ruby .to_sym can convert a string to a symbol, and .to_i will convert a string to an integer.
For example:

movies ={}
movie = gets.chomp
rating = gets.chomp
movies[movie.to_sym] = rating.to_int
# movie will convert to a symbol as a key in our hash, and 
# rating will be an integer as a value.

How to Code Double Quotes via HTML Codes

There really aren't any differences.

" is processed as " which is the decimal equivalent of &x22; which is the ISO 8859-1 equivalent of ".

The only reason you may be against using " is because it was mistakenly omitted from the HTML 3.2 specification.

Otherwise it all boils down to personal preference.

Trim characters in Java

`CharMatcher` – Google Guava

In the past, I'd second Colins’ Apache commons-lang answer. But now that Google’s guava-libraries is released, the CharMatcher class will do what you want quite nicely:

String j = CharMatcher.is('\\').trimFrom("\\joe\\jill\\"); 
// j is now joe\jill

CharMatcher has a very simple and powerful set of APIs as well as some predefined constants which make manipulation very easy. For example:

CharMatcher.is(':').countIn("a:b:c"); // returns 2
CharMatcher.isNot(':').countIn("a:b:c"); // returns 3
CharMatcher.inRange('a', 'b').countIn("a:b:c"); // returns 2
CharMatcher.DIGIT.retainFrom("a12b34"); // returns "1234"
CharMatcher.ASCII.negate().removeFrom("a®¶b"); // returns "ab";

Very nice stuff.

Sum of values in an array using jQuery

In http://bugs.jquery.com/ticket/1886 it becomes obvious that the jQuery devs have serious mental issues reg. functional programming inspired additions. Somehow it's good to have some fundamental things (like map) but not others (like reduce), unless it reduces jQuery's overall filesize. Go figure.

Helpfully, someone placed code to use the normal reduce function for jQuery arrays:

$.fn.reduce = [].reduce;

Now we can use a simple reduce function to create a summation:

//where X is a jQuery array
X.reduce(function(a,b){ return a + b; });
// (change "a" into parseFloat("a") if the first a is a string)

Lastly, as some older browsers hadn't yet implemented reduce, a polyfill can be taken from MDN (it's big but I guess it has the exact same behavior, which is desirable):

if ( 'function' !== typeof Array.prototype.reduce ) {
    Array.prototype.reduce = function( callback /*, initialValue*/ ) {
        'use strict';
        if ( null === this || 'undefined' === typeof this ) {
          throw new TypeError(
             'Array.prototype.reduce called on null or undefined' );
        }
        if ( 'function' !== typeof callback ) {
          throw new TypeError( callback + ' is not a function' );
        }
        var t = Object( this ), len = t.length >>> 0, k = 0, value;
        if ( arguments.length >= 2 ) {
          value = arguments[1];
        } else {
          while ( k < len && ! k in t ) k++; 
          if ( k >= len )
            throw new TypeError('Reduce of empty array with no initial value');
          value = t[ k++ ];
        }
        for ( ; k < len ; k++ ) {
          if ( k in t ) {
             value = callback( value, t[k], k, t );
          }
        }
        return value;
      };
    }

How can I use Ruby to colorize the text output to a terminal?

I wrote a little method to test out the basic color modes, based on answers by Erik Skoglund and others.

#outputs color table to console, regular and bold modes
def colortable
  names = %w(black red green yellow blue pink cyan white default)
  fgcodes = (30..39).to_a - [38]

  s = ''
  reg  = "\e[%d;%dm%s\e[0m"
  bold = "\e[1;%d;%dm%s\e[0m"
  puts '                       color table with these background codes:'
  puts '          40       41       42       43       44       45       46       47       49'
  names.zip(fgcodes).each {|name,fg|
    s = "#{fg}"
    puts "%7s "%name + "#{reg}  #{bold}   "*9 % [fg,40,s,fg,40,s,  fg,41,s,fg,41,s,  fg,42,s,fg,42,s,  fg,43,s,fg,43,s,  
      fg,44,s,fg,44,s,  fg,45,s,fg,45,s,  fg,46,s,fg,46,s,  fg,47,s,fg,47,s,  fg,49,s,fg,49,s ]
  }
end

example output: ruby colortest

Why does an onclick property set with setAttribute fail to work in IE?

Write the function inline, and the interpreter is smart enough to know you're writing a function. Do it like this, and it assumes it's just a string (which it technically is).

String escape into XML

public static string XmlEscape(string unescaped)
{
    XmlDocument doc = new XmlDocument();
    XmlNode node = doc.CreateElement("root");
    node.InnerText = unescaped;
    return node.InnerXml;
}

public static string XmlUnescape(string escaped)
{
    XmlDocument doc = new XmlDocument();
    XmlNode node = doc.CreateElement("root");
    node.InnerXml = escaped;
    return node.InnerText;
}

How to detect simple geometric shapes using OpenCV

The answer depends on the presence of other shapes, level of noise if any and invariance you want to provide for (e.g. rotation, scaling, etc). These requirements will define not only the algorithm but also required pre-procesing stages to extract features.

Template matching that was suggested above works well when shapes aren't rotated or scaled and when there are no similar shapes around; in other words, it finds a best translation in the image where template is located:

double minVal, maxVal;
Point minLoc, maxLoc;
Mat image, template, result; // template is your shape
matchTemplate(image, template, result, CV_TM_CCOEFF_NORMED);
minMaxLoc(result, &minVal, &maxVal, &minLoc, &maxLoc); // maxLoc is answer

Geometric hashing is a good method to get invariance in terms of rotation and scaling; this method would require extraction of some contour points.

Generalized Hough transform can take care of invariance, noise and would have minimal pre-processing but it is a bit harder to implement than other methods. OpenCV has such transforms for lines and circles.

In the case when number of shapes is limited calculating moments or counting convex hull vertices may be the easiest solution: openCV structural analysis

Font-awesome, input type 'submit'

HTML

Since <input> element displays only value of value attribute, we have to manipulate only it:

<input type="submit" class="btn fa-input" value="&#xf043; Input">

I'm using  entity here, which corresponds to the U+F043, the Font Awesome's 'tint' symbol.

CSS

Then we have to style it to use the font:

.fa-input {
  font-family: FontAwesome, 'Helvetica Neue', Helvetica, Arial, sans-serif;
}

Which will give us the tint symbol in Font Awesome and the other text in the appropriate font.

However, this control will not be pixel-perfect, so you might have to tweak it by yourself.

Is it possible to specify proxy credentials in your web.config?

You can specify credentials by adding a new Generic Credential of your proxy server in Windows Credentials Manager:

1 In Web.config

<system.net>    
<defaultProxy enabled="true" useDefaultCredentials="true">      
<proxy usesystemdefault="True" />      
</defaultProxy>    
</system.net>

In Credential Manager >> Add a Generic Credential

Internet or network address: your proxy address
User name: your user name
Password: you pass

This configuration worked for me, without change the code.

WCFTestClient The HTTP request is unauthorized with client authentication scheme 'Anonymous'

I didn't have control over the security configuration for the service I was calling into, but got the same error. I was able to fix my client as follows.

In the config, set up the security mode:

<security mode="TransportCredentialOnly">
  <transport clientCredentialType="Windows" proxyCredentialType="None" realm="" />
  <message clientCredentialType="UserName" algorithmSuite="Default" />
</security>

In the code, set the proxy class to allow impersonation (I added a reference to a service called customer):

Customer_PortClient proxy = new Customer_PortClient();
proxy.ClientCredentials.Windows.AllowedImpersonationLevel =    
         System.Security.Principal.TokenImpersonationLevel.Impersonation;

How to create a directory and give permission in single command

Don't do: mkdir -m 777 -p a/b/c since that will only set permission 777 on the last directory, c; a and b will be created with the default permission from your umask.

Instead to create any new directories with permission 777, run mkdir -p in a subshell where you override the umask:

(umask u=rwx,g=rwx,o=rwx && mkdir -p a/b/c)

Note that this won't change the permissions if any of a, b and c already exist though.

eclipse stuck when building workspace

Deleting some of the JDT indexes (in .metadata.plugins\org.eclipse.jdt.core), particularly the big files, often fix or ease the problem for me.

Python Remove last char from string and return it

I decided to go with a for loop and just avoid the item in question, is it an acceptable alternative?

new = ''
for item in str:
    if item == str[n]:
        continue
    else:
        new += item

How do I wrap text in a span?

Try putting your text in another div inside your span:

i.e.

<span><div>some text</div></span>

What is the `data-target` attribute in Bootstrap 3?

data-target is used by bootstrap to make your life easier. You (mostly) do not need to write a single line of Javascript to use their pre-made JavaScript components.

The data-target attribute should contain a CSS selector that points to the HTML Element that will be changed.

Modal Example Code from BS3:

<!-- Button trigger modal -->
<button class="btn btn-primary btn-lg" data-toggle="modal" data-target="#myModal">
  Launch demo modal
</button>

<!-- Modal -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
  [...]
</div>

In this example, the button has data-target="#myModal", if you click on it, <div id="myModal">...</div> will be modified (in this case faded in). This happens because #myModal in CSS selectors points to elements that have an id attribute with the myModal value.

Further information about the HTML5 "data-" attribute: https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Using_data_attributes

How to automatically allow blocked content in IE?

You have two options:

Use a Mark of the Web. This will enable a single html page to load. It See here for details. To do this, add the following to your web page below the doctype and above the html tag:
Disable this feature. To do so go to Internet Options->Advanced->Security->Allow Active Content... Then close IE. When you restart IE, it will not give you this error.

Registry key Error: Java version has value '1.8', but '1.7' is required

just did this and it worked

HKLM > SOFTWARE > JavaSoft > Java Runtime Environment

just manually change current version to 1.7 .

lol ... but it worked!

No value accessor for form control with name: 'recipient'

Make sure you import MaterialModule as well since you are using md-input which does not belong to FormsModule

Easy way to turn JavaScript array into comma-separated list?

Use the built-in Array.toString method

var arr = ['one', 'two', 'three'];
arr.toString();  // 'one,two,three'

MDN on Array.toString()

How to store phone numbers on MySQL databases?

Form my point of view, below is my suggestions:

Store phone number into a single field as varchar and if you need to split then after retrieve split accordingly.
If you store as number then preceding 0 will truncate, so always store as varchar
Validate users phone number before inserting into your table.

vim - How to delete a large block of text without counting the lines?

You could place your cursor at the beginning or end of the block and enter visual mode (shift-v). Then simply move up or down until the desired block is highlighted. Finally, copy the text by pressing y or cut the text by pressing d.

Programs & Examples On #Helpermethods

Can Rails Routing Helpers (i.e. mymodel_path(model)) be Used in Models?

What is the difference between window, screen, and document in Javascript?

window

document

screen

C++ getters/setters coding style

Can't connect to docker from docker-compose

Deleting a pointer in C++

What is your most productive shortcut with Vim?

How to change app default theme to a different app theme?

Regular expression to search multiple strings (Textpad)

How do we download a blob url video

SyntaxError: Use of const in strict mode?

DNS problem, nslookup works, ping doesn't

To fix this you will need to alter the DNS setting for the machine and add the DNS suffix to lookup.

How to convert string to date to string in Swift iOS?

How to sparsely checkout only one single file from a git repository?

How do I authenticate a WebClient request?

How do I launch a program from command line without opening a new cmd window?

MySQL error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near

Disable dragging an image from an HTML page

Update Fragment from ViewPager

raw vs. html_safe vs. h to unescape html

How to import a JSON file in ECMAScript 6?

How to set proxy for wget?

How to make a Qt Widget grow with the window size?

Android Studio : How to uninstall APK (or execute adb command) automatically before Run or Debug?

Difference between "managed" and "unmanaged"

Creating SVG elements dynamically with javascript inside HTML

Pass accepts header parameter to jquery ajax

Recommended SQL database design for tags or tagging

Programmatically generate video or animated GIF in Python?

Selecting specific rows and columns from NumPy array

[Edit] The built-in method: np.ix_

Is there a way to view past mysql queries with phpmyadmin?

How to append strings using sprintf?

Format date to MM/dd/yyyy in JavaScript

ISO compliant dateString

Non-standard date string

How to change text color and console color in code::blocks?

How do I get first element rather than using [0] in jQuery?

Gson - convert from Json to a typed ArrayList<T>

string.Replace in AngularJs

Which Radio button in the group is checked?

Updating an object with setState in React

How do I get whole and fractional parts from double in JSP/Java?

Difference between links and depends_on in docker_compose.yml

Add new column with foreign key constraint in one command

Flexbox not working in Internet Explorer 11

See "Can I Use" for the full list of IE11 Flexbox bugs and more

Are table names in MySQL case sensitive?

How do I tell if .NET 3.5 SP1 is installed?

How to define a variable in a Dockerfile?

java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)

Delete entire row if cell contains the string X

Error in Python IOError: [Errno 2] No such file or directory: 'data.csv'

Fastest way to check if a string is JSON in PHP?

Is this really the fastest method?

The "maybe decode" logic/code

Extra: Use this logic to safely double-decode JSON

How to remove backslash on json_encode() function?

Argument Exception "Item with Same Key has already been added"

In MS DOS copying several files to one file

How to change the pop-up position of the jQuery DatePicker control

JavaScript console.log causes error: "Synchronous XMLHttpRequest on the main thread is deprecated..."

How to add an empty column to a dataframe?

How to negate code in "if" statement block in JavaScript -JQuery like 'if not then..'

Select all occurrences of selected word in VSCode

How to add to the PYTHONPATH in Windows, so it finds my modules/packages?

Which is the best IDE for Python For Windows

How should I do integer division in Perl?

Parsing a pcap file in python

Finding version of Microsoft C++ compiler from command-line (for makefiles)

Can't bind to 'formGroup' since it isn't a known property of 'form'

WaitAll vs WhenAll

get unique machine id

make: Nothing to be done for `all'

Stopping an Android app from console

Why is it important to override GetHashCode when Equals method is overridden?

`window`

`document`

`screen`

[Edit] The built-in method: `np.ix_`

Cannot find reference 'xxx' in init.py - Python / Pycharm