Programs & Examples On #Gen fsm

gen_fsm stands for "generic finite state machine", a module behaviour in Erlang.

Can't use System.Windows.Forms

go to the side project panel, right click on references -> add reference and find System.Windows.Forms

Any time some error like this occurs (some namespace you added is missing that is obviously there) the solution is probably this - adding a reference.

This is needed because your default project does not include everything because you probably wont need it so it saves space. A good practice is to exclude things you're not using.

How to schedule a task to run when shutting down windows

Execute gpedit.msc (local Policies)

Computer Configuration -> Windows settings -> Scripts -> Shutdown -> Properties -> Add

jQuery checkbox onChange

There is a typo error :

$('#activelist :checkbox')...

Should be :

$('#inactivelist:checkbox')...

Number of regex matches

If you know you will want all the matches, you could use the re.findall function. It will return a list of all the matches. Then you can just do len(result) for the number of matches.

git push to specific branch

The answers in question you linked-to are all about configuring git so that you can enter very short git push commands and have them do whatever you want. Which is great, if you know what you want and how to spell that in Git-Ese, but you're new to git! :-)

In your case, Petr Mensik's answer is the (well, "a") right one. Here's why:

The command git push remote roots around in your .git/config file to find the named "remote" (e.g., origin). The config file lists:

  • where (URL-wise) that remote "lives" (e.g., ssh://hostname/path)
  • where pushes go, if different
  • what gets pushed, if you didn't say what branch(es) to push
  • what gets fetched when you run git fetch remote

When you first cloned the repo—whenever that was—git set up default values for some of these. The URL is whatever you cloned from and the rest, if set or unset, are all "reasonable" defaults ... or, hmm, are they?

The issue with these is that people have changed their minds, over time, as to what is "reasonable". So now (depending on your version of git and whether you've configured things in detail), git may print a lot of warnings about defaults changing in the future. Adding the name of the "branch to push"—amd_qlp_tester—(1) shuts it up, and (2) pushes just that one branch.

If you want to push more conveniently, you could do that with:

git push origin

or even:

git push

but whether that does what you want, depends on whether you agree with "early git authors" that the original defaults are reasonable, or "later git authors" that the original defaults aren't reasonable. So, when you want to do all the configuration stuff (eventually), see the question (and answers) you linked-to.

As for the name origin/amd_qlp_tester in the first place: that's actually a local entity (a name kept inside your repo), even though it's called a "remote branch". It's git's best guess at "where amd_qlp_tester is over there". Git updates it when it can.

Converting from a string to boolean in Python?

Starting with Python 2.6, there is now ast.literal_eval:

>>> import ast
>>> help(ast.literal_eval)
Help on function literal_eval in module ast:

literal_eval(node_or_string)
    Safely evaluate an expression node or a string containing a Python
    expression.  The string or node provided may only consist of the following
    Python literal structures: strings, numbers, tuples, lists, dicts, booleans,
    and None.

Which seems to work, as long as you're sure your strings are going to be either "True" or "False":

>>> ast.literal_eval("True")
True
>>> ast.literal_eval("False")
False
>>> ast.literal_eval("F")
Traceback (most recent call last):
  File "", line 1, in 
  File "/opt/Python-2.6.1/lib/python2.6/ast.py", line 68, in literal_eval
    return _convert(node_or_string)
  File "/opt/Python-2.6.1/lib/python2.6/ast.py", line 67, in _convert
    raise ValueError('malformed string')
ValueError: malformed string
>>> ast.literal_eval("'False'")
'False'

I wouldn't normally recommend this, but it is completely built-in and could be the right thing depending on your requirements.

What do pty and tty mean?

If you run the mount command with no command-line arguments, which displays the file systems mounted on your system, you’ll notice a line that looks something like this: none on /dev/pts type devpts (rw,gid=5,mode=620) This indicates that a special type of file system, devpts , is mounted at /dev/pts .This file system, which isn’t associated with any hardware device, is a “magic” file system that is created by the Linux kernel. It’s similar to the /proc file system

Like the /dev directory, /dev/pts contains entries corresponding to devices. But unlike /dev , which is an ordinary directory, /dev/pts is a special directory that is cre- ated dynamically by the Linux kernel.The contents of the directory vary with time and reflect the state of the running system. The entries in /dev/pts correspond to pseudo-terminals (or pseudo-TTYs, or PTYs).

Linux creates a PTY for every new terminal window you open and displays a corre- sponding entry in /dev/pts .The PTY device acts like a terminal device—it accepts input from the keyboard and displays text output from the programs that run in it. PTYs are numbered, and the PTY number is the name of the corresponding entry in /dev/pts .

For example, if the new terminal window’s PTY number is 7, invoke this command from another window: % echo ‘I am a virtual di ’ > /dev/pts/7 The output appears in the new terminal window.

Connection attempt failed with "ECONNREFUSED - Connection refused by server"

I solved this error

A connection attempt failed with "ECONNREFUSED - Connection refused by server"

by changing my port to 22 that was successful

Get random sample from list while maintaining ordering of items?

Apparently random.sample was introduced in python 2.3

so for version under that, we can use shuffle (example for 4 items):

myRange =  range(0,len(mylist)) 
shuffle(myRange)
coupons = [ bestCoupons[i] for i in sorted(myRange[:4]) ]

Why es6 react component works only with "export default"?

Add { } while importing and exporting: export { ... }; | import { ... } from './Template';

exportimport { ... } from './Template'

export defaultimport ... from './Template'


Here is a working example:

// ExportExample.js
import React from "react";

function DefaultExport() {
  return "This is the default export";
}

function Export1() {
  return "Export without default 1";
}

function Export2() {
  return "Export without default 2";
}

export default DefaultExport;
export { Export1, Export2 };

// App.js
import React from "react";
import DefaultExport, { Export1, Export2 } from "./ExportExample";

export default function App() {
  return (
    <>
      <strong>
        <DefaultExport />
      </strong>
      <br />
      <Export1 />
      <br />
      <Export2 />
    </>
  );
}

??Working sandbox to play around: https://codesandbox.io/s/export-import-example-react-jl839?fontsize=14&hidenavigation=1&theme=dark

How to check if a variable is equal to one string or another string?

This does not do what you expect:

if var is 'stringone' or 'stringtwo':
    dosomething()

It is the same as:

if (var is 'stringone') or 'stringtwo':
    dosomething()

Which is always true, since 'stringtwo' is considered a "true" value.

There are two alternatives:

if var in ('stringone', 'stringtwo'):
    dosomething()

Or you can write separate equality tests,

if var == 'stringone' or var == 'stringtwo':
    dosomething()

Don't use is, because is compares object identity. You might get away with it sometimes because Python interns a lot of strings, just like you might get away with it in Java because Java interns a lot of strings. But don't use is unless you really want object identity.

>>> 'a' + 'b' == 'ab'
True
>>> 'a' + 'b' is 'abc'[:2]
False # but could be True
>>> 'a' + 'b' is 'ab'
True  # but could be False

Access to build environment variables from a groovy script in a Jenkins build step (Windows)

One thing to note, if you are using a freestyle job, you won't be able to access build parameters or the Jenkins JVM's environment UNLESS you are using System Groovy Script build steps. I spent hours googling and researching before gathering enough clues to figure that out.

openssl s_client -cert: Proving a client certificate was sent to the server

In order to verify a client certificate is being sent to the server, you need to analyze the output from the combination of the -state and -debug flags.

First as a baseline, try running

$ openssl s_client -connect host:443 -state -debug

You'll get a ton of output, but the lines we are interested in look like this:

SSL_connect:SSLv3 read server done A
write to 0x211efb0 [0x21ced50] (12 bytes => 12 (0xC))
0000 - 16 03 01 00 07 0b 00 00-03                        .........
000c - <SPACES/NULS>
SSL_connect:SSLv3 write client certificate A

What's happening here:

  • The -state flag is responsible for displaying the end of the previous section:

    SSL_connect:SSLv3 read server done A  
    

    This is only important for helping you find your place in the output.

  • Then the -debug flag is showing the raw bytes being sent in the next step:

    write to 0x211efb0 [0x21ced50] (12 bytes => 12 (0xC))
    0000 - 16 03 01 00 07 0b 00 00-03                        .........
    000c - <SPACES/NULS>
    
  • Finally, the -state flag is once again reporting the result of the step that -debug just echoed:

    SSL_connect:SSLv3 write client certificate A
    

So in other words: s_client finished reading data sent from the server, and sent 12 bytes to the server as (what I assume is) a "no client certificate" message.


If you repeat the test, but this time include the -cert and -key flags like this:

$ openssl s_client -connect host:443 \
   -cert cert_and_key.pem \
   -key cert_and_key.pem  \
   -state -debug

your output between the "read server done" line and the "write client certificate" line will be much longer, representing the binary form of your client certificate:

SSL_connect:SSLv3 read server done A
write to 0x7bd970 [0x86d890] (1576 bytes => 1576 (0x628))
0000 - 16 03 01 06 23 0b 00 06-1f 00 06 1c 00 06 19 31   ....#..........1
(*SNIP*)
0620 - 95 ca 5e f4 2f 6c 43 11-                          ..^%/lC.
SSL_connect:SSLv3 write client certificate A

The 1576 bytes is an excellent indication on its own that the cert was transmitted, but on top of that, the right-hand column will show parts of the certificate that are human-readable: You should be able to recognize the CN and issuer strings of your cert in there.

Android "elevation" not showing a shadow

If you want to have transparent background and android:outlineProvider="bounds" doesn't work for you, you can create custom ViewOutlineProvider:

class TransparentOutlineProvider extends ViewOutlineProvider {

    @Override
    public void getOutline(View view, Outline outline) {
        ViewOutlineProvider.BACKGROUND.getOutline(view, outline);
        Drawable background = view.getBackground();
        float outlineAlpha = background == null ? 0f : background.getAlpha()/255f;
        outline.setAlpha(outlineAlpha);
    }
}

And set this provider to your transparent view:

transparentView.setOutlineProvider(new TransparentOutlineProvider());

Sources: https://code.google.com/p/android/issues/detail?id=78248#c13

[EDIT] Documentation of Drawable.getAlpha() says that it is specific to how the Drawable threats the alpha. It is possible that it will always return 255. In this case you can provide the alpha manually:

class TransparentOutlineProvider extends ViewOutlineProvider {

    private float mAlpha;

    public TransparentOutlineProvider(float alpha) {
        mAlpha = alpha;
    }

    @Override
    public void getOutline(View view, Outline outline) {
        ViewOutlineProvider.BACKGROUND.getOutline(view, outline);
        outline.setAlpha(mAlpha);
    }
}

If your view background is a StateListDrawable with default color #DDFF0000 that is with alpha DDx0/FFx0 == 0.86

transparentView.setOutlineProvider(new TransparentOutlineProvider(0.86f));

XPath:: Get following Sibling

/html/body/table/tbody/tr[9]/td[1]

In Chrome (possible Safari too) you can inspect an element, then right click on the tag you want to get the xpath for, then you can copy the xpath to select that element.

Connection to SQL Server Works Sometimes

In my case above all options were already there.

Solved it by increasing Connection Time-out = 30.SQL Server management Studio

Create a unique number with javascript time

let uuid = ((new Date().getTime()).toString(36))+'_'+(Date.now() + Math.random().toString()).split('.').join("_")

sample result "k3jobnvt_15750033412250_18299601769317408"

ORA-12170: TNS:Connect timeout occurred

TROUBLESHOOTING STEPS (Doc ID 730066.1)

Connection Timeout errors ORA-3135 and ORA-3136 A connection timeout error can be issued when an attempt to connect to the database does not complete its connection and authentication phases within the time period allowed by the following: SQLNET.INBOUND_CONNECT_TIMEOUT and/or INBOUND_CONNECT_TIMEOUT_ server-side parameters.

Starting with Oracle 10.2, the default for these parameters is 60 seconds where in previous releases it was 0, meaning no timeout.

On a timeout, the client program will receive the ORA-3135 (or possibly TNS-3135) error:

ORA-3135 connection lost contact

and the database will log the ORA-3136 error in its alert.log:

... Sat May 10 02:21:38 2008 WARNING: inbound connection timed out (ORA-3136) ...

  • Authentication SQL

When a database session is in the authentication phase, it will issue a sequence of SQL statements. The authentication is not complete until all these are parsed, executed, fetched completely. Some of the SQL statements in this list e.g. on 10.2 are:

select value$ from props$ where name = 'GLOBAL_DB_NAME'

select privilege#,level from sysauth$ connect by grantee#=prior privilege# 
and privilege#>0 start with grantee#=:1 and privilege#>0

select SYS_CONTEXT('USERENV', 'SERVER_HOST'), SYS_CONTEXT('USERENV', 'DB_UNIQUE_NAME'),
SYS_CONTEXT('USERENV', 'INSTANCE_NAME'), SYS_CONTEXT('USERENV', 'SERVICE_NAME'), 
INSTANCE_NUMBER, STARTUP_TIME, SYS_CONTEXT('USERENV', 'DB_DOMAIN') 
from v$instance where INSTANCE_NAME=SYS_CONTEXT('USERENV', 'INSTANCE_NAME')

select privilege# from sysauth$ where (grantee#=:1 or grantee#=1) and privilege#>0

ALTER SESSION SET NLS_LANGUAGE= 'AMERICAN' NLS_TERRITORY= 'AMERICA' NLS_CURRENCY= '$'
NLS_ISO_CURRENCY= 'AMERICA' NLS_NUMERIC_CHARACTERS= '.,' NLS_CALENDAR= 'GREGORIAN'
NLS_DATE_FORMAT= 'DD-MON-RR' NLS_DATE_LANGUAGE= 'AMERICAN' NLS_SORT= 'BINARY' TIME_ZONE= '+02:00'
NLS_COMP= 'BINARY' NLS_DUAL_CURRENCY= '$' NLS_TIME_FORMAT= 'HH.MI.SSXFF AM' NLS_TIMESTAMP_FORMAT=
'DD-MON-RR HH.MI.SSXFF AM' NLS_TIME_TZ_FORMAT= 'HH.MI.SSXFF AM TZR' NLS_TIMESTAMP_TZ_FORMAT=
'DD-MON-RR HH.MI.SSXFF AM TZR'

NOTE: The list of SQL above is not complete and does not represent the ordering of the authentication SQL . Differences may also exist from release to release.

  • Hangs during Authentication

The above SQL statements need to be Parsed, Executed and Fetched as happens for all SQL inside an Oracle Database. It follows that any problem encountered during these phases which appears as a hang or severe slow performance may result in a timeout.

Symptoms of such hangs will be seen by the authenticating session as waits for: • cursor: pin S wait on X • latch: row cache objects • row cache lock Other types of wait events are possible; this list may not be complete.

The issue here is that the authenticating session is blocked waiting to get a shared resource which is held by another session inside the database. That blocker session is itself occupied in a long-running activity (or its own hang) which prevents it from releasing the shared resource needed by the authenticating session in a timely fashion. This results in the timeout being eventually reported to the authenticating session.

  • Troubleshooting of Authentication hangs

In such situations, we need to find out the blocker process holding the shared resource needed by the authenticating session in order to see what is happening to it.

Typical diagnostics used in such cases are the following:

  1. Three consecutive systemstate dumps at level 266 during the time that one or more authenticating sessions are blocked. It is likely that the blocking session will have caused timeouts to more than one connection attempt. Hence, systemstate dumps can be useful even when the time needed to generate them exceeds the period of a single timeout e.g. 60 sec:
      $ sqlplus -prelim '/ as sysdba' 

       oradebug setmypid 
       oradebug unlimit 
       oradebug dump systemstate 266 
       ...wait 90 seconds 
       oradebug dump systemstate 266 
       ...wait 90 seconds 
       oradebug dump systemstate 266 
       quit
  • ASH reports covering e.g. 10-15 minutes of a time period during which several timeout errors were seen.
  • If possible, Two consecutive queries on V$LATCHHOLDER view for the case where the shared resource being waited for is a latch. select * from v$latchholder; The systemstate dumps should help in identifying the blocker session. Level 266 will show us in what code it is executing which may help in locating any existing bug as the root cause.

Examples of issues which can result in Authentication hangs

  • Unpublished Bug 6879763 shared pool simulator bug fixed by patch for unpublished Bug 6966286 see Note 563149.1
  • Unpublished Bug 7039896 workaround parameter _enable_shared_pool_durations=false see Note 7039896.8

  • Other approaches to avoid the problem

In some cases, it may be possible to avoid problems with Authentication SQL by pinning such statements in the Shared Pool soon after the instance is started and they are freshly loaded. You can use the following artcile to advise on this: Document 726780.1 How to Pin a Cursor in the Shared Pool using DBMS_SHARED_POOL.KEEP

Pinning will prevent them from being flushed out due to inactivity and aging and will therefore prevent them for needing to be reloaded in the future i.e. needing to be reparsed and becoming susceptible to Authentication hang issues.

embedding image in html email

The following is working code with two ways of achieving this:

using System;
using Outlook = Microsoft.Office.Interop.Outlook;

namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {

            Method1();
            Method2();
        }

        public static void Method1()
        {
            Outlook.Application outlookApp = new Outlook.Application();
            Outlook.MailItem mailItem = outlookApp.CreateItem(Outlook.OlItemType.olMailItem);
            mailItem.Subject = "This is the subject";
            mailItem.To = "[email protected]";
            string imageSrc = "D:\\Temp\\test.jpg"; // Change path as needed

            var attachments = mailItem.Attachments;
            var attachment = attachments.Add(imageSrc);
            attachment.PropertyAccessor.SetProperty("http://schemas.microsoft.com/mapi/proptag/0x370E001F", "image/jpeg");
            attachment.PropertyAccessor.SetProperty("http://schemas.microsoft.com/mapi/proptag/0x3712001F", "myident"); // Image identifier found in the HTML code right after cid. Can be anything.
            mailItem.PropertyAccessor.SetProperty("http://schemas.microsoft.com/mapi/id/{00062008-0000-0000-C000-000000000046}/8514000B", true);

            // Set body format to HTML

            mailItem.BodyFormat = Outlook.OlBodyFormat.olFormatHTML;
            string msgHTMLBody = "<html><head></head><body>Hello,<br><br>This is a working example of embedding an image unsing C#:<br><br><img align=\"baseline\" border=\"1\" hspace=\"0\" src=\"cid:myident\" width=\"\" 600=\"\" hold=\" /> \"></img><br><br>Regards,<br>Tarik Hoshan</body></html>";
            mailItem.HTMLBody = msgHTMLBody;
            mailItem.Send();
        }

        public static void Method2()
        {

            // Create the Outlook application.
            Outlook.Application outlookApp = new Outlook.Application();

            Outlook.MailItem mailItem = (Outlook.MailItem)outlookApp.CreateItem(Outlook.OlItemType.olMailItem);

            //Add an attachment.
            String attachmentDisplayName = "MyAttachment";

            // Attach the file to be embedded
            string imageSrc = "D:\\Temp\\test.jpg"; // Change path as needed

            Outlook.Attachment oAttach = mailItem.Attachments.Add(imageSrc, Outlook.OlAttachmentType.olByValue, null, attachmentDisplayName);

            mailItem.Subject = "Sending an embedded image";

            string imageContentid = "someimage.jpg"; // Content ID can be anything. It is referenced in the HTML body

            oAttach.PropertyAccessor.SetProperty("http://schemas.microsoft.com/mapi/proptag/0x3712001E", imageContentid);

            mailItem.HTMLBody = String.Format(
                "<body>Hello,<br><br>This is an example of an embedded image:<br><br><img src=\"cid:{0}\"><br><br>Regards,<br>Tarik</body>",
                imageContentid);

            // Add recipient
            Outlook.Recipient recipient = mailItem.Recipients.Add("[email protected]");
            recipient.Resolve();

            // Send.
            mailItem.Send();
        }
    }
}

Error "There is already an open DataReader associated with this Command which must be closed first" when using 2 distinct commands

You can get such a problem when you are two different commands on same connection - especially calling the second command in a loop. That is calling the second command for each record returned from the first command. If there are some 10,000 records returned by the first command, this issue will be more likely.

I used to avoid such a scenario by making it as a single command.. The first command returns all the required data and load it into a DataTable.

Note: MARS may be a solution - but it can be risky and many people dislike it.

Reference

  1. What does "A severe error occurred on the current command. The results, if any, should be discarded." SQL Azure error mean?
  2. Linq-To-Sql and MARS woes - A severe error occurred on the current command. The results, if any, should be discarded
  3. Complex GROUP BY on DataTable

Javascript getElementById based on a partial string

Given that what you want is to determine the full id of the element based upon just the prefix, you're going to have to do a search of the entire DOM (or at least, a search of an entire subtree if you know of some element that is always guaranteed to contain your target element). You can do this with something like:

function findChildWithIdLike(node, prefix) {
    if (node && node.id && node.id.indexOf(prefix) == 0) {
        //match found
        return node;
    }

    //no match, check child nodes
    for (var index = 0; index < node.childNodes.length; index++) {
        var child = node.childNodes[index];
        var childResult = findChildWithIdLike(child, prefix);
        if (childResult) {
            return childResult;
        }
    }
};

Here is an example: http://jsfiddle.net/xwqKh/

Be aware that dynamic element ids like the ones you are working with are typically used to guarantee uniqueness of element ids on a single page. Meaning that it is likely that there are multiple elements that share the same prefix. Probably you want to find them all.

If you want to find all of the elements that have a given prefix, instead of just the first one, you can use something like what is demonstrated here: http://jsfiddle.net/xwqKh/1/

PHP "php://input" vs $_POST

First, a basic truth about PHP.

PHP was not designed to explicitly give you a pure REST (GET, POST, PUT, PATCH, DELETE) like interface for handling HTTP requests.

However, the $_SERVER, $_COOKIE, $_POST, $_GET, and $_FILES superglobals, and the function filter_input_array() are very useful for the average person's / layman's needs.

The number one hidden advantage of $_POST (and $_GET) is that your input data is url-decoded automatically by PHP. You never even think about having to do it, especially for query string parameters within a standard GET request, or HTTP body data submitted with a POST request.

Other HTTP Request Methods

Those studying the underlying HTTP protocol and its various request methods come to understand that there are many HTTP request methods, including the often referenced PUT, PATCH (not used in Google's Apigee), and DELETE.

In PHP, there are no superglobals or input filter functions for getting HTTP request body data when POST is not used. What are disciples of Roy Fielding to do? ;-)

However, then you learn more ...

That being said, as you advance in your PHP programming knowledge and want to use JavaScript's XmlHttpRequest object (jQuery for some), you come to see the limitation of this scheme.

$_POST limits you to the use of two media types in the HTTP Content-Type header:

  1. application/x-www-form-urlencoded, and
  2. multipart/form-data

Thus, if you want to send data values to PHP on the server, and have it show up in the $_POST superglobal, then you must urlencode it on the client-side and send said data as key/value pairs--an inconvenient step for novices (especially when trying to figure out if different parts of the URL require different forms of urlencoding: normal, raw, etc..).

For all you jQuery users, the $.ajax() method is converting your JSON to URL encoded key/value pairs before transmitting them to the server. You can override this behavior by setting processData: false. Just read the $.ajax() documentation, and don't forget to send the correct media type in the Content-Type header.

php://input, but ...

Even if you use php://input instead of $_POST for your HTTP POST request body data, it will not work with an HTTP Content-Type of multipart/form-data This is the content type that you use on an HTML form when you want to allow file uploads!

<form enctype="multipart/form-data" accept-charset="utf-8" action="post">
    <input type="file" name="resume">
</form>

Therefore, in traditional PHP, to deal with a diversity of content types from an HTTP POST request, you will learn to use $_POST or filter_input_array(POST), $_FILES, and php://input. There is no way to just use one, universal input source for HTTP POST requests in PHP.

You cannot get files through $_POST, filter_input_array(POST), or php://input, and you cannot get JSON/XML/YAML in either filter_input_array(POST) or $_POST.

PHP Manual: php://input

php://input is a read-only stream that allows you to read raw data from the request body...php://input is not available with enctype="multipart/form-data".

PHP Frameworks to the rescue?

PHP frameworks like Codeigniter 4 and Laravel use a facade to provide a cleaner interface (IncomingRequest or Request objects) to the above. This is why professional PHP developers use frameworks instead of raw PHP.

Of course, if you like to program, you can devise your own facade object to provide what frameworks do. It is because I have taken time to investigate this issue that I am able to write this answer.

URL encoding? What the heck!!!???

Typically, if you are doing a normal, synchronous (when the entire page redraws) HTTP requests with an HTML form, the user-agent (web browser) will urlencode your form data for you. If you want to do an asynchronous HTTP requests using the XmlHttpRequest object, then you must fashion a urlencoded string and send it, if you want that data to show up in the $_POST superglobal.

How in touch are you with JavaScript? :-)

Converting from a JavaScript array or object to a urlencoded string bothers many developers (even with new APIs like Form Data). They would much rather just be able to send JSON, and it would be more efficient for the client code to do so.

Remember (wink, wink), the average web developer does not learn to use the XmlHttpRequest object directly, global functions, string functions, array functions, and regular expressions like you and I ;-). Urlencoding for them is a nightmare. ;-)

PHP, what gives?

PHP's lack of intuitive XML and JSON handling turns many people off. You would think it would be part of PHP by now (sigh).

So many media types (MIME types in the past)

XML, JSON, and YAML all have media types that can be put into an HTTP Content-Type header.

  • application/xml
  • applicaiton/json
  • application/yaml (although IANA has no official designation listed)

Look how many media-types (formerly, MIME types) are defined by IANA.

Look how many HTTP headers there are.

php://input or bust

Using the php://input stream allows you to circumvent the baby-sitting / hand holding level of abstraction that PHP has forced on the world. :-) With great power comes great responsibility!

Now, before you deal with data values streamed through php://input, you should / must do a few things.

  1. Determine if the correct HTTP method has been indicated (GET, POST, PUT, PATCH, DELETE, ...)
  2. Determine if the HTTP Content-Type header has been transmitted.
  3. Determine if the value for the Content-Type is the desired media type.
  4. Determine if the data sent is well formed XML / JSON / YAML / etc.
  5. If necessary, convert the data to a PHP datatype: array or object.
  6. If any of these basic checks or conversions fails, throw an exception!

What about the character encoding?

AH, HA! Yes, you might want the data stream being sent into your application to be UTF-8 encoded, but how can you know if it is or not?

Two critical problems.

  1. You do not know how much data is coming through php://input.
  2. You do not know for certain the current encoding of the data stream.

Are you going to attempt to handle stream data without knowing how much is there first? That is a terrible idea. You cannot rely exclusively on the HTTP Content-Length header for guidance on the size of streamed input because it can be spoofed.

You are going to need a:

  1. Stream size detection algorithm.
  2. Application defined stream size limits (Apache / Nginx / PHP limits may be too broad).

Are you going to attempt to convert stream data to UTF-8 without knowing the current encoding of the stream? How? The iconv stream filter (iconv stream filter example) seems to want a starting and ending encoding, like this.

'convert.iconv.ISO-8859-1/UTF-8'

Thus, if you are conscientious, you will need:

  1. Stream encoding detection algorithm.
  2. Dynamic / runtime stream filter definition algorithm (because you cannot know the starting encoding a priori).

(Update: 'convert.iconv.UTF-8/UTF-8' will force everything to UTF-8, but you still have to account for characters that the iconv library might not know how to translate. In other words, you have to some how define what action to take when a character cannot be translated: 1) Insert a dummy character, 2) Fail / throw and exception).

You cannot rely exclusively on the HTTP Content-Encoding header, as this might indicate something like compression as in the following. This is not what you want to make a decision off of in regards to iconv.

Content-Encoding: gzip

Therefore, the general steps might be ...

Part I: HTTP Request Related

  1. Determine if the correct HTTP method has been indicated (GET, POST, PUT, PATCH, DELETE, ...)
  2. Determine if the HTTP Content-Type header has been transmitted.
  3. Determine if the value for the Content-Type is the desired media type.

Part II: Stream Data Related

  1. Determine the size of the input stream (optional, but recommended).
  2. Determine the encoding of the input stream.
  3. If necessary, convert the input stream to the desired character encoding (UTF-8).
  4. If necessary, reverse any application level compression or encryption, and then repeat steps 4, 5, and 6.

Part III: Data Type Related

  1. Determine if the data sent is well formed XML / JSON / YMAL / etc.

(Remember, the data can still be a URL encoded string which you must then parse and URL decode).

  1. If necessary, convert the data to a PHP datatype: array or object.

Part IV: Data Value Related

  1. Filter input data.

  2. Validate input data.

Now do you see?

The $_POST superglobal, along with php.ini settings for limits on input, are simpler for the layman. However, dealing with character encoding is much more intuitive and efficient when using streams because there is no need to loop through superglobals (or arrays, generally) to check input values for the proper encoding.

How do I base64 encode (decode) in C?

Here's the one I'm using:

#include <stdint.h>
#include <stdlib.h>


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


char *base64_encode(const unsigned char *data,
                    size_t input_length,
                    size_t *output_length) {

    *output_length = 4 * ((input_length + 2) / 3);

    char *encoded_data = malloc(*output_length);
    if (encoded_data == NULL) return NULL;

    for (int i = 0, j = 0; i < input_length;) {

        uint32_t octet_a = i < input_length ? (unsigned char)data[i++] : 0;
        uint32_t octet_b = i < input_length ? (unsigned char)data[i++] : 0;
        uint32_t octet_c = i < input_length ? (unsigned char)data[i++] : 0;

        uint32_t triple = (octet_a << 0x10) + (octet_b << 0x08) + octet_c;

        encoded_data[j++] = encoding_table[(triple >> 3 * 6) & 0x3F];
        encoded_data[j++] = encoding_table[(triple >> 2 * 6) & 0x3F];
        encoded_data[j++] = encoding_table[(triple >> 1 * 6) & 0x3F];
        encoded_data[j++] = encoding_table[(triple >> 0 * 6) & 0x3F];
    }

    for (int i = 0; i < mod_table[input_length % 3]; i++)
        encoded_data[*output_length - 1 - i] = '=';

    return encoded_data;
}


unsigned char *base64_decode(const char *data,
                             size_t input_length,
                             size_t *output_length) {

    if (decoding_table == NULL) build_decoding_table();

    if (input_length % 4 != 0) return NULL;

    *output_length = input_length / 4 * 3;
    if (data[input_length - 1] == '=') (*output_length)--;
    if (data[input_length - 2] == '=') (*output_length)--;

    unsigned char *decoded_data = malloc(*output_length);
    if (decoded_data == NULL) return NULL;

    for (int i = 0, j = 0; i < input_length;) {

        uint32_t sextet_a = data[i] == '=' ? 0 & i++ : decoding_table[data[i++]];
        uint32_t sextet_b = data[i] == '=' ? 0 & i++ : decoding_table[data[i++]];
        uint32_t sextet_c = data[i] == '=' ? 0 & i++ : decoding_table[data[i++]];
        uint32_t sextet_d = data[i] == '=' ? 0 & i++ : decoding_table[data[i++]];

        uint32_t triple = (sextet_a << 3 * 6)
        + (sextet_b << 2 * 6)
        + (sextet_c << 1 * 6)
        + (sextet_d << 0 * 6);

        if (j < *output_length) decoded_data[j++] = (triple >> 2 * 8) & 0xFF;
        if (j < *output_length) decoded_data[j++] = (triple >> 1 * 8) & 0xFF;
        if (j < *output_length) decoded_data[j++] = (triple >> 0 * 8) & 0xFF;
    }

    return decoded_data;
}


void build_decoding_table() {

    decoding_table = malloc(256);

    for (int i = 0; i < 64; i++)
        decoding_table[(unsigned char) encoding_table[i]] = i;
}


void base64_cleanup() {
    free(decoding_table);
}

Keep in mind that this doesn't do any error-checking while decoding - non base 64 encoded data will get processed.

right align an image using CSS HTML

To make the image move right:

float: right;

To make the text not wrapped:

clear: right;

For best practice, put the css code in your stylesheets file. Once you add more code, it will look messy and hard to edit.

Get protocol, domain, and port from URL

Simple answer that works for all browsers:

let origin;

if (!window.location.origin) {
  origin = window.location.protocol + "//" + window.location.hostname + 
     (window.location.port ? ':' + window.location.port: '');
}

origin = window.location.origin;

Difference between BYTE and CHAR in column datatypes

Let us assume the database character set is UTF-8, which is the recommended setting in recent versions of Oracle. In this case, some characters take more than 1 byte to store in the database.

If you define the field as VARCHAR2(11 BYTE), Oracle can use up to 11 bytes for storage, but you may not actually be able to store 11 characters in the field, because some of them take more than one byte to store, e.g. non-English characters.

By defining the field as VARCHAR2(11 CHAR) you tell Oracle it can use enough space to store 11 characters, no matter how many bytes it takes to store each one. A single character may require up to 4 bytes.

Java code To convert byte to Hexadecimal

I am posting because none of the existing answers explain why their approaches work, which I think is really important for this problem. In some cases, this causes the proposed solution to appear unnecessarily complicated and subtle. To illustrate I will provide a fairly straightforward approach, but I'll provide a bit more detail to help illustrate why it works.

First off, what are we trying to do? We want to convert a byte value (or an array of bytes) to a string which represents a hexadecimal value in ASCII. So step one is to find out exactly what a byte in Java is:

The byte data type is an 8-bit signed two's complement integer. It has a minimum value of -128 and a maximum value of 127 (inclusive). The byte data type can be useful for saving memory in large arrays, where the memory savings actually matters. They can also be used in place of int where their limits help to clarify your code; the fact that a variable's range is limited can serve as a form of documentation.

What does this mean? A few things: First and most importantly, it means we are working with 8-bits. So for example we can write the number 2 as 0000 0010. However, since it is two's complement, we write a negative 2 like this: 1111 1110. What is also means is that converting to hex is very straightforward. That is, you simply convert each 4 bit segment directly to hex. Note that to make sense of negative numbers in this scheme you will first need to understand two's complement. If you don't already understand two's complement, you can read an excellent explanation, here: http://www.cs.cornell.edu/~tomf/notes/cps104/twoscomp.html


Converting Two's Complement to Hex In General

Once a number is in two's complement it is dead simple to convert it to hex. In general, converting from binary to hex is very straightforward, and as you will see in the next two examples, you can go directly from two's complement to hex.

Examples

Example 1: Convert 2 to Hex.

1) First convert 2 to binary in two's complement:

2 (base 10) = 0000 0010 (base 2)

2) Now convert binary to hex:

0000 = 0x0 in hex
0010 = 0x2 in hex

therefore 2 = 0000 0010 = 0x02. 

Example 2: Convert -2 (in two's complement) to Hex.

1) First convert -2 to binary in two's complement:

-2 (base 10) = 0000 0010 (direct conversion to binary) 
               1111 1101 (invert bits)
               1111 1110 (add 1)
therefore: -2 = 1111 1110 (in two's complement)

2) Now Convert to Hex:

1111 = 0xF in hex
1110 = 0xE in hex

therefore: -2 = 1111 1110 = 0xFE.


Doing this In Java

Now that we've covered the concept, you'll find we can achieve what we want with some simple masking and shifting. The key thing to understand is that the byte you are trying to convert is already in two's complement. You don't do this conversion yourself. I think this is a major point of confusion on this issue. Take for example the follow byte array:

byte[] bytes = new byte[]{-2,2};

We just manually converted them to hex, above, but how can we do it in Java? Here's how:

Step 1: Create a StringBuffer to hold our computation.

StringBuffer buffer = new StringBuffer();

Step 2: Isolate the higher order bits, convert them to hex, and append them to the buffer

Given the binary number 1111 1110, we can isolate the higher order bits by first shifting them over by 4, and then zeroing out the rest of the number. Logically this is simple, however, the implementation details in Java (and many languages) introduce a wrinkle because of sign extension. Essentially, when you shift a byte value, Java first converts your value to an integer, and then performs sign extension. So while you would expect 1111 1110 >> 4 to be 0000 1111, in reality, in Java it is represented as the two's complement 0xFFFFFFFF!

So returning to our example:

1111 1110 >> 4 (shift right 4) = 1111 1111 1111 1111 1111 1111 1111 1111 (32 bit sign-extended number in two's complement)

We can then isolate the bits with a mask:

1111 1111 1111 1111 1111 1111 1111 1111 & 0xF = 0000 0000 0000 0000 0000 0000 0000 1111
therefore: 1111 = 0xF in hex. 

In Java we can do this all in one shot:

Character.forDigit((bytes[0] >> 4) & 0xF, 16);

The forDigit function just maps the number you pass it onto the set of hexadecimal numbers 0-F.

Step 3: Next we need to isolate the lower order bits. Since the bits we want are already in the correct position, we can just mask them out:

1111 1110 & 0xF = 0000 0000 0000 0000 0000 0000 0000 1110 (recall sign extension from before)
therefore: 1110 = 0xE in hex.  

Like before, in Java we can do this all in one shot:

Character.forDigit((bytes[0] & 0xF), 16);

Putting this all together we can do it as a for loop and convert the entire array:

for(int i=0; i < bytes.length; i++){
    buffer.append(Character.forDigit((bytes[i] >> 4) & 0xF, 16));
    buffer.append(Character.forDigit((bytes[i] & 0xF), 16));
}

Hopefully this explanation makes things clearer for those of you wondering exactly what is going on in the many examples you will find on the internet. Hopefully I didn't make any egregious errors, but suggestions and corrections are highly welcome!

Image change every 30 seconds - loop

setInterval function is the one that has to be used. Here is an example for the same without any fancy fading option. Simple Javascript that does an image change every 30 seconds. I have assumed that the images were kept in a separate images folder and hence _images/ is present at the beginning of every image. You can have your own path as required to be set.

CODE:

var im = document.getElementById("img");

var images = ["_images/image1.jpg","_images/image2.jpg","_images/image3.jpg"];
var index=0;

function changeImage()
{
  im.setAttribute("src", images[index]);
  index++;
  if(index >= images.length)
  {
    index=0;
  }
}

setInterval(changeImage, 30000);

What does "Failure [INSTALL_FAILED_OLDER_SDK]" mean in Android Studio?

Make Sure the Select Run/Debug Configuration is wear or mobile as per your installation in android studio...

using extern template (C++11)

If you have used extern for functions before, exactly same philosophy is followed for templates. if not, going though extern for simple functions may help. Also, you may want to put the extern(s) in header file and include the header when you need it.

AngularJS directive does not update on scope variable changes

I've found a much better solution:

app.directive('layout', function(){
    var settings = {
        restrict: 'E',
        transclude: true,
        templateUrl: function(element, attributes){
            var layoutName = (angular.isDefined(attributes.name)) ? attributes.name : 'Default';
            return constants.pathLayouts + layoutName + '.html';
        }
    }
    return settings;
});

The only disadvantage I see currently, is the fact that transcluded templates got their own scope. They get the values from their parents, but instead of change the value in the parent, the value get stored in an own, new child-scope. To avoid this, I am now using $parent.whatever instead of whatever.

Example:

<layout name="Default">
    <layout name="AnotherNestedLayout">
        <label>Whatever:</label>
        <input type="text" ng-model="$parent.whatever">
    </layout>
</layout>

Resizing an iframe based on content

This is slightly tricky as you have to know when the iframe page has loaded, which is difficuly when you're not in control of its content. Its possible to add an onload handler to the iframe, but I've tried this in the past and it has vastly different behaviour across browsers (not guess who's the most annoying...). You'd probably have to add a function to the iframe page that performs the resize and inject some script into the content that either listens to load events or resize events, which then calls the previous function. I'm thinking add a function to the page since you want to make sure its secure, but I have no idea how easy it will be to do.

Problems with local variable scope. How to solve it?

You have a scope problem indeed, because statement is a local method variable defined here:

protected void createContents() {
    ...
    Statement statement = null; // local variable
    ...
     btnInsert.addMouseListener(new MouseAdapter() { // anonymous inner class
        @Override
        public void mouseDown(MouseEvent e) {
            ...
            try {
                statement.executeUpdate(query); // local variable out of scope here
            } catch (SQLException e1) {
                e1.printStackTrace();
            }
            ...
    });
}

When you try to access this variable inside mouseDown() method you are trying to access a local variable from within an anonymous inner class and the scope is not enough. So it definitely must be final (which given your code is not possible) or declared as a class member so the inner class can access this statement variable.

Sources:


How to solve it?

You could...

Make statement a class member instead of a local variable:

public class A1 { // Note Java Code Convention, also class name should be meaningful   
    private Statement statement;
    ...
}

You could...

Define another final variable and use this one instead, as suggested by @HotLicks:

protected void createContents() {
    ...
    Statement statement = null;
    try {
        statement = connect.createStatement();
        final Statement innerStatement = statement;
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    ...
}

But you should...

Reconsider your approach. If statement variable won't be used until btnInsert button is pressed then it doesn't make sense to create a connection before this actually happens. You could use all local variables like this:

btnInsert.addMouseListener(new MouseAdapter() {
   @Override
   public void mouseDown(MouseEvent e) {
       try {
           Class.forName("com.mysql.jdbc.Driver");
           try (Connection connect = DriverManager.getConnection(...);
                Statement statement = connect.createStatement()) {

                // execute the statement here

           } catch (SQLException ex) {
               ex.printStackTrace();
           }

       } catch (ClassNotFoundException ex) {
           e.printStackTrace();
       }
});

bootstrap datepicker today as default

If none of the above option work, use the following :

$(".datepicker").datepicker();
$(".datepicker").datepicker("setDate", new Date());

This worked for me.

How to add new contacts in android

There are several good articles on the subject on dev2qa.com site, about Contacts Provider API:

How To Add Contact In Android Programmatically

How To Update Delete Android Contacts Programmatically

How To Get Contact List In Android Programmatically

Contacts are stored in SQLite .db files in bunch of tables, the structure is discussed here: Android Contacts Database Structure

Official Google documentation on Contacts Provider here

What does principal end of an association means in 1:1 relationship in Entity framework

In one-to-one relation one end must be principal and second end must be dependent. Principal end is the one which will be inserted first and which can exist without the dependent one. Dependent end is the one which must be inserted after the principal because it has foreign key to the principal.

In case of entity framework FK in dependent must also be its PK so in your case you should use:

public class Boo
{
    [Key, ForeignKey("Foo")]
    public string BooId{get;set;}
    public Foo Foo{get;set;}
}

Or fluent mapping

modelBuilder.Entity<Foo>()
            .HasOptional(f => f.Boo)
            .WithRequired(s => s.Foo);

How to find path of active app.config file?

Make sure you click the properties on the file and set it to "copy always" or it will not be in the Debug\ folder with your happy lil dll's to configure where it needs to be and add more cowbell

assign multiple variables to the same value in Javascript

The original variables you listed can be declared and assigned to the same value in a short line of code using destructuring assignment. The keywords let, const, and var can all be used for this type of assignment.

let [moveUp, moveDown, moveLeft, moveRight, mouseDown, touchDown] = Array(6).fill(false);

Return list using select new in LINQ

What is being returned is an anonymous type so create a new class with 2 fields

class BasicProjectInfo {
   string name;
   string id;
}

and return new BasicProjectInfo(pro.ProjectName, pro.ProjectId);. You method in this case will return a List<BasicProjectInfo>

Change the image source on rollover using jQuery

Adapted from Richard Ayotte's code - To target an img in a ul/li list (found via wrapper div class here), something like this:

$('div.navlist li').bind('mouseenter mouseleave', function() {    
    $(this).find('img').attr({ src: $(this).find('img').attr('data-alt-src'), 
    'data-alt-src':$(this).find('img').attr('src') }
); 

Javascript equivalent of php's strtotime()?

Check out this implementation of PHP's strtotime() in JavaScript!

I found that it works identically to PHP for everything that I threw at it.

Update: this function as per version 1.0.2 can't handle this case: '2007:07:20 20:52:45' (Note the : separator for year and month)

Update 2018:

This is now available as an npm module! Simply npm install locutus and then in your source:

var strtotime = require('locutus/php/datetime/strtotime');

passing argument to DialogFragment

In my case, none of the code above with bundle-operate works; Here is my decision (I don't know if it is proper code or not, but it works in my case):

public class DialogMessageType extends DialogFragment {
    private static String bodyText;

    public static DialogMessageType addSomeString(String temp){
        DialogMessageType f = new DialogMessageType();
        bodyText = temp;
        return f;
    };

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        final String[] choiseArray = {"sms", "email"};
        String title = "Send text via:";
        final AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        builder.setTitle(title).setItems(choiseArray, itemClickListener);
        builder.setCancelable(true);
        return builder.create();
    }

    DialogInterface.OnClickListener itemClickListener = new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            switch (which){
                case 0:
                    prepareToSendCoordsViaSMS(bodyText);
                    dialog.dismiss();
                    break;
                case 1:
                    prepareToSendCoordsViaEmail(bodyText);
                    dialog.dismiss();
                    break;
                default:
                    break;
            }
        }
    };
[...]
}

public class SendObjectActivity extends FragmentActivity {
[...]

DialogMessageType dialogMessageType = DialogMessageType.addSomeString(stringToSend);
dialogMessageType.show(getSupportFragmentManager(),"dialogMessageType");

[...]
}

Add querystring parameters to link_to

If you want the quick and dirty way and don't worry about XSS attack, use params.merge to keep previous parameters. e.g.

<%= link_to 'Link', params.merge({:per_page => 20}) %>

see: https://stackoverflow.com/a/4174493/445908

Otherwise , check this answer: params.merge and cross site scripting

How to use registerReceiver method?

The whole code if somebody need it.

void alarm(Context context, Calendar calendar) {
    AlarmManager alarmManager = (AlarmManager)context.getSystemService(ALARM_SERVICE);

    final String SOME_ACTION = "com.android.mytabs.MytabsActivity.AlarmReceiver";
    IntentFilter intentFilter = new IntentFilter(SOME_ACTION);

    AlarmReceiver mReceiver = new AlarmReceiver();
    context.registerReceiver(mReceiver, intentFilter);

    Intent anotherIntent = new Intent(SOME_ACTION);
    PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, anotherIntent, 0);
    alramManager.set(AlarmManager.RTC_WAKEUP, calendar.getTimeInMillis(), pendingIntent);

    Toast.makeText(context, "Added", Toast.LENGTH_LONG).show();
}

class AlarmReceiver extends BroadcastReceiver {     
    @Override
    public void onReceive(Context context, Intent arg1) {
        Toast.makeText(context, "Started", Toast.LENGTH_LONG).show();
    }
}

How to count the number of files in a directory using Python

This is an easy solution that counts the number of files in a directory containing sub-folders. It may come in handy;

import os
from pathlib import Path

def count_files(rootdir):
    '''counts the number of files in each subfolder in a directory'''
    for path in pathlib.Path(rootdir).iterdir():
        if path.is_dir():
            print("There are " + str(len([name for name in os.listdir(path) \
            if os.path.isfile(os.path.join(path, name))])) + " files in " + \
            str(path.name))
            
 
count_files(data_dir) # data_dir is the directory you want files counted.

You should get an output similar to this (with the placeholders changed, of course);

There are {number of files} files in {name of sub-folder1}
There are {number of files} files in {name of sub-folder2}

How to delete columns in pyspark dataframe

Maybe a little bit off topic, but here is the solution using Scala. Make an Array of column names from your oldDataFrame and delete the columns that you want to drop ("colExclude"). Then pass the Array[Column] to select and unpack it.

val columnsToKeep: Array[Column] = oldDataFrame.columns.diff(Array("colExclude"))
                                               .map(x => oldDataFrame.col(x))
val newDataFrame: DataFrame = oldDataFrame.select(columnsToKeep: _*)

Populate one dropdown based on selection in another

Could you please have a look at: http://jsfiddle.net/4Zw3M/1/.

Basically, the data is stored in an Array and the options are added accordingly. I think the code says more than a thousand words.

var data = [ // The data
    ['ten', [
        'eleven','twelve'
    ]],
    ['twenty', [
        'twentyone', 'twentytwo'
    ]]
];

$a = $('#a'); // The dropdowns
$b = $('#b');

for(var i = 0; i < data.length; i++) {
    var first = data[i][0];
    $a.append($("<option>"). // Add options
       attr("value",first).
       data("sel", i).
       text(first));
}

$a.change(function() {
    var index = $(this).children('option:selected').data('sel');
    var second = data[index][1]; // The second-choice data

    $b.html(''); // Clear existing options in second dropdown

    for(var j = 0; j < second.length; j++) {
        $b.append($("<option>"). // Add options
           attr("value",second[j]).
           data("sel", j).
           text(second[j]));
    }
}).change(); // Trigger once to add options at load of first choice

PySpark: withColumn() with two conditions and three outcomes

You'll want to use a udf as below

from pyspark.sql.types import IntegerType
from pyspark.sql.functions import udf

def func(fruit1, fruit2):
    if fruit1 == None or fruit2 == None:
        return 3
    if fruit1 == fruit2:
        return 1
    return 0

func_udf = udf(func, IntegerType())
df = df.withColumn('new_column',func_udf(df['fruit1'], df['fruit2']))

How do I make case-insensitive queries on Mongodb?

... with mongoose on NodeJS that query:

const countryName = req.params.country;

{ 'country': new RegExp(`^${countryName}$`, 'i') };

or

const countryName = req.params.country;

{ 'country': { $regex: new RegExp(`^${countryName}$`), $options: 'i' } };

// ^australia$

or

const countryName = req.params.country;

{ 'country': { $regex: new RegExp(`^${countryName}$`, 'i') } };

// ^turkey$

A full code example in Javascript, NodeJS with Mongoose ORM on MongoDB

// get all customers that given country name
app.get('/customers/country/:countryName', (req, res) => {
    //res.send(`Got a GET request at /customer/country/${req.params.countryName}`);

    const countryName = req.params.countryName;

    // using Regular Expression (case intensitive and equal): ^australia$

    // const query = { 'country': new RegExp(`^${countryName}$`, 'i') };
    // const query = { 'country': { $regex: new RegExp(`^${countryName}$`, 'i') } };
    const query = { 'country': { $regex: new RegExp(`^${countryName}$`), $options: 'i' } };

    Customer.find(query).sort({ name: 'asc' })
        .then(customers => {
            res.json(customers);
        })
        .catch(error => {
            // error..
            res.send(error.message);
        });
});

How to get HTTP Response Code using Selenium WebDriver

You could try Mobilenium (https://github.com/rafpyprog/Mobilenium), a python package that binds BrowserMob Proxy and Selenium.

An usage example:

>>> from mobilenium import mobidriver
>>>
>>> browsermob_path = 'path/to/browsermob-proxy'
>>> mob = mobidriver.Firefox(browsermob_binary=browsermob_path)
>>> mob.get('http://python-requests.org')
301
>>> mob.response['redirectURL']
'http://docs.python-requests.org'
>>> mob.headers['Content-Type']
'application/json; charset=utf8'
>>> mob.title
'Requests: HTTP for Humans \u2014 Requests 2.13.0 documentation'
>>> mob.find_elements_by_tag_name('strong')[1].text
'Behold, the power of Requests'

Extracting text OpenCV

You can try this method that is developed by Chucai Yi and Yingli Tian.

They also share a software (which is based on Opencv-1.0 and it should run under Windows platform.) that you can use (though no source code available). It will generate all the text bounding boxes (shown in color shadows) in the image. By applying to your sample images, you will get the following results:

Note: to make the result more robust, you can further merge adjacent boxes together.


Update: If your ultimate goal is to recognize the texts in the image, you can further check out gttext, which is an OCR free software and Ground Truthing tool for Color Images with Text. Source code is also available.

With this, you can get recognized texts like:

How to make a floated div 100% height of its parent?

For the parent:

display: flex;

You should add some prefixes http://css-tricks.com/using-flexbox/

Edit: Only drawback is IE as usual, IE9 does not support flex. http://caniuse.com/flexbox

Edit 2: As @toddsby noted, align items is for parent, and its default value actually is stretch. If you want a different value for child, there is align-self property.

Edit 3: jsFiddle: https://jsfiddle.net/bv71tms5/2/

SQL Server: Best way to concatenate multiple columns?

SELECT CONCAT(LOWER(LAST_NAME), UPPER(LAST_NAME)
       INITCAP(LAST_NAME), HIRE DATE AS ‘up_low_init_hdate’)
FROM EMPLOYEES
WHERE HIRE DATE = 1995

Best Free Text Editor Supporting *More Than* 4GB Files?

What OS and CPU are you using? If you are using a 32-bit OS, then a process on your system physically cannot address more than 4GB of memory. Since most text editors try to load the entire file into memory, I doubt you'll find one that will do what you want. It would have to be a very fancy text editor, that can do out-of-core processing, i. e. load a chunk of the file at a time.

You may be able to load such a huge file with if you use a 64-bit text editor on a computer with a 64-bit CPU and a 64-bit operating system. And you have to make sure that you have enough space in your swap partition or your swap file.

How to efficiently count the number of keys/properties of an object in JavaScript?

From: https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Object/defineProperty

Object.defineProperty(obj, prop, descriptor)

You can either add it to all your objects:

Object.defineProperty(Object.prototype, "length", {
    enumerable: false,
    get: function() {
        return Object.keys(this).length;
    }
});

Or a single object:

var myObj = {};
Object.defineProperty(myObj, "length", {
    enumerable: false,
    get: function() {
        return Object.keys(this).length;
    }
});

Example:

var myObj = {};
myObj.name  = "John Doe";
myObj.email = "[email protected]";
myObj.length; //output: 2

Added that way, it won't be displayed in for..in loops:

for(var i in myObj) {
     console.log(i + ":" + myObj[i]);
}

Output:

name:John Doe
email:[email protected]

Note: it does not work in < IE9 browsers.

Adding a new SQL column with a default value

Try this:

ALTER TABLE table1 ADD COLUMN foo INT DEFAULT 0;

From the documentation that you linked to:

ALTER [ONLINE | OFFLINE] [IGNORE] TABLE tbl_name
   alter_specification [, alter_specification] ...

alter_specification:
    ...
    ADD [COLUMN] (col_name column_definition,...)
    ...

To find the syntax for column_definition search a bit further down the page:

column_definition clauses use the same syntax for ADD and CHANGE as for CREATE TABLE. See Section 12.1.17, “CREATE TABLE Syntax”.

And from the linked page:

column_definition:  
   data_type [NOT NULL | NULL] [DEFAULT default_value]
   [AUTO_INCREMENT] [UNIQUE [KEY] | [PRIMARY] KEY]  
   [COMMENT 'string']  
   [COLUMN_FORMAT {FIXED|DYNAMIC|DEFAULT}]  
   [STORAGE {DISK|MEMORY|DEFAULT}]  
   [reference_definition]  

Notice the word DEFAULT there.

how to convert a string date to date format in oracle10g

You can convert a string to a DATE using the TO_DATE function, then reformat the date as another string using TO_CHAR, i.e.:

SELECT TO_CHAR(
         TO_DATE('15/August/2009,4:30 PM'
                ,'DD/Month/YYYY,HH:MI AM')
       ,'DD-MM-YYYY')
FROM DUAL;

15-08-2009

For example, if your table name is MYTABLE and the varchar2 column is MYDATESTRING:

SELECT TO_CHAR(
         TO_DATE(MYDATESTRING
                ,'DD/Month/YYYY,HH:MI AM')
       ,'DD-MM-YYYY')
FROM MYTABLE;

Remove unused imports in Android Studio

there is also an Android Studio (1.4) setting to optimze imports on the fly: see Settings->Editor->General->Auto Import.

Giving a border to an HTML table row, <tr>

Make use of CSS classes:

tr.border{
    outline: thin solid;
}

and use it like:

<tr class="border">...</tr>

React Native TextInput that only accepts numeric characters

I wrote this function which I found to be helpful to prevent the user from being able to enter anything other than I was willing to accept. I also used keyboardType="decimal-pad" and my onChangeText={this.decimalTextChange}

  decimalTextChange = (distance) =>
{
    let decimalRegEx = new RegExp(/^\d*\.?\d*$/)
    if (distance.length === 0 || distance === "." || distance[distance.length - 1] === "."
        && decimalRegEx.test(distance)
    ) {
        this.setState({ distance })
    } else {
        const distanceRegEx = new RegExp(/^\s*-?(\d+(\.\d{ 1, 2 })?|\.\d{ 1, 2 })\s*$/)
        if (distanceRegEx.test(distance)) this.setState({ distance })
    }
}

The first if block is error handling for the event the user deletes all of the text, or uses a decimal point as the first character, or if they attempt to put in more than one decimal place, the second if block makes sure they can type in as many numbers as they want before the decimal place, but only up to two decimal places after the point.

How can I express that two values are not equal to eachother?

"Not equals" can be expressed with the "not" operator ! and the standard .equals.

if (a.equals(b)) // a equals b
if (!a.equals(b)) // a not equal to b

How to implement a queue using two stacks?

Let queue to be implemented be q and stacks used to implement q be stack1 and stack2.

q can be implemented in two ways:

Method 1 (By making enQueue operation costly)

This method makes sure that newly entered element is always at the top of stack 1, so that deQueue operation just pops from stack1. To put the element at top of stack1, stack2 is used.

enQueue(q, x)
1) While stack1 is not empty, push everything from stack1 to stack2.
2) Push x to stack1 (assuming size of stacks is unlimited).
3) Push everything back to stack1.
deQueue(q)
1) If stack1 is empty then error
2) Pop an item from stack1 and return it.

Method 2 (By making deQueue operation costly)

In this method, in en-queue operation, the new element is entered at the top of stack1. In de-queue operation, if stack2 is empty then all the elements are moved to stack2 and finally top of stack2 is returned.

enQueue(q,  x)
 1) Push x to stack1 (assuming size of stacks is unlimited).

deQueue(q)
 1) If both stacks are empty then error.
 2) If stack2 is empty
   While stack1 is not empty, push everything from stack1 to stack2.
 3) Pop the element from stack2 and return it.

Method 2 is definitely better than method 1. Method 1 moves all the elements twice in enQueue operation, while method 2 (in deQueue operation) moves the elements once and moves elements only if stack2 empty.

C# Dictionary get item by index

Your key is a string and your value is an int. Your code won't work because it cannot look up the random int you pass. Also, please provide full code

How to generate a random number between 0 and 1?

Have you tried with: replacing ((rand() % 10000) / 10000.0), with:(rand() % 2). This worked for me!

So you could do something like this:

double r2()
{
     srand(time(NULL));
     return(rand() % 2);
}

How to check if a radiobutton is checked in a radiogroup in Android?

Use the isChecked() function for every radioButton you have to check.

RadioButton maleRadioButton, femaleRadioButton;

maleRadioButton = (RadioButton) findViewById(R.id.maleRadioButton);
femaleRadioButton = (RadioButton) findViewById(R.id.femaleRadioButton);

Then use the result for your if/else case consideration.

if (maleRadioButton.isChecked() || femaleRadioButton.isChecked()) {
     Log.d("QAOD", "Gender is Selected");
} else {
    Toast.makeText(getApplicationContext(), "Please select Gender", Toast.LENGTH_SHORT).show();
    Log.d("QAOD", "Gender is Null");
}

check all socket opened in linux OS

You can use netstat command

netstat --listen

To display open ports and established TCP connections,

netstat -vatn

To display only open UDP ports try the following command:

netstat -vaun

React.js: Identifying different inputs with one onChange handler

You can use the .bind method to pre-build the parameters to the handleChange method. It would be something like:

  var Hello = React.createClass({
    getInitialState: function() {
        return {input1:0, 
                input2:0};
    },
    render: function() {
      var total = this.state.input1 + this.state.input2;
      return (
        <div>{total}<br/>
          <input type="text" value={this.state.input1} 
                             onChange={this.handleChange.bind(this, 'input1')} />
          <input type="text" value={this.state.input2} 
                             onChange={this.handleChange.bind(this, 'input2')} />
        </div>
      );
    },
    handleChange: function (name, e) {
      var change = {};
      change[name] = e.target.value;
      this.setState(change);
    }
  });

  React.renderComponent(<Hello />, document.getElementById('content'));

(I also made total be computed at render time, as it is the recommended thing to do.)

'Missing recommended icon file - The bundle does not contain an app icon for iPhone / iPod Touch of exactly '120x120' pixels, in .png format'

In my case it was linked with CocoaPods. I've spent a bunch of time to find what was the reason, cause everything seemed correct. I found it over here https://github.com/CocoaPods/CocoaPods/issues/7003. I just moved the "[CP] Copy Pods Resources" and "[CP] Embed Pods Frameworks" above "Copy Bundle Resources" in the Build Phases and the error dissapeared.

How to select a directory and store the location using tkinter in Python

This code may be helpful for you.

from tkinter import filedialog
from tkinter import *
root = Tk()
root.withdraw()
folder_selected = filedialog.askdirectory()

File Upload ASP.NET MVC 3.0

Html:

@using (Html.BeginForm("StoreMyCompany", "MyCompany", FormMethod.Post, new { id = "formMyCompany", enctype = "multipart/form-data" }))
{
   <div class="form-group">
      @Html.LabelFor(model => model.modelMyCompany.Logo, htmlAttributes: new { @class = "control-label col-md-3" })
      <div class="col-md-6">
        <input type="file" name="Logo" id="fileUpload" accept=".png,.jpg,.jpeg,.gif,.tif" />
      </div>
    </div>

    <br />
    <div class="form-group">
          <div class="col-md-offset-3 col-md-6">
              <input type="submit" value="Save" class="btn btn-success" />
          </div>
     </div>
}  

Code Behind:

public ActionResult StoreMyCompany([Bind(Exclude = "Logo")]MyCompanyVM model)
{
    try
    {        
        byte[] imageData = null;
        if (Request.Files.Count > 0)
        {
            HttpPostedFileBase objFiles = Request.Files["Logo"];

            using (var binaryReader = new BinaryReader(objFiles.InputStream))
            {
                imageData = binaryReader.ReadBytes(objFiles.ContentLength);
            }
        }

        if (imageData != null && imageData.Length > 0)
        {
           //Your code
        }

        dbo.SaveChanges();

        return RedirectToAction("MyCompany", "Home");

    }
    catch (Exception ex)
    {
        Utility.LogError(ex);
    }

    return View();
}

How to output in CLI during execution of PHP Unit tests?

Try using --debug

Useful if you're trying to get the right path to an include or source data file.

Scrollview vertical and horizontal in android

Option #1: You can come up with a new UI design that does not require simultaneous horizontal and vertical scrolling.

Option #2: You can obtain the source code to ScrollView and HorizontalScrollView, learn how the core Android team implemented those, and create your own BiDirectionalScrollView implementation.

Option #3: You can get rid of the dependencies that are requiring you to use the widget system and draw straight to the Canvas.

Option #4: If you stumble upon an open source application that seems to implement what you seek, look to see how they did it.

how to open a page in new tab on button click in asp.net?

Just had the same problem. Client-side wasn't appropriate because the button was posting back information from a listview.

Saw same solution as Amaranth's on way2coding but this didn't work for me.

However, in the comments, someone posted a similar solution that does work

OnClientClick="document.getElementById('form1').target ='_blank';"

where form1 is the id of your asp.net form.

SQL Server 2008 - Case / If statements in SELECT Clause

Simple CASE expression:

CASE input_expression 
     WHEN when_expression THEN result_expression [ ...n ] 
     [ ELSE else_result_expression ] 
END

Searched CASE expression:

CASE
     WHEN Boolean_expression THEN result_expression [ ...n ] 
     [ ELSE else_result_expression ] 
END

Reference: http://msdn.microsoft.com/en-us/library/ms181765.aspx

Difference between == and ===

In Swift we have === simbol which means is both objects are referring to the same reference same address

class SomeClass {
var a: Int;

init(_ a: Int) {
    self.a = a
}

}

var someClass1 = SomeClass(4)
var someClass2 = SomeClass(4)
someClass1 === someClass2 // false
someClass2 = someClass1
someClass1 === someClass2 // true

What is the difference between Serialization and Marshaling?

Think of them as synonyms, both have a producer that sends stuff over to a consumer... In the end fields of instances are written into a byte stream and the other end foes the reverse ands up with the same instances.

NB - java RMI also contains support for transporting classes that are missing from the recipient...

Can we pass model as a parameter in RedirectToAction?

Using TempData

Represents a set of data that persists only from one request to the next

[HttpPost]
public ActionResult FillStudent(Student student1)
{
    TempData["student"]= new Student();
    return RedirectToAction("GetStudent","Student");
}

[HttpGet]
public ActionResult GetStudent(Student passedStd)
{
    Student std=(Student)TempData["student"];
    return View();
}

Alternative way Pass the data using Query string

return RedirectToAction("GetStudent","Student", new {Name="John", Class="clsz"});

This will generate a GET Request like Student/GetStudent?Name=John & Class=clsz

Ensure the method you want to redirect to is decorated with [HttpGet] as the above RedirectToAction will issue GET Request with http status code 302 Found (common way of performing url redirect)

Hive Alter table change Column Name

Change Column Name/Type/Position/Comment:

ALTER TABLE table_name CHANGE [COLUMN] col_old_name col_new_name column_type [COMMENT col_comment] [FIRST|AFTER column_name]

Example:

CREATE TABLE test_change (a int, b int, c int);

// will change column a's name to a1
ALTER TABLE test_change CHANGE a a1 INT;

Pull request vs Merge request

GitLab's "merge request" feature is equivalent to GitHub's "pull request" feature. Both are means of pulling changes from another branch or fork into your branch and merging the changes with your existing code. They are useful tools for code review and change management.

An article from GitLab discusses the differences in naming the feature:

Merge or pull requests are created in a git management application and ask an assigned person to merge two branches. Tools such as GitHub and Bitbucket choose the name pull request since the first manual action would be to pull the feature branch. Tools such as GitLab and Gitorious choose the name merge request since that is the final action that is requested of the assignee. In this article we'll refer to them as merge requests.

A "merge request" should not be confused with the git merge command. Neither should a "pull request" be confused with the git pull command. Both git commands are used behind the scenes in both pull requests and merge requests, but a merge/pull request refers to a much broader topic than just these two commands.

Error when creating a new text file with python?

import sys

def write():
    print('Creating new text file') 

    name = raw_input('Enter name of text file: ')+'.txt'  # Name of text file coerced with +.txt

    try:
        file = open(name,'a')   # Trying to create a new file or open one
        file.close()

    except:
        print('Something went wrong! Can\'t tell what?')
        sys.exit(0) # quit Python

write()

this will work promise :)

How to add bootstrap to an angular-cli project

Just add these three lines in Head tag in index.html

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>

How to sort a Pandas DataFrame by index?

Dataframes have a sort_index method which returns a copy by default. Pass inplace=True to operate in place.

import pandas as pd
df = pd.DataFrame([1, 2, 3, 4, 5], index=[100, 29, 234, 1, 150], columns=['A'])
df.sort_index(inplace=True)
print(df.to_string())

Gives me:

     A
1    4
29   2
100  1
150  5
234  3

What is Bootstrap?

Bootstrap is an HTML, CSS, JS framework with many components that let you create beautiful and modern web sites or web applications very fast.

The following websites contain examples, elements and reusable components that you can integrate into your project using bootstrap framework

bootsnipp.com

startbootstrap.com

bootdey.com

How do I position an image at the bottom of div?

Using flexbox:

HTML:

<div class="wrapper">
    <img src="pikachu.gif"/>
</div>

CSS:

.wrapper {
    height: 300px;
    width: 300px;
    display: flex;
    align-items: flex-end;
}

As requested in some comments on another answer, the image can also be horizontally centred with justify-content: center;

Running a shell script through Cygwin on Windows

If you have access to the Notepad++ editor on Windows there is a feature that allows you to easily get around this problem:

  1. Open the file that's giving the error in Notepad++.
  2. Go under the "Edit" Menu and choose "EOL Conversion"
  3. There is an option there for "UNIX/OSX Format." Choose that option.
  4. Re-save the file.

I did this and it solved my problems.

Hope this helps!

Read more at http://danieladeniji.wordpress.com/2013/03/07/microsoft-windows-cygwin-error-r-command-not-found/

How to remove "href" with Jquery?

If you remove the href attribute the anchor will be not focusable and it will look like simple text, but it will still be clickable.

How to extract a substring using regex

You don't need regex for this.

Add apache commons lang to your project (http://commons.apache.org/proper/commons-lang/), then use:

String dataYouWant = StringUtils.substringBetween(mydata, "'");

Select elements by attribute

A couple ideas were tossed around using "typeof", jQuery ".is" and ".filter" so I thought I would post up a quick perf compare of them. The typeof appears to be the best choice for this. While the others will work, there appears to be a clear performance difference when invoking the jq library for this effort.

int to hex string

Try the following:

ToString("X4")

See The X format specifier on MSDN.

How to use WebRequest to POST some data and read response?

Here's what works for me. I'm sure it can be improved, so feel free to make suggestions or edit to make it better.

const string WEBSERVICE_URL = "http://localhost/projectname/ServiceName.svc/ServiceMethod";
//This string is untested, but I think it's ok.
string jsonData = "{ \"key1\" : \"value1\", \"key2\":\"value2\"  }"; 
try
{       
    var webRequest = System.Net.WebRequest.Create(WEBSERVICE_URL);
    if (webRequest != null)
    {
        webRequest.Method = "POST";
        webRequest.Timeout = 20000;
        webRequest.ContentType = "application/json";

    using (System.IO.Stream s = webRequest.GetRequestStream())
    {
        using (System.IO.StreamWriter sw = new System.IO.StreamWriter(s))
            sw.Write(jsonData);
    }

    using (System.IO.Stream s = webRequest.GetResponse().GetResponseStream())
    {
        using (System.IO.StreamReader sr = new System.IO.StreamReader(s))
        {
            var jsonResponse = sr.ReadToEnd();
            System.Diagnostics.Debug.WriteLine(String.Format("Response: {0}", jsonResponse));
        }
    }
}
}
catch (Exception ex)
{
    System.Diagnostics.Debug.WriteLine(ex.ToString());
}

Not able to install Python packages [SSL: TLSV1_ALERT_PROTOCOL_VERSION]

I ran into this problem as well. The underlying problem is that the ssl library in Python 2.7 versions < 2.7.9 is no longer compatible with the pip mechanism.

If you are running on Windows, and you (like us) can't easily upgrade from an incompatible version of 2.7, FWIW, I found that if you copy the following files from another install of the latest version of Python (e.g. Python 2.7.15) on another machine to your installation:

    Lib\ssl.py
    libs\_ssl.lib
    DLLs\_ssl.dll

it will effectively "upgrade" your SSL layer to one which is supported; we were then be able to use pip again, even to upgrade pip.

Using prepared statements with JDBCTemplate

I've tried a select statement now with a PreparedStatement, but it turned out that it was not faster than the Jdbc template. Maybe, as mezmo suggested, it automatically creates prepared statements.

Anyway, the reason for my sql SELECTs being so slow was another one. In the WHERE clause I always used the operator LIKE, when all I wanted to do was finding an exact match. As I've found out LIKE searches for a pattern and therefore is pretty slow.

I'm using the operator = now and it's much faster.

Oracle DB : java.sql.SQLException: Closed Connection

It means the connection was successfully established at some point, but when you tried to commit right there, the connection was no longer open. The parameters you mentioned sound like connection pool settings. If so, they're unrelated to this problem. The most likely cause is a firewall between you and the database that is killing connections after a certain amount of idle time. The most common fix is to make your connection pool run a validation query when a connection is checked out from it. This will immediately identify and evict dead connnections, ensuring that you only get good connections out of the pool.

In Linux, how to tell how much memory processes are using?

Use top or htop and pay attention to the "RES" (resident memory size) column.

css label width not taking effect

give the style

display:inline-block;

hope this will help'

Codeigniter $this->input->post() empty while $_POST is working correctly

Change your form action,

From this:

<form method="post" action="<?=base_url()?>yourprocess">

Into this:

<form method="post" action="<?=base_url()?>index.php/yourprocess">

Basically, you just need to add "index.php" after your base_url():

action="http://www.yourdomain.com/index.php/yourprocess"

How can you create multiple cursors in Visual Studio Code

On Ubuntu, in order to enable multi-cursor clicking you will need to re-assign Alt+click first, by running the command below. This is because by default Ubuntu uses the shortcut itself and has it takes precedence.

> gsettings set org.gnome.desktop.wm.preferences mouse-button-modifier "<Super>"

How to make a div center align in HTML

_x000D_
_x000D_
<!DOCTYPE html>_x000D_
<html>_x000D_
  <head>_x000D_
    <title>Center</title>_x000D_
  </head>_x000D_
  <body>_x000D_
_x000D_
    <div style="text-align: center;">_x000D_
      <div style="width: 500px; margin: 0 auto; background: #000; color: #fff;">This DIV is centered</div>_x000D_
    </div>_x000D_
_x000D_
  </body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Tested and worked in IE, Firefox, Chrome, Safari and Opera. I did not test IE6. The outer text-align is needed for IE. Other browsers (and IE9?) will work when you give the DIV margin (left and right) value of auto. Margin "0 auto" is a shorthand for margin "0 auto 0 auto" (top right bottom left).

Note: the text is also centered inside the inner DIV, if you want it to remain on the left side just specify text-align: left; for the inner DIV.

Edit: IE 6, 7, 8 and 9 running on the Standards Mode will work with margins set to auto.

Visual Studio Copy Project

I guess if this is something you do often, there's a little (non-free) utility that promises to do it for you: I haven't used it, so not sure how good it is:

http://www.kinook.com/CopyWiz/

There is also this project on CodePlex:

http://clone.codeplex.com/

I will probably give the codeplex project a try, and if it doesn't work I'll manually rename everything and edit the sln file.

How to resolve the error "Unable to access jarfile ApacheJMeter.jar errorlevel=1" while initiating Jmeter?

If you'll go through these steps:

  1. In the Terminal type brew install jmeter and hit Enter
  2. When it'll be done type jmeter and hit Enter again

You won't have to solve any kind of issue. Don't thank

How to generate random colors in matplotlib?

for X,Y in data:
   scatter(X, Y, c=numpy.random.rand(3,))

How to remove leading whitespace from each line in a file

For this specific problem, something like this would work:

$ sed 's/^ *//g' < input.txt > output.txt

It says to replace all spaces at the start of a line with nothing. If you also want to remove tabs, change it to this:

$ sed 's/^[ \t]+//g' < input.txt > output.txt

The leading "s" before the / means "substitute". The /'s are the delimiters for the patterns. The data between the first two /'s are the pattern to match, and the data between the second and third / is the data to replace it with. In this case you're replacing it with nothing. The "g" after the final slash means to do it "globally", ie: over the entire file rather than on only the first match it finds.

Finally, instead of < input.txt > output.txt you can use the -i option which means to edit the file "in place". Meaning, you don't need to create a second file to contain your result. If you use this option you will lose your original file.

MySQL select statement with CASE or IF ELSEIF? Not sure how to get the result

Another way of doing this is using nested IF statements. Suppose you have companies table and you want to count number of records in it. A sample query would be something like this

SELECT IF(
      count(*) > 15,
      'good',
      IF(
          count(*) > 10,
          'average',
          'poor'
        ) 
      ) as data_count 
      FROM companies

Here second IF condition works when the first IF condition fails. So Sample Syntax of the IF statement would be IF ( CONDITION, THEN, ELSE). Hope it helps someone.

MetadataException: Unable to load the specified metadata resource

For my case, it is solved by changing the properties of edmx file.

  1. Open the edmx file
  2. Right click on any place of the EDMX designer
  3. choose properties
  4. update Property called "Metadata Artifact Processing" to "Embed in Output Assembly"

this solved the problem for me. The problem is, when the container try to find the meta data, it cant find it. so simply make it in the same assembly. this solution will not work if you have your edmx files in another assembly

Deleting rows from parent and child tables

Two possible approaches.

  1. If you have a foreign key, declare it as on-delete-cascade and delete the parent rows older than 30 days. All the child rows will be deleted automatically.

  2. Based on your description, it looks like you know the parent rows that you want to delete and need to delete the corresponding child rows. Have you tried SQL like this?

      delete from child_table
          where parent_id in (
               select parent_id from parent_table
                    where updd_tms != (sysdate-30)
    

    -- now delete the parent table records

    delete from parent_table
    where updd_tms != (sysdate-30);
    

---- Based on your requirement, it looks like you might have to use PL/SQL. I'll see if someone can post a pure SQL solution to this (in which case that would definitely be the way to go).

declare
    v_sqlcode number;
    PRAGMA EXCEPTION_INIT(foreign_key_violated, -02291);
begin
    for v_rec in (select parent_id, child id from child_table
                         where updd_tms != (sysdate-30) ) loop

    -- delete the children
    delete from child_table where child_id = v_rec.child_id;

    -- delete the parent. If we get foreign key violation, 
    -- stop this step and continue the loop
    begin
       delete from parent_table
          where parent_id = v_rec.parent_id;
    exception
       when foreign_key_violated
         then null;
    end;
 end loop;
end;
/

How do you display JavaScript datetime in 12 hour AM/PM format?

Use Moment.js for this

Use below codes in JavaScript when using moment.js

H, HH       24 hour time
h, or hh    12 hour time (use in conjunction with a or A)

The format() method returns the date in specific format.

moment(new Date()).format("YYYY-MM-DD HH:mm"); // 24H clock
moment(new Date()).format("YYYY-MM-DD hh:mm A"); // 12H clock (AM/PM)
moment(new Date()).format("YYYY-MM-DD hh:mm a"); // 12H clock (am/pm)

How to add class active on specific li on user click with jQuery

You specified both jQuery and Javascript in the tags so here's both approaches.

jQuery

var selector = '.nav li';

$(selector).on('click', function(){
    $(selector).removeClass('active');
    $(this).addClass('active');
});

Fiddle: http://jsfiddle.net/bvf9u/


Pure Javascript:

var selector, elems, makeActive;

selector = '.nav li';

elems = document.querySelectorAll(selector);

makeActive = function () {
    for (var i = 0; i < elems.length; i++)
        elems[i].classList.remove('active');

    this.classList.add('active');
};

for (var i = 0; i < elems.length; i++)
    elems[i].addEventListener('mousedown', makeActive);

Fiddle: http://jsfiddle.net/rn3nc/1


jQuery with event delegation:

Please note that in approach 1, the handler is directly bound to that element. If you're expecting the DOM to update and new lis to be injected, it's better to use event delegation and delegate to the next element that will remain static, in this case the .nav:

$('.nav').on('click', 'li', function(){
    $('.nav li').removeClass('active');
    $(this).addClass('active');
});

Fiddle: http://jsfiddle.net/bvf9u/1/

The subtle difference is that the handler is bound to the .nav now, so when you click the li the event bubbles up the DOM to the .nav which invokes the handler if the element clicked matches your selector argument. This means new elements won't need a new handler bound to them, because it's already bound to an ancestor.

It's really quite interesting. Read more about it here: http://api.jquery.com/on/

How to use regex in String.contains() method in Java

String.contains

String.contains works with String, period. It doesn't work with regex. It will check whether the exact String specified appear in the current String or not.

Note that String.contains does not check for word boundary; it simply checks for substring.

Regex solution

Regex is more powerful than String.contains, since you can enforce word boundary on the keywords (among other things). This means you can search for the keywords as words, rather than just substrings.

Use String.matches with the following regex:

"(?s).*\\bstores\\b.*\\bstore\\b.*\\bproduct\\b.*"

The RAW regex (remove the escaping done in string literal - this is what you get when you print out the string above):

(?s).*\bstores\b.*\bstore\b.*\bproduct\b.*

The \b checks for word boundary, so that you don't get a match for restores store products. Note that stores 3store_product is also rejected, since digit and _ are considered part of a word, but I doubt this case appear in natural text.

Since word boundary is checked for both sides, the regex above will search for exact words. In other words, stores stores product will not match the regex above, since you are searching for the word store without s.

. normally match any character except a number of new line characters. (?s) at the beginning makes . matches any character without exception (thanks to Tim Pietzcker for pointing this out).

how to align img inside the div to the right?

<div style="width:300px; text-align:right;">
        <img src="someimgage.gif">
</div>

Best way to create a simple python web service

If you mean "web service" in SOAP/WSDL sense, you might want to look at Generating a WSDL using Python and SOAPpy

jQuery - find table row containing table cell containing specific text

You can use filter() to do that:

var tableRow = $("td").filter(function() {
    return $(this).text() == "foo";
}).closest("tr");

pass post data with window.location.href

Using window.location.href it's not possible to send a POST request.

What you have to do is to set up a form tag with data fields in it, set the action attribute of the form to the URL and the method attribute to POST, then call the submit method on the form tag.

Creating a "Hello World" WebSocket example

I couldnt find a simple working example anywhere (as of Jan 19), so here is an updated version. I have chrome version 71.0.3578.98.

C# Websocket server :

using System;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.Security.Cryptography;

namespace WebSocketServer
{
    class Program
    {
    static Socket serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
    static private string guid = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";

    static void Main(string[] args)
    {
        serverSocket.Bind(new IPEndPoint(IPAddress.Any, 8080));
        serverSocket.Listen(1); //just one socket
        serverSocket.BeginAccept(null, 0, OnAccept, null);
        Console.Read();
    }

    private static void OnAccept(IAsyncResult result)
    {
        byte[] buffer = new byte[1024];
        try
        {
            Socket client = null;
            string headerResponse = "";
            if (serverSocket != null && serverSocket.IsBound)
            {
                client = serverSocket.EndAccept(result);
                var i = client.Receive(buffer);
                headerResponse = (System.Text.Encoding.UTF8.GetString(buffer)).Substring(0, i);
                // write received data to the console
                Console.WriteLine(headerResponse);
                Console.WriteLine("=====================");
            }
            if (client != null)
            {
                /* Handshaking and managing ClientSocket */
                var key = headerResponse.Replace("ey:", "`")
                          .Split('`')[1]                     // dGhlIHNhbXBsZSBub25jZQ== \r\n .......
                          .Replace("\r", "").Split('\n')[0]  // dGhlIHNhbXBsZSBub25jZQ==
                          .Trim();

                // key should now equal dGhlIHNhbXBsZSBub25jZQ==
                var test1 = AcceptKey(ref key);

                var newLine = "\r\n";

                var response = "HTTP/1.1 101 Switching Protocols" + newLine
                     + "Upgrade: websocket" + newLine
                     + "Connection: Upgrade" + newLine
                     + "Sec-WebSocket-Accept: " + test1 + newLine + newLine
                     //+ "Sec-WebSocket-Protocol: chat, superchat" + newLine
                     //+ "Sec-WebSocket-Version: 13" + newLine
                     ;

                client.Send(System.Text.Encoding.UTF8.GetBytes(response));
                var i = client.Receive(buffer); // wait for client to send a message
                string browserSent = GetDecodedData(buffer, i);
                Console.WriteLine("BrowserSent: " + browserSent);

                Console.WriteLine("=====================");
                //now send message to client
                client.Send(GetFrameFromString("This is message from server to client."));
                System.Threading.Thread.Sleep(10000);//wait for message to be sent
            }
        }
        catch (SocketException exception)
        {
            throw exception;
        }
        finally
        {
            if (serverSocket != null && serverSocket.IsBound)
            {
                serverSocket.BeginAccept(null, 0, OnAccept, null);
            }
        }
    }

    public static T[] SubArray<T>(T[] data, int index, int length)
    {
        T[] result = new T[length];
        Array.Copy(data, index, result, 0, length);
        return result;
    }

    private static string AcceptKey(ref string key)
    {
        string longKey = key + guid;
        byte[] hashBytes = ComputeHash(longKey);
        return Convert.ToBase64String(hashBytes);
    }

    static SHA1 sha1 = SHA1CryptoServiceProvider.Create();
    private static byte[] ComputeHash(string str)
    {
        return sha1.ComputeHash(System.Text.Encoding.ASCII.GetBytes(str));
    }

    //Needed to decode frame
    public static string GetDecodedData(byte[] buffer, int length)
    {
        byte b = buffer[1];
        int dataLength = 0;
        int totalLength = 0;
        int keyIndex = 0;

        if (b - 128 <= 125)
        {
            dataLength = b - 128;
            keyIndex = 2;
            totalLength = dataLength + 6;
        }

        if (b - 128 == 126)
        {
            dataLength = BitConverter.ToInt16(new byte[] { buffer[3], buffer[2] }, 0);
            keyIndex = 4;
            totalLength = dataLength + 8;
        }

        if (b - 128 == 127)
        {
            dataLength = (int)BitConverter.ToInt64(new byte[] { buffer[9], buffer[8], buffer[7], buffer[6], buffer[5], buffer[4], buffer[3], buffer[2] }, 0);
            keyIndex = 10;
            totalLength = dataLength + 14;
        }

        if (totalLength > length)
            throw new Exception("The buffer length is small than the data length");

        byte[] key = new byte[] { buffer[keyIndex], buffer[keyIndex + 1], buffer[keyIndex + 2], buffer[keyIndex + 3] };

        int dataIndex = keyIndex + 4;
        int count = 0;
        for (int i = dataIndex; i < totalLength; i++)
        {
            buffer[i] = (byte)(buffer[i] ^ key[count % 4]);
            count++;
        }

        return Encoding.ASCII.GetString(buffer, dataIndex, dataLength);
    }

    //function to create  frames to send to client 
    /// <summary>
    /// Enum for opcode types
    /// </summary>
    public enum EOpcodeType
    {
        /* Denotes a continuation code */
        Fragment = 0,

        /* Denotes a text code */
        Text = 1,

        /* Denotes a binary code */
        Binary = 2,

        /* Denotes a closed connection */
        ClosedConnection = 8,

        /* Denotes a ping*/
        Ping = 9,

        /* Denotes a pong */
        Pong = 10
    }

    /// <summary>Gets an encoded websocket frame to send to a client from a string</summary>
    /// <param name="Message">The message to encode into the frame</param>
    /// <param name="Opcode">The opcode of the frame</param>
    /// <returns>Byte array in form of a websocket frame</returns>
    public static byte[] GetFrameFromString(string Message, EOpcodeType Opcode = EOpcodeType.Text)
    {
        byte[] response;
        byte[] bytesRaw = Encoding.Default.GetBytes(Message);
        byte[] frame = new byte[10];

        int indexStartRawData = -1;
        int length = bytesRaw.Length;

        frame[0] = (byte)(128 + (int)Opcode);
        if (length <= 125)
        {
            frame[1] = (byte)length;
            indexStartRawData = 2;
        }
        else if (length >= 126 && length <= 65535)
        {
            frame[1] = (byte)126;
            frame[2] = (byte)((length >> 8) & 255);
            frame[3] = (byte)(length & 255);
            indexStartRawData = 4;
        }
        else
        {
            frame[1] = (byte)127;
            frame[2] = (byte)((length >> 56) & 255);
            frame[3] = (byte)((length >> 48) & 255);
            frame[4] = (byte)((length >> 40) & 255);
            frame[5] = (byte)((length >> 32) & 255);
            frame[6] = (byte)((length >> 24) & 255);
            frame[7] = (byte)((length >> 16) & 255);
            frame[8] = (byte)((length >> 8) & 255);
            frame[9] = (byte)(length & 255);

            indexStartRawData = 10;
        }

        response = new byte[indexStartRawData + length];

        int i, reponseIdx = 0;

        //Add the frame bytes to the reponse
        for (i = 0; i < indexStartRawData; i++)
        {
            response[reponseIdx] = frame[i];
            reponseIdx++;
        }

        //Add the data bytes to the response
        for (i = 0; i < length; i++)
        {
            response[reponseIdx] = bytesRaw[i];
            reponseIdx++;
        }

        return response;
    }
}
}

Client html and javascript:

_x000D_
_x000D_
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"_x000D_
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">_x000D_
<html xmlns="http://www.w3.org/1999/xhtml">_x000D_
<head>_x000D_
    <script type="text/javascript">_x000D_
        var socket = new WebSocket('ws://localhost:8080/websession');_x000D_
        socket.onopen = function() {_x000D_
           // alert('handshake successfully established. May send data now...');_x000D_
     socket.send("Hi there from browser.");_x000D_
        };_x000D_
  socket.onmessage = function (evt) {_x000D_
                //alert("About to receive data");_x000D_
                var received_msg = evt.data;_x000D_
                alert("Message received = "+received_msg);_x000D_
            };_x000D_
        socket.onclose = function() {_x000D_
            alert('connection closed');_x000D_
        };_x000D_
    </script>_x000D_
</head>_x000D_
<body>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Maven does not find JUnit tests to run

If your test class name does not follow the standard naming convention (as highlighted by @axtavt above), you need to add the pattern/class name in the pom.xml in order to Maven pick the test -

...
<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <configuration>
                <includes>
                    <include>**/*_UT.java</include>
                </includes>
            </configuration>
        </plugin>
    </plugins>
</build> 
...

How do you install Google frameworks (Play, Accounts, etc.) on a Genymotion virtual device?

Install Genymotion 2.10 or above, now there is a dedicated button to install Google Play Services name "Open GApps". Link for more info

3 Steps process for Genymotion 2.9 or below:-

4.4 Kitkat
5.0 Lollipop
5.1 Lollipop
6.0 Marshmallow
7.0 Nougat
7.1 Nougat (webview patch)
8.0 Oreo
8.1 Oreo
9.0 Pie

  1. Download from above link
  2. Just drag & drop downloaded zip file to genymotion and restart
  3. Add google account and download "Google Play Music" and Run.


Allow a div to cover the whole page instead of the area within the container

Apply a css-reset to reset all the margins and paddings like this

/* http://meyerweb.com/eric/tools/css/reset/ 

v2.0 | 20110126 License: none (public domain) */

html, body, div, span, applet, object, iframe,
h1, h2, h3, h4, h5, h6, p, blockquote, pre,
a, abbr, acronym, address, big, cite, code,
del, dfn, em, img, ins, kbd, q, s, samp,
small, strike, strong, sub, sup, tt, var,
b, u, i, center,
dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, canvas, details, embed, 
figure, figcaption, footer, header, hgroup, 
menu, nav, output, ruby, section, summary,
time, mark, audio, video {
margin: 0;
padding: 0;
border: 0;
font-size: 100%;
font: inherit;
vertical-align: baseline;
}
/* HTML5 display-role reset for older browsers */
article, aside, details, figcaption, figure, 
footer, header, hgroup, menu, nav, section {
display: block;
}
body {
line-height: 1;
}
ol, ul {
list-style: none;
}
blockquote, q {
quotes: none;
}
blockquote:before, blockquote:after,
q:before, q:after {
content: '';
content: none;
}
table {
border-collapse: collapse;
border-spacing: 0;
}

You can use various css-resets as you need, normal and use in css

 html
 {
  margin: 0px;
 padding: 0px;
 }

body
{
margin: 0px;
padding: 0px;
}

How to get the path of src/test/resources directory in JUnit?

With Spring you could easily read it from the resources folder (either main/resources or test/resources):

For example create a file: test/resources/subfolder/sample.json

@Test
public void testReadFile() {
    String json = this.readFile("classpath:subfolder/sample.json");
    System.out.println(json);
}

public String readFile(String path) {
    try {
        File file = ResourceUtils.getFile(path);
        return new String(Files.readAllBytes(file.toPath()));
    } catch (IOException e) {
        e.printStackTrace();
    }

    return null;
}

What does the NS prefix mean?

NeXTSTEP or NeXTSTEP/Sun depending on who you are asking.

Sun had a fairly large investment in OpenStep for a while. Before Sun entered the picture most things in the foundation, even though it wasn't known as the foundation back then, was prefixed NX, for NeXT, and sometime just before Sun entered the picture everything was renamed to NS. The S most likely did not stand for Sun then but after Sun stepped in the general consensus was that it stood for Sun to honor their involvement.

I actually had a reference for this but I can't find it right now. I will update the post if/when I find it again.

How do I apply CSS3 transition to all properties except background-position?

Here's a solution that also works on Firefox:

transition: all 0.3s ease, background-position 1ms;

I made a small demo: http://jsfiddle.net/aWzwh/

Unit testing with Spring Security

Using a static in this case is the best way to write secure code.

Yes, statics are generally bad - generally, but in this case, the static is what you want. Since the security context associates a Principal with the currently running thread, the most secure code would access the static from the thread as directly as possible. Hiding the access behind a wrapper class that is injected provides an attacker with more points to attack. They wouldn't need access to the code (which they would have a hard time changing if the jar was signed), they just need a way to override the configuration, which can be done at runtime or slipping some XML onto the classpath. Even using annotation injection would be overridable with external XML. Such XML could inject the running system with a rogue principal.

Save file to specific folder with curl command

For powershell in Windows, you can add relative path + filename to --output flag:

curl -L  http://github.com/GorvGoyl/Notion-Boost-browser-extension/archive/master.zip --output build_firefox/master-repo.zip

here build_firefox is relative folder.

Executing Javascript from Python

Using PyV8, I can do this. However, I have to replace document.write with return because there's no DOM and therefore no document.

import PyV8
ctx = PyV8.JSContext()
ctx.enter()

js = """
function escramble_758(){
var a,b,c
a='+1 '
b='84-'
a+='425-'
b+='7450'
c='9'
document.write(a+c+b)
}
escramble_758()
"""

print ctx.eval(js.replace("document.write", "return "))

Or you could create a mock document object

class MockDocument(object):

    def __init__(self):
        self.value = ''

    def write(self, *args):
        self.value += ''.join(str(i) for i in args)


class Global(PyV8.JSClass):
    def __init__(self):
        self.document = MockDocument()

scope = Global()
ctx = PyV8.JSContext(scope)
ctx.enter()
ctx.eval(js)
print scope.document.value

How to add directory to classpath in an application run profile in IntelliJ IDEA?

I am using Idea 8. in your module dependancies tab (in the project structure dialog). Add a "Module Library". There you can select a Jar Directory to add. Then make sure the run profile is using the Classpath and JDK of the correct module when it runs (this is in the run config dialog.

Command-line Unix ASCII-based charting / plotting tool

While gnuplot is powerful, it's also really irritating when you just want to pipe in a bunch of points and get a graph.

Thankfully, someone created eplot (easy plot), which handles all the nonsense for you.

It doesn't seem to have an option to force terminal graphs; I patched it like so:

--- eplot.orig  2012-10-12 17:07:35.000000000 -0700
+++ eplot       2012-10-12 17:09:06.000000000 -0700
@@ -377,6 +377,7 @@
                # ---- print the options
                com="echo '\n"+getStyleString+@oc["MiscOptions"]
                com=com+"set multiplot;\n" if doMultiPlot
+               com=com+"set terminal dumb;\n"
                com=com+"plot "+@oc["Range"]+comString+"\n'| gnuplot -persist"
                printAndRun(com)
                # ---- convert to PDF

An example of use:

[$]> git shortlog -s -n | awk '{print $1}' | eplot 2> /dev/null


  3500 ++-------+-------+--------+--------+-------+--------+-------+-------++
       +        +       +        "/tmp/eplot20121012-19078-fw3txm-0" ****** +       *                                                                    |  3000 +*                                                                  ++       |*                                                                   |       | *                                                                  |  2500 ++*                                                                 ++       | *                                                                  |
       |  *                                                                 |
  2000 ++ *                                                                ++
       |  **                                                                |
  1500 ++   ****                                                           ++
       |        *                                                           |
       |         **                                                         |
  1000 ++          *                                                       ++
       |            *                                                       |
       |            *                                                       |
   500 ++            ***                                                   ++
       |                **************                                      |
       +        +       +        +    **********  +        +       +        +
     0 ++-------+-------+--------+--------+-----***************************++
       0        5       10       15       20      25       30      35       40

How do I get logs from all pods of a Kubernetes replication controller?

I've created a small bash script called kubetail that makes this possible. For example to tail all logs for pods named "app1" you can do:

kubetail app1

You can find the script here.

How to configure postgresql for the first time?

Under Linux PostgresQL is usually configured to allow the root user to login as the postgres superuser postgres from the shell (console or ssh).

$ psql -U postgres

Then you would just create a new database as usual:

CREATE ROLE myuser LOGIN password 'secret';
CREATE DATABASE mydatabase ENCODING 'UTF8' OWNER myuser;

This should work without touching pg_hba.conf. If you want to be able to do this using some GUI tool over the network - then you would need to mess with pg_hba.conf.

Javascript decoding html entities

var text = '&lt;p&gt;name&lt;/p&gt;&lt;p&gt;&lt;span style="font-size:xx-small;"&gt;ajde&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;em&gt;da&lt;/em&gt;&lt;/p&gt;';
var decoded = $('<textarea/>').html(text).text();
alert(decoded);

This sets the innerHTML of a new element (not appended to the page), causing jQuery to decode it into HTML, which is then pulled back out with .text().

Live demo.

How to block until an event is fired in c#

A very easy kind of event you can wait for is the ManualResetEvent, and even better, the ManualResetEventSlim.

They have a WaitOne() method that does exactly that. You can wait forever, or set a timeout, or a "cancellation token" which is a way for you to decide to stop waiting for the event (if you want to cancel your work, or your app is asked to exit).

You fire them calling Set().

Here is the doc.

HTML to PDF with Node.js

Phantom.js is an headless webkit server and it will load any web page and render it in memory, although you might not be able to see it, there is a Screen Capture feature, in which you can export the current view as PNG, PDF, JPEG and GIF. Have a look at this example from phantom.js documentation

"Could not find bundler" error

For anyone encountering this issue with Capistrano: capistrano isn't able to locate the bundler. The reason might be that you installed bundler under some other gemset where the Capistrano isn't even looking.

  1. List your gemsets.

rvm gemset list

  1. Use a particular gemset.

rvm use 'my_get_set'

  1. Install bundler under that gemset.

gem install bundler

Then, try again with the deploy task.

How to determine if OpenSSL and mod_ssl are installed on Apache2

Create a test.php file with the following code in a www folder:

<?php echo phpinfo();?>

When you navigate to that page/URL in the browser. You will see something similar if you have openssl enabled:

enter image description here

Use of symbols '@', '&', '=' and '>' in custom directive's scope binding: AngularJS

< one-way binding

= two-way binding

& function binding

@ pass only strings

Need a good hex editor for Linux

Bless is a high quality, full featured hex editor.

It is written in mono/Gtk# and its primary platform is GNU/Linux. However it should be able to run without problems on every platform that mono and Gtk# run.

Bless currently provides the following features:

  • Efficient editing of large data files and block devices.
  • Multilevel undo - redo operations.
  • Customizable data views.
  • Fast data rendering on screen.
  • Multiple tabs.
  • Fast find and replace operations.
  • A data conversion table.
  • Advanced copy/paste capabilities.
  • Highlighting of selection pattern matches in the file.
  • Plugin based architecture.
  • Export of data to text and html (others with plugins).
  • Bitwise operations on data.
  • A comprehensive user manual.

wxHexEditor is another Free Hex Editor, built because there is no good hex editor for Linux system, specially for big files.

  • It uses 64 bit file descriptors (supports files or devices up to 2^64 bytes , means some exabytes but tested only 1 PetaByte file (yet). ).
  • It does NOT copy whole file to your RAM. That make it FAST and can open files (which sizes are Multi Giga < Tera < Peta < Exabytes)
  • Could open your devices on Linux, Windows or MacOSX.
  • Memory Usage : Currently ~10 MegaBytes while opened multiple > ~8GB files.
  • Could operate thru XOR encryption.
  • Written with C++/wxWidgets GUI libs and can be used with other OSes such as Mac OS, Windows as native application.
  • You can copy/edit your Disks, HDD Sectors with it.( Usefull for rescue files/partitions by hand. )
  • You can delete/insert bytes to file, more than once, without creating temp file.

DHEX is a more than just another hex editor: It includes a diff mode, which can be used to easily and conveniently compare two binary files. Since it is based on ncurses and is themeable, it can run on any number of systems and scenarios. With its utilization of search logs, it is possible to track changes in different iterations of files easily. Wikipedia article

You can sort on Linux to find some more here: http://en.wikipedia.org/wiki/Comparison_of_hex_editors

How to get name of dataframe column in pyspark?

If you want the column names of your dataframe, you can use the pyspark.sql class. I'm not sure if the SDK supports explicitly indexing a DF by column name. I received this traceback:

>>> df.columns['High'] Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: list indices must be integers, not str

However, calling the columns method on your dataframe, which you have done, will return a list of column names:

df.columns will return ['Date', 'Open', 'High', 'Low', 'Close', 'Volume', 'Adj Close']

If you want the column datatypes, you can call the dtypes method:

df.dtypes will return [('Date', 'timestamp'), ('Open', 'double'), ('High', 'double'), ('Low', 'double'), ('Close', 'double'), ('Volume', 'int'), ('Adj Close', 'double')]

If you want a particular column, you'll need to access it by index:

df.columns[2] will return 'High'

convert UIImage to NSData

Use if-let block with Data to prevent app crash & safe execution of code, as function UIImagePNGRepresentation returns an optional value.

if let img = UIImage(named: "TestImage.png") {
    if let data:Data = UIImagePNGRepresentation(img) {
       // Handle operations with data here...         
    }
}

Note: Data is Swift 3 class. Use Data instead of NSData with Swift 3

Generic image operations (like png & jpg both):

if let img = UIImage(named: "TestImage.png") {  //UIImage(named: "TestImage.jpg")
        if let data:Data = UIImagePNGRepresentation(img) {
               handleOperationWithData(data: data)     
        } else if let data:Data = UIImageJPEGRepresentation(img, 1.0) {
               handleOperationWithData(data: data)     
        }
}

*******
func handleOperationWithData(data: Data) {
     // Handle operations with data here...
     if let image = UIImage(data: data) {
        // Use image...
     }
}

By using extension:

extension UIImage {

    var pngRepresentationData: Data? {
        return UIImagePNGRepresentation(img)
    }

    var jpegRepresentationData: Data? {
        return UIImageJPEGRepresentation(self, 1.0)
    }
}

*******
if let img = UIImage(named: "TestImage.png") {  //UIImage(named: "TestImage.jpg")
      if let data = img.pngRepresentationData {
              handleOperationWithData(data: data)     
      } else if let data = img.jpegRepresentationData {
              handleOperationWithData(data: data)     
     }
}

*******
func handleOperationWithData(data: Data) {
     // Handle operations with data here...
     if let image = UIImage(data: data) {
        // Use image...
     }
}

Delete all duplicate rows Excel vba

The duplicate values in any column can be deleted with a simple for loop.

Sub remove()
Dim a As Long
For a = Cells(Rows.Count, 1).End(xlUp).Row To 1 Step -1
If WorksheetFunction.CountIf(Range("A1:A" & a), Cells(a, 1)) > 1 Then Rows(a).Delete
Next
End Sub

Disable button in WPF?

By code:

btn_edit.IsEnabled = true;

By XAML:

<Button Content="Edit data" Grid.Column="1" Name="btn_edit" Grid.Row="1" IsEnabled="False" />

Spring Boot Configure and Use Two DataSources

Here is the Complete solution

#First Datasource (DB1)
db1.datasource.url: url
db1.datasource.username:user
db1.datasource.password:password

#Second Datasource (DB2)
db2.datasource.url:url
db2.datasource.username:user
db2.datasource.password:password

Since we are going to get access two different databases (db1, db2), we need to configure each data source configuration separately like:

public class DB1_DataSource {
@Autowired
private Environment env;
@Bean
@Primary
public LocalContainerEntityManagerFactoryBean db1EntityManager() {
    LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
    em.setDataSource(db1Datasource());
    em.setPersistenceUnitName("db1EntityManager");
    HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
    em.setJpaVendorAdapter(vendorAdapter);
    HashMap<string, object=""> properties = new HashMap<>();
    properties.put("hibernate.dialect",
            env.getProperty("hibernate.dialect"));
    properties.put("hibernate.show-sql",
            env.getProperty("jdbc.show-sql"));
    em.setJpaPropertyMap(properties);
    return em;
}

@Primary
@Bean
public DataSource db1Datasource() {

    DriverManagerDataSource dataSource
            = new DriverManagerDataSource();
    dataSource.setDriverClassName(
            env.getProperty("jdbc.driver-class-name"));
    dataSource.setUrl(env.getProperty("db1.datasource.url"));
    dataSource.setUsername(env.getProperty("db1.datasource.username"));
    dataSource.setPassword(env.getProperty("db1.datasource.password"));

    return dataSource;
}

@Primary
@Bean
public PlatformTransactionManager db1TransactionManager() {

    JpaTransactionManager transactionManager
            = new JpaTransactionManager();
    transactionManager.setEntityManagerFactory(
            db1EntityManager().getObject());
    return transactionManager;
}
}

Second Datasource :

public class DB2_DataSource {

@Autowired
private Environment env;

@Bean
public LocalContainerEntityManagerFactoryBean db2EntityManager() {
    LocalContainerEntityManagerFactoryBean em
            = new LocalContainerEntityManagerFactoryBean();
    em.setDataSource(db2Datasource());
    em.setPersistenceUnitName("db2EntityManager");
    HibernateJpaVendorAdapter vendorAdapter
            = new HibernateJpaVendorAdapter();
    em.setJpaVendorAdapter(vendorAdapter);
    HashMap<string, object=""> properties = new HashMap<>();
    properties.put("hibernate.dialect",
            env.getProperty("hibernate.dialect"));
    properties.put("hibernate.show-sql",
            env.getProperty("jdbc.show-sql"));
    em.setJpaPropertyMap(properties);
    return em;
}

@Bean
public DataSource db2Datasource() {
    DriverManagerDataSource dataSource
            = new DriverManagerDataSource();
    dataSource.setDriverClassName(
            env.getProperty("jdbc.driver-class-name"));
    dataSource.setUrl(env.getProperty("db2.datasource.url"));
    dataSource.setUsername(env.getProperty("db2.datasource.username"));
    dataSource.setPassword(env.getProperty("db2.datasource.password"));

    return dataSource;
}

@Bean
public PlatformTransactionManager db2TransactionManager() {
    JpaTransactionManager transactionManager
            = new JpaTransactionManager();
    transactionManager.setEntityManagerFactory(
            db2EntityManager().getObject());
    return transactionManager;
}
}

Here you can find the complete Example on my blog : Spring Boot with Multiple DataSource Configuration

How to convert image file data in a byte array to a Bitmap?

Just try this:

Bitmap bitmap = BitmapFactory.decodeFile("/path/images/image.jpg");
ByteArrayOutputStream blob = new ByteArrayOutputStream();
bitmap.compress(CompressFormat.PNG, 0 /* Ignored for PNGs */, blob);
byte[] bitmapdata = blob.toByteArray();

If bitmapdata is the byte array then getting Bitmap is done like this:

Bitmap bitmap = BitmapFactory.decodeByteArray(bitmapdata, 0, bitmapdata.length);

Returns the decoded Bitmap, or null if the image could not be decoded.

Setting Curl's Timeout in PHP

Your code sets the timeout to 1000 seconds. For milliseconds, use CURLOPT_TIMEOUT_MS.

Getting a list of all subdirectories in the current directory

Since I stumbled upon this problem using Python 3.4 and Windows UNC paths, here's a variant for this environment:

from pathlib import WindowsPath

def SubDirPath (d):
    return [f for f in d.iterdir() if f.is_dir()]

subdirs = SubDirPath(WindowsPath(r'\\file01.acme.local\home$'))
print(subdirs)

Pathlib is new in Python 3.4 and makes working with paths under different OSes much easier: https://docs.python.org/3.4/library/pathlib.html

How to duplicate sys.stdout to a log file?

What you really want is logging module from standard library. Create a logger and attach two handlers, one would be writing to a file and the other to stdout or stderr.

See Logging to multiple destinations for details

Lua - Current time in milliseconds

If you're using lua with nginx/openresty you could use ngx.now() which returns a float with millisecond precision

CSS class for pointer cursor

Bootstrap 3 - Just adding the "btn" Class worked for me.

Without pointer cursor:

<span class="label label-success">text</span>

With pointer cursor:

<span class="label label-success btn">text</span>

Convert txt to csv python script

import pandas as pd
df = pd.read_fwf('log.txt')
df.to_csv('log.csv')

How to display databases in Oracle 11g using SQL*Plus

I am not clearly about it but typically one server has one database (with many users), if you create many databases mean that you create many instances, listeners, ... as well. So you can check your LISTENER to identify it.

In my testing I created 2 databases (dbtest and dbtest_1) so when I check my LISTENER status it appeared like this:

lsnrctl status

....

STATUS of the LISTENER

.....

(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=10.10.20.20)(PORT=1521)))

Services Summary...

Service "dbtest" has 1 instance(s).

Instance "dbtest", status READY, has 1 handler(s) for this service...

Service "dbtest1XDB" has 1 instance(s).

Instance "dbtest1", status READY, has 1 handler(s) for this service...

Service "dbtest_1" has 1 instance(s).

Instance "dbtest1", status READY, has 1 handler(s) for this service... The command completed successfully

ant warning: "'includeantruntime' was not set"

Ant Runtime

Simply set includeantruntime="false":

<javac includeantruntime="false" ...>...</javac>

If you have to use the javac-task multiple times you might want to consider using PreSetDef to define your own javac-task that always sets includeantruntime="false".

Additional Details

From http://www.coderanch.com/t/503097/tools/warning-includeantruntime-was-not-set:

That's caused by a misfeature introduced in Ant 1.8. Just add an attribute of that name to the javac task, set it to false, and forget it ever happened.

From http://ant.apache.org/manual/Tasks/javac.html:

Whether to include the Ant run-time libraries in the classpath; defaults to yes, unless build.sysclasspath is set. It is usually best to set this to false so the script's behavior is not sensitive to the environment in which it is run.

How to convert CSV to JSON in Node.js

I have used csvtojson library for converting csv string to json array. It has variety of function which can help you to convert to JSON.
It also supports reading from file and file streaming.

Be careful while parsing the csv which can contain the comma(,) or any other delimiter . For removing the delimiter please see my answer here.

Use of def, val, and var in scala

I'd start by the distinction that exists in Scala between def, val and var.

  • def - defines an immutable label for the right side content which is lazily evaluated - evaluate by name.

  • val - defines an immutable label for the right side content which is eagerly/immediately evaluated - evaluated by value.

  • var - defines a mutable variable, initially set to the evaluated right side content.

Example, def

scala> def something = 2 + 3 * 4 
something: Int
scala> something  // now it's evaluated, lazily upon usage
res30: Int = 14

Example, val

scala> val somethingelse = 2 + 3 * 5 // it's evaluated, eagerly upon definition
somethingelse: Int = 17

Example, var

scala> var aVariable = 2 * 3
aVariable: Int = 6

scala> aVariable = 5
aVariable: Int = 5

According to above, labels from def and val cannot be reassigned, and in case of any attempt an error like the below one will be raised:

scala> something = 5 * 6
<console>:8: error: value something_= is not a member of object $iw
       something = 5 * 6
       ^

When the class is defined like:

scala> class Person(val name: String, var age: Int)
defined class Person

and then instantiated with:

scala> def personA = new Person("Tim", 25)
personA: Person

an immutable label is created for that specific instance of Person (i.e. 'personA'). Whenever the mutable field 'age' needs to be modified, such attempt fails:

scala> personA.age = 44
personA.age: Int = 25

as expected, 'age' is part of a non-mutable label. The correct way to work on this consists in using a mutable variable, like in the following example:

scala> var personB = new Person("Matt", 36)
personB: Person = Person@59cd11fe

scala> personB.age = 44
personB.age: Int = 44    // value re-assigned, as expected

as clear, from the mutable variable reference (i.e. 'personB') it is possible to modify the class mutable field 'age'.

I would still stress the fact that everything comes from the above stated difference, that has to be clear in mind of any Scala programmer.

Convert char to int in C and C++

Use static_cast<int>:

int num = static_cast<int>(letter); // if letter='a', num=97

Edit: You probably should try to avoid to use (int)

int num = (int) letter;

check out Why use static_cast<int>(x) instead of (int)x? for more info.

Android Studio: Unable to start the daemon process

I faced this issue in intellij idea and solved by doing this,

try to set "VM options" to -Xmx512m at Settings | Build, Execution, Deployment | Build Tools | Gradle | Gradle VM options

Make Bootstrap's Carousel both center AND responsive?

Add a class to each image in the carousel html code, then with css apply margin: 0 auto.

How to convert an Object {} to an Array [] of key-value pairs in JavaScript

If you are using lodash, it could be as simple as this:

var arr = _.values(obj);

How can I convert a long to int in Java?

Shortest, most safe and easiest solution is:

long myValue=...;
int asInt = Long.valueOf(myValue).intValue();

Do note, the behavior of Long.valueOf is as such:

Using this code:

System.out.println("Long max: " + Long.MAX_VALUE);
System.out.println("Int max: " + Integer.MAX_VALUE);        
long maxIntValue = Integer.MAX_VALUE;
System.out.println("Long maxIntValue to int: " + Long.valueOf(maxIntValue).intValue());
long maxIntValuePlusOne = Integer.MAX_VALUE + 1;
System.out.println("Long maxIntValuePlusOne to int: " + Long.valueOf(maxIntValuePlusOne).intValue());
System.out.println("Long max to int: " + Long.valueOf(Long.MAX_VALUE).intValue());

Results into:

Long max: 9223372036854775807
Int max: 2147483647
Long max to int: -1
Long maxIntValue to int: 2147483647
Long maxIntValuePlusOne to int: -2147483648

How to write a full path in a batch file having a folder name with space?

start "" AcroRd32.exe /A "page=207" "C:\Users\abc\Desktop\abc xyz def\abc def xyz 2015.pdf"

You may try this, I did it finally, it works!

Field 'id' doesn't have a default value?

There are 2 solutions mentioned below:

Solution 1

MySQL is most likely in STRICT SQL mode. Try to execute SQL query SET GLOBAL sql_mode='' or edit your my.cnf / my.ini to make sure you aren't setting STRICT_ALL_TABLES and/or STRICT_TRANS_TABLES.

Solution 2

If Solution-1 is not working then try Solution-2 as given in below steps:

  1. Run MySQL Administrator tool as Administrator.
  2. Then go to Startup Variable.
  3. Then go to the Advance tab.
  4. find SQL Mode and remove the STRICT_ALL_TABLES and/or STRICT_TRANS_TABLES and then Click on Apply Changes.
  5. Restart MySQL Server.
  6. Done.

Note: I have tested these solutions in MySQL Server 5.7

ImportError: No module named 'Queue'

I run into the same problem and learn that queue module defines classes and exceptions, that defines the public methods (Queue Objects).

Ex.

workQueue = queue.Queue(10)

Can a Byte[] Array be written to a file in C#?

Yep, why not?

fs.Write(myByteArray, 0, myByteArray.Length);

Create a simple HTTP server with Java?

A servlet container is definitely the way to go. If Tomcat or Jetty are too heavyweight for you, consider Winstone or TTiny.

Difference between "on-heap" and "off-heap"

from http://code.google.com/p/fast-serialization/wiki/QuickStartHeapOff

What is Heap-Offloading ?

Usually all non-temporary objects you allocate are managed by java's garbage collector. Although the VM does a decent job doing garbage collection, at a certain point the VM has to do a so called 'Full GC'. A full GC involves scanning the complete allocated Heap, which means GC pauses/slowdowns are proportional to an applications heap size. So don't trust any person telling you 'Memory is Cheap'. In java memory consumtion hurts performance. Additionally you may get notable pauses using heap sizes > 1 Gb. This can be nasty if you have any near-real-time stuff going on, in a cluster or grid a java process might get unresponsive and get dropped from the cluster.

However todays server applications (frequently built on top of bloaty frameworks ;-) ) easily require heaps far beyond 4Gb.

One solution to these memory requirements, is to 'offload' parts of the objects to the non-java heap (directly allocated from the OS). Fortunately java.nio provides classes to directly allocate/read and write 'unmanaged' chunks of memory (even memory mapped files).

So one can allocate large amounts of 'unmanaged' memory and use this to save objects there. In order to save arbitrary objects into unmanaged memory, the most viable solution is the use of Serialization. This means the application serializes objects into the offheap memory, later on the object can be read using deserialization.

The heap size managed by the java VM can be kept small, so GC pauses are in the millis, everybody is happy, job done.

It is clear, that the performance of such an off heap buffer depends mostly on the performance of the serialization implementation. Good news: for some reason FST-serialization is pretty fast :-).

Sample usage scenarios:

  • Session cache in a server application. Use a memory mapped file to store gigabytes of (inactive) user sessions. Once the user logs into your application, you can quickly access user-related data without having to deal with a database.
  • Caching of computational results (queries, html pages, ..) (only applicable if computation is slower than deserializing the result object ofc).
  • very simple and fast persistance using memory mapped files

Edit: For some scenarios one might choose more sophisticated Garbage Collection algorithms such as ConcurrentMarkAndSweep or G1 to support larger heaps (but this also has its limits beyond 16GB heaps). There is also a commercial JVM with improved 'pauseless' GC (Azul) available.

Read SQL Table into C# DataTable

Here, give this a shot (this is just a pseudocode)

using System;
using System.Data;
using System.Data.SqlClient;


public class PullDataTest
{
    // your data table
    private DataTable dataTable = new DataTable();

    public PullDataTest()
    {
    }

    // your method to pull data from database to datatable   
    public void PullData()
    {
        string connString = @"your connection string here";
        string query = "select * from table";

        SqlConnection conn = new SqlConnection(connString);        
        SqlCommand cmd = new SqlCommand(query, conn);
        conn.Open();

        // create data adapter
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        // this will query your database and return the result to your datatable
        da.Fill(dataTable);
        conn.Close();
        da.Dispose();
    }
}

How to remove the first character of string in PHP?

use mb_substr function

    mb_substr("?abc", 1);

Task not serializable: java.io.NotSerializableException when calling function outside closure only on classes not objects

I'm not entirely certain that this applies to Scala but, in Java, I solved the NotSerializableException by refactoring my code so that the closure did not access a non-serializable final field.

Using Python Requests: Sessions, Cookies, and POST

I don't know how stubhub's api works, but generally it should look like this:

s = requests.Session()
data = {"login":"my_login", "password":"my_password"}
url = "http://example.net/login"
r = s.post(url, data=data)

Now your session contains cookies provided by login form. To access cookies of this session simply use

s.cookies

Any further actions like another requests will have this cookie

How do you determine the size of a file in C?

I used this set of code to find the file length.

//opens a file with a file descriptor
FILE * i_file;
i_file = fopen(source, "r");

//gets a long from the file descriptor for fstat
long f_d = fileno(i_file);
struct stat buffer;
fstat(f_d, &buffer);

//stores file size
long file_length = buffer.st_size;
fclose(i_file);

Failed to resolve: com.android.support:appcompat-v7:26.0.0

change

compile 'com.android.support:appcompat-v7:26.0'

to

`compile 'com.android.support:appcompat-v7:26.+'`

worked for me fine.

What does InitializeComponent() do, and how does it work in WPF?

Looking at the code always helps too. That is, you can actually take a look at the generated partial class (that calls LoadComponent) by doing the following:

  1. Go to the Solution Explorer pane in the Visual Studio solution that you are interested in.
  2. There is a button in the tool bar of the Solution Explorer titled 'Show All Files'. Toggle that button.
  3. Now, expand the obj folder and then the Debug or Release folder (or whatever configuration you are building) and you will see a file titled YourClass.g.cs.

The YourClass.g.cs ... is the code for generated partial class. Again, if you open that up you can see the InitializeComponent method and how it calls LoadComponent ... and much more.

Difference between try-catch and throw in java

Try/catch and throw clause are for different purposes. So they are not alternative to each other but they are complementary.

  1. If you have throw some checked exception in your code, it should be inside some try/catch in codes calling hierarchy.

  2. Conversely, you need try/catch block only if there is some throw clause inside the code (your code or the API call) that throws checked exception.

Sometimes, you may want to throw exception if particular condition occurred which you want to handle in calling code block and in some cases handle some exception catch block and throw a same or different exception again to handle in calling block.

ImportError: No module named win32com.client

Try to install the "pywin32" file, you can find in https://github.com/mhammond/pywin32/releases

Install the version that you use in your IDLE, and try to install, after you can open your project and compile another turn!

thanks !

How to create nested directories using Mkdir in Golang?

This is one alternative for achieving the same but it avoids race condition caused by having two distinct "check ..and.. create" operations.

package main

import (
    "fmt"
    "os"
)

func main()  {
    if err := ensureDir("/test-dir"); err != nil {
        fmt.Println("Directory creation failed with error: " + err.Error())
        os.Exit(1)
    }
    // Proceed forward
}

func ensureDir(dirName string) error {

    err := os.MkdirAll(dirName, os.ModeDir)

    if err == nil || os.IsExist(err) {
        return nil
    } else {
        return err
    }
}

Gradients on UIView and UILabels On iPhone

You can use Core Graphics to draw the gradient, as pointed to in Mike's response. As a more detailed example, you could create a UIView subclass to use as a background for your UILabel. In that UIView subclass, override the drawRect: method and insert code similar to the following:

- (void)drawRect:(CGRect)rect 
{
    CGContextRef currentContext = UIGraphicsGetCurrentContext();

    CGGradientRef glossGradient;
    CGColorSpaceRef rgbColorspace;
    size_t num_locations = 2;
    CGFloat locations[2] = { 0.0, 1.0 };
    CGFloat components[8] = { 1.0, 1.0, 1.0, 0.35,  // Start color
         1.0, 1.0, 1.0, 0.06 }; // End color

    rgbColorspace = CGColorSpaceCreateDeviceRGB();
    glossGradient = CGGradientCreateWithColorComponents(rgbColorspace, components, locations, num_locations);

    CGRect currentBounds = self.bounds;
    CGPoint topCenter = CGPointMake(CGRectGetMidX(currentBounds), 0.0f);
    CGPoint midCenter = CGPointMake(CGRectGetMidX(currentBounds), CGRectGetMidY(currentBounds));
    CGContextDrawLinearGradient(currentContext, glossGradient, topCenter, midCenter, 0);

    CGGradientRelease(glossGradient);
    CGColorSpaceRelease(rgbColorspace); 
}

This particular example creates a white, glossy-style gradient that is drawn from the top of the UIView to its vertical center. You can set the UIView's backgroundColor to whatever you like and this gloss will be drawn on top of that color. You can also draw a radial gradient using the CGContextDrawRadialGradient function.

You just need to size this UIView appropriately and add your UILabel as a subview of it to get the effect you desire.

EDIT (4/23/2009): Per St3fan's suggestion, I have replaced the view's frame with its bounds in the code. This corrects for the case when the view's origin is not (0,0).

Visual Studio setup problem - 'A problem has been encountered while loading the setup components. Canceling setup.'

I had the same error message. For me it was happening because I was trying to run the installer from the DVD rather than running the installer from Add/Remove programs.

jQuery AJAX form data serialize using PHP

I just had the same problem: You have to unserialize the data on the php side.

Add to the beginning of your php file (Attention this short version would replace all other post variables):

parse_str($_POST["data"], $_POST);

HTML table sort

Another approach to sort HTML table. (based on W3.JS HTML Sort)

_x000D_
_x000D_
let tid = "#usersTable";_x000D_
let headers = document.querySelectorAll(tid + " th");_x000D_
_x000D_
// Sort the table element when clicking on the table headers_x000D_
headers.forEach(function(element, i) {_x000D_
  element.addEventListener("click", function() {_x000D_
    w3.sortHTML(tid, ".item", "td:nth-child(" + (i + 1) + ")");_x000D_
  });_x000D_
});
_x000D_
th {_x000D_
  cursor: pointer;_x000D_
  background-color: coral;_x000D_
}
_x000D_
<script src="https://www.w3schools.com/lib/w3.js"></script>_x000D_
<link href="https://www.w3schools.com/w3css/4/w3.css" rel="stylesheet" />_x000D_
<p>Click the <strong>table headers</strong> to sort the table accordingly:</p>_x000D_
_x000D_
<table id="usersTable" class="w3-table-all">_x000D_
  <!--     _x000D_
  <tr>_x000D_
    <th onclick="w3.sortHTML('#usersTable', '.item', 'td:nth-child(1)')">Name</th>_x000D_
    <th onclick="w3.sortHTML('#usersTable', '.item', 'td:nth-child(2)')">Address</th>_x000D_
    <th onclick="w3.sortHTML('#usersTable', '.item', 'td:nth-child(3)')">Sales Person</th>_x000D_
  </tr> _x000D_
  -->_x000D_
  <tr>_x000D_
    <th>Name</th>_x000D_
    <th>Address</th>_x000D_
    <th>Sales Person</th>_x000D_
  </tr>_x000D_
_x000D_
  <tr class="item">_x000D_
    <td>user:2911002</td>_x000D_
    <td>UK</td>_x000D_
    <td>Melissa</td>_x000D_
  </tr>_x000D_
  <tr class="item">_x000D_
    <td>user:2201002</td>_x000D_
    <td>France</td>_x000D_
    <td>Justin</td>_x000D_
  </tr>_x000D_
  <tr class="item">_x000D_
    <td>user:2901092</td>_x000D_
    <td>San Francisco</td>_x000D_
    <td>Judy</td>_x000D_
  </tr>_x000D_
  <tr class="item">_x000D_
    <td>user:2801002</td>_x000D_
    <td>Canada</td>_x000D_
    <td>Skipper</td>_x000D_
  </tr>_x000D_
  <tr class="item">_x000D_
    <td>user:2901009</td>_x000D_
    <td>Christchurch</td>_x000D_
    <td>Alex</td>_x000D_
  </tr>_x000D_
_x000D_
</table>
_x000D_
_x000D_
_x000D_

curl.h no such file or directory

Instead of downloading curl, down libcurl.

curl is just the application, libcurl is what you need for your C++ program

http://packages.ubuntu.com/quantal/curl

How to return Json object from MVC controller to view

You could use AJAX to call this controller action. For example if you are using jQuery you might use the $.ajax() method:

<script type="text/javascript">
    $.ajax({
        url: '@Url.Action("NameOfYourAction")',
        type: 'GET',
        cache: false,
        success: function(result) {
            // you could use the result.values dictionary here
        }
    });
</script>

Android: making a fullscreen application

If you Checkout the current Android Studio. You could create a New Activity with the Full-screen template. If you Create such an Activity. You could look into the basic code that Android Studio uses to switch between full-screen and normal mode.

Gallery Showing the Full-Screen Activity

This is the code I found in there. With some minor tweaks I'm sure you'll get what you need.

public class FullscreenActivity extends AppCompatActivity {
    private static final boolean AUTO_HIDE = true;
    private static final int AUTO_HIDE_DELAY_MILLIS = 3000;
    private static final int UI_ANIMATION_DELAY = 300;
    private final Handler mHideHandler = new Handler();
    private View mContentView;
    private final Runnable mHidePart2Runnable = new Runnable() {
        @SuppressLint("InlinedApi")
        @Override
        public void run() {
            // Delayed removal of status and navigation bar

            // Note that some of these constants are new as of API 16 (Jelly Bean)
            // and API 19 (KitKat). It is safe to use them, as they are inlined
            // at compile-time and do nothing on earlier devices.
            mContentView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE
                    | View.SYSTEM_UI_FLAG_FULLSCREEN
                    | View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                    | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
                    | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                    | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
        }
    };
    private View mControlsView;
    private final Runnable mShowPart2Runnable = new Runnable() {
        @Override
        public void run() {
            // Delayed display of UI elements
            ActionBar actionBar = getSupportActionBar();
            if (actionBar != null) {
                actionBar.show();
            }
            mControlsView.setVisibility(View.VISIBLE);
        }
    };
    private boolean mVisible;
    private final Runnable mHideRunnable = new Runnable() {
        @Override
        public void run() {
            hide();
        }
    };
    private final View.OnTouchListener mDelayHideTouchListener = new View.OnTouchListener() {
        @Override
        public boolean onTouch(View view, MotionEvent motionEvent) {
            if (AUTO_HIDE) {
                delayedHide(AUTO_HIDE_DELAY_MILLIS);
            }
            return false;
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_fullscreen);

        mVisible = true;
        mControlsView = findViewById(R.id.fullscreen_content_controls);
        mContentView = findViewById(R.id.fullscreen_content);


        // Set up the user interaction to manually show or hide the system UI.
        mContentView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                toggle();
            }
        });

        // Upon interacting with UI controls, delay any scheduled hide()
        // operations to prevent the jarring behavior of controls going away
        // while interacting with the UI.
        findViewById(R.id.dummy_button).setOnTouchListener(mDelayHideTouchListener);
    }
    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);

        // Trigger the initial hide() shortly after the activity has been
        // created, to briefly hint to the user that UI controls
        // are available.
        delayedHide(100);
    }
    private void toggle() {
        if (mVisible) {
            hide();
        } else {
            show();
        }
    }
    private void hide() {
        // Hide UI first
        ActionBar actionBar = getSupportActionBar();
        if (actionBar != null) {
            actionBar.hide();
        }
        mControlsView.setVisibility(View.GONE);
        mVisible = false;

        // Schedule a runnable to remove the status and navigation bar after a delay
        mHideHandler.removeCallbacks(mShowPart2Runnable);
        mHideHandler.postDelayed(mHidePart2Runnable, UI_ANIMATION_DELAY);
    }
    @SuppressLint("InlinedApi")
    private void show() {
        // Show the system bar
        mContentView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION);
        mVisible = true;

        // Schedule a runnable to display UI elements after a delay
        mHideHandler.removeCallbacks(mHidePart2Runnable);
        mHideHandler.postDelayed(mShowPart2Runnable, UI_ANIMATION_DELAY);
    }
    private void delayedHide(int delayMillis) {
        mHideHandler.removeCallbacks(mHideRunnable);
        mHideHandler.postDelayed(mHideRunnable, delayMillis);
    }
}

Now I went further to checkout how this could be done in a more simple fashion. Making changes to the AppTheme style in your styles.xml file would be most helpful. This changes all your activities to a Full Screen view.

<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
<item name="android:windowFullscreen">true</item>

If you want only some activities to look Full Screen, you could create a new AppTheme that extends your current app theme and include the above code in that new style that you created. This way, you just have to set style=yournewapptheme in the manifest of whichever activity you want to go Full Screen

How to retrieve current workspace using Jenkins Pipeline Groovy script?

In Jenkins pipeline script, I am using

targetDir = workspace

Works perfect for me. No need to use ${WORKSPACE}

Generating a drop down list of timezones with PHP

See this example also

<?php
     function get_timezones() 
     {
        $o = array();
        $t_zones = timezone_identifiers_list();
        foreach($t_zones as $a)
        {
            $t = '';

            try
            {
                //this throws exception for 'US/Pacific-New'
                $zone = new DateTimeZone($a);

                $seconds = $zone->getOffset( new DateTime("now" , $zone) );
                $hours = sprintf( "%+02d" , intval($seconds/3600));
                $minutes = sprintf( "%02d" , ($seconds%3600)/60 );

                $t = $a ."  [ $hours:$minutes ]" ;

                $o[$a] = $t;
            }

            //exceptions must be catched, else a blank page
            catch(Exception $e)
            {
                //die("Exception : " . $e->getMessage() . '<br />');
                //what to do in catch ? , nothing just relax
            }
        }

        ksort($o);

        return $o;
    } 

    $o = get_timezones();
    ?>

    <html>
    <body>
    <select name="time_zone">
    <?php
        foreach($o as $tz => $label)
        {
            echo "<option value="$tz">$label</option>";
        }
    ?>
    </select>
    </body>
    </html>

How to delete all files older than 3 days when "Argument list too long"?

Can also use:

find . -mindepth 1 -mtime +3 -delete

To not delete target directory

What is the default stack size, can it grow, how does it work with garbage collection?

How much a stack can grow?

You can use a VM option named ss to adjust the maximum stack size. A VM option is usually passed using -X{option}. So you can use java -Xss1M to set the maximum of stack size to 1M.

Each thread has at least one stack. Some Java Virtual Machines(JVM) put Java stack(Java method calls) and native stack(Native method calls in VM) into one stack, and perform stack unwinding using a Managed to Native Frame, known as M2NFrame. Some JVMs keep two stacks separately. The Xss set the size of the Java Stack in most cases.

For many JVMs, they put different default values for stack size on different platforms.

Can we limit this growth?

When a method call occurs, a new stack frame will be created on the stack of that thread. The stack will contain local variables, parameters, return address, etc. In java, you can never put an object on stack, only object reference can be stored on stack. Since array is also an object in java, arrays are also not stored on stack. So, if you reduce the amount of your local primitive variables, parameters by grouping them into objects, you can reduce the space on stack. Actually, the fact that we cannot explicitly put objects on java stack affects the performance some time(cache miss).

Does stack has some default minimum value or default maximum value?

As I said before, different VMs are different, and may change over versions. See here.

how does garbage collection work on stack?

Garbage collections in Java is a hot topic. Garbage collection aims to collect unreachable objects in the heap. So that needs a definition of 'reachable.' Everything on the stack constitutes part of the root set references in GC. Everything that is reachable from every stack of every thread should be considered as live. There are some other root set references, like Thread objects and some class objects.

This is only a very vague use of stack on GC. Currently most JVMs are using a generational GC. This article gives brief introduction about Java GC. And recently I read a very good article talking about the GC on .net. The GC on oracle jvm is quite similar so I think that might also help you.

How can I get the line number which threw exception?

I added an extension to Exception which returns the line, column, method, filename and message:

public static class Extensions
{
    public static string ExceptionInfo(this Exception exception)
    {

        StackFrame stackFrame = (new StackTrace(exception, true)).GetFrame(0);
        return string.Format("At line {0} column {1} in {2}: {3} {4}{3}{5}  ",
           stackFrame.GetFileLineNumber(), stackFrame.GetFileColumnNumber(),
           stackFrame.GetMethod(), Environment.NewLine, stackFrame.GetFileName(),
           exception.Message);

    }
}

How to download Google Play Services in an Android emulator?

I came across another solution to use the Google play services on an emulator. The guys at http://www.genymotion.com/ provide very fast emulators on which you can install Google play services. They just need you to sign up to begin downloading and you need Virtual box installed. At the moment they cater for Android 16 and 17 but more are on the way.

Removing multiple keys from a dictionary safely

Why not:

entriestoremove = (2,5,1)
for e in entriestoremove:
    if d.has_key(e):
        del d[e]

I don't know what you mean by "smarter way". Surely there are other ways, maybe with dictionary comprehensions:

entriestoremove = (2,5,1)
newdict = {x for x in d if x not in entriestoremove}

How do I run a batch script from within a batch script?

If you wish to open the batch file in another window, use start. This way, you can basically run two scripts at the same time. In other words, you don't have to wait for the script you just called to finish. All examples below work:

start batch.bat
start call batch.bat
start cmd /c batch.bat

If you want to wait for the script to finish, try start /w call batch.bat, but the batch.bat has to end with exit.

ASP.NET jQuery Ajax Calling Code-Behind Method

Firstly, you probably want to add a return false; to the bottom of your Submit() method in JavaScript (so it stops the submit, since you're handling it in AJAX).

You're connecting to the complete event, not the success event - there's a significant difference and that's why your debugging results aren't as expected. Also, I've never made the signature methods match yours, and I've always provided a contentType and dataType. For example:

$.ajax({
        type: "POST",
        url: "Default.aspx/OnSubmit",
        data: dataValue,                
        contentType: 'application/json; charset=utf-8',
        dataType: 'json',
        error: function (XMLHttpRequest, textStatus, errorThrown) {
            alert("Request: " + XMLHttpRequest.toString() + "\n\nStatus: " + textStatus + "\n\nError: " + errorThrown);
        },
        success: function (result) {
            alert("We returned: " + result);
        }
    });

How to check if a given directory exists in Ruby

All the other answers are correct, however, you might have problems if you're trying to check directory in a user's home directory. Make sure you expand the relative path before checking:

File.exists? '~/exists'
=> false
File.directory? '~/exists'
=> false
File.exists? File.expand_path('~/exists')
=> true

Select all DIV text with single mouse click

How about this simple solution? :)

<input style="background-color:white; border:1px white solid;" onclick="this.select();" id="selectable" value="http://example.com/page.htm">

Sure it is not div-construction, like you mentioned, but still it is worked for me.

Click a button with XPath containing partial id and title in Selenium IDE

Now that you have provided your HTML sample, we're able to see that your XPath is slightly wrong. While it's valid XPath, it's logically wrong.

You've got:

//*[contains(@id, 'ctl00_btnAircraftMapCell')]//*[contains(@title, 'Select Seat')]

Which translates into:

Get me all the elements that have an ID that contains ctl00_btnAircraftMapCell. Out of these elements, get any child elements that have a title that contains Select Seat.

What you actually want is:

//a[contains(@id, 'ctl00_btnAircraftMapCell') and contains(@title, 'Select Seat')]

Which translates into:

Get me all the anchor elements that have both: an id that contains ctl00_btnAircraftMapCell and a title that contains Select Seat.

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

new StringBuilder().append(str.charAt(0))
                   .append(str.charAt(10))
                   .append(str.charAt(20))
                   .append(str.charAt(30))
                   .toString();

This way you can get the new string with whatever characters you want.

How to add label in chart.js for pie chart

For those using newer versions Chart.js, you can set a label by setting the callback for tooltips.callbacks.label in options.

Example of this would be:

var chartOptions = {
    tooltips: {
        callbacks: {
            label: function (tooltipItem, data) {
                return 'label';
            }
        }
    }
}

Update multiple columns in SQL

update T1
set T1.COST2=T1.TOT_COST+2.000,
T1.COST3=T1.TOT_COST+2.000,
T1.COST4=T1.TOT_COST+2.000,
T1.COST5=T1.TOT_COST+2.000,
T1.COST6=T1.TOT_COST+2.000,
T1.COST7=T1.TOT_COST+2.000,
T1.COST8=T1.TOT_COST+2.000,
T1.COST9=T1.TOT_COST+2.000,
T1.COST10=T1.TOT_COST+2.000,
T1.COST11=T1.TOT_COST+2.000,
T1.COST12=T1.TOT_COST+2.000,
T1.COST13=T1.TOT_COST+2.000
from DBRMAST T1 
inner join DBRMAST t2 on t2.CODE=T1.CODE